[DCCP]: Finish the TIMEWAIT minisock support

Using most of the infrastructure TCP uses, with a dccp_death_row,
etc. As per my current interpretation of the draft what we have with
this changeset seems to be all we need (or very close to it 8)).

Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 63 insertions, 15 deletions

diff --git a/include/linux/dccp.h b/include/linux/dccp.h
index 431d58923ba9..3dccdd5108b5 100644
--- a/include/linux/dccp.h
+++ b/include/linux/dccp.h
@@ -194,6 +194,7 @@ enum {
 #include <linux/workqueue.h>
 
 #include <net/inet_connection_sock.h>
+#include <net/inet_timewait_sock.h>
 #include <net/sock.h>
 #include <net/tcp_states.h>
 #include <net/tcp.h>
@@ -354,6 +355,8 @@ static inline struct dccp_request_sock *dccp_rsk(const struct request_sock *req)
         return (struct dccp_request_sock *)req;
 }
 
+extern struct inet_timewait_death_row dccp_death_row;
+
 /* Read about the ECN nonce to see why it is 253 */
 #define DCCP_MAX_ACK_VECTOR_LEN 253
 
diff --git a/net/dccp/ipv4.c b/net/dccp/ipv4.c
index 6bccf4dd1e70..f6da9328221e 100644
--- a/net/dccp/ipv4.c
+++ b/net/dccp/ipv4.c
@@ -97,7 +97,7 @@ static int __dccp_v4_check_established(struct sock *sk, const __u16 lport,
                 NET_INC_STATS_BH(LINUX_MIB_TIMEWAITRECYCLED);
         } else if (tw != NULL) {
                 /* Silly. Should hash-dance instead... */
-                dccp_tw_deschedule(tw);
+                inet_twsk_deschedule(tw, &dccp_death_row);
                 NET_INC_STATS_BH(LINUX_MIB_TIMEWAITRECYCLED);
 
                 inet_twsk_put(tw);
@@ -201,7 +201,7 @@ ok:
                 spin_unlock(&head->lock);
 
                 if (tw != NULL) {
-                        dccp_tw_deschedule(tw);
+                        inet_twsk_deschedule(tw, &dccp_death_row);
                         inet_twsk_put(tw);
                 }
 
@@ -1131,8 +1131,9 @@ int dccp_v4_rcv(struct sk_buff *skb)
          */
                
         if (sk->sk_state == DCCP_TIME_WAIT) {
-                dccp_pr_debug("sk->sk_state == DCCP_TIME_WAIT: discard_and_relse\n");
-                goto discard_and_relse;
+                dccp_pr_debug("sk->sk_state == DCCP_TIME_WAIT: "
+                              "do_time_wait\n");
+                goto do_time_wait;
         }
 
         if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb)) {
@@ -1179,6 +1180,10 @@ discard_it:
 discard_and_relse:
         sock_put(sk);
         goto discard_it;
+
+do_time_wait:
+        inet_twsk_put((struct inet_timewait_sock *)sk);
+        goto no_dccp_socket;
 }
 
 static int dccp_v4_init_sock(struct sock *sk)
@@ -1290,5 +1295,5 @@ struct proto dccp_v4_prot = {
         .max_header             = MAX_DCCP_HEADER,
         .obj_size               = sizeof(struct dccp_sock),
         .rsk_prot               = &dccp_request_sock_ops,
-        .twsk_obj_size          = sizeof(struct inet_timewait_sock), /* FIXME! create dccp_timewait_sock */
+        .twsk_obj_size          = sizeof(struct inet_timewait_sock),
 };
diff --git a/net/dccp/minisocks.c b/net/dccp/minisocks.c
index e498e389fccc..a6a0b270fb6c 100644
--- a/net/dccp/minisocks.c
+++ b/net/dccp/minisocks.c
@@ -22,18 +22,58 @@
 #include "ccid.h"
 #include "dccp.h"
 
+struct inet_timewait_death_row dccp_death_row = {
+        .sysctl_max_tw_buckets = NR_FILE * 2,
+        .period         = DCCP_TIMEWAIT_LEN / INET_TWDR_TWKILL_SLOTS,
+        .death_lock     = SPIN_LOCK_UNLOCKED,
+        .hashinfo       = &dccp_hashinfo,
+        .tw_timer       = TIMER_INITIALIZER(inet_twdr_hangman, 0,
+                                            (unsigned long)&dccp_death_row),
+        .twkill_work    = __WORK_INITIALIZER(dccp_death_row.twkill_work,
+                                             inet_twdr_twkill_work,
+                                             &dccp_death_row),
+/* Short-time timewait calendar */
+
+        .twcal_hand     = -1,
+        .twcal_timer    = TIMER_INITIALIZER(inet_twdr_twcal_tick, 0,
+                                            (unsigned long)&dccp_death_row),
+};
+
 void dccp_time_wait(struct sock *sk, int state, int timeo)
 {
-        /* FIXME: Implement */
-        dccp_pr_debug("Want to help? Start here\n");
-        dccp_set_state(sk, state);
-}
+        struct inet_timewait_sock *tw = NULL;
 
-/* This is for handling early-kills of TIME_WAIT sockets. */
-void dccp_tw_deschedule(struct inet_timewait_sock *tw)
-{
-        dccp_pr_debug("Want to help? Start here\n");
-        __inet_twsk_kill(tw, &dccp_hashinfo);
+        if (dccp_death_row.tw_count < dccp_death_row.sysctl_max_tw_buckets)
+                tw = inet_twsk_alloc(sk, state);
+
+        if (tw != NULL) {
+                const struct inet_connection_sock *icsk = inet_csk(sk);
+                const int rto = (icsk->icsk_rto << 2) - (icsk->icsk_rto >> 1);
+
+                /* Linkage updates. */
+                __inet_twsk_hashdance(tw, sk, &dccp_hashinfo);
+
+                /* Get the TIME_WAIT timeout firing. */
+                if (timeo < rto)
+                        timeo = rto;
+
+                tw->tw_timeout = DCCP_TIMEWAIT_LEN;
+                if (state == DCCP_TIME_WAIT)
+                        timeo = DCCP_TIMEWAIT_LEN;
+
+                inet_twsk_schedule(tw, &dccp_death_row, timeo,
+                                   DCCP_TIMEWAIT_LEN);
+                inet_twsk_put(tw);
+        } else {
+                /* Sorry, if we're out of memory, just CLOSE this
+                 * socket up.  We've got bigger problems than
+                 * non-graceful socket closings.
+                 */
+                if (net_ratelimit())
+                        printk(KERN_INFO "DCCP: time wait bucket table overflow\n");
+        }
+
+        dccp_done(sk);
 }
 
 struct sock *dccp_create_openreq_child(struct sock *sk,
@@ -55,7 +95,7 @@ struct sock *dccp_create_openreq_child(struct sock *sk,
 
                 newdp->dccps_hc_rx_ackpkts = NULL;
                 newdp->dccps_role = DCCP_ROLE_SERVER;
-                newicsk->icsk_rto = TCP_TIMEOUT_INIT;
+                newicsk->icsk_rto = DCCP_TIMEOUT_INIT;
 
                 if (newdp->dccps_options.dccpo_send_ack_vector) {
                         newdp->dccps_hc_rx_ackpkts = dccp_ackpkts_alloc(DCCP_MAX_ACK_VECTOR_LEN,