From b9d470a3f42d0a9e12238711e25653276ab157e6 Mon Sep 17 00:00:00 2001
From: Felix Fietkau <nbd@openwrt.org>
Date: Fri, 14 Oct 2011 01:19:06 +0200
Subject: [PATCH] proto-shell: allow proto handlers to export variables to
 child processes

---
 dummy/netifd-proto.sh | 17 ++++++++++++++
 proto-shell.c         | 54 ++++++++++++++++++++++++++++++++-----------
 2 files changed, 57 insertions(+), 14 deletions(-)

diff --git a/dummy/netifd-proto.sh b/dummy/netifd-proto.sh
index 0f703a2..48b1292 100755
--- a/dummy/netifd-proto.sh
+++ b/dummy/netifd-proto.sh
@@ -33,6 +33,8 @@ _proto_do_teardown() {
 
 _proto_do_setup() {
 	json_load "$data"
+	_EXPORT_VAR=0
+	_EXPORT_VARS=
 	eval "$1_setup \"$interface\" \"$ifname\""
 }
 
@@ -143,6 +145,13 @@ proto_send_update() {
 	_proto_notify "$interface"
 }
 
+proto_export() {
+	local var="VAR${_EXPORT_VAR}"
+	_EXPORT_VAR="$(($_EXPORT_VAR + 1))"
+	export -- "$var=$1"
+	jshn_append _EXPORT_VARS "$var"
+}
+
 proto_run_command() {
 	local interface="$1"; shift
 
@@ -153,6 +162,14 @@ proto_run_command() {
 		json_add_string "" "$1"
 		shift
 	done
+	json_close_array
+	[ -n "$_EXPORT_VARS" ] && {
+		json_add_array env
+		for var in $_EXPORT_VARS; do
+			eval "json_add_string \"\" \"\${$var}\""
+		done
+		json_close_array
+	}
 	_proto_notify "$interface"
 }
 
diff --git a/proto-shell.c b/proto-shell.c
index 127a79d..e554d79 100644
--- a/proto-shell.c
+++ b/proto-shell.c
@@ -55,7 +55,7 @@ kill_process(struct uloop_process *proc)
 }
 
 static int
-start_process(const char **argv, struct uloop_process *proc)
+start_process(const char **argv, char **env, struct uloop_process *proc)
 {
 	int pid;
 
@@ -65,6 +65,12 @@ start_process(const char **argv, struct uloop_process *proc)
 		return -1;
 
 	if (!pid) {
+		if (env) {
+			while (*env) {
+				putenv(*env);
+				env++;
+			}
+		}
 		fchdir(proto_fd);
 		execvp(argv[0], (char **) argv);
 		exit(127);
@@ -121,7 +127,7 @@ proto_shell_handler(struct interface_proto_state *proto,
 		argv[i++] = proto->iface->main_dev.dev->ifname;
 	argv[i] = NULL;
 
-	ret = start_process(argv, proc);
+	ret = start_process(argv, NULL, proc);
 	free(config);
 
 	return ret;
@@ -305,10 +311,10 @@ proto_shell_parse_route_list(struct interface *iface, struct blob_attr *attr,
 	}
 }
 
-
 enum {
 	NOTIFY_ACTION,
 	NOTIFY_COMMAND,
+	NOTIFY_ENV,
 	NOTIFY_SIGNAL,
 	NOTIFY_LINK_UP,
 	NOTIFY_IFNAME,
@@ -325,6 +331,7 @@ enum {
 static const struct blobmsg_policy notify_attr[__NOTIFY_LAST] = {
 	[NOTIFY_ACTION] = { .name = "action", .type = BLOBMSG_TYPE_INT32 },
 	[NOTIFY_COMMAND] = { .name = "command", .type = BLOBMSG_TYPE_ARRAY },
+	[NOTIFY_ENV] = { .name = "env", .type = BLOBMSG_TYPE_ARRAY },
 	[NOTIFY_SIGNAL] = { .name = "signal", .type = BLOBMSG_TYPE_INT32 },
 	[NOTIFY_LINK_UP] = { .name = "link-up", .type = BLOBMSG_TYPE_BOOL },
 	[NOTIFY_IFNAME] = { .name = "ifname", .type = BLOBMSG_TYPE_STRING },
@@ -393,30 +400,49 @@ proto_shell_update_link(struct proto_shell_state *state, struct blob_attr **tb)
 	return 0;
 }
 
-static int
-proto_shell_run_command(struct proto_shell_state *state, struct blob_attr **tb)
+static bool
+fill_string_list(struct blob_attr *attr, char **argv, int max)
 {
 	struct blob_attr *cur;
-	char *argv[64];
 	int argc = 0;
 	int rem;
 
-	if (!tb[NOTIFY_COMMAND])
-		goto error;
+	if (!attr)
+		goto out;
 
-	blobmsg_for_each_attr(cur, tb[NOTIFY_COMMAND], rem) {
+	blobmsg_for_each_attr(cur, attr, rem) {
 		if (blobmsg_type(cur) != BLOBMSG_TYPE_STRING)
-			goto error;
+			return false;
 
 		if (!blobmsg_check_attr(cur, NULL))
-			goto error;
+			return false;
 
 		argv[argc++] = blobmsg_data(cur);
-		if (argc == ARRAY_SIZE(argv) - 1)
-			goto error;
+		if (argc == max - 1)
+			return false;
 	}
+
+out:
 	argv[argc] = NULL;
-	start_process((const char **) argv, &state->proto_task);
+	return true;
+}
+
+static int
+proto_shell_run_command(struct proto_shell_state *state, struct blob_attr **tb)
+{
+	char *argv[64];
+	char *env[32];
+
+	if (!tb[NOTIFY_COMMAND])
+		goto error;
+
+	if (!fill_string_list(tb[NOTIFY_COMMAND], argv, ARRAY_SIZE(argv)))
+		goto error;
+
+	if (!fill_string_list(tb[NOTIFY_ENV], env, ARRAY_SIZE(env)))
+		goto error;
+
+	start_process((const char **) argv, (char **) env, &state->proto_task);
 
 	return 0;
 
-- 
2.25.1