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"Robert P. J. Day"63fc1a92006-07-02 19:47:05 +00001/* vi: set sw=4 ts=4: */
Mike Frysinger7031f622006-05-08 03:20:50 +00002/* script.c
3 *
4 * Functions to call the DHCP client notification scripts
5 *
6 * Russ Dill <Russ.Dill@asu.edu> July 2001
7 *
Rob Landley3f785612006-05-28 01:06:36 +00008 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
Mike Frysinger7031f622006-05-08 03:20:50 +00009 */
10
Mike Frysinger7031f622006-05-08 03:20:50 +000011#include "common.h"
Mike Frysinger7031f622006-05-08 03:20:50 +000012#include "dhcpc.h"
Denis Vlasenko5a3395b2006-11-18 19:51:32 +000013#include "options.h"
14
Mike Frysinger7031f622006-05-08 03:20:50 +000015
16/* get a rough idea of how long an option will be (rounding up...) */
Denis Vlasenko3f112312007-08-19 21:21:16 +000017static const uint8_t max_option_length[] = {
Mike Frysinger7031f622006-05-08 03:20:50 +000018 [OPTION_IP] = sizeof("255.255.255.255 "),
19 [OPTION_IP_PAIR] = sizeof("255.255.255.255 ") * 2,
20 [OPTION_STRING] = 1,
Denis Vlasenko50664732007-02-27 21:15:08 +000021#if ENABLE_FEATURE_RFC3397
22 [OPTION_STR1035] = 1,
23#endif
Mike Frysinger7031f622006-05-08 03:20:50 +000024 [OPTION_BOOLEAN] = sizeof("yes "),
25 [OPTION_U8] = sizeof("255 "),
26 [OPTION_U16] = sizeof("65535 "),
27 [OPTION_S16] = sizeof("-32768 "),
28 [OPTION_U32] = sizeof("4294967295 "),
29 [OPTION_S32] = sizeof("-2147483684 "),
30};
31
32
33static inline int upper_length(int length, int opt_index)
34{
35 return max_option_length[opt_index] *
Denis Vlasenkob539c842007-11-29 08:17:45 +000036 (length / dhcp_option_lengths[opt_index]);
Mike Frysinger7031f622006-05-08 03:20:50 +000037}
38
39
Denis Vlasenkob6aae0f2007-01-29 22:51:25 +000040static int sprintip(char *dest, const char *pre, const uint8_t *ip)
Mike Frysinger7031f622006-05-08 03:20:50 +000041{
42 return sprintf(dest, "%s%d.%d.%d.%d", pre, ip[0], ip[1], ip[2], ip[3]);
43}
44
45
46/* really simple implementation, just count the bits */
Denis Vlasenko35ff7462007-11-28 19:23:12 +000047static int mton(uint32_t mask)
Mike Frysinger7031f622006-05-08 03:20:50 +000048{
Denis Vlasenko35ff7462007-11-28 19:23:12 +000049 int i = 0;
50 mask = ntohl(mask); /* 111110000-like bit pattern */
51 while (mask) {
52 i++;
53 mask <<= 1;
54 }
55 return i;
Mike Frysinger7031f622006-05-08 03:20:50 +000056}
57
58
Denis Vlasenko50664732007-02-27 21:15:08 +000059/* Allocate and fill with the text of option 'option'. */
Denis Vlasenkob539c842007-11-29 08:17:45 +000060static char *alloc_fill_opts(uint8_t *option, const struct dhcp_option *type_p, const char *opt_name)
Mike Frysinger7031f622006-05-08 03:20:50 +000061{
Denis Vlasenko50664732007-02-27 21:15:08 +000062 int len, type, optlen;
Mike Frysinger7031f622006-05-08 03:20:50 +000063 uint16_t val_u16;
64 int16_t val_s16;
65 uint32_t val_u32;
66 int32_t val_s32;
Denis Vlasenko50664732007-02-27 21:15:08 +000067 char *dest, *ret;
Mike Frysinger7031f622006-05-08 03:20:50 +000068
Denis Vlasenko50664732007-02-27 21:15:08 +000069 len = option[OPT_LEN - 2];
Mike Frysinger7031f622006-05-08 03:20:50 +000070 type = type_p->flags & TYPE_MASK;
Denis Vlasenkob539c842007-11-29 08:17:45 +000071 optlen = dhcp_option_lengths[type];
Denis Vlasenko50664732007-02-27 21:15:08 +000072
Denis Vlasenkob539c842007-11-29 08:17:45 +000073 dest = ret = xmalloc(upper_length(len, type) + strlen(opt_name) + 2);
74 dest += sprintf(ret, "%s=", opt_name);
Denis Vlasenko50664732007-02-27 21:15:08 +000075
Denis Vlasenko5a3395b2006-11-18 19:51:32 +000076 for (;;) {
Mike Frysinger7031f622006-05-08 03:20:50 +000077 switch (type) {
78 case OPTION_IP_PAIR:
79 dest += sprintip(dest, "", option);
Denis Vlasenkofbd29182007-04-07 01:05:47 +000080 *dest++ = '/';
Mike Frysinger7031f622006-05-08 03:20:50 +000081 option += 4;
82 optlen = 4;
83 case OPTION_IP: /* Works regardless of host byte order. */
84 dest += sprintip(dest, "", option);
85 break;
86 case OPTION_BOOLEAN:
87 dest += sprintf(dest, *option ? "yes" : "no");
88 break;
89 case OPTION_U8:
90 dest += sprintf(dest, "%u", *option);
91 break;
92 case OPTION_U16:
93 memcpy(&val_u16, option, 2);
94 dest += sprintf(dest, "%u", ntohs(val_u16));
95 break;
96 case OPTION_S16:
97 memcpy(&val_s16, option, 2);
98 dest += sprintf(dest, "%d", ntohs(val_s16));
99 break;
100 case OPTION_U32:
101 memcpy(&val_u32, option, 4);
102 dest += sprintf(dest, "%lu", (unsigned long) ntohl(val_u32));
103 break;
104 case OPTION_S32:
105 memcpy(&val_s32, option, 4);
106 dest += sprintf(dest, "%ld", (long) ntohl(val_s32));
107 break;
108 case OPTION_STRING:
109 memcpy(dest, option, len);
110 dest[len] = '\0';
Denis Vlasenko50664732007-02-27 21:15:08 +0000111 return ret; /* Short circuit this case */
112#if ENABLE_FEATURE_RFC3397
113 case OPTION_STR1035:
114 /* unpack option into dest; use ret for prefix (i.e., "optname=") */
115 dest = dname_dec(option, len, ret);
116 free(ret);
117 return dest;
118#endif
Mike Frysinger7031f622006-05-08 03:20:50 +0000119 }
120 option += optlen;
121 len -= optlen;
122 if (len <= 0) break;
123 dest += sprintf(dest, " ");
124 }
Denis Vlasenko50664732007-02-27 21:15:08 +0000125 return ret;
Mike Frysinger7031f622006-05-08 03:20:50 +0000126}
127
128
129/* put all the parameters into an environment */
130static char **fill_envp(struct dhcpMessage *packet)
131{
132 int num_options = 0;
133 int i, j;
134 char **envp;
Denis Vlasenkofbd29182007-04-07 01:05:47 +0000135 char *var;
Denis Vlasenkob539c842007-11-29 08:17:45 +0000136 const char *opt_name;
Mike Frysinger7031f622006-05-08 03:20:50 +0000137 uint8_t *temp;
Mike Frysinger7031f622006-05-08 03:20:50 +0000138 char over = 0;
139
Denis Vlasenkofbd29182007-04-07 01:05:47 +0000140 if (packet) {
141 for (i = 0; dhcp_options[i].code; i++) {
Mike Frysinger7031f622006-05-08 03:20:50 +0000142 if (get_option(packet, dhcp_options[i].code)) {
143 num_options++;
144 if (dhcp_options[i].code == DHCP_SUBNET)
145 num_options++; /* for mton */
146 }
Denis Vlasenkofbd29182007-04-07 01:05:47 +0000147 }
148 if (packet->siaddr)
149 num_options++;
150 temp = get_option(packet, DHCP_OPTION_OVER);
151 if (temp)
Mike Frysinger7031f622006-05-08 03:20:50 +0000152 over = *temp;
Denis Vlasenkofbd29182007-04-07 01:05:47 +0000153 if (!(over & FILE_FIELD) && packet->file[0])
154 num_options++;
155 if (!(over & SNAME_FIELD) && packet->sname[0])
156 num_options++;
Mike Frysinger7031f622006-05-08 03:20:50 +0000157 }
158
Rob Landley9ffd4232006-05-21 18:30:35 +0000159 envp = xzalloc(sizeof(char *) * (num_options + 5));
Mike Frysinger7031f622006-05-08 03:20:50 +0000160 j = 0;
Rob Landleyd921b2e2006-08-03 15:41:12 +0000161 envp[j++] = xasprintf("interface=%s", client_config.interface);
Denis Vlasenkofbd29182007-04-07 01:05:47 +0000162 var = getenv("PATH");
163 if (var)
164 envp[j++] = xasprintf("PATH=%s", var);
165 var = getenv("HOME");
166 if (var)
167 envp[j++] = xasprintf("HOME=%s", var);
Mike Frysinger7031f622006-05-08 03:20:50 +0000168
Denis Vlasenkofbd29182007-04-07 01:05:47 +0000169 if (packet == NULL)
170 return envp;
Mike Frysinger7031f622006-05-08 03:20:50 +0000171
172 envp[j] = xmalloc(sizeof("ip=255.255.255.255"));
173 sprintip(envp[j++], "ip=", (uint8_t *) &packet->yiaddr);
174
Denis Vlasenkob539c842007-11-29 08:17:45 +0000175 opt_name = dhcp_option_strings;
176 i = 0;
177 while (*opt_name) {
Denis Vlasenkoc90c3f32006-11-23 12:57:49 +0000178 temp = get_option(packet, dhcp_options[i].code);
Denis Vlasenkoc2f5b022006-11-28 00:21:46 +0000179 if (!temp)
Denis Vlasenkob539c842007-11-29 08:17:45 +0000180 goto next;
181 envp[j++] = alloc_fill_opts(temp, &dhcp_options[i], opt_name);
Mike Frysinger7031f622006-05-08 03:20:50 +0000182
183 /* Fill in a subnet bits option for things like /24 */
184 if (dhcp_options[i].code == DHCP_SUBNET) {
Denis Vlasenko35ff7462007-11-28 19:23:12 +0000185 uint32_t subnet;
Mike Frysinger7031f622006-05-08 03:20:50 +0000186 memcpy(&subnet, temp, 4);
Denis Vlasenko35ff7462007-11-28 19:23:12 +0000187 envp[j++] = xasprintf("mask=%d", mton(subnet));
Mike Frysinger7031f622006-05-08 03:20:50 +0000188 }
Denis Vlasenkob539c842007-11-29 08:17:45 +0000189 next:
190 opt_name += strlen(opt_name) + 1;
191 i++;
Mike Frysinger7031f622006-05-08 03:20:50 +0000192 }
193 if (packet->siaddr) {
194 envp[j] = xmalloc(sizeof("siaddr=255.255.255.255"));
195 sprintip(envp[j++], "siaddr=", (uint8_t *) &packet->siaddr);
196 }
197 if (!(over & FILE_FIELD) && packet->file[0]) {
198 /* watch out for invalid packets */
199 packet->file[sizeof(packet->file) - 1] = '\0';
Rob Landleyd921b2e2006-08-03 15:41:12 +0000200 envp[j++] = xasprintf("boot_file=%s", packet->file);
Mike Frysinger7031f622006-05-08 03:20:50 +0000201 }
202 if (!(over & SNAME_FIELD) && packet->sname[0]) {
203 /* watch out for invalid packets */
204 packet->sname[sizeof(packet->sname) - 1] = '\0';
Rob Landleyd921b2e2006-08-03 15:41:12 +0000205 envp[j++] = xasprintf("sname=%s", packet->sname);
Mike Frysinger7031f622006-05-08 03:20:50 +0000206 }
207 return envp;
208}
209
210
211/* Call a script with a par file and env vars */
Rob Landley3f785612006-05-28 01:06:36 +0000212void udhcp_run_script(struct dhcpMessage *packet, const char *name)
Mike Frysinger7031f622006-05-08 03:20:50 +0000213{
214 int pid;
215 char **envp, **curr;
216
217 if (client_config.script == NULL)
218 return;
219
Denis Vlasenko3538b9a2006-09-06 18:36:50 +0000220 DEBUG("vfork'ing and execle'ing %s", client_config.script);
Mike Frysinger7031f622006-05-08 03:20:50 +0000221
222 envp = fill_envp(packet);
Denis Vlasenkofbd29182007-04-07 01:05:47 +0000223
Mike Frysinger7031f622006-05-08 03:20:50 +0000224 /* call script */
Denis Vlasenkofbd29182007-04-07 01:05:47 +0000225// can we use wait4pid(spawn(...)) here?
Mike Frysinger7031f622006-05-08 03:20:50 +0000226 pid = vfork();
Denis Vlasenkofbd29182007-04-07 01:05:47 +0000227 if (pid < 0) return;
228 if (pid == 0) {
Mike Frysinger7031f622006-05-08 03:20:50 +0000229 /* close fd's? */
Mike Frysinger7031f622006-05-08 03:20:50 +0000230 /* exec script */
231 execle(client_config.script, client_config.script,
232 name, NULL, envp);
Denis Vlasenkofbd29182007-04-07 01:05:47 +0000233 bb_perror_msg_and_die("script %s failed", client_config.script);
Mike Frysinger7031f622006-05-08 03:20:50 +0000234 }
Denis Vlasenkofb0eba72008-01-02 19:55:04 +0000235 safe_waitpid(pid, NULL, 0);
Denis Vlasenkofbd29182007-04-07 01:05:47 +0000236 for (curr = envp; *curr; curr++)
237 free(*curr);
238 free(envp);
Mike Frysinger7031f622006-05-08 03:20:50 +0000239}