Merge pull request #2870 from AnuradhaKaruppiah/bgp-default-del

[mirror_frr.git] / lib / log.c

/*
 * Logging of zebra
 * Copyright (C) 1997, 1998, 1999 Kunihiro Ishiguro
 *
 * This file is part of GNU Zebra.
 *
 * GNU Zebra is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2, or (at your option) any
 * later version.
 *
 * GNU Zebra 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
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; see the file COPYING; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 */

#define FRR_DEFINE_DESC_TABLE

#include <zebra.h>

#include "zclient.h"
#include "log.h"
#include "log_int.h"
#include "memory.h"
#include "command.h"
#include "lib_errors.h"

#ifndef SUNOS_5
#include <sys/un.h>
#endif
/* for printstack on solaris */
#ifdef HAVE_UCONTEXT_H
#include <ucontext.h>
#endif

DEFINE_MTYPE_STATIC(LIB, ZLOG, "Logging")

static int logfile_fd = -1; /* Used in signal handler. */

struct zlog *zlog_default = NULL;
bool zlog_startup_stderr = true;

/* lock protecting zlog_default for mt-safe zlog */
pthread_mutex_t loglock = PTHREAD_MUTEX_INITIALIZER;

const char *zlog_priority[] = {
        "emergencies",   "alerts",      "critical",  "errors", "warnings",
        "notifications", "informational", "debugging", NULL,
};

/*
 * write_wrapper
 *
 * glibc has declared that the return value from write *must* not be
 * ignored.
 * gcc see's this problem and issues a warning for the line.
 *
 * Why is this a big deal you say?  Because both of them are right
 * and if you have -Werror enabled then all calls to write
 * generate a build error and the build stops.
 *
 * clang has helpfully allowed this construct:
 * (void)write(...)
 * to tell the compiler yeah I know it has a return value
 * I don't care about it at this time.
 * gcc doesn't have this ability.
 *
 * This code was written such that it didn't care about the
 * return value from write.  At this time do I want
 * to go through and fix and test this code for correctness.
 * So just wrapper the bad behavior and move on.
 */
static void write_wrapper(int fd, const void *buf, size_t count)
{
        if (write(fd, buf, count) <= 0)
                return;

        return;
}

/**
 * Looks up a message in a message list by key.
 *
 * If the message is not found, returns the provided error message.
 *
 * Terminates when it hits a struct message that's all zeros.
 *
 * @param mz the message list
 * @param kz the message key
 * @param nf the message to return if not found
 * @return the message
 */
const char *lookup_msg(const struct message *mz, int kz, const char *nf)
{
        static struct message nt = {0};
        const char *rz = nf ? nf : "(no message found)";
        const struct message *pnt;
        for (pnt = mz; memcmp(pnt, &nt, sizeof(struct message)); pnt++)
                if (pnt->key == kz) {
                        rz = pnt->str ? pnt->str : rz;
                        break;
                }
        return rz;
}

/* For time string format. */
size_t quagga_timestamp(int timestamp_precision, char *buf, size_t buflen)
{
        static struct {
                time_t last;
                size_t len;
                char buf[28];
        } cache;
        struct timeval clock;

        gettimeofday(&clock, NULL);

        /* first, we update the cache if the time has changed */
        if (cache.last != clock.tv_sec) {
                struct tm *tm;
                cache.last = clock.tv_sec;
                tm = localtime(&cache.last);
                cache.len = strftime(cache.buf, sizeof(cache.buf),
                                     "%Y/%m/%d %H:%M:%S", tm);
        }
        /* note: it's not worth caching the subsecond part, because
           chances are that back-to-back calls are not sufficiently close
           together
           for the clock not to have ticked forward */

        if (buflen > cache.len) {
                memcpy(buf, cache.buf, cache.len);
                if ((timestamp_precision > 0)
                    && (buflen > cache.len + 1 + timestamp_precision)) {
                        /* should we worry about locale issues? */
                        static const int divisor[] = {0,   100000, 10000, 1000,
                                                      100, 10,     1};
                        int prec;
                        char *p = buf + cache.len + 1
                                  + (prec = timestamp_precision);
                        *p-- = '\0';
                        while (prec > 6)
                        /* this is unlikely to happen, but protect anyway */
                        {
                                *p-- = '0';
                                prec--;
                        }
                        clock.tv_usec /= divisor[prec];
                        do {
                                *p-- = '0' + (clock.tv_usec % 10);
                                clock.tv_usec /= 10;
                        } while (--prec > 0);
                        *p = '.';
                        return cache.len + 1 + timestamp_precision;
                }
                buf[cache.len] = '\0';
                return cache.len;
        }
        if (buflen > 0)
                buf[0] = '\0';
        return 0;
}

/* Utility routine for current time printing. */
static void time_print(FILE *fp, struct timestamp_control *ctl)
{
        if (!ctl->already_rendered) {
                ctl->len = quagga_timestamp(ctl->precision, ctl->buf,
                                            sizeof(ctl->buf));
                ctl->already_rendered = 1;
        }
        fprintf(fp, "%s ", ctl->buf);
}


static void vzlog_file(struct zlog *zl, struct timestamp_control *tsctl,
                       const char *proto_str, int record_priority, int priority,
                       FILE *fp, const char *format, va_list args)
{
        va_list ac;

        time_print(fp, tsctl);
        if (record_priority)
                fprintf(fp, "%s: ", zlog_priority[priority]);

        fprintf(fp, "%s", proto_str);
        va_copy(ac, args);
        vfprintf(fp, format, ac);
        va_end(ac);
        fprintf(fp, "\n");
        fflush(fp);
}

/* va_list version of zlog. */
void vzlog(int priority, const char *format, va_list args)
{
        pthread_mutex_lock(&loglock);

        char proto_str[32];
        int original_errno = errno;
        struct timestamp_control tsctl;
        tsctl.already_rendered = 0;
        struct zlog *zl = zlog_default;

        /* When zlog_default is also NULL, use stderr for logging. */
        if (zl == NULL) {
                tsctl.precision = 0;
                time_print(stderr, &tsctl);
                fprintf(stderr, "%s: ", "unknown");
                vfprintf(stderr, format, args);
                fprintf(stderr, "\n");
                fflush(stderr);

                /* In this case we return at here. */
                errno = original_errno;
                pthread_mutex_unlock(&loglock);
                return;
        }
        tsctl.precision = zl->timestamp_precision;

        /* Syslog output */
        if (priority <= zl->maxlvl[ZLOG_DEST_SYSLOG]) {
                va_list ac;
                va_copy(ac, args);
                vsyslog(priority | zlog_default->facility, format, ac);
                va_end(ac);
        }

        if (zl->instance)
                sprintf(proto_str, "%s[%d]: ", zl->protoname, zl->instance);
        else
                sprintf(proto_str, "%s: ", zl->protoname);

        /* File output. */
        if ((priority <= zl->maxlvl[ZLOG_DEST_FILE]) && zl->fp)
                vzlog_file(zl, &tsctl, proto_str, zl->record_priority, priority,
                           zl->fp, format, args);

        /* fixed-config logging to stderr while we're stating up & haven't
         * daemonized / reached mainloop yet
         *
         * note the "else" on stdout output -- we don't want to print the same
         * message to both stderr and stdout. */
        if (zlog_startup_stderr && priority <= LOG_WARNING)
                vzlog_file(zl, &tsctl, proto_str, 1, priority, stderr, format,
                           args);
        else if (priority <= zl->maxlvl[ZLOG_DEST_STDOUT])
                vzlog_file(zl, &tsctl, proto_str, zl->record_priority, priority,
                           stdout, format, args);

        /* Terminal monitor. */
        if (priority <= zl->maxlvl[ZLOG_DEST_MONITOR])
                vty_log((zl->record_priority ? zlog_priority[priority] : NULL),
                        proto_str, format, &tsctl, args);

        errno = original_errno;
        pthread_mutex_unlock(&loglock);
}

int vzlog_test(int priority)
{
        pthread_mutex_lock(&loglock);

        int ret = 0;

        struct zlog *zl = zlog_default;

        /* When zlog_default is also NULL, use stderr for logging. */
        if (zl == NULL)
                ret = 1;
        /* Syslog output */
        else if (priority <= zl->maxlvl[ZLOG_DEST_SYSLOG])
                ret = 1;
        /* File output. */
        else if ((priority <= zl->maxlvl[ZLOG_DEST_FILE]) && zl->fp)
                ret = 1;
        /* stdout output. */
        else if (priority <= zl->maxlvl[ZLOG_DEST_STDOUT])
                ret = 1;
        /* Terminal monitor. */
        else if (priority <= zl->maxlvl[ZLOG_DEST_MONITOR])
                ret = 1;

        pthread_mutex_unlock(&loglock);

        return ret;
}

static char *str_append(char *dst, int len, const char *src)
{
        while ((len-- > 0) && *src)
                *dst++ = *src++;
        return dst;
}

static char *num_append(char *s, int len, unsigned long x)
{
        char buf[30];
        char *t;

        if (!x)
                return str_append(s, len, "0");
        *(t = &buf[sizeof(buf) - 1]) = '\0';
        while (x && (t > buf)) {
                *--t = '0' + (x % 10);
                x /= 10;
        }
        return str_append(s, len, t);
}

#if defined(SA_SIGINFO) || defined(HAVE_STACK_TRACE)
static char *hex_append(char *s, int len, unsigned long x)
{
        char buf[30];
        char *t;

        if (!x)
                return str_append(s, len, "0");
        *(t = &buf[sizeof(buf) - 1]) = '\0';
        while (x && (t > buf)) {
                unsigned int cc = (x % 16);
                *--t = ((cc < 10) ? ('0' + cc) : ('a' + cc - 10));
                x /= 16;
        }
        return str_append(s, len, t);
}
#endif

/* Needs to be enhanced to support Solaris. */
static int syslog_connect(void)
{
#ifdef SUNOS_5
        return -1;
#else
        int fd;
        char *s;
        struct sockaddr_un addr;

        if ((fd = socket(AF_UNIX, SOCK_DGRAM, 0)) < 0)
                return -1;
        addr.sun_family = AF_UNIX;
#ifdef _PATH_LOG
#define SYSLOG_SOCKET_PATH _PATH_LOG
#else
#define SYSLOG_SOCKET_PATH "/dev/log"
#endif
        s = str_append(addr.sun_path, sizeof(addr.sun_path),
                       SYSLOG_SOCKET_PATH);
#undef SYSLOG_SOCKET_PATH
        *s = '\0';
        if (connect(fd, (struct sockaddr *)&addr, sizeof(addr)) < 0) {
                close(fd);
                return -1;
        }
        return fd;
#endif
}

static void syslog_sigsafe(int priority, const char *msg, size_t msglen)
{
        static int syslog_fd = -1;
        char buf[sizeof("<1234567890>ripngd[1234567890]: ") + msglen + 50];
        char *s;

        if ((syslog_fd < 0) && ((syslog_fd = syslog_connect()) < 0))
                return;

#define LOC s,buf+sizeof(buf)-s
        s = buf;
        s = str_append(LOC, "<");
        s = num_append(LOC, priority);
        s = str_append(LOC, ">");
        /* forget about the timestamp, too difficult in a signal handler */
        s = str_append(LOC, zlog_default->ident);
        if (zlog_default->syslog_options & LOG_PID) {
                s = str_append(LOC, "[");
                s = num_append(LOC, getpid());
                s = str_append(LOC, "]");
        }
        s = str_append(LOC, ": ");
        s = str_append(LOC, msg);
        write_wrapper(syslog_fd, buf, s - buf);
#undef LOC
}

static int open_crashlog(void)
{
#define CRASHLOG_PREFIX "/var/tmp/quagga."
#define CRASHLOG_SUFFIX "crashlog"
        if (zlog_default && zlog_default->ident) {
                /* Avoid strlen since it is not async-signal-safe. */
                const char *p;
                size_t ilen;

                for (p = zlog_default->ident, ilen = 0; *p; p++)
                        ilen++;
                {
                        char buf[sizeof(CRASHLOG_PREFIX) + ilen
                                 + sizeof(CRASHLOG_SUFFIX) + 3];
                        char *s = buf;
#define LOC s,buf+sizeof(buf)-s
                        s = str_append(LOC, CRASHLOG_PREFIX);
                        s = str_append(LOC, zlog_default->ident);
                        s = str_append(LOC, ".");
                        s = str_append(LOC, CRASHLOG_SUFFIX);
#undef LOC
                        *s = '\0';
                        return open(buf, O_WRONLY | O_CREAT | O_EXCL,
                                    LOGFILE_MASK);
                }
        }
        return open(CRASHLOG_PREFIX CRASHLOG_SUFFIX,
                    O_WRONLY | O_CREAT | O_EXCL, LOGFILE_MASK);
#undef CRASHLOG_SUFFIX
#undef CRASHLOG_PREFIX
}

/* Note: the goal here is to use only async-signal-safe functions. */
void zlog_signal(int signo, const char *action
#ifdef SA_SIGINFO
                 ,
                 siginfo_t *siginfo, void *program_counter
#endif
                 )
{
        time_t now;
        char buf[sizeof("DEFAULT: Received signal S at T (si_addr 0xP, PC 0xP); aborting...")
                 + 100];
        char *s = buf;
        char *msgstart = buf;
#define LOC s,buf+sizeof(buf)-s

        time(&now);
        if (zlog_default) {
                s = str_append(LOC, zlog_default->protoname);
                *s++ = ':';
                *s++ = ' ';
                msgstart = s;
        }
        s = str_append(LOC, "Received signal ");
        s = num_append(LOC, signo);
        s = str_append(LOC, " at ");
        s = num_append(LOC, now);
#ifdef SA_SIGINFO
        s = str_append(LOC, " (si_addr 0x");
        s = hex_append(LOC, (unsigned long)(siginfo->si_addr));
        if (program_counter) {
                s = str_append(LOC, ", PC 0x");
                s = hex_append(LOC, (unsigned long)program_counter);
        }
        s = str_append(LOC, "); ");
#else  /* SA_SIGINFO */
        s = str_append(LOC, "; ");
#endif /* SA_SIGINFO */
        s = str_append(LOC, action);
        if (s < buf + sizeof(buf))
                *s++ = '\n';

/* N.B. implicit priority is most severe */
#define PRI LOG_CRIT

#define DUMP(FD) write_wrapper(FD, buf, s-buf);
        /* If no file logging configured, try to write to fallback log file. */
        if ((logfile_fd >= 0) || ((logfile_fd = open_crashlog()) >= 0))
                DUMP(logfile_fd)
        if (!zlog_default)
                DUMP(STDERR_FILENO)
        else {
                if (PRI <= zlog_default->maxlvl[ZLOG_DEST_STDOUT])
                        DUMP(STDOUT_FILENO)
                /* Remove trailing '\n' for monitor and syslog */
                *--s = '\0';
                if (PRI <= zlog_default->maxlvl[ZLOG_DEST_MONITOR])
                        vty_log_fixed(buf, s - buf);
                if (PRI <= zlog_default->maxlvl[ZLOG_DEST_SYSLOG])
                        syslog_sigsafe(PRI | zlog_default->facility, msgstart,
                                       s - msgstart);
        }
#undef DUMP

        zlog_backtrace_sigsafe(PRI,
#ifdef SA_SIGINFO
                               program_counter
#else
                               NULL
#endif
                               );

        s = buf;
        struct thread *tc;
        tc = pthread_getspecific(thread_current);
        if (!tc)
                s = str_append(LOC, "no thread information available\n");
        else {
                s = str_append(LOC, "in thread ");
                s = str_append(LOC, tc->funcname);
                s = str_append(LOC, " scheduled from ");
                s = str_append(LOC, tc->schedfrom);
                s = str_append(LOC, ":");
                s = num_append(LOC, tc->schedfrom_line);
                s = str_append(LOC, "\n");
        }

#define DUMP(FD) write_wrapper(FD, buf, s-buf);
        /* If no file logging configured, try to write to fallback log file. */
        if (logfile_fd >= 0)
                DUMP(logfile_fd)
        if (!zlog_default)
                DUMP(STDERR_FILENO)
        else {
                if (PRI <= zlog_default->maxlvl[ZLOG_DEST_STDOUT])
                        DUMP(STDOUT_FILENO)
                /* Remove trailing '\n' for monitor and syslog */
                *--s = '\0';
                if (PRI <= zlog_default->maxlvl[ZLOG_DEST_MONITOR])
                        vty_log_fixed(buf, s - buf);
                if (PRI <= zlog_default->maxlvl[ZLOG_DEST_SYSLOG])
                        syslog_sigsafe(PRI | zlog_default->facility, msgstart,
                                       s - msgstart);
        }
#undef DUMP

#undef PRI
#undef LOC
}

/* Log a backtrace using only async-signal-safe functions.
   Needs to be enhanced to support syslog logging. */
void zlog_backtrace_sigsafe(int priority, void *program_counter)
{
#ifdef HAVE_STACK_TRACE
        static const char pclabel[] = "Program counter: ";
        void *array[64];
        int size;
        char buf[100];
        char *s, **bt = NULL;
#define LOC s,buf+sizeof(buf)-s

#ifdef HAVE_GLIBC_BACKTRACE
        size = backtrace(array, array_size(array));
        if (size <= 0 || (size_t)size > array_size(array))
                return;

#define DUMP(FD)                                                               \
        {                                                                      \
                if (program_counter) {                                         \
                        write_wrapper(FD, pclabel, sizeof(pclabel) - 1);       \
                        backtrace_symbols_fd(&program_counter, 1, FD);         \
                }                                                              \
                write_wrapper(FD, buf, s - buf);                               \
                backtrace_symbols_fd(array, size, FD);                         \
        }
#elif defined(HAVE_PRINTSTACK)
#define DUMP(FD)                                                               \
        {                                                                      \
                if (program_counter)                                           \
                        write_wrapper((FD), pclabel, sizeof(pclabel) - 1);     \
                write_wrapper((FD), buf, s - buf);                             \
                printstack((FD));                                              \
        }
#endif /* HAVE_GLIBC_BACKTRACE, HAVE_PRINTSTACK */

        s = buf;
        s = str_append(LOC, "Backtrace for ");
        s = num_append(LOC, size);
        s = str_append(LOC, " stack frames:\n");

        if ((logfile_fd >= 0) || ((logfile_fd = open_crashlog()) >= 0))
                DUMP(logfile_fd)
        if (!zlog_default)
                DUMP(STDERR_FILENO)
        else {
                if (priority <= zlog_default->maxlvl[ZLOG_DEST_STDOUT])
                        DUMP(STDOUT_FILENO)
                /* Remove trailing '\n' for monitor and syslog */
                *--s = '\0';
                if (priority <= zlog_default->maxlvl[ZLOG_DEST_MONITOR])
                        vty_log_fixed(buf, s - buf);
                if (priority <= zlog_default->maxlvl[ZLOG_DEST_SYSLOG])
                        syslog_sigsafe(priority | zlog_default->facility, buf,
                                       s - buf);
                {
                        int i;
#ifdef HAVE_GLIBC_BACKTRACE
                        bt = backtrace_symbols(array, size);
#endif
                        /* Just print the function addresses. */
                        for (i = 0; i < size; i++) {
                                s = buf;
                                if (bt)
                                        s = str_append(LOC, bt[i]);
                                else {
                                        s = str_append(LOC, "[bt ");
                                        s = num_append(LOC, i);
                                        s = str_append(LOC, "] 0x");
                                        s = hex_append(
                                                LOC, (unsigned long)(array[i]));
                                }
                                *s = '\0';
                                if (priority
                                    <= zlog_default->maxlvl[ZLOG_DEST_MONITOR])
                                        vty_log_fixed(buf, s - buf);
                                if (priority
                                    <= zlog_default->maxlvl[ZLOG_DEST_SYSLOG])
                                        syslog_sigsafe(
                                                priority
                                                        | zlog_default
                                                                  ->facility,
                                                buf, s - buf);
                        }
                        if (bt)
                                free(bt);
                }
        }
#undef DUMP
#undef LOC
#endif /* HAVE_STRACK_TRACE */
}

void zlog_backtrace(int priority)
{
#ifndef HAVE_GLIBC_BACKTRACE
        zlog(priority, "No backtrace available on this platform.");
#else
        void *array[20];
        int size, i;
        char **strings;

        size = backtrace(array, array_size(array));
        if (size <= 0 || (size_t)size > array_size(array)) {
                flog_err_sys(
                        LIB_ERR_SYSTEM_CALL,
                        "Cannot get backtrace, returned invalid # of frames %d "
                        "(valid range is between 1 and %lu)",
                        size, (unsigned long)(array_size(array)));
                return;
        }
        zlog(priority, "Backtrace for %d stack frames:", size);
        if (!(strings = backtrace_symbols(array, size))) {
                flog_err_sys(LIB_ERR_SYSTEM_CALL,
                             "Cannot get backtrace symbols (out of memory?)");
                for (i = 0; i < size; i++)
                        zlog(priority, "[bt %d] %p", i, array[i]);
        } else {
                for (i = 0; i < size; i++)
                        zlog(priority, "[bt %d] %s", i, strings[i]);
                free(strings);
        }
#endif /* HAVE_GLIBC_BACKTRACE */
}

void zlog(int priority, const char *format, ...)
{
        va_list args;

        va_start(args, format);
        vzlog(priority, format, args);
        va_end(args);
}

#define ZLOG_FUNC(FUNCNAME, PRIORITY)                                          \
        void FUNCNAME(const char *format, ...)                                 \
        {                                                                      \
                va_list args;                                                  \
                va_start(args, format);                                        \
                vzlog(PRIORITY, format, args);                                 \
                va_end(args);                                                  \
        }

ZLOG_FUNC(zlog_err, LOG_ERR)

ZLOG_FUNC(zlog_warn, LOG_WARNING)

ZLOG_FUNC(zlog_info, LOG_INFO)

ZLOG_FUNC(zlog_notice, LOG_NOTICE)

ZLOG_FUNC(zlog_debug, LOG_DEBUG)

#undef ZLOG_FUNC

void zlog_thread_info(int log_level)
{
        struct thread *tc;
        tc = pthread_getspecific(thread_current);

        if (tc)
                zlog(log_level,
                     "Current thread function %s, scheduled from "
                     "file %s, line %u",
                     tc->funcname, tc->schedfrom, tc->schedfrom_line);
        else
                zlog(log_level, "Current thread not known/applicable");
}

void _zlog_assert_failed(const char *assertion, const char *file,
                         unsigned int line, const char *function)
{
        /* Force fallback file logging? */
        if (zlog_default && !zlog_default->fp
            && ((logfile_fd = open_crashlog()) >= 0)
            && ((zlog_default->fp = fdopen(logfile_fd, "w")) != NULL))
                zlog_default->maxlvl[ZLOG_DEST_FILE] = LOG_ERR;
        zlog(LOG_CRIT, "Assertion `%s' failed in file %s, line %u, function %s",
             assertion, file, line, (function ? function : "?"));
        zlog_backtrace(LOG_CRIT);
        zlog_thread_info(LOG_CRIT);
        log_memstats(stderr, "log");
        abort();
}

void memory_oom(size_t size, const char *name)
{
        flog_err_sys(LIB_ERR_SYSTEM_CALL,
                     "out of memory: failed to allocate %zu bytes for %s"
                     "object",
                     size, name);
        zlog_backtrace(LOG_ERR);
        abort();
}

/* Open log stream */
void openzlog(const char *progname, const char *protoname,
              unsigned short instance, int syslog_flags, int syslog_facility)
{
        struct zlog *zl;
        unsigned int i;

        zl = XCALLOC(MTYPE_ZLOG, sizeof(struct zlog));

        zl->ident = progname;
        zl->protoname = protoname;
        zl->instance = instance;
        zl->facility = syslog_facility;
        zl->syslog_options = syslog_flags;

        /* Set default logging levels. */
        for (i = 0; i < array_size(zl->maxlvl); i++)
                zl->maxlvl[i] = ZLOG_DISABLED;
        zl->maxlvl[ZLOG_DEST_MONITOR] = LOG_DEBUG;
        zl->default_lvl = LOG_DEBUG;

        openlog(progname, syslog_flags, zl->facility);

        pthread_mutex_lock(&loglock);
        zlog_default = zl;
        pthread_mutex_unlock(&loglock);

#ifdef HAVE_GLIBC_BACKTRACE
        /* work around backtrace() using lazily resolved dynamically linked
         * symbols, which will otherwise cause funny breakage in the SEGV
         * handler.
         * (particularly, the dynamic linker can call malloc(), which uses locks
         * in programs linked with -pthread, thus can deadlock.) */
        void *bt[4];
        backtrace(bt, array_size(bt));
        free(backtrace_symbols(bt, 0));
        backtrace_symbols_fd(bt, 0, 0);
#endif
}

void closezlog(void)
{
        pthread_mutex_lock(&loglock);
        struct zlog *zl = zlog_default;

        closelog();

        if (zl->fp != NULL)
                fclose(zl->fp);

        if (zl->filename != NULL)
                XFREE(MTYPE_ZLOG, zl->filename);

        XFREE(MTYPE_ZLOG, zl);
        zlog_default = NULL;
        pthread_mutex_unlock(&loglock);
}

/* Called from command.c. */
void zlog_set_level(zlog_dest_t dest, int log_level)
{
        pthread_mutex_lock(&loglock);
        zlog_default->maxlvl[dest] = log_level;
        pthread_mutex_unlock(&loglock);
}

int zlog_set_file(const char *filename, int log_level)
{
        struct zlog *zl;
        FILE *fp;
        mode_t oldumask;
        int ret = 1;

        /* There is opend file.  */
        zlog_reset_file();

        /* Open file. */
        oldumask = umask(0777 & ~LOGFILE_MASK);
        fp = fopen(filename, "a");
        umask(oldumask);
        if (fp == NULL) {
                ret = 0;
        } else {
                pthread_mutex_lock(&loglock);
                zl = zlog_default;

                /* Set flags. */
                zl->filename = XSTRDUP(MTYPE_ZLOG, filename);
                zl->maxlvl[ZLOG_DEST_FILE] = log_level;
                zl->fp = fp;
                logfile_fd = fileno(fp);
                pthread_mutex_unlock(&loglock);
        }

        return ret;
}

/* Reset opend file. */
int zlog_reset_file(void)
{
        pthread_mutex_lock(&loglock);

        struct zlog *zl = zlog_default;

        if (zl->fp)
                fclose(zl->fp);
        zl->fp = NULL;
        logfile_fd = -1;
        zl->maxlvl[ZLOG_DEST_FILE] = ZLOG_DISABLED;

        if (zl->filename)
                XFREE(MTYPE_ZLOG, zl->filename);
        zl->filename = NULL;

        pthread_mutex_unlock(&loglock);

        return 1;
}

/* Reopen log file. */
int zlog_rotate(void)
{
        pthread_mutex_lock(&loglock);

        struct zlog *zl = zlog_default;
        int level;
        int ret = 1;

        if (zl->fp)
                fclose(zl->fp);
        zl->fp = NULL;
        logfile_fd = -1;
        level = zl->maxlvl[ZLOG_DEST_FILE];
        zl->maxlvl[ZLOG_DEST_FILE] = ZLOG_DISABLED;

        if (zl->filename) {
                mode_t oldumask;
                int save_errno;

                oldumask = umask(0777 & ~LOGFILE_MASK);
                zl->fp = fopen(zl->filename, "a");
                save_errno = errno;
                umask(oldumask);
                if (zl->fp == NULL) {

                        pthread_mutex_unlock(&loglock);

                        flog_err_sys(
                                LIB_ERR_SYSTEM_CALL,
                                "Log rotate failed: cannot open file %s for append: %s",
                                zl->filename, safe_strerror(save_errno));
                        ret = -1;

                        pthread_mutex_lock(&loglock);
                } else {
                        logfile_fd = fileno(zl->fp);
                        zl->maxlvl[ZLOG_DEST_FILE] = level;
                }
        }

        pthread_mutex_unlock(&loglock);

        return ret;
}

/* Wrapper around strerror to handle case where it returns NULL. */
const char *safe_strerror(int errnum)
{
        const char *s = strerror(errnum);
        return (s != NULL) ? s : "Unknown error";
}

#define DESC_ENTRY(T) [(T)] = { (T), (#T), '\0' }
static const struct zebra_desc_table command_types[] = {
        DESC_ENTRY(ZEBRA_INTERFACE_ADD),
        DESC_ENTRY(ZEBRA_INTERFACE_DELETE),
        DESC_ENTRY(ZEBRA_INTERFACE_ADDRESS_ADD),
        DESC_ENTRY(ZEBRA_INTERFACE_ADDRESS_DELETE),
        DESC_ENTRY(ZEBRA_INTERFACE_UP),
        DESC_ENTRY(ZEBRA_INTERFACE_DOWN),
        DESC_ENTRY(ZEBRA_INTERFACE_SET_MASTER),
        DESC_ENTRY(ZEBRA_ROUTE_ADD),
        DESC_ENTRY(ZEBRA_ROUTE_DELETE),
        DESC_ENTRY(ZEBRA_ROUTE_NOTIFY_OWNER),
        DESC_ENTRY(ZEBRA_REDISTRIBUTE_ADD),
        DESC_ENTRY(ZEBRA_REDISTRIBUTE_DELETE),
        DESC_ENTRY(ZEBRA_REDISTRIBUTE_DEFAULT_ADD),
        DESC_ENTRY(ZEBRA_REDISTRIBUTE_DEFAULT_DELETE),
        DESC_ENTRY(ZEBRA_ROUTER_ID_ADD),
        DESC_ENTRY(ZEBRA_ROUTER_ID_DELETE),
        DESC_ENTRY(ZEBRA_ROUTER_ID_UPDATE),
        DESC_ENTRY(ZEBRA_HELLO),
        DESC_ENTRY(ZEBRA_NEXTHOP_REGISTER),
        DESC_ENTRY(ZEBRA_NEXTHOP_UNREGISTER),
        DESC_ENTRY(ZEBRA_NEXTHOP_UPDATE),
        DESC_ENTRY(ZEBRA_INTERFACE_NBR_ADDRESS_ADD),
        DESC_ENTRY(ZEBRA_INTERFACE_NBR_ADDRESS_DELETE),
        DESC_ENTRY(ZEBRA_INTERFACE_BFD_DEST_UPDATE),
        DESC_ENTRY(ZEBRA_IMPORT_ROUTE_REGISTER),
        DESC_ENTRY(ZEBRA_IMPORT_ROUTE_UNREGISTER),
        DESC_ENTRY(ZEBRA_IMPORT_CHECK_UPDATE),
        DESC_ENTRY(ZEBRA_IPV4_ROUTE_IPV6_NEXTHOP_ADD),
        DESC_ENTRY(ZEBRA_BFD_DEST_REGISTER),
        DESC_ENTRY(ZEBRA_BFD_DEST_DEREGISTER),
        DESC_ENTRY(ZEBRA_BFD_DEST_UPDATE),
        DESC_ENTRY(ZEBRA_BFD_DEST_REPLAY),
        DESC_ENTRY(ZEBRA_REDISTRIBUTE_ROUTE_ADD),
        DESC_ENTRY(ZEBRA_REDISTRIBUTE_ROUTE_DEL),
        DESC_ENTRY(ZEBRA_VRF_UNREGISTER),
        DESC_ENTRY(ZEBRA_VRF_ADD),
        DESC_ENTRY(ZEBRA_VRF_DELETE),
        DESC_ENTRY(ZEBRA_VRF_LABEL),
        DESC_ENTRY(ZEBRA_INTERFACE_VRF_UPDATE),
        DESC_ENTRY(ZEBRA_BFD_CLIENT_REGISTER),
        DESC_ENTRY(ZEBRA_INTERFACE_ENABLE_RADV),
        DESC_ENTRY(ZEBRA_INTERFACE_DISABLE_RADV),
        DESC_ENTRY(ZEBRA_IPV4_NEXTHOP_LOOKUP_MRIB),
        DESC_ENTRY(ZEBRA_INTERFACE_LINK_PARAMS),
        DESC_ENTRY(ZEBRA_MPLS_LABELS_ADD),
        DESC_ENTRY(ZEBRA_MPLS_LABELS_DELETE),
        DESC_ENTRY(ZEBRA_IPMR_ROUTE_STATS),
        DESC_ENTRY(ZEBRA_LABEL_MANAGER_CONNECT),
        DESC_ENTRY(ZEBRA_GET_LABEL_CHUNK),
        DESC_ENTRY(ZEBRA_RELEASE_LABEL_CHUNK),
        DESC_ENTRY(ZEBRA_ADVERTISE_ALL_VNI),
        DESC_ENTRY(ZEBRA_ADVERTISE_DEFAULT_GW),
        DESC_ENTRY(ZEBRA_ADVERTISE_SUBNET),
        DESC_ENTRY(ZEBRA_LOCAL_ES_ADD),
        DESC_ENTRY(ZEBRA_LOCAL_ES_DEL),
        DESC_ENTRY(ZEBRA_VNI_ADD),
        DESC_ENTRY(ZEBRA_VNI_DEL),
        DESC_ENTRY(ZEBRA_L3VNI_ADD),
        DESC_ENTRY(ZEBRA_L3VNI_DEL),
        DESC_ENTRY(ZEBRA_REMOTE_VTEP_ADD),
        DESC_ENTRY(ZEBRA_REMOTE_VTEP_DEL),
        DESC_ENTRY(ZEBRA_MACIP_ADD),
        DESC_ENTRY(ZEBRA_MACIP_DEL),
        DESC_ENTRY(ZEBRA_IP_PREFIX_ROUTE_ADD),
        DESC_ENTRY(ZEBRA_IP_PREFIX_ROUTE_DEL),
        DESC_ENTRY(ZEBRA_REMOTE_MACIP_ADD),
        DESC_ENTRY(ZEBRA_REMOTE_MACIP_DEL),
        DESC_ENTRY(ZEBRA_PW_ADD),
        DESC_ENTRY(ZEBRA_PW_DELETE),
        DESC_ENTRY(ZEBRA_PW_SET),
        DESC_ENTRY(ZEBRA_PW_UNSET),
        DESC_ENTRY(ZEBRA_PW_STATUS_UPDATE),
        DESC_ENTRY(ZEBRA_RULE_ADD),
        DESC_ENTRY(ZEBRA_RULE_DELETE),
        DESC_ENTRY(ZEBRA_RULE_NOTIFY_OWNER),
        DESC_ENTRY(ZEBRA_TABLE_MANAGER_CONNECT),
        DESC_ENTRY(ZEBRA_GET_TABLE_CHUNK),
        DESC_ENTRY(ZEBRA_RELEASE_TABLE_CHUNK),
        DESC_ENTRY(ZEBRA_IPSET_CREATE),
        DESC_ENTRY(ZEBRA_IPSET_DESTROY),
        DESC_ENTRY(ZEBRA_IPSET_ENTRY_ADD),
        DESC_ENTRY(ZEBRA_IPSET_ENTRY_DELETE),
};
#undef DESC_ENTRY

static const struct zebra_desc_table unknown = {0, "unknown", '?'};

static const struct zebra_desc_table *zroute_lookup(unsigned int zroute)
{
        unsigned int i;

        if (zroute >= array_size(route_types)) {
                flog_err(LIB_ERR_DEVELOPMENT, "unknown zebra route type: %u",
                          zroute);
                return &unknown;
        }
        if (zroute == route_types[zroute].type)
                return &route_types[zroute];
        for (i = 0; i < array_size(route_types); i++) {
                if (zroute == route_types[i].type) {
                        zlog_warn(
                                "internal error: route type table out of order "
                                "while searching for %u, please notify developers",
                                zroute);
                        return &route_types[i];
                }
        }
        flog_err(LIB_ERR_DEVELOPMENT,
                  "internal error: cannot find route type %u in table!",
                  zroute);
        return &unknown;
}

const char *zebra_route_string(unsigned int zroute)
{
        return zroute_lookup(zroute)->string;
}

char zebra_route_char(unsigned int zroute)
{
        return zroute_lookup(zroute)->chr;
}

const char *zserv_command_string(unsigned int command)
{
        if (command >= array_size(command_types)) {
                flog_err(LIB_ERR_DEVELOPMENT, "unknown zserv command type: %u",
                          command);
                return unknown.string;
        }
        return command_types[command].string;
}

int proto_name2num(const char *s)
{
        unsigned i;

        for (i = 0; i < array_size(route_types); ++i)
                if (strcasecmp(s, route_types[i].string) == 0)
                        return route_types[i].type;
        return -1;
}

int proto_redistnum(int afi, const char *s)
{
        if (!s)
                return -1;

        if (afi == AFI_IP) {
                if (strmatch(s, "kernel"))
                        return ZEBRA_ROUTE_KERNEL;
                else if (strmatch(s, "connected"))
                        return ZEBRA_ROUTE_CONNECT;
                else if (strmatch(s, "static"))
                        return ZEBRA_ROUTE_STATIC;
                else if (strmatch(s, "rip"))
                        return ZEBRA_ROUTE_RIP;
                else if (strmatch(s, "eigrp"))
                        return ZEBRA_ROUTE_EIGRP;
                else if (strmatch(s, "ospf"))
                        return ZEBRA_ROUTE_OSPF;
                else if (strmatch(s, "isis"))
                        return ZEBRA_ROUTE_ISIS;
                else if (strmatch(s, "bgp"))
                        return ZEBRA_ROUTE_BGP;
                else if (strmatch(s, "table"))
                        return ZEBRA_ROUTE_TABLE;
                else if (strmatch(s, "vnc"))
                        return ZEBRA_ROUTE_VNC;
                else if (strmatch(s, "vnc-direct"))
                        return ZEBRA_ROUTE_VNC_DIRECT;
                else if (strmatch(s, "nhrp"))
                        return ZEBRA_ROUTE_NHRP;
                else if (strmatch(s, "babel"))
                        return ZEBRA_ROUTE_BABEL;
                else if (strmatch(s, "sharp"))
                        return ZEBRA_ROUTE_SHARP;
        }
        if (afi == AFI_IP6) {
                if (strmatch(s, "kernel"))
                        return ZEBRA_ROUTE_KERNEL;
                else if (strmatch(s, "connected"))
                        return ZEBRA_ROUTE_CONNECT;
                else if (strmatch(s, "static"))
                        return ZEBRA_ROUTE_STATIC;
                else if (strmatch(s, "ripng"))
                        return ZEBRA_ROUTE_RIPNG;
                else if (strmatch(s, "ospf6"))
                        return ZEBRA_ROUTE_OSPF6;
                else if (strmatch(s, "isis"))
                        return ZEBRA_ROUTE_ISIS;
                else if (strmatch(s, "bgp"))
                        return ZEBRA_ROUTE_BGP;
                else if (strmatch(s, "table"))
                        return ZEBRA_ROUTE_TABLE;
                else if (strmatch(s, "vnc"))
                        return ZEBRA_ROUTE_VNC;
                else if (strmatch(s, "vnc-direct"))
                        return ZEBRA_ROUTE_VNC_DIRECT;
                else if (strmatch(s, "nhrp"))
                        return ZEBRA_ROUTE_NHRP;
                else if (strmatch(s, "babel"))
                        return ZEBRA_ROUTE_BABEL;
                else if (strmatch(s, "sharp"))
                        return ZEBRA_ROUTE_SHARP;
        }
        return -1;
}

void zlog_hexdump(const void *mem, unsigned int len)
{
        unsigned long i = 0;
        unsigned int j = 0;
        unsigned int columns = 8;
        /*
         * 19 bytes for 0xADDRESS:
         * 24 bytes for data; 2 chars plus a space per data byte
         *  1 byte for space
         *  8 bytes for ASCII representation
         *  1 byte for a newline
         * =====================
         * 53 bytes per 8 bytes of data
         *  1 byte for null term
         */
        size_t bs = ((len / 8) + 1) * 53 + 1;
        char buf[bs];
        char *s = buf;

        memset(buf, 0, sizeof(buf));

        for (i = 0; i < len + ((len % columns) ? (columns - len % columns) : 0);
             i++) {
                /* print offset */
                if (i % columns == 0)
                        s += snprintf(s, bs - (s - buf),
                                      "0x%016lx: ", (unsigned long)mem + i);

                /* print hex data */
                if (i < len)
                        s += snprintf(s, bs - (s - buf), "%02x ",
                                      0xFF & ((const char *)mem)[i]);

                /* end of block, just aligning for ASCII dump */
                else
                        s += snprintf(s, bs - (s - buf), "   ");

                /* print ASCII dump */
                if (i % columns == (columns - 1)) {
                        for (j = i - (columns - 1); j <= i; j++) {
                                /* end of block not really printing */
                                if (j >= len)
                                        s += snprintf(s, bs - (s - buf), " ");
                                else if (isprint((int)((const char *)mem)[j]))
                                        s += snprintf(
                                                s, bs - (s - buf), "%c",
                                                0xFF & ((const char *)mem)[j]);
                                else /* other char */
                                        s += snprintf(s, bs - (s - buf), ".");
                        }
                        s += snprintf(s, bs - (s - buf), "\n");
                }
        }
        zlog_debug("\n%s", buf);
}

const char *zlog_sanitize(char *buf, size_t bufsz, const void *in, size_t inlen)
{
        const char *inbuf = in;
        char *pos = buf, *end = buf + bufsz;
        const char *iend = inbuf + inlen;

        memset(buf, 0, bufsz);
        for (; inbuf < iend; inbuf++) {
                /* don't write partial escape sequence */
                if (end - pos < 5)
                        break;

                if (*inbuf == '\n')
                        snprintf(pos, end - pos, "\\n");
                else if (*inbuf == '\r')
                        snprintf(pos, end - pos, "\\r");
                else if (*inbuf == '\t')
                        snprintf(pos, end - pos, "\\t");
                else if (*inbuf < ' ' || *inbuf == '"' || *inbuf >= 127)
                        snprintf(pos, end - pos, "\\x%02hhx", *inbuf);
                else
                        *pos = *inbuf;

                pos += strlen(pos);
        }
        return buf;
}