unix.c

这是用C编写IMAP源代码

      if (reparse && unix_parse (stream,&lock,LOCK_SH)) {
				/* unlock mailbox */
	unix_unlock (LOCAL->fd,stream,&lock);
	mail_unlock (stream);	/* and stream */
	MM_NOCRITICAL (stream);	/* done with critical */
      }
    }
  }
  return LOCAL ? LONGT : NIL;	/* return if still alive */
}

/* UNIX mail check mailbox
 * Accepts: MAIL stream
 */

void unix_check (MAILSTREAM *stream)
{
  DOTLOCK lock;
				/* parse and lock mailbox */
  if (LOCAL && (LOCAL->ld >= 0) && !stream->lock &&
      unix_parse (stream,&lock,LOCK_EX)) {
				/* any unsaved changes? */
    if (LOCAL->dirty && unix_rewrite (stream,NIL,&lock)) {
      if (!stream->silent) MM_LOG ("Checkpoint completed",NIL);
    }
				/* no checkpoint needed, just unlock */
    else unix_unlock (LOCAL->fd,stream,&lock);
    mail_unlock (stream);	/* unlock the stream */
    MM_NOCRITICAL (stream);	/* done with critical */
  }
}


/* UNIX mail expunge mailbox
 * Accepts: MAIL stream
 */

void unix_expunge (MAILSTREAM *stream)
{
  unsigned long i;
  DOTLOCK lock;
  char *msg = NIL;
				/* parse and lock mailbox */
  if (LOCAL && (LOCAL->ld >= 0) && !stream->lock &&
      unix_parse (stream,&lock,LOCK_EX)) {
				/* count expunged messages if not dirty */
    if (!LOCAL->dirty) for (i = 1; i <= stream->nmsgs; i++)
      if (mail_elt (stream,i)->deleted) LOCAL->dirty = T;
    if (!LOCAL->dirty) {	/* not dirty and no expunged messages */
      unix_unlock (LOCAL->fd,stream,&lock);
      msg = "No messages deleted, so no update needed";
    }
    else if (unix_rewrite (stream,&i,&lock)) {
      if (i) sprintf (msg = LOCAL->buf,"Expunged %lu messages",i);
      else msg = "Mailbox checkpointed, but no messages expunged";
    }
				/* rewrite failed */
    else unix_unlock (LOCAL->fd,stream,&lock);
    mail_unlock (stream);	/* unlock the stream */
    MM_NOCRITICAL (stream);	/* done with critical */
    if (msg && !stream->silent) MM_LOG (msg,NIL);
  }
  else if (!stream->silent) MM_LOG("Expunge ignored on readonly mailbox",WARN);
}

/* UNIX mail copy message(s)
 * Accepts: MAIL stream
 *	    sequence
 *	    destination mailbox
 *	    copy options
 * Returns: T if copy successful, else NIL
 */

long unix_copy (MAILSTREAM *stream,char *sequence,char *mailbox,long options)
{
  struct stat sbuf;
  int fd;
  char *s,file[MAILTMPLEN];
  DOTLOCK lock;
  time_t tp[2];
  unsigned long i,j;
  MESSAGECACHE *elt;
  long ret = T;
  mailproxycopy_t pc =
    (mailproxycopy_t) mail_parameters (stream,GET_MAILPROXYCOPY,NIL);
  if (!((options & CP_UID) ? mail_uid_sequence (stream,sequence) :
	mail_sequence (stream,sequence))) return NIL;
				/* make sure valid mailbox */
  if (!unix_valid (mailbox)) switch (errno) {
  case ENOENT:			/* no such file? */
    if (!compare_cstring (mailbox,"INBOX")) {
      if (pc) return (*pc) (stream,sequence,mailbox,options);
      unix_create (NIL,"INBOX");/* create empty INBOX */
      break;
    }
    MM_NOTIFY (stream,"[TRYCREATE] Must create mailbox before copy",NIL);
    return NIL;
  case 0:			/* merely empty file? */
    break;
  case EINVAL:
    if (pc) return (*pc) (stream,sequence,mailbox,options);
    sprintf (LOCAL->buf,"Invalid UNIX-format mailbox name: %.80s",mailbox);
    MM_LOG (LOCAL->buf,ERROR);
    return NIL;
  default:
    if (pc) return (*pc) (stream,sequence,mailbox,options);
    sprintf (LOCAL->buf,"Not a UNIX-format mailbox: %.80s",mailbox);
    MM_LOG (LOCAL->buf,ERROR);
    return NIL;
  }
  LOCAL->buf[0] = '\0';
  MM_CRITICAL (stream);		/* go critical */
  if ((fd = unix_lock (dummy_file (file,mailbox),O_WRONLY|O_APPEND|O_CREAT,
		       S_IREAD|S_IWRITE,&lock,LOCK_EX)) < 0) {
    MM_NOCRITICAL (stream);	/* done with critical */
    sprintf (LOCAL->buf,"Can't open destination mailbox: %s",strerror (errno));
    MM_LOG (LOCAL->buf,ERROR);/* log the error */
    return NIL;			/* failed */
  }
  fstat (fd,&sbuf);		/* get current file size */

				/* write all requested messages to mailbox */
  for (i = 1; ret && (i <= stream->nmsgs); i++)
    if ((elt = mail_elt (stream,i))->sequence) {
      lseek (LOCAL->fd,elt->private.special.offset,L_SET);
      read (LOCAL->fd,LOCAL->buf,elt->private.special.text.size);
      if (write (fd,LOCAL->buf,elt->private.special.text.size) < 0) ret = NIL;
      else {			/* internal header succeeded */
	s = unix_header (stream,i,&j,FT_INTERNAL);
				/* header size, sans trailing newline */
	if (j && (s[j - 2] == '\n')) j--;
	if (write (fd,s,j) < 0) ret = NIL;
	else {			/* message header succeeded */
	  j = unix_xstatus (stream,LOCAL->buf,elt,NIL);
	  if (write (fd,LOCAL->buf,j) < 0) ret = NIL;
	  else {		/* message status succeeded */
	    s = unix_text_work (stream,elt,&j,FT_INTERNAL);
	    if ((write (fd,s,j) < 0) || (write (fd,"\n",1) < 0)) ret = NIL;
	  }
	}
      }
    }
  if (!ret || fsync (fd)) {	/* force out the update */
    sprintf (LOCAL->buf,"Message copy failed: %s",strerror (errno));
    ftruncate (fd,sbuf.st_size);
    ret = NIL;
  }
  tp[1] = time (0);		/* set mtime to now */
  if (ret) tp[0] = tp[1] - 1;	/* set atime to now-1 if successful copy */
  else tp[0] =			/* else preserve \Marked status */
	 ((sbuf.st_ctime > sbuf.st_atime) || (sbuf.st_mtime > sbuf.st_atime)) ?
	 sbuf.st_atime : tp[1];
  utime (file,tp);		/* set the times */
  unix_unlock (fd,NIL,&lock);	/* unlock and close mailbox */
  MM_NOCRITICAL (stream);	/* release critical */
				/* log the error */
  if (!ret) MM_LOG (LOCAL->buf,ERROR);
				/* delete if requested message */
  else if (options & CP_MOVE) for (i = 1; i <= stream->nmsgs; i++)
    if ((elt = mail_elt (stream,i))->sequence)
      elt->deleted = elt->private.dirty = LOCAL->dirty = T;
  return ret;
}

/* UNIX mail append message from stringstruct
 * Accepts: MAIL stream
 *	    destination mailbox
 *	    append callback
 *	    data for callback
 * Returns: T if append successful, else NIL
 */

#define BUFLEN 8*MAILTMPLEN

long unix_append (MAILSTREAM *stream,char *mailbox,append_t af,void *data)
{
  struct stat sbuf;
  int fd;
  unsigned long i,j;
  char *flags,*date,buf[BUFLEN],tmp[MAILTMPLEN],file[MAILTMPLEN];
  time_t tp[2];
  FILE *sf,*df;
  MESSAGECACHE elt;
  DOTLOCK lock;
  STRING *message;
  MAILSTREAM *tstream = NIL;
  long ret = LONGT;
  if (!stream) {		/* stream specified? */
    stream = &unixproto;	/* no, default stream to prototype */
    for (i = 0; i < NUSERFLAGS && stream->user_flags[i]; ++i)
      fs_give ((void **) &stream->user_flags[i]);
    stream->kwd_create = T;	/* allow new flags */
  }
				/* make sure valid mailbox */
  if (!unix_valid (mailbox)) switch (errno) {
  case ENOENT:			/* no such file? */
    if (!compare_cstring (mailbox,"INBOX")) {
      unix_create (NIL,"INBOX");/* create empty INBOX */
      break;
    }
    MM_NOTIFY (stream,"[TRYCREATE] Must create mailbox before append",NIL);
    return NIL;
  case 0:			/* merely empty file? */
    break;
  case EINVAL:
    sprintf (tmp,"Invalid UNIX-format mailbox name: %.80s",mailbox);
    MM_LOG (tmp,ERROR);
    return NIL;
  default:
    sprintf (tmp,"Not a UNIX-format mailbox: %.80s",mailbox);
    MM_LOG (tmp,ERROR);
    return NIL;
  }
				/* get first message */
  if (!MM_APPEND (af) (stream,data,&flags,&date,&message)) return NIL;
  if (!(sf = tmpfile ())) {	/* must have scratch file */
    sprintf (tmp,".%lx.%lx",(unsigned long) time (0),(unsigned long)getpid ());
    if (!stat (tmp,&sbuf) || !(sf = fopen (tmp,"wb+"))) {
      sprintf (tmp,"Unable to create scratch file: %.80s",strerror (errno));
      MM_LOG (tmp,ERROR);
      return NIL;
    }
    unlink (tmp);
  }

  do {				/* parse date */
    if (!date) rfc822_date (date = tmp);
    if (!mail_parse_date (&elt,date)) {
      sprintf (tmp,"Bad date in append: %.80s",date);
      MM_LOG (tmp,ERROR);
    }
    else {			/* user wants to suppress time zones? */
      if (mail_parameters (NIL,GET_NOTIMEZONES,NIL)) {
	time_t when = mail_longdate (&elt);
	date = ctime (&when);	/* use traditional date */
      }
				/* use POSIX-style date */
      else date = mail_cdate (tmp,&elt);
      if (!SIZE (message)) MM_LOG ("Append of zero-length message",ERROR);
      else if (!unix_append_msg (stream,sf,flags,date,message)) {
	sprintf (tmp,"Error writing scratch file: %.80s",strerror (errno));
	MM_LOG (tmp,ERROR);
      }
				/* get next message */
      else if (MM_APPEND (af) (stream,data,&flags,&date,&message)) continue;
    }
    fclose (sf);		/* punt scratch file */
    return NIL;			/* give up */
  } while (message);		/* until no more messages */
  if (fflush (sf) || fstat (fileno (sf),&sbuf)) {
    sprintf (tmp,"Error finishing scratch file: %.80s",strerror (errno));
    MM_LOG (tmp,ERROR);
    fclose (sf);		/* punt scratch file */
    return NIL;			/* give up */
  }
  i = sbuf.st_size;		/* size of scratch file */

  MM_CRITICAL (stream);		/* go critical */
  if (((fd = unix_lock (dummy_file (file,mailbox),O_WRONLY|O_APPEND|O_CREAT,
		       S_IREAD|S_IWRITE,&lock,LOCK_EX)) < 0) ||
      !(df = fdopen (fd,"ab"))) {
    MM_NOCRITICAL (stream);	/* done with critical */
    sprintf (tmp,"Can't open append mailbox: %s",strerror (errno));
    MM_LOG (tmp,ERROR);
    return NIL;
  }
  fstat (fd,&sbuf);		/* get current file size */
  rewind (sf);
  for (; i && ((j = fread (buf,1,min ((long) BUFLEN,i),sf)) &&
	       (fwrite (buf,1,j,df) == j)); i -= j);
  fclose (sf);			/* done with scratch file */
  tp[1] = time (0);		/* set mtime to now */
				/* make sure append wins, fsync() necessary */
  if (i || (fflush (df) == EOF) || fsync (fd)) {
    sprintf (buf,"Message append failed: %s",strerror (errno));
    MM_LOG (buf,ERROR);
    ftruncate (fd,sbuf.st_size);
    tp[0] =			/* preserve \Marked status */
      ((sbuf.st_ctime > sbuf.st_atime) || (sbuf.st_mtime > sbuf.st_atime)) ?
      sbuf.st_atime : tp[1];
    ret = NIL;			/* return error */
  }
  else tp[0] = tp[1] - 1;	/* set atime to now-1 if successful copy */
  utime (file,tp);		/* set the times */
  unix_unlock (fd,NIL,&lock);	/* unlock and close mailbox */
  fclose (df);			/* note that unix_unlock() released the fd */
  MM_NOCRITICAL (stream);	/* release critical */
  return ret;
}

/* Write single message to append scratch file
 * Accepts: MAIL stream
 *	    scratch file
 *	    flags
 *	    message stringstruct
 * Returns: NIL if write error, else T
 */

int unix_append_msg (MAILSTREAM *stream,FILE *sf,char *flags,char *date,
		     STRING *msg)
{
  int ti,zn,c;
  unsigned long i,uf;
  char *x,tmp[MAILTMPLEN];
  int hdrp = T;
  long f = mail_parse_flags (stream,flags,&uf);
				/* build initial header */
  if ((fprintf (sf,"From %s@%s %sStatus: ",
		myusername (),mylocalhost (),date) < 0) ||
      (f&fSEEN && (putc ('R',sf) == EOF)) ||
      (fputs ("\nX-Status: ",sf) == EOF) ||
      (f&fDELETED && (putc ('D',sf) == EOF)) ||
      (f&fFLAGGED && (putc ('F',sf) == EOF)) ||
      (f&fANSWERED && (putc ('A',sf) == EOF)) ||
      (f&fDRAFT && (putc ('T',sf) == EOF)) ||
      (fputs ("\nX-Keywords:",sf) == EOF)) return NIL;
  while (uf)			/* write user flags */
    if (fprintf (sf," %s",stream->user_flags[find_rightmost_bit (&uf)]) < 0)
      return NIL;
				/* tie off flags */
  if (putc ('\n',sf) == EOF) return NIL;

  while (SIZE (msg)) {		/* copy text to scratch file */
				/* disregard CRs */
    while ((c = (SIZE (msg)) ? (0xff & SNX (msg)) : '\n') == '\r');
				/* see if line needs special treatment */
    if ((c == 'F') || (hdrp && ((c == 'S') || (c == 'X')))) {
				/* copy line to buffer */
      for (i = 1,tmp[0] = c; (c != '\n') && (i < MAILTMPLEN); )
	if ((c = (SIZE (msg)) ? (0xff & SNX (msg)) : '\n') != '\r')
	  tmp[i++] = c;
				/* possible "From " line? */
      if ((i > 4) && (tmp[0] == 'F') && (tmp[1] == 'r') && (tmp[2] == 'o') &&
	  (tmp[3] == 'm') && (tmp[4] == ' ')) {
				/* yes, see if need to write a widget */
	if (!(ti = unix_fromwidget || (c != '\n'))) VALID (tmp,x,ti,zn);
	if (ti && (putc ('>',sf) == EOF)) return NIL;
      }
				/* insert X- before metadata header */
      else if ((((i > 6) && (tmp[0] == 'S') && (tmp[1] == 't') &&
		 (tmp[2] == 'a') && (tmp[3] == 't') && (tmp[4] == 'u') &&
		 (tmp[5] == 's') && (tmp[6] == ':')) ||
		(((i > 5) && (tmp[0] == 'X') && (tmp[1] == '-')) &&
		 (((tmp[2] == 'U') && (tmp[3] == 'I') && (tmp[4] == 'D') &&
		   (tmp[5] == ':')) ||
		  ((i > 6) && (tmp[2] == 'I') && (tmp[3] == 'M') &&
		   (tmp[4] == 'A') && (tmp[5] == 'P') &&
		   ((tmp[6] == ':') ||
		    ((i > 10) && (tmp[6] == 'b') && (tmp[7] == 'a') &&
		     (tmp[8] == 's') && (tmp[9] == 'e') &&
		     (tmp[10] == ':')))) ||
		  ((i > 8) && (tmp[2] == 'S') && (tmp[3] == 't') &&
		   (tmp[4] == 'a') && (tmp[5] == 't') && (tmp[6] == 'u') &&
		   (tmp[7] == 's') && (tmp[8] == ':')) ||
		  ((i > 10) && (tmp[2] == 'K') && (tmp[3] == 'e') &&
		   (tmp[4] == 'y') && (tmp[5] == 'w') && (tmp[6] == 'o') &&
		   (tmp[7] == 'r') && (tmp[8] == 'd') && (tmp[9] == 's') &&
		   (tmp[10] == ':'))))) && (fputs ("X-Original-",sf) == EOF))
	return NIL;
				/* write buffered text */
      if (fwrite (tmp,1,i,sf) != i) return NIL;
				/* set up to copy remainder of line */
      if ((c != '\n') && SIZE (msg)) c = 0xff & SNX (msg);
      else continue;		/* end of line or end of message */
    }
				/* check for end of header */
    else if (hdrp && (c == '\n')) hdrp = NIL;
				/* copy line, tossing out CR */
    do if ((c != '\r') && (putc (c,sf) == EOF)) return NIL;
    while ((c != '\n') && SIZE (msg) && ((c = 0xff & SNX (msg)) ? c : T));
  }
				/* write trailing newline and return */
  return (putc ('\n',sf) == EOF) ? NIL : T;
}