ipop3d.c

广泛使用的邮件服务器！同时

  while (!PSIN ((char *) resp,RESPBUFLEN)) {
				/* ignore if some interrupt */
    if (ferror (stdin) && (errno == EINTR)) clearerr (stdin);
    else {
      char *e = ferror (stdin) ?
	strerror (errno) : "Command stream end of file";
      alarm (0);		/* disable all interrupts */
      server_init (NIL,NIL,NIL,SIG_IGN,SIG_IGN,SIG_IGN,SIG_IGN,SIG_IGN);
      sprintf (logout = tmp,"%.80s, while reading authentication",e);
      goodbye = NIL;
      state = LOGOUT;
      sayonara (1);
    }
  }
  if (!(t = (unsigned char *) strchr ((char *) resp,'\012'))) {
    int c;
    while ((c = PBIN ()) != '\012') if (c == EOF) {
				/* ignore if some interrupt */
      if (ferror (stdin) && (errno == EINTR)) clearerr (stdin);
      else {
	char *e = ferror (stdin) ?
	  strerror (errno) : "Command stream end of file";
	alarm (0);		/* disable all interrupts */
	server_init (NIL,NIL,NIL,SIG_IGN,SIG_IGN,SIG_IGN,SIG_IGN,SIG_IGN);
	sprintf (logout = tmp,"%.80s, while reading auth char",e);
	goodbye = NIL;
	state = LOGOUT;
	sayonara (1);
      }
    }
    return NIL;
  }
  alarm (0);			/* make sure timeout disabled */
  if (t[-1] == '\015') --t;	/* remove CR */
  *t = '\0';			/* tie off buffer */
  return (resp[0] != '*') ?
    (char *) rfc822_base64 (resp,t-resp,rlen ? rlen : &i) : NIL;
}

/* Select mailbox
 * Accepts: mailbox name
 * Returns: new state
 */

int mbxopen (char *mailbox)
{
  unsigned long i,j;
  char tmp[MAILTMPLEN];
  MESSAGECACHE *elt;
  if (msg) fs_give ((void **) &msg);
				/* open mailbox */
  if (!(stream = mail_open (stream,mailbox,NIL)))
    goodbye = "-ERR Unable to open user's INBOX\015\012";
  else if (stream->rdonly)	/* make sure not readonly */
    goodbye = "-ERR Can't get lock.  Mailbox in use\015\012";
  else {
    nmsgs = 0;			/* no messages yet */
    if (j = stream->nmsgs) {	/* if mailbox non-empty */
      sprintf (tmp,"1:%lu",j);	/* fetch fast information for all messages */
      mail_fetch_fast (stream,tmp,NIL);
    }
				/* create 1-origin tables */
    msg = (long *) fs_get (++j * sizeof (long));
    flags = (short *) fs_get (j * sizeof (short));
				/* build map */
    for (i = 1; i < j; ++i) if (!(elt = mail_elt (stream,i))->deleted) {
      msg[++nmsgs] = i;		/* note the presence of this message */
      if (elt->seen) il = nmsgs;/* and set up initial LAST */
    }
				/* make sure unused map entries are zero */
    for (i = nmsgs + 1; i < j; ++i) msg[i] = 0;
    rset ();			/* do implicit RSET */
    sprintf (tmp,"+OK Mailbox open, %lu messages\015\012",nmsgs);
    PSOUT (tmp);
    return TRANSACTION;
  }
  syslog (LOG_INFO,"Error opening or locking INBOX user=%.80s host=%.80s",
	  user,tcp_clienthost ());
  return UPDATE;
}

/* Blat a string with dot checking
 * Accepts: string
 *	    maximum number of lines if greater than zero
 *	    maximum number of bytes to output
 *	    alternative stringstruct
 * Returns: number of lines output
 *
 * This routine is uglier and kludgier than it should be, just to be robust
 * in the case of a message which doesn't end in a newline.  Yes, this routine
 * does truncate the last two bytes from the text.  Since it is normally a
 * newline and the main routine adds it back, it usually does not make a
 * difference.  But if it isn't, since the newline is required and the octet
 * counts have to match, there's no choice but to truncate.
 */

long blat (char *text,long lines,unsigned long size,STRING *st)
{
  char c,d,e;
  long ret = 0;
				/* no-op if zero lines or empty string */
  if (!(lines && (size-- > 2))) return 0;
  if (text) {
    c = *text++; d = *text++;	/* collect first two bytes */
    if (c == '.') PBOUT ('.');	/* double string-leading dot if necessary */
    while (lines && --size) {	/* copy loop */
      e = *text++;		/* get next byte */
      PBOUT (c);		/* output character */
      if (c == '\012') {	/* end of line? */
	ret++; --lines;		/* count another line */
				/* double leading dot as necessary */
	if (lines && size && (d == '.')) PBOUT ('.');
      }
      c = d; d = e;		/* move to next character */
    }
  }
  else {
    c = SNX (st); d = SNX (st);	/* collect first two bytes */
    if (c == '.') PBOUT ('.');	/* double string-leading dot if necessary */
    while (lines && --size) {	/* copy loop */
      e = SNX (st);		/* get next byte */
      PBOUT (c);		/* output character */
      if (c == '\012') {	/* end of line? */
	ret++; --lines;		/* count another line */
				/* double leading dot as necessary */
	if (lines && size && (d == '.')) PBOUT ('.');
      }
      c = d; d = e;		/* move to next character */
    }
  }
  return ret;
}

/* Reset mailbox
 */

void rset ()
{
				/* clear all flags */
  if (flags) memset ((void *) flags,0,(nmsgs + 1) * sizeof (short));
  ndele = nseen = 0;		/* no more deleted or seen messages */
  last = il;			/* restore previous LAST value */
}

/* Co-routines from MAIL library */


/* Message matches a search
 * Accepts: MAIL stream
 *	    message number
 */

void mm_searched (MAILSTREAM *stream,unsigned long msgno)
{
  /* Never called */
}


/* Message exists (i.e. there are that many messages in the mailbox)
 * Accepts: MAIL stream
 *	    message number
 */

void mm_exists (MAILSTREAM *stream,unsigned long number)
{
  /* Can't use this mechanism.  POP has no means of notifying the client of
     new mail during the session. */
}


/* Message expunged
 * Accepts: MAIL stream
 *	    message number
 */

void mm_expunged (MAILSTREAM *stream,unsigned long number)
{
  unsigned long i = number + 1;
  msg[number] = 0;		/* I bet that this will annoy someone */
  while (i <= nmsgs) --msg[i++];
}


/* Message flag status change
 * Accepts: MAIL stream
 *	    message number
 */

void mm_flags (MAILSTREAM *stream,unsigned long number)
{
  /* This isn't used */
}


/* Mailbox found
 * Accepts: MAIL stream
 *	    hierarchy delimiter
 *	    mailbox name
 *	    mailbox attributes
 */

void mm_list (MAILSTREAM *stream,int delimiter,char *name,long attributes)
{
  /* This isn't used */
}


/* Subscribe mailbox found
 * Accepts: MAIL stream
 *	    hierarchy delimiter
 *	    mailbox name
 *	    mailbox attributes
 */

void mm_lsub (MAILSTREAM *stream,int delimiter,char *name,long attributes)
{
  /* This isn't used */
}


/* Mailbox status
 * Accepts: MAIL stream
 *	    mailbox name
 *	    mailbox status
 */

void mm_status (MAILSTREAM *stream,char *mailbox,MAILSTATUS *status)
{
  /* This isn't used */
}

/* Notification event
 * Accepts: MAIL stream
 *	    string to log
 *	    error flag
 */

void mm_notify (MAILSTREAM *stream,char *string,long errflg)
{
  mm_log (string,errflg);	/* just do mm_log action */
}


/* Log an event for the user to see
 * Accepts: string to log
 *	    error flag
 */

void mm_log (char *string,long errflg)
{
  switch (errflg) {
  case NIL:			/* information message */
  case PARSE:			/* parse glitch */
    break;			/* too many of these to log */
  case WARN:			/* warning */
    syslog (LOG_DEBUG,"%s",string);
    break;
  case BYE:			/* driver broke connection */
    if (state != UPDATE) {
      char tmp[MAILTMPLEN];
      alarm (0);		/* disable all interrupts */
      server_init (NIL,NIL,NIL,SIG_IGN,SIG_IGN,SIG_IGN,SIG_IGN,SIG_IGN);
      sprintf (logout = tmp,"Mailbox closed (%.80s)",string);
      goodbye = NIL;
      state = LOGOUT;
      sayonara (1);
    }
    break;
  case ERROR:			/* error that broke command */
  default:			/* default should never happen */
    syslog (LOG_NOTICE,"%s",string);
    break;
  }
}    


/* Log an event to debugging telemetry
 * Accepts: string to log
 */

void mm_dlog (char *string)
{
  /* Not doing anything here for now */
}


/* Get user name and password for this host
 * Accepts: parse of network mailbox name
 *	    where to return user name
 *	    where to return password
 *	    trial count
 */

void mm_login (NETMBX *mb,char *username,char *password,long trial)
{
				/* set user name */
  strncpy (username,*mb->user ? mb->user : user,NETMAXUSER-1);
  if (pass) {
    strncpy (password,pass,255);/* and password */
    fs_give ((void **) &pass);
  }
  else memset (password,0,256);	/* no password to send, abort login */
  username[NETMAXUSER] = password[255] = '\0';
}

/* About to enter critical code
 * Accepts: stream
 */

void mm_critical (MAILSTREAM *stream)
{
  ++critical;
}


/* About to exit critical code
 * Accepts: stream
 */

void mm_nocritical (MAILSTREAM *stream)
{
  --critical;
}


/* Disk error found
 * Accepts: stream
 *	    system error code
 *	    flag indicating that mailbox may be clobbered
 * Returns: abort flag
 */

long mm_diskerror (MAILSTREAM *stream,long errcode,long serious)
{
  if (serious) {		/* try your damnest if clobberage likely */
    syslog (LOG_ALERT,
	    "Retrying after disk error user=%.80s host=%.80s mbx=%.80s: %.80s",
	    user,tcp_clienthost (),
	    (stream && stream->mailbox) ? stream->mailbox : "???",
	    strerror (errcode));
    alarm (0);			/* make damn sure timeout disabled */
    sleep (60);			/* give it some time to clear up */
    return NIL;
  }
  syslog (LOG_ALERT,"Fatal disk error user=%.80s host=%.80s mbx=%.80s: %.80s",
	  user,tcp_clienthost (),
	  (stream && stream->mailbox) ? stream->mailbox : "???",
	  strerror (errcode));
  return T;
}


/* Log a fatal error event
 * Accepts: string to log
 */

void mm_fatal (char *string)
{
  mm_log (string,ERROR);	/* shouldn't happen normally */
}