diff options
Diffstat (limited to 'src/or/connection.c')
| -rw-r--r-- | src/or/connection.c | 161 |
1 files changed, 127 insertions, 34 deletions
diff --git a/src/or/connection.c b/src/or/connection.c index 6e754a0f7a..87fa79970e 100644 --- a/src/or/connection.c +++ b/src/or/connection.c @@ -44,6 +44,7 @@ #include "router.h" #include "transports.h" #include "routerparse.h" +#include "transports.h" #ifdef USE_BUFFEREVENTS #include <event2/event.h> @@ -1580,6 +1581,32 @@ connection_proxy_state_to_string(int state) return states[state]; } +/** Returns the global proxy type used by tor. Use this function for + * logging or high-level purposes, don't use it to fill the + * <b>proxy_type</b> field of or_connection_t; use the actual proxy + * protocol instead.*/ +static int +get_proxy_type(void) +{ + const or_options_t *options = get_options(); + + if (options->HTTPSProxy) + return PROXY_CONNECT; + else if (options->Socks4Proxy) + return PROXY_SOCKS4; + else if (options->Socks5Proxy) + return PROXY_SOCKS5; + else if (options->ClientTransportPlugin) + return PROXY_PLUGGABLE; + else + return PROXY_NONE; +} + +/* One byte for the version, one for the command, two for the + port, and four for the addr... and, one more for the + username NUL: */ +#define SOCKS4_STANDARD_BUFFER_SIZE (1 + 1 + 2 + 4 + 1) + /** Write a proxy request of <b>type</b> (socks4, socks5, https) to conn * for conn->addr:conn->port, authenticating with the auth details given * in the configuration (if available). SOCKS 5 and HTTP CONNECT proxies @@ -1634,17 +1661,45 @@ connection_proxy_connect(connection_t *conn, int type) } case PROXY_SOCKS4: { - unsigned char buf[9]; + unsigned char *buf; uint16_t portn; uint32_t ip4addr; + size_t buf_size = 0; + char *socks_args_string = NULL; - /* Send a SOCKS4 connect request with empty user id */ + /* Send a SOCKS4 connect request */ if (tor_addr_family(&conn->addr) != AF_INET) { log_warn(LD_NET, "SOCKS4 client is incompatible with IPv6"); return -1; } + { /* If we are here because we are trying to connect to a + pluggable transport proxy, check if we have any SOCKS + arguments to transmit. If we do, compress all arguments to + a single string in 'socks_args_string': */ + + if (get_proxy_type() == PROXY_PLUGGABLE) { + socks_args_string = + pt_get_socks_args_for_proxy_addrport(&conn->addr, conn->port); + if (socks_args_string) + log_debug(LD_NET, "Sending out '%s' as our SOCKS argument string.", + socks_args_string); + } + } + + { /* Figure out the buffer size we need for the SOCKS message: */ + + buf_size = SOCKS4_STANDARD_BUFFER_SIZE; + + /* If we have a SOCKS argument string, consider its size when + calculating the buffer size: */ + if (socks_args_string) + buf_size += strlen(socks_args_string); + } + + buf = tor_malloc_zero(buf_size); + ip4addr = tor_addr_to_ipv4n(&conn->addr); portn = htons(conn->port); @@ -1652,9 +1707,23 @@ connection_proxy_connect(connection_t *conn, int type) buf[1] = SOCKS_COMMAND_CONNECT; /* command */ memcpy(buf + 2, &portn, 2); /* port */ memcpy(buf + 4, &ip4addr, 4); /* addr */ - buf[8] = 0; /* userid (empty) */ - connection_write_to_buf((char *)buf, sizeof(buf), conn); + /* Next packet field is the userid. If we have pluggable + transport SOCKS arguments, we have to embed them + there. Otherwise, we use an empty userid. */ + if (socks_args_string) { /* place the SOCKS args string: */ + tor_assert(strlen(socks_args_string) > 0); + tor_assert(buf_size >= + SOCKS4_STANDARD_BUFFER_SIZE + strlen(socks_args_string)); + strlcpy((char *)buf + 8, socks_args_string, buf_size - 8); + tor_free(socks_args_string); + } else { + buf[8] = 0; /* no userid */ + } + + connection_write_to_buf((char *)buf, buf_size, conn); + tor_free(buf); + conn->proxy_state = PROXY_SOCKS4_WANT_CONNECT_OK; break; } @@ -1666,8 +1735,13 @@ connection_proxy_connect(connection_t *conn, int type) buf[0] = 5; /* version */ + /* We have to use SOCKS5 authentication, if we have a + Socks5ProxyUsername or if we want to pass arguments to our + pluggable transport proxy: */ + if ((options->Socks5ProxyUsername) || + (get_proxy_type() == PROXY_PLUGGABLE && + (get_socks_args_by_bridge_addrport(&conn->addr, conn->port)))) { /* number of auth methods */ - if (options->Socks5ProxyUsername) { buf[1] = 2; buf[2] = 0x00; /* no authentication */ buf[3] = 0x02; /* rfc1929 Username/Passwd auth */ @@ -1861,15 +1935,49 @@ connection_read_proxy_handshake(connection_t *conn) unsigned char buf[1024]; size_t reqsize, usize, psize; const char *user, *pass; + char *socks_args_string = NULL; + + if (get_proxy_type() == PROXY_PLUGGABLE) { + socks_args_string = + pt_get_socks_args_for_proxy_addrport(&conn->addr, conn->port); + if (!socks_args_string) { + log_warn(LD_NET, "Could not create SOCKS args string."); + ret = -1; + break; + } + + log_debug(LD_NET, "SOCKS5 arguments: %s", socks_args_string); + tor_assert(strlen(socks_args_string) > 0); + tor_assert(strlen(socks_args_string) <= MAX_SOCKS5_AUTH_SIZE_TOTAL); + + if (strlen(socks_args_string) > MAX_SOCKS5_AUTH_FIELD_SIZE) { + user = socks_args_string; + usize = MAX_SOCKS5_AUTH_FIELD_SIZE; + pass = socks_args_string + MAX_SOCKS5_AUTH_FIELD_SIZE; + psize = strlen(socks_args_string) - MAX_SOCKS5_AUTH_FIELD_SIZE; + } else { + user = socks_args_string; + usize = strlen(socks_args_string); + pass = "\0"; + psize = 1; + } + } else if (get_options()->Socks5ProxyUsername) { + user = get_options()->Socks5ProxyUsername; + pass = get_options()->Socks5ProxyPassword; + tor_assert(user && pass); + usize = strlen(user); + psize = strlen(pass); + } else { + log_err(LD_BUG, "We entered %s for no reason!", __func__); + tor_fragile_assert(); + ret = -1; + break; + } - user = get_options()->Socks5ProxyUsername; - pass = get_options()->Socks5ProxyPassword; - tor_assert(user && pass); - - /* XXX len of user and pass must be <= 255 !!! */ - usize = strlen(user); - psize = strlen(pass); - tor_assert(usize <= 255 && psize <= 255); + /* Username and password lengths should have been checked + above and during torrc parsing. */ + tor_assert(usize <= MAX_SOCKS5_AUTH_FIELD_SIZE && + psize <= MAX_SOCKS5_AUTH_FIELD_SIZE); reqsize = 3 + usize + psize; buf[0] = 1; /* negotiation version */ @@ -1878,6 +1986,9 @@ connection_read_proxy_handshake(connection_t *conn) buf[2 + usize] = psize; memcpy(buf + 3 + usize, pass, psize); + if (socks_args_string) + tor_free(socks_args_string); + connection_write_to_buf((char *)buf, reqsize, conn); conn->proxy_state = PROXY_SOCKS5_WANT_AUTH_RFC1929_OK; @@ -3288,8 +3399,8 @@ connection_outbuf_too_full(connection_t *conn) /** Try to flush more bytes onto <b>conn</b>-\>s. * - * This function gets called either from conn_write() in main.c - * when poll() has declared that conn wants to write, or below + * This function gets called either from conn_write_callback() in main.c + * when libevent tells us that conn wants to write, or below * from connection_write_to_buf() when an entire TLS record is ready. * * Update <b>conn</b>-\>timestamp_lastwritten to now, and call flush_buf @@ -4366,7 +4477,7 @@ get_proxy_addrport(tor_addr_t *addr, uint16_t *port, int *proxy_type, options->Bridges) { const transport_t *transport = NULL; int r; - r = find_transport_by_bridge_addrport(&conn->addr, conn->port, &transport); + r = get_transport_by_bridge_addrport(&conn->addr, conn->port, &transport); if (r<0) return -1; if (transport) { /* transport found */ @@ -4381,24 +4492,6 @@ get_proxy_addrport(tor_addr_t *addr, uint16_t *port, int *proxy_type, return 0; } -/** Returns the global proxy type used by tor. */ -static int -get_proxy_type(void) -{ - const or_options_t *options = get_options(); - - if (options->HTTPSProxy) - return PROXY_CONNECT; - else if (options->Socks4Proxy) - return PROXY_SOCKS4; - else if (options->Socks5Proxy) - return PROXY_SOCKS5; - else if (options->ClientTransportPlugin) - return PROXY_PLUGGABLE; - else - return PROXY_NONE; -} - /** Log a failed connection to a proxy server. * <b>conn</b> is the connection we use the proxy server for. */ void |