Add new thread-safe getsrvbyname for MacOS X

Conflicts:
	Makefile
	proxychains.lsm
	src/core.h
	src/libproxychains.c
	src/main.c

.gitignore

@@ -9,3 +9,5 @@
 libtool
 config.*
 stamp-h
+proxychains4
+*.dylib

AUTHORS

@@ -1,5 +1,16 @@
+original code
 N3E7CR34TUR3.
+http://proxychains.sourceforge.net
+netcreature@users.sourceforge.net
 
-web site:	proxychains.sourceforge.net
+main.c, remote-dns, thread safety, bugfixes, build system, cleanups
-email:		netcreature@users.sourceforge.net
+rofl0r.
+https://github.com/rofl0r/proxychains
 
+localnet, bugfixes
+adam hamsik.
+https://github.com/haad/proxychains
+
+localnet-port, bugfixes
+jianing yang.
+https://github.com/jianingy/proxychains

INSTALL

@@ -1,13 +0,0 @@
-ProxyChains ver 3.1 Installation
-=======================
-
-If you have installed other ver of proxychains  "make uninstall" before installing this distribution
-
-unpack the .tar.gz , 'cd' to distribution directory and
-run following commands (as root)
--------------------------------------
-./configure
-make
-make install
--------------------------------------
-that's all

Makefile

@@ -15,7 +15,7 @@ bindir = $(exec_prefix)/bin
 
 SRCS = $(sort $(wildcard src/*.c))
 OBJS = $(SRCS:.c=.o)
-LOBJS = src/core.o src/libproxychains.o
+LOBJS = src/core.o src/common.o src/libproxychains.o
 
 CCFLAGS  = -Wall -O0 -g -std=c99 -D_GNU_SOURCE -pipe -DTHREAD_SAFE -Werror
 LDFLAGS = -shared -fPIC -ldl -lpthread
@@ -37,18 +37,22 @@ ALL_LIBS = $(SHARED_LIBS)
 PXCHAINS = proxychains4
 ALL_TOOLS = $(PXCHAINS)
 
-
 CCFLAGS+=$(USER_CFLAGS) $(MAC_CFLAGS)
-CFLAGS_MAIN=-DLIB_DIR=\"$(libdir)\" -DINSTALL_PREFIX=\"$(prefix)\" -DDLL_NAME=\"$(LDSO_PATHNAME)\"
+LDFLAGS+=$(USER_LDFLAGS) $(MAC_LDFLAGS)
-
+CXXFLAGS+=$(CCFLAGS) $(USER_CFLAGS) $(MAC_CFLAGS)
+CFLAGS_MAIN=-DLIB_DIR=\"$(libdir)\" -DINSTALL_PREFIX=\"$(prefix)\" -DDLL_NAME=\"$(LDSO_PATHNAME)\" -DSYSCONFDIR=\"$(confdir)\"
 
 all: $(ALL_LIBS) $(ALL_TOOLS)
 
 #install: $(ALL_LIBS:lib/%=$(DESTDIR)$(libdir)/%) $(DESTDIR)$(LDSO_PATHNAME)
 install:
-	install $(INSTALL_FLAGS) 755 $(ALL_TOOLS) $(bindir)/
+	install -d $(DESTDIR)/$(bindir) $(DESTDIR)/$(libdir) $(DESTDIR)/$(confdir) $(DESTDIR)/$(includedir)
-	install $(INSTALL_FLAGS) 644 $(ALL_LIBS) $(libdir)/
+	install $(INSTALL_FLAGS) 755 $(ALL_TOOLS) $(DESTDIR)/$(bindir)/
-	install $(INSTALL_FLAGS) 644 src/proxychains.conf $(prefix)/etc/
+	install $(INSTALL_FLAGS) 644 $(ALL_LIBS) $(DESTDIR)/$(libdir)/
+
+install-config:
+	install -d $(DESTDIR)/$(confdir)
+	install $(INSTALL_FLAGS) 644 src/proxychains.conf $(DESTDIR)/$(confdir)/
 
 clean:
 	rm -f $(ALL_LIBS)
@@ -62,7 +66,6 @@ $(LDSO_PATHNAME): $(LOBJS)
 	$(CC) $(LDFLAGS) $(LD_SET_SONAME)$(LDSO_PATHNAME) -o $@ $(LOBJS)
 
 $(ALL_TOOLS): $(OBJS)
-	$(CC) src/main.o -o $(PXCHAINS)
+	$(CC) src/main.o src/common.o -o $(PXCHAINS)
 
-
+.PHONY: all clean install install-config
-.PHONY: all clean install

README

@@ -1,23 +1,43 @@
 ProxyChains ver 4.0 README
 ==========================
 
+  ProxyChains is a UNIX program, that hooks network-related libc functions
+  in dynamically linked programs via a preloaded DLL and redirects the
+  connections through SOCKS4a/5 or HTTP proxies.
+
 *********** ATTENTION ***********
 
-this program works only on dynamically linked programs.
+  this program works only on dynamically linked programs.
-also both proxychains and the program to call must use
+  also both proxychains and the program to call must use
-the same dynamic linker (i.e. same libc)
+  the same dynamic linker (i.e. same libc)
 
 *********************************
 
+*** Known limitations of the current version: ***
 
-This is Unix version only.
+  when a process forks, does a DNS lookup in the child, and then uses
+  the ip in the parent, the corresponding ip mapping will not be found.
+  this is because the fork can't write back into the parents mapping table.
+  IRSSI shows this behaviour, so you have to pass the resolved ip address
+  to it. (you can use the proxyresolv script (requires "dig") to do so)
 
-How to mess with sources - How to Install : read INSTALL !!!!!!
+  this means that you can't currently use tor onion urls for irssi.
+  to solve this issue, an external data store (file, pipe, ...) has to
+  manage the dns <-> ip mapping. of course there has to be proper locking.
+  shm_open, mkstemp, are possible candidates for a file based approach,
+  the other option is to spawn some kind of server process that manages the
+  map lookups. since connect() etc are hooked, this must not be a TCP server.
 
-This program forces any tcp connection made by any given tcp client
+  I am reluctant on doing this change, because the described behaviour
-to follow through proxy (or proxy chain). It is a kind of proxifier.
+  seems pretty idiotic (doing a fork only for a DNS lookup), and irssi
-It acts like sockscap / permeo / eborder driver ( intercepts TCP calls )
+  is currently the only known affected program.
-It is FREE.
+
+*** Installation ***
+
+  # needs a working C compiler, preferably gcc
+  ./configure
+  make
+  sudo make install
 
 Changelog:
 ----------
@@ -74,21 +94,21 @@ proxychains looks for config file in following order:
 
 Usage Example:
 
-	bash$ proxychains telnet targethost.com
+	$ proxychains telnet targethost.com
 
 in this example it will run telnet through proxy(or chained proxies)
 specified by proxychains.conf
 
 Usage Example:
 
-      	bash$ proxychains -f /etc/proxychains-other.conf targethost2.com
+      	$ proxychains -f /etc/proxychains-other.conf targethost2.com
 
 in this example it will use different configuration file then proxychains.conf 
 to connect to targethost2.com host.
 
 Usage Example:
 
-	bash$ proxyresolv targethost.com
+	$ proxyresolv targethost.com
 
 in this example it will resolve targethost.com through proxy(or chained proxies)
 specified by proxychains.conf

configure

@@ -2,6 +2,18 @@
 
 prefix=/usr/local
 
+usage() {
+	echo "supported arguments"
+	echo "--prefix=/path 		default: $prefix"
+	echo "--exec_prefix=/path	default: $prefix/bin"
+	echo "--bindir=/path		default: $prefix/bin"
+	echo "--libdir=/path		default: $prefix/lib"
+	echo "--includedir=/path	default: $prefix/include"
+	echo "--sysconfdir=/path	default: $prefix/etc"
+	echo "--help : show this text"
+	exit 1
+}
+
 spliteq() {
 	arg=$1
 	echo "${arg#*=}"
@@ -11,11 +23,13 @@ spliteq() {
 
 parsearg() {
 	case "$1" in
-	--prefix=*) prefix=$(spliteq "$1");;
+	--prefix=*) prefix=`spliteq $1`;;
 	--exec_prefix=*) exec_prefix=`spliteq $1`;;
 	--bindir=*) bindir=`spliteq $1`;;
 	--libdir=*) libdir=`spliteq $1`;;
 	--includedir=*) includedir=`spliteq $1`;;
+	--sysconfdir=*) sysconfdir=`spliteq $1`;;
+	--help) usage;;
 	esac
 }
 
@@ -30,23 +44,27 @@ while true ; do
 	esac
 done
 
-if [ ! $exec_prefix ] ; then
+if [ -z "$exec_prefix" ] ; then
 	exec_prefix=$prefix
 fi
 
-if [ ! $libdir ] ; then
+if [ -z "$libdir" ] ; then
 	libdir=$prefix/lib
 fi
 
-if [ ! $includedir ] ; then
+if [ -z "$includedir" ] ; then
 	includedir=$prefix/include
 fi
 
-if [ ! $bindir ] ; then
+if [ -z "$sysconfdir" ] ; then
+	sysconfdir=$prefix/etc
+fi
+
+if [ -z "$bindir" ] ; then
 	bindir=$exec_prefix/bin
 fi
 
-if [ ! $CC ] ; then
+if [ -z "$CC" ] ; then
 	CC=cc
 fi
 
@@ -58,9 +76,11 @@ echo exec_prefix=$exec_prefix>>config.mak
 echo bindir=$bindir>>config.mak
 echo libdir=$libdir>>config.mak
 echo includedir=$includedir>>config.mak
+echo sysconfdir=$sysconfdir>>config.mak
 if ismac ; then
 	echo LDSO_SUFFIX=dylib>>config.mak
 	echo MAC_CFLAGS+=-DIS_MAC=1 -arch x86_64 -arch i386 >>config.mak
+	echo MAC_LDFLAGS+=-arch x86_64 -arch i386 >>config.mak
 	echo LD_SET_SONAME=-Wl,-install_name,>>config.mak
 	echo INSTALL_FLAGS=-m>>config.mak
 fi

proxychains.lsm

@@ -1,11 +1,11 @@
 Begin3
 Title:          ProxyChains
-Version:        3.0
+Version:        4.0
 Entered-date:
 Description:
 Keywords:
 Author:          <N37CR347UR3>
-Maintained-by:   <NetCreature>
+Maintained-by:   <haad@netbsd.org>
 Primary-site:
 Home-page:      http://proxychains.sourceforge.net
 Original-site:

src/common.c

@@ -0,0 +1,50 @@
+#include "common.h"
+#include <stdlib.h>
+#include <unistd.h>
+#include <stdio.h>
+
+static int check_path(char *path) {
+	if(!path)
+		return 0;
+	return access(path, R_OK) != -1;
+}
+
+char *get_config_path(char* default_path, char* pbuf, size_t bufsize) {
+	char buf[512];
+	// top priority: user defined path
+	char *path = default_path;
+	if(check_path(path))
+		return path;
+
+	// priority 1: env var PROXYCHAINS_CONF_FILE
+	path = getenv(PROXYCHAINS_CONF_FILE_ENV_VAR);
+	if(check_path(path))
+		return path;
+
+	// priority 2; proxychains conf in actual dir
+	path = getcwd(buf, sizeof(buf));
+	snprintf(pbuf, bufsize, "%s/%s", path, PROXYCHAINS_CONF_FILE);
+	path = pbuf;
+	if(check_path(path))
+		return path;
+
+	// priority 3; $HOME/.proxychains/proxychains.conf
+	path = getenv("HOME");
+	snprintf(pbuf, bufsize, "%s/.proxychains/%s", path, PROXYCHAINS_CONF_FILE);
+	path = pbuf;
+	if(check_path(path))
+		return path;
+
+	// priority 4: $SYSCONFDIR/proxychains.conf
+	path = SYSCONFDIR "/" PROXYCHAINS_CONF_FILE;
+	if(check_path(path))
+		return path;
+
+	// priority 5: /etc/proxychains.conf
+	path = "/etc/" PROXYCHAINS_CONF_FILE;
+	if(check_path(path))
+		return path;
+
+	perror("couldnt find configuration file");
+	exit(1);
+}

src/common.h

@@ -2,3 +2,7 @@
 #define PROXYCHAINS_QUIET_MODE_ENV_VAR "PROXYCHAINS_QUIET_MODE"
 #define PROXYCHAINS_CONF_FILE "proxychains.conf"
 #define LOG_PREFIX "[proxychains] "
+
+#include <stddef.h>
+
+char *get_config_path(char* default_path, char* pbuf, size_t bufsize);

src/core.c

@@ -33,6 +33,11 @@
 #include <time.h>
 #include <sys/time.h>
 #include <stdarg.h>
+#include <assert.h>
+#ifdef THREAD_SAFE
+#include <pthread.h>
+pthread_mutex_t internal_ips_lock;
+#endif
 
 #include "core.h"
 #include "common.h"
@@ -147,21 +152,16 @@ static void encode_base_64(char *src, char *dest, int max_len) {
 	*dest++ = 0;
 }
 
-#define LOG_BUFF 1024*20
+void proxychains_write_log(char *str, ...) {
-
+	char buff[1024*20];
-int proxychains_write_log(char *str, ...) {
-	char buff[LOG_BUFF];
 	va_list arglist;
-	FILE *log_file;
-	log_file = stderr;
 	if(!proxychains_quiet_mode) {
 		va_start(arglist, str);
-		vsprintf(buff, str, arglist);
+		vsnprintf(buff, sizeof(buff), str, arglist);
 		va_end(arglist);
-		fprintf(log_file, "%s", buff);
+		fprintf(stderr, "%s", buff);
-		fflush(log_file);
+		fflush(stderr);
 	}
-	return EXIT_SUCCESS;
 }
 
 static int write_n_bytes(int fd, char *buff, size_t size) {
@@ -202,26 +202,15 @@ static int timed_connect(int sock, const struct sockaddr *addr, socklen_t len) {
 	pfd[0].events = POLLOUT;
 	fcntl(sock, F_SETFL, O_NONBLOCK);
 	ret = true_connect(sock, addr, len);
-#ifdef DEBUG
+	PDEBUG("\nconnect ret=%d\n", ret);
-	if(ret == -1)
-		perror("true_connect");
-	printf("\nconnect ret=%d\n", ret);
 	
-	fflush(stdout);
-#endif
 	if(ret == -1 && errno == EINPROGRESS) {
 		ret = poll_retry(pfd, 1, tcp_connect_time_out);
-#ifdef DEBUG
+		PDEBUG("\npoll ret=%d\n", ret);
-		printf("\npoll ret=%d\n", ret);
-		fflush(stdout);
-#endif
 		if(ret == 1) {
 			value_len = sizeof(socklen_t);
 			getsockopt(sock, SOL_SOCKET, SO_ERROR, &value, &value_len);
-#ifdef DEBUG
+			PDEBUG("\nvalue=%d\n", value);
-			printf("\nvalue=%d\n", value);
-			fflush(stdout);
-#endif
 			if(!value)
 				ret = 0;
 			else
@@ -230,6 +219,10 @@ static int timed_connect(int sock, const struct sockaddr *addr, socklen_t len) {
 			ret = -1;
 		}
 	} else {
+#ifdef DEBUG
+		if(ret == -1)
+			perror("true_connect");
+#endif
 		if(ret != 0)
 			ret = -1;
 	}
@@ -261,6 +254,8 @@ static int tunnel_to(int sock, ip_type ip, unsigned short port, proxy_type pt, c
 			goto err;
 	}
 	
+	PDEBUG("host dns %s\n", dns_name ? dns_name : "<NULL>");
+
 	size_t ulen = strlen(user);
 	size_t passlen = strlen(pass);
 
@@ -272,7 +267,6 @@ static int tunnel_to(int sock, ip_type ip, unsigned short port, proxy_type pt, c
 	int len;
 	unsigned char buff[BUFF_SIZE];
 	char ip_buf[16];
-	
 	//memset (buff, 0, sizeof(buff));
 
 	switch (pt) {
@@ -597,7 +591,7 @@ static int chain_step(int ns, proxy_data * pfrom, proxy_data * pto) {
 			break;
 		case SOCKET_ERROR:
 			pto->ps = DOWN_STATE;
-			proxychains_write_log("<--timeout\n");
+			proxychains_write_log("<--socket error or timeout!\n");
 			close(ns);
 			break;
 	}
@@ -719,14 +713,9 @@ int connect_proxy_chain(int sock, ip_type target_ip,
 	return -1;
 }
 
-// TODO: all those buffers aren't threadsafe, but since no memory allocation happens there shouldnt be any segfaults
-static struct hostent hostent_space;
-static in_addr_t resolved_addr;
-static char *resolved_addr_p[2];
-static char addr_name[1024 * 8];
 static const ip_type local_host = { {127, 0, 0, 1} };
 
-struct hostent *proxy_gethostbyname(const char *name) {
+struct hostent *proxy_gethostbyname(const char *name, struct gethostbyname_data* data) {
 	char buff[256];
 	uint32_t i, hash;
 	// yep, new_mem never gets freed. once you passed a fake ip to the client, you can't "retreat" it
@@ -734,18 +723,20 @@ struct hostent *proxy_gethostbyname(const char *name) {
 	size_t l;
 	struct hostent *hp;
 
-	resolved_addr_p[0] = (char *) &resolved_addr;
+	data->resolved_addr_p[0] = (char *) &data->resolved_addr;
-	resolved_addr_p[1] = NULL;
+	data->resolved_addr_p[1] = NULL;
-	hostent_space.h_addr_list = resolved_addr_p;
+
-	resolved_addr = 0;
+	data->hostent_space.h_addr_list = data->resolved_addr_p;
+
+	data->resolved_addr = 0;
 
 	gethostname(buff, sizeof(buff));
 
 	if(!strcmp(buff, name)) {
-		resolved_addr = inet_addr(buff);
+		data->resolved_addr = inet_addr(buff);
-		if(resolved_addr == (in_addr_t) (-1))
+		if(data->resolved_addr == (in_addr_t) (-1))
-			resolved_addr = (in_addr_t) (local_host.as_int);
+			data->resolved_addr = (in_addr_t) (local_host.as_int);
-		return &hostent_space;
+		return &data->hostent_space;
 	}
 
 	memset(buff, 0, sizeof(buff));
@@ -762,7 +753,7 @@ struct hostent *proxy_gethostbyname(const char *name) {
 	if(internal_ips.counter) {
 		for(i = 0; i < internal_ips.counter; i++) {
 			if(internal_ips.list[i]->hash == hash && !strcmp(name, internal_ips.list[i]->string)) {
-				resolved_addr = make_internal_ip(i);
+				data->resolved_addr = make_internal_ip(i);
 				PDEBUG("got cached ip for %s\n", name);
 				goto have_ip;
 			}
@@ -783,8 +774,8 @@ struct hostent *proxy_gethostbyname(const char *name) {
 		}
 	}
 
-	resolved_addr = make_internal_ip(internal_ips.counter);
+	data->resolved_addr = make_internal_ip(internal_ips.counter);
-	if(resolved_addr == (in_addr_t) - 1)
+	if(data->resolved_addr == (in_addr_t) - 1)
 		goto err_plus_unlock;
 
 	l = strlen(name);
@@ -807,73 +798,103 @@ struct hostent *proxy_gethostbyname(const char *name) {
 
 	MUTEX_UNLOCK(&internal_ips_lock);
 
-	strncpy(addr_name, name, sizeof(addr_name));
+	strncpy(data->addr_name, name, sizeof(data->addr_name));
 
-	hostent_space.h_name = addr_name;
+	data->hostent_space.h_name = data->addr_name;
-	hostent_space.h_length = sizeof(in_addr_t);
+	data->hostent_space.h_length = sizeof(in_addr_t);
-	return &hostent_space;
+	return &data->hostent_space;
 
 	err_plus_unlock:
 	MUTEX_UNLOCK(&internal_ips_lock);
 	return NULL;
 }
-int proxy_getaddrinfo(const char *node, const char *service, const struct addrinfo *hints, struct addrinfo **res) {
-	struct servent *se = NULL;
-	struct hostent *hp = NULL;
 
-	struct sockaddr *sockaddr_space = NULL;
+struct addrinfo_data {
-	struct addrinfo *addrinfo_space = NULL;
+	struct addrinfo addrinfo_space;
+	struct sockaddr sockaddr_space;
+	char addr_name[256];
+};
 
-//      printf("proxy_getaddrinfo node %s service %s\n",node,service);
+void proxy_freeaddrinfo(struct addrinfo *res) {
-	addrinfo_space = malloc(sizeof(struct addrinfo));
+	free(res);
-	if(!addrinfo_space)
+}
-		goto err1;
-	sockaddr_space = malloc(sizeof(struct sockaddr));
-	if(!sockaddr_space)
-		goto err2;
-	memset(sockaddr_space, 0, sizeof(*sockaddr_space));
-	memset(addrinfo_space, 0, sizeof(*addrinfo_space));
-	if(node && !inet_aton(node, &((struct sockaddr_in *) sockaddr_space)->sin_addr)) {
-		hp = proxy_gethostbyname(node);
 
-		if(hp)
+void proxy_getserverbyname(const char * service, struct servent *se_buf,
-			memcpy(&((struct sockaddr_in *) sockaddr_space)->sin_addr,
+	char * buf, size_t buf_len, struct servent **se_result)
-			       *(hp->h_addr_list), sizeof(in_addr_t));
+{
-		else
+
-			goto err3;
+#ifdef __linux__
-	}
+	getservbyname_r(service, NULL, se_buf, buf, buf_len, se_result);
+#endif
+
+#ifdef __APPLE__
+	struct servent *se;
+#ifdef THREAD_SAFE
+	MUTEX_LOCK(&internal_getsrvbyname_lock);
+#endif
 	if(service)
 		se = getservbyname(service, NULL);
+	if (!se)
+		memcpy(se_buf, se, buf_len);
+		*se_result = se_buf;
+#ifdef THREAD_SAFE
+	MUTEX_UNLOCK(&internal_getsrvbyname_lock);
+#endif
 
-	if(!se) {
+#endif
-		((struct sockaddr_in *) sockaddr_space)->sin_port = htons(atoi(service ? : "0"));
+}
-	} else
-		((struct sockaddr_in *) sockaddr_space)->sin_port = se->s_port;
 
-	*res = addrinfo_space;
+
-	(*res)->ai_addr = sockaddr_space;
+int proxy_getaddrinfo(const char *node, const char *service, const struct addrinfo *hints, struct addrinfo **res) {
+	struct gethostbyname_data ghdata;
+	struct addrinfo_data *space;
+	struct servent *se = NULL;
+	struct hostent *hp = NULL;
+	struct servent se_buf;
+	struct addrinfo *p;
+	char buf[1024];
+	int port;
+
+//      printf("proxy_getaddrinfo node %s service %s\n",node,service);
+	space = calloc(1, sizeof(struct addrinfo_data));
+	if(!space) goto err1;
+
+	if(node && !inet_aton(node, &((struct sockaddr_in *) &space->sockaddr_space)->sin_addr)) {
+		hp = proxy_gethostbyname(node, &ghdata);
+		if(hp)
+			memcpy(&((struct sockaddr_in *) &space->sockaddr_space)->sin_addr,
+			       *(hp->h_addr_list), sizeof(in_addr_t));
+		else
+			goto err2;
+	}
+	if(service)
+		proxy_getserverbyname(service, &se_buf, buf, sizeof(buf), &se);
+
+	port = se ? se->s_port : htons(atoi(service ? service : "0"));
+	((struct sockaddr_in *) &space->sockaddr_space)->sin_port = port;
+
+	*res = p = &space->addrinfo_space;
+	assert((size_t)p == (size_t) space);
+
+	p->ai_addr = &space->sockaddr_space;
 	if(node)
-		strcpy(addr_name, node);
+		strncpy(space->addr_name, node, sizeof(space->addr_name));
-	(*res)->ai_canonname = addr_name;
+	p->ai_canonname = space->addr_name;
-	(*res)->ai_next = NULL;
+	p->ai_next = NULL;
-	(*res)->ai_family = sockaddr_space->sa_family = AF_INET;
+	p->ai_family = space->sockaddr_space.sa_family = AF_INET;
-	(*res)->ai_addrlen = sizeof(*sockaddr_space);
+	p->ai_addrlen = sizeof(space->sockaddr_space);
 
-	if (hints != NULL) {
+	if(hints) {
-		(*res)->ai_socktype = hints->ai_socktype;
+		p->ai_socktype = hints->ai_socktype;
-		(*res)->ai_flags = hints->ai_flags;
+		p->ai_flags = hints->ai_flags;
-		(*res)->ai_protocol = hints->ai_protocol;
+		p->ai_protocol = hints->ai_protocol;
 	} else {
-		(*res)->ai_socktype = 0;
+		p->ai_flags = (AI_V4MAPPED | AI_ADDRCONFIG);
-		(*res)->ai_flags = 0;
-		(*res)->ai_protocol = 0;
 	}
 
 	goto out;
-	err3:
-	free(sockaddr_space);
 	err2:
-	free(addrinfo_space);
+	free(space);
 	err1:
 	return 1;
 	out:

src/core.h

@@ -4,10 +4,8 @@
     begin                : Tue May 14 2002
     copyright          :  netcreature (C) 2002
     email                 : netcreature@users.sourceforge.net
- ***************************************************************************/
+ ***************************************************************************
-#include <stdint.h>
+ ***************************************************************************
- /*     GPL */
-/***************************************************************************
  *                                                                         *
  *   This program is free software; you can redistribute it and/or modify  *
  *   it under the terms of the GNU General Public License as published by  *
@@ -15,10 +13,13 @@
  *   (at your option) any later version.                                   *
  *                                                                         *
  ***************************************************************************/
+
+#include <stdint.h>
+
 #ifndef __CORE_HEADER
 #define __CORE_HEADER
 #define BUFF_SIZE 8*1024  // used to read responses from proxies.
-#define     MAX_LOCALNET 1024
+#define     MAX_LOCALNET 64
 
 typedef union {
 	unsigned char octet[4];
@@ -41,6 +42,11 @@ extern internal_ip_lookup_table internal_ips;
 #ifdef THREAD_SAFE
 #include <pthread.h>
 pthread_mutex_t internal_ips_lock;
+
+#ifdef __APPLE__
+pthread_mutex_t internal_getsrvbyname_lock;
+#endif
+
 # define MUTEX_LOCK(x) pthread_mutex_lock(x)
 # define MUTEX_UNLOCK(x) pthread_mutex_unlock(x)
 # define MUTEX_INIT(x,y) pthread_mutex_init(x, y)
@@ -60,7 +66,6 @@ typedef enum {
 	BLOCKED  //  target's port blocked on last proxy in the chain
 } ERR_CODE;
 
-
 typedef enum {
 	HTTP_TYPE,
 	SOCKS4_TYPE,
@@ -99,60 +104,48 @@ typedef struct {
 	char pass[256];
 } proxy_data;
 
-typedef struct {
+int connect_proxy_chain (int sock, ip_type target_ip, unsigned short target_port,
-	proxy_data *pd;
+			 proxy_data * pd, unsigned int proxy_count, chain_type ct,
-	chain_type ct;
+			 unsigned int max_chain );
-	unsigned int proxy_count;
-	int sock;
-	struct sockaddr addr;
-	int flags;
-} thread_arg;
 
-int connect_proxy_chain (
+void proxychains_write_log(char *str, ...);
-	int sock,
-	ip_type target_ip,
-	unsigned short target_port,
-	proxy_data * pd,
-	unsigned int proxy_count,
-	chain_type ct,
-	unsigned int max_chain );
-
-int proxychains_write_log(char *str,...);
-struct hostent* proxy_gethostbyname(const char *name);
 
 typedef int (*connect_t)(int, const struct sockaddr *, socklen_t);
-connect_t true_connect;
-
 typedef struct hostent* (*gethostbyname_t)(const char *);
-gethostbyname_t true_gethostbyname;
-
-typedef int (*getaddrinfo_t)(const char *, const char *,
-		const struct addrinfo *,
-		struct addrinfo **);
-getaddrinfo_t true_getaddrinfo;
-
 typedef int (*freeaddrinfo_t)(struct addrinfo *);
-freeaddrinfo_t true_freeaddrinfo;
-
-typedef int (*getnameinfo_t) (const struct sockaddr *,
-		socklen_t, char *,
-		socklen_t, char *,
-		socklen_t, unsigned int);
-getnameinfo_t true_getnameinfo;
-
 typedef struct hostent *(*gethostbyaddr_t) (const void *, socklen_t, int);
-gethostbyaddr_t true_gethostbyaddr;
+
+typedef int (*getaddrinfo_t)(const char *, const char *, const struct addrinfo *, 
+			     struct addrinfo **);
+
+typedef int (*getnameinfo_t) (const struct sockaddr *, socklen_t, char *, 
+			      socklen_t, char *, socklen_t, int);
+
+
+extern connect_t true_connect;
+extern gethostbyname_t true_gethostbyname;
+extern getaddrinfo_t true_getaddrinfo;
+extern freeaddrinfo_t true_freeaddrinfo;
+extern getnameinfo_t true_getnameinfo;
+extern gethostbyaddr_t true_gethostbyaddr;
+
+struct gethostbyname_data {
+	struct hostent hostent_space;
+	in_addr_t resolved_addr;
+	char *resolved_addr_p[2];
+	char addr_name[1024 * 8];
+};
+
+struct hostent* proxy_gethostbyname(const char *name, struct gethostbyname_data *data);
 
 int proxy_getaddrinfo(const char *node, const char *service, 
-		                const struct addrinfo *hints,
+		      const struct addrinfo *hints, struct addrinfo **res);
-				                struct addrinfo **res);
+void proxy_freeaddrinfo(struct addrinfo *res);
-
-struct hostent* proxy_gethostbyname(const char *name);
 
 #ifdef DEBUG
-# define PDEBUG(fmt, args...) fprintf(stderr,"DEBUG:"fmt, ## args)
+# define PDEBUG(fmt, args...) do { fprintf(stderr,"DEBUG:"fmt, ## args); fflush(stderr); } while(0)
 #else
-# define PDEBUG(fmt, args...)
+# define PDEBUG(fmt, args...) do {} while (0)
 #endif
 
 #endif

src/libproxychains.c

@@ -19,6 +19,7 @@
 #define _GNU_SOURCE
 
 #include <sys/types.h>
+#include <sys/param.h>
 
 #include <dlfcn.h>
 #include <errno.h>
@@ -41,14 +42,20 @@
 #define     SOCKADDR_2(x)     (satosin(x)->sin_addr)
 #define     SOCKPORT(x)     (satosin(x)->sin_port)
 #define     SOCKFAMILY(x)     (satosin(x)->sin_family)
-#define     MAX_CHAIN 30*1024
+#define     MAX_CHAIN 512
+
+connect_t true_connect;
+gethostbyname_t true_gethostbyname;
+getaddrinfo_t true_getaddrinfo;
+freeaddrinfo_t true_freeaddrinfo;
+getnameinfo_t true_getnameinfo;
+gethostbyaddr_t true_gethostbyaddr;
 
 int tcp_read_time_out;
 int tcp_connect_time_out;
 int proxychains_got_chain_data = 0;
 int proxychains_quiet_mode = 0;
 int proxychains_resolver = 0;
-static int init_l = 0;
 
 unsigned int proxychains_proxy_count = 0;
 unsigned int proxychains_max_chain = 1;
@@ -60,87 +67,109 @@ proxy_data proxychains_pd[MAX_CHAIN];
 
 size_t num_localnet_addr = 0;
 
-static inline void get_chain_data(proxy_data * pd, unsigned int *proxy_count, chain_type * ct);
+#ifdef THREAD_SAFE
-static void init_lib(void);
+pthread_once_t init_once = PTHREAD_ONCE_INIT;
+#endif
+static int init_l = 0;
 
-static void init_lib(void) {
+static inline void get_chain_data(proxy_data * pd, unsigned int *proxy_count, chain_type * ct);
+
+static void* load_sym(char* symname, void* proxyfunc) {
+
+	void *funcptr = dlsym(RTLD_NEXT, symname);
+	if(!funcptr) {
+		fprintf(stderr, "Cannot load symbol '%s' %s\n", symname, dlerror());
+		exit(1);
+	} else {
+		PDEBUG("loaded symbol '%s'" " real addr %p  wrapped addr %p\n", symname, funcptr, proxyfunc);
+	}
+	if(funcptr == proxyfunc) {
+		PDEBUG("circular reference detected, aborting!\n");
+		abort();
+	}
+	return funcptr;
+}
+
+#define INIT() init_lib_wrapper(__FUNCTION__)
+
+#define SETUP_SYM(X) do { true_ ## X = load_sym( # X, X ); } while(0)
+
+static void do_init(void) {
 	MUTEX_INIT(&internal_ips_lock, NULL);
+
+#ifdef __APPLE__
+	MUTEX_INIT(&internal_getsrvbyname_lock, NULL);
+#endif
+
 	/* read the config file */
 	get_chain_data(proxychains_pd, &proxychains_proxy_count, &proxychains_ct);
 
 	proxychains_write_log(LOG_PREFIX "DLL init\n");
-
+	SETUP_SYM(connect);
-	true_connect = (connect_t) dlsym(RTLD_NEXT, "connect");
+	SETUP_SYM(gethostbyname);
-
+	SETUP_SYM(getaddrinfo);
-	if(!true_connect) {
+	SETUP_SYM(freeaddrinfo);
-		fprintf(stderr, "Cannot load symbol 'connect' %s\n", dlerror());
+	SETUP_SYM(gethostbyaddr);
-		exit(1);
+	SETUP_SYM(getnameinfo);
-	} else {
-		PDEBUG("loaded symbol 'connect'" " real addr %p  wrapped addr %p\n", true_connect, connect);
-	}
-	if(connect == true_connect) {
-		PDEBUG("circular reference detected, aborting!\n");
-		abort();
-	}
-
-	true_gethostbyname = (gethostbyname_t)
-	    dlsym(RTLD_NEXT, "gethostbyname");
-
-	if(!true_gethostbyname) {
-		fprintf(stderr, "Cannot load symbol 'gethostbyname' %s\n", dlerror());
-		exit(1);
-	} else {
-		PDEBUG("loaded symbol 'gethostbyname'"
-		       " real addr %p  wrapped addr %p\n", true_gethostbyname, gethostbyname);
-	}
-	true_getaddrinfo = (getaddrinfo_t)
-	    dlsym(RTLD_NEXT, "getaddrinfo");
-
-	if(!true_getaddrinfo) {
-		fprintf(stderr, "Cannot load symbol 'getaddrinfo' %s\n", dlerror());
-		exit(1);
-	} else {
-		PDEBUG("loaded symbol 'getaddrinfo'" " real addr %p  wrapped addr %p\n", true_getaddrinfo, getaddrinfo);
-	}
-	true_freeaddrinfo = (freeaddrinfo_t)
-	    dlsym(RTLD_NEXT, "freeaddrinfo");
-
-	if(!true_freeaddrinfo) {
-		fprintf(stderr, "Cannot load symbol 'freeaddrinfo' %s\n", dlerror());
-		exit(1);
-	} else {
-		PDEBUG("loaded symbol 'freeaddrinfo'"
-		       " real addr %p  wrapped addr %p\n", true_freeaddrinfo, freeaddrinfo);
-	}
-	true_gethostbyaddr = (gethostbyaddr_t)
-	    dlsym(RTLD_NEXT, "gethostbyaddr");
-
-	if(!true_gethostbyaddr) {
-		fprintf(stderr, "Cannot load symbol 'gethostbyaddr' %s\n", dlerror());
-		exit(1);
-	} else {
-		PDEBUG("loaded symbol 'gethostbyaddr'"
-		       " real addr %p  wrapped addr %p\n", true_gethostbyaddr, gethostbyaddr);
-	}
-	true_getnameinfo = (getnameinfo_t)
-	    dlsym(RTLD_NEXT, "getnameinfo");
-
-	if(!true_getnameinfo) {
-		fprintf(stderr, "Cannot load symbol 'getnameinfo' %s\n", dlerror());
-		exit(1);
-	} else {
-		PDEBUG("loaded symbol 'getnameinfo'" " real addr %p  wrapped addr %p\n", true_getnameinfo, getnameinfo);
-	}
 	init_l = 1;
 }
 
-static inline void get_chain_data(proxy_data * pd, unsigned int *proxy_count, chain_type * ct) {
+static void init_lib_wrapper(const char* caller) {
+#ifndef DEBUG
+	(void) caller;
+#endif
+#ifndef THREAD_SAFE
+	if(init_l) return;
+	PDEBUG("%s called from %s\n", __FUNCTION__,  caller);
+	do_init();
+#else
+	if(!init_l) PDEBUG("%s called from %s\n", __FUNCTION__,  caller);
+	pthread_once(&init_once, do_init);
+#endif
+}
+
+/* if we use gcc >= 3, we can instruct the dynamic loader
+ * to call init_lib at link time. otherwise it gets loaded
+ * lazily, which has the disadvantage that there's a potential
+ * race condition if 2 threads call it before init_l is set
+ * and PTHREAD support was disabled */
+#if __GNUC__ > 2
+__attribute__((constructor))
+static void gcc_init(void) {
+	INIT();
+}
+#endif
+
+FILE *
+open_config_file() {
+	char home_conf[MAXPATHLEN], prefix_conf[MAXPATHLEN];
+	FILE *file;
+
+	snprintf(home_conf, 256, "%s/.proxychains/proxychains.conf", getenv("HOME"));
+	snprintf(prefix_conf, 256, "%s/etc/proxychains.conf", INSTALL_PREFIX);
+
+	if(!(file = fopen("./proxychains.conf", "r"))) {
+		if(!(file = fopen(home_conf, "r"))) {
+			if(!(file = fopen(prefix_conf, "r"))) {
+				if(!(file = fopen("/etc/proxychains.conf", "r"))) {
+					perror("Can't locate proxychains.conf");
+					exit(1);
+				}
+			}
+		}
+	}
+
+	return file;
+}
+
+/* get configuration from config file */
+static void get_chain_data(proxy_data * pd, unsigned int *proxy_count, chain_type * ct) {
 	int count = 0, port_n = 0, list = 0;
 	char buff[1024], type[1024], host[1024], user[1024];
 	char *env;
 	char local_in_addr_port[32];
 	char local_in_addr[32], local_in_port[32], local_netmask[32];
-	FILE *file;
+	FILE *file = NULL;
 
 	if(proxychains_got_chain_data)
 		return;
@@ -149,22 +178,8 @@ static inline void get_chain_data(proxy_data * pd, unsigned int *proxy_count, ch
 	tcp_read_time_out = 4 * 1000;
 	tcp_connect_time_out = 10 * 1000;
 	*ct = DYNAMIC_TYPE;
-
+	env = get_config_path(getenv(PROXYCHAINS_CONF_FILE_ENV_VAR), buff, sizeof(buff));
-	/*
+	file = fopen(env, "r");
-	 * Get path to configuration file from env this file has priority
-	 * if it's defined.
-	 */
-	env = getenv(PROXYCHAINS_CONF_FILE_ENV_VAR);
-
-	snprintf(buff, 256, "%s/.proxychains/proxychains.conf", getenv("HOME"));
-
-	if(!env || (!(file = fopen(env, "r"))))
-		if(!(file = fopen("./proxychains.conf", "r")))
-			if(!(file = fopen(buff, "r")))
-				if(!(file = fopen("/etc/proxychains.conf", "r"))) {
-					perror("Can't locate proxychains.conf");
-					exit(1);
-				}
 
 	env = getenv(PROXYCHAINS_QUIET_MODE_ENV_VAR);
 	if(env && *env == '1')
@@ -172,7 +187,11 @@ static inline void get_chain_data(proxy_data * pd, unsigned int *proxy_count, ch
 
 	while(fgets(buff, sizeof(buff), file)) {
 		if(buff[0] != '\n' && buff[strspn(buff, " ")] != '#') {
+			/* proxylist has to come last */
 			if(list) {
+				if(count >= MAX_CHAIN)
+					break;
+
 				memset(&pd[count], 0, sizeof(proxy_data));
 
 				pd[count].ps = PLAY_STATE;
@@ -193,8 +212,7 @@ static inline void get_chain_data(proxy_data * pd, unsigned int *proxy_count, ch
 					continue;
 
 				if(pd[count].ip.as_int && port_n && pd[count].ip.as_int != (uint32_t) - 1)
-					if(++count == MAX_CHAIN)
+					count++;
-						break;
 			} else {
 				if(strstr(buff, "[ProxyList]")) {
 					list = 1;
@@ -224,7 +242,7 @@ static inline void get_chain_data(proxy_data * pd, unsigned int *proxy_count, ch
 					memset(local_in_port, 0, sizeof(local_in_port) / sizeof(local_in_port[0]));
 
 					if(sscanf(local_in_addr_port, "%15[^:]:%5s", local_in_addr, local_in_port) < 2) {
-						PDEBUG("added localnet: netaddr=%s, port=%s\n",
+						PDEBUG("added localnet: netaddr=%s, netmask=%s\n",
 						       local_in_addr, local_netmask);
 					} else {
 						PDEBUG("added localnet: netaddr=%s, port=%s, netmask=%s\n",
@@ -275,6 +293,8 @@ static inline void get_chain_data(proxy_data * pd, unsigned int *proxy_count, ch
 	proxychains_got_chain_data = 1;
 }
 
+/*******  HOOK FUNCTIONS  *******/
+
 int connect(int sock, const struct sockaddr *addr, unsigned int len) {
 	int socktype = 0, flags = 0, ret = 0;
 	socklen_t optlen = 0;
@@ -285,9 +305,9 @@ int connect(int sock, const struct sockaddr *addr, unsigned int len) {
 	struct in_addr *p_addr_in;
 	unsigned short port;
 	size_t i;
+	int remote_dns_connect = 0;
 
-	if(!init_l)
+	INIT();
-		init_lib();
 	optlen = sizeof(socktype);
 	getsockopt(sock, SOL_SOCKET, SO_TYPE, &socktype, &optlen);
 	if(!(SOCKFAMILY(*addr) == AF_INET && socktype == SOCK_STREAM))
@@ -302,10 +322,14 @@ int connect(int sock, const struct sockaddr *addr, unsigned int len) {
 	PDEBUG("target: %s\n", inet_ntop(AF_INET, p_addr_in, str, sizeof(str)));
 	PDEBUG("port: %d\n", port);
 #endif
-	for(i = 0; i < num_localnet_addr; i++) {
+
+	// check if connect called from proxydns
+        remote_dns_connect = (ntohl(p_addr_in->s_addr) >> 24 == remote_dns_subnet);
+
+	for(i = 0; i < num_localnet_addr && !remote_dns_connect; i++) {
 		if((localnet_addr[i].in_addr.s_addr & localnet_addr[i].netmask.s_addr)
 		   == (p_addr_in->s_addr & localnet_addr[i].netmask.s_addr)) {
-			if(localnet_addr[i].port || localnet_addr[i].port == port) {
+			if(!localnet_addr[i].port || localnet_addr[i].port == port) {
 				PDEBUG("accessing localnet using true_connect\n");
 				return true_connect(sock, addr, len);
 			}
@@ -329,14 +353,14 @@ int connect(int sock, const struct sockaddr *addr, unsigned int len) {
 	return ret;
 }
 
+static struct gethostbyname_data ghbndata;
 struct hostent *gethostbyname(const char *name) {
-	if(!init_l)
+	INIT();
-		init_lib();
 
 	PDEBUG("gethostbyname: %s\n", name);
 
 	if(proxychains_resolver)
-		return proxy_gethostbyname(name);
+		return proxy_gethostbyname(name, &ghbndata);
 	else
 		return true_gethostbyname(name);
 
@@ -346,8 +370,7 @@ struct hostent *gethostbyname(const char *name) {
 int getaddrinfo(const char *node, const char *service, const struct addrinfo *hints, struct addrinfo **res) {
 	int ret = 0;
 
-	if(!init_l)
+	INIT();
-		init_lib();
 
 	PDEBUG("getaddrinfo: %s %s\n", node, service);
 
@@ -360,19 +383,14 @@ int getaddrinfo(const char *node, const char *service, const struct addrinfo *hi
 }
 
 void freeaddrinfo(struct addrinfo *res) {
-	if(!init_l)
+	INIT();
-		init_lib();
 
 	PDEBUG("freeaddrinfo %p \n", res);
 
 	if(!proxychains_resolver)
 		true_freeaddrinfo(res);
-	else {
+	else
-		if (res != NULL) {
+		proxy_freeaddrinfo(res);
-			free(res->ai_addr);
-			free(res);
-		}
-	}
 	return;
 }
 
@@ -389,8 +407,7 @@ int getnameinfo(const struct sockaddr *sa,
 	char ip_buf[16];
 	int ret = 0;
 
-	if(!init_l)
+	INIT();
-		init_lib();
 
 	PDEBUG("getnameinfo: %s %s\n", host, serv);
 
@@ -413,8 +430,7 @@ struct hostent *gethostbyaddr(const void *addr, socklen_t len, int type) {
 	static char *list[2];
 	static struct hostent he;
 
-	if(!init_l)
+	INIT();
-		init_lib();
 
 	PDEBUG("TODO: proper gethostbyaddr hook\n");
 

src/main.c

@@ -1,12 +1,4 @@
-/***************************************************************************
+/*   (C) 2011, 2012 rofl0r
-                          main.c  -  description
-
-    begin                : Tue May 14 2002
-    copyright            :  netcreature (C) 2002
-    email                : netcreature@users.sourceforge.net
- ***************************************************************************/
- /*     GPL */
-/***************************************************************************
  *                                                                         *
  *   This program is free software; you can redistribute it and/or modify  *
  *   it under the terms of the GNU General Public License as published by  *
@@ -14,6 +6,7 @@
  *   (at your option) any later version.                                   *
  *                                                                         *
  ***************************************************************************/
+
 #undef _POSIX_C_SOURCE
 #define _POSIX_C_SOURCE 200809L
 #undef _XOPEN_SOURCE
@@ -40,12 +33,6 @@ static int usage(char **argv) {
 	return EXIT_FAILURE;
 }
 
-int check_path(char *path) {
-	if(!path)
-		return 0;
-	return access(path, R_OK) != -1;
-}
-
 static const char *dll_name = DLL_NAME;
 
 static char own_dir[256];
@@ -106,46 +93,7 @@ int main(int argc, char *argv[]) {
 		return usage(argv);
 
 	/* check if path of config file has not been passed via command line */
-	if(!path) {
+	path = get_config_path(path, pbuf, sizeof(pbuf));
-		// priority 1: env var PROXYCHAINS_CONF_FILE
-		path = getenv(PROXYCHAINS_CONF_FILE_ENV_VAR);
-
-		if(check_path(path))
-			goto have;
-
-		// priority 2; proxychains conf in actual dir
-		path = getcwd(buf, sizeof(buf));
-		snprintf(pbuf, sizeof(pbuf), "%s/%s", path, PROXYCHAINS_CONF_FILE);
-		path = pbuf;
-
-		if(check_path(path))
-			goto have;
-
-		// priority 3; $HOME/.proxychains/proxychains.conf
-		path = getenv("HOME");
-		snprintf(pbuf, sizeof(pbuf), "%s/.proxychains/%s", path, PROXYCHAINS_CONF_FILE);
-		path = pbuf;
-		if(check_path(path))
-			goto have;
-
-		/* Check for default config file in two locations {install_prefix}/etc /etc */
-		// priority 4: $INSTALL_PREFIX/etc/proxychains.conf
-		snprintf(pbuf, sizeof(pbuf), "%s/etc/%s", INSTALL_PREFIX, PROXYCHAINS_CONF_FILE);
-		path = pbuf;
-		if(check_path(path))
-			goto have;
-
-		// priority 5: /etc/proxychains.conf
-		snprintf(pbuf, sizeof(pbuf), "/etc/%s", PROXYCHAINS_CONF_FILE);
-		path = pbuf;
-		if(check_path(path))
-			goto have;
-		perror("Couldn't find configuration file");
-		return 1;
-	}
-
-	have:
-
 	if(!quiet)
 		fprintf(stderr, LOG_PREFIX "config file found: %s\n", path);
 

src/proxychains

@@ -5,7 +5,7 @@ usage() {
 
 	echo "	usage:"
 	echo "	$0 [hq] [-f config-file] <prog> [args]"
-	echo "		-q make proxychains quite"
+	echo "		-q make proxychains quiet"
 	exit
 }
 

src/proxychains.conf

@@ -1,4 +1,4 @@
-# proxychains.conf  VER 3.1
+# proxychains.conf  VER 4
 #
 #        HTTP, SOCKS4, SOCKS5 tunneling proxifier with DNS.
 #	
@@ -54,6 +54,15 @@ remote_dns_subnet 224
 tcp_read_time_out 15000
 tcp_connect_time_out 8000
 
+# By default enable localnet for loopback address ranges
+# RFC5735 Loopback address range
+localnet 127.0.0.0/255.0.0.0
+# RFC1918 Private Address Ranges
+# localnet 10.0.0.0/255.0.0.0
+# localnet 172.16.0.0/255.240.0.0
+# localnet 192.168.0.0/255.255.0.0
+
+
 # Example for localnet exclusion
 ## Exclude connections to 192.168.1.0/24 with port 80
 # localnet 192.168.1.0:80/255.255.255.0

tests/test_getaddrinfo.c

@@ -0,0 +1,41 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <netdb.h>
+#include <netinet/in.h>
+#include <sys/socket.h>
+ 
+#ifndef   NI_MAXHOST
+#define   NI_MAXHOST 1025
+#endif
+ 
+int main(void) {
+	struct addrinfo *result;
+	struct addrinfo *res;
+	int error;
+	
+	/* resolve the domain name into a list of addresses */
+	error = getaddrinfo("www.example.com", NULL, NULL, &result);
+	if (error != 0)
+	{   
+		fprintf(stderr, "error in getaddrinfo: %s\n", gai_strerror(error));
+		return EXIT_FAILURE;
+	}   
+	
+	/* loop over all returned results and do inverse lookup */
+	for (res = result; res != NULL; res = res->ai_next)
+	{   
+		char hostname[NI_MAXHOST] = "";
+	
+		error = getnameinfo(res->ai_addr, res->ai_addrlen, hostname, NI_MAXHOST, NULL, 0, 0); 
+		if (error != 0)
+		{
+		fprintf(stderr, "error in getnameinfo: %s\n", gai_strerror(error));
+		continue;
+		}
+		if (*hostname != '\0')
+		printf("hostname: %s\n", hostname);
+	}   
+	
+	freeaddrinfo(result);
+	return EXIT_SUCCESS;
+}