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 "stralloc.h"
   7 #include "substdio.h"
   8 #include "subfd.h"
   9 #include "scan.h"
  10 #include "case.h"
  11 #include "error.h"
  12 #include "auto_qmail.h"
  13 #include "control.h"
  14 #include "dns.h"
  15 #include "alloc.h"
  16 #include "quote.h"
  17 #include "ip.h"
  18 #include "ipalloc.h"
  19 #include "ipme.h"
  20 #include "gen_alloc.h"
  21 #include "gen_allocdefs.h"
  22 #include "str.h"
  23 #include "now.h"
  24 #include "exit.h"
  25 #include "constmap.h"
  26 #include "tcpto.h"
  27 #include "readwrite.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(subfdoutsmall,s) == -1) _exit(0); }
  52 void zero() { if (substdio_put(subfdoutsmall,"\0",1) == -1) _exit(0); }
  53 void zerodie() { zero(); substdio_flush(subfdoutsmall); _exit(0); }
  54 void outsafe(sa) stralloc *sa; { int i; char ch;
  55 for (i = 0;i < sa->len;++i) {
  56 ch = sa->s[i]; if (ch < 33) ch = '?'; if (ch > 126) ch = '?';
  57 if (substdio_put(subfdoutsmall,&ch,1) == -1) _exit(0); } }
  58
  59 void temp_nomem() { out("ZOut of memory. (#4.3.0)\n"); zerodie(); }
  60 void temp_oserr() { out("Z\
  61 System resources temporarily unavailable. (#4.3.0)\n"); zerodie(); }
  62 void temp_noconn() { out("Z\
  63 Sorry, I wasn't able to establish an SMTP connection. (#4.4.1)\n"); zerodie(); }
  64 void temp_read() { out("ZUnable to read message. (#4.3.0)\n"); zerodie(); }
  65 void temp_dnscanon() { out("Z\
  66 CNAME lookup failed temporarily. (#4.4.3)\n"); zerodie(); }
  67 void temp_dns() { out("Z\
  68 Sorry, I couldn't find any host by that name. (#4.1.2)\n"); zerodie(); }
  69 void temp_chdir() { out("Z\
  70 Unable to switch to home directory. (#4.3.0)\n"); zerodie(); }
  71 void temp_control() { out("Z\
  72 Unable to read control files. (#4.3.0)\n"); zerodie(); }
  73 void perm_partialline() { out("D\
  74 SMTP cannot transfer messages with partial final lines. (#5.6.2)\n"); zerodie(); }
  75 void perm_usage() { out("D\
  76 I (qmail-remote) was invoked improperly. (#5.3.5)\n"); zerodie(); }
  77 void perm_dns() { out("D\
  78 Sorry, I couldn't find any host named ");
  79 outsafe(&host);
  80 out(". (#5.1.2)\n"); zerodie(); }
  81 void perm_nomx() { out("D\
  82 Sorry, I couldn't find a mail exchanger or IP address. (#5.4.4)\n");
  83 zerodie(); }
  84 void perm_ambigmx() { out("D\
  85 Sorry. Although I'm listed as a best-preference MX or A for that host,\n\
  86 it isn't in my control/locals file, so I don't treat it as local. (#5.4.6)\n");
  87 zerodie(); }
  88
  89 void outhost()
  90 {
  91   char x[IPFMT];
  92   if (substdio_put(subfdoutsmall,x,ip_fmt(x,&partner)) == -1) _exit(0);
  93 }
  94
  95 int flagcritical = 0;
  96
  97 void dropped() {
  98   out("ZConnected to ");
  99   outhost();
 100   out(" but connection died. ");
 101   if (flagcritical) out("Possible duplicate! ");
 102   out("(#4.4.2)\n");
 103   zerodie();
 104 }
 105
 106 int timeoutconnect = 60;
 107 int smtpfd;
 108 int timeout = 1200;
 109
 110 int saferead(fd,buf,len) int fd; char *buf; int len;
 111 {
 112   int r;
 113   r = timeoutread(timeout,smtpfd,buf,len);
 114   if (r <= 0) dropped();
 115   return r;
 116 }
 117 int safewrite(fd,buf,len) int fd; char *buf; int len;
 118 {
 119   int r;
 120   r = timeoutwrite(timeout,smtpfd,buf,len);
 121   if (r <= 0) dropped();
 122   return r;
 123 }
 124
 125 char inbuf[1024];
 126 substdio ssin = SUBSTDIO_FDBUF(read,0,inbuf,sizeof inbuf);
 127 char smtptobuf[1024];
 128 substdio smtpto = SUBSTDIO_FDBUF(safewrite,-1,smtptobuf,sizeof smtptobuf);
 129 char smtpfrombuf[128];
 130 substdio smtpfrom = SUBSTDIO_FDBUF(saferead,-1,smtpfrombuf,sizeof smtpfrombuf);
 131
 132 stralloc smtptext = {0};
 133
 134 void get(ch)
 135 char *ch;
 136 {
 137   substdio_get(&smtpfrom,ch,1);
 138   if (*ch != '\r')
 139     if (smtptext.len < HUGESMTPTEXT)
 140      if (!stralloc_append(&smtptext,ch)) temp_nomem();
 141 }
 142
 143 unsigned long smtpcode()
 144 {
 145   unsigned char ch;
 146   unsigned long code;
 147
 148   if (!stralloc_copys(&smtptext,"")) temp_nomem();
 149
 150   get(&ch); code = ch - '0';
 151   get(&ch); code = code * 10 + (ch - '0');
 152   get(&ch); code = code * 10 + (ch - '0');
 153   for (;;) {
 154     get(&ch);
 155     if (ch != '-') break;
 156     while (ch != '\n') get(&ch);
 157     get(&ch);
 158     get(&ch);
 159     get(&ch);
 160   }
 161   while (ch != '\n') get(&ch);
 162
 163   return code;
 164 }
 165
 166 void outsmtptext()
 167 {
 168   int i;
 169   if (smtptext.s) if (smtptext.len) {
 170     out("Remote host said: ");
 171     for (i = 0;i < smtptext.len;++i)
 172       if (!smtptext.s[i]) smtptext.s[i] = '?';
 173     if (substdio_put(subfdoutsmall,smtptext.s,smtptext.len) == -1) _exit(0);
 174     smtptext.len = 0;
 175   }
 176 }
 177
 178 void quit(prepend,append)
 179 char *prepend;
 180 char *append;
 181 {
 182   substdio_putsflush(&smtpto,"QUIT\r\n");
 183   /* waiting for remote side is just too ridiculous */
 184   out(prepend);
 185   outhost();
 186   out(append);
 187   out(".\n");
 188   outsmtptext();
 189   zerodie();
 190 }
 191
 192 stralloc verh = {0};                            /* quoted recipient */
 193 int flagverh;                                   /* argc */
 194 char *vp;                                       /* argv[3] */
 195
 196 void blast()
 197 {
 198   unsigned int posat, i;
 199   int flagdobody,flagheader;
 200   int r;
 201   char ch;
 202
 203   posat = 0;                                    /* stays 0 if no VERH */
 204   flagdobody = 0;                               /* => 0 at first blank line */
 205   flagheader = 1;
 206   if (flagverh == 4) {                          /* only if single recipient */
 207     if (!quote2(&verh,vp)) temp_nomem();        /* non-canonicalized */
 208     for (i = 0; i < verh.len; i++)              /* \n would destroy message */
 209       if (verh.s[i] == '\n') verh.s[i] = '_';
 210     posat = byte_rchr(verh.s,verh.len,'@');     /* posat=0 if no VERH */
 211     if (posat == verh.len) posat = 0;
 212   }
 213   for (;;) {
 214     r = substdio_get(&ssin,&ch,1);
 215     if (r == 0) break;
 216     if (r == -1) temp_read();
 217     if (ch == '.')
 218       substdio_put(&smtpto,".",1);
 219     if (flagheader) {
 220       if (ch == '\n') {         /* header ends */
 221         flagheader = 0;
 222         if (!flagdobody) posat = 0;
 223       } else if (ch == '#') {   /* # starting line => VERH ... */
 224         flagdobody = 1;         /* continues in body and ... */
 225         continue;               /* character is suppressed. */
 226       }
 227     }
 228     while (ch != '\n') {
 229       if (ch == '#' && posat) {                 /*   ... # */
 230         r = substdio_get(&ssin,&ch,1);
 231         if (r == 0) perm_partialline();
 232         if (r == -1) temp_read();
 233         if (ch == '#') {                        /*  ... ## */
 234           register char ch1;
 235           ch1 = *substdio_peek(&ssin);
 236           if (ch1 != 'L' && ch1 != 'H') {       /*  ... ##x x!=L x!=H */
 237             substdio_put(&smtpto,"#",1);
 238             continue;
 239           }
 240           r = substdio_get(&ssin,&ch,1);
 241           if (r == 0) perm_partialline();
 242           if (r == -1) temp_read();
 243           if (ch == 'L')                        /* ... ##L */
 244             substdio_put(&smtpto,verh.s,posat);
 245           else                                  /* ... ##H */
 246             substdio_put(&smtpto,verh.s + posat + 1,verh.len - posat - 1);
 247         } else {
 248           substdio_put(&smtpto,"#",1);
 249           if (ch == '\n') break;
 250           substdio_put(&smtpto,&ch,1);
 251         }
 252       } else
 253         substdio_put(&smtpto,&ch,1);
 254       r = substdio_get(&ssin,&ch,1);
 255       if (r == 0) perm_partialline();
 256       if (r == -1) temp_read();
 257     }
 258     substdio_put(&smtpto,"\r\n",2);
 259   }
 260
 261   flagcritical = 1;
 262   substdio_put(&smtpto,".\r\n",3);
 263   substdio_flush(&smtpto);
 264 }
 265
 266 stralloc recip = {0};
 267
 268 void smtp()
 269 {
 270   unsigned long code;
 271   int flagbother;
 272   int i;
 273
 274   if (smtpcode() != 220) quit("ZConnected to "," but greeting failed");
 275
 276   substdio_puts(&smtpto,"HELO ");
 277   substdio_put(&smtpto,helohost.s,helohost.len);
 278   substdio_puts(&smtpto,"\r\n");
 279   substdio_flush(&smtpto);
 280   if (smtpcode() != 250) quit("ZConnected to "," but my name was rejected");
 281
 282   substdio_puts(&smtpto,"MAIL FROM:<");
 283   substdio_put(&smtpto,sender.s,sender.len);
 284   substdio_puts(&smtpto,">\r\n");
 285   substdio_flush(&smtpto);
 286   code = smtpcode();
 287   if (code >= 500) quit("DConnected to "," but sender was rejected");
 288   if (code >= 400) quit("ZConnected to "," but sender was rejected");
 289
 290   flagbother = 0;
 291   for (i = 0;i < reciplist.len;++i) {
 292     substdio_puts(&smtpto,"RCPT TO:<");
 293     substdio_put(&smtpto,reciplist.sa[i].s,reciplist.sa[i].len);
 294     substdio_puts(&smtpto,">\r\n");
 295     substdio_flush(&smtpto);
 296     code = smtpcode();
 297     if (code >= 500) {
 298       out("h"); outhost(); out(" does not like recipient.\n");
 299       outsmtptext(); zero();
 300     }
 301     else if (code >= 400) {
 302       out("s"); outhost(); out(" does not like recipient.\n");
 303       outsmtptext(); zero();
 304     }
 305     else {
 306       out("r"); zero();
 307       flagbother = 1;
 308     }
 309   }
 310   if (!flagbother) quit("DGiving up on ","");
 311
 312   substdio_putsflush(&smtpto,"DATA\r\n");
 313   code = smtpcode();
 314   if (code >= 500) quit("D"," failed on DATA command");
 315   if (code >= 400) quit("Z"," failed on DATA command");
 316
 317   blast();
 318   code = smtpcode();
 319   flagcritical = 0;
 320   if (code >= 500) quit("D"," failed after I sent the message");
 321   if (code >= 400) quit("Z"," failed after I sent the message");
 322   quit("K"," accepted message");
 323 }
 324
 325 stralloc canonhost = {0};
 326 stralloc canonbox = {0};
 327
 328 void addrmangle(saout,s,flagalias,flagcname)
 329 stralloc *saout; /* host has to be canonical, box has to be quoted */
 330 char *s;
 331 int *flagalias;
 332 int flagcname;
 333 {
 334   int j;
 335
 336   *flagalias = flagcname;
 337
 338   j = str_rchr(s,'@');
 339   if (!s[j]) {
 340     if (!stralloc_copys(saout,s)) temp_nomem();
 341     return;
 342   }
 343   if (!stralloc_copys(&canonbox,s)) temp_nomem();
 344   canonbox.len = j;
 345   if (!quote(saout,&canonbox)) temp_nomem();
 346   if (!stralloc_cats(saout,"@")) temp_nomem();
 347
 348   if (!stralloc_copys(&canonhost,s + j + 1)) temp_nomem();
 349   if (flagcname)
 350     switch(dns_cname(&canonhost)) {
 351       case 0: *flagalias = 0; break;
 352       case DNS_MEM: temp_nomem();
 353       case DNS_SOFT: temp_dnscanon();
 354       case DNS_HARD: ; /* alias loop, not our problem */
 355     }
 356
 357   if (!stralloc_cat(saout,&canonhost)) temp_nomem();
 358 }
 359
 360 void getcontrols()
 361 {
 362   if (control_init() == -1) temp_control();
 363   if (control_readint(&timeout,"control/timeoutremote") == -1) temp_control();
 364   if (control_readint(&timeoutconnect,"control/timeoutconnect") == -1)
 365     temp_control();
 366   if (control_rldef(&helohost,"control/helohost",1,(char *) 0) != 1)
 367     temp_control();
 368   switch(control_readfile(&routes,"control/smtproutes",0)) {
 369     case -1:
 370       temp_control();
 371     case 0:
 372       if (!constmap_init(&maproutes,"",0,1)) temp_nomem(); break;
 373     case 1:
 374       if (!constmap_init(&maproutes,routes.s,routes.len,1)) temp_nomem(); break;
 375   }
 376 }
 377
 378 void main(argc,argv)
 379 int argc;
 380 char **argv;
 381 {
 382   static ipalloc ip = {0};
 383   int i;
 384   unsigned long random;
 385   char **recips;
 386   unsigned long prefme;
 387   int flagallaliases;
 388   int flagalias;
 389   char *relayhost;
 390
 391   sig_pipeignore();
 392   if (argc < 4) perm_usage();
 393   flagverh = argc;
 394   vp = argv[3];
 395   if (chdir(auto_qmail) == -1) temp_chdir();
 396   getcontrols();
 397
 398
 399   if (!stralloc_copys(&host,argv[1])) temp_nomem();
 400
 401   relayhost = 0;
 402   for (i = 0;i <= host.len;++i)
 403     if ((i == 0) || (i == host.len) || (host.s[i] == '.'))
 404       if (relayhost = constmap(&maproutes,host.s + i,host.len - i))
 405         break;
 406   if (relayhost && !*relayhost) relayhost = 0;
 407
 408   if (relayhost) {
 409     i = str_chr(relayhost,':');
 410     if (relayhost[i]) {
 411       scan_ulong(relayhost + i + 1,&port);
 412       relayhost[i] = 0;
 413     }
 414     if (!stralloc_copys(&host,relayhost)) temp_nomem();
 415   }
 416
 417
 418   addrmangle(&sender,argv[2],&flagalias,0);
 419
 420   if (!saa_readyplus(&reciplist,0)) temp_nomem();
 421   if (ipme_init() != 1) temp_oserr();
 422
 423   flagallaliases = 1;
 424   recips = argv + 3;
 425   while (*recips) {
 426     if (!saa_readyplus(&reciplist,1)) temp_nomem();
 427     reciplist.sa[reciplist.len] = sauninit;
 428     addrmangle(reciplist.sa + reciplist.len,*recips,&flagalias,!relayhost);
 429     if (!flagalias) flagallaliases = 0;
 430     ++reciplist.len;
 431     ++recips;
 432   }
 433
 434
 435   random = now() + (getpid() << 16);
 436   switch (relayhost ? dns_ip(&ip,&host) : dns_mxip(&ip,&host,random)) {
 437     case DNS_MEM: temp_nomem();
 438     case DNS_SOFT: temp_dns();
 439     case DNS_HARD: perm_dns();
 440     case 1:
 441       if (ip.len <= 0) temp_dns();
 442   }
 443
 444   if (ip.len <= 0) perm_nomx();
 445
 446   prefme = 100000;
 447   for (i = 0;i < ip.len;++i)
 448     if (ipme_is(&ip.ix[i].ip))
 449       if (ip.ix[i].pref < prefme)
 450         prefme = ip.ix[i].pref;
 451
 452   if (relayhost) prefme = 300000;
 453   if (flagallaliases) prefme = 500000;
 454
 455   for (i = 0;i < ip.len;++i)
 456     if (ip.ix[i].pref < prefme)
 457       break;
 458
 459   if (i >= ip.len)
 460     perm_ambigmx();
 461
 462   for (i = 0;i < ip.len;++i) if (ip.ix[i].pref < prefme) {
 463     if (tcpto(&ip.ix[i].ip)) continue;
 464
 465     smtpfd = socket(AF_INET,SOCK_STREAM,0);
 466     if (smtpfd == -1) temp_oserr();
 467
 468     if (timeoutconn(smtpfd,&ip.ix[i].ip,(unsigned int) port,timeoutconnect) == 0) {
 469       tcpto_err(&ip.ix[i].ip,0);
 470       partner = ip.ix[i].ip;
 471       smtp(); /* does not return */
 472     }
 473     tcpto_err(&ip.ix[i].ip,errno == error_timeout);
 474     close(smtpfd);
 475   }
 476
 477   temp_noconn();
 478 }