forked from luck/tmp_suning_uos_patched
09856c1089
This adds auto-loading of CCIDs (when module loading is enabled) for the purpose of feature negotiation. The problem with loading the CCIDs at the end of feature negotiation is that this would happen in software interrupt context. Besides, if the host advertises CCIDs during negotiation, it should have them ready to use, in case an agreeing peer wants to use it for the connection. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Signed-off-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
311 lines
7.4 KiB
C
311 lines
7.4 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 u8 builtin_ccids[] = {
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DCCPC_CCID2, /* CCID2 is supported by default */
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#if defined(CONFIG_IP_DCCP_CCID3) || defined(CONFIG_IP_DCCP_CCID3_MODULE)
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DCCPC_CCID3,
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#endif
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};
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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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smp_mb__after_atomic_inc();
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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 struct kmem_cache *ccid_kmem_cache_create(int obj_size, const char *fmt,...)
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{
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struct kmem_cache *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);
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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(struct kmem_cache *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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/* check that up to @array_len members in @ccid_array are supported */
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bool ccid_support_check(u8 const *ccid_array, u8 array_len)
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{
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u8 i, j, found;
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for (i = 0, found = 0; i < array_len; i++, found = 0) {
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for (j = 0; !found && j < ARRAY_SIZE(builtin_ccids); j++)
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found = (ccid_array[i] == builtin_ccids[j]);
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if (!found)
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return false;
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}
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return true;
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}
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/**
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* ccid_get_builtin_ccids - Provide copy of `builtin' CCID array
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* @ccid_array: pointer to copy into
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* @array_len: value to return length into
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* This function allocates memory - caller must see that it is freed after use.
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*/
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int ccid_get_builtin_ccids(u8 **ccid_array, u8 *array_len)
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{
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*ccid_array = kmemdup(builtin_ccids, sizeof(builtin_ccids), gfp_any());
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if (*ccid_array == NULL)
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return -ENOBUFS;
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*array_len = ARRAY_SIZE(builtin_ccids);
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return 0;
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}
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int ccid_getsockopt_builtin_ccids(struct sock *sk, int len,
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char __user *optval, int __user *optlen)
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{
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if (len < sizeof(builtin_ccids))
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return -EINVAL;
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if (put_user(sizeof(builtin_ccids), optlen) ||
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copy_to_user(optval, builtin_ccids, sizeof(builtin_ccids)))
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return -EFAULT;
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return 0;
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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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"ccid%u_hc_rx_sock",
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ccid_ops->ccid_id);
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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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"ccid%u_hc_tx_sock",
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ccid_ops->ccid_id);
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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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/**
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* ccid_request_module - Pre-load CCID module for later use
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* This should be called only from process context (e.g. during connection
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* setup) and is necessary for later calls to ccid_new (typically in software
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* interrupt), so that it has the modules available when they are needed.
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*/
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static int ccid_request_module(u8 id)
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{
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if (!in_atomic()) {
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ccids_read_lock();
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if (ccids[id] == NULL) {
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ccids_read_unlock();
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return request_module("net-dccp-ccid-%d", id);
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}
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ccids_read_unlock();
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}
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return 0;
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}
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int ccid_request_modules(u8 const *ccid_array, u8 array_len)
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{
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#ifdef CONFIG_KMOD
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while (array_len--)
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if (ccid_request_module(ccid_array[array_len]))
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return -1;
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#endif
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return 0;
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}
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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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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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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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