networking/ipcalc.c

   1 /* vi: set sw=4 ts=4 ai: */
   2 /*
   3  * Mini ipcalc implementation for busybox
   4  *
   5  * By Jordan Crouse <jordan@cosmicpenguin.net>
   6  *    Stephan Linz  <linz@li-pro.net>
   7  *
   8  * This is a complete reimplentation of the ipcalc program
   9  * from Redhat.  I didn't look at their source code, but there
  10  * is no denying that this is a loving reimplementation
  11  */
  12
  13 #include <stdio.h>
  14 #include <stdlib.h>
  15 #include <ctype.h>
  16 #include <getopt.h>
  17 #include <sys/socket.h>
  18 #include <netinet/in.h>
  19 #include <arpa/inet.h>
  20
  21 #include "busybox.h"
  22
  23 #define IPCALC_MSG(CMD,ALTCMD) if (mode & SILENT) {ALTCMD;} else {CMD;}
  24
  25 static unsigned long get_netmask(unsigned long ipaddr)
  26 {
  27         if (ipaddr & 0xC0) {
  28                 return 0x00FFFFFF;      /* Class C */
  29         }
  30         if (ipaddr & 0x10) {
  31                 return 0x0000FFFF;      /* Class B */
  32         }
  33         return 0x000000FF;      /* Class A */
  34 }
  35
  36 #define NETMASK   0x01
  37 #define BROADCAST 0x02
  38 #define NETWORK   0x04
  39 #define HOSTNAME  0x08
  40 #define SILENT    0x10
  41
  42 int ipcalc_main(int argc, char **argv)
  43 {
  44         unsigned long mode;
  45
  46         unsigned long netmask = 0;
  47         unsigned long broadcast;
  48         unsigned long network;
  49         unsigned long ipaddr;
  50
  51         static const struct option long_options[] = {
  52                 {"netmask", no_argument, NULL, 'n'},
  53                 {"broadcast", no_argument, NULL, 'b'},
  54                 {"network", no_argument, NULL, 'w'},
  55 #ifdef CONFIG_FEATURE_IPCALC_FANCY
  56                 {"hostname", no_argument, NULL, 'h'},
  57                 {"silent", no_argument, NULL, 's'},
  58 #endif
  59                 {NULL, 0, NULL, 0}
  60         };
  61
  62         bb_applet_long_options = long_options;
  63         mode = bb_getopt_ulflags(argc, argv,
  64 #ifdef CONFIG_FEATURE_IPCALC_FANCY
  65                                                           "nbwhs");
  66 #else
  67                                                           "nbw");
  68 #endif
  69         if (mode & (BROADCAST | NETWORK)) {
  70                 if (argc - optind > 2) {
  71                         bb_show_usage();
  72                 }
  73         } else {
  74                 if (argc - optind != 1) {
  75                         bb_show_usage();
  76                 }
  77         }
  78
  79         ipaddr = inet_addr(argv[optind]);
  80
  81         if (ipaddr == INADDR_NONE) {
  82                 IPCALC_MSG(bb_error_msg_and_die("bad IP address: %s", argv[optind]),
  83                                    exit(EXIT_FAILURE));
  84         }
  85
  86
  87         if (argc - optind == 2) {
  88                 netmask = inet_addr(argv[optind + 1]);
  89         }
  90
  91         if (ipaddr == INADDR_NONE) {
  92                 IPCALC_MSG(bb_error_msg_and_die("bad netmask: %s", argv[optind + 1]),
  93                                    exit(EXIT_FAILURE));
  94         }
  95
  96         /* JHC - If the netmask wasn't provided then calculate it */
  97         if (!netmask) {
  98                 netmask = get_netmask(ipaddr);
  99         }
 100
 101         if (mode & NETMASK) {
 102                 printf("NETMASK=%s\n", inet_ntoa((*(struct in_addr *) &netmask)));
 103         }
 104
 105         if (mode & BROADCAST) {
 106                 broadcast = (ipaddr & netmask) | ~netmask;
 107                 printf("BROADCAST=%s\n", inet_ntoa((*(struct in_addr *) &broadcast)));
 108         }
 109
 110         if (mode & NETWORK) {
 111                 network = ipaddr & netmask;
 112                 printf("NETWORK=%s\n", inet_ntoa((*(struct in_addr *) &network)));
 113         }
 114 #ifdef CONFIG_FEATURE_IPCALC_FANCY
 115         if (mode & HOSTNAME) {
 116                 struct hostent *hostinfo;
 117                 int x;
 118
 119                 hostinfo = gethostbyaddr((char *) &ipaddr, sizeof(ipaddr), AF_INET);
 120                 if (!hostinfo) {
 121                         IPCALC_MSG(bb_herror_msg_and_die(
 122                                 "cannot find hostname for %s", argv[optind]),);
 123                         exit(EXIT_FAILURE);
 124                 }
 125                 for (x = 0; hostinfo->h_name[x]; x++) {
 126                         hostinfo->h_name[x] = tolower(hostinfo->h_name[x]);
 127                 }
 128
 129                 printf("HOSTNAME=%s\n", hostinfo->h_name);
 130         }
 131 #endif
 132
 133         return EXIT_SUCCESS;
 134 }
 135
 136 /* END CODE */
 137 /*
 138 Local Variables:
 139 c-file-style: "linux"
 140 c-basic-offset: 4
 141 tab-width: 4
 142 End:
 143 */