make fork_execv_on_steroids capable of setting env vars too

Before, it could only unset them.

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>

2 files changed, 16 insertions, 10 deletions

diff --git a/src/lib/run_event.c b/src/lib/run_event.c
index a2bbc76b..3d2b3a22 100644
--- a/src/lib/run_event.c
+++ b/src/lib/run_event.c
@@ -245,18 +245,19 @@ int spawn_next_command(struct run_event_state *state,
     VERB1 log("Executing '%s'", cmd);
 
     /* Export some useful environment variables for children */
+    char *env_vec[3];
     /* Just exporting dump_dir_name isn't always ok: it can be "."
      * and some children want to cd to other directory but still
      * be able to find dump directory by using $DUMP_DIR...
      */
     char *full_name = realpath(dump_dir_name, NULL);
-    setenv("DUMP_DIR", (full_name ? full_name : dump_dir_name), 1);
+    env_vec[0] = xasprintf("DUMP_DIR=%s", (full_name ? full_name : dump_dir_name));
     free(full_name);
-    setenv("EVENT", event, 1);
-//FIXME: set vars in the child, not here! Need to improve fork_execv_on_steroids...
+    env_vec[1] = xasprintf("EVENT=%s", event);
+    env_vec[2] = NULL;
 
     char *argv[4];
-    argv[0] = (char*)"/bin/sh";
+    argv[0] = (char*)"/bin/sh"; // TODO: honor $SHELL?
     argv[1] = (char*)"-c";
     argv[2] = cmd;
     argv[3] = NULL;
@@ -266,12 +267,15 @@ int spawn_next_command(struct run_event_state *state,
                 EXECFLG_INPUT_NUL + EXECFLG_OUTPUT + EXECFLG_ERR2OUT,
                 argv,
                 pipefds,
-                /* unsetenv_vec: */ NULL,
+                /* env_vec: */ env_vec,
                 /* dir: */ dump_dir_name,
                 /* uid(unused): */ 0
     );
     state->command_out_fd = pipefds[0];
 
+    free(env_vec[0]);
+    free(env_vec[1]);
+
     state->commands = g_list_remove(state->commands, cmd);
 
     return 0;
diff --git a/src/lib/spawn.c b/src/lib/spawn.c
index f6b7263c..188b63bd 100644
--- a/src/lib/spawn.c
+++ b/src/lib/spawn.c
@@ -32,7 +32,7 @@ static char *concat_str_vector(char **strings)
 pid_t fork_execv_on_steroids(int flags,
 		char **argv,
 		int *pipefds,
-		char **unsetenv_vec,
+		char **env_vec,
 		const char *dir,
 		uid_t uid)
 {
@@ -69,9 +69,11 @@ pid_t fork_execv_on_steroids(int flags,
 			xsetreuid(uid, uid);
 		}
 
-		if (unsetenv_vec) {
-			while (*unsetenv_vec)
-				unsetenv(*unsetenv_vec++);
+		if (env_vec) {
+			/* Note: we use the glibc extension that putenv("var")
+			 * *unsets* $var if "var" string has no '=' */
+			while (*env_vec)
+				putenv(*env_vec++);
 		}
 
 		/* Play with stdio descriptors */
@@ -134,7 +136,7 @@ char *run_in_shell_and_save_output(int flags,
 	const char *argv[] = { "/bin/sh", "-c", cmd, NULL };
 	int pipeout[2];
 	pid_t child = fork_execv_on_steroids(flags, (char **)argv, pipeout,
-		/*unsetenv_vec:*/ NULL, dir, /*uid (unused):*/ 0);
+		/*env_vec:*/ NULL, dir, /*uid (unused):*/ 0);
 
 	size_t pos = 0;
 	char *result = NULL;