ipmr: add netlink notifications on igmpmsg cache reports

Add Netlink notifications on cache reports in ipmr, in addition to the
existing igmpmsg sent to mroute_sk.
Send RTM_NEWCACHEREPORT notifications to RTNLGRP_IPV4_MROUTE_R.

MSGTYPE, VIF_ID, SRC_ADDR and DST_ADDR Netlink attributes contain the
same data as their equivalent fields in the igmpmsg header.
PKT attribute is the packet sent to mroute_sk, without the added igmpmsg
header.

Suggested-by: Ryan Halbrook <halbrook@arista.com>
Signed-off-by: Julien Gomes <julien@arista.com>
Reviewed-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Julien Gomes 2017-06-20 13:54:17 -07:00 committed by David S. Miller
parent 5f729eaabe
commit 5a645dd86c
2 changed files with 79 additions and 2 deletions

View File

@ -152,6 +152,18 @@ enum {
};
#define IPMRA_VIFA_MAX (__IPMRA_VIFA_MAX - 1)
/* ipmr netlink cache report attributes */
enum {
IPMRA_CREPORT_UNSPEC,
IPMRA_CREPORT_MSGTYPE,
IPMRA_CREPORT_VIF_ID,
IPMRA_CREPORT_SRC_ADDR,
IPMRA_CREPORT_DST_ADDR,
IPMRA_CREPORT_PKT,
__IPMRA_CREPORT_MAX
};
#define IPMRA_CREPORT_MAX (__IPMRA_CREPORT_MAX - 1)
/* That's all usermode folks */
#define MFC_ASSERT_THRESH (3*HZ) /* Maximal freq. of asserts */

View File

@ -109,6 +109,7 @@ static int __ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
struct mfc_cache *c, struct rtmsg *rtm);
static void mroute_netlink_event(struct mr_table *mrt, struct mfc_cache *mfc,
int cmd);
static void igmpmsg_netlink_event(struct mr_table *mrt, struct sk_buff *pkt);
static void mroute_clean_tables(struct mr_table *mrt, bool all);
static void ipmr_expire_process(unsigned long arg);
@ -995,8 +996,7 @@ static void ipmr_cache_resolve(struct net *net, struct mr_table *mrt,
}
}
/* Bounce a cache query up to mrouted. We could use netlink for this but mrouted
* expects the following bizarre scheme.
/* Bounce a cache query up to mrouted and netlink.
*
* Called under mrt_lock.
*/
@ -1062,6 +1062,8 @@ static int ipmr_cache_report(struct mr_table *mrt,
return -EINVAL;
}
igmpmsg_netlink_event(mrt, skb);
/* Deliver to mrouted */
ret = sock_queue_rcv_skb(mroute_sk, skb);
rcu_read_unlock();
@ -2341,6 +2343,69 @@ errout:
rtnl_set_sk_err(net, RTNLGRP_IPV4_MROUTE, err);
}
static size_t igmpmsg_netlink_msgsize(size_t payloadlen)
{
size_t len =
NLMSG_ALIGN(sizeof(struct rtgenmsg))
+ nla_total_size(1) /* IPMRA_CREPORT_MSGTYPE */
+ nla_total_size(4) /* IPMRA_CREPORT_VIF_ID */
+ nla_total_size(4) /* IPMRA_CREPORT_SRC_ADDR */
+ nla_total_size(4) /* IPMRA_CREPORT_DST_ADDR */
/* IPMRA_CREPORT_PKT */
+ nla_total_size(payloadlen)
;
return len;
}
static void igmpmsg_netlink_event(struct mr_table *mrt, struct sk_buff *pkt)
{
struct net *net = read_pnet(&mrt->net);
struct nlmsghdr *nlh;
struct rtgenmsg *rtgenm;
struct igmpmsg *msg;
struct sk_buff *skb;
struct nlattr *nla;
int payloadlen;
payloadlen = pkt->len - sizeof(struct igmpmsg);
msg = (struct igmpmsg *)skb_network_header(pkt);
skb = nlmsg_new(igmpmsg_netlink_msgsize(payloadlen), 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_IPMR;
if (nla_put_u8(skb, IPMRA_CREPORT_MSGTYPE, msg->im_msgtype) ||
nla_put_u32(skb, IPMRA_CREPORT_VIF_ID, msg->im_vif) ||
nla_put_in_addr(skb, IPMRA_CREPORT_SRC_ADDR,
msg->im_src.s_addr) ||
nla_put_in_addr(skb, IPMRA_CREPORT_DST_ADDR,
msg->im_dst.s_addr))
goto nla_put_failure;
nla = nla_reserve(skb, IPMRA_CREPORT_PKT, payloadlen);
if (!nla || skb_copy_bits(pkt, sizeof(struct igmpmsg),
nla_data(nla), payloadlen))
goto nla_put_failure;
nlmsg_end(skb, nlh);
rtnl_notify(skb, net, 0, RTNLGRP_IPV4_MROUTE_R, NULL, GFP_ATOMIC);
return;
nla_put_failure:
nlmsg_cancel(skb, nlh);
errout:
kfree_skb(skb);
rtnl_set_sk_err(net, RTNLGRP_IPV4_MROUTE_R, -ENOBUFS);
}
static int ipmr_rtm_dumproute(struct sk_buff *skb, struct netlink_callback *cb)
{
struct net *net = sock_net(skb->sk);