9 files changed, 407 insertions, 2 deletions

diff --git a/include/linux/seg6_local.h b/include/linux/seg6_local.h
new file mode 100644
index 000000000000..ee63e76fe0c7
--- /dev/null
+++ b/include/linux/seg6_local.h
@@ -0,0 +1,6 @@
+#ifndef _LINUX_SEG6_LOCAL_H
+#define _LINUX_SEG6_LOCAL_H
+
+#include <uapi/linux/seg6_local.h>
+
+#endif
diff --git a/include/net/seg6.h b/include/net/seg6.h
index a32abb040e1d..5379f550f521 100644
--- a/include/net/seg6.h
+++ b/include/net/seg6.h
@@ -56,6 +56,8 @@ extern int seg6_init(void);
 extern void seg6_exit(void);
 extern int seg6_iptunnel_init(void);
 extern void seg6_iptunnel_exit(void);
+extern int seg6_local_init(void);
+extern void seg6_local_exit(void);
 
 extern bool seg6_validate_srh(struct ipv6_sr_hdr *srh, int len);
 extern int seg6_do_srh_encap(struct sk_buff *skb, struct ipv6_sr_hdr *osrh);
diff --git a/include/uapi/linux/lwtunnel.h b/include/uapi/linux/lwtunnel.h
index 92724cba1eba..7fdd19ca7511 100644
--- a/include/uapi/linux/lwtunnel.h
+++ b/include/uapi/linux/lwtunnel.h
@@ -11,6 +11,7 @@ enum lwtunnel_encap_types {
         LWTUNNEL_ENCAP_IP6,
         LWTUNNEL_ENCAP_SEG6,
         LWTUNNEL_ENCAP_BPF,
+        LWTUNNEL_ENCAP_SEG6_LOCAL,
         __LWTUNNEL_ENCAP_MAX,
 };
 
diff --git a/include/uapi/linux/seg6_local.h b/include/uapi/linux/seg6_local.h
new file mode 100644
index 000000000000..ef2d8c3e76c1
--- /dev/null
+++ b/include/uapi/linux/seg6_local.h
@@ -0,0 +1,68 @@
+/*
+ *  SR-IPv6 implementation
+ *
+ *  Author:
+ *  David Lebrun <david.lebrun@uclouvain.be>
+ *
+ *
+ *  This program is free software; you can redistribute it and/or
+ *      modify it under the terms of the GNU General Public License
+ *      as published by the Free Software Foundation; either version
+ *      2 of the License, or (at your option) any later version.
+ */
+
+#ifndef _UAPI_LINUX_SEG6_LOCAL_H
+#define _UAPI_LINUX_SEG6_LOCAL_H
+
+#include <linux/seg6.h>
+
+enum {
+        SEG6_LOCAL_UNSPEC,
+        SEG6_LOCAL_ACTION,
+        SEG6_LOCAL_SRH,
+        SEG6_LOCAL_TABLE,
+        SEG6_LOCAL_NH4,
+        SEG6_LOCAL_NH6,
+        SEG6_LOCAL_IIF,
+        SEG6_LOCAL_OIF,
+        __SEG6_LOCAL_MAX,
+};
+#define SEG6_LOCAL_MAX (__SEG6_LOCAL_MAX - 1)
+
+enum {
+        SEG6_LOCAL_ACTION_UNSPEC        = 0,
+        /* node segment */
+        SEG6_LOCAL_ACTION_END           = 1,
+        /* adjacency segment (IPv6 cross-connect) */
+        SEG6_LOCAL_ACTION_END_X         = 2,
+        /* lookup of next seg NH in table */
+        SEG6_LOCAL_ACTION_END_T         = 3,
+        /* decap and L2 cross-connect */
+        SEG6_LOCAL_ACTION_END_DX2       = 4,
+        /* decap and IPv6 cross-connect */
+        SEG6_LOCAL_ACTION_END_DX6       = 5,
+        /* decap and IPv4 cross-connect */
+        SEG6_LOCAL_ACTION_END_DX4       = 6,
+        /* decap and lookup of DA in v6 table */
+        SEG6_LOCAL_ACTION_END_DT6       = 7,
+        /* decap and lookup of DA in v4 table */
+        SEG6_LOCAL_ACTION_END_DT4       = 8,
+        /* binding segment with insertion */
+        SEG6_LOCAL_ACTION_END_B6        = 9,
+        /* binding segment with encapsulation */
+        SEG6_LOCAL_ACTION_END_B6_ENCAP  = 10,
+        /* binding segment with MPLS encap */
+        SEG6_LOCAL_ACTION_END_BM        = 11,
+        /* lookup last seg in table */
+        SEG6_LOCAL_ACTION_END_S         = 12,
+        /* forward to SR-unaware VNF with static proxy */
+        SEG6_LOCAL_ACTION_END_AS        = 13,
+        /* forward to SR-unaware VNF with masquerading */
+        SEG6_LOCAL_ACTION_END_AM        = 14,
+
+        __SEG6_LOCAL_ACTION_MAX,
+};
+
+#define SEG6_LOCAL_ACTION_MAX (__SEG6_LOCAL_ACTION_MAX - 1)
+
+#endif
diff --git a/net/core/lwtunnel.c b/net/core/lwtunnel.c
index 435f35f9a61c..0b171756453c 100644
--- a/net/core/lwtunnel.c
+++ b/net/core/lwtunnel.c
@@ -44,6 +44,8 @@ static const char *lwtunnel_encap_str(enum lwtunnel_encap_types encap_type)
                 return "SEG6";
         case LWTUNNEL_ENCAP_BPF:
                 return "BPF";
+        case LWTUNNEL_ENCAP_SEG6_LOCAL:
+                return "SEG6LOCAL";
         case LWTUNNEL_ENCAP_IP6:
         case LWTUNNEL_ENCAP_IP:
         case LWTUNNEL_ENCAP_NONE:
diff --git a/net/ipv6/Kconfig b/net/ipv6/Kconfig
index 50181a96923e..0d722396dce6 100644
--- a/net/ipv6/Kconfig
+++ b/net/ipv6/Kconfig
@@ -311,7 +311,8 @@ config IPV6_SEG6_LWTUNNEL
         ---help---
           Support for encapsulation of packets within an outer IPv6
           header and a Segment Routing Header using the lightweight
-          tunnels mechanism.
+          tunnels mechanism. Also enable support for advanced local
+          processing of SRv6 packets based on their active segment.
 
           If unsure, say N.
 
diff --git a/net/ipv6/Makefile b/net/ipv6/Makefile
index f8b24c2e0d77..10e342363793 100644
--- a/net/ipv6/Makefile
+++ b/net/ipv6/Makefile
@@ -23,7 +23,7 @@ ipv6-$(CONFIG_IPV6_MULTIPLE_TABLES) += fib6_rules.o
 ipv6-$(CONFIG_PROC_FS) += proc.o
 ipv6-$(CONFIG_SYN_COOKIES) += syncookies.o
 ipv6-$(CONFIG_NETLABEL) += calipso.o
-ipv6-$(CONFIG_IPV6_SEG6_LWTUNNEL) += seg6_iptunnel.o
+ipv6-$(CONFIG_IPV6_SEG6_LWTUNNEL) += seg6_iptunnel.o seg6_local.o
 ipv6-$(CONFIG_IPV6_SEG6_HMAC) += seg6_hmac.o
 
 ipv6-objs += $(ipv6-y)
diff --git a/net/ipv6/seg6.c b/net/ipv6/seg6.c
index 81c2339b3285..c81407770956 100644
--- a/net/ipv6/seg6.c
+++ b/net/ipv6/seg6.c
@@ -456,6 +456,10 @@ int __init seg6_init(void)
         err = seg6_iptunnel_init();
         if (err)
                 goto out_unregister_pernet;
+
+        err = seg6_local_init();
+        if (err)
+                goto out_unregister_pernet;
 #endif
 
 #ifdef CONFIG_IPV6_SEG6_HMAC
@@ -471,6 +475,7 @@ out:
 #ifdef CONFIG_IPV6_SEG6_HMAC
 out_unregister_iptun:
 #ifdef CONFIG_IPV6_SEG6_LWTUNNEL
+        seg6_local_exit();
         seg6_iptunnel_exit();
 #endif
 #endif
diff --git a/net/ipv6/seg6_local.c b/net/ipv6/seg6_local.c
new file mode 100644
index 000000000000..53615d7e0723
--- /dev/null
+++ b/net/ipv6/seg6_local.c
@@ -0,0 +1,320 @@
+/*
+ *  SR-IPv6 implementation
+ *
+ *  Author:
+ *  David Lebrun <david.lebrun@uclouvain.be>
+ *
+ *
+ *  This program is free software; you can redistribute it and/or
+ *        modify it under the terms of the GNU General Public License
+ *        as published by the Free Software Foundation; either version
+ *        2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/types.h>
+#include <linux/skbuff.h>
+#include <linux/net.h>
+#include <linux/module.h>
+#include <net/ip.h>
+#include <net/lwtunnel.h>
+#include <net/netevent.h>
+#include <net/netns/generic.h>
+#include <net/ip6_fib.h>
+#include <net/route.h>
+#include <net/seg6.h>
+#include <linux/seg6.h>
+#include <linux/seg6_local.h>
+#include <net/addrconf.h>
+#include <net/ip6_route.h>
+#include <net/dst_cache.h>
+#ifdef CONFIG_IPV6_SEG6_HMAC
+#include <net/seg6_hmac.h>
+#endif
+
+struct seg6_local_lwt;
+
+struct seg6_action_desc {
+        int action;
+        unsigned long attrs;
+        int (*input)(struct sk_buff *skb, struct seg6_local_lwt *slwt);
+        int static_headroom;
+};
+
+struct seg6_local_lwt {
+        int action;
+        struct ipv6_sr_hdr *srh;
+        int table;
+        struct in_addr nh4;
+        struct in6_addr nh6;
+        int iif;
+        int oif;
+
+        int headroom;
+        struct seg6_action_desc *desc;
+};
+
+static struct seg6_local_lwt *seg6_local_lwtunnel(struct lwtunnel_state *lwt)
+{
+        return (struct seg6_local_lwt *)lwt->data;
+}
+
+static struct seg6_action_desc seg6_action_table[] = {
+        {
+                .action         = SEG6_LOCAL_ACTION_END,
+                .attrs          = 0,
+        },
+};
+
+static struct seg6_action_desc *__get_action_desc(int action)
+{
+        struct seg6_action_desc *desc;
+        int i, count;
+
+        count = sizeof(seg6_action_table) / sizeof(struct seg6_action_desc);
+        for (i = 0; i < count; i++) {
+                desc = &seg6_action_table[i];
+                if (desc->action == action)
+                        return desc;
+        }
+
+        return NULL;
+}
+
+static int seg6_local_input(struct sk_buff *skb)
+{
+        struct dst_entry *orig_dst = skb_dst(skb);
+        struct seg6_action_desc *desc;
+        struct seg6_local_lwt *slwt;
+
+        slwt = seg6_local_lwtunnel(orig_dst->lwtstate);
+        desc = slwt->desc;
+
+        return desc->input(skb, slwt);
+}
+
+static const struct nla_policy seg6_local_policy[SEG6_LOCAL_MAX + 1] = {
+        [SEG6_LOCAL_ACTION]     = { .type = NLA_U32 },
+        [SEG6_LOCAL_SRH]        = { .type = NLA_BINARY },
+        [SEG6_LOCAL_TABLE]      = { .type = NLA_U32 },
+        [SEG6_LOCAL_NH4]        = { .type = NLA_BINARY,
+                                    .len = sizeof(struct in_addr) },
+        [SEG6_LOCAL_NH6]        = { .type = NLA_BINARY,
+                                    .len = sizeof(struct in6_addr) },
+        [SEG6_LOCAL_IIF]        = { .type = NLA_U32 },
+        [SEG6_LOCAL_OIF]        = { .type = NLA_U32 },
+};
+
+struct seg6_action_param {
+        int (*parse)(struct nlattr **attrs, struct seg6_local_lwt *slwt);
+        int (*put)(struct sk_buff *skb, struct seg6_local_lwt *slwt);
+        int (*cmp)(struct seg6_local_lwt *a, struct seg6_local_lwt *b);
+};
+
+static struct seg6_action_param seg6_action_params[SEG6_LOCAL_MAX + 1] = {
+        [SEG6_LOCAL_SRH]        = { .parse = NULL,
+                                    .put = NULL,
+                                    .cmp = NULL },
+
+        [SEG6_LOCAL_TABLE]      = { .parse = NULL,
+                                    .put = NULL,
+                                    .cmp = NULL },
+
+        [SEG6_LOCAL_NH4]        = { .parse = NULL,
+                                    .put = NULL,
+                                    .cmp = NULL },
+
+        [SEG6_LOCAL_NH6]        = { .parse = NULL,
+                                    .put = NULL,
+                                    .cmp = NULL },
+
+        [SEG6_LOCAL_IIF]        = { .parse = NULL,
+                                    .put = NULL,
+                                    .cmp = NULL },
+
+        [SEG6_LOCAL_OIF]        = { .parse = NULL,
+                                    .put = NULL,
+                                    .cmp = NULL },
+};
+
+static int parse_nla_action(struct nlattr **attrs, struct seg6_local_lwt *slwt)
+{
+        struct seg6_action_param *param;
+        struct seg6_action_desc *desc;
+        int i, err;
+
+        desc = __get_action_desc(slwt->action);
+        if (!desc)
+                return -EINVAL;
+
+        if (!desc->input)
+                return -EOPNOTSUPP;
+
+        slwt->desc = desc;
+        slwt->headroom += desc->static_headroom;
+
+        for (i = 0; i < SEG6_LOCAL_MAX + 1; i++) {
+                if (desc->attrs & (1 << i)) {
+                        if (!attrs[i])
+                                return -EINVAL;
+
+                        param = &seg6_action_params[i];
+
+                        err = param->parse(attrs, slwt);
+                        if (err < 0)
+                                return err;
+                }
+        }
+
+        return 0;
+}
+
+static int seg6_local_build_state(struct nlattr *nla, unsigned int family,
+                                  const void *cfg, struct lwtunnel_state **ts,
+                                  struct netlink_ext_ack *extack)
+{
+        struct nlattr *tb[SEG6_LOCAL_MAX + 1];
+        struct lwtunnel_state *newts;
+        struct seg6_local_lwt *slwt;
+        int err;
+
+        err = nla_parse_nested(tb, SEG6_LOCAL_MAX, nla, seg6_local_policy,
+                               extack);
+
+        if (err < 0)
+                return err;
+
+        if (!tb[SEG6_LOCAL_ACTION])
+                return -EINVAL;
+
+        newts = lwtunnel_state_alloc(sizeof(*slwt));
+        if (!newts)
+                return -ENOMEM;
+
+        slwt = seg6_local_lwtunnel(newts);
+        slwt->action = nla_get_u32(tb[SEG6_LOCAL_ACTION]);
+
+        err = parse_nla_action(tb, slwt);
+        if (err < 0)
+                goto out_free;
+
+        newts->type = LWTUNNEL_ENCAP_SEG6_LOCAL;
+        newts->flags = LWTUNNEL_STATE_INPUT_REDIRECT;
+        newts->headroom = slwt->headroom;
+
+        *ts = newts;
+
+        return 0;
+
+out_free:
+        kfree(slwt->srh);
+        kfree(newts);
+        return err;
+}
+
+static void seg6_local_destroy_state(struct lwtunnel_state *lwt)
+{
+        struct seg6_local_lwt *slwt = seg6_local_lwtunnel(lwt);
+
+        kfree(slwt->srh);
+}
+
+static int seg6_local_fill_encap(struct sk_buff *skb,
+                                 struct lwtunnel_state *lwt)
+{
+        struct seg6_local_lwt *slwt = seg6_local_lwtunnel(lwt);
+        struct seg6_action_param *param;
+        int i, err;
+
+        if (nla_put_u32(skb, SEG6_LOCAL_ACTION, slwt->action))
+                return -EMSGSIZE;
+
+        for (i = 0; i < SEG6_LOCAL_MAX + 1; i++) {
+                if (slwt->desc->attrs & (1 << i)) {
+                        param = &seg6_action_params[i];
+                        err = param->put(skb, slwt);
+                        if (err < 0)
+                                return err;
+                }
+        }
+
+        return 0;
+}
+
+static int seg6_local_get_encap_size(struct lwtunnel_state *lwt)
+{
+        struct seg6_local_lwt *slwt = seg6_local_lwtunnel(lwt);
+        unsigned long attrs;
+        int nlsize;
+
+        nlsize = nla_total_size(4); /* action */
+
+        attrs = slwt->desc->attrs;
+
+        if (attrs & (1 << SEG6_LOCAL_SRH))
+                nlsize += nla_total_size((slwt->srh->hdrlen + 1) << 3);
+
+        if (attrs & (1 << SEG6_LOCAL_TABLE))
+                nlsize += nla_total_size(4);
+
+        if (attrs & (1 << SEG6_LOCAL_NH4))
+                nlsize += nla_total_size(4);
+
+        if (attrs & (1 << SEG6_LOCAL_NH6))
+                nlsize += nla_total_size(16);
+
+        if (attrs & (1 << SEG6_LOCAL_IIF))
+                nlsize += nla_total_size(4);
+
+        if (attrs & (1 << SEG6_LOCAL_OIF))
+                nlsize += nla_total_size(4);
+
+        return nlsize;
+}
+
+static int seg6_local_cmp_encap(struct lwtunnel_state *a,
+                                struct lwtunnel_state *b)
+{
+        struct seg6_local_lwt *slwt_a, *slwt_b;
+        struct seg6_action_param *param;
+        int i;
+
+        slwt_a = seg6_local_lwtunnel(a);
+        slwt_b = seg6_local_lwtunnel(b);
+
+        if (slwt_a->action != slwt_b->action)
+                return 1;
+
+        if (slwt_a->desc->attrs != slwt_b->desc->attrs)
+                return 1;
+
+        for (i = 0; i < SEG6_LOCAL_MAX + 1; i++) {
+                if (slwt_a->desc->attrs & (1 << i)) {
+                        param = &seg6_action_params[i];
+                        if (param->cmp(slwt_a, slwt_b))
+                                return 1;
+                }
+        }
+
+        return 0;
+}
+
+static const struct lwtunnel_encap_ops seg6_local_ops = {
+        .build_state    = seg6_local_build_state,
+        .destroy_state  = seg6_local_destroy_state,
+        .input          = seg6_local_input,
+        .fill_encap     = seg6_local_fill_encap,
+        .get_encap_size = seg6_local_get_encap_size,
+        .cmp_encap      = seg6_local_cmp_encap,
+        .owner          = THIS_MODULE,
+};
+
+int __init seg6_local_init(void)
+{
+        return lwtunnel_encap_add_ops(&seg6_local_ops,
+                                      LWTUNNEL_ENCAP_SEG6_LOCAL);
+}
+
+void seg6_local_exit(void)
+{
+        lwtunnel_encap_del_ops(&seg6_local_ops, LWTUNNEL_ENCAP_SEG6_LOCAL);
+}