*/
#define _GNU_SOURCE
-
+#define FD_SETSIZE 1024
#include <winsock2.h>
#include <ws2tcpip.h>
#include <sys/time.h>
*/
#define NAT_TRAV_PORT 22225
+/**
+ * Must match packet ID used by gnunet-helper-nat-client.c
+ */
+#define PACKET_ID 256
+
/**
* TTL to use for our outgoing messages.
*/
/**
* Time to live
*/
- uint8_t ttl;
+ uint8_t ttl;
/**
* Protocol
*/
- uint8_t proto;
+ uint8_t proto;
/**
* Header checksum
/**
* Source address
*/
- uint32_t src_ip;
+ uint32_t src_ip;
/**
* Destination address
*/
- uint32_t dst_ip;
+ uint32_t dst_ip;
};
/**
uint16_t crc;
};
+/**
+ * Will this binary be run in permissions testing mode?
+ */
+static boolean privilege_testing = FALSE;
+
/**
* Socket we use to receive "fake" ICMP replies.
*/
* @return the CRC 16.
*/
static uint16_t
-calc_checksum(const uint16_t *data,
- unsigned int bytes)
+calc_checksum (const uint16_t * data, unsigned int bytes)
{
uint32_t sum;
unsigned int i;
sum = 0;
- for (i=0;i<bytes/2;i++)
+ for (i = 0; i < bytes / 2; i++)
sum += data[i];
sum = (sum & 0xffff) + (sum >> 16);
- sum = htons(0xffff - sum);
+ sum = htons (0xffff - sum);
return sum;
}
* @return 1 on success
*/
static int
-inet_pton (int af,
- const char *cp,
- struct in_addr *buf)
+inet_pton (int af, const char *cp, struct in_addr *buf)
{
- buf->s_addr = inet_addr(cp);
+ buf->s_addr = inet_addr (cp);
if (buf->s_addr == INADDR_NONE)
- {
- fprintf(stderr,
- "Error %d handling address %s",
- WSAGetLastError(),
- cp);
- return 0;
- }
+ {
+ fprintf (stderr, "Error %d handling address %s", WSAGetLastError (), cp);
+ return 0;
+ }
return 1;
}
ip_pkt.vers_ihl = 0x45;
ip_pkt.tos = 0;
ip_pkt.pkt_len = htons (sizeof (packet));
- ip_pkt.id = htons (256);
+ ip_pkt.id = htons (PACKET_ID);
ip_pkt.flags_frag_offset = 0;
ip_pkt.ttl = IPDEFTTL;
ip_pkt.proto = IPPROTO_ICMP;
ip_pkt.checksum = 0;
ip_pkt.src_ip = my_ip->s_addr;
ip_pkt.dst_ip = dummy.s_addr;
- ip_pkt.checksum = htons(calc_checksum((uint16_t*)&ip_pkt,
- sizeof (struct ip_header)));
- memcpy (&packet[off],
- &ip_pkt,
- sizeof (struct ip_header));
+ ip_pkt.checksum =
+ htons (calc_checksum ((uint16_t *) & ip_pkt, sizeof (struct ip_header)));
+ memcpy (&packet[off], &ip_pkt, sizeof (struct ip_header));
off += sizeof (struct ip_header);
icmp_echo.type = ICMP_ECHO;
icmp_echo.code = 0;
icmp_echo.reserved = 0;
icmp_echo.checksum = 0;
- icmp_echo.checksum = htons(calc_checksum((uint16_t*) &icmp_echo,
- sizeof (struct icmp_echo_header)));
- memcpy (&packet[off],
- &icmp_echo,
- sizeof (struct icmp_echo_header));
+ icmp_echo.checksum =
+ htons (calc_checksum
+ ((uint16_t *) & icmp_echo, sizeof (struct icmp_echo_header)));
+ memcpy (&packet[off], &icmp_echo, sizeof (struct icmp_echo_header));
off += sizeof (struct icmp_echo_header);
memset (&dst, 0, sizeof (dst));
dst.sin_family = AF_INET;
dst.sin_addr = dummy;
- err = sendto(rawsock,
- packet, off, 0,
- (struct sockaddr*)&dst,
- sizeof(dst));
+ err =
+ sendto (rawsock, packet, off, 0, (struct sockaddr *) &dst, sizeof (dst));
if (err < 0)
- {
+ {
#if VERBOSE
- fprintf(stderr,
- "sendto failed: %s\n", strerror(errno));
+ fprintf (stderr, "sendto failed: %s\n", strerror (errno));
#endif
- }
+ }
else if (err != off)
- {
- fprintf(stderr,
- "Error: partial send of ICMP message\n");
- }
+ {
+ fprintf (stderr, "Error: partial send of ICMP message\n");
+ }
}
dst.sin_family = AF_INET;
dst.sin_addr = dummy;
dst.sin_port = htons (NAT_TRAV_PORT);
- err = sendto(udpsock,
- NULL, 0, 0,
- (struct sockaddr*)&dst,
- sizeof(dst));
+ err = sendto (udpsock, NULL, 0, 0, (struct sockaddr *) &dst, sizeof (dst));
if (err < 0)
- {
+ {
#if VERBOSE
- fprintf(stderr,
- "sendto failed: %s\n", strerror(errno));
+ fprintf (stderr, "sendto failed: %s\n", strerror (errno));
#endif
- }
+ }
else if (0 != err)
- {
- fprintf(stderr,
- "Error: partial send of ICMP message\n");
- }
+ {
+ fprintf (stderr, "Error: partial send of ICMP message\n");
+ }
}
have = read (icmpsock, buf, sizeof (buf));
if (have == -1)
- {
- fprintf (stderr,
- "Error reading raw socket: %s\n",
- strerror (errno));
- return;
- }
+ {
+ fprintf (stderr, "Error reading raw socket: %s\n", strerror (errno));
+ return;
+ }
#if VERBOSE
- fprintf (stderr,
- "Received message of %u bytes\n",
- (unsigned int) have);
+ fprintf (stderr, "Received message of %u bytes\n", (unsigned int) have);
#endif
- if (have < (ssize_t) (sizeof (struct ip_header) + sizeof (struct icmp_ttl_exceeded_header) + sizeof (struct ip_header)))
- {
- /* malformed */
- return;
- }
+ if (have <
+ (ssize_t) (sizeof (struct ip_header) +
+ sizeof (struct icmp_ttl_exceeded_header) +
+ sizeof (struct ip_header)))
+ {
+ /* malformed */
+ return;
+ }
off = 0;
- memcpy (&ip_pkt,
- &buf[off],
- sizeof (struct ip_header));
+ memcpy (&ip_pkt, &buf[off], sizeof (struct ip_header));
off += sizeof (struct ip_header);
- memcpy(&source_ip,
- &ip_pkt.src_ip,
- sizeof (source_ip));
- memcpy (&icmp_ttl,
- &buf[off],
- sizeof (struct icmp_ttl_exceeded_header));
+ memcpy (&source_ip, &ip_pkt.src_ip, sizeof (source_ip));
+ memcpy (&icmp_ttl, &buf[off], sizeof (struct icmp_ttl_exceeded_header));
off += sizeof (struct icmp_ttl_exceeded_header);
- if ( (ICMP_TIME_EXCEEDED != icmp_ttl.type) ||
- (0 != icmp_ttl.code) )
- {
- /* different type than what we want */
- return;
- }
+ if ((ICMP_TIME_EXCEEDED != icmp_ttl.type) || (0 != icmp_ttl.code))
+ {
+ /* different type than what we want */
+ return;
+ }
/* skip 2nd IP header */
- memcpy (&ip_pkt,
- &buf[off],
- sizeof (struct ip_header));
+ memcpy (&ip_pkt, &buf[off], sizeof (struct ip_header));
off += sizeof (struct ip_header);
switch (ip_pkt.proto)
+ {
+ case IPPROTO_ICMP:
+ if (have !=
+ (sizeof (struct ip_header) * 2 +
+ sizeof (struct icmp_ttl_exceeded_header) +
+ sizeof (struct icmp_echo_header)))
{
- case IPPROTO_ICMP:
- if (have != (sizeof (struct ip_header) * 2 +
- sizeof (struct icmp_ttl_exceeded_header) +
- sizeof (struct icmp_echo_header)) )
- {
- /* malformed */
- return;
- }
- /* grab ICMP ECHO content */
- memcpy (&icmp_echo,
- &buf[off],
- sizeof (struct icmp_echo_header));
- port = (uint16_t) ntohl (icmp_echo.reserved);
- break;
- case IPPROTO_UDP:
- if (have != (sizeof (struct ip_header) * 2 +
- sizeof (struct icmp_ttl_exceeded_header) +
- sizeof (struct udp_header)) )
- {
- /* malformed */
- return;
- }
- /* grab UDP content */
- memcpy (&udp_pkt,
- &buf[off],
- sizeof (struct udp_header));
- port = ntohs (udp_pkt.length);
- break;
- default:
- /* different type than what we want */
+ /* malformed */
return;
}
-
- ssize = sizeof(buf);
- WSAAddressToString((LPSOCKADDR)&source_ip,
- sizeof(source_ip),
- NULL,
- buf,
- &ssize);
+ /* grab ICMP ECHO content */
+ memcpy (&icmp_echo, &buf[off], sizeof (struct icmp_echo_header));
+ port = (uint16_t) ntohl (icmp_echo.reserved);
+ break;
+ case IPPROTO_UDP:
+ if (have !=
+ (sizeof (struct ip_header) * 2 +
+ sizeof (struct icmp_ttl_exceeded_header) + sizeof (struct udp_header)))
+ {
+ /* malformed */
+ return;
+ }
+ /* grab UDP content */
+ memcpy (&udp_pkt, &buf[off], sizeof (struct udp_header));
+ port = ntohs (udp_pkt.length);
+ break;
+ default:
+ /* different type than what we want */
+ return;
+ }
+
+ ssize = sizeof (buf);
+ WSAAddressToString ((LPSOCKADDR) & source_ip, sizeof (source_ip), NULL, buf,
+ &ssize);
if (port == 0)
- fprintf (stdout,
- "%s\n",
- buf);
+ fprintf (stdout, "%s\n", buf);
else
- fprintf (stdout,
- "%s:%u\n",
- buf,
- (unsigned int) port);
+ fprintf (stdout, "%s:%u\n", buf, (unsigned int) port);
fflush (stdout);
}
ret = socket (AF_INET, SOCK_RAW, IPPROTO_ICMP);
if (INVALID_SOCKET == ret)
- {
- fprintf (stderr,
- "Error opening RAW socket: %s\n",
- strerror (errno));
- return INVALID_SOCKET;
- }
+ {
+ fprintf (stderr, "Error opening RAW socket: %s\n", strerror (errno));
+ return INVALID_SOCKET;
+ }
return ret;
}
make_raw_socket ()
{
DWORD bOptVal = TRUE;
- int bOptLen = sizeof(bOptVal);
+ int bOptLen = sizeof (bOptVal);
rawsock = socket (AF_INET, SOCK_RAW, IPPROTO_ICMP);
if (INVALID_SOCKET == rawsock)
- {
- fprintf (stderr,
- "Error opening RAW socket: %s\n",
- strerror (errno));
- return INVALID_SOCKET;
- }
-
- if (0 != setsockopt(rawsock,
- SOL_SOCKET,
- SO_BROADCAST,
- (char*)&bOptVal, bOptLen))
- {
- fprintf(stderr,
- "Error setting SO_BROADCAST to ON: %s\n",
- strerror (errno));
- closesocket(rawsock);
- return INVALID_SOCKET;
- }
- if (0 != setsockopt(rawsock,
- IPPROTO_IP,
- IP_HDRINCL,
- (char*)&bOptVal, bOptLen))
- {
- fprintf(stderr,
- "Error setting IP_HDRINCL to ON: %s\n",
- strerror (errno));
- closesocket(rawsock);
- return INVALID_SOCKET;
- }
+ {
+ fprintf (stderr, "Error opening RAW socket: %s\n", strerror (errno));
+ return INVALID_SOCKET;
+ }
+
+ if (0 !=
+ setsockopt (rawsock, SOL_SOCKET, SO_BROADCAST, (char *) &bOptVal,
+ bOptLen))
+ {
+ fprintf (stderr, "Error setting SO_BROADCAST to ON: %s\n",
+ strerror (errno));
+ closesocket (rawsock);
+ return INVALID_SOCKET;
+ }
+ if (0 !=
+ setsockopt (rawsock, IPPROTO_IP, IP_HDRINCL, (char *) &bOptVal, bOptLen))
+ {
+ fprintf (stderr, "Error setting IP_HDRINCL to ON: %s\n", strerror (errno));
+ closesocket (rawsock);
+ return INVALID_SOCKET;
+ }
return rawsock;
}
ret = socket (AF_INET, SOCK_DGRAM, 0);
if (INVALID_SOCKET == ret)
- {
- fprintf (stderr,
- "Error opening UDP socket: %s\n",
- strerror (errno));
- return INVALID_SOCKET;
- }
+ {
+ fprintf (stderr, "Error opening UDP socket: %s\n", strerror (errno));
+ return INVALID_SOCKET;
+ }
memset (&addr, 0, sizeof (addr));
addr.sin_family = AF_INET;
addr.sin_addr = *my_ip;
addr.sin_port = htons (NAT_TRAV_PORT);
- if (0 != bind (ret,
- (struct sockaddr *)&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 */
- }
+ if (0 != bind (ret, (struct sockaddr *) &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)
+main (int argc, char *const *argv)
{
struct in_addr external;
fd_set rs;
struct timeval tv;
WSADATA wsaData;
- unsigned int alt;
+ unsigned int alt = 0;
+
+ if ( (argc > 1) && (0 != strcmp (argv[1], "-d")))
+ {
+ privilege_testing = TRUE;
+ fprintf (stderr,
+ "%s",
+ "DEBUG: Running binary in privilege testing mode.");
+ argv++;
+ argc--;
+ }
- alt = 0;
if (2 != argc)
- {
- fprintf (stderr,
- "This program must be started with our (internal NAT) IP as the only argument.\n");
- return 1;
- }
+ {
+ fprintf (stderr,
+ "This program must be started with our (internal NAT) IP as the only argument.\n");
+ return 1;
+ }
if (1 != inet_pton (AF_INET, argv[1], &external))
- {
- fprintf (stderr,
- "Error parsing IPv4 address: %s, error %s\n",
- argv[1], strerror (errno));
- return 1;
- }
+ {
+ fprintf (stderr, "Error parsing IPv4 address: %s, error %s\n", argv[1],
+ strerror (errno));
+ return 1;
+ }
if (1 != inet_pton (AF_INET, DUMMY_IP, &dummy))
- {
- fprintf (stderr,
- "Internal error converting dummy IP to binary.\n");
- return 2;
- }
+ {
+ fprintf (stderr, "Internal error converting dummy IP to binary.\n");
+ return 2;
+ }
if (WSAStartup (MAKEWORD (2, 1), &wsaData) != 0)
+ {
+ fprintf (stderr, "Failed to find Winsock 2.1 or better.\n");
+ return 2;
+ }
+ if (INVALID_SOCKET == (icmpsock = make_icmp_socket ()))
+ {
+ return 3;
+ }
+ if (INVALID_SOCKET == (make_raw_socket ()))
+ {
+ closesocket (icmpsock);
+ return 3;
+ }
+ if (INVALID_SOCKET == (udpsock = make_udp_socket (&external)))
+ {
+ closesocket (icmpsock);
+ closesocket (rawsock);
+ return 3;
+ }
+
+ while ( ! privilege_testing)
+ {
+ FD_ZERO (&rs);
+ FD_SET (icmpsock, &rs);
+ tv.tv_sec = 0;
+ tv.tv_usec = ICMP_SEND_FREQUENCY_MS * 1000;
+ if (-1 == select (icmpsock + 1, &rs, NULL, NULL, &tv))
{
- fprintf (stderr, "Failed to find Winsock 2.1 or better.\n");
- return 2;
- }
- if (INVALID_SOCKET == (icmpsock = make_icmp_socket()))
- {
- return 3;
- }
- if (INVALID_SOCKET == (make_raw_socket()))
- {
- closesocket (icmpsock);
- return 3;
- }
- if (INVALID_SOCKET == (udpsock = make_udp_socket(&external)))
- {
- closesocket (icmpsock);
- closesocket (rawsock);
- return 3;
- }
- while (1)
- {
- FD_ZERO (&rs);
- FD_SET (icmpsock, &rs);
- tv.tv_sec = 0;
- tv.tv_usec = ICMP_SEND_FREQUENCY_MS * 1000;
- if (-1 == select (icmpsock + 1, &rs, NULL, NULL, &tv))
- {
- if (errno == EINTR)
- continue;
- fprintf (stderr,
- "select failed: %s\n",
- strerror (errno));
- break;
- }
- if (FD_ISSET (icmpsock, &rs))
- process_icmp_response ();
- if (0 == (++alt % 2))
- send_icmp_echo (&external);
- else
- send_udp ();
+ if (errno == EINTR)
+ continue;
+ fprintf (stderr, "select failed: %s\n", strerror (errno));
+ break;
}
+ if (FD_ISSET (icmpsock, &rs))
+ process_icmp_response ();
+ if (0 == (++alt % 2))
+ send_icmp_echo (&external);
+ else
+ send_udp ();
+ }
/* select failed (internal error or OS out of resources) */
- closesocket(icmpsock);
- closesocket(rawsock);
- closesocket(udpsock);
+ closesocket (icmpsock);
+ closesocket (rawsock);
+ closesocket (udpsock);
WSACleanup ();
+ if (privilege_testing)
+ return 0;
return 4;
}