X-Git-Url: http://git.sameswireless.fr/l2tpns.git/blobdiff_plain/7aa8cc3dc0df081350a7f9b4a30ef8490ee74fe0..7c474381d4dcc23b9fb4d3a2401971a9ef79c889:/l2tpns.c?ds=sidebyside

diff --git a/l2tpns.c b/l2tpns.c
index 8230945..f530955 100644
--- a/l2tpns.c
+++ b/l2tpns.c
@@ -73,6 +73,7 @@ time_t basetime = 0;		// base clock
 char hostname[1000] = "";	// us.
 static int tunidx;		// ifr_ifindex of tun device
 int nlseqnum = 0;		// netlink sequence number
+int min_initok_nlseqnum = 0;	// minimun seq number for messages after init is ok
 static int syslog_log = 0;	// are we logging to syslog
 static FILE *log_stream = 0;	// file handle for direct logging (i.e. direct into file, not via syslog).
 uint32_t last_id = 0;		// Unique ID for radius accounting
@@ -418,16 +419,19 @@ void random_data(uint8_t *buf, int len)
 // via BGP if enabled, and stuffs it into the
 // 'sessionbyip' cache.
 //
-// 'ip' and 'mask' must be in _host_ order.
+// 'ip' must be in _host_ order.
 //
-static void routeset(sessionidt s, in_addr_t ip, in_addr_t mask, in_addr_t gw, int add)
+static void routeset(sessionidt s, in_addr_t ip, int prefixlen, in_addr_t gw, int add)
 {
 	struct rtentry r;
+	in_addr_t mask;
 	int i;
 
-	if (!mask) mask = 0xffffffff;
+	if (!prefixlen) prefixlen = 32;
 
-	ip &= mask;		// Force the ip to be the first one in the route.
+	mask = 0xffffffff << (32 - prefixlen);
+
+	ip &= mask;	// Force the ip to be the first one in the route.
 
 	memset(&r, 0, sizeof(r));
 	r.rt_dev = config->tundevice;
@@ -440,11 +444,11 @@ static void routeset(sessionidt s, in_addr_t ip, in_addr_t mask, in_addr_t gw, i
 	r.rt_flags = (RTF_UP | RTF_STATIC);
 	if (gw)
 		r.rt_flags |= RTF_GATEWAY;
-	else if (mask == 0xffffffff)
+	else if (prefixlen == 32)
 		r.rt_flags |= RTF_HOST;
 
-	LOG(1, s, 0, "Route %s %s/%s%s%s\n", add ? "add" : "del",
-	    fmtaddr(htonl(ip), 0), fmtaddr(htonl(mask), 1),
+	LOG(1, s, 0, "Route %s %s/%d%s%s\n", add ? "add" : "del",
+	    fmtaddr(htonl(ip), 0), prefixlen,
 	    gw ? " via" : "", gw ? fmtaddr(htonl(gw), 2) : "");
 
 	if (ioctl(ifrfd, add ? SIOCADDRT : SIOCDELRT, (void *) &r) < 0)
@@ -452,9 +456,9 @@ static void routeset(sessionidt s, in_addr_t ip, in_addr_t mask, in_addr_t gw, i
 
 #ifdef BGP
 	if (add)
-		bgp_add_route(htonl(ip), htonl(mask));
+		bgp_add_route(htonl(ip), prefixlen);
 	else
-		bgp_del_route(htonl(ip), htonl(mask));
+		bgp_del_route(htonl(ip), prefixlen);
 #endif /* BGP */
 
 		// Add/Remove the IPs to the 'sessionbyip' cache.
@@ -470,7 +474,7 @@ static void routeset(sessionidt s, in_addr_t ip, in_addr_t mask, in_addr_t gw, i
 		if (!add)	// Are we deleting a route?
 			s = 0;	// Caching the session as '0' is the same as uncaching.
 
-		for (i = ip; (i&mask) == (ip&mask) ; ++i)
+		for (i = ip; i < ip+(1<<(32-prefixlen)) ; ++i)
 			cache_ipmap(i, s);
 	}
 }
@@ -540,7 +544,7 @@ static void initnetlink(void)
 	}
 }
 
-static ssize_t netlink_send(struct nlmsghdr *nh, int want_ack)
+static ssize_t netlink_send(struct nlmsghdr *nh)
 {
 	struct sockaddr_nl nladdr;
 	struct iovec iov;
@@ -548,8 +552,6 @@ static ssize_t netlink_send(struct nlmsghdr *nh, int want_ack)
 
 	nh->nlmsg_pid = getpid();
 	nh->nlmsg_seq = ++nlseqnum;
-	if (want_ack)
-		nh->nlmsg_flags |= NLM_F_ACK;
 
 	// set kernel address
 	memset(&nladdr, 0, sizeof(nladdr));
@@ -561,7 +563,7 @@ static ssize_t netlink_send(struct nlmsghdr *nh, int want_ack)
 	return sendmsg(nlfd, &msg, 0);
 }
 
-static ssize_t netlink_recv(char *buf, ssize_t len)
+static ssize_t netlink_recv(void *buf, ssize_t len)
 {
 	struct sockaddr_nl nladdr;
 	struct iovec iov;
@@ -577,47 +579,35 @@ static ssize_t netlink_recv(char *buf, ssize_t len)
 	return recvmsg(nlfd, &msg, 0);
 }
 
-static ssize_t netlink_check_ack(struct nlmsghdr *ack_nh, int msg_count)
+/* adapted from iproute2 */
+void netlink_addattr(struct nlmsghdr *nh, int type, const void *data, int alen)
 {
-	ssize_t len;
-	uint32_t seqnum;
-
-	// expect ack
-	for (; NLMSG_OK (ack_nh, len); ack_nh = NLMSG_NEXT (ack_nh, len))
-	{
-		if (ack_nh->nlmsg_type == NLMSG_DONE)
-			return msg_count != 0 || seqnum != nlseqnum;
-			// 1 => lost an ack
-
-		if (ack_nh->nlmsg_type == NLMSG_ERROR)
-		{
-			struct nlmsgerr *errmsg = NLMSG_DATA(ack_nh);
-			if (errmsg->error)
-				return errmsg->error; // got an error back
-			else
-			{
-				// ack received
-				--msg_count;
-				if (errmsg->msg.nlmsg_seq > seqnum);
-					seqnum = errmsg->msg.nlmsg_seq;
-			}
-		}
-		else
-			// unknown message
-			LOG(3, 0, 0, "Got an unknown netlink message: type %d\n", ack_nh->nlmsg_type);
-	}
-
-	return 1; // malformed message?!
+	int len = RTA_LENGTH(alen);
+	struct rtattr *rta;
+
+	rta = (struct rtattr *)(((void *)nh) + NLMSG_ALIGN(nh->nlmsg_len));
+	rta->rta_type = type;
+	rta->rta_len = len;
+	memcpy(RTA_DATA(rta), data, alen);
+	nh->nlmsg_len = NLMSG_ALIGN(nh->nlmsg_len) + RTA_ALIGN(len);
 }
 
+// messages corresponding to different phases seq number
+static char *tun_nl_phase_msg[] = {
+	"initialized",
+	"getting tun interface index",
+	"setting tun interface parameters",
+	"setting tun IPv4 address",
+	"setting tun LL IPv6 address",
+	"setting tun global IPv6 address",
+};
+
 //
 // Set up TUN interface
 static void inittun(void)
 {
 	struct ifinfomsg ifinfo;
 	struct ifreq ifr;
-	char buf[4096];
-	struct nlmsghdr resp_nh;
 
 	memset(&ifr, 0, sizeof(ifr));
 	ifr.ifr_flags = IFF_TUN;
@@ -637,188 +627,164 @@ static void inittun(void)
 		LOG(0, 0, 0, "Can't set tun interface: %s\n", strerror(errno));
 		exit(1);
 	}
-	assert(strlen(ifr.ifr_name) < sizeof(config->tundevice));
-	strncpy(config->tundevice, ifr.ifr_name, sizeof(config->tundevice) - 1);
+	assert(strlen(ifr.ifr_name) < sizeof(config->tundevice) - 1);
+	strncpy(config->tundevice, ifr.ifr_name, sizeof(config->tundevice));
 
 	{
 		// get the interface index
-		ssize_t len;
 		struct {
 			struct nlmsghdr nh;
 			struct ifinfomsg ifinfo __attribute__ ((aligned(NLMSG_ALIGNTO)));
 			struct rtattr ifname_rta __attribute__ ((aligned(RTA_ALIGNTO)));
 			char ifname[IFNAMSIZ];
 		} req;
+		char buf[4096];
+		ssize_t len;
+		struct nlmsghdr *resp_nh;
 
 		req.nh.nlmsg_type = RTM_GETLINK;
 		req.nh.nlmsg_flags = NLM_F_REQUEST;
+		req.nh.nlmsg_len = NLMSG_LENGTH(sizeof(req.ifinfo));
 
 		req.ifinfo.ifi_family = AF_UNSPEC; // as the man says
 
-		req.ifname_rta.rta_len = RTA_LENGTH(strlen(config->tundevice)+1);
-		req.ifname_rta.rta_type = IFLA_IFNAME;
-		strncpy(req.ifname, config->tundevice, IFNAMSIZ-1);
+		netlink_addattr(&req.nh, IFLA_IFNAME, config->tundevice, strlen(config->tundevice)+1);
 
-		if(netlink_send(&req.nh, 0) < 0 || (len = netlink_recv(buf, sizeof(buf))) < 0)
+		if(netlink_send(&req.nh) < 0 || (len = netlink_recv(buf, sizeof(buf))) < 0)
 		{
 			LOG(0, 0, 0, "Error getting tun ifindex: %s\n", strerror(errno));
 			exit(1);
 		}
 
 		resp_nh = (struct nlmsghdr *)buf;
-		if (NLMSG_OK (resp_nh, len) && resp_nh.nlmsg_type == RTM_GETLINK)
-		{
-			memcpy(&ifinfo, NLMSG_DATA(resp_nh), sizeof(ifinfo));
-			// got index
-			tunidx = ifinfo.ifi_index;
-		}
-		else
+		if (!NLMSG_OK (resp_nh, len))
 		{
-			LOG(0, 0, 0, "Malformed answer getting tun ifindex\n");
+			LOG(0, 0, 0, "Malformed answer getting tun ifindex %ld\n", len);
 			exit(1);
 		}
+
+		memcpy(&ifinfo, NLMSG_DATA(resp_nh), sizeof(ifinfo));
+		// got index
+		tunidx = ifinfo.ifi_index;
 	}
 	{
-		ssize_t err;
 		struct {
 			// interface setting
 			struct nlmsghdr nh;
-			struct ifinfomsg ifinfo __attribute__ ((aligned(NLMSG_ALIGNTO)));
-			struct rtattr txqlen_rta __attribute__ ((aligned(RTA_ALIGNTO)));
-			uint32_t txqlen;
-			struct rtattr mtu_rta __attribute__ ((aligned(RTA_ALIGNTO)));
-			uint32_t mtu;
-
-			// IPv4 address
-			struct nlmsghdr addr_nh __attribute __ ((aligned(NLMSG_ALIGNTO)));
-			struct ifaddrmsg ifaddr __attribute __ ((aligned(NLMSG_ALIGNTO)));
-			struct rtattr addr_rta __attribute __ ((aligned(RTA_ALIGNTO)));
-			struct in_addr addr;
-
-			// IPv6 LL address
-			struct nlmsghdr lladdr6_nh __attribute __ ((aligned(NLMSG_ALIGNTO)));
-			struct ifaddrmsg llifaddr6 __attribute __ ((aligned(NLMSG_ALIGNTO)));
-			struct rtattr lladdr6_rta __attribute __ ((aligned(RTA_ALIGNTO)));
-			struct in6_addr lladdr6;
-
-			// IPv6 global address
-			struct nlmsghdr addr6_nh __attribute __ ((aligned(NLMSG_ALIGNTO)));
-			struct ifaddrmsg ifaddr6 __attribute __ ((aligned(NLMSG_ALIGNTO)));
-			struct rtattr addr6_rta __attribute __ ((aligned(RTA_ALIGNTO)));
-			struct in6_addr addr6;
-
-			// end header
-			struct nlmsghdr end_nh __attribute __ ((aligned(NLMSG_ALIGNTO)));
+			union {
+				struct ifinfomsg ifinfo;
+				struct ifaddrmsg ifaddr;
+			} ifmsg __attribute__ ((aligned(NLMSG_ALIGNTO)));
+			char rtdata[32]; // 32 should be enough
 		} req;
-		char buf[4096];
+		uint32_t txqlen, mtu;
+		struct in_addr ip;
 
 		memset(&req, 0, sizeof(req));
 
-		req.nh.nlmsg_type = RTM_NEWLINK;
-		req.nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_REPLACE | NLM_F_MULTI;
+		req.nh.nlmsg_type = RTM_SETLINK;
+		req.nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_MULTI;
+		req.nh.nlmsg_len = NLMSG_LENGTH(sizeof(req.ifmsg.ifinfo));
 
-		req.ifinfo = ifinfo;
-		req.ifinfo.ifi_flags |= IFF_UP; // set interface up
-		req.ifinfo.ifi_change = IFF_UP; // only change this flag
+		req.ifmsg.ifinfo = ifinfo;
+		req.ifmsg.ifinfo.ifi_flags |= IFF_UP; // set interface up
+		req.ifmsg.ifinfo.ifi_change = IFF_UP; // only change this flag
 
-		req.txqlen_rta.rta_len = RTA_LENGTH(sizeof(req.txqlen));
-		req.txqlen_rta.rta_type = IFLA_TXQLEN;
 		/* Bump up the qlen to deal with bursts from the network */
-		req.txqlen = 1000;
-
-		req.mtu_rta.rta_len = RTA_LENGTH(sizeof(req.txqlen));
-		req.mtu_rta.rta_type = IFLA_MTU;
+		txqlen = 1000;
+		netlink_addattr(&req.nh, IFLA_TXQLEN, &txqlen, sizeof(txqlen));
 		/* set MTU to modem MRU */
-		req.mtu = MRU;
+		mtu = MRU;
+		netlink_addattr(&req.nh, IFLA_MTU, &mtu, sizeof(mtu));
 
-		req.nh.nlmsg_len = NLMSG_LENGTH(sizeof(req.ifinfo)
-				+ req.txqlen_rla.rta_len
-				+ req.mtu_rta.rta_len);
+		if (netlink_send(&req.nh) < 0)
+			goto senderror;
 
-		req.addr_nh.nlmsg_type = RTM_NEWADDR;
-		req.addr_nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_CREATE | NLM_F_MULTI;
+		memset(&req, 0, sizeof(req));
+
+		req.nh.nlmsg_type = RTM_NEWADDR;
+		req.nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_CREATE | NLM_F_MULTI;
+		req.nh.nlmsg_len = NLMSG_LENGTH(sizeof(req.ifmsg.ifaddr));
 
-		req.ifaddr.ifa_family = AF_INET;
-		req.ifaddr.ifa_prefixlen = 32;
-		req.ifaddr.ifa_index = ifinfo.ifi_index;
+		req.ifmsg.ifaddr.ifa_family = AF_INET;
+		req.ifmsg.ifaddr.ifa_prefixlen = 32;
+		req.ifmsg.ifaddr.ifa_index = ifinfo.ifi_index;
 
-		req.addr_rta.rta_len = RTA_LENGTH(sizeof(req.addr));
-		req.addr_rta.rta_type = IFA_ADDRESS;
-		req.addr.s_addr = config->bind_address ?
-			config->bind_address : 0x01010101; // 1.1.1.1
+		if (config->bind_address)
+			ip.s_addr = config->bind_address;
+		else
+			ip.s_addr = 0x01010101, // 1.1.1.1
+		netlink_addattr(&req.nh, IFA_LOCAL, &ip, sizeof(ip));
 
-		req.addr_nh.nlmsg_len = NLMSG_LENGTH(sizeof(req.ifaddr)
-				+ req.addr_rta.rta_len);
+		if (netlink_send(&req.nh) < 0)
+			goto senderror;
 
 		// Only setup IPv6 on the tun device if we have a configured prefix
 		if (config->ipv6_prefix.s6_addr[0]) {
-			req.lladdr6_nh.nlmsg_type = RTM_NEWADDR;
-			req.lladdr6_nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_CREATE | NLM_F_MULTI;
+			struct in6_addr ip6;
+
+			memset(&req, 0, sizeof(req));
 
-			req.llifaddr6.ifa_family = AF_INET6;
-			req.llifaddr6.ifa_prefixlen = 64;
-			req.llifaddr6.ifa_scope = RT_SCOPE_LINK;
-			req.llifaddr6.ifa_index = ifinfo.ifi_index;
+			req.nh.nlmsg_type = RTM_NEWADDR;
+			req.nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_CREATE | NLM_F_MULTI;
+			req.nh.nlmsg_len = NLMSG_LENGTH(sizeof(req.ifmsg.ifaddr));
+
+			req.ifmsg.ifaddr.ifa_family = AF_INET6;
+			req.ifmsg.ifaddr.ifa_prefixlen = 64;
+			req.ifmsg.ifaddr.ifa_scope = RT_SCOPE_LINK;
+			req.ifmsg.ifaddr.ifa_index = ifinfo.ifi_index;
 
-			req.lladdr6_rta.rta_len = RTA_LENGTH(sizeof(req.lladdr6));
-			req.lladdr6_rta.rta_type = IFA_LOCAL;
 			// Link local address is FE80::1
-			memset(&req.lladdr6, 0, sizeof(req.lladdr6));
-			req.lladdr6.s6_addr[0] = 0xFE;
-			req.lladdr6.s6_addr[1] = 0x80;
-			req.lladdr6.s6_addr[15] = 1;
+			memset(&ip6, 0, sizeof(ip6));
+			ip6.s6_addr[0] = 0xFE;
+			ip6.s6_addr[1] = 0x80;
+			ip6.s6_addr[15] = 1;
+			netlink_addattr(&req.nh, IFA_LOCAL, &ip6, sizeof(ip6));
 
-			req.lladdr6_nh.nlmsg_len = NLMSG_LENGTH(sizeof(req.ifaddr)
-					+ req.lladdr6_rta.rta_len);
+			if (netlink_send(&req.nh) < 0)
+				goto senderror;
 
-			req.addr6_nh.nlmsg_type = RTM_NEWADDR;
-			req.addr6_nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_CREATE | NLM_F_MULTI;
+			memset(&req, 0, sizeof(req));
 
-			req.ifaddr6.ifa_family = AF_INET6;
-			req.ifaddr6.ifa_prefixlen = 64;
-			req.ifaddr6.ifa_scope = RT_SCOPE_UNIVERSE;
-			req.ifaddr6.ifa_index = ifinfo.ifi_index;
+			req.nh.nlmsg_type = RTM_NEWADDR;
+			req.nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_CREATE | NLM_F_MULTI;
+			req.nh.nlmsg_len = NLMSG_LENGTH(sizeof(req.ifmsg.ifaddr));
 
-			req.addr6_rta.rta_len = RTA_LENGTH(sizeof(req.addr6));
-			req.addr6_rta.rta_type = IFA_LOCAL;
-			// Global address is prefix::1
-			req.addr6 = config->ipv6_prefix;
-			req.addr6.s6_addr[15] = 1;
+			req.ifmsg.ifaddr.ifa_family = AF_INET6;
+			req.ifmsg.ifaddr.ifa_prefixlen = 64;
+			req.ifmsg.ifaddr.ifa_scope = RT_SCOPE_UNIVERSE;
+			req.ifmsg.ifaddr.ifa_index = ifinfo.ifi_index;
 
-			req.lladdr6_nh.nlmsg_len = NLMSG_LENGTH(sizeof(req.ifaddr)
-					+ req.lladdr6_rta.rta_len);
+			// Global address is prefix::1
+			ip6 = config->ipv6_prefix;
+			ip6.s6_addr[15] = 1;
+			netlink_addattr(&req.nh, IFA_LOCAL, &ip6, sizeof(ip6));
 
-			req.end_nh.nlmsg_type = NLMSG_DONE;
-			req.end_nh.nlmsg_len = NLMSG_LENGTH(0);
-		}
-		else
-		{
-			// we terminate at the beginning of IPv6 stuff
-			req.lladdr6_nh.nlmsg_type = NLMSG_DONE;
-			req.lladdr6_nh.nlmsg_len = NLMSG_LENGTH(0);
+			if (netlink_send(&req.nh) < 0)
+				goto senderror;
 		}
 
-		if (netlink_send(&req.nh, 1) < 0)
-			LOG(0, 0, 0, "Error setting up tun device: %s\n", strerror(errno));
-			exit(1);
-		}
+		memset(&req, 0, sizeof(req));
 
-		if (netlink_recv(buf, sizeof(buf)) < 0)
-		{
-			LOG(0, 0, 0, "Error waiting ack for setting up tun device: %s\n", strerror(errno));
-			exit(1);
-		}
+		req.nh.nlmsg_type = NLMSG_DONE;
+		req.nh.nlmsg_len = NLMSG_LENGTH(0);
 
-		resp_nh = (struct nlmsghdr *)buf;
-		if ((err = netlink_check_ack(resp_nh, 4)))
-		{
-			if (err < 0)
-				LOG(0, 0, 0, "Error while receiving tun device ack: %s\n", strerror(errno));
-			else
-				LOG(0, 0, 0, "Error while receiving tun device ack\n", strerror(errno));
-			exit(1);
-		}
+		if (netlink_send(&req.nh) < 0)
+			goto senderror;
+
+		// if we get an error for seqnum < min_initok_nlseqnum,
+		// we must exit as initialization went wrong
+		if (config->ipv6_prefix.s6_addr[0])
+			min_initok_nlseqnum = 5 + 1; // idx + if + addr + 2*addr6
+		else
+			min_initok_nlseqnum = 3 + 1; // idx + if + addr
 	}
+
+	return;
+
+senderror:
+	LOG(0, 0, 0, "Error while setting up tun device: %s\n", strerror(errno));
+	exit(1);
 }
 
 // set up UDP ports
@@ -1964,11 +1930,11 @@ void sessionshutdown(sessionidt s, char const *reason, int cdn_result, int cdn_e
 		int routed = 0;
 		for (r = 0; r < MAXROUTE && session[s].route[r].ip; r++)
 		{
-			if ((session[s].ip & session[s].route[r].mask) ==
-			    (session[s].route[r].ip & session[s].route[r].mask))
+			if ((session[s].ip >> (32-session[s].route[r].prefixlen)) ==
+			    (session[s].route[r].ip >> (32-session[s].route[r].prefixlen)))
 				routed++;
 
-			if (del_routes) routeset(s, session[s].route[r].ip, session[s].route[r].mask, 0, 0);
+			if (del_routes) routeset(s, session[s].route[r].ip, session[s].route[r].prefixlen, 0, 0);
 			session[s].route[r].ip = 0;
 		}
 
@@ -3694,8 +3660,8 @@ static int still_busy(void)
 # include "fake_epoll.h"
 #endif
 
-// the base set of fds polled: cli, cluster, tun, udp, control, dae
-#define BASE_FDS	6
+// the base set of fds polled: cli, cluster, tun, udp, control, dae, netlink
+#define BASE_FDS	7
 
 // additional polled fds
 #ifdef BGP
@@ -3719,8 +3685,8 @@ static void mainloop(void)
 		exit(1);
 	}
 
-	LOG(4, 0, 0, "Beginning of main loop.  clifd=%d, cluster_sockfd=%d, tunfd=%d, udpfd=%d, controlfd=%d, daefd=%d\n",
-		clifd, cluster_sockfd, tunfd, udpfd, controlfd, daefd);
+	LOG(4, 0, 0, "Beginning of main loop.  clifd=%d, cluster_sockfd=%d, tunfd=%d, udpfd=%d, controlfd=%d, daefd=%d, nlfd=%d\n",
+		clifd, cluster_sockfd, tunfd, udpfd, controlfd, daefd, nlfd);
 
 	/* setup our fds to poll for input */
 	{
@@ -3756,6 +3722,10 @@ static void mainloop(void)
 		d[i].type = FD_TYPE_DAE;
 		e.data.ptr = &d[i++];
 		epoll_ctl(epollfd, EPOLL_CTL_ADD, daefd, &e);
+
+		d[i].type = FD_TYPE_NETLINK;
+		e.data.ptr = &d[i++];
+		epoll_ctl(epollfd, EPOLL_CTL_ADD, nlfd, &e);
 	}
 
 #ifdef BGP
@@ -3892,6 +3862,32 @@ static void mainloop(void)
 					break;
 #endif /* BGP */
 
+				case FD_TYPE_NETLINK:
+				{
+					struct nlmsghdr *nh = (struct nlmsghdr *)buf;
+					s = netlink_recv(buf, sizeof(buf));
+					if (nh->nlmsg_type == NLMSG_ERROR)
+					{
+						struct nlmsgerr *errmsg = NLMSG_DATA(nh);
+						if (errmsg->error)
+						{
+							if (errmsg->msg.nlmsg_seq < min_initok_nlseqnum)
+							{
+								LOG(0, 0, 0, "Got a fatal netlink error (while %s): %s\n", tun_nl_phase_msg[nh->nlmsg_seq], strerror(-errmsg->error));
+								exit(1);
+							}
+							else
+
+								LOG(0, 0, 0, "Got a netlink error: %s\n", strerror(-errmsg->error));
+						}
+						// else it's a ack
+					}
+					else
+						LOG(1, 0, 0, "Got a unknown netlink message: type %d seq %d flags %d\n", nh->nlmsg_type, nh->nlmsg_seq, nh->nlmsg_flags);
+					n--;
+					break;
+				}
+
 				default:
 				    	LOG(0, 0, 0, "Unexpected fd type returned from epoll_wait: %d\n", d->type);
 				}
@@ -4450,18 +4446,18 @@ static void fix_address_pool(int sid)
 //
 // Add a block of addresses to the IP pool to hand out.
 //
-static void add_to_ip_pool(in_addr_t addr, in_addr_t mask)
+static void add_to_ip_pool(in_addr_t addr, int prefixlen)
 {
 	int i;
-	if (mask == 0)
-		mask = 0xffffffff;	// Host route only.
+	if (prefixlen == 0)
+		prefixlen = 32;		// Host route only.
 
-	addr &= mask;
+	addr &= 0xffffffff << (32 - prefixlen);
 
 	if (ip_pool_size >= MAXIPPOOL)	// Pool is full!
 		return ;
 
-	for (i = addr ;(i & mask) == addr; ++i)
+	for (i = addr ; i < addr+(1<<(32-prefixlen)); ++i)
 	{
 		if ((i & 0xff) == 0 || (i&0xff) == 255)
 			continue;	// Skip 0 and broadcast addresses.
@@ -4519,7 +4515,7 @@ static void initippool()
 		{
 			// It's a range
 			int numbits = 0;
-			in_addr_t start = 0, mask = 0;
+			in_addr_t start = 0;
 
 			LOG(2, 0, 0, "Adding IP address range %s\n", buf);
 			*p++ = 0;
@@ -4529,15 +4525,14 @@ static void initippool()
 				continue;
 			}
 			start = ntohl(inet_addr(pool));
-			mask = (in_addr_t) (pow(2, numbits) - 1) << (32 - numbits);
 
 			// Add a static route for this pool
-			LOG(5, 0, 0, "Adding route for address pool %s/%u\n",
-				fmtaddr(htonl(start), 0), 32 + mask);
+			LOG(5, 0, 0, "Adding route for address pool %s/%d\n",
+				fmtaddr(htonl(start), 0), numbits);
 
-			routeset(0, start, mask, 0, 1);
+			routeset(0, start, numbits, 0, 1);
 
-			add_to_ip_pool(start, mask);
+			add_to_ip_pool(start, numbits);
 		}
 		else
 		{
@@ -4733,6 +4728,8 @@ int main(int argc, char *argv[])
 		}
 	}
 
+	initnetlink();
+
 	/* Set up the cluster communications port. */
 	if (cluster_init() < 0)
 		exit(1);
@@ -5184,11 +5181,11 @@ int sessionsetup(sessionidt s, tunnelidt t)
 		// Add the route for this session.
 		for (r = 0; r < MAXROUTE && session[s].route[r].ip; r++)
 		{
-			if ((session[s].ip & session[s].route[r].mask) ==
-			    (session[s].route[r].ip & session[s].route[r].mask))
+			if ((session[s].ip >> (32-session[s].route[r].prefixlen)) ==
+			    (session[s].route[r].ip >> (32-session[s].route[r].prefixlen)))
 				routed++;
 
-			routeset(s, session[s].route[r].ip, session[s].route[r].mask, 0, 1);
+			routeset(s, session[s].route[r].ip, session[s].route[r].prefixlen, 0, 1);
 		}
 
 		// Static IPs need to be routed if not already
@@ -5259,7 +5256,7 @@ int load_session(sessionidt s, sessiont *new)
 
 	for (i = 0; !newip && i < MAXROUTE && (session[s].route[i].ip || new->route[i].ip); i++)
 		if (new->route[i].ip != session[s].route[i].ip ||
-		    new->route[i].mask != session[s].route[i].mask)
+		    new->route[i].prefixlen != session[s].route[i].prefixlen)
 			newip++;
 
 	// needs update
@@ -5270,11 +5267,11 @@ int load_session(sessionidt s, sessiont *new)
 		// remove old routes...
 		for (i = 0; i < MAXROUTE && session[s].route[i].ip; i++)
 		{
-			if ((session[s].ip & session[s].route[i].mask) ==
-			    (session[s].route[i].ip & session[s].route[i].mask))
+			if ((session[s].ip >> (32-session[s].route[i].prefixlen)) ==
+			    (session[s].route[i].ip >> (32-session[s].route[i].prefixlen)))
 				routed++;
 
-			routeset(s, session[s].route[i].ip, session[s].route[i].mask, 0, 0);
+			routeset(s, session[s].route[i].ip, session[s].route[i].prefixlen, 0, 0);
 		}
 
 		// ...ip
@@ -5293,11 +5290,11 @@ int load_session(sessionidt s, sessiont *new)
 		// add new routes...
 		for (i = 0; i < MAXROUTE && new->route[i].ip; i++)
 		{
-			if ((new->ip & new->route[i].mask) ==
-			    (new->route[i].ip & new->route[i].mask))
+			if ((new->ip >> (32-new->route[i].prefixlen)) ==
+			    (new->route[i].ip >> (32-new->route[i].prefixlen)))
 				routed++;
 
-			routeset(s, new->route[i].ip, new->route[i].mask, 0, 1);
+			routeset(s, new->route[i].ip, new->route[i].prefixlen, 0, 1);
 		}
 
 		// ...ip