diff options
Diffstat (limited to 'util.c')
| -rw-r--r-- | util.c | 25 |
1 files changed, 25 insertions, 0 deletions
@@ -137,6 +137,28 @@ int connectport(int type, char *host, char *port) { } #endif +/* Disable the "Don't Fragment" bit for UDP sockets. It is set by default, which may cause an "oversized" + RADIUS packet to be discarded on first attempt (due to Path MTU discovery). +*/ + +void disable_DF_bit(int socket, struct addrinfo *res) { + if ((res->ai_family == AF_INET) && (res->ai_socktype == SOCK_DGRAM)) { +#if defined(IP_MTU_DISCOVER) && defined(IP_PMTUDISC_DONT) + /* + * Turn off Path MTU discovery on IPv4/UDP sockets, Linux variant. + */ + int r, action; + debug(DBG_INFO, "disable_DF_bit: disabling DF bit (Linux variant)"); + action = IP_PMTUDISC_DONT; + r = setsockopt(socket, IPPROTO_IP, IP_MTU_DISCOVER, &action, sizeof(action)); + if (r == -1) + debug(DBG_WARN, "Failed to set IP_MTU_DISCOVER"); +#else + debug(DBG_INFO, "Non-Linux platform, unable to unset DF bit for UDP. You should check with tcpdump whether radsecproxy will send its UDP packets with DF bit set!"); +#endif + } +} + int bindtoaddr(struct addrinfo *addrinfo, int family, int reuse, int v6only) { int s, on = 1; struct addrinfo *res; @@ -149,6 +171,9 @@ int bindtoaddr(struct addrinfo *addrinfo, int family, int reuse, int v6only) { debug(DBG_WARN, "bindtoaddr: socket failed"); continue; } + + disable_DF_bit(s,res); + if (reuse) setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)); #ifdef IPV6_V6ONLY |