Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * Linux Socket Filter - Kernel level socket filtering | |
3 | * | |
bd4cf0ed AS |
4 | * Based on the design of the Berkeley Packet Filter. The new |
5 | * internal format has been designed by PLUMgrid: | |
1da177e4 | 6 | * |
bd4cf0ed AS |
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> | |
1da177e4 LT |
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. | |
4df95ff4 | 21 | * Kris Katterjohn - Added many additional checks in bpf_check_classic() |
1da177e4 LT |
22 | */ |
23 | ||
24 | #include <linux/module.h> | |
25 | #include <linux/types.h> | |
1da177e4 LT |
26 | #include <linux/mm.h> |
27 | #include <linux/fcntl.h> | |
28 | #include <linux/socket.h> | |
29 | #include <linux/in.h> | |
30 | #include <linux/inet.h> | |
31 | #include <linux/netdevice.h> | |
32 | #include <linux/if_packet.h> | |
5a0e3ad6 | 33 | #include <linux/gfp.h> |
1da177e4 LT |
34 | #include <net/ip.h> |
35 | #include <net/protocol.h> | |
4738c1db | 36 | #include <net/netlink.h> |
1da177e4 LT |
37 | #include <linux/skbuff.h> |
38 | #include <net/sock.h> | |
10b89ee4 | 39 | #include <net/flow_dissector.h> |
1da177e4 LT |
40 | #include <linux/errno.h> |
41 | #include <linux/timer.h> | |
1da177e4 | 42 | #include <asm/uaccess.h> |
40daafc8 | 43 | #include <asm/unaligned.h> |
1da177e4 | 44 | #include <linux/filter.h> |
86e4ca66 | 45 | #include <linux/ratelimit.h> |
46b325c7 | 46 | #include <linux/seccomp.h> |
f3335031 | 47 | #include <linux/if_vlan.h> |
89aa0758 | 48 | #include <linux/bpf.h> |
d691f9e8 | 49 | #include <net/sch_generic.h> |
8d20aabe | 50 | #include <net/cls_cgroup.h> |
d3aa45ce | 51 | #include <net/dst_metadata.h> |
c46646d0 | 52 | #include <net/dst.h> |
538950a1 | 53 | #include <net/sock_reuseport.h> |
1da177e4 | 54 | |
43db6d65 SH |
55 | /** |
56 | * sk_filter - run a packet through a socket filter | |
57 | * @sk: sock associated with &sk_buff | |
58 | * @skb: buffer to filter | |
43db6d65 | 59 | * |
ff936a04 AS |
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 | |
43db6d65 | 62 | * than pkt_len we keep whole skb->data. This is the socket level |
ff936a04 | 63 | * wrapper to BPF_PROG_RUN. It returns 0 if the packet should |
43db6d65 SH |
64 | * be accepted or -EPERM if the packet should be tossed. |
65 | * | |
66 | */ | |
67 | int sk_filter(struct sock *sk, struct sk_buff *skb) | |
68 | { | |
69 | int err; | |
70 | struct sk_filter *filter; | |
71 | ||
c93bdd0e MG |
72 | /* |
73 | * If the skb was allocated from pfmemalloc reserves, only | |
74 | * allow SOCK_MEMALLOC sockets to use it as this socket is | |
75 | * helping free memory | |
76 | */ | |
77 | if (skb_pfmemalloc(skb) && !sock_flag(sk, SOCK_MEMALLOC)) | |
78 | return -ENOMEM; | |
79 | ||
43db6d65 SH |
80 | err = security_sock_rcv_skb(sk, skb); |
81 | if (err) | |
82 | return err; | |
83 | ||
80f8f102 ED |
84 | rcu_read_lock(); |
85 | filter = rcu_dereference(sk->sk_filter); | |
43db6d65 | 86 | if (filter) { |
ff936a04 | 87 | unsigned int pkt_len = bpf_prog_run_save_cb(filter->prog, skb); |
0d7da9dd | 88 | |
43db6d65 SH |
89 | err = pkt_len ? pskb_trim(skb, pkt_len) : -EPERM; |
90 | } | |
80f8f102 | 91 | rcu_read_unlock(); |
43db6d65 SH |
92 | |
93 | return err; | |
94 | } | |
95 | EXPORT_SYMBOL(sk_filter); | |
96 | ||
30743837 | 97 | static u64 __skb_get_pay_offset(u64 ctx, u64 a, u64 x, u64 r4, u64 r5) |
bd4cf0ed | 98 | { |
56193d1b | 99 | return skb_get_poff((struct sk_buff *)(unsigned long) ctx); |
bd4cf0ed AS |
100 | } |
101 | ||
30743837 | 102 | static u64 __skb_get_nlattr(u64 ctx, u64 a, u64 x, u64 r4, u64 r5) |
bd4cf0ed | 103 | { |
eb9672f4 | 104 | struct sk_buff *skb = (struct sk_buff *)(unsigned long) ctx; |
bd4cf0ed AS |
105 | struct nlattr *nla; |
106 | ||
107 | if (skb_is_nonlinear(skb)) | |
108 | return 0; | |
109 | ||
05ab8f26 MK |
110 | if (skb->len < sizeof(struct nlattr)) |
111 | return 0; | |
112 | ||
30743837 | 113 | if (a > skb->len - sizeof(struct nlattr)) |
bd4cf0ed AS |
114 | return 0; |
115 | ||
30743837 | 116 | nla = nla_find((struct nlattr *) &skb->data[a], skb->len - a, x); |
bd4cf0ed AS |
117 | if (nla) |
118 | return (void *) nla - (void *) skb->data; | |
119 | ||
120 | return 0; | |
121 | } | |
122 | ||
30743837 | 123 | static u64 __skb_get_nlattr_nest(u64 ctx, u64 a, u64 x, u64 r4, u64 r5) |
bd4cf0ed | 124 | { |
eb9672f4 | 125 | struct sk_buff *skb = (struct sk_buff *)(unsigned long) ctx; |
bd4cf0ed AS |
126 | struct nlattr *nla; |
127 | ||
128 | if (skb_is_nonlinear(skb)) | |
129 | return 0; | |
130 | ||
05ab8f26 MK |
131 | if (skb->len < sizeof(struct nlattr)) |
132 | return 0; | |
133 | ||
30743837 | 134 | if (a > skb->len - sizeof(struct nlattr)) |
bd4cf0ed AS |
135 | return 0; |
136 | ||
30743837 DB |
137 | nla = (struct nlattr *) &skb->data[a]; |
138 | if (nla->nla_len > skb->len - a) | |
bd4cf0ed AS |
139 | return 0; |
140 | ||
30743837 | 141 | nla = nla_find_nested(nla, x); |
bd4cf0ed AS |
142 | if (nla) |
143 | return (void *) nla - (void *) skb->data; | |
144 | ||
145 | return 0; | |
146 | } | |
147 | ||
30743837 | 148 | static u64 __get_raw_cpu_id(u64 ctx, u64 a, u64 x, u64 r4, u64 r5) |
bd4cf0ed AS |
149 | { |
150 | return raw_smp_processor_id(); | |
151 | } | |
152 | ||
9bac3d6d AS |
153 | static u32 convert_skb_access(int skb_field, int dst_reg, int src_reg, |
154 | struct bpf_insn *insn_buf) | |
155 | { | |
156 | struct bpf_insn *insn = insn_buf; | |
157 | ||
158 | switch (skb_field) { | |
159 | case SKF_AD_MARK: | |
160 | BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, mark) != 4); | |
161 | ||
162 | *insn++ = BPF_LDX_MEM(BPF_W, dst_reg, src_reg, | |
163 | offsetof(struct sk_buff, mark)); | |
164 | break; | |
165 | ||
166 | case SKF_AD_PKTTYPE: | |
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); | |
171 | #endif | |
172 | break; | |
173 | ||
174 | case SKF_AD_QUEUE: | |
175 | BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, queue_mapping) != 2); | |
176 | ||
177 | *insn++ = BPF_LDX_MEM(BPF_H, dst_reg, src_reg, | |
178 | offsetof(struct sk_buff, queue_mapping)); | |
179 | break; | |
c2497395 | 180 | |
c2497395 AS |
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); | |
185 | ||
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, | |
191 | ~VLAN_TAG_PRESENT); | |
192 | } else { | |
193 | /* dst_reg >>= 12 */ | |
194 | *insn++ = BPF_ALU32_IMM(BPF_RSH, dst_reg, 12); | |
195 | /* dst_reg &= 1 */ | |
196 | *insn++ = BPF_ALU32_IMM(BPF_AND, dst_reg, 1); | |
197 | } | |
198 | break; | |
9bac3d6d AS |
199 | } |
200 | ||
201 | return insn - insn_buf; | |
202 | } | |
203 | ||
bd4cf0ed | 204 | static bool convert_bpf_extensions(struct sock_filter *fp, |
2695fb55 | 205 | struct bpf_insn **insnp) |
bd4cf0ed | 206 | { |
2695fb55 | 207 | struct bpf_insn *insn = *insnp; |
9bac3d6d | 208 | u32 cnt; |
bd4cf0ed AS |
209 | |
210 | switch (fp->k) { | |
211 | case SKF_AD_OFF + SKF_AD_PROTOCOL: | |
0b8c707d DB |
212 | BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, protocol) != 2); |
213 | ||
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); | |
bd4cf0ed AS |
219 | break; |
220 | ||
221 | case SKF_AD_OFF + SKF_AD_PKTTYPE: | |
9bac3d6d AS |
222 | cnt = convert_skb_access(SKF_AD_PKTTYPE, BPF_REG_A, BPF_REG_CTX, insn); |
223 | insn += cnt - 1; | |
bd4cf0ed AS |
224 | break; |
225 | ||
226 | case SKF_AD_OFF + SKF_AD_IFINDEX: | |
227 | case SKF_AD_OFF + SKF_AD_HATYPE: | |
bd4cf0ed AS |
228 | BUILD_BUG_ON(FIELD_SIZEOF(struct net_device, ifindex) != 4); |
229 | BUILD_BUG_ON(FIELD_SIZEOF(struct net_device, type) != 2); | |
f8f6d679 DB |
230 | BUILD_BUG_ON(bytes_to_bpf_size(FIELD_SIZEOF(struct sk_buff, dev)) < 0); |
231 | ||
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)); | |
241 | else | |
242 | *insn = BPF_LDX_MEM(BPF_H, BPF_REG_A, BPF_REG_TMP, | |
243 | offsetof(struct net_device, type)); | |
bd4cf0ed AS |
244 | break; |
245 | ||
246 | case SKF_AD_OFF + SKF_AD_MARK: | |
9bac3d6d AS |
247 | cnt = convert_skb_access(SKF_AD_MARK, BPF_REG_A, BPF_REG_CTX, insn); |
248 | insn += cnt - 1; | |
bd4cf0ed AS |
249 | break; |
250 | ||
251 | case SKF_AD_OFF + SKF_AD_RXHASH: | |
252 | BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, hash) != 4); | |
253 | ||
9739eef1 AS |
254 | *insn = BPF_LDX_MEM(BPF_W, BPF_REG_A, BPF_REG_CTX, |
255 | offsetof(struct sk_buff, hash)); | |
bd4cf0ed AS |
256 | break; |
257 | ||
258 | case SKF_AD_OFF + SKF_AD_QUEUE: | |
9bac3d6d AS |
259 | cnt = convert_skb_access(SKF_AD_QUEUE, BPF_REG_A, BPF_REG_CTX, insn); |
260 | insn += cnt - 1; | |
bd4cf0ed AS |
261 | break; |
262 | ||
263 | case SKF_AD_OFF + SKF_AD_VLAN_TAG: | |
c2497395 AS |
264 | cnt = convert_skb_access(SKF_AD_VLAN_TAG, |
265 | BPF_REG_A, BPF_REG_CTX, insn); | |
266 | insn += cnt - 1; | |
267 | break; | |
bd4cf0ed | 268 | |
c2497395 AS |
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); | |
272 | insn += cnt - 1; | |
bd4cf0ed AS |
273 | break; |
274 | ||
27cd5452 MS |
275 | case SKF_AD_OFF + SKF_AD_VLAN_TPID: |
276 | BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, vlan_proto) != 2); | |
277 | ||
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); | |
283 | break; | |
284 | ||
bd4cf0ed AS |
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: | |
4cd3675e | 289 | case SKF_AD_OFF + SKF_AD_RANDOM: |
e430f34e | 290 | /* arg1 = CTX */ |
f8f6d679 | 291 | *insn++ = BPF_MOV64_REG(BPF_REG_ARG1, BPF_REG_CTX); |
bd4cf0ed | 292 | /* arg2 = A */ |
f8f6d679 | 293 | *insn++ = BPF_MOV64_REG(BPF_REG_ARG2, BPF_REG_A); |
bd4cf0ed | 294 | /* arg3 = X */ |
f8f6d679 | 295 | *insn++ = BPF_MOV64_REG(BPF_REG_ARG3, BPF_REG_X); |
e430f34e | 296 | /* Emit call(arg1=CTX, arg2=A, arg3=X) */ |
bd4cf0ed AS |
297 | switch (fp->k) { |
298 | case SKF_AD_OFF + SKF_AD_PAY_OFFSET: | |
f8f6d679 | 299 | *insn = BPF_EMIT_CALL(__skb_get_pay_offset); |
bd4cf0ed AS |
300 | break; |
301 | case SKF_AD_OFF + SKF_AD_NLATTR: | |
f8f6d679 | 302 | *insn = BPF_EMIT_CALL(__skb_get_nlattr); |
bd4cf0ed AS |
303 | break; |
304 | case SKF_AD_OFF + SKF_AD_NLATTR_NEST: | |
f8f6d679 | 305 | *insn = BPF_EMIT_CALL(__skb_get_nlattr_nest); |
bd4cf0ed AS |
306 | break; |
307 | case SKF_AD_OFF + SKF_AD_CPU: | |
f8f6d679 | 308 | *insn = BPF_EMIT_CALL(__get_raw_cpu_id); |
bd4cf0ed | 309 | break; |
4cd3675e | 310 | case SKF_AD_OFF + SKF_AD_RANDOM: |
3ad00405 DB |
311 | *insn = BPF_EMIT_CALL(bpf_user_rnd_u32); |
312 | bpf_user_rnd_init_once(); | |
4cd3675e | 313 | break; |
bd4cf0ed AS |
314 | } |
315 | break; | |
316 | ||
317 | case SKF_AD_OFF + SKF_AD_ALU_XOR_X: | |
9739eef1 AS |
318 | /* A ^= X */ |
319 | *insn = BPF_ALU32_REG(BPF_XOR, BPF_REG_A, BPF_REG_X); | |
bd4cf0ed AS |
320 | break; |
321 | ||
322 | default: | |
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. | |
326 | */ | |
327 | BUG_ON(__bpf_call_base(0, 0, 0, 0, 0) != 0); | |
328 | return false; | |
329 | } | |
330 | ||
331 | *insnp = insn; | |
332 | return true; | |
333 | } | |
334 | ||
335 | /** | |
8fb575ca | 336 | * bpf_convert_filter - convert filter program |
bd4cf0ed AS |
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 | |
341 | * | |
342 | * Remap 'sock_filter' style BPF instruction set to 'sock_filter_ext' style. | |
343 | * Conversion workflow: | |
344 | * | |
345 | * 1) First pass for calculating the new program length: | |
8fb575ca | 346 | * bpf_convert_filter(old_prog, old_len, NULL, &new_len) |
bd4cf0ed AS |
347 | * |
348 | * 2) 2nd pass to remap in two passes: 1st pass finds new | |
349 | * jump offsets, 2nd pass remapping: | |
2695fb55 | 350 | * new_prog = kmalloc(sizeof(struct bpf_insn) * new_len); |
8fb575ca | 351 | * bpf_convert_filter(old_prog, old_len, new_prog, &new_len); |
bd4cf0ed | 352 | */ |
d9e12f42 NS |
353 | static int bpf_convert_filter(struct sock_filter *prog, int len, |
354 | struct bpf_insn *new_prog, int *new_len) | |
bd4cf0ed AS |
355 | { |
356 | int new_flen = 0, pass = 0, target, i; | |
2695fb55 | 357 | struct bpf_insn *new_insn; |
bd4cf0ed AS |
358 | struct sock_filter *fp; |
359 | int *addrs = NULL; | |
360 | u8 bpf_src; | |
361 | ||
362 | BUILD_BUG_ON(BPF_MEMWORDS * sizeof(u32) > MAX_BPF_STACK); | |
30743837 | 363 | BUILD_BUG_ON(BPF_REG_FP + 1 != MAX_BPF_REG); |
bd4cf0ed | 364 | |
6f9a093b | 365 | if (len <= 0 || len > BPF_MAXINSNS) |
bd4cf0ed AS |
366 | return -EINVAL; |
367 | ||
368 | if (new_prog) { | |
658da937 DB |
369 | addrs = kcalloc(len, sizeof(*addrs), |
370 | GFP_KERNEL | __GFP_NOWARN); | |
bd4cf0ed AS |
371 | if (!addrs) |
372 | return -ENOMEM; | |
373 | } | |
374 | ||
375 | do_pass: | |
376 | new_insn = new_prog; | |
377 | fp = prog; | |
378 | ||
8b614aeb DB |
379 | /* Classic BPF related prologue emission. */ |
380 | if (new_insn) { | |
381 | /* Classic BPF expects A and X to be reset first. These need | |
382 | * to be guaranteed to be the first two instructions. | |
383 | */ | |
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); | |
386 | ||
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. | |
390 | */ | |
391 | *new_insn++ = BPF_MOV64_REG(BPF_REG_CTX, BPF_REG_ARG1); | |
392 | } else { | |
393 | new_insn += 3; | |
394 | } | |
bd4cf0ed AS |
395 | |
396 | for (i = 0; i < len; fp++, i++) { | |
2695fb55 AS |
397 | struct bpf_insn tmp_insns[6] = { }; |
398 | struct bpf_insn *insn = tmp_insns; | |
bd4cf0ed AS |
399 | |
400 | if (addrs) | |
401 | addrs[i] = new_insn - new_prog; | |
402 | ||
403 | switch (fp->code) { | |
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. | |
435 | */ | |
436 | if (BPF_CLASS(fp->code) == BPF_LD && | |
437 | BPF_MODE(fp->code) == BPF_ABS && | |
438 | convert_bpf_extensions(fp, &insn)) | |
439 | break; | |
440 | ||
f8f6d679 | 441 | *insn = BPF_RAW_INSN(fp->code, BPF_REG_A, BPF_REG_X, 0, fp->k); |
bd4cf0ed AS |
442 | break; |
443 | ||
f8f6d679 DB |
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. | |
448 | */ | |
449 | ||
450 | #define BPF_EMIT_JMP \ | |
bd4cf0ed AS |
451 | do { \ |
452 | if (target >= len || target < 0) \ | |
453 | goto err; \ | |
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; \ | |
457 | } while (0) | |
458 | ||
f8f6d679 DB |
459 | case BPF_JMP | BPF_JA: |
460 | target = i + fp->k + 1; | |
461 | insn->code = fp->code; | |
462 | BPF_EMIT_JMP; | |
bd4cf0ed AS |
463 | break; |
464 | ||
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 | |
476 | * in compare insn. | |
477 | */ | |
f8f6d679 | 478 | *insn++ = BPF_MOV32_IMM(BPF_REG_TMP, fp->k); |
bd4cf0ed | 479 | |
e430f34e AS |
480 | insn->dst_reg = BPF_REG_A; |
481 | insn->src_reg = BPF_REG_TMP; | |
bd4cf0ed AS |
482 | bpf_src = BPF_X; |
483 | } else { | |
e430f34e | 484 | insn->dst_reg = BPF_REG_A; |
bd4cf0ed AS |
485 | insn->imm = fp->k; |
486 | bpf_src = BPF_SRC(fp->code); | |
19539ce7 | 487 | insn->src_reg = bpf_src == BPF_X ? BPF_REG_X : 0; |
1da177e4 | 488 | } |
bd4cf0ed AS |
489 | |
490 | /* Common case where 'jump_false' is next insn. */ | |
491 | if (fp->jf == 0) { | |
492 | insn->code = BPF_JMP | BPF_OP(fp->code) | bpf_src; | |
493 | target = i + fp->jt + 1; | |
f8f6d679 | 494 | BPF_EMIT_JMP; |
bd4cf0ed | 495 | break; |
1da177e4 | 496 | } |
bd4cf0ed AS |
497 | |
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; | |
f8f6d679 | 502 | BPF_EMIT_JMP; |
bd4cf0ed | 503 | break; |
0b05b2a4 | 504 | } |
bd4cf0ed AS |
505 | |
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; | |
f8f6d679 | 509 | BPF_EMIT_JMP; |
bd4cf0ed AS |
510 | insn++; |
511 | ||
512 | insn->code = BPF_JMP | BPF_JA; | |
513 | target = i + fp->jf + 1; | |
f8f6d679 | 514 | BPF_EMIT_JMP; |
bd4cf0ed AS |
515 | break; |
516 | ||
517 | /* ldxb 4 * ([14] & 0xf) is remaped into 6 insns. */ | |
518 | case BPF_LDX | BPF_MSH | BPF_B: | |
9739eef1 | 519 | /* tmp = A */ |
f8f6d679 | 520 | *insn++ = BPF_MOV64_REG(BPF_REG_TMP, BPF_REG_A); |
1268e253 | 521 | /* A = BPF_R0 = *(u8 *) (skb->data + K) */ |
f8f6d679 | 522 | *insn++ = BPF_LD_ABS(BPF_B, fp->k); |
9739eef1 | 523 | /* A &= 0xf */ |
f8f6d679 | 524 | *insn++ = BPF_ALU32_IMM(BPF_AND, BPF_REG_A, 0xf); |
9739eef1 | 525 | /* A <<= 2 */ |
f8f6d679 | 526 | *insn++ = BPF_ALU32_IMM(BPF_LSH, BPF_REG_A, 2); |
9739eef1 | 527 | /* X = A */ |
f8f6d679 | 528 | *insn++ = BPF_MOV64_REG(BPF_REG_X, BPF_REG_A); |
9739eef1 | 529 | /* A = tmp */ |
f8f6d679 | 530 | *insn = BPF_MOV64_REG(BPF_REG_A, BPF_REG_TMP); |
bd4cf0ed AS |
531 | break; |
532 | ||
533 | /* RET_K, RET_A are remaped into 2 insns. */ | |
534 | case BPF_RET | BPF_A: | |
535 | case BPF_RET | BPF_K: | |
f8f6d679 DB |
536 | *insn++ = BPF_MOV32_RAW(BPF_RVAL(fp->code) == BPF_K ? |
537 | BPF_K : BPF_X, BPF_REG_0, | |
538 | BPF_REG_A, fp->k); | |
9739eef1 | 539 | *insn = BPF_EXIT_INSN(); |
bd4cf0ed AS |
540 | break; |
541 | ||
542 | /* Store to stack. */ | |
543 | case BPF_ST: | |
544 | case BPF_STX: | |
f8f6d679 DB |
545 | *insn = BPF_STX_MEM(BPF_W, BPF_REG_FP, BPF_CLASS(fp->code) == |
546 | BPF_ST ? BPF_REG_A : BPF_REG_X, | |
547 | -(BPF_MEMWORDS - fp->k) * 4); | |
bd4cf0ed AS |
548 | break; |
549 | ||
550 | /* Load from stack. */ | |
551 | case BPF_LD | BPF_MEM: | |
552 | case BPF_LDX | BPF_MEM: | |
f8f6d679 DB |
553 | *insn = BPF_LDX_MEM(BPF_W, BPF_CLASS(fp->code) == BPF_LD ? |
554 | BPF_REG_A : BPF_REG_X, BPF_REG_FP, | |
555 | -(BPF_MEMWORDS - fp->k) * 4); | |
bd4cf0ed AS |
556 | break; |
557 | ||
558 | /* A = K or X = K */ | |
559 | case BPF_LD | BPF_IMM: | |
560 | case BPF_LDX | BPF_IMM: | |
f8f6d679 DB |
561 | *insn = BPF_MOV32_IMM(BPF_CLASS(fp->code) == BPF_LD ? |
562 | BPF_REG_A : BPF_REG_X, fp->k); | |
bd4cf0ed AS |
563 | break; |
564 | ||
565 | /* X = A */ | |
566 | case BPF_MISC | BPF_TAX: | |
f8f6d679 | 567 | *insn = BPF_MOV64_REG(BPF_REG_X, BPF_REG_A); |
bd4cf0ed AS |
568 | break; |
569 | ||
570 | /* A = X */ | |
571 | case BPF_MISC | BPF_TXA: | |
f8f6d679 | 572 | *insn = BPF_MOV64_REG(BPF_REG_A, BPF_REG_X); |
bd4cf0ed AS |
573 | break; |
574 | ||
575 | /* A = skb->len or X = skb->len */ | |
576 | case BPF_LD | BPF_W | BPF_LEN: | |
577 | case BPF_LDX | BPF_W | BPF_LEN: | |
f8f6d679 DB |
578 | *insn = BPF_LDX_MEM(BPF_W, BPF_CLASS(fp->code) == BPF_LD ? |
579 | BPF_REG_A : BPF_REG_X, BPF_REG_CTX, | |
580 | offsetof(struct sk_buff, len)); | |
bd4cf0ed AS |
581 | break; |
582 | ||
f8f6d679 | 583 | /* Access seccomp_data fields. */ |
bd4cf0ed | 584 | case BPF_LDX | BPF_ABS | BPF_W: |
9739eef1 AS |
585 | /* A = *(u32 *) (ctx + K) */ |
586 | *insn = BPF_LDX_MEM(BPF_W, BPF_REG_A, BPF_REG_CTX, fp->k); | |
bd4cf0ed AS |
587 | break; |
588 | ||
ca9f1fd2 | 589 | /* Unknown instruction. */ |
1da177e4 | 590 | default: |
bd4cf0ed | 591 | goto err; |
1da177e4 | 592 | } |
bd4cf0ed AS |
593 | |
594 | insn++; | |
595 | if (new_prog) | |
596 | memcpy(new_insn, tmp_insns, | |
597 | sizeof(*insn) * (insn - tmp_insns)); | |
bd4cf0ed | 598 | new_insn += insn - tmp_insns; |
1da177e4 LT |
599 | } |
600 | ||
bd4cf0ed AS |
601 | if (!new_prog) { |
602 | /* Only calculating new length. */ | |
603 | *new_len = new_insn - new_prog; | |
604 | return 0; | |
605 | } | |
606 | ||
607 | pass++; | |
608 | if (new_flen != new_insn - new_prog) { | |
609 | new_flen = new_insn - new_prog; | |
610 | if (pass > 2) | |
611 | goto err; | |
bd4cf0ed AS |
612 | goto do_pass; |
613 | } | |
614 | ||
615 | kfree(addrs); | |
616 | BUG_ON(*new_len != new_flen); | |
1da177e4 | 617 | return 0; |
bd4cf0ed AS |
618 | err: |
619 | kfree(addrs); | |
620 | return -EINVAL; | |
1da177e4 LT |
621 | } |
622 | ||
bd4cf0ed | 623 | /* Security: |
bd4cf0ed | 624 | * |
2d5311e4 | 625 | * As we dont want to clear mem[] array for each packet going through |
8ea6e345 | 626 | * __bpf_prog_run(), we check that filter loaded by user never try to read |
2d5311e4 | 627 | * a cell if not previously written, and we check all branches to be sure |
25985edc | 628 | * a malicious user doesn't try to abuse us. |
2d5311e4 | 629 | */ |
ec31a05c | 630 | static int check_load_and_stores(const struct sock_filter *filter, int flen) |
2d5311e4 | 631 | { |
34805931 | 632 | u16 *masks, memvalid = 0; /* One bit per cell, 16 cells */ |
2d5311e4 ED |
633 | int pc, ret = 0; |
634 | ||
635 | BUILD_BUG_ON(BPF_MEMWORDS > 16); | |
34805931 | 636 | |
99e72a0f | 637 | masks = kmalloc_array(flen, sizeof(*masks), GFP_KERNEL); |
2d5311e4 ED |
638 | if (!masks) |
639 | return -ENOMEM; | |
34805931 | 640 | |
2d5311e4 ED |
641 | memset(masks, 0xff, flen * sizeof(*masks)); |
642 | ||
643 | for (pc = 0; pc < flen; pc++) { | |
644 | memvalid &= masks[pc]; | |
645 | ||
646 | switch (filter[pc].code) { | |
34805931 DB |
647 | case BPF_ST: |
648 | case BPF_STX: | |
2d5311e4 ED |
649 | memvalid |= (1 << filter[pc].k); |
650 | break; | |
34805931 DB |
651 | case BPF_LD | BPF_MEM: |
652 | case BPF_LDX | BPF_MEM: | |
2d5311e4 ED |
653 | if (!(memvalid & (1 << filter[pc].k))) { |
654 | ret = -EINVAL; | |
655 | goto error; | |
656 | } | |
657 | break; | |
34805931 DB |
658 | case BPF_JMP | BPF_JA: |
659 | /* A jump must set masks on target */ | |
2d5311e4 ED |
660 | masks[pc + 1 + filter[pc].k] &= memvalid; |
661 | memvalid = ~0; | |
662 | break; | |
34805931 DB |
663 | case BPF_JMP | BPF_JEQ | BPF_K: |
664 | case BPF_JMP | BPF_JEQ | BPF_X: | |
665 | case BPF_JMP | BPF_JGE | BPF_K: | |
666 | case BPF_JMP | BPF_JGE | BPF_X: | |
667 | case BPF_JMP | BPF_JGT | BPF_K: | |
668 | case BPF_JMP | BPF_JGT | BPF_X: | |
669 | case BPF_JMP | BPF_JSET | BPF_K: | |
670 | case BPF_JMP | BPF_JSET | BPF_X: | |
671 | /* A jump must set masks on targets */ | |
2d5311e4 ED |
672 | masks[pc + 1 + filter[pc].jt] &= memvalid; |
673 | masks[pc + 1 + filter[pc].jf] &= memvalid; | |
674 | memvalid = ~0; | |
675 | break; | |
676 | } | |
677 | } | |
678 | error: | |
679 | kfree(masks); | |
680 | return ret; | |
681 | } | |
682 | ||
34805931 DB |
683 | static bool chk_code_allowed(u16 code_to_probe) |
684 | { | |
685 | static const bool codes[] = { | |
686 | /* 32 bit ALU operations */ | |
687 | [BPF_ALU | BPF_ADD | BPF_K] = true, | |
688 | [BPF_ALU | BPF_ADD | BPF_X] = true, | |
689 | [BPF_ALU | BPF_SUB | BPF_K] = true, | |
690 | [BPF_ALU | BPF_SUB | BPF_X] = true, | |
691 | [BPF_ALU | BPF_MUL | BPF_K] = true, | |
692 | [BPF_ALU | BPF_MUL | BPF_X] = true, | |
693 | [BPF_ALU | BPF_DIV | BPF_K] = true, | |
694 | [BPF_ALU | BPF_DIV | BPF_X] = true, | |
695 | [BPF_ALU | BPF_MOD | BPF_K] = true, | |
696 | [BPF_ALU | BPF_MOD | BPF_X] = true, | |
697 | [BPF_ALU | BPF_AND | BPF_K] = true, | |
698 | [BPF_ALU | BPF_AND | BPF_X] = true, | |
699 | [BPF_ALU | BPF_OR | BPF_K] = true, | |
700 | [BPF_ALU | BPF_OR | BPF_X] = true, | |
701 | [BPF_ALU | BPF_XOR | BPF_K] = true, | |
702 | [BPF_ALU | BPF_XOR | BPF_X] = true, | |
703 | [BPF_ALU | BPF_LSH | BPF_K] = true, | |
704 | [BPF_ALU | BPF_LSH | BPF_X] = true, | |
705 | [BPF_ALU | BPF_RSH | BPF_K] = true, | |
706 | [BPF_ALU | BPF_RSH | BPF_X] = true, | |
707 | [BPF_ALU | BPF_NEG] = true, | |
708 | /* Load instructions */ | |
709 | [BPF_LD | BPF_W | BPF_ABS] = true, | |
710 | [BPF_LD | BPF_H | BPF_ABS] = true, | |
711 | [BPF_LD | BPF_B | BPF_ABS] = true, | |
712 | [BPF_LD | BPF_W | BPF_LEN] = true, | |
713 | [BPF_LD | BPF_W | BPF_IND] = true, | |
714 | [BPF_LD | BPF_H | BPF_IND] = true, | |
715 | [BPF_LD | BPF_B | BPF_IND] = true, | |
716 | [BPF_LD | BPF_IMM] = true, | |
717 | [BPF_LD | BPF_MEM] = true, | |
718 | [BPF_LDX | BPF_W | BPF_LEN] = true, | |
719 | [BPF_LDX | BPF_B | BPF_MSH] = true, | |
720 | [BPF_LDX | BPF_IMM] = true, | |
721 | [BPF_LDX | BPF_MEM] = true, | |
722 | /* Store instructions */ | |
723 | [BPF_ST] = true, | |
724 | [BPF_STX] = true, | |
725 | /* Misc instructions */ | |
726 | [BPF_MISC | BPF_TAX] = true, | |
727 | [BPF_MISC | BPF_TXA] = true, | |
728 | /* Return instructions */ | |
729 | [BPF_RET | BPF_K] = true, | |
730 | [BPF_RET | BPF_A] = true, | |
731 | /* Jump instructions */ | |
732 | [BPF_JMP | BPF_JA] = true, | |
733 | [BPF_JMP | BPF_JEQ | BPF_K] = true, | |
734 | [BPF_JMP | BPF_JEQ | BPF_X] = true, | |
735 | [BPF_JMP | BPF_JGE | BPF_K] = true, | |
736 | [BPF_JMP | BPF_JGE | BPF_X] = true, | |
737 | [BPF_JMP | BPF_JGT | BPF_K] = true, | |
738 | [BPF_JMP | BPF_JGT | BPF_X] = true, | |
739 | [BPF_JMP | BPF_JSET | BPF_K] = true, | |
740 | [BPF_JMP | BPF_JSET | BPF_X] = true, | |
741 | }; | |
742 | ||
743 | if (code_to_probe >= ARRAY_SIZE(codes)) | |
744 | return false; | |
745 | ||
746 | return codes[code_to_probe]; | |
747 | } | |
748 | ||
1da177e4 | 749 | /** |
4df95ff4 | 750 | * bpf_check_classic - verify socket filter code |
1da177e4 LT |
751 | * @filter: filter to verify |
752 | * @flen: length of filter | |
753 | * | |
754 | * Check the user's filter code. If we let some ugly | |
755 | * filter code slip through kaboom! The filter must contain | |
93699863 KK |
756 | * no references or jumps that are out of range, no illegal |
757 | * instructions, and must end with a RET instruction. | |
1da177e4 | 758 | * |
7b11f69f KK |
759 | * All jumps are forward as they are not signed. |
760 | * | |
761 | * Returns 0 if the rule set is legal or -EINVAL if not. | |
1da177e4 | 762 | */ |
d9e12f42 NS |
763 | static int bpf_check_classic(const struct sock_filter *filter, |
764 | unsigned int flen) | |
1da177e4 | 765 | { |
aa1113d9 | 766 | bool anc_found; |
34805931 | 767 | int pc; |
1da177e4 | 768 | |
1b93ae64 | 769 | if (flen == 0 || flen > BPF_MAXINSNS) |
1da177e4 LT |
770 | return -EINVAL; |
771 | ||
34805931 | 772 | /* Check the filter code now */ |
1da177e4 | 773 | for (pc = 0; pc < flen; pc++) { |
ec31a05c | 774 | const struct sock_filter *ftest = &filter[pc]; |
93699863 | 775 | |
34805931 DB |
776 | /* May we actually operate on this code? */ |
777 | if (!chk_code_allowed(ftest->code)) | |
cba328fc | 778 | return -EINVAL; |
34805931 | 779 | |
93699863 | 780 | /* Some instructions need special checks */ |
34805931 DB |
781 | switch (ftest->code) { |
782 | case BPF_ALU | BPF_DIV | BPF_K: | |
783 | case BPF_ALU | BPF_MOD | BPF_K: | |
784 | /* Check for division by zero */ | |
b6069a95 ED |
785 | if (ftest->k == 0) |
786 | return -EINVAL; | |
787 | break; | |
229394e8 RV |
788 | case BPF_ALU | BPF_LSH | BPF_K: |
789 | case BPF_ALU | BPF_RSH | BPF_K: | |
790 | if (ftest->k >= 32) | |
791 | return -EINVAL; | |
792 | break; | |
34805931 DB |
793 | case BPF_LD | BPF_MEM: |
794 | case BPF_LDX | BPF_MEM: | |
795 | case BPF_ST: | |
796 | case BPF_STX: | |
797 | /* Check for invalid memory addresses */ | |
93699863 KK |
798 | if (ftest->k >= BPF_MEMWORDS) |
799 | return -EINVAL; | |
800 | break; | |
34805931 DB |
801 | case BPF_JMP | BPF_JA: |
802 | /* Note, the large ftest->k might cause loops. | |
93699863 KK |
803 | * Compare this with conditional jumps below, |
804 | * where offsets are limited. --ANK (981016) | |
805 | */ | |
34805931 | 806 | if (ftest->k >= (unsigned int)(flen - pc - 1)) |
93699863 | 807 | return -EINVAL; |
01f2f3f6 | 808 | break; |
34805931 DB |
809 | case BPF_JMP | BPF_JEQ | BPF_K: |
810 | case BPF_JMP | BPF_JEQ | BPF_X: | |
811 | case BPF_JMP | BPF_JGE | BPF_K: | |
812 | case BPF_JMP | BPF_JGE | BPF_X: | |
813 | case BPF_JMP | BPF_JGT | BPF_K: | |
814 | case BPF_JMP | BPF_JGT | BPF_X: | |
815 | case BPF_JMP | BPF_JSET | BPF_K: | |
816 | case BPF_JMP | BPF_JSET | BPF_X: | |
817 | /* Both conditionals must be safe */ | |
e35bedf3 | 818 | if (pc + ftest->jt + 1 >= flen || |
93699863 KK |
819 | pc + ftest->jf + 1 >= flen) |
820 | return -EINVAL; | |
cba328fc | 821 | break; |
34805931 DB |
822 | case BPF_LD | BPF_W | BPF_ABS: |
823 | case BPF_LD | BPF_H | BPF_ABS: | |
824 | case BPF_LD | BPF_B | BPF_ABS: | |
aa1113d9 | 825 | anc_found = false; |
34805931 DB |
826 | if (bpf_anc_helper(ftest) & BPF_ANC) |
827 | anc_found = true; | |
828 | /* Ancillary operation unknown or unsupported */ | |
aa1113d9 DB |
829 | if (anc_found == false && ftest->k >= SKF_AD_OFF) |
830 | return -EINVAL; | |
01f2f3f6 HPP |
831 | } |
832 | } | |
93699863 | 833 | |
34805931 | 834 | /* Last instruction must be a RET code */ |
01f2f3f6 | 835 | switch (filter[flen - 1].code) { |
34805931 DB |
836 | case BPF_RET | BPF_K: |
837 | case BPF_RET | BPF_A: | |
2d5311e4 | 838 | return check_load_and_stores(filter, flen); |
cba328fc | 839 | } |
34805931 | 840 | |
cba328fc | 841 | return -EINVAL; |
1da177e4 LT |
842 | } |
843 | ||
7ae457c1 AS |
844 | static int bpf_prog_store_orig_filter(struct bpf_prog *fp, |
845 | const struct sock_fprog *fprog) | |
a3ea269b | 846 | { |
009937e7 | 847 | unsigned int fsize = bpf_classic_proglen(fprog); |
a3ea269b DB |
848 | struct sock_fprog_kern *fkprog; |
849 | ||
850 | fp->orig_prog = kmalloc(sizeof(*fkprog), GFP_KERNEL); | |
851 | if (!fp->orig_prog) | |
852 | return -ENOMEM; | |
853 | ||
854 | fkprog = fp->orig_prog; | |
855 | fkprog->len = fprog->len; | |
658da937 DB |
856 | |
857 | fkprog->filter = kmemdup(fp->insns, fsize, | |
858 | GFP_KERNEL | __GFP_NOWARN); | |
a3ea269b DB |
859 | if (!fkprog->filter) { |
860 | kfree(fp->orig_prog); | |
861 | return -ENOMEM; | |
862 | } | |
863 | ||
864 | return 0; | |
865 | } | |
866 | ||
7ae457c1 | 867 | static void bpf_release_orig_filter(struct bpf_prog *fp) |
a3ea269b DB |
868 | { |
869 | struct sock_fprog_kern *fprog = fp->orig_prog; | |
870 | ||
871 | if (fprog) { | |
872 | kfree(fprog->filter); | |
873 | kfree(fprog); | |
874 | } | |
875 | } | |
876 | ||
7ae457c1 AS |
877 | static void __bpf_prog_release(struct bpf_prog *prog) |
878 | { | |
24701ece | 879 | if (prog->type == BPF_PROG_TYPE_SOCKET_FILTER) { |
89aa0758 AS |
880 | bpf_prog_put(prog); |
881 | } else { | |
882 | bpf_release_orig_filter(prog); | |
883 | bpf_prog_free(prog); | |
884 | } | |
7ae457c1 AS |
885 | } |
886 | ||
34c5bd66 PN |
887 | static void __sk_filter_release(struct sk_filter *fp) |
888 | { | |
7ae457c1 AS |
889 | __bpf_prog_release(fp->prog); |
890 | kfree(fp); | |
34c5bd66 PN |
891 | } |
892 | ||
47e958ea | 893 | /** |
46bcf14f | 894 | * sk_filter_release_rcu - Release a socket filter by rcu_head |
47e958ea PE |
895 | * @rcu: rcu_head that contains the sk_filter to free |
896 | */ | |
fbc907f0 | 897 | static void sk_filter_release_rcu(struct rcu_head *rcu) |
47e958ea PE |
898 | { |
899 | struct sk_filter *fp = container_of(rcu, struct sk_filter, rcu); | |
900 | ||
34c5bd66 | 901 | __sk_filter_release(fp); |
47e958ea | 902 | } |
fbc907f0 DB |
903 | |
904 | /** | |
905 | * sk_filter_release - release a socket filter | |
906 | * @fp: filter to remove | |
907 | * | |
908 | * Remove a filter from a socket and release its resources. | |
909 | */ | |
910 | static void sk_filter_release(struct sk_filter *fp) | |
911 | { | |
912 | if (atomic_dec_and_test(&fp->refcnt)) | |
913 | call_rcu(&fp->rcu, sk_filter_release_rcu); | |
914 | } | |
915 | ||
916 | void sk_filter_uncharge(struct sock *sk, struct sk_filter *fp) | |
917 | { | |
7ae457c1 | 918 | u32 filter_size = bpf_prog_size(fp->prog->len); |
fbc907f0 | 919 | |
278571ba AS |
920 | atomic_sub(filter_size, &sk->sk_omem_alloc); |
921 | sk_filter_release(fp); | |
fbc907f0 | 922 | } |
47e958ea | 923 | |
278571ba AS |
924 | /* try to charge the socket memory if there is space available |
925 | * return true on success | |
926 | */ | |
927 | bool sk_filter_charge(struct sock *sk, struct sk_filter *fp) | |
bd4cf0ed | 928 | { |
7ae457c1 | 929 | u32 filter_size = bpf_prog_size(fp->prog->len); |
278571ba AS |
930 | |
931 | /* same check as in sock_kmalloc() */ | |
932 | if (filter_size <= sysctl_optmem_max && | |
933 | atomic_read(&sk->sk_omem_alloc) + filter_size < sysctl_optmem_max) { | |
934 | atomic_inc(&fp->refcnt); | |
935 | atomic_add(filter_size, &sk->sk_omem_alloc); | |
936 | return true; | |
bd4cf0ed | 937 | } |
278571ba | 938 | return false; |
bd4cf0ed AS |
939 | } |
940 | ||
7ae457c1 | 941 | static struct bpf_prog *bpf_migrate_filter(struct bpf_prog *fp) |
bd4cf0ed AS |
942 | { |
943 | struct sock_filter *old_prog; | |
7ae457c1 | 944 | struct bpf_prog *old_fp; |
34805931 | 945 | int err, new_len, old_len = fp->len; |
bd4cf0ed AS |
946 | |
947 | /* We are free to overwrite insns et al right here as it | |
948 | * won't be used at this point in time anymore internally | |
949 | * after the migration to the internal BPF instruction | |
950 | * representation. | |
951 | */ | |
952 | BUILD_BUG_ON(sizeof(struct sock_filter) != | |
2695fb55 | 953 | sizeof(struct bpf_insn)); |
bd4cf0ed | 954 | |
bd4cf0ed AS |
955 | /* Conversion cannot happen on overlapping memory areas, |
956 | * so we need to keep the user BPF around until the 2nd | |
957 | * pass. At this time, the user BPF is stored in fp->insns. | |
958 | */ | |
959 | old_prog = kmemdup(fp->insns, old_len * sizeof(struct sock_filter), | |
658da937 | 960 | GFP_KERNEL | __GFP_NOWARN); |
bd4cf0ed AS |
961 | if (!old_prog) { |
962 | err = -ENOMEM; | |
963 | goto out_err; | |
964 | } | |
965 | ||
966 | /* 1st pass: calculate the new program length. */ | |
8fb575ca | 967 | err = bpf_convert_filter(old_prog, old_len, NULL, &new_len); |
bd4cf0ed AS |
968 | if (err) |
969 | goto out_err_free; | |
970 | ||
971 | /* Expand fp for appending the new filter representation. */ | |
972 | old_fp = fp; | |
60a3b225 | 973 | fp = bpf_prog_realloc(old_fp, bpf_prog_size(new_len), 0); |
bd4cf0ed AS |
974 | if (!fp) { |
975 | /* The old_fp is still around in case we couldn't | |
976 | * allocate new memory, so uncharge on that one. | |
977 | */ | |
978 | fp = old_fp; | |
979 | err = -ENOMEM; | |
980 | goto out_err_free; | |
981 | } | |
982 | ||
bd4cf0ed AS |
983 | fp->len = new_len; |
984 | ||
2695fb55 | 985 | /* 2nd pass: remap sock_filter insns into bpf_insn insns. */ |
8fb575ca | 986 | err = bpf_convert_filter(old_prog, old_len, fp->insnsi, &new_len); |
bd4cf0ed | 987 | if (err) |
8fb575ca | 988 | /* 2nd bpf_convert_filter() can fail only if it fails |
bd4cf0ed AS |
989 | * to allocate memory, remapping must succeed. Note, |
990 | * that at this time old_fp has already been released | |
278571ba | 991 | * by krealloc(). |
bd4cf0ed AS |
992 | */ |
993 | goto out_err_free; | |
994 | ||
7ae457c1 | 995 | bpf_prog_select_runtime(fp); |
5fe821a9 | 996 | |
bd4cf0ed AS |
997 | kfree(old_prog); |
998 | return fp; | |
999 | ||
1000 | out_err_free: | |
1001 | kfree(old_prog); | |
1002 | out_err: | |
7ae457c1 | 1003 | __bpf_prog_release(fp); |
bd4cf0ed AS |
1004 | return ERR_PTR(err); |
1005 | } | |
1006 | ||
ac67eb2c DB |
1007 | static struct bpf_prog *bpf_prepare_filter(struct bpf_prog *fp, |
1008 | bpf_aux_classic_check_t trans) | |
302d6637 JP |
1009 | { |
1010 | int err; | |
1011 | ||
bd4cf0ed | 1012 | fp->bpf_func = NULL; |
a91263d5 | 1013 | fp->jited = 0; |
302d6637 | 1014 | |
4df95ff4 | 1015 | err = bpf_check_classic(fp->insns, fp->len); |
418c96ac | 1016 | if (err) { |
7ae457c1 | 1017 | __bpf_prog_release(fp); |
bd4cf0ed | 1018 | return ERR_PTR(err); |
418c96ac | 1019 | } |
302d6637 | 1020 | |
4ae92bc7 NS |
1021 | /* There might be additional checks and transformations |
1022 | * needed on classic filters, f.e. in case of seccomp. | |
1023 | */ | |
1024 | if (trans) { | |
1025 | err = trans(fp->insns, fp->len); | |
1026 | if (err) { | |
1027 | __bpf_prog_release(fp); | |
1028 | return ERR_PTR(err); | |
1029 | } | |
1030 | } | |
1031 | ||
bd4cf0ed AS |
1032 | /* Probe if we can JIT compile the filter and if so, do |
1033 | * the compilation of the filter. | |
1034 | */ | |
302d6637 | 1035 | bpf_jit_compile(fp); |
bd4cf0ed AS |
1036 | |
1037 | /* JIT compiler couldn't process this filter, so do the | |
1038 | * internal BPF translation for the optimized interpreter. | |
1039 | */ | |
5fe821a9 | 1040 | if (!fp->jited) |
7ae457c1 | 1041 | fp = bpf_migrate_filter(fp); |
bd4cf0ed AS |
1042 | |
1043 | return fp; | |
302d6637 JP |
1044 | } |
1045 | ||
1046 | /** | |
7ae457c1 | 1047 | * bpf_prog_create - create an unattached filter |
c6c4b97c | 1048 | * @pfp: the unattached filter that is created |
677a9fd3 | 1049 | * @fprog: the filter program |
302d6637 | 1050 | * |
c6c4b97c | 1051 | * Create a filter independent of any socket. We first run some |
302d6637 JP |
1052 | * sanity checks on it to make sure it does not explode on us later. |
1053 | * If an error occurs or there is insufficient memory for the filter | |
1054 | * a negative errno code is returned. On success the return is zero. | |
1055 | */ | |
7ae457c1 | 1056 | int bpf_prog_create(struct bpf_prog **pfp, struct sock_fprog_kern *fprog) |
302d6637 | 1057 | { |
009937e7 | 1058 | unsigned int fsize = bpf_classic_proglen(fprog); |
7ae457c1 | 1059 | struct bpf_prog *fp; |
302d6637 JP |
1060 | |
1061 | /* Make sure new filter is there and in the right amounts. */ | |
1062 | if (fprog->filter == NULL) | |
1063 | return -EINVAL; | |
1064 | ||
60a3b225 | 1065 | fp = bpf_prog_alloc(bpf_prog_size(fprog->len), 0); |
302d6637 JP |
1066 | if (!fp) |
1067 | return -ENOMEM; | |
a3ea269b | 1068 | |
302d6637 JP |
1069 | memcpy(fp->insns, fprog->filter, fsize); |
1070 | ||
302d6637 | 1071 | fp->len = fprog->len; |
a3ea269b DB |
1072 | /* Since unattached filters are not copied back to user |
1073 | * space through sk_get_filter(), we do not need to hold | |
1074 | * a copy here, and can spare us the work. | |
1075 | */ | |
1076 | fp->orig_prog = NULL; | |
302d6637 | 1077 | |
7ae457c1 | 1078 | /* bpf_prepare_filter() already takes care of freeing |
bd4cf0ed AS |
1079 | * memory in case something goes wrong. |
1080 | */ | |
4ae92bc7 | 1081 | fp = bpf_prepare_filter(fp, NULL); |
bd4cf0ed AS |
1082 | if (IS_ERR(fp)) |
1083 | return PTR_ERR(fp); | |
302d6637 JP |
1084 | |
1085 | *pfp = fp; | |
1086 | return 0; | |
302d6637 | 1087 | } |
7ae457c1 | 1088 | EXPORT_SYMBOL_GPL(bpf_prog_create); |
302d6637 | 1089 | |
ac67eb2c DB |
1090 | /** |
1091 | * bpf_prog_create_from_user - create an unattached filter from user buffer | |
1092 | * @pfp: the unattached filter that is created | |
1093 | * @fprog: the filter program | |
1094 | * @trans: post-classic verifier transformation handler | |
bab18991 | 1095 | * @save_orig: save classic BPF program |
ac67eb2c DB |
1096 | * |
1097 | * This function effectively does the same as bpf_prog_create(), only | |
1098 | * that it builds up its insns buffer from user space provided buffer. | |
1099 | * It also allows for passing a bpf_aux_classic_check_t handler. | |
1100 | */ | |
1101 | int bpf_prog_create_from_user(struct bpf_prog **pfp, struct sock_fprog *fprog, | |
bab18991 | 1102 | bpf_aux_classic_check_t trans, bool save_orig) |
ac67eb2c DB |
1103 | { |
1104 | unsigned int fsize = bpf_classic_proglen(fprog); | |
1105 | struct bpf_prog *fp; | |
bab18991 | 1106 | int err; |
ac67eb2c DB |
1107 | |
1108 | /* Make sure new filter is there and in the right amounts. */ | |
1109 | if (fprog->filter == NULL) | |
1110 | return -EINVAL; | |
1111 | ||
1112 | fp = bpf_prog_alloc(bpf_prog_size(fprog->len), 0); | |
1113 | if (!fp) | |
1114 | return -ENOMEM; | |
1115 | ||
1116 | if (copy_from_user(fp->insns, fprog->filter, fsize)) { | |
1117 | __bpf_prog_free(fp); | |
1118 | return -EFAULT; | |
1119 | } | |
1120 | ||
1121 | fp->len = fprog->len; | |
ac67eb2c DB |
1122 | fp->orig_prog = NULL; |
1123 | ||
bab18991 DB |
1124 | if (save_orig) { |
1125 | err = bpf_prog_store_orig_filter(fp, fprog); | |
1126 | if (err) { | |
1127 | __bpf_prog_free(fp); | |
1128 | return -ENOMEM; | |
1129 | } | |
1130 | } | |
1131 | ||
ac67eb2c DB |
1132 | /* bpf_prepare_filter() already takes care of freeing |
1133 | * memory in case something goes wrong. | |
1134 | */ | |
1135 | fp = bpf_prepare_filter(fp, trans); | |
1136 | if (IS_ERR(fp)) | |
1137 | return PTR_ERR(fp); | |
1138 | ||
1139 | *pfp = fp; | |
1140 | return 0; | |
1141 | } | |
2ea273d7 | 1142 | EXPORT_SYMBOL_GPL(bpf_prog_create_from_user); |
ac67eb2c | 1143 | |
7ae457c1 | 1144 | void bpf_prog_destroy(struct bpf_prog *fp) |
302d6637 | 1145 | { |
7ae457c1 | 1146 | __bpf_prog_release(fp); |
302d6637 | 1147 | } |
7ae457c1 | 1148 | EXPORT_SYMBOL_GPL(bpf_prog_destroy); |
302d6637 | 1149 | |
49b31e57 DB |
1150 | static int __sk_attach_prog(struct bpf_prog *prog, struct sock *sk) |
1151 | { | |
1152 | struct sk_filter *fp, *old_fp; | |
1153 | ||
1154 | fp = kmalloc(sizeof(*fp), GFP_KERNEL); | |
1155 | if (!fp) | |
1156 | return -ENOMEM; | |
1157 | ||
1158 | fp->prog = prog; | |
1159 | atomic_set(&fp->refcnt, 0); | |
1160 | ||
1161 | if (!sk_filter_charge(sk, fp)) { | |
1162 | kfree(fp); | |
1163 | return -ENOMEM; | |
1164 | } | |
1165 | ||
1166 | old_fp = rcu_dereference_protected(sk->sk_filter, | |
1167 | sock_owned_by_user(sk)); | |
1168 | rcu_assign_pointer(sk->sk_filter, fp); | |
1169 | ||
1170 | if (old_fp) | |
1171 | sk_filter_uncharge(sk, old_fp); | |
1172 | ||
1173 | return 0; | |
1174 | } | |
1175 | ||
538950a1 CG |
1176 | static int __reuseport_attach_prog(struct bpf_prog *prog, struct sock *sk) |
1177 | { | |
1178 | struct bpf_prog *old_prog; | |
1179 | int err; | |
1180 | ||
1181 | if (bpf_prog_size(prog->len) > sysctl_optmem_max) | |
1182 | return -ENOMEM; | |
1183 | ||
1184 | if (sk_unhashed(sk)) { | |
1185 | err = reuseport_alloc(sk); | |
1186 | if (err) | |
1187 | return err; | |
1188 | } else if (!rcu_access_pointer(sk->sk_reuseport_cb)) { | |
1189 | /* The socket wasn't bound with SO_REUSEPORT */ | |
1190 | return -EINVAL; | |
1191 | } | |
1192 | ||
1193 | old_prog = reuseport_attach_prog(sk, prog); | |
1194 | if (old_prog) | |
1195 | bpf_prog_destroy(old_prog); | |
1196 | ||
1197 | return 0; | |
1198 | } | |
1199 | ||
1200 | static | |
1201 | struct bpf_prog *__get_filter(struct sock_fprog *fprog, struct sock *sk) | |
1da177e4 | 1202 | { |
009937e7 | 1203 | unsigned int fsize = bpf_classic_proglen(fprog); |
7ae457c1 AS |
1204 | unsigned int bpf_fsize = bpf_prog_size(fprog->len); |
1205 | struct bpf_prog *prog; | |
1da177e4 LT |
1206 | int err; |
1207 | ||
d59577b6 | 1208 | if (sock_flag(sk, SOCK_FILTER_LOCKED)) |
538950a1 | 1209 | return ERR_PTR(-EPERM); |
d59577b6 | 1210 | |
1da177e4 | 1211 | /* Make sure new filter is there and in the right amounts. */ |
e35bedf3 | 1212 | if (fprog->filter == NULL) |
538950a1 | 1213 | return ERR_PTR(-EINVAL); |
1da177e4 | 1214 | |
60a3b225 | 1215 | prog = bpf_prog_alloc(bpf_fsize, 0); |
7ae457c1 | 1216 | if (!prog) |
538950a1 | 1217 | return ERR_PTR(-ENOMEM); |
a3ea269b | 1218 | |
7ae457c1 | 1219 | if (copy_from_user(prog->insns, fprog->filter, fsize)) { |
c0d1379a | 1220 | __bpf_prog_free(prog); |
538950a1 | 1221 | return ERR_PTR(-EFAULT); |
1da177e4 LT |
1222 | } |
1223 | ||
7ae457c1 | 1224 | prog->len = fprog->len; |
1da177e4 | 1225 | |
7ae457c1 | 1226 | err = bpf_prog_store_orig_filter(prog, fprog); |
a3ea269b | 1227 | if (err) { |
c0d1379a | 1228 | __bpf_prog_free(prog); |
538950a1 | 1229 | return ERR_PTR(-ENOMEM); |
a3ea269b DB |
1230 | } |
1231 | ||
7ae457c1 | 1232 | /* bpf_prepare_filter() already takes care of freeing |
bd4cf0ed AS |
1233 | * memory in case something goes wrong. |
1234 | */ | |
538950a1 CG |
1235 | return bpf_prepare_filter(prog, NULL); |
1236 | } | |
1237 | ||
1238 | /** | |
1239 | * sk_attach_filter - attach a socket filter | |
1240 | * @fprog: the filter program | |
1241 | * @sk: the socket to use | |
1242 | * | |
1243 | * Attach the user's filter code. We first run some sanity checks on | |
1244 | * it to make sure it does not explode on us later. If an error | |
1245 | * occurs or there is insufficient memory for the filter a negative | |
1246 | * errno code is returned. On success the return is zero. | |
1247 | */ | |
1248 | int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk) | |
1249 | { | |
1250 | struct bpf_prog *prog = __get_filter(fprog, sk); | |
1251 | int err; | |
1252 | ||
7ae457c1 AS |
1253 | if (IS_ERR(prog)) |
1254 | return PTR_ERR(prog); | |
1255 | ||
49b31e57 DB |
1256 | err = __sk_attach_prog(prog, sk); |
1257 | if (err < 0) { | |
7ae457c1 | 1258 | __bpf_prog_release(prog); |
49b31e57 | 1259 | return err; |
278571ba AS |
1260 | } |
1261 | ||
d3904b73 | 1262 | return 0; |
1da177e4 | 1263 | } |
5ff3f073 | 1264 | EXPORT_SYMBOL_GPL(sk_attach_filter); |
1da177e4 | 1265 | |
538950a1 | 1266 | int sk_reuseport_attach_filter(struct sock_fprog *fprog, struct sock *sk) |
89aa0758 | 1267 | { |
538950a1 | 1268 | struct bpf_prog *prog = __get_filter(fprog, sk); |
49b31e57 | 1269 | int err; |
89aa0758 | 1270 | |
538950a1 CG |
1271 | if (IS_ERR(prog)) |
1272 | return PTR_ERR(prog); | |
1273 | ||
1274 | err = __reuseport_attach_prog(prog, sk); | |
1275 | if (err < 0) { | |
1276 | __bpf_prog_release(prog); | |
1277 | return err; | |
1278 | } | |
1279 | ||
1280 | return 0; | |
1281 | } | |
1282 | ||
1283 | static struct bpf_prog *__get_bpf(u32 ufd, struct sock *sk) | |
1284 | { | |
1285 | struct bpf_prog *prog; | |
1286 | ||
89aa0758 | 1287 | if (sock_flag(sk, SOCK_FILTER_LOCKED)) |
538950a1 | 1288 | return ERR_PTR(-EPERM); |
89aa0758 AS |
1289 | |
1290 | prog = bpf_prog_get(ufd); | |
198bf1b0 | 1291 | if (IS_ERR(prog)) |
538950a1 | 1292 | return prog; |
89aa0758 | 1293 | |
24701ece | 1294 | if (prog->type != BPF_PROG_TYPE_SOCKET_FILTER) { |
89aa0758 | 1295 | bpf_prog_put(prog); |
538950a1 | 1296 | return ERR_PTR(-EINVAL); |
89aa0758 AS |
1297 | } |
1298 | ||
538950a1 CG |
1299 | return prog; |
1300 | } | |
1301 | ||
1302 | int sk_attach_bpf(u32 ufd, struct sock *sk) | |
1303 | { | |
1304 | struct bpf_prog *prog = __get_bpf(ufd, sk); | |
1305 | int err; | |
1306 | ||
1307 | if (IS_ERR(prog)) | |
1308 | return PTR_ERR(prog); | |
1309 | ||
49b31e57 DB |
1310 | err = __sk_attach_prog(prog, sk); |
1311 | if (err < 0) { | |
89aa0758 | 1312 | bpf_prog_put(prog); |
49b31e57 | 1313 | return err; |
89aa0758 AS |
1314 | } |
1315 | ||
89aa0758 AS |
1316 | return 0; |
1317 | } | |
1318 | ||
538950a1 CG |
1319 | int sk_reuseport_attach_bpf(u32 ufd, struct sock *sk) |
1320 | { | |
1321 | struct bpf_prog *prog = __get_bpf(ufd, sk); | |
1322 | int err; | |
1323 | ||
1324 | if (IS_ERR(prog)) | |
1325 | return PTR_ERR(prog); | |
1326 | ||
1327 | err = __reuseport_attach_prog(prog, sk); | |
1328 | if (err < 0) { | |
1329 | bpf_prog_put(prog); | |
1330 | return err; | |
1331 | } | |
1332 | ||
1333 | return 0; | |
1334 | } | |
1335 | ||
781c53bc | 1336 | #define BPF_LDST_LEN 16U |
91bc4822 AS |
1337 | |
1338 | static u64 bpf_skb_store_bytes(u64 r1, u64 r2, u64 r3, u64 r4, u64 flags) | |
608cd71a AS |
1339 | { |
1340 | struct sk_buff *skb = (struct sk_buff *) (long) r1; | |
a166151c | 1341 | int offset = (int) r2; |
608cd71a AS |
1342 | void *from = (void *) (long) r3; |
1343 | unsigned int len = (unsigned int) r4; | |
05c74e5e | 1344 | char buf[BPF_LDST_LEN]; |
608cd71a AS |
1345 | void *ptr; |
1346 | ||
781c53bc DB |
1347 | if (unlikely(flags & ~(BPF_F_RECOMPUTE_CSUM))) |
1348 | return -EINVAL; | |
1349 | ||
608cd71a AS |
1350 | /* bpf verifier guarantees that: |
1351 | * 'from' pointer points to bpf program stack | |
1352 | * 'len' bytes of it were initialized | |
1353 | * 'len' > 0 | |
1354 | * 'skb' is a valid pointer to 'struct sk_buff' | |
1355 | * | |
1356 | * so check for invalid 'offset' and too large 'len' | |
1357 | */ | |
a166151c | 1358 | if (unlikely((u32) offset > 0xffff || len > sizeof(buf))) |
608cd71a AS |
1359 | return -EFAULT; |
1360 | ||
a166151c | 1361 | if (unlikely(skb_cloned(skb) && |
3431205e | 1362 | !skb_clone_writable(skb, offset + len))) |
608cd71a AS |
1363 | return -EFAULT; |
1364 | ||
1365 | ptr = skb_header_pointer(skb, offset, len, buf); | |
1366 | if (unlikely(!ptr)) | |
1367 | return -EFAULT; | |
1368 | ||
781c53bc | 1369 | if (flags & BPF_F_RECOMPUTE_CSUM) |
91bc4822 | 1370 | skb_postpull_rcsum(skb, ptr, len); |
608cd71a AS |
1371 | |
1372 | memcpy(ptr, from, len); | |
1373 | ||
1374 | if (ptr == buf) | |
1375 | /* skb_store_bits cannot return -EFAULT here */ | |
1376 | skb_store_bits(skb, offset, ptr, len); | |
1377 | ||
781c53bc | 1378 | if (flags & BPF_F_RECOMPUTE_CSUM) |
f8ffad69 DB |
1379 | skb_postpush_rcsum(skb, ptr, len); |
1380 | ||
608cd71a AS |
1381 | return 0; |
1382 | } | |
1383 | ||
1384 | const struct bpf_func_proto bpf_skb_store_bytes_proto = { | |
1385 | .func = bpf_skb_store_bytes, | |
1386 | .gpl_only = false, | |
1387 | .ret_type = RET_INTEGER, | |
1388 | .arg1_type = ARG_PTR_TO_CTX, | |
1389 | .arg2_type = ARG_ANYTHING, | |
1390 | .arg3_type = ARG_PTR_TO_STACK, | |
1391 | .arg4_type = ARG_CONST_STACK_SIZE, | |
91bc4822 AS |
1392 | .arg5_type = ARG_ANYTHING, |
1393 | }; | |
1394 | ||
05c74e5e DB |
1395 | static u64 bpf_skb_load_bytes(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5) |
1396 | { | |
1397 | const struct sk_buff *skb = (const struct sk_buff *)(unsigned long) r1; | |
1398 | int offset = (int) r2; | |
1399 | void *to = (void *)(unsigned long) r3; | |
1400 | unsigned int len = (unsigned int) r4; | |
1401 | void *ptr; | |
1402 | ||
1403 | if (unlikely((u32) offset > 0xffff || len > BPF_LDST_LEN)) | |
1404 | return -EFAULT; | |
1405 | ||
1406 | ptr = skb_header_pointer(skb, offset, len, to); | |
1407 | if (unlikely(!ptr)) | |
1408 | return -EFAULT; | |
1409 | if (ptr != to) | |
1410 | memcpy(to, ptr, len); | |
1411 | ||
1412 | return 0; | |
1413 | } | |
1414 | ||
1415 | const struct bpf_func_proto bpf_skb_load_bytes_proto = { | |
1416 | .func = bpf_skb_load_bytes, | |
1417 | .gpl_only = false, | |
1418 | .ret_type = RET_INTEGER, | |
1419 | .arg1_type = ARG_PTR_TO_CTX, | |
1420 | .arg2_type = ARG_ANYTHING, | |
1421 | .arg3_type = ARG_PTR_TO_STACK, | |
1422 | .arg4_type = ARG_CONST_STACK_SIZE, | |
1423 | }; | |
1424 | ||
a166151c | 1425 | static u64 bpf_l3_csum_replace(u64 r1, u64 r2, u64 from, u64 to, u64 flags) |
91bc4822 AS |
1426 | { |
1427 | struct sk_buff *skb = (struct sk_buff *) (long) r1; | |
a166151c | 1428 | int offset = (int) r2; |
91bc4822 AS |
1429 | __sum16 sum, *ptr; |
1430 | ||
781c53bc DB |
1431 | if (unlikely(flags & ~(BPF_F_HDR_FIELD_MASK))) |
1432 | return -EINVAL; | |
a166151c | 1433 | if (unlikely((u32) offset > 0xffff)) |
91bc4822 AS |
1434 | return -EFAULT; |
1435 | ||
a166151c | 1436 | if (unlikely(skb_cloned(skb) && |
3431205e | 1437 | !skb_clone_writable(skb, offset + sizeof(sum)))) |
91bc4822 AS |
1438 | return -EFAULT; |
1439 | ||
1440 | ptr = skb_header_pointer(skb, offset, sizeof(sum), &sum); | |
1441 | if (unlikely(!ptr)) | |
1442 | return -EFAULT; | |
1443 | ||
781c53bc | 1444 | switch (flags & BPF_F_HDR_FIELD_MASK) { |
91bc4822 AS |
1445 | case 2: |
1446 | csum_replace2(ptr, from, to); | |
1447 | break; | |
1448 | case 4: | |
1449 | csum_replace4(ptr, from, to); | |
1450 | break; | |
1451 | default: | |
1452 | return -EINVAL; | |
1453 | } | |
1454 | ||
1455 | if (ptr == &sum) | |
1456 | /* skb_store_bits guaranteed to not return -EFAULT here */ | |
1457 | skb_store_bits(skb, offset, ptr, sizeof(sum)); | |
1458 | ||
1459 | return 0; | |
1460 | } | |
1461 | ||
1462 | const struct bpf_func_proto bpf_l3_csum_replace_proto = { | |
1463 | .func = bpf_l3_csum_replace, | |
1464 | .gpl_only = false, | |
1465 | .ret_type = RET_INTEGER, | |
1466 | .arg1_type = ARG_PTR_TO_CTX, | |
1467 | .arg2_type = ARG_ANYTHING, | |
1468 | .arg3_type = ARG_ANYTHING, | |
1469 | .arg4_type = ARG_ANYTHING, | |
1470 | .arg5_type = ARG_ANYTHING, | |
1471 | }; | |
1472 | ||
a166151c | 1473 | static u64 bpf_l4_csum_replace(u64 r1, u64 r2, u64 from, u64 to, u64 flags) |
91bc4822 AS |
1474 | { |
1475 | struct sk_buff *skb = (struct sk_buff *) (long) r1; | |
781c53bc | 1476 | bool is_pseudo = flags & BPF_F_PSEUDO_HDR; |
a166151c | 1477 | int offset = (int) r2; |
91bc4822 AS |
1478 | __sum16 sum, *ptr; |
1479 | ||
781c53bc DB |
1480 | if (unlikely(flags & ~(BPF_F_PSEUDO_HDR | BPF_F_HDR_FIELD_MASK))) |
1481 | return -EINVAL; | |
a166151c | 1482 | if (unlikely((u32) offset > 0xffff)) |
91bc4822 AS |
1483 | return -EFAULT; |
1484 | ||
a166151c | 1485 | if (unlikely(skb_cloned(skb) && |
3431205e | 1486 | !skb_clone_writable(skb, offset + sizeof(sum)))) |
91bc4822 AS |
1487 | return -EFAULT; |
1488 | ||
1489 | ptr = skb_header_pointer(skb, offset, sizeof(sum), &sum); | |
1490 | if (unlikely(!ptr)) | |
1491 | return -EFAULT; | |
1492 | ||
781c53bc | 1493 | switch (flags & BPF_F_HDR_FIELD_MASK) { |
91bc4822 AS |
1494 | case 2: |
1495 | inet_proto_csum_replace2(ptr, skb, from, to, is_pseudo); | |
1496 | break; | |
1497 | case 4: | |
1498 | inet_proto_csum_replace4(ptr, skb, from, to, is_pseudo); | |
1499 | break; | |
1500 | default: | |
1501 | return -EINVAL; | |
1502 | } | |
1503 | ||
1504 | if (ptr == &sum) | |
1505 | /* skb_store_bits guaranteed to not return -EFAULT here */ | |
1506 | skb_store_bits(skb, offset, ptr, sizeof(sum)); | |
1507 | ||
1508 | return 0; | |
1509 | } | |
1510 | ||
1511 | const struct bpf_func_proto bpf_l4_csum_replace_proto = { | |
1512 | .func = bpf_l4_csum_replace, | |
1513 | .gpl_only = false, | |
1514 | .ret_type = RET_INTEGER, | |
1515 | .arg1_type = ARG_PTR_TO_CTX, | |
1516 | .arg2_type = ARG_ANYTHING, | |
1517 | .arg3_type = ARG_ANYTHING, | |
1518 | .arg4_type = ARG_ANYTHING, | |
1519 | .arg5_type = ARG_ANYTHING, | |
608cd71a AS |
1520 | }; |
1521 | ||
3896d655 AS |
1522 | static u64 bpf_clone_redirect(u64 r1, u64 ifindex, u64 flags, u64 r4, u64 r5) |
1523 | { | |
1524 | struct sk_buff *skb = (struct sk_buff *) (long) r1, *skb2; | |
1525 | struct net_device *dev; | |
1526 | ||
781c53bc DB |
1527 | if (unlikely(flags & ~(BPF_F_INGRESS))) |
1528 | return -EINVAL; | |
1529 | ||
3896d655 AS |
1530 | dev = dev_get_by_index_rcu(dev_net(skb->dev), ifindex); |
1531 | if (unlikely(!dev)) | |
1532 | return -EINVAL; | |
1533 | ||
3896d655 AS |
1534 | skb2 = skb_clone(skb, GFP_ATOMIC); |
1535 | if (unlikely(!skb2)) | |
1536 | return -ENOMEM; | |
1537 | ||
781c53bc | 1538 | if (flags & BPF_F_INGRESS) { |
f8ffad69 DB |
1539 | if (skb_at_tc_ingress(skb2)) |
1540 | skb_postpush_rcsum(skb2, skb_mac_header(skb2), | |
1541 | skb2->mac_len); | |
3896d655 | 1542 | return dev_forward_skb(dev, skb2); |
f8ffad69 | 1543 | } |
3896d655 AS |
1544 | |
1545 | skb2->dev = dev; | |
6bf05773 | 1546 | skb_sender_cpu_clear(skb2); |
3896d655 AS |
1547 | return dev_queue_xmit(skb2); |
1548 | } | |
1549 | ||
1550 | const struct bpf_func_proto bpf_clone_redirect_proto = { | |
1551 | .func = bpf_clone_redirect, | |
1552 | .gpl_only = false, | |
1553 | .ret_type = RET_INTEGER, | |
1554 | .arg1_type = ARG_PTR_TO_CTX, | |
1555 | .arg2_type = ARG_ANYTHING, | |
1556 | .arg3_type = ARG_ANYTHING, | |
1557 | }; | |
1558 | ||
27b29f63 AS |
1559 | struct redirect_info { |
1560 | u32 ifindex; | |
1561 | u32 flags; | |
1562 | }; | |
1563 | ||
1564 | static DEFINE_PER_CPU(struct redirect_info, redirect_info); | |
781c53bc | 1565 | |
27b29f63 AS |
1566 | static u64 bpf_redirect(u64 ifindex, u64 flags, u64 r3, u64 r4, u64 r5) |
1567 | { | |
1568 | struct redirect_info *ri = this_cpu_ptr(&redirect_info); | |
1569 | ||
781c53bc DB |
1570 | if (unlikely(flags & ~(BPF_F_INGRESS))) |
1571 | return TC_ACT_SHOT; | |
1572 | ||
27b29f63 AS |
1573 | ri->ifindex = ifindex; |
1574 | ri->flags = flags; | |
781c53bc | 1575 | |
27b29f63 AS |
1576 | return TC_ACT_REDIRECT; |
1577 | } | |
1578 | ||
1579 | int skb_do_redirect(struct sk_buff *skb) | |
1580 | { | |
1581 | struct redirect_info *ri = this_cpu_ptr(&redirect_info); | |
1582 | struct net_device *dev; | |
1583 | ||
1584 | dev = dev_get_by_index_rcu(dev_net(skb->dev), ri->ifindex); | |
1585 | ri->ifindex = 0; | |
1586 | if (unlikely(!dev)) { | |
1587 | kfree_skb(skb); | |
1588 | return -EINVAL; | |
1589 | } | |
1590 | ||
781c53bc | 1591 | if (ri->flags & BPF_F_INGRESS) { |
f8ffad69 DB |
1592 | if (skb_at_tc_ingress(skb)) |
1593 | skb_postpush_rcsum(skb, skb_mac_header(skb), | |
1594 | skb->mac_len); | |
27b29f63 | 1595 | return dev_forward_skb(dev, skb); |
f8ffad69 | 1596 | } |
27b29f63 AS |
1597 | |
1598 | skb->dev = dev; | |
cfc81b50 | 1599 | skb_sender_cpu_clear(skb); |
27b29f63 AS |
1600 | return dev_queue_xmit(skb); |
1601 | } | |
1602 | ||
1603 | const struct bpf_func_proto bpf_redirect_proto = { | |
1604 | .func = bpf_redirect, | |
1605 | .gpl_only = false, | |
1606 | .ret_type = RET_INTEGER, | |
1607 | .arg1_type = ARG_ANYTHING, | |
1608 | .arg2_type = ARG_ANYTHING, | |
1609 | }; | |
1610 | ||
8d20aabe DB |
1611 | static u64 bpf_get_cgroup_classid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5) |
1612 | { | |
1613 | return task_get_classid((struct sk_buff *) (unsigned long) r1); | |
1614 | } | |
1615 | ||
1616 | static const struct bpf_func_proto bpf_get_cgroup_classid_proto = { | |
1617 | .func = bpf_get_cgroup_classid, | |
1618 | .gpl_only = false, | |
1619 | .ret_type = RET_INTEGER, | |
1620 | .arg1_type = ARG_PTR_TO_CTX, | |
1621 | }; | |
1622 | ||
c46646d0 DB |
1623 | static u64 bpf_get_route_realm(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5) |
1624 | { | |
1625 | #ifdef CONFIG_IP_ROUTE_CLASSID | |
1626 | const struct dst_entry *dst; | |
1627 | ||
1628 | dst = skb_dst((struct sk_buff *) (unsigned long) r1); | |
1629 | if (dst) | |
1630 | return dst->tclassid; | |
1631 | #endif | |
1632 | return 0; | |
1633 | } | |
1634 | ||
1635 | static const struct bpf_func_proto bpf_get_route_realm_proto = { | |
1636 | .func = bpf_get_route_realm, | |
1637 | .gpl_only = false, | |
1638 | .ret_type = RET_INTEGER, | |
1639 | .arg1_type = ARG_PTR_TO_CTX, | |
1640 | }; | |
1641 | ||
4e10df9a AS |
1642 | static u64 bpf_skb_vlan_push(u64 r1, u64 r2, u64 vlan_tci, u64 r4, u64 r5) |
1643 | { | |
1644 | struct sk_buff *skb = (struct sk_buff *) (long) r1; | |
1645 | __be16 vlan_proto = (__force __be16) r2; | |
1646 | ||
1647 | if (unlikely(vlan_proto != htons(ETH_P_8021Q) && | |
1648 | vlan_proto != htons(ETH_P_8021AD))) | |
1649 | vlan_proto = htons(ETH_P_8021Q); | |
1650 | ||
1651 | return skb_vlan_push(skb, vlan_proto, vlan_tci); | |
1652 | } | |
1653 | ||
1654 | const struct bpf_func_proto bpf_skb_vlan_push_proto = { | |
1655 | .func = bpf_skb_vlan_push, | |
1656 | .gpl_only = false, | |
1657 | .ret_type = RET_INTEGER, | |
1658 | .arg1_type = ARG_PTR_TO_CTX, | |
1659 | .arg2_type = ARG_ANYTHING, | |
1660 | .arg3_type = ARG_ANYTHING, | |
1661 | }; | |
4d9c5c53 | 1662 | EXPORT_SYMBOL_GPL(bpf_skb_vlan_push_proto); |
4e10df9a AS |
1663 | |
1664 | static u64 bpf_skb_vlan_pop(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5) | |
1665 | { | |
1666 | struct sk_buff *skb = (struct sk_buff *) (long) r1; | |
1667 | ||
1668 | return skb_vlan_pop(skb); | |
1669 | } | |
1670 | ||
1671 | const struct bpf_func_proto bpf_skb_vlan_pop_proto = { | |
1672 | .func = bpf_skb_vlan_pop, | |
1673 | .gpl_only = false, | |
1674 | .ret_type = RET_INTEGER, | |
1675 | .arg1_type = ARG_PTR_TO_CTX, | |
1676 | }; | |
4d9c5c53 | 1677 | EXPORT_SYMBOL_GPL(bpf_skb_vlan_pop_proto); |
4e10df9a AS |
1678 | |
1679 | bool bpf_helper_changes_skb_data(void *func) | |
1680 | { | |
1681 | if (func == bpf_skb_vlan_push) | |
1682 | return true; | |
1683 | if (func == bpf_skb_vlan_pop) | |
1684 | return true; | |
1685 | return false; | |
1686 | } | |
1687 | ||
c6c33454 DB |
1688 | static unsigned short bpf_tunnel_key_af(u64 flags) |
1689 | { | |
1690 | return flags & BPF_F_TUNINFO_IPV6 ? AF_INET6 : AF_INET; | |
1691 | } | |
1692 | ||
d3aa45ce AS |
1693 | static u64 bpf_skb_get_tunnel_key(u64 r1, u64 r2, u64 size, u64 flags, u64 r5) |
1694 | { | |
1695 | struct sk_buff *skb = (struct sk_buff *) (long) r1; | |
1696 | struct bpf_tunnel_key *to = (struct bpf_tunnel_key *) (long) r2; | |
c6c33454 DB |
1697 | const struct ip_tunnel_info *info = skb_tunnel_info(skb); |
1698 | u8 compat[sizeof(struct bpf_tunnel_key)]; | |
d3aa45ce | 1699 | |
c6c33454 | 1700 | if (unlikely(!info || (flags & ~(BPF_F_TUNINFO_IPV6)))) |
7f9562a1 | 1701 | return -EINVAL; |
c6c33454 DB |
1702 | if (ip_tunnel_info_af(info) != bpf_tunnel_key_af(flags)) |
1703 | return -EPROTO; | |
1704 | if (unlikely(size != sizeof(struct bpf_tunnel_key))) { | |
1705 | switch (size) { | |
1706 | case offsetof(struct bpf_tunnel_key, remote_ipv6[1]): | |
1707 | /* Fixup deprecated structure layouts here, so we have | |
1708 | * a common path later on. | |
1709 | */ | |
1710 | if (ip_tunnel_info_af(info) != AF_INET) | |
1711 | return -EINVAL; | |
1712 | to = (struct bpf_tunnel_key *)compat; | |
1713 | break; | |
1714 | default: | |
1715 | return -EINVAL; | |
1716 | } | |
1717 | } | |
d3aa45ce AS |
1718 | |
1719 | to->tunnel_id = be64_to_cpu(info->key.tun_id); | |
c6c33454 DB |
1720 | to->tunnel_tos = info->key.tos; |
1721 | to->tunnel_ttl = info->key.ttl; | |
1722 | ||
1723 | if (flags & BPF_F_TUNINFO_IPV6) | |
1724 | memcpy(to->remote_ipv6, &info->key.u.ipv6.src, | |
1725 | sizeof(to->remote_ipv6)); | |
1726 | else | |
1727 | to->remote_ipv4 = be32_to_cpu(info->key.u.ipv4.src); | |
1728 | ||
1729 | if (unlikely(size != sizeof(struct bpf_tunnel_key))) | |
1730 | memcpy((void *)(long) r2, to, size); | |
d3aa45ce AS |
1731 | |
1732 | return 0; | |
1733 | } | |
1734 | ||
1735 | const struct bpf_func_proto bpf_skb_get_tunnel_key_proto = { | |
1736 | .func = bpf_skb_get_tunnel_key, | |
1737 | .gpl_only = false, | |
1738 | .ret_type = RET_INTEGER, | |
1739 | .arg1_type = ARG_PTR_TO_CTX, | |
1740 | .arg2_type = ARG_PTR_TO_STACK, | |
1741 | .arg3_type = ARG_CONST_STACK_SIZE, | |
1742 | .arg4_type = ARG_ANYTHING, | |
1743 | }; | |
1744 | ||
1745 | static struct metadata_dst __percpu *md_dst; | |
1746 | ||
1747 | static u64 bpf_skb_set_tunnel_key(u64 r1, u64 r2, u64 size, u64 flags, u64 r5) | |
1748 | { | |
1749 | struct sk_buff *skb = (struct sk_buff *) (long) r1; | |
1750 | struct bpf_tunnel_key *from = (struct bpf_tunnel_key *) (long) r2; | |
1751 | struct metadata_dst *md = this_cpu_ptr(md_dst); | |
c6c33454 | 1752 | u8 compat[sizeof(struct bpf_tunnel_key)]; |
d3aa45ce AS |
1753 | struct ip_tunnel_info *info; |
1754 | ||
c6c33454 | 1755 | if (unlikely(flags & ~(BPF_F_TUNINFO_IPV6))) |
d3aa45ce | 1756 | return -EINVAL; |
c6c33454 DB |
1757 | if (unlikely(size != sizeof(struct bpf_tunnel_key))) { |
1758 | switch (size) { | |
1759 | case offsetof(struct bpf_tunnel_key, remote_ipv6[1]): | |
1760 | /* Fixup deprecated structure layouts here, so we have | |
1761 | * a common path later on. | |
1762 | */ | |
1763 | memcpy(compat, from, size); | |
1764 | memset(compat + size, 0, sizeof(compat) - size); | |
1765 | from = (struct bpf_tunnel_key *)compat; | |
1766 | break; | |
1767 | default: | |
1768 | return -EINVAL; | |
1769 | } | |
1770 | } | |
d3aa45ce AS |
1771 | |
1772 | skb_dst_drop(skb); | |
1773 | dst_hold((struct dst_entry *) md); | |
1774 | skb_dst_set(skb, (struct dst_entry *) md); | |
1775 | ||
1776 | info = &md->u.tun_info; | |
1777 | info->mode = IP_TUNNEL_INFO_TX; | |
c6c33454 | 1778 | |
1dd34b5a | 1779 | info->key.tun_flags = TUNNEL_KEY; |
d3aa45ce | 1780 | info->key.tun_id = cpu_to_be64(from->tunnel_id); |
c6c33454 DB |
1781 | info->key.tos = from->tunnel_tos; |
1782 | info->key.ttl = from->tunnel_ttl; | |
1783 | ||
1784 | if (flags & BPF_F_TUNINFO_IPV6) { | |
1785 | info->mode |= IP_TUNNEL_INFO_IPV6; | |
1786 | memcpy(&info->key.u.ipv6.dst, from->remote_ipv6, | |
1787 | sizeof(from->remote_ipv6)); | |
1788 | } else { | |
1789 | info->key.u.ipv4.dst = cpu_to_be32(from->remote_ipv4); | |
1790 | } | |
d3aa45ce AS |
1791 | |
1792 | return 0; | |
1793 | } | |
1794 | ||
1795 | const struct bpf_func_proto bpf_skb_set_tunnel_key_proto = { | |
1796 | .func = bpf_skb_set_tunnel_key, | |
1797 | .gpl_only = false, | |
1798 | .ret_type = RET_INTEGER, | |
1799 | .arg1_type = ARG_PTR_TO_CTX, | |
1800 | .arg2_type = ARG_PTR_TO_STACK, | |
1801 | .arg3_type = ARG_CONST_STACK_SIZE, | |
1802 | .arg4_type = ARG_ANYTHING, | |
1803 | }; | |
1804 | ||
1805 | static const struct bpf_func_proto *bpf_get_skb_set_tunnel_key_proto(void) | |
1806 | { | |
1807 | if (!md_dst) { | |
1808 | /* race is not possible, since it's called from | |
1809 | * verifier that is holding verifier mutex | |
1810 | */ | |
1811 | md_dst = metadata_dst_alloc_percpu(0, GFP_KERNEL); | |
1812 | if (!md_dst) | |
1813 | return NULL; | |
1814 | } | |
1815 | return &bpf_skb_set_tunnel_key_proto; | |
1816 | } | |
1817 | ||
d4052c4a DB |
1818 | static const struct bpf_func_proto * |
1819 | sk_filter_func_proto(enum bpf_func_id func_id) | |
89aa0758 AS |
1820 | { |
1821 | switch (func_id) { | |
1822 | case BPF_FUNC_map_lookup_elem: | |
1823 | return &bpf_map_lookup_elem_proto; | |
1824 | case BPF_FUNC_map_update_elem: | |
1825 | return &bpf_map_update_elem_proto; | |
1826 | case BPF_FUNC_map_delete_elem: | |
1827 | return &bpf_map_delete_elem_proto; | |
03e69b50 DB |
1828 | case BPF_FUNC_get_prandom_u32: |
1829 | return &bpf_get_prandom_u32_proto; | |
c04167ce DB |
1830 | case BPF_FUNC_get_smp_processor_id: |
1831 | return &bpf_get_smp_processor_id_proto; | |
04fd61ab AS |
1832 | case BPF_FUNC_tail_call: |
1833 | return &bpf_tail_call_proto; | |
17ca8cbf DB |
1834 | case BPF_FUNC_ktime_get_ns: |
1835 | return &bpf_ktime_get_ns_proto; | |
0756ea3e | 1836 | case BPF_FUNC_trace_printk: |
1be7f75d AS |
1837 | if (capable(CAP_SYS_ADMIN)) |
1838 | return bpf_get_trace_printk_proto(); | |
89aa0758 AS |
1839 | default: |
1840 | return NULL; | |
1841 | } | |
1842 | } | |
1843 | ||
608cd71a AS |
1844 | static const struct bpf_func_proto * |
1845 | tc_cls_act_func_proto(enum bpf_func_id func_id) | |
1846 | { | |
1847 | switch (func_id) { | |
1848 | case BPF_FUNC_skb_store_bytes: | |
1849 | return &bpf_skb_store_bytes_proto; | |
05c74e5e DB |
1850 | case BPF_FUNC_skb_load_bytes: |
1851 | return &bpf_skb_load_bytes_proto; | |
91bc4822 AS |
1852 | case BPF_FUNC_l3_csum_replace: |
1853 | return &bpf_l3_csum_replace_proto; | |
1854 | case BPF_FUNC_l4_csum_replace: | |
1855 | return &bpf_l4_csum_replace_proto; | |
3896d655 AS |
1856 | case BPF_FUNC_clone_redirect: |
1857 | return &bpf_clone_redirect_proto; | |
8d20aabe DB |
1858 | case BPF_FUNC_get_cgroup_classid: |
1859 | return &bpf_get_cgroup_classid_proto; | |
4e10df9a AS |
1860 | case BPF_FUNC_skb_vlan_push: |
1861 | return &bpf_skb_vlan_push_proto; | |
1862 | case BPF_FUNC_skb_vlan_pop: | |
1863 | return &bpf_skb_vlan_pop_proto; | |
d3aa45ce AS |
1864 | case BPF_FUNC_skb_get_tunnel_key: |
1865 | return &bpf_skb_get_tunnel_key_proto; | |
1866 | case BPF_FUNC_skb_set_tunnel_key: | |
1867 | return bpf_get_skb_set_tunnel_key_proto(); | |
27b29f63 AS |
1868 | case BPF_FUNC_redirect: |
1869 | return &bpf_redirect_proto; | |
c46646d0 DB |
1870 | case BPF_FUNC_get_route_realm: |
1871 | return &bpf_get_route_realm_proto; | |
608cd71a AS |
1872 | default: |
1873 | return sk_filter_func_proto(func_id); | |
1874 | } | |
1875 | } | |
1876 | ||
d691f9e8 | 1877 | static bool __is_valid_access(int off, int size, enum bpf_access_type type) |
89aa0758 | 1878 | { |
9bac3d6d AS |
1879 | /* check bounds */ |
1880 | if (off < 0 || off >= sizeof(struct __sk_buff)) | |
1881 | return false; | |
1882 | ||
1883 | /* disallow misaligned access */ | |
1884 | if (off % size != 0) | |
1885 | return false; | |
1886 | ||
1887 | /* all __sk_buff fields are __u32 */ | |
1888 | if (size != 4) | |
1889 | return false; | |
1890 | ||
1891 | return true; | |
1892 | } | |
1893 | ||
d691f9e8 AS |
1894 | static bool sk_filter_is_valid_access(int off, int size, |
1895 | enum bpf_access_type type) | |
1896 | { | |
045efa82 DB |
1897 | if (off == offsetof(struct __sk_buff, tc_classid)) |
1898 | return false; | |
1899 | ||
d691f9e8 AS |
1900 | if (type == BPF_WRITE) { |
1901 | switch (off) { | |
1902 | case offsetof(struct __sk_buff, cb[0]) ... | |
1903 | offsetof(struct __sk_buff, cb[4]): | |
1904 | break; | |
1905 | default: | |
1906 | return false; | |
1907 | } | |
1908 | } | |
1909 | ||
1910 | return __is_valid_access(off, size, type); | |
1911 | } | |
1912 | ||
1913 | static bool tc_cls_act_is_valid_access(int off, int size, | |
1914 | enum bpf_access_type type) | |
1915 | { | |
045efa82 DB |
1916 | if (off == offsetof(struct __sk_buff, tc_classid)) |
1917 | return type == BPF_WRITE ? true : false; | |
1918 | ||
d691f9e8 AS |
1919 | if (type == BPF_WRITE) { |
1920 | switch (off) { | |
1921 | case offsetof(struct __sk_buff, mark): | |
1922 | case offsetof(struct __sk_buff, tc_index): | |
754f1e6a | 1923 | case offsetof(struct __sk_buff, priority): |
d691f9e8 AS |
1924 | case offsetof(struct __sk_buff, cb[0]) ... |
1925 | offsetof(struct __sk_buff, cb[4]): | |
1926 | break; | |
1927 | default: | |
1928 | return false; | |
1929 | } | |
1930 | } | |
1931 | return __is_valid_access(off, size, type); | |
1932 | } | |
1933 | ||
1934 | static u32 bpf_net_convert_ctx_access(enum bpf_access_type type, int dst_reg, | |
1935 | int src_reg, int ctx_off, | |
ff936a04 AS |
1936 | struct bpf_insn *insn_buf, |
1937 | struct bpf_prog *prog) | |
9bac3d6d AS |
1938 | { |
1939 | struct bpf_insn *insn = insn_buf; | |
1940 | ||
1941 | switch (ctx_off) { | |
1942 | case offsetof(struct __sk_buff, len): | |
1943 | BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, len) != 4); | |
1944 | ||
1945 | *insn++ = BPF_LDX_MEM(BPF_W, dst_reg, src_reg, | |
1946 | offsetof(struct sk_buff, len)); | |
1947 | break; | |
1948 | ||
0b8c707d DB |
1949 | case offsetof(struct __sk_buff, protocol): |
1950 | BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, protocol) != 2); | |
1951 | ||
1952 | *insn++ = BPF_LDX_MEM(BPF_H, dst_reg, src_reg, | |
1953 | offsetof(struct sk_buff, protocol)); | |
1954 | break; | |
1955 | ||
27cd5452 MS |
1956 | case offsetof(struct __sk_buff, vlan_proto): |
1957 | BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, vlan_proto) != 2); | |
1958 | ||
1959 | *insn++ = BPF_LDX_MEM(BPF_H, dst_reg, src_reg, | |
1960 | offsetof(struct sk_buff, vlan_proto)); | |
1961 | break; | |
1962 | ||
bcad5718 DB |
1963 | case offsetof(struct __sk_buff, priority): |
1964 | BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, priority) != 4); | |
1965 | ||
754f1e6a DB |
1966 | if (type == BPF_WRITE) |
1967 | *insn++ = BPF_STX_MEM(BPF_W, dst_reg, src_reg, | |
1968 | offsetof(struct sk_buff, priority)); | |
1969 | else | |
1970 | *insn++ = BPF_LDX_MEM(BPF_W, dst_reg, src_reg, | |
1971 | offsetof(struct sk_buff, priority)); | |
bcad5718 DB |
1972 | break; |
1973 | ||
37e82c2f AS |
1974 | case offsetof(struct __sk_buff, ingress_ifindex): |
1975 | BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, skb_iif) != 4); | |
1976 | ||
1977 | *insn++ = BPF_LDX_MEM(BPF_W, dst_reg, src_reg, | |
1978 | offsetof(struct sk_buff, skb_iif)); | |
1979 | break; | |
1980 | ||
1981 | case offsetof(struct __sk_buff, ifindex): | |
1982 | BUILD_BUG_ON(FIELD_SIZEOF(struct net_device, ifindex) != 4); | |
1983 | ||
1984 | *insn++ = BPF_LDX_MEM(bytes_to_bpf_size(FIELD_SIZEOF(struct sk_buff, dev)), | |
1985 | dst_reg, src_reg, | |
1986 | offsetof(struct sk_buff, dev)); | |
1987 | *insn++ = BPF_JMP_IMM(BPF_JEQ, dst_reg, 0, 1); | |
1988 | *insn++ = BPF_LDX_MEM(BPF_W, dst_reg, dst_reg, | |
1989 | offsetof(struct net_device, ifindex)); | |
1990 | break; | |
1991 | ||
ba7591d8 DB |
1992 | case offsetof(struct __sk_buff, hash): |
1993 | BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, hash) != 4); | |
1994 | ||
1995 | *insn++ = BPF_LDX_MEM(BPF_W, dst_reg, src_reg, | |
1996 | offsetof(struct sk_buff, hash)); | |
1997 | break; | |
1998 | ||
9bac3d6d | 1999 | case offsetof(struct __sk_buff, mark): |
d691f9e8 AS |
2000 | BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, mark) != 4); |
2001 | ||
2002 | if (type == BPF_WRITE) | |
2003 | *insn++ = BPF_STX_MEM(BPF_W, dst_reg, src_reg, | |
2004 | offsetof(struct sk_buff, mark)); | |
2005 | else | |
2006 | *insn++ = BPF_LDX_MEM(BPF_W, dst_reg, src_reg, | |
2007 | offsetof(struct sk_buff, mark)); | |
2008 | break; | |
9bac3d6d AS |
2009 | |
2010 | case offsetof(struct __sk_buff, pkt_type): | |
2011 | return convert_skb_access(SKF_AD_PKTTYPE, dst_reg, src_reg, insn); | |
2012 | ||
2013 | case offsetof(struct __sk_buff, queue_mapping): | |
2014 | return convert_skb_access(SKF_AD_QUEUE, dst_reg, src_reg, insn); | |
c2497395 | 2015 | |
c2497395 AS |
2016 | case offsetof(struct __sk_buff, vlan_present): |
2017 | return convert_skb_access(SKF_AD_VLAN_TAG_PRESENT, | |
2018 | dst_reg, src_reg, insn); | |
2019 | ||
2020 | case offsetof(struct __sk_buff, vlan_tci): | |
2021 | return convert_skb_access(SKF_AD_VLAN_TAG, | |
2022 | dst_reg, src_reg, insn); | |
d691f9e8 AS |
2023 | |
2024 | case offsetof(struct __sk_buff, cb[0]) ... | |
2025 | offsetof(struct __sk_buff, cb[4]): | |
2026 | BUILD_BUG_ON(FIELD_SIZEOF(struct qdisc_skb_cb, data) < 20); | |
2027 | ||
ff936a04 | 2028 | prog->cb_access = 1; |
d691f9e8 AS |
2029 | ctx_off -= offsetof(struct __sk_buff, cb[0]); |
2030 | ctx_off += offsetof(struct sk_buff, cb); | |
2031 | ctx_off += offsetof(struct qdisc_skb_cb, data); | |
2032 | if (type == BPF_WRITE) | |
2033 | *insn++ = BPF_STX_MEM(BPF_W, dst_reg, src_reg, ctx_off); | |
2034 | else | |
2035 | *insn++ = BPF_LDX_MEM(BPF_W, dst_reg, src_reg, ctx_off); | |
2036 | break; | |
2037 | ||
045efa82 DB |
2038 | case offsetof(struct __sk_buff, tc_classid): |
2039 | ctx_off -= offsetof(struct __sk_buff, tc_classid); | |
2040 | ctx_off += offsetof(struct sk_buff, cb); | |
2041 | ctx_off += offsetof(struct qdisc_skb_cb, tc_classid); | |
2042 | WARN_ON(type != BPF_WRITE); | |
2043 | *insn++ = BPF_STX_MEM(BPF_H, dst_reg, src_reg, ctx_off); | |
2044 | break; | |
2045 | ||
d691f9e8 AS |
2046 | case offsetof(struct __sk_buff, tc_index): |
2047 | #ifdef CONFIG_NET_SCHED | |
2048 | BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, tc_index) != 2); | |
2049 | ||
2050 | if (type == BPF_WRITE) | |
2051 | *insn++ = BPF_STX_MEM(BPF_H, dst_reg, src_reg, | |
2052 | offsetof(struct sk_buff, tc_index)); | |
2053 | else | |
2054 | *insn++ = BPF_LDX_MEM(BPF_H, dst_reg, src_reg, | |
2055 | offsetof(struct sk_buff, tc_index)); | |
2056 | break; | |
2057 | #else | |
2058 | if (type == BPF_WRITE) | |
2059 | *insn++ = BPF_MOV64_REG(dst_reg, dst_reg); | |
2060 | else | |
2061 | *insn++ = BPF_MOV64_IMM(dst_reg, 0); | |
2062 | break; | |
2063 | #endif | |
9bac3d6d AS |
2064 | } |
2065 | ||
2066 | return insn - insn_buf; | |
89aa0758 AS |
2067 | } |
2068 | ||
d4052c4a DB |
2069 | static const struct bpf_verifier_ops sk_filter_ops = { |
2070 | .get_func_proto = sk_filter_func_proto, | |
2071 | .is_valid_access = sk_filter_is_valid_access, | |
d691f9e8 | 2072 | .convert_ctx_access = bpf_net_convert_ctx_access, |
89aa0758 AS |
2073 | }; |
2074 | ||
608cd71a AS |
2075 | static const struct bpf_verifier_ops tc_cls_act_ops = { |
2076 | .get_func_proto = tc_cls_act_func_proto, | |
d691f9e8 AS |
2077 | .is_valid_access = tc_cls_act_is_valid_access, |
2078 | .convert_ctx_access = bpf_net_convert_ctx_access, | |
608cd71a AS |
2079 | }; |
2080 | ||
d4052c4a DB |
2081 | static struct bpf_prog_type_list sk_filter_type __read_mostly = { |
2082 | .ops = &sk_filter_ops, | |
89aa0758 AS |
2083 | .type = BPF_PROG_TYPE_SOCKET_FILTER, |
2084 | }; | |
2085 | ||
96be4325 | 2086 | static struct bpf_prog_type_list sched_cls_type __read_mostly = { |
608cd71a | 2087 | .ops = &tc_cls_act_ops, |
96be4325 DB |
2088 | .type = BPF_PROG_TYPE_SCHED_CLS, |
2089 | }; | |
2090 | ||
94caee8c | 2091 | static struct bpf_prog_type_list sched_act_type __read_mostly = { |
608cd71a | 2092 | .ops = &tc_cls_act_ops, |
94caee8c DB |
2093 | .type = BPF_PROG_TYPE_SCHED_ACT, |
2094 | }; | |
2095 | ||
d4052c4a | 2096 | static int __init register_sk_filter_ops(void) |
89aa0758 | 2097 | { |
d4052c4a | 2098 | bpf_register_prog_type(&sk_filter_type); |
96be4325 | 2099 | bpf_register_prog_type(&sched_cls_type); |
94caee8c | 2100 | bpf_register_prog_type(&sched_act_type); |
96be4325 | 2101 | |
89aa0758 AS |
2102 | return 0; |
2103 | } | |
d4052c4a DB |
2104 | late_initcall(register_sk_filter_ops); |
2105 | ||
55b33325 PE |
2106 | int sk_detach_filter(struct sock *sk) |
2107 | { | |
2108 | int ret = -ENOENT; | |
2109 | struct sk_filter *filter; | |
2110 | ||
d59577b6 VB |
2111 | if (sock_flag(sk, SOCK_FILTER_LOCKED)) |
2112 | return -EPERM; | |
2113 | ||
f91ff5b9 ED |
2114 | filter = rcu_dereference_protected(sk->sk_filter, |
2115 | sock_owned_by_user(sk)); | |
55b33325 | 2116 | if (filter) { |
a9b3cd7f | 2117 | RCU_INIT_POINTER(sk->sk_filter, NULL); |
46bcf14f | 2118 | sk_filter_uncharge(sk, filter); |
55b33325 PE |
2119 | ret = 0; |
2120 | } | |
a3ea269b | 2121 | |
55b33325 PE |
2122 | return ret; |
2123 | } | |
5ff3f073 | 2124 | EXPORT_SYMBOL_GPL(sk_detach_filter); |
a8fc9277 | 2125 | |
a3ea269b DB |
2126 | int sk_get_filter(struct sock *sk, struct sock_filter __user *ubuf, |
2127 | unsigned int len) | |
a8fc9277 | 2128 | { |
a3ea269b | 2129 | struct sock_fprog_kern *fprog; |
a8fc9277 | 2130 | struct sk_filter *filter; |
a3ea269b | 2131 | int ret = 0; |
a8fc9277 PE |
2132 | |
2133 | lock_sock(sk); | |
2134 | filter = rcu_dereference_protected(sk->sk_filter, | |
a3ea269b | 2135 | sock_owned_by_user(sk)); |
a8fc9277 PE |
2136 | if (!filter) |
2137 | goto out; | |
a3ea269b DB |
2138 | |
2139 | /* We're copying the filter that has been originally attached, | |
93d08b69 DB |
2140 | * so no conversion/decode needed anymore. eBPF programs that |
2141 | * have no original program cannot be dumped through this. | |
a3ea269b | 2142 | */ |
93d08b69 | 2143 | ret = -EACCES; |
7ae457c1 | 2144 | fprog = filter->prog->orig_prog; |
93d08b69 DB |
2145 | if (!fprog) |
2146 | goto out; | |
a3ea269b DB |
2147 | |
2148 | ret = fprog->len; | |
a8fc9277 | 2149 | if (!len) |
a3ea269b | 2150 | /* User space only enquires number of filter blocks. */ |
a8fc9277 | 2151 | goto out; |
a3ea269b | 2152 | |
a8fc9277 | 2153 | ret = -EINVAL; |
a3ea269b | 2154 | if (len < fprog->len) |
a8fc9277 PE |
2155 | goto out; |
2156 | ||
2157 | ret = -EFAULT; | |
009937e7 | 2158 | if (copy_to_user(ubuf, fprog->filter, bpf_classic_proglen(fprog))) |
a3ea269b | 2159 | goto out; |
a8fc9277 | 2160 | |
a3ea269b DB |
2161 | /* Instead of bytes, the API requests to return the number |
2162 | * of filter blocks. | |
2163 | */ | |
2164 | ret = fprog->len; | |
a8fc9277 PE |
2165 | out: |
2166 | release_sock(sk); | |
2167 | return ret; | |
2168 | } |