Commit eaaa3139 authored by Andrey Vagin's avatar Andrey Vagin Committed by David S. Miller

netlink: Diag core and basic socket info dumping (v2)

The netlink_diag can be built as a module, just like it's done in
unix sockets.

The core dumping message carries the basic info about netlink sockets:
family, type and protocol, portis, dst_group, dst_portid, state.

Groups can be received as an optional parameter NETLINK_DIAG_GROUPS.

Netlink sockets cab be filtered by protocols.

The socket inode number and cookie is reserved for future per-socket info
retrieving. The per-protocol filtering is also reserved for future by
requiring the sdiag_protocol to be zero.

The file /proc/net/netlink doesn't provide enough information for
dumping netlink sockets. It doesn't provide dst_group, dst_portid,
groups above 32.

v2: fix NETLINK_DIAG_MAX. Now it's equal to the last constant.
Acked-by: default avatarPavel Emelyanov <xemul@parallels.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Pablo Neira Ayuso <pablo@netfilter.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Gao feng <gaofeng@cn.fujitsu.com>
Cc: Thomas Graf <tgraf@suug.ch>
Signed-off-by: default avatarAndrey Vagin <avagin@openvz.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 0f29c768
#ifndef __NETLINK_DIAG_H__
#define __NETLINK_DIAG_H__
#include <linux/types.h>
struct netlink_diag_req {
__u8 sdiag_family;
__u8 sdiag_protocol;
__u16 pad;
__u32 ndiag_ino;
__u32 ndiag_show;
__u32 ndiag_cookie[2];
};
struct netlink_diag_msg {
__u8 ndiag_family;
__u8 ndiag_type;
__u8 ndiag_protocol;
__u8 ndiag_state;
__u32 ndiag_portid;
__u32 ndiag_dst_portid;
__u32 ndiag_dst_group;
__u32 ndiag_ino;
__u32 ndiag_cookie[2];
};
enum {
NETLINK_DIAG_MEMINFO,
NETLINK_DIAG_GROUPS,
__NETLINK_DIAG_MAX,
};
#define NETLINK_DIAG_MAX (__NETLINK_DIAG_MAX - 1)
#define NDIAG_PROTO_ALL ((__u8) ~0)
#define NDIAG_SHOW_MEMINFO 0x00000001 /* show memory info of a socket */
#define NDIAG_SHOW_GROUPS 0x00000002 /* show groups of a netlink socket */
#endif
......@@ -217,6 +217,7 @@ source "net/dns_resolver/Kconfig"
source "net/batman-adv/Kconfig"
source "net/openvswitch/Kconfig"
source "net/vmw_vsock/Kconfig"
source "net/netlink/Kconfig"
config RPS
boolean
......
#
# Netlink Sockets
#
config NETLINK_DIAG
tristate "NETLINK: socket monitoring interface"
default n
---help---
Support for NETLINK socket monitoring interface used by the ss tool.
If unsure, say Y.
......@@ -3,3 +3,6 @@
#
obj-y := af_netlink.o genetlink.o
obj-$(CONFIG_NETLINK_DIAG) += netlink_diag.o
netlink_diag-y := diag.o
#include <linux/module.h>
#include <net/sock.h>
#include <linux/netlink.h>
#include <linux/sock_diag.h>
#include <linux/netlink_diag.h>
#include "af_netlink.h"
static int sk_diag_dump_groups(struct sock *sk, struct sk_buff *nlskb)
{
struct netlink_sock *nlk = nlk_sk(sk);
if (nlk->groups == NULL)
return 0;
return nla_put(nlskb, NETLINK_DIAG_GROUPS, NLGRPSZ(nlk->ngroups),
nlk->groups);
}
static int sk_diag_fill(struct sock *sk, struct sk_buff *skb,
struct netlink_diag_req *req,
u32 portid, u32 seq, u32 flags, int sk_ino)
{
struct nlmsghdr *nlh;
struct netlink_diag_msg *rep;
struct netlink_sock *nlk = nlk_sk(sk);
nlh = nlmsg_put(skb, portid, seq, SOCK_DIAG_BY_FAMILY, sizeof(*rep),
flags);
if (!nlh)
return -EMSGSIZE;
rep = nlmsg_data(nlh);
rep->ndiag_family = AF_NETLINK;
rep->ndiag_type = sk->sk_type;
rep->ndiag_protocol = sk->sk_protocol;
rep->ndiag_state = sk->sk_state;
rep->ndiag_ino = sk_ino;
rep->ndiag_portid = nlk->portid;
rep->ndiag_dst_portid = nlk->dst_portid;
rep->ndiag_dst_group = nlk->dst_group;
sock_diag_save_cookie(sk, rep->ndiag_cookie);
if ((req->ndiag_show & NDIAG_SHOW_GROUPS) &&
sk_diag_dump_groups(sk, skb))
goto out_nlmsg_trim;
if ((req->ndiag_show & NDIAG_SHOW_MEMINFO) &&
sock_diag_put_meminfo(sk, skb, NETLINK_DIAG_MEMINFO))
goto out_nlmsg_trim;
return nlmsg_end(skb, nlh);
out_nlmsg_trim:
nlmsg_cancel(skb, nlh);
return -EMSGSIZE;
}
static int __netlink_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
int protocol, int s_num)
{
struct netlink_table *tbl = &nl_table[protocol];
struct nl_portid_hash *hash = &tbl->hash;
struct net *net = sock_net(skb->sk);
struct netlink_diag_req *req;
struct sock *sk;
int ret = 0, num = 0, i;
req = nlmsg_data(cb->nlh);
for (i = 0; i <= hash->mask; i++) {
sk_for_each(sk, &hash->table[i]) {
if (!net_eq(sock_net(sk), net))
continue;
if (num < s_num) {
num++;
continue;
}
if (sk_diag_fill(sk, skb, req,
NETLINK_CB(cb->skb).portid,
cb->nlh->nlmsg_seq,
NLM_F_MULTI,
sock_i_ino(sk)) < 0) {
ret = 1;
goto done;
}
num++;
}
}
sk_for_each_bound(sk, &tbl->mc_list) {
if (sk_hashed(sk))
continue;
if (!net_eq(sock_net(sk), net))
continue;
if (num < s_num) {
num++;
continue;
}
if (sk_diag_fill(sk, skb, req,
NETLINK_CB(cb->skb).portid,
cb->nlh->nlmsg_seq,
NLM_F_MULTI,
sock_i_ino(sk)) < 0) {
ret = 1;
goto done;
}
num++;
}
done:
cb->args[0] = num;
cb->args[1] = protocol;
return ret;
}
static int netlink_diag_dump(struct sk_buff *skb, struct netlink_callback *cb)
{
struct netlink_diag_req *req;
int s_num = cb->args[0];
req = nlmsg_data(cb->nlh);
read_lock(&nl_table_lock);
if (req->sdiag_protocol == NDIAG_PROTO_ALL) {
int i;
for (i = cb->args[1]; i < MAX_LINKS; i++) {
if (__netlink_diag_dump(skb, cb, i, s_num))
break;
s_num = 0;
}
} else {
if (req->sdiag_protocol >= MAX_LINKS) {
read_unlock(&nl_table_lock);
return -ENOENT;
}
__netlink_diag_dump(skb, cb, req->sdiag_protocol, s_num);
}
read_unlock(&nl_table_lock);
return skb->len;
}
static int netlink_diag_handler_dump(struct sk_buff *skb, struct nlmsghdr *h)
{
int hdrlen = sizeof(struct netlink_diag_req);
struct net *net = sock_net(skb->sk);
if (nlmsg_len(h) < hdrlen)
return -EINVAL;
if (h->nlmsg_flags & NLM_F_DUMP) {
struct netlink_dump_control c = {
.dump = netlink_diag_dump,
};
return netlink_dump_start(net->diag_nlsk, skb, h, &c);
} else
return -EOPNOTSUPP;
}
static const struct sock_diag_handler netlink_diag_handler = {
.family = AF_NETLINK,
.dump = netlink_diag_handler_dump,
};
static int __init netlink_diag_init(void)
{
return sock_diag_register(&netlink_diag_handler);
}
static void __exit netlink_diag_exit(void)
{
sock_diag_unregister(&netlink_diag_handler);
}
module_init(netlink_diag_init);
module_exit(netlink_diag_exit);
MODULE_LICENSE("GPL");
MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 16 /* AF_NETLINK */);
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