mix.c

广泛使用的邮件服务器！同时

/* ========================================================================
 * Copyright 1988-2008 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:	MIX mail routines
 *
 * Author(s):	Mark Crispin
 *		UW Technology
 *		University of Washington
 *		Seattle, WA  98195
 *		Internet: [e-mail]
 *
 * Date:	1 March 2006
 * Last Edited:	7 May 2008
 */


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

#define MEGABYTE (1024*1024)

#define MIXDATAROLL MEGABYTE	/* size at which we roll to a new file */


/* MIX files */

#define MIXNAME ".mix"		/* prefix for all MIX file names */
#define MIXMETA "meta"		/* suffix for metadata */
#define MIXINDEX "index"	/* suffix for index */
#define MIXSTATUS "status"	/* suffix for status */
#define MIXSORTCACHE "sortcache"/* suffix for sortcache */
#define METAMAX (MEGABYTE-1)	/* maximum metadata file size (sanity check) */


/* MIX file formats */

				/* sequence format (all but msg files) */
#define SEQFMT "S%08lx\015\012"
				/* metadata file format */
#define MTAFMT "V%08lx\015\012L%08lx\015\012N%08lx\015\012"
				/* index file record format */
#define IXRFMT ":%08lx:%04d%02d%02d%02d%02d%02d%c%02d%02d:%08lx:%08lx:%08lx:%08lx:%08lx:\015\012"
				/* status file record format */
#define STRFMT ":%08lx:%08lx:%04x:%08lx:\015\012"
				/* message file header format */
#define MSRFMT "%s%08lx:%04d%02d%02d%02d%02d%02d%c%02d%02d:%08lx:\015\012"
#define MSGTOK ":msg:"
#define MSGTSZ (sizeof(MSGTOK)-1)
				/* sortcache file record format */
#define SCRFMT ":%08lx:%08lx:%08lx:%08lx:%08lx:%c%08lx:%08lx:%08lx:\015\012"

/* MIX I/O stream local data */
	
typedef struct mix_local {
  unsigned long curmsg;		/* current message file number */
  unsigned long newmsg;		/* current new message file number */
  time_t lastsnarf;		/* last snarf time */
  int msgfd;			/* file description of current msg file */
  int mfd;			/* file descriptor of open metadata */
  unsigned long metaseq;	/* metadata sequence */
  char *index;			/* mailbox index name */
  unsigned long indexseq;	/* index sequence */
  char *status;			/* mailbox status name */
  unsigned long statusseq;	/* status sequence */
  char *sortcache;		/* mailbox sortcache name */
  unsigned long sortcacheseq;	/* sortcache sequence */
  unsigned char *buf;		/* temporary buffer */
  unsigned long buflen;		/* current size of temporary buffer */
  unsigned int expok : 1;	/* non-zero if expunge reports OK */
  unsigned int internal : 1;	/* internally opened, do not validate */
} MIXLOCAL;


#define MIXBURP struct mix_burp

MIXBURP {
  unsigned long fileno;		/* message file number */
  char *name;			/* message file name */
  SEARCHSET *tail;		/* tail of ranges */
  SEARCHSET set;		/* set of retained ranges */
  MIXBURP *next;		/* next file to burp */
};


/* Convenient access to local data */

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

DRIVER *mix_valid (char *name);
long mix_isvalid (char *name,char *meta);
void *mix_parameters (long function,void *value);
long mix_dirfmttest (char *name);
void mix_scan (MAILSTREAM *stream,char *ref,char *pat,char *contents);
long mix_scan_contents (char *name,char *contents,unsigned long csiz,
			unsigned long fsiz);
void mix_list (MAILSTREAM *stream,char *ref,char *pat);
void mix_lsub (MAILSTREAM *stream,char *ref,char *pat);
long mix_subscribe (MAILSTREAM *stream,char *mailbox);
long mix_unsubscribe (MAILSTREAM *stream,char *mailbox);
long mix_create (MAILSTREAM *stream,char *mailbox);
long mix_delete (MAILSTREAM *stream,char *mailbox);
long mix_rename (MAILSTREAM *stream,char *old,char *newname);
int mix_rselect (struct direct *name);
MAILSTREAM *mix_open (MAILSTREAM *stream);
void mix_close (MAILSTREAM *stream,long options);
void mix_abort (MAILSTREAM *stream);
char *mix_header (MAILSTREAM *stream,unsigned long msgno,unsigned long *length,
		  long flags);
long mix_text (MAILSTREAM *stream,unsigned long msgno,STRING *bs,long flags);
void mix_flag (MAILSTREAM *stream,char *sequence,char *flag,long flags);
unsigned long *mix_sort (MAILSTREAM *stream,char *charset,SEARCHPGM *spg,
			 SORTPGM *pgm,long flags);
THREADNODE *mix_thread (MAILSTREAM *stream,char *type,char *charset,
			SEARCHPGM *spg,long flags);
long mix_ping (MAILSTREAM *stream);
void mix_check (MAILSTREAM *stream);
long mix_expunge (MAILSTREAM *stream,char *sequence,long options);
int mix_select (struct direct *name);
int mix_msgfsort (const void *d1,const void *d2);
long mix_addset (SEARCHSET **set,unsigned long start,unsigned long size);
long mix_burp (MAILSTREAM *stream,MIXBURP *burp,unsigned long *reclaimed);
long mix_burp_check (SEARCHSET *set,size_t size,char *file);
long mix_copy (MAILSTREAM *stream,char *sequence,char *mailbox,
	       long options);
long mix_append (MAILSTREAM *stream,char *mailbox,append_t af,void *data);
long mix_append_msg (MAILSTREAM *stream,FILE *f,char *flags,MESSAGECACHE *delt,
		     STRING *msg,SEARCHSET *set,unsigned long seq);

FILE *mix_parse (MAILSTREAM *stream,FILE **idxf,long iflags,long sflags);
char *mix_meta_slurp (MAILSTREAM *stream,unsigned long *seq);
long mix_meta_update (MAILSTREAM *stream);
long mix_index_update (MAILSTREAM *stream,FILE *idxf,long flag);
long mix_status_update (MAILSTREAM *stream,FILE *statf,long flag);
FILE *mix_data_open (MAILSTREAM *stream,int *fd,long *size,
		     unsigned long newsize);
FILE *mix_sortcache_open (MAILSTREAM *stream);
long mix_sortcache_update (MAILSTREAM *stream,FILE **sortcache);
char *mix_read_record (FILE *f,char *buf,unsigned long buflen,char *type);
unsigned long mix_read_sequence (FILE *f);
char *mix_dir (char *dst,char *name);
char *mix_file (char *dst,char *dir,char *name);
char *mix_file_data (char *dst,char *dir,unsigned long data);
unsigned long mix_modseq (unsigned long oldseq);

/* MIX mail routines */


/* Driver dispatch used by MAIL */

DRIVER mixdriver = {
  "mix",			/* driver name */
				/* driver flags */
  DR_MAIL|DR_LOCAL|DR_NOFAST|DR_CRLF|DR_LOCKING|DR_DIRFMT|DR_MODSEQ,
  (DRIVER *) NIL,		/* next driver */
  mix_valid,			/* mailbox is valid for us */
  mix_parameters,		/* manipulate parameters */
  mix_scan,			/* scan mailboxes */
  mix_list,			/* find mailboxes */
  mix_lsub,			/* find subscribed mailboxes */
  mix_subscribe,		/* subscribe to mailbox */
  mix_unsubscribe,		/* unsubscribe from mailbox */
  mix_create,			/* create mailbox */
  mix_delete,			/* delete mailbox */
  mix_rename,			/* rename mailbox */
  mail_status_default,		/* status of mailbox */
  mix_open,			/* open mailbox */
  mix_close,			/* close mailbox */
  NIL,				/* fetch message "fast" attributes */
  NIL,				/* fetch message flags */
  NIL,				/* fetch overview */
  NIL,				/* fetch message envelopes */
  mix_header,			/* fetch message header only */
  mix_text,			/* fetch message body only */
  NIL,				/* fetch partial message test */
  NIL,				/* unique identifier */
  NIL,				/* message number */
  mix_flag,			/* modify flags */
  NIL,				/* per-message modify flags */
  NIL,				/* search for message based on criteria */
  mix_sort,			/* sort messages */
  mix_thread,			/* thread messages */
  mix_ping,			/* ping mailbox to see if still alive */
  mix_check,			/* check for new messages */
  mix_expunge,			/* expunge deleted messages */
  mix_copy,			/* copy messages to another mailbox */
  mix_append,			/* append string message to mailbox */
  NIL				/* garbage collect stream */
};

				/* prototype stream */
MAILSTREAM mixproto = {&mixdriver};

/* MIX mail validate mailbox
 * Accepts: mailbox name
 * Returns: our driver if name is valid, NIL otherwise
 */

DRIVER *mix_valid (char *name)
{
  char tmp[MAILTMPLEN];
  return mix_isvalid (name,tmp) ? &mixdriver : NIL;
}


/* MIX mail test for valid mailbox
 * Accepts: mailbox name
 *	    buffer to return meta name
 * Returns: T if valid, NIL otherwise, metadata name written in both cases
 */

long mix_isvalid (char *name,char *meta)
{
  char dir[MAILTMPLEN];
  struct stat sbuf;
				/* validate name as directory */
  if (!(errno = ((strlen (name) > NETMAXMBX) ? ENAMETOOLONG : NIL)) &&
      *mix_dir (dir,name) && mix_file (meta,dir,MIXMETA) &&
      !stat (dir,&sbuf) && ((sbuf.st_mode & S_IFMT) == S_IFDIR)) {
				/* name is directory; is it mix? */
    if (!stat (meta,&sbuf) && ((sbuf.st_mode & S_IFMT) == S_IFREG))
      return LONGT;
    else errno = NIL;		/* directory but not mix */
  }
  return NIL;
}

/* MIX manipulate driver parameters
 * Accepts: function code
 *	    function-dependent value
 * Returns: function-dependent return value
 */

void *mix_parameters (long function,void *value)
{
  void *ret = NIL;
  switch ((int) function) {
  case GET_INBOXPATH:
    if (value) ret = mailboxfile ((char *) value,"~/INBOX");
    break;
  case GET_DIRFMTTEST:
    ret = (void *) mix_dirfmttest;
    break;
  case GET_SCANCONTENTS:
    ret = (void *) mix_scan_contents;
    break;
  case SET_ONETIMEEXPUNGEATPING:
    if (value) ((MIXLOCAL *) ((MAILSTREAM *) value)->local)->expok = T;
  case GET_ONETIMEEXPUNGEATPING:
    if (value) ret = (void *)
      (((MIXLOCAL *) ((MAILSTREAM *) value)->local)->expok ? VOIDT : NIL);
    break;
  }
  return ret;
}


/* MIX test for directory format internal node
 * Accepts: candidate node name
 * Returns: T if internal name, NIL otherwise
 */

long mix_dirfmttest (char *name)
{
				/* belongs to MIX if starts with .mix */
  return strncmp (name,MIXNAME,sizeof (MIXNAME) - 1) ? NIL : LONGT;
}

/* MIX mail scan mailboxes
 * Accepts: mail stream
 *	    reference
 *	    pattern to search
 *	    string to scan
 */

void mix_scan (MAILSTREAM *stream,char *ref,char *pat,char *contents)
{
  if (stream) dummy_scan (NIL,ref,pat,contents);
}


/* MIX scan mailbox for contents
 * Accepts: mailbox name
 *	    desired contents
 *	    contents size
 *	    file size (ignored)
 * Returns: NIL if contents not found, T if found
 */

long mix_scan_contents (char *name,char *contents,unsigned long csiz,
			unsigned long fsiz)
{
  long i,nfiles;
  void *a;
  char *s;
  long ret = NIL;
  size_t namelen = strlen (name);
  struct stat sbuf;
  struct direct **names = NIL;
  if ((nfiles = scandir (name,&names,mix_select,mix_msgfsort)) > 0)
    for (i = 0; i < nfiles; ++i) {
      if (!ret) {
	sprintf (s = (char *) fs_get (namelen + strlen (names[i]->d_name) + 2),
		 "%s/%s",name,names[i]->d_name);
	if (!stat (s,&sbuf) && (csiz <= sbuf.st_size))
	  ret = dummy_scan_contents (s,contents,csiz,sbuf.st_size);
	fs_give ((void **) &s);
      }
      fs_give ((void **) &names[i]);
    }
				/* free directory list */
  if (a = (void *) names) fs_give ((void **) &a);
  return ret;
}

/* MIX list mailboxes
 * Accepts: mail stream
 *	    reference
 *	    pattern to search
 */

void mix_list (MAILSTREAM *stream,char *ref,char *pat)
{
  if (stream) dummy_list (NIL,ref,pat);
}


/* MIX list subscribed mailboxes
 * Accepts: mail stream
 *	    reference
 *	    pattern to search
 */

void mix_lsub (MAILSTREAM *stream,char *ref,char *pat)
{
  if (stream) dummy_lsub (NIL,ref,pat);
}

/* MIX mail subscribe to mailbox
 * Accepts: mail stream
 *	    mailbox to add to subscription list
 * Returns: T on success, NIL on failure
 */

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


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