diff options
| -rw-r--r-- | include/net/mld.h | 5 | ||||
| -rw-r--r-- | net/ipv6/mcast.c | 41 |
2 files changed, 35 insertions, 11 deletions
diff --git a/include/net/mld.h b/include/net/mld.h index faa1d161bf24..01d751303498 100644 --- a/include/net/mld.h +++ b/include/net/mld.h @@ -88,12 +88,15 @@ struct mld2_query { #define MLDV2_QQIC_EXP(value) (((value) >> 4) & 0x07) #define MLDV2_QQIC_MAN(value) ((value) & 0x0f) +#define MLD_EXP_MIN_LIMIT 32768UL +#define MLDV1_MRD_MAX_COMPAT (MLD_EXP_MIN_LIMIT - 1) + static inline unsigned long mldv2_mrc(const struct mld2_query *mlh2) { /* RFC3810, 5.1.3. Maximum Response Code */ unsigned long ret, mc_mrc = ntohs(mlh2->mld2q_mrc); - if (mc_mrc < 32768) { + if (mc_mrc < MLD_EXP_MIN_LIMIT) { ret = mc_mrc; } else { unsigned long mc_man, mc_exp; diff --git a/net/ipv6/mcast.c b/net/ipv6/mcast.c index 592eba61e78a..9648de2b6745 100644 --- a/net/ipv6/mcast.c +++ b/net/ipv6/mcast.c @@ -1237,7 +1237,7 @@ static void mld_update_qri(struct inet6_dev *idev, } static int mld_process_v1(struct inet6_dev *idev, struct mld_msg *mld, - unsigned long *max_delay) + unsigned long *max_delay, bool v1_query) { unsigned long mldv1_md; @@ -1245,11 +1245,32 @@ static int mld_process_v1(struct inet6_dev *idev, struct mld_msg *mld, if (mld_in_v2_mode_only(idev)) return -EINVAL; - /* MLDv1 router present */ mldv1_md = ntohs(mld->mld_maxdelay); + + /* When in MLDv1 fallback and a MLDv2 router start-up being + * unaware of current MLDv1 operation, the MRC == MRD mapping + * only works when the exponential algorithm is not being + * used (as MLDv1 is unaware of such things). + * + * According to the RFC author, the MLDv2 implementations + * he's aware of all use a MRC < 32768 on start up queries. + * + * Thus, should we *ever* encounter something else larger + * than that, just assume the maximum possible within our + * reach. + */ + if (!v1_query) + mldv1_md = min(mldv1_md, MLDV1_MRD_MAX_COMPAT); + *max_delay = max(msecs_to_jiffies(mldv1_md), 1UL); - mld_set_v1_mode(idev); + /* MLDv1 router present: we need to go into v1 mode *only* + * when an MLDv1 query is received as per section 9.12. of + * RFC3810! And we know from RFC2710 section 3.7 that MLDv1 + * queries MUST be of exactly 24 octets. + */ + if (v1_query) + mld_set_v1_mode(idev); /* cancel MLDv2 report timer */ mld_gq_stop_timer(idev); @@ -1264,10 +1285,6 @@ static int mld_process_v1(struct inet6_dev *idev, struct mld_msg *mld, static int mld_process_v2(struct inet6_dev *idev, struct mld2_query *mld, unsigned long *max_delay) { - /* hosts need to stay in MLDv1 mode, discard MLDv2 queries */ - if (mld_in_v1_mode(idev)) - return -EINVAL; - *max_delay = max(msecs_to_jiffies(mldv2_mrc(mld)), 1UL); mld_update_qrv(idev, mld); @@ -1324,8 +1341,11 @@ int igmp6_event_query(struct sk_buff *skb) !(group_type&IPV6_ADDR_MULTICAST)) return -EINVAL; - if (len == MLD_V1_QUERY_LEN) { - err = mld_process_v1(idev, mld, &max_delay); + if (len < MLD_V1_QUERY_LEN) { + return -EINVAL; + } else if (len == MLD_V1_QUERY_LEN || mld_in_v1_mode(idev)) { + err = mld_process_v1(idev, mld, &max_delay, + len == MLD_V1_QUERY_LEN); if (err < 0) return err; } else if (len >= MLD_V2_QUERY_LEN_MIN) { @@ -1357,8 +1377,9 @@ int igmp6_event_query(struct sk_buff *skb) mlh2 = (struct mld2_query *)skb_transport_header(skb); mark = 1; } - } else + } else { return -EINVAL; + } read_lock_bh(&idev->lock); if (group_type == IPV6_ADDR_ANY) { |