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 "ccid.h"
  15 #include "ccids/lib/tfrc.h"
  16
  17 static struct ccid_operations *ccids[] = {
  18         &ccid2_ops,
  19 #ifdef CONFIG_IP_DCCP_CCID3
  20         &ccid3_ops,
  21 #endif
  22 };
  23
  24 static struct ccid_operations *ccid_by_number(const u8 id)
  25 {
  26         int i;
  27
  28         for (i = 0; i < ARRAY_SIZE(ccids); i++)
  29                 if (ccids[i]->ccid_id == id)
  30                         return ccids[i];
  31         return NULL;
  32 }
  33
  34 /* check that up to @array_len members in @ccid_array are supported */
  35 bool ccid_support_check(u8 const *ccid_array, u8 array_len)
  36 {
  37         while (array_len > 0)
  38                 if (ccid_by_number(ccid_array[--array_len]) == NULL)
  39                         return false;
  40         return true;
  41 }
  42
  43 /**
  44  * ccid_get_builtin_ccids  -  Populate a list of built-in CCIDs
  45  * @ccid_array: pointer to copy into
  46  * @array_len: value to return length into
  47  * This function allocates memory - caller must see that it is freed after use.
  48  */
  49 int 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
  60 int 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 (len < ARRAY_SIZE(ccids))
  67                 return -EINVAL;
  68
  69         if (ccid_get_builtin_ccids(&ccid_array, &array_len))
  70                 return -ENOBUFS;
  71
  72         if (put_user(array_len, optlen) ||
  73             copy_to_user(optval, ccid_array, array_len))
  74                 err = -EFAULT;
  75
  76         kfree(ccid_array);
  77         return err;
  78 }
  79
  80 static struct kmem_cache *ccid_kmem_cache_create(int obj_size, const char *fmt,...)
  81 {
  82         struct kmem_cache *slab;
  83         char slab_name_fmt[32], *slab_name;
  84         va_list args;
  85
  86         va_start(args, fmt);
  87         vsnprintf(slab_name_fmt, sizeof(slab_name_fmt), fmt, args);
  88         va_end(args);
  89
  90         slab_name = kstrdup(slab_name_fmt, GFP_KERNEL);
  91         if (slab_name == NULL)
  92                 return NULL;
  93         slab = kmem_cache_create(slab_name, sizeof(struct ccid) + obj_size, 0,
  94                                  SLAB_HWCACHE_ALIGN, NULL);
  95         if (slab == NULL)
  96                 kfree(slab_name);
  97         return slab;
  98 }
  99
 100 static void ccid_kmem_cache_destroy(struct kmem_cache *slab)
 101 {
 102         if (slab != NULL) {
 103                 const char *name = kmem_cache_name(slab);
 104
 105                 kmem_cache_destroy(slab);
 106                 kfree(name);
 107         }
 108 }
 109
 110 static int ccid_activate(struct ccid_operations *ccid_ops)
 111 {
 112         int err = -ENOBUFS;
 113
 114         ccid_ops->ccid_hc_rx_slab =
 115                         ccid_kmem_cache_create(ccid_ops->ccid_hc_rx_obj_size,
 116                                                "ccid%u_hc_rx_sock",
 117                                                ccid_ops->ccid_id);
 118         if (ccid_ops->ccid_hc_rx_slab == NULL)
 119                 goto out;
 120
 121         ccid_ops->ccid_hc_tx_slab =
 122                         ccid_kmem_cache_create(ccid_ops->ccid_hc_tx_obj_size,
 123                                                "ccid%u_hc_tx_sock",
 124                                                ccid_ops->ccid_id);
 125         if (ccid_ops->ccid_hc_tx_slab == NULL)
 126                 goto out_free_rx_slab;
 127
 128         pr_info("CCID: Activated CCID %d (%s)\n",
 129                 ccid_ops->ccid_id, ccid_ops->ccid_name);
 130         err = 0;
 131 out:
 132         return err;
 133 out_free_rx_slab:
 134         ccid_kmem_cache_destroy(ccid_ops->ccid_hc_rx_slab);
 135         ccid_ops->ccid_hc_rx_slab = NULL;
 136         goto out;
 137 }
 138
 139 static void ccid_deactivate(struct ccid_operations *ccid_ops)
 140 {
 141         ccid_kmem_cache_destroy(ccid_ops->ccid_hc_tx_slab);
 142         ccid_ops->ccid_hc_tx_slab = NULL;
 143         ccid_kmem_cache_destroy(ccid_ops->ccid_hc_rx_slab);
 144         ccid_ops->ccid_hc_rx_slab = NULL;
 145
 146         pr_info("CCID: Deactivated CCID %d (%s)\n",
 147                 ccid_ops->ccid_id, ccid_ops->ccid_name);
 148 }
 149
 150 struct ccid *ccid_new(const u8 id, struct sock *sk, bool rx)
 151 {
 152         struct ccid_operations *ccid_ops = ccid_by_number(id);
 153         struct ccid *ccid = NULL;
 154
 155         if (ccid_ops == NULL)
 156                 goto out;
 157
 158         ccid = kmem_cache_alloc(rx ? ccid_ops->ccid_hc_rx_slab :
 159                                      ccid_ops->ccid_hc_tx_slab, gfp_any());
 160         if (ccid == NULL)
 161                 goto out;
 162         ccid->ccid_ops = ccid_ops;
 163         if (rx) {
 164                 memset(ccid + 1, 0, ccid_ops->ccid_hc_rx_obj_size);
 165                 if (ccid->ccid_ops->ccid_hc_rx_init != NULL &&
 166                     ccid->ccid_ops->ccid_hc_rx_init(ccid, sk) != 0)
 167                         goto out_free_ccid;
 168         } else {
 169                 memset(ccid + 1, 0, ccid_ops->ccid_hc_tx_obj_size);
 170                 if (ccid->ccid_ops->ccid_hc_tx_init != NULL &&
 171                     ccid->ccid_ops->ccid_hc_tx_init(ccid, sk) != 0)
 172                         goto out_free_ccid;
 173         }
 174 out:
 175         return ccid;
 176 out_free_ccid:
 177         kmem_cache_free(rx ? ccid_ops->ccid_hc_rx_slab :
 178                         ccid_ops->ccid_hc_tx_slab, ccid);
 179         ccid = NULL;
 180         goto out;
 181 }
 182
 183 void ccid_hc_rx_delete(struct ccid *ccid, struct sock *sk)
 184 {
 185         if (ccid != NULL) {
 186                 if (ccid->ccid_ops->ccid_hc_rx_exit != NULL)
 187                         ccid->ccid_ops->ccid_hc_rx_exit(sk);
 188                 kmem_cache_free(ccid->ccid_ops->ccid_hc_rx_slab, ccid);
 189         }
 190 }
 191
 192 void ccid_hc_tx_delete(struct ccid *ccid, struct sock *sk)
 193 {
 194         if (ccid != NULL) {
 195                 if (ccid->ccid_ops->ccid_hc_tx_exit != NULL)
 196                         ccid->ccid_ops->ccid_hc_tx_exit(sk);
 197                 kmem_cache_free(ccid->ccid_ops->ccid_hc_tx_slab, ccid);
 198         }
 199 }
 200
 201 int __init ccid_initialize_builtins(void)
 202 {
 203         int i, err = tfrc_lib_init();
 204
 205         if (err)
 206                 return err;
 207
 208         for (i = 0; i < ARRAY_SIZE(ccids); i++) {
 209                 err = ccid_activate(ccids[i]);
 210                 if (err)
 211                         goto unwind_registrations;
 212         }
 213         return 0;
 214
 215 unwind_registrations:
 216         while(--i >= 0)
 217                 ccid_deactivate(ccids[i]);
 218         tfrc_lib_exit();
 219         return err;
 220 }
 221
 222 void ccid_cleanup_builtins(void)
 223 {
 224         int i;
 225
 226         for (i = 0; i < ARRAY_SIZE(ccids); i++)
 227                 ccid_deactivate(ccids[i]);
 228         tfrc_lib_exit();
 229 }