New client side API to access svc_t entries without shared memory

This change is one of the required intermediate steps to remove the
shared memory store for all svc_t, this in turn to avoid any external
programs manipulating the internal memory of PID 1.

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

src/Makefile.am

@@ -44,7 +44,7 @@ finit_LDADD       += -ldl
 endif
 
 initctl_SOURCES    = initctl.c client.c client.h \
-		     serv.c serv.h svc.c svc.h   \
+		     serv.c serv.h svc.h   \
 		     cond.c cond.h util.c util.h
 initctl_CFLAGS     = -W -Wall -Wextra -Wno-unused-parameter -std=gnu99
 initctl_CFLAGS    += $(lite_CFLAGS)

src/api.c

@@ -21,6 +21,7 @@
  * THE SOFTWARE.
  */
 
+#include <ctype.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <stdio.h>
@@ -87,15 +88,42 @@ static int do_start  (char *buf, size_t len) { return call(service_start,   buf,
 static int do_stop   (char *buf, size_t len) { return call(service_stop,    buf, len); }
 static int do_restart(char *buf, size_t len) { return call(service_restart, buf, len); }
 
-#ifdef INETD_ENABLED
+static char query_buf[368];
-static int do_query_inetd(char *buf, size_t len)
+static int missing(char *job, int id)
+{
+	char buf[20];
+	char idstr[10] = "";
+
+	if (!job)
+		job = "";
+	if (id > 1)
+		snprintf(idstr, sizeof(idstr), ":%d", id);
+
+	snprintf(buf, sizeof(buf), "%s%s ", job, idstr);
+	strlcat(query_buf, buf, sizeof(query_buf));
+
+	return 1;
+}
+
+static int do_query(struct init_request *rq, size_t len)
+{
+	memset(query_buf, 0, sizeof(query_buf));
+	if (svc_parse_jobstr(rq->data, strlen(rq->data) + 1, NULL, missing)) {
+		memcpy(rq->data, query_buf, sizeof(rq->data));
+		return 1;
+	}
+
+	return 0;
+}
+
+static svc_t *do_find(char *buf, size_t len)
 {
 	int id = 1;
-	char *ptr, *input = sanitize(buf, len);
+	char *ptr, *input;
-	svc_t *svc;
 
+	input = sanitize(buf, len);
 	if (!input)
-		return -1;
+		return NULL;
 
 	ptr = strchr(input, ':');
 	if (ptr) {
@@ -103,11 +131,20 @@ static int do_query_inetd(char *buf, size_t len)
 		id = atonum(ptr);
 	}
 
-	svc = svc_find_by_jobid(atonum(input), id);
+	if (isdigit(input[0]))
-	if (!svc || !svc_is_inetd(svc)) {
+		return svc_find_by_jobid(atonum(input), id);
-		_e("Cannot %s svc %s ...", !svc ? "find" : "query, not an inetd", input);
+
+	return svc_find_by_nameid(input, id);
+}
+
+#ifdef INETD_ENABLED
+static int do_query_inetd(char *buf, size_t len)
+{
+	svc_t *svc;
+
+	svc = do_find(buf, len);
+	if (!svc || !svc_is_inetd(svc))
 		return 1;
-	}
 
 	return inetd_filter_str(&svc->inetd, buf, len);
 }
@@ -164,6 +201,22 @@ static int do_handle_emit(char *buf, size_t len)
 	return result;
 }
 
+static void send_svc(int sd, svc_t *svc)
+{
+	svc_t empty;
+	size_t len;
+
+	if (!svc) {
+		empty.pid = -1;
+		svc = &empty;
+	}
+
+	len = write(sd, svc, sizeof(*svc));
+	if (len != sizeof(*svc))
+		_d("Failed sending svc_t to client");
+}
+
+
 /*
  * In contrast to the SysV compat handling in plugins/initctl.c, when
  * `initctl runlevel 0` is issued we default to POWERDOWN the system
@@ -290,6 +343,21 @@ static void api_cb(uev_t *w, void *arg, int events)
 			wdogpid = rq.runlevel;
 			break;
 
+		case INIT_CMD_SVC_ITER:
+			_d("svc iter, first: %d", rq.runlevel);
+			send_svc(sd, svc_iterator(rq.runlevel));
+			goto leave;
+
+		case INIT_CMD_SVC_QUERY:
+			_d("svc query: %s", rq.data);
+			result = do_query(&rq, len);
+			break;
+
+		case INIT_CMD_SVC_FIND:
+			_d("svc find: %s", rq.data);
+			send_svc(sd, do_find(rq.data, sizeof(rq.data)));
+			goto leave;
+
 		default:
 			_d("Unsupported cmd: %d", rq.cmd);
 			break;

src/client.c

@@ -89,6 +89,74 @@ exit:
 	return result;
 }
 
+svc_t *client_svc_iterator(int first)
+{
+	int sd = -1;
+	struct init_request rq = {
+		.magic = INIT_MAGIC,
+		.cmd   = INIT_CMD_SVC_ITER,
+	};
+	static svc_t svc;
+
+	sd = client_connect();
+	if (sd == -1)
+		return NULL;
+
+	if (first)
+		rq.runlevel = 1;
+	else
+		rq.runlevel = 0;
+
+	if (write(sd, &rq, sizeof(rq)) != sizeof(rq))
+		goto error;
+	if (read(sd, &svc, sizeof(svc)) != sizeof(svc))
+		goto error;
+
+	client_disconnect();
+	if (svc.pid < 0)
+		return NULL;
+
+	return &svc;
+error:
+	perror("Failed communicating with finit");
+	client_disconnect();
+	sd = -1;
+
+	return NULL;
+}
+
+svc_t *client_svc_find(char *arg)
+{
+	int sd = -1;
+	struct init_request rq = {
+		.magic = INIT_MAGIC,
+		.cmd   = INIT_CMD_SVC_FIND,
+	};
+	static svc_t svc;
+
+	sd = client_connect();
+	if (sd == -1)
+		return NULL;
+
+	strlcpy(rq.data, arg, sizeof(rq.data));
+	if (write(sd, &rq, sizeof(rq)) != sizeof(rq))
+		goto error;
+	if (read(sd, &svc, sizeof(svc)) != sizeof(svc))
+		goto error;
+
+	client_disconnect();
+	if (svc.pid < 0)
+		return NULL;
+
+	return &svc;
+error:
+	client_disconnect();
+	perror("Failed communicating with finit");
+	sd = -1;
+
+	return NULL;
+}
+
 /**
  * Local Variables:
  *  indent-tabs-mode: t

src/client.h

@@ -25,15 +25,18 @@
 #define FINIT_CLIENT_H_
 
 #include "finit.h"
+#include "svc.h"
 
 typedef struct {
 	char  *cmd;
 	int  (*cb)(char *arg);
 } command_t;
 
-int client_connect    (void);
+int    client_connect      (void);
-int client_disconnect (void);
+int    client_disconnect   (void);
 
-int client_send       (struct init_request *rq, ssize_t len);
+int    client_send         (struct init_request *rq, ssize_t len);
+svc_t *client_svc_iterator (int first);
+svc_t *client_svc_find     (char *arg);
 
 #endif /* FINIT_CLIENT_H_ */

src/finit.h

@@ -78,6 +78,9 @@
 #define INIT_CMD_EMIT           15
 #define INIT_CMD_GET_RUNLEVEL   16
 #define INIT_CMD_WDOG_HELLO     128  /* Watchdog register and hello */
+#define INIT_CMD_SVC_ITER       129
+#define INIT_CMD_SVC_QUERY      130
+#define INIT_CMD_SVC_FIND       131
 #define INIT_CMD_NACK           254
 #define INIT_CMD_ACK            255
 

src/initctl.c

@@ -138,21 +138,6 @@ static int do_svc(int cmd, char *arg)
 static int do_emit   (char *arg) { return do_svc(INIT_CMD_EMIT,        arg); }
 static int do_reload (char *arg) { return do_svc(INIT_CMD_RELOAD,      arg); }
 
-static int missing(char *job, int id)
-{
-	char idstr[10] = "";
-
-	if (!job)
-		job = "";
-	if (id > 1)
-		snprintf(idstr, sizeof(idstr), ":%d", id);
-
-	if (verbose)
-		fprintf(stderr, "No such service %s%s\n", job, idstr);
-
-	return 1;
-}
-
 /*
  * This is a wrapper for do_svc() that adds a simple sanity check of
  * the service(s) provided as argument.  If a service does not exist
@@ -160,8 +145,14 @@ static int missing(char *job, int id)
  */
 static int do_startstop(int cmd, char *arg)
 {
-	/* Include \0 in len, needed by parser */
+	struct init_request rq = {
-	if (svc_parse_jobstr(arg, strlen(arg) + 1, NULL, missing)) {
+		.magic = INIT_MAGIC,
+		.cmd   = INIT_CMD_SVC_QUERY
+	};
+
+	strlcpy(rq.data, arg, sizeof(rq.data));
+	if (client_send(&rq, sizeof(rq))) {
+		fprintf(stderr, "No such job(s) or service(s): %s\n\n", rq.data);
 		fprintf(stderr, "Usage: initctl %s <JOB|NAME>[:ID]\n",
 			cmd == INIT_CMD_START_SVC ? "start" :
 			(cmd == INIT_CMD_STOP_SVC ? "stop"  : "restart"));
@@ -257,7 +248,7 @@ static int do_cond_show(char *arg)
 
 	printheader(NULL, "PID     SERVICE               STATUS  CONDITION (+ ON, ~ FLUX, - OFF)", 0);
 
-	for (svc = svc_iterator(1); svc; svc = svc_iterator(0)) {
+	for (svc = client_svc_iterator(1); svc; svc = client_svc_iterator(0)) {
 		if (!svc->cond[0])
 			continue;
 
@@ -420,23 +411,7 @@ static int show_status(char *arg)
 	runlevel = runlevel_get(NULL);
 
 	if (arg && arg[0]) {
-		int id = 1;
+		svc = client_svc_find(arg);
-		char *ptr, *next;
-
-		ptr = strchr(arg, ':');
-		if (ptr) {
-			*ptr++ = 0;
-			next = strchr(ptr, ' ');
-			if (next)
-				*next = 0;
-			id = atonum(ptr);
-		}
-
-		if (isdigit(arg[0]))
-			svc = svc_find_by_jobid(atonum(arg), id);
-		else
-			svc = svc_find_by_nameid(arg, id);
-
 		if (!svc)
 			return 1;
 
@@ -447,12 +422,12 @@ static int show_status(char *arg)
 	if (!verbose)
 		printheader(NULL, "#      STATUS   PID     RUNLEVELS     SERVICE               DESCRIPTION", 0);
 
-	for (svc = svc_iterator(1); svc; svc = svc_iterator(0)) {
+	for (svc = client_svc_iterator(1); svc; svc = client_svc_iterator(0)) {
 		char jobid[10], args[512] = "", *lvls;
 
-		if (svc_is_unique(svc))
+//		if (svc_is_unique(svc))
-			snprintf(jobid, sizeof(jobid), "%d", svc->job);
+//			snprintf(jobid, sizeof(jobid), "%d", svc->job);
-		else
+//		else
 			snprintf(jobid, sizeof(jobid), "%d:%d", svc->job, svc->id);
 
 		printf("%-5s  %7s  ", jobid, svc_status(svc));