proxychains-ng/src/libproxychains.c

939 lines
29 KiB
C

/***************************************************************************
libproxychains.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 *
* the Free Software Foundation; either version 2 of the License, or *
* (at your option) any later version. *
* *
***************************************************************************/
#undef _GNU_SOURCE
#define _GNU_SOURCE
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <limits.h>
#include <ctype.h>
#include <errno.h>
#include <assert.h>
#include <netdb.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <fcntl.h>
#include <dlfcn.h>
#include <pthread.h>
#include "core.h"
#include "common.h"
#include "rdns.h"
#undef satosin
#define satosin(x) ((struct sockaddr_in *) &(x))
#define SOCKADDR(x) (satosin(x)->sin_addr.s_addr)
#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 512
#ifdef IS_SOLARIS
#undef connect
int __xnet_connect(int sock, const struct sockaddr *addr, unsigned int len);
connect_t true___xnet_connect;
#endif
close_t true_close;
close_range_t true_close_range;
connect_t true_connect;
gethostbyname_t true_gethostbyname;
getaddrinfo_t true_getaddrinfo;
freeaddrinfo_t true_freeaddrinfo;
getnameinfo_t true_getnameinfo;
gethostbyaddr_t true_gethostbyaddr;
sendto_t true_sendto;
int tcp_read_time_out;
int tcp_connect_time_out;
chain_type proxychains_ct;
proxy_data proxychains_pd[MAX_CHAIN];
unsigned int proxychains_proxy_count = 0;
unsigned int proxychains_proxy_offset = 0;
int proxychains_got_chain_data = 0;
unsigned int proxychains_max_chain = 1;
int proxychains_quiet_mode = 0;
enum dns_lookup_flavor proxychains_resolver = DNSLF_LIBC;
localaddr_arg localnet_addr[MAX_LOCALNET];
size_t num_localnet_addr = 0;
dnat_arg dnats[MAX_DNAT];
size_t num_dnats = 0;
unsigned int remote_dns_subnet = 224;
pthread_once_t init_once = PTHREAD_ONCE_INIT;
static int init_l = 0;
static void get_chain_data(proxy_data * pd, unsigned int *proxy_count, chain_type * ct);
static void* load_sym(char* symname, void* proxyfunc, int is_mandatory) {
void *funcptr = dlsym(RTLD_NEXT, symname);
if(is_mandatory && !funcptr) {
fprintf(stderr, "Cannot load symbol '%s' %s\n", symname, dlerror());
exit(1);
} else if (!funcptr) {
return funcptr;
} 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__)
#include "allocator_thread.h"
const char *proxychains_get_version(void);
static void setup_hooks(void);
typedef struct {
unsigned int first, last, flags;
} close_range_args_t;
/* If there is some `close` or `close_range` system call before do_init,
we buffer it, and actually execute them in do_init. */
static int close_fds[16];
static int close_fds_cnt = 0;
static close_range_args_t close_range_buffer[16];
static int close_range_buffer_cnt = 0;
static unsigned get_rand_seed(void) {
#ifdef HAVE_CLOCK_GETTIME
struct timespec now;
clock_gettime(CLOCK_REALTIME, &now);
return now.tv_sec ^ now.tv_nsec;
#else
return time(NULL);
#endif
}
static void do_init(void) {
srand(get_rand_seed());
core_initialize();
/* read the config file */
get_chain_data(proxychains_pd, &proxychains_proxy_count, &proxychains_ct);
DUMP_PROXY_CHAIN(proxychains_pd, proxychains_proxy_count);
proxychains_write_log(LOG_PREFIX "DLL init: proxychains-ng %s\n", proxychains_get_version());
setup_hooks();
while(close_fds_cnt) true_close(close_fds[--close_fds_cnt]);
while(close_range_buffer_cnt) {
int i = --close_range_buffer_cnt;
true_close_range(close_range_buffer[i].first, close_range_buffer[i].last, close_range_buffer[i].flags);
}
init_l = 1;
rdns_init(proxychains_resolver);
}
static void init_lib_wrapper(const char* caller) {
#ifndef DEBUG
(void) caller;
#endif
if(!init_l) PDEBUG("%s called from %s\n", __FUNCTION__, caller);
pthread_once(&init_once, do_init);
}
/* 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
typedef enum {
RS_PT_NONE = 0,
RS_PT_SOCKS4,
RS_PT_SOCKS5,
RS_PT_HTTP
} rs_proxyType;
/*
proxy_from_string() taken from rocksock network I/O library (C) rofl0r
valid inputs:
socks5://user:password@proxy.domain.com:port
socks5://proxy.domain.com:port
socks4://proxy.domain.com:port
http://user:password@proxy.domain.com:port
http://proxy.domain.com:port
supplying port number is obligatory.
user:pass@ part is optional for http and socks5.
however, user:pass authentication is currently not implemented for http proxies.
return 1 on success, 0 on error.
*/
static int proxy_from_string(const char *proxystring,
char *type_buf,
char* host_buf,
int *port_n,
char *user_buf,
char* pass_buf)
{
const char* p;
rs_proxyType proxytype;
size_t next_token = 6, ul = 0, pl = 0, hl;
if(!proxystring[0] || !proxystring[1] || !proxystring[2] || !proxystring[3] || !proxystring[4] || !proxystring[5]) goto inv_string;
if(*proxystring == 's') {
switch(proxystring[5]) {
case '5': proxytype = RS_PT_SOCKS5; break;
case '4': proxytype = RS_PT_SOCKS4; break;
default: goto inv_string;
}
} else if(*proxystring == 'h') {
proxytype = RS_PT_HTTP;
next_token = 4;
} else goto inv_string;
if(
proxystring[next_token++] != ':' ||
proxystring[next_token++] != '/' ||
proxystring[next_token++] != '/') goto inv_string;
const char *at = strrchr(proxystring+next_token, '@');
if(at) {
if(proxytype == RS_PT_SOCKS4)
return 0;
p = strchr(proxystring+next_token, ':');
if(!p || p >= at) goto inv_string;
const char *u = proxystring+next_token;
ul = p-u;
p++;
pl = at-p;
if(proxytype == RS_PT_SOCKS5 && (ul > 255 || pl > 255))
return 0;
memcpy(user_buf, u, ul);
user_buf[ul]=0;
memcpy(pass_buf, p, pl);
pass_buf[pl]=0;
next_token += 2+ul+pl;
} else {
user_buf[0]=0;
pass_buf[0]=0;
}
const char* h = proxystring+next_token;
p = strchr(h, ':');
if(!p) goto inv_string;
hl = p-h;
if(hl > 255)
return 0;
memcpy(host_buf, h, hl);
host_buf[hl]=0;
*port_n = atoi(p+1);
switch(proxytype) {
case RS_PT_SOCKS4:
strcpy(type_buf, "socks4");
break;
case RS_PT_SOCKS5:
strcpy(type_buf, "socks5");
break;
case RS_PT_HTTP:
strcpy(type_buf, "http");
break;
default:
return 0;
}
return 1;
inv_string:
return 0;
}
static const char* bool_str(int bool_val) {
if(bool_val) return "true";
return "false";
}
#define STR_STARTSWITH(P, LIT) (!strncmp(P, LIT, sizeof(LIT)-1))
/* 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 buf[1024], type[1024], host[1024], user[1024];
char *buff, *env, *p;
char local_addr_port[64], local_addr[64], local_netmask[32];
char dnat_orig_addr_port[32], dnat_new_addr_port[32];
char dnat_orig_addr[32], dnat_orig_port[32], dnat_new_addr[32], dnat_new_port[32];
char rdnsd_addr[32], rdnsd_port[8];
FILE *file = NULL;
if(proxychains_got_chain_data)
return;
PFUNC();
//Some defaults
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), buf, sizeof(buf));
if( ( file = fopen(env, "r") ) == NULL )
{
perror("couldnt read configuration file");
exit(1);
}
env = getenv(PROXYCHAINS_QUIET_MODE_ENV_VAR);
if(env && *env == '1')
proxychains_quiet_mode = 1;
while(fgets(buf, sizeof(buf), file)) {
buff = buf;
/* remove leading whitespace */
while(isspace(*buff)) buff++;
/* remove trailing '\n' */
if((p = strrchr(buff, '\n'))) *p = 0;
p = buff + strlen(buff)-1;
/* remove trailing whitespace */
while(p >= buff && isspace(*p)) *(p--) = 0;
if(!*buff || *buff == '#') continue; /* skip empty lines and comments */
if(1) {
/* proxylist has to come last */
if(list) {
if(count >= MAX_CHAIN)
break;
memset(&pd[count], 0, sizeof(proxy_data));
pd[count].ps = PLAY_STATE;
port_n = 0;
int ret = sscanf(buff, "%s %s %d %s %s", type, host, &port_n, pd[count].user, pd[count].pass);
if(ret < 3 || ret == EOF) {
if(!proxy_from_string(buff, type, host, &port_n, pd[count].user, pd[count].pass)) {
inv:
fprintf(stderr, "error: invalid item in proxylist section: %s", buff);
exit(1);
}
}
memset(&pd[count].ip, 0, sizeof(pd[count].ip));
pd[count].ip.is_v6 = !!strchr(host, ':');
pd[count].port = htons((unsigned short) port_n);
ip_type* host_ip = &pd[count].ip;
if(1 != inet_pton(host_ip->is_v6 ? AF_INET6 : AF_INET, host, host_ip->addr.v6)) {
if(*ct == STRICT_TYPE && proxychains_resolver >= DNSLF_RDNS_START && count > 0) {
/* we can allow dns hostnames for all but the first proxy in the list if chaintype is strict, as remote lookup can be done */
rdns_init(proxychains_resolver);
ip_type4 internal_ip = at_get_ip_for_host(host, strlen(host));
pd[count].ip.is_v6 = 0;
host_ip->addr.v4 = internal_ip;
if(internal_ip.as_int == IPT4_INVALID.as_int)
goto inv_host;
} else {
inv_host:
fprintf(stderr, "proxy %s has invalid value or is not numeric\n", host);
fprintf(stderr, "non-numeric ips are only allowed under the following circumstances:\n");
fprintf(stderr, "chaintype == strict (%s), proxy is not first in list (%s), proxy_dns active (%s)\n\n", bool_str(*ct == STRICT_TYPE), bool_str(count > 0), rdns_resolver_string(proxychains_resolver));
exit(1);
}
}
if(!strcmp(type, "http")) {
pd[count].pt = HTTP_TYPE;
} else if(!strcmp(type, "raw")) {
pd[count].pt = RAW_TYPE;
} else if(!strcmp(type, "socks4")) {
pd[count].pt = SOCKS4_TYPE;
} else if(!strcmp(type, "socks5")) {
pd[count].pt = SOCKS5_TYPE;
} else
goto inv;
if(port_n)
count++;
} else {
if(!strcmp(buff, "[ProxyList]")) {
list = 1;
} else if(!strcmp(buff, "random_chain")) {
*ct = RANDOM_TYPE;
} else if(!strcmp(buff, "strict_chain")) {
*ct = STRICT_TYPE;
} else if(!strcmp(buff, "dynamic_chain")) {
*ct = DYNAMIC_TYPE;
} else if(!strcmp(buff, "round_robin_chain")) {
*ct = ROUND_ROBIN_TYPE;
} else if(STR_STARTSWITH(buff, "tcp_read_time_out")) {
sscanf(buff, "%s %d", user, &tcp_read_time_out);
} else if(STR_STARTSWITH(buff, "tcp_connect_time_out")) {
sscanf(buff, "%s %d", user, &tcp_connect_time_out);
} else if(STR_STARTSWITH(buff, "remote_dns_subnet")) {
sscanf(buff, "%s %u", user, &remote_dns_subnet);
if(remote_dns_subnet >= 256) {
fprintf(stderr,
"remote_dns_subnet: invalid value. requires a number between 0 and 255.\n");
exit(1);
}
} else if(STR_STARTSWITH(buff, "localnet")) {
char colon, extra, right_bracket[2];
unsigned short local_port = 0, local_prefix;
int local_family, n, valid;
if(sscanf(buff, "%s %53[^/]/%15s%c", user, local_addr_port, local_netmask, &extra) != 3) {
fprintf(stderr, "localnet format error");
exit(1);
}
p = strchr(local_addr_port, ':');
if(!p || p == strrchr(local_addr_port, ':')) {
local_family = AF_INET;
n = sscanf(local_addr_port, "%15[^:]%c%5hu%c", local_addr, &colon, &local_port, &extra);
valid = n == 1 || (n == 3 && colon == ':');
} else if(local_addr_port[0] == '[') {
local_family = AF_INET6;
n = sscanf(local_addr_port, "[%45[^][]%1[]]%c%5hu%c", local_addr, right_bracket, &colon, &local_port, &extra);
valid = n == 2 || (n == 4 && colon == ':');
} else {
local_family = AF_INET6;
valid = sscanf(local_addr_port, "%45[^][]%c", local_addr, &extra) == 1;
}
if(!valid) {
fprintf(stderr, "localnet address or port error\n");
exit(1);
}
if(local_port) {
PDEBUG("added localnet: netaddr=%s, port=%u, netmask=%s\n",
local_addr, local_port, local_netmask);
} else {
PDEBUG("added localnet: netaddr=%s, netmask=%s\n",
local_addr, local_netmask);
}
if(num_localnet_addr < MAX_LOCALNET) {
localnet_addr[num_localnet_addr].family = local_family;
localnet_addr[num_localnet_addr].port = local_port;
valid = 0;
if (local_family == AF_INET) {
valid =
inet_pton(local_family, local_addr,
&localnet_addr[num_localnet_addr].in_addr) > 0;
} else if(local_family == AF_INET6) {
valid =
inet_pton(local_family, local_addr,
&localnet_addr[num_localnet_addr].in6_addr) > 0;
}
if(!valid) {
fprintf(stderr, "localnet address error\n");
exit(1);
}
if(local_family == AF_INET && strchr(local_netmask, '.')) {
valid =
inet_pton(local_family, local_netmask,
&localnet_addr[num_localnet_addr].in_mask) > 0;
} else {
valid = sscanf(local_netmask, "%hu%c", &local_prefix, &extra) == 1;
if (valid) {
if(local_family == AF_INET && local_prefix <= 32) {
localnet_addr[num_localnet_addr].in_mask.s_addr =
htonl(0xFFFFFFFFu << (32u - local_prefix));
} else if(local_family == AF_INET6 && local_prefix <= 128) {
localnet_addr[num_localnet_addr].in6_prefix =
local_prefix;
} else {
valid = 0;
}
}
}
if(!valid) {
fprintf(stderr, "localnet netmask error\n");
exit(1);
}
++num_localnet_addr;
} else {
fprintf(stderr, "# of localnet exceed %d.\n", MAX_LOCALNET);
}
} else if(STR_STARTSWITH(buff, "chain_len")) {
char *pc;
int len;
pc = strchr(buff, '=');
if(!pc) {
fprintf(stderr, "error: missing equals sign '=' in chain_len directive.\n");
exit(1);
}
len = atoi(++pc);
proxychains_max_chain = (len ? len : 1);
} else if(!strcmp(buff, "quiet_mode")) {
proxychains_quiet_mode = 1;
} else if(!strcmp(buff, "proxy_dns_old")) {
proxychains_resolver = DNSLF_FORKEXEC;
} else if(!strcmp(buff, "proxy_dns")) {
proxychains_resolver = DNSLF_RDNS_THREAD;
} else if(STR_STARTSWITH(buff, "proxy_dns_daemon")) {
struct sockaddr_in rdns_server_buffer;
if(sscanf(buff, "%s %15[^:]:%5s", user, rdnsd_addr, rdnsd_port) < 3) {
fprintf(stderr, "proxy_dns_daemon format error\n");
exit(1);
}
rdns_server_buffer.sin_family = AF_INET;
int error = inet_pton(AF_INET, rdnsd_addr, &rdns_server_buffer.sin_addr);
if(error <= 0) {
fprintf(stderr, "bogus proxy_dns_daemon address\n");
exit(1);
}
rdns_server_buffer.sin_port = htons(atoi(rdnsd_port));
proxychains_resolver = DNSLF_RDNS_DAEMON;
rdns_set_daemon(&rdns_server_buffer);
} else if(STR_STARTSWITH(buff, "dnat")) {
if(sscanf(buff, "%s %21[^ ] %21s\n", user, dnat_orig_addr_port, dnat_new_addr_port) < 3) {
fprintf(stderr, "dnat format error");
exit(1);
}
/* clean previously used buffer */
memset(dnat_orig_port, 0, sizeof(dnat_orig_port) / sizeof(dnat_orig_port[0]));
memset(dnat_new_port, 0, sizeof(dnat_new_port) / sizeof(dnat_new_port[0]));
(void)sscanf(dnat_orig_addr_port, "%15[^:]:%5s", dnat_orig_addr, dnat_orig_port);
(void)sscanf(dnat_new_addr_port, "%15[^:]:%5s", dnat_new_addr, dnat_new_port);
if(num_dnats < MAX_DNAT) {
int error;
error =
inet_pton(AF_INET, dnat_orig_addr,
&dnats[num_dnats].orig_dst);
if(error <= 0) {
fprintf(stderr, "dnat original destination address error\n");
exit(1);
}
error =
inet_pton(AF_INET, dnat_new_addr,
&dnats[num_dnats].new_dst);
if(error <= 0) {
fprintf(stderr, "dnat effective destination address error\n");
exit(1);
}
if(dnat_orig_port[0]) {
dnats[num_dnats].orig_port =
(short) atoi(dnat_orig_port);
} else {
dnats[num_dnats].orig_port = 0;
}
if(dnat_new_port[0]) {
dnats[num_dnats].new_port =
(short) atoi(dnat_new_port);
} else {
dnats[num_dnats].new_port = 0;
}
PDEBUG("added dnat: orig-dst=%s orig-port=%d new-dst=%s new-port=%d\n", dnat_orig_addr, dnats[num_dnats].orig_port, dnat_new_addr, dnats[num_dnats].new_port);
++num_dnats;
} else {
fprintf(stderr, "# of dnat exceed %d.\n", MAX_DNAT);
}
}
}
}
}
#ifndef BROKEN_FCLOSE
fclose(file);
#endif
if(!count) {
fprintf(stderr, "error: no valid proxy found in config\n");
exit(1);
}
*proxy_count = count;
proxychains_got_chain_data = 1;
PDEBUG("proxy_dns: %s\n", rdns_resolver_string(proxychains_resolver));
}
/******* HOOK FUNCTIONS *******/
#define EXPAND( args...) args
#ifdef MONTEREY_HOOKING
#define HOOKFUNC(R, N, args...) R pxcng_ ## N ( EXPAND(args) )
#else
#define HOOKFUNC(R, N, args...) R N ( EXPAND(args) )
#endif
HOOKFUNC(int, close, int fd) {
if(!init_l) {
if(close_fds_cnt>=(sizeof close_fds/sizeof close_fds[0])) goto err;
close_fds[close_fds_cnt++] = fd;
errno = 0;
return 0;
}
if(proxychains_resolver != DNSLF_RDNS_THREAD) return true_close(fd);
/* prevent rude programs (like ssh) from closing our pipes */
if(fd != req_pipefd[0] && fd != req_pipefd[1] &&
fd != resp_pipefd[0] && fd != resp_pipefd[1]) {
return true_close(fd);
}
err:
errno = EBADF;
return -1;
}
static int is_v4inv6(const struct in6_addr *a) {
return !memcmp(a->s6_addr, "\0\0\0\0\0\0\0\0\0\0\xff\xff", 12);
}
static int compare_func_int(const void *l, const void *r) {
int arg1 = *(const int*)l;
int arg2 = *(const int*)r;
return (arg1 > arg2) - (arg1 < arg2);
}
/* Warning: Linux manual says the third arg is `unsigned int`, but unistd.h says `int`. */
HOOKFUNC(int, close_range, unsigned first, unsigned last, int flags) {
if(true_close_range == NULL) {
fprintf(stderr, "Calling close_range, but this platform does not provide this system call. ");
return -1;
}
if(!init_l) {
/* push back to cache, and delay the execution. */
if(close_range_buffer_cnt >= (sizeof close_range_buffer / sizeof close_range_buffer[0])) {
errno = ENOMEM;
return -1;
}
int i = close_range_buffer_cnt++;
close_range_buffer[i].first = first;
close_range_buffer[i].last = last;
close_range_buffer[i].flags = flags;
return errno = 0;
}
if(proxychains_resolver != DNSLF_RDNS_THREAD) return true_close_range(first, last, flags);
/* prevent rude programs (like ssh) from closing our pipes */
int res = 0, uerrno = 0, i;
int protected_fds[] = {req_pipefd[0], req_pipefd[1], resp_pipefd[0], resp_pipefd[1]};
int protected_fds_size = sizeof protected_fds / sizeof protected_fds[0];
qsort(protected_fds, protected_fds_size, sizeof protected_fds[0], compare_func_int);
/* We are skipping protected_fds while calling true_close_range()
* If protected_fds cut the range into some sub-ranges, we close sub-ranges BEFORE cut point in the loop.
* [first, cut1-1] , [cut1+1, cut2-1] , [cut2+1, cut3-1]
* Finally, we delete the remaining sub-range, outside the loop. [cut3+1, tail]
*/
int next_fd_to_close = first;
for(i = 0; i < protected_fds_size; ++i) {
if(protected_fds[i] < first || protected_fds[i] > last)
continue;
int prev = (i == 0 || protected_fds[i-1] < first) ? first : protected_fds[i-1]+1;
if(prev != protected_fds[i]) {
if(-1 == true_close_range(prev, protected_fds[i]-1, flags)) {
res = -1;
uerrno = errno;
}
}
next_fd_to_close = protected_fds[i]+1;
}
if(next_fd_to_close <= last) {
if(-1 == true_close_range(next_fd_to_close, last, flags)) {
res = -1;
uerrno = errno;
}
}
errno = uerrno;
return res;
}
HOOKFUNC(int, connect, int sock, const struct sockaddr *addr, unsigned int len) {
INIT();
PFUNC();
int socktype = 0, flags = 0, ret = 0;
socklen_t optlen = 0;
ip_type dest_ip;
DEBUGDECL(char str[256]);
struct in_addr *p_addr_in;
struct in6_addr *p_addr_in6;
dnat_arg *dnat = NULL;
unsigned short port;
size_t i;
int remote_dns_connect = 0;
optlen = sizeof(socktype);
sa_family_t fam = SOCKFAMILY(*addr);
getsockopt(sock, SOL_SOCKET, SO_TYPE, &socktype, &optlen);
if(!((fam == AF_INET || fam == AF_INET6) && socktype == SOCK_STREAM))
return true_connect(sock, addr, len);
int v6 = dest_ip.is_v6 = fam == AF_INET6;
p_addr_in = &((struct sockaddr_in *) addr)->sin_addr;
p_addr_in6 = &((struct sockaddr_in6 *) addr)->sin6_addr;
port = !v6 ? ntohs(((struct sockaddr_in *) addr)->sin_port)
: ntohs(((struct sockaddr_in6 *) addr)->sin6_port);
struct in_addr v4inv6;
if(v6 && is_v4inv6(p_addr_in6)) {
memcpy(&v4inv6.s_addr, &p_addr_in6->s6_addr[12], 4);
v6 = dest_ip.is_v6 = 0;
p_addr_in = &v4inv6;
}
if(!v6 && !memcmp(p_addr_in, "\0\0\0\0", 4)) {
errno = ECONNREFUSED;
return -1;
}
// PDEBUG("localnet: %s; ", inet_ntop(AF_INET,&in_addr_localnet, str, sizeof(str)));
// PDEBUG("netmask: %s; " , inet_ntop(AF_INET, &in_addr_netmask, str, sizeof(str)));
PDEBUG("target: %s\n", inet_ntop(v6 ? AF_INET6 : AF_INET, v6 ? (void*)p_addr_in6 : (void*)p_addr_in, str, sizeof(str)));
PDEBUG("port: %d\n", port);
// check if connect called from proxydns
remote_dns_connect = !v6 && (ntohl(p_addr_in->s_addr) >> 24 == remote_dns_subnet);
// more specific first
if (!v6) for(i = 0; i < num_dnats && !remote_dns_connect && !dnat; i++)
if(dnats[i].orig_dst.s_addr == p_addr_in->s_addr)
if(dnats[i].orig_port && (dnats[i].orig_port == port))
dnat = &dnats[i];
if (!v6) for(i = 0; i < num_dnats && !remote_dns_connect && !dnat; i++)
if(dnats[i].orig_dst.s_addr == p_addr_in->s_addr)
if(!dnats[i].orig_port)
dnat = &dnats[i];
if (dnat) {
p_addr_in = &dnat->new_dst;
if (dnat->new_port)
port = dnat->new_port;
}
for(i = 0; i < num_localnet_addr && !remote_dns_connect; i++) {
if (localnet_addr[i].port && localnet_addr[i].port != port)
continue;
if (localnet_addr[i].family != (v6 ? AF_INET6 : AF_INET))
continue;
if (v6) {
size_t prefix_bytes = localnet_addr[i].in6_prefix / CHAR_BIT;
size_t prefix_bits = localnet_addr[i].in6_prefix % CHAR_BIT;
if (prefix_bytes && memcmp(p_addr_in6->s6_addr, localnet_addr[i].in6_addr.s6_addr, prefix_bytes) != 0)
continue;
if (prefix_bits && (p_addr_in6->s6_addr[prefix_bytes] ^ localnet_addr[i].in6_addr.s6_addr[prefix_bytes]) >> (CHAR_BIT - prefix_bits))
continue;
} else {
if((p_addr_in->s_addr ^ localnet_addr[i].in_addr.s_addr) & localnet_addr[i].in_mask.s_addr)
continue;
}
PDEBUG("accessing localnet using true_connect\n");
return true_connect(sock, addr, len);
}
flags = fcntl(sock, F_GETFL, 0);
if(flags & O_NONBLOCK)
fcntl(sock, F_SETFL, !O_NONBLOCK);
memcpy(dest_ip.addr.v6, v6 ? (void*)p_addr_in6 : (void*)p_addr_in, v6?16:4);
ret = connect_proxy_chain(sock,
dest_ip,
htons(port),
proxychains_pd, proxychains_proxy_count, proxychains_ct, proxychains_max_chain);
fcntl(sock, F_SETFL, flags);
if(ret != SUCCESS)
errno = ECONNREFUSED;
return ret;
}
#ifdef IS_SOLARIS
HOOKFUNC(int, __xnet_connect, int sock, const struct sockaddr *addr, unsigned int len)
return connect(sock, addr, len);
}
#endif
static struct gethostbyname_data ghbndata;
HOOKFUNC(struct hostent*, gethostbyname, const char *name) {
INIT();
PDEBUG("gethostbyname: %s\n", name);
if(proxychains_resolver == DNSLF_FORKEXEC)
return proxy_gethostbyname_old(name);
else if(proxychains_resolver == DNSLF_LIBC)
return true_gethostbyname(name);
else
return proxy_gethostbyname(name, &ghbndata);
return NULL;
}
HOOKFUNC(int, getaddrinfo, const char *node, const char *service, const struct addrinfo *hints, struct addrinfo **res) {
INIT();
PDEBUG("getaddrinfo: %s %s\n", node ? node : "null", service ? service : "null");
if(proxychains_resolver != DNSLF_LIBC)
return proxy_getaddrinfo(node, service, hints, res);
else
return true_getaddrinfo(node, service, hints, res);
}
HOOKFUNC(void, freeaddrinfo, struct addrinfo *res) {
INIT();
PDEBUG("freeaddrinfo %p \n", (void *) res);
if(proxychains_resolver == DNSLF_LIBC)
true_freeaddrinfo(res);
else
proxy_freeaddrinfo(res);
}
HOOKFUNC(int, getnameinfo, const struct sockaddr *sa, socklen_t salen,
char *host, GN_NODELEN_T hostlen, char *serv,
GN_SERVLEN_T servlen, GN_FLAGS_T flags)
{
INIT();
PFUNC();
if(proxychains_resolver == DNSLF_LIBC) {
return true_getnameinfo(sa, salen, host, hostlen, serv, servlen, flags);
} else {
if(!salen || !(SOCKFAMILY(*sa) == AF_INET || SOCKFAMILY(*sa) == AF_INET6))
return EAI_FAMILY;
int v6 = SOCKFAMILY(*sa) == AF_INET6;
if(salen < (v6?sizeof(struct sockaddr_in6):sizeof(struct sockaddr_in)))
return EAI_FAMILY;
if(hostlen) {
unsigned char v4inv6buf[4];
const void *ip = v6 ? (void*)&((struct sockaddr_in6*)sa)->sin6_addr
: (void*)&((struct sockaddr_in*)sa)->sin_addr;
unsigned scopeid = 0;
if(v6) {
if(is_v4inv6(&((struct sockaddr_in6*)sa)->sin6_addr)) {
memcpy(v4inv6buf, &((struct sockaddr_in6*)sa)->sin6_addr.s6_addr[12], 4);
ip = v4inv6buf;
v6 = 0;
} else
scopeid = ((struct sockaddr_in6 *)sa)->sin6_scope_id;
}
if(!inet_ntop(v6?AF_INET6:AF_INET,ip,host,hostlen))
return EAI_OVERFLOW;
if(scopeid) {
size_t l = strlen(host);
if(snprintf(host+l, hostlen-l, "%%%u", scopeid) >= hostlen-l)
return EAI_OVERFLOW;
}
}
if(servlen) {
if(snprintf(serv, servlen, "%d", ntohs(SOCKPORT(*sa))) >= servlen)
return EAI_OVERFLOW;
}
}
return 0;
}
HOOKFUNC(struct hostent*, gethostbyaddr, const void *addr, socklen_t len, int type) {
INIT();
PDEBUG("TODO: proper gethostbyaddr hook\n");
static char buf[16];
static char ipv4[4];
static char *list[2];
static char *aliases[1];
static struct hostent he;
if(proxychains_resolver == DNSLF_LIBC)
return true_gethostbyaddr(addr, len, type);
else {
PDEBUG("len %u\n", len);
if(len != 4)
return NULL;
he.h_name = buf;
memcpy(ipv4, addr, 4);
list[0] = ipv4;
list[1] = NULL;
he.h_addr_list = list;
he.h_addrtype = AF_INET;
aliases[0] = NULL;
he.h_aliases = aliases;
he.h_length = 4;
pc_stringfromipv4((unsigned char *) addr, buf);
return &he;
}
return NULL;
}
#ifndef MSG_FASTOPEN
# define MSG_FASTOPEN 0x20000000
#endif
HOOKFUNC(ssize_t, sendto, int sockfd, const void *buf, size_t len, int flags,
const struct sockaddr *dest_addr, socklen_t addrlen) {
INIT();
PFUNC();
if (flags & MSG_FASTOPEN) {
if (!connect(sockfd, dest_addr, addrlen) && errno != EINPROGRESS) {
return -1;
}
dest_addr = NULL;
addrlen = 0;
flags &= ~MSG_FASTOPEN;
}
return true_sendto(sockfd, buf, len, flags, dest_addr, addrlen);
}
#ifdef MONTEREY_HOOKING
#define SETUP_SYM(X) do { if (! true_ ## X ) true_ ## X = &X; } while(0)
#define SETUP_SYM_OPTIONAL(X)
#else
#define SETUP_SYM_IMPL(X, IS_MANDATORY) do { if (! true_ ## X ) true_ ## X = load_sym( # X, X, IS_MANDATORY ); } while(0)
#define SETUP_SYM(X) SETUP_SYM_IMPL(X, 1)
#define SETUP_SYM_OPTIONAL(X) SETUP_SYM_IMPL(X, 0)
#endif
static void setup_hooks(void) {
SETUP_SYM(connect);
SETUP_SYM(sendto);
SETUP_SYM(gethostbyname);
SETUP_SYM(getaddrinfo);
SETUP_SYM(freeaddrinfo);
SETUP_SYM(gethostbyaddr);
SETUP_SYM(getnameinfo);
#ifdef IS_SOLARIS
SETUP_SYM(__xnet_connect);
#endif
SETUP_SYM(close);
SETUP_SYM_OPTIONAL(close_range);
}
#ifdef MONTEREY_HOOKING
#define DYLD_INTERPOSE(_replacement,_replacee) \
__attribute__((used)) static struct{ const void* replacement; const void* replacee; } _interpose_##_replacee \
__attribute__((section ("__DATA,__interpose"))) = { (const void*)(unsigned long)&_replacement, (const void*)(unsigned long)&_replacee };
#define DYLD_HOOK(F) DYLD_INTERPOSE(pxcng_ ## F, F)
DYLD_HOOK(connect);
DYLD_HOOK(sendto);
DYLD_HOOK(gethostbyname);
DYLD_HOOK(getaddrinfo);
DYLD_HOOK(freeaddrinfo);
DYLD_HOOK(gethostbyaddr);
DYLD_HOOK(getnameinfo);
DYLD_HOOK(close);
#endif