Skip to content

Commit

Permalink
Allow bypass UDP packets in tun2socks
Browse files Browse the repository at this point in the history
  • Loading branch information
@madeye
madeye committed Dec 27, 2018
1 parent 88bc6f6 commit f4f802b
Show file tree
Hide file tree
Showing 3 changed files with 97 additions and 23 deletions.
114 changes: 94 additions & 20 deletions tun2socks/SocksUdpGwClient.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -35,6 +35,9 @@

#ifdef __ANDROID__

#include <ancillary.h>
#include <sys/prctl.h>
#include <sys/un.h>
#include <misc/socks_proto.h>
#define CONNECTION_UDP_BUFFER_SIZE 1

Expand All @@ -54,11 +57,57 @@ static void dgram_handler (SocksUdpGwClient_connection *o, int event);
static void dgram_handler_received (SocksUdpGwClient_connection *o, uint8_t *data, int data_len);
static int conaddr_comparator (void *unused, SocksUdpGwClient_conaddr *v1, SocksUdpGwClient_conaddr *v2);
static SocksUdpGwClient_connection * find_connection (SocksUdpGwClient *o, SocksUdpGwClient_conaddr conaddr);
static SocksUdpGwClient_connection * reuse_connection (SocksUdpGwClient *o, SocksUdpGwClient_conaddr conaddr);
static SocksUdpGwClient_connection * reuse_connection (SocksUdpGwClient *o, SocksUdpGwClient_conaddr conaddr, int is_bypass, int is_dns);
static void connection_send (SocksUdpGwClient_connection *o, const uint8_t *data, int data_len);
static void connection_first_job_handler (SocksUdpGwClient_connection *con);
static SocksUdpGwClient_connection *connection_init (SocksUdpGwClient *client, SocksUdpGwClient_conaddr conaddr, const uint8_t *data, int data_len, int is_dns);
static SocksUdpGwClient_connection *connection_init (SocksUdpGwClient *client, SocksUdpGwClient_conaddr conaddr, const uint8_t *data, int data_len, int is_bypass, int is_dns);
static void connection_free (SocksUdpGwClient_connection *o);
static int protect_socket(int fd);

static int protect_socket(int fd)
{
int sock;
struct sockaddr_un addr;

if ((sock = socket(AF_UNIX, SOCK_STREAM, 0)) == -1) {
BLog(BLOG_ERROR, "[SocksUdpGwClient] socket() failed\n");
return -1;
}

// Set timeout to 3s
struct timeval tv;
tv.tv_sec = 3;
tv.tv_usec = 0;
setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO, (char *)&tv, sizeof(struct timeval));
setsockopt(sock, SOL_SOCKET, SO_SNDTIMEO, (char *)&tv, sizeof(struct timeval));

memset(&addr, 0, sizeof(addr));
addr.sun_family = AF_UNIX;
strncpy(addr.sun_path, "protect_path", sizeof(addr.sun_path) - 1);

if (connect(sock, (struct sockaddr *)&addr, sizeof(addr)) == -1) {
BLog(BLOG_ERROR, "[SocksUdpGwClient] connect() failed for protect_path\n");
close(sock);
return -1;
}

if (ancil_send_fd(sock, fd)) {
BLog(BLOG_ERROR, "[SocksUdpGwClient] ancil_send_fd");
close(sock);
return -1;
}

char ret = 0;

if (recv(sock, &ret, 1, 0) == -1) {
BLog(BLOG_ERROR, "[SocksUdpGwClient] ancil_recv");
close(sock);
return -1;
}

close(sock);
return ret;
}

static void dgram_handler (SocksUdpGwClient_connection *o, int event)
{
Expand All @@ -82,7 +131,7 @@ static void dgram_handler_received (SocksUdpGwClient_connection *o, uint8_t *dat
// accept packet
PacketPassInterface_Done(&o->udp_recv_if);

if (!o->is_dns) {
if (!o->is_bypass) {

// check header
if (data_len < sizeof(struct socks_udp_header)) {
Expand Down Expand Up @@ -146,10 +195,6 @@ static void dgram_handler_received (SocksUdpGwClient_connection *o, uint8_t *dat

static int conaddr_comparator (void *unused, SocksUdpGwClient_conaddr *v1, SocksUdpGwClient_conaddr *v2)
{
int r = BAddr_CompareOrder(&v1->remote_addr, &v2->remote_addr);
if (r) {
return r;
}
return BAddr_CompareOrder(&v1->local_addr, &v2->local_addr);
}

Expand All @@ -163,7 +208,7 @@ static SocksUdpGwClient_connection * find_connection (SocksUdpGwClient *o, Socks
return UPPER_OBJECT(tree_node, SocksUdpGwClient_connection, connections_tree_node);
}

static SocksUdpGwClient_connection * reuse_connection (SocksUdpGwClient *o, SocksUdpGwClient_conaddr conaddr)
static SocksUdpGwClient_connection * reuse_connection (SocksUdpGwClient *o, SocksUdpGwClient_conaddr conaddr, int is_bypass, int is_dns)
{
ASSERT(!find_connection(o, conaddr))
ASSERT(o->num_connections > 0)
Expand All @@ -177,6 +222,10 @@ static SocksUdpGwClient_connection * reuse_connection (SocksUdpGwClient *o, Sock
// set new conaddr
con->conaddr = conaddr;

// reinit states
con->is_bypass = is_bypass;
con->is_dns = is_dns;

// insert to connections tree by conaddr
ASSERT_EXECUTE(BAVL_Insert(&o->connections_tree, &con->connections_tree_node, NULL))

Expand All @@ -193,7 +242,7 @@ static void connection_send (SocksUdpGwClient_connection *o, const uint8_t *data
}
int out_pos = 0;

if (!o->is_dns) {
if (!o->is_bypass) {

// write header
BAddr remote_addr = o->conaddr.remote_addr;
Expand Down Expand Up @@ -240,7 +289,7 @@ static void connection_first_job_handler (SocksUdpGwClient_connection *con)
connection_send(con, con->first_data, con->first_data_len);
}

static SocksUdpGwClient_connection *connection_init (SocksUdpGwClient *client, SocksUdpGwClient_conaddr conaddr, const uint8_t *data, int data_len, int is_dns)
static SocksUdpGwClient_connection *connection_init (SocksUdpGwClient *client, SocksUdpGwClient_conaddr conaddr, const uint8_t *data, int data_len, int is_bypass, int is_dns)
{
// allocate structure
SocksUdpGwClient_connection *o = (SocksUdpGwClient_connection *) malloc(sizeof(*o));
Expand All @@ -254,6 +303,7 @@ static SocksUdpGwClient_connection *connection_init (SocksUdpGwClient *client, S
o->conaddr = conaddr;
o->first_data = data;
o->first_data_len = data_len;
o->is_bypass = is_bypass;
o->is_dns = is_dns;

// init first job
Expand All @@ -265,6 +315,11 @@ static SocksUdpGwClient_connection *connection_init (SocksUdpGwClient *client, S
goto fail0;
}

#ifdef __ANDROID__
// Protect UDP dgram
protect_socket(BDatagram_GetFd(&o->udp_dgram));
#endif

// set SO_REUSEADDR
if (!BDatagram_SetReuseAddr(&o->udp_dgram, 1)) {
BLog(BLOG_ERROR, "set SO_REUSEADDR failed");
Expand All @@ -275,9 +330,14 @@ static SocksUdpGwClient_connection *connection_init (SocksUdpGwClient *client, S
BIPAddr ipaddr;
memset(&ipaddr, 0, sizeof(ipaddr));

if (is_dns) {
ipaddr.type = client->dnsgw.type;
BDatagram_SetSendAddrs(&o->udp_dgram, client->dnsgw, ipaddr);
if (o->is_bypass) {
if (o->is_dns) {
ipaddr.type = client->dnsgw.type;
BDatagram_SetSendAddrs(&o->udp_dgram, client->dnsgw, ipaddr);
} else {
ipaddr.type = o->conaddr.remote_addr.type;
BDatagram_SetSendAddrs(&o->udp_dgram, o->conaddr.remote_addr, ipaddr);
}
} else {
ipaddr.type = client->socks_server_addr.type;
BDatagram_SetSendAddrs(&o->udp_dgram, client->socks_server_addr, ipaddr);
Expand Down Expand Up @@ -579,7 +639,7 @@ void SocksUdpGwClient_Free (SocksUdpGwClient *o)
#endif
}

void SocksUdpGwClient_SubmitPacket (SocksUdpGwClient *o, BAddr local_addr, BAddr remote_addr, int is_dns, const uint8_t *data, int data_len)
void SocksUdpGwClient_SubmitPacket (SocksUdpGwClient *o, BAddr local_addr, BAddr remote_addr, int is_bypass, int is_dns, const uint8_t *data, int data_len)
{
DebugObject_Access(&o->d_obj);
// see asserts in UdpGwClient_SubmitPacket
Expand All @@ -600,16 +660,30 @@ void SocksUdpGwClient_SubmitPacket (SocksUdpGwClient *o, BAddr local_addr, BAddr

// if no connection and can't create a new one, reuse the least recently used une
if (!con && o->num_connections == o->max_connections) {
con = reuse_connection(o, conaddr);

// reinit dns status
con->is_dns = is_dns;
con = reuse_connection(o, conaddr, is_bypass, is_dns);
}

if (!con) {
// create new connection
con = connection_init(o, conaddr, data, data_len, is_dns);
con = connection_init(o, conaddr, data, data_len, is_bypass, is_dns);
} else {
// set UDP dgram send address
BIPAddr ipaddr;
memset(&ipaddr, 0, sizeof(ipaddr));

if (con->is_bypass) {
if (con->is_dns) {
ipaddr.type = o->dnsgw.type;
BDatagram_SetSendAddrs(&con->udp_dgram, o->dnsgw, ipaddr);
} else {
ipaddr.type = con->conaddr.remote_addr.type;
BDatagram_SetSendAddrs(&con->udp_dgram, con->conaddr.remote_addr, ipaddr);
}
} else {
ipaddr.type = o->socks_server_addr.type;
BDatagram_SetSendAddrs(&con->udp_dgram, o->socks_server_addr, ipaddr);
}

// move connection to front of the list
LinkedList1_Remove(&o->connections_list, &con->connections_list_node);
LinkedList1_Append(&o->connections_list, &con->connections_list_node);
Expand All @@ -619,7 +693,7 @@ void SocksUdpGwClient_SubmitPacket (SocksUdpGwClient *o, BAddr local_addr, BAddr
}
#else
// submit to udpgw client
UdpGwClient_SubmitPacket(&o->udpgw_client, local_addr, remote_addr, is_dns, data, data_len);
UdpGwClient_SubmitPacket(&o->udpgw_client, local_addr, remote_addr, is_bypass, data, data_len);
#endif
}

3 changes: 2 additions & 1 deletion tun2socks/SocksUdpGwClient.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -87,6 +87,7 @@ typedef struct {
BPending first_job;
const uint8_t *first_data;
int first_data_len;
int is_bypass;
int is_dns;
BDatagram udp_dgram;
BufferWriter udp_send_writer;
Expand All @@ -103,6 +104,6 @@ int SocksUdpGwClient_Init (SocksUdpGwClient *o, int udp_mtu, int max_connections
BAddr remote_udpgw_addr, btime_t reconnect_time, BReactor *reactor, void *user,
SocksUdpGwClient_handler_received handler_received) WARN_UNUSED;
void SocksUdpGwClient_Free (SocksUdpGwClient *o);
void SocksUdpGwClient_SubmitPacket (SocksUdpGwClient *o, BAddr local_addr, BAddr remote_addr, int is_dns, const uint8_t *data, int data_len);
void SocksUdpGwClient_SubmitPacket (SocksUdpGwClient *o, BAddr local_addr, BAddr remote_addr, int is_bypass, int is_dns, const uint8_t *data, int data_len);

#endif
3 changes: 1 addition & 2 deletions tun2socks/tun2socks.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -388,7 +388,6 @@ static void daemonize(const char* path) {
}
#endif


#ifdef __ANDROID__
int wait_for_fd()
{
Expand Down Expand Up @@ -1486,7 +1485,7 @@ int process_device_udp_packet (uint8_t *data, int data_len)
}

// submit packet to udpgw
SocksUdpGwClient_SubmitPacket(&udpgw_client, local_addr, remote_addr, is_dns, data, data_len);
SocksUdpGwClient_SubmitPacket(&udpgw_client, local_addr, remote_addr, options.dnsgw != NULL, is_dns, data, data_len);

return 1;

Expand Down

0 comments on commit f4f802b

Please sign in to comment.