On 19/06/17 23:44, Julien Gomes wrote:
> Add Netlink notifications on cache reports in ip6mr, in addition to the
> existing mrt6msg sent to mroute6_sk.
> Send RTM_NEWCACHEREPORT notifications to RTNLGRP_IPV6_MROUTE_R.
>
> MSGTYPE, MIF_ID, SRC_ADDR and DST_ADDR Netlink attributes contain the
> same data as their equivalent fields in the mrt6msg header.
> PKT attribute is the packet sent to mroute6_sk, without the added
> mrt6msg header.
>
> Suggested-by: Ryan Halbrook <halbr...@arista.com>
> Signed-off-by: Julien Gomes <jul...@arista.com>
> ---
> include/uapi/linux/mroute6.h | 12 ++++++++
> net/ipv6/ip6mr.c | 67
> ++++++++++++++++++++++++++++++++++++++++++--
> 2 files changed, 77 insertions(+), 2 deletions(-)
>
> diff --git a/include/uapi/linux/mroute6.h b/include/uapi/linux/mroute6.h
> index ed5721148768..e4746816c855 100644
> --- a/include/uapi/linux/mroute6.h
> +++ b/include/uapi/linux/mroute6.h
> @@ -133,4 +133,16 @@ struct mrt6msg {
> struct in6_addr im6_src, im6_dst;
> };
>
> +/* ip6mr netlink cache report attributes */
> +enum {
> + IP6MRA_CREPORT_UNSPEC,
> + IP6MRA_CREPORT_MSGTYPE,
> + IP6MRA_CREPORT_MIF_ID,
> + IP6MRA_CREPORT_SRC_ADDR,
> + IP6MRA_CREPORT_DST_ADDR,
> + IP6MRA_CREPORT_PKT,
> + __IP6MRA_CREPORT_MAX
> +};
> +#define IP6MRA_CREPORT_MAX (__IP6MRA_CREPORT_MAX - 1)
> +
> #endif /* _UAPI__LINUX_MROUTE6_H */
> diff --git a/net/ipv6/ip6mr.c b/net/ipv6/ip6mr.c
> index b0e2bf1f4212..28a1fb49f12e 100644
> --- a/net/ipv6/ip6mr.c
> +++ b/net/ipv6/ip6mr.c
> @@ -116,6 +116,7 @@ static int __ip6mr_fill_mroute(struct mr6_table *mrt,
> struct sk_buff *skb,
> struct mfc6_cache *c, struct rtmsg *rtm);
> static void mr6_netlink_event(struct mr6_table *mrt, struct mfc6_cache *mfc,
> int cmd);
> +static void mrt6msg_netlink_event(struct mr6_table *mrt, struct sk_buff
> *pkt);
> static int ip6mr_rtm_dumproute(struct sk_buff *skb,
> struct netlink_callback *cb);
> static void mroute_clean_tables(struct mr6_table *mrt, bool all);
> @@ -1125,8 +1126,7 @@ static void ip6mr_cache_resolve(struct net *net, struct
> mr6_table *mrt,
> }
>
> /*
> - * Bounce a cache query up to pim6sd. We could use netlink for this but
> pim6sd
> - * expects the following bizarre scheme.
> + * Bounce a cache query up to pim6sd and netlink.
> *
> * Called under mrt_lock.
> */
> @@ -1208,6 +1208,8 @@ static int ip6mr_cache_report(struct mr6_table *mrt,
> struct sk_buff *pkt,
> return -EINVAL;
> }
>
> + mrt6msg_netlink_event(mrt, skb);
> +
> /*
> * Deliver to user space multicast routing algorithms
> */
> @@ -2457,6 +2459,67 @@ static void mr6_netlink_event(struct mr6_table *mrt,
> struct mfc6_cache *mfc,
> rtnl_set_sk_err(net, RTNLGRP_IPV6_MROUTE, err);
> }
>
> +static void mrt6msg_netlink_event(struct mr6_table *mrt, struct sk_buff *pkt)
> +{
> + struct net *net = read_pnet(&mrt->net);
> + struct nlmsghdr *nlh;
> + struct rtgenmsg *rtgenm;
> + struct mrt6msg *msg;
> + struct sk_buff *skb;
> + struct nlattr *nla;
> + int payloadlen;
> + int msgsize;
> +
> + payloadlen = pkt->len - sizeof(struct mrt6msg);
> + msg = (struct mrt6msg *)skb_transport_header(pkt);
> + msgsize = NLMSG_ALIGN(sizeof(struct rtgenmsg))
> + + nla_total_size(1)
> + /* IP6MRA_CREPORT_MSGTYPE */
> + + nla_total_size(2)
> + /* IP6MRA_CREPORT_MIF_ID */
> + + nla_total_size(sizeof(struct in6_addr))
> + /* IP6MRA_CREPORT_SRC_ADDR */
> + + nla_total_size(sizeof(struct in6_addr))
> + /* IP6MRA_CREPORT_DST_ADDR */
> + + nla_total_size(payloadlen)
> + /* IP6MRA_CREPORT_PKT */
> + ;
Same as patch 03, this calculation could be in a separate function.
> +
> + skb = nlmsg_new(msgsize, GFP_ATOMIC);
> + if (!skb)
> + goto errout;
> +
> + nlh = nlmsg_put(skb, 0, 0, RTM_NEWCACHEREPORT,
> + sizeof(struct rtgenmsg), 0);
> + if (!nlh)
> + goto errout;
> + rtgenm = nlmsg_data(nlh);
> + rtgenm->rtgen_family = RTNL_FAMILY_IP6MR;
> + if (nla_put_u8(skb, IP6MRA_CREPORT_MSGTYPE, msg->im6_msgtype) ||
> + nla_put_u16(skb, IP6MRA_CREPORT_MIF_ID, msg->im6_mif) ||
> + nla_put_in6_addr(skb, IP6MRA_CREPORT_SRC_ADDR,
> + &msg->im6_src) ||
> + nla_put_in6_addr(skb, IP6MRA_CREPORT_DST_ADDR,
> + &msg->im6_dst))
> + goto nla_put_failure;
> +
> + nla = nla_reserve(skb, IP6MRA_CREPORT_PKT, payloadlen);
> + if (!nla || skb_copy_bits(pkt, sizeof(struct mrt6msg),
> + nla_data(nla), payloadlen))
> + goto nla_put_failure;
> +
> + nlmsg_end(skb, nlh);
> +
> + rtnl_notify(skb, net, 0, RTNLGRP_IPV6_MROUTE_R, NULL, GFP_ATOMIC);
> + return;
> +
> +nla_put_failure:
> + nlmsg_cancel(skb, nlh);
> +errout:
> + kfree_skb(skb);
> + rtnl_set_sk_err(net, RTNLGRP_IPV6_MROUTE_R, -ENOBUFS);
> +}
> +
> static int ip6mr_rtm_dumproute(struct sk_buff *skb, struct netlink_callback
> *cb)
> {
> struct net *net = sock_net(skb->sk);
>
