fou: implement FOU_CMD_GET

Cc: Tom Herbert <tom@herbertland.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 110 insertions, 0 deletions

diff --git a/include/uapi/linux/fou.h b/include/uapi/linux/fou.h
index c303588bb767..d2947c52dc67 100644
--- a/include/uapi/linux/fou.h
+++ b/include/uapi/linux/fou.h
@@ -25,6 +25,7 @@ enum {
         FOU_CMD_UNSPEC,
         FOU_CMD_ADD,
         FOU_CMD_DEL,
+        FOU_CMD_GET,
 
         __FOU_CMD_MAX,
 };
diff --git a/net/ipv4/fou.c b/net/ipv4/fou.c
index c244b1a65787..263710259774 100644
--- a/net/ipv4/fou.c
+++ b/net/ipv4/fou.c
@@ -21,6 +21,7 @@ struct fou {
         u8 protocol;
         u8 flags;
         __be16 port;
+        u16 type;
         struct udp_offload udp_offloads;
         struct list_head list;
 };
@@ -487,6 +488,8 @@ static int fou_create(struct net *net, struct fou_cfg *cfg,
                 goto error;
         }
 
+        fou->type = cfg->type;
+
         udp_sk(sk)->encap_type = 1;
         udp_encap_enable();
 
@@ -617,6 +620,106 @@ static int fou_nl_cmd_rm_port(struct sk_buff *skb, struct genl_info *info)
         return fou_destroy(net, &cfg);
 }
 
+static int fou_fill_info(struct fou *fou, struct sk_buff *msg)
+{
+        if (nla_put_u8(msg, FOU_ATTR_AF, fou->sock->sk->sk_family) ||
+            nla_put_be16(msg, FOU_ATTR_PORT, fou->port) ||
+            nla_put_u8(msg, FOU_ATTR_IPPROTO, fou->protocol) ||
+            nla_put_u8(msg, FOU_ATTR_TYPE, fou->type))
+                return -1;
+
+        if (fou->flags & FOU_F_REMCSUM_NOPARTIAL)
+                if (nla_put_flag(msg, FOU_ATTR_REMCSUM_NOPARTIAL))
+                        return -1;
+        return 0;
+}
+
+static int fou_dump_info(struct fou *fou, u32 portid, u32 seq,
+                         u32 flags, struct sk_buff *skb, u8 cmd)
+{
+        void *hdr;
+
+        hdr = genlmsg_put(skb, portid, seq, &fou_nl_family, flags, cmd);
+        if (!hdr)
+                return -ENOMEM;
+
+        if (fou_fill_info(fou, skb) < 0)
+                goto nla_put_failure;
+
+        genlmsg_end(skb, hdr);
+        return 0;
+
+nla_put_failure:
+        genlmsg_cancel(skb, hdr);
+        return -EMSGSIZE;
+}
+
+static int fou_nl_cmd_get_port(struct sk_buff *skb, struct genl_info *info)
+{
+        struct net *net = genl_info_net(info);
+        struct fou_net *fn = net_generic(net, fou_net_id);
+        struct sk_buff *msg;
+        struct fou_cfg cfg;
+        struct fou *fout;
+        __be16 port;
+        int ret;
+
+        ret = parse_nl_config(info, &cfg);
+        if (ret)
+                return ret;
+        port = cfg.udp_config.local_udp_port;
+        if (port == 0)
+                return -EINVAL;
+
+        msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
+        if (!msg)
+                return -ENOMEM;
+
+        ret = -ESRCH;
+        mutex_lock(&fn->fou_lock);
+        list_for_each_entry(fout, &fn->fou_list, list) {
+                if (port == fout->port) {
+                        ret = fou_dump_info(fout, info->snd_portid,
+                                            info->snd_seq, 0, msg,
+                                            info->genlhdr->cmd);
+                        break;
+                }
+        }
+        mutex_unlock(&fn->fou_lock);
+        if (ret < 0)
+                goto out_free;
+
+        return genlmsg_reply(msg, info);
+
+out_free:
+        nlmsg_free(msg);
+        return ret;
+}
+
+static int fou_nl_dump(struct sk_buff *skb, struct netlink_callback *cb)
+{
+        struct net *net = sock_net(skb->sk);
+        struct fou_net *fn = net_generic(net, fou_net_id);
+        struct fou *fout;
+        int idx = 0, ret;
+
+        mutex_lock(&fn->fou_lock);
+        list_for_each_entry(fout, &fn->fou_list, list) {
+                if (idx++ < cb->args[0])
+                        continue;
+                ret = fou_dump_info(fout, NETLINK_CB(cb->skb).portid,
+                                    cb->nlh->nlmsg_seq, NLM_F_MULTI,
+                                    skb, FOU_CMD_GET);
+                if (ret)
+                        goto done;
+        }
+        mutex_unlock(&fn->fou_lock);
+
+done:
+        cb->args[0] = idx;
+        return skb->len;
+}
+
 static const struct genl_ops fou_nl_ops[] = {
         {
                 .cmd = FOU_CMD_ADD,
@@ -630,6 +733,12 @@ static const struct genl_ops fou_nl_ops[] = {
                 .policy = fou_nl_policy,
                 .flags = GENL_ADMIN_PERM,
         },
+        {
+                .cmd = FOU_CMD_GET,
+                .doit = fou_nl_cmd_get_port,
+                .dumpit = fou_nl_dump,
+                .policy = fou_nl_policy,
+        },
 };
 
 size_t fou_encap_hlen(struct ip_tunnel_encap *e)