ipv6: sr: implement API to control SR HMAC structure

This patch provides an implementation of the genetlink commands
to associate a given HMAC key identifier with an hashing algorithm
and a secret.

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
index 9c78053e67e05ddb2baefe7143be0c56dcbdae6a..50f6e0663d1db3cac7fcf024be9b4cd29ff865d1 100644 (file)
--- a/net/ipv6/seg6.c
+++ b/net/ipv6/seg6.c
@@ -25,6 +25,9 @@
 #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)
 {
@@ -76,11 +79,90 @@ static const struct nla_policy seg6_genl_policy[SEG6_ATTR_MAX + 1] = {
        [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 (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);
@@ -145,11 +227,135 @@ 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 net *net = sock_net(skb->sk);
+       struct seg6_pernet_data *sdata;
+       struct seg6_hmac_info *hinfo;
+       int ret;
+
+       sdata = seg6_pernet(net);
+
+       ret = rhashtable_walk_start(iter);
+       if (ret && ret != -EAGAIN)
+               goto done;
+
+       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;
@@ -168,6 +374,10 @@ static int __net_init seg6_net_init(struct net *net)
 
        net->ipv6.seg6_data = sdata;
 
+#ifdef CONFIG_IPV6_SEG6_HMAC
+       seg6_hmac_net_init(net);
+#endif
+
        return 0;
 }
 
@@ -175,6 +385,10 @@ 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);
 }
@@ -193,7 +407,9 @@ static const struct genl_ops seg6_genl_ops[] = {
        },
        {
                .cmd    = SEG6_CMD_DUMPHMAC,
+               .start  = seg6_genl_dumphmac_start,
                .dumpit = seg6_genl_dumphmac,
+               .done   = seg6_genl_dumphmac_done,
                .policy = seg6_genl_policy,
                .flags  = GENL_ADMIN_PERM,
        },
@@ -239,10 +455,20 @@ int __init seg6_init(void)
        if (err)
                goto out_unregister_pernet;
 
+#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:
+       seg6_iptunnel_exit();
+#endif
 out_unregister_pernet:
        unregister_pernet_subsys(&ip6_segments_ops);
 out_unregister_genl:
@@ -252,6 +478,9 @@ out_unregister_genl:
 
 void seg6_exit(void)
 {
+#ifdef CONFIG_IPV6_SEG6_HMAC
+       seg6_hmac_exit();
+#endif
        seg6_iptunnel_exit();
        unregister_pernet_subsys(&ip6_segments_ops);
        genl_unregister_family(&seg6_genl_family);