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[INET]: Generalise tcp_tw_bucket, aka TIME_WAIT sockets

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This paves the way to generalise the rest of the sock ID lookup
routines and saves some bytes in TCPv4 TIME_WAIT sockets on distro
kernels (where IPv6 is always built as a module):

[root@qemu ~]# grep tw_sock /proc/slabinfo
tw_sock_TCPv6  0  0  128  31  1
tw_sock_TCP    0  0   96  41  1
[root@qemu ~]#

Now if a protocol wants to use the TIME_WAIT generic infrastructure it
only has to set the sk_prot->twsk_obj_size field with the size of its
inet_timewait_sock derived sock and proto_register will create
sk_prot->twsk_slab, for now its only for INET sockets, but we can
introduce timewait_sock later if some non INET transport protocolo
wants to use this stuff.

Next changesets will take advantage of this new infrastructure to
generalise even more TCP code.

[acme@toy net-2.6.14]$ grep built-in /tmp/before.size /tmp/after.size
/tmp/before.size: 188646   11764    5068  205478   322a6 net/ipv4/built-in.o
/tmp/after.size:  188144   11764    5068  204976   320b0 net/ipv4/built-in.o
[acme@toy net-2.6.14]$

Tested with both IPv4 & IPv6 (::1 (localhost) & ::ffff:172.20.0.1
(qemu host)).

Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Arnaldo Carvalho de Melo
2005-08-09 20:09:30 -07:00
committed by David S. Miller
parent 33b6223190
commit 8feaf0c0a5
13 changed files with 484 additions and 391 deletions
Download Patch File Download Diff File Expand all files Collapse all files

142
net/ipv4/tcp_minisocks.c
View File

@@ -41,7 +41,7 @@ int sysctl_tcp_max_tw_buckets = NR_FILE*2;
int sysctl_tcp_syncookies = SYNC_INIT;
int sysctl_tcp_abort_on_overflow;
static void tcp_tw_schedule(struct tcp_tw_bucket *tw, int timeo);
static void tcp_tw_schedule(struct inet_timewait_sock *tw, int timeo);
static __inline__ int tcp_in_window(u32 seq, u32 end_seq, u32 s_win, u32 e_win)
{
@@ -58,7 +58,7 @@ int tcp_tw_count;
/* Must be called with locally disabled BHs. */
static void tcp_timewait_kill(struct tcp_tw_bucket *tw)
static void tcp_timewait_kill(struct inet_timewait_sock *tw)
{
struct inet_bind_hashbucket *bhead;
struct inet_bind_bucket *tb;
@@ -85,11 +85,11 @@ static void tcp_timewait_kill(struct tcp_tw_bucket *tw)
#ifdef SOCK_REFCNT_DEBUG
if (atomic_read(&tw->tw_refcnt) != 1) {
printk(KERN_DEBUG "tw_bucket %p refcnt=%d\n", tw,
atomic_read(&tw->tw_refcnt));
printk(KERN_DEBUG "%s timewait_sock %p refcnt=%d\n",
tw->tw_prot->name, tw, atomic_read(&tw->tw_refcnt));
}
#endif
tcp_tw_put(tw);
inet_twsk_put(tw);
}
/*
@@ -121,19 +121,20 @@ static void tcp_timewait_kill(struct tcp_tw_bucket *tw)
* to avoid misread sequence numbers, states etc. --ANK
*/
enum tcp_tw_status
tcp_timewait_state_process(struct tcp_tw_bucket *tw, struct sk_buff *skb,
struct tcphdr *th, unsigned len)
tcp_timewait_state_process(struct inet_timewait_sock *tw, struct sk_buff *skb,
const struct tcphdr *th)
{
struct tcp_timewait_sock *tcptw = tcp_twsk((struct sock *)tw);
struct tcp_options_received tmp_opt;
int paws_reject = 0;
tmp_opt.saw_tstamp = 0;
if (th->doff > (sizeof(struct tcphdr) >> 2) && tw->tw_ts_recent_stamp) {
if (th->doff > (sizeof(*th) >> 2) && tcptw->tw_ts_recent_stamp) {
tcp_parse_options(skb, &tmp_opt, 0);
if (tmp_opt.saw_tstamp) {
tmp_opt.ts_recent = tw->tw_ts_recent;
tmp_opt.ts_recent_stamp = tw->tw_ts_recent_stamp;
tmp_opt.ts_recent = tcptw->tw_ts_recent;
tmp_opt.ts_recent_stamp = tcptw->tw_ts_recent_stamp;
paws_reject = tcp_paws_check(&tmp_opt, th->rst);
}
}
@@ -144,20 +145,20 @@ tcp_timewait_state_process(struct tcp_tw_bucket *tw, struct sk_buff *skb,
/* Out of window, send ACK */
if (paws_reject ||
!tcp_in_window(TCP_SKB_CB(skb)->seq, TCP_SKB_CB(skb)->end_seq,
tw->tw_rcv_nxt,
tw->tw_rcv_nxt + tw->tw_rcv_wnd))
tcptw->tw_rcv_nxt,
tcptw->tw_rcv_nxt + tcptw->tw_rcv_wnd))
return TCP_TW_ACK;
if (th->rst)
goto kill;
if (th->syn && !before(TCP_SKB_CB(skb)->seq, tw->tw_rcv_nxt))
if (th->syn && !before(TCP_SKB_CB(skb)->seq, tcptw->tw_rcv_nxt))
goto kill_with_rst;
/* Dup ACK? */
if (!after(TCP_SKB_CB(skb)->end_seq, tw->tw_rcv_nxt) ||
if (!after(TCP_SKB_CB(skb)->end_seq, tcptw->tw_rcv_nxt) ||
TCP_SKB_CB(skb)->end_seq == TCP_SKB_CB(skb)->seq) {
tcp_tw_put(tw);
inet_twsk_put(tw);
return TCP_TW_SUCCESS;
}
@@ -165,19 +166,19 @@ tcp_timewait_state_process(struct tcp_tw_bucket *tw, struct sk_buff *skb,
* reset.
*/
if (!th->fin ||
TCP_SKB_CB(skb)->end_seq != tw->tw_rcv_nxt + 1) {
TCP_SKB_CB(skb)->end_seq != tcptw->tw_rcv_nxt + 1) {
kill_with_rst:
tcp_tw_deschedule(tw);
tcp_tw_put(tw);
inet_twsk_put(tw);
return TCP_TW_RST;
}
/* FIN arrived, enter true time-wait state. */
tw->tw_substate = TCP_TIME_WAIT;
tw->tw_rcv_nxt = TCP_SKB_CB(skb)->end_seq;
tw->tw_substate = TCP_TIME_WAIT;
tcptw->tw_rcv_nxt = TCP_SKB_CB(skb)->end_seq;
if (tmp_opt.saw_tstamp) {
tw->tw_ts_recent_stamp = xtime.tv_sec;
tw->tw_ts_recent = tmp_opt.rcv_tsval;
tcptw->tw_ts_recent_stamp = xtime.tv_sec;
tcptw->tw_ts_recent = tmp_opt.rcv_tsval;
}
/* I am shamed, but failed to make it more elegant.
@@ -186,7 +187,7 @@ kill_with_rst:
* do not undertsnad recycling in any case, it not
* a big problem in practice. --ANK */
if (tw->tw_family == AF_INET &&
sysctl_tcp_tw_recycle && tw->tw_ts_recent_stamp &&
sysctl_tcp_tw_recycle && tcptw->tw_ts_recent_stamp &&
tcp_v4_tw_remember_stamp(tw))
tcp_tw_schedule(tw, tw->tw_timeout);
else
@@ -212,7 +213,7 @@ kill_with_rst:
*/
if (!paws_reject &&
(TCP_SKB_CB(skb)->seq == tw->tw_rcv_nxt &&
(TCP_SKB_CB(skb)->seq == tcptw->tw_rcv_nxt &&
(TCP_SKB_CB(skb)->seq == TCP_SKB_CB(skb)->end_seq || th->rst))) {
/* In window segment, it may be only reset or bare ack. */
@@ -224,18 +225,18 @@ kill_with_rst:
if (sysctl_tcp_rfc1337 == 0) {
kill:
tcp_tw_deschedule(tw);
tcp_tw_put(tw);
inet_twsk_put(tw);
return TCP_TW_SUCCESS;
}
}
tcp_tw_schedule(tw, TCP_TIMEWAIT_LEN);
if (tmp_opt.saw_tstamp) {
tw->tw_ts_recent = tmp_opt.rcv_tsval;
tw->tw_ts_recent_stamp = xtime.tv_sec;
tcptw->tw_ts_recent = tmp_opt.rcv_tsval;
tcptw->tw_ts_recent_stamp = xtime.tv_sec;
}
tcp_tw_put(tw);
inet_twsk_put(tw);
return TCP_TW_SUCCESS;
}
@@ -257,9 +258,10 @@ kill:
*/
if (th->syn && !th->rst && !th->ack && !paws_reject &&
(after(TCP_SKB_CB(skb)->seq, tw->tw_rcv_nxt) ||
(tmp_opt.saw_tstamp && (s32)(tw->tw_ts_recent - tmp_opt.rcv_tsval) < 0))) {
u32 isn = tw->tw_snd_nxt + 65535 + 2;
(after(TCP_SKB_CB(skb)->seq, tcptw->tw_rcv_nxt) ||
(tmp_opt.saw_tstamp &&
(s32)(tcptw->tw_ts_recent - tmp_opt.rcv_tsval) < 0))) {
u32 isn = tcptw->tw_snd_nxt + 65535 + 2;
if (isn == 0)
isn++;
TCP_SKB_CB(skb)->when = isn;
@@ -284,7 +286,7 @@ kill:
*/
return TCP_TW_ACK;
}
tcp_tw_put(tw);
inet_twsk_put(tw);
return TCP_TW_SUCCESS;
}
@@ -293,7 +295,7 @@ kill:
* relevant info into it from the SK, and mess with hash chains
* and list linkage.
*/
static void __tcp_tw_hashdance(struct sock *sk, struct tcp_tw_bucket *tw)
static void __tcp_tw_hashdance(struct sock *sk, struct inet_timewait_sock *tw)
{
const struct inet_sock *inet = inet_sk(sk);
struct inet_ehash_bucket *ehead = &tcp_hashinfo.ehash[sk->sk_hashent];
@@ -306,7 +308,7 @@ static void __tcp_tw_hashdance(struct sock *sk, struct tcp_tw_bucket *tw)
spin_lock(&bhead->lock);
tw->tw_tb = inet->bind_hash;
BUG_TRAP(inet->bind_hash);
tw_add_bind_node(tw, &tw->tw_tb->owners);
inet_twsk_add_bind_node(tw, &tw->tw_tb->owners);
spin_unlock(&bhead->lock);
write_lock(&ehead->lock);
@@ -316,7 +318,7 @@ static void __tcp_tw_hashdance(struct sock *sk, struct tcp_tw_bucket *tw)
sock_prot_dec_use(sk->sk_prot);
/* Step 3: Hash TW into TIMEWAIT half of established hash table. */
tw_add_node(tw, &(ehead + tcp_hashinfo.ehash_size)->chain);
inet_twsk_add_node(tw, &(ehead + tcp_hashinfo.ehash_size)->chain);
atomic_inc(&tw->tw_refcnt);
write_unlock(&ehead->lock);
@@ -327,19 +329,23 @@ static void __tcp_tw_hashdance(struct sock *sk, struct tcp_tw_bucket *tw)
*/
void tcp_time_wait(struct sock *sk, int state, int timeo)
{
struct tcp_tw_bucket *tw = NULL;
struct tcp_sock *tp = tcp_sk(sk);
struct inet_timewait_sock *tw = NULL;
const struct tcp_sock *tp = tcp_sk(sk);
int recycle_ok = 0;
if (sysctl_tcp_tw_recycle && tp->rx_opt.ts_recent_stamp)
recycle_ok = tp->af_specific->remember_stamp(sk);
if (tcp_tw_count < sysctl_tcp_max_tw_buckets)
tw = kmem_cache_alloc(tcp_timewait_cachep, SLAB_ATOMIC);
tw = kmem_cache_alloc(sk->sk_prot_creator->twsk_slab, SLAB_ATOMIC);
if(tw != NULL) {
struct inet_sock *inet = inet_sk(sk);
int rto = (tp->rto<<2) - (tp->rto>>1);
if (tw != NULL) {
struct tcp_timewait_sock *tcptw = tcp_twsk((struct sock *)tw);
const struct inet_sock *inet = inet_sk(sk);
const int rto = (tp->rto << 2) - (tp->rto >> 1);
/* Remember our protocol */
tw->tw_prot = sk->sk_prot_creator;
/* Give us an identity. */
tw->tw_daddr = inet->daddr;
@@ -356,25 +362,23 @@ void tcp_time_wait(struct sock *sk, int state, int timeo)
atomic_set(&tw->tw_refcnt, 1);
tw->tw_hashent = sk->sk_hashent;
tw->tw_rcv_nxt = tp->rcv_nxt;
tw->tw_snd_nxt = tp->snd_nxt;
tw->tw_rcv_wnd = tcp_receive_window(tp);
tw->tw_ts_recent = tp->rx_opt.ts_recent;
tw->tw_ts_recent_stamp = tp->rx_opt.ts_recent_stamp;
tw_dead_node_init(tw);
tcptw->tw_rcv_nxt = tp->rcv_nxt;
tcptw->tw_snd_nxt = tp->snd_nxt;
tcptw->tw_rcv_wnd = tcp_receive_window(tp);
tcptw->tw_ts_recent = tp->rx_opt.ts_recent;
tcptw->tw_ts_recent_stamp = tp->rx_opt.ts_recent_stamp;
inet_twsk_dead_node_init(tw);
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
if (tw->tw_family == PF_INET6) {
struct ipv6_pinfo *np = inet6_sk(sk);
struct tcp6_timewait_sock *tcp6tw = tcp6_twsk((struct sock *)tw);
ipv6_addr_copy(&tw->tw_v6_daddr, &np->daddr);
ipv6_addr_copy(&tw->tw_v6_rcv_saddr, &np->rcv_saddr);
tw->tw_v6_ipv6only = np->ipv6only;
} else {
memset(&tw->tw_v6_daddr, 0, sizeof(tw->tw_v6_daddr));
memset(&tw->tw_v6_rcv_saddr, 0, sizeof(tw->tw_v6_rcv_saddr));
tw->tw_v6_ipv6only = 0;
}
ipv6_addr_copy(&tcp6tw->tw_v6_daddr, &np->daddr);
ipv6_addr_copy(&tcp6tw->tw_v6_rcv_saddr, &np->rcv_saddr);
tw->tw_ipv6only = np->ipv6only;
} else
tw->tw_ipv6only = 0;
#endif
/* Linkage updates. */
__tcp_tw_hashdance(sk, tw);
@@ -392,7 +396,7 @@ void tcp_time_wait(struct sock *sk, int state, int timeo)
}
tcp_tw_schedule(tw, timeo);
tcp_tw_put(tw);
inet_twsk_put(tw);
} else {
/* Sorry, if we're out of memory, just CLOSE this
* socket up. We've got bigger problems than
@@ -427,7 +431,7 @@ static u32 twkill_thread_slots;
/* Returns non-zero if quota exceeded. */
static int tcp_do_twkill_work(int slot, unsigned int quota)
{
struct tcp_tw_bucket *tw;
struct inet_timewait_sock *tw;
struct hlist_node *node;
unsigned int killed;
int ret;
@@ -441,11 +445,11 @@ static int tcp_do_twkill_work(int slot, unsigned int quota)
killed = 0;
ret = 0;
rescan:
tw_for_each_inmate(tw, node, &tcp_tw_death_row[slot]) {
__tw_del_dead_node(tw);
inet_twsk_for_each_inmate(tw, node, &tcp_tw_death_row[slot]) {
__inet_twsk_del_dead_node(tw);
spin_unlock(&tw_death_lock);
tcp_timewait_kill(tw);
tcp_tw_put(tw);
inet_twsk_put(tw);
killed++;
spin_lock(&tw_death_lock);
if (killed > quota) {
@@ -531,11 +535,11 @@ static void twkill_work(void *dummy)
*/
/* This is for handling early-kills of TIME_WAIT sockets. */
void tcp_tw_deschedule(struct tcp_tw_bucket *tw)
void tcp_tw_deschedule(struct inet_timewait_sock *tw)
{
spin_lock(&tw_death_lock);
if (tw_del_dead_node(tw)) {
tcp_tw_put(tw);
if (inet_twsk_del_dead_node(tw)) {
inet_twsk_put(tw);
if (--tcp_tw_count == 0)
del_timer(&tcp_tw_timer);
}
@@ -552,7 +556,7 @@ static struct timer_list tcp_twcal_timer =
TIMER_INITIALIZER(tcp_twcal_tick, 0, 0);
static struct hlist_head tcp_twcal_row[TCP_TW_RECYCLE_SLOTS];
static void tcp_tw_schedule(struct tcp_tw_bucket *tw, int timeo)
static void tcp_tw_schedule(struct inet_timewait_sock *tw, const int timeo)
{
struct hlist_head *list;
int slot;
@@ -586,7 +590,7 @@ static void tcp_tw_schedule(struct tcp_tw_bucket *tw, int timeo)
spin_lock(&tw_death_lock);
/* Unlink it, if it was scheduled */
if (tw_del_dead_node(tw))
if (inet_twsk_del_dead_node(tw))
tcp_tw_count--;
else
atomic_inc(&tw->tw_refcnt);
@@ -644,13 +648,13 @@ void tcp_twcal_tick(unsigned long dummy)
for (n=0; n<TCP_TW_RECYCLE_SLOTS; n++) {
if (time_before_eq(j, now)) {
struct hlist_node *node, *safe;
struct tcp_tw_bucket *tw;
struct inet_timewait_sock *tw;
tw_for_each_inmate_safe(tw, node, safe,
&tcp_twcal_row[slot]) {
__tw_del_dead_node(tw);
inet_twsk_for_each_inmate_safe(tw, node, safe,
&tcp_twcal_row[slot]) {
__inet_twsk_del_dead_node(tw);
tcp_timewait_kill(tw);
tcp_tw_put(tw);
inet_twsk_put(tw);
killed++;
}
} else {