sysvinit/showconsole-1.08.dif

--- blogd.c
+++ blogd.c	2006-08-10 18:41:55.000000000 +0200
@@ -155,25 +155,60 @@ static void reset_signal(int sig, struct
  * To be able to reconnect to real tty on EIO
  */
 static char * tty;
+static char * second;
 static void reconnect(int fd)
 {
     int newfd = -1;
 
-    if ((newfd = open(tty, O_WRONLY|O_NONBLOCK|O_NOCTTY)) < 0)
-	error("can not open %s: %s\n", tty, strerror(errno));
- 
-    if (newfd != 1)
-	dup2(newfd,  1);
-    if (newfd != 2)
-	dup2(newfd,  2);
-
-    if (fd == 1 || fd == 2)
-	goto out;
-    if (newfd != fd)
-	dup2(newfd, fd);
-out:
-    if (newfd > 2)
-	close(newfd);
+    switch (fd) {
+    case 0:		/* Standard in */
+
+	if (tty == (char*)0)
+	    break;
+
+	if ((newfd = open(tty, O_RDWR|O_NONBLOCK|O_NOCTTY)) < 0)
+	    error("can not open %s: %s\n", tty, strerror(errno));
+
+	if (newfd != 0) {
+	    dup2(newfd, 0);
+	    close(newfd);
+	}
+
+	break;
+
+    case 1:		/* Standard out */
+    case 2:		/* Standard error */
+
+	if (tty == (char*)0)
+	    break;
+
+	if ((newfd = open(tty, O_WRONLY|O_NONBLOCK|O_NOCTTY)) < 0)
+	    error("can not open %s: %s\n", tty, strerror(errno));
+
+	if (newfd != 1)
+	    dup2(newfd,  1);
+	if (newfd != 2)
+	    dup2(newfd,  2);
+	if (newfd > 2)
+	    close(newfd);
+
+	break;
+
+    default:		/* IO of second console */
+
+	if (second == (char*)0)
+	    break;
+
+	if ((newfd = open(second, O_WRONLY|O_NONBLOCK|O_NOCTTY)) < 0)
+	    error("can not open %s: %s\n", second, strerror(errno));
+
+	if (newfd != fd) {
+	    dup2(newfd, fd);
+	    close(newfd);
+	}
+
+	break;
+    }
 }
 
 /*
@@ -181,7 +216,7 @@ out:
  */
 int main(int argc, char *argv[])
 {
-    int fd, flags;
+    int fd, fd2, flags;
     int ptm, pts, cntrtty = 1;
     pid_t pid, ppid = getppid();
     char ptsname[NAME_MAX+1];
@@ -198,7 +233,7 @@ int main(int argc, char *argv[])
     if (argc == 2)
 	tty = argv[1];
     else
-	tty = fetchtty(getpid(), ppid);
+	tty = fetchtty(getpid(), ppid, NULL);
 
     if (!tty || !*tty)
 	error("can not discover real system console tty, boot logging disabled.\n");
@@ -241,6 +276,38 @@ int main(int argc, char *argv[])
     if (!w.ws_col)
 	w.ws_row = 80;
 
+    fd2 = -1;
+    do {
+
+	if ((second = secondtty(tty)) == (char*)0)
+	    break;
+
+	if ((fd2 = open(second, O_WRONLY|O_NONBLOCK|O_NOCTTY)) < 0) {
+	    warn("can not open %s: %s\n", second, strerror(errno));
+	    goto out;
+	}
+
+	if ((flags = fcntl(fd2, F_GETFL)) < 0) {
+	    warn("can not get terminal flags of %s: %s\n", second, strerror(errno));
+	    close(fd2);
+	    fd2 = -1;
+	    goto out;
+	}
+
+	flags &= ~(O_NONBLOCK);
+	flags |=   O_NOCTTY;
+	if (fcntl(fd2, F_SETFL, flags) < 0) {
+	    warn("can not set terminal flags of %s: %s\n", second, strerror(errno));
+	    close(fd2);
+	    fd2 = -1;
+	    goto out;
+	}
+
+    out:
+	free(second);
+	
+    } while (0);
+
     if (openpty(&ptm, &pts, ptsname, &t, &w) < 0)
 	error("can not open pty/tty pair: %s\n", strerror(errno));
 
@@ -268,12 +335,15 @@ int main(int argc, char *argv[])
 	dup2(fd,  1);
 	dup2(fd,  2);
 	close(ptm);
-	close(fd);
+	if (fd > 2)
+	    close(fd);
 	break;
     case -1:
 	close(pts);
 	close(ptm);
 	close(fd);
+	if (fd2 > 0)
+	    close(fd2);
 	error("can not fork to become daemon: %s\n", strerror(errno));
 	break;
     default:
@@ -282,12 +352,13 @@ int main(int argc, char *argv[])
 	close(pts);
 	close(ptm);
 	close(fd);
+	if (fd2 > 0)
+	    close(fd2);
 	fprintf(stdout, "\rBoot logging started on %s(%s) at %.24s\n", tty, name, stt);
 	fflush(stdout);
 	exit(0);
     }
-    free(name);
-    prepareIO(reconnect, pidfile, 0, 1);
+    prepareIO(reconnect, pidfile, 0, 1, fd2);
     while (!signaled)
 	safeIO();
 
@@ -297,6 +368,10 @@ int main(int argc, char *argv[])
     if (!cntrtty)
 	kill(ppid, SIGCONT);
 
+    if (fd2 > 0) {
+	(void)tcflush(fd2, TCOFLUSH);
+	close(fd2);
+    }
     (void)tcflush(1, TCOFLUSH);
     close(1);
     (void)tcflush(2, TCOFLUSH);
--- libconsole.c
+++ libconsole.c	2006-08-10 18:41:23.000000000 +0200
@@ -158,41 +158,52 @@ static void (*vc_reconnect)(int fd) = NU
 static inline void safeout (int fd, const char *ptr, size_t s)
 {
     int saveerr = errno;
-    static int repeated;
+    int repeated = 0;
+    static int eiocount;
 
-    repeated = 0;
     while (s > 0) {
 	ssize_t p = write (fd, ptr, s);
 	if (p < 0) {
-	    if (repeated++ > 1000)
-		error("Repeated error on writing to fd %d: %s\n", fd, STRERR);
-	    if (errno == EPIPE)
+	    if (errno == EPIPE) {
+		warn("error on writing to fd %d: %s\n", fd, STRERR);
 		exit (0);
+	    }
 	    if (errno == EINTR) {
 		errno = 0;
 		continue;
 	    }
 	    if (errno == EAGAIN) {	/* Kernel 2.6 seems todo this very often */
+		int ret;
 		fd_set check;
-		struct timeval two = {2, 0};
 
-		errno = 0;
+		if (repeated++ > 1000)
+		    error("repeated error on writing to fd %d: %s\n", fd, STRERR);
+
 		FD_ZERO (&check);
 		FD_SET (fd, &check);
 
 		/* Avoid high load: wait upto two seconds if system is not ready */
-		select(fd + 1, (fd_set*)0, &check, (fd_set*)0, &two);
 		errno = 0;
+		do {
+		    struct timeval two = {2, 0};
+		    ret = select(fd + 1, (fd_set*)0, &check, (fd_set*)0, &two);
+
+		} while ((ret < 0) && (errno == EINTR));
+
+		if (ret < 0)
+		    error("can not write to fd %d: %s\n", fd, STRERR);
 
+		errno = 0;
 		continue;
 	    }
-	    if (errno == EIO && vc_reconnect) {
+	    if (errno == EIO) {
+		if ((eiocount++ > 10) || !vc_reconnect)
+		    error("can not write to fd %d: %s\n", fd, STRERR);
 		(*vc_reconnect)(fd);
-		vc_reconnect = NULL;
 		errno = 0;
 		continue;
 	    }
-	    error("Can not write to fd %d: %s\n", fd, STRERR);
+	    error("can not write to fd %d: %s\n", fd, STRERR);
 	}
 	repeated = 0;
 	ptr += p;
@@ -267,6 +278,7 @@ out:
  */
 static FILE * flog = NULL;
 static int fdwrite = -1;
+static int fdsec   = -1;
 static int fdread  = -1;
 static int fdfifo  = -1;
 
@@ -714,12 +726,13 @@ static void *action(void *dummy)
 static void (*rw_connect)(void) = NULL;
 static const char *fifo_name = _PATH_BLOG_FIFO;
 
-void prepareIO(void (*rfunc)(int), void (*cfunc)(void), const int in, const int out)
+void prepareIO(void (*rfunc)(int), void (*cfunc)(void), const int in, const int out, const int second)
 {
     vc_reconnect = rfunc;
     rw_connect   = cfunc;
     fdread  = in;
     fdwrite = out;
+    fdsec   = second;
 
     if (fifo_name && fdfifo < 0) {
 	struct stat st;
@@ -729,7 +742,7 @@ void prepareIO(void (*rfunc)(int), void 
 	    (void)mkfifo(fifo_name, 0600);
 	errno = 0;
 	if (!stat(fifo_name, &st) && S_ISFIFO(st.st_mode)) {
-	    if ((fdfifo = open(fifo_name, O_RDWR)) < 0)
+	    if ((fdfifo = open(fifo_name, O_RDWR|O_NOCTTY)) < 0)
 		warn("can not open named fifo %s: %s\n", fifo_name, STRERR);
 	}
     }
@@ -769,12 +782,17 @@ static void more_input (struct timeval *
 	const ssize_t cnt = safein(fdread, (char*)trans, sizeof(trans));
 
 	if (cnt > 0) {
-	     parselog(trans, cnt);		/* Parse and make copy of the input */
+	    parselog(trans, cnt);		/* Parse and make copy of the input */
+
+	    safeout(fdwrite, (char*)trans, cnt);	/* Write copy of input to real tty */
+	    (void)tcdrain(fdwrite);
 
-	     safeout(fdwrite, (char*)trans, cnt);	/* Write copy of input to real tty */
-	     tcdrain(fdwrite);
+	    if (fdsec > 0) {
+		safeout(fdsec, (char*)trans, cnt);	/* Write copy of input to second tty */
+		(void)tcdrain(fdsec);
+	    }
 
-	     flushlog();
+	    flushlog();
 	}
     }
 
@@ -883,6 +901,8 @@ void closeIO(void)
     } else
 	warn("no message logging because /var file system is not accessible\n");
     (void)tcdrain(fdwrite);		/* Hold in sync with console */
+    if (fdsec > 0)
+	(void)tcdrain(fdsec);		/* Hold in sync with second console */
 
     do {
 	/*
@@ -926,6 +946,8 @@ void closeIO(void)
     flog = NULL;
 xout:
     (void)tcdrain(fdwrite);
+    if (fdsec > 0)
+	(void)tcdrain(fdsec);
 
     return;
 }
@@ -941,7 +963,7 @@ static void ctty(pid_t pid, unsigned int
     int fd;
 
     sprintf(fetched, "/proc/%d/stat", (int)pid);
-    if ((fd = open(fetched, O_RDONLY)) < 0)
+    if ((fd = open(fetched, O_RDONLY|O_NOCTTY)) < 0)
 	error("can not open(%s): %s\n", fetched, STRERR);
     cnt = safein(fd, fetched, sizeof(fetched));
     close(fd);
@@ -1034,12 +1056,11 @@ static int checkdev(char ** retname, uns
     int found = 0;
     struct dirent * d;
     struct stat st;
-    char * name = NULL;
     static int deep;
 
     memset(&st, 0, sizeof(struct stat));
     while ((d = readdir(dev))) {
-	name = d->d_name;
+	char * name = d->d_name;
 
 	if (*name == '.')
 	    continue;
@@ -1143,6 +1164,14 @@ static int checkdev(char ** retname, uns
 	}
 
 	found++;
+
+	/*
+	 * Allocate memory to be able to return several
+	 * different buffers for different files names.
+	 */
+	name = strdup(name);
+	if (!name)
+	    error("checkdev(): %s\n", STRERR);
 	*retname = name;
 	break;
     }
@@ -1151,7 +1180,7 @@ static int checkdev(char ** retname, uns
 }
 
 /* main routine to fetch tty */
-char * fetchtty(const pid_t pid, const pid_t ppid)
+char * fetchtty(const pid_t pid, const pid_t ppid, unsigned int *mjmi)
 {
     unsigned int tty = 0, found = 0;
     char * name = NULL;
@@ -1167,14 +1196,15 @@ char * fetchtty(const pid_t pid, const p
 	if (!(name = ttyname(0)) || !strcmp(name, "/dev/console"))
 	    tty = fallback(pid, ppid);
 	else {
-	    strcpy(lnk, name);
-	    free(name);
-	    name = lnk;
+	    name = strdup(name);
+	    if (!name)
+		error("fetchtty(): %s\n", STRERR);
 	    goto out;
 	}
 #ifdef TIOCGDEV
     }
 #endif
+    if (mjmi) *mjmi = tty;
 
     if (!(dev = opendir("/dev")))
 	error("can not opendir(/dev): %s\n", STRERR);
@@ -1186,8 +1216,131 @@ char * fetchtty(const pid_t pid, const p
     if (!name)
 	goto out;
 
-    if (!found)
-	*name = '\0';
+    if (!found) {
+	free(name);
+	name = (char*)0;
+    }
 out:
     return name;
 }
+
+/* Do we have some more system console around? */
+char * secondtty(char * compare)
+{
+    char buf[1024], *ptr, *shcmp, *res = (char*)0;
+    unsigned int tty = 0, found = 0;
+    int fd = -1, len;
+    char * name = (char*)0;
+    DIR * dev;
+
+    if ((fd = open("/proc/cmdline", O_RDONLY|O_NOCTTY)) < 0) {
+	warn("can not open /proc/cmdline\n");
+	goto out;
+    }
+
+    if ((len = read(fd, buf, sizeof(buf) - 1)) < 0) {
+	warn("can not read /proc/cmdline\n");
+	close(fd);
+	goto out;
+    }
+    close(fd);
+
+    if (len == 0)
+	goto out;
+
+    shcmp = compare;
+    if (!strncmp(shcmp, "/dev/", 5))
+	shcmp += 5;
+
+    /*
+     * Check for e.g. /dev/tty[1-9] which is equal to /dev/tty0
+     */
+    if (!strncmp(shcmp, "tty", 3)) {
+	size_t len = strspn(shcmp + 3, "123456789");
+
+	if (strlen(shcmp) == len + 3) {
+	    compare = "/dev/tty0";
+	    shcmp   = "tty0";
+	}
+    }
+
+    ptr = &buf[len];
+    while (ptr >= &buf[0]) {
+	if (*ptr == ',' || *ptr == ' ' || *ptr == '\t' || *ptr == '\r' || *ptr == '\n') {
+	    *ptr-- = 0;
+	    continue;
+	}
+	if (*ptr == 'c' && !strncmp(ptr, "console=", 8)) {
+	    char * console  = ptr + 8;
+
+	    if (!strncmp(console, "/dev/", 5))
+		console += 5;
+
+	    /*
+	     * Compare known console tty with that of the kernel command
+	     * line.  If already known skip this console tty and search
+	     * for the next one.
+	     */
+	    if (strcmp(shcmp, console)) {
+		res = console;		/* New device not identical to tty */
+		break;
+	    }
+	}
+	ptr--;
+    }
+
+    if (!res)
+	goto out;
+
+    if (!(dev = opendir("/dev")))
+	error("can not opendir(/dev): %s\n", STRERR);
+    pushd("/dev");
+
+    /* Open second console e.g. /dev/tty0 */
+    if ((fd = open(res, O_RDWR|O_NONBLOCK|O_NOCTTY)) < 0)
+	goto out;
+
+    /*
+     * We do this because if we would write out the buffered
+     * messages to e.g. /dev/tty0 after this we would (re)read
+     * those and buffer them again which leads to an endless loop.
+     */
+#ifdef TIOCGDEV
+    if (ioctl (fd, TIOCGDEV, &tty) < 0) {
+	if (errno == EINVAL && !getenv("NOTIOCGDEV"))
+	    warn("Warning: the ioctl TIOCGDEV is not known by the kernel\n");
+	close(fd);
+	popd();
+	closedir(dev);
+	goto out;
+    }
+#else
+#   error The ioctl TIOCGDEV is not defined (SuSE TIOCGDEV patch is missed)
+#endif
+    close(fd);
+
+    /* Try to open the real device e.g. /dev/tty1 */
+    found = checkdev(&name, tty, dev);
+
+    popd();
+    closedir(dev);
+
+    if (!name)
+	goto out;
+
+    if (!found) {
+	free(name);
+	name = (char*)0;
+	goto out;
+    }
+
+    if (!strcmp(compare, name)) {
+	free(name);
+	name = (char*)0;
+	goto out;		/* Already in use */
+    }
+
+    return name;
+out:
+    return (char*)0;
+}
--- libconsole.h
+++ libconsole.h	2006-08-10 18:41:28.000000000 +0200
@@ -1,6 +1,7 @@
 extern void pushd(const char * path);
 extern void popd(void);
-extern char * fetchtty(const pid_t pid, const pid_t ppid);
-extern void prepareIO(void (*rfunc)(int), void (*cfunc)(void), const int in, const int out);
+extern char * fetchtty(const pid_t pid, const pid_t ppid, unsigned int *mjmi);
+extern char * secondtty(char * compare);
+extern void prepareIO(void (*rfunc)(int), void (*cfunc)(void), const int in, const int out, const int second);
 extern void safeIO (void);
 extern void closeIO(void);
--- showconsole.8
+++ showconsole.8	2006-08-10 18:55:37.000000000 +0200
@@ -16,6 +16,7 @@ Setconsole \- sets the underlying tty of
 .SH SYNOPSIS
 .\"
 .B showconsole
+.RI [ -n ]
 .PP
 .B setconsole /dev/tty<xy> < /dev/console
 .SH DESCRIPTION
@@ -38,6 +39,15 @@ with
 and exactly one argument, a valid character device
 is given.
 \."
+.SH OPTIONS
+.TP
+.B \-n
+Return the major and minor device numbers instead of
+the device file name.  This can be used to asked the
+kernel for the major and minor device numbers of a not
+existing device file in
+.IR /dev .
+\."
 .SH BUGS
 .B showconsole
 needs a mounted
--- showconsole.c
+++ showconsole.c	2006-08-10 18:51:15.000000000 +0200
@@ -51,7 +51,7 @@ void warn (const char *fmt, ...)
  */
 int main(int argc, char *argv[])
 {
-    char * tty = NULL;
+    char * tty = NULL, numeric = 0;
     myname = basename(*argv);
 
     if (!strcmp(myname, "setconsole")) {
@@ -73,8 +73,30 @@ int main(int argc, char *argv[])
 	close(fdc);
 	goto out;
     }
-    tty = fetchtty(getpid(), getppid());
-    if (tty)
+
+    if (argc == 2) {
+	const char* opt = argv[1];
+	if (opt && *opt++ == '-' && *opt++ == 'n' && *opt == '\0')
+	    numeric++;
+	else
+	    error("Usage: %s [-n]\n", myname);
+    } else if (argc > 2)
+	error("Usage: %s [-n]\n", myname);
+
+    if (numeric) {
+	unsigned int dev = 0;
+	(void)fetchtty(getpid(), getppid(), &dev);
+
+	if (dev)
+	    printf("%u %u\n", major(dev), minor(dev));
+	else {
+	    error("real tty unknown\n");
+	    fprintf(stderr, "real tty unknown\n");
+	}
+	goto out;
+    }
+
+    if ((tty = fetchtty(getpid(), getppid(), NULL)))
 	printf("%s\n", tty);
     else {
 	error("real tty unknown\n");