initctl: Add SysV compat support for setenv

- Fix compat INIT_CMD_ defines so Finit clients can talk to SysV init
- Add setenv support, only for INIT_HALT={POWERDOWN,HALT} to runlevel 6

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

finit.h

@@ -39,20 +39,33 @@
 #define LINE_SIZE               1024
 #define BUF_SIZE                4096
 
-/* We reuse the INIT_CMD_ for the new initctl tool, but telinit only
+/*
- * supports changing runlevel and reloading the configuration. */
+ * We extend the INIT_CMD_ range for the new initctl tool, Finit only
+ * support changing runlevel, reloading the configuration and setenv
+ * with the old-style /dev/initctl FIFO.
+ */
 #define INIT_SOCKET             _PATH_VARRUN "finit.sock"
 #define INIT_MAGIC              0x03091969
+
+#define INIT_CMD_START          0
 #define INIT_CMD_RUNLVL         1
-#define INIT_CMD_DEBUG          2    /* Toggle Finit debug */
+#define INIT_CMD_POWERFAIL      2
-#define INIT_CMD_RELOAD         3    /* Reload *.conf in /etc/finit.d/ */
+#define INIT_CMD_POWERFAILNOW   3
-#define INIT_CMD_START_SVC      4
+#define INIT_CMD_POWEROK        4
-#define INIT_CMD_STOP_SVC       5
+#define INIT_CMD_BSD            5
-#define INIT_CMD_RELOAD_SVC     6    /* SIGHUP service */
+#define INIT_CMD_SETENV         6
-#define INIT_CMD_RESTART_SVC    7    /* STOP + START service */
+#define INIT_CMD_UNSETENV       7
-#define INIT_CMD_QUERY_INETD    8
+
-#define INIT_CMD_EMIT           9
+/* Finit extensions over std SysV */
-#define INIT_CMD_GET_RUNLEVEL   10
+#define INIT_CMD_DEBUG          8    /* Toggle Finit debug */
+#define INIT_CMD_RELOAD         9    /* Reload *.conf in /etc/finit.d/ */
+#define INIT_CMD_START_SVC      10
+#define INIT_CMD_STOP_SVC       11
+#define INIT_CMD_RELOAD_SVC     12   /* SIGHUP service */
+#define INIT_CMD_RESTART_SVC    13    /* STOP + START service */
+#define INIT_CMD_QUERY_INETD    14
+#define INIT_CMD_EMIT           15
+#define INIT_CMD_GET_RUNLEVEL   16
 #define INIT_CMD_NACK           254
 #define INIT_CMD_ACK            255
 

plugins/initctl.c

@@ -39,6 +39,14 @@
 #include "../sig.h"
 #include "../service.h"
 
+/*
+ * Old-style SysV shutdown sends a setenv cmd INIT_HALT with "=HALT",
+ * "=POWERDOWN", or "" to cancel shutdown, before requesting change to
+ * runlevel 6 over the /dev/initctl FIFO.
+ */
+shutop_t halt = SHUT_DEFAULT;
+
+
 static void parse(void *arg, int fd, int events);
 
 static plugin_t plugin = {
@@ -58,7 +66,36 @@ static void fifo_open(void)
 	}
 }
 
-/* Standard reboot/shutdown utilities talk to init using /dev/initctl.
+/*
+ * We only handle INIT_HALT for differentiating between halt/poweroff
+ */
+static void set_env(char *data)
+{
+	const char *var = "INIT_HALT";
+
+	if (strncmp(data, var, strlen(var)))
+		return;
+	data += strlen(var);
+
+	/*
+	 * No value means unset env, in this case cancel shutdown.
+	 */
+	if (data[0] == 0) {
+		halt = SHUT_DEFAULT;
+		/* XXX: Cancel timer here, when we get support for timed shutdown */
+		return;
+	}
+
+	if (string_match(data, "=POWERDOWN"))
+		halt = SHUT_OFF;
+	if (string_match(data, "=HALT"))
+		halt = SHUT_HALT;
+
+	/* Now we wait for runlevel change, or cancelled shutdown */
+}
+
+/*
+ * Standard reboot/shutdown utilities talk to init using /dev/initctl.
  * We should check if the fifo was recreated and reopen it.
  */
 static void parse(void *UNUSED(arg), int fd, int UNUSED(events))
@@ -92,8 +129,8 @@ static void parse(void *UNUSED(arg), int fd, int UNUSED(events))
 		case INIT_CMD_RUNLVL:
 			switch (rq.runlevel) {
 			case '0':
-				_d("Halting system (SIGUSR2)");
+				_d("Halting system (SIGUSR1 or SIGUSR2)");
-				do_shutdown(SIGUSR2);
+				do_shutdown(halt);
 				break;
 
 			case 's':
@@ -109,8 +146,8 @@ static void parse(void *UNUSED(arg), int fd, int UNUSED(events))
 				break;
 
 			case '6':
-				_d("Rebooting system (SIGUSR1)");
+				_d("Rebooting system (SIGTERM)");
-				do_shutdown(SIGUSR1);
+				do_shutdown(SHUT_REBOOT);
 				break;
 
 			default:
@@ -123,6 +160,10 @@ static void parse(void *UNUSED(arg), int fd, int UNUSED(events))
 			service_reload_dynamic();
 			break;
 
+		case INIT_CMD_SETENV:
+			set_env(rq.data);
+			break;
+
 		default:
 			_d("Unsupported cmd: %d", rq.cmd);
 			break;

sig.h

@@ -55,6 +55,11 @@
                 sigaction(sig, &sa, NULL);      \
         } while (0)
 
+/*
+ * For old-style /dev/initctl shutdown we default to halt
+ */
+#define SHUT_DEFAULT SHUT_HALT
+
 typedef enum {
 	SHUT_OFF,
 	SHUT_HALT,