From: Willy Tarreau <w@1wt.eu>
Date: Sun, 12 Jul 2009 06:27:39 +0000 (+0200)
Subject: [MINOR] prepare callers of session_set_backend to handle errors
X-Git-Tag: v1.4-dev1~29
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=bedb9bad6768babdbe7fea5f79c19a710321cc9b;p=thirdparty%2Fhaproxy.git

[MINOR] prepare callers of session_set_backend to handle errors

session_set_backend will soon have to allocate areas for HTTP
headers. We must ensure that the callers can handle an allocation
error.
---

diff --git a/include/proto/proxy.h b/include/proto/proxy.h
index 36360e5cf5..0ad1e7fe8b 100644
--- a/include/proto/proxy.h
+++ b/include/proto/proxy.h
@@ -35,7 +35,7 @@ void pause_proxy(struct proxy *p);
 void stop_proxy(struct proxy *p);
 void pause_proxies(void);
 void listen_proxies(void);
-void session_set_backend(struct session *s, struct proxy *be);
+int  session_set_backend(struct session *s, struct proxy *be);
 
 const char *proxy_cap_str(int cap);
 const char *proxy_mode_str(int mode);
diff --git a/src/proxy.c b/src/proxy.c
index dcfb12d879..2dfc93b3b1 100644
--- a/src/proxy.c
+++ b/src/proxy.c
@@ -635,11 +635,12 @@ void listen_proxies(void)
  * session already had a backend assigned, which is indicated by
  * s->flags & SN_BE_ASSIGNED.
  * All flags, stats and counters which need be updated are updated.
+ * Returns 1 if done, 0 in case of internal error, eg: lack of resource.
  */
-void session_set_backend(struct session *s, struct proxy *be)
+int session_set_backend(struct session *s, struct proxy *be)
 {
 	if (s->flags & SN_BE_ASSIGNED)
-		return;
+		return 1;
 	s->be = be;
 	be->beconn++;
 	if (be->beconn > be->beconn_max)
@@ -653,6 +654,7 @@ void session_set_backend(struct session *s, struct proxy *be)
 	if (be->options2 & PR_O2_RSPBUG_OK)
 		s->txn.rsp.err_pos = -1; /* let buggy responses pass */
 	s->flags |= SN_BE_ASSIGNED;
+	return 1;
 }
 
 static struct cfg_kw_list cfg_kws = {{ },{
diff --git a/src/session.c b/src/session.c
index d4817ac2c3..7d95669fb4 100644
--- a/src/session.c
+++ b/src/session.c
@@ -586,7 +586,8 @@ int process_switching_rules(struct session *s, struct buffer *req, int an_bit)
 				ret = !ret;
 
 			if (ret) {
-				session_set_backend(s, rule->be.backend);
+				if (!session_set_backend(s, rule->be.backend))
+					goto sw_failed;
 				break;
 			}
 		}
@@ -597,7 +598,8 @@ int process_switching_rules(struct session *s, struct buffer *req, int an_bit)
 		 * backend if any.
 		 */
 		if (!(s->flags & SN_BE_ASSIGNED))
-			session_set_backend(s, s->fe->defbe.be ? s->fe->defbe.be : s->be);
+			if (!session_set_backend(s, s->fe->defbe.be ? s->fe->defbe.be : s->be))
+				goto sw_failed;
 	}
 
 	/* we don't want to run the HTTP filters again if the backend has not changed */
@@ -605,6 +607,21 @@ int process_switching_rules(struct session *s, struct buffer *req, int an_bit)
 		s->req->analysers &= ~AN_REQ_HTTP_PROCESS_BE;
 
 	return 1;
+
+ sw_failed:
+	/* immediately abort this request in case of allocation failure */
+	buffer_abort(s->req);
+	buffer_abort(s->rep);
+
+	if (!(s->flags & SN_ERR_MASK))
+		s->flags |= SN_ERR_RESOURCE;
+	if (!(s->flags & SN_FINST_MASK))
+		s->flags |= SN_FINST_R;
+
+	s->txn.status = 500;
+	s->req->analysers = 0;
+	s->req->analyse_exp = TICK_ETERNITY;
+	return 0;
 }
 
 /* Processes the client, server, request and response jobs of a session task,