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    0x80
  41
  42 int ipcalc_main(int argc, char **argv)
  43 {
  44         unsigned char mode = 0;
  45
  46         unsigned long netmask = 0;
  47         unsigned long broadcast = 0;
  48         unsigned long network = 0;
  49         unsigned long ipaddr = 0;
  50
  51         int opt = 0;
  52
  53         struct option long_options[] = {
  54                 {"netmask", no_argument, NULL, 'n'},
  55                 {"broadcast", no_argument, NULL, 'b'},
  56                 {"network", no_argument, NULL, 'w'},
  57 #ifdef CONFIG_FEATURE_IPCALC_FANCY
  58                 {"hostname", no_argument, NULL, 'h'},
  59                 {"silent", no_argument, NULL, 's'},
  60 #endif
  61                 {NULL, 0, NULL, 0}
  62         };
  63
  64
  65         while ((opt = getopt_long(argc, argv,
  66 #ifdef CONFIG_FEATURE_IPCALC_FANCY
  67                                                           "nbwhs",
  68 #else
  69                                                           "nbw",
  70 #endif
  71                                                           long_options, NULL)) != EOF) {
  72                 if (opt == 'n')
  73                         mode |= NETMASK;
  74                 else if (opt == 'b')
  75                         mode |= BROADCAST;
  76                 else if (opt == 'w')
  77                         mode |= NETWORK;
  78 #ifdef CONFIG_FEATURE_IPCALC_FANCY
  79                 else if (opt == 'h')
  80                         mode |= HOSTNAME;
  81                 else if (opt == 's')
  82                         mode |= SILENT;
  83 #endif
  84                 else {
  85                         bb_show_usage();
  86                 }
  87         }
  88
  89         if (mode & (BROADCAST | NETWORK)) {
  90                 if (argc - optind > 2) {
  91                         bb_show_usage();
  92                 }
  93         } else {
  94                 if (argc - optind != 1) {
  95                         bb_show_usage();
  96                 }
  97         }
  98
  99         ipaddr = inet_addr(argv[optind]);
 100
 101         if (ipaddr == INADDR_NONE) {
 102                 IPCALC_MSG(bb_error_msg_and_die("bad IP address: %s\n", argv[optind]),
 103                                    exit(EXIT_FAILURE));
 104         }
 105
 106
 107         if (argc - optind == 2) {
 108                 netmask = inet_addr(argv[optind + 1]);
 109         }
 110
 111         if (ipaddr == INADDR_NONE) {
 112                 IPCALC_MSG(bb_error_msg_and_die("bad netmask: %s\n", argv[optind + 1]),
 113                                    exit(EXIT_FAILURE));
 114         }
 115
 116         /* JHC - If the netmask wasn't provided then calculate it */
 117         if (!netmask) {
 118                 netmask = get_netmask(ipaddr);
 119         }
 120
 121         if (mode & NETMASK) {
 122                 printf("NETMASK=%s\n", inet_ntoa((*(struct in_addr *) &netmask)));
 123         }
 124
 125         if (mode & BROADCAST) {
 126                 broadcast = (ipaddr & netmask) | ~netmask;
 127                 printf("BROADCAST=%s\n", inet_ntoa((*(struct in_addr *) &broadcast)));
 128         }
 129
 130         if (mode & NETWORK) {
 131                 network = ipaddr & netmask;
 132                 printf("NETWORK=%s\n", inet_ntoa((*(struct in_addr *) &network)));
 133         }
 134 #ifdef CONFIG_FEATURE_IPCALC_FANCY
 135         if (mode & HOSTNAME) {
 136                 struct hostent *hostinfo;
 137                 int x;
 138
 139                 hostinfo = gethostbyaddr((char *) &ipaddr, sizeof(ipaddr), AF_INET);
 140                 if (!hostinfo) {
 141                         IPCALC_MSG(bb_error_msg("cannot find hostname for %s", argv[optind]);
 142                                            herror(NULL);
 143                                            putc('\n', stderr);,);
 144                         exit(EXIT_FAILURE);
 145                 }
 146                 for (x = 0; hostinfo->h_name[x]; x++) {
 147                         hostinfo->h_name[x] = tolower(hostinfo->h_name[x]);
 148                 }
 149
 150                 printf("HOSTNAME=%s\n", hostinfo->h_name);
 151         }
 152 #endif
 153
 154         return EXIT_SUCCESS;
 155 }
 156
 157 /* END CODE */
 158 /*
 159 Local Variables:
 160 c-file-style: "linux"
 161 c-basic-offset: 4
 162 tab-width: 4
 163 End:
 164 */