linux/net/dccp/ccid.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 *  net/dccp/ccid.c
   4 *
   5 *  An implementation of the DCCP protocol
   6 *  Arnaldo Carvalho de Melo <acme@conectiva.com.br>
   7 *
   8 *  CCID infrastructure
   9 */
  10
  11#include <linux/slab.h>
  12
  13#include "ccid.h"
  14#include "ccids/lib/tfrc.h"
  15
  16static struct ccid_operations *ccids[] = {
  17        &ccid2_ops,
  18#ifdef CONFIG_IP_DCCP_CCID3
  19        &ccid3_ops,
  20#endif
  21};
  22
  23static struct ccid_operations *ccid_by_number(const u8 id)
  24{
  25        int i;
  26
  27        for (i = 0; i < ARRAY_SIZE(ccids); i++)
  28                if (ccids[i]->ccid_id == id)
  29                        return ccids[i];
  30        return NULL;
  31}
  32
  33/* check that up to @array_len members in @ccid_array are supported */
  34bool ccid_support_check(u8 const *ccid_array, u8 array_len)
  35{
  36        while (array_len > 0)
  37                if (ccid_by_number(ccid_array[--array_len]) == NULL)
  38                        return false;
  39        return true;
  40}
  41
  42/**
  43 * ccid_get_builtin_ccids  -  Populate a list of built-in CCIDs
  44 * @ccid_array: pointer to copy into
  45 * @array_len: value to return length into
  46 *
  47 * This function allocates memory - caller must see that it is freed after use.
  48 */
  49int ccid_get_builtin_ccids(u8 **ccid_array, u8 *array_len)
  50{
  51        *ccid_array = kmalloc(ARRAY_SIZE(ccids), gfp_any());
  52        if (*ccid_array == NULL)
  53                return -ENOBUFS;
  54
  55        for (*array_len = 0; *array_len < ARRAY_SIZE(ccids); *array_len += 1)
  56                (*ccid_array)[*array_len] = ccids[*array_len]->ccid_id;
  57        return 0;
  58}
  59
  60int ccid_getsockopt_builtin_ccids(struct sock *sk, int len,
  61                                  char __user *optval, int __user *optlen)
  62{
  63        u8 *ccid_array, array_len;
  64        int err = 0;
  65
  66        if (ccid_get_builtin_ccids(&ccid_array, &array_len))
  67                return -ENOBUFS;
  68
  69        if (put_user(array_len, optlen))
  70                err = -EFAULT;
  71        else if (len > 0 && copy_to_user(optval, ccid_array,
  72                                         len > array_len ? array_len : len))
  73                err = -EFAULT;
  74
  75        kfree(ccid_array);
  76        return err;
  77}
  78
  79static __printf(3, 4) struct kmem_cache *ccid_kmem_cache_create(int obj_size, char *slab_name_fmt, const char *fmt,...)
  80{
  81        struct kmem_cache *slab;
  82        va_list args;
  83
  84        va_start(args, fmt);
  85        vsnprintf(slab_name_fmt, CCID_SLAB_NAME_LENGTH, fmt, args);
  86        va_end(args);
  87
  88        slab = kmem_cache_create(slab_name_fmt, sizeof(struct ccid) + obj_size, 0,
  89                                 SLAB_HWCACHE_ALIGN, NULL);
  90        return slab;
  91}
  92
  93static void ccid_kmem_cache_destroy(struct kmem_cache *slab)
  94{
  95        kmem_cache_destroy(slab);
  96}
  97
  98static int __init ccid_activate(struct ccid_operations *ccid_ops)
  99{
 100        int err = -ENOBUFS;
 101
 102        ccid_ops->ccid_hc_rx_slab =
 103                        ccid_kmem_cache_create(ccid_ops->ccid_hc_rx_obj_size,
 104                                               ccid_ops->ccid_hc_rx_slab_name,
 105                                               "ccid%u_hc_rx_sock",
 106                                               ccid_ops->ccid_id);
 107        if (ccid_ops->ccid_hc_rx_slab == NULL)
 108                goto out;
 109
 110        ccid_ops->ccid_hc_tx_slab =
 111                        ccid_kmem_cache_create(ccid_ops->ccid_hc_tx_obj_size,
 112                                               ccid_ops->ccid_hc_tx_slab_name,
 113                                               "ccid%u_hc_tx_sock",
 114                                               ccid_ops->ccid_id);
 115        if (ccid_ops->ccid_hc_tx_slab == NULL)
 116                goto out_free_rx_slab;
 117
 118        pr_info("DCCP: Activated CCID %d (%s)\n",
 119                ccid_ops->ccid_id, ccid_ops->ccid_name);
 120        err = 0;
 121out:
 122        return err;
 123out_free_rx_slab:
 124        ccid_kmem_cache_destroy(ccid_ops->ccid_hc_rx_slab);
 125        ccid_ops->ccid_hc_rx_slab = NULL;
 126        goto out;
 127}
 128
 129static void ccid_deactivate(struct ccid_operations *ccid_ops)
 130{
 131        ccid_kmem_cache_destroy(ccid_ops->ccid_hc_tx_slab);
 132        ccid_ops->ccid_hc_tx_slab = NULL;
 133        ccid_kmem_cache_destroy(ccid_ops->ccid_hc_rx_slab);
 134        ccid_ops->ccid_hc_rx_slab = NULL;
 135
 136        pr_info("DCCP: Deactivated CCID %d (%s)\n",
 137                ccid_ops->ccid_id, ccid_ops->ccid_name);
 138}
 139
 140struct ccid *ccid_new(const u8 id, struct sock *sk, bool rx)
 141{
 142        struct ccid_operations *ccid_ops = ccid_by_number(id);
 143        struct ccid *ccid = NULL;
 144
 145        if (ccid_ops == NULL)
 146                goto out;
 147
 148        ccid = kmem_cache_alloc(rx ? ccid_ops->ccid_hc_rx_slab :
 149                                     ccid_ops->ccid_hc_tx_slab, gfp_any());
 150        if (ccid == NULL)
 151                goto out;
 152        ccid->ccid_ops = ccid_ops;
 153        if (rx) {
 154                memset(ccid + 1, 0, ccid_ops->ccid_hc_rx_obj_size);
 155                if (ccid->ccid_ops->ccid_hc_rx_init != NULL &&
 156                    ccid->ccid_ops->ccid_hc_rx_init(ccid, sk) != 0)
 157                        goto out_free_ccid;
 158        } else {
 159                memset(ccid + 1, 0, ccid_ops->ccid_hc_tx_obj_size);
 160                if (ccid->ccid_ops->ccid_hc_tx_init != NULL &&
 161                    ccid->ccid_ops->ccid_hc_tx_init(ccid, sk) != 0)
 162                        goto out_free_ccid;
 163        }
 164out:
 165        return ccid;
 166out_free_ccid:
 167        kmem_cache_free(rx ? ccid_ops->ccid_hc_rx_slab :
 168                        ccid_ops->ccid_hc_tx_slab, ccid);
 169        ccid = NULL;
 170        goto out;
 171}
 172
 173void ccid_hc_rx_delete(struct ccid *ccid, struct sock *sk)
 174{
 175        if (ccid != NULL) {
 176                if (ccid->ccid_ops->ccid_hc_rx_exit != NULL)
 177                        ccid->ccid_ops->ccid_hc_rx_exit(sk);
 178                kmem_cache_free(ccid->ccid_ops->ccid_hc_rx_slab, ccid);
 179        }
 180}
 181
 182void ccid_hc_tx_delete(struct ccid *ccid, struct sock *sk)
 183{
 184        if (ccid != NULL) {
 185                if (ccid->ccid_ops->ccid_hc_tx_exit != NULL)
 186                        ccid->ccid_ops->ccid_hc_tx_exit(sk);
 187                kmem_cache_free(ccid->ccid_ops->ccid_hc_tx_slab, ccid);
 188        }
 189}
 190
 191int __init ccid_initialize_builtins(void)
 192{
 193        int i, err = tfrc_lib_init();
 194
 195        if (err)
 196                return err;
 197
 198        for (i = 0; i < ARRAY_SIZE(ccids); i++) {
 199                err = ccid_activate(ccids[i]);
 200                if (err)
 201                        goto unwind_registrations;
 202        }
 203        return 0;
 204
 205unwind_registrations:
 206        while(--i >= 0)
 207                ccid_deactivate(ccids[i]);
 208        tfrc_lib_exit();
 209        return err;
 210}
 211
 212void ccid_cleanup_builtins(void)
 213{
 214        int i;
 215
 216        for (i = 0; i < ARRAY_SIZE(ccids); i++)
 217                ccid_deactivate(ccids[i]);
 218        tfrc_lib_exit();
 219}
 220