"Robert P. J. Day" | 63fc1a9 | 2006-07-02 19:47:05 +0000 | [diff] [blame] | 1 | /* vi: set sw=4 ts=4: */ |
Denys Vlasenko | 6b24d53 | 2010-03-22 13:42:13 +0100 | [diff] [blame] | 2 | /* |
Denys Vlasenko | 385b456 | 2010-03-26 10:09:34 +0100 | [diff] [blame] | 3 | * udhcp client |
Mike Frysinger | 7031f62 | 2006-05-08 03:20:50 +0000 | [diff] [blame] | 4 | * |
| 5 | * Russ Dill <Russ.Dill@asu.edu> July 2001 |
| 6 | * |
Denys Vlasenko | 6b24d53 | 2010-03-22 13:42:13 +0100 | [diff] [blame] | 7 | * This program is free software; you can redistribute it and/or modify |
| 8 | * it under the terms of the GNU General Public License as published by |
| 9 | * the Free Software Foundation; either version 2 of the License, or |
| 10 | * (at your option) any later version. |
| 11 | * |
| 12 | * This program is distributed in the hope that it will be useful, |
| 13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | * GNU General Public License for more details. |
| 16 | * |
| 17 | * You should have received a copy of the GNU General Public License |
| 18 | * along with this program; if not, write to the Free Software |
| 19 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. |
Mike Frysinger | 7031f62 | 2006-05-08 03:20:50 +0000 | [diff] [blame] | 20 | */ |
Denis Vlasenko | af1c843 | 2007-03-26 13:22:35 +0000 | [diff] [blame] | 21 | #include <syslog.h> |
Denis Vlasenko | 1caca34 | 2007-08-02 10:14:29 +0000 | [diff] [blame] | 22 | /* Override ENABLE_FEATURE_PIDFILE - ifupdown needs our pidfile to always exist */ |
| 23 | #define WANT_PIDFILE 1 |
Mike Frysinger | 7031f62 | 2006-05-08 03:20:50 +0000 | [diff] [blame] | 24 | #include "common.h" |
| 25 | #include "dhcpd.h" |
| 26 | #include "dhcpc.h" |
Denis Vlasenko | 5a3395b | 2006-11-18 19:51:32 +0000 | [diff] [blame] | 27 | |
Dan Fandrich | f533ec8 | 2011-06-10 05:17:59 +0200 | [diff] [blame] | 28 | #include <netinet/if_ether.h> |
Denys Vlasenko | 6b24d53 | 2010-03-22 13:42:13 +0100 | [diff] [blame] | 29 | #include <linux/filter.h> |
Alexey Froloff | 3c62bba | 2012-09-17 16:02:44 +0200 | [diff] [blame] | 30 | #include <linux/if_packet.h> |
Denys Vlasenko | 6b24d53 | 2010-03-22 13:42:13 +0100 | [diff] [blame] | 31 | |
Denys Vlasenko | 2017d48 | 2011-11-05 01:24:14 +0100 | [diff] [blame] | 32 | /* "struct client_config_t client_config" is in bb_common_bufsiz1 */ |
Denis Vlasenko | e2d3ded | 2006-11-27 23:43:28 +0000 | [diff] [blame] | 33 | |
Mike Frysinger | 7031f62 | 2006-05-08 03:20:50 +0000 | [diff] [blame] | 34 | |
Keith Young | e6bb8d3 | 2011-03-07 03:18:46 +0100 | [diff] [blame] | 35 | #if ENABLE_LONG_OPTS |
| 36 | static const char udhcpc_longopts[] ALIGN1 = |
| 37 | "clientid-none\0" No_argument "C" |
| 38 | "vendorclass\0" Required_argument "V" |
| 39 | "hostname\0" Required_argument "H" |
| 40 | "fqdn\0" Required_argument "F" |
| 41 | "interface\0" Required_argument "i" |
| 42 | "now\0" No_argument "n" |
| 43 | "pidfile\0" Required_argument "p" |
| 44 | "quit\0" No_argument "q" |
| 45 | "release\0" No_argument "R" |
| 46 | "request\0" Required_argument "r" |
| 47 | "script\0" Required_argument "s" |
| 48 | "timeout\0" Required_argument "T" |
Keith Young | e6bb8d3 | 2011-03-07 03:18:46 +0100 | [diff] [blame] | 49 | "retries\0" Required_argument "t" |
| 50 | "tryagain\0" Required_argument "A" |
| 51 | "syslog\0" No_argument "S" |
| 52 | "request-option\0" Required_argument "O" |
| 53 | "no-default-options\0" No_argument "o" |
| 54 | "foreground\0" No_argument "f" |
| 55 | "background\0" No_argument "b" |
| 56 | "broadcast\0" No_argument "B" |
Michel Stam | 9f41271 | 2014-10-30 11:59:04 +0100 | [diff] [blame^] | 57 | IF_FEATURE_UDHCPC_ARPING("arping\0" Optional_argument "a") |
Keith Young | e6bb8d3 | 2011-03-07 03:18:46 +0100 | [diff] [blame] | 58 | IF_FEATURE_UDHCP_PORT("client-port\0" Required_argument "P") |
| 59 | ; |
| 60 | #endif |
| 61 | /* Must match getopt32 option string order */ |
| 62 | enum { |
| 63 | OPT_C = 1 << 0, |
| 64 | OPT_V = 1 << 1, |
| 65 | OPT_H = 1 << 2, |
| 66 | OPT_h = 1 << 3, |
| 67 | OPT_F = 1 << 4, |
| 68 | OPT_i = 1 << 5, |
| 69 | OPT_n = 1 << 6, |
| 70 | OPT_p = 1 << 7, |
| 71 | OPT_q = 1 << 8, |
| 72 | OPT_R = 1 << 9, |
| 73 | OPT_r = 1 << 10, |
| 74 | OPT_s = 1 << 11, |
| 75 | OPT_T = 1 << 12, |
| 76 | OPT_t = 1 << 13, |
| 77 | OPT_S = 1 << 14, |
| 78 | OPT_A = 1 << 15, |
| 79 | OPT_O = 1 << 16, |
| 80 | OPT_o = 1 << 17, |
| 81 | OPT_x = 1 << 18, |
| 82 | OPT_f = 1 << 19, |
| 83 | OPT_B = 1 << 20, |
| 84 | /* The rest has variable bit positions, need to be clever */ |
| 85 | OPTBIT_B = 20, |
| 86 | USE_FOR_MMU( OPTBIT_b,) |
| 87 | IF_FEATURE_UDHCPC_ARPING(OPTBIT_a,) |
| 88 | IF_FEATURE_UDHCP_PORT( OPTBIT_P,) |
| 89 | USE_FOR_MMU( OPT_b = 1 << OPTBIT_b,) |
| 90 | IF_FEATURE_UDHCPC_ARPING(OPT_a = 1 << OPTBIT_a,) |
| 91 | IF_FEATURE_UDHCP_PORT( OPT_P = 1 << OPTBIT_P,) |
| 92 | }; |
| 93 | |
| 94 | |
Denys Vlasenko | dde8bdc | 2010-03-22 14:29:13 +0100 | [diff] [blame] | 95 | /*** Script execution code ***/ |
| 96 | |
| 97 | /* get a rough idea of how long an option will be (rounding up...) */ |
| 98 | static const uint8_t len_of_option_as_string[] = { |
Denys Vlasenko | 243ddcb | 2010-04-03 17:34:52 +0200 | [diff] [blame] | 99 | [OPTION_IP ] = sizeof("255.255.255.255 "), |
| 100 | [OPTION_IP_PAIR ] = sizeof("255.255.255.255 ") * 2, |
| 101 | [OPTION_STATIC_ROUTES ] = sizeof("255.255.255.255/32 255.255.255.255 "), |
Denys Vlasenko | 1f56e51 | 2011-10-19 22:40:35 +0200 | [diff] [blame] | 102 | [OPTION_6RD ] = sizeof("32 128 ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff 255.255.255.255 "), |
Denys Vlasenko | 243ddcb | 2010-04-03 17:34:52 +0200 | [diff] [blame] | 103 | [OPTION_STRING ] = 1, |
Denys Vlasenko | d2266d4 | 2012-04-22 03:37:01 +0200 | [diff] [blame] | 104 | [OPTION_STRING_HOST ] = 1, |
Denys Vlasenko | dde8bdc | 2010-03-22 14:29:13 +0100 | [diff] [blame] | 105 | #if ENABLE_FEATURE_UDHCP_RFC3397 |
Denys Vlasenko | 243ddcb | 2010-04-03 17:34:52 +0200 | [diff] [blame] | 106 | [OPTION_DNS_STRING ] = 1, /* unused */ |
| 107 | /* Hmmm, this severely overestimates size if SIP_SERVERS option |
| 108 | * is in domain name form: N-byte option in binary form |
| 109 | * mallocs ~16*N bytes. But it is freed almost at once. |
| 110 | */ |
| 111 | [OPTION_SIP_SERVERS ] = sizeof("255.255.255.255 "), |
Denys Vlasenko | dde8bdc | 2010-03-22 14:29:13 +0100 | [diff] [blame] | 112 | #endif |
Denys Vlasenko | 243ddcb | 2010-04-03 17:34:52 +0200 | [diff] [blame] | 113 | // [OPTION_BOOLEAN ] = sizeof("yes "), |
| 114 | [OPTION_U8 ] = sizeof("255 "), |
| 115 | [OPTION_U16 ] = sizeof("65535 "), |
| 116 | // [OPTION_S16 ] = sizeof("-32768 "), |
| 117 | [OPTION_U32 ] = sizeof("4294967295 "), |
| 118 | [OPTION_S32 ] = sizeof("-2147483684 "), |
Denys Vlasenko | dde8bdc | 2010-03-22 14:29:13 +0100 | [diff] [blame] | 119 | }; |
| 120 | |
| 121 | /* note: ip is a pointer to an IP in network order, possibly misaliged */ |
| 122 | static int sprint_nip(char *dest, const char *pre, const uint8_t *ip) |
| 123 | { |
| 124 | return sprintf(dest, "%s%u.%u.%u.%u", pre, ip[0], ip[1], ip[2], ip[3]); |
| 125 | } |
| 126 | |
| 127 | /* really simple implementation, just count the bits */ |
| 128 | static int mton(uint32_t mask) |
| 129 | { |
| 130 | int i = 0; |
| 131 | mask = ntohl(mask); /* 111110000-like bit pattern */ |
| 132 | while (mask) { |
| 133 | i++; |
| 134 | mask <<= 1; |
| 135 | } |
| 136 | return i; |
| 137 | } |
| 138 | |
Denys Vlasenko | 85090c1 | 2014-06-16 00:17:00 +0200 | [diff] [blame] | 139 | #if ENABLE_FEATURE_UDHCPC_SANITIZEOPT |
Denys Vlasenko | 7280d20 | 2011-12-08 16:41:05 +0100 | [diff] [blame] | 140 | /* Check if a given label represents a valid DNS label |
| 141 | * Return pointer to the first character after the label upon success, |
| 142 | * NULL otherwise. |
| 143 | * See RFC1035, 2.3.1 |
| 144 | */ |
| 145 | /* We don't need to be particularly anal. For example, allowing _, hyphen |
| 146 | * at the end, or leading and trailing dots would be ok, since it |
| 147 | * can't be used for attacks. (Leading hyphen can be, if someone uses |
| 148 | * cmd "$hostname" |
| 149 | * in the script: then hostname may be treated as an option) |
| 150 | */ |
| 151 | static const char *valid_domain_label(const char *label) |
| 152 | { |
| 153 | unsigned char ch; |
| 154 | unsigned pos = 0; |
| 155 | |
| 156 | for (;;) { |
| 157 | ch = *label; |
| 158 | if ((ch|0x20) < 'a' || (ch|0x20) > 'z') { |
| 159 | if (pos == 0) { |
| 160 | /* label must begin with letter */ |
| 161 | return NULL; |
| 162 | } |
| 163 | if (ch < '0' || ch > '9') { |
| 164 | if (ch == '\0' || ch == '.') |
| 165 | return label; |
| 166 | /* DNS allows only '-', but we are more permissive */ |
| 167 | if (ch != '-' && ch != '_') |
| 168 | return NULL; |
| 169 | } |
| 170 | } |
| 171 | label++; |
| 172 | pos++; |
| 173 | //Do we want this? |
| 174 | //if (pos > 63) /* NS_MAXLABEL; labels must be 63 chars or less */ |
| 175 | // return NULL; |
| 176 | } |
| 177 | } |
| 178 | |
| 179 | /* Check if a given name represents a valid DNS name */ |
| 180 | /* See RFC1035, 2.3.1 */ |
| 181 | static int good_hostname(const char *name) |
| 182 | { |
| 183 | //const char *start = name; |
| 184 | |
| 185 | for (;;) { |
| 186 | name = valid_domain_label(name); |
| 187 | if (!name) |
| 188 | return 0; |
| 189 | if (!name[0]) |
| 190 | return 1; |
| 191 | //Do we want this? |
| 192 | //return ((name - start) < 1025); /* NS_MAXDNAME */ |
| 193 | name++; |
| 194 | } |
| 195 | } |
Denys Vlasenko | 85090c1 | 2014-06-16 00:17:00 +0200 | [diff] [blame] | 196 | #else |
| 197 | # define good_hostname(name) 1 |
| 198 | #endif |
Denys Vlasenko | 7280d20 | 2011-12-08 16:41:05 +0100 | [diff] [blame] | 199 | |
Denys Vlasenko | dde8bdc | 2010-03-22 14:29:13 +0100 | [diff] [blame] | 200 | /* Create "opt_name=opt_value" string */ |
Denys Vlasenko | c03602b | 2010-04-04 15:28:49 +0200 | [diff] [blame] | 201 | static NOINLINE char *xmalloc_optname_optval(uint8_t *option, const struct dhcp_optflag *optflag, const char *opt_name) |
Denys Vlasenko | dde8bdc | 2010-03-22 14:29:13 +0100 | [diff] [blame] | 202 | { |
| 203 | unsigned upper_length; |
| 204 | int len, type, optlen; |
Denys Vlasenko | dde8bdc | 2010-03-22 14:29:13 +0100 | [diff] [blame] | 205 | char *dest, *ret; |
| 206 | |
Denys Vlasenko | 1dff672 | 2011-10-20 12:29:18 +0200 | [diff] [blame] | 207 | /* option points to OPT_DATA, need to go back to get OPT_LEN */ |
| 208 | len = option[-OPT_DATA + OPT_LEN]; |
Vladislav Grishenko | ad8def2 | 2010-10-17 12:27:50 +0200 | [diff] [blame] | 209 | |
Denys Vlasenko | c03602b | 2010-04-04 15:28:49 +0200 | [diff] [blame] | 210 | type = optflag->flags & OPTION_TYPE_MASK; |
Denys Vlasenko | dde8bdc | 2010-03-22 14:29:13 +0100 | [diff] [blame] | 211 | optlen = dhcp_option_lengths[type]; |
Denys Vlasenko | 1f56e51 | 2011-10-19 22:40:35 +0200 | [diff] [blame] | 212 | upper_length = len_of_option_as_string[type] |
| 213 | * ((unsigned)(len + optlen - 1) / (unsigned)optlen); |
Denys Vlasenko | dde8bdc | 2010-03-22 14:29:13 +0100 | [diff] [blame] | 214 | |
| 215 | dest = ret = xmalloc(upper_length + strlen(opt_name) + 2); |
| 216 | dest += sprintf(ret, "%s=", opt_name); |
| 217 | |
| 218 | while (len >= optlen) { |
| 219 | switch (type) { |
Denys Vlasenko | cd4d78f | 2011-10-20 13:21:55 +0200 | [diff] [blame] | 220 | case OPTION_IP: |
Denys Vlasenko | dde8bdc | 2010-03-22 14:29:13 +0100 | [diff] [blame] | 221 | case OPTION_IP_PAIR: |
| 222 | dest += sprint_nip(dest, "", option); |
Denys Vlasenko | cd4d78f | 2011-10-20 13:21:55 +0200 | [diff] [blame] | 223 | if (type == OPTION_IP) |
| 224 | break; |
| 225 | dest += sprint_nip(dest, "/", option + 4); |
Denys Vlasenko | dde8bdc | 2010-03-22 14:29:13 +0100 | [diff] [blame] | 226 | break; |
Denys Vlasenko | a8f6b99 | 2010-03-26 08:35:24 +0100 | [diff] [blame] | 227 | // case OPTION_BOOLEAN: |
| 228 | // dest += sprintf(dest, *option ? "yes" : "no"); |
| 229 | // break; |
Denys Vlasenko | dde8bdc | 2010-03-22 14:29:13 +0100 | [diff] [blame] | 230 | case OPTION_U8: |
| 231 | dest += sprintf(dest, "%u", *option); |
| 232 | break; |
Denys Vlasenko | 243ddcb | 2010-04-03 17:34:52 +0200 | [diff] [blame] | 233 | // case OPTION_S16: |
| 234 | case OPTION_U16: { |
| 235 | uint16_t val_u16; |
Denys Vlasenko | dde8bdc | 2010-03-22 14:29:13 +0100 | [diff] [blame] | 236 | move_from_unaligned16(val_u16, option); |
| 237 | dest += sprintf(dest, "%u", ntohs(val_u16)); |
| 238 | break; |
Denys Vlasenko | 243ddcb | 2010-04-03 17:34:52 +0200 | [diff] [blame] | 239 | } |
Denys Vlasenko | dde8bdc | 2010-03-22 14:29:13 +0100 | [diff] [blame] | 240 | case OPTION_S32: |
Denys Vlasenko | 243ddcb | 2010-04-03 17:34:52 +0200 | [diff] [blame] | 241 | case OPTION_U32: { |
| 242 | uint32_t val_u32; |
| 243 | move_from_unaligned32(val_u32, option); |
| 244 | dest += sprintf(dest, type == OPTION_U32 ? "%lu" : "%ld", (unsigned long) ntohl(val_u32)); |
Denys Vlasenko | dde8bdc | 2010-03-22 14:29:13 +0100 | [diff] [blame] | 245 | break; |
Denys Vlasenko | 243ddcb | 2010-04-03 17:34:52 +0200 | [diff] [blame] | 246 | } |
Denys Vlasenko | cd4d78f | 2011-10-20 13:21:55 +0200 | [diff] [blame] | 247 | /* Note: options which use 'return' instead of 'break' |
| 248 | * (for example, OPTION_STRING) skip the code which handles |
| 249 | * the case of list of options. |
| 250 | */ |
Denys Vlasenko | dde8bdc | 2010-03-22 14:29:13 +0100 | [diff] [blame] | 251 | case OPTION_STRING: |
Denys Vlasenko | 7280d20 | 2011-12-08 16:41:05 +0100 | [diff] [blame] | 252 | case OPTION_STRING_HOST: |
Denys Vlasenko | dde8bdc | 2010-03-22 14:29:13 +0100 | [diff] [blame] | 253 | memcpy(dest, option, len); |
| 254 | dest[len] = '\0'; |
Denys Vlasenko | 7280d20 | 2011-12-08 16:41:05 +0100 | [diff] [blame] | 255 | if (type == OPTION_STRING_HOST && !good_hostname(dest)) |
| 256 | safe_strncpy(dest, "bad", len); |
Denys Vlasenko | cd4d78f | 2011-10-20 13:21:55 +0200 | [diff] [blame] | 257 | return ret; |
Denys Vlasenko | dde8bdc | 2010-03-22 14:29:13 +0100 | [diff] [blame] | 258 | case OPTION_STATIC_ROUTES: { |
| 259 | /* Option binary format: |
| 260 | * mask [one byte, 0..32] |
| 261 | * ip [big endian, 0..4 bytes depending on mask] |
| 262 | * router [big endian, 4 bytes] |
| 263 | * may be repeated |
| 264 | * |
| 265 | * We convert it to a string "IP/MASK ROUTER IP2/MASK2 ROUTER2" |
| 266 | */ |
| 267 | const char *pfx = ""; |
| 268 | |
| 269 | while (len >= 1 + 4) { /* mask + 0-byte ip + router */ |
| 270 | uint32_t nip; |
| 271 | uint8_t *p; |
| 272 | unsigned mask; |
| 273 | int bytes; |
| 274 | |
| 275 | mask = *option++; |
| 276 | if (mask > 32) |
| 277 | break; |
| 278 | len--; |
| 279 | |
| 280 | nip = 0; |
| 281 | p = (void*) &nip; |
| 282 | bytes = (mask + 7) / 8; /* 0 -> 0, 1..8 -> 1, 9..16 -> 2 etc */ |
| 283 | while (--bytes >= 0) { |
| 284 | *p++ = *option++; |
| 285 | len--; |
| 286 | } |
| 287 | if (len < 4) |
| 288 | break; |
| 289 | |
| 290 | /* print ip/mask */ |
| 291 | dest += sprint_nip(dest, pfx, (void*) &nip); |
| 292 | pfx = " "; |
| 293 | dest += sprintf(dest, "/%u ", mask); |
| 294 | /* print router */ |
| 295 | dest += sprint_nip(dest, "", option); |
| 296 | option += 4; |
| 297 | len -= 4; |
| 298 | } |
| 299 | |
| 300 | return ret; |
| 301 | } |
Denys Vlasenko | 1dff672 | 2011-10-20 12:29:18 +0200 | [diff] [blame] | 302 | case OPTION_6RD: |
Denys Vlasenko | 1f56e51 | 2011-10-19 22:40:35 +0200 | [diff] [blame] | 303 | /* Option binary format (see RFC 5969): |
Denys Vlasenko | 1dff672 | 2011-10-20 12:29:18 +0200 | [diff] [blame] | 304 | * 0 1 2 3 |
| 305 | * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 |
Denys Vlasenko | 1f56e51 | 2011-10-19 22:40:35 +0200 | [diff] [blame] | 306 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 307 | * | OPTION_6RD | option-length | IPv4MaskLen | 6rdPrefixLen | |
| 308 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
Denys Vlasenko | 1f56e51 | 2011-10-19 22:40:35 +0200 | [diff] [blame] | 309 | * | 6rdPrefix | |
Denys Vlasenko | 1dff672 | 2011-10-20 12:29:18 +0200 | [diff] [blame] | 310 | * ... (16 octets) ... |
Denys Vlasenko | 1f56e51 | 2011-10-19 22:40:35 +0200 | [diff] [blame] | 311 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
Denys Vlasenko | 1dff672 | 2011-10-20 12:29:18 +0200 | [diff] [blame] | 312 | * ... 6rdBRIPv4Address(es) ... |
Denys Vlasenko | 1f56e51 | 2011-10-19 22:40:35 +0200 | [diff] [blame] | 313 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
Denys Vlasenko | 1f56e51 | 2011-10-19 22:40:35 +0200 | [diff] [blame] | 314 | * We convert it to a string |
| 315 | * "IPv4MaskLen 6rdPrefixLen 6rdPrefix 6rdBRIPv4Address..." |
Denys Vlasenko | 1dff672 | 2011-10-20 12:29:18 +0200 | [diff] [blame] | 316 | * |
| 317 | * Sanity check: ensure that our length is at least 22 bytes, that |
Denys Vlasenko | 1f56e51 | 2011-10-19 22:40:35 +0200 | [diff] [blame] | 318 | * IPv4MaskLen <= 32, |
| 319 | * 6rdPrefixLen <= 128, |
| 320 | * 6rdPrefixLen + (32 - IPv4MaskLen) <= 128 |
| 321 | * (2nd condition need no check - it follows from 1st and 3rd). |
Denys Vlasenko | 1dff672 | 2011-10-20 12:29:18 +0200 | [diff] [blame] | 322 | * Else, return envvar with empty value ("optname=") |
Denys Vlasenko | 1f56e51 | 2011-10-19 22:40:35 +0200 | [diff] [blame] | 323 | */ |
Denys Vlasenko | 1dff672 | 2011-10-20 12:29:18 +0200 | [diff] [blame] | 324 | if (len >= (1 + 1 + 16 + 4) |
Denys Vlasenko | 1f56e51 | 2011-10-19 22:40:35 +0200 | [diff] [blame] | 325 | && option[0] <= 32 |
| 326 | && (option[1] + 32 - option[0]) <= 128 |
| 327 | ) { |
| 328 | /* IPv4MaskLen */ |
| 329 | dest += sprintf(dest, "%u ", *option++); |
| 330 | /* 6rdPrefixLen */ |
| 331 | dest += sprintf(dest, "%u ", *option++); |
| 332 | /* 6rdPrefix */ |
Denys Vlasenko | 42816c2 | 2011-10-20 10:52:07 +0200 | [diff] [blame] | 333 | dest += sprint_nip6(dest, /* "", */ option); |
Denys Vlasenko | 1f56e51 | 2011-10-19 22:40:35 +0200 | [diff] [blame] | 334 | option += 16; |
Denys Vlasenko | 1dff672 | 2011-10-20 12:29:18 +0200 | [diff] [blame] | 335 | len -= 1 + 1 + 16 + 4; |
| 336 | /* "+ 4" above corresponds to the length of IPv4 addr |
| 337 | * we consume in the loop below */ |
Denys Vlasenko | 1f56e51 | 2011-10-19 22:40:35 +0200 | [diff] [blame] | 338 | while (1) { |
Denys Vlasenko | 1dff672 | 2011-10-20 12:29:18 +0200 | [diff] [blame] | 339 | /* 6rdBRIPv4Address(es) */ |
Denys Vlasenko | 1f56e51 | 2011-10-19 22:40:35 +0200 | [diff] [blame] | 340 | dest += sprint_nip(dest, " ", option); |
| 341 | option += 4; |
Denys Vlasenko | 1dff672 | 2011-10-20 12:29:18 +0200 | [diff] [blame] | 342 | len -= 4; /* do we have yet another 4+ bytes? */ |
Denys Vlasenko | 1f56e51 | 2011-10-19 22:40:35 +0200 | [diff] [blame] | 343 | if (len < 0) |
Denys Vlasenko | 1dff672 | 2011-10-20 12:29:18 +0200 | [diff] [blame] | 344 | break; /* no */ |
Denys Vlasenko | 1f56e51 | 2011-10-19 22:40:35 +0200 | [diff] [blame] | 345 | } |
| 346 | } |
| 347 | |
| 348 | return ret; |
Denys Vlasenko | dde8bdc | 2010-03-22 14:29:13 +0100 | [diff] [blame] | 349 | #if ENABLE_FEATURE_UDHCP_RFC3397 |
Denys Vlasenko | 243ddcb | 2010-04-03 17:34:52 +0200 | [diff] [blame] | 350 | case OPTION_DNS_STRING: |
Denys Vlasenko | dde8bdc | 2010-03-22 14:29:13 +0100 | [diff] [blame] | 351 | /* unpack option into dest; use ret for prefix (i.e., "optname=") */ |
| 352 | dest = dname_dec(option, len, ret); |
| 353 | if (dest) { |
| 354 | free(ret); |
| 355 | return dest; |
| 356 | } |
| 357 | /* error. return "optname=" string */ |
| 358 | return ret; |
Denys Vlasenko | 243ddcb | 2010-04-03 17:34:52 +0200 | [diff] [blame] | 359 | case OPTION_SIP_SERVERS: |
| 360 | /* Option binary format: |
| 361 | * type: byte |
| 362 | * type=0: domain names, dns-compressed |
| 363 | * type=1: IP addrs |
| 364 | */ |
| 365 | option++; |
| 366 | len--; |
| 367 | if (option[-1] == 0) { |
| 368 | dest = dname_dec(option, len, ret); |
| 369 | if (dest) { |
| 370 | free(ret); |
| 371 | return dest; |
| 372 | } |
| 373 | } else |
| 374 | if (option[-1] == 1) { |
| 375 | const char *pfx = ""; |
| 376 | while (1) { |
| 377 | len -= 4; |
| 378 | if (len < 0) |
| 379 | break; |
| 380 | dest += sprint_nip(dest, pfx, option); |
| 381 | pfx = " "; |
| 382 | option += 4; |
| 383 | } |
| 384 | } |
| 385 | return ret; |
Denys Vlasenko | dde8bdc | 2010-03-22 14:29:13 +0100 | [diff] [blame] | 386 | #endif |
Denys Vlasenko | 243ddcb | 2010-04-03 17:34:52 +0200 | [diff] [blame] | 387 | } /* switch */ |
Denys Vlasenko | 1dff672 | 2011-10-20 12:29:18 +0200 | [diff] [blame] | 388 | |
| 389 | /* If we are here, try to format any remaining data |
| 390 | * in the option as another, similarly-formatted option |
| 391 | */ |
Denys Vlasenko | dde8bdc | 2010-03-22 14:29:13 +0100 | [diff] [blame] | 392 | option += optlen; |
| 393 | len -= optlen; |
Vladislav Grishenko | ad8def2 | 2010-10-17 12:27:50 +0200 | [diff] [blame] | 394 | // TODO: it can be a list only if (optflag->flags & OPTION_LIST). |
| 395 | // Should we bail out/warn if we see multi-ip option which is |
| 396 | // not allowed to be such (for example, DHCP_BROADCAST)? - |
Denys Vlasenko | cd4d78f | 2011-10-20 13:21:55 +0200 | [diff] [blame] | 397 | if (len < optlen /* || !(optflag->flags & OPTION_LIST) */) |
Denys Vlasenko | dde8bdc | 2010-03-22 14:29:13 +0100 | [diff] [blame] | 398 | break; |
| 399 | *dest++ = ' '; |
| 400 | *dest = '\0'; |
Denys Vlasenko | 1dff672 | 2011-10-20 12:29:18 +0200 | [diff] [blame] | 401 | } /* while */ |
| 402 | |
Denys Vlasenko | dde8bdc | 2010-03-22 14:29:13 +0100 | [diff] [blame] | 403 | return ret; |
| 404 | } |
| 405 | |
| 406 | /* put all the parameters into the environment */ |
| 407 | static char **fill_envp(struct dhcp_packet *packet) |
| 408 | { |
Denys Vlasenko | b7d19cc | 2010-05-30 23:41:23 +0200 | [diff] [blame] | 409 | int envc; |
Denys Vlasenko | dde8bdc | 2010-03-22 14:29:13 +0100 | [diff] [blame] | 410 | int i; |
| 411 | char **envp, **curr; |
| 412 | const char *opt_name; |
| 413 | uint8_t *temp; |
Denys Vlasenko | b7d19cc | 2010-05-30 23:41:23 +0200 | [diff] [blame] | 414 | uint8_t overload = 0; |
Denys Vlasenko | dde8bdc | 2010-03-22 14:29:13 +0100 | [diff] [blame] | 415 | |
Nigel Hathaway | c37d4c6 | 2011-04-26 02:38:29 +0200 | [diff] [blame] | 416 | #define BITMAP unsigned |
| 417 | #define BBITS (sizeof(BITMAP) * 8) |
| 418 | #define BMASK(i) (1 << (i & (sizeof(BITMAP) * 8 - 1))) |
| 419 | #define FOUND_OPTS(i) (found_opts[(unsigned)i / BBITS]) |
| 420 | BITMAP found_opts[256 / BBITS]; |
| 421 | |
| 422 | memset(found_opts, 0, sizeof(found_opts)); |
| 423 | |
Denys Vlasenko | b7d19cc | 2010-05-30 23:41:23 +0200 | [diff] [blame] | 424 | /* We need 6 elements for: |
| 425 | * "interface=IFACE" |
| 426 | * "ip=N.N.N.N" from packet->yiaddr |
| 427 | * "siaddr=IP" from packet->siaddr_nip (unless 0) |
| 428 | * "boot_file=FILE" from packet->file (unless overloaded) |
| 429 | * "sname=SERVER_HOSTNAME" from packet->sname (unless overloaded) |
| 430 | * terminating NULL |
| 431 | */ |
| 432 | envc = 6; |
| 433 | /* +1 element for each option, +2 for subnet option: */ |
Denys Vlasenko | dde8bdc | 2010-03-22 14:29:13 +0100 | [diff] [blame] | 434 | if (packet) { |
Nigel Hathaway | c37d4c6 | 2011-04-26 02:38:29 +0200 | [diff] [blame] | 435 | /* note: do not search for "pad" (0) and "end" (255) options */ |
Denys Vlasenko | 7280d20 | 2011-12-08 16:41:05 +0100 | [diff] [blame] | 436 | //TODO: change logic to scan packet _once_ |
Nigel Hathaway | c37d4c6 | 2011-04-26 02:38:29 +0200 | [diff] [blame] | 437 | for (i = 1; i < 255; i++) { |
| 438 | temp = udhcp_get_option(packet, i); |
| 439 | if (temp) { |
| 440 | if (i == DHCP_OPTION_OVERLOAD) |
| 441 | overload = *temp; |
| 442 | else if (i == DHCP_SUBNET) |
Denys Vlasenko | fbca0c6 | 2011-10-20 14:24:18 +0200 | [diff] [blame] | 443 | envc++; /* for $mask */ |
Denys Vlasenko | b7d19cc | 2010-05-30 23:41:23 +0200 | [diff] [blame] | 444 | envc++; |
Nigel Hathaway | c37d4c6 | 2011-04-26 02:38:29 +0200 | [diff] [blame] | 445 | /*if (i != DHCP_MESSAGE_TYPE)*/ |
| 446 | FOUND_OPTS(i) |= BMASK(i); |
Denys Vlasenko | dde8bdc | 2010-03-22 14:29:13 +0100 | [diff] [blame] | 447 | } |
| 448 | } |
Denys Vlasenko | dde8bdc | 2010-03-22 14:29:13 +0100 | [diff] [blame] | 449 | } |
Nigel Hathaway | c37d4c6 | 2011-04-26 02:38:29 +0200 | [diff] [blame] | 450 | curr = envp = xzalloc(sizeof(envp[0]) * envc); |
Denys Vlasenko | dde8bdc | 2010-03-22 14:29:13 +0100 | [diff] [blame] | 451 | |
Denys Vlasenko | dde8bdc | 2010-03-22 14:29:13 +0100 | [diff] [blame] | 452 | *curr = xasprintf("interface=%s", client_config.interface); |
| 453 | putenv(*curr++); |
| 454 | |
Denys Vlasenko | b7d19cc | 2010-05-30 23:41:23 +0200 | [diff] [blame] | 455 | if (!packet) |
Denys Vlasenko | dde8bdc | 2010-03-22 14:29:13 +0100 | [diff] [blame] | 456 | return envp; |
| 457 | |
Denys Vlasenko | fbca0c6 | 2011-10-20 14:24:18 +0200 | [diff] [blame] | 458 | /* Export BOOTP fields. Fields we don't (yet?) export: |
| 459 | * uint8_t op; // always BOOTREPLY |
| 460 | * uint8_t htype; // hardware address type. 1 = 10mb ethernet |
| 461 | * uint8_t hlen; // hardware address length |
| 462 | * uint8_t hops; // used by relay agents only |
| 463 | * uint32_t xid; |
| 464 | * uint16_t secs; // elapsed since client began acquisition/renewal |
| 465 | * uint16_t flags; // only one flag so far: bcast. Never set by server |
| 466 | * uint32_t ciaddr; // client IP (usually == yiaddr. can it be different |
| 467 | * // if during renew server wants to give us differn IP?) |
| 468 | * uint32_t gateway_nip; // relay agent IP address |
| 469 | * uint8_t chaddr[16]; // link-layer client hardware address (MAC) |
| 470 | * TODO: export gateway_nip as $giaddr? |
| 471 | */ |
| 472 | /* Most important one: yiaddr as $ip */ |
Denys Vlasenko | dde8bdc | 2010-03-22 14:29:13 +0100 | [diff] [blame] | 473 | *curr = xmalloc(sizeof("ip=255.255.255.255")); |
| 474 | sprint_nip(*curr, "ip=", (uint8_t *) &packet->yiaddr); |
| 475 | putenv(*curr++); |
Denys Vlasenko | fbca0c6 | 2011-10-20 14:24:18 +0200 | [diff] [blame] | 476 | if (packet->siaddr_nip) { |
| 477 | /* IP address of next server to use in bootstrap */ |
| 478 | *curr = xmalloc(sizeof("siaddr=255.255.255.255")); |
| 479 | sprint_nip(*curr, "siaddr=", (uint8_t *) &packet->siaddr_nip); |
| 480 | putenv(*curr++); |
| 481 | } |
| 482 | if (!(overload & FILE_FIELD) && packet->file[0]) { |
| 483 | /* watch out for invalid packets */ |
| 484 | *curr = xasprintf("boot_file=%."DHCP_PKT_FILE_LEN_STR"s", packet->file); |
| 485 | putenv(*curr++); |
| 486 | } |
| 487 | if (!(overload & SNAME_FIELD) && packet->sname[0]) { |
| 488 | /* watch out for invalid packets */ |
| 489 | *curr = xasprintf("sname=%."DHCP_PKT_SNAME_LEN_STR"s", packet->sname); |
| 490 | putenv(*curr++); |
| 491 | } |
Denys Vlasenko | dde8bdc | 2010-03-22 14:29:13 +0100 | [diff] [blame] | 492 | |
Denys Vlasenko | fbca0c6 | 2011-10-20 14:24:18 +0200 | [diff] [blame] | 493 | /* Export known DHCP options */ |
Denys Vlasenko | dde8bdc | 2010-03-22 14:29:13 +0100 | [diff] [blame] | 494 | opt_name = dhcp_option_strings; |
| 495 | i = 0; |
| 496 | while (*opt_name) { |
Nigel Hathaway | c37d4c6 | 2011-04-26 02:38:29 +0200 | [diff] [blame] | 497 | uint8_t code = dhcp_optflags[i].code; |
| 498 | BITMAP *found_ptr = &FOUND_OPTS(code); |
| 499 | BITMAP found_mask = BMASK(code); |
| 500 | if (!(*found_ptr & found_mask)) |
Denys Vlasenko | dde8bdc | 2010-03-22 14:29:13 +0100 | [diff] [blame] | 501 | goto next; |
Nigel Hathaway | c37d4c6 | 2011-04-26 02:38:29 +0200 | [diff] [blame] | 502 | *found_ptr &= ~found_mask; /* leave only unknown options */ |
| 503 | temp = udhcp_get_option(packet, code); |
Denys Vlasenko | c03602b | 2010-04-04 15:28:49 +0200 | [diff] [blame] | 504 | *curr = xmalloc_optname_optval(temp, &dhcp_optflags[i], opt_name); |
Denys Vlasenko | dde8bdc | 2010-03-22 14:29:13 +0100 | [diff] [blame] | 505 | putenv(*curr++); |
Nigel Hathaway | c37d4c6 | 2011-04-26 02:38:29 +0200 | [diff] [blame] | 506 | if (code == DHCP_SUBNET) { |
Denys Vlasenko | b7d19cc | 2010-05-30 23:41:23 +0200 | [diff] [blame] | 507 | /* Subnet option: make things like "$ip/$mask" possible */ |
Denys Vlasenko | dde8bdc | 2010-03-22 14:29:13 +0100 | [diff] [blame] | 508 | uint32_t subnet; |
| 509 | move_from_unaligned32(subnet, temp); |
Denys Vlasenko | fbca0c6 | 2011-10-20 14:24:18 +0200 | [diff] [blame] | 510 | *curr = xasprintf("mask=%u", mton(subnet)); |
Denys Vlasenko | dde8bdc | 2010-03-22 14:29:13 +0100 | [diff] [blame] | 511 | putenv(*curr++); |
| 512 | } |
| 513 | next: |
| 514 | opt_name += strlen(opt_name) + 1; |
| 515 | i++; |
| 516 | } |
Denys Vlasenko | fbca0c6 | 2011-10-20 14:24:18 +0200 | [diff] [blame] | 517 | /* Export unknown options */ |
Nigel Hathaway | c37d4c6 | 2011-04-26 02:38:29 +0200 | [diff] [blame] | 518 | for (i = 0; i < 256;) { |
| 519 | BITMAP bitmap = FOUND_OPTS(i); |
| 520 | if (!bitmap) { |
| 521 | i += BBITS; |
| 522 | continue; |
| 523 | } |
| 524 | if (bitmap & BMASK(i)) { |
| 525 | unsigned len, ofs; |
| 526 | |
| 527 | temp = udhcp_get_option(packet, i); |
| 528 | /* udhcp_get_option returns ptr to data portion, |
| 529 | * need to go back to get len |
| 530 | */ |
| 531 | len = temp[-OPT_DATA + OPT_LEN]; |
| 532 | *curr = xmalloc(sizeof("optNNN=") + 1 + len*2); |
| 533 | ofs = sprintf(*curr, "opt%u=", i); |
Denys Vlasenko | 1f56e51 | 2011-10-19 22:40:35 +0200 | [diff] [blame] | 534 | *bin2hex(*curr + ofs, (void*) temp, len) = '\0'; |
Nigel Hathaway | c37d4c6 | 2011-04-26 02:38:29 +0200 | [diff] [blame] | 535 | putenv(*curr++); |
| 536 | } |
| 537 | i++; |
| 538 | } |
Denys Vlasenko | fbca0c6 | 2011-10-20 14:24:18 +0200 | [diff] [blame] | 539 | |
Denys Vlasenko | dde8bdc | 2010-03-22 14:29:13 +0100 | [diff] [blame] | 540 | return envp; |
| 541 | } |
| 542 | |
| 543 | /* Call a script with a par file and env vars */ |
| 544 | static void udhcp_run_script(struct dhcp_packet *packet, const char *name) |
| 545 | { |
| 546 | char **envp, **curr; |
| 547 | char *argv[3]; |
| 548 | |
Denys Vlasenko | dde8bdc | 2010-03-22 14:29:13 +0100 | [diff] [blame] | 549 | envp = fill_envp(packet); |
| 550 | |
| 551 | /* call script */ |
| 552 | log1("Executing %s %s", client_config.script, name); |
| 553 | argv[0] = (char*) client_config.script; |
| 554 | argv[1] = (char*) name; |
| 555 | argv[2] = NULL; |
| 556 | spawn_and_wait(argv); |
| 557 | |
| 558 | for (curr = envp; *curr; curr++) { |
| 559 | log2(" %s", *curr); |
Denys Vlasenko | dd8adde | 2010-06-24 05:00:50 +0200 | [diff] [blame] | 560 | bb_unsetenv_and_free(*curr); |
Denys Vlasenko | dde8bdc | 2010-03-22 14:29:13 +0100 | [diff] [blame] | 561 | } |
| 562 | free(envp); |
| 563 | } |
| 564 | |
| 565 | |
| 566 | /*** Sending/receiving packets ***/ |
| 567 | |
Denys Vlasenko | 8d11445 | 2010-03-22 13:44:09 +0100 | [diff] [blame] | 568 | static ALWAYS_INLINE uint32_t random_xid(void) |
Denys Vlasenko | 501e35c | 2010-03-22 13:43:12 +0100 | [diff] [blame] | 569 | { |
Denys Vlasenko | 501e35c | 2010-03-22 13:43:12 +0100 | [diff] [blame] | 570 | return rand(); |
| 571 | } |
| 572 | |
| 573 | /* Initialize the packet with the proper defaults */ |
| 574 | static void init_packet(struct dhcp_packet *packet, char type) |
| 575 | { |
Denys Vlasenko | 9ac5596 | 2011-03-12 05:37:54 +0100 | [diff] [blame] | 576 | uint16_t secs; |
| 577 | |
Denys Vlasenko | b3af65b | 2010-10-20 21:37:23 +0200 | [diff] [blame] | 578 | /* Fill in: op, htype, hlen, cookie fields; message type option: */ |
Denys Vlasenko | 501e35c | 2010-03-22 13:43:12 +0100 | [diff] [blame] | 579 | udhcp_init_header(packet, type); |
Denys Vlasenko | b3af65b | 2010-10-20 21:37:23 +0200 | [diff] [blame] | 580 | |
| 581 | packet->xid = random_xid(); |
| 582 | |
Denys Vlasenko | 9ac5596 | 2011-03-12 05:37:54 +0100 | [diff] [blame] | 583 | client_config.last_secs = monotonic_sec(); |
| 584 | if (client_config.first_secs == 0) |
| 585 | client_config.first_secs = client_config.last_secs; |
| 586 | secs = client_config.last_secs - client_config.first_secs; |
| 587 | packet->secs = htons(secs); |
| 588 | |
Denys Vlasenko | 501e35c | 2010-03-22 13:43:12 +0100 | [diff] [blame] | 589 | memcpy(packet->chaddr, client_config.client_mac, 6); |
| 590 | if (client_config.clientid) |
Denys Vlasenko | 7724c76 | 2010-03-26 09:32:09 +0100 | [diff] [blame] | 591 | udhcp_add_binary_option(packet, client_config.clientid); |
Denys Vlasenko | 501e35c | 2010-03-22 13:43:12 +0100 | [diff] [blame] | 592 | } |
| 593 | |
Denys Vlasenko | 7e6add1 | 2010-03-25 20:32:38 +0100 | [diff] [blame] | 594 | static void add_client_options(struct dhcp_packet *packet) |
Denys Vlasenko | 501e35c | 2010-03-22 13:43:12 +0100 | [diff] [blame] | 595 | { |
Denys Vlasenko | b3af65b | 2010-10-20 21:37:23 +0200 | [diff] [blame] | 596 | int i, end, len; |
| 597 | |
| 598 | udhcp_add_simple_option(packet, DHCP_MAX_SIZE, htons(IP_UDP_DHCP_SIZE)); |
Denys Vlasenko | b3af65b | 2010-10-20 21:37:23 +0200 | [diff] [blame] | 599 | |
Denys Vlasenko | 7724c76 | 2010-03-26 09:32:09 +0100 | [diff] [blame] | 600 | /* Add a "param req" option with the list of options we'd like to have |
Denys Vlasenko | a8f6b99 | 2010-03-26 08:35:24 +0100 | [diff] [blame] | 601 | * from stubborn DHCP servers. Pull the data from the struct in common.c. |
Denys Vlasenko | 7e6add1 | 2010-03-25 20:32:38 +0100 | [diff] [blame] | 602 | * No bounds checking because it goes towards the head of the packet. */ |
Denys Vlasenko | b3af65b | 2010-10-20 21:37:23 +0200 | [diff] [blame] | 603 | end = udhcp_end_option(packet->options); |
| 604 | len = 0; |
Denys Vlasenko | 293c945 | 2012-07-27 13:25:07 +0200 | [diff] [blame] | 605 | for (i = 1; i < DHCP_END; i++) { |
| 606 | if (client_config.opt_mask[i >> 3] & (1 << (i & 7))) { |
| 607 | packet->options[end + OPT_DATA + len] = i; |
Denys Vlasenko | 501e35c | 2010-03-22 13:43:12 +0100 | [diff] [blame] | 608 | len++; |
| 609 | } |
| 610 | } |
| 611 | if (len) { |
| 612 | packet->options[end + OPT_CODE] = DHCP_PARAM_REQ; |
| 613 | packet->options[end + OPT_LEN] = len; |
| 614 | packet->options[end + OPT_DATA + len] = DHCP_END; |
| 615 | } |
Denys Vlasenko | 7e6add1 | 2010-03-25 20:32:38 +0100 | [diff] [blame] | 616 | |
Denys Vlasenko | c72c1d7 | 2010-10-20 22:08:16 +0200 | [diff] [blame] | 617 | if (client_config.vendorclass) |
| 618 | udhcp_add_binary_option(packet, client_config.vendorclass); |
| 619 | if (client_config.hostname) |
| 620 | udhcp_add_binary_option(packet, client_config.hostname); |
| 621 | if (client_config.fqdn) |
| 622 | udhcp_add_binary_option(packet, client_config.fqdn); |
| 623 | |
Keith Young | e6bb8d3 | 2011-03-07 03:18:46 +0100 | [diff] [blame] | 624 | /* Request broadcast replies if we have no IP addr */ |
| 625 | if ((option_mask32 & OPT_B) && packet->ciaddr == 0) |
| 626 | packet->flags |= htons(BROADCAST_FLAG); |
| 627 | |
Denys Vlasenko | 7e6add1 | 2010-03-25 20:32:38 +0100 | [diff] [blame] | 628 | /* Add -x options if any */ |
| 629 | { |
| 630 | struct option_set *curr = client_config.options; |
| 631 | while (curr) { |
Denys Vlasenko | 7724c76 | 2010-03-26 09:32:09 +0100 | [diff] [blame] | 632 | udhcp_add_binary_option(packet, curr->data); |
Denys Vlasenko | 7e6add1 | 2010-03-25 20:32:38 +0100 | [diff] [blame] | 633 | curr = curr->next; |
| 634 | } |
| 635 | // if (client_config.sname) |
| 636 | // strncpy((char*)packet->sname, client_config.sname, sizeof(packet->sname) - 1); |
| 637 | // if (client_config.boot_file) |
| 638 | // strncpy((char*)packet->file, client_config.boot_file, sizeof(packet->file) - 1); |
| 639 | } |
Denys Vlasenko | 2017d48 | 2011-11-05 01:24:14 +0100 | [diff] [blame] | 640 | |
| 641 | // This will be needed if we remove -V VENDOR_STR in favor of |
| 642 | // -x vendor:VENDOR_STR |
| 643 | //if (!udhcp_find_option(packet.options, DHCP_VENDOR)) |
| 644 | // /* not set, set the default vendor ID */ |
| 645 | // ...add (DHCP_VENDOR, "udhcp "BB_VER) opt... |
Denys Vlasenko | 501e35c | 2010-03-22 13:43:12 +0100 | [diff] [blame] | 646 | } |
| 647 | |
| 648 | /* RFC 2131 |
| 649 | * 4.4.4 Use of broadcast and unicast |
| 650 | * |
| 651 | * The DHCP client broadcasts DHCPDISCOVER, DHCPREQUEST and DHCPINFORM |
| 652 | * messages, unless the client knows the address of a DHCP server. |
| 653 | * The client unicasts DHCPRELEASE messages to the server. Because |
| 654 | * the client is declining the use of the IP address supplied by the server, |
| 655 | * the client broadcasts DHCPDECLINE messages. |
| 656 | * |
| 657 | * When the DHCP client knows the address of a DHCP server, in either |
| 658 | * INIT or REBOOTING state, the client may use that address |
| 659 | * in the DHCPDISCOVER or DHCPREQUEST rather than the IP broadcast address. |
| 660 | * The client may also use unicast to send DHCPINFORM messages |
| 661 | * to a known DHCP server. If the client receives no response to DHCP |
| 662 | * messages sent to the IP address of a known DHCP server, the DHCP |
| 663 | * client reverts to using the IP broadcast address. |
| 664 | */ |
| 665 | |
| 666 | static int raw_bcast_from_client_config_ifindex(struct dhcp_packet *packet) |
| 667 | { |
| 668 | return udhcp_send_raw_packet(packet, |
| 669 | /*src*/ INADDR_ANY, CLIENT_PORT, |
| 670 | /*dst*/ INADDR_BROADCAST, SERVER_PORT, MAC_BCAST_ADDR, |
| 671 | client_config.ifindex); |
| 672 | } |
| 673 | |
Denys Vlasenko | 8d3efaf | 2013-11-03 19:20:54 +0100 | [diff] [blame] | 674 | static int bcast_or_ucast(struct dhcp_packet *packet, uint32_t ciaddr, uint32_t server) |
| 675 | { |
| 676 | if (server) |
| 677 | return udhcp_send_kernel_packet(packet, |
| 678 | ciaddr, CLIENT_PORT, |
| 679 | server, SERVER_PORT); |
| 680 | return raw_bcast_from_client_config_ifindex(packet); |
| 681 | } |
| 682 | |
Denys Vlasenko | 501e35c | 2010-03-22 13:43:12 +0100 | [diff] [blame] | 683 | /* Broadcast a DHCP discover packet to the network, with an optionally requested IP */ |
Denys Vlasenko | 0bb35e1 | 2010-10-21 12:33:10 +0200 | [diff] [blame] | 684 | /* NOINLINE: limit stack usage in caller */ |
Denys Vlasenko | c72c1d7 | 2010-10-20 22:08:16 +0200 | [diff] [blame] | 685 | static NOINLINE int send_discover(uint32_t xid, uint32_t requested) |
Denys Vlasenko | 501e35c | 2010-03-22 13:43:12 +0100 | [diff] [blame] | 686 | { |
| 687 | struct dhcp_packet packet; |
| 688 | |
Denys Vlasenko | b3af65b | 2010-10-20 21:37:23 +0200 | [diff] [blame] | 689 | /* Fill in: op, htype, hlen, cookie, chaddr fields, |
| 690 | * random xid field (we override it below), |
| 691 | * client-id option (unless -C), message type option: |
| 692 | */ |
Denys Vlasenko | 501e35c | 2010-03-22 13:43:12 +0100 | [diff] [blame] | 693 | init_packet(&packet, DHCPDISCOVER); |
Denys Vlasenko | b3af65b | 2010-10-20 21:37:23 +0200 | [diff] [blame] | 694 | |
Denys Vlasenko | 501e35c | 2010-03-22 13:43:12 +0100 | [diff] [blame] | 695 | packet.xid = xid; |
| 696 | if (requested) |
Denys Vlasenko | 7724c76 | 2010-03-26 09:32:09 +0100 | [diff] [blame] | 697 | udhcp_add_simple_option(&packet, DHCP_REQUESTED_IP, requested); |
Denys Vlasenko | b3af65b | 2010-10-20 21:37:23 +0200 | [diff] [blame] | 698 | |
| 699 | /* Add options: maxsize, |
| 700 | * optionally: hostname, fqdn, vendorclass, |
| 701 | * "param req" option according to -O, options specified with -x |
| 702 | */ |
Denys Vlasenko | 7e6add1 | 2010-03-25 20:32:38 +0100 | [diff] [blame] | 703 | add_client_options(&packet); |
Denys Vlasenko | 501e35c | 2010-03-22 13:43:12 +0100 | [diff] [blame] | 704 | |
| 705 | bb_info_msg("Sending discover..."); |
| 706 | return raw_bcast_from_client_config_ifindex(&packet); |
| 707 | } |
| 708 | |
| 709 | /* Broadcast a DHCP request message */ |
| 710 | /* RFC 2131 3.1 paragraph 3: |
| 711 | * "The client _broadcasts_ a DHCPREQUEST message..." |
| 712 | */ |
Denys Vlasenko | 0bb35e1 | 2010-10-21 12:33:10 +0200 | [diff] [blame] | 713 | /* NOINLINE: limit stack usage in caller */ |
Denys Vlasenko | c72c1d7 | 2010-10-20 22:08:16 +0200 | [diff] [blame] | 714 | static NOINLINE int send_select(uint32_t xid, uint32_t server, uint32_t requested) |
Denys Vlasenko | 501e35c | 2010-03-22 13:43:12 +0100 | [diff] [blame] | 715 | { |
| 716 | struct dhcp_packet packet; |
| 717 | struct in_addr addr; |
| 718 | |
Denys Vlasenko | b3af65b | 2010-10-20 21:37:23 +0200 | [diff] [blame] | 719 | /* |
| 720 | * RFC 2131 4.3.2 DHCPREQUEST message |
| 721 | * ... |
| 722 | * If the DHCPREQUEST message contains a 'server identifier' |
| 723 | * option, the message is in response to a DHCPOFFER message. |
| 724 | * Otherwise, the message is a request to verify or extend an |
| 725 | * existing lease. If the client uses a 'client identifier' |
| 726 | * in a DHCPREQUEST message, it MUST use that same 'client identifier' |
| 727 | * in all subsequent messages. If the client included a list |
| 728 | * of requested parameters in a DHCPDISCOVER message, it MUST |
| 729 | * include that list in all subsequent messages. |
| 730 | */ |
| 731 | /* Fill in: op, htype, hlen, cookie, chaddr fields, |
| 732 | * random xid field (we override it below), |
| 733 | * client-id option (unless -C), message type option: |
| 734 | */ |
Denys Vlasenko | 501e35c | 2010-03-22 13:43:12 +0100 | [diff] [blame] | 735 | init_packet(&packet, DHCPREQUEST); |
Denys Vlasenko | b3af65b | 2010-10-20 21:37:23 +0200 | [diff] [blame] | 736 | |
Denys Vlasenko | 501e35c | 2010-03-22 13:43:12 +0100 | [diff] [blame] | 737 | packet.xid = xid; |
Denys Vlasenko | 7724c76 | 2010-03-26 09:32:09 +0100 | [diff] [blame] | 738 | udhcp_add_simple_option(&packet, DHCP_REQUESTED_IP, requested); |
Denys Vlasenko | b3af65b | 2010-10-20 21:37:23 +0200 | [diff] [blame] | 739 | |
Denys Vlasenko | 7724c76 | 2010-03-26 09:32:09 +0100 | [diff] [blame] | 740 | udhcp_add_simple_option(&packet, DHCP_SERVER_ID, server); |
Denys Vlasenko | b3af65b | 2010-10-20 21:37:23 +0200 | [diff] [blame] | 741 | |
| 742 | /* Add options: maxsize, |
| 743 | * optionally: hostname, fqdn, vendorclass, |
| 744 | * "param req" option according to -O, and options specified with -x |
| 745 | */ |
Denys Vlasenko | 7e6add1 | 2010-03-25 20:32:38 +0100 | [diff] [blame] | 746 | add_client_options(&packet); |
Denys Vlasenko | 501e35c | 2010-03-22 13:43:12 +0100 | [diff] [blame] | 747 | |
| 748 | addr.s_addr = requested; |
| 749 | bb_info_msg("Sending select for %s...", inet_ntoa(addr)); |
| 750 | return raw_bcast_from_client_config_ifindex(&packet); |
| 751 | } |
| 752 | |
| 753 | /* Unicast or broadcast a DHCP renew message */ |
Denys Vlasenko | 0bb35e1 | 2010-10-21 12:33:10 +0200 | [diff] [blame] | 754 | /* NOINLINE: limit stack usage in caller */ |
| 755 | static NOINLINE int send_renew(uint32_t xid, uint32_t server, uint32_t ciaddr) |
Denys Vlasenko | 501e35c | 2010-03-22 13:43:12 +0100 | [diff] [blame] | 756 | { |
| 757 | struct dhcp_packet packet; |
| 758 | |
Denys Vlasenko | b3af65b | 2010-10-20 21:37:23 +0200 | [diff] [blame] | 759 | /* |
| 760 | * RFC 2131 4.3.2 DHCPREQUEST message |
| 761 | * ... |
| 762 | * DHCPREQUEST generated during RENEWING state: |
| 763 | * |
| 764 | * 'server identifier' MUST NOT be filled in, 'requested IP address' |
| 765 | * option MUST NOT be filled in, 'ciaddr' MUST be filled in with |
| 766 | * client's IP address. In this situation, the client is completely |
| 767 | * configured, and is trying to extend its lease. This message will |
| 768 | * be unicast, so no relay agents will be involved in its |
| 769 | * transmission. Because 'giaddr' is therefore not filled in, the |
| 770 | * DHCP server will trust the value in 'ciaddr', and use it when |
| 771 | * replying to the client. |
| 772 | */ |
| 773 | /* Fill in: op, htype, hlen, cookie, chaddr fields, |
| 774 | * random xid field (we override it below), |
| 775 | * client-id option (unless -C), message type option: |
| 776 | */ |
Denys Vlasenko | 501e35c | 2010-03-22 13:43:12 +0100 | [diff] [blame] | 777 | init_packet(&packet, DHCPREQUEST); |
Denys Vlasenko | b3af65b | 2010-10-20 21:37:23 +0200 | [diff] [blame] | 778 | |
Denys Vlasenko | 501e35c | 2010-03-22 13:43:12 +0100 | [diff] [blame] | 779 | packet.xid = xid; |
| 780 | packet.ciaddr = ciaddr; |
Denys Vlasenko | b3af65b | 2010-10-20 21:37:23 +0200 | [diff] [blame] | 781 | |
| 782 | /* Add options: maxsize, |
| 783 | * optionally: hostname, fqdn, vendorclass, |
| 784 | * "param req" option according to -O, and options specified with -x |
| 785 | */ |
Denys Vlasenko | 7e6add1 | 2010-03-25 20:32:38 +0100 | [diff] [blame] | 786 | add_client_options(&packet); |
Denys Vlasenko | 501e35c | 2010-03-22 13:43:12 +0100 | [diff] [blame] | 787 | |
| 788 | bb_info_msg("Sending renew..."); |
Denys Vlasenko | 8d3efaf | 2013-11-03 19:20:54 +0100 | [diff] [blame] | 789 | return bcast_or_ucast(&packet, ciaddr, server); |
Denys Vlasenko | 501e35c | 2010-03-22 13:43:12 +0100 | [diff] [blame] | 790 | } |
| 791 | |
| 792 | #if ENABLE_FEATURE_UDHCPC_ARPING |
| 793 | /* Broadcast a DHCP decline message */ |
Denys Vlasenko | 0bb35e1 | 2010-10-21 12:33:10 +0200 | [diff] [blame] | 794 | /* NOINLINE: limit stack usage in caller */ |
Denys Vlasenko | 860491c | 2011-11-18 02:09:13 +0100 | [diff] [blame] | 795 | static NOINLINE int send_decline(/*uint32_t xid,*/ uint32_t server, uint32_t requested) |
Denys Vlasenko | 501e35c | 2010-03-22 13:43:12 +0100 | [diff] [blame] | 796 | { |
| 797 | struct dhcp_packet packet; |
| 798 | |
Denys Vlasenko | b3af65b | 2010-10-20 21:37:23 +0200 | [diff] [blame] | 799 | /* Fill in: op, htype, hlen, cookie, chaddr, random xid fields, |
| 800 | * client-id option (unless -C), message type option: |
| 801 | */ |
Denys Vlasenko | 501e35c | 2010-03-22 13:43:12 +0100 | [diff] [blame] | 802 | init_packet(&packet, DHCPDECLINE); |
Denys Vlasenko | b3af65b | 2010-10-20 21:37:23 +0200 | [diff] [blame] | 803 | |
Denys Vlasenko | 860491c | 2011-11-18 02:09:13 +0100 | [diff] [blame] | 804 | #if 0 |
Denys Vlasenko | b3af65b | 2010-10-20 21:37:23 +0200 | [diff] [blame] | 805 | /* RFC 2131 says DHCPDECLINE's xid is randomly selected by client, |
| 806 | * but in case the server is buggy and wants DHCPDECLINE's xid |
| 807 | * to match the xid which started entire handshake, |
| 808 | * we use the same xid we used in initial DHCPDISCOVER: |
| 809 | */ |
Denys Vlasenko | 501e35c | 2010-03-22 13:43:12 +0100 | [diff] [blame] | 810 | packet.xid = xid; |
Denys Vlasenko | 860491c | 2011-11-18 02:09:13 +0100 | [diff] [blame] | 811 | #endif |
Denys Vlasenko | b3af65b | 2010-10-20 21:37:23 +0200 | [diff] [blame] | 812 | /* DHCPDECLINE uses "requested ip", not ciaddr, to store offered IP */ |
Denys Vlasenko | 7724c76 | 2010-03-26 09:32:09 +0100 | [diff] [blame] | 813 | udhcp_add_simple_option(&packet, DHCP_REQUESTED_IP, requested); |
Denys Vlasenko | b3af65b | 2010-10-20 21:37:23 +0200 | [diff] [blame] | 814 | |
Denys Vlasenko | 7724c76 | 2010-03-26 09:32:09 +0100 | [diff] [blame] | 815 | udhcp_add_simple_option(&packet, DHCP_SERVER_ID, server); |
Denys Vlasenko | 501e35c | 2010-03-22 13:43:12 +0100 | [diff] [blame] | 816 | |
| 817 | bb_info_msg("Sending decline..."); |
| 818 | return raw_bcast_from_client_config_ifindex(&packet); |
| 819 | } |
| 820 | #endif |
| 821 | |
| 822 | /* Unicast a DHCP release message */ |
| 823 | static int send_release(uint32_t server, uint32_t ciaddr) |
| 824 | { |
| 825 | struct dhcp_packet packet; |
| 826 | |
Denys Vlasenko | b3af65b | 2010-10-20 21:37:23 +0200 | [diff] [blame] | 827 | /* Fill in: op, htype, hlen, cookie, chaddr, random xid fields, |
| 828 | * client-id option (unless -C), message type option: |
| 829 | */ |
Denys Vlasenko | 501e35c | 2010-03-22 13:43:12 +0100 | [diff] [blame] | 830 | init_packet(&packet, DHCPRELEASE); |
Denys Vlasenko | b3af65b | 2010-10-20 21:37:23 +0200 | [diff] [blame] | 831 | |
| 832 | /* DHCPRELEASE uses ciaddr, not "requested ip", to store IP being released */ |
Denys Vlasenko | 501e35c | 2010-03-22 13:43:12 +0100 | [diff] [blame] | 833 | packet.ciaddr = ciaddr; |
| 834 | |
Denys Vlasenko | 7724c76 | 2010-03-26 09:32:09 +0100 | [diff] [blame] | 835 | udhcp_add_simple_option(&packet, DHCP_SERVER_ID, server); |
Denys Vlasenko | 501e35c | 2010-03-22 13:43:12 +0100 | [diff] [blame] | 836 | |
| 837 | bb_info_msg("Sending release..."); |
Denys Vlasenko | 8d3efaf | 2013-11-03 19:20:54 +0100 | [diff] [blame] | 838 | /* Note: normally we unicast here since "server" is not zero. |
| 839 | * However, there _are_ people who run "address-less" DHCP servers, |
| 840 | * and reportedly ISC dhcp client and Windows allow that. |
| 841 | */ |
| 842 | return bcast_or_ucast(&packet, ciaddr, server); |
Denys Vlasenko | 501e35c | 2010-03-22 13:43:12 +0100 | [diff] [blame] | 843 | } |
| 844 | |
| 845 | /* Returns -1 on errors that are fatal for the socket, -2 for those that aren't */ |
Denys Vlasenko | 0bb35e1 | 2010-10-21 12:33:10 +0200 | [diff] [blame] | 846 | /* NOINLINE: limit stack usage in caller */ |
Denys Vlasenko | 501e35c | 2010-03-22 13:43:12 +0100 | [diff] [blame] | 847 | static NOINLINE int udhcp_recv_raw_packet(struct dhcp_packet *dhcp_pkt, int fd) |
| 848 | { |
| 849 | int bytes; |
| 850 | struct ip_udp_dhcp_packet packet; |
| 851 | uint16_t check; |
Alexey Froloff | 3c62bba | 2012-09-17 16:02:44 +0200 | [diff] [blame] | 852 | unsigned char cmsgbuf[CMSG_LEN(sizeof(struct tpacket_auxdata))]; |
| 853 | struct iovec iov; |
| 854 | struct msghdr msg; |
| 855 | struct cmsghdr *cmsg; |
Denys Vlasenko | 501e35c | 2010-03-22 13:43:12 +0100 | [diff] [blame] | 856 | |
Alexey Froloff | 3c62bba | 2012-09-17 16:02:44 +0200 | [diff] [blame] | 857 | /* used to use just safe_read(fd, &packet, sizeof(packet)) |
| 858 | * but we need to check for TP_STATUS_CSUMNOTREADY :( |
| 859 | */ |
| 860 | iov.iov_base = &packet; |
| 861 | iov.iov_len = sizeof(packet); |
| 862 | memset(&msg, 0, sizeof(msg)); |
| 863 | msg.msg_iov = &iov; |
| 864 | msg.msg_iovlen = 1; |
| 865 | msg.msg_control = cmsgbuf; |
| 866 | msg.msg_controllen = sizeof(cmsgbuf); |
| 867 | for (;;) { |
| 868 | bytes = recvmsg(fd, &msg, 0); |
| 869 | if (bytes < 0) { |
| 870 | if (errno == EINTR) |
| 871 | continue; |
| 872 | log1("Packet read error, ignoring"); |
| 873 | /* NB: possible down interface, etc. Caller should pause. */ |
| 874 | return bytes; /* returns -1 */ |
| 875 | } |
| 876 | break; |
Denys Vlasenko | 501e35c | 2010-03-22 13:43:12 +0100 | [diff] [blame] | 877 | } |
| 878 | |
| 879 | if (bytes < (int) (sizeof(packet.ip) + sizeof(packet.udp))) { |
| 880 | log1("Packet is too short, ignoring"); |
| 881 | return -2; |
| 882 | } |
| 883 | |
| 884 | if (bytes < ntohs(packet.ip.tot_len)) { |
| 885 | /* packet is bigger than sizeof(packet), we did partial read */ |
| 886 | log1("Oversized packet, ignoring"); |
| 887 | return -2; |
| 888 | } |
| 889 | |
| 890 | /* ignore any extra garbage bytes */ |
| 891 | bytes = ntohs(packet.ip.tot_len); |
| 892 | |
| 893 | /* make sure its the right packet for us, and that it passes sanity checks */ |
Denys Vlasenko | 7981d79 | 2011-10-20 10:34:05 +0200 | [diff] [blame] | 894 | if (packet.ip.protocol != IPPROTO_UDP |
| 895 | || packet.ip.version != IPVERSION |
Denys Vlasenko | 501e35c | 2010-03-22 13:43:12 +0100 | [diff] [blame] | 896 | || packet.ip.ihl != (sizeof(packet.ip) >> 2) |
| 897 | || packet.udp.dest != htons(CLIENT_PORT) |
| 898 | /* || bytes > (int) sizeof(packet) - can't happen */ |
| 899 | || ntohs(packet.udp.len) != (uint16_t)(bytes - sizeof(packet.ip)) |
| 900 | ) { |
| 901 | log1("Unrelated/bogus packet, ignoring"); |
| 902 | return -2; |
| 903 | } |
| 904 | |
| 905 | /* verify IP checksum */ |
| 906 | check = packet.ip.check; |
| 907 | packet.ip.check = 0; |
Baruch Siach | e8f3633 | 2011-09-07 17:52:37 +0200 | [diff] [blame] | 908 | if (check != inet_cksum((uint16_t *)&packet.ip, sizeof(packet.ip))) { |
Denys Vlasenko | 501e35c | 2010-03-22 13:43:12 +0100 | [diff] [blame] | 909 | log1("Bad IP header checksum, ignoring"); |
| 910 | return -2; |
| 911 | } |
| 912 | |
Alexey Froloff | 3c62bba | 2012-09-17 16:02:44 +0200 | [diff] [blame] | 913 | for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) { |
| 914 | if (cmsg->cmsg_level == SOL_PACKET |
| 915 | && cmsg->cmsg_type == PACKET_AUXDATA |
| 916 | ) { |
| 917 | /* some VMs don't checksum UDP and TCP data |
| 918 | * they send to the same physical machine, |
| 919 | * here we detect this case: |
| 920 | */ |
| 921 | struct tpacket_auxdata *aux = (void *)CMSG_DATA(cmsg); |
| 922 | if (aux->tp_status & TP_STATUS_CSUMNOTREADY) |
| 923 | goto skip_udp_sum_check; |
| 924 | } |
| 925 | } |
| 926 | |
Denys Vlasenko | 501e35c | 2010-03-22 13:43:12 +0100 | [diff] [blame] | 927 | /* verify UDP checksum. IP header has to be modified for this */ |
| 928 | memset(&packet.ip, 0, offsetof(struct iphdr, protocol)); |
| 929 | /* ip.xx fields which are not memset: protocol, check, saddr, daddr */ |
| 930 | packet.ip.tot_len = packet.udp.len; /* yes, this is needed */ |
| 931 | check = packet.udp.check; |
| 932 | packet.udp.check = 0; |
Baruch Siach | e8f3633 | 2011-09-07 17:52:37 +0200 | [diff] [blame] | 933 | if (check && check != inet_cksum((uint16_t *)&packet, bytes)) { |
Denys Vlasenko | 501e35c | 2010-03-22 13:43:12 +0100 | [diff] [blame] | 934 | log1("Packet with bad UDP checksum received, ignoring"); |
| 935 | return -2; |
| 936 | } |
Alexey Froloff | 3c62bba | 2012-09-17 16:02:44 +0200 | [diff] [blame] | 937 | skip_udp_sum_check: |
Denys Vlasenko | 501e35c | 2010-03-22 13:43:12 +0100 | [diff] [blame] | 938 | |
Denys Vlasenko | 7981d79 | 2011-10-20 10:34:05 +0200 | [diff] [blame] | 939 | if (packet.data.cookie != htonl(DHCP_MAGIC)) { |
Denys Vlasenko | 501e35c | 2010-03-22 13:43:12 +0100 | [diff] [blame] | 940 | bb_info_msg("Packet with bad magic, ignoring"); |
| 941 | return -2; |
| 942 | } |
Denys Vlasenko | 7981d79 | 2011-10-20 10:34:05 +0200 | [diff] [blame] | 943 | |
Denys Vlasenko | d38ca03 | 2011-11-05 01:25:03 +0100 | [diff] [blame] | 944 | log1("Received a packet"); |
Denys Vlasenko | 7981d79 | 2011-10-20 10:34:05 +0200 | [diff] [blame] | 945 | udhcp_dump_packet(&packet.data); |
| 946 | |
| 947 | bytes -= sizeof(packet.ip) + sizeof(packet.udp); |
| 948 | memcpy(dhcp_pkt, &packet.data, bytes); |
| 949 | return bytes; |
Denys Vlasenko | 501e35c | 2010-03-22 13:43:12 +0100 | [diff] [blame] | 950 | } |
Denys Vlasenko | 6b24d53 | 2010-03-22 13:42:13 +0100 | [diff] [blame] | 951 | |
Denys Vlasenko | dde8bdc | 2010-03-22 14:29:13 +0100 | [diff] [blame] | 952 | |
| 953 | /*** Main ***/ |
| 954 | |
| 955 | static int sockfd = -1; |
| 956 | |
| 957 | #define LISTEN_NONE 0 |
| 958 | #define LISTEN_KERNEL 1 |
| 959 | #define LISTEN_RAW 2 |
| 960 | static smallint listen_mode; |
| 961 | |
| 962 | /* initial state: (re)start DHCP negotiation */ |
| 963 | #define INIT_SELECTING 0 |
| 964 | /* discover was sent, DHCPOFFER reply received */ |
| 965 | #define REQUESTING 1 |
| 966 | /* select/renew was sent, DHCPACK reply received */ |
| 967 | #define BOUND 2 |
| 968 | /* half of lease passed, want to renew it by sending unicast renew requests */ |
| 969 | #define RENEWING 3 |
| 970 | /* renew requests were not answered, lease is almost over, send broadcast renew */ |
| 971 | #define REBINDING 4 |
| 972 | /* manually requested renew (SIGUSR1) */ |
| 973 | #define RENEW_REQUESTED 5 |
| 974 | /* release, possibly manually requested (SIGUSR2) */ |
| 975 | #define RELEASED 6 |
| 976 | static smallint state; |
| 977 | |
Denys Vlasenko | 6b24d53 | 2010-03-22 13:42:13 +0100 | [diff] [blame] | 978 | static int udhcp_raw_socket(int ifindex) |
| 979 | { |
| 980 | int fd; |
| 981 | struct sockaddr_ll sock; |
| 982 | |
Denys Vlasenko | 6b24d53 | 2010-03-22 13:42:13 +0100 | [diff] [blame] | 983 | log1("Opening raw socket on ifindex %d", ifindex); //log2? |
| 984 | |
| 985 | fd = xsocket(PF_PACKET, SOCK_DGRAM, htons(ETH_P_IP)); |
Denys Vlasenko | 744ee5d | 2014-02-07 17:38:52 +0100 | [diff] [blame] | 986 | /* ^^^^^ |
| 987 | * SOCK_DGRAM: remove link-layer headers on input (SOCK_RAW keeps them) |
| 988 | * ETH_P_IP: want to receive only packets with IPv4 eth type |
| 989 | */ |
Alexey Froloff | 3c62bba | 2012-09-17 16:02:44 +0200 | [diff] [blame] | 990 | log1("Got raw socket fd"); //log2? |
Denys Vlasenko | 6b24d53 | 2010-03-22 13:42:13 +0100 | [diff] [blame] | 991 | |
Vladislav Grishenko | 713e6d7 | 2011-02-14 04:50:30 +0100 | [diff] [blame] | 992 | sock.sll_family = AF_PACKET; |
| 993 | sock.sll_protocol = htons(ETH_P_IP); |
| 994 | sock.sll_ifindex = ifindex; |
| 995 | xbind(fd, (struct sockaddr *) &sock, sizeof(sock)); |
| 996 | |
Denys Vlasenko | e4785ca | 2014-02-03 18:03:42 +0100 | [diff] [blame] | 997 | #if 0 /* Several users reported breakage when BPF filter is used */ |
Vladislav Grishenko | 713e6d7 | 2011-02-14 04:50:30 +0100 | [diff] [blame] | 998 | if (CLIENT_PORT == 68) { |
| 999 | /* Use only if standard port is in use */ |
Denys Vlasenko | e4785ca | 2014-02-03 18:03:42 +0100 | [diff] [blame] | 1000 | /* |
| 1001 | * I've selected not to see LL header, so BPF doesn't see it, too. |
| 1002 | * The filter may also pass non-IP and non-ARP packets, but we do |
| 1003 | * a more complete check when receiving the message in userspace. |
| 1004 | * |
| 1005 | * and filter shamelessly stolen from: |
| 1006 | * |
| 1007 | * http://www.flamewarmaster.de/software/dhcpclient/ |
| 1008 | * |
| 1009 | * There are a few other interesting ideas on that page (look under |
| 1010 | * "Motivation"). Use of netlink events is most interesting. Think |
| 1011 | * of various network servers listening for events and reconfiguring. |
| 1012 | * That would obsolete sending HUP signals and/or make use of restarts. |
| 1013 | * |
| 1014 | * Copyright: 2006, 2007 Stefan Rompf <sux@loplof.de>. |
| 1015 | * License: GPL v2. |
Denys Vlasenko | e4785ca | 2014-02-03 18:03:42 +0100 | [diff] [blame] | 1016 | */ |
| 1017 | static const struct sock_filter filter_instr[] = { |
| 1018 | /* load 9th byte (protocol) */ |
| 1019 | BPF_STMT(BPF_LD|BPF_B|BPF_ABS, 9), |
| 1020 | /* jump to L1 if it is IPPROTO_UDP, else to L4 */ |
| 1021 | BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, IPPROTO_UDP, 0, 6), |
| 1022 | /* L1: load halfword from offset 6 (flags and frag offset) */ |
| 1023 | BPF_STMT(BPF_LD|BPF_H|BPF_ABS, 6), |
| 1024 | /* jump to L4 if any bits in frag offset field are set, else to L2 */ |
| 1025 | BPF_JUMP(BPF_JMP|BPF_JSET|BPF_K, 0x1fff, 4, 0), |
| 1026 | /* L2: skip IP header (load index reg with header len) */ |
| 1027 | BPF_STMT(BPF_LDX|BPF_B|BPF_MSH, 0), |
| 1028 | /* load udp destination port from halfword[header_len + 2] */ |
| 1029 | BPF_STMT(BPF_LD|BPF_H|BPF_IND, 2), |
| 1030 | /* jump to L3 if udp dport is CLIENT_PORT, else to L4 */ |
| 1031 | BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, 68, 0, 1), |
Denys Vlasenko | ffc3a93 | 2014-02-19 14:17:11 +0100 | [diff] [blame] | 1032 | /* L3: accept packet ("accept 0x7fffffff bytes") */ |
| 1033 | /* Accepting 0xffffffff works too but kernel 2.6.19 is buggy */ |
| 1034 | BPF_STMT(BPF_RET|BPF_K, 0x7fffffff), |
| 1035 | /* L4: discard packet ("accept zero bytes") */ |
Denys Vlasenko | e4785ca | 2014-02-03 18:03:42 +0100 | [diff] [blame] | 1036 | BPF_STMT(BPF_RET|BPF_K, 0), |
| 1037 | }; |
| 1038 | static const struct sock_fprog filter_prog = { |
| 1039 | .len = sizeof(filter_instr) / sizeof(filter_instr[0]), |
| 1040 | /* casting const away: */ |
| 1041 | .filter = (struct sock_filter *) filter_instr, |
| 1042 | }; |
Denys Vlasenko | 6b24d53 | 2010-03-22 13:42:13 +0100 | [diff] [blame] | 1043 | /* Ignoring error (kernel may lack support for this) */ |
| 1044 | if (setsockopt(fd, SOL_SOCKET, SO_ATTACH_FILTER, &filter_prog, |
| 1045 | sizeof(filter_prog)) >= 0) |
Alexey Froloff | 3c62bba | 2012-09-17 16:02:44 +0200 | [diff] [blame] | 1046 | log1("Attached filter to raw socket fd"); // log? |
| 1047 | } |
Denys Vlasenko | e4785ca | 2014-02-03 18:03:42 +0100 | [diff] [blame] | 1048 | #endif |
Alexey Froloff | 3c62bba | 2012-09-17 16:02:44 +0200 | [diff] [blame] | 1049 | |
| 1050 | if (setsockopt(fd, SOL_PACKET, PACKET_AUXDATA, |
| 1051 | &const_int_1, sizeof(int)) < 0 |
| 1052 | ) { |
| 1053 | if (errno != ENOPROTOOPT) |
| 1054 | log1("Can't set PACKET_AUXDATA on raw socket"); |
Denys Vlasenko | 6b24d53 | 2010-03-22 13:42:13 +0100 | [diff] [blame] | 1055 | } |
| 1056 | |
Denys Vlasenko | 6b24d53 | 2010-03-22 13:42:13 +0100 | [diff] [blame] | 1057 | log1("Created raw socket"); |
| 1058 | |
| 1059 | return fd; |
| 1060 | } |
| 1061 | |
Denis Vlasenko | 9cdfd14 | 2007-11-22 01:00:00 +0000 | [diff] [blame] | 1062 | static void change_listen_mode(int new_mode) |
Mike Frysinger | 7031f62 | 2006-05-08 03:20:50 +0000 | [diff] [blame] | 1063 | { |
Denys Vlasenko | 4945ed3 | 2009-06-17 11:58:11 +0200 | [diff] [blame] | 1064 | log1("Entering listen mode: %s", |
Denys Vlasenko | 13ca4b1 | 2009-07-19 04:07:21 +0200 | [diff] [blame] | 1065 | new_mode != LISTEN_NONE |
| 1066 | ? (new_mode == LISTEN_KERNEL ? "kernel" : "raw") |
| 1067 | : "none" |
| 1068 | ); |
Denis Vlasenko | 517413f | 2008-12-10 11:16:47 +0000 | [diff] [blame] | 1069 | |
| 1070 | listen_mode = new_mode; |
Denis Vlasenko | fbd2918 | 2007-04-07 01:05:47 +0000 | [diff] [blame] | 1071 | if (sockfd >= 0) { |
| 1072 | close(sockfd); |
| 1073 | sockfd = -1; |
| 1074 | } |
Denis Vlasenko | 517413f | 2008-12-10 11:16:47 +0000 | [diff] [blame] | 1075 | if (new_mode == LISTEN_KERNEL) |
| 1076 | sockfd = udhcp_listen_socket(/*INADDR_ANY,*/ CLIENT_PORT, client_config.interface); |
| 1077 | else if (new_mode != LISTEN_NONE) |
| 1078 | sockfd = udhcp_raw_socket(client_config.ifindex); |
Denys Vlasenko | 6b24d53 | 2010-03-22 13:42:13 +0100 | [diff] [blame] | 1079 | /* else LISTEN_NONE: sockfd stays closed */ |
Mike Frysinger | 7031f62 | 2006-05-08 03:20:50 +0000 | [diff] [blame] | 1080 | } |
| 1081 | |
Denys Vlasenko | 9ac5596 | 2011-03-12 05:37:54 +0100 | [diff] [blame] | 1082 | /* Called only on SIGUSR1 */ |
Mike Frysinger | 7031f62 | 2006-05-08 03:20:50 +0000 | [diff] [blame] | 1083 | static void perform_renew(void) |
| 1084 | { |
Denis Vlasenko | 3538b9a | 2006-09-06 18:36:50 +0000 | [diff] [blame] | 1085 | bb_info_msg("Performing a DHCP renew"); |
Mike Frysinger | 7031f62 | 2006-05-08 03:20:50 +0000 | [diff] [blame] | 1086 | switch (state) { |
| 1087 | case BOUND: |
Denis Vlasenko | 9cdfd14 | 2007-11-22 01:00:00 +0000 | [diff] [blame] | 1088 | change_listen_mode(LISTEN_KERNEL); |
Mike Frysinger | 7031f62 | 2006-05-08 03:20:50 +0000 | [diff] [blame] | 1089 | case RENEWING: |
| 1090 | case REBINDING: |
| 1091 | state = RENEW_REQUESTED; |
| 1092 | break; |
| 1093 | case RENEW_REQUESTED: /* impatient are we? fine, square 1 */ |
Rob Landley | 3f78561 | 2006-05-28 01:06:36 +0000 | [diff] [blame] | 1094 | udhcp_run_script(NULL, "deconfig"); |
Mike Frysinger | 7031f62 | 2006-05-08 03:20:50 +0000 | [diff] [blame] | 1095 | case REQUESTING: |
| 1096 | case RELEASED: |
Denis Vlasenko | 9cdfd14 | 2007-11-22 01:00:00 +0000 | [diff] [blame] | 1097 | change_listen_mode(LISTEN_RAW); |
Mike Frysinger | 7031f62 | 2006-05-08 03:20:50 +0000 | [diff] [blame] | 1098 | state = INIT_SELECTING; |
| 1099 | break; |
| 1100 | case INIT_SELECTING: |
| 1101 | break; |
| 1102 | } |
Mike Frysinger | 7031f62 | 2006-05-08 03:20:50 +0000 | [diff] [blame] | 1103 | } |
| 1104 | |
Denys Vlasenko | 0fd4347 | 2011-11-07 00:54:27 +0100 | [diff] [blame] | 1105 | static void perform_release(uint32_t server_addr, uint32_t requested_ip) |
Mike Frysinger | 7031f62 | 2006-05-08 03:20:50 +0000 | [diff] [blame] | 1106 | { |
Denis Vlasenko | 42b3dea | 2007-07-03 15:47:50 +0000 | [diff] [blame] | 1107 | char buffer[sizeof("255.255.255.255")]; |
Mike Frysinger | 7031f62 | 2006-05-08 03:20:50 +0000 | [diff] [blame] | 1108 | struct in_addr temp_addr; |
| 1109 | |
| 1110 | /* send release packet */ |
| 1111 | if (state == BOUND || state == RENEWING || state == REBINDING) { |
| 1112 | temp_addr.s_addr = server_addr; |
Denis Vlasenko | 42b3dea | 2007-07-03 15:47:50 +0000 | [diff] [blame] | 1113 | strcpy(buffer, inet_ntoa(temp_addr)); |
Mike Frysinger | 7031f62 | 2006-05-08 03:20:50 +0000 | [diff] [blame] | 1114 | temp_addr.s_addr = requested_ip; |
Denis Vlasenko | 3538b9a | 2006-09-06 18:36:50 +0000 | [diff] [blame] | 1115 | bb_info_msg("Unicasting a release of %s to %s", |
Mike Frysinger | 7031f62 | 2006-05-08 03:20:50 +0000 | [diff] [blame] | 1116 | inet_ntoa(temp_addr), buffer); |
| 1117 | send_release(server_addr, requested_ip); /* unicast */ |
Rob Landley | 3f78561 | 2006-05-28 01:06:36 +0000 | [diff] [blame] | 1118 | udhcp_run_script(NULL, "deconfig"); |
Mike Frysinger | 7031f62 | 2006-05-08 03:20:50 +0000 | [diff] [blame] | 1119 | } |
Denis Vlasenko | 3538b9a | 2006-09-06 18:36:50 +0000 | [diff] [blame] | 1120 | bb_info_msg("Entering released state"); |
Mike Frysinger | 7031f62 | 2006-05-08 03:20:50 +0000 | [diff] [blame] | 1121 | |
Denis Vlasenko | 9cdfd14 | 2007-11-22 01:00:00 +0000 | [diff] [blame] | 1122 | change_listen_mode(LISTEN_NONE); |
Mike Frysinger | 7031f62 | 2006-05-08 03:20:50 +0000 | [diff] [blame] | 1123 | state = RELEASED; |
Mike Frysinger | 7031f62 | 2006-05-08 03:20:50 +0000 | [diff] [blame] | 1124 | } |
| 1125 | |
Denis Vlasenko | e2d3ded | 2006-11-27 23:43:28 +0000 | [diff] [blame] | 1126 | static uint8_t* alloc_dhcp_option(int code, const char *str, int extra) |
| 1127 | { |
| 1128 | uint8_t *storage; |
Denys Vlasenko | 87fa216 | 2010-03-20 18:06:23 +0100 | [diff] [blame] | 1129 | int len = strnlen(str, 255); |
Denis Vlasenko | e2d3ded | 2006-11-27 23:43:28 +0000 | [diff] [blame] | 1130 | storage = xzalloc(len + extra + OPT_DATA); |
| 1131 | storage[OPT_CODE] = code; |
| 1132 | storage[OPT_LEN] = len + extra; |
| 1133 | memcpy(storage + extra + OPT_DATA, str, len); |
| 1134 | return storage; |
| 1135 | } |
| 1136 | |
Denys Vlasenko | dde8bdc | 2010-03-22 14:29:13 +0100 | [diff] [blame] | 1137 | #if BB_MMU |
| 1138 | static void client_background(void) |
| 1139 | { |
| 1140 | bb_daemonize(0); |
| 1141 | logmode &= ~LOGMODE_STDIO; |
| 1142 | /* rewrite pidfile, as our pid is different now */ |
| 1143 | write_pidfile(client_config.pidfile); |
| 1144 | } |
| 1145 | #endif |
| 1146 | |
Denys Vlasenko | 9e244c7 | 2010-10-20 01:38:56 +0200 | [diff] [blame] | 1147 | //usage:#if defined CONFIG_UDHCP_DEBUG && CONFIG_UDHCP_DEBUG >= 1 |
| 1148 | //usage:# define IF_UDHCP_VERBOSE(...) __VA_ARGS__ |
| 1149 | //usage:#else |
| 1150 | //usage:# define IF_UDHCP_VERBOSE(...) |
| 1151 | //usage:#endif |
| 1152 | //usage:#define udhcpc_trivial_usage |
Michel Stam | 9f41271 | 2014-10-30 11:59:04 +0100 | [diff] [blame^] | 1153 | //usage: "[-fbq"IF_UDHCP_VERBOSE("v")"RB]"IF_FEATURE_UDHCPC_ARPING(" [-a[MSEC]]")" [-t N] [-T SEC] [-A SEC/-n]\n" |
Denys Vlasenko | 9ae6d79 | 2013-08-08 12:45:45 +0200 | [diff] [blame] | 1154 | //usage: " [-i IFACE]"IF_FEATURE_UDHCP_PORT(" [-P PORT]")" [-s PROG] [-p PIDFILE]\n" |
| 1155 | //usage: " [-oC] [-r IP] [-V VENDOR] [-F NAME] [-x OPT:VAL]... [-O OPT]..." |
Denys Vlasenko | 9e244c7 | 2010-10-20 01:38:56 +0200 | [diff] [blame] | 1156 | //usage:#define udhcpc_full_usage "\n" |
| 1157 | //usage: IF_LONG_OPTS( |
| 1158 | //usage: "\n -i,--interface IFACE Interface to use (default eth0)" |
Denys Vlasenko | 9ae6d79 | 2013-08-08 12:45:45 +0200 | [diff] [blame] | 1159 | //usage: IF_FEATURE_UDHCP_PORT( |
| 1160 | //usage: "\n -P,--client-port PORT Use PORT (default 68)" |
| 1161 | //usage: ) |
Denys Vlasenko | 9e244c7 | 2010-10-20 01:38:56 +0200 | [diff] [blame] | 1162 | //usage: "\n -s,--script PROG Run PROG at DHCP events (default "CONFIG_UDHCPC_DEFAULT_SCRIPT")" |
Denys Vlasenko | 9ae6d79 | 2013-08-08 12:45:45 +0200 | [diff] [blame] | 1163 | //usage: "\n -p,--pidfile FILE Create pidfile" |
Keith Young | e6bb8d3 | 2011-03-07 03:18:46 +0100 | [diff] [blame] | 1164 | //usage: "\n -B,--broadcast Request broadcast replies" |
Denys Vlasenko | aadb485 | 2013-08-05 02:21:36 +0200 | [diff] [blame] | 1165 | //usage: "\n -t,--retries N Send up to N discover packets (default 3)" |
Denys Vlasenko | 456687f | 2013-08-08 12:33:18 +0200 | [diff] [blame] | 1166 | //usage: "\n -T,--timeout SEC Pause between packets (default 3)" |
Denys Vlasenko | 9ae6d79 | 2013-08-08 12:45:45 +0200 | [diff] [blame] | 1167 | //usage: "\n -A,--tryagain SEC Wait if lease is not obtained (default 20)" |
Denys Vlasenko | 456687f | 2013-08-08 12:33:18 +0200 | [diff] [blame] | 1168 | //usage: "\n -n,--now Exit if lease is not obtained" |
| 1169 | //usage: "\n -q,--quit Exit after obtaining lease" |
| 1170 | //usage: "\n -R,--release Release IP on exit" |
Denys Vlasenko | 9e244c7 | 2010-10-20 01:38:56 +0200 | [diff] [blame] | 1171 | //usage: "\n -f,--foreground Run in foreground" |
| 1172 | //usage: USE_FOR_MMU( |
| 1173 | //usage: "\n -b,--background Background if lease is not obtained" |
| 1174 | //usage: ) |
Denys Vlasenko | c59e06e | 2010-10-20 16:10:59 +0200 | [diff] [blame] | 1175 | //usage: "\n -S,--syslog Log to syslog too" |
Denys Vlasenko | 9e244c7 | 2010-10-20 01:38:56 +0200 | [diff] [blame] | 1176 | //usage: IF_FEATURE_UDHCPC_ARPING( |
Michel Stam | 9f41271 | 2014-10-30 11:59:04 +0100 | [diff] [blame^] | 1177 | //usage: "\n -a[MSEC],--arping[=MSEC] Validate offered address with ARP ping" |
Denys Vlasenko | 9e244c7 | 2010-10-20 01:38:56 +0200 | [diff] [blame] | 1178 | //usage: ) |
Denys Vlasenko | c59e06e | 2010-10-20 16:10:59 +0200 | [diff] [blame] | 1179 | //usage: "\n -r,--request IP Request this IP address" |
Denys Vlasenko | 9ae6d79 | 2013-08-08 12:45:45 +0200 | [diff] [blame] | 1180 | //usage: "\n -o,--no-default-options Don't request any options (unless -O is given)" |
| 1181 | //usage: "\n -O,--request-option OPT Request option OPT from server (cumulative)" |
Denys Vlasenko | 9e244c7 | 2010-10-20 01:38:56 +0200 | [diff] [blame] | 1182 | //usage: "\n -x OPT:VAL Include option OPT in sent packets (cumulative)" |
Denys Vlasenko | c59e06e | 2010-10-20 16:10:59 +0200 | [diff] [blame] | 1183 | //usage: "\n Examples of string, numeric, and hex byte opts:" |
| 1184 | //usage: "\n -x hostname:bbox - option 12" |
| 1185 | //usage: "\n -x lease:3600 - option 51 (lease time)" |
| 1186 | //usage: "\n -x 0x3d:0100BEEFC0FFEE - option 61 (client id)" |
Denys Vlasenko | 9e244c7 | 2010-10-20 01:38:56 +0200 | [diff] [blame] | 1187 | //usage: "\n -F,--fqdn NAME Ask server to update DNS mapping for NAME" |
Denys Vlasenko | 9e244c7 | 2010-10-20 01:38:56 +0200 | [diff] [blame] | 1188 | //usage: "\n -V,--vendorclass VENDOR Vendor identifier (default 'udhcp VERSION')" |
Denys Vlasenko | 1cbdc03 | 2010-10-20 01:42:37 +0200 | [diff] [blame] | 1189 | //usage: "\n -C,--clientid-none Don't send MAC as client identifier" |
Denys Vlasenko | 9e244c7 | 2010-10-20 01:38:56 +0200 | [diff] [blame] | 1190 | //usage: IF_UDHCP_VERBOSE( |
| 1191 | //usage: "\n -v Verbose" |
| 1192 | //usage: ) |
| 1193 | //usage: ) |
| 1194 | //usage: IF_NOT_LONG_OPTS( |
| 1195 | //usage: "\n -i IFACE Interface to use (default eth0)" |
Denys Vlasenko | 9ae6d79 | 2013-08-08 12:45:45 +0200 | [diff] [blame] | 1196 | //usage: IF_FEATURE_UDHCP_PORT( |
| 1197 | //usage: "\n -P PORT Use PORT (default 68)" |
| 1198 | //usage: ) |
Denys Vlasenko | 9e244c7 | 2010-10-20 01:38:56 +0200 | [diff] [blame] | 1199 | //usage: "\n -s PROG Run PROG at DHCP events (default "CONFIG_UDHCPC_DEFAULT_SCRIPT")" |
Denys Vlasenko | 9ae6d79 | 2013-08-08 12:45:45 +0200 | [diff] [blame] | 1200 | //usage: "\n -p FILE Create pidfile" |
Keith Young | e6bb8d3 | 2011-03-07 03:18:46 +0100 | [diff] [blame] | 1201 | //usage: "\n -B Request broadcast replies" |
Denys Vlasenko | aadb485 | 2013-08-05 02:21:36 +0200 | [diff] [blame] | 1202 | //usage: "\n -t N Send up to N discover packets (default 3)" |
Denys Vlasenko | 456687f | 2013-08-08 12:33:18 +0200 | [diff] [blame] | 1203 | //usage: "\n -T SEC Pause between packets (default 3)" |
Denys Vlasenko | 9ae6d79 | 2013-08-08 12:45:45 +0200 | [diff] [blame] | 1204 | //usage: "\n -A SEC Wait if lease is not obtained (default 20)" |
Denys Vlasenko | 456687f | 2013-08-08 12:33:18 +0200 | [diff] [blame] | 1205 | //usage: "\n -n Exit if lease is not obtained" |
| 1206 | //usage: "\n -q Exit after obtaining lease" |
| 1207 | //usage: "\n -R Release IP on exit" |
Denys Vlasenko | 9e244c7 | 2010-10-20 01:38:56 +0200 | [diff] [blame] | 1208 | //usage: "\n -f Run in foreground" |
| 1209 | //usage: USE_FOR_MMU( |
| 1210 | //usage: "\n -b Background if lease is not obtained" |
| 1211 | //usage: ) |
Denys Vlasenko | c59e06e | 2010-10-20 16:10:59 +0200 | [diff] [blame] | 1212 | //usage: "\n -S Log to syslog too" |
Denys Vlasenko | 9e244c7 | 2010-10-20 01:38:56 +0200 | [diff] [blame] | 1213 | //usage: IF_FEATURE_UDHCPC_ARPING( |
Michel Stam | 9f41271 | 2014-10-30 11:59:04 +0100 | [diff] [blame^] | 1214 | //usage: "\n -a[MSEC] Validate offered address with ARP ping" |
Denys Vlasenko | 9e244c7 | 2010-10-20 01:38:56 +0200 | [diff] [blame] | 1215 | //usage: ) |
Denys Vlasenko | c59e06e | 2010-10-20 16:10:59 +0200 | [diff] [blame] | 1216 | //usage: "\n -r IP Request this IP address" |
Denys Vlasenko | 9ae6d79 | 2013-08-08 12:45:45 +0200 | [diff] [blame] | 1217 | //usage: "\n -o Don't request any options (unless -O is given)" |
| 1218 | //usage: "\n -O OPT Request option OPT from server (cumulative)" |
Denys Vlasenko | c59e06e | 2010-10-20 16:10:59 +0200 | [diff] [blame] | 1219 | //usage: "\n -x OPT:VAL Include option OPT in sent packets (cumulative)" |
| 1220 | //usage: "\n Examples of string, numeric, and hex byte opts:" |
| 1221 | //usage: "\n -x hostname:bbox - option 12" |
| 1222 | //usage: "\n -x lease:3600 - option 51 (lease time)" |
| 1223 | //usage: "\n -x 0x3d:0100BEEFC0FFEE - option 61 (client id)" |
Denys Vlasenko | 9e244c7 | 2010-10-20 01:38:56 +0200 | [diff] [blame] | 1224 | //usage: "\n -F NAME Ask server to update DNS mapping for NAME" |
Denys Vlasenko | 9e244c7 | 2010-10-20 01:38:56 +0200 | [diff] [blame] | 1225 | //usage: "\n -V VENDOR Vendor identifier (default 'udhcp VERSION')" |
Denys Vlasenko | 1cbdc03 | 2010-10-20 01:42:37 +0200 | [diff] [blame] | 1226 | //usage: "\n -C Don't send MAC as client identifier" |
Denys Vlasenko | 9e244c7 | 2010-10-20 01:38:56 +0200 | [diff] [blame] | 1227 | //usage: IF_UDHCP_VERBOSE( |
| 1228 | //usage: "\n -v Verbose" |
| 1229 | //usage: ) |
| 1230 | //usage: ) |
Denys Vlasenko | 8993c3f | 2010-12-25 06:21:54 +0100 | [diff] [blame] | 1231 | //usage: "\nSignals:" |
Denys Vlasenko | 50089fc | 2011-11-07 15:44:46 +0100 | [diff] [blame] | 1232 | //usage: "\n USR1 Renew lease" |
| 1233 | //usage: "\n USR2 Release lease" |
Denys Vlasenko | 8993c3f | 2010-12-25 06:21:54 +0100 | [diff] [blame] | 1234 | |
Denys Vlasenko | 9e244c7 | 2010-10-20 01:38:56 +0200 | [diff] [blame] | 1235 | |
Denis Vlasenko | 9b49a5e | 2007-10-11 10:05:36 +0000 | [diff] [blame] | 1236 | int udhcpc_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
Denis Vlasenko | a60f84e | 2008-07-05 09:18:54 +0000 | [diff] [blame] | 1237 | int udhcpc_main(int argc UNUSED_PARAM, char **argv) |
Mike Frysinger | 7031f62 | 2006-05-08 03:20:50 +0000 | [diff] [blame] | 1238 | { |
Denys Vlasenko | e2318bb | 2014-02-27 18:15:50 +0100 | [diff] [blame] | 1239 | uint8_t *message; |
Denys Vlasenko | 1cbdc03 | 2010-10-20 01:42:37 +0200 | [diff] [blame] | 1240 | const char *str_V, *str_h, *str_F, *str_r; |
Michel Stam | 9f41271 | 2014-10-30 11:59:04 +0100 | [diff] [blame^] | 1241 | IF_FEATURE_UDHCPC_ARPING(const char *str_a = "2000";) |
Denis Vlasenko | 5e34ff2 | 2009-04-21 11:09:40 +0000 | [diff] [blame] | 1242 | IF_FEATURE_UDHCP_PORT(char *str_P;) |
Denys Vlasenko | 5d374e9 | 2010-10-20 22:26:38 +0200 | [diff] [blame] | 1243 | void *clientid_mac_ptr; |
Denis Vlasenko | 1918368 | 2007-12-10 07:03:38 +0000 | [diff] [blame] | 1244 | llist_t *list_O = NULL; |
Denys Vlasenko | 7e6add1 | 2010-03-25 20:32:38 +0100 | [diff] [blame] | 1245 | llist_t *list_x = NULL; |
Denis Vlasenko | 68af8e7 | 2007-11-22 21:41:14 +0000 | [diff] [blame] | 1246 | int tryagain_timeout = 20; |
| 1247 | int discover_timeout = 3; |
| 1248 | int discover_retries = 3; |
Denis Vlasenko | fc9e108 | 2008-05-26 17:32:35 +0000 | [diff] [blame] | 1249 | uint32_t server_addr = server_addr; /* for compiler */ |
| 1250 | uint32_t requested_ip = 0; |
Denys Vlasenko | 860491c | 2011-11-18 02:09:13 +0100 | [diff] [blame] | 1251 | uint32_t xid = xid; /* for compiler */ |
Denis Vlasenko | b539c84 | 2007-11-29 08:17:45 +0000 | [diff] [blame] | 1252 | int packet_num; |
Denis Vlasenko | fc9e108 | 2008-05-26 17:32:35 +0000 | [diff] [blame] | 1253 | int timeout; /* must be signed */ |
Denis Vlasenko | 19903f0 | 2008-05-21 07:03:03 +0000 | [diff] [blame] | 1254 | unsigned already_waited_sec; |
Denis Vlasenko | e2d3ded | 2006-11-27 23:43:28 +0000 | [diff] [blame] | 1255 | unsigned opt; |
Michel Stam | 9f41271 | 2014-10-30 11:59:04 +0100 | [diff] [blame^] | 1256 | IF_FEATURE_UDHCPC_ARPING(unsigned arpping_ms;) |
Mike Frysinger | 7031f62 | 2006-05-08 03:20:50 +0000 | [diff] [blame] | 1257 | int max_fd; |
Denis Vlasenko | e2d3ded | 2006-11-27 23:43:28 +0000 | [diff] [blame] | 1258 | int retval; |
Denis Vlasenko | 80edead | 2007-08-02 22:31:05 +0000 | [diff] [blame] | 1259 | fd_set rfds; |
Mike Frysinger | 7031f62 | 2006-05-08 03:20:50 +0000 | [diff] [blame] | 1260 | |
Denys Vlasenko | 5d374e9 | 2010-10-20 22:26:38 +0200 | [diff] [blame] | 1261 | /* Default options */ |
Denis Vlasenko | 5e34ff2 | 2009-04-21 11:09:40 +0000 | [diff] [blame] | 1262 | IF_FEATURE_UDHCP_PORT(SERVER_PORT = 67;) |
| 1263 | IF_FEATURE_UDHCP_PORT(CLIENT_PORT = 68;) |
Denis Vlasenko | e2d3ded | 2006-11-27 23:43:28 +0000 | [diff] [blame] | 1264 | client_config.interface = "eth0"; |
Denys Vlasenko | dde8bdc | 2010-03-22 14:29:13 +0100 | [diff] [blame] | 1265 | client_config.script = CONFIG_UDHCPC_DEFAULT_SCRIPT; |
Denys Vlasenko | 87fa216 | 2010-03-20 18:06:23 +0100 | [diff] [blame] | 1266 | str_V = "udhcp "BB_VER; |
Mike Frysinger | 7031f62 | 2006-05-08 03:20:50 +0000 | [diff] [blame] | 1267 | |
Denis Vlasenko | e2d3ded | 2006-11-27 23:43:28 +0000 | [diff] [blame] | 1268 | /* Parse command line */ |
Denys Vlasenko | 1cbdc03 | 2010-10-20 01:42:37 +0200 | [diff] [blame] | 1269 | /* O,x: list; -T,-t,-A take numeric param */ |
Leonid Lisovskiy | 6c9c0a1 | 2011-10-18 00:35:47 +0200 | [diff] [blame] | 1270 | opt_complementary = "O::x::T+:t+:A+" IF_UDHCP_VERBOSE(":vv") ; |
Denys Vlasenko | f3b92d3 | 2009-06-19 12:10:38 +0200 | [diff] [blame] | 1271 | IF_LONG_OPTS(applet_long_options = udhcpc_longopts;) |
Keith Young | e6bb8d3 | 2011-03-07 03:18:46 +0100 | [diff] [blame] | 1272 | opt = getopt32(argv, "CV:H:h:F:i:np:qRr:s:T:t:SA:O:ox:fB" |
Denis Vlasenko | 21765fa | 2008-06-13 20:44:05 +0000 | [diff] [blame] | 1273 | USE_FOR_MMU("b") |
Michel Stam | 9f41271 | 2014-10-30 11:59:04 +0100 | [diff] [blame^] | 1274 | IF_FEATURE_UDHCPC_ARPING("a::") |
Denis Vlasenko | 5e34ff2 | 2009-04-21 11:09:40 +0000 | [diff] [blame] | 1275 | IF_FEATURE_UDHCP_PORT("P:") |
Denys Vlasenko | ac906fa | 2009-06-17 11:54:52 +0200 | [diff] [blame] | 1276 | "v" |
Denys Vlasenko | 1cbdc03 | 2010-10-20 01:42:37 +0200 | [diff] [blame] | 1277 | , &str_V, &str_h, &str_h, &str_F |
Denis Vlasenko | 21765fa | 2008-06-13 20:44:05 +0000 | [diff] [blame] | 1278 | , &client_config.interface, &client_config.pidfile, &str_r /* i,p */ |
| 1279 | , &client_config.script /* s */ |
| 1280 | , &discover_timeout, &discover_retries, &tryagain_timeout /* T,t,A */ |
Denis Vlasenko | 1918368 | 2007-12-10 07:03:38 +0000 | [diff] [blame] | 1281 | , &list_O |
Denys Vlasenko | 7e6add1 | 2010-03-25 20:32:38 +0100 | [diff] [blame] | 1282 | , &list_x |
Michel Stam | 9f41271 | 2014-10-30 11:59:04 +0100 | [diff] [blame^] | 1283 | IF_FEATURE_UDHCPC_ARPING(, &str_a) |
Denis Vlasenko | 5e34ff2 | 2009-04-21 11:09:40 +0000 | [diff] [blame] | 1284 | IF_FEATURE_UDHCP_PORT(, &str_P) |
Leonid Lisovskiy | 6c9c0a1 | 2011-10-18 00:35:47 +0200 | [diff] [blame] | 1285 | IF_UDHCP_VERBOSE(, &dhcp_verbose) |
Denys Vlasenko | 7e21f04 | 2011-11-08 11:39:41 +0100 | [diff] [blame] | 1286 | ); |
Denys Vlasenko | 2017d48 | 2011-11-05 01:24:14 +0100 | [diff] [blame] | 1287 | if (opt & (OPT_h|OPT_H)) { |
| 1288 | //msg added 2011-11 |
| 1289 | bb_error_msg("option -h NAME is deprecated, use -x hostname:NAME"); |
Denis Vlasenko | e2d3ded | 2006-11-27 23:43:28 +0000 | [diff] [blame] | 1290 | client_config.hostname = alloc_dhcp_option(DHCP_HOST_NAME, str_h, 0); |
Denys Vlasenko | 2017d48 | 2011-11-05 01:24:14 +0100 | [diff] [blame] | 1291 | } |
Denis Vlasenko | e2d3ded | 2006-11-27 23:43:28 +0000 | [diff] [blame] | 1292 | if (opt & OPT_F) { |
Denys Vlasenko | 87fa216 | 2010-03-20 18:06:23 +0100 | [diff] [blame] | 1293 | /* FQDN option format: [0x51][len][flags][0][0]<fqdn> */ |
Denis Vlasenko | e2d3ded | 2006-11-27 23:43:28 +0000 | [diff] [blame] | 1294 | client_config.fqdn = alloc_dhcp_option(DHCP_FQDN, str_F, 3); |
Denys Vlasenko | 87fa216 | 2010-03-20 18:06:23 +0100 | [diff] [blame] | 1295 | /* Flag bits: 0000NEOS |
| 1296 | * S: 1 = Client requests server to update A RR in DNS as well as PTR |
| 1297 | * O: 1 = Server indicates to client that DNS has been updated regardless |
| 1298 | * E: 1 = Name is in DNS format, i.e. <4>host<6>domain<3>com<0>, |
| 1299 | * not "host.domain.com". Format 0 is obsolete. |
| 1300 | * N: 1 = Client requests server to not update DNS (S must be 0 then) |
| 1301 | * Two [0] bytes which follow are deprecated and must be 0. |
| 1302 | */ |
Denis Vlasenko | e2d3ded | 2006-11-27 23:43:28 +0000 | [diff] [blame] | 1303 | client_config.fqdn[OPT_DATA + 0] = 0x1; |
Denys Vlasenko | 87fa216 | 2010-03-20 18:06:23 +0100 | [diff] [blame] | 1304 | /*client_config.fqdn[OPT_DATA + 1] = 0; - xzalloc did it */ |
| 1305 | /*client_config.fqdn[OPT_DATA + 2] = 0; */ |
Denis Vlasenko | e2d3ded | 2006-11-27 23:43:28 +0000 | [diff] [blame] | 1306 | } |
Denis Vlasenko | e2d3ded | 2006-11-27 23:43:28 +0000 | [diff] [blame] | 1307 | if (opt & OPT_r) |
| 1308 | requested_ip = inet_addr(str_r); |
Denis Vlasenko | d55fe3e | 2008-02-04 13:12:16 +0000 | [diff] [blame] | 1309 | #if ENABLE_FEATURE_UDHCP_PORT |
| 1310 | if (opt & OPT_P) { |
| 1311 | CLIENT_PORT = xatou16(str_P); |
| 1312 | SERVER_PORT = CLIENT_PORT - 1; |
| 1313 | } |
| 1314 | #endif |
Michel Stam | 9f41271 | 2014-10-30 11:59:04 +0100 | [diff] [blame^] | 1315 | IF_FEATURE_UDHCPC_ARPING(arpping_ms = xatou(str_a);) |
Denis Vlasenko | 1918368 | 2007-12-10 07:03:38 +0000 | [diff] [blame] | 1316 | while (list_O) { |
Denis Vlasenko | 18c9302 | 2008-08-27 22:29:43 +0000 | [diff] [blame] | 1317 | char *optstr = llist_pop(&list_O); |
Denys Vlasenko | 5d3aace | 2011-06-04 05:07:16 +0200 | [diff] [blame] | 1318 | unsigned n = bb_strtou(optstr, NULL, 0); |
| 1319 | if (errno || n > 254) { |
| 1320 | n = udhcp_option_idx(optstr); |
| 1321 | n = dhcp_optflags[n].code; |
| 1322 | } |
Denis Vlasenko | 1918368 | 2007-12-10 07:03:38 +0000 | [diff] [blame] | 1323 | client_config.opt_mask[n >> 3] |= 1 << (n & 7); |
Denis Vlasenko | 1918368 | 2007-12-10 07:03:38 +0000 | [diff] [blame] | 1324 | } |
Denys Vlasenko | 293c945 | 2012-07-27 13:25:07 +0200 | [diff] [blame] | 1325 | if (!(opt & OPT_o)) { |
| 1326 | unsigned i, n; |
| 1327 | for (i = 0; (n = dhcp_optflags[i].code) != 0; i++) { |
| 1328 | if (dhcp_optflags[i].flags & OPTION_REQ) { |
| 1329 | client_config.opt_mask[n >> 3] |= 1 << (n & 7); |
| 1330 | } |
| 1331 | } |
| 1332 | } |
Denys Vlasenko | 7e6add1 | 2010-03-25 20:32:38 +0100 | [diff] [blame] | 1333 | while (list_x) { |
Denys Vlasenko | 7e6add1 | 2010-03-25 20:32:38 +0100 | [diff] [blame] | 1334 | char *optstr = llist_pop(&list_x); |
| 1335 | char *colon = strchr(optstr, ':'); |
| 1336 | if (colon) |
Denys Vlasenko | 7e6add1 | 2010-03-25 20:32:38 +0100 | [diff] [blame] | 1337 | *colon = ' '; |
Denys Vlasenko | 9c0ea86 | 2010-04-04 02:12:03 +0200 | [diff] [blame] | 1338 | /* now it looks similar to udhcpd's config file line: |
| 1339 | * "optname optval", using the common routine: */ |
Denys Vlasenko | 7e6add1 | 2010-03-25 20:32:38 +0100 | [diff] [blame] | 1340 | udhcp_str2optset(optstr, &client_config.options); |
| 1341 | } |
Mike Frysinger | 7031f62 | 2006-05-08 03:20:50 +0000 | [diff] [blame] | 1342 | |
Denys Vlasenko | 26918dd | 2009-06-16 12:04:23 +0200 | [diff] [blame] | 1343 | if (udhcp_read_interface(client_config.interface, |
| 1344 | &client_config.ifindex, |
| 1345 | NULL, |
| 1346 | client_config.client_mac) |
| 1347 | ) { |
Mike Frysinger | 7031f62 | 2006-05-08 03:20:50 +0000 | [diff] [blame] | 1348 | return 1; |
Denys Vlasenko | 26918dd | 2009-06-16 12:04:23 +0200 | [diff] [blame] | 1349 | } |
| 1350 | |
Denys Vlasenko | 5d374e9 | 2010-10-20 22:26:38 +0200 | [diff] [blame] | 1351 | clientid_mac_ptr = NULL; |
Denys Vlasenko | 1cbdc03 | 2010-10-20 01:42:37 +0200 | [diff] [blame] | 1352 | if (!(opt & OPT_C) && !udhcp_find_option(client_config.options, DHCP_CLIENT_ID)) { |
| 1353 | /* not suppressed and not set, set the default client ID */ |
Denys Vlasenko | 87fa216 | 2010-03-20 18:06:23 +0100 | [diff] [blame] | 1354 | client_config.clientid = alloc_dhcp_option(DHCP_CLIENT_ID, "", 7); |
| 1355 | client_config.clientid[OPT_DATA] = 1; /* type: ethernet */ |
Denys Vlasenko | 5d374e9 | 2010-10-20 22:26:38 +0200 | [diff] [blame] | 1356 | clientid_mac_ptr = client_config.clientid + OPT_DATA+1; |
| 1357 | memcpy(clientid_mac_ptr, client_config.client_mac, 6); |
Denys Vlasenko | 87fa216 | 2010-03-20 18:06:23 +0100 | [diff] [blame] | 1358 | } |
Denys Vlasenko | 2017d48 | 2011-11-05 01:24:14 +0100 | [diff] [blame] | 1359 | if (str_V[0] != '\0') { |
| 1360 | // can drop -V, str_V, client_config.vendorclass, |
| 1361 | // but need to add "vendor" to the list of recognized |
| 1362 | // string opts for this to work; |
| 1363 | // and need to tweak add_client_options() too... |
| 1364 | // ...so the question is, should we? |
| 1365 | //bb_error_msg("option -V VENDOR is deprecated, use -x vendor:VENDOR"); |
Denys Vlasenko | 87fa216 | 2010-03-20 18:06:23 +0100 | [diff] [blame] | 1366 | client_config.vendorclass = alloc_dhcp_option(DHCP_VENDOR, str_V, 0); |
Denys Vlasenko | 2017d48 | 2011-11-05 01:24:14 +0100 | [diff] [blame] | 1367 | } |
| 1368 | |
Denis Vlasenko | 21765fa | 2008-06-13 20:44:05 +0000 | [diff] [blame] | 1369 | #if !BB_MMU |
| 1370 | /* on NOMMU reexec (i.e., background) early */ |
| 1371 | if (!(opt & OPT_f)) { |
| 1372 | bb_daemonize_or_rexec(0 /* flags */, argv); |
Denis Vlasenko | a19e649 | 2009-03-11 14:40:00 +0000 | [diff] [blame] | 1373 | logmode = LOGMODE_NONE; |
Denis Vlasenko | 21765fa | 2008-06-13 20:44:05 +0000 | [diff] [blame] | 1374 | } |
| 1375 | #endif |
| 1376 | if (opt & OPT_S) { |
Denis Vlasenko | 5e4fda0 | 2009-03-08 23:46:48 +0000 | [diff] [blame] | 1377 | openlog(applet_name, LOG_PID, LOG_DAEMON); |
Denis Vlasenko | 21765fa | 2008-06-13 20:44:05 +0000 | [diff] [blame] | 1378 | logmode |= LOGMODE_SYSLOG; |
| 1379 | } |
Mike Frysinger | 7031f62 | 2006-05-08 03:20:50 +0000 | [diff] [blame] | 1380 | |
Denis Vlasenko | 80edead | 2007-08-02 22:31:05 +0000 | [diff] [blame] | 1381 | /* Make sure fd 0,1,2 are open */ |
| 1382 | bb_sanitize_stdio(); |
| 1383 | /* Equivalent of doing a fflush after every \n */ |
| 1384 | setlinebuf(stdout); |
Denis Vlasenko | 80edead | 2007-08-02 22:31:05 +0000 | [diff] [blame] | 1385 | /* Create pidfile */ |
| 1386 | write_pidfile(client_config.pidfile); |
Denis Vlasenko | 21765fa | 2008-06-13 20:44:05 +0000 | [diff] [blame] | 1387 | /* Goes to stdout (unless NOMMU) and possibly syslog */ |
Denis Vlasenko | def8898 | 2007-10-07 17:06:01 +0000 | [diff] [blame] | 1388 | bb_info_msg("%s (v"BB_VER") started", applet_name); |
Denys Vlasenko | 4248c33 | 2009-06-26 23:23:16 +0200 | [diff] [blame] | 1389 | /* Set up the signal pipe */ |
Mike Frysinger | 7031f62 | 2006-05-08 03:20:50 +0000 | [diff] [blame] | 1390 | udhcp_sp_setup(); |
Denys Vlasenko | 8d11445 | 2010-03-22 13:44:09 +0100 | [diff] [blame] | 1391 | /* We want random_xid to be random... */ |
| 1392 | srand(monotonic_us()); |
Mike Frysinger | 7031f62 | 2006-05-08 03:20:50 +0000 | [diff] [blame] | 1393 | |
| 1394 | state = INIT_SELECTING; |
Rob Landley | 3f78561 | 2006-05-28 01:06:36 +0000 | [diff] [blame] | 1395 | udhcp_run_script(NULL, "deconfig"); |
Denis Vlasenko | 9cdfd14 | 2007-11-22 01:00:00 +0000 | [diff] [blame] | 1396 | change_listen_mode(LISTEN_RAW); |
Denis Vlasenko | b539c84 | 2007-11-29 08:17:45 +0000 | [diff] [blame] | 1397 | packet_num = 0; |
Denis Vlasenko | fc9e108 | 2008-05-26 17:32:35 +0000 | [diff] [blame] | 1398 | timeout = 0; |
Denis Vlasenko | 19903f0 | 2008-05-21 07:03:03 +0000 | [diff] [blame] | 1399 | already_waited_sec = 0; |
Mike Frysinger | 7031f62 | 2006-05-08 03:20:50 +0000 | [diff] [blame] | 1400 | |
Denis Vlasenko | 9cdfd14 | 2007-11-22 01:00:00 +0000 | [diff] [blame] | 1401 | /* Main event loop. select() waits on signal pipe and possibly |
| 1402 | * on sockfd. |
| 1403 | * "continue" statements in code below jump to the top of the loop. |
| 1404 | */ |
Mike Frysinger | 7031f62 | 2006-05-08 03:20:50 +0000 | [diff] [blame] | 1405 | for (;;) { |
Denys Vlasenko | 0fd4347 | 2011-11-07 00:54:27 +0100 | [diff] [blame] | 1406 | struct timeval tv; |
| 1407 | struct dhcp_packet packet; |
Denis Vlasenko | ec64a57 | 2009-01-14 00:28:03 +0000 | [diff] [blame] | 1408 | /* silence "uninitialized!" warning */ |
| 1409 | unsigned timestamp_before_wait = timestamp_before_wait; |
Mike Frysinger | 7031f62 | 2006-05-08 03:20:50 +0000 | [diff] [blame] | 1410 | |
Denis Vlasenko | 517413f | 2008-12-10 11:16:47 +0000 | [diff] [blame] | 1411 | //bb_error_msg("sockfd:%d, listen_mode:%d", sockfd, listen_mode); |
| 1412 | |
| 1413 | /* Was opening raw or udp socket here |
| 1414 | * if (listen_mode != LISTEN_NONE && sockfd < 0), |
| 1415 | * but on fast network renew responses return faster |
| 1416 | * than we open sockets. Thus this code is moved |
| 1417 | * to change_listen_mode(). Thus we open listen socket |
| 1418 | * BEFORE we send renew request (see "case BOUND:"). */ |
| 1419 | |
Denis Vlasenko | fbd2918 | 2007-04-07 01:05:47 +0000 | [diff] [blame] | 1420 | max_fd = udhcp_sp_fd_set(&rfds, sockfd); |
Mike Frysinger | 7031f62 | 2006-05-08 03:20:50 +0000 | [diff] [blame] | 1421 | |
Denis Vlasenko | 19903f0 | 2008-05-21 07:03:03 +0000 | [diff] [blame] | 1422 | tv.tv_sec = timeout - already_waited_sec; |
Denis Vlasenko | b234291 | 2008-05-21 07:02:16 +0000 | [diff] [blame] | 1423 | tv.tv_usec = 0; |
Denys Vlasenko | 8d11445 | 2010-03-22 13:44:09 +0100 | [diff] [blame] | 1424 | retval = 0; |
| 1425 | /* If we already timed out, fall through with retval = 0, else... */ |
Denys Vlasenko | 13ca4b1 | 2009-07-19 04:07:21 +0200 | [diff] [blame] | 1426 | if ((int)tv.tv_sec > 0) { |
Denys Vlasenko | 085b293 | 2012-06-02 23:53:53 +0200 | [diff] [blame] | 1427 | log1("Waiting on select %u seconds", (int)tv.tv_sec); |
Denis Vlasenko | b234291 | 2008-05-21 07:02:16 +0000 | [diff] [blame] | 1428 | timestamp_before_wait = (unsigned)monotonic_sec(); |
Mike Frysinger | 7031f62 | 2006-05-08 03:20:50 +0000 | [diff] [blame] | 1429 | retval = select(max_fd + 1, &rfds, NULL, NULL, &tv); |
Denis Vlasenko | b234291 | 2008-05-21 07:02:16 +0000 | [diff] [blame] | 1430 | if (retval < 0) { |
| 1431 | /* EINTR? A signal was caught, don't panic */ |
Denys Vlasenko | 13ca4b1 | 2009-07-19 04:07:21 +0200 | [diff] [blame] | 1432 | if (errno == EINTR) { |
| 1433 | already_waited_sec += (unsigned)monotonic_sec() - timestamp_before_wait; |
Denis Vlasenko | b234291 | 2008-05-21 07:02:16 +0000 | [diff] [blame] | 1434 | continue; |
Denys Vlasenko | 13ca4b1 | 2009-07-19 04:07:21 +0200 | [diff] [blame] | 1435 | } |
Denis Vlasenko | 80edead | 2007-08-02 22:31:05 +0000 | [diff] [blame] | 1436 | /* Else: an error occured, panic! */ |
| 1437 | bb_perror_msg_and_die("select"); |
| 1438 | } |
Denis Vlasenko | 9cdfd14 | 2007-11-22 01:00:00 +0000 | [diff] [blame] | 1439 | } |
| 1440 | |
| 1441 | /* If timeout dropped to zero, time to become active: |
| 1442 | * resend discover/renew/whatever |
| 1443 | */ |
| 1444 | if (retval == 0) { |
Denys Vlasenko | a5048fa | 2010-10-20 21:38:29 +0200 | [diff] [blame] | 1445 | /* When running on a bridge, the ifindex may have changed |
| 1446 | * (e.g. if member interfaces were added/removed |
| 1447 | * or if the status of the bridge changed). |
| 1448 | * Refresh ifindex and client_mac: |
| 1449 | */ |
Denys Vlasenko | 5d374e9 | 2010-10-20 22:26:38 +0200 | [diff] [blame] | 1450 | if (udhcp_read_interface(client_config.interface, |
| 1451 | &client_config.ifindex, |
| 1452 | NULL, |
| 1453 | client_config.client_mac) |
| 1454 | ) { |
Denys Vlasenko | 0fd4347 | 2011-11-07 00:54:27 +0100 | [diff] [blame] | 1455 | goto ret0; /* iface is gone? */ |
Denys Vlasenko | 5d374e9 | 2010-10-20 22:26:38 +0200 | [diff] [blame] | 1456 | } |
| 1457 | if (clientid_mac_ptr) |
| 1458 | memcpy(clientid_mac_ptr, client_config.client_mac, 6); |
Denys Vlasenko | a5048fa | 2010-10-20 21:38:29 +0200 | [diff] [blame] | 1459 | |
Denis Vlasenko | f1980f6 | 2008-09-26 09:34:59 +0000 | [diff] [blame] | 1460 | /* We will restart the wait in any case */ |
Denis Vlasenko | 19903f0 | 2008-05-21 07:03:03 +0000 | [diff] [blame] | 1461 | already_waited_sec = 0; |
| 1462 | |
Mike Frysinger | 7031f62 | 2006-05-08 03:20:50 +0000 | [diff] [blame] | 1463 | switch (state) { |
| 1464 | case INIT_SELECTING: |
Felix Fietkau | 1c7a58d | 2012-09-27 16:22:24 +0200 | [diff] [blame] | 1465 | if (!discover_retries || packet_num < discover_retries) { |
Mike Frysinger | 7031f62 | 2006-05-08 03:20:50 +0000 | [diff] [blame] | 1466 | if (packet_num == 0) |
| 1467 | xid = random_xid(); |
Denys Vlasenko | 13ca4b1 | 2009-07-19 04:07:21 +0200 | [diff] [blame] | 1468 | /* broadcast */ |
| 1469 | send_discover(xid, requested_ip); |
Denis Vlasenko | 9cdfd14 | 2007-11-22 01:00:00 +0000 | [diff] [blame] | 1470 | timeout = discover_timeout; |
Mike Frysinger | 7031f62 | 2006-05-08 03:20:50 +0000 | [diff] [blame] | 1471 | packet_num++; |
Denis Vlasenko | 9cdfd14 | 2007-11-22 01:00:00 +0000 | [diff] [blame] | 1472 | continue; |
Mike Frysinger | 7031f62 | 2006-05-08 03:20:50 +0000 | [diff] [blame] | 1473 | } |
Denis Vlasenko | cdb0b65 | 2008-09-26 09:34:15 +0000 | [diff] [blame] | 1474 | leasefail: |
Denis Vlasenko | 9cdfd14 | 2007-11-22 01:00:00 +0000 | [diff] [blame] | 1475 | udhcp_run_script(NULL, "leasefail"); |
Denis Vlasenko | 21765fa | 2008-06-13 20:44:05 +0000 | [diff] [blame] | 1476 | #if BB_MMU /* -b is not supported on NOMMU */ |
| 1477 | if (opt & OPT_b) { /* background if no lease */ |
Denis Vlasenko | 9cdfd14 | 2007-11-22 01:00:00 +0000 | [diff] [blame] | 1478 | bb_info_msg("No lease, forking to background"); |
| 1479 | client_background(); |
Denis Vlasenko | 21765fa | 2008-06-13 20:44:05 +0000 | [diff] [blame] | 1480 | /* do not background again! */ |
| 1481 | opt = ((opt & ~OPT_b) | OPT_f); |
| 1482 | } else |
| 1483 | #endif |
| 1484 | if (opt & OPT_n) { /* abort if no lease */ |
Denis Vlasenko | 9cdfd14 | 2007-11-22 01:00:00 +0000 | [diff] [blame] | 1485 | bb_info_msg("No lease, failing"); |
| 1486 | retval = 1; |
| 1487 | goto ret; |
| 1488 | } |
Denis Vlasenko | 6de8994 | 2008-05-21 07:05:06 +0000 | [diff] [blame] | 1489 | /* wait before trying again */ |
Denis Vlasenko | 9cdfd14 | 2007-11-22 01:00:00 +0000 | [diff] [blame] | 1490 | timeout = tryagain_timeout; |
| 1491 | packet_num = 0; |
| 1492 | continue; |
Mike Frysinger | 7031f62 | 2006-05-08 03:20:50 +0000 | [diff] [blame] | 1493 | case REQUESTING: |
Felix Fietkau | 1c7a58d | 2012-09-27 16:22:24 +0200 | [diff] [blame] | 1494 | if (!discover_retries || packet_num < discover_retries) { |
Denys Vlasenko | 13ca4b1 | 2009-07-19 04:07:21 +0200 | [diff] [blame] | 1495 | /* send broadcast select packet */ |
| 1496 | send_select(xid, server_addr, requested_ip); |
Denis Vlasenko | 6de8994 | 2008-05-21 07:05:06 +0000 | [diff] [blame] | 1497 | timeout = discover_timeout; |
Mike Frysinger | 7031f62 | 2006-05-08 03:20:50 +0000 | [diff] [blame] | 1498 | packet_num++; |
Denis Vlasenko | 9cdfd14 | 2007-11-22 01:00:00 +0000 | [diff] [blame] | 1499 | continue; |
Mike Frysinger | 7031f62 | 2006-05-08 03:20:50 +0000 | [diff] [blame] | 1500 | } |
Denys Vlasenko | 13ca4b1 | 2009-07-19 04:07:21 +0200 | [diff] [blame] | 1501 | /* Timed out, go back to init state. |
| 1502 | * "discover...select...discover..." loops |
Denis Vlasenko | 7d9399e | 2008-09-26 22:21:03 +0000 | [diff] [blame] | 1503 | * were seen in the wild. Treat them similarly |
Denis Vlasenko | cdb0b65 | 2008-09-26 09:34:15 +0000 | [diff] [blame] | 1504 | * to "no response to discover" case */ |
Denys Vlasenko | 13ca4b1 | 2009-07-19 04:07:21 +0200 | [diff] [blame] | 1505 | change_listen_mode(LISTEN_RAW); |
Denis Vlasenko | 7d9399e | 2008-09-26 22:21:03 +0000 | [diff] [blame] | 1506 | state = INIT_SELECTING; |
Denys Vlasenko | 13ca4b1 | 2009-07-19 04:07:21 +0200 | [diff] [blame] | 1507 | goto leasefail; |
Mike Frysinger | 7031f62 | 2006-05-08 03:20:50 +0000 | [diff] [blame] | 1508 | case BOUND: |
Denys Vlasenko | 7d6a791 | 2009-07-19 04:24:23 +0200 | [diff] [blame] | 1509 | /* 1/2 lease passed, enter renewing state */ |
Denys Vlasenko | 13ca4b1 | 2009-07-19 04:07:21 +0200 | [diff] [blame] | 1510 | state = RENEWING; |
Denys Vlasenko | 9ac5596 | 2011-03-12 05:37:54 +0100 | [diff] [blame] | 1511 | client_config.first_secs = 0; /* make secs field count from 0 */ |
Denis Vlasenko | 9cdfd14 | 2007-11-22 01:00:00 +0000 | [diff] [blame] | 1512 | change_listen_mode(LISTEN_KERNEL); |
Denys Vlasenko | ac906fa | 2009-06-17 11:54:52 +0200 | [diff] [blame] | 1513 | log1("Entering renew state"); |
Mike Frysinger | 7031f62 | 2006-05-08 03:20:50 +0000 | [diff] [blame] | 1514 | /* fall right through */ |
Denys Vlasenko | 13ca4b1 | 2009-07-19 04:07:21 +0200 | [diff] [blame] | 1515 | case RENEW_REQUESTED: /* manual (SIGUSR1) renew */ |
| 1516 | case_RENEW_REQUESTED: |
Mike Frysinger | 7031f62 | 2006-05-08 03:20:50 +0000 | [diff] [blame] | 1517 | case RENEWING: |
Denis Vlasenko | 19903f0 | 2008-05-21 07:03:03 +0000 | [diff] [blame] | 1518 | if (timeout > 60) { |
Denys Vlasenko | 7d6a791 | 2009-07-19 04:24:23 +0200 | [diff] [blame] | 1519 | /* send an unicast renew request */ |
| 1520 | /* Sometimes observed to fail (EADDRNOTAVAIL) to bind |
| 1521 | * a new UDP socket for sending inside send_renew. |
| 1522 | * I hazard to guess existing listening socket |
| 1523 | * is somehow conflicting with it, but why is it |
| 1524 | * not deterministic then?! Strange. |
Denys Vlasenko | 753a3ce | 2009-07-19 04:27:10 +0200 | [diff] [blame] | 1525 | * Anyway, it does recover by eventually failing through |
Denys Vlasenko | 7d6a791 | 2009-07-19 04:24:23 +0200 | [diff] [blame] | 1526 | * into INIT_SELECTING state. |
| 1527 | */ |
Denys Vlasenko | 13ca4b1 | 2009-07-19 04:07:21 +0200 | [diff] [blame] | 1528 | send_renew(xid, server_addr, requested_ip); |
Denis Vlasenko | 19903f0 | 2008-05-21 07:03:03 +0000 | [diff] [blame] | 1529 | timeout >>= 1; |
Denis Vlasenko | 9cdfd14 | 2007-11-22 01:00:00 +0000 | [diff] [blame] | 1530 | continue; |
Mike Frysinger | 7031f62 | 2006-05-08 03:20:50 +0000 | [diff] [blame] | 1531 | } |
Denis Vlasenko | 9cdfd14 | 2007-11-22 01:00:00 +0000 | [diff] [blame] | 1532 | /* Timed out, enter rebinding state */ |
Denys Vlasenko | ac906fa | 2009-06-17 11:54:52 +0200 | [diff] [blame] | 1533 | log1("Entering rebinding state"); |
Denis Vlasenko | 9cdfd14 | 2007-11-22 01:00:00 +0000 | [diff] [blame] | 1534 | state = REBINDING; |
Denis Vlasenko | 6de8994 | 2008-05-21 07:05:06 +0000 | [diff] [blame] | 1535 | /* fall right through */ |
Mike Frysinger | 7031f62 | 2006-05-08 03:20:50 +0000 | [diff] [blame] | 1536 | case REBINDING: |
Denys Vlasenko | 219757f | 2009-10-08 23:05:46 +0200 | [diff] [blame] | 1537 | /* Switch to bcast receive */ |
| 1538 | change_listen_mode(LISTEN_RAW); |
Denis Vlasenko | 9cdfd14 | 2007-11-22 01:00:00 +0000 | [diff] [blame] | 1539 | /* Lease is *really* about to run out, |
| 1540 | * try to find DHCP server using broadcast */ |
Denis Vlasenko | 19903f0 | 2008-05-21 07:03:03 +0000 | [diff] [blame] | 1541 | if (timeout > 0) { |
Denys Vlasenko | 7d6a791 | 2009-07-19 04:24:23 +0200 | [diff] [blame] | 1542 | /* send a broadcast renew request */ |
Denys Vlasenko | 13ca4b1 | 2009-07-19 04:07:21 +0200 | [diff] [blame] | 1543 | send_renew(xid, 0 /*INADDR_ANY*/, requested_ip); |
Denis Vlasenko | 19903f0 | 2008-05-21 07:03:03 +0000 | [diff] [blame] | 1544 | timeout >>= 1; |
Denis Vlasenko | 9cdfd14 | 2007-11-22 01:00:00 +0000 | [diff] [blame] | 1545 | continue; |
Mike Frysinger | 7031f62 | 2006-05-08 03:20:50 +0000 | [diff] [blame] | 1546 | } |
Denis Vlasenko | 9cdfd14 | 2007-11-22 01:00:00 +0000 | [diff] [blame] | 1547 | /* Timed out, enter init state */ |
| 1548 | bb_info_msg("Lease lost, entering init state"); |
| 1549 | udhcp_run_script(NULL, "deconfig"); |
Denis Vlasenko | 9cdfd14 | 2007-11-22 01:00:00 +0000 | [diff] [blame] | 1550 | state = INIT_SELECTING; |
Denys Vlasenko | 9ac5596 | 2011-03-12 05:37:54 +0100 | [diff] [blame] | 1551 | client_config.first_secs = 0; /* make secs field count from 0 */ |
Denis Vlasenko | 19903f0 | 2008-05-21 07:03:03 +0000 | [diff] [blame] | 1552 | /*timeout = 0; - already is */ |
Denis Vlasenko | 9cdfd14 | 2007-11-22 01:00:00 +0000 | [diff] [blame] | 1553 | packet_num = 0; |
| 1554 | continue; |
| 1555 | /* case RELEASED: */ |
Mike Frysinger | 7031f62 | 2006-05-08 03:20:50 +0000 | [diff] [blame] | 1556 | } |
Denis Vlasenko | 9cdfd14 | 2007-11-22 01:00:00 +0000 | [diff] [blame] | 1557 | /* yah, I know, *you* say it would never happen */ |
| 1558 | timeout = INT_MAX; |
| 1559 | continue; /* back to main loop */ |
Denys Vlasenko | 4248c33 | 2009-06-26 23:23:16 +0200 | [diff] [blame] | 1560 | } /* if select timed out */ |
| 1561 | |
| 1562 | /* select() didn't timeout, something happened */ |
| 1563 | |
| 1564 | /* Is it a signal? */ |
| 1565 | /* note: udhcp_sp_read checks FD_ISSET before reading */ |
| 1566 | switch (udhcp_sp_read(&rfds)) { |
| 1567 | case SIGUSR1: |
Denys Vlasenko | 9ac5596 | 2011-03-12 05:37:54 +0100 | [diff] [blame] | 1568 | client_config.first_secs = 0; /* make secs field count from 0 */ |
Vladislav Grishenko | 6464f15 | 2011-10-18 01:37:47 +0200 | [diff] [blame] | 1569 | already_waited_sec = 0; |
Denys Vlasenko | 4248c33 | 2009-06-26 23:23:16 +0200 | [diff] [blame] | 1570 | perform_renew(); |
Vladislav Grishenko | 6464f15 | 2011-10-18 01:37:47 +0200 | [diff] [blame] | 1571 | if (state == RENEW_REQUESTED) { |
| 1572 | /* We might be either on the same network |
| 1573 | * (in which case renew might work), |
| 1574 | * or we might be on a completely different one |
| 1575 | * (in which case renew won't ever succeed). |
| 1576 | * For the second case, must make sure timeout |
| 1577 | * is not too big, or else we can send |
| 1578 | * futile renew requests for hours. |
| 1579 | * (Ab)use -A TIMEOUT value (usually 20 sec) |
| 1580 | * as a cap on the timeout. |
| 1581 | */ |
| 1582 | if (timeout > tryagain_timeout) |
| 1583 | timeout = tryagain_timeout; |
Denys Vlasenko | 13ca4b1 | 2009-07-19 04:07:21 +0200 | [diff] [blame] | 1584 | goto case_RENEW_REQUESTED; |
Vladislav Grishenko | 6464f15 | 2011-10-18 01:37:47 +0200 | [diff] [blame] | 1585 | } |
Denys Vlasenko | 4248c33 | 2009-06-26 23:23:16 +0200 | [diff] [blame] | 1586 | /* Start things over */ |
| 1587 | packet_num = 0; |
Denys Vlasenko | 7d6a791 | 2009-07-19 04:24:23 +0200 | [diff] [blame] | 1588 | /* Kill any timeouts, user wants this to hurry along */ |
Denys Vlasenko | 4248c33 | 2009-06-26 23:23:16 +0200 | [diff] [blame] | 1589 | timeout = 0; |
| 1590 | continue; |
| 1591 | case SIGUSR2: |
Denys Vlasenko | 0fd4347 | 2011-11-07 00:54:27 +0100 | [diff] [blame] | 1592 | perform_release(server_addr, requested_ip); |
Denys Vlasenko | 4248c33 | 2009-06-26 23:23:16 +0200 | [diff] [blame] | 1593 | timeout = INT_MAX; |
| 1594 | continue; |
| 1595 | case SIGTERM: |
| 1596 | bb_info_msg("Received SIGTERM"); |
Denys Vlasenko | 4248c33 | 2009-06-26 23:23:16 +0200 | [diff] [blame] | 1597 | goto ret0; |
Denis Vlasenko | 9cdfd14 | 2007-11-22 01:00:00 +0000 | [diff] [blame] | 1598 | } |
| 1599 | |
Denis Vlasenko | 739e30f | 2008-09-26 23:45:20 +0000 | [diff] [blame] | 1600 | /* Is it a packet? */ |
Denys Vlasenko | 4248c33 | 2009-06-26 23:23:16 +0200 | [diff] [blame] | 1601 | if (listen_mode == LISTEN_NONE || !FD_ISSET(sockfd, &rfds)) |
| 1602 | continue; /* no */ |
Mike Frysinger | 7031f62 | 2006-05-08 03:20:50 +0000 | [diff] [blame] | 1603 | |
Denys Vlasenko | 4248c33 | 2009-06-26 23:23:16 +0200 | [diff] [blame] | 1604 | { |
| 1605 | int len; |
| 1606 | |
| 1607 | /* A packet is ready, read it */ |
Mike Frysinger | 7031f62 | 2006-05-08 03:20:50 +0000 | [diff] [blame] | 1608 | if (listen_mode == LISTEN_KERNEL) |
Denis Vlasenko | 6de8994 | 2008-05-21 07:05:06 +0000 | [diff] [blame] | 1609 | len = udhcp_recv_kernel_packet(&packet, sockfd); |
Denis Vlasenko | b76b9a4 | 2008-01-25 22:46:34 +0000 | [diff] [blame] | 1610 | else |
Denis Vlasenko | 6de8994 | 2008-05-21 07:05:06 +0000 | [diff] [blame] | 1611 | len = udhcp_recv_raw_packet(&packet, sockfd); |
Denys Vlasenko | 4248c33 | 2009-06-26 23:23:16 +0200 | [diff] [blame] | 1612 | if (len == -1) { |
| 1613 | /* Error is severe, reopen socket */ |
Denys Vlasenko | ac906fa | 2009-06-17 11:54:52 +0200 | [diff] [blame] | 1614 | bb_info_msg("Read error: %s, reopening socket", strerror(errno)); |
Denis Vlasenko | 6de8994 | 2008-05-21 07:05:06 +0000 | [diff] [blame] | 1615 | sleep(discover_timeout); /* 3 seconds by default */ |
| 1616 | change_listen_mode(listen_mode); /* just close and reopen */ |
| 1617 | } |
Denis Vlasenko | b234291 | 2008-05-21 07:02:16 +0000 | [diff] [blame] | 1618 | /* If this packet will turn out to be unrelated/bogus, |
| 1619 | * we will go back and wait for next one. |
| 1620 | * Be sure timeout is properly decreased. */ |
Denis Vlasenko | 19903f0 | 2008-05-21 07:03:03 +0000 | [diff] [blame] | 1621 | already_waited_sec += (unsigned)monotonic_sec() - timestamp_before_wait; |
Denis Vlasenko | 6de8994 | 2008-05-21 07:05:06 +0000 | [diff] [blame] | 1622 | if (len < 0) |
| 1623 | continue; |
Denys Vlasenko | 4248c33 | 2009-06-26 23:23:16 +0200 | [diff] [blame] | 1624 | } |
Mike Frysinger | 7031f62 | 2006-05-08 03:20:50 +0000 | [diff] [blame] | 1625 | |
Denys Vlasenko | 4248c33 | 2009-06-26 23:23:16 +0200 | [diff] [blame] | 1626 | if (packet.xid != xid) { |
| 1627 | log1("xid %x (our is %x), ignoring packet", |
| 1628 | (unsigned)packet.xid, (unsigned)xid); |
| 1629 | continue; |
| 1630 | } |
Mike Frysinger | 7031f62 | 2006-05-08 03:20:50 +0000 | [diff] [blame] | 1631 | |
Denys Vlasenko | 4248c33 | 2009-06-26 23:23:16 +0200 | [diff] [blame] | 1632 | /* Ignore packets that aren't for us */ |
| 1633 | if (packet.hlen != 6 |
Denys Vlasenko | b3af65b | 2010-10-20 21:37:23 +0200 | [diff] [blame] | 1634 | || memcmp(packet.chaddr, client_config.client_mac, 6) != 0 |
Denys Vlasenko | 4248c33 | 2009-06-26 23:23:16 +0200 | [diff] [blame] | 1635 | ) { |
Denys Vlasenko | ac906fa | 2009-06-17 11:54:52 +0200 | [diff] [blame] | 1636 | //FIXME: need to also check that last 10 bytes are zero |
Denys Vlasenko | 4248c33 | 2009-06-26 23:23:16 +0200 | [diff] [blame] | 1637 | log1("chaddr does not match, ignoring packet"); // log2? |
| 1638 | continue; |
| 1639 | } |
Mike Frysinger | 7031f62 | 2006-05-08 03:20:50 +0000 | [diff] [blame] | 1640 | |
Denys Vlasenko | dde8bdc | 2010-03-22 14:29:13 +0100 | [diff] [blame] | 1641 | message = udhcp_get_option(&packet, DHCP_MESSAGE_TYPE); |
Denys Vlasenko | 4248c33 | 2009-06-26 23:23:16 +0200 | [diff] [blame] | 1642 | if (message == NULL) { |
| 1643 | bb_error_msg("no message type option, ignoring packet"); |
| 1644 | continue; |
| 1645 | } |
Mike Frysinger | 7031f62 | 2006-05-08 03:20:50 +0000 | [diff] [blame] | 1646 | |
Denys Vlasenko | 4248c33 | 2009-06-26 23:23:16 +0200 | [diff] [blame] | 1647 | switch (state) { |
| 1648 | case INIT_SELECTING: |
Denys Vlasenko | 860491c | 2011-11-18 02:09:13 +0100 | [diff] [blame] | 1649 | /* Must be a DHCPOFFER */ |
Denys Vlasenko | 4248c33 | 2009-06-26 23:23:16 +0200 | [diff] [blame] | 1650 | if (*message == DHCPOFFER) { |
Denys Vlasenko | e2318bb | 2014-02-27 18:15:50 +0100 | [diff] [blame] | 1651 | uint8_t *temp; |
| 1652 | |
Denys Vlasenko | 2af2acf | 2011-10-20 14:47:41 +0200 | [diff] [blame] | 1653 | /* What exactly is server's IP? There are several values. |
| 1654 | * Example DHCP offer captured with tchdump: |
| 1655 | * |
| 1656 | * 10.34.25.254:67 > 10.34.25.202:68 // IP header's src |
| 1657 | * BOOTP fields: |
| 1658 | * Your-IP 10.34.25.202 |
| 1659 | * Server-IP 10.34.32.125 // "next server" IP |
| 1660 | * Gateway-IP 10.34.25.254 // relay's address (if DHCP relays are in use) |
| 1661 | * DHCP options: |
| 1662 | * DHCP-Message Option 53, length 1: Offer |
| 1663 | * Server-ID Option 54, length 4: 10.34.255.7 // "server ID" |
| 1664 | * Default-Gateway Option 3, length 4: 10.34.25.254 // router |
| 1665 | * |
| 1666 | * We think that real server IP (one to use in renew/release) |
| 1667 | * is one in Server-ID option. But I am not 100% sure. |
Denys Vlasenko | ee320c6 | 2011-10-23 18:05:58 +0200 | [diff] [blame] | 1668 | * IP header's src and Gateway-IP (same in this example) |
Denys Vlasenko | 2af2acf | 2011-10-20 14:47:41 +0200 | [diff] [blame] | 1669 | * might work too. |
| 1670 | * "Next server" and router are definitely wrong ones to use, though... |
| 1671 | */ |
Denys Vlasenko | 8d3efaf | 2013-11-03 19:20:54 +0100 | [diff] [blame] | 1672 | /* We used to ignore pcakets without DHCP_SERVER_ID. |
| 1673 | * I've got user reports from people who run "address-less" servers. |
| 1674 | * They either supply DHCP_SERVER_ID of 0.0.0.0 or don't supply it at all. |
| 1675 | * They say ISC DHCP client supports this case. |
| 1676 | */ |
| 1677 | server_addr = 0; |
Denys Vlasenko | dde8bdc | 2010-03-22 14:29:13 +0100 | [diff] [blame] | 1678 | temp = udhcp_get_option(&packet, DHCP_SERVER_ID); |
Denys Vlasenko | 4248c33 | 2009-06-26 23:23:16 +0200 | [diff] [blame] | 1679 | if (!temp) { |
Denys Vlasenko | 8d3efaf | 2013-11-03 19:20:54 +0100 | [diff] [blame] | 1680 | bb_error_msg("no server ID, using 0.0.0.0"); |
| 1681 | } else { |
| 1682 | /* it IS unaligned sometimes, don't "optimize" */ |
| 1683 | move_from_unaligned32(server_addr, temp); |
Mike Frysinger | 7031f62 | 2006-05-08 03:20:50 +0000 | [diff] [blame] | 1684 | } |
Denys Vlasenko | b3af65b | 2010-10-20 21:37:23 +0200 | [diff] [blame] | 1685 | /*xid = packet.xid; - already is */ |
Denys Vlasenko | 4248c33 | 2009-06-26 23:23:16 +0200 | [diff] [blame] | 1686 | requested_ip = packet.yiaddr; |
| 1687 | |
| 1688 | /* enter requesting state */ |
| 1689 | state = REQUESTING; |
| 1690 | timeout = 0; |
| 1691 | packet_num = 0; |
| 1692 | already_waited_sec = 0; |
| 1693 | } |
| 1694 | continue; |
Denys Vlasenko | 4248c33 | 2009-06-26 23:23:16 +0200 | [diff] [blame] | 1695 | case REQUESTING: |
| 1696 | case RENEWING: |
Denys Vlasenko | 13ca4b1 | 2009-07-19 04:07:21 +0200 | [diff] [blame] | 1697 | case RENEW_REQUESTED: |
Denys Vlasenko | 4248c33 | 2009-06-26 23:23:16 +0200 | [diff] [blame] | 1698 | case REBINDING: |
| 1699 | if (*message == DHCPACK) { |
Denys Vlasenko | 0fd4347 | 2011-11-07 00:54:27 +0100 | [diff] [blame] | 1700 | uint32_t lease_seconds; |
| 1701 | struct in_addr temp_addr; |
Denys Vlasenko | e2318bb | 2014-02-27 18:15:50 +0100 | [diff] [blame] | 1702 | uint8_t *temp; |
Denys Vlasenko | 0fd4347 | 2011-11-07 00:54:27 +0100 | [diff] [blame] | 1703 | |
Denys Vlasenko | dde8bdc | 2010-03-22 14:29:13 +0100 | [diff] [blame] | 1704 | temp = udhcp_get_option(&packet, DHCP_LEASE_TIME); |
Denys Vlasenko | 4248c33 | 2009-06-26 23:23:16 +0200 | [diff] [blame] | 1705 | if (!temp) { |
| 1706 | bb_error_msg("no lease time with ACK, using 1 hour lease"); |
| 1707 | lease_seconds = 60 * 60; |
| 1708 | } else { |
| 1709 | /* it IS unaligned sometimes, don't "optimize" */ |
| 1710 | move_from_unaligned32(lease_seconds, temp); |
| 1711 | lease_seconds = ntohl(lease_seconds); |
Denys Vlasenko | 0fd4347 | 2011-11-07 00:54:27 +0100 | [diff] [blame] | 1712 | /* paranoia: must not be too small and not prone to overflows */ |
| 1713 | if (lease_seconds < 0x10) |
| 1714 | lease_seconds = 0x10; |
| 1715 | if (lease_seconds >= 0x10000000) |
| 1716 | lease_seconds = 0x0fffffff; |
Denys Vlasenko | 4248c33 | 2009-06-26 23:23:16 +0200 | [diff] [blame] | 1717 | } |
Denis Vlasenko | 223bc97 | 2007-11-22 00:58:49 +0000 | [diff] [blame] | 1718 | #if ENABLE_FEATURE_UDHCPC_ARPING |
Denys Vlasenko | 4248c33 | 2009-06-26 23:23:16 +0200 | [diff] [blame] | 1719 | if (opt & OPT_a) { |
Denis Vlasenko | 739e30f | 2008-09-26 23:45:20 +0000 | [diff] [blame] | 1720 | /* RFC 2131 3.1 paragraph 5: |
| 1721 | * "The client receives the DHCPACK message with configuration |
| 1722 | * parameters. The client SHOULD perform a final check on the |
| 1723 | * parameters (e.g., ARP for allocated network address), and notes |
| 1724 | * the duration of the lease specified in the DHCPACK message. At this |
| 1725 | * point, the client is configured. If the client detects that the |
| 1726 | * address is already in use (e.g., through the use of ARP), |
| 1727 | * the client MUST send a DHCPDECLINE message to the server and restarts |
| 1728 | * the configuration process..." */ |
Denys Vlasenko | 4248c33 | 2009-06-26 23:23:16 +0200 | [diff] [blame] | 1729 | if (!arpping(packet.yiaddr, |
| 1730 | NULL, |
| 1731 | (uint32_t) 0, |
| 1732 | client_config.client_mac, |
Michel Stam | 9f41271 | 2014-10-30 11:59:04 +0100 | [diff] [blame^] | 1733 | client_config.interface, |
| 1734 | arpping_ms) |
Denys Vlasenko | 4248c33 | 2009-06-26 23:23:16 +0200 | [diff] [blame] | 1735 | ) { |
| 1736 | bb_info_msg("Offered address is in use " |
| 1737 | "(got ARP reply), declining"); |
Denys Vlasenko | 860491c | 2011-11-18 02:09:13 +0100 | [diff] [blame] | 1738 | send_decline(/*xid,*/ server_addr, packet.yiaddr); |
Denis Vlasenko | 223bc97 | 2007-11-22 00:58:49 +0000 | [diff] [blame] | 1739 | |
Denys Vlasenko | 4248c33 | 2009-06-26 23:23:16 +0200 | [diff] [blame] | 1740 | if (state != REQUESTING) |
| 1741 | udhcp_run_script(NULL, "deconfig"); |
| 1742 | change_listen_mode(LISTEN_RAW); |
| 1743 | state = INIT_SELECTING; |
Denys Vlasenko | 9ac5596 | 2011-03-12 05:37:54 +0100 | [diff] [blame] | 1744 | client_config.first_secs = 0; /* make secs field count from 0 */ |
Denys Vlasenko | 4248c33 | 2009-06-26 23:23:16 +0200 | [diff] [blame] | 1745 | requested_ip = 0; |
| 1746 | timeout = tryagain_timeout; |
| 1747 | packet_num = 0; |
| 1748 | already_waited_sec = 0; |
| 1749 | continue; /* back to main loop */ |
Denis Vlasenko | 223bc97 | 2007-11-22 00:58:49 +0000 | [diff] [blame] | 1750 | } |
Denys Vlasenko | 4248c33 | 2009-06-26 23:23:16 +0200 | [diff] [blame] | 1751 | } |
Denis Vlasenko | 223bc97 | 2007-11-22 00:58:49 +0000 | [diff] [blame] | 1752 | #endif |
Denys Vlasenko | 4248c33 | 2009-06-26 23:23:16 +0200 | [diff] [blame] | 1753 | /* enter bound state */ |
| 1754 | timeout = lease_seconds / 2; |
Denys Vlasenko | 60cb48c | 2013-01-14 15:57:44 +0100 | [diff] [blame] | 1755 | temp_addr.s_addr = packet.yiaddr; |
Denys Vlasenko | 0fd4347 | 2011-11-07 00:54:27 +0100 | [diff] [blame] | 1756 | bb_info_msg("Lease of %s obtained, lease time %u", |
| 1757 | inet_ntoa(temp_addr), (unsigned)lease_seconds); |
Denys Vlasenko | 4248c33 | 2009-06-26 23:23:16 +0200 | [diff] [blame] | 1758 | requested_ip = packet.yiaddr; |
Denys Vlasenko | 4abfc26 | 2009-07-19 04:35:16 +0200 | [diff] [blame] | 1759 | udhcp_run_script(&packet, state == REQUESTING ? "bound" : "renew"); |
Mike Frysinger | 7031f62 | 2006-05-08 03:20:50 +0000 | [diff] [blame] | 1760 | |
Denys Vlasenko | 4248c33 | 2009-06-26 23:23:16 +0200 | [diff] [blame] | 1761 | state = BOUND; |
| 1762 | change_listen_mode(LISTEN_NONE); |
| 1763 | if (opt & OPT_q) { /* quit after lease */ |
Denys Vlasenko | 4248c33 | 2009-06-26 23:23:16 +0200 | [diff] [blame] | 1764 | goto ret0; |
| 1765 | } |
Justin Maggard | aa369e0 | 2009-08-13 01:26:17 +0200 | [diff] [blame] | 1766 | /* future renew failures should not exit (JM) */ |
| 1767 | opt &= ~OPT_n; |
Denis Vlasenko | 21765fa | 2008-06-13 20:44:05 +0000 | [diff] [blame] | 1768 | #if BB_MMU /* NOMMU case backgrounded earlier */ |
Denys Vlasenko | 4248c33 | 2009-06-26 23:23:16 +0200 | [diff] [blame] | 1769 | if (!(opt & OPT_f)) { |
| 1770 | client_background(); |
| 1771 | /* do not background again! */ |
| 1772 | opt = ((opt & ~OPT_b) | OPT_f); |
| 1773 | } |
Denis Vlasenko | 21765fa | 2008-06-13 20:44:05 +0000 | [diff] [blame] | 1774 | #endif |
Denys Vlasenko | 860491c | 2011-11-18 02:09:13 +0100 | [diff] [blame] | 1775 | /* make future renew packets use different xid */ |
| 1776 | /* xid = random_xid(); ...but why bother? */ |
Denys Vlasenko | 4248c33 | 2009-06-26 23:23:16 +0200 | [diff] [blame] | 1777 | already_waited_sec = 0; |
| 1778 | continue; /* back to main loop */ |
Mike Frysinger | 7031f62 | 2006-05-08 03:20:50 +0000 | [diff] [blame] | 1779 | } |
Denys Vlasenko | 4248c33 | 2009-06-26 23:23:16 +0200 | [diff] [blame] | 1780 | if (*message == DHCPNAK) { |
Denys Vlasenko | e2318bb | 2014-02-27 18:15:50 +0100 | [diff] [blame] | 1781 | /* If network has more than one DHCP server, |
| 1782 | * "wrong" server can reply first, with a NAK. |
| 1783 | * Do not interpret it as a NAK from "our" server. |
| 1784 | */ |
| 1785 | if (server_addr != 0) { |
| 1786 | uint32_t svid; |
| 1787 | uint8_t *temp; |
| 1788 | |
| 1789 | temp = udhcp_get_option(&packet, DHCP_SERVER_ID); |
| 1790 | if (!temp) { |
| 1791 | non_matching_svid: |
| 1792 | log1("%s with wrong server ID, ignoring packet", |
| 1793 | "Received DHCP NAK" |
| 1794 | ); |
| 1795 | continue; |
| 1796 | } |
| 1797 | move_from_unaligned32(svid, temp); |
| 1798 | if (svid != server_addr) |
| 1799 | goto non_matching_svid; |
| 1800 | } |
Denys Vlasenko | 4248c33 | 2009-06-26 23:23:16 +0200 | [diff] [blame] | 1801 | /* return to init state */ |
| 1802 | bb_info_msg("Received DHCP NAK"); |
| 1803 | udhcp_run_script(&packet, "nak"); |
| 1804 | if (state != REQUESTING) |
| 1805 | udhcp_run_script(NULL, "deconfig"); |
| 1806 | change_listen_mode(LISTEN_RAW); |
| 1807 | sleep(3); /* avoid excessive network traffic */ |
| 1808 | state = INIT_SELECTING; |
Denys Vlasenko | 9ac5596 | 2011-03-12 05:37:54 +0100 | [diff] [blame] | 1809 | client_config.first_secs = 0; /* make secs field count from 0 */ |
Denys Vlasenko | 4248c33 | 2009-06-26 23:23:16 +0200 | [diff] [blame] | 1810 | requested_ip = 0; |
Denis Vlasenko | b539c84 | 2007-11-29 08:17:45 +0000 | [diff] [blame] | 1811 | timeout = 0; |
Denys Vlasenko | 4248c33 | 2009-06-26 23:23:16 +0200 | [diff] [blame] | 1812 | packet_num = 0; |
| 1813 | already_waited_sec = 0; |
Mike Frysinger | 7031f62 | 2006-05-08 03:20:50 +0000 | [diff] [blame] | 1814 | } |
Denys Vlasenko | 4248c33 | 2009-06-26 23:23:16 +0200 | [diff] [blame] | 1815 | continue; |
| 1816 | /* case BOUND: - ignore all packets */ |
| 1817 | /* case RELEASED: - ignore all packets */ |
Mike Frysinger | 7031f62 | 2006-05-08 03:20:50 +0000 | [diff] [blame] | 1818 | } |
Denys Vlasenko | 4248c33 | 2009-06-26 23:23:16 +0200 | [diff] [blame] | 1819 | /* back to main loop */ |
Denis Vlasenko | 9cdfd14 | 2007-11-22 01:00:00 +0000 | [diff] [blame] | 1820 | } /* for (;;) - main loop ends */ |
| 1821 | |
Denis Vlasenko | 6e6d331 | 2007-05-03 23:39:35 +0000 | [diff] [blame] | 1822 | ret0: |
Denys Vlasenko | 0fd4347 | 2011-11-07 00:54:27 +0100 | [diff] [blame] | 1823 | if (opt & OPT_R) /* release on quit */ |
| 1824 | perform_release(server_addr, requested_ip); |
Denis Vlasenko | 6e6d331 | 2007-05-03 23:39:35 +0000 | [diff] [blame] | 1825 | retval = 0; |
| 1826 | ret: |
Denis Vlasenko | b234291 | 2008-05-21 07:02:16 +0000 | [diff] [blame] | 1827 | /*if (client_config.pidfile) - remove_pidfile has its own check */ |
Denis Vlasenko | 6e6d331 | 2007-05-03 23:39:35 +0000 | [diff] [blame] | 1828 | remove_pidfile(client_config.pidfile); |
| 1829 | return retval; |
Mike Frysinger | 7031f62 | 2006-05-08 03:20:50 +0000 | [diff] [blame] | 1830 | } |