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20c03b7be2
systemd/src/log.c
Lennart Poettering 20c03b7be2 don't make up buffer sizes, use standard LINE_MAX instead
2011-04-07 18:48:50 +02:00

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/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
/***
This file is part of systemd.
Copyright 2010 Lennart Poettering
systemd 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.
systemd 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 systemd; If not, see <http://www.gnu.org/licenses/>.
***/
#include <stdarg.h>
#include <stdio.h>
#include <errno.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/socket.h>
#include <sys/un.h>
#include "log.h"
#include "util.h"
#include "macro.h"
#define SYSLOG_TIMEOUT_USEC (5*USEC_PER_SEC)
static LogTarget log_target = LOG_TARGET_CONSOLE;
static int log_max_level = LOG_INFO;
static int console_fd = STDERR_FILENO;
static int syslog_fd = -1;
static int kmsg_fd = -1;
static bool syslog_is_stream = false;
static bool show_color = false;
static bool show_location = false;
/* Akin to glibc's __abort_msg; which is private and we hence cannot
* use here. */
static char *log_abort_msg = NULL;
void log_close_console(void) {
if (console_fd < 0)
return;
if (getpid() == 1) {
if (console_fd >= 3)
close_nointr_nofail(console_fd);
console_fd = -1;
}
}
static int log_open_console(void) {
if (console_fd >= 0)
return 0;
if (getpid() == 1) {
if ((console_fd = open_terminal("/dev/console", O_WRONLY|O_NOCTTY|O_CLOEXEC)) < 0) {
log_error("Failed to open /dev/console for logging: %s", strerror(-console_fd));
return console_fd;
}
log_debug("Successfully opened /dev/console for logging.");
} else
console_fd = STDERR_FILENO;
return 0;
}
void log_close_kmsg(void) {
if (kmsg_fd < 0)
return;
close_nointr_nofail(kmsg_fd);
kmsg_fd = -1;
}
static int log_open_kmsg(void) {
if (kmsg_fd >= 0)
return 0;
if ((kmsg_fd = open("/dev/kmsg", O_WRONLY|O_NOCTTY|O_CLOEXEC)) < 0) {
log_error("Failed to open /dev/kmsg for logging: %s", strerror(errno));
return -errno;
}
log_debug("Successfully opened /dev/kmsg for logging.");
return 0;
}
void log_close_syslog(void) {
if (syslog_fd < 0)
return;
close_nointr_nofail(syslog_fd);
syslog_fd = -1;
}
static int create_log_socket(int type) {
struct timeval tv;
int fd;
if ((fd = socket(AF_UNIX, type|SOCK_CLOEXEC, 0)) < 0)
return -errno;
/* Make sure we don't block for more than 5s when talking to
* syslog */
timeval_store(&tv, SYSLOG_TIMEOUT_USEC);
if (setsockopt(fd, SOL_SOCKET, SO_SNDTIMEO, &tv, sizeof(tv)) < 0) {
close_nointr_nofail(fd);
return -errno;
}
return fd;
}
static int log_open_syslog(void) {
union {
struct sockaddr sa;
struct sockaddr_un un;
} sa;
int r;
if (syslog_fd >= 0)
return 0;
zero(sa);
sa.un.sun_family = AF_UNIX;
strncpy(sa.un.sun_path, "/dev/log", sizeof(sa.un.sun_path));
if ((syslog_fd = create_log_socket(SOCK_DGRAM)) < 0) {
r = -errno;
goto fail;
}
if (connect(syslog_fd, &sa.sa, sizeof(sa)) < 0) {
close_nointr_nofail(syslog_fd);
/* Some legacy syslog systems still use stream
* sockets. They really shouldn't. But what can we
* do... */
if ((syslog_fd = create_log_socket(SOCK_STREAM)) < 0) {
r = -errno;
goto fail;
}
if (connect(syslog_fd, &sa.sa, sizeof(sa)) < 0) {
r = -errno;
goto fail;
}
syslog_is_stream = true;
} else
syslog_is_stream = false;
log_debug("Successfully opened syslog for logging.");
return 0;
fail:
log_close_syslog();
log_debug("Failed to open syslog for logging: %s", strerror(-r));
return r;
}
int log_open(void) {
int r;
/* If we don't use the console we close it here, to not get
* killed by SAK. If we don't use syslog we close it here so
* that we are not confused by somebody deleting the socket in
* the fs. If we don't use /dev/kmsg we still keep it open,
* because there is no reason to close it. */
if (log_target == LOG_TARGET_NULL) {
log_close_syslog();
log_close_console();
return 0;
}
if (log_target != LOG_TARGET_AUTO ||
getpid() == 1 ||
isatty(STDERR_FILENO) <= 0) {
if (log_target == LOG_TARGET_AUTO ||
log_target == LOG_TARGET_SYSLOG_OR_KMSG ||
log_target == LOG_TARGET_SYSLOG)
if ((r = log_open_syslog()) >= 0) {
log_close_console();
return r;
}
if (log_target == LOG_TARGET_AUTO ||
log_target == LOG_TARGET_SYSLOG_OR_KMSG ||
log_target == LOG_TARGET_KMSG)
if ((r = log_open_kmsg()) >= 0) {
log_close_syslog();
log_close_console();
return r;
}
}
log_close_syslog();
/* Get the real /dev/console if we are PID=1, hence reopen */
log_close_console();
return log_open_console();
}
void log_set_target(LogTarget target) {
assert(target >= 0);
assert(target < _LOG_TARGET_MAX);
log_target = target;
}
void log_set_max_level(int level) {
assert((level & LOG_PRIMASK) == level);
log_max_level = level;
}
static int write_to_console(
int level,
const char*file,
int line,
const char *func,
const char *buffer) {
char location[64];
struct iovec iovec[5];
unsigned n = 0;
bool highlight;
if (console_fd < 0)
return 0;
snprintf(location, sizeof(location), "(%s:%u) ", file, line);
char_array_0(location);
highlight = LOG_PRI(level) <= LOG_ERR && show_color;
zero(iovec);
if (show_location)
IOVEC_SET_STRING(iovec[n++], location);
if (highlight)
IOVEC_SET_STRING(iovec[n++], ANSI_HIGHLIGHT_ON);
IOVEC_SET_STRING(iovec[n++], buffer);
if (highlight)
IOVEC_SET_STRING(iovec[n++], ANSI_HIGHLIGHT_OFF);
IOVEC_SET_STRING(iovec[n++], "\n");
if (writev(console_fd, iovec, n) < 0)
return -errno;
return 1;
}
static int write_to_syslog(
int level,
const char*file,
int line,
const char *func,
const char *buffer) {
char header_priority[16], header_time[64], header_pid[16];
struct iovec iovec[5];
struct msghdr msghdr;
time_t t;
struct tm *tm;
if (syslog_fd < 0)
return 0;
snprintf(header_priority, sizeof(header_priority), "<%i>", level);
char_array_0(header_priority);
t = (time_t) (now(CLOCK_REALTIME) / USEC_PER_SEC);
if (!(tm = localtime(&t)))
return -EINVAL;
if (strftime(header_time, sizeof(header_time), "%h %e %T ", tm) <= 0)
return -EINVAL;
snprintf(header_pid, sizeof(header_pid), "[%lu]: ", (unsigned long) getpid());
char_array_0(header_pid);
zero(iovec);
IOVEC_SET_STRING(iovec[0], header_priority);
IOVEC_SET_STRING(iovec[1], header_time);
IOVEC_SET_STRING(iovec[2], program_invocation_short_name);
IOVEC_SET_STRING(iovec[3], header_pid);
IOVEC_SET_STRING(iovec[4], buffer);
/* When using syslog via SOCK_STREAM separate the messages by NUL chars */
if (syslog_is_stream)
iovec[4].iov_len++;
zero(msghdr);
msghdr.msg_iov = iovec;
msghdr.msg_iovlen = ELEMENTSOF(iovec);
for (;;) {
ssize_t n;
if ((n = sendmsg(syslog_fd, &msghdr, MSG_NOSIGNAL)) < 0)
return -errno;
if (!syslog_is_stream ||
(size_t) n >= IOVEC_TOTAL_SIZE(iovec, ELEMENTSOF(iovec)))
break;
IOVEC_INCREMENT(iovec, ELEMENTSOF(iovec), n);
}
return 1;
}
static int write_to_kmsg(
int level,
const char*file,
int line,
const char *func,
const char *buffer) {
char header_priority[16], header_pid[16];
struct iovec iovec[5];
if (kmsg_fd < 0)
return 0;
snprintf(header_priority, sizeof(header_priority), "<%i>", level);
char_array_0(header_priority);
snprintf(header_pid, sizeof(header_pid), "[%lu]: ", (unsigned long) getpid());
char_array_0(header_pid);
zero(iovec);
IOVEC_SET_STRING(iovec[0], header_priority);
IOVEC_SET_STRING(iovec[1], program_invocation_short_name);
IOVEC_SET_STRING(iovec[2], header_pid);
IOVEC_SET_STRING(iovec[3], buffer);
IOVEC_SET_STRING(iovec[4], "\n");
if (writev(kmsg_fd, iovec, ELEMENTSOF(iovec)) < 0)
return -errno;
return 1;
}
static int log_dispatch(
int level,
const char*file,
int line,
const char *func,
char *buffer) {
int r = 0;
if (log_target == LOG_TARGET_NULL)
return 0;
/* Patch in LOG_DAEMON facility if necessary */
if ((level & LOG_FACMASK) == 0)
level = LOG_DAEMON | LOG_PRI(level);
do {
char *e;
int k = 0;
buffer += strspn(buffer, NEWLINE);
if (buffer[0] == 0)
break;
if ((e = strpbrk(buffer, NEWLINE)))
*(e++) = 0;
if (log_target == LOG_TARGET_AUTO ||
log_target == LOG_TARGET_SYSLOG_OR_KMSG ||
log_target == LOG_TARGET_SYSLOG) {
if ((k = write_to_syslog(level, file, line, func, buffer)) < 0) {
log_close_syslog();
log_open_kmsg();
} else if (k > 0)
r++;
}
if (k <= 0 &&
(log_target == LOG_TARGET_AUTO ||
log_target == LOG_TARGET_SYSLOG_OR_KMSG ||
log_target == LOG_TARGET_KMSG)) {
if ((k = write_to_kmsg(level, file, line, func, buffer)) < 0) {
log_close_kmsg();
log_open_console();
} else if (k > 0)
r++;
}
if (k <= 0 &&
(k = write_to_console(level, file, line, func, buffer)) < 0)
return k;
buffer = e;
} while (buffer);
return r;
}
int log_dump_internal(
int level,
const char*file,
int line,
const char *func,
char *buffer) {
int saved_errno, r;
/* This modifies the buffer... */
if (_likely_(LOG_PRI(level) > log_max_level))
return 0;
saved_errno = errno;
r = log_dispatch(level, file, line, func, buffer);
errno = saved_errno;
return r;
}
int log_meta(
int level,
const char*file,
int line,
const char *func,
const char *format, ...) {
char buffer[LINE_MAX];
int saved_errno, r;
va_list ap;
if (_likely_(LOG_PRI(level) > log_max_level))
return 0;
saved_errno = errno;
va_start(ap, format);
vsnprintf(buffer, sizeof(buffer), format, ap);
va_end(ap);
char_array_0(buffer);
r = log_dispatch(level, file, line, func, buffer);
errno = saved_errno;
return r;
}
void log_assert(
const char*file,
int line,
const char *func,
const char *format, ...) {
static char buffer[LINE_MAX];
int saved_errno = errno;
va_list ap;
va_start(ap, format);
vsnprintf(buffer, sizeof(buffer), format, ap);
va_end(ap);
char_array_0(buffer);
log_abort_msg = buffer;
log_dispatch(LOG_CRIT, file, line, func, buffer);
abort();
/* If the user chose to ignore this SIGABRT, we are happy to go on, as if nothing happened. */
errno = saved_errno;
}
int log_set_target_from_string(const char *e) {
LogTarget t;
if ((t = log_target_from_string(e)) < 0)
return -EINVAL;
log_set_target(t);
return 0;
}
int log_set_max_level_from_string(const char *e) {
int t;
if ((t = log_level_from_string(e)) < 0)
return -EINVAL;
log_set_max_level(t);
return 0;
}
void log_parse_environment(void) {
const char *e;
if ((e = getenv("SYSTEMD_LOG_TARGET")))
if (log_set_target_from_string(e) < 0)
log_warning("Failed to parse log target %s. Ignoring.", e);
if ((e = getenv("SYSTEMD_LOG_LEVEL")))
if (log_set_max_level_from_string(e) < 0)
log_warning("Failed to parse log level %s. Ignoring.", e);
if ((e = getenv("SYSTEMD_LOG_COLOR")))
if (log_show_color_from_string(e) < 0)
log_warning("Failed to parse bool %s. Ignoring.", e);
if ((e = getenv("SYSTEMD_LOG_LOCATION")))
if (log_show_location_from_string(e) < 0)
log_warning("Failed to parse bool %s. Ignoring.", e);
}
LogTarget log_get_target(void) {
return log_target;
}
int log_get_max_level(void) {
return log_max_level;
}
void log_show_color(bool b) {
show_color = b;
}
void log_show_location(bool b) {
show_location = b;
}
int log_show_color_from_string(const char *e) {
int t;
if ((t = parse_boolean(e)) < 0)
return -EINVAL;
log_show_color(t);
return 0;
}
int log_show_location_from_string(const char *e) {
int t;
if ((t = parse_boolean(e)) < 0)
return -EINVAL;
log_show_location(t);
return 0;
}
static const char *const log_target_table[] = {
[LOG_TARGET_CONSOLE] = "console",
[LOG_TARGET_SYSLOG] = "syslog",
[LOG_TARGET_KMSG] = "kmsg",
[LOG_TARGET_SYSLOG_OR_KMSG] = "syslog-or-kmsg",
[LOG_TARGET_NULL] = "null",
[LOG_TARGET_AUTO] = "auto"
};
DEFINE_STRING_TABLE_LOOKUP(log_target, LogTarget);
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