[Libguestfs] [PATCH libnbd v2 4/4] generator/states-connect-socket-activation.c: Set LISTEN_FDNAMES

[Richard W.M. Jones]

When the user calls nbd_set_socket_activation_name before calling
nbd_connect_system_socket_activation, pass the name down to the server
through LISTEN_FDNAMES.  This has no effect unless the new API has
been called to set the socket name to a non-empty string.
---
 generator/states-connect-socket-activation.c | 35 +++++++++++++++-----
 1 file changed, 26 insertions(+), 9 deletions(-)

diff --git a/generator/states-connect-socket-activation.c b/generator/states-connect-socket-activation.c
index 24544018fb..2ff191bb9f 100644
--- a/generator/states-connect-socket-activation.c
+++ b/generator/states-connect-socket-activation.c
@@ -22,6 +22,7 @@
 
 #include <stdio.h>
 #include <stdlib.h>
+#include <stdbool.h>
 #include <string.h>
 #include <unistd.h>
 #include <errno.h>
@@ -38,20 +39,27 @@ extern char **environ;
 
 /* Prepare environment for calling execvp when doing systemd socket
  * activation.  Takes the current environment and copies it.  Removes
- * any existing LISTEN_PID or LISTEN_FDS and replaces them with new
- * variables.  env[0] is "LISTEN_PID=..." which is filled in by
- * CONNECT_SA.START, and env[1] is "LISTEN_FDS=1".
+ * any existing LISTEN_PID, LISTEN_FDS or LISTEN_FDNAAMES, and
+ * replaces them with new variables.
+ *
+ * env[0] is "LISTEN_PID=..." which is filled in by CONNECT_SA.START
+ *
+ * env[1] is "LISTEN_FDS=1"
+ *
+ * env[2] (if used) is "LISTEN_FDNAMES=" + h->sa_name
  */
 static int
-prepare_socket_activation_environment (string_vector *env)
+prepare_socket_activation_environment (struct nbd_handle *h,
+                                       string_vector *env)
 {
   char *p;
   size_t i;
+  const bool using_name = h->sa_name != NULL;
 
   assert (env->len == 0);
 
-  /* Reserve slots env[0]..env[1] */
-  if (string_vector_reserve (env, 2) == -1)
+  /* Reserve slots in env. */
+  if (string_vector_reserve (env, using_name ? 3 : 2) == -1)
     goto err;
   p = strdup ("LISTEN_PID=xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx");
   if (p == NULL)
@@ -61,11 +69,20 @@ prepare_socket_activation_environment (string_vector *env)
   if (p == NULL)
     goto err;
   string_vector_append (env, p);
+  if (using_name) {
+    if (asprintf (&p, "LISTEN_FDNAMES=%s", h->sa_name) == -1)
+      goto err;
+    string_vector_append (env, p);
+  }
 
-  /* Append the current environment, but remove LISTEN_PID, LISTEN_FDS. */
+  /* Append the current environment, but remove the special
+   * environment variables.
+   */
   for (i = 0; environ[i] != NULL; ++i) {
     if (strncmp (environ[i], "LISTEN_PID=", strlen ("LISTEN_PID=")) != 0 &&
-        strncmp (environ[i], "LISTEN_FDS=", strlen ("LISTEN_FDS=")) != 0) {
+        strncmp (environ[i], "LISTEN_FDS=", strlen ("LISTEN_FDS=")) != 0 &&
+        strncmp (environ[i], "LISTEN_FDNAMES=",
+                 strlen ("LISTEN_FDNAMES=")) != 0) {
       char *copy = strdup (environ[i]);
       if (copy == NULL)
         goto err;
@@ -148,7 +165,7 @@  CONNECT_SA.START:
     return 0;
   }
 
-  if (prepare_socket_activation_environment (&env) == -1) {
+  if (prepare_socket_activation_environment (h, &env) == -1) {
     SET_NEXT_STATE (%.DEAD);
     close (s);
     return 0;
-- 
2.39.0