ipv6: ioam: Insertion frequency in lwtunnel output

Add support for the IOAM insertion frequency inside its lwtunnel output
function. This patch introduces a new (atomic) counter for packets,
based on which the algorithm will decide if IOAM should be added or not.

Default frequency is "1/1" (i.e., applied to all packets) for backward
compatibility. The iproute2 patch is ready and will be submitted as soon
as this one is accepted.

Previous iproute2 command:
ip -6 ro ad fc00::1/128 encap ioam6 [ mode ... ] ...

New iproute2 command:
ip -6 ro ad fc00::1/128 encap ioam6 [ freq k/n ] [ mode ... ] ...

Signed-off-by: Justin Iurman <justin.iurman@uliege.be>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Justin Iurman 2022-02-02 15:25:54 +01:00 committed by Jakub Kicinski
parent be847673cf
commit 08731d30e7
1 changed files with 57 additions and 2 deletions

View File

@ -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);