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 (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
  79 static 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
  93 static void ccid_kmem_cache_destroy(struct kmem_cache *slab)
  94 {
  95         if (slab != NULL)
  96                 kmem_cache_destroy(slab);
  97 }
  98
  99 static int ccid_activate(struct ccid_operations *ccid_ops)
 100 {
 101         int err = -ENOBUFS;
 102
 103         ccid_ops->ccid_hc_rx_slab =
 104                         ccid_kmem_cache_create(ccid_ops->ccid_hc_rx_obj_size,
 105                                                ccid_ops->ccid_hc_rx_slab_name,
 106                                                "ccid%u_hc_rx_sock",
 107                                                ccid_ops->ccid_id);
 108         if (ccid_ops->ccid_hc_rx_slab == NULL)
 109                 goto out;
 110
 111         ccid_ops->ccid_hc_tx_slab =
 112                         ccid_kmem_cache_create(ccid_ops->ccid_hc_tx_obj_size,
 113                                                ccid_ops->ccid_hc_tx_slab_name,
 114                                                "ccid%u_hc_tx_sock",
 115                                                ccid_ops->ccid_id);
 116         if (ccid_ops->ccid_hc_tx_slab == NULL)
 117                 goto out_free_rx_slab;
 118
 119         pr_info("CCID: Activated CCID %d (%s)\n",
 120                 ccid_ops->ccid_id, ccid_ops->ccid_name);
 121         err = 0;
 122 out:
 123         return err;
 124 out_free_rx_slab:
 125         ccid_kmem_cache_destroy(ccid_ops->ccid_hc_rx_slab);
 126         ccid_ops->ccid_hc_rx_slab = NULL;
 127         goto out;
 128 }
 129
 130 static void ccid_deactivate(struct ccid_operations *ccid_ops)
 131 {
 132         ccid_kmem_cache_destroy(ccid_ops->ccid_hc_tx_slab);
 133         ccid_ops->ccid_hc_tx_slab = NULL;
 134         ccid_kmem_cache_destroy(ccid_ops->ccid_hc_rx_slab);
 135         ccid_ops->ccid_hc_rx_slab = NULL;
 136
 137         pr_info("CCID: Deactivated CCID %d (%s)\n",
 138                 ccid_ops->ccid_id, ccid_ops->ccid_name);
 139 }
 140
 141 struct ccid *ccid_new(const u8 id, struct sock *sk, bool rx)
 142 {
 143         struct ccid_operations *ccid_ops = ccid_by_number(id);
 144         struct ccid *ccid = NULL;
 145
 146         if (ccid_ops == NULL)
 147                 goto out;
 148
 149         ccid = kmem_cache_alloc(rx ? ccid_ops->ccid_hc_rx_slab :
 150                                      ccid_ops->ccid_hc_tx_slab, gfp_any());
 151         if (ccid == NULL)
 152                 goto out;
 153         ccid->ccid_ops = ccid_ops;
 154         if (rx) {
 155                 memset(ccid + 1, 0, ccid_ops->ccid_hc_rx_obj_size);
 156                 if (ccid->ccid_ops->ccid_hc_rx_init != NULL &&
 157                     ccid->ccid_ops->ccid_hc_rx_init(ccid, sk) != 0)
 158                         goto out_free_ccid;
 159         } else {
 160                 memset(ccid + 1, 0, ccid_ops->ccid_hc_tx_obj_size);
 161                 if (ccid->ccid_ops->ccid_hc_tx_init != NULL &&
 162                     ccid->ccid_ops->ccid_hc_tx_init(ccid, sk) != 0)
 163                         goto out_free_ccid;
 164         }
 165 out:
 166         return ccid;
 167 out_free_ccid:
 168         kmem_cache_free(rx ? ccid_ops->ccid_hc_rx_slab :
 169                         ccid_ops->ccid_hc_tx_slab, ccid);
 170         ccid = NULL;
 171         goto out;
 172 }
 173
 174 void ccid_hc_rx_delete(struct ccid *ccid, struct sock *sk)
 175 {
 176         if (ccid != NULL) {
 177                 if (ccid->ccid_ops->ccid_hc_rx_exit != NULL)
 178                         ccid->ccid_ops->ccid_hc_rx_exit(sk);
 179                 kmem_cache_free(ccid->ccid_ops->ccid_hc_rx_slab, ccid);
 180         }
 181 }
 182
 183 void ccid_hc_tx_delete(struct ccid *ccid, struct sock *sk)
 184 {
 185         if (ccid != NULL) {
 186                 if (ccid->ccid_ops->ccid_hc_tx_exit != NULL)
 187                         ccid->ccid_ops->ccid_hc_tx_exit(sk);
 188                 kmem_cache_free(ccid->ccid_ops->ccid_hc_tx_slab, ccid);
 189         }
 190 }
 191
 192 int __init ccid_initialize_builtins(void)
 193 {
 194         int i, err = tfrc_lib_init();
 195
 196         if (err)
 197                 return err;
 198
 199         for (i = 0; i < ARRAY_SIZE(ccids); i++) {
 200                 err = ccid_activate(ccids[i]);
 201                 if (err)
 202                         goto unwind_registrations;
 203         }
 204         return 0;
 205
 206 unwind_registrations:
 207         while(--i >= 0)
 208                 ccid_deactivate(ccids[i]);
 209         tfrc_lib_exit();
 210         return err;
 211 }
 212
 213 void ccid_cleanup_builtins(void)
 214 {
 215         int i;
 216
 217         for (i = 0; i < ARRAY_SIZE(ccids); i++)
 218                 ccid_deactivate(ccids[i]);
 219         tfrc_lib_exit();
 220 }