forked from Minki/linux
00fd38d938
Some functions access TCP sockets without holding a lock and might output non consistent data, depending on compiler and or architecture. tcp_diag_get_info(), tcp_get_info(), tcp_poll(), get_tcp4_sock() ... Introduce sk_state_load() and sk_state_store() to fix the issues, and more clearly document where this lack of locking is happening. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
71 lines
1.9 KiB
C
71 lines
1.9 KiB
C
/*
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* tcp_diag.c Module for monitoring TCP transport protocols sockets.
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*
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* Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#include <linux/module.h>
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#include <linux/inet_diag.h>
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#include <linux/tcp.h>
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#include <net/tcp.h>
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static void tcp_diag_get_info(struct sock *sk, struct inet_diag_msg *r,
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void *_info)
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{
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struct tcp_info *info = _info;
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if (sk_state_load(sk) == TCP_LISTEN) {
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r->idiag_rqueue = sk->sk_ack_backlog;
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r->idiag_wqueue = sk->sk_max_ack_backlog;
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} else if (sk->sk_type == SOCK_STREAM) {
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const struct tcp_sock *tp = tcp_sk(sk);
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r->idiag_rqueue = max_t(int, tp->rcv_nxt - tp->copied_seq, 0);
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r->idiag_wqueue = tp->write_seq - tp->snd_una;
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}
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if (info)
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tcp_get_info(sk, info);
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}
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static void tcp_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
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const struct inet_diag_req_v2 *r, struct nlattr *bc)
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{
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inet_diag_dump_icsk(&tcp_hashinfo, skb, cb, r, bc);
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}
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static int tcp_diag_dump_one(struct sk_buff *in_skb, const struct nlmsghdr *nlh,
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const struct inet_diag_req_v2 *req)
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{
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return inet_diag_dump_one_icsk(&tcp_hashinfo, in_skb, nlh, req);
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}
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static const struct inet_diag_handler tcp_diag_handler = {
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.dump = tcp_diag_dump,
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.dump_one = tcp_diag_dump_one,
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.idiag_get_info = tcp_diag_get_info,
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.idiag_type = IPPROTO_TCP,
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.idiag_info_size = sizeof(struct tcp_info),
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};
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static int __init tcp_diag_init(void)
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{
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return inet_diag_register(&tcp_diag_handler);
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}
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static void __exit tcp_diag_exit(void)
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{
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inet_diag_unregister(&tcp_diag_handler);
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}
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module_init(tcp_diag_init);
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module_exit(tcp_diag_exit);
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MODULE_LICENSE("GPL");
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MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-6 /* AF_INET - IPPROTO_TCP */);
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