[DCCP] CCID: Improve CCID infrastructure

1. No need for ->ccid_init nor ->ccid_exit, this is what module_{init,exit}
   does and anynways neither ccid2 nor ccid3 were using it.

2. Rename struct ccid to struct ccid_operations and introduce struct ccid
   with a pointer to ccid_operations and rigth after it the rx or tx
   private state.

3. Remove the pointer to the state of the half connections from struct
   dccp_sock, now its derived thru ccid_priv() from the ccid pointer.

Now we also can implement the setsockopt for changing the CCID easily as
no ccid init routines can affect struct dccp_sock in any way that prevents
other CCIDs from working if a CCID switch operation is asked by apps.

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

10 files changed, 260 insertions, 212 deletions

diff --git a/include/linux/dccp.h b/include/linux/dccp.h
index a70d1a27e7fc..bdd756cc60b1 100644
--- a/include/linux/dccp.h
+++ b/include/linux/dccp.h
@@ -478,8 +478,6 @@ struct dccp_sock {
         __u32                           dccps_mss_cache;
         struct dccp_options             dccps_options;
         struct dccp_ackvec              *dccps_hc_rx_ackvec;
-        void                            *dccps_hc_rx_ccid_private;
-        void                            *dccps_hc_tx_ccid_private;
         struct ccid                     *dccps_hc_rx_ccid;
         struct ccid                     *dccps_hc_tx_ccid;
         struct dccp_options_received    dccps_options_received;
diff --git a/net/dccp/ccid.c b/net/dccp/ccid.c
index 06b191a5740b..ff05e59043cd 100644
--- a/net/dccp/ccid.c
+++ b/net/dccp/ccid.c
@@ -13,7 +13,7 @@
 
 #include "ccid.h"
 
-static struct ccid *ccids[CCID_MAX];
+static struct ccid_operations *ccids[CCID_MAX];
 #if defined(CONFIG_SMP) || defined(CONFIG_PREEMPT)
 static atomic_t ccids_lockct = ATOMIC_INIT(0);
 static DEFINE_SPINLOCK(ccids_lock);
@@ -55,82 +55,202 @@ static inline void ccids_read_unlock(void)
 #define ccids_read_unlock() do { } while(0)
 #endif
 
-int ccid_register(struct ccid *ccid)
+static kmem_cache_t *ccid_kmem_cache_create(int obj_size, const char *fmt,...)
 {
-        int err;
+        kmem_cache_t *slab;
+        char slab_name_fmt[32], *slab_name;
+        va_list args;
+
+        va_start(args, fmt);
+        vsnprintf(slab_name_fmt, sizeof(slab_name_fmt), fmt, args);
+        va_end(args);
+
+        slab_name = kstrdup(slab_name_fmt, GFP_KERNEL);
+        if (slab_name == NULL)
+                return NULL;
+        slab = kmem_cache_create(slab_name, sizeof(struct ccid) + obj_size, 0,
+                                 SLAB_HWCACHE_ALIGN, NULL, NULL);
+        if (slab == NULL)
+                kfree(slab_name);
+        return slab;
+}
+
+static void ccid_kmem_cache_destroy(kmem_cache_t *slab)
+{
+        if (slab != NULL) {
+                const char *name = kmem_cache_name(slab);
+
+                kmem_cache_destroy(slab);
+                kfree(name);
+        }
+}
+
+int ccid_register(struct ccid_operations *ccid_ops)
+{
+        int err = -ENOBUFS;
+
+        ccid_ops->ccid_hc_rx_slab =
+                        ccid_kmem_cache_create(ccid_ops->ccid_hc_rx_obj_size,
+                                               "%s_hc_rx_sock",
+                                               ccid_ops->ccid_name);
+        if (ccid_ops->ccid_hc_rx_slab == NULL)
+                goto out;
+
+        ccid_ops->ccid_hc_tx_slab =
+                        ccid_kmem_cache_create(ccid_ops->ccid_hc_tx_obj_size,
+                                               "%s_hc_tx_sock",
+                                               ccid_ops->ccid_name);
+        if (ccid_ops->ccid_hc_tx_slab == NULL)
+                goto out_free_rx_slab;
 
         ccids_write_lock();
         err = -EEXIST;
-        if (ccids[ccid->ccid_id] == NULL) {
-                ccids[ccid->ccid_id] = ccid;
+        if (ccids[ccid_ops->ccid_id] == NULL) {
+                ccids[ccid_ops->ccid_id] = ccid_ops;
                 err = 0;
         }
         ccids_write_unlock();
-        if (err == 0)
-                pr_info("CCID: Registered CCID %d (%s)\n",
-                        ccid->ccid_id, ccid->ccid_name);
+        if (err != 0)
+                goto out_free_tx_slab;
+
+        pr_info("CCID: Registered CCID %d (%s)\n",
+                ccid_ops->ccid_id, ccid_ops->ccid_name);
+out:
         return err;
+out_free_tx_slab:
+        ccid_kmem_cache_destroy(ccid_ops->ccid_hc_tx_slab);
+        ccid_ops->ccid_hc_tx_slab = NULL;
+        goto out;
+out_free_rx_slab:
+        ccid_kmem_cache_destroy(ccid_ops->ccid_hc_rx_slab);
+        ccid_ops->ccid_hc_rx_slab = NULL;
+        goto out;
 }
 
 EXPORT_SYMBOL_GPL(ccid_register);
 
-int ccid_unregister(struct ccid *ccid)
+int ccid_unregister(struct ccid_operations *ccid_ops)
 {
         ccids_write_lock();
-        ccids[ccid->ccid_id] = NULL;
+        ccids[ccid_ops->ccid_id] = NULL;
         ccids_write_unlock();
+
+        ccid_kmem_cache_destroy(ccid_ops->ccid_hc_tx_slab);
+        ccid_ops->ccid_hc_tx_slab = NULL;
+        ccid_kmem_cache_destroy(ccid_ops->ccid_hc_rx_slab);
+        ccid_ops->ccid_hc_rx_slab = NULL;
+
         pr_info("CCID: Unregistered CCID %d (%s)\n",
-                ccid->ccid_id, ccid->ccid_name);
+                ccid_ops->ccid_id, ccid_ops->ccid_name);
         return 0;
 }
 
 EXPORT_SYMBOL_GPL(ccid_unregister);
 
-struct ccid *ccid_init(unsigned char id, struct sock *sk)
+struct ccid *ccid_new(unsigned char id, struct sock *sk, int rx, gfp_t gfp)
 {
-        struct ccid *ccid;
+        struct ccid_operations *ccid_ops;
+        struct ccid *ccid = NULL;
 
+        ccids_read_lock();
 #ifdef CONFIG_KMOD
-        if (ccids[id] == NULL)
+        if (ccids[id] == NULL) {
+                /* We only try to load if in process context */
+                ccids_read_unlock();
+                if (gfp & GFP_ATOMIC)
+                        goto out;
                 request_module("net-dccp-ccid-%d", id);
+                ccids_read_lock();
+        }
 #endif
-        ccids_read_lock();
+        ccid_ops = ccids[id];
+        if (ccid_ops == NULL)
+                goto out_unlock;
 
-        ccid = ccids[id];
-        if (ccid == NULL)
-                goto out;
+        if (!try_module_get(ccid_ops->ccid_owner))
+                goto out_unlock;
 
-        if (!try_module_get(ccid->ccid_owner))
-                goto out_err;
+        ccids_read_unlock();
 
-        if (ccid->ccid_init != NULL && ccid->ccid_init(sk) != 0)
+        ccid = kmem_cache_alloc(rx ? ccid_ops->ccid_hc_rx_slab :
+                                     ccid_ops->ccid_hc_tx_slab, gfp);
+        if (ccid == NULL)
                 goto out_module_put;
+        ccid->ccid_ops = ccid_ops;
+        if (rx) {
+                memset(ccid + 1, 0, ccid_ops->ccid_hc_rx_obj_size);
+                if (ccid->ccid_ops->ccid_hc_rx_init != NULL &&
+                    ccid->ccid_ops->ccid_hc_rx_init(ccid, sk) != 0)
+                        goto out_free_ccid;
+        } else {
+                memset(ccid + 1, 0, ccid_ops->ccid_hc_tx_obj_size);
+                if (ccid->ccid_ops->ccid_hc_tx_init != NULL &&
+                    ccid->ccid_ops->ccid_hc_tx_init(ccid, sk) != 0)
+                        goto out_free_ccid;
+        }
 out:
-        ccids_read_unlock();
         return ccid;
-out_module_put:
-        module_put(ccid->ccid_owner);
-out_err:
+out_unlock:
+        ccids_read_unlock();
+        goto out;
+out_free_ccid:
+        kmem_cache_free(rx ? ccid_ops->ccid_hc_rx_slab :
+                        ccid_ops->ccid_hc_tx_slab, ccid);
         ccid = NULL;
+out_module_put:
+        module_put(ccid_ops->ccid_owner);
         goto out;
 }
 
-EXPORT_SYMBOL_GPL(ccid_init);
+EXPORT_SYMBOL_GPL(ccid_new);
 
-void ccid_exit(struct ccid *ccid, struct sock *sk)
+struct ccid *ccid_hc_rx_new(unsigned char id, struct sock *sk, gfp_t gfp)
 {
+        return ccid_new(id, sk, 1, gfp);
+}
+
+EXPORT_SYMBOL_GPL(ccid_hc_rx_new);
+
+struct ccid *ccid_hc_tx_new(unsigned char id,struct sock *sk,  gfp_t gfp)
+{
+        return ccid_new(id, sk, 0, gfp);
+}
+
+EXPORT_SYMBOL_GPL(ccid_hc_tx_new);
+
+static void ccid_delete(struct ccid *ccid, struct sock *sk, int rx)
+{
+        struct ccid_operations *ccid_ops;
+
         if (ccid == NULL)
                 return;
 
+        ccid_ops = ccid->ccid_ops;
+        if (rx) {
+                if (ccid_ops->ccid_hc_rx_exit != NULL)
+                        ccid_ops->ccid_hc_rx_exit(sk);
+                kmem_cache_free(ccid_ops->ccid_hc_rx_slab,  ccid);
+        } else {
+                if (ccid_ops->ccid_hc_tx_exit != NULL)
+                        ccid_ops->ccid_hc_tx_exit(sk);
+                kmem_cache_free(ccid_ops->ccid_hc_tx_slab,  ccid);
+        }
         ccids_read_lock();
+        if (ccids[ccid_ops->ccid_id] != NULL)
+                module_put(ccid_ops->ccid_owner);
+        ccids_read_unlock();
+}
 
-        if (ccids[ccid->ccid_id] != NULL) {
-                if (ccid->ccid_exit != NULL)
-                        ccid->ccid_exit(sk);
-                module_put(ccid->ccid_owner);
-        }
+void ccid_hc_rx_delete(struct ccid *ccid, struct sock *sk)
+{
+        ccid_delete(ccid, sk, 1);
+}
 
-        ccids_read_unlock();
+EXPORT_SYMBOL_GPL(ccid_hc_rx_delete);
+
+void ccid_hc_tx_delete(struct ccid *ccid, struct sock *sk)
+{
+        ccid_delete(ccid, sk, 0);
 }
 
-EXPORT_SYMBOL_GPL(ccid_exit);
+EXPORT_SYMBOL_GPL(ccid_hc_tx_delete);
diff --git a/net/dccp/ccid.h b/net/dccp/ccid.h
index de681c6ad081..3dec50d49731 100644
--- a/net/dccp/ccid.h
+++ b/net/dccp/ccid.h
@@ -23,14 +23,16 @@
 
 struct tcp_info;
 
-struct ccid {
+struct ccid_operations {
         unsigned char   ccid_id;
         const char      *ccid_name;
         struct module   *ccid_owner;
-        int             (*ccid_init)(struct sock *sk);
-        void            (*ccid_exit)(struct sock *sk);
-        int             (*ccid_hc_rx_init)(struct sock *sk);
-        int             (*ccid_hc_tx_init)(struct sock *sk);
+        kmem_cache_t    *ccid_hc_rx_slab;
+        __u32           ccid_hc_rx_obj_size;
+        kmem_cache_t    *ccid_hc_tx_slab;
+        __u32           ccid_hc_tx_obj_size;
+        int             (*ccid_hc_rx_init)(struct ccid *ccid, struct sock *sk);
+        int             (*ccid_hc_tx_init)(struct ccid *ccid, struct sock *sk);
         void            (*ccid_hc_rx_exit)(struct sock *sk);
         void            (*ccid_hc_tx_exit)(struct sock *sk);
         void            (*ccid_hc_rx_packet_recv)(struct sock *sk,
@@ -67,75 +69,58 @@ struct ccid {
                                                  int __user *optlen);
 };
 
-extern int         ccid_register(struct ccid *ccid);
-extern int         ccid_unregister(struct ccid *ccid);
+extern int ccid_register(struct ccid_operations *ccid_ops);
+extern int ccid_unregister(struct ccid_operations *ccid_ops);
 
-extern struct ccid *ccid_init(unsigned char id, struct sock *sk);
-extern void        ccid_exit(struct ccid *ccid, struct sock *sk);
+struct ccid {
+        struct ccid_operations *ccid_ops;
+        char                   ccid_priv[0];
+};
 
-static inline void __ccid_get(struct ccid *ccid)
+static inline void *ccid_priv(const struct ccid *ccid)
 {
-        __module_get(ccid->ccid_owner);
+        return (void *)ccid->ccid_priv;
 }
 
+extern struct ccid *ccid_new(unsigned char id, struct sock *sk, int rx,
+                             gfp_t gfp);
+
+extern struct ccid *ccid_hc_rx_new(unsigned char id, struct sock *sk,
+                                   gfp_t gfp);
+extern struct ccid *ccid_hc_tx_new(unsigned char id, struct sock *sk,
+                                   gfp_t gfp);
+
+extern void ccid_hc_rx_delete(struct ccid *ccid, struct sock *sk);
+extern void ccid_hc_tx_delete(struct ccid *ccid, struct sock *sk);
+
 static inline int ccid_hc_tx_send_packet(struct ccid *ccid, struct sock *sk,
                                          struct sk_buff *skb, int len)
 {
         int rc = 0;
-        if (ccid->ccid_hc_tx_send_packet != NULL)
-                rc = ccid->ccid_hc_tx_send_packet(sk, skb, len);
+        if (ccid->ccid_ops->ccid_hc_tx_send_packet != NULL)
+                rc = ccid->ccid_ops->ccid_hc_tx_send_packet(sk, skb, len);
         return rc;
 }
 
 static inline void ccid_hc_tx_packet_sent(struct ccid *ccid, struct sock *sk,
                                           int more, int len)
 {
-        if (ccid->ccid_hc_tx_packet_sent != NULL)
-                ccid->ccid_hc_tx_packet_sent(sk, more, len);
-}
-
-static inline int ccid_hc_rx_init(struct ccid *ccid, struct sock *sk)
-{
-        int rc = 0;
-        if (ccid->ccid_hc_rx_init != NULL)
-                rc = ccid->ccid_hc_rx_init(sk);
-        return rc;
-}
-
-static inline int ccid_hc_tx_init(struct ccid *ccid, struct sock *sk)
-{
-        int rc = 0;
-        if (ccid->ccid_hc_tx_init != NULL)
-                rc = ccid->ccid_hc_tx_init(sk);
-        return rc;
-}
-
-static inline void ccid_hc_rx_exit(struct ccid *ccid, struct sock *sk)
-{
-        if (ccid != NULL && ccid->ccid_hc_rx_exit != NULL &&
-            dccp_sk(sk)->dccps_hc_rx_ccid_private != NULL)
-                ccid->ccid_hc_rx_exit(sk);
-}
-
-static inline void ccid_hc_tx_exit(struct ccid *ccid, struct sock *sk)
-{
-        if (ccid != NULL && ccid->ccid_hc_tx_exit != NULL &&
-            dccp_sk(sk)->dccps_hc_tx_ccid_private != NULL)
-                ccid->ccid_hc_tx_exit(sk);
+        if (ccid->ccid_ops->ccid_hc_tx_packet_sent != NULL)
+                ccid->ccid_ops->ccid_hc_tx_packet_sent(sk, more, len);
 }
 
 static inline void ccid_hc_rx_packet_recv(struct ccid *ccid, struct sock *sk,
                                           struct sk_buff *skb)
 {
-        if (ccid->ccid_hc_rx_packet_recv != NULL)
-                ccid->ccid_hc_rx_packet_recv(sk, skb);
+        if (ccid->ccid_ops->ccid_hc_rx_packet_recv != NULL)
+                ccid->ccid_ops->ccid_hc_rx_packet_recv(sk, skb);
 }
 
 static inline void ccid_hc_tx_packet_recv(struct ccid *ccid, struct sock *sk,
                                           struct sk_buff *skb)
 {
-        if (ccid->ccid_hc_tx_packet_recv != NULL)
-                ccid->ccid_hc_tx_packet_recv(sk, skb);
+        if (ccid->ccid_ops->ccid_hc_tx_packet_recv != NULL)
+                ccid->ccid_ops->ccid_hc_tx_packet_recv(sk, skb);
 }
 
 static inline int ccid_hc_tx_parse_options(struct ccid *ccid, struct sock *sk,
@@ -144,8 +129,8 @@ static inline int ccid_hc_tx_parse_options(struct ccid *ccid, struct sock *sk,
                                            unsigned char* value)
 {
         int rc = 0;
-        if (ccid->ccid_hc_tx_parse_options != NULL)
-                rc = ccid->ccid_hc_tx_parse_options(sk, option, len, idx,
+        if (ccid->ccid_ops->ccid_hc_tx_parse_options != NULL)
+                rc = ccid->ccid_ops->ccid_hc_tx_parse_options(sk, option, len, idx,
                                                     value);
         return rc;
 }
@@ -156,37 +141,37 @@ static inline int ccid_hc_rx_parse_options(struct ccid *ccid, struct sock *sk,
                                            unsigned char* value)
 {
         int rc = 0;
-        if (ccid->ccid_hc_rx_parse_options != NULL)
-                rc = ccid->ccid_hc_rx_parse_options(sk, option, len, idx, value);
+        if (ccid->ccid_ops->ccid_hc_rx_parse_options != NULL)
+                rc = ccid->ccid_ops->ccid_hc_rx_parse_options(sk, option, len, idx, value);
         return rc;
 }
 
 static inline void ccid_hc_tx_insert_options(struct ccid *ccid, struct sock *sk,
                                              struct sk_buff *skb)
 {
-        if (ccid->ccid_hc_tx_insert_options != NULL)
-                ccid->ccid_hc_tx_insert_options(sk, skb);
+        if (ccid->ccid_ops->ccid_hc_tx_insert_options != NULL)
+                ccid->ccid_ops->ccid_hc_tx_insert_options(sk, skb);
 }
 
 static inline void ccid_hc_rx_insert_options(struct ccid *ccid, struct sock *sk,
                                              struct sk_buff *skb)
 {
-        if (ccid->ccid_hc_rx_insert_options != NULL)
-                ccid->ccid_hc_rx_insert_options(sk, skb);
+        if (ccid->ccid_ops->ccid_hc_rx_insert_options != NULL)
+                ccid->ccid_ops->ccid_hc_rx_insert_options(sk, skb);
 }
 
 static inline void ccid_hc_rx_get_info(struct ccid *ccid, struct sock *sk,
                                        struct tcp_info *info)
 {
-        if (ccid->ccid_hc_rx_get_info != NULL)
-                ccid->ccid_hc_rx_get_info(sk, info);
+        if (ccid->ccid_ops->ccid_hc_rx_get_info != NULL)
+                ccid->ccid_ops->ccid_hc_rx_get_info(sk, info);
 }
 
 static inline void ccid_hc_tx_get_info(struct ccid *ccid, struct sock *sk,
                                        struct tcp_info *info)
 {
-        if (ccid->ccid_hc_tx_get_info != NULL)
-                ccid->ccid_hc_tx_get_info(sk, info);
+        if (ccid->ccid_ops->ccid_hc_tx_get_info != NULL)
+                ccid->ccid_ops->ccid_hc_tx_get_info(sk, info);
 }
 
 static inline int ccid_hc_rx_getsockopt(struct ccid *ccid, struct sock *sk,
@@ -194,8 +179,8 @@ static inline int ccid_hc_rx_getsockopt(struct ccid *ccid, struct sock *sk,
                                         u32 __user *optval, int __user *optlen)
 {
         int rc = -ENOPROTOOPT;
-        if (ccid->ccid_hc_rx_getsockopt != NULL)
-                rc = ccid->ccid_hc_rx_getsockopt(sk, optname, len,
+        if (ccid->ccid_ops->ccid_hc_rx_getsockopt != NULL)
+                rc = ccid->ccid_ops->ccid_hc_rx_getsockopt(sk, optname, len,
                                                  optval, optlen);
         return rc;
 }
@@ -205,8 +190,8 @@ static inline int ccid_hc_tx_getsockopt(struct ccid *ccid, struct sock *sk,
                                         u32 __user *optval, int __user *optlen)
 {
         int rc = -ENOPROTOOPT;
-        if (ccid->ccid_hc_tx_getsockopt != NULL)
-                rc = ccid->ccid_hc_tx_getsockopt(sk, optname, len,
+        if (ccid->ccid_ops->ccid_hc_tx_getsockopt != NULL)
+                rc = ccid->ccid_ops->ccid_hc_tx_getsockopt(sk, optname, len,
                                                  optval, optlen);
         return rc;
 }
diff --git a/net/dccp/ccids/ccid2.c b/net/dccp/ccids/ccid2.c
index 3328d23c4be7..b40c4569a820 100644
--- a/net/dccp/ccids/ccid2.c
+++ b/net/dccp/ccids/ccid2.c
@@ -52,16 +52,6 @@ static int ccid2_debug;
 
 static const int ccid2_seq_len = 128;
 
-static inline struct ccid2_hc_tx_sock *ccid2_hc_tx_sk(const struct sock *sk)
-{
-        return dccp_sk(sk)->dccps_hc_tx_ccid_private;
-}
-
-static inline struct ccid2_hc_rx_sock *ccid2_hc_rx_sk(const struct sock *sk)
-{
-        return dccp_sk(sk)->dccps_hc_rx_ccid_private;
-}
-
 #ifdef CCID2_DEBUG
 static void ccid2_hc_tx_check_sanity(const struct ccid2_hc_tx_sock *hctx)
 {
@@ -707,19 +697,12 @@ static void ccid2_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb)
         ccid2_hc_tx_check_sanity(hctx);
 }
 
-static int ccid2_hc_tx_init(struct sock *sk)
+static int ccid2_hc_tx_init(struct ccid *ccid, struct sock *sk)
 {
-        struct dccp_sock *dp = dccp_sk(sk);
-        struct ccid2_hc_tx_sock *hctx;
+        struct ccid2_hc_tx_sock *hctx = ccid_priv(ccid);
         int seqcount = ccid2_seq_len;
         int i;
 
-        dp->dccps_hc_tx_ccid_private = kzalloc(sizeof(*hctx), gfp_any());
-        if (dp->dccps_hc_tx_ccid_private == NULL)
-                return -ENOMEM;
-
-        hctx = ccid2_hc_tx_sk(sk);
-
         /* XXX init variables with proper values */
         hctx->ccid2hctx_cwnd      = 1;
         hctx->ccid2hctx_ssthresh  = 10;
@@ -728,11 +711,9 @@ static int ccid2_hc_tx_init(struct sock *sk)
         /* XXX init ~ to window size... */
         hctx->ccid2hctx_seqbuf = kmalloc(sizeof(*hctx->ccid2hctx_seqbuf) *
                                          seqcount, gfp_any());
-        if (hctx->ccid2hctx_seqbuf == NULL) {
-                kfree(dp->dccps_hc_tx_ccid_private);
-                dp->dccps_hc_tx_ccid_private = NULL;
+        if (hctx->ccid2hctx_seqbuf == NULL)
                 return -ENOMEM;
-        }
+
         for (i = 0; i < (seqcount - 1); i++) {
                 hctx->ccid2hctx_seqbuf[i].ccid2s_next =
                                         &hctx->ccid2hctx_seqbuf[i + 1];
@@ -763,15 +744,11 @@ static int ccid2_hc_tx_init(struct sock *sk)
 
 static void ccid2_hc_tx_exit(struct sock *sk)
 {
-        struct dccp_sock *dp = dccp_sk(sk);
         struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk);
 
         ccid2_hc_tx_kill_rto_timer(sk);
-
         kfree(hctx->ccid2hctx_seqbuf);
-
-        kfree(dp->dccps_hc_tx_ccid_private);
-        dp->dccps_hc_tx_ccid_private = NULL;
+        hctx->ccid2hctx_seqbuf = NULL;
 }
 
 static void ccid2_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb)
@@ -791,33 +768,17 @@ static void ccid2_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb)
         }
 }
 
-static int ccid2_hc_rx_init(struct sock *sk)
-{
-        struct dccp_sock *dp = dccp_sk(sk);
-        dp->dccps_hc_rx_ccid_private = kzalloc(sizeof(struct ccid2_hc_rx_sock),
-                                               gfp_any());
-        return dp->dccps_hc_rx_ccid_private == NULL ? -ENOMEM : 0;
-}
-
-static void ccid2_hc_rx_exit(struct sock *sk)
-{
-        struct dccp_sock *dp = dccp_sk(sk);
-
-        kfree(dp->dccps_hc_rx_ccid_private);
-        dp->dccps_hc_rx_ccid_private = NULL;
-}
-
-static struct ccid ccid2 = {
+static struct ccid_operations ccid2 = {
         .ccid_id                = 2,
         .ccid_name              = "ccid2",
         .ccid_owner             = THIS_MODULE,
+        .ccid_hc_tx_obj_size    = sizeof(struct ccid2_hc_tx_sock),
         .ccid_hc_tx_init        = ccid2_hc_tx_init,
         .ccid_hc_tx_exit        = ccid2_hc_tx_exit,
         .ccid_hc_tx_send_packet = ccid2_hc_tx_send_packet,
         .ccid_hc_tx_packet_sent = ccid2_hc_tx_packet_sent,
         .ccid_hc_tx_packet_recv = ccid2_hc_tx_packet_recv,
-        .ccid_hc_rx_init        = ccid2_hc_rx_init,
-        .ccid_hc_rx_exit        = ccid2_hc_rx_exit,
+        .ccid_hc_rx_obj_size    = sizeof(struct ccid2_hc_rx_sock),
         .ccid_hc_rx_packet_recv = ccid2_hc_rx_packet_recv,
 };
 
diff --git a/net/dccp/ccids/ccid2.h b/net/dccp/ccids/ccid2.h
index 0b08c90955a9..451a87464fa5 100644
--- a/net/dccp/ccids/ccid2.h
+++ b/net/dccp/ccids/ccid2.h
@@ -20,6 +20,13 @@
 #ifndef _DCCP_CCID2_H_
 #define _DCCP_CCID2_H_
 
+#include <linux/dccp.h>
+#include <linux/timer.h>
+#include <linux/types.h>
+#include "../ccid.h"
+
+struct sock;
+
 struct ccid2_seq {
         u64                     ccid2s_seq;
         unsigned long           ccid2s_sent;
@@ -66,4 +73,13 @@ struct ccid2_hc_rx_sock {
         int     ccid2hcrx_data;
 };
 
+static inline struct ccid2_hc_tx_sock *ccid2_hc_tx_sk(const struct sock *sk)
+{
+        return ccid_priv(dccp_sk(sk)->dccps_hc_tx_ccid);
+}
+
+static inline struct ccid2_hc_rx_sock *ccid2_hc_rx_sk(const struct sock *sk)
+{
+        return ccid_priv(dccp_sk(sk)->dccps_hc_rx_ccid);
+}
 #endif /* _DCCP_CCID2_H_ */
diff --git a/net/dccp/ccids/ccid3.c b/net/dccp/ccids/ccid3.c
index f9e16db09bef..0587f52e4af1 100644
--- a/net/dccp/ccids/ccid3.c
+++ b/net/dccp/ccids/ccid3.c
@@ -647,17 +647,10 @@ static int ccid3_hc_tx_parse_options(struct sock *sk, unsigned char option,
         return rc;
 }
 
-static int ccid3_hc_tx_init(struct sock *sk)
+static int ccid3_hc_tx_init(struct ccid *ccid, struct sock *sk)
 {
         struct dccp_sock *dp = dccp_sk(sk);
-        struct ccid3_hc_tx_sock *hctx;
-
-        dp->dccps_hc_tx_ccid_private = kmalloc(sizeof(*hctx), gfp_any());
-        if (dp->dccps_hc_tx_ccid_private == NULL)
-                return -ENOMEM;
-
-        hctx = ccid3_hc_tx_sk(sk);
-        memset(hctx, 0, sizeof(*hctx));
+        struct ccid3_hc_tx_sock *hctx = ccid_priv(ccid);
 
         if (dp->dccps_packet_size >= TFRC_MIN_PACKET_SIZE &&
             dp->dccps_packet_size <= TFRC_MAX_PACKET_SIZE)
@@ -680,7 +673,6 @@ static int ccid3_hc_tx_init(struct sock *sk)
 
 static void ccid3_hc_tx_exit(struct sock *sk)
 {
-        struct dccp_sock *dp = dccp_sk(sk);
         struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
 
         BUG_ON(hctx == NULL);
@@ -690,9 +682,6 @@ static void ccid3_hc_tx_exit(struct sock *sk)
 
         /* Empty packet history */
         dccp_tx_hist_purge(ccid3_tx_hist, &hctx->ccid3hctx_hist);
-
-        kfree(dp->dccps_hc_tx_ccid_private);
-        dp->dccps_hc_tx_ccid_private = NULL;
 }
 
 /*
@@ -1039,20 +1028,13 @@ static void ccid3_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb)
         }
 }
 
-static int ccid3_hc_rx_init(struct sock *sk)
+static int ccid3_hc_rx_init(struct ccid *ccid, struct sock *sk)
 {
         struct dccp_sock *dp = dccp_sk(sk);
-        struct ccid3_hc_rx_sock *hcrx;
+        struct ccid3_hc_rx_sock *hcrx = ccid_priv(ccid);
 
         ccid3_pr_debug("%s, sk=%p\n", dccp_role(sk), sk);
 
-        dp->dccps_hc_rx_ccid_private = kmalloc(sizeof(*hcrx), gfp_any());
-        if (dp->dccps_hc_rx_ccid_private == NULL)
-                return -ENOMEM;
-
-        hcrx = ccid3_hc_rx_sk(sk);
-        memset(hcrx, 0, sizeof(*hcrx));
-
         if (dp->dccps_packet_size >= TFRC_MIN_PACKET_SIZE &&
             dp->dccps_packet_size <= TFRC_MAX_PACKET_SIZE)
                 hcrx->ccid3hcrx_s = dp->dccps_packet_size;
@@ -1071,7 +1053,6 @@ static int ccid3_hc_rx_init(struct sock *sk)
 static void ccid3_hc_rx_exit(struct sock *sk)
 {
         struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
-        struct dccp_sock *dp = dccp_sk(sk);
 
         BUG_ON(hcrx == NULL);
 
@@ -1082,9 +1063,6 @@ static void ccid3_hc_rx_exit(struct sock *sk)
 
         /* Empty loss interval history */
         dccp_li_hist_purge(ccid3_li_hist, &hcrx->ccid3hcrx_li_hist);
-
-        kfree(dp->dccps_hc_rx_ccid_private);
-        dp->dccps_hc_rx_ccid_private = NULL;
 }
 
 static void ccid3_hc_rx_get_info(struct sock *sk, struct tcp_info *info)
@@ -1170,10 +1148,11 @@ static int ccid3_hc_tx_getsockopt(struct sock *sk, const int optname, int len,
         return 0;
 }
 
-static struct ccid ccid3 = {
+static struct ccid_operations ccid3 = {
         .ccid_id                   = 3,
         .ccid_name                 = "ccid3",
         .ccid_owner                = THIS_MODULE,
+        .ccid_hc_tx_obj_size       = sizeof(struct ccid3_hc_tx_sock),
         .ccid_hc_tx_init           = ccid3_hc_tx_init,
         .ccid_hc_tx_exit           = ccid3_hc_tx_exit,
         .ccid_hc_tx_send_packet    = ccid3_hc_tx_send_packet,
@@ -1181,6 +1160,7 @@ static struct ccid ccid3 = {
         .ccid_hc_tx_packet_recv    = ccid3_hc_tx_packet_recv,
         .ccid_hc_tx_insert_options = ccid3_hc_tx_insert_options,
         .ccid_hc_tx_parse_options  = ccid3_hc_tx_parse_options,
+        .ccid_hc_rx_obj_size       = sizeof(struct ccid3_hc_rx_sock),
         .ccid_hc_rx_init           = ccid3_hc_rx_init,
         .ccid_hc_rx_exit           = ccid3_hc_rx_exit,
         .ccid_hc_rx_insert_options = ccid3_hc_rx_insert_options,
diff --git a/net/dccp/ccids/ccid3.h b/net/dccp/ccids/ccid3.h
index 0bde4583d091..f18b96d4e5a2 100644
--- a/net/dccp/ccids/ccid3.h
+++ b/net/dccp/ccids/ccid3.h
@@ -41,6 +41,7 @@
 #include <linux/time.h>
 #include <linux/types.h>
 #include <linux/tfrc.h>
+#include "../ccid.h"
 
 #define TFRC_MIN_PACKET_SIZE       16
 #define TFRC_STD_PACKET_SIZE      256
@@ -135,12 +136,12 @@ struct ccid3_hc_rx_sock {
 
 static inline struct ccid3_hc_tx_sock *ccid3_hc_tx_sk(const struct sock *sk)
 {
-    return dccp_sk(sk)->dccps_hc_tx_ccid_private;
+    return ccid_priv(dccp_sk(sk)->dccps_hc_tx_ccid);
 }
 
 static inline struct ccid3_hc_rx_sock *ccid3_hc_rx_sk(const struct sock *sk)
 {
-    return dccp_sk(sk)->dccps_hc_rx_ccid_private;
+    return ccid_priv(dccp_sk(sk)->dccps_hc_rx_ccid);
 }
 
 #endif /* _DCCP_CCID3_H_ */
diff --git a/net/dccp/input.c b/net/dccp/input.c
index 4b6d43d8b920..67691a0592af 100644
--- a/net/dccp/input.c
+++ b/net/dccp/input.c
@@ -324,14 +324,6 @@ static int dccp_rcv_request_sent_state_process(struct sock *sk,
                 dccp_set_seqno(&dp->dccps_swl,
                                max48(dp->dccps_swl, dp->dccps_isr));
 
-                if (ccid_hc_rx_init(dp->dccps_hc_rx_ccid, sk) != 0 ||
-                    ccid_hc_tx_init(dp->dccps_hc_tx_ccid, sk) != 0) {
-                        ccid_hc_rx_exit(dp->dccps_hc_rx_ccid, sk);
-                        ccid_hc_tx_exit(dp->dccps_hc_tx_ccid, sk);
-                        /* FIXME: send appropriate RESET code */
-                        goto out_invalid_packet;
-                }
-
                 dccp_sync_mss(sk, icsk->icsk_pmtu_cookie);
 
                 /*
diff --git a/net/dccp/ipv4.c b/net/dccp/ipv4.c
index fcfb486f90c2..aa7708fed32e 100644
--- a/net/dccp/ipv4.c
+++ b/net/dccp/ipv4.c
@@ -1058,14 +1058,16 @@ int dccp_v4_init_sock(struct sock *sk)
                         if (dp->dccps_hc_rx_ackvec == NULL)
                                 return -ENOMEM;
                 }
-                dp->dccps_hc_rx_ccid = ccid_init(dp->dccps_options.dccpo_rx_ccid,
-                                                 sk);
-                dp->dccps_hc_tx_ccid = ccid_init(dp->dccps_options.dccpo_tx_ccid,
-                                                 sk);
-                if (dp->dccps_hc_rx_ccid == NULL ||
-                    dp->dccps_hc_tx_ccid == NULL) {
-                        ccid_exit(dp->dccps_hc_rx_ccid, sk);
-                        ccid_exit(dp->dccps_hc_tx_ccid, sk);
+                dp->dccps_hc_rx_ccid =
+                                ccid_hc_rx_new(dp->dccps_options.dccpo_rx_ccid,
+                                               sk, GFP_KERNEL);
+                dp->dccps_hc_tx_ccid =
+                                ccid_hc_tx_new(dp->dccps_options.dccpo_tx_ccid,
+                                               sk, GFP_KERNEL);
+                if (unlikely(dp->dccps_hc_rx_ccid == NULL ||
+                             dp->dccps_hc_tx_ccid == NULL)) {
+                        ccid_hc_rx_delete(dp->dccps_hc_rx_ccid, sk);
+                        ccid_hc_tx_delete(dp->dccps_hc_tx_ccid, sk);
                         if (dp->dccps_options.dccpo_send_ack_vector) {
                                 dccp_ackvec_free(dp->dccps_hc_rx_ackvec);
                                 dp->dccps_hc_rx_ackvec = NULL;
@@ -1120,14 +1122,12 @@ int dccp_v4_destroy_sock(struct sock *sk)
         kfree(dp->dccps_service_list);
         dp->dccps_service_list = NULL;
 
-        ccid_hc_rx_exit(dp->dccps_hc_rx_ccid, sk);
-        ccid_hc_tx_exit(dp->dccps_hc_tx_ccid, sk);
         if (dp->dccps_options.dccpo_send_ack_vector) {
                 dccp_ackvec_free(dp->dccps_hc_rx_ackvec);
                 dp->dccps_hc_rx_ackvec = NULL;
         }
-        ccid_exit(dp->dccps_hc_rx_ccid, sk);
-        ccid_exit(dp->dccps_hc_tx_ccid, sk);
+        ccid_hc_rx_delete(dp->dccps_hc_rx_ccid, sk);
+        ccid_hc_tx_delete(dp->dccps_hc_tx_ccid, sk);
         dp->dccps_hc_rx_ccid = dp->dccps_hc_tx_ccid = NULL;
 
         /* clean up feature negotiation state */
diff --git a/net/dccp/minisocks.c b/net/dccp/minisocks.c
index 9e1de5919ee5..5324fcacb34d 100644
--- a/net/dccp/minisocks.c
+++ b/net/dccp/minisocks.c
@@ -121,23 +121,21 @@ struct sock *dccp_create_openreq_child(struct sock *sk,
                 if (newdp->dccps_options.dccpo_send_ack_vector) {
                         newdp->dccps_hc_rx_ackvec =
                                                 dccp_ackvec_alloc(GFP_ATOMIC);
-                        /*
-                         * XXX: We're using the same CCIDs set on the parent,
-                         * i.e. sk_clone copied the master sock and left the
-                         * CCID pointers for this child, that is why we do the
-                         * __ccid_get calls.
-                         */
                         if (unlikely(newdp->dccps_hc_rx_ackvec == NULL))
                                 goto out_free;
                 }
 
-                if (unlikely(ccid_hc_rx_init(newdp->dccps_hc_rx_ccid,
-                                             newsk) != 0 ||
-                             ccid_hc_tx_init(newdp->dccps_hc_tx_ccid,
-                                             newsk) != 0)) {
+                newdp->dccps_hc_rx_ccid =
+                            ccid_hc_rx_new(newdp->dccps_options.dccpo_rx_ccid,
+                                           newsk, GFP_ATOMIC);
+                newdp->dccps_hc_tx_ccid =
+                            ccid_hc_tx_new(newdp->dccps_options.dccpo_tx_ccid,
+                                           newsk, GFP_ATOMIC);
+                if (unlikely(newdp->dccps_hc_rx_ccid == NULL ||
+                             newdp->dccps_hc_tx_ccid == NULL)) {
                         dccp_ackvec_free(newdp->dccps_hc_rx_ackvec);
-                        ccid_hc_rx_exit(newdp->dccps_hc_rx_ccid, newsk);
-                        ccid_hc_tx_exit(newdp->dccps_hc_tx_ccid, newsk);
+                        ccid_hc_rx_delete(newdp->dccps_hc_rx_ccid, newsk);
+                        ccid_hc_tx_delete(newdp->dccps_hc_tx_ccid, newsk);
 out_free:
                         /* It is still raw copy of parent, so invalidate
                          * destructor and make plain sk_free() */
@@ -146,9 +144,6 @@ out_free:
                         return NULL;
                 }
 
-                __ccid_get(newdp->dccps_hc_rx_ccid);
-                __ccid_get(newdp->dccps_hc_tx_ccid);
-
                 /*
                  * Step 3: Process LISTEN state
                  *