2 * Linux Socket Filter - Kernel level socket filtering
4 * Based on the design of the Berkeley Packet Filter. The new
5 * internal format has been designed by PLUMgrid:
7 * Copyright (c) 2011 - 2014 PLUMgrid, http://plumgrid.com
11 * Jay Schulist <jschlst@samba.org>
12 * Alexei Starovoitov <ast@plumgrid.com>
13 * Daniel Borkmann <dborkman@redhat.com>
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.
20 * Andi Kleen - Fix a few bad bugs and races.
21 * Kris Katterjohn - Added many additional checks in bpf_check_classic()
24 #include <linux/module.h>
25 #include <linux/types.h>
27 #include <linux/fcntl.h>
28 #include <linux/socket.h>
30 #include <linux/inet.h>
31 #include <linux/netdevice.h>
32 #include <linux/if_packet.h>
33 #include <linux/gfp.h>
35 #include <net/protocol.h>
36 #include <net/netlink.h>
37 #include <linux/skbuff.h>
39 #include <net/flow_dissector.h>
40 #include <linux/errno.h>
41 #include <linux/timer.h>
42 #include <asm/uaccess.h>
43 #include <asm/unaligned.h>
44 #include <linux/filter.h>
45 #include <linux/ratelimit.h>
46 #include <linux/seccomp.h>
47 #include <linux/if_vlan.h>
48 #include <linux/bpf.h>
49 #include <net/sch_generic.h>
50 #include <net/cls_cgroup.h>
51 #include <net/dst_metadata.h>
53 #include <net/sock_reuseport.h>
56 * sk_filter - run a packet through a socket filter
57 * @sk: sock associated with &sk_buff
58 * @skb: buffer to filter
60 * Run the eBPF program and then cut skb->data to correct size returned by
61 * the program. If pkt_len is 0 we toss packet. If skb->len is smaller
62 * than pkt_len we keep whole skb->data. This is the socket level
63 * wrapper to BPF_PROG_RUN. It returns 0 if the packet should
64 * be accepted or -EPERM if the packet should be tossed.
67 int sk_filter(struct sock
*sk
, struct sk_buff
*skb
)
70 struct sk_filter
*filter
;
73 * If the skb was allocated from pfmemalloc reserves, only
74 * allow SOCK_MEMALLOC sockets to use it as this socket is
77 if (skb_pfmemalloc(skb
) && !sock_flag(sk
, SOCK_MEMALLOC
))
80 err
= security_sock_rcv_skb(sk
, skb
);
85 filter
= rcu_dereference(sk
->sk_filter
);
87 unsigned int pkt_len
= bpf_prog_run_save_cb(filter
->prog
, skb
);
89 err
= pkt_len
? pskb_trim(skb
, pkt_len
) : -EPERM
;
95 EXPORT_SYMBOL(sk_filter
);
97 static u64
__skb_get_pay_offset(u64 ctx
, u64 a
, u64 x
, u64 r4
, u64 r5
)
99 return skb_get_poff((struct sk_buff
*)(unsigned long) ctx
);
102 static u64
__skb_get_nlattr(u64 ctx
, u64 a
, u64 x
, u64 r4
, u64 r5
)
104 struct sk_buff
*skb
= (struct sk_buff
*)(unsigned long) ctx
;
107 if (skb_is_nonlinear(skb
))
110 if (skb
->len
< sizeof(struct nlattr
))
113 if (a
> skb
->len
- sizeof(struct nlattr
))
116 nla
= nla_find((struct nlattr
*) &skb
->data
[a
], skb
->len
- a
, x
);
118 return (void *) nla
- (void *) skb
->data
;
123 static u64
__skb_get_nlattr_nest(u64 ctx
, u64 a
, u64 x
, u64 r4
, u64 r5
)
125 struct sk_buff
*skb
= (struct sk_buff
*)(unsigned long) ctx
;
128 if (skb_is_nonlinear(skb
))
131 if (skb
->len
< sizeof(struct nlattr
))
134 if (a
> skb
->len
- sizeof(struct nlattr
))
137 nla
= (struct nlattr
*) &skb
->data
[a
];
138 if (nla
->nla_len
> skb
->len
- a
)
141 nla
= nla_find_nested(nla
, x
);
143 return (void *) nla
- (void *) skb
->data
;
148 static u64
__get_raw_cpu_id(u64 ctx
, u64 a
, u64 x
, u64 r4
, u64 r5
)
150 return raw_smp_processor_id();
153 static u32
convert_skb_access(int skb_field
, int dst_reg
, int src_reg
,
154 struct bpf_insn
*insn_buf
)
156 struct bpf_insn
*insn
= insn_buf
;
160 BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff
, mark
) != 4);
162 *insn
++ = BPF_LDX_MEM(BPF_W
, dst_reg
, src_reg
,
163 offsetof(struct sk_buff
, mark
));
167 *insn
++ = BPF_LDX_MEM(BPF_B
, dst_reg
, src_reg
, PKT_TYPE_OFFSET());
168 *insn
++ = BPF_ALU32_IMM(BPF_AND
, dst_reg
, PKT_TYPE_MAX
);
169 #ifdef __BIG_ENDIAN_BITFIELD
170 *insn
++ = BPF_ALU32_IMM(BPF_RSH
, dst_reg
, 5);
175 BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff
, queue_mapping
) != 2);
177 *insn
++ = BPF_LDX_MEM(BPF_H
, dst_reg
, src_reg
,
178 offsetof(struct sk_buff
, queue_mapping
));
181 case SKF_AD_VLAN_TAG
:
182 case SKF_AD_VLAN_TAG_PRESENT
:
183 BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff
, vlan_tci
) != 2);
184 BUILD_BUG_ON(VLAN_TAG_PRESENT
!= 0x1000);
186 /* dst_reg = *(u16 *) (src_reg + offsetof(vlan_tci)) */
187 *insn
++ = BPF_LDX_MEM(BPF_H
, dst_reg
, src_reg
,
188 offsetof(struct sk_buff
, vlan_tci
));
189 if (skb_field
== SKF_AD_VLAN_TAG
) {
190 *insn
++ = BPF_ALU32_IMM(BPF_AND
, dst_reg
,
194 *insn
++ = BPF_ALU32_IMM(BPF_RSH
, dst_reg
, 12);
196 *insn
++ = BPF_ALU32_IMM(BPF_AND
, dst_reg
, 1);
201 return insn
- insn_buf
;
204 static bool convert_bpf_extensions(struct sock_filter
*fp
,
205 struct bpf_insn
**insnp
)
207 struct bpf_insn
*insn
= *insnp
;
211 case SKF_AD_OFF
+ SKF_AD_PROTOCOL
:
212 BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff
, protocol
) != 2);
214 /* A = *(u16 *) (CTX + offsetof(protocol)) */
215 *insn
++ = BPF_LDX_MEM(BPF_H
, BPF_REG_A
, BPF_REG_CTX
,
216 offsetof(struct sk_buff
, protocol
));
217 /* A = ntohs(A) [emitting a nop or swap16] */
218 *insn
= BPF_ENDIAN(BPF_FROM_BE
, BPF_REG_A
, 16);
221 case SKF_AD_OFF
+ SKF_AD_PKTTYPE
:
222 cnt
= convert_skb_access(SKF_AD_PKTTYPE
, BPF_REG_A
, BPF_REG_CTX
, insn
);
226 case SKF_AD_OFF
+ SKF_AD_IFINDEX
:
227 case SKF_AD_OFF
+ SKF_AD_HATYPE
:
228 BUILD_BUG_ON(FIELD_SIZEOF(struct net_device
, ifindex
) != 4);
229 BUILD_BUG_ON(FIELD_SIZEOF(struct net_device
, type
) != 2);
230 BUILD_BUG_ON(bytes_to_bpf_size(FIELD_SIZEOF(struct sk_buff
, dev
)) < 0);
232 *insn
++ = BPF_LDX_MEM(bytes_to_bpf_size(FIELD_SIZEOF(struct sk_buff
, dev
)),
233 BPF_REG_TMP
, BPF_REG_CTX
,
234 offsetof(struct sk_buff
, dev
));
235 /* if (tmp != 0) goto pc + 1 */
236 *insn
++ = BPF_JMP_IMM(BPF_JNE
, BPF_REG_TMP
, 0, 1);
237 *insn
++ = BPF_EXIT_INSN();
238 if (fp
->k
== SKF_AD_OFF
+ SKF_AD_IFINDEX
)
239 *insn
= BPF_LDX_MEM(BPF_W
, BPF_REG_A
, BPF_REG_TMP
,
240 offsetof(struct net_device
, ifindex
));
242 *insn
= BPF_LDX_MEM(BPF_H
, BPF_REG_A
, BPF_REG_TMP
,
243 offsetof(struct net_device
, type
));
246 case SKF_AD_OFF
+ SKF_AD_MARK
:
247 cnt
= convert_skb_access(SKF_AD_MARK
, BPF_REG_A
, BPF_REG_CTX
, insn
);
251 case SKF_AD_OFF
+ SKF_AD_RXHASH
:
252 BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff
, hash
) != 4);
254 *insn
= BPF_LDX_MEM(BPF_W
, BPF_REG_A
, BPF_REG_CTX
,
255 offsetof(struct sk_buff
, hash
));
258 case SKF_AD_OFF
+ SKF_AD_QUEUE
:
259 cnt
= convert_skb_access(SKF_AD_QUEUE
, BPF_REG_A
, BPF_REG_CTX
, insn
);
263 case SKF_AD_OFF
+ SKF_AD_VLAN_TAG
:
264 cnt
= convert_skb_access(SKF_AD_VLAN_TAG
,
265 BPF_REG_A
, BPF_REG_CTX
, insn
);
269 case SKF_AD_OFF
+ SKF_AD_VLAN_TAG_PRESENT
:
270 cnt
= convert_skb_access(SKF_AD_VLAN_TAG_PRESENT
,
271 BPF_REG_A
, BPF_REG_CTX
, insn
);
275 case SKF_AD_OFF
+ SKF_AD_VLAN_TPID
:
276 BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff
, vlan_proto
) != 2);
278 /* A = *(u16 *) (CTX + offsetof(vlan_proto)) */
279 *insn
++ = BPF_LDX_MEM(BPF_H
, BPF_REG_A
, BPF_REG_CTX
,
280 offsetof(struct sk_buff
, vlan_proto
));
281 /* A = ntohs(A) [emitting a nop or swap16] */
282 *insn
= BPF_ENDIAN(BPF_FROM_BE
, BPF_REG_A
, 16);
285 case SKF_AD_OFF
+ SKF_AD_PAY_OFFSET
:
286 case SKF_AD_OFF
+ SKF_AD_NLATTR
:
287 case SKF_AD_OFF
+ SKF_AD_NLATTR_NEST
:
288 case SKF_AD_OFF
+ SKF_AD_CPU
:
289 case SKF_AD_OFF
+ SKF_AD_RANDOM
:
291 *insn
++ = BPF_MOV64_REG(BPF_REG_ARG1
, BPF_REG_CTX
);
293 *insn
++ = BPF_MOV64_REG(BPF_REG_ARG2
, BPF_REG_A
);
295 *insn
++ = BPF_MOV64_REG(BPF_REG_ARG3
, BPF_REG_X
);
296 /* Emit call(arg1=CTX, arg2=A, arg3=X) */
298 case SKF_AD_OFF
+ SKF_AD_PAY_OFFSET
:
299 *insn
= BPF_EMIT_CALL(__skb_get_pay_offset
);
301 case SKF_AD_OFF
+ SKF_AD_NLATTR
:
302 *insn
= BPF_EMIT_CALL(__skb_get_nlattr
);
304 case SKF_AD_OFF
+ SKF_AD_NLATTR_NEST
:
305 *insn
= BPF_EMIT_CALL(__skb_get_nlattr_nest
);
307 case SKF_AD_OFF
+ SKF_AD_CPU
:
308 *insn
= BPF_EMIT_CALL(__get_raw_cpu_id
);
310 case SKF_AD_OFF
+ SKF_AD_RANDOM
:
311 *insn
= BPF_EMIT_CALL(bpf_user_rnd_u32
);
312 bpf_user_rnd_init_once();
317 case SKF_AD_OFF
+ SKF_AD_ALU_XOR_X
:
319 *insn
= BPF_ALU32_REG(BPF_XOR
, BPF_REG_A
, BPF_REG_X
);
323 /* This is just a dummy call to avoid letting the compiler
324 * evict __bpf_call_base() as an optimization. Placed here
325 * where no-one bothers.
327 BUG_ON(__bpf_call_base(0, 0, 0, 0, 0) != 0);
336 * bpf_convert_filter - convert filter program
337 * @prog: the user passed filter program
338 * @len: the length of the user passed filter program
339 * @new_prog: buffer where converted program will be stored
340 * @new_len: pointer to store length of converted program
342 * Remap 'sock_filter' style BPF instruction set to 'sock_filter_ext' style.
343 * Conversion workflow:
345 * 1) First pass for calculating the new program length:
346 * bpf_convert_filter(old_prog, old_len, NULL, &new_len)
348 * 2) 2nd pass to remap in two passes: 1st pass finds new
349 * jump offsets, 2nd pass remapping:
350 * new_prog = kmalloc(sizeof(struct bpf_insn) * new_len);
351 * bpf_convert_filter(old_prog, old_len, new_prog, &new_len);
353 static int bpf_convert_filter(struct sock_filter
*prog
, int len
,
354 struct bpf_insn
*new_prog
, int *new_len
)
356 int new_flen
= 0, pass
= 0, target
, i
;
357 struct bpf_insn
*new_insn
;
358 struct sock_filter
*fp
;
362 BUILD_BUG_ON(BPF_MEMWORDS
* sizeof(u32
) > MAX_BPF_STACK
);
363 BUILD_BUG_ON(BPF_REG_FP
+ 1 != MAX_BPF_REG
);
365 if (len
<= 0 || len
> BPF_MAXINSNS
)
369 addrs
= kcalloc(len
, sizeof(*addrs
),
370 GFP_KERNEL
| __GFP_NOWARN
);
379 /* Classic BPF related prologue emission. */
381 /* Classic BPF expects A and X to be reset first. These need
382 * to be guaranteed to be the first two instructions.
384 *new_insn
++ = BPF_ALU64_REG(BPF_XOR
, BPF_REG_A
, BPF_REG_A
);
385 *new_insn
++ = BPF_ALU64_REG(BPF_XOR
, BPF_REG_X
, BPF_REG_X
);
387 /* All programs must keep CTX in callee saved BPF_REG_CTX.
388 * In eBPF case it's done by the compiler, here we need to
389 * do this ourself. Initial CTX is present in BPF_REG_ARG1.
391 *new_insn
++ = BPF_MOV64_REG(BPF_REG_CTX
, BPF_REG_ARG1
);
396 for (i
= 0; i
< len
; fp
++, i
++) {
397 struct bpf_insn tmp_insns
[6] = { };
398 struct bpf_insn
*insn
= tmp_insns
;
401 addrs
[i
] = new_insn
- new_prog
;
404 /* All arithmetic insns and skb loads map as-is. */
405 case BPF_ALU
| BPF_ADD
| BPF_X
:
406 case BPF_ALU
| BPF_ADD
| BPF_K
:
407 case BPF_ALU
| BPF_SUB
| BPF_X
:
408 case BPF_ALU
| BPF_SUB
| BPF_K
:
409 case BPF_ALU
| BPF_AND
| BPF_X
:
410 case BPF_ALU
| BPF_AND
| BPF_K
:
411 case BPF_ALU
| BPF_OR
| BPF_X
:
412 case BPF_ALU
| BPF_OR
| BPF_K
:
413 case BPF_ALU
| BPF_LSH
| BPF_X
:
414 case BPF_ALU
| BPF_LSH
| BPF_K
:
415 case BPF_ALU
| BPF_RSH
| BPF_X
:
416 case BPF_ALU
| BPF_RSH
| BPF_K
:
417 case BPF_ALU
| BPF_XOR
| BPF_X
:
418 case BPF_ALU
| BPF_XOR
| BPF_K
:
419 case BPF_ALU
| BPF_MUL
| BPF_X
:
420 case BPF_ALU
| BPF_MUL
| BPF_K
:
421 case BPF_ALU
| BPF_DIV
| BPF_X
:
422 case BPF_ALU
| BPF_DIV
| BPF_K
:
423 case BPF_ALU
| BPF_MOD
| BPF_X
:
424 case BPF_ALU
| BPF_MOD
| BPF_K
:
425 case BPF_ALU
| BPF_NEG
:
426 case BPF_LD
| BPF_ABS
| BPF_W
:
427 case BPF_LD
| BPF_ABS
| BPF_H
:
428 case BPF_LD
| BPF_ABS
| BPF_B
:
429 case BPF_LD
| BPF_IND
| BPF_W
:
430 case BPF_LD
| BPF_IND
| BPF_H
:
431 case BPF_LD
| BPF_IND
| BPF_B
:
432 /* Check for overloaded BPF extension and
433 * directly convert it if found, otherwise
434 * just move on with mapping.
436 if (BPF_CLASS(fp
->code
) == BPF_LD
&&
437 BPF_MODE(fp
->code
) == BPF_ABS
&&
438 convert_bpf_extensions(fp
, &insn
))
441 *insn
= BPF_RAW_INSN(fp
->code
, BPF_REG_A
, BPF_REG_X
, 0, fp
->k
);
444 /* Jump transformation cannot use BPF block macros
445 * everywhere as offset calculation and target updates
446 * require a bit more work than the rest, i.e. jump
447 * opcodes map as-is, but offsets need adjustment.
450 #define BPF_EMIT_JMP \
452 if (target >= len || target < 0) \
454 insn->off = addrs ? addrs[target] - addrs[i] - 1 : 0; \
455 /* Adjust pc relative offset for 2nd or 3rd insn. */ \
456 insn->off -= insn - tmp_insns; \
459 case BPF_JMP
| BPF_JA
:
460 target
= i
+ fp
->k
+ 1;
461 insn
->code
= fp
->code
;
465 case BPF_JMP
| BPF_JEQ
| BPF_K
:
466 case BPF_JMP
| BPF_JEQ
| BPF_X
:
467 case BPF_JMP
| BPF_JSET
| BPF_K
:
468 case BPF_JMP
| BPF_JSET
| BPF_X
:
469 case BPF_JMP
| BPF_JGT
| BPF_K
:
470 case BPF_JMP
| BPF_JGT
| BPF_X
:
471 case BPF_JMP
| BPF_JGE
| BPF_K
:
472 case BPF_JMP
| BPF_JGE
| BPF_X
:
473 if (BPF_SRC(fp
->code
) == BPF_K
&& (int) fp
->k
< 0) {
474 /* BPF immediates are signed, zero extend
475 * immediate into tmp register and use it
478 *insn
++ = BPF_MOV32_IMM(BPF_REG_TMP
, fp
->k
);
480 insn
->dst_reg
= BPF_REG_A
;
481 insn
->src_reg
= BPF_REG_TMP
;
484 insn
->dst_reg
= BPF_REG_A
;
486 bpf_src
= BPF_SRC(fp
->code
);
487 insn
->src_reg
= bpf_src
== BPF_X
? BPF_REG_X
: 0;
490 /* Common case where 'jump_false' is next insn. */
492 insn
->code
= BPF_JMP
| BPF_OP(fp
->code
) | bpf_src
;
493 target
= i
+ fp
->jt
+ 1;
498 /* Convert JEQ into JNE when 'jump_true' is next insn. */
499 if (fp
->jt
== 0 && BPF_OP(fp
->code
) == BPF_JEQ
) {
500 insn
->code
= BPF_JMP
| BPF_JNE
| bpf_src
;
501 target
= i
+ fp
->jf
+ 1;
506 /* Other jumps are mapped into two insns: Jxx and JA. */
507 target
= i
+ fp
->jt
+ 1;
508 insn
->code
= BPF_JMP
| BPF_OP(fp
->code
) | bpf_src
;
512 insn
->code
= BPF_JMP
| BPF_JA
;
513 target
= i
+ fp
->jf
+ 1;
517 /* ldxb 4 * ([14] & 0xf) is remaped into 6 insns. */
518 case BPF_LDX
| BPF_MSH
| BPF_B
:
520 *insn
++ = BPF_MOV64_REG(BPF_REG_TMP
, BPF_REG_A
);
521 /* A = BPF_R0 = *(u8 *) (skb->data + K) */
522 *insn
++ = BPF_LD_ABS(BPF_B
, fp
->k
);
524 *insn
++ = BPF_ALU32_IMM(BPF_AND
, BPF_REG_A
, 0xf);
526 *insn
++ = BPF_ALU32_IMM(BPF_LSH
, BPF_REG_A
, 2);
528 *insn
++ = BPF_MOV64_REG(BPF_REG_X
, BPF_REG_A
);
530 *insn
= BPF_MOV64_REG(BPF_REG_A
, BPF_REG_TMP
);
533 /* RET_K is remaped into 2 insns. RET_A case doesn't need an
534 * extra mov as BPF_REG_0 is already mapped into BPF_REG_A.
536 case BPF_RET
| BPF_A
:
537 case BPF_RET
| BPF_K
:
538 if (BPF_RVAL(fp
->code
) == BPF_K
)
539 *insn
++ = BPF_MOV32_RAW(BPF_K
, BPF_REG_0
,
541 *insn
= BPF_EXIT_INSN();
544 /* Store to stack. */
547 *insn
= BPF_STX_MEM(BPF_W
, BPF_REG_FP
, BPF_CLASS(fp
->code
) ==
548 BPF_ST
? BPF_REG_A
: BPF_REG_X
,
549 -(BPF_MEMWORDS
- fp
->k
) * 4);
552 /* Load from stack. */
553 case BPF_LD
| BPF_MEM
:
554 case BPF_LDX
| BPF_MEM
:
555 *insn
= BPF_LDX_MEM(BPF_W
, BPF_CLASS(fp
->code
) == BPF_LD
?
556 BPF_REG_A
: BPF_REG_X
, BPF_REG_FP
,
557 -(BPF_MEMWORDS
- fp
->k
) * 4);
561 case BPF_LD
| BPF_IMM
:
562 case BPF_LDX
| BPF_IMM
:
563 *insn
= BPF_MOV32_IMM(BPF_CLASS(fp
->code
) == BPF_LD
?
564 BPF_REG_A
: BPF_REG_X
, fp
->k
);
568 case BPF_MISC
| BPF_TAX
:
569 *insn
= BPF_MOV64_REG(BPF_REG_X
, BPF_REG_A
);
573 case BPF_MISC
| BPF_TXA
:
574 *insn
= BPF_MOV64_REG(BPF_REG_A
, BPF_REG_X
);
577 /* A = skb->len or X = skb->len */
578 case BPF_LD
| BPF_W
| BPF_LEN
:
579 case BPF_LDX
| BPF_W
| BPF_LEN
:
580 *insn
= BPF_LDX_MEM(BPF_W
, BPF_CLASS(fp
->code
) == BPF_LD
?
581 BPF_REG_A
: BPF_REG_X
, BPF_REG_CTX
,
582 offsetof(struct sk_buff
, len
));
585 /* Access seccomp_data fields. */
586 case BPF_LDX
| BPF_ABS
| BPF_W
:
587 /* A = *(u32 *) (ctx + K) */
588 *insn
= BPF_LDX_MEM(BPF_W
, BPF_REG_A
, BPF_REG_CTX
, fp
->k
);
591 /* Unknown instruction. */
598 memcpy(new_insn
, tmp_insns
,
599 sizeof(*insn
) * (insn
- tmp_insns
));
600 new_insn
+= insn
- tmp_insns
;
604 /* Only calculating new length. */
605 *new_len
= new_insn
- new_prog
;
610 if (new_flen
!= new_insn
- new_prog
) {
611 new_flen
= new_insn
- new_prog
;
618 BUG_ON(*new_len
!= new_flen
);
627 * As we dont want to clear mem[] array for each packet going through
628 * __bpf_prog_run(), we check that filter loaded by user never try to read
629 * a cell if not previously written, and we check all branches to be sure
630 * a malicious user doesn't try to abuse us.
632 static int check_load_and_stores(const struct sock_filter
*filter
, int flen
)
634 u16
*masks
, memvalid
= 0; /* One bit per cell, 16 cells */
637 BUILD_BUG_ON(BPF_MEMWORDS
> 16);
639 masks
= kmalloc_array(flen
, sizeof(*masks
), GFP_KERNEL
);
643 memset(masks
, 0xff, flen
* sizeof(*masks
));
645 for (pc
= 0; pc
< flen
; pc
++) {
646 memvalid
&= masks
[pc
];
648 switch (filter
[pc
].code
) {
651 memvalid
|= (1 << filter
[pc
].k
);
653 case BPF_LD
| BPF_MEM
:
654 case BPF_LDX
| BPF_MEM
:
655 if (!(memvalid
& (1 << filter
[pc
].k
))) {
660 case BPF_JMP
| BPF_JA
:
661 /* A jump must set masks on target */
662 masks
[pc
+ 1 + filter
[pc
].k
] &= memvalid
;
665 case BPF_JMP
| BPF_JEQ
| BPF_K
:
666 case BPF_JMP
| BPF_JEQ
| BPF_X
:
667 case BPF_JMP
| BPF_JGE
| BPF_K
:
668 case BPF_JMP
| BPF_JGE
| BPF_X
:
669 case BPF_JMP
| BPF_JGT
| BPF_K
:
670 case BPF_JMP
| BPF_JGT
| BPF_X
:
671 case BPF_JMP
| BPF_JSET
| BPF_K
:
672 case BPF_JMP
| BPF_JSET
| BPF_X
:
673 /* A jump must set masks on targets */
674 masks
[pc
+ 1 + filter
[pc
].jt
] &= memvalid
;
675 masks
[pc
+ 1 + filter
[pc
].jf
] &= memvalid
;
685 static bool chk_code_allowed(u16 code_to_probe
)
687 static const bool codes
[] = {
688 /* 32 bit ALU operations */
689 [BPF_ALU
| BPF_ADD
| BPF_K
] = true,
690 [BPF_ALU
| BPF_ADD
| BPF_X
] = true,
691 [BPF_ALU
| BPF_SUB
| BPF_K
] = true,
692 [BPF_ALU
| BPF_SUB
| BPF_X
] = true,
693 [BPF_ALU
| BPF_MUL
| BPF_K
] = true,
694 [BPF_ALU
| BPF_MUL
| BPF_X
] = true,
695 [BPF_ALU
| BPF_DIV
| BPF_K
] = true,
696 [BPF_ALU
| BPF_DIV
| BPF_X
] = true,
697 [BPF_ALU
| BPF_MOD
| BPF_K
] = true,
698 [BPF_ALU
| BPF_MOD
| BPF_X
] = true,
699 [BPF_ALU
| BPF_AND
| BPF_K
] = true,
700 [BPF_ALU
| BPF_AND
| BPF_X
] = true,
701 [BPF_ALU
| BPF_OR
| BPF_K
] = true,
702 [BPF_ALU
| BPF_OR
| BPF_X
] = true,
703 [BPF_ALU
| BPF_XOR
| BPF_K
] = true,
704 [BPF_ALU
| BPF_XOR
| BPF_X
] = true,
705 [BPF_ALU
| BPF_LSH
| BPF_K
] = true,
706 [BPF_ALU
| BPF_LSH
| BPF_X
] = true,
707 [BPF_ALU
| BPF_RSH
| BPF_K
] = true,
708 [BPF_ALU
| BPF_RSH
| BPF_X
] = true,
709 [BPF_ALU
| BPF_NEG
] = true,
710 /* Load instructions */
711 [BPF_LD
| BPF_W
| BPF_ABS
] = true,
712 [BPF_LD
| BPF_H
| BPF_ABS
] = true,
713 [BPF_LD
| BPF_B
| BPF_ABS
] = true,
714 [BPF_LD
| BPF_W
| BPF_LEN
] = true,
715 [BPF_LD
| BPF_W
| BPF_IND
] = true,
716 [BPF_LD
| BPF_H
| BPF_IND
] = true,
717 [BPF_LD
| BPF_B
| BPF_IND
] = true,
718 [BPF_LD
| BPF_IMM
] = true,
719 [BPF_LD
| BPF_MEM
] = true,
720 [BPF_LDX
| BPF_W
| BPF_LEN
] = true,
721 [BPF_LDX
| BPF_B
| BPF_MSH
] = true,
722 [BPF_LDX
| BPF_IMM
] = true,
723 [BPF_LDX
| BPF_MEM
] = true,
724 /* Store instructions */
727 /* Misc instructions */
728 [BPF_MISC
| BPF_TAX
] = true,
729 [BPF_MISC
| BPF_TXA
] = true,
730 /* Return instructions */
731 [BPF_RET
| BPF_K
] = true,
732 [BPF_RET
| BPF_A
] = true,
733 /* Jump instructions */
734 [BPF_JMP
| BPF_JA
] = true,
735 [BPF_JMP
| BPF_JEQ
| BPF_K
] = true,
736 [BPF_JMP
| BPF_JEQ
| BPF_X
] = true,
737 [BPF_JMP
| BPF_JGE
| BPF_K
] = true,
738 [BPF_JMP
| BPF_JGE
| BPF_X
] = true,
739 [BPF_JMP
| BPF_JGT
| BPF_K
] = true,
740 [BPF_JMP
| BPF_JGT
| BPF_X
] = true,
741 [BPF_JMP
| BPF_JSET
| BPF_K
] = true,
742 [BPF_JMP
| BPF_JSET
| BPF_X
] = true,
745 if (code_to_probe
>= ARRAY_SIZE(codes
))
748 return codes
[code_to_probe
];
752 * bpf_check_classic - verify socket filter code
753 * @filter: filter to verify
754 * @flen: length of filter
756 * Check the user's filter code. If we let some ugly
757 * filter code slip through kaboom! The filter must contain
758 * no references or jumps that are out of range, no illegal
759 * instructions, and must end with a RET instruction.
761 * All jumps are forward as they are not signed.
763 * Returns 0 if the rule set is legal or -EINVAL if not.
765 static int bpf_check_classic(const struct sock_filter
*filter
,
771 if (flen
== 0 || flen
> BPF_MAXINSNS
)
774 /* Check the filter code now */
775 for (pc
= 0; pc
< flen
; pc
++) {
776 const struct sock_filter
*ftest
= &filter
[pc
];
778 /* May we actually operate on this code? */
779 if (!chk_code_allowed(ftest
->code
))
782 /* Some instructions need special checks */
783 switch (ftest
->code
) {
784 case BPF_ALU
| BPF_DIV
| BPF_K
:
785 case BPF_ALU
| BPF_MOD
| BPF_K
:
786 /* Check for division by zero */
790 case BPF_ALU
| BPF_LSH
| BPF_K
:
791 case BPF_ALU
| BPF_RSH
| BPF_K
:
795 case BPF_LD
| BPF_MEM
:
796 case BPF_LDX
| BPF_MEM
:
799 /* Check for invalid memory addresses */
800 if (ftest
->k
>= BPF_MEMWORDS
)
803 case BPF_JMP
| BPF_JA
:
804 /* Note, the large ftest->k might cause loops.
805 * Compare this with conditional jumps below,
806 * where offsets are limited. --ANK (981016)
808 if (ftest
->k
>= (unsigned int)(flen
- pc
- 1))
811 case BPF_JMP
| BPF_JEQ
| BPF_K
:
812 case BPF_JMP
| BPF_JEQ
| BPF_X
:
813 case BPF_JMP
| BPF_JGE
| BPF_K
:
814 case BPF_JMP
| BPF_JGE
| BPF_X
:
815 case BPF_JMP
| BPF_JGT
| BPF_K
:
816 case BPF_JMP
| BPF_JGT
| BPF_X
:
817 case BPF_JMP
| BPF_JSET
| BPF_K
:
818 case BPF_JMP
| BPF_JSET
| BPF_X
:
819 /* Both conditionals must be safe */
820 if (pc
+ ftest
->jt
+ 1 >= flen
||
821 pc
+ ftest
->jf
+ 1 >= flen
)
824 case BPF_LD
| BPF_W
| BPF_ABS
:
825 case BPF_LD
| BPF_H
| BPF_ABS
:
826 case BPF_LD
| BPF_B
| BPF_ABS
:
828 if (bpf_anc_helper(ftest
) & BPF_ANC
)
830 /* Ancillary operation unknown or unsupported */
831 if (anc_found
== false && ftest
->k
>= SKF_AD_OFF
)
836 /* Last instruction must be a RET code */
837 switch (filter
[flen
- 1].code
) {
838 case BPF_RET
| BPF_K
:
839 case BPF_RET
| BPF_A
:
840 return check_load_and_stores(filter
, flen
);
846 static int bpf_prog_store_orig_filter(struct bpf_prog
*fp
,
847 const struct sock_fprog
*fprog
)
849 unsigned int fsize
= bpf_classic_proglen(fprog
);
850 struct sock_fprog_kern
*fkprog
;
852 fp
->orig_prog
= kmalloc(sizeof(*fkprog
), GFP_KERNEL
);
856 fkprog
= fp
->orig_prog
;
857 fkprog
->len
= fprog
->len
;
859 fkprog
->filter
= kmemdup(fp
->insns
, fsize
,
860 GFP_KERNEL
| __GFP_NOWARN
);
861 if (!fkprog
->filter
) {
862 kfree(fp
->orig_prog
);
869 static void bpf_release_orig_filter(struct bpf_prog
*fp
)
871 struct sock_fprog_kern
*fprog
= fp
->orig_prog
;
874 kfree(fprog
->filter
);
879 static void __bpf_prog_release(struct bpf_prog
*prog
)
881 if (prog
->type
== BPF_PROG_TYPE_SOCKET_FILTER
) {
884 bpf_release_orig_filter(prog
);
889 static void __sk_filter_release(struct sk_filter
*fp
)
891 __bpf_prog_release(fp
->prog
);
896 * sk_filter_release_rcu - Release a socket filter by rcu_head
897 * @rcu: rcu_head that contains the sk_filter to free
899 static void sk_filter_release_rcu(struct rcu_head
*rcu
)
901 struct sk_filter
*fp
= container_of(rcu
, struct sk_filter
, rcu
);
903 __sk_filter_release(fp
);
907 * sk_filter_release - release a socket filter
908 * @fp: filter to remove
910 * Remove a filter from a socket and release its resources.
912 static void sk_filter_release(struct sk_filter
*fp
)
914 if (atomic_dec_and_test(&fp
->refcnt
))
915 call_rcu(&fp
->rcu
, sk_filter_release_rcu
);
918 void sk_filter_uncharge(struct sock
*sk
, struct sk_filter
*fp
)
920 u32 filter_size
= bpf_prog_size(fp
->prog
->len
);
922 atomic_sub(filter_size
, &sk
->sk_omem_alloc
);
923 sk_filter_release(fp
);
926 /* try to charge the socket memory if there is space available
927 * return true on success
929 bool sk_filter_charge(struct sock
*sk
, struct sk_filter
*fp
)
931 u32 filter_size
= bpf_prog_size(fp
->prog
->len
);
933 /* same check as in sock_kmalloc() */
934 if (filter_size
<= sysctl_optmem_max
&&
935 atomic_read(&sk
->sk_omem_alloc
) + filter_size
< sysctl_optmem_max
) {
936 atomic_inc(&fp
->refcnt
);
937 atomic_add(filter_size
, &sk
->sk_omem_alloc
);
943 static struct bpf_prog
*bpf_migrate_filter(struct bpf_prog
*fp
)
945 struct sock_filter
*old_prog
;
946 struct bpf_prog
*old_fp
;
947 int err
, new_len
, old_len
= fp
->len
;
949 /* We are free to overwrite insns et al right here as it
950 * won't be used at this point in time anymore internally
951 * after the migration to the internal BPF instruction
954 BUILD_BUG_ON(sizeof(struct sock_filter
) !=
955 sizeof(struct bpf_insn
));
957 /* Conversion cannot happen on overlapping memory areas,
958 * so we need to keep the user BPF around until the 2nd
959 * pass. At this time, the user BPF is stored in fp->insns.
961 old_prog
= kmemdup(fp
->insns
, old_len
* sizeof(struct sock_filter
),
962 GFP_KERNEL
| __GFP_NOWARN
);
968 /* 1st pass: calculate the new program length. */
969 err
= bpf_convert_filter(old_prog
, old_len
, NULL
, &new_len
);
973 /* Expand fp for appending the new filter representation. */
975 fp
= bpf_prog_realloc(old_fp
, bpf_prog_size(new_len
), 0);
977 /* The old_fp is still around in case we couldn't
978 * allocate new memory, so uncharge on that one.
987 /* 2nd pass: remap sock_filter insns into bpf_insn insns. */
988 err
= bpf_convert_filter(old_prog
, old_len
, fp
->insnsi
, &new_len
);
990 /* 2nd bpf_convert_filter() can fail only if it fails
991 * to allocate memory, remapping must succeed. Note,
992 * that at this time old_fp has already been released
997 /* We are guaranteed to never error here with cBPF to eBPF
998 * transitions, since there's no issue with type compatibility
999 * checks on program arrays.
1001 fp
= bpf_prog_select_runtime(fp
, &err
);
1009 __bpf_prog_release(fp
);
1010 return ERR_PTR(err
);
1013 static struct bpf_prog
*bpf_prepare_filter(struct bpf_prog
*fp
,
1014 bpf_aux_classic_check_t trans
)
1018 fp
->bpf_func
= NULL
;
1021 err
= bpf_check_classic(fp
->insns
, fp
->len
);
1023 __bpf_prog_release(fp
);
1024 return ERR_PTR(err
);
1027 /* There might be additional checks and transformations
1028 * needed on classic filters, f.e. in case of seccomp.
1031 err
= trans(fp
->insns
, fp
->len
);
1033 __bpf_prog_release(fp
);
1034 return ERR_PTR(err
);
1038 /* Probe if we can JIT compile the filter and if so, do
1039 * the compilation of the filter.
1041 bpf_jit_compile(fp
);
1043 /* JIT compiler couldn't process this filter, so do the
1044 * internal BPF translation for the optimized interpreter.
1047 fp
= bpf_migrate_filter(fp
);
1053 * bpf_prog_create - create an unattached filter
1054 * @pfp: the unattached filter that is created
1055 * @fprog: the filter program
1057 * Create a filter independent of any socket. We first run some
1058 * sanity checks on it to make sure it does not explode on us later.
1059 * If an error occurs or there is insufficient memory for the filter
1060 * a negative errno code is returned. On success the return is zero.
1062 int bpf_prog_create(struct bpf_prog
**pfp
, struct sock_fprog_kern
*fprog
)
1064 unsigned int fsize
= bpf_classic_proglen(fprog
);
1065 struct bpf_prog
*fp
;
1067 /* Make sure new filter is there and in the right amounts. */
1068 if (fprog
->filter
== NULL
)
1071 fp
= bpf_prog_alloc(bpf_prog_size(fprog
->len
), 0);
1075 memcpy(fp
->insns
, fprog
->filter
, fsize
);
1077 fp
->len
= fprog
->len
;
1078 /* Since unattached filters are not copied back to user
1079 * space through sk_get_filter(), we do not need to hold
1080 * a copy here, and can spare us the work.
1082 fp
->orig_prog
= NULL
;
1084 /* bpf_prepare_filter() already takes care of freeing
1085 * memory in case something goes wrong.
1087 fp
= bpf_prepare_filter(fp
, NULL
);
1094 EXPORT_SYMBOL_GPL(bpf_prog_create
);
1097 * bpf_prog_create_from_user - create an unattached filter from user buffer
1098 * @pfp: the unattached filter that is created
1099 * @fprog: the filter program
1100 * @trans: post-classic verifier transformation handler
1101 * @save_orig: save classic BPF program
1103 * This function effectively does the same as bpf_prog_create(), only
1104 * that it builds up its insns buffer from user space provided buffer.
1105 * It also allows for passing a bpf_aux_classic_check_t handler.
1107 int bpf_prog_create_from_user(struct bpf_prog
**pfp
, struct sock_fprog
*fprog
,
1108 bpf_aux_classic_check_t trans
, bool save_orig
)
1110 unsigned int fsize
= bpf_classic_proglen(fprog
);
1111 struct bpf_prog
*fp
;
1114 /* Make sure new filter is there and in the right amounts. */
1115 if (fprog
->filter
== NULL
)
1118 fp
= bpf_prog_alloc(bpf_prog_size(fprog
->len
), 0);
1122 if (copy_from_user(fp
->insns
, fprog
->filter
, fsize
)) {
1123 __bpf_prog_free(fp
);
1127 fp
->len
= fprog
->len
;
1128 fp
->orig_prog
= NULL
;
1131 err
= bpf_prog_store_orig_filter(fp
, fprog
);
1133 __bpf_prog_free(fp
);
1138 /* bpf_prepare_filter() already takes care of freeing
1139 * memory in case something goes wrong.
1141 fp
= bpf_prepare_filter(fp
, trans
);
1148 EXPORT_SYMBOL_GPL(bpf_prog_create_from_user
);
1150 void bpf_prog_destroy(struct bpf_prog
*fp
)
1152 __bpf_prog_release(fp
);
1154 EXPORT_SYMBOL_GPL(bpf_prog_destroy
);
1156 static int __sk_attach_prog(struct bpf_prog
*prog
, struct sock
*sk
)
1158 struct sk_filter
*fp
, *old_fp
;
1160 fp
= kmalloc(sizeof(*fp
), GFP_KERNEL
);
1165 atomic_set(&fp
->refcnt
, 0);
1167 if (!sk_filter_charge(sk
, fp
)) {
1172 old_fp
= rcu_dereference_protected(sk
->sk_filter
,
1173 lockdep_sock_is_held(sk
));
1174 rcu_assign_pointer(sk
->sk_filter
, fp
);
1177 sk_filter_uncharge(sk
, old_fp
);
1182 static int __reuseport_attach_prog(struct bpf_prog
*prog
, struct sock
*sk
)
1184 struct bpf_prog
*old_prog
;
1187 if (bpf_prog_size(prog
->len
) > sysctl_optmem_max
)
1190 if (sk_unhashed(sk
) && sk
->sk_reuseport
) {
1191 err
= reuseport_alloc(sk
);
1194 } else if (!rcu_access_pointer(sk
->sk_reuseport_cb
)) {
1195 /* The socket wasn't bound with SO_REUSEPORT */
1199 old_prog
= reuseport_attach_prog(sk
, prog
);
1201 bpf_prog_destroy(old_prog
);
1207 struct bpf_prog
*__get_filter(struct sock_fprog
*fprog
, struct sock
*sk
)
1209 unsigned int fsize
= bpf_classic_proglen(fprog
);
1210 unsigned int bpf_fsize
= bpf_prog_size(fprog
->len
);
1211 struct bpf_prog
*prog
;
1214 if (sock_flag(sk
, SOCK_FILTER_LOCKED
))
1215 return ERR_PTR(-EPERM
);
1217 /* Make sure new filter is there and in the right amounts. */
1218 if (fprog
->filter
== NULL
)
1219 return ERR_PTR(-EINVAL
);
1221 prog
= bpf_prog_alloc(bpf_fsize
, 0);
1223 return ERR_PTR(-ENOMEM
);
1225 if (copy_from_user(prog
->insns
, fprog
->filter
, fsize
)) {
1226 __bpf_prog_free(prog
);
1227 return ERR_PTR(-EFAULT
);
1230 prog
->len
= fprog
->len
;
1232 err
= bpf_prog_store_orig_filter(prog
, fprog
);
1234 __bpf_prog_free(prog
);
1235 return ERR_PTR(-ENOMEM
);
1238 /* bpf_prepare_filter() already takes care of freeing
1239 * memory in case something goes wrong.
1241 return bpf_prepare_filter(prog
, NULL
);
1245 * sk_attach_filter - attach a socket filter
1246 * @fprog: the filter program
1247 * @sk: the socket to use
1249 * Attach the user's filter code. We first run some sanity checks on
1250 * it to make sure it does not explode on us later. If an error
1251 * occurs or there is insufficient memory for the filter a negative
1252 * errno code is returned. On success the return is zero.
1254 int sk_attach_filter(struct sock_fprog
*fprog
, struct sock
*sk
)
1256 struct bpf_prog
*prog
= __get_filter(fprog
, sk
);
1260 return PTR_ERR(prog
);
1262 err
= __sk_attach_prog(prog
, sk
);
1264 __bpf_prog_release(prog
);
1270 EXPORT_SYMBOL_GPL(sk_attach_filter
);
1272 int sk_reuseport_attach_filter(struct sock_fprog
*fprog
, struct sock
*sk
)
1274 struct bpf_prog
*prog
= __get_filter(fprog
, sk
);
1278 return PTR_ERR(prog
);
1280 err
= __reuseport_attach_prog(prog
, sk
);
1282 __bpf_prog_release(prog
);
1289 static struct bpf_prog
*__get_bpf(u32 ufd
, struct sock
*sk
)
1291 struct bpf_prog
*prog
;
1293 if (sock_flag(sk
, SOCK_FILTER_LOCKED
))
1294 return ERR_PTR(-EPERM
);
1296 prog
= bpf_prog_get(ufd
);
1300 if (prog
->type
!= BPF_PROG_TYPE_SOCKET_FILTER
) {
1302 return ERR_PTR(-EINVAL
);
1308 int sk_attach_bpf(u32 ufd
, struct sock
*sk
)
1310 struct bpf_prog
*prog
= __get_bpf(ufd
, sk
);
1314 return PTR_ERR(prog
);
1316 err
= __sk_attach_prog(prog
, sk
);
1325 int sk_reuseport_attach_bpf(u32 ufd
, struct sock
*sk
)
1327 struct bpf_prog
*prog
= __get_bpf(ufd
, sk
);
1331 return PTR_ERR(prog
);
1333 err
= __reuseport_attach_prog(prog
, sk
);
1342 struct bpf_scratchpad
{
1344 __be32 diff
[MAX_BPF_STACK
/ sizeof(__be32
)];
1345 u8 buff
[MAX_BPF_STACK
];
1349 static DEFINE_PER_CPU(struct bpf_scratchpad
, bpf_sp
);
1351 static inline int bpf_try_make_writable(struct sk_buff
*skb
,
1352 unsigned int write_len
)
1356 if (!skb_cloned(skb
))
1358 if (skb_clone_writable(skb
, write_len
))
1360 err
= pskb_expand_head(skb
, 0, 0, GFP_ATOMIC
);
1362 bpf_compute_data_end(skb
);
1366 static u64
bpf_skb_store_bytes(u64 r1
, u64 r2
, u64 r3
, u64 r4
, u64 flags
)
1368 struct bpf_scratchpad
*sp
= this_cpu_ptr(&bpf_sp
);
1369 struct sk_buff
*skb
= (struct sk_buff
*) (long) r1
;
1370 int offset
= (int) r2
;
1371 void *from
= (void *) (long) r3
;
1372 unsigned int len
= (unsigned int) r4
;
1375 if (unlikely(flags
& ~(BPF_F_RECOMPUTE_CSUM
| BPF_F_INVALIDATE_HASH
)))
1378 /* bpf verifier guarantees that:
1379 * 'from' pointer points to bpf program stack
1380 * 'len' bytes of it were initialized
1382 * 'skb' is a valid pointer to 'struct sk_buff'
1384 * so check for invalid 'offset' and too large 'len'
1386 if (unlikely((u32
) offset
> 0xffff || len
> sizeof(sp
->buff
)))
1388 if (unlikely(bpf_try_make_writable(skb
, offset
+ len
)))
1391 ptr
= skb_header_pointer(skb
, offset
, len
, sp
->buff
);
1395 if (flags
& BPF_F_RECOMPUTE_CSUM
)
1396 skb_postpull_rcsum(skb
, ptr
, len
);
1398 memcpy(ptr
, from
, len
);
1400 if (ptr
== sp
->buff
)
1401 /* skb_store_bits cannot return -EFAULT here */
1402 skb_store_bits(skb
, offset
, ptr
, len
);
1404 if (flags
& BPF_F_RECOMPUTE_CSUM
)
1405 skb_postpush_rcsum(skb
, ptr
, len
);
1406 if (flags
& BPF_F_INVALIDATE_HASH
)
1407 skb_clear_hash(skb
);
1412 static const struct bpf_func_proto bpf_skb_store_bytes_proto
= {
1413 .func
= bpf_skb_store_bytes
,
1415 .ret_type
= RET_INTEGER
,
1416 .arg1_type
= ARG_PTR_TO_CTX
,
1417 .arg2_type
= ARG_ANYTHING
,
1418 .arg3_type
= ARG_PTR_TO_STACK
,
1419 .arg4_type
= ARG_CONST_STACK_SIZE
,
1420 .arg5_type
= ARG_ANYTHING
,
1423 static u64
bpf_skb_load_bytes(u64 r1
, u64 r2
, u64 r3
, u64 r4
, u64 r5
)
1425 const struct sk_buff
*skb
= (const struct sk_buff
*)(unsigned long) r1
;
1426 int offset
= (int) r2
;
1427 void *to
= (void *)(unsigned long) r3
;
1428 unsigned int len
= (unsigned int) r4
;
1431 if (unlikely((u32
) offset
> 0xffff))
1434 ptr
= skb_header_pointer(skb
, offset
, len
, to
);
1438 memcpy(to
, ptr
, len
);
1446 static const struct bpf_func_proto bpf_skb_load_bytes_proto
= {
1447 .func
= bpf_skb_load_bytes
,
1449 .ret_type
= RET_INTEGER
,
1450 .arg1_type
= ARG_PTR_TO_CTX
,
1451 .arg2_type
= ARG_ANYTHING
,
1452 .arg3_type
= ARG_PTR_TO_RAW_STACK
,
1453 .arg4_type
= ARG_CONST_STACK_SIZE
,
1456 static u64
bpf_l3_csum_replace(u64 r1
, u64 r2
, u64 from
, u64 to
, u64 flags
)
1458 struct sk_buff
*skb
= (struct sk_buff
*) (long) r1
;
1459 int offset
= (int) r2
;
1462 if (unlikely(flags
& ~(BPF_F_HDR_FIELD_MASK
)))
1464 if (unlikely((u32
) offset
> 0xffff))
1466 if (unlikely(bpf_try_make_writable(skb
, offset
+ sizeof(sum
))))
1469 ptr
= skb_header_pointer(skb
, offset
, sizeof(sum
), &sum
);
1473 switch (flags
& BPF_F_HDR_FIELD_MASK
) {
1475 if (unlikely(from
!= 0))
1478 csum_replace_by_diff(ptr
, to
);
1481 csum_replace2(ptr
, from
, to
);
1484 csum_replace4(ptr
, from
, to
);
1491 /* skb_store_bits guaranteed to not return -EFAULT here */
1492 skb_store_bits(skb
, offset
, ptr
, sizeof(sum
));
1497 static const struct bpf_func_proto bpf_l3_csum_replace_proto
= {
1498 .func
= bpf_l3_csum_replace
,
1500 .ret_type
= RET_INTEGER
,
1501 .arg1_type
= ARG_PTR_TO_CTX
,
1502 .arg2_type
= ARG_ANYTHING
,
1503 .arg3_type
= ARG_ANYTHING
,
1504 .arg4_type
= ARG_ANYTHING
,
1505 .arg5_type
= ARG_ANYTHING
,
1508 static u64
bpf_l4_csum_replace(u64 r1
, u64 r2
, u64 from
, u64 to
, u64 flags
)
1510 struct sk_buff
*skb
= (struct sk_buff
*) (long) r1
;
1511 bool is_pseudo
= flags
& BPF_F_PSEUDO_HDR
;
1512 bool is_mmzero
= flags
& BPF_F_MARK_MANGLED_0
;
1513 int offset
= (int) r2
;
1516 if (unlikely(flags
& ~(BPF_F_MARK_MANGLED_0
| BPF_F_PSEUDO_HDR
|
1517 BPF_F_HDR_FIELD_MASK
)))
1519 if (unlikely((u32
) offset
> 0xffff))
1521 if (unlikely(bpf_try_make_writable(skb
, offset
+ sizeof(sum
))))
1524 ptr
= skb_header_pointer(skb
, offset
, sizeof(sum
), &sum
);
1527 if (is_mmzero
&& !*ptr
)
1530 switch (flags
& BPF_F_HDR_FIELD_MASK
) {
1532 if (unlikely(from
!= 0))
1535 inet_proto_csum_replace_by_diff(ptr
, skb
, to
, is_pseudo
);
1538 inet_proto_csum_replace2(ptr
, skb
, from
, to
, is_pseudo
);
1541 inet_proto_csum_replace4(ptr
, skb
, from
, to
, is_pseudo
);
1547 if (is_mmzero
&& !*ptr
)
1548 *ptr
= CSUM_MANGLED_0
;
1550 /* skb_store_bits guaranteed to not return -EFAULT here */
1551 skb_store_bits(skb
, offset
, ptr
, sizeof(sum
));
1556 static const struct bpf_func_proto bpf_l4_csum_replace_proto
= {
1557 .func
= bpf_l4_csum_replace
,
1559 .ret_type
= RET_INTEGER
,
1560 .arg1_type
= ARG_PTR_TO_CTX
,
1561 .arg2_type
= ARG_ANYTHING
,
1562 .arg3_type
= ARG_ANYTHING
,
1563 .arg4_type
= ARG_ANYTHING
,
1564 .arg5_type
= ARG_ANYTHING
,
1567 static u64
bpf_csum_diff(u64 r1
, u64 from_size
, u64 r3
, u64 to_size
, u64 seed
)
1569 struct bpf_scratchpad
*sp
= this_cpu_ptr(&bpf_sp
);
1570 u64 diff_size
= from_size
+ to_size
;
1571 __be32
*from
= (__be32
*) (long) r1
;
1572 __be32
*to
= (__be32
*) (long) r3
;
1575 /* This is quite flexible, some examples:
1577 * from_size == 0, to_size > 0, seed := csum --> pushing data
1578 * from_size > 0, to_size == 0, seed := csum --> pulling data
1579 * from_size > 0, to_size > 0, seed := 0 --> diffing data
1581 * Even for diffing, from_size and to_size don't need to be equal.
1583 if (unlikely(((from_size
| to_size
) & (sizeof(__be32
) - 1)) ||
1584 diff_size
> sizeof(sp
->diff
)))
1587 for (i
= 0; i
< from_size
/ sizeof(__be32
); i
++, j
++)
1588 sp
->diff
[j
] = ~from
[i
];
1589 for (i
= 0; i
< to_size
/ sizeof(__be32
); i
++, j
++)
1590 sp
->diff
[j
] = to
[i
];
1592 return csum_partial(sp
->diff
, diff_size
, seed
);
1595 static const struct bpf_func_proto bpf_csum_diff_proto
= {
1596 .func
= bpf_csum_diff
,
1598 .ret_type
= RET_INTEGER
,
1599 .arg1_type
= ARG_PTR_TO_STACK
,
1600 .arg2_type
= ARG_CONST_STACK_SIZE_OR_ZERO
,
1601 .arg3_type
= ARG_PTR_TO_STACK
,
1602 .arg4_type
= ARG_CONST_STACK_SIZE_OR_ZERO
,
1603 .arg5_type
= ARG_ANYTHING
,
1606 static u64
bpf_clone_redirect(u64 r1
, u64 ifindex
, u64 flags
, u64 r4
, u64 r5
)
1608 struct sk_buff
*skb
= (struct sk_buff
*) (long) r1
, *skb2
;
1609 struct net_device
*dev
;
1611 if (unlikely(flags
& ~(BPF_F_INGRESS
)))
1614 dev
= dev_get_by_index_rcu(dev_net(skb
->dev
), ifindex
);
1618 skb2
= skb_clone(skb
, GFP_ATOMIC
);
1619 if (unlikely(!skb2
))
1622 if (flags
& BPF_F_INGRESS
) {
1623 if (skb_at_tc_ingress(skb2
))
1624 skb_postpush_rcsum(skb2
, skb_mac_header(skb2
),
1626 return dev_forward_skb(dev
, skb2
);
1630 return dev_queue_xmit(skb2
);
1633 static const struct bpf_func_proto bpf_clone_redirect_proto
= {
1634 .func
= bpf_clone_redirect
,
1636 .ret_type
= RET_INTEGER
,
1637 .arg1_type
= ARG_PTR_TO_CTX
,
1638 .arg2_type
= ARG_ANYTHING
,
1639 .arg3_type
= ARG_ANYTHING
,
1642 struct redirect_info
{
1647 static DEFINE_PER_CPU(struct redirect_info
, redirect_info
);
1649 static u64
bpf_redirect(u64 ifindex
, u64 flags
, u64 r3
, u64 r4
, u64 r5
)
1651 struct redirect_info
*ri
= this_cpu_ptr(&redirect_info
);
1653 if (unlikely(flags
& ~(BPF_F_INGRESS
)))
1656 ri
->ifindex
= ifindex
;
1659 return TC_ACT_REDIRECT
;
1662 int skb_do_redirect(struct sk_buff
*skb
)
1664 struct redirect_info
*ri
= this_cpu_ptr(&redirect_info
);
1665 struct net_device
*dev
;
1667 dev
= dev_get_by_index_rcu(dev_net(skb
->dev
), ri
->ifindex
);
1669 if (unlikely(!dev
)) {
1674 if (ri
->flags
& BPF_F_INGRESS
) {
1675 if (skb_at_tc_ingress(skb
))
1676 skb_postpush_rcsum(skb
, skb_mac_header(skb
),
1678 return dev_forward_skb(dev
, skb
);
1682 return dev_queue_xmit(skb
);
1685 static const struct bpf_func_proto bpf_redirect_proto
= {
1686 .func
= bpf_redirect
,
1688 .ret_type
= RET_INTEGER
,
1689 .arg1_type
= ARG_ANYTHING
,
1690 .arg2_type
= ARG_ANYTHING
,
1693 static u64
bpf_get_cgroup_classid(u64 r1
, u64 r2
, u64 r3
, u64 r4
, u64 r5
)
1695 return task_get_classid((struct sk_buff
*) (unsigned long) r1
);
1698 static const struct bpf_func_proto bpf_get_cgroup_classid_proto
= {
1699 .func
= bpf_get_cgroup_classid
,
1701 .ret_type
= RET_INTEGER
,
1702 .arg1_type
= ARG_PTR_TO_CTX
,
1705 static u64
bpf_get_route_realm(u64 r1
, u64 r2
, u64 r3
, u64 r4
, u64 r5
)
1707 return dst_tclassid((struct sk_buff
*) (unsigned long) r1
);
1710 static const struct bpf_func_proto bpf_get_route_realm_proto
= {
1711 .func
= bpf_get_route_realm
,
1713 .ret_type
= RET_INTEGER
,
1714 .arg1_type
= ARG_PTR_TO_CTX
,
1717 static u64
bpf_skb_vlan_push(u64 r1
, u64 r2
, u64 vlan_tci
, u64 r4
, u64 r5
)
1719 struct sk_buff
*skb
= (struct sk_buff
*) (long) r1
;
1720 __be16 vlan_proto
= (__force __be16
) r2
;
1723 if (unlikely(vlan_proto
!= htons(ETH_P_8021Q
) &&
1724 vlan_proto
!= htons(ETH_P_8021AD
)))
1725 vlan_proto
= htons(ETH_P_8021Q
);
1727 ret
= skb_vlan_push(skb
, vlan_proto
, vlan_tci
);
1728 bpf_compute_data_end(skb
);
1732 const struct bpf_func_proto bpf_skb_vlan_push_proto
= {
1733 .func
= bpf_skb_vlan_push
,
1735 .ret_type
= RET_INTEGER
,
1736 .arg1_type
= ARG_PTR_TO_CTX
,
1737 .arg2_type
= ARG_ANYTHING
,
1738 .arg3_type
= ARG_ANYTHING
,
1740 EXPORT_SYMBOL_GPL(bpf_skb_vlan_push_proto
);
1742 static u64
bpf_skb_vlan_pop(u64 r1
, u64 r2
, u64 r3
, u64 r4
, u64 r5
)
1744 struct sk_buff
*skb
= (struct sk_buff
*) (long) r1
;
1747 ret
= skb_vlan_pop(skb
);
1748 bpf_compute_data_end(skb
);
1752 const struct bpf_func_proto bpf_skb_vlan_pop_proto
= {
1753 .func
= bpf_skb_vlan_pop
,
1755 .ret_type
= RET_INTEGER
,
1756 .arg1_type
= ARG_PTR_TO_CTX
,
1758 EXPORT_SYMBOL_GPL(bpf_skb_vlan_pop_proto
);
1760 bool bpf_helper_changes_skb_data(void *func
)
1762 if (func
== bpf_skb_vlan_push
)
1764 if (func
== bpf_skb_vlan_pop
)
1766 if (func
== bpf_skb_store_bytes
)
1768 if (func
== bpf_l3_csum_replace
)
1770 if (func
== bpf_l4_csum_replace
)
1776 static unsigned short bpf_tunnel_key_af(u64 flags
)
1778 return flags
& BPF_F_TUNINFO_IPV6
? AF_INET6
: AF_INET
;
1781 static u64
bpf_skb_get_tunnel_key(u64 r1
, u64 r2
, u64 size
, u64 flags
, u64 r5
)
1783 struct sk_buff
*skb
= (struct sk_buff
*) (long) r1
;
1784 struct bpf_tunnel_key
*to
= (struct bpf_tunnel_key
*) (long) r2
;
1785 const struct ip_tunnel_info
*info
= skb_tunnel_info(skb
);
1786 u8 compat
[sizeof(struct bpf_tunnel_key
)];
1790 if (unlikely(!info
|| (flags
& ~(BPF_F_TUNINFO_IPV6
)))) {
1794 if (ip_tunnel_info_af(info
) != bpf_tunnel_key_af(flags
)) {
1798 if (unlikely(size
!= sizeof(struct bpf_tunnel_key
))) {
1801 case offsetof(struct bpf_tunnel_key
, tunnel_label
):
1802 case offsetof(struct bpf_tunnel_key
, tunnel_ext
):
1804 case offsetof(struct bpf_tunnel_key
, remote_ipv6
[1]):
1805 /* Fixup deprecated structure layouts here, so we have
1806 * a common path later on.
1808 if (ip_tunnel_info_af(info
) != AF_INET
)
1811 to
= (struct bpf_tunnel_key
*)compat
;
1818 to
->tunnel_id
= be64_to_cpu(info
->key
.tun_id
);
1819 to
->tunnel_tos
= info
->key
.tos
;
1820 to
->tunnel_ttl
= info
->key
.ttl
;
1822 if (flags
& BPF_F_TUNINFO_IPV6
) {
1823 memcpy(to
->remote_ipv6
, &info
->key
.u
.ipv6
.src
,
1824 sizeof(to
->remote_ipv6
));
1825 to
->tunnel_label
= be32_to_cpu(info
->key
.label
);
1827 to
->remote_ipv4
= be32_to_cpu(info
->key
.u
.ipv4
.src
);
1830 if (unlikely(size
!= sizeof(struct bpf_tunnel_key
)))
1831 memcpy(to_orig
, to
, size
);
1835 memset(to_orig
, 0, size
);
1839 static const struct bpf_func_proto bpf_skb_get_tunnel_key_proto
= {
1840 .func
= bpf_skb_get_tunnel_key
,
1842 .ret_type
= RET_INTEGER
,
1843 .arg1_type
= ARG_PTR_TO_CTX
,
1844 .arg2_type
= ARG_PTR_TO_RAW_STACK
,
1845 .arg3_type
= ARG_CONST_STACK_SIZE
,
1846 .arg4_type
= ARG_ANYTHING
,
1849 static u64
bpf_skb_get_tunnel_opt(u64 r1
, u64 r2
, u64 size
, u64 r4
, u64 r5
)
1851 struct sk_buff
*skb
= (struct sk_buff
*) (long) r1
;
1852 u8
*to
= (u8
*) (long) r2
;
1853 const struct ip_tunnel_info
*info
= skb_tunnel_info(skb
);
1856 if (unlikely(!info
||
1857 !(info
->key
.tun_flags
& TUNNEL_OPTIONS_PRESENT
))) {
1861 if (unlikely(size
< info
->options_len
)) {
1866 ip_tunnel_info_opts_get(to
, info
);
1867 if (size
> info
->options_len
)
1868 memset(to
+ info
->options_len
, 0, size
- info
->options_len
);
1870 return info
->options_len
;
1872 memset(to
, 0, size
);
1876 static const struct bpf_func_proto bpf_skb_get_tunnel_opt_proto
= {
1877 .func
= bpf_skb_get_tunnel_opt
,
1879 .ret_type
= RET_INTEGER
,
1880 .arg1_type
= ARG_PTR_TO_CTX
,
1881 .arg2_type
= ARG_PTR_TO_RAW_STACK
,
1882 .arg3_type
= ARG_CONST_STACK_SIZE
,
1885 static struct metadata_dst __percpu
*md_dst
;
1887 static u64
bpf_skb_set_tunnel_key(u64 r1
, u64 r2
, u64 size
, u64 flags
, u64 r5
)
1889 struct sk_buff
*skb
= (struct sk_buff
*) (long) r1
;
1890 struct bpf_tunnel_key
*from
= (struct bpf_tunnel_key
*) (long) r2
;
1891 struct metadata_dst
*md
= this_cpu_ptr(md_dst
);
1892 u8 compat
[sizeof(struct bpf_tunnel_key
)];
1893 struct ip_tunnel_info
*info
;
1895 if (unlikely(flags
& ~(BPF_F_TUNINFO_IPV6
| BPF_F_ZERO_CSUM_TX
|
1896 BPF_F_DONT_FRAGMENT
)))
1898 if (unlikely(size
!= sizeof(struct bpf_tunnel_key
))) {
1900 case offsetof(struct bpf_tunnel_key
, tunnel_label
):
1901 case offsetof(struct bpf_tunnel_key
, tunnel_ext
):
1902 case offsetof(struct bpf_tunnel_key
, remote_ipv6
[1]):
1903 /* Fixup deprecated structure layouts here, so we have
1904 * a common path later on.
1906 memcpy(compat
, from
, size
);
1907 memset(compat
+ size
, 0, sizeof(compat
) - size
);
1908 from
= (struct bpf_tunnel_key
*)compat
;
1914 if (unlikely((!(flags
& BPF_F_TUNINFO_IPV6
) && from
->tunnel_label
) ||
1919 dst_hold((struct dst_entry
*) md
);
1920 skb_dst_set(skb
, (struct dst_entry
*) md
);
1922 info
= &md
->u
.tun_info
;
1923 info
->mode
= IP_TUNNEL_INFO_TX
;
1925 info
->key
.tun_flags
= TUNNEL_KEY
| TUNNEL_CSUM
| TUNNEL_NOCACHE
;
1926 if (flags
& BPF_F_DONT_FRAGMENT
)
1927 info
->key
.tun_flags
|= TUNNEL_DONT_FRAGMENT
;
1929 info
->key
.tun_id
= cpu_to_be64(from
->tunnel_id
);
1930 info
->key
.tos
= from
->tunnel_tos
;
1931 info
->key
.ttl
= from
->tunnel_ttl
;
1933 if (flags
& BPF_F_TUNINFO_IPV6
) {
1934 info
->mode
|= IP_TUNNEL_INFO_IPV6
;
1935 memcpy(&info
->key
.u
.ipv6
.dst
, from
->remote_ipv6
,
1936 sizeof(from
->remote_ipv6
));
1937 info
->key
.label
= cpu_to_be32(from
->tunnel_label
) &
1938 IPV6_FLOWLABEL_MASK
;
1940 info
->key
.u
.ipv4
.dst
= cpu_to_be32(from
->remote_ipv4
);
1941 if (flags
& BPF_F_ZERO_CSUM_TX
)
1942 info
->key
.tun_flags
&= ~TUNNEL_CSUM
;
1948 static const struct bpf_func_proto bpf_skb_set_tunnel_key_proto
= {
1949 .func
= bpf_skb_set_tunnel_key
,
1951 .ret_type
= RET_INTEGER
,
1952 .arg1_type
= ARG_PTR_TO_CTX
,
1953 .arg2_type
= ARG_PTR_TO_STACK
,
1954 .arg3_type
= ARG_CONST_STACK_SIZE
,
1955 .arg4_type
= ARG_ANYTHING
,
1958 static u64
bpf_skb_set_tunnel_opt(u64 r1
, u64 r2
, u64 size
, u64 r4
, u64 r5
)
1960 struct sk_buff
*skb
= (struct sk_buff
*) (long) r1
;
1961 u8
*from
= (u8
*) (long) r2
;
1962 struct ip_tunnel_info
*info
= skb_tunnel_info(skb
);
1963 const struct metadata_dst
*md
= this_cpu_ptr(md_dst
);
1965 if (unlikely(info
!= &md
->u
.tun_info
|| (size
& (sizeof(u32
) - 1))))
1967 if (unlikely(size
> IP_TUNNEL_OPTS_MAX
))
1970 ip_tunnel_info_opts_set(info
, from
, size
);
1975 static const struct bpf_func_proto bpf_skb_set_tunnel_opt_proto
= {
1976 .func
= bpf_skb_set_tunnel_opt
,
1978 .ret_type
= RET_INTEGER
,
1979 .arg1_type
= ARG_PTR_TO_CTX
,
1980 .arg2_type
= ARG_PTR_TO_STACK
,
1981 .arg3_type
= ARG_CONST_STACK_SIZE
,
1984 static const struct bpf_func_proto
*
1985 bpf_get_skb_set_tunnel_proto(enum bpf_func_id which
)
1988 /* Race is not possible, since it's called from verifier
1989 * that is holding verifier mutex.
1991 md_dst
= metadata_dst_alloc_percpu(IP_TUNNEL_OPTS_MAX
,
1998 case BPF_FUNC_skb_set_tunnel_key
:
1999 return &bpf_skb_set_tunnel_key_proto
;
2000 case BPF_FUNC_skb_set_tunnel_opt
:
2001 return &bpf_skb_set_tunnel_opt_proto
;
2007 static const struct bpf_func_proto
*
2008 sk_filter_func_proto(enum bpf_func_id func_id
)
2011 case BPF_FUNC_map_lookup_elem
:
2012 return &bpf_map_lookup_elem_proto
;
2013 case BPF_FUNC_map_update_elem
:
2014 return &bpf_map_update_elem_proto
;
2015 case BPF_FUNC_map_delete_elem
:
2016 return &bpf_map_delete_elem_proto
;
2017 case BPF_FUNC_get_prandom_u32
:
2018 return &bpf_get_prandom_u32_proto
;
2019 case BPF_FUNC_get_smp_processor_id
:
2020 return &bpf_get_smp_processor_id_proto
;
2021 case BPF_FUNC_tail_call
:
2022 return &bpf_tail_call_proto
;
2023 case BPF_FUNC_ktime_get_ns
:
2024 return &bpf_ktime_get_ns_proto
;
2025 case BPF_FUNC_trace_printk
:
2026 if (capable(CAP_SYS_ADMIN
))
2027 return bpf_get_trace_printk_proto();
2033 static const struct bpf_func_proto
*
2034 tc_cls_act_func_proto(enum bpf_func_id func_id
)
2037 case BPF_FUNC_skb_store_bytes
:
2038 return &bpf_skb_store_bytes_proto
;
2039 case BPF_FUNC_skb_load_bytes
:
2040 return &bpf_skb_load_bytes_proto
;
2041 case BPF_FUNC_csum_diff
:
2042 return &bpf_csum_diff_proto
;
2043 case BPF_FUNC_l3_csum_replace
:
2044 return &bpf_l3_csum_replace_proto
;
2045 case BPF_FUNC_l4_csum_replace
:
2046 return &bpf_l4_csum_replace_proto
;
2047 case BPF_FUNC_clone_redirect
:
2048 return &bpf_clone_redirect_proto
;
2049 case BPF_FUNC_get_cgroup_classid
:
2050 return &bpf_get_cgroup_classid_proto
;
2051 case BPF_FUNC_skb_vlan_push
:
2052 return &bpf_skb_vlan_push_proto
;
2053 case BPF_FUNC_skb_vlan_pop
:
2054 return &bpf_skb_vlan_pop_proto
;
2055 case BPF_FUNC_skb_get_tunnel_key
:
2056 return &bpf_skb_get_tunnel_key_proto
;
2057 case BPF_FUNC_skb_set_tunnel_key
:
2058 return bpf_get_skb_set_tunnel_proto(func_id
);
2059 case BPF_FUNC_skb_get_tunnel_opt
:
2060 return &bpf_skb_get_tunnel_opt_proto
;
2061 case BPF_FUNC_skb_set_tunnel_opt
:
2062 return bpf_get_skb_set_tunnel_proto(func_id
);
2063 case BPF_FUNC_redirect
:
2064 return &bpf_redirect_proto
;
2065 case BPF_FUNC_get_route_realm
:
2066 return &bpf_get_route_realm_proto
;
2067 case BPF_FUNC_perf_event_output
:
2068 return bpf_get_event_output_proto();
2070 return sk_filter_func_proto(func_id
);
2074 static bool __is_valid_access(int off
, int size
, enum bpf_access_type type
)
2076 if (off
< 0 || off
>= sizeof(struct __sk_buff
))
2078 /* The verifier guarantees that size > 0. */
2079 if (off
% size
!= 0)
2081 if (size
!= sizeof(__u32
))
2087 static bool sk_filter_is_valid_access(int off
, int size
,
2088 enum bpf_access_type type
,
2089 enum bpf_reg_type
*reg_type
)
2092 case offsetof(struct __sk_buff
, tc_classid
):
2093 case offsetof(struct __sk_buff
, data
):
2094 case offsetof(struct __sk_buff
, data_end
):
2098 if (type
== BPF_WRITE
) {
2100 case offsetof(struct __sk_buff
, cb
[0]) ...
2101 offsetof(struct __sk_buff
, cb
[4]):
2108 return __is_valid_access(off
, size
, type
);
2111 static bool tc_cls_act_is_valid_access(int off
, int size
,
2112 enum bpf_access_type type
,
2113 enum bpf_reg_type
*reg_type
)
2115 if (type
== BPF_WRITE
) {
2117 case offsetof(struct __sk_buff
, mark
):
2118 case offsetof(struct __sk_buff
, tc_index
):
2119 case offsetof(struct __sk_buff
, priority
):
2120 case offsetof(struct __sk_buff
, cb
[0]) ...
2121 offsetof(struct __sk_buff
, cb
[4]):
2122 case offsetof(struct __sk_buff
, tc_classid
):
2130 case offsetof(struct __sk_buff
, data
):
2131 *reg_type
= PTR_TO_PACKET
;
2133 case offsetof(struct __sk_buff
, data_end
):
2134 *reg_type
= PTR_TO_PACKET_END
;
2138 return __is_valid_access(off
, size
, type
);
2141 static u32
bpf_net_convert_ctx_access(enum bpf_access_type type
, int dst_reg
,
2142 int src_reg
, int ctx_off
,
2143 struct bpf_insn
*insn_buf
,
2144 struct bpf_prog
*prog
)
2146 struct bpf_insn
*insn
= insn_buf
;
2149 case offsetof(struct __sk_buff
, len
):
2150 BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff
, len
) != 4);
2152 *insn
++ = BPF_LDX_MEM(BPF_W
, dst_reg
, src_reg
,
2153 offsetof(struct sk_buff
, len
));
2156 case offsetof(struct __sk_buff
, protocol
):
2157 BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff
, protocol
) != 2);
2159 *insn
++ = BPF_LDX_MEM(BPF_H
, dst_reg
, src_reg
,
2160 offsetof(struct sk_buff
, protocol
));
2163 case offsetof(struct __sk_buff
, vlan_proto
):
2164 BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff
, vlan_proto
) != 2);
2166 *insn
++ = BPF_LDX_MEM(BPF_H
, dst_reg
, src_reg
,
2167 offsetof(struct sk_buff
, vlan_proto
));
2170 case offsetof(struct __sk_buff
, priority
):
2171 BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff
, priority
) != 4);
2173 if (type
== BPF_WRITE
)
2174 *insn
++ = BPF_STX_MEM(BPF_W
, dst_reg
, src_reg
,
2175 offsetof(struct sk_buff
, priority
));
2177 *insn
++ = BPF_LDX_MEM(BPF_W
, dst_reg
, src_reg
,
2178 offsetof(struct sk_buff
, priority
));
2181 case offsetof(struct __sk_buff
, ingress_ifindex
):
2182 BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff
, skb_iif
) != 4);
2184 *insn
++ = BPF_LDX_MEM(BPF_W
, dst_reg
, src_reg
,
2185 offsetof(struct sk_buff
, skb_iif
));
2188 case offsetof(struct __sk_buff
, ifindex
):
2189 BUILD_BUG_ON(FIELD_SIZEOF(struct net_device
, ifindex
) != 4);
2191 *insn
++ = BPF_LDX_MEM(bytes_to_bpf_size(FIELD_SIZEOF(struct sk_buff
, dev
)),
2193 offsetof(struct sk_buff
, dev
));
2194 *insn
++ = BPF_JMP_IMM(BPF_JEQ
, dst_reg
, 0, 1);
2195 *insn
++ = BPF_LDX_MEM(BPF_W
, dst_reg
, dst_reg
,
2196 offsetof(struct net_device
, ifindex
));
2199 case offsetof(struct __sk_buff
, hash
):
2200 BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff
, hash
) != 4);
2202 *insn
++ = BPF_LDX_MEM(BPF_W
, dst_reg
, src_reg
,
2203 offsetof(struct sk_buff
, hash
));
2206 case offsetof(struct __sk_buff
, mark
):
2207 BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff
, mark
) != 4);
2209 if (type
== BPF_WRITE
)
2210 *insn
++ = BPF_STX_MEM(BPF_W
, dst_reg
, src_reg
,
2211 offsetof(struct sk_buff
, mark
));
2213 *insn
++ = BPF_LDX_MEM(BPF_W
, dst_reg
, src_reg
,
2214 offsetof(struct sk_buff
, mark
));
2217 case offsetof(struct __sk_buff
, pkt_type
):
2218 return convert_skb_access(SKF_AD_PKTTYPE
, dst_reg
, src_reg
, insn
);
2220 case offsetof(struct __sk_buff
, queue_mapping
):
2221 return convert_skb_access(SKF_AD_QUEUE
, dst_reg
, src_reg
, insn
);
2223 case offsetof(struct __sk_buff
, vlan_present
):
2224 return convert_skb_access(SKF_AD_VLAN_TAG_PRESENT
,
2225 dst_reg
, src_reg
, insn
);
2227 case offsetof(struct __sk_buff
, vlan_tci
):
2228 return convert_skb_access(SKF_AD_VLAN_TAG
,
2229 dst_reg
, src_reg
, insn
);
2231 case offsetof(struct __sk_buff
, cb
[0]) ...
2232 offsetof(struct __sk_buff
, cb
[4]):
2233 BUILD_BUG_ON(FIELD_SIZEOF(struct qdisc_skb_cb
, data
) < 20);
2235 prog
->cb_access
= 1;
2236 ctx_off
-= offsetof(struct __sk_buff
, cb
[0]);
2237 ctx_off
+= offsetof(struct sk_buff
, cb
);
2238 ctx_off
+= offsetof(struct qdisc_skb_cb
, data
);
2239 if (type
== BPF_WRITE
)
2240 *insn
++ = BPF_STX_MEM(BPF_W
, dst_reg
, src_reg
, ctx_off
);
2242 *insn
++ = BPF_LDX_MEM(BPF_W
, dst_reg
, src_reg
, ctx_off
);
2245 case offsetof(struct __sk_buff
, tc_classid
):
2246 ctx_off
-= offsetof(struct __sk_buff
, tc_classid
);
2247 ctx_off
+= offsetof(struct sk_buff
, cb
);
2248 ctx_off
+= offsetof(struct qdisc_skb_cb
, tc_classid
);
2249 if (type
== BPF_WRITE
)
2250 *insn
++ = BPF_STX_MEM(BPF_H
, dst_reg
, src_reg
, ctx_off
);
2252 *insn
++ = BPF_LDX_MEM(BPF_H
, dst_reg
, src_reg
, ctx_off
);
2255 case offsetof(struct __sk_buff
, data
):
2256 *insn
++ = BPF_LDX_MEM(bytes_to_bpf_size(FIELD_SIZEOF(struct sk_buff
, data
)),
2258 offsetof(struct sk_buff
, data
));
2261 case offsetof(struct __sk_buff
, data_end
):
2262 ctx_off
-= offsetof(struct __sk_buff
, data_end
);
2263 ctx_off
+= offsetof(struct sk_buff
, cb
);
2264 ctx_off
+= offsetof(struct bpf_skb_data_end
, data_end
);
2265 *insn
++ = BPF_LDX_MEM(bytes_to_bpf_size(sizeof(void *)),
2266 dst_reg
, src_reg
, ctx_off
);
2269 case offsetof(struct __sk_buff
, tc_index
):
2270 #ifdef CONFIG_NET_SCHED
2271 BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff
, tc_index
) != 2);
2273 if (type
== BPF_WRITE
)
2274 *insn
++ = BPF_STX_MEM(BPF_H
, dst_reg
, src_reg
,
2275 offsetof(struct sk_buff
, tc_index
));
2277 *insn
++ = BPF_LDX_MEM(BPF_H
, dst_reg
, src_reg
,
2278 offsetof(struct sk_buff
, tc_index
));
2281 if (type
== BPF_WRITE
)
2282 *insn
++ = BPF_MOV64_REG(dst_reg
, dst_reg
);
2284 *insn
++ = BPF_MOV64_IMM(dst_reg
, 0);
2289 return insn
- insn_buf
;
2292 static const struct bpf_verifier_ops sk_filter_ops
= {
2293 .get_func_proto
= sk_filter_func_proto
,
2294 .is_valid_access
= sk_filter_is_valid_access
,
2295 .convert_ctx_access
= bpf_net_convert_ctx_access
,
2298 static const struct bpf_verifier_ops tc_cls_act_ops
= {
2299 .get_func_proto
= tc_cls_act_func_proto
,
2300 .is_valid_access
= tc_cls_act_is_valid_access
,
2301 .convert_ctx_access
= bpf_net_convert_ctx_access
,
2304 static struct bpf_prog_type_list sk_filter_type __read_mostly
= {
2305 .ops
= &sk_filter_ops
,
2306 .type
= BPF_PROG_TYPE_SOCKET_FILTER
,
2309 static struct bpf_prog_type_list sched_cls_type __read_mostly
= {
2310 .ops
= &tc_cls_act_ops
,
2311 .type
= BPF_PROG_TYPE_SCHED_CLS
,
2314 static struct bpf_prog_type_list sched_act_type __read_mostly
= {
2315 .ops
= &tc_cls_act_ops
,
2316 .type
= BPF_PROG_TYPE_SCHED_ACT
,
2319 static int __init
register_sk_filter_ops(void)
2321 bpf_register_prog_type(&sk_filter_type
);
2322 bpf_register_prog_type(&sched_cls_type
);
2323 bpf_register_prog_type(&sched_act_type
);
2327 late_initcall(register_sk_filter_ops
);
2329 int sk_detach_filter(struct sock
*sk
)
2332 struct sk_filter
*filter
;
2334 if (sock_flag(sk
, SOCK_FILTER_LOCKED
))
2337 filter
= rcu_dereference_protected(sk
->sk_filter
,
2338 lockdep_sock_is_held(sk
));
2340 RCU_INIT_POINTER(sk
->sk_filter
, NULL
);
2341 sk_filter_uncharge(sk
, filter
);
2347 EXPORT_SYMBOL_GPL(sk_detach_filter
);
2349 int sk_get_filter(struct sock
*sk
, struct sock_filter __user
*ubuf
,
2352 struct sock_fprog_kern
*fprog
;
2353 struct sk_filter
*filter
;
2357 filter
= rcu_dereference_protected(sk
->sk_filter
,
2358 lockdep_sock_is_held(sk
));
2362 /* We're copying the filter that has been originally attached,
2363 * so no conversion/decode needed anymore. eBPF programs that
2364 * have no original program cannot be dumped through this.
2367 fprog
= filter
->prog
->orig_prog
;
2373 /* User space only enquires number of filter blocks. */
2377 if (len
< fprog
->len
)
2381 if (copy_to_user(ubuf
, fprog
->filter
, bpf_classic_proglen(fprog
)))
2384 /* Instead of bytes, the API requests to return the number