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![Arnaldo Carvalho de Melo](/assets/img/avatar_default.png)
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>
256 lines
5.9 KiB
C
256 lines
5.9 KiB
C
/*
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* net/dccp/ccid.c
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*
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* An implementation of the DCCP protocol
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* Arnaldo Carvalho de Melo <acme@conectiva.com.br>
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*
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* CCID infrastructure
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include "ccid.h"
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static struct ccid_operations *ccids[CCID_MAX];
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#if defined(CONFIG_SMP) || defined(CONFIG_PREEMPT)
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static atomic_t ccids_lockct = ATOMIC_INIT(0);
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static DEFINE_SPINLOCK(ccids_lock);
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/*
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* The strategy is: modifications ccids vector are short, do not sleep and
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* veeery rare, but read access should be free of any exclusive locks.
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*/
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static void ccids_write_lock(void)
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{
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spin_lock(&ccids_lock);
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while (atomic_read(&ccids_lockct) != 0) {
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spin_unlock(&ccids_lock);
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yield();
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spin_lock(&ccids_lock);
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}
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}
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static inline void ccids_write_unlock(void)
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{
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spin_unlock(&ccids_lock);
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}
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static inline void ccids_read_lock(void)
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{
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atomic_inc(&ccids_lockct);
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spin_unlock_wait(&ccids_lock);
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}
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static inline void ccids_read_unlock(void)
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{
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atomic_dec(&ccids_lockct);
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}
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#else
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#define ccids_write_lock() do { } while(0)
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#define ccids_write_unlock() do { } while(0)
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#define ccids_read_lock() do { } while(0)
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#define ccids_read_unlock() do { } while(0)
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#endif
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static kmem_cache_t *ccid_kmem_cache_create(int obj_size, const char *fmt,...)
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{
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kmem_cache_t *slab;
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char slab_name_fmt[32], *slab_name;
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va_list args;
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va_start(args, fmt);
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vsnprintf(slab_name_fmt, sizeof(slab_name_fmt), fmt, args);
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va_end(args);
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slab_name = kstrdup(slab_name_fmt, GFP_KERNEL);
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if (slab_name == NULL)
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return NULL;
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slab = kmem_cache_create(slab_name, sizeof(struct ccid) + obj_size, 0,
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SLAB_HWCACHE_ALIGN, NULL, NULL);
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if (slab == NULL)
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kfree(slab_name);
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return slab;
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}
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static void ccid_kmem_cache_destroy(kmem_cache_t *slab)
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{
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if (slab != NULL) {
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const char *name = kmem_cache_name(slab);
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kmem_cache_destroy(slab);
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kfree(name);
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}
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}
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int ccid_register(struct ccid_operations *ccid_ops)
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{
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int err = -ENOBUFS;
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ccid_ops->ccid_hc_rx_slab =
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ccid_kmem_cache_create(ccid_ops->ccid_hc_rx_obj_size,
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"%s_hc_rx_sock",
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ccid_ops->ccid_name);
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if (ccid_ops->ccid_hc_rx_slab == NULL)
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goto out;
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ccid_ops->ccid_hc_tx_slab =
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ccid_kmem_cache_create(ccid_ops->ccid_hc_tx_obj_size,
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"%s_hc_tx_sock",
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ccid_ops->ccid_name);
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if (ccid_ops->ccid_hc_tx_slab == NULL)
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goto out_free_rx_slab;
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ccids_write_lock();
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err = -EEXIST;
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if (ccids[ccid_ops->ccid_id] == NULL) {
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ccids[ccid_ops->ccid_id] = ccid_ops;
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err = 0;
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}
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ccids_write_unlock();
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if (err != 0)
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goto out_free_tx_slab;
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pr_info("CCID: Registered CCID %d (%s)\n",
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ccid_ops->ccid_id, ccid_ops->ccid_name);
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out:
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return err;
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out_free_tx_slab:
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ccid_kmem_cache_destroy(ccid_ops->ccid_hc_tx_slab);
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ccid_ops->ccid_hc_tx_slab = NULL;
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goto out;
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out_free_rx_slab:
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ccid_kmem_cache_destroy(ccid_ops->ccid_hc_rx_slab);
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ccid_ops->ccid_hc_rx_slab = NULL;
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goto out;
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}
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EXPORT_SYMBOL_GPL(ccid_register);
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int ccid_unregister(struct ccid_operations *ccid_ops)
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{
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ccids_write_lock();
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ccids[ccid_ops->ccid_id] = NULL;
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ccids_write_unlock();
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ccid_kmem_cache_destroy(ccid_ops->ccid_hc_tx_slab);
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ccid_ops->ccid_hc_tx_slab = NULL;
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ccid_kmem_cache_destroy(ccid_ops->ccid_hc_rx_slab);
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ccid_ops->ccid_hc_rx_slab = NULL;
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pr_info("CCID: Unregistered CCID %d (%s)\n",
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ccid_ops->ccid_id, ccid_ops->ccid_name);
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return 0;
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}
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EXPORT_SYMBOL_GPL(ccid_unregister);
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struct ccid *ccid_new(unsigned char id, struct sock *sk, int rx, gfp_t gfp)
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{
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struct ccid_operations *ccid_ops;
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struct ccid *ccid = NULL;
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ccids_read_lock();
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#ifdef CONFIG_KMOD
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if (ccids[id] == NULL) {
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/* We only try to load if in process context */
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ccids_read_unlock();
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if (gfp & GFP_ATOMIC)
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goto out;
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request_module("net-dccp-ccid-%d", id);
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ccids_read_lock();
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}
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#endif
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ccid_ops = ccids[id];
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if (ccid_ops == NULL)
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goto out_unlock;
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if (!try_module_get(ccid_ops->ccid_owner))
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goto out_unlock;
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ccids_read_unlock();
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ccid = kmem_cache_alloc(rx ? ccid_ops->ccid_hc_rx_slab :
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ccid_ops->ccid_hc_tx_slab, gfp);
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if (ccid == NULL)
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goto out_module_put;
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ccid->ccid_ops = ccid_ops;
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if (rx) {
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memset(ccid + 1, 0, ccid_ops->ccid_hc_rx_obj_size);
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if (ccid->ccid_ops->ccid_hc_rx_init != NULL &&
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ccid->ccid_ops->ccid_hc_rx_init(ccid, sk) != 0)
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goto out_free_ccid;
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} else {
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memset(ccid + 1, 0, ccid_ops->ccid_hc_tx_obj_size);
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if (ccid->ccid_ops->ccid_hc_tx_init != NULL &&
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ccid->ccid_ops->ccid_hc_tx_init(ccid, sk) != 0)
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goto out_free_ccid;
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}
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out:
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return ccid;
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out_unlock:
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ccids_read_unlock();
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goto out;
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out_free_ccid:
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kmem_cache_free(rx ? ccid_ops->ccid_hc_rx_slab :
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ccid_ops->ccid_hc_tx_slab, ccid);
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ccid = NULL;
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out_module_put:
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module_put(ccid_ops->ccid_owner);
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goto out;
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}
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EXPORT_SYMBOL_GPL(ccid_new);
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struct ccid *ccid_hc_rx_new(unsigned char id, struct sock *sk, gfp_t gfp)
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{
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return ccid_new(id, sk, 1, gfp);
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}
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EXPORT_SYMBOL_GPL(ccid_hc_rx_new);
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struct ccid *ccid_hc_tx_new(unsigned char id,struct sock *sk, gfp_t gfp)
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{
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return ccid_new(id, sk, 0, gfp);
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}
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EXPORT_SYMBOL_GPL(ccid_hc_tx_new);
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static void ccid_delete(struct ccid *ccid, struct sock *sk, int rx)
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{
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struct ccid_operations *ccid_ops;
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if (ccid == NULL)
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return;
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ccid_ops = ccid->ccid_ops;
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if (rx) {
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if (ccid_ops->ccid_hc_rx_exit != NULL)
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ccid_ops->ccid_hc_rx_exit(sk);
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kmem_cache_free(ccid_ops->ccid_hc_rx_slab, ccid);
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} else {
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if (ccid_ops->ccid_hc_tx_exit != NULL)
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ccid_ops->ccid_hc_tx_exit(sk);
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kmem_cache_free(ccid_ops->ccid_hc_tx_slab, ccid);
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}
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ccids_read_lock();
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if (ccids[ccid_ops->ccid_id] != NULL)
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module_put(ccid_ops->ccid_owner);
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ccids_read_unlock();
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}
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void ccid_hc_rx_delete(struct ccid *ccid, struct sock *sk)
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{
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ccid_delete(ccid, sk, 1);
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}
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EXPORT_SYMBOL_GPL(ccid_hc_rx_delete);
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void ccid_hc_tx_delete(struct ccid *ccid, struct sock *sk)
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{
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ccid_delete(ccid, sk, 0);
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}
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EXPORT_SYMBOL_GPL(ccid_hc_tx_delete);
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