Commit 795709af authored by David S. Miller's avatar David S. Miller
Browse files

Merge branch 'tcp_metrics_saddr' 



Christoph Paasch says:

====================
Make tcp-metrics source-address aware

Currently tcp-metrics only stores per-destination addresses. This brings
problems, when a host has multiple interfaces (e.g., a smartphone having
WiFi/3G):

For example, a host contacting a server over WiFi will store the tcp-metrics
per destination IP. If then the host contacts the same server over 3G, the
same tcp-metrics will be used, although the path-characteristics are completly
different (e.g., the ssthresh is probably not the same).

In case of TFO this is not a problem, as the server will provide us a new cookie
once he saw our SYN+DATA with an incorrect cookie.
It may be (in case of carrier-grade NAT), that we keep the same public IP but
have a different private IP. Thus, we better reuse the old cookie even if our
source-IP has changed. However, this scenario is probably very uncommon, as
carriers try to provide the same src-IP to the clients behind their CGN.

Patches 1 + 2 add the source-IP to the tcp metrics.

Patches 3 to 5 modify the netlink-api to support the source-IP. From now on,
when using the command "ip tcp_metrics delete address ADDRESS" all entries
which match this destination IP will be deleted.

Today's iproute2 will complain when doing "ip tcp_metrics flush PREFIX" if
several entries are present for the same destination-IP but with different
source-IPs:

root@client:~/test# ip tcp_metrics
10.2.1.2 age 3.640sec rtt 16250us rttvar 15000us cwnd 10
10.2.1.2 age 4.030sec rtt 18750us rttvar 15000us cwnd 10
root@client:~/test# ip tcp_metrics flush 10.2.1.2/16
Failed to send flush request
: No such process

Follow-up patches will modify iproute2 to handle this correctly and allow
specifying the source-IP in the get/del commands.

v2: Added the patch that allows to selectively get/del of tcp-metrics based
    on src-IP and moved the patch that adds the new netlink attribute before
    the other patches.
====================

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parents 1a6c1e5b 3e7013dd

include/uapi/linux/tcp_metrics.h

+2 −0
Original line number Diff line number Diff line
@@ -35,6 +35,8 @@ enum { 
	TCP_METRICS_ATTR_FOPEN_SYN_DROPS,	/* u16, count of drops */

	TCP_METRICS_ATTR_FOPEN_SYN_DROP_TS,	/* msecs age */

	TCP_METRICS_ATTR_FOPEN_COOKIE,		/* binary */

	TCP_METRICS_ATTR_SADDR_IPV4,		/* u32 */

	TCP_METRICS_ATTR_SADDR_IPV6,		/* binary */



	__TCP_METRICS_ATTR_MAX,

};

net/ipv4/tcp_metrics.c

+103 −48
Original line number Diff line number Diff line
@@ -31,7 +31,8 @@ struct tcp_fastopen_metrics { 


struct tcp_metrics_block {

	struct tcp_metrics_block __rcu	*tcpm_next;

	struct inetpeer_addr		tcpm_addr;

	struct inetpeer_addr		tcpm_saddr;

	struct inetpeer_addr		tcpm_daddr;

	unsigned long			tcpm_stamp;

	u32				tcpm_ts;

	u32				tcpm_ts_stamp;
@@ -131,7 +132,8 @@ static void tcpm_suck_dst(struct tcp_metrics_block *tm, struct dst_entry *dst, 
}



static struct tcp_metrics_block *tcpm_new(struct dst_entry *dst,

					  struct inetpeer_addr *addr,

					  struct inetpeer_addr *saddr,

					  struct inetpeer_addr *daddr,

					  unsigned int hash,

					  bool reclaim)

{
@@ -155,7 +157,8 @@ static struct tcp_metrics_block *tcpm_new(struct dst_entry *dst, 
		if (!tm)

			goto out_unlock;

	}

	tm->tcpm_addr = *addr;

	tm->tcpm_saddr = *saddr;

	tm->tcpm_daddr = *daddr;



	tcpm_suck_dst(tm, dst, true);
@@ -189,7 +192,8 @@ static struct tcp_metrics_block *tcp_get_encode(struct tcp_metrics_block *tm, in 
	return NULL;

}



static struct tcp_metrics_block *__tcp_get_metrics(const struct inetpeer_addr *addr,

static struct tcp_metrics_block *__tcp_get_metrics(const struct inetpeer_addr *saddr,

						   const struct inetpeer_addr *daddr,

						   struct net *net, unsigned int hash)

{

	struct tcp_metrics_block *tm;
@@ -197,7 +201,8 @@ static struct tcp_metrics_block *__tcp_get_metrics(const struct inetpeer_addr *a 


	for (tm = rcu_dereference(net->ipv4.tcp_metrics_hash[hash].chain); tm;

	     tm = rcu_dereference(tm->tcpm_next)) {

		if (addr_same(&tm->tcpm_addr, addr))

		if (addr_same(&tm->tcpm_saddr, saddr) &&

		    addr_same(&tm->tcpm_daddr, daddr))

			break;

		depth++;

	}
@@ -208,19 +213,22 @@ static struct tcp_metrics_block *__tcp_get_metrics_req(struct request_sock *req, 
						       struct dst_entry *dst)

{

	struct tcp_metrics_block *tm;

	struct inetpeer_addr addr;

	struct inetpeer_addr saddr, daddr;

	unsigned int hash;

	struct net *net;



	addr.family = req->rsk_ops->family;

	switch (addr.family) {

	saddr.family = req->rsk_ops->family;

	daddr.family = req->rsk_ops->family;

	switch (daddr.family) {

	case AF_INET:

		addr.addr.a4 = inet_rsk(req)->ir_rmt_addr;

		hash = (__force unsigned int) addr.addr.a4;

		saddr.addr.a4 = inet_rsk(req)->ir_loc_addr;

		daddr.addr.a4 = inet_rsk(req)->ir_rmt_addr;

		hash = (__force unsigned int) daddr.addr.a4;

		break;

#if IS_ENABLED(CONFIG_IPV6)

	case AF_INET6:

		*(struct in6_addr *)addr.addr.a6 = inet_rsk(req)->ir_v6_rmt_addr;

		*(struct in6_addr *)saddr.addr.a6 = inet_rsk(req)->ir_v6_loc_addr;

		*(struct in6_addr *)daddr.addr.a6 = inet_rsk(req)->ir_v6_rmt_addr;

		hash = ipv6_addr_hash(&inet_rsk(req)->ir_v6_rmt_addr);

		break;

#endif
@@ -233,7 +241,8 @@ static struct tcp_metrics_block *__tcp_get_metrics_req(struct request_sock *req, 


	for (tm = rcu_dereference(net->ipv4.tcp_metrics_hash[hash].chain); tm;

	     tm = rcu_dereference(tm->tcpm_next)) {

		if (addr_same(&tm->tcpm_addr, &addr))

		if (addr_same(&tm->tcpm_saddr, &saddr) &&

		    addr_same(&tm->tcpm_daddr, &daddr))

			break;

	}

	tcpm_check_stamp(tm, dst);
@@ -243,19 +252,22 @@ static struct tcp_metrics_block *__tcp_get_metrics_req(struct request_sock *req, 
static struct tcp_metrics_block *__tcp_get_metrics_tw(struct inet_timewait_sock *tw)

{

	struct tcp_metrics_block *tm;

	struct inetpeer_addr addr;

	struct inetpeer_addr saddr, daddr;

	unsigned int hash;

	struct net *net;



	addr.family = tw->tw_family;

	switch (addr.family) {

	saddr.family = tw->tw_family;

	daddr.family = tw->tw_family;

	switch (daddr.family) {

	case AF_INET:

		addr.addr.a4 = tw->tw_daddr;

		hash = (__force unsigned int) addr.addr.a4;

		saddr.addr.a4 = tw->tw_rcv_saddr;

		daddr.addr.a4 = tw->tw_daddr;

		hash = (__force unsigned int) daddr.addr.a4;

		break;

#if IS_ENABLED(CONFIG_IPV6)

	case AF_INET6:

		*(struct in6_addr *)addr.addr.a6 = tw->tw_v6_daddr;

		*(struct in6_addr *)saddr.addr.a6 = tw->tw_v6_rcv_saddr;

		*(struct in6_addr *)daddr.addr.a6 = tw->tw_v6_daddr;

		hash = ipv6_addr_hash(&tw->tw_v6_daddr);

		break;

#endif
@@ -268,7 +280,8 @@ static struct tcp_metrics_block *__tcp_get_metrics_tw(struct inet_timewait_sock 


	for (tm = rcu_dereference(net->ipv4.tcp_metrics_hash[hash].chain); tm;

	     tm = rcu_dereference(tm->tcpm_next)) {

		if (addr_same(&tm->tcpm_addr, &addr))

		if (addr_same(&tm->tcpm_saddr, &saddr) &&

		    addr_same(&tm->tcpm_daddr, &daddr))

			break;

	}

	return tm;
@@ -279,20 +292,23 @@ static struct tcp_metrics_block *tcp_get_metrics(struct sock *sk, 
						 bool create)

{

	struct tcp_metrics_block *tm;

	struct inetpeer_addr addr;

	struct inetpeer_addr saddr, daddr;

	unsigned int hash;

	struct net *net;

	bool reclaim;



	addr.family = sk->sk_family;

	switch (addr.family) {

	saddr.family = sk->sk_family;

	daddr.family = sk->sk_family;

	switch (daddr.family) {

	case AF_INET:

		addr.addr.a4 = inet_sk(sk)->inet_daddr;

		hash = (__force unsigned int) addr.addr.a4;

		saddr.addr.a4 = inet_sk(sk)->inet_saddr;

		daddr.addr.a4 = inet_sk(sk)->inet_daddr;

		hash = (__force unsigned int) daddr.addr.a4;

		break;

#if IS_ENABLED(CONFIG_IPV6)

	case AF_INET6:

		*(struct in6_addr *)addr.addr.a6 = sk->sk_v6_daddr;

		*(struct in6_addr *)saddr.addr.a6 = sk->sk_v6_rcv_saddr;

		*(struct in6_addr *)daddr.addr.a6 = sk->sk_v6_daddr;

		hash = ipv6_addr_hash(&sk->sk_v6_daddr);

		break;

#endif
@@ -303,14 +319,14 @@ static struct tcp_metrics_block *tcp_get_metrics(struct sock *sk, 
	net = dev_net(dst->dev);

	hash = hash_32(hash, net->ipv4.tcp_metrics_hash_log);



	tm = __tcp_get_metrics(&addr, net, hash);

	tm = __tcp_get_metrics(&saddr, &daddr, net, hash);

	reclaim = false;

	if (tm == TCP_METRICS_RECLAIM_PTR) {

		reclaim = true;

		tm = NULL;

	}

	if (!tm && create)

		tm = tcpm_new(dst, &addr, hash, reclaim);

		tm = tcpm_new(dst, &saddr, &daddr, hash, reclaim);

	else

		tcpm_check_stamp(tm, dst);
@@ -724,15 +740,21 @@ static int tcp_metrics_fill_info(struct sk_buff *msg, 
	struct nlattr *nest;

	int i;



	switch (tm->tcpm_addr.family) {

	switch (tm->tcpm_daddr.family) {

	case AF_INET:

		if (nla_put_be32(msg, TCP_METRICS_ATTR_ADDR_IPV4,

				tm->tcpm_addr.addr.a4) < 0)

				tm->tcpm_daddr.addr.a4) < 0)

			goto nla_put_failure;

		if (nla_put_be32(msg, TCP_METRICS_ATTR_SADDR_IPV4,

				tm->tcpm_saddr.addr.a4) < 0)

			goto nla_put_failure;

		break;

	case AF_INET6:

		if (nla_put(msg, TCP_METRICS_ATTR_ADDR_IPV6, 16,

			    tm->tcpm_addr.addr.a6) < 0)

			    tm->tcpm_daddr.addr.a6) < 0)

			goto nla_put_failure;

		if (nla_put(msg, TCP_METRICS_ATTR_SADDR_IPV6, 16,

			    tm->tcpm_saddr.addr.a6) < 0)

			goto nla_put_failure;

		break;

	default:
@@ -855,44 +877,66 @@ done: 
	return skb->len;

}



static int parse_nl_addr(struct genl_info *info, struct inetpeer_addr *addr,

			 unsigned int *hash, int optional)

static int __parse_nl_addr(struct genl_info *info, struct inetpeer_addr *addr,

			   unsigned int *hash, int optional, int v4, int v6)

{

	struct nlattr *a;



	a = info->attrs[TCP_METRICS_ATTR_ADDR_IPV4];

	a = info->attrs[v4];

	if (a) {

		addr->family = AF_INET;

		addr->addr.a4 = nla_get_be32(a);

		if (hash)

			*hash = (__force unsigned int) addr->addr.a4;

		return 0;

	}

	a = info->attrs[TCP_METRICS_ATTR_ADDR_IPV6];

	a = info->attrs[v6];

	if (a) {

		if (nla_len(a) != sizeof(struct in6_addr))

			return -EINVAL;

		addr->family = AF_INET6;

		memcpy(addr->addr.a6, nla_data(a), sizeof(addr->addr.a6));

		if (hash)

			*hash = ipv6_addr_hash((struct in6_addr *) addr->addr.a6);

		return 0;

	}

	return optional ? 1 : -EAFNOSUPPORT;

}



static int parse_nl_addr(struct genl_info *info, struct inetpeer_addr *addr,

			 unsigned int *hash, int optional)

{

	return __parse_nl_addr(info, addr, hash, optional,

			       TCP_METRICS_ATTR_ADDR_IPV4,

			       TCP_METRICS_ATTR_ADDR_IPV6);

}



static int parse_nl_saddr(struct genl_info *info, struct inetpeer_addr *addr)

{

	return __parse_nl_addr(info, addr, NULL, 0,

			       TCP_METRICS_ATTR_SADDR_IPV4,

			       TCP_METRICS_ATTR_SADDR_IPV6);

}



static int tcp_metrics_nl_cmd_get(struct sk_buff *skb, struct genl_info *info)

{

	struct tcp_metrics_block *tm;

	struct inetpeer_addr addr;

	struct inetpeer_addr saddr, daddr;

	unsigned int hash;

	struct sk_buff *msg;

	struct net *net = genl_info_net(info);

	void *reply;

	int ret;

	bool src = true;



	ret = parse_nl_addr(info, &addr, &hash, 0);

	ret = parse_nl_addr(info, &daddr, &hash, 0);

	if (ret < 0)

		return ret;



	ret = parse_nl_saddr(info, &saddr);

	if (ret < 0)

		src = false;



	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);

	if (!msg)

		return -ENOMEM;
@@ -907,7 +951,8 @@ static int tcp_metrics_nl_cmd_get(struct sk_buff *skb, struct genl_info *info) 
	rcu_read_lock();

	for (tm = rcu_dereference(net->ipv4.tcp_metrics_hash[hash].chain); tm;

	     tm = rcu_dereference(tm->tcpm_next)) {

		if (addr_same(&tm->tcpm_addr, &addr)) {

		if (addr_same(&tm->tcpm_daddr, &daddr) &&

		    (!src || addr_same(&tm->tcpm_saddr, &saddr))) {

			ret = tcp_metrics_fill_info(msg, tm);

			break;

		}
@@ -960,34 +1005,44 @@ static int tcp_metrics_flush_all(struct net *net) 
static int tcp_metrics_nl_cmd_del(struct sk_buff *skb, struct genl_info *info)

{

	struct tcpm_hash_bucket *hb;

	struct tcp_metrics_block *tm;

	struct tcp_metrics_block *tm, *tmlist = NULL;

	struct tcp_metrics_block __rcu **pp;

	struct inetpeer_addr addr;

	struct inetpeer_addr saddr, daddr;

	unsigned int hash;

	struct net *net = genl_info_net(info);

	int ret;

	bool src = true;



	ret = parse_nl_addr(info, &addr, &hash, 1);

	ret = parse_nl_addr(info, &daddr, &hash, 1);

	if (ret < 0)

		return ret;

	if (ret > 0)

		return tcp_metrics_flush_all(net);

	ret = parse_nl_saddr(info, &saddr);

	if (ret < 0)

		src = false;



	hash = hash_32(hash, net->ipv4.tcp_metrics_hash_log);

	hb = net->ipv4.tcp_metrics_hash + hash;

	pp = &hb->chain;

	spin_lock_bh(&tcp_metrics_lock);

	for (tm = deref_locked_genl(*pp); tm;

	     pp = &tm->tcpm_next, tm = deref_locked_genl(*pp)) {

		if (addr_same(&tm->tcpm_addr, &addr)) {

	for (tm = deref_locked_genl(*pp); tm; tm = deref_locked_genl(*pp)) {

		if (addr_same(&tm->tcpm_daddr, &daddr) &&

		    (!src || addr_same(&tm->tcpm_saddr, &saddr))) {

			*pp = tm->tcpm_next;

			break;

			tm->tcpm_next = tmlist;

			tmlist = tm;

		} else {

			pp = &tm->tcpm_next;

		}

	}

	spin_unlock_bh(&tcp_metrics_lock);

	if (!tm)

	if (!tmlist)

		return -ESRCH;

	for (tm = tmlist; tm; tm = tmlist) {

		tmlist = tm->tcpm_next;

		kfree_rcu(tm, rcu_head);

	}

	return 0;

}

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