Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 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 | |
Gerrit Renker | d90ebcb | 2008-11-12 00:47:26 -0800 | [diff] [blame] | 16 | static u8 builtin_ccids[] = { |
| 17 | DCCPC_CCID2, /* CCID2 is supported by default */ |
| 18 | #if defined(CONFIG_IP_DCCP_CCID3) || defined(CONFIG_IP_DCCP_CCID3_MODULE) |
| 19 | DCCPC_CCID3, |
| 20 | #endif |
| 21 | }; |
| 22 | |
Arnaldo Carvalho de Melo | 91f0ebf | 2006-03-20 19:21:44 -0800 | [diff] [blame] | 23 | static struct ccid_operations *ccids[CCID_MAX]; |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 24 | #if defined(CONFIG_SMP) || defined(CONFIG_PREEMPT) |
| 25 | static atomic_t ccids_lockct = ATOMIC_INIT(0); |
| 26 | static DEFINE_SPINLOCK(ccids_lock); |
| 27 | |
| 28 | /* |
| 29 | * The strategy is: modifications ccids vector are short, do not sleep and |
| 30 | * veeery rare, but read access should be free of any exclusive locks. |
| 31 | */ |
| 32 | static void ccids_write_lock(void) |
| 33 | { |
| 34 | spin_lock(&ccids_lock); |
| 35 | while (atomic_read(&ccids_lockct) != 0) { |
| 36 | spin_unlock(&ccids_lock); |
| 37 | yield(); |
| 38 | spin_lock(&ccids_lock); |
| 39 | } |
| 40 | } |
| 41 | |
| 42 | static inline void ccids_write_unlock(void) |
| 43 | { |
| 44 | spin_unlock(&ccids_lock); |
| 45 | } |
| 46 | |
| 47 | static inline void ccids_read_lock(void) |
| 48 | { |
| 49 | atomic_inc(&ccids_lockct); |
Oleg Nesterov | d725fdc | 2007-08-10 15:21:17 -0700 | [diff] [blame] | 50 | smp_mb__after_atomic_inc(); |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 51 | spin_unlock_wait(&ccids_lock); |
| 52 | } |
| 53 | |
| 54 | static inline void ccids_read_unlock(void) |
| 55 | { |
| 56 | atomic_dec(&ccids_lockct); |
| 57 | } |
| 58 | |
| 59 | #else |
| 60 | #define ccids_write_lock() do { } while(0) |
| 61 | #define ccids_write_unlock() do { } while(0) |
| 62 | #define ccids_read_lock() do { } while(0) |
| 63 | #define ccids_read_unlock() do { } while(0) |
| 64 | #endif |
| 65 | |
Christoph Lameter | e18b890 | 2006-12-06 20:33:20 -0800 | [diff] [blame] | 66 | static struct kmem_cache *ccid_kmem_cache_create(int obj_size, const char *fmt,...) |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 67 | { |
Christoph Lameter | e18b890 | 2006-12-06 20:33:20 -0800 | [diff] [blame] | 68 | struct kmem_cache *slab; |
Arnaldo Carvalho de Melo | 91f0ebf | 2006-03-20 19:21:44 -0800 | [diff] [blame] | 69 | char slab_name_fmt[32], *slab_name; |
| 70 | va_list args; |
| 71 | |
| 72 | va_start(args, fmt); |
| 73 | vsnprintf(slab_name_fmt, sizeof(slab_name_fmt), fmt, args); |
| 74 | va_end(args); |
| 75 | |
| 76 | slab_name = kstrdup(slab_name_fmt, GFP_KERNEL); |
| 77 | if (slab_name == NULL) |
| 78 | return NULL; |
| 79 | slab = kmem_cache_create(slab_name, sizeof(struct ccid) + obj_size, 0, |
Paul Mundt | 20c2df8 | 2007-07-20 10:11:58 +0900 | [diff] [blame] | 80 | SLAB_HWCACHE_ALIGN, NULL); |
Arnaldo Carvalho de Melo | 91f0ebf | 2006-03-20 19:21:44 -0800 | [diff] [blame] | 81 | if (slab == NULL) |
| 82 | kfree(slab_name); |
| 83 | return slab; |
| 84 | } |
| 85 | |
Christoph Lameter | e18b890 | 2006-12-06 20:33:20 -0800 | [diff] [blame] | 86 | static void ccid_kmem_cache_destroy(struct kmem_cache *slab) |
Arnaldo Carvalho de Melo | 91f0ebf | 2006-03-20 19:21:44 -0800 | [diff] [blame] | 87 | { |
| 88 | if (slab != NULL) { |
| 89 | const char *name = kmem_cache_name(slab); |
| 90 | |
| 91 | kmem_cache_destroy(slab); |
| 92 | kfree(name); |
| 93 | } |
| 94 | } |
| 95 | |
Gerrit Renker | d90ebcb | 2008-11-12 00:47:26 -0800 | [diff] [blame] | 96 | /* check that up to @array_len members in @ccid_array are supported */ |
| 97 | bool ccid_support_check(u8 const *ccid_array, u8 array_len) |
| 98 | { |
| 99 | u8 i, j, found; |
| 100 | |
| 101 | for (i = 0, found = 0; i < array_len; i++, found = 0) { |
| 102 | for (j = 0; !found && j < ARRAY_SIZE(builtin_ccids); j++) |
| 103 | found = (ccid_array[i] == builtin_ccids[j]); |
| 104 | if (!found) |
| 105 | return false; |
| 106 | } |
| 107 | return true; |
| 108 | } |
| 109 | |
| 110 | /** |
| 111 | * ccid_get_builtin_ccids - Provide copy of `builtin' CCID array |
| 112 | * @ccid_array: pointer to copy into |
| 113 | * @array_len: value to return length into |
| 114 | * This function allocates memory - caller must see that it is freed after use. |
| 115 | */ |
| 116 | int ccid_get_builtin_ccids(u8 **ccid_array, u8 *array_len) |
| 117 | { |
| 118 | *ccid_array = kmemdup(builtin_ccids, sizeof(builtin_ccids), gfp_any()); |
| 119 | if (*ccid_array == NULL) |
| 120 | return -ENOBUFS; |
| 121 | *array_len = ARRAY_SIZE(builtin_ccids); |
| 122 | return 0; |
| 123 | } |
| 124 | |
| 125 | int ccid_getsockopt_builtin_ccids(struct sock *sk, int len, |
| 126 | char __user *optval, int __user *optlen) |
| 127 | { |
| 128 | if (len < sizeof(builtin_ccids)) |
| 129 | return -EINVAL; |
| 130 | |
| 131 | if (put_user(sizeof(builtin_ccids), optlen) || |
| 132 | copy_to_user(optval, builtin_ccids, sizeof(builtin_ccids))) |
| 133 | return -EFAULT; |
| 134 | return 0; |
| 135 | } |
| 136 | |
Arnaldo Carvalho de Melo | 91f0ebf | 2006-03-20 19:21:44 -0800 | [diff] [blame] | 137 | int ccid_register(struct ccid_operations *ccid_ops) |
| 138 | { |
| 139 | int err = -ENOBUFS; |
| 140 | |
| 141 | ccid_ops->ccid_hc_rx_slab = |
| 142 | ccid_kmem_cache_create(ccid_ops->ccid_hc_rx_obj_size, |
Gerrit Renker | 84a97b0 | 2007-12-13 23:33:25 -0200 | [diff] [blame] | 143 | "ccid%u_hc_rx_sock", |
| 144 | ccid_ops->ccid_id); |
Arnaldo Carvalho de Melo | 91f0ebf | 2006-03-20 19:21:44 -0800 | [diff] [blame] | 145 | if (ccid_ops->ccid_hc_rx_slab == NULL) |
| 146 | goto out; |
| 147 | |
| 148 | ccid_ops->ccid_hc_tx_slab = |
| 149 | ccid_kmem_cache_create(ccid_ops->ccid_hc_tx_obj_size, |
Gerrit Renker | 84a97b0 | 2007-12-13 23:33:25 -0200 | [diff] [blame] | 150 | "ccid%u_hc_tx_sock", |
| 151 | ccid_ops->ccid_id); |
Arnaldo Carvalho de Melo | 91f0ebf | 2006-03-20 19:21:44 -0800 | [diff] [blame] | 152 | if (ccid_ops->ccid_hc_tx_slab == NULL) |
| 153 | goto out_free_rx_slab; |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 154 | |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 155 | ccids_write_lock(); |
| 156 | err = -EEXIST; |
Arnaldo Carvalho de Melo | 91f0ebf | 2006-03-20 19:21:44 -0800 | [diff] [blame] | 157 | if (ccids[ccid_ops->ccid_id] == NULL) { |
| 158 | ccids[ccid_ops->ccid_id] = ccid_ops; |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 159 | err = 0; |
| 160 | } |
| 161 | ccids_write_unlock(); |
Arnaldo Carvalho de Melo | 91f0ebf | 2006-03-20 19:21:44 -0800 | [diff] [blame] | 162 | if (err != 0) |
| 163 | goto out_free_tx_slab; |
| 164 | |
| 165 | pr_info("CCID: Registered CCID %d (%s)\n", |
| 166 | ccid_ops->ccid_id, ccid_ops->ccid_name); |
| 167 | out: |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 168 | return err; |
Arnaldo Carvalho de Melo | 91f0ebf | 2006-03-20 19:21:44 -0800 | [diff] [blame] | 169 | out_free_tx_slab: |
| 170 | ccid_kmem_cache_destroy(ccid_ops->ccid_hc_tx_slab); |
| 171 | ccid_ops->ccid_hc_tx_slab = NULL; |
| 172 | goto out; |
| 173 | out_free_rx_slab: |
| 174 | ccid_kmem_cache_destroy(ccid_ops->ccid_hc_rx_slab); |
| 175 | ccid_ops->ccid_hc_rx_slab = NULL; |
| 176 | goto out; |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 177 | } |
| 178 | |
| 179 | EXPORT_SYMBOL_GPL(ccid_register); |
| 180 | |
Arnaldo Carvalho de Melo | 91f0ebf | 2006-03-20 19:21:44 -0800 | [diff] [blame] | 181 | int ccid_unregister(struct ccid_operations *ccid_ops) |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 182 | { |
| 183 | ccids_write_lock(); |
Arnaldo Carvalho de Melo | 91f0ebf | 2006-03-20 19:21:44 -0800 | [diff] [blame] | 184 | ccids[ccid_ops->ccid_id] = NULL; |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 185 | ccids_write_unlock(); |
Arnaldo Carvalho de Melo | 91f0ebf | 2006-03-20 19:21:44 -0800 | [diff] [blame] | 186 | |
| 187 | ccid_kmem_cache_destroy(ccid_ops->ccid_hc_tx_slab); |
| 188 | ccid_ops->ccid_hc_tx_slab = NULL; |
| 189 | ccid_kmem_cache_destroy(ccid_ops->ccid_hc_rx_slab); |
| 190 | ccid_ops->ccid_hc_rx_slab = NULL; |
| 191 | |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 192 | pr_info("CCID: Unregistered CCID %d (%s)\n", |
Arnaldo Carvalho de Melo | 91f0ebf | 2006-03-20 19:21:44 -0800 | [diff] [blame] | 193 | ccid_ops->ccid_id, ccid_ops->ccid_name); |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 194 | return 0; |
| 195 | } |
| 196 | |
| 197 | EXPORT_SYMBOL_GPL(ccid_unregister); |
| 198 | |
Arnaldo Carvalho de Melo | 91f0ebf | 2006-03-20 19:21:44 -0800 | [diff] [blame] | 199 | struct ccid *ccid_new(unsigned char id, struct sock *sk, int rx, gfp_t gfp) |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 200 | { |
Arnaldo Carvalho de Melo | 91f0ebf | 2006-03-20 19:21:44 -0800 | [diff] [blame] | 201 | struct ccid_operations *ccid_ops; |
| 202 | struct ccid *ccid = NULL; |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 203 | |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 204 | ccids_read_lock(); |
Johannes Berg | 95a5afc | 2008-10-16 15:24:51 -0700 | [diff] [blame] | 205 | #ifdef CONFIG_MODULES |
Arnaldo Carvalho de Melo | 91f0ebf | 2006-03-20 19:21:44 -0800 | [diff] [blame] | 206 | if (ccids[id] == NULL) { |
| 207 | /* We only try to load if in process context */ |
| 208 | ccids_read_unlock(); |
| 209 | if (gfp & GFP_ATOMIC) |
| 210 | goto out; |
| 211 | request_module("net-dccp-ccid-%d", id); |
| 212 | ccids_read_lock(); |
| 213 | } |
| 214 | #endif |
| 215 | ccid_ops = ccids[id]; |
| 216 | if (ccid_ops == NULL) |
| 217 | goto out_unlock; |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 218 | |
Arnaldo Carvalho de Melo | 91f0ebf | 2006-03-20 19:21:44 -0800 | [diff] [blame] | 219 | if (!try_module_get(ccid_ops->ccid_owner)) |
| 220 | goto out_unlock; |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 221 | |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 222 | ccids_read_unlock(); |
Arnaldo Carvalho de Melo | 91f0ebf | 2006-03-20 19:21:44 -0800 | [diff] [blame] | 223 | |
| 224 | ccid = kmem_cache_alloc(rx ? ccid_ops->ccid_hc_rx_slab : |
| 225 | ccid_ops->ccid_hc_tx_slab, gfp); |
| 226 | if (ccid == NULL) |
| 227 | goto out_module_put; |
| 228 | ccid->ccid_ops = ccid_ops; |
| 229 | if (rx) { |
| 230 | memset(ccid + 1, 0, ccid_ops->ccid_hc_rx_obj_size); |
| 231 | if (ccid->ccid_ops->ccid_hc_rx_init != NULL && |
| 232 | ccid->ccid_ops->ccid_hc_rx_init(ccid, sk) != 0) |
| 233 | goto out_free_ccid; |
| 234 | } else { |
| 235 | memset(ccid + 1, 0, ccid_ops->ccid_hc_tx_obj_size); |
| 236 | if (ccid->ccid_ops->ccid_hc_tx_init != NULL && |
| 237 | ccid->ccid_ops->ccid_hc_tx_init(ccid, sk) != 0) |
| 238 | goto out_free_ccid; |
| 239 | } |
| 240 | out: |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 241 | return ccid; |
Arnaldo Carvalho de Melo | 91f0ebf | 2006-03-20 19:21:44 -0800 | [diff] [blame] | 242 | out_unlock: |
| 243 | ccids_read_unlock(); |
| 244 | goto out; |
| 245 | out_free_ccid: |
| 246 | kmem_cache_free(rx ? ccid_ops->ccid_hc_rx_slab : |
| 247 | ccid_ops->ccid_hc_tx_slab, ccid); |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 248 | ccid = NULL; |
Arnaldo Carvalho de Melo | 91f0ebf | 2006-03-20 19:21:44 -0800 | [diff] [blame] | 249 | out_module_put: |
| 250 | module_put(ccid_ops->ccid_owner); |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 251 | goto out; |
| 252 | } |
| 253 | |
Arnaldo Carvalho de Melo | 91f0ebf | 2006-03-20 19:21:44 -0800 | [diff] [blame] | 254 | EXPORT_SYMBOL_GPL(ccid_new); |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 255 | |
Arnaldo Carvalho de Melo | 91f0ebf | 2006-03-20 19:21:44 -0800 | [diff] [blame] | 256 | struct ccid *ccid_hc_rx_new(unsigned char id, struct sock *sk, gfp_t gfp) |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 257 | { |
Arnaldo Carvalho de Melo | 91f0ebf | 2006-03-20 19:21:44 -0800 | [diff] [blame] | 258 | return ccid_new(id, sk, 1, gfp); |
| 259 | } |
| 260 | |
| 261 | EXPORT_SYMBOL_GPL(ccid_hc_rx_new); |
| 262 | |
| 263 | struct ccid *ccid_hc_tx_new(unsigned char id,struct sock *sk, gfp_t gfp) |
| 264 | { |
| 265 | return ccid_new(id, sk, 0, gfp); |
| 266 | } |
| 267 | |
| 268 | EXPORT_SYMBOL_GPL(ccid_hc_tx_new); |
| 269 | |
| 270 | static void ccid_delete(struct ccid *ccid, struct sock *sk, int rx) |
| 271 | { |
| 272 | struct ccid_operations *ccid_ops; |
| 273 | |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 274 | if (ccid == NULL) |
| 275 | return; |
| 276 | |
Arnaldo Carvalho de Melo | 91f0ebf | 2006-03-20 19:21:44 -0800 | [diff] [blame] | 277 | ccid_ops = ccid->ccid_ops; |
| 278 | if (rx) { |
| 279 | if (ccid_ops->ccid_hc_rx_exit != NULL) |
| 280 | ccid_ops->ccid_hc_rx_exit(sk); |
| 281 | kmem_cache_free(ccid_ops->ccid_hc_rx_slab, ccid); |
| 282 | } else { |
| 283 | if (ccid_ops->ccid_hc_tx_exit != NULL) |
| 284 | ccid_ops->ccid_hc_tx_exit(sk); |
| 285 | kmem_cache_free(ccid_ops->ccid_hc_tx_slab, ccid); |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 286 | } |
Arnaldo Carvalho de Melo | 91f0ebf | 2006-03-20 19:21:44 -0800 | [diff] [blame] | 287 | ccids_read_lock(); |
| 288 | if (ccids[ccid_ops->ccid_id] != NULL) |
| 289 | module_put(ccid_ops->ccid_owner); |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 290 | ccids_read_unlock(); |
| 291 | } |
| 292 | |
Arnaldo Carvalho de Melo | 91f0ebf | 2006-03-20 19:21:44 -0800 | [diff] [blame] | 293 | void ccid_hc_rx_delete(struct ccid *ccid, struct sock *sk) |
| 294 | { |
| 295 | ccid_delete(ccid, sk, 1); |
| 296 | } |
| 297 | |
| 298 | EXPORT_SYMBOL_GPL(ccid_hc_rx_delete); |
| 299 | |
| 300 | void ccid_hc_tx_delete(struct ccid *ccid, struct sock *sk) |
| 301 | { |
| 302 | ccid_delete(ccid, sk, 0); |
| 303 | } |
| 304 | |
| 305 | EXPORT_SYMBOL_GPL(ccid_hc_tx_delete); |