Add extra_args to exec_child()

Related:
    https://fedorahosted.org/sssd/ticket/2503

Currently all child processes use the same arguments, the construction
of argv[] is even hardcoded in exec_child(). Add an extra_args[] array
that extends the common set of argvs so that we can have child-specific
arguments. Also adds a unit test.

Reviewed-by: Sumit Bose <sbose@redhat.com>

2 files changed, 23 insertions, 3 deletions

diff --git a/src/util/child_common.c b/src/util/child_common.c
index cc6a8fa75..9710630f9 100644
--- a/src/util/child_common.c
+++ b/src/util/child_common.c
@@ -623,6 +623,7 @@ static void child_invoke_callback(struct tevent_context *ev,
 static errno_t prepare_child_argv(TALLOC_CTX *mem_ctx,
                                   int child_debug_fd,
                                   const char *binary,
+                                  const char *extra_argv[],
                                   char ***_argv)
 {
     /*
@@ -632,6 +633,7 @@ static errno_t prepare_child_argv(TALLOC_CTX *mem_ctx,
     uint_t argc = 5;
     char ** argv;
     errno_t ret = EINVAL;
+    size_t i;
 
     /* Save the current state in case an interrupt changes it */
     bool child_debug_to_file = debug_to_file;
@@ -642,6 +644,10 @@ static errno_t prepare_child_argv(TALLOC_CTX *mem_ctx,
     if (child_debug_to_file) argc++;
     if (child_debug_stderr) argc++;
 
+    if (extra_argv) {
+        for (i = 0; extra_argv[i]; i++) argc++;
+    }
+
     /*
      * program name, debug_level, debug_to_file, debug_timestamps,
      * debug_microseconds and NULL
@@ -654,6 +660,17 @@ static errno_t prepare_child_argv(TALLOC_CTX *mem_ctx,
 
     argv[--argc] = NULL;
 
+    /* Add extra_attrs first */
+    if (extra_argv) {
+        for (i = 0; extra_argv[i]; i++) {
+            argv[--argc] = talloc_strdup(argv, extra_argv[i]);
+            if (argv[argc] == NULL) {
+                ret = ENOMEM;
+                goto fail;
+            }
+        }
+    }
+
     argv[--argc] = talloc_asprintf(argv, "--debug-level=%#.4x",
                               debug_level);
     if (argv[argc] == NULL) {
@@ -714,7 +731,8 @@ fail:
 
 errno_t exec_child(TALLOC_CTX *mem_ctx,
                    int *pipefd_to_child, int *pipefd_from_child,
-                   const char *binary, int debug_fd)
+                   const char *binary, int debug_fd,
+                   const char *extra_argv[])
 {
     int ret;
     errno_t err;
@@ -739,7 +757,8 @@ errno_t exec_child(TALLOC_CTX *mem_ctx,
     }
 
     ret = prepare_child_argv(mem_ctx, debug_fd,
-                             binary, &argv);
+                             binary, extra_argv,
+                             &argv);
     if (ret != EOK) {
         DEBUG(SSSDBG_CRIT_FAILURE, "prepare_child_argv.\n");
         return ret;
diff --git a/src/util/child_common.h b/src/util/child_common.h
index e159719a2..e659388ec 100644
--- a/src/util/child_common.h
+++ b/src/util/child_common.h
@@ -114,7 +114,8 @@ void child_sig_handler(struct tevent_context *ev,
 /* Never returns EOK, ether returns an error, or doesn't return on success */
 errno_t exec_child(TALLOC_CTX *mem_ctx,
                    int *pipefd_to_child, int *pipefd_from_child,
-                   const char *binary, int debug_fd);
+                   const char *binary, int debug_fd,
+                   const char *extra_argv[]);
 
 void child_cleanup(int readfd, int writefd);