/soc/2015/jgeboski/facebook: 2d85594bb9ee: facebook: fixed JSON ...

[James Geboski]

Changeset: 2d85594bb9ee9913178ef6b6e70f092398b54a49
Author:	 James Geboski <jgeboski at gmail.com>
Date:	 2015-06-22 16:46 -0400
Branch:	 facebook
URL: https://hg.pidgin.im/soc/2015/jgeboski/facebook/rev/2d85594bb9ee

Description:

facebook: fixed JSON parse errors with messages

It was assumed there was always a leading "NULL" byte prepended to each
message. This is not the case, the NULL byte is actually a variable
integer, which is the size for a Thrift string. In order to navigate
directly the JSON data, just read the data as a thrift string in order
to obtain the offset of the JSON data.

diffstat:

 libpurple/protocols/facebook/api.c    |  12 ++++++++++--
 libpurple/protocols/facebook/thrift.c |  20 ++++++++++++++++++++
 libpurple/protocols/facebook/thrift.h |   6 ++++++
 3 files changed, 36 insertions(+), 2 deletions(-)

diffs (80 lines):

diff --git a/libpurple/protocols/facebook/api.c b/libpurple/protocols/facebook/api.c
--- a/libpurple/protocols/facebook/api.c
+++ b/libpurple/protocols/facebook/api.c
@@ -647,6 +647,7 @@ fb_api_cb_publish_ms(FbApi *api, const G
 	const gchar *str;
 	FbApiMessage msg;
 	FbApiPrivate *priv = api->priv;
+	FbThrift *thft;
 	GError *err = NULL;
 	gint64 tid;
 	gint64 uid;
@@ -654,13 +655,20 @@ fb_api_cb_publish_ms(FbApi *api, const G
 	GList *l;
 	gpointer mptr;
 	GSList *msgs = NULL;
+	guint i;
 	JsonArray *arr;
 	JsonNode *mode;
 	JsonNode *node;
 	JsonNode *root;
 
-	/* Start at 1 to skip the NULL byte */
-	if (!fb_api_json_chk(api, pload->data + 1, pload->len - 1, &root)) {
+	thft = fb_thrift_new((GByteArray*) pload, 0, TRUE);
+	fb_thrift_read_str(thft, NULL);
+	i = fb_thrift_get_pos(thft);
+	g_object_unref(thft);
+
+	g_return_if_fail(i < pload->len);
+
+	if (!fb_api_json_chk(api, pload->data + i, pload->len - i, &root)) {
 		return;
 	}
 
diff --git a/libpurple/protocols/facebook/thrift.c b/libpurple/protocols/facebook/thrift.c
--- a/libpurple/protocols/facebook/thrift.c
+++ b/libpurple/protocols/facebook/thrift.c
@@ -88,6 +88,26 @@ fb_thrift_new(GByteArray *bytes, guint o
 	return thft;
 }
 
+guint
+fb_thrift_get_pos(FbThrift *thft)
+{
+	FbThriftPrivate *priv;
+
+	g_return_val_if_fail(FB_IS_THRIFT(thft), 0);
+	priv = thft->priv;
+	return priv->pos;
+}
+
+void
+fb_thrift_set_pos(FbThrift *thft, guint pos)
+{
+	FbThriftPrivate *priv;
+
+	g_return_if_fail(FB_IS_THRIFT(thft));
+	priv = thft->priv;
+	priv->pos = pos;
+}
+
 void
 fb_thrift_reset(FbThrift *thft)
 {
diff --git a/libpurple/protocols/facebook/thrift.h b/libpurple/protocols/facebook/thrift.h
--- a/libpurple/protocols/facebook/thrift.h
+++ b/libpurple/protocols/facebook/thrift.h
@@ -84,6 +84,12 @@ fb_thrift_get_type(void);
 FbThrift *
 fb_thrift_new(GByteArray *bytes, guint offset, gboolean compact);
 
+guint
+fb_thrift_get_pos(FbThrift *thft);
+
+void
+fb_thrift_set_pos(FbThrift *thft, guint pos);
+
 void
 fb_thrift_reset(FbThrift *thft);