X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=src%2Ftransport%2Fgnunet-nat-client-windows.c;h=2e7c8a86e4d0ccfd40cfa803fea53c9fd687581f;hb=accae6c152eaacdf41b6069b88b3e5744ff06bba;hp=e5979dd24b8f0c2325814496121ce8c907a74a4f;hpb=41f87224c6062537921a3bdedfd0af071d628122;p=oweals%2Fgnunet.git diff --git a/src/transport/gnunet-nat-client-windows.c b/src/transport/gnunet-nat-client-windows.c index e5979dd24..2e7c8a86e 100644 --- a/src/transport/gnunet-nat-client-windows.c +++ b/src/transport/gnunet-nat-client-windows.c @@ -42,17 +42,9 @@ * - Nathan Evans */ #define _GNU_SOURCE -#ifdef WIN32 + #include -#else -#include -#include -#include -#include -#include -#include -#include -#endif +#include #include #include #include @@ -64,17 +56,9 @@ #include -#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. @@ -83,173 +67,172 @@ typedef int Socket; #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> 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))); -} - -static void -make_echo2 (const struct in_addr *src_ip, - struct icmp_packet *echo) -{ - memset(echo, 0, sizeof(struct icmp_packet)); - echo->type = ICMP_ECHO; - echo->code = 0; - echo->reserved = 0; - echo->checksum = 0; - echo->checksum = htons(calc_checksum((uint16_t*)echo, sizeof (struct icmp_packet))); -} - -/** - * Send an ICMP message to the dummy IP. - * - * @param my_ip source address (our ip address) - */ -static void -send_icmp_echo (const struct in_addr *my_ip) -{ - struct icmp_packet icmp_echo; - struct sockaddr_in dst; - size_t off; - int err; - struct ip_packet ip_pkt; - struct icmp_packet icmp_pkt; - char packet[sizeof (ip_pkt) + sizeof (icmp_pkt)]; - - off = 0; - memset(&ip_pkt, 0, sizeof(ip_pkt)); - ip_pkt.vers_ihl = 0x45; - ip_pkt.tos = 0; - ip_pkt.pkt_len = sizeof (packet); - ip_pkt.id = 1; - 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 (ip_pkt))); - memcpy (packet, &ip_pkt, sizeof (ip_pkt)); - off += sizeof (ip_pkt); - make_echo2 (my_ip, &icmp_echo); - memcpy (&packet[off], &icmp_echo, sizeof (icmp_echo)); - off += sizeof (icmp_echo); - - 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)); - - fprintf(stderr, "Sent %d bytes\n", err); - if (err < 0) - { -#if VERBOSE - fprintf(stderr, - "sendto failed: %s\n", strerror(errno)); -#endif - } - else if (err != off) - { - fprintf(stderr, - "Error: partial send of ICMP message\n"); - } -} - /** * Send an ICMP message to the target. * @@ -260,19 +243,18 @@ static void 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)); @@ -283,27 +265,27 @@ send_icmp_udp (const struct in_addr *my_ip, 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; @@ -311,42 +293,46 @@ send_icmp_udp (const struct in_addr *my_ip, 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)); - - fprintf(stderr, "Sent %d bytes\n", err); - 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"); @@ -364,94 +350,99 @@ static void 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; - - dst.sin_family = AF_INET; - //dst.sin_addr = *other; - dst.sin_addr = dummy; - - err = sendto(rawsock, - packet, - off - 20, 0, - (struct sockaddr*)&dst, - sizeof(dst)); /* or sizeof 'struct sockaddr'? */ - - fprintf(stderr, "Sent %d bytes (wanted %d)\n", err, off); - - 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); - memset (&dst, 0, sizeof (dst)); - /* 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_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); + 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)); - 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))); + 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'? */ + err = sendto(rawsock, + packet, + sizeof (packet), 0, + (struct sockaddr*)&dst, + sizeof(dst)); - fprintf(stderr, "Sent %d bytes\n", err); - if (err < 0) + 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"); @@ -459,30 +450,43 @@ send_icmp (const struct in_addr *my_ip, } -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; } @@ -492,38 +496,16 @@ main (int argc, char *const *argv) { 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)) ) { @@ -532,27 +514,37 @@ main (int argc, char *const *argv) 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; } - fprintf(stderr, "Sending icmp message.\n"); - send_icmp_echo(&target); - fprintf(stderr, "Sending icmp message.\n"); + if (-1 == (rawsock = make_raw_socket())) + return 3; send_icmp (&external, &target); - fprintf(stderr, "Sending icmp udp message.\n"); send_icmp_udp (&external, - &target); - -#ifdef WIN32 + &target); + closesocket (rawsock); WSACleanup (); -#endif - close (rawsock); return 0; } -/* end of gnunet-nat-client.c */ +/* end of gnunet-nat-client-windows.c */