#include "ra.h"
-static int sock = -1, rtnl_sock = -1;
+static int sock = -1;
static unsigned if_index = 0;
static char if_name[IF_NAMESIZE] = {0};
static volatile int rs_attempt = 0;
val = 255;
setsockopt(sock, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &val, sizeof(val));
+ // Receive multicast hops
+ val = 1;
+ setsockopt(sock, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &val, sizeof(val));
+
// Bind to one device
setsockopt(sock, SOL_SOCKET, SO_BINDTODEVICE, ifname, strlen(ifname));
}
}
- // Open rtnetlink socket
- rtnl_sock = socket(AF_NETLINK, SOCK_RAW | SOCK_CLOEXEC, NETLINK_ROUTE);
- struct sockaddr_nl rtnl_kernel = { .nl_family = AF_NETLINK };
- if (connect(rtnl_sock, (struct sockaddr*)&rtnl_kernel, sizeof(rtnl_kernel)))
- return -1;
- uint32_t group = RTNLGRP_IPV6_IFADDR;
- setsockopt(rtnl_sock, SOL_NETLINK, NETLINK_ADD_MEMBERSHIP, &group, sizeof(group));
-
- // Add async-mode
- fcntl(rtnl_sock, F_SETOWN, ourpid);
- fcntl(rtnl_sock, F_SETFL, fcntl(rtnl_sock, F_GETFL) | O_ASYNC);
-
// Send RS
signal(SIGALRM, ra_send_rs);
ra_send_rs(SIGALRM);
}
-static bool ra_deduplicate(const struct in6_addr *any, uint8_t length)
-{
- struct odhcp6c_entry entry = {IN6ADDR_ANY_INIT, length, 0, *any, 0, 0, 0};
- struct odhcp6c_entry *x = odhcp6c_find_entry(STATE_RA_PREFIX, &entry);
- if (x && IN6_ARE_ADDR_EQUAL(&x->target, any)) {
- odhcp6c_random(&x->target.s6_addr32[2], 2 * sizeof(uint32_t));
- } else if (odhcp6c_find_entry(STATE_IA_NA, &entry)) {
- dhcpv6_request(DHCPV6_MSG_DECLINE);
- raise(SIGUSR2);
- }
-
- return !!x;
-}
-
-
-bool ra_rtnl_process(void)
-{
- bool found = false;
- uint32_t elapsed = odhcp6c_elapsed();
- uint8_t buf[8192];
- while (true) {
- ssize_t len = recv(rtnl_sock, buf, sizeof(buf), MSG_DONTWAIT);
- if (len < 0)
- break;
-
- if (elapsed > 10)
- continue;
-
- for (struct nlmsghdr *nh = (struct nlmsghdr*)buf; NLMSG_OK(nh, (size_t)len);
- nh = NLMSG_NEXT(nh, len)) {
- struct ifaddrmsg *ifa = NLMSG_DATA(nh);
- struct in6_addr *addr = NULL;
- if (NLMSG_PAYLOAD(nh, 0) < sizeof(*ifa) || ifa->ifa_index != if_index ||
- (nh->nlmsg_type == RTM_NEWADDR && !(ifa->ifa_flags & IFA_F_DADFAILED)) ||
- (nh->nlmsg_type == RTM_DELADDR && !(ifa->ifa_flags & IFA_F_TENTATIVE)) ||
- (nh->nlmsg_type != RTM_NEWADDR && nh->nlmsg_type != RTM_DELADDR))
- continue;
-
- ssize_t alen = NLMSG_PAYLOAD(nh, sizeof(*ifa));
- for (struct rtattr *rta = (struct rtattr*)&ifa[1]; RTA_OK(rta, alen);
- rta = RTA_NEXT(rta, alen))
- if (rta->rta_type == IFA_ADDRESS && RTA_PAYLOAD(rta) >= sizeof(*addr))
- addr = RTA_DATA(rta);
-
- if (addr) {
- char ipbuf[INET6_ADDRSTRLEN];
- inet_ntop(AF_INET6, addr, ipbuf, sizeof(ipbuf));
- syslog(LOG_WARNING, "duplicate address detected: %s (code: %u:%x)",
- ipbuf, (unsigned)nh->nlmsg_type, (unsigned)ifa->ifa_flags);
- found |= ra_deduplicate(addr, ifa->ifa_prefixlen);
- }
- }
- }
- return found;
-}
-
-
bool ra_process(void)
{
bool found = false;
- uint8_t buf[1500];
+ uint8_t buf[1500], cmsg_buf[128];
struct nd_router_advert *adv = (struct nd_router_advert*)buf;
struct odhcp6c_entry entry = {IN6ADDR_ANY_INIT, 0, 0, IN6ADDR_ANY_INIT, 0, 0, 0};
const struct in6_addr any = IN6ADDR_ANY_INIT;
while (true) {
struct sockaddr_in6 from;
- socklen_t from_len = sizeof(from);
- ssize_t len = recvfrom(sock, buf, sizeof(buf), MSG_DONTWAIT, &from, &from_len);
+ struct iovec iov = {buf, sizeof(buf)};
+ struct msghdr msg = {&from, sizeof(from), &iov, 1,
+ cmsg_buf, sizeof(cmsg_buf), 0};
+
+ ssize_t len = recvmsg(sock, &msg, MSG_DONTWAIT);
if (len < 0)
break;
else if (len < (ssize_t)sizeof(*adv))
continue;
+ int hlim = 0;
+ for (struct cmsghdr *ch = CMSG_FIRSTHDR(&msg); ch != NULL;
+ ch = CMSG_NXTHDR(&msg, ch))
+ if (ch->cmsg_level == IPPROTO_IPV6 &&
+ ch->cmsg_type == IPV6_HOPLIMIT)
+ memcpy(&hlim, CMSG_DATA(ch), sizeof(hlim));
+
+ if (hlim != 255)
+ continue;
+
// Stop sending solicits
if (rs_attempt > 0) {
alarm(0);