/**
- * 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 <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;
+struct {
+ struct icmp6_hdr hdr;
+ struct icmpv6_opt lladdr;
+} rs = {
+ .hdr = {ND_ROUTER_SOLICIT, 0, 0, {{0}}},
+ .lladdr = {ND_OPT_SOURCE_LINKADDR, 1, {0}},
+};
+
+
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);
+ ra_link_up();
+
// 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
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);
static void ra_send_rs(int signal __attribute__((unused)))
{
- const struct icmp6_hdr rs = {ND_ROUTER_SOLICIT, 0, 0, {{0}}};
const struct sockaddr_in6 dest = {AF_INET6, 0, 0, ALL_IPV6_ROUTERS, if_index};
- sendto(sock, &rs, sizeof(rs), MSG_DONTWAIT, (struct sockaddr*)&dest, sizeof(dest));
+ const struct icmpv6_opt llnull = {ND_OPT_SOURCE_LINKADDR, 1, {0}};
+ size_t len;
+
+ if ((rs_attempt % 2 == 0) && memcmp(&rs.lladdr, &llnull, sizeof(llnull)))
+ len = sizeof(rs);
+ else
+ len = sizeof(struct icmp6_hdr);
+
+ sendto(sock, &rs, len, MSG_DONTWAIT, (struct sockaddr*)&dest, sizeof(dest));
if (++rs_attempt <= 3)
alarm(4);
static int16_t pref_to_priority(uint8_t flags)
{
flags = (flags >> 3) & 0x03;
- return (flags == 0x0) ? 1024 : (flags == 0x1) ? 512 :
- (flags == 0x3) ? 2048 : -1;
+ return (flags == 0x0) ? 512 : (flags == 0x1) ? 384 :
+ (flags == 0x3) ? 640 : -1;
}
}
+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;
+
+ ssize_t alen = NLMSG_PAYLOAD(&resp.hdr, sizeof(resp.msg));
+ for (struct rtattr *rta = (struct rtattr*)(resp.pad);
+ RTA_OK(rta, alen); rta = RTA_NEXT(rta, alen)) {
+ if (rta->rta_type == IFLA_ADDRESS &&
+ RTA_PAYLOAD(rta) >= sizeof(rs.lladdr.data))
+ memcpy(rs.lladdr.data, RTA_DATA(rta), sizeof(rs.lladdr.data));
+ }
+
+ 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;
bool changed = false;
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, 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 (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);
- }
+ struct sockaddr_in6 addr = {AF_INET6, 0, 0, ALL_IPV6_ROUTERS, if_index};
+ socklen_t alen = sizeof(addr);
+ int sock = socket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6);
+
+ if (!connect(sock, (struct sockaddr*)&addr, sizeof(addr)) &&
+ !getsockname(sock, (struct sockaddr*)&addr, &alen))
+ lladdr = addr.sin6_addr;
+
+ close(sock);
}
while (true) {
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))
+
+ if (IN6_IS_ADDR_UNSPECIFIED(&lladdr))
continue;
int hlim = 0;
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
entry.priority = pref_to_priority(0);
entry.valid = router_valid;
entry.preferred = entry.valid;
- changed |= odhcp6c_update_entry(STATE_RA_ROUTE, &entry);
+ changed |= odhcp6c_update_entry(STATE_RA_ROUTE, &entry, 0, true);
+
+ // 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));
+ uint32_t reachable = ntohl(adv->nd_ra_reachable);
+ if (reachable > 0 && reachable <= 3600000)
+ update_proc("neigh", "base_reachable_time_ms", reachable);
- if (ntohl(adv->nd_ra_retransmit) <= 60000)
- update_proc("neigh", "retrans_time_ms", ntohl(adv->nd_ra_retransmit));
+ uint32_t retransmit = ntohl(adv->nd_ra_retransmit);
+ if (retransmit > 0 && retransmit <= 60000)
+ update_proc("neigh", "retrans_time_ms", retransmit);
// Evaluate options
continue;
if (entry.priority > 0)
- changed |= odhcp6c_update_entry(STATE_RA_ROUTE, &entry);
+ changed |= odhcp6c_update_entry(STATE_RA_ROUTE, &entry, 0, true);
} 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)
- changed |= odhcp6c_update_entry_safe(STATE_RA_ROUTE, &entry, 7200);
+ changed |= odhcp6c_update_entry(STATE_RA_ROUTE, &entry, 7200, true);
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];
- changed |= odhcp6c_update_entry_safe(STATE_RA_PREFIX, &entry, 7200);
+ changed |= odhcp6c_update_entry(STATE_RA_PREFIX, &entry, 7200, true);
} 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));
- changed |= odhcp6c_update_entry(STATE_RA_DNS, &entry);
+ changed |= odhcp6c_update_entry(STATE_RA_DNS, &entry, 0, true);
}
}
}