linux_dsm_epyc7002/include/net/inet_timewait_sock.h
Eric Dumazet 66b13d99d9 ipv4: tcp: fix TOS value in ACK messages sent from TIME_WAIT
There is a long standing bug in linux tcp stack, about ACK messages sent
on behalf of TIME_WAIT sockets.

In the IP header of the ACK message, we choose to reflect TOS field of
incoming message, and this might break some setups.

Example of things that were broken :
  - Routing using TOS as a selector
  - Firewalls
  - Trafic classification / shaping

We now remember in timewait structure the inet tos field and use it in
ACK generation, and route lookup.

Notes :
 - We still reflect incoming TOS in RST messages.
 - We could extend MuraliRaja Muniraju patch to report TOS value in
netlink messages for TIME_WAIT sockets.
 - A patch is needed for IPv6

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-10-24 03:06:21 -04:00

238 lines
6.9 KiB
C

/*
* INET An implementation of the TCP/IP protocol suite for the LINUX
* operating system. INET is implemented using the BSD Socket
* interface as the means of communication with the user level.
*
* Definitions for a generic INET TIMEWAIT sock
*
* From code originally in net/tcp.h
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#ifndef _INET_TIMEWAIT_SOCK_
#define _INET_TIMEWAIT_SOCK_
#include <linux/kmemcheck.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/timer.h>
#include <linux/types.h>
#include <linux/workqueue.h>
#include <net/inet_sock.h>
#include <net/sock.h>
#include <net/tcp_states.h>
#include <net/timewait_sock.h>
#include <linux/atomic.h>
struct inet_hashinfo;
#define INET_TWDR_RECYCLE_SLOTS_LOG 5
#define INET_TWDR_RECYCLE_SLOTS (1 << INET_TWDR_RECYCLE_SLOTS_LOG)
/*
* If time > 4sec, it is "slow" path, no recycling is required,
* so that we select tick to get range about 4 seconds.
*/
#if HZ <= 16 || HZ > 4096
# error Unsupported: HZ <= 16 or HZ > 4096
#elif HZ <= 32
# define INET_TWDR_RECYCLE_TICK (5 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG)
#elif HZ <= 64
# define INET_TWDR_RECYCLE_TICK (6 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG)
#elif HZ <= 128
# define INET_TWDR_RECYCLE_TICK (7 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG)
#elif HZ <= 256
# define INET_TWDR_RECYCLE_TICK (8 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG)
#elif HZ <= 512
# define INET_TWDR_RECYCLE_TICK (9 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG)
#elif HZ <= 1024
# define INET_TWDR_RECYCLE_TICK (10 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG)
#elif HZ <= 2048
# define INET_TWDR_RECYCLE_TICK (11 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG)
#else
# define INET_TWDR_RECYCLE_TICK (12 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG)
#endif
/* TIME_WAIT reaping mechanism. */
#define INET_TWDR_TWKILL_SLOTS 8 /* Please keep this a power of 2. */
#define INET_TWDR_TWKILL_QUOTA 100
struct inet_timewait_death_row {
/* Short-time timewait calendar */
int twcal_hand;
unsigned long twcal_jiffie;
struct timer_list twcal_timer;
struct hlist_head twcal_row[INET_TWDR_RECYCLE_SLOTS];
spinlock_t death_lock;
int tw_count;
int period;
u32 thread_slots;
struct work_struct twkill_work;
struct timer_list tw_timer;
int slot;
struct hlist_head cells[INET_TWDR_TWKILL_SLOTS];
struct inet_hashinfo *hashinfo;
int sysctl_tw_recycle;
int sysctl_max_tw_buckets;
};
extern void inet_twdr_hangman(unsigned long data);
extern void inet_twdr_twkill_work(struct work_struct *work);
extern void inet_twdr_twcal_tick(unsigned long data);
struct inet_bind_bucket;
/*
* This is a TIME_WAIT sock. It works around the memory consumption
* problems of sockets in such a state on heavily loaded servers, but
* without violating the protocol specification.
*/
struct inet_timewait_sock {
/*
* Now struct sock also uses sock_common, so please just
* don't add nothing before this first member (__tw_common) --acme
*/
struct sock_common __tw_common;
#define tw_family __tw_common.skc_family
#define tw_state __tw_common.skc_state
#define tw_reuse __tw_common.skc_reuse
#define tw_bound_dev_if __tw_common.skc_bound_dev_if
#define tw_node __tw_common.skc_nulls_node
#define tw_bind_node __tw_common.skc_bind_node
#define tw_refcnt __tw_common.skc_refcnt
#define tw_hash __tw_common.skc_hash
#define tw_prot __tw_common.skc_prot
#define tw_net __tw_common.skc_net
#define tw_daddr __tw_common.skc_daddr
#define tw_rcv_saddr __tw_common.skc_rcv_saddr
int tw_timeout;
volatile unsigned char tw_substate;
unsigned char tw_rcv_wscale;
/* Socket demultiplex comparisons on incoming packets. */
/* these three are in inet_sock */
__be16 tw_sport;
__be16 tw_dport;
__u16 tw_num;
kmemcheck_bitfield_begin(flags);
/* And these are ours. */
unsigned int tw_ipv6only : 1,
tw_transparent : 1,
tw_pad : 6, /* 6 bits hole */
tw_tos : 8,
tw_ipv6_offset : 16;
kmemcheck_bitfield_end(flags);
unsigned long tw_ttd;
struct inet_bind_bucket *tw_tb;
struct hlist_node tw_death_node;
};
static inline void inet_twsk_add_node_rcu(struct inet_timewait_sock *tw,
struct hlist_nulls_head *list)
{
hlist_nulls_add_head_rcu(&tw->tw_node, list);
}
static inline void inet_twsk_add_bind_node(struct inet_timewait_sock *tw,
struct hlist_head *list)
{
hlist_add_head(&tw->tw_bind_node, list);
}
static inline int inet_twsk_dead_hashed(const struct inet_timewait_sock *tw)
{
return !hlist_unhashed(&tw->tw_death_node);
}
static inline void inet_twsk_dead_node_init(struct inet_timewait_sock *tw)
{
tw->tw_death_node.pprev = NULL;
}
static inline void __inet_twsk_del_dead_node(struct inet_timewait_sock *tw)
{
__hlist_del(&tw->tw_death_node);
inet_twsk_dead_node_init(tw);
}
static inline int inet_twsk_del_dead_node(struct inet_timewait_sock *tw)
{
if (inet_twsk_dead_hashed(tw)) {
__inet_twsk_del_dead_node(tw);
return 1;
}
return 0;
}
#define inet_twsk_for_each(tw, node, head) \
hlist_nulls_for_each_entry(tw, node, head, tw_node)
#define inet_twsk_for_each_inmate(tw, node, jail) \
hlist_for_each_entry(tw, node, jail, tw_death_node)
#define inet_twsk_for_each_inmate_safe(tw, node, safe, jail) \
hlist_for_each_entry_safe(tw, node, safe, jail, tw_death_node)
static inline struct inet_timewait_sock *inet_twsk(const struct sock *sk)
{
return (struct inet_timewait_sock *)sk;
}
static inline __be32 sk_rcv_saddr(const struct sock *sk)
{
/* both inet_sk() and inet_twsk() store rcv_saddr in skc_rcv_saddr */
return sk->__sk_common.skc_rcv_saddr;
}
extern void inet_twsk_put(struct inet_timewait_sock *tw);
extern int inet_twsk_unhash(struct inet_timewait_sock *tw);
extern int inet_twsk_bind_unhash(struct inet_timewait_sock *tw,
struct inet_hashinfo *hashinfo);
extern struct inet_timewait_sock *inet_twsk_alloc(const struct sock *sk,
const int state);
extern void __inet_twsk_hashdance(struct inet_timewait_sock *tw,
struct sock *sk,
struct inet_hashinfo *hashinfo);
extern void inet_twsk_schedule(struct inet_timewait_sock *tw,
struct inet_timewait_death_row *twdr,
const int timeo, const int timewait_len);
extern void inet_twsk_deschedule(struct inet_timewait_sock *tw,
struct inet_timewait_death_row *twdr);
extern void inet_twsk_purge(struct inet_hashinfo *hashinfo,
struct inet_timewait_death_row *twdr, int family);
static inline
struct net *twsk_net(const struct inet_timewait_sock *twsk)
{
#ifdef CONFIG_NET_NS
return rcu_dereference_raw(twsk->tw_net); /* protected by locking, */
/* reference counting, */
/* initialization, or RCU. */
#else
return &init_net;
#endif
}
static inline
void twsk_net_set(struct inet_timewait_sock *twsk, struct net *net)
{
#ifdef CONFIG_NET_NS
rcu_assign_pointer(twsk->tw_net, net);
#endif
}
#endif /* _INET_TIMEWAIT_SOCK_ */