mdw@git.distorted.org.uk Git - misc/blob - gai.c

   1 #define _GNU_SOURCE
   2
   3 #include <ctype.h>
   4 #include <errno.h>
   5 #include <limits.h>
   6 #include <stdio.h>
   7 #include <stdlib.h>
   8 #include <string.h>
   9
  10 #include <getopt.h>
  11
  12 #include <netdb.h>
  13
  14 struct nameval { const char *name; int val; };
  15 const char *prog = "<unset>";
  16
  17 static int parseint(const char *s, const char *what)
  18 {
  19   char *q;
  20   unsigned long i;
  21   int e = errno;
  22
  23   if (!isdigit((unsigned char)*s)) goto fail;
  24   errno = 0;
  25   i = strtoul(s, &q, 0);
  26   if (errno || *q || i > INT_MAX) goto fail;
  27   errno = e;
  28   return ((int)i);
  29
  30 fail:
  31   fprintf(stderr, "%s: bad numeric %s `%s'\n", prog, what, s);
  32   exit(1);
  33 }
  34
  35 static int lookup(const char *name, const char *what,
  36                   const struct nameval *nv)
  37 {
  38   if (isdigit((unsigned char)*name))
  39     return (parseint(name, what));
  40   for (; nv->name; nv++)
  41     if (strcmp(nv->name, name) == 0) return nv->val;
  42   fprintf(stderr, "%s: unknown %s `%s'\n", prog, what, name);
  43   exit(1);
  44 }
  45
  46 static const char *rlookup(int val, const char *what,
  47                            const struct nameval *nv)
  48 {
  49   static char buf[32];
  50   for (; nv->name; nv++)
  51     if (nv->val == val) return (nv->name);
  52   sprintf(buf, "%s#%d", what, val);
  53   return (buf);
  54 }
  55
  56 static const struct nameval familymap[] = {
  57   { "unspec", AF_UNSPEC },
  58   { "inet", AF_INET },
  59   { "inet6", AF_INET6 },
  60   { 0 }
  61 };
  62
  63 static const struct nameval typemap[] = {
  64   { "any", 0 },
  65   { "stream", SOCK_STREAM },
  66   { "dgram", SOCK_DGRAM },
  67   { "raw", SOCK_RAW },
  68   { 0 }
  69 };
  70
  71 static void usage(FILE *fp)
  72 {
  73   fprintf(fp,
  74           "Usage: %s "
  75           "[-CNacgimnsuv] [-f FAMILY] [-p PROTOCOL] [-t TYPE] "
  76           "NAME [SERVICE]\n",
  77           prog);
  78 }
  79
  80 static void help(FILE *fp)
  81 {
  82   usage(fp); fputs("\n\
  83 Options:\n\
  84 \n\
  85   -a plain v4 also (with -m)            -n numeric host\n\
  86   -c canonify name                      -N numeric service\n\
  87   -C canonify to IDN (with -c)          -s allow unassigned codepoints\n\
  88   -g families with configured addrs     -u check result is STD3 hostname\n\
  89   -i convert to IDN                     -v passive\n\
  90   -m v6-mapped v4 addresses\n\
  91 \n\
  92   -f unspec|inet|inet6                  NAME -- hostname or `-' for none\n\
  93   -p PROTOCOL -- /etc/protocols         SERVICE -- number or /etc/services\n\
  94   -t any|stream|dgram|raw\n\
  95 ", fp);
  96 }
  97
  98 int main(int argc, char *argv[])
  99 {
 100   struct addrinfo *ai, hint = { .ai_family = AF_UNSPEC };
 101   const char *name;
 102   const char *serv = 0;
 103   char namebuf[NI_MAXHOST], servbuf[NI_MAXSERV];
 104   int err;
 105
 106   prog = strrchr(argv[0], '/');
 107   if (prog) prog++;
 108   else prog = argv[0];
 109
 110   for (;;) {
 111     int opt = getopt(argc, argv, "hf:t:p:nNcvgamiCus");
 112     if (opt < 0) break;
 113     switch (opt) {
 114       case 'h': help(stdout); exit(0);
 115       case 'f':
 116         hint.ai_family = lookup(optarg, "family", familymap);
 117         break;
 118       case 't':
 119         hint.ai_socktype = lookup(optarg, "type", typemap);
 120         break;
 121       case 'p':
 122         if (isdigit((unsigned char)*optarg))
 123           hint.ai_protocol = parseint(optarg, "protocol");
 124         else {
 125           struct protoent *p = getprotobyname(optarg);
 126           if (!p) {
 127             fprintf(stderr, "%s: unknown protocol `%s'\n", prog, optarg);
 128             exit(1);
 129           }
 130           hint.ai_protocol = p->p_proto;
 131         }
 132         break;
 133       case 'C': hint.ai_flags |= AI_CANONIDN; break;
 134       case 'N': hint.ai_flags |= AI_NUMERICSERV; break;
 135       case 'a': hint.ai_flags |= AI_ALL; break;
 136       case 'c': hint.ai_flags |= AI_CANONNAME; break;
 137       case 'g': hint.ai_flags |= AI_ADDRCONFIG; break;
 138       case 'i': hint.ai_flags |= AI_IDN; break;
 139       case 'm': hint.ai_flags |= AI_V4MAPPED; break;
 140       case 'n': hint.ai_flags |= AI_NUMERICHOST; break;
 141       case 's': hint.ai_flags |= AI_IDN_USE_STD3_ASCII_RULES; break;
 142       case 'u': hint.ai_flags |= AI_IDN_ALLOW_UNASSIGNED; break;
 143       case 'v': hint.ai_flags |= AI_PASSIVE; break;
 144       default: usage(stderr); exit(1);
 145     }
 146   }
 147
 148   argv += optind;
 149   if (!*argv) { usage(stderr); exit(1); } name = *argv++;
 150   if (*argv) { serv = *argv++; }
 151   if (*argv) { usage(stderr); exit(1); }
 152
 153   if (strcmp(name, "-") == 0) name = 0;
 154
 155   if ((err = getaddrinfo(name, serv, &hint, &ai)) != 0) {
 156     fprintf(stderr, "%s: %s\n", prog, gai_strerror(err));
 157     exit(1);
 158   }
 159
 160   for (; ai; ai = ai->ai_next) {
 161     if (ai->ai_canonname) printf("[%s]\n", ai->ai_canonname);
 162     fputs(rlookup(ai->ai_family, "family", familymap), stdout);
 163     fputc(' ', stdout);
 164     fputs(rlookup(ai->ai_socktype, "type", typemap), stdout);
 165     fputc(' ', stdout);
 166     if ((err = getnameinfo(ai->ai_addr, ai->ai_addrlen,
 167                            namebuf, sizeof(namebuf),
 168                            servbuf, sizeof(servbuf),
 169                            (NI_NUMERICHOST | NI_NUMERICSERV |
 170                             (ai->ai_socktype == SOCK_DGRAM ?
 171                              NI_DGRAM : 0)))) != 0)
 172       printf("(error: %s)", gai_strerror(err));
 173     else
 174       printf("%s %s", namebuf, servbuf);
 175     fputc('\n', stdout);
 176   }
 177
 178   freeaddrinfo(ai);
 179
 180   return (0);
 181 }