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neighbour: register rtnl doit handler
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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 <[email protected]>
Reviewed-by: David Ahern <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
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@roopa-prabhu @davem330
roopa-prabhu authored and davem330 committed Dec 19, 2018
1 parent 4ab0ede commit 82cbb5c
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Showing 3 changed files with 194 additions and 23 deletions.
1 change: 1 addition & 0 deletions include/net/neighbour.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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)
{
Expand Down
204 changes: 193 additions & 11 deletions net/core/neighbour.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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)
{
Expand Down Expand Up @@ -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;
Expand Down Expand Up @@ -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)
{
Expand Down Expand Up @@ -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);
Expand Down
12 changes: 0 additions & 12 deletions net/core/rtnetlink.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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,
Expand Down

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