[PATCH net-next 0/3] ipmr/ip6mr: add Netlink notifications on cache reports

[PATCH net-next 0/3] ipmr/ip6mr: add Netlink notifications on cache reports

[Julien Gomes]

Currently, all ipmr/ip6mr cache reports are sent through the
mroute/mroute6 socket only.
This forces the use of a single socket for mroute programming, cache
reports and, regarding ipmr, IGMP messages without Router Alert option
reception.

The present patches are aiming to send Netlink notifications in addition
to the existing igmpmsg/mrt6msg to give user programs a way to handle
cache reports in parallel with multiple sockets other than the
mroute/mroute6 socket.

Julien Gomes (3):
  rtnetlink: add NEWCACHEREPORT message type
  ipmr: add netlink notifications on igmpmsg cache reports
  ip6mr: add netlink notifications on mrt6msg cache reports

 include/uapi/linux/mroute.h    | 11 ++++++++
 include/uapi/linux/mroute6.h   | 11 ++++++++
 include/uapi/linux/rtnetlink.h |  3 ++
 net/ipv4/ipmr.c                | 63 ++++++++++++++++++++++++++++++++++++++++--
 net/ipv6/ip6mr.c               | 63 ++++++++++++++++++++++++++++++++++++++++--
 security/selinux/nlmsgtab.c    |  3 +-
 6 files changed, 149 insertions(+), 5 deletions(-)

-- 
2.13.1

[PATCH net-next 1/3] rtnetlink: add NEWCACHEREPORT message type

[Julien Gomes]

New NEWCACHEREPORT message type to be used for cache reports sent
via Netlink, effectively allowing splitting cache report reception from
mroute programming.

Suggested-by: Ryan Halbrook <halbrook@arista.com>
Signed-off-by: Julien Gomes <julien@arista.com>
---
 include/uapi/linux/rtnetlink.h | 3 +++
 security/selinux/nlmsgtab.c    | 3 ++-
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/include/uapi/linux/rtnetlink.h b/include/uapi/linux/rtnetlink.h
index 564790e854f7..cd1afb900929 100644
--- a/include/uapi/linux/rtnetlink.h
+++ b/include/uapi/linux/rtnetlink.h
@@ -146,6 +146,9 @@ enum {
 	RTM_GETSTATS = 94,
 #define RTM_GETSTATS RTM_GETSTATS
 
+	RTM_NEWCACHEREPORT = 96,
+#define RTM_NEWCACHEREPORT RTM_NEWCACHEREPORT
+
 	__RTM_MAX,
 #define RTM_MAX		(((__RTM_MAX + 3) & ~3) - 1)
 };
diff --git a/security/selinux/nlmsgtab.c b/security/selinux/nlmsgtab.c
index 5aeaf30b7a13..7b7433a1a34c 100644
--- a/security/selinux/nlmsgtab.c
+++ b/security/selinux/nlmsgtab.c
@@ -79,6 +79,7 @@ static const struct nlmsg_perm nlmsg_route_perms[] =
 	{ RTM_GETNSID,		NETLINK_ROUTE_SOCKET__NLMSG_READ  },
 	{ RTM_NEWSTATS,		NETLINK_ROUTE_SOCKET__NLMSG_READ },
 	{ RTM_GETSTATS,		NETLINK_ROUTE_SOCKET__NLMSG_READ  },
+	{ RTM_NEWCACHEREPORT,	NETLINK_ROUTE_SOCKET__NLMSG_READ },
 };
 
 static const struct nlmsg_perm nlmsg_tcpdiag_perms[] =
@@ -158,7 +159,7 @@ int selinux_nlmsg_lookup(u16 sclass, u16 nlmsg_type, u32 *perm)
 	switch (sclass) {
 	case SECCLASS_NETLINK_ROUTE_SOCKET:
 		/* RTM_MAX always point to RTM_SETxxxx, ie RTM_NEWxxx + 3 */
-		BUILD_BUG_ON(RTM_MAX != (RTM_NEWSTATS + 3));
+		BUILD_BUG_ON(RTM_MAX != (RTM_NEWCACHEREPORT + 3));
 		err = nlmsg_perm(nlmsg_type, perm, nlmsg_route_perms,
 				 sizeof(nlmsg_route_perms));
 		break;
-- 
2.13.1

[PATCH net-next 2/3] ipmr: add netlink notifications on igmpmsg cache reports

[Julien Gomes]

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.

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>
---
 include/uapi/linux/mroute.h | 11 ++++++++
 net/ipv4/ipmr.c             | 63 +++++++++++++++++++++++++++++++++++++++++++--
 2 files changed, 72 insertions(+), 2 deletions(-)

diff --git a/include/uapi/linux/mroute.h b/include/uapi/linux/mroute.h
index f904367c0cee..f6f9e01ee734 100644
--- a/include/uapi/linux/mroute.h
+++ b/include/uapi/linux/mroute.h
@@ -152,6 +152,17 @@ enum {
 };
 #define IPMRA_VIFA_MAX (__IPMRA_VIFA_MAX - 1)
 
+/* ipmr netlink cache report attributes */
+enum {
+	IPMRA_CACHEREPORTA_MSGTYPE,
+	IPMRA_CACHEREPORTA_VIF_ID,
+	IPMRA_CACHEREPORTA_SRC_ADDR,
+	IPMRA_CACHEREPORTA_DST_ADDR,
+	IPMRA_CACHEREPORTA_PKT,
+	__IPMRA_CACHEREPORTA_MAX
+};
+#define IPMRA_CACHEREPORTA_MAX (__IPMRA_CACHEREPORTA_MAX - 1)
+
 /* That's all usermode folks */
 
 #define MFC_ASSERT_THRESH (3*HZ)		/* Maximal freq. of asserts */
diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c
index 9374b99c7c17..6d1f4fae3749 100644
--- a/net/ipv4/ipmr.c
+++ b/net/ipv4/ipmr.c
@@ -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);
 
@@ -993,8 +994,7 @@ 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.
  */
@@ -1060,6 +1060,8 @@ 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 +2343,63 @@ static void mroute_netlink_event(struct mr_table *mrt, struct mfc_cache *mfc,
 		rtnl_set_sk_err(net, RTNLGRP_IPV4_MROUTE, err);
 }
 
+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;
+	int payloadlen;
+	int msgsize;
+
+	payloadlen = pkt->len - sizeof(struct igmpmsg);
+	msg = (struct igmpmsg *)skb_network_header(pkt);
+	msgsize = NLMSG_ALIGN(sizeof(struct rtgenmsg))
+			+ nla_total_size(1)
+					/* IPMRA_CACHEREPORTA_MSGTYPE */
+			+ nla_total_size(1)
+					/* IPMRA_CACHEREPORTA_VIF_ID */
+			+ nla_total_size(4)
+					/* IPMRA_CACHEREPORTA_SRC_ADDR */
+			+ nla_total_size(4)
+					/* IPMRA_CACHEREPORTA_DST_ADDR */
+			+ nla_total_size(payloadlen)
+					/* IPMRA_CACHEREPORTA_PKT */
+			;
+
+	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_IPMR;
+	if (nla_put_u8(skb, IPMRA_CACHEREPORTA_MSGTYPE, msg->im_msgtype) ||
+	    nla_put_u8(skb, IPMRA_CACHEREPORTA_VIF_ID, msg->im_vif) ||
+	    nla_put_in_addr(skb, IPMRA_CACHEREPORTA_SRC_ADDR,
+			    msg->im_src.s_addr) ||
+	    nla_put_in_addr(skb, IPMRA_CACHEREPORTA_DST_ADDR,
+			    msg->im_dst.s_addr) ||
+	    nla_put(skb, IPMRA_CACHEREPORTA_PKT, payloadlen,
+		    pkt->data + sizeof(struct igmpmsg)))
+		goto nla_put_failure;
+
+	nlmsg_end(skb, nlh);
+
+	rtnl_notify(skb, net, 0, RTNLGRP_IPV4_MROUTE, NULL, GFP_ATOMIC);
+	return;
+
+nla_put_failure:
+	nlmsg_cancel(skb, nlh);
+errout:
+	kfree_skb(skb);
+	rtnl_set_sk_err(net, RTNLGRP_IPV4_MROUTE, -ENOBUFS);
+}
+
 static int ipmr_rtm_dumproute(struct sk_buff *skb, struct netlink_callback *cb)
 {
 	struct net *net = sock_net(skb->sk);
-- 
2.13.1

[PATCH net-next 3/3] ip6mr: add netlink notifications on mrt6msg cache reports

[Julien Gomes]

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.

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 <halbrook@arista.com>
Signed-off-by: Julien Gomes <julien@arista.com>
---
 include/uapi/linux/mroute6.h | 11 ++++++++
 net/ipv6/ip6mr.c             | 63 ++++++++++++++++++++++++++++++++++++++++++--
 2 files changed, 72 insertions(+), 2 deletions(-)

diff --git a/include/uapi/linux/mroute6.h b/include/uapi/linux/mroute6.h
index ed5721148768..8e3c2d2c170e 100644
--- a/include/uapi/linux/mroute6.h
+++ b/include/uapi/linux/mroute6.h
@@ -133,4 +133,15 @@ struct mrt6msg {
 	struct in6_addr	im6_src, im6_dst;
 };
 
+/* ip6mr netlink cache report attributes */
+enum {
+	IP6MRA_CACHEREPORTA_MSGTYPE,
+	IP6MRA_CACHEREPORTA_MIF_ID,
+	IP6MRA_CACHEREPORTA_SRC_ADDR,
+	IP6MRA_CACHEREPORTA_DST_ADDR,
+	IP6MRA_CACHEREPORTA_PKT,
+	__IP6MRA_CACHEREPORTA_MAX
+};
+#define IP6MRA_CACHEREPORTA_MAX (__IP6MRA_CACHEREPORTA_MAX - 1)
+
 #endif /* _UAPI__LINUX_MROUTE6_H */
diff --git a/net/ipv6/ip6mr.c b/net/ipv6/ip6mr.c
index 374997d26488..8667256b4343 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);
@@ -1123,8 +1124,7 @@ 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.
  */
@@ -1206,6 +1206,8 @@ 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
 	 */
@@ -2455,6 +2457,63 @@ 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;
+	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_CACHEREPORTA_MSGTYPE */
+			+ nla_total_size(2)
+					/* IP6MRA_CACHEREPORTA_MIF_ID */
+			+ nla_total_size(sizeof(struct in6_addr))
+					/* IP6MRA_CACHEREPORTA_SRC_ADDR */
+			+ nla_total_size(sizeof(struct in6_addr))
+					/* IP6MRA_CACHEREPORTA_DST_ADDR */
+			+ nla_total_size(payloadlen)
+					/* IP6MRA_CACHEREPORTA_PKT */
+			;
+
+	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_CACHEREPORTA_MSGTYPE, msg->im6_msgtype) ||
+	    nla_put_u16(skb, IP6MRA_CACHEREPORTA_MIF_ID, msg->im6_mif) ||
+	    nla_put_in6_addr(skb, IP6MRA_CACHEREPORTA_SRC_ADDR,
+			     &msg->im6_src) ||
+	    nla_put_in6_addr(skb, IP6MRA_CACHEREPORTA_DST_ADDR,
+			     &msg->im6_dst) ||
+	    nla_put(skb, IP6MRA_CACHEREPORTA_PKT, payloadlen,
+		    pkt->data + sizeof(struct mrt6msg)))
+		goto nla_put_failure;
+
+	nlmsg_end(skb, nlh);
+
+	rtnl_notify(skb, net, 0, RTNLGRP_IPV6_MROUTE, NULL, GFP_ATOMIC);
+	return;
+
+nla_put_failure:
+	nlmsg_cancel(skb, nlh);
+errout:
+	kfree_skb(skb);
+	rtnl_set_sk_err(net, RTNLGRP_IPV6_MROUTE, -ENOBUFS);
+}
+
 static int ip6mr_rtm_dumproute(struct sk_buff *skb, struct netlink_callback *cb)
 {
 	struct net *net = sock_net(skb->sk);
-- 
2.13.1

Re: [PATCH net-next 2/3] ipmr: add netlink notifications on igmpmsg cache reports

[Nicolas Dichtel]

Le 13/06/2017 à 19:08, Julien Gomes a écrit :
> 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.
> 
> 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>
> ---
>  include/uapi/linux/mroute.h | 11 ++++++++
>  net/ipv4/ipmr.c             | 63 +++++++++++++++++++++++++++++++++++++++++++--
>  2 files changed, 72 insertions(+), 2 deletions(-)
> 
> diff --git a/include/uapi/linux/mroute.h b/include/uapi/linux/mroute.h
> index f904367c0cee..f6f9e01ee734 100644
> --- a/include/uapi/linux/mroute.h
> +++ b/include/uapi/linux/mroute.h
> @@ -152,6 +152,17 @@ enum {
>  };
>  #define IPMRA_VIFA_MAX (__IPMRA_VIFA_MAX - 1)
>  
> +/* ipmr netlink cache report attributes */
> +enum {
IPMRA_CACHEREPORTA_UNSPEC is missing.
By the way, maybe something shorter than IPMRA_CACHEREPORTA_ would be better.
What about IPMR_CREPORTA_? IPMR_CACHEA_? IPMR_IGMPA_? or whatever.
What is the signification of the two 'A'? One for 'attribute', but the other?

> +	IPMRA_CACHEREPORTA_MSGTYPE,
> +	IPMRA_CACHEREPORTA_VIF_ID,
> +	IPMRA_CACHEREPORTA_SRC_ADDR,
> +	IPMRA_CACHEREPORTA_DST_ADDR,
> +	IPMRA_CACHEREPORTA_PKT,
> +	__IPMRA_CACHEREPORTA_MAX
> +};
> +#define IPMRA_CACHEREPORTA_MAX (__IPMRA_CACHEREPORTA_MAX - 1)

Re: [PATCH net-next 2/3] ipmr: add netlink notifications on igmpmsg cache reports

[Julien Gomes]

On 06/14/2017 12:56 AM, Nicolas Dichtel wrote:
> Le 13/06/2017 à 19:08, Julien Gomes a écrit :
>> 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.
>>
>> 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>
>> ---
>>  include/uapi/linux/mroute.h | 11 ++++++++
>>  net/ipv4/ipmr.c             | 63 +++++++++++++++++++++++++++++++++++++++++++--
>>  2 files changed, 72 insertions(+), 2 deletions(-)
>>
>> diff --git a/include/uapi/linux/mroute.h b/include/uapi/linux/mroute.h
>> index f904367c0cee..f6f9e01ee734 100644
>> --- a/include/uapi/linux/mroute.h
>> +++ b/include/uapi/linux/mroute.h
>> @@ -152,6 +152,17 @@ enum {
>>  };
>>  #define IPMRA_VIFA_MAX (__IPMRA_VIFA_MAX - 1)
>>  
>> +/* ipmr netlink cache report attributes */
>> +enum {
> IPMRA_CACHEREPORTA_UNSPEC is missing.

Indeed, I will add it.

> By the way, maybe something shorter than IPMRA_CACHEREPORTA_ would be better.
> What about IPMR_CREPORTA_? IPMR_CACHEA_? IPMR_IGMPA_? or whatever.

I see absolutely no issue in shortening them.
IPMRA_CREPORT_ sounds good to me.

> What is the signification of the two 'A'? One for 'attribute', but the other?

Now that you mention it, the second 'A' is simply redundant.
I will remove it and go with IPMRA_CREPORT_.

-- 
Julien Gomes