#include <stdint.h>
#include <time.h>
+/**
+ * Should we print some debug output?
+ */
+#define VERBOSE 0
+
+
typedef unsigned int uid_t;
typedef SOCKET Socket;
typedef unsigned short ushort;
*/
#define DUMMY_IP "192.0.2.86"
-#define VERBOSE 1
-
/**
* How often do we send our ICMP messages to receive replies?
*/
#define ICMP_SEND_FREQUENCY_MS 500
+/**
+ * IPv4 header.
+ */
struct ip_packet
{
- /*uint8_t vers_ihl;
- uint8_t tos;
- uint16_t pkt_len;
- uint16_t id;
- uint16_t flags_frag_offset;
- uint8_t ttl;
- uint8_t proto;
- uint16_t checksum;
- uint32_t src_ip;
- uint32_t dst_ip;*/
-
- u_char vers_ihl; // Version (4 bits) + Internet header length (4 bits)
- u_char tos; // Type of service
- u_short pkt_len; // Total length
- u_short id; // Identification
- u_short flags_frag_offset; // Flags (3 bits) + Fragment offset (13 bits)
- u_char ttl; // Time to live
- u_char proto; // Protocol
- u_short checksum; // Header checksum
- u_long src_ip; // Source address
- u_long dst_ip; // Destination address
+
+ /**
+ * Version (4 bits) + Internet header length (4 bits)
+ */
+ u_char vers_ihl;
+
+ /**
+ * Type of service
+ */
+ u_char tos;
+
+ /**
+ * Total length
+ */
+ u_short pkt_len;
+
+ /**
+ * Identification
+ */
+ u_short id;
+
+ /**
+ * Flags (3 bits) + Fragment offset (13 bits)
+ */
+ u_short flags_frag_offset;
+
+ /**
+ * Time to live
+ */
+ u_char ttl;
+
+ /**
+ * Protocol
+ */
+ u_char proto;
+
+ /**
+ * Header checksum
+ */
+ u_short checksum;
+
+ /**
+ * Source address
+ */
+ u_long src_ip;
+
+ /**
+ * Destination address
+ */
+ u_long dst_ip;
};
+/**
+ * Format of ICMP packet.
+ */
struct icmp_packet
{
uint8_t type;
uint32_t reserved;
};
+/**
+ * Beginning of UDP packet.
+ */
struct udp_packet
{
uint16_t src_port;
static struct in_addr dummy;
+/**
+ * CRC-16 for IP/ICMP headers.
+ */
static uint16_t
calc_checksum(const uint16_t *data,
unsigned int bytes)
}
/**
+ * 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
*/
-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;
-}
-
-static void
-make_echo (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)));
+ return 1;
}
memcpy (packet, &ip_pkt, sizeof (ip_pkt));
off += sizeof (ip_pkt);
- make_echo (my_ip, &icmp_echo);
+ 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_packet)));
memcpy (&packet[off], &icmp_echo, sizeof (icmp_echo));
off += sizeof (icmp_echo);
int have_port;
int have_udp;
uint32_t port;
+
have = read (icmpsock, buf, sizeof (buf));
if (have == -1)
{
memcpy(&sip,
&ip_pkt.src_ip,
sizeof (sip));
-
memcpy (&ip_pkt, &buf[off], sizeof (ip_pkt));
off += sizeof (ip_pkt);
-
- have_udp = 0;
- if (ip_pkt.proto == IPPROTO_UDP)
- {
- have_udp = 1;
- }
+ have_udp = (ip_pkt.proto == IPPROTO_UDP);
if (have_port)
{
- memcpy(&port, &buf[sizeof (struct ip_packet) *2 + sizeof (struct icmp_packet) * 2], sizeof(uint32_t));
+ memcpy(&port,
+ &buf[sizeof (struct ip_packet) *2 + sizeof (struct icmp_packet) * 2],
+ sizeof(uint32_t));
port = ntohs(port);
DWORD ssize = sizeof(buf);
- WSAAddressToString((LPSOCKADDR)&sip, sizeof(sip), NULL, buf, &ssize);
- fprintf (stdout, "%s:%d\n", buf, port);
-
+ WSAAddressToString((LPSOCKADDR)&sip,
+ sizeof(sip),
+ NULL,
+ buf,
+ &ssize);
+ fprintf (stdout,
+ "%s:%d\n",
+ buf,
+ port);
}
else if (have_udp)
{
- memcpy(&udp_pkt, &buf[off], sizeof(udp_pkt));
+ memcpy(&udp_pkt,
+ &buf[off],
+ sizeof(udp_pkt));
DWORD ssize = sizeof(buf);
- WSAAddressToString((LPSOCKADDR)&sip, sizeof(sip), NULL, buf, &ssize);
- fprintf (stdout, "%s:%d\n", buf, ntohs((int)udp_pkt.length));
+ WSAAddressToString((LPSOCKADDR)&sip,
+ sizeof(sip),
+ NULL,
+ buf,
+ &ssize);
+ fprintf (stdout,
+ "%s:%d\n",
+ buf,
+ ntohs((int)udp_pkt.length));
}
else
{
DWORD ssize = sizeof(buf);
- WSAAddressToString((LPSOCKADDR)&sip, sizeof(sip), NULL, buf, &ssize);
- fprintf (stdout, "%s\n", buf);
+ WSAAddressToString((LPSOCKADDR)&sip,
+ sizeof(sip),
+ NULL,
+ buf,
+ &ssize);
+ fprintf (stdout,
+ "%s\n",
+ buf);
}
fflush (stdout);
}
Socket ret;
ret = socket (AF_INET, SOCK_RAW, IPPROTO_ICMP);
- if (-1 == ret)
+ if (INVALID_SOCKET == ret)
{
fprintf (stderr,
"Error opening RAW socket: %s\n",
strerror (errno));
return -1;
}
- if (ret == INVALID_SOCKET)
- {
- fprintf (stderr, "Invalid socket %d!\n", ret);
- closesocket (ret);
- }
return ret;
}
int bOptLen = sizeof(bOptVal);
rawsock = socket (AF_INET, SOCK_RAW, IPPROTO_ICMP);
- if (-1 == rawsock)
+ if (INVALID_SOCKET == rawsock)
{
fprintf (stderr,
"Error opening RAW socket: %s\n",
strerror (errno));
- return -1;
+ return INVALID_SOCKET;
}
- if (setsockopt(rawsock, SOL_SOCKET, SO_BROADCAST, (char*)&bOptVal, bOptLen) != 0)
- fprintf(stderr, "Error setting SO_BROADCAST: ON\n");
-
- if (setsockopt(rawsock, IPPROTO_IP, IP_HDRINCL, (char*)&bOptVal, bOptLen) != 0)
- fprintf(stderr, "Error setting IP_HDRINCL: ON\n");
+ if (setsockopt(rawsock,
+ SOL_SOCKET,
+ SO_BROADCAST,
+ (char*)&bOptVal, bOptLen) != 0)
+ {
+ fprintf(stderr,
+ "Error setting SO_BROADCAST to ON: %s\n",
+ strerror (errno));
+ closesocket(rawsock);
+ return INVALID_SOCKET;
+ }
+ if (setsockopt(rawsock,
+ IPPROTO_IP,
+ IP_HDRINCL,
+ (char*)&bOptVal, bOptLen) != 0)
+ {
+ fprintf(stderr,
+ "Error setting IP_HDRINCL to ON: %s\n",
+ strerror (errno));
+ closesocket(rawsock);
+ return INVALID_SOCKET;
+ }
return rawsock;
}
int
-main (int argc, char *const *argv)
+main (int argc,
+ char *const *argv)
{
struct in_addr external;
fd_set rs;
struct timeval tv;
-
- // 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
- }
-
- if (-1 == (icmpsock = make_icmp_socket()))
- return 1;
- if (-1 == (make_raw_socket()))
- {
- close (icmpsock);
- return 1;
- }
if (argc != 2)
{
"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,
argv[1], strerror (errno));
return 1;
}
-
- if (1 != inet_pton (AF_INET, DUMMY_IP, &dummy)) abort ();
+ if (1 != inet_pton (AF_INET, DUMMY_IP, &dummy))
+ {
+ 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 (-1 == (icmpsock = make_icmp_socket()))
+ {
+ return 3;
+ }
+ if (-1 == (make_raw_socket()))
+ {
+ closesocket (icmpsock);
+ return 3;
+ }
while (1)
{
FD_ZERO (&rs);
FD_SET (icmpsock, &rs);
tv.tv_sec = 0;
tv.tv_usec = ICMP_SEND_FREQUENCY_MS * 1000;
- select (icmpsock + 1, &rs, NULL, NULL, &tv);
+ if (0 != 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 ();
send_icmp_echo (&external);
- }
-
+ }
closesocket(icmpsock);
closesocket(rawsock);
WSACleanup ();
- return 0;
+ return 4; /* select failed! */
}
projects / oweals / gnunet.git / commitdiff