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iio: imu: inv_mpu6050: test whoami first and against all known values
[mirror_ubuntu-artful-kernel.git] / net / core / filter.c
1 /*
2 * Linux Socket Filter - Kernel level socket filtering
3 *
4 * Based on the design of the Berkeley Packet Filter. The new
5 * internal format has been designed by PLUMgrid:
6 *
7 * Copyright (c) 2011 - 2014 PLUMgrid, http://plumgrid.com
8 *
9 * Authors:
10 *
11 * Jay Schulist <jschlst@samba.org>
12 * Alexei Starovoitov <ast@plumgrid.com>
13 * Daniel Borkmann <dborkman@redhat.com>
14 *
15 * This program is free software; you can redistribute it and/or
16 * modify it under the terms of the GNU General Public License
17 * as published by the Free Software Foundation; either version
18 * 2 of the License, or (at your option) any later version.
19 *
20 * Andi Kleen - Fix a few bad bugs and races.
21 * Kris Katterjohn - Added many additional checks in bpf_check_classic()
22 */
23
24 #include <linux/module.h>
25 #include <linux/types.h>
26 #include <linux/mm.h>
27 #include <linux/fcntl.h>
28 #include <linux/socket.h>
29 #include <linux/sock_diag.h>
30 #include <linux/in.h>
31 #include <linux/inet.h>
32 #include <linux/netdevice.h>
33 #include <linux/if_packet.h>
34 #include <linux/if_arp.h>
35 #include <linux/gfp.h>
36 #include <net/ip.h>
37 #include <net/protocol.h>
38 #include <net/netlink.h>
39 #include <linux/skbuff.h>
40 #include <net/sock.h>
41 #include <net/flow_dissector.h>
42 #include <linux/errno.h>
43 #include <linux/timer.h>
44 #include <linux/uaccess.h>
45 #include <asm/unaligned.h>
46 #include <linux/filter.h>
47 #include <linux/ratelimit.h>
48 #include <linux/seccomp.h>
49 #include <linux/if_vlan.h>
50 #include <linux/bpf.h>
51 #include <net/sch_generic.h>
52 #include <net/cls_cgroup.h>
53 #include <net/dst_metadata.h>
54 #include <net/dst.h>
55 #include <net/sock_reuseport.h>
56 #include <net/busy_poll.h>
57
58 /**
59 * sk_filter_trim_cap - run a packet through a socket filter
60 * @sk: sock associated with &sk_buff
61 * @skb: buffer to filter
62 * @cap: limit on how short the eBPF program may trim the packet
63 *
64 * Run the eBPF program and then cut skb->data to correct size returned by
65 * the program. If pkt_len is 0 we toss packet. If skb->len is smaller
66 * than pkt_len we keep whole skb->data. This is the socket level
67 * wrapper to BPF_PROG_RUN. It returns 0 if the packet should
68 * be accepted or -EPERM if the packet should be tossed.
69 *
70 */
71 int sk_filter_trim_cap(struct sock *sk, struct sk_buff *skb, unsigned int cap)
72 {
73 int err;
74 struct sk_filter *filter;
75
76 /*
77 * If the skb was allocated from pfmemalloc reserves, only
78 * allow SOCK_MEMALLOC sockets to use it as this socket is
79 * helping free memory
80 */
81 if (skb_pfmemalloc(skb) && !sock_flag(sk, SOCK_MEMALLOC)) {
82 NET_INC_STATS(sock_net(sk), LINUX_MIB_PFMEMALLOCDROP);
83 return -ENOMEM;
84 }
85 err = BPF_CGROUP_RUN_PROG_INET_INGRESS(sk, skb);
86 if (err)
87 return err;
88
89 err = security_sock_rcv_skb(sk, skb);
90 if (err)
91 return err;
92
93 rcu_read_lock();
94 filter = rcu_dereference(sk->sk_filter);
95 if (filter) {
96 struct sock *save_sk = skb->sk;
97 unsigned int pkt_len;
98
99 skb->sk = sk;
100 pkt_len = bpf_prog_run_save_cb(filter->prog, skb);
101 skb->sk = save_sk;
102 err = pkt_len ? pskb_trim(skb, max(cap, pkt_len)) : -EPERM;
103 }
104 rcu_read_unlock();
105
106 return err;
107 }
108 EXPORT_SYMBOL(sk_filter_trim_cap);
109
110 BPF_CALL_1(__skb_get_pay_offset, struct sk_buff *, skb)
111 {
112 return skb_get_poff(skb);
113 }
114
115 BPF_CALL_3(__skb_get_nlattr, struct sk_buff *, skb, u32, a, u32, x)
116 {
117 struct nlattr *nla;
118
119 if (skb_is_nonlinear(skb))
120 return 0;
121
122 if (skb->len < sizeof(struct nlattr))
123 return 0;
124
125 if (a > skb->len - sizeof(struct nlattr))
126 return 0;
127
128 nla = nla_find((struct nlattr *) &skb->data[a], skb->len - a, x);
129 if (nla)
130 return (void *) nla - (void *) skb->data;
131
132 return 0;
133 }
134
135 BPF_CALL_3(__skb_get_nlattr_nest, struct sk_buff *, skb, u32, a, u32, x)
136 {
137 struct nlattr *nla;
138
139 if (skb_is_nonlinear(skb))
140 return 0;
141
142 if (skb->len < sizeof(struct nlattr))
143 return 0;
144
145 if (a > skb->len - sizeof(struct nlattr))
146 return 0;
147
148 nla = (struct nlattr *) &skb->data[a];
149 if (nla->nla_len > skb->len - a)
150 return 0;
151
152 nla = nla_find_nested(nla, x);
153 if (nla)
154 return (void *) nla - (void *) skb->data;
155
156 return 0;
157 }
158
159 BPF_CALL_0(__get_raw_cpu_id)
160 {
161 return raw_smp_processor_id();
162 }
163
164 static const struct bpf_func_proto bpf_get_raw_smp_processor_id_proto = {
165 .func = __get_raw_cpu_id,
166 .gpl_only = false,
167 .ret_type = RET_INTEGER,
168 };
169
170 static u32 convert_skb_access(int skb_field, int dst_reg, int src_reg,
171 struct bpf_insn *insn_buf)
172 {
173 struct bpf_insn *insn = insn_buf;
174
175 switch (skb_field) {
176 case SKF_AD_MARK:
177 BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, mark) != 4);
178
179 *insn++ = BPF_LDX_MEM(BPF_W, dst_reg, src_reg,
180 offsetof(struct sk_buff, mark));
181 break;
182
183 case SKF_AD_PKTTYPE:
184 *insn++ = BPF_LDX_MEM(BPF_B, dst_reg, src_reg, PKT_TYPE_OFFSET());
185 *insn++ = BPF_ALU32_IMM(BPF_AND, dst_reg, PKT_TYPE_MAX);
186 #ifdef __BIG_ENDIAN_BITFIELD
187 *insn++ = BPF_ALU32_IMM(BPF_RSH, dst_reg, 5);
188 #endif
189 break;
190
191 case SKF_AD_QUEUE:
192 BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, queue_mapping) != 2);
193
194 *insn++ = BPF_LDX_MEM(BPF_H, dst_reg, src_reg,
195 offsetof(struct sk_buff, queue_mapping));
196 break;
197
198 case SKF_AD_VLAN_TAG:
199 case SKF_AD_VLAN_TAG_PRESENT:
200 BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, vlan_tci) != 2);
201 BUILD_BUG_ON(VLAN_TAG_PRESENT != 0x1000);
202
203 /* dst_reg = *(u16 *) (src_reg + offsetof(vlan_tci)) */
204 *insn++ = BPF_LDX_MEM(BPF_H, dst_reg, src_reg,
205 offsetof(struct sk_buff, vlan_tci));
206 if (skb_field == SKF_AD_VLAN_TAG) {
207 *insn++ = BPF_ALU32_IMM(BPF_AND, dst_reg,
208 ~VLAN_TAG_PRESENT);
209 } else {
210 /* dst_reg >>= 12 */
211 *insn++ = BPF_ALU32_IMM(BPF_RSH, dst_reg, 12);
212 /* dst_reg &= 1 */
213 *insn++ = BPF_ALU32_IMM(BPF_AND, dst_reg, 1);
214 }
215 break;
216 }
217
218 return insn - insn_buf;
219 }
220
221 static bool convert_bpf_extensions(struct sock_filter *fp,
222 struct bpf_insn **insnp)
223 {
224 struct bpf_insn *insn = *insnp;
225 u32 cnt;
226
227 switch (fp->k) {
228 case SKF_AD_OFF + SKF_AD_PROTOCOL:
229 BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, protocol) != 2);
230
231 /* A = *(u16 *) (CTX + offsetof(protocol)) */
232 *insn++ = BPF_LDX_MEM(BPF_H, BPF_REG_A, BPF_REG_CTX,
233 offsetof(struct sk_buff, protocol));
234 /* A = ntohs(A) [emitting a nop or swap16] */
235 *insn = BPF_ENDIAN(BPF_FROM_BE, BPF_REG_A, 16);
236 break;
237
238 case SKF_AD_OFF + SKF_AD_PKTTYPE:
239 cnt = convert_skb_access(SKF_AD_PKTTYPE, BPF_REG_A, BPF_REG_CTX, insn);
240 insn += cnt - 1;
241 break;
242
243 case SKF_AD_OFF + SKF_AD_IFINDEX:
244 case SKF_AD_OFF + SKF_AD_HATYPE:
245 BUILD_BUG_ON(FIELD_SIZEOF(struct net_device, ifindex) != 4);
246 BUILD_BUG_ON(FIELD_SIZEOF(struct net_device, type) != 2);
247
248 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct sk_buff, dev),
249 BPF_REG_TMP, BPF_REG_CTX,
250 offsetof(struct sk_buff, dev));
251 /* if (tmp != 0) goto pc + 1 */
252 *insn++ = BPF_JMP_IMM(BPF_JNE, BPF_REG_TMP, 0, 1);
253 *insn++ = BPF_EXIT_INSN();
254 if (fp->k == SKF_AD_OFF + SKF_AD_IFINDEX)
255 *insn = BPF_LDX_MEM(BPF_W, BPF_REG_A, BPF_REG_TMP,
256 offsetof(struct net_device, ifindex));
257 else
258 *insn = BPF_LDX_MEM(BPF_H, BPF_REG_A, BPF_REG_TMP,
259 offsetof(struct net_device, type));
260 break;
261
262 case SKF_AD_OFF + SKF_AD_MARK:
263 cnt = convert_skb_access(SKF_AD_MARK, BPF_REG_A, BPF_REG_CTX, insn);
264 insn += cnt - 1;
265 break;
266
267 case SKF_AD_OFF + SKF_AD_RXHASH:
268 BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, hash) != 4);
269
270 *insn = BPF_LDX_MEM(BPF_W, BPF_REG_A, BPF_REG_CTX,
271 offsetof(struct sk_buff, hash));
272 break;
273
274 case SKF_AD_OFF + SKF_AD_QUEUE:
275 cnt = convert_skb_access(SKF_AD_QUEUE, BPF_REG_A, BPF_REG_CTX, insn);
276 insn += cnt - 1;
277 break;
278
279 case SKF_AD_OFF + SKF_AD_VLAN_TAG:
280 cnt = convert_skb_access(SKF_AD_VLAN_TAG,
281 BPF_REG_A, BPF_REG_CTX, insn);
282 insn += cnt - 1;
283 break;
284
285 case SKF_AD_OFF + SKF_AD_VLAN_TAG_PRESENT:
286 cnt = convert_skb_access(SKF_AD_VLAN_TAG_PRESENT,
287 BPF_REG_A, BPF_REG_CTX, insn);
288 insn += cnt - 1;
289 break;
290
291 case SKF_AD_OFF + SKF_AD_VLAN_TPID:
292 BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, vlan_proto) != 2);
293
294 /* A = *(u16 *) (CTX + offsetof(vlan_proto)) */
295 *insn++ = BPF_LDX_MEM(BPF_H, BPF_REG_A, BPF_REG_CTX,
296 offsetof(struct sk_buff, vlan_proto));
297 /* A = ntohs(A) [emitting a nop or swap16] */
298 *insn = BPF_ENDIAN(BPF_FROM_BE, BPF_REG_A, 16);
299 break;
300
301 case SKF_AD_OFF + SKF_AD_PAY_OFFSET:
302 case SKF_AD_OFF + SKF_AD_NLATTR:
303 case SKF_AD_OFF + SKF_AD_NLATTR_NEST:
304 case SKF_AD_OFF + SKF_AD_CPU:
305 case SKF_AD_OFF + SKF_AD_RANDOM:
306 /* arg1 = CTX */
307 *insn++ = BPF_MOV64_REG(BPF_REG_ARG1, BPF_REG_CTX);
308 /* arg2 = A */
309 *insn++ = BPF_MOV64_REG(BPF_REG_ARG2, BPF_REG_A);
310 /* arg3 = X */
311 *insn++ = BPF_MOV64_REG(BPF_REG_ARG3, BPF_REG_X);
312 /* Emit call(arg1=CTX, arg2=A, arg3=X) */
313 switch (fp->k) {
314 case SKF_AD_OFF + SKF_AD_PAY_OFFSET:
315 *insn = BPF_EMIT_CALL(__skb_get_pay_offset);
316 break;
317 case SKF_AD_OFF + SKF_AD_NLATTR:
318 *insn = BPF_EMIT_CALL(__skb_get_nlattr);
319 break;
320 case SKF_AD_OFF + SKF_AD_NLATTR_NEST:
321 *insn = BPF_EMIT_CALL(__skb_get_nlattr_nest);
322 break;
323 case SKF_AD_OFF + SKF_AD_CPU:
324 *insn = BPF_EMIT_CALL(__get_raw_cpu_id);
325 break;
326 case SKF_AD_OFF + SKF_AD_RANDOM:
327 *insn = BPF_EMIT_CALL(bpf_user_rnd_u32);
328 bpf_user_rnd_init_once();
329 break;
330 }
331 break;
332
333 case SKF_AD_OFF + SKF_AD_ALU_XOR_X:
334 /* A ^= X */
335 *insn = BPF_ALU32_REG(BPF_XOR, BPF_REG_A, BPF_REG_X);
336 break;
337
338 default:
339 /* This is just a dummy call to avoid letting the compiler
340 * evict __bpf_call_base() as an optimization. Placed here
341 * where no-one bothers.
342 */
343 BUG_ON(__bpf_call_base(0, 0, 0, 0, 0) != 0);
344 return false;
345 }
346
347 *insnp = insn;
348 return true;
349 }
350
351 /**
352 * bpf_convert_filter - convert filter program
353 * @prog: the user passed filter program
354 * @len: the length of the user passed filter program
355 * @new_prog: buffer where converted program will be stored
356 * @new_len: pointer to store length of converted program
357 *
358 * Remap 'sock_filter' style classic BPF (cBPF) instruction set to 'bpf_insn'
359 * style extended BPF (eBPF).
360 * Conversion workflow:
361 *
362 * 1) First pass for calculating the new program length:
363 * bpf_convert_filter(old_prog, old_len, NULL, &new_len)
364 *
365 * 2) 2nd pass to remap in two passes: 1st pass finds new
366 * jump offsets, 2nd pass remapping:
367 * new_prog = kmalloc(sizeof(struct bpf_insn) * new_len);
368 * bpf_convert_filter(old_prog, old_len, new_prog, &new_len);
369 */
370 static int bpf_convert_filter(struct sock_filter *prog, int len,
371 struct bpf_insn *new_prog, int *new_len)
372 {
373 int new_flen = 0, pass = 0, target, i;
374 struct bpf_insn *new_insn;
375 struct sock_filter *fp;
376 int *addrs = NULL;
377 u8 bpf_src;
378
379 BUILD_BUG_ON(BPF_MEMWORDS * sizeof(u32) > MAX_BPF_STACK);
380 BUILD_BUG_ON(BPF_REG_FP + 1 != MAX_BPF_REG);
381
382 if (len <= 0 || len > BPF_MAXINSNS)
383 return -EINVAL;
384
385 if (new_prog) {
386 addrs = kcalloc(len, sizeof(*addrs),
387 GFP_KERNEL | __GFP_NOWARN);
388 if (!addrs)
389 return -ENOMEM;
390 }
391
392 do_pass:
393 new_insn = new_prog;
394 fp = prog;
395
396 /* Classic BPF related prologue emission. */
397 if (new_insn) {
398 /* Classic BPF expects A and X to be reset first. These need
399 * to be guaranteed to be the first two instructions.
400 */
401 *new_insn++ = BPF_ALU64_REG(BPF_XOR, BPF_REG_A, BPF_REG_A);
402 *new_insn++ = BPF_ALU64_REG(BPF_XOR, BPF_REG_X, BPF_REG_X);
403
404 /* All programs must keep CTX in callee saved BPF_REG_CTX.
405 * In eBPF case it's done by the compiler, here we need to
406 * do this ourself. Initial CTX is present in BPF_REG_ARG1.
407 */
408 *new_insn++ = BPF_MOV64_REG(BPF_REG_CTX, BPF_REG_ARG1);
409 } else {
410 new_insn += 3;
411 }
412
413 for (i = 0; i < len; fp++, i++) {
414 struct bpf_insn tmp_insns[6] = { };
415 struct bpf_insn *insn = tmp_insns;
416
417 if (addrs)
418 addrs[i] = new_insn - new_prog;
419
420 switch (fp->code) {
421 /* All arithmetic insns and skb loads map as-is. */
422 case BPF_ALU | BPF_ADD | BPF_X:
423 case BPF_ALU | BPF_ADD | BPF_K:
424 case BPF_ALU | BPF_SUB | BPF_X:
425 case BPF_ALU | BPF_SUB | BPF_K:
426 case BPF_ALU | BPF_AND | BPF_X:
427 case BPF_ALU | BPF_AND | BPF_K:
428 case BPF_ALU | BPF_OR | BPF_X:
429 case BPF_ALU | BPF_OR | BPF_K:
430 case BPF_ALU | BPF_LSH | BPF_X:
431 case BPF_ALU | BPF_LSH | BPF_K:
432 case BPF_ALU | BPF_RSH | BPF_X:
433 case BPF_ALU | BPF_RSH | BPF_K:
434 case BPF_ALU | BPF_XOR | BPF_X:
435 case BPF_ALU | BPF_XOR | BPF_K:
436 case BPF_ALU | BPF_MUL | BPF_X:
437 case BPF_ALU | BPF_MUL | BPF_K:
438 case BPF_ALU | BPF_DIV | BPF_X:
439 case BPF_ALU | BPF_DIV | BPF_K:
440 case BPF_ALU | BPF_MOD | BPF_X:
441 case BPF_ALU | BPF_MOD | BPF_K:
442 case BPF_ALU | BPF_NEG:
443 case BPF_LD | BPF_ABS | BPF_W:
444 case BPF_LD | BPF_ABS | BPF_H:
445 case BPF_LD | BPF_ABS | BPF_B:
446 case BPF_LD | BPF_IND | BPF_W:
447 case BPF_LD | BPF_IND | BPF_H:
448 case BPF_LD | BPF_IND | BPF_B:
449 /* Check for overloaded BPF extension and
450 * directly convert it if found, otherwise
451 * just move on with mapping.
452 */
453 if (BPF_CLASS(fp->code) == BPF_LD &&
454 BPF_MODE(fp->code) == BPF_ABS &&
455 convert_bpf_extensions(fp, &insn))
456 break;
457
458 *insn = BPF_RAW_INSN(fp->code, BPF_REG_A, BPF_REG_X, 0, fp->k);
459 break;
460
461 /* Jump transformation cannot use BPF block macros
462 * everywhere as offset calculation and target updates
463 * require a bit more work than the rest, i.e. jump
464 * opcodes map as-is, but offsets need adjustment.
465 */
466
467 #define BPF_EMIT_JMP \
468 do { \
469 if (target >= len || target < 0) \
470 goto err; \
471 insn->off = addrs ? addrs[target] - addrs[i] - 1 : 0; \
472 /* Adjust pc relative offset for 2nd or 3rd insn. */ \
473 insn->off -= insn - tmp_insns; \
474 } while (0)
475
476 case BPF_JMP | BPF_JA:
477 target = i + fp->k + 1;
478 insn->code = fp->code;
479 BPF_EMIT_JMP;
480 break;
481
482 case BPF_JMP | BPF_JEQ | BPF_K:
483 case BPF_JMP | BPF_JEQ | BPF_X:
484 case BPF_JMP | BPF_JSET | BPF_K:
485 case BPF_JMP | BPF_JSET | BPF_X:
486 case BPF_JMP | BPF_JGT | BPF_K:
487 case BPF_JMP | BPF_JGT | BPF_X:
488 case BPF_JMP | BPF_JGE | BPF_K:
489 case BPF_JMP | BPF_JGE | BPF_X:
490 if (BPF_SRC(fp->code) == BPF_K && (int) fp->k < 0) {
491 /* BPF immediates are signed, zero extend
492 * immediate into tmp register and use it
493 * in compare insn.
494 */
495 *insn++ = BPF_MOV32_IMM(BPF_REG_TMP, fp->k);
496
497 insn->dst_reg = BPF_REG_A;
498 insn->src_reg = BPF_REG_TMP;
499 bpf_src = BPF_X;
500 } else {
501 insn->dst_reg = BPF_REG_A;
502 insn->imm = fp->k;
503 bpf_src = BPF_SRC(fp->code);
504 insn->src_reg = bpf_src == BPF_X ? BPF_REG_X : 0;
505 }
506
507 /* Common case where 'jump_false' is next insn. */
508 if (fp->jf == 0) {
509 insn->code = BPF_JMP | BPF_OP(fp->code) | bpf_src;
510 target = i + fp->jt + 1;
511 BPF_EMIT_JMP;
512 break;
513 }
514
515 /* Convert JEQ into JNE when 'jump_true' is next insn. */
516 if (fp->jt == 0 && BPF_OP(fp->code) == BPF_JEQ) {
517 insn->code = BPF_JMP | BPF_JNE | bpf_src;
518 target = i + fp->jf + 1;
519 BPF_EMIT_JMP;
520 break;
521 }
522
523 /* Other jumps are mapped into two insns: Jxx and JA. */
524 target = i + fp->jt + 1;
525 insn->code = BPF_JMP | BPF_OP(fp->code) | bpf_src;
526 BPF_EMIT_JMP;
527 insn++;
528
529 insn->code = BPF_JMP | BPF_JA;
530 target = i + fp->jf + 1;
531 BPF_EMIT_JMP;
532 break;
533
534 /* ldxb 4 * ([14] & 0xf) is remaped into 6 insns. */
535 case BPF_LDX | BPF_MSH | BPF_B:
536 /* tmp = A */
537 *insn++ = BPF_MOV64_REG(BPF_REG_TMP, BPF_REG_A);
538 /* A = BPF_R0 = *(u8 *) (skb->data + K) */
539 *insn++ = BPF_LD_ABS(BPF_B, fp->k);
540 /* A &= 0xf */
541 *insn++ = BPF_ALU32_IMM(BPF_AND, BPF_REG_A, 0xf);
542 /* A <<= 2 */
543 *insn++ = BPF_ALU32_IMM(BPF_LSH, BPF_REG_A, 2);
544 /* X = A */
545 *insn++ = BPF_MOV64_REG(BPF_REG_X, BPF_REG_A);
546 /* A = tmp */
547 *insn = BPF_MOV64_REG(BPF_REG_A, BPF_REG_TMP);
548 break;
549
550 /* RET_K is remaped into 2 insns. RET_A case doesn't need an
551 * extra mov as BPF_REG_0 is already mapped into BPF_REG_A.
552 */
553 case BPF_RET | BPF_A:
554 case BPF_RET | BPF_K:
555 if (BPF_RVAL(fp->code) == BPF_K)
556 *insn++ = BPF_MOV32_RAW(BPF_K, BPF_REG_0,
557 0, fp->k);
558 *insn = BPF_EXIT_INSN();
559 break;
560
561 /* Store to stack. */
562 case BPF_ST:
563 case BPF_STX:
564 *insn = BPF_STX_MEM(BPF_W, BPF_REG_FP, BPF_CLASS(fp->code) ==
565 BPF_ST ? BPF_REG_A : BPF_REG_X,
566 -(BPF_MEMWORDS - fp->k) * 4);
567 break;
568
569 /* Load from stack. */
570 case BPF_LD | BPF_MEM:
571 case BPF_LDX | BPF_MEM:
572 *insn = BPF_LDX_MEM(BPF_W, BPF_CLASS(fp->code) == BPF_LD ?
573 BPF_REG_A : BPF_REG_X, BPF_REG_FP,
574 -(BPF_MEMWORDS - fp->k) * 4);
575 break;
576
577 /* A = K or X = K */
578 case BPF_LD | BPF_IMM:
579 case BPF_LDX | BPF_IMM:
580 *insn = BPF_MOV32_IMM(BPF_CLASS(fp->code) == BPF_LD ?
581 BPF_REG_A : BPF_REG_X, fp->k);
582 break;
583
584 /* X = A */
585 case BPF_MISC | BPF_TAX:
586 *insn = BPF_MOV64_REG(BPF_REG_X, BPF_REG_A);
587 break;
588
589 /* A = X */
590 case BPF_MISC | BPF_TXA:
591 *insn = BPF_MOV64_REG(BPF_REG_A, BPF_REG_X);
592 break;
593
594 /* A = skb->len or X = skb->len */
595 case BPF_LD | BPF_W | BPF_LEN:
596 case BPF_LDX | BPF_W | BPF_LEN:
597 *insn = BPF_LDX_MEM(BPF_W, BPF_CLASS(fp->code) == BPF_LD ?
598 BPF_REG_A : BPF_REG_X, BPF_REG_CTX,
599 offsetof(struct sk_buff, len));
600 break;
601
602 /* Access seccomp_data fields. */
603 case BPF_LDX | BPF_ABS | BPF_W:
604 /* A = *(u32 *) (ctx + K) */
605 *insn = BPF_LDX_MEM(BPF_W, BPF_REG_A, BPF_REG_CTX, fp->k);
606 break;
607
608 /* Unknown instruction. */
609 default:
610 goto err;
611 }
612
613 insn++;
614 if (new_prog)
615 memcpy(new_insn, tmp_insns,
616 sizeof(*insn) * (insn - tmp_insns));
617 new_insn += insn - tmp_insns;
618 }
619
620 if (!new_prog) {
621 /* Only calculating new length. */
622 *new_len = new_insn - new_prog;
623 return 0;
624 }
625
626 pass++;
627 if (new_flen != new_insn - new_prog) {
628 new_flen = new_insn - new_prog;
629 if (pass > 2)
630 goto err;
631 goto do_pass;
632 }
633
634 kfree(addrs);
635 BUG_ON(*new_len != new_flen);
636 return 0;
637 err:
638 kfree(addrs);
639 return -EINVAL;
640 }
641
642 /* Security:
643 *
644 * As we dont want to clear mem[] array for each packet going through
645 * __bpf_prog_run(), we check that filter loaded by user never try to read
646 * a cell if not previously written, and we check all branches to be sure
647 * a malicious user doesn't try to abuse us.
648 */
649 static int check_load_and_stores(const struct sock_filter *filter, int flen)
650 {
651 u16 *masks, memvalid = 0; /* One bit per cell, 16 cells */
652 int pc, ret = 0;
653
654 BUILD_BUG_ON(BPF_MEMWORDS > 16);
655
656 masks = kmalloc_array(flen, sizeof(*masks), GFP_KERNEL);
657 if (!masks)
658 return -ENOMEM;
659
660 memset(masks, 0xff, flen * sizeof(*masks));
661
662 for (pc = 0; pc < flen; pc++) {
663 memvalid &= masks[pc];
664
665 switch (filter[pc].code) {
666 case BPF_ST:
667 case BPF_STX:
668 memvalid |= (1 << filter[pc].k);
669 break;
670 case BPF_LD | BPF_MEM:
671 case BPF_LDX | BPF_MEM:
672 if (!(memvalid & (1 << filter[pc].k))) {
673 ret = -EINVAL;
674 goto error;
675 }
676 break;
677 case BPF_JMP | BPF_JA:
678 /* A jump must set masks on target */
679 masks[pc + 1 + filter[pc].k] &= memvalid;
680 memvalid = ~0;
681 break;
682 case BPF_JMP | BPF_JEQ | BPF_K:
683 case BPF_JMP | BPF_JEQ | BPF_X:
684 case BPF_JMP | BPF_JGE | BPF_K:
685 case BPF_JMP | BPF_JGE | BPF_X:
686 case BPF_JMP | BPF_JGT | BPF_K:
687 case BPF_JMP | BPF_JGT | BPF_X:
688 case BPF_JMP | BPF_JSET | BPF_K:
689 case BPF_JMP | BPF_JSET | BPF_X:
690 /* A jump must set masks on targets */
691 masks[pc + 1 + filter[pc].jt] &= memvalid;
692 masks[pc + 1 + filter[pc].jf] &= memvalid;
693 memvalid = ~0;
694 break;
695 }
696 }
697 error:
698 kfree(masks);
699 return ret;
700 }
701
702 static bool chk_code_allowed(u16 code_to_probe)
703 {
704 static const bool codes[] = {
705 /* 32 bit ALU operations */
706 [BPF_ALU | BPF_ADD | BPF_K] = true,
707 [BPF_ALU | BPF_ADD | BPF_X] = true,
708 [BPF_ALU | BPF_SUB | BPF_K] = true,
709 [BPF_ALU | BPF_SUB | BPF_X] = true,
710 [BPF_ALU | BPF_MUL | BPF_K] = true,
711 [BPF_ALU | BPF_MUL | BPF_X] = true,
712 [BPF_ALU | BPF_DIV | BPF_K] = true,
713 [BPF_ALU | BPF_DIV | BPF_X] = true,
714 [BPF_ALU | BPF_MOD | BPF_K] = true,
715 [BPF_ALU | BPF_MOD | BPF_X] = true,
716 [BPF_ALU | BPF_AND | BPF_K] = true,
717 [BPF_ALU | BPF_AND | BPF_X] = true,
718 [BPF_ALU | BPF_OR | BPF_K] = true,
719 [BPF_ALU | BPF_OR | BPF_X] = true,
720 [BPF_ALU | BPF_XOR | BPF_K] = true,
721 [BPF_ALU | BPF_XOR | BPF_X] = true,
722 [BPF_ALU | BPF_LSH | BPF_K] = true,
723 [BPF_ALU | BPF_LSH | BPF_X] = true,
724 [BPF_ALU | BPF_RSH | BPF_K] = true,
725 [BPF_ALU | BPF_RSH | BPF_X] = true,
726 [BPF_ALU | BPF_NEG] = true,
727 /* Load instructions */
728 [BPF_LD | BPF_W | BPF_ABS] = true,
729 [BPF_LD | BPF_H | BPF_ABS] = true,
730 [BPF_LD | BPF_B | BPF_ABS] = true,
731 [BPF_LD | BPF_W | BPF_LEN] = true,
732 [BPF_LD | BPF_W | BPF_IND] = true,
733 [BPF_LD | BPF_H | BPF_IND] = true,
734 [BPF_LD | BPF_B | BPF_IND] = true,
735 [BPF_LD | BPF_IMM] = true,
736 [BPF_LD | BPF_MEM] = true,
737 [BPF_LDX | BPF_W | BPF_LEN] = true,
738 [BPF_LDX | BPF_B | BPF_MSH] = true,
739 [BPF_LDX | BPF_IMM] = true,
740 [BPF_LDX | BPF_MEM] = true,
741 /* Store instructions */
742 [BPF_ST] = true,
743 [BPF_STX] = true,
744 /* Misc instructions */
745 [BPF_MISC | BPF_TAX] = true,
746 [BPF_MISC | BPF_TXA] = true,
747 /* Return instructions */
748 [BPF_RET | BPF_K] = true,
749 [BPF_RET | BPF_A] = true,
750 /* Jump instructions */
751 [BPF_JMP | BPF_JA] = true,
752 [BPF_JMP | BPF_JEQ | BPF_K] = true,
753 [BPF_JMP | BPF_JEQ | BPF_X] = true,
754 [BPF_JMP | BPF_JGE | BPF_K] = true,
755 [BPF_JMP | BPF_JGE | BPF_X] = true,
756 [BPF_JMP | BPF_JGT | BPF_K] = true,
757 [BPF_JMP | BPF_JGT | BPF_X] = true,
758 [BPF_JMP | BPF_JSET | BPF_K] = true,
759 [BPF_JMP | BPF_JSET | BPF_X] = true,
760 };
761
762 if (code_to_probe >= ARRAY_SIZE(codes))
763 return false;
764
765 return codes[code_to_probe];
766 }
767
768 static bool bpf_check_basics_ok(const struct sock_filter *filter,
769 unsigned int flen)
770 {
771 if (filter == NULL)
772 return false;
773 if (flen == 0 || flen > BPF_MAXINSNS)
774 return false;
775
776 return true;
777 }
778
779 /**
780 * bpf_check_classic - verify socket filter code
781 * @filter: filter to verify
782 * @flen: length of filter
783 *
784 * Check the user's filter code. If we let some ugly
785 * filter code slip through kaboom! The filter must contain
786 * no references or jumps that are out of range, no illegal
787 * instructions, and must end with a RET instruction.
788 *
789 * All jumps are forward as they are not signed.
790 *
791 * Returns 0 if the rule set is legal or -EINVAL if not.
792 */
793 static int bpf_check_classic(const struct sock_filter *filter,
794 unsigned int flen)
795 {
796 bool anc_found;
797 int pc;
798
799 /* Check the filter code now */
800 for (pc = 0; pc < flen; pc++) {
801 const struct sock_filter *ftest = &filter[pc];
802
803 /* May we actually operate on this code? */
804 if (!chk_code_allowed(ftest->code))
805 return -EINVAL;
806
807 /* Some instructions need special checks */
808 switch (ftest->code) {
809 case BPF_ALU | BPF_DIV | BPF_K:
810 case BPF_ALU | BPF_MOD | BPF_K:
811 /* Check for division by zero */
812 if (ftest->k == 0)
813 return -EINVAL;
814 break;
815 case BPF_ALU | BPF_LSH | BPF_K:
816 case BPF_ALU | BPF_RSH | BPF_K:
817 if (ftest->k >= 32)
818 return -EINVAL;
819 break;
820 case BPF_LD | BPF_MEM:
821 case BPF_LDX | BPF_MEM:
822 case BPF_ST:
823 case BPF_STX:
824 /* Check for invalid memory addresses */
825 if (ftest->k >= BPF_MEMWORDS)
826 return -EINVAL;
827 break;
828 case BPF_JMP | BPF_JA:
829 /* Note, the large ftest->k might cause loops.
830 * Compare this with conditional jumps below,
831 * where offsets are limited. --ANK (981016)
832 */
833 if (ftest->k >= (unsigned int)(flen - pc - 1))
834 return -EINVAL;
835 break;
836 case BPF_JMP | BPF_JEQ | BPF_K:
837 case BPF_JMP | BPF_JEQ | BPF_X:
838 case BPF_JMP | BPF_JGE | BPF_K:
839 case BPF_JMP | BPF_JGE | BPF_X:
840 case BPF_JMP | BPF_JGT | BPF_K:
841 case BPF_JMP | BPF_JGT | BPF_X:
842 case BPF_JMP | BPF_JSET | BPF_K:
843 case BPF_JMP | BPF_JSET | BPF_X:
844 /* Both conditionals must be safe */
845 if (pc + ftest->jt + 1 >= flen ||
846 pc + ftest->jf + 1 >= flen)
847 return -EINVAL;
848 break;
849 case BPF_LD | BPF_W | BPF_ABS:
850 case BPF_LD | BPF_H | BPF_ABS:
851 case BPF_LD | BPF_B | BPF_ABS:
852 anc_found = false;
853 if (bpf_anc_helper(ftest) & BPF_ANC)
854 anc_found = true;
855 /* Ancillary operation unknown or unsupported */
856 if (anc_found == false && ftest->k >= SKF_AD_OFF)
857 return -EINVAL;
858 }
859 }
860
861 /* Last instruction must be a RET code */
862 switch (filter[flen - 1].code) {
863 case BPF_RET | BPF_K:
864 case BPF_RET | BPF_A:
865 return check_load_and_stores(filter, flen);
866 }
867
868 return -EINVAL;
869 }
870
871 static int bpf_prog_store_orig_filter(struct bpf_prog *fp,
872 const struct sock_fprog *fprog)
873 {
874 unsigned int fsize = bpf_classic_proglen(fprog);
875 struct sock_fprog_kern *fkprog;
876
877 fp->orig_prog = kmalloc(sizeof(*fkprog), GFP_KERNEL);
878 if (!fp->orig_prog)
879 return -ENOMEM;
880
881 fkprog = fp->orig_prog;
882 fkprog->len = fprog->len;
883
884 fkprog->filter = kmemdup(fp->insns, fsize,
885 GFP_KERNEL | __GFP_NOWARN);
886 if (!fkprog->filter) {
887 kfree(fp->orig_prog);
888 return -ENOMEM;
889 }
890
891 return 0;
892 }
893
894 static void bpf_release_orig_filter(struct bpf_prog *fp)
895 {
896 struct sock_fprog_kern *fprog = fp->orig_prog;
897
898 if (fprog) {
899 kfree(fprog->filter);
900 kfree(fprog);
901 }
902 }
903
904 static void __bpf_prog_release(struct bpf_prog *prog)
905 {
906 if (prog->type == BPF_PROG_TYPE_SOCKET_FILTER) {
907 bpf_prog_put(prog);
908 } else {
909 bpf_release_orig_filter(prog);
910 bpf_prog_free(prog);
911 }
912 }
913
914 static void __sk_filter_release(struct sk_filter *fp)
915 {
916 __bpf_prog_release(fp->prog);
917 kfree(fp);
918 }
919
920 /**
921 * sk_filter_release_rcu - Release a socket filter by rcu_head
922 * @rcu: rcu_head that contains the sk_filter to free
923 */
924 static void sk_filter_release_rcu(struct rcu_head *rcu)
925 {
926 struct sk_filter *fp = container_of(rcu, struct sk_filter, rcu);
927
928 __sk_filter_release(fp);
929 }
930
931 /**
932 * sk_filter_release - release a socket filter
933 * @fp: filter to remove
934 *
935 * Remove a filter from a socket and release its resources.
936 */
937 static void sk_filter_release(struct sk_filter *fp)
938 {
939 if (refcount_dec_and_test(&fp->refcnt))
940 call_rcu(&fp->rcu, sk_filter_release_rcu);
941 }
942
943 void sk_filter_uncharge(struct sock *sk, struct sk_filter *fp)
944 {
945 u32 filter_size = bpf_prog_size(fp->prog->len);
946
947 atomic_sub(filter_size, &sk->sk_omem_alloc);
948 sk_filter_release(fp);
949 }
950
951 /* try to charge the socket memory if there is space available
952 * return true on success
953 */
954 static bool __sk_filter_charge(struct sock *sk, struct sk_filter *fp)
955 {
956 u32 filter_size = bpf_prog_size(fp->prog->len);
957
958 /* same check as in sock_kmalloc() */
959 if (filter_size <= sysctl_optmem_max &&
960 atomic_read(&sk->sk_omem_alloc) + filter_size < sysctl_optmem_max) {
961 atomic_add(filter_size, &sk->sk_omem_alloc);
962 return true;
963 }
964 return false;
965 }
966
967 bool sk_filter_charge(struct sock *sk, struct sk_filter *fp)
968 {
969 bool ret = __sk_filter_charge(sk, fp);
970 if (ret)
971 refcount_inc(&fp->refcnt);
972 return ret;
973 }
974
975 static struct bpf_prog *bpf_migrate_filter(struct bpf_prog *fp)
976 {
977 struct sock_filter *old_prog;
978 struct bpf_prog *old_fp;
979 int err, new_len, old_len = fp->len;
980
981 /* We are free to overwrite insns et al right here as it
982 * won't be used at this point in time anymore internally
983 * after the migration to the internal BPF instruction
984 * representation.
985 */
986 BUILD_BUG_ON(sizeof(struct sock_filter) !=
987 sizeof(struct bpf_insn));
988
989 /* Conversion cannot happen on overlapping memory areas,
990 * so we need to keep the user BPF around until the 2nd
991 * pass. At this time, the user BPF is stored in fp->insns.
992 */
993 old_prog = kmemdup(fp->insns, old_len * sizeof(struct sock_filter),
994 GFP_KERNEL | __GFP_NOWARN);
995 if (!old_prog) {
996 err = -ENOMEM;
997 goto out_err;
998 }
999
1000 /* 1st pass: calculate the new program length. */
1001 err = bpf_convert_filter(old_prog, old_len, NULL, &new_len);
1002 if (err)
1003 goto out_err_free;
1004
1005 /* Expand fp for appending the new filter representation. */
1006 old_fp = fp;
1007 fp = bpf_prog_realloc(old_fp, bpf_prog_size(new_len), 0);
1008 if (!fp) {
1009 /* The old_fp is still around in case we couldn't
1010 * allocate new memory, so uncharge on that one.
1011 */
1012 fp = old_fp;
1013 err = -ENOMEM;
1014 goto out_err_free;
1015 }
1016
1017 fp->len = new_len;
1018
1019 /* 2nd pass: remap sock_filter insns into bpf_insn insns. */
1020 err = bpf_convert_filter(old_prog, old_len, fp->insnsi, &new_len);
1021 if (err)
1022 /* 2nd bpf_convert_filter() can fail only if it fails
1023 * to allocate memory, remapping must succeed. Note,
1024 * that at this time old_fp has already been released
1025 * by krealloc().
1026 */
1027 goto out_err_free;
1028
1029 /* We are guaranteed to never error here with cBPF to eBPF
1030 * transitions, since there's no issue with type compatibility
1031 * checks on program arrays.
1032 */
1033 fp = bpf_prog_select_runtime(fp, &err);
1034
1035 kfree(old_prog);
1036 return fp;
1037
1038 out_err_free:
1039 kfree(old_prog);
1040 out_err:
1041 __bpf_prog_release(fp);
1042 return ERR_PTR(err);
1043 }
1044
1045 static struct bpf_prog *bpf_prepare_filter(struct bpf_prog *fp,
1046 bpf_aux_classic_check_t trans)
1047 {
1048 int err;
1049
1050 fp->bpf_func = NULL;
1051 fp->jited = 0;
1052
1053 err = bpf_check_classic(fp->insns, fp->len);
1054 if (err) {
1055 __bpf_prog_release(fp);
1056 return ERR_PTR(err);
1057 }
1058
1059 /* There might be additional checks and transformations
1060 * needed on classic filters, f.e. in case of seccomp.
1061 */
1062 if (trans) {
1063 err = trans(fp->insns, fp->len);
1064 if (err) {
1065 __bpf_prog_release(fp);
1066 return ERR_PTR(err);
1067 }
1068 }
1069
1070 /* Probe if we can JIT compile the filter and if so, do
1071 * the compilation of the filter.
1072 */
1073 bpf_jit_compile(fp);
1074
1075 /* JIT compiler couldn't process this filter, so do the
1076 * internal BPF translation for the optimized interpreter.
1077 */
1078 if (!fp->jited)
1079 fp = bpf_migrate_filter(fp);
1080
1081 return fp;
1082 }
1083
1084 /**
1085 * bpf_prog_create - create an unattached filter
1086 * @pfp: the unattached filter that is created
1087 * @fprog: the filter program
1088 *
1089 * Create a filter independent of any socket. We first run some
1090 * sanity checks on it to make sure it does not explode on us later.
1091 * If an error occurs or there is insufficient memory for the filter
1092 * a negative errno code is returned. On success the return is zero.
1093 */
1094 int bpf_prog_create(struct bpf_prog **pfp, struct sock_fprog_kern *fprog)
1095 {
1096 unsigned int fsize = bpf_classic_proglen(fprog);
1097 struct bpf_prog *fp;
1098
1099 /* Make sure new filter is there and in the right amounts. */
1100 if (!bpf_check_basics_ok(fprog->filter, fprog->len))
1101 return -EINVAL;
1102
1103 fp = bpf_prog_alloc(bpf_prog_size(fprog->len), 0);
1104 if (!fp)
1105 return -ENOMEM;
1106
1107 memcpy(fp->insns, fprog->filter, fsize);
1108
1109 fp->len = fprog->len;
1110 /* Since unattached filters are not copied back to user
1111 * space through sk_get_filter(), we do not need to hold
1112 * a copy here, and can spare us the work.
1113 */
1114 fp->orig_prog = NULL;
1115
1116 /* bpf_prepare_filter() already takes care of freeing
1117 * memory in case something goes wrong.
1118 */
1119 fp = bpf_prepare_filter(fp, NULL);
1120 if (IS_ERR(fp))
1121 return PTR_ERR(fp);
1122
1123 *pfp = fp;
1124 return 0;
1125 }
1126 EXPORT_SYMBOL_GPL(bpf_prog_create);
1127
1128 /**
1129 * bpf_prog_create_from_user - create an unattached filter from user buffer
1130 * @pfp: the unattached filter that is created
1131 * @fprog: the filter program
1132 * @trans: post-classic verifier transformation handler
1133 * @save_orig: save classic BPF program
1134 *
1135 * This function effectively does the same as bpf_prog_create(), only
1136 * that it builds up its insns buffer from user space provided buffer.
1137 * It also allows for passing a bpf_aux_classic_check_t handler.
1138 */
1139 int bpf_prog_create_from_user(struct bpf_prog **pfp, struct sock_fprog *fprog,
1140 bpf_aux_classic_check_t trans, bool save_orig)
1141 {
1142 unsigned int fsize = bpf_classic_proglen(fprog);
1143 struct bpf_prog *fp;
1144 int err;
1145
1146 /* Make sure new filter is there and in the right amounts. */
1147 if (!bpf_check_basics_ok(fprog->filter, fprog->len))
1148 return -EINVAL;
1149
1150 fp = bpf_prog_alloc(bpf_prog_size(fprog->len), 0);
1151 if (!fp)
1152 return -ENOMEM;
1153
1154 if (copy_from_user(fp->insns, fprog->filter, fsize)) {
1155 __bpf_prog_free(fp);
1156 return -EFAULT;
1157 }
1158
1159 fp->len = fprog->len;
1160 fp->orig_prog = NULL;
1161
1162 if (save_orig) {
1163 err = bpf_prog_store_orig_filter(fp, fprog);
1164 if (err) {
1165 __bpf_prog_free(fp);
1166 return -ENOMEM;
1167 }
1168 }
1169
1170 /* bpf_prepare_filter() already takes care of freeing
1171 * memory in case something goes wrong.
1172 */
1173 fp = bpf_prepare_filter(fp, trans);
1174 if (IS_ERR(fp))
1175 return PTR_ERR(fp);
1176
1177 *pfp = fp;
1178 return 0;
1179 }
1180 EXPORT_SYMBOL_GPL(bpf_prog_create_from_user);
1181
1182 void bpf_prog_destroy(struct bpf_prog *fp)
1183 {
1184 __bpf_prog_release(fp);
1185 }
1186 EXPORT_SYMBOL_GPL(bpf_prog_destroy);
1187
1188 static int __sk_attach_prog(struct bpf_prog *prog, struct sock *sk)
1189 {
1190 struct sk_filter *fp, *old_fp;
1191
1192 fp = kmalloc(sizeof(*fp), GFP_KERNEL);
1193 if (!fp)
1194 return -ENOMEM;
1195
1196 fp->prog = prog;
1197
1198 if (!__sk_filter_charge(sk, fp)) {
1199 kfree(fp);
1200 return -ENOMEM;
1201 }
1202 refcount_set(&fp->refcnt, 1);
1203
1204 old_fp = rcu_dereference_protected(sk->sk_filter,
1205 lockdep_sock_is_held(sk));
1206 rcu_assign_pointer(sk->sk_filter, fp);
1207
1208 if (old_fp)
1209 sk_filter_uncharge(sk, old_fp);
1210
1211 return 0;
1212 }
1213
1214 static int __reuseport_attach_prog(struct bpf_prog *prog, struct sock *sk)
1215 {
1216 struct bpf_prog *old_prog;
1217 int err;
1218
1219 if (bpf_prog_size(prog->len) > sysctl_optmem_max)
1220 return -ENOMEM;
1221
1222 if (sk_unhashed(sk) && sk->sk_reuseport) {
1223 err = reuseport_alloc(sk);
1224 if (err)
1225 return err;
1226 } else if (!rcu_access_pointer(sk->sk_reuseport_cb)) {
1227 /* The socket wasn't bound with SO_REUSEPORT */
1228 return -EINVAL;
1229 }
1230
1231 old_prog = reuseport_attach_prog(sk, prog);
1232 if (old_prog)
1233 bpf_prog_destroy(old_prog);
1234
1235 return 0;
1236 }
1237
1238 static
1239 struct bpf_prog *__get_filter(struct sock_fprog *fprog, struct sock *sk)
1240 {
1241 unsigned int fsize = bpf_classic_proglen(fprog);
1242 struct bpf_prog *prog;
1243 int err;
1244
1245 if (sock_flag(sk, SOCK_FILTER_LOCKED))
1246 return ERR_PTR(-EPERM);
1247
1248 /* Make sure new filter is there and in the right amounts. */
1249 if (!bpf_check_basics_ok(fprog->filter, fprog->len))
1250 return ERR_PTR(-EINVAL);
1251
1252 prog = bpf_prog_alloc(bpf_prog_size(fprog->len), 0);
1253 if (!prog)
1254 return ERR_PTR(-ENOMEM);
1255
1256 if (copy_from_user(prog->insns, fprog->filter, fsize)) {
1257 __bpf_prog_free(prog);
1258 return ERR_PTR(-EFAULT);
1259 }
1260
1261 prog->len = fprog->len;
1262
1263 err = bpf_prog_store_orig_filter(prog, fprog);
1264 if (err) {
1265 __bpf_prog_free(prog);
1266 return ERR_PTR(-ENOMEM);
1267 }
1268
1269 /* bpf_prepare_filter() already takes care of freeing
1270 * memory in case something goes wrong.
1271 */
1272 return bpf_prepare_filter(prog, NULL);
1273 }
1274
1275 /**
1276 * sk_attach_filter - attach a socket filter
1277 * @fprog: the filter program
1278 * @sk: the socket to use
1279 *
1280 * Attach the user's filter code. We first run some sanity checks on
1281 * it to make sure it does not explode on us later. If an error
1282 * occurs or there is insufficient memory for the filter a negative
1283 * errno code is returned. On success the return is zero.
1284 */
1285 int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk)
1286 {
1287 struct bpf_prog *prog = __get_filter(fprog, sk);
1288 int err;
1289
1290 if (IS_ERR(prog))
1291 return PTR_ERR(prog);
1292
1293 err = __sk_attach_prog(prog, sk);
1294 if (err < 0) {
1295 __bpf_prog_release(prog);
1296 return err;
1297 }
1298
1299 return 0;
1300 }
1301 EXPORT_SYMBOL_GPL(sk_attach_filter);
1302
1303 int sk_reuseport_attach_filter(struct sock_fprog *fprog, struct sock *sk)
1304 {
1305 struct bpf_prog *prog = __get_filter(fprog, sk);
1306 int err;
1307
1308 if (IS_ERR(prog))
1309 return PTR_ERR(prog);
1310
1311 err = __reuseport_attach_prog(prog, sk);
1312 if (err < 0) {
1313 __bpf_prog_release(prog);
1314 return err;
1315 }
1316
1317 return 0;
1318 }
1319
1320 static struct bpf_prog *__get_bpf(u32 ufd, struct sock *sk)
1321 {
1322 if (sock_flag(sk, SOCK_FILTER_LOCKED))
1323 return ERR_PTR(-EPERM);
1324
1325 return bpf_prog_get_type(ufd, BPF_PROG_TYPE_SOCKET_FILTER);
1326 }
1327
1328 int sk_attach_bpf(u32 ufd, struct sock *sk)
1329 {
1330 struct bpf_prog *prog = __get_bpf(ufd, sk);
1331 int err;
1332
1333 if (IS_ERR(prog))
1334 return PTR_ERR(prog);
1335
1336 err = __sk_attach_prog(prog, sk);
1337 if (err < 0) {
1338 bpf_prog_put(prog);
1339 return err;
1340 }
1341
1342 return 0;
1343 }
1344
1345 int sk_reuseport_attach_bpf(u32 ufd, struct sock *sk)
1346 {
1347 struct bpf_prog *prog = __get_bpf(ufd, sk);
1348 int err;
1349
1350 if (IS_ERR(prog))
1351 return PTR_ERR(prog);
1352
1353 err = __reuseport_attach_prog(prog, sk);
1354 if (err < 0) {
1355 bpf_prog_put(prog);
1356 return err;
1357 }
1358
1359 return 0;
1360 }
1361
1362 struct bpf_scratchpad {
1363 union {
1364 __be32 diff[MAX_BPF_STACK / sizeof(__be32)];
1365 u8 buff[MAX_BPF_STACK];
1366 };
1367 };
1368
1369 static DEFINE_PER_CPU(struct bpf_scratchpad, bpf_sp);
1370
1371 static inline int __bpf_try_make_writable(struct sk_buff *skb,
1372 unsigned int write_len)
1373 {
1374 return skb_ensure_writable(skb, write_len);
1375 }
1376
1377 static inline int bpf_try_make_writable(struct sk_buff *skb,
1378 unsigned int write_len)
1379 {
1380 int err = __bpf_try_make_writable(skb, write_len);
1381
1382 bpf_compute_data_end(skb);
1383 return err;
1384 }
1385
1386 static int bpf_try_make_head_writable(struct sk_buff *skb)
1387 {
1388 return bpf_try_make_writable(skb, skb_headlen(skb));
1389 }
1390
1391 static inline void bpf_push_mac_rcsum(struct sk_buff *skb)
1392 {
1393 if (skb_at_tc_ingress(skb))
1394 skb_postpush_rcsum(skb, skb_mac_header(skb), skb->mac_len);
1395 }
1396
1397 static inline void bpf_pull_mac_rcsum(struct sk_buff *skb)
1398 {
1399 if (skb_at_tc_ingress(skb))
1400 skb_postpull_rcsum(skb, skb_mac_header(skb), skb->mac_len);
1401 }
1402
1403 BPF_CALL_5(bpf_skb_store_bytes, struct sk_buff *, skb, u32, offset,
1404 const void *, from, u32, len, u64, flags)
1405 {
1406 void *ptr;
1407
1408 if (unlikely(flags & ~(BPF_F_RECOMPUTE_CSUM | BPF_F_INVALIDATE_HASH)))
1409 return -EINVAL;
1410 if (unlikely(offset > 0xffff))
1411 return -EFAULT;
1412 if (unlikely(bpf_try_make_writable(skb, offset + len)))
1413 return -EFAULT;
1414
1415 ptr = skb->data + offset;
1416 if (flags & BPF_F_RECOMPUTE_CSUM)
1417 __skb_postpull_rcsum(skb, ptr, len, offset);
1418
1419 memcpy(ptr, from, len);
1420
1421 if (flags & BPF_F_RECOMPUTE_CSUM)
1422 __skb_postpush_rcsum(skb, ptr, len, offset);
1423 if (flags & BPF_F_INVALIDATE_HASH)
1424 skb_clear_hash(skb);
1425
1426 return 0;
1427 }
1428
1429 static const struct bpf_func_proto bpf_skb_store_bytes_proto = {
1430 .func = bpf_skb_store_bytes,
1431 .gpl_only = false,
1432 .ret_type = RET_INTEGER,
1433 .arg1_type = ARG_PTR_TO_CTX,
1434 .arg2_type = ARG_ANYTHING,
1435 .arg3_type = ARG_PTR_TO_MEM,
1436 .arg4_type = ARG_CONST_SIZE,
1437 .arg5_type = ARG_ANYTHING,
1438 };
1439
1440 BPF_CALL_4(bpf_skb_load_bytes, const struct sk_buff *, skb, u32, offset,
1441 void *, to, u32, len)
1442 {
1443 void *ptr;
1444
1445 if (unlikely(offset > 0xffff))
1446 goto err_clear;
1447
1448 ptr = skb_header_pointer(skb, offset, len, to);
1449 if (unlikely(!ptr))
1450 goto err_clear;
1451 if (ptr != to)
1452 memcpy(to, ptr, len);
1453
1454 return 0;
1455 err_clear:
1456 memset(to, 0, len);
1457 return -EFAULT;
1458 }
1459
1460 static const struct bpf_func_proto bpf_skb_load_bytes_proto = {
1461 .func = bpf_skb_load_bytes,
1462 .gpl_only = false,
1463 .ret_type = RET_INTEGER,
1464 .arg1_type = ARG_PTR_TO_CTX,
1465 .arg2_type = ARG_ANYTHING,
1466 .arg3_type = ARG_PTR_TO_UNINIT_MEM,
1467 .arg4_type = ARG_CONST_SIZE,
1468 };
1469
1470 BPF_CALL_2(bpf_skb_pull_data, struct sk_buff *, skb, u32, len)
1471 {
1472 /* Idea is the following: should the needed direct read/write
1473 * test fail during runtime, we can pull in more data and redo
1474 * again, since implicitly, we invalidate previous checks here.
1475 *
1476 * Or, since we know how much we need to make read/writeable,
1477 * this can be done once at the program beginning for direct
1478 * access case. By this we overcome limitations of only current
1479 * headroom being accessible.
1480 */
1481 return bpf_try_make_writable(skb, len ? : skb_headlen(skb));
1482 }
1483
1484 static const struct bpf_func_proto bpf_skb_pull_data_proto = {
1485 .func = bpf_skb_pull_data,
1486 .gpl_only = false,
1487 .ret_type = RET_INTEGER,
1488 .arg1_type = ARG_PTR_TO_CTX,
1489 .arg2_type = ARG_ANYTHING,
1490 };
1491
1492 BPF_CALL_5(bpf_l3_csum_replace, struct sk_buff *, skb, u32, offset,
1493 u64, from, u64, to, u64, flags)
1494 {
1495 __sum16 *ptr;
1496
1497 if (unlikely(flags & ~(BPF_F_HDR_FIELD_MASK)))
1498 return -EINVAL;
1499 if (unlikely(offset > 0xffff || offset & 1))
1500 return -EFAULT;
1501 if (unlikely(bpf_try_make_writable(skb, offset + sizeof(*ptr))))
1502 return -EFAULT;
1503
1504 ptr = (__sum16 *)(skb->data + offset);
1505 switch (flags & BPF_F_HDR_FIELD_MASK) {
1506 case 0:
1507 if (unlikely(from != 0))
1508 return -EINVAL;
1509
1510 csum_replace_by_diff(ptr, to);
1511 break;
1512 case 2:
1513 csum_replace2(ptr, from, to);
1514 break;
1515 case 4:
1516 csum_replace4(ptr, from, to);
1517 break;
1518 default:
1519 return -EINVAL;
1520 }
1521
1522 return 0;
1523 }
1524
1525 static const struct bpf_func_proto bpf_l3_csum_replace_proto = {
1526 .func = bpf_l3_csum_replace,
1527 .gpl_only = false,
1528 .ret_type = RET_INTEGER,
1529 .arg1_type = ARG_PTR_TO_CTX,
1530 .arg2_type = ARG_ANYTHING,
1531 .arg3_type = ARG_ANYTHING,
1532 .arg4_type = ARG_ANYTHING,
1533 .arg5_type = ARG_ANYTHING,
1534 };
1535
1536 BPF_CALL_5(bpf_l4_csum_replace, struct sk_buff *, skb, u32, offset,
1537 u64, from, u64, to, u64, flags)
1538 {
1539 bool is_pseudo = flags & BPF_F_PSEUDO_HDR;
1540 bool is_mmzero = flags & BPF_F_MARK_MANGLED_0;
1541 bool do_mforce = flags & BPF_F_MARK_ENFORCE;
1542 __sum16 *ptr;
1543
1544 if (unlikely(flags & ~(BPF_F_MARK_MANGLED_0 | BPF_F_MARK_ENFORCE |
1545 BPF_F_PSEUDO_HDR | BPF_F_HDR_FIELD_MASK)))
1546 return -EINVAL;
1547 if (unlikely(offset > 0xffff || offset & 1))
1548 return -EFAULT;
1549 if (unlikely(bpf_try_make_writable(skb, offset + sizeof(*ptr))))
1550 return -EFAULT;
1551
1552 ptr = (__sum16 *)(skb->data + offset);
1553 if (is_mmzero && !do_mforce && !*ptr)
1554 return 0;
1555
1556 switch (flags & BPF_F_HDR_FIELD_MASK) {
1557 case 0:
1558 if (unlikely(from != 0))
1559 return -EINVAL;
1560
1561 inet_proto_csum_replace_by_diff(ptr, skb, to, is_pseudo);
1562 break;
1563 case 2:
1564 inet_proto_csum_replace2(ptr, skb, from, to, is_pseudo);
1565 break;
1566 case 4:
1567 inet_proto_csum_replace4(ptr, skb, from, to, is_pseudo);
1568 break;
1569 default:
1570 return -EINVAL;
1571 }
1572
1573 if (is_mmzero && !*ptr)
1574 *ptr = CSUM_MANGLED_0;
1575 return 0;
1576 }
1577
1578 static const struct bpf_func_proto bpf_l4_csum_replace_proto = {
1579 .func = bpf_l4_csum_replace,
1580 .gpl_only = false,
1581 .ret_type = RET_INTEGER,
1582 .arg1_type = ARG_PTR_TO_CTX,
1583 .arg2_type = ARG_ANYTHING,
1584 .arg3_type = ARG_ANYTHING,
1585 .arg4_type = ARG_ANYTHING,
1586 .arg5_type = ARG_ANYTHING,
1587 };
1588
1589 BPF_CALL_5(bpf_csum_diff, __be32 *, from, u32, from_size,
1590 __be32 *, to, u32, to_size, __wsum, seed)
1591 {
1592 struct bpf_scratchpad *sp = this_cpu_ptr(&bpf_sp);
1593 u32 diff_size = from_size + to_size;
1594 int i, j = 0;
1595
1596 /* This is quite flexible, some examples:
1597 *
1598 * from_size == 0, to_size > 0, seed := csum --> pushing data
1599 * from_size > 0, to_size == 0, seed := csum --> pulling data
1600 * from_size > 0, to_size > 0, seed := 0 --> diffing data
1601 *
1602 * Even for diffing, from_size and to_size don't need to be equal.
1603 */
1604 if (unlikely(((from_size | to_size) & (sizeof(__be32) - 1)) ||
1605 diff_size > sizeof(sp->diff)))
1606 return -EINVAL;
1607
1608 for (i = 0; i < from_size / sizeof(__be32); i++, j++)
1609 sp->diff[j] = ~from[i];
1610 for (i = 0; i < to_size / sizeof(__be32); i++, j++)
1611 sp->diff[j] = to[i];
1612
1613 return csum_partial(sp->diff, diff_size, seed);
1614 }
1615
1616 static const struct bpf_func_proto bpf_csum_diff_proto = {
1617 .func = bpf_csum_diff,
1618 .gpl_only = false,
1619 .pkt_access = true,
1620 .ret_type = RET_INTEGER,
1621 .arg1_type = ARG_PTR_TO_MEM,
1622 .arg2_type = ARG_CONST_SIZE_OR_ZERO,
1623 .arg3_type = ARG_PTR_TO_MEM,
1624 .arg4_type = ARG_CONST_SIZE_OR_ZERO,
1625 .arg5_type = ARG_ANYTHING,
1626 };
1627
1628 BPF_CALL_2(bpf_csum_update, struct sk_buff *, skb, __wsum, csum)
1629 {
1630 /* The interface is to be used in combination with bpf_csum_diff()
1631 * for direct packet writes. csum rotation for alignment as well
1632 * as emulating csum_sub() can be done from the eBPF program.
1633 */
1634 if (skb->ip_summed == CHECKSUM_COMPLETE)
1635 return (skb->csum = csum_add(skb->csum, csum));
1636
1637 return -ENOTSUPP;
1638 }
1639
1640 static const struct bpf_func_proto bpf_csum_update_proto = {
1641 .func = bpf_csum_update,
1642 .gpl_only = false,
1643 .ret_type = RET_INTEGER,
1644 .arg1_type = ARG_PTR_TO_CTX,
1645 .arg2_type = ARG_ANYTHING,
1646 };
1647
1648 static inline int __bpf_rx_skb(struct net_device *dev, struct sk_buff *skb)
1649 {
1650 return dev_forward_skb(dev, skb);
1651 }
1652
1653 static inline int __bpf_rx_skb_no_mac(struct net_device *dev,
1654 struct sk_buff *skb)
1655 {
1656 int ret = ____dev_forward_skb(dev, skb);
1657
1658 if (likely(!ret)) {
1659 skb->dev = dev;
1660 ret = netif_rx(skb);
1661 }
1662
1663 return ret;
1664 }
1665
1666 static inline int __bpf_tx_skb(struct net_device *dev, struct sk_buff *skb)
1667 {
1668 int ret;
1669
1670 if (unlikely(__this_cpu_read(xmit_recursion) > XMIT_RECURSION_LIMIT)) {
1671 net_crit_ratelimited("bpf: recursion limit reached on datapath, buggy bpf program?\n");
1672 kfree_skb(skb);
1673 return -ENETDOWN;
1674 }
1675
1676 skb->dev = dev;
1677
1678 __this_cpu_inc(xmit_recursion);
1679 ret = dev_queue_xmit(skb);
1680 __this_cpu_dec(xmit_recursion);
1681
1682 return ret;
1683 }
1684
1685 static int __bpf_redirect_no_mac(struct sk_buff *skb, struct net_device *dev,
1686 u32 flags)
1687 {
1688 /* skb->mac_len is not set on normal egress */
1689 unsigned int mlen = skb->network_header - skb->mac_header;
1690
1691 __skb_pull(skb, mlen);
1692
1693 /* At ingress, the mac header has already been pulled once.
1694 * At egress, skb_pospull_rcsum has to be done in case that
1695 * the skb is originated from ingress (i.e. a forwarded skb)
1696 * to ensure that rcsum starts at net header.
1697 */
1698 if (!skb_at_tc_ingress(skb))
1699 skb_postpull_rcsum(skb, skb_mac_header(skb), mlen);
1700 skb_pop_mac_header(skb);
1701 skb_reset_mac_len(skb);
1702 return flags & BPF_F_INGRESS ?
1703 __bpf_rx_skb_no_mac(dev, skb) : __bpf_tx_skb(dev, skb);
1704 }
1705
1706 static int __bpf_redirect_common(struct sk_buff *skb, struct net_device *dev,
1707 u32 flags)
1708 {
1709 /* Verify that a link layer header is carried */
1710 if (unlikely(skb->mac_header >= skb->network_header)) {
1711 kfree_skb(skb);
1712 return -ERANGE;
1713 }
1714
1715 bpf_push_mac_rcsum(skb);
1716 return flags & BPF_F_INGRESS ?
1717 __bpf_rx_skb(dev, skb) : __bpf_tx_skb(dev, skb);
1718 }
1719
1720 static int __bpf_redirect(struct sk_buff *skb, struct net_device *dev,
1721 u32 flags)
1722 {
1723 if (dev_is_mac_header_xmit(dev))
1724 return __bpf_redirect_common(skb, dev, flags);
1725 else
1726 return __bpf_redirect_no_mac(skb, dev, flags);
1727 }
1728
1729 BPF_CALL_3(bpf_clone_redirect, struct sk_buff *, skb, u32, ifindex, u64, flags)
1730 {
1731 struct net_device *dev;
1732 struct sk_buff *clone;
1733 int ret;
1734
1735 if (unlikely(flags & ~(BPF_F_INGRESS)))
1736 return -EINVAL;
1737
1738 dev = dev_get_by_index_rcu(dev_net(skb->dev), ifindex);
1739 if (unlikely(!dev))
1740 return -EINVAL;
1741
1742 clone = skb_clone(skb, GFP_ATOMIC);
1743 if (unlikely(!clone))
1744 return -ENOMEM;
1745
1746 /* For direct write, we need to keep the invariant that the skbs
1747 * we're dealing with need to be uncloned. Should uncloning fail
1748 * here, we need to free the just generated clone to unclone once
1749 * again.
1750 */
1751 ret = bpf_try_make_head_writable(skb);
1752 if (unlikely(ret)) {
1753 kfree_skb(clone);
1754 return -ENOMEM;
1755 }
1756
1757 return __bpf_redirect(clone, dev, flags);
1758 }
1759
1760 static const struct bpf_func_proto bpf_clone_redirect_proto = {
1761 .func = bpf_clone_redirect,
1762 .gpl_only = false,
1763 .ret_type = RET_INTEGER,
1764 .arg1_type = ARG_PTR_TO_CTX,
1765 .arg2_type = ARG_ANYTHING,
1766 .arg3_type = ARG_ANYTHING,
1767 };
1768
1769 struct redirect_info {
1770 u32 ifindex;
1771 u32 flags;
1772 };
1773
1774 static DEFINE_PER_CPU(struct redirect_info, redirect_info);
1775
1776 BPF_CALL_2(bpf_redirect, u32, ifindex, u64, flags)
1777 {
1778 struct redirect_info *ri = this_cpu_ptr(&redirect_info);
1779
1780 if (unlikely(flags & ~(BPF_F_INGRESS)))
1781 return TC_ACT_SHOT;
1782
1783 ri->ifindex = ifindex;
1784 ri->flags = flags;
1785
1786 return TC_ACT_REDIRECT;
1787 }
1788
1789 int skb_do_redirect(struct sk_buff *skb)
1790 {
1791 struct redirect_info *ri = this_cpu_ptr(&redirect_info);
1792 struct net_device *dev;
1793
1794 dev = dev_get_by_index_rcu(dev_net(skb->dev), ri->ifindex);
1795 ri->ifindex = 0;
1796 if (unlikely(!dev)) {
1797 kfree_skb(skb);
1798 return -EINVAL;
1799 }
1800
1801 return __bpf_redirect(skb, dev, ri->flags);
1802 }
1803
1804 static const struct bpf_func_proto bpf_redirect_proto = {
1805 .func = bpf_redirect,
1806 .gpl_only = false,
1807 .ret_type = RET_INTEGER,
1808 .arg1_type = ARG_ANYTHING,
1809 .arg2_type = ARG_ANYTHING,
1810 };
1811
1812 BPF_CALL_1(bpf_get_cgroup_classid, const struct sk_buff *, skb)
1813 {
1814 return task_get_classid(skb);
1815 }
1816
1817 static const struct bpf_func_proto bpf_get_cgroup_classid_proto = {
1818 .func = bpf_get_cgroup_classid,
1819 .gpl_only = false,
1820 .ret_type = RET_INTEGER,
1821 .arg1_type = ARG_PTR_TO_CTX,
1822 };
1823
1824 BPF_CALL_1(bpf_get_route_realm, const struct sk_buff *, skb)
1825 {
1826 return dst_tclassid(skb);
1827 }
1828
1829 static const struct bpf_func_proto bpf_get_route_realm_proto = {
1830 .func = bpf_get_route_realm,
1831 .gpl_only = false,
1832 .ret_type = RET_INTEGER,
1833 .arg1_type = ARG_PTR_TO_CTX,
1834 };
1835
1836 BPF_CALL_1(bpf_get_hash_recalc, struct sk_buff *, skb)
1837 {
1838 /* If skb_clear_hash() was called due to mangling, we can
1839 * trigger SW recalculation here. Later access to hash
1840 * can then use the inline skb->hash via context directly
1841 * instead of calling this helper again.
1842 */
1843 return skb_get_hash(skb);
1844 }
1845
1846 static const struct bpf_func_proto bpf_get_hash_recalc_proto = {
1847 .func = bpf_get_hash_recalc,
1848 .gpl_only = false,
1849 .ret_type = RET_INTEGER,
1850 .arg1_type = ARG_PTR_TO_CTX,
1851 };
1852
1853 BPF_CALL_1(bpf_set_hash_invalid, struct sk_buff *, skb)
1854 {
1855 /* After all direct packet write, this can be used once for
1856 * triggering a lazy recalc on next skb_get_hash() invocation.
1857 */
1858 skb_clear_hash(skb);
1859 return 0;
1860 }
1861
1862 static const struct bpf_func_proto bpf_set_hash_invalid_proto = {
1863 .func = bpf_set_hash_invalid,
1864 .gpl_only = false,
1865 .ret_type = RET_INTEGER,
1866 .arg1_type = ARG_PTR_TO_CTX,
1867 };
1868
1869 BPF_CALL_3(bpf_skb_vlan_push, struct sk_buff *, skb, __be16, vlan_proto,
1870 u16, vlan_tci)
1871 {
1872 int ret;
1873
1874 if (unlikely(vlan_proto != htons(ETH_P_8021Q) &&
1875 vlan_proto != htons(ETH_P_8021AD)))
1876 vlan_proto = htons(ETH_P_8021Q);
1877
1878 bpf_push_mac_rcsum(skb);
1879 ret = skb_vlan_push(skb, vlan_proto, vlan_tci);
1880 bpf_pull_mac_rcsum(skb);
1881
1882 bpf_compute_data_end(skb);
1883 return ret;
1884 }
1885
1886 const struct bpf_func_proto bpf_skb_vlan_push_proto = {
1887 .func = bpf_skb_vlan_push,
1888 .gpl_only = false,
1889 .ret_type = RET_INTEGER,
1890 .arg1_type = ARG_PTR_TO_CTX,
1891 .arg2_type = ARG_ANYTHING,
1892 .arg3_type = ARG_ANYTHING,
1893 };
1894 EXPORT_SYMBOL_GPL(bpf_skb_vlan_push_proto);
1895
1896 BPF_CALL_1(bpf_skb_vlan_pop, struct sk_buff *, skb)
1897 {
1898 int ret;
1899
1900 bpf_push_mac_rcsum(skb);
1901 ret = skb_vlan_pop(skb);
1902 bpf_pull_mac_rcsum(skb);
1903
1904 bpf_compute_data_end(skb);
1905 return ret;
1906 }
1907
1908 const struct bpf_func_proto bpf_skb_vlan_pop_proto = {
1909 .func = bpf_skb_vlan_pop,
1910 .gpl_only = false,
1911 .ret_type = RET_INTEGER,
1912 .arg1_type = ARG_PTR_TO_CTX,
1913 };
1914 EXPORT_SYMBOL_GPL(bpf_skb_vlan_pop_proto);
1915
1916 static int bpf_skb_generic_push(struct sk_buff *skb, u32 off, u32 len)
1917 {
1918 /* Caller already did skb_cow() with len as headroom,
1919 * so no need to do it here.
1920 */
1921 skb_push(skb, len);
1922 memmove(skb->data, skb->data + len, off);
1923 memset(skb->data + off, 0, len);
1924
1925 /* No skb_postpush_rcsum(skb, skb->data + off, len)
1926 * needed here as it does not change the skb->csum
1927 * result for checksum complete when summing over
1928 * zeroed blocks.
1929 */
1930 return 0;
1931 }
1932
1933 static int bpf_skb_generic_pop(struct sk_buff *skb, u32 off, u32 len)
1934 {
1935 /* skb_ensure_writable() is not needed here, as we're
1936 * already working on an uncloned skb.
1937 */
1938 if (unlikely(!pskb_may_pull(skb, off + len)))
1939 return -ENOMEM;
1940
1941 skb_postpull_rcsum(skb, skb->data + off, len);
1942 memmove(skb->data + len, skb->data, off);
1943 __skb_pull(skb, len);
1944
1945 return 0;
1946 }
1947
1948 static int bpf_skb_net_hdr_push(struct sk_buff *skb, u32 off, u32 len)
1949 {
1950 bool trans_same = skb->transport_header == skb->network_header;
1951 int ret;
1952
1953 /* There's no need for __skb_push()/__skb_pull() pair to
1954 * get to the start of the mac header as we're guaranteed
1955 * to always start from here under eBPF.
1956 */
1957 ret = bpf_skb_generic_push(skb, off, len);
1958 if (likely(!ret)) {
1959 skb->mac_header -= len;
1960 skb->network_header -= len;
1961 if (trans_same)
1962 skb->transport_header = skb->network_header;
1963 }
1964
1965 return ret;
1966 }
1967
1968 static int bpf_skb_net_hdr_pop(struct sk_buff *skb, u32 off, u32 len)
1969 {
1970 bool trans_same = skb->transport_header == skb->network_header;
1971 int ret;
1972
1973 /* Same here, __skb_push()/__skb_pull() pair not needed. */
1974 ret = bpf_skb_generic_pop(skb, off, len);
1975 if (likely(!ret)) {
1976 skb->mac_header += len;
1977 skb->network_header += len;
1978 if (trans_same)
1979 skb->transport_header = skb->network_header;
1980 }
1981
1982 return ret;
1983 }
1984
1985 static int bpf_skb_proto_4_to_6(struct sk_buff *skb)
1986 {
1987 const u32 len_diff = sizeof(struct ipv6hdr) - sizeof(struct iphdr);
1988 u32 off = skb->network_header - skb->mac_header;
1989 int ret;
1990
1991 ret = skb_cow(skb, len_diff);
1992 if (unlikely(ret < 0))
1993 return ret;
1994
1995 ret = bpf_skb_net_hdr_push(skb, off, len_diff);
1996 if (unlikely(ret < 0))
1997 return ret;
1998
1999 if (skb_is_gso(skb)) {
2000 /* SKB_GSO_UDP stays as is. SKB_GSO_TCPV4 needs to
2001 * be changed into SKB_GSO_TCPV6.
2002 */
2003 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4) {
2004 skb_shinfo(skb)->gso_type &= ~SKB_GSO_TCPV4;
2005 skb_shinfo(skb)->gso_type |= SKB_GSO_TCPV6;
2006 }
2007
2008 /* Due to IPv6 header, MSS needs to be downgraded. */
2009 skb_shinfo(skb)->gso_size -= len_diff;
2010 /* Header must be checked, and gso_segs recomputed. */
2011 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
2012 skb_shinfo(skb)->gso_segs = 0;
2013 }
2014
2015 skb->protocol = htons(ETH_P_IPV6);
2016 skb_clear_hash(skb);
2017
2018 return 0;
2019 }
2020
2021 static int bpf_skb_proto_6_to_4(struct sk_buff *skb)
2022 {
2023 const u32 len_diff = sizeof(struct ipv6hdr) - sizeof(struct iphdr);
2024 u32 off = skb->network_header - skb->mac_header;
2025 int ret;
2026
2027 ret = skb_unclone(skb, GFP_ATOMIC);
2028 if (unlikely(ret < 0))
2029 return ret;
2030
2031 ret = bpf_skb_net_hdr_pop(skb, off, len_diff);
2032 if (unlikely(ret < 0))
2033 return ret;
2034
2035 if (skb_is_gso(skb)) {
2036 /* SKB_GSO_UDP stays as is. SKB_GSO_TCPV6 needs to
2037 * be changed into SKB_GSO_TCPV4.
2038 */
2039 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6) {
2040 skb_shinfo(skb)->gso_type &= ~SKB_GSO_TCPV6;
2041 skb_shinfo(skb)->gso_type |= SKB_GSO_TCPV4;
2042 }
2043
2044 /* Due to IPv4 header, MSS can be upgraded. */
2045 skb_shinfo(skb)->gso_size += len_diff;
2046 /* Header must be checked, and gso_segs recomputed. */
2047 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
2048 skb_shinfo(skb)->gso_segs = 0;
2049 }
2050
2051 skb->protocol = htons(ETH_P_IP);
2052 skb_clear_hash(skb);
2053
2054 return 0;
2055 }
2056
2057 static int bpf_skb_proto_xlat(struct sk_buff *skb, __be16 to_proto)
2058 {
2059 __be16 from_proto = skb->protocol;
2060
2061 if (from_proto == htons(ETH_P_IP) &&
2062 to_proto == htons(ETH_P_IPV6))
2063 return bpf_skb_proto_4_to_6(skb);
2064
2065 if (from_proto == htons(ETH_P_IPV6) &&
2066 to_proto == htons(ETH_P_IP))
2067 return bpf_skb_proto_6_to_4(skb);
2068
2069 return -ENOTSUPP;
2070 }
2071
2072 BPF_CALL_3(bpf_skb_change_proto, struct sk_buff *, skb, __be16, proto,
2073 u64, flags)
2074 {
2075 int ret;
2076
2077 if (unlikely(flags))
2078 return -EINVAL;
2079
2080 /* General idea is that this helper does the basic groundwork
2081 * needed for changing the protocol, and eBPF program fills the
2082 * rest through bpf_skb_store_bytes(), bpf_lX_csum_replace()
2083 * and other helpers, rather than passing a raw buffer here.
2084 *
2085 * The rationale is to keep this minimal and without a need to
2086 * deal with raw packet data. F.e. even if we would pass buffers
2087 * here, the program still needs to call the bpf_lX_csum_replace()
2088 * helpers anyway. Plus, this way we keep also separation of
2089 * concerns, since f.e. bpf_skb_store_bytes() should only take
2090 * care of stores.
2091 *
2092 * Currently, additional options and extension header space are
2093 * not supported, but flags register is reserved so we can adapt
2094 * that. For offloads, we mark packet as dodgy, so that headers
2095 * need to be verified first.
2096 */
2097 ret = bpf_skb_proto_xlat(skb, proto);
2098 bpf_compute_data_end(skb);
2099 return ret;
2100 }
2101
2102 static const struct bpf_func_proto bpf_skb_change_proto_proto = {
2103 .func = bpf_skb_change_proto,
2104 .gpl_only = false,
2105 .ret_type = RET_INTEGER,
2106 .arg1_type = ARG_PTR_TO_CTX,
2107 .arg2_type = ARG_ANYTHING,
2108 .arg3_type = ARG_ANYTHING,
2109 };
2110
2111 BPF_CALL_2(bpf_skb_change_type, struct sk_buff *, skb, u32, pkt_type)
2112 {
2113 /* We only allow a restricted subset to be changed for now. */
2114 if (unlikely(!skb_pkt_type_ok(skb->pkt_type) ||
2115 !skb_pkt_type_ok(pkt_type)))
2116 return -EINVAL;
2117
2118 skb->pkt_type = pkt_type;
2119 return 0;
2120 }
2121
2122 static const struct bpf_func_proto bpf_skb_change_type_proto = {
2123 .func = bpf_skb_change_type,
2124 .gpl_only = false,
2125 .ret_type = RET_INTEGER,
2126 .arg1_type = ARG_PTR_TO_CTX,
2127 .arg2_type = ARG_ANYTHING,
2128 };
2129
2130 static u32 __bpf_skb_min_len(const struct sk_buff *skb)
2131 {
2132 u32 min_len = skb_network_offset(skb);
2133
2134 if (skb_transport_header_was_set(skb))
2135 min_len = skb_transport_offset(skb);
2136 if (skb->ip_summed == CHECKSUM_PARTIAL)
2137 min_len = skb_checksum_start_offset(skb) +
2138 skb->csum_offset + sizeof(__sum16);
2139 return min_len;
2140 }
2141
2142 static u32 __bpf_skb_max_len(const struct sk_buff *skb)
2143 {
2144 return skb->dev->mtu + skb->dev->hard_header_len;
2145 }
2146
2147 static int bpf_skb_grow_rcsum(struct sk_buff *skb, unsigned int new_len)
2148 {
2149 unsigned int old_len = skb->len;
2150 int ret;
2151
2152 ret = __skb_grow_rcsum(skb, new_len);
2153 if (!ret)
2154 memset(skb->data + old_len, 0, new_len - old_len);
2155 return ret;
2156 }
2157
2158 static int bpf_skb_trim_rcsum(struct sk_buff *skb, unsigned int new_len)
2159 {
2160 return __skb_trim_rcsum(skb, new_len);
2161 }
2162
2163 BPF_CALL_3(bpf_skb_change_tail, struct sk_buff *, skb, u32, new_len,
2164 u64, flags)
2165 {
2166 u32 max_len = __bpf_skb_max_len(skb);
2167 u32 min_len = __bpf_skb_min_len(skb);
2168 int ret;
2169
2170 if (unlikely(flags || new_len > max_len || new_len < min_len))
2171 return -EINVAL;
2172 if (skb->encapsulation)
2173 return -ENOTSUPP;
2174
2175 /* The basic idea of this helper is that it's performing the
2176 * needed work to either grow or trim an skb, and eBPF program
2177 * rewrites the rest via helpers like bpf_skb_store_bytes(),
2178 * bpf_lX_csum_replace() and others rather than passing a raw
2179 * buffer here. This one is a slow path helper and intended
2180 * for replies with control messages.
2181 *
2182 * Like in bpf_skb_change_proto(), we want to keep this rather
2183 * minimal and without protocol specifics so that we are able
2184 * to separate concerns as in bpf_skb_store_bytes() should only
2185 * be the one responsible for writing buffers.
2186 *
2187 * It's really expected to be a slow path operation here for
2188 * control message replies, so we're implicitly linearizing,
2189 * uncloning and drop offloads from the skb by this.
2190 */
2191 ret = __bpf_try_make_writable(skb, skb->len);
2192 if (!ret) {
2193 if (new_len > skb->len)
2194 ret = bpf_skb_grow_rcsum(skb, new_len);
2195 else if (new_len < skb->len)
2196 ret = bpf_skb_trim_rcsum(skb, new_len);
2197 if (!ret && skb_is_gso(skb))
2198 skb_gso_reset(skb);
2199 }
2200
2201 bpf_compute_data_end(skb);
2202 return ret;
2203 }
2204
2205 static const struct bpf_func_proto bpf_skb_change_tail_proto = {
2206 .func = bpf_skb_change_tail,
2207 .gpl_only = false,
2208 .ret_type = RET_INTEGER,
2209 .arg1_type = ARG_PTR_TO_CTX,
2210 .arg2_type = ARG_ANYTHING,
2211 .arg3_type = ARG_ANYTHING,
2212 };
2213
2214 BPF_CALL_3(bpf_skb_change_head, struct sk_buff *, skb, u32, head_room,
2215 u64, flags)
2216 {
2217 u32 max_len = __bpf_skb_max_len(skb);
2218 u32 new_len = skb->len + head_room;
2219 int ret;
2220
2221 if (unlikely(flags || (!skb_is_gso(skb) && new_len > max_len) ||
2222 new_len < skb->len))
2223 return -EINVAL;
2224
2225 ret = skb_cow(skb, head_room);
2226 if (likely(!ret)) {
2227 /* Idea for this helper is that we currently only
2228 * allow to expand on mac header. This means that
2229 * skb->protocol network header, etc, stay as is.
2230 * Compared to bpf_skb_change_tail(), we're more
2231 * flexible due to not needing to linearize or
2232 * reset GSO. Intention for this helper is to be
2233 * used by an L3 skb that needs to push mac header
2234 * for redirection into L2 device.
2235 */
2236 __skb_push(skb, head_room);
2237 memset(skb->data, 0, head_room);
2238 skb_reset_mac_header(skb);
2239 }
2240
2241 bpf_compute_data_end(skb);
2242 return 0;
2243 }
2244
2245 static const struct bpf_func_proto bpf_skb_change_head_proto = {
2246 .func = bpf_skb_change_head,
2247 .gpl_only = false,
2248 .ret_type = RET_INTEGER,
2249 .arg1_type = ARG_PTR_TO_CTX,
2250 .arg2_type = ARG_ANYTHING,
2251 .arg3_type = ARG_ANYTHING,
2252 };
2253
2254 BPF_CALL_2(bpf_xdp_adjust_head, struct xdp_buff *, xdp, int, offset)
2255 {
2256 void *data = xdp->data + offset;
2257
2258 if (unlikely(data < xdp->data_hard_start ||
2259 data > xdp->data_end - ETH_HLEN))
2260 return -EINVAL;
2261
2262 xdp->data = data;
2263
2264 return 0;
2265 }
2266
2267 static const struct bpf_func_proto bpf_xdp_adjust_head_proto = {
2268 .func = bpf_xdp_adjust_head,
2269 .gpl_only = false,
2270 .ret_type = RET_INTEGER,
2271 .arg1_type = ARG_PTR_TO_CTX,
2272 .arg2_type = ARG_ANYTHING,
2273 };
2274
2275 bool bpf_helper_changes_pkt_data(void *func)
2276 {
2277 if (func == bpf_skb_vlan_push ||
2278 func == bpf_skb_vlan_pop ||
2279 func == bpf_skb_store_bytes ||
2280 func == bpf_skb_change_proto ||
2281 func == bpf_skb_change_head ||
2282 func == bpf_skb_change_tail ||
2283 func == bpf_skb_pull_data ||
2284 func == bpf_l3_csum_replace ||
2285 func == bpf_l4_csum_replace ||
2286 func == bpf_xdp_adjust_head)
2287 return true;
2288
2289 return false;
2290 }
2291
2292 static unsigned long bpf_skb_copy(void *dst_buff, const void *skb,
2293 unsigned long off, unsigned long len)
2294 {
2295 void *ptr = skb_header_pointer(skb, off, len, dst_buff);
2296
2297 if (unlikely(!ptr))
2298 return len;
2299 if (ptr != dst_buff)
2300 memcpy(dst_buff, ptr, len);
2301
2302 return 0;
2303 }
2304
2305 BPF_CALL_5(bpf_skb_event_output, struct sk_buff *, skb, struct bpf_map *, map,
2306 u64, flags, void *, meta, u64, meta_size)
2307 {
2308 u64 skb_size = (flags & BPF_F_CTXLEN_MASK) >> 32;
2309
2310 if (unlikely(flags & ~(BPF_F_CTXLEN_MASK | BPF_F_INDEX_MASK)))
2311 return -EINVAL;
2312 if (unlikely(skb_size > skb->len))
2313 return -EFAULT;
2314
2315 return bpf_event_output(map, flags, meta, meta_size, skb, skb_size,
2316 bpf_skb_copy);
2317 }
2318
2319 static const struct bpf_func_proto bpf_skb_event_output_proto = {
2320 .func = bpf_skb_event_output,
2321 .gpl_only = true,
2322 .ret_type = RET_INTEGER,
2323 .arg1_type = ARG_PTR_TO_CTX,
2324 .arg2_type = ARG_CONST_MAP_PTR,
2325 .arg3_type = ARG_ANYTHING,
2326 .arg4_type = ARG_PTR_TO_MEM,
2327 .arg5_type = ARG_CONST_SIZE,
2328 };
2329
2330 static unsigned short bpf_tunnel_key_af(u64 flags)
2331 {
2332 return flags & BPF_F_TUNINFO_IPV6 ? AF_INET6 : AF_INET;
2333 }
2334
2335 BPF_CALL_4(bpf_skb_get_tunnel_key, struct sk_buff *, skb, struct bpf_tunnel_key *, to,
2336 u32, size, u64, flags)
2337 {
2338 const struct ip_tunnel_info *info = skb_tunnel_info(skb);
2339 u8 compat[sizeof(struct bpf_tunnel_key)];
2340 void *to_orig = to;
2341 int err;
2342
2343 if (unlikely(!info || (flags & ~(BPF_F_TUNINFO_IPV6)))) {
2344 err = -EINVAL;
2345 goto err_clear;
2346 }
2347 if (ip_tunnel_info_af(info) != bpf_tunnel_key_af(flags)) {
2348 err = -EPROTO;
2349 goto err_clear;
2350 }
2351 if (unlikely(size != sizeof(struct bpf_tunnel_key))) {
2352 err = -EINVAL;
2353 switch (size) {
2354 case offsetof(struct bpf_tunnel_key, tunnel_label):
2355 case offsetof(struct bpf_tunnel_key, tunnel_ext):
2356 goto set_compat;
2357 case offsetof(struct bpf_tunnel_key, remote_ipv6[1]):
2358 /* Fixup deprecated structure layouts here, so we have
2359 * a common path later on.
2360 */
2361 if (ip_tunnel_info_af(info) != AF_INET)
2362 goto err_clear;
2363 set_compat:
2364 to = (struct bpf_tunnel_key *)compat;
2365 break;
2366 default:
2367 goto err_clear;
2368 }
2369 }
2370
2371 to->tunnel_id = be64_to_cpu(info->key.tun_id);
2372 to->tunnel_tos = info->key.tos;
2373 to->tunnel_ttl = info->key.ttl;
2374
2375 if (flags & BPF_F_TUNINFO_IPV6) {
2376 memcpy(to->remote_ipv6, &info->key.u.ipv6.src,
2377 sizeof(to->remote_ipv6));
2378 to->tunnel_label = be32_to_cpu(info->key.label);
2379 } else {
2380 to->remote_ipv4 = be32_to_cpu(info->key.u.ipv4.src);
2381 }
2382
2383 if (unlikely(size != sizeof(struct bpf_tunnel_key)))
2384 memcpy(to_orig, to, size);
2385
2386 return 0;
2387 err_clear:
2388 memset(to_orig, 0, size);
2389 return err;
2390 }
2391
2392 static const struct bpf_func_proto bpf_skb_get_tunnel_key_proto = {
2393 .func = bpf_skb_get_tunnel_key,
2394 .gpl_only = false,
2395 .ret_type = RET_INTEGER,
2396 .arg1_type = ARG_PTR_TO_CTX,
2397 .arg2_type = ARG_PTR_TO_UNINIT_MEM,
2398 .arg3_type = ARG_CONST_SIZE,
2399 .arg4_type = ARG_ANYTHING,
2400 };
2401
2402 BPF_CALL_3(bpf_skb_get_tunnel_opt, struct sk_buff *, skb, u8 *, to, u32, size)
2403 {
2404 const struct ip_tunnel_info *info = skb_tunnel_info(skb);
2405 int err;
2406
2407 if (unlikely(!info ||
2408 !(info->key.tun_flags & TUNNEL_OPTIONS_PRESENT))) {
2409 err = -ENOENT;
2410 goto err_clear;
2411 }
2412 if (unlikely(size < info->options_len)) {
2413 err = -ENOMEM;
2414 goto err_clear;
2415 }
2416
2417 ip_tunnel_info_opts_get(to, info);
2418 if (size > info->options_len)
2419 memset(to + info->options_len, 0, size - info->options_len);
2420
2421 return info->options_len;
2422 err_clear:
2423 memset(to, 0, size);
2424 return err;
2425 }
2426
2427 static const struct bpf_func_proto bpf_skb_get_tunnel_opt_proto = {
2428 .func = bpf_skb_get_tunnel_opt,
2429 .gpl_only = false,
2430 .ret_type = RET_INTEGER,
2431 .arg1_type = ARG_PTR_TO_CTX,
2432 .arg2_type = ARG_PTR_TO_UNINIT_MEM,
2433 .arg3_type = ARG_CONST_SIZE,
2434 };
2435
2436 static struct metadata_dst __percpu *md_dst;
2437
2438 BPF_CALL_4(bpf_skb_set_tunnel_key, struct sk_buff *, skb,
2439 const struct bpf_tunnel_key *, from, u32, size, u64, flags)
2440 {
2441 struct metadata_dst *md = this_cpu_ptr(md_dst);
2442 u8 compat[sizeof(struct bpf_tunnel_key)];
2443 struct ip_tunnel_info *info;
2444
2445 if (unlikely(flags & ~(BPF_F_TUNINFO_IPV6 | BPF_F_ZERO_CSUM_TX |
2446 BPF_F_DONT_FRAGMENT)))
2447 return -EINVAL;
2448 if (unlikely(size != sizeof(struct bpf_tunnel_key))) {
2449 switch (size) {
2450 case offsetof(struct bpf_tunnel_key, tunnel_label):
2451 case offsetof(struct bpf_tunnel_key, tunnel_ext):
2452 case offsetof(struct bpf_tunnel_key, remote_ipv6[1]):
2453 /* Fixup deprecated structure layouts here, so we have
2454 * a common path later on.
2455 */
2456 memcpy(compat, from, size);
2457 memset(compat + size, 0, sizeof(compat) - size);
2458 from = (const struct bpf_tunnel_key *) compat;
2459 break;
2460 default:
2461 return -EINVAL;
2462 }
2463 }
2464 if (unlikely((!(flags & BPF_F_TUNINFO_IPV6) && from->tunnel_label) ||
2465 from->tunnel_ext))
2466 return -EINVAL;
2467
2468 skb_dst_drop(skb);
2469 dst_hold((struct dst_entry *) md);
2470 skb_dst_set(skb, (struct dst_entry *) md);
2471
2472 info = &md->u.tun_info;
2473 info->mode = IP_TUNNEL_INFO_TX;
2474
2475 info->key.tun_flags = TUNNEL_KEY | TUNNEL_CSUM | TUNNEL_NOCACHE;
2476 if (flags & BPF_F_DONT_FRAGMENT)
2477 info->key.tun_flags |= TUNNEL_DONT_FRAGMENT;
2478
2479 info->key.tun_id = cpu_to_be64(from->tunnel_id);
2480 info->key.tos = from->tunnel_tos;
2481 info->key.ttl = from->tunnel_ttl;
2482
2483 if (flags & BPF_F_TUNINFO_IPV6) {
2484 info->mode |= IP_TUNNEL_INFO_IPV6;
2485 memcpy(&info->key.u.ipv6.dst, from->remote_ipv6,
2486 sizeof(from->remote_ipv6));
2487 info->key.label = cpu_to_be32(from->tunnel_label) &
2488 IPV6_FLOWLABEL_MASK;
2489 } else {
2490 info->key.u.ipv4.dst = cpu_to_be32(from->remote_ipv4);
2491 if (flags & BPF_F_ZERO_CSUM_TX)
2492 info->key.tun_flags &= ~TUNNEL_CSUM;
2493 }
2494
2495 return 0;
2496 }
2497
2498 static const struct bpf_func_proto bpf_skb_set_tunnel_key_proto = {
2499 .func = bpf_skb_set_tunnel_key,
2500 .gpl_only = false,
2501 .ret_type = RET_INTEGER,
2502 .arg1_type = ARG_PTR_TO_CTX,
2503 .arg2_type = ARG_PTR_TO_MEM,
2504 .arg3_type = ARG_CONST_SIZE,
2505 .arg4_type = ARG_ANYTHING,
2506 };
2507
2508 BPF_CALL_3(bpf_skb_set_tunnel_opt, struct sk_buff *, skb,
2509 const u8 *, from, u32, size)
2510 {
2511 struct ip_tunnel_info *info = skb_tunnel_info(skb);
2512 const struct metadata_dst *md = this_cpu_ptr(md_dst);
2513
2514 if (unlikely(info != &md->u.tun_info || (size & (sizeof(u32) - 1))))
2515 return -EINVAL;
2516 if (unlikely(size > IP_TUNNEL_OPTS_MAX))
2517 return -ENOMEM;
2518
2519 ip_tunnel_info_opts_set(info, from, size);
2520
2521 return 0;
2522 }
2523
2524 static const struct bpf_func_proto bpf_skb_set_tunnel_opt_proto = {
2525 .func = bpf_skb_set_tunnel_opt,
2526 .gpl_only = false,
2527 .ret_type = RET_INTEGER,
2528 .arg1_type = ARG_PTR_TO_CTX,
2529 .arg2_type = ARG_PTR_TO_MEM,
2530 .arg3_type = ARG_CONST_SIZE,
2531 };
2532
2533 static const struct bpf_func_proto *
2534 bpf_get_skb_set_tunnel_proto(enum bpf_func_id which)
2535 {
2536 if (!md_dst) {
2537 /* Race is not possible, since it's called from verifier
2538 * that is holding verifier mutex.
2539 */
2540 md_dst = metadata_dst_alloc_percpu(IP_TUNNEL_OPTS_MAX,
2541 GFP_KERNEL);
2542 if (!md_dst)
2543 return NULL;
2544 }
2545
2546 switch (which) {
2547 case BPF_FUNC_skb_set_tunnel_key:
2548 return &bpf_skb_set_tunnel_key_proto;
2549 case BPF_FUNC_skb_set_tunnel_opt:
2550 return &bpf_skb_set_tunnel_opt_proto;
2551 default:
2552 return NULL;
2553 }
2554 }
2555
2556 BPF_CALL_3(bpf_skb_under_cgroup, struct sk_buff *, skb, struct bpf_map *, map,
2557 u32, idx)
2558 {
2559 struct bpf_array *array = container_of(map, struct bpf_array, map);
2560 struct cgroup *cgrp;
2561 struct sock *sk;
2562
2563 sk = skb_to_full_sk(skb);
2564 if (!sk || !sk_fullsock(sk))
2565 return -ENOENT;
2566 if (unlikely(idx >= array->map.max_entries))
2567 return -E2BIG;
2568
2569 cgrp = READ_ONCE(array->ptrs[idx]);
2570 if (unlikely(!cgrp))
2571 return -EAGAIN;
2572
2573 return sk_under_cgroup_hierarchy(sk, cgrp);
2574 }
2575
2576 static const struct bpf_func_proto bpf_skb_under_cgroup_proto = {
2577 .func = bpf_skb_under_cgroup,
2578 .gpl_only = false,
2579 .ret_type = RET_INTEGER,
2580 .arg1_type = ARG_PTR_TO_CTX,
2581 .arg2_type = ARG_CONST_MAP_PTR,
2582 .arg3_type = ARG_ANYTHING,
2583 };
2584
2585 static unsigned long bpf_xdp_copy(void *dst_buff, const void *src_buff,
2586 unsigned long off, unsigned long len)
2587 {
2588 memcpy(dst_buff, src_buff + off, len);
2589 return 0;
2590 }
2591
2592 BPF_CALL_5(bpf_xdp_event_output, struct xdp_buff *, xdp, struct bpf_map *, map,
2593 u64, flags, void *, meta, u64, meta_size)
2594 {
2595 u64 xdp_size = (flags & BPF_F_CTXLEN_MASK) >> 32;
2596
2597 if (unlikely(flags & ~(BPF_F_CTXLEN_MASK | BPF_F_INDEX_MASK)))
2598 return -EINVAL;
2599 if (unlikely(xdp_size > (unsigned long)(xdp->data_end - xdp->data)))
2600 return -EFAULT;
2601
2602 return bpf_event_output(map, flags, meta, meta_size, xdp->data,
2603 xdp_size, bpf_xdp_copy);
2604 }
2605
2606 static const struct bpf_func_proto bpf_xdp_event_output_proto = {
2607 .func = bpf_xdp_event_output,
2608 .gpl_only = true,
2609 .ret_type = RET_INTEGER,
2610 .arg1_type = ARG_PTR_TO_CTX,
2611 .arg2_type = ARG_CONST_MAP_PTR,
2612 .arg3_type = ARG_ANYTHING,
2613 .arg4_type = ARG_PTR_TO_MEM,
2614 .arg5_type = ARG_CONST_SIZE,
2615 };
2616
2617 BPF_CALL_1(bpf_get_socket_cookie, struct sk_buff *, skb)
2618 {
2619 return skb->sk ? sock_gen_cookie(skb->sk) : 0;
2620 }
2621
2622 static const struct bpf_func_proto bpf_get_socket_cookie_proto = {
2623 .func = bpf_get_socket_cookie,
2624 .gpl_only = false,
2625 .ret_type = RET_INTEGER,
2626 .arg1_type = ARG_PTR_TO_CTX,
2627 };
2628
2629 BPF_CALL_1(bpf_get_socket_uid, struct sk_buff *, skb)
2630 {
2631 struct sock *sk = sk_to_full_sk(skb->sk);
2632 kuid_t kuid;
2633
2634 if (!sk || !sk_fullsock(sk))
2635 return overflowuid;
2636 kuid = sock_net_uid(sock_net(sk), sk);
2637 return from_kuid_munged(sock_net(sk)->user_ns, kuid);
2638 }
2639
2640 static const struct bpf_func_proto bpf_get_socket_uid_proto = {
2641 .func = bpf_get_socket_uid,
2642 .gpl_only = false,
2643 .ret_type = RET_INTEGER,
2644 .arg1_type = ARG_PTR_TO_CTX,
2645 };
2646
2647 static const struct bpf_func_proto *
2648 bpf_base_func_proto(enum bpf_func_id func_id)
2649 {
2650 switch (func_id) {
2651 case BPF_FUNC_map_lookup_elem:
2652 return &bpf_map_lookup_elem_proto;
2653 case BPF_FUNC_map_update_elem:
2654 return &bpf_map_update_elem_proto;
2655 case BPF_FUNC_map_delete_elem:
2656 return &bpf_map_delete_elem_proto;
2657 case BPF_FUNC_get_prandom_u32:
2658 return &bpf_get_prandom_u32_proto;
2659 case BPF_FUNC_get_smp_processor_id:
2660 return &bpf_get_raw_smp_processor_id_proto;
2661 case BPF_FUNC_get_numa_node_id:
2662 return &bpf_get_numa_node_id_proto;
2663 case BPF_FUNC_tail_call:
2664 return &bpf_tail_call_proto;
2665 case BPF_FUNC_ktime_get_ns:
2666 return &bpf_ktime_get_ns_proto;
2667 case BPF_FUNC_trace_printk:
2668 if (capable(CAP_SYS_ADMIN))
2669 return bpf_get_trace_printk_proto();
2670 default:
2671 return NULL;
2672 }
2673 }
2674
2675 static const struct bpf_func_proto *
2676 sk_filter_func_proto(enum bpf_func_id func_id)
2677 {
2678 switch (func_id) {
2679 case BPF_FUNC_skb_load_bytes:
2680 return &bpf_skb_load_bytes_proto;
2681 case BPF_FUNC_get_socket_cookie:
2682 return &bpf_get_socket_cookie_proto;
2683 case BPF_FUNC_get_socket_uid:
2684 return &bpf_get_socket_uid_proto;
2685 default:
2686 return bpf_base_func_proto(func_id);
2687 }
2688 }
2689
2690 static const struct bpf_func_proto *
2691 tc_cls_act_func_proto(enum bpf_func_id func_id)
2692 {
2693 switch (func_id) {
2694 case BPF_FUNC_skb_store_bytes:
2695 return &bpf_skb_store_bytes_proto;
2696 case BPF_FUNC_skb_load_bytes:
2697 return &bpf_skb_load_bytes_proto;
2698 case BPF_FUNC_skb_pull_data:
2699 return &bpf_skb_pull_data_proto;
2700 case BPF_FUNC_csum_diff:
2701 return &bpf_csum_diff_proto;
2702 case BPF_FUNC_csum_update:
2703 return &bpf_csum_update_proto;
2704 case BPF_FUNC_l3_csum_replace:
2705 return &bpf_l3_csum_replace_proto;
2706 case BPF_FUNC_l4_csum_replace:
2707 return &bpf_l4_csum_replace_proto;
2708 case BPF_FUNC_clone_redirect:
2709 return &bpf_clone_redirect_proto;
2710 case BPF_FUNC_get_cgroup_classid:
2711 return &bpf_get_cgroup_classid_proto;
2712 case BPF_FUNC_skb_vlan_push:
2713 return &bpf_skb_vlan_push_proto;
2714 case BPF_FUNC_skb_vlan_pop:
2715 return &bpf_skb_vlan_pop_proto;
2716 case BPF_FUNC_skb_change_proto:
2717 return &bpf_skb_change_proto_proto;
2718 case BPF_FUNC_skb_change_type:
2719 return &bpf_skb_change_type_proto;
2720 case BPF_FUNC_skb_change_tail:
2721 return &bpf_skb_change_tail_proto;
2722 case BPF_FUNC_skb_get_tunnel_key:
2723 return &bpf_skb_get_tunnel_key_proto;
2724 case BPF_FUNC_skb_set_tunnel_key:
2725 return bpf_get_skb_set_tunnel_proto(func_id);
2726 case BPF_FUNC_skb_get_tunnel_opt:
2727 return &bpf_skb_get_tunnel_opt_proto;
2728 case BPF_FUNC_skb_set_tunnel_opt:
2729 return bpf_get_skb_set_tunnel_proto(func_id);
2730 case BPF_FUNC_redirect:
2731 return &bpf_redirect_proto;
2732 case BPF_FUNC_get_route_realm:
2733 return &bpf_get_route_realm_proto;
2734 case BPF_FUNC_get_hash_recalc:
2735 return &bpf_get_hash_recalc_proto;
2736 case BPF_FUNC_set_hash_invalid:
2737 return &bpf_set_hash_invalid_proto;
2738 case BPF_FUNC_perf_event_output:
2739 return &bpf_skb_event_output_proto;
2740 case BPF_FUNC_get_smp_processor_id:
2741 return &bpf_get_smp_processor_id_proto;
2742 case BPF_FUNC_skb_under_cgroup:
2743 return &bpf_skb_under_cgroup_proto;
2744 case BPF_FUNC_get_socket_cookie:
2745 return &bpf_get_socket_cookie_proto;
2746 case BPF_FUNC_get_socket_uid:
2747 return &bpf_get_socket_uid_proto;
2748 default:
2749 return bpf_base_func_proto(func_id);
2750 }
2751 }
2752
2753 static const struct bpf_func_proto *
2754 xdp_func_proto(enum bpf_func_id func_id)
2755 {
2756 switch (func_id) {
2757 case BPF_FUNC_perf_event_output:
2758 return &bpf_xdp_event_output_proto;
2759 case BPF_FUNC_get_smp_processor_id:
2760 return &bpf_get_smp_processor_id_proto;
2761 case BPF_FUNC_xdp_adjust_head:
2762 return &bpf_xdp_adjust_head_proto;
2763 default:
2764 return bpf_base_func_proto(func_id);
2765 }
2766 }
2767
2768 static const struct bpf_func_proto *
2769 cg_skb_func_proto(enum bpf_func_id func_id)
2770 {
2771 return sk_filter_func_proto(func_id);
2772 }
2773
2774 static const struct bpf_func_proto *
2775 lwt_inout_func_proto(enum bpf_func_id func_id)
2776 {
2777 switch (func_id) {
2778 case BPF_FUNC_skb_load_bytes:
2779 return &bpf_skb_load_bytes_proto;
2780 case BPF_FUNC_skb_pull_data:
2781 return &bpf_skb_pull_data_proto;
2782 case BPF_FUNC_csum_diff:
2783 return &bpf_csum_diff_proto;
2784 case BPF_FUNC_get_cgroup_classid:
2785 return &bpf_get_cgroup_classid_proto;
2786 case BPF_FUNC_get_route_realm:
2787 return &bpf_get_route_realm_proto;
2788 case BPF_FUNC_get_hash_recalc:
2789 return &bpf_get_hash_recalc_proto;
2790 case BPF_FUNC_perf_event_output:
2791 return &bpf_skb_event_output_proto;
2792 case BPF_FUNC_get_smp_processor_id:
2793 return &bpf_get_smp_processor_id_proto;
2794 case BPF_FUNC_skb_under_cgroup:
2795 return &bpf_skb_under_cgroup_proto;
2796 default:
2797 return bpf_base_func_proto(func_id);
2798 }
2799 }
2800
2801 static const struct bpf_func_proto *
2802 lwt_xmit_func_proto(enum bpf_func_id func_id)
2803 {
2804 switch (func_id) {
2805 case BPF_FUNC_skb_get_tunnel_key:
2806 return &bpf_skb_get_tunnel_key_proto;
2807 case BPF_FUNC_skb_set_tunnel_key:
2808 return bpf_get_skb_set_tunnel_proto(func_id);
2809 case BPF_FUNC_skb_get_tunnel_opt:
2810 return &bpf_skb_get_tunnel_opt_proto;
2811 case BPF_FUNC_skb_set_tunnel_opt:
2812 return bpf_get_skb_set_tunnel_proto(func_id);
2813 case BPF_FUNC_redirect:
2814 return &bpf_redirect_proto;
2815 case BPF_FUNC_clone_redirect:
2816 return &bpf_clone_redirect_proto;
2817 case BPF_FUNC_skb_change_tail:
2818 return &bpf_skb_change_tail_proto;
2819 case BPF_FUNC_skb_change_head:
2820 return &bpf_skb_change_head_proto;
2821 case BPF_FUNC_skb_store_bytes:
2822 return &bpf_skb_store_bytes_proto;
2823 case BPF_FUNC_csum_update:
2824 return &bpf_csum_update_proto;
2825 case BPF_FUNC_l3_csum_replace:
2826 return &bpf_l3_csum_replace_proto;
2827 case BPF_FUNC_l4_csum_replace:
2828 return &bpf_l4_csum_replace_proto;
2829 case BPF_FUNC_set_hash_invalid:
2830 return &bpf_set_hash_invalid_proto;
2831 default:
2832 return lwt_inout_func_proto(func_id);
2833 }
2834 }
2835
2836 static bool __is_valid_access(int off, int size)
2837 {
2838 if (off < 0 || off >= sizeof(struct __sk_buff))
2839 return false;
2840
2841 /* The verifier guarantees that size > 0. */
2842 if (off % size != 0)
2843 return false;
2844
2845 switch (off) {
2846 case offsetof(struct __sk_buff, cb[0]) ...
2847 offsetof(struct __sk_buff, cb[4]) + sizeof(__u32) - 1:
2848 if (off + size >
2849 offsetof(struct __sk_buff, cb[4]) + sizeof(__u32))
2850 return false;
2851 break;
2852 default:
2853 if (size != sizeof(__u32))
2854 return false;
2855 }
2856
2857 return true;
2858 }
2859
2860 static bool sk_filter_is_valid_access(int off, int size,
2861 enum bpf_access_type type,
2862 enum bpf_reg_type *reg_type)
2863 {
2864 switch (off) {
2865 case offsetof(struct __sk_buff, tc_classid):
2866 case offsetof(struct __sk_buff, data):
2867 case offsetof(struct __sk_buff, data_end):
2868 return false;
2869 }
2870
2871 if (type == BPF_WRITE) {
2872 switch (off) {
2873 case offsetof(struct __sk_buff, cb[0]) ...
2874 offsetof(struct __sk_buff, cb[4]) + sizeof(__u32) - 1:
2875 break;
2876 default:
2877 return false;
2878 }
2879 }
2880
2881 return __is_valid_access(off, size);
2882 }
2883
2884 static bool lwt_is_valid_access(int off, int size,
2885 enum bpf_access_type type,
2886 enum bpf_reg_type *reg_type)
2887 {
2888 switch (off) {
2889 case offsetof(struct __sk_buff, tc_classid):
2890 return false;
2891 }
2892
2893 if (type == BPF_WRITE) {
2894 switch (off) {
2895 case offsetof(struct __sk_buff, mark):
2896 case offsetof(struct __sk_buff, priority):
2897 case offsetof(struct __sk_buff, cb[0]) ...
2898 offsetof(struct __sk_buff, cb[4]) + sizeof(__u32) - 1:
2899 break;
2900 default:
2901 return false;
2902 }
2903 }
2904
2905 switch (off) {
2906 case offsetof(struct __sk_buff, data):
2907 *reg_type = PTR_TO_PACKET;
2908 break;
2909 case offsetof(struct __sk_buff, data_end):
2910 *reg_type = PTR_TO_PACKET_END;
2911 break;
2912 }
2913
2914 return __is_valid_access(off, size);
2915 }
2916
2917 static bool sock_filter_is_valid_access(int off, int size,
2918 enum bpf_access_type type,
2919 enum bpf_reg_type *reg_type)
2920 {
2921 if (type == BPF_WRITE) {
2922 switch (off) {
2923 case offsetof(struct bpf_sock, bound_dev_if):
2924 break;
2925 default:
2926 return false;
2927 }
2928 }
2929
2930 if (off < 0 || off + size > sizeof(struct bpf_sock))
2931 return false;
2932 /* The verifier guarantees that size > 0. */
2933 if (off % size != 0)
2934 return false;
2935 if (size != sizeof(__u32))
2936 return false;
2937
2938 return true;
2939 }
2940
2941 static int tc_cls_act_prologue(struct bpf_insn *insn_buf, bool direct_write,
2942 const struct bpf_prog *prog)
2943 {
2944 struct bpf_insn *insn = insn_buf;
2945
2946 if (!direct_write)
2947 return 0;
2948
2949 /* if (!skb->cloned)
2950 * goto start;
2951 *
2952 * (Fast-path, otherwise approximation that we might be
2953 * a clone, do the rest in helper.)
2954 */
2955 *insn++ = BPF_LDX_MEM(BPF_B, BPF_REG_6, BPF_REG_1, CLONED_OFFSET());
2956 *insn++ = BPF_ALU32_IMM(BPF_AND, BPF_REG_6, CLONED_MASK);
2957 *insn++ = BPF_JMP_IMM(BPF_JEQ, BPF_REG_6, 0, 7);
2958
2959 /* ret = bpf_skb_pull_data(skb, 0); */
2960 *insn++ = BPF_MOV64_REG(BPF_REG_6, BPF_REG_1);
2961 *insn++ = BPF_ALU64_REG(BPF_XOR, BPF_REG_2, BPF_REG_2);
2962 *insn++ = BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
2963 BPF_FUNC_skb_pull_data);
2964 /* if (!ret)
2965 * goto restore;
2966 * return TC_ACT_SHOT;
2967 */
2968 *insn++ = BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 2);
2969 *insn++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_0, TC_ACT_SHOT);
2970 *insn++ = BPF_EXIT_INSN();
2971
2972 /* restore: */
2973 *insn++ = BPF_MOV64_REG(BPF_REG_1, BPF_REG_6);
2974 /* start: */
2975 *insn++ = prog->insnsi[0];
2976
2977 return insn - insn_buf;
2978 }
2979
2980 static bool tc_cls_act_is_valid_access(int off, int size,
2981 enum bpf_access_type type,
2982 enum bpf_reg_type *reg_type)
2983 {
2984 if (type == BPF_WRITE) {
2985 switch (off) {
2986 case offsetof(struct __sk_buff, mark):
2987 case offsetof(struct __sk_buff, tc_index):
2988 case offsetof(struct __sk_buff, priority):
2989 case offsetof(struct __sk_buff, cb[0]) ...
2990 offsetof(struct __sk_buff, cb[4]) + sizeof(__u32) - 1:
2991 case offsetof(struct __sk_buff, tc_classid):
2992 break;
2993 default:
2994 return false;
2995 }
2996 }
2997
2998 switch (off) {
2999 case offsetof(struct __sk_buff, data):
3000 *reg_type = PTR_TO_PACKET;
3001 break;
3002 case offsetof(struct __sk_buff, data_end):
3003 *reg_type = PTR_TO_PACKET_END;
3004 break;
3005 }
3006
3007 return __is_valid_access(off, size);
3008 }
3009
3010 static bool __is_valid_xdp_access(int off, int size)
3011 {
3012 if (off < 0 || off >= sizeof(struct xdp_md))
3013 return false;
3014 if (off % size != 0)
3015 return false;
3016 if (size != sizeof(__u32))
3017 return false;
3018
3019 return true;
3020 }
3021
3022 static bool xdp_is_valid_access(int off, int size,
3023 enum bpf_access_type type,
3024 enum bpf_reg_type *reg_type)
3025 {
3026 if (type == BPF_WRITE)
3027 return false;
3028
3029 switch (off) {
3030 case offsetof(struct xdp_md, data):
3031 *reg_type = PTR_TO_PACKET;
3032 break;
3033 case offsetof(struct xdp_md, data_end):
3034 *reg_type = PTR_TO_PACKET_END;
3035 break;
3036 }
3037
3038 return __is_valid_xdp_access(off, size);
3039 }
3040
3041 void bpf_warn_invalid_xdp_action(u32 act)
3042 {
3043 WARN_ONCE(1, "Illegal XDP return value %u, expect packet loss\n", act);
3044 }
3045 EXPORT_SYMBOL_GPL(bpf_warn_invalid_xdp_action);
3046
3047 static u32 bpf_convert_ctx_access(enum bpf_access_type type,
3048 const struct bpf_insn *si,
3049 struct bpf_insn *insn_buf,
3050 struct bpf_prog *prog)
3051 {
3052 struct bpf_insn *insn = insn_buf;
3053 int off;
3054
3055 switch (si->off) {
3056 case offsetof(struct __sk_buff, len):
3057 BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, len) != 4);
3058
3059 *insn++ = BPF_LDX_MEM(BPF_W, si->dst_reg, si->src_reg,
3060 offsetof(struct sk_buff, len));
3061 break;
3062
3063 case offsetof(struct __sk_buff, protocol):
3064 BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, protocol) != 2);
3065
3066 *insn++ = BPF_LDX_MEM(BPF_H, si->dst_reg, si->src_reg,
3067 offsetof(struct sk_buff, protocol));
3068 break;
3069
3070 case offsetof(struct __sk_buff, vlan_proto):
3071 BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, vlan_proto) != 2);
3072
3073 *insn++ = BPF_LDX_MEM(BPF_H, si->dst_reg, si->src_reg,
3074 offsetof(struct sk_buff, vlan_proto));
3075 break;
3076
3077 case offsetof(struct __sk_buff, priority):
3078 BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, priority) != 4);
3079
3080 if (type == BPF_WRITE)
3081 *insn++ = BPF_STX_MEM(BPF_W, si->dst_reg, si->src_reg,
3082 offsetof(struct sk_buff, priority));
3083 else
3084 *insn++ = BPF_LDX_MEM(BPF_W, si->dst_reg, si->src_reg,
3085 offsetof(struct sk_buff, priority));
3086 break;
3087
3088 case offsetof(struct __sk_buff, ingress_ifindex):
3089 BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, skb_iif) != 4);
3090
3091 *insn++ = BPF_LDX_MEM(BPF_W, si->dst_reg, si->src_reg,
3092 offsetof(struct sk_buff, skb_iif));
3093 break;
3094
3095 case offsetof(struct __sk_buff, ifindex):
3096 BUILD_BUG_ON(FIELD_SIZEOF(struct net_device, ifindex) != 4);
3097
3098 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct sk_buff, dev),
3099 si->dst_reg, si->src_reg,
3100 offsetof(struct sk_buff, dev));
3101 *insn++ = BPF_JMP_IMM(BPF_JEQ, si->dst_reg, 0, 1);
3102 *insn++ = BPF_LDX_MEM(BPF_W, si->dst_reg, si->dst_reg,
3103 offsetof(struct net_device, ifindex));
3104 break;
3105
3106 case offsetof(struct __sk_buff, hash):
3107 BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, hash) != 4);
3108
3109 *insn++ = BPF_LDX_MEM(BPF_W, si->dst_reg, si->src_reg,
3110 offsetof(struct sk_buff, hash));
3111 break;
3112
3113 case offsetof(struct __sk_buff, mark):
3114 BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, mark) != 4);
3115
3116 if (type == BPF_WRITE)
3117 *insn++ = BPF_STX_MEM(BPF_W, si->dst_reg, si->src_reg,
3118 offsetof(struct sk_buff, mark));
3119 else
3120 *insn++ = BPF_LDX_MEM(BPF_W, si->dst_reg, si->src_reg,
3121 offsetof(struct sk_buff, mark));
3122 break;
3123
3124 case offsetof(struct __sk_buff, pkt_type):
3125 return convert_skb_access(SKF_AD_PKTTYPE, si->dst_reg,
3126 si->src_reg, insn);
3127
3128 case offsetof(struct __sk_buff, queue_mapping):
3129 return convert_skb_access(SKF_AD_QUEUE, si->dst_reg,
3130 si->src_reg, insn);
3131
3132 case offsetof(struct __sk_buff, vlan_present):
3133 return convert_skb_access(SKF_AD_VLAN_TAG_PRESENT,
3134 si->dst_reg, si->src_reg, insn);
3135
3136 case offsetof(struct __sk_buff, vlan_tci):
3137 return convert_skb_access(SKF_AD_VLAN_TAG,
3138 si->dst_reg, si->src_reg, insn);
3139
3140 case offsetof(struct __sk_buff, cb[0]) ...
3141 offsetof(struct __sk_buff, cb[4]) + sizeof(__u32) - 1:
3142 BUILD_BUG_ON(FIELD_SIZEOF(struct qdisc_skb_cb, data) < 20);
3143 BUILD_BUG_ON((offsetof(struct sk_buff, cb) +
3144 offsetof(struct qdisc_skb_cb, data)) %
3145 sizeof(__u64));
3146
3147 prog->cb_access = 1;
3148 off = si->off;
3149 off -= offsetof(struct __sk_buff, cb[0]);
3150 off += offsetof(struct sk_buff, cb);
3151 off += offsetof(struct qdisc_skb_cb, data);
3152 if (type == BPF_WRITE)
3153 *insn++ = BPF_STX_MEM(BPF_SIZE(si->code), si->dst_reg,
3154 si->src_reg, off);
3155 else
3156 *insn++ = BPF_LDX_MEM(BPF_SIZE(si->code), si->dst_reg,
3157 si->src_reg, off);
3158 break;
3159
3160 case offsetof(struct __sk_buff, tc_classid):
3161 BUILD_BUG_ON(FIELD_SIZEOF(struct qdisc_skb_cb, tc_classid) != 2);
3162
3163 off = si->off;
3164 off -= offsetof(struct __sk_buff, tc_classid);
3165 off += offsetof(struct sk_buff, cb);
3166 off += offsetof(struct qdisc_skb_cb, tc_classid);
3167 if (type == BPF_WRITE)
3168 *insn++ = BPF_STX_MEM(BPF_H, si->dst_reg,
3169 si->src_reg, off);
3170 else
3171 *insn++ = BPF_LDX_MEM(BPF_H, si->dst_reg,
3172 si->src_reg, off);
3173 break;
3174
3175 case offsetof(struct __sk_buff, data):
3176 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct sk_buff, data),
3177 si->dst_reg, si->src_reg,
3178 offsetof(struct sk_buff, data));
3179 break;
3180
3181 case offsetof(struct __sk_buff, data_end):
3182 off = si->off;
3183 off -= offsetof(struct __sk_buff, data_end);
3184 off += offsetof(struct sk_buff, cb);
3185 off += offsetof(struct bpf_skb_data_end, data_end);
3186 *insn++ = BPF_LDX_MEM(BPF_SIZEOF(void *), si->dst_reg,
3187 si->src_reg, off);
3188 break;
3189
3190 case offsetof(struct __sk_buff, tc_index):
3191 #ifdef CONFIG_NET_SCHED
3192 BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, tc_index) != 2);
3193
3194 if (type == BPF_WRITE)
3195 *insn++ = BPF_STX_MEM(BPF_H, si->dst_reg, si->src_reg,
3196 offsetof(struct sk_buff, tc_index));
3197 else
3198 *insn++ = BPF_LDX_MEM(BPF_H, si->dst_reg, si->src_reg,
3199 offsetof(struct sk_buff, tc_index));
3200 #else
3201 if (type == BPF_WRITE)
3202 *insn++ = BPF_MOV64_REG(si->dst_reg, si->dst_reg);
3203 else
3204 *insn++ = BPF_MOV64_IMM(si->dst_reg, 0);
3205 #endif
3206 break;
3207
3208 case offsetof(struct __sk_buff, napi_id):
3209 #if defined(CONFIG_NET_RX_BUSY_POLL)
3210 BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, napi_id) != 4);
3211
3212 *insn++ = BPF_LDX_MEM(BPF_W, si->dst_reg, si->src_reg,
3213 offsetof(struct sk_buff, napi_id));
3214 *insn++ = BPF_JMP_IMM(BPF_JGE, si->dst_reg, MIN_NAPI_ID, 1);
3215 *insn++ = BPF_MOV64_IMM(si->dst_reg, 0);
3216 #else
3217 *insn++ = BPF_MOV64_IMM(si->dst_reg, 0);
3218 #endif
3219 break;
3220 }
3221
3222 return insn - insn_buf;
3223 }
3224
3225 static u32 sock_filter_convert_ctx_access(enum bpf_access_type type,
3226 const struct bpf_insn *si,
3227 struct bpf_insn *insn_buf,
3228 struct bpf_prog *prog)
3229 {
3230 struct bpf_insn *insn = insn_buf;
3231
3232 switch (si->off) {
3233 case offsetof(struct bpf_sock, bound_dev_if):
3234 BUILD_BUG_ON(FIELD_SIZEOF(struct sock, sk_bound_dev_if) != 4);
3235
3236 if (type == BPF_WRITE)
3237 *insn++ = BPF_STX_MEM(BPF_W, si->dst_reg, si->src_reg,
3238 offsetof(struct sock, sk_bound_dev_if));
3239 else
3240 *insn++ = BPF_LDX_MEM(BPF_W, si->dst_reg, si->src_reg,
3241 offsetof(struct sock, sk_bound_dev_if));
3242 break;
3243
3244 case offsetof(struct bpf_sock, family):
3245 BUILD_BUG_ON(FIELD_SIZEOF(struct sock, sk_family) != 2);
3246
3247 *insn++ = BPF_LDX_MEM(BPF_H, si->dst_reg, si->src_reg,
3248 offsetof(struct sock, sk_family));
3249 break;
3250
3251 case offsetof(struct bpf_sock, type):
3252 *insn++ = BPF_LDX_MEM(BPF_W, si->dst_reg, si->src_reg,
3253 offsetof(struct sock, __sk_flags_offset));
3254 *insn++ = BPF_ALU32_IMM(BPF_AND, si->dst_reg, SK_FL_TYPE_MASK);
3255 *insn++ = BPF_ALU32_IMM(BPF_RSH, si->dst_reg, SK_FL_TYPE_SHIFT);
3256 break;
3257
3258 case offsetof(struct bpf_sock, protocol):
3259 *insn++ = BPF_LDX_MEM(BPF_W, si->dst_reg, si->src_reg,
3260 offsetof(struct sock, __sk_flags_offset));
3261 *insn++ = BPF_ALU32_IMM(BPF_AND, si->dst_reg, SK_FL_PROTO_MASK);
3262 *insn++ = BPF_ALU32_IMM(BPF_RSH, si->dst_reg, SK_FL_PROTO_SHIFT);
3263 break;
3264 }
3265
3266 return insn - insn_buf;
3267 }
3268
3269 static u32 tc_cls_act_convert_ctx_access(enum bpf_access_type type,
3270 const struct bpf_insn *si,
3271 struct bpf_insn *insn_buf,
3272 struct bpf_prog *prog)
3273 {
3274 struct bpf_insn *insn = insn_buf;
3275
3276 switch (si->off) {
3277 case offsetof(struct __sk_buff, ifindex):
3278 BUILD_BUG_ON(FIELD_SIZEOF(struct net_device, ifindex) != 4);
3279
3280 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct sk_buff, dev),
3281 si->dst_reg, si->src_reg,
3282 offsetof(struct sk_buff, dev));
3283 *insn++ = BPF_LDX_MEM(BPF_W, si->dst_reg, si->dst_reg,
3284 offsetof(struct net_device, ifindex));
3285 break;
3286 default:
3287 return bpf_convert_ctx_access(type, si, insn_buf, prog);
3288 }
3289
3290 return insn - insn_buf;
3291 }
3292
3293 static u32 xdp_convert_ctx_access(enum bpf_access_type type,
3294 const struct bpf_insn *si,
3295 struct bpf_insn *insn_buf,
3296 struct bpf_prog *prog)
3297 {
3298 struct bpf_insn *insn = insn_buf;
3299
3300 switch (si->off) {
3301 case offsetof(struct xdp_md, data):
3302 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct xdp_buff, data),
3303 si->dst_reg, si->src_reg,
3304 offsetof(struct xdp_buff, data));
3305 break;
3306 case offsetof(struct xdp_md, data_end):
3307 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct xdp_buff, data_end),
3308 si->dst_reg, si->src_reg,
3309 offsetof(struct xdp_buff, data_end));
3310 break;
3311 }
3312
3313 return insn - insn_buf;
3314 }
3315
3316 const struct bpf_verifier_ops sk_filter_prog_ops = {
3317 .get_func_proto = sk_filter_func_proto,
3318 .is_valid_access = sk_filter_is_valid_access,
3319 .convert_ctx_access = bpf_convert_ctx_access,
3320 };
3321
3322 const struct bpf_verifier_ops tc_cls_act_prog_ops = {
3323 .get_func_proto = tc_cls_act_func_proto,
3324 .is_valid_access = tc_cls_act_is_valid_access,
3325 .convert_ctx_access = tc_cls_act_convert_ctx_access,
3326 .gen_prologue = tc_cls_act_prologue,
3327 .test_run = bpf_prog_test_run_skb,
3328 };
3329
3330 const struct bpf_verifier_ops xdp_prog_ops = {
3331 .get_func_proto = xdp_func_proto,
3332 .is_valid_access = xdp_is_valid_access,
3333 .convert_ctx_access = xdp_convert_ctx_access,
3334 .test_run = bpf_prog_test_run_xdp,
3335 };
3336
3337 const struct bpf_verifier_ops cg_skb_prog_ops = {
3338 .get_func_proto = cg_skb_func_proto,
3339 .is_valid_access = sk_filter_is_valid_access,
3340 .convert_ctx_access = bpf_convert_ctx_access,
3341 .test_run = bpf_prog_test_run_skb,
3342 };
3343
3344 const struct bpf_verifier_ops lwt_inout_prog_ops = {
3345 .get_func_proto = lwt_inout_func_proto,
3346 .is_valid_access = lwt_is_valid_access,
3347 .convert_ctx_access = bpf_convert_ctx_access,
3348 .test_run = bpf_prog_test_run_skb,
3349 };
3350
3351 const struct bpf_verifier_ops lwt_xmit_prog_ops = {
3352 .get_func_proto = lwt_xmit_func_proto,
3353 .is_valid_access = lwt_is_valid_access,
3354 .convert_ctx_access = bpf_convert_ctx_access,
3355 .gen_prologue = tc_cls_act_prologue,
3356 .test_run = bpf_prog_test_run_skb,
3357 };
3358
3359 const struct bpf_verifier_ops cg_sock_prog_ops = {
3360 .get_func_proto = bpf_base_func_proto,
3361 .is_valid_access = sock_filter_is_valid_access,
3362 .convert_ctx_access = sock_filter_convert_ctx_access,
3363 };
3364
3365 int sk_detach_filter(struct sock *sk)
3366 {
3367 int ret = -ENOENT;
3368 struct sk_filter *filter;
3369
3370 if (sock_flag(sk, SOCK_FILTER_LOCKED))
3371 return -EPERM;
3372
3373 filter = rcu_dereference_protected(sk->sk_filter,
3374 lockdep_sock_is_held(sk));
3375 if (filter) {
3376 RCU_INIT_POINTER(sk->sk_filter, NULL);
3377 sk_filter_uncharge(sk, filter);
3378 ret = 0;
3379 }
3380
3381 return ret;
3382 }
3383 EXPORT_SYMBOL_GPL(sk_detach_filter);
3384
3385 int sk_get_filter(struct sock *sk, struct sock_filter __user *ubuf,
3386 unsigned int len)
3387 {
3388 struct sock_fprog_kern *fprog;
3389 struct sk_filter *filter;
3390 int ret = 0;
3391
3392 lock_sock(sk);
3393 filter = rcu_dereference_protected(sk->sk_filter,
3394 lockdep_sock_is_held(sk));
3395 if (!filter)
3396 goto out;
3397
3398 /* We're copying the filter that has been originally attached,
3399 * so no conversion/decode needed anymore. eBPF programs that
3400 * have no original program cannot be dumped through this.
3401 */
3402 ret = -EACCES;
3403 fprog = filter->prog->orig_prog;
3404 if (!fprog)
3405 goto out;
3406
3407 ret = fprog->len;
3408 if (!len)
3409 /* User space only enquires number of filter blocks. */
3410 goto out;
3411
3412 ret = -EINVAL;
3413 if (len < fprog->len)
3414 goto out;
3415
3416 ret = -EFAULT;
3417 if (copy_to_user(ubuf, fprog->filter, bpf_classic_proglen(fprog)))
3418 goto out;
3419
3420 /* Instead of bytes, the API requests to return the number
3421 * of filter blocks.
3422 */
3423 ret = fprog->len;
3424 out:
3425 release_sock(sk);
3426 return ret;
3427 }
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