[hackers] [surf/surf-webkit2] webext: Process full messages || Quentin Rameau

From: <git_AT_suckless.org>
Date: Sun, 2 Jun 2024 13:25:49 +0200 (CEST)

commit 9ef79bf7106496c736ba613c51d2fd5af9d873a8
Author: Quentin Rameau <quinq_AT_fifth.space>
AuthorDate: Sun Mar 24 15:24:22 2024 +0100
Commit: Quentin Rameau <quinq_AT_fifth.space>
CommitDate: Sun Mar 24 15:27:20 2024 +0100

    webext: Process full messages
    
    Piped messages would not always be fully sent in a single read.
    Do a bit of message reassembly.

diff --git a/webext-surf.c b/webext-surf.c
index 230c71b..7063fa7 100644
--- a/webext-surf.c
+++ b/webext-surf.c
_AT_@ -19,61 +19,99 @@
 static WebKitWebExtension *webext;
 static int sock;
 
-static gboolean
-readsock(GIOChannel *s, GIOCondition c, gpointer unused)
+/*
+ * Return:
+ * 0 No data processed: need more data
+ * > 0 Amount of data processed or discarded
+ */
+static size_t
+evalmsg(char *msg, size_t sz)
 {
- static char js[48], msg[MSGBUFSZ];
+ char js[48];
         WebKitWebPage *page;
         JSCContext *jsc;
         JSCValue *jsv;
- GError *gerr = NULL;
- gsize msgsz;
-
- if (g_io_channel_read_chars(s, msg, sizeof(msg), &msgsz, &gerr) !=
- G_IO_STATUS_NORMAL) {
- if (gerr) {
- fprintf(stderr, "webext: error reading socket: %s\n",
- gerr->message);
- g_error_free(gerr);
- }
- return TRUE;
- }
-
- if (msgsz < 2) {
- fprintf(stderr, "webext: readsock: message too short: %lu\n",
- msgsz);
- return TRUE;
- }
 
         if (!(page = webkit_web_extension_get_page(webext, msg[0])))
- return TRUE;
+ return sz;
+
+ if (sz < 2)
+ return 0;
 
         jsc = webkit_frame_get_js_context(webkit_web_page_get_main_frame(page));
         jsv = NULL;
 
         switch (msg[1]) {
         case 'h':
- if (msgsz != 3)
- return TRUE;
+ if (sz < 3) {
+ sz = 0;
+ break;
+ }
+ sz = 3;
                 snprintf(js, sizeof(js),
                          "window.scrollBy(window.innerWidth/100*%hhd,0);",
                          msg[2]);
                 jsv = jsc_context_evaluate(jsc, js, -1);
                 break;
         case 'v':
- if (msgsz != 3)
- return TRUE;
+ if (sz < 3) {
+ sz = 0;
+ break;
+ }
+ sz = 3;
                 snprintf(js, sizeof(js),
                          "window.scrollBy(0,window.innerHeight/100*%hhd);",
                          msg[2]);
                 jsv = jsc_context_evaluate(jsc, js, -1);
                 break;
+ default:
+ fprintf(stderr, "%s:%d:evalmsg: unknown cmd(%zu): '%#x'\n",
+ __FILE__, __LINE__, sz, msg[1]);
         }
 
         g_object_unref(jsc);
         if (jsv)
                 g_object_unref(jsv);
 
+ return sz;
+}
+
+static gboolean
+readsock(GIOChannel *s, GIOCondition c, gpointer unused)
+{
+ static char msg[MSGBUFSZ];
+ static size_t msgoff;
+ GError *gerr = NULL;
+ size_t sz;
+ gsize rsz;
+
+ if (g_io_channel_read_chars(s, msg+msgoff, sizeof(msg)-msgoff, &rsz, &gerr) !=
+ G_IO_STATUS_NORMAL) {
+ if (gerr) {
+ fprintf(stderr, "webext: error reading socket: %s\n",
+ gerr->message);
+ g_error_free(gerr);
+ }
+ return TRUE;
+ }
+ if (msgoff >= sizeof(msg)) {
+ fprintf(stderr, "%s:%d:%s: msgoff: %zu", __FILE__, __LINE__, __func__, msgoff);
+ return FALSE;
+ }
+
+ for (rsz += msgoff; rsz; rsz -= sz) {
+ sz = evalmsg(msg, rsz);
+ if (sz == 0) {
+ /* need more data */
+ break;
+ }
+ if (sz != rsz) {
+ /* continue processing message */
+ memmove(msg, msg+sz, rsz-sz);
+ }
+ }
+ msgoff = rsz;
+
         return TRUE;
 }
 
Received on Sun Jun 02 2024 - 13:25:49 CEST