3 files changed, 114 insertions, 0 deletions
diff --git a/net/packet/Kconfig b/net/packet/Kconfig
index 0060e3b396b..cc55b35f80e 100644
--- a/net/packet/Kconfig
+++ b/net/packet/Kconfig
@@ -14,3 +14,11 @@ config PACKET
 	  be called af_packet.
 
 	  If unsure, say Y.
+
+config PACKET_DIAG
+	tristate "Packet: sockets monitoring interface"
+	depends on PACKET
+	default n
+	---help---
+	  Support for PF_PACKET sockets monitoring interface used by the ss tool.
+	  If unsure, say Y.
diff --git a/net/packet/Makefile b/net/packet/Makefile
index 81183eabfde..9df61347a3c 100644
--- a/net/packet/Makefile
+++ b/net/packet/Makefile
@@ -3,3 +3,5 @@
 #
 
 obj-$(CONFIG_PACKET) += af_packet.o
+obj-$(CONFIG_PACKET_DIAG) += af_packet_diag.o
+af_packet_diag-y += diag.o
diff --git a/net/packet/diag.c b/net/packet/diag.c
new file mode 100644
index 00000000000..ff2f7f5bfb8
--- /dev/null
+++ b/net/packet/diag.c
@@ -0,0 +1,104 @@
+#include <linux/module.h>
+#include <linux/sock_diag.h>
+#include <linux/net.h>
+#include <linux/packet_diag.h>
+#include <net/net_namespace.h>
+#include <net/sock.h>
+
+#include "internal.h"
+
+static int sk_diag_fill(struct sock *sk, struct sk_buff *skb, struct packet_diag_req *req,
+		u32 pid, u32 seq, u32 flags, int sk_ino)
+{
+	struct nlmsghdr *nlh;
+	struct packet_diag_msg *rp;
+	const struct packet_sock *po = pkt_sk(sk);
+
+	nlh = nlmsg_put(skb, pid, seq, SOCK_DIAG_BY_FAMILY, sizeof(*rp), flags);
+	if (!nlh)
+		return -EMSGSIZE;
+
+	rp = nlmsg_data(nlh);
+	rp->pdiag_family = AF_PACKET;
+	rp->pdiag_type = sk->sk_type;
+	rp->pdiag_num = ntohs(po->num);
+	rp->pdiag_ino = sk_ino;
+	sock_diag_save_cookie(sk, rp->pdiag_cookie);
+
+	return nlmsg_end(skb, nlh);
+}
+
+static int packet_diag_dump(struct sk_buff *skb, struct netlink_callback *cb)
+{
+	int num = 0, s_num = cb->args[0];
+	struct packet_diag_req *req;
+	struct net *net;
+	struct sock *sk;
+	struct hlist_node *node;
+
+	net = sock_net(skb->sk);
+	req = nlmsg_data(cb->nlh);
+
+	rcu_read_lock();
+	sk_for_each_rcu(sk, node, &net->packet.sklist) {
+		if (!net_eq(sock_net(sk), net))
+			continue;
+		if (num < s_num)
+			goto next;
+
+		if (sk_diag_fill(sk, skb, req, NETLINK_CB(cb->skb).pid,
+					cb->nlh->nlmsg_seq, NLM_F_MULTI,
+					sock_i_ino(sk)) < 0)
+			goto done;
+next:
+		num++;
+	}
+done:
+	rcu_read_unlock();
+	cb->args[0] = num;
+
+	return skb->len;
+}
+
+static int packet_diag_handler_dump(struct sk_buff *skb, struct nlmsghdr *h)
+{
+	int hdrlen = sizeof(struct packet_diag_req);
+	struct net *net = sock_net(skb->sk);
+	struct packet_diag_req *req;
+
+	if (nlmsg_len(h) < hdrlen)
+		return -EINVAL;
+
+	req = nlmsg_data(h);
+	/* Make it possible to support protocol filtering later */
+	if (req->sdiag_protocol)
+		return -EINVAL;
+
+	if (h->nlmsg_flags & NLM_F_DUMP) {
+		struct netlink_dump_control c = {
+			.dump = packet_diag_dump,
+		};
+		return netlink_dump_start(net->diag_nlsk, skb, h, &c);
+	} else
+		return -EOPNOTSUPP;
+}
+
+static const struct sock_diag_handler packet_diag_handler = {
+	.family = AF_PACKET,
+	.dump = packet_diag_handler_dump,
+};
+
+static int __init packet_diag_init(void)
+{
+	return sock_diag_register(&packet_diag_handler);
+}
+
+static void __exit packet_diag_exit(void)
+{
+	sock_diag_unregister(&packet_diag_handler);
+}
+
+module_init(packet_diag_init);
+module_exit(packet_diag_exit);
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 17 /* AF_PACKET */);