imap.c

mutt-1.5.12 源代码。linux 下邮件接受的工具。

/*
 * Copyright (C) 1996-8 Michael R. Elkins <[e-mail]>
 * Copyright (C) 1996-9 Brandon Long <[e-mail]>
 * Copyright (C) 1999-2006 Brendan Cully <[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.
 */ 

/* Support for IMAP4rev1, with the occasional nod to IMAP 4. */

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

#include "mutt.h"
#include "mx.h"
#include "mailbox.h"
#include "globals.h"
#include "sort.h"
#include "browser.h"
#include "message.h"
#include "imap_private.h"
#if defined(USE_SSL)
# include "mutt_ssl.h"
#endif
#include "buffy.h"
#if USE_HCACHE
#include "hcache.h"
#endif

#include <unistd.h>
#include <ctype.h>
#include <string.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>

/* imap forward declarations */
static char* imap_get_flags (LIST** hflags, char* s);
static int imap_check_capabilities (IMAP_DATA* idata);
static void imap_set_flag (IMAP_DATA* idata, int aclbit, int flag,
			   const char* str, char* flags, size_t flsize);

/* imap_access: Check permissions on an IMAP mailbox.
 * TODO: ACL checks. Right now we assume if it exists we can
 *       mess with it. */
int imap_access (const char* path, int flags)
{
  IMAP_DATA* idata;
  IMAP_MBOX mx;
  char buf[LONG_STRING];
  char mailbox[LONG_STRING];
  char mbox[LONG_STRING];

  if (imap_parse_path (path, &mx))
    return -1;

  if (!(idata = imap_conn_find (&mx.account,
    option (OPTIMAPPASSIVE) ? M_IMAP_CONN_NONEW : 0)))
  {
    FREE (&mx.mbox);
    return -1;
  }

  imap_fix_path (idata, mx.mbox, mailbox, sizeof (mailbox));

  /* we may already be in the folder we're checking */
  if (!ascii_strcmp(idata->mailbox, mx.mbox))
  {
    FREE (&mx.mbox);
    return 0;
  }

  FREE (&mx.mbox);
  imap_munge_mbox_name (mbox, sizeof (mbox), mailbox);

  if (mutt_bit_isset (idata->capabilities, IMAP4REV1))
    snprintf (buf, sizeof (buf), "STATUS %s (UIDVALIDITY)", mbox);
  else if (mutt_bit_isset (idata->capabilities, STATUS))
    snprintf (buf, sizeof (buf), "STATUS %s (UID-VALIDITY)", mbox);
  else
  {
    dprint (2, (debugfile, "imap_access: STATUS not supported?\n"));
    return -1;
  }

  if (imap_exec (idata, buf, IMAP_CMD_FAIL_OK) < 0)
  {
    dprint (1, (debugfile, "imap_access: Can't check STATUS of %s\n", mbox));
    return -1;
  }

  return 0;
}

int imap_create_mailbox (IMAP_DATA* idata, char* mailbox)
{
  char buf[LONG_STRING], mbox[LONG_STRING];

  imap_munge_mbox_name (mbox, sizeof (mbox), mailbox);
  snprintf (buf, sizeof (buf), "CREATE %s", mbox);
      
  if (imap_exec (idata, buf, 0) != 0)
    return -1;

  return 0;
}

int imap_rename_mailbox (IMAP_DATA* idata, IMAP_MBOX* mx, const char* newname)
{
  char oldmbox[LONG_STRING];
  char newmbox[LONG_STRING];
  char buf[LONG_STRING];

  imap_munge_mbox_name (oldmbox, sizeof (oldmbox), mx->mbox);
  imap_munge_mbox_name (newmbox, sizeof (newmbox), newname);

  snprintf (buf, sizeof (buf), "RENAME %s %s", oldmbox, newmbox);

  if (imap_exec (idata, buf, 0) != 0)
    return -1;

  return 0;
}

int imap_delete_mailbox (CONTEXT* ctx, IMAP_MBOX mx)
{
  char buf[LONG_STRING], mbox[LONG_STRING];
  IMAP_DATA *idata;

  if (!ctx || !ctx->data) {
    if (!(idata = imap_conn_find (&mx.account,
          option (OPTIMAPPASSIVE) ? M_IMAP_CONN_NONEW : 0)))
    {
      FREE (&mx.mbox);
      return -1;
    }
  } else {
    idata = ctx->data;
  }

  imap_munge_mbox_name (mbox, sizeof (mbox), mx.mbox);
  snprintf (buf, sizeof (buf), "DELETE %s", mbox);

  if (imap_exec ((IMAP_DATA*) idata, buf, 0) != 0)
    return -1;

  return 0;
}

/* imap_logout_all: close all open connections. Quick and dirty until we can
 *   make sure we've got all the context we need. */
void imap_logout_all (void) 
{
  CONNECTION* conn;
  CONNECTION* tmp;

  conn = mutt_socket_head ();

  while (conn)
  {
    tmp = conn->next;

    if (conn->account.type == M_ACCT_TYPE_IMAP && conn->fd >= 0)
    {
      mutt_message (_("Closing connection to %s..."), conn->account.host);
      imap_logout ((IMAP_DATA*) conn->data);
      mutt_clear_error ();
      mutt_socket_close (conn);
      mutt_socket_free (conn);
    }

    conn = tmp;
  }
}

/* imap_read_literal: read bytes bytes from server into file. Not explicitly
 *   buffered, relies on FILE buffering. NOTE: strips \r from \r\n.
 *   Apparently even literals use \r\n-terminated strings ?! */
int imap_read_literal (FILE* fp, IMAP_DATA* idata, long bytes, progress_t* pbar)
{
  long pos;
  char c;

  int r = 0;

  dprint (2, (debugfile, "imap_read_literal: reading %ld bytes\n", bytes));
 
  for (pos = 0; pos < bytes; pos++)
  {
    if (mutt_socket_readchar (idata->conn, &c) != 1)
    {
      dprint (1, (debugfile, "imap_read_literal: error during read, %ld bytes read\n", pos));
      idata->status = IMAP_FATAL;
      
      return -1;
    }

#if 1
    if (r == 1 && c != '\n')
      fputc ('\r', fp);

    if (c == '\r')
    {
      r = 1;
      continue;
    }
    else
      r = 0;
#endif
    fputc (c, fp);
    
    if (pbar && !(pos % 1024))
      mutt_progress_bar (pbar, pos);
#ifdef DEBUG
    if (debuglevel >= IMAP_LOG_LTRL)
      fputc (c, debugfile);
#endif
  }

  return 0;
}

/* imap_expunge_mailbox: Purge IMAP portion of expunged messages from the
 *   context. Must not be done while something has a handle on any headers
 *   (eg inside pager or editor). That is, check IMAP_REOPEN_ALLOW. */
void imap_expunge_mailbox (IMAP_DATA* idata)
{
  HEADER* h;
  int i, cacheno;

#if USE_HCACHE
  header_cache_t *hc;
  char uidbuf[32];
  
  hc = mutt_hcache_open (HeaderCache, idata->ctx->path);
#endif

  for (i = 0; i < idata->ctx->msgcount; i++)
  {
    h = idata->ctx->hdrs[i];

    if (h->index == -1)
    {
      dprint (2, (debugfile, "Expunging message UID %d.\n", HEADER_DATA (h)->uid));

      h->active = 0;

      imap_cache_del (idata, h);
#if USE_HCACHE
      if (hc)
      {
        sprintf (uidbuf, "/%u", HEADER_DATA(h)->uid);
        mutt_hcache_delete (hc, uidbuf, imap_hcache_keylen);
      }
#endif

      /* free cached body from disk, if necessary */
      cacheno = HEADER_DATA(h)->uid % IMAP_CACHE_LEN;
      if (idata->cache[cacheno].uid == HEADER_DATA(h)->uid &&
	  idata->cache[cacheno].path)
      {
	unlink (idata->cache[cacheno].path);
	FREE (&idata->cache[cacheno].path);
      }

      imap_free_header_data (&h->data);
    }
  }

#if USE_HCACHE
  mutt_hcache_close (hc);
#endif

  /* We may be called on to expunge at any time. We can't rely on the caller
   * to always know to rethread */
  mx_update_tables (idata->ctx, 0);
  mutt_sort_headers (idata->ctx, 1);
}

/* imap_check_capabilities: make sure we can log in to this server. */
static int imap_check_capabilities (IMAP_DATA* idata)
{
  if (imap_exec (idata, "CAPABILITY", 0) != 0)
  {
    imap_error ("imap_check_capabilities", idata->buf);
    return -1;
  }

  if (!(mutt_bit_isset(idata->capabilities,IMAP4)
      ||mutt_bit_isset(idata->capabilities,IMAP4REV1)))
  {
    mutt_error _("This IMAP server is ancient. Mutt does not work with it.");
    mutt_sleep (2);	/* pause a moment to let the user see the error */

    return -1;
  }

  return 0;
}

/* imap_conn_find: Find an open IMAP connection matching account, or open
 *   a new one if none can be found. */
IMAP_DATA* imap_conn_find (const ACCOUNT* account, int flags)
{
  CONNECTION* conn = NULL;
  ACCOUNT* creds = NULL;
  IMAP_DATA* idata = NULL;
  int new = 0;

  while ((conn = mutt_conn_find (conn, account)))
  {
    if (!creds)
      creds = &conn->account;
    else
      memcpy (&conn->account, creds, sizeof (ACCOUNT));

    idata = (IMAP_DATA*)conn->data;
    if (flags & M_IMAP_CONN_NONEW)
    {
      if (!idata)
      {
        /* This should only happen if we've come to the end of the list */
        mutt_socket_free (conn);
        return NULL;
      }
      else if (idata->state < IMAP_AUTHENTICATED)
        continue;
    }
    if (flags & M_IMAP_CONN_NOSELECT && idata && idata->state >= IMAP_SELECTED)
      continue;
    break;
  }

  if (!idata)
  {
    /* The current connection is a new connection */
    if (! (idata = imap_new_idata ()))
    {
      mutt_socket_free (conn);
      return NULL;
    }

    conn->data = idata;
    idata->conn = conn;
    new = 1;
  }

  if (idata->state == IMAP_DISCONNECTED)
    imap_open_connection (idata);
  if (idata->state == IMAP_CONNECTED)
  {
    if (!imap_authenticate (idata))
    {
      idata->state = IMAP_AUTHENTICATED;
      if (idata->conn->ssf)
	dprint (2, (debugfile, "Communication encrypted at %d bits\n",
		    idata->conn->ssf));
    }
    else
      mutt_account_unsetpass (&idata->conn->account);
    
    FREE (&idata->capstr);
  }
  if (new && idata->state == IMAP_AUTHENTICATED)
  {
    /* get root delimiter, '/' as default */
    idata->delim = '/';
    imap_cmd_queue (idata, "LIST \"\" \"\"");
    if (option (OPTIMAPCHECKSUBSCRIBED))
      imap_cmd_queue (idata, "LSUB \"\" \"*\"");
    /* we may need the root delimiter before we open a mailbox */
    imap_exec (idata, NULL, IMAP_CMD_FAIL_OK);
  }

  return idata;
}

int imap_open_connection (IMAP_DATA* idata)
{
  char buf[LONG_STRING];

  if (mutt_socket_open (idata->conn) < 0)
    return -1;

  idata->state = IMAP_CONNECTED;

  if (imap_cmd_step (idata) != IMAP_CMD_CONTINUE)
  {
    mutt_socket_close (idata->conn);
    idata->state = IMAP_DISCONNECTED;
    return -1;
  }

  if (ascii_strncasecmp ("* OK", idata->buf, 4) == 0)
  {
    if (ascii_strncasecmp ("* OK [CAPABILITY", idata->buf, 16)
        && imap_check_capabilities (idata))
      goto bail;
#if defined(USE_SSL)
    /* Attempt STARTTLS if available and desired. */
    if (!idata->conn->ssf && (option(OPTSSLFORCETLS) ||
                              mutt_bit_isset (idata->capabilities, STARTTLS)))
    {
      int rc;
      
      if (option(OPTSSLFORCETLS))
        rc = M_YES;
      else if ((rc = query_quadoption (OPT_SSLSTARTTLS,
        _("Secure connection with TLS?"))) == -1)
	goto err_close_conn;
      if (rc == M_YES) {
	if ((rc = imap_exec (idata, "STARTTLS", IMAP_CMD_FAIL_OK)) == -1)
	  goto bail;
	if (rc != -2)
	{
	  if (mutt_ssl_starttls (idata->conn))
	  {
	    mutt_error (_("Could not negotiate TLS connection"));
	    mutt_sleep (1);
	    goto err_close_conn;
	  }
	  else
	  {
	    /* RFC 2595 demands we recheck CAPABILITY after TLS completes. */
	    if (imap_exec (idata, "CAPABILITY", 0))
	      goto bail;
	  }
	}
      }
    }

    if (option(OPTSSLFORCETLS) && ! idata->conn->ssf)
    {
      mutt_error _("Encrypted connection unavailable");
      mutt_sleep (1);
      goto err_close_conn;
    }
#endif    
  }
  else if (ascii_strncasecmp ("* PREAUTH", idata->buf, 9) == 0)
  {
    idata->state = IMAP_AUTHENTICATED;
    if (imap_check_capabilities (idata) != 0)
      goto bail;
    FREE (&idata->capstr);
  } 
  else
  {
    imap_error ("imap_open_connection()", buf);
    goto bail;
  }

  return 0;

#if defined(USE_SSL)
 err_close_conn:
  mutt_socket_close (idata->conn);
  idata->state = IMAP_DISCONNECTED;
#endif
 bail:
  FREE (&idata->capstr);
  return -1;
}

/* imap_get_flags: Make a simple list out of a FLAGS response.
 *   return stream following FLAGS response */
static char* imap_get_flags (LIST** hflags, char* s)
{
  LIST* flags;
  char* flag_word;
  char ctmp;