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/*
* libwebsockets - small server side websockets and web server implementation
*
* Copyright (C) 2010 - 2020 Andy Green <andy@warmcat.com>
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to
* deal in the Software without restriction, including without limitation the
* rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
* sell copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*
* Socks5 Client -related helpers
*/
#include "private-lib-core.h"
int
lws_set_socks(struct lws_vhost *vhost, const char *socks)
{
char *p_at, *p_colon;
char user[96];
char password[96];
if (!socks)
return -1;
vhost->socks_user[0] = '\0';
vhost->socks_password[0] = '\0';
p_at = strrchr(socks, '@');
if (p_at) { /* auth is around */
if ((unsigned int)(p_at - socks) > (sizeof(user)
+ sizeof(password) - 2)) {
lwsl_err("Socks auth too long\n");
goto bail;
}
p_colon = strchr(socks, ':');
if (p_colon) {
if ((unsigned int)(p_colon - socks) > (sizeof(user)
- 1) ) {
lwsl_err("Socks user too long\n");
goto bail;
}
if ((unsigned int)(p_at - p_colon) > (sizeof(password)
- 1) ) {
lwsl_err("Socks password too long\n");
goto bail;
}
lws_strncpy(vhost->socks_user, socks,
p_colon - socks + 1);
lws_strncpy(vhost->socks_password, p_colon + 1,
p_at - (p_colon + 1) + 1);
}
lwsl_info(" Socks auth, user: %s, password: %s\n",
vhost->socks_user, vhost->socks_password );
socks = p_at + 1;
}
lws_strncpy(vhost->socks_proxy_address, socks,
sizeof(vhost->socks_proxy_address));
p_colon = strchr(vhost->socks_proxy_address, ':');
if (!p_colon && !vhost->socks_proxy_port) {
lwsl_err("socks_proxy needs to be address:port\n");
return -1;
} else {
if (p_colon) {
*p_colon = '\0';
vhost->socks_proxy_port = atoi(p_colon + 1);
}
}
lwsl_debug("%s: Connections via Socks5 %s:%u\n", __func__,
vhost->socks_proxy_address, vhost->socks_proxy_port);
return 0;
bail:
return -1;
}
int
lws_socks5c_generate_msg(struct lws *wsi, enum socks_msg_type type,
ssize_t *msg_len)
{
struct lws_context *context = wsi->context;
struct lws_context_per_thread *pt = &context->pt[(int)wsi->tsi];
uint8_t *p = pt->serv_buf, *end = &p[context->pt_serv_buf_size];
ssize_t n, passwd_len;
short net_num;
char *cp;
switch (type) {
case SOCKS_MSG_GREETING:
if (lws_ptr_diff(end, p) < 4)
return 1;
/* socks version, version 5 only */
*p++ = SOCKS_VERSION_5;
/* number of methods */
*p++ = 2;
/* username password method */
*p++ = SOCKS_AUTH_USERNAME_PASSWORD;
/* no authentication method */
*p++ = SOCKS_AUTH_NO_AUTH;
break;
case SOCKS_MSG_USERNAME_PASSWORD:
n = strlen(wsi->vhost->socks_user);
passwd_len = strlen(wsi->vhost->socks_password);
if (n > 254 || passwd_len > 254)
return 1;
if (lws_ptr_diff(end, p) < 3 + n + passwd_len)
return 1;
/* the subnegotiation version */
*p++ = SOCKS_SUBNEGOTIATION_VERSION_1;
/* length of the user name */
*p++ = n;
/* user name */
memcpy(p, wsi->vhost->socks_user, n);
p += n;
/* length of the password */
*p++ = passwd_len;
/* password */
memcpy(p, wsi->vhost->socks_password, passwd_len);
p += passwd_len;
break;
case SOCKS_MSG_CONNECT:
n = strlen(wsi->stash->cis[CIS_ADDRESS]);
if (n > 254 || lws_ptr_diff(end, p) < 5 + n + 2)
return 1;
cp = (char *)&net_num;
/* socks version */
*p++ = SOCKS_VERSION_5;
/* socks command */
*p++ = SOCKS_COMMAND_CONNECT;
/* reserved */
*p++ = 0;
/* address type */
*p++ = SOCKS_ATYP_DOMAINNAME;
/* length of ---> */
*p++ = n;
/* the address we tell SOCKS proxy to connect to */
memcpy(p, wsi->stash->cis[CIS_ADDRESS], n);
p += n;
net_num = htons(wsi->c_port);
/* the port we tell SOCKS proxy to connect to */
*p++ = cp[0];
*p++ = cp[1];
break;
default:
return 1;
}
*msg_len = lws_ptr_diff(p, pt->serv_buf);
return 0;
}
int
lws_socks5c_ads_server(struct lws_vhost *vh,
const struct lws_context_creation_info *info)
{
/* socks proxy */
if (info->socks_proxy_address) {
/* override for backwards compatibility */
if (info->socks_proxy_port)
vh->socks_proxy_port = info->socks_proxy_port;
lws_set_socks(vh, info->socks_proxy_address);
return 0;
}
#ifdef LWS_HAVE_GETENV
{
char *p = getenv("socks_proxy");
if (p && strlen(p) > 0 && strlen(p) < 95)
lws_set_socks(vh, p);
}
#endif
return 0;
}
/*
* Returns 0 = nothing for caller to do, 1 = return wsi, -1 = goto failed
*/
int
lws_socks5c_greet(struct lws *wsi, const char **pcce)
{
struct lws_context_per_thread *pt = &wsi->context->pt[(int)wsi->tsi];
ssize_t plen;
int n;
/* socks proxy */
if (!wsi->vhost->socks_proxy_port)
return 0;
if (lws_socks5c_generate_msg(wsi, SOCKS_MSG_GREETING, &plen)) {
*pcce = "socks msg too large";
return -1;
}
// lwsl_hexdump_notice(pt->serv_buf, plen);
n = send(wsi->desc.sockfd, (char *)pt->serv_buf, plen,
MSG_NOSIGNAL);
if (n < 0) {
lwsl_debug("ERROR writing socks greeting\n");
*pcce = "socks write failed";
return -1;
}
lws_set_timeout(wsi, PENDING_TIMEOUT_AWAITING_SOCKS_GREETING_REPLY,
wsi->context->timeout_secs);
lwsi_set_state(wsi, LRS_WAITING_SOCKS_GREETING_REPLY);
return 1;
}
int
lws_socks5c_handle_state(struct lws *wsi, struct lws_pollfd *pollfd,
const char **pcce)
{
struct lws_context_per_thread *pt = &wsi->context->pt[(int)wsi->tsi];
int conn_mode = 0, pending_timeout = 0;
ssize_t len;
int n;
/* handle proxy hung up on us */
if (pollfd->revents & LWS_POLLHUP) {
lwsl_warn("SOCKS connection %p (fd=%d) dead\n",
(void *)wsi, pollfd->fd);
*pcce = "socks conn dead";
return LW5CHS_RET_BAIL3;
}
n = recv(wsi->desc.sockfd, pt->serv_buf,
wsi->context->pt_serv_buf_size, 0);
if (n < 0) {
if (LWS_ERRNO == LWS_EAGAIN) {
lwsl_debug("SOCKS read EAGAIN, retrying\n");
return LW5CHS_RET_RET0;
}
lwsl_err("ERROR reading from SOCKS socket\n");
*pcce = "socks recv fail";
return LW5CHS_RET_BAIL3;
}
// lwsl_hexdump_warn(pt->serv_buf, n);
switch (lwsi_state(wsi)) {
case LRS_WAITING_SOCKS_GREETING_REPLY:
if (pt->serv_buf[0] != SOCKS_VERSION_5)
goto socks_reply_fail;
if (pt->serv_buf[1] == SOCKS_AUTH_NO_AUTH) {
lwsl_client("SOCKS GR: No Auth Method\n");
if (lws_socks5c_generate_msg(wsi, SOCKS_MSG_CONNECT,
&len)) {
lwsl_err("%s: failed to generate connect msg\n",
__func__);
goto socks_send_msg_fail;
}
conn_mode = LRS_WAITING_SOCKS_CONNECT_REPLY;
pending_timeout =
PENDING_TIMEOUT_AWAITING_SOCKS_CONNECT_REPLY;
goto socks_send;
}
if (pt->serv_buf[1] == SOCKS_AUTH_USERNAME_PASSWORD) {
lwsl_client("SOCKS GR: User/Pw Method\n");
if (lws_socks5c_generate_msg(wsi,
SOCKS_MSG_USERNAME_PASSWORD,
&len))
goto socks_send_msg_fail;
conn_mode = LRS_WAITING_SOCKS_AUTH_REPLY;
pending_timeout =
PENDING_TIMEOUT_AWAITING_SOCKS_AUTH_REPLY;
goto socks_send;
}
goto socks_reply_fail;
case LRS_WAITING_SOCKS_AUTH_REPLY:
if (pt->serv_buf[0] != SOCKS_SUBNEGOTIATION_VERSION_1 ||
pt->serv_buf[1] !=
SOCKS_SUBNEGOTIATION_STATUS_SUCCESS)
goto socks_reply_fail;
lwsl_client("SOCKS password OK, sending connect\n");
if (lws_socks5c_generate_msg(wsi, SOCKS_MSG_CONNECT, &len)) {
socks_send_msg_fail:
*pcce = "socks gen msg fail";
return LW5CHS_RET_BAIL3;
}
conn_mode = LRS_WAITING_SOCKS_CONNECT_REPLY;
pending_timeout =
PENDING_TIMEOUT_AWAITING_SOCKS_CONNECT_REPLY;
socks_send:
// lwsl_hexdump_notice(pt->serv_buf, len);
n = send(wsi->desc.sockfd, (char *)pt->serv_buf, len,
MSG_NOSIGNAL);
if (n < 0) {
lwsl_debug("ERROR writing to socks proxy\n");
*pcce = "socks write fail";
return LW5CHS_RET_BAIL3;
}
lws_set_timeout(wsi, pending_timeout,
wsi->context->timeout_secs);
lwsi_set_state(wsi, conn_mode);
break;
socks_reply_fail:
lwsl_err("%s: socks reply: v%d, err %d\n", __func__,
pt->serv_buf[0], pt->serv_buf[1]);
*pcce = "socks reply fail";
return LW5CHS_RET_BAIL3;
case LRS_WAITING_SOCKS_CONNECT_REPLY:
if (pt->serv_buf[0] != SOCKS_VERSION_5 ||
pt->serv_buf[1] != SOCKS_REQUEST_REPLY_SUCCESS)
goto socks_reply_fail;
lwsl_client("%s: socks connect OK\n", __func__);
#if defined(LWS_ROLE_H1) || defined(LWS_ROLE_H2)
if (lwsi_role_http(wsi) &&
lws_hdr_simple_create(wsi, _WSI_TOKEN_CLIENT_PEER_ADDRESS,
wsi->vhost->socks_proxy_address)) {
*pcce = "socks connect fail";
return LW5CHS_RET_BAIL3;
}
#endif
wsi->c_port = wsi->vhost->socks_proxy_port;
/* clear his proxy connection timeout */
lws_set_timeout(wsi, NO_PENDING_TIMEOUT, 0);
return LW5CHS_RET_STARTHS;
default:
break;
}
return LW5CHS_RET_NOTHING;
}