diff --git a/clock.c b/clock.c index 83b700e..b685bb6 100644 --- a/clock.c +++ b/clock.c @@ -576,12 +576,14 @@ struct clock *clock_create(int phc_index, struct interface *iface, int count, struct clock *c = &the_clock; char phc[32]; struct interface udsif; + struct timespec ts; memset(&udsif, 0, sizeof(udsif)); snprintf(udsif.name, sizeof(udsif.name), "%s", uds_path); udsif.transport = TRANS_UDS; - srandom(time(NULL)); + clock_gettime(CLOCK_REALTIME, &ts); + srandom(ts.tv_sec ^ ts.tv_nsec); if (c->nports) clock_destroy(c); diff --git a/makefile b/makefile index 37cbaf9..22e7d0d 100644 --- a/makefile +++ b/makefile @@ -24,9 +24,8 @@ CFLAGS = -Wall $(VER) $(incdefs) $(DEBUG) $(EXTRA_CFLAGS) LDLIBS = -lm -lrt $(EXTRA_LDFLAGS) PRG = ptp4l pmc phc2sys hwstamp_ctl OBJ = bmc.o clock.o clockadj.o clockcheck.o config.o fault.o \ - filter.o fsm.o mave.o mmedian.o msg.o phc.o pi.o port.o print.o \ - ptp4l.o raw.o servo.o sk.o stats.o tlv.o tmtab.o transport.o udp.o \ - udp6.o uds.o util.o version.o + filter.o fsm.o mave.o mmedian.o msg.o phc.o pi.o port.o print.o ptp4l.o raw.o \ + servo.o sk.o stats.o tlv.o transport.o udp.o udp6.o uds.o util.o version.o OBJECTS = $(OBJ) hwstamp_ctl.o phc2sys.o pmc.o pmc_common.o sysoff.o SRC = $(OBJECTS:.o=.c) diff --git a/port.c b/port.c index 36655d3..b382194 100644 --- a/port.c +++ b/port.c @@ -32,7 +32,6 @@ #include "print.h" #include "sk.h" #include "tlv.h" -#include "tmtab.h" #include "tmv.h" #include "util.h" @@ -80,7 +79,6 @@ struct port { UInteger16 delayreq; UInteger16 sync; } seqnum; - struct tmtab tmtab; tmv_t peer_delay; struct filter *delay_filter; int log_sync_interval; @@ -231,6 +229,29 @@ int set_tmo_lin(int fd, int seconds) return timerfd_settime(fd, 0, &tmo, NULL); } +int set_tmo_random(int fd, int min, int span, int log_seconds) +{ + uint64_t value_ns, min_ns, span_ns; + struct itimerspec tmo = { + {0, 0}, {0, 0} + }; + + if (log_seconds >= 0) { + min_ns = min * NS_PER_SEC << log_seconds; + span_ns = span * NS_PER_SEC << log_seconds; + } else { + min_ns = min * NS_PER_SEC >> -log_seconds; + span_ns = span * NS_PER_SEC >> -log_seconds; + } + + value_ns = min_ns + (span_ns * (random() % (1 << 15) + 1) >> 15); + + tmo.it_value.tv_sec = value_ns / NS_PER_SEC; + tmo.it_value.tv_nsec = value_ns % NS_PER_SEC; + + return timerfd_settime(fd, 0, &tmo, NULL); +} + static void fc_clear(struct foreign_clock *fc) { struct ptp_message *m; @@ -821,23 +842,19 @@ static void port_nrate_initialize(struct port *p) static int port_set_announce_tmo(struct port *p) { - return set_tmo_log(p->fda.fd[FD_ANNOUNCE_TIMER], - p->announceReceiptTimeout, p->logAnnounceInterval); + return set_tmo_random(p->fda.fd[FD_ANNOUNCE_TIMER], + p->announceReceiptTimeout, 1, p->logAnnounceInterval); } static int port_set_delay_tmo(struct port *p) { - struct itimerspec tmo = { - {0, 0}, {0, 0} - }; - int index; if (p->delayMechanism == DM_P2P) { return set_tmo_log(p->fda.fd[FD_DELAY_TIMER], 1, p->logMinPdelayReqInterval); + } else { + return set_tmo_random(p->fda.fd[FD_DELAY_TIMER], 0, 2, + p->logMinDelayReqInterval); } - index = random() % TMTAB_MAX; - tmo.it_value = p->tmtab.ts[index]; - return timerfd_settime(p->fda.fd[FD_DELAY_TIMER], 0, &tmo, NULL); } static int port_set_manno_tmo(struct port *p) @@ -1342,8 +1359,6 @@ static int port_initialize(struct port *p) p->logMinPdelayReqInterval = p->pod.logMinPdelayReqInterval; p->neighborPropDelayThresh = p->pod.neighborPropDelayThresh; - tmtab_init(&p->tmtab, 1 + p->logMinDelayReqInterval); - for (i = 0; i < N_TIMER_FDS; i++) { fd[i] = -1; } @@ -1549,7 +1564,6 @@ static void process_delay_resp(struct port *p, struct ptp_message *m) p->logMinDelayReqInterval = rsp->hdr.logMessageInterval; pr_notice("port %hu: minimum delay request interval 2^%d", portnum(p), p->logMinDelayReqInterval); - tmtab_init(&p->tmtab, 1 + p->logMinDelayReqInterval); } } diff --git a/port.h b/port.h index 5fef028..e781f24 100644 --- a/port.h +++ b/port.h @@ -173,6 +173,21 @@ enum port_state port_state(struct port *port); */ int set_tmo_log(int fd, unsigned int scale, int log_seconds); +/** + * Utility function for setting a file descriptor timer. + * + * This function sets the timer 'fd' to a random value between M * 2^N and + * (M + S) * 2^N, where M is the value of the 'min' parameter, S is the value + * of the 'span' parameter, and N in the value of the 'log_seconds' parameter. + * + * @param fd A file descriptor previously opened with timerfd_create(2). + * @param min The minimum value for the timer. + * @param span The span value for the timer. Must be a positive value. + * @param log_seconds The exponential factor for the timer. + * @return Zero on success, non-zero otherwise. + */ +int set_tmo_random(int fd, int min, int span, int log_seconds); + /** * Utility function for setting or resetting a file descriptor timer. * diff --git a/tmtab.c b/tmtab.c deleted file mode 100644 index 7fa9f50..0000000 --- a/tmtab.c +++ /dev/null @@ -1,54 +0,0 @@ -/** - * @file tmtab.c - * @note Copyright (C) 2011 Richard Cochran - * - * This program 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 of the License, or - * (at your option) any later version. - * - * This program 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; if not, write to the Free Software Foundation, Inc., - * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. - */ -#include "tmtab.h" -#include "tmv.h" - -void tmtab_init(struct tmtab *tt, int log_seconds) -{ - int i; - struct timespec incr, ts = {0, 0}; - uint64_t max, min; - - if (log_seconds < 0) { - log_seconds *= -1; - for (i = 1, max = 500000000ULL; i < log_seconds; i++) { - max >>= 1; - } - } else { - for (i = 0, max = 1000000000ULL; i < log_seconds; i++) { - max <<= 1; - } - } - - min = max / (TMTAB_MAX - 1ULL); - - incr.tv_sec = min / 1000000000ULL; - incr.tv_nsec = min % 1000000000ULL; - - for (i = 0; i < TMTAB_MAX; i++) { - ts.tv_sec += incr.tv_sec; - ts.tv_nsec += incr.tv_nsec; - while (ts.tv_nsec >= NS_PER_SEC) { - ts.tv_nsec -= NS_PER_SEC; - ts.tv_sec++; - } - tt->ts[i] = ts; - } -} - diff --git a/tmtab.h b/tmtab.h deleted file mode 100644 index 9b80cc6..0000000 --- a/tmtab.h +++ /dev/null @@ -1,56 +0,0 @@ -/** - * @file tmtab.h - * @brief Implements a table of time out values. - * @note Copyright (C) 2011 Richard Cochran - * - * This program 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 of the License, or - * (at your option) any later version. - * - * This program 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; if not, write to the Free Software Foundation, Inc., - * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. - */ -#ifndef HAVE_TMTAB_H -#define HAVE_TMTAB_H - -#include - -/* - * Let 'D' be the logMinDelayReqInterval - * and 'S' be the logSyncInterval. - * - * The delay request interval ranges from zero to 2^{D+1} seconds. - * The standard requires that - * - * S <= D <= S+5 - * - * and the timeout granularity not more than 2^{S-4} seconds. - * Thus, the minimum required number of grains is given by - * - * 2^{D+1} / 2^{S-4} = 2^{D-S+5} - * - * and finds a minimum of 2^5 and a maximum of 2^10. - * - * The timeout table allows for the maximum number of grains required. - * - * Note that the table is made to be biased so that when sampling the - * table randomly, the average delay value will be slightly larger - * than logMinDelayReqInterval, in order to satisfy the wording of the - * standard. - */ -#define TMTAB_MAX 1024 - -struct tmtab { - struct timespec ts[TMTAB_MAX]; -}; - -void tmtab_init(struct tmtab *tt, int log_seconds); - -#endif