From 94355e0146245c14012ac177461110d0a0c65f10 Mon Sep 17 00:00:00 2001
From: Lennart Poettering <lennart@poettering.net>
Date: Wed, 24 Jan 2018 19:54:26 +0100
Subject: [PATCH] core: add a new unit_needs_console() call

This call determines whether a specific unit currently needs access to
the console. It's a fancy wrapper around
exec_context_may_touch_console() ultimately, however for service units
we'll explicitly exclude the SERVICE_EXITED state from when we report
true.

(cherry picked from commit bb2c7685454842549bc1fe47adc35cbca2a84190)

Related: #1524359
---
 src/core/service.c | 27 +++++++++++++++++++++++++++
 src/core/unit.c    | 22 ++++++++++++++++++++++
 src/core/unit.h    |  5 +++++
 3 files changed, 54 insertions(+)

diff --git a/src/core/service.c b/src/core/service.c
index 1ad154e41f..8a8f4be149 100644
--- a/src/core/service.c
+++ b/src/core/service.c
@@ -3368,6 +3368,32 @@ static int service_control_pid(Unit *u) {
         return s->control_pid;
 }
 
+static bool service_needs_console(Unit *u) {
+        Service *s = SERVICE(u);
+
+        assert(s);
+
+        /* We provide our own implementation of this here, instead of relying of the generic implementation
+         * unit_needs_console() provides, since we want to return false if we are in SERVICE_EXITED state. */
+
+        if (!exec_context_may_touch_console(&s->exec_context))
+                return false;
+
+        return IN_SET(s->state,
+                      SERVICE_START_PRE,
+                      SERVICE_START,
+                      SERVICE_START_POST,
+                      SERVICE_RUNNING,
+                      SERVICE_RELOAD,
+                      SERVICE_STOP,
+                      SERVICE_STOP_SIGABRT,
+                      SERVICE_STOP_SIGTERM,
+                      SERVICE_STOP_SIGKILL,
+                      SERVICE_STOP_POST,
+                      SERVICE_FINAL_SIGTERM,
+                      SERVICE_FINAL_SIGKILL);
+}
+
 static const char* const service_restart_table[_SERVICE_RESTART_MAX] = {
         [SERVICE_RESTART_NO] = "no",
         [SERVICE_RESTART_ON_SUCCESS] = "on-success",
@@ -3489,6 +3515,7 @@ const UnitVTable service_vtable = {
         .bus_commit_properties = bus_service_commit_properties,
 
         .get_timeout = service_get_timeout,
+        .needs_console = service_needs_console,
         .can_transient = true,
 
         .status_message_formats = {
diff --git a/src/core/unit.c b/src/core/unit.c
index 4069a6f4c4..48358bc026 100644
--- a/src/core/unit.c
+++ b/src/core/unit.c
@@ -3699,6 +3699,28 @@ pid_t unit_main_pid(Unit *u) {
         return 0;
 }
 
+bool unit_needs_console(Unit *u) {
+        ExecContext *ec;
+        UnitActiveState state;
+
+        assert(u);
+
+        state = unit_active_state(u);
+
+        if (UNIT_IS_INACTIVE_OR_FAILED(state))
+                return false;
+
+        if (UNIT_VTABLE(u)->needs_console)
+                return UNIT_VTABLE(u)->needs_console(u);
+
+        /* If this unit type doesn't implement this call, let's use a generic fallback implementation: */
+        ec = unit_get_exec_context(u);
+        if (!ec)
+                return false;
+
+        return exec_context_may_touch_console(ec);
+}
+
 static const char* const unit_active_state_table[_UNIT_ACTIVE_STATE_MAX] = {
         [UNIT_ACTIVE] = "active",
         [UNIT_RELOADING] = "reloading",
diff --git a/src/core/unit.h b/src/core/unit.h
index 4a8bd79052..fa7de11645 100644
--- a/src/core/unit.h
+++ b/src/core/unit.h
@@ -408,6 +408,9 @@ struct UnitVTable {
         /* Returns the main PID if there is any defined, or 0. */
         pid_t (*control_pid)(Unit *u);
 
+        /* Returns true if the unit currently needs access to the console */
+        bool (*needs_console)(Unit *u);
+
         /* This is called for each unit type and should be used to
          * enumerate existing devices and load them. However,
          * everything that is loaded here should still stay in
@@ -627,6 +630,8 @@ pid_t unit_main_pid(Unit *u);
 const char *unit_active_state_to_string(UnitActiveState i) _const_;
 UnitActiveState unit_active_state_from_string(const char *s) _pure_;
 
+bool unit_needs_console(Unit *u);
+
 /* Macros which append UNIT= or USER_UNIT= to the message */
 
 #define log_unit_full_errno(unit, level, error, ...) log_object_internal(level, error, __FILE__, __LINE__, __func__, getpid() == 1 ? "UNIT=" : "USER_UNIT=", unit, __VA_ARGS__)