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/include/linux/seg6_genl.h b/include/linux/seg6_genl.h
new file mode 100644 (file)
index 0000000..d6c3fb4
--- /dev/null
+++ b/include/linux/seg6_genl.h
@@ -0,0 +1,6 @@
+#ifndef _LINUX_SEG6_GENL_H
+#define _LINUX_SEG6_GENL_H
+
+#include <uapi/linux/seg6_genl.h>
+
+#endif

diff --git a/include/net/netns/ipv6.h b/include/net/netns/ipv6.h
index 10d0848f5b8aa85b47803506f7a70c2dcd5c1364..de7745e2edcc63e65c1ab224a6835367d55c54c4 100644 (file)
--- a/include/net/netns/ipv6.h
+++ b/include/net/netns/ipv6.h
@@ -85,6 +85,7 @@ struct netns_ipv6 {
 #endif
        atomic_t                dev_addr_genid;
        atomic_t                fib6_sernum;
+       struct seg6_pernet_data *seg6_data;
 };
 
 #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6)

diff --git a/include/net/seg6.h b/include/net/seg6.h
index 4dd52a7e95f1ead8d1d97f1903f6e103a13da3fd..7c7b8ed39661a02ce14fdf12b88100cecae20686 100644 (file)
--- a/include/net/seg6.h
+++ b/include/net/seg6.h
@@ -14,6 +14,9 @@
 #ifndef _NET_SEG6_H
 #define _NET_SEG6_H
 
+#include <linux/net.h>
+#include <linux/ipv6.h>
+
 static inline void update_csum_diff4(struct sk_buff *skb, __be32 from,
                                     __be32 to)
 {
@@ -33,4 +36,17 @@ static inline void update_csum_diff16(struct sk_buff *skb, __be32 *from,
        skb->csum = ~csum_partial((char *)diff, sizeof(diff), ~skb->csum);
 }
 
+struct seg6_pernet_data {
+       struct mutex lock;
+       struct in6_addr __rcu *tun_src;
+};
+
+static inline struct seg6_pernet_data *seg6_pernet(struct net *net)
+{
+       return net->ipv6.seg6_data;
+}
+
+extern int seg6_init(void);
+extern void seg6_exit(void);
+
 #endif

diff --git a/include/uapi/linux/seg6_genl.h b/include/uapi/linux/seg6_genl.h
new file mode 100644 (file)
index 0000000..fcf1c60
--- /dev/null
+++ b/include/uapi/linux/seg6_genl.h
@@ -0,0 +1,32 @@
+#ifndef _UAPI_LINUX_SEG6_GENL_H
+#define _UAPI_LINUX_SEG6_GENL_H
+
+#define SEG6_GENL_NAME         "SEG6"
+#define SEG6_GENL_VERSION      0x1
+
+enum {
+       SEG6_ATTR_UNSPEC,
+       SEG6_ATTR_DST,
+       SEG6_ATTR_DSTLEN,
+       SEG6_ATTR_HMACKEYID,
+       SEG6_ATTR_SECRET,
+       SEG6_ATTR_SECRETLEN,
+       SEG6_ATTR_ALGID,
+       SEG6_ATTR_HMACINFO,
+       __SEG6_ATTR_MAX,
+};
+
+#define SEG6_ATTR_MAX (__SEG6_ATTR_MAX - 1)
+
+enum {
+       SEG6_CMD_UNSPEC,
+       SEG6_CMD_SETHMAC,
+       SEG6_CMD_DUMPHMAC,
+       SEG6_CMD_SET_TUNSRC,
+       SEG6_CMD_GET_TUNSRC,
+       __SEG6_CMD_MAX,
+};
+
+#define SEG6_CMD_MAX (__SEG6_CMD_MAX - 1)
+
+#endif

diff --git a/net/ipv6/Makefile b/net/ipv6/Makefile
index c174ccb340a15bca6e712932ae5e7a9c34739efb..c92010d62afcd59c115bce2e429aed79ae831d80 100644 (file)
--- a/net/ipv6/Makefile
+++ b/net/ipv6/Makefile
@@ -9,7 +9,7 @@ ipv6-objs :=    af_inet6.o anycast.o ip6_output.o ip6_input.o addrconf.o \
                route.o ip6_fib.o ipv6_sockglue.o ndisc.o udp.o udplite.o \
                raw.o icmp.o mcast.o reassembly.o tcp_ipv6.o ping.o \
                exthdrs.o datagram.o ip6_flowlabel.o inet6_connection_sock.o \
-               udp_offload.o
+               udp_offload.o seg6.o
 
 ipv6-offload :=        ip6_offload.o tcpv6_offload.o exthdrs_offload.o
 

diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c
index c86911b63f8a30b554c7bd3932c1c307cb2fb6a3..d424f3a3737af3ffcfed52535379a6fbf61ec4c7 100644 (file)
--- a/net/ipv6/af_inet6.c
+++ b/net/ipv6/af_inet6.c
@@ -61,6 +61,7 @@
 #include <net/ip6_tunnel.h>
 #endif
 #include <net/calipso.h>
+#include <net/seg6.h>
 
 #include <asm/uaccess.h>
 #include <linux/mroute6.h>
@@ -991,6 +992,10 @@ static int __init inet6_init(void)
        if (err)
                goto calipso_fail;
 
+       err = seg6_init();
+       if (err)
+               goto seg6_fail;
+
 #ifdef CONFIG_SYSCTL
        err = ipv6_sysctl_register();
        if (err)
@@ -1001,8 +1006,10 @@ out:
 
 #ifdef CONFIG_SYSCTL
 sysctl_fail:
-       calipso_exit();
+       seg6_exit();
 #endif
+seg6_fail:
+       calipso_exit();
 calipso_fail:
        pingv6_exit();
 pingv6_fail:

diff --git a/net/ipv6/seg6.c b/net/ipv6/seg6.c
new file mode 100644 (file)
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);
+}