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sysvinit/src/bootlogd.c

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/*
* bootlogd.c Store output from the console during bootup into a file.
* The file is usually located on the /var partition, and
* gets written (and fsynced) as soon as possible.
*
* Version: @(#)bootlogd 2.86pre 12-Jan-2004 miquels@cistron.nl
*
* Bugs: Uses openpty(), only available in glibc. Sorry.
*
* This file is part of the sysvinit suite,
* Copyright (C) 1991-2004 Miquel van Smoorenburg.
*
* 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 of the License, 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; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
*/
#include <sys/types.h>
#include <sys/time.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <sys/utsname.h>
#include <time.h>
#include <stdio.h>
#include <errno.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <signal.h>
#include <getopt.h>
#include <dirent.h>
#include <fcntl.h>
#ifdef __linux__
#include <pty.h>
#endif
#if defined (__linux__) || defined(__GNU__)
#include <sys/sysmacros.h>
#endif
#ifdef __FreeBSD__
#include <termios.h>
#include <libutil.h>
#endif
#include <ctype.h>
#ifdef __linux__
#include <sys/mount.h>
#endif
#include "bootlogd.h"
#define MAX_CONSOLES 16
#define KERNEL_COMMAND_LENGTH 4096
char ringbuf[32768];
char *endptr = ringbuf + sizeof(ringbuf);
char *inptr = ringbuf;
char *outptr = ringbuf;
int got_signal = 0;
int didnl = 1;
int createlogfile = 0;
int syncalot = 0;
struct real_cons {
char name[1024];
int fd;
};
/*
* Console devices as listed on the kernel command line and
* the mapping to actual devices in /dev
*/
struct consdev {
char *cmdline;
char *dev1;
char *dev2;
} consdev[] = {
{ "ttyB", "/dev/ttyB%s", NULL },
{ "ttySC", "/dev/ttySC%s", "/dev/ttsc/%s" },
{ "ttyS", "/dev/ttyS%s", "/dev/tts/%s" },
{ "tty", "/dev/tty%s", "/dev/vc/%s" },
{ "hvc", "/dev/hvc%s", "/dev/hvc/%s" },
{ NULL, NULL, NULL },
};
/*
* Devices to try as console if not found on kernel command line.
* Tried from left to right (as opposed to kernel cmdline).
*/
char *defcons[] = { "tty0", "hvc0", "ttyS0", "ttySC0", "ttyB0", NULL };
/*
* Catch signals.
*/
void handler(int sig)
{
got_signal = sig;
}
/*
* chdir with error message on fail.
*/
static int chdir_int(const char *path)
{
int ret;
if ((ret = chdir(path)) != 0) {
const char *msgprefix = "bootlogd: %s";
char msg[PATH_MAX + sizeof(msgprefix)];
snprintf(msg, sizeof(msg), msgprefix, path);
perror(msg);
}
return ret;
}
/*
* Scan /dev and find the device name.
*/
static int findtty(char *res, const char *startdir, int rlen, dev_t dev)
{
DIR *dir;
struct dirent *ent;
struct stat st;
int r = -1;
char *olddir = getcwd(NULL, 0);
if (chdir_int(startdir) < 0 || (dir = opendir(".")) == NULL) {
chdir_int(olddir);
return -1;
}
while ((ent = readdir(dir)) != NULL) {
if (lstat(ent->d_name, &st) != 0)
continue;
if (S_ISDIR(st.st_mode)
&& 0 != strcmp(".", ent->d_name)
&& 0 != strcmp("..", ent->d_name)) {
char *path = malloc(rlen);
snprintf(path, rlen, "%s/%s", startdir, ent->d_name);
r = findtty(res, path, rlen, dev);
free(path);
if (0 == r) {
closedir(dir);
chdir_int(olddir);
return 0;
}
continue;
}
if (!S_ISCHR(st.st_mode))
continue;
if (st.st_rdev == dev) {
if ( (int) (strlen(ent->d_name) + strlen(startdir) + 1) >= rlen) {
fprintf(stderr, "bootlogd: console device name too long\n");
closedir(dir);
chdir_int(olddir);
return -1;
} else {
snprintf(res, rlen, "%s/%s", startdir, ent->d_name);
closedir(dir);
chdir_int(olddir);
return 0;
}
}
}
closedir(dir);
chdir_int(olddir);
return r;
}
/*
* For some reason, openpty() in glibc sometimes doesn't
* work at boot-time. It must be a bug with old-style pty
* names, as new-style (/dev/pts) is not available at that
* point. So, we find a pty/tty pair ourself if openpty()
* fails for whatever reason.
*/
int findpty(int *master, int *slave, char *name)
{
char pty[16];
char tty[16];
int i, j;
int found;
if (openpty(master, slave, name, NULL, NULL) >= 0)
return 0;
found = 0;
for (i = 'p'; i <= 'z'; i++) {
for (j = '0'; j <= 'f'; j++) {
if (j == '9' + 1) j = 'a';
sprintf(pty, "/dev/pty%c%c", i, j);
sprintf(tty, "/dev/tty%c%c", i, j);
if ((*master = open(pty, O_RDWR|O_NOCTTY)) >= 0) {
*slave = open(tty, O_RDWR|O_NOCTTY);
if (*slave >= 0) {
found = 1;
break;
}
}
}
if (found) break;
}
if (!found) return -1;
if (name) strcpy(name, tty);
return 0;
}
static int istty(const char *dev)
{
int fd, ret;
fd = open(dev, O_RDONLY|O_NONBLOCK);
if (fd < 0)
return 0;
ret = isatty(fd);
close(fd);
return ret;
}
/*
* See if a console taken from the kernel command line maps
* to a character device we know about, and if we can open it.
*/
int isconsole(char *s, char *res, int rlen)
{
struct consdev *c;
int l, sl, i, fd;
char *p, *q;
sl = strlen(s);
for (c = consdev; c->cmdline; c++) {
l = strlen(c->cmdline);
if (sl <= l) continue;
p = s + l;
if (strncmp(s, c->cmdline, l) != 0)
continue;
for (i = 0; i < 2; i++) {
snprintf(res, rlen, i ? c->dev1 : c->dev2, p);
if ((q = strchr(res, ',')) != NULL) *q = 0;
if ((fd = open(res, O_RDONLY|O_NONBLOCK)) >= 0) {
close(fd);
return 1;
}
}
}
/* Fallback: accept any TTY device */
snprintf(res, rlen, "/dev/%s", s);
if ((q = strchr(res, ',')) != NULL) *q = 0;
if (istty(res))
return 1;
return 0;
}
/*
* Find out the _real_ console(s). Assume that stdin is connected to
* the console device (/dev/console).
*/
int consolenames(struct real_cons *cons, int max_consoles)
{
#ifdef TIOCGDEV
unsigned int kdev;
#endif
struct stat st, st2;
char buf[KERNEL_COMMAND_LENGTH];
char *p;
int didmount = 0;
int n;
int fd;
int considx, num_consoles = 0;
#ifdef __linux__
/*
* Read /proc/cmdline.
*/
stat("/", &st);
if (stat("/proc", &st2) < 0) {
perror("bootlogd: /proc");
return 0;
}
if (st.st_dev == st2.st_dev) {
if (mount("proc", "/proc", "proc", 0, NULL) < 0) {
perror("bootlogd: mount /proc");
return -1;
}
didmount = 1;
}
n = -1;
if ((fd = open("/proc/cmdline", O_RDONLY)) < 0) {
perror("bootlogd: /proc/cmdline");
} else {
buf[0] = 0;
if ((n = read(fd, buf, KERNEL_COMMAND_LENGTH - 1)) < 0)
perror("bootlogd: /proc/cmdline");
close(fd);
}
if (didmount) umount("/proc");
if (n < 0) return 0;
/*
* OK, so find console= in /proc/cmdline.
* Parse in reverse, opening as we go.
*/
p = buf + n;
*p-- = 0;
while (p >= buf) {
if (*p == ' ' || *p == '\t' || *p == '\r' || *p == '\n') {
*p-- = 0;
continue;
}
if (strncmp(p, "console=", 8) == 0 &&
isconsole(p + 8, cons[num_consoles].name, sizeof(cons[num_consoles].name))) {
/*
* Suppress duplicates
*/
for (considx = 0; considx < num_consoles; considx++) {
if (!strcmp(cons[num_consoles].name, cons[considx].name)) {
goto dontuse;
}
}
num_consoles++;
if (num_consoles >= max_consoles) {
break;
}
}
dontuse:
p--;
}
if (num_consoles > 0) return num_consoles;
#endif
fstat(0, &st);
if (major(st.st_rdev) != 5 || minor(st.st_rdev) != 1) {
/*
* Old kernel, can find real device easily.
*/
int r = findtty(cons[num_consoles].name, "/dev",
sizeof(cons[num_consoles].name), st.st_rdev);
if (!r)
num_consoles++;
}
if (num_consoles > 0) return num_consoles;
#ifdef TIOCGDEV
# ifndef ENOIOCTLCMD
# define ENOIOCTLCMD 515
# endif
if (ioctl(0, TIOCGDEV, &kdev) == 0) {
int r = findtty(cons[num_consoles].name, "/dev",
sizeof(cons[num_consoles].name), (dev_t)kdev);
if (!r)
num_consoles++;
}
if (num_consoles > 0) return num_consoles;
#endif
/*
* Okay, no console on the command line -
* guess the default console.
*/
for (n = 0; defcons[n]; n++)
if (isconsole(defcons[n], cons[0].name, sizeof(cons[0].name)))
return 1;
fprintf(stderr, "bootlogd: cannot deduce real console device\n");
return 0;
}
/*
* Write data and make sure it's on disk.
*/
void writelog(FILE *fp, unsigned char *ptr, int len, int print_escape_characters)
{
int dosync = 0;
int i;
static int first_run = 1;
static int inside_esc = 0;
for (i = 0; i < len; i++) {
int ignore = 0;
/* prepend date to every line */
if (*(ptr-1) == '\n' || first_run) {
time_t t;
char *s;
time(&t);
s = ctime(&t);
fprintf(fp, "%.24s: ", s);
dosync = 1;
first_run = 0;
}
/* remove escape sequences, but do it in a way that allows us to stop
* in the middle in case the string was cut off */
if (! print_escape_characters)
{
if (inside_esc == 1) {
/* first '[' is special because if we encounter it again, it should be considered the final byte */
if (*ptr == '[') {
/* multi char sequence */
ignore = 1;
inside_esc = 2;
} else {
/* single char sequence */
if (*ptr >= 64 && *ptr <= 95) {
ignore = 1;
}
inside_esc = 0;
}
} else if (inside_esc == 2) {
switch (*ptr) {
case '0' ... '9': /* intermediate chars of escape sequence */
case ';':
case 32 ... 47:
if (inside_esc) {
ignore = 1;
}
break;
case 64 ... 126: /* final char of escape sequence */
if (inside_esc) {
ignore = 1;
inside_esc = 0;
}
break;
}
} else {
switch (*ptr) {
case '\r':
ignore = 1;
break;
case 27: /* ESC */
ignore = 1;
inside_esc = 1;
break;
}
}
} /* end of if we should filter escape characters */
if (!ignore) {
fwrite(ptr, sizeof(char), 1, fp);
}
ptr++;
}
if (dosync) {
fflush(fp);
if (syncalot) {
fdatasync(fileno(fp));
}
}
outptr += len;
if (outptr >= endptr)
outptr = ringbuf;
}
/*
* Print usage message and exit.
*/
void usage(void)
{
fprintf(stderr, "Usage: bootlogd [-v] [-r] [-d] [-e] [-s] [-c] [-p pidfile] [-l logfile]\n");
exit(1);
}
int open_nb(char *buf)
{
int fd, n;
if ((fd = open(buf, O_WRONLY|O_NONBLOCK|O_NOCTTY)) < 0)
return -1;
n = fcntl(fd, F_GETFL);
n &= ~(O_NONBLOCK);
fcntl(fd, F_SETFL, n);
return fd;
}
/*
* We got a write error on the real console. If its an EIO,
* somebody hung up our filedescriptor, so try to re-open it.
*/
int write_err(int pts, int realfd, char *realcons, int e)
{
int fd;
if (e != EIO) {
werr:
close(pts);
fprintf(stderr, "bootlogd: writing to console: %s\n",
strerror(e));
return -1;
}
close(realfd);
if ((fd = open_nb(realcons)) < 0)
goto werr;
return fd;
}
int main(int argc, char **argv)
{
FILE *fp;
struct timeval tv;
fd_set fds;
char buf[1024];
char *p;
char *logfile;
char *pidfile;
int rotate;
int dontfork;
int ptm, pts;
/* int realfd; -- this is now unused */
int n, m, i;
int todo;
#ifndef __linux__ /* BSD-style ioctl needs an argument. */
int on = 1;
#endif
int considx;
struct real_cons cons[MAX_CONSOLES];
int num_consoles, consoles_left;
int print_escape_sequence = 0;
fp = NULL;
logfile = LOGFILE;
pidfile = NULL;
rotate = 0;
dontfork = 0;
while ((i = getopt(argc, argv, "cdesl:p:rv")) != EOF) switch(i) {
case 'l':
logfile = optarg;
break;
case 'r':
rotate = 1;
break;
case 'v':
printf("bootlogd - %s\n", VERSION);
exit(0);
break;
case 'p':
pidfile = optarg;
break;
case 'c':
createlogfile = 1;
break;
case 'd':
dontfork = 1;
break;
case 'e':
print_escape_sequence = 1;
break;
case 's':
syncalot = 1;
break;
default:
usage();
break;
}
if (optind < argc) usage();
signal(SIGTERM, handler);
signal(SIGQUIT, handler);
signal(SIGINT, handler);
signal(SIGTTIN, SIG_IGN);
signal(SIGTTOU, SIG_IGN);
signal(SIGTSTP, SIG_IGN);
/*
* Open console device directly.
*/
/*
if (consolename(realcons, sizeof(realcons)) < 0)
return 1;
if (strcmp(realcons, "/dev/tty0") == 0)
strcpy(realcons, "/dev/tty1");
if (strcmp(realcons, "/dev/vc/0") == 0)
strcpy(realcons, "/dev/vc/1");
if ((realfd = open_nb(realcons)) < 0) {
fprintf(stderr, "bootlogd: %s: %s\n", realcons, strerror(errno));
return 1;
}
*/
if ((num_consoles = consolenames(cons, MAX_CONSOLES)) <= 0)
return 1;
consoles_left = num_consoles;
for (considx = 0; considx < num_consoles; considx++) {
if (strcmp(cons[considx].name, "/dev/tty0") == 0)
strcpy(cons[considx].name, "/dev/tty1");
if (strcmp(cons[considx].name, "/dev/vc/0") == 0)
strcpy(cons[considx].name, "/dev/vc/1");
if ((cons[considx].fd = open_nb(cons[considx].name)) < 0) {
fprintf(stderr, "bootlogd: %s: %s\n",
cons[considx].name, strerror(errno));
consoles_left--;
}
}
if (!consoles_left)
return 1;
/*
* Grab a pty, and redirect console messages to it.
*/
ptm = -1;
pts = -1;
buf[0] = 0;
if (findpty(&ptm, &pts, buf) < 0) {
fprintf(stderr,
"bootlogd: cannot allocate pseudo tty: %s\n",
strerror(errno));
return 1;
}
#ifdef __linux__
(void)ioctl(0, TIOCCONS, NULL);
/* Work around bug in 2.1/2.2 kernels. Fixed in 2.2.13 and 2.3.18 */
if ((n = open("/dev/tty0", O_RDWR)) >= 0) {
(void)ioctl(n, TIOCCONS, NULL);
close(n);
}
#endif
#ifdef __linux__
if (ioctl(pts, TIOCCONS, NULL) < 0)
#else /* BSD usage of ioctl TIOCCONS. */
if (ioctl(pts, TIOCCONS, &on) < 0)
#endif
{
fprintf(stderr, "bootlogd: ioctl(%s, TIOCCONS): %s\n",
buf, strerror(errno));
return 1;
}
/*
* Fork and write pidfile if needed.
*/
if (!dontfork) {
pid_t child_pid = fork();
switch (child_pid) {
case -1: /* I am parent and the attempt to create a child failed */
fprintf(stderr, "bootlogd: fork failed: %s\n",
strerror(errno));
exit(1);
break;
case 0: /* I am the child */
break;
default: /* I am parent and got child's pid */
exit(0);
break;
}
setsid();
}
if (pidfile) {
unlink(pidfile);
if ((fp = fopen(pidfile, "w")) != NULL) {
fprintf(fp, "%d\n", (int)getpid());
fclose(fp);
}
fp = NULL;
}
/*
* Read the console messages from the pty, and write
* to the real console and the logfile.
*/
while (!got_signal) {
/*
* We timeout after 5 seconds if we still need to
* open the logfile. There might be buffered messages
* we want to write.
*/
tv.tv_sec = 0;
tv.tv_usec = 500000;
FD_ZERO(&fds);
FD_SET(ptm, &fds);
if (select(ptm + 1, &fds, NULL, NULL, &tv) == 1) {
/*
* See how much space there is left, read.
*/
if ((n = read(ptm, inptr, endptr - inptr)) >= 0) {
/*
* Write data (in chunks if needed)
* to the real output devices.
*/
for (considx = 0; considx < num_consoles; considx++) {
if (cons[considx].fd < 0) continue;
m = n;
p = inptr;
while (m > 0) {
i = write(cons[considx].fd, p, m);
if (i >= 0) {
m -= i;
p += i;
continue;
}
/*
* Handle EIO (somebody hung
* up our filedescriptor)
*/
cons[considx].fd = write_err(pts,
cons[considx].fd,
cons[considx].name, errno);
if (cons[considx].fd >= 0) continue;
/*
* If this was the last console,
* generate a fake signal
*/
if (--consoles_left <= 0) got_signal = 1;
break;
} /* end of while */
} /* end of going through all consoles */
/*
* Increment buffer position. Handle
* wraps, and also drag output pointer
* along if we cross it.
*/
inptr += n;
if (inptr - n < outptr && inptr > outptr)
outptr = inptr;
if (inptr >= endptr)
inptr = ringbuf;
if (outptr >= endptr)
outptr = ringbuf;
} /* end of got data from read */
} /* end of checking select for new data */
/*
* Perhaps we need to open the logfile.
*/
if (fp == NULL && access(logfile, F_OK) == 0) {
if (rotate) {
snprintf(buf, sizeof(buf), "%s~", logfile);
rename(logfile, buf);
}
fp = fopen(logfile, "a");
}
if (fp == NULL && createlogfile)
fp = fopen(logfile, "a");
if (inptr >= outptr)
todo = inptr - outptr;
else
todo = endptr - outptr;
if (fp && todo)
writelog(fp, (unsigned char *)outptr, todo, print_escape_sequence);
} /* end of while waiting for signal */
if (fp) {
if (!didnl) fputc('\n', fp);
fclose(fp);
}
close(pts);
close(ptm);
for (considx = 0; considx < num_consoles; considx++) {
close(cons[considx].fd);
}
return 0;
}
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