unix.c

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  if (((fd = unix_lock (dummy_file (file,mailbox),O_WRONLY|O_APPEND,
		       (long) mail_parameters (NIL,GET_MBXPROTECTION,NIL),
			&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);
  tp[1] = time (0);		/* set mtime to now */
				/* write all messages */
  if (!unix_append_msgs (tstream,sf,df,au ? dst : NIL) ||
      (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 */
  fclose (sf);			/* done with scratch file */
				/* force UIDVALIDITY assignment now */
  if (tstream && !tstream->uid_validity) tstream->uid_validity = time (0);
				/* return sets if doing APPENDUID */
  if (au && ret) (*au) (mailbox,tstream->uid_validity,dst);
  else mail_free_searchset (&dst);
  unix_unlock (fd,NIL,&lock);	/* unlock and close mailbox */
  fclose (df);			/* note that unix_unlock() released the fd */
  if (tstream) {		/* update last UID if we can */
    UNIXLOCAL *local = (UNIXLOCAL *) tstream->local;
    local->dirty = T;		/* do a rewrite */
    local->appending = T;	/* but not at the cost of marking as old */
    tstream = mail_close (tstream);
  }
  MM_NOCRITICAL (stream);	/* release critical */
  return ret;
}

/* Collect and write single message to append scratch file
 * Accepts: MAIL stream
 *	    scratch file
 *	    flags
 *	    date
 *	    message stringstruct
 * Returns: NIL if write error, else T
 */

int unix_collect_msg (MAILSTREAM *stream,FILE *sf,char *flags,char *date,
		     STRING *msg)
{
  unsigned char *s,*t;
  unsigned long uf;
  long f = mail_parse_flags (stream,flags,&uf);
				/* write metadata, note date ends with NL */
  if (fprintf (sf,"%ld %lu %s",f,SIZE (msg) + 1,date) < 0) return NIL;
  while (uf)			/* write user flags */    
    if ((s = stream->user_flags[find_rightmost_bit (&uf)]) &&
	(fprintf (sf," %s",s) < 0)) return NIL;
  if (putc ('\n',sf) == EOF) return NIL;
  while (SIZE (msg)) {		/* copy text to scratch file */
    for (s = (unsigned char *) msg->curpos, t = s + msg->cursize; s < t; ++s)
      if (!*s) *s = 0x80;	/* disallow NUL */
				/* write buffered text */
    if (fwrite (msg->curpos,1,msg->cursize,sf) == msg->cursize)
      SETPOS (msg,GETPOS (msg) + msg->cursize);
    else return NIL;		/* failed */
  }
				/* write trailing newline and return */
  return (putc ('\n',sf) == EOF) ? NIL : T;
}

/* Append messages from scratch file to mailbox
 * Accepts: MAIL stream
 *	    source file
 *	    destination file
 *	    uidset to update if non-NIL
 * Returns: T if success, NIL if failure
 */

int unix_append_msgs (MAILSTREAM *stream,FILE *sf,FILE *df,SEARCHSET *set)
{
  int ti,zn,c;
  long f;
  unsigned long i,j;
  char *x,tmp[MAILTMPLEN];
  int hdrp = T;
				/* get message metadata line */
  while (fgets (tmp,MAILTMPLEN,sf)) {
    if (!(isdigit (tmp[0]) && strchr (tmp,'\n'))) return NIL;
    f = strtol (tmp,&x,10);	/* get flags */
    if (!((*x++ == ' ') && isdigit (*x))) return NIL;
    i = strtoul (x,&x,10);	/* get message size */
    if ((*x++ != ' ') ||	/* build initial header */
	(fprintf (df,"From %s@%s %sStatus: ",myusername(),mylocalhost(),x)<0)||
	(f&fSEEN && (putc ('R',df) == EOF)) ||
	(fputs ("\nX-Status: ",df) == EOF) ||
	(f&fDELETED && (putc ('D',df) == EOF)) ||
	(f&fFLAGGED && (putc ('F',df) == EOF)) ||
	(f&fANSWERED && (putc ('A',df) == EOF)) ||
	(f&fDRAFT && (putc ('T',df) == EOF)) ||
	(fputs ("\nX-Keywords:",df) == EOF)) return NIL;
				/* copy keywords */
    while ((c = getc (sf)) != '\n') switch (c) {
    case EOF:
      return NIL;
    default:
      if (putc (c,df) == EOF) return NIL;
    }
    if ((putc ('\n',df) == EOF) ||
	(set && (fprintf (df,"X-UID: %lu\n",++(stream->uid_last)) < 0)))
      return NIL;

    for (c = '\n'; i && fgets (tmp,MAILTMPLEN,sf); c = tmp[j-1]) {
				/* get read line length */
      if (i < (j = strlen (tmp))) fatal ("unix_append_msgs overrun");
      i -= j;			/* number of bytes left */
				/* squish out CRs (note also copies NUL) */
      for (x = tmp; x = strchr (x,'\r'); --j) memmove (x,x+1,j-(x-tmp));
      if (!j) continue;		/* do nothing if line emptied */
				/* start of line? */
      if ((c == '\n')) switch (tmp[0]) {
      case 'F':			/* possible "From " (case counts here) */
	if ((j > 4) && (tmp[0] == 'F') && (tmp[1] == 'r') && (tmp[2] == 'o') &&
	    (tmp[3] == 'm') && (tmp[4] == ' ')) {
	  if (!unix_fromwidget) {
	    VALID (tmp,x,ti,zn);/* conditional, only write widget if */
	    if (!ti) break;	/*  it looks like a valid header */
	  }			/* write the widget */
	  if (putc ('>',df) == EOF) return NIL;
	}
	break;
      case 'S': case 's':	/* possible "Status:" */
	if (hdrp && (j > 6) && ((tmp[1] == 't') || (tmp[1] == 'T')) &&
	    ((tmp[2] == 'a') || (tmp[2] == 'A')) &&
	    ((tmp[3] == 't') || (tmp[3] == 'T')) &&
	    ((tmp[4] == 'u') || (tmp[4] == 'U')) &&
	    ((tmp[5] == 's') || (tmp[5] == 'S')) && (tmp[6] == ':') &&
	    (fputs ("X-Original-",df) == EOF)) return NIL;
	break;
      case 'X': case 'x':	/* possible X-??? header */
	if (hdrp && (tmp[1] == '-') &&
				/* possible X-UID: */
	    (((j > 5) && ((tmp[2] == 'U') || (tmp[2] == 'u')) &&
	      ((tmp[3] == 'I') || (tmp[3] == 'i')) &&
	      ((tmp[4] == 'D') || (tmp[4] == 'd')) && (tmp[5] == ':')) ||
				/* possible X-IMAP: */
	     ((j > 6) && ((tmp[2] == 'I') || (tmp[2] == 'i')) &&
	      ((tmp[3] == 'M') || (tmp[3] == 'm')) &&
	      ((tmp[4] == 'A') || (tmp[4] == 'a')) &&
	      ((tmp[5] == 'P') || (tmp[5] == 'p')) &&
	      ((tmp[6] == ':') ||
				/* or X-IMAPbase: */
	       ((j > 10) && ((tmp[6] == 'b') || (tmp[6] == 'B')) &&
		((tmp[7] == 'a') || (tmp[7] == 'A')) &&
		((tmp[8] == 's') || (tmp[8] == 'S')) &&
		((tmp[9] == 'e') || (tmp[9] == 'E')) && (tmp[10] == ':')))) ||
				/* possible X-Status: */
	     ((j > 8) && ((tmp[2] == 'S') || (tmp[2] == 's')) &&
	      ((tmp[3] == 't') || (tmp[3] == 'T')) &&
	      ((tmp[4] == 'a') || (tmp[4] == 'A')) &&
	      ((tmp[5] == 't') || (tmp[5] == 'T')) &&
	      ((tmp[6] == 'u') || (tmp[6] == 'U')) &&
	      ((tmp[7] == 's') || (tmp[7] == 'S')) && (tmp[8] == ':')) ||
				/* possible X-Keywords: */
	     ((j > 10) && ((tmp[2] == 'K') || (tmp[2] == 'k')) &&
	      ((tmp[3] == 'e') || (tmp[3] == 'E')) &&
	      ((tmp[4] == 'y') || (tmp[4] == 'Y')) &&
	      ((tmp[5] == 'w') || (tmp[5] == 'W')) &&
	      ((tmp[6] == 'o') || (tmp[6] == 'O')) &&
	      ((tmp[7] == 'r') || (tmp[7] == 'R')) &&
	      ((tmp[8] == 'd') || (tmp[8] == 'D')) &&
	      ((tmp[9] == 's') || (tmp[9] == 'S')) && (tmp[10] == ':'))) &&
	    (fputs ("X-Original-",df) == EOF)) return NIL;
      case '\n':		/* blank line */
	hdrp = NIL;
	break;
      default:			/* nothing to do */
	break;
      }
				/* just write the line */
      if (fwrite (tmp,1,j,df) != j) return NIL;
    }
    if (i) return NIL;		/* didn't read entire message */
				/* update set */
    if (stream) mail_append_set (set,stream->uid_last);
  }
  return T;
}

/* Internal routines */


/* UNIX mail abort stream
 * Accepts: MAIL stream
 */

void unix_abort (MAILSTREAM *stream)
{
  if (LOCAL) {			/* only if a file is open */
    if (LOCAL->fd >= 0) close (LOCAL->fd);
    if (LOCAL->ld >= 0) {	/* have a mailbox lock? */
      flock (LOCAL->ld,LOCK_UN);/* yes, release the lock */
      close (LOCAL->ld);	/* close the lock file */
      unlink (LOCAL->lname);	/* and delete it */
    }
    if (LOCAL->lname) fs_give ((void **) &LOCAL->lname);
				/* free local text buffers */
    if (LOCAL->buf) fs_give ((void **) &LOCAL->buf);
    if (LOCAL->text.data) fs_give ((void **) &LOCAL->text.data);
    if (LOCAL->linebuf) fs_give ((void **) &LOCAL->linebuf);
    if (LOCAL->line) fs_give ((void **) &LOCAL->line);
				/* nuke the local data */
    fs_give ((void **) &stream->local);
    stream->dtb = NIL;		/* log out the DTB */
  }
}

/* UNIX open and lock mailbox
 * Accepts: file name to open/lock
 *	    file open mode
 *	    destination buffer for lock file name
 *	    type of locking operation (LOCK_SH or LOCK_EX)
 */

int unix_lock (char *file,int flags,int mode,DOTLOCK *lock,int op)
{
  int fd;
  blocknotify_t bn = (blocknotify_t) mail_parameters (NIL,GET_BLOCKNOTIFY,NIL);
  (*bn) (BLOCK_FILELOCK,NIL);
				/* try locking the easy way */
  if (dotlock_lock (file,lock,-1)) {
				/* got dotlock file, easy open */
    if ((fd = open (file,flags,mode)) >= 0) flock (fd,op);
    else dotlock_unlock (lock);	/* open failed, free the dotlock */
  }
				/* no dot lock file, open file now */
  else if ((fd = open (file,flags,mode)) >= 0) {
				/* try paranoid way to make a dot lock file */
    if (dotlock_lock (file,lock,fd)) {
      close (fd);		/* get fresh fd in case of timing race */
      if ((fd = open (file,flags,mode)) >= 0) flock (fd,op);
				/* open failed, free the dotlock */
      else dotlock_unlock (lock);
    }
    else flock (fd,op);		/* paranoid way failed, just flock() it */
  }
  (*bn) (BLOCK_NONE,NIL);
  return fd;
}

/* UNIX unlock and close mailbox
 * Accepts: file descriptor
 *	    (optional) mailbox stream to check atime/mtime
 *	    (optional) lock file name
 */

void unix_unlock (int fd,MAILSTREAM *stream,DOTLOCK *lock)
{
  if (stream) {			/* need to muck with times? */
    struct stat sbuf;
    time_t tp[2];
    time_t now = time (0);
    fstat (fd,&sbuf);		/* get file times */
    if (LOCAL->ld >= 0) {	/* yes, readwrite session? */
      tp[0] = now;		/* set atime to now */
				/* set mtime to (now - 1) if necessary */
      tp[1] = (now > sbuf.st_mtime) ? sbuf.st_mtime : now - 1;
    }
    else if (stream->recent) {	/* readonly with recent messages */
      if ((sbuf.st_atime >= sbuf.st_mtime) ||
	  (sbuf.st_atime >= sbuf.st_ctime))
				/* keep past mtime, whack back atime */
	tp[0] = (tp[1] = (sbuf.st_mtime < now) ? sbuf.st_mtime : now) - 1;
      else now = 0;		/* no time change needed */
    }
				/* readonly with no recent messages */
    else if ((sbuf.st_atime < sbuf.st_mtime) ||
	     (sbuf.st_atime < sbuf.st_ctime)) {
      tp[0] = now;		/* set atime to now */
				/* set mtime to (now - 1) if necessary */
      tp[1] = (now > sbuf.st_mtime) ? sbuf.st_mtime : now - 1;
    }
    else now = 0;		/* no time change needed */
				/* set the times, note change */
    if (now && !utime (stream->mailbox,tp)) LOCAL->filetime = tp[1];
  }
  flock (fd,LOCK_UN);		/* release flock'ers */
  if (!stream) close (fd);	/* close the file if no stream */
  dotlock_unlock (lock);	/* flush the lock file if any */
}

/* UNIX mail parse and lock mailbox
 * Accepts: MAIL stream
 *	    space to write lock file name
 *	    type of locking operation
 * Returns: T if parse OK, critical & mailbox is locked shared; NIL if failure
 */

int unix_parse (MAILSTREAM *stream,DOTLOCK *lock,int op)
{
  int zn;
  unsigned long i,j,k,m;
  unsigned char c,*s,*t,*u,tmp[MAILTMPLEN],date[30];
  int ti = 0,retain = T;
  unsigned long nmsgs = stream->nmsgs;
  unsigned long prevuid = nmsgs ? mail_elt (stream,nmsgs)->private.uid : 0;
  unsigned long recent = stream->recent;
  unsigned long oldnmsgs = stream->nmsgs;
  short silent = stream->silent;
  short pseudoseen = NIL;
  struct stat sbuf;
  STRING bs;
  FDDATA d;
  MESSAGECACHE *elt;
  mail_lock (stream);		/* guard against recursion or pingers */
				/* toss out previous descriptor */
  if (LOCAL->fd >= 0) close (LOCAL->fd);
  MM_CRITICAL (stream);		/* open and lock mailbox (shared OK) */
  if ((LOCAL->fd = unix_lock (stream->mailbox,(LOCAL->ld >= 0) ?
			      O_RDWR : O_RDONLY,
			      (long)mail_parameters(NIL,GET_MBXPROTECTION,NIL),
			      lock,op)) < 0) {
    sprintf (tmp,"Mailbox open failed, aborted: %s",strerror (errno));
    MM_LOG (tmp,ERROR);
    unix_abort (stream);
    mail_unlock (stream);
    MM_NOCRITICAL (stream);	/* done with critical */
    return NIL;
  }
  fstat (LOCAL->fd,&sbuf);	/* get status */
				/* validate change in size */
  if (sbuf.st_size < LOCAL->filesize) {
    sprintf (tmp,"Mailbox shrank from %lu to %lu bytes, aborted",
	     (unsigned long) LOCAL->filesize,(unsigned long) sbuf.st_size);
    MM_LOG (tmp,ERROR);		/* this is pretty bad */
    unix_unlock (LOCAL->fd,stream,lock);
    unix_abort (stream);
    mail_unlock (stream);
    MM_NOCRITICAL (stream);	/* done with critical */
    return NIL;
  }

				/* new data? */
  else if (i = sbuf.st_size - LOCAL->filesize) {
    d.fd = LOCAL->fd;		/* yes, set up file descriptor */
    d.pos = LOCAL->filesize;	/* get to that position in the file */
    d.chunk = LOCAL->buf;	/* initial buffer chunk */
    d.chunksize = CHUNKSIZE;	/* file chunk size */
    INIT (&bs,fd_string,&d,i);	/* initialize stringstruct */
				/* skip leading whitespace for broken MTAs */
    while (((c = CHR (&bs)) == '\n') || (c == '\r') ||
	   (c == ' ') || (c == '\t')) SNX (&bs);
    if (SIZE (&bs)) {		/* read new data */
				/* remember internal header position */
      j = LOCAL->filesize + GETPOS (&bs);
      s = unix_mbxline (stream,&bs,&i);
      t = NIL,zn = 0;
      if (i) VALID (s,t,ti,zn);	/* see if valid From line */
      if (!ti) {		/* someone pulled the rug from under us */
	sprintf (tmp,"Unexpected changes to mailbox (try restarting): %.20s",
		 (char *) s);
	MM_LOG (tmp,ERROR);
	unix_unlock (LOCAL->fd,stream,lock);
	unix_abort (stream);
	mail_unlock (stream);
				/* done with critical */
	MM_NOCRITICAL (stream);
	return NIL;
      }
      stream->silent = T;	/* quell main program new message events */
      do {			/* found a message */
				/* instantiate first new message */
	mail_exists (stream,++nmsgs);