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> |
c26aed40 | 39 | #include <linux/reciprocal_div.h> |
86e4ca66 | 40 | #include <linux/ratelimit.h> |
46b325c7 | 41 | #include <linux/seccomp.h> |
f3335031 | 42 | #include <linux/if_vlan.h> |
1da177e4 | 43 | |
f03fb3f4 JS |
44 | /* No hurry in this branch |
45 | * | |
46 | * Exported for the bpf jit load helper. | |
47 | */ | |
48 | void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb, int k, unsigned int size) | |
1da177e4 LT |
49 | { |
50 | u8 *ptr = NULL; | |
51 | ||
52 | if (k >= SKF_NET_OFF) | |
d56f90a7 | 53 | ptr = skb_network_header(skb) + k - SKF_NET_OFF; |
1da177e4 | 54 | else if (k >= SKF_LL_OFF) |
98e399f8 | 55 | ptr = skb_mac_header(skb) + k - SKF_LL_OFF; |
1da177e4 | 56 | |
4bc65dd8 | 57 | if (ptr >= skb->head && ptr + size <= skb_tail_pointer(skb)) |
1da177e4 LT |
58 | return ptr; |
59 | return NULL; | |
60 | } | |
61 | ||
62ab0812 | 62 | static inline void *load_pointer(const struct sk_buff *skb, int k, |
4ec93edb | 63 | unsigned int size, void *buffer) |
0b05b2a4 PM |
64 | { |
65 | if (k >= 0) | |
66 | return skb_header_pointer(skb, k, size, buffer); | |
f03fb3f4 | 67 | return bpf_internal_load_pointer_neg_helper(skb, k, size); |
0b05b2a4 PM |
68 | } |
69 | ||
43db6d65 SH |
70 | /** |
71 | * sk_filter - run a packet through a socket filter | |
72 | * @sk: sock associated with &sk_buff | |
73 | * @skb: buffer to filter | |
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 | */ | |
82 | int sk_filter(struct sock *sk, struct sk_buff *skb) | |
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); |
0d7da9dd | 103 | |
43db6d65 SH |
104 | err = pkt_len ? pskb_trim(skb, pkt_len) : -EPERM; |
105 | } | |
80f8f102 | 106 | rcu_read_unlock(); |
43db6d65 SH |
107 | |
108 | return err; | |
109 | } | |
110 | EXPORT_SYMBOL(sk_filter); | |
111 | ||
1da177e4 | 112 | /** |
2966b66c | 113 | * sk_run_filter - run a filter on a socket |
1da177e4 | 114 | * @skb: buffer to run the filter on |
697d0e33 | 115 | * @fentry: filter to apply |
1da177e4 LT |
116 | * |
117 | * Decode and apply filter instructions to the skb->data. | |
93aaae2e ED |
118 | * Return length to keep, 0 for none. @skb is the data we are |
119 | * filtering, @filter is the array of filter instructions. | |
120 | * Because all jumps are guaranteed to be before last instruction, | |
121 | * and last instruction guaranteed to be a RET, we dont need to check | |
122 | * flen. (We used to pass to this function the length of filter) | |
1da177e4 | 123 | */ |
62ab0812 ED |
124 | unsigned int sk_run_filter(const struct sk_buff *skb, |
125 | const struct sock_filter *fentry) | |
1da177e4 | 126 | { |
0b05b2a4 | 127 | void *ptr; |
2966b66c KK |
128 | u32 A = 0; /* Accumulator */ |
129 | u32 X = 0; /* Index Register */ | |
1da177e4 | 130 | u32 mem[BPF_MEMWORDS]; /* Scratch Memory Store */ |
0b05b2a4 | 131 | u32 tmp; |
1da177e4 | 132 | int k; |
1da177e4 LT |
133 | |
134 | /* | |
135 | * Process array of filter instructions. | |
136 | */ | |
93aaae2e ED |
137 | for (;; fentry++) { |
138 | #if defined(CONFIG_X86_32) | |
139 | #define K (fentry->k) | |
140 | #else | |
141 | const u32 K = fentry->k; | |
142 | #endif | |
4ec93edb | 143 | |
1da177e4 | 144 | switch (fentry->code) { |
01f2f3f6 | 145 | case BPF_S_ALU_ADD_X: |
1da177e4 LT |
146 | A += X; |
147 | continue; | |
01f2f3f6 | 148 | case BPF_S_ALU_ADD_K: |
93aaae2e | 149 | A += K; |
1da177e4 | 150 | continue; |
01f2f3f6 | 151 | case BPF_S_ALU_SUB_X: |
1da177e4 LT |
152 | A -= X; |
153 | continue; | |
01f2f3f6 | 154 | case BPF_S_ALU_SUB_K: |
93aaae2e | 155 | A -= K; |
1da177e4 | 156 | continue; |
01f2f3f6 | 157 | case BPF_S_ALU_MUL_X: |
1da177e4 LT |
158 | A *= X; |
159 | continue; | |
01f2f3f6 | 160 | case BPF_S_ALU_MUL_K: |
93aaae2e | 161 | A *= K; |
1da177e4 | 162 | continue; |
01f2f3f6 | 163 | case BPF_S_ALU_DIV_X: |
1da177e4 LT |
164 | if (X == 0) |
165 | return 0; | |
166 | A /= X; | |
167 | continue; | |
01f2f3f6 | 168 | case BPF_S_ALU_DIV_K: |
c26aed40 | 169 | A = reciprocal_divide(A, K); |
1da177e4 | 170 | continue; |
b6069a95 ED |
171 | case BPF_S_ALU_MOD_X: |
172 | if (X == 0) | |
173 | return 0; | |
174 | A %= X; | |
175 | continue; | |
176 | case BPF_S_ALU_MOD_K: | |
177 | A %= K; | |
178 | continue; | |
01f2f3f6 | 179 | case BPF_S_ALU_AND_X: |
1da177e4 LT |
180 | A &= X; |
181 | continue; | |
01f2f3f6 | 182 | case BPF_S_ALU_AND_K: |
93aaae2e | 183 | A &= K; |
1da177e4 | 184 | continue; |
01f2f3f6 | 185 | case BPF_S_ALU_OR_X: |
1da177e4 LT |
186 | A |= X; |
187 | continue; | |
01f2f3f6 | 188 | case BPF_S_ALU_OR_K: |
93aaae2e | 189 | A |= K; |
1da177e4 | 190 | continue; |
9e49e889 DB |
191 | case BPF_S_ANC_ALU_XOR_X: |
192 | case BPF_S_ALU_XOR_X: | |
193 | A ^= X; | |
194 | continue; | |
195 | case BPF_S_ALU_XOR_K: | |
196 | A ^= K; | |
197 | continue; | |
01f2f3f6 | 198 | case BPF_S_ALU_LSH_X: |
1da177e4 LT |
199 | A <<= X; |
200 | continue; | |
01f2f3f6 | 201 | case BPF_S_ALU_LSH_K: |
93aaae2e | 202 | A <<= K; |
1da177e4 | 203 | continue; |
01f2f3f6 | 204 | case BPF_S_ALU_RSH_X: |
1da177e4 LT |
205 | A >>= X; |
206 | continue; | |
01f2f3f6 | 207 | case BPF_S_ALU_RSH_K: |
93aaae2e | 208 | A >>= K; |
1da177e4 | 209 | continue; |
01f2f3f6 | 210 | case BPF_S_ALU_NEG: |
1da177e4 LT |
211 | A = -A; |
212 | continue; | |
01f2f3f6 | 213 | case BPF_S_JMP_JA: |
93aaae2e | 214 | fentry += K; |
1da177e4 | 215 | continue; |
01f2f3f6 | 216 | case BPF_S_JMP_JGT_K: |
93aaae2e | 217 | fentry += (A > K) ? fentry->jt : fentry->jf; |
1da177e4 | 218 | continue; |
01f2f3f6 | 219 | case BPF_S_JMP_JGE_K: |
93aaae2e | 220 | fentry += (A >= K) ? fentry->jt : fentry->jf; |
1da177e4 | 221 | continue; |
01f2f3f6 | 222 | case BPF_S_JMP_JEQ_K: |
93aaae2e | 223 | fentry += (A == K) ? fentry->jt : fentry->jf; |
1da177e4 | 224 | continue; |
01f2f3f6 | 225 | case BPF_S_JMP_JSET_K: |
93aaae2e | 226 | fentry += (A & K) ? fentry->jt : fentry->jf; |
1da177e4 | 227 | continue; |
01f2f3f6 | 228 | case BPF_S_JMP_JGT_X: |
93aaae2e | 229 | fentry += (A > X) ? fentry->jt : fentry->jf; |
1da177e4 | 230 | continue; |
01f2f3f6 | 231 | case BPF_S_JMP_JGE_X: |
93aaae2e | 232 | fentry += (A >= X) ? fentry->jt : fentry->jf; |
1da177e4 | 233 | continue; |
01f2f3f6 | 234 | case BPF_S_JMP_JEQ_X: |
93aaae2e | 235 | fentry += (A == X) ? fentry->jt : fentry->jf; |
1da177e4 | 236 | continue; |
01f2f3f6 | 237 | case BPF_S_JMP_JSET_X: |
93aaae2e | 238 | fentry += (A & X) ? fentry->jt : fentry->jf; |
1da177e4 | 239 | continue; |
01f2f3f6 | 240 | case BPF_S_LD_W_ABS: |
93aaae2e | 241 | k = K; |
e35bedf3 | 242 | load_w: |
0b05b2a4 PM |
243 | ptr = load_pointer(skb, k, 4, &tmp); |
244 | if (ptr != NULL) { | |
d3e2ce3b | 245 | A = get_unaligned_be32(ptr); |
0b05b2a4 | 246 | continue; |
1da177e4 | 247 | } |
12b16dad | 248 | return 0; |
01f2f3f6 | 249 | case BPF_S_LD_H_ABS: |
93aaae2e | 250 | k = K; |
e35bedf3 | 251 | load_h: |
0b05b2a4 PM |
252 | ptr = load_pointer(skb, k, 2, &tmp); |
253 | if (ptr != NULL) { | |
d3e2ce3b | 254 | A = get_unaligned_be16(ptr); |
0b05b2a4 | 255 | continue; |
1da177e4 | 256 | } |
12b16dad | 257 | return 0; |
01f2f3f6 | 258 | case BPF_S_LD_B_ABS: |
93aaae2e | 259 | k = K; |
1da177e4 | 260 | load_b: |
0b05b2a4 PM |
261 | ptr = load_pointer(skb, k, 1, &tmp); |
262 | if (ptr != NULL) { | |
263 | A = *(u8 *)ptr; | |
264 | continue; | |
1da177e4 | 265 | } |
12b16dad | 266 | return 0; |
01f2f3f6 | 267 | case BPF_S_LD_W_LEN: |
3154e540 | 268 | A = skb->len; |
1da177e4 | 269 | continue; |
01f2f3f6 | 270 | case BPF_S_LDX_W_LEN: |
3154e540 | 271 | X = skb->len; |
1da177e4 | 272 | continue; |
01f2f3f6 | 273 | case BPF_S_LD_W_IND: |
93aaae2e | 274 | k = X + K; |
1da177e4 | 275 | goto load_w; |
01f2f3f6 | 276 | case BPF_S_LD_H_IND: |
93aaae2e | 277 | k = X + K; |
1da177e4 | 278 | goto load_h; |
01f2f3f6 | 279 | case BPF_S_LD_B_IND: |
93aaae2e | 280 | k = X + K; |
1da177e4 | 281 | goto load_b; |
01f2f3f6 | 282 | case BPF_S_LDX_B_MSH: |
93aaae2e | 283 | ptr = load_pointer(skb, K, 1, &tmp); |
0b05b2a4 PM |
284 | if (ptr != NULL) { |
285 | X = (*(u8 *)ptr & 0xf) << 2; | |
286 | continue; | |
287 | } | |
288 | return 0; | |
01f2f3f6 | 289 | case BPF_S_LD_IMM: |
93aaae2e | 290 | A = K; |
1da177e4 | 291 | continue; |
01f2f3f6 | 292 | case BPF_S_LDX_IMM: |
93aaae2e | 293 | X = K; |
1da177e4 | 294 | continue; |
01f2f3f6 | 295 | case BPF_S_LD_MEM: |
2d5311e4 | 296 | A = mem[K]; |
1da177e4 | 297 | continue; |
01f2f3f6 | 298 | case BPF_S_LDX_MEM: |
2d5311e4 | 299 | X = mem[K]; |
1da177e4 | 300 | continue; |
01f2f3f6 | 301 | case BPF_S_MISC_TAX: |
1da177e4 LT |
302 | X = A; |
303 | continue; | |
01f2f3f6 | 304 | case BPF_S_MISC_TXA: |
1da177e4 LT |
305 | A = X; |
306 | continue; | |
01f2f3f6 | 307 | case BPF_S_RET_K: |
93aaae2e | 308 | return K; |
01f2f3f6 | 309 | case BPF_S_RET_A: |
4bad4dc9 | 310 | return A; |
01f2f3f6 | 311 | case BPF_S_ST: |
93aaae2e | 312 | mem[K] = A; |
1da177e4 | 313 | continue; |
01f2f3f6 | 314 | case BPF_S_STX: |
93aaae2e | 315 | mem[K] = X; |
1da177e4 | 316 | continue; |
12b16dad | 317 | case BPF_S_ANC_PROTOCOL: |
252e3346 | 318 | A = ntohs(skb->protocol); |
1da177e4 | 319 | continue; |
12b16dad | 320 | case BPF_S_ANC_PKTTYPE: |
1da177e4 LT |
321 | A = skb->pkt_type; |
322 | continue; | |
12b16dad | 323 | case BPF_S_ANC_IFINDEX: |
40eaf962 PLE |
324 | if (!skb->dev) |
325 | return 0; | |
1da177e4 LT |
326 | A = skb->dev->ifindex; |
327 | continue; | |
12b16dad | 328 | case BPF_S_ANC_MARK: |
7e75f93e | 329 | A = skb->mark; |
330 | continue; | |
12b16dad | 331 | case BPF_S_ANC_QUEUE: |
d19742fb ED |
332 | A = skb->queue_mapping; |
333 | continue; | |
12b16dad | 334 | case BPF_S_ANC_HATYPE: |
40eaf962 PLE |
335 | if (!skb->dev) |
336 | return 0; | |
337 | A = skb->dev->type; | |
338 | continue; | |
12b16dad | 339 | case BPF_S_ANC_RXHASH: |
da2033c2 ED |
340 | A = skb->rxhash; |
341 | continue; | |
12b16dad | 342 | case BPF_S_ANC_CPU: |
da2033c2 ED |
343 | A = raw_smp_processor_id(); |
344 | continue; | |
f3335031 ED |
345 | case BPF_S_ANC_VLAN_TAG: |
346 | A = vlan_tx_tag_get(skb); | |
347 | continue; | |
348 | case BPF_S_ANC_VLAN_TAG_PRESENT: | |
349 | A = !!vlan_tx_tag_present(skb); | |
350 | continue; | |
12b16dad | 351 | case BPF_S_ANC_NLATTR: { |
4738c1db PM |
352 | struct nlattr *nla; |
353 | ||
354 | if (skb_is_nonlinear(skb)) | |
355 | return 0; | |
356 | if (A > skb->len - sizeof(struct nlattr)) | |
357 | return 0; | |
358 | ||
359 | nla = nla_find((struct nlattr *)&skb->data[A], | |
360 | skb->len - A, X); | |
361 | if (nla) | |
362 | A = (void *)nla - (void *)skb->data; | |
363 | else | |
364 | A = 0; | |
365 | continue; | |
366 | } | |
12b16dad | 367 | case BPF_S_ANC_NLATTR_NEST: { |
d214c753 PNA |
368 | struct nlattr *nla; |
369 | ||
370 | if (skb_is_nonlinear(skb)) | |
371 | return 0; | |
372 | if (A > skb->len - sizeof(struct nlattr)) | |
373 | return 0; | |
374 | ||
375 | nla = (struct nlattr *)&skb->data[A]; | |
376 | if (nla->nla_len > A - skb->len) | |
377 | return 0; | |
378 | ||
379 | nla = nla_find_nested(nla, X); | |
380 | if (nla) | |
381 | A = (void *)nla - (void *)skb->data; | |
382 | else | |
383 | A = 0; | |
384 | continue; | |
385 | } | |
46b325c7 WD |
386 | #ifdef CONFIG_SECCOMP_FILTER |
387 | case BPF_S_ANC_SECCOMP_LD_W: | |
388 | A = seccomp_bpf_load(fentry->k); | |
389 | continue; | |
390 | #endif | |
1da177e4 | 391 | default: |
6c4a5cb2 JP |
392 | WARN_RATELIMIT(1, "Unknown code:%u jt:%u tf:%u k:%u\n", |
393 | fentry->code, fentry->jt, | |
394 | fentry->jf, fentry->k); | |
1da177e4 LT |
395 | return 0; |
396 | } | |
397 | } | |
398 | ||
399 | return 0; | |
400 | } | |
b715631f | 401 | EXPORT_SYMBOL(sk_run_filter); |
1da177e4 | 402 | |
2d5311e4 ED |
403 | /* |
404 | * Security : | |
405 | * A BPF program is able to use 16 cells of memory to store intermediate | |
406 | * values (check u32 mem[BPF_MEMWORDS] in sk_run_filter()) | |
407 | * As we dont want to clear mem[] array for each packet going through | |
408 | * sk_run_filter(), we check that filter loaded by user never try to read | |
409 | * a cell if not previously written, and we check all branches to be sure | |
25985edc | 410 | * a malicious user doesn't try to abuse us. |
2d5311e4 ED |
411 | */ |
412 | static int check_load_and_stores(struct sock_filter *filter, int flen) | |
413 | { | |
414 | u16 *masks, memvalid = 0; /* one bit per cell, 16 cells */ | |
415 | int pc, ret = 0; | |
416 | ||
417 | BUILD_BUG_ON(BPF_MEMWORDS > 16); | |
418 | masks = kmalloc(flen * sizeof(*masks), GFP_KERNEL); | |
419 | if (!masks) | |
420 | return -ENOMEM; | |
421 | memset(masks, 0xff, flen * sizeof(*masks)); | |
422 | ||
423 | for (pc = 0; pc < flen; pc++) { | |
424 | memvalid &= masks[pc]; | |
425 | ||
426 | switch (filter[pc].code) { | |
427 | case BPF_S_ST: | |
428 | case BPF_S_STX: | |
429 | memvalid |= (1 << filter[pc].k); | |
430 | break; | |
431 | case BPF_S_LD_MEM: | |
432 | case BPF_S_LDX_MEM: | |
433 | if (!(memvalid & (1 << filter[pc].k))) { | |
434 | ret = -EINVAL; | |
435 | goto error; | |
436 | } | |
437 | break; | |
438 | case BPF_S_JMP_JA: | |
439 | /* a jump must set masks on target */ | |
440 | masks[pc + 1 + filter[pc].k] &= memvalid; | |
441 | memvalid = ~0; | |
442 | break; | |
443 | case BPF_S_JMP_JEQ_K: | |
444 | case BPF_S_JMP_JEQ_X: | |
445 | case BPF_S_JMP_JGE_K: | |
446 | case BPF_S_JMP_JGE_X: | |
447 | case BPF_S_JMP_JGT_K: | |
448 | case BPF_S_JMP_JGT_X: | |
449 | case BPF_S_JMP_JSET_X: | |
450 | case BPF_S_JMP_JSET_K: | |
451 | /* a jump must set masks on targets */ | |
452 | masks[pc + 1 + filter[pc].jt] &= memvalid; | |
453 | masks[pc + 1 + filter[pc].jf] &= memvalid; | |
454 | memvalid = ~0; | |
455 | break; | |
456 | } | |
457 | } | |
458 | error: | |
459 | kfree(masks); | |
460 | return ret; | |
461 | } | |
462 | ||
1da177e4 LT |
463 | /** |
464 | * sk_chk_filter - verify socket filter code | |
465 | * @filter: filter to verify | |
466 | * @flen: length of filter | |
467 | * | |
468 | * Check the user's filter code. If we let some ugly | |
469 | * filter code slip through kaboom! The filter must contain | |
93699863 KK |
470 | * no references or jumps that are out of range, no illegal |
471 | * instructions, and must end with a RET instruction. | |
1da177e4 | 472 | * |
7b11f69f KK |
473 | * All jumps are forward as they are not signed. |
474 | * | |
475 | * Returns 0 if the rule set is legal or -EINVAL if not. | |
1da177e4 | 476 | */ |
4f25af27 | 477 | int sk_chk_filter(struct sock_filter *filter, unsigned int flen) |
1da177e4 | 478 | { |
cba328fc TH |
479 | /* |
480 | * Valid instructions are initialized to non-0. | |
481 | * Invalid instructions are initialized to 0. | |
482 | */ | |
483 | static const u8 codes[] = { | |
8c1592d6 ED |
484 | [BPF_ALU|BPF_ADD|BPF_K] = BPF_S_ALU_ADD_K, |
485 | [BPF_ALU|BPF_ADD|BPF_X] = BPF_S_ALU_ADD_X, | |
486 | [BPF_ALU|BPF_SUB|BPF_K] = BPF_S_ALU_SUB_K, | |
487 | [BPF_ALU|BPF_SUB|BPF_X] = BPF_S_ALU_SUB_X, | |
488 | [BPF_ALU|BPF_MUL|BPF_K] = BPF_S_ALU_MUL_K, | |
489 | [BPF_ALU|BPF_MUL|BPF_X] = BPF_S_ALU_MUL_X, | |
490 | [BPF_ALU|BPF_DIV|BPF_X] = BPF_S_ALU_DIV_X, | |
b6069a95 ED |
491 | [BPF_ALU|BPF_MOD|BPF_K] = BPF_S_ALU_MOD_K, |
492 | [BPF_ALU|BPF_MOD|BPF_X] = BPF_S_ALU_MOD_X, | |
8c1592d6 ED |
493 | [BPF_ALU|BPF_AND|BPF_K] = BPF_S_ALU_AND_K, |
494 | [BPF_ALU|BPF_AND|BPF_X] = BPF_S_ALU_AND_X, | |
495 | [BPF_ALU|BPF_OR|BPF_K] = BPF_S_ALU_OR_K, | |
496 | [BPF_ALU|BPF_OR|BPF_X] = BPF_S_ALU_OR_X, | |
9e49e889 DB |
497 | [BPF_ALU|BPF_XOR|BPF_K] = BPF_S_ALU_XOR_K, |
498 | [BPF_ALU|BPF_XOR|BPF_X] = BPF_S_ALU_XOR_X, | |
8c1592d6 ED |
499 | [BPF_ALU|BPF_LSH|BPF_K] = BPF_S_ALU_LSH_K, |
500 | [BPF_ALU|BPF_LSH|BPF_X] = BPF_S_ALU_LSH_X, | |
501 | [BPF_ALU|BPF_RSH|BPF_K] = BPF_S_ALU_RSH_K, | |
502 | [BPF_ALU|BPF_RSH|BPF_X] = BPF_S_ALU_RSH_X, | |
503 | [BPF_ALU|BPF_NEG] = BPF_S_ALU_NEG, | |
504 | [BPF_LD|BPF_W|BPF_ABS] = BPF_S_LD_W_ABS, | |
505 | [BPF_LD|BPF_H|BPF_ABS] = BPF_S_LD_H_ABS, | |
506 | [BPF_LD|BPF_B|BPF_ABS] = BPF_S_LD_B_ABS, | |
507 | [BPF_LD|BPF_W|BPF_LEN] = BPF_S_LD_W_LEN, | |
508 | [BPF_LD|BPF_W|BPF_IND] = BPF_S_LD_W_IND, | |
509 | [BPF_LD|BPF_H|BPF_IND] = BPF_S_LD_H_IND, | |
510 | [BPF_LD|BPF_B|BPF_IND] = BPF_S_LD_B_IND, | |
511 | [BPF_LD|BPF_IMM] = BPF_S_LD_IMM, | |
512 | [BPF_LDX|BPF_W|BPF_LEN] = BPF_S_LDX_W_LEN, | |
513 | [BPF_LDX|BPF_B|BPF_MSH] = BPF_S_LDX_B_MSH, | |
514 | [BPF_LDX|BPF_IMM] = BPF_S_LDX_IMM, | |
515 | [BPF_MISC|BPF_TAX] = BPF_S_MISC_TAX, | |
516 | [BPF_MISC|BPF_TXA] = BPF_S_MISC_TXA, | |
517 | [BPF_RET|BPF_K] = BPF_S_RET_K, | |
518 | [BPF_RET|BPF_A] = BPF_S_RET_A, | |
519 | [BPF_ALU|BPF_DIV|BPF_K] = BPF_S_ALU_DIV_K, | |
520 | [BPF_LD|BPF_MEM] = BPF_S_LD_MEM, | |
521 | [BPF_LDX|BPF_MEM] = BPF_S_LDX_MEM, | |
522 | [BPF_ST] = BPF_S_ST, | |
523 | [BPF_STX] = BPF_S_STX, | |
524 | [BPF_JMP|BPF_JA] = BPF_S_JMP_JA, | |
525 | [BPF_JMP|BPF_JEQ|BPF_K] = BPF_S_JMP_JEQ_K, | |
526 | [BPF_JMP|BPF_JEQ|BPF_X] = BPF_S_JMP_JEQ_X, | |
527 | [BPF_JMP|BPF_JGE|BPF_K] = BPF_S_JMP_JGE_K, | |
528 | [BPF_JMP|BPF_JGE|BPF_X] = BPF_S_JMP_JGE_X, | |
529 | [BPF_JMP|BPF_JGT|BPF_K] = BPF_S_JMP_JGT_K, | |
530 | [BPF_JMP|BPF_JGT|BPF_X] = BPF_S_JMP_JGT_X, | |
531 | [BPF_JMP|BPF_JSET|BPF_K] = BPF_S_JMP_JSET_K, | |
532 | [BPF_JMP|BPF_JSET|BPF_X] = BPF_S_JMP_JSET_X, | |
cba328fc | 533 | }; |
1da177e4 | 534 | int pc; |
aa1113d9 | 535 | bool anc_found; |
1da177e4 | 536 | |
1b93ae64 | 537 | if (flen == 0 || flen > BPF_MAXINSNS) |
1da177e4 LT |
538 | return -EINVAL; |
539 | ||
540 | /* check the filter code now */ | |
541 | for (pc = 0; pc < flen; pc++) { | |
cba328fc TH |
542 | struct sock_filter *ftest = &filter[pc]; |
543 | u16 code = ftest->code; | |
93699863 | 544 | |
cba328fc TH |
545 | if (code >= ARRAY_SIZE(codes)) |
546 | return -EINVAL; | |
547 | code = codes[code]; | |
8c1592d6 | 548 | if (!code) |
cba328fc | 549 | return -EINVAL; |
93699863 | 550 | /* Some instructions need special checks */ |
cba328fc TH |
551 | switch (code) { |
552 | case BPF_S_ALU_DIV_K: | |
93699863 KK |
553 | /* check for division by zero */ |
554 | if (ftest->k == 0) | |
1da177e4 | 555 | return -EINVAL; |
c26aed40 | 556 | ftest->k = reciprocal_value(ftest->k); |
93699863 | 557 | break; |
b6069a95 ED |
558 | case BPF_S_ALU_MOD_K: |
559 | /* check for division by zero */ | |
560 | if (ftest->k == 0) | |
561 | return -EINVAL; | |
562 | break; | |
cba328fc TH |
563 | case BPF_S_LD_MEM: |
564 | case BPF_S_LDX_MEM: | |
565 | case BPF_S_ST: | |
566 | case BPF_S_STX: | |
567 | /* check for invalid memory addresses */ | |
93699863 KK |
568 | if (ftest->k >= BPF_MEMWORDS) |
569 | return -EINVAL; | |
570 | break; | |
cba328fc | 571 | case BPF_S_JMP_JA: |
93699863 KK |
572 | /* |
573 | * Note, the large ftest->k might cause loops. | |
574 | * Compare this with conditional jumps below, | |
575 | * where offsets are limited. --ANK (981016) | |
576 | */ | |
95c96174 | 577 | if (ftest->k >= (unsigned int)(flen-pc-1)) |
93699863 | 578 | return -EINVAL; |
01f2f3f6 | 579 | break; |
01f2f3f6 HPP |
580 | case BPF_S_JMP_JEQ_K: |
581 | case BPF_S_JMP_JEQ_X: | |
582 | case BPF_S_JMP_JGE_K: | |
583 | case BPF_S_JMP_JGE_X: | |
584 | case BPF_S_JMP_JGT_K: | |
585 | case BPF_S_JMP_JGT_X: | |
586 | case BPF_S_JMP_JSET_X: | |
587 | case BPF_S_JMP_JSET_K: | |
cba328fc | 588 | /* for conditionals both must be safe */ |
e35bedf3 | 589 | if (pc + ftest->jt + 1 >= flen || |
93699863 KK |
590 | pc + ftest->jf + 1 >= flen) |
591 | return -EINVAL; | |
cba328fc | 592 | break; |
12b16dad ED |
593 | case BPF_S_LD_W_ABS: |
594 | case BPF_S_LD_H_ABS: | |
595 | case BPF_S_LD_B_ABS: | |
aa1113d9 | 596 | anc_found = false; |
12b16dad ED |
597 | #define ANCILLARY(CODE) case SKF_AD_OFF + SKF_AD_##CODE: \ |
598 | code = BPF_S_ANC_##CODE; \ | |
aa1113d9 | 599 | anc_found = true; \ |
12b16dad ED |
600 | break |
601 | switch (ftest->k) { | |
602 | ANCILLARY(PROTOCOL); | |
603 | ANCILLARY(PKTTYPE); | |
604 | ANCILLARY(IFINDEX); | |
605 | ANCILLARY(NLATTR); | |
606 | ANCILLARY(NLATTR_NEST); | |
607 | ANCILLARY(MARK); | |
608 | ANCILLARY(QUEUE); | |
609 | ANCILLARY(HATYPE); | |
610 | ANCILLARY(RXHASH); | |
611 | ANCILLARY(CPU); | |
ffe06c17 | 612 | ANCILLARY(ALU_XOR_X); |
f3335031 ED |
613 | ANCILLARY(VLAN_TAG); |
614 | ANCILLARY(VLAN_TAG_PRESENT); | |
12b16dad | 615 | } |
aa1113d9 DB |
616 | |
617 | /* ancillary operation unknown or unsupported */ | |
618 | if (anc_found == false && ftest->k >= SKF_AD_OFF) | |
619 | return -EINVAL; | |
01f2f3f6 | 620 | } |
cba328fc | 621 | ftest->code = code; |
01f2f3f6 | 622 | } |
93699863 | 623 | |
01f2f3f6 HPP |
624 | /* last instruction must be a RET code */ |
625 | switch (filter[flen - 1].code) { | |
626 | case BPF_S_RET_K: | |
627 | case BPF_S_RET_A: | |
2d5311e4 | 628 | return check_load_and_stores(filter, flen); |
cba328fc TH |
629 | } |
630 | return -EINVAL; | |
1da177e4 | 631 | } |
b715631f | 632 | EXPORT_SYMBOL(sk_chk_filter); |
1da177e4 | 633 | |
47e958ea | 634 | /** |
46bcf14f | 635 | * sk_filter_release_rcu - Release a socket filter by rcu_head |
47e958ea PE |
636 | * @rcu: rcu_head that contains the sk_filter to free |
637 | */ | |
46bcf14f | 638 | void sk_filter_release_rcu(struct rcu_head *rcu) |
47e958ea PE |
639 | { |
640 | struct sk_filter *fp = container_of(rcu, struct sk_filter, rcu); | |
641 | ||
0a14842f | 642 | bpf_jit_free(fp); |
46bcf14f | 643 | kfree(fp); |
47e958ea | 644 | } |
46bcf14f | 645 | EXPORT_SYMBOL(sk_filter_release_rcu); |
47e958ea | 646 | |
302d6637 JP |
647 | static int __sk_prepare_filter(struct sk_filter *fp) |
648 | { | |
649 | int err; | |
650 | ||
651 | fp->bpf_func = sk_run_filter; | |
652 | ||
653 | err = sk_chk_filter(fp->insns, fp->len); | |
654 | if (err) | |
655 | return err; | |
656 | ||
657 | bpf_jit_compile(fp); | |
658 | return 0; | |
659 | } | |
660 | ||
661 | /** | |
662 | * sk_unattached_filter_create - create an unattached filter | |
663 | * @fprog: the filter program | |
c6c4b97c | 664 | * @pfp: the unattached filter that is created |
302d6637 | 665 | * |
c6c4b97c | 666 | * Create a filter independent of any socket. We first run some |
302d6637 JP |
667 | * sanity checks on it to make sure it does not explode on us later. |
668 | * If an error occurs or there is insufficient memory for the filter | |
669 | * a negative errno code is returned. On success the return is zero. | |
670 | */ | |
671 | int sk_unattached_filter_create(struct sk_filter **pfp, | |
672 | struct sock_fprog *fprog) | |
673 | { | |
674 | struct sk_filter *fp; | |
675 | unsigned int fsize = sizeof(struct sock_filter) * fprog->len; | |
676 | int err; | |
677 | ||
678 | /* Make sure new filter is there and in the right amounts. */ | |
679 | if (fprog->filter == NULL) | |
680 | return -EINVAL; | |
681 | ||
682 | fp = kmalloc(fsize + sizeof(*fp), GFP_KERNEL); | |
683 | if (!fp) | |
684 | return -ENOMEM; | |
685 | memcpy(fp->insns, fprog->filter, fsize); | |
686 | ||
687 | atomic_set(&fp->refcnt, 1); | |
688 | fp->len = fprog->len; | |
689 | ||
690 | err = __sk_prepare_filter(fp); | |
691 | if (err) | |
692 | goto free_mem; | |
693 | ||
694 | *pfp = fp; | |
695 | return 0; | |
696 | free_mem: | |
697 | kfree(fp); | |
698 | return err; | |
699 | } | |
700 | EXPORT_SYMBOL_GPL(sk_unattached_filter_create); | |
701 | ||
702 | void sk_unattached_filter_destroy(struct sk_filter *fp) | |
703 | { | |
704 | sk_filter_release(fp); | |
705 | } | |
706 | EXPORT_SYMBOL_GPL(sk_unattached_filter_destroy); | |
707 | ||
1da177e4 LT |
708 | /** |
709 | * sk_attach_filter - attach a socket filter | |
710 | * @fprog: the filter program | |
711 | * @sk: the socket to use | |
712 | * | |
713 | * Attach the user's filter code. We first run some sanity checks on | |
714 | * it to make sure it does not explode on us later. If an error | |
715 | * occurs or there is insufficient memory for the filter a negative | |
716 | * errno code is returned. On success the return is zero. | |
717 | */ | |
718 | int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk) | |
719 | { | |
d3904b73 | 720 | struct sk_filter *fp, *old_fp; |
1da177e4 LT |
721 | unsigned int fsize = sizeof(struct sock_filter) * fprog->len; |
722 | int err; | |
723 | ||
d59577b6 VB |
724 | if (sock_flag(sk, SOCK_FILTER_LOCKED)) |
725 | return -EPERM; | |
726 | ||
1da177e4 | 727 | /* Make sure new filter is there and in the right amounts. */ |
e35bedf3 KK |
728 | if (fprog->filter == NULL) |
729 | return -EINVAL; | |
1da177e4 LT |
730 | |
731 | fp = sock_kmalloc(sk, fsize+sizeof(*fp), GFP_KERNEL); | |
732 | if (!fp) | |
733 | return -ENOMEM; | |
734 | if (copy_from_user(fp->insns, fprog->filter, fsize)) { | |
4ec93edb | 735 | sock_kfree_s(sk, fp, fsize+sizeof(*fp)); |
1da177e4 LT |
736 | return -EFAULT; |
737 | } | |
738 | ||
739 | atomic_set(&fp->refcnt, 1); | |
740 | fp->len = fprog->len; | |
741 | ||
302d6637 | 742 | err = __sk_prepare_filter(fp); |
d3904b73 PE |
743 | if (err) { |
744 | sk_filter_uncharge(sk, fp); | |
745 | return err; | |
1da177e4 LT |
746 | } |
747 | ||
f91ff5b9 ED |
748 | old_fp = rcu_dereference_protected(sk->sk_filter, |
749 | sock_owned_by_user(sk)); | |
d3904b73 | 750 | rcu_assign_pointer(sk->sk_filter, fp); |
d3904b73 | 751 | |
9b013e05 | 752 | if (old_fp) |
46bcf14f | 753 | sk_filter_uncharge(sk, old_fp); |
d3904b73 | 754 | return 0; |
1da177e4 | 755 | } |
5ff3f073 | 756 | EXPORT_SYMBOL_GPL(sk_attach_filter); |
1da177e4 | 757 | |
55b33325 PE |
758 | int sk_detach_filter(struct sock *sk) |
759 | { | |
760 | int ret = -ENOENT; | |
761 | struct sk_filter *filter; | |
762 | ||
d59577b6 VB |
763 | if (sock_flag(sk, SOCK_FILTER_LOCKED)) |
764 | return -EPERM; | |
765 | ||
f91ff5b9 ED |
766 | filter = rcu_dereference_protected(sk->sk_filter, |
767 | sock_owned_by_user(sk)); | |
55b33325 | 768 | if (filter) { |
a9b3cd7f | 769 | RCU_INIT_POINTER(sk->sk_filter, NULL); |
46bcf14f | 770 | sk_filter_uncharge(sk, filter); |
55b33325 PE |
771 | ret = 0; |
772 | } | |
55b33325 PE |
773 | return ret; |
774 | } | |
5ff3f073 | 775 | EXPORT_SYMBOL_GPL(sk_detach_filter); |
a8fc9277 PE |
776 | |
777 | static void sk_decode_filter(struct sock_filter *filt, struct sock_filter *to) | |
778 | { | |
779 | static const u16 decodes[] = { | |
780 | [BPF_S_ALU_ADD_K] = BPF_ALU|BPF_ADD|BPF_K, | |
781 | [BPF_S_ALU_ADD_X] = BPF_ALU|BPF_ADD|BPF_X, | |
782 | [BPF_S_ALU_SUB_K] = BPF_ALU|BPF_SUB|BPF_K, | |
783 | [BPF_S_ALU_SUB_X] = BPF_ALU|BPF_SUB|BPF_X, | |
784 | [BPF_S_ALU_MUL_K] = BPF_ALU|BPF_MUL|BPF_K, | |
785 | [BPF_S_ALU_MUL_X] = BPF_ALU|BPF_MUL|BPF_X, | |
786 | [BPF_S_ALU_DIV_X] = BPF_ALU|BPF_DIV|BPF_X, | |
787 | [BPF_S_ALU_MOD_K] = BPF_ALU|BPF_MOD|BPF_K, | |
788 | [BPF_S_ALU_MOD_X] = BPF_ALU|BPF_MOD|BPF_X, | |
789 | [BPF_S_ALU_AND_K] = BPF_ALU|BPF_AND|BPF_K, | |
790 | [BPF_S_ALU_AND_X] = BPF_ALU|BPF_AND|BPF_X, | |
791 | [BPF_S_ALU_OR_K] = BPF_ALU|BPF_OR|BPF_K, | |
792 | [BPF_S_ALU_OR_X] = BPF_ALU|BPF_OR|BPF_X, | |
793 | [BPF_S_ALU_XOR_K] = BPF_ALU|BPF_XOR|BPF_K, | |
794 | [BPF_S_ALU_XOR_X] = BPF_ALU|BPF_XOR|BPF_X, | |
795 | [BPF_S_ALU_LSH_K] = BPF_ALU|BPF_LSH|BPF_K, | |
796 | [BPF_S_ALU_LSH_X] = BPF_ALU|BPF_LSH|BPF_X, | |
797 | [BPF_S_ALU_RSH_K] = BPF_ALU|BPF_RSH|BPF_K, | |
798 | [BPF_S_ALU_RSH_X] = BPF_ALU|BPF_RSH|BPF_X, | |
799 | [BPF_S_ALU_NEG] = BPF_ALU|BPF_NEG, | |
800 | [BPF_S_LD_W_ABS] = BPF_LD|BPF_W|BPF_ABS, | |
801 | [BPF_S_LD_H_ABS] = BPF_LD|BPF_H|BPF_ABS, | |
802 | [BPF_S_LD_B_ABS] = BPF_LD|BPF_B|BPF_ABS, | |
803 | [BPF_S_ANC_PROTOCOL] = BPF_LD|BPF_B|BPF_ABS, | |
804 | [BPF_S_ANC_PKTTYPE] = BPF_LD|BPF_B|BPF_ABS, | |
805 | [BPF_S_ANC_IFINDEX] = BPF_LD|BPF_B|BPF_ABS, | |
806 | [BPF_S_ANC_NLATTR] = BPF_LD|BPF_B|BPF_ABS, | |
807 | [BPF_S_ANC_NLATTR_NEST] = BPF_LD|BPF_B|BPF_ABS, | |
808 | [BPF_S_ANC_MARK] = BPF_LD|BPF_B|BPF_ABS, | |
809 | [BPF_S_ANC_QUEUE] = BPF_LD|BPF_B|BPF_ABS, | |
810 | [BPF_S_ANC_HATYPE] = BPF_LD|BPF_B|BPF_ABS, | |
811 | [BPF_S_ANC_RXHASH] = BPF_LD|BPF_B|BPF_ABS, | |
812 | [BPF_S_ANC_CPU] = BPF_LD|BPF_B|BPF_ABS, | |
813 | [BPF_S_ANC_ALU_XOR_X] = BPF_LD|BPF_B|BPF_ABS, | |
814 | [BPF_S_ANC_SECCOMP_LD_W] = BPF_LD|BPF_B|BPF_ABS, | |
815 | [BPF_S_ANC_VLAN_TAG] = BPF_LD|BPF_B|BPF_ABS, | |
816 | [BPF_S_ANC_VLAN_TAG_PRESENT] = BPF_LD|BPF_B|BPF_ABS, | |
817 | [BPF_S_LD_W_LEN] = BPF_LD|BPF_W|BPF_LEN, | |
818 | [BPF_S_LD_W_IND] = BPF_LD|BPF_W|BPF_IND, | |
819 | [BPF_S_LD_H_IND] = BPF_LD|BPF_H|BPF_IND, | |
820 | [BPF_S_LD_B_IND] = BPF_LD|BPF_B|BPF_IND, | |
821 | [BPF_S_LD_IMM] = BPF_LD|BPF_IMM, | |
822 | [BPF_S_LDX_W_LEN] = BPF_LDX|BPF_W|BPF_LEN, | |
823 | [BPF_S_LDX_B_MSH] = BPF_LDX|BPF_B|BPF_MSH, | |
824 | [BPF_S_LDX_IMM] = BPF_LDX|BPF_IMM, | |
825 | [BPF_S_MISC_TAX] = BPF_MISC|BPF_TAX, | |
826 | [BPF_S_MISC_TXA] = BPF_MISC|BPF_TXA, | |
827 | [BPF_S_RET_K] = BPF_RET|BPF_K, | |
828 | [BPF_S_RET_A] = BPF_RET|BPF_A, | |
829 | [BPF_S_ALU_DIV_K] = BPF_ALU|BPF_DIV|BPF_K, | |
830 | [BPF_S_LD_MEM] = BPF_LD|BPF_MEM, | |
831 | [BPF_S_LDX_MEM] = BPF_LDX|BPF_MEM, | |
832 | [BPF_S_ST] = BPF_ST, | |
833 | [BPF_S_STX] = BPF_STX, | |
834 | [BPF_S_JMP_JA] = BPF_JMP|BPF_JA, | |
835 | [BPF_S_JMP_JEQ_K] = BPF_JMP|BPF_JEQ|BPF_K, | |
836 | [BPF_S_JMP_JEQ_X] = BPF_JMP|BPF_JEQ|BPF_X, | |
837 | [BPF_S_JMP_JGE_K] = BPF_JMP|BPF_JGE|BPF_K, | |
838 | [BPF_S_JMP_JGE_X] = BPF_JMP|BPF_JGE|BPF_X, | |
839 | [BPF_S_JMP_JGT_K] = BPF_JMP|BPF_JGT|BPF_K, | |
840 | [BPF_S_JMP_JGT_X] = BPF_JMP|BPF_JGT|BPF_X, | |
841 | [BPF_S_JMP_JSET_K] = BPF_JMP|BPF_JSET|BPF_K, | |
842 | [BPF_S_JMP_JSET_X] = BPF_JMP|BPF_JSET|BPF_X, | |
843 | }; | |
844 | u16 code; | |
845 | ||
846 | code = filt->code; | |
847 | ||
848 | to->code = decodes[code]; | |
849 | to->jt = filt->jt; | |
850 | to->jf = filt->jf; | |
851 | ||
852 | if (code == BPF_S_ALU_DIV_K) { | |
853 | /* | |
854 | * When loaded this rule user gave us X, which was | |
855 | * translated into R = r(X). Now we calculate the | |
856 | * RR = r(R) and report it back. If next time this | |
857 | * value is loaded and RRR = r(RR) is calculated | |
858 | * then the R == RRR will be true. | |
859 | * | |
860 | * One exception. X == 1 translates into R == 0 and | |
861 | * we can't calculate RR out of it with r(). | |
862 | */ | |
863 | ||
864 | if (filt->k == 0) | |
865 | to->k = 1; | |
866 | else | |
867 | to->k = reciprocal_value(filt->k); | |
868 | ||
869 | BUG_ON(reciprocal_value(to->k) != filt->k); | |
870 | } else | |
871 | to->k = filt->k; | |
872 | } | |
873 | ||
874 | int sk_get_filter(struct sock *sk, struct sock_filter __user *ubuf, unsigned int len) | |
875 | { | |
876 | struct sk_filter *filter; | |
877 | int i, ret; | |
878 | ||
879 | lock_sock(sk); | |
880 | filter = rcu_dereference_protected(sk->sk_filter, | |
881 | sock_owned_by_user(sk)); | |
882 | ret = 0; | |
883 | if (!filter) | |
884 | goto out; | |
885 | ret = filter->len; | |
886 | if (!len) | |
887 | goto out; | |
888 | ret = -EINVAL; | |
889 | if (len < filter->len) | |
890 | goto out; | |
891 | ||
892 | ret = -EFAULT; | |
893 | for (i = 0; i < filter->len; i++) { | |
894 | struct sock_filter fb; | |
895 | ||
896 | sk_decode_filter(&filter->insns[i], &fb); | |
897 | if (copy_to_user(&ubuf[i], &fb, sizeof(fb))) | |
898 | goto out; | |
899 | } | |
900 | ||
901 | ret = filter->len; | |
902 | out: | |
903 | release_sock(sk); | |
904 | return ret; | |
905 | } |