Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * Linux Socket Filter - Kernel level socket filtering | |
3 | * | |
4 | * Author: | |
5 | * Jay Schulist <jschlst@samba.org> | |
6 | * | |
7 | * Based on the design of: | |
8 | * - The Berkeley Packet Filter | |
9 | * | |
10 | * This program is free software; you can redistribute it and/or | |
11 | * modify it under the terms of the GNU General Public License | |
12 | * as published by the Free Software Foundation; either version | |
13 | * 2 of the License, or (at your option) any later version. | |
14 | * | |
15 | * Andi Kleen - Fix a few bad bugs and races. | |
93699863 | 16 | * Kris Katterjohn - Added many additional checks in sk_chk_filter() |
1da177e4 LT |
17 | */ |
18 | ||
19 | #include <linux/module.h> | |
20 | #include <linux/types.h> | |
1da177e4 LT |
21 | #include <linux/mm.h> |
22 | #include <linux/fcntl.h> | |
23 | #include <linux/socket.h> | |
24 | #include <linux/in.h> | |
25 | #include <linux/inet.h> | |
26 | #include <linux/netdevice.h> | |
27 | #include <linux/if_packet.h> | |
5a0e3ad6 | 28 | #include <linux/gfp.h> |
1da177e4 LT |
29 | #include <net/ip.h> |
30 | #include <net/protocol.h> | |
4738c1db | 31 | #include <net/netlink.h> |
1da177e4 LT |
32 | #include <linux/skbuff.h> |
33 | #include <net/sock.h> | |
34 | #include <linux/errno.h> | |
35 | #include <linux/timer.h> | |
1da177e4 | 36 | #include <asm/uaccess.h> |
40daafc8 | 37 | #include <asm/unaligned.h> |
1da177e4 | 38 | #include <linux/filter.h> |
86e4ca66 | 39 | #include <linux/ratelimit.h> |
46b325c7 | 40 | #include <linux/seccomp.h> |
f3335031 | 41 | #include <linux/if_vlan.h> |
1da177e4 | 42 | |
f03fb3f4 JS |
43 | /* No hurry in this branch |
44 | * | |
45 | * Exported for the bpf jit load helper. | |
46 | */ | |
47 | void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb, int k, unsigned int size) | |
1da177e4 LT |
48 | { |
49 | u8 *ptr = NULL; | |
50 | ||
51 | if (k >= SKF_NET_OFF) | |
d56f90a7 | 52 | ptr = skb_network_header(skb) + k - SKF_NET_OFF; |
1da177e4 | 53 | else if (k >= SKF_LL_OFF) |
98e399f8 | 54 | ptr = skb_mac_header(skb) + k - SKF_LL_OFF; |
1da177e4 | 55 | |
4bc65dd8 | 56 | if (ptr >= skb->head && ptr + size <= skb_tail_pointer(skb)) |
1da177e4 LT |
57 | return ptr; |
58 | return NULL; | |
59 | } | |
60 | ||
62ab0812 | 61 | static inline void *load_pointer(const struct sk_buff *skb, int k, |
4ec93edb | 62 | unsigned int size, void *buffer) |
0b05b2a4 PM |
63 | { |
64 | if (k >= 0) | |
65 | return skb_header_pointer(skb, k, size, buffer); | |
f03fb3f4 | 66 | return bpf_internal_load_pointer_neg_helper(skb, k, size); |
0b05b2a4 PM |
67 | } |
68 | ||
43db6d65 | 69 | /** |
56325d9f | 70 | * sk_filter_trim_cap - run a packet through a socket filter |
43db6d65 SH |
71 | * @sk: sock associated with &sk_buff |
72 | * @skb: buffer to filter | |
56325d9f | 73 | * @cap: limit on how short the eBPF program may trim the packet |
43db6d65 SH |
74 | * |
75 | * Run the filter code and then cut skb->data to correct size returned by | |
76 | * sk_run_filter. If pkt_len is 0 we toss packet. If skb->len is smaller | |
77 | * than pkt_len we keep whole skb->data. This is the socket level | |
78 | * wrapper to sk_run_filter. It returns 0 if the packet should | |
79 | * be accepted or -EPERM if the packet should be tossed. | |
80 | * | |
81 | */ | |
56325d9f | 82 | int sk_filter_trim_cap(struct sock *sk, struct sk_buff *skb, unsigned int cap) |
43db6d65 SH |
83 | { |
84 | int err; | |
85 | struct sk_filter *filter; | |
86 | ||
c93bdd0e MG |
87 | /* |
88 | * If the skb was allocated from pfmemalloc reserves, only | |
89 | * allow SOCK_MEMALLOC sockets to use it as this socket is | |
90 | * helping free memory | |
91 | */ | |
92 | if (skb_pfmemalloc(skb) && !sock_flag(sk, SOCK_MEMALLOC)) | |
93 | return -ENOMEM; | |
94 | ||
43db6d65 SH |
95 | err = security_sock_rcv_skb(sk, skb); |
96 | if (err) | |
97 | return err; | |
98 | ||
80f8f102 ED |
99 | rcu_read_lock(); |
100 | filter = rcu_dereference(sk->sk_filter); | |
43db6d65 | 101 | if (filter) { |
0a14842f | 102 | unsigned int pkt_len = SK_RUN_FILTER(filter, skb); |
56325d9f | 103 | err = pkt_len ? pskb_trim(skb, max(cap, pkt_len)) : -EPERM; |
43db6d65 | 104 | } |
80f8f102 | 105 | rcu_read_unlock(); |
43db6d65 SH |
106 | |
107 | return err; | |
108 | } | |
56325d9f | 109 | EXPORT_SYMBOL(sk_filter_trim_cap); |
43db6d65 | 110 | |
1da177e4 | 111 | /** |
2966b66c | 112 | * sk_run_filter - run a filter on a socket |
1da177e4 | 113 | * @skb: buffer to run the filter on |
697d0e33 | 114 | * @fentry: filter to apply |
1da177e4 LT |
115 | * |
116 | * Decode and apply filter instructions to the skb->data. | |
93aaae2e ED |
117 | * Return length to keep, 0 for none. @skb is the data we are |
118 | * filtering, @filter is the array of filter instructions. | |
119 | * Because all jumps are guaranteed to be before last instruction, | |
120 | * and last instruction guaranteed to be a RET, we dont need to check | |
121 | * flen. (We used to pass to this function the length of filter) | |
1da177e4 | 122 | */ |
62ab0812 ED |
123 | unsigned int sk_run_filter(const struct sk_buff *skb, |
124 | const struct sock_filter *fentry) | |
1da177e4 | 125 | { |
0b05b2a4 | 126 | void *ptr; |
2966b66c KK |
127 | u32 A = 0; /* Accumulator */ |
128 | u32 X = 0; /* Index Register */ | |
1da177e4 | 129 | u32 mem[BPF_MEMWORDS]; /* Scratch Memory Store */ |
0b05b2a4 | 130 | u32 tmp; |
1da177e4 | 131 | int k; |
1da177e4 LT |
132 | |
133 | /* | |
134 | * Process array of filter instructions. | |
135 | */ | |
93aaae2e ED |
136 | for (;; fentry++) { |
137 | #if defined(CONFIG_X86_32) | |
138 | #define K (fentry->k) | |
139 | #else | |
140 | const u32 K = fentry->k; | |
141 | #endif | |
4ec93edb | 142 | |
1da177e4 | 143 | switch (fentry->code) { |
01f2f3f6 | 144 | case BPF_S_ALU_ADD_X: |
1da177e4 LT |
145 | A += X; |
146 | continue; | |
01f2f3f6 | 147 | case BPF_S_ALU_ADD_K: |
93aaae2e | 148 | A += K; |
1da177e4 | 149 | continue; |
01f2f3f6 | 150 | case BPF_S_ALU_SUB_X: |
1da177e4 LT |
151 | A -= X; |
152 | continue; | |
01f2f3f6 | 153 | case BPF_S_ALU_SUB_K: |
93aaae2e | 154 | A -= K; |
1da177e4 | 155 | continue; |
01f2f3f6 | 156 | case BPF_S_ALU_MUL_X: |
1da177e4 LT |
157 | A *= X; |
158 | continue; | |
01f2f3f6 | 159 | case BPF_S_ALU_MUL_K: |
93aaae2e | 160 | A *= K; |
1da177e4 | 161 | continue; |
01f2f3f6 | 162 | case BPF_S_ALU_DIV_X: |
1da177e4 LT |
163 | if (X == 0) |
164 | return 0; | |
165 | A /= X; | |
166 | continue; | |
01f2f3f6 | 167 | case BPF_S_ALU_DIV_K: |
cd7361dc | 168 | A /= K; |
1da177e4 | 169 | continue; |
b6069a95 ED |
170 | case BPF_S_ALU_MOD_X: |
171 | if (X == 0) | |
172 | return 0; | |
173 | A %= X; | |
174 | continue; | |
175 | case BPF_S_ALU_MOD_K: | |
176 | A %= K; | |
177 | continue; | |
01f2f3f6 | 178 | case BPF_S_ALU_AND_X: |
1da177e4 LT |
179 | A &= X; |
180 | continue; | |
01f2f3f6 | 181 | case BPF_S_ALU_AND_K: |
93aaae2e | 182 | A &= K; |
1da177e4 | 183 | continue; |
01f2f3f6 | 184 | case BPF_S_ALU_OR_X: |
1da177e4 LT |
185 | A |= X; |
186 | continue; | |
01f2f3f6 | 187 | case BPF_S_ALU_OR_K: |
93aaae2e | 188 | A |= K; |
1da177e4 | 189 | continue; |
9e49e889 DB |
190 | case BPF_S_ANC_ALU_XOR_X: |
191 | case BPF_S_ALU_XOR_X: | |
192 | A ^= X; | |
193 | continue; | |
194 | case BPF_S_ALU_XOR_K: | |
195 | A ^= K; | |
196 | continue; | |
01f2f3f6 | 197 | case BPF_S_ALU_LSH_X: |
1da177e4 LT |
198 | A <<= X; |
199 | continue; | |
01f2f3f6 | 200 | case BPF_S_ALU_LSH_K: |
93aaae2e | 201 | A <<= K; |
1da177e4 | 202 | continue; |
01f2f3f6 | 203 | case BPF_S_ALU_RSH_X: |
1da177e4 LT |
204 | A >>= X; |
205 | continue; | |
01f2f3f6 | 206 | case BPF_S_ALU_RSH_K: |
93aaae2e | 207 | A >>= K; |
1da177e4 | 208 | continue; |
01f2f3f6 | 209 | case BPF_S_ALU_NEG: |
1da177e4 LT |
210 | A = -A; |
211 | continue; | |
01f2f3f6 | 212 | case BPF_S_JMP_JA: |
93aaae2e | 213 | fentry += K; |
1da177e4 | 214 | continue; |
01f2f3f6 | 215 | case BPF_S_JMP_JGT_K: |
93aaae2e | 216 | fentry += (A > K) ? fentry->jt : fentry->jf; |
1da177e4 | 217 | continue; |
01f2f3f6 | 218 | case BPF_S_JMP_JGE_K: |
93aaae2e | 219 | fentry += (A >= K) ? fentry->jt : fentry->jf; |
1da177e4 | 220 | continue; |
01f2f3f6 | 221 | case BPF_S_JMP_JEQ_K: |
93aaae2e | 222 | fentry += (A == K) ? fentry->jt : fentry->jf; |
1da177e4 | 223 | continue; |
01f2f3f6 | 224 | case BPF_S_JMP_JSET_K: |
93aaae2e | 225 | fentry += (A & K) ? fentry->jt : fentry->jf; |
1da177e4 | 226 | continue; |
01f2f3f6 | 227 | case BPF_S_JMP_JGT_X: |
93aaae2e | 228 | fentry += (A > X) ? fentry->jt : fentry->jf; |
1da177e4 | 229 | continue; |
01f2f3f6 | 230 | case BPF_S_JMP_JGE_X: |
93aaae2e | 231 | fentry += (A >= X) ? fentry->jt : fentry->jf; |
1da177e4 | 232 | continue; |
01f2f3f6 | 233 | case BPF_S_JMP_JEQ_X: |
93aaae2e | 234 | fentry += (A == X) ? fentry->jt : fentry->jf; |
1da177e4 | 235 | continue; |
01f2f3f6 | 236 | case BPF_S_JMP_JSET_X: |
93aaae2e | 237 | fentry += (A & X) ? fentry->jt : fentry->jf; |
1da177e4 | 238 | continue; |
01f2f3f6 | 239 | case BPF_S_LD_W_ABS: |
93aaae2e | 240 | k = K; |
e35bedf3 | 241 | load_w: |
0b05b2a4 PM |
242 | ptr = load_pointer(skb, k, 4, &tmp); |
243 | if (ptr != NULL) { | |
d3e2ce3b | 244 | A = get_unaligned_be32(ptr); |
0b05b2a4 | 245 | continue; |
1da177e4 | 246 | } |
12b16dad | 247 | return 0; |
01f2f3f6 | 248 | case BPF_S_LD_H_ABS: |
93aaae2e | 249 | k = K; |
e35bedf3 | 250 | load_h: |
0b05b2a4 PM |
251 | ptr = load_pointer(skb, k, 2, &tmp); |
252 | if (ptr != NULL) { | |
d3e2ce3b | 253 | A = get_unaligned_be16(ptr); |
0b05b2a4 | 254 | continue; |
1da177e4 | 255 | } |
12b16dad | 256 | return 0; |
01f2f3f6 | 257 | case BPF_S_LD_B_ABS: |
93aaae2e | 258 | k = K; |
1da177e4 | 259 | load_b: |
0b05b2a4 PM |
260 | ptr = load_pointer(skb, k, 1, &tmp); |
261 | if (ptr != NULL) { | |
262 | A = *(u8 *)ptr; | |
263 | continue; | |
1da177e4 | 264 | } |
12b16dad | 265 | return 0; |
01f2f3f6 | 266 | case BPF_S_LD_W_LEN: |
3154e540 | 267 | A = skb->len; |
1da177e4 | 268 | continue; |
01f2f3f6 | 269 | case BPF_S_LDX_W_LEN: |
3154e540 | 270 | X = skb->len; |
1da177e4 | 271 | continue; |
01f2f3f6 | 272 | case BPF_S_LD_W_IND: |
93aaae2e | 273 | k = X + K; |
1da177e4 | 274 | goto load_w; |
01f2f3f6 | 275 | case BPF_S_LD_H_IND: |
93aaae2e | 276 | k = X + K; |
1da177e4 | 277 | goto load_h; |
01f2f3f6 | 278 | case BPF_S_LD_B_IND: |
93aaae2e | 279 | k = X + K; |
1da177e4 | 280 | goto load_b; |
01f2f3f6 | 281 | case BPF_S_LDX_B_MSH: |
93aaae2e | 282 | ptr = load_pointer(skb, K, 1, &tmp); |
0b05b2a4 PM |
283 | if (ptr != NULL) { |
284 | X = (*(u8 *)ptr & 0xf) << 2; | |
285 | continue; | |
286 | } | |
287 | return 0; | |
01f2f3f6 | 288 | case BPF_S_LD_IMM: |
93aaae2e | 289 | A = K; |
1da177e4 | 290 | continue; |
01f2f3f6 | 291 | case BPF_S_LDX_IMM: |
93aaae2e | 292 | X = K; |
1da177e4 | 293 | continue; |
01f2f3f6 | 294 | case BPF_S_LD_MEM: |
2d5311e4 | 295 | A = mem[K]; |
1da177e4 | 296 | continue; |
01f2f3f6 | 297 | case BPF_S_LDX_MEM: |
2d5311e4 | 298 | X = mem[K]; |
1da177e4 | 299 | continue; |
01f2f3f6 | 300 | case BPF_S_MISC_TAX: |
1da177e4 LT |
301 | X = A; |
302 | continue; | |
01f2f3f6 | 303 | case BPF_S_MISC_TXA: |
1da177e4 LT |
304 | A = X; |
305 | continue; | |
01f2f3f6 | 306 | case BPF_S_RET_K: |
93aaae2e | 307 | return K; |
01f2f3f6 | 308 | case BPF_S_RET_A: |
4bad4dc9 | 309 | return A; |
01f2f3f6 | 310 | case BPF_S_ST: |
93aaae2e | 311 | mem[K] = A; |
1da177e4 | 312 | continue; |
01f2f3f6 | 313 | case BPF_S_STX: |
93aaae2e | 314 | mem[K] = X; |
1da177e4 | 315 | continue; |
12b16dad | 316 | case BPF_S_ANC_PROTOCOL: |
252e3346 | 317 | A = ntohs(skb->protocol); |
1da177e4 | 318 | continue; |
12b16dad | 319 | case BPF_S_ANC_PKTTYPE: |
1da177e4 LT |
320 | A = skb->pkt_type; |
321 | continue; | |
12b16dad | 322 | case BPF_S_ANC_IFINDEX: |
40eaf962 PLE |
323 | if (!skb->dev) |
324 | return 0; | |
1da177e4 LT |
325 | A = skb->dev->ifindex; |
326 | continue; | |
12b16dad | 327 | case BPF_S_ANC_MARK: |
7e75f93e | 328 | A = skb->mark; |
329 | continue; | |
12b16dad | 330 | case BPF_S_ANC_QUEUE: |
d19742fb ED |
331 | A = skb->queue_mapping; |
332 | continue; | |
12b16dad | 333 | case BPF_S_ANC_HATYPE: |
40eaf962 PLE |
334 | if (!skb->dev) |
335 | return 0; | |
336 | A = skb->dev->type; | |
337 | continue; | |
12b16dad | 338 | case BPF_S_ANC_RXHASH: |
da2033c2 ED |
339 | A = skb->rxhash; |
340 | continue; | |
12b16dad | 341 | case BPF_S_ANC_CPU: |
da2033c2 ED |
342 | A = raw_smp_processor_id(); |
343 | continue; | |
f3335031 ED |
344 | case BPF_S_ANC_VLAN_TAG: |
345 | A = vlan_tx_tag_get(skb); | |
346 | continue; | |
347 | case BPF_S_ANC_VLAN_TAG_PRESENT: | |
348 | A = !!vlan_tx_tag_present(skb); | |
349 | continue; | |
3e5289d5 DB |
350 | case BPF_S_ANC_PAY_OFFSET: |
351 | A = __skb_get_poff(skb); | |
352 | continue; | |
12b16dad | 353 | case BPF_S_ANC_NLATTR: { |
4738c1db PM |
354 | struct nlattr *nla; |
355 | ||
356 | if (skb_is_nonlinear(skb)) | |
357 | return 0; | |
314760e6 MK |
358 | if (skb->len < sizeof(struct nlattr)) |
359 | return 0; | |
4738c1db PM |
360 | if (A > skb->len - sizeof(struct nlattr)) |
361 | return 0; | |
362 | ||
363 | nla = nla_find((struct nlattr *)&skb->data[A], | |
364 | skb->len - A, X); | |
365 | if (nla) | |
366 | A = (void *)nla - (void *)skb->data; | |
367 | else | |
368 | A = 0; | |
369 | continue; | |
370 | } | |
12b16dad | 371 | case BPF_S_ANC_NLATTR_NEST: { |
d214c753 PNA |
372 | struct nlattr *nla; |
373 | ||
374 | if (skb_is_nonlinear(skb)) | |
375 | return 0; | |
314760e6 MK |
376 | if (skb->len < sizeof(struct nlattr)) |
377 | return 0; | |
d214c753 PNA |
378 | if (A > skb->len - sizeof(struct nlattr)) |
379 | return 0; | |
380 | ||
381 | nla = (struct nlattr *)&skb->data[A]; | |
314760e6 | 382 | if (nla->nla_len > skb->len - A) |
d214c753 PNA |
383 | return 0; |
384 | ||
385 | nla = nla_find_nested(nla, X); | |
386 | if (nla) | |
387 | A = (void *)nla - (void *)skb->data; | |
388 | else | |
389 | A = 0; | |
390 | continue; | |
391 | } | |
46b325c7 WD |
392 | #ifdef CONFIG_SECCOMP_FILTER |
393 | case BPF_S_ANC_SECCOMP_LD_W: | |
394 | A = seccomp_bpf_load(fentry->k); | |
395 | continue; | |
396 | #endif | |
1da177e4 | 397 | default: |
6c4a5cb2 JP |
398 | WARN_RATELIMIT(1, "Unknown code:%u jt:%u tf:%u k:%u\n", |
399 | fentry->code, fentry->jt, | |
400 | fentry->jf, fentry->k); | |
1da177e4 LT |
401 | return 0; |
402 | } | |
403 | } | |
404 | ||
405 | return 0; | |
406 | } | |
b715631f | 407 | EXPORT_SYMBOL(sk_run_filter); |
1da177e4 | 408 | |
2d5311e4 ED |
409 | /* |
410 | * Security : | |
411 | * A BPF program is able to use 16 cells of memory to store intermediate | |
412 | * values (check u32 mem[BPF_MEMWORDS] in sk_run_filter()) | |
413 | * As we dont want to clear mem[] array for each packet going through | |
414 | * sk_run_filter(), we check that filter loaded by user never try to read | |
415 | * a cell if not previously written, and we check all branches to be sure | |
25985edc | 416 | * a malicious user doesn't try to abuse us. |
2d5311e4 ED |
417 | */ |
418 | static int check_load_and_stores(struct sock_filter *filter, int flen) | |
419 | { | |
420 | u16 *masks, memvalid = 0; /* one bit per cell, 16 cells */ | |
421 | int pc, ret = 0; | |
422 | ||
423 | BUILD_BUG_ON(BPF_MEMWORDS > 16); | |
424 | masks = kmalloc(flen * sizeof(*masks), GFP_KERNEL); | |
425 | if (!masks) | |
426 | return -ENOMEM; | |
427 | memset(masks, 0xff, flen * sizeof(*masks)); | |
428 | ||
429 | for (pc = 0; pc < flen; pc++) { | |
430 | memvalid &= masks[pc]; | |
431 | ||
432 | switch (filter[pc].code) { | |
433 | case BPF_S_ST: | |
434 | case BPF_S_STX: | |
435 | memvalid |= (1 << filter[pc].k); | |
436 | break; | |
437 | case BPF_S_LD_MEM: | |
438 | case BPF_S_LDX_MEM: | |
439 | if (!(memvalid & (1 << filter[pc].k))) { | |
440 | ret = -EINVAL; | |
441 | goto error; | |
442 | } | |
443 | break; | |
444 | case BPF_S_JMP_JA: | |
445 | /* a jump must set masks on target */ | |
446 | masks[pc + 1 + filter[pc].k] &= memvalid; | |
447 | memvalid = ~0; | |
448 | break; | |
449 | case BPF_S_JMP_JEQ_K: | |
450 | case BPF_S_JMP_JEQ_X: | |
451 | case BPF_S_JMP_JGE_K: | |
452 | case BPF_S_JMP_JGE_X: | |
453 | case BPF_S_JMP_JGT_K: | |
454 | case BPF_S_JMP_JGT_X: | |
455 | case BPF_S_JMP_JSET_X: | |
456 | case BPF_S_JMP_JSET_K: | |
457 | /* a jump must set masks on targets */ | |
458 | masks[pc + 1 + filter[pc].jt] &= memvalid; | |
459 | masks[pc + 1 + filter[pc].jf] &= memvalid; | |
460 | memvalid = ~0; | |
461 | break; | |
462 | } | |
463 | } | |
464 | error: | |
465 | kfree(masks); | |
466 | return ret; | |
467 | } | |
468 | ||
1da177e4 LT |
469 | /** |
470 | * sk_chk_filter - verify socket filter code | |
471 | * @filter: filter to verify | |
472 | * @flen: length of filter | |
473 | * | |
474 | * Check the user's filter code. If we let some ugly | |
475 | * filter code slip through kaboom! The filter must contain | |
93699863 KK |
476 | * no references or jumps that are out of range, no illegal |
477 | * instructions, and must end with a RET instruction. | |
1da177e4 | 478 | * |
7b11f69f KK |
479 | * All jumps are forward as they are not signed. |
480 | * | |
481 | * Returns 0 if the rule set is legal or -EINVAL if not. | |
1da177e4 | 482 | */ |
4f25af27 | 483 | int sk_chk_filter(struct sock_filter *filter, unsigned int flen) |
1da177e4 | 484 | { |
cba328fc TH |
485 | /* |
486 | * Valid instructions are initialized to non-0. | |
487 | * Invalid instructions are initialized to 0. | |
488 | */ | |
489 | static const u8 codes[] = { | |
8c1592d6 ED |
490 | [BPF_ALU|BPF_ADD|BPF_K] = BPF_S_ALU_ADD_K, |
491 | [BPF_ALU|BPF_ADD|BPF_X] = BPF_S_ALU_ADD_X, | |
492 | [BPF_ALU|BPF_SUB|BPF_K] = BPF_S_ALU_SUB_K, | |
493 | [BPF_ALU|BPF_SUB|BPF_X] = BPF_S_ALU_SUB_X, | |
494 | [BPF_ALU|BPF_MUL|BPF_K] = BPF_S_ALU_MUL_K, | |
495 | [BPF_ALU|BPF_MUL|BPF_X] = BPF_S_ALU_MUL_X, | |
496 | [BPF_ALU|BPF_DIV|BPF_X] = BPF_S_ALU_DIV_X, | |
b6069a95 ED |
497 | [BPF_ALU|BPF_MOD|BPF_K] = BPF_S_ALU_MOD_K, |
498 | [BPF_ALU|BPF_MOD|BPF_X] = BPF_S_ALU_MOD_X, | |
8c1592d6 ED |
499 | [BPF_ALU|BPF_AND|BPF_K] = BPF_S_ALU_AND_K, |
500 | [BPF_ALU|BPF_AND|BPF_X] = BPF_S_ALU_AND_X, | |
501 | [BPF_ALU|BPF_OR|BPF_K] = BPF_S_ALU_OR_K, | |
502 | [BPF_ALU|BPF_OR|BPF_X] = BPF_S_ALU_OR_X, | |
9e49e889 DB |
503 | [BPF_ALU|BPF_XOR|BPF_K] = BPF_S_ALU_XOR_K, |
504 | [BPF_ALU|BPF_XOR|BPF_X] = BPF_S_ALU_XOR_X, | |
8c1592d6 ED |
505 | [BPF_ALU|BPF_LSH|BPF_K] = BPF_S_ALU_LSH_K, |
506 | [BPF_ALU|BPF_LSH|BPF_X] = BPF_S_ALU_LSH_X, | |
507 | [BPF_ALU|BPF_RSH|BPF_K] = BPF_S_ALU_RSH_K, | |
508 | [BPF_ALU|BPF_RSH|BPF_X] = BPF_S_ALU_RSH_X, | |
509 | [BPF_ALU|BPF_NEG] = BPF_S_ALU_NEG, | |
510 | [BPF_LD|BPF_W|BPF_ABS] = BPF_S_LD_W_ABS, | |
511 | [BPF_LD|BPF_H|BPF_ABS] = BPF_S_LD_H_ABS, | |
512 | [BPF_LD|BPF_B|BPF_ABS] = BPF_S_LD_B_ABS, | |
513 | [BPF_LD|BPF_W|BPF_LEN] = BPF_S_LD_W_LEN, | |
514 | [BPF_LD|BPF_W|BPF_IND] = BPF_S_LD_W_IND, | |
515 | [BPF_LD|BPF_H|BPF_IND] = BPF_S_LD_H_IND, | |
516 | [BPF_LD|BPF_B|BPF_IND] = BPF_S_LD_B_IND, | |
517 | [BPF_LD|BPF_IMM] = BPF_S_LD_IMM, | |
518 | [BPF_LDX|BPF_W|BPF_LEN] = BPF_S_LDX_W_LEN, | |
519 | [BPF_LDX|BPF_B|BPF_MSH] = BPF_S_LDX_B_MSH, | |
520 | [BPF_LDX|BPF_IMM] = BPF_S_LDX_IMM, | |
521 | [BPF_MISC|BPF_TAX] = BPF_S_MISC_TAX, | |
522 | [BPF_MISC|BPF_TXA] = BPF_S_MISC_TXA, | |
523 | [BPF_RET|BPF_K] = BPF_S_RET_K, | |
524 | [BPF_RET|BPF_A] = BPF_S_RET_A, | |
525 | [BPF_ALU|BPF_DIV|BPF_K] = BPF_S_ALU_DIV_K, | |
526 | [BPF_LD|BPF_MEM] = BPF_S_LD_MEM, | |
527 | [BPF_LDX|BPF_MEM] = BPF_S_LDX_MEM, | |
528 | [BPF_ST] = BPF_S_ST, | |
529 | [BPF_STX] = BPF_S_STX, | |
530 | [BPF_JMP|BPF_JA] = BPF_S_JMP_JA, | |
531 | [BPF_JMP|BPF_JEQ|BPF_K] = BPF_S_JMP_JEQ_K, | |
532 | [BPF_JMP|BPF_JEQ|BPF_X] = BPF_S_JMP_JEQ_X, | |
533 | [BPF_JMP|BPF_JGE|BPF_K] = BPF_S_JMP_JGE_K, | |
534 | [BPF_JMP|BPF_JGE|BPF_X] = BPF_S_JMP_JGE_X, | |
535 | [BPF_JMP|BPF_JGT|BPF_K] = BPF_S_JMP_JGT_K, | |
536 | [BPF_JMP|BPF_JGT|BPF_X] = BPF_S_JMP_JGT_X, | |
537 | [BPF_JMP|BPF_JSET|BPF_K] = BPF_S_JMP_JSET_K, | |
538 | [BPF_JMP|BPF_JSET|BPF_X] = BPF_S_JMP_JSET_X, | |
cba328fc | 539 | }; |
1da177e4 | 540 | int pc; |
aa1113d9 | 541 | bool anc_found; |
1da177e4 | 542 | |
1b93ae64 | 543 | if (flen == 0 || flen > BPF_MAXINSNS) |
1da177e4 LT |
544 | return -EINVAL; |
545 | ||
546 | /* check the filter code now */ | |
547 | for (pc = 0; pc < flen; pc++) { | |
cba328fc TH |
548 | struct sock_filter *ftest = &filter[pc]; |
549 | u16 code = ftest->code; | |
93699863 | 550 | |
cba328fc TH |
551 | if (code >= ARRAY_SIZE(codes)) |
552 | return -EINVAL; | |
553 | code = codes[code]; | |
8c1592d6 | 554 | if (!code) |
cba328fc | 555 | return -EINVAL; |
93699863 | 556 | /* Some instructions need special checks */ |
cba328fc TH |
557 | switch (code) { |
558 | case BPF_S_ALU_DIV_K: | |
b6069a95 ED |
559 | case BPF_S_ALU_MOD_K: |
560 | /* check for division by zero */ | |
561 | if (ftest->k == 0) | |
562 | return -EINVAL; | |
563 | break; | |
cba328fc TH |
564 | case BPF_S_LD_MEM: |
565 | case BPF_S_LDX_MEM: | |
566 | case BPF_S_ST: | |
567 | case BPF_S_STX: | |
568 | /* check for invalid memory addresses */ | |
93699863 KK |
569 | if (ftest->k >= BPF_MEMWORDS) |
570 | return -EINVAL; | |
571 | break; | |
cba328fc | 572 | case BPF_S_JMP_JA: |
93699863 KK |
573 | /* |
574 | * Note, the large ftest->k might cause loops. | |
575 | * Compare this with conditional jumps below, | |
576 | * where offsets are limited. --ANK (981016) | |
577 | */ | |
95c96174 | 578 | if (ftest->k >= (unsigned int)(flen-pc-1)) |
93699863 | 579 | return -EINVAL; |
01f2f3f6 | 580 | break; |
01f2f3f6 HPP |
581 | case BPF_S_JMP_JEQ_K: |
582 | case BPF_S_JMP_JEQ_X: | |
583 | case BPF_S_JMP_JGE_K: | |
584 | case BPF_S_JMP_JGE_X: | |
585 | case BPF_S_JMP_JGT_K: | |
586 | case BPF_S_JMP_JGT_X: | |
587 | case BPF_S_JMP_JSET_X: | |
588 | case BPF_S_JMP_JSET_K: | |
cba328fc | 589 | /* for conditionals both must be safe */ |
e35bedf3 | 590 | if (pc + ftest->jt + 1 >= flen || |
93699863 KK |
591 | pc + ftest->jf + 1 >= flen) |
592 | return -EINVAL; | |
cba328fc | 593 | break; |
12b16dad ED |
594 | case BPF_S_LD_W_ABS: |
595 | case BPF_S_LD_H_ABS: | |
596 | case BPF_S_LD_B_ABS: | |
aa1113d9 | 597 | anc_found = false; |
12b16dad ED |
598 | #define ANCILLARY(CODE) case SKF_AD_OFF + SKF_AD_##CODE: \ |
599 | code = BPF_S_ANC_##CODE; \ | |
aa1113d9 | 600 | anc_found = true; \ |
12b16dad ED |
601 | break |
602 | switch (ftest->k) { | |
603 | ANCILLARY(PROTOCOL); | |
604 | ANCILLARY(PKTTYPE); | |
605 | ANCILLARY(IFINDEX); | |
606 | ANCILLARY(NLATTR); | |
607 | ANCILLARY(NLATTR_NEST); | |
608 | ANCILLARY(MARK); | |
609 | ANCILLARY(QUEUE); | |
610 | ANCILLARY(HATYPE); | |
611 | ANCILLARY(RXHASH); | |
612 | ANCILLARY(CPU); | |
ffe06c17 | 613 | ANCILLARY(ALU_XOR_X); |
f3335031 ED |
614 | ANCILLARY(VLAN_TAG); |
615 | ANCILLARY(VLAN_TAG_PRESENT); | |
3e5289d5 | 616 | ANCILLARY(PAY_OFFSET); |
12b16dad | 617 | } |
aa1113d9 DB |
618 | |
619 | /* ancillary operation unknown or unsupported */ | |
620 | if (anc_found == false && ftest->k >= SKF_AD_OFF) | |
621 | return -EINVAL; | |
01f2f3f6 | 622 | } |
cba328fc | 623 | ftest->code = code; |
01f2f3f6 | 624 | } |
93699863 | 625 | |
01f2f3f6 HPP |
626 | /* last instruction must be a RET code */ |
627 | switch (filter[flen - 1].code) { | |
628 | case BPF_S_RET_K: | |
629 | case BPF_S_RET_A: | |
2d5311e4 | 630 | return check_load_and_stores(filter, flen); |
cba328fc TH |
631 | } |
632 | return -EINVAL; | |
1da177e4 | 633 | } |
b715631f | 634 | EXPORT_SYMBOL(sk_chk_filter); |
1da177e4 | 635 | |
47e958ea | 636 | /** |
46bcf14f | 637 | * sk_filter_release_rcu - Release a socket filter by rcu_head |
47e958ea PE |
638 | * @rcu: rcu_head that contains the sk_filter to free |
639 | */ | |
46bcf14f | 640 | void sk_filter_release_rcu(struct rcu_head *rcu) |
47e958ea PE |
641 | { |
642 | struct sk_filter *fp = container_of(rcu, struct sk_filter, rcu); | |
643 | ||
0a14842f | 644 | bpf_jit_free(fp); |
46bcf14f | 645 | kfree(fp); |
47e958ea | 646 | } |
46bcf14f | 647 | EXPORT_SYMBOL(sk_filter_release_rcu); |
47e958ea | 648 | |
302d6637 JP |
649 | static int __sk_prepare_filter(struct sk_filter *fp) |
650 | { | |
651 | int err; | |
652 | ||
653 | fp->bpf_func = sk_run_filter; | |
654 | ||
655 | err = sk_chk_filter(fp->insns, fp->len); | |
656 | if (err) | |
657 | return err; | |
658 | ||
659 | bpf_jit_compile(fp); | |
660 | return 0; | |
661 | } | |
662 | ||
663 | /** | |
664 | * sk_unattached_filter_create - create an unattached filter | |
665 | * @fprog: the filter program | |
c6c4b97c | 666 | * @pfp: the unattached filter that is created |
302d6637 | 667 | * |
c6c4b97c | 668 | * Create a filter independent of any socket. We first run some |
302d6637 JP |
669 | * sanity checks on it to make sure it does not explode on us later. |
670 | * If an error occurs or there is insufficient memory for the filter | |
671 | * a negative errno code is returned. On success the return is zero. | |
672 | */ | |
673 | int sk_unattached_filter_create(struct sk_filter **pfp, | |
674 | struct sock_fprog *fprog) | |
675 | { | |
676 | struct sk_filter *fp; | |
677 | unsigned int fsize = sizeof(struct sock_filter) * fprog->len; | |
678 | int err; | |
679 | ||
680 | /* Make sure new filter is there and in the right amounts. */ | |
681 | if (fprog->filter == NULL) | |
682 | return -EINVAL; | |
683 | ||
684 | fp = kmalloc(fsize + sizeof(*fp), GFP_KERNEL); | |
685 | if (!fp) | |
686 | return -ENOMEM; | |
687 | memcpy(fp->insns, fprog->filter, fsize); | |
688 | ||
689 | atomic_set(&fp->refcnt, 1); | |
690 | fp->len = fprog->len; | |
691 | ||
692 | err = __sk_prepare_filter(fp); | |
693 | if (err) | |
694 | goto free_mem; | |
695 | ||
696 | *pfp = fp; | |
697 | return 0; | |
698 | free_mem: | |
699 | kfree(fp); | |
700 | return err; | |
701 | } | |
702 | EXPORT_SYMBOL_GPL(sk_unattached_filter_create); | |
703 | ||
704 | void sk_unattached_filter_destroy(struct sk_filter *fp) | |
705 | { | |
706 | sk_filter_release(fp); | |
707 | } | |
708 | EXPORT_SYMBOL_GPL(sk_unattached_filter_destroy); | |
709 | ||
1da177e4 LT |
710 | /** |
711 | * sk_attach_filter - attach a socket filter | |
712 | * @fprog: the filter program | |
713 | * @sk: the socket to use | |
714 | * | |
715 | * Attach the user's filter code. We first run some sanity checks on | |
716 | * it to make sure it does not explode on us later. If an error | |
717 | * occurs or there is insufficient memory for the filter a negative | |
718 | * errno code is returned. On success the return is zero. | |
719 | */ | |
720 | int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk) | |
721 | { | |
d3904b73 | 722 | struct sk_filter *fp, *old_fp; |
1da177e4 LT |
723 | unsigned int fsize = sizeof(struct sock_filter) * fprog->len; |
724 | int err; | |
725 | ||
d59577b6 VB |
726 | if (sock_flag(sk, SOCK_FILTER_LOCKED)) |
727 | return -EPERM; | |
728 | ||
1da177e4 | 729 | /* Make sure new filter is there and in the right amounts. */ |
e35bedf3 KK |
730 | if (fprog->filter == NULL) |
731 | return -EINVAL; | |
1da177e4 LT |
732 | |
733 | fp = sock_kmalloc(sk, fsize+sizeof(*fp), GFP_KERNEL); | |
734 | if (!fp) | |
735 | return -ENOMEM; | |
736 | if (copy_from_user(fp->insns, fprog->filter, fsize)) { | |
4ec93edb | 737 | sock_kfree_s(sk, fp, fsize+sizeof(*fp)); |
1da177e4 LT |
738 | return -EFAULT; |
739 | } | |
740 | ||
741 | atomic_set(&fp->refcnt, 1); | |
742 | fp->len = fprog->len; | |
743 | ||
302d6637 | 744 | err = __sk_prepare_filter(fp); |
d3904b73 PE |
745 | if (err) { |
746 | sk_filter_uncharge(sk, fp); | |
747 | return err; | |
1da177e4 LT |
748 | } |
749 | ||
f91ff5b9 ED |
750 | old_fp = rcu_dereference_protected(sk->sk_filter, |
751 | sock_owned_by_user(sk)); | |
d3904b73 | 752 | rcu_assign_pointer(sk->sk_filter, fp); |
d3904b73 | 753 | |
9b013e05 | 754 | if (old_fp) |
46bcf14f | 755 | sk_filter_uncharge(sk, old_fp); |
d3904b73 | 756 | return 0; |
1da177e4 | 757 | } |
5ff3f073 | 758 | EXPORT_SYMBOL_GPL(sk_attach_filter); |
1da177e4 | 759 | |
55b33325 PE |
760 | int sk_detach_filter(struct sock *sk) |
761 | { | |
762 | int ret = -ENOENT; | |
763 | struct sk_filter *filter; | |
764 | ||
d59577b6 VB |
765 | if (sock_flag(sk, SOCK_FILTER_LOCKED)) |
766 | return -EPERM; | |
767 | ||
f91ff5b9 ED |
768 | filter = rcu_dereference_protected(sk->sk_filter, |
769 | sock_owned_by_user(sk)); | |
55b33325 | 770 | if (filter) { |
a9b3cd7f | 771 | RCU_INIT_POINTER(sk->sk_filter, NULL); |
46bcf14f | 772 | sk_filter_uncharge(sk, filter); |
55b33325 PE |
773 | ret = 0; |
774 | } | |
55b33325 PE |
775 | return ret; |
776 | } | |
5ff3f073 | 777 | EXPORT_SYMBOL_GPL(sk_detach_filter); |
a8fc9277 | 778 | |
ed13998c | 779 | void sk_decode_filter(struct sock_filter *filt, struct sock_filter *to) |
a8fc9277 PE |
780 | { |
781 | static const u16 decodes[] = { | |
782 | [BPF_S_ALU_ADD_K] = BPF_ALU|BPF_ADD|BPF_K, | |
783 | [BPF_S_ALU_ADD_X] = BPF_ALU|BPF_ADD|BPF_X, | |
784 | [BPF_S_ALU_SUB_K] = BPF_ALU|BPF_SUB|BPF_K, | |
785 | [BPF_S_ALU_SUB_X] = BPF_ALU|BPF_SUB|BPF_X, | |
786 | [BPF_S_ALU_MUL_K] = BPF_ALU|BPF_MUL|BPF_K, | |
787 | [BPF_S_ALU_MUL_X] = BPF_ALU|BPF_MUL|BPF_X, | |
788 | [BPF_S_ALU_DIV_X] = BPF_ALU|BPF_DIV|BPF_X, | |
789 | [BPF_S_ALU_MOD_K] = BPF_ALU|BPF_MOD|BPF_K, | |
790 | [BPF_S_ALU_MOD_X] = BPF_ALU|BPF_MOD|BPF_X, | |
791 | [BPF_S_ALU_AND_K] = BPF_ALU|BPF_AND|BPF_K, | |
792 | [BPF_S_ALU_AND_X] = BPF_ALU|BPF_AND|BPF_X, | |
793 | [BPF_S_ALU_OR_K] = BPF_ALU|BPF_OR|BPF_K, | |
794 | [BPF_S_ALU_OR_X] = BPF_ALU|BPF_OR|BPF_X, | |
795 | [BPF_S_ALU_XOR_K] = BPF_ALU|BPF_XOR|BPF_K, | |
796 | [BPF_S_ALU_XOR_X] = BPF_ALU|BPF_XOR|BPF_X, | |
797 | [BPF_S_ALU_LSH_K] = BPF_ALU|BPF_LSH|BPF_K, | |
798 | [BPF_S_ALU_LSH_X] = BPF_ALU|BPF_LSH|BPF_X, | |
799 | [BPF_S_ALU_RSH_K] = BPF_ALU|BPF_RSH|BPF_K, | |
800 | [BPF_S_ALU_RSH_X] = BPF_ALU|BPF_RSH|BPF_X, | |
801 | [BPF_S_ALU_NEG] = BPF_ALU|BPF_NEG, | |
802 | [BPF_S_LD_W_ABS] = BPF_LD|BPF_W|BPF_ABS, | |
803 | [BPF_S_LD_H_ABS] = BPF_LD|BPF_H|BPF_ABS, | |
804 | [BPF_S_LD_B_ABS] = BPF_LD|BPF_B|BPF_ABS, | |
805 | [BPF_S_ANC_PROTOCOL] = BPF_LD|BPF_B|BPF_ABS, | |
806 | [BPF_S_ANC_PKTTYPE] = BPF_LD|BPF_B|BPF_ABS, | |
807 | [BPF_S_ANC_IFINDEX] = BPF_LD|BPF_B|BPF_ABS, | |
808 | [BPF_S_ANC_NLATTR] = BPF_LD|BPF_B|BPF_ABS, | |
809 | [BPF_S_ANC_NLATTR_NEST] = BPF_LD|BPF_B|BPF_ABS, | |
810 | [BPF_S_ANC_MARK] = BPF_LD|BPF_B|BPF_ABS, | |
811 | [BPF_S_ANC_QUEUE] = BPF_LD|BPF_B|BPF_ABS, | |
812 | [BPF_S_ANC_HATYPE] = BPF_LD|BPF_B|BPF_ABS, | |
813 | [BPF_S_ANC_RXHASH] = BPF_LD|BPF_B|BPF_ABS, | |
814 | [BPF_S_ANC_CPU] = BPF_LD|BPF_B|BPF_ABS, | |
815 | [BPF_S_ANC_ALU_XOR_X] = BPF_LD|BPF_B|BPF_ABS, | |
816 | [BPF_S_ANC_SECCOMP_LD_W] = BPF_LD|BPF_B|BPF_ABS, | |
817 | [BPF_S_ANC_VLAN_TAG] = BPF_LD|BPF_B|BPF_ABS, | |
818 | [BPF_S_ANC_VLAN_TAG_PRESENT] = BPF_LD|BPF_B|BPF_ABS, | |
3e5289d5 | 819 | [BPF_S_ANC_PAY_OFFSET] = BPF_LD|BPF_B|BPF_ABS, |
a8fc9277 PE |
820 | [BPF_S_LD_W_LEN] = BPF_LD|BPF_W|BPF_LEN, |
821 | [BPF_S_LD_W_IND] = BPF_LD|BPF_W|BPF_IND, | |
822 | [BPF_S_LD_H_IND] = BPF_LD|BPF_H|BPF_IND, | |
823 | [BPF_S_LD_B_IND] = BPF_LD|BPF_B|BPF_IND, | |
824 | [BPF_S_LD_IMM] = BPF_LD|BPF_IMM, | |
825 | [BPF_S_LDX_W_LEN] = BPF_LDX|BPF_W|BPF_LEN, | |
826 | [BPF_S_LDX_B_MSH] = BPF_LDX|BPF_B|BPF_MSH, | |
827 | [BPF_S_LDX_IMM] = BPF_LDX|BPF_IMM, | |
828 | [BPF_S_MISC_TAX] = BPF_MISC|BPF_TAX, | |
829 | [BPF_S_MISC_TXA] = BPF_MISC|BPF_TXA, | |
830 | [BPF_S_RET_K] = BPF_RET|BPF_K, | |
831 | [BPF_S_RET_A] = BPF_RET|BPF_A, | |
832 | [BPF_S_ALU_DIV_K] = BPF_ALU|BPF_DIV|BPF_K, | |
833 | [BPF_S_LD_MEM] = BPF_LD|BPF_MEM, | |
834 | [BPF_S_LDX_MEM] = BPF_LDX|BPF_MEM, | |
835 | [BPF_S_ST] = BPF_ST, | |
836 | [BPF_S_STX] = BPF_STX, | |
837 | [BPF_S_JMP_JA] = BPF_JMP|BPF_JA, | |
838 | [BPF_S_JMP_JEQ_K] = BPF_JMP|BPF_JEQ|BPF_K, | |
839 | [BPF_S_JMP_JEQ_X] = BPF_JMP|BPF_JEQ|BPF_X, | |
840 | [BPF_S_JMP_JGE_K] = BPF_JMP|BPF_JGE|BPF_K, | |
841 | [BPF_S_JMP_JGE_X] = BPF_JMP|BPF_JGE|BPF_X, | |
842 | [BPF_S_JMP_JGT_K] = BPF_JMP|BPF_JGT|BPF_K, | |
843 | [BPF_S_JMP_JGT_X] = BPF_JMP|BPF_JGT|BPF_X, | |
844 | [BPF_S_JMP_JSET_K] = BPF_JMP|BPF_JSET|BPF_K, | |
845 | [BPF_S_JMP_JSET_X] = BPF_JMP|BPF_JSET|BPF_X, | |
846 | }; | |
847 | u16 code; | |
848 | ||
849 | code = filt->code; | |
850 | ||
851 | to->code = decodes[code]; | |
852 | to->jt = filt->jt; | |
853 | to->jf = filt->jf; | |
cd7361dc | 854 | to->k = filt->k; |
a8fc9277 PE |
855 | } |
856 | ||
857 | int sk_get_filter(struct sock *sk, struct sock_filter __user *ubuf, unsigned int len) | |
858 | { | |
859 | struct sk_filter *filter; | |
860 | int i, ret; | |
861 | ||
862 | lock_sock(sk); | |
863 | filter = rcu_dereference_protected(sk->sk_filter, | |
864 | sock_owned_by_user(sk)); | |
865 | ret = 0; | |
866 | if (!filter) | |
867 | goto out; | |
868 | ret = filter->len; | |
869 | if (!len) | |
870 | goto out; | |
871 | ret = -EINVAL; | |
872 | if (len < filter->len) | |
873 | goto out; | |
874 | ||
875 | ret = -EFAULT; | |
876 | for (i = 0; i < filter->len; i++) { | |
877 | struct sock_filter fb; | |
878 | ||
879 | sk_decode_filter(&filter->insns[i], &fb); | |
880 | if (copy_to_user(&ubuf[i], &fb, sizeof(fb))) | |
881 | goto out; | |
882 | } | |
883 | ||
884 | ret = filter->len; | |
885 | out: | |
886 | release_sock(sk); | |
887 | return ret; | |
888 | } |