From b79e076e5e89bdede708e689cb18a0e9f1280449 Mon Sep 17 00:00:00 2001
From: Tom Cherry <tomcherry@google.com>
Date: Tue, 7 Jun 2016 11:22:00 -0700
Subject: [PATCH] init: expand arguments of services when they start

Arguments of commands are expanded based on properties if they contain
${property.name}, however this is not currently done for arguments of
services.

This patch makes it that arguments of services are expanded each time
that the service starts at the point immediately before execve().

Bug: 28788401
Change-Id: Iba581a8377e25a6478d4d2ec2e8b29e181d8640c
---
 init/service.cpp | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/init/service.cpp b/init/service.cpp
index f1ffa189f..3149f8e64 100644
--- a/init/service.cpp
+++ b/init/service.cpp
@@ -460,13 +460,21 @@ bool Service::Start() {
             }
         }
 
+        std::vector<std::string> expanded_args;
         std::vector<char*> strs;
-        for (const auto& s : args_) {
-            strs.push_back(const_cast<char*>(s.c_str()));
+        expanded_args.resize(args_.size());
+        strs.push_back(const_cast<char*>(args_[0].c_str()));
+        for (std::size_t i = 1; i < args_.size(); ++i) {
+            if (!expand_props(args_[i], &expanded_args[i])) {
+                ERROR("%s: cannot expand '%s'\n", args_[0].c_str(), args_[i].c_str());
+                _exit(127);
+            }
+            strs.push_back(const_cast<char*>(expanded_args[i].c_str()));
         }
         strs.push_back(nullptr);
-        if (execve(args_[0].c_str(), (char**) &strs[0], (char**) ENV) < 0) {
-            ERROR("cannot execve('%s'): %s\n", args_[0].c_str(), strerror(errno));
+
+        if (execve(strs[0], (char**) &strs[0], (char**) ENV) < 0) {
+            ERROR("cannot execve('%s'): %s\n", strs[0], strerror(errno));
         }
 
         _exit(127);