+static void mld_set_v1_mode(struct inet6_dev *idev)
+{
+ /* RFC3810, relevant sections:
+ * - 9.1. Robustness Variable
+ * - 9.2. Query Interval
+ * - 9.3. Query Response Interval
+ * - 9.12. Older Version Querier Present Timeout
+ */
+ unsigned long switchback;
+
+ switchback = (idev->mc_qrv * idev->mc_qi) + idev->mc_qri;
+
+ idev->mc_v1_seen = jiffies + switchback;
+}
+
+static void mld_update_qrv(struct inet6_dev *idev,
+ const struct mld2_query *mlh2)
+{
+ /* RFC3810, relevant sections:
+ * - 5.1.8. QRV (Querier's Robustness Variable)
+ * - 9.1. Robustness Variable
+ */
+
+ /* The value of the Robustness Variable MUST NOT be zero,
+ * and SHOULD NOT be one. Catch this here if we ever run
+ * into such a case in future.
+ */
+ WARN_ON(idev->mc_qrv == 0);
+
+ if (mlh2->mld2q_qrv > 0)
+ idev->mc_qrv = mlh2->mld2q_qrv;
+
+ if (unlikely(idev->mc_qrv < 2)) {
+ net_warn_ratelimited("IPv6: MLD: clamping QRV from %u to %u!\n",
+ idev->mc_qrv, MLD_QRV_DEFAULT);
+ idev->mc_qrv = MLD_QRV_DEFAULT;
+ }
+}
+
+static void mld_update_qi(struct inet6_dev *idev,
+ const struct mld2_query *mlh2)
+{
+ /* RFC3810, relevant sections:
+ * - 5.1.9. QQIC (Querier's Query Interval Code)
+ * - 9.2. Query Interval
+ * - 9.12. Older Version Querier Present Timeout
+ * (the [Query Interval] in the last Query received)
+ */
+ unsigned long mc_qqi;
+
+ if (mlh2->mld2q_qqic < 128) {
+ mc_qqi = mlh2->mld2q_qqic;
+ } else {
+ unsigned long mc_man, mc_exp;
+
+ mc_exp = MLDV2_QQIC_EXP(mlh2->mld2q_qqic);
+ mc_man = MLDV2_QQIC_MAN(mlh2->mld2q_qqic);
+
+ mc_qqi = (mc_man | 0x10) << (mc_exp + 3);
+ }
+
+ idev->mc_qi = mc_qqi * HZ;
+}
+
+static void mld_update_qri(struct inet6_dev *idev,
+ const struct mld2_query *mlh2)
+{
+ /* RFC3810, relevant sections:
+ * - 5.1.3. Maximum Response Code
+ * - 9.3. Query Response Interval
+ */
+ unsigned long mc_qri, mc_mrc = ntohs(mlh2->mld2q_mrc);
+
+ if (mc_mrc < 32768) {
+ mc_qri = mc_mrc;
+ } else {
+ unsigned long mc_man, mc_exp;
+
+ mc_exp = MLDV2_MRC_EXP(mc_mrc);
+ mc_man = MLDV2_MRC_MAN(mc_mrc);
+
+ mc_qri = (mc_man | 0x1000) << (mc_exp + 3);
+ }
+
+ idev->mc_qri = msecs_to_jiffies(mc_qri);
+}
+