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-rw-r--r--net/core/lwtunnel.c417
1 files changed, 417 insertions, 0 deletions
diff --git a/net/core/lwtunnel.c b/net/core/lwtunnel.c
new file mode 100644
index 000000000..0b1717564
--- /dev/null
+++ b/net/core/lwtunnel.c
@@ -0,0 +1,417 @@
+/*
+ * lwtunnel Infrastructure for light weight tunnels like mpls
+ *
+ * Authors: Roopa Prabhu, <roopa@cumulusnetworks.com>
+ *
+ * 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/capability.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <linux/skbuff.h>
+#include <linux/netdevice.h>
+#include <linux/lwtunnel.h>
+#include <linux/in.h>
+#include <linux/init.h>
+#include <linux/err.h>
+
+#include <net/lwtunnel.h>
+#include <net/rtnetlink.h>
+#include <net/ip6_fib.h>
+#include <net/nexthop.h>
+
+#ifdef CONFIG_MODULES
+
+static const char *lwtunnel_encap_str(enum lwtunnel_encap_types encap_type)
+{
+ /* Only lwt encaps implemented without using an interface for
+ * the encap need to return a string here.
+ */
+ switch (encap_type) {
+ case LWTUNNEL_ENCAP_MPLS:
+ return "MPLS";
+ case LWTUNNEL_ENCAP_ILA:
+ return "ILA";
+ case LWTUNNEL_ENCAP_SEG6:
+ 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:
+ case __LWTUNNEL_ENCAP_MAX:
+ /* should not have got here */
+ WARN_ON(1);
+ break;
+ }
+ return NULL;
+}
+
+#endif /* CONFIG_MODULES */
+
+struct lwtunnel_state *lwtunnel_state_alloc(int encap_len)
+{
+ struct lwtunnel_state *lws;
+
+ lws = kzalloc(sizeof(*lws) + encap_len, GFP_ATOMIC);
+
+ return lws;
+}
+EXPORT_SYMBOL_GPL(lwtunnel_state_alloc);
+
+static const struct lwtunnel_encap_ops __rcu *
+ lwtun_encaps[LWTUNNEL_ENCAP_MAX + 1] __read_mostly;
+
+int lwtunnel_encap_add_ops(const struct lwtunnel_encap_ops *ops,
+ unsigned int num)
+{
+ if (num > LWTUNNEL_ENCAP_MAX)
+ return -ERANGE;
+
+ return !cmpxchg((const struct lwtunnel_encap_ops **)
+ &lwtun_encaps[num],
+ NULL, ops) ? 0 : -1;
+}
+EXPORT_SYMBOL_GPL(lwtunnel_encap_add_ops);
+
+int lwtunnel_encap_del_ops(const struct lwtunnel_encap_ops *ops,
+ unsigned int encap_type)
+{
+ int ret;
+
+ if (encap_type == LWTUNNEL_ENCAP_NONE ||
+ encap_type > LWTUNNEL_ENCAP_MAX)
+ return -ERANGE;
+
+ ret = (cmpxchg((const struct lwtunnel_encap_ops **)
+ &lwtun_encaps[encap_type],
+ ops, NULL) == ops) ? 0 : -1;
+
+ synchronize_net();
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(lwtunnel_encap_del_ops);
+
+int lwtunnel_build_state(u16 encap_type,
+ struct nlattr *encap, unsigned int family,
+ const void *cfg, struct lwtunnel_state **lws,
+ struct netlink_ext_ack *extack)
+{
+ const struct lwtunnel_encap_ops *ops;
+ bool found = false;
+ int ret = -EINVAL;
+
+ if (encap_type == LWTUNNEL_ENCAP_NONE ||
+ encap_type > LWTUNNEL_ENCAP_MAX) {
+ NL_SET_ERR_MSG_ATTR(extack, encap,
+ "Unknown LWT encapsulation type");
+ return ret;
+ }
+
+ ret = -EOPNOTSUPP;
+ rcu_read_lock();
+ ops = rcu_dereference(lwtun_encaps[encap_type]);
+ if (likely(ops && ops->build_state && try_module_get(ops->owner))) {
+ found = true;
+ ret = ops->build_state(encap, family, cfg, lws, extack);
+ if (ret)
+ module_put(ops->owner);
+ }
+ rcu_read_unlock();
+
+ /* don't rely on -EOPNOTSUPP to detect match as build_state
+ * handlers could return it
+ */
+ if (!found) {
+ NL_SET_ERR_MSG_ATTR(extack, encap,
+ "LWT encapsulation type not supported");
+ }
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(lwtunnel_build_state);
+
+int lwtunnel_valid_encap_type(u16 encap_type, struct netlink_ext_ack *extack)
+{
+ const struct lwtunnel_encap_ops *ops;
+ int ret = -EINVAL;
+
+ if (encap_type == LWTUNNEL_ENCAP_NONE ||
+ encap_type > LWTUNNEL_ENCAP_MAX) {
+ NL_SET_ERR_MSG(extack, "Unknown lwt encapsulation type");
+ return ret;
+ }
+
+ rcu_read_lock();
+ ops = rcu_dereference(lwtun_encaps[encap_type]);
+ rcu_read_unlock();
+#ifdef CONFIG_MODULES
+ if (!ops) {
+ const char *encap_type_str = lwtunnel_encap_str(encap_type);
+
+ if (encap_type_str) {
+ __rtnl_unlock();
+ request_module("rtnl-lwt-%s", encap_type_str);
+ rtnl_lock();
+
+ rcu_read_lock();
+ ops = rcu_dereference(lwtun_encaps[encap_type]);
+ rcu_read_unlock();
+ }
+ }
+#endif
+ ret = ops ? 0 : -EOPNOTSUPP;
+ if (ret < 0)
+ NL_SET_ERR_MSG(extack, "lwt encapsulation type not supported");
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(lwtunnel_valid_encap_type);
+
+int lwtunnel_valid_encap_type_attr(struct nlattr *attr, int remaining,
+ struct netlink_ext_ack *extack)
+{
+ struct rtnexthop *rtnh = (struct rtnexthop *)attr;
+ struct nlattr *nla_entype;
+ struct nlattr *attrs;
+ u16 encap_type;
+ int attrlen;
+
+ while (rtnh_ok(rtnh, remaining)) {
+ attrlen = rtnh_attrlen(rtnh);
+ if (attrlen > 0) {
+ attrs = rtnh_attrs(rtnh);
+ nla_entype = nla_find(attrs, attrlen, RTA_ENCAP_TYPE);
+
+ if (nla_entype) {
+ encap_type = nla_get_u16(nla_entype);
+
+ if (lwtunnel_valid_encap_type(encap_type,
+ extack) != 0)
+ return -EOPNOTSUPP;
+ }
+ }
+ rtnh = rtnh_next(rtnh, &remaining);
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(lwtunnel_valid_encap_type_attr);
+
+void lwtstate_free(struct lwtunnel_state *lws)
+{
+ const struct lwtunnel_encap_ops *ops = lwtun_encaps[lws->type];
+
+ if (ops->destroy_state) {
+ ops->destroy_state(lws);
+ kfree_rcu(lws, rcu);
+ } else {
+ kfree(lws);
+ }
+ module_put(ops->owner);
+}
+EXPORT_SYMBOL_GPL(lwtstate_free);
+
+int lwtunnel_fill_encap(struct sk_buff *skb, struct lwtunnel_state *lwtstate)
+{
+ const struct lwtunnel_encap_ops *ops;
+ struct nlattr *nest;
+ int ret;
+
+ if (!lwtstate)
+ return 0;
+
+ if (lwtstate->type == LWTUNNEL_ENCAP_NONE ||
+ lwtstate->type > LWTUNNEL_ENCAP_MAX)
+ return 0;
+
+ nest = nla_nest_start(skb, RTA_ENCAP);
+ if (!nest)
+ return -EMSGSIZE;
+
+ ret = -EOPNOTSUPP;
+ rcu_read_lock();
+ ops = rcu_dereference(lwtun_encaps[lwtstate->type]);
+ if (likely(ops && ops->fill_encap))
+ ret = ops->fill_encap(skb, lwtstate);
+ rcu_read_unlock();
+
+ if (ret)
+ goto nla_put_failure;
+ nla_nest_end(skb, nest);
+ ret = nla_put_u16(skb, RTA_ENCAP_TYPE, lwtstate->type);
+ if (ret)
+ goto nla_put_failure;
+
+ return 0;
+
+nla_put_failure:
+ nla_nest_cancel(skb, nest);
+
+ return (ret == -EOPNOTSUPP ? 0 : ret);
+}
+EXPORT_SYMBOL_GPL(lwtunnel_fill_encap);
+
+int lwtunnel_get_encap_size(struct lwtunnel_state *lwtstate)
+{
+ const struct lwtunnel_encap_ops *ops;
+ int ret = 0;
+
+ if (!lwtstate)
+ return 0;
+
+ if (lwtstate->type == LWTUNNEL_ENCAP_NONE ||
+ lwtstate->type > LWTUNNEL_ENCAP_MAX)
+ return 0;
+
+ rcu_read_lock();
+ ops = rcu_dereference(lwtun_encaps[lwtstate->type]);
+ if (likely(ops && ops->get_encap_size))
+ ret = nla_total_size(ops->get_encap_size(lwtstate));
+ rcu_read_unlock();
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(lwtunnel_get_encap_size);
+
+int lwtunnel_cmp_encap(struct lwtunnel_state *a, struct lwtunnel_state *b)
+{
+ const struct lwtunnel_encap_ops *ops;
+ int ret = 0;
+
+ if (!a && !b)
+ return 0;
+
+ if (!a || !b)
+ return 1;
+
+ if (a->type != b->type)
+ return 1;
+
+ if (a->type == LWTUNNEL_ENCAP_NONE ||
+ a->type > LWTUNNEL_ENCAP_MAX)
+ return 0;
+
+ rcu_read_lock();
+ ops = rcu_dereference(lwtun_encaps[a->type]);
+ if (likely(ops && ops->cmp_encap))
+ ret = ops->cmp_encap(a, b);
+ rcu_read_unlock();
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(lwtunnel_cmp_encap);
+
+int lwtunnel_output(struct net *net, struct sock *sk, struct sk_buff *skb)
+{
+ struct dst_entry *dst = skb_dst(skb);
+ const struct lwtunnel_encap_ops *ops;
+ struct lwtunnel_state *lwtstate;
+ int ret = -EINVAL;
+
+ if (!dst)
+ goto drop;
+ lwtstate = dst->lwtstate;
+
+ if (lwtstate->type == LWTUNNEL_ENCAP_NONE ||
+ lwtstate->type > LWTUNNEL_ENCAP_MAX)
+ return 0;
+
+ ret = -EOPNOTSUPP;
+ rcu_read_lock();
+ ops = rcu_dereference(lwtun_encaps[lwtstate->type]);
+ if (likely(ops && ops->output))
+ ret = ops->output(net, sk, skb);
+ rcu_read_unlock();
+
+ if (ret == -EOPNOTSUPP)
+ goto drop;
+
+ return ret;
+
+drop:
+ kfree_skb(skb);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(lwtunnel_output);
+
+int lwtunnel_xmit(struct sk_buff *skb)
+{
+ struct dst_entry *dst = skb_dst(skb);
+ const struct lwtunnel_encap_ops *ops;
+ struct lwtunnel_state *lwtstate;
+ int ret = -EINVAL;
+
+ if (!dst)
+ goto drop;
+
+ lwtstate = dst->lwtstate;
+
+ if (lwtstate->type == LWTUNNEL_ENCAP_NONE ||
+ lwtstate->type > LWTUNNEL_ENCAP_MAX)
+ return 0;
+
+ ret = -EOPNOTSUPP;
+ rcu_read_lock();
+ ops = rcu_dereference(lwtun_encaps[lwtstate->type]);
+ if (likely(ops && ops->xmit))
+ ret = ops->xmit(skb);
+ rcu_read_unlock();
+
+ if (ret == -EOPNOTSUPP)
+ goto drop;
+
+ return ret;
+
+drop:
+ kfree_skb(skb);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(lwtunnel_xmit);
+
+int lwtunnel_input(struct sk_buff *skb)
+{
+ struct dst_entry *dst = skb_dst(skb);
+ const struct lwtunnel_encap_ops *ops;
+ struct lwtunnel_state *lwtstate;
+ int ret = -EINVAL;
+
+ if (!dst)
+ goto drop;
+ lwtstate = dst->lwtstate;
+
+ if (lwtstate->type == LWTUNNEL_ENCAP_NONE ||
+ lwtstate->type > LWTUNNEL_ENCAP_MAX)
+ return 0;
+
+ ret = -EOPNOTSUPP;
+ rcu_read_lock();
+ ops = rcu_dereference(lwtun_encaps[lwtstate->type]);
+ if (likely(ops && ops->input))
+ ret = ops->input(skb);
+ rcu_read_unlock();
+
+ if (ret == -EOPNOTSUPP)
+ goto drop;
+
+ return ret;
+
+drop:
+ kfree_skb(skb);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(lwtunnel_input);
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-24 11:08:47 +0000