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, char *slab_name_fmt, const char *fmt,...)
  81 {
  82         struct kmem_cache *slab;
  83         va_list args;
  84
  85         va_start(args, fmt);
  86         vsnprintf(slab_name_fmt, CCID_SLAB_NAME_LENGTH, fmt, args);
  87         va_end(args);
  88
  89         slab = kmem_cache_create(slab_name_fmt, sizeof(struct ccid) + obj_size, 0,
  90                                  SLAB_HWCACHE_ALIGN, NULL);
  91         return slab;
  92 }
  93
  94 static void ccid_kmem_cache_destroy(struct kmem_cache *slab)
  95 {
  96         if (slab != NULL)
  97                 kmem_cache_destroy(slab);
  98 }
  99
 100 static int ccid_activate(struct ccid_operations *ccid_ops)
 101 {
 102         int err = -ENOBUFS;
 103
 104         ccid_ops->ccid_hc_rx_slab =
 105                         ccid_kmem_cache_create(ccid_ops->ccid_hc_rx_obj_size,
 106                                                ccid_ops->ccid_hc_rx_slab_name,
 107                                                "ccid%u_hc_rx_sock",
 108                                                ccid_ops->ccid_id);
 109         if (ccid_ops->ccid_hc_rx_slab == NULL)
 110                 goto out;
 111
 112         ccid_ops->ccid_hc_tx_slab =
 113                         ccid_kmem_cache_create(ccid_ops->ccid_hc_tx_obj_size,
 114                                                ccid_ops->ccid_hc_tx_slab_name,
 115                                                "ccid%u_hc_tx_sock",
 116                                                ccid_ops->ccid_id);
 117         if (ccid_ops->ccid_hc_tx_slab == NULL)
 118                 goto out_free_rx_slab;
 119
 120         pr_info("CCID: Activated CCID %d (%s)\n",
 121                 ccid_ops->ccid_id, ccid_ops->ccid_name);
 122         err = 0;
 123 out:
 124         return err;
 125 out_free_rx_slab:
 126         ccid_kmem_cache_destroy(ccid_ops->ccid_hc_rx_slab);
 127         ccid_ops->ccid_hc_rx_slab = NULL;
 128         goto out;
 129 }
 130
 131 static void ccid_deactivate(struct ccid_operations *ccid_ops)
 132 {
 133         ccid_kmem_cache_destroy(ccid_ops->ccid_hc_tx_slab);
 134         ccid_ops->ccid_hc_tx_slab = NULL;
 135         ccid_kmem_cache_destroy(ccid_ops->ccid_hc_rx_slab);
 136         ccid_ops->ccid_hc_rx_slab = NULL;
 137
 138         pr_info("CCID: Deactivated CCID %d (%s)\n",
 139                 ccid_ops->ccid_id, ccid_ops->ccid_name);
 140 }
 141
 142 struct ccid *ccid_new(const u8 id, struct sock *sk, bool rx)
 143 {
 144         struct ccid_operations *ccid_ops = ccid_by_number(id);
 145         struct ccid *ccid = NULL;
 146
 147         if (ccid_ops == NULL)
 148                 goto out;
 149
 150         ccid = kmem_cache_alloc(rx ? ccid_ops->ccid_hc_rx_slab :
 151                                      ccid_ops->ccid_hc_tx_slab, gfp_any());
 152         if (ccid == NULL)
 153                 goto out;
 154         ccid->ccid_ops = ccid_ops;
 155         if (rx) {
 156                 memset(ccid + 1, 0, ccid_ops->ccid_hc_rx_obj_size);
 157                 if (ccid->ccid_ops->ccid_hc_rx_init != NULL &&
 158                     ccid->ccid_ops->ccid_hc_rx_init(ccid, sk) != 0)
 159                         goto out_free_ccid;
 160         } else {
 161                 memset(ccid + 1, 0, ccid_ops->ccid_hc_tx_obj_size);
 162                 if (ccid->ccid_ops->ccid_hc_tx_init != NULL &&
 163                     ccid->ccid_ops->ccid_hc_tx_init(ccid, sk) != 0)
 164                         goto out_free_ccid;
 165         }
 166 out:
 167         return ccid;
 168 out_free_ccid:
 169         kmem_cache_free(rx ? ccid_ops->ccid_hc_rx_slab :
 170                         ccid_ops->ccid_hc_tx_slab, ccid);
 171         ccid = NULL;
 172         goto out;
 173 }
 174
 175 void ccid_hc_rx_delete(struct ccid *ccid, struct sock *sk)
 176 {
 177         if (ccid != NULL) {
 178                 if (ccid->ccid_ops->ccid_hc_rx_exit != NULL)
 179                         ccid->ccid_ops->ccid_hc_rx_exit(sk);
 180                 kmem_cache_free(ccid->ccid_ops->ccid_hc_rx_slab, ccid);
 181         }
 182 }
 183
 184 void ccid_hc_tx_delete(struct ccid *ccid, struct sock *sk)
 185 {
 186         if (ccid != NULL) {
 187                 if (ccid->ccid_ops->ccid_hc_tx_exit != NULL)
 188                         ccid->ccid_ops->ccid_hc_tx_exit(sk);
 189                 kmem_cache_free(ccid->ccid_ops->ccid_hc_tx_slab, ccid);
 190         }
 191 }
 192
 193 int __init ccid_initialize_builtins(void)
 194 {
 195         int i, err = tfrc_lib_init();
 196
 197         if (err)
 198                 return err;
 199
 200         for (i = 0; i < ARRAY_SIZE(ccids); i++) {
 201                 err = ccid_activate(ccids[i]);
 202                 if (err)
 203                         goto unwind_registrations;
 204         }
 205         return 0;
 206
 207 unwind_registrations:
 208         while(--i >= 0)
 209                 ccid_deactivate(ccids[i]);
 210         tfrc_lib_exit();
 211         return err;
 212 }
 213
 214 void ccid_cleanup_builtins(void)
 215 {
 216         int i;
 217
 218         for (i = 0; i < ARRAY_SIZE(ccids); i++)
 219                 ccid_deactivate(ccids[i]);
 220         tfrc_lib_exit();
 221 }