From: Michel Stam <m.stam@fugro.nl>
Date: Tue, 4 Nov 2014 15:50:54 +0000 (+0100)
Subject: Honour tty field in /etc/inittab
X-Git-Url: https://git.archive.openwrt.org/?p=project%2Fprocd.git;a=commitdiff_plain;h=44803f0b48e6b0bbc56b1f9f8c2ea9c8e1003302

Honour tty field in /etc/inittab

The problem was caused by procd not opening /dev/tty* (whichever was
specified for the ID field /etc/inittab), causing /proc/PID/fd to
point to /dev/console instead.

This is a rework of e63051d9, which did not initialise the console
pointer and did not check the tty pointer in askconsole. askfirst
was not completely fixed as it expected the console parameter on
the commandline, which is no longer necessary because procd opens
the console prior to fork()-ing.

Signed-off-by: Michel Stam <m.stam@fugro.nl>
---

diff --git a/inittab.c b/inittab.c
index 2d9a1e0..d7bb35b 100644
--- a/inittab.c
+++ b/inittab.c
@@ -37,7 +37,7 @@
 #define MAX_ARGS	8
 
 struct init_action;
-const char *console;
+char *console = NULL;
 
 struct init_handler {
 	const char *name;
@@ -64,10 +64,48 @@ static char *ask = "/sbin/askfirst";
 
 static LIST_HEAD(actions);
 
+static int dev_open(const char *dev)
+{
+	int fd = -1;
+
+	if (dev) {
+		chdir("/dev");
+		fd = open( dev, O_RDWR);
+		chdir("/");
+	}
+
+	return fd;
+}
+
+static int dev_exist(const char *dev)
+{
+	int res;
+
+	res = dev_open(dev);
+	if (res != -1) {
+		close(res);
+	}
+
+	return (res != -1);
+}
+
 static void fork_worker(struct init_action *a)
 {
+	int fd;
+	pid_t p;
+
 	a->proc.pid = fork();
 	if (!a->proc.pid) {
+		p = setsid( );
+		fd = dev_open(a->id);
+		if (fd != -1)
+		{
+			dup2(fd, STDIN_FILENO);
+			dup2(fd, STDOUT_FILENO);
+			dup2(fd, STDERR_FILENO);
+			tcsetpgrp(fd, p);
+			close(fd);
+		}
 		execvp(a->argv[0], a->argv);
 		ERROR("Failed to execute %s\n", a->argv[0]);
 		exit(-1);
@@ -111,22 +149,17 @@ static void runrc(struct init_action *a)
 
 static void askfirst(struct init_action *a)
 {
-	struct stat s;
 	int i;
 
-	chdir("/dev");
-	i = stat(a->id, &s);
-	chdir("/");
-	if (i || (console && !strcmp(console, a->id))) {
+	if (!dev_exist(a->id) || (console && !strcmp(console, a->id))) {
 		DEBUG(4, "Skipping %s\n", a->id);
 		return;
 	}
 
 	a->tout.cb = respawn;
-	for (i = MAX_ARGS - 2; i >= 2; i--)
-		a->argv[i] = a->argv[i - 2];
+	for (i = MAX_ARGS - 1; i >= 1; i--)
+		a->argv[i] = a->argv[i - 1];
 	a->argv[0] = ask;
-	a->argv[1] = a->id;
 	a->respawn = 500;
 
 	a->proc.cb = child_exit;
@@ -135,29 +168,27 @@ static void askfirst(struct init_action *a)
 
 static void askconsole(struct init_action *a)
 {
-	struct stat s;
 	char line[256], *tty, *split;
 	int i;
 
 	tty = get_cmdline_val("console", line, sizeof(line));
-	split=strchr(tty, ',');
-	if (split != NULL)
-		split = '\0';
-	
-	chdir("/dev");
-	i = stat(tty, &s);
-	chdir("/");
-	if (i) {
+	if (tty != NULL) {
+		split = strchr(tty, ',');
+		if (split != NULL)
+			*split = '\0';
+	}
+
+	if (!dev_exist(tty)) {
 		DEBUG(4, "skipping %s\n", tty);
 		return;
 	}
 	console = strdup(tty);
 
 	a->tout.cb = respawn;
-	for (i = MAX_ARGS - 2; i >= 2; i--)
-		a->argv[i] = a->argv[i - 2];
+	for (i = MAX_ARGS - 1; i >= 1; i--)
+		a->argv[i] = a->argv[i - 1];
+	a->id = strdup(tty);
 	a->argv[0] = ask;
-	a->argv[1] = strdup(tty);
 	a->respawn = 500;
 
 	a->proc.cb = child_exit;
diff --git a/utils/askfirst.c b/utils/askfirst.c
index 6ad77aa..e78823c 100644
--- a/utils/askfirst.c
+++ b/utils/askfirst.c
@@ -19,34 +19,10 @@
 #include <unistd.h>
 #include <fcntl.h>
 
-static int redirect_output(const char *dev)
-{
-	pid_t p = setsid();
-	int fd;
-
-	chdir("/dev");
-	fd = open(dev, O_RDWR);
-	chdir("/");
-
-	if (fd < 0)
-		return -1;
-
-	dup2(fd, STDIN_FILENO);
-	dup2(fd, STDOUT_FILENO);
-	dup2(fd, STDERR_FILENO);
-	tcsetpgrp(fd, p);
-	close(fd);
-
-	return 0;
-}
-
 int main(int argc, char **argv)
 {
 	int c;
 
-	if (redirect_output(argv[1]))
-		fprintf(stderr, "%s: Failed to open %s\n", argv[0], argv[1]);
-
 	printf("Please press Enter to activate this console.\n");
 	do {
 		c = getchar();
@@ -55,8 +31,8 @@ int main(int argc, char **argv)
 	}
 	while (c != 0xA);
 
-	execvp(argv[2], &argv[2]);
-	printf("%s: Failed to execute %s\n", argv[0], argv[2]);
+	execvp(argv[1], &argv[1]);
+	printf("Failed to execute %s\n", argv[0]);
 
 	return -1;
 }