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/*
* server.c - Provide shadowsocks service
*
* Copyright (C) 2013 - 2015, Max Lv <max.c.lv@gmail.com>
*
* 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/>.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <sys/stat.h>
#include <sys/types.h>
#include <fcntl.h>
#include <locale.h>
#include <signal.h>
#include <string.h>
#include <strings.h>
#include <time.h>
#include <unistd.h>
#include <getopt.h>
#include <math.h>
#ifndef __MINGW32__
#include <netdb.h>
#include <errno.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <pthread.h>
#include <sys/un.h>
#endif
#include <libcork/core.h>
#include <udns.h>
#ifdef __MINGW32__
#include "win32.h"
#endif
#if defined(HAVE_SYS_IOCTL_H) && defined(HAVE_NET_IF_H) && defined(__linux__)
#include <net/if.h>
#include <sys/ioctl.h>
#define SET_INTERFACE
#endif
#include "netutils.h"
#include "utils.h"
#include "acl.h"
#include "server.h"
#ifndef EAGAIN
#define EAGAIN EWOULDBLOCK
#endif
#ifndef EWOULDBLOCK
#define EWOULDBLOCK EAGAIN
#endif
#ifndef BUF_SIZE
#define BUF_SIZE 2048
#endif
#ifndef SSMAXCONN
#define SSMAXCONN 1024
#endif
#ifndef UPDATE_INTERVAL
#define UPDATE_INTERVAL 30
#endif
static void signal_cb(EV_P_ ev_signal *w, int revents);
static void accept_cb(EV_P_ ev_io *w, int revents);
static void server_send_cb(EV_P_ ev_io *w, int revents);
static void server_recv_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 void server_timeout_cb(EV_P_ ev_timer *watcher, int revents);
static struct remote * new_remote(int fd);
static struct server * new_server(int fd, struct listen_ctx *listener);
static struct remote *connect_to_remote(struct addrinfo *res,
struct server *server);
static void free_remote(struct remote *remote);
static void close_and_free_remote(EV_P_ struct remote *remote);
static void free_server(struct server *server);
static void close_and_free_server(EV_P_ struct server *server);
static void server_resolve_cb(struct sockaddr *addr, void *data);
int verbose = 0;
static int acl = 0;
static int mode = TCP_ONLY;
static int auth = 0;
static int fast_open = 0;
#ifdef HAVE_SETRLIMIT
static int nofile = 0;
#endif
static int remote_conn = 0;
static int server_conn = 0;
static char *server_port = NULL;
static char *manager_address = NULL;
uint64_t tx = 0;
uint64_t rx = 0;
ev_timer stat_update_watcher;
static struct cork_dllist connections;
static void stat_update_cb(EV_P_ ev_timer *watcher, int revents)
{
struct sockaddr_un svaddr, claddr;
int sfd = -1;
size_t msgLen;
char resp[BUF_SIZE];
if (verbose) {
LOGI("update traffic stat: tx: %"PRIu64" rx: %"PRIu64"", tx, rx);
}
snprintf(resp, BUF_SIZE, "stat: {\"%s\":%"PRIu64"}", server_port, tx + rx);
msgLen = strlen(resp) + 1;
ss_addr_t ip_addr = { .host = NULL, .port = NULL };
parse_addr(manager_address, &ip_addr);
if (ip_addr.host == NULL || ip_addr.port == NULL) {
sfd = socket(AF_UNIX, SOCK_DGRAM, 0);
if (sfd == -1) {
ERROR("stat_socket");
return;
}
memset(&claddr, 0, sizeof(struct sockaddr_un));
claddr.sun_family = AF_UNIX;
snprintf(claddr.sun_path, sizeof(claddr.sun_path), "/tmp/shadowsocks.%s", server_port);
unlink(claddr.sun_path);
if (bind(sfd, (struct sockaddr *) &claddr, sizeof(struct sockaddr_un)) == -1) {
ERROR("stat_bind");
close(sfd);
return;
}
memset(&svaddr, 0, sizeof(struct sockaddr_un));
svaddr.sun_family = AF_UNIX;
strncpy(svaddr.sun_path, manager_address, sizeof(svaddr.sun_path) - 1);
if (sendto(sfd, resp, strlen(resp) + 1, 0, (struct sockaddr *) &svaddr,
sizeof(struct sockaddr_un)) != msgLen) {
ERROR("stat_sendto");
close(sfd);
return;
}
unlink(claddr.sun_path);
} else {
struct sockaddr_storage storage;
memset(&storage, 0, sizeof(struct sockaddr_storage));
if (get_sockaddr(ip_addr.host, ip_addr.port, &storage, 0) == -1) {
ERROR("failed to parse the manager addr");
return;
}
sfd = socket(storage.ss_family, SOCK_DGRAM, 0);
if (sfd == -1) {
ERROR("stat_socket");
return;
}
size_t addr_len = get_sockaddr_len((struct sockaddr *)&storage);
if (sendto(sfd, resp, strlen(resp) + 1, 0, (struct sockaddr *)&storage,
addr_len) != msgLen) {
ERROR("stat_sendto");
close(sfd);
return;
}
}
close(sfd);
}
static void free_connections(struct ev_loop *loop)
{
struct cork_dllist_item *curr;
for (curr = cork_dllist_start(&connections);
!cork_dllist_is_end(&connections, curr);
curr = curr->next) {
struct server *server = cork_container_of(curr, struct server, entries);
struct remote *remote = server->remote;
close_and_free_server(loop, server);
close_and_free_remote(loop, remote);
}
}
static void report_addr(int fd)
{
struct sockaddr_storage addr;
socklen_t len = sizeof addr;
memset(&addr, 0, len);
int err = getpeername(fd, (struct sockaddr *)&addr, &len);
if (err == 0) {
char peer_name[INET6_ADDRSTRLEN] = { 0 };
if (addr.ss_family == AF_INET) {
struct sockaddr_in *s = (struct sockaddr_in *)&addr;
dns_ntop(AF_INET, &s->sin_addr, peer_name, INET_ADDRSTRLEN);
} else if (addr.ss_family == AF_INET6) {
struct sockaddr_in6 *s = (struct sockaddr_in6 *)&addr;
dns_ntop(AF_INET6, &s->sin6_addr, peer_name, INET6_ADDRSTRLEN);
}
LOGE("failed to handshake with %s", peer_name);
}
}
#ifndef __MINGW32__
int setnonblocking(int fd)
{
int flags;
if (-1 == (flags = fcntl(fd, F_GETFL, 0))) {
flags = 0;
}
return fcntl(fd, F_SETFL, flags | O_NONBLOCK);
}
#endif
#ifdef SET_INTERFACE
int setinterface(int socket_fd, const char * interface_name)
{
struct ifreq interface;
memset(&interface, 0, sizeof(interface));
strncpy(interface.ifr_name, interface_name, IFNAMSIZ);
int res = setsockopt(socket_fd, SOL_SOCKET, SO_BINDTODEVICE, &interface,
sizeof(struct ifreq));
return res;
}
#endif
int create_and_bind(const char *host, const char *port)
{
struct addrinfo hints;
struct addrinfo *result, *rp, *ipv4v6bindall;
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 */
hints.ai_flags = AI_PASSIVE | AI_ADDRCONFIG; /* For wildcard IP address */
hints.ai_protocol = IPPROTO_TCP;
for (int i = 1; i < 8; i++) {
s = getaddrinfo(host, port, &hints, &result);
if (s == 0) {
break;
} else {
sleep(pow(2, i));
LOGE("failed to resolve server name, wait %.0f seconds", pow(2, i));
}
}
if (s != 0) {
LOGE("getaddrinfo: %s", gai_strerror(s));
return -1;
}
rp = result;
/*
On Linux, with net.ipv6.bindv6only = 0 (the default), getaddrinfo(NULL) with
AI_PASSIVE returns 0.0.0.0 and :: (in this order). AI_PASSIVE was meant to
return a list of addresses to listen on, but it is impossible to listen on
0.0.0.0 and :: at the same time, if :: implies dualstack mode.
*/
if (!host) {
ipv4v6bindall = result;
/* Loop over all address infos found until a IPV6 address is found. */
while (ipv4v6bindall) {
if (ipv4v6bindall->ai_family == AF_INET6) {
rp = ipv4v6bindall; /* Take first IPV6 address available */
break;
}
ipv4v6bindall = ipv4v6bindall->ai_next; /* Get next address info, if any */
}
}
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;
}
if (rp->ai_family == AF_INET6) {
int ipv6only = host ? 1 : 0;
setsockopt(listen_sock, IPPROTO_IPV6, IPV6_V6ONLY, &ipv6only, sizeof(ipv6only));
}
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
#ifdef TCP_FASTOPEN
if (fast_open) {
opt = 5;
int r = setsockopt(listen_sock, IPPROTO_TCP, TCP_FASTOPEN, &opt,
sizeof(opt));
if (r == -1) {
if (errno == EPROTONOSUPPORT || errno == ENOPROTOOPT) {
LOGE("fast open is not supported on this platform");
} else {
ERROR("setsockopt");
}
}
}
#endif
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);
}
if (rp == NULL) {
LOGE("Could not bind");
return -1;
}
freeaddrinfo(result);
return listen_sock;
}
static struct remote *connect_to_remote(struct addrinfo *res,
struct server *server)
{
int sockfd;
#ifdef SET_INTERFACE
const char *iface = server->listen_ctx->iface;
#endif
// initilize remote socks
sockfd = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
if (sockfd < 0) {
ERROR("socket");
close(sockfd);
return NULL;
}
int opt = 1;
setsockopt(sockfd, SOL_TCP, TCP_NODELAY, &opt, sizeof(opt));
#ifdef SO_NOSIGPIPE
setsockopt(sockfd, SOL_SOCKET, SO_NOSIGPIPE, &opt, sizeof(opt));
#endif
struct remote *remote = new_remote(sockfd);
// setup remote socks
setnonblocking(sockfd);
#ifdef SET_INTERFACE
if (iface) {
setinterface(sockfd, iface);
}
#endif
#ifdef TCP_FASTOPEN
if (fast_open) {
ssize_t s = sendto(sockfd, server->buf + server->buf_idx,
server->buf_len, MSG_FASTOPEN, res->ai_addr,
res->ai_addrlen);
if (s == -1) {
if (errno == EINPROGRESS || errno == EAGAIN
|| errno == EWOULDBLOCK) {
// The remote server doesn't support tfo or it's the first connection to the server.
// It will automatically fall back to conventional TCP.
} else if (errno == EOPNOTSUPP || errno == EPROTONOSUPPORT ||
errno == ENOPROTOOPT) {
// Disable fast open as it's not supported
fast_open = false;
LOGE("fast open is not supported on this platform");
connect(sockfd, res->ai_addr, res->ai_addrlen);
} else {
ERROR("sendto");
}
} else if (s < server->buf_len) {
server->buf_idx += s;
server->buf_len -= s;
} else {
server->buf_idx = 0;
server->buf_len = 0;
}
} else
#endif
connect(sockfd, res->ai_addr, res->ai_addrlen);
return remote;
}
static void server_recv_cb(EV_P_ ev_io *w, int revents)
{
struct server_ctx *server_recv_ctx = (struct server_ctx *)w;
struct server *server = server_recv_ctx->server;
struct remote *remote = NULL;
int len = server->buf_len;
char **buf = &server->buf;
ev_timer_again(EV_A_ & server->recv_ctx->watcher);
if (server->stage != 0) {
remote = server->remote;
buf = &remote->buf;
len = 0;
}
ssize_t r = recv(server->fd, *buf + len, BUF_SIZE - len, 0);
if (r == 0) {
// connection closed
if (verbose) {
LOGI("server_recv close the connection");
}
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;
}
}
tx += r;
// handle incomplete header
if (server->stage == 0) {
r += server->buf_len;
if (r <= enc_get_iv_len()) {
// wait for more
if (verbose) {
#ifdef __MINGW32__
LOGI("imcomplete header: %u", r);
#else
LOGI("imcomplete header: %zu", r);
#endif
}
server->buf_len = r;
return;
} else {
server->buf_len = 0;
}
}
*buf = ss_decrypt(BUF_SIZE, *buf, &r, server->d_ctx);
if (*buf == NULL) {
LOGE("invalid password or cipher");
report_addr(server->fd);
close_and_free_remote(EV_A_ remote);
close_and_free_server(EV_A_ server);
return;
}
// handshake and transmit data
if (server->stage == 5) {
if (server->auth
&& !ss_check_crc(remote->buf, &r, server->crc_buf, &server->crc_idx)) {
LOGE("crc error");
report_addr(server->fd);
close_and_free_server(EV_A_ server);
close_and_free_remote(EV_A_ remote);
return;
}
int s = send(remote->fd, remote->buf, r, 0);
if (s == -1) {
if (errno == EAGAIN || errno == EWOULDBLOCK) {
// no data, wait for send
remote->buf_len = r;
remote->buf_idx = 0;
ev_io_stop(EV_A_ & server_recv_ctx->io);
ev_io_start(EV_A_ & remote->send_ctx->io);
} else {
ERROR("server_recv_send");
close_and_free_remote(EV_A_ remote);
close_and_free_server(EV_A_ server);
}
} else if (s < r) {
remote->buf_len = r - 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 if (server->stage == 0) {
/*
* Shadowsocks TCP Relay Protocol:
*
* +------+----------+----------+-----------------+
* | ATYP | DST.ADDR | DST.PORT | AUTH (Optional) |
* +------+----------+----------+-----------------+
* | 1 | Variable | 2 | 16 |
* +------+----------+----------+-----------------+
*
* If ATYP & ONETIMEAUTH_FLAG(0x10) == 1, AUTH and CRC are enabled.
*/
/*
* Shadowsocks TCP Request Payload CRC (Optional, no CRC for response's payload):
*
* +------+------+------+------+------+
* | DATA | CRC8 | DATA | CRC8 | ...
* +------+------+------+------+------+
* | 128 | 1 | 128 | 1 | ...
* +------+------+------+------+------+
*/
int offset = 0;
int need_query = 0;
char atyp = server->buf[offset++];
char host[256] = { 0 };
uint16_t port = 0;
struct addrinfo info;
struct sockaddr_storage storage;
memset(&info, 0, sizeof(struct addrinfo));
memset(&storage, 0, sizeof(struct sockaddr_storage));
// get remote addr and port
if ((atyp & ADDRTYPE_MASK) == 1) {
// IP V4
struct sockaddr_in *addr = (struct sockaddr_in *)&storage;
size_t in_addr_len = sizeof(struct in_addr);
addr->sin_family = AF_INET;
if (r > in_addr_len) {
addr->sin_addr = *(struct in_addr *)(server->buf + offset);
dns_ntop(AF_INET, (const void *)(server->buf + offset),
host, INET_ADDRSTRLEN);
offset += in_addr_len;
} else {
LOGE("invalid header with addr type %d", atyp);
report_addr(server->fd);
close_and_free_server(EV_A_ server);
return;
}
addr->sin_port = *(uint16_t *)(server->buf + offset);
info.ai_family = AF_INET;
info.ai_socktype = SOCK_STREAM;
info.ai_protocol = IPPROTO_TCP;
info.ai_addrlen = sizeof(struct sockaddr_in);
info.ai_addr = (struct sockaddr *)addr;
} else if ((atyp & ADDRTYPE_MASK) == 3) {
// Domain name
uint8_t name_len = *(uint8_t *)(server->buf + offset);
if (name_len < r) {
memcpy(host, server->buf + offset + 1, name_len);
offset += name_len + 1;
} else {
LOGE("invalid name length: %d", name_len);
report_addr(server->fd);
close_and_free_server(EV_A_ server);
return;
}
struct cork_ip ip;
if (cork_ip_init(&ip, host) != -1) {
info.ai_socktype = SOCK_STREAM;
info.ai_protocol = IPPROTO_TCP;
if (ip.version == 4) {
struct sockaddr_in *addr = (struct sockaddr_in *)&storage;
dns_pton(AF_INET, host, &(addr->sin_addr));
addr->sin_port = *(uint16_t *)(server->buf + offset);
addr->sin_family = AF_INET;
info.ai_family = AF_INET;
info.ai_addrlen = sizeof(struct sockaddr_in);
info.ai_addr = (struct sockaddr *)addr;
} else if (ip.version == 6) {
struct sockaddr_in6 *addr = (struct sockaddr_in6 *)&storage;
dns_pton(AF_INET6, host, &(addr->sin6_addr));
addr->sin6_port = *(uint16_t *)(server->buf + offset);
addr->sin6_family = AF_INET6;
info.ai_family = AF_INET6;
info.ai_addrlen = sizeof(struct sockaddr_in6);
info.ai_addr = (struct sockaddr *)addr;
}
} else {
need_query = 1;
}
} else if ((atyp & ADDRTYPE_MASK) == 4) {
// IP V6
struct sockaddr_in6 *addr = (struct sockaddr_in6 *)&storage;
size_t in6_addr_len = sizeof(struct in6_addr);
addr->sin6_family = AF_INET6;
if (r > in6_addr_len) {
addr->sin6_addr = *(struct in6_addr *)(server->buf + offset);
dns_ntop(AF_INET6, (const void *)(server->buf + offset),
host, INET6_ADDRSTRLEN);
offset += in6_addr_len;
} else {
LOGE("invalid header with addr type %d", atyp);
report_addr(server->fd);
close_and_free_server(EV_A_ server);
return;
}
addr->sin6_port = *(uint16_t *)(server->buf + offset);
info.ai_family = AF_INET6;
info.ai_socktype = SOCK_STREAM;
info.ai_protocol = IPPROTO_TCP;
info.ai_addrlen = sizeof(struct sockaddr_in6);
info.ai_addr = (struct sockaddr *)addr;
}
if (offset == 1) {
LOGE("invalid header with addr type %d", atyp);
report_addr(server->fd);
close_and_free_server(EV_A_ server);
return;
}
if (acl && !need_query && acl_contains_ip(host)) {
if (verbose) {
LOGI("Access denied to %s", host);
}
close_and_free_server(EV_A_ server);
return;
}
port = (*(uint16_t *)(server->buf + offset));
offset += 2;
if (auth || (atyp & ONETIMEAUTH_FLAG)) {
if (ss_onetimeauth_verify(server->buf + offset, server->buf, offset)) {
LOGE("authentication error %d", atyp);
report_addr(server->fd);
close_and_free_server(EV_A_ server);
return;
};
offset += ONETIMEAUTH_BYTES;
server->auth = 1;
}
if (verbose) {
LOGI("connect to: %s:%d", host, ntohs(port));
}
// XXX: should handle buffer carefully
if (r > offset) {
server->buf_len = r - offset;
server->buf_idx = offset;
}
if (server->auth
&& !ss_check_crc(server->buf + server->buf_idx, &server->buf_len, server->crc_buf, &server->crc_idx)) {
LOGE("crc error");
report_addr(server->fd);
close_and_free_server(EV_A_ server);
return;
}
if (!need_query) {
struct remote *remote = connect_to_remote(&info, server);
if (remote == NULL) {
LOGE("connect error");
close_and_free_server(EV_A_ server);
return;
} else {
server->remote = remote;
remote->server = server;
// XXX: should handle buffer carefully
if (server->buf_len > 0) {
memcpy(remote->buf, server->buf + server->buf_idx,
server->buf_len);
remote->buf_len = server->buf_len;
remote->buf_idx = 0;
server->buf_len = 0;
server->buf_idx = 0;
}
server->stage = 4;
// listen to remote connected event
ev_io_stop(EV_A_ & server_recv_ctx->io);
ev_io_start(EV_A_ & remote->send_ctx->io);
}
} else {
server->stage = 4;
server->query = resolv_query(host, server_resolve_cb, NULL, server,
port);
ev_io_stop(EV_A_ & server_recv_ctx->io);
}
return;
}
// should not reach here
FATAL("server context error");
}
static void server_send_cb(EV_P_ ev_io *w, int revents)
{
struct server_ctx *server_send_ctx = (struct server_ctx *)w;
struct server *server = server_send_ctx->server;
struct remote *remote = server->remote;
if (remote == NULL) {
LOGE("invalid server");
close_and_free_server(EV_A_ server);
return;
}
if (server->buf_len == 0) {
// close and free
if (verbose) {
LOGI("server_send close the connection");
}
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 + server->buf_idx,
server->buf_len, 0);
if (s < 0) {
if (errno != EAGAIN && errno != EWOULDBLOCK) {
ERROR("server_send_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);
if (remote != NULL) {
ev_io_start(EV_A_ & remote->recv_ctx->io);
return;
} else {
LOGE("invalid remote");
close_and_free_remote(EV_A_ remote);
close_and_free_server(EV_A_ server);
return;
}
}
}
}
static void server_timeout_cb(EV_P_ ev_timer *watcher, int revents)
{
struct server_ctx *server_ctx = (struct server_ctx *)(((void *)watcher)
- sizeof(ev_io));
struct server *server = server_ctx->server;
struct remote *remote = server->remote;
if (verbose) {
LOGI("TCP connection timeout");
}
close_and_free_remote(EV_A_ remote);
close_and_free_server(EV_A_ server);
}
static void server_resolve_cb(struct sockaddr *addr, void *data)
{
struct server *server = (struct server *)data;
struct ev_loop *loop = server->listen_ctx->loop;
server->query = NULL;
if (addr == NULL) {
LOGE("unable to resolve");
close_and_free_server(EV_A_ server);
} else {
if (verbose) {
LOGI("udns resolved");
}
if (acl) {
char host[INET6_ADDRSTRLEN] = { 0 };
if (addr->sa_family == AF_INET) {
struct sockaddr_in *s = (struct sockaddr_in *)addr;
dns_ntop(AF_INET, &s->sin_addr, host, INET_ADDRSTRLEN);
} else if (addr->sa_family == AF_INET6) {
struct sockaddr_in6 *s = (struct sockaddr_in6 *)addr;
dns_ntop(AF_INET6, &s->sin6_addr, host, INET6_ADDRSTRLEN);
}
if (acl_contains_ip(host)) {
if (verbose) {
LOGI("Access denied to %s", host);
}
close_and_free_server(EV_A_ server);
return;
}
}
struct addrinfo info;
memset(&info, 0, sizeof(struct addrinfo));
info.ai_socktype = SOCK_STREAM;
info.ai_protocol = IPPROTO_TCP;
info.ai_addr = addr;
if (addr->sa_family == AF_INET) {
info.ai_family = AF_INET;
info.ai_addrlen = sizeof(struct sockaddr_in);
} else if (addr->sa_family == AF_INET6) {
info.ai_family = AF_INET6;
info.ai_addrlen = sizeof(struct sockaddr_in6);
}
struct remote *remote = connect_to_remote(&info, server);
if (remote == NULL) {
LOGE("connect error");
close_and_free_server(EV_A_ server);
} else {
server->remote = remote;
remote->server = server;
// XXX: should handle buffer carefully
if (server->buf_len > 0) {
memcpy(remote->buf, server->buf + server->buf_idx,
server->buf_len);
remote->buf_len = server->buf_len;
remote->buf_idx = 0;
server->buf_len = 0;
server->buf_idx = 0;
}
// listen to remote connected event
ev_io_start(EV_A_ & remote->send_ctx->io);
}
}
}
static void remote_recv_cb(EV_P_ ev_io *w, int revents)
{
struct remote_ctx *remote_recv_ctx = (struct remote_ctx *)w;
struct remote *remote = remote_recv_ctx->remote;
struct server *server = remote->server;
if (server == NULL) {
LOGE("invalid server");
close_and_free_remote(EV_A_ remote);
return;
}
ev_timer_again(EV_A_ & server->recv_ctx->watcher);
ssize_t r = recv(remote->fd, server->buf, BUF_SIZE, 0);
if (r == 0) {
// connection closed
if (verbose) {
LOGI("remote_recv close the connection");
}
close_and_free_remote(EV_A_ remote);
close_and_free_server(EV_A_ server);
return;
} else if (r < 0) {
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;
}
}
rx += r;
server->buf = ss_encrypt(BUF_SIZE, server->buf, &r, server->e_ctx);
if (server->buf == NULL) {
LOGE("invalid password or cipher");
close_and_free_remote(EV_A_ remote);
close_and_free_server(EV_A_ server);
return;
}
int s = send(server->fd, server->buf, r, 0);
if (s == -1) {
if (errno == EAGAIN || errno == EWOULDBLOCK) {
// no data, wait for send
server->buf_len = r;
server->buf_idx = 0;
ev_io_stop(EV_A_ & remote_recv_ctx->io);
ev_io_start(EV_A_ & server->send_ctx->io);
} else {
ERROR("remote_recv_send");
close_and_free_remote(EV_A_ remote);
close_and_free_server(EV_A_ server);
}
return;
} else if (s < r) {
server->buf_len = r - s;
server->buf_idx = s;
ev_io_stop(EV_A_ & remote_recv_ctx->io);
ev_io_start(EV_A_ & server->send_ctx->io);
return;
}
}
static void remote_send_cb(EV_P_ ev_io *w, int revents)
{
struct remote_ctx *remote_send_ctx = (struct remote_ctx *)w;
struct remote *remote = remote_send_ctx->remote;
struct server *server = remote->server;
if (server == NULL) {
LOGE("invalid server");
close_and_free_remote(EV_A_ remote);
return;
}
if (!remote_send_ctx->connected) {
struct sockaddr_storage addr;
socklen_t len = sizeof addr;
memset(&addr, 0, len);
int r = getpeername(remote->fd, (struct sockaddr *)&addr, &len);
if (r == 0) {
if (verbose) {
LOGI("remote connected");
}
remote_send_ctx->connected = 1;
if (remote->buf_len == 0) {
server->stage = 5;
ev_io_stop(EV_A_ & remote_send_ctx->io);
ev_io_start(EV_A_ & server->recv_ctx->io);
ev_io_start(EV_A_ & remote->recv_ctx->io);
return;
}
} 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
if (verbose) {
LOGI("remote_send close the connection");
}
close_and_free_remote(EV_A_ remote);
close_and_free_server(EV_A_ server);
return;
} else {
// has data to send
ssize_t s = send(remote->fd, remote->buf + remote->buf_idx,
remote->buf_len, 0);
if (s == -1) {
if (errno != EAGAIN && errno != EWOULDBLOCK) {
ERROR("remote_send_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;
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);
if (server != NULL) {
ev_io_start(EV_A_ & server->recv_ctx->io);
if (server->stage == 4) {
server->stage = 5;
ev_io_start(EV_A_ & remote->recv_ctx->io);
}
} else {
LOGE("invalid server");
close_and_free_remote(EV_A_ remote);
close_and_free_server(EV_A_ server);
}
return;
}
}
}
static struct remote * new_remote(int fd)
{
if (verbose) {
remote_conn++;
}
struct remote *remote;
remote = malloc(sizeof(struct remote));
remote->buf = malloc(BUF_SIZE);
remote->recv_ctx = malloc(sizeof(struct remote_ctx));
remote->send_ctx = malloc(sizeof(struct remote_ctx));
remote->fd = fd;
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);
remote->recv_ctx->remote = remote;
remote->recv_ctx->connected = 0;
remote->send_ctx->remote = remote;
remote->send_ctx->connected = 0;
remote->buf_len = 0;
remote->buf_idx = 0;
remote->server = NULL;
return remote;
}
static void free_remote(struct remote *remote)
{
if (remote->server != NULL) {
remote->server->remote = NULL;
}
if (remote->buf != NULL) {
free(remote->buf);
}
free(remote->recv_ctx);
free(remote->send_ctx);
free(remote);
}
static void close_and_free_remote(EV_P_ struct remote *remote)
{
if (remote != NULL) {
ev_io_stop(EV_A_ & remote->send_ctx->io);
ev_io_stop(EV_A_ & remote->recv_ctx->io);
close(remote->fd);
free_remote(remote);
if (verbose) {
remote_conn--;
LOGI("current remote connection: %d", remote_conn);
}
}
}
static struct server * new_server(int fd, struct listen_ctx *listener)
{
if (verbose) {
server_conn++;
}
struct server *server;
server = malloc(sizeof(struct server));
memset(server, 0, sizeof(struct server));
server->buf = malloc(BUF_SIZE);
server->recv_ctx = malloc(sizeof(struct server_ctx));
server->send_ctx = malloc(sizeof(struct server_ctx));
server->fd = fd;
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->recv_ctx->watcher, server_timeout_cb,
min(MAX_CONNECT_TIMEOUT, listener->timeout), listener->timeout);
server->recv_ctx->server = server;
server->recv_ctx->connected = 0;
server->send_ctx->server = server;
server->send_ctx->connected = 0;
server->stage = 0;
server->query = NULL;
server->listen_ctx = listener;
if (listener->method) {
server->e_ctx = malloc(sizeof(struct enc_ctx));
server->d_ctx = malloc(sizeof(struct enc_ctx));
enc_ctx_init(listener->method, server->e_ctx, 1);
enc_ctx_init(listener->method, server->d_ctx, 0);
} else {
server->e_ctx = NULL;
server->d_ctx = NULL;
}
server->buf_len = 0;
server->buf_idx = 0;
server->remote = NULL;
cork_dllist_add(&connections, &server->entries);
return server;
}
static void free_server(struct server *server)
{
cork_dllist_remove(&server->entries);
if (server->remote != NULL) {
server->remote->server = NULL;
}
if (server->e_ctx != NULL) {
cipher_context_release(&server->e_ctx->evp);
free(server->e_ctx);
}
if (server->d_ctx != NULL) {
cipher_context_release(&server->d_ctx->evp);
free(server->d_ctx);
}
if (server->buf != NULL) {
free(server->buf);
}
free(server->recv_ctx);
free(server->send_ctx);
free(server);
}
static void close_and_free_server(EV_P_ struct server *server)
{
if (server != NULL) {
if (server->query != NULL) {
resolv_cancel(server->query);
server->query = 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->recv_ctx->watcher);
close(server->fd);
free_server(server);
if (verbose) {
server_conn--;
LOGI("current server connection: %d", server_conn);
}
}
}
static void signal_cb(EV_P_ ev_signal *w, int revents)
{
if (revents & EV_SIGNAL) {
switch (w->signum) {
case SIGINT:
case SIGTERM:
ev_unloop(EV_A_ EVUNLOOP_ALL);
}
}
}
static void accept_cb(EV_P_ ev_io *w, int revents)
{
struct listen_ctx *listener = (struct listen_ctx *)w;
int serverfd = accept(listener->fd, NULL, NULL);
if (serverfd == -1) {
ERROR("accept");
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 (verbose) {
LOGI("accept a connection");
}
struct server *server = new_server(serverfd, listener);
ev_io_start(EV_A_ & server->recv_ctx->io);
ev_timer_start(EV_A_ & server->recv_ctx->watcher);
}
int main(int argc, char **argv)
{
int i, c;
int pid_flags = 0;
char *user = NULL;
char *password = NULL;
char *timeout = NULL;
char *method = NULL;
char *pid_path = NULL;
char *conf_path = NULL;
char *iface = NULL;
int server_num = 0;
const char *server_host[MAX_REMOTE_NUM];
char * nameservers[MAX_DNS_NUM + 1];
int nameserver_num = 0;
int option_index = 0;
static struct option long_options[] =
{
{ "fast-open", no_argument, 0, 0 },
{ "acl", required_argument, 0, 0 },
{ "manager-address", required_argument, 0, 0 },
{ 0, 0, 0, 0 }
};
opterr = 0;
USE_TTY();
while ((c = getopt_long(argc, argv, "f:s:p:l:k:t:m:c:i:d:a:uUvA",
long_options, &option_index)) != -1) {
switch (c) {
case 0:
if (option_index == 0) {
fast_open = 1;
} else if (option_index == 1) {
LOGI("initialize acl...");
acl = !init_acl(optarg);
} else if (option_index == 2) {
manager_address = optarg;
}
break;
case 's':
if (server_num < MAX_REMOTE_NUM) {
server_host[server_num++] = optarg;
}
break;
case 'p':
server_port = optarg;
break;
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 'i':
iface = optarg;
break;
case 'd':
if (nameserver_num < MAX_DNS_NUM) {
nameservers[nameserver_num++] = optarg;
}
break;
case 'a':
user = optarg;
break;
case 'u':
mode = TCP_AND_UDP;
break;
case 'U':
mode = UDP_ONLY;
break;
case 'v':
verbose = 1;
break;
case 'A':
auth = 1;
LOGI("onetime authentication enabled");
break;
}
}
if (opterr) {
usage();
exit(EXIT_FAILURE);
}
if (argc == 1) {
if (conf_path == NULL) {
conf_path = DEFAULT_CONF_PATH;
}
}
if (conf_path != NULL) {
jconf_t *conf = read_jconf(conf_path);
if (server_num == 0) {
server_num = conf->remote_num;
for (i = 0; i < server_num; i++) {
server_host[i] = conf->remote_addr[i].host;
}
}
if (server_port == NULL) {
server_port = conf->remote_port;
}
if (password == NULL) {
password = conf->password;
}
if (method == NULL) {
method = conf->method;
}
if (timeout == NULL) {
timeout = conf->timeout;
}
#ifdef TCP_FASTOPEN
if (fast_open == 0) {
fast_open = conf->fast_open;
}
#endif
#ifdef HAVE_SETRLIMIT
if (nofile == 0) {
nofile = conf->nofile;
}
/*
* no need to check the return value here since we will show
* the user an error message if setrlimit(2) fails
*/
if (nofile) {
if (verbose) {
LOGI("setting NOFILE to %d", nofile);
}
set_nofile(nofile);
}
#endif
if (conf->nameserver != NULL) {
nameservers[nameserver_num++] = conf->nameserver;
}
}
if (server_num == 0) {
server_host[server_num++] = NULL;
}
if (server_num == 0 || server_port == NULL || password == NULL) {
usage();
exit(EXIT_FAILURE);
}
if (method == NULL) {
method = "table";
}
if (timeout == NULL) {
timeout = "60";
}
if (pid_flags) {
USE_SYSLOG(argv[0]);
daemonize(pid_path);
}
if (fast_open == 1) {
#ifdef TCP_FASTOPEN
LOGI("using tcp fast open");
#else
LOGE("tcp fast open is not supported by this environment");
#endif
}
#ifdef __MINGW32__
winsock_init();
#else
// ignore SIGPIPE
signal(SIGPIPE, SIG_IGN);
signal(SIGCHLD, SIG_IGN);
signal(SIGABRT, SIG_IGN);
#endif
struct ev_signal sigint_watcher;
struct ev_signal sigterm_watcher;
ev_signal_init(&sigint_watcher, signal_cb, SIGINT);
ev_signal_init(&sigterm_watcher, signal_cb, SIGTERM);
ev_signal_start(EV_DEFAULT, &sigint_watcher);
ev_signal_start(EV_DEFAULT, &sigterm_watcher);
// setup keys
LOGI("initialize ciphers... %s", method);
int m = enc_init(password, method);
// inilitialize ev loop
struct ev_loop *loop = EV_DEFAULT;
// setup udns
if (nameserver_num == 0) {
#ifdef __MINGW32__
nameservers[nameserver_num++] = "8.8.8.8";
resolv_init(loop, nameservers, nameserver_num);
#else
resolv_init(loop, NULL, 0);
#endif
} else {
resolv_init(loop, nameservers, nameserver_num);
}
for (int i = 0; i < nameserver_num; i++) {
LOGI("using nameserver: %s", nameservers[i]);
}
// inilitialize listen context
struct listen_ctx listen_ctx_list[server_num];
// bind to each interface
while (server_num > 0) {
int index = --server_num;
const char * host = server_host[index];
if (mode != UDP_ONLY) {
// Bind to port
int listenfd;
listenfd = create_and_bind(host, server_port);
if (listenfd < 0) {
FATAL("bind() error");
}
if (listen(listenfd, SSMAXCONN) == -1) {
FATAL("listen() error");
}
setnonblocking(listenfd);
struct listen_ctx *listen_ctx = &listen_ctx_list[index];
// Setup proxy context
listen_ctx->timeout = atoi(timeout);
listen_ctx->fd = listenfd;
listen_ctx->method = m;
listen_ctx->iface = iface;
listen_ctx->loop = loop;
ev_io_init(&listen_ctx->io, accept_cb, listenfd, EV_READ);
ev_io_start(loop, &listen_ctx->io);
}
// Setup UDP
if (mode != TCP_ONLY) {
init_udprelay(server_host[index], server_port, m, atoi(timeout),
iface);
}
LOGI("listening at %s:%s", host ? host : "*", server_port);
}
if (manager_address != NULL) {
ev_timer_init(&stat_update_watcher, stat_update_cb, UPDATE_INTERVAL, UPDATE_INTERVAL);
ev_timer_start(EV_DEFAULT, &stat_update_watcher);
}
if (mode != TCP_ONLY) {
LOGI("UDP relay enabled");
}
if (mode == UDP_ONLY) {
LOGI("TCP relay disabled");
}
// setuid
if (user != NULL) {
run_as(user);
}
// Init connections
cork_dllist_init(&connections);
// start ev loop
ev_run(loop, 0);
if (verbose) {
LOGI("closed gracefully");
}
if (manager_address != NULL) {
ev_timer_stop(EV_DEFAULT, &stat_update_watcher);
}
// Clean up
for (int i = 0; i <= server_num; i++) {
struct listen_ctx *listen_ctx = &listen_ctx_list[i];
if (mode != UDP_ONLY) {
ev_io_stop(loop, &listen_ctx->io);
close(listen_ctx->fd);
}
}
if (mode != UDP_ONLY) {
free_connections(loop);
}
if (mode != TCP_ONLY) {
free_udprelay();
}
resolv_shutdown(loop);
#ifdef __MINGW32__
winsock_cleanup();
#endif
ev_signal_stop(EV_DEFAULT, &sigint_watcher);
ev_signal_stop(EV_DEFAULT, &sigterm_watcher);
return 0;
}