initial whatever

Signed-off-by: Toni Uhlig <matzeton@googlemail.com>

1 files changed, 12 insertions, 862 deletions

diff --git a/src/ptunnel.c b/src/ptunnel.c
index ac6ff4f..d0f5823 100644
--- a/src/ptunnel.c
+++ b/src/ptunnel.c
@@ -1,871 +1,21 @@
-/*
- * ptunnel.c
- * ptunnel is licensed under the BSD license:
- *
- * Copyright (c) 2004-2011, Daniel Stoedle <daniels@cs.uit.no>,
- * Yellow Lemon Software. All rights reserved.
- *
- * Copyright (c) 2017-2019, Toni Uhlig <matzeton@googlemail.com>
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are met:
- *
- * - Redistributions of source code must retain the above copyright notice,
- *   this list of conditions and the following disclaimer.
- *
- * - Redistributions in binary form must reproduce the above copyright notice,
- *   this list of conditions and the following disclaimer in the documentation
- *   and/or other materials provided with the distribution.
- *
- * - Neither the name of the Yellow Lemon Software nor the names of its
- *   contributors may be used to endorse or promote products derived from this
- *   software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
- * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
- * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
- * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
- * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
- * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
- * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
- * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
- * POSSIBILITY OF SUCH DAMAGE.
- *
- * Contacting the author:
- * You can get in touch with me, Daniel Stoedle (that's the Norwegian letter oe,
- * in case your text editor didn't realize), here: <daniels@cs.uit.no>
- *
- * The official ptunnel website is here:
- * <http://www.cs.uit.no/~daniels/PingTunnel/>
- *
- * Note that the source code is best viewed with tabs set to 4 spaces.
- */
-#ifdef HAVE_CONFIG_H
-#include "config.h"
-#endif
-#include "ptunnel.h"
-#include "options.h"
-#include "utils.h"
-#include "md5.h"
-#ifdef HAVE_SELINUX
-#include <selinux/selinux.h>
-#endif
+#include "psock.h"
 
-#ifndef PACKAGE_STRING
-#define PACKAGE_STRING "ptunnel-ng"
-#endif
+#include <stdio.h>
+#include <stdlib.h>
 
-#ifdef WIN32
-#include <tchar.h>
-#include <winsock2.h>
-/* Map errno (which Winsock doesn't use) to GetLastError; include the code in the strerror */
-#ifdef errno
-#undef errno
-#endif /* errno */
-#define errno GetLastError()
-/** Local error string storage */
-static char errorstr[255];
-static char * print_last_windows_error() {
-	char last_errorstr[255];
-	DWORD last_error = GetLastError();
 
-	memset(last_errorstr, 0, sizeof(last_errorstr));
-	FormatMessage(FORMAT_MESSAGE_IGNORE_INSERTS | FORMAT_MESSAGE_FROM_SYSTEM,
-	              NULL, last_error, 0, last_errorstr, sizeof(last_errorstr), NULL);
-	snprintf(errorstr, sizeof(errorstr), "%s (%lu)", last_errorstr, last_error);
-	return errorstr;
-}
-#define strerror(x) print_last_windows_error()
-#endif /* WIN32 */
-
-#ifdef HAVE_NPCAP
-static BOOL LoadNpcapDlls()
-{
-	TCHAR npcap_dir[512];
-	UINT len;
-	len = GetSystemDirectory(npcap_dir, 480);
-	if (!len) {
-		pt_log(kLog_error, "Error in GetSystemDirectory: %x", GetLastError());
-		return FALSE;
-	}
-	_tcscat_s(npcap_dir, 512, _T("\\Npcap"));
-	if (SetDllDirectory(npcap_dir) == 0) {
-		pt_log(kLog_error, "Error in SetDllDirectory: %x", GetLastError());
-		return FALSE;
-	}
-	return TRUE;
-}
-#endif
-
-/* globals */
-/** Lock protecting the chain of connections */
-pthread_mutex_t chain_lock;
-/** Lock protecting the num_threads variable */
-pthread_mutex_t num_threads_lock;
-/** Current thread count */
-int num_threads = 0;
-/** Current tunnel count */
-uint32_t num_tunnels = 0;
-/** Table indicating when a connection ID is allowable (used by proxy) */
-time_t *seq_expiry_tbl = NULL;
-
-/* Some buffer constants */
-const int tcp_receive_buf_len  = kDefault_buf_size;
-const int icmp_receive_buf_len = kDefault_buf_size + kIP_header_size +
-                                 kICMP_header_size + sizeof(ping_tunnel_pkt_t);
-const int pcap_buf_size        = (kDefault_buf_size + kIP_header_size +
-                                 kICMP_header_size + sizeof(ping_tunnel_pkt_t)+64)*64;
-/** (icmp[icmptype] = icmp-echo || icmp[icmptype] = icmp-echoreply) */
-char pcap_filter_program[]     = "icmp";
-
-/** The chain of client/proxy connections */
-proxy_desc_t *chain = 0;
-const char *state_name[kNum_proto_types] = { "start", "ack  ", "data ",
-                                             "close", "authenticate" };
-
-#ifdef HAVE_PCAP
-static void print_pcap_devices(void) {
-	pcap_if_t *devs, *cur_dev;
-	pcap_addr_t *cur_addr;
-	char errbuf[PCAP_ERRBUF_SIZE+1];
-
-	if (pcap_findalldevs(&devs, errbuf)) {
-		pt_log(kLog_error, "List all available pcap devices failed: %s.\n", errbuf);
-	}
-	printf("Available pcap devices:\n");
-	for (cur_dev = devs; cur_dev; cur_dev = cur_dev->next) {
-		if (cur_dev->description)
-			printf("\n\t%s%c '%s'\n", cur_dev->name, (cur_dev->addresses ? ':' : ' '),
-				cur_dev->description);
-		else
-			printf("\n\t%s%c\n", cur_dev->name, (cur_dev->addresses ? ':' : ' '));
-		for (cur_addr = cur_dev->addresses; cur_addr; cur_addr = cur_addr->next) {
-			if (cur_addr->addr->sa_family == AF_INET)
-				printf("\t\t%s\n", inet_ntoa(((struct sockaddr_in*)cur_addr->addr)->sin_addr));
-		}
-	}
-	pcap_freealldevs(devs);
-}
-#endif
-
-/* Let the fun begin! */
-int main(int argc, char *argv[]) {
-#ifndef WIN32
-	pid_t   pid;
-#endif
-#ifdef WIN32
-	WORD    wVersionRequested;
-	WSADATA wsaData;
-	int     err;
-
-	wVersionRequested = MAKEWORD(2, 2);
-
-	err = WSAStartup( wVersionRequested, &wsaData );
-	if ( err != 0 ) {
-		return -1;
-	}
-
-	if (LOBYTE( wsaData.wVersion ) != 2 ||
-		HIBYTE( wsaData.wVersion ) != 2)
-	{
-		WSACleanup();
-		return -1;
-	}
-#endif /* WIN32 */
-
-#ifdef HAVE_NPCAP
-	if (!LoadNpcapDlls())
-		return -1;
-#endif
-
-	memset(opts.md5_password_digest, 0, kMD5_digest_size);
-	memset(opts.sha512_password_digest, 0, kSHA512_digest_size);
-
-	/* The seq_expiry_tbl is used to prevent the remote ends from prematurely
-	 * re-using a sequence number.
-	 */
-	seq_expiry_tbl = (time_t *) calloc(65536, sizeof(time_t));
-
-	/* Parse options */
-	if (parse_options(argc, argv))
-		return -1;
-
-	/* Init ptunnel RNG */
-	pt_random();
-
-	if (opts.list_pcap_devices) {
-#ifdef HAVE_PCAP
-		print_pcap_devices();
-		return 0;
-#else
-		pt_log(kLog_error, "Pcap not available!\n");
-		return 1;
-#endif
-	}
-
-#ifdef HAVE_PCAP
-	if (opts.pcap && opts.udp) {
-		pt_log(kLog_error, "Packet capture is not supported (or needed) when using UDP for transport.\n");
-		opts.pcap = 0;
-	}
-#ifdef WIN32
-	if (!opts.pcap && !opts.udp) {
-		pt_log(kLog_info, "Running ptunnel-ng on Windows in ICMP mode without WinPcap/Npcap enabled is not supported and may not work!\n");
-        pt_log(kLog_info, "If you encounter problems, install WinPCAP/Npcap from:\n");
-		pt_log(kLog_info, "https://www.winpcap.org/install/default.htm or Npcap for WIN10: https://nmap.org/npcap/windows-10.html\n");
-		pt_log(kLog_info, "After WinPCAP is installed, you can list pcap devices with: --list-pcap-devices\n");
-	}
-#endif
-#endif
-	pt_log(kLog_info, "Starting %s.\n", PACKAGE_STRING);
-	pt_log(kLog_info, "(c) 2004-2011 Daniel Stoedle, <daniels@cs.uit.no>\n");
-	pt_log(kLog_info, "(c) 2017-2019 Toni Uhlig,     <matzeton@googlemail.com>\n");
-#ifdef WIN32
-	pt_log(kLog_info, "Windows version by Mike Miller, <mike@mikeage.net>\n");
-#else
-	pt_log(kLog_info, "Security features by Sebastien Raveau, <sebastien.raveau@epita.fr>\n");
-#endif
-	pt_log(kLog_info, "%s.\n", (opts.mode == kMode_forward ? "Relaying packets from incoming TCP streams" :
-	                                                         "Forwarding incoming ping packets over TCP"));
-	if (opts.udp)
-		pt_log(kLog_info, "UDP transport enabled.\n");
-
-	pt_log(kLog_debug, "Destination at %s:%u\n", opts.given_dst_hostname, opts.given_dst_port);
-
-	/* TODO: Maybe give the user the opportunity to bind to certain addresses e.g. 127.0.0.1 ? */
-	if (opts.mode == kMode_forward)
-		pt_log(kLog_debug, "Listen for incoming connections at 0.0.0.0:%u\n", opts.tcp_listen_port);
-
-#ifndef WIN32
-  	signal(SIGPIPE, SIG_IGN);
-	if (opts.use_syslog) {
-		if (opts.log_file != stdout) {
-			pt_log(kLog_error, "Logging using syslog overrides the use of a specified logfile (using -f).\n");
-			fclose(opts.log_file);
-			opts.log_file = stdout;
-		}
-		openlog("ptunnel", LOG_PID, LOG_USER);
-	}
-	if (opts.chroot) {
-		pt_log(kLog_info, "Restricting file access to %s\n", opts.root_dir);
-		if (-1 == chdir(opts.root_dir) || -1 == chroot(".") || -1 == chdir("/")) {
-			pt_log(kLog_error, "chdir/chroot `%s': %s\n", opts.root_dir, strerror(errno));
-			exit(1);
-		}
-	}
-	if (opts.daemonize) {
-		pt_log(kLog_info, "Going to the background.\n");
-		if (0 < (pid = fork()))
-			exit(0);
-		if (0 > pid)
-			pt_log(kLog_error, "fork: %s\n", strerror(errno));
-		else
-			if (-1 == setsid())
-				pt_log(kLog_error, "setsid: %s\n", strerror(errno));
-			else {
-				if (0 < (pid = fork()))
-					exit(0);
-				if (0 > pid)
-					pt_log(kLog_error, "fork: %s\n", strerror(errno));
-				else {
-					if (NULL != opts.pid_file) {
-						fprintf(opts.pid_file, "%d\n", getpid());
-						fclose(opts.pid_file);
-					}
-					if (! freopen("/dev/null", "r", stdin) ||
-					    ! freopen("/dev/null", "w", stdout) ||
-					    ! freopen("/dev/null", "w", stderr))
-						pt_log(kLog_error, "freopen `%s': %s\n", "/dev/null", strerror(errno));
-				}
-			}
-	}
-#endif /* !WIN32 */
-
-	pthread_mutex_init(&chain_lock, 0);
-	pthread_mutex_init(&num_threads_lock, 0);
-
-	//	Check mode, validate arguments and start either client or proxy.
-	if (opts.mode == kMode_forward) {
-		if (!opts.given_proxy_ip || !opts.given_dst_ip || !opts.given_dst_port || !opts.tcp_listen_port) {
-			printf("One of the options are missing or invalid.\n");
-			print_usage(argv[0]);
-			return -1;
-		}
-		pt_forwarder();
-	}
-	else
-		pt_proxy(0);
-
-#ifdef WIN32
-	WSACleanup();
-#else
-	if (opts.root_dir)
-		free(opts.root_dir);
-#ifdef HAVE_SELINUX
-	if (NULL != opts.selinux_context)
-		free(opts.selinux_context);
-#endif
-#endif /* WIN32 */
-
-	pt_log(kLog_info, "ptunnel is exiting.\n");
-	return 0;
-}
-
-/**	pt_forwarder:
- * Sets up a listening TCP socket, and forwards incoming connections
- * over ping packets.
- */
-void pt_forwarder(void) {
-	int                 server_sock, new_sock, sock, yes = 1;
-	fd_set              set;
-	struct timeval      time;
-	struct sockaddr_in  addr, dest_addr;
-	socklen_t           addr_len;
-	pthread_t           pid;
-	uint16_t            rand_id;
-	struct in_addr      in_addr;
-
-	pt_log(kLog_debug, "Starting forwarder..\n");
-	/** Open our listening socket */
-	sock = socket(AF_INET, SOCK_STREAM, 0);
-	if (sock < 0) {
-		pt_log(kLog_error, "Failed to create socket: %s\n", strerror(errno));
-		return;
-	}
-	if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (const void *) &yes, sizeof(int)) == -1) {
-		pt_log(kLog_error, "Failed to set SO_REUSEADDR option on listening socket: %s\n", strerror(errno));
-		close(sock);
-		return;
-	}
-	addr.sin_family      = AF_INET;
-	addr.sin_port        = htons(opts.tcp_listen_port);
-	addr.sin_addr.s_addr = INADDR_ANY;
-	memset(&(addr.sin_zero), 0, 8);
-	if (bind(sock, (struct sockaddr*)&addr, sizeof(struct sockaddr)) == -1) {
-		pt_log(kLog_error, "Failed to bind listening socket to port %u: %s\n", opts.tcp_listen_port, strerror(errno));
-		close(sock);
-		return;
-	}
-	server_sock	= sock;
-	/* Fill out address structure */
-	memset(&dest_addr, 0, sizeof(struct sockaddr_in));
-	dest_addr.sin_family      = AF_INET;
-	if (opts.udp)
-		dest_addr.sin_port    = htons(kDNS_port /* dns port.. */);
-	else
-		dest_addr.sin_port    = 0;
-	in_addr.s_addr = opts.given_proxy_ip;
-	dest_addr.sin_addr.s_addr = opts.given_proxy_ip;
-	pt_log(kLog_verbose, "Proxy IP address: %s\n", inet_ntoa(in_addr));
-
-	listen(server_sock, 10);
-	while (1) {
-		FD_ZERO(&set);
-		FD_SET(server_sock, &set);
-		time.tv_sec		= 1;
-		time.tv_usec	= 0;
-		if (select(server_sock+1, &set, 0, 0, &time) > 0) {
-			pt_log(kLog_info, "Incoming connection.\n");
-			addr_len	= sizeof(struct sockaddr_in);
-			new_sock	= accept(server_sock, (struct sockaddr*)&addr, &addr_len);
-			if (new_sock < 0) {
-				pt_log(kLog_error, "Accepting incoming connection failed.\n");
-				continue;
-			}
-			pthread_mutex_lock(&num_threads_lock);
-			if (num_threads <= 0) {
-				pt_log(kLog_event, "No running proxy thread - starting it.\n");
-#ifndef WIN32
-				if (pthread_create(&pid, 0, pt_proxy, 0) != 0)
-#else
-				if (0 == (pid = _beginthreadex(0, 0, pt_proxy, 0, 0, 0)))
-#endif
-				{
-					pt_log(kLog_error, "Couldn't create thread! Dropping incoming connection.\n");
-					close(new_sock);
-					pthread_mutex_unlock(&num_threads_lock);
-					continue;
-				}
-			}
-			addr	= dest_addr;
-			rand_id	= pt_random();
-			create_and_insert_proxy_desc(rand_id, rand_id, new_sock, &addr, opts.given_dst_ip, opts.given_dst_port, kProxy_start, kUser_flag);
-			pthread_mutex_unlock(&num_threads_lock);
-		}
-	}
-}
-
-
-int pt_create_udp_socket(int port) {
-	struct sockaddr_in addr; 
-	int                sock, yes = 1;
-
-	sock = socket(AF_INET, SOCK_DGRAM, 0);
-	if (sock < 0) {
-		pt_log(kLog_error, "Failed to set create UDP socket..\n");
-		return 0; 
-	}
-	if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (const void*)&yes, sizeof(int)) < 0) {
-		pt_log(kLog_error, "Failed to set UDP REUSEADDR socket option. (Not fatal, hopefully.)\n");
-		close(sock);
-		return 0;
-	}
-#ifdef SO_REUSEPORT
-	yes = 1;
-	if (setsockopt(sock, SOL_SOCKET, SO_REUSEPORT, (const void*)&yes, sizeof(int)) < 0)
-		pt_log(kLog_error, "Failed to set UDP REUSEPORT socket option. (Not fatal, hopefully.)\n");
-#endif /* SO_REUSEPORT */
-
-	memset(&addr, 0, sizeof(struct sockaddr_in));
-	addr.sin_family			= AF_INET;
-	addr.sin_addr.s_addr	= htonl(INADDR_ANY);
-	addr.sin_port			= htons(port);
-	if (bind(sock, (struct sockaddr*) &addr, sizeof(struct sockaddr_in)) < 0) {
-		pt_log(kLog_error, "Failed to bind UDP socket to port %d (try running as root).\n", port);
-		close(sock);
-		return 0;
-	}
-	return sock;
-}
-
-/* pt_proxy: This function does all the client and proxy stuff.
- */
-#ifndef WIN32
-void * pt_proxy(void *args)
-#else
-unsigned int __stdcall pt_proxy(void *args)
-#endif
+int main(void)
 {
-	(void) args;
-
-	fd_set             set;
-	struct timeval     timeout;
-	int                bytes;
-	struct sockaddr_in addr;
-	socklen_t          addr_len;
-	int                fwd_sock = 0,
-	                   max_sock = 0,
-	                   idx;
-	char               *buf;
-	double             now, last_status_update = 0.0;
-	proxy_desc_t       *cur, *prev, *tmp;
-#ifdef HAVE_PCAP
-	pcap_info_t        pc;
-	pcap_if_t          *alldevs = 0, *pdev;
-#endif
-	xfer_stats_t       xfer;
-#ifdef HAVE_PCAP
-	ip_packet_t        *pkt;
-	uint32_t           ip;
-	in_addr_t          *adr;
-#endif
-	struct in_addr     in_addr;
-#ifdef HAVE_ICMPFILTER
-	struct icmp_filter filt;
-#endif
-
-	/* Start the thread, initialize protocol and ring states. */
-	pt_log(kLog_debug, "Starting ping proxy..\n");
-	if (opts.udp) {
-		pt_log(kLog_debug, "Creating UDP socket..\n");
-		if (opts.mode == kMode_proxy)
-			fwd_sock	= pt_create_udp_socket(kDNS_port);
-		else
-			fwd_sock	= pt_create_udp_socket(0);
-		if (!fwd_sock) {
-			pt_log(kLog_error, "Failed to create UDP socket.\n");
-			return 0;
-		}
-	}
-	else {
-		if (opts.unprivileged)
-		{
-			pt_log(kLog_debug, "Attempting to create unprivileged ICMP datagram socket..\n");
-			fwd_sock		= socket(AF_INET, SOCK_DGRAM, IPPROTO_ICMP);
-		} else {
-			pt_log(kLog_debug, "Attempting to create privileged ICMP raw socket..\n");
-			fwd_sock		= socket(AF_INET, SOCK_RAW, IPPROTO_ICMP);
-#ifdef HAVE_ICMPFILTER
-			if (opts.mode == kMode_forward)
-				filt.data	= ~(1<<ICMP_ECHOREPLY);
-			else
-				filt.data	= ~(1<<ICMP_ECHO);
-			if (fwd_sock >= 0 &&
-			    setsockopt(fwd_sock, SOL_RAW, ICMP_FILTER, &filt, sizeof filt) == -1)
-			{
-				pt_log(kLog_error, "setockopt for ICMP_FILTER: %s\n", strerror(errno));
-			}
-#endif
-		}
-		if (fwd_sock < 0) {
-			pt_log(kLog_error, "Couldn't create %s socket: %s\n",
-			                   (opts.unprivileged ? "unprivileged datagram" :
-			                                        "privileged raw"), strerror(errno));
-			return 0;
-		}
-	}
-	max_sock			= fwd_sock+1;
-#ifdef HAVE_PCAP
-	if (opts.pcap) {
-		if (opts.udp) {
-			pt_log(kLog_error, "Packet capture is not useful with UDP [should not get here!]!\n");
-			close(fwd_sock);
-			return 0;
-		}
-		if (!opts.unprivileged) {
-			memset(&pc, 0, sizeof(pc));
-			pt_log(kLog_info, "Initializing pcap.\n");
-			pc.pcap_err_buf		= (char *) malloc(PCAP_ERRBUF_SIZE);
-			pc.pcap_data_buf	= (char *) malloc(pcap_buf_size);
-			pc.pcap_desc		= pcap_open_live(opts.pcap_device,
-			                                     pcap_buf_size, 0 /* promiscous */,
-			                                     50 /* ms */, pc.pcap_err_buf);
-			if (pc.pcap_desc) {
-				if (pcap_lookupnet(opts.pcap_device, &pc.netp,
-				                   &pc.netmask, pc.pcap_err_buf) == -1)
-				{
-					pt_log(kLog_error, "pcap error: %s\n", pc.pcap_err_buf);
-					opts.pcap = 0;
-				}
-				in_addr.s_addr = pc.netp;
-				pt_log(kLog_verbose, "Network: %s\n", inet_ntoa(in_addr));
-				in_addr.s_addr = pc.netmask;
-				pt_log(kLog_verbose, "Netmask: %s\n", inet_ntoa(in_addr));
-				if (pcap_compile(pc.pcap_desc, &pc.fp, pcap_filter_program, 0, pc.netp) == -1) {
-					pt_log(kLog_error, "Failed to compile pcap filter program.\n");
-					pcap_close(pc.pcap_desc);
-					opts.pcap = 0;
-				}
-				else if (pcap_setfilter(pc.pcap_desc, &pc.fp) == -1) {
-					pt_log(kLog_error, "Failed to set pcap filter program.\n");
-					pcap_close(pc.pcap_desc);
-					opts.pcap = 0;
-				}
-			}
-			else {
-				pt_log(kLog_error, "pcap error: %s\n", pc.pcap_err_buf);
-				opts.pcap = 0;
-
-				if (pcap_findalldevs(&alldevs, pc.pcap_err_buf) == 0) {
-					idx = 0;
-					pt_log(kLog_error, "Available pcap devices:\n");
-					for (pdev = alldevs; pdev != NULL; pdev = pdev->next) {
-						pt_log(kLog_error, "[%d] \"%s\": \"%s\"\n", ++idx,
-						       pdev->name, (pdev->description ? pdev->description : "UNKNOWN"));
-					}
-					pcap_freealldevs(alldevs);
-				}
-			}
-			pc.pkt_q.head	= 0;
-			pc.pkt_q.tail	= 0;
-			pc.pkt_q.elems	= 0;
-			/* Check if we have succeeded, and free stuff if not */
-			if (!opts.pcap) {
-				pt_log(kLog_error, "There were errors enabling pcap - pcap has been disabled.\n");
-				free(pc.pcap_err_buf);
-				free(pc.pcap_data_buf);
-				return 0;
-			}
-		}
-		else
-			pt_log(kLog_info, "pcap disabled since we're running in unprivileged mode.\n");
-	}
-#endif
-
-	pthread_mutex_lock(&num_threads_lock);
-	num_threads++;
-	pthread_mutex_unlock(&num_threads_lock);
-
-	/* Allocate icmp receive buffer */
-	buf					= (char *) malloc(icmp_receive_buf_len);
-
-	/* Start forwarding :) */
-	pt_log(kLog_info, "Ping proxy is listening in %s mode.\n",
-	                  (opts.unprivileged ? "unprivileged" : "privileged"));
-
-#ifndef WIN32
-#ifdef HAVE_SELINUX
-	if (opts.uid || opts.gid || opts.selinux_context)
-#else
-	if (opts.uid || opts.gid)
-#endif
-		pt_log(kLog_info, "Dropping privileges now.\n");
-	if (opts.gid && -1 == setgid(opts.gid))
-		pt_log(kLog_error, "setgid(%d): %s\n", opts.gid, strerror(errno));
-	if (opts.uid && -1 == setuid(opts.uid))
-		pt_log(kLog_error, "setuid(%d): %s\n", opts.uid, strerror(errno));
-#ifdef HAVE_SELINUX
-	if (opts.selinux) {
-		if (NULL != opts.selinux_context && -1 == setcon(opts.selinux_context))
-			pt_log(kLog_error, "setcon(%s) failed: %s\n", opts.selinux_context, strerror(errno));
-	}
-#endif
-#endif
-
-	while (1) {
-		FD_ZERO(&set);
-		FD_SET(fwd_sock, &set);
-		max_sock = fwd_sock+1;
-		pthread_mutex_lock(&chain_lock);
-		for (cur = chain; cur; cur = cur->next) {
-			/* Only handle traffic if there is traffic on the socket, we have
-			 * room in our send window AND we either don't use a password, or
-			 * have been authenticated.
-			 */
-			if (cur->sock && cur->send_wait_ack < cur->window_size &&
-			    (!opts.password || cur->authenticated))
-			{
-				FD_SET(cur->sock, &set);
-				if (cur->sock >= max_sock)
-					max_sock = cur->sock+1;
-			}
-		}
-		pthread_mutex_unlock(&chain_lock);
-		timeout.tv_sec  = 0;
-		timeout.tv_usec = 10000;
-		/* Don't care about return val, since we need to check for new states anyway.. */
-		select(max_sock, &set, 0, 0, &timeout);
+    struct psock psock = {};
 
-		pthread_mutex_lock(&chain_lock);
-		for (prev = 0, cur = chain; cur && cur->sock; cur = tmp) {
-			/* Client: If we're starting up, send a message to the remote end saying so,
-			 * causing him to connect to our desired endpoint.
-			 */
-			if (cur->state == kProxy_start) {
-				pt_log(kLog_verbose, "Sending proxy request.\n");
-				cur->last_ack = time_as_double();
-				queue_packet(fwd_sock, cur, NULL, 0, cur->dst_ip, cur->dst_port, cur->state | cur->type_flag);
-				cur->xfer.icmp_out++;
-				cur->state = kProto_data;
-			}
-			if (cur->should_remove) {
-				pt_log(kLog_info, "\nSession statistics:\n");
-				print_statistics(&cur->xfer, 0);
-				pt_log(kLog_info, "\n");
-				tmp	= cur->next;
-				remove_proxy_desc(cur, prev);
-				continue;
-			}
-			/* Handle TCP traffic */
-			if (FD_ISSET(cur->sock, &set)) {
-				bytes = recv(cur->sock, cur->buf, tcp_receive_buf_len, 0);
-				if (bytes <= 0) {
-					pt_log(kLog_info, "Connection closed or lost.\n");
-					tmp	= cur->next;
-					send_termination_msg(cur, fwd_sock);
-					pt_log(kLog_info, "Session statistics:\n");
-					print_statistics(&cur->xfer, 0);
-					remove_proxy_desc(cur, prev);
-					/* No need to update prev */
-					continue;
-				}
-				cur->xfer.bytes_out	+= bytes;
-				cur->xfer.icmp_out++;
-				queue_packet(fwd_sock, cur, cur->buf, bytes, 0, 0, cur->state | cur->type_flag);
-			}
-			prev = cur;
-			tmp  = cur->next;
-		}
-		pthread_mutex_unlock(&chain_lock);
+    if (psock_init(&psock, 16) != 0)
+    {
+        return 1;
+    }
 
-		if (FD_ISSET(fwd_sock, &set)) {
-			/* Handle ping traffic */
-			addr_len = sizeof(struct sockaddr);
-			bytes    = recvfrom(fwd_sock, buf, icmp_receive_buf_len, 0, (struct sockaddr*)&addr, &addr_len);
-			if (bytes < 0) {
-				pt_log(kLog_error, "Error receiving packet on ICMP socket: %s\n", strerror(errno));
-				break;
-			}
-			handle_packet(buf, bytes, 0, &addr, fwd_sock);
-		}
-
-		/* Check for packets needing resend, and figure out if any connections
-		 * should be closed down due to inactivity.
-		 */
-		pthread_mutex_lock(&chain_lock);
-		now = time_as_double();
-		for (cur = chain; cur; cur = cur->next) {
-			in_addr.s_addr = cur->dst_ip;
-			if (cur->last_activity + kAutomatic_close_timeout < now) {
-				pt_log(kLog_info, "Dropping tunnel %u to %s:%u due to inactivity.\n", cur->id_no, inet_ntoa(in_addr), cur->dst_port);
-				cur->should_remove = 1;
-				continue;
-			}
-			if (cur->recv_wait_send && cur->sock)
-				cur->xfer.bytes_in += send_packets(cur->recv_ring, &cur->recv_xfer_idx, &cur->recv_wait_send, &cur->sock, cur->window_size);
-
-			/* Check for any icmp packets requiring resend, and resend _only_ the first packet. */
-			idx	= cur->send_first_ack;
-			if (cur->send_ring[idx].pkt && cur->send_ring[idx].last_resend+cur->resend_interval < now) {
-				pt_log(kLog_debug, "Resending packet with seq-no %d.\n", cur->send_ring[idx].seq_no);
-				cur->send_ring[idx].last_resend   = now;
-				cur->send_ring[idx].pkt->identifier = htons(cur->icmp_id);
-				cur->send_ring[idx].pkt->seq      = htons(cur->ping_seq);
-				cur->ping_seq++;
-				cur->send_ring[idx].pkt->checksum = 0;
-				cur->send_ring[idx].pkt->checksum = htons(calc_icmp_checksum((uint16_t*)cur->send_ring[idx].pkt, cur->send_ring[idx].pkt_len));
-				/* printf("ID: %d\n", htons(cur->send_ring[idx].pkt->identifier)); */
-				sendto(fwd_sock, (const void*)cur->send_ring[idx].pkt, cur->send_ring[idx].pkt_len,
-				       0, (struct sockaddr*)&cur->dest_addr, sizeof(struct sockaddr));
-				cur->xfer.icmp_resent++;
-			}
-			/* Figure out if it's time to send an explicit acknowledgement */
-			if (cur->last_ack+cur->ack_interval < now && cur->send_wait_ack < cur->window_size &&
-			    cur->remote_ack_val+1 != cur->next_remote_seq)
-			{
-				queue_packet(fwd_sock, cur, NULL, 0, cur->dst_ip, cur->dst_port, kProto_ack | cur->type_flag);
-				cur->last_ack = now;
-				cur->xfer.icmp_ack_out++;
-			}
-		}
-		pthread_mutex_unlock(&chain_lock);
-#ifdef HAVE_PCAP
-		if (opts.pcap) {
-			if (pcap_dispatch(pc.pcap_desc, 32, pcap_packet_handler, (u_char*)&pc.pkt_q) > 0) {
-				pqueue_elem_t	*cur;
-				pt_log(kLog_verbose, "pcap captured %d packets - handling them..\n", pc.pkt_q.elems);
-				while (pc.pkt_q.head) {
-					cur                  = pc.pkt_q.head;
-					memset(&addr, 0, sizeof(struct sockaddr));
-					addr.sin_family      = AF_INET;
-					pkt                  = (ip_packet_t*)&cur->data[0];
-					ip                   = pkt->src_ip;
-					adr                  = (in_addr_t*)&ip;
-					addr.sin_addr.s_addr = *adr;
-					handle_packet(cur->data, cur->bytes, 1, &addr, fwd_sock);
-					pc.pkt_q.head        = cur->next;
-					free(cur);
-					pc.pkt_q.elems--;
-				}
-				pc.pkt_q.tail            = 0;
-				pc.pkt_q.head            = 0;
-			}
-		}
-#endif
-		/* Update running statistics, if requested (only once every second) */
-		if (opts.print_stats && opts.mode == kMode_forward && now > last_status_update+1) {
-			pthread_mutex_lock(&chain_lock);
-			memset(&xfer, 0, sizeof(xfer_stats_t));
-			for (cur = chain; cur; cur = cur->next) {
-				xfer.bytes_in		+= cur->xfer.bytes_in;
-				xfer.bytes_out		+= cur->xfer.bytes_out;
-				xfer.icmp_in		+= cur->xfer.icmp_in;
-				xfer.icmp_out		+= cur->xfer.icmp_out;
-				xfer.icmp_resent	+= cur->xfer.icmp_resent;
-			}
-			pthread_mutex_unlock(&chain_lock);
-			print_statistics(&xfer, (opts.log_level >= kLog_verbose ? 0 : 1));
-			last_status_update		= now;
-		}
-	}
-	pt_log(kLog_debug, "Proxy exiting..\n");
-	if (fwd_sock)
-		close(fwd_sock);
-	/* TODO: Clean up the other descs. Not really a priority since there's no
-	 * real way to quit ptunnel in the first place..
-	 */
-	free(buf);
-	pt_log(kLog_debug, "Ping proxy done\n");
-	return 0;
-}
-
-/* print_statistics: Prints transfer statistics for the given xfer block. The
- * is_continuous variable controls the output mode, either printing a new line
- * or overwriting the old line.
- */
-void print_statistics(xfer_stats_t *xfer, int is_continuous) {
-	const double mb   = 1024.0*1024.0;
-	double       loss = 0.0;
-
-	if (xfer->icmp_out > 0)
-		loss = (double)xfer->icmp_resent/(double)xfer->icmp_out;
-
-	if (is_continuous)
-		printf("\r");
-
-	printf("[inf]: I/O: %6.2f/%6.2f mb ICMP I/O/R: %8u/%8u/%8u Loss: %4.1f%%",
-			xfer->bytes_in/mb, xfer->bytes_out/mb, xfer->icmp_in, xfer->icmp_out, xfer->icmp_resent, loss);
-
-	if (!is_continuous)
-		printf("\n");
-	else
-		fflush(stdout);
-}
-
-#ifdef HAVE_PCAP
-/* pcap_packet_handler:
- * This is our callback function handling captured packets. We already know that the packets
- * are ICMP echo or echo-reply messages, so all we need to do is strip off the ethernet header
- * and append it to the queue descriptor (the refcon argument).
- *
- * Ok, the above isn't entirely correct (we can get other ICMP types as well). This function
- * also has problems when it captures packets on the loopback interface. The moral of the
- * story: Don't do ping forwarding over the loopback interface.
- *
- * Also, we currently don't support anything else than ethernet when in pcap mode. The reason
- * is that I haven't read up on yet on how to remove the frame header from the packet..
- */
-void pcap_packet_handler(u_char *refcon, const struct pcap_pkthdr *hdr, const u_char* pkt) {
-	pqueue_t      *q;
-	pqueue_elem_t *elem;
-	ip_packet_t   *ip;
-
-	/* pt_log(kLog_verbose, "Packet handler: %d =? %d\n", hdr->caplen, hdr->len); */
-	q    = (pqueue_t*)refcon;
-	elem = (pqueue_elem_t *) malloc(sizeof(pqueue_elem_t)+hdr->caplen-sizeof(struct ether_header));
-	memcpy(elem->data, pkt+sizeof(struct ether_header), hdr->caplen-sizeof(struct ether_header));
-	ip   = (ip_packet_t*)elem->data;
-	/* TODO: Add fragment support */
-	elem->bytes	= ntohs(ip->pkt_len);
-	if (elem->bytes > hdr->caplen-sizeof(struct ether_header)) {
-		pt_log(kLog_error, "Received fragmented packet - unable to reconstruct!\n");
-		pt_log(kLog_error, "This error usually occurs because pcap is used on "
-		                   "devices that are not wlan or ethernet.\n");
-		free(elem);
-		return;
-	}
-	/* elem->bytes = hdr->caplen-sizeof(struct ether_header); */
-	elem->next	= 0;
-	if (q->tail) {
-		q->tail->next = elem;
-		q->tail       = elem;
-	}
-	else {
-		q->head	= elem;
-		q->tail	= elem;
-	}
-	q->elems++;
-}
-#endif
-
-uint16_t calc_icmp_checksum(uint16_t *data, int bytes) {
-	uint32_t sum;
-	int      i;
-
-	sum	= 0;
-	for (i = 0; i < bytes / 2; i++) {
-		/* WARNING; this might be a bug, but might explain why I occasionally
-		 * see buggy checksums.. (added htons, that might be the correct behaviour)
-		 */
-		sum	+= data[i];
-	}
-	sum	= (sum & 0xFFFF) + (sum >> 16);
-	sum	= htons(0xFFFF - sum);
-	return sum;
-}
+    psock_loop(&psock);
 
-/* send_termination_msg: Sends two packets to the remote end, informing it that
- * the tunnel is being closed down.
- */
-void send_termination_msg(proxy_desc_t *cur, int icmp_sock) {
-	size_t i;
-	const size_t max_termination_msgs = 3;
+    psock_free(&psock);
 
-	/* Send packet twice, hoping at least one of them makes it through.. */
-	for (i = 0; i < max_termination_msgs; ++i) {
-		queue_packet(icmp_sock, cur, NULL, 0, cur->dst_ip, cur->dst_port, kProto_close | cur->type_flag);
-	}
-	cur->xfer.icmp_out += max_termination_msgs;
+    return 0;
 }