* - Nathan Evans
*/
#define _GNU_SOURCE
-#ifdef WIN32
+
#include <winsock2.h>
-#else
-#include <sys/types.h>
-#include <sys/socket.h>
-#include <arpa/inet.h>
-#include <sys/select.h>
-#include <netinet/ip.h>
-#include <netinet/ip_icmp.h>
-#include <netinet/in.h>
-#endif
+#include <ws2tcpip.h>
#include <sys/time.h>
#include <sys/types.h>
#include <unistd.h>
#include <time.h>
-#ifdef WIN32
-typedef unsigned int uid_t;
-typedef SOCKET Socket;
-typedef unsigned short ushort;
#define ICMP_ECHO 8
-#define IPDEFTTL 64 /* default ttl, from RFC 1340 */
-#define ICMP_TIME_EXCEEDED 11 /* Time Exceeded */
-#define IP_HDRINCL 3 /* int; Header is included with data. */
-#else
-typedef int Socket;
-#endif
+#define IPDEFTTL 64
+#define ICMP_TIME_EXCEEDED 11
/**
* Must match IP given in the server.
#define NAT_TRAV_PORT 22225
-struct ip_packet
+/**
+ * IPv4 header.
+ */
+struct ip_header
{
+
+ /**
+ * Version (4 bits) + Internet header length (4 bits)
+ */
uint8_t vers_ihl;
+
+ /**
+ * Type of service
+ */
uint8_t tos;
+
+ /**
+ * Total length
+ */
uint16_t pkt_len;
+
+ /**
+ * Identification
+ */
uint16_t id;
+
+ /**
+ * Flags (3 bits) + Fragment offset (13 bits)
+ */
uint16_t flags_frag_offset;
+
+ /**
+ * Time to live
+ */
uint8_t ttl;
+
+ /**
+ * Protocol
+ */
uint8_t proto;
+
+ /**
+ * Header checksum
+ */
uint16_t checksum;
+
+ /**
+ * Source address
+ */
uint32_t src_ip;
+
+ /**
+ * Destination address
+ */
uint32_t dst_ip;
};
-struct icmp_packet
+
+/**
+ * Format of ICMP packet.
+ */
+struct icmp_ttl_exceeded_header
{
uint8_t type;
+
uint8_t code;
+
uint16_t checksum;
- uint32_t reserved;
+ uint32_t unused;
+
+ /* followed by original payload */
};
-struct icmp_echo_packet
+struct icmp_echo_header
{
uint8_t type;
+
uint8_t code;
+
uint16_t checksum;
+
uint32_t reserved;
- uint32_t data;
};
-struct udp_packet
+/**
+ * Beginning of UDP packet.
+ */
+struct udp_header
{
uint16_t src_port;
uint16_t dst_port;
- uint32_t length;
+ uint16_t length;
+
+ uint16_t crc;
};
-static Socket rawsock;
+/**
+ * Socket we use to send our ICMP packets.
+ */
+static SOCKET rawsock;
+
+/**
+ * Target "dummy" address.
+ */
static struct in_addr dummy;
-
-static uint32_t port;
-#if WIN32
/**
+ * Port we are listening on (communicated to the server).
+ */
+static uint16_t port;
+
+
+
+/**
+ * Convert IPv4 address from text to binary form.
+ *
* @param af address family
* @param cp the address to print
* @param buf where to write the address result
+ * @return 1 on success
*/
-static int inet_pton (int af, char *cp, struct in_addr *buf)
+static int
+inet_pton (int af,
+ const char *cp,
+ struct in_addr *buf)
{
- //ret = WSAStringToAddress (cp, af, NULL, (LPSOCKADDR)buf, &ssize);
buf->s_addr = inet_addr(cp);
if (buf->s_addr == INADDR_NONE)
{
- fprintf(stderr, "Error %d handling address %s", WSAGetLastError(), cp);
+ fprintf(stderr,
+ "Error %d handling address %s",
+ WSAGetLastError(),
+ cp);
return 0;
}
- else
- return 1;
+ return 1;
}
-#endif
-static uint16_t
-calc_checksum(const uint16_t *data,
+
+/**
+ * CRC-16 for IP/ICMP headers.
+ *
+ * @param data what to calculate the CRC over
+ * @param bytes number of bytes in data (must be multiple of 2)
+ * @return the CRC 16.
+ */
+static uint16_t
+calc_checksum(const uint16_t *data,
unsigned int bytes)
{
uint32_t sum;
unsigned int i;
sum = 0;
- for (i=0;i<bytes/2;i++)
- sum += data[i];
+ for (i=0;i<bytes/2;i++)
+ sum += data[i];
sum = (sum & 0xffff) + (sum >> 16);
sum = htons(0xffff - sum);
return sum;
}
-static void
-make_echo (const struct in_addr *src_ip,
- struct icmp_echo_packet *echo, uint32_t num)
-{
- memset(echo, 0, sizeof(struct icmp_echo_packet));
- echo->type = ICMP_ECHO;
- echo->code = 0;
- echo->reserved = 0;
- echo->checksum = 0;
- echo->data = htons(num);
- echo->checksum = htons(calc_checksum((uint16_t*)echo,
- sizeof (struct icmp_echo_packet)));
-}
-
-
/**
* Send an ICMP message to the target.
*
send_icmp_udp (const struct in_addr *my_ip,
const struct in_addr *other)
{
- struct ip_packet ip_pkt;
- struct icmp_packet icmp_pkt;
- struct udp_packet udp_pkt;
-
+ char packet[sizeof(struct ip_header) * 2 +
+ sizeof(struct icmp_ttl_exceeded_header) +
+ sizeof(struct udp_header)];
+ struct ip_header ip_pkt;
+ struct icmp_ttl_exceeded_header icmp_pkt;
+ struct udp_header udp_pkt;
struct sockaddr_in dst;
- char packet[sizeof(ip_pkt) * 2 + sizeof(icmp_pkt) * 2 + sizeof(uint32_t)];
-
size_t off;
int err;
/* ip header: send to (known) ip address */
off = 0;
- memset(&ip_pkt, 0, sizeof(ip_pkt));
ip_pkt.vers_ihl = 0x45;
ip_pkt.tos = 0;
ip_pkt.pkt_len = htons(sizeof (packet));
ip_pkt.checksum = 0;
ip_pkt.src_ip = my_ip->s_addr;
ip_pkt.dst_ip = other->s_addr;
- ip_pkt.checksum = htons(calc_checksum((uint16_t*)&ip_pkt, sizeof (ip_pkt)));
- memcpy(&packet[off], &ip_pkt, sizeof(ip_pkt));
- off += sizeof(ip_pkt);
-
- /* ip header of the presumably 'lost' udp packet */
- ip_pkt.vers_ihl = 0x45;
- ip_pkt.tos = 0;
- ip_pkt.pkt_len = (sizeof (struct ip_packet) + sizeof (struct icmp_echo_packet));
-
- icmp_pkt.type = 11; /* TTL exceeded */
+ 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_pkt.type = ICMP_TIME_EXCEEDED;
icmp_pkt.code = 0;
icmp_pkt.checksum = 0;
- icmp_pkt.reserved = 0;
- memcpy(&packet[off], &icmp_pkt, sizeof(icmp_pkt));
- off += sizeof(icmp_pkt);
+ icmp_pkt.unused = 0;
+ memcpy(&packet[off],
+ &icmp_pkt,
+ sizeof(struct icmp_ttl_exceeded_header));
+ off += sizeof(struct icmp_ttl_exceeded_header);
- /* build inner IP header */
- memset(&ip_pkt, 0, sizeof(ip_pkt));
+ /* ip header of the presumably 'lost' udp packet */
ip_pkt.vers_ihl = 0x45;
ip_pkt.tos = 0;
- ip_pkt.pkt_len = htons(sizeof (ip_pkt) + sizeof(udp_pkt));
+ ip_pkt.pkt_len = htons(sizeof (struct ip_header) +
+ sizeof (struct udp_header));
ip_pkt.id = htons(0);
ip_pkt.flags_frag_offset = 0;
ip_pkt.ttl = 128;
ip_pkt.checksum = 0;
ip_pkt.src_ip = other->s_addr;
ip_pkt.dst_ip = dummy.s_addr;
- ip_pkt.checksum = htons(calc_checksum((uint16_t*)&ip_pkt, sizeof (ip_pkt)));
- memcpy(&packet[off], &ip_pkt, sizeof(ip_pkt));
- off += sizeof(ip_pkt);
+ 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);
/* build UDP header */
- udp_pkt.src_port = htons(NAT_TRAV_PORT); /* FIXME: does this port matter? */
+ udp_pkt.src_port = htons(NAT_TRAV_PORT);
udp_pkt.dst_port = htons(NAT_TRAV_PORT);
-
- memset(&udp_pkt.length, 0, sizeof(uint32_t));
- udp_pkt.length = htonl(port);
- memcpy(&packet[off], &udp_pkt, sizeof(udp_pkt));
- off += sizeof(udp_pkt);
-
- /* set ICMP checksum */
- icmp_pkt.checksum = htons(calc_checksum((uint16_t*)&packet[sizeof(ip_pkt)],
- sizeof (icmp_pkt) + sizeof(ip_pkt) + sizeof(udp_pkt)));
- memcpy (&packet[sizeof(ip_pkt)], &icmp_pkt, sizeof (icmp_pkt));
-
+ udp_pkt.length = htons (port);
+ udp_pkt.crc = 0;
+ memcpy(&packet[off],
+ &udp_pkt,
+ sizeof(struct udp_header));
+ off += sizeof(struct udp_header);
+
+ /* no go back to calculate ICMP packet checksum */
+ icmp_pkt.checksum = htons(calc_checksum((uint16_t*)&packet[off],
+ sizeof (struct icmp_ttl_exceeded_header) +
+ sizeof (struct ip_header) +
+ sizeof (struct udp_header)));
+ memcpy (&packet[sizeof (struct ip_header)],
+ &icmp_pkt,
+ sizeof (struct icmp_ttl_exceeded_header));
memset (&dst, 0, sizeof (dst));
dst.sin_family = AF_INET;
dst.sin_addr = *other;
err = sendto(rawsock,
packet,
- off, 0,
+ sizeof (packet), 0,
(struct sockaddr*)&dst,
sizeof(dst));
-
if (err < 0)
{
fprintf(stderr,
"sendto failed: %s\n", strerror(errno));
}
- else if (err != off)
+ else if (sizeof (packet) != (size_t) err)
{
fprintf(stderr,
"Error: partial send of ICMP message\n");
send_icmp (const struct in_addr *my_ip,
const struct in_addr *other)
{
- struct ip_packet ip_pkt;
- struct icmp_packet *icmp_pkt;
- struct icmp_echo_packet icmp_echo;
+ struct ip_header ip_pkt;
+ struct icmp_ttl_exceeded_header icmp_ttl;
+ struct icmp_echo_header icmp_echo;
struct sockaddr_in dst;
- char packet[sizeof (struct ip_packet)*2 + sizeof (struct icmp_packet) + sizeof(struct icmp_echo_packet)];
-
+ char packet[sizeof (struct ip_header) * 2 +
+ sizeof (struct icmp_ttl_exceeded_header) +
+ sizeof(struct icmp_echo_header)];
size_t off;
int err;
/* ip header: send to (known) ip address */
off = 0;
- memset(&ip_pkt, 0, sizeof(ip_pkt));
ip_pkt.vers_ihl = 0x45;
ip_pkt.tos = 0;
- ip_pkt.pkt_len = sizeof (packet); /* huh? */
- ip_pkt.id = 1;
+ ip_pkt.pkt_len = htons (sizeof (packet));
+ ip_pkt.id = htons(256);
ip_pkt.flags_frag_offset = 0;
ip_pkt.ttl = IPDEFTTL;
ip_pkt.proto = IPPROTO_ICMP;
- ip_pkt.checksum = 0;
+ ip_pkt.checksum = 0;
ip_pkt.src_ip = my_ip->s_addr;
ip_pkt.dst_ip = other->s_addr;
- ip_pkt.checksum = htons(calc_checksum((uint16_t*)&ip_pkt, sizeof (struct ip_packet)));
- memcpy (packet, &ip_pkt, sizeof (struct ip_packet));
+ 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 (ip_pkt);
- /* icmp reply: time exceeded */
- icmp_pkt = (struct icmp_packet*) &packet[off];
- memset(icmp_pkt, 0, sizeof(struct icmp_packet));
- icmp_pkt->type = ICMP_TIME_EXCEEDED;
- icmp_pkt->code = 0;
- icmp_pkt->reserved = 0;
- icmp_pkt->checksum = 0;
- off += sizeof (struct icmp_packet);
+ /* icmp reply: time exceeded */
+ icmp_ttl.type = ICMP_TIME_EXCEEDED;
+ icmp_ttl.code = 0;
+ icmp_ttl.checksum = 0;
+ icmp_ttl.unused = 0;
+ memcpy (&packet[off],
+ &icmp_ttl,
+ sizeof (struct icmp_ttl_exceeded_header));
+ off += sizeof (struct icmp_ttl_exceeded_header);
/* ip header of the presumably 'lost' udp packet */
ip_pkt.vers_ihl = 0x45;
ip_pkt.tos = 0;
- ip_pkt.pkt_len = (sizeof (struct ip_packet) + sizeof (struct icmp_echo_packet));
-
- ip_pkt.id = 1;
+ ip_pkt.pkt_len = htons(sizeof (struct ip_header) + sizeof (struct icmp_echo_header));
+ ip_pkt.id = htons (256);
ip_pkt.flags_frag_offset = 0;
ip_pkt.ttl = 1; /* real TTL would be 1 on a time exceeded packet */
ip_pkt.proto = IPPROTO_ICMP;
ip_pkt.src_ip = other->s_addr;
ip_pkt.dst_ip = dummy.s_addr;
ip_pkt.checksum = 0;
- ip_pkt.checksum = htons(calc_checksum((uint16_t*)&ip_pkt, sizeof (struct ip_packet)));
- memcpy (&packet[off], &ip_pkt, sizeof (struct ip_packet));
- off += sizeof (struct ip_packet);
-
- make_echo (other, &icmp_echo, port);
- memcpy (&packet[off], &icmp_echo, sizeof(struct icmp_echo_packet));
- off += sizeof (struct icmp_echo_packet);
-
- icmp_pkt->checksum = htons(calc_checksum((uint16_t*)icmp_pkt,
- sizeof (struct icmp_packet) + sizeof(struct ip_packet) + sizeof(struct icmp_echo_packet)));
+ 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 = htonl(port);
+ 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));
+
+ /* no go back to calculate ICMP packet checksum */
+ off = sizeof (struct ip_header);
+ icmp_ttl.checksum = htons(calc_checksum((uint16_t*) &packet[off],
+ sizeof (struct icmp_ttl_exceeded_header) +
+ sizeof (struct ip_header) +
+ sizeof (struct icmp_echo_header)));
+ memcpy (&packet[off],
+ &icmp_ttl,
+ sizeof (struct icmp_ttl_exceeded_header));
memset (&dst, 0, sizeof (dst));
dst.sin_family = AF_INET;
dst.sin_addr = *other;
- err = sendto(rawsock,
- packet,
- off, 0,
- (struct sockaddr*)&dst,
- sizeof(dst)); /* or sizeof 'struct sockaddr'? */
- if (err < 0)
+
+ err = sendto(rawsock,
+ packet,
+ sizeof (packet), 0,
+ (struct sockaddr*)&dst,
+ sizeof(dst));
+
+ if (err < 0)
{
fprintf(stderr,
"sendto failed: %s\n", strerror(errno));
}
- else if (err != off)
+ else if (sizeof (packet) != (size_t) err)
{
fprintf(stderr,
"Error: partial send of ICMP message\n");
}
-static Socket
+/**
+ * Create an ICMP raw socket.
+ *
+ * @return INVALID_SOCKET on error
+ */
+static SOCKET
make_raw_socket ()
{
- const int one = 1;
- int ret;
+ DWORD bOptVal = TRUE;
+ int bOptLen = sizeof(bOptVal);
+ SOCKET ret;
ret = socket (AF_INET, SOCK_RAW, IPPROTO_RAW);
- if (-1 == ret)
+ if (INVALID_SOCKET == ret)
{
fprintf (stderr,
"Error opening RAW socket: %s\n",
strerror (errno));
- return -1;
- }
- if (setsockopt(ret, SOL_SOCKET, SO_BROADCAST,
- (char *)&one, sizeof(one)) == -1)
- fprintf(stderr,
- "setsockopt failed: %s\n",
- strerror (errno));
- if (setsockopt(ret, IPPROTO_IP, IP_HDRINCL,
- (char *)&one, sizeof(one)) == -1)
- fprintf(stderr,
- "setsockopt failed: %s\n",
- strerror (errno));
+ return INVALID_SOCKET;
+ }
+ if (0 != setsockopt(ret, 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(ret, 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 ret;
}
{
struct in_addr external;
struct in_addr target;
-#ifndef WIN32
- uid_t uid;
-#endif
-
-#ifdef WIN32
- // WSA startup
WSADATA wsaData;
- if (WSAStartup (MAKEWORD (2, 1), &wsaData) != 0)
- {
- fprintf (stderr, "Failed to find Winsock 2.1 or better.\n");
- return 4; // ERROR
- }
-#endif
- if (-1 == (rawsock = make_raw_socket()))
- return 1;
-
-#ifndef WIN32
- uid = getuid ();
- if (0 != setresuid (uid, uid, uid))
- fprintf (stderr,
- "Failed to setresuid: %s\n",
- strerror (errno));
-#endif
+ unsigned int p;
+
if (argc != 4)
{
fprintf (stderr,
"This program must be started with our IP, the targets external IP, and our port as arguments.\n");
return 1;
}
- port = atoi(argv[3]);
-
if ( (1 != inet_pton (AF_INET, argv[1], &external)) ||
(1 != inet_pton (AF_INET, argv[2], &target)) )
{
strerror (errno));
return 1;
}
+ if ( (1 != sscanf (argv[3], "%u", &p) ) ||
+ (0 == p) ||
+ (0xFFFF < p) )
+ {
+ fprintf (stderr,
+ "Error parsing port value `%s'\n",
+ argv[3]);
+ return 1;
+ }
+ port = (uint16_t) p;
+
+ if (0 != WSAStartup (MAKEWORD (2, 1), &wsaData))
+ {
+ fprintf (stderr, "Failed to find Winsock 2.1 or better.\n");
+ return 2;
+ }
if (1 != inet_pton (AF_INET, DUMMY_IP, &dummy))
{
fprintf (stderr,
- "Error parsing IPv4 address: %s\n",
- strerror (errno));
- abort ();
+ "Internal error converting dummy IP to binary.\n");
+ return 2;
}
+ if (-1 == (rawsock = make_raw_socket()))
+ return 3;
send_icmp (&external,
&target);
send_icmp_udp (&external,
- &target);
-
- close (rawsock);
-#ifdef WIN32
+ &target);
+ closesocket (rawsock);
WSACleanup ();
-#endif
return 0;
}
-/* end of gnunet-nat-client.c */
+/* end of gnunet-nat-client-windows.c */
projects / oweals / gnunet.git / blobdiff