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
  16 static struct ccid_operations *ccids[] = {
  17         &ccid2_ops,
  18 #ifdef CONFIG_IP_DCCP_CCID3
  19         &ccid3_ops,
  20 #endif
  21 };
  22
  23 static 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 */
  34 bool 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  * This function allocates memory - caller must see that it is freed after use.
  47  */
  48 int ccid_get_builtin_ccids(u8 **ccid_array, u8 *array_len)
  49 {
  50         *ccid_array = kmalloc(ARRAY_SIZE(ccids), gfp_any());
  51         if (*ccid_array == NULL)
  52                 return -ENOBUFS;
  53
  54         for (*array_len = 0; *array_len < ARRAY_SIZE(ccids); *array_len += 1)
  55                 (*ccid_array)[*array_len] = ccids[*array_len]->ccid_id;
  56         return 0;
  57 }
  58
  59 int ccid_getsockopt_builtin_ccids(struct sock *sk, int len,
  60                                   char __user *optval, int __user *optlen)
  61 {
  62         u8 *ccid_array, array_len;
  63         int err = 0;
  64
  65         if (len < ARRAY_SIZE(ccids))
  66                 return -EINVAL;
  67
  68         if (ccid_get_builtin_ccids(&ccid_array, &array_len))
  69                 return -ENOBUFS;
  70
  71         if (put_user(array_len, optlen) ||
  72             copy_to_user(optval, ccid_array, array_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, const char *fmt,...)
  80 {
  81         struct kmem_cache *slab;
  82         char slab_name_fmt[32], *slab_name;
  83         va_list args;
  84
  85         va_start(args, fmt);
  86         vsnprintf(slab_name_fmt, sizeof(slab_name_fmt), fmt, args);
  87         va_end(args);
  88
  89         slab_name = kstrdup(slab_name_fmt, GFP_KERNEL);
  90         if (slab_name == NULL)
  91                 return NULL;
  92         slab = kmem_cache_create(slab_name, sizeof(struct ccid) + obj_size, 0,
  93                                  SLAB_HWCACHE_ALIGN, NULL);
  94         if (slab == NULL)
  95                 kfree(slab_name);
  96         return slab;
  97 }
  98
  99 static void ccid_kmem_cache_destroy(struct kmem_cache *slab)
 100 {
 101         if (slab != NULL) {
 102                 const char *name = kmem_cache_name(slab);
 103
 104                 kmem_cache_destroy(slab);
 105                 kfree(name);
 106         }
 107 }
 108
 109 static int ccid_activate(struct ccid_operations *ccid_ops)
 110 {
 111         int err = -ENOBUFS;
 112
 113         ccid_ops->ccid_hc_rx_slab =
 114                         ccid_kmem_cache_create(ccid_ops->ccid_hc_rx_obj_size,
 115                                                "ccid%u_hc_rx_sock",
 116                                                ccid_ops->ccid_id);
 117         if (ccid_ops->ccid_hc_rx_slab == NULL)
 118                 goto out;
 119
 120         ccid_ops->ccid_hc_tx_slab =
 121                         ccid_kmem_cache_create(ccid_ops->ccid_hc_tx_obj_size,
 122                                                "ccid%u_hc_tx_sock",
 123                                                ccid_ops->ccid_id);
 124         if (ccid_ops->ccid_hc_tx_slab == NULL)
 125                 goto out_free_rx_slab;
 126
 127         pr_info("CCID: Activated CCID %d (%s)\n",
 128                 ccid_ops->ccid_id, ccid_ops->ccid_name);
 129         err = 0;
 130 out:
 131         return err;
 132 out_free_rx_slab:
 133         ccid_kmem_cache_destroy(ccid_ops->ccid_hc_rx_slab);
 134         ccid_ops->ccid_hc_rx_slab = NULL;
 135         goto out;
 136 }
 137
 138 static void ccid_deactivate(struct ccid_operations *ccid_ops)
 139 {
 140         ccid_kmem_cache_destroy(ccid_ops->ccid_hc_tx_slab);
 141         ccid_ops->ccid_hc_tx_slab = NULL;
 142         ccid_kmem_cache_destroy(ccid_ops->ccid_hc_rx_slab);
 143         ccid_ops->ccid_hc_rx_slab = NULL;
 144
 145         pr_info("CCID: Deactivated CCID %d (%s)\n",
 146                 ccid_ops->ccid_id, ccid_ops->ccid_name);
 147 }
 148
 149 struct ccid *ccid_new(const u8 id, struct sock *sk, bool rx)
 150 {
 151         struct ccid_operations *ccid_ops = ccid_by_number(id);
 152         struct ccid *ccid = NULL;
 153
 154         if (ccid_ops == NULL)
 155                 goto out;
 156
 157         ccid = kmem_cache_alloc(rx ? ccid_ops->ccid_hc_rx_slab :
 158                                      ccid_ops->ccid_hc_tx_slab, gfp_any());
 159         if (ccid == NULL)
 160                 goto out;
 161         ccid->ccid_ops = ccid_ops;
 162         if (rx) {
 163                 memset(ccid + 1, 0, ccid_ops->ccid_hc_rx_obj_size);
 164                 if (ccid->ccid_ops->ccid_hc_rx_init != NULL &&
 165                     ccid->ccid_ops->ccid_hc_rx_init(ccid, sk) != 0)
 166                         goto out_free_ccid;
 167         } else {
 168                 memset(ccid + 1, 0, ccid_ops->ccid_hc_tx_obj_size);
 169                 if (ccid->ccid_ops->ccid_hc_tx_init != NULL &&
 170                     ccid->ccid_ops->ccid_hc_tx_init(ccid, sk) != 0)
 171                         goto out_free_ccid;
 172         }
 173 out:
 174         return ccid;
 175 out_free_ccid:
 176         kmem_cache_free(rx ? ccid_ops->ccid_hc_rx_slab :
 177                         ccid_ops->ccid_hc_tx_slab, ccid);
 178         ccid = NULL;
 179         goto out;
 180 }
 181
 182 void ccid_hc_rx_delete(struct ccid *ccid, struct sock *sk)
 183 {
 184         if (ccid != NULL) {
 185                 if (ccid->ccid_ops->ccid_hc_rx_exit != NULL)
 186                         ccid->ccid_ops->ccid_hc_rx_exit(sk);
 187                 kmem_cache_free(ccid->ccid_ops->ccid_hc_rx_slab, ccid);
 188         }
 189 }
 190
 191 void ccid_hc_tx_delete(struct ccid *ccid, struct sock *sk)
 192 {
 193         if (ccid != NULL) {
 194                 if (ccid->ccid_ops->ccid_hc_tx_exit != NULL)
 195                         ccid->ccid_ops->ccid_hc_tx_exit(sk);
 196                 kmem_cache_free(ccid->ccid_ops->ccid_hc_tx_slab, ccid);
 197         }
 198 }
 199
 200 int __init ccid_initialize_builtins(void)
 201 {
 202         int i, err;
 203
 204         for (i = 0; i < ARRAY_SIZE(ccids); i++) {
 205                 err = ccid_activate(ccids[i]);
 206                 if (err)
 207                         goto unwind_registrations;
 208         }
 209         return 0;
 210
 211 unwind_registrations:
 212         while(--i >= 0)
 213                 ccid_deactivate(ccids[i]);
 214         return err;
 215 }
 216
 217 void ccid_cleanup_builtins(void)
 218 {
 219         int i;
 220
 221         for (i = 0; i < ARRAY_SIZE(ccids); i++)
 222                 ccid_deactivate(ccids[i]);
 223 }