Re: [PATCH] sulogin: ignore not existing console devices

["Dr. Werner Fink" <werner@suse.de>]

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On 2021/05/17 16:58:25 +0200, Dr. Werner Fink wrote:
> On 2021/05/10 16:51:11 +0200, Karel Zak wrote:
> > On Thu, May 06, 2021 at 12:54:12PM +0200, Werner Fink wrote:
> > >  login-utils/sulogin-consoles.h |  1 +
> > >  login-utils/sulogin.c          | 97 +++++++++++++++++++++++++++++++++++-------
> > >  2 files changed, 82 insertions(+), 16 deletions(-)
> > 
> > Seems good, but git does not like the patch from your e-mail:
> > 
> >         Applying: sulogin: ignore not existing console devices
> >         .git/rebase-apply/patch:49: space before tab in indent.
> >                     con->flags |= CON_SERIAL;
> >         error: patch failed: login-utils/sulogin.c:775
> >         error: login-utils/sulogin.c: patch does not apply
> >         Patch failed at 0001 sulogin: ignore not existing console devices
> 
> Thanks for spotting! ... looks like I've missed the a/b prefixes
> 
> Werner

The attached patch is for latest git repository

Werner

-- 
  "Having a smoking section in a restaurant is like having
          a peeing section in a swimming pool." -- Edward Burr

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From 38a9f563577e0ff73bfeed2d011d211d1486180f Mon Sep 17 00:00:00 2001
From: Werner Fink <werner@suse.de>
Date: Mon, 17 May 2021 17:20:32 +0200
Subject: [PATCH] sulogin: ignore none-existing console devices

and also none-functional console devices. Redirect the error
messages to the appropiate console device.

Signed-off-by: Werner Fink <werner@suse.de>
---
 login-utils/sulogin-consoles.h |  1 +
 login-utils/sulogin.c          | 95 ++++++++++++++++++++++++++++------
 2 files changed, 81 insertions(+), 15 deletions(-)

diff --git login-utils/sulogin-consoles.h login-utils/sulogin-consoles.h
index 0bfbc3871..12032c997 100644
--- a/login-utils/sulogin-consoles.h
+++ b/login-utils/sulogin-consoles.h
@@ -40,6 +40,7 @@ struct console {
 	int fd, id;
 #define	CON_SERIAL	0x0001
 #define	CON_NOTTY	0x0002
+#define	CON_EIO		0x0004
 	pid_t pid;
 	struct chardata cp;
 	struct termios tio;
diff --git login-utils/sulogin.c login-utils/sulogin.c
index 6ed63f1a0..8b4e2d108 100644
--- a/login-utils/sulogin.c
+++ b/login-utils/sulogin.c
@@ -52,6 +52,7 @@
 #ifdef __linux__
 # include <sys/kd.h>
 # include <sys/param.h>
+# include <linux/serial.h>
 #endif
 
 #include "c.h"
@@ -104,6 +105,9 @@ static void tcinit(struct console *con)
 	int flags = 0, mode = 0;
 	struct termios *tio = &con->tio;
 	const int fd = con->fd;
+#if defined(TIOCGSERIAL)
+	struct serial_struct serinfo;
+#endif
 #ifdef USE_PLYMOUTH_SUPPORT
 	struct termios lock;
 	int i = (plymouth_command(MAGIC_PING)) ? PLYMOUTH_TERMIOS_FLAGS_DELAY : 0;
@@ -123,27 +127,72 @@ static void tcinit(struct console *con)
 	}
 	memset(&lock, 0, sizeof(struct termios));
 	ioctl(fd, TIOCSLCKTRMIOS, &lock);
+	errno = 0;
 #endif
+
+#if defined(TIOCGSERIAL)
+	if (ioctl(fd, TIOCGSERIAL,  &serinfo) >= 0)
+	    	con->flags |= CON_SERIAL;
+	errno = 0;
+#else
+# if defined(KDGKBMODE)
+	if (ioctl(fd, KDGKBMODE, &mode) < 0)
+		con->flags |= CON_SERIAL;
 	errno = 0;
+# endif
+#endif
 
 	if (tcgetattr(fd, tio) < 0) {
-		warn(_("tcgetattr failed"));
-		con->flags |= CON_NOTTY;
-		return;
+		int saveno = errno;
+#if defined(KDGKBMODE) || defined(TIOCGSERIAL)
+		if (con->flags & CON_SERIAL) {			/* Try to recover this */
+
+# if defined(TIOCGSERIAL)
+			serinfo.flags |= ASYNC_SKIP_TEST;	/* Skip test of UART */
+
+			if (ioctl(fd, TIOCSSERIAL, &serinfo) < 0)
+				goto tcgeterr;
+			if (ioctl(fd, TIOCSERCONFIG) < 0)	/* Try to autoconfigure */
+				goto tcgeterr;
+			if (ioctl(fd, TIOCGSERIAL,  &serinfo) < 0)
+				goto tcgeterr;			/* Ouch */
+# endif
+			if (tcgetattr(fd, tio) < 0)		/* Retry to get tty attributes */
+				saveno = errno;
+		}
+# if defined(TIOCGSERIAL)
+	tcgeterr:
+# endif
+		if (saveno)
+#endif
+		{
+			FILE *fcerr = fdopen(fd, "w");
+			if (fcerr) {
+				fprintf(fcerr, _("tcgetattr failed"));
+				fclose(fcerr);
+			}
+			warn(_("tcgetattr failed"));
+
+			con->flags &= ~CON_SERIAL;
+			if (saveno != EIO)
+				con->flags |= CON_NOTTY;
+			else
+				con->flags |= CON_EIO;
+
+			errno = 0;
+			return;
+		}
 	}
 
 	/* Handle lines other than virtual consoles here */
-#if defined(KDGKBMODE)
-	if (ioctl(fd, KDGKBMODE, &mode) < 0)
+#if defined(KDGKBMODE) || defined(TIOCGSERIAL)
+	if (con->flags & CON_SERIAL)
 #endif
 	{
 		speed_t ispeed, ospeed;
 		struct winsize ws;
 		errno = 0;
 
-		/* this is a modem line */
-		con->flags |= CON_SERIAL;
-
 		/* Flush input and output queues on modem lines */
 		tcflush(fd, TCIOFLUSH);
 
@@ -220,6 +269,8 @@ static void tcfinal(struct console *con)
 	struct termios *tio = &con->tio;
 	const int fd = con->fd;
 
+	if (con->flags & CON_EIO)
+		return;
 	if ((con->flags & CON_SERIAL) == 0) {
 		xsetenv("TERM", "linux", 1);
 		return;
@@ -557,12 +608,16 @@ err:
 static void setup(struct console *con)
 {
 	int fd = con->fd;
-	const pid_t pid = getpid(), pgrp = getpgid(0), ppgrp =
-	    getpgid(getppid()), ttypgrp = tcgetpgrp(fd);
+	const pid_t pid = getpid(), pgrp = getpgid(0), ppgrp = getpgid(getppid());
+	pid_t ttypgrp;
 
 	if (con->flags & CON_NOTTY)
+		goto notty;
+	if (con->flags & CON_EIO)
 		return;
 
+	ttypgrp = tcgetpgrp(fd);
+
 	/*
 	 * Only go through this trouble if the new
 	 * tty doesn't fall in this process group.
@@ -585,6 +640,7 @@ static void setup(struct console *con)
 		ioctl(fd, TIOCSCTTY, (char *)1);
 		tcsetpgrp(fd, ppgrp);
 	}
+notty:
 	dup2(fd, STDIN_FILENO);
 	dup2(fd, STDOUT_FILENO);
 	dup2(fd, STDERR_FILENO);
@@ -608,20 +664,25 @@ static const char *getpasswd(struct console *con)
 	struct termios tty;
 	static char pass[128], *ptr;
 	struct chardata *cp;
-	const char *ret = pass;
+	const char *ret = NULL;
 	unsigned char tc;
 	char c, ascval;
 	int eightbit;
 	const int fd = con->fd;
 
-	if (con->flags & CON_NOTTY)
+	if (con->flags & CON_EIO)
 		goto out;
+
 	cp = &con->cp;
 	tty = con->tio;
+	tc = 0;
+	ret = pass;
 
 	tty.c_iflag &= ~(IUCLC|IXON|IXOFF|IXANY);
 	tty.c_lflag &= ~(ECHO|ECHOE|ECHOK|ECHONL|TOSTOP|ISIG);
-	tc = (tcsetattr(fd, TCSAFLUSH, &tty) == 0);
+
+	if ((con->flags & CON_NOTTY) == 0)
+		tc = (tcsetattr(fd, TCSAFLUSH, &tty) == 0);
 
 	sigemptyset(&sa.sa_mask);
 	sa.sa_handler = alrm_handler;
@@ -647,11 +708,12 @@ static const char *getpasswd(struct console *con)
 			}
 			ret = NULL;
 			switch (errno) {
-			case 0:
 			case EIO:
+				con->flags |= CON_EIO;
 			case ESRCH:
 			case EINVAL:
 			case ENOENT:
+			case 0:
 				break;
 			default:
 				warn(_("cannot read %s"), con->tty);
@@ -969,10 +1031,13 @@ int main(int argc, char **argv)
 		con = list_entry(ptr, struct console, entry);
 		if (con->id >= CONMAX)
 			break;
+		if (con->flags & CON_EIO)
+			goto next;
 
 		switch ((con->pid = fork())) {
 		case 0:
 			mask_signal(SIGCHLD, SIG_DFL, NULL);
+			dup2(con->fd, STDERR_FILENO);
 		nofork:
 			setup(con);
 			while (1) {
@@ -1027,7 +1092,7 @@ int main(int argc, char **argv)
 		default:
 			break;
 		}
-
+	next:
 		ptr = ptr->next;
 
 	} while (ptr != &consoles);
-- 
2.28.0


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