From 374917adccb955fbb2796955166fabe46a09e096 Mon Sep 17 00:00:00 2001
From: Ondrej Zajicek <santiago@crfreenet.org>
Date: Sat, 21 Feb 2015 20:39:59 +0100
Subject: [PATCH] Make BGP protocol instance search a separate function

Thanks to Alexander V. Chernikov for the patch.
---
 proto/bgp/bgp.c | 106 ++++++++++++++++++++++++++++--------------------
 1 file changed, 63 insertions(+), 43 deletions(-)

diff --git a/proto/bgp/bgp.c b/proto/bgp/bgp.c
index b852da04..c8b1867b 100644
--- a/proto/bgp/bgp.c
+++ b/proto/bgp/bgp.c
@@ -712,6 +712,28 @@ bgp_connect(struct bgp_proto *p)	/* Enter Connect state and start establishing c
   return;
 }
 
+/**
+ * bgp_find_proto - find existing proto for incoming connection
+ * @sk: TCP socket
+ *
+ */
+static struct bgp_proto *
+bgp_find_proto(sock *sk)
+{
+  struct proto_config *pc;
+
+  WALK_LIST(pc, config->protos)
+    if ((pc->protocol == &proto_bgp) && pc->proto)
+      {
+	struct bgp_proto *p = (struct bgp_proto *) pc->proto;
+	if (ipa_equal(p->cf->remote_ip, sk->daddr) &&
+	    (!ipa_is_link_local(sk->daddr) || (p->cf->iface == sk->iface)))
+	  return p;
+      }
+
+  return NULL;
+}
+
 /**
  * bgp_incoming_connection - handle an incoming connection
  * @sk: TCP socket
@@ -727,60 +749,58 @@ bgp_connect(struct bgp_proto *p)	/* Enter Connect state and start establishing c
 static int
 bgp_incoming_connection(sock *sk, int dummy UNUSED)
 {
-  struct proto_config *pc;
+  struct bgp_proto *p;
+  int acc, hops;
 
   DBG("BGP: Incoming connection from %I port %d\n", sk->daddr, sk->dport);
-  WALK_LIST(pc, config->protos)
-    if (pc->protocol == &proto_bgp && pc->proto)
-      {
-	struct bgp_proto *p = (struct bgp_proto *) pc->proto;
-	if (ipa_equal(p->cf->remote_ip, sk->daddr) &&
-	    (!ipa_is_link_local(sk->daddr) || (p->cf->iface == sk->iface)))
-	  {
-	    /* We are in proper state and there is no other incoming connection */
-	    int acc = (p->p.proto_state == PS_START || p->p.proto_state == PS_UP) &&
-	      (p->start_state >= BSS_CONNECT) && (!p->incoming_conn.sk);
+  p = bgp_find_proto(sk);
+  if (!p)
+    {
+      log(L_WARN "BGP: Unexpected connect from unknown address %I%J (port %d)",
+	  sk->daddr, ipa_is_link_local(sk->daddr) ? sk->iface : NULL, sk->dport);
+      rfree(sk);
+      return 0;
+    }
 
-	    if (p->conn && (p->conn->state == BS_ESTABLISHED) && p->gr_ready)
-	    {
-	      bgp_store_error(p, NULL, BE_MISC, BEM_GRACEFUL_RESTART);
-	      bgp_handle_graceful_restart(p);
-	      bgp_conn_enter_idle_state(p->conn);
-	      acc = 1;
-	    }
+  /* We are in proper state and there is no other incoming connection */
+  acc = (p->p.proto_state == PS_START || p->p.proto_state == PS_UP) &&
+    (p->start_state >= BSS_CONNECT) && (!p->incoming_conn.sk);
 
-	    BGP_TRACE(D_EVENTS, "Incoming connection from %I%J (port %d) %s",
-		      sk->daddr, ipa_is_link_local(sk->daddr) ? sk->iface : NULL,
-		      sk->dport, acc ? "accepted" : "rejected");
+  if (p->conn && (p->conn->state == BS_ESTABLISHED) && p->gr_ready)
+    {
+      bgp_store_error(p, NULL, BE_MISC, BEM_GRACEFUL_RESTART);
+      bgp_handle_graceful_restart(p);
+      bgp_conn_enter_idle_state(p->conn);
+      acc = 1;
+    }
 
-	    if (!acc)
-	      goto reject;
+  BGP_TRACE(D_EVENTS, "Incoming connection from %I%J (port %d) %s",
+	    sk->daddr, ipa_is_link_local(sk->daddr) ? sk->iface : NULL,
+	    sk->dport, acc ? "accepted" : "rejected");
 
-	    int hops = p->cf->multihop ? : 1;
+  if (!acc)
+    {
+      rfree(sk);
+      return 0;
+    }
 
-	    if (sk_set_ttl(sk, p->cf->ttl_security ? 255 : hops) < 0)
-	      goto err;
+  hops = p->cf->multihop ? : 1;
 
-	    if (p->cf->ttl_security)
-	      if (sk_set_min_ttl(sk, 256 - hops) < 0)
-		goto err;
+  if (sk_set_ttl(sk, p->cf->ttl_security ? 255 : hops) < 0)
+    goto err;
 
-	    bgp_setup_conn(p, &p->incoming_conn);
-	    bgp_setup_sk(&p->incoming_conn, sk);
-	    bgp_send_open(&p->incoming_conn);
-	    return 0;
+  if (p->cf->ttl_security)
+    if (sk_set_min_ttl(sk, 256 - hops) < 0)
+      goto err;
 
-	  err:
-	    sk_log_error(sk, p->p.name);
-	    log(L_ERR "%s: Incoming connection aborted", p->p.name);
-	    rfree(sk);
-	    return 0;
-	  }
-      }
+  bgp_setup_conn(p, &p->incoming_conn);
+  bgp_setup_sk(&p->incoming_conn, sk);
+  bgp_send_open(&p->incoming_conn);
+  return 0;
 
-  log(L_WARN "BGP: Unexpected connect from unknown address %I%J (port %d)",
-      sk->daddr, ipa_is_link_local(sk->daddr) ? sk->iface : NULL, sk->dport);
- reject:
+err:
+  sk_log_error(sk, p->p.name);
+  log(L_ERR "%s: Incoming connection aborted", p->p.name);
   rfree(sk);
   return 0;
 }