From 0131c7ed248d8a39480afd455de800c242ae5350 Mon Sep 17 00:00:00 2001 From: Steven Barth Date: Wed, 6 Nov 2013 13:04:53 +0100 Subject: [PATCH] Fix bfd ping --- CMakeLists.txt | 7 +++++- src/bfd.c | 65 ++++++++++++++++++++++++++++---------------------- src/bfd.h | 18 ++++++++++++++ src/odhcp6c.c | 15 ++++++++++++ 4 files changed, 75 insertions(+), 30 deletions(-) create mode 100644 src/bfd.h diff --git a/CMakeLists.txt b/CMakeLists.txt index 8112859..47537e9 100644 --- a/CMakeLists.txt +++ b/CMakeLists.txt @@ -11,7 +11,12 @@ if(${EXT_PREFIX_CLASS}) add_definitions(-DEXT_PREFIX_CLASS=${EXT_PREFIX_CLASS}) endif(${EXT_PREFIX_CLASS}) -add_executable(odhcp6c src/odhcp6c.c src/dhcpv6.c src/ra.c src/script.c src/md5.c) +if(${EXT_BFD_PING}) + add_definitions(-DEXT_BFD_PING) + set(BFD_SOURCE src/bfd.c) +endif(${EXT_BFD_PING}) + +add_executable(odhcp6c src/odhcp6c.c src/dhcpv6.c src/ra.c src/script.c src/md5.c ${BFD_SOURCE}) target_link_libraries(odhcp6c resolv) # Installation diff --git a/src/bfd.c b/src/bfd.c index be71361..11fade1 100644 --- a/src/bfd.c +++ b/src/bfd.c @@ -6,6 +6,7 @@ #include #include +#include #include #include #include @@ -22,7 +23,7 @@ static int bfd_failed = 0, bfd_limit = 0, bfd_interval = 0; static bool bfd_armed = false; -static void bfd_send(int signal) +static void bfd_send(int signal __attribute__((unused))) { struct { struct ip6_hdr ip6; @@ -43,6 +44,15 @@ static void bfd_send(int signal) struct odhcp6c_entry *rt = odhcp6c_get_state(STATE_RA_ROUTE, &rtlen), *crt = NULL; bool crt_found = false; + alarm(bfd_interval); + + if (bfd_armed) { + if (++bfd_failed > bfd_limit) { + raise(SIGUSR2); + return; + } + } + // Detect PD-Prefix for (size_t i = 0; i < pdlen / sizeof(*pd); ++i) if (!cpd || ((cpd->target.s6_addr[0] & 7) == 0xfc) > ((pd[i].target.s6_addr[0] & 7) == 0xfc) @@ -110,13 +120,6 @@ static void bfd_send(int signal) ping.ip6.ip6_src = cpd->target; ping.ip6.ip6_dst = cpd->target; - if (bfd_armed) { - if (bfd_failed++ > bfd_limit) { - raise(SIGUSR2); - return; - } - } - /* uint16_t sum = cksum(&ping.ip6.ip6_src, sizeof(ping.ip6.ip6_src), 0); sum = cksum(&ping.ip6.ip6_dst, sizeof(ping.ip6.ip6_dst), ~sum); @@ -130,41 +133,47 @@ static void bfd_send(int signal) struct sock_filter bpf[] = { BPF_STMT(BPF_LD | BPF_W | BPF_ABS, offsetof(struct ip6_hdr, ip6_plen)), - BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, htonl(8 << 16 | IPPROTO_ICMPV6 << 8 | 254), 0, 13), + BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, 8 << 16 | IPPROTO_ICMPV6 << 8 | 254, 0, 13), BPF_STMT(BPF_LD | BPF_W | BPF_ABS, offsetof(struct ip6_hdr, ip6_dst)), - BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, ping.ip6.ip6_dst.s6_addr32[0], 0, 11), + BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, ntohl(ping.ip6.ip6_dst.s6_addr32[0]), 0, 11), BPF_STMT(BPF_LD | BPF_W | BPF_ABS, offsetof(struct ip6_hdr, ip6_dst) + 4), - BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, ping.ip6.ip6_dst.s6_addr32[1], 0, 9), + BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, ntohl(ping.ip6.ip6_dst.s6_addr32[1]), 0, 9), BPF_STMT(BPF_LD | BPF_W | BPF_ABS, offsetof(struct ip6_hdr, ip6_dst) + 8), - BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, ping.ip6.ip6_dst.s6_addr32[2], 0, 7), + BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, ntohl(ping.ip6.ip6_dst.s6_addr32[2]), 0, 7), BPF_STMT(BPF_LD | BPF_W | BPF_ABS, offsetof(struct ip6_hdr, ip6_dst) + 12), - BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, ping.ip6.ip6_dst.s6_addr32[3], 0, 5), + BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, ntohl(ping.ip6.ip6_dst.s6_addr32[3]), 0, 5), BPF_STMT(BPF_LD | BPF_W | BPF_ABS, sizeof(struct ip6_hdr) + offsetof(struct icmp6_hdr, icmp6_type)), - BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, htonl(ICMP6_ECHO_REQUEST << 24), 0, 3), + BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, ICMP6_ECHO_REQUEST << 24, 0, 3), BPF_STMT(BPF_LD | BPF_W | BPF_ABS, sizeof(struct ip6_hdr) + offsetof(struct icmp6_hdr, icmp6_data32)), - BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, ping.icmp6.icmp6_data32[0], 0, 1), + BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, ntohl(ping.icmp6.icmp6_data32[0]), 0, 1), BPF_STMT(BPF_RET | BPF_K, 0xffffffff), BPF_STMT(BPF_RET | BPF_K, 0), }; struct sock_fprog bpf_prog = {sizeof(bpf) / sizeof(*bpf), bpf}; + + if (sock < 0) { + sock = socket(AF_PACKET, SOCK_DGRAM | SOCK_CLOEXEC, htons(ETH_P_IPV6)); + bind(sock, (struct sockaddr*)&dest, sizeof(dest)); + + fcntl(sock, F_SETOWN, getpid()); + fcntl(sock, F_SETFL, fcntl(sock, F_GETFL) | O_ASYNC); + } + setsockopt(sock, SOL_SOCKET, SO_DETACH_FILTER, &bpf_prog, sizeof(bpf_prog)); if (setsockopt(sock, SOL_SOCKET, SO_ATTACH_FILTER, &bpf_prog, sizeof(bpf_prog))) { close(sock); + sock = -1; return; } + uint8_t dummy[8]; + while (recv(sock, dummy, sizeof(dummy), MSG_DONTWAIT | MSG_TRUNC) > 0); - if (!signal) { - bind(sock, (struct sockaddr*)&dest, sizeof(dest)); - uint8_t dummy[8]; - while (recv(sock, dummy, sizeof(dummy), MSG_DONTWAIT | MSG_TRUNC) > 0); - } sendto(sock, &ping, sizeof(ping), MSG_DONTWAIT, (struct sockaddr*)&dest, sizeof(dest)); - alarm(bfd_interval); } @@ -178,9 +187,9 @@ void bfd_receive(void) } -int bfd_start(int ifindex, int limit, int interval) +int bfd_start(const char *ifname, int limit, int interval) { - if_index = ifindex; + if_index = if_nametoindex(ifname); bfd_armed = false; bfd_failed = 0; bfd_limit = limit; @@ -193,13 +202,8 @@ int bfd_start(int ifindex, int limit, int interval) struct sockaddr_nl rtnl_kernel = { .nl_family = AF_NETLINK }; connect(rtnl, (const struct sockaddr*)&rtnl_kernel, sizeof(rtnl_kernel)); - sock = socket(AF_PACKET, SOCK_DGRAM | SOCK_CLOEXEC, htons(ETH_P_IPV6)); - bfd_send(0); - - fcntl(sock, F_SETOWN, getpid()); - fcntl(sock, F_SETFL, fcntl(sock, F_GETFL) | O_ASYNC); - signal(SIGALRM, bfd_send); + alarm(5); return 0; } @@ -209,6 +213,9 @@ void bfd_stop(void) alarm(0); close(sock); close(rtnl); + + sock = -1; + rtnl = -1; } /* diff --git a/src/bfd.h b/src/bfd.h new file mode 100644 index 0000000..0d3616a --- /dev/null +++ b/src/bfd.h @@ -0,0 +1,18 @@ +/** + * Copyright (C) 2012-2013 Steven Barth + * + * 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 + * the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + */ +#pragma once + +int bfd_start(const char *ifname, int limit, int interval); +void bfd_receive(void); +void bfd_stop(void); diff --git a/src/odhcp6c.c b/src/odhcp6c.c index 1f75c50..2c5bfad 100644 --- a/src/odhcp6c.c +++ b/src/odhcp6c.c @@ -32,6 +32,10 @@ #include "odhcp6c.h" #include "ra.h" +#ifdef EXT_BFD_PING +#include "bfd.h" +#endif + static void sighandler(int signal); static int usage(void); @@ -262,6 +266,9 @@ int main(_unused int argc, char* const argv[]) script_call("bound"); bound = true; syslog(LOG_NOTICE, "entering stateful-mode on %s", ifname); +#ifdef EXT_BFD_PING + bfd_start(ifname, 3, 10); +#endif while (do_signal == 0 || do_signal == SIGUSR1) { // Renew Cycle @@ -311,6 +318,10 @@ int main(_unused int argc, char* const argv[]) script_call("rebound"); } +#ifdef EXT_BFD_PING + bfd_stop(); +#endif + size_t ia_pd_len, ia_na_len, server_id_len; odhcp6c_get_state(STATE_IA_PD, &ia_pd_len); @@ -398,6 +409,10 @@ bool odhcp6c_signal_process(void) script_call("ra-updated"); // Immediate process urgent events else if (ra_updated && !bound && allow_slaac_only > 0) script_delay_call("ra-updated", allow_slaac_only); + +#ifdef EXT_BFD_PING + bfd_receive(); +#endif } return do_signal != 0; -- 2.25.1