commit d3525f2b14c6d2b5c267dd5aaed747d36af95bfe Author: David Goulet dgoulet@ev0ke.net Date: Fri Jun 21 14:15:52 2013 -0400

Implement the connect(2) torsocks call. Not final but working

Signed-off-by: David Goulet dgoulet@ev0ke.net --- src/lib/torsocks.c | 114 +++++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 113 insertions(+), 1 deletion(-)

diff --git a/src/lib/torsocks.c b/src/lib/torsocks.c index 94abc97..0382d38 100644 --- a/src/lib/torsocks.c +++ b/src/lib/torsocks.c @@ -214,15 +214,127 @@ static void __attribute__((destructor)) tsocks_exit(void) log_destroy(); }

-#include <arpa/inet.h> +/* + * Initiate a SOCK5 connection to the Tor network using the given connection. + * The socks5 API will use the torsocks configuration object to find the tor + * daemon. + * + * Return 0 on success or else a negative value being the errno value that + * needs to be sent back. + */ +static int connect_to_tor_network(struct connection *conn) +{ + int ret; + + assert(conn); + + DBG("Connecting to the Tor network on fd %d", conn->fd); + + ret = socks5_connect(conn); + if (ret < 0) { + goto error; + } + + ret = socks5_send_method(conn); + if (ret < 0) { + goto error; + } + + ret = socks5_recv_method(conn); + if (ret < 0) { + goto error; + } + + ret = socks5_send_connect_request(conn); + if (ret < 0) { + goto error; + } + + ret = socks5_recv_connect_reply(conn); + if (ret < 0) { + goto error; + } + +error: + return ret; +}

/* * Torsocks call for connect(2). */ LIBC_CONNECT_RET_TYPE tsocks_connect(LIBC_CONNECT_SIG) { + int ret, sock_type; + socklen_t optlen; + struct connection *new_conn; + DBG("Connect catched on fd %d", __sockfd); + + ret = getsockopt(__sockfd, SOL_SOCKET, SO_TYPE, &sock_type, &optlen); + if (ret < 0) { + /* Use the getsockopt() errno value. */ + goto error; + } + + /* We can't handle a non inet socket. */ + if (__addr->sa_family != AF_INET && + __addr->sa_family != AF_INET6) { + DBG("[conect] Connection is not IPv4/v6. Ignoring."); + goto libc_connect; + } + + /* + * Refuse non stream socket. There is a chance that this might be a DNS + * request that we can't pass through Tor using raw UDP packet. + */ + if (sock_type != SOCK_STREAM) { + ERR("[connect] UDP or ICMP stream can't be handled. Rejecting."); + errno = EBADF; + goto error; + } + + /* + * Lock registry to get the connection reference if one. In this code path, + * if a connection object is found, it will not be used since a double + * connect() on the same file descriptor is an error so the registry is + * quickly unlocked and no reference is needed. + */ + connection_registry_lock(); + new_conn = connection_find(__sockfd); + connection_registry_unlock(); + if (new_conn) { + /* Double connect() for the same fd. */ + errno = EISCONN; + goto error; + } + + new_conn = connection_create(__sockfd, __addr); + if (!new_conn) { + errno = ENOMEM; + goto error; + } + + /* Connect the socket to the Tor network. */ + ret = connect_to_tor_network(new_conn); + if (ret < 0) { + errno = -ret; + goto error; + } + + connection_registry_lock(); + /* This can't fail since a lookup was done previously. */ + connection_insert(new_conn); + connection_registry_unlock(); + + /* Flag errno for success */ + ret = errno = 0; + return ret; + +libc_connect: return tsocks_libc_connect(LIBC_CONNECT_ARGS); +error: + /* At this point, errno MUST be set to a valid connect() error value. */ + return -1; }

/*