*/
#define _GNU_SOURCE
-#include <ws2tcpip.h>
#include <winsock2.h>
+#include <ws2tcpip.h>
#include <sys/time.h>
#include <sys/types.h>
#include <unistd.h>
/**
* IPv4 header.
*/
-struct ip_packet
+struct ip_header
{
/**
- * Version (4 bits) + Internet header length (4 bits)
+ * Version (4 bits) + Internet header length (4 bits)
*/
- uint8_t vers_ihl;
+ uint8_t vers_ihl;
/**
* Type of service
*/
- uint8_t tos;
+ uint8_t tos;
/**
* Total length
*/
- uint16_t pkt_len;
+ uint16_t pkt_len;
/**
* Identification
*/
- uint16_t id;
+ uint16_t id;
/**
* Flags (3 bits) + Fragment offset (13 bits)
*/
- uint16_t flags_frag_offset;
+ uint16_t flags_frag_offset;
/**
* Time to live
*/
- uint8_t ttl;
+ uint8_t ttl;
/**
- * Protocol
+ * Protocol
*/
- uint8_t proto;
+ uint8_t proto;
/**
* Header checksum
*/
- uint16_t checksum;
+ uint16_t checksum;
/**
* Source address
*/
- uint32_t src_ip;
+ uint32_t src_ip;
/**
- * Destination address
+ * Destination address
*/
- uint32_t dst_ip;
+ uint32_t dst_ip;
};
/**
* Format of ICMP packet.
*/
-struct icmp_packet
+struct icmp_ttl_exceeded_header
{
uint8_t type;
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;
};
/**
* Beginning of UDP packet.
*/
-struct udp_packet
+struct udp_header
{
uint16_t src_port;
uint16_t dst_port;
- uint32_t length;
+ uint16_t length;
+
+ uint16_t crc;
};
/**
* Port we are listening on (communicated to the server).
- */
+ */
static uint16_t port;
* @param buf where to write the address result
* @return 1 on success
*/
-static int
-inet_pton (int af,
- const char *cp,
+static int
+inet_pton (int af,
+ const char *cp,
struct in_addr *buf)
{
buf->s_addr = inet_addr(cp);
if (buf->s_addr == INADDR_NONE)
{
- fprintf(stderr,
- "Error %d handling address %s",
- WSAGetLastError(),
+ fprintf(stderr,
+ "Error %d handling address %s",
+ WSAGetLastError(),
cp);
return 0;
}
* @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,
+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;
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_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);
udp_pkt.dst_port = htons(NAT_TRAV_PORT);
-
- memset(&udp_pkt.length, 0, sizeof(uint32_t));
udp_pkt.length = htons (port);
- memcpy(&packet[off], &udp_pkt, sizeof(udp_pkt));
- off += sizeof(udp_pkt);
+ 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 */
- off = sizeof (ip_pkt);
icmp_pkt.checksum = htons(calc_checksum((uint16_t*)&packet[off],
- sizeof (icmp_pkt) + sizeof(ip_pkt) + sizeof(udp_pkt)));
- memcpy (&packet[off], &icmp_pkt, sizeof (icmp_pkt));
+ 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;
sizeof (packet), 0,
(struct sockaddr*)&dst,
sizeof(dst));
-
if (err < 0)
{
fprintf(stderr,
"sendto failed: %s\n", strerror(errno));
}
- else if (err != sizeof (packet))
+ 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;
- memset(packet, 0, sizeof(packet));
/* 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);
- memset (&dst, 0, sizeof (dst));
- dst.sin_family = AF_INET;
- dst.sin_addr = *other;
/* 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 = 0;
+ icmp_echo.reserved = htonl(port);
icmp_echo.checksum = 0;
- icmp_echo.data = htons(port);
- icmp_echo.checksum = htons(calc_checksum((uint16_t*) &icmp_echo,
- sizeof (struct icmp_echo_packet)));
+ 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));
- memcpy (&packet[off], &icmp_echo, sizeof(struct icmp_echo_packet));
- off += sizeof (struct icmp_echo_packet);
+ /* 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));
- 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[0],
- off, 0,
- (struct sockaddr*)&dst,
- sizeof(dst)); /* or sizeof 'struct sockaddr'? */
+ err = sendto(rawsock,
+ packet,
+ sizeof (packet), 0,
+ (struct sockaddr*)&dst,
+ sizeof(dst));
- 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");
"Error opening RAW socket: %s\n",
strerror (errno));
return INVALID_SOCKET;
- }
- if (setsockopt(ret, SOL_SOCKET, SO_BROADCAST, (char*)&bOptVal, bOptLen) != 0)
+ }
+ if (0 != setsockopt(ret, SOL_SOCKET, SO_BROADCAST, (char*)&bOptVal, bOptLen))
{
- fprintf(stderr,
+ fprintf(stderr,
"Error setting SO_BROADCAST to ON: %s\n",
strerror (errno));
closesocket(rawsock);
return INVALID_SOCKET;
}
- if (setsockopt(ret, IPPROTO_IP, IP_HDRINCL, (char*)&bOptVal, bOptLen) != 0)
+ if (0 != setsockopt(ret, IPPROTO_IP, IP_HDRINCL, (char*)&bOptVal, bOptLen))
{
- fprintf(stderr,
+ fprintf(stderr,
"Error setting IP_HDRINCL to ON: %s\n",
strerror (errno));
closesocket(rawsock);
return 1;
}
if ( (1 != sscanf (argv[3], "%u", &p) ) ||
- (p == 0) ||
- (p > 0xFFFF) )
+ (0 == p) ||
+ (0xFFFF < p) )
{
fprintf (stderr,
"Error parsing port value `%s'\n",
}
port = (uint16_t) p;
- if (WSAStartup (MAKEWORD (2, 1), &wsaData) != 0)
+ 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))
+ if (1 != inet_pton (AF_INET, DUMMY_IP, &dummy))
{
fprintf (stderr,
"Internal error converting dummy IP to binary.\n");
projects / oweals / gnunet.git / blobdiff