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 <libedataserver/e-flag.h>

#include <string.h>

#include "em-format-html.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;

    EMFormatHTML *efh;
};

G_DEFINE_TYPE (EHTTPRequest, e_http_request, SOUP_TYPE_REQUEST)

struct http_request_async_data {
    EFlag *flag;

    GMainLoop *loop;
    GCancellable *cancellable;
    CamelDataCache *cache;
    gchar *cache_key;

    CamelStream *cache_stream;
    gchar *content_type;
    goffset content_length;

    gchar *buff;
};

static void
http_request_write_to_cache (GInputStream *stream,
                             GAsyncResult *res,
                             struct http_request_async_data *data)
{
    GError *error;
    gssize len;

    error = NULL;
    len = g_input_stream_read_finish (stream, res, &error);

    /* Error while reading data */
    if (len == -1) {
        if (!g_error_matches (error, G_IO_ERROR, G_IO_ERROR_CANCELLED)) {
            g_message ("Error while reading input stream: %s",
                error ? error->message : "Unknown error");
            g_clear_error (&error);
        }

        /* Don't keep broken data in cache */
        camel_data_cache_remove (data->cache, "http", data->cache_key, NULL);

        goto cleanup;
    }

    /* EOF */
    if (len == 0) {
        goto cleanup;
    }

    /* Write chunk to cache and read another block of data. */
    camel_stream_write (data->cache_stream, data->buff, len,
        data->cancellable, NULL);

    g_input_stream_read_async (stream, data->buff, 4096,
        G_PRIORITY_DEFAULT, data->cancellable,
        (GAsyncReadyCallback) http_request_write_to_cache, data);

    return;

 cleanup:
    if (data->buff)
        g_free (data->buff);

    g_object_unref (stream);

    g_main_loop_quit (data->loop);
    e_flag_set (data->flag);
}

static void
http_request_finished (SoupRequest *request,
                       GAsyncResult *res,
                       struct http_request_async_data *data)
{
    GError *error;
    SoupMessage *message;
    GInputStream *stream;

    error = NULL;
    stream = soup_request_send_finish (request, res, &error);
    /* If there is an error or the operation was canceled, do nothing */
    if (error) {
        g_main_loop_quit (data->loop);
        e_flag_set (data->flag);
        g_error_free (error);
        return;
    }

    if (!stream) {
        g_warning("HTTP request failed: %s", error ? error->message: "Unknown error");
        g_clear_error (&error);
        g_main_loop_quit (data->loop);
        e_flag_set (data->flag);
        return;
    }

    message = soup_request_http_get_message (SOUP_REQUEST_HTTP (request));
    if (!SOUP_STATUS_IS_SUCCESSFUL (message->status_code)) {
        g_warning ("HTTP request failed: HTTP code %d", message->status_code);
        g_object_unref (message);
        g_main_loop_quit (data->loop);
        e_flag_set (data->flag);
        return;
    }

    g_object_unref (message);

    data->content_length = soup_request_get_content_length (request);
    data->content_type = g_strdup (soup_request_get_content_type (request));

    if (!data->cache_stream || g_cancellable_is_cancelled (data->cancellable)) {
        g_main_loop_quit (data->loop);
        e_flag_set (data->flag);
        return;
    }

    data->buff = g_malloc (4096);
    g_input_stream_read_async (stream, data->buff, 4096,
        G_PRIORITY_DEFAULT, data->cancellable,
        (GAsyncReadyCallback) http_request_write_to_cache, data);
}

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 void
quit_main_loop (GCancellable *cancellable,
                GMainLoop *loop)
{
    if (g_main_loop_is_running (loop)) {
        g_main_loop_quit (loop);
    }
}

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

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

    GHashTable *query;

    if (g_cancellable_is_cancelled (cancellable)) {
        return;
    }

    /* Remove the __evo-mail query */
    soup_uri = soup_request_get_uri (SOUP_REQUEST (request));
    query = soup_form_decode (soup_uri->query);
    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 */
    if (evo_uri && (strlen (evo_uri) > 5)) {
        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, NULL);
            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));
        }
    }

    /* Item not found in cache, but image loading policy allows us to fetch
     * it from the interwebs */
    if (force_load_images || em_format_html_can_load_images (request->priv->efh)) {

        SoupRequester *requester;
        SoupRequest *http_request;
        SoupSession *session;
        GMainContext *context;
        GError *error;
        gulong id;

        struct http_request_async_data data = { 0 };

        context = g_main_context_get_thread_default ();
        session = soup_session_async_new_with_options (
                    SOUP_SESSION_ASYNC_CONTEXT, context, NULL);

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

        http_request = soup_requester_request (requester, uri, NULL);

        error = NULL;
        data.flag = e_flag_new ();
        data.loop = g_main_loop_new (context, TRUE);
        data.cancellable = cancellable;
        data.cache = cache;
        data.cache_key = uri_md5;
        data.cache_stream = camel_data_cache_add (cache, "http", uri_md5, &error);

        if (!data.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. */
            data.cache_stream = camel_stream_mem_new ();
        }

        /* Send the request and waint in mainloop until it's finished
         * and copied to cache */
        d(printf(" '%s' not in cache, sending HTTP request\n", uri));
        soup_request_send_async (http_request, cancellable,
            (GAsyncReadyCallback) http_request_finished, &data);

        id = g_cancellable_connect (cancellable,
            G_CALLBACK (quit_main_loop), data.loop, NULL);

        /* Wait for the asynchronous HTTP GET to finish */
        g_main_loop_run (data.loop);
        d(printf (" '%s' fetched from internet and (hopefully) stored in"
              " cache\n", uri));

        g_cancellable_disconnect (cancellable, id);

        /* Wait until all asynchronous operations are finished working
         * with the 'data' structure so that it's not free'd too early. */
        e_flag_wait (data.flag);
        e_flag_free (data.flag);

        g_main_loop_unref (data.loop);

        g_object_unref (session);
        g_object_unref (http_request);
        g_object_unref (requester);

        /* Copy the content of cache stream to GInputStream that can be
         * returned to WebKit */
        stream = g_memory_input_stream_new ();
        copy_stream_to_stream (data.cache_stream,
            G_MEMORY_INPUT_STREAM (stream), cancellable);

        camel_stream_close (data.cache_stream, cancellable, NULL);
        g_object_unref (data.cache_stream);

        request->priv->content_length = data.content_length;
        request->priv->content_type = data.content_type;

        g_simple_async_result_set_op_res_gpointer (res, stream, NULL);

        goto cleanup;

    }

 cleanup:
    g_free (uri);
    g_free (uri_md5);
}

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->efh) {
        g_object_unref (request->priv->efh);
        request->priv->efh = 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;
    SoupSession *session;
    GHashTable *formatters, *query;

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

    d(printf("received request for %s\n", soup_uri_to_string (uri, FALSE)));

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

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

    mail_uri = soup_uri_decode (enc);

    session = webkit_get_default_session ();
    formatters = g_object_get_data (G_OBJECT (session), "formatters");
    g_return_if_fail (formatters != NULL);

    ehr->priv->efh = g_hash_table_lookup (formatters, mail_uri);
    g_free (mail_uri);

    g_return_if_fail (ehr->priv->efh);

    /* Make sure the formatter lives until we are finished here */
    g_object_ref (ehr->priv->efh);

    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);
}