From 80bea2db90a90b6743078fde097003e48a4a9c8d Mon Sep 17 00:00:00 2001
From: Linus Nordberg <linus@nordberg.se>
Date: Wed, 16 Oct 2019 11:19:14 +0200
Subject: WIP

---
 lease.c             | 30 +++++++++++++++++++++++++-----
 lease.h             |  4 ++--
 tests/netsh.sh      |  2 +-
 wg-dynamic-server.c |  4 ++--
 4 files changed, 30 insertions(+), 10 deletions(-)

diff --git a/lease.c b/lease.c
index 2915736..b7258ef 100644
--- a/lease.c
+++ b/lease.c
@@ -52,7 +52,7 @@ static time_t get_monotonic_time()
 	return monotime.tv_sec;
 }
 
-void leases_init(char *fname, struct mnl_socket *nlsock)
+void leases_init(char *fname, struct mnl_socket *nlsock, uint32_t ifindex)
 {
 	struct nlmsghdr *nlh;
 	struct rtmsg *rtm;
@@ -73,7 +73,7 @@ void leases_init(char *fname, struct mnl_socket *nlsock)
 	if (mnl_socket_sendto(nlsock, nlh, nlh->nlmsg_len) < 0)
 		fatal("mnl_socket_sendto()");
 
-	leases_update_pools(nlsock);
+	leases_update_pools(nlsock, ifindex);
 	synchronized = true;
 
 	UNUSED(fname); /* TODO: open file and initialize from it */
@@ -446,6 +446,12 @@ static int data_ipv4_attr_cb(const struct nlattr *attr, void *data)
 			return MNL_CB_ERROR;
 		}
 		break;
+	case RTA_OIF:
+		if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0) {
+			log_err("mnl_attr_validate: %s\n", strerror(errno));
+			return MNL_CB_ERROR;
+		}
+		break;
 	default:
 		return MNL_CB_OK;
 	}
@@ -467,6 +473,12 @@ static int data_ipv6_attr_cb(const struct nlattr *attr, void *data)
 			return MNL_CB_ERROR;
 		}
 		break;
+	case RTA_OIF:
+		if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0) {
+			log_err("mnl_attr_validate: %s\n", strerror(errno));
+			return MNL_CB_ERROR;
+		}
+		break;
 	default:
 		return MNL_CB_OK;
 	}
@@ -478,13 +490,21 @@ static int process_nlpacket_cb(const struct nlmsghdr *nlh, void *data)
 {
 	struct nlattr *tb[RTA_MAX + 1] = {};
 	struct rtmsg *rm = mnl_nlmsg_get_payload(nlh);
-	UNUSED(data);
+	uint32_t ifindex;
+
+	BUG_ON(!data);
+	ifindex = *((int *) data);
 
 	if (rm->rtm_family == AF_INET)
 		mnl_attr_parse(nlh, sizeof(*rm), data_ipv4_attr_cb, tb);
 	else if (rm->rtm_family == AF_INET6)
 		mnl_attr_parse(nlh, sizeof(*rm), data_ipv6_attr_cb, tb);
 
+	if (!tb[RTA_OIF] || mnl_attr_get_u32(tb[RTA_OIF]) != ifindex) {
+		debug("ignoring interface %u (want %u)\n", tb[RTA_OIF] ? mnl_attr_get_u32(tb[RTA_OIF]) : 0, ifindex);
+	  	return MNL_CB_OK;
+	}
+
 	if (tb[RTA_GATEWAY])
 		return MNL_CB_OK;
 
@@ -519,13 +539,13 @@ static int process_nlpacket_cb(const struct nlmsghdr *nlh, void *data)
 	return MNL_CB_OK;
 }
 
-void leases_update_pools(struct mnl_socket *nlsock)
+void leases_update_pools(struct mnl_socket *nlsock, uint32_t ifindex)
 {
 	int ret;
 	char buf[MNL_SOCKET_BUFFER_SIZE];
 
 	while ((ret = mnl_socket_recvfrom(nlsock, buf, sizeof buf)) > 0) {
-		if (mnl_cb_run(buf, ret, 0, 0, process_nlpacket_cb, NULL) == -1)
+		if (mnl_cb_run(buf, ret, 0, 0, process_nlpacket_cb, (void *) &ifindex) == -1)
 			fatal("mnl_cb_run()");
 	}
 
diff --git a/lease.h b/lease.h
index 383bac7..cfb1a16 100644
--- a/lease.h
+++ b/lease.h
@@ -28,7 +28,7 @@ struct wg_dynamic_lease {
  * Initializes internal state, retrieves routes from nlsock and reads leases
  * from fname.
  */
-void leases_init(char *fname, struct mnl_socket *nlsock);
+void leases_init(char *fname, struct mnl_socket *nlsock, uint32_t ifindex);
 
 /*
  * Frees everything, closes file.
@@ -67,7 +67,7 @@ void update_allowed_ips(const char *devname, wg_key peer_pubkey,
 /*
  * Updates all pools with information from the mnl socket nlsock.
  */
-void leases_update_pools(struct mnl_socket *nlsock);
+void leases_update_pools(struct mnl_socket *nlsock, uint32_t ifindex);
 
 /*
  * Return true if lease is !NULL and has not expired.
diff --git a/tests/netsh.sh b/tests/netsh.sh
index f9e9c1e..37d174e 100755
--- a/tests/netsh.sh
+++ b/tests/netsh.sh
@@ -86,4 +86,4 @@ echo
 echo wg-test-$$ $server_public
 echo
 
-nn 1 ./wg-dynamic-server --leasetime 10 wg0
+nn 1 gdb -ex r --args ./wg-dynamic-server --leasetime 10 wg0
diff --git a/wg-dynamic-server.c b/wg-dynamic-server.c
index feb9656..942deea 100644
--- a/wg-dynamic-server.c
+++ b/wg-dynamic-server.c
@@ -439,7 +439,7 @@ static void setup()
 		    wg_interface);
 
 	setup_sockets();
-	leases_init(NULL, nlsock);
+	leases_init(NULL, nlsock, device->ifindex);
 	init_leaess_from_peers();
 }
 
@@ -493,7 +493,7 @@ static void handle_event(void *ptr, uint32_t events)
 	}
 
 	if (ptr == nlsock) {
-		leases_update_pools(nlsock);
+		leases_update_pools(nlsock, device->ifindex);
 		return;
 	}
 
-- 
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