diff options
| -rw-r--r-- | socket.c | 25 |
1 files changed, 24 insertions, 1 deletions
@@ -1,5 +1,5 @@ /* - * Copyright (C) 2014-2015 Tobias Klauser <tklauser@distanz.ch> + * Copyright (C) 2014-2016 Tobias Klauser <tklauser@distanz.ch> * * This file is part of llmnrd. * @@ -34,6 +34,7 @@ #include "socket.h" static const int YES = 1; +static const int TTL = 255; int socket_open_ipv4(uint16_t port) { @@ -52,6 +53,17 @@ int socket_open_ipv4(uint16_t port) goto err; } + /* RFC 4795, section 2.5 recommends to set TTL to 255 for UDP */ + if (setsockopt(sock, IPPROTO_IP, IP_TTL, &TTL, sizeof(TTL)) < 0) { + log_err("Failed to set IPv4 unicast TTL socket option: %s\n", strerror(errno)); + goto err; + } + + if (setsockopt(sock, IPPROTO_IP, IP_MULTICAST_TTL, &TTL, sizeof(TTL)) < 0) { + log_err("Failed to set IPv4 multicast TTL socket option: %s\n", strerror(errno)); + goto err; + } + /* bind the socket */ memset(&sa, 0, sizeof(sa)); sa.sin_family = AF_INET; @@ -91,6 +103,17 @@ int socket_open_ipv6(uint16_t port) goto err; } + /* RFC 4795, section 2.5 recommends to set TTL to 255 for UDP */ + if (setsockopt(sock, IPPROTO_IPV6, IPV6_UNICAST_HOPS, &TTL, sizeof(TTL)) < 0) { + log_err("Failed to set IPv6 unicast hops socket option: %s\n", strerror(errno)); + goto err; + } + + if (setsockopt(sock, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &TTL, sizeof(TTL)) < 0) { + log_err("Failed to set IPv6 multicast hops socket option: %s\n", strerror(errno)); + goto err; + } + /* IPv6 only socket */ if (setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, &YES, sizeof(YES)) < 0) { log_err("Failed to set IPv6 only socket option: %s\n", strerror(errno)); |