/*

 * SPDX-License-Identifier: ISC

 *

 * Copyright (c) 2009-2020 Todd C. Miller <Todd.Miller@sudo.ws>

 *

 * Permission to use, copy, modify, and distribute this software for any

 * purpose with or without fee is hereby granted, provided that the above

 * copyright notice and this permission notice appear in all copies.

 *

 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES

 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF

 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR

 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES

 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN

 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF

 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

 */

#include <config.h>

#include <stdio.h>

#include <stdlib.h>

#ifdef HAVE_STDBOOL_H

# include <stdbool.h>

#else

# include <compat/stdbool.h>

#endif /* HAVE_STDBOOL_H */

#include <string.h>

#include <signal.h>

#include <unistd.h>

#include <ctype.h>

#include <errno.h>

#include <limits.h>

#include <fcntl.h>

#include <time.h>

#include <sudo_compat.h>

#include <sudo_debug.h>

#include <sudo_eventlog.h>

#include <sudo_fatal.h>

#include <sudo_gettext.h>

#include <sudo_iolog.h>

#include <sudo_util.h>

static int timing_event_adj;

void

iolog_adjust_delay(struct timespec *delay, struct timespec *max_delay,

     double scale_factor)

{

    debug_decl(iolog_adjust_delay, SUDO_DEBUG_UTIL);

    /* Avoid division by zero or negative delays. */

    if (scale_factor <= 0.0) {

  sudo_timespecclear(delay);

  debug_return;

    }

    if (scale_factor != 1.0) {

  /* Order is important: we don't want to double the remainder. */

  const double seconds = (double)delay->tv_sec / scale_factor;

  const double nseconds = (double)delay->tv_nsec / scale_factor;

        delay->tv_sec = (time_t)seconds;

        delay->tv_nsec = (long)nseconds;

        delay->tv_nsec += (long)((seconds - (double)delay->tv_sec) * 1000000000);

        while (delay->tv_nsec >= 1000000000) {

            delay->tv_sec++;

            delay->tv_nsec -= 1000000000;

        }

    }

    /* Clamp to max delay. */

    if (max_delay != NULL) {

  if (sudo_timespeccmp(delay, max_delay, >)) {

      delay->tv_sec = max_delay->tv_sec;

      delay->tv_nsec = max_delay->tv_nsec;

  }

    }

    debug_return;

}

/*

 * Parse the delay as seconds and nanoseconds: %lld.%09ld

 * Sudo used to write this as a double, but since timing data is logged

 * in the C locale this may not match the current locale.

 */

char *

iolog_parse_delay(const char *cp, struct timespec *delay,

    const char *decimal_point)

{

    char numbuf[STRLEN_MAX_SIGNED(long long) + 1];

    const char *errstr, *ep;

    long long llval;

    size_t len;

    debug_decl(iolog_parse_delay, SUDO_DEBUG_UTIL);

    /* Parse seconds (whole number portion). */

    for (ep = cp; isdigit((unsigned char)*ep); ep++)

  continue;

    len = (size_t)(ep - cp);

    if (len >= sizeof(numbuf)) {

  sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,

      "%s: number of seconds is too large", cp);

  debug_return_ptr(NULL);

    }

    memcpy(numbuf, cp, len);

    numbuf[len] = '\0';

    delay->tv_sec = (time_t)sudo_strtonum(numbuf, 0, TIME_T_MAX, &errstr);

    if (errstr != NULL) {

  sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,

      "%s: number of seconds is %s", numbuf, errstr);

  debug_return_ptr(NULL);

    }

    /* Radix may be in user's locale for sudo < 1.7.4 so accept that too. */

    if (*ep != '.' && *ep != *decimal_point) {

  if (*ep == '\0' || isspace((unsigned char)*ep)) {

      /* No fractional part. */

      delay->tv_nsec = 0;

      goto done;

  }

  sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,

      "invalid characters after seconds: %s", ep);

  debug_return_ptr(NULL);

    }

    cp = ep + 1;

    /* Parse fractional part, we may read more precision than we can store. */

    for (ep = cp; isdigit((unsigned char)*ep); ep++)

  continue;

    len = (size_t)(ep - cp);

    if (len >= sizeof(numbuf)) {

  sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,

      "%s: number of nanoseconds is too large", cp);

  debug_return_ptr(NULL);

    }

    memcpy(numbuf, cp, len);

    numbuf[len] = '\0';

    llval = sudo_strtonum(numbuf, 0, LLONG_MAX, &errstr);

    if (errstr != NULL) {

  sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,

      "%s: number of nanoseconds is %s", numbuf, errstr);

  debug_return_ptr(NULL);

    }

    /* Adjust fractional part to nanosecond precision. */

    if (len < 9) {

  /* Convert to nanosecond precision. */

  do {

      llval *= 10;

  } while (++len < 9);

    } else if (len > 9) {

  /* Clamp to nanoseconds. */

  do {

      llval /= 10;

  } while (--len > 9);

    }

    delay->tv_nsec = (long)llval;

done:

    /* Advance to the next field. */

    while (isspace((unsigned char)*ep))

  ep++;

    debug_return_str((char *)ep);

}

/*

 * Parse a timing line, which is formatted as:

 *  IO_EVENT_TTYOUT sleep_time num_bytes

 *  IO_EVENT_WINSIZE sleep_time lines cols

 *  IO_EVENT_SUSPEND sleep_time signo

 * Where type is IO_EVENT_*, sleep_time is the number of seconds to sleep

 * before writing the data and num_bytes is the number of bytes to output.

 * Returns true on success and false on failure.

 */

bool

iolog_parse_timing(const char *line, struct timing_closure *timing)

{

    unsigned long ulval;

    char *cp, *ep;

    debug_decl(iolog_parse_timing, SUDO_DEBUG_UTIL);

    /* Clear iolog descriptor. */

    timing->iol = NULL;

    /* Parse event type. */

    ulval = strtoul(line, &ep, 10);

    if (ep == line || !isspace((unsigned char) *ep))

  goto bad;

    if (ulval >= IO_EVENT_COUNT)

  goto bad;

    if (ulval == IO_EVENT_TTYOUT_1_8_7) {

  /* work around a bug in timing files generated by sudo 1.8.7 */

  timing_event_adj = 2;

    }

    timing->event = (int)ulval - timing_event_adj;

    for (cp = ep + 1; isspace((unsigned char) *cp); cp++)

  continue;

    /* Parse delay, returns the next field or NULL on error. */

    if ((cp = iolog_parse_delay(cp, &timing->delay, timing->decimal)) == NULL)

  goto bad;

    switch (timing->event) {

    case IO_EVENT_SUSPEND:

  /* Signal name (no leading SIG prefix) or number. */

  if (str2sig(cp, &timing->u.signo) == -1)

      goto bad;

  break;

    case IO_EVENT_WINSIZE:

  ulval = strtoul(cp, &ep, 10);

  if (ep == cp || !isspace((unsigned char) *ep))

      goto bad;

  if (ulval > INT_MAX)

      goto bad;

  timing->u.winsize.lines = (int)ulval;

  for (cp = ep + 1; isspace((unsigned char) *cp); cp++)

      continue;

  ulval = strtoul(cp, &ep, 10);

  if (ep == cp || *ep != '\0')

      goto bad;

  if (ulval > INT_MAX)

      goto bad;

  timing->u.winsize.cols = (int)ulval;

  break;

    default:

  errno = 0;

  ulval = strtoul(cp, &ep, 10);

  if (ep == cp || *ep != '\0')

      goto bad;

  /* Note: assumes SIZE_MAX == ULONG_MAX */

  if (errno == ERANGE && ulval == ULONG_MAX)

      goto bad;

  timing->u.nbytes = (size_t)ulval;

  break;

    }

    debug_return_bool(true);

bad:

    debug_return_bool(false);

}

/*

 * Read the next record from the timing file.

 * Return 0 on success, 1 on EOF and -1 on error.

 */

int

iolog_read_timing_record(struct iolog_file *iol, struct timing_closure *timing)

{

    char line[LINE_MAX];

    const char *errstr;

    char *nl;

    debug_decl(iolog_read_timing_record, SUDO_DEBUG_UTIL);

    /* Read next record from timing file. */

    if (iolog_gets(iol, line, sizeof(line), &errstr) == NULL) {

  /* EOF or error reading timing file, we are done. */

  if (iolog_eof(iol))

      debug_return_int(1);

  sudo_warnx(U_("error reading timing file: %s"), errstr);

  debug_return_int(-1);

    }

    /*

     * All timing file records must end with a newline.

     * A missing newline may indicate a line longer than LINE_MAX.

     */

    nl = strchr(line, '\n');

    if (nl == NULL) {

  goto invalid;

    }

    *nl = '\0';

    /* Parse timing file record. */

    if (!iolog_parse_timing(line, timing)) {

  goto invalid;

    }

    debug_return_int(0);

invalid:

    /* Truncate invalid timing file line at 128 bytes. */

    line[128] = '\0';

    sudo_warnx(U_("invalid timing file line: %s"), line);

    debug_return_int(-1);

}