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authorLennart Poettering <lennart@poettering.net>2011-12-17 00:56:34 +0100
committerLennart Poettering <lennart@poettering.net>2011-12-17 00:56:34 +0100
commit7f3e62571a63ac90de6ac5eefeeb8d3e9aa6f49e (patch)
treecf79b929ef42916d07227b76504fc5990bfe93e6 /src/journal/journal-send.c
parent1e2579fdeb7608719cb28da0b5061f48ba0efc34 (diff)
journal: add native protocol to journald, and client side API to send journal messages
Diffstat (limited to 'src/journal/journal-send.c')
-rw-r--r--src/journal/journal-send.c196
1 files changed, 196 insertions, 0 deletions
diff --git a/src/journal/journal-send.c b/src/journal/journal-send.c
new file mode 100644
index 0000000000..e2575a9805
--- /dev/null
+++ b/src/journal/journal-send.c
@@ -0,0 +1,196 @@
+/*-*- 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;
+}