summaryrefslogtreecommitdiffstats
path: root/src/libsystemd/sd-journal/journal-send.c
diff options
context:
space:
mode:
Diffstat (limited to 'src/libsystemd/sd-journal/journal-send.c')
-rw-r--r--src/libsystemd/sd-journal/journal-send.c576
1 files changed, 576 insertions, 0 deletions
diff --git a/src/libsystemd/sd-journal/journal-send.c b/src/libsystemd/sd-journal/journal-send.c
new file mode 100644
index 0000000..be23b2f
--- /dev/null
+++ b/src/libsystemd/sd-journal/journal-send.c
@@ -0,0 +1,576 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <printf.h>
+#include <stddef.h>
+#include <sys/un.h>
+#include <unistd.h>
+#if HAVE_VALGRIND_VALGRIND_H
+# include <valgrind/valgrind.h>
+#endif
+
+#define SD_JOURNAL_SUPPRESS_LOCATION
+
+#include "sd-journal.h"
+
+#include "alloc-util.h"
+#include "errno-util.h"
+#include "fd-util.h"
+#include "fileio.h"
+#include "io-util.h"
+#include "iovec-util.h"
+#include "journal-send.h"
+#include "memfd-util.h"
+#include "missing_syscall.h"
+#include "process-util.h"
+#include "socket-util.h"
+#include "stdio-util.h"
+#include "string-util.h"
+#include "tmpfile-util.h"
+
+#define SNDBUF_SIZE (8*1024*1024)
+
+#define ALLOCA_CODE_FUNC(f, func) \
+ do { \
+ size_t _fl; \
+ const char *_func = (func); \
+ char **_f = &(f); \
+ _fl = strlen(_func) + 1; \
+ *_f = newa(char, _fl + 10); \
+ memcpy(*_f, "CODE_FUNC=", 10); \
+ memcpy(*_f + 10, _func, _fl); \
+ } while (false)
+
+/* 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 fd_plus_one = 0;
+
+static int journal_fd(void) {
+ int fd;
+
+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;
+
+ fd_inc_sndbuf(fd, SNDBUF_SIZE);
+
+ if (!__atomic_compare_exchange_n(&fd_plus_one, &(int){0}, fd+1,
+ false, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST)) {
+ safe_close(fd);
+ goto retry;
+ }
+
+ return fd;
+}
+
+int journal_fd_nonblock(bool nonblock) {
+ int r;
+
+ r = journal_fd();
+ if (r < 0)
+ return r;
+
+ return fd_nonblock(r, nonblock);
+}
+
+void close_journal_fd(void) {
+#if HAVE_VALGRIND_VALGRIND_H
+ /* Be nice to valgrind. This is not atomic, so it is useful mainly for debugging. */
+
+ if (!RUNNING_ON_VALGRIND)
+ return;
+
+ if (getpid_cached() != gettid())
+ return;
+
+ if (fd_plus_one <= 0)
+ return;
+
+ safe_close(fd_plus_one - 1);
+ fd_plus_one = 0;
+#endif
+}
+
+_public_ int sd_journal_print(int priority, const char *format, ...) {
+ int r;
+ va_list ap;
+
+ va_start(ap, format);
+ r = sd_journal_printv(priority, format, ap);
+ va_end(ap);
+
+ return r;
+}
+
+_public_ int sd_journal_printv(int priority, const char *format, va_list ap) {
+ char p[STRLEN("PRIORITY=") + DECIMAL_STR_MAX(int) + 1];
+ char sbuf[LINE_MAX + 8] = "MESSAGE=";
+ struct iovec iov[2];
+ int len;
+ va_list aq;
+ char *buffer = sbuf;
+
+ assert_return(priority >= 0, -EINVAL);
+ assert_return(priority <= 7, -EINVAL);
+ assert_return(format, -EINVAL);
+
+ xsprintf(p, "PRIORITY=%i", priority & LOG_PRIMASK);
+
+ va_copy(aq, ap);
+ len = vsnprintf(buffer + 8, LINE_MAX, format, aq);
+ va_end(aq);
+
+ if (len >= (int)LONG_LINE_MAX - 8)
+ return -ENOBUFS;
+
+ /* Allocate large buffer to accommodate big message */
+ if (len >= LINE_MAX) {
+ buffer = alloca_safe(len + 9);
+ memcpy(buffer, "MESSAGE=", 8);
+ assert_se(vsnprintf(buffer + 8, len + 1, format, ap) == len);
+ }
+
+ /* Strip trailing whitespace, keep prefix whitespace. */
+ (void) strstrip(buffer);
+
+ /* Suppress empty lines */
+ if (isempty(buffer + 8))
+ return 0;
+
+ iov[0] = IOVEC_MAKE_STRING(buffer);
+ iov[1] = IOVEC_MAKE_STRING(p);
+
+ return sd_journal_sendv(iov, 2);
+}
+
+_printf_(1, 0) static int fill_iovec_sprintf(
+ const char *format,
+ va_list ap,
+ size_t extra,
+ struct iovec **ret_iov,
+ size_t *ret_n_iov) {
+
+ PROTECT_ERRNO;
+ struct iovec *iov = NULL;
+ size_t n = 0;
+
+ assert(ret_iov);
+ assert(ret_n_iov);
+
+ if (extra > 0) {
+ if (!GREEDY_REALLOC0(iov, extra))
+ return -ENOMEM;
+
+ n = extra;
+ }
+
+ CLEANUP_ARRAY(iov, n, iovec_array_free);
+
+ while (format) {
+ _cleanup_free_ char *buffer = NULL;
+ va_list aq;
+
+ va_copy(aq, ap);
+ if (vasprintf(&buffer, format, aq) < 0) {
+ va_end(aq);
+ return -ENOMEM;
+ }
+ va_end(aq);
+
+ VA_FORMAT_ADVANCE(format, ap);
+ format = va_arg(ap, char *);
+
+ if (!GREEDY_REALLOC(iov, n + 1))
+ return -ENOMEM;
+
+ /* strip trailing whitespace, keep prefixing whitespace */
+ iov[n++] = IOVEC_MAKE_STRING(delete_trailing_chars(TAKE_PTR(buffer), NULL));
+ }
+
+ *ret_iov = TAKE_PTR(iov);
+ *ret_n_iov = n;
+ return 0;
+}
+
+_public_ int sd_journal_send(const char *format, ...) {
+ struct iovec *iov = NULL;
+ size_t n_iov = 0;
+ va_list ap;
+ int r;
+
+ CLEANUP_ARRAY(iov, n_iov, iovec_array_free);
+
+ va_start(ap, format);
+ r = fill_iovec_sprintf(format, ap, 0, &iov, &n_iov);
+ va_end(ap);
+ if (r < 0)
+ return r;
+
+ return sd_journal_sendv(iov, n_iov);
+}
+
+_public_ int sd_journal_sendv(const struct iovec *iov, int n) {
+ PROTECT_ERRNO;
+ int fd, r;
+ _cleanup_close_ int buffer_fd = -EBADF;
+ struct iovec *w;
+ uint64_t *l;
+ int i, j = 0;
+ static const union sockaddr_union sa = {
+ .un.sun_family = AF_UNIX,
+ .un.sun_path = "/run/systemd/journal/socket",
+ };
+ struct msghdr mh = {
+ .msg_name = (struct sockaddr*) &sa.sa,
+ .msg_namelen = SOCKADDR_UN_LEN(sa.un),
+ };
+ ssize_t k;
+ bool have_syslog_identifier = false;
+ bool seal = true;
+
+ assert_return(iov, -EINVAL);
+ assert_return(n > 0, -EINVAL);
+
+ w = newa(struct iovec, n * 5 + 3);
+ l = newa(uint64_t, n);
+
+ for (i = 0; i < n; i++) {
+ char *c, *nl;
+
+ if (_unlikely_(!iov[i].iov_base || iov[i].iov_len <= 1))
+ return -EINVAL;
+
+ c = memchr(iov[i].iov_base, '=', iov[i].iov_len);
+ if (_unlikely_(!c || c == iov[i].iov_base))
+ return -EINVAL;
+
+ have_syslog_identifier = have_syslog_identifier ||
+ (c == (char *) iov[i].iov_base + 17 &&
+ startswith(iov[i].iov_base, "SYSLOG_IDENTIFIER"));
+
+ nl = memchr(iov[i].iov_base, '\n', iov[i].iov_len);
+ if (nl) {
+ if (_unlikely_(nl < c))
+ return -EINVAL;
+
+ /* Already includes a newline? Bummer, then
+ * let's write the variable name, then a
+ * newline, then the size (64-bit LE), followed
+ * by the data and a final newline */
+
+ w[j++] = IOVEC_MAKE(iov[i].iov_base, c - (char*) iov[i].iov_base);
+ w[j++] = IOVEC_MAKE_STRING("\n");
+
+ l[i] = htole64(iov[i].iov_len - (c - (char*) iov[i].iov_base) - 1);
+ w[j++] = IOVEC_MAKE(&l[i], sizeof(uint64_t));
+
+ w[j++] = IOVEC_MAKE(c + 1, iov[i].iov_len - (c - (char*) iov[i].iov_base) - 1);
+ } else
+ /* Nothing special? Then just add the line and
+ * append a newline */
+ w[j++] = iov[i];
+
+ w[j++] = IOVEC_MAKE_STRING("\n");
+ }
+
+ if (!have_syslog_identifier &&
+ string_is_safe(program_invocation_short_name)) {
+
+ /* Implicitly add program_invocation_short_name, if it
+ * is not set explicitly. We only do this for
+ * program_invocation_short_name, and nothing else
+ * since everything else is much nicer to retrieve
+ * from the outside. */
+
+ w[j++] = IOVEC_MAKE_STRING("SYSLOG_IDENTIFIER=");
+ w[j++] = IOVEC_MAKE_STRING(program_invocation_short_name);
+ w[j++] = IOVEC_MAKE_STRING("\n");
+ }
+
+ fd = journal_fd();
+ if (_unlikely_(fd < 0))
+ return fd;
+
+ mh.msg_iov = w;
+ mh.msg_iovlen = j;
+
+ k = sendmsg(fd, &mh, MSG_NOSIGNAL);
+ if (k >= 0)
+ return 0;
+
+ /* Fail silently if the journal is not available */
+ if (errno == ENOENT)
+ return 0;
+
+ if (!IN_SET(errno, EMSGSIZE, ENOBUFS, EAGAIN))
+ return -errno;
+
+ /* Message doesn't fit... Let's dump the data in a memfd or
+ * temporary file and just pass a file descriptor of it to the
+ * other side.
+ *
+ * For the temporary files we use /dev/shm instead of /tmp
+ * here, since we want this to be a tmpfs, and one that is
+ * available from early boot on and where unprivileged users
+ * can create files. */
+ buffer_fd = memfd_new(NULL);
+ if (buffer_fd < 0) {
+ if (buffer_fd == -ENOSYS) {
+ buffer_fd = open_tmpfile_unlinkable("/dev/shm", O_RDWR | O_CLOEXEC);
+ if (buffer_fd < 0)
+ return buffer_fd;
+
+ seal = false;
+ } else
+ return buffer_fd;
+ }
+
+ n = writev(buffer_fd, w, j);
+ if (n < 0)
+ return -errno;
+
+ if (seal) {
+ r = memfd_set_sealed(buffer_fd);
+ if (r < 0)
+ return r;
+ }
+
+ r = send_one_fd_sa(fd, buffer_fd, mh.msg_name, mh.msg_namelen, 0);
+ if (r == -ENOENT)
+ /* Fail silently if the journal is not available */
+ return 0;
+ return r;
+}
+
+static int fill_iovec_perror_and_send(const char *message, int skip, struct iovec iov[]) {
+ PROTECT_ERRNO;
+ size_t n, k;
+
+ k = isempty(message) ? 0 : strlen(message) + 2;
+ n = 8 + k + 256 + 1;
+
+ for (;;) {
+ char buffer[n];
+ char* j;
+
+ errno = 0;
+ j = strerror_r(_saved_errno_, buffer + 8 + k, n - 8 - k);
+ if (errno == 0) {
+ char error[STRLEN("ERRNO=") + DECIMAL_STR_MAX(int) + 1];
+
+ if (j != buffer + 8 + k)
+ memmove(buffer + 8 + k, j, strlen(j)+1);
+
+ memcpy(buffer, "MESSAGE=", 8);
+
+ if (k > 0) {
+ memcpy(buffer + 8, message, k - 2);
+ memcpy(buffer + 8 + k - 2, ": ", 2);
+ }
+
+ xsprintf(error, "ERRNO=%i", _saved_errno_);
+
+ assert_cc(3 == LOG_ERR);
+ iov[skip+0] = IOVEC_MAKE_STRING("PRIORITY=3");
+ iov[skip+1] = IOVEC_MAKE_STRING(buffer);
+ iov[skip+2] = IOVEC_MAKE_STRING(error);
+
+ return sd_journal_sendv(iov, skip + 3);
+ }
+
+ if (errno != ERANGE)
+ return -errno;
+
+ n *= 2;
+ }
+}
+
+_public_ int sd_journal_perror(const char *message) {
+ struct iovec iovec[3];
+
+ return fill_iovec_perror_and_send(message, 0, iovec);
+}
+
+_public_ int sd_journal_stream_fd(const char *identifier, int priority, int level_prefix) {
+ _cleanup_close_ int fd = -EBADF;
+ char *header;
+ size_t l;
+ int r;
+
+ assert_return(priority >= 0, -EINVAL);
+ assert_return(priority <= 7, -EINVAL);
+
+ fd = socket(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC, 0);
+ if (fd < 0)
+ return -errno;
+
+ r = connect_unix_path(fd, AT_FDCWD, "/run/systemd/journal/stdout");
+ if (r < 0)
+ return r;
+
+ if (shutdown(fd, SHUT_RD) < 0)
+ return -errno;
+
+ (void) fd_inc_sndbuf(fd, SNDBUF_SIZE);
+
+ identifier = strempty(identifier);
+
+ l = strlen(identifier);
+ header = newa(char, l + 1 + 1 + 2 + 2 + 2 + 2 + 2);
+
+ memcpy(header, identifier, l);
+ header[l++] = '\n';
+ header[l++] = '\n'; /* unit id */
+ header[l++] = '0' + priority;
+ header[l++] = '\n';
+ header[l++] = '0' + !!level_prefix;
+ header[l++] = '\n';
+ header[l++] = '0';
+ header[l++] = '\n';
+ header[l++] = '0';
+ header[l++] = '\n';
+ header[l++] = '0';
+ header[l++] = '\n';
+
+ r = loop_write(fd, header, l);
+ if (r < 0)
+ return r;
+
+ return TAKE_FD(fd);
+}
+
+_public_ int sd_journal_print_with_location(int priority, const char *file, const char *line, const char *func, const char *format, ...) {
+ int r;
+ va_list ap;
+
+ va_start(ap, format);
+ r = sd_journal_printv_with_location(priority, file, line, func, format, ap);
+ va_end(ap);
+
+ return r;
+}
+
+_public_ int sd_journal_printv_with_location(int priority, const char *file, const char *line, const char *func, const char *format, va_list ap) {
+ char p[STRLEN("PRIORITY=") + DECIMAL_STR_MAX(int) + 1];
+ char sbuf[LINE_MAX + 8] = "MESSAGE=";
+ struct iovec iov[5];
+ char *f;
+ int len;
+ char *buffer = sbuf;
+ va_list aq;
+
+ assert_return(priority >= 0, -EINVAL);
+ assert_return(priority <= 7, -EINVAL);
+ assert_return(format, -EINVAL);
+
+ xsprintf(p, "PRIORITY=%i", priority & LOG_PRIMASK);
+
+ va_copy(aq, ap);
+ len = vsnprintf(buffer + 8, LINE_MAX, format, aq);
+ va_end(aq);
+
+ if (len >= (int)LONG_LINE_MAX - 8)
+ return -ENOBUFS;
+
+ /* Allocate large buffer to accommodate big message */
+ if (len >= LINE_MAX) {
+ buffer = alloca_safe(len + 9);
+ memcpy(buffer, "MESSAGE=", 8);
+ assert_se(vsnprintf(buffer + 8, len + 1, format, ap) == len);
+ }
+
+ /* Strip trailing whitespace, keep prefixing whitespace */
+ (void) strstrip(buffer);
+
+ /* Suppress empty lines */
+ if (isempty(buffer + 8))
+ return 0;
+
+ /* func is initialized from __func__ which is not a macro, but
+ * a static const char[], hence cannot easily be prefixed with
+ * CODE_FUNC=, hence let's do it manually here. */
+ ALLOCA_CODE_FUNC(f, func);
+
+ iov[0] = IOVEC_MAKE_STRING(buffer);
+ iov[1] = IOVEC_MAKE_STRING(p);
+ iov[2] = IOVEC_MAKE_STRING(file);
+ iov[3] = IOVEC_MAKE_STRING(line);
+ iov[4] = IOVEC_MAKE_STRING(f);
+
+ return sd_journal_sendv(iov, ELEMENTSOF(iov));
+}
+
+_public_ int sd_journal_send_with_location(const char *file, const char *line, const char *func, const char *format, ...) {
+ struct iovec *iov = NULL;
+ size_t n_iov = 0;
+ va_list ap;
+ char *f;
+ int r;
+
+ CLEANUP_ARRAY(iov, n_iov, iovec_array_free);
+
+ va_start(ap, format);
+ r = fill_iovec_sprintf(format, ap, 3, &iov, &n_iov);
+ va_end(ap);
+ if (r < 0)
+ return r;
+
+ ALLOCA_CODE_FUNC(f, func);
+
+ iov[0] = IOVEC_MAKE_STRING(file);
+ iov[1] = IOVEC_MAKE_STRING(line);
+ iov[2] = IOVEC_MAKE_STRING(f);
+
+ r = sd_journal_sendv(iov, n_iov);
+
+ iov[0] = iov[1] = iov[2] = (struct iovec) {};
+
+ return r;
+}
+
+_public_ int sd_journal_sendv_with_location(
+ const char *file, const char *line,
+ const char *func,
+ const struct iovec *iov, int n) {
+
+ struct iovec *niov;
+ char *f;
+
+ assert_return(iov, -EINVAL);
+ assert_return(n > 0, -EINVAL);
+
+ niov = newa(struct iovec, n + 3);
+ memcpy(niov, iov, sizeof(struct iovec) * n);
+
+ ALLOCA_CODE_FUNC(f, func);
+
+ niov[n++] = IOVEC_MAKE_STRING(file);
+ niov[n++] = IOVEC_MAKE_STRING(line);
+ niov[n++] = IOVEC_MAKE_STRING(f);
+
+ return sd_journal_sendv(niov, n);
+}
+
+_public_ int sd_journal_perror_with_location(
+ const char *file, const char *line,
+ const char *func,
+ const char *message) {
+
+ struct iovec iov[6];
+ char *f;
+
+ ALLOCA_CODE_FUNC(f, func);
+
+ iov[0] = IOVEC_MAKE_STRING(file);
+ iov[1] = IOVEC_MAKE_STRING(line);
+ iov[2] = IOVEC_MAKE_STRING(f);
+
+ return fill_iovec_perror_and_send(message, 3, iov);
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-09 14:38:46 +0000