/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright 2010 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#include <atomic.h>
#include <alloca.h>
#include <syslog.h>
#include <strings.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdarg.h>
#include <stdio.h>
#include <exacct.h>

#include <fmd_subr.h>
#include <fmd_conf.h>
#include <fmd_error.h>
#include <fmd_thread.h>
#include <fmd_protocol.h>
#include <fmd_event.h>
#include <fmd_dispq.h>
#include <fmd_log.h>

#include <fmd.h>

int
fmd_assert(const char *expr, const char *file, int line)
{
        fmd_panic("\"%s\", line %d: assertion failed: %s\n", file, line, expr);
        /*NOTREACHED*/
        return (0);
}

/*
 * To implement a reasonable panic() equivalent for fmd, we atomically bump a
 * global counter of calls to fmd_vpanic() and attempt to print a panic message
 * to stderr and dump core as a result of raising SIGABRT.  This function must
 * not attempt to grab any locks so that it can be called from any fmd code.
 */
void
fmd_vpanic(const char *format, va_list ap)
{
        int oserr = errno;
        pthread_t tid = pthread_self();

        fmd_thread_t *tp;
        char msg[BUFSIZ];
        size_t len;

        /*
         * If this is not the first call to fmd_vpanic(), then check d_panictid
         * to see if we are the panic thread.  If so, then proceed directly to
         * abort() because we have recursively panicked.  If not, then pause()
         * indefinitely waiting for the panic thread to terminate the daemon.
         */
        if (atomic_add_32_nv(&fmd.d_panicrefs, 1) != 1) {
                while (fmd.d_panictid != tid)
                        (void) pause();
                goto abort;
        }

        /*
         * Use fmd.d_pid != 0 as a cheap test to see if fmd.d_key is valid
         * (i.e. we're after fmd_create() and before fmd_destroy()).
         */
        if (fmd.d_pid != 0 && (tp = pthread_getspecific(fmd.d_key)) != NULL)
                (void) tp->thr_trfunc(tp->thr_trdata, FMD_DBG_ERR, format, ap);

        fmd.d_panicstr = msg;
        fmd.d_panictid = tid;

        (void) snprintf(msg, sizeof (msg), "%s: ABORT: ",
            fmd.d_pname ? fmd.d_pname : "fmd");

        len = strlen(msg);
        (void) vsnprintf(msg + len, sizeof (msg) - len, format, ap);

        if (strchr(format, '\n') == NULL) {
                len = strlen(msg);
                (void) snprintf(msg + len, sizeof (msg) - len, ": %s\n",
                    fmd_strerror(oserr));
        }

        (void) write(STDERR_FILENO, msg, strlen(msg));

abort:
        abort();
        _exit(FMD_EXIT_ERROR);
}

/*PRINTFLIKE1*/
void
fmd_panic(const char *format, ...)
{
        va_list ap;

        va_start(ap, format);
        fmd_vpanic(format, ap);
        va_end(ap);
}

void
fmd_verror(int err, const char *format, va_list ap)
{
        int oserr = errno;
        fmd_thread_t *tp;
        nvlist_t *nvl;
        fmd_event_t *e;
        char *class;

        if ((tp = pthread_getspecific(fmd.d_key)) != NULL) {
                (void) tp->thr_trfunc(tp->thr_trdata, FMD_DBG_ERR, format, ap);
                tp->thr_errdepth++;
        }

        (void) pthread_mutex_lock(&fmd.d_err_lock);

        if (fmd.d_errstats != NULL && err >= EFMD_UNKNOWN && err < EFMD_END)
                fmd.d_errstats[err - EFMD_UNKNOWN].fmds_value.ui64++;

        if (fmd.d_fg || !fmd.d_running) {
                (void) fprintf(stderr, "%s: ", fmd.d_pname);
                (void) vfprintf(stderr, format, ap);

                if (strchr(format, '\n') == NULL)
                        (void) fprintf(stderr, ": %s\n", fmd_strerror(oserr));
        }

        (void) pthread_mutex_unlock(&fmd.d_err_lock);

        /*
         * If we are at error nesting level one and running in the background,
         * log the error as an ereport to our own log and dispatch it.  If the
         * FMD_LF_BUSY flag is set, we can't attempt to log the event because
         * a replay is running and we will deadlock on ourself in log_append.
         */
        if (!fmd.d_fg && fmd.d_running &&
            tp != NULL && tp->thr_errdepth == 1 &&
            (nvl = fmd_protocol_fmderror(err, format, ap)) != NULL) {

                (void) nvlist_lookup_string(nvl, FM_CLASS, &class);
                e = fmd_event_create(FMD_EVT_PROTOCOL, FMD_HRT_NOW, nvl, class);

                (void) pthread_rwlock_rdlock(&fmd.d_log_lock);
                if (!(fmd.d_errlog->log_flags & FMD_LF_BUSY))
                        fmd_log_append(fmd.d_errlog, e, NULL);
                (void) pthread_rwlock_unlock(&fmd.d_log_lock);

                fmd_dispq_dispatch(fmd.d_disp, e, class);
        }

        if (tp != NULL)
                tp->thr_errdepth--;

        if (err == EFMD_EXIT) {
                int core = 0;

                (void) fmd_conf_getprop(fmd.d_conf, "core", &core);
                if (core)
                        fmd_panic("forcing core dump at user request\n");

                exit(FMD_EXIT_ERROR);
        }
}

/*PRINTFLIKE2*/
void
fmd_error(int err, const char *format, ...)
{
        va_list ap;

        va_start(ap, format);
        fmd_verror(err, format, ap);
        va_end(ap);
}

void
fmd_vdprintf(int mask, const char *format, va_list ap)
{
        fmd_thread_t *tp;
        char *msg;
        size_t len;
        char c;

        if (!(fmd.d_fmd_debug & mask))
                return; /* none of the specified modes are enabled */

        if ((tp = pthread_getspecific(fmd.d_key)) != NULL)
                (void) tp->thr_trfunc(tp->thr_trdata, mask, format, ap);

        if (fmd.d_fmd_dbout == 0)
                return; /* no debugging output sinks are enabled */

        len = vsnprintf(&c, 1, format, ap);
        msg = alloca(len + 2);
        (void) vsnprintf(msg, len + 1, format, ap);

        if (msg[len - 1] != '\n')
                (void) strcpy(&msg[len], "\n");

        if (fmd.d_fmd_dbout & FMD_DBOUT_STDERR) {
                (void) pthread_mutex_lock(&fmd.d_err_lock);
                (void) fprintf(stderr, "%s DEBUG: %s", fmd.d_pname, msg);
                (void) pthread_mutex_unlock(&fmd.d_err_lock);
        }

        if (fmd.d_fmd_dbout & FMD_DBOUT_SYSLOG) {
                syslog(LOG_DEBUG | LOG_DAEMON,
                    "%s DEBUG: %s", fmd.d_pname, msg);
        }
}

/*PRINTFLIKE2*/
void
fmd_dprintf(int mask, const char *format, ...)
{
        va_list ap;

        va_start(ap, format);
        fmd_vdprintf(mask, format, ap);
        va_end(ap);
}

/*
 * The fmd_trace.c routines set tr_file and tr_line to NULL and 0 respectively.
 * If they are invoked from a macro (see <fmd_subr.h>) this tail function is
 * called as part of the TRACE() macro to fill in these fields from the cpp
 * macro values for __FILE__ and __LINE__.  No locking is needed because all
 * trace buffers are allocated separately for each fmd thread.
 */
void
fmd_trace_cpp(void *ptr, const char *file, int line)
{
        fmd_tracerec_t *trp = ptr;

        if (trp != NULL) {
                trp->tr_file = file;
                trp->tr_line = line;
        }
}

/*
 * The fmd_trace() function is the wrapper for the tracing routines provided in
 * fmd_trace.c.  It is invoked by the TRACE() macro in <fmd_subr.h>, and uses
 * the per-thread trace buffer set up in fmd_thread.c to trace debugging info.
 */
/*PRINTFLIKE2*/
void *
fmd_trace(uint_t tag, const char *format, ...)
{
        fmd_thread_t *tp = pthread_getspecific(fmd.d_key);
        va_list ap;
        void *trp;

        if (tp == NULL)
                return (NULL); /* drop trace record if not ready yet */

        va_start(ap, format);
        trp = tp->thr_trfunc(tp->thr_trdata, tag, format, ap);
        va_end(ap);

        return (trp);
}

const char *
fmd_ea_strerror(int err)
{
        switch (err) {
        case EXR_OK:            return ("no exacct error");
        case EXR_SYSCALL_FAIL:  return (fmd_strerror(errno));
        case EXR_CORRUPT_FILE:  return ("file corruption detected");
        case EXR_EOF:           return ("end-of-file reached");
        case EXR_NO_CREATOR:    return ("creator tag mismatch");
        case EXR_INVALID_BUF:   return ("invalid unpack buffer");
        case EXR_NOTSUPP:       return ("exacct operation not supported");
        case EXR_UNKN_VERSION:  return ("unsupported exacct file version");
        case EXR_INVALID_OBJ:   return ("invalid exacct object");
        default:                return ("unknown exacct error");
        }
}

/*
 * Create a local ENA value for fmd-generated ereports.  We use ENA Format 1
 * with the low bits of gethrtime() and pthread_self() as the processor ID.
 */
uint64_t
fmd_ena(void)
{
        hrtime_t hrt = fmd_time_gethrtime();

        return ((uint64_t)((FM_ENA_FMT1 & ENA_FORMAT_MASK) |
            ((pthread_self() << ENA_FMT1_CPUID_SHFT) & ENA_FMT1_CPUID_MASK) |
            ((hrt << ENA_FMT1_TIME_SHFT) & ENA_FMT1_TIME_MASK)));
}

/*
 * fmd_ntz32() computes the number of trailing zeroes.  The algorithm here is
 * from "Hacker's Delight" by Henry Warren, Jr.
 */
uint32_t
fmd_ntz32(uint32_t x)
{
        uint_t n = 1;

        if (x == 0)
                return (32);

        if ((x & 0xFFFF) == 0) {
                n += 16;
                x >>= 16;
        }

        if ((x & 0xFF) == 0) {
                n += 8;
                x >>= 8;
        }

        if ((x & 0xF) == 0) {
                n += 4;
                x >>= 4;
        }

        if ((x & 0x3) == 0) {
                n += 2;
                x >>= 2;
        }

        return (n - (x & 1));
}