From fdd68bea0e12d92e6afb245364fba13c3f8b499b Mon Sep 17 00:00:00 2001 From: alfred Date: Sat, 27 Jul 2013 20:47:01 +0000 Subject: Fix watchdog pretimeout. The original API calls for pow2ns, however the new APIs from Linux call for seconds. We need to be able to convert to/from 2^Nns to seconds in both userland and kernel to fix this and properly compare units. --- usr.sbin/watchdogd/watchdogd.c | 196 +++++++++++++++++++++++++++++++++++++---- 1 file changed, 179 insertions(+), 17 deletions(-) (limited to 'usr.sbin/watchdogd') diff --git a/usr.sbin/watchdogd/watchdogd.c b/usr.sbin/watchdogd/watchdogd.c index 5416751..7b6db94 100644 --- a/usr.sbin/watchdogd/watchdogd.c +++ b/usr.sbin/watchdogd/watchdogd.c @@ -39,6 +39,7 @@ __FBSDID("$FreeBSD$"); #include #include #include +#include #include #include @@ -58,19 +59,24 @@ __FBSDID("$FreeBSD$"); #include +static long fetchtimeout(int opt, const char *longopt, const char *myoptarg); static void parseargs(int, char *[]); +static int seconds_to_pow2ns(int); static void sighandler(int); static void watchdog_loop(void); static int watchdog_init(void); static int watchdog_onoff(int onoff); static int watchdog_patpat(u_int timeout); static void usage(void); +static int tstotv(struct timeval *tv, struct timespec *ts); +static int tvtohz(struct timeval *tv); static int debugging = 0; static int end_program = 0; static const char *pidfile = _PATH_VARRUN "watchdogd.pid"; static u_int timeout = WD_TO_128SEC; static u_int pretimeout = 0; +static u_int timeout_sec; static u_int passive = 0; static int is_daemon = 0; static int is_dry_run = 0; /* do not arm the watchdog, only @@ -183,6 +189,59 @@ main(int argc, char *argv[]) } } +static void +pow2ns_to_ts(int pow2ns, struct timespec *ts) +{ + uint64_t ns; + + ns = 1ULL << pow2ns; + ts->tv_sec = ns / 1000000000ULL; + ts->tv_nsec = ns % 1000000000ULL; +} + +/* + * Convert a timeout in seconds to N where 2^N nanoseconds is close to + * "seconds". + * + * The kernel expects the timeouts for watchdogs in "2^N nanosecond format". + */ +static u_int +parse_timeout_to_pow2ns(char opt, const char *longopt, const char *myoptarg) +{ + double a; + u_int rv; + struct timespec ts; + struct timeval tv; + int ticks; + char shortopt[] = "- "; + + if (!longopt) + shortopt[1] = opt; + + a = fetchtimeout(opt, longopt, myoptarg); + + if (a == 0) + rv = WD_TO_NEVER; + else + rv = seconds_to_pow2ns(a); + pow2ns_to_ts(rv, &ts); + tstotv(&tv, &ts); + ticks = tvtohz(&tv); + if (debugging) { + printf("Timeout for %s%s " + "is 2^%d nanoseconds " + "(in: %s sec -> out: %ld sec %ld ns -> %d ticks)\n", + longopt ? "-" : "", longopt ? longopt : shortopt, + rv, + myoptarg, ts.tv_sec, ts.tv_nsec, ticks); + } + if (ticks <= 0) { + errx(1, "Timeout for %s%s is too small, please choose a higher timeout.", longopt ? "-" : "", longopt ? longopt : shortopt); + } + + return (rv); +} + /* * Catch signals and begin shutdown process. */ @@ -513,6 +572,110 @@ timeout_act_str2int(const char *lopt, const char *acts) return rv; } +int +tstotv(struct timeval *tv, struct timespec *ts) +{ + + tv->tv_sec = ts->tv_sec; + tv->tv_usec = ts->tv_nsec / 1000; + return 0; +} + +/* + * Convert a timeval to a number of ticks. + * Mostly copied from the kernel. + */ +int +tvtohz(struct timeval *tv) +{ + register unsigned long ticks; + register long sec, usec; + int hz; + size_t hzsize; + int error; + int tick; + + hzsize = sizeof(hz); + + error = sysctlbyname("kern.hz", &hz, &hzsize, NULL, 0); + if (error) + err(1, "sysctlbyname kern.hz"); + + tick = 1000000 / hz; + + /* + * If the number of usecs in the whole seconds part of the time + * difference fits in a long, then the total number of usecs will + * fit in an unsigned long. Compute the total and convert it to + * ticks, rounding up and adding 1 to allow for the current tick + * to expire. Rounding also depends on unsigned long arithmetic + * to avoid overflow. + * + * Otherwise, if the number of ticks in the whole seconds part of + * the time difference fits in a long, then convert the parts to + * ticks separately and add, using similar rounding methods and + * overflow avoidance. This method would work in the previous + * case but it is slightly slower and assumes that hz is integral. + * + * Otherwise, round the time difference down to the maximum + * representable value. + * + * If ints have 32 bits, then the maximum value for any timeout in + * 10ms ticks is 248 days. + */ + sec = tv->tv_sec; + usec = tv->tv_usec; + if (usec < 0) { + sec--; + usec += 1000000; + } + if (sec < 0) { +#ifdef DIAGNOSTIC + if (usec > 0) { + sec++; + usec -= 1000000; + } + printf("tvotohz: negative time difference %ld sec %ld usec\n", + sec, usec); +#endif + ticks = 1; + } else if (sec <= LONG_MAX / 1000000) + ticks = (sec * 1000000 + (unsigned long)usec + (tick - 1)) + / tick + 1; + else if (sec <= LONG_MAX / hz) + ticks = sec * hz + + ((unsigned long)usec + (tick - 1)) / tick + 1; + else + ticks = LONG_MAX; + if (ticks > INT_MAX) + ticks = INT_MAX; + return ((int)ticks); +} + +static int +seconds_to_pow2ns(int seconds) +{ + uint64_t power; + uint64_t ns; + uint64_t shifted; + + if (seconds <= 0) + errx(1, "seconds %d < 0", seconds); + ns = ((uint64_t)seconds) * 1000000000ULL; + power = flsll(ns); + shifted = 1ULL << power; + if (shifted <= ns) { + power++; + } + if (debugging) { + printf("shifted %lld\n", (long long)shifted); + printf("seconds_to_pow2ns: seconds: %d, ns %lld, power %d\n", + seconds, (long long)ns, (int)power); + } + return (power); +} + + /* * Handle the few command line arguments supported. */ @@ -521,9 +684,7 @@ parseargs(int argc, char *argv[]) { int longindex; int c; - char *p; const char *lopt; - double a; /* * if we end with a 'd' aka 'watchdogd' then we are the daemon program, @@ -565,21 +726,11 @@ parseargs(int argc, char *argv[]) do_syslog = 0; break; case 't': - p = NULL; - errno = 0; - a = strtod(optarg, &p); - if ((p != NULL && *p != '\0') || errno != 0) - errx(EX_USAGE, "-t argument is not a number"); - if (a < 0) - errx(EX_USAGE, "-t argument must be positive"); - - if (a == 0) - timeout = WD_TO_NEVER; - else - timeout = flsll(a * 1e9); - if (debugging) - printf("Timeout is 2^%d nanoseconds\n", - timeout); + timeout_sec = atoi(optarg); + timeout = parse_timeout_to_pow2ns(c, NULL, optarg); + if (debugging) + printf("Timeout is 2^%d nanoseconds\n", + timeout); break; case 'T': carp_thresh_seconds = fetchtimeout(c, "NULL", optarg); @@ -618,4 +769,15 @@ parseargs(int argc, char *argv[]) errx(EX_USAGE, "extra arguments."); if (is_daemon && timeout < WD_TO_1SEC) errx(EX_USAGE, "-t argument is less than one second."); + if (pretimeout_set) { + struct timespec ts; + + pow2ns_to_ts(timeout, &ts); + if (pretimeout >= ts.tv_sec) { + errx(EX_USAGE, + "pretimeout (%d) >= timeout (%d -> %ld)\n" + "see manual section TIMEOUT RESOLUTION", + pretimeout, timeout_sec, (long)ts.tv_sec); + } + } } -- cgit v1.1