src/shared: refactor shared code

Signed-off-by: Anthony G. Basile <blueness@gentoo.org>

1 files changed, 579 insertions, 0 deletions

diff --git a/src/shared/log.c b/src/shared/log.c
new file mode 100644
index 0000000000..cd496cf6c5
--- /dev/null
+++ b/src/shared/log.c
@@ -0,0 +1,579 @@
+/*-*- 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 <string.h>
+
+#include "log.h"
+#include "time-util.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 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;
+
+        fd = socket(AF_UNIX, type|SOCK_CLOEXEC, 0);
+        if (fd < 0)
+                return -errno;
+
+        fd_inc_sndbuf(fd, SNDBUF_SIZE);
+
+        return fd;
+}
+
+static int log_open_syslog(void) {
+        int r;
+        union sockaddr_union sa = {
+                .un.sun_family = AF_UNIX,
+                .un.sun_path = "/dev/log",
+        };
+
+        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) {
+                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;
+}
+
+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_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)
+                    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_console();
+                                return r;
+                        }
+                }
+
+                if (log_target == LOG_TARGET_AUTO ||
+                    log_target == LOG_TARGET_SAFE ||
+                    log_target == LOG_TARGET_SYSLOG_OR_KMSG ||
+                    log_target == LOG_TARGET_KMSG) {
+                        r = log_open_kmsg();
+                        if (r >= 0) {
+                                log_close_syslog();
+                                log_close_console();
+                                return r;
+                        }
+                }
+        }
+
+        log_close_syslog();
+
+        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_syslog();
+        log_close_kmsg();
+        log_close_console();
+}
+
+void log_set_max_level(int level) {
+        assert((level & LOG_PRIMASK) == level);
+
+        log_max_level = level;
+}
+
+static int write_to_console(
+                int level,
+                const char*file,
+                int line,
+                const char *func,
+                const char *object_name,
+                const char *object,
+                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;
+
+        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) {
+
+                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,
+        const char*file,
+        int line,
+        const char *func,
+        const char *object_name,
+        const char *object,
+        const char *buffer) {
+
+        char header_priority[16], header_time[64], header_pid[16];
+        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;
+
+        snprintf(header_priority, sizeof(header_priority), "<%i>", level);
+        char_array_0(header_priority);
+
+        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;
+
+        snprintf(header_pid, sizeof(header_pid), "["PID_FMT"]: ", getpid());
+        char_array_0(header_pid);
+
+        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,
+        const char*file,
+        int line,
+        const char *func,
+        const char *object_name,
+        const char *object,
+        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), "["PID_FMT"]: ", getpid());
+        char_array_0(header_pid);
+
+        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,
+                         const char *file, int line, const char *func,
+                         const char *object_name, const char *object) {
+        snprintf(header, size,
+                 "PRIORITY=%i\n"
+                 "SYSLOG_FACILITY=%i\n"
+                 "%s%.*s%s"
+                 "%s%.*i%s"
+                 "%s%.*s%s"
+                 "%s%.*s%s"
+                 "SYSLOG_IDENTIFIER=%s\n",
+                 LOG_PRI(level),
+                 LOG_FAC(level),
+                 file ? "CODE_FILE=" : "",
+                 file ? LINE_MAX : 0, file, /* %.0s means no output */
+                 file ? "\n" : "",
+                 line ? "CODE_LINE=" : "",
+                 line ? 1 : 0, line, /* %.0d means no output too, special case for 0 */
+                 line ? "\n" : "",
+                 func ? "CODE_FUNCTION=" : "",
+                 func ? LINE_MAX : 0, func,
+                 func ? "\n" : "",
+                 object ? object_name : "",
+                 object ? LINE_MAX : 0, object, /* %.0s means no output */
+                 object ? "\n" : "",
+                 program_invocation_short_name);
+        header[size - 1] = '\0';
+        return 0;
+}
+
+static int log_dispatch(
+        int level,
+        const char*file,
+        int line,
+        const char *func,
+        const char *object_name,
+        const char *object,
+        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_open_kmsg();
+
+                if (log_target == LOG_TARGET_SYSLOG_OR_KMSG ||
+                    log_target == LOG_TARGET_SYSLOG) {
+
+                        k = write_to_syslog(level, file, line, func,
+                                            object_name, object, 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_KMSG)) {
+
+                        k = write_to_kmsg(level, file, line, func,
+                                          object_name, object, 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,
+                                             object_name, object, buffer);
+                        if (k < 0)
+                                return k;
+                }
+
+                buffer = e;
+        } while (buffer);
+
+        return r;
+}
+
+int log_metav(
+        int level,
+        const char*file,
+        int line,
+        const char *func,
+        const char *format,
+        va_list ap) {
+
+        PROTECT_ERRNO;
+        char buffer[LINE_MAX];
+
+        if (_likely_(LOG_PRI(level) > log_max_level))
+                return 0;
+
+        vsnprintf(buffer, sizeof(buffer), format, ap);
+        char_array_0(buffer);
+
+        return log_dispatch(level, file, line, func, NULL, NULL, buffer);
+}
+
+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;
+}
+
+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;
+
+        char_array_0(buffer);
+        log_abort_msg = buffer;
+
+        log_dispatch(level, 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();
+}
+
+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_get_max_level(void) {
+        return log_max_level;
+}
+static const char *const log_target_table[] = {
+        [LOG_TARGET_CONSOLE] = "console",
+        [LOG_TARGET_KMSG] = "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);