From a4b017d91c545fd58eba96f5694d7476680ee103 Mon Sep 17 00:00:00 2001
From: David Gibson <david@gibson.dropbear.id.au>
Date: Thu, 6 Apr 2023 13:28:09 +1000
Subject: [PATCH] nstool: Split some command line parsing and socket setup to
 subcommands

This will make it easier to differentiate the options to those commands
further in future.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
---
 test/nstool.c | 102 +++++++++++++++++++++++++++++++++-----------------
 1 file changed, 68 insertions(+), 34 deletions(-)

diff --git a/test/nstool.c b/test/nstool.c
index 20fcc4c..b736e8f 100644
--- a/test/nstool.c
+++ b/test/nstool.c
@@ -11,6 +11,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <stdbool.h>
 #include <errno.h>
 #include <unistd.h>
 #include <sys/socket.h>
@@ -37,19 +38,55 @@ static void usage(void)
 	    "    terminate.\n");
 }
 
-static void hold(int fd, const struct sockaddr_un *addr)
+static int connect_ctl(const char * sockpath, bool wait)
 {
+	int fd = socket(AF_UNIX, SOCK_STREAM, PF_UNIX);
+	struct sockaddr_un addr = {
+		.sun_family = AF_UNIX,
+	};
 	int rc;
 
-	rc = bind(fd, (struct sockaddr *)addr, sizeof(*addr));
+	if (fd < 0)
+		die("socket(): %s\n", strerror(errno));
+
+	strncpy(addr.sun_path, sockpath, UNIX_PATH_MAX);
+
+	do {
+		rc = connect(fd, (struct sockaddr *)&addr, sizeof(addr));
+		if (rc < 0 &&
+		    (!wait || (errno != ENOENT && errno != ECONNREFUSED)))
+			die("connect() to %s: %s\n", sockpath, strerror(errno));
+	} while (rc < 0);
+
+	return fd;
+}
+
+static void cmd_hold(int argc, char *argv[])
+{
+	int fd = socket(AF_UNIX, SOCK_STREAM, PF_UNIX);
+	struct sockaddr_un addr = {
+		.sun_family = AF_UNIX,
+	};
+	const char *sockpath = argv[1];
+	int rc;
+
+	if (argc != 2)
+		usage();
+
+	if (fd < 0)
+		die("socket(): %s\n", strerror(errno));
+
+	strncpy(addr.sun_path, sockpath, UNIX_PATH_MAX);
+
+	rc = bind(fd, (struct sockaddr *)&addr, sizeof(addr));
 	if (rc < 0)
-		die("bind(): %s\n", strerror(errno));
+		die("bind() to %s: %s\n", sockpath, strerror(errno));
 
 	rc = listen(fd, 0);
 	if (rc < 0)
-		die("listen(): %s\n", strerror(errno));
+		die("listen() on %s: %s\n", sockpath, strerror(errno));
 
-	printf("nstool: local PID=%d  local UID=%u  local GID=%u\n",
+	printf("nstool hold: local PID=%d  local UID=%u  local GID=%u\n",
 	       getpid(), getuid(), getgid());
 	do {
 		int afd = accept(fd, NULL, NULL);
@@ -63,71 +100,68 @@ static void hold(int fd, const struct sockaddr_un *addr)
 			die("read(): %s\n", strerror(errno));
 	} while (rc == 0);
 
-	unlink(addr->sun_path);
+	unlink(sockpath);
 }
 
-static void pid(int fd, const struct sockaddr_un *addr)
+static void cmd_pid(int argc, char *argv[])
 {
-	int rc;
+	const char *sockpath = argv[1];
 	struct ucred peercred;
 	socklen_t optlen = sizeof(peercred);
+	int fd, rc;
 
-	do {
-		rc = connect(fd, (struct sockaddr *)addr, sizeof(*addr));
-		if (rc < 0 && errno != ENOENT && errno != ECONNREFUSED)
-			die("connect(): %s\n", strerror(errno));
-	} while (rc < 0);
+	if (argc != 2)
+		usage();
+
+	fd = connect_ctl(sockpath, true);
 
 	rc = getsockopt(fd, SOL_SOCKET, SO_PEERCRED,
 			&peercred, &optlen);
 	if (rc < 0)
-		die("getsockopet(SO_PEERCRED): %s\n", strerror(errno));
+		die("getsockopet(SO_PEERCRED) %s: %s\n",
+		    sockpath, strerror(errno));
 
 	close(fd);
 
 	printf("%d\n", peercred.pid);
 }
 
-static void stop(int fd, const struct sockaddr_un *addr)
+static void cmd_stop(int argc, char *argv[])
 {
-	int rc;
+	const char *sockpath = argv[1];
+	int fd, rc;
 	char buf = 'Q';
 
-	rc = connect(fd, (struct sockaddr *)addr, sizeof(*addr));
-	if (rc < 0)
-		die("connect(): %s\n", strerror(errno));
+	if (argc != 2)
+		usage();
+
+	fd = connect_ctl(sockpath, false);
 
 	rc = write(fd, &buf, sizeof(buf));
 	if (rc < 0)
-		die("write(): %s\n", strerror(errno));
+		die("write() to %s: %s\n", sockpath, strerror(errno));
 
 	close(fd);
 }
 
 int main(int argc, char *argv[])
 {
+	const char *subcmd = argv[1];
 	int fd;
-	const char *sockname;
-	struct sockaddr_un sockaddr = {
-		.sun_family = AF_UNIX,
-	};
 
-	if (argc != 3)
+	if (argc < 2)
 		usage();
 
-	sockname = argv[2];
-	strncpy(sockaddr.sun_path, sockname, UNIX_PATH_MAX);
-
 	fd = socket(AF_UNIX, SOCK_STREAM, PF_UNIX);
 	if (fd < 0)
 		die("socket(): %s\n", strerror(errno));
 
-	if (strcmp(argv[1], "hold") == 0)
-		hold(fd, &sockaddr);
-	else if (strcmp(argv[1], "pid") == 0)
-		pid(fd, &sockaddr);
-	else if (strcmp(argv[1], "stop") == 0)
-		stop(fd, &sockaddr);
+	if (strcmp(subcmd, "hold") == 0)
+		cmd_hold(argc - 1, argv + 1);
+	else if (strcmp(subcmd, "pid") == 0)
+		cmd_pid(argc - 1, argv + 1);
+	else if (strcmp(subcmd, "stop") == 0)
+		cmd_stop(argc - 1, argv + 1);
 	else
 		usage();