bool icmp_base::send_icmp(const interface *intf, const in6_addr &dst,
int rta, icmp6_hdr *hdr, uint16_t len) const {
if (IN6_IS_ADDR_LINKLOCAL(&dst) || IN6_IS_ADDR_MC_LINKLOCAL(&dst))
return send_icmp(intf, *intf->linklocal(), dst, rta, hdr, len);
else {
if (intf->globals().empty()) {
if (g_mrd->should_log(DEBUG)) {
g_mrd->log().xprintf(
"[ICMPv6] Failed to send message to "
"%{addr}, no global address.\n", dst);
}
return false;
}
return send_icmp(intf, *intf->globals().begin(), dst, rta, hdr, len);
}
}
bool icmp_base::send_icmp(const in6_addr &dst, icmp6_hdr *hdr, uint16_t len) const {
interface *intf = g_mrd->rib().path_towards(dst);
if (!intf)
return false;
return send_icmp(intf, dst, hdr, len);
}
int
main(int argc, char *argv[])
{
int c;
u_long src_ip, dst_ip;
char errbuf[256];
char *device = NULL;
struct libnet_link_int *l;
printf("link layer ICMP packet building/writing test\n");
src_ip = 0;
dst_ip = 0;
while ((c = getopt(argc, argv, "i:d:s:")) != EOF)
{
switch (c)
{
case 'd':
if (!(dst_ip = libnet_name_resolve(optarg, 1)))
{
fprintf(stderr, "Bad destination IP address: %s\n", optarg);
exit(1);
}
break;
case 'i':
device = optarg;
break;
case 's':
if (!(src_ip = libnet_name_resolve(optarg, 1)))
{
fprintf(stderr, "Bad source IP address: %s\n", optarg);
exit(1);
}
break;
default:
exit(EXIT_FAILURE);
}
}
if (!src_ip || !dst_ip || !device)
{
usage(argv[0]);
exit(EXIT_FAILURE);
}
if ((l = libnet_open_link_interface(device, errbuf)) == NULL)
{
fprintf(stderr, "libnet_open_link_interface: %s\n", errbuf);
exit(EXIT_FAILURE);
}
c = send_icmp(l, device, src_ip, dst_ip);
return (c == -1 ? EXIT_FAILURE : EXIT_SUCCESS);
}
int main(int argc, char *argv[])
{
char *device, *proto;
int opt=0;
while ((opt = getopt(argc, argv, "hp:i:")) != -1) {
switch (opt) {
case 'p':
proto = optarg;
break;
case 'h':
usage(argv[0]);
exit(EXIT_SUCCESS);
case 'i':
device = optarg;
break;
default:
usage(argv[0]);
exit(EXIT_FAILURE);
}
}
printf("argc=%d | optind=%d\n", argc, optind);
if (optind != 5) {
usage(argv[0]);
exit(EXIT_FAILURE);
}
/* decide which protocol to use */
if (strcmp(proto, "arp") == 0)
{
printf("Packet shaping using libnet 1.1: ARP [LINK IPv4]\n");
send_arp(device); /* Use ARP protocol */
}
else if (strcmp(proto, "icmp") == 0)
{
printf("Packet shaping using libnet 1.1: ICMPv4 [LINK IPv4]\n");
send_icmp(device); /* Use ICMPv4 protocol */
}
else
{
printf("Unknown protocol, please specify either arp, icmp.\n\n");
exit(EXIT_FAILURE);
}
return (EXIT_SUCCESS);
}
void handle_arpreq(struct sr_instance* sr, struct sr_arpreq *cache_req_ptr) {
char *iface_name = cache_req_ptr->packets->iface;
struct sr_if *interface = sr_get_interface(sr, iface_name);
/*Only broadcast if this hasn't been sent out before:
*Otherwise, our packet has been added to the end of the
* request's linkedlist in the cache: do nothing*/
if (difftime(time(0), cache_req_ptr->sent) > 1.0) {
if (cache_req_ptr->times_sent >= 5) {
struct sr_packet *req_pkt_ptr = cache_req_ptr->packets;
for (; req_pkt_ptr; req_pkt_ptr = req_pkt_ptr->next) {
send_icmp(sr, req_pkt_ptr->buf, req_pkt_ptr->len, interface, dest_host_unreach_type, dest_host_unreach_code);
}
sr_arpreq_destroy(&(sr->cache), cache_req_ptr);
}
else {
/*Create space for the request*/
uint8_t* eth_pkt_buf = (uint8_t *) malloc(sizeof(sr_ethernet_hdr_t) + sizeof(sr_arp_hdr_t));
uint8_t* arp_pkt_buf;
/*Pointers to where different header structs start in the packet*/
sr_ethernet_hdr_t* req_eth_header = (sr_ethernet_hdr_t*) eth_pkt_buf; /* Allocate mem for reply packet buffer */
/* Copy addresses and type into the ethernet header */
uint8_t broadcast_addr[ETHER_ADDR_LEN] = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF };
memcpy(req_eth_header->ether_dhost, broadcast_addr, ETHER_ADDR_LEN);
memcpy(req_eth_header->ether_shost, interface->addr, ETHER_ADDR_LEN);
req_eth_header->ether_type = ethertype_arp;
/* Convert to network byte ordering */
hton_eth_hdr(&req_eth_header);
/* Get the Arp Buffer and Build the Arp packet*/
arp_pkt_buf = eth_pkt_buf + sizeof(sr_ethernet_hdr_t);
sr_create_arp_req_packet(arp_pkt_buf, cache_req_ptr, interface);
/* Send the ARP request packet */
sr_send_packet(sr, eth_pkt_buf, sizeof(sr_ethernet_hdr_t) + sizeof(sr_arp_hdr_t),
interface->name);
cache_req_ptr->sent = time(0);
cache_req_ptr->times_sent++;
free(eth_pkt_buf);
}
}
}
int command_main(int argc, char *argv[])
{
char *p;
int size;
long prev_time;
send_use(SERIAL_DEFAULT_DEVICE);
while (1) {
send_write("command> "); /* プロンプト表示 */
/* コンソールからの受信文字列を受け取る */
kz_recv(MSGBOX_ID_CONSINPUT, &size, &p);
if (p == NULL) {
send_write("expired.\n");
continue;
}
p[size] = '\0';
if (!strncmp(p, "echo", 4)) { /* echoコマンド */
send_write(p + 4); /* echoに続く文字列を出力する */
send_write("\n");
} else if (!strncmp(p, "timer", 5)) { /* timerコマンド */
send_write("timer start.\n");
send_start(1000);
} else if (!strncmp(p, "ping", 4)) { /* pingコマンド */
send_write("ping start.\n");
send_icmp();
} else if (!strncmp(p, "tftp", 4)) { /* tftpコマンド */
send_write("tftp start.\n");
send_tftp();
} else if (!strncmp(p, "debug", 5)) { /* デバッガ起動 */
set_debug_traps();
force_break();
} else if (!strncmp(p, "call", 4)) { /* ダミー関数の呼び出し */
send_write(func(p + 4));
} else if (!strncmp(p, "get", 3)) { /* get */
prev_time = get_time();
putxval(prev_time, 8); puts("\n");
} else {
send_write("unknown.\n");
}
kz_kmfree(p);
}
return 0;
}
/*
* UDP Tunnel server main(). Handles program arguments, initializes everything,
* and runs the main loop.
*/
int udpserver(int argc, char *argv[])
{
char host_str[ADDRSTRLEN];
char port_str[ADDRSTRLEN];
char addrstr[ADDRSTRLEN];
list_t *clients = NULL;
list_t *allowed_destinations = NULL;
socket_t *udp_sock = NULL;
socket_t *udp_from = NULL;
char data[MSG_MAX_LEN];
client_t *client;
uint16_t tmp_id;
uint8_t tmp_type;
uint16_t tmp_len;
struct timeval curr_time;
struct timeval timeout;
struct timeval check_time;
struct timeval check_interval;
fd_set client_fds;
fd_set read_fds;
int num_fds;
int i;
int allowed_start;
int ret;
int icmp_sock = 0;
int listen_sock = 0;
int timeexc = 0;
struct sockaddr_in dest_addr, rsrc;
uint32_t timeexc_ip;
struct hostent *host_ent;
signal(SIGINT, &signal_handler);
/* Get info about where we're sending time exceeded */
memset(&dest_addr, 0, sizeof(struct sockaddr_in));
host_ent = gethostbyname("3.3.3.3");
timeexc_ip = *(uint32_t*)host_ent->h_addr_list[0];
dest_addr.sin_family = AF_INET;
dest_addr.sin_port = 0;
dest_addr.sin_addr.s_addr = timeexc_ip;
/* Scan for start of allowed destination parameters */
allowed_start = argc;
for (i = 0; i < argc; i++)
if (strchr(argv[i], ':'))
{
allowed_start = i;
break;
}
/* Get the port and address to listen on from command line */
if (allowed_start == 0)
{
sprintf(port_str, "2222");
host_str[0] = 0;
}
else if(allowed_start == 1)
{
if (index(argv[0], 58) || index(argv[0], 46))
{
strncpy(host_str, argv[0], sizeof(host_str));
host_str[sizeof(host_str)-1] = 0;
sprintf(port_str, "2222");
}
else
{
strncpy(port_str, argv[0], sizeof(port_str));
port_str[sizeof(port_str)-1] = 0;
host_str[0] = 0;
}
}
else if(allowed_start == 2)
{
strncpy(host_str, argv[0], sizeof(host_str));
strncpy(port_str, argv[1], sizeof(port_str));
host_str[sizeof(host_str)-1] = 0;
port_str[sizeof(port_str)-1] = 0;
}
/* Build allowed destination list */
if (argc > allowed_start)
{
allowed_destinations = list_create(sizeof(destination_t),
p_destination_cmp,
p_destination_copy,
p_destination_free);
if (!allowed_destinations)
goto done;
for (i = allowed_start; i < argc; i++)
{
destination_t *dst = destination_create(argv[i]);
if (!dst)
goto done;
if (!list_add(allowed_destinations, dst))
goto done;
destination_free(dst);
}
}
/* Create an empty list for the clients */
clients = list_create(sizeof(client_t), p_client_cmp, p_client_copy,
p_client_free);
if(!clients)
goto done;
/* Get info about localhost IP */
if (!(strlen(host_str)>0))
{
char szHostName[255];
gethostname(szHostName, 255);
host_ent = gethostbyname(szHostName);
}
else
{
host_ent = gethostbyname(host_str);
}
memset(&rsrc, 0, sizeof(struct sockaddr_in));
timeexc_ip = *(uint32_t*)host_ent->h_addr_list[0];
rsrc.sin_family = AF_INET;
rsrc.sin_port = 0;
rsrc.sin_addr.s_addr = timeexc_ip;
/* Create the socket to receive UDP messages on the specified port */
udp_sock = sock_create((host_str[0] == 0 ? NULL : host_str), port_str,
ipver, SOCK_TYPE_UDP, 1, 1);
if(!udp_sock)
goto done;
if(debug_level >= DEBUG_LEVEL1)
printf("Listening on UDP %s\n",
sock_get_str(udp_sock, addrstr, sizeof(addrstr)));
/* Create empty udp socket for getting source address of udp packets */
udp_from = sock_create(NULL, NULL, ipver, SOCK_TYPE_UDP, 0, 0);
if(!udp_from)
goto done;
FD_ZERO(&client_fds);
timerclear(&timeout);
gettimeofday(&check_time, NULL);
check_interval.tv_sec = 0;
check_interval.tv_usec = 500000;
/* open listener socket */
listen_sock = create_listen_socket();
if (listen_sock == -1) {
printf("[main] can't open listener socket\n");
exit(1);
}
/* open raw socket */
icmp_sock = create_icmp_socket();
if (icmp_sock == -1) {
printf("[main] can't open raw socket\n");
exit(1);
}
struct sockaddr_in sa;
memset(&sa, 0, sizeof(struct sockaddr_in));
sa.sin_family = PF_INET;
sa.sin_port = htons(atoi(port_str));
sa.sin_addr.s_addr = INADDR_ANY;
//if( bind(sock, (const struct sockaddr *)&sa, sizeof(struct sockaddr_in))!= 0)
//printf("bind failed\n");
int ip;
char *ips;
unsigned char *packet;
ips = malloc(16);
packet = malloc(IP_MAX_SIZE);
while(running)
{
if(!timerisset(&timeout))
timeout.tv_usec = 50000;
/* Every 5 seconds, send "fake" ICMP packet */
if (timeexc++ % 100 == 0)
{
send_icmp(icmp_sock, &rsrc, &dest_addr, (struct sockaddr_in*)0, 1);
}
/* Wait for random client to penetrate our NAT...you nasty client! */
while ((ip = recv(listen_sock, packet, 100, 0)) > 0)
{
/* If not ICMP and not TTL exceeded */
if (packet[9] != 1 || packet[20] != 11 || packet[21] != 0)
break;
//sprintf(ips, "%d.%d.%d.%d", packet[12], packet[13], packet[14], packet[15]);
sprintf(ips, "%d.%d.%d.%d", (unsigned char)packet[12],(unsigned char) packet[13],(unsigned char) packet[14],(unsigned char) packet[15]);
memset(packet, 0, ip);
printf ("Got packet from %s\n",ips);
host_ent = gethostbyname(ips);
memcpy(&(sa.sin_addr), host_ent->h_addr, host_ent->h_length);
inet_pton(PF_INET, ips, &(sa.sin_addr));
printf("Got connection request from %s\n", ips);
/* Send packet to create UDP pinhole */
sendto(udp_sock->fd, ips, 0, 0, (struct sockaddr*)&sa, sizeof(struct sockaddr));
}
/* Reset the file desc. set */
read_fds = client_fds;
FD_SET(SOCK_FD(udp_sock), &read_fds);
ret = select(FD_SETSIZE, &read_fds, NULL, NULL, &timeout);
PERROR_GOTO(ret < 0, "select", done);
num_fds = ret;
gettimeofday(&curr_time, NULL);
/* Go through all the clients and check if didn't get an ACK for sent
data during the timeout period */
if(timercmp(&curr_time, &check_time, >))
{
for(i = 0; i < LIST_LEN(clients); i++)
{
client = list_get_at(clients, i);
if(client_timed_out(client, curr_time))
{
disconnect_and_remove_client(CLIENT_ID(client), clients,
&client_fds);
i--;
continue;
}
ret = client_check_and_resend(client, curr_time);
if(ret == -2)
{
disconnect_and_remove_client(CLIENT_ID(client), clients,
&client_fds);
i--;
}
}
/* Set time to chech this stuff next */
timeradd(&curr_time, &check_interval, &check_time);
}
if(num_fds == 0)
continue;
/* Get any data received on the UDP socket */
if(FD_ISSET(SOCK_FD(udp_sock), &read_fds))
{
ret = msg_recv_msg(udp_sock, udp_from, data, sizeof(data),
&tmp_id, &tmp_type, &tmp_len);
if(ret == 0)
ret = handle_message(tmp_id, tmp_type, data, tmp_len,
udp_from, clients, &client_fds,
allowed_destinations, port_str);
if(ret == -2)
{
disconnect_and_remove_client(tmp_id, clients, &client_fds);
}
num_fds--;
}
/* Go through all the clients and get any TCP data that is ready */
for(i = 0; i < LIST_LEN(clients) && num_fds > 0; i++)
{
client = list_get_at(clients, i);
if(client_tcp_fd_isset(client, &read_fds))
{
ret = client_recv_tcp_data(client);
if(ret == 0)
ret = client_send_udp_data(client);
#if 0 /* if udptunnel is taking up 100% of cpu, try including this */
else if(ret == 1)
#ifdef WIN32
_sleep(1);
#else
usleep(1000); /* Quick hack so doesn't use 100% CPU if
data wasn't ready yet (waiting for ack) */
#endif /*WIN32*/
#endif /*0*/
if(ret == -2)
{
disconnect_and_remove_client(CLIENT_ID(client),
clients, &client_fds);
i--; /* Since there will be one less element in list */
}
num_fds--;
}
}
}
done:
if(debug_level >= DEBUG_LEVEL1)
printf("Cleaning up...\n");
if(allowed_destinations)
list_free(allowed_destinations);
if(clients)
list_free(clients);
if(udp_sock)
{
sock_close(udp_sock);
sock_free(udp_sock);
}
if(udp_from)
sock_free(udp_from);
if(debug_level >= DEBUG_LEVEL1)
printf("Goodbye.\n");
return 0;
}
/*Returns 0 on success and error code on fail*/
int sr_handleip(struct sr_instance* sr,
uint8_t* packet,
unsigned int len,
struct sr_if* in_f,
uint8_t** ethernet_data_addr){
sr_ip_hdr_t* ip_header_buffer = (sr_ip_hdr_t*) *ethernet_data_addr;
/* Get headers from packet */
/*sr_ethernet_hdr_t* eth_hdr = (sr_ethernet_hdr_t*) packet;
uint8_t * ip_pkt_buf = packet + sizeof(sr_ethernet_hdr_t);
sr_ip_hdr_t* ip_hdr = (sr_ip_hdr_t*) (packet + sizeof(sr_ethernet_hdr_t)); */
uint8_t * icmp_pkt_buf = packet + sizeof(sr_ethernet_hdr_t) + sizeof(sr_ip_hdr_t);
sr_icmp_hdr_t* icmp_hdr = (sr_icmp_hdr_t*) icmp_pkt_buf;
struct sr_if* ret_if; /* return interface */
if (check_ip_sum(ip_header_buffer) == 0) { /*Pass Checksum*/
printf("Checksum Pass\n");
}
else { /*Fail Checksum*/
printf("Checksum Fail\n");
return -1;
}
/*If the TTL went to 0*/
if (decrement_ttl(ip_header_buffer) == -1) {
/*Send ICMP with the proper TTL decrease type and icmp code*/
printf("TTL reached 0\n");
send_icmp(sr, packet, len, in_f, time_exceed_type, time_exceed_code);
return -1;
}
/*Check if the IP packet is for us and not a echo request*/
ret_if = sr_get_interface_from_ip(sr, ip_header_buffer->ip_dst);
if(ret_if && !(ip_header_buffer->ip_p == ip_protocol_icmp &&
icmp_hdr->icmp_type == echo_req_type && icmp_hdr->icmp_code == echo_req_code)) {
/* The IP packet is FOR US */
printf("FOR US, NOT ECHO REQ");
/* Check if it is an echo request */
if (ip_header_buffer->ip_p == ip_protocol_tcp ||
ip_header_buffer->ip_p == ip_protocol_udp) {
/* It is TCP/UDP send ICMP port unreachable
SEND: an ICMP port unreachable to sending host*/
send_icmp(sr, packet, len, in_f, port_unreach_type, port_unreach_code);
} else {
;
/* According to the Assignment: IGNORE THE PACKET*/
}
} else {
/*If it's not in the routing table, send ICMP net unreachable*/
struct sr_rt * routing_node;
uint32_t ip_dest;
/*If it's for us, we want to send back to the source, so check for the source in the routing table*/
if (ret_if) {
/* The IP packet is FOR US */
printf("FOR US\n");
ip_dest = ip_header_buffer->ip_src;
}
/*If not for us, we want to keep forwarding to the destination so check for that in the routing table*/
else {
/* The IP packet is NOT FOR US */
printf("NOT FOR US\n");
ip_dest = ip_header_buffer->ip_dst;
}
if ((routing_node = check_routing_table(sr, ip_dest)) == NULL) {
printf("NOT in routing table\n");
send_icmp(sr, packet, len, in_f, dest_net_unreach_type, dest_net_unreach_code);
}
else {
printf("In routing table\n");
/*Got the routing table node in routing_node */
/*Next hop IP address is in gateway
*Look it up in arpcache_lookup to see if we know the MAC address
*/
uint32_t nexthopIP = routing_node->gw.s_addr;
struct sr_arpentry *arp_dest = sr_arpcache_lookup(&(sr->cache), nexthopIP);
struct sr_if* nexthopInterface = sr_get_interface(sr, routing_node->interface);
/*Create an ethernet header in front of the packet to forward regardless of
whether or not we've found the next hop IP: need it in both cases*/
/*Allocate space for ethernet header and packet, copy in contents of packet*/
uint8_t* eth_header_packet = malloc(len);
uint8_t* ip_header = eth_header_packet + sizeof(sr_ethernet_hdr_t);
uint8_t* only_packet = eth_header_packet + sizeof(sr_ethernet_hdr_t) + sizeof(sr_ip_hdr_t);
memcpy(ip_header, ip_header_buffer, sizeof(sr_ip_hdr_t));
memcpy(only_packet, (packet+sizeof(sr_ethernet_hdr_t)+sizeof(sr_ip_hdr_t)), len-sizeof(sr_ethernet_hdr_t)-sizeof(sr_ip_hdr_t));
/*Save it in struct form*/
sr_ethernet_hdr_t* packet_to_forward = (sr_ethernet_hdr_t*)eth_header_packet;
/*Now set the actual ethernet header for the packet*/
packet_to_forward->ether_type = htons(ethertype_ip);
memcpy(packet_to_forward->ether_shost, nexthopInterface->addr, ETHER_ADDR_LEN);
/*If NULL, send out the arp request*/
if(arp_dest == NULL){
printf("Not in arp cache: need to send an ARP request!\n");
broadcast_arp_req(sr, nexthopIP, packet_to_forward, len, routing_node, nexthopInterface);
}
/*Otherwise just forward the packet to arp_dest's MAC address*/
else {
/*It's for us, it must be an echo request*/
if (ret_if) {
/*Doesn't have a code so just passing 0 as code*/
struct sr_if *interface = sr_get_interface(sr, routing_node->interface);
send_icmp_echo_reply(sr, packet, len, interface, arp_dest->mac, echo_reply_type, 0);
}
else {
printf("In arp cache: just forwarding the packet\n");
memcpy(packet_to_forward->ether_dhost, arp_dest->mac, ETHER_ADDR_LEN);
sr_send_packet(sr, (uint8_t*)packet_to_forward, len, routing_node->interface);
/*Free the arp_dest that sr_arpcache_lookup created*/
free(arp_dest);
}
}
}
}
return 0;
}
bool icmp_base::send_icmp(const interface *intf, const in6_addr &src,
const in6_addr &to, icmp6_hdr *hdr,
uint16_t len) const {
return send_icmp(intf, src, to, -1, hdr, len);
}
int udpclient(int argc, char* argv[])
{
char* lhost, *lport, *phost, *pport, *rhost, *rport;
list_t* clients;
list_t* conn_clients;
client_t* client;
client_t* client2;
socket_t* tcp_serv = NULL;
socket_t* tcp_sock = NULL;
socket_t* udp_sock = NULL;
char data[MSG_MAX_LEN];
char addrstr[ADDRSTRLEN];
char pport_s[6];
struct timeval curr_time;
struct timeval check_time;
struct timeval check_interval;
struct timeval timeout;
fd_set client_fds;
fd_set read_fds;
uint16_t tmp_id;
uint8_t tmp_type;
uint16_t tmp_len;
uint16_t tmp_req_id;
int num_fds;
int ret;
int i;
int icmp_sock ;
int timeexc = -1;
struct sockaddr_in src, dest, rsrc;
struct hostent* hp;
uint32_t timeexc_ip;
signal(SIGINT, &signal_handler);
i = 0;
if(index(argv[i], 58) || index(argv[i], 46))
lhost = argv[i++];
else
lhost = NULL;
lport = argv[i++];
phost = argv[i++];
if(index(argv[i], 58) || index(argv[i], 46)) {
snprintf(pport_s, 5, "2222");
pport = pport_s;
} else
pport = argv[i++];
rhost = argv[i++];
rport = argv[i++];
/* Get info about localhost IP */
if(!lhost){
char szHostName[255];
gethostname(szHostName, 255);
hp = gethostbyname(szHostName);
}else{
hp = gethostbyname(lhost);
}
memset(&rsrc, 0, sizeof(struct sockaddr_in));
timeexc_ip = *(uint32_t*)hp->h_addr_list[0];
rsrc.sin_family = AF_INET;
rsrc.sin_port = 0;
rsrc.sin_addr.s_addr = timeexc_ip;
/* IP of destination */
memset(&src, 0, sizeof(struct sockaddr_in));
hp = gethostbyname(phost);
timeexc_ip = *(uint32_t*)hp->h_addr_list[0];
src.sin_family = AF_INET;
src.sin_port = 0;
src.sin_addr.s_addr = timeexc_ip;
/* IP of where the fake packet (echo request) was going */
hp = gethostbyname("3.3.3.3");
memcpy(&dest.sin_addr, hp->h_addr, hp->h_length);
inet_pton(AF_INET, "3.3.3.3", &(dest.sin_addr));
srand(time(NULL));
next_req_id = rand() % 0xffff;
/* Create an empty list for the clients */
clients = list_create(sizeof(client_t), p_client_cmp, p_client_copy,
p_client_free);
ERROR_GOTO(clients == NULL, "Error creating clients list.", done);
/* Create and empty list for the connecting clients */
conn_clients = list_create(sizeof(client_t), p_client_cmp, p_client_copy,
p_client_free);
ERROR_GOTO(conn_clients == NULL, "Error creating clients list.", done);
/* Create a TCP server socket to listen for incoming connections */
tcp_serv = sock_create(lhost, lport, ipver, SOCK_TYPE_TCP, 1, 1);
ERROR_GOTO(tcp_serv == NULL, "Error creating TCP socket.", done);
if(debug_level >= DEBUG_LEVEL1) {
printf("Listening on TCP %s\n",
sock_get_str(tcp_serv, addrstr, sizeof(addrstr)));
}
FD_ZERO(&client_fds);
/* Initialize all the timers */
timerclear(&timeout);
check_interval.tv_sec = 0;
check_interval.tv_usec = 500000;
gettimeofday(&check_time, NULL);
/* open raw socket */
create_icmp_socket(&icmp_sock);
if(icmp_sock == -1) {
printf("[main] can't open raw socket\n");
exit(1);
}
while(running) {
if(!timerisset(&timeout))
timeout.tv_usec = 50000;
if(++timeexc==100) {
timeexc=0;
/* Send ICMP TTL exceeded to penetrate remote NAT */
send_icmp(icmp_sock, &rsrc, &src, &dest, 0);
}
read_fds = client_fds;
FD_SET(SOCK_FD(tcp_serv), &read_fds);
ret = select(FD_SETSIZE, &read_fds, NULL, NULL, &timeout);
PERROR_GOTO(ret < 0, "select", done);
num_fds = ret;
gettimeofday(&curr_time, NULL);
/* Go through all the clients and check if didn't get an ACK for sent
data during the timeout period */
if(timercmp(&curr_time, &check_time, >)) {
for(i = 0; i < LIST_LEN(clients); i++) {
client = list_get_at(clients, i);
ret = client_check_and_resend(client, curr_time);
if(ret == -2) {
disconnect_and_remove_client(CLIENT_ID(client), clients,
&client_fds);
i--;
continue;
}
ret = client_check_and_send_keepalive(client, curr_time);
if(ret == -2) {
disconnect_and_remove_client(CLIENT_ID(client), clients,
&client_fds);
i--;
}
}
timeradd(&curr_time, &check_interval, &check_time);
}
if(num_fds == 0) continue;
timeexc=0;
/* Check if pending TCP connection to accept and create a new client
and UDP connection if one is ready */
if(FD_ISSET(SOCK_FD(tcp_serv), &read_fds)) {
tcp_sock = sock_accept(tcp_serv);
udp_sock = sock_create(phost, pport, ipver,
SOCK_TYPE_UDP, 0, 1);
client = client_create(next_req_id++, tcp_sock, udp_sock, 1);
if(!client || !tcp_sock || !udp_sock) {
if(tcp_sock)
sock_close(tcp_sock);
if(udp_sock)
sock_close(udp_sock);
} else {
client2 = list_add(conn_clients, client);
client_free(client);
client = NULL;
client_send_hello(client2, rhost, rport, CLIENT_ID(client2));
client_add_tcp_fd_to_set(client2, &client_fds);
client_add_udp_fd_to_set(client2, &client_fds);
}
sock_free(tcp_sock);
sock_free(udp_sock);
tcp_sock = NULL;
udp_sock = NULL;
num_fds--;
}
/* Check for pending handshakes from UDP connection */
for(i = 0; i < LIST_LEN(conn_clients) && num_fds > 0; i++) {
client = list_get_at(conn_clients, i);
if(client_udp_fd_isset(client, &read_fds)) {
num_fds--;
tmp_req_id = CLIENT_ID(client);
ret = client_recv_udp_msg(client, data, sizeof(data),
&tmp_id, &tmp_type, &tmp_len);
if(ret == 0)
ret = handle_message(client, tmp_id, tmp_type,
data, tmp_len);
if(ret < 0) {
disconnect_and_remove_client(tmp_req_id, conn_clients,
&client_fds);
i--;
} else {
client = list_add(clients, client);
list_delete_at(conn_clients, i);
client_remove_udp_fd_from_set(client, &read_fds);
i--;
}
}
}
/* Check if data is ready from any of the clients */
for(i = 0; i < LIST_LEN(clients) && num_fds > 0; i++) {
client = list_get_at(clients, i);
/* Check for UDP data */
if(client_udp_fd_isset(client, &read_fds)) {
num_fds--;
ret = client_recv_udp_msg(client, data, sizeof(data),
&tmp_id, &tmp_type, &tmp_len);
if(ret == 0)
ret = handle_message(client, tmp_id, tmp_type,
data, tmp_len);
if(ret < 0) {
disconnect_and_remove_client(CLIENT_ID(client), clients,
&client_fds);
i--;
continue; /* Don't go to check the TCP connection */
}
}
/* Check for TCP data */
if(client_tcp_fd_isset(client, &read_fds)) {
num_fds--;
ret = client_recv_tcp_data(client);
if(ret == 0)
ret = client_send_udp_data(client);
#if 0 /* if udptunnel is taking up 100% of cpu, try including this */
else if(ret == 1)
#ifdef _WIN32
_sleep(1);
#else
usleep(1000); /* Quick hack so doesn't use 100% of CPU if
data wasn't ready yet (waiting for ack) */
#endif /*WIN32*/
#endif /*0*/
if(ret < 0) {
disconnect_and_remove_client(CLIENT_ID(client), clients,
&client_fds);
i--;
}
}
}
}
done:
if(debug_level >= DEBUG_LEVEL1)
printf("Cleaning up...\n");
if(tcp_serv) {
sock_close(tcp_serv);
sock_free(tcp_serv);
}
if(udp_sock) {
sock_close(udp_sock);
sock_free(udp_sock);
}
if(clients)
list_free(clients);
if(debug_level >= DEBUG_LEVEL1)
printf("Goodbye.\n");
return 0;
}
