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Diffstat (limited to 'net/ipv6/ioam6_iptunnel.c')
-rw-r--r--net/ipv6/ioam6_iptunnel.c477
1 files changed, 477 insertions, 0 deletions
diff --git a/net/ipv6/ioam6_iptunnel.c b/net/ipv6/ioam6_iptunnel.c
new file mode 100644
index 000000000..f6f5b83dd
--- /dev/null
+++ b/net/ipv6/ioam6_iptunnel.c
@@ -0,0 +1,477 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * IPv6 IOAM Lightweight Tunnel implementation
+ *
+ * Author:
+ * Justin Iurman <justin.iurman@uliege.be>
+ */
+
+#include <linux/kernel.h>
+#include <linux/skbuff.h>
+#include <linux/net.h>
+#include <linux/in6.h>
+#include <linux/ioam6.h>
+#include <linux/ioam6_iptunnel.h>
+#include <net/dst.h>
+#include <net/sock.h>
+#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
+
+struct ioam6_lwt_encap {
+ struct ipv6_hopopt_hdr eh;
+ u8 pad[2]; /* 2-octet padding for 4n-alignment */
+ struct ioam6_hdr ioamh;
+ 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;
+}
+
+static struct ioam6_lwt_encap *ioam6_lwt_info(struct lwtunnel_state *lwt)
+{
+ return &ioam6_lwt_state(lwt)->tuninfo;
+}
+
+static struct ioam6_trace_hdr *ioam6_lwt_trace(struct lwtunnel_state *lwt)
+{
+ return &(ioam6_lwt_state(lwt)->tuninfo.traceh);
+}
+
+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),
+ [IOAM6_IPTUNNEL_DST] = NLA_POLICY_EXACT_LEN(sizeof(struct in6_addr)),
+ [IOAM6_IPTUNNEL_TRACE] = NLA_POLICY_EXACT_LEN(sizeof(struct ioam6_trace_hdr)),
+};
+
+static bool ioam6_validate_trace_hdr(struct ioam6_trace_hdr *trace)
+{
+ u32 fields;
+
+ if (!trace->type_be32 || !trace->remlen ||
+ trace->remlen > IOAM6_TRACE_DATA_SIZE_MAX / 4 ||
+ trace->type.bit12 | trace->type.bit13 | trace->type.bit14 |
+ trace->type.bit15 | trace->type.bit16 | trace->type.bit17 |
+ trace->type.bit18 | trace->type.bit19 | trace->type.bit20 |
+ trace->type.bit21)
+ return false;
+
+ trace->nodelen = 0;
+ fields = be32_to_cpu(trace->type_be32);
+
+ trace->nodelen += hweight32(fields & IOAM6_MASK_SHORT_FIELDS)
+ * (sizeof(__be32) / 4);
+ trace->nodelen += hweight32(fields & IOAM6_MASK_WIDE_FIELDS)
+ * (sizeof(__be64) / 4);
+
+ return true;
+}
+
+static int ioam6_build_state(struct net *net, struct nlattr *nla,
+ unsigned int family, const void *cfg,
+ struct lwtunnel_state **ts,
+ struct netlink_ext_ack *extack)
+{
+ struct nlattr *tb[IOAM6_IPTUNNEL_MAX + 1];
+ struct ioam6_lwt_encap *tuninfo;
+ struct ioam6_trace_hdr *trace;
+ struct lwtunnel_state *lwt;
+ struct ioam6_lwt *ilwt;
+ int len_aligned, err;
+ u32 freq_k, freq_n;
+ u8 mode;
+
+ if (family != AF_INET6)
+ return -EINVAL;
+
+ err = nla_parse_nested(tb, IOAM6_IPTUNNEL_MAX, nla,
+ ioam6_iptunnel_policy, extack);
+ 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
+ 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;
+ }
+
+ trace = nla_data(tb[IOAM6_IPTUNNEL_TRACE]);
+ if (!ioam6_validate_trace_hdr(trace)) {
+ NL_SET_ERR_MSG_ATTR(extack, tb[IOAM6_IPTUNNEL_TRACE],
+ "invalid trace validation");
+ return -EINVAL;
+ }
+
+ len_aligned = ALIGN(trace->remlen * 4, 8);
+ lwt = lwtunnel_state_alloc(sizeof(*ilwt) + len_aligned);
+ if (!lwt)
+ return -ENOMEM;
+
+ ilwt = ioam6_lwt_state(lwt);
+ err = dst_cache_init(&ilwt->cache, GFP_ATOMIC);
+ if (err) {
+ kfree(lwt);
+ 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]);
+
+ 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;
+ tuninfo->ioamh.opt_len = sizeof(tuninfo->ioamh) - 2 + sizeof(*trace)
+ + trace->remlen * 4;
+
+ memcpy(&tuninfo->traceh, trace, sizeof(*trace));
+
+ if (len_aligned - trace->remlen * 4) {
+ tuninfo->traceh.data[trace->remlen * 4] = IPV6_TLV_PADN;
+ tuninfo->traceh.data[trace->remlen * 4 + 1] = 2;
+ }
+
+ lwt->type = LWTUNNEL_ENCAP_IOAM6;
+ lwt->flags |= LWTUNNEL_STATE_OUTPUT_REDIRECT;
+
+ *ts = lwt;
+
+ return 0;
+}
+
+static int ioam6_do_fill(struct net *net, struct sk_buff *skb)
+{
+ struct ioam6_trace_hdr *trace;
+ 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;
+
+ err = skb_cow_head(skb, hdrlen + skb->mac_len);
+ if (unlikely(err))
+ return err;
+
+ oldhdr = ipv6_hdr(skb);
+ skb_pull(skb, sizeof(*oldhdr));
+ skb_postpull_rcsum(skb, skb_network_header(skb), sizeof(*oldhdr));
+
+ skb_push(skb, sizeof(*oldhdr) + hdrlen);
+ skb_reset_network_header(skb);
+ skb_mac_header_rebuild(skb);
+
+ hdr = ipv6_hdr(skb);
+ memmove(hdr, oldhdr, sizeof(*oldhdr));
+ tuninfo->eh.nexthdr = hdr->nexthdr;
+
+ skb_set_transport_header(skb, sizeof(*hdr));
+ skb_postpush_rcsum(skb, hdr, sizeof(*hdr) + hdrlen);
+
+ memcpy(skb_transport_header(skb), (u8 *)tuninfo, hdrlen);
+
+ hdr->nexthdr = NEXTHDR_HOP;
+ hdr->payload_len = cpu_to_be16(skb->len - sizeof(*hdr));
+
+ return ioam6_do_fill(net, skb);
+}
+
+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;
+
+ 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 dst_entry *dst = skb_dst(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) {
+ 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;
+
+ 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 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_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;
+
+ 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_lwt *ilwt = ioam6_lwt_state(lwtstate);
+ int nlsize;
+
+ 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)
+ 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 *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 (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);
+}
+
+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,
+ .cmp_encap = ioam6_encap_cmp,
+ .owner = THIS_MODULE,
+};
+
+int __init ioam6_iptunnel_init(void)
+{
+ return lwtunnel_encap_add_ops(&ioam6_iptun_ops, LWTUNNEL_ENCAP_IOAM6);
+}
+
+void ioam6_iptunnel_exit(void)
+{
+ lwtunnel_encap_del_ops(&ioam6_iptun_ops, LWTUNNEL_ENCAP_IOAM6);
+}