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-rw-r--r--net/mptcp/mptcp_diag.c248
1 files changed, 248 insertions, 0 deletions
diff --git a/net/mptcp/mptcp_diag.c b/net/mptcp/mptcp_diag.c
new file mode 100644
index 000000000..8df1bdb64
--- /dev/null
+++ b/net/mptcp/mptcp_diag.c
@@ -0,0 +1,248 @@
+// SPDX-License-Identifier: GPL-2.0
+/* MPTCP socket monitoring support
+ *
+ * Copyright (c) 2020 Red Hat
+ *
+ * Author: Paolo Abeni <pabeni@redhat.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/net.h>
+#include <linux/inet_diag.h>
+#include <net/netlink.h>
+#include <uapi/linux/mptcp.h>
+#include "protocol.h"
+
+static int sk_diag_dump(struct sock *sk, struct sk_buff *skb,
+ struct netlink_callback *cb,
+ const struct inet_diag_req_v2 *req,
+ struct nlattr *bc, bool net_admin)
+{
+ if (!inet_diag_bc_sk(bc, sk))
+ return 0;
+
+ return inet_sk_diag_fill(sk, inet_csk(sk), skb, cb, req, NLM_F_MULTI,
+ net_admin);
+}
+
+static int mptcp_diag_dump_one(struct netlink_callback *cb,
+ const struct inet_diag_req_v2 *req)
+{
+ struct sk_buff *in_skb = cb->skb;
+ struct mptcp_sock *msk = NULL;
+ struct sk_buff *rep;
+ int err = -ENOENT;
+ struct net *net;
+ struct sock *sk;
+
+ net = sock_net(in_skb->sk);
+ msk = mptcp_token_get_sock(net, req->id.idiag_cookie[0]);
+ if (!msk)
+ goto out_nosk;
+
+ err = -ENOMEM;
+ sk = (struct sock *)msk;
+ rep = nlmsg_new(nla_total_size(sizeof(struct inet_diag_msg)) +
+ inet_diag_msg_attrs_size() +
+ nla_total_size(sizeof(struct mptcp_info)) +
+ nla_total_size(sizeof(struct inet_diag_meminfo)) + 64,
+ GFP_KERNEL);
+ if (!rep)
+ goto out;
+
+ err = inet_sk_diag_fill(sk, inet_csk(sk), rep, cb, req, 0,
+ netlink_net_capable(in_skb, CAP_NET_ADMIN));
+ if (err < 0) {
+ WARN_ON(err == -EMSGSIZE);
+ kfree_skb(rep);
+ goto out;
+ }
+ err = nlmsg_unicast(net->diag_nlsk, rep, NETLINK_CB(in_skb).portid);
+
+out:
+ sock_put(sk);
+
+out_nosk:
+ return err;
+}
+
+struct mptcp_diag_ctx {
+ long s_slot;
+ long s_num;
+ unsigned int l_slot;
+ unsigned int l_num;
+};
+
+static void mptcp_diag_dump_listeners(struct sk_buff *skb, struct netlink_callback *cb,
+ const struct inet_diag_req_v2 *r,
+ bool net_admin)
+{
+ struct inet_diag_dump_data *cb_data = cb->data;
+ struct mptcp_diag_ctx *diag_ctx = (void *)cb->ctx;
+ struct nlattr *bc = cb_data->inet_diag_nla_bc;
+ struct net *net = sock_net(skb->sk);
+ struct inet_hashinfo *hinfo;
+ int i;
+
+ hinfo = net->ipv4.tcp_death_row.hashinfo;
+
+ for (i = diag_ctx->l_slot; i <= hinfo->lhash2_mask; i++) {
+ struct inet_listen_hashbucket *ilb;
+ struct hlist_nulls_node *node;
+ struct sock *sk;
+ int num = 0;
+
+ ilb = &hinfo->lhash2[i];
+
+ rcu_read_lock();
+ spin_lock(&ilb->lock);
+ sk_nulls_for_each(sk, node, &ilb->nulls_head) {
+ const struct mptcp_subflow_context *ctx = mptcp_subflow_ctx(sk);
+ struct inet_sock *inet = inet_sk(sk);
+ int ret;
+
+ if (num < diag_ctx->l_num)
+ goto next_listen;
+
+ if (!ctx || strcmp(inet_csk(sk)->icsk_ulp_ops->name, "mptcp"))
+ goto next_listen;
+
+ sk = ctx->conn;
+ if (!sk || !net_eq(sock_net(sk), net))
+ goto next_listen;
+
+ if (r->sdiag_family != AF_UNSPEC &&
+ sk->sk_family != r->sdiag_family)
+ goto next_listen;
+
+ if (r->id.idiag_sport != inet->inet_sport &&
+ r->id.idiag_sport)
+ goto next_listen;
+
+ if (!refcount_inc_not_zero(&sk->sk_refcnt))
+ goto next_listen;
+
+ ret = sk_diag_dump(sk, skb, cb, r, bc, net_admin);
+
+ sock_put(sk);
+
+ if (ret < 0) {
+ spin_unlock(&ilb->lock);
+ rcu_read_unlock();
+ diag_ctx->l_slot = i;
+ diag_ctx->l_num = num;
+ return;
+ }
+ diag_ctx->l_num = num + 1;
+ num = 0;
+next_listen:
+ ++num;
+ }
+ spin_unlock(&ilb->lock);
+ rcu_read_unlock();
+
+ cond_resched();
+ diag_ctx->l_num = 0;
+ }
+
+ diag_ctx->l_num = 0;
+ diag_ctx->l_slot = i;
+}
+
+static void mptcp_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
+ const struct inet_diag_req_v2 *r)
+{
+ bool net_admin = netlink_net_capable(cb->skb, CAP_NET_ADMIN);
+ struct mptcp_diag_ctx *diag_ctx = (void *)cb->ctx;
+ struct net *net = sock_net(skb->sk);
+ struct inet_diag_dump_data *cb_data;
+ struct mptcp_sock *msk;
+ struct nlattr *bc;
+
+ BUILD_BUG_ON(sizeof(cb->ctx) < sizeof(*diag_ctx));
+
+ cb_data = cb->data;
+ bc = cb_data->inet_diag_nla_bc;
+
+ while ((msk = mptcp_token_iter_next(net, &diag_ctx->s_slot,
+ &diag_ctx->s_num)) != NULL) {
+ struct inet_sock *inet = (struct inet_sock *)msk;
+ struct sock *sk = (struct sock *)msk;
+ int ret = 0;
+
+ if (!(r->idiag_states & (1 << sk->sk_state)))
+ goto next;
+ if (r->sdiag_family != AF_UNSPEC &&
+ sk->sk_family != r->sdiag_family)
+ goto next;
+ if (r->id.idiag_sport != inet->inet_sport &&
+ r->id.idiag_sport)
+ goto next;
+ if (r->id.idiag_dport != inet->inet_dport &&
+ r->id.idiag_dport)
+ goto next;
+
+ ret = sk_diag_dump(sk, skb, cb, r, bc, net_admin);
+next:
+ sock_put(sk);
+ if (ret < 0) {
+ /* will retry on the same position */
+ diag_ctx->s_num--;
+ break;
+ }
+ cond_resched();
+ }
+
+ if ((r->idiag_states & TCPF_LISTEN) && r->id.idiag_dport == 0)
+ mptcp_diag_dump_listeners(skb, cb, r, net_admin);
+}
+
+static void mptcp_diag_get_info(struct sock *sk, struct inet_diag_msg *r,
+ void *_info)
+{
+ struct mptcp_sock *msk = mptcp_sk(sk);
+ struct mptcp_info *info = _info;
+
+ r->idiag_rqueue = sk_rmem_alloc_get(sk);
+ r->idiag_wqueue = sk_wmem_alloc_get(sk);
+
+ if (inet_sk_state_load(sk) == TCP_LISTEN) {
+ struct sock *lsk = READ_ONCE(msk->first);
+
+ if (lsk) {
+ /* override with settings from tcp listener,
+ * so Send-Q will show accept queue.
+ */
+ r->idiag_rqueue = READ_ONCE(lsk->sk_ack_backlog);
+ r->idiag_wqueue = READ_ONCE(lsk->sk_max_ack_backlog);
+ }
+ }
+
+ if (!info)
+ return;
+
+ mptcp_diag_fill_info(msk, info);
+}
+
+static const struct inet_diag_handler mptcp_diag_handler = {
+ .dump = mptcp_diag_dump,
+ .dump_one = mptcp_diag_dump_one,
+ .idiag_get_info = mptcp_diag_get_info,
+ .idiag_type = IPPROTO_MPTCP,
+ .idiag_info_size = sizeof(struct mptcp_info),
+};
+
+static int __init mptcp_diag_init(void)
+{
+ return inet_diag_register(&mptcp_diag_handler);
+}
+
+static void __exit mptcp_diag_exit(void)
+{
+ inet_diag_unregister(&mptcp_diag_handler);
+}
+
+module_init(mptcp_diag_init);
+module_exit(mptcp_diag_exit);
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-262 /* AF_INET - IPPROTO_MPTCP */);