stream-tcp: Change the connection name for pwindows.

As of now, when someone passes a punix:foo/bar as a connection type
in Windows, we create a TCP server using 127.0.0.1 and save the kernel
assigned port number in the file foo/bar. The connection name
as obtained through pstream_get_name() would be ptcp:127.0.0.1:$PORT.
This was okay if pstream_get_name() was only used for logging
purposes. But netdev-dummy uses it to close active connections when the
passed name and created name are different. This causes transient
connection teardowns while using patch ports in Windows unit tests
causing occasional packet loss.

This commit sets the connection name to be punix:foo/bar instead
of ptcp:127.0.0.1:$PORT for pwindows.

Signed-off-by: Gurucharan Shetty <[email protected]>
Acked-by: Ben Pfaff <[email protected]>

lib/stream-tcp.c

@@ -154,15 +154,16 @@ static int ptcp_accept(int fd, const struct sockaddr_storage *,
                        size_t, struct stream **streamp);
 
 static int
-new_pstream(char *suffix, struct pstream **pstreamp, int dscp,
-            char *unlink_path, bool kernel_print_port)
+new_pstream(char *suffix, const char *name, struct pstream **pstreamp,
+            int dscp, char *unlink_path, bool kernel_print_port)
 {
     char bound_name[SS_NTOP_BUFSIZE + 16];
     char addrbuf[SS_NTOP_BUFSIZE];
     struct sockaddr_storage ss;
     int error;
     uint16_t port;
     int fd;
+    char *conn_name = CONST_CAST(char *, name);
 
     fd = inet_open_passive(SOCK_STREAM, suffix, -1, &ss, dscp,
                            kernel_print_port);
@@ -171,10 +172,13 @@ new_pstream(char *suffix, struct pstream **pstreamp, int dscp,
     }
 
     port = ss_get_port(&ss);
-    snprintf(bound_name, sizeof bound_name, "ptcp:%"PRIu16":%s",
-             port, ss_format_address(&ss, addrbuf, sizeof addrbuf));
+    if (!conn_name) {
+        snprintf(bound_name, sizeof bound_name, "ptcp:%"PRIu16":%s",
+                 port, ss_format_address(&ss, addrbuf, sizeof addrbuf));
+        conn_name = bound_name;
+    }
 
-    error = new_fd_pstream(bound_name, fd, ptcp_accept, set_dscp, unlink_path,
+    error = new_fd_pstream(conn_name, fd, ptcp_accept, set_dscp, unlink_path,
                            pstreamp);
     if (!error) {
         pstream_set_bound_port(*pstreamp, htons(port));
@@ -186,7 +190,7 @@ static int
 ptcp_open(const char *name OVS_UNUSED, char *suffix, struct pstream **pstreamp,
           uint8_t dscp)
 {
-    return new_pstream(suffix, pstreamp, dscp, NULL, true);
+    return new_pstream(suffix, NULL, pstreamp, dscp, NULL, true);
 }
 
 static int
@@ -214,8 +218,8 @@ const struct pstream_class ptcp_pstream_class = {
 
 #ifdef _WIN32
 static int
-pwindows_open(const char *name OVS_UNUSED, char *suffix,
-              struct pstream **pstreamp, uint8_t dscp)
+pwindows_open(const char *name, char *suffix, struct pstream **pstreamp,
+              uint8_t dscp)
 {
     int error;
     char *suffix_new, *path;
@@ -232,7 +236,7 @@ pwindows_open(const char *name OVS_UNUSED, char *suffix,
         path = xstrdup(suffix);
     }
 
-    error = new_pstream(suffix_new, pstreamp, dscp, path, false);
+    error = new_pstream(suffix_new, name, pstreamp, dscp, path, false);
     if (error) {
         goto exit;
     }