diff options
| -rw-r--r-- | src/transport/gnunet-nat-server.c | 105 |
1 files changed, 103 insertions, 2 deletions
diff --git a/src/transport/gnunet-nat-server.c b/src/transport/gnunet-nat-server.c index e9cbee47cb..e3631b63f2 100644 --- a/src/transport/gnunet-nat-server.c +++ b/src/transport/gnunet-nat-server.c @@ -74,6 +74,11 @@ #define DUMMY_IP "192.0.2.86" /** + * Port for UDP + */ +#define NAT_TRAV_PORT 22225 + +/** * How often do we send our ICMP messages to receive replies? */ #define ICMP_SEND_FREQUENCY_MS 500 @@ -172,6 +177,11 @@ static int icmpsock; static int rawsock; /** + * Socket we use to send our UDP requests. + */ +static int udpsock; + +/** * Target "dummy" address. */ static struct in_addr dummy; @@ -258,7 +268,7 @@ send_icmp_echo (const struct in_addr *my_ip) "sendto failed: %s\n", strerror(errno)); #endif } - else if (err != off) + else if (err != sizeof (packet)) { fprintf(stderr, "Error: partial send of ICMP message\n"); @@ -267,6 +277,44 @@ send_icmp_echo (const struct in_addr *my_ip) /** + * Send a UDP message to the dummy IP. + * + * @param my_ip source address (our ip address) + */ +static void +send_udp (const struct in_addr *my_ip) +{ + struct sockaddr_in dst; + ssize_t err; + + memset (&dst, 0, sizeof (dst)); + dst.sin_family = AF_INET; +#if HAVE_SOCKADDR_IN_SIN_LEN + dst.sin_len = sizeof (struct sockaddr_in); +#endif + dst.sin_addr = dummy; + dst.sin_port = htons (NAT_TRAV_PORT); + err = sendto(udpsock, + NULL, 0, 0, + (struct sockaddr*)&dst, + sizeof(dst)); + if (err < 0) + { +#if VERBOSE + fprintf(stderr, + "sendto failed: %s\n", strerror(errno)); +#endif + } + else if (err != 0) + { + fprintf(stderr, + "Error: partial send of ICMP message\n"); + } +} + + + +/** * We've received an ICMP response. Process it. */ static void @@ -444,6 +492,47 @@ make_raw_socket () } +/** + * Create a UDP socket for writinging. + * + * @return -1 on error + */ +static int +make_udp_socket () +{ + int ret; + struct sockaddr_in addr; + + ret = socket (AF_INET, SOCK_DGRAM, 0); + if (-1 == ret) + { + fprintf (stderr, + "Error opening UDP socket: %s\n", + strerror (errno)); + return -1; + } + memset (&addr, 0, sizeof (addr)); + addr.sin_family = AF_INET; +#if HAVE_SOCKADDR_IN_SIN_LEN + addr.sin_len = sizeof (struct sockaddr_in); +#endif + /* addr.sin_addr zero == ours (hopefully...) */ + addr.sin_port = htons (NAT_TRAV_PORT); + + if (0 != bind (ret, + &addr, + sizeof(addr))) + { + fprintf (stderr, + "Error binding UDP socket to port %u: %s\n", + NAT_TRAV_PORT, + strerror (errno)); + /* likely problematic, but not certain, try to continue */ + } + return ret; +} + + int main (int argc, char *const *argv) @@ -452,6 +541,7 @@ main (int argc, fd_set rs; struct timeval tv; uid_t uid; + unsigned int alt; if (argc != 2) { @@ -489,6 +579,13 @@ main (int argc, strerror (errno)); /* not critical, continue anyway */ } + if (-1 == (udpsock = make_udp_socket())) + { + close (icmpsock); + close (rawsock); + return 3; + } + alt = 0; while (1) { FD_ZERO (&rs); @@ -506,11 +603,15 @@ main (int argc, } if (FD_ISSET (icmpsock, &rs)) process_icmp_response (); - send_icmp_echo (&external); + if (0 == (++alt % 2)) + send_icmp_echo (&external); + else + send_udp (&external); } /* select failed (internal error or OS out of resources) */ close (icmpsock); close (rawsock); + close (udpsock); return 4; } |