1 files changed, 340 insertions, 0 deletions

diff --git a/net/core/sock_diag.c b/net/core/sock_diag.c
new file mode 100644
index 000000000..f7cf74cdd
--- /dev/null
+++ b/net/core/sock_diag.c
@@ -0,0 +1,340 @@
+/* License: GPL */
+
+#include <linux/filter.h>
+#include <linux/mutex.h>
+#include <linux/socket.h>
+#include <linux/skbuff.h>
+#include <net/netlink.h>
+#include <net/net_namespace.h>
+#include <linux/module.h>
+#include <net/sock.h>
+#include <linux/kernel.h>
+#include <linux/tcp.h>
+#include <linux/workqueue.h>
+#include <linux/nospec.h>
+#include <linux/cookie.h>
+#include <linux/inet_diag.h>
+#include <linux/sock_diag.h>
+
+static const struct sock_diag_handler *sock_diag_handlers[AF_MAX];
+static int (*inet_rcv_compat)(struct sk_buff *skb, struct nlmsghdr *nlh);
+static DEFINE_MUTEX(sock_diag_table_mutex);
+static struct workqueue_struct *broadcast_wq;
+
+DEFINE_COOKIE(sock_cookie);
+
+u64 __sock_gen_cookie(struct sock *sk)
+{
+	while (1) {
+		u64 res = atomic64_read(&sk->sk_cookie);
+
+		if (res)
+			return res;
+		res = gen_cookie_next(&sock_cookie);
+		atomic64_cmpxchg(&sk->sk_cookie, 0, res);
+	}
+}
+
+int sock_diag_check_cookie(struct sock *sk, const __u32 *cookie)
+{
+	u64 res;
+
+	if (cookie[0] == INET_DIAG_NOCOOKIE && cookie[1] == INET_DIAG_NOCOOKIE)
+		return 0;
+
+	res = sock_gen_cookie(sk);
+	if ((u32)res != cookie[0] || (u32)(res >> 32) != cookie[1])
+		return -ESTALE;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(sock_diag_check_cookie);
+
+void sock_diag_save_cookie(struct sock *sk, __u32 *cookie)
+{
+	u64 res = sock_gen_cookie(sk);
+
+	cookie[0] = (u32)res;
+	cookie[1] = (u32)(res >> 32);
+}
+EXPORT_SYMBOL_GPL(sock_diag_save_cookie);
+
+int sock_diag_put_meminfo(struct sock *sk, struct sk_buff *skb, int attrtype)
+{
+	u32 mem[SK_MEMINFO_VARS];
+
+	sk_get_meminfo(sk, mem);
+
+	return nla_put(skb, attrtype, sizeof(mem), &mem);
+}
+EXPORT_SYMBOL_GPL(sock_diag_put_meminfo);
+
+int sock_diag_put_filterinfo(bool may_report_filterinfo, struct sock *sk,
+			     struct sk_buff *skb, int attrtype)
+{
+	struct sock_fprog_kern *fprog;
+	struct sk_filter *filter;
+	struct nlattr *attr;
+	unsigned int flen;
+	int err = 0;
+
+	if (!may_report_filterinfo) {
+		nla_reserve(skb, attrtype, 0);
+		return 0;
+	}
+
+	rcu_read_lock();
+	filter = rcu_dereference(sk->sk_filter);
+	if (!filter)
+		goto out;
+
+	fprog = filter->prog->orig_prog;
+	if (!fprog)
+		goto out;
+
+	flen = bpf_classic_proglen(fprog);
+
+	attr = nla_reserve(skb, attrtype, flen);
+	if (attr == NULL) {
+		err = -EMSGSIZE;
+		goto out;
+	}
+
+	memcpy(nla_data(attr), fprog->filter, flen);
+out:
+	rcu_read_unlock();
+	return err;
+}
+EXPORT_SYMBOL(sock_diag_put_filterinfo);
+
+struct broadcast_sk {
+	struct sock *sk;
+	struct work_struct work;
+};
+
+static size_t sock_diag_nlmsg_size(void)
+{
+	return NLMSG_ALIGN(sizeof(struct inet_diag_msg)
+	       + nla_total_size(sizeof(u8)) /* INET_DIAG_PROTOCOL */
+	       + nla_total_size_64bit(sizeof(struct tcp_info))); /* INET_DIAG_INFO */
+}
+
+static void sock_diag_broadcast_destroy_work(struct work_struct *work)
+{
+	struct broadcast_sk *bsk =
+		container_of(work, struct broadcast_sk, work);
+	struct sock *sk = bsk->sk;
+	const struct sock_diag_handler *hndl;
+	struct sk_buff *skb;
+	const enum sknetlink_groups group = sock_diag_destroy_group(sk);
+	int err = -1;
+
+	WARN_ON(group == SKNLGRP_NONE);
+
+	skb = nlmsg_new(sock_diag_nlmsg_size(), GFP_KERNEL);
+	if (!skb)
+		goto out;
+
+	mutex_lock(&sock_diag_table_mutex);
+	hndl = sock_diag_handlers[sk->sk_family];
+	if (hndl && hndl->get_info)
+		err = hndl->get_info(skb, sk);
+	mutex_unlock(&sock_diag_table_mutex);
+
+	if (!err)
+		nlmsg_multicast(sock_net(sk)->diag_nlsk, skb, 0, group,
+				GFP_KERNEL);
+	else
+		kfree_skb(skb);
+out:
+	sk_destruct(sk);
+	kfree(bsk);
+}
+
+void sock_diag_broadcast_destroy(struct sock *sk)
+{
+	/* Note, this function is often called from an interrupt context. */
+	struct broadcast_sk *bsk =
+		kmalloc(sizeof(struct broadcast_sk), GFP_ATOMIC);
+	if (!bsk)
+		return sk_destruct(sk);
+	bsk->sk = sk;
+	INIT_WORK(&bsk->work, sock_diag_broadcast_destroy_work);
+	queue_work(broadcast_wq, &bsk->work);
+}
+
+void sock_diag_register_inet_compat(int (*fn)(struct sk_buff *skb, struct nlmsghdr *nlh))
+{
+	mutex_lock(&sock_diag_table_mutex);
+	inet_rcv_compat = fn;
+	mutex_unlock(&sock_diag_table_mutex);
+}
+EXPORT_SYMBOL_GPL(sock_diag_register_inet_compat);
+
+void sock_diag_unregister_inet_compat(int (*fn)(struct sk_buff *skb, struct nlmsghdr *nlh))
+{
+	mutex_lock(&sock_diag_table_mutex);
+	inet_rcv_compat = NULL;
+	mutex_unlock(&sock_diag_table_mutex);
+}
+EXPORT_SYMBOL_GPL(sock_diag_unregister_inet_compat);
+
+int sock_diag_register(const struct sock_diag_handler *hndl)
+{
+	int err = 0;
+
+	if (hndl->family >= AF_MAX)
+		return -EINVAL;
+
+	mutex_lock(&sock_diag_table_mutex);
+	if (sock_diag_handlers[hndl->family])
+		err = -EBUSY;
+	else
+		sock_diag_handlers[hndl->family] = hndl;
+	mutex_unlock(&sock_diag_table_mutex);
+
+	return err;
+}
+EXPORT_SYMBOL_GPL(sock_diag_register);
+
+void sock_diag_unregister(const struct sock_diag_handler *hnld)
+{
+	int family = hnld->family;
+
+	if (family >= AF_MAX)
+		return;
+
+	mutex_lock(&sock_diag_table_mutex);
+	BUG_ON(sock_diag_handlers[family] != hnld);
+	sock_diag_handlers[family] = NULL;
+	mutex_unlock(&sock_diag_table_mutex);
+}
+EXPORT_SYMBOL_GPL(sock_diag_unregister);
+
+static int __sock_diag_cmd(struct sk_buff *skb, struct nlmsghdr *nlh)
+{
+	int err;
+	struct sock_diag_req *req = nlmsg_data(nlh);
+	const struct sock_diag_handler *hndl;
+
+	if (nlmsg_len(nlh) < sizeof(*req))
+		return -EINVAL;
+
+	if (req->sdiag_family >= AF_MAX)
+		return -EINVAL;
+	req->sdiag_family = array_index_nospec(req->sdiag_family, AF_MAX);
+
+	if (sock_diag_handlers[req->sdiag_family] == NULL)
+		sock_load_diag_module(req->sdiag_family, 0);
+
+	mutex_lock(&sock_diag_table_mutex);
+	hndl = sock_diag_handlers[req->sdiag_family];
+	if (hndl == NULL)
+		err = -ENOENT;
+	else if (nlh->nlmsg_type == SOCK_DIAG_BY_FAMILY)
+		err = hndl->dump(skb, nlh);
+	else if (nlh->nlmsg_type == SOCK_DESTROY && hndl->destroy)
+		err = hndl->destroy(skb, nlh);
+	else
+		err = -EOPNOTSUPP;
+	mutex_unlock(&sock_diag_table_mutex);
+
+	return err;
+}
+
+static int sock_diag_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
+			     struct netlink_ext_ack *extack)
+{
+	int ret;
+
+	switch (nlh->nlmsg_type) {
+	case TCPDIAG_GETSOCK:
+	case DCCPDIAG_GETSOCK:
+		if (inet_rcv_compat == NULL)
+			sock_load_diag_module(AF_INET, 0);
+
+		mutex_lock(&sock_diag_table_mutex);
+		if (inet_rcv_compat != NULL)
+			ret = inet_rcv_compat(skb, nlh);
+		else
+			ret = -EOPNOTSUPP;
+		mutex_unlock(&sock_diag_table_mutex);
+
+		return ret;
+	case SOCK_DIAG_BY_FAMILY:
+	case SOCK_DESTROY:
+		return __sock_diag_cmd(skb, nlh);
+	default:
+		return -EINVAL;
+	}
+}
+
+static DEFINE_MUTEX(sock_diag_mutex);
+
+static void sock_diag_rcv(struct sk_buff *skb)
+{
+	mutex_lock(&sock_diag_mutex);
+	netlink_rcv_skb(skb, &sock_diag_rcv_msg);
+	mutex_unlock(&sock_diag_mutex);
+}
+
+static int sock_diag_bind(struct net *net, int group)
+{
+	switch (group) {
+	case SKNLGRP_INET_TCP_DESTROY:
+	case SKNLGRP_INET_UDP_DESTROY:
+		if (!sock_diag_handlers[AF_INET])
+			sock_load_diag_module(AF_INET, 0);
+		break;
+	case SKNLGRP_INET6_TCP_DESTROY:
+	case SKNLGRP_INET6_UDP_DESTROY:
+		if (!sock_diag_handlers[AF_INET6])
+			sock_load_diag_module(AF_INET6, 0);
+		break;
+	}
+	return 0;
+}
+
+int sock_diag_destroy(struct sock *sk, int err)
+{
+	if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
+		return -EPERM;
+
+	if (!sk->sk_prot->diag_destroy)
+		return -EOPNOTSUPP;
+
+	return sk->sk_prot->diag_destroy(sk, err);
+}
+EXPORT_SYMBOL_GPL(sock_diag_destroy);
+
+static int __net_init diag_net_init(struct net *net)
+{
+	struct netlink_kernel_cfg cfg = {
+		.groups	= SKNLGRP_MAX,
+		.input	= sock_diag_rcv,
+		.bind	= sock_diag_bind,
+		.flags	= NL_CFG_F_NONROOT_RECV,
+	};
+
+	net->diag_nlsk = netlink_kernel_create(net, NETLINK_SOCK_DIAG, &cfg);
+	return net->diag_nlsk == NULL ? -ENOMEM : 0;
+}
+
+static void __net_exit diag_net_exit(struct net *net)
+{
+	netlink_kernel_release(net->diag_nlsk);
+	net->diag_nlsk = NULL;
+}
+
+static struct pernet_operations diag_net_ops = {
+	.init = diag_net_init,
+	.exit = diag_net_exit,
+};
+
+static int __init sock_diag_init(void)
+{
+	broadcast_wq = alloc_workqueue("sock_diag_events", 0, 0);
+	BUG_ON(!broadcast_wq);
+	return register_pernet_subsys(&diag_net_ops);
+}
+device_initcall(sock_diag_init);