[PATCH] weston-launch exports listed environment variables

[José Bollo]

Enable weston-launch to export the environment
variables listed with the invocation option
--export (shortened as -e).

The values of the variables are read from the
environment of weston-launch to ensure they
aren't displayed by the unix command 'ps'.

Example:
  weston-launch --export=DBUS_SESSION_BUS_ADDRESS

In the above example, the environment variable
DBUS_SESSION_BUS_ADDRESS is passed to weston.

Note: weston-launch launches the process within
a login shell. So most of the environment variables
are set through the standard process. Then the
option --export is intended to be used only when
the standard way is missing some contextual point.
---
 src/weston-launch.c | 32 +++++++++++++++++++++++++++++++-
 1 file changed, 31 insertions(+), 1 deletion(-)

diff --git a/src/weston-launch.c b/src/weston-launch.c
index 525c61c..ea59e05 100644
--- a/src/weston-launch.c
+++ b/src/weston-launch.c
@@ -85,6 +85,13 @@ struct weston_launch {
 
 union cmsg_data { unsigned char b[4]; int fd; };
 
+struct reexport {
+    struct reexport * next;
+    char * name, * value;
+};
+
+static struct reexport * reexport_head = NULL;
+
 static gid_t *
 read_groups(void)
 {
@@ -527,6 +534,7 @@ setup_session(struct weston_launch *wl)
 	char **env;
 	char *term;
 	int i;
+	struct reexport * reexport = reexport_head;
 
 	if (wl->tty != STDIN_FILENO) {
 		if (setsid() < 0)
@@ -537,6 +545,10 @@ setup_session(struct weston_launch *wl)
 
 	term = getenv("TERM");
 	clearenv();
+	while (reexport != NULL) {
+		setenv(reexport->name, reexport->value, 1);
+		reexport = reexport->next;
+	}
 	if (term)
 		setenv("TERM", term, 1);
 	setenv("USER", wl->pw->pw_name, 1);
@@ -610,6 +622,7 @@ help(const char *name)
 	fprintf(stderr, "Usage: %s [args...] [-- [weston args..]]\n", name);
 	fprintf(stderr, "  -u, --user      Start session as specified username
\n");
 	fprintf(stderr, "  -t, --tty       Start session on alternative tty
\n");
+	fprintf(stderr, "  -e, --export    (re-)Export the given environment
variable\n");
 	fprintf(stderr, "  -v, --verbose   Be verbose\n");
 	fprintf(stderr, "  -h, --help      Display this help message\n");
 }
@@ -620,9 +633,11 @@ main(int argc, char *argv[])
 	struct weston_launch wl;
 	int i, c;
 	char *tty = NULL;
+	struct reexport **reexport = &reexport_head;
 	struct option opts[] = {
 		{ "user",    required_argument, NULL, 'u' },
 		{ "tty",     required_argument, NULL, 't' },
+		{ "export",  required_argument, NULL, 'e' },
 		{ "verbose", no_argument,       NULL, 'v' },
 		{ "help",    no_argument,       NULL, 'h' },
 		{ 0,         0,                 NULL,  0  }
@@ -630,7 +645,7 @@ main(int argc, char *argv[])
 
 	memset(&wl, 0, sizeof wl);
 
-	while ((c = getopt_long(argc, argv, "u:t::vh", opts, &i)) != -1) {
+	while ((c = getopt_long(argc, argv, "u:t::e:vh", opts, &i)) != -1) {
 		switch (c) {
 		case 'u':
 			wl.new_user = optarg;
@@ -640,6 +655,21 @@ main(int argc, char *argv[])
 		case 't':
 			tty = optarg;
 			break;
+		case 'e':
+			if (getenv(optarg) == NULL) 
+				error(1, 0, "Environment variable '%s' not found.", optarg);
+			else {
+				*reexport = malloc(sizeof (struct reexport));
+				if (*reexport == NULL) {
+					error(1, 0, "Memory depletion.");
+					exit(EXIT_FAILURE);
+				}
+				(*reexport)->name = optarg;
+				(*reexport)->value = getenv(optarg);
+				reexport = &((*reexport)->next);
+				*reexport = NULL;
+			}
+			break;
 		case 'v':
 			wl.verbose = 1;
 			break;
-- 
1.8.1.4