| /* vi: set sw=4 ts=4: */ |
| /* |
| * Mini ipcalc implementation for busybox |
| * |
| * By Jordan Crouse <jordan@cosmicpenguin.net> |
| * Stephan Linz <linz@li-pro.net> |
| * |
| * This is a complete reimplementation of the ipcalc program |
| * from Red Hat. I didn't look at their source code, but there |
| * is no denying that this is a loving reimplementation |
| * |
| * Licensed under GPLv2 or later, see file LICENSE in this source tree. |
| */ |
| |
| //usage:#define ipcalc_trivial_usage |
| //usage: "[OPTIONS] ADDRESS" |
| //usage: IF_FEATURE_IPCALC_FANCY("[/PREFIX]") " [NETMASK]" |
| //usage:#define ipcalc_full_usage "\n\n" |
| //usage: "Calculate IP network settings from a IP address\n" |
| //usage: IF_FEATURE_IPCALC_LONG_OPTIONS( |
| //usage: "\n -b,--broadcast Display calculated broadcast address" |
| //usage: "\n -n,--network Display calculated network address" |
| //usage: "\n -m,--netmask Display default netmask for IP" |
| //usage: IF_FEATURE_IPCALC_FANCY( |
| //usage: "\n -p,--prefix Display the prefix for IP/NETMASK" |
| //usage: "\n -h,--hostname Display first resolved host name" |
| //usage: "\n -s,--silent Don't ever display error messages" |
| //usage: ) |
| //usage: ) |
| //usage: IF_NOT_FEATURE_IPCALC_LONG_OPTIONS( |
| //usage: "\n -b Display calculated broadcast address" |
| //usage: "\n -n Display calculated network address" |
| //usage: "\n -m Display default netmask for IP" |
| //usage: IF_FEATURE_IPCALC_FANCY( |
| //usage: "\n -p Display the prefix for IP/NETMASK" |
| //usage: "\n -h Display first resolved host name" |
| //usage: "\n -s Don't ever display error messages" |
| //usage: ) |
| //usage: ) |
| |
| #include "libbb.h" |
| /* After libbb.h, because on some systems it needs other includes */ |
| #include <arpa/inet.h> |
| |
| #define CLASS_A_NETMASK ntohl(0xFF000000) |
| #define CLASS_B_NETMASK ntohl(0xFFFF0000) |
| #define CLASS_C_NETMASK ntohl(0xFFFFFF00) |
| |
| static unsigned long get_netmask(unsigned long ipaddr) |
| { |
| ipaddr = htonl(ipaddr); |
| |
| if ((ipaddr & 0xC0000000) == 0xC0000000) |
| return CLASS_C_NETMASK; |
| else if ((ipaddr & 0x80000000) == 0x80000000) |
| return CLASS_B_NETMASK; |
| else if ((ipaddr & 0x80000000) == 0) |
| return CLASS_A_NETMASK; |
| else |
| return 0; |
| } |
| |
| #if ENABLE_FEATURE_IPCALC_FANCY |
| static int get_prefix(unsigned long netmask) |
| { |
| unsigned long msk = 0x80000000; |
| int ret = 0; |
| |
| netmask = htonl(netmask); |
| while (msk) { |
| if (netmask & msk) |
| ret++; |
| msk >>= 1; |
| } |
| return ret; |
| } |
| #else |
| int get_prefix(unsigned long netmask); |
| #endif |
| |
| |
| #define NETMASK 0x01 |
| #define BROADCAST 0x02 |
| #define NETWORK 0x04 |
| #define NETPREFIX 0x08 |
| #define HOSTNAME 0x10 |
| #define SILENT 0x20 |
| |
| #if ENABLE_FEATURE_IPCALC_LONG_OPTIONS |
| static const char ipcalc_longopts[] ALIGN1 = |
| "netmask\0" No_argument "m" // netmask from IP (assuming complete class A, B, or C network) |
| "broadcast\0" No_argument "b" // broadcast from IP [netmask] |
| "network\0" No_argument "n" // network from IP [netmask] |
| # if ENABLE_FEATURE_IPCALC_FANCY |
| "prefix\0" No_argument "p" // prefix from IP[/prefix] [netmask] |
| "hostname\0" No_argument "h" // hostname from IP |
| "silent\0" No_argument "s" // don’t ever display error messages |
| # endif |
| ; |
| #endif |
| |
| int ipcalc_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
| int ipcalc_main(int argc UNUSED_PARAM, char **argv) |
| { |
| unsigned opt; |
| bool have_netmask = 0; |
| struct in_addr s_netmask, s_broadcast, s_network, s_ipaddr; |
| /* struct in_addr { in_addr_t s_addr; } and in_addr_t |
| * (which in turn is just a typedef to uint32_t) |
| * are essentially the same type. A few macros for less verbosity: */ |
| #define netmask (s_netmask.s_addr) |
| #define broadcast (s_broadcast.s_addr) |
| #define network (s_network.s_addr) |
| #define ipaddr (s_ipaddr.s_addr) |
| char *ipstr; |
| |
| #if ENABLE_FEATURE_IPCALC_LONG_OPTIONS |
| applet_long_options = ipcalc_longopts; |
| #endif |
| opt_complementary = "-1:?2"; /* minimum 1 arg, maximum 2 args */ |
| opt = getopt32(argv, "mbn" IF_FEATURE_IPCALC_FANCY("phs")); |
| argv += optind; |
| if (opt & SILENT) |
| logmode = LOGMODE_NONE; /* suppress error_msg() output */ |
| opt &= ~SILENT; |
| if (!(opt & (BROADCAST | NETWORK | NETPREFIX))) { |
| /* if no options at all or |
| * (no broadcast,network,prefix) and (two args)... */ |
| if (!opt || argv[1]) |
| bb_show_usage(); |
| } |
| |
| ipstr = argv[0]; |
| if (ENABLE_FEATURE_IPCALC_FANCY) { |
| unsigned long netprefix = 0; |
| char *prefixstr; |
| |
| prefixstr = ipstr; |
| |
| while (*prefixstr) { |
| if (*prefixstr == '/') { |
| *prefixstr++ = '\0'; |
| if (*prefixstr) { |
| unsigned msk; |
| netprefix = xatoul_range(prefixstr, 0, 32); |
| netmask = 0; |
| msk = 0x80000000; |
| while (netprefix > 0) { |
| netmask |= msk; |
| msk >>= 1; |
| netprefix--; |
| } |
| netmask = htonl(netmask); |
| /* Even if it was 0, we will signify that we have a netmask. This allows */ |
| /* for specification of default routes, etc which have a 0 netmask/prefix */ |
| have_netmask = 1; |
| } |
| break; |
| } |
| prefixstr++; |
| } |
| } |
| |
| if (inet_aton(ipstr, &s_ipaddr) == 0) { |
| bb_error_msg_and_die("bad IP address: %s", argv[0]); |
| } |
| |
| if (argv[1]) { |
| if (ENABLE_FEATURE_IPCALC_FANCY && have_netmask) { |
| bb_error_msg_and_die("use prefix or netmask, not both"); |
| } |
| if (inet_aton(argv[1], &s_netmask) == 0) { |
| bb_error_msg_and_die("bad netmask: %s", argv[1]); |
| } |
| } else { |
| /* JHC - If the netmask wasn't provided then calculate it */ |
| if (!ENABLE_FEATURE_IPCALC_FANCY || !have_netmask) |
| netmask = get_netmask(ipaddr); |
| } |
| |
| if (opt & NETMASK) { |
| printf("NETMASK=%s\n", inet_ntoa(s_netmask)); |
| } |
| |
| if (opt & BROADCAST) { |
| broadcast = (ipaddr & netmask) | ~netmask; |
| printf("BROADCAST=%s\n", inet_ntoa(s_broadcast)); |
| } |
| |
| if (opt & NETWORK) { |
| network = ipaddr & netmask; |
| printf("NETWORK=%s\n", inet_ntoa(s_network)); |
| } |
| |
| if (ENABLE_FEATURE_IPCALC_FANCY) { |
| if (opt & NETPREFIX) { |
| printf("PREFIX=%i\n", get_prefix(netmask)); |
| } |
| |
| if (opt & HOSTNAME) { |
| struct hostent *hostinfo; |
| |
| hostinfo = gethostbyaddr((char *) &ipaddr, sizeof(ipaddr), AF_INET); |
| if (!hostinfo) { |
| bb_herror_msg_and_die("can't find hostname for %s", argv[0]); |
| } |
| str_tolower(hostinfo->h_name); |
| |
| printf("HOSTNAME=%s\n", hostinfo->h_name); |
| } |
| } |
| |
| return EXIT_SUCCESS; |
| } |