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/*
* redir.c - Provide a transparent TCP proxy through remote shadowsocks
* server
*
* Copyright (C) 2013 - 2019, Max Lv <[email protected]>
*
* This file is part of the shadowsocks-libev.
*
* shadowsocks-libev 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 3 of the License, or
* (at your option) any later version.
*
* shadowsocks-libev is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with shadowsocks-libev; see the file COPYING. If not, see
* <http://www.gnu.org/licenses/>.
*/
#include <sys/stat.h>
#include <sys/types.h>
#include <arpa/inet.h>
#include <errno.h>
#include <fcntl.h>
#include <locale.h>
#include <netdb.h>
#include <netinet/in.h>
#include <pthread.h>
#include <signal.h>
#include <string.h>
#include <strings.h>
#include <time.h>
#include <unistd.h>
#include <getopt.h>
#include <limits.h>
#include <linux/if.h>
#include <linux/netfilter_ipv4.h>
#include <linux/netfilter_ipv6/ip6_tables.h>
#include <libcork/core.h>
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "plugin.h"
#include "netutils.h"
#include "utils.h"
#include "common.h"
#include "redir.h"
#ifndef EAGAIN
#define EAGAIN EWOULDBLOCK
#endif
#ifndef EWOULDBLOCK
#define EWOULDBLOCK EAGAIN
#endif
#ifndef IP6T_SO_ORIGINAL_DST
#define IP6T_SO_ORIGINAL_DST 80
#endif
#ifndef IP_TRANSPARENT
#define IP_TRANSPARENT 19
#endif
#ifndef IPV6_TRANSPARENT
#define IPV6_TRANSPARENT 75
#endif
static void accept_cb(EV_P_ ev_io *w, int revents);
static void server_recv_cb(EV_P_ ev_io *w, int revents);
static void server_send_cb(EV_P_ ev_io *w, int revents);
static void remote_recv_cb(EV_P_ ev_io *w, int revents);
static void remote_send_cb(EV_P_ ev_io *w, int revents);
static remote_t *new_remote(int fd, int timeout);
static server_t *new_server(int fd);
static void free_remote(remote_t *remote);
static void close_and_free_remote(EV_P_ remote_t *remote);
static void free_server(server_t *server);
static void close_and_free_server(EV_P_ server_t *server);
int verbose = 0;
int reuse_port = 0;
int tcp_incoming_sndbuf = 0;
int tcp_incoming_rcvbuf = 0;
int tcp_outgoing_sndbuf = 0;
int tcp_outgoing_rcvbuf = 0;
static crypto_t *crypto;
static int ipv6first = 0;
static int mode = TCP_ONLY;
#ifdef HAVE_SETRLIMIT
static int nofile = 0;
#endif
int fast_open = 0;
static int no_delay = 0;
static int ret_val = 0;
static struct ev_signal sigint_watcher;
static struct ev_signal sigterm_watcher;
static struct ev_signal sigchld_watcher;
static int tcp_tproxy = 0; /* use tproxy instead of redirect (for tcp) */
static int
getdestaddr(int fd, struct sockaddr_storage *destaddr)
{
socklen_t socklen = sizeof(*destaddr);
int error = 0;
if (tcp_tproxy) {
error = getsockname(fd, (void *)destaddr, &socklen);
} else {
error = getsockopt(fd, SOL_IPV6, IP6T_SO_ORIGINAL_DST, destaddr, &socklen);
if (error) { // Didn't find a proper way to detect IP version.
error = getsockopt(fd, SOL_IP, SO_ORIGINAL_DST, destaddr, &socklen);
}
}
if (error) {
return -1;
}
return 0;
}
int
setnonblocking(int fd)
{
int flags;
if (-1 == (flags = fcntl(fd, F_GETFL, 0))) {
flags = 0;
}
return fcntl(fd, F_SETFL, flags | O_NONBLOCK);
}
int
create_and_bind(const char *addr, const char *port)
{
struct addrinfo hints;
struct addrinfo *result, *rp;
int s, listen_sock;
memset(&hints, 0, sizeof(struct addrinfo));
hints.ai_family = AF_UNSPEC; /* Return IPv4 and IPv6 choices */
hints.ai_socktype = SOCK_STREAM; /* We want a TCP socket */
result = NULL;
s = getaddrinfo(addr, port, &hints, &result);
if (s != 0) {
LOGI("getaddrinfo: %s", gai_strerror(s));
return -1;
}
if (result == NULL) {
LOGE("Could not bind");
return -1;
}
for (rp = result; rp != NULL; rp = rp->ai_next) {
listen_sock = socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol);
if (listen_sock == -1) {
continue;
}
int opt = 1;
setsockopt(listen_sock, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt));
#ifdef SO_NOSIGPIPE
setsockopt(listen_sock, SOL_SOCKET, SO_NOSIGPIPE, &opt, sizeof(opt));
#endif
if (reuse_port) {
int err = set_reuseport(listen_sock);
if (err == 0) {
LOGI("tcp port reuse enabled");
}
}
if (tcp_tproxy) {
int level = 0, optname = 0;
if (rp->ai_family == AF_INET) {
level = IPPROTO_IP;
optname = IP_TRANSPARENT;
} else {
level = IPPROTO_IPV6;
optname = IPV6_TRANSPARENT;
}
if (setsockopt(listen_sock, level, optname, &opt, sizeof(opt)) != 0) {
ERROR("setsockopt IP_TRANSPARENT");
exit(EXIT_FAILURE);
}
LOGI("tcp tproxy mode enabled");
}
s = bind(listen_sock, rp->ai_addr, rp->ai_addrlen);
if (s == 0) {
/* We managed to bind successfully! */
break;
} else {
ERROR("bind");
}
close(listen_sock);
listen_sock = -1;
}
freeaddrinfo(result);
return listen_sock;
}
static void
server_recv_cb(EV_P_ ev_io *w, int revents)
{
server_ctx_t *server_recv_ctx = (server_ctx_t *)w;
server_t *server = server_recv_ctx->server;
remote_t *remote = server->remote;
ev_timer_stop(EV_A_ & server->delayed_connect_watcher);
ssize_t r = recv(server->fd, remote->buf->data + remote->buf->len,
SOCKET_BUF_SIZE - remote->buf->len, 0);
if (r == 0) {
// connection closed
close_and_free_remote(EV_A_ remote);
close_and_free_server(EV_A_ server);
return;
} else if (r == -1) {
if (errno == EAGAIN || errno == EWOULDBLOCK) {
// no data
// continue to wait for recv
return;
} else {
ERROR("server recv");
close_and_free_remote(EV_A_ remote);
close_and_free_server(EV_A_ server);
return;
}
}
remote->buf->len += r;
if (verbose) {
uint16_t port = 0;
char ipstr[INET6_ADDRSTRLEN];
memset(&ipstr, 0, INET6_ADDRSTRLEN);
if (AF_INET == server->destaddr.ss_family) {
struct sockaddr_in *sa = (struct sockaddr_in *)&(server->destaddr);
inet_ntop(AF_INET, &(sa->sin_addr), ipstr, INET_ADDRSTRLEN);
port = ntohs(sa->sin_port);
} else {
struct sockaddr_in6 *sa = (struct sockaddr_in6 *)&(server->destaddr);
inet_ntop(AF_INET6, &(sa->sin6_addr), ipstr, INET6_ADDRSTRLEN);
port = ntohs(sa->sin6_port);
}
LOGI("redir to %s:%d, len=%zu, recv=%zd", ipstr, port, remote->buf->len, r);
}
if (!remote->send_ctx->connected) {
ev_io_stop(EV_A_ & server_recv_ctx->io);
ev_io_start(EV_A_ & remote->send_ctx->io);
return;
}
int err = crypto->encrypt(remote->buf, server->e_ctx, SOCKET_BUF_SIZE);
if (err) {
LOGE("invalid password or cipher");
close_and_free_remote(EV_A_ remote);
close_and_free_server(EV_A_ server);
return;
}
int s = send(remote->fd, remote->buf->data, remote->buf->len, 0);
if (s == -1) {
if (errno == EAGAIN || errno == EWOULDBLOCK) {
// no data, wait for send
remote->buf->idx = 0;
ev_io_stop(EV_A_ & server_recv_ctx->io);
ev_io_start(EV_A_ & remote->send_ctx->io);
return;
} else {
ERROR("send");
close_and_free_remote(EV_A_ remote);
close_and_free_server(EV_A_ server);
return;
}
} else if (s < remote->buf->len) {
remote->buf->len -= s;
remote->buf->idx = s;
ev_io_stop(EV_A_ & server_recv_ctx->io);
ev_io_start(EV_A_ & remote->send_ctx->io);
return;
} else {
remote->buf->idx = 0;
remote->buf->len = 0;
}
}
static void
server_send_cb(EV_P_ ev_io *w, int revents)
{
server_ctx_t *server_send_ctx = (server_ctx_t *)w;
server_t *server = server_send_ctx->server;
remote_t *remote = server->remote;
if (server->buf->len == 0) {
// close and free
close_and_free_remote(EV_A_ remote);
close_and_free_server(EV_A_ server);
return;
} else {
// has data to send
ssize_t s = send(server->fd, server->buf->data + server->buf->idx,
server->buf->len, 0);
if (s == -1) {
if (errno != EAGAIN && errno != EWOULDBLOCK) {
ERROR("send");
close_and_free_remote(EV_A_ remote);
close_and_free_server(EV_A_ server);
}
return;
} else if (s < server->buf->len) {
// partly sent, move memory, wait for the next time to send
server->buf->len -= s;
server->buf->idx += s;
return;
} else {
// all sent out, wait for reading
server->buf->len = 0;
server->buf->idx = 0;
ev_io_stop(EV_A_ & server_send_ctx->io);
ev_io_start(EV_A_ & remote->recv_ctx->io);
}
}
}
static void
delayed_connect_cb(EV_P_ ev_timer *watcher, int revents)
{
server_t *server = cork_container_of(watcher, server_t,
delayed_connect_watcher);
remote_t *remote = server->remote;
int r = connect(remote->fd, remote->addr,
get_sockaddr_len(remote->addr));
remote->addr = NULL;
if (r == -1 && errno != CONNECT_IN_PROGRESS) {
ERROR("connect");
close_and_free_remote(EV_A_ remote);
close_and_free_server(EV_A_ server);
return;
} else {
// listen to remote connected event
ev_io_start(EV_A_ & remote->send_ctx->io);
ev_timer_start(EV_A_ & remote->send_ctx->watcher);
}
}
static void
remote_timeout_cb(EV_P_ ev_timer *watcher, int revents)
{
remote_ctx_t *remote_ctx
= cork_container_of(watcher, remote_ctx_t, watcher);
remote_t *remote = remote_ctx->remote;
server_t *server = remote->server;
ev_timer_stop(EV_A_ watcher);
close_and_free_remote(EV_A_ remote);
close_and_free_server(EV_A_ server);
}
static void
remote_recv_cb(EV_P_ ev_io *w, int revents)
{
remote_ctx_t *remote_recv_ctx = (remote_ctx_t *)w;
remote_t *remote = remote_recv_ctx->remote;
server_t *server = remote->server;
ssize_t r = recv(remote->fd, server->buf->data, SOCKET_BUF_SIZE, 0);
if (r == 0) {
// connection closed
close_and_free_remote(EV_A_ remote);
close_and_free_server(EV_A_ server);
return;
} else if (r == -1) {
if (errno == EAGAIN || errno == EWOULDBLOCK) {
// no data
// continue to wait for recv
return;
} else {
ERROR("remote recv");
close_and_free_remote(EV_A_ remote);
close_and_free_server(EV_A_ server);
return;
}
}
server->buf->len = r;
int err = crypto->decrypt(server->buf, server->d_ctx, SOCKET_BUF_SIZE);
if (err == CRYPTO_ERROR) {
LOGE("invalid password or cipher");
close_and_free_remote(EV_A_ remote);
close_and_free_server(EV_A_ server);
return;
} else if (err == CRYPTO_NEED_MORE) {
return; // Wait for more
}
int s = send(server->fd, server->buf->data, server->buf->len, 0);
if (s == -1) {
if (errno == EAGAIN || errno == EWOULDBLOCK) {
// no data, wait for send
server->buf->idx = 0;
ev_io_stop(EV_A_ & remote_recv_ctx->io);
ev_io_start(EV_A_ & server->send_ctx->io);
} else {
ERROR("send");
close_and_free_remote(EV_A_ remote);
close_and_free_server(EV_A_ server);
return;
}
} else if (s < server->buf->len) {
server->buf->len -= s;
server->buf->idx = s;
ev_io_stop(EV_A_ & remote_recv_ctx->io);
ev_io_start(EV_A_ & server->send_ctx->io);
}
// Disable TCP_NODELAY after the first response are sent
if (!remote->recv_ctx->connected && !no_delay) {
int opt = 0;
setsockopt(server->fd, SOL_TCP, TCP_NODELAY, &opt, sizeof(opt));
setsockopt(remote->fd, SOL_TCP, TCP_NODELAY, &opt, sizeof(opt));
}
remote->recv_ctx->connected = 1;
}
static void
remote_send_cb(EV_P_ ev_io *w, int revents)
{
remote_ctx_t *remote_send_ctx = (remote_ctx_t *)w;
remote_t *remote = remote_send_ctx->remote;
server_t *server = remote->server;
ev_timer_stop(EV_A_ & remote_send_ctx->watcher);
if (!remote_send_ctx->connected) {
int r = 0;
if (remote->addr == NULL) {
struct sockaddr_storage addr;
memset(&addr, 0, sizeof(struct sockaddr_storage));
socklen_t len = sizeof addr;
r = getpeername(remote->fd, (struct sockaddr *)&addr, &len);
}
if (r == 0) {
remote_send_ctx->connected = 1;
ev_io_stop(EV_A_ & remote_send_ctx->io);
ev_io_stop(EV_A_ & server->recv_ctx->io);
ev_io_start(EV_A_ & remote->recv_ctx->io);
// send destaddr
buffer_t ss_addr_to_send;
buffer_t *abuf = &ss_addr_to_send;
balloc(abuf, SOCKET_BUF_SIZE);
if (AF_INET6 == server->destaddr.ss_family) { // IPv6
abuf->data[abuf->len++] = 4; // Type 4 is IPv6 address
size_t in6_addr_len = sizeof(struct in6_addr);
memcpy(abuf->data + abuf->len,
&(((struct sockaddr_in6 *)&(server->destaddr))->sin6_addr),
in6_addr_len);
abuf->len += in6_addr_len;
memcpy(abuf->data + abuf->len,
&(((struct sockaddr_in6 *)&(server->destaddr))->sin6_port),
2);
} else { // IPv4
abuf->data[abuf->len++] = 1; // Type 1 is IPv4 address
size_t in_addr_len = sizeof(struct in_addr);
memcpy(abuf->data + abuf->len,
&((struct sockaddr_in *)&(server->destaddr))->sin_addr, in_addr_len);
abuf->len += in_addr_len;
memcpy(abuf->data + abuf->len,
&((struct sockaddr_in *)&(server->destaddr))->sin_port, 2);
}
abuf->len += 2;
int err = crypto->encrypt(abuf, server->e_ctx, SOCKET_BUF_SIZE);
if (err) {
LOGE("invalid password or cipher");
bfree(abuf);
close_and_free_remote(EV_A_ remote);
close_and_free_server(EV_A_ server);
return;
}
err = crypto->encrypt(remote->buf, server->e_ctx, SOCKET_BUF_SIZE);
if (err) {
LOGE("invalid password or cipher");
bfree(abuf);
close_and_free_remote(EV_A_ remote);
close_and_free_server(EV_A_ server);
return;
}
bprepend(remote->buf, abuf, SOCKET_BUF_SIZE);
bfree(abuf);
} else {
ERROR("getpeername");
// not connected
close_and_free_remote(EV_A_ remote);
close_and_free_server(EV_A_ server);
return;
}
}
if (remote->buf->len == 0) {
// close and free
close_and_free_remote(EV_A_ remote);
close_and_free_server(EV_A_ server);
return;
} else {
// has data to send
int s = -1;
if (remote->addr != NULL) {
#if defined(TCP_FASTOPEN_CONNECT)
int optval = 1;
if (setsockopt(remote->fd, IPPROTO_TCP, TCP_FASTOPEN_CONNECT,
(void *)&optval, sizeof(optval)) < 0)
FATAL("failed to set TCP_FASTOPEN_CONNECT");
s = connect(remote->fd, remote->addr, get_sockaddr_len(remote->addr));
if (s == 0)
s = send(remote->fd, remote->buf->data, remote->buf->len, 0);
#elif defined(MSG_FASTOPEN)
s = sendto(remote->fd, remote->buf->data + remote->buf->idx,
remote->buf->len, MSG_FASTOPEN, remote->addr,
get_sockaddr_len(remote->addr));
#else
FATAL("tcp fast open is not supported on this platform");
#endif
remote->addr = NULL;
if (s == -1) {
if (errno == CONNECT_IN_PROGRESS) {
ev_io_start(EV_A_ & remote_send_ctx->io);
ev_timer_start(EV_A_ & remote_send_ctx->watcher);
} else {
if (errno == EOPNOTSUPP || errno == EPROTONOSUPPORT ||
errno == ENOPROTOOPT) {
fast_open = 0;
LOGE("fast open is not supported on this platform");
} else {
ERROR("fast_open_connect");
}
close_and_free_remote(EV_A_ remote);
close_and_free_server(EV_A_ server);
}
return;
}
} else {
s = send(remote->fd, remote->buf->data + remote->buf->idx,
remote->buf->len, 0);
}
if (s == -1) {
if (errno != EAGAIN && errno != EWOULDBLOCK) {
ERROR("send");
// close and free
close_and_free_remote(EV_A_ remote);
close_and_free_server(EV_A_ server);
}
return;
} else if (s < remote->buf->len) {
// partly sent, move memory, wait for the next time to send
remote->buf->len -= s;
remote->buf->idx += s;
ev_io_start(EV_A_ & remote_send_ctx->io);
return;
} else {
// all sent out, wait for reading
remote->buf->len = 0;
remote->buf->idx = 0;
ev_io_stop(EV_A_ & remote_send_ctx->io);
ev_io_start(EV_A_ & server->recv_ctx->io);
}
}
}
static remote_t *
new_remote(int fd, int timeout)
{
remote_t *remote = ss_malloc(sizeof(remote_t));
memset(remote, 0, sizeof(remote_t));
remote->recv_ctx = ss_malloc(sizeof(remote_ctx_t));
remote->send_ctx = ss_malloc(sizeof(remote_ctx_t));
remote->buf = ss_malloc(sizeof(buffer_t));
balloc(remote->buf, SOCKET_BUF_SIZE);
memset(remote->recv_ctx, 0, sizeof(remote_ctx_t));
memset(remote->send_ctx, 0, sizeof(remote_ctx_t));
remote->fd = fd;
remote->recv_ctx->remote = remote;
remote->recv_ctx->connected = 0;
remote->send_ctx->remote = remote;
remote->send_ctx->connected = 0;
ev_io_init(&remote->recv_ctx->io, remote_recv_cb, fd, EV_READ);
ev_io_init(&remote->send_ctx->io, remote_send_cb, fd, EV_WRITE);
ev_timer_init(&remote->send_ctx->watcher, remote_timeout_cb,
min(MAX_CONNECT_TIMEOUT, timeout), 0);
return remote;
}
static void
free_remote(remote_t *remote)
{
if (remote->server != NULL) {
remote->server->remote = NULL;
}
if (remote->buf != NULL) {
bfree(remote->buf);
ss_free(remote->buf);
}
ss_free(remote->recv_ctx);
ss_free(remote->send_ctx);
ss_free(remote);
}
static void
close_and_free_remote(EV_P_ remote_t *remote)
{
if (remote != NULL) {
ev_timer_stop(EV_A_ & remote->send_ctx->watcher);
ev_io_stop(EV_A_ & remote->send_ctx->io);
ev_io_stop(EV_A_ & remote->recv_ctx->io);
close(remote->fd);
free_remote(remote);
}
}
static server_t *
new_server(int fd)
{
server_t *server = ss_malloc(sizeof(server_t));
memset(server, 0, sizeof(server_t));
server->recv_ctx = ss_malloc(sizeof(server_ctx_t));
server->send_ctx = ss_malloc(sizeof(server_ctx_t));
server->buf = ss_malloc(sizeof(buffer_t));
balloc(server->buf, SOCKET_BUF_SIZE);
memset(server->recv_ctx, 0, sizeof(server_ctx_t));
memset(server->send_ctx, 0, sizeof(server_ctx_t));
server->fd = fd;
server->recv_ctx->server = server;
server->recv_ctx->connected = 0;
server->send_ctx->server = server;
server->send_ctx->connected = 0;
server->e_ctx = ss_malloc(sizeof(cipher_ctx_t));
server->d_ctx = ss_malloc(sizeof(cipher_ctx_t));
crypto->ctx_init(crypto->cipher, server->e_ctx, 1);
crypto->ctx_init(crypto->cipher, server->d_ctx, 0);
ev_io_init(&server->recv_ctx->io, server_recv_cb, fd, EV_READ);
ev_io_init(&server->send_ctx->io, server_send_cb, fd, EV_WRITE);
ev_timer_init(&server->delayed_connect_watcher, delayed_connect_cb, 0.05,
0);
return server;
}
static void
free_server(server_t *server)
{
if (server->remote != NULL) {
server->remote->server = NULL;
}
if (server->e_ctx != NULL) {
crypto->ctx_release(server->e_ctx);
ss_free(server->e_ctx);
}
if (server->d_ctx != NULL) {
crypto->ctx_release(server->d_ctx);
ss_free(server->d_ctx);
}
if (server->buf != NULL) {
bfree(server->buf);
ss_free(server->buf);
}
ss_free(server->recv_ctx);
ss_free(server->send_ctx);
ss_free(server);
}
static void
close_and_free_server(EV_P_ server_t *server)
{
if (server != NULL) {
ev_io_stop(EV_A_ & server->send_ctx->io);
ev_io_stop(EV_A_ & server->recv_ctx->io);
ev_timer_stop(EV_A_ & server->delayed_connect_watcher);
close(server->fd);
free_server(server);
}
}
static void
accept_cb(EV_P_ ev_io *w, int revents)
{
listen_ctx_t *listener = (listen_ctx_t *)w;
struct sockaddr_storage destaddr;
memset(&destaddr, 0, sizeof(struct sockaddr_storage));
int err;
int serverfd = accept(listener->fd, NULL, NULL);
if (serverfd == -1) {
ERROR("accept");
return;
}
err = getdestaddr(serverfd, &destaddr);
if (err) {
ERROR("getdestaddr");
return;
}
setnonblocking(serverfd);
int opt = 1;
setsockopt(serverfd, SOL_TCP, TCP_NODELAY, &opt, sizeof(opt));
#ifdef SO_NOSIGPIPE
setsockopt(serverfd, SOL_SOCKET, SO_NOSIGPIPE, &opt, sizeof(opt));
#endif
if (tcp_incoming_sndbuf > 0) {
setsockopt(serverfd, SOL_SOCKET, SO_SNDBUF, &tcp_incoming_sndbuf, sizeof(int));
}
if (tcp_incoming_rcvbuf > 0) {
setsockopt(serverfd, SOL_SOCKET, SO_RCVBUF, &tcp_incoming_rcvbuf, sizeof(int));
}
int index = rand() % listener->remote_num;
struct sockaddr *remote_addr = listener->remote_addr[index];
int remotefd = socket(remote_addr->sa_family, SOCK_STREAM, IPPROTO_TCP);
if (remotefd == -1) {
ERROR("socket");
return;
}
// Set flags
setsockopt(remotefd, SOL_TCP, TCP_NODELAY, &opt, sizeof(opt));
#ifdef SO_NOSIGPIPE
setsockopt(remotefd, SOL_SOCKET, SO_NOSIGPIPE, &opt, sizeof(opt));
#endif
// Enable TCP keepalive feature
int keepAlive = 1;
int keepIdle = 40;
int keepInterval = 20;
int keepCount = 5;
setsockopt(remotefd, SOL_SOCKET, SO_KEEPALIVE, (void *)&keepAlive, sizeof(keepAlive));
setsockopt(remotefd, SOL_TCP, TCP_KEEPIDLE, (void *)&keepIdle, sizeof(keepIdle));
setsockopt(remotefd, SOL_TCP, TCP_KEEPINTVL, (void *)&keepInterval, sizeof(keepInterval));
setsockopt(remotefd, SOL_TCP, TCP_KEEPCNT, (void *)&keepCount, sizeof(keepCount));
// Set non blocking
setnonblocking(remotefd);
if (listener->tos >= 0) {
int rc = setsockopt(remotefd, IPPROTO_IP, IP_TOS, &listener->tos, sizeof(listener->tos));
if (rc < 0 && errno != ENOPROTOOPT) {
LOGE("setting ipv4 dscp failed: %d", errno);
}
rc = setsockopt(remotefd, IPPROTO_IPV6, IPV6_TCLASS, &listener->tos, sizeof(listener->tos));
if (rc < 0 && errno != ENOPROTOOPT) {
LOGE("setting ipv6 dscp failed: %d", errno);
}
}
// Enable MPTCP
if (listener->mptcp > 1) {
int err = setsockopt(remotefd, SOL_TCP, listener->mptcp, &opt, sizeof(opt));
if (err == -1) {
ERROR("failed to enable multipath TCP");
}
} else if (listener->mptcp == 1) {
int i = 0;
while ((listener->mptcp = mptcp_enabled_values[i]) > 0) {
int err = setsockopt(remotefd, SOL_TCP, listener->mptcp, &opt, sizeof(opt));
if (err != -1) {
break;
}
i++;
}
if (listener->mptcp == 0) {
ERROR("failed to enable multipath TCP");
}
}
if (tcp_outgoing_sndbuf > 0) {
setsockopt(remotefd, SOL_SOCKET, SO_SNDBUF, &tcp_outgoing_sndbuf, sizeof(int));
}
if (tcp_outgoing_rcvbuf > 0) {
setsockopt(remotefd, SOL_SOCKET, SO_RCVBUF, &tcp_outgoing_rcvbuf, sizeof(int));
}
server_t *server = new_server(serverfd);
remote_t *remote = new_remote(remotefd, listener->timeout);
server->remote = remote;
remote->server = server;
server->destaddr = destaddr;
if (fast_open) {
// save remote addr for fast open
remote->addr = remote_addr;
ev_timer_start(EV_A_ & server->delayed_connect_watcher);
} else {
int r = connect(remotefd, remote_addr, get_sockaddr_len(remote_addr));
if (r == -1 && errno != CONNECT_IN_PROGRESS) {
ERROR("connect");
close_and_free_remote(EV_A_ remote);
close_and_free_server(EV_A_ server);
return;
}
// listen to remote connected event
ev_io_start(EV_A_ & remote->send_ctx->io);
ev_timer_start(EV_A_ & remote->send_ctx->watcher);
}
ev_io_start(EV_A_ & server->recv_ctx->io);
}
static void
signal_cb(EV_P_ ev_signal *w, int revents)
{
if (revents & EV_SIGNAL) {
switch (w->signum) {
case SIGCHLD:
if (!is_plugin_running()) {
LOGE("plugin service exit unexpectedly");
ret_val = -1;
} else
return;
case SIGINT:
case SIGTERM:
ev_signal_stop(EV_DEFAULT, &sigint_watcher);
ev_signal_stop(EV_DEFAULT, &sigterm_watcher);
ev_signal_stop(EV_DEFAULT, &sigchld_watcher);
ev_unloop(EV_A_ EVUNLOOP_ALL);
}
}
}
int
main(int argc, char **argv)
{
srand(time(NULL));
int i, c;
int pid_flags = 0;
int mptcp = 0;
int mtu = 0;
char *user = NULL;
char *local_port = NULL;
char *local_addr = NULL;
char *password = NULL;
char *key = NULL;
char *timeout = NULL;
char *method = NULL;
char *pid_path = NULL;
char *conf_path = NULL;
char *plugin = NULL;
char *plugin_opts = NULL;
char *plugin_host = NULL;
char *plugin_port = NULL;
char tmp_port[8];
int dscp_num = 0;
ss_dscp_t *dscp = NULL;
int remote_num = 0;
char *remote_port = NULL;
ss_addr_t remote_addr[MAX_REMOTE_NUM];
memset(remote_addr, 0, sizeof(ss_addr_t) * MAX_REMOTE_NUM);
static struct option long_options[] = {
{ "fast-open", no_argument, NULL, GETOPT_VAL_FAST_OPEN },
{ "mtu", required_argument, NULL, GETOPT_VAL_MTU },
{ "mptcp", no_argument, NULL, GETOPT_VAL_MPTCP },
{ "plugin", required_argument, NULL, GETOPT_VAL_PLUGIN },
{ "plugin-opts", required_argument, NULL, GETOPT_VAL_PLUGIN_OPTS },
{ "reuse-port", no_argument, NULL, GETOPT_VAL_REUSE_PORT },
{ "tcp-incoming-sndbuf", required_argument, NULL, GETOPT_VAL_TCP_INCOMING_SNDBUF },
{ "tcp-incoming-rcvbuf", required_argument, NULL, GETOPT_VAL_TCP_INCOMING_RCVBUF },
{ "tcp-outgoing-sndbuf", required_argument, NULL, GETOPT_VAL_TCP_OUTGOING_SNDBUF },
{ "tcp-outgoing-rcvbuf", required_argument, NULL, GETOPT_VAL_TCP_OUTGOING_RCVBUF },
{ "no-delay", no_argument, NULL, GETOPT_VAL_NODELAY },
{ "password", required_argument, NULL, GETOPT_VAL_PASSWORD },
{ "key", required_argument, NULL, GETOPT_VAL_KEY },
{ "help", no_argument, NULL, GETOPT_VAL_HELP },
{ NULL, 0, NULL, 0 }
};
opterr = 0;
USE_TTY();
while ((c = getopt_long(argc, argv, "f:s:p:l:k:t:m:c:b:a:n:huUTv6A",
long_options, NULL)) != -1) {
switch (c) {
case GETOPT_VAL_FAST_OPEN:
fast_open = 1;
break;
case GETOPT_VAL_MTU:
mtu = atoi(optarg);
LOGI("set MTU to %d", mtu);
break;
case GETOPT_VAL_MPTCP:
mptcp = 1;
LOGI("enable multipath TCP");
break;
case GETOPT_VAL_NODELAY:
no_delay = 1;
LOGI("enable TCP no-delay");
break;
case GETOPT_VAL_PLUGIN:
plugin = optarg;
break;
case GETOPT_VAL_PLUGIN_OPTS:
plugin_opts = optarg;
break;
case GETOPT_VAL_KEY:
key = optarg;
break;
case GETOPT_VAL_REUSE_PORT:
reuse_port = 1;
break;
case GETOPT_VAL_TCP_INCOMING_SNDBUF:
tcp_incoming_sndbuf = atoi(optarg);
break;
case GETOPT_VAL_TCP_INCOMING_RCVBUF:
tcp_incoming_rcvbuf = atoi(optarg);
break;
case GETOPT_VAL_TCP_OUTGOING_SNDBUF:
tcp_outgoing_sndbuf = atoi(optarg);
break;
case GETOPT_VAL_TCP_OUTGOING_RCVBUF:
tcp_outgoing_rcvbuf = atoi(optarg);
break;
case 's':
if (remote_num < MAX_REMOTE_NUM) {
parse_addr(optarg, &remote_addr[remote_num++]);
}
break;
case 'p':
remote_port = optarg;
break;
case 'l':
local_port = optarg;
break;
case GETOPT_VAL_PASSWORD:
case 'k':
password = optarg;
break;
case 'f':
pid_flags = 1;
pid_path = optarg;
break;
case 't':
timeout = optarg;
break;
case 'm':
method = optarg;
break;
case 'c':
conf_path = optarg;
break;
case 'b':
local_addr = optarg;
break;
case 'a':
user = optarg;
break;
#ifdef HAVE_SETRLIMIT
case 'n':
nofile = atoi(optarg);
break;
#endif
case 'u':
mode = TCP_AND_UDP;
break;
case 'U':
mode = UDP_ONLY;
break;
case 'T':
tcp_tproxy = 1;
break;
case 'v':
verbose = 1;
break;
case GETOPT_VAL_HELP:
case 'h':
usage();
exit(EXIT_SUCCESS);
case '6':
ipv6first = 1;
break;
case 'A':
FATAL("One time auth has been deprecated. Try AEAD ciphers instead.");
break;
case '?':
// The option character is not recognized.
LOGE("Unrecognized option: %s", optarg);
opterr = 1;
break;
}
}
if (opterr) {
usage();
exit(EXIT_FAILURE);
}
if (argc == 1) {
if (conf_path == NULL) {
conf_path = get_default_conf();
}
}
if (conf_path != NULL) {
jconf_t *conf = read_jconf(conf_path);
if (remote_num == 0) {
remote_num = conf->remote_num;
for (i = 0; i < remote_num; i++)
remote_addr[i] = conf->remote_addr[i];
}
if (remote_port == NULL) {
remote_port = conf->remote_port;
}
if (local_addr == NULL) {
local_addr = conf->local_addr;
}
if (local_port == NULL) {
local_port = conf->local_port;
}
if (password == NULL) {
password = conf->password;
}
if (key == NULL) {
key = conf->key;
}
if (method == NULL) {
method = conf->method;
}
if (timeout == NULL) {
timeout = conf->timeout;
}
if (user == NULL) {
user = conf->user;
}
if (plugin == NULL) {
plugin = conf->plugin;
}
if (plugin_opts == NULL) {
plugin_opts = conf->plugin_opts;
}
if (mode == TCP_ONLY) {
mode = conf->mode;
}
if (tcp_tproxy == 0) {
tcp_tproxy = conf->tcp_tproxy;
}
if (mtu == 0) {
mtu = conf->mtu;
}
if (mptcp == 0) {
mptcp = conf->mptcp;
}
if (no_delay == 0) {
no_delay = conf->no_delay;
}
if (reuse_port == 0) {
reuse_port = conf->reuse_port;
}
if (tcp_incoming_sndbuf == 0) {
tcp_incoming_sndbuf = conf->tcp_incoming_sndbuf;
}
if (tcp_incoming_rcvbuf == 0) {
tcp_incoming_rcvbuf = conf->tcp_incoming_rcvbuf;
}
if (tcp_outgoing_sndbuf == 0) {
tcp_outgoing_sndbuf = conf->tcp_outgoing_sndbuf;
}
if (tcp_outgoing_rcvbuf == 0) {
tcp_outgoing_rcvbuf = conf->tcp_outgoing_rcvbuf;
}
if (fast_open == 0) {
fast_open = conf->fast_open;
}
#ifdef HAVE_SETRLIMIT
if (nofile == 0) {
nofile = conf->nofile;
}
#endif
if (ipv6first == 0) {
ipv6first = conf->ipv6_first;
}
dscp_num = conf->dscp_num;
dscp = conf->dscp;
}
if (remote_num == 0 || remote_port == NULL || local_port == NULL
|| (password == NULL && key == NULL)) {
usage();
exit(EXIT_FAILURE);
}
if (plugin != NULL) {
uint16_t port = get_local_port();
if (port == 0) {
FATAL("failed to find a free port");
}
snprintf(tmp_port, 8, "%d", port);
if (is_ipv6only(remote_addr, remote_num, ipv6first)) {
plugin_host = "::1";
} else {
plugin_host = "127.0.0.1";
}
plugin_port = tmp_port;
LOGI("plugin \"%s\" enabled", plugin);
}
if (method == NULL) {
method = "chacha20-ietf-poly1305";
}
if (timeout == NULL) {
timeout = "600";
}
#ifdef HAVE_SETRLIMIT
/*
* no need to check the return value here since we will show
* the user an error message if setrlimit(2) fails
*/
if (nofile > 1024) {
if (verbose) {
LOGI("setting NOFILE to %d", nofile);
}
set_nofile(nofile);
}
#endif
if (local_addr == NULL) {
if (is_ipv6only(remote_addr, remote_num, ipv6first)) {
local_addr = "::1";
} else {
local_addr = "127.0.0.1";
}
}
if (fast_open == 1) {
#ifdef TCP_FASTOPEN
LOGI("using tcp fast open");
#else
LOGE("tcp fast open is not supported by this environment");
fast_open = 0;
#endif
}
USE_SYSLOG(argv[0], pid_flags);
if (pid_flags) {
daemonize(pid_path);
}
if (no_delay) {
LOGI("enable TCP no-delay");
}
if (ipv6first) {
LOGI("resolving hostname to IPv6 address first");
}
if (tcp_incoming_sndbuf != 0 && tcp_incoming_sndbuf < SOCKET_BUF_SIZE) {
tcp_incoming_sndbuf = 0;
}
if (tcp_incoming_sndbuf != 0) {
LOGI("set TCP incoming connection send buffer size to %d", tcp_incoming_sndbuf);
}
if (tcp_incoming_rcvbuf != 0 && tcp_incoming_rcvbuf < SOCKET_BUF_SIZE) {
tcp_incoming_rcvbuf = 0;
}
if (tcp_incoming_rcvbuf != 0) {
LOGI("set TCP incoming connection receive buffer size to %d", tcp_incoming_rcvbuf);
}
if (tcp_outgoing_sndbuf != 0 && tcp_outgoing_sndbuf < SOCKET_BUF_SIZE) {
tcp_outgoing_sndbuf = 0;
}
if (tcp_outgoing_sndbuf != 0) {
LOGI("set TCP outgoing connection send buffer size to %d", tcp_outgoing_sndbuf);
}
if (tcp_outgoing_rcvbuf != 0 && tcp_outgoing_rcvbuf < SOCKET_BUF_SIZE) {
tcp_outgoing_rcvbuf = 0;
}
if (tcp_outgoing_rcvbuf != 0) {
LOGI("set TCP outgoing connection receive buffer size to %d", tcp_outgoing_rcvbuf);
}
if (plugin != NULL) {
int len = 0;
size_t buf_size = 256 * remote_num;
char *remote_str = ss_malloc(buf_size);
snprintf(remote_str, buf_size, "%s", remote_addr[0].host);
for (int i = 1; i < remote_num; i++) {
snprintf(remote_str + len, buf_size - len, "|%s", remote_addr[i].host);
len = strlen(remote_str);
}
int err = start_plugin(plugin, plugin_opts, remote_str,
remote_port, plugin_host, plugin_port, MODE_CLIENT);
if (err) {
FATAL("failed to start the plugin");
}
}
// ignore SIGPIPE
signal(SIGPIPE, SIG_IGN);
signal(SIGABRT, SIG_IGN);
ev_signal_init(&sigint_watcher, signal_cb, SIGINT);
ev_signal_init(&sigterm_watcher, signal_cb, SIGTERM);
ev_signal_init(&sigchld_watcher, signal_cb, SIGCHLD);
ev_signal_start(EV_DEFAULT, &sigint_watcher);
ev_signal_start(EV_DEFAULT, &sigterm_watcher);
ev_signal_start(EV_DEFAULT, &sigchld_watcher);
// Setup keys
LOGI("initializing ciphers... %s", method);
crypto = crypto_init(password, key, method);
if (crypto == NULL)
FATAL("failed to initialize ciphers");
// Setup proxy context
struct listen_ctx listen_ctx;
memset(&listen_ctx, 0, sizeof(struct listen_ctx));
listen_ctx.remote_num = remote_num;
listen_ctx.remote_addr = ss_malloc(sizeof(struct sockaddr *) * remote_num);
memset(listen_ctx.remote_addr, 0, sizeof(struct sockaddr *) * remote_num);
for (i = 0; i < remote_num; i++) {
char *host = remote_addr[i].host;
char *port = remote_addr[i].port == NULL ? remote_port :
remote_addr[i].port;
if (plugin != NULL) {
host = plugin_host;
port = plugin_port;
}
struct sockaddr_storage *storage = ss_malloc(sizeof(struct sockaddr_storage));
memset(storage, 0, sizeof(struct sockaddr_storage));
if (get_sockaddr(host, port, storage, 1, ipv6first) == -1) {
FATAL("failed to resolve the provided hostname");
}
listen_ctx.remote_addr[i] = (struct sockaddr *)storage;
if (plugin != NULL)
break;
}
listen_ctx.timeout = atoi(timeout);
listen_ctx.mptcp = mptcp;
struct ev_loop *loop = EV_DEFAULT;
listen_ctx_t *listen_ctx_current = &listen_ctx;
do {
if (listen_ctx_current->tos) {
LOGI("listening at %s:%s (TOS 0x%x)", local_addr, local_port, listen_ctx_current->tos);
} else {
LOGI("listening at %s:%s", local_addr, local_port);
}
if (mode != UDP_ONLY) {
// Setup socket
int listenfd;
listenfd = create_and_bind(local_addr, local_port);
if (listenfd == -1) {
FATAL("bind() error");
}
if (listen(listenfd, SOMAXCONN) == -1) {
FATAL("listen() error");
}
setnonblocking(listenfd);
listen_ctx_current->fd = listenfd;
ev_io_init(&listen_ctx_current->io, accept_cb, listenfd, EV_READ);
ev_io_start(loop, &listen_ctx_current->io);
}
// Setup UDP
if (mode != TCP_ONLY) {
LOGI("UDP relay enabled");
char *host = remote_addr[0].host;
char *port = remote_addr[0].port == NULL ? remote_port : remote_addr[0].port;
struct sockaddr_storage *storage = ss_malloc(sizeof(struct sockaddr_storage));
memset(storage, 0, sizeof(struct sockaddr_storage));
if (get_sockaddr(host, port, storage, 1, ipv6first) == -1) {
FATAL("failed to resolve the provided hostname");
}
struct sockaddr *addr = (struct sockaddr *)storage;
init_udprelay(local_addr, local_port, addr,
get_sockaddr_len(addr), mtu, crypto, listen_ctx_current->timeout, NULL);
}
if (mode == UDP_ONLY) {
LOGI("TCP relay disabled");
}
// Handle additionals TOS/DSCP listening ports
if (dscp_num > 0) {
listen_ctx_current = (listen_ctx_t *)ss_malloc(sizeof(listen_ctx_t));
listen_ctx_current = memcpy(listen_ctx_current, &listen_ctx, sizeof(listen_ctx_t));
local_port = dscp[dscp_num - 1].port;
listen_ctx_current->tos = dscp[dscp_num - 1].dscp << 2;
}
} while (dscp_num-- > 0);
// setuid
if (user != NULL && !run_as(user)) {
FATAL("failed to switch user");
}
if (geteuid() == 0) {
LOGI("running from root user");
}
ev_run(loop, 0);
if (plugin != NULL) {
stop_plugin();
}
return ret_val;
}