src/lib/failures.c

	failures.c revision 091e7843d8a607483f5252d2f44bb0c7dc81c583
/* Copyright (c) 2002-2003 Timo Sirainen */

#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 <stdio.h>
#include <stdlib.h>
#include <syslog.h>
#include <time.h>

static void failure_exit(int status) __attr_noreturn__;

static void default_panic_handler(const char *format, va_list args)
    __attr_noreturn__ __attr_format__(1, 0);
static void default_fatal_handler(int status, const char *format, va_list args)
    __attr_noreturn__ __attr_format__(2, 0);

static void default_error_handler(const char *format, va_list args)
    __attr_format__(1, 0);
static void default_warning_handler(const char *format, va_list args)
    __attr_format__(1, 0);
static void default_info_handler(const char *format, va_list args)
    __attr_format__(1, 0);

/* Initialize working defaults */
static failure_callback_t *panic_handler __attr_noreturn__ =
    default_panic_handler;
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 *warning_handler = default_warning_handler;
static failure_callback_t *info_handler = default_info_handler;
static void (*failure_exit_callback)(int *) = NULL;

static FILE *log_fd = NULL, *log_info_fd = NULL;
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 write_prefix(FILE *f)
{
    struct tm *tm;
    char str[256];
    time_t now;

    if (log_prefix != NULL)
        fputs(log_prefix, f);

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

        if (strftime(str, sizeof(str),
                 get_log_stamp_format("unused"), tm) > 0)
            fputs(str, f);
    }
}

static int __attr_format__(3, 0)
default_handler(const char *prefix, FILE *f, const char *format, va_list args)
{
    static int recursed = 0;
    va_list args2;
    int old_errno = errno;

    if (recursed == 2) {
        /* we're being called from some signal handler, or
           printf_format_fix_unsafe() killed us again */
        return -1;
    }

    recursed++;

    if (f == NULL) {
        f = stderr;

        if (log_fd == NULL)
            log_fd = stderr;
    }

    VA_COPY(args2, args);

    if (recursed == 2) {
        /* printf_format_fix_unsafe() probably killed us last time,
           just write the format now. */

        fputs("recursed: ", f);
        fputs(format, f);
    } else {
        write_prefix(f);
        fputs(prefix, f);

        /* write may have failed, restore errno so %m works. although
           it probably can't write the error then anyway. */
        errno = old_errno;

        /* make sure there's no %n in there and fix %m */
        vfprintf(f, printf_format_fix_unsafe(format), args2);
    }

    fputc('\n', f);

    errno = old_errno;
    recursed--;

    return 0;
}

static void __attr_format__(1, 0)
default_panic_handler(const char *format, va_list args)
{
    const char *backtrace;

    (void)default_handler("Panic: ", log_fd, format, args);
    if (backtrace_get(&backtrace) == 0)
        i_error("Raw backtrace: %s", backtrace);
    abort();
}

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

static int log_fd_flush(FILE *fd)
{
    struct ioloop *ioloop;
    struct io *io;

    while (fflush(fd) < 0) {
        if (errno == EINTR)
            continue;
        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, fileno(log_fd),
                log_fd_flush_stop, ioloop);
        io_loop_run(ioloop);
        io_remove(&io);
        io_loop_destroy(&ioloop);
    }
    return 0;
}

static void __attr_format__(2, 0)
default_fatal_handler(int status, const char *format, va_list args)
{
    if (default_handler("Fatal: ", log_fd, format, args) < 0 &&
        status == FATAL_DEFAULT)
        status = FATAL_LOGERROR;

    if (log_fd_flush(log_fd) < 0 && status == FATAL_DEFAULT)
        status = FATAL_LOGWRITE;

    failure_exit(status);
}

static void __attr_format__(1, 0)
default_error_handler(const char *format, va_list args)
{
    if (default_handler("Error: ", log_fd, format, args) < 0)
        failure_exit(FATAL_LOGERROR);

    if (log_fd_flush(log_fd) < 0)
        failure_exit(FATAL_LOGWRITE);
}

static void __attr_format__(1, 0)
default_warning_handler(const char *format, va_list args)
{
    (void)default_handler("Warning: ", log_fd, format, args);

    if (log_fd_flush(log_fd) < 0)
        failure_exit(FATAL_LOGWRITE);
}

static void __attr_format__(1, 0)
default_info_handler(const char *format, va_list args)
{
    (void)default_handler("Info: ", log_info_fd, format, args);

    if (log_fd_flush(log_info_fd) < 0)
        failure_exit(FATAL_LOGWRITE);
}

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

    va_start(args, format);
    panic_handler(format, args);
    va_end(args);
}

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

    va_start(args, format);
    fatal_handler(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(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(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);
    warning_handler(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(format, args);
    va_end(args);

    errno = old_errno;
}

void i_set_panic_handler(failure_callback_t *callback __attr_noreturn__)
{
    if (callback == NULL)
        callback = default_panic_handler;
        panic_handler = callback;
}

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_warning_handler(failure_callback_t *callback)
{
    if (callback == NULL)
        callback = default_warning_handler;
        warning_handler = callback;
}

void i_set_info_handler(failure_callback_t *callback)
{
    if (callback == NULL)
        callback = default_info_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_panic_handler(const char *fmt, va_list args)
{
    const char *backtrace;

    (void)syslog_handler(LOG_CRIT, fmt, args);
    if (backtrace_get(&backtrace) == 0)
        i_error("Raw backtrace: %s", backtrace);
    abort();
}

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

void i_syslog_error_handler(const char *fmt, va_list args)
{
    if (syslog_handler(LOG_ERR, fmt, args) < 0)
        failure_exit(FATAL_LOGERROR);
}

void i_syslog_warning_handler(const char *fmt, va_list args)
{
    (void)syslog_handler(LOG_WARNING, fmt, args);
}

void i_syslog_info_handler(const char *fmt, va_list args)
{
    (void)syslog_handler(LOG_INFO, fmt, args);
}

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

    i_set_panic_handler(i_syslog_panic_handler);
    i_set_fatal_handler(i_syslog_fatal_handler);
    i_set_error_handler(i_syslog_error_handler);
    i_set_warning_handler(i_syslog_warning_handler);
    i_set_info_handler(i_syslog_info_handler);
}

static void open_log_file(FILE **file, const char *path)
{
    if (*file != NULL && *file != stderr)
        (void)fclose(*file);

    if (path == NULL || strcmp(path, "/dev/stderr") == 0)
        *file = stderr;
    else {
        *file = fopen(path, "a");
        if (*file == NULL) {
            fprintf(stderr, "Can't open log file %s: %s\n",
                path, strerror(errno));
            failure_exit(FATAL_LOGOPEN);
        }
        fd_close_on_exec(fileno(*file), TRUE);
    }
}

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

    if (log_info_fd != NULL && log_info_fd != log_fd &&
        log_info_fd != stderr)
        (void)fclose(log_info_fd);

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

    i_set_panic_handler(NULL);
    i_set_fatal_handler(NULL);
    i_set_error_handler(NULL);
    i_set_warning_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__(1, 0)
i_internal_panic_handler(const char *fmt, va_list args)
{
    const char *backtrace;

    (void)internal_handler('F', fmt, args);
    if (backtrace_get(&backtrace) == 0)
        i_error("Raw backtrace: %s", backtrace);
        abort();
}

static void __attr_noreturn__ __attr_format__(2, 0)
i_internal_fatal_handler(int status, const char *fmt, va_list args)
{
    if (internal_handler('F', fmt, args) < 0 && status == FATAL_DEFAULT)
        status = FATAL_LOGERROR;
    failure_exit(status);
}

static void __attr_format__(1, 0)
i_internal_error_handler(const char *fmt, va_list args)
{
    if (internal_handler('E', fmt, args) < 0)
        failure_exit(FATAL_LOGERROR);
}

static void __attr_format__(1, 0)
i_internal_warning_handler(const char *fmt, va_list args)
{
    (void)internal_handler('W', fmt, args);
}

static void __attr_format__(1, 0)
i_internal_info_handler(const char *fmt, va_list args)
{
    (void)internal_handler('I', fmt, args);
}

void i_set_failure_internal(void)
{
    i_set_panic_handler(i_internal_panic_handler);
    i_set_fatal_handler(i_internal_fatal_handler);
    i_set_error_handler(i_internal_error_handler);
    i_set_warning_handler(i_internal_warning_handler);
    i_set_info_handler(i_internal_info_handler);
}

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

    open_log_file(&log_info_fd, path);
        info_handler = default_info_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 = NULL;

    if (log_fd != NULL && log_fd != stderr) {
        (void)fclose(log_fd);
        log_fd = stderr;
    }

    if (log_info_fd != NULL && log_info_fd != stderr) {
        (void)fclose(log_info_fd);
        log_info_fd = stderr;
    }

    i_free_and_null(log_prefix);
    i_free_and_null(log_stamp_format);
}