bpo-30205: Fix getsockname() for unbound AF_UNIX sockets on Linux (#1370)

* bpo-30205: Fix getsockname() for unbound AF_UNIX sockets on Linux

* Add NEWS entry

diff --git a/Lib/test/test_socket.py b/Lib/test/test_socket.py
index 2155d630dd4790673a8cc4cd78b2f22f5ada1757..5e37fc608f26ad2323701c287fa1490fa6a8ee20 100644 (file)
--- a/Lib/test/test_socket.py
+++ b/Lib/test/test_socket.py
@@ -4682,6 +4682,10 @@ class TestUnixDomain(unittest.TestCase):
             else:
                 raise
 
+    def testUnbound(self):
+        # Issue #30205
+        self.assertEqual(self.sock.getsockname(), '')
+
     def testStrAddr(self):
         # Test binding to and retrieving a normal string pathname.
         path = os.path.abspath(support.TESTFN)

diff --git a/Misc/NEWS b/Misc/NEWS
index 118483f9437ed4ad46fab4ea2811fa17be581b05..c3eaaf2d4df66457d152dc143a41b1f636042660 100644 (file)
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -317,6 +317,8 @@ Extension Modules
 Library
 -------
 
+- bpo-30205: Fix getsockname() for unbound AF_UNIX sockets on Linux.
+
 - bpo-30228: The seek() and tell() methods of io.FileIO now set the internal
   seekable attribute to avoid one syscall on open() (in buffered or text mode).
 

diff --git a/Modules/socketmodule.c b/Modules/socketmodule.c
index 6d5c256ff340d69ea9b9f173648f4192c2de8d3a..456c66478e969191dc92b274f6f7e798289d3df1 100644 (file)
--- a/Modules/socketmodule.c
+++ b/Modules/socketmodule.c
@@ -1211,9 +1211,9 @@ makesockaddr(SOCKET_T sockfd, struct sockaddr *addr, size_t addrlen, int proto)
     {
         struct sockaddr_un *a = (struct sockaddr_un *) addr;
 #ifdef __linux__
-        if (a->sun_path[0] == 0) {  /* Linux abstract namespace */
-            addrlen -= offsetof(struct sockaddr_un, sun_path);
-            return PyBytes_FromStringAndSize(a->sun_path, addrlen);
+        size_t linuxaddrlen = addrlen - offsetof(struct sockaddr_un, sun_path);
+        if (linuxaddrlen > 0 && a->sun_path[0] == 0) {  /* Linux abstract namespace */
+            return PyBytes_FromStringAndSize(a->sun_path, linuxaddrlen);
         }
         else
 #endif /* linux */