inject_randr1.5: Intercept X11 error responses in addition to replies

Allow clients to send garbage to the server, then intercept the
server's error response and substitute it with the supplied simulated
reply data.
next
Vladimir Panteleev 2017-09-12 08:39:15 +00:00
parent f88f4fb5d4
commit de1b578f75
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1 changed files with 38 additions and 24 deletions

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@ -276,6 +276,32 @@ static void read_client_x11_packet_cb(EV_P_ ev_io *w, int revents) {
free(request);
}
static bool handle_sequence(struct connstate *connstate, uint16_t sequence) {
/* BEGIN RandR 1.5 specific */
if (sequence == connstate->getmonitors) {
printf("RRGetMonitors reply!\n");
if (getmonitors_reply.buf != NULL) {
printf("injecting reply\n");
((generic_x11_reply_t *)getmonitors_reply.buf)->sequence = sequence;
must_write(writeall(connstate->clientw->fd, getmonitors_reply.buf, getmonitors_reply.len));
return true;
}
}
if (sequence == connstate->getoutputinfo) {
printf("RRGetOutputInfo reply!\n");
if (getoutputinfo_reply.buf != NULL) {
printf("injecting reply\n");
((generic_x11_reply_t *)getoutputinfo_reply.buf)->sequence = sequence;
must_write(writeall(connstate->clientw->fd, getoutputinfo_reply.buf, getoutputinfo_reply.len));
return true;
}
}
/* END RandR 1.5 specific */
return false;
}
static void read_server_x11_packet_cb(EV_P_ ev_io *w, int revents) {
struct connstate *connstate = (struct connstate *)w->data;
// all packets from the server are at least 32 bytes in length
@ -283,9 +309,14 @@ static void read_server_x11_packet_cb(EV_P_ ev_io *w, int revents) {
void *packet = smalloc(len);
must_read(readall_into(packet, len, connstate->serverw->fd));
switch (((generic_x11_reply_t *)packet)->code) {
case 0: // error
case 0: { // error
const uint16_t sequence = ((xcb_request_error_t *)packet)->sequence;
if (handle_sequence(connstate, sequence)) {
free(packet);
return;
}
break;
}
case 1: // reply
len += ((generic_x11_reply_t *)packet)->length * 4;
if (len > 32) {
@ -300,30 +331,13 @@ static void read_server_x11_packet_cb(EV_P_ ev_io *w, int revents) {
xcb_query_extension_reply_t *reply = packet;
connstate->randr_major_opcode = reply->major_opcode;
}
if (sequence == connstate->getmonitors) {
printf("RRGetMonitors reply!\n");
if (getmonitors_reply.buf != NULL) {
printf("injecting reply\n");
((generic_x11_reply_t *)getmonitors_reply.buf)->sequence = sequence;
must_write(writeall(connstate->clientw->fd, getmonitors_reply.buf, getmonitors_reply.len));
free(packet);
return;
}
}
if (sequence == connstate->getoutputinfo) {
printf("RRGetOutputInfo reply!\n");
if (getoutputinfo_reply.buf != NULL) {
printf("injecting reply\n");
((generic_x11_reply_t *)getoutputinfo_reply.buf)->sequence = sequence;
must_write(writeall(connstate->clientw->fd, getoutputinfo_reply.buf, getoutputinfo_reply.len));
free(packet);
return;
}
}
/* END RandR 1.5 specific */
if (handle_sequence(connstate, sequence)) {
free(packet);
return;
}
break;
default: // event