static int dns_interpolate_inaddr_arpa(char *buff, int len, const char *key,
const char *ip) {
const char *b, *e;
char *o;
unsigned char dn[DNS_MAXDN];
int il;
struct {
struct in_addr addr;
struct in6_addr addr6;
} a;
/* This function takes a dot delimited string as input and
* reverses the parts split on dot.
*/
(void)key;
if (dns_pton(AF_INET, ip, &a.addr) > 0) {
dns_a4todn(&a.addr, 0, dn, sizeof(dn));
dns_dntop(dn,buff,len);
return strlen(buff);
}
else if (dns_pton(AF_INET6, ip, &a.addr6) > 0) {
dns_a6todn(&a.addr6, 0, dn, sizeof(dn));
dns_dntop(dn,buff,len);
return strlen(buff);
}
o = buff;
il = strlen(ip);
if(len <= il) {
/* not enough room for ip and '\0' */
if(len > 0) buff[0] = '\0';
return 0;
}
e = ip + il;
b = e - 1;
while(b >= ip) {
const char *term;
while(b >= ip && *b != '.') b--; /* Rewind to previous part */
term = b + 1; /* term is one ahead, we went past it */
if(term != e) memcpy(o, term, e - term); /* no sense in copying nothing */
o += e - term; /* advance the term length */
e = b;
b = e - 1;
if(e >= ip) *o++ = '.'; /* we must be at . */
}
*o = '\0';
assert((o - buff) == il);
return o - buff;
}
static int submit(struct ipcheck *ipc) {
struct in_addr addr;
if (dns_pton(AF_INET, ipc->name, &addr) > 0) {
submit_a_queries(ipc, 1, &addr);
ipc->name = NULL;
}
else if (!dns_submit_a4(0, ipc->name, 0, namecb, ipc)) {
error(0, "unable to submit name query for %s: %s\n",
ipc->name, dns_strerror(dns_status(0)));
++failures;
}
return 0;
}
int
bind_to_address(int socket_fd, const char *host)
{
if (host != NULL) {
struct cork_ip ip;
struct sockaddr_storage storage;
memset(&storage, 0, sizeof(storage));
if (cork_ip_init(&ip, host) != -1) {
if (ip.version == 4) {
struct sockaddr_in *addr = (struct sockaddr_in *)&storage;
dns_pton(AF_INET, host, &addr->sin_addr);
addr->sin_family = AF_INET;
return bind(socket_fd, (struct sockaddr *)addr, sizeof(struct sockaddr_in));
} else if (ip.version == 6) {
struct sockaddr_in6 *addr = (struct sockaddr_in6 *)&storage;
dns_pton(AF_INET6, host, &addr->sin6_addr);
addr->sin6_family = AF_INET6;
return bind(socket_fd, (struct sockaddr *)addr, sizeof(struct sockaddr_in6));
}
}
}
return -1;
}
void ape_gethostbyname(char *name, void (*callback)(char *, void *, acetables *), void *data, acetables *g_ape)
{
struct in_addr addr;
struct query *q;
unsigned char dn[DNS_MAXDN];
int abs = 0;
enum dns_type l_qtyp = 0;
if (dns_pton(AF_INET, name, &addr) > 0) {
/* We have an IP */
callback(xstrdup(name), data, g_ape);
return;
} else if (!dns_ptodn(name, strlen(name), dn, sizeof(dn), &abs)) {
/* We have an invalid domain name */
return;
} else {
l_qtyp = DNS_T_A;
}
q = query_new(name, dn, l_qtyp);
q->data = data;
q->callback = callback;
q->g_ape = g_ape;
if (abs) {
abs = DNS_NOSRCH;
}
if (!dns_submit_dn(NULL, dn, qcls, l_qtyp, abs, 0, dnscb, q)) {
query_free(q);
return;
}
dns_timeouts(NULL, -1, 0);
}
static void
server_recv_cb(EV_P_ ev_io *w, int revents)
{
server_ctx_t *server_ctx = (server_ctx_t *)w;
struct sockaddr_storage src_addr;
memset(&src_addr, 0, sizeof(struct sockaddr_storage));
buffer_t *buf = ss_malloc(sizeof(buffer_t));
balloc(buf, buf_size);
socklen_t src_addr_len = sizeof(struct sockaddr_storage);
unsigned int offset = 0;
#ifdef MODULE_REDIR
char control_buffer[64] = { 0 };
struct msghdr msg;
memset(&msg, 0, sizeof(struct msghdr));
struct iovec iov[1];
struct sockaddr_storage dst_addr;
memset(&dst_addr, 0, sizeof(struct sockaddr_storage));
msg.msg_name = &src_addr;
msg.msg_namelen = src_addr_len;
msg.msg_control = control_buffer;
msg.msg_controllen = sizeof(control_buffer);
iov[0].iov_base = buf->data;
iov[0].iov_len = buf_size;
msg.msg_iov = iov;
msg.msg_iovlen = 1;
buf->len = recvmsg(server_ctx->fd, &msg, 0);
if (buf->len == -1) {
ERROR("[udp] server_recvmsg");
goto CLEAN_UP;
} else if (buf->len > packet_size) {
if (verbose) {
LOGI("[udp] UDP server_recv_recvmsg fragmentation");
}
}
if (get_dstaddr(&msg, &dst_addr)) {
LOGE("[udp] unable to get dest addr");
goto CLEAN_UP;
}
src_addr_len = msg.msg_namelen;
#else
ssize_t r;
r = recvfrom(server_ctx->fd, buf->data, buf_size,
0, (struct sockaddr *)&src_addr, &src_addr_len);
if (r == -1) {
// error on recv
// simply drop that packet
ERROR("[udp] server_recv_recvfrom");
goto CLEAN_UP;
} else if (r > packet_size) {
if (verbose) {
LOGI("[udp] server_recv_recvfrom fragmentation");
}
}
buf->len = r;
#endif
if (verbose) {
LOGI("[udp] server receive a packet");
}
#ifdef MODULE_REMOTE
tx += buf->len;
int err = server_ctx->crypto->decrypt_all(buf, server_ctx->crypto->cipher, buf_size);
if (err) {
// drop the packet silently
goto CLEAN_UP;
}
#endif
#ifdef MODULE_LOCAL
#if !defined(MODULE_TUNNEL) && !defined(MODULE_REDIR)
#ifdef __ANDROID__
tx += buf->len;
#endif
uint8_t frag = *(uint8_t *)(buf->data + 2);
offset += 3;
#endif
#endif
/*
*
* SOCKS5 UDP Request
* +----+------+------+----------+----------+----------+
* |RSV | FRAG | ATYP | DST.ADDR | DST.PORT | DATA |
* +----+------+------+----------+----------+----------+
* | 2 | 1 | 1 | Variable | 2 | Variable |
* +----+------+------+----------+----------+----------+
*
* SOCKS5 UDP Response
* +----+------+------+----------+----------+----------+
* |RSV | FRAG | ATYP | DST.ADDR | DST.PORT | DATA |
* +----+------+------+----------+----------+----------+
* | 2 | 1 | 1 | Variable | 2 | Variable |
* +----+------+------+----------+----------+----------+
*
* shadowsocks UDP Request (before encrypted)
* +------+----------+----------+----------+
* | ATYP | DST.ADDR | DST.PORT | DATA |
* +------+----------+----------+----------+
* | 1 | Variable | 2 | Variable |
* +------+----------+----------+----------+
*
* shadowsocks UDP Response (before encrypted)
* +------+----------+----------+----------+
* | ATYP | DST.ADDR | DST.PORT | DATA |
* +------+----------+----------+----------+
* | 1 | Variable | 2 | Variable |
* +------+----------+----------+----------+
*
* shadowsocks UDP Request and Response (after encrypted)
* +-------+--------------+
* | IV | PAYLOAD |
* +-------+--------------+
* | Fixed | Variable |
* +-------+--------------+
*
*/
#ifdef MODULE_REDIR
char addr_header[512] = { 0 };
int addr_header_len = construct_udprelay_header(&dst_addr, addr_header);
if (addr_header_len == 0) {
LOGE("[udp] failed to parse tproxy addr");
goto CLEAN_UP;
}
// reconstruct the buffer
brealloc(buf, buf->len + addr_header_len, buf_size);
memmove(buf->data + addr_header_len, buf->data, buf->len);
memcpy(buf->data, addr_header, addr_header_len);
buf->len += addr_header_len;
#elif MODULE_TUNNEL
char addr_header[512] = { 0 };
char *host = server_ctx->tunnel_addr.host;
char *port = server_ctx->tunnel_addr.port;
uint16_t port_num = (uint16_t)atoi(port);
uint16_t port_net_num = htons(port_num);
int addr_header_len = 0;
struct cork_ip ip;
if (cork_ip_init(&ip, host) != -1) {
if (ip.version == 4) {
// send as IPv4
struct in_addr host_addr;
memset(&host_addr, 0, sizeof(struct in_addr));
int host_len = sizeof(struct in_addr);
if (dns_pton(AF_INET, host, &host_addr) == -1) {
FATAL("IP parser error");
}
addr_header[addr_header_len++] = 1;
memcpy(addr_header + addr_header_len, &host_addr, host_len);
addr_header_len += host_len;
} else if (ip.version == 6) {
// send as IPv6
struct in6_addr host_addr;
memset(&host_addr, 0, sizeof(struct in6_addr));
int host_len = sizeof(struct in6_addr);
if (dns_pton(AF_INET6, host, &host_addr) == -1) {
FATAL("IP parser error");
}
addr_header[addr_header_len++] = 4;
memcpy(addr_header + addr_header_len, &host_addr, host_len);
addr_header_len += host_len;
} else {
FATAL("IP parser error");
}
} else {
// send as domain
int host_len = strlen(host);
addr_header[addr_header_len++] = 3;
addr_header[addr_header_len++] = host_len;
memcpy(addr_header + addr_header_len, host, host_len);
addr_header_len += host_len;
}
memcpy(addr_header + addr_header_len, &port_net_num, 2);
addr_header_len += 2;
// reconstruct the buffer
brealloc(buf, buf->len + addr_header_len, buf_size);
memmove(buf->data + addr_header_len, buf->data, buf->len);
memcpy(buf->data, addr_header, addr_header_len);
buf->len += addr_header_len;
#else
char host[257] = { 0 };
char port[64] = { 0 };
struct sockaddr_storage dst_addr;
memset(&dst_addr, 0, sizeof(struct sockaddr_storage));
int addr_header_len = parse_udprelay_header(buf->data + offset, buf->len - offset,
host, port, &dst_addr);
if (addr_header_len == 0) {
// error in parse header
goto CLEAN_UP;
}
char *addr_header = buf->data + offset;
#endif
#ifdef MODULE_LOCAL
char *key = hash_key(server_ctx->remote_addr->sa_family, &src_addr);
#else
char *key = hash_key(dst_addr.ss_family, &src_addr);
#endif
struct cache *conn_cache = server_ctx->conn_cache;
remote_ctx_t *remote_ctx = NULL;
cache_lookup(conn_cache, key, HASH_KEY_LEN, (void *)&remote_ctx);
if (remote_ctx != NULL) {
if (sockaddr_cmp(&src_addr, &remote_ctx->src_addr, sizeof(src_addr))) {
remote_ctx = NULL;
}
}
// reset the timer
if (remote_ctx != NULL) {
ev_timer_again(EV_A_ & remote_ctx->watcher);
}
if (remote_ctx == NULL) {
if (verbose) {
#ifdef MODULE_REDIR
char src[SS_ADDRSTRLEN];
char dst[SS_ADDRSTRLEN];
strcpy(src, get_addr_str((struct sockaddr *)&src_addr));
strcpy(dst, get_addr_str((struct sockaddr *)&dst_addr));
LOGI("[udp] cache miss: %s <-> %s", dst, src);
#else
LOGI("[udp] cache miss: %s:%s <-> %s", host, port,
get_addr_str((struct sockaddr *)&src_addr));
#endif
}
} else {
if (verbose) {
#ifdef MODULE_REDIR
char src[SS_ADDRSTRLEN];
char dst[SS_ADDRSTRLEN];
strcpy(src, get_addr_str((struct sockaddr *)&src_addr));
strcpy(dst, get_addr_str((struct sockaddr *)&dst_addr));
LOGI("[udp] cache hit: %s <-> %s", dst, src);
#else
LOGI("[udp] cache hit: %s:%s <-> %s", host, port,
get_addr_str((struct sockaddr *)&src_addr));
#endif
}
}
#ifdef MODULE_LOCAL
#if !defined(MODULE_TUNNEL) && !defined(MODULE_REDIR)
if (frag) {
LOGE("[udp] drop a message since frag is not 0, but %d", frag);
goto CLEAN_UP;
}
#endif
const struct sockaddr *remote_addr = server_ctx->remote_addr;
const int remote_addr_len = server_ctx->remote_addr_len;
if (remote_ctx == NULL) {
// Bind to any port
int remotefd = create_remote_socket(remote_addr->sa_family == AF_INET6);
if (remotefd < 0) {
ERROR("[udp] udprelay bind() error");
goto CLEAN_UP;
}
setnonblocking(remotefd);
#ifdef SO_NOSIGPIPE
set_nosigpipe(remotefd);
#endif
#ifdef IP_TOS
// Set QoS flag
int tos = 46;
setsockopt(remotefd, IPPROTO_IP, IP_TOS, &tos, sizeof(tos));
#endif
#ifdef SET_INTERFACE
if (server_ctx->iface) {
if (setinterface(remotefd, server_ctx->iface) == -1)
ERROR("setinterface");
}
#endif
#ifdef __ANDROID__
if (vpn) {
if (protect_socket(remotefd) == -1) {
ERROR("protect_socket");
close(remotefd);
goto CLEAN_UP;
}
}
#endif
// Init remote_ctx
remote_ctx = new_remote(remotefd, server_ctx);
remote_ctx->src_addr = src_addr;
remote_ctx->af = remote_addr->sa_family;
remote_ctx->addr_header_len = addr_header_len;
memcpy(remote_ctx->addr_header, addr_header, addr_header_len);
// Add to conn cache
cache_insert(conn_cache, key, HASH_KEY_LEN, (void *)remote_ctx);
// Start remote io
ev_io_start(EV_A_ & remote_ctx->io);
ev_timer_start(EV_A_ & remote_ctx->watcher);
}
if (offset > 0) {
buf->len -= offset;
memmove(buf->data, buf->data + offset, buf->len);
}
int err = server_ctx->crypto->encrypt_all(buf, server_ctx->crypto->cipher, buf_size);
if (err) {
// drop the packet silently
goto CLEAN_UP;
}
if (buf->len > packet_size) {
if (verbose) {
LOGI("[udp] server_recv_sendto fragmentation");
}
}
int s = sendto(remote_ctx->fd, buf->data, buf->len, 0, remote_addr, remote_addr_len);
if (s == -1) {
ERROR("[udp] server_recv_sendto");
}
#else
int cache_hit = 0;
int need_query = 0;
if (buf->len - addr_header_len > packet_size) {
if (verbose) {
LOGI("[udp] server_recv_sendto fragmentation");
}
}
if (remote_ctx != NULL) {
cache_hit = 1;
// detect destination mismatch
if (remote_ctx->addr_header_len != addr_header_len
|| memcmp(addr_header, remote_ctx->addr_header, addr_header_len) != 0) {
if (dst_addr.ss_family != AF_INET && dst_addr.ss_family != AF_INET6) {
need_query = 1;
}
} else {
memcpy(&dst_addr, &remote_ctx->dst_addr, sizeof(struct sockaddr_storage));
}
} else {
if (dst_addr.ss_family == AF_INET || dst_addr.ss_family == AF_INET6) {
int remotefd = create_remote_socket(dst_addr.ss_family == AF_INET6);
if (remotefd != -1) {
setnonblocking(remotefd);
#ifdef SO_BROADCAST
set_broadcast(remotefd);
#endif
#ifdef SO_NOSIGPIPE
set_nosigpipe(remotefd);
#endif
#ifdef IP_TOS
// Set QoS flag
int tos = 46;
setsockopt(remotefd, IPPROTO_IP, IP_TOS, &tos, sizeof(tos));
#endif
#ifdef SET_INTERFACE
if (server_ctx->iface) {
if (setinterface(remotefd, server_ctx->iface) == -1)
ERROR("setinterface");
}
#endif
remote_ctx = new_remote(remotefd, server_ctx);
remote_ctx->src_addr = src_addr;
remote_ctx->server_ctx = server_ctx;
remote_ctx->addr_header_len = addr_header_len;
memcpy(remote_ctx->addr_header, addr_header, addr_header_len);
memcpy(&remote_ctx->dst_addr, &dst_addr, sizeof(struct sockaddr_storage));
} else {
ERROR("[udp] bind() error");
goto CLEAN_UP;
}
}
}
if (remote_ctx != NULL && !need_query) {
size_t addr_len = get_sockaddr_len((struct sockaddr *)&dst_addr);
int s = sendto(remote_ctx->fd, buf->data + addr_header_len,
buf->len - addr_header_len, 0,
(struct sockaddr *)&dst_addr, addr_len);
if (s == -1) {
ERROR("[udp] sendto_remote");
if (!cache_hit) {
close_and_free_remote(EV_A_ remote_ctx);
}
} else {
if (!cache_hit) {
// Add to conn cache
remote_ctx->af = dst_addr.ss_family;
char *key = hash_key(remote_ctx->af, &remote_ctx->src_addr);
cache_insert(server_ctx->conn_cache, key, HASH_KEY_LEN, (void *)remote_ctx);
ev_io_start(EV_A_ & remote_ctx->io);
ev_timer_start(EV_A_ & remote_ctx->watcher);
}
}
} else {
struct addrinfo hints;
memset(&hints, 0, sizeof(struct addrinfo));
hints.ai_family = AF_UNSPEC;
hints.ai_socktype = SOCK_DGRAM;
hints.ai_protocol = IPPROTO_UDP;
struct query_ctx *query_ctx = new_query_ctx(buf->data + addr_header_len,
buf->len - addr_header_len);
query_ctx->server_ctx = server_ctx;
query_ctx->addr_header_len = addr_header_len;
query_ctx->src_addr = src_addr;
memcpy(query_ctx->addr_header, addr_header, addr_header_len);
if (need_query) {
query_ctx->remote_ctx = remote_ctx;
}
struct ResolvQuery *query = resolv_query(host, query_resolve_cb,
NULL, query_ctx, htons(atoi(port)));
if (query == NULL) {
ERROR("[udp] unable to create DNS query");
close_and_free_query(EV_A_ query_ctx);
goto CLEAN_UP;
}
query_ctx->query = query;
}
#endif
CLEAN_UP:
bfree(buf);
ss_free(buf);
}
static int
parse_udprelay_header(const char *buf, const size_t buf_len,
char *host, char *port, struct sockaddr_storage *storage)
{
const uint8_t atyp = *(uint8_t *)buf;
int offset = 1;
// get remote addr and port
if ((atyp & ADDRTYPE_MASK) == 1) {
// IP V4
size_t in_addr_len = sizeof(struct in_addr);
if (buf_len >= in_addr_len + 3) {
if (storage != NULL) {
struct sockaddr_in *addr = (struct sockaddr_in *)storage;
addr->sin_family = AF_INET;
addr->sin_addr = *(struct in_addr *)(buf + offset);
addr->sin_port = *(uint16_t *)(buf + offset + in_addr_len);
}
if (host != NULL) {
dns_ntop(AF_INET, (const void *)(buf + offset),
host, INET_ADDRSTRLEN);
}
offset += in_addr_len;
}
} else if ((atyp & ADDRTYPE_MASK) == 3) {
// Domain name
uint8_t name_len = *(uint8_t *)(buf + offset);
if (name_len + 4 <= buf_len) {
if (storage != NULL) {
char tmp[257] = { 0 };
struct cork_ip ip;
memcpy(tmp, buf + offset + 1, name_len);
if (cork_ip_init(&ip, tmp) != -1) {
if (ip.version == 4) {
struct sockaddr_in *addr = (struct sockaddr_in *)storage;
dns_pton(AF_INET, tmp, &(addr->sin_addr));
addr->sin_port = *(uint16_t *)(buf + offset + 1 + name_len);
addr->sin_family = AF_INET;
} else if (ip.version == 6) {
struct sockaddr_in6 *addr = (struct sockaddr_in6 *)storage;
dns_pton(AF_INET, tmp, &(addr->sin6_addr));
addr->sin6_port = *(uint16_t *)(buf + offset + 1 + name_len);
addr->sin6_family = AF_INET6;
}
}
}
if (host != NULL) {
memcpy(host, buf + offset + 1, name_len);
}
offset += 1 + name_len;
}
} else if ((atyp & ADDRTYPE_MASK) == 4) {
// IP V6
size_t in6_addr_len = sizeof(struct in6_addr);
if (buf_len >= in6_addr_len + 3) {
if (storage != NULL) {
struct sockaddr_in6 *addr = (struct sockaddr_in6 *)storage;
addr->sin6_family = AF_INET6;
addr->sin6_addr = *(struct in6_addr *)(buf + offset);
addr->sin6_port = *(uint16_t *)(buf + offset + in6_addr_len);
}
if (host != NULL) {
dns_ntop(AF_INET6, (const void *)(buf + offset),
host, INET6_ADDRSTRLEN);
}
offset += in6_addr_len;
}
}
if (offset == 1) {
LOGE("[udp] invalid header with addr type %d", atyp);
return 0;
}
if (port != NULL) {
sprintf(port, "%d", ntohs(*(uint16_t *)(buf + offset)));
}
offset += 2;
return offset;
}
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) {
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 Protocol:
*
* +------+----------+----------+
* | ATYP | DST.ADDR | DST.PORT |
* +------+----------+----------+
* | 1 | Variable | 2 |
* +------+----------+----------+
*/
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 == 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 == 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 == 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 (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 (!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");
}
ssize_t
get_sockaddr(char *host, char *port,
struct sockaddr_storage *storage, int block,
int ipv6first)
{
struct cork_ip ip;
if (cork_ip_init(&ip, host) != -1) {
if (ip.version == 4) {
struct sockaddr_in *addr = (struct sockaddr_in *)storage;
addr->sin_family = AF_INET;
dns_pton(AF_INET, host, &(addr->sin_addr));
if (port != NULL) {
addr->sin_port = htons(atoi(port));
}
} else if (ip.version == 6) {
struct sockaddr_in6 *addr = (struct sockaddr_in6 *)storage;
addr->sin6_family = AF_INET6;
dns_pton(AF_INET6, host, &(addr->sin6_addr));
if (port != NULL) {
addr->sin6_port = htons(atoi(port));
}
}
return 0;
} else {
struct addrinfo hints;
struct addrinfo *result, *rp;
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 */
int err, i;
for (i = 1; i < 8; i++) {
err = getaddrinfo(host, port, &hints, &result);
#if defined(MODULE_LOCAL)
if (!keep_resolving)
break;
#endif
if ((!block || !err)) {
break;
} else {
sleep(pow(2, i));
LOGE("failed to resolve server name, wait %.0f seconds", pow(2, i));
}
}
if (err != 0) {
LOGE("getaddrinfo: %s", gai_strerror(err));
return -1;
}
int prefer_af = ipv6first ? AF_INET6 : AF_INET;
for (rp = result; rp != NULL; rp = rp->ai_next)
if (rp->ai_family == prefer_af) {
if (rp->ai_family == AF_INET)
memcpy(storage, rp->ai_addr, sizeof(struct sockaddr_in));
else if (rp->ai_family == AF_INET6)
memcpy(storage, rp->ai_addr, sizeof(struct sockaddr_in6));
break;
}
if (rp == NULL) {
for (rp = result; rp != NULL; rp = rp->ai_next) {
if (rp->ai_family == AF_INET)
memcpy(storage, rp->ai_addr, sizeof(struct sockaddr_in));
else if (rp->ai_family == AF_INET6)
memcpy(storage, rp->ai_addr, sizeof(struct sockaddr_in6));
break;
}
}
if (rp == NULL) {
LOGE("failed to resolve remote addr");
return -1;
}
freeaddrinfo(result);
return 0;
}
return -1;
}
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 (!remote_send_ctx->connected) {
struct sockaddr_storage addr;
socklen_t len = sizeof addr;
int 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_timer_stop(EV_A_ & remote_send_ctx->watcher);
char *ss_addr_to_send = malloc(BUF_SIZE);
ssize_t addr_len = 0;
ss_addr_t *sa = &server->destaddr;
struct cork_ip ip;
if (cork_ip_init(&ip, sa->host) != -1) {
if (ip.version == 4) {
// send as IPv4
struct in_addr host;
int host_len = sizeof(struct in_addr);
if (dns_pton(AF_INET, sa->host, &host) == -1) {
FATAL("IP parser error");
}
ss_addr_to_send[addr_len++] = 1;
memcpy(ss_addr_to_send + addr_len, &host, host_len);
addr_len += host_len;
} else if (ip.version == 6) {
// send as IPv6
struct in6_addr host;
int host_len = sizeof(struct in6_addr);
if (dns_pton(AF_INET6, sa->host, &host) == -1) {
FATAL("IP parser error");
}
ss_addr_to_send[addr_len++] = 4;
memcpy(ss_addr_to_send + addr_len, &host, host_len);
addr_len += host_len;
} else {
FATAL("IP parser error");
}
} else {
// send as domain
int host_len = strlen(sa->host);
ss_addr_to_send[addr_len++] = 3;
ss_addr_to_send[addr_len++] = host_len;
memcpy(ss_addr_to_send + addr_len, sa->host, host_len);
addr_len += host_len;
}
uint16_t port = htons(atoi(sa->port));
memcpy(ss_addr_to_send + addr_len, &port, 2);
addr_len += 2;
ss_addr_to_send = ss_encrypt(BUF_SIZE, ss_addr_to_send, &addr_len,
server->e_ctx);
if (ss_addr_to_send == NULL) {
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, ss_addr_to_send, addr_len, 0);
free(ss_addr_to_send);
if (s < addr_len) {
LOGE("failed to send addr");
close_and_free_remote(EV_A_ remote);
close_and_free_server(EV_A_ server);
return;
}
ev_io_start(EV_A_ & remote->recv_ctx->io);
ev_io_start(EV_A_ & server->recv_ctx->io);
return;
} else {
ERROR("getpeername");
// not connected
close_and_free_remote(EV_A_ remote);
close_and_free_server(EV_A_ server);
return;
}
} else {
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
ssize_t s = send(remote->fd, remote->buf + remote->buf_idx,
remote->buf_len, 0);
if (s < 0) {
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;
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 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;
}
}
// 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) {
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 Protocol:
*
* +------+----------+----------+
* | ATYP | DST.ADDR | DST.PORT |
* +------+----------+----------+
* | 1 | Variable | 2 |
* +------+----------+----------+
*/
int offset = 1;
int need_query = 0;
char atyp = server->buf[0] & 0x0F;
#ifdef USE_CRYPTO_OPENSSL
char atyp_btc = (server->buf[0] & 0x10) == 0x10 ? 1 : 0;
#endif
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 == 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 == 3) {
// Domain name
uint8_t name_len = *(uint8_t *)(server->buf + offset);
if (name_len < r && name_len < 255 && name_len > 0) {
memcpy(host, server->buf + offset + 1, name_len);
offset += name_len + 1;
}
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 == 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 (verbose) {
LOGI("connect to: %s:%d", host, ntohs(port));
}
#ifdef USE_CRYPTO_OPENSSL
if (bitcoin_list != NULL) {
if (atyp_btc == 0) {
if (verbose) {
LOGE("client should carry with bitcoin information");
}
close_and_free_server(EV_A_ server);
return;
}
/*
* bitcoin information:
* +-----------+-----------+----------+
* | Signature | Timestamp | Address |
* +-----------+-----------+----------+
* | 65 | 4 | String |
* +-----------+-----------+----------+
*/
char *signature = server->buf + offset;
uint8_t *t = (uint8_t *)server->buf + offset + 65;
uint32_t ts = ((uint32_t)*(t + 0) << 24) + ((uint32_t)*(t + 1) << 16)
+ ((uint32_t)*(t + 2) << 8) + ((uint32_t)*(t + 3) << 0);
char *address = server->buf + offset + 65 + 4;
int64_t ts_offset = (int64_t)time(NULL) - (int64_t)ts;
if (labs(ts_offset) > 60 * 30) {
if (verbose) {
LOGE("invalid timestamp: %u, offset too large: %d",
ts, (int32_t)ts_offset);
}
close_and_free_server(EV_A_ server);
return;
}
if (!bitcoin_verify_message(address, (uint8_t *)signature, t, 4)) {
if (verbose) {
LOGE("invalid signature, address: %s", address);
}
close_and_free_server(EV_A_ server);
return;
}
if (bitcoin_check_address(bitcoin_list, address) == 0) {
if (verbose) {
LOGE("address \"%s\" is NOT in list", address);
}
close_and_free_server(EV_A_ server);
return;
}
offset += 65 + 4 + strlen(address) + 1;
if (verbose) {
LOGI("bitcoin address: %s, time offset: %d",
address, (int32_t)ts_offset);
}
}
#endif
// XXX: should handle buffer carefully
if (r > offset) {
server->buf_len = r - offset;
server->buf_idx = offset;
}
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
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;
if (!remote_send_ctx->connected) {
struct sockaddr_storage addr;
socklen_t len = sizeof addr;
int 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_timer_stop(EV_A_ & remote_send_ctx->watcher);
buffer_t ss_addr_to_send;
buffer_t *abuf = &ss_addr_to_send;
balloc(abuf, BUF_SIZE);
ss_addr_t *sa = &server->destaddr;
struct cork_ip ip;
if (cork_ip_init(&ip, sa->host) != -1) {
if (ip.version == 4) {
// send as IPv4
struct in_addr host;
int host_len = sizeof(struct in_addr);
if (dns_pton(AF_INET, sa->host, &host) == -1) {
FATAL("IP parser error");
}
abuf->array[abuf->len++] = 1;
memcpy(abuf->array + abuf->len, &host, host_len);
abuf->len += host_len;
} else if (ip.version == 6) {
// send as IPv6
struct in6_addr host;
int host_len = sizeof(struct in6_addr);
if (dns_pton(AF_INET6, sa->host, &host) == -1) {
FATAL("IP parser error");
}
abuf->array[abuf->len++] = 4;
memcpy(abuf->array + abuf->len, &host, host_len);
abuf->len += host_len;
} else {
FATAL("IP parser error");
}
} else {
// send as domain
int host_len = strlen(sa->host);
abuf->array[abuf->len++] = 3;
abuf->array[abuf->len++] = host_len;
memcpy(abuf->array + abuf->len, sa->host, host_len);
abuf->len += host_len;
}
uint16_t port = htons(atoi(sa->port));
memcpy(abuf->array + abuf->len, &port, 2);
abuf->len += 2;
if (auth) {
abuf->array[0] |= ONETIMEAUTH_FLAG;
ss_onetimeauth(abuf, server->e_ctx->evp.iv, BUF_SIZE);
}
int err = ss_encrypt(abuf, server->e_ctx, BUF_SIZE);
if (err) {
bfree(abuf);
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, abuf->array, abuf->len, 0);
bfree(abuf);
if (s < abuf->len) {
LOGE("failed to send addr");
close_and_free_remote(EV_A_ remote);
close_and_free_server(EV_A_ server);
return;
}
ev_io_start(EV_A_ & remote->recv_ctx->io);
ev_io_start(EV_A_ & server->recv_ctx->io);
return;
} else {
ERROR("getpeername");
// not connected
close_and_free_remote(EV_A_ remote);
close_and_free_server(EV_A_ server);
return;
}
} else {
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
ssize_t s = send(remote->fd, remote->buf->array + 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;
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 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_hash(&remote->buf, &r, server->chunk, server->d_ctx, BUF_SIZE)) {
LOGE("hash 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 Header:
*
* +------+----------+----------+----------------+
* | ATYP | DST.ADDR | DST.PORT | HMAC-SHA1 |
* +------+----------+----------+----------------+
* | 1 | Variable | 2 | 10 |
* +------+----------+----------+----------------+
*
* If ATYP & ONETIMEAUTH_FLAG(0x10) == 1, Authentication (HMAC-SHA1) is enabled.
*
* The key of HMAC-SHA1 is (IV + KEY) and the input is the whole header.
* The output of HMAC-SHA is truncated to 10 bytes (leftmost bits).
*/
/*
* Shadowsocks TCP Request's Chunk Authentication (Optional, no hash check for response's payload):
*
* +------+-----------+-------------+------+
* | LEN | HMAC-SHA1 | DATA | ...
* +------+-----------+-------------+------+
* | 2 | 10 | Variable | ...
* +------+-----------+-------------+------+
*
* The key of HMAC-SHA1 is (IV + CHUNK ID)
* The output of HMAC-SHA is truncated to 10 bytes (leftmost bits).
*/
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, server->d_ctx->evp.iv)) {
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;
memmove(server->buf, server->buf + offset, server->buf_len);
}
if (server->auth && !ss_check_hash(&server->buf, &server->buf_len, server->chunk, server->d_ctx, BUF_SIZE)) {
LOGE("hash 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_recv_cb(EV_P_ ev_io *w, int revents)
{
struct server_ctx *server_ctx = (struct server_ctx *)w;
struct sockaddr_storage src_addr;
memset(&src_addr, 0, sizeof(struct sockaddr_storage));
char *buf = malloc(BUF_SIZE);
socklen_t src_addr_len = sizeof(struct sockaddr_storage);
unsigned int offset = 0;
#ifdef UDPRELAY_REDIR
char control_buffer[64] = { 0 };
struct msghdr msg;
struct iovec iov[1];
struct sockaddr_storage dst_addr;
memset(&dst_addr, 0, sizeof(struct sockaddr_storage));
msg.msg_name = &src_addr;
msg.msg_namelen = src_addr_len;
msg.msg_control = control_buffer;
msg.msg_controllen = sizeof(control_buffer);
iov[0].iov_base = buf;
iov[0].iov_len = BUF_SIZE;
msg.msg_iov = iov;
msg.msg_iovlen = 1;
ssize_t buf_len = recvmsg(server_ctx->fd, &msg, 0);
if (buf_len == -1) {
ERROR("[udp] server_recvmsg");
goto CLEAN_UP;
}
if (get_dstaddr(&msg, &dst_addr)) {
LOGE("[udp] unable to get dest addr");
goto CLEAN_UP;
}
src_addr_len = msg.msg_namelen;
#else
ssize_t buf_len =
recvfrom(server_ctx->fd, buf, BUF_SIZE, 0, (struct sockaddr *)&src_addr,
&src_addr_len);
if (buf_len == -1) {
// error on recv
// simply drop that packet
ERROR("[udp] server_recvfrom");
goto CLEAN_UP;
}
#endif
if (verbose) {
LOGI("[udp] server receive a packet");
}
#ifdef UDPRELAY_REMOTE
tx += buf_len;
buf = ss_decrypt_all(BUF_SIZE, buf, &buf_len, server_ctx->method, server_ctx->auth);
if (buf == NULL) {
ERROR("[udp] server_ss_decrypt_all");
goto CLEAN_UP;
}
#endif
#ifdef UDPRELAY_LOCAL
#if !defined(UDPRELAY_TUNNEL) && !defined(UDPRELAY_REDIR)
uint8_t frag = *(uint8_t *)(buf + 2);
offset += 3;
#endif
#endif
// packet size > default MTU
if (verbose && buf_len > MTU) {
LOGE("[udp] possible ip fragment, size: %d", (int)buf_len);
}
/*
*
* SOCKS5 UDP Request
* +----+------+------+----------+----------+----------+
* |RSV | FRAG | ATYP | DST.ADDR | DST.PORT | DATA |
* +----+------+------+----------+----------+----------+
* | 2 | 1 | 1 | Variable | 2 | Variable |
* +----+------+------+----------+----------+----------+
*
* SOCKS5 UDP Response
* +----+------+------+----------+----------+----------+
* |RSV | FRAG | ATYP | DST.ADDR | DST.PORT | DATA |
* +----+------+------+----------+----------+----------+
* | 2 | 1 | 1 | Variable | 2 | Variable |
* +----+------+------+----------+----------+----------+
*
* shadowsocks UDP Request (before encrypted)
* +------+----------+----------+----------+-------------+
* | ATYP | DST.ADDR | DST.PORT | DATA | HMAC-SHA1 |
* +------+----------+----------+----------+-------------+
* | 1 | Variable | 2 | Variable | 10 |
* +------+----------+----------+----------+-------------+
*
* If ATYP & ONETIMEAUTH_FLAG(0x10) == 1, Authentication (HMAC-SHA1) is enabled.
*
* The key of HMAC-SHA1 is (IV + KEY) and the input is the whole packet.
* The output of HMAC-SHA is truncated to 10 bytes (leftmost bits).
*
* shadowsocks UDP Response (before encrypted)
* +------+----------+----------+----------+
* | ATYP | DST.ADDR | DST.PORT | DATA |
* +------+----------+----------+----------+
* | 1 | Variable | 2 | Variable |
* +------+----------+----------+----------+
*
* shadowsocks UDP Request and Response (after encrypted)
* +-------+--------------+
* | IV | PAYLOAD |
* +-------+--------------+
* | Fixed | Variable |
* +-------+--------------+
*
*/
#ifdef UDPRELAY_REDIR
char addr_header[256] = { 0 };
int addr_header_len = construct_udprealy_header(&dst_addr, addr_header);
if (addr_header_len == 0) {
LOGE("[udp] failed to parse tproxy addr");
goto CLEAN_UP;
}
// reconstruct the buffer
if (BUF_SIZE < buf_len + addr_header_len) {
buf = realloc(buf, buf_len + addr_header_len);
}
memmove(buf + addr_header_len, buf, buf_len);
memcpy(buf, addr_header, addr_header_len);
buf_len += addr_header_len;
char *key = hash_key(dst_addr.ss_family, &src_addr);
#elif UDPRELAY_TUNNEL
char addr_header[256] = { 0 };
char *host = server_ctx->tunnel_addr.host;
char *port = server_ctx->tunnel_addr.port;
uint16_t port_num = (uint16_t)atoi(port);
uint16_t port_net_num = htons(port_num);
int addr_header_len = 0;
struct cork_ip ip;
if (cork_ip_init(&ip, host) != -1) {
if (ip.version == 4) {
// send as IPv4
struct in_addr host_addr;
int host_len = sizeof(struct in_addr);
if (dns_pton(AF_INET, host, &host_addr) == -1) {
FATAL("IP parser error");
}
addr_header[addr_header_len++] = 1;
memcpy(addr_header + addr_header_len, &host_addr, host_len);
addr_header_len += host_len;
} else if (ip.version == 6) {
// send as IPv6
struct in6_addr host_addr;
int host_len = sizeof(struct in6_addr);
if (dns_pton(AF_INET6, host, &host_addr) == -1) {
FATAL("IP parser error");
}
addr_header[addr_header_len++] = 4;
memcpy(addr_header + addr_header_len, &host_addr, host_len);
addr_header_len += host_len;
} else {
FATAL("IP parser error");
}
} else {
// send as domain
int host_len = strlen(host);
addr_header[addr_header_len++] = 3;
addr_header[addr_header_len++] = host_len;
memcpy(addr_header + addr_header_len, host, host_len);
addr_header_len += host_len;
}
memcpy(addr_header + addr_header_len, &port_net_num, 2);
addr_header_len += 2;
// reconstruct the buffer
if (BUF_SIZE < buf_len + addr_header_len) {
buf = realloc(buf, buf_len + addr_header_len);
}
memmove(buf + addr_header_len, buf, buf_len);
memcpy(buf, addr_header, addr_header_len);
buf_len += addr_header_len;
char *key = hash_key(ip.version == 4 ? AF_INET : AF_INET6, &src_addr);
#else
char host[256] = { 0 };
char port[64] = { 0 };
struct sockaddr_storage dst_addr;
memset(&dst_addr, 0, sizeof(struct sockaddr_storage));
int addr_header_len = parse_udprealy_header(buf + offset, buf_len - offset,
&server_ctx->auth, host, port,
&dst_addr);
if (addr_header_len == 0) {
// error in parse header
goto CLEAN_UP;
}
char *addr_header = buf + offset;
char *key = hash_key(dst_addr.ss_family, &src_addr);
#endif
struct cache *conn_cache = server_ctx->conn_cache;
struct remote_ctx *remote_ctx = NULL;
cache_lookup(conn_cache, key, HASH_KEY_LEN, (void *)&remote_ctx);
if (remote_ctx != NULL) {
if (memcmp(&src_addr, &remote_ctx->src_addr, sizeof(src_addr))) {
remote_ctx = NULL;
}
}
// reset the timer
if (remote_ctx != NULL) {
ev_timer_again(EV_A_ & remote_ctx->watcher);
}
if (remote_ctx == NULL) {
if (verbose) {
#ifdef UDPRELAY_REDIR
char src[SS_ADDRSTRLEN];
char dst[SS_ADDRSTRLEN];
strcpy(src, get_addr_str((struct sockaddr *)&src_addr));
strcpy(dst, get_addr_str((struct sockaddr *)&dst_addr));
LOGI("[udp] cache miss: %s <-> %s", dst, src);
#else
LOGI("[udp] cache miss: %s:%s <-> %s", host, port,
get_addr_str((struct sockaddr *)&src_addr));
#endif
}
} else {
if (verbose) {
#ifdef UDPRELAY_REDIR
char src[SS_ADDRSTRLEN];
char dst[SS_ADDRSTRLEN];
strcpy(src, get_addr_str((struct sockaddr *)&src_addr));
strcpy(dst, get_addr_str((struct sockaddr *)&dst_addr));
LOGI("[udp] cache hit: %s <-> %s", dst, src);
#else
LOGI("[udp] cache hit: %s:%s <-> %s", host, port,
get_addr_str((struct sockaddr *)&src_addr));
#endif
}
}
#ifdef UDPRELAY_LOCAL
#if !defined(UDPRELAY_TUNNEL) && !defined(UDPRELAY_REDIR)
if (frag) {
LOGE("[udp] drop a message since frag is not 0, but %d", frag);
goto CLEAN_UP;
}
#endif
const struct sockaddr *remote_addr = server_ctx->remote_addr;
const int remote_addr_len = server_ctx->remote_addr_len;
if (remote_ctx == NULL) {
// Bind to any port
int remotefd = create_remote_socket(remote_addr->sa_family == AF_INET6);
if (remotefd < 0) {
ERROR("[udp] udprelay bind() error");
goto CLEAN_UP;
}
setnonblocking(remotefd);
#ifdef SO_NOSIGPIPE
set_nosigpipe(remotefd);
#endif
#ifdef SET_INTERFACE
if (server_ctx->iface) {
setinterface(remotefd, server_ctx->iface);
}
#endif
#ifdef ANDROID
if (vpn) {
if (protect_socket(remotefd) == -1) {
ERROR("protect_socket");
close(remotefd);
goto CLEAN_UP;
}
}
#endif
// Init remote_ctx
remote_ctx = new_remote(remotefd, server_ctx);
remote_ctx->src_addr = src_addr;
remote_ctx->af = remote_addr->sa_family;
remote_ctx->addr_header_len = addr_header_len;
memcpy(remote_ctx->addr_header, addr_header, addr_header_len);
// Add to conn cache
cache_insert(conn_cache, key, HASH_KEY_LEN, (void *)remote_ctx);
// Start remote io
ev_io_start(EV_A_ & remote_ctx->io);
ev_timer_start(EV_A_ & remote_ctx->watcher);
}
if (offset > 0) {
buf_len -= offset;
memmove(buf, buf + offset, buf_len);
}
if (server_ctx->auth) {
buf[0] |= ONETIMEAUTH_FLAG;
}
buf = ss_encrypt_all(BUF_SIZE, buf, &buf_len, server_ctx->method, server_ctx->auth);
int s = sendto(remote_ctx->fd, buf, buf_len, 0, remote_addr, remote_addr_len);
if (s == -1) {
ERROR("[udp] sendto_remote");
}
#else
int cache_hit = 0;
int need_query = 0;
if (remote_ctx != NULL) {
cache_hit = 1;
// detect destination mismatch
if (remote_ctx->addr_header_len != addr_header_len
|| memcmp(addr_header, remote_ctx->addr_header, addr_header_len) != 0) {
if (dst_addr.ss_family != AF_INET && dst_addr.ss_family != AF_INET6) {
need_query = 1;
}
}
} else {
if (dst_addr.ss_family == AF_INET || dst_addr.ss_family == AF_INET6) {
int remotefd = create_remote_socket(dst_addr.ss_family == AF_INET6);
if (remotefd != -1) {
setnonblocking(remotefd);
#ifdef SO_BROADCAST
set_broadcast(remotefd);
#endif
#ifdef SO_NOSIGPIPE
set_nosigpipe(remotefd);
#endif
#ifdef SET_INTERFACE
if (server_ctx->iface) {
setinterface(remotefd, server_ctx->iface);
}
#endif
remote_ctx = new_remote(remotefd, server_ctx);
remote_ctx->src_addr = src_addr;
remote_ctx->server_ctx = server_ctx;
remote_ctx->addr_header_len = addr_header_len;
memcpy(remote_ctx->addr_header, addr_header, addr_header_len);
} else {
ERROR("[udp] bind() error");
goto CLEAN_UP;
}
}
}
if (remote_ctx != NULL && !need_query) {
size_t addr_len = get_sockaddr_len((struct sockaddr *)&dst_addr);
int s = sendto(remote_ctx->fd, buf + addr_header_len,
buf_len - addr_header_len, 0,
(struct sockaddr *)&dst_addr, addr_len);
if (s == -1) {
ERROR("[udp] sendto_remote");
if (!cache_hit) {
close_and_free_remote(EV_A_ remote_ctx);
}
} else {
if (!cache_hit) {
// Add to conn cache
remote_ctx->af = dst_addr.ss_family;
char *key = hash_key(remote_ctx->af, &remote_ctx->src_addr);
cache_insert(server_ctx->conn_cache, key, HASH_KEY_LEN, (void *)remote_ctx);
ev_io_start(EV_A_ & remote_ctx->io);
ev_timer_start(EV_A_ & remote_ctx->watcher);
}
}
} else {
struct addrinfo hints;
memset(&hints, 0, sizeof(hints));
hints.ai_family = AF_UNSPEC;
hints.ai_socktype = SOCK_DGRAM;
hints.ai_protocol = IPPROTO_UDP;
struct query_ctx *query_ctx = new_query_ctx(buf + addr_header_len,
buf_len -
addr_header_len);
query_ctx->server_ctx = server_ctx;
query_ctx->addr_header_len = addr_header_len;
query_ctx->src_addr = src_addr;
memcpy(query_ctx->addr_header, addr_header, addr_header_len);
if (need_query) {
query_ctx->remote_ctx = remote_ctx;
}
struct ResolvQuery *query = resolv_query(host, query_resolve_cb,
NULL, query_ctx, htons(atoi(port)));
if (query == NULL) {
ERROR("[udp] unable to create DNS query");
close_and_free_query(EV_A_ query_ctx);
goto CLEAN_UP;
}
query_ctx->query = query;
}
#endif
CLEAN_UP:
free(buf);
}
