news.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:	News routines
 *
 * Author:	Mark Crispin
 *		Networks and Distributed Computing
 *		Computing & Communications
 *		University of Washington
 *		Administration Building, AG-44
 *		Seattle, WA  98195
 *		Internet: [e-mail]
 *
 * Date:	4 September 1991
 * Last Edited:	30 January 2007
 */


#include <stdio.h>
#include <ctype.h>
#include <errno.h>
extern int errno;		/* just in case */
#include "mail.h"
#include "osdep.h"
#include <sys/stat.h>
#include <sys/time.h>
#include "misc.h"
#include "newsrc.h"
#include "fdstring.h"


/* news_load_message() flags */

#define NLM_HEADER 0x1		/* load message text */
#define NLM_TEXT 0x2		/* load message text */

/* NEWS I/O stream local data */
	
typedef struct news_local {
  unsigned int dirty : 1;	/* disk copy of .newsrc needs updating */
  char *dir;			/* spool directory name */
  char *name;			/* local mailbox name */
  unsigned char buf[CHUNKSIZE];	/* scratch buffer */
  unsigned long cachedtexts;	/* total size of all cached texts */
} NEWSLOCAL;


/* Convenient access to local data */

#define LOCAL ((NEWSLOCAL *) stream->local)


/* Function prototypes */

DRIVER *news_valid (char *name);
DRIVER *news_isvalid (char *name,char *mbx);
void *news_parameters (long function,void *value);
void news_scan (MAILSTREAM *stream,char *ref,char *pat,char *contents);
void news_list (MAILSTREAM *stream,char *ref,char *pat);
void news_lsub (MAILSTREAM *stream,char *ref,char *pat);
long news_canonicalize (char *ref,char *pat,char *pattern);
long news_subscribe (MAILSTREAM *stream,char *mailbox);
long news_unsubscribe (MAILSTREAM *stream,char *mailbox);
long news_create (MAILSTREAM *stream,char *mailbox);
long news_delete (MAILSTREAM *stream,char *mailbox);
long news_rename (MAILSTREAM *stream,char *old,char *newname);
MAILSTREAM *news_open (MAILSTREAM *stream);
int news_select (struct direct *name);
int news_numsort (const void *d1,const void *d2);
void news_close (MAILSTREAM *stream,long options);
void news_fast (MAILSTREAM *stream,char *sequence,long flags);
void news_flags (MAILSTREAM *stream,char *sequence,long flags);
void news_load_message (MAILSTREAM *stream,unsigned long msgno,long flags);
char *news_header (MAILSTREAM *stream,unsigned long msgno,
		   unsigned long *length,long flags);
long news_text (MAILSTREAM *stream,unsigned long msgno,STRING *bs,long flags);
void news_flagmsg (MAILSTREAM *stream,MESSAGECACHE *elt);
long news_ping (MAILSTREAM *stream);
void news_check (MAILSTREAM *stream);
long news_expunge (MAILSTREAM *stream,char *sequence,long options);
long news_copy (MAILSTREAM *stream,char *sequence,char *mailbox,long options);
long news_append (MAILSTREAM *stream,char *mailbox,append_t af,void *data);

/* News routines */


/* Driver dispatch used by MAIL */

DRIVER newsdriver = {
  "news",			/* driver name */
				/* driver flags */
  DR_NEWS|DR_READONLY|DR_NOFAST|DR_NAMESPACE|DR_NONEWMAIL|DR_DIRFMT,
  (DRIVER *) NIL,		/* next driver */
  news_valid,			/* mailbox is valid for us */
  news_parameters,		/* manipulate parameters */
  news_scan,			/* scan mailboxes */
  news_list,			/* find mailboxes */
  news_lsub,			/* find subscribed mailboxes */
  news_subscribe,		/* subscribe to mailbox */
  news_unsubscribe,		/* unsubscribe from mailbox */
  news_create,			/* create mailbox */
  news_delete,			/* delete mailbox */
  news_rename,			/* rename mailbox */
  mail_status_default,		/* status of mailbox */
  news_open,			/* open mailbox */
  news_close,			/* close mailbox */
  news_fast,			/* fetch message "fast" attributes */
  news_flags,			/* fetch message flags */
  NIL,				/* fetch overview */
  NIL,				/* fetch message envelopes */
  news_header,			/* fetch message header */
  news_text,			/* fetch message body */
  NIL,				/* fetch partial message text */
  NIL,				/* unique identifier */
  NIL,				/* message number */
  NIL,				/* modify flags */
  news_flagmsg,			/* per-message modify flags */
  NIL,				/* search for message based on criteria */
  NIL,				/* sort messages */
  NIL,				/* thread messages */
  news_ping,			/* ping mailbox to see if still alive */
  news_check,			/* check for new messages */
  news_expunge,			/* expunge deleted messages */
  news_copy,			/* copy messages to another mailbox */
  news_append,			/* append string message to mailbox */
  NIL				/* garbage collect stream */
};

				/* prototype stream */
MAILSTREAM newsproto = {&newsdriver};

/* News validate mailbox
 * Accepts: mailbox name
 * Returns: our driver if name is valid, NIL otherwise
 */

DRIVER *news_valid (char *name)
{
  int fd;
  char *s,*t,*u;
  struct stat sbuf;
  if ((name[0] == '#') && (name[1] == 'n') && (name[2] == 'e') &&
      (name[3] == 'w') && (name[4] == 's') && (name[5] == '.') &&
      !strchr (name,'/') &&
      !stat ((char *) mail_parameters (NIL,GET_NEWSSPOOL,NIL),&sbuf) &&
      ((fd = open ((char *) mail_parameters (NIL,GET_NEWSACTIVE,NIL),O_RDONLY,
		   NIL)) >= 0)) {
    fstat (fd,&sbuf);		/* get size of active file */
				/* slurp in active file */
    read (fd,t = s = (char *) fs_get (sbuf.st_size+1),sbuf.st_size);
    s[sbuf.st_size] = '\0';	/* tie off file */
    close (fd);			/* flush file */
    while (*t && (u = strchr (t,' '))) {
      *u++ = '\0';		/* tie off at end of name */
      if (!strcmp (name+6,t)) {
	fs_give ((void **) &s);	/* flush data */
	return &newsdriver;
      }
      t = 1 + strchr (u,'\n');	/* next line */
    }
    fs_give ((void **) &s);	/* flush data */
  }
  return NIL;			/* return status */
}

/* News manipulate driver parameters
 * Accepts: function code
 *	    function-dependent value
 * Returns: function-dependent return value
 */

void *news_parameters (long function,void *value)
{
  return (function == GET_NEWSRC) ? env_parameters (function,value) : NIL;
}


/* News scan mailboxes
 * Accepts: mail stream
 *	    reference
 *	    pattern to search
 *	    string to scan
 */

void news_scan (MAILSTREAM *stream,char *ref,char *pat,char *contents)
{
  char tmp[MAILTMPLEN];
  if (news_canonicalize (ref,pat,tmp))
    mm_log ("Scan not valid for news mailboxes",ERROR);
}

/* News find list of newsgroups
 * Accepts: mail stream
 *	    reference
 *	    pattern to search
 */

void news_list (MAILSTREAM *stream,char *ref,char *pat)
{
  int fd;
  int i;
  char *s,*t,*u,*r,pattern[MAILTMPLEN],name[MAILTMPLEN];
  struct stat sbuf;
  if (!pat || !*pat) {		/* empty pattern? */
    if (news_canonicalize (ref,"*",pattern)) {
				/* tie off name at root */
      if (s = strchr (pattern,'.')) *++s = '\0';
      else pattern[0] = '\0';
      mm_list (stream,'.',pattern,LATT_NOSELECT);
    }
  }
  else if (news_canonicalize (ref,pat,pattern) &&
	   !stat ((char *) mail_parameters (NIL,GET_NEWSSPOOL,NIL),&sbuf) &&
	   ((fd = open ((char *) mail_parameters (NIL,GET_NEWSACTIVE,NIL),
			O_RDONLY,NIL)) >= 0)) {
    fstat (fd,&sbuf);		/* get file size and read data */
    read (fd,s = (char *) fs_get (sbuf.st_size + 1),sbuf.st_size);
    close (fd);			/* close file */
    s[sbuf.st_size] = '\0';	/* tie off string */
    strcpy (name,"#news.");	/* write initial prefix */
    i = strlen (pattern);	/* length of pattern */
    if (pattern[--i] != '%') i = 0;
    if (t = strtok_r (s,"\n",&r)) do if (u = strchr (t,' ')) {
      *u = '\0';		/* tie off at end of name */
      strcpy (name + 6,t);	/* make full form of name */
      if (pmatch_full (name,pattern,'.')) mm_list (stream,'.',name,NIL);
      else if (i && (u = strchr (name + i,'.'))) {
	*u = '\0';		/* tie off at delimiter, see if matches */
	if (pmatch_full (name,pattern,'.'))
	  mm_list (stream,'.',name,LATT_NOSELECT);
      }
    } while (t = strtok_r (NIL,"\n",&r));
    fs_give ((void **) &s);
  }
}

/* News find list of subscribed newsgroups
 * Accepts: mail stream
 *	    reference
 *	    pattern to search
 */

void news_lsub (MAILSTREAM *stream,char *ref,char *pat)
{
  char pattern[MAILTMPLEN];
				/* return data from newsrc */
  if (news_canonicalize (ref,pat,pattern)) newsrc_lsub (stream,pattern);
}


/* News canonicalize newsgroup name
 * Accepts: reference
 *	    pattern
 *	    returned single pattern
 * Returns: T on success, NIL on failure
 */

long news_canonicalize (char *ref,char *pat,char *pattern)
{
  unsigned long i;
  char *s;
  if (ref && *ref) {		/* have a reference */
    strcpy (pattern,ref);	/* copy reference to pattern */
				/* # overrides mailbox field in reference */
    if (*pat == '#') strcpy (pattern,pat);
				/* pattern starts, reference ends, with . */
    else if ((*pat == '.') && (pattern[strlen (pattern) - 1] == '.'))
      strcat (pattern,pat + 1);	/* append, omitting one of the period */
    else strcat (pattern,pat);	/* anything else is just appended */
  }
  else strcpy (pattern,pat);	/* just have basic name */
  if ((pattern[0] == '#') && (pattern[1] == 'n') && (pattern[2] == 'e') &&
      (pattern[3] == 'w') && (pattern[4] == 's') && (pattern[5] == '.') &&
      !strchr (pattern,'/')) {	/* count wildcards */
    for (i = 0, s = pattern; *s; *s++) if ((*s == '*') || (*s == '%')) ++i;
				/* success if not too many */
    if (i <= MAXWILDCARDS) return LONGT;
    MM_LOG ("Excessive wildcards in LIST/LSUB",ERROR);
  }
  return NIL;
}

/* News subscribe to mailbox
 * Accepts: mail stream
 *	    mailbox to add to subscription list
 * Returns: T on success, NIL on failure
 */

long news_subscribe (MAILSTREAM *stream,char *mailbox)
{
  return news_valid (mailbox) ? newsrc_update (stream,mailbox+6,':') : NIL;
}


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

long news_unsubscribe (MAILSTREAM *stream,char *mailbox)
{
  return news_valid (mailbox) ? newsrc_update (stream,mailbox+6,'!') : NIL;
}

/* News create mailbox
 * Accepts: mail stream
 *	    mailbox name to create
 * Returns: T on success, NIL on failure
 */

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


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

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


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

long news_rename (MAILSTREAM *stream,char *old,char *newname)
{
  return NIL;			/* never valid for News */
}

/* News open
 * Accepts: stream to open
 * Returns: stream on success, NIL on failure
 */

MAILSTREAM *news_open (MAILSTREAM *stream)
{
  long i,nmsgs;
  char *s,tmp[MAILTMPLEN];
  struct direct **names = NIL;
  				/* return prototype for OP_PROTOTYPE call */
  if (!stream) return &newsproto;
  if (stream->local) fatal ("news recycle stream");
				/* build directory name */
  sprintf (s = tmp,"%s/%s",(char *) mail_parameters (NIL,GET_NEWSSPOOL,NIL),
	   stream->mailbox + 6);
  while (s = strchr (s,'.')) *s = '/';
				/* scan directory */
  if ((nmsgs = scandir (tmp,&names,news_select,news_numsort)) >= 0) {