pop3.c

广泛使用的邮件服务器！同时

/* ========================================================================
 * Copyright 1988-2007 University of Washington
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * 
 * ========================================================================
 */

/*
 * Program:	Post Office Protocol 3 (POP3) client routines
 *
 * Author:	Mark Crispin
 *		Networks and Distributed Computing
 *		Computing & Communications
 *		University of Washington
 *		Administration Building, AG-44
 *		Seattle, WA  98195
 *		Internet: [e-mail]
 *
 * Date:	6 June 1994
 * Last Edited:	4 April 2007
 */


#include <ctype.h>
#include <stdio.h>
#include <time.h>
#include "c-client.h"
#include "flstring.h"
#include "netmsg.h"

/* Parameters */

#define POP3TCPPORT (long) 110	/* assigned TCP contact port */
#define POP3SSLPORT (long) 995	/* assigned SSL TCP contact port */
#define IDLETIMEOUT (long) 10	/* defined in RFC 1939 */


/* POP3 I/O stream local data */
	
typedef struct pop3_local {
  NETSTREAM *netstream;		/* TCP I/O stream */
  char *response;		/* last server reply */
  char *reply;			/* text of last server reply */
  unsigned long cached;		/* current cached message uid */
  unsigned long hdrsize;	/* current cached header size */
  FILE *txt;			/* current cached file descriptor */
  struct {
    unsigned int capa : 1;	/* server has CAPA, definitely new */
    unsigned int expire : 1;	/* server has EXPIRE */
    unsigned int logindelay : 1;/* server has LOGIN-DELAY */
    unsigned int stls : 1;	/* server has STLS */
    unsigned int pipelining : 1;/* server has PIPELINING */
    unsigned int respcodes : 1;	/* server has RESP-CODES */
    unsigned int top : 1;	/* server has TOP */
    unsigned int uidl : 1;	/* server has UIDL */
    unsigned int user : 1;	/* server has USER */
    char *implementation;	/* server implementation string */
    long delaysecs;		/* minimum time between login (neg variable) */
    long expiredays;		/* server-guaranteed minimum retention days */
				/* supported authenticators */
    unsigned int sasl : MAXAUTHENTICATORS;
  } cap;
  unsigned int sensitive : 1;	/* sensitive data in progress */
  unsigned int loser : 1;	/* server is a loser */
  unsigned int saslcancel : 1;	/* SASL cancelled by protocol */
} POP3LOCAL;


/* Convenient access to local data */

#define LOCAL ((POP3LOCAL *) stream->local)

/* Function prototypes */

DRIVER *pop3_valid (char *name);
void *pop3_parameters (long function,void *value);
void pop3_scan (MAILSTREAM *stream,char *ref,char *pat,char *contents);
void pop3_list (MAILSTREAM *stream,char *ref,char *pat);
void pop3_lsub (MAILSTREAM *stream,char *ref,char *pat);
long pop3_subscribe (MAILSTREAM *stream,char *mailbox);
long pop3_unsubscribe (MAILSTREAM *stream,char *mailbox);
long pop3_create (MAILSTREAM *stream,char *mailbox);
long pop3_delete (MAILSTREAM *stream,char *mailbox);
long pop3_rename (MAILSTREAM *stream,char *old,char *newname);
long pop3_status (MAILSTREAM *stream,char *mbx,long flags);
MAILSTREAM *pop3_open (MAILSTREAM *stream);
long pop3_capa (MAILSTREAM *stream,long flags);
long pop3_auth (MAILSTREAM *stream,NETMBX *mb,char *pwd,char *usr);
void *pop3_challenge (void *stream,unsigned long *len);
long pop3_response (void *stream,char *s,unsigned long size);
void pop3_close (MAILSTREAM *stream,long options);
void pop3_fetchfast (MAILSTREAM *stream,char *sequence,long flags);
char *pop3_header (MAILSTREAM *stream,unsigned long msgno,unsigned long *size,
		   long flags);
long pop3_text (MAILSTREAM *stream,unsigned long msgno,STRING *bs,long flags);
unsigned long pop3_cache (MAILSTREAM *stream,MESSAGECACHE *elt);
long pop3_ping (MAILSTREAM *stream);
void pop3_check (MAILSTREAM *stream);
long pop3_expunge (MAILSTREAM *stream,char *sequence,long options);
long pop3_copy (MAILSTREAM *stream,char *sequence,char *mailbox,long options);
long pop3_append (MAILSTREAM *stream,char *mailbox,append_t af,void *data);

long pop3_send_num (MAILSTREAM *stream,char *command,unsigned long n);
long pop3_send (MAILSTREAM *stream,char *command,char *args);
long pop3_reply (MAILSTREAM *stream);
long pop3_fake (MAILSTREAM *stream,char *text);

/* POP3 mail routines */


/* Driver dispatch used by MAIL */

DRIVER pop3driver = {
  "pop3",			/* driver name */
				/* driver flags */
#ifdef INADEQUATE_MEMORY
  DR_LOWMEM |
#endif
  DR_MAIL|DR_NOFAST|DR_CRLF|DR_NOSTICKY|DR_NOINTDATE|DR_NONEWMAIL,
  (DRIVER *) NIL,		/* next driver */
  pop3_valid,			/* mailbox is valid for us */
  pop3_parameters,		/* manipulate parameters */
  pop3_scan,			/* scan mailboxes */
  pop3_list,			/* find mailboxes */
  pop3_lsub,			/* find subscribed mailboxes */
  pop3_subscribe,		/* subscribe to mailbox */
  pop3_unsubscribe,		/* unsubscribe from mailbox */
  pop3_create,			/* create mailbox */
  pop3_delete,			/* delete mailbox */
  pop3_rename,			/* rename mailbox */
  pop3_status,			/* status of mailbox */
  pop3_open,			/* open mailbox */
  pop3_close,			/* close mailbox */
  pop3_fetchfast,		/* fetch message "fast" attributes */
  NIL,				/* fetch message flags */
  NIL,				/* fetch overview */
  NIL,				/* fetch message structure */
  pop3_header,			/* fetch message header */
  pop3_text,			/* fetch message text */
  NIL,				/* fetch message */
  NIL,				/* unique identifier */
  NIL,				/* message number from UID */
  NIL,				/* modify flags */
  NIL,				/* per-message modify flags */
  NIL,				/* search for message based on criteria */
  NIL,				/* sort messages */
  NIL,				/* thread messages */
  pop3_ping,			/* ping mailbox to see if still alive */
  pop3_check,			/* check for new messages */
  pop3_expunge,			/* expunge deleted messages */
  pop3_copy,			/* copy messages to another mailbox */
  pop3_append,			/* append string message to mailbox */
  NIL				/* garbage collect stream */
};

				/* prototype stream */
MAILSTREAM pop3proto = {&pop3driver};

				/* driver parameters */
static unsigned long pop3_maxlogintrials = MAXLOGINTRIALS;
static long pop3_port = 0;
static long pop3_sslport = 0;

/* POP3 mail validate mailbox
 * Accepts: mailbox name
 * Returns: our driver if name is valid, NIL otherwise
 */

DRIVER *pop3_valid (char *name)
{
  NETMBX mb;
  return (mail_valid_net_parse (name,&mb) &&
	  !strcmp (mb.service,pop3driver.name) && !mb.authuser[0] &&
	  !compare_cstring (mb.mailbox,"INBOX")) ? &pop3driver : NIL;
}


/* News manipulate driver parameters
 * Accepts: function code
 *	    function-dependent value
 * Returns: function-dependent return value
 */

void *pop3_parameters (long function,void *value)
{
  switch ((int) function) {
  case SET_MAXLOGINTRIALS:
    pop3_maxlogintrials = (unsigned long) value;
    break;
  case GET_MAXLOGINTRIALS:
    value = (void *) pop3_maxlogintrials;
    break;
  case SET_POP3PORT:
    pop3_port = (long) value;
    break;
  case GET_POP3PORT:
    value = (void *) pop3_port;
    break;
  case SET_SSLPOPPORT:
    pop3_sslport = (long) value;
    break;
  case GET_SSLPOPPORT:
    value = (void *) pop3_sslport;
    break;
  case GET_IDLETIMEOUT:
    value = (void *) IDLETIMEOUT;
    break;
  default:
    value = NIL;		/* error case */
    break;
  }
  return value;
}

/* POP3 mail scan mailboxes for string
 * Accepts: mail stream
 *	    reference
 *	    pattern to search
 *	    string to scan
 */

void pop3_scan (MAILSTREAM *stream,char *ref,char *pat,char *contents)
{
  char tmp[MAILTMPLEN];
  if ((ref && *ref) ?		/* have a reference */
      (pop3_valid (ref) && pmatch ("INBOX",pat)) :
      (mail_valid_net (pat,&pop3driver,NIL,tmp) && pmatch ("INBOX",tmp)))
    mm_log ("Scan not valid for POP3 mailboxes",ERROR);
}


/* POP3 mail find list of all mailboxes
 * Accepts: mail stream
 *	    reference
 *	    pattern to search
 */

void pop3_list (MAILSTREAM *stream,char *ref,char *pat)
{
  char tmp[MAILTMPLEN];
  if (ref && *ref) {		/* have a reference */
    if (pop3_valid (ref) && pmatch ("INBOX",pat)) {
      strcpy (strchr (strcpy (tmp,ref),'}')+1,"INBOX");
      mm_list (stream,NIL,tmp,LATT_NOINFERIORS);
    }
  }
  else if (mail_valid_net (pat,&pop3driver,NIL,tmp) && pmatch ("INBOX",tmp)) {
    strcpy (strchr (strcpy (tmp,pat),'}')+1,"INBOX");
    mm_list (stream,NIL,tmp,LATT_NOINFERIORS);
  }
}

/* POP3 mail find list of subscribed mailboxes
 * Accepts: mail stream
 *	    reference
 *	    pattern to search
 */

void pop3_lsub (MAILSTREAM *stream,char *ref,char *pat)
{
  void *sdb = NIL;
  char *s,mbx[MAILTMPLEN];
  if (*pat == '{') {		/* if remote pattern, must be POP3 */
    if (!pop3_valid (pat)) return;
    ref = NIL;			/* good POP3 pattern, punt reference */
  }
				/* if remote reference, must be valid POP3 */
  if (ref && (*ref == '{') && !pop3_valid (ref)) return;
				/* kludgy application of reference */
  if (ref && *ref) sprintf (mbx,"%s%s",ref,pat);
  else strcpy (mbx,pat);

  if (s = sm_read (&sdb)) do if (pop3_valid (s) && pmatch (s,mbx))
    mm_lsub (stream,NIL,s,NIL);
  while (s = sm_read (&sdb));	/* until no more subscriptions */
}


/* POP3 mail subscribe to mailbox
 * Accepts: mail stream
 *	    mailbox to add to subscription list
 * Returns: T on success, NIL on failure
 */

long pop3_subscribe (MAILSTREAM *stream,char *mailbox)
{
  return sm_subscribe (mailbox);
}


/* POP3 mail unsubscribe to mailbox
 * Accepts: mail stream
 *	    mailbox to delete from subscription list
 * Returns: T on success, NIL on failure
 */

long pop3_unsubscribe (MAILSTREAM *stream,char *mailbox)
{
  return sm_unsubscribe (mailbox);
}

/* POP3 mail create mailbox
 * Accepts: mail stream
 *	    mailbox name to create
 * Returns: T on success, NIL on failure
 */

long pop3_create (MAILSTREAM *stream,char *mailbox)
{
  return NIL;			/* never valid for POP3 */
}


/* POP3 mail delete mailbox
 *	    mailbox name to delete
 * Returns: T on success, NIL on failure
 */

long pop3_delete (MAILSTREAM *stream,char *mailbox)
{
  return NIL;			/* never valid for POP3 */
}


/* POP3 mail rename mailbox
 * Accepts: mail stream
 *	    old mailbox name
 *	    new mailbox name
 * Returns: T on success, NIL on failure
 */

long pop3_rename (MAILSTREAM *stream,char *old,char *newname)
{
  return NIL;			/* never valid for POP3 */
}

/* POP3 status
 * Accepts: mail stream
 *	    mailbox name
 *	    status flags
 * Returns: T on success, NIL on failure
 */

long pop3_status (MAILSTREAM *stream,char *mbx,long flags)
{
  MAILSTATUS status;
  unsigned long i;
  long ret = NIL;
  MAILSTREAM *tstream =
    (stream && LOCAL->netstream && mail_usable_network_stream (stream,mbx)) ?
      stream : mail_open (NIL,mbx,OP_SILENT);
  if (tstream) {		/* have a usable stream? */
    status.flags = flags;	/* return status values */
    status.messages = tstream->nmsgs;
    status.recent = tstream->recent;
    if (flags & SA_UNSEEN)	/* must search to get unseen messages */
      for (i = 1,status.unseen = 0; i <= tstream->nmsgs; i++)
	if (!mail_elt (tstream,i)->seen) status.unseen++;