Commit 660a38bf authored by Jakub Kicinski's avatar Jakub Kicinski
Browse files

Merge branch 'support-for-the-ioam-insertion-frequency' 

Justin Iurman says:

====================
Support for the IOAM insertion frequency

The insertion frequency is represented as "k/n", meaning IOAM will be
added to {k} packets over {n} packets, with 0 < k <= n and 1 <= {k,n} <=
1000000. Therefore, it provides the following percentages of insertion
frequency: [0.0001% (min) ... 100% (max)].

Not only this solution allows an operator to apply dynamic frequencies
based on the current traffic load, but it also provides some
flexibility, i.e., by distinguishing similar cases (e.g., "1/2" and
"2/4").

"1/2" = Y N Y N Y N Y N ...
"2/4" = Y Y N N Y Y N N ...
====================

Link: https://lore.kernel.org/r/20220202142554.9691-1-justin.iurman@uliege.be


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parents c78b8b20 08731d30

include/uapi/linux/ioam6_iptunnel.h

+9 −0
Original line number Diff line number Diff line
@@ -41,6 +41,15 @@ enum { 
	/* IOAM Trace Header */

	IOAM6_IPTUNNEL_TRACE,		/* struct ioam6_trace_hdr */



	/* Insertion frequency:

	 * "k over n" packets (0 < k <= n)

	 * [0.0001% ... 100%]

	 */

#define IOAM6_IPTUNNEL_FREQ_MIN 1

#define IOAM6_IPTUNNEL_FREQ_MAX 1000000

	IOAM6_IPTUNNEL_FREQ_K,		/* u32 */

	IOAM6_IPTUNNEL_FREQ_N,		/* u32 */



	__IOAM6_IPTUNNEL_MAX,

};

net/ipv6/ioam6_iptunnel.c

+57 −2
Original line number Diff line number Diff line
@@ -32,13 +32,25 @@ struct ioam6_lwt_encap { 
	struct ioam6_trace_hdr traceh;

} __packed;



struct ioam6_lwt_freq {

	u32 k;

	u32 n;

};



struct ioam6_lwt {

	struct dst_cache cache;

	struct ioam6_lwt_freq freq;

	atomic_t pkt_cnt;

	u8 mode;

	struct in6_addr tundst;

	struct ioam6_lwt_encap	tuninfo;

};



static struct netlink_range_validation freq_range = {

	.min = IOAM6_IPTUNNEL_FREQ_MIN,

	.max = IOAM6_IPTUNNEL_FREQ_MAX,

};



static struct ioam6_lwt *ioam6_lwt_state(struct lwtunnel_state *lwt)

{

	return (struct ioam6_lwt *)lwt->data;
@@ -55,6 +67,8 @@ static struct ioam6_trace_hdr *ioam6_lwt_trace(struct lwtunnel_state *lwt) 
}



static const struct nla_policy ioam6_iptunnel_policy[IOAM6_IPTUNNEL_MAX + 1] = {

	[IOAM6_IPTUNNEL_FREQ_K] = NLA_POLICY_FULL_RANGE(NLA_U32, &freq_range),

	[IOAM6_IPTUNNEL_FREQ_N] = NLA_POLICY_FULL_RANGE(NLA_U32, &freq_range),

	[IOAM6_IPTUNNEL_MODE]	= NLA_POLICY_RANGE(NLA_U8,

						   IOAM6_IPTUNNEL_MODE_MIN,

						   IOAM6_IPTUNNEL_MODE_MAX),
@@ -96,6 +110,7 @@ static int ioam6_build_state(struct net *net, struct nlattr *nla, 
	struct lwtunnel_state *lwt;

	struct ioam6_lwt *ilwt;

	int len_aligned, err;

	u32 freq_k, freq_n;

	u8 mode;



	if (family != AF_INET6)
@@ -106,6 +121,23 @@ static int ioam6_build_state(struct net *net, struct nlattr *nla, 
	if (err < 0)

		return err;



	if ((!tb[IOAM6_IPTUNNEL_FREQ_K] && tb[IOAM6_IPTUNNEL_FREQ_N]) ||

	    (tb[IOAM6_IPTUNNEL_FREQ_K] && !tb[IOAM6_IPTUNNEL_FREQ_N])) {

		NL_SET_ERR_MSG(extack, "freq: missing parameter");

		return -EINVAL;

	} else if (!tb[IOAM6_IPTUNNEL_FREQ_K] && !tb[IOAM6_IPTUNNEL_FREQ_N]) {

		freq_k = IOAM6_IPTUNNEL_FREQ_MIN;

		freq_n = IOAM6_IPTUNNEL_FREQ_MIN;

	} else {

		freq_k = nla_get_u32(tb[IOAM6_IPTUNNEL_FREQ_K]);

		freq_n = nla_get_u32(tb[IOAM6_IPTUNNEL_FREQ_N]);



		if (freq_k > freq_n) {

			NL_SET_ERR_MSG(extack, "freq: k > n is forbidden");

			return -EINVAL;

		}

	}



	if (!tb[IOAM6_IPTUNNEL_MODE])

		mode = IOAM6_IPTUNNEL_MODE_INLINE;

	else
@@ -140,6 +172,10 @@ static int ioam6_build_state(struct net *net, struct nlattr *nla, 
		return err;

	}



	atomic_set(&ilwt->pkt_cnt, 0);

	ilwt->freq.k = freq_k;

	ilwt->freq.n = freq_n;



	ilwt->mode = mode;

	if (tb[IOAM6_IPTUNNEL_DST])

		ilwt->tundst = nla_get_in6_addr(tb[IOAM6_IPTUNNEL_DST]);
@@ -263,11 +299,18 @@ static int ioam6_output(struct net *net, struct sock *sk, struct sk_buff *skb) 
	struct in6_addr orig_daddr;

	struct ioam6_lwt *ilwt;

	int err = -EINVAL;

	u32 pkt_cnt;



	if (skb->protocol != htons(ETH_P_IPV6))

		goto drop;



	ilwt = ioam6_lwt_state(dst->lwtstate);



	/* Check for insertion frequency (i.e., "k over n" insertions) */

	pkt_cnt = atomic_fetch_inc(&ilwt->pkt_cnt);

	if (pkt_cnt % ilwt->freq.n >= ilwt->freq.k)

		goto out;



	orig_daddr = ipv6_hdr(skb)->daddr;



	switch (ilwt->mode) {
@@ -358,6 +401,14 @@ static int ioam6_fill_encap_info(struct sk_buff *skb, 
	struct ioam6_lwt *ilwt = ioam6_lwt_state(lwtstate);

	int err;



	err = nla_put_u32(skb, IOAM6_IPTUNNEL_FREQ_K, ilwt->freq.k);

	if (err)

		goto ret;



	err = nla_put_u32(skb, IOAM6_IPTUNNEL_FREQ_N, ilwt->freq.n);

	if (err)

		goto ret;



	err = nla_put_u8(skb, IOAM6_IPTUNNEL_MODE, ilwt->mode);

	if (err)

		goto ret;
@@ -379,7 +430,9 @@ static int ioam6_encap_nlsize(struct lwtunnel_state *lwtstate) 
	struct ioam6_lwt *ilwt = ioam6_lwt_state(lwtstate);

	int nlsize;



	nlsize = nla_total_size(sizeof(ilwt->mode)) +

	nlsize = nla_total_size(sizeof(ilwt->freq.k)) +

		  nla_total_size(sizeof(ilwt->freq.n)) +

		  nla_total_size(sizeof(ilwt->mode)) +

		  nla_total_size(sizeof(ilwt->tuninfo.traceh));



	if (ilwt->mode != IOAM6_IPTUNNEL_MODE_INLINE)
@@ -395,7 +448,9 @@ static int ioam6_encap_cmp(struct lwtunnel_state *a, struct lwtunnel_state *b) 
	struct ioam6_lwt *ilwt_a = ioam6_lwt_state(a);

	struct ioam6_lwt *ilwt_b = ioam6_lwt_state(b);



	return (ilwt_a->mode != ilwt_b->mode ||

	return (ilwt_a->freq.k != ilwt_b->freq.k ||

		ilwt_a->freq.n != ilwt_b->freq.n ||

		ilwt_a->mode != ilwt_b->mode ||

		(ilwt_a->mode != IOAM6_IPTUNNEL_MODE_INLINE &&

		 !ipv6_addr_equal(&ilwt_a->tundst, &ilwt_b->tundst)) ||

		trace_a->namespace_id != trace_b->namespace_id);