DHCPv6 elapsed time is centiseconds, not seconds.

Start the measurement from when the first message is actually sent rather
than when DHCPv6 started.

diff --git a/common.h b/common.h
index 061e94ceb5938e6cbbf8c0092d4eca0fe9acc589..7cef0cf2a256da5a469c93a1b5f3a39972074099 100644 (file)
--- a/common.h
+++ b/common.h
@@ -56,6 +56,8 @@
 #define NSEC_PER_SEC           1000000000L
 #define NSEC_PER_MSEC          1000000L
 #define MSEC_PER_SEC           1000L
+#define CSEC_PER_SEC           100L
+#define NSEC_PER_CSEC          10000000L
 
 /* Some systems don't define timespec macros */
 #ifndef timespecclear

diff --git a/dhcp6.c b/dhcp6.c
index ead1996e6aefb8abd0b2b144be35fb6a273d2fb0..dc6378f6dc9be644cacf885cdc1e287d4328205b 100644 (file)
--- a/dhcp6.c
+++ b/dhcp6.c
@@ -300,6 +300,7 @@ dhcp6_updateelapsed(struct interface *ifp, struct dhcp6_message *m, size_t len)
        const struct dhcp6_option *co;
        struct dhcp6_option *o;
        struct timespec tv;
+       time_t hsec;
        uint16_t u16;
 
        co = dhcp6_getmoption(D6_OPTION_ELAPSED, m, len);
@@ -309,10 +310,25 @@ dhcp6_updateelapsed(struct interface *ifp, struct dhcp6_message *m, size_t len)
        o = __UNCONST(co);
        state = D6_STATE(ifp);
        clock_gettime(CLOCK_MONOTONIC, &tv);
-       timespecsub(&tv, &state->started, &tv);
-       if (tv.tv_sec < 0 || tv.tv_sec > (time_t)UINT16_MAX)
-               tv.tv_sec = (time_t)UINT16_MAX;
-       u16 = htons((uint16_t)tv.tv_sec);
+       if (state->RTC == 0) {
+               /* An RTC of zero means we're the first message
+                * out of the door, so the elapsed time is zero. */
+               state->started = tv;
+               hsec = 0;
+       } else {
+               timespecsub(&tv, &state->started, &tv);
+               /* Elapsed time is measured in centiseconds.
+                * We need to be sure it will not potentially overflow. */
+               if (tv.tv_sec >= (UINT16_MAX / CSEC_PER_SEC) + 1)
+                       hsec = UINT16_MAX;
+               else {
+                       hsec = (tv.tv_sec * CSEC_PER_SEC) +
+                           (tv.tv_nsec / NSEC_PER_CSEC);
+                       if (hsec > UINT16_MAX)
+                               hsec = UINT16_MAX;
+               }
+       }
+       u16 = htons((uint16_t)hsec);
        memcpy(D6_OPTION_DATA(o), &u16, sizeof(u16));
        return 0;
 }
@@ -1236,7 +1252,6 @@ dhcp6_startrenew(void *arg)
        ifp = arg;
        state = D6_STATE(ifp);
        state->state = DH6S_RENEW;
-       clock_gettime(CLOCK_MONOTONIC, &state->started);
        state->RTC = 0;
        state->IRT = REN_TIMEOUT;
        state->MRT = REN_MAX_RT;
@@ -1376,7 +1391,6 @@ dhcp6_startdiscover(void *arg)
        logger(ifp->ctx, LOG_INFO, "%s: soliciting a DHCPv6 lease", ifp->name);
        state = D6_STATE(ifp);
        state->state = DH6S_DISCOVER;
-       clock_gettime(CLOCK_MONOTONIC, &state->started);
        state->RTC = 0;
        state->IMD = SOL_MAX_DELAY;
        state->IRT = SOL_TIMEOUT;
@@ -1536,7 +1550,6 @@ dhcp6_startconfirm(struct interface *ifp)
 
        state = D6_STATE(ifp);
        state->state = DH6S_CONFIRM;
-       clock_gettime(CLOCK_MONOTONIC, &state->started);
        state->RTC = 0;
        state->IMD = CNF_MAX_DELAY;
        state->IRT = CNF_TIMEOUT;
@@ -1567,7 +1580,6 @@ dhcp6_startinform(void *arg)
                logger(ifp->ctx, LOG_INFO,
                    "%s: requesting DHCPv6 information", ifp->name);
        state->state = DH6S_INFORM;
-       clock_gettime(CLOCK_MONOTONIC, &state->started);
        state->RTC = 0;
        state->IMD = INF_MAX_DELAY;
        state->IRT = INF_TIMEOUT;
@@ -1622,7 +1634,6 @@ dhcp6_startrelease(struct interface *ifp)
                return;
 
        state->state = DH6S_RELEASE;
-       clock_gettime(CLOCK_MONOTONIC, &state->started);
        state->RTC = 0;
        state->IRT = REL_TIMEOUT;
        state->MRT = 0;