commit 70daa67062c016eea1a30be2e1de0dcba1d23a13
author Viorel Suman <viorel.suman@intel.com> Mon Mar 21 10:08:07 2016 +0200
committer Elliott Hughes <enh@google.com> Mon Mar 21 08:50:01 2016 -0700
tree b3c4055f181dd02576083cef9ec5df12b5ce0ada
parent ba44383197c8d5e1ca6ad32b67837c9aaf7ee224

Multiple consoles

This CL allows enabling of multiple consoles. A service can be
mapped to a specific console by providing the optional argument,
IE "tty0", to "console" service attribute as follows:

service fbconsole /system/bin/sh
    class core
    console tty0
    disabled
    user shell
    group shell log readproc
    seclabel u:r:shell:s0

Bug: None
Change-Id: I3b24e7f6848bbe5c6475f11334c04ec536e6af88
Tracked-On: https://jira01.devtools.intel.com/browse/BP-289
Signed-off-by: Viorel Suman <viorel.suman@intel.com>

init/service.cpp

diff --git a/init/service.cpp b/init/service.cpp
index bdecc32..e509f46 100644
--- a/init/service.cpp
+++ b/init/service.cpp
@@ -172,6 +172,7 @@
 
 bool Service::HandleConsole(const std::vector<std::string>& args, std::string* err) {
     flags_ |= SVC_CONSOLE;
+    console_ = args.size() > 1 ? "/dev/" + args[1] : "";
     return true;
 }
 
@@ -282,7 +283,7 @@
     constexpr std::size_t kMax = std::numeric_limits<std::size_t>::max();
     static const Map option_handlers = {
         {"class",       {1,     1,    &Service::HandleClass}},
-        {"console",     {0,     0,    &Service::HandleConsole}},
+        {"console",     {0,     1,    &Service::HandleConsole}},
         {"critical",    {0,     0,    &Service::HandleCritical}},
         {"disabled",    {0,     0,    &Service::HandleDisabled}},
         {"group",       {1,     NR_SVC_SUPP_GIDS + 1, &Service::HandleGroup}},
@@ -329,10 +330,18 @@
     }
 
     bool needs_console = (flags_ & SVC_CONSOLE);
-    if (needs_console && !have_console) {
-        ERROR("service '%s' requires console\n", name_.c_str());
-        flags_ |= SVC_DISABLED;
-        return false;
+    if (needs_console) {
+        if (console_.empty()) {
+            console_ = default_console;
+        }
+
+        bool have_console = (open(console_.c_str(), O_RDWR | O_CLOEXEC) != -1);
+        if (!have_console) {
+            ERROR("service '%s' couldn't open console '%s': %s\n",
+                  name_.c_str(), console_.c_str(), strerror(errno));
+            flags_ |= SVC_DISABLED;
+            return false;
+        }
     }
 
     struct stat sb;
@@ -606,10 +615,8 @@
 }
 
 void Service::OpenConsole() const {
-    int fd;
-    if ((fd = open(console_name.c_str(), O_RDWR)) < 0) {
-        fd = open("/dev/null", O_RDWR);
-    }
+    int fd = open(console_.c_str(), O_RDWR);
+    if (fd == -1) fd = open("/dev/null", O_RDWR);
     ioctl(fd, TIOCSCTTY, 0);
     dup2(fd, 0);
     dup2(fd, 1);