#include <sys/types.h>

#include <sys/socket.h>

#include <netinet/in.h>

#include <arpa/inet.h>

#include "sig.h"

#include "stralloc.h"

#include "substdio.h"

#include "subfd.h"

#include "scan.h"

#include "case.h"

#include "error.h"

#include "auto_qmail.h"

#include "control.h"

#include "dns.h"

#include "alloc.h"

#include "quote.h"

#include "ip.h"

#include "ipalloc.h"

#include "ipme.h"

#include "gen_alloc.h"

#include "gen_allocdefs.h"

#include "str.h"

#include "now.h"

#include "exit.h"

#include "constmap.h"

#include "tcpto.h"

#include "readwrite.h"

#include "timeoutconn.h"

#include "timeoutread.h"

#include "timeoutwrite.h"

#define HUGESMTPTEXT 5000

#define PORT_SMTP 25 /* silly rabbit, /etc/services is for users */

unsigned long port = PORT_SMTP;

GEN_ALLOC_typedef(saa,stralloc,sa,len,a)

GEN_ALLOC_readyplus(saa,stralloc,sa,len,a,i,n,x,10,saa_readyplus)

static stralloc sauninit = {0};

stralloc helohost = {0};

stralloc routes = {0};

struct constmap maproutes;

stralloc host = {0};

stralloc sender = {0};

saa reciplist = {0};

struct ip_address partner;

void out(s) char *s; { if (substdio_puts(subfdoutsmall,s) == -1) _exit(0); }

void zero() { if (substdio_put(subfdoutsmall,"\0",1) == -1) _exit(0); }

void zerodie() { zero(); substdio_flush(subfdoutsmall); _exit(0); }

void outsafe(sa) stralloc *sa; { int i; char ch;

for (i = 0;i < sa->len;++i) {

ch = sa->s[i]; if (ch < 33) ch = '?'; if (ch > 126) ch = '?';

if (substdio_put(subfdoutsmall,&ch,1) == -1) _exit(0); } }

void temp_nomem() { out("ZOut of memory. (#4.3.0)\n"); zerodie(); }

void temp_oserr() { out("Z\

System resources temporarily unavailable. (#4.3.0)\n"); zerodie(); }

void temp_noconn() { out("Z\

Sorry, I wasn't able to establish an SMTP connection. (#4.4.1)\n"); zerodie(); }

void temp_read() { out("ZUnable to read message. (#4.3.0)\n"); zerodie(); }

void temp_dnscanon() { out("Z\

CNAME lookup failed temporarily. (#4.4.3)\n"); zerodie(); }

void temp_dns() { out("Z\

Sorry, I couldn't find any host by that name. (#4.1.2)\n"); zerodie(); }

void temp_chdir() { out("Z\

Unable to switch to home directory. (#4.3.0)\n"); zerodie(); }

void temp_control() { out("Z\

Unable to read control files. (#4.3.0)\n"); zerodie(); }

void perm_partialline() { out("D\

SMTP cannot transfer messages with partial final lines. (#5.6.2)\n"); zerodie(); }

void perm_usage() { out("D\

I (qmail-remote) was invoked improperly. (#5.3.5)\n"); zerodie(); }

void perm_dns() { out("D\

Sorry, I couldn't find any host named ");

outsafe(&host);

out(". (#5.1.2)\n"); zerodie(); }

void perm_nomx() { out("D\

Sorry, I couldn't find a mail exchanger or IP address. (#5.4.4)\n");

zerodie(); }

void perm_ambigmx() { out("D\

Sorry. Although I'm listed as a best-preference MX or A for that host,\n\

it isn't in my control/locals file, so I don't treat it as local. (#5.4.6)\n");

zerodie(); }

void outhost()

{

  char x[IPFMT];

  if (substdio_put(subfdoutsmall,x,ip_fmt(x,&partner)) == -1) _exit(0);

}

int flagcritical = 0;

void dropped() {

  out("ZConnected to ");

  outhost();

  out(" but connection died. ");

  if (flagcritical) out("Possible duplicate! ");

  out("(#4.4.2)\n");

  zerodie();

}

int timeoutconnect = 60;

int smtpfd;

int timeout = 1200;

int saferead(fd,buf,len) int fd; char *buf; int len;

{

  int r;

  r = timeoutread(timeout,smtpfd,buf,len);

  if (r <= 0) dropped();

  return r;

}

int safewrite(fd,buf,len) int fd; char *buf; int len;

{

  int r;

  r = timeoutwrite(timeout,smtpfd,buf,len);

  if (r <= 0) dropped();

  return r;

}

char inbuf[1024];

substdio ssin = SUBSTDIO_FDBUF(read,0,inbuf,sizeof inbuf);

char smtptobuf[1024];

substdio smtpto = SUBSTDIO_FDBUF(safewrite,-1,smtptobuf,sizeof smtptobuf);

char smtpfrombuf[128];

substdio smtpfrom = SUBSTDIO_FDBUF(saferead,-1,smtpfrombuf,sizeof smtpfrombuf);

stralloc smtptext = {0};

void get(ch)

char *ch;

{

  substdio_get(&smtpfrom,ch,1);

  if (*ch != '\r')

    if (smtptext.len < HUGESMTPTEXT)

     if (!stralloc_append(&smtptext,ch)) temp_nomem();

}

unsigned long smtpcode()

{

  unsigned char ch;

  unsigned long code;

  if (!stralloc_copys(&smtptext,"")) temp_nomem();

  get(&ch); code = ch - '0';

  get(&ch); code = code * 10 + (ch - '0');

  get(&ch); code = code * 10 + (ch - '0');

  for (;;) {

    get(&ch);

    if (ch != '-') break;

    while (ch != '\n') get(&ch);

    get(&ch);

    get(&ch);

    get(&ch);

  }

  while (ch != '\n') get(&ch);

  return code;

}

void outsmtptext()

{

  int i; 

  if (smtptext.s) if (smtptext.len) {

    out("Remote host said: ");

    for (i = 0;i < smtptext.len;++i)

      if (!smtptext.s[i]) smtptext.s[i] = '?';

    if (substdio_put(subfdoutsmall,smtptext.s,smtptext.len) == -1) _exit(0);

    smtptext.len = 0;

  }

}

void quit(prepend,append)

char *prepend;

char *append;

{

  substdio_putsflush(&smtpto,"QUIT\r\n");

  /* waiting for remote side is just too ridiculous */

  out(prepend);

  outhost();

  out(append);

  out(".\n");

  outsmtptext();

  zerodie();

}

void blast()

{

  int r;

  char ch;

  for (;;) {

    r = substdio_get(&ssin,&ch,1);

    if (r == 0) break;

    if (r == -1) temp_read();

    if (ch == '.')

      substdio_put(&smtpto,".",1);

    while (ch != '\n') {

      substdio_put(&smtpto,&ch,1);

      r = substdio_get(&ssin,&ch,1);

      if (r == 0) perm_partialline();

      if (r == -1) temp_read();

    }

    substdio_put(&smtpto,"\r\n",2);

  }

  flagcritical = 1;

  substdio_put(&smtpto,".\r\n",3);

  substdio_flush(&smtpto);

}

stralloc recip = {0};

void smtp()

{

  unsigned long code;

  int flagbother;

  int i;

  if (smtpcode() != 220) quit("ZConnected to "," but greeting failed");

  substdio_puts(&smtpto,"HELO ");

  substdio_put(&smtpto,helohost.s,helohost.len);

  substdio_puts(&smtpto,"\r\n");

  substdio_flush(&smtpto);

  if (smtpcode() != 250) quit("ZConnected to "," but my name was rejected");

  substdio_puts(&smtpto,"MAIL FROM:<");

  substdio_put(&smtpto,sender.s,sender.len);

  substdio_puts(&smtpto,">\r\n");

  substdio_flush(&smtpto);

  code = smtpcode();

  if (code >= 500) quit("DConnected to "," but sender was rejected");

  if (code >= 400) quit("ZConnected to "," but sender was rejected");

  flagbother = 0;

  for (i = 0;i < reciplist.len;++i) {

    substdio_puts(&smtpto,"RCPT TO:<");

    substdio_put(&smtpto,reciplist.sa[i].s,reciplist.sa[i].len);

    substdio_puts(&smtpto,">\r\n");

    substdio_flush(&smtpto);

    code = smtpcode();

    if (code >= 500) {

      out("h"); outhost(); out(" does not like recipient.\n");

      outsmtptext(); zero();

    }

    else if (code >= 400) {

      out("s"); outhost(); out(" does not like recipient.\n");

      outsmtptext(); zero();

    }

    else {

      out("r"); zero();

      flagbother = 1;

    }

  }

  if (!flagbother) quit("DGiving up on ","");

  substdio_putsflush(&smtpto,"DATA\r\n");

  code = smtpcode();

  if (code >= 500) quit("D"," failed on DATA command");

  if (code >= 400) quit("Z"," failed on DATA command");

  blast();

  code = smtpcode();

  flagcritical = 0;

  if (code >= 500) quit("D"," failed after I sent the message");

  if (code >= 400) quit("Z"," failed after I sent the message");

  quit("K"," accepted message");

}

stralloc canonhost = {0};

stralloc canonbox = {0};

void addrmangle(saout,s,flagalias,flagcname)

stralloc *saout; /* host has to be canonical, box has to be quoted */

char *s;

int *flagalias;

int flagcname;

{

  int j;

  *flagalias = flagcname;

  j = str_rchr(s,'@');

  if (!s[j]) {

    if (!stralloc_copys(saout,s)) temp_nomem();

    return;

  }

  if (!stralloc_copys(&canonbox,s)) temp_nomem();

  canonbox.len = j;

  if (!quote(saout,&canonbox)) temp_nomem();

  if (!stralloc_cats(saout,"@")) temp_nomem();

  if (!stralloc_copys(&canonhost,s + j + 1)) temp_nomem();

  if (flagcname)

    switch(dns_cname(&canonhost)) {

      case 0: *flagalias = 0; break;

      case DNS_MEM: temp_nomem();

      case DNS_SOFT: temp_dnscanon();

      case DNS_HARD: ; /* alias loop, not our problem */

    }

  if (!stralloc_cat(saout,&canonhost)) temp_nomem();

}

void getcontrols()

{

  if (control_init() == -1) temp_control();

  if (control_readint(&timeout,"control/timeoutremote") == -1) temp_control();

  if (control_readint(&timeoutconnect,"control/timeoutconnect") == -1)

    temp_control();

  if (control_rldef(&helohost,"control/helohost",1,(char *) 0) != 1)

    temp_control();

  switch(control_readfile(&routes,"control/smtproutes",0)) {

    case -1:

      temp_control();

    case 0:

      if (!constmap_init(&maproutes,"",0,1)) temp_nomem(); break;

    case 1:

      if (!constmap_init(&maproutes,routes.s,routes.len,1)) temp_nomem(); break;

  }

}

void main(argc,argv)

int argc;

char **argv;

{

  static ipalloc ip = {0};

  int i;

  unsigned long random;

  char **recips;

  unsigned long prefme;

  int flagallaliases;

  int flagalias;

  char *relayhost;

  sig_pipeignore();

  if (argc < 4) perm_usage();

  if (chdir(auto_qmail) == -1) temp_chdir();

  getcontrols();

  if (!stralloc_copys(&host,argv[1])) temp_nomem();

  relayhost = 0;

  for (i = 0;i <= host.len;++i)

    if ((i == 0) || (i == host.len) || (host.s[i] == '.'))

      if (relayhost = constmap(&maproutes,host.s + i,host.len - i))

        break;

  if (relayhost && !*relayhost) relayhost = 0;

  if (relayhost) {

    i = str_chr(relayhost,':');

    if (relayhost[i]) {

      scan_ulong(relayhost + i + 1,&port);

      relayhost[i] = 0;

    }

    if (!stralloc_copys(&host,relayhost)) temp_nomem();

  }

  addrmangle(&sender,argv[2],&flagalias,0);

  if (!saa_readyplus(&reciplist,0)) temp_nomem();

  if (ipme_init() != 1) temp_oserr();

  flagallaliases = 1;

  recips = argv + 3;

  while (*recips) {

    if (!saa_readyplus(&reciplist,1)) temp_nomem();

    reciplist.sa[reciplist.len] = sauninit;

    addrmangle(reciplist.sa + reciplist.len,*recips,&flagalias,!relayhost);

    if (!flagalias) flagallaliases = 0;

    ++reciplist.len;

    ++recips;

  }

  random = now() + (getpid() << 16);

  switch (relayhost ? dns_ip(&ip,&host) : dns_mxip(&ip,&host,random)) {

    case DNS_MEM: temp_nomem();

    case DNS_SOFT: temp_dns();

    case DNS_HARD: perm_dns();

    case 1:

      if (ip.len <= 0) temp_dns();

  }

  if (ip.len <= 0) perm_nomx();

  prefme = 100000;

  for (i = 0;i < ip.len;++i)

    if (ipme_is(&ip.ix[i].ip))

      if (ip.ix[i].pref < prefme)

        prefme = ip.ix[i].pref;

  if (relayhost) prefme = 300000;

  if (flagallaliases) prefme = 500000;

  for (i = 0;i < ip.len;++i)

    if (ip.ix[i].pref < prefme)

      break;

  if (i >= ip.len)

    perm_ambigmx();

  for (i = 0;i < ip.len;++i) if (ip.ix[i].pref < prefme) {

    if (tcpto(&ip.ix[i].ip)) continue;

    smtpfd = socket(AF_INET,SOCK_STREAM,0);

    if (smtpfd == -1) temp_oserr();

    if (timeoutconn(smtpfd,&ip.ix[i].ip,(unsigned int) port,timeoutconnect) == 0) {

      tcpto_err(&ip.ix[i].ip,0);

      partner = ip.ix[i].ip;

      smtp(); /* does not return */

    }

    tcpto_err(&ip.ix[i].ip,errno == error_timeout);

    close(smtpfd);

  }

  temp_noconn();

}