build-sys: split internal basic/ library from shared/

basic/      can be used by everything
            cannot use anything outside of basic/

libsystemd/ can use basic/
            cannot use shared/

shared/     can use libsystemd/

1 files changed, 1138 insertions, 0 deletions

diff --git a/src/basic/log.c b/src/basic/log.c
new file mode 100644
index 0000000000..b96afc4de4
--- /dev/null
+++ b/src/basic/log.c
@@ -0,0 +1,1138 @@
+/*-*- 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 "sd-messages.h"
+#include "log.h"
+#include "util.h"
+#include "missing.h"
+#include "macro.h"
+#include "socket-util.h"
+#include "formats-util.h"
+#include "process-util.h"
+#include "terminal-util.h"
+#include "signal-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;
+
+static bool upgrade_syslog_to_journal = 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)
+                        safe_close(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) {
+        kmsg_fd = safe_close(kmsg_fd);
+}
+
+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) {
+        syslog_fd = safe_close(syslog_fd);
+}
+
+static int create_log_socket(int type) {
+        struct timeval tv;
+        int fd;
+
+        fd = socket(AF_UNIX, type|SOCK_CLOEXEC, 0);
+        if (fd < 0)
+                return -errno;
+
+        fd_inc_sndbuf(fd, SNDBUF_SIZE);
+
+        /* We need a blocking fd here since we'd otherwise lose
+        messages way too early. However, let's not hang forever in the
+        unlikely case of a deadlock. */
+        if (getpid() == 1)
+                timeval_store(&tv, 10 * USEC_PER_MSEC);
+        else
+                timeval_store(&tv, 10 * USEC_PER_SEC);
+        (void) setsockopt(fd, SOL_SOCKET, SO_SNDTIMEO, &tv, sizeof(tv));
+
+        return fd;
+}
+
+static int log_open_syslog(void) {
+
+        static const union sockaddr_union sa = {
+                .un.sun_family = AF_UNIX,
+                .un.sun_path = "/dev/log",
+        };
+
+        int r;
+
+        if (syslog_fd >= 0)
+                return 0;
+
+        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) {
+                safe_close(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) {
+        journal_fd = safe_close(journal_fd);
+}
+
+static int log_open_journal(void) {
+
+        static const union sockaddr_union sa = {
+                .un.sun_family = AF_UNIX,
+                .un.sun_path = "/run/systemd/journal/socket",
+        };
+
+        int r;
+
+        if (journal_fd >= 0)
+                return 0;
+
+        journal_fd = create_log_socket(SOCK_DGRAM);
+        if (journal_fd < 0) {
+                r = journal_fd;
+                goto fail;
+        }
+
+        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();
+
+        return log_open_console();
+}
+
+void log_set_target(LogTarget target) {
+        assert(target >= 0);
+        assert(target < _LOG_TARGET_MAX);
+
+        if (upgrade_syslog_to_journal) {
+                if (target == LOG_TARGET_SYSLOG)
+                        target = LOG_TARGET_JOURNAL;
+                else if (target == LOG_TARGET_SYSLOG_OR_KMSG)
+                        target = LOG_TARGET_JOURNAL_OR_KMSG;
+        }
+
+        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,
+                int error,
+                const char *file,
+                int line,
+                const char *func,
+                const char *object_field,
+                const char *object,
+                const char *buffer) {
+
+        char location[64], prefix[1 + DECIMAL_STR_MAX(int) + 2];
+        struct iovec iovec[6] = {};
+        unsigned n = 0;
+        bool highlight;
+
+        if (console_fd < 0)
+                return 0;
+
+        if (log_target == LOG_TARGET_CONSOLE_PREFIXED) {
+                sprintf(prefix, "<%i>", level);
+                IOVEC_SET_STRING(iovec[n++], prefix);
+        }
+
+        highlight = LOG_PRI(level) <= LOG_ERR && show_color;
+
+        if (show_location) {
+                snprintf(location, sizeof(location), "(%s:%i) ", file, line);
+                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) {
+
+                if (errno == EIO && getpid() == 1) {
+
+                        /* If somebody tried to kick us from our
+                         * console tty (via vhangup() or suchlike),
+                         * try to reconnect */
+
+                        log_close_console();
+                        log_open_console();
+
+                        if (console_fd < 0)
+                                return 0;
+
+                        if (writev(console_fd, iovec, n) < 0)
+                                return -errno;
+                } else
+                        return -errno;
+        }
+
+        return 1;
+}
+
+static int write_to_syslog(
+                int level,
+                int error,
+                const char *file,
+                int line,
+                const char *func,
+                const char *object_field,
+                const char *object,
+                const char *buffer) {
+
+        char header_priority[2 + DECIMAL_STR_MAX(int) + 1],
+             header_time[64],
+             header_pid[4 + DECIMAL_STR_MAX(pid_t) + 1];
+        struct iovec iovec[5] = {};
+        struct msghdr msghdr = {
+                .msg_iov = iovec,
+                .msg_iovlen = ELEMENTSOF(iovec),
+        };
+        time_t t;
+        struct tm *tm;
+
+        if (syslog_fd < 0)
+                return 0;
+
+        xsprintf(header_priority, "<%i>", level);
+
+        t = (time_t) (now(CLOCK_REALTIME) / USEC_PER_SEC);
+        tm = localtime(&t);
+        if (!tm)
+                return -EINVAL;
+
+        if (strftime(header_time, sizeof(header_time), "%h %e %T ", tm) <= 0)
+                return -EINVAL;
+
+        xsprintf(header_pid, "["PID_FMT"]: ", getpid());
+
+        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++;
+
+        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,
+                int error,
+                const char*file,
+                int line,
+                const char *func,
+                const char *object_field,
+                const char *object,
+                const char *buffer) {
+
+        char header_priority[2 + DECIMAL_STR_MAX(int) + 1],
+             header_pid[4 + DECIMAL_STR_MAX(pid_t) + 1];
+        struct iovec iovec[5] = {};
+
+        if (kmsg_fd < 0)
+                return 0;
+
+        xsprintf(header_priority, "<%i>", level);
+        xsprintf(header_pid, "["PID_FMT"]: ", getpid());
+
+        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 log_do_header(
+                char *header,
+                size_t size,
+                int level,
+                int error,
+                const char *file, int line, const char *func,
+                const char *object_field, const char *object) {
+
+        snprintf(header, size,
+                 "PRIORITY=%i\n"
+                 "SYSLOG_FACILITY=%i\n"
+                 "%s%s%s"
+                 "%s%.*i%s"
+                 "%s%s%s"
+                 "%s%.*i%s"
+                 "%s%s%s"
+                 "SYSLOG_IDENTIFIER=%s\n",
+                 LOG_PRI(level),
+                 LOG_FAC(level),
+                 isempty(file) ? "" : "CODE_FILE=",
+                 isempty(file) ? "" : file,
+                 isempty(file) ? "" : "\n",
+                 line ? "CODE_LINE=" : "",
+                 line ? 1 : 0, line, /* %.0d means no output too, special case for 0 */
+                 line ? "\n" : "",
+                 isempty(func) ? "" : "CODE_FUNCTION=",
+                 isempty(func) ? "" : func,
+                 isempty(func) ? "" : "\n",
+                 error ? "ERRNO=" : "",
+                 error ? 1 : 0, error,
+                 error ? "\n" : "",
+                 isempty(object) ? "" : object_field,
+                 isempty(object) ? "" : object,
+                 isempty(object) ? "" : "\n",
+                 program_invocation_short_name);
+
+        return 0;
+}
+
+static int write_to_journal(
+                int level,
+                int error,
+                const char*file,
+                int line,
+                const char *func,
+                const char *object_field,
+                const char *object,
+                const char *buffer) {
+
+        char header[LINE_MAX];
+        struct iovec iovec[4] = {};
+        struct msghdr mh = {};
+
+        if (journal_fd < 0)
+                return 0;
+
+        log_do_header(header, sizeof(header), level, error, file, line, func, object_field, object);
+
+        IOVEC_SET_STRING(iovec[0], header);
+        IOVEC_SET_STRING(iovec[1], "MESSAGE=");
+        IOVEC_SET_STRING(iovec[2], buffer);
+        IOVEC_SET_STRING(iovec[3], "\n");
+
+        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,
+                int error,
+                const char *file,
+                int line,
+                const char *func,
+                const char *object_field,
+                const char *object,
+                char *buffer) {
+
+        assert(buffer);
+
+        if (log_target == LOG_TARGET_NULL)
+                return -error;
+
+        /* Patch in LOG_DAEMON facility if necessary */
+        if ((level & LOG_FACMASK) == 0)
+                level = log_facility | LOG_PRI(level);
+
+        if (error < 0)
+                error = -error;
+
+        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, error, file, line, func, object_field, object, buffer);
+                        if (k < 0) {
+                                if (k != -EAGAIN)
+                                        log_close_journal();
+                                log_open_kmsg();
+                        }
+                }
+
+                if (log_target == LOG_TARGET_SYSLOG_OR_KMSG ||
+                    log_target == LOG_TARGET_SYSLOG) {
+
+                        k = write_to_syslog(level, error, file, line, func, object_field, object, buffer);
+                        if (k < 0) {
+                                if (k != -EAGAIN)
+                                        log_close_syslog();
+                                log_open_kmsg();
+                        }
+                }
+
+                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, error, file, line, func, object_field, object, buffer);
+                        if (k < 0) {
+                                log_close_kmsg();
+                                log_open_console();
+                        }
+                }
+
+                if (k <= 0)
+                        (void) write_to_console(level, error, file, line, func, object_field, object, buffer);
+
+                buffer = e;
+        } while (buffer);
+
+        return -error;
+}
+
+int log_dump_internal(
+        int level,
+        int error,
+        const char *file,
+        int line,
+        const char *func,
+        char *buffer) {
+
+        PROTECT_ERRNO;
+
+        /* This modifies the buffer... */
+
+        if (error < 0)
+                error = -error;
+
+        if (_likely_(LOG_PRI(level) > log_max_level))
+                return -error;
+
+        return log_dispatch(level, error, file, line, func, NULL, NULL, buffer);
+}
+
+int log_internalv(
+                int level,
+                int error,
+                const char*file,
+                int line,
+                const char *func,
+                const char *format,
+                va_list ap) {
+
+        PROTECT_ERRNO;
+        char buffer[LINE_MAX];
+
+        if (error < 0)
+                error = -error;
+
+        if (_likely_(LOG_PRI(level) > log_max_level))
+                return -error;
+
+        /* Make sure that %m maps to the specified error */
+        if (error != 0)
+                errno = error;
+
+        vsnprintf(buffer, sizeof(buffer), format, ap);
+
+        return log_dispatch(level, error, file, line, func, NULL, NULL, buffer);
+}
+
+int log_internal(
+                int level,
+                int error,
+                const char*file,
+                int line,
+                const char *func,
+                const char *format, ...) {
+
+        va_list ap;
+        int r;
+
+        va_start(ap, format);
+        r = log_internalv(level, error, file, line, func, format, ap);
+        va_end(ap);
+
+        return r;
+}
+
+int log_object_internalv(
+                int level,
+                int error,
+                const char*file,
+                int line,
+                const char *func,
+                const char *object_field,
+                const char *object,
+                const char *format,
+                va_list ap) {
+
+        PROTECT_ERRNO;
+        char *buffer, *b;
+        size_t l;
+
+        if (error < 0)
+                error = -error;
+
+        if (_likely_(LOG_PRI(level) > log_max_level))
+                return -error;
+
+        /* Make sure that %m maps to the specified error */
+        if (error != 0)
+                errno = error;
+
+        /* Prepend the object name before the message */
+        if (object) {
+                size_t n;
+
+                n = strlen(object);
+                l = n + 2 + LINE_MAX;
+
+                buffer = newa(char, l);
+                b = stpcpy(stpcpy(buffer, object), ": ");
+        } else {
+                l = LINE_MAX;
+                b = buffer = newa(char, l);
+        }
+
+        vsnprintf(b, l, format, ap);
+
+        return log_dispatch(level, error, file, line, func, object_field, object, buffer);
+}
+
+int log_object_internal(
+                int level,
+                int error,
+                const char*file,
+                int line,
+                const char *func,
+                const char *object_field,
+                const char *object,
+                const char *format, ...) {
+
+        va_list ap;
+        int r;
+
+        va_start(ap, format);
+        r = log_object_internalv(level, error, file, line, func, object_field, object, format, ap);
+        va_end(ap);
+
+        return r;
+}
+
+static void log_assert(
+                int level,
+                const char *text,
+                const char *file,
+                int line,
+                const char *func,
+                const char *format) {
+
+        static char buffer[LINE_MAX];
+
+        if (_likely_(LOG_PRI(level) > log_max_level))
+                return;
+
+        DISABLE_WARNING_FORMAT_NONLITERAL;
+        snprintf(buffer, sizeof(buffer), format, text, file, line, func);
+        REENABLE_WARNING;
+
+        log_abort_msg = buffer;
+
+        log_dispatch(level, 0, file, line, func, NULL, NULL, buffer);
+}
+
+noreturn void log_assert_failed(const char *text, const char *file, int line, const char *func) {
+        log_assert(LOG_CRIT, text, file, line, func, "Assertion '%s' failed at %s:%u, function %s(). Aborting.");
+        abort();
+}
+
+noreturn void log_assert_failed_unreachable(const char *text, const char *file, int line, const char *func) {
+        log_assert(LOG_CRIT, text, file, line, func, "Code should not be reached '%s' at %s:%u, function %s(). Aborting.");
+        abort();
+}
+
+void log_assert_failed_return(const char *text, const char *file, int line, const char *func) {
+        PROTECT_ERRNO;
+        log_assert(LOG_DEBUG, text, file, line, func, "Assertion '%s' failed at %s:%u, function %s(). Ignoring.");
+}
+
+int log_oom_internal(const char *file, int line, const char *func) {
+        log_internal(LOG_ERR, ENOMEM, file, line, func, "Out of memory.");
+        return -ENOMEM;
+}
+
+int log_struct_internal(
+                int level,
+                int error,
+                const char *file,
+                int line,
+                const char *func,
+                const char *format, ...) {
+
+        char buf[LINE_MAX];
+        bool found = false;
+        PROTECT_ERRNO;
+        va_list ap;
+
+        if (error < 0)
+                error = -error;
+
+        if (_likely_(LOG_PRI(level) > log_max_level))
+                return -error;
+
+        if (log_target == LOG_TARGET_NULL)
+                return -error;
+
+        if ((level & LOG_FACMASK) == 0)
+                level = log_facility | LOG_PRI(level);
+
+        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 = {
+                        .msg_iov = iovec,
+                };
+                static const char nl = '\n';
+                bool fallback = false;
+
+                /* If the journal is available do structured logging */
+                log_do_header(header, sizeof(header), level, error, file, line, func, NULL, NULL);
+                IOVEC_SET_STRING(iovec[n++], header);
+
+                va_start(ap, format);
+                while (format && n + 1 < ELEMENTSOF(iovec)) {
+                        va_list aq;
+                        char *m;
+
+                        /* We need to copy the va_list structure,
+                         * since vasprintf() leaves it afterwards at
+                         * an undefined location */
+
+                        if (error != 0)
+                                errno = error;
+
+                        va_copy(aq, ap);
+                        if (vasprintf(&m, format, aq) < 0) {
+                                va_end(aq);
+                                fallback = true;
+                                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++], m);
+
+                        iovec[n].iov_base = (char*) &nl;
+                        iovec[n].iov_len = 1;
+                        n++;
+
+                        format = va_arg(ap, char *);
+                }
+
+                mh.msg_iovlen = n;
+
+                (void) sendmsg(journal_fd, &mh, MSG_NOSIGNAL);
+
+        finish:
+                va_end(ap);
+                for (i = 1; i < n; i += 2)
+                        free(iovec[i].iov_base);
+
+                if (!fallback)
+                        return -error;
+        }
+
+        /* Fallback if journal logging is not available or didn't work. */
+
+        va_start(ap, format);
+        while (format) {
+                va_list aq;
+
+                if (error != 0)
+                        errno = error;
+
+                va_copy(aq, ap);
+                vsnprintf(buf, sizeof(buf), format, aq);
+                va_end(aq);
+
+                if (startswith(buf, "MESSAGE=")) {
+                        found = true;
+                        break;
+                }
+
+                VA_FORMAT_ADVANCE(format, ap);
+
+                format = va_arg(ap, char *);
+        }
+        va_end(ap);
+
+        if (!found)
+                return -error;
+
+        return log_dispatch(level, error, file, line, func, NULL, NULL, buf + 8);
+}
+
+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;
+}
+
+static int parse_proc_cmdline_item(const char *key, const char *value) {
+
+        /*
+         * The systemd.log_xyz= settings are parsed by all tools, and
+         * so is "debug".
+         *
+         * However, "quiet" is only parsed by PID 1, and only turns of
+         * status output to /dev/console, but does not alter the log
+         * level.
+         */
+
+        if (streq(key, "debug") && !value)
+                log_set_max_level(LOG_DEBUG);
+
+        else if (streq(key, "systemd.log_target") && value) {
+
+                if (log_set_target_from_string(value) < 0)
+                        log_warning("Failed to parse log target '%s'. Ignoring.", value);
+
+        } else if (streq(key, "systemd.log_level") && value) {
+
+                if (log_set_max_level_from_string(value) < 0)
+                        log_warning("Failed to parse log level '%s'. Ignoring.", value);
+
+        } else if (streq(key, "systemd.log_color") && value) {
+
+                if (log_show_color_from_string(value) < 0)
+                        log_warning("Failed to parse log color setting '%s'. Ignoring.", value);
+
+        } else if (streq(key, "systemd.log_location") && value) {
+
+                if (log_show_location_from_string(value) < 0)
+                        log_warning("Failed to parse log location setting '%s'. Ignoring.", value);
+        }
+
+        return 0;
+}
+
+void log_parse_environment(void) {
+        const char *e;
+
+        if (get_ctty_devnr(0, NULL) < 0)
+                /* Only try to read the command line in daemons.
+                   We assume that anything that has a controlling
+                   tty is user stuff. */
+                (void) parse_proc_cmdline(parse_proc_cmdline_item);
+
+        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;
+}
+
+bool log_get_show_color(void) {
+        return show_color;
+}
+
+void log_show_location(bool b) {
+        show_location = b;
+}
+
+bool log_get_show_location(void) {
+        return show_location;
+}
+
+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 ||
+            log_target == LOG_TARGET_CONSOLE_PREFIXED)
+                return true;
+
+        return syslog_fd < 0 && kmsg_fd < 0 && journal_fd < 0;
+}
+
+static const char *const log_target_table[_LOG_TARGET_MAX] = {
+        [LOG_TARGET_CONSOLE] = "console",
+        [LOG_TARGET_CONSOLE_PREFIXED] = "console-prefixed",
+        [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);
+
+void log_received_signal(int level, const struct signalfd_siginfo *si) {
+        if (si->ssi_pid > 0) {
+                _cleanup_free_ char *p = NULL;
+
+                get_process_comm(si->ssi_pid, &p);
+
+                log_full(level,
+                         "Received SIG%s from PID %"PRIu32" (%s).",
+                         signal_to_string(si->ssi_signo),
+                         si->ssi_pid, strna(p));
+        } else
+                log_full(level,
+                         "Received SIG%s.",
+                         signal_to_string(si->ssi_signo));
+
+}
+
+void log_set_upgrade_syslog_to_journal(bool b) {
+        upgrade_syslog_to_journal = b;
+}
+
+int log_syntax_internal(
+                const char *unit,
+                int level,
+                const char *config_file,
+                unsigned config_line,
+                int error,
+                const char *file,
+                int line,
+                const char *func,
+                const char *format, ...) {
+
+        PROTECT_ERRNO;
+        char buffer[LINE_MAX];
+        int r;
+        va_list ap;
+
+        if (error < 0)
+                error = -error;
+
+        if (_likely_(LOG_PRI(level) > log_max_level))
+                return -error;
+
+        if (log_target == LOG_TARGET_NULL)
+                return -error;
+
+        if (error != 0)
+                errno = error;
+
+        va_start(ap, format);
+        vsnprintf(buffer, sizeof(buffer), format, ap);
+        va_end(ap);
+
+        if (unit)
+                r = log_struct_internal(
+                                level, error,
+                                file, line, func,
+                                getpid() == 1 ? "UNIT=%s" : "USER_UNIT=%s", unit,
+                                LOG_MESSAGE_ID(SD_MESSAGE_INVALID_CONFIGURATION),
+                                "CONFIG_FILE=%s", config_file,
+                                "CONFIG_LINE=%u", config_line,
+                                LOG_MESSAGE("[%s:%u] %s", config_file, config_line, buffer),
+                                NULL);
+        else
+                r = log_struct_internal(
+                                level, error,
+                                file, line, func,
+                                LOG_MESSAGE_ID(SD_MESSAGE_INVALID_CONFIGURATION),
+                                "CONFIG_FILE=%s", config_file,
+                                "CONFIG_LINE=%u", config_line,
+                                LOG_MESSAGE("[%s:%u] %s", config_file, config_line, buffer),
+                                NULL);
+
+        return r;
+}