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Systemd/src/shared/log.c
Lennart Poettering 5430f7f2bc relicense to LGPLv2.1 (with exceptions) 
We finally got the OK from all contributors with non-trivial commits to
relicense systemd from GPL2+ to LGPL2.1+.

Some udev bits continue to be GPL2+ for now, but we are looking into
relicensing them too, to allow free copy/paste of all code within
systemd.

The bits that used to be MIT continue to be MIT.

The big benefit of the relicensing is that closed source code may now
link against libsystemd-login.so and friends.
2012-04-12 00:24:39 +02:00

748 lines
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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 Lesser General Public License as published by
the Free Software Foundation; either version 2.1 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser 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 <stddef.h>
#include "log.h"
#include "util.h"
#include "macro.h"
#include "socket-util.h"
#define SNDBUF_SIZE (8*1024*1024)
static LogTarget log_target = LOG_TARGET_CONSOLE;
static int log_max_level = LOG_INFO;
static int log_facility = LOG_DAEMON;
static int console_fd = STDERR_FILENO;
static int syslog_fd = -1;
static int kmsg_fd = -1;
static int journal_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) {
console_fd = open_terminal("/dev/console", O_WRONLY|O_NOCTTY|O_CLOEXEC);
if (console_fd < 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;
kmsg_fd = open("/dev/kmsg", O_WRONLY|O_NOCTTY|O_CLOEXEC);
if (kmsg_fd < 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) {
int fd;
/* All output to the syslog/journal fds we do asynchronously,
* and if the buffers are full we just drop the messages */
fd = socket(AF_UNIX, type|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
if (fd < 0)
return -errno;
fd_inc_sndbuf(fd, SNDBUF_SIZE);
return fd;
}
static int log_open_syslog(void) {
union sockaddr_union 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));
syslog_fd = create_log_socket(SOCK_DGRAM);
if (syslog_fd < 0) {
r = syslog_fd;
goto fail;
}
if (connect(syslog_fd, &sa.sa, offsetof(struct sockaddr_un, sun_path) + strlen(sa.un.sun_path)) < 0) {
close_nointr_nofail(syslog_fd);
/* Some legacy syslog systems still use stream
* sockets. They really shouldn't. But what can we
* do... */
syslog_fd = create_log_socket(SOCK_STREAM);
if (syslog_fd < 0) {
r = syslog_fd;
goto fail;
}
if (connect(syslog_fd, &sa.sa, offsetof(struct sockaddr_un, sun_path) + strlen(sa.un.sun_path)) < 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;
}
void log_close_journal(void) {
if (journal_fd < 0)
return;
close_nointr_nofail(journal_fd);
journal_fd = -1;
}
static int log_open_journal(void) {
union sockaddr_union sa;
int r;
if (journal_fd >= 0)
return 0;
journal_fd = create_log_socket(SOCK_DGRAM);
if (journal_fd < 0) {
r = journal_fd;
goto fail;
}
zero(sa);
sa.un.sun_family = AF_UNIX;
strncpy(sa.un.sun_path, "/run/systemd/journal/socket", sizeof(sa.un.sun_path));
if (connect(journal_fd, &sa.sa, offsetof(struct sockaddr_un, sun_path) + strlen(sa.un.sun_path)) < 0) {
r = -errno;
goto fail;
}
log_debug("Successfully opened journal for logging.");
return 0;
fail:
log_close_journal();
log_debug("Failed to open journal 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_journal();
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_JOURNAL_OR_KMSG ||
log_target == LOG_TARGET_JOURNAL) {
r = log_open_journal();
if (r >= 0) {
log_close_syslog();
log_close_console();
return r;
}
}
if (log_target == LOG_TARGET_SYSLOG_OR_KMSG ||
log_target == LOG_TARGET_SYSLOG) {
r = log_open_syslog();
if (r >= 0) {
log_close_journal();
log_close_console();
return r;
}
}
if (log_target == LOG_TARGET_AUTO ||
log_target == LOG_TARGET_JOURNAL_OR_KMSG ||
log_target == LOG_TARGET_SYSLOG_OR_KMSG ||
log_target == LOG_TARGET_KMSG) {
r = log_open_kmsg();
if (r >= 0) {
log_close_journal();
log_close_syslog();
log_close_console();
return r;
}
}
}
log_close_journal();
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_close(void) {
log_close_journal();
log_close_syslog();
log_close_kmsg();
log_close_console();
}
void log_forget_fds(void) {
console_fd = kmsg_fd = syslog_fd = journal_fd = -1;
}
void log_set_max_level(int level) {
assert((level & LOG_PRIMASK) == level);
log_max_level = level;
}
void log_set_facility(int facility) {
log_facility = facility;
}
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;
highlight = LOG_PRI(level) <= LOG_ERR && show_color;
zero(iovec);
if (show_location) {
snprintf(location, sizeof(location), "(%s:%u) ", file, line);
char_array_0(location);
IOVEC_SET_STRING(iovec[n++], location);
}
if (highlight)
IOVEC_SET_STRING(iovec[n++], ANSI_HIGHLIGHT_RED_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;
n = sendmsg(syslog_fd, &msghdr, MSG_NOSIGNAL);
if (n < 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 write_to_journal(
int level,
const char*file,
int line,
const char *func,
const char *buffer) {
char header[LINE_MAX];
struct iovec iovec[3];
struct msghdr mh;
if (journal_fd < 0)
return 0;
snprintf(header, sizeof(header),
"PRIORITY=%i\n"
"SYSLOG_FACILITY=%i\n"
"CODE_FILE=%s\n"
"CODE_LINE=%i\n"
"CODE_FUNCTION=%s\n"
"MESSAGE=",
LOG_PRI(level),
LOG_FAC(level),
file,
line,
func);
char_array_0(header);
zero(iovec);
IOVEC_SET_STRING(iovec[0], header);
IOVEC_SET_STRING(iovec[1], buffer);
IOVEC_SET_STRING(iovec[2], "\n");
zero(mh);
mh.msg_iov = iovec;
mh.msg_iovlen = ELEMENTSOF(iovec);
if (sendmsg(journal_fd, &mh, MSG_NOSIGNAL) < 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_facility | 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_JOURNAL_OR_KMSG ||
log_target == LOG_TARGET_JOURNAL) {
k = write_to_journal(level, file, line, func, buffer);
if (k < 0) {
if (k != -EAGAIN)
log_close_journal();
log_open_kmsg();
} else if (k > 0)
r++;
}
if (log_target == LOG_TARGET_SYSLOG_OR_KMSG ||
log_target == LOG_TARGET_SYSLOG) {
k = write_to_syslog(level, file, line, func, buffer);
if (k < 0) {
if (k != -EAGAIN)
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)) {
k = write_to_kmsg(level, file, line, func, buffer);
if (k < 0) {
log_close_kmsg();
log_open_console();
} else if (k > 0)
r++;
}
if (k <= 0) {
k = write_to_console(level, file, line, func, buffer);
if (k < 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_metav(
int level,
const char*file,
int line,
const char *func,
const char *format,
va_list ap) {
char buffer[LINE_MAX];
int saved_errno, r;
if (_likely_(LOG_PRI(level) > log_max_level))
return 0;
saved_errno = errno;
vsnprintf(buffer, sizeof(buffer), format, ap);
char_array_0(buffer);
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, ...) {
int r;
va_list ap;
va_start(ap, format);
r = log_metav(level, file, line, func, format, ap);
va_end(ap);
return r;
}
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wformat-nonliteral"
_noreturn_ static void log_assert(const char *text, const char *file, int line, const char *func, const char *format) {
static char buffer[LINE_MAX];
snprintf(buffer, sizeof(buffer), format, text, file, line, func);
char_array_0(buffer);
log_abort_msg = buffer;
log_dispatch(LOG_CRIT, file, line, func, buffer);
abort();
}
#pragma GCC diagnostic pop
_noreturn_ void log_assert_failed(const char *text, const char *file, int line, const char *func) {
log_assert(text, file, line, func, "Assertion '%s' failed at %s:%u, function %s(). Aborting.");
}
_noreturn_ void log_assert_failed_unreachable(const char *text, const char *file, int line, const char *func) {
log_assert(text, file, line, func, "Code should not be reached '%s' at %s:%u, function %s(). Aborting.");
}
int log_set_target_from_string(const char *e) {
LogTarget t;
t = log_target_from_string(e);
if (t < 0)
return -EINVAL;
log_set_target(t);
return 0;
}
int log_set_max_level_from_string(const char *e) {
int t;
t = log_level_from_string(e);
if (t < 0)
return t;
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;
t = parse_boolean(e);
if (t < 0)
return t;
log_show_color(t);
return 0;
}
int log_show_location_from_string(const char *e) {
int t;
t = parse_boolean(e);
if (t < 0)
return t;
log_show_location(t);
return 0;
}
static const char *const log_target_table[] = {
[LOG_TARGET_CONSOLE] = "console",
[LOG_TARGET_KMSG] = "kmsg",
[LOG_TARGET_JOURNAL] = "journal",
[LOG_TARGET_JOURNAL_OR_KMSG] = "journal-or-kmsg",
[LOG_TARGET_SYSLOG] = "syslog",
[LOG_TARGET_SYSLOG_OR_KMSG] = "syslog-or-kmsg",
[LOG_TARGET_AUTO] = "auto",
[LOG_TARGET_NULL] = "null"
};
DEFINE_STRING_TABLE_LOOKUP(log_target, LogTarget);
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