Make errors retrievable from tor_socketpair; resolve bug 163.

svn:r4509

src/common/compat.c

@@ -294,15 +294,17 @@ set_socket_nonblocking(int socket)
  * be able to read while localhost is down later (the socket pair may
  * even close, depending on OS-specific timeouts).
  *
- * XXX Bug: this function assumes errno is how you report errors, but
- * that isn't the case for Windows, which is where it's most likely
- * to be called.
+ * Returns 0 on success and -errno on failure; do not rely on the value
+ * of errno or WSAGetLastSocketError().
  **/
+/* It would be nicer just to set errno, but that won't work for windows. */
 int
 tor_socketpair(int family, int type, int protocol, int fd[2])
 {
 #ifdef HAVE_SOCKETPAIR
-    return socketpair(family, type, protocol, fd);
+  int r;
+  r = socketpair(family, type, protocol, fd);
+  return r < 0 ? -errno : r;
 #else
     /* This socketpair does not work when localhost is down. So
      * it's really not the same thing at all. But it's close enough
@@ -315,6 +317,7 @@ tor_socketpair(int family, int type, int protocol, int fd[2])
     struct sockaddr_in listen_addr;
     struct sockaddr_in connect_addr;
     int size;
+    int saved_errno = -1;
 
     if (protocol
 #ifdef AF_UNIX
@@ -322,24 +325,22 @@ tor_socketpair(int family, int type, int protocol, int fd[2])
 #endif
         ) {
 #ifdef MS_WINDOWS
-        errno = WSAEAFNOSUPPORT;
+      return -WSAEAFNOSUPPORT;
 #else
-        errno = EAFNOSUPPORT;
+      return -EAFNOSUPPORT;
 #endif
-        return -1;
     }
     if (!fd) {
-        errno = EINVAL;
-        return -1;
+      return -EINVAL;
     }
 
     listener = socket(AF_INET, type, 0);
     if (listener == -1)
-      return -1;
+      return -tor_socket_errno(-1);
     if (!SOCKET_IS_POLLABLE(listener)) {
       log_fn(LOG_WARN, "Too many connections; can't open socketpair");
       tor_close_socket(listener);
-      return -1;
+      return -ENCONN;
     }
     memset(&listen_addr, 0, sizeof(listen_addr));
     listen_addr.sin_family = AF_INET;
@@ -396,22 +397,20 @@ tor_socketpair(int family, int type, int protocol, int fd[2])
 
   abort_tidy_up_and_fail:
 #ifdef MS_WINDOWS
-  errno = WSAECONNABORTED;
+    saved_errno = WSAECONNABORTED;
 #else
-  errno = ECONNABORTED; /* I hope this is portable and appropriate.  */
+    saved_errno = ECONNABORTED; /* I hope this is portable and appropriate.  */
 #endif
   tidy_up_and_fail:
-    {
-        int save_errno = errno;
+    if (saved_errno < 0)
+      saved_errno = errno;
     if (listener != -1)
       tor_close_socket(listener);
     if (connector != -1)
       tor_close_socket(connector);
     if (acceptor != -1)
       tor_close_socket(acceptor);
-        errno = save_errno;
-        return -1;
-    }
+    return -saved_errno;
 #endif
 }
 

src/or/connection_edge.c

@@ -1207,12 +1207,13 @@ connection_ap_make_bridge(char *address, uint16_t port)
 {
   int fd[2];
   connection_t *conn;
+  int err;
 
   log_fn(LOG_INFO,"Making AP bridge to %s:%d ...",safe_str(address),port);
 
-  if (tor_socketpair(AF_UNIX, SOCK_STREAM, 0, fd) < 0) {
+  if ((err = tor_socketpair(AF_UNIX, SOCK_STREAM, 0, fd)) < 0) {
     log(LOG_WARN,"Couldn't construct socketpair (%s). Network down? Delaying.",
-        tor_socket_strerror(tor_socket_errno(-1)));
+        tor_socket_strerror(-err));
     return -1;
   }
 

src/or/cpuworker.c

@@ -301,11 +301,11 @@ spawn_cpuworker(void)
   int *fdarray;
   int fd;
   connection_t *conn;
+  int err;
 
   fdarray = tor_malloc(sizeof(int)*2);
-  if (tor_socketpair(AF_UNIX, SOCK_STREAM, 0, fdarray) < 0) {
-    log(LOG_ERR, "Couldn't construct socketpair: %s",
-        tor_socket_strerror(tor_socket_errno(-1)));
+  if ((err = tor_socketpair(AF_UNIX, SOCK_STREAM, 0, fdarray)) < 0) {
+    log(LOG_ERR, "Couldn't construct socketpair: %s", tor_socket_strerror(-err));
     tor_cleanup();
     tor_free(fdarray);
     exit(1);

src/or/dns.c

@@ -824,11 +824,11 @@ spawn_dnsworker(void)
   int *fdarray;
   int fd;
   connection_t *conn;
+  int err;
 
   fdarray = tor_malloc(sizeof(int)*2);
-  if (tor_socketpair(AF_UNIX, SOCK_STREAM, 0, fdarray) < 0) {
-    log(LOG_ERR, "Couldn't construct socketpair: %s",
-        tor_socket_strerror(tor_socket_errno(-1)));
+  if ((err = tor_socketpair(AF_UNIX, SOCK_STREAM, 0, fdarray)) < 0) {
+    log(LOG_ERR, "Couldn't construct socketpair: %s", tor_socket_strerror(-err));
     tor_cleanup();
     tor_free(fdarray);
     exit(1);