1 files changed, 508 insertions, 0 deletions
diff --git a/net/ipv6/seg6.c b/net/ipv6/seg6.c
new file mode 100644
index 000000000..2278c0234
--- /dev/null
+++ b/net/ipv6/seg6.c
@@ -0,0 +1,508 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  SR-IPv6 implementation
+ *
+ *  Author:
+ *  David Lebrun <david.lebrun@uclouvain.be>
+ */
+
+#include <linux/errno.h>
+#include <linux/types.h>
+#include <linux/socket.h>
+#include <linux/net.h>
+#include <linux/in6.h>
+#include <linux/slab.h>
+#include <linux/rhashtable.h>
+
+#include <net/ipv6.h>
+#include <net/protocol.h>
+
+#include <net/seg6.h>
+#include <net/genetlink.h>
+#include <linux/seg6.h>
+#include <linux/seg6_genl.h>
+#ifdef CONFIG_IPV6_SEG6_HMAC
+#include <net/seg6_hmac.h>
+#endif
+
+bool seg6_validate_srh(struct ipv6_sr_hdr *srh, int len, bool reduced)
+{
+	unsigned int tlv_offset;
+	int max_last_entry;
+	int trailing;
+
+	if (srh->type != IPV6_SRCRT_TYPE_4)
+		return false;
+
+	if (((srh->hdrlen + 1) << 3) != len)
+		return false;
+
+	if (!reduced && srh->segments_left > srh->first_segment) {
+		return false;
+	} else {
+		max_last_entry = (srh->hdrlen / 2) - 1;
+
+		if (srh->first_segment > max_last_entry)
+			return false;
+
+		if (srh->segments_left > srh->first_segment + 1)
+			return false;
+	}
+
+	tlv_offset = sizeof(*srh) + ((srh->first_segment + 1) << 4);
+
+	trailing = len - tlv_offset;
+	if (trailing < 0)
+		return false;
+
+	while (trailing) {
+		struct sr6_tlv *tlv;
+		unsigned int tlv_len;
+
+		if (trailing < sizeof(*tlv))
+			return false;
+
+		tlv = (struct sr6_tlv *)((unsigned char *)srh + tlv_offset);
+		tlv_len = sizeof(*tlv) + tlv->len;
+
+		trailing -= tlv_len;
+		if (trailing < 0)
+			return false;
+
+		tlv_offset += tlv_len;
+	}
+
+	return true;
+}
+
+static struct genl_family seg6_genl_family;
+
+static const struct nla_policy seg6_genl_policy[SEG6_ATTR_MAX + 1] = {
+	[SEG6_ATTR_DST]				= { .type = NLA_BINARY,
+		.len = sizeof(struct in6_addr) },
+	[SEG6_ATTR_DSTLEN]			= { .type = NLA_S32, },
+	[SEG6_ATTR_HMACKEYID]		= { .type = NLA_U32, },
+	[SEG6_ATTR_SECRET]			= { .type = NLA_BINARY, },
+	[SEG6_ATTR_SECRETLEN]		= { .type = NLA_U8, },
+	[SEG6_ATTR_ALGID]			= { .type = NLA_U8, },
+	[SEG6_ATTR_HMACINFO]		= { .type = NLA_NESTED, },
+};
+
+#ifdef CONFIG_IPV6_SEG6_HMAC
+
+static int seg6_genl_sethmac(struct sk_buff *skb, struct genl_info *info)
+{
+	struct net *net = genl_info_net(info);
+	struct seg6_pernet_data *sdata;
+	struct seg6_hmac_info *hinfo;
+	u32 hmackeyid;
+	char *secret;
+	int err = 0;
+	u8 algid;
+	u8 slen;
+
+	sdata = seg6_pernet(net);
+
+	if (!info->attrs[SEG6_ATTR_HMACKEYID] ||
+	    !info->attrs[SEG6_ATTR_SECRETLEN] ||
+	    !info->attrs[SEG6_ATTR_ALGID])
+		return -EINVAL;
+
+	hmackeyid = nla_get_u32(info->attrs[SEG6_ATTR_HMACKEYID]);
+	slen = nla_get_u8(info->attrs[SEG6_ATTR_SECRETLEN]);
+	algid = nla_get_u8(info->attrs[SEG6_ATTR_ALGID]);
+
+	if (hmackeyid == 0)
+		return -EINVAL;
+
+	if (slen > SEG6_HMAC_SECRET_LEN)
+		return -EINVAL;
+
+	mutex_lock(&sdata->lock);
+	hinfo = seg6_hmac_info_lookup(net, hmackeyid);
+
+	if (!slen) {
+		if (!hinfo)
+			err = -ENOENT;
+
+		err = seg6_hmac_info_del(net, hmackeyid);
+
+		goto out_unlock;
+	}
+
+	if (!info->attrs[SEG6_ATTR_SECRET]) {
+		err = -EINVAL;
+		goto out_unlock;
+	}
+
+	if (slen > nla_len(info->attrs[SEG6_ATTR_SECRET])) {
+		err = -EINVAL;
+		goto out_unlock;
+	}
+
+	if (hinfo) {
+		err = seg6_hmac_info_del(net, hmackeyid);
+		if (err)
+			goto out_unlock;
+	}
+
+	secret = (char *)nla_data(info->attrs[SEG6_ATTR_SECRET]);
+
+	hinfo = kzalloc(sizeof(*hinfo), GFP_KERNEL);
+	if (!hinfo) {
+		err = -ENOMEM;
+		goto out_unlock;
+	}
+
+	memcpy(hinfo->secret, secret, slen);
+	hinfo->slen = slen;
+	hinfo->alg_id = algid;
+	hinfo->hmackeyid = hmackeyid;
+
+	err = seg6_hmac_info_add(net, hmackeyid, hinfo);
+	if (err)
+		kfree(hinfo);
+
+out_unlock:
+	mutex_unlock(&sdata->lock);
+	return err;
+}
+
+#else
+
+static int seg6_genl_sethmac(struct sk_buff *skb, struct genl_info *info)
+{
+	return -ENOTSUPP;
+}
+
+#endif
+
+static int seg6_genl_set_tunsrc(struct sk_buff *skb, struct genl_info *info)
+{
+	struct net *net = genl_info_net(info);
+	struct in6_addr *val, *t_old, *t_new;
+	struct seg6_pernet_data *sdata;
+
+	sdata = seg6_pernet(net);
+
+	if (!info->attrs[SEG6_ATTR_DST])
+		return -EINVAL;
+
+	val = nla_data(info->attrs[SEG6_ATTR_DST]);
+	t_new = kmemdup(val, sizeof(*val), GFP_KERNEL);
+	if (!t_new)
+		return -ENOMEM;
+
+	mutex_lock(&sdata->lock);
+
+	t_old = sdata->tun_src;
+	rcu_assign_pointer(sdata->tun_src, t_new);
+
+	mutex_unlock(&sdata->lock);
+
+	synchronize_net();
+	kfree(t_old);
+
+	return 0;
+}
+
+static int seg6_genl_get_tunsrc(struct sk_buff *skb, struct genl_info *info)
+{
+	struct net *net = genl_info_net(info);
+	struct in6_addr *tun_src;
+	struct sk_buff *msg;
+	void *hdr;
+
+	msg = genlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
+	if (!msg)
+		return -ENOMEM;
+
+	hdr = genlmsg_put(msg, info->snd_portid, info->snd_seq,
+			  &seg6_genl_family, 0, SEG6_CMD_GET_TUNSRC);
+	if (!hdr)
+		goto free_msg;
+
+	rcu_read_lock();
+	tun_src = rcu_dereference(seg6_pernet(net)->tun_src);
+
+	if (nla_put(msg, SEG6_ATTR_DST, sizeof(struct in6_addr), tun_src))
+		goto nla_put_failure;
+
+	rcu_read_unlock();
+
+	genlmsg_end(msg, hdr);
+	return genlmsg_reply(msg, info);
+
+nla_put_failure:
+	rcu_read_unlock();
+free_msg:
+	nlmsg_free(msg);
+	return -ENOMEM;
+}
+
+#ifdef CONFIG_IPV6_SEG6_HMAC
+
+static int __seg6_hmac_fill_info(struct seg6_hmac_info *hinfo,
+				 struct sk_buff *msg)
+{
+	if (nla_put_u32(msg, SEG6_ATTR_HMACKEYID, hinfo->hmackeyid) ||
+	    nla_put_u8(msg, SEG6_ATTR_SECRETLEN, hinfo->slen) ||
+	    nla_put(msg, SEG6_ATTR_SECRET, hinfo->slen, hinfo->secret) ||
+	    nla_put_u8(msg, SEG6_ATTR_ALGID, hinfo->alg_id))
+		return -1;
+
+	return 0;
+}
+
+static int __seg6_genl_dumphmac_element(struct seg6_hmac_info *hinfo,
+					u32 portid, u32 seq, u32 flags,
+					struct sk_buff *skb, u8 cmd)
+{
+	void *hdr;
+
+	hdr = genlmsg_put(skb, portid, seq, &seg6_genl_family, flags, cmd);
+	if (!hdr)
+		return -ENOMEM;
+
+	if (__seg6_hmac_fill_info(hinfo, skb) < 0)
+		goto nla_put_failure;
+
+	genlmsg_end(skb, hdr);
+	return 0;
+
+nla_put_failure:
+	genlmsg_cancel(skb, hdr);
+	return -EMSGSIZE;
+}
+
+static int seg6_genl_dumphmac_start(struct netlink_callback *cb)
+{
+	struct net *net = sock_net(cb->skb->sk);
+	struct seg6_pernet_data *sdata;
+	struct rhashtable_iter *iter;
+
+	sdata = seg6_pernet(net);
+	iter = (struct rhashtable_iter *)cb->args[0];
+
+	if (!iter) {
+		iter = kmalloc(sizeof(*iter), GFP_KERNEL);
+		if (!iter)
+			return -ENOMEM;
+
+		cb->args[0] = (long)iter;
+	}
+
+	rhashtable_walk_enter(&sdata->hmac_infos, iter);
+
+	return 0;
+}
+
+static int seg6_genl_dumphmac_done(struct netlink_callback *cb)
+{
+	struct rhashtable_iter *iter = (struct rhashtable_iter *)cb->args[0];
+
+	rhashtable_walk_exit(iter);
+
+	kfree(iter);
+
+	return 0;
+}
+
+static int seg6_genl_dumphmac(struct sk_buff *skb, struct netlink_callback *cb)
+{
+	struct rhashtable_iter *iter = (struct rhashtable_iter *)cb->args[0];
+	struct seg6_hmac_info *hinfo;
+	int ret;
+
+	rhashtable_walk_start(iter);
+
+	for (;;) {
+		hinfo = rhashtable_walk_next(iter);
+
+		if (IS_ERR(hinfo)) {
+			if (PTR_ERR(hinfo) == -EAGAIN)
+				continue;
+			ret = PTR_ERR(hinfo);
+			goto done;
+		} else if (!hinfo) {
+			break;
+		}
+
+		ret = __seg6_genl_dumphmac_element(hinfo,
+						   NETLINK_CB(cb->skb).portid,
+						   cb->nlh->nlmsg_seq,
+						   NLM_F_MULTI,
+						   skb, SEG6_CMD_DUMPHMAC);
+		if (ret)
+			goto done;
+	}
+
+	ret = skb->len;
+
+done:
+	rhashtable_walk_stop(iter);
+	return ret;
+}
+
+#else
+
+static int seg6_genl_dumphmac_start(struct netlink_callback *cb)
+{
+	return 0;
+}
+
+static int seg6_genl_dumphmac_done(struct netlink_callback *cb)
+{
+	return 0;
+}
+
+static int seg6_genl_dumphmac(struct sk_buff *skb, struct netlink_callback *cb)
+{
+	return -ENOTSUPP;
+}
+
+#endif
+
+static int __net_init seg6_net_init(struct net *net)
+{
+	struct seg6_pernet_data *sdata;
+
+	sdata = kzalloc(sizeof(*sdata), GFP_KERNEL);
+	if (!sdata)
+		return -ENOMEM;
+
+	mutex_init(&sdata->lock);
+
+	sdata->tun_src = kzalloc(sizeof(*sdata->tun_src), GFP_KERNEL);
+	if (!sdata->tun_src) {
+		kfree(sdata);
+		return -ENOMEM;
+	}
+
+	net->ipv6.seg6_data = sdata;
+
+#ifdef CONFIG_IPV6_SEG6_HMAC
+	seg6_hmac_net_init(net);
+#endif
+
+	return 0;
+}
+
+static void __net_exit seg6_net_exit(struct net *net)
+{
+	struct seg6_pernet_data *sdata = seg6_pernet(net);
+
+#ifdef CONFIG_IPV6_SEG6_HMAC
+	seg6_hmac_net_exit(net);
+#endif
+
+	kfree(sdata->tun_src);
+	kfree(sdata);
+}
+
+static struct pernet_operations ip6_segments_ops = {
+	.init = seg6_net_init,
+	.exit = seg6_net_exit,
+};
+
+static const struct genl_ops seg6_genl_ops[] = {
+	{
+		.cmd	= SEG6_CMD_SETHMAC,
+		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
+		.doit	= seg6_genl_sethmac,
+		.flags	= GENL_ADMIN_PERM,
+	},
+	{
+		.cmd	= SEG6_CMD_DUMPHMAC,
+		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
+		.start	= seg6_genl_dumphmac_start,
+		.dumpit	= seg6_genl_dumphmac,
+		.done	= seg6_genl_dumphmac_done,
+		.flags	= GENL_ADMIN_PERM,
+	},
+	{
+		.cmd	= SEG6_CMD_SET_TUNSRC,
+		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
+		.doit	= seg6_genl_set_tunsrc,
+		.flags	= GENL_ADMIN_PERM,
+	},
+	{
+		.cmd	= SEG6_CMD_GET_TUNSRC,
+		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
+		.doit	= seg6_genl_get_tunsrc,
+		.flags	= GENL_ADMIN_PERM,
+	},
+};
+
+static struct genl_family seg6_genl_family __ro_after_init = {
+	.hdrsize	= 0,
+	.name		= SEG6_GENL_NAME,
+	.version	= SEG6_GENL_VERSION,
+	.maxattr	= SEG6_ATTR_MAX,
+	.policy = seg6_genl_policy,
+	.netnsok	= true,
+	.parallel_ops	= true,
+	.ops		= seg6_genl_ops,
+	.n_ops		= ARRAY_SIZE(seg6_genl_ops),
+	.module		= THIS_MODULE,
+};
+
+int __init seg6_init(void)
+{
+	int err;
+
+	err = genl_register_family(&seg6_genl_family);
+	if (err)
+		goto out;
+
+	err = register_pernet_subsys(&ip6_segments_ops);
+	if (err)
+		goto out_unregister_genl;
+
+#ifdef CONFIG_IPV6_SEG6_LWTUNNEL
+	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
+	err = seg6_hmac_init();
+	if (err)
+		goto out_unregister_iptun;
+#endif
+
+	pr_info("Segment Routing with IPv6\n");
+
+out:
+	return err;
+#ifdef CONFIG_IPV6_SEG6_HMAC
+out_unregister_iptun:
+#ifdef CONFIG_IPV6_SEG6_LWTUNNEL
+	seg6_local_exit();
+	seg6_iptunnel_exit();
+#endif
+#endif
+#ifdef CONFIG_IPV6_SEG6_LWTUNNEL
+out_unregister_pernet:
+	unregister_pernet_subsys(&ip6_segments_ops);
+#endif
+out_unregister_genl:
+	genl_unregister_family(&seg6_genl_family);
+	goto out;
+}
+
+void seg6_exit(void)
+{
+#ifdef CONFIG_IPV6_SEG6_HMAC
+	seg6_hmac_exit();
+#endif
+#ifdef CONFIG_IPV6_SEG6_LWTUNNEL
+	seg6_iptunnel_exit();
+#endif
+	unregister_pernet_subsys(&ip6_segments_ops);
+	genl_unregister_family(&seg6_genl_family);
+}