From: Martin Willi <martin@revosec.ch>
Date: Wed, 17 Apr 2013 13:47:06 +0000 (+0200)
Subject: kernel-utun: implement get_nexthop() lookup using PF_ROUTE
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=cc3af6ae60b24b52d6f873094df3016230fd9f6a;p=thirdparty%2Fstrongswan.git

kernel-utun: implement get_nexthop() lookup using PF_ROUTE
---

diff --git a/src/libhydra/plugins/kernel_utun/kernel_utun_net.c b/src/libhydra/plugins/kernel_utun/kernel_utun_net.c
index 3c62e3a65f..7446340aff 100644
--- a/src/libhydra/plugins/kernel_utun/kernel_utun_net.c
+++ b/src/libhydra/plugins/kernel_utun/kernel_utun_net.c
@@ -215,12 +215,6 @@ METHOD(kernel_net_t, get_source_addr, host_t*,
 	return NULL;
 }
 
-METHOD(kernel_net_t, get_nexthop, host_t*,
-	private_kernel_utun_net_t *this, host_t *dest, host_t *src)
-{
-	return NULL;
-}
-
 METHOD(kernel_net_t, add_ip, status_t,
 	private_kernel_utun_net_t *this, host_t *virtual_ip, int prefix,
 	char *iface_name)
@@ -389,6 +383,87 @@ METHOD(kernel_net_t, del_route, status_t,
 	return manage_route(this, RTM_DELETE, dst_net, prefixlen, gateway, if_name);
 }
 
+METHOD(kernel_net_t, get_nexthop, host_t*,
+	private_kernel_utun_net_t *this, host_t *dest, host_t *src)
+{
+	struct {
+		struct rt_msghdr hdr;
+		char buf[sizeof(struct sockaddr_storage) * RTAX_MAX];
+	} msg = {
+		.hdr = {
+			.rtm_version = RTM_VERSION,
+			.rtm_type = RTM_GET,
+			.rtm_pid = this->pid,
+			.rtm_seq = ++this->seq,
+		},
+	};
+	host_t *hop = NULL;
+	struct sockaddr *addr;
+	int i, remaining;
+
+	msg.hdr.rtm_msglen = sizeof(struct rt_msghdr);
+	for (i = 0; i < RTAX_MAX; i++)
+	{
+		switch (i)
+		{
+			case RTAX_DST:
+				add_rt_addr(&msg.hdr, RTA_DST, dest);
+				break;
+			case RTAX_IFA:
+				add_rt_addr(&msg.hdr, RTA_IFA, src);
+				break;
+			default:
+				break;
+		}
+	}
+	this->mutex->lock(this->mutex);
+
+	this->waiting_seq = msg.hdr.rtm_seq;
+	if (send(this->pfr, &msg, msg.hdr.rtm_msglen, 0) == msg.hdr.rtm_msglen)
+	{
+		while (TRUE)
+		{
+			if (this->condvar->timed_wait(this->condvar, this->mutex, 1000))
+			{	/* timed out? */
+				break;
+			}
+			if (msg.hdr.rtm_seq != this->reply->rtm_seq)
+			{
+				continue;
+			}
+			remaining = this->reply->rtm_msglen - sizeof(*this->reply);
+			addr = (void*)this->reply + sizeof(*this->reply);
+			for (i = 0; i < RTAX_MAX; i++)
+			{
+				if ((1 << i & this->reply->rtm_addrs) &&
+					remaining >= sizeof(addr->sa_len) &&
+					remaining >= addr->sa_len &&
+					remaining >= sizeof(struct sockaddr))
+				{
+					switch (i)
+					{
+						case RTAX_GATEWAY:
+							hop = host_create_from_sockaddr(addr);
+							break;
+						default:
+							break;
+					}
+					addr = (void*)addr + addr->sa_len;
+					remaining -= addr->sa_len;
+				}
+			}
+			break;
+		}
+	}
+	else
+	{
+		DBG1(DBG_KNL, "PF_ROUTE lookup failed: %s", strerror(errno));
+	}
+	this->mutex->unlock(this->mutex);
+
+	return hop;
+}
+
 /**
  * Receive PF_ROUTE messages from kernel
  */