[OpenWrt-Devel] [PATCH v2 procd 3/8] Fix curses applications to work with procd

[Michel Stam]

The problem was caused by procd not opening /dev/tty* (which ever was specified in
/etc/inittab), causing /proc/PID/fd to point to /console instead. /dev/console is a
non-controlling tty (CTTY), and cannot be used as one, which is exactly what curses
applications want. Since this is very likely to cause problems with other programs,
procd now opens /dev/tty? when the ID field of the inittab assigns one.

Signed-off-by: Michel Stam <m.stam at fugro.nl>
---
 inittab.c        | 62 ++++++++++++++++++++++++++++++++++++++++----------------
 utils/askfirst.c | 28 ++-----------------------
 2 files changed, 47 insertions(+), 43 deletions(-)

diff --git a/inittab.c b/inittab.c
index c8540b1..5ddf4f0 100644
--- a/inittab.c
+++ b/inittab.c
@@ -63,10 +63,48 @@ 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);
@@ -110,22 +148,17 @@ 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;
@@ -134,7 +167,6 @@ static void askfirst(struct init_action *a)
 
 static void askconsole(struct init_action *a)
 {
-	struct stat s;
 	char line[256], *tty;
 	int i, r, fd = open("/proc/cmdline", O_RDONLY);
 	regex_t pat_cmdline;
@@ -153,20 +185,16 @@ static void askconsole(struct init_action *a)
 	line[matches[1].rm_eo] = '\0';
 	tty = &line[matches[1].rm_so];
 
-	chdir("/dev");
-	i = stat(tty, &s);
-	chdir("/");
-	if (i) {
+	if (!dev_exist(tty)) {
 		DEBUG(4, "skipping %s\n", tty);
 		goto err_out;
 	}
-	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..e1f757a 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("%s: Failed to execute %s\n", argv[0], argv[1]);
 
 	return -1;
 }
-- 
1.7.12.1
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