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.
 *
 * 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 Lesser General Public License
 * along with this program; if not, see <http://www.gnu.org/licenses/>.
 *
 */

#include "e-http-request.h"

#include <config.h>
#include <string.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 <libemail-engine/libemail-engine.h>

#include <mail/em-utils.h>

#include <shell/e-shell.h>

#include "e-mail-ui-session.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;
};

G_DEFINE_TYPE (EHTTPRequest, e_http_request, SOUP_TYPE_REQUEST)

static gssize
copy_stream_to_stream (GIOStream *file_io_stream,
                       GMemoryInputStream *output,
                       GCancellable *cancellable)
{
    GInputStream *input_stream;
    gchar *buff;
    gssize read_len = 0;
    gssize total_len = 0;
    const gsize buff_size = 4096;

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

    input_stream = g_io_stream_get_input_stream (file_io_stream);

    buff = g_malloc (buff_size);
    read_len = g_input_stream_read (
        input_stream, buff, buff_size, cancellable, NULL);
    while (read_len > 0) {
        g_memory_input_stream_add_data (
            output, buff, read_len, g_free);

        total_len += read_len;

        buff = g_malloc (buff_size);
        read_len = g_input_stream_read (
            input_stream, buff, buff_size, cancellable, NULL);
    }

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

    return total_len;
}

static void
redirect_handler (SoupMessage *msg,
                  gpointer user_data)
{
    if (SOUP_STATUS_IS_REDIRECTION (msg->status_code)) {
        SoupSession *soup_session = user_data;
        SoupURI *new_uri;
        const gchar *new_loc;

        new_loc = soup_message_headers_get_list (
            msg->response_headers, "Location");
        if (new_loc == NULL)
            return;

        new_uri = soup_uri_new_with_base (
            soup_message_get_uri (msg), new_loc);
        if (new_uri == NULL) {
            soup_message_set_status_full (
                msg,
                SOUP_STATUS_MALFORMED,
                "Invalid Redirect URL");
            return;
        }

        soup_message_set_uri (msg, new_uri);
        soup_session_requeue_message (soup_session, msg);

        soup_uri_free (new_uri);
    }
}

static void
send_and_handle_redirection (SoupSession *session,
                             SoupMessage *message,
                             gchar **new_location)
{
    SoupURI *soup_uri;
    gchar *old_uri = NULL;

    g_return_if_fail (message != NULL);

    soup_uri = soup_message_get_uri (message);

    if (new_location != NULL)
        old_uri = soup_uri_to_string (soup_uri, FALSE);

    soup_message_set_flags (message, SOUP_MESSAGE_NO_REDIRECT);
    soup_message_add_header_handler (
        message, "got_body", "Location",
        G_CALLBACK (redirect_handler), session);
    soup_message_headers_append (
        message->request_headers, "Connection", "close");
    soup_session_send_message (session, message);

    if (new_location != NULL) {
        gchar *new_loc;

        new_loc = soup_uri_to_string (soup_uri, FALSE);

        if (new_loc && old_uri && !g_str_equal (new_loc, old_uri)) {
            *new_location = new_loc;
        } else {
            g_free (new_loc);
        }
    }

    g_free (old_uri);
}

static void
handle_http_request (GSimpleAsyncResult *res,
                     GObject *source_object,
                     GCancellable *cancellable)
{
    EHTTPRequestPrivate *priv;
    SoupURI *soup_uri;
    SoupRequest *soup_request;
    SoupSession *soup_session;
    gchar *evo_uri, *uri;
    gchar *mail_uri;
    GInputStream *stream;
    gboolean force_load_images = FALSE;
    EMailImageLoadingPolicy image_policy;
    gchar *uri_md5;
    EShell *shell;
    GSettings *settings;
    const gchar *user_cache_dir;
    CamelDataCache *cache;
    GIOStream *cache_stream;
    GHashTable *query;
    gint uri_len;

    if (g_cancellable_is_cancelled (cancellable))
        return;

    priv = E_HTTP_REQUEST_GET_PRIVATE (source_object);

    soup_request = SOUP_REQUEST (source_object);
    soup_session = soup_request_get_session (soup_request);

    /* Remove the __evo-mail query */
    soup_uri = soup_request_get_uri (soup_request);
    g_return_if_fail (soup_uri_get_query (soup_uri) != NULL);

    query = soup_form_decode (soup_uri_get_query (soup_uri));
    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);

    if (camel_debug_start ("emformat:requests")) {
        printf (
            "%s: looking for '%s'\n",
            G_STRFUNC, evo_uri ? evo_uri : "[null]");
        camel_debug_end ();
    }

    /* Remove the "evo-" prefix from scheme */
    uri_len = (evo_uri != NULL) ? strlen (evo_uri) : 0;
    uri = NULL;
    if (evo_uri != NULL && (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);
    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 != NULL) {
        gssize len;

        stream = g_memory_input_stream_new ();

        len = copy_stream_to_stream (
            cache_stream,
            G_MEMORY_INPUT_STREAM (stream), cancellable);
        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) && (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);

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

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

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

    /* If the item is not cached and Evolution is offline
     * then quit regardless of any image loading policy. */
    shell = e_shell_get_default ();
    if (!e_shell_get_online (shell))
        goto cleanup;

    settings = g_settings_new ("org.gnome.evolution.mail");
    image_policy = g_settings_get_enum (settings, "image-loading-policy");
    g_object_unref (settings);

    /* Item not found in cache, but image loading policy allows us to fetch
     * it from the interwebs */
    if (!force_load_images && mail_uri != NULL &&
        (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 != NULL) {
            EShellBackend *shell_backend;
            EMailBackend *backend;
            EMailSession *session;
            CamelInternetAddress *addr;
            CamelMimeMessage *message;
            gboolean known_address = FALSE;
            GError *error = NULL;

            shell_backend =
                e_shell_get_backend_by_name (shell, "mail");
            backend = E_MAIL_BACKEND (shell_backend);
            session = e_mail_backend_get_session (backend);

            message = e_mail_part_list_get_message (part_list);
            addr = camel_mime_message_get_from (message);

            e_mail_ui_session_check_known_address_sync (
                E_MAIL_UI_SESSION (session),
                addr, FALSE, cancellable,
                &known_address, &error);

            if (error != NULL) {
                g_warning ("%s: %s", G_STRFUNC, error->message);
                g_error_free (error);
            }

            if (known_address)
                force_load_images = TRUE;

            g_object_unref (part_list);
        }

        g_free (decoded_uri);
    }

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

        SoupSession *temp_session;
        SoupMessage *message;
        GIOStream *cache_stream;
        GError *error;
        GMainContext *context;

        context = g_main_context_new ();
        g_main_context_push_thread_default (context);

        temp_session = soup_session_new_with_options (
            SOUP_SESSION_TIMEOUT, 90, NULL);

        g_object_bind_property (
            soup_session, "proxy-resolver",
            temp_session, "proxy-resolver",
            G_BINDING_SYNC_CREATE);

        message = soup_message_new (SOUP_METHOD_GET, uri);
        soup_message_headers_append (
            message->request_headers,
            "User-Agent", "Evolution/" VERSION);

        send_and_handle_redirection (temp_session, message, NULL);

        if (!SOUP_STATUS_IS_SUCCESSFUL (message->status_code)) {
            g_debug ("Failed to request %s (code %d)", uri, message->status_code);
            g_object_unref (message);
            g_object_unref (temp_session);
            g_main_context_unref (context);
            goto cleanup;
        }

        /* Write the response body to cache */
        error = NULL;
        cache_stream = camel_data_cache_add (
            cache, "http", uri_md5, &error);
        if (error != NULL) {
            g_warning (
                "Failed to create cache file for '%s': %s",
                uri, error->message);
            g_clear_error (&error);
        } else {
            GOutputStream *output_stream;

            output_stream =
                g_io_stream_get_output_stream (cache_stream);

            g_output_stream_write_all (
                output_stream,
                message->response_body->data,
                message->response_body->length,
                NULL, cancellable, &error);

            g_io_stream_close (cache_stream, NULL, NULL);
            g_object_unref (cache_stream);

            if (error != NULL) {
                if (!g_error_matches (error, G_IO_ERROR, G_IO_ERROR_CANCELLED))
                    g_warning (
                        "Failed to write data to cache stream: %s",
                        error->message);
                g_clear_error (&error);
                g_object_unref (message);
                g_object_unref (temp_session);
                g_main_context_unref (context);
                goto cleanup;
            }
        }

        /* Send the response body to WebKit */
        stream = g_memory_input_stream_new_from_data (
            g_memdup (
                message->response_body->data,
                message->response_body->length),
            message->response_body->length,
            (GDestroyNotify) g_free);

        priv->content_length = message->response_body->length;
        priv->content_type = g_strdup (
            soup_message_headers_get_content_type (
                message->response_headers, NULL));

        g_object_unref (message);
        g_object_unref (temp_session);
        g_main_context_unref (context);

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

        g_simple_async_result_set_op_res_gpointer (res, stream, g_object_unref);

        goto cleanup;
    }

cleanup:
    g_clear_object (&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;
    }

    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)
{
    GSimpleAsyncResult *simple;
    SoupURI *uri;
    const gchar *enc;
    GHashTable *query;

    uri = soup_request_get_uri (request);
    g_return_if_fail (soup_uri_get_query (uri) != NULL);

    query = soup_form_decode (soup_uri_get_query (uri));

    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 == NULL || *enc == '\0') {
        g_hash_table_destroy (query);
        return;
    }

    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 ();
    else
        g_object_ref (stream);

    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);
}