Commit | Line | Data |
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7c657876 ACM |
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 | ||
ddebc973 GR |
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 | #ifdef ___OLD_INTERFACE_TO_BE_REMOVED___ | |
d90ebcbf GR |
80 | static u8 builtin_ccids[] = { |
81 | DCCPC_CCID2, /* CCID2 is supported by default */ | |
82 | #if defined(CONFIG_IP_DCCP_CCID3) || defined(CONFIG_IP_DCCP_CCID3_MODULE) | |
83 | DCCPC_CCID3, | |
84 | #endif | |
85 | }; | |
86 | ||
91f0ebf7 | 87 | static struct ccid_operations *ccids[CCID_MAX]; |
7c657876 ACM |
88 | #if defined(CONFIG_SMP) || defined(CONFIG_PREEMPT) |
89 | static atomic_t ccids_lockct = ATOMIC_INIT(0); | |
90 | static DEFINE_SPINLOCK(ccids_lock); | |
91 | ||
92 | /* | |
93 | * The strategy is: modifications ccids vector are short, do not sleep and | |
94 | * veeery rare, but read access should be free of any exclusive locks. | |
95 | */ | |
96 | static void ccids_write_lock(void) | |
97 | { | |
98 | spin_lock(&ccids_lock); | |
99 | while (atomic_read(&ccids_lockct) != 0) { | |
100 | spin_unlock(&ccids_lock); | |
101 | yield(); | |
102 | spin_lock(&ccids_lock); | |
103 | } | |
104 | } | |
105 | ||
106 | static inline void ccids_write_unlock(void) | |
107 | { | |
108 | spin_unlock(&ccids_lock); | |
109 | } | |
110 | ||
111 | static inline void ccids_read_lock(void) | |
112 | { | |
113 | atomic_inc(&ccids_lockct); | |
d725fdc8 | 114 | smp_mb__after_atomic_inc(); |
7c657876 ACM |
115 | spin_unlock_wait(&ccids_lock); |
116 | } | |
117 | ||
118 | static inline void ccids_read_unlock(void) | |
119 | { | |
120 | atomic_dec(&ccids_lockct); | |
121 | } | |
122 | ||
123 | #else | |
124 | #define ccids_write_lock() do { } while(0) | |
125 | #define ccids_write_unlock() do { } while(0) | |
126 | #define ccids_read_lock() do { } while(0) | |
127 | #define ccids_read_unlock() do { } while(0) | |
128 | #endif | |
ddebc973 | 129 | #endif /* ___OLD_INTERFACE_TO_BE_REMOVED___ */ |
7c657876 | 130 | |
e18b890b | 131 | static struct kmem_cache *ccid_kmem_cache_create(int obj_size, const char *fmt,...) |
7c657876 | 132 | { |
e18b890b | 133 | struct kmem_cache *slab; |
91f0ebf7 ACM |
134 | char slab_name_fmt[32], *slab_name; |
135 | va_list args; | |
136 | ||
137 | va_start(args, fmt); | |
138 | vsnprintf(slab_name_fmt, sizeof(slab_name_fmt), fmt, args); | |
139 | va_end(args); | |
140 | ||
141 | slab_name = kstrdup(slab_name_fmt, GFP_KERNEL); | |
142 | if (slab_name == NULL) | |
143 | return NULL; | |
144 | slab = kmem_cache_create(slab_name, sizeof(struct ccid) + obj_size, 0, | |
20c2df83 | 145 | SLAB_HWCACHE_ALIGN, NULL); |
91f0ebf7 ACM |
146 | if (slab == NULL) |
147 | kfree(slab_name); | |
148 | return slab; | |
149 | } | |
150 | ||
e18b890b | 151 | static void ccid_kmem_cache_destroy(struct kmem_cache *slab) |
91f0ebf7 ACM |
152 | { |
153 | if (slab != NULL) { | |
154 | const char *name = kmem_cache_name(slab); | |
155 | ||
156 | kmem_cache_destroy(slab); | |
157 | kfree(name); | |
158 | } | |
159 | } | |
160 | ||
ddebc973 | 161 | #ifdef ___OLD_INTERFACE_TO_BE_REMOVED___ |
d90ebcbf GR |
162 | /* check that up to @array_len members in @ccid_array are supported */ |
163 | bool ccid_support_check(u8 const *ccid_array, u8 array_len) | |
164 | { | |
165 | u8 i, j, found; | |
166 | ||
167 | for (i = 0, found = 0; i < array_len; i++, found = 0) { | |
168 | for (j = 0; !found && j < ARRAY_SIZE(builtin_ccids); j++) | |
169 | found = (ccid_array[i] == builtin_ccids[j]); | |
170 | if (!found) | |
171 | return false; | |
172 | } | |
173 | return true; | |
174 | } | |
175 | ||
176 | /** | |
177 | * ccid_get_builtin_ccids - Provide copy of `builtin' CCID array | |
178 | * @ccid_array: pointer to copy into | |
179 | * @array_len: value to return length into | |
180 | * This function allocates memory - caller must see that it is freed after use. | |
181 | */ | |
182 | int ccid_get_builtin_ccids(u8 **ccid_array, u8 *array_len) | |
183 | { | |
184 | *ccid_array = kmemdup(builtin_ccids, sizeof(builtin_ccids), gfp_any()); | |
185 | if (*ccid_array == NULL) | |
186 | return -ENOBUFS; | |
187 | *array_len = ARRAY_SIZE(builtin_ccids); | |
188 | return 0; | |
189 | } | |
190 | ||
191 | int ccid_getsockopt_builtin_ccids(struct sock *sk, int len, | |
192 | char __user *optval, int __user *optlen) | |
193 | { | |
194 | if (len < sizeof(builtin_ccids)) | |
195 | return -EINVAL; | |
196 | ||
197 | if (put_user(sizeof(builtin_ccids), optlen) || | |
198 | copy_to_user(optval, builtin_ccids, sizeof(builtin_ccids))) | |
199 | return -EFAULT; | |
200 | return 0; | |
201 | } | |
ddebc973 | 202 | #endif /* ___OLD_INTERFACE_TO_BE_REMOVED___ */ |
d90ebcbf | 203 | |
ddebc973 | 204 | static int ccid_activate(struct ccid_operations *ccid_ops) |
91f0ebf7 ACM |
205 | { |
206 | int err = -ENOBUFS; | |
207 | ||
208 | ccid_ops->ccid_hc_rx_slab = | |
209 | ccid_kmem_cache_create(ccid_ops->ccid_hc_rx_obj_size, | |
84a97b0a GR |
210 | "ccid%u_hc_rx_sock", |
211 | ccid_ops->ccid_id); | |
91f0ebf7 ACM |
212 | if (ccid_ops->ccid_hc_rx_slab == NULL) |
213 | goto out; | |
214 | ||
215 | ccid_ops->ccid_hc_tx_slab = | |
216 | ccid_kmem_cache_create(ccid_ops->ccid_hc_tx_obj_size, | |
84a97b0a GR |
217 | "ccid%u_hc_tx_sock", |
218 | ccid_ops->ccid_id); | |
91f0ebf7 ACM |
219 | if (ccid_ops->ccid_hc_tx_slab == NULL) |
220 | goto out_free_rx_slab; | |
7c657876 | 221 | |
ddebc973 | 222 | pr_info("CCID: Activated CCID %d (%s)\n", |
91f0ebf7 | 223 | ccid_ops->ccid_id, ccid_ops->ccid_name); |
ddebc973 | 224 | err = 0; |
91f0ebf7 | 225 | out: |
7c657876 | 226 | return err; |
91f0ebf7 ACM |
227 | out_free_rx_slab: |
228 | ccid_kmem_cache_destroy(ccid_ops->ccid_hc_rx_slab); | |
229 | ccid_ops->ccid_hc_rx_slab = NULL; | |
230 | goto out; | |
7c657876 ACM |
231 | } |
232 | ||
ddebc973 | 233 | static void ccid_deactivate(struct ccid_operations *ccid_ops) |
7c657876 | 234 | { |
91f0ebf7 ACM |
235 | ccid_kmem_cache_destroy(ccid_ops->ccid_hc_tx_slab); |
236 | ccid_ops->ccid_hc_tx_slab = NULL; | |
237 | ccid_kmem_cache_destroy(ccid_ops->ccid_hc_rx_slab); | |
238 | ccid_ops->ccid_hc_rx_slab = NULL; | |
239 | ||
ddebc973 | 240 | pr_info("CCID: Deactivated CCID %d (%s)\n", |
91f0ebf7 | 241 | ccid_ops->ccid_id, ccid_ops->ccid_name); |
7c657876 ACM |
242 | } |
243 | ||
91f0ebf7 | 244 | struct ccid *ccid_new(unsigned char id, struct sock *sk, int rx, gfp_t gfp) |
7c657876 | 245 | { |
ddebc973 | 246 | struct ccid_operations *ccid_ops = ccid_by_number(id); |
91f0ebf7 | 247 | struct ccid *ccid = NULL; |
7c657876 | 248 | |
91f0ebf7 | 249 | if (ccid_ops == NULL) |
ddebc973 | 250 | goto out; |
7c657876 | 251 | |
91f0ebf7 ACM |
252 | ccid = kmem_cache_alloc(rx ? ccid_ops->ccid_hc_rx_slab : |
253 | ccid_ops->ccid_hc_tx_slab, gfp); | |
254 | if (ccid == NULL) | |
ddebc973 | 255 | goto out; |
91f0ebf7 ACM |
256 | ccid->ccid_ops = ccid_ops; |
257 | if (rx) { | |
258 | memset(ccid + 1, 0, ccid_ops->ccid_hc_rx_obj_size); | |
259 | if (ccid->ccid_ops->ccid_hc_rx_init != NULL && | |
260 | ccid->ccid_ops->ccid_hc_rx_init(ccid, sk) != 0) | |
261 | goto out_free_ccid; | |
262 | } else { | |
263 | memset(ccid + 1, 0, ccid_ops->ccid_hc_tx_obj_size); | |
264 | if (ccid->ccid_ops->ccid_hc_tx_init != NULL && | |
265 | ccid->ccid_ops->ccid_hc_tx_init(ccid, sk) != 0) | |
266 | goto out_free_ccid; | |
267 | } | |
7c657876 | 268 | out: |
7c657876 | 269 | return ccid; |
91f0ebf7 ACM |
270 | out_free_ccid: |
271 | kmem_cache_free(rx ? ccid_ops->ccid_hc_rx_slab : | |
272 | ccid_ops->ccid_hc_tx_slab, ccid); | |
7c657876 ACM |
273 | ccid = NULL; |
274 | goto out; | |
275 | } | |
276 | ||
91f0ebf7 | 277 | EXPORT_SYMBOL_GPL(ccid_new); |
7c657876 | 278 | |
91f0ebf7 ACM |
279 | static void ccid_delete(struct ccid *ccid, struct sock *sk, int rx) |
280 | { | |
281 | struct ccid_operations *ccid_ops; | |
282 | ||
7c657876 ACM |
283 | if (ccid == NULL) |
284 | return; | |
285 | ||
91f0ebf7 ACM |
286 | ccid_ops = ccid->ccid_ops; |
287 | if (rx) { | |
288 | if (ccid_ops->ccid_hc_rx_exit != NULL) | |
289 | ccid_ops->ccid_hc_rx_exit(sk); | |
290 | kmem_cache_free(ccid_ops->ccid_hc_rx_slab, ccid); | |
291 | } else { | |
292 | if (ccid_ops->ccid_hc_tx_exit != NULL) | |
293 | ccid_ops->ccid_hc_tx_exit(sk); | |
294 | kmem_cache_free(ccid_ops->ccid_hc_tx_slab, ccid); | |
295 | } | |
91f0ebf7 | 296 | } |
7c657876 | 297 | |
91f0ebf7 ACM |
298 | void ccid_hc_rx_delete(struct ccid *ccid, struct sock *sk) |
299 | { | |
300 | ccid_delete(ccid, sk, 1); | |
301 | } | |
7c657876 | 302 | |
91f0ebf7 ACM |
303 | EXPORT_SYMBOL_GPL(ccid_hc_rx_delete); |
304 | ||
305 | void ccid_hc_tx_delete(struct ccid *ccid, struct sock *sk) | |
306 | { | |
307 | ccid_delete(ccid, sk, 0); | |
7c657876 ACM |
308 | } |
309 | ||
91f0ebf7 | 310 | EXPORT_SYMBOL_GPL(ccid_hc_tx_delete); |
ddebc973 GR |
311 | |
312 | int __init ccid_initialize_builtins(void) | |
313 | { | |
314 | int i, err; | |
315 | ||
316 | for (i = 0; i < ARRAY_SIZE(ccids); i++) { | |
317 | err = ccid_activate(ccids[i]); | |
318 | if (err) | |
319 | goto unwind_registrations; | |
320 | } | |
321 | return 0; | |
322 | ||
323 | unwind_registrations: | |
324 | while(--i >= 0) | |
325 | ccid_deactivate(ccids[i]); | |
326 | return err; | |
327 | } | |
328 | ||
329 | void ccid_cleanup_builtins(void) | |
330 | { | |
331 | int i; | |
332 | ||
333 | for (i = 0; i < ARRAY_SIZE(ccids); i++) | |
334 | ccid_deactivate(ccids[i]); | |
335 | } |