linux/net/dccp/ccid.c
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   1/*
   2 *  net/dccp/ccid.c
   3 *
   4 *  An implementation of the DCCP protocol
   5 *  Arnaldo Carvalho de Melo <acme@conectiva.com.br>
   6 *
   7 *  CCID infrastructure
   8 *
   9 *      This program is free software; you can redistribute it and/or modify it
  10 *      under the terms of the GNU General Public License version 2 as
  11 *      published by the Free Software Foundation.
  12 */
  13
  14#include <linux/slab.h>
  15
  16#include "ccid.h"
  17#include "ccids/lib/tfrc.h"
  18
  19static struct ccid_operations *ccids[] = {
  20        &ccid2_ops,
  21#ifdef CONFIG_IP_DCCP_CCID3
  22        &ccid3_ops,
  23#endif
  24};
  25
  26static struct ccid_operations *ccid_by_number(const u8 id)
  27{
  28        int i;
  29
  30        for (i = 0; i < ARRAY_SIZE(ccids); i++)
  31                if (ccids[i]->ccid_id == id)
  32                        return ccids[i];
  33        return NULL;
  34}
  35
  36/* check that up to @array_len members in @ccid_array are supported */
  37bool ccid_support_check(u8 const *ccid_array, u8 array_len)
  38{
  39        while (array_len > 0)
  40                if (ccid_by_number(ccid_array[--array_len]) == NULL)
  41                        return false;
  42        return true;
  43}
  44
  45/**
  46 * ccid_get_builtin_ccids  -  Populate a list of built-in CCIDs
  47 * @ccid_array: pointer to copy into
  48 * @array_len: value to return length into
  49 *
  50 * This function allocates memory - caller must see that it is freed after use.
  51 */
  52int ccid_get_builtin_ccids(u8 **ccid_array, u8 *array_len)
  53{
  54        *ccid_array = kmalloc(ARRAY_SIZE(ccids), gfp_any());
  55        if (*ccid_array == NULL)
  56                return -ENOBUFS;
  57
  58        for (*array_len = 0; *array_len < ARRAY_SIZE(ccids); *array_len += 1)
  59                (*ccid_array)[*array_len] = ccids[*array_len]->ccid_id;
  60        return 0;
  61}
  62
  63int ccid_getsockopt_builtin_ccids(struct sock *sk, int len,
  64                                  char __user *optval, int __user *optlen)
  65{
  66        u8 *ccid_array, array_len;
  67        int err = 0;
  68
  69        if (ccid_get_builtin_ccids(&ccid_array, &array_len))
  70                return -ENOBUFS;
  71
  72        if (put_user(array_len, optlen))
  73                err = -EFAULT;
  74        else if (len > 0 && copy_to_user(optval, ccid_array,
  75                                         len > array_len ? array_len : len))
  76                err = -EFAULT;
  77
  78        kfree(ccid_array);
  79        return err;
  80}
  81
  82static struct kmem_cache *ccid_kmem_cache_create(int obj_size, char *slab_name_fmt, const char *fmt,...)
  83{
  84        struct kmem_cache *slab;
  85        va_list args;
  86
  87        va_start(args, fmt);
  88        vsnprintf(slab_name_fmt, CCID_SLAB_NAME_LENGTH, fmt, args);
  89        va_end(args);
  90
  91        slab = kmem_cache_create(slab_name_fmt, sizeof(struct ccid) + obj_size, 0,
  92                                 SLAB_HWCACHE_ALIGN, NULL);
  93        return slab;
  94}
  95
  96static void ccid_kmem_cache_destroy(struct kmem_cache *slab)
  97{
  98        if (slab != NULL)
  99                kmem_cache_destroy(slab);
 100}
 101
 102static int ccid_activate(struct ccid_operations *ccid_ops)
 103{
 104        int err = -ENOBUFS;
 105
 106        ccid_ops->ccid_hc_rx_slab =
 107                        ccid_kmem_cache_create(ccid_ops->ccid_hc_rx_obj_size,
 108                                               ccid_ops->ccid_hc_rx_slab_name,
 109                                               "ccid%u_hc_rx_sock",
 110                                               ccid_ops->ccid_id);
 111        if (ccid_ops->ccid_hc_rx_slab == NULL)
 112                goto out;
 113
 114        ccid_ops->ccid_hc_tx_slab =
 115                        ccid_kmem_cache_create(ccid_ops->ccid_hc_tx_obj_size,
 116                                               ccid_ops->ccid_hc_tx_slab_name,
 117                                               "ccid%u_hc_tx_sock",
 118                                               ccid_ops->ccid_id);
 119        if (ccid_ops->ccid_hc_tx_slab == NULL)
 120                goto out_free_rx_slab;
 121
 122        pr_info("DCCP: Activated CCID %d (%s)\n",
 123                ccid_ops->ccid_id, ccid_ops->ccid_name);
 124        err = 0;
 125out:
 126        return err;
 127out_free_rx_slab:
 128        ccid_kmem_cache_destroy(ccid_ops->ccid_hc_rx_slab);
 129        ccid_ops->ccid_hc_rx_slab = NULL;
 130        goto out;
 131}
 132
 133static void ccid_deactivate(struct ccid_operations *ccid_ops)
 134{
 135        ccid_kmem_cache_destroy(ccid_ops->ccid_hc_tx_slab);
 136        ccid_ops->ccid_hc_tx_slab = NULL;
 137        ccid_kmem_cache_destroy(ccid_ops->ccid_hc_rx_slab);
 138        ccid_ops->ccid_hc_rx_slab = NULL;
 139
 140        pr_info("DCCP: Deactivated CCID %d (%s)\n",
 141                ccid_ops->ccid_id, ccid_ops->ccid_name);
 142}
 143
 144struct ccid *ccid_new(const u8 id, struct sock *sk, bool rx)
 145{
 146        struct ccid_operations *ccid_ops = ccid_by_number(id);
 147        struct ccid *ccid = NULL;
 148
 149        if (ccid_ops == NULL)
 150                goto out;
 151
 152        ccid = kmem_cache_alloc(rx ? ccid_ops->ccid_hc_rx_slab :
 153                                     ccid_ops->ccid_hc_tx_slab, gfp_any());
 154        if (ccid == NULL)
 155                goto out;
 156        ccid->ccid_ops = ccid_ops;
 157        if (rx) {
 158                memset(ccid + 1, 0, ccid_ops->ccid_hc_rx_obj_size);
 159                if (ccid->ccid_ops->ccid_hc_rx_init != NULL &&
 160                    ccid->ccid_ops->ccid_hc_rx_init(ccid, sk) != 0)
 161                        goto out_free_ccid;
 162        } else {
 163                memset(ccid + 1, 0, ccid_ops->ccid_hc_tx_obj_size);
 164                if (ccid->ccid_ops->ccid_hc_tx_init != NULL &&
 165                    ccid->ccid_ops->ccid_hc_tx_init(ccid, sk) != 0)
 166                        goto out_free_ccid;
 167        }
 168out:
 169        return ccid;
 170out_free_ccid:
 171        kmem_cache_free(rx ? ccid_ops->ccid_hc_rx_slab :
 172                        ccid_ops->ccid_hc_tx_slab, ccid);
 173        ccid = NULL;
 174        goto out;
 175}
 176
 177void ccid_hc_rx_delete(struct ccid *ccid, struct sock *sk)
 178{
 179        if (ccid != NULL) {
 180                if (ccid->ccid_ops->ccid_hc_rx_exit != NULL)
 181                        ccid->ccid_ops->ccid_hc_rx_exit(sk);
 182                kmem_cache_free(ccid->ccid_ops->ccid_hc_rx_slab, ccid);
 183        }
 184}
 185
 186void ccid_hc_tx_delete(struct ccid *ccid, struct sock *sk)
 187{
 188        if (ccid != NULL) {
 189                if (ccid->ccid_ops->ccid_hc_tx_exit != NULL)
 190                        ccid->ccid_ops->ccid_hc_tx_exit(sk);
 191                kmem_cache_free(ccid->ccid_ops->ccid_hc_tx_slab, ccid);
 192        }
 193}
 194
 195int __init ccid_initialize_builtins(void)
 196{
 197        int i, err = tfrc_lib_init();
 198
 199        if (err)
 200                return err;
 201
 202        for (i = 0; i < ARRAY_SIZE(ccids); i++) {
 203                err = ccid_activate(ccids[i]);
 204                if (err)
 205                        goto unwind_registrations;
 206        }
 207        return 0;
 208
 209unwind_registrations:
 210        while(--i >= 0)
 211                ccid_deactivate(ccids[i]);
 212        tfrc_lib_exit();
 213        return err;
 214}
 215
 216void ccid_cleanup_builtins(void)
 217{
 218        int i;
 219
 220        for (i = 0; i < ARRAY_SIZE(ccids); i++)
 221                ccid_deactivate(ccids[i]);
 222        tfrc_lib_exit();
 223}
 224
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