neighbour: register rtnl doit handler

this patch registers neigh doit handler. The doit handler
returns a neigh entry given dst and dev. This is similar
to route and fdb doit (get) handlers. Also moves nda_policy
declaration from rtnetlink.c to neighbour.c

Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Reviewed-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/neighbour.h b/include/net/neighbour.h
index 66221f1991c07416c9a81470e7c1bb3807f793db..7c1ab9edba03873ffc9ea029e7925e12051f6b02 100644 (file)
--- a/include/net/neighbour.h
+++ b/include/net/neighbour.h
@@ -255,6 +255,7 @@ static inline void *neighbour_priv(const struct neighbour *n)
 #define NEIGH_UPDATE_F_ISROUTER                        0x40000000
 #define NEIGH_UPDATE_F_ADMIN                   0x80000000
 
+extern const struct nla_policy nda_policy[];
 
 static inline bool neigh_key_eq16(const struct neighbour *n, const void *pkey)
 {

diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index fb4372cb1de1f2fdabdb2cfb9a8b2305234c939b..43687c9abe1dfae19bbe05d4f21f8a05a4960104 100644 (file)
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -1751,6 +1751,18 @@ static struct neigh_table *neigh_find_table(int family)
        return tbl;
 }
 
+const struct nla_policy nda_policy[NDA_MAX+1] = {
+       [NDA_DST]               = { .type = NLA_BINARY, .len = MAX_ADDR_LEN },
+       [NDA_LLADDR]            = { .type = NLA_BINARY, .len = MAX_ADDR_LEN },
+       [NDA_CACHEINFO]         = { .len = sizeof(struct nda_cacheinfo) },
+       [NDA_PROBES]            = { .type = NLA_U32 },
+       [NDA_VLAN]              = { .type = NLA_U16 },
+       [NDA_PORT]              = { .type = NLA_U16 },
+       [NDA_VNI]               = { .type = NLA_U32 },
+       [NDA_IFINDEX]           = { .type = NLA_U32 },
+       [NDA_MASTER]            = { .type = NLA_U32 },
+};
+
 static int neigh_delete(struct sk_buff *skb, struct nlmsghdr *nlh,
                        struct netlink_ext_ack *extack)
 {
@@ -2711,6 +2723,186 @@ static int neigh_dump_info(struct sk_buff *skb, struct netlink_callback *cb)
        return skb->len;
 }
 
+static int neigh_valid_get_req(const struct nlmsghdr *nlh,
+                              struct neigh_table **tbl,
+                              void **dst, int *dev_idx, u8 *ndm_flags,
+                              struct netlink_ext_ack *extack)
+{
+       struct nlattr *tb[NDA_MAX + 1];
+       struct ndmsg *ndm;
+       int err, i;
+
+       if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*ndm))) {
+               NL_SET_ERR_MSG(extack, "Invalid header for neighbor get request");
+               return -EINVAL;
+       }
+
+       ndm = nlmsg_data(nlh);
+       if (ndm->ndm_pad1  || ndm->ndm_pad2  || ndm->ndm_state ||
+           ndm->ndm_type) {
+               NL_SET_ERR_MSG(extack, "Invalid values in header for neighbor get request");
+               return -EINVAL;
+       }
+
+       if (ndm->ndm_flags & ~NTF_PROXY) {
+               NL_SET_ERR_MSG(extack, "Invalid flags in header for neighbor get request");
+               return -EINVAL;
+       }
+
+       err = nlmsg_parse_strict(nlh, sizeof(struct ndmsg), tb, NDA_MAX,
+                                nda_policy, extack);
+       if (err < 0)
+               return err;
+
+       *ndm_flags = ndm->ndm_flags;
+       *dev_idx = ndm->ndm_ifindex;
+       *tbl = neigh_find_table(ndm->ndm_family);
+       if (*tbl == NULL) {
+               NL_SET_ERR_MSG(extack, "Unsupported family in header for neighbor get request");
+               return -EAFNOSUPPORT;
+       }
+
+       for (i = 0; i <= NDA_MAX; ++i) {
+               if (!tb[i])
+                       continue;
+
+               switch (i) {
+               case NDA_DST:
+                       if (nla_len(tb[i]) != (int)(*tbl)->key_len) {
+                               NL_SET_ERR_MSG(extack, "Invalid network address in neighbor get request");
+                               return -EINVAL;
+                       }
+                       *dst = nla_data(tb[i]);
+                       break;
+               default:
+                       NL_SET_ERR_MSG(extack, "Unsupported attribute in neighbor get request");
+                       return -EINVAL;
+               }
+       }
+
+       return 0;
+}
+
+static inline size_t neigh_nlmsg_size(void)
+{
+       return NLMSG_ALIGN(sizeof(struct ndmsg))
+              + nla_total_size(MAX_ADDR_LEN) /* NDA_DST */
+              + nla_total_size(MAX_ADDR_LEN) /* NDA_LLADDR */
+              + nla_total_size(sizeof(struct nda_cacheinfo))
+              + nla_total_size(4)  /* NDA_PROBES */
+              + nla_total_size(1); /* NDA_PROTOCOL */
+}
+
+static int neigh_get_reply(struct net *net, struct neighbour *neigh,
+                          u32 pid, u32 seq)
+{
+       struct sk_buff *skb;
+       int err = 0;
+
+       skb = nlmsg_new(neigh_nlmsg_size(), GFP_KERNEL);
+       if (!skb)
+               return -ENOBUFS;
+
+       err = neigh_fill_info(skb, neigh, pid, seq, RTM_NEWNEIGH, 0);
+       if (err) {
+               kfree_skb(skb);
+               goto errout;
+       }
+
+       err = rtnl_unicast(skb, net, pid);
+errout:
+       return err;
+}
+
+static inline size_t pneigh_nlmsg_size(void)
+{
+       return NLMSG_ALIGN(sizeof(struct ndmsg))
+              + nla_total_size(MAX_ADDR_LEN); /* NDA_DST */
+              + nla_total_size(1); /* NDA_PROTOCOL */
+}
+
+static int pneigh_get_reply(struct net *net, struct pneigh_entry *neigh,
+                           u32 pid, u32 seq, struct neigh_table *tbl)
+{
+       struct sk_buff *skb;
+       int err = 0;
+
+       skb = nlmsg_new(pneigh_nlmsg_size(), GFP_KERNEL);
+       if (!skb)
+               return -ENOBUFS;
+
+       err = pneigh_fill_info(skb, neigh, pid, seq, RTM_NEWNEIGH, 0, tbl);
+       if (err) {
+               kfree_skb(skb);
+               goto errout;
+       }
+
+       err = rtnl_unicast(skb, net, pid);
+errout:
+       return err;
+}
+
+static int neigh_get(struct sk_buff *in_skb, struct nlmsghdr *nlh,
+                    struct netlink_ext_ack *extack)
+{
+       struct net *net = sock_net(in_skb->sk);
+       struct net_device *dev = NULL;
+       struct neigh_table *tbl = NULL;
+       struct neighbour *neigh;
+       void *dst = NULL;
+       u8 ndm_flags = 0;
+       int dev_idx = 0;
+       int err;
+
+       err = neigh_valid_get_req(nlh, &tbl, &dst, &dev_idx, &ndm_flags,
+                                 extack);
+       if (err < 0)
+               return err;
+
+       if (dev_idx) {
+               dev = __dev_get_by_index(net, dev_idx);
+               if (!dev) {
+                       NL_SET_ERR_MSG(extack, "Unknown device ifindex");
+                       return -ENODEV;
+               }
+       }
+
+       if (!dst) {
+               NL_SET_ERR_MSG(extack, "Network address not specified");
+               return -EINVAL;
+       }
+
+       if (ndm_flags & NTF_PROXY) {
+               struct pneigh_entry *pn;
+
+               pn = pneigh_lookup(tbl, net, dst, dev, 0);
+               if (!pn) {
+                       NL_SET_ERR_MSG(extack, "Proxy neighbour entry not found");
+                       return -ENOENT;
+               }
+               return pneigh_get_reply(net, pn, NETLINK_CB(in_skb).portid,
+                                       nlh->nlmsg_seq, tbl);
+       }
+
+       if (!dev) {
+               NL_SET_ERR_MSG(extack, "No device specified");
+               return -EINVAL;
+       }
+
+       neigh = neigh_lookup(tbl, dst, dev);
+       if (!neigh) {
+               NL_SET_ERR_MSG(extack, "Neighbour entry not found");
+               return -ENOENT;
+       }
+
+       err = neigh_get_reply(net, neigh, NETLINK_CB(in_skb).portid,
+                             nlh->nlmsg_seq);
+
+       neigh_release(neigh);
+
+       return err;
+}
+
 void neigh_for_each(struct neigh_table *tbl, void (*cb)(struct neighbour *, void *), void *cookie)
 {
        int chain;
@@ -3118,16 +3310,6 @@ static const struct seq_operations neigh_stat_seq_ops = {
 };
 #endif /* CONFIG_PROC_FS */
 
-static inline size_t neigh_nlmsg_size(void)
-{
-       return NLMSG_ALIGN(sizeof(struct ndmsg))
-              + nla_total_size(MAX_ADDR_LEN) /* NDA_DST */
-              + nla_total_size(MAX_ADDR_LEN) /* NDA_LLADDR */
-              + nla_total_size(sizeof(struct nda_cacheinfo))
-              + nla_total_size(4)  /* NDA_PROBES */
-              + nla_total_size(1); /* NDA_PROTOCOL */
-}
-
 static void __neigh_notify(struct neighbour *n, int type, int flags,
                           u32 pid)
 {
@@ -3511,7 +3693,7 @@ static int __init neigh_init(void)
 {
        rtnl_register(PF_UNSPEC, RTM_NEWNEIGH, neigh_add, NULL, 0);
        rtnl_register(PF_UNSPEC, RTM_DELNEIGH, neigh_delete, NULL, 0);
-       rtnl_register(PF_UNSPEC, RTM_GETNEIGH, NULL, neigh_dump_info, 0);
+       rtnl_register(PF_UNSPEC, RTM_GETNEIGH, neigh_get, neigh_dump_info, 0);
 
        rtnl_register(PF_UNSPEC, RTM_GETNEIGHTBL, NULL, neightbl_dump_info,
                      0);

diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index baf2685b4da2de9e45e5a86f34ac35a6603017ae..48f61885fd6f9feb2ff9afeff78d03e98e97afd4 100644 (file)
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -3460,18 +3460,6 @@ void rtmsg_ifinfo_newnet(int type, struct net_device *dev, unsigned int change,
                           new_nsid, new_ifindex);
 }
 
-static const struct nla_policy nda_policy[NDA_MAX+1] = {
-       [NDA_DST]               = { .type = NLA_BINARY, .len = MAX_ADDR_LEN },
-       [NDA_LLADDR]            = { .type = NLA_BINARY, .len = MAX_ADDR_LEN },
-       [NDA_CACHEINFO]         = { .len = sizeof(struct nda_cacheinfo) },
-       [NDA_PROBES]            = { .type = NLA_U32 },
-       [NDA_VLAN]              = { .type = NLA_U16 },
-       [NDA_PORT]              = { .type = NLA_U16 },
-       [NDA_VNI]               = { .type = NLA_U32 },
-       [NDA_IFINDEX]           = { .type = NLA_U32 },
-       [NDA_MASTER]            = { .type = NLA_U32 },
-};
-
 static int nlmsg_populate_fdb_fill(struct sk_buff *skb,
                                   struct net_device *dev,
                                   u8 *addr, u16 vid, u32 pid, u32 seq,