Extract tor_ersatz_socketpair into a new c file

I'm doing this because I want to make it a lower-level function
again, so that we can use it without linking in the rest of the
universe.

1 files changed, 1 insertions, 154 deletions

diff --git a/src/lib/net/socket.c b/src/lib/net/socket.c
index 5847bb8734..5487b8d9df 100644
--- a/src/lib/net/socket.c
+++ b/src/lib/net/socket.c
@@ -11,6 +11,7 @@
 
 #define SOCKET_PRIVATE
 #include "lib/net/socket.h"
+#include "lib/net/socketpair.h"
 #include "lib/net/address.h"
 #include "lib/cc/compat_compiler.h"
 #include "lib/err/torerr.h"
@@ -476,160 +477,6 @@ tor_socketpair(int family, int type, int protocol, tor_socket_t fd[2])
 #endif /* defined(HAVE_SOCKETPAIR) && !defined(_WIN32) */
 }
 
-#ifdef NEED_ERSATZ_SOCKETPAIR
-
-static inline socklen_t
-SIZEOF_SOCKADDR(int domain)
-{
-  switch (domain) {
-    case AF_INET:
-      return sizeof(struct sockaddr_in);
-    case AF_INET6:
-      return sizeof(struct sockaddr_in6);
-    default:
-      return 0;
-  }
-}
-
-/**
- * Helper used to implement socketpair on systems that lack it, by
- * making a direct connection to localhost.
- */
-STATIC int
-tor_ersatz_socketpair(int family, int type, int protocol, tor_socket_t fd[2])
-{
-    /* This socketpair does not work when localhost is down. So
-     * it's really not the same thing at all. But it's close enough
-     * for now, and really, when localhost is down sometimes, we
-     * have other problems too.
-     */
-    tor_socket_t listener = TOR_INVALID_SOCKET;
-    tor_socket_t connector = TOR_INVALID_SOCKET;
-    tor_socket_t acceptor = TOR_INVALID_SOCKET;
-    tor_addr_t listen_tor_addr;
-    struct sockaddr_storage connect_addr_ss, listen_addr_ss;
-    struct sockaddr *listen_addr = (struct sockaddr *) &listen_addr_ss;
-    uint16_t listen_port = 0;
-    tor_addr_t connect_tor_addr;
-    uint16_t connect_port = 0;
-    struct sockaddr *connect_addr = (struct sockaddr *) &connect_addr_ss;
-    socklen_t size;
-    int saved_errno = -1;
-    int ersatz_domain = AF_INET;
-
-    memset(&connect_tor_addr, 0, sizeof(connect_tor_addr));
-    memset(&connect_addr_ss, 0, sizeof(connect_addr_ss));
-    memset(&listen_tor_addr, 0, sizeof(listen_tor_addr));
-    memset(&listen_addr_ss, 0, sizeof(listen_addr_ss));
-
-    if (protocol
-#ifdef AF_UNIX
-        || family != AF_UNIX
-#endif
-        ) {
-#ifdef _WIN32
-      return -WSAEAFNOSUPPORT;
-#else
-      return -EAFNOSUPPORT;
-#endif
-    }
-    if (!fd) {
-      return -EINVAL;
-    }
-
-    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));
-    size = tor_addr_to_sockaddr(&listen_tor_addr,
-                         0 /* kernel chooses port.  */,
-                         listen_addr,
-                         sizeof(listen_addr_ss));
-    if (bind(listener, listen_addr, size) == -1)
-      goto tidy_up_and_fail;
-    if (listen(listener, 1) == -1)
-      goto tidy_up_and_fail;
-
-    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_ss);
-    if (getsockname(listener, connect_addr, &size) == -1)
-      goto tidy_up_and_fail;
-    if (size != SIZEOF_SOCKADDR (connect_addr->sa_family))
-      goto abort_tidy_up_and_fail;
-    if (connect(connector, connect_addr, size) == -1)
-      goto tidy_up_and_fail;
-
-    size = sizeof(listen_addr_ss);
-    acceptor = tor_accept_socket(listener, listen_addr, &size);
-    if (!SOCKET_OK(acceptor))
-      goto tidy_up_and_fail;
-    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, connect_addr, &size) == -1)
-      goto tidy_up_and_fail;
-    /* 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);
-    fd[0] = connector;
-    fd[1] = acceptor;
-
-    return 0;
-
-  abort_tidy_up_and_fail:
-#ifdef _WIN32
-    saved_errno = WSAECONNABORTED;
-#else
-    saved_errno = ECONNABORTED; /* I hope this is portable and appropriate.  */
-#endif
-  tidy_up_and_fail:
-    if (saved_errno < 0)
-      saved_errno = errno;
-    if (SOCKET_OK(listener))
-      tor_close_socket(listener);
-    if (SOCKET_OK(connector))
-      tor_close_socket(connector);
-    if (SOCKET_OK(acceptor))
-      tor_close_socket(acceptor);
-    return -saved_errno;
-}
-
-#endif /* defined(NEED_ERSATZ_SOCKETPAIR) */
-
 /** Mockable wrapper for getsockname(). */
 MOCK_IMPL(int,
 tor_getsockname,(tor_socket_t sock, struct sockaddr *address,