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 <linux/slab.h>
  15
  16 #include "ccid.h"
  17 #include "ccids/lib/tfrc.h"
  18
  19 static struct ccid_operations *ccids[] = {
  20         &ccid2_ops,
  21 #ifdef CONFIG_IP_DCCP_CCID3
  22         &ccid3_ops,
  23 #endif
  24 };
  25
  26 static struct ccid_operations *ccid_by_number(const u8 id)
  27 {
  28         int i;
  29
  30         for (i = 0; i < ARRAY_SIZE(ccids); i++)
  31                 if (ccids[i]->ccid_id == id)
  32                         return ccids[i];
  33         return NULL;
  34 }
  35
  36 /* check that up to @array_len members in @ccid_array are supported */
  37 bool ccid_support_check(u8 const *ccid_array, u8 array_len)
  38 {
  39         while (array_len > 0)
  40                 if (ccid_by_number(ccid_array[--array_len]) == NULL)
  41                         return false;
  42         return true;
  43 }
  44
  45 /**
  46  * ccid_get_builtin_ccids  -  Populate a list of built-in CCIDs
  47  * @ccid_array: pointer to copy into
  48  * @array_len: value to return length into
  49  *
  50  * This function allocates memory - caller must see that it is freed after use.
  51  */
  52 int ccid_get_builtin_ccids(u8 **ccid_array, u8 *array_len)
  53 {
  54         *ccid_array = kmalloc(ARRAY_SIZE(ccids), gfp_any());
  55         if (*ccid_array == NULL)
  56                 return -ENOBUFS;
  57
  58         for (*array_len = 0; *array_len < ARRAY_SIZE(ccids); *array_len += 1)
  59                 (*ccid_array)[*array_len] = ccids[*array_len]->ccid_id;
  60         return 0;
  61 }
  62
  63 int ccid_getsockopt_builtin_ccids(struct sock *sk, int len,
  64                                   char __user *optval, int __user *optlen)
  65 {
  66         u8 *ccid_array, array_len;
  67         int err = 0;
  68
  69         if (ccid_get_builtin_ccids(&ccid_array, &array_len))
  70                 return -ENOBUFS;
  71
  72         if (put_user(array_len, optlen))
  73                 err = -EFAULT;
  74         else if (len > 0 && copy_to_user(optval, ccid_array,
  75                                          len > array_len ? array_len : len))
  76                 err = -EFAULT;
  77
  78         kfree(ccid_array);
  79         return err;
  80 }
  81
  82 static struct kmem_cache *ccid_kmem_cache_create(int obj_size, char *slab_name_fmt, const char *fmt,...)
  83 {
  84         struct kmem_cache *slab;
  85         va_list args;
  86
  87         va_start(args, fmt);
  88         vsnprintf(slab_name_fmt, CCID_SLAB_NAME_LENGTH, fmt, args);
  89         va_end(args);
  90
  91         slab = kmem_cache_create(slab_name_fmt, sizeof(struct ccid) + obj_size, 0,
  92                                  SLAB_HWCACHE_ALIGN, NULL);
  93         return slab;
  94 }
  95
  96 static void ccid_kmem_cache_destroy(struct kmem_cache *slab)
  97 {
  98         if (slab != NULL)
  99                 kmem_cache_destroy(slab);
 100 }
 101
 102 static int __init ccid_activate(struct ccid_operations *ccid_ops)
 103 {
 104         int err = -ENOBUFS;
 105
 106         ccid_ops->ccid_hc_rx_slab =
 107                         ccid_kmem_cache_create(ccid_ops->ccid_hc_rx_obj_size,
 108                                                ccid_ops->ccid_hc_rx_slab_name,
 109                                                "ccid%u_hc_rx_sock",
 110                                                ccid_ops->ccid_id);
 111         if (ccid_ops->ccid_hc_rx_slab == NULL)
 112                 goto out;
 113
 114         ccid_ops->ccid_hc_tx_slab =
 115                         ccid_kmem_cache_create(ccid_ops->ccid_hc_tx_obj_size,
 116                                                ccid_ops->ccid_hc_tx_slab_name,
 117                                                "ccid%u_hc_tx_sock",
 118                                                ccid_ops->ccid_id);
 119         if (ccid_ops->ccid_hc_tx_slab == NULL)
 120                 goto out_free_rx_slab;
 121
 122         pr_info("DCCP: Activated CCID %d (%s)\n",
 123                 ccid_ops->ccid_id, ccid_ops->ccid_name);
 124         err = 0;
 125 out:
 126         return err;
 127 out_free_rx_slab:
 128         ccid_kmem_cache_destroy(ccid_ops->ccid_hc_rx_slab);
 129         ccid_ops->ccid_hc_rx_slab = NULL;
 130         goto out;
 131 }
 132
 133 static void ccid_deactivate(struct ccid_operations *ccid_ops)
 134 {
 135         ccid_kmem_cache_destroy(ccid_ops->ccid_hc_tx_slab);
 136         ccid_ops->ccid_hc_tx_slab = NULL;
 137         ccid_kmem_cache_destroy(ccid_ops->ccid_hc_rx_slab);
 138         ccid_ops->ccid_hc_rx_slab = NULL;
 139
 140         pr_info("DCCP: Deactivated CCID %d (%s)\n",
 141                 ccid_ops->ccid_id, ccid_ops->ccid_name);
 142 }
 143
 144 struct ccid *ccid_new(const u8 id, struct sock *sk, bool rx)
 145 {
 146         struct ccid_operations *ccid_ops = ccid_by_number(id);
 147         struct ccid *ccid = NULL;
 148
 149         if (ccid_ops == NULL)
 150                 goto out;
 151
 152         ccid = kmem_cache_alloc(rx ? ccid_ops->ccid_hc_rx_slab :
 153                                      ccid_ops->ccid_hc_tx_slab, gfp_any());
 154         if (ccid == NULL)
 155                 goto out;
 156         ccid->ccid_ops = ccid_ops;
 157         if (rx) {
 158                 memset(ccid + 1, 0, ccid_ops->ccid_hc_rx_obj_size);
 159                 if (ccid->ccid_ops->ccid_hc_rx_init != NULL &&
 160                     ccid->ccid_ops->ccid_hc_rx_init(ccid, sk) != 0)
 161                         goto out_free_ccid;
 162         } else {
 163                 memset(ccid + 1, 0, ccid_ops->ccid_hc_tx_obj_size);
 164                 if (ccid->ccid_ops->ccid_hc_tx_init != NULL &&
 165                     ccid->ccid_ops->ccid_hc_tx_init(ccid, sk) != 0)
 166                         goto out_free_ccid;
 167         }
 168 out:
 169         return ccid;
 170 out_free_ccid:
 171         kmem_cache_free(rx ? ccid_ops->ccid_hc_rx_slab :
 172                         ccid_ops->ccid_hc_tx_slab, ccid);
 173         ccid = NULL;
 174         goto out;
 175 }
 176
 177 void ccid_hc_rx_delete(struct ccid *ccid, struct sock *sk)
 178 {
 179         if (ccid != NULL) {
 180                 if (ccid->ccid_ops->ccid_hc_rx_exit != NULL)
 181                         ccid->ccid_ops->ccid_hc_rx_exit(sk);
 182                 kmem_cache_free(ccid->ccid_ops->ccid_hc_rx_slab, ccid);
 183         }
 184 }
 185
 186 void ccid_hc_tx_delete(struct ccid *ccid, struct sock *sk)
 187 {
 188         if (ccid != NULL) {
 189                 if (ccid->ccid_ops->ccid_hc_tx_exit != NULL)
 190                         ccid->ccid_ops->ccid_hc_tx_exit(sk);
 191                 kmem_cache_free(ccid->ccid_ops->ccid_hc_tx_slab, ccid);
 192         }
 193 }
 194
 195 int __init ccid_initialize_builtins(void)
 196 {
 197         int i, err = tfrc_lib_init();
 198
 199         if (err)
 200                 return err;
 201
 202         for (i = 0; i < ARRAY_SIZE(ccids); i++) {
 203                 err = ccid_activate(ccids[i]);
 204                 if (err)
 205                         goto unwind_registrations;
 206         }
 207         return 0;
 208
 209 unwind_registrations:
 210         while(--i >= 0)
 211                 ccid_deactivate(ccids[i]);
 212         tfrc_lib_exit();
 213         return err;
 214 }
 215
 216 void ccid_cleanup_builtins(void)
 217 {
 218         int i;
 219
 220         for (i = 0; i < ARRAY_SIZE(ccids); i++)
 221                 ccid_deactivate(ccids[i]);
 222         tfrc_lib_exit();
 223 }