net/dccp/ccid.c

   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
  19 static struct ccid_operations *ccids[] = {
  20         &ccid2_ops,
  21 #ifdef CONFIG_IP_DCCP_CCID3
  22         &ccid3_ops,
  23 #endif
  24 };
  25
  26 static 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 */
  37 bool 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  * This function allocates memory - caller must see that it is freed after use.
  50  */
  51 int ccid_get_builtin_ccids(u8 **ccid_array, u8 *array_len)
  52 {
  53         *ccid_array = kmalloc(ARRAY_SIZE(ccids), gfp_any());
  54         if (*ccid_array == NULL)
  55                 return -ENOBUFS;
  56
  57         for (*array_len = 0; *array_len < ARRAY_SIZE(ccids); *array_len += 1)
  58                 (*ccid_array)[*array_len] = ccids[*array_len]->ccid_id;
  59         return 0;
  60 }
  61
  62 int ccid_getsockopt_builtin_ccids(struct sock *sk, int len,
  63                                   char __user *optval, int __user *optlen)
  64 {
  65         u8 *ccid_array, array_len;
  66         int err = 0;
  67
  68         if (ccid_get_builtin_ccids(&ccid_array, &array_len))
  69                 return -ENOBUFS;
  70
  71         if (put_user(array_len, optlen))
  72                 err = -EFAULT;
  73         else if (len > 0 && copy_to_user(optval, ccid_array,
  74                                          len > array_len ? array_len : len))
  75                 err = -EFAULT;
  76
  77         kfree(ccid_array);
  78         return err;
  79 }
  80
  81 static struct kmem_cache *ccid_kmem_cache_create(int obj_size, char *slab_name_fmt, const char *fmt,...)
  82 {
  83         struct kmem_cache *slab;
  84         va_list args;
  85
  86         va_start(args, fmt);
  87         vsnprintf(slab_name_fmt, CCID_SLAB_NAME_LENGTH, fmt, args);
  88         va_end(args);
  89
  90         slab = kmem_cache_create(slab_name_fmt, sizeof(struct ccid) + obj_size, 0,
  91                                  SLAB_HWCACHE_ALIGN, NULL);
  92         return slab;
  93 }
  94
  95 static void ccid_kmem_cache_destroy(struct kmem_cache *slab)
  96 {
  97         if (slab != NULL)
  98                 kmem_cache_destroy(slab);
  99 }
 100
 101 static int ccid_activate(struct ccid_operations *ccid_ops)
 102 {
 103         int err = -ENOBUFS;
 104
 105         ccid_ops->ccid_hc_rx_slab =
 106                         ccid_kmem_cache_create(ccid_ops->ccid_hc_rx_obj_size,
 107                                                ccid_ops->ccid_hc_rx_slab_name,
 108                                                "ccid%u_hc_rx_sock",
 109                                                ccid_ops->ccid_id);
 110         if (ccid_ops->ccid_hc_rx_slab == NULL)
 111                 goto out;
 112
 113         ccid_ops->ccid_hc_tx_slab =
 114                         ccid_kmem_cache_create(ccid_ops->ccid_hc_tx_obj_size,
 115                                                ccid_ops->ccid_hc_tx_slab_name,
 116                                                "ccid%u_hc_tx_sock",
 117                                                ccid_ops->ccid_id);
 118         if (ccid_ops->ccid_hc_tx_slab == NULL)
 119                 goto out_free_rx_slab;
 120
 121         pr_info("CCID: Activated CCID %d (%s)\n",
 122                 ccid_ops->ccid_id, ccid_ops->ccid_name);
 123         err = 0;
 124 out:
 125         return err;
 126 out_free_rx_slab:
 127         ccid_kmem_cache_destroy(ccid_ops->ccid_hc_rx_slab);
 128         ccid_ops->ccid_hc_rx_slab = NULL;
 129         goto out;
 130 }
 131
 132 static void ccid_deactivate(struct ccid_operations *ccid_ops)
 133 {
 134         ccid_kmem_cache_destroy(ccid_ops->ccid_hc_tx_slab);
 135         ccid_ops->ccid_hc_tx_slab = NULL;
 136         ccid_kmem_cache_destroy(ccid_ops->ccid_hc_rx_slab);
 137         ccid_ops->ccid_hc_rx_slab = NULL;
 138
 139         pr_info("CCID: Deactivated CCID %d (%s)\n",
 140                 ccid_ops->ccid_id, ccid_ops->ccid_name);
 141 }
 142
 143 struct ccid *ccid_new(const u8 id, struct sock *sk, bool rx)
 144 {
 145         struct ccid_operations *ccid_ops = ccid_by_number(id);
 146         struct ccid *ccid = NULL;
 147
 148         if (ccid_ops == NULL)
 149                 goto out;
 150
 151         ccid = kmem_cache_alloc(rx ? ccid_ops->ccid_hc_rx_slab :
 152                                      ccid_ops->ccid_hc_tx_slab, gfp_any());
 153         if (ccid == NULL)
 154                 goto out;
 155         ccid->ccid_ops = ccid_ops;
 156         if (rx) {
 157                 memset(ccid + 1, 0, ccid_ops->ccid_hc_rx_obj_size);
 158                 if (ccid->ccid_ops->ccid_hc_rx_init != NULL &&
 159                     ccid->ccid_ops->ccid_hc_rx_init(ccid, sk) != 0)
 160                         goto out_free_ccid;
 161         } else {
 162                 memset(ccid + 1, 0, ccid_ops->ccid_hc_tx_obj_size);
 163                 if (ccid->ccid_ops->ccid_hc_tx_init != NULL &&
 164                     ccid->ccid_ops->ccid_hc_tx_init(ccid, sk) != 0)
 165                         goto out_free_ccid;
 166         }
 167 out:
 168         return ccid;
 169 out_free_ccid:
 170         kmem_cache_free(rx ? ccid_ops->ccid_hc_rx_slab :
 171                         ccid_ops->ccid_hc_tx_slab, ccid);
 172         ccid = NULL;
 173         goto out;
 174 }
 175
 176 void ccid_hc_rx_delete(struct ccid *ccid, struct sock *sk)
 177 {
 178         if (ccid != NULL) {
 179                 if (ccid->ccid_ops->ccid_hc_rx_exit != NULL)
 180                         ccid->ccid_ops->ccid_hc_rx_exit(sk);
 181                 kmem_cache_free(ccid->ccid_ops->ccid_hc_rx_slab, ccid);
 182         }
 183 }
 184
 185 void ccid_hc_tx_delete(struct ccid *ccid, struct sock *sk)
 186 {
 187         if (ccid != NULL) {
 188                 if (ccid->ccid_ops->ccid_hc_tx_exit != NULL)
 189                         ccid->ccid_ops->ccid_hc_tx_exit(sk);
 190                 kmem_cache_free(ccid->ccid_ops->ccid_hc_tx_slab, ccid);
 191         }
 192 }
 193
 194 int __init ccid_initialize_builtins(void)
 195 {
 196         int i, err = tfrc_lib_init();
 197
 198         if (err)
 199                 return err;
 200
 201         for (i = 0; i < ARRAY_SIZE(ccids); i++) {
 202                 err = ccid_activate(ccids[i]);
 203                 if (err)
 204                         goto unwind_registrations;
 205         }
 206         return 0;
 207
 208 unwind_registrations:
 209         while(--i >= 0)
 210                 ccid_deactivate(ccids[i]);
 211         tfrc_lib_exit();
 212         return err;
 213 }
 214
 215 void ccid_cleanup_builtins(void)
 216 {
 217         int i;
 218
 219         for (i = 0; i < ARRAY_SIZE(ccids); i++)
 220                 ccid_deactivate(ccids[i]);
 221         tfrc_lib_exit();
 222 }