1// SPDX-License-Identifier: GPL-2.0 2/* MPTCP socket monitoring support 3 * 4 * Copyright (c) 2020 Red Hat 5 * 6 * Author: Paolo Abeni <pabeni@redhat.com> 7 */ 8 9#include <linux/kernel.h> 10#include <linux/net.h> 11#include <linux/inet_diag.h> 12#include <net/netlink.h> 13#include <uapi/linux/mptcp.h> 14#include "protocol.h" 15 16static int sk_diag_dump(struct sock *sk, struct sk_buff *skb, 17 struct netlink_callback *cb, 18 const struct inet_diag_req_v2 *req, 19 struct nlattr *bc, bool net_admin) 20{ 21 if (!inet_diag_bc_sk(bc, sk)) 22 return 0; 23 24 return inet_sk_diag_fill(sk, inet_csk(sk), skb, cb, req, NLM_F_MULTI, 25 net_admin); 26} 27 28static int mptcp_diag_dump_one(struct netlink_callback *cb, 29 const struct inet_diag_req_v2 *req) 30{ 31 struct sk_buff *in_skb = cb->skb; 32 struct mptcp_sock *msk = NULL; 33 struct sk_buff *rep; 34 int err = -ENOENT; 35 struct net *net; 36 struct sock *sk; 37 38 net = sock_net(in_skb->sk); 39 msk = mptcp_token_get_sock(net, req->id.idiag_cookie[0]); 40 if (!msk) 41 goto out_nosk; 42 43 err = -ENOMEM; 44 sk = (struct sock *)msk; 45 rep = nlmsg_new(nla_total_size(sizeof(struct inet_diag_msg)) + 46 inet_diag_msg_attrs_size() + 47 nla_total_size(sizeof(struct mptcp_info)) + 48 nla_total_size(sizeof(struct inet_diag_meminfo)) + 64, 49 GFP_KERNEL); 50 if (!rep) 51 goto out; 52 53 err = inet_sk_diag_fill(sk, inet_csk(sk), rep, cb, req, 0, 54 netlink_net_capable(in_skb, CAP_NET_ADMIN)); 55 if (err < 0) { 56 WARN_ON(err == -EMSGSIZE); 57 kfree_skb(rep); 58 goto out; 59 } 60 err = netlink_unicast(net->diag_nlsk, rep, NETLINK_CB(in_skb).portid, 61 MSG_DONTWAIT); 62 if (err > 0) 63 err = 0; 64out: 65 sock_put(sk); 66 67out_nosk: 68 return err; 69} 70 71static void mptcp_diag_dump(struct sk_buff *skb, struct netlink_callback *cb, 72 const struct inet_diag_req_v2 *r) 73{ 74 bool net_admin = netlink_net_capable(cb->skb, CAP_NET_ADMIN); 75 struct net *net = sock_net(skb->sk); 76 struct inet_diag_dump_data *cb_data; 77 struct mptcp_sock *msk; 78 struct nlattr *bc; 79 80 cb_data = cb->data; 81 bc = cb_data->inet_diag_nla_bc; 82 83 while ((msk = mptcp_token_iter_next(net, &cb->args[0], &cb->args[1])) != 84 NULL) { 85 struct inet_sock *inet = (struct inet_sock *)msk; 86 struct sock *sk = (struct sock *)msk; 87 int ret = 0; 88 89 if (!(r->idiag_states & (1 << sk->sk_state))) 90 goto next; 91 if (r->sdiag_family != AF_UNSPEC && 92 sk->sk_family != r->sdiag_family) 93 goto next; 94 if (r->id.idiag_sport != inet->inet_sport && 95 r->id.idiag_sport) 96 goto next; 97 if (r->id.idiag_dport != inet->inet_dport && 98 r->id.idiag_dport) 99 goto next; 100 101 ret = sk_diag_dump(sk, skb, cb, r, bc, net_admin); 102next: 103 sock_put(sk); 104 if (ret < 0) { 105 /* will retry on the same position */ 106 cb->args[1]--; 107 break; 108 } 109 cond_resched(); 110 } 111} 112 113static void mptcp_diag_get_info(struct sock *sk, struct inet_diag_msg *r, 114 void *_info) 115{ 116 struct mptcp_sock *msk = mptcp_sk(sk); 117 struct mptcp_info *info = _info; 118 u32 flags = 0; 119 bool slow; 120 u8 val; 121 122 r->idiag_rqueue = sk_rmem_alloc_get(sk); 123 r->idiag_wqueue = sk_wmem_alloc_get(sk); 124 if (!info) 125 return; 126 127 slow = lock_sock_fast(sk); 128 info->mptcpi_subflows = READ_ONCE(msk->pm.subflows); 129 info->mptcpi_add_addr_signal = READ_ONCE(msk->pm.add_addr_signaled); 130 info->mptcpi_add_addr_accepted = READ_ONCE(msk->pm.add_addr_accepted); 131 info->mptcpi_subflows_max = READ_ONCE(msk->pm.subflows_max); 132 val = READ_ONCE(msk->pm.add_addr_signal_max); 133 info->mptcpi_add_addr_signal_max = val; 134 val = READ_ONCE(msk->pm.add_addr_accept_max); 135 info->mptcpi_add_addr_accepted_max = val; 136 if (test_bit(MPTCP_FALLBACK_DONE, &msk->flags)) 137 flags |= MPTCP_INFO_FLAG_FALLBACK; 138 if (READ_ONCE(msk->can_ack)) 139 flags |= MPTCP_INFO_FLAG_REMOTE_KEY_RECEIVED; 140 info->mptcpi_flags = flags; 141 info->mptcpi_token = READ_ONCE(msk->token); 142 info->mptcpi_write_seq = READ_ONCE(msk->write_seq); 143 info->mptcpi_snd_una = atomic64_read(&msk->snd_una); 144 info->mptcpi_rcv_nxt = READ_ONCE(msk->ack_seq); 145 unlock_sock_fast(sk, slow); 146} 147 148static const struct inet_diag_handler mptcp_diag_handler = { 149 .dump = mptcp_diag_dump, 150 .dump_one = mptcp_diag_dump_one, 151 .idiag_get_info = mptcp_diag_get_info, 152 .idiag_type = IPPROTO_MPTCP, 153 .idiag_info_size = sizeof(struct mptcp_info), 154}; 155 156static int __init mptcp_diag_init(void) 157{ 158 return inet_diag_register(&mptcp_diag_handler); 159} 160 161static void __exit mptcp_diag_exit(void) 162{ 163 inet_diag_unregister(&mptcp_diag_handler); 164} 165 166module_init(mptcp_diag_init); 167module_exit(mptcp_diag_exit); 168MODULE_LICENSE("GPL"); 169MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-262 /* AF_INET - IPPROTO_MPTCP */); 170