/**
- * Copyright (C) 2012-2013 Steven Barth <steven@midlink.org>
+ * Copyright (C) 2012-2014 Steven Barth <steven@midlink.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License v2 as published by
*/
#include <fcntl.h>
+#include <ifaddrs.h>
#include <stdio.h>
#include <signal.h>
#include <string.h>
#include <net/if.h>
#include <arpa/inet.h>
#include <sys/socket.h>
+#include <sys/types.h>
#include <netinet/in.h>
#include <netinet/icmp6.h>
#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;
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);
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
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));
// Add async-mode
- const pid_t ourpid = getpid();
fcntl(sock, F_SETOWN, ourpid);
fcntl(sock, F_SETFL, fcntl(sock, F_GETFL) | O_ASYNC);
- if (IN6_IS_ADDR_UNSPECIFIED(&lladdr)) {
- // Autodetect interface-id if not specified
- FILE *fp = fopen("/proc/net/if_inet6", "r");
- if (fp) {
- char addrbuf[33], ifbuf[16];
- while (fscanf(fp, "%32s %*x %*x %*x %*x %15s", addrbuf, ifbuf) == 2) {
- if (!strcmp(ifbuf, if_name)) {
- script_unhexlify((uint8_t*)&lladdr, sizeof(lladdr), addrbuf);
- break;
- }
- }
- fclose(fp);
- }
- }
-
// Send RS
signal(SIGALRM, ra_send_rs);
ra_send_rs(SIGALRM);
}
+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;
- uint8_t buf[1500];
+ bool changed = false;
+ bool has_lladdr = !IN6_IS_ADDR_UNSPECIFIED(&lladdr);
+ 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};
+ struct odhcp6c_entry entry = {IN6ADDR_ANY_INIT, 0, 0, IN6ADDR_ANY_INIT, 0, 0, 0, 0, 0, 0};
const struct in6_addr any = IN6ADDR_ANY_INIT;
+ if (!has_lladdr) {
+ // Autodetect interface-id if not specified
+ struct ifaddrs *ifaddr, *ifa;
+
+ if (getifaddrs(&ifaddr) == 0) {
+ for (ifa = ifaddr; ifa != NULL; ifa = ifa->ifa_next) {
+ struct sockaddr_in6 *addr;
+
+ if (ifa->ifa_addr == NULL || ifa->ifa_addr->sa_family != AF_INET6)
+ continue;
+
+ addr = (struct sockaddr_in6*)ifa->ifa_addr;
+
+ if (!IN6_IS_ADDR_LINKLOCAL(&addr->sin6_addr))
+ continue;
+
+ if (!strcmp(ifa->ifa_name, if_name)) {
+ lladdr = addr->sin6_addr;
+ has_lladdr = true;
+ break;
+ }
+ }
+
+ freeifaddrs(ifaddr);
+ }
+ }
+
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);
- if (len < 0)
+ 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))
+
+ if (!has_lladdr)
+ 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 (!ra_icmpv6_valid(&from, hlim, buf, len))
continue;
// Stop sending solicits
entry.priority = pref_to_priority(0);
entry.valid = router_valid;
entry.preferred = entry.valid;
- odhcp6c_update_entry(STATE_RA_ROUTE, &entry);
+ 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)
continue;
if (entry.priority > 0)
- odhcp6c_update_entry(STATE_RA_ROUTE, &entry);
+ changed |= odhcp6c_update_entry(STATE_RA_ROUTE, &entry);
} else if (opt->type == ND_OPT_PREFIX_INFORMATION && opt->len == 4) {
struct nd_opt_prefix_info *pinfo = (struct nd_opt_prefix_info*)opt;
entry.router = any;
continue;
if (pinfo->nd_opt_pi_flags_reserved & ND_OPT_PI_FLAG_ONLINK)
- odhcp6c_update_entry_safe(STATE_RA_ROUTE, &entry, 7200);
+ changed |= odhcp6c_update_entry_safe(STATE_RA_ROUTE, &entry, 7200);
if (!(pinfo->nd_opt_pi_flags_reserved & ND_OPT_PI_FLAG_AUTO) ||
pinfo->nd_opt_pi_prefix_len != 64)
entry.target.s6_addr32[2] = lladdr.s6_addr32[2];
entry.target.s6_addr32[3] = lladdr.s6_addr32[3];
- odhcp6c_update_entry_safe(STATE_RA_PREFIX, &entry, 7200);
+ changed |= odhcp6c_update_entry_safe(STATE_RA_PREFIX, &entry, 7200);
} else if (opt->type == ND_OPT_RECURSIVE_DNS && opt->len > 2) {
entry.router = from.sin6_addr;
entry.priority = 0;
for (ssize_t i = 0; i < (opt->len - 1) / 2; ++i) {
memcpy(&entry.target, &opt->data[6 + i * sizeof(entry.target)],
sizeof(entry.target));
- odhcp6c_update_entry(STATE_RA_DNS, &entry);
+ changed |= odhcp6c_update_entry(STATE_RA_DNS, &entry);
}
}
}
if (found)
odhcp6c_expire();
- return found;
+ return found && changed;
}