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[tor-commits] [tor/master] Make tor_ersatz_socketpair work on IPv6-only systems
commit 53ec840bdfa3dfa421b3cecd7a90a3cd5e39d15c
Author: teor (Tim Wilson-Brown) <teor2345@xxxxxxxxx>
Date: Thu Nov 19 19:08:22 2015 +1100
Make tor_ersatz_socketpair work on IPv6-only systems
(But it won't work on some systems without IPv4/IPv6 localhost
(some BSD jails) by design, to avoid creating sockets on routable
IP addresses. However, those systems likely have the AF_UNIX socketpair,
which tor prefers.)
Fixes bug #17638; bugfix on a very early tor version,
earlier than 22dba27d8dd5 (23 Nov 2004) / svn:r2943.
Patch by "teor".
---
changes/bug17638-ipv6-ersatz-socketpair | 5 ++
src/common/compat.c | 88 ++++++++++++++++++++++---------
src/test/test_util.c | 16 ++----
3 files changed, 74 insertions(+), 35 deletions(-)
diff --git a/changes/bug17638-ipv6-ersatz-socketpair b/changes/bug17638-ipv6-ersatz-socketpair
new file mode 100644
index 0000000..6193065
--- /dev/null
+++ b/changes/bug17638-ipv6-ersatz-socketpair
@@ -0,0 +1,5 @@
+ o Minor bugfix (IPv6 compatibility, unit tests):
+ - Make tor_ersatz_socketpair work on IPv6-only systems.
+ Fixes bug #17638; bugfix on a very early tor version,
+ earlier than 22dba27d8dd5 (23 Nov 2004) / svn:r2943.
+ Patch by "teor".
diff --git a/src/common/compat.c b/src/common/compat.c
index 7d72b4b..24698c3 100644
--- a/src/common/compat.c
+++ b/src/common/compat.c
@@ -1486,6 +1486,12 @@ tor_socketpair(int family, int type, int protocol, tor_socket_t fd[2])
}
#ifdef NEED_ERSATZ_SOCKETPAIR
+
+#define SIZEOF_SOCKADDR(domain) \
+ (domain == AF_INET ? sizeof(struct sockaddr_in) : \
+ (domain == AF_INET6 ? sizeof(struct sockaddr_in6) : \
+ ((size_t)0) /* unsupported, don't match any valid size */))
+
/**
* Helper used to implement socketpair on systems that lack it, by
* making a direct connection to localhost.
@@ -1501,12 +1507,19 @@ tor_ersatz_socketpair(int family, int type, int protocol, tor_socket_t fd[2])
tor_socket_t listener = TOR_INVALID_SOCKET;
tor_socket_t connector = TOR_INVALID_SOCKET;
tor_socket_t acceptor = TOR_INVALID_SOCKET;
- struct sockaddr_in listen_addr;
- struct sockaddr_in connect_addr;
+ tor_addr_t listen_tor_addr;
+ struct sockaddr listen_addr;
+ in_port_t listen_port = 0;
+ tor_addr_t connect_tor_addr;
+ in_port_t connect_port = 0;
+ struct sockaddr connect_addr;
socklen_t size;
int saved_errno = -1;
+ int ersatz_domain = AF_INET;
+ memset(&connect_tor_addr, 0, sizeof(connect_tor_addr));
memset(&connect_addr, 0, sizeof(connect_addr));
+ memset(&listen_tor_addr, 0, sizeof(listen_tor_addr));
memset(&listen_addr, 0, sizeof(listen_addr));
if (protocol
@@ -1524,47 +1537,71 @@ tor_ersatz_socketpair(int family, int type, int protocol, tor_socket_t fd[2])
return -EINVAL;
}
- listener = tor_open_socket(AF_INET, type, 0);
- if (!SOCKET_OK(listener))
- return -tor_socket_errno(-1);
- memset(&listen_addr, 0, sizeof(listen_addr));
- listen_addr.sin_family = AF_INET;
- listen_addr.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
- listen_addr.sin_port = 0; /* kernel chooses port. */
- if (bind(listener, (struct sockaddr *) &listen_addr, sizeof (listen_addr))
- == -1)
+ listener = tor_open_socket(ersatz_domain, type, 0);
+ if (!SOCKET_OK(listener)) {
+ int first_errno = tor_socket_errno(-1);
+ if (first_errno == SOCK_ERRNO(EPROTONOSUPPORT)
+ && ersatz_domain == AF_INET) {
+ /* Assume we're on an IPv6-only system */
+ ersatz_domain = AF_INET6;
+ listener = tor_open_socket(ersatz_domain, type, 0);
+ if (!SOCKET_OK(listener)) {
+ /* Keep the previous behaviour, which was to return the IPv4 error.
+ * (This may be less informative on IPv6-only systems.)
+ * XX/teor - is there a better way to decide which errno to return?
+ * (I doubt we care much either way, once there is an error.)
+ */
+ return -first_errno;
+ }
+ }
+ }
+ /* If there is no 127.0.0.1 or ::1, this will and must fail. Otherwise, we
+ * risk exposing a socketpair on a routable IP address. (Some BSD jails
+ * use a routable address for localhost. Fortunately, they have the real
+ * AF_UNIX socketpair.) */
+ if (ersatz_domain == AF_INET) {
+ tor_addr_from_ipv4h(&listen_tor_addr, INADDR_LOOPBACK);
+ } else {
+ tor_addr_parse(&listen_tor_addr, "[::1]");
+ }
+ tor_assert(tor_addr_is_loopback(&listen_tor_addr));
+ tor_addr_to_sockaddr(&listen_tor_addr,
+ 0 /* kernel chooses port. */,
+ &listen_addr,
+ sizeof (listen_addr));
+ if (bind(listener, &listen_addr, sizeof (listen_addr)) == -1)
goto tidy_up_and_fail;
if (listen(listener, 1) == -1)
goto tidy_up_and_fail;
- connector = tor_open_socket(AF_INET, type, 0);
+ connector = tor_open_socket(ersatz_domain, type, 0);
if (!SOCKET_OK(connector))
goto tidy_up_and_fail;
/* We want to find out the port number to connect to. */
size = sizeof(connect_addr);
- if (getsockname(listener, (struct sockaddr *) &connect_addr, &size) == -1)
+ if (getsockname(listener, &connect_addr, &size) == -1)
goto tidy_up_and_fail;
- if (size != sizeof (connect_addr))
+ if (size != SIZEOF_SOCKADDR (connect_addr.sa_family))
goto abort_tidy_up_and_fail;
- if (connect(connector, (struct sockaddr *) &connect_addr,
- sizeof(connect_addr)) == -1)
+ if (connect(connector, &connect_addr, sizeof(connect_addr)) == -1)
goto tidy_up_and_fail;
size = sizeof(listen_addr);
- acceptor = tor_accept_socket(listener,
- (struct sockaddr *) &listen_addr, &size);
+ acceptor = tor_accept_socket(listener, &listen_addr, &size);
if (!SOCKET_OK(acceptor))
goto tidy_up_and_fail;
- if (size != sizeof(listen_addr))
+ if (size != SIZEOF_SOCKADDR(listen_addr.sa_family))
goto abort_tidy_up_and_fail;
/* Now check we are talking to ourself by matching port and host on the
two sockets. */
- if (getsockname(connector, (struct sockaddr *) &connect_addr, &size) == -1)
+ if (getsockname(connector, &connect_addr, &size) == -1)
goto tidy_up_and_fail;
- if (size != sizeof (connect_addr)
- || listen_addr.sin_family != connect_addr.sin_family
- || listen_addr.sin_addr.s_addr != connect_addr.sin_addr.s_addr
- || listen_addr.sin_port != connect_addr.sin_port) {
+ /* Set *_tor_addr and *_port to the address and port that was used */
+ tor_addr_from_sockaddr(&listen_tor_addr, &listen_addr, &listen_port);
+ tor_addr_from_sockaddr(&connect_tor_addr, &connect_addr, &connect_port);
+ if (size != SIZEOF_SOCKADDR (connect_addr.sa_family)
+ || tor_addr_compare(&listen_tor_addr, &connect_tor_addr, CMP_SEMANTIC)
+ || listen_port != connect_port) {
goto abort_tidy_up_and_fail;
}
tor_close_socket(listener);
@@ -1590,6 +1627,9 @@ tor_ersatz_socketpair(int family, int type, int protocol, tor_socket_t fd[2])
tor_close_socket(acceptor);
return -saved_errno;
}
+
+#undef SIZEOF_SOCKADDR
+
#endif
/* Return the maximum number of allowed sockets. */
diff --git a/src/test/test_util.c b/src/test/test_util.c
index 187cb23..eecc50a 100644
--- a/src/test/test_util.c
+++ b/src/test/test_util.c
@@ -4342,9 +4342,6 @@ fd_is_nonblocking(tor_socket_t fd)
}
#endif
-#define ERRNO_IS_EPROTO(e) (e == SOCK_ERRNO(EPROTONOSUPPORT))
-#define SOCK_ERR_IS_EPROTO(s) ERRNO_IS_EPROTO(tor_socket_errno(s))
-
/* Test for tor_open_socket*, using IPv4 or IPv6 depending on arg. */
static void
test_util_socket(void *arg)
@@ -4361,7 +4358,7 @@ test_util_socket(void *arg)
(void)arg;
fd1 = tor_open_socket_with_extensions(domain, SOCK_STREAM, 0, 0, 0);
- if (SOCK_ERR_IS_EPROTO(fd1)) {
+ if (tor_socket_errno(fd1) == SOCK_ERRNO(EPROTONOSUPPORT)) {
/* Assume we're on an IPv4-only or IPv6-only system, and give up now. */
goto done;
}
@@ -4424,11 +4421,10 @@ test_util_socketpair(void *arg)
int socketpair_result = 0;
socketpair_result = tor_socketpair_fn(family, SOCK_STREAM, 0, fds);
- if (ersatz && ERRNO_IS_EPROTO(-socketpair_result)) {
- /* Assume we're on an IPv6-only system, and give up now.
- * (tor_ersatz_socketpair uses IPv4.) */
- goto done;
- }
+ /* If there is no 127.0.0.1 or ::1, tor_ersatz_socketpair will and must fail.
+ * Otherwise, we risk exposing a socketpair on a routable IP address. (Some
+ * BSD jails use a routable address for localhost. Fortunately, they have
+ * the real AF_UNIX socketpair.) */
tt_int_op(0, OP_EQ, socketpair_result);
tt_assert(SOCKET_OK(fds[0]));
tt_assert(SOCKET_OK(fds[1]));
@@ -4449,8 +4445,6 @@ test_util_socketpair(void *arg)
tor_close_socket(fds[1]);
}
-#undef SOCKET_EPROTO
-
static void
test_util_max_mem(void *arg)
{
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