path: root/camel/providers/imap/camel-imap-command.c

/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
/* camel-imap-command.c: IMAP command sending/parsing routines */

/*
 *  Authors:
 *    Dan Winship <danw@helixcode.com>
 *    Jeffrey Stedfast <fejj@helixcode.com>
 *
 *  Copyright 2000 Helix Code, Inc. (www.helixcode.com)
 *
 *  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., 59 Temple Street #330, Boston, MA 02111-1307, USA.
 *
 */


#include <config.h>

#include <stdio.h>
#include <string.h>

#include "camel-imap-command.h"
#include "camel-imap-utils.h"
#include "camel-imap-folder.h"
#include <camel/camel-exception.h>

static char *imap_read_untagged (CamelImapStore *store, char *line,
                 CamelException *ex);
static CamelImapResponse *imap_read_response (CamelImapStore *store,
                          CamelException *ex);

/**
 * camel_imap_command: Send a command to a IMAP server and get a response
 * @store: the IMAP store
 * @folder: The folder to perform the operation in (or %NULL if not
 * relevant).
 * @ex: a CamelException
 * @fmt: a printf-style format string, followed by arguments
 *
 * This function makes sure that @folder (if non-%NULL) is the
 * currently-selected folder on @store and then sends the IMAP command
 * specified by @fmt and the following arguments. It then reads the
 * server's response(s) and parses the final result.
 *
 * As a special case, if @fmt is %NULL, it will just select @folder
 * and return the response from doing so.
 * 
 * Return value: %NULL if an error occurred (in which case @ex will
 * be set). Otherwise, a CamelImapResponse describing the server's
 * response, which the caller must free with camel_imap_response_free().
 **/
CamelImapResponse *
camel_imap_command (CamelImapStore *store, CamelFolder *folder,
            CamelException *ex, const char *fmt, ...)
{
    gchar *cmdbuf;
    va_list ap;

    /* Check for current folder */
    if (folder && (!fmt || folder != store->current_folder)) {
        char *folder_path;
        CamelImapResponse *response;

        folder_path = camel_imap_store_folder_path (store,
                                folder->full_name);
        store->current_folder = NULL;
        response = camel_imap_command (store, NULL, ex,
                           "SELECT \"%s\"", folder_path);
        g_free (folder_path);

        if (!response)
            return NULL;
        store->current_folder = folder;

        if (!fmt)
            return response;

        camel_imap_response_free (response);
    }

    /* Send the command */
    va_start (ap, fmt);
    cmdbuf = g_strdup_vprintf (fmt, ap);
    va_end (ap);

    camel_remote_store_send_string (CAMEL_REMOTE_STORE (store), ex,
                    "A%.5d %s\r\n", store->command++,
                    cmdbuf);
    g_free (cmdbuf);
    if (camel_exception_is_set (ex))
        return NULL;

    /* Read the response. */
    return imap_read_response (store, ex);
}

/**
 * camel_imap_command_continuation: Send more command data to the IMAP server
 * @store: the IMAP store
 * @ex: a CamelException
 * @cmdbuf: buffer containing the response/request data
 *
 * This method is for sending continuing responses to the IMAP server
 * after camel_imap_command returns a CAMEL_IMAP_PLUS response.
 * 
 * Return value: as for camel_imap_command()
 **/
CamelImapResponse *
camel_imap_command_continuation (CamelImapStore *store, CamelException *ex,
                 const char *cmdbuf)
{
    if (camel_remote_store_send_string (CAMEL_REMOTE_STORE (store), ex,
                        "%s\r\n", cmdbuf) < 0)
        return NULL;

    return imap_read_response (store, ex);
}

/* Read the response to an IMAP command. */
static CamelImapResponse *
imap_read_response (CamelImapStore *store, CamelException *ex)
{
    CamelImapResponse *response;
    int number, exists = 0;
    GArray *expunged = NULL;
    char *respbuf, *retcode, *word, *p;

    /* Read first line */
    if (camel_remote_store_recv_line (CAMEL_REMOTE_STORE (store),
                      &respbuf, ex) < 0)
        return NULL;

    response = g_new0 (CamelImapResponse, 1);
    response->untagged = g_ptr_array_new ();

    /* Check for untagged data */
    while (!strncmp (respbuf, "* ", 2)) {
        /* Read the rest of the response if it is multi-line. */
        respbuf = imap_read_untagged (store, respbuf, ex);
        if (camel_exception_is_set (ex))
            break;

        /* If it starts with a number, we might deal with
         * it ourselves.
         */
        word = imap_next_word (respbuf);
        number = strtoul (word, &p, 10);
        if (p != word && store->current_folder) {
            word = imap_next_word (p);
            if (!g_strcasecmp (word, "EXISTS")) {
                exists = number;
                g_free (respbuf);
                goto next;
            } else if (!g_strcasecmp (word, "EXPUNGE")) {
                if (!expunged) {
                    expunged = g_array_new (FALSE, FALSE,
                                sizeof (int));
                }
                g_array_append_val (expunged, number);
                g_free (respbuf);
                goto next;
            }
        } else {
            if (!g_strncasecmp (word, "BYE", 3)) {
                /* connection was lost, no more data to fetch */
                store->connected = FALSE;
                g_free (respbuf);
                respbuf = NULL;
                break;
            }
        }

        g_ptr_array_add (response->untagged, respbuf);
    next:
        if (camel_remote_store_recv_line (
            CAMEL_REMOTE_STORE (store), &respbuf, ex) < 0)
            break;
    }

    /* Update the summary */
    if (store->current_folder && (exists > 0 || expunged)) {
        camel_imap_folder_changed (store->current_folder, exists,
                       expunged, NULL);
    }
    if (expunged)
        g_array_free (expunged, TRUE);

    if (!respbuf || camel_exception_is_set (ex)) {
        camel_imap_response_free (response);
        return NULL;
    }

    response->status = respbuf;

    /* Check for OK or continuation response. */
    if (!strncmp (respbuf, "+ ", 2))
        return response;
    retcode = imap_next_word (respbuf);
    if (!strncmp (retcode, "OK", 2))
        return response;

    /* We should never get BAD, or anything else but +, OK, or NO
     * for that matter.
     */
    if (strncmp (retcode, "NO", 2) != 0) {
        g_warning ("Unexpected response from IMAP server: %s",
               respbuf);
        camel_exception_setv (ex, CAMEL_EXCEPTION_SERVICE_UNAVAILABLE,
                      "Unexpected response from IMAP server: "
                      "%s", respbuf);
        camel_imap_response_free (response);
        return NULL;
    }

    retcode = imap_next_word (retcode);
    camel_exception_setv (ex, CAMEL_EXCEPTION_SERVICE_UNAVAILABLE,
                  "IMAP command failed: %s",
                  retcode ? retcode : "Unknown error");
    camel_imap_response_free (response);
    return NULL;
}

/* Given a line that is the start of an untagged response, read and
 * return the complete response. (This will be a no-op if the line
 * in question doesn't end with a literal.)
 *
 * FIXME: this won't deal with multiple literals in a single response.
 */
static char *
imap_read_untagged (CamelImapStore *store, char *line, CamelException *ex)
{
    int fulllen, length, left, i;
    GPtrArray *data;
    char *end, *p;

    p = strrchr (line, '{');
    if (!p)
        return line;

    length = strtoul (p + 1, &end, 10);
    if (*end != '}' || *(end + 1) || end == p + 1)
        return line;

    fulllen = length + strlen (line) + 1;

    /* OK. We have a literal. @length is the length including CRLF
     * pairs, which camel_remote_store_recv_line won't return.
     */
    data = g_ptr_array_new ();
    g_ptr_array_add (data, line);
    left = length;
    while (1) {
        if (camel_remote_store_recv_line (CAMEL_REMOTE_STORE (store),
                          &line, ex) < 0) {
            for (i = 0; i < data->len; i++)
                g_free (data->pdata[i]);
            g_ptr_array_free (data, TRUE);
            return NULL;
        }
        g_ptr_array_add (data, line);

        if (left <= 0)
            break;

        left -= strlen (line) + 2;

        /* The output string will have only LF, not CRLF, so
         * decrement the length by one.
         */
        length--;
    }

    /* Add the length of the post-literal line. */
    fulllen += strlen (line);

    /* p points to the "{" in the line that starts the literal.
     * The length of the CR-less response must be less than or
     * equal to the length of the response with CRs, therefore
     * overwriting the old value with the new value cannot cause
     * an overrun.
     */
    sprintf (p, "{%d}", length);

    /* Now reassemble the data. */
    p = line = g_malloc (fulllen + 1);
    for (i = 0; i < data->len; i++) {
        length = strlen (data->pdata[i]);
        memcpy (p, data->pdata[i], length);
        g_free (data->pdata[i]);
        p += length;
        *p++ = '\n';
    }
    *p = '\0';
    g_ptr_array_free (data, TRUE);
    return line;
}


/**
 * camel_imap_response_free:
 * response: a CamelImapResponse:
 *
 * Frees all of the data in @response.
 **/
void
camel_imap_response_free (CamelImapResponse *response)
{
    int i;

    if (!response)
        return;
    for (i = 0; i < response->untagged->len; i++)
        g_free (response->untagged->pdata[i]);
    g_ptr_array_free (response->untagged, TRUE);
    g_free (response->status);
    g_free (response);
}

/**
 * camel_imap_response_extract:
 * @response: the response data returned from camel_imap_command
 * @type: the response type to extract
 * @ex: a CamelException
 *
 * This checks that @response contains a single untagged response of
 * type @type and returns just that response data. If @response
 * doesn't contain the right information, the function will set @ex and
 * return %NULL. Either way, @response will be freed.
 *
 * Return value: the desired response string, which the caller must free.
 **/
char *
camel_imap_response_extract (CamelImapResponse *response, const char *type,
                 CamelException *ex)
{
    int len = strlen (type), i;
    char *resp;

    for (i = 0; i < response->untagged->len; i++) {
        resp = response->untagged->pdata[i];
        /* Skip "* ", and initial sequence number, if present */
        strtoul (resp + 2, &resp, 10);
        if (*resp == ' ')
            resp = imap_next_word (resp);

        if (!g_strncasecmp (resp, type, len))
            break;
        
        g_free (response->untagged->pdata[i]);
    }

    if (i < response->untagged->len) {
        resp = response->untagged->pdata[i];
        for (i++; i < response->untagged->len; i++)
            g_free (response->untagged->pdata[i]);
    } else {
        resp = NULL;
        camel_exception_setv (ex, CAMEL_EXCEPTION_SERVICE_UNAVAILABLE,
                      "IMAP server response did not contain "
                      "%s information", type);
    }

    g_ptr_array_free (response->untagged, TRUE);
    g_free (response->status);
    g_free (response);
    return resp;
}

/**
 * camel_imap_response_extract_continuation:
 * @response: the response data returned from camel_imap_command
 * @ex: a CamelException
 *
 * This checks that @response contains a continuation response, and
 * returns just that data. If @response doesn't contain a continuation
 * response, the function will set @ex and return %NULL. Either way,
 * @response will be freed.
 *
 * Return value: the desired response string, which the caller must free.
 **/
char *
camel_imap_response_extract_continuation (CamelImapResponse *response,
                      CamelException *ex)
{
    char *status;

    if (response->status && !strncmp (response->status, "+ ", 2)) {
        status = response->status;
        response->status = NULL;
        camel_imap_response_free (response);
        return status;
    }

    camel_exception_setv (ex, CAMEL_EXCEPTION_SERVICE_UNAVAILABLE,
                  "Unexpected OK response from IMAP server: %s",
                  response->status);
    camel_imap_response_free (response);
    return NULL;
}