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/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
/***
This file is part of systemd.
Copyright 2011 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 <sys/socket.h>
#include <sys/un.h>
#include <errno.h>
#include <stddef.h>
#include "sd-journal.h"
#include "util.h"
/* We open a single fd, and we'll share it with the current process,
* all its threads, and all its subprocesses. This means we need to
* initialize it atomically, and need to operate on it atomically
* never assuming we are the only user */
static int journal_fd(void) {
int fd;
static int fd_plus_one = 0;
retry:
if (fd_plus_one > 0)
return fd_plus_one - 1;
fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0);
if (fd < 0)
return -errno;
if (!__sync_bool_compare_and_swap(&fd_plus_one, 0, fd+1)) {
close_nointr_nofail(fd);
goto retry;
}
return fd;
}
int sd_journal_print(const char *format, ...) {
int r;
va_list ap;
va_start(ap, format);
r = sd_journal_printv(format, ap);
va_end(ap);
return r;
}
int sd_journal_printv(const char *format, va_list ap) {
char buffer[8 + LINE_MAX];
struct iovec iov;
memcpy(buffer, "MESSAGE=", 8);
vsnprintf(buffer+8, sizeof(buffer) - 8, format, ap);
char_array_0(buffer);
zero(iov);
IOVEC_SET_STRING(iov, buffer);
return sd_journal_sendv(&iov, 1);
}
int sd_journal_send(const char *format, ...) {
int r, n = 0, i = 0, j;
va_list ap;
struct iovec *iov = NULL;
va_start(ap, format);
while (format) {
struct iovec *c;
char *buffer;
if (i >= n) {
n = MAX(i*2, 4);
c = realloc(iov, n * sizeof(struct iovec));
if (!c) {
r = -ENOMEM;
goto fail;
}
iov = c;
}
if (vasprintf(&buffer, format, ap) < 0) {
r = -ENOMEM;
goto fail;
}
IOVEC_SET_STRING(iov[i++], buffer);
format = va_arg(ap, char *);
}
va_end(ap);
r = sd_journal_sendv(iov, i);
fail:
for (j = 0; j < i; j++)
free(iov[j].iov_base);
free(iov);
return r;
}
int sd_journal_sendv(const struct iovec *iov, int n) {
int fd;
struct iovec *w;
uint64_t *l;
int i, j = 0;
struct msghdr mh;
struct sockaddr_un sa;
if (!iov || n <= 0)
return -EINVAL;
w = alloca(sizeof(struct iovec) * n * 5);
l = alloca(sizeof(uint64_t) * n);
for (i = 0; i < n; i++) {
char *c, *nl;
c = memchr(iov[i].iov_base, '=', iov[i].iov_len);
if (!c)
return -EINVAL;
nl = memchr(iov[i].iov_base, '\n', iov[i].iov_len);
if (nl) {
if (nl < c)
return -EINVAL;
/* Already includes a newline? Bummer, then
* let's write the variable name, then a
* newline, then the size (64bit LE), followed
* by the data and a final newline */
w[j].iov_base = iov[i].iov_base;
w[j].iov_len = c - (char*) iov[i].iov_base;
j++;
IOVEC_SET_STRING(w[j++], "\n");
l[i] = htole64(iov[i].iov_len - (c - (char*) iov[i].iov_base) - 1);
w[j].iov_base = &l[i];
w[j].iov_len = sizeof(uint64_t);
j++;
w[j].iov_base = c + 1;
w[j].iov_len = iov[i].iov_len - (c - (char*) iov[i].iov_base) - 1;
j++;
} else
/* Nothing special? Then just add the line and
* append a newline */
w[j++] = iov[i];
IOVEC_SET_STRING(w[j++], "\n");
}
fd = journal_fd();
if (fd < 0)
return fd;
zero(sa);
sa.sun_family = AF_UNIX;
strncpy(sa.sun_path,"/run/systemd/journal", sizeof(sa.sun_path));
zero(mh);
mh.msg_name = &sa;
mh.msg_namelen = offsetof(struct sockaddr_un, sun_path) + strlen(sa.sun_path);
mh.msg_iov = w;
mh.msg_iovlen = j;
if (sendmsg(fd, &mh, MSG_NOSIGNAL) < 0)
return -errno;
return 0;
}
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