diff options
Diffstat (limited to 'net/mptcp/mptcp_diag.c')
| -rw-r--r-- | net/mptcp/mptcp_diag.c | 248 |
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 000000000000..8df1bdb647e2 --- /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 */); |