src/udev/Makefile.am: work towards fixing up udev build

1 files changed, 885 insertions, 0 deletions

diff --git a/src/udev/log.c b/src/udev/log.c
new file mode 100644
index 0000000000..63578683ab
--- /dev/null
+++ b/src/udev/log.c
@@ -0,0 +1,885 @@
+/*-*- 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 <printf.h>
+
+#include "log.h"
+#include "util.h"
+#include "missing.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)
+                        return console_fd;
+        } 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)
+                return -errno;
+
+        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;
+
+        return 0;
+
+fail:
+        log_close_syslog();
+        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;
+        }
+
+        return 0;
+
+fail:
+        log_close_journal();
+        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 && log_target != LOG_TARGET_SAFE) ||
+            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_SAFE ||
+                    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"
+                 "SYSLOG_IDENTIFIER=%s\n"
+                 "MESSAGE=",
+                 LOG_PRI(level),
+                 LOG_FAC(level),
+                 file,
+                 line,
+                 func,
+                 program_invocation_short_name);
+
+        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_SAFE ||
+                     log_target == LOG_TARGET_SYSLOG_OR_KMSG ||
+                     log_target == LOG_TARGET_JOURNAL_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_oom_internal(const char *file, int line, const char *func) {
+        log_meta(LOG_ERR, file, line, func, "Out of memory.");
+        return -ENOMEM;
+}
+
+int log_struct_internal(
+                int level,
+                const char *file,
+                int line,
+                const char *func,
+                const char *format, ...) {
+
+        int saved_errno;
+        va_list ap;
+        int r;
+
+        if (_likely_(LOG_PRI(level) > log_max_level))
+                return 0;
+
+        if (log_target == LOG_TARGET_NULL)
+                return 0;
+
+        if ((level & LOG_FACMASK) == 0)
+                level = log_facility | LOG_PRI(level);
+
+        saved_errno = errno;
+
+        if ((log_target == LOG_TARGET_AUTO ||
+             log_target == LOG_TARGET_JOURNAL_OR_KMSG ||
+             log_target == LOG_TARGET_JOURNAL) &&
+            journal_fd >= 0) {
+
+                char header[LINE_MAX];
+                struct iovec iovec[17];
+                unsigned n = 0, i;
+                struct msghdr mh;
+                const char nl = '\n';
+
+                /* If the journal is available do structured logging */
+
+                snprintf(header, sizeof(header),
+                        "PRIORITY=%i\n"
+                        "SYSLOG_FACILITY=%i\n"
+                        "CODE_FILE=%s\n"
+                        "CODE_LINE=%i\n"
+                        "CODE_FUNCTION=%s\n"
+                        "SYSLOG_IDENTIFIER=%s\n",
+                        LOG_PRI(level),
+                        LOG_FAC(level),
+                        file,
+                        line,
+                        func,
+                        program_invocation_short_name);
+                char_array_0(header);
+
+                zero(iovec);
+                IOVEC_SET_STRING(iovec[n++], header);
+
+                va_start(ap, format);
+                while (format && n + 1 < ELEMENTSOF(iovec)) {
+                        char *buf;
+                        va_list aq;
+
+                        /* We need to copy the va_list structure,
+                         * since vasprintf() leaves it afterwards at
+                         * an undefined location */
+
+                        va_copy(aq, ap);
+                        if (vasprintf(&buf, format, aq) < 0) {
+                                va_end(aq);
+                                r = -ENOMEM;
+                                goto finish;
+                        }
+                        va_end(aq);
+
+                        /* Now, jump enough ahead, so that we point to
+                         * the next format string */
+                        VA_FORMAT_ADVANCE(format, ap);
+
+                        IOVEC_SET_STRING(iovec[n++], buf);
+
+                        iovec[n].iov_base = (char*) &nl;
+                        iovec[n].iov_len = 1;
+                        n++;
+
+                        format = va_arg(ap, char *);
+                }
+
+                zero(mh);
+                mh.msg_iov = iovec;
+                mh.msg_iovlen = n;
+
+                if (sendmsg(journal_fd, &mh, MSG_NOSIGNAL) < 0)
+                        r = -errno;
+                else
+                        r = 1;
+
+        finish:
+                va_end(ap);
+                for (i = 1; i < n; i += 2)
+                        free(iovec[i].iov_base);
+
+        } else {
+                char buf[LINE_MAX];
+                bool found = false;
+
+                /* Fallback if journal logging is not available */
+
+                va_start(ap, format);
+                while (format) {
+                        va_list aq;
+
+                        va_copy(aq, ap);
+                        vsnprintf(buf, sizeof(buf), format, aq);
+                        va_end(aq);
+                        char_array_0(buf);
+
+                        if (startswith(buf, "MESSAGE=")) {
+                                found = true;
+                                break;
+                        }
+
+                        VA_FORMAT_ADVANCE(format, ap);
+
+                        format = va_arg(ap, char *);
+                }
+                va_end(ap);
+
+                if (found)
+                        r = log_dispatch(level, file, line, func, buf + 8);
+                else
+                        r = -EINVAL;
+        }
+
+        errno = saved_errno;
+        return r;
+}
+
+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;
+
+        e = secure_getenv("SYSTEMD_LOG_TARGET");
+        if (e && log_set_target_from_string(e) < 0)
+                log_warning("Failed to parse log target %s. Ignoring.", e);
+
+        e = secure_getenv("SYSTEMD_LOG_LEVEL");
+        if (e && log_set_max_level_from_string(e) < 0)
+                log_warning("Failed to parse log level %s. Ignoring.", e);
+
+        e = secure_getenv("SYSTEMD_LOG_COLOR");
+        if (e && log_show_color_from_string(e) < 0)
+                log_warning("Failed to parse bool %s. Ignoring.", e);
+
+        e = secure_getenv("SYSTEMD_LOG_LOCATION");
+        if (e && 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;
+}
+
+bool log_on_console(void) {
+        if (log_target == LOG_TARGET_CONSOLE)
+                return true;
+
+        return syslog_fd < 0 && kmsg_fd < 0 && journal_fd < 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_SAFE] = "safe",
+        [LOG_TARGET_NULL] = "null"
+};
+
+DEFINE_STRING_TABLE_LOOKUP(log_target, LogTarget);