imapd.c

广泛使用的邮件服务器！同时

				/* no more last error or literal */
    if (lstwrn) fs_give ((void **) &lstwrn);
    if (lsterr) fs_give ((void **) &lsterr);
    if (lstref) fs_give ((void **) &lstref);
    while (litsp) fs_give ((void **) &litstk[--litsp]);
				/* find end of line */
    if (!strchr (cmdbuf,'\012')) {
      if (t = strchr (cmdbuf,' ')) *t = '\0';
      if ((t - cmdbuf) > 100) t = NIL;
      flush ();			/* flush excess */
      if (state == LOGIN)	/* error if NLI */
	syslog (LOG_INFO,"Line too long before authentication host=%.80s",
		tcp_clienthost ());
      sprintf (tmp,response,t ? (char *) cmdbuf : "*");
      PSOUT (tmp);
    }
    else if (!(tag = strtok (cmdbuf," \015\012"))) {
      if (state == LOGIN)	/* error if NLI */
	syslog (LOG_INFO,"Null command before authentication host=%.80s",
		tcp_clienthost ());
      PSOUT ("* BAD Null command\015\012");
    }
    else if (strlen (tag) > 50) PSOUT ("* BAD Excessively long tag\015\012");
    else if (!(s = strtok (NIL," \015\012"))) {
      if (state == LOGIN)	/* error if NLI */
	syslog (LOG_INFO,"Missing command before authentication host=%.80s",
		tcp_clienthost ());
      PSOUT (tag);
      PSOUT (" BAD Missing command\015\012");
    }
    else {			/* parse command */
      response = win;		/* set default response */
      finding = NIL;		/* no longer FINDing */
      ucase (s);		/* canonicalize command case */
				/* UID command? */
      if (!strcmp (s,"UID") && strtok (NIL," \015\012")) {
	uid = T;		/* a UID command */
	s[3] = ' ';		/* restore the space delimiter */
	ucase (s);		/* make sure command all uppercase */
      }
      else uid = NIL;		/* not a UID command */
				/* flush previous saved command */
      if (cmd) fs_give ((void **) &cmd);
      cmd = cpystr (s);		/* save current command */
				/* snarf argument, see if possible litplus */
      if ((arg = strtok (NIL,"\015\012")) && ((i = strlen (arg)) > 3) &&
	  (arg[i - 1] == '}') && (arg[i - 2] == '+') && isdigit (arg[i - 3])) {
				/* back over possible count */
	for (i -= 4; i && isdigit (arg[i]); i--);
	if (arg[i] == '{') {	/* found a literal? */
	  litplus.ok = T;	/* yes, note LITERAL+ in effect, set size */
	  litplus.size = strtoul (arg + i + 1,NIL,10);
	}
      }

				/* these commands always valid */
      if (!strcmp (cmd,"NOOP")) {
	if (arg) response = badarg;
	else if (stream)	/* allow untagged EXPUNGE */
	  mail_parameters (stream,SET_ONETIMEEXPUNGEATPING,(void *) stream);
      }
      else if (!strcmp (cmd,"LOGOUT")) {
	if (arg) response = badarg;
	else {			/* time to say farewell */
	  server_init (NIL,NIL,NIL,SIG_IGN,SIG_IGN,SIG_IGN,SIG_IGN,SIG_IGN);
	  if (lastsel) fs_give ((void **) &lastsel);
	  if (state == OPEN) stream = mail_close (stream);
	  state = LOGOUT;
	  PSOUT ("* BYE ");
	  PSOUT (mylocalhost ());
	  PSOUT (" IMAP4rev1 server terminating connection\015\012");
	}
      }
      else if (!strcmp (cmd,"CAPABILITY")) {
	if (arg) response = badarg;
	else {
	  PSOUT ("* ");
	  pcapability (0);	/* print capabilities */
	  CRLF;
	}
	if (stream)		/* allow untagged EXPUNGE */
	  mail_parameters (stream,SET_ONETIMEEXPUNGEATPING,(void *) stream);
      }
#ifdef NETSCAPE_BRAIN_DAMAGE
      else if (!strcmp (cmd,"NETSCAPE")) {
	PSOUT ("* OK [NETSCAPE]\015\012* VERSION 1.0 UNIX\015\012* ACCOUNT-URL \"");
	PSOUT (NETSCAPE_BRAIN_DAMAGE);
	PBOUT ('"');
	CRLF;
      }
#endif

      else switch (state) {	/* dispatch depending upon state */
      case LOGIN:		/* waiting to get logged in */
				/* new style authentication */
	if (!strcmp (cmd,"AUTHENTICATE")) {
	  if (user) fs_give ((void **) &user);
	  if (pass) fs_give ((void **) &pass);
	  initial = NIL;	/* no initial argument */
	  cancelled = NIL;	/* not cancelled */
				/* mandatory first argument */
	  if (!(s = snarf (&arg))) response = misarg;
	  else if (arg && !(initial = snarf_base64 (&arg)))
	    response = misarg;	/* optional second argument */
	  else if (arg) response = badarg;
	  else if (!strcmp (ucase (s),"ANONYMOUS") && !stat (ANOFILE,&sbuf)) {
	    if (!(s = imap_responder ("",0,NIL)))
	      response ="%.80s BAD AUTHENTICATE ANONYMOUS cancelled\015\012";
	    else if (anonymous_login (argc,argv)) {
	      anonymous = T;	/* note we are anonymous */
	      user = cpystr ("ANONYMOUS");
	      pass = cpystr ("*");
	      state = SELECT;	/* make select */
	      alerttime = 0;	/* force alert */
	      response = logwin;/* return logged-in capabilities */
	      syslog (LOG_INFO,"Authenticated anonymous=%.80s host=%.80s",s,
		      tcp_clienthost ());
	      fs_give ((void **) &s);
	    }
	    else response ="%.80s NO AUTHENTICATE ANONYMOUS failed\015\012";
	  }
	  else if (user = cpystr (mail_auth (s,imap_responder,argc,argv))) {
	    pass = cpystr ("*");
	    state = SELECT;	/* make select */
	    alerttime = 0;	/* force alert */
	    response = logwin;	/* return logged-in capabilities */
	    syslog (LOG_INFO,"Authenticated user=%.80s host=%.80s mech=%.80s",
		    user,tcp_clienthost (),s);
	  }

	  else {
	    AUTHENTICATOR *auth = mail_lookup_auth (1);
	    char *msg = (char *) fs_get (strlen (cmd) + strlen (s) + 2);
	    sprintf (msg,"%s %s",cmd,s);
	    fs_give ((void **) &cmd);
	    cmd = msg;
	    for (i = !mail_parameters (NIL,GET_DISABLEPLAINTEXT,NIL);
		 auth && compare_cstring (s,auth->name); auth = auth->next);
	    /* Failed authentication when hidden looks like invalid command.
	     * This is intentional but confused me when I was debugging.
	     */
	    if (auth && auth->server && !(auth->flags & AU_DISABLE) &&
		!(auth->flags & AU_HIDE) && (i || (auth->flags & AU_SECURE))) {
	      response = lose;
	      if (cancelled) {
		if (lsterr) fs_give ((void **) &lsterr);
		lsterr = cpystr ("cancelled by user");
	      }
	      if (!lsterr)	/* catch-all */
		lsterr = cpystr ("Invalid authentication credentials");
	      syslog (LOG_INFO,"AUTHENTICATE %.80s failure host=%.80s",s,
		      tcp_clienthost ());
	    }
	    else {
	      response = badcmd;
	      syslog (LOG_INFO,"AUTHENTICATE %.80s invalid host=%.80s",s,
		      tcp_clienthost ());
	    }
	  }
	}

				/* plaintext login with password */
	else if (!strcmp (cmd,"LOGIN")) {
	  if (user) fs_give ((void **) &user);
	  if (pass) fs_give ((void **) &pass);
				/* two arguments */
	  if (!((user = cpystr (snarf (&arg))) &&
		(pass = cpystr (snarf (&arg))))) response = misarg;
	  else if (arg) response = badarg;
				/* see if we allow anonymous */
	  else if (!compare_cstring (user,"ANONYMOUS") &&
		   !stat (ANOFILE,&sbuf) && anonymous_login (argc,argv)) {
	    anonymous = T;	/* note we are anonymous */
	    ucase (user);	/* make all uppercase for consistency */
	    state = SELECT;	/* make select */
	    alerttime = 0;	/* force alert */
	    response = logwin;	/* return logged-in capabilities */
	    syslog (LOG_INFO,"Login anonymous=%.80s host=%.80s",pass,
		    tcp_clienthost ());
	  }
	  else {		/* delimit user from possible admin */
	    if (s = strchr (user,'*')) *s++ ='\0';
				/* see if username and password are OK */
	    if (server_login (user,pass,s,argc,argv)) {
	      state = SELECT;	/* make select */
	      alerttime = 0;	/* force alert */
	      response = logwin;/* return logged-in capabilities */
	      syslog (LOG_INFO,"Login user=%.80s host=%.80s",user,
		      tcp_clienthost ());
	    }
	    else {
	      response = lose;
	      if (!lsterr) lsterr = cpystr ("Invalid login credentials");
	    }
	  }
	}
				/* start TLS security */
	else if (!strcmp (cmd,"STARTTLS")) {
	  if (arg) response = badarg;
	  else if (lsterr = ssl_start_tls (pgmname)) response = lose;
	}
	else response = badcmd;
	break;

      case OPEN:		/* valid only when mailbox open */
				/* fetch mailbox attributes */
	if (!strcmp (cmd,"FETCH") || !strcmp (cmd,"UID FETCH")) {
	  if (!(arg && (s = strtok (arg," ")) && (t = strtok(NIL,"\015\012"))))
	    response = misarg;
	  else if (uid ? mail_uid_sequence (stream,s) :
		   mail_sequence (stream,s)) fetch (t,uid);
	  else response = badseq;
	}
				/* store mailbox attributes */
	else if (!strcmp (cmd,"STORE") || !strcmp (cmd,"UID STORE")) {
				/* must have three arguments */
	  if (!(arg && (s = strtok (arg," ")) && (v = strtok (NIL," ")) &&
		(t = strtok (NIL,"\015\012")))) response = misarg;
	  else if (!(uid ? mail_uid_sequence (stream,s) :
		     mail_sequence (stream,s))) response = badseq;
	  else {
	    f = ST_SET | (uid ? ST_UID : NIL)|((v[5]&&v[6]) ? ST_SILENT : NIL);
	    if (!strcmp (ucase (v),"FLAGS") || !strcmp (v,"FLAGS.SILENT")) {
	      strcpy (tmp,"\\Answered \\Flagged \\Deleted \\Draft \\Seen");
	      for (i = 0, u = tmp;
		   (i < NUSERFLAGS) && (v = stream->user_flags[i]); i++)
	        if (strlen (v) <
		    ((size_t) (MAILTMPLEN - ((u += strlen (u)) + 2 - tmp)))) {
		  *u++ = ' ';	/* write next flag */
		  strcpy (u,v);
		}
	      mail_flag (stream,s,tmp,f & ~ST_SET);
	    }
	    else if (!strcmp (v,"-FLAGS") || !strcmp (v,"-FLAGS.SILENT"))
	      f &= ~ST_SET;	/* clear flags */
	    else if (strcmp (v,"+FLAGS") && strcmp (v,"+FLAGS.SILENT")) {
	      response = badatt;
	      break;
	    }
				/* find last keyword */
	    for (i = 0; (i < NUSERFLAGS) && stream->user_flags[i]; i++);
	    mail_flag (stream,s,t,f);
				/* any new keywords appeared? */
	    if (i < NUSERFLAGS && stream->user_flags[i]) new_flags (stream);
				/* return flags if silence not wanted */
	    if (uid ? mail_uid_sequence (stream,s) : mail_sequence (stream,s))
	      for (i = 1; i <= nmsgs; i++) if (mail_elt(stream,i)->sequence)
		mail_elt (stream,i)->spare2 = (f & ST_SILENT) ? NIL : T;
	  }
	}

				/* check for new mail */
	else if (!strcmp (cmd,"CHECK")) {
				/* no arguments */
	  if (arg) response = badarg;
	  else if (!anonymous) {
	    mail_check (stream);
				/* remember last check time */
	    lastcheck = time (0);
	  }
	}
				/* expunge deleted messages */
	else if (!(anonymous || (strcmp (cmd,"EXPUNGE") &&
				 strcmp (cmd,"UID EXPUNGE")))) {
	  if (uid && !arg) response = misarg;
	  else if (!uid && arg) response = badarg;
	  else {		/* expunge deleted or specified UIDs */
	    mail_expunge_full (stream,arg,arg ? EX_UID : NIL);
				/* remember last checkpoint */
	    lastcheck = time (0);
	  }
	}
				/* close mailbox */
	else if (!strcmp (cmd,"CLOSE") || !strcmp (cmd,"UNSELECT")) {
				/* no arguments */
	  if (arg) response = badarg;
	  else {
				/* no last uid */
	    uidvalidity = lastuid = 0;
	    if (lastsel) fs_give ((void **) &lastsel);
	    if (lastid) fs_give ((void **) &lastid);
	    if (lastst.data) fs_give ((void **) &lastst.data);
	    stream = mail_close_full (stream,((*cmd == 'C') && !anonymous) ?
				      CL_EXPUNGE : NIL);
	    state = SELECT;	/* no longer opened */
	    lastcheck = 0;	/* no last checkpoint */
	  }
	}
	else if (!anonymous &&	/* copy message(s) */
		 (!strcmp (cmd,"COPY") || !strcmp (cmd,"UID COPY"))) {
	  trycreate = NIL;	/* no trycreate status */
	  if (!(arg && (s = strtok (arg," ")) && (arg = strtok(NIL,"\015\012"))
		&& (t = snarf (&arg)))) response = misarg;
	  else if (arg) response = badarg;
	  else if (!nmsgs) {
	    response = lose;
	    if (!lsterr) lsterr = cpystr ("Mailbox is empty");
	  }
	  else if (!(uid ? mail_uid_sequence (stream,s) :
		     mail_sequence (stream,s))) response = badseq;
				/* try copy */
	  else if (!mail_copy_full (stream,s,t,uid ? CP_UID : NIL)) {
	    response = trycreate ? losetry : lose;
	    if (!lsterr) lsterr = cpystr ("No such destination mailbox");
	  }
	}

				/* sort mailbox */
	else if (!strcmp (cmd,"SORT") || !strcmp (cmd,"UID SORT")) {
				/* must have four arguments */
	  if (!(arg && (*arg == '(') && (t = strchr (s = arg + 1,')')) &&
		(t[1] == ' ') && (*(arg = t + 2)))) response = misarg;
	  else {		/* read criteria */
	    SEARCHPGM *spg = NIL;
	    char *cs = NIL;
	    SORTPGM *pgm = NIL,*pg = NIL;
	    unsigned long *slst,*sl;
	    *t = NIL;		/* tie off criteria list */
	    if (!(s = strtok (ucase (s)," "))) response = badatt;
	    else {
	      do {		/* parse sort attributes */
		if (pg) pg = pg->next = mail_newsortpgm ();
		else pgm = pg = mail_newsortpgm ();
		if (!strcmp (s,"REVERSE")) {
		  pg->reverse = T;
		  if (!(s = strtok (NIL," "))) {
		    s = "";	/* end of attributes */
		    break;
		  }
		}
		if (!strcmp (s,"DATE")) pg->function = SORTDATE;
		else if (!strcmp (s,"ARRIVAL")) pg->function = SORTARRIVAL;
		else if (!strcmp (s,"FROM")) pg->function = SORTFROM;
		else if (!strcmp (s,"SUBJECT")) pg->function = SORTSUBJECT;
		else if (!strcmp (s,"TO")) pg->function = SORTTO;
		else if (!strcmp (s,"CC")) pg->function = SORTCC;
		else if (!strcmp (s,"SIZE")) pg->function = SORTSIZE;
		else break;
	      } while (s = strtok (NIL," "));
				/* bad SORT attribute */
	      if (s) response = badatt;
				/* get charset and search criteria */
	      else if (!((t = snarf (&arg)) && (cs = cpystr (t)) && arg &&
			 *arg)) response = misarg;
				/* parse search criteria  */
	      else if (!parse_criteria (spg = mail_newsearchpgm (),&arg,nmsgs,
					uidmax (stream),0)) response = badatt;
	      else if (arg && *arg) response = badarg;
	      else if (slst = mail_sort (stream,cs,spg,pgm,uid ? SE_UID:NIL)) {
		PSOUT ("* SORT");
		for (sl = slst; *sl; sl++) {
		  PBOUT (' ');
		  pnum (*sl);
		}
		CRLF;
		fs_give ((void **) &slst);
	      }
	    }
	    if (pgm) mail_free_sortpgm (&pgm);
	    if (spg) mail_free_searchpgm (&spg);
	    if (cs) fs_give ((void **) &cs);
	  }
	}

				/* thread mailbox */
	else if (!strcmp (cmd,"THREAD") || !strcmp (cmd,"UID THREAD")) {
	  THREADNODE *thr;
	  SEARCHPGM *spg = NIL;
	  char *cs = NIL;
				/* must have four arguments */
	  if (!(arg && (s = strtok (arg," ")) && (cs = strtok (NIL," ")) &&
		(cs = cpystr (cs)) && (arg = strtok (NIL,"\015\012"))))
	    response = misarg;
	  else if (!parse_criteria (spg = mail_newsearchpgm (),&arg,nmsgs,
				    uidmax (stream),0)) response = badatt;
	  else if (arg && *arg) response = badarg;
	  else {
	    if (thr = mail_thread (stream,s,cs,spg,uid ? SE_UID : NIL)) {
	      PSOUT ("* THREAD ");
	      pthread (thr);
	      mail_free_threadnode (&thr);
	    }
	    else PSOUT ("* THREAD");
	    CRLF;
	  }
	  if (spg) mail_free_searchpgm (&spg);
	  if (cs) fs_give ((void **) &cs);
	}

				/* search mailbox */
        else if (!strcmp (cmd,"SEARCH") || !strcmp (cmd,"UID SEARCH")) {
	  int retval = NIL;