better memory handling of the request/cache chain

diff --git a/usr.sbin/rebound/rebound.c b/usr.sbin/rebound/rebound.c
index 28ea943..a6ee07e 100644 (file)
--- a/usr.sbin/rebound/rebound.c
+++ b/usr.sbin/rebound/rebound.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: rebound.c,v 1.11 2015/10/15 21:59:54 tedu Exp $ */
+/* $OpenBSD: rebound.c,v 1.12 2015/10/15 22:12:26 tedu Exp $ */
 /*
  * Copyright (c) 2015 Ted Unangst <tedu@openbsd.org>
  *
@@ -59,6 +59,12 @@ struct dnsrr {
        /* ... */
 };
 
+/*
+ * requests will point to cache entries until a response is received.
+ * until then, the request owns the entry and must free it.
+ * after it's on the list, the request must not free it.
+ */
+
 struct dnscache {
        TAILQ_ENTRY(dnscache) cache;
        struct dnspacket *req;
@@ -194,6 +200,7 @@ newrequest(int ud, struct sockaddr *remoteaddr)
 
        return req;
 fail:
+       free(hit);
        close(req->s);
        free(req);
        return NULL;
@@ -204,6 +211,7 @@ sendreply(int ud, struct request *req)
 {
        uint8_t buf[65536];
        struct dnspacket *resp;
+       struct dnscache *ent;
        size_t r;
 
        resp = (struct dnspacket *)buf;
@@ -215,24 +223,30 @@ sendreply(int ud, struct request *req)
                return;
        resp->id = req->clientid;
        sendto(ud, buf, r, 0, &req->from, req->fromlen);
-       if (req->cacheent) {
-               req->cacheent->ts = now;
-               req->cacheent->ts.tv_sec += 10;
-               req->cacheent->resp = malloc(r);
-               if (!req->cacheent->resp)
+       if ((ent = req->cacheent)) {
+               ent->ts = now;
+               ent->ts.tv_sec += 10;
+               ent->resp = malloc(r);
+               if (!ent->resp)
                        return;
-               memcpy(req->cacheent->resp, buf, r);
-               req->cacheent->resplen = r;
-               TAILQ_INSERT_TAIL(&cache, req->cacheent, cache);
+               memcpy(ent->resp, buf, r);
+               ent->resplen = r;
+               TAILQ_INSERT_TAIL(&cache, ent, cache);
        }
 }
 
 void
 freerequest(struct request *req)
 {
+       struct dnscache *ent;
+
        TAILQ_REMOVE(&reqfifo, req, fifo);
        close(req->client);
        close(req->s);
+       if ((ent = req->cacheent) && !ent->resp) {
+               free(ent->req);
+               free(ent);
+       }
        free(req);
 }