imapd.c

广泛使用的邮件服务器！同时

				/* subscribe to mailbox */
	else if (!(anonymous || strcmp (cmd,"SUBSCRIBE"))) {
				/* get <mailbox> or MAILBOX <mailbox> */
	  if (!(s = snarf (&arg))) response = misarg;
	  else if (arg) {	/* IMAP2bis form */
	    if (compare_cstring (s,"MAILBOX")) response = badarg;
	    else if (!(s = snarf (&arg))) response = misarg;
	    else if (arg) response = badarg;
	    else mail_subscribe (NIL,s);
	  }
	  else if (isnewsproxy (s)) newsrc_update (NIL,s+6,':');
	  else mail_subscribe (NIL,s);
	  if (stream)		/* allow untagged EXPUNGE */
	    mail_parameters (stream,SET_ONETIMEEXPUNGEATPING,(void *) stream);
	}
				/* unsubscribe to mailbox */
	else if (!(anonymous || strcmp (cmd,"UNSUBSCRIBE"))) {
				/* get <mailbox> or MAILBOX <mailbox> */
	  if (!(s = snarf (&arg))) response = misarg;
	  else if (arg) {	/* IMAP2bis form */
	    if (compare_cstring (s,"MAILBOX")) response = badarg;
	    else if (!(s = snarf (&arg))) response = misarg;
	    else if (arg) response = badarg;
	    else if (isnewsproxy (s)) newsrc_update (NIL,s+6,'!');
	    else mail_unsubscribe (NIL,s);
	  }
	  else mail_unsubscribe (NIL,s);
	  if (stream)		/* allow untagged EXPUNGE */
	    mail_parameters (stream,SET_ONETIMEEXPUNGEATPING,(void *) stream);
	}

	else if (!strcmp (cmd,"NAMESPACE")) {
	  if (arg) response = badarg;
	  else {
	    NAMESPACE **ns = (NAMESPACE **) mail_parameters(NIL,GET_NAMESPACE,
							     NIL);
	    NAMESPACE *n;
	    PARAMETER *p;
	    PSOUT ("* NAMESPACE");
	    if (ns) for (i = 0; i < 3; i++) {
	      if (n = ns[i]) {
		PSOUT (" (");
		do {
		  PBOUT ('(');
		  pstring (n->name);
		  switch (n->delimiter) {
		  case '\\':	/* quoted delimiter */
		  case '"':
		    PSOUT (" \"\\\\\"");
		    break;
		  case '\0':	/* no delimiter */
		    PSOUT (" NIL");
		    break;
		  default:	/* unquoted delimiter */
		    PSOUT (" \"");
		    PBOUT (n->delimiter);
		    PBOUT ('"');
		    break;
		  }
				/* NAMESPACE extensions are hairy */
		  if (p = n->param) do {
		    PBOUT (' ');
		    pstring (p->attribute);
		    PSOUT (" (");
		    do pstring (p->value);
		    while (p->next && !p->next->attribute && (p = p->next));
		    PBOUT (')');
		  } while (p = p->next);
		  PBOUT (')');
		} while (n = n->next);
		PBOUT (')');
	      }
	      else PSOUT (" NIL");
	    }
	    else PSOUT (" NIL NIL NIL");
	    CRLF;
	  }
	  if (stream)		/* allow untagged EXPUNGE */
	    mail_parameters (stream,SET_ONETIMEEXPUNGEATPING,(void *) stream);
	}

				/* create mailbox */
	else if (!(anonymous || strcmp (cmd,"CREATE"))) {
	  if (!(s = snarf (&arg))) response = misarg;
	  else if (arg) response = badarg;
	  else mail_create (NIL,s);
	  if (stream)		/* allow untagged EXPUNGE */
	    mail_parameters (stream,SET_ONETIMEEXPUNGEATPING,(void *) stream);
	}
				/* delete mailbox */
	else if (!(anonymous || strcmp (cmd,"DELETE"))) {
	  if (!(s = snarf (&arg))) response = misarg;
	  else if (arg) response = badarg;
	  else {		/* make sure not selected */
	    if (lastsel && (!strcmp (s,lastsel) ||
			    (stream && !strcmp (s,stream->mailbox))))
	      mm_log ("Can not DELETE the selected mailbox",ERROR);
	    else mail_delete (NIL,s);
	  }
	  if (stream)		/* allow untagged EXPUNGE */
	    mail_parameters (stream,SET_ONETIMEEXPUNGEATPING,(void *) stream);
	}
				/* rename mailbox */
	else if (!(anonymous || strcmp (cmd,"RENAME"))) {
	  if (!((s = snarf (&arg)) && (t = snarf (&arg)))) response = misarg;
	  else if (arg) response = badarg;
	  else {		/* make sure not selected */
	    if (!compare_cstring (s,"INBOX")) s = "INBOX";
	    else if (!compare_cstring (s,"#MHINBOX")) s = "#MHINBOX";
	    if (lastsel && (!strcmp (s,lastsel) ||
			    (stream && !strcmp (s,stream->mailbox))))
	      mm_log ("Can not RENAME the selected mailbox",ERROR);
	    else mail_rename (NIL,s,t);
	  }
	  if (stream)		/* allow untagged EXPUNGE */
	    mail_parameters (stream,SET_ONETIMEEXPUNGEATPING,(void *) stream);
	}

				/* idle mode */
	else if (!strcmp (cmd,"IDLE")) {
				/* no arguments */
	  if (arg) response = badarg;
	  else {		/* tell client ready for argument */
	    unsigned long donefake = 0;
	    PSOUT ("+ Waiting for DONE\015\012");
	    PFLUSH ();		/* dump output buffer */
				/* inactivity countdown */
	    i = ((TIMEOUT) / (IDLETIMER)) + 1;
	    do {		/* main idle loop */
	      if (!donefake) {	/* don't ping mailbox if faking */
		mail_parameters (stream,SET_ONETIMEEXPUNGEATPING,
				 (void *) stream);
		ping_mailbox (uid);
				/* maybe do a checkpoint if not anonymous */
		if (!anonymous && stream && (time (0) > lastcheck + CHECKTIMER)) {
		  mail_check (stream);
				/* cancel likely altwin from mail_check() */
		  if (lsterr) fs_give ((void **) &lsterr);
		  if (lstwrn) fs_give ((void **) &lstwrn);
				/* remember last checkpoint */
		  lastcheck = time (0);
		}
	      }
	      if (lstwrn) {	/* have a warning? */
		PSOUT ("* NO ");
		PSOUT (lstwrn);
		CRLF;
		fs_give ((void **) &lstwrn);
	      }
	      if (!(i % 2)) {	/* prevent NAT timeouts */
		sprintf (tmp,"* OK Timeout in %lu minutes\015\012",
			 (i * IDLETIMER) / 60);
		PSOUT (tmp);
	      }
				/* two minutes before the end... */
	      if ((state == OPEN) && (i <= 2)) {
		sprintf (tmp,"* %lu EXISTS\015\012* %lu RECENT\015\012",
			 donefake = nmsgs + 1,recent + 1);
		PSOUT (tmp);	/* prod client to wake up */
	      }
	      PFLUSH ();	/* dump output buffer */
	    } while ((state != LOGOUT) && !INWAIT (IDLETIMER) && --i);

				/* time to exit idle loop */
	    if (state != LOGOUT) {
	      if (i) {		/* still have time left? */
				/* yes, read expected DONE */
		slurp (tmp,MAILTMPLEN,INPUTTIMEOUT);
		if (((tmp[0] != 'D') && (tmp[0] != 'd')) ||
		    ((tmp[1] != 'O') && (tmp[1] != 'o')) ||
		    ((tmp[2] != 'N') && (tmp[2] != 'n')) ||
		    ((tmp[3] != 'E') && (tmp[3] != 'e')) ||
		    (((tmp[4] != '\015') || (tmp[5] != '\012')) &&
		     (tmp[4] != '\012')))
		  response = "%.80s BAD Bogus IDLE continuation\015\012";
		if (donefake) {	/* if faking at the end */
				/* send EXPUNGE (should be just 1) */
		  while (donefake > nmsgs) {
		    sprintf (tmp,"* %lu EXPUNGE\015\012",donefake--);
		    PSOUT (tmp);
		  }
		  sprintf (tmp,"* %lu EXISTS\015\012* %lu RECENT\015\012",
			   nmsgs,recent);
		  PSOUT (tmp);
		}
	      }
	      else clkint ();	/* otherwise do autologout action */
	    }
	  }
	}
	else response = badcmd;
	break;
      default:
        response = "%.80s BAD Unknown state for %.80s command\015\012";
	break;
      }

      while (litplus.ok) {	/* any unread LITERAL+? */
	litplus.ok = NIL;	/* yes, cancel it now */
	clearerr (stdin);	/* clear stdin errors */
	status = "discarding unread literal";
				/* read literal and discard it */
	while (i = (litplus.size > MAILTMPLEN) ? MAILTMPLEN : litplus.size) {
	  if (state == LOGOUT) litplus.size = 0;
	  else {
	    settimeout (INPUTTIMEOUT);
	    if (PSINR (tmp,i)) litplus.size -= i;
	    else {
	      ioerror (stdin,status);
	      litplus.size = 0;	/* in case it continues */
	    }
	  }
	}
	settimeout (0);		/* stop timeout */
				/* get new command tail */
	slurp (tmp,MAILTMPLEN,INPUTTIMEOUT);
				/* locate end of line */
	if (t = strchr (tmp,'\012')) {
				/* back over CR */
	  if ((t > tmp) && (t[-1] == '\015')) --t;
	  *t = NIL;		/* tie off CRLF */
				/* possible LITERAL+? */
	  if (((i = strlen (tmp)) > 3) && (tmp[i - 1] == '}') &&
	      (tmp[i - 2] == '+') && isdigit (tmp[i - 3])) {
				/* back over possible count */
	    for (i -= 4; i && isdigit (tmp[i]); i--);
	    if (tmp[i] == '{') {	/* found a literal? */
	      litplus.ok = T;	/* yes, note LITERAL+ in effect, set size */
	      litplus.size = strtoul (tmp + i + 1,NIL,10);
	    }
	  }
	}
	else flush ();		/* overlong line after LITERAL+, punt */
      }
      ping_mailbox (uid);	/* update mailbox status before response */
      if (lstwrn && lsterr) {	/* output most recent warning */
	PSOUT ("* NO ");
	PSOUT (lstwrn);
	CRLF;
	fs_give ((void **) &lstwrn);
      }

      if (response == logwin) {	/* authentication win message */
	sprintf (tmp,response,lstref ? "*" : tag);
	PSOUT (tmp);		/* start response */
	pcapability (1);	/* print logged-in capabilities */
	PSOUT ("] User ");
	PSOUT (user);
	PSOUT (" authenticated\015\012");
	if (lstref) {
	  sprintf (tmp,response,tag);
	  PSOUT (tmp);		/* start response */
	  PSOUT ("[REFERRAL ");
	  PSOUT (lstref);
	  PSOUT ("] ");
	  PSOUT (lasterror ());
	  CRLF;
	}
      }
      else if ((response == win) || (response == lose)) {
	sprintf (tmp,response,tag);
	PSOUT (tmp);
	if (cauidvalidity) {	/* COPYUID/APPENDUID response? */
	  sprintf (tmp,"[%.80sUID %lu ",(char *)
		   ((s = strchr (cmd,' ')) ? s+1 : cmd),cauidvalidity);
	  PSOUT (tmp);
	  cauidvalidity = 0;	/* cancel response for future */
	  if (csset) {
	    pset (&csset);
	    PBOUT (' ');
	  }
	  pset (&caset);
	  PSOUT ("] ");
	}
	else if (lstref) {	/* have a referral? */
	  PSOUT ("[REFERRAL ");
	  PSOUT (lstref);
	  PSOUT ("] ");
	}
	if (lsterr || lstwrn) PSOUT (lasterror ());
	else {
	  PSOUT (cmd);
	  PSOUT ((response == win) ? " completed" : "failed");
	}
	CRLF;
      }
      else {			/* normal response */
	if ((response == rowin) || (response == rwwin)) {
	  if (lstwrn) {		/* output most recent warning */
	    PSOUT ("* NO ");
	    PSOUT (lstwrn);
	    CRLF;
	    fs_give ((void **) &lstwrn);
	  }
	}
	sprintf (tmp,response,tag,cmd,lasterror ());
	PSOUT (tmp);		/* output response */
      }
    }
    PFLUSH ();			/* make sure output blatted */

    if (autologouttime) {	/* have an autologout in effect? */
				/* cancel if no longer waiting for login */
      if (state != LOGIN) autologouttime = 0;
				/* took too long to login */
      else if (autologouttime < time (0)) {
	logout = goodbye = "Autologout";
	stream = NIL;
	state = LOGOUT;		/* sayonara */
      }
    }
  }
  if (goodbye && !quell_events){/* have a goodbye message? */
    PSOUT ("* BYE ");		/* utter it */
    PSOUT (goodbye);
    CRLF;
    PFLUSH ();			/* make sure blatted */
  }
  syslog (LOG_INFO,"%s user=%.80s host=%.80s",logout,
	  user ? (char *) user : "???",tcp_clienthost ());
				/* do logout hook if needed */
  if (lgoh = (logouthook_t) mail_parameters (NIL,GET_LOGOUTHOOK,NIL))
    (*lgoh) (mail_parameters (NIL,GET_LOGOUTDATA,NIL));
  _exit (ret);			/* all done */
  return ret;			/* stupid compilers */
}

/* Ping mailbox during each cycle.  Also check alerts
 * Accepts: last command was UID flag
 */

void ping_mailbox (unsigned long uid)
{
  unsigned long i;
  char tmp[MAILTMPLEN];
  if (state == OPEN) {
    if (!mail_ping (stream)) {	/* make sure stream still alive */
      PSOUT ("* BYE ");
      PSOUT (mylocalhost ());
      PSOUT (" Fatal mailbox error: ");
      PSOUT (lasterror ());
      CRLF;
      stream = NIL;		/* don't try to clean up stream */
      state = LOGOUT;		/* go away */
      syslog (LOG_INFO,
	      "Fatal mailbox error user=%.80s host=%.80s mbx=%.80s: %.80s",
	      user ? (char *) user : "???",tcp_clienthost (),
	      (stream && stream->mailbox) ? stream->mailbox : "???",
	      lasterror ());
      return;
    }
				/* change in number of messages? */
    if (existsquelled || (nmsgs != stream->nmsgs)) {
      PSOUT ("* ");
      pnum (nmsgs = stream->nmsgs);
      PSOUT (" EXISTS\015\012");
    }
				/* change in recent messages? */
    if (existsquelled || (recent != stream->recent)) {
      PSOUT ("* ");
      pnum (recent = stream->recent);
      PSOUT (" RECENT\015\012");
    }
    existsquelled = NIL;	/* don't do this until asked again */
    if (stream->uid_validity && (stream->uid_validity != uidvalidity)) {
      PSOUT ("* OK [UIDVALIDITY ");
      pnum (stream->uid_validity);
      PSOUT ("] UID validity status\015\012* OK [UIDNEXT ");
      pnum (stream->uid_last + 1);
      PSOUT ("] Predicted next UID\015\012");
      if (stream->uid_nosticky) {
	PSOUT ("* NO [UIDNOTSTICKY] Non-permanent unique identifiers: ");
	PSOUT (stream->mailbox);
	CRLF;
      }
      uidvalidity = stream->uid_validity;
    }

				/* don't bother if driver changed */
    if (curdriver == stream->dtb) {
				/* first report any new flags */
      if ((nflags < NUSERFLAGS) && stream->user_flags[nflags])
	new_flags (stream);
      for (i = 1; i <= nmsgs; i++) if (mail_elt (stream,i)->spare2) {
	PSOUT ("* ");
	pnum (i);
	PSOUT (" FETCH (");
	fetch_flags (i,NIL);	/* output changed flags */
	if (uid) {		/* need to include UIDs in response? */
	  PBOUT (' ');
	  fetch_uid (i,NIL);
	}