X-Git-Url: https://git.decadent.org.uk/gitweb/?p=odhcp6c.git;a=blobdiff_plain;f=src%2Fra.c;h=ceded54ab9340c90be76b19b3802c0bad576bfa9;hp=c870279abae3f70730dc3aee17719a25168df726;hb=b4d90de3204d4b7b813f0e1bc0019b8607a29c9f;hpb=d77cbea57d1b7dd9c25421bb13c90e65bb54a6bc

diff --git a/src/ra.c b/src/ra.c
index c870279..ceded54 100644
--- a/src/ra.c
+++ b/src/ra.c
@@ -29,13 +29,26 @@
 
 #include <linux/rtnetlink.h>
 
+#ifndef SOL_NETLINK
+#define SOL_NETLINK 270
+#endif
+
+#ifndef NETLINK_ADD_MEMBERSHIP
+#define NETLINK_ADD_MEMBERSHIP 1
+#endif
+
+#ifndef IFF_LOWER_UP
+#define IFF_LOWER_UP 0x10000
+#endif
 
 #include "odhcp6c.h"
 #include "ra.h"
 
 
-static int sock = -1;
-static unsigned if_index = 0;
+static bool nocarrier = false;
+
+static int sock = -1, rtnl = -1;
+static int if_index = 0;
 static char if_name[IF_NAMESIZE] = {0};
 static volatile int rs_attempt = 0;
 static struct in6_addr lladdr = IN6ADDR_ANY_INIT;
@@ -44,11 +57,40 @@ static void ra_send_rs(int signal __attribute__((unused)));
 
 int ra_init(const char *ifname, const struct in6_addr *ifid)
 {
+	const pid_t ourpid = getpid();
 	sock = socket(AF_INET6, SOCK_RAW | SOCK_CLOEXEC, IPPROTO_ICMPV6);
+	if (sock < 0)
+		return -1;
+
 	if_index = if_nametoindex(ifname);
+	if (!if_index)
+		return -1;
+
 	strncpy(if_name, ifname, sizeof(if_name) - 1);
 	lladdr = *ifid;
 
+	rtnl = socket(AF_NETLINK, SOCK_DGRAM | SOCK_CLOEXEC, NETLINK_ROUTE);
+	if (rtnl < 0)
+		return -1;
+
+	struct sockaddr_nl rtnl_kernel = { .nl_family = AF_NETLINK };
+	if (connect(rtnl, (const struct sockaddr*)&rtnl_kernel, sizeof(rtnl_kernel)) < 0)
+		return -1;
+
+	int val = RTNLGRP_LINK;
+	setsockopt(rtnl, SOL_NETLINK, NETLINK_ADD_MEMBERSHIP, &val, sizeof(val));
+	fcntl(rtnl, F_SETOWN, ourpid);
+	fcntl(rtnl, F_SETFL, fcntl(sock, F_GETFL) | O_ASYNC);
+
+	struct {
+		struct nlmsghdr hdr;
+		struct ifinfomsg ifi;
+	} req = {
+		.hdr = {sizeof(req), RTM_GETLINK, NLM_F_REQUEST, 1, 0},
+		.ifi = {.ifi_index = if_index}
+	};
+	send(rtnl, &req, sizeof(req), 0);
+
 	// Filter ICMPv6 package types
 	struct icmp6_filter filt;
 	ICMP6_FILTER_SETBLOCKALL(&filt);
@@ -60,7 +102,7 @@ int ra_init(const char *ifname, const struct in6_addr *ifid)
 	setsockopt(sock, IPPROTO_IPV6, IPV6_ADD_MEMBERSHIP, &an, sizeof(an));
 
 	// Let the kernel compute our checksums
-	int val = 2;
+	val = 2;
 	setsockopt(sock, IPPROTO_RAW, IPV6_CHECKSUM, &val, sizeof(val));
 
 	// This is required by RFC 4861
@@ -75,7 +117,6 @@ int ra_init(const char *ifname, const struct in6_addr *ifid)
 	setsockopt(sock, SOL_SOCKET, SO_BINDTODEVICE, ifname, strlen(ifname));
 
 	// Add async-mode
-	const pid_t ourpid = getpid();
 	fcntl(sock, F_SETOWN, ourpid);
 	fcntl(sock, F_SETFL, fcntl(sock, F_GETFL) | O_ASYNC);
 
@@ -117,6 +158,69 @@ static void update_proc(const char *sect, const char *opt, uint32_t value)
 }
 
 
+bool ra_link_up(void)
+{
+	static bool firstcall = true;
+	struct {
+		struct nlmsghdr hdr;
+		struct ifinfomsg msg;
+		uint8_t pad[4000];
+	} resp;
+
+	bool ret = false;
+	ssize_t read;
+
+	do {
+		read = recv(rtnl, &resp, sizeof(resp), MSG_DONTWAIT);
+		if (read < 0 || !NLMSG_OK(&resp.hdr, (size_t)read) ||
+				resp.hdr.nlmsg_type != RTM_NEWLINK ||
+				resp.msg.ifi_index != if_index)
+			continue;
+
+		bool hascarrier = resp.msg.ifi_flags & IFF_LOWER_UP;
+		if (!firstcall && nocarrier != !hascarrier)
+			ret = true;
+
+		nocarrier = !hascarrier;
+		firstcall = false;
+	} while (read > 0);
+
+	if (ret) {
+		syslog(LOG_NOTICE, "carrier => %i event on %s", (int)!nocarrier, if_name);
+
+		rs_attempt = 0;
+		ra_send_rs(SIGALRM);
+	}
+
+	return ret;
+}
+
+static bool ra_icmpv6_valid(struct sockaddr_in6 *source, int hlim, uint8_t *data, size_t len)
+{
+	struct icmp6_hdr *hdr = (struct icmp6_hdr*)data;
+	struct icmpv6_opt *opt, *end = (struct icmpv6_opt*)&data[len];
+
+	if (hlim != 255 || len < sizeof(*hdr) || hdr->icmp6_code)
+		return false;
+
+	switch (hdr->icmp6_type) {
+	case ND_ROUTER_ADVERT:
+		if (!IN6_IS_ADDR_LINKLOCAL(&source->sin6_addr))
+			return false;
+
+		opt = (struct icmpv6_opt*)((struct nd_router_advert*)data + 1);
+		break;
+
+	default:
+		return false;
+	}
+
+	icmpv6_for_each_option(opt, opt, end)
+		;
+
+	return opt == end;
+}
+
 bool ra_process(void)
 {
 	bool found = false;
@@ -148,10 +252,8 @@ bool ra_process(void)
 				cmsg_buf, sizeof(cmsg_buf), 0};
 
 		ssize_t len = recvmsg(sock, &msg, MSG_DONTWAIT);
-		if (len < 0)
+		if (len <= 0)
 			break;
-		else if (len < (ssize_t)sizeof(*adv))
-			continue;
 
 		int hlim = 0;
 		for (struct cmsghdr *ch = CMSG_FIRSTHDR(&msg); ch != NULL;
@@ -160,7 +262,7 @@ bool ra_process(void)
 					ch->cmsg_type == IPV6_HOPLIMIT)
 				memcpy(&hlim, CMSG_DATA(ch), sizeof(hlim));
 
-		if (hlim != 255)
+		if (!ra_icmpv6_valid(&from, hlim, buf, len))
 			continue;
 
 		// Stop sending solicits
@@ -186,6 +288,10 @@ bool ra_process(void)
 		entry.preferred = entry.valid;
 		changed |= odhcp6c_update_entry(STATE_RA_ROUTE, &entry);
 
+		// Parse hoplimit
+		if (adv->nd_ra_curhoplimit)
+			update_proc("conf", "hop_limit", adv->nd_ra_curhoplimit);
+
 		// Parse ND parameters
 		if (ntohl(adv->nd_ra_reachable) <= 3600000)
 			update_proc("neigh", "base_reachable_time_ms", ntohl(adv->nd_ra_reachable));