[tor-commits] [torsocks/master] socks5: Always use ATYP 0x03 for CONNECT command
dgoulet at torproject.org
dgoulet at torproject.org
Fri Apr 20 14:55:17 UTC 2018
commit a0070f02d77315b640dbc00105a246ef64d89011
Author: David Goulet <dgoulet at torproject.org>
Date: Fri Apr 20 10:34:34 2018 -0400
socks5: Always use ATYP 0x03 for CONNECT command
Because of the SafeSocks parameter of Tor, if set, we can't pass a raw IP
address to Tor since it will believe we did a DNS resolution from the
application.
Now, thanks to #22461, Tor safely accepts an IPv4/IPv6 address withing a FQDN
connect request which avoids the SafeSocks warnings.
The #22461 wasn't backported which means that torsocks working with SafeSocks
is only possible in tor >= 0.3.2 stable series.
Fixes #23667
Signed-off-by: David Goulet <dgoulet at torproject.org>
---
src/common/socks5.c | 80 ++++++++++++++++++++++--------------------------
tests/unit/test_socks5.c | 54 ++++++--------------------------
2 files changed, 46 insertions(+), 88 deletions(-)
diff --git a/src/common/socks5.c b/src/common/socks5.c
index 1be2ab8..bf6019a 100644
--- a/src/common/socks5.c
+++ b/src/common/socks5.c
@@ -385,75 +385,60 @@ int socks5_send_connect_request(struct connection *conn)
unsigned char buffer[1500];
ssize_t buf_len, ret_send;
struct socks5_request msg;
+ struct socks5_request_domain req_name;
+ const char *retp;
assert(conn);
assert(conn->fd >= 0);
+ memset(&req_name, 0, sizeof(req_name));
memset(buffer, 0, sizeof(buffer));
buf_len = sizeof(msg);
+ /* Set up the header part. It is always the same, even the address type as
+ * Tor handles IPv4/IPv6 as a Domain Name so SafeSocks doesn't complain. For
+ * this reason, we always send ATYP 0x03 (domain name) to Tor. */
msg.ver = SOCKS5_VERSION;
msg.cmd = SOCKS5_CMD_CONNECT;
/* Always zeroed. */
msg.rsv = 0;
+ msg.atyp = SOCKS5_ATYP_DOMAIN;
+ memcpy(buffer, &msg, buf_len);
+ /* Depending on the domain of the connection, we'll set the hostname
+ * accordingly that is transforming the address into a text format. */
switch (conn->dest_addr.domain) {
case CONNECTION_DOMAIN_INET:
{
- struct socks5_request_ipv4 req_ipv4;
-
- msg.atyp = SOCKS5_ATYP_IPV4;
- /* Copy the first part of the request. */
- memcpy(buffer, &msg, buf_len);
-
- /* Prepare the ipv4 payload to be copied in the send buffer. */
- memcpy(req_ipv4.addr, &conn->dest_addr.u.sin.sin_addr,
- sizeof(req_ipv4.addr));
- req_ipv4.port = conn->dest_addr.u.sin.sin_port;
-
- /* Copy ipv4 request portion in the buffer. */
- memcpy(buffer + buf_len, &req_ipv4, sizeof(req_ipv4));
- buf_len += sizeof(req_ipv4);
+ retp = inet_ntop(AF_INET, &conn->dest_addr.u.sin.sin_addr,
+ (char *) req_name.name, sizeof(req_name.name));
+ if (retp == NULL) {
+ ERR("Socks5 connection malformed IPv4");
+ ret = -EINVAL;
+ goto error;
+ }
+ req_name.port = conn->dest_addr.u.sin.sin_port;
break;
}
case CONNECTION_DOMAIN_INET6:
{
- struct socks5_request_ipv6 req_ipv6;
-
- msg.atyp = SOCKS5_ATYP_IPV6;
- /* Copy the first part of the request. */
- memcpy(buffer, &msg, buf_len);
-
- /* Prepare the ipv6 payload to be copied in the send buffer. */
- memcpy(req_ipv6.addr, &conn->dest_addr.u.sin6.sin6_addr,
- sizeof(req_ipv6.addr));
- req_ipv6.port = conn->dest_addr.u.sin6.sin6_port;
-
- /* Copy ipv6 request portion in the buffer. */
- memcpy(buffer + buf_len, &req_ipv6, sizeof(req_ipv6));
- buf_len += sizeof(req_ipv6);
+ retp = inet_ntop(AF_INET6, &conn->dest_addr.u.sin6.sin6_addr,
+ (char *) req_name.name, sizeof(req_name.name));
+ if (retp == NULL) {
+ ERR("Socks5 connection malformed IPv4");
+ ret = -EINVAL;
+ goto error;
+ }
+ req_name.port = conn->dest_addr.u.sin6.sin6_port;
break;
}
case CONNECTION_DOMAIN_NAME:
{
- struct socks5_request_domain req_name;
-
- msg.atyp = SOCKS5_ATYP_DOMAIN;
- /* Copy the first part of the request. */
- memcpy(buffer, &msg, buf_len);
-
/* Setup domain name request buffer. */
req_name.len = strlen(conn->dest_addr.hostname.addr);
- memcpy(req_name.name, conn->dest_addr.hostname.addr, req_name.len);
+ memcpy(req_name.name, conn->dest_addr.hostname.addr,
+ strlen(conn->dest_addr.hostname.addr));
req_name.port = conn->dest_addr.hostname.port;
-
- /* Copy ipv6 request portion in the buffer. */
- memcpy(buffer + buf_len, &req_name.len, sizeof(req_name.len));
- buf_len += sizeof(req_name.len);
- memcpy(buffer + buf_len, req_name.name, req_name.len);
- buf_len += req_name.len;
- memcpy(buffer + buf_len, &req_name.port, sizeof(req_name.port));
- buf_len += sizeof(req_name.port);
break;
}
default:
@@ -462,6 +447,15 @@ int socks5_send_connect_request(struct connection *conn)
goto error;
}
+ /* Common for everyone, copy the filled up request buffer. */
+ req_name.len = strlen((char *) req_name.name);
+ memcpy(buffer + buf_len, &req_name.len, sizeof(req_name.len));
+ buf_len += sizeof(req_name.len);
+ memcpy(buffer + buf_len, req_name.name, req_name.len);
+ buf_len += req_name.len;
+ memcpy(buffer + buf_len, &req_name.port, sizeof(req_name.port));
+ buf_len += sizeof(req_name.port);
+
DBG("Socks5 sending connect request to fd %d", conn->fd);
ret_send = send_data(conn->fd, &buffer, buf_len);
diff --git a/tests/unit/test_socks5.c b/tests/unit/test_socks5.c
index ac8ed3c..284abc4 100644
--- a/tests/unit/test_socks5.c
+++ b/tests/unit/test_socks5.c
@@ -30,8 +30,6 @@
static struct socks5_method_req method_req;
static struct socks5_request req;
-static struct socks5_request_ipv4 req_ipv4;
-static struct socks5_request_ipv6 req_ipv6;
static struct socks5_request_domain req_name;
static struct socks5_request_resolve req_resolve;
static struct socks5_request_resolve_ptr req_resolve_ptr;
@@ -138,37 +136,12 @@ static ssize_t socks5_recv_method_no_accept_stub(int fd, void *buf, size_t len)
* send_connect_request test doubles
*/
-static ssize_t socks5_send_connect_request_ipv4_spy(int fd, const void *buf,
- size_t len)
-{
- ssize_t buf_len = 0;
-
- set_socks5_request(buf);
- buf_len += sizeof(struct socks5_request);
-
- req_ipv4 = (*(struct socks5_request_ipv4 *) (buf + buf_len));
-
- return 1;
-}
-
-static ssize_t socks5_send_connect_request_ipv6_spy(int fd, const void *buf,
- size_t len)
-{
- ssize_t buf_len = 0;
-
- set_socks5_request(buf);
- buf_len += sizeof(struct socks5_request);
-
- req_ipv6 = (*(struct socks5_request_ipv6 *) (buf + buf_len));
-
- return 1;
-}
-
static ssize_t socks5_send_connect_request_domain_spy(int fd, const void *buf,
size_t len)
{
ssize_t buf_len = 0;
+ memset(&req_name, 0, sizeof(req_name));
set_socks5_request(buf);
buf_len += sizeof(struct socks5_request);
@@ -597,24 +570,19 @@ static void test_socks5_send_connect_request(void)
{
int ret;
struct connection *conn_stub;
- char ip[INET6_ADDRSTRLEN];
conn_stub = get_connection_stub();
- socks5_init(socks5_send_connect_request_ipv4_spy, NULL);
+ socks5_init(socks5_send_connect_request_domain_spy, NULL);
ret = socks5_send_connect_request(conn_stub);
- inet_ntop(AF_INET,
- (struct sockaddr_in *)&req_ipv4.addr,
- ip, INET6_ADDRSTRLEN);
-
ok(ret == 0 &&
req.ver == SOCKS5_VERSION &&
req.cmd == SOCKS5_CMD_CONNECT &&
req.rsv == 0 &&
- req.atyp == SOCKS5_ATYP_IPV4 &&
- strncmp(ip, "127.0.0.1", INET6_ADDRSTRLEN) == 0 &&
- req_ipv4.port == htons(9050),
+ req.atyp == SOCKS5_ATYP_DOMAIN &&
+ strncmp((char *) req_name.name, "127.0.0.1", INET6_ADDRSTRLEN) == 0 &&
+ req_name.port == htons(9050),
"socks5 send connect request IPv4");
connection_destroy(conn_stub);
@@ -623,21 +591,17 @@ static void test_socks5_send_connect_request(void)
/* IPv6 */
conn_stub = get_connection_ipv6_stub();
- socks5_init(socks5_send_connect_request_ipv6_spy, NULL);
+ socks5_init(socks5_send_connect_request_domain_spy, NULL);
ret = socks5_send_connect_request(conn_stub);
- inet_ntop(AF_INET6,
- (struct sockaddr_in *)&req_ipv6.addr,
- ip, INET6_ADDRSTRLEN);
-
ok(ret == 0 &&
req.ver == SOCKS5_VERSION &&
req.cmd == SOCKS5_CMD_CONNECT &&
req.rsv == 0 &&
- req.atyp == SOCKS5_ATYP_IPV6 &&
- strncmp(ip, "::1", INET6_ADDRSTRLEN) == 0 &&
- req_ipv6.port == htons(9050),
+ req.atyp == SOCKS5_ATYP_DOMAIN &&
+ strncmp((char *) req_name.name, "::1", INET6_ADDRSTRLEN) == 0 &&
+ req_name.port == htons(9050),
"socks5 send connect request IPv6");
/* Domain name */
More information about the tor-commits
mailing list