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 void blast()
 193 {
 194   int r;
 195   char ch;
 196
 197   for (;;) {
 198     r = substdio_get(&ssin,&ch,1);
 199     if (r == 0) break;
 200     if (r == -1) temp_read();
 201     if (ch == '.')
 202       substdio_put(&smtpto,".",1);
 203     while (ch != '\n') {
 204       substdio_put(&smtpto,&ch,1);
 205       r = substdio_get(&ssin,&ch,1);
 206       if (r == 0) perm_partialline();
 207       if (r == -1) temp_read();
 208     }
 209     substdio_put(&smtpto,"\r\n",2);
 210   }
 211
 212   flagcritical = 1;
 213   substdio_put(&smtpto,".\r\n",3);
 214   substdio_flush(&smtpto);
 215 }
 216
 217 stralloc recip = {0};
 218
 219 void smtp()
 220 {
 221   unsigned long code;
 222   int flagbother;
 223   int i;
 224
 225   if (smtpcode() != 220) quit("ZConnected to "," but greeting failed");
 226
 227   substdio_puts(&smtpto,"HELO ");
 228   substdio_put(&smtpto,helohost.s,helohost.len);
 229   substdio_puts(&smtpto,"\r\n");
 230   substdio_flush(&smtpto);
 231   if (smtpcode() != 250) quit("ZConnected to "," but my name was rejected");
 232
 233   substdio_puts(&smtpto,"MAIL FROM:<");
 234   substdio_put(&smtpto,sender.s,sender.len);
 235   substdio_puts(&smtpto,">\r\n");
 236   substdio_flush(&smtpto);
 237   code = smtpcode();
 238   if (code >= 500) quit("DConnected to "," but sender was rejected");
 239   if (code >= 400) quit("ZConnected to "," but sender was rejected");
 240
 241   flagbother = 0;
 242   for (i = 0;i < reciplist.len;++i) {
 243     substdio_puts(&smtpto,"RCPT TO:<");
 244     substdio_put(&smtpto,reciplist.sa[i].s,reciplist.sa[i].len);
 245     substdio_puts(&smtpto,">\r\n");
 246     substdio_flush(&smtpto);
 247     code = smtpcode();
 248     if (code >= 500) {
 249       out("h"); outhost(); out(" does not like recipient.\n");
 250       outsmtptext(); zero();
 251     }
 252     else if (code >= 400) {
 253       out("s"); outhost(); out(" does not like recipient.\n");
 254       outsmtptext(); zero();
 255     }
 256     else {
 257       out("r"); zero();
 258       flagbother = 1;
 259     }
 260   }
 261   if (!flagbother) quit("DGiving up on ","");
 262
 263   substdio_putsflush(&smtpto,"DATA\r\n");
 264   code = smtpcode();
 265   if (code >= 500) quit("D"," failed on DATA command");
 266   if (code >= 400) quit("Z"," failed on DATA command");
 267
 268   blast();
 269   code = smtpcode();
 270   flagcritical = 0;
 271   if (code >= 500) quit("D"," failed after I sent the message");
 272   if (code >= 400) quit("Z"," failed after I sent the message");
 273   quit("K"," accepted message");
 274 }
 275
 276 stralloc canonhost = {0};
 277 stralloc canonbox = {0};
 278
 279 void addrmangle(saout,s,flagalias,flagcname)
 280 stralloc *saout; /* host has to be canonical, box has to be quoted */
 281 char *s;
 282 int *flagalias;
 283 int flagcname;
 284 {
 285   int j;
 286
 287   *flagalias = flagcname;
 288
 289   j = str_rchr(s,'@');
 290   if (!s[j]) {
 291     if (!stralloc_copys(saout,s)) temp_nomem();
 292     return;
 293   }
 294   if (!stralloc_copys(&canonbox,s)) temp_nomem();
 295   canonbox.len = j;
 296   if (!quote(saout,&canonbox)) temp_nomem();
 297   if (!stralloc_cats(saout,"@")) temp_nomem();
 298
 299   if (!stralloc_copys(&canonhost,s + j + 1)) temp_nomem();
 300   if (flagcname)
 301     switch(dns_cname(&canonhost)) {
 302       case 0: *flagalias = 0; break;
 303       case DNS_MEM: temp_nomem();
 304       case DNS_SOFT: temp_dnscanon();
 305       case DNS_HARD: ; /* alias loop, not our problem */
 306     }
 307
 308   if (!stralloc_cat(saout,&canonhost)) temp_nomem();
 309 }
 310
 311 void getcontrols()
 312 {
 313   if (control_init() == -1) temp_control();
 314   if (control_readint(&timeout,"control/timeoutremote") == -1) temp_control();
 315   if (control_readint(&timeoutconnect,"control/timeoutconnect") == -1)
 316     temp_control();
 317   if (control_rldef(&helohost,"control/helohost",1,(char *) 0) != 1)
 318     temp_control();
 319   switch(control_readfile(&routes,"control/smtproutes",0)) {
 320     case -1:
 321       temp_control();
 322     case 0:
 323       if (!constmap_init(&maproutes,"",0,1)) temp_nomem(); break;
 324     case 1:
 325       if (!constmap_init(&maproutes,routes.s,routes.len,1)) temp_nomem(); break;
 326   }
 327 }
 328
 329 void main(argc,argv)
 330 int argc;
 331 char **argv;
 332 {
 333   static ipalloc ip = {0};
 334   int i;
 335   unsigned long random;
 336   char **recips;
 337   unsigned long prefme;
 338   int flagallaliases;
 339   int flagalias;
 340   char *relayhost;
 341
 342   sig_pipeignore();
 343   if (argc < 4) perm_usage();
 344   if (chdir(auto_qmail) == -1) temp_chdir();
 345   getcontrols();
 346
 347
 348   if (!stralloc_copys(&host,argv[1])) temp_nomem();
 349
 350   relayhost = 0;
 351   for (i = 0;i <= host.len;++i)
 352     if ((i == 0) || (i == host.len) || (host.s[i] == '.'))
 353       if (relayhost = constmap(&maproutes,host.s + i,host.len - i))
 354         break;
 355   if (relayhost && !*relayhost) relayhost = 0;
 356
 357   if (relayhost) {
 358     i = str_chr(relayhost,':');
 359     if (relayhost[i]) {
 360       scan_ulong(relayhost + i + 1,&port);
 361       relayhost[i] = 0;
 362     }
 363     if (!stralloc_copys(&host,relayhost)) temp_nomem();
 364   }
 365
 366
 367   addrmangle(&sender,argv[2],&flagalias,0);
 368
 369   if (!saa_readyplus(&reciplist,0)) temp_nomem();
 370   if (ipme_init() != 1) temp_oserr();
 371
 372   flagallaliases = 1;
 373   recips = argv + 3;
 374   while (*recips) {
 375     if (!saa_readyplus(&reciplist,1)) temp_nomem();
 376     reciplist.sa[reciplist.len] = sauninit;
 377     addrmangle(reciplist.sa + reciplist.len,*recips,&flagalias,!relayhost);
 378     if (!flagalias) flagallaliases = 0;
 379     ++reciplist.len;
 380     ++recips;
 381   }
 382
 383
 384   random = now() + (getpid() << 16);
 385   switch (relayhost ? dns_ip(&ip,&host) : dns_mxip(&ip,&host,random)) {
 386     case DNS_MEM: temp_nomem();
 387     case DNS_SOFT: temp_dns();
 388     case DNS_HARD: perm_dns();
 389     case 1:
 390       if (ip.len <= 0) temp_dns();
 391   }
 392
 393   if (ip.len <= 0) perm_nomx();
 394
 395   prefme = 100000;
 396   for (i = 0;i < ip.len;++i)
 397     if (ipme_is(&ip.ix[i].ip))
 398       if (ip.ix[i].pref < prefme)
 399         prefme = ip.ix[i].pref;
 400
 401   if (relayhost) prefme = 300000;
 402   if (flagallaliases) prefme = 500000;
 403
 404   for (i = 0;i < ip.len;++i)
 405     if (ip.ix[i].pref < prefme)
 406       break;
 407
 408   if (i >= ip.len)
 409     perm_ambigmx();
 410
 411   for (i = 0;i < ip.len;++i) if (ip.ix[i].pref < prefme) {
 412     if (tcpto(&ip.ix[i].ip)) continue;
 413
 414     smtpfd = socket(AF_INET,SOCK_STREAM,0);
 415     if (smtpfd == -1) temp_oserr();
 416
 417     if (timeoutconn(smtpfd,&ip.ix[i].ip,(unsigned int) port,timeoutconnect) == 0) {
 418       tcpto_err(&ip.ix[i].ip,0);
 419       partner = ip.ix[i].ip;
 420       smtp(); /* does not return */
 421     }
 422     tcpto_err(&ip.ix[i].ip,errno == error_timeout);
 423     close(smtpfd);
 424   }
 425
 426   temp_noconn();
 427 }