mdw@git.distorted.org.uk Git - qmail/blob - addrcheck.c

   1 #include "cdb.h"
   2 #include "stralloc.h"
   3 #include "byte.h"
   4 #include "str.h"
   5 #include "addrcheck.h"
   6 #include <errno.h>
   7 #include <unistd.h>
   8
   9 /* #define DEBUG */
  10 #ifdef DEBUG
  11 #  define D(x) x
  12 #  include <stdio.h>
  13 #  include <sys/types.h>
  14 #else
  15 #  define D(x)
  16 #endif
  17
  18 #define STRALLOC_INIT { 0 }
  19
  20 static int probe(int cdb, int prefix, const char *key, int len,
  21                  const char *suffix, const char **kp, uint32 *dlen)
  22 {
  23   static stralloc k = STRALLOC_INIT;
  24   char ch = prefix;
  25   int rc;
  26
  27   k.len = 0;
  28   if (!stralloc_append(&k, &ch) ||
  29       !stralloc_catb(&k, key, len) ||
  30       (suffix && !stralloc_cats(&k, suffix)) ||
  31       !stralloc_0(&k))
  32     return (-1);
  33   if (kp) *kp = k.s;
  34   D( fprintf(stderr, "*** `%.*s' -> ", k.len, k.s); )
  35   rc = cdb_seek(cdb, k.s, k.len - 1, dlen);
  36   D( if (rc == -1)
  37        fprintf(stderr, "error: %s\n", strerror(errno));
  38      else if (rc == 0)
  39        fprintf(stderr, "not found\n");
  40      else if (!*dlen)
  41        fprintf(stderr, "empty\n");
  42      else {
  43        int n = *dlen;
  44        int nn;
  45        char buf[256];
  46        off_t pos = lseek(cdb, 0, SEEK_CUR);
  47        fprintf(stderr, "`");
  48        while (n) {
  49          nn = sizeof(buf); if (nn > n) nn = n;
  50          read(cdb, buf, nn);
  51          fwrite(buf, 1, nn, stderr);
  52          n -= nn;
  53        }
  54        fprintf(stderr, "'\n");
  55        lseek(cdb, pos, SEEK_SET);
  56      } )
  57   return (rc);
  58 }
  59
  60 static int localprobe(int cdb, const char *sender,
  61                       const char *key, int len,
  62                       const char *suffix, const char *tail, int *rc)
  63 {
  64   int err;
  65   uint32 dlen;
  66   char ch;
  67   const char *k;
  68   static stralloc u =  STRALLOC_INIT;
  69   static stralloc serv = STRALLOC_INIT;
  70   int kid;
  71   int n;
  72   int wstat;
  73   int p[2];
  74
  75   if ((err = probe(cdb, 'L', key, len, suffix, &k, &dlen)) < 0)
  76     return (-1);
  77   if (!err) { *rc = 0; return (0); }
  78   if (!dlen) { errno = EINVAL; return (-1); }
  79   if (read(cdb, &ch, 1) != 1) { errno = EIO; return (-1); }
  80   if (ch == '?') {
  81     u.len = 0;
  82     if (!stralloc_ready(&u, dlen - 1)) return (-1);
  83     if (read(cdb, u.s, dlen - 1) != dlen - 1) { errno = EIO; return (-1); }
  84     u.len = dlen - 1;
  85     serv.len = 0;
  86     if (!stralloc_cats(&serv, "addrcheck:") ||
  87         !stralloc_cats(&serv, k + 1) ||
  88         !stralloc_0(&serv) ||
  89         !stralloc_0(&u))
  90       return (-1);
  91     D( fprintf(stderr, "asking user:\n\
  92   user = %s; service = %s\n  tail = %s; sender = %s\n\
  93   address = %s; key = %s\n",
  94                u.s, serv.s, tail, sender, key, k + 1); )
  95
  96     if (pipe(p) || (kid = fork()) == -1)
  97       return (-1);
  98     if (!kid) {
  99       dup2(p[1], 1);
 100       close(p[0]);
 101       close(p[1]);
 102       execl("/usr/bin/userv", "/usr/bin/userv",
 103             "-f", "stdin=/dev/null",
 104             u.s, serv.s,
 105             tail, sender, key, k + 1,
 106             (char *)0);
 107       _exit(127);
 108     }
 109     close(p[1]);
 110     n = read(p[0], &ch, 1);
 111     close(p[0]);
 112     if (wait_pid(&wstat, kid) < 0) { return (-1); }
 113     D( fprintf(stderr, "userv exited with status %d\n", wstat); )
 114     if (n != 1 || wstat) { errno = EAGAIN; return (-1); }
 115     D( fprintf(stderr, "userv answer was `%c'\n", ch); )
 116   } else if (dlen != 1) {
 117     errno = EIO;
 118     return (-1);
 119   }
 120   *rc = ch;
 121   return (1);
 122 }
 123
 124 static int local(int cdb, const char *l, int len,
 125                  const char *sender, int *rc)
 126 {
 127   int code;
 128   int err = 0;
 129   int dash;
 130
 131   if ((err = localprobe(cdb, sender, l, len, 0, l + len, &code)) != 0)
 132     goto done;
 133
 134   for (;;) {
 135     dash = byte_rchr(l, len, '-');
 136     if (dash == len) break;
 137     if ((err = localprobe(cdb, sender,
 138                           l, dash, "-default", l + dash + 1, &code)) != 0)
 139       goto done;
 140     len = dash;
 141   }
 142   *rc = 0;
 143   return (0);
 144
 145 done:
 146   if (err >= 0) {
 147     switch (code) {
 148       case '+': *rc = 1; break;
 149       case '-': *rc = 0; break;
 150       default: errno = EINVAL; err = -1; break;
 151     }
 152   }
 153   return (err);
 154 }
 155
 156 static int virt(int cdb, const char *u, int ulen,
 157                 const char *addr, int alen, const char *sender, int *rc)
 158 {
 159   static stralloc l = STRALLOC_INIT;
 160   uint32 dlen;
 161   int err;
 162
 163   if ((err = probe(cdb, 'V', addr, alen, 0, 0, &dlen)) <= 0)
 164     return (err);
 165   if (!stralloc_ready(&l, dlen + 1)) return (-1);
 166   if (read(cdb, l.s, dlen) != dlen) { errno = EIO; return (-1); }
 167   l.s[dlen] = '-';
 168   l.len = dlen + 1;
 169   if (!stralloc_catb(&l, u, ulen) || !stralloc_0(&l)) return (-1);
 170   D( printf("*** virtual map -> `%s'\n", l.s); )
 171   if (local(cdb, l.s, l.len - 1, sender, rc) < 0) return (-1);
 172   return (1);
 173 }
 174
 175 int addrcheck(int cdb, const char *addr, const char *sender, int *rc)
 176 {
 177   int at, len, dot;
 178   int err = 0;
 179   uint32 dlen;
 180
 181   len = str_len(addr);
 182   at = str_chr(addr, '@');
 183   if (!addr[at])
 184     return (local(cdb, addr, len, sender, rc));
 185
 186   if ((err = virt(cdb, addr, at, addr, len, sender, rc)) != 0)
 187     return (err);
 188   dot = at + 1;
 189   while (addr[dot]) {
 190     if ((err = virt(cdb, addr, at, addr + dot, len - dot, sender, rc)) != 0)
 191       return (err);
 192     dot += byte_chr(addr + dot + 1, len - dot - 1, '.') + 1;
 193   }
 194
 195   if ((err = probe(cdb, '@', addr + at + 1, len - at - 1, 0, 0, &dlen)) < 0)
 196     return (-1);
 197   if (!err) { *rc = 1; return (0); }
 198   if (dlen != 0) { errno = EINVAL; return (-1); }
 199
 200   return (local(cdb, addr, at, sender, rc));
 201 }
 202
 203 #ifdef TEST
 204
 205 #include <sys/types.h>
 206 #include <unistd.h>
 207 #include <fcntl.h>
 208 #include <stdio.h>
 209 #include <errno.h>
 210 #include <unistd.h>
 211
 212 int main(int argc, char *argv[])
 213 {
 214   int fd;
 215   int rc;
 216   int i;
 217
 218   if (argc < 4) {
 219     fprintf(stderr, "usage: addrcheck CDB SENDER ADDR...\n");
 220     return (1);
 221   }
 222   if ((fd = open(argv[1], O_RDONLY)) < 0) {
 223     perror(argv[1]);
 224     return (1);
 225   }
 226   for (i = 3; i < argc; i++) {
 227     if (addrcheck(fd, argv[i], argv[2], &rc) < 0) {
 228       perror("checking");
 229       return (1);
 230     }
 231     printf("%s: %s\n", argv[i], rc ? "ok" : "bad");
 232   }
 233   return (0);
 234 }
 235
 236 #endif