ipv6: sr: add code base for control plane support of SR-IPv6
This patch adds the necessary hooks and structures to provide support
for SR-IPv6 control plane, essentially the Generic Netlink commands
that will be used for userspace control over the Segment Routing
kernel structures.
The genetlink commands provide control over two different structures:
tunnel source and HMAC data. The tunnel source is the source address
that will be used by default when encapsulating packets into an
outer IPv6 header + SRH. If the tunnel source is set to :: then an
address of the outgoing interface will be selected as the source.
The HMAC commands currently just return ENOTSUPP and will be implemented
in a future patch.
Signed-off-by: David Lebrun <david.lebrun@uclouvain.be>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/seg6.c b/net/ipv6/seg6.c
new file mode 100644
index 0000000..e246b0b
--- /dev/null
+++ b/net/ipv6/seg6.c
@@ -0,0 +1,214 @@
+/*
+ * 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/errno.h>
+#include <linux/types.h>
+#include <linux/socket.h>
+#include <linux/net.h>
+#include <linux/in6.h>
+#include <linux/slab.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>
+
+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, },
+};
+
+static int seg6_genl_sethmac(struct sk_buff *skb, struct genl_info *info)
+{
+ return -ENOTSUPP;
+}
+
+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);
+
+ 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);
+ genlmsg_reply(msg, info);
+
+ return 0;
+
+nla_put_failure:
+ rcu_read_unlock();
+ genlmsg_cancel(msg, hdr);
+free_msg:
+ nlmsg_free(msg);
+ return -ENOMEM;
+}
+
+static int seg6_genl_dumphmac(struct sk_buff *skb, struct netlink_callback *cb)
+{
+ return -ENOTSUPP;
+}
+
+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;
+
+ return 0;
+}
+
+static void __net_exit seg6_net_exit(struct net *net)
+{
+ struct seg6_pernet_data *sdata = seg6_pernet(net);
+
+ 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,
+ .doit = seg6_genl_sethmac,
+ .policy = seg6_genl_policy,
+ .flags = GENL_ADMIN_PERM,
+ },
+ {
+ .cmd = SEG6_CMD_DUMPHMAC,
+ .dumpit = seg6_genl_dumphmac,
+ .policy = seg6_genl_policy,
+ .flags = GENL_ADMIN_PERM,
+ },
+ {
+ .cmd = SEG6_CMD_SET_TUNSRC,
+ .doit = seg6_genl_set_tunsrc,
+ .policy = seg6_genl_policy,
+ .flags = GENL_ADMIN_PERM,
+ },
+ {
+ .cmd = SEG6_CMD_GET_TUNSRC,
+ .doit = seg6_genl_get_tunsrc,
+ .policy = seg6_genl_policy,
+ .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,
+ .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 = -ENOMEM;
+
+ err = genl_register_family(&seg6_genl_family);
+ if (err)
+ goto out;
+
+ err = register_pernet_subsys(&ip6_segments_ops);
+ if (err)
+ goto out_unregister_genl;
+
+ pr_info("Segment Routing with IPv6\n");
+
+out:
+ return err;
+out_unregister_genl:
+ genl_unregister_family(&seg6_genl_family);
+ goto out;
+}
+
+void seg6_exit(void)
+{
+ unregister_pernet_subsys(&ip6_segments_ops);
+ genl_unregister_family(&seg6_genl_family);
+}