src/lib/failures.c

	failures.c revision 7fb80bfee23825f544a2c22717da14f7b162a6d2
/* Copyright (c) 2002-2007 Dovecot authors, see the included COPYING file */

#include "lib.h"
#include "ioloop.h"
#include "str.h"
#include "backtrace-string.h"
#include "printf-format-fix.h"
#include "write-full.h"
#include "fd-close-on-exec.h"

#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <syslog.h>
#include <time.h>

static const char *log_type_prefixes[] = {
    "Info: ",
    "Warning: ",
    "Error: ",
    "Fatal: ",
    "Panic: "
};
static char log_type_internal_chars[] = {
    'I', 'W', 'E', 'F', 'P'
};

static void failure_exit(int status) ATTR_NORETURN;

static void default_fatal_handler(enum log_type type, int status,
                  const char *format, va_list args)
    ATTR_NORETURN ATTR_FORMAT(3, 0);
static void default_error_handler(enum log_type type, const char *format,
                  va_list args) ATTR_FORMAT(2, 0);

/* Initialize working defaults */
static fatal_failure_callback_t *fatal_handler ATTR_NORETURN =
    default_fatal_handler;
static failure_callback_t *error_handler = default_error_handler;
static failure_callback_t *info_handler = default_error_handler;
static void (*failure_exit_callback)(int *) = NULL;

static int log_fd = STDERR_FILENO, log_info_fd = STDERR_FILENO;
static char *log_prefix = NULL, *log_stamp_format = NULL;

/* kludgy .. we want to trust log_stamp_format with -Wformat-nonliteral */
static const char *get_log_stamp_format(const char *unused)
    ATTR_FORMAT_ARG(1);

static const char *get_log_stamp_format(const char *unused ATTR_UNUSED)
{
    return log_stamp_format;
}

static void failure_exit(int status)
{
    if (failure_exit_callback != NULL)
        failure_exit_callback(&status);
    exit(status);
}

static void log_prefix_add(string_t *str)
{
    struct tm *tm;
    char buf[256];
    time_t now;

    if (log_prefix != NULL)
        str_append(str, log_prefix);

    if (log_stamp_format != NULL) {
        now = time(NULL);
        tm = localtime(&now);

        if (strftime(buf, sizeof(buf),
                 get_log_stamp_format("unused"), tm) > 0)
            str_append(str, buf);
    }
}

static void log_fd_flush_stop(struct ioloop *ioloop)
{
    io_loop_stop(ioloop);
}

static int log_fd_write(int fd, const unsigned char *data, unsigned int len)
{
    struct ioloop *ioloop;
    struct io *io;
    ssize_t ret;

    while ((ret = write(fd, data, len)) != len) {
        if (ret > 0) {
            /* some was written, continue.. */
            data += ret;
            len -= ret;
            continue;
        }
        if (ret == 0) {
            /* out of disk space? */
            return -1;
        }
        if (errno != EAGAIN)
            return -1;

        /* wait until we can write more. this can happen at least
           when writing to terminal, even if fd is blocking. */
        ioloop = io_loop_create();
        io = io_add(IO_WRITE, fd, log_fd_flush_stop, ioloop);
        io_loop_run(ioloop);
        io_remove(&io);
        io_loop_destroy(&ioloop);
    }
    return 0;
}

static int ATTR_FORMAT(3, 0)
default_handler(const char *prefix, int fd, const char *format, va_list args)
{
    static int recursed = 0;
    string_t *str;
    int ret, old_errno = errno;

    if (recursed >= 2) {
        /* we're being called from some signal handler or we ran
           out of memory */
        return 0;
    }

    recursed++;

    t_push();
    str = t_str_new(256);
    log_prefix_add(str);
    str_append(str, prefix);

    /* make sure there's no %n in there and fix %m */
    str_vprintfa(str, printf_format_fix(format), args);
    str_append_c(str, '\n');

    ret = log_fd_write(fd, str_data(str), str_len(str));
    t_pop();

    errno = old_errno;
    recursed--;

    return ret;
}

static void ATTR_FORMAT(3, 0)
default_fatal_handler(enum log_type type, int status,
              const char *format, va_list args)
{
    const char *backtrace;

    if (default_handler(log_type_prefixes[type], log_fd, format,
                args) < 0 && status == FATAL_DEFAULT)
        status = FATAL_LOGWRITE;

    if (type == LOG_TYPE_PANIC) {
        if (backtrace_get(&backtrace) == 0)
            i_error("Raw backtrace: %s", backtrace);
    }

    if (type == LOG_TYPE_PANIC)
        abort();
    else
        failure_exit(status);
}

static void ATTR_FORMAT(2, 0)
default_error_handler(enum log_type type, const char *format, va_list args)
{
    int fd = type == LOG_TYPE_INFO ? log_info_fd : log_fd;

    if (default_handler(log_type_prefixes[type], fd, format, args) < 0)
        failure_exit(FATAL_LOGWRITE);
}

void i_log_type(enum log_type type, const char *format, ...)
{
    va_list args;

    va_start(args, format);
    if (type == LOG_TYPE_INFO)
        info_handler(type, format, args);
    else
        error_handler(type, format, args);
    va_end(args);
}

void i_panic(const char *format, ...)
{
    va_list args;

    va_start(args, format);
    fatal_handler(LOG_TYPE_PANIC, 0, format, args);
    va_end(args);
}

void i_fatal(const char *format, ...)
{
    va_list args;

    va_start(args, format);
    fatal_handler(LOG_TYPE_FATAL, FATAL_DEFAULT, format, args);
    va_end(args);
}

void i_fatal_status(int status, const char *format, ...)
{
    va_list args;

    va_start(args, format);
    fatal_handler(LOG_TYPE_FATAL, status, format, args);
    va_end(args);
}

void i_error(const char *format, ...)
{
    int old_errno = errno;
    va_list args;

    va_start(args, format);
    error_handler(LOG_TYPE_ERROR, format, args);
    va_end(args);

    errno = old_errno;
}

void i_warning(const char *format, ...)
{
    int old_errno = errno;
    va_list args;

    va_start(args, format);
    error_handler(LOG_TYPE_WARNING, format, args);
    va_end(args);

    errno = old_errno;
}

void i_info(const char *format, ...)
{
    int old_errno = errno;
    va_list args;

    va_start(args, format);
    info_handler(LOG_TYPE_INFO, format, args);
    va_end(args);

    errno = old_errno;
}

void i_set_fatal_handler(fatal_failure_callback_t *callback ATTR_NORETURN)
{
    if (callback == NULL)
        callback = default_fatal_handler;
        fatal_handler = callback;
}

void i_set_error_handler(failure_callback_t *callback)
{
    if (callback == NULL)
        callback = default_error_handler;
    error_handler = callback;
}

void i_set_info_handler(failure_callback_t *callback)
{
    if (callback == NULL)
        callback = default_error_handler;
    info_handler = callback;
}

static int ATTR_FORMAT(2, 0)
syslog_handler(int level, const char *format, va_list args)
{
    static int recursed = 0;

    if (recursed != 0)
        return -1;

    recursed++;

    /* make sure there's no %n in there. vsyslog() supports %m, but since
       we'll convert it ourself anyway, we might as well it */
    vsyslog(level, printf_format_fix_unsafe(format), args);
    recursed--;

    return 0;
}

void i_syslog_fatal_handler(enum log_type type, int status,
                const char *fmt, va_list args)
{
    const char *backtrace;
    if (syslog_handler(LOG_CRIT, fmt, args) < 0 && status == FATAL_DEFAULT)
        status = FATAL_LOGERROR;

    if (type == LOG_TYPE_PANIC) {
        if (backtrace_get(&backtrace) == 0)
            i_error("Raw backtrace: %s", backtrace);
        abort();
    } else {
        failure_exit(status);
    }
}

void i_syslog_error_handler(enum log_type type, const char *fmt, va_list args)
{
    int level = LOG_ERR;

    switch (type) {
    case LOG_TYPE_INFO:
        level = LOG_INFO;
        break;
    case LOG_TYPE_WARNING:
        level = LOG_WARNING;
        break;
    case LOG_TYPE_ERROR:
        level = LOG_ERR;
        break;
    case LOG_TYPE_FATAL:
    case LOG_TYPE_PANIC:
        level = LOG_CRIT;
        break;
    }

    if (syslog_handler(level, fmt, args) < 0)
        failure_exit(FATAL_LOGERROR);
}

void i_set_failure_syslog(const char *ident, int options, int facility)
{
    openlog(ident, options, facility);

    i_set_fatal_handler(i_syslog_fatal_handler);
    i_set_error_handler(i_syslog_error_handler);
    i_set_info_handler(i_syslog_error_handler);
}

static void open_log_file(int *fd, const char *path)
{
    char buf[PATH_MAX];

    if (*fd != STDERR_FILENO) {
        if (close(*fd) < 0) {
            i_snprintf(buf, sizeof(buf),
                   "close(%d) failed: %m", *fd);
            (void)write_full(STDERR_FILENO, buf, strlen(buf));
        }
    }

    if (path == NULL || strcmp(path, "/dev/stderr") == 0)
        *fd = STDERR_FILENO;
    else {
        *fd = open(path, O_CREAT | O_APPEND | O_WRONLY, 0600);
        if (*fd == -1) {
            *fd = STDERR_FILENO;
            i_snprintf(buf, sizeof(buf),
                   "Can't open log file %s: %m", path);
            (void)write_full(STDERR_FILENO, buf, strlen(buf));
            failure_exit(FATAL_LOGOPEN);
        }
        fd_close_on_exec(*fd, TRUE);
    }
}

void i_set_failure_file(const char *path, const char *prefix)
{
    i_set_failure_prefix(prefix);

    if (log_info_fd != STDERR_FILENO && log_info_fd != log_fd) {
        if (close(log_info_fd) < 0)
            i_error("close(%d) failed: %m", log_info_fd);
    }

    open_log_file(&log_fd, path);
    log_info_fd = log_fd;

    i_set_fatal_handler(NULL);
    i_set_error_handler(NULL);
    i_set_info_handler(NULL);
}

void i_set_failure_prefix(const char *prefix)
{
    i_free(log_prefix);
    log_prefix = i_strdup(prefix);
}

static int ATTR_FORMAT(2, 0)
internal_handler(char log_type, const char *format, va_list args)
{
    string_t *str;
    int ret;

    t_push();
    str = t_str_new(512);
    str_append_c(str, 1);
    str_append_c(str, log_type);
    str_vprintfa(str, format, args);
    str_append_c(str, '\n');
    ret = write_full(2, str_data(str), str_len(str));
    t_pop();

    return ret;
}

static void ATTR_NORETURN ATTR_FORMAT(3, 0)
i_internal_fatal_handler(enum log_type type, int status,
             const char *fmt, va_list args)
{
    const char *backtrace;

    if (internal_handler(log_type_internal_chars[type], fmt, args) < 0 &&
        status == FATAL_DEFAULT)
        status = FATAL_LOGERROR;

    if (type == LOG_TYPE_PANIC) {
        if (backtrace_get(&backtrace) == 0)
            i_error("Raw backtrace: %s", backtrace);
        abort();
    } else {
        failure_exit(status);
    }
}

static void ATTR_FORMAT(2, 0)
i_internal_error_handler(enum log_type type, const char *fmt, va_list args)
{
    if (internal_handler(log_type_internal_chars[type], fmt, args) < 0)
        failure_exit(FATAL_LOGERROR);
}

void i_set_failure_internal(void)
{
    i_set_fatal_handler(i_internal_fatal_handler);
    i_set_error_handler(i_internal_error_handler);
    i_set_info_handler(i_internal_error_handler);
}

void i_set_info_file(const char *path)
{
    if (log_info_fd == log_fd)
        log_info_fd = STDERR_FILENO;

    open_log_file(&log_info_fd, path);
        info_handler = default_error_handler;
}

void i_set_failure_timestamp_format(const char *fmt)
{
    i_free(log_stamp_format);
        log_stamp_format = i_strdup(fmt);
}

void i_set_failure_exit_callback(void (*callback)(int *status))
{
    failure_exit_callback = callback;
}

void failures_deinit(void)
{
    if (log_info_fd == log_fd)
        log_info_fd = STDERR_FILENO;

    if (log_fd != STDERR_FILENO) {
        (void)close(log_fd);
        log_fd = STDERR_FILENO;
    }

    if (log_info_fd != STDERR_FILENO) {
        (void)close(log_info_fd);
        log_info_fd = STDERR_FILENO;
    }

    i_free_and_null(log_prefix);
    i_free_and_null(log_stamp_format);
}