path: root/mail/e-http-request.c

/*
 * e-http-request.c
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) version 3.
 *
 * 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with the program; if not, see <http://www.gnu.org/licenses/>
 *
 */

#include "e-http-request.h"

#define LIBSOUP_USE_UNSTABLE_REQUEST_API
#include <libsoup/soup.h>
#include <libsoup/soup-requester.h>
#include <libsoup/soup-request-http.h>
#include <camel/camel.h>
#include <webkit/webkit.h>

#include <e-util/e-util.h>
#include <mail/em-utils.h>
#include <libemail-engine/e-mail-enumtypes.h>

#include <string.h>

#include <em-format/e-mail-formatter.h>
#include <shell/e-shell.h>

#define d(x)

#define E_HTTP_REQUEST_GET_PRIVATE(obj) \
    (G_TYPE_INSTANCE_GET_PRIVATE \
    ((obj), E_TYPE_HTTP_REQUEST, EHTTPRequestPrivate))

struct _EHTTPRequestPrivate {
    gchar *content_type;
    gint content_length;

    EMailPartList *parts_list;
};

G_DEFINE_TYPE (EHTTPRequest, e_http_request, SOUP_TYPE_REQUEST)

static gssize
copy_stream_to_stream (CamelStream *input,
                       GMemoryInputStream *output,
                       GCancellable *cancellable)
{
    gchar *buff;
    gssize read_len = 0;
    gssize total_len = 0;

    g_seekable_seek (G_SEEKABLE (input), 0, G_SEEK_SET, cancellable, NULL);

    buff = g_malloc (4096);
    while ((read_len = camel_stream_read (input, buff, 4096, cancellable, NULL)) > 0) {

        g_memory_input_stream_add_data (output, buff, read_len, g_free);

        total_len += read_len;

        buff = g_malloc (4096);
    }

    /* Free the last unused buffer */
    g_free (buff);

    return total_len;
}

static gboolean
unref_soup_session (SoupSession *session)
{
    g_object_unref (session);

    return FALSE;
}

static void
handle_http_request (GSimpleAsyncResult *res,
                     GObject *object,
                     GCancellable *cancellable)
{
    EHTTPRequest *request = E_HTTP_REQUEST (object);
    SoupURI *soup_uri;
    gchar *evo_uri, *uri;
    gchar *mail_uri;
    GInputStream *stream;
    gboolean force_load_images = FALSE;
    EMailImageLoadingPolicy image_policy;
    gchar *uri_md5;
    EMailFormatter *formatter;
    EShell *shell;

    const gchar *user_cache_dir;
    CamelDataCache *cache;
    CamelStream *cache_stream;

    GHashTable *query;
    gint uri_len;

    if (g_cancellable_is_cancelled (cancellable)) {
        return;
    }

    formatter = e_mail_formatter_new ();

    /* Remove the __evo-mail query */
    soup_uri = soup_request_get_uri (SOUP_REQUEST (request));
    query = soup_form_decode (soup_uri->query);
    mail_uri = g_hash_table_lookup (query, "__evo-mail");
    if (mail_uri)
        mail_uri = g_strdup (mail_uri);

    g_hash_table_remove (query, "__evo-mail");

    /* Remove __evo-load-images if present (and in such case set
     * force_load_images to TRUE) */
    force_load_images = g_hash_table_remove (query, "__evo-load-images");

    soup_uri_set_query_from_form (soup_uri, query);
    g_hash_table_unref (query);

    evo_uri = soup_uri_to_string (soup_uri, FALSE);

    /* Remove the "evo-" prefix from scheme */
    uri_len = strlen (evo_uri);
    uri = NULL;
    if (evo_uri && (uri_len > 5)) {

        /* Remove trailing "?" if there is no URI query */
        if (evo_uri[uri_len - 1] == '?') {
            uri = g_strndup (evo_uri + 4, uri_len - 5);
        } else {
            uri = g_strdup (evo_uri + 4);
        }
        g_free (evo_uri);
    }

    g_return_if_fail (uri && *uri);

    /* Use MD5 hash of the URI as a filname of the resourec cache file.
     * We were previously using the URI as a filename but the URI is
     * sometimes too long for a filename. */
    uri_md5 = g_compute_checksum_for_string (G_CHECKSUM_MD5, uri, -1);

    /* Open Evolution's cache */
    user_cache_dir = e_get_user_cache_dir ();
    cache = camel_data_cache_new (user_cache_dir, NULL);
    if (cache) {
        camel_data_cache_set_expire_age (cache, 24 * 60 * 60);
        camel_data_cache_set_expire_access (cache, 2 * 60 * 60);
    }

    /* Found item in cache! */
    cache_stream = camel_data_cache_get (cache, "http", uri_md5, NULL);
    if (cache_stream) {

        gssize len;

        stream = g_memory_input_stream_new ();

        len = copy_stream_to_stream (
            cache_stream,
            G_MEMORY_INPUT_STREAM (stream), cancellable);
        request->priv->content_length = len;

        g_object_unref (cache_stream);

        /* When succesfully read some data from cache then
         * get mimetype and return the stream to WebKit.
         * Otherwise try to fetch the resource again from the network. */
        if ((len != -1) && (request->priv->content_length > 0)) {
            GFile *file;
            GFileInfo *info;
            gchar *path;

            path = camel_data_cache_get_filename (cache, "http", uri_md5);
            file = g_file_new_for_path (path);
            info = g_file_query_info (
                file, G_FILE_ATTRIBUTE_STANDARD_CONTENT_TYPE,
                0, cancellable, NULL);

            request->priv->content_type = g_strdup (
                g_file_info_get_content_type (info));

            d (
                printf ("'%s' found in cache (%d bytes, %s)\n",
                uri, request->priv->content_length,
                request->priv->content_type));

            g_object_unref (info);
            g_object_unref (file);
            g_free (path);

            /* Set result and quit the thread */
            g_simple_async_result_set_op_res_gpointer (res, stream, NULL);

            goto cleanup;
        } else {
            d (printf ("Failed to load '%s' from cache.\n", uri));
        }
    }

    /* If the item is not in the cache and Evolution is in offline mode then
     * quit regardless any image loading policy */
    shell = e_shell_get_default ();
    if (!e_shell_get_online (shell)) {
        goto cleanup;
    }

    /* Item not found in cache, but image loading policy allows us to fetch
     * it from the interwebs */
    image_policy = e_mail_formatter_get_image_loading_policy (formatter);
    if (!force_load_images && mail_uri &&
        (image_policy == E_MAIL_IMAGE_LOADING_POLICY_SOMETIMES)) {
        CamelObjectBag *registry;
        gchar *decoded_uri;
        EMailPartList *part_list;

        registry = e_mail_part_list_get_registry ();
        decoded_uri = soup_uri_decode (mail_uri);

        part_list = camel_object_bag_get (registry, decoded_uri);
        if (part_list) {
            EShell *shell;
            ESourceRegistry *registry;
            CamelInternetAddress *addr;

            shell = e_shell_get_default ();
            registry = e_shell_get_registry (shell);
            addr = camel_mime_message_get_from (part_list->message);
            force_load_images = em_utils_in_addressbook (
                    registry, addr, FALSE, cancellable);

            g_object_unref (part_list);
        }

        g_free (decoded_uri);
    }

    if ((image_policy == E_MAIL_IMAGE_LOADING_POLICY_ALWAYS) ||
        force_load_images) {

        SoupRequester *requester;
        SoupRequest *http_request;
        SoupSession *session;
        SoupMessage *msg;
        CamelStream *cache_stream;
        GError *error;
        gssize nread;
        SoupURI *soup_uri;
        gsize real_content_length;
        GInputStream *http_stream;

        session = soup_session_sync_new_with_options (
                SOUP_SESSION_TIMEOUT, 90,
                NULL);

        requester = soup_requester_new ();
        soup_session_add_feature (session, SOUP_SESSION_FEATURE (requester));
        g_object_unref (requester);

        error = NULL;
        soup_uri = soup_uri_new (uri);
        http_request = soup_requester_request_uri (requester, soup_uri, &error);
        soup_uri_free (soup_uri);
        if (error) {
            g_warning ("Failed to request %s: %s", uri, error->message);
            g_clear_error (&error);
            goto cleanup;
        }

        error = NULL;
        http_stream = soup_request_send (http_request, cancellable, &error);
        msg = soup_request_http_get_message (SOUP_REQUEST_HTTP (http_request));
        if (!msg || msg->status_code != SOUP_STATUS_OK) {
            g_warning (
                "Failed to retrieve data from %s: %s (code %d)",
                uri, error ? error->message : "Unknown error",
                msg->status_code);
            g_clear_error (&error);
            goto cleanup;
        }

        error = NULL;
        cache_stream = camel_data_cache_add (cache, "http", uri_md5, &error);
        if (!cache_stream) {
            g_warning (
                "Failed to create cache file for '%s': %s",
                uri, error ? error->message : "Unknown error");
            g_clear_error (&error);

            /* We rely on existence of the stream. If CamelDataCache
             * failed to create a cache file, then store it at least
             * temporarily. */
            cache_stream = camel_stream_mem_new ();
        }

        real_content_length = 0;
        do {
            gchar buf[512];

            error = NULL;
            nread = g_input_stream_read (
                    http_stream, buf, 512, cancellable, &error);
            if (nread == -1) {
                g_warning (
                    "Failed to read data from input stream: %s",
                    error ? error->message : "Unknown error");
                g_clear_error (&error);
                goto cleanup;
            }

            error = NULL;
            camel_stream_write (
                cache_stream, buf, nread, cancellable, &error);
            if (error) {
                g_warning (
                    "Failed to write data to cache stream: %s",
                    error->message);
                g_clear_error (&error);
                goto cleanup;
            }

            real_content_length += nread;

        } while (nread > 0);

        /* XXX For some reason, WebKit refuses to display content of
         * GInputStream we get from soup_request_send(), so create a
         * new input stream here and fill it with what's in the cache
         * stream. */
        stream = g_memory_input_stream_new ();
        copy_stream_to_stream (
            cache_stream, G_MEMORY_INPUT_STREAM (stream), cancellable);

        g_input_stream_close (http_stream, cancellable, NULL);
        g_object_unref (http_stream);

        /* Don't use the content-length header as it is sometimes missing
         * or invalid */
        request->priv->content_length = real_content_length;
        request->priv->content_type =
            g_strdup (
                soup_message_headers_get_content_type (
                    msg->response_headers, NULL));

        camel_stream_close (cache_stream, cancellable, NULL);
        g_object_unref (cache_stream);
        g_object_unref (http_request);
        g_object_unref (msg);
        g_idle_add ((GSourceFunc) unref_soup_session, session);

        d (printf ("Received image from %s\n"
            "Content-Type: %s\n"
            "Content-Length: %d bytes\n"
            "URI MD5: %s:\n",
            uri, request->priv->content_type,
            request->priv->content_length, uri_md5));

        g_simple_async_result_set_op_res_gpointer (res, stream, NULL);
        goto cleanup;
    }

 cleanup:
    if (cache) {
        g_object_unref (cache);
    }
    g_free (uri);
    g_free (uri_md5);
    g_free (mail_uri);
}

static void
http_request_finalize (GObject *object)
{
    EHTTPRequest *request = E_HTTP_REQUEST (object);

    if (request->priv->content_type) {
        g_free (request->priv->content_type);
        request->priv->content_type = NULL;
    }

    if (request->priv->parts_list) {
        g_object_unref (request->priv->parts_list);
        request->priv->parts_list = NULL;
    }

    G_OBJECT_CLASS (e_http_request_parent_class)->finalize (object);
}

static gboolean
http_request_check_uri (SoupRequest *request,
                        SoupURI *uri,
                        GError **error)
{
    return ((strcmp (uri->scheme, "evo-http") == 0) ||
        (strcmp (uri->scheme, "evo-https") == 0));
}

static void
http_request_send_async (SoupRequest *request,
                         GCancellable *cancellable,
                         GAsyncReadyCallback callback,
                         gpointer user_data)
{
    EHTTPRequest *ehr;
    GSimpleAsyncResult *simple;
    gchar *mail_uri;
    SoupURI *uri;
    const gchar *enc;
    CamelObjectBag *registry;
    GHashTable *query;

    ehr = E_HTTP_REQUEST (request);
    uri = soup_request_get_uri (request);
    query = soup_form_decode (uri->query);

    d ({
        gchar *uri_str = soup_uri_to_string (uri, FALSE);
        printf ("received request for %s\n", uri_str);
        g_free (uri_str);
    });

    enc = g_hash_table_lookup (query, "__evo-mail");

    if (!enc || !*enc) {
        g_hash_table_destroy (query);
        return;
    }

    mail_uri = soup_uri_decode (enc);

    registry = e_mail_part_list_get_registry ();
    ehr->priv->parts_list = camel_object_bag_get (registry, mail_uri);
    g_free (mail_uri);

    g_return_if_fail (ehr->priv->parts_list);

    simple = g_simple_async_result_new (
        G_OBJECT (request), callback,
        user_data, http_request_send_async);

    g_simple_async_result_set_check_cancellable (simple, cancellable);

    g_simple_async_result_run_in_thread (
        simple, handle_http_request,
        G_PRIORITY_DEFAULT, cancellable);

    g_object_unref (simple);

    g_hash_table_destroy (query);
}

static GInputStream *
http_request_send_finish (SoupRequest *request,
                          GAsyncResult *result,
                          GError **error)
{
    GInputStream *stream;

    stream = g_simple_async_result_get_op_res_gpointer (G_SIMPLE_ASYNC_RESULT (result));

    /* Reset the stream before passing it back to webkit */
    if (stream && G_IS_SEEKABLE (stream))
        g_seekable_seek (G_SEEKABLE (stream), 0, G_SEEK_SET, NULL, NULL);

    if (!stream) /* We must always return something */
        stream = g_memory_input_stream_new ();

    return stream;
}

static goffset
http_request_get_content_length (SoupRequest *request)
{
    EHTTPRequest *efr = E_HTTP_REQUEST (request);

    d (printf ("Content-Length: %d bytes\n", efr->priv->content_length));
    return efr->priv->content_length;
}

static const gchar *
http_request_get_content_type (SoupRequest *request)
{
    EHTTPRequest *efr = E_HTTP_REQUEST (request);

    d (printf ("Content-Type: %s\n", efr->priv->content_type));

    return efr->priv->content_type;
}

static const gchar *data_schemes[] = { "evo-http", "evo-https", NULL };

static void
e_http_request_class_init (EHTTPRequestClass *class)
{
    GObjectClass *object_class;
    SoupRequestClass *request_class;

    g_type_class_add_private (class, sizeof (EHTTPRequestPrivate));

    object_class = G_OBJECT_CLASS (class);
    object_class->finalize = http_request_finalize;

    request_class = SOUP_REQUEST_CLASS (class);
    request_class->schemes = data_schemes;
    request_class->send_async = http_request_send_async;
    request_class->send_finish = http_request_send_finish;
    request_class->get_content_type = http_request_get_content_type;
    request_class->get_content_length = http_request_get_content_length;
    request_class->check_uri = http_request_check_uri;
}

static void
e_http_request_init (EHTTPRequest *request)
{
    request->priv = E_HTTP_REQUEST_GET_PRIVATE (request);
}