warn in debug mode if there may be a proxy loop

diff --git a/src/modules/rlm_radius/rlm_radius_udp.c b/src/modules/rlm_radius/rlm_radius_udp.c
index 98a55514def371decbbb14526e28781a69215621..9205f1e8e6be1cf2447805648fd813f471eb50f9 100644 (file)
--- a/src/modules/rlm_radius/rlm_radius_udp.c
+++ b/src/modules/rlm_radius/rlm_radius_udp.c
@@ -2024,9 +2024,33 @@ static int conn_write(fr_io_connection_t *c, fr_io_request_t *u)
        if (proxy_state) {
                uint8_t         *attr = c->buffer + packet_len;
                VALUE_PAIR      *vp;
+               vp_cursor_t     cursor;
+               int             count;
 
                rad_assert((size_t) (packet_len + proxy_state) <= c->buflen);
 
+               /*
+                *      Count how many Proxy-State attributes have
+                *      *our* magic number.
+                */
+               if (fr_debug_lvl) {
+                       count = 0;
+                       (void) fr_pair_cursor_init(&cursor, &request->packet->vps);
+                       while ((vp = fr_pair_cursor_next_by_da(&cursor, attr_proxy_state, TAG_ANY)) != NULL) {
+                               if ((vp->vp_length == 4) && (memcmp(vp->vp_octets, &c->inst->parent->proxy_state, 4) == 0)) {
+                                       count++;
+                               }
+                       }
+
+                       /*
+                        *      Some configurations may proxy to
+                        *      ourselves for tests / simplicity.  But
+                        *      warn if there are a large number of
+                        *      identical Proxy-State attributes.
+                        */
+                       if (count > 4) RWARN("Potential proxy loop detected!  Please recheck your configuration.");
+               }
+
                attr[0] = (uint8_t)attr_proxy_state->attr;
                attr[1] = 6;
                memcpy(attr + 2, &c->inst->parent->proxy_state, 4);