[INET]: Generalise tcp_tw_bucket, aka TIME_WAIT sockets
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>
diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c
index f29e2f6..5b5a493 100644
--- a/net/ipv4/tcp_minisocks.c
+++ b/net/ipv4/tcp_minisocks.c
@@ -41,7 +41,7 @@
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 @@
/* 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 @@
#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 @@
* 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 @@
/* 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 @@
* 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 @@
* 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 @@
*/
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 @@
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 @@
*/
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 @@
*/
return TCP_TW_ACK;
}
- tcp_tw_put(tw);
+ inet_twsk_put(tw);
return TCP_TW_SUCCESS;
}
@@ -293,7 +295,7 @@
* 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 @@
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 @@
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 @@
*/
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 @@
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 @@
}
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 @@
/* 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 @@
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 @@
*/
/* 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 @@
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 @@
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 @@
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 {