Attachment 140010 Details for Bug 106395 – sysdeps-unix: Handle errors from getaddrinfo correctly

[patch] sysdeps-unix: Handle errors from getaddrinfo correctly

0001-sysdeps-unix-Handle-errors-from-getaddrinfo-correctl.patch (text/plain), 5.16 KB, created by Simon McVittie on 2018-06-04 15:35:10 UTC

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Creator: Simon McVittie

Created: 2018-06-04 15:35:10 UTC

Size: 5.16 KB

patch

obsolete

>From 694a4ab9e8ad2deca230ae87adcd1cb476669a55 Mon Sep 17 00:00:00 2001
>From: Simon McVittie <smcv@collabora.com>
>Date: Mon, 4 Jun 2018 16:27:46 +0100
>Subject: [PATCH 1/5] sysdeps-unix: Handle errors from getaddrinfo correctly
>
>getaddrinfo and getnameinfo have their own error-handling convention
>in which the library call returns either 0 or an EAI_* error code
>unrelated to errno. If the error code is not EAI_SYSTEM, then
>the value of errno is undefined (in particular it might be carried
>over from a previous system call or library call). Introduce a
>new helper function _dbus_error_from_gai() to handle this.
>
>The equivalent code paths in Windows appear to be OK: the Windows
>implementation of getaddrinfo() is documented to return a Winsock
>error code, which we seem to be handling correctly.
>
>Signed-off-by: Simon McVittie <smcv@collabora.com>
>Bug: https://bugs.freedesktop.org/show_bug.cgi?id=106395
>---
> dbus/dbus-sysdeps-unix.c | 70 +++++++++++++++++++++++++++++++++++++---
> 1 file changed, 65 insertions(+), 5 deletions(-)
>
>diff --git a/dbus/dbus-sysdeps-unix.c b/dbus/dbus-sysdeps-unix.c
>index f802cace..0af3e4a2 100644
>--- a/dbus/dbus-sysdeps-unix.c
>+++ b/dbus/dbus-sysdeps-unix.c
>@@ -1325,6 +1325,56 @@ _dbus_listen_systemd_sockets (DBusSocket **fds,
> #endif
> }
> 
>+/* Convert an error code from getaddrinfo() or getnameinfo() into
>+ * a D-Bus error name. */
>+static const char *
>+_dbus_error_from_gai (int gai_res,
>+                      int saved_errno)
>+{
>+  switch (gai_res)
>+    {
>+#ifdef EAI_FAMILY
>+      case EAI_FAMILY:
>+        /* ai_family not supported (at all) */
>+        return DBUS_ERROR_NOT_SUPPORTED;
>+#endif
>+
>+#ifdef EAI_SOCKTYPE
>+      case EAI_SOCKTYPE:
>+        /* ai_socktype not supported (at all) */
>+        return DBUS_ERROR_NOT_SUPPORTED;
>+#endif
>+
>+#ifdef EAI_MEMORY
>+      case EAI_MEMORY:
>+        /* Out of memory */
>+        return DBUS_ERROR_NO_MEMORY;
>+#endif
>+
>+#ifdef EAI_SYSTEM
>+      case EAI_SYSTEM:
>+        /* Unspecified system error, details in errno */
>+        return _dbus_error_from_errno (saved_errno);
>+#endif
>+
>+      case 0:
>+        /* It succeeded, but we didn't get any addresses? */
>+        return DBUS_ERROR_FAILED;
>+
>+      /* EAI_AGAIN: Transient failure */
>+      /* EAI_BADFLAGS: invalid ai_flags (programming error) */
>+      /* EAI_FAIL: Non-recoverable failure */
>+      /* EAI_NODATA: host exists but has no addresses */
>+      /* EAI_NONAME: host does not exist */
>+      /* EAI_OVERFLOW: argument buffer overflow */
>+      /* EAI_SERVICE: service not available for specified socket
>+       * type (we should never see this because we use numeric
>+       * ports) */
>+      default:
>+        return DBUS_ERROR_FAILED;
>+    }
>+}
>+
> /**
>  * Creates a socket and connects to a socket at the given host
>  * and port. The connection fd is returned, and is set up as
>@@ -1386,7 +1436,7 @@ _dbus_connect_tcp_socket_with_nonce (const char     *host,
>   if ((res = getaddrinfo(host, port, &hints, &ai)) != 0)
>     {
>       dbus_set_error (error,
>-                      _dbus_error_from_errno (errno),
>+                      _dbus_error_from_gai (res, errno),
>                       "Failed to lookup host/port: \"%s:%s\": %s (%d)",
>                       host, port, gai_strerror(res), res);
>       _dbus_socket_invalidate (&fd);
>@@ -1545,7 +1595,7 @@ _dbus_listen_tcp_socket (const char     *host,
>   if ((res = getaddrinfo(host, port, &hints, &ai)) != 0 || !ai)
>     {
>       dbus_set_error (error,
>-                      _dbus_error_from_errno (errno),
>+                      _dbus_error_from_gai (res, errno),
>                       "Failed to lookup host/port: \"%s:%s\": %s (%d)",
>                       host ? host : "*", port, gai_strerror(res), res);
>       goto failed;
>@@ -1673,16 +1723,26 @@ _dbus_listen_tcp_socket (const char     *host,
>               addrlen = sizeof(addr);
>               result = getsockname(fd, (struct sockaddr*) &addr, &addrlen);
> 
>-              if (result == -1 ||
>-                  (res = getnameinfo ((struct sockaddr*)&addr, addrlen, NULL, 0,
>+              if (result == -1)
>+                {
>+                  saved_errno = errno;
>+                  dbus_set_error (error, _dbus_error_from_errno (saved_errno),
>+                                  "Failed to retrieve socket name for \"%s:%s\": %s",
>+                                  host ? host : "*", port, _dbus_strerror (saved_errno));
>+                  goto failed;
>+                }
>+
>+              if ((res = getnameinfo ((struct sockaddr*)&addr, addrlen, NULL, 0,
>                                       portbuf, sizeof(portbuf),
>                                       NI_NUMERICHOST | NI_NUMERICSERV)) != 0)
>                 {
>-                  dbus_set_error (error, _dbus_error_from_errno (errno),
>+                  saved_errno = errno;
>+                  dbus_set_error (error, _dbus_error_from_gai (res, saved_errno),
>                                   "Failed to resolve port \"%s:%s\": %s (%d)",
>                                   host ? host : "*", port, gai_strerror(res), res);
>                   goto failed;
>                 }
>+
>               if (!_dbus_string_append(retport, portbuf))
>                 {
>                   dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
>-- 
>2.17.1
>

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