net/dccp/ccid.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  *  net/dccp/ccid.c
   4  *
   5  *  An implementation of the DCCP protocol
   6  *  Arnaldo Carvalho de Melo <acme@conectiva.com.br>
   7  *
   8  *  CCID infrastructure
   9  */
  10
  11 #include <linux/slab.h>
  12
  13 #include "ccid.h"
  14 #include "ccids/lib/tfrc.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  *
  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         kmem_cache_destroy(slab);
  96 }
  97
  98 static int __init ccid_activate(struct ccid_operations *ccid_ops)
  99 {
 100         int err = -ENOBUFS;
 101
 102         ccid_ops->ccid_hc_rx_slab =
 103                         ccid_kmem_cache_create(ccid_ops->ccid_hc_rx_obj_size,
 104                                                ccid_ops->ccid_hc_rx_slab_name,
 105                                                "ccid%u_hc_rx_sock",
 106                                                ccid_ops->ccid_id);
 107         if (ccid_ops->ccid_hc_rx_slab == NULL)
 108                 goto out;
 109
 110         ccid_ops->ccid_hc_tx_slab =
 111                         ccid_kmem_cache_create(ccid_ops->ccid_hc_tx_obj_size,
 112                                                ccid_ops->ccid_hc_tx_slab_name,
 113                                                "ccid%u_hc_tx_sock",
 114                                                ccid_ops->ccid_id);
 115         if (ccid_ops->ccid_hc_tx_slab == NULL)
 116                 goto out_free_rx_slab;
 117
 118         pr_info("DCCP: Activated CCID %d (%s)\n",
 119                 ccid_ops->ccid_id, ccid_ops->ccid_name);
 120         err = 0;
 121 out:
 122         return err;
 123 out_free_rx_slab:
 124         ccid_kmem_cache_destroy(ccid_ops->ccid_hc_rx_slab);
 125         ccid_ops->ccid_hc_rx_slab = NULL;
 126         goto out;
 127 }
 128
 129 static void ccid_deactivate(struct ccid_operations *ccid_ops)
 130 {
 131         ccid_kmem_cache_destroy(ccid_ops->ccid_hc_tx_slab);
 132         ccid_ops->ccid_hc_tx_slab = NULL;
 133         ccid_kmem_cache_destroy(ccid_ops->ccid_hc_rx_slab);
 134         ccid_ops->ccid_hc_rx_slab = NULL;
 135
 136         pr_info("DCCP: Deactivated CCID %d (%s)\n",
 137                 ccid_ops->ccid_id, ccid_ops->ccid_name);
 138 }
 139
 140 struct ccid *ccid_new(const u8 id, struct sock *sk, bool rx)
 141 {
 142         struct ccid_operations *ccid_ops = ccid_by_number(id);
 143         struct ccid *ccid = NULL;
 144
 145         if (ccid_ops == NULL)
 146                 goto out;
 147
 148         ccid = kmem_cache_alloc(rx ? ccid_ops->ccid_hc_rx_slab :
 149                                      ccid_ops->ccid_hc_tx_slab, gfp_any());
 150         if (ccid == NULL)
 151                 goto out;
 152         ccid->ccid_ops = ccid_ops;
 153         if (rx) {
 154                 memset(ccid + 1, 0, ccid_ops->ccid_hc_rx_obj_size);
 155                 if (ccid->ccid_ops->ccid_hc_rx_init != NULL &&
 156                     ccid->ccid_ops->ccid_hc_rx_init(ccid, sk) != 0)
 157                         goto out_free_ccid;
 158         } else {
 159                 memset(ccid + 1, 0, ccid_ops->ccid_hc_tx_obj_size);
 160                 if (ccid->ccid_ops->ccid_hc_tx_init != NULL &&
 161                     ccid->ccid_ops->ccid_hc_tx_init(ccid, sk) != 0)
 162                         goto out_free_ccid;
 163         }
 164 out:
 165         return ccid;
 166 out_free_ccid:
 167         kmem_cache_free(rx ? ccid_ops->ccid_hc_rx_slab :
 168                         ccid_ops->ccid_hc_tx_slab, ccid);
 169         ccid = NULL;
 170         goto out;
 171 }
 172
 173 void ccid_hc_rx_delete(struct ccid *ccid, struct sock *sk)
 174 {
 175         if (ccid != NULL) {
 176                 if (ccid->ccid_ops->ccid_hc_rx_exit != NULL)
 177                         ccid->ccid_ops->ccid_hc_rx_exit(sk);
 178                 kmem_cache_free(ccid->ccid_ops->ccid_hc_rx_slab, ccid);
 179         }
 180 }
 181
 182 void ccid_hc_tx_delete(struct ccid *ccid, struct sock *sk)
 183 {
 184         if (ccid != NULL) {
 185                 if (ccid->ccid_ops->ccid_hc_tx_exit != NULL)
 186                         ccid->ccid_ops->ccid_hc_tx_exit(sk);
 187                 kmem_cache_free(ccid->ccid_ops->ccid_hc_tx_slab, ccid);
 188         }
 189 }
 190
 191 int __init ccid_initialize_builtins(void)
 192 {
 193         int i, err = tfrc_lib_init();
 194
 195         if (err)
 196                 return err;
 197
 198         for (i = 0; i < ARRAY_SIZE(ccids); i++) {
 199                 err = ccid_activate(ccids[i]);
 200                 if (err)
 201                         goto unwind_registrations;
 202         }
 203         return 0;
 204
 205 unwind_registrations:
 206         while(--i >= 0)
 207                 ccid_deactivate(ccids[i]);
 208         tfrc_lib_exit();
 209         return err;
 210 }
 211
 212 void ccid_cleanup_builtins(void)
 213 {
 214         int i;
 215
 216         for (i = 0; i < ARRAY_SIZE(ccids); i++)
 217                 ccid_deactivate(ccids[i]);
 218         tfrc_lib_exit();
 219 }