mirror of
https://github.com/moparisthebest/curl
synced 2024-11-13 21:15:08 -05:00
1046 lines
28 KiB
C
1046 lines
28 KiB
C
/***************************************************************************
|
|
* _ _ ____ _
|
|
* Project ___| | | | _ \| |
|
|
* / __| | | | |_) | |
|
|
* | (__| |_| | _ <| |___
|
|
* \___|\___/|_| \_\_____|
|
|
*
|
|
* Copyright (C) 1998 - 2020, Daniel Stenberg, <daniel@haxx.se>, et al.
|
|
*
|
|
* This software is licensed as described in the file COPYING, which
|
|
* you should have received as part of this distribution. The terms
|
|
* are also available at https://curl.haxx.se/docs/copyright.html.
|
|
*
|
|
* You may opt to use, copy, modify, merge, publish, distribute and/or sell
|
|
* copies of the Software, and permit persons to whom the Software is
|
|
* furnished to do so, under the terms of the COPYING file.
|
|
*
|
|
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
|
|
* KIND, either express or implied.
|
|
*
|
|
***************************************************************************/
|
|
#include "server_setup.h"
|
|
#include <stdlib.h>
|
|
|
|
/* Function
|
|
*
|
|
* Accepts a TCP connection on a custom port (IPv4 or IPv6). Connects to a
|
|
* given addr + port backend (that is NOT extracted form the client's
|
|
* request). The backend server default to connect to can be set with
|
|
* --backend and --backendport.
|
|
*
|
|
* Read commands from FILE (set with --config). The commands control how to
|
|
* act and is reset to defaults each client TCP connect.
|
|
*
|
|
* Config file keywords:
|
|
*
|
|
* "version [number: 5]" - requires the communication to use this version.
|
|
* "nmethods_min [number: 1]" - the minimum numberf NMETHODS the client must
|
|
* state
|
|
* "nmethods_max [number: 3]" - the minimum numberf NMETHODS the client must
|
|
* state
|
|
* "user [string]" - the user name that must match (if method is 2)
|
|
* "password [string]" - the password that must match (if method is 2)
|
|
* "backend [IPv4]" - numerical IPv4 address of backend to connect to
|
|
* "backendport [number:0]" - TCP port of backend to connect to. 0 means use
|
|
the client's specified port number.
|
|
* "method [number: 0]" - connect method to respond with:
|
|
* 0 - no auth
|
|
* 1 - GSSAPI (not supported)
|
|
* 2 - user + password
|
|
* "response [number]" - the decimal number to repsond to a connect
|
|
* SOCKS5: 0 is OK, SOCKS4: 90 is ok
|
|
*
|
|
*/
|
|
|
|
/* based on sockfilt.c */
|
|
|
|
#ifdef HAVE_SIGNAL_H
|
|
#include <signal.h>
|
|
#endif
|
|
#ifdef HAVE_NETINET_IN_H
|
|
#include <netinet/in.h>
|
|
#endif
|
|
#ifdef HAVE_NETINET_IN6_H
|
|
#include <netinet/in6.h>
|
|
#endif
|
|
#ifdef HAVE_ARPA_INET_H
|
|
#include <arpa/inet.h>
|
|
#endif
|
|
#ifdef HAVE_NETDB_H
|
|
#include <netdb.h>
|
|
#endif
|
|
|
|
#define ENABLE_CURLX_PRINTF
|
|
/* make the curlx header define all printf() functions to use the curlx_*
|
|
versions instead */
|
|
#include "curlx.h" /* from the private lib dir */
|
|
#include "getpart.h"
|
|
#include "inet_pton.h"
|
|
#include "util.h"
|
|
#include "server_sockaddr.h"
|
|
#include "warnless.h"
|
|
|
|
/* include memdebug.h last */
|
|
#include "memdebug.h"
|
|
|
|
#ifdef USE_WINSOCK
|
|
#undef EINTR
|
|
#define EINTR 4 /* errno.h value */
|
|
#undef EAGAIN
|
|
#define EAGAIN 11 /* errno.h value */
|
|
#undef ENOMEM
|
|
#define ENOMEM 12 /* errno.h value */
|
|
#undef EINVAL
|
|
#define EINVAL 22 /* errno.h value */
|
|
#endif
|
|
|
|
#define DEFAULT_PORT 8905
|
|
|
|
#ifndef DEFAULT_LOGFILE
|
|
#define DEFAULT_LOGFILE "log/socksd.log"
|
|
#endif
|
|
|
|
#ifndef DEFAULT_CONFIG
|
|
#define DEFAULT_CONFIG "socksd.config"
|
|
#endif
|
|
|
|
static const char *backendaddr = "127.0.0.1";
|
|
static unsigned short backendport = 0; /* default is use client's */
|
|
|
|
struct configurable {
|
|
unsigned char version; /* initial version byte in the request must match
|
|
this */
|
|
unsigned char nmethods_min; /* minimum number of nmethods to expect */
|
|
unsigned char nmethods_max; /* maximum number of nmethods to expect */
|
|
unsigned char responseversion;
|
|
unsigned char responsemethod;
|
|
unsigned char reqcmd;
|
|
unsigned char connectrep;
|
|
unsigned short port; /* backend port */
|
|
char addr[32]; /* backend IPv4 numerical */
|
|
char user[256];
|
|
char password[256];
|
|
};
|
|
|
|
#define CONFIG_VERSION 5
|
|
#define CONFIG_NMETHODS_MIN 1 /* unauth, gssapi, auth */
|
|
#define CONFIG_NMETHODS_MAX 3
|
|
#define CONFIG_RESPONSEVERSION CONFIG_VERSION
|
|
#define CONFIG_RESPONSEMETHOD 0 /* no auth */
|
|
#define CONFIG_REQCMD 1 /* CONNECT */
|
|
#define CONFIG_PORT backendport
|
|
#define CONFIG_ADDR backendaddr
|
|
#define CONFIG_CONNECTREP 0
|
|
|
|
static struct configurable config;
|
|
|
|
const char *serverlogfile = DEFAULT_LOGFILE;
|
|
static const char *configfile = DEFAULT_CONFIG;
|
|
|
|
#ifdef ENABLE_IPV6
|
|
static bool use_ipv6 = FALSE;
|
|
#endif
|
|
static const char *ipv_inuse = "IPv4";
|
|
static unsigned short port = DEFAULT_PORT;
|
|
|
|
static void resetdefaults(void)
|
|
{
|
|
logmsg("Reset to defaults");
|
|
config.version = CONFIG_VERSION;
|
|
config.nmethods_min = CONFIG_NMETHODS_MIN;
|
|
config.nmethods_max = CONFIG_NMETHODS_MAX;
|
|
config.responseversion = CONFIG_RESPONSEVERSION;
|
|
config.responsemethod = CONFIG_RESPONSEMETHOD;
|
|
config.reqcmd = CONFIG_REQCMD;
|
|
config.connectrep = CONFIG_CONNECTREP;
|
|
config.port = CONFIG_PORT;
|
|
strcpy(config.addr, CONFIG_ADDR);
|
|
strcpy(config.user, "user");
|
|
strcpy(config.password, "password");
|
|
}
|
|
|
|
static unsigned char byteval(char *value)
|
|
{
|
|
unsigned long num = strtoul(value, NULL, 10);
|
|
return num & 0xff;
|
|
}
|
|
|
|
static unsigned short shortval(char *value)
|
|
{
|
|
unsigned long num = strtoul(value, NULL, 10);
|
|
return num & 0xffff;
|
|
}
|
|
|
|
static void getconfig(void)
|
|
{
|
|
FILE *fp = fopen(configfile, FOPEN_READTEXT);
|
|
resetdefaults();
|
|
if(fp) {
|
|
char buffer[512];
|
|
logmsg("parse config file");
|
|
while(fgets(buffer, sizeof(buffer), fp)) {
|
|
char key[32];
|
|
char value[32];
|
|
if(2 == sscanf(buffer, "%31s %31s", key, value)) {
|
|
if(!strcmp(key, "version")) {
|
|
config.version = byteval(value);
|
|
logmsg("version [%d] set", config.version);
|
|
}
|
|
else if(!strcmp(key, "nmethods_min")) {
|
|
config.nmethods_min = byteval(value);
|
|
logmsg("nmethods_min [%d] set", config.nmethods_min);
|
|
}
|
|
else if(!strcmp(key, "nmethods_max")) {
|
|
config.nmethods_max = byteval(value);
|
|
logmsg("nmethods_max [%d] set", config.nmethods_max);
|
|
}
|
|
else if(!strcmp(key, "backend")) {
|
|
strcpy(config.addr, value);
|
|
logmsg("backend [%s] set", config.addr);
|
|
}
|
|
else if(!strcmp(key, "backendport")) {
|
|
config.port = shortval(value);
|
|
logmsg("backendport [%d] set", config.port);
|
|
}
|
|
else if(!strcmp(key, "user")) {
|
|
strcpy(config.user, value);
|
|
logmsg("user [%s] set", config.user);
|
|
}
|
|
else if(!strcmp(key, "password")) {
|
|
strcpy(config.password, value);
|
|
logmsg("password [%s] set", config.password);
|
|
}
|
|
/* Methods:
|
|
o X'00' NO AUTHENTICATION REQUIRED
|
|
o X'01' GSSAPI
|
|
o X'02' USERNAME/PASSWORD
|
|
*/
|
|
else if(!strcmp(key, "method")) {
|
|
config.responsemethod = byteval(value);
|
|
logmsg("method [%d] set", config.responsemethod);
|
|
}
|
|
else if(!strcmp(key, "response")) {
|
|
config.connectrep = byteval(value);
|
|
logmsg("response [%d] set", config.connectrep);
|
|
}
|
|
}
|
|
}
|
|
fclose(fp);
|
|
}
|
|
}
|
|
|
|
static void loghex(unsigned char *buffer, ssize_t len)
|
|
{
|
|
char data[1200];
|
|
ssize_t i;
|
|
unsigned char *ptr = buffer;
|
|
char *optr = data;
|
|
ssize_t width = 0;
|
|
int left = sizeof(data);
|
|
|
|
for(i = 0; i<len && (left >= 0); i++) {
|
|
msnprintf(optr, left, "%02x", ptr[i]);
|
|
width += 2;
|
|
optr += 2;
|
|
left -= 2;
|
|
}
|
|
if(width)
|
|
logmsg("'%s'", data);
|
|
}
|
|
|
|
/* RFC 1928, SOCKS5 byte index */
|
|
#define SOCKS5_VERSION 0
|
|
#define SOCKS5_NMETHODS 1 /* number of methods that is listed */
|
|
|
|
/* in the request: */
|
|
#define SOCKS5_REQCMD 1
|
|
#define SOCKS5_RESERVED 2
|
|
#define SOCKS5_ATYP 3
|
|
#define SOCKS5_DSTADDR 4
|
|
|
|
/* connect response */
|
|
#define SOCKS5_REP 1
|
|
#define SOCKS5_BNDADDR 4
|
|
|
|
/* auth request */
|
|
#define SOCKS5_ULEN 1
|
|
#define SOCKS5_UNAME 2
|
|
|
|
#define SOCKS4_CD 1
|
|
#define SOCKS4_DSTPORT 2
|
|
|
|
/* connect to a given IPv4 address, not the one asked for */
|
|
static curl_socket_t socksconnect(unsigned short connectport,
|
|
const char *connectaddr)
|
|
{
|
|
int rc;
|
|
srvr_sockaddr_union_t me;
|
|
curl_socket_t sock = socket(AF_INET, SOCK_STREAM, 0);
|
|
if(sock == CURL_SOCKET_BAD)
|
|
return CURL_SOCKET_BAD;
|
|
memset(&me.sa4, 0, sizeof(me.sa4));
|
|
me.sa4.sin_family = AF_INET;
|
|
me.sa4.sin_port = htons(connectport);
|
|
me.sa4.sin_addr.s_addr = INADDR_ANY;
|
|
Curl_inet_pton(AF_INET, connectaddr, &me.sa4.sin_addr);
|
|
|
|
rc = connect(sock, &me.sa, sizeof(me.sa4));
|
|
|
|
if(rc) {
|
|
int error = SOCKERRNO;
|
|
logmsg("Error connecting to %s:%hu: (%d) %s",
|
|
connectaddr, connectport, error, strerror(error));
|
|
return CURL_SOCKET_BAD;
|
|
}
|
|
logmsg("Connected fine to %s:%d", connectaddr, connectport);
|
|
return sock;
|
|
}
|
|
|
|
static curl_socket_t socks4(curl_socket_t fd,
|
|
unsigned char *buffer,
|
|
ssize_t rc)
|
|
{
|
|
unsigned char response[256 + 16];
|
|
curl_socket_t connfd;
|
|
unsigned char cd;
|
|
unsigned short s4port;
|
|
|
|
if(buffer[SOCKS4_CD] != 1) {
|
|
logmsg("SOCKS4 CD is not 1: %d", buffer[SOCKS4_CD]);
|
|
return CURL_SOCKET_BAD;
|
|
}
|
|
if(rc < 9) {
|
|
logmsg("SOCKS4 connect message too short: %d", rc);
|
|
return CURL_SOCKET_BAD;
|
|
}
|
|
if(!config.port)
|
|
s4port = (unsigned short)((buffer[SOCKS4_DSTPORT]<<8) |
|
|
(buffer[SOCKS4_DSTPORT + 1]));
|
|
else
|
|
s4port = config.port;
|
|
|
|
connfd = socksconnect(s4port, config.addr);
|
|
if(connfd == CURL_SOCKET_BAD) {
|
|
/* failed */
|
|
cd = 91;
|
|
}
|
|
else {
|
|
/* success */
|
|
cd = 90;
|
|
}
|
|
response[0] = 0; /* reply version 0 */
|
|
response[1] = cd; /* result */
|
|
/* copy port and address from connect request */
|
|
memcpy(&response[2], &buffer[SOCKS4_DSTPORT], 6);
|
|
rc = (send)(fd, (char *)response, 8, 0);
|
|
if(rc != 8) {
|
|
logmsg("Sending SOCKS4 response failed!");
|
|
return CURL_SOCKET_BAD;
|
|
}
|
|
logmsg("Sent %d bytes", rc);
|
|
loghex(response, rc);
|
|
|
|
if(cd == 90)
|
|
/* now do the transfer */
|
|
return connfd;
|
|
|
|
if(connfd != CURL_SOCKET_BAD)
|
|
sclose(connfd);
|
|
|
|
return CURL_SOCKET_BAD;
|
|
}
|
|
|
|
static curl_socket_t sockit(curl_socket_t fd)
|
|
{
|
|
unsigned char buffer[256 + 16];
|
|
unsigned char response[256 + 16];
|
|
ssize_t rc;
|
|
unsigned char len;
|
|
unsigned char type;
|
|
unsigned char rep = 0;
|
|
unsigned char *address;
|
|
unsigned short socksport;
|
|
curl_socket_t connfd = CURL_SOCKET_BAD;
|
|
unsigned short s5port;
|
|
|
|
getconfig();
|
|
|
|
rc = recv(fd, (char *)buffer, sizeof(buffer), 0);
|
|
|
|
logmsg("READ %d bytes", rc);
|
|
loghex(buffer, rc);
|
|
|
|
if(buffer[SOCKS5_VERSION] == 4)
|
|
return socks4(fd, buffer, rc);
|
|
|
|
if(buffer[SOCKS5_VERSION] != config.version) {
|
|
logmsg("VERSION byte not %d", config.version);
|
|
return CURL_SOCKET_BAD;
|
|
}
|
|
if((buffer[SOCKS5_NMETHODS] < config.nmethods_min) ||
|
|
(buffer[SOCKS5_NMETHODS] > config.nmethods_max)) {
|
|
logmsg("NMETHODS byte not within %d - %d ",
|
|
config.nmethods_min, config.nmethods_max);
|
|
return CURL_SOCKET_BAD;
|
|
}
|
|
/* after NMETHODS follows that many bytes listing the methods the client
|
|
says it supports */
|
|
if(rc != (buffer[SOCKS5_NMETHODS] + 2)) {
|
|
logmsg("Expected %d bytes, got %d", buffer[SOCKS5_NMETHODS] + 2, rc);
|
|
return CURL_SOCKET_BAD;
|
|
}
|
|
logmsg("Incoming request deemed fine!");
|
|
|
|
/* respond with two bytes: VERSION + METHOD */
|
|
response[0] = config.responseversion;
|
|
response[1] = config.responsemethod;
|
|
rc = (send)(fd, (char *)response, 2, 0);
|
|
if(rc != 2) {
|
|
logmsg("Sending response failed!");
|
|
return CURL_SOCKET_BAD;
|
|
}
|
|
logmsg("Sent %d bytes", rc);
|
|
loghex(response, rc);
|
|
|
|
/* expect the request or auth */
|
|
rc = recv(fd, (char *)buffer, sizeof(buffer), 0);
|
|
|
|
logmsg("READ %d bytes", rc);
|
|
loghex(buffer, rc);
|
|
|
|
if(config.responsemethod == 2) {
|
|
/* RFC 1929 authentication
|
|
+----+------+----------+------+----------+
|
|
|VER | ULEN | UNAME | PLEN | PASSWD |
|
|
+----+------+----------+------+----------+
|
|
| 1 | 1 | 1 to 255 | 1 | 1 to 255 |
|
|
+----+------+----------+------+----------+
|
|
*/
|
|
unsigned char ulen;
|
|
unsigned char plen;
|
|
bool login = TRUE;
|
|
if(rc < 5) {
|
|
logmsg("Too short auth input: %d", rc);
|
|
return CURL_SOCKET_BAD;
|
|
}
|
|
if(buffer[SOCKS5_VERSION] != 1) {
|
|
logmsg("Auth VERSION byte not 1, got %d", buffer[SOCKS5_VERSION]);
|
|
return CURL_SOCKET_BAD;
|
|
}
|
|
ulen = buffer[SOCKS5_ULEN];
|
|
if(rc < 4 + ulen) {
|
|
logmsg("Too short packet for username: %d", rc);
|
|
return CURL_SOCKET_BAD;
|
|
}
|
|
plen = buffer[SOCKS5_ULEN + ulen + 1];
|
|
if(rc < 3 + ulen + plen) {
|
|
logmsg("Too short packet for ulen %d plen %d: %d", ulen, plen, rc);
|
|
return CURL_SOCKET_BAD;
|
|
}
|
|
if((ulen != strlen(config.user)) ||
|
|
(plen != strlen(config.password)) ||
|
|
memcmp(&buffer[SOCKS5_UNAME], config.user, ulen) ||
|
|
memcmp(&buffer[SOCKS5_UNAME + ulen + 1], config.password, plen)) {
|
|
/* no match! */
|
|
logmsg("mismatched credentials!");
|
|
login = FALSE;
|
|
}
|
|
response[0] = 1;
|
|
response[1] = login ? 0 : 1;
|
|
rc = (send)(fd, (char *)response, 2, 0);
|
|
if(rc != 2) {
|
|
logmsg("Sending auth response failed!");
|
|
return CURL_SOCKET_BAD;
|
|
}
|
|
logmsg("Sent %d bytes", rc);
|
|
loghex(response, rc);
|
|
if(!login)
|
|
return CURL_SOCKET_BAD;
|
|
|
|
/* expect the request */
|
|
rc = recv(fd, (char *)buffer, sizeof(buffer), 0);
|
|
|
|
logmsg("READ %d bytes", rc);
|
|
loghex(buffer, rc);
|
|
}
|
|
if(rc < 6) {
|
|
logmsg("Too short for request: %d", rc);
|
|
return CURL_SOCKET_BAD;
|
|
}
|
|
|
|
if(buffer[SOCKS5_VERSION] != config.version) {
|
|
logmsg("Request VERSION byte not %d", config.version);
|
|
return CURL_SOCKET_BAD;
|
|
}
|
|
/* 1 == CONNECT */
|
|
if(buffer[SOCKS5_REQCMD] != config.reqcmd) {
|
|
logmsg("Request COMMAND byte not %d", config.reqcmd);
|
|
return CURL_SOCKET_BAD;
|
|
}
|
|
/* reserved, should be zero */
|
|
if(buffer[SOCKS5_RESERVED] != 0) {
|
|
logmsg("Request COMMAND byte not %d", config.reqcmd);
|
|
return CURL_SOCKET_BAD;
|
|
}
|
|
/* ATYP:
|
|
o IP V4 address: X'01'
|
|
o DOMAINNAME: X'03'
|
|
o IP V6 address: X'04'
|
|
*/
|
|
type = buffer[SOCKS5_ATYP];
|
|
address = &buffer[SOCKS5_DSTADDR];
|
|
switch(type) {
|
|
case 1:
|
|
/* 4 bytes IPv4 address */
|
|
len = 4;
|
|
break;
|
|
case 3:
|
|
/* The first octet of the address field contains the number of octets of
|
|
name that follow */
|
|
len = buffer[SOCKS5_DSTADDR];
|
|
len++;
|
|
break;
|
|
case 4:
|
|
/* 16 bytes IPv6 address */
|
|
len = 16;
|
|
break;
|
|
default:
|
|
logmsg("Unknown ATYP %d", type);
|
|
return CURL_SOCKET_BAD;
|
|
}
|
|
if(rc < (4 + len + 2)) {
|
|
logmsg("Request too short: %d, expected %d", rc, 4 + len + 2);
|
|
return CURL_SOCKET_BAD;
|
|
}
|
|
|
|
if(!config.port) {
|
|
unsigned char *portp = &buffer[SOCKS5_DSTADDR + len];
|
|
s5port = (unsigned short)((portp[0]<<8) | (portp[1]));
|
|
}
|
|
else
|
|
s5port = config.port;
|
|
|
|
if(!config.connectrep)
|
|
connfd = socksconnect(s5port, config.addr);
|
|
|
|
if(connfd == CURL_SOCKET_BAD) {
|
|
/* failed */
|
|
rep = 1;
|
|
}
|
|
else {
|
|
rep = config.connectrep;
|
|
}
|
|
|
|
/* */
|
|
response[SOCKS5_VERSION] = config.responseversion;
|
|
|
|
/*
|
|
o REP Reply field:
|
|
o X'00' succeeded
|
|
o X'01' general SOCKS server failure
|
|
o X'02' connection not allowed by ruleset
|
|
o X'03' Network unreachable
|
|
o X'04' Host unreachable
|
|
o X'05' Connection refused
|
|
o X'06' TTL expired
|
|
o X'07' Command not supported
|
|
o X'08' Address type not supported
|
|
o X'09' to X'FF' unassigned
|
|
*/
|
|
response[SOCKS5_REP] = rep;
|
|
response[SOCKS5_RESERVED] = 0; /* must be zero */
|
|
response[SOCKS5_ATYP] = type; /* address type */
|
|
|
|
/* mirror back the original addr + port */
|
|
|
|
/* address or hostname */
|
|
memcpy(&response[SOCKS5_BNDADDR], address, len);
|
|
|
|
/* port number */
|
|
memcpy(&response[SOCKS5_BNDADDR + len],
|
|
&buffer[SOCKS5_DSTADDR + len], sizeof(socksport));
|
|
|
|
rc = (send)(fd, (char *)response, len + 6, 0);
|
|
if(rc != (len + 6)) {
|
|
logmsg("Sending connect response failed!");
|
|
return CURL_SOCKET_BAD;
|
|
}
|
|
logmsg("Sent %d bytes", rc);
|
|
loghex(response, rc);
|
|
|
|
if(!rep)
|
|
return connfd;
|
|
|
|
if(connfd != CURL_SOCKET_BAD)
|
|
sclose(connfd);
|
|
|
|
return CURL_SOCKET_BAD;
|
|
}
|
|
|
|
struct perclient {
|
|
size_t fromremote;
|
|
size_t fromclient;
|
|
curl_socket_t remotefd;
|
|
curl_socket_t clientfd;
|
|
bool used;
|
|
};
|
|
|
|
/* return non-zero when transfer is done */
|
|
static int tunnel(struct perclient *cp, fd_set *fds)
|
|
{
|
|
ssize_t nread;
|
|
ssize_t nwrite;
|
|
char buffer[512];
|
|
if(FD_ISSET(cp->clientfd, fds)) {
|
|
/* read from client, send to remote */
|
|
nread = recv(cp->clientfd, buffer, sizeof(buffer), 0);
|
|
if(nread > 0) {
|
|
nwrite = send(cp->remotefd, (char *)buffer,
|
|
(SEND_TYPE_ARG3)nread, 0);
|
|
if(nwrite != nread)
|
|
return 1;
|
|
cp->fromclient += nwrite;
|
|
}
|
|
else
|
|
return 1;
|
|
}
|
|
if(FD_ISSET(cp->remotefd, fds)) {
|
|
/* read from remote, send to client */
|
|
nread = recv(cp->remotefd, buffer, sizeof(buffer), 0);
|
|
if(nread > 0) {
|
|
nwrite = send(cp->clientfd, (char *)buffer,
|
|
(SEND_TYPE_ARG3)nread, 0);
|
|
if(nwrite != nread)
|
|
return 1;
|
|
cp->fromremote += nwrite;
|
|
}
|
|
else
|
|
return 1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
sockfdp is a pointer to an established stream or CURL_SOCKET_BAD
|
|
|
|
if sockfd is CURL_SOCKET_BAD, listendfd is a listening socket we must
|
|
accept()
|
|
*/
|
|
static bool incoming(curl_socket_t listenfd)
|
|
{
|
|
fd_set fds_read;
|
|
fd_set fds_write;
|
|
fd_set fds_err;
|
|
int clients = 0; /* connected clients */
|
|
struct perclient c[2];
|
|
|
|
memset(c, 0, sizeof(c));
|
|
if(got_exit_signal) {
|
|
logmsg("signalled to die, exiting...");
|
|
return FALSE;
|
|
}
|
|
|
|
#ifdef HAVE_GETPPID
|
|
/* As a last resort, quit if socks5 process becomes orphan. */
|
|
if(getppid() <= 1) {
|
|
logmsg("process becomes orphan, exiting");
|
|
return FALSE;
|
|
}
|
|
#endif
|
|
|
|
do {
|
|
int i;
|
|
ssize_t rc;
|
|
int error = 0;
|
|
curl_socket_t sockfd = listenfd;
|
|
int maxfd = (int)sockfd;
|
|
|
|
FD_ZERO(&fds_read);
|
|
FD_ZERO(&fds_write);
|
|
FD_ZERO(&fds_err);
|
|
|
|
/* there's always a socket to wait for */
|
|
FD_SET(sockfd, &fds_read);
|
|
|
|
for(i = 0; i < 2; i++) {
|
|
if(c[i].used) {
|
|
curl_socket_t fd = c[i].clientfd;
|
|
FD_SET(fd, &fds_read);
|
|
if((int)fd > maxfd)
|
|
maxfd = (int)fd;
|
|
fd = c[i].remotefd;
|
|
FD_SET(fd, &fds_read);
|
|
if((int)fd > maxfd)
|
|
maxfd = (int)fd;
|
|
}
|
|
}
|
|
|
|
do {
|
|
/* select() blocking behavior call on blocking descriptors please */
|
|
rc = select(maxfd + 1, &fds_read, &fds_write, &fds_err, NULL);
|
|
if(got_exit_signal) {
|
|
logmsg("signalled to die, exiting...");
|
|
return FALSE;
|
|
}
|
|
} while((rc == -1) && ((error = errno) == EINTR));
|
|
|
|
if(rc < 0) {
|
|
logmsg("select() failed with error: (%d) %s",
|
|
error, strerror(error));
|
|
return FALSE;
|
|
}
|
|
|
|
if((clients < 2) && FD_ISSET(sockfd, &fds_read)) {
|
|
curl_socket_t newfd = accept(sockfd, NULL, NULL);
|
|
if(CURL_SOCKET_BAD == newfd) {
|
|
error = SOCKERRNO;
|
|
logmsg("accept(%d, NULL, NULL) failed with error: (%d) %s",
|
|
sockfd, error, strerror(error));
|
|
}
|
|
else {
|
|
curl_socket_t remotefd;
|
|
logmsg("====> Client connect, fd %d. Read config from %s",
|
|
newfd, configfile);
|
|
remotefd = sockit(newfd); /* SOCKS until done */
|
|
if(remotefd == CURL_SOCKET_BAD) {
|
|
logmsg("====> Client disconnect");
|
|
sclose(newfd);
|
|
}
|
|
else {
|
|
struct perclient *cp = &c[0];
|
|
logmsg("====> Tunnel transfer");
|
|
|
|
if(c[0].used)
|
|
cp = &c[1];
|
|
cp->fromremote = 0;
|
|
cp->fromclient = 0;
|
|
cp->clientfd = newfd;
|
|
cp->remotefd = remotefd;
|
|
cp->used = TRUE;
|
|
clients++;
|
|
}
|
|
|
|
}
|
|
}
|
|
for(i = 0; i < 2; i++) {
|
|
struct perclient *cp = &c[i];
|
|
if(cp->used) {
|
|
if(tunnel(cp, &fds_read)) {
|
|
logmsg("SOCKS transfer completed. Bytes: < %zu > %zu",
|
|
cp->fromremote, cp->fromclient);
|
|
sclose(cp->clientfd);
|
|
sclose(cp->remotefd);
|
|
cp->used = FALSE;
|
|
clients--;
|
|
}
|
|
}
|
|
}
|
|
} while(clients);
|
|
|
|
return TRUE;
|
|
}
|
|
|
|
static curl_socket_t sockdaemon(curl_socket_t sock,
|
|
unsigned short *listenport)
|
|
{
|
|
/* passive daemon style */
|
|
srvr_sockaddr_union_t listener;
|
|
int flag;
|
|
int rc;
|
|
int totdelay = 0;
|
|
int maxretr = 10;
|
|
int delay = 20;
|
|
int attempt = 0;
|
|
int error = 0;
|
|
|
|
do {
|
|
attempt++;
|
|
flag = 1;
|
|
rc = setsockopt(sock, SOL_SOCKET, SO_REUSEADDR,
|
|
(void *)&flag, sizeof(flag));
|
|
if(rc) {
|
|
error = SOCKERRNO;
|
|
logmsg("setsockopt(SO_REUSEADDR) failed with error: (%d) %s",
|
|
error, strerror(error));
|
|
if(maxretr) {
|
|
rc = wait_ms(delay);
|
|
if(rc) {
|
|
/* should not happen */
|
|
error = errno;
|
|
logmsg("wait_ms() failed with error: (%d) %s",
|
|
error, strerror(error));
|
|
sclose(sock);
|
|
return CURL_SOCKET_BAD;
|
|
}
|
|
if(got_exit_signal) {
|
|
logmsg("signalled to die, exiting...");
|
|
sclose(sock);
|
|
return CURL_SOCKET_BAD;
|
|
}
|
|
totdelay += delay;
|
|
delay *= 2; /* double the sleep for next attempt */
|
|
}
|
|
}
|
|
} while(rc && maxretr--);
|
|
|
|
if(rc) {
|
|
logmsg("setsockopt(SO_REUSEADDR) failed %d times in %d ms. Error: (%d) %s",
|
|
attempt, totdelay, error, strerror(error));
|
|
logmsg("Continuing anyway...");
|
|
}
|
|
|
|
/* When the specified listener port is zero, it is actually a
|
|
request to let the system choose a non-zero available port. */
|
|
|
|
#ifdef ENABLE_IPV6
|
|
if(!use_ipv6) {
|
|
#endif
|
|
memset(&listener.sa4, 0, sizeof(listener.sa4));
|
|
listener.sa4.sin_family = AF_INET;
|
|
listener.sa4.sin_addr.s_addr = INADDR_ANY;
|
|
listener.sa4.sin_port = htons(*listenport);
|
|
rc = bind(sock, &listener.sa, sizeof(listener.sa4));
|
|
#ifdef ENABLE_IPV6
|
|
}
|
|
else {
|
|
memset(&listener.sa6, 0, sizeof(listener.sa6));
|
|
listener.sa6.sin6_family = AF_INET6;
|
|
listener.sa6.sin6_addr = in6addr_any;
|
|
listener.sa6.sin6_port = htons(*listenport);
|
|
rc = bind(sock, &listener.sa, sizeof(listener.sa6));
|
|
}
|
|
#endif /* ENABLE_IPV6 */
|
|
if(rc) {
|
|
error = SOCKERRNO;
|
|
logmsg("Error binding socket on port %hu: (%d) %s",
|
|
*listenport, error, strerror(error));
|
|
sclose(sock);
|
|
return CURL_SOCKET_BAD;
|
|
}
|
|
|
|
if(!*listenport) {
|
|
/* The system was supposed to choose a port number, figure out which
|
|
port we actually got and update the listener port value with it. */
|
|
curl_socklen_t la_size;
|
|
srvr_sockaddr_union_t localaddr;
|
|
#ifdef ENABLE_IPV6
|
|
if(!use_ipv6)
|
|
#endif
|
|
la_size = sizeof(localaddr.sa4);
|
|
#ifdef ENABLE_IPV6
|
|
else
|
|
la_size = sizeof(localaddr.sa6);
|
|
#endif
|
|
memset(&localaddr.sa, 0, (size_t)la_size);
|
|
if(getsockname(sock, &localaddr.sa, &la_size) < 0) {
|
|
error = SOCKERRNO;
|
|
logmsg("getsockname() failed with error: (%d) %s",
|
|
error, strerror(error));
|
|
sclose(sock);
|
|
return CURL_SOCKET_BAD;
|
|
}
|
|
switch(localaddr.sa.sa_family) {
|
|
case AF_INET:
|
|
*listenport = ntohs(localaddr.sa4.sin_port);
|
|
break;
|
|
#ifdef ENABLE_IPV6
|
|
case AF_INET6:
|
|
*listenport = ntohs(localaddr.sa6.sin6_port);
|
|
break;
|
|
#endif
|
|
default:
|
|
break;
|
|
}
|
|
if(!*listenport) {
|
|
/* Real failure, listener port shall not be zero beyond this point. */
|
|
logmsg("Apparently getsockname() succeeded, with listener port zero.");
|
|
logmsg("A valid reason for this failure is a binary built without");
|
|
logmsg("proper network library linkage. This might not be the only");
|
|
logmsg("reason, but double check it before anything else.");
|
|
sclose(sock);
|
|
return CURL_SOCKET_BAD;
|
|
}
|
|
}
|
|
|
|
/* start accepting connections */
|
|
rc = listen(sock, 5);
|
|
if(0 != rc) {
|
|
error = SOCKERRNO;
|
|
logmsg("listen(%d, 5) failed with error: (%d) %s",
|
|
sock, error, strerror(error));
|
|
sclose(sock);
|
|
return CURL_SOCKET_BAD;
|
|
}
|
|
|
|
return sock;
|
|
}
|
|
|
|
|
|
int main(int argc, char *argv[])
|
|
{
|
|
curl_socket_t sock = CURL_SOCKET_BAD;
|
|
curl_socket_t msgsock = CURL_SOCKET_BAD;
|
|
int wrotepidfile = 0;
|
|
const char *pidname = ".socksd.pid";
|
|
bool juggle_again;
|
|
int error;
|
|
int arg = 1;
|
|
|
|
while(argc>arg) {
|
|
if(!strcmp("--version", argv[arg])) {
|
|
printf("socksd IPv4%s\n",
|
|
#ifdef ENABLE_IPV6
|
|
"/IPv6"
|
|
#else
|
|
""
|
|
#endif
|
|
);
|
|
return 0;
|
|
}
|
|
else if(!strcmp("--pidfile", argv[arg])) {
|
|
arg++;
|
|
if(argc>arg)
|
|
pidname = argv[arg++];
|
|
}
|
|
else if(!strcmp("--config", argv[arg])) {
|
|
arg++;
|
|
if(argc>arg)
|
|
configfile = argv[arg++];
|
|
}
|
|
else if(!strcmp("--backend", argv[arg])) {
|
|
arg++;
|
|
if(argc>arg)
|
|
backendaddr = argv[arg++];
|
|
}
|
|
else if(!strcmp("--backendport", argv[arg])) {
|
|
arg++;
|
|
if(argc>arg)
|
|
backendport = (unsigned short)atoi(argv[arg++]);
|
|
}
|
|
else if(!strcmp("--logfile", argv[arg])) {
|
|
arg++;
|
|
if(argc>arg)
|
|
serverlogfile = argv[arg++];
|
|
}
|
|
else if(!strcmp("--ipv6", argv[arg])) {
|
|
#ifdef ENABLE_IPV6
|
|
ipv_inuse = "IPv6";
|
|
use_ipv6 = TRUE;
|
|
#endif
|
|
arg++;
|
|
}
|
|
else if(!strcmp("--ipv4", argv[arg])) {
|
|
/* for completeness, we support this option as well */
|
|
#ifdef ENABLE_IPV6
|
|
ipv_inuse = "IPv4";
|
|
use_ipv6 = FALSE;
|
|
#endif
|
|
arg++;
|
|
}
|
|
else if(!strcmp("--port", argv[arg])) {
|
|
arg++;
|
|
if(argc>arg) {
|
|
char *endptr;
|
|
unsigned long ulnum = strtoul(argv[arg], &endptr, 10);
|
|
if((endptr != argv[arg] + strlen(argv[arg])) ||
|
|
((ulnum != 0UL) && ((ulnum < 1025UL) || (ulnum > 65535UL)))) {
|
|
fprintf(stderr, "socksd: invalid --port argument (%s)\n",
|
|
argv[arg]);
|
|
return 0;
|
|
}
|
|
port = curlx_ultous(ulnum);
|
|
arg++;
|
|
}
|
|
}
|
|
else {
|
|
puts("Usage: socksd [option]\n"
|
|
" --backend [ipv4 addr]\n"
|
|
" --backendport [TCP port]\n"
|
|
" --config [file]\n"
|
|
" --version\n"
|
|
" --logfile [file]\n"
|
|
" --pidfile [file]\n"
|
|
" --ipv4\n"
|
|
" --ipv6\n"
|
|
" --bindonly\n"
|
|
" --port [port]\n");
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
#ifdef WIN32
|
|
win32_init();
|
|
atexit(win32_cleanup);
|
|
|
|
setmode(fileno(stdin), O_BINARY);
|
|
setmode(fileno(stdout), O_BINARY);
|
|
setmode(fileno(stderr), O_BINARY);
|
|
#endif
|
|
|
|
install_signal_handlers(false);
|
|
|
|
#ifdef ENABLE_IPV6
|
|
if(!use_ipv6)
|
|
#endif
|
|
sock = socket(AF_INET, SOCK_STREAM, 0);
|
|
#ifdef ENABLE_IPV6
|
|
else
|
|
sock = socket(AF_INET6, SOCK_STREAM, 0);
|
|
#endif
|
|
|
|
if(CURL_SOCKET_BAD == sock) {
|
|
error = SOCKERRNO;
|
|
logmsg("Error creating socket: (%d) %s",
|
|
error, strerror(error));
|
|
goto socks5_cleanup;
|
|
}
|
|
|
|
{
|
|
/* passive daemon style */
|
|
sock = sockdaemon(sock, &port);
|
|
if(CURL_SOCKET_BAD == sock) {
|
|
goto socks5_cleanup;
|
|
}
|
|
msgsock = CURL_SOCKET_BAD; /* no stream socket yet */
|
|
}
|
|
|
|
logmsg("Running %s version", ipv_inuse);
|
|
logmsg("Listening on port %hu", port);
|
|
|
|
wrotepidfile = write_pidfile(pidname);
|
|
if(!wrotepidfile) {
|
|
goto socks5_cleanup;
|
|
}
|
|
|
|
do {
|
|
juggle_again = incoming(sock);
|
|
} while(juggle_again);
|
|
|
|
socks5_cleanup:
|
|
|
|
if((msgsock != sock) && (msgsock != CURL_SOCKET_BAD))
|
|
sclose(msgsock);
|
|
|
|
if(sock != CURL_SOCKET_BAD)
|
|
sclose(sock);
|
|
|
|
if(wrotepidfile)
|
|
unlink(pidname);
|
|
|
|
restore_signal_handlers(false);
|
|
|
|
if(got_exit_signal) {
|
|
logmsg("============> socksd exits with signal (%d)", exit_signal);
|
|
/*
|
|
* To properly set the return status of the process we
|
|
* must raise the same signal SIGINT or SIGTERM that we
|
|
* caught and let the old handler take care of it.
|
|
*/
|
|
raise(exit_signal);
|
|
}
|
|
|
|
logmsg("============> socksd quits");
|
|
return 0;
|
|
}
|