channels: Fix checking for fatal errors.

We need this that we don't end up in and infinite poll loop.

src/channels.c

@@ -1452,6 +1452,11 @@ static int channel_request(ssh_channel channel, const char *request,
   }
   while(channel->request_state == SSH_CHANNEL_REQ_STATE_PENDING){
     ssh_handle_packets(session,-1);
+    if(session->session_state == SSH_SESSION_STATE_ERROR) {
+	channel->request_state = SSH_CHANNEL_REQ_STATE_ERROR;
+	break;
+    }
+
   }
   /* we received something */
   switch (channel->request_state){

src/poll.c

@@ -612,11 +612,16 @@ int ssh_poll_ctx_dopoll(ssh_poll_ctx ctx, int timeout) {
     if (!ctx->pollfds[i].revents) {
       i++;
     } else {
+      int ret;
+
       p = ctx->pollptrs[i];
       fd = ctx->pollfds[i].fd;
       revents = ctx->pollfds[i].revents;
 
-      if (p->cb && p->cb(p, fd, revents, p->cb_data) < 0) {
+      if (p->cb && (ret = p->cb(p, fd, revents, p->cb_data)) < 0) {
+        if (ret == -2) {
+            return -1;
+        }
         /* the poll was removed, reload the used counter and start again */
         used = ctx->polls_used;
         i=0;

src/socket.c

@@ -246,32 +246,34 @@ int ssh_socket_pollcallback(struct ssh_poll_handle_struct *p, socket_t fd, int r
 		s->read_wontblock=1;
 		r=ssh_socket_unbuffered_read(s,buffer,sizeof(buffer));
 		if(r<0){
-            if(p != NULL) {
-                ssh_poll_remove_events(p, POLLIN);
-            }
+		if(p != NULL) {
+			ssh_poll_remove_events(p, POLLIN);
+		}
 			if(s->callbacks && s->callbacks->exception){
 				s->callbacks->exception(
 						SSH_SOCKET_EXCEPTION_ERROR,
 						s->last_errno,s->callbacks->userdata);
-                /* p may have been freed, so don't use it
-                 * anymore in this function */
-                p = NULL;
+				/* p may have been freed, so don't use it
+				* anymore in this function */
+				p = NULL;
+				return -2;
 			}
 		}
 		if(r==0){
-            if(p != NULL) {
-                ssh_poll_remove_events(p, POLLIN);
-            }
-            if(p != NULL) {
-                ssh_poll_remove_events(p, POLLIN);
-            }
+			if(p != NULL) {
+				ssh_poll_remove_events(p, POLLIN);
+			}
+			if(p != NULL) {
+				ssh_poll_remove_events(p, POLLIN);
+			}
 			if(s->callbacks && s->callbacks->exception){
 				s->callbacks->exception(
 						SSH_SOCKET_EXCEPTION_EOF,
 						0,s->callbacks->userdata);
-                /* p may have been freed, so don't use it
-                 * anymore in this function */
-                p = NULL;
+				/* p may have been freed, so don't use it
+				* anymore in this function */
+				p = NULL;
+				return -2;
 			}
 		}
 		if(r>0){
@@ -282,9 +284,9 @@ int ssh_socket_pollcallback(struct ssh_poll_handle_struct *p, socket_t fd, int r
 						buffer_get_rest_len(s->in_buffer),
 						s->callbacks->userdata);
 				buffer_pass_bytes(s->in_buffer,r);
-                /* p may have been freed, so don't use it
-                 * anymore in this function */
-                p = NULL;
+				/* p may have been freed, so don't use it
+				* anymore in this function */
+				p = NULL;
 			}
 		}
 	}