mix.c

广泛使用的邮件服务器！同时

      break;
    MM_NOTIFY (stream,"[TRYCREATE] Must create mailbox before append",NIL);
    break;
  default:
    sprintf (tmp,"Not a MIX-format mailbox: %.80s",mailbox);
    MM_LOG (tmp,ERROR);
    break;
  }

				/* get first message */
  if (ret && MM_APPEND (af) (stream,data,&flags,&date,&message)) {
    MAILSTREAM *astream;
    FILE *idxf = NIL;
    FILE *msgf = NIL;
    FILE *statf = NIL;
    if (ret = ((astream = mail_open (NIL,mailbox,OP_SILENT)) &&
	       !astream->rdonly &&
	       (((MIXLOCAL *) astream->local)->expok = T) &&
	       (statf = mix_parse (astream,&idxf,LONGT,NIL))) ?
	LONGT : NIL) {
      int fd;
      unsigned long size,hdrsize;
      MESSAGECACHE elt;
      MIXLOCAL *local = (MIXLOCAL *) astream->local;
      unsigned long seq = mix_modseq (local->metaseq);
				/* make sure new modseq fits */
      if (local->indexseq > seq) seq = local->indexseq + 1;
      if (local->statusseq > seq) seq = local->statusseq + 1;
				/* calculate size of per-message header */
      sprintf (local->buf,MSRFMT,MSGTOK,0,0,0,0,0,0,0,'+',0,0,0);
      hdrsize = strlen (local->buf);
      MM_CRITICAL (astream);	/* go critical */
      astream->silent = T;	/* no events here */
				/* open data file */
      if (msgf = mix_data_open (astream,&fd,&size,hdrsize + SIZE (message))) {
	appenduid_t au = (appenduid_t) mail_parameters (NIL,GET_APPENDUID,NIL);
	SEARCHSET *dst = au ? mail_newsearchset () : NIL;
	while (ret && message) {/* while good to go and have messages */
	  errno = NIL;		/* in case one of these causes failure */
				/* guard against zero-length */
	  if (!(ret = SIZE (message)))
	    MM_LOG ("Append of zero-length message",ERROR);
	  else if (date && !(ret = mail_parse_date (&elt,date))) {
	    sprintf (tmp,"Bad date in append: %.80s",date);
	    MM_LOG (tmp,ERROR);
	  }
	  else {
	    if (!date) {	/* if date not specified, use now */
	      internal_date (tmp);
	      mail_parse_date (&elt,tmp);
	    }
	    ret = mix_append_msg (astream,msgf,flags,&elt,message,dst,seq) &&
	      MM_APPEND (af) (stream,data,&flags,&date,&message);
	  }
	}

				/* finish write if success */
	if (ret && (ret = !fflush (msgf))) {
	  fclose (msgf);	/* all good, close the msg file now */
				/* write new metadata, index, and status */
	  local->metaseq = local->indexseq = local->statusseq = seq;
	  if ((ret = (mix_meta_update (astream) &&
		      mix_index_update (astream,idxf,LONGT) &&
		      mix_status_update (astream,statf,LONGT))) && au) {
	      (*au) (mailbox,astream->uid_validity,dst);
	      dst = NIL;	/* don't free this set now */
	  }
	}
	else {			/* failure */
	  if (errno) {		/* output error message if system call error */
	    sprintf (tmp,"Message append failed: %.80s",strerror (errno));
	    MM_LOG (tmp,ERROR);
	  }
	  ftruncate (fd,size);	/* revert all writes to file*/
	  close (fd);		/* make sure that fclose doesn't corrupt us */
	  fclose (msgf);	/* free the stdio resources */
	}
				/* flush any set remaining */
	mail_free_searchset (&dst);
      }
      else {			/* message file open failed */
	sprintf (tmp,"Error opening append message file: %.80s",
		 strerror (errno));
	MM_LOG (tmp,ERROR);
	ret = NIL;
      }
      MM_NOCRITICAL (astream);	/* release critical */
    }
    else MM_LOG ("Can't open append mailbox",ERROR);
    if (statf) fclose (statf);	/* close status if still open */
    if (idxf) fclose (idxf);	/* close index if still open */
    if (astream) mail_close (astream);
  }
  return ret;
}

/* MIX mail append single message
 * Accepts: MAIL stream
 *	    flags for new message if non-NIL
 *	    elt with source date if non-NIL
 *	    stringstruct of message text
 *	    searchset to place UID
 *	    modseq of message
 * Returns: T if success, NIL if failure
 */

long mix_append_msg (MAILSTREAM *stream,FILE *f,char *flags,MESSAGECACHE *delt,
		     STRING *msg,SEARCHSET *set,unsigned long seq)
{
  MESSAGECACHE *elt;
  int c,cs;
  unsigned long i,j,k,uf,hoff;
  long sf;
  stream->kwd_create = NIL;	/* don't copy unknown keywords */
  sf = mail_parse_flags (stream,flags,&uf);
				/* swell the cache */
  mail_exists (stream,++stream->nmsgs);
				/* assign new UID from metadata */
  (elt = mail_elt (stream,stream->nmsgs))->private.uid = ++stream->uid_last;
  elt->private.mod = seq;	/* set requested modseq in status */
  elt->rfc822_size = SIZE (msg);/* copy message size and date to index */
  elt->year = delt->year; elt->month = delt->month; elt->day = delt->day;
  elt->hours = delt->hours; elt->minutes = delt->minutes;
  elt->seconds = delt->seconds; elt->zoccident = delt->zoccident;
  elt->zhours = delt->zhours; elt->zminutes = delt->zminutes;
  /*
   * Do NOT set elt->valid here!  mix_status_update() uses it to determine
   * whether a message should be marked as old.
   */
  if (sf&fSEEN) elt->seen = T;	/* copy flags to status */
  if (sf&fDELETED) elt->deleted = T;
  if (sf&fFLAGGED) elt->flagged = T;
  if (sf&fANSWERED) elt->answered = T;
  if (sf&fDRAFT) elt->draft = T;
  elt->user_flags |= uf;
				/* message is in new message file */
  elt->private.spare.data = LOCAL->newmsg;

				/* offset to message internal header */
  elt->private.special.offset = ftell (f);
				/* build header for message */
  fprintf (f,MSRFMT,MSGTOK,elt->private.uid,
	   elt->year + BASEYEAR,elt->month,elt->day,
	   elt->hours,elt->minutes,elt->seconds,
	   elt->zoccident ? '-' : '+',elt->zhours,elt->zminutes,
	   elt->rfc822_size);
				/* offset to header from  internal header */
  elt->private.msg.header.offset = ftell (f) - elt->private.special.offset;
  for (cs = 0; SIZE (msg); ) {	/* copy message */
    if (elt->private.msg.header.text.size) {
      if (msg->cursize)		/* blat entire chunk if have it */
	for (j = msg->cursize; j; j -= k)
	  if (!(k = fwrite (msg->curpos,1,j,f))) return NIL;
      SETPOS (msg,GETPOS (msg) + msg->cursize);
    }
    else {			/* still searching for delimiter */
      c = 0xff & SNX (msg);	/* get source character */
      if (putc (c,f) == EOF) return NIL;
      switch (cs) {		/* decide what to do based on state */
      case 0:			/* previous char ordinary */
	if (c == '\015') cs = 1;/* advance if CR */
	break;
      case 1:			/* previous CR, advance if LF */
	cs = (c == '\012') ? 2 : 0;
	break;
      case 2:			/* previous CRLF, advance if CR */
	cs = (c == '\015') ? 3 : 0;
	break;
      case 3:			/* previous CRLFCR, done if LF */
	if (c == '\012') elt->private.msg.header.text.size =
			   elt->rfc822_size - SIZE (msg);
	cs = 0;			/* reset mechanism */
	break;
      }
    }
  }
				/* if no delimiter, header is entire msg */
  if (!elt->private.msg.header.text.size)
    elt->private.msg.header.text.size = elt->rfc822_size;
				/* add this message to set */
  mail_append_set (set,elt->private.uid);
  return LONGT;			/* success */
}

/* MIX mail read metadata, index, and status
 * Accepts: MAIL stream
 *	    returned index file
 *	    index file flags (non-NIL if want to add/remove messages)
 *	    status file flags (non-NIL if want to update elt->valid and old)
 * Returns: open status file, or NIL if failure
 *
 * Note that this routine can return an open index file even if it fails!
 */

static char *shortmsg =
  "message %lu (UID=%.08lx) truncated by %lu byte(s) (%lu < %lu)";

FILE *mix_parse (MAILSTREAM *stream,FILE **idxf,long iflags,long sflags)
{
  int fd;
  unsigned long i;
  char *s,*t;
  struct stat sbuf;
  FILE *statf = NIL;
  short metarepairneeded = 0;
  short indexrepairneeded = 0;
  short silent = stream->silent;
  *idxf = NIL;			/* in case error */
				/* readonly means no updates */
  if (stream->rdonly) iflags = sflags = NIL;
				/* open index file */
  if ((fd = open (LOCAL->index,iflags ? O_RDWR : O_RDONLY,NIL)) < 0)
    MM_LOG ("Error opening mix index file",ERROR);
				/* acquire exclusive access and FILE */
  else if (!flock (fd,iflags ? LOCK_EX : LOCK_SH) &&
	   !(*idxf = fdopen (fd,iflags ? "r+b" : "rb"))) {
    MM_LOG ("Error obtaining stream on mix index file",ERROR);
    flock (fd,LOCK_UN);		/* relinquish lock */
    close (fd);
  }

				/* slurp metadata */
  else if (s = mix_meta_slurp (stream,&i)) {
    unsigned long j = 0;	/* non-zero if UIDVALIDITY/UIDLAST changed */
    if (i != LOCAL->metaseq) {	/* metadata changed? */
      char *t,*k;
      LOCAL->metaseq = i;	/* note new metadata sequence */
      while (s && *s) {		/* parse entire metadata file */
				/* locate end of line */
	if (s = strstr (t = s,"\015\012")) {
	  *s = '\0';		/* tie off line */
	  s += 2;		/* skip past CRLF */
	  switch (*t++) {	/* parse line */
	  case 'V':		/* UIDVALIDITY */
	    if (!isxdigit (*t) || !(i = strtoul (t,&t,16))) {
	      MM_LOG ("Error in mix metadata file UIDVALIDITY record",ERROR);
	      return NIL;	/* give up */
	    }
	    if (i != stream->uid_validity) j = stream->uid_validity = i;
	    break;
	  case 'L':		/* new UIDLAST */
	    if (!isxdigit (*t)) {
	      MM_LOG ("Error in mix metadata file UIDLAST record",ERROR);
	      return NIL;	/* give up */
	    }
	    if ((i = strtoul (t,&t,16)) != stream->uid_last)
	      j = stream->uid_last = i;
	    break;
	  case 'N':		/* new message file */
	    if (!isxdigit (*t)) {
	      MM_LOG ("Error in mix metadata file new msg record",ERROR);
	      return NIL;	/* give up */
	    }
	    if ((i = strtoul (t,&t,16)) != stream->uid_last)
	      LOCAL->newmsg = i;
	    break;
	  case 'K':		/* new keyword list */
	    for (i = 0; t && *t && (i < NUSERFLAGS); ++i) {
	      if (t = strchr (k = t,' ')) *t++ = '\0';
				/* make sure keyword non-empty */
	      if (*k && (strlen (k) <= MAXUSERFLAG)) {
				/* in case value changes (shouldn't happen) */
		if (stream->user_flags[i] && strcmp (stream->user_flags[i],k)){
		  char tmp[MAILTMPLEN];
		  sprintf (tmp,"flag rename old=%.80s new=%.80s",
			   stream->user_flags[i],k);
		  MM_LOG (tmp,WARN);
		  fs_give ((void **) &stream->user_flags[i]);
		}
		if (!stream->user_flags[i]) stream->user_flags[i] = cpystr (k);
	      }
	      else break;	/* empty keyword */
	    }
	    if ((i < NUSERFLAGS) && stream->user_flags[i]) {
	      MM_LOG ("Error in mix metadata file keyword record",ERROR);
	      return NIL;	/* give up */
	    }
	    else if (i == NUSERFLAGS) stream->kwd_create = NIL;
	    break;
	  }
	}
	if (t && *t) {		/* junk in line */
	  MM_LOG ("Error in mix metadata record",ERROR);
	  return NIL;		/* give up */
	}
      }
    }

				/* get sequence */
    if (!(i = mix_read_sequence (*idxf)) || (i < LOCAL->indexseq)) {
      MM_LOG ("Error in mix index file sequence record",ERROR);
      return NIL;		/* give up */
    }
				/* sequence changed from last time? */
    else if (j || (i > LOCAL->indexseq)) {
      unsigned long uid,nmsgs,curfile,curfilesize,curpos;
      char *t,*msg,tmp[MAILTMPLEN];
				/* start with no messages */
      curfile = curfilesize = curpos = nmsgs = 0;
				/* update sequence iff expunging OK */
      if (LOCAL->expok) LOCAL->indexseq = i;
				/* get first elt */
      while ((s = mix_read_record (*idxf,LOCAL->buf,LOCAL->buflen,"index")) &&
	     *s)
	switch (*s) {
	case ':':		/* message record */
	  if (!(isxdigit (*++s) && (uid = strtoul (s,&t,16)))) msg = "UID";
	  else if (!((*t++ == ':') && isdigit (*t) && isdigit (t[1]) &&
		     isdigit (t[2]) && isdigit (t[3]) && isdigit (t[4]) &&
		     isdigit (t[5]) && isdigit (t[6]) && isdigit (t[7]) &&
		     isdigit (t[8]) && isdigit (t[9]) && isdigit (t[10]) &&
		     isdigit (t[11]) && isdigit (t[12]) && isdigit (t[13]) &&
		     ((t[14] == '+') || (t[14] == '-')) && 
		     isdigit (t[15]) && isdigit (t[16]) && isdigit (t[17]) &&
		     isdigit (t[18]))) msg = "internaldate";
	  else if ((*(s = t+19) != ':') || !isxdigit (*++s)) msg = "size";
	  else {
	    unsigned int y = (((*t - '0') * 1000) + ((t[1] - '0') * 100) +
			      ((t[2] - '0') * 10) + t[3] - '0') - BASEYEAR;
	    unsigned int m = ((t[4] - '0') * 10) + t[5] - '0';
	    unsigned int d = ((t[6] - '0') * 10) + t[7] - '0';
	    unsigned int hh = ((t[8] - '0') * 10) + t[9] - '0';
	    unsigned int mm = ((t[10] - '0') * 10) + t[11] - '0';
	    unsigned int ss = ((t[12] - '0') * 10) + t[13] - '0';
	    unsigned int z = (t[14] == '-') ? 1 : 0;
	    unsigned int zh = ((t[15] - '0') * 10) + t[16] - '0';
	    unsigned int zm = ((t[17] - '0') * 10) + t[18] - '0';
	    unsigned long size = strtoul (s,&s,16);
	    if ((*s++ == ':') && isxdigit (*s)) {
	      unsigned long file = strtoul (s,&s,16);
	      if ((*s++ == ':') && isxdigit (*s)) {
		unsigned long pos = strtoul (s,&s,16);
		if ((*s++ == ':') && isxdigit (*s)) {
		  unsigned long hpos = strtoul (s,&s,16);
		  if ((*s++ == ':') && isxdigit (*s)) {
		    unsigned long hsiz = strtoul (s,&s,16);
		    if (uid > stream->uid_last) {
		      sprintf (tmp,"mix index invalid UID (%08lx < %08lx)",
			       uid,stream->uid_last);
		      if (stream->rdonly) {
			MM_LOG (tmp,ERROR);
			return NIL;
		      }
		      strcat (tmp,", repaired");
		      MM_LOG (tmp,WARN);
		      stream->uid_last = uid;
		      metarepairneeded = T;
		    }

				/* ignore expansion values */
		    if (*s++ == ':') {
		      MESSAGECACHE *elt;
		      ++nmsgs;	/* this is another mesage */
				/* within current known range of messages? */
		      while (nmsgs <= stream->nmsgs) {
				/* yes, get corresponding elt */
			elt = mail_elt (stream,nmsgs);
				/* existing message with matching data? */
			if (uid == elt->private.uid) {
				/* beware of Dracula's resurrection */
			  if (elt->private.ghost) {
			    sprintf (tmp,"mix index data unexpunged UID: %lx",
				     uid);
			    MM_LOG (tmp,ERROR);
			    return NIL;
			  }
				/* also of static data changing */
			  if ((size != elt->rfc822_size) ||
			      (file != elt->private.spare.data) ||
			      (pos != elt->private.special.offset) ||
			      (hpos != elt->private.msg.header.offset) ||
			      (hsiz != elt->private.msg.header.text.size) ||
			      (y != elt->year) || (m != elt->month) ||
			      (d != elt->day) || (hh != elt->hours) ||
			      (mm != elt->minutes) || (ss != elt->seconds) ||
			      (z != elt->zoccident) || (zh != elt->zhours) ||
			      (zm != elt->zminutes)) {