Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Linux Socket Filter - Kernel level socket filtering |
| 3 | * |
| 4 | * Author: |
| 5 | * Jay Schulist <jschlst@samba.org> |
| 6 | * |
| 7 | * Based on the design of: |
| 8 | * - The Berkeley Packet Filter |
| 9 | * |
| 10 | * This program is free software; you can redistribute it and/or |
| 11 | * modify it under the terms of the GNU General Public License |
| 12 | * as published by the Free Software Foundation; either version |
| 13 | * 2 of the License, or (at your option) any later version. |
| 14 | * |
| 15 | * Andi Kleen - Fix a few bad bugs and races. |
Kris Katterjohn | 9369986 | 2006-01-04 13:58:36 -0800 | [diff] [blame] | 16 | * Kris Katterjohn - Added many additional checks in sk_chk_filter() |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 17 | */ |
| 18 | |
| 19 | #include <linux/module.h> |
| 20 | #include <linux/types.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 21 | #include <linux/mm.h> |
| 22 | #include <linux/fcntl.h> |
| 23 | #include <linux/socket.h> |
| 24 | #include <linux/in.h> |
| 25 | #include <linux/inet.h> |
| 26 | #include <linux/netdevice.h> |
| 27 | #include <linux/if_packet.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 28 | #include <linux/gfp.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 29 | #include <net/ip.h> |
| 30 | #include <net/protocol.h> |
Patrick McHardy | 4738c1d | 2008-04-10 02:02:28 -0700 | [diff] [blame] | 31 | #include <net/netlink.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 32 | #include <linux/skbuff.h> |
| 33 | #include <net/sock.h> |
| 34 | #include <linux/errno.h> |
| 35 | #include <linux/timer.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 36 | #include <asm/uaccess.h> |
Dmitry Mishin | 40daafc | 2006-04-18 14:50:10 -0700 | [diff] [blame] | 37 | #include <asm/unaligned.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 38 | #include <linux/filter.h> |
Eric Dumazet | c26aed4 | 2010-11-18 22:04:46 +0000 | [diff] [blame] | 39 | #include <linux/reciprocal_div.h> |
David S. Miller | 86e4ca6 | 2011-05-26 15:00:31 -0400 | [diff] [blame] | 40 | #include <linux/ratelimit.h> |
Will Drewry | 46b325c | 2012-04-12 16:47:52 -0500 | [diff] [blame] | 41 | #include <linux/seccomp.h> |
Eric Dumazet | f333503 | 2012-10-27 02:26:17 +0000 | [diff] [blame] | 42 | #include <linux/if_vlan.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 43 | |
Jan Seiffert | f03fb3f | 2012-03-30 05:08:19 +0000 | [diff] [blame] | 44 | /* No hurry in this branch |
| 45 | * |
| 46 | * Exported for the bpf jit load helper. |
| 47 | */ |
| 48 | void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb, int k, unsigned int size) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 49 | { |
| 50 | u8 *ptr = NULL; |
| 51 | |
| 52 | if (k >= SKF_NET_OFF) |
Arnaldo Carvalho de Melo | d56f90a | 2007-04-10 20:50:43 -0700 | [diff] [blame] | 53 | ptr = skb_network_header(skb) + k - SKF_NET_OFF; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 54 | else if (k >= SKF_LL_OFF) |
Arnaldo Carvalho de Melo | 98e399f | 2007-03-19 15:33:04 -0700 | [diff] [blame] | 55 | ptr = skb_mac_header(skb) + k - SKF_LL_OFF; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 56 | |
Eric Dumazet | 4bc65dd | 2010-12-07 22:26:15 +0000 | [diff] [blame] | 57 | if (ptr >= skb->head && ptr + size <= skb_tail_pointer(skb)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 58 | return ptr; |
| 59 | return NULL; |
| 60 | } |
| 61 | |
Eric Dumazet | 62ab081 | 2010-12-06 20:50:09 +0000 | [diff] [blame] | 62 | static inline void *load_pointer(const struct sk_buff *skb, int k, |
YOSHIFUJI Hideaki | 4ec93ed | 2007-02-09 23:24:36 +0900 | [diff] [blame] | 63 | unsigned int size, void *buffer) |
Patrick McHardy | 0b05b2a | 2005-07-05 14:10:21 -0700 | [diff] [blame] | 64 | { |
| 65 | if (k >= 0) |
| 66 | return skb_header_pointer(skb, k, size, buffer); |
Jan Seiffert | f03fb3f | 2012-03-30 05:08:19 +0000 | [diff] [blame] | 67 | return bpf_internal_load_pointer_neg_helper(skb, k, size); |
Patrick McHardy | 0b05b2a | 2005-07-05 14:10:21 -0700 | [diff] [blame] | 68 | } |
| 69 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 70 | /** |
Stephen Hemminger | 43db6d6 | 2008-04-10 01:43:09 -0700 | [diff] [blame] | 71 | * sk_filter - run a packet through a socket filter |
| 72 | * @sk: sock associated with &sk_buff |
| 73 | * @skb: buffer to filter |
Stephen Hemminger | 43db6d6 | 2008-04-10 01:43:09 -0700 | [diff] [blame] | 74 | * |
| 75 | * Run the filter code and then cut skb->data to correct size returned by |
| 76 | * sk_run_filter. If pkt_len is 0 we toss packet. If skb->len is smaller |
| 77 | * than pkt_len we keep whole skb->data. This is the socket level |
| 78 | * wrapper to sk_run_filter. It returns 0 if the packet should |
| 79 | * be accepted or -EPERM if the packet should be tossed. |
| 80 | * |
| 81 | */ |
| 82 | int sk_filter(struct sock *sk, struct sk_buff *skb) |
| 83 | { |
| 84 | int err; |
| 85 | struct sk_filter *filter; |
| 86 | |
Mel Gorman | c93bdd0 | 2012-07-31 16:44:19 -0700 | [diff] [blame] | 87 | /* |
| 88 | * If the skb was allocated from pfmemalloc reserves, only |
| 89 | * allow SOCK_MEMALLOC sockets to use it as this socket is |
| 90 | * helping free memory |
| 91 | */ |
| 92 | if (skb_pfmemalloc(skb) && !sock_flag(sk, SOCK_MEMALLOC)) |
| 93 | return -ENOMEM; |
| 94 | |
Stephen Hemminger | 43db6d6 | 2008-04-10 01:43:09 -0700 | [diff] [blame] | 95 | err = security_sock_rcv_skb(sk, skb); |
| 96 | if (err) |
| 97 | return err; |
| 98 | |
Eric Dumazet | 80f8f10 | 2011-01-18 07:46:52 +0000 | [diff] [blame] | 99 | rcu_read_lock(); |
| 100 | filter = rcu_dereference(sk->sk_filter); |
Stephen Hemminger | 43db6d6 | 2008-04-10 01:43:09 -0700 | [diff] [blame] | 101 | if (filter) { |
Eric Dumazet | 0a14842 | 2011-04-20 09:27:32 +0000 | [diff] [blame] | 102 | unsigned int pkt_len = SK_RUN_FILTER(filter, skb); |
Eric Dumazet | 0d7da9d | 2010-10-25 03:47:05 +0000 | [diff] [blame] | 103 | |
Stephen Hemminger | 43db6d6 | 2008-04-10 01:43:09 -0700 | [diff] [blame] | 104 | err = pkt_len ? pskb_trim(skb, pkt_len) : -EPERM; |
| 105 | } |
Eric Dumazet | 80f8f10 | 2011-01-18 07:46:52 +0000 | [diff] [blame] | 106 | rcu_read_unlock(); |
Stephen Hemminger | 43db6d6 | 2008-04-10 01:43:09 -0700 | [diff] [blame] | 107 | |
| 108 | return err; |
| 109 | } |
| 110 | EXPORT_SYMBOL(sk_filter); |
| 111 | |
| 112 | /** |
Kris Katterjohn | 2966b66 | 2006-01-23 16:26:16 -0800 | [diff] [blame] | 113 | * sk_run_filter - run a filter on a socket |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 114 | * @skb: buffer to run the filter on |
Randy Dunlap | 697d0e3 | 2011-01-08 17:41:42 +0000 | [diff] [blame] | 115 | * @fentry: filter to apply |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 116 | * |
| 117 | * Decode and apply filter instructions to the skb->data. |
Eric Dumazet | 93aaae2 | 2010-11-19 09:49:59 -0800 | [diff] [blame] | 118 | * Return length to keep, 0 for none. @skb is the data we are |
| 119 | * filtering, @filter is the array of filter instructions. |
| 120 | * Because all jumps are guaranteed to be before last instruction, |
| 121 | * and last instruction guaranteed to be a RET, we dont need to check |
| 122 | * flen. (We used to pass to this function the length of filter) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 123 | */ |
Eric Dumazet | 62ab081 | 2010-12-06 20:50:09 +0000 | [diff] [blame] | 124 | unsigned int sk_run_filter(const struct sk_buff *skb, |
| 125 | const struct sock_filter *fentry) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 126 | { |
Patrick McHardy | 0b05b2a | 2005-07-05 14:10:21 -0700 | [diff] [blame] | 127 | void *ptr; |
Kris Katterjohn | 2966b66 | 2006-01-23 16:26:16 -0800 | [diff] [blame] | 128 | u32 A = 0; /* Accumulator */ |
| 129 | u32 X = 0; /* Index Register */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 130 | u32 mem[BPF_MEMWORDS]; /* Scratch Memory Store */ |
Patrick McHardy | 0b05b2a | 2005-07-05 14:10:21 -0700 | [diff] [blame] | 131 | u32 tmp; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 132 | int k; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 133 | |
| 134 | /* |
| 135 | * Process array of filter instructions. |
| 136 | */ |
Eric Dumazet | 93aaae2 | 2010-11-19 09:49:59 -0800 | [diff] [blame] | 137 | for (;; fentry++) { |
| 138 | #if defined(CONFIG_X86_32) |
| 139 | #define K (fentry->k) |
| 140 | #else |
| 141 | const u32 K = fentry->k; |
| 142 | #endif |
YOSHIFUJI Hideaki | 4ec93ed | 2007-02-09 23:24:36 +0900 | [diff] [blame] | 143 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 144 | switch (fentry->code) { |
Hagen Paul Pfeifer | 01f2f3f | 2010-06-19 17:05:36 +0000 | [diff] [blame] | 145 | case BPF_S_ALU_ADD_X: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 146 | A += X; |
| 147 | continue; |
Hagen Paul Pfeifer | 01f2f3f | 2010-06-19 17:05:36 +0000 | [diff] [blame] | 148 | case BPF_S_ALU_ADD_K: |
Eric Dumazet | 93aaae2 | 2010-11-19 09:49:59 -0800 | [diff] [blame] | 149 | A += K; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 150 | continue; |
Hagen Paul Pfeifer | 01f2f3f | 2010-06-19 17:05:36 +0000 | [diff] [blame] | 151 | case BPF_S_ALU_SUB_X: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 152 | A -= X; |
| 153 | continue; |
Hagen Paul Pfeifer | 01f2f3f | 2010-06-19 17:05:36 +0000 | [diff] [blame] | 154 | case BPF_S_ALU_SUB_K: |
Eric Dumazet | 93aaae2 | 2010-11-19 09:49:59 -0800 | [diff] [blame] | 155 | A -= K; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 156 | continue; |
Hagen Paul Pfeifer | 01f2f3f | 2010-06-19 17:05:36 +0000 | [diff] [blame] | 157 | case BPF_S_ALU_MUL_X: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 158 | A *= X; |
| 159 | continue; |
Hagen Paul Pfeifer | 01f2f3f | 2010-06-19 17:05:36 +0000 | [diff] [blame] | 160 | case BPF_S_ALU_MUL_K: |
Eric Dumazet | 93aaae2 | 2010-11-19 09:49:59 -0800 | [diff] [blame] | 161 | A *= K; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 162 | continue; |
Hagen Paul Pfeifer | 01f2f3f | 2010-06-19 17:05:36 +0000 | [diff] [blame] | 163 | case BPF_S_ALU_DIV_X: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 164 | if (X == 0) |
| 165 | return 0; |
| 166 | A /= X; |
| 167 | continue; |
Hagen Paul Pfeifer | 01f2f3f | 2010-06-19 17:05:36 +0000 | [diff] [blame] | 168 | case BPF_S_ALU_DIV_K: |
Eric Dumazet | c26aed4 | 2010-11-18 22:04:46 +0000 | [diff] [blame] | 169 | A = reciprocal_divide(A, K); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 170 | continue; |
Eric Dumazet | b6069a9 | 2012-09-07 22:03:35 +0000 | [diff] [blame] | 171 | case BPF_S_ALU_MOD_X: |
| 172 | if (X == 0) |
| 173 | return 0; |
| 174 | A %= X; |
| 175 | continue; |
| 176 | case BPF_S_ALU_MOD_K: |
| 177 | A %= K; |
| 178 | continue; |
Hagen Paul Pfeifer | 01f2f3f | 2010-06-19 17:05:36 +0000 | [diff] [blame] | 179 | case BPF_S_ALU_AND_X: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 180 | A &= X; |
| 181 | continue; |
Hagen Paul Pfeifer | 01f2f3f | 2010-06-19 17:05:36 +0000 | [diff] [blame] | 182 | case BPF_S_ALU_AND_K: |
Eric Dumazet | 93aaae2 | 2010-11-19 09:49:59 -0800 | [diff] [blame] | 183 | A &= K; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 184 | continue; |
Hagen Paul Pfeifer | 01f2f3f | 2010-06-19 17:05:36 +0000 | [diff] [blame] | 185 | case BPF_S_ALU_OR_X: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 186 | A |= X; |
| 187 | continue; |
Hagen Paul Pfeifer | 01f2f3f | 2010-06-19 17:05:36 +0000 | [diff] [blame] | 188 | case BPF_S_ALU_OR_K: |
Eric Dumazet | 93aaae2 | 2010-11-19 09:49:59 -0800 | [diff] [blame] | 189 | A |= K; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 190 | continue; |
Daniel Borkmann | 9e49e88 | 2012-09-24 02:23:59 +0000 | [diff] [blame] | 191 | case BPF_S_ANC_ALU_XOR_X: |
| 192 | case BPF_S_ALU_XOR_X: |
| 193 | A ^= X; |
| 194 | continue; |
| 195 | case BPF_S_ALU_XOR_K: |
| 196 | A ^= K; |
| 197 | continue; |
Hagen Paul Pfeifer | 01f2f3f | 2010-06-19 17:05:36 +0000 | [diff] [blame] | 198 | case BPF_S_ALU_LSH_X: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 199 | A <<= X; |
| 200 | continue; |
Hagen Paul Pfeifer | 01f2f3f | 2010-06-19 17:05:36 +0000 | [diff] [blame] | 201 | case BPF_S_ALU_LSH_K: |
Eric Dumazet | 93aaae2 | 2010-11-19 09:49:59 -0800 | [diff] [blame] | 202 | A <<= K; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 203 | continue; |
Hagen Paul Pfeifer | 01f2f3f | 2010-06-19 17:05:36 +0000 | [diff] [blame] | 204 | case BPF_S_ALU_RSH_X: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 205 | A >>= X; |
| 206 | continue; |
Hagen Paul Pfeifer | 01f2f3f | 2010-06-19 17:05:36 +0000 | [diff] [blame] | 207 | case BPF_S_ALU_RSH_K: |
Eric Dumazet | 93aaae2 | 2010-11-19 09:49:59 -0800 | [diff] [blame] | 208 | A >>= K; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 209 | continue; |
Hagen Paul Pfeifer | 01f2f3f | 2010-06-19 17:05:36 +0000 | [diff] [blame] | 210 | case BPF_S_ALU_NEG: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 211 | A = -A; |
| 212 | continue; |
Hagen Paul Pfeifer | 01f2f3f | 2010-06-19 17:05:36 +0000 | [diff] [blame] | 213 | case BPF_S_JMP_JA: |
Eric Dumazet | 93aaae2 | 2010-11-19 09:49:59 -0800 | [diff] [blame] | 214 | fentry += K; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 215 | continue; |
Hagen Paul Pfeifer | 01f2f3f | 2010-06-19 17:05:36 +0000 | [diff] [blame] | 216 | case BPF_S_JMP_JGT_K: |
Eric Dumazet | 93aaae2 | 2010-11-19 09:49:59 -0800 | [diff] [blame] | 217 | fentry += (A > K) ? fentry->jt : fentry->jf; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 218 | continue; |
Hagen Paul Pfeifer | 01f2f3f | 2010-06-19 17:05:36 +0000 | [diff] [blame] | 219 | case BPF_S_JMP_JGE_K: |
Eric Dumazet | 93aaae2 | 2010-11-19 09:49:59 -0800 | [diff] [blame] | 220 | fentry += (A >= K) ? fentry->jt : fentry->jf; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 221 | continue; |
Hagen Paul Pfeifer | 01f2f3f | 2010-06-19 17:05:36 +0000 | [diff] [blame] | 222 | case BPF_S_JMP_JEQ_K: |
Eric Dumazet | 93aaae2 | 2010-11-19 09:49:59 -0800 | [diff] [blame] | 223 | fentry += (A == K) ? fentry->jt : fentry->jf; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 224 | continue; |
Hagen Paul Pfeifer | 01f2f3f | 2010-06-19 17:05:36 +0000 | [diff] [blame] | 225 | case BPF_S_JMP_JSET_K: |
Eric Dumazet | 93aaae2 | 2010-11-19 09:49:59 -0800 | [diff] [blame] | 226 | fentry += (A & K) ? fentry->jt : fentry->jf; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 227 | continue; |
Hagen Paul Pfeifer | 01f2f3f | 2010-06-19 17:05:36 +0000 | [diff] [blame] | 228 | case BPF_S_JMP_JGT_X: |
Eric Dumazet | 93aaae2 | 2010-11-19 09:49:59 -0800 | [diff] [blame] | 229 | fentry += (A > X) ? fentry->jt : fentry->jf; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 230 | continue; |
Hagen Paul Pfeifer | 01f2f3f | 2010-06-19 17:05:36 +0000 | [diff] [blame] | 231 | case BPF_S_JMP_JGE_X: |
Eric Dumazet | 93aaae2 | 2010-11-19 09:49:59 -0800 | [diff] [blame] | 232 | fentry += (A >= X) ? fentry->jt : fentry->jf; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 233 | continue; |
Hagen Paul Pfeifer | 01f2f3f | 2010-06-19 17:05:36 +0000 | [diff] [blame] | 234 | case BPF_S_JMP_JEQ_X: |
Eric Dumazet | 93aaae2 | 2010-11-19 09:49:59 -0800 | [diff] [blame] | 235 | fentry += (A == X) ? fentry->jt : fentry->jf; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 236 | continue; |
Hagen Paul Pfeifer | 01f2f3f | 2010-06-19 17:05:36 +0000 | [diff] [blame] | 237 | case BPF_S_JMP_JSET_X: |
Eric Dumazet | 93aaae2 | 2010-11-19 09:49:59 -0800 | [diff] [blame] | 238 | fentry += (A & X) ? fentry->jt : fentry->jf; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 239 | continue; |
Hagen Paul Pfeifer | 01f2f3f | 2010-06-19 17:05:36 +0000 | [diff] [blame] | 240 | case BPF_S_LD_W_ABS: |
Eric Dumazet | 93aaae2 | 2010-11-19 09:49:59 -0800 | [diff] [blame] | 241 | k = K; |
Kris Katterjohn | e35bedf | 2006-01-17 02:25:52 -0800 | [diff] [blame] | 242 | load_w: |
Patrick McHardy | 0b05b2a | 2005-07-05 14:10:21 -0700 | [diff] [blame] | 243 | ptr = load_pointer(skb, k, 4, &tmp); |
| 244 | if (ptr != NULL) { |
Harvey Harrison | d3e2ce3 | 2008-05-02 16:26:16 -0700 | [diff] [blame] | 245 | A = get_unaligned_be32(ptr); |
Patrick McHardy | 0b05b2a | 2005-07-05 14:10:21 -0700 | [diff] [blame] | 246 | continue; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 247 | } |
Eric Dumazet | 12b16da | 2010-12-15 19:45:28 +0000 | [diff] [blame] | 248 | return 0; |
Hagen Paul Pfeifer | 01f2f3f | 2010-06-19 17:05:36 +0000 | [diff] [blame] | 249 | case BPF_S_LD_H_ABS: |
Eric Dumazet | 93aaae2 | 2010-11-19 09:49:59 -0800 | [diff] [blame] | 250 | k = K; |
Kris Katterjohn | e35bedf | 2006-01-17 02:25:52 -0800 | [diff] [blame] | 251 | load_h: |
Patrick McHardy | 0b05b2a | 2005-07-05 14:10:21 -0700 | [diff] [blame] | 252 | ptr = load_pointer(skb, k, 2, &tmp); |
| 253 | if (ptr != NULL) { |
Harvey Harrison | d3e2ce3 | 2008-05-02 16:26:16 -0700 | [diff] [blame] | 254 | A = get_unaligned_be16(ptr); |
Patrick McHardy | 0b05b2a | 2005-07-05 14:10:21 -0700 | [diff] [blame] | 255 | continue; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 256 | } |
Eric Dumazet | 12b16da | 2010-12-15 19:45:28 +0000 | [diff] [blame] | 257 | return 0; |
Hagen Paul Pfeifer | 01f2f3f | 2010-06-19 17:05:36 +0000 | [diff] [blame] | 258 | case BPF_S_LD_B_ABS: |
Eric Dumazet | 93aaae2 | 2010-11-19 09:49:59 -0800 | [diff] [blame] | 259 | k = K; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 260 | load_b: |
Patrick McHardy | 0b05b2a | 2005-07-05 14:10:21 -0700 | [diff] [blame] | 261 | ptr = load_pointer(skb, k, 1, &tmp); |
| 262 | if (ptr != NULL) { |
| 263 | A = *(u8 *)ptr; |
| 264 | continue; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 265 | } |
Eric Dumazet | 12b16da | 2010-12-15 19:45:28 +0000 | [diff] [blame] | 266 | return 0; |
Hagen Paul Pfeifer | 01f2f3f | 2010-06-19 17:05:36 +0000 | [diff] [blame] | 267 | case BPF_S_LD_W_LEN: |
Patrick McHardy | 3154e54 | 2005-07-05 14:10:40 -0700 | [diff] [blame] | 268 | A = skb->len; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 269 | continue; |
Hagen Paul Pfeifer | 01f2f3f | 2010-06-19 17:05:36 +0000 | [diff] [blame] | 270 | case BPF_S_LDX_W_LEN: |
Patrick McHardy | 3154e54 | 2005-07-05 14:10:40 -0700 | [diff] [blame] | 271 | X = skb->len; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 272 | continue; |
Hagen Paul Pfeifer | 01f2f3f | 2010-06-19 17:05:36 +0000 | [diff] [blame] | 273 | case BPF_S_LD_W_IND: |
Eric Dumazet | 93aaae2 | 2010-11-19 09:49:59 -0800 | [diff] [blame] | 274 | k = X + K; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 275 | goto load_w; |
Hagen Paul Pfeifer | 01f2f3f | 2010-06-19 17:05:36 +0000 | [diff] [blame] | 276 | case BPF_S_LD_H_IND: |
Eric Dumazet | 93aaae2 | 2010-11-19 09:49:59 -0800 | [diff] [blame] | 277 | k = X + K; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 278 | goto load_h; |
Hagen Paul Pfeifer | 01f2f3f | 2010-06-19 17:05:36 +0000 | [diff] [blame] | 279 | case BPF_S_LD_B_IND: |
Eric Dumazet | 93aaae2 | 2010-11-19 09:49:59 -0800 | [diff] [blame] | 280 | k = X + K; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 281 | goto load_b; |
Hagen Paul Pfeifer | 01f2f3f | 2010-06-19 17:05:36 +0000 | [diff] [blame] | 282 | case BPF_S_LDX_B_MSH: |
Eric Dumazet | 93aaae2 | 2010-11-19 09:49:59 -0800 | [diff] [blame] | 283 | ptr = load_pointer(skb, K, 1, &tmp); |
Patrick McHardy | 0b05b2a | 2005-07-05 14:10:21 -0700 | [diff] [blame] | 284 | if (ptr != NULL) { |
| 285 | X = (*(u8 *)ptr & 0xf) << 2; |
| 286 | continue; |
| 287 | } |
| 288 | return 0; |
Hagen Paul Pfeifer | 01f2f3f | 2010-06-19 17:05:36 +0000 | [diff] [blame] | 289 | case BPF_S_LD_IMM: |
Eric Dumazet | 93aaae2 | 2010-11-19 09:49:59 -0800 | [diff] [blame] | 290 | A = K; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 291 | continue; |
Hagen Paul Pfeifer | 01f2f3f | 2010-06-19 17:05:36 +0000 | [diff] [blame] | 292 | case BPF_S_LDX_IMM: |
Eric Dumazet | 93aaae2 | 2010-11-19 09:49:59 -0800 | [diff] [blame] | 293 | X = K; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 294 | continue; |
Hagen Paul Pfeifer | 01f2f3f | 2010-06-19 17:05:36 +0000 | [diff] [blame] | 295 | case BPF_S_LD_MEM: |
Eric Dumazet | 2d5311e | 2010-12-01 20:46:24 +0000 | [diff] [blame] | 296 | A = mem[K]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 297 | continue; |
Hagen Paul Pfeifer | 01f2f3f | 2010-06-19 17:05:36 +0000 | [diff] [blame] | 298 | case BPF_S_LDX_MEM: |
Eric Dumazet | 2d5311e | 2010-12-01 20:46:24 +0000 | [diff] [blame] | 299 | X = mem[K]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 300 | continue; |
Hagen Paul Pfeifer | 01f2f3f | 2010-06-19 17:05:36 +0000 | [diff] [blame] | 301 | case BPF_S_MISC_TAX: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 302 | X = A; |
| 303 | continue; |
Hagen Paul Pfeifer | 01f2f3f | 2010-06-19 17:05:36 +0000 | [diff] [blame] | 304 | case BPF_S_MISC_TXA: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 305 | A = X; |
| 306 | continue; |
Hagen Paul Pfeifer | 01f2f3f | 2010-06-19 17:05:36 +0000 | [diff] [blame] | 307 | case BPF_S_RET_K: |
Eric Dumazet | 93aaae2 | 2010-11-19 09:49:59 -0800 | [diff] [blame] | 308 | return K; |
Hagen Paul Pfeifer | 01f2f3f | 2010-06-19 17:05:36 +0000 | [diff] [blame] | 309 | case BPF_S_RET_A: |
Kris Katterjohn | 4bad4dc | 2006-01-06 13:08:20 -0800 | [diff] [blame] | 310 | return A; |
Hagen Paul Pfeifer | 01f2f3f | 2010-06-19 17:05:36 +0000 | [diff] [blame] | 311 | case BPF_S_ST: |
Eric Dumazet | 93aaae2 | 2010-11-19 09:49:59 -0800 | [diff] [blame] | 312 | mem[K] = A; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 313 | continue; |
Hagen Paul Pfeifer | 01f2f3f | 2010-06-19 17:05:36 +0000 | [diff] [blame] | 314 | case BPF_S_STX: |
Eric Dumazet | 93aaae2 | 2010-11-19 09:49:59 -0800 | [diff] [blame] | 315 | mem[K] = X; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 316 | continue; |
Eric Dumazet | 12b16da | 2010-12-15 19:45:28 +0000 | [diff] [blame] | 317 | case BPF_S_ANC_PROTOCOL: |
Al Viro | 252e334 | 2006-11-14 20:48:11 -0800 | [diff] [blame] | 318 | A = ntohs(skb->protocol); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 319 | continue; |
Eric Dumazet | 12b16da | 2010-12-15 19:45:28 +0000 | [diff] [blame] | 320 | case BPF_S_ANC_PKTTYPE: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 321 | A = skb->pkt_type; |
| 322 | continue; |
Eric Dumazet | 12b16da | 2010-12-15 19:45:28 +0000 | [diff] [blame] | 323 | case BPF_S_ANC_IFINDEX: |
Paul LeoNerd Evans | 40eaf96 | 2010-04-22 03:32:22 +0000 | [diff] [blame] | 324 | if (!skb->dev) |
| 325 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 326 | A = skb->dev->ifindex; |
| 327 | continue; |
Eric Dumazet | 12b16da | 2010-12-15 19:45:28 +0000 | [diff] [blame] | 328 | case BPF_S_ANC_MARK: |
jamal | 7e75f93 | 2009-10-19 02:17:56 +0000 | [diff] [blame] | 329 | A = skb->mark; |
| 330 | continue; |
Eric Dumazet | 12b16da | 2010-12-15 19:45:28 +0000 | [diff] [blame] | 331 | case BPF_S_ANC_QUEUE: |
Eric Dumazet | d19742f | 2009-10-20 01:06:22 -0700 | [diff] [blame] | 332 | A = skb->queue_mapping; |
| 333 | continue; |
Eric Dumazet | 12b16da | 2010-12-15 19:45:28 +0000 | [diff] [blame] | 334 | case BPF_S_ANC_HATYPE: |
Paul LeoNerd Evans | 40eaf96 | 2010-04-22 03:32:22 +0000 | [diff] [blame] | 335 | if (!skb->dev) |
| 336 | return 0; |
| 337 | A = skb->dev->type; |
| 338 | continue; |
Eric Dumazet | 12b16da | 2010-12-15 19:45:28 +0000 | [diff] [blame] | 339 | case BPF_S_ANC_RXHASH: |
Eric Dumazet | da2033c | 2010-11-30 21:45:56 +0000 | [diff] [blame] | 340 | A = skb->rxhash; |
| 341 | continue; |
Eric Dumazet | 12b16da | 2010-12-15 19:45:28 +0000 | [diff] [blame] | 342 | case BPF_S_ANC_CPU: |
Eric Dumazet | da2033c | 2010-11-30 21:45:56 +0000 | [diff] [blame] | 343 | A = raw_smp_processor_id(); |
| 344 | continue; |
Eric Dumazet | f333503 | 2012-10-27 02:26:17 +0000 | [diff] [blame] | 345 | case BPF_S_ANC_VLAN_TAG: |
| 346 | A = vlan_tx_tag_get(skb); |
| 347 | continue; |
| 348 | case BPF_S_ANC_VLAN_TAG_PRESENT: |
| 349 | A = !!vlan_tx_tag_present(skb); |
| 350 | continue; |
Eric Dumazet | 12b16da | 2010-12-15 19:45:28 +0000 | [diff] [blame] | 351 | case BPF_S_ANC_NLATTR: { |
Patrick McHardy | 4738c1d | 2008-04-10 02:02:28 -0700 | [diff] [blame] | 352 | struct nlattr *nla; |
| 353 | |
| 354 | if (skb_is_nonlinear(skb)) |
| 355 | return 0; |
| 356 | if (A > skb->len - sizeof(struct nlattr)) |
| 357 | return 0; |
| 358 | |
| 359 | nla = nla_find((struct nlattr *)&skb->data[A], |
| 360 | skb->len - A, X); |
| 361 | if (nla) |
| 362 | A = (void *)nla - (void *)skb->data; |
| 363 | else |
| 364 | A = 0; |
| 365 | continue; |
| 366 | } |
Eric Dumazet | 12b16da | 2010-12-15 19:45:28 +0000 | [diff] [blame] | 367 | case BPF_S_ANC_NLATTR_NEST: { |
Pablo Neira Ayuso | d214c75 | 2008-11-20 00:49:27 -0800 | [diff] [blame] | 368 | struct nlattr *nla; |
| 369 | |
| 370 | if (skb_is_nonlinear(skb)) |
| 371 | return 0; |
| 372 | if (A > skb->len - sizeof(struct nlattr)) |
| 373 | return 0; |
| 374 | |
| 375 | nla = (struct nlattr *)&skb->data[A]; |
| 376 | if (nla->nla_len > A - skb->len) |
| 377 | return 0; |
| 378 | |
| 379 | nla = nla_find_nested(nla, X); |
| 380 | if (nla) |
| 381 | A = (void *)nla - (void *)skb->data; |
| 382 | else |
| 383 | A = 0; |
| 384 | continue; |
| 385 | } |
Will Drewry | 46b325c | 2012-04-12 16:47:52 -0500 | [diff] [blame] | 386 | #ifdef CONFIG_SECCOMP_FILTER |
| 387 | case BPF_S_ANC_SECCOMP_LD_W: |
| 388 | A = seccomp_bpf_load(fentry->k); |
| 389 | continue; |
| 390 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 391 | default: |
Joe Perches | 6c4a5cb | 2011-05-21 07:48:40 +0000 | [diff] [blame] | 392 | WARN_RATELIMIT(1, "Unknown code:%u jt:%u tf:%u k:%u\n", |
| 393 | fentry->code, fentry->jt, |
| 394 | fentry->jf, fentry->k); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 395 | return 0; |
| 396 | } |
| 397 | } |
| 398 | |
| 399 | return 0; |
| 400 | } |
Stephen Hemminger | b715631 | 2008-04-10 01:33:47 -0700 | [diff] [blame] | 401 | EXPORT_SYMBOL(sk_run_filter); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 402 | |
Eric Dumazet | 2d5311e | 2010-12-01 20:46:24 +0000 | [diff] [blame] | 403 | /* |
| 404 | * Security : |
| 405 | * A BPF program is able to use 16 cells of memory to store intermediate |
| 406 | * values (check u32 mem[BPF_MEMWORDS] in sk_run_filter()) |
| 407 | * As we dont want to clear mem[] array for each packet going through |
| 408 | * sk_run_filter(), we check that filter loaded by user never try to read |
| 409 | * a cell if not previously written, and we check all branches to be sure |
Lucas De Marchi | 25985ed | 2011-03-30 22:57:33 -0300 | [diff] [blame] | 410 | * a malicious user doesn't try to abuse us. |
Eric Dumazet | 2d5311e | 2010-12-01 20:46:24 +0000 | [diff] [blame] | 411 | */ |
| 412 | static int check_load_and_stores(struct sock_filter *filter, int flen) |
| 413 | { |
| 414 | u16 *masks, memvalid = 0; /* one bit per cell, 16 cells */ |
| 415 | int pc, ret = 0; |
| 416 | |
| 417 | BUILD_BUG_ON(BPF_MEMWORDS > 16); |
| 418 | masks = kmalloc(flen * sizeof(*masks), GFP_KERNEL); |
| 419 | if (!masks) |
| 420 | return -ENOMEM; |
| 421 | memset(masks, 0xff, flen * sizeof(*masks)); |
| 422 | |
| 423 | for (pc = 0; pc < flen; pc++) { |
| 424 | memvalid &= masks[pc]; |
| 425 | |
| 426 | switch (filter[pc].code) { |
| 427 | case BPF_S_ST: |
| 428 | case BPF_S_STX: |
| 429 | memvalid |= (1 << filter[pc].k); |
| 430 | break; |
| 431 | case BPF_S_LD_MEM: |
| 432 | case BPF_S_LDX_MEM: |
| 433 | if (!(memvalid & (1 << filter[pc].k))) { |
| 434 | ret = -EINVAL; |
| 435 | goto error; |
| 436 | } |
| 437 | break; |
| 438 | case BPF_S_JMP_JA: |
| 439 | /* a jump must set masks on target */ |
| 440 | masks[pc + 1 + filter[pc].k] &= memvalid; |
| 441 | memvalid = ~0; |
| 442 | break; |
| 443 | case BPF_S_JMP_JEQ_K: |
| 444 | case BPF_S_JMP_JEQ_X: |
| 445 | case BPF_S_JMP_JGE_K: |
| 446 | case BPF_S_JMP_JGE_X: |
| 447 | case BPF_S_JMP_JGT_K: |
| 448 | case BPF_S_JMP_JGT_X: |
| 449 | case BPF_S_JMP_JSET_X: |
| 450 | case BPF_S_JMP_JSET_K: |
| 451 | /* a jump must set masks on targets */ |
| 452 | masks[pc + 1 + filter[pc].jt] &= memvalid; |
| 453 | masks[pc + 1 + filter[pc].jf] &= memvalid; |
| 454 | memvalid = ~0; |
| 455 | break; |
| 456 | } |
| 457 | } |
| 458 | error: |
| 459 | kfree(masks); |
| 460 | return ret; |
| 461 | } |
| 462 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 463 | /** |
| 464 | * sk_chk_filter - verify socket filter code |
| 465 | * @filter: filter to verify |
| 466 | * @flen: length of filter |
| 467 | * |
| 468 | * Check the user's filter code. If we let some ugly |
| 469 | * filter code slip through kaboom! The filter must contain |
Kris Katterjohn | 9369986 | 2006-01-04 13:58:36 -0800 | [diff] [blame] | 470 | * no references or jumps that are out of range, no illegal |
| 471 | * instructions, and must end with a RET instruction. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 472 | * |
Kris Katterjohn | 7b11f69 | 2006-01-13 14:33:06 -0800 | [diff] [blame] | 473 | * All jumps are forward as they are not signed. |
| 474 | * |
| 475 | * Returns 0 if the rule set is legal or -EINVAL if not. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 476 | */ |
Dan Carpenter | 4f25af2 | 2011-10-17 21:04:20 +0000 | [diff] [blame] | 477 | int sk_chk_filter(struct sock_filter *filter, unsigned int flen) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 478 | { |
Tetsuo Handa | cba328f | 2010-11-16 15:19:51 +0000 | [diff] [blame] | 479 | /* |
| 480 | * Valid instructions are initialized to non-0. |
| 481 | * Invalid instructions are initialized to 0. |
| 482 | */ |
| 483 | static const u8 codes[] = { |
Eric Dumazet | 8c1592d | 2010-11-18 21:56:38 +0000 | [diff] [blame] | 484 | [BPF_ALU|BPF_ADD|BPF_K] = BPF_S_ALU_ADD_K, |
| 485 | [BPF_ALU|BPF_ADD|BPF_X] = BPF_S_ALU_ADD_X, |
| 486 | [BPF_ALU|BPF_SUB|BPF_K] = BPF_S_ALU_SUB_K, |
| 487 | [BPF_ALU|BPF_SUB|BPF_X] = BPF_S_ALU_SUB_X, |
| 488 | [BPF_ALU|BPF_MUL|BPF_K] = BPF_S_ALU_MUL_K, |
| 489 | [BPF_ALU|BPF_MUL|BPF_X] = BPF_S_ALU_MUL_X, |
| 490 | [BPF_ALU|BPF_DIV|BPF_X] = BPF_S_ALU_DIV_X, |
Eric Dumazet | b6069a9 | 2012-09-07 22:03:35 +0000 | [diff] [blame] | 491 | [BPF_ALU|BPF_MOD|BPF_K] = BPF_S_ALU_MOD_K, |
| 492 | [BPF_ALU|BPF_MOD|BPF_X] = BPF_S_ALU_MOD_X, |
Eric Dumazet | 8c1592d | 2010-11-18 21:56:38 +0000 | [diff] [blame] | 493 | [BPF_ALU|BPF_AND|BPF_K] = BPF_S_ALU_AND_K, |
| 494 | [BPF_ALU|BPF_AND|BPF_X] = BPF_S_ALU_AND_X, |
| 495 | [BPF_ALU|BPF_OR|BPF_K] = BPF_S_ALU_OR_K, |
| 496 | [BPF_ALU|BPF_OR|BPF_X] = BPF_S_ALU_OR_X, |
Daniel Borkmann | 9e49e88 | 2012-09-24 02:23:59 +0000 | [diff] [blame] | 497 | [BPF_ALU|BPF_XOR|BPF_K] = BPF_S_ALU_XOR_K, |
| 498 | [BPF_ALU|BPF_XOR|BPF_X] = BPF_S_ALU_XOR_X, |
Eric Dumazet | 8c1592d | 2010-11-18 21:56:38 +0000 | [diff] [blame] | 499 | [BPF_ALU|BPF_LSH|BPF_K] = BPF_S_ALU_LSH_K, |
| 500 | [BPF_ALU|BPF_LSH|BPF_X] = BPF_S_ALU_LSH_X, |
| 501 | [BPF_ALU|BPF_RSH|BPF_K] = BPF_S_ALU_RSH_K, |
| 502 | [BPF_ALU|BPF_RSH|BPF_X] = BPF_S_ALU_RSH_X, |
| 503 | [BPF_ALU|BPF_NEG] = BPF_S_ALU_NEG, |
| 504 | [BPF_LD|BPF_W|BPF_ABS] = BPF_S_LD_W_ABS, |
| 505 | [BPF_LD|BPF_H|BPF_ABS] = BPF_S_LD_H_ABS, |
| 506 | [BPF_LD|BPF_B|BPF_ABS] = BPF_S_LD_B_ABS, |
| 507 | [BPF_LD|BPF_W|BPF_LEN] = BPF_S_LD_W_LEN, |
| 508 | [BPF_LD|BPF_W|BPF_IND] = BPF_S_LD_W_IND, |
| 509 | [BPF_LD|BPF_H|BPF_IND] = BPF_S_LD_H_IND, |
| 510 | [BPF_LD|BPF_B|BPF_IND] = BPF_S_LD_B_IND, |
| 511 | [BPF_LD|BPF_IMM] = BPF_S_LD_IMM, |
| 512 | [BPF_LDX|BPF_W|BPF_LEN] = BPF_S_LDX_W_LEN, |
| 513 | [BPF_LDX|BPF_B|BPF_MSH] = BPF_S_LDX_B_MSH, |
| 514 | [BPF_LDX|BPF_IMM] = BPF_S_LDX_IMM, |
| 515 | [BPF_MISC|BPF_TAX] = BPF_S_MISC_TAX, |
| 516 | [BPF_MISC|BPF_TXA] = BPF_S_MISC_TXA, |
| 517 | [BPF_RET|BPF_K] = BPF_S_RET_K, |
| 518 | [BPF_RET|BPF_A] = BPF_S_RET_A, |
| 519 | [BPF_ALU|BPF_DIV|BPF_K] = BPF_S_ALU_DIV_K, |
| 520 | [BPF_LD|BPF_MEM] = BPF_S_LD_MEM, |
| 521 | [BPF_LDX|BPF_MEM] = BPF_S_LDX_MEM, |
| 522 | [BPF_ST] = BPF_S_ST, |
| 523 | [BPF_STX] = BPF_S_STX, |
| 524 | [BPF_JMP|BPF_JA] = BPF_S_JMP_JA, |
| 525 | [BPF_JMP|BPF_JEQ|BPF_K] = BPF_S_JMP_JEQ_K, |
| 526 | [BPF_JMP|BPF_JEQ|BPF_X] = BPF_S_JMP_JEQ_X, |
| 527 | [BPF_JMP|BPF_JGE|BPF_K] = BPF_S_JMP_JGE_K, |
| 528 | [BPF_JMP|BPF_JGE|BPF_X] = BPF_S_JMP_JGE_X, |
| 529 | [BPF_JMP|BPF_JGT|BPF_K] = BPF_S_JMP_JGT_K, |
| 530 | [BPF_JMP|BPF_JGT|BPF_X] = BPF_S_JMP_JGT_X, |
| 531 | [BPF_JMP|BPF_JSET|BPF_K] = BPF_S_JMP_JSET_K, |
| 532 | [BPF_JMP|BPF_JSET|BPF_X] = BPF_S_JMP_JSET_X, |
Tetsuo Handa | cba328f | 2010-11-16 15:19:51 +0000 | [diff] [blame] | 533 | }; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 534 | int pc; |
| 535 | |
David S. Miller | 1b93ae64 | 2005-12-27 13:57:59 -0800 | [diff] [blame] | 536 | if (flen == 0 || flen > BPF_MAXINSNS) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 537 | return -EINVAL; |
| 538 | |
| 539 | /* check the filter code now */ |
| 540 | for (pc = 0; pc < flen; pc++) { |
Tetsuo Handa | cba328f | 2010-11-16 15:19:51 +0000 | [diff] [blame] | 541 | struct sock_filter *ftest = &filter[pc]; |
| 542 | u16 code = ftest->code; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 543 | |
Tetsuo Handa | cba328f | 2010-11-16 15:19:51 +0000 | [diff] [blame] | 544 | if (code >= ARRAY_SIZE(codes)) |
| 545 | return -EINVAL; |
| 546 | code = codes[code]; |
Eric Dumazet | 8c1592d | 2010-11-18 21:56:38 +0000 | [diff] [blame] | 547 | if (!code) |
Tetsuo Handa | cba328f | 2010-11-16 15:19:51 +0000 | [diff] [blame] | 548 | return -EINVAL; |
Kris Katterjohn | 9369986 | 2006-01-04 13:58:36 -0800 | [diff] [blame] | 549 | /* Some instructions need special checks */ |
Tetsuo Handa | cba328f | 2010-11-16 15:19:51 +0000 | [diff] [blame] | 550 | switch (code) { |
| 551 | case BPF_S_ALU_DIV_K: |
Kris Katterjohn | 9369986 | 2006-01-04 13:58:36 -0800 | [diff] [blame] | 552 | /* check for division by zero */ |
| 553 | if (ftest->k == 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 554 | return -EINVAL; |
Eric Dumazet | c26aed4 | 2010-11-18 22:04:46 +0000 | [diff] [blame] | 555 | ftest->k = reciprocal_value(ftest->k); |
Kris Katterjohn | 9369986 | 2006-01-04 13:58:36 -0800 | [diff] [blame] | 556 | break; |
Eric Dumazet | b6069a9 | 2012-09-07 22:03:35 +0000 | [diff] [blame] | 557 | case BPF_S_ALU_MOD_K: |
| 558 | /* check for division by zero */ |
| 559 | if (ftest->k == 0) |
| 560 | return -EINVAL; |
| 561 | break; |
Tetsuo Handa | cba328f | 2010-11-16 15:19:51 +0000 | [diff] [blame] | 562 | case BPF_S_LD_MEM: |
| 563 | case BPF_S_LDX_MEM: |
| 564 | case BPF_S_ST: |
| 565 | case BPF_S_STX: |
| 566 | /* check for invalid memory addresses */ |
Kris Katterjohn | 9369986 | 2006-01-04 13:58:36 -0800 | [diff] [blame] | 567 | if (ftest->k >= BPF_MEMWORDS) |
| 568 | return -EINVAL; |
Hagen Paul Pfeifer | 01f2f3f | 2010-06-19 17:05:36 +0000 | [diff] [blame] | 569 | break; |
Tetsuo Handa | cba328f | 2010-11-16 15:19:51 +0000 | [diff] [blame] | 570 | case BPF_S_JMP_JA: |
Kris Katterjohn | 9369986 | 2006-01-04 13:58:36 -0800 | [diff] [blame] | 571 | /* |
| 572 | * Note, the large ftest->k might cause loops. |
| 573 | * Compare this with conditional jumps below, |
| 574 | * where offsets are limited. --ANK (981016) |
| 575 | */ |
Eric Dumazet | 95c9617 | 2012-04-15 05:58:06 +0000 | [diff] [blame] | 576 | if (ftest->k >= (unsigned int)(flen-pc-1)) |
Kris Katterjohn | 9369986 | 2006-01-04 13:58:36 -0800 | [diff] [blame] | 577 | return -EINVAL; |
| 578 | break; |
Hagen Paul Pfeifer | 01f2f3f | 2010-06-19 17:05:36 +0000 | [diff] [blame] | 579 | case BPF_S_JMP_JEQ_K: |
| 580 | case BPF_S_JMP_JEQ_X: |
| 581 | case BPF_S_JMP_JGE_K: |
| 582 | case BPF_S_JMP_JGE_X: |
| 583 | case BPF_S_JMP_JGT_K: |
| 584 | case BPF_S_JMP_JGT_X: |
| 585 | case BPF_S_JMP_JSET_X: |
| 586 | case BPF_S_JMP_JSET_K: |
Tetsuo Handa | cba328f | 2010-11-16 15:19:51 +0000 | [diff] [blame] | 587 | /* for conditionals both must be safe */ |
Hagen Paul Pfeifer | 01f2f3f | 2010-06-19 17:05:36 +0000 | [diff] [blame] | 588 | if (pc + ftest->jt + 1 >= flen || |
| 589 | pc + ftest->jf + 1 >= flen) |
| 590 | return -EINVAL; |
Tetsuo Handa | cba328f | 2010-11-16 15:19:51 +0000 | [diff] [blame] | 591 | break; |
Eric Dumazet | 12b16da | 2010-12-15 19:45:28 +0000 | [diff] [blame] | 592 | case BPF_S_LD_W_ABS: |
| 593 | case BPF_S_LD_H_ABS: |
| 594 | case BPF_S_LD_B_ABS: |
| 595 | #define ANCILLARY(CODE) case SKF_AD_OFF + SKF_AD_##CODE: \ |
| 596 | code = BPF_S_ANC_##CODE; \ |
| 597 | break |
| 598 | switch (ftest->k) { |
| 599 | ANCILLARY(PROTOCOL); |
| 600 | ANCILLARY(PKTTYPE); |
| 601 | ANCILLARY(IFINDEX); |
| 602 | ANCILLARY(NLATTR); |
| 603 | ANCILLARY(NLATTR_NEST); |
| 604 | ANCILLARY(MARK); |
| 605 | ANCILLARY(QUEUE); |
| 606 | ANCILLARY(HATYPE); |
| 607 | ANCILLARY(RXHASH); |
| 608 | ANCILLARY(CPU); |
Jiri Pirko | ffe06c1 | 2012-03-31 11:01:20 +0000 | [diff] [blame] | 609 | ANCILLARY(ALU_XOR_X); |
Eric Dumazet | f333503 | 2012-10-27 02:26:17 +0000 | [diff] [blame] | 610 | ANCILLARY(VLAN_TAG); |
| 611 | ANCILLARY(VLAN_TAG_PRESENT); |
Eric Dumazet | 12b16da | 2010-12-15 19:45:28 +0000 | [diff] [blame] | 612 | } |
Hagen Paul Pfeifer | 01f2f3f | 2010-06-19 17:05:36 +0000 | [diff] [blame] | 613 | } |
Tetsuo Handa | cba328f | 2010-11-16 15:19:51 +0000 | [diff] [blame] | 614 | ftest->code = code; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 615 | } |
| 616 | |
Hagen Paul Pfeifer | 01f2f3f | 2010-06-19 17:05:36 +0000 | [diff] [blame] | 617 | /* last instruction must be a RET code */ |
| 618 | switch (filter[flen - 1].code) { |
| 619 | case BPF_S_RET_K: |
| 620 | case BPF_S_RET_A: |
Eric Dumazet | 2d5311e | 2010-12-01 20:46:24 +0000 | [diff] [blame] | 621 | return check_load_and_stores(filter, flen); |
Tetsuo Handa | cba328f | 2010-11-16 15:19:51 +0000 | [diff] [blame] | 622 | } |
| 623 | return -EINVAL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 624 | } |
Stephen Hemminger | b715631 | 2008-04-10 01:33:47 -0700 | [diff] [blame] | 625 | EXPORT_SYMBOL(sk_chk_filter); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 626 | |
| 627 | /** |
Eric Dumazet | 46bcf14 | 2010-12-06 09:29:43 -0800 | [diff] [blame] | 628 | * sk_filter_release_rcu - Release a socket filter by rcu_head |
Pavel Emelyanov | 47e958e | 2007-10-17 21:22:42 -0700 | [diff] [blame] | 629 | * @rcu: rcu_head that contains the sk_filter to free |
| 630 | */ |
Eric Dumazet | 46bcf14 | 2010-12-06 09:29:43 -0800 | [diff] [blame] | 631 | void sk_filter_release_rcu(struct rcu_head *rcu) |
Pavel Emelyanov | 47e958e | 2007-10-17 21:22:42 -0700 | [diff] [blame] | 632 | { |
| 633 | struct sk_filter *fp = container_of(rcu, struct sk_filter, rcu); |
| 634 | |
Eric Dumazet | 0a14842 | 2011-04-20 09:27:32 +0000 | [diff] [blame] | 635 | bpf_jit_free(fp); |
Eric Dumazet | 46bcf14 | 2010-12-06 09:29:43 -0800 | [diff] [blame] | 636 | kfree(fp); |
Pavel Emelyanov | 47e958e | 2007-10-17 21:22:42 -0700 | [diff] [blame] | 637 | } |
Eric Dumazet | 46bcf14 | 2010-12-06 09:29:43 -0800 | [diff] [blame] | 638 | EXPORT_SYMBOL(sk_filter_release_rcu); |
Pavel Emelyanov | 47e958e | 2007-10-17 21:22:42 -0700 | [diff] [blame] | 639 | |
Jiri Pirko | 302d663 | 2012-03-31 11:01:19 +0000 | [diff] [blame] | 640 | static int __sk_prepare_filter(struct sk_filter *fp) |
| 641 | { |
| 642 | int err; |
| 643 | |
| 644 | fp->bpf_func = sk_run_filter; |
| 645 | |
| 646 | err = sk_chk_filter(fp->insns, fp->len); |
| 647 | if (err) |
| 648 | return err; |
| 649 | |
| 650 | bpf_jit_compile(fp); |
| 651 | return 0; |
| 652 | } |
| 653 | |
| 654 | /** |
| 655 | * sk_unattached_filter_create - create an unattached filter |
| 656 | * @fprog: the filter program |
Randy Dunlap | c6c4b97 | 2012-06-08 14:01:44 +0000 | [diff] [blame] | 657 | * @pfp: the unattached filter that is created |
Jiri Pirko | 302d663 | 2012-03-31 11:01:19 +0000 | [diff] [blame] | 658 | * |
Randy Dunlap | c6c4b97 | 2012-06-08 14:01:44 +0000 | [diff] [blame] | 659 | * Create a filter independent of any socket. We first run some |
Jiri Pirko | 302d663 | 2012-03-31 11:01:19 +0000 | [diff] [blame] | 660 | * sanity checks on it to make sure it does not explode on us later. |
| 661 | * If an error occurs or there is insufficient memory for the filter |
| 662 | * a negative errno code is returned. On success the return is zero. |
| 663 | */ |
| 664 | int sk_unattached_filter_create(struct sk_filter **pfp, |
| 665 | struct sock_fprog *fprog) |
| 666 | { |
| 667 | struct sk_filter *fp; |
| 668 | unsigned int fsize = sizeof(struct sock_filter) * fprog->len; |
| 669 | int err; |
| 670 | |
| 671 | /* Make sure new filter is there and in the right amounts. */ |
| 672 | if (fprog->filter == NULL) |
| 673 | return -EINVAL; |
| 674 | |
| 675 | fp = kmalloc(fsize + sizeof(*fp), GFP_KERNEL); |
| 676 | if (!fp) |
| 677 | return -ENOMEM; |
| 678 | memcpy(fp->insns, fprog->filter, fsize); |
| 679 | |
| 680 | atomic_set(&fp->refcnt, 1); |
| 681 | fp->len = fprog->len; |
| 682 | |
| 683 | err = __sk_prepare_filter(fp); |
| 684 | if (err) |
| 685 | goto free_mem; |
| 686 | |
| 687 | *pfp = fp; |
| 688 | return 0; |
| 689 | free_mem: |
| 690 | kfree(fp); |
| 691 | return err; |
| 692 | } |
| 693 | EXPORT_SYMBOL_GPL(sk_unattached_filter_create); |
| 694 | |
| 695 | void sk_unattached_filter_destroy(struct sk_filter *fp) |
| 696 | { |
| 697 | sk_filter_release(fp); |
| 698 | } |
| 699 | EXPORT_SYMBOL_GPL(sk_unattached_filter_destroy); |
| 700 | |
Pavel Emelyanov | 47e958e | 2007-10-17 21:22:42 -0700 | [diff] [blame] | 701 | /** |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 702 | * sk_attach_filter - attach a socket filter |
| 703 | * @fprog: the filter program |
| 704 | * @sk: the socket to use |
| 705 | * |
| 706 | * Attach the user's filter code. We first run some sanity checks on |
| 707 | * it to make sure it does not explode on us later. If an error |
| 708 | * occurs or there is insufficient memory for the filter a negative |
| 709 | * errno code is returned. On success the return is zero. |
| 710 | */ |
| 711 | int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk) |
| 712 | { |
Pavel Emelyanov | d3904b7 | 2007-10-17 21:22:17 -0700 | [diff] [blame] | 713 | struct sk_filter *fp, *old_fp; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 714 | unsigned int fsize = sizeof(struct sock_filter) * fprog->len; |
| 715 | int err; |
| 716 | |
| 717 | /* Make sure new filter is there and in the right amounts. */ |
Kris Katterjohn | e35bedf | 2006-01-17 02:25:52 -0800 | [diff] [blame] | 718 | if (fprog->filter == NULL) |
| 719 | return -EINVAL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 720 | |
| 721 | fp = sock_kmalloc(sk, fsize+sizeof(*fp), GFP_KERNEL); |
| 722 | if (!fp) |
| 723 | return -ENOMEM; |
| 724 | if (copy_from_user(fp->insns, fprog->filter, fsize)) { |
YOSHIFUJI Hideaki | 4ec93ed | 2007-02-09 23:24:36 +0900 | [diff] [blame] | 725 | sock_kfree_s(sk, fp, fsize+sizeof(*fp)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 726 | return -EFAULT; |
| 727 | } |
| 728 | |
| 729 | atomic_set(&fp->refcnt, 1); |
| 730 | fp->len = fprog->len; |
| 731 | |
Jiri Pirko | 302d663 | 2012-03-31 11:01:19 +0000 | [diff] [blame] | 732 | err = __sk_prepare_filter(fp); |
Pavel Emelyanov | d3904b7 | 2007-10-17 21:22:17 -0700 | [diff] [blame] | 733 | if (err) { |
| 734 | sk_filter_uncharge(sk, fp); |
| 735 | return err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 736 | } |
| 737 | |
Eric Dumazet | f91ff5b | 2010-09-27 06:07:30 +0000 | [diff] [blame] | 738 | old_fp = rcu_dereference_protected(sk->sk_filter, |
| 739 | sock_owned_by_user(sk)); |
Pavel Emelyanov | d3904b7 | 2007-10-17 21:22:17 -0700 | [diff] [blame] | 740 | rcu_assign_pointer(sk->sk_filter, fp); |
Pavel Emelyanov | d3904b7 | 2007-10-17 21:22:17 -0700 | [diff] [blame] | 741 | |
Olof Johansson | 9b013e0 | 2007-10-18 21:48:39 -0700 | [diff] [blame] | 742 | if (old_fp) |
Eric Dumazet | 46bcf14 | 2010-12-06 09:29:43 -0800 | [diff] [blame] | 743 | sk_filter_uncharge(sk, old_fp); |
Pavel Emelyanov | d3904b7 | 2007-10-17 21:22:17 -0700 | [diff] [blame] | 744 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 745 | } |
Michael S. Tsirkin | 5ff3f07 | 2010-02-14 01:01:00 +0000 | [diff] [blame] | 746 | EXPORT_SYMBOL_GPL(sk_attach_filter); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 747 | |
Pavel Emelyanov | 55b3332 | 2007-10-17 21:21:26 -0700 | [diff] [blame] | 748 | int sk_detach_filter(struct sock *sk) |
| 749 | { |
| 750 | int ret = -ENOENT; |
| 751 | struct sk_filter *filter; |
| 752 | |
Eric Dumazet | f91ff5b | 2010-09-27 06:07:30 +0000 | [diff] [blame] | 753 | filter = rcu_dereference_protected(sk->sk_filter, |
| 754 | sock_owned_by_user(sk)); |
Pavel Emelyanov | 55b3332 | 2007-10-17 21:21:26 -0700 | [diff] [blame] | 755 | if (filter) { |
Stephen Hemminger | a9b3cd7 | 2011-08-01 16:19:00 +0000 | [diff] [blame] | 756 | RCU_INIT_POINTER(sk->sk_filter, NULL); |
Eric Dumazet | 46bcf14 | 2010-12-06 09:29:43 -0800 | [diff] [blame] | 757 | sk_filter_uncharge(sk, filter); |
Pavel Emelyanov | 55b3332 | 2007-10-17 21:21:26 -0700 | [diff] [blame] | 758 | ret = 0; |
| 759 | } |
Pavel Emelyanov | 55b3332 | 2007-10-17 21:21:26 -0700 | [diff] [blame] | 760 | return ret; |
| 761 | } |
Michael S. Tsirkin | 5ff3f07 | 2010-02-14 01:01:00 +0000 | [diff] [blame] | 762 | EXPORT_SYMBOL_GPL(sk_detach_filter); |
Pavel Emelyanov | a8fc927 | 2012-11-01 02:01:48 +0000 | [diff] [blame] | 763 | |
| 764 | static void sk_decode_filter(struct sock_filter *filt, struct sock_filter *to) |
| 765 | { |
| 766 | static const u16 decodes[] = { |
| 767 | [BPF_S_ALU_ADD_K] = BPF_ALU|BPF_ADD|BPF_K, |
| 768 | [BPF_S_ALU_ADD_X] = BPF_ALU|BPF_ADD|BPF_X, |
| 769 | [BPF_S_ALU_SUB_K] = BPF_ALU|BPF_SUB|BPF_K, |
| 770 | [BPF_S_ALU_SUB_X] = BPF_ALU|BPF_SUB|BPF_X, |
| 771 | [BPF_S_ALU_MUL_K] = BPF_ALU|BPF_MUL|BPF_K, |
| 772 | [BPF_S_ALU_MUL_X] = BPF_ALU|BPF_MUL|BPF_X, |
| 773 | [BPF_S_ALU_DIV_X] = BPF_ALU|BPF_DIV|BPF_X, |
| 774 | [BPF_S_ALU_MOD_K] = BPF_ALU|BPF_MOD|BPF_K, |
| 775 | [BPF_S_ALU_MOD_X] = BPF_ALU|BPF_MOD|BPF_X, |
| 776 | [BPF_S_ALU_AND_K] = BPF_ALU|BPF_AND|BPF_K, |
| 777 | [BPF_S_ALU_AND_X] = BPF_ALU|BPF_AND|BPF_X, |
| 778 | [BPF_S_ALU_OR_K] = BPF_ALU|BPF_OR|BPF_K, |
| 779 | [BPF_S_ALU_OR_X] = BPF_ALU|BPF_OR|BPF_X, |
| 780 | [BPF_S_ALU_XOR_K] = BPF_ALU|BPF_XOR|BPF_K, |
| 781 | [BPF_S_ALU_XOR_X] = BPF_ALU|BPF_XOR|BPF_X, |
| 782 | [BPF_S_ALU_LSH_K] = BPF_ALU|BPF_LSH|BPF_K, |
| 783 | [BPF_S_ALU_LSH_X] = BPF_ALU|BPF_LSH|BPF_X, |
| 784 | [BPF_S_ALU_RSH_K] = BPF_ALU|BPF_RSH|BPF_K, |
| 785 | [BPF_S_ALU_RSH_X] = BPF_ALU|BPF_RSH|BPF_X, |
| 786 | [BPF_S_ALU_NEG] = BPF_ALU|BPF_NEG, |
| 787 | [BPF_S_LD_W_ABS] = BPF_LD|BPF_W|BPF_ABS, |
| 788 | [BPF_S_LD_H_ABS] = BPF_LD|BPF_H|BPF_ABS, |
| 789 | [BPF_S_LD_B_ABS] = BPF_LD|BPF_B|BPF_ABS, |
| 790 | [BPF_S_ANC_PROTOCOL] = BPF_LD|BPF_B|BPF_ABS, |
| 791 | [BPF_S_ANC_PKTTYPE] = BPF_LD|BPF_B|BPF_ABS, |
| 792 | [BPF_S_ANC_IFINDEX] = BPF_LD|BPF_B|BPF_ABS, |
| 793 | [BPF_S_ANC_NLATTR] = BPF_LD|BPF_B|BPF_ABS, |
| 794 | [BPF_S_ANC_NLATTR_NEST] = BPF_LD|BPF_B|BPF_ABS, |
| 795 | [BPF_S_ANC_MARK] = BPF_LD|BPF_B|BPF_ABS, |
| 796 | [BPF_S_ANC_QUEUE] = BPF_LD|BPF_B|BPF_ABS, |
| 797 | [BPF_S_ANC_HATYPE] = BPF_LD|BPF_B|BPF_ABS, |
| 798 | [BPF_S_ANC_RXHASH] = BPF_LD|BPF_B|BPF_ABS, |
| 799 | [BPF_S_ANC_CPU] = BPF_LD|BPF_B|BPF_ABS, |
| 800 | [BPF_S_ANC_ALU_XOR_X] = BPF_LD|BPF_B|BPF_ABS, |
| 801 | [BPF_S_ANC_SECCOMP_LD_W] = BPF_LD|BPF_B|BPF_ABS, |
| 802 | [BPF_S_ANC_VLAN_TAG] = BPF_LD|BPF_B|BPF_ABS, |
| 803 | [BPF_S_ANC_VLAN_TAG_PRESENT] = BPF_LD|BPF_B|BPF_ABS, |
| 804 | [BPF_S_LD_W_LEN] = BPF_LD|BPF_W|BPF_LEN, |
| 805 | [BPF_S_LD_W_IND] = BPF_LD|BPF_W|BPF_IND, |
| 806 | [BPF_S_LD_H_IND] = BPF_LD|BPF_H|BPF_IND, |
| 807 | [BPF_S_LD_B_IND] = BPF_LD|BPF_B|BPF_IND, |
| 808 | [BPF_S_LD_IMM] = BPF_LD|BPF_IMM, |
| 809 | [BPF_S_LDX_W_LEN] = BPF_LDX|BPF_W|BPF_LEN, |
| 810 | [BPF_S_LDX_B_MSH] = BPF_LDX|BPF_B|BPF_MSH, |
| 811 | [BPF_S_LDX_IMM] = BPF_LDX|BPF_IMM, |
| 812 | [BPF_S_MISC_TAX] = BPF_MISC|BPF_TAX, |
| 813 | [BPF_S_MISC_TXA] = BPF_MISC|BPF_TXA, |
| 814 | [BPF_S_RET_K] = BPF_RET|BPF_K, |
| 815 | [BPF_S_RET_A] = BPF_RET|BPF_A, |
| 816 | [BPF_S_ALU_DIV_K] = BPF_ALU|BPF_DIV|BPF_K, |
| 817 | [BPF_S_LD_MEM] = BPF_LD|BPF_MEM, |
| 818 | [BPF_S_LDX_MEM] = BPF_LDX|BPF_MEM, |
| 819 | [BPF_S_ST] = BPF_ST, |
| 820 | [BPF_S_STX] = BPF_STX, |
| 821 | [BPF_S_JMP_JA] = BPF_JMP|BPF_JA, |
| 822 | [BPF_S_JMP_JEQ_K] = BPF_JMP|BPF_JEQ|BPF_K, |
| 823 | [BPF_S_JMP_JEQ_X] = BPF_JMP|BPF_JEQ|BPF_X, |
| 824 | [BPF_S_JMP_JGE_K] = BPF_JMP|BPF_JGE|BPF_K, |
| 825 | [BPF_S_JMP_JGE_X] = BPF_JMP|BPF_JGE|BPF_X, |
| 826 | [BPF_S_JMP_JGT_K] = BPF_JMP|BPF_JGT|BPF_K, |
| 827 | [BPF_S_JMP_JGT_X] = BPF_JMP|BPF_JGT|BPF_X, |
| 828 | [BPF_S_JMP_JSET_K] = BPF_JMP|BPF_JSET|BPF_K, |
| 829 | [BPF_S_JMP_JSET_X] = BPF_JMP|BPF_JSET|BPF_X, |
| 830 | }; |
| 831 | u16 code; |
| 832 | |
| 833 | code = filt->code; |
| 834 | |
| 835 | to->code = decodes[code]; |
| 836 | to->jt = filt->jt; |
| 837 | to->jf = filt->jf; |
| 838 | |
| 839 | if (code == BPF_S_ALU_DIV_K) { |
| 840 | /* |
| 841 | * When loaded this rule user gave us X, which was |
| 842 | * translated into R = r(X). Now we calculate the |
| 843 | * RR = r(R) and report it back. If next time this |
| 844 | * value is loaded and RRR = r(RR) is calculated |
| 845 | * then the R == RRR will be true. |
| 846 | * |
| 847 | * One exception. X == 1 translates into R == 0 and |
| 848 | * we can't calculate RR out of it with r(). |
| 849 | */ |
| 850 | |
| 851 | if (filt->k == 0) |
| 852 | to->k = 1; |
| 853 | else |
| 854 | to->k = reciprocal_value(filt->k); |
| 855 | |
| 856 | BUG_ON(reciprocal_value(to->k) != filt->k); |
| 857 | } else |
| 858 | to->k = filt->k; |
| 859 | } |
| 860 | |
| 861 | int sk_get_filter(struct sock *sk, struct sock_filter __user *ubuf, unsigned int len) |
| 862 | { |
| 863 | struct sk_filter *filter; |
| 864 | int i, ret; |
| 865 | |
| 866 | lock_sock(sk); |
| 867 | filter = rcu_dereference_protected(sk->sk_filter, |
| 868 | sock_owned_by_user(sk)); |
| 869 | ret = 0; |
| 870 | if (!filter) |
| 871 | goto out; |
| 872 | ret = filter->len; |
| 873 | if (!len) |
| 874 | goto out; |
| 875 | ret = -EINVAL; |
| 876 | if (len < filter->len) |
| 877 | goto out; |
| 878 | |
| 879 | ret = -EFAULT; |
| 880 | for (i = 0; i < filter->len; i++) { |
| 881 | struct sock_filter fb; |
| 882 | |
| 883 | sk_decode_filter(&filter->insns[i], &fb); |
| 884 | if (copy_to_user(&ubuf[i], &fb, sizeof(fb))) |
| 885 | goto out; |
| 886 | } |
| 887 | |
| 888 | ret = filter->len; |
| 889 | out: |
| 890 | release_sock(sk); |
| 891 | return ret; |
| 892 | } |