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-bus.sh

@@ -0,0 +1,62 @@
+#!/bin/sh
+# libink: org.freedesktop.DBus built-in interface.
+#
+# Covers the stock D-Bus interface every conforming bus implements:
+# Hello (peer name allocation), Introspect (XML), and AddMatch's
+# error-path rule parser.
+
+set -eu
+
+TEST_DIR=$(dirname "$0")
+
+# shellcheck source=/dev/null
+. "$TEST_DIR/lib/setup.sh"
+# shellcheck source=/dev/null
+. "$TEST_DIR/lib/dbus-setup.sh"
+
+say "Hello() returns a unique name beginning with ':1.'"
+name=$(texec "$CLIENT" hello "$BUS")
+case "$name" in
+    :1.*) assert "Hello returned a :1.N name (got $name)" 0 -eq 0 ;;
+    *)    fail "Hello returned unexpected name: $name" ;;
+esac
+
+say "Two Hello() calls produce different unique names"
+n1=$(texec "$CLIENT" hello "$BUS")
+n2=$(texec "$CLIENT" hello "$BUS")
+assert "Unique names increment ($n1 vs $n2)" "$n1" != "$n2"
+
+say "Introspect on root path returns valid XML"
+xml=$(texec "$CLIENT" introspect "$BUS" /)
+case "$xml" in
+    *'<node'*) assert "XML has <node> root (good)" 0 -eq 0 ;;
+    *) fail "Root introspect missing <node>: $xml" ;;
+esac
+
+say "Introspect on /org/finit/manager exposes Manager1.ListServices"
+xml=$(texec "$CLIENT" introspect "$BUS" /org/finit/manager)
+case "$xml" in
+    *'org.finit.Manager1'*'ListServices'*)
+        assert "Manager1 and ListServices visible in XML" 0 -eq 0 ;;
+    *)
+        fail "Manager1 XML missing; got: $xml" ;;
+esac
+
+say "AddMatch with a bogus key is rejected"
+set +e
+texec "$CLIENT" call-s "$BUS" /org/freedesktop/DBus \
+    org.freedesktop.DBus AddMatch "bogus='whatever'" >/tmp/dbus-match.out 2>&1
+am_rc=$?
+set -e
+assert "Bad rule rejected (rc=$am_rc)" "$am_rc" -eq 1
+case "$(cat /tmp/dbus-match.out)" in
+    *MatchRuleInvalid*) assert "Error is MatchRuleInvalid" 0 -eq 0 ;;
+    *) fail "Unexpected reply: $(cat /tmp/dbus-match.out)" ;;
+esac
+
+say "Unknown method on a Finit interface gets an org.freedesktop.DBus.Error.* reply"
+set +e
+texec "$CLIENT" unknown "$BUS"
+unknown_rc=$?
+set -e
+assert "Unknown method returned an error (rc=$unknown_rc)" "$unknown_rc" -eq 0