initctl: monitor and condition control over the bus

The bus can already answer questions and change services, so give
initctl the two things it still did another way: watching signals as
they happen, and getting or setting user conditions.

The dbus tests move with it, split by area rather than one file that
grew every time the library did.

Signed-off-by: Joachim Wiberg <troglobit@gmail.com>

test/dbus-cond.sh

@@ -0,0 +1,69 @@
+#!/bin/sh
+# libink: org.finit.Cond1 vtable + ConditionChanged signal.
+#
+# Covers user-condition manipulation: Get, Set (with signal fan-out),
+# the usr/* policy guard (non-usr conditions are rejected), and the
+# non-root authorization gate.
+
+set -eu
+
+TEST_DIR=$(dirname "$0")
+
+# shellcheck source=/dev/null
+. "$TEST_DIR/lib/setup.sh"
+# shellcheck source=/dev/null
+. "$TEST_DIR/lib/dbus-setup.sh"
+
+say "Cond1.Get returns 'off' for an unset condition"
+result=$(texec "$CLIENT" call-s "$BUS" /org/finit/cond \
+    org.finit.Cond1 Get "no-such-cond")
+case "$result" in
+    OK*) : ;;   # ok, the cond reports a state, fall through
+    *)   fail "Cond1.Get failed: $result" ;;
+esac
+
+say "Cond1.Set fires Cond1.ConditionChanged and Get reflects the change"
+rm -f /tmp/dbus-cond.out
+( texec "$CLIENT" monitor-signal "$BUS" \
+    "type='signal',interface='org.finit.Cond1',member='ConditionChanged'" \
+    5000 > /tmp/dbus-cond.out 2>&1 ) &
+cond_mon_pid=$!
+sleep 0.5
+texec "$CLIENT" call-s "$BUS" /org/finit/cond \
+    org.finit.Cond1 Set "dbus-test-cond" >/dev/null \
+    || fail "Cond1.Set returned non-zero"
+set +e
+wait "$cond_mon_pid"
+cond_mon_rc=$?
+set -e
+assert "Cond1 monitor saw a signal (rc=$cond_mon_rc)" "$cond_mon_rc" -eq 0
+case "$(cat /tmp/dbus-cond.out)" in
+    *"SIGNAL org.finit.Cond1 ConditionChanged"*"usr/dbus-test-cond"*on*)
+        assert "ConditionChanged carries usr/dbus-test-cond and 'on'" 0 -eq 0 ;;
+    *)
+        fail "Unexpected Cond1 signal: $(cat /tmp/dbus-cond.out)" ;;
+esac
+
+say "Cond1.Set/Clear on non-usr/* is rejected"
+set +e
+texec "$CLIENT" call-s "$BUS" /org/finit/cond \
+    org.finit.Cond1 Set "pid/sshd" >/tmp/dbus-condrej.out 2>&1
+condrej_rc=$?
+set -e
+assert "pid/* rejected (rc=$condrej_rc)" "$condrej_rc" -eq 1
+case "$(cat /tmp/dbus-condrej.out)" in
+    *InvalidArgs*) assert "Error is InvalidArgs" 0 -eq 0 ;;
+    *) fail "Unexpected reply: $(cat /tmp/dbus-condrej.out)" ;;
+esac
+
+say "Cond1.Set from non-root is rejected with AccessDenied"
+set +e
+texec "$CLIENT" call-s-as-uid 1 "$BUS" /org/finit/cond \
+    org.finit.Cond1 Set "would-be-cond" >/tmp/dbus-condauthz.out 2>&1
+ca_rc=$?
+set -e
+assert "Non-root Cond1.Set rejected (rc=$ca_rc)" "$ca_rc" -eq 1
+case "$(cat /tmp/dbus-condauthz.out)" in
+    *AccessDenied*) assert "Cond1 authz fires" 0 -eq 0 ;;
+    *) fail "Unexpected reply: $(cat /tmp/dbus-condauthz.out)" ;;
+esac