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

   1 #include <sys/types.h>
   2 #include <sys/socket.h>
   3 #include <netinet/in.h>
   4 #include <arpa/inet.h>
   5 #include "sig.h"
   6 #include "getln.h"
   7 #include "stralloc.h"
   8 #include "substdio.h"
   9 #include "subfd.h"
  10 #include "scan.h"
  11 #include "case.h"
  12 #include "error.h"
  13 #include "auto_qmail.h"
  14 #include "control.h"
  15 #include "dns.h"
  16 #include "alloc.h"
  17 #include "quote.h"
  18 #include "ip.h"
  19 #include "ipalloc.h"
  20 #include "ipme.h"
  21 #include "gen_alloc.h"
  22 #include "gen_allocdefs.h"
  23 #include "str.h"
  24 #include "now.h"
  25 #include "exit.h"
  26 #include "constmap.h"
  27 #include "tcpto.h"
  28 #include "timeoutconn.h"
  29 #include "timeoutread.h"
  30 #include "timeoutwrite.h"
  31
  32 #define HUGESMTPTEXT 5000
  33
  34 #define PORT_SMTP 25 /* silly rabbit, /etc/services is for users */
  35 unsigned long port = PORT_SMTP;
  36
  37 GEN_ALLOC_typedef(saa,stralloc,sa,len,a)
  38 GEN_ALLOC_readyplus(saa,stralloc,sa,len,a,i,n,x,10,saa_readyplus)
  39 static stralloc sauninit = {0};
  40
  41 stralloc helohost = {0};
  42 stralloc routes = {0};
  43 struct constmap maproutes;
  44 stralloc host = {0};
  45 stralloc sender = {0};
  46
  47 saa reciplist = {0};
  48
  49 struct ip_address partner;
  50
  51 void out(s) char *s; { if (substdio_puts(subfdout,s) == -1) _exit(0); }
  52 void zero() { if (substdio_put(subfdout,"\0",1) == -1) _exit(0); }
  53 void zerodie() { zero(); substdio_flush(subfdout); _exit(0); }
  54
  55 void outsafe(sa) stralloc *sa; { int i; char ch;
  56 for (i = 0;i < sa->len;++i) {
  57 ch = sa->s[i]; if (ch < 33) ch = '?'; if (ch > 126) ch = '?';
  58 if (substdio_put(subfdout,&ch,1) == -1) _exit(0); } }
  59
  60 void temp_nomem() { out("ZOut of memory. (#4.3.0)\n"); zerodie(); }
  61 void temp_oserr() { out("Z\
  62 System resources temporarily unavailable. (#4.3.0)\n"); zerodie(); }
  63 void temp_noconn() { out("Z\
  64 Sorry, I wasn't able to establish an SMTP connection. (#4.4.1)\n"); zerodie(); }
  65 void temp_read() { out("ZUnable to read message. (#4.3.0)\n"); zerodie(); }
  66 void temp_dnscanon() { out("Z\
  67 CNAME lookup failed temporarily. (#4.4.3)\n"); zerodie(); }
  68 void temp_dns() { out("Z\
  69 Sorry, I couldn't find any host by that name. (#4.1.2)\n"); zerodie(); }
  70 void temp_chdir() { out("Z\
  71 Unable to switch to home directory. (#4.3.0)\n"); zerodie(); }
  72 void temp_control() { out("Z\
  73 Unable to read control files. (#4.3.0)\n"); zerodie(); }
  74 void perm_partialline() { out("D\
  75 SMTP cannot transfer messages with partial final lines. (#5.6.2)\n"); zerodie(); }
  76 void perm_usage() { out("D\
  77 I (qmail-remote) was invoked improperly. (#5.3.5)\n"); zerodie(); }
  78 void perm_dns() { out("D\
  79 Sorry, I couldn't find any host named ");
  80 outsafe(&host);
  81 out(". (#5.1.2)\n"); zerodie(); }
  82 void perm_nomx() { out("D\
  83 Sorry, I couldn't find a mail exchanger or IP address. (#5.4.4)\n");
  84 zerodie(); }
  85 void perm_ambigmx() { out("D\
  86 Sorry. Although I'm listed as a best-preference MX or A for that host,\n\
  87 it isn't in my control/locals file, so I don't treat it as local. (#5.4.6)\n");
  88 zerodie(); }
  89
  90 int timeout = 1200;
  91 int timeoutconnect = 60;
  92
  93 void getcontrols()
  94 {
  95  int r;
  96  if (control_init() == -1)
  97   { if (errno == error_nomem) temp_nomem(); temp_control(); }
  98
  99  if (control_readint(&timeout,"control/timeoutremote") == -1)
 100   { if (errno == error_nomem) temp_nomem(); temp_control(); }
 101  if (control_readint(&timeoutconnect,"control/timeoutconnect") == -1)
 102   { if (errno == error_nomem) temp_nomem(); temp_control(); }
 103
 104  r = control_rldef(&helohost,"control/helohost",1,(char *) 0);
 105  if (r == -1) if (errno == error_nomem) temp_nomem();
 106  if (r != 1) temp_control();
 107
 108  switch(control_readfile(&routes,"control/smtproutes",0))
 109   {
 110    case -1:
 111      if (errno == error_nomem) temp_nomem(); temp_control();
 112    case 0:
 113      if (!constmap_init(&maproutes,"",0,1)) temp_nomem(); break;
 114    case 1:
 115      if (!constmap_init(&maproutes,routes.s,routes.len,1)) temp_nomem(); break;
 116   }
 117 }
 118
 119 char smtptobuf[1024];
 120 char smtpfrombuf[128];
 121 stralloc smtpline = {0};
 122 stralloc smtptext = {0};
 123
 124 void outsmtptext()
 125 {
 126  int i;
 127  if (smtptext.s) if (smtptext.len) if (smtptext.len < HUGESMTPTEXT)
 128   {
 129    if (substdio_puts(subfdout,"Remote host said: ") == -1) _exit(0);
 130    for (i = 0;i < smtptext.len;++i)
 131      if (!smtptext.s[i]) smtptext.s[i] = '?';
 132    if (substdio_put(subfdout,smtptext.s,smtptext.len) == -1) _exit(0);
 133    smtptext.len = 0;
 134   }
 135 }
 136
 137 unsigned long smtpcode(ss)
 138 substdio *ss;
 139 {
 140  int match;
 141  unsigned long code;
 142
 143  if (!stralloc_copys(&smtptext,"")) return 421;
 144  do
 145   {
 146    if (getln(ss,&smtpline,&match,'\n') != 0) return 421;
 147    if (!match) return 421;
 148    if ((smtpline.len >= 2) && (smtpline.s[smtpline.len - 2] == '\r'))
 149     {
 150      smtpline.s[smtpline.len - 2] = '\n';
 151      --smtpline.len;
 152     }
 153    if (!stralloc_cat(&smtptext,&smtpline)) return 421;
 154    if (scan_nbblong(smtpline.s,smtpline.len,10,0,&code) != 3) return 421;
 155    if (smtpline.len == 3) return code;
 156   }
 157  while (smtpline.s[3] == '-');
 158
 159  return code;
 160 }
 161
 162 void outhost()
 163 {
 164  char x[IPFMT];
 165
 166  x[ip_fmt(x,&partner)] = 0;
 167  out(x);
 168 }
 169
 170 void writeerr()
 171 {
 172  out("ZConnected to "); outhost();
 173  out(" but communications failed. (#4.4.2)\n");
 174  zerodie();
 175 }
 176
 177 void quit(ssto,ssfrom)
 178 substdio *ssto;
 179 substdio *ssfrom;
 180 {
 181  outsmtptext();
 182  if (substdio_putsflush(ssto,"QUIT\r\n") != -1)
 183    smtpcode(ssfrom); /* protocol design stupidity */
 184  zerodie();
 185 }
 186
 187 stralloc dataline = {0};
 188
 189 void blast(ssto,ssfrom)
 190 substdio *ssto;
 191 substdio *ssfrom;
 192 {
 193  int match;
 194
 195  for (;;)
 196   {
 197    if (getln(ssfrom,&dataline,&match,'\n') != 0) temp_read();
 198    if (!match && !dataline.len) break;
 199    if (!match) perm_partialline();
 200    --dataline.len;
 201    if (dataline.len && (dataline.s[0] == '.'))
 202      if (substdio_put(ssto,".",1) == -1) writeerr();
 203    if (substdio_put(ssto,dataline.s,dataline.len) == -1) writeerr();
 204    if (substdio_put(ssto,"\r\n",2) == -1) writeerr();
 205   }
 206  if (substdio_put(ssto,".\r\n",3) == -1) writeerr();
 207  if (substdio_flush(ssto) == -1) writeerr();
 208 }
 209
 210 stralloc recip = {0};
 211
 212 void smtp(fd)
 213 int fd;
 214 {
 215  substdio ssto;
 216  substdio ssfrom;
 217  unsigned long code;
 218  int flaganyrecipok;
 219  int i;
 220
 221  substdio_fdbuf(&ssto,timeoutwrite,TIMEOUTWRITE(timeout,fd),smtptobuf,sizeof(smtptobuf));
 222  substdio_fdbuf(&ssfrom,timeoutread,TIMEOUTREAD(timeout,fd),smtpfrombuf,sizeof(smtpfrombuf));
 223
 224  if (smtpcode(&ssfrom) != 220)
 225   {
 226    out("ZConnected to "); outhost(); out(" but greeting failed.\n");
 227    quit(&ssto,&ssfrom);
 228   }
 229
 230  if (substdio_puts(&ssto,"HELO ") == -1) writeerr();
 231  if (substdio_put(&ssto,helohost.s,helohost.len) == -1) writeerr();
 232  if (substdio_puts(&ssto,"\r\n") == -1) writeerr();
 233  if (substdio_flush(&ssto) == -1) writeerr();
 234
 235  if (smtpcode(&ssfrom) != 250)
 236   {
 237    out("ZConnected to "); outhost(); out(" but my name was rejected.\n");
 238    quit(&ssto,&ssfrom);
 239   }
 240
 241  if (substdio_puts(&ssto,"MAIL FROM:<") == -1) writeerr();
 242  if (substdio_put(&ssto,sender.s,sender.len) == -1) writeerr();
 243  if (substdio_puts(&ssto,">\r\n") == -1) writeerr();
 244  if (substdio_flush(&ssto) == -1) writeerr();
 245
 246  code = smtpcode(&ssfrom);
 247  if (code >= 500)
 248   {
 249    out("DConnected to "); outhost(); out(" but sender was rejected.\n");
 250    quit(&ssto,&ssfrom);
 251   }
 252  if (code >= 400)
 253   {
 254    out("ZConnected to "); outhost(); out(" but sender was rejected.\n");
 255    quit(&ssto,&ssfrom);
 256   }
 257
 258  flaganyrecipok = 0;
 259  for (i = 0;i < reciplist.len;++i)
 260   {
 261    if (substdio_puts(&ssto,"RCPT TO:<") == -1) writeerr();
 262    if (substdio_put(&ssto,reciplist.sa[i].s,reciplist.sa[i].len) == -1) writeerr();
 263    if (substdio_puts(&ssto,">\r\n") == -1) writeerr();
 264    if (substdio_flush(&ssto) == -1) writeerr();
 265
 266    code = smtpcode(&ssfrom);
 267    if (code == 421)
 268     {
 269      out("ZConnected to "); outhost(); out(" but connection died.\n");
 270      quit(&ssto,&ssfrom);
 271     }
 272    if (code >= 500)
 273     {
 274      out("h"); outhost(); out(" does not like recipient.\n");
 275      outsmtptext(); zero();
 276     }
 277    else if (code >= 400)
 278     {
 279      out("s"); outhost(); out(" does not like recipient.\n");
 280      outsmtptext(); zero();
 281     }
 282    else
 283     {
 284      out("r"); zero();
 285      flaganyrecipok = 1;
 286     }
 287   }
 288
 289  if (!flaganyrecipok)
 290   {
 291    out("DGiving up.\n");
 292    quit(&ssto,&ssfrom);
 293   }
 294
 295  if (substdio_putsflush(&ssto,"DATA\r\n") == -1) writeerr();
 296
 297  code = smtpcode(&ssfrom);
 298  if (code == 421)
 299   {
 300    out("ZConnected to "); outhost(); out(" but connection died.\n");
 301    quit(&ssto,&ssfrom);
 302   }
 303  if (code >= 500)
 304   {
 305    out("D"); outhost(); out(" failed on DATA command.\n");
 306    quit(&ssto,&ssfrom);
 307   }
 308  if (code >= 400)
 309   {
 310    out("Z"); outhost(); out(" failed on DATA command.\n");
 311    quit(&ssto,&ssfrom);
 312   }
 313
 314  blast(&ssto,subfdin);
 315
 316  code = smtpcode(&ssfrom);
 317  if (code == 421)
 318   {
 319    out("ZConnected to "); outhost(); out(" but connection died. Possible duplicate!\n");
 320    quit(&ssto,&ssfrom);
 321   }
 322  if (code >= 500)
 323   {
 324    out("D"); outhost(); out(" failed after I sent the message.\n");
 325    quit(&ssto,&ssfrom);
 326   }
 327  if (code >= 400)
 328   {
 329    out("Z"); outhost(); out(" failed after I sent the message.\n");
 330    quit(&ssto,&ssfrom);
 331   }
 332
 333  out("K"); outhost(); out(" accepted message.\n");
 334  quit(&ssto,&ssfrom);
 335 }
 336
 337 stralloc canonhost = {0};
 338 stralloc canonbox = {0};
 339
 340 void addrmangle(saout,s,flagalias,flagcname)
 341 stralloc *saout; /* host has to be canonical, box has to be quoted */
 342 char *s;
 343 int *flagalias;
 344 int flagcname;
 345 {
 346  int j;
 347
 348  *flagalias = flagcname;
 349
 350  j = str_rchr(s,'@');
 351  if (!s[j])
 352   {
 353    if (!stralloc_copys(saout,s)) temp_nomem();
 354    return;
 355   }
 356  if (!stralloc_copys(&canonbox,s)) temp_nomem();
 357  canonbox.len = j;
 358  if (!quote(saout,&canonbox)) temp_nomem();
 359  if (!stralloc_cats(saout,"@")) temp_nomem();
 360
 361  if (!stralloc_copys(&canonhost,s + j + 1)) temp_nomem();
 362  if (flagcname)
 363    switch(dns_cname(&canonhost))
 364     {
 365      case 0: *flagalias = 0; break;
 366      case DNS_MEM: temp_nomem();
 367      case DNS_SOFT: temp_dnscanon();
 368      case DNS_HARD: ; /* alias loop, not our problem */
 369     }
 370
 371  if (!stralloc_cat(saout,&canonhost)) temp_nomem();
 372 }
 373
 374 void main(argc,argv)
 375 int argc;
 376 char **argv;
 377 {
 378  static ipalloc ip = {0};
 379  int i;
 380  unsigned long random;
 381  char **recips;
 382  unsigned long prefme;
 383  int flagallaliases;
 384  int flagalias;
 385  char *relayhost;
 386
 387  sig_pipeignore();
 388  if (argc < 4) perm_usage();
 389  if (chdir(auto_qmail) == -1) temp_chdir();
 390  getcontrols();
 391
 392
 393  if (!stralloc_copys(&host,argv[1])) temp_nomem();
 394
 395  relayhost = 0;
 396  for (i = 0;i <= host.len;++i)
 397    if ((i == 0) || (i == host.len) || (host.s[i] == '.'))
 398      if (relayhost = constmap(&maproutes,host.s + i,host.len - i))
 399        break;
 400  if (relayhost && !*relayhost) relayhost = 0;
 401
 402  if (relayhost)
 403   {
 404    i = str_chr(relayhost,':');
 405    if (relayhost[i])
 406     {
 407      scan_ulong(relayhost + i + 1,&port);
 408      relayhost[i] = 0;
 409     }
 410    if (!stralloc_copys(&host,relayhost)) temp_nomem();
 411   }
 412
 413
 414  addrmangle(&sender,argv[2],&flagalias,!relayhost);
 415
 416  if (!saa_readyplus(&reciplist,0)) temp_nomem();
 417  if (ipme_init() != 1) temp_oserr();
 418
 419  flagallaliases = 1;
 420  recips = argv + 3;
 421  while (*recips)
 422   {
 423    if (!saa_readyplus(&reciplist,1)) temp_nomem();
 424    reciplist.sa[reciplist.len] = sauninit;
 425    addrmangle(reciplist.sa + reciplist.len,*recips,&flagalias,!relayhost);
 426    if (!flagalias) flagallaliases = 0;
 427    ++reciplist.len;
 428    ++recips;
 429   }
 430
 431
 432  random = now() + (getpid() << 16);
 433  switch (relayhost ? dns_ip(&ip,&host) : dns_mxip(&ip,&host,random))
 434   {
 435    case DNS_MEM: temp_nomem();
 436    case DNS_SOFT: temp_dns();
 437    case DNS_HARD: perm_dns();
 438    case 1:
 439      if (ip.len <= 0) temp_dns();
 440   }
 441
 442  if (ip.len <= 0) perm_nomx();
 443
 444  prefme = 100000;
 445  for (i = 0;i < ip.len;++i)
 446    if (ipme_is(&ip.ix[i].ip))
 447      if (ip.ix[i].pref < prefme)
 448        prefme = ip.ix[i].pref;
 449
 450  if (relayhost) prefme = 300000;
 451  if (flagallaliases) prefme = 500000;
 452
 453  for (i = 0;i < ip.len;++i)
 454    if (ip.ix[i].pref < prefme)
 455      break;
 456
 457  if (i >= ip.len)
 458    perm_ambigmx();
 459
 460  for (i = 0;i < ip.len;++i) if (ip.ix[i].pref < prefme)
 461   {
 462    int s;
 463
 464    if (tcpto(&ip.ix[i].ip)) continue;
 465
 466    s = socket(AF_INET,SOCK_STREAM,0);
 467    if (s == -1) temp_oserr();
 468
 469    if (timeoutconn(s,&ip.ix[i].ip,(unsigned int) port,timeoutconnect) == 0)
 470     {
 471      tcpto_err(&ip.ix[i].ip,0);
 472      partner = ip.ix[i].ip;
 473      smtp(s); /* does not return */
 474     }
 475    tcpto_err(&ip.ix[i].ip,errno == error_timeout);
 476    close(s);
 477   }
 478
 479  temp_noconn();
 480 }