ipv6: ioam: Add support for the ip6ip6 encapsulation

This patch adds support for the ip6ip6 encapsulation by providing three encap
modes: inline, encap and auto.

Signed-off-by: Justin Iurman <justin.iurman@uliege.be>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Justin Iurman 2021-10-03 20:45:38 +02:00 committed by David S. Miller
parent 7b34e449e0
commit 8cb3bf8bff
3 changed files with 241 additions and 53 deletions

View File

@ -9,9 +9,38 @@
#ifndef _UAPI_LINUX_IOAM6_IPTUNNEL_H
#define _UAPI_LINUX_IOAM6_IPTUNNEL_H
/* Encap modes:
* - inline: direct insertion
* - encap: ip6ip6 encapsulation
* - auto: inline for local packets, encap for in-transit packets
*/
enum {
__IOAM6_IPTUNNEL_MODE_MIN,
IOAM6_IPTUNNEL_MODE_INLINE,
IOAM6_IPTUNNEL_MODE_ENCAP,
IOAM6_IPTUNNEL_MODE_AUTO,
__IOAM6_IPTUNNEL_MODE_MAX,
};
#define IOAM6_IPTUNNEL_MODE_MIN (__IOAM6_IPTUNNEL_MODE_MIN + 1)
#define IOAM6_IPTUNNEL_MODE_MAX (__IOAM6_IPTUNNEL_MODE_MAX - 1)
enum {
IOAM6_IPTUNNEL_UNSPEC,
/* Encap mode */
IOAM6_IPTUNNEL_MODE, /* u8 */
/* Tunnel dst address.
* For encap,auto modes.
*/
IOAM6_IPTUNNEL_DST, /* struct in6_addr */
/* IOAM Trace Header */
IOAM6_IPTUNNEL_TRACE, /* struct ioam6_trace_hdr */
__IOAM6_IPTUNNEL_MAX,
};

View File

@ -332,10 +332,10 @@ config IPV6_IOAM6_LWTUNNEL
bool "IPv6: IOAM Pre-allocated Trace insertion support"
depends on IPV6
select LWTUNNEL
select DST_CACHE
help
Support for the inline insertion of IOAM Pre-allocated
Trace Header (only on locally generated packets), using
the lightweight tunnels mechanism.
Support for the insertion of IOAM Pre-allocated Trace
Header using the lightweight tunnels mechanism.
If unsure, say N.

View File

@ -17,6 +17,10 @@
#include <net/lwtunnel.h>
#include <net/ioam6.h>
#include <net/netlink.h>
#include <net/ipv6.h>
#include <net/dst_cache.h>
#include <net/ip6_route.h>
#include <net/addrconf.h>
#define IOAM6_MASK_SHORT_FIELDS 0xff100000
#define IOAM6_MASK_WIDE_FIELDS 0xe00000
@ -29,6 +33,9 @@ struct ioam6_lwt_encap {
} __packed;
struct ioam6_lwt {
struct dst_cache cache;
u8 mode;
struct in6_addr tundst;
struct ioam6_lwt_encap tuninfo;
};
@ -48,6 +55,10 @@ 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_MODE] = NLA_POLICY_RANGE(NLA_U8,
IOAM6_IPTUNNEL_MODE_MIN,
IOAM6_IPTUNNEL_MODE_MAX),
[IOAM6_IPTUNNEL_DST] = NLA_POLICY_EXACT_LEN(sizeof(struct in6_addr)),
[IOAM6_IPTUNNEL_TRACE] = NLA_POLICY_EXACT_LEN(sizeof(struct ioam6_trace_hdr)),
};
@ -78,9 +89,10 @@ static int ioam6_build_state(struct net *net, struct nlattr *nla,
struct nlattr *tb[IOAM6_IPTUNNEL_MAX + 1];
struct ioam6_lwt_encap *tuninfo;
struct ioam6_trace_hdr *trace;
struct lwtunnel_state *s;
int len_aligned;
int len, err;
struct lwtunnel_state *lwt;
struct ioam6_lwt *ilwt;
int len_aligned, err;
u8 mode;
if (family != AF_INET6)
return -EINVAL;
@ -90,6 +102,16 @@ static int ioam6_build_state(struct net *net, struct nlattr *nla,
if (err < 0)
return err;
if (!tb[IOAM6_IPTUNNEL_MODE])
mode = IOAM6_IPTUNNEL_MODE_INLINE;
else
mode = nla_get_u8(tb[IOAM6_IPTUNNEL_MODE]);
if (!tb[IOAM6_IPTUNNEL_DST] && mode != IOAM6_IPTUNNEL_MODE_INLINE) {
NL_SET_ERR_MSG(extack, "this mode needs a tunnel destination");
return -EINVAL;
}
if (!tb[IOAM6_IPTUNNEL_TRACE]) {
NL_SET_ERR_MSG(extack, "missing trace");
return -EINVAL;
@ -102,15 +124,24 @@ static int ioam6_build_state(struct net *net, struct nlattr *nla,
return -EINVAL;
}
len = sizeof(*tuninfo) + trace->remlen * 4;
len_aligned = ALIGN(len, 8);
s = lwtunnel_state_alloc(len_aligned);
if (!s)
len_aligned = ALIGN(trace->remlen * 4, 8);
lwt = lwtunnel_state_alloc(sizeof(*ilwt) + len_aligned);
if (!lwt)
return -ENOMEM;
tuninfo = ioam6_lwt_info(s);
tuninfo->eh.hdrlen = (len_aligned >> 3) - 1;
ilwt = ioam6_lwt_state(lwt);
err = dst_cache_init(&ilwt->cache, GFP_ATOMIC);
if (err) {
kfree(lwt);
return err;
}
ilwt->mode = mode;
if (tb[IOAM6_IPTUNNEL_DST])
ilwt->tundst = nla_get_in6_addr(tb[IOAM6_IPTUNNEL_DST]);
tuninfo = ioam6_lwt_info(lwt);
tuninfo->eh.hdrlen = ((sizeof(*tuninfo) + len_aligned) >> 3) - 1;
tuninfo->pad[0] = IPV6_TLV_PADN;
tuninfo->ioamh.type = IOAM6_TYPE_PREALLOC;
tuninfo->ioamh.opt_type = IPV6_TLV_IOAM;
@ -119,27 +150,39 @@ static int ioam6_build_state(struct net *net, struct nlattr *nla,
memcpy(&tuninfo->traceh, trace, sizeof(*trace));
len = len_aligned - len;
if (len == 1) {
tuninfo->traceh.data[trace->remlen * 4] = IPV6_TLV_PAD1;
} else if (len > 0) {
if (len_aligned - trace->remlen * 4) {
tuninfo->traceh.data[trace->remlen * 4] = IPV6_TLV_PADN;
tuninfo->traceh.data[trace->remlen * 4 + 1] = len - 2;
tuninfo->traceh.data[trace->remlen * 4 + 1] = 2;
}
s->type = LWTUNNEL_ENCAP_IOAM6;
s->flags |= LWTUNNEL_STATE_OUTPUT_REDIRECT;
lwt->type = LWTUNNEL_ENCAP_IOAM6;
lwt->flags |= LWTUNNEL_STATE_OUTPUT_REDIRECT;
*ts = s;
*ts = lwt;
return 0;
}
static int ioam6_do_inline(struct sk_buff *skb, struct ioam6_lwt_encap *tuninfo)
static int ioam6_do_fill(struct net *net, struct sk_buff *skb)
{
struct ioam6_trace_hdr *trace;
struct ipv6hdr *oldhdr, *hdr;
struct ioam6_namespace *ns;
trace = (struct ioam6_trace_hdr *)(skb_transport_header(skb)
+ sizeof(struct ipv6_hopopt_hdr) + 2
+ sizeof(struct ioam6_hdr));
ns = ioam6_namespace(net, trace->namespace_id);
if (ns)
ioam6_fill_trace_data(skb, ns, trace, false);
return 0;
}
static int ioam6_do_inline(struct net *net, struct sk_buff *skb,
struct ioam6_lwt_encap *tuninfo)
{
struct ipv6hdr *oldhdr, *hdr;
int hdrlen, err;
hdrlen = (tuninfo->eh.hdrlen + 1) << 3;
@ -168,79 +211,195 @@ static int ioam6_do_inline(struct sk_buff *skb, struct ioam6_lwt_encap *tuninfo)
hdr->nexthdr = NEXTHDR_HOP;
hdr->payload_len = cpu_to_be16(skb->len - sizeof(*hdr));
trace = (struct ioam6_trace_hdr *)(skb_transport_header(skb)
+ sizeof(struct ipv6_hopopt_hdr) + 2
+ sizeof(struct ioam6_hdr));
return ioam6_do_fill(net, skb);
}
ns = ioam6_namespace(dev_net(skb_dst(skb)->dev), trace->namespace_id);
if (ns)
ioam6_fill_trace_data(skb, ns, trace);
static int ioam6_do_encap(struct net *net, struct sk_buff *skb,
struct ioam6_lwt_encap *tuninfo,
struct in6_addr *tundst)
{
struct dst_entry *dst = skb_dst(skb);
struct ipv6hdr *hdr, *inner_hdr;
int hdrlen, len, err;
return 0;
hdrlen = (tuninfo->eh.hdrlen + 1) << 3;
len = sizeof(*hdr) + hdrlen;
err = skb_cow_head(skb, len + skb->mac_len);
if (unlikely(err))
return err;
inner_hdr = ipv6_hdr(skb);
skb_push(skb, len);
skb_reset_network_header(skb);
skb_mac_header_rebuild(skb);
skb_set_transport_header(skb, sizeof(*hdr));
tuninfo->eh.nexthdr = NEXTHDR_IPV6;
memcpy(skb_transport_header(skb), (u8 *)tuninfo, hdrlen);
hdr = ipv6_hdr(skb);
memcpy(hdr, inner_hdr, sizeof(*hdr));
hdr->nexthdr = NEXTHDR_HOP;
hdr->payload_len = cpu_to_be16(skb->len - sizeof(*hdr));
hdr->daddr = *tundst;
ipv6_dev_get_saddr(net, dst->dev, &hdr->daddr,
IPV6_PREFER_SRC_PUBLIC, &hdr->saddr);
skb_postpush_rcsum(skb, hdr, len);
return ioam6_do_fill(net, skb);
}
static int ioam6_output(struct net *net, struct sock *sk, struct sk_buff *skb)
{
struct lwtunnel_state *lwt = skb_dst(skb)->lwtstate;
struct dst_entry *dst = skb_dst(skb);
struct in6_addr orig_daddr;
struct ioam6_lwt *ilwt;
int err = -EINVAL;
if (skb->protocol != htons(ETH_P_IPV6))
goto drop;
/* Only for packets we send and
* that do not contain a Hop-by-Hop yet
*/
if (skb->dev || ipv6_hdr(skb)->nexthdr == NEXTHDR_HOP)
goto out;
ilwt = ioam6_lwt_state(dst->lwtstate);
orig_daddr = ipv6_hdr(skb)->daddr;
err = ioam6_do_inline(skb, ioam6_lwt_info(lwt));
switch (ilwt->mode) {
case IOAM6_IPTUNNEL_MODE_INLINE:
do_inline:
/* Direct insertion - if there is no Hop-by-Hop yet */
if (ipv6_hdr(skb)->nexthdr == NEXTHDR_HOP)
goto out;
err = ioam6_do_inline(net, skb, &ilwt->tuninfo);
if (unlikely(err))
goto drop;
break;
case IOAM6_IPTUNNEL_MODE_ENCAP:
do_encap:
/* Encapsulation (ip6ip6) */
err = ioam6_do_encap(net, skb, &ilwt->tuninfo, &ilwt->tundst);
if (unlikely(err))
goto drop;
break;
case IOAM6_IPTUNNEL_MODE_AUTO:
/* Automatic (RFC8200 compliant):
* - local packets -> INLINE mode
* - in-transit packets -> ENCAP mode
*/
if (!skb->dev)
goto do_inline;
goto do_encap;
default:
goto drop;
}
err = skb_cow_head(skb, LL_RESERVED_SPACE(dst->dev));
if (unlikely(err))
goto drop;
err = skb_cow_head(skb, LL_RESERVED_SPACE(skb_dst(skb)->dev));
if (unlikely(err))
goto drop;
if (!ipv6_addr_equal(&orig_daddr, &ipv6_hdr(skb)->daddr)) {
preempt_disable();
dst = dst_cache_get(&ilwt->cache);
preempt_enable();
if (unlikely(!dst)) {
struct ipv6hdr *hdr = ipv6_hdr(skb);
struct flowi6 fl6;
memset(&fl6, 0, sizeof(fl6));
fl6.daddr = hdr->daddr;
fl6.saddr = hdr->saddr;
fl6.flowlabel = ip6_flowinfo(hdr);
fl6.flowi6_mark = skb->mark;
fl6.flowi6_proto = hdr->nexthdr;
dst = ip6_route_output(net, NULL, &fl6);
if (dst->error) {
err = dst->error;
dst_release(dst);
goto drop;
}
preempt_disable();
dst_cache_set_ip6(&ilwt->cache, dst, &fl6.saddr);
preempt_enable();
}
skb_dst_drop(skb);
skb_dst_set(skb, dst);
return dst_output(net, sk, skb);
}
out:
return lwt->orig_output(net, sk, skb);
return dst->lwtstate->orig_output(net, sk, skb);
drop:
kfree_skb(skb);
return err;
}
static void ioam6_destroy_state(struct lwtunnel_state *lwt)
{
dst_cache_destroy(&ioam6_lwt_state(lwt)->cache);
}
static int ioam6_fill_encap_info(struct sk_buff *skb,
struct lwtunnel_state *lwtstate)
{
struct ioam6_trace_hdr *trace;
struct ioam6_lwt *ilwt = ioam6_lwt_state(lwtstate);
int err;
trace = ioam6_lwt_trace(lwtstate);
err = nla_put(skb, IOAM6_IPTUNNEL_TRACE, sizeof(*trace), trace);
err = nla_put_u8(skb, IOAM6_IPTUNNEL_MODE, ilwt->mode);
if (err)
return err;
goto ret;
return 0;
if (ilwt->mode != IOAM6_IPTUNNEL_MODE_INLINE) {
err = nla_put_in6_addr(skb, IOAM6_IPTUNNEL_DST, &ilwt->tundst);
if (err)
goto ret;
}
err = nla_put(skb, IOAM6_IPTUNNEL_TRACE, sizeof(ilwt->tuninfo.traceh),
&ilwt->tuninfo.traceh);
ret:
return err;
}
static int ioam6_encap_nlsize(struct lwtunnel_state *lwtstate)
{
struct ioam6_trace_hdr *trace = ioam6_lwt_trace(lwtstate);
struct ioam6_lwt *ilwt = ioam6_lwt_state(lwtstate);
int nlsize;
return nla_total_size(sizeof(*trace));
nlsize = nla_total_size(sizeof(ilwt->mode)) +
nla_total_size(sizeof(ilwt->tuninfo.traceh));
if (ilwt->mode != IOAM6_IPTUNNEL_MODE_INLINE)
nlsize += nla_total_size(sizeof(ilwt->tundst));
return nlsize;
}
static int ioam6_encap_cmp(struct lwtunnel_state *a, struct lwtunnel_state *b)
{
struct ioam6_trace_hdr *a_hdr = ioam6_lwt_trace(a);
struct ioam6_trace_hdr *b_hdr = ioam6_lwt_trace(b);
struct ioam6_trace_hdr *trace_a = ioam6_lwt_trace(a);
struct ioam6_trace_hdr *trace_b = ioam6_lwt_trace(b);
struct ioam6_lwt *ilwt_a = ioam6_lwt_state(a);
struct ioam6_lwt *ilwt_b = ioam6_lwt_state(b);
return (a_hdr->namespace_id != b_hdr->namespace_id);
return (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);
}
static const struct lwtunnel_encap_ops ioam6_iptun_ops = {
.build_state = ioam6_build_state,
.destroy_state = ioam6_destroy_state,
.output = ioam6_output,
.fill_encap = ioam6_fill_encap_info,
.get_encap_size = ioam6_encap_nlsize,