diff options
| -rw-r--r-- | src/options.c | 15 | ||||
| -rw-r--r-- | src/options.h | 1 | ||||
| -rw-r--r-- | src/pkt.c | 5 | ||||
| -rw-r--r-- | src/ptunnel.c | 10 |
4 files changed, 28 insertions, 3 deletions
diff --git a/src/options.c b/src/options.c index 85b8a9c..66c44a6 100644 --- a/src/options.c +++ b/src/options.c @@ -144,7 +144,7 @@ static const struct option_usage usage[] = { /** --ack-interval */ {"milliseconds", 0, OPT_DEC32, {.unum = 1000}, "Tune the explicit acknowledgement interval (in milliseconds)\n" - "Decreasing the acknowlegement interval can improve NAT stability.\n" + "Decreasing the acknowledgement interval can improve NAT stability.\n" }, /** --resend-interval */ {"milliseconds", 0, OPT_DEC32, {.unum = 1500}, @@ -157,6 +157,11 @@ static const struct option_usage usage[] = { "Decreasing the payload size can avoid corruption of large packets.\n" "Increasing the payload size can compensate for out-of-order delivery.\n" }, + /** --empty-pings */ + {"count", 0, OPT_DEC32, {.unum = 0}, + "Tune the number of empty pings to send with each explicit acknowledgement.\n" + "Empty pings can compensate for ICMP sequence number inspection.\n" + }, /** --daemon */ {"pidfile", 0, OPT_STR, {.str = "/run/ptunnel.pid"}, #ifdef WIN32 @@ -223,6 +228,7 @@ static struct option long_options[] = { {"ack-interval", required_argument, 0, 'a'}, {"resend-interval", required_argument, 0, 't'}, {"payload-size", required_argument, 0, 'y'}, + {"empty-pings", required_argument, 0, 'E'}, {"daemon", optional_argument, 0, 'd'}, {"syslog", no_argument, 0, 'S'}, {"user", optional_argument, 0, 'u'}, @@ -409,7 +415,7 @@ int parse_options(int argc, char **argv) { * since you have to pass long options as '--option=value'. Commonly used * '--option value' is *NOT* allowed for some libc implementations. */ - c = getopt_long(argc, argv, "m:p:l:r::R::c:v:L::o::sP:d::Su::g::C::e::w:a:t:y:h", &long_options[0], &oidx); + c = getopt_long(argc, argv, "m:p:l:r::R::c:v:L::o::sP:d::Su::g::C::e::w:a:t:y:E:h", &long_options[0], &oidx); if (c == -1) break; switch (c) { @@ -578,6 +584,11 @@ int parse_options(int argc, char **argv) { break; opts.payload_size = atoi(optarg); break; + case 'E': + if (!optarg) + break; + opts.empty_pings = atoi(optarg); + break; case 'h': print_usage(argv[0]); exit(EXIT_SUCCESS); diff --git a/src/options.h b/src/options.h index b180ef5..7afcfec 100644 --- a/src/options.h +++ b/src/options.h @@ -92,6 +92,7 @@ struct options { uint16_t ack_interval; uint16_t resend_interval; uint16_t payload_size; + uint16_t empty_pings; #ifndef WIN32 /** run as daemon if non zero value */ @@ -96,6 +96,7 @@ void handle_packet(char *buf, unsigned bytes, int is_pcap, struct sockaddr_in *a if (ntohl(pt_pkt->magic) == opts.magic) { pt_pkt->state = ntohl(pt_pkt->state); pkt->identifier = ntohs(pkt->identifier); + pkt->seq = ntohs(pkt->seq); pt_pkt->id_no = ntohs(pt_pkt->id_no); pt_pkt->seq_no = ntohs(pt_pkt->seq_no); /* Find the relevant connection, if it exists */ @@ -114,8 +115,10 @@ void handle_packet(char *buf, unsigned bytes, int is_pcap, struct sockaddr_in *a */ if (cur) { type_flag = cur->type_flag; - if (type_flag == (uint32_t)kProxy_flag) + if (type_flag == (uint32_t)kProxy_flag) { cur->icmp_id = pkt->identifier; + cur->ping_seq = pkt->seq; + } if (!is_pcap) cur->xfer.icmp_in++; } diff --git a/src/ptunnel.c b/src/ptunnel.c index 3f12556..640df74 100644 --- a/src/ptunnel.c +++ b/src/ptunnel.c @@ -661,12 +661,22 @@ void* pt_proxy(void *args) { if (cur->last_ack+cur->ack_interval < now && cur->send_wait_ack < cur->window_size && cur->remote_ack_val+1 != cur->next_remote_seq) { + idx = cur->send_idx; cur->last_ack = now; queue_packet(fwd_sock, cur->pkt_type, 0, 0, cur->id_no, cur->icmp_id, &cur->my_seq, cur->send_ring, &cur->send_idx, &cur->send_wait_ack, cur->dst_ip, cur->dst_port, kProto_ack | cur->type_flag, &cur->dest_addr, cur->next_remote_seq, &cur->send_first_ack, &cur->ping_seq, cur->window_size); cur->xfer.icmp_ack_out++; + if (cur->send_ring[idx].pkt_len > sizeof(icmp_echo_packet_t) && cur->send_ring[idx].pkt->type == 8) { + for (uint16_t e = 0; e < opts.empty_pings; e++) { + cur->send_ring[idx].pkt->seq = htons(cur->ping_seq); + cur->ping_seq++; + cur->send_ring[idx].pkt->checksum = htons(calc_icmp_checksum((uint16_t*)cur->send_ring[idx].pkt, sizeof(icmp_echo_packet_t))); + sendto(fwd_sock, (const void*)cur->send_ring[idx].pkt, sizeof(icmp_echo_packet_t), + 0, (struct sockaddr*)&cur->dest_addr, sizeof(struct sockaddr)); + } + } } } pthread_mutex_unlock(&chain_lock); |