patch action. Fixed typos in source code, comments, manual pages, and changelog. Corrections provided by Jens Schleusener of FOSSIES (fossies.org).
511 lines
10 KiB
C
511 lines
10 KiB
C
/*
|
|
* consoles.c Routines to detect the system consoles
|
|
*
|
|
* Copyright (c) 2011 SuSE LINUX Products GmbH, All rights reserved.
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation; either version 2, or (at your option)
|
|
* any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program (see the file COPYING); if not, write to the
|
|
* Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
|
|
* MA 02110-1301, USA.
|
|
*
|
|
* Author: Werner Fink <werner@suse.de>
|
|
*/
|
|
|
|
#include <limits.h>
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
#include <sys/types.h>
|
|
#include <sys/stat.h>
|
|
#include <sys/ioctl.h>
|
|
#include <sys/ttydefaults.h>
|
|
#ifdef __linux__
|
|
# include <sys/vt.h>
|
|
# include <sys/kd.h>
|
|
# include <linux/serial.h>
|
|
#include <sys/sysmacros.h>
|
|
#endif
|
|
#include <fcntl.h>
|
|
#include <dirent.h>
|
|
#include <unistd.h>
|
|
#include "consoles.h"
|
|
|
|
#ifdef __linux__
|
|
# include <linux/major.h>
|
|
#endif
|
|
|
|
#if !defined(__STDC_VERSION__) || (__STDC_VERSION__ < 199901L)
|
|
# ifndef typeof
|
|
# define typeof __typeof__
|
|
# endif
|
|
# ifndef restrict
|
|
# define restrict __restrict__
|
|
# endif
|
|
#endif
|
|
|
|
#define alignof(type) ((sizeof(type)+(sizeof(void*)-1)) & ~(sizeof(void*)-1))
|
|
|
|
struct console *consoles;
|
|
|
|
/*
|
|
* Read and allocate one line from file,
|
|
* the caller has to free the result
|
|
*/
|
|
static
|
|
#ifdef __GNUC__
|
|
__attribute__((__nonnull__))
|
|
#endif
|
|
char *oneline(const char *file)
|
|
{
|
|
FILE *fp;
|
|
char *ret = (char*)0, *nl;
|
|
size_t len = 0;
|
|
|
|
if ((fp = fopen(file, "re")) == (FILE*)0)
|
|
goto err;
|
|
if (getline(&ret, &len, fp) < 0)
|
|
goto out;
|
|
if (len)
|
|
ret[len-1] = '\0';
|
|
if ((nl = strchr(ret, '\n')))
|
|
*nl = '\0';
|
|
out:
|
|
fclose(fp);
|
|
err:
|
|
return ret;
|
|
}
|
|
|
|
#ifdef __linux__
|
|
/*
|
|
* Read and determine active attribute for tty below
|
|
* /sys/class/tty, the caller has to free the result.
|
|
*/
|
|
static
|
|
__attribute__((__malloc__))
|
|
char *actattr(const char *tty)
|
|
{
|
|
char *ret = (char*)0;
|
|
char *path;
|
|
|
|
if (!tty || *tty == '\0')
|
|
goto err;
|
|
|
|
if (asprintf(&path, "/sys/class/tty/%s/active", tty) < 0)
|
|
goto err;
|
|
|
|
if ((ret = oneline(path)) == (char*)0)
|
|
goto out;
|
|
out:
|
|
free(path);
|
|
err:
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Read and determine device attribute for tty below
|
|
* /sys/class/tty.
|
|
*/
|
|
static
|
|
dev_t devattr(const char *tty)
|
|
{
|
|
unsigned int maj, min;
|
|
dev_t dev = 0;
|
|
char *path, *value;
|
|
|
|
if (!tty || *tty == '\0')
|
|
goto err;
|
|
|
|
if (asprintf(&path, "/sys/class/tty/%s/dev", tty) < 0)
|
|
goto err;
|
|
|
|
if ((value = oneline(path)) == (char*)0)
|
|
goto out;
|
|
|
|
if (sscanf(value, "%u:%u", &maj, &min) == 2)
|
|
dev = makedev(maj, min);
|
|
free(value);
|
|
out:
|
|
free(path);
|
|
err:
|
|
return dev;
|
|
}
|
|
#endif /* __linux__ */
|
|
|
|
/*
|
|
* Search below /dev for the character device in
|
|
* the local `dev_t comparedev' variable.
|
|
*/
|
|
static dev_t comparedev;
|
|
static
|
|
#ifdef __GNUC__
|
|
__attribute__((__nonnull__,__malloc__,__hot__))
|
|
#endif
|
|
char* scandev(DIR *dir)
|
|
{
|
|
char *name = (char*)0;
|
|
struct dirent *dent;
|
|
int fd;
|
|
|
|
fd = dirfd(dir);
|
|
rewinddir(dir);
|
|
while ((dent = readdir(dir))) {
|
|
char *path;
|
|
struct stat st;
|
|
if (fstatat(fd, dent->d_name, &st, 0) < 0)
|
|
continue;
|
|
if (!S_ISCHR(st.st_mode))
|
|
continue;
|
|
if (comparedev != st.st_rdev)
|
|
continue;
|
|
if (asprintf(&path, "/dev/%s", dent->d_name) < 0)
|
|
continue;
|
|
name = realpath(path, NULL);
|
|
free(path);
|
|
break;
|
|
}
|
|
return name;
|
|
}
|
|
|
|
/*
|
|
* Default control characters for an unknown terminal line.
|
|
*/
|
|
static
|
|
struct chardata initcp = {
|
|
CERASE,
|
|
CKILL,
|
|
CTRL('r'),
|
|
0
|
|
};
|
|
|
|
/*
|
|
* Allocate an aligned `struct console' memory area,
|
|
* initialize its default values, and append it to
|
|
* the global linked list.
|
|
*/
|
|
|
|
static int concount; /* Counter for console IDs */
|
|
|
|
static
|
|
#ifdef __GNUC__
|
|
__attribute__((__nonnull__,__hot__))
|
|
#endif
|
|
void consalloc(char * name)
|
|
{
|
|
struct console *restrict tail;
|
|
|
|
if (posix_memalign((void*)&tail, sizeof(void*), alignof(typeof(struct console))) != 0)
|
|
perror("memory allocation");
|
|
|
|
tail->next = (struct console*)0;
|
|
tail->tty = name;
|
|
|
|
tail->file = (FILE*)0;
|
|
tail->flags = 0;
|
|
tail->fd = -1;
|
|
tail->id = concount++;
|
|
tail->pid = 0;
|
|
memset(&tail->tio, 0, sizeof(tail->tio));
|
|
memcpy(&tail->cp, &initcp, sizeof(struct chardata));
|
|
|
|
if (!consoles)
|
|
consoles = tail;
|
|
else
|
|
consoles->next = tail;
|
|
}
|
|
|
|
/*
|
|
* Try to detect the real device(s) used for the system console
|
|
* /dev/console if but only if /dev/console is used. On Linux
|
|
* this can be more than one device, e.g. a serial line as well
|
|
* as a virtual console as well as a simple printer.
|
|
*
|
|
* Returns 1 if stdout and stderr should be reconnected and 0
|
|
* otherwise.
|
|
*/
|
|
int detect_consoles(const char *device, int fallback)
|
|
{
|
|
int fd, ret = 0;
|
|
#ifdef __linux__
|
|
char *attrib, *cmdline;
|
|
FILE *fc;
|
|
#endif
|
|
if (!device || *device == '\0')
|
|
fd = dup(fallback);
|
|
else {
|
|
fd = open(device, O_RDWR|O_NONBLOCK|O_NOCTTY|O_CLOEXEC);
|
|
ret = 1;
|
|
}
|
|
|
|
if (fd >= 0) {
|
|
DIR *dir;
|
|
char *name;
|
|
struct stat st;
|
|
#ifdef TIOCGDEV
|
|
unsigned int devnum;
|
|
#endif
|
|
|
|
if (fstat(fd, &st) < 0) {
|
|
close(fd);
|
|
goto fallback;
|
|
}
|
|
comparedev = st.st_rdev;
|
|
|
|
if (ret && (fstat(fallback, &st) < 0 || comparedev != st.st_rdev))
|
|
dup2(fd, fallback);
|
|
#ifdef __linux__
|
|
/*
|
|
* Check if the device detection for Linux system console should be used.
|
|
*/
|
|
if (comparedev == makedev(TTYAUX_MAJOR, 0)) { /* /dev/tty */
|
|
close(fd);
|
|
device = "/dev/tty";
|
|
goto fallback;
|
|
}
|
|
if (comparedev == makedev(TTYAUX_MAJOR, 1)) { /* /dev/console */
|
|
close(fd);
|
|
goto console;
|
|
}
|
|
if (comparedev == makedev(TTYAUX_MAJOR, 2)) { /* /dev/ptmx */
|
|
close(fd);
|
|
device = "/dev/tty";
|
|
goto fallback;
|
|
}
|
|
if (comparedev == makedev(TTY_MAJOR, 0)) { /* /dev/tty0 */
|
|
struct vt_stat vt;
|
|
if (ioctl(fd, VT_GETSTATE, &vt) < 0) {
|
|
close(fd);
|
|
goto fallback;
|
|
}
|
|
comparedev = makedev(TTY_MAJOR, (int)vt.v_active);
|
|
}
|
|
#endif
|
|
#ifdef TIOCGDEV
|
|
if (ioctl (fd, TIOCGDEV, &devnum) < 0) {
|
|
close(fd);
|
|
goto fallback;
|
|
}
|
|
comparedev = (dev_t)devnum;
|
|
#endif
|
|
close(fd);
|
|
dir = opendir("/dev");
|
|
if (!dir)
|
|
goto fallback;
|
|
name = scandev(dir);
|
|
if (name)
|
|
consalloc(name);
|
|
closedir(dir);
|
|
if (!consoles)
|
|
goto fallback;
|
|
return ret;
|
|
}
|
|
#ifdef __linux__
|
|
console:
|
|
/*
|
|
* Detection of devices used for Linux system consolei using
|
|
* the /proc/consoles API with kernel 2.6.38 and higher.
|
|
*/
|
|
if ((fc = fopen("/proc/consoles", "re"))) {
|
|
char fbuf[16];
|
|
int maj, min;
|
|
DIR *dir;
|
|
dir = opendir("/dev");
|
|
if (!dir) {
|
|
fclose(fc);
|
|
goto fallback;
|
|
}
|
|
while ((fscanf(fc, "%*s %*s (%[^)]) %d:%d", &fbuf[0], &maj, &min) == 3)) {
|
|
char * name;
|
|
|
|
if (!strchr(fbuf, 'E'))
|
|
continue;
|
|
comparedev = makedev(maj, min);
|
|
|
|
name = scandev(dir);
|
|
if (!name)
|
|
continue;
|
|
consalloc(name);
|
|
}
|
|
closedir(dir);
|
|
fclose(fc);
|
|
return ret;
|
|
}
|
|
/*
|
|
* Detection of devices used for Linux system console using
|
|
* the sysfs /sys/class/tty/ API with kernel 2.6.37 and higher.
|
|
*/
|
|
if ((attrib = actattr("console"))) {
|
|
char *words = attrib, *token;
|
|
DIR *dir;
|
|
|
|
dir = opendir("/dev");
|
|
if (!dir) {
|
|
free(attrib);
|
|
goto fallback;
|
|
}
|
|
while ((token = strsep(&words, " \t\r\n"))) {
|
|
char * name;
|
|
|
|
if (*token == '\0')
|
|
continue;
|
|
comparedev = devattr(token);
|
|
if (comparedev == makedev(TTY_MAJOR, 0)) {
|
|
char *tmp = actattr(token);
|
|
if (!tmp)
|
|
continue;
|
|
comparedev = devattr(tmp);
|
|
free(tmp);
|
|
}
|
|
|
|
name = scandev(dir);
|
|
if (!name)
|
|
continue;
|
|
consalloc(name);
|
|
}
|
|
closedir(dir);
|
|
free(attrib);
|
|
if (!consoles)
|
|
goto fallback;
|
|
return ret;
|
|
|
|
}
|
|
/*
|
|
* Detection of devices used for Linux system console using
|
|
* kernel parameter on the kernels command line.
|
|
*/
|
|
if ((cmdline = oneline("/proc/cmdline"))) {
|
|
char *words= cmdline, *token;
|
|
DIR *dir;
|
|
|
|
dir = opendir("/dev");
|
|
if (!dir) {
|
|
free(cmdline);
|
|
goto fallback;
|
|
}
|
|
while ((token = strsep(&words, " \t\r\n"))) {
|
|
#ifdef TIOCGDEV
|
|
unsigned int devnum;
|
|
#else
|
|
struct vt_stat vt;
|
|
struct stat st;
|
|
#endif
|
|
char *colon, *name;
|
|
|
|
if (*token != 'c')
|
|
continue;
|
|
|
|
if (strncmp(token, "console=", 8) != 0)
|
|
continue;
|
|
token += 8;
|
|
|
|
if (strcmp(token, "brl") == 0)
|
|
token += 4;
|
|
if ((colon = strchr(token, ',')))
|
|
*colon = '\0';
|
|
|
|
if (asprintf(&name, "/dev/%s", token) < 0)
|
|
continue;
|
|
|
|
if ((fd = open(name, O_RDWR|O_NONBLOCK|O_NOCTTY|O_CLOEXEC)) < 0) {
|
|
free(name);
|
|
continue;
|
|
}
|
|
free(name);
|
|
#ifdef TIOCGDEV
|
|
if (ioctl (fd, TIOCGDEV, &devnum) < 0) {
|
|
close(fd);
|
|
continue;
|
|
}
|
|
comparedev = (dev_t)devnum;
|
|
#else
|
|
if (fstat(fd, &st) < 0) {
|
|
close(fd);
|
|
continue;
|
|
}
|
|
comparedev = st.st_rdev;
|
|
if (comparedev == makedev(TTY_MAJOR, 0)) {
|
|
if (ioctl(fd, VT_GETSTATE, &vt) < 0) {
|
|
close(fd);
|
|
continue;
|
|
}
|
|
comparedev = makedev(TTY_MAJOR, (int)vt.v_active);
|
|
}
|
|
#endif
|
|
close(fd);
|
|
|
|
name = scandev(dir);
|
|
if (!name)
|
|
continue;
|
|
consalloc(name);
|
|
}
|
|
closedir(dir);
|
|
free(cmdline);
|
|
/*
|
|
* Detection of the device used for Linux system console using
|
|
* the ioctl TIOCGDEV if available (e.g. official 2.6.38).
|
|
*/
|
|
if (!consoles) {
|
|
#ifdef TIOCGDEV
|
|
unsigned int devnum;
|
|
const char *name;
|
|
|
|
if (!device || *device == '\0')
|
|
fd = dup(fallback);
|
|
else fd = open(device, O_RDWR|O_NONBLOCK|O_NOCTTY|O_CLOEXEC);
|
|
|
|
if (fd < 0)
|
|
goto fallback;
|
|
|
|
if (ioctl (fd, TIOCGDEV, &devnum) < 0) {
|
|
close(fd);
|
|
goto fallback;
|
|
}
|
|
comparedev = (dev_t)devnum;
|
|
close(fd);
|
|
|
|
if (device && *device != '\0')
|
|
name = device;
|
|
else name = ttyname(fallback);
|
|
|
|
if (!name)
|
|
name = "/dev/tty1";
|
|
|
|
consalloc(strdup(name));
|
|
if (consoles) {
|
|
if (!device || *device == '\0')
|
|
consoles->fd = fallback;
|
|
return ret;
|
|
}
|
|
#endif
|
|
goto fallback;
|
|
}
|
|
return ret;
|
|
}
|
|
#endif /* __linux __ */
|
|
fallback:
|
|
if (fallback >= 0) {
|
|
const char *name;
|
|
|
|
if (device && *device != '\0')
|
|
name = device;
|
|
else name = ttyname(fallback);
|
|
|
|
if (!name)
|
|
name = "/dev/tty";
|
|
|
|
consalloc(strdup(name));
|
|
if (consoles)
|
|
consoles->fd = fallback;
|
|
}
|
|
return ret;
|
|
}
|