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/* Copyright 2004 Nick Mathewson */
/* See LICENSE for licensing information */
/* $Id$ */
#include "orconfig.h"
#include "../common/compat.h"
#include "../common/util.h"
#include "../common/log.h"
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <string.h>
#include <assert.h>
#ifdef HAVE_NETINET_IN_H
#include <netinet/in.h>
#endif
#ifdef HAVE_ARPA_INET_H
#include <arpa/inet.h>
#endif
#ifdef HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h> /* Must be included before sys/stat.h for Ultrix */
#endif
#ifdef HAVE_ERRNO_H
#include <errno.h>
#endif
#ifdef MS_WINDOWS
#if (_MSC_VER <= 1300)
#include <winsock.h>
#else
#include <winsock2.h>
#include <ws2tcpip.h>
#endif
#endif
#define RESPONSE_LEN 8
#define log_sock_error(act, _s) \
do { log_fn(LOG_ERR, "Error while %s: %s", act, \
tor_socket_strerror(tor_socket_errno(_s))); } while(0)
int build_socks4a_resolve_request(char **out,
const char *username,
const char *hostname)
{
size_t len;
tor_assert(out);
tor_assert(username);
tor_assert(hostname);
len = 8 + strlen(username) + 1 + strlen(hostname) + 1;
*out = tor_malloc(len);
(*out)[0] = 4; /* SOCKS version 4 */
(*out)[1] = 0xF0; /* Command: resolve. */
set_uint16((*out)+2, htons(0)); /* port: 0. */
set_uint32((*out)+4, htonl(0x00000001u)); /* addr: 0.0.0.1 */
strcpy((*out)+8, username);
strcpy((*out)+8+strlen(username)+1, hostname);
return len;
}
int parse_socks4a_resolve_response(const char *response, size_t len,
uint32_t *addr_out)
{
uint8_t status;
tor_assert(response);
tor_assert(addr_out);
if (len < RESPONSE_LEN)
return -1;
if (((uint8_t)response[0])!=0) /* version: 0 */
return -1;
status = (uint8_t)response[1];
if (get_uint16(response+2)!=0) /* port: 0 */
return -1;
if (status != 90)
return -1;
*addr_out = ntohl(get_uint32(response+4));
return 0;
}
int do_resolve(const char *hostname, uint32_t sockshost, uint16_t socksport,
uint32_t *result_addr)
{
int s;
struct sockaddr_in socksaddr;
char *req, *cp;
int r, len;
char response_buf[RESPONSE_LEN];
tor_assert(hostname);
tor_assert(result_addr);
s = socket(PF_INET,SOCK_STREAM,IPPROTO_TCP);
if (s<0) {
log_sock_error("creating_socket", -1);
return -1;
}
memset(&socksaddr, 0, sizeof(socksaddr));
socksaddr.sin_family = AF_INET;
socksaddr.sin_port = htons(socksport);
socksaddr.sin_addr.s_addr = htonl(sockshost);
if (connect(s, (struct sockaddr*)&socksaddr, sizeof(socksaddr))) {
log_sock_error("connecting to SOCKS host", s);
return -1;
}
if ((len = build_socks4a_resolve_request(&req, "", hostname))<0) {
log_fn(LOG_ERR, "Error generating SOCKS request");
return -1;
}
cp = req;
while (len) {
r = send(s, cp, len, 0);
if (r<0) {
log_sock_error("sending SOCKS request", s);
tor_free(req);
return -1;
}
len -= r;
cp += r;
}
tor_free(req);
len = 0;
while (len < RESPONSE_LEN) {
r = recv(s, response_buf+len, RESPONSE_LEN-len, 0);
if (r<0) {
log_sock_error("reading SOCKS response", s);
return -1;
}
len += r;
}
if (parse_socks4a_resolve_response(response_buf, RESPONSE_LEN,result_addr)<0){
log_fn(LOG_ERR, "Error parsing SOCKS response");
return -1;
}
return 0;
}
void usage(void)
{
puts("Syntax: tor-resolve [-v] hostname [sockshost:socksport]");
exit(1);
}
int
main(int argc, char **argv)
{
uint32_t sockshost;
uint16_t socksport;
char **arg;
int n_args;
struct in_addr a;
uint32_t result;
arg = &argv[1];
n_args = argc-1;
if (argc < 2)
usage();
if (!strcmp("-v", arg[0])) {
add_stream_log(LOG_DEBUG, LOG_ERR, "<stderr>", stderr);
++arg; --n_args;
} else {
add_stream_log(LOG_WARN, LOG_ERR, "<stderr>", stderr);
}
if (n_args == 1) {
log_fn(LOG_DEBUG, "defaulting to localhost:9050");
sockshost = 0x7f000001u; /* localhost */
socksport = 9050; /* 9050 */
} else if (n_args == 2) {
if (parse_addr_port(arg[1], NULL, &sockshost, &socksport)<0) {
fprintf(stderr, "Couldn't parse/resolve address %s", arg[1]);
return 1;
}
if (socksport == 0) {
log_fn(LOG_DEBUG, "defaulting to port 9050");
socksport = 9050;
}
} else {
usage();
}
if (do_resolve(arg[0], sockshost, socksport, &result))
return 1;
a.s_addr = htonl(result);
printf("%s\n", inet_ntoa(a));
return 0;
}
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