From 6373af63310f32e1408a81f4e4e069a5f0d3e59e Mon Sep 17 00:00:00 2001 From: Steven Barth Date: Wed, 8 Oct 2014 11:57:07 +0200 Subject: Ensure signal-safety of signal handlers --- src/ra.c | 39 +++++++++++++++++++++++---------------- 1 file changed, 23 insertions(+), 16 deletions(-) (limited to 'src/ra.c') diff --git a/src/ra.c b/src/ra.c index baaee9b..9c5eb22 100644 --- a/src/ra.c +++ b/src/ra.c @@ -26,7 +26,6 @@ #include #include #include -#include #include #include @@ -56,6 +55,15 @@ 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) @@ -93,6 +101,7 @@ int ra_init(const char *ifname, const struct in6_addr *ifid) .ifi = {.ifi_index = if_index} }; send(rtnl, &req, sizeof(req), 0); + ra_link_up(); // Filter ICMPv6 package types struct icmp6_filter filt; @@ -133,22 +142,12 @@ int ra_init(const char *ifname, const struct in6_addr *ifid) static void ra_send_rs(int signal __attribute__((unused))) { - struct { - struct icmp6_hdr hdr; - struct icmpv6_opt lladdr; - } rs = { - .hdr = {ND_ROUTER_SOLICIT, 0, 0, {{0}}}, - .lladdr = {ND_OPT_SOURCE_LINKADDR, 1, {0}}, - }; const struct sockaddr_in6 dest = {AF_INET6, 0, 0, ALL_IPV6_ROUTERS, if_index}; - size_t len = sizeof(rs); - - struct ifreq ifr; - memset(&ifr, 0, sizeof(ifr)); - strncpy(ifr.ifr_name, if_name, sizeof(ifr.ifr_name)); - if ((rs_attempt % 2 == 0) && !ioctl(sock, SIOCGIFHWADDR, &ifr) - && memcmp(rs.lladdr.data, ifr.ifr_hwaddr.sa_data, 6)) - memcpy(rs.lladdr.data, ifr.ifr_hwaddr.sa_data, 6); + 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); @@ -197,6 +196,14 @@ bool ra_link_up(void) 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; -- cgit v1.2.1