On 7/03/19 9:20 AM, Brodie Greenfield wrote:
> We want to be able to keep more spaces available in our queue for
> processing incoming IPv6 multicast traffic (adding (S,G) entries) - this
> lets us learn more groups faster, rather than dropping them at this stage.
>
> Signed-off-by: Brodie Greenfield <brodie.greenfi...@alliedtelesis.co.nz>
> ---
> Documentation/networking/ip-sysctl.txt | 8 ++++++++
> include/net/netns/ipv6.h | 1 +
> net/ipv6/af_inet6.c | 1 +
> net/ipv6/ip6mr.c | 4 +++-
> net/ipv6/sysctl_net_ipv6.c | 7 +++++++
> 5 files changed, 20 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/networking/ip-sysctl.txt
> b/Documentation/networking/ip-sysctl.txt
> index 02f77e932adf..68eada3ca915 100644
> --- a/Documentation/networking/ip-sysctl.txt
> +++ b/Documentation/networking/ip-sysctl.txt
> @@ -1481,6 +1481,14 @@ skip_notify_on_dev_down - BOOLEAN
> on userspace caches to track link events and evict routes.
> Default: false (generate message)
>
> +ip_mr_cache_queue_length - INTEGER
Should be "ip6_mr_cache_queue_length" for this patch.
> + Limit the number of multicast packets we can have in the queue to be
> + resolved.
> + Bear in mind that when an unresolved multicast packet is received,
> + there is an O(n) traversal of the queue. This should be considered
> + if increasing.
> + Default: 10
> +
> IPv6 Fragmentation:
>
> ip6frag_high_thresh - INTEGER
> diff --git a/include/net/netns/ipv6.h b/include/net/netns/ipv6.h
> index ef1ed529f33c..84b58424c799 100644
> --- a/include/net/netns/ipv6.h
> +++ b/include/net/netns/ipv6.h
> @@ -46,6 +46,7 @@ struct netns_sysctl_ipv6 {
> int max_hbh_opts_len;
> int seg6_flowlabel;
> bool skip_notify_on_dev_down;
> + unsigned int ip6_mr_cache_queue_length;
> };
>
> struct netns_ipv6 {
> diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c
> index d99753b5e39b..6551bb63e5a2 100644
> --- a/net/ipv6/af_inet6.c
> +++ b/net/ipv6/af_inet6.c
> @@ -856,6 +856,7 @@ static int __net_init inet6_net_init(struct net *net)
> net->ipv6.sysctl.max_hbh_opts_cnt = IP6_DEFAULT_MAX_HBH_OPTS_CNT;
> net->ipv6.sysctl.max_dst_opts_len = IP6_DEFAULT_MAX_DST_OPTS_LEN;
> net->ipv6.sysctl.max_hbh_opts_len = IP6_DEFAULT_MAX_HBH_OPTS_LEN;
> + net->ipv6.sysctl.ip6_mr_cache_queue_length = 10;
> atomic_set(&net->ipv6.fib6_sernum, 1);
>
> err = ipv6_init_mibs(net);
> diff --git a/net/ipv6/ip6mr.c b/net/ipv6/ip6mr.c
> index cc01aa3f2b5e..bb445871437e 100644
> --- a/net/ipv6/ip6mr.c
> +++ b/net/ipv6/ip6mr.c
> @@ -1135,6 +1135,7 @@ static int ip6mr_cache_report(struct mr_table *mrt,
> struct sk_buff *pkt,
> static int ip6mr_cache_unresolved(struct mr_table *mrt, mifi_t mifi,
> struct sk_buff *skb, struct net_device *dev)
> {
> + struct net *net = dev_net(dev);
> struct mfc6_cache *c;
> bool found = false;
> int err;
> @@ -1153,7 +1154,8 @@ static int ip6mr_cache_unresolved(struct mr_table *mrt,
> mifi_t mifi,
> * Create a new entry if allowable
> */
>
> - if (atomic_read(&mrt->cache_resolve_queue_len) >= 10 ||
> + if (atomic_read(&mrt->cache_resolve_queue_len) >=
> + net->ipv6.sysctl.ip6_mr_cache_queue_length ||
> (c = ip6mr_cache_alloc_unres()) == NULL) {
> spin_unlock_bh(&mfc_unres_lock);
>
> diff --git a/net/ipv6/sysctl_net_ipv6.c b/net/ipv6/sysctl_net_ipv6.c
> index e15cd37024fd..a27299d4cc34 100644
> --- a/net/ipv6/sysctl_net_ipv6.c
> +++ b/net/ipv6/sysctl_net_ipv6.c
> @@ -159,6 +159,13 @@ static struct ctl_table ipv6_table_template[] = {
> .mode = 0644,
> .proc_handler = proc_dointvec
> },
> + {
> + .procname = "ip6_mr_cache_queue_length",
> + .data =
> &init_net.ipv6.sysctl.ip6_mr_cache_queue_length,
> + .maxlen = sizeof(int),
> + .mode = 0644,
> + .proc_handler = proc_dointvec
> + },
> { }
> };
>
>
