mbox.c

mutt-1.5.12 源代码。linux 下邮件接受的工具。

/*
 * Copyright (C) 1996-2002 Michael R. Elkins <[e-mail]>
 * 
 *     This program is free software; you can redistribute it and/or modify
 *     it under the terms of the GNU General Public License as published by
 *     the Free Software Foundation; either version 2 of the License, or
 *     (at your option) any later version.
 * 
 *     This program is distributed in the hope that it will be useful,
 *     but WITHOUT ANY WARRANTY; without even the implied warranty of
 *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *     GNU General Public License for more details.
 * 
 *     You should have received a copy of the GNU General Public License
 *     along with this program; if not, write to the Free Software
 *     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */ 

/* This file contains code to parse ``mbox'' and ``mmdf'' style mailboxes */

#if HAVE_CONFIG_H
# include "config.h"
#endif

#include "mutt.h"
#include "mailbox.h"
#include "mx.h"
#include "sort.h"
#include "copy.h"

#include <sys/stat.h>
#include <dirent.h>
#include <string.h>
#include <utime.h>
#include <sys/file.h>
#include <errno.h>
#include <unistd.h>
#include <fcntl.h>

/* struct used by mutt_sync_mailbox() to store new offsets */
struct m_update_t
{
  short valid;
  LOFF_T hdr;
  LOFF_T body;
  long lines;
  LOFF_T length;
};

/* parameters:
 * ctx - context to lock
 * excl - exclusive lock?
 * retry - should retry if unable to lock?
 */
int mbox_lock_mailbox (CONTEXT *ctx, int excl, int retry)
{
  int r;

  if ((r = mx_lock_file (ctx->path, fileno (ctx->fp), excl, 1, retry)) == 0)
    ctx->locked = 1;
  else if (retry && !excl)
  {
    ctx->readonly = 1;
    return 0;
  }
  
  return (r);
}

void mbox_unlock_mailbox (CONTEXT *ctx)
{
  if (ctx->locked)
  {
    fflush (ctx->fp);

    mx_unlock_file (ctx->path, fileno (ctx->fp), 1);
    ctx->locked = 0;
  }
}

int mmdf_parse_mailbox (CONTEXT *ctx)
{
  char buf[HUGE_STRING];
  char return_path[LONG_STRING];
  int count = 0, oldmsgcount = ctx->msgcount;
  int lines;
  time_t t, tz;
  LOFF_T loc, tmploc;
  HEADER *hdr;
  struct stat sb;
#ifdef NFS_ATTRIBUTE_HACK
  struct utimbuf newtime;
#endif

  if (stat (ctx->path, &sb) == -1)
  {
    mutt_perror (ctx->path);
    return (-1);
  }
  ctx->mtime = sb.st_mtime;
  ctx->size = sb.st_size;

#ifdef NFS_ATTRIBUTE_HACK
  if (sb.st_mtime > sb.st_atime)
  {
    newtime.modtime = sb.st_mtime;
    newtime.actime = time (NULL);
    utime (ctx->path, &newtime);
  }
#endif

  /* precompute the local timezone to speed up calculation of the
     received time */
  tz = mutt_local_tz (0);

  buf[sizeof (buf) - 1] = 0;
  
  FOREVER
  {
    if (fgets (buf, sizeof (buf) - 1, ctx->fp) == NULL)
      break;

    if (mutt_strcmp (buf, MMDF_SEP) == 0)
    {
      loc = ftello (ctx->fp);
      
      count++;
      if (!ctx->quiet && ReadInc && ((count % ReadInc == 0) || count == 1))
	mutt_message (_("Reading %s... %d (%d%%)"), ctx->path, count,
		      (int)(loc / (ctx->size / 100 + 1)));


      if (ctx->msgcount == ctx->hdrmax)
	mx_alloc_memory (ctx);
      ctx->hdrs[ctx->msgcount] = hdr = mutt_new_header ();
      hdr->offset = loc;
      hdr->index = ctx->msgcount;

      if (fgets (buf, sizeof (buf) - 1, ctx->fp) == NULL)
      {
	/* TODO: memory leak??? */
	dprint (1, (debugfile, "mmdf_parse_mailbox: unexpected EOF\n"));
	break;
      }

      return_path[0] = 0;

      if (!is_from (buf, return_path, sizeof (return_path), &t))
      {
	if (fseeko (ctx->fp, loc, SEEK_SET) != 0)
	{
	  dprint (1, (debugfile, "mmdf_parse_mailbox: fseek() failed\n"));
	  mutt_error _("Mailbox is corrupt!");
	  return (-1);
	}
      } 
      else
	hdr->received = t - tz;

      hdr->env = mutt_read_rfc822_header (ctx->fp, hdr, 0, 0);

      loc = ftello (ctx->fp);

      if (hdr->content->length > 0 && hdr->lines > 0)
      {
	tmploc = loc + hdr->content->length;

	if (0 < tmploc && tmploc < ctx->size)
	{
	  if (fseeko (ctx->fp, tmploc, SEEK_SET) != 0 ||
	      fgets (buf, sizeof (buf) - 1, ctx->fp) == NULL ||
	      mutt_strcmp (MMDF_SEP, buf) != 0)
	  {
	    if (fseeko (ctx->fp, loc, SEEK_SET) != 0)
	      dprint (1, (debugfile, "mmdf_parse_mailbox: fseek() failed\n"));
	    hdr->content->length = -1;
	  }
	}
	else
	  hdr->content->length = -1;
      }
      else
	hdr->content->length = -1;

      if (hdr->content->length < 0)
      {
	lines = -1;
	do {
	  loc = ftello (ctx->fp);
	  if (fgets (buf, sizeof (buf) - 1, ctx->fp) == NULL)
	    break;
	  lines++;
	} while (mutt_strcmp (buf, MMDF_SEP) != 0);

	hdr->lines = lines;
	hdr->content->length = loc - hdr->content->offset;
      }

      if (!hdr->env->return_path && return_path[0])
	hdr->env->return_path = rfc822_parse_adrlist (hdr->env->return_path, return_path);

      if (!hdr->env->from)
	hdr->env->from = rfc822_cpy_adr (hdr->env->return_path);

      ctx->msgcount++;
    }
    else
    {
      dprint (1, (debugfile, "mmdf_parse_mailbox: corrupt mailbox!\n"));
      mutt_error _("Mailbox is corrupt!");
      return (-1);
    }
  }

  if (ctx->msgcount > oldmsgcount)
    mx_update_context (ctx, ctx->msgcount - oldmsgcount);

  return (0);
}

/* Note that this function is also called when new mail is appended to the
 * currently open folder, and NOT just when the mailbox is initially read.
 *
 * NOTE: it is assumed that the mailbox being read has been locked before
 * this routine gets called.  Strange things could happen if it's not!
 */
int mbox_parse_mailbox (CONTEXT *ctx)
{
  struct stat sb;
  char buf[HUGE_STRING], return_path[STRING];
  HEADER *curhdr;
  time_t t, tz;
  int count = 0, lines = 0;
  LOFF_T loc;
#ifdef NFS_ATTRIBUTE_HACK
  struct utimbuf newtime;
#endif

  /* Save information about the folder at the time we opened it. */
  if (stat (ctx->path, &sb) == -1)
  {
    mutt_perror (ctx->path);
    return (-1);
  }

  ctx->size = sb.st_size;
  ctx->mtime = sb.st_mtime;

#ifdef NFS_ATTRIBUTE_HACK
  if (sb.st_mtime > sb.st_atime)
  {
    newtime.modtime = sb.st_mtime;
    newtime.actime = time (NULL);
    utime (ctx->path, &newtime);
  }
#endif

  if (!ctx->readonly)
    ctx->readonly = access (ctx->path, W_OK) ? 1 : 0;

  /* precompute the local timezone to speed up calculation of the
     date received */
  tz = mutt_local_tz (0);

  loc = ftello (ctx->fp);
  while (fgets (buf, sizeof (buf), ctx->fp) != NULL)
  {
    if (is_from (buf, return_path, sizeof (return_path), &t))
    {
      /* Save the Content-Length of the previous message */
      if (count > 0)
      {
#define PREV ctx->hdrs[ctx->msgcount-1]

	if (PREV->content->length < 0)
	{
	  PREV->content->length = loc - PREV->content->offset - 1;
	  if (PREV->content->length < 0)
	    PREV->content->length = 0;
	}
	if (!PREV->lines)
	  PREV->lines = lines ? lines - 1 : 0;
      }

      count++;

      if (!ctx->quiet && ReadInc && ((count % ReadInc == 0) || count == 1))
	mutt_message (_("Reading %s... %d (%d%%)"), ctx->path, count,
		      (int)(ftell (ctx->fp) / (ctx->size / 100 + 1)));

      if (ctx->msgcount == ctx->hdrmax)
	mx_alloc_memory (ctx);
      
      curhdr = ctx->hdrs[ctx->msgcount] = mutt_new_header ();
      curhdr->received = t - tz;
      curhdr->offset = loc;
      curhdr->index = ctx->msgcount;
	
      curhdr->env = mutt_read_rfc822_header (ctx->fp, curhdr, 0, 0);

      /* if we know how long this message is, either just skip over the body,
       * or if we don't know how many lines there are, count them now (this will
       * save time by not having to search for the next message marker).
       */
      if (curhdr->content->length > 0)
      {
	LOFF_T tmploc;

	loc = ftello (ctx->fp);
	tmploc = loc + curhdr->content->length + 1;

	if (0 < tmploc && tmploc < ctx->size)
	{
	  /*
	   * check to see if the content-length looks valid.  we expect to
	   * to see a valid message separator at this point in the stream
	   */
	  if (fseeko (ctx->fp, tmploc, SEEK_SET) != 0 ||
	      fgets (buf, sizeof (buf), ctx->fp) == NULL ||
	      mutt_strncmp ("From ", buf, 5) != 0)
	  {
	    dprint (1, (debugfile, "mbox_parse_mailbox: bad content-length in message %d (cl=" OFF_T_FMT ")\n", curhdr->index, curhdr->content->length));
	    dprint (1, (debugfile, "\tLINE: %s", buf));
	    if (fseeko (ctx->fp, loc, SEEK_SET) != 0) /* nope, return the previous position */
	    {
	      dprint (1, (debugfile, "mbox_parse_mailbox: fseek() failed\n"));
	    }
	    curhdr->content->length = -1;
	  }
	}
	else if (tmploc != ctx->size)
	{
	  /* content-length would put us past the end of the file, so it
	   * must be wrong
	   */
	  curhdr->content->length = -1;
	}

	if (curhdr->content->length != -1)
	{
	  /* good content-length.  check to see if we know how many lines
	   * are in this message.
	   */
	  if (curhdr->lines == 0)
	  {
	    int cl = curhdr->content->length;

	    /* count the number of lines in this message */
	    if (fseeko (ctx->fp, loc, SEEK_SET) != 0)
	      dprint (1, (debugfile, "mbox_parse_mailbox: fseek() failed\n"));
	    while (cl-- > 0)
	    {
	      if (fgetc (ctx->fp) == '\n')
		curhdr->lines++;
	    }
	  }

	  /* return to the offset of the next message separator */
	  if (fseeko (ctx->fp, tmploc, SEEK_SET) != 0)
	    dprint (1, (debugfile, "mbox_parse_mailbox: fseek() failed\n"));
	}
      }

      ctx->msgcount++;

      if (!curhdr->env->return_path && return_path[0])
	curhdr->env->return_path = rfc822_parse_adrlist (curhdr->env->return_path, return_path);

      if (!curhdr->env->from)
	curhdr->env->from = rfc822_cpy_adr (curhdr->env->return_path);

      lines = 0;
    }
    else
      lines++;
    
    loc = ftello (ctx->fp);
  }
  
  /*
   * Only set the content-length of the previous message if we have read more
   * than one message during _this_ invocation.  If this routine is called
   * when new mail is received, we need to make sure not to clobber what
   * previously was the last message since the headers may be sorted.
   */
  if (count > 0)
  {
    if (PREV->content->length < 0)
    {
      PREV->content->length = ftello (ctx->fp) - PREV->content->offset - 1;
      if (PREV->content->length < 0)
	PREV->content->length = 0;
    }

    if (!PREV->lines)
      PREV->lines = lines ? lines - 1 : 0;

    mx_update_context (ctx, count);
  }

  return (0);
}

#undef PREV

/* open a mbox or mmdf style mailbox */
int mbox_open_mailbox (CONTEXT *ctx)
{
  int rc;

  if ((ctx->fp = fopen (ctx->path, "r")) == NULL)
  {
    mutt_perror (ctx->path);
    return (-1);
  }
  mutt_block_signals ();
  if (mbox_lock_mailbox (ctx, 0, 1) == -1)
  {
    mutt_unblock_signals ();
    return (-1);
  }

  if (ctx->magic == M_MBOX)
    rc = mbox_parse_mailbox (ctx);
  else if (ctx->magic == M_MMDF)
    rc = mmdf_parse_mailbox (ctx);
  else
    rc = -1;

  mbox_unlock_mailbox (ctx);
  mutt_unblock_signals ();
  return (rc);
}

/* return 1 if address lists are strictly identical */
static int strict_addrcmp (const ADDRESS *a, const ADDRESS *b)
{
  while (a && b)
  {
    if (mutt_strcmp (a->mailbox, b->mailbox) ||
	mutt_strcmp (a->personal, b->personal))
      return (0);

    a = a->next;
    b = b->next;
  }
  if (a || b)
    return (0);

  return (1);
}

static int strict_cmp_lists (const LIST *a, const LIST *b)
{
  while (a && b)
  {
    if (mutt_strcmp (a->data, b->data))
      return (0);

    a = a->next;
    b = b->next;
  }
  if (a || b)
    return (0);

  return (1);
}

static int strict_cmp_envelopes (const ENVELOPE *e1, const ENVELOPE *e2)
{
  if (e1 && e2)
  {
    if (mutt_strcmp (e1->message_id, e2->message_id) ||
	mutt_strcmp (e1->subject, e2->subject) ||
	!strict_cmp_lists (e1->references, e2->references) ||
	!strict_addrcmp (e1->from, e2->from) ||
	!strict_addrcmp (e1->sender, e2->sender) ||
	!strict_addrcmp (e1->reply_to, e2->reply_to) ||
	!strict_addrcmp (e1->to, e2->to) ||
	!strict_addrcmp (e1->cc, e2->cc) ||
	!strict_addrcmp (e1->return_path, e2->return_path))
      return (0);
    else
      return (1);
  }
  else
  {
    if (e1 == NULL && e2 == NULL)
      return (1);
    else
      return (0);
  }
}

static int strict_cmp_parameters (const PARAMETER *p1, const PARAMETER *p2)
{
  while (p1 && p2)
  {
    if (mutt_strcmp (p1->attribute, p2->attribute) ||
	mutt_strcmp (p1->value, p2->value))
      return (0);

    p1 = p1->next;
    p2 = p2->next;
  }
  if (p1 || p2)
    return (0);

  return (1);
}

static int strict_cmp_bodies (const BODY *b1, const BODY *b2)
{
  if (b1->type != b2->type ||
      b1->encoding != b2->encoding ||
      mutt_strcmp (b1->subtype, b2->subtype) ||
      mutt_strcmp (b1->description, b2->description) ||
      !strict_cmp_parameters (b1->parameter, b2->parameter) ||
      b1->length != b2->length)
    return (0);
  return (1);
}

/* return 1 if headers are strictly identical */
int mbox_strict_cmp_headers (const HEADER *h1, const HEADER *h2)
{
  if (h1 && h2)
  {
    if (h1->received != h2->received ||
	h1->date_sent != h2->date_sent ||
	h1->content->length != h2->content->length ||
	h1->lines != h2->lines ||
	h1->zhours != h2->zhours ||
	h1->zminutes != h2->zminutes ||
	h1->zoccident != h2->zoccident ||
	h1->mime != h2->mime ||
	!strict_cmp_envelopes (h1->env, h2->env) ||
	!strict_cmp_bodies (h1->content, h2->content))
      return (0);
    else
      return (1);
  }
  else
  {
    if (h1 == NULL && h2 == NULL)
      return (1);
    else
      return (0);
  }
}

/* check to see if the mailbox has changed on disk.
 *
 * return values:
 *	M_REOPENED	mailbox has been reopened
 *	M_NEW_MAIL	new mail has arrived!
 *	M_LOCKED	couldn't lock the file
 *	0		no change
 *	-1		error
 */
int mbox_check_mailbox (CONTEXT *ctx, int *index_hint)
{
  struct stat st;
  char buffer[LONG_STRING];
  int unlock = 0;
  int modified = 0;

  if (stat (ctx->path, &st) == 0)
  {
    if (st.st_mtime == ctx->mtime && st.st_size == ctx->size)
      return (0);

    if (st.st_size == ctx->size)
    {
      /* the file was touched, but it is still the same length, so just exit */
      ctx->mtime = st.st_mtime;
      return (0);
    }

    if (st.st_size > ctx->size)
    {
      /* lock the file if it isn't already */
      if (!ctx->locked)
      {
	mutt_block_signals ();
	if (mbox_lock_mailbox (ctx, 0, 0) == -1)
	{
	  mutt_unblock_signals ();
	  /* we couldn't lock the mailbox, but nothing serious happened:
	   * probably the new mail arrived: no reason to wait till we can
	   * parse it: we'll get it on the next pass
	   */
	  return (M_LOCKED);
	}
	unlock = 1;
      }

      /*
       * Check to make sure that the only change to the mailbox is that 
       * message(s) were appended to this file.  My heuristic is that we should
       * see the message separator at *exactly* what used to be the end of the
       * folder.
       */
      if (fseeko (ctx->fp, ctx->size, SEEK_SET) != 0)
	dprint (1, (debugfile, "mbox_check_mailbox: fseek() failed\n"));
      if (fgets (buffer, sizeof (buffer), ctx->fp) != NULL)
      {