Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Linux Socket Filter - Kernel level socket filtering |
| 3 | * |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 4 | * Based on the design of the Berkeley Packet Filter. The new |
| 5 | * internal format has been designed by PLUMgrid: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 6 | * |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 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> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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. |
Kris Katterjohn | 9369986 | 2006-01-04 13:58:36 -0800 | [diff] [blame] | 21 | * Kris Katterjohn - Added many additional checks in sk_chk_filter() |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 22 | */ |
| 23 | |
| 24 | #include <linux/module.h> |
| 25 | #include <linux/types.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 33 | #include <linux/gfp.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 34 | #include <net/ip.h> |
| 35 | #include <net/protocol.h> |
Patrick McHardy | 4738c1d | 2008-04-10 02:02:28 -0700 | [diff] [blame] | 36 | #include <net/netlink.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 37 | #include <linux/skbuff.h> |
| 38 | #include <net/sock.h> |
| 39 | #include <linux/errno.h> |
| 40 | #include <linux/timer.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 41 | #include <asm/uaccess.h> |
Dmitry Mishin | 40daafc | 2006-04-18 14:50:10 -0700 | [diff] [blame] | 42 | #include <asm/unaligned.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 43 | #include <linux/filter.h> |
David S. Miller | 86e4ca6 | 2011-05-26 15:00:31 -0400 | [diff] [blame] | 44 | #include <linux/ratelimit.h> |
Will Drewry | 46b325c | 2012-04-12 16:47:52 -0500 | [diff] [blame] | 45 | #include <linux/seccomp.h> |
Eric Dumazet | f333503 | 2012-10-27 02:26:17 +0000 | [diff] [blame] | 46 | #include <linux/if_vlan.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 47 | |
Daniel Borkmann | 3074383 | 2014-05-01 18:34:19 +0200 | [diff] [blame] | 48 | /* Registers */ |
David S. Miller | 1268e25 | 2014-05-13 13:13:33 -0400 | [diff] [blame] | 49 | #define BPF_R0 regs[BPF_REG_0] |
| 50 | #define BPF_R1 regs[BPF_REG_1] |
| 51 | #define BPF_R2 regs[BPF_REG_2] |
| 52 | #define BPF_R3 regs[BPF_REG_3] |
| 53 | #define BPF_R4 regs[BPF_REG_4] |
| 54 | #define BPF_R5 regs[BPF_REG_5] |
| 55 | #define BPF_R6 regs[BPF_REG_6] |
| 56 | #define BPF_R7 regs[BPF_REG_7] |
| 57 | #define BPF_R8 regs[BPF_REG_8] |
| 58 | #define BPF_R9 regs[BPF_REG_9] |
| 59 | #define BPF_R10 regs[BPF_REG_10] |
Daniel Borkmann | 3074383 | 2014-05-01 18:34:19 +0200 | [diff] [blame] | 60 | |
| 61 | /* Named registers */ |
| 62 | #define A regs[insn->a_reg] |
| 63 | #define X regs[insn->x_reg] |
| 64 | #define FP regs[BPF_REG_FP] |
| 65 | #define ARG1 regs[BPF_REG_ARG1] |
| 66 | #define CTX regs[BPF_REG_CTX] |
| 67 | #define K insn->imm |
| 68 | |
Jan Seiffert | f03fb3f | 2012-03-30 05:08:19 +0000 | [diff] [blame] | 69 | /* No hurry in this branch |
| 70 | * |
| 71 | * Exported for the bpf jit load helper. |
| 72 | */ |
| 73 | 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] | 74 | { |
| 75 | u8 *ptr = NULL; |
| 76 | |
| 77 | if (k >= SKF_NET_OFF) |
Arnaldo Carvalho de Melo | d56f90a | 2007-04-10 20:50:43 -0700 | [diff] [blame] | 78 | ptr = skb_network_header(skb) + k - SKF_NET_OFF; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 79 | else if (k >= SKF_LL_OFF) |
Arnaldo Carvalho de Melo | 98e399f | 2007-03-19 15:33:04 -0700 | [diff] [blame] | 80 | ptr = skb_mac_header(skb) + k - SKF_LL_OFF; |
Eric Dumazet | 4bc65dd | 2010-12-07 22:26:15 +0000 | [diff] [blame] | 81 | if (ptr >= skb->head && ptr + size <= skb_tail_pointer(skb)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 82 | return ptr; |
Daniel Borkmann | eb9672f | 2014-05-01 18:34:20 +0200 | [diff] [blame] | 83 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 84 | return NULL; |
| 85 | } |
| 86 | |
Eric Dumazet | 62ab081 | 2010-12-06 20:50:09 +0000 | [diff] [blame] | 87 | static inline void *load_pointer(const struct sk_buff *skb, int k, |
YOSHIFUJI Hideaki | 4ec93ed | 2007-02-09 23:24:36 +0900 | [diff] [blame] | 88 | unsigned int size, void *buffer) |
Patrick McHardy | 0b05b2a | 2005-07-05 14:10:21 -0700 | [diff] [blame] | 89 | { |
| 90 | if (k >= 0) |
| 91 | return skb_header_pointer(skb, k, size, buffer); |
Daniel Borkmann | eb9672f | 2014-05-01 18:34:20 +0200 | [diff] [blame] | 92 | |
Jan Seiffert | f03fb3f | 2012-03-30 05:08:19 +0000 | [diff] [blame] | 93 | return bpf_internal_load_pointer_neg_helper(skb, k, size); |
Patrick McHardy | 0b05b2a | 2005-07-05 14:10:21 -0700 | [diff] [blame] | 94 | } |
| 95 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 96 | /** |
Stephen Hemminger | 43db6d6 | 2008-04-10 01:43:09 -0700 | [diff] [blame] | 97 | * sk_filter - run a packet through a socket filter |
| 98 | * @sk: sock associated with &sk_buff |
| 99 | * @skb: buffer to filter |
Stephen Hemminger | 43db6d6 | 2008-04-10 01:43:09 -0700 | [diff] [blame] | 100 | * |
| 101 | * Run the filter code and then cut skb->data to correct size returned by |
| 102 | * sk_run_filter. If pkt_len is 0 we toss packet. If skb->len is smaller |
| 103 | * than pkt_len we keep whole skb->data. This is the socket level |
| 104 | * wrapper to sk_run_filter. It returns 0 if the packet should |
| 105 | * be accepted or -EPERM if the packet should be tossed. |
| 106 | * |
| 107 | */ |
| 108 | int sk_filter(struct sock *sk, struct sk_buff *skb) |
| 109 | { |
| 110 | int err; |
| 111 | struct sk_filter *filter; |
| 112 | |
Mel Gorman | c93bdd0 | 2012-07-31 16:44:19 -0700 | [diff] [blame] | 113 | /* |
| 114 | * If the skb was allocated from pfmemalloc reserves, only |
| 115 | * allow SOCK_MEMALLOC sockets to use it as this socket is |
| 116 | * helping free memory |
| 117 | */ |
| 118 | if (skb_pfmemalloc(skb) && !sock_flag(sk, SOCK_MEMALLOC)) |
| 119 | return -ENOMEM; |
| 120 | |
Stephen Hemminger | 43db6d6 | 2008-04-10 01:43:09 -0700 | [diff] [blame] | 121 | err = security_sock_rcv_skb(sk, skb); |
| 122 | if (err) |
| 123 | return err; |
| 124 | |
Eric Dumazet | 80f8f10 | 2011-01-18 07:46:52 +0000 | [diff] [blame] | 125 | rcu_read_lock(); |
| 126 | filter = rcu_dereference(sk->sk_filter); |
Stephen Hemminger | 43db6d6 | 2008-04-10 01:43:09 -0700 | [diff] [blame] | 127 | if (filter) { |
Eric Dumazet | 0a14842 | 2011-04-20 09:27:32 +0000 | [diff] [blame] | 128 | unsigned int pkt_len = SK_RUN_FILTER(filter, skb); |
Eric Dumazet | 0d7da9d | 2010-10-25 03:47:05 +0000 | [diff] [blame] | 129 | |
Stephen Hemminger | 43db6d6 | 2008-04-10 01:43:09 -0700 | [diff] [blame] | 130 | err = pkt_len ? pskb_trim(skb, pkt_len) : -EPERM; |
| 131 | } |
Eric Dumazet | 80f8f10 | 2011-01-18 07:46:52 +0000 | [diff] [blame] | 132 | rcu_read_unlock(); |
Stephen Hemminger | 43db6d6 | 2008-04-10 01:43:09 -0700 | [diff] [blame] | 133 | |
| 134 | return err; |
| 135 | } |
| 136 | EXPORT_SYMBOL(sk_filter); |
| 137 | |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 138 | /* Base function for offset calculation. Needs to go into .text section, |
| 139 | * therefore keeping it non-static as well; will also be used by JITs |
| 140 | * anyway later on, so do not let the compiler omit it. |
| 141 | */ |
| 142 | noinline u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5) |
| 143 | { |
| 144 | return 0; |
| 145 | } |
| 146 | |
Stephen Hemminger | 43db6d6 | 2008-04-10 01:43:09 -0700 | [diff] [blame] | 147 | /** |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 148 | * __sk_run_filter - run a filter on a given context |
| 149 | * @ctx: buffer to run the filter on |
Daniel Borkmann | 01d32f6 | 2014-04-01 19:38:01 +0200 | [diff] [blame] | 150 | * @insn: filter to apply |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 151 | * |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 152 | * Decode and apply filter instructions to the skb->data. Return length to |
Daniel Borkmann | 01d32f6 | 2014-04-01 19:38:01 +0200 | [diff] [blame] | 153 | * keep, 0 for none. @ctx is the data we are operating on, @insn is the |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 154 | * array of filter instructions. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 155 | */ |
Alexei Starovoitov | 5fe821a | 2014-05-19 14:56:14 -0700 | [diff] [blame] | 156 | static unsigned int __sk_run_filter(void *ctx, const struct sock_filter_int *insn) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 157 | { |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 158 | u64 stack[MAX_BPF_STACK / sizeof(u64)]; |
| 159 | u64 regs[MAX_BPF_REG], tmp; |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 160 | static const void *jumptable[256] = { |
| 161 | [0 ... 255] = &&default_label, |
| 162 | /* Now overwrite non-defaults ... */ |
Daniel Borkmann | 8556ce7 | 2014-05-23 18:43:57 +0200 | [diff] [blame] | 163 | /* 32 bit ALU operations */ |
| 164 | [BPF_ALU | BPF_ADD | BPF_X] = &&ALU_ADD_X, |
| 165 | [BPF_ALU | BPF_ADD | BPF_K] = &&ALU_ADD_K, |
| 166 | [BPF_ALU | BPF_SUB | BPF_X] = &&ALU_SUB_X, |
| 167 | [BPF_ALU | BPF_SUB | BPF_K] = &&ALU_SUB_K, |
| 168 | [BPF_ALU | BPF_AND | BPF_X] = &&ALU_AND_X, |
| 169 | [BPF_ALU | BPF_AND | BPF_K] = &&ALU_AND_K, |
| 170 | [BPF_ALU | BPF_OR | BPF_X] = &&ALU_OR_X, |
| 171 | [BPF_ALU | BPF_OR | BPF_K] = &&ALU_OR_K, |
| 172 | [BPF_ALU | BPF_LSH | BPF_X] = &&ALU_LSH_X, |
| 173 | [BPF_ALU | BPF_LSH | BPF_K] = &&ALU_LSH_K, |
| 174 | [BPF_ALU | BPF_RSH | BPF_X] = &&ALU_RSH_X, |
| 175 | [BPF_ALU | BPF_RSH | BPF_K] = &&ALU_RSH_K, |
| 176 | [BPF_ALU | BPF_XOR | BPF_X] = &&ALU_XOR_X, |
| 177 | [BPF_ALU | BPF_XOR | BPF_K] = &&ALU_XOR_K, |
| 178 | [BPF_ALU | BPF_MUL | BPF_X] = &&ALU_MUL_X, |
| 179 | [BPF_ALU | BPF_MUL | BPF_K] = &&ALU_MUL_K, |
| 180 | [BPF_ALU | BPF_MOV | BPF_X] = &&ALU_MOV_X, |
| 181 | [BPF_ALU | BPF_MOV | BPF_K] = &&ALU_MOV_K, |
| 182 | [BPF_ALU | BPF_DIV | BPF_X] = &&ALU_DIV_X, |
| 183 | [BPF_ALU | BPF_DIV | BPF_K] = &&ALU_DIV_K, |
| 184 | [BPF_ALU | BPF_MOD | BPF_X] = &&ALU_MOD_X, |
| 185 | [BPF_ALU | BPF_MOD | BPF_K] = &&ALU_MOD_K, |
| 186 | [BPF_ALU | BPF_NEG] = &&ALU_NEG, |
| 187 | [BPF_ALU | BPF_END | BPF_TO_BE] = &&ALU_END_TO_BE, |
| 188 | [BPF_ALU | BPF_END | BPF_TO_LE] = &&ALU_END_TO_LE, |
| 189 | /* 64 bit ALU operations */ |
| 190 | [BPF_ALU64 | BPF_ADD | BPF_X] = &&ALU64_ADD_X, |
| 191 | [BPF_ALU64 | BPF_ADD | BPF_K] = &&ALU64_ADD_K, |
| 192 | [BPF_ALU64 | BPF_SUB | BPF_X] = &&ALU64_SUB_X, |
| 193 | [BPF_ALU64 | BPF_SUB | BPF_K] = &&ALU64_SUB_K, |
| 194 | [BPF_ALU64 | BPF_AND | BPF_X] = &&ALU64_AND_X, |
| 195 | [BPF_ALU64 | BPF_AND | BPF_K] = &&ALU64_AND_K, |
| 196 | [BPF_ALU64 | BPF_OR | BPF_X] = &&ALU64_OR_X, |
| 197 | [BPF_ALU64 | BPF_OR | BPF_K] = &&ALU64_OR_K, |
| 198 | [BPF_ALU64 | BPF_LSH | BPF_X] = &&ALU64_LSH_X, |
| 199 | [BPF_ALU64 | BPF_LSH | BPF_K] = &&ALU64_LSH_K, |
| 200 | [BPF_ALU64 | BPF_RSH | BPF_X] = &&ALU64_RSH_X, |
| 201 | [BPF_ALU64 | BPF_RSH | BPF_K] = &&ALU64_RSH_K, |
| 202 | [BPF_ALU64 | BPF_XOR | BPF_X] = &&ALU64_XOR_X, |
| 203 | [BPF_ALU64 | BPF_XOR | BPF_K] = &&ALU64_XOR_K, |
| 204 | [BPF_ALU64 | BPF_MUL | BPF_X] = &&ALU64_MUL_X, |
| 205 | [BPF_ALU64 | BPF_MUL | BPF_K] = &&ALU64_MUL_K, |
| 206 | [BPF_ALU64 | BPF_MOV | BPF_X] = &&ALU64_MOV_X, |
| 207 | [BPF_ALU64 | BPF_MOV | BPF_K] = &&ALU64_MOV_K, |
| 208 | [BPF_ALU64 | BPF_ARSH | BPF_X] = &&ALU64_ARSH_X, |
| 209 | [BPF_ALU64 | BPF_ARSH | BPF_K] = &&ALU64_ARSH_K, |
| 210 | [BPF_ALU64 | BPF_DIV | BPF_X] = &&ALU64_DIV_X, |
| 211 | [BPF_ALU64 | BPF_DIV | BPF_K] = &&ALU64_DIV_K, |
| 212 | [BPF_ALU64 | BPF_MOD | BPF_X] = &&ALU64_MOD_X, |
| 213 | [BPF_ALU64 | BPF_MOD | BPF_K] = &&ALU64_MOD_K, |
| 214 | [BPF_ALU64 | BPF_NEG] = &&ALU64_NEG, |
| 215 | /* Call instruction */ |
| 216 | [BPF_JMP | BPF_CALL] = &&JMP_CALL, |
| 217 | /* Jumps */ |
| 218 | [BPF_JMP | BPF_JA] = &&JMP_JA, |
| 219 | [BPF_JMP | BPF_JEQ | BPF_X] = &&JMP_JEQ_X, |
| 220 | [BPF_JMP | BPF_JEQ | BPF_K] = &&JMP_JEQ_K, |
| 221 | [BPF_JMP | BPF_JNE | BPF_X] = &&JMP_JNE_X, |
| 222 | [BPF_JMP | BPF_JNE | BPF_K] = &&JMP_JNE_K, |
| 223 | [BPF_JMP | BPF_JGT | BPF_X] = &&JMP_JGT_X, |
| 224 | [BPF_JMP | BPF_JGT | BPF_K] = &&JMP_JGT_K, |
| 225 | [BPF_JMP | BPF_JGE | BPF_X] = &&JMP_JGE_X, |
| 226 | [BPF_JMP | BPF_JGE | BPF_K] = &&JMP_JGE_K, |
| 227 | [BPF_JMP | BPF_JSGT | BPF_X] = &&JMP_JSGT_X, |
| 228 | [BPF_JMP | BPF_JSGT | BPF_K] = &&JMP_JSGT_K, |
| 229 | [BPF_JMP | BPF_JSGE | BPF_X] = &&JMP_JSGE_X, |
| 230 | [BPF_JMP | BPF_JSGE | BPF_K] = &&JMP_JSGE_K, |
| 231 | [BPF_JMP | BPF_JSET | BPF_X] = &&JMP_JSET_X, |
| 232 | [BPF_JMP | BPF_JSET | BPF_K] = &&JMP_JSET_K, |
| 233 | /* Program return */ |
| 234 | [BPF_JMP | BPF_EXIT] = &&JMP_EXIT, |
| 235 | /* Store instructions */ |
| 236 | [BPF_STX | BPF_MEM | BPF_B] = &&STX_MEM_B, |
| 237 | [BPF_STX | BPF_MEM | BPF_H] = &&STX_MEM_H, |
| 238 | [BPF_STX | BPF_MEM | BPF_W] = &&STX_MEM_W, |
| 239 | [BPF_STX | BPF_MEM | BPF_DW] = &&STX_MEM_DW, |
| 240 | [BPF_STX | BPF_XADD | BPF_W] = &&STX_XADD_W, |
| 241 | [BPF_STX | BPF_XADD | BPF_DW] = &&STX_XADD_DW, |
| 242 | [BPF_ST | BPF_MEM | BPF_B] = &&ST_MEM_B, |
| 243 | [BPF_ST | BPF_MEM | BPF_H] = &&ST_MEM_H, |
| 244 | [BPF_ST | BPF_MEM | BPF_W] = &&ST_MEM_W, |
| 245 | [BPF_ST | BPF_MEM | BPF_DW] = &&ST_MEM_DW, |
| 246 | /* Load instructions */ |
| 247 | [BPF_LDX | BPF_MEM | BPF_B] = &&LDX_MEM_B, |
| 248 | [BPF_LDX | BPF_MEM | BPF_H] = &&LDX_MEM_H, |
| 249 | [BPF_LDX | BPF_MEM | BPF_W] = &&LDX_MEM_W, |
| 250 | [BPF_LDX | BPF_MEM | BPF_DW] = &&LDX_MEM_DW, |
| 251 | [BPF_LD | BPF_ABS | BPF_W] = &&LD_ABS_W, |
| 252 | [BPF_LD | BPF_ABS | BPF_H] = &&LD_ABS_H, |
| 253 | [BPF_LD | BPF_ABS | BPF_B] = &&LD_ABS_B, |
| 254 | [BPF_LD | BPF_IND | BPF_W] = &&LD_IND_W, |
| 255 | [BPF_LD | BPF_IND | BPF_H] = &&LD_IND_H, |
| 256 | [BPF_LD | BPF_IND | BPF_B] = &&LD_IND_B, |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 257 | }; |
Daniel Borkmann | 3074383 | 2014-05-01 18:34:19 +0200 | [diff] [blame] | 258 | void *ptr; |
| 259 | int off; |
Patrick McHardy | 4738c1d | 2008-04-10 02:02:28 -0700 | [diff] [blame] | 260 | |
Daniel Borkmann | 3074383 | 2014-05-01 18:34:19 +0200 | [diff] [blame] | 261 | #define CONT ({ insn++; goto select_insn; }) |
| 262 | #define CONT_JMP ({ insn++; goto select_insn; }) |
| 263 | |
| 264 | FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; |
| 265 | ARG1 = (u64) (unsigned long) ctx; |
| 266 | |
| 267 | /* Register for user BPF programs need to be reset first. */ |
| 268 | regs[BPF_REG_A] = 0; |
| 269 | regs[BPF_REG_X] = 0; |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 270 | |
| 271 | select_insn: |
| 272 | goto *jumptable[insn->code]; |
| 273 | |
| 274 | /* ALU */ |
| 275 | #define ALU(OPCODE, OP) \ |
Daniel Borkmann | 5bcfedf | 2014-05-01 18:34:18 +0200 | [diff] [blame] | 276 | ALU64_##OPCODE##_X: \ |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 277 | A = A OP X; \ |
| 278 | CONT; \ |
Daniel Borkmann | 5bcfedf | 2014-05-01 18:34:18 +0200 | [diff] [blame] | 279 | ALU_##OPCODE##_X: \ |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 280 | A = (u32) A OP (u32) X; \ |
| 281 | CONT; \ |
Daniel Borkmann | 5bcfedf | 2014-05-01 18:34:18 +0200 | [diff] [blame] | 282 | ALU64_##OPCODE##_K: \ |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 283 | A = A OP K; \ |
| 284 | CONT; \ |
Daniel Borkmann | 5bcfedf | 2014-05-01 18:34:18 +0200 | [diff] [blame] | 285 | ALU_##OPCODE##_K: \ |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 286 | A = (u32) A OP (u32) K; \ |
| 287 | CONT; |
| 288 | |
Daniel Borkmann | 5bcfedf | 2014-05-01 18:34:18 +0200 | [diff] [blame] | 289 | ALU(ADD, +) |
| 290 | ALU(SUB, -) |
| 291 | ALU(AND, &) |
| 292 | ALU(OR, |) |
| 293 | ALU(LSH, <<) |
| 294 | ALU(RSH, >>) |
| 295 | ALU(XOR, ^) |
| 296 | ALU(MUL, *) |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 297 | #undef ALU |
Daniel Borkmann | 8556ce7 | 2014-05-23 18:43:57 +0200 | [diff] [blame] | 298 | ALU_NEG: |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 299 | A = (u32) -A; |
| 300 | CONT; |
Daniel Borkmann | 8556ce7 | 2014-05-23 18:43:57 +0200 | [diff] [blame] | 301 | ALU64_NEG: |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 302 | A = -A; |
| 303 | CONT; |
Daniel Borkmann | 5bcfedf | 2014-05-01 18:34:18 +0200 | [diff] [blame] | 304 | ALU_MOV_X: |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 305 | A = (u32) X; |
| 306 | CONT; |
Daniel Borkmann | 5bcfedf | 2014-05-01 18:34:18 +0200 | [diff] [blame] | 307 | ALU_MOV_K: |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 308 | A = (u32) K; |
| 309 | CONT; |
Daniel Borkmann | 5bcfedf | 2014-05-01 18:34:18 +0200 | [diff] [blame] | 310 | ALU64_MOV_X: |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 311 | A = X; |
| 312 | CONT; |
Daniel Borkmann | 5bcfedf | 2014-05-01 18:34:18 +0200 | [diff] [blame] | 313 | ALU64_MOV_K: |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 314 | A = K; |
| 315 | CONT; |
Daniel Borkmann | 5bcfedf | 2014-05-01 18:34:18 +0200 | [diff] [blame] | 316 | ALU64_ARSH_X: |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 317 | (*(s64 *) &A) >>= X; |
| 318 | CONT; |
Daniel Borkmann | 5bcfedf | 2014-05-01 18:34:18 +0200 | [diff] [blame] | 319 | ALU64_ARSH_K: |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 320 | (*(s64 *) &A) >>= K; |
| 321 | CONT; |
Daniel Borkmann | 5bcfedf | 2014-05-01 18:34:18 +0200 | [diff] [blame] | 322 | ALU64_MOD_X: |
Daniel Borkmann | 5f9fde5 | 2014-04-05 01:04:03 +0200 | [diff] [blame] | 323 | if (unlikely(X == 0)) |
| 324 | return 0; |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 325 | tmp = A; |
Daniel Borkmann | 5f9fde5 | 2014-04-05 01:04:03 +0200 | [diff] [blame] | 326 | A = do_div(tmp, X); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 327 | CONT; |
Daniel Borkmann | 5bcfedf | 2014-05-01 18:34:18 +0200 | [diff] [blame] | 328 | ALU_MOD_X: |
Daniel Borkmann | 5f9fde5 | 2014-04-05 01:04:03 +0200 | [diff] [blame] | 329 | if (unlikely(X == 0)) |
| 330 | return 0; |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 331 | tmp = (u32) A; |
Daniel Borkmann | 5f9fde5 | 2014-04-05 01:04:03 +0200 | [diff] [blame] | 332 | A = do_div(tmp, (u32) X); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 333 | CONT; |
Daniel Borkmann | 5bcfedf | 2014-05-01 18:34:18 +0200 | [diff] [blame] | 334 | ALU64_MOD_K: |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 335 | tmp = A; |
Daniel Borkmann | 5f9fde5 | 2014-04-05 01:04:03 +0200 | [diff] [blame] | 336 | A = do_div(tmp, K); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 337 | CONT; |
Daniel Borkmann | 5bcfedf | 2014-05-01 18:34:18 +0200 | [diff] [blame] | 338 | ALU_MOD_K: |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 339 | tmp = (u32) A; |
Daniel Borkmann | 5f9fde5 | 2014-04-05 01:04:03 +0200 | [diff] [blame] | 340 | A = do_div(tmp, (u32) K); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 341 | CONT; |
Daniel Borkmann | 5bcfedf | 2014-05-01 18:34:18 +0200 | [diff] [blame] | 342 | ALU64_DIV_X: |
Daniel Borkmann | 5f9fde5 | 2014-04-05 01:04:03 +0200 | [diff] [blame] | 343 | if (unlikely(X == 0)) |
| 344 | return 0; |
| 345 | do_div(A, X); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 346 | CONT; |
Daniel Borkmann | 5bcfedf | 2014-05-01 18:34:18 +0200 | [diff] [blame] | 347 | ALU_DIV_X: |
Daniel Borkmann | 5f9fde5 | 2014-04-05 01:04:03 +0200 | [diff] [blame] | 348 | if (unlikely(X == 0)) |
| 349 | return 0; |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 350 | tmp = (u32) A; |
Daniel Borkmann | 5f9fde5 | 2014-04-05 01:04:03 +0200 | [diff] [blame] | 351 | do_div(tmp, (u32) X); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 352 | A = (u32) tmp; |
| 353 | CONT; |
Daniel Borkmann | 5bcfedf | 2014-05-01 18:34:18 +0200 | [diff] [blame] | 354 | ALU64_DIV_K: |
Daniel Borkmann | 5f9fde5 | 2014-04-05 01:04:03 +0200 | [diff] [blame] | 355 | do_div(A, K); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 356 | CONT; |
Daniel Borkmann | 5bcfedf | 2014-05-01 18:34:18 +0200 | [diff] [blame] | 357 | ALU_DIV_K: |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 358 | tmp = (u32) A; |
Daniel Borkmann | 5f9fde5 | 2014-04-05 01:04:03 +0200 | [diff] [blame] | 359 | do_div(tmp, (u32) K); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 360 | A = (u32) tmp; |
| 361 | CONT; |
Daniel Borkmann | 5bcfedf | 2014-05-01 18:34:18 +0200 | [diff] [blame] | 362 | ALU_END_TO_BE: |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 363 | switch (K) { |
| 364 | case 16: |
| 365 | A = (__force u16) cpu_to_be16(A); |
| 366 | break; |
| 367 | case 32: |
| 368 | A = (__force u32) cpu_to_be32(A); |
| 369 | break; |
| 370 | case 64: |
| 371 | A = (__force u64) cpu_to_be64(A); |
| 372 | break; |
Patrick McHardy | 4738c1d | 2008-04-10 02:02:28 -0700 | [diff] [blame] | 373 | } |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 374 | CONT; |
Daniel Borkmann | 5bcfedf | 2014-05-01 18:34:18 +0200 | [diff] [blame] | 375 | ALU_END_TO_LE: |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 376 | switch (K) { |
| 377 | case 16: |
| 378 | A = (__force u16) cpu_to_le16(A); |
| 379 | break; |
| 380 | case 32: |
| 381 | A = (__force u32) cpu_to_le32(A); |
| 382 | break; |
| 383 | case 64: |
| 384 | A = (__force u64) cpu_to_le64(A); |
| 385 | break; |
Pablo Neira Ayuso | d214c75 | 2008-11-20 00:49:27 -0800 | [diff] [blame] | 386 | } |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 387 | CONT; |
| 388 | |
| 389 | /* CALL */ |
Daniel Borkmann | 8556ce7 | 2014-05-23 18:43:57 +0200 | [diff] [blame] | 390 | JMP_CALL: |
David S. Miller | 1268e25 | 2014-05-13 13:13:33 -0400 | [diff] [blame] | 391 | /* Function call scratches BPF_R1-BPF_R5 registers, |
| 392 | * preserves BPF_R6-BPF_R9, and stores return value |
| 393 | * into BPF_R0. |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 394 | */ |
David S. Miller | 1268e25 | 2014-05-13 13:13:33 -0400 | [diff] [blame] | 395 | BPF_R0 = (__bpf_call_base + insn->imm)(BPF_R1, BPF_R2, BPF_R3, |
| 396 | BPF_R4, BPF_R5); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 397 | CONT; |
| 398 | |
| 399 | /* JMP */ |
Daniel Borkmann | 8556ce7 | 2014-05-23 18:43:57 +0200 | [diff] [blame] | 400 | JMP_JA: |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 401 | insn += insn->off; |
| 402 | CONT; |
Daniel Borkmann | 5bcfedf | 2014-05-01 18:34:18 +0200 | [diff] [blame] | 403 | JMP_JEQ_X: |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 404 | if (A == X) { |
| 405 | insn += insn->off; |
| 406 | CONT_JMP; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 407 | } |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 408 | CONT; |
Daniel Borkmann | 5bcfedf | 2014-05-01 18:34:18 +0200 | [diff] [blame] | 409 | JMP_JEQ_K: |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 410 | if (A == K) { |
| 411 | insn += insn->off; |
| 412 | CONT_JMP; |
| 413 | } |
| 414 | CONT; |
Daniel Borkmann | 5bcfedf | 2014-05-01 18:34:18 +0200 | [diff] [blame] | 415 | JMP_JNE_X: |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 416 | if (A != X) { |
| 417 | insn += insn->off; |
| 418 | CONT_JMP; |
| 419 | } |
| 420 | CONT; |
Daniel Borkmann | 5bcfedf | 2014-05-01 18:34:18 +0200 | [diff] [blame] | 421 | JMP_JNE_K: |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 422 | if (A != K) { |
| 423 | insn += insn->off; |
| 424 | CONT_JMP; |
| 425 | } |
| 426 | CONT; |
Daniel Borkmann | 5bcfedf | 2014-05-01 18:34:18 +0200 | [diff] [blame] | 427 | JMP_JGT_X: |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 428 | if (A > X) { |
| 429 | insn += insn->off; |
| 430 | CONT_JMP; |
| 431 | } |
| 432 | CONT; |
Daniel Borkmann | 5bcfedf | 2014-05-01 18:34:18 +0200 | [diff] [blame] | 433 | JMP_JGT_K: |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 434 | if (A > K) { |
| 435 | insn += insn->off; |
| 436 | CONT_JMP; |
| 437 | } |
| 438 | CONT; |
Daniel Borkmann | 5bcfedf | 2014-05-01 18:34:18 +0200 | [diff] [blame] | 439 | JMP_JGE_X: |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 440 | if (A >= X) { |
| 441 | insn += insn->off; |
| 442 | CONT_JMP; |
| 443 | } |
| 444 | CONT; |
Daniel Borkmann | 5bcfedf | 2014-05-01 18:34:18 +0200 | [diff] [blame] | 445 | JMP_JGE_K: |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 446 | if (A >= K) { |
| 447 | insn += insn->off; |
| 448 | CONT_JMP; |
| 449 | } |
| 450 | CONT; |
Daniel Borkmann | 5bcfedf | 2014-05-01 18:34:18 +0200 | [diff] [blame] | 451 | JMP_JSGT_X: |
| 452 | if (((s64) A) > ((s64) X)) { |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 453 | insn += insn->off; |
| 454 | CONT_JMP; |
| 455 | } |
| 456 | CONT; |
Daniel Borkmann | 5bcfedf | 2014-05-01 18:34:18 +0200 | [diff] [blame] | 457 | JMP_JSGT_K: |
| 458 | if (((s64) A) > ((s64) K)) { |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 459 | insn += insn->off; |
| 460 | CONT_JMP; |
| 461 | } |
| 462 | CONT; |
Daniel Borkmann | 5bcfedf | 2014-05-01 18:34:18 +0200 | [diff] [blame] | 463 | JMP_JSGE_X: |
| 464 | if (((s64) A) >= ((s64) X)) { |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 465 | insn += insn->off; |
| 466 | CONT_JMP; |
| 467 | } |
| 468 | CONT; |
Daniel Borkmann | 5bcfedf | 2014-05-01 18:34:18 +0200 | [diff] [blame] | 469 | JMP_JSGE_K: |
| 470 | if (((s64) A) >= ((s64) K)) { |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 471 | insn += insn->off; |
| 472 | CONT_JMP; |
| 473 | } |
| 474 | CONT; |
Daniel Borkmann | 5bcfedf | 2014-05-01 18:34:18 +0200 | [diff] [blame] | 475 | JMP_JSET_X: |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 476 | if (A & X) { |
| 477 | insn += insn->off; |
| 478 | CONT_JMP; |
| 479 | } |
| 480 | CONT; |
Daniel Borkmann | 5bcfedf | 2014-05-01 18:34:18 +0200 | [diff] [blame] | 481 | JMP_JSET_K: |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 482 | if (A & K) { |
| 483 | insn += insn->off; |
| 484 | CONT_JMP; |
| 485 | } |
| 486 | CONT; |
Daniel Borkmann | 8556ce7 | 2014-05-23 18:43:57 +0200 | [diff] [blame] | 487 | JMP_EXIT: |
David S. Miller | 1268e25 | 2014-05-13 13:13:33 -0400 | [diff] [blame] | 488 | return BPF_R0; |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 489 | |
| 490 | /* STX and ST and LDX*/ |
| 491 | #define LDST(SIZEOP, SIZE) \ |
Daniel Borkmann | 5bcfedf | 2014-05-01 18:34:18 +0200 | [diff] [blame] | 492 | STX_MEM_##SIZEOP: \ |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 493 | *(SIZE *)(unsigned long) (A + insn->off) = X; \ |
| 494 | CONT; \ |
Daniel Borkmann | 5bcfedf | 2014-05-01 18:34:18 +0200 | [diff] [blame] | 495 | ST_MEM_##SIZEOP: \ |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 496 | *(SIZE *)(unsigned long) (A + insn->off) = K; \ |
| 497 | CONT; \ |
Daniel Borkmann | 5bcfedf | 2014-05-01 18:34:18 +0200 | [diff] [blame] | 498 | LDX_MEM_##SIZEOP: \ |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 499 | A = *(SIZE *)(unsigned long) (X + insn->off); \ |
| 500 | CONT; |
| 501 | |
Daniel Borkmann | 5bcfedf | 2014-05-01 18:34:18 +0200 | [diff] [blame] | 502 | LDST(B, u8) |
| 503 | LDST(H, u16) |
| 504 | LDST(W, u32) |
| 505 | LDST(DW, u64) |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 506 | #undef LDST |
Daniel Borkmann | 5bcfedf | 2014-05-01 18:34:18 +0200 | [diff] [blame] | 507 | STX_XADD_W: /* lock xadd *(u32 *)(A + insn->off) += X */ |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 508 | atomic_add((u32) X, (atomic_t *)(unsigned long) |
| 509 | (A + insn->off)); |
| 510 | CONT; |
Daniel Borkmann | 5bcfedf | 2014-05-01 18:34:18 +0200 | [diff] [blame] | 511 | STX_XADD_DW: /* lock xadd *(u64 *)(A + insn->off) += X */ |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 512 | atomic64_add((u64) X, (atomic64_t *)(unsigned long) |
| 513 | (A + insn->off)); |
| 514 | CONT; |
David S. Miller | 1268e25 | 2014-05-13 13:13:33 -0400 | [diff] [blame] | 515 | LD_ABS_W: /* BPF_R0 = ntohl(*(u32 *) (skb->data + K)) */ |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 516 | off = K; |
| 517 | load_word: |
David S. Miller | 1268e25 | 2014-05-13 13:13:33 -0400 | [diff] [blame] | 518 | /* BPF_LD + BPD_ABS and BPF_LD + BPF_IND insns are |
| 519 | * only appearing in the programs where ctx == |
| 520 | * skb. All programs keep 'ctx' in regs[BPF_REG_CTX] |
| 521 | * == BPF_R6, sk_convert_filter() saves it in BPF_R6, |
| 522 | * internal BPF verifier will check that BPF_R6 == |
| 523 | * ctx. |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 524 | * |
David S. Miller | 1268e25 | 2014-05-13 13:13:33 -0400 | [diff] [blame] | 525 | * BPF_ABS and BPF_IND are wrappers of function calls, |
| 526 | * so they scratch BPF_R1-BPF_R5 registers, preserve |
| 527 | * BPF_R6-BPF_R9, and store return value into BPF_R0. |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 528 | * |
| 529 | * Implicit input: |
| 530 | * ctx |
| 531 | * |
| 532 | * Explicit input: |
| 533 | * X == any register |
| 534 | * K == 32-bit immediate |
| 535 | * |
| 536 | * Output: |
David S. Miller | 1268e25 | 2014-05-13 13:13:33 -0400 | [diff] [blame] | 537 | * BPF_R0 - 8/16/32-bit skb data converted to cpu endianness |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 538 | */ |
| 539 | ptr = load_pointer((struct sk_buff *) ctx, off, 4, &tmp); |
| 540 | if (likely(ptr != NULL)) { |
David S. Miller | 1268e25 | 2014-05-13 13:13:33 -0400 | [diff] [blame] | 541 | BPF_R0 = get_unaligned_be32(ptr); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 542 | CONT; |
| 543 | } |
| 544 | return 0; |
David S. Miller | 1268e25 | 2014-05-13 13:13:33 -0400 | [diff] [blame] | 545 | LD_ABS_H: /* BPF_R0 = ntohs(*(u16 *) (skb->data + K)) */ |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 546 | off = K; |
| 547 | load_half: |
| 548 | ptr = load_pointer((struct sk_buff *) ctx, off, 2, &tmp); |
| 549 | if (likely(ptr != NULL)) { |
David S. Miller | 1268e25 | 2014-05-13 13:13:33 -0400 | [diff] [blame] | 550 | BPF_R0 = get_unaligned_be16(ptr); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 551 | CONT; |
| 552 | } |
| 553 | return 0; |
David S. Miller | 1268e25 | 2014-05-13 13:13:33 -0400 | [diff] [blame] | 554 | LD_ABS_B: /* BPF_R0 = *(u8 *) (ctx + K) */ |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 555 | off = K; |
| 556 | load_byte: |
| 557 | ptr = load_pointer((struct sk_buff *) ctx, off, 1, &tmp); |
| 558 | if (likely(ptr != NULL)) { |
David S. Miller | 1268e25 | 2014-05-13 13:13:33 -0400 | [diff] [blame] | 559 | BPF_R0 = *(u8 *)ptr; |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 560 | CONT; |
| 561 | } |
| 562 | return 0; |
David S. Miller | 1268e25 | 2014-05-13 13:13:33 -0400 | [diff] [blame] | 563 | LD_IND_W: /* BPF_R0 = ntohl(*(u32 *) (skb->data + X + K)) */ |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 564 | off = K + X; |
| 565 | goto load_word; |
David S. Miller | 1268e25 | 2014-05-13 13:13:33 -0400 | [diff] [blame] | 566 | LD_IND_H: /* BPF_R0 = ntohs(*(u16 *) (skb->data + X + K)) */ |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 567 | off = K + X; |
| 568 | goto load_half; |
David S. Miller | 1268e25 | 2014-05-13 13:13:33 -0400 | [diff] [blame] | 569 | LD_IND_B: /* BPF_R0 = *(u8 *) (skb->data + X + K) */ |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 570 | off = K + X; |
| 571 | goto load_byte; |
| 572 | |
| 573 | default_label: |
| 574 | /* If we ever reach this, we have a bug somewhere. */ |
| 575 | WARN_RATELIMIT(1, "unknown opcode %02x\n", insn->code); |
| 576 | return 0; |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 577 | } |
| 578 | |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 579 | /* Helper to find the offset of pkt_type in sk_buff structure. We want |
| 580 | * to make sure its still a 3bit field starting at a byte boundary; |
| 581 | * taken from arch/x86/net/bpf_jit_comp.c. |
| 582 | */ |
| 583 | #define PKT_TYPE_MAX 7 |
| 584 | static unsigned int pkt_type_offset(void) |
| 585 | { |
| 586 | struct sk_buff skb_probe = { .pkt_type = ~0, }; |
| 587 | u8 *ct = (u8 *) &skb_probe; |
| 588 | unsigned int off; |
| 589 | |
| 590 | for (off = 0; off < sizeof(struct sk_buff); off++) { |
| 591 | if (ct[off] == PKT_TYPE_MAX) |
| 592 | return off; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 593 | } |
| 594 | |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 595 | pr_err_once("Please fix %s, as pkt_type couldn't be found!\n", __func__); |
| 596 | return -1; |
| 597 | } |
| 598 | |
Daniel Borkmann | 3074383 | 2014-05-01 18:34:19 +0200 | [diff] [blame] | 599 | static u64 __skb_get_pay_offset(u64 ctx, u64 a, u64 x, u64 r4, u64 r5) |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 600 | { |
Daniel Borkmann | eb9672f | 2014-05-01 18:34:20 +0200 | [diff] [blame] | 601 | return __skb_get_poff((struct sk_buff *)(unsigned long) ctx); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 602 | } |
| 603 | |
Daniel Borkmann | 3074383 | 2014-05-01 18:34:19 +0200 | [diff] [blame] | 604 | static u64 __skb_get_nlattr(u64 ctx, u64 a, u64 x, u64 r4, u64 r5) |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 605 | { |
Daniel Borkmann | eb9672f | 2014-05-01 18:34:20 +0200 | [diff] [blame] | 606 | struct sk_buff *skb = (struct sk_buff *)(unsigned long) ctx; |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 607 | struct nlattr *nla; |
| 608 | |
| 609 | if (skb_is_nonlinear(skb)) |
| 610 | return 0; |
| 611 | |
Mathias Krause | 05ab8f2 | 2014-04-13 18:23:33 +0200 | [diff] [blame] | 612 | if (skb->len < sizeof(struct nlattr)) |
| 613 | return 0; |
| 614 | |
Daniel Borkmann | 3074383 | 2014-05-01 18:34:19 +0200 | [diff] [blame] | 615 | if (a > skb->len - sizeof(struct nlattr)) |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 616 | return 0; |
| 617 | |
Daniel Borkmann | 3074383 | 2014-05-01 18:34:19 +0200 | [diff] [blame] | 618 | nla = nla_find((struct nlattr *) &skb->data[a], skb->len - a, x); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 619 | if (nla) |
| 620 | return (void *) nla - (void *) skb->data; |
| 621 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 622 | return 0; |
| 623 | } |
| 624 | |
Daniel Borkmann | 3074383 | 2014-05-01 18:34:19 +0200 | [diff] [blame] | 625 | static u64 __skb_get_nlattr_nest(u64 ctx, u64 a, u64 x, u64 r4, u64 r5) |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 626 | { |
Daniel Borkmann | eb9672f | 2014-05-01 18:34:20 +0200 | [diff] [blame] | 627 | struct sk_buff *skb = (struct sk_buff *)(unsigned long) ctx; |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 628 | struct nlattr *nla; |
| 629 | |
| 630 | if (skb_is_nonlinear(skb)) |
| 631 | return 0; |
| 632 | |
Mathias Krause | 05ab8f2 | 2014-04-13 18:23:33 +0200 | [diff] [blame] | 633 | if (skb->len < sizeof(struct nlattr)) |
| 634 | return 0; |
| 635 | |
Daniel Borkmann | 3074383 | 2014-05-01 18:34:19 +0200 | [diff] [blame] | 636 | if (a > skb->len - sizeof(struct nlattr)) |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 637 | return 0; |
| 638 | |
Daniel Borkmann | 3074383 | 2014-05-01 18:34:19 +0200 | [diff] [blame] | 639 | nla = (struct nlattr *) &skb->data[a]; |
| 640 | if (nla->nla_len > skb->len - a) |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 641 | return 0; |
| 642 | |
Daniel Borkmann | 3074383 | 2014-05-01 18:34:19 +0200 | [diff] [blame] | 643 | nla = nla_find_nested(nla, x); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 644 | if (nla) |
| 645 | return (void *) nla - (void *) skb->data; |
| 646 | |
| 647 | return 0; |
| 648 | } |
| 649 | |
Daniel Borkmann | 3074383 | 2014-05-01 18:34:19 +0200 | [diff] [blame] | 650 | static u64 __get_raw_cpu_id(u64 ctx, u64 a, u64 x, u64 r4, u64 r5) |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 651 | { |
| 652 | return raw_smp_processor_id(); |
| 653 | } |
| 654 | |
Chema Gonzalez | 4cd3675 | 2014-04-21 09:21:24 -0700 | [diff] [blame] | 655 | /* note that this only generates 32-bit random numbers */ |
Daniel Borkmann | 3074383 | 2014-05-01 18:34:19 +0200 | [diff] [blame] | 656 | static u64 __get_random_u32(u64 ctx, u64 a, u64 x, u64 r4, u64 r5) |
Chema Gonzalez | 4cd3675 | 2014-04-21 09:21:24 -0700 | [diff] [blame] | 657 | { |
Daniel Borkmann | eb9672f | 2014-05-01 18:34:20 +0200 | [diff] [blame] | 658 | return prandom_u32(); |
Chema Gonzalez | 4cd3675 | 2014-04-21 09:21:24 -0700 | [diff] [blame] | 659 | } |
| 660 | |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 661 | static bool convert_bpf_extensions(struct sock_filter *fp, |
| 662 | struct sock_filter_int **insnp) |
| 663 | { |
| 664 | struct sock_filter_int *insn = *insnp; |
| 665 | |
| 666 | switch (fp->k) { |
| 667 | case SKF_AD_OFF + SKF_AD_PROTOCOL: |
| 668 | BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, protocol) != 2); |
| 669 | |
Alexei Starovoitov | 9739eef | 2014-05-08 14:10:51 -0700 | [diff] [blame] | 670 | /* A = *(u16 *) (ctx + offsetof(protocol)) */ |
| 671 | *insn = BPF_LDX_MEM(BPF_H, BPF_REG_A, BPF_REG_CTX, |
| 672 | offsetof(struct sk_buff, protocol)); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 673 | insn++; |
| 674 | |
| 675 | /* A = ntohs(A) [emitting a nop or swap16] */ |
| 676 | insn->code = BPF_ALU | BPF_END | BPF_FROM_BE; |
Daniel Borkmann | 3074383 | 2014-05-01 18:34:19 +0200 | [diff] [blame] | 677 | insn->a_reg = BPF_REG_A; |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 678 | insn->imm = 16; |
| 679 | break; |
| 680 | |
| 681 | case SKF_AD_OFF + SKF_AD_PKTTYPE: |
Alexei Starovoitov | 9739eef | 2014-05-08 14:10:51 -0700 | [diff] [blame] | 682 | *insn = BPF_LDX_MEM(BPF_B, BPF_REG_A, BPF_REG_CTX, |
| 683 | pkt_type_offset()); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 684 | if (insn->off < 0) |
| 685 | return false; |
| 686 | insn++; |
| 687 | |
Alexei Starovoitov | 9739eef | 2014-05-08 14:10:51 -0700 | [diff] [blame] | 688 | *insn = BPF_ALU32_IMM(BPF_AND, BPF_REG_A, PKT_TYPE_MAX); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 689 | break; |
| 690 | |
| 691 | case SKF_AD_OFF + SKF_AD_IFINDEX: |
| 692 | case SKF_AD_OFF + SKF_AD_HATYPE: |
Alexei Starovoitov | 9739eef | 2014-05-08 14:10:51 -0700 | [diff] [blame] | 693 | *insn = BPF_LDX_MEM(size_to_bpf(FIELD_SIZEOF(struct sk_buff, dev)), |
| 694 | BPF_REG_TMP, BPF_REG_CTX, |
| 695 | offsetof(struct sk_buff, dev)); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 696 | insn++; |
| 697 | |
Alexei Starovoitov | 9739eef | 2014-05-08 14:10:51 -0700 | [diff] [blame] | 698 | /* if (tmp != 0) goto pc+1 */ |
| 699 | *insn = BPF_JMP_IMM(BPF_JNE, BPF_REG_TMP, 0, 1); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 700 | insn++; |
| 701 | |
Alexei Starovoitov | 9739eef | 2014-05-08 14:10:51 -0700 | [diff] [blame] | 702 | *insn = BPF_EXIT_INSN(); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 703 | insn++; |
| 704 | |
| 705 | BUILD_BUG_ON(FIELD_SIZEOF(struct net_device, ifindex) != 4); |
| 706 | BUILD_BUG_ON(FIELD_SIZEOF(struct net_device, type) != 2); |
| 707 | |
Daniel Borkmann | 3074383 | 2014-05-01 18:34:19 +0200 | [diff] [blame] | 708 | insn->a_reg = BPF_REG_A; |
| 709 | insn->x_reg = BPF_REG_TMP; |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 710 | |
| 711 | if (fp->k == SKF_AD_OFF + SKF_AD_IFINDEX) { |
| 712 | insn->code = BPF_LDX | BPF_MEM | BPF_W; |
| 713 | insn->off = offsetof(struct net_device, ifindex); |
| 714 | } else { |
| 715 | insn->code = BPF_LDX | BPF_MEM | BPF_H; |
| 716 | insn->off = offsetof(struct net_device, type); |
| 717 | } |
| 718 | break; |
| 719 | |
| 720 | case SKF_AD_OFF + SKF_AD_MARK: |
| 721 | BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, mark) != 4); |
| 722 | |
Alexei Starovoitov | 9739eef | 2014-05-08 14:10:51 -0700 | [diff] [blame] | 723 | *insn = BPF_LDX_MEM(BPF_W, BPF_REG_A, BPF_REG_CTX, |
| 724 | offsetof(struct sk_buff, mark)); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 725 | break; |
| 726 | |
| 727 | case SKF_AD_OFF + SKF_AD_RXHASH: |
| 728 | BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, hash) != 4); |
| 729 | |
Alexei Starovoitov | 9739eef | 2014-05-08 14:10:51 -0700 | [diff] [blame] | 730 | *insn = BPF_LDX_MEM(BPF_W, BPF_REG_A, BPF_REG_CTX, |
| 731 | offsetof(struct sk_buff, hash)); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 732 | break; |
| 733 | |
| 734 | case SKF_AD_OFF + SKF_AD_QUEUE: |
| 735 | BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, queue_mapping) != 2); |
| 736 | |
Alexei Starovoitov | 9739eef | 2014-05-08 14:10:51 -0700 | [diff] [blame] | 737 | *insn = BPF_LDX_MEM(BPF_H, BPF_REG_A, BPF_REG_CTX, |
| 738 | offsetof(struct sk_buff, queue_mapping)); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 739 | break; |
| 740 | |
| 741 | case SKF_AD_OFF + SKF_AD_VLAN_TAG: |
| 742 | case SKF_AD_OFF + SKF_AD_VLAN_TAG_PRESENT: |
| 743 | BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, vlan_tci) != 2); |
| 744 | |
Alexei Starovoitov | 9739eef | 2014-05-08 14:10:51 -0700 | [diff] [blame] | 745 | /* A = *(u16 *) (ctx + offsetof(vlan_tci)) */ |
| 746 | *insn = BPF_LDX_MEM(BPF_H, BPF_REG_A, BPF_REG_CTX, |
| 747 | offsetof(struct sk_buff, vlan_tci)); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 748 | insn++; |
| 749 | |
| 750 | BUILD_BUG_ON(VLAN_TAG_PRESENT != 0x1000); |
| 751 | |
| 752 | if (fp->k == SKF_AD_OFF + SKF_AD_VLAN_TAG) { |
Alexei Starovoitov | 9739eef | 2014-05-08 14:10:51 -0700 | [diff] [blame] | 753 | *insn = BPF_ALU32_IMM(BPF_AND, BPF_REG_A, |
| 754 | ~VLAN_TAG_PRESENT); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 755 | } else { |
Alexei Starovoitov | 9739eef | 2014-05-08 14:10:51 -0700 | [diff] [blame] | 756 | /* A >>= 12 */ |
| 757 | *insn = BPF_ALU32_IMM(BPF_RSH, BPF_REG_A, 12); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 758 | insn++; |
| 759 | |
Alexei Starovoitov | 9739eef | 2014-05-08 14:10:51 -0700 | [diff] [blame] | 760 | /* A &= 1 */ |
| 761 | *insn = BPF_ALU32_IMM(BPF_AND, BPF_REG_A, 1); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 762 | } |
| 763 | break; |
| 764 | |
| 765 | case SKF_AD_OFF + SKF_AD_PAY_OFFSET: |
| 766 | case SKF_AD_OFF + SKF_AD_NLATTR: |
| 767 | case SKF_AD_OFF + SKF_AD_NLATTR_NEST: |
| 768 | case SKF_AD_OFF + SKF_AD_CPU: |
Chema Gonzalez | 4cd3675 | 2014-04-21 09:21:24 -0700 | [diff] [blame] | 769 | case SKF_AD_OFF + SKF_AD_RANDOM: |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 770 | /* arg1 = ctx */ |
Alexei Starovoitov | 9739eef | 2014-05-08 14:10:51 -0700 | [diff] [blame] | 771 | *insn = BPF_ALU64_REG(BPF_MOV, BPF_REG_ARG1, BPF_REG_CTX); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 772 | insn++; |
| 773 | |
| 774 | /* arg2 = A */ |
Alexei Starovoitov | 9739eef | 2014-05-08 14:10:51 -0700 | [diff] [blame] | 775 | *insn = BPF_ALU64_REG(BPF_MOV, BPF_REG_ARG2, BPF_REG_A); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 776 | insn++; |
| 777 | |
| 778 | /* arg3 = X */ |
Alexei Starovoitov | 9739eef | 2014-05-08 14:10:51 -0700 | [diff] [blame] | 779 | *insn = BPF_ALU64_REG(BPF_MOV, BPF_REG_ARG3, BPF_REG_X); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 780 | insn++; |
| 781 | |
| 782 | /* Emit call(ctx, arg2=A, arg3=X) */ |
| 783 | insn->code = BPF_JMP | BPF_CALL; |
| 784 | switch (fp->k) { |
| 785 | case SKF_AD_OFF + SKF_AD_PAY_OFFSET: |
| 786 | insn->imm = __skb_get_pay_offset - __bpf_call_base; |
| 787 | break; |
| 788 | case SKF_AD_OFF + SKF_AD_NLATTR: |
| 789 | insn->imm = __skb_get_nlattr - __bpf_call_base; |
| 790 | break; |
| 791 | case SKF_AD_OFF + SKF_AD_NLATTR_NEST: |
| 792 | insn->imm = __skb_get_nlattr_nest - __bpf_call_base; |
| 793 | break; |
| 794 | case SKF_AD_OFF + SKF_AD_CPU: |
| 795 | insn->imm = __get_raw_cpu_id - __bpf_call_base; |
| 796 | break; |
Chema Gonzalez | 4cd3675 | 2014-04-21 09:21:24 -0700 | [diff] [blame] | 797 | case SKF_AD_OFF + SKF_AD_RANDOM: |
| 798 | insn->imm = __get_random_u32 - __bpf_call_base; |
| 799 | break; |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 800 | } |
| 801 | break; |
| 802 | |
| 803 | case SKF_AD_OFF + SKF_AD_ALU_XOR_X: |
Alexei Starovoitov | 9739eef | 2014-05-08 14:10:51 -0700 | [diff] [blame] | 804 | /* A ^= X */ |
| 805 | *insn = BPF_ALU32_REG(BPF_XOR, BPF_REG_A, BPF_REG_X); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 806 | break; |
| 807 | |
| 808 | default: |
| 809 | /* This is just a dummy call to avoid letting the compiler |
| 810 | * evict __bpf_call_base() as an optimization. Placed here |
| 811 | * where no-one bothers. |
| 812 | */ |
| 813 | BUG_ON(__bpf_call_base(0, 0, 0, 0, 0) != 0); |
| 814 | return false; |
| 815 | } |
| 816 | |
| 817 | *insnp = insn; |
| 818 | return true; |
| 819 | } |
| 820 | |
| 821 | /** |
| 822 | * sk_convert_filter - convert filter program |
| 823 | * @prog: the user passed filter program |
| 824 | * @len: the length of the user passed filter program |
| 825 | * @new_prog: buffer where converted program will be stored |
| 826 | * @new_len: pointer to store length of converted program |
| 827 | * |
| 828 | * Remap 'sock_filter' style BPF instruction set to 'sock_filter_ext' style. |
| 829 | * Conversion workflow: |
| 830 | * |
| 831 | * 1) First pass for calculating the new program length: |
| 832 | * sk_convert_filter(old_prog, old_len, NULL, &new_len) |
| 833 | * |
| 834 | * 2) 2nd pass to remap in two passes: 1st pass finds new |
| 835 | * jump offsets, 2nd pass remapping: |
| 836 | * new_prog = kmalloc(sizeof(struct sock_filter_int) * new_len); |
| 837 | * sk_convert_filter(old_prog, old_len, new_prog, &new_len); |
| 838 | * |
| 839 | * User BPF's register A is mapped to our BPF register 6, user BPF |
| 840 | * register X is mapped to BPF register 7; frame pointer is always |
| 841 | * register 10; Context 'void *ctx' is stored in register 1, that is, |
| 842 | * for socket filters: ctx == 'struct sk_buff *', for seccomp: |
| 843 | * ctx == 'struct seccomp_data *'. |
| 844 | */ |
| 845 | int sk_convert_filter(struct sock_filter *prog, int len, |
| 846 | struct sock_filter_int *new_prog, int *new_len) |
| 847 | { |
| 848 | int new_flen = 0, pass = 0, target, i; |
| 849 | struct sock_filter_int *new_insn; |
| 850 | struct sock_filter *fp; |
| 851 | int *addrs = NULL; |
| 852 | u8 bpf_src; |
| 853 | |
| 854 | BUILD_BUG_ON(BPF_MEMWORDS * sizeof(u32) > MAX_BPF_STACK); |
Daniel Borkmann | 3074383 | 2014-05-01 18:34:19 +0200 | [diff] [blame] | 855 | BUILD_BUG_ON(BPF_REG_FP + 1 != MAX_BPF_REG); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 856 | |
| 857 | if (len <= 0 || len >= BPF_MAXINSNS) |
| 858 | return -EINVAL; |
| 859 | |
| 860 | if (new_prog) { |
| 861 | addrs = kzalloc(len * sizeof(*addrs), GFP_KERNEL); |
| 862 | if (!addrs) |
| 863 | return -ENOMEM; |
| 864 | } |
| 865 | |
| 866 | do_pass: |
| 867 | new_insn = new_prog; |
| 868 | fp = prog; |
| 869 | |
| 870 | if (new_insn) { |
Alexei Starovoitov | 9739eef | 2014-05-08 14:10:51 -0700 | [diff] [blame] | 871 | *new_insn = BPF_ALU64_REG(BPF_MOV, BPF_REG_CTX, BPF_REG_ARG1); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 872 | } |
| 873 | new_insn++; |
| 874 | |
| 875 | for (i = 0; i < len; fp++, i++) { |
| 876 | struct sock_filter_int tmp_insns[6] = { }; |
| 877 | struct sock_filter_int *insn = tmp_insns; |
| 878 | |
| 879 | if (addrs) |
| 880 | addrs[i] = new_insn - new_prog; |
| 881 | |
| 882 | switch (fp->code) { |
| 883 | /* All arithmetic insns and skb loads map as-is. */ |
| 884 | case BPF_ALU | BPF_ADD | BPF_X: |
| 885 | case BPF_ALU | BPF_ADD | BPF_K: |
| 886 | case BPF_ALU | BPF_SUB | BPF_X: |
| 887 | case BPF_ALU | BPF_SUB | BPF_K: |
| 888 | case BPF_ALU | BPF_AND | BPF_X: |
| 889 | case BPF_ALU | BPF_AND | BPF_K: |
| 890 | case BPF_ALU | BPF_OR | BPF_X: |
| 891 | case BPF_ALU | BPF_OR | BPF_K: |
| 892 | case BPF_ALU | BPF_LSH | BPF_X: |
| 893 | case BPF_ALU | BPF_LSH | BPF_K: |
| 894 | case BPF_ALU | BPF_RSH | BPF_X: |
| 895 | case BPF_ALU | BPF_RSH | BPF_K: |
| 896 | case BPF_ALU | BPF_XOR | BPF_X: |
| 897 | case BPF_ALU | BPF_XOR | BPF_K: |
| 898 | case BPF_ALU | BPF_MUL | BPF_X: |
| 899 | case BPF_ALU | BPF_MUL | BPF_K: |
| 900 | case BPF_ALU | BPF_DIV | BPF_X: |
| 901 | case BPF_ALU | BPF_DIV | BPF_K: |
| 902 | case BPF_ALU | BPF_MOD | BPF_X: |
| 903 | case BPF_ALU | BPF_MOD | BPF_K: |
| 904 | case BPF_ALU | BPF_NEG: |
| 905 | case BPF_LD | BPF_ABS | BPF_W: |
| 906 | case BPF_LD | BPF_ABS | BPF_H: |
| 907 | case BPF_LD | BPF_ABS | BPF_B: |
| 908 | case BPF_LD | BPF_IND | BPF_W: |
| 909 | case BPF_LD | BPF_IND | BPF_H: |
| 910 | case BPF_LD | BPF_IND | BPF_B: |
| 911 | /* Check for overloaded BPF extension and |
| 912 | * directly convert it if found, otherwise |
| 913 | * just move on with mapping. |
| 914 | */ |
| 915 | if (BPF_CLASS(fp->code) == BPF_LD && |
| 916 | BPF_MODE(fp->code) == BPF_ABS && |
| 917 | convert_bpf_extensions(fp, &insn)) |
| 918 | break; |
| 919 | |
| 920 | insn->code = fp->code; |
Daniel Borkmann | 3074383 | 2014-05-01 18:34:19 +0200 | [diff] [blame] | 921 | insn->a_reg = BPF_REG_A; |
| 922 | insn->x_reg = BPF_REG_X; |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 923 | insn->imm = fp->k; |
| 924 | break; |
| 925 | |
| 926 | /* Jump opcodes map as-is, but offsets need adjustment. */ |
| 927 | case BPF_JMP | BPF_JA: |
| 928 | target = i + fp->k + 1; |
| 929 | insn->code = fp->code; |
| 930 | #define EMIT_JMP \ |
| 931 | do { \ |
| 932 | if (target >= len || target < 0) \ |
| 933 | goto err; \ |
| 934 | insn->off = addrs ? addrs[target] - addrs[i] - 1 : 0; \ |
| 935 | /* Adjust pc relative offset for 2nd or 3rd insn. */ \ |
| 936 | insn->off -= insn - tmp_insns; \ |
| 937 | } while (0) |
| 938 | |
| 939 | EMIT_JMP; |
| 940 | break; |
| 941 | |
| 942 | case BPF_JMP | BPF_JEQ | BPF_K: |
| 943 | case BPF_JMP | BPF_JEQ | BPF_X: |
| 944 | case BPF_JMP | BPF_JSET | BPF_K: |
| 945 | case BPF_JMP | BPF_JSET | BPF_X: |
| 946 | case BPF_JMP | BPF_JGT | BPF_K: |
| 947 | case BPF_JMP | BPF_JGT | BPF_X: |
| 948 | case BPF_JMP | BPF_JGE | BPF_K: |
| 949 | case BPF_JMP | BPF_JGE | BPF_X: |
| 950 | if (BPF_SRC(fp->code) == BPF_K && (int) fp->k < 0) { |
| 951 | /* BPF immediates are signed, zero extend |
| 952 | * immediate into tmp register and use it |
| 953 | * in compare insn. |
| 954 | */ |
| 955 | insn->code = BPF_ALU | BPF_MOV | BPF_K; |
Daniel Borkmann | 3074383 | 2014-05-01 18:34:19 +0200 | [diff] [blame] | 956 | insn->a_reg = BPF_REG_TMP; |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 957 | insn->imm = fp->k; |
| 958 | insn++; |
| 959 | |
Daniel Borkmann | 3074383 | 2014-05-01 18:34:19 +0200 | [diff] [blame] | 960 | insn->a_reg = BPF_REG_A; |
| 961 | insn->x_reg = BPF_REG_TMP; |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 962 | bpf_src = BPF_X; |
| 963 | } else { |
Daniel Borkmann | 3074383 | 2014-05-01 18:34:19 +0200 | [diff] [blame] | 964 | insn->a_reg = BPF_REG_A; |
| 965 | insn->x_reg = BPF_REG_X; |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 966 | insn->imm = fp->k; |
| 967 | bpf_src = BPF_SRC(fp->code); |
| 968 | } |
| 969 | |
| 970 | /* Common case where 'jump_false' is next insn. */ |
| 971 | if (fp->jf == 0) { |
| 972 | insn->code = BPF_JMP | BPF_OP(fp->code) | bpf_src; |
| 973 | target = i + fp->jt + 1; |
| 974 | EMIT_JMP; |
| 975 | break; |
| 976 | } |
| 977 | |
| 978 | /* Convert JEQ into JNE when 'jump_true' is next insn. */ |
| 979 | if (fp->jt == 0 && BPF_OP(fp->code) == BPF_JEQ) { |
| 980 | insn->code = BPF_JMP | BPF_JNE | bpf_src; |
| 981 | target = i + fp->jf + 1; |
| 982 | EMIT_JMP; |
| 983 | break; |
| 984 | } |
| 985 | |
| 986 | /* Other jumps are mapped into two insns: Jxx and JA. */ |
| 987 | target = i + fp->jt + 1; |
| 988 | insn->code = BPF_JMP | BPF_OP(fp->code) | bpf_src; |
| 989 | EMIT_JMP; |
| 990 | insn++; |
| 991 | |
| 992 | insn->code = BPF_JMP | BPF_JA; |
| 993 | target = i + fp->jf + 1; |
| 994 | EMIT_JMP; |
| 995 | break; |
| 996 | |
| 997 | /* ldxb 4 * ([14] & 0xf) is remaped into 6 insns. */ |
| 998 | case BPF_LDX | BPF_MSH | BPF_B: |
Alexei Starovoitov | 9739eef | 2014-05-08 14:10:51 -0700 | [diff] [blame] | 999 | /* tmp = A */ |
| 1000 | *insn = BPF_ALU64_REG(BPF_MOV, BPF_REG_TMP, BPF_REG_A); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 1001 | insn++; |
| 1002 | |
David S. Miller | 1268e25 | 2014-05-13 13:13:33 -0400 | [diff] [blame] | 1003 | /* A = BPF_R0 = *(u8 *) (skb->data + K) */ |
Alexei Starovoitov | 9739eef | 2014-05-08 14:10:51 -0700 | [diff] [blame] | 1004 | *insn = BPF_LD_ABS(BPF_B, fp->k); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 1005 | insn++; |
| 1006 | |
Alexei Starovoitov | 9739eef | 2014-05-08 14:10:51 -0700 | [diff] [blame] | 1007 | /* A &= 0xf */ |
| 1008 | *insn = BPF_ALU32_IMM(BPF_AND, BPF_REG_A, 0xf); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 1009 | insn++; |
| 1010 | |
Alexei Starovoitov | 9739eef | 2014-05-08 14:10:51 -0700 | [diff] [blame] | 1011 | /* A <<= 2 */ |
| 1012 | *insn = BPF_ALU32_IMM(BPF_LSH, BPF_REG_A, 2); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 1013 | insn++; |
| 1014 | |
Alexei Starovoitov | 9739eef | 2014-05-08 14:10:51 -0700 | [diff] [blame] | 1015 | /* X = A */ |
| 1016 | *insn = BPF_ALU64_REG(BPF_MOV, BPF_REG_X, BPF_REG_A); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 1017 | insn++; |
| 1018 | |
Alexei Starovoitov | 9739eef | 2014-05-08 14:10:51 -0700 | [diff] [blame] | 1019 | /* A = tmp */ |
| 1020 | *insn = BPF_ALU64_REG(BPF_MOV, BPF_REG_A, BPF_REG_TMP); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 1021 | break; |
| 1022 | |
| 1023 | /* RET_K, RET_A are remaped into 2 insns. */ |
| 1024 | case BPF_RET | BPF_A: |
| 1025 | case BPF_RET | BPF_K: |
| 1026 | insn->code = BPF_ALU | BPF_MOV | |
| 1027 | (BPF_RVAL(fp->code) == BPF_K ? |
| 1028 | BPF_K : BPF_X); |
| 1029 | insn->a_reg = 0; |
Daniel Borkmann | 3074383 | 2014-05-01 18:34:19 +0200 | [diff] [blame] | 1030 | insn->x_reg = BPF_REG_A; |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 1031 | insn->imm = fp->k; |
| 1032 | insn++; |
| 1033 | |
Alexei Starovoitov | 9739eef | 2014-05-08 14:10:51 -0700 | [diff] [blame] | 1034 | *insn = BPF_EXIT_INSN(); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 1035 | break; |
| 1036 | |
| 1037 | /* Store to stack. */ |
| 1038 | case BPF_ST: |
| 1039 | case BPF_STX: |
| 1040 | insn->code = BPF_STX | BPF_MEM | BPF_W; |
Daniel Borkmann | 3074383 | 2014-05-01 18:34:19 +0200 | [diff] [blame] | 1041 | insn->a_reg = BPF_REG_FP; |
| 1042 | insn->x_reg = fp->code == BPF_ST ? |
| 1043 | BPF_REG_A : BPF_REG_X; |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 1044 | insn->off = -(BPF_MEMWORDS - fp->k) * 4; |
| 1045 | break; |
| 1046 | |
| 1047 | /* Load from stack. */ |
| 1048 | case BPF_LD | BPF_MEM: |
| 1049 | case BPF_LDX | BPF_MEM: |
| 1050 | insn->code = BPF_LDX | BPF_MEM | BPF_W; |
| 1051 | insn->a_reg = BPF_CLASS(fp->code) == BPF_LD ? |
Daniel Borkmann | 3074383 | 2014-05-01 18:34:19 +0200 | [diff] [blame] | 1052 | BPF_REG_A : BPF_REG_X; |
| 1053 | insn->x_reg = BPF_REG_FP; |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 1054 | insn->off = -(BPF_MEMWORDS - fp->k) * 4; |
| 1055 | break; |
| 1056 | |
| 1057 | /* A = K or X = K */ |
| 1058 | case BPF_LD | BPF_IMM: |
| 1059 | case BPF_LDX | BPF_IMM: |
| 1060 | insn->code = BPF_ALU | BPF_MOV | BPF_K; |
| 1061 | insn->a_reg = BPF_CLASS(fp->code) == BPF_LD ? |
Daniel Borkmann | 3074383 | 2014-05-01 18:34:19 +0200 | [diff] [blame] | 1062 | BPF_REG_A : BPF_REG_X; |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 1063 | insn->imm = fp->k; |
| 1064 | break; |
| 1065 | |
| 1066 | /* X = A */ |
| 1067 | case BPF_MISC | BPF_TAX: |
Alexei Starovoitov | 9739eef | 2014-05-08 14:10:51 -0700 | [diff] [blame] | 1068 | *insn = BPF_ALU64_REG(BPF_MOV, BPF_REG_X, BPF_REG_A); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 1069 | break; |
| 1070 | |
| 1071 | /* A = X */ |
| 1072 | case BPF_MISC | BPF_TXA: |
Alexei Starovoitov | 9739eef | 2014-05-08 14:10:51 -0700 | [diff] [blame] | 1073 | *insn = BPF_ALU64_REG(BPF_MOV, BPF_REG_A, BPF_REG_X); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 1074 | break; |
| 1075 | |
| 1076 | /* A = skb->len or X = skb->len */ |
| 1077 | case BPF_LD | BPF_W | BPF_LEN: |
| 1078 | case BPF_LDX | BPF_W | BPF_LEN: |
| 1079 | insn->code = BPF_LDX | BPF_MEM | BPF_W; |
| 1080 | insn->a_reg = BPF_CLASS(fp->code) == BPF_LD ? |
Daniel Borkmann | 3074383 | 2014-05-01 18:34:19 +0200 | [diff] [blame] | 1081 | BPF_REG_A : BPF_REG_X; |
| 1082 | insn->x_reg = BPF_REG_CTX; |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 1083 | insn->off = offsetof(struct sk_buff, len); |
| 1084 | break; |
| 1085 | |
| 1086 | /* access seccomp_data fields */ |
| 1087 | case BPF_LDX | BPF_ABS | BPF_W: |
Alexei Starovoitov | 9739eef | 2014-05-08 14:10:51 -0700 | [diff] [blame] | 1088 | /* A = *(u32 *) (ctx + K) */ |
| 1089 | *insn = BPF_LDX_MEM(BPF_W, BPF_REG_A, BPF_REG_CTX, fp->k); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 1090 | break; |
| 1091 | |
| 1092 | default: |
| 1093 | goto err; |
| 1094 | } |
| 1095 | |
| 1096 | insn++; |
| 1097 | if (new_prog) |
| 1098 | memcpy(new_insn, tmp_insns, |
| 1099 | sizeof(*insn) * (insn - tmp_insns)); |
| 1100 | |
| 1101 | new_insn += insn - tmp_insns; |
| 1102 | } |
| 1103 | |
| 1104 | if (!new_prog) { |
| 1105 | /* Only calculating new length. */ |
| 1106 | *new_len = new_insn - new_prog; |
| 1107 | return 0; |
| 1108 | } |
| 1109 | |
| 1110 | pass++; |
| 1111 | if (new_flen != new_insn - new_prog) { |
| 1112 | new_flen = new_insn - new_prog; |
| 1113 | if (pass > 2) |
| 1114 | goto err; |
| 1115 | |
| 1116 | goto do_pass; |
| 1117 | } |
| 1118 | |
| 1119 | kfree(addrs); |
| 1120 | BUG_ON(*new_len != new_flen); |
| 1121 | return 0; |
| 1122 | err: |
| 1123 | kfree(addrs); |
| 1124 | return -EINVAL; |
| 1125 | } |
| 1126 | |
| 1127 | /* Security: |
| 1128 | * |
Eric Dumazet | 2d5311e | 2010-12-01 20:46:24 +0000 | [diff] [blame] | 1129 | * A BPF program is able to use 16 cells of memory to store intermediate |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 1130 | * values (check u32 mem[BPF_MEMWORDS] in sk_run_filter()). |
| 1131 | * |
Eric Dumazet | 2d5311e | 2010-12-01 20:46:24 +0000 | [diff] [blame] | 1132 | * As we dont want to clear mem[] array for each packet going through |
| 1133 | * sk_run_filter(), we check that filter loaded by user never try to read |
| 1134 | * 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] | 1135 | * a malicious user doesn't try to abuse us. |
Eric Dumazet | 2d5311e | 2010-12-01 20:46:24 +0000 | [diff] [blame] | 1136 | */ |
| 1137 | static int check_load_and_stores(struct sock_filter *filter, int flen) |
| 1138 | { |
| 1139 | u16 *masks, memvalid = 0; /* one bit per cell, 16 cells */ |
| 1140 | int pc, ret = 0; |
| 1141 | |
| 1142 | BUILD_BUG_ON(BPF_MEMWORDS > 16); |
| 1143 | masks = kmalloc(flen * sizeof(*masks), GFP_KERNEL); |
| 1144 | if (!masks) |
| 1145 | return -ENOMEM; |
| 1146 | memset(masks, 0xff, flen * sizeof(*masks)); |
| 1147 | |
| 1148 | for (pc = 0; pc < flen; pc++) { |
| 1149 | memvalid &= masks[pc]; |
| 1150 | |
| 1151 | switch (filter[pc].code) { |
| 1152 | case BPF_S_ST: |
| 1153 | case BPF_S_STX: |
| 1154 | memvalid |= (1 << filter[pc].k); |
| 1155 | break; |
| 1156 | case BPF_S_LD_MEM: |
| 1157 | case BPF_S_LDX_MEM: |
| 1158 | if (!(memvalid & (1 << filter[pc].k))) { |
| 1159 | ret = -EINVAL; |
| 1160 | goto error; |
| 1161 | } |
| 1162 | break; |
| 1163 | case BPF_S_JMP_JA: |
| 1164 | /* a jump must set masks on target */ |
| 1165 | masks[pc + 1 + filter[pc].k] &= memvalid; |
| 1166 | memvalid = ~0; |
| 1167 | break; |
| 1168 | case BPF_S_JMP_JEQ_K: |
| 1169 | case BPF_S_JMP_JEQ_X: |
| 1170 | case BPF_S_JMP_JGE_K: |
| 1171 | case BPF_S_JMP_JGE_X: |
| 1172 | case BPF_S_JMP_JGT_K: |
| 1173 | case BPF_S_JMP_JGT_X: |
| 1174 | case BPF_S_JMP_JSET_X: |
| 1175 | case BPF_S_JMP_JSET_K: |
| 1176 | /* a jump must set masks on targets */ |
| 1177 | masks[pc + 1 + filter[pc].jt] &= memvalid; |
| 1178 | masks[pc + 1 + filter[pc].jf] &= memvalid; |
| 1179 | memvalid = ~0; |
| 1180 | break; |
| 1181 | } |
| 1182 | } |
| 1183 | error: |
| 1184 | kfree(masks); |
| 1185 | return ret; |
| 1186 | } |
| 1187 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1188 | /** |
| 1189 | * sk_chk_filter - verify socket filter code |
| 1190 | * @filter: filter to verify |
| 1191 | * @flen: length of filter |
| 1192 | * |
| 1193 | * Check the user's filter code. If we let some ugly |
| 1194 | * filter code slip through kaboom! The filter must contain |
Kris Katterjohn | 9369986 | 2006-01-04 13:58:36 -0800 | [diff] [blame] | 1195 | * no references or jumps that are out of range, no illegal |
| 1196 | * instructions, and must end with a RET instruction. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1197 | * |
Kris Katterjohn | 7b11f69 | 2006-01-13 14:33:06 -0800 | [diff] [blame] | 1198 | * All jumps are forward as they are not signed. |
| 1199 | * |
| 1200 | * Returns 0 if the rule set is legal or -EINVAL if not. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1201 | */ |
Dan Carpenter | 4f25af2 | 2011-10-17 21:04:20 +0000 | [diff] [blame] | 1202 | int sk_chk_filter(struct sock_filter *filter, unsigned int flen) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1203 | { |
Tetsuo Handa | cba328f | 2010-11-16 15:19:51 +0000 | [diff] [blame] | 1204 | /* |
| 1205 | * Valid instructions are initialized to non-0. |
| 1206 | * Invalid instructions are initialized to 0. |
| 1207 | */ |
| 1208 | static const u8 codes[] = { |
Eric Dumazet | 8c1592d | 2010-11-18 21:56:38 +0000 | [diff] [blame] | 1209 | [BPF_ALU|BPF_ADD|BPF_K] = BPF_S_ALU_ADD_K, |
| 1210 | [BPF_ALU|BPF_ADD|BPF_X] = BPF_S_ALU_ADD_X, |
| 1211 | [BPF_ALU|BPF_SUB|BPF_K] = BPF_S_ALU_SUB_K, |
| 1212 | [BPF_ALU|BPF_SUB|BPF_X] = BPF_S_ALU_SUB_X, |
| 1213 | [BPF_ALU|BPF_MUL|BPF_K] = BPF_S_ALU_MUL_K, |
| 1214 | [BPF_ALU|BPF_MUL|BPF_X] = BPF_S_ALU_MUL_X, |
| 1215 | [BPF_ALU|BPF_DIV|BPF_X] = BPF_S_ALU_DIV_X, |
Eric Dumazet | b6069a9 | 2012-09-07 22:03:35 +0000 | [diff] [blame] | 1216 | [BPF_ALU|BPF_MOD|BPF_K] = BPF_S_ALU_MOD_K, |
| 1217 | [BPF_ALU|BPF_MOD|BPF_X] = BPF_S_ALU_MOD_X, |
Eric Dumazet | 8c1592d | 2010-11-18 21:56:38 +0000 | [diff] [blame] | 1218 | [BPF_ALU|BPF_AND|BPF_K] = BPF_S_ALU_AND_K, |
| 1219 | [BPF_ALU|BPF_AND|BPF_X] = BPF_S_ALU_AND_X, |
| 1220 | [BPF_ALU|BPF_OR|BPF_K] = BPF_S_ALU_OR_K, |
| 1221 | [BPF_ALU|BPF_OR|BPF_X] = BPF_S_ALU_OR_X, |
Daniel Borkmann | 9e49e88 | 2012-09-24 02:23:59 +0000 | [diff] [blame] | 1222 | [BPF_ALU|BPF_XOR|BPF_K] = BPF_S_ALU_XOR_K, |
| 1223 | [BPF_ALU|BPF_XOR|BPF_X] = BPF_S_ALU_XOR_X, |
Eric Dumazet | 8c1592d | 2010-11-18 21:56:38 +0000 | [diff] [blame] | 1224 | [BPF_ALU|BPF_LSH|BPF_K] = BPF_S_ALU_LSH_K, |
| 1225 | [BPF_ALU|BPF_LSH|BPF_X] = BPF_S_ALU_LSH_X, |
| 1226 | [BPF_ALU|BPF_RSH|BPF_K] = BPF_S_ALU_RSH_K, |
| 1227 | [BPF_ALU|BPF_RSH|BPF_X] = BPF_S_ALU_RSH_X, |
| 1228 | [BPF_ALU|BPF_NEG] = BPF_S_ALU_NEG, |
| 1229 | [BPF_LD|BPF_W|BPF_ABS] = BPF_S_LD_W_ABS, |
| 1230 | [BPF_LD|BPF_H|BPF_ABS] = BPF_S_LD_H_ABS, |
| 1231 | [BPF_LD|BPF_B|BPF_ABS] = BPF_S_LD_B_ABS, |
| 1232 | [BPF_LD|BPF_W|BPF_LEN] = BPF_S_LD_W_LEN, |
| 1233 | [BPF_LD|BPF_W|BPF_IND] = BPF_S_LD_W_IND, |
| 1234 | [BPF_LD|BPF_H|BPF_IND] = BPF_S_LD_H_IND, |
| 1235 | [BPF_LD|BPF_B|BPF_IND] = BPF_S_LD_B_IND, |
| 1236 | [BPF_LD|BPF_IMM] = BPF_S_LD_IMM, |
| 1237 | [BPF_LDX|BPF_W|BPF_LEN] = BPF_S_LDX_W_LEN, |
| 1238 | [BPF_LDX|BPF_B|BPF_MSH] = BPF_S_LDX_B_MSH, |
| 1239 | [BPF_LDX|BPF_IMM] = BPF_S_LDX_IMM, |
| 1240 | [BPF_MISC|BPF_TAX] = BPF_S_MISC_TAX, |
| 1241 | [BPF_MISC|BPF_TXA] = BPF_S_MISC_TXA, |
| 1242 | [BPF_RET|BPF_K] = BPF_S_RET_K, |
| 1243 | [BPF_RET|BPF_A] = BPF_S_RET_A, |
| 1244 | [BPF_ALU|BPF_DIV|BPF_K] = BPF_S_ALU_DIV_K, |
| 1245 | [BPF_LD|BPF_MEM] = BPF_S_LD_MEM, |
| 1246 | [BPF_LDX|BPF_MEM] = BPF_S_LDX_MEM, |
| 1247 | [BPF_ST] = BPF_S_ST, |
| 1248 | [BPF_STX] = BPF_S_STX, |
| 1249 | [BPF_JMP|BPF_JA] = BPF_S_JMP_JA, |
| 1250 | [BPF_JMP|BPF_JEQ|BPF_K] = BPF_S_JMP_JEQ_K, |
| 1251 | [BPF_JMP|BPF_JEQ|BPF_X] = BPF_S_JMP_JEQ_X, |
| 1252 | [BPF_JMP|BPF_JGE|BPF_K] = BPF_S_JMP_JGE_K, |
| 1253 | [BPF_JMP|BPF_JGE|BPF_X] = BPF_S_JMP_JGE_X, |
| 1254 | [BPF_JMP|BPF_JGT|BPF_K] = BPF_S_JMP_JGT_K, |
| 1255 | [BPF_JMP|BPF_JGT|BPF_X] = BPF_S_JMP_JGT_X, |
| 1256 | [BPF_JMP|BPF_JSET|BPF_K] = BPF_S_JMP_JSET_K, |
| 1257 | [BPF_JMP|BPF_JSET|BPF_X] = BPF_S_JMP_JSET_X, |
Tetsuo Handa | cba328f | 2010-11-16 15:19:51 +0000 | [diff] [blame] | 1258 | }; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1259 | int pc; |
Daniel Borkmann | aa1113d | 2012-12-28 10:50:17 +0000 | [diff] [blame] | 1260 | bool anc_found; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1261 | |
David S. Miller | 1b93ae64 | 2005-12-27 13:57:59 -0800 | [diff] [blame] | 1262 | if (flen == 0 || flen > BPF_MAXINSNS) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1263 | return -EINVAL; |
| 1264 | |
| 1265 | /* check the filter code now */ |
| 1266 | for (pc = 0; pc < flen; pc++) { |
Tetsuo Handa | cba328f | 2010-11-16 15:19:51 +0000 | [diff] [blame] | 1267 | struct sock_filter *ftest = &filter[pc]; |
| 1268 | u16 code = ftest->code; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1269 | |
Tetsuo Handa | cba328f | 2010-11-16 15:19:51 +0000 | [diff] [blame] | 1270 | if (code >= ARRAY_SIZE(codes)) |
| 1271 | return -EINVAL; |
| 1272 | code = codes[code]; |
Eric Dumazet | 8c1592d | 2010-11-18 21:56:38 +0000 | [diff] [blame] | 1273 | if (!code) |
Tetsuo Handa | cba328f | 2010-11-16 15:19:51 +0000 | [diff] [blame] | 1274 | return -EINVAL; |
Kris Katterjohn | 9369986 | 2006-01-04 13:58:36 -0800 | [diff] [blame] | 1275 | /* Some instructions need special checks */ |
Tetsuo Handa | cba328f | 2010-11-16 15:19:51 +0000 | [diff] [blame] | 1276 | switch (code) { |
| 1277 | case BPF_S_ALU_DIV_K: |
Eric Dumazet | b6069a9 | 2012-09-07 22:03:35 +0000 | [diff] [blame] | 1278 | case BPF_S_ALU_MOD_K: |
| 1279 | /* check for division by zero */ |
| 1280 | if (ftest->k == 0) |
| 1281 | return -EINVAL; |
| 1282 | break; |
Tetsuo Handa | cba328f | 2010-11-16 15:19:51 +0000 | [diff] [blame] | 1283 | case BPF_S_LD_MEM: |
| 1284 | case BPF_S_LDX_MEM: |
| 1285 | case BPF_S_ST: |
| 1286 | case BPF_S_STX: |
| 1287 | /* check for invalid memory addresses */ |
Kris Katterjohn | 9369986 | 2006-01-04 13:58:36 -0800 | [diff] [blame] | 1288 | if (ftest->k >= BPF_MEMWORDS) |
| 1289 | return -EINVAL; |
Hagen Paul Pfeifer | 01f2f3f | 2010-06-19 17:05:36 +0000 | [diff] [blame] | 1290 | break; |
Tetsuo Handa | cba328f | 2010-11-16 15:19:51 +0000 | [diff] [blame] | 1291 | case BPF_S_JMP_JA: |
Kris Katterjohn | 9369986 | 2006-01-04 13:58:36 -0800 | [diff] [blame] | 1292 | /* |
| 1293 | * Note, the large ftest->k might cause loops. |
| 1294 | * Compare this with conditional jumps below, |
| 1295 | * where offsets are limited. --ANK (981016) |
| 1296 | */ |
Eric Dumazet | 95c9617 | 2012-04-15 05:58:06 +0000 | [diff] [blame] | 1297 | if (ftest->k >= (unsigned int)(flen-pc-1)) |
Kris Katterjohn | 9369986 | 2006-01-04 13:58:36 -0800 | [diff] [blame] | 1298 | return -EINVAL; |
| 1299 | break; |
Hagen Paul Pfeifer | 01f2f3f | 2010-06-19 17:05:36 +0000 | [diff] [blame] | 1300 | case BPF_S_JMP_JEQ_K: |
| 1301 | case BPF_S_JMP_JEQ_X: |
| 1302 | case BPF_S_JMP_JGE_K: |
| 1303 | case BPF_S_JMP_JGE_X: |
| 1304 | case BPF_S_JMP_JGT_K: |
| 1305 | case BPF_S_JMP_JGT_X: |
| 1306 | case BPF_S_JMP_JSET_X: |
| 1307 | case BPF_S_JMP_JSET_K: |
Tetsuo Handa | cba328f | 2010-11-16 15:19:51 +0000 | [diff] [blame] | 1308 | /* for conditionals both must be safe */ |
Hagen Paul Pfeifer | 01f2f3f | 2010-06-19 17:05:36 +0000 | [diff] [blame] | 1309 | if (pc + ftest->jt + 1 >= flen || |
| 1310 | pc + ftest->jf + 1 >= flen) |
| 1311 | return -EINVAL; |
Tetsuo Handa | cba328f | 2010-11-16 15:19:51 +0000 | [diff] [blame] | 1312 | break; |
Eric Dumazet | 12b16da | 2010-12-15 19:45:28 +0000 | [diff] [blame] | 1313 | case BPF_S_LD_W_ABS: |
| 1314 | case BPF_S_LD_H_ABS: |
| 1315 | case BPF_S_LD_B_ABS: |
Daniel Borkmann | aa1113d | 2012-12-28 10:50:17 +0000 | [diff] [blame] | 1316 | anc_found = false; |
Eric Dumazet | 12b16da | 2010-12-15 19:45:28 +0000 | [diff] [blame] | 1317 | #define ANCILLARY(CODE) case SKF_AD_OFF + SKF_AD_##CODE: \ |
| 1318 | code = BPF_S_ANC_##CODE; \ |
Daniel Borkmann | aa1113d | 2012-12-28 10:50:17 +0000 | [diff] [blame] | 1319 | anc_found = true; \ |
Eric Dumazet | 12b16da | 2010-12-15 19:45:28 +0000 | [diff] [blame] | 1320 | break |
| 1321 | switch (ftest->k) { |
| 1322 | ANCILLARY(PROTOCOL); |
| 1323 | ANCILLARY(PKTTYPE); |
| 1324 | ANCILLARY(IFINDEX); |
| 1325 | ANCILLARY(NLATTR); |
| 1326 | ANCILLARY(NLATTR_NEST); |
| 1327 | ANCILLARY(MARK); |
| 1328 | ANCILLARY(QUEUE); |
| 1329 | ANCILLARY(HATYPE); |
| 1330 | ANCILLARY(RXHASH); |
| 1331 | ANCILLARY(CPU); |
Jiri Pirko | ffe06c1 | 2012-03-31 11:01:20 +0000 | [diff] [blame] | 1332 | ANCILLARY(ALU_XOR_X); |
Eric Dumazet | f333503 | 2012-10-27 02:26:17 +0000 | [diff] [blame] | 1333 | ANCILLARY(VLAN_TAG); |
| 1334 | ANCILLARY(VLAN_TAG_PRESENT); |
Daniel Borkmann | 3e5289d | 2013-03-19 06:39:31 +0000 | [diff] [blame] | 1335 | ANCILLARY(PAY_OFFSET); |
Chema Gonzalez | 4cd3675 | 2014-04-21 09:21:24 -0700 | [diff] [blame] | 1336 | ANCILLARY(RANDOM); |
Eric Dumazet | 12b16da | 2010-12-15 19:45:28 +0000 | [diff] [blame] | 1337 | } |
Daniel Borkmann | aa1113d | 2012-12-28 10:50:17 +0000 | [diff] [blame] | 1338 | |
| 1339 | /* ancillary operation unknown or unsupported */ |
| 1340 | if (anc_found == false && ftest->k >= SKF_AD_OFF) |
| 1341 | return -EINVAL; |
Hagen Paul Pfeifer | 01f2f3f | 2010-06-19 17:05:36 +0000 | [diff] [blame] | 1342 | } |
Tetsuo Handa | cba328f | 2010-11-16 15:19:51 +0000 | [diff] [blame] | 1343 | ftest->code = code; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1344 | } |
| 1345 | |
Hagen Paul Pfeifer | 01f2f3f | 2010-06-19 17:05:36 +0000 | [diff] [blame] | 1346 | /* last instruction must be a RET code */ |
| 1347 | switch (filter[flen - 1].code) { |
| 1348 | case BPF_S_RET_K: |
| 1349 | case BPF_S_RET_A: |
Eric Dumazet | 2d5311e | 2010-12-01 20:46:24 +0000 | [diff] [blame] | 1350 | return check_load_and_stores(filter, flen); |
Tetsuo Handa | cba328f | 2010-11-16 15:19:51 +0000 | [diff] [blame] | 1351 | } |
| 1352 | return -EINVAL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1353 | } |
Stephen Hemminger | b715631 | 2008-04-10 01:33:47 -0700 | [diff] [blame] | 1354 | EXPORT_SYMBOL(sk_chk_filter); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1355 | |
Daniel Borkmann | a3ea269 | 2014-03-28 18:58:19 +0100 | [diff] [blame] | 1356 | static int sk_store_orig_filter(struct sk_filter *fp, |
| 1357 | const struct sock_fprog *fprog) |
| 1358 | { |
| 1359 | unsigned int fsize = sk_filter_proglen(fprog); |
| 1360 | struct sock_fprog_kern *fkprog; |
| 1361 | |
| 1362 | fp->orig_prog = kmalloc(sizeof(*fkprog), GFP_KERNEL); |
| 1363 | if (!fp->orig_prog) |
| 1364 | return -ENOMEM; |
| 1365 | |
| 1366 | fkprog = fp->orig_prog; |
| 1367 | fkprog->len = fprog->len; |
| 1368 | fkprog->filter = kmemdup(fp->insns, fsize, GFP_KERNEL); |
| 1369 | if (!fkprog->filter) { |
| 1370 | kfree(fp->orig_prog); |
| 1371 | return -ENOMEM; |
| 1372 | } |
| 1373 | |
| 1374 | return 0; |
| 1375 | } |
| 1376 | |
| 1377 | static void sk_release_orig_filter(struct sk_filter *fp) |
| 1378 | { |
| 1379 | struct sock_fprog_kern *fprog = fp->orig_prog; |
| 1380 | |
| 1381 | if (fprog) { |
| 1382 | kfree(fprog->filter); |
| 1383 | kfree(fprog); |
| 1384 | } |
| 1385 | } |
| 1386 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1387 | /** |
Eric Dumazet | 46bcf14 | 2010-12-06 09:29:43 -0800 | [diff] [blame] | 1388 | * sk_filter_release_rcu - Release a socket filter by rcu_head |
Pavel Emelyanov | 47e958e | 2007-10-17 21:22:42 -0700 | [diff] [blame] | 1389 | * @rcu: rcu_head that contains the sk_filter to free |
| 1390 | */ |
Daniel Borkmann | fbc907f | 2014-03-28 18:58:20 +0100 | [diff] [blame] | 1391 | static void sk_filter_release_rcu(struct rcu_head *rcu) |
Pavel Emelyanov | 47e958e | 2007-10-17 21:22:42 -0700 | [diff] [blame] | 1392 | { |
| 1393 | struct sk_filter *fp = container_of(rcu, struct sk_filter, rcu); |
| 1394 | |
Daniel Borkmann | a3ea269 | 2014-03-28 18:58:19 +0100 | [diff] [blame] | 1395 | sk_release_orig_filter(fp); |
Alexei Starovoitov | 5fe821a | 2014-05-19 14:56:14 -0700 | [diff] [blame] | 1396 | sk_filter_free(fp); |
Pavel Emelyanov | 47e958e | 2007-10-17 21:22:42 -0700 | [diff] [blame] | 1397 | } |
Daniel Borkmann | fbc907f | 2014-03-28 18:58:20 +0100 | [diff] [blame] | 1398 | |
| 1399 | /** |
| 1400 | * sk_filter_release - release a socket filter |
| 1401 | * @fp: filter to remove |
| 1402 | * |
| 1403 | * Remove a filter from a socket and release its resources. |
| 1404 | */ |
| 1405 | static void sk_filter_release(struct sk_filter *fp) |
| 1406 | { |
| 1407 | if (atomic_dec_and_test(&fp->refcnt)) |
| 1408 | call_rcu(&fp->rcu, sk_filter_release_rcu); |
| 1409 | } |
| 1410 | |
| 1411 | void sk_filter_uncharge(struct sock *sk, struct sk_filter *fp) |
| 1412 | { |
| 1413 | atomic_sub(sk_filter_size(fp->len), &sk->sk_omem_alloc); |
| 1414 | sk_filter_release(fp); |
| 1415 | } |
| 1416 | |
| 1417 | void sk_filter_charge(struct sock *sk, struct sk_filter *fp) |
| 1418 | { |
| 1419 | atomic_inc(&fp->refcnt); |
| 1420 | atomic_add(sk_filter_size(fp->len), &sk->sk_omem_alloc); |
| 1421 | } |
Pavel Emelyanov | 47e958e | 2007-10-17 21:22:42 -0700 | [diff] [blame] | 1422 | |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 1423 | static struct sk_filter *__sk_migrate_realloc(struct sk_filter *fp, |
| 1424 | struct sock *sk, |
| 1425 | unsigned int len) |
| 1426 | { |
| 1427 | struct sk_filter *fp_new; |
| 1428 | |
| 1429 | if (sk == NULL) |
| 1430 | return krealloc(fp, len, GFP_KERNEL); |
| 1431 | |
| 1432 | fp_new = sock_kmalloc(sk, len, GFP_KERNEL); |
| 1433 | if (fp_new) { |
Daniel Borkmann | eb9672f | 2014-05-01 18:34:20 +0200 | [diff] [blame] | 1434 | *fp_new = *fp; |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 1435 | /* As we're kepping orig_prog in fp_new along, |
| 1436 | * we need to make sure we're not evicting it |
| 1437 | * from the old fp. |
| 1438 | */ |
| 1439 | fp->orig_prog = NULL; |
| 1440 | sk_filter_uncharge(sk, fp); |
| 1441 | } |
| 1442 | |
| 1443 | return fp_new; |
| 1444 | } |
| 1445 | |
| 1446 | static struct sk_filter *__sk_migrate_filter(struct sk_filter *fp, |
| 1447 | struct sock *sk) |
| 1448 | { |
| 1449 | struct sock_filter *old_prog; |
| 1450 | struct sk_filter *old_fp; |
| 1451 | int i, err, new_len, old_len = fp->len; |
| 1452 | |
| 1453 | /* We are free to overwrite insns et al right here as it |
| 1454 | * won't be used at this point in time anymore internally |
| 1455 | * after the migration to the internal BPF instruction |
| 1456 | * representation. |
| 1457 | */ |
| 1458 | BUILD_BUG_ON(sizeof(struct sock_filter) != |
| 1459 | sizeof(struct sock_filter_int)); |
| 1460 | |
| 1461 | /* For now, we need to unfiddle BPF_S_* identifiers in place. |
| 1462 | * This can sooner or later on be subject to removal, e.g. when |
| 1463 | * JITs have been converted. |
| 1464 | */ |
| 1465 | for (i = 0; i < fp->len; i++) |
| 1466 | sk_decode_filter(&fp->insns[i], &fp->insns[i]); |
| 1467 | |
| 1468 | /* Conversion cannot happen on overlapping memory areas, |
| 1469 | * so we need to keep the user BPF around until the 2nd |
| 1470 | * pass. At this time, the user BPF is stored in fp->insns. |
| 1471 | */ |
| 1472 | old_prog = kmemdup(fp->insns, old_len * sizeof(struct sock_filter), |
| 1473 | GFP_KERNEL); |
| 1474 | if (!old_prog) { |
| 1475 | err = -ENOMEM; |
| 1476 | goto out_err; |
| 1477 | } |
| 1478 | |
| 1479 | /* 1st pass: calculate the new program length. */ |
| 1480 | err = sk_convert_filter(old_prog, old_len, NULL, &new_len); |
| 1481 | if (err) |
| 1482 | goto out_err_free; |
| 1483 | |
| 1484 | /* Expand fp for appending the new filter representation. */ |
| 1485 | old_fp = fp; |
| 1486 | fp = __sk_migrate_realloc(old_fp, sk, sk_filter_size(new_len)); |
| 1487 | if (!fp) { |
| 1488 | /* The old_fp is still around in case we couldn't |
| 1489 | * allocate new memory, so uncharge on that one. |
| 1490 | */ |
| 1491 | fp = old_fp; |
| 1492 | err = -ENOMEM; |
| 1493 | goto out_err_free; |
| 1494 | } |
| 1495 | |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 1496 | fp->len = new_len; |
| 1497 | |
| 1498 | /* 2nd pass: remap sock_filter insns into sock_filter_int insns. */ |
| 1499 | err = sk_convert_filter(old_prog, old_len, fp->insnsi, &new_len); |
| 1500 | if (err) |
| 1501 | /* 2nd sk_convert_filter() can fail only if it fails |
| 1502 | * to allocate memory, remapping must succeed. Note, |
| 1503 | * that at this time old_fp has already been released |
| 1504 | * by __sk_migrate_realloc(). |
| 1505 | */ |
| 1506 | goto out_err_free; |
| 1507 | |
Alexei Starovoitov | 5fe821a | 2014-05-19 14:56:14 -0700 | [diff] [blame] | 1508 | sk_filter_select_runtime(fp); |
| 1509 | |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 1510 | kfree(old_prog); |
| 1511 | return fp; |
| 1512 | |
| 1513 | out_err_free: |
| 1514 | kfree(old_prog); |
| 1515 | out_err: |
| 1516 | /* Rollback filter setup. */ |
| 1517 | if (sk != NULL) |
| 1518 | sk_filter_uncharge(sk, fp); |
| 1519 | else |
| 1520 | kfree(fp); |
| 1521 | return ERR_PTR(err); |
| 1522 | } |
| 1523 | |
Alexei Starovoitov | 6225827 | 2014-05-13 19:50:46 -0700 | [diff] [blame] | 1524 | void __weak bpf_int_jit_compile(struct sk_filter *prog) |
| 1525 | { |
| 1526 | } |
| 1527 | |
Alexei Starovoitov | 5fe821a | 2014-05-19 14:56:14 -0700 | [diff] [blame] | 1528 | /** |
| 1529 | * sk_filter_select_runtime - select execution runtime for BPF program |
| 1530 | * @fp: sk_filter populated with internal BPF program |
| 1531 | * |
| 1532 | * try to JIT internal BPF program, if JIT is not available select interpreter |
| 1533 | * BPF program will be executed via SK_RUN_FILTER() macro |
| 1534 | */ |
| 1535 | void sk_filter_select_runtime(struct sk_filter *fp) |
| 1536 | { |
| 1537 | fp->bpf_func = (void *) __sk_run_filter; |
| 1538 | |
| 1539 | /* Probe if internal BPF can be JITed */ |
| 1540 | bpf_int_jit_compile(fp); |
| 1541 | } |
| 1542 | EXPORT_SYMBOL_GPL(sk_filter_select_runtime); |
| 1543 | |
| 1544 | /* free internal BPF program */ |
| 1545 | void sk_filter_free(struct sk_filter *fp) |
| 1546 | { |
| 1547 | bpf_jit_free(fp); |
| 1548 | } |
| 1549 | EXPORT_SYMBOL_GPL(sk_filter_free); |
| 1550 | |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 1551 | static struct sk_filter *__sk_prepare_filter(struct sk_filter *fp, |
| 1552 | struct sock *sk) |
Jiri Pirko | 302d663 | 2012-03-31 11:01:19 +0000 | [diff] [blame] | 1553 | { |
| 1554 | int err; |
| 1555 | |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 1556 | fp->bpf_func = NULL; |
Daniel Borkmann | f8bbbfc | 2014-03-28 18:58:18 +0100 | [diff] [blame] | 1557 | fp->jited = 0; |
Jiri Pirko | 302d663 | 2012-03-31 11:01:19 +0000 | [diff] [blame] | 1558 | |
| 1559 | err = sk_chk_filter(fp->insns, fp->len); |
| 1560 | if (err) |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 1561 | return ERR_PTR(err); |
Jiri Pirko | 302d663 | 2012-03-31 11:01:19 +0000 | [diff] [blame] | 1562 | |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 1563 | /* Probe if we can JIT compile the filter and if so, do |
| 1564 | * the compilation of the filter. |
| 1565 | */ |
Jiri Pirko | 302d663 | 2012-03-31 11:01:19 +0000 | [diff] [blame] | 1566 | bpf_jit_compile(fp); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 1567 | |
| 1568 | /* JIT compiler couldn't process this filter, so do the |
| 1569 | * internal BPF translation for the optimized interpreter. |
| 1570 | */ |
Alexei Starovoitov | 5fe821a | 2014-05-19 14:56:14 -0700 | [diff] [blame] | 1571 | if (!fp->jited) |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 1572 | fp = __sk_migrate_filter(fp, sk); |
| 1573 | |
| 1574 | return fp; |
Jiri Pirko | 302d663 | 2012-03-31 11:01:19 +0000 | [diff] [blame] | 1575 | } |
| 1576 | |
| 1577 | /** |
| 1578 | * sk_unattached_filter_create - create an unattached filter |
| 1579 | * @fprog: the filter program |
Randy Dunlap | c6c4b97 | 2012-06-08 14:01:44 +0000 | [diff] [blame] | 1580 | * @pfp: the unattached filter that is created |
Jiri Pirko | 302d663 | 2012-03-31 11:01:19 +0000 | [diff] [blame] | 1581 | * |
Randy Dunlap | c6c4b97 | 2012-06-08 14:01:44 +0000 | [diff] [blame] | 1582 | * Create a filter independent of any socket. We first run some |
Jiri Pirko | 302d663 | 2012-03-31 11:01:19 +0000 | [diff] [blame] | 1583 | * sanity checks on it to make sure it does not explode on us later. |
| 1584 | * If an error occurs or there is insufficient memory for the filter |
| 1585 | * a negative errno code is returned. On success the return is zero. |
| 1586 | */ |
| 1587 | int sk_unattached_filter_create(struct sk_filter **pfp, |
Daniel Borkmann | b1fcd35 | 2014-05-23 18:43:58 +0200 | [diff] [blame^] | 1588 | struct sock_fprog_kern *fprog) |
Jiri Pirko | 302d663 | 2012-03-31 11:01:19 +0000 | [diff] [blame] | 1589 | { |
Daniel Borkmann | a3ea269 | 2014-03-28 18:58:19 +0100 | [diff] [blame] | 1590 | unsigned int fsize = sk_filter_proglen(fprog); |
Jiri Pirko | 302d663 | 2012-03-31 11:01:19 +0000 | [diff] [blame] | 1591 | struct sk_filter *fp; |
Jiri Pirko | 302d663 | 2012-03-31 11:01:19 +0000 | [diff] [blame] | 1592 | |
| 1593 | /* Make sure new filter is there and in the right amounts. */ |
| 1594 | if (fprog->filter == NULL) |
| 1595 | return -EINVAL; |
| 1596 | |
Alexei Starovoitov | d45ed4a | 2013-10-04 00:14:06 -0700 | [diff] [blame] | 1597 | fp = kmalloc(sk_filter_size(fprog->len), GFP_KERNEL); |
Jiri Pirko | 302d663 | 2012-03-31 11:01:19 +0000 | [diff] [blame] | 1598 | if (!fp) |
| 1599 | return -ENOMEM; |
Daniel Borkmann | a3ea269 | 2014-03-28 18:58:19 +0100 | [diff] [blame] | 1600 | |
Jiri Pirko | 302d663 | 2012-03-31 11:01:19 +0000 | [diff] [blame] | 1601 | memcpy(fp->insns, fprog->filter, fsize); |
| 1602 | |
| 1603 | atomic_set(&fp->refcnt, 1); |
| 1604 | fp->len = fprog->len; |
Daniel Borkmann | a3ea269 | 2014-03-28 18:58:19 +0100 | [diff] [blame] | 1605 | /* Since unattached filters are not copied back to user |
| 1606 | * space through sk_get_filter(), we do not need to hold |
| 1607 | * a copy here, and can spare us the work. |
| 1608 | */ |
| 1609 | fp->orig_prog = NULL; |
Jiri Pirko | 302d663 | 2012-03-31 11:01:19 +0000 | [diff] [blame] | 1610 | |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 1611 | /* __sk_prepare_filter() already takes care of uncharging |
| 1612 | * memory in case something goes wrong. |
| 1613 | */ |
| 1614 | fp = __sk_prepare_filter(fp, NULL); |
| 1615 | if (IS_ERR(fp)) |
| 1616 | return PTR_ERR(fp); |
Jiri Pirko | 302d663 | 2012-03-31 11:01:19 +0000 | [diff] [blame] | 1617 | |
| 1618 | *pfp = fp; |
| 1619 | return 0; |
Jiri Pirko | 302d663 | 2012-03-31 11:01:19 +0000 | [diff] [blame] | 1620 | } |
| 1621 | EXPORT_SYMBOL_GPL(sk_unattached_filter_create); |
| 1622 | |
| 1623 | void sk_unattached_filter_destroy(struct sk_filter *fp) |
| 1624 | { |
| 1625 | sk_filter_release(fp); |
| 1626 | } |
| 1627 | EXPORT_SYMBOL_GPL(sk_unattached_filter_destroy); |
| 1628 | |
Pavel Emelyanov | 47e958e | 2007-10-17 21:22:42 -0700 | [diff] [blame] | 1629 | /** |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1630 | * sk_attach_filter - attach a socket filter |
| 1631 | * @fprog: the filter program |
| 1632 | * @sk: the socket to use |
| 1633 | * |
| 1634 | * Attach the user's filter code. We first run some sanity checks on |
| 1635 | * it to make sure it does not explode on us later. If an error |
| 1636 | * occurs or there is insufficient memory for the filter a negative |
| 1637 | * errno code is returned. On success the return is zero. |
| 1638 | */ |
| 1639 | int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk) |
| 1640 | { |
Pavel Emelyanov | d3904b7 | 2007-10-17 21:22:17 -0700 | [diff] [blame] | 1641 | struct sk_filter *fp, *old_fp; |
Daniel Borkmann | a3ea269 | 2014-03-28 18:58:19 +0100 | [diff] [blame] | 1642 | unsigned int fsize = sk_filter_proglen(fprog); |
Alexei Starovoitov | d45ed4a | 2013-10-04 00:14:06 -0700 | [diff] [blame] | 1643 | unsigned int sk_fsize = sk_filter_size(fprog->len); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1644 | int err; |
| 1645 | |
Vincent Bernat | d59577b | 2013-01-16 22:55:49 +0100 | [diff] [blame] | 1646 | if (sock_flag(sk, SOCK_FILTER_LOCKED)) |
| 1647 | return -EPERM; |
| 1648 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1649 | /* Make sure new filter is there and in the right amounts. */ |
Kris Katterjohn | e35bedf | 2006-01-17 02:25:52 -0800 | [diff] [blame] | 1650 | if (fprog->filter == NULL) |
| 1651 | return -EINVAL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1652 | |
Alexei Starovoitov | d45ed4a | 2013-10-04 00:14:06 -0700 | [diff] [blame] | 1653 | fp = sock_kmalloc(sk, sk_fsize, GFP_KERNEL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1654 | if (!fp) |
| 1655 | return -ENOMEM; |
Daniel Borkmann | a3ea269 | 2014-03-28 18:58:19 +0100 | [diff] [blame] | 1656 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1657 | if (copy_from_user(fp->insns, fprog->filter, fsize)) { |
Alexei Starovoitov | d45ed4a | 2013-10-04 00:14:06 -0700 | [diff] [blame] | 1658 | sock_kfree_s(sk, fp, sk_fsize); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1659 | return -EFAULT; |
| 1660 | } |
| 1661 | |
| 1662 | atomic_set(&fp->refcnt, 1); |
| 1663 | fp->len = fprog->len; |
| 1664 | |
Daniel Borkmann | a3ea269 | 2014-03-28 18:58:19 +0100 | [diff] [blame] | 1665 | err = sk_store_orig_filter(fp, fprog); |
| 1666 | if (err) { |
| 1667 | sk_filter_uncharge(sk, fp); |
| 1668 | return -ENOMEM; |
| 1669 | } |
| 1670 | |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 1671 | /* __sk_prepare_filter() already takes care of uncharging |
| 1672 | * memory in case something goes wrong. |
| 1673 | */ |
| 1674 | fp = __sk_prepare_filter(fp, sk); |
| 1675 | if (IS_ERR(fp)) |
| 1676 | return PTR_ERR(fp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1677 | |
Eric Dumazet | f91ff5b | 2010-09-27 06:07:30 +0000 | [diff] [blame] | 1678 | old_fp = rcu_dereference_protected(sk->sk_filter, |
| 1679 | sock_owned_by_user(sk)); |
Pavel Emelyanov | d3904b7 | 2007-10-17 21:22:17 -0700 | [diff] [blame] | 1680 | rcu_assign_pointer(sk->sk_filter, fp); |
Pavel Emelyanov | d3904b7 | 2007-10-17 21:22:17 -0700 | [diff] [blame] | 1681 | |
Olof Johansson | 9b013e0 | 2007-10-18 21:48:39 -0700 | [diff] [blame] | 1682 | if (old_fp) |
Eric Dumazet | 46bcf14 | 2010-12-06 09:29:43 -0800 | [diff] [blame] | 1683 | sk_filter_uncharge(sk, old_fp); |
Daniel Borkmann | a3ea269 | 2014-03-28 18:58:19 +0100 | [diff] [blame] | 1684 | |
Pavel Emelyanov | d3904b7 | 2007-10-17 21:22:17 -0700 | [diff] [blame] | 1685 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1686 | } |
Michael S. Tsirkin | 5ff3f07 | 2010-02-14 01:01:00 +0000 | [diff] [blame] | 1687 | EXPORT_SYMBOL_GPL(sk_attach_filter); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1688 | |
Pavel Emelyanov | 55b3332 | 2007-10-17 21:21:26 -0700 | [diff] [blame] | 1689 | int sk_detach_filter(struct sock *sk) |
| 1690 | { |
| 1691 | int ret = -ENOENT; |
| 1692 | struct sk_filter *filter; |
| 1693 | |
Vincent Bernat | d59577b | 2013-01-16 22:55:49 +0100 | [diff] [blame] | 1694 | if (sock_flag(sk, SOCK_FILTER_LOCKED)) |
| 1695 | return -EPERM; |
| 1696 | |
Eric Dumazet | f91ff5b | 2010-09-27 06:07:30 +0000 | [diff] [blame] | 1697 | filter = rcu_dereference_protected(sk->sk_filter, |
| 1698 | sock_owned_by_user(sk)); |
Pavel Emelyanov | 55b3332 | 2007-10-17 21:21:26 -0700 | [diff] [blame] | 1699 | if (filter) { |
Stephen Hemminger | a9b3cd7 | 2011-08-01 16:19:00 +0000 | [diff] [blame] | 1700 | RCU_INIT_POINTER(sk->sk_filter, NULL); |
Eric Dumazet | 46bcf14 | 2010-12-06 09:29:43 -0800 | [diff] [blame] | 1701 | sk_filter_uncharge(sk, filter); |
Pavel Emelyanov | 55b3332 | 2007-10-17 21:21:26 -0700 | [diff] [blame] | 1702 | ret = 0; |
| 1703 | } |
Daniel Borkmann | a3ea269 | 2014-03-28 18:58:19 +0100 | [diff] [blame] | 1704 | |
Pavel Emelyanov | 55b3332 | 2007-10-17 21:21:26 -0700 | [diff] [blame] | 1705 | return ret; |
| 1706 | } |
Michael S. Tsirkin | 5ff3f07 | 2010-02-14 01:01:00 +0000 | [diff] [blame] | 1707 | EXPORT_SYMBOL_GPL(sk_detach_filter); |
Pavel Emelyanov | a8fc927 | 2012-11-01 02:01:48 +0000 | [diff] [blame] | 1708 | |
Nicolas Dichtel | ed13998 | 2013-06-05 15:30:55 +0200 | [diff] [blame] | 1709 | void sk_decode_filter(struct sock_filter *filt, struct sock_filter *to) |
Pavel Emelyanov | a8fc927 | 2012-11-01 02:01:48 +0000 | [diff] [blame] | 1710 | { |
| 1711 | static const u16 decodes[] = { |
| 1712 | [BPF_S_ALU_ADD_K] = BPF_ALU|BPF_ADD|BPF_K, |
| 1713 | [BPF_S_ALU_ADD_X] = BPF_ALU|BPF_ADD|BPF_X, |
| 1714 | [BPF_S_ALU_SUB_K] = BPF_ALU|BPF_SUB|BPF_K, |
| 1715 | [BPF_S_ALU_SUB_X] = BPF_ALU|BPF_SUB|BPF_X, |
| 1716 | [BPF_S_ALU_MUL_K] = BPF_ALU|BPF_MUL|BPF_K, |
| 1717 | [BPF_S_ALU_MUL_X] = BPF_ALU|BPF_MUL|BPF_X, |
| 1718 | [BPF_S_ALU_DIV_X] = BPF_ALU|BPF_DIV|BPF_X, |
| 1719 | [BPF_S_ALU_MOD_K] = BPF_ALU|BPF_MOD|BPF_K, |
| 1720 | [BPF_S_ALU_MOD_X] = BPF_ALU|BPF_MOD|BPF_X, |
| 1721 | [BPF_S_ALU_AND_K] = BPF_ALU|BPF_AND|BPF_K, |
| 1722 | [BPF_S_ALU_AND_X] = BPF_ALU|BPF_AND|BPF_X, |
| 1723 | [BPF_S_ALU_OR_K] = BPF_ALU|BPF_OR|BPF_K, |
| 1724 | [BPF_S_ALU_OR_X] = BPF_ALU|BPF_OR|BPF_X, |
| 1725 | [BPF_S_ALU_XOR_K] = BPF_ALU|BPF_XOR|BPF_K, |
| 1726 | [BPF_S_ALU_XOR_X] = BPF_ALU|BPF_XOR|BPF_X, |
| 1727 | [BPF_S_ALU_LSH_K] = BPF_ALU|BPF_LSH|BPF_K, |
| 1728 | [BPF_S_ALU_LSH_X] = BPF_ALU|BPF_LSH|BPF_X, |
| 1729 | [BPF_S_ALU_RSH_K] = BPF_ALU|BPF_RSH|BPF_K, |
| 1730 | [BPF_S_ALU_RSH_X] = BPF_ALU|BPF_RSH|BPF_X, |
| 1731 | [BPF_S_ALU_NEG] = BPF_ALU|BPF_NEG, |
| 1732 | [BPF_S_LD_W_ABS] = BPF_LD|BPF_W|BPF_ABS, |
| 1733 | [BPF_S_LD_H_ABS] = BPF_LD|BPF_H|BPF_ABS, |
| 1734 | [BPF_S_LD_B_ABS] = BPF_LD|BPF_B|BPF_ABS, |
| 1735 | [BPF_S_ANC_PROTOCOL] = BPF_LD|BPF_B|BPF_ABS, |
| 1736 | [BPF_S_ANC_PKTTYPE] = BPF_LD|BPF_B|BPF_ABS, |
| 1737 | [BPF_S_ANC_IFINDEX] = BPF_LD|BPF_B|BPF_ABS, |
| 1738 | [BPF_S_ANC_NLATTR] = BPF_LD|BPF_B|BPF_ABS, |
| 1739 | [BPF_S_ANC_NLATTR_NEST] = BPF_LD|BPF_B|BPF_ABS, |
| 1740 | [BPF_S_ANC_MARK] = BPF_LD|BPF_B|BPF_ABS, |
| 1741 | [BPF_S_ANC_QUEUE] = BPF_LD|BPF_B|BPF_ABS, |
| 1742 | [BPF_S_ANC_HATYPE] = BPF_LD|BPF_B|BPF_ABS, |
| 1743 | [BPF_S_ANC_RXHASH] = BPF_LD|BPF_B|BPF_ABS, |
| 1744 | [BPF_S_ANC_CPU] = BPF_LD|BPF_B|BPF_ABS, |
| 1745 | [BPF_S_ANC_ALU_XOR_X] = BPF_LD|BPF_B|BPF_ABS, |
Pavel Emelyanov | a8fc927 | 2012-11-01 02:01:48 +0000 | [diff] [blame] | 1746 | [BPF_S_ANC_VLAN_TAG] = BPF_LD|BPF_B|BPF_ABS, |
| 1747 | [BPF_S_ANC_VLAN_TAG_PRESENT] = BPF_LD|BPF_B|BPF_ABS, |
Daniel Borkmann | 3e5289d | 2013-03-19 06:39:31 +0000 | [diff] [blame] | 1748 | [BPF_S_ANC_PAY_OFFSET] = BPF_LD|BPF_B|BPF_ABS, |
Chema Gonzalez | 4cd3675 | 2014-04-21 09:21:24 -0700 | [diff] [blame] | 1749 | [BPF_S_ANC_RANDOM] = BPF_LD|BPF_B|BPF_ABS, |
Pavel Emelyanov | a8fc927 | 2012-11-01 02:01:48 +0000 | [diff] [blame] | 1750 | [BPF_S_LD_W_LEN] = BPF_LD|BPF_W|BPF_LEN, |
| 1751 | [BPF_S_LD_W_IND] = BPF_LD|BPF_W|BPF_IND, |
| 1752 | [BPF_S_LD_H_IND] = BPF_LD|BPF_H|BPF_IND, |
| 1753 | [BPF_S_LD_B_IND] = BPF_LD|BPF_B|BPF_IND, |
| 1754 | [BPF_S_LD_IMM] = BPF_LD|BPF_IMM, |
| 1755 | [BPF_S_LDX_W_LEN] = BPF_LDX|BPF_W|BPF_LEN, |
| 1756 | [BPF_S_LDX_B_MSH] = BPF_LDX|BPF_B|BPF_MSH, |
| 1757 | [BPF_S_LDX_IMM] = BPF_LDX|BPF_IMM, |
| 1758 | [BPF_S_MISC_TAX] = BPF_MISC|BPF_TAX, |
| 1759 | [BPF_S_MISC_TXA] = BPF_MISC|BPF_TXA, |
| 1760 | [BPF_S_RET_K] = BPF_RET|BPF_K, |
| 1761 | [BPF_S_RET_A] = BPF_RET|BPF_A, |
| 1762 | [BPF_S_ALU_DIV_K] = BPF_ALU|BPF_DIV|BPF_K, |
| 1763 | [BPF_S_LD_MEM] = BPF_LD|BPF_MEM, |
| 1764 | [BPF_S_LDX_MEM] = BPF_LDX|BPF_MEM, |
| 1765 | [BPF_S_ST] = BPF_ST, |
| 1766 | [BPF_S_STX] = BPF_STX, |
| 1767 | [BPF_S_JMP_JA] = BPF_JMP|BPF_JA, |
| 1768 | [BPF_S_JMP_JEQ_K] = BPF_JMP|BPF_JEQ|BPF_K, |
| 1769 | [BPF_S_JMP_JEQ_X] = BPF_JMP|BPF_JEQ|BPF_X, |
| 1770 | [BPF_S_JMP_JGE_K] = BPF_JMP|BPF_JGE|BPF_K, |
| 1771 | [BPF_S_JMP_JGE_X] = BPF_JMP|BPF_JGE|BPF_X, |
| 1772 | [BPF_S_JMP_JGT_K] = BPF_JMP|BPF_JGT|BPF_K, |
| 1773 | [BPF_S_JMP_JGT_X] = BPF_JMP|BPF_JGT|BPF_X, |
| 1774 | [BPF_S_JMP_JSET_K] = BPF_JMP|BPF_JSET|BPF_K, |
| 1775 | [BPF_S_JMP_JSET_X] = BPF_JMP|BPF_JSET|BPF_X, |
| 1776 | }; |
| 1777 | u16 code; |
| 1778 | |
| 1779 | code = filt->code; |
| 1780 | |
| 1781 | to->code = decodes[code]; |
| 1782 | to->jt = filt->jt; |
| 1783 | to->jf = filt->jf; |
Eric Dumazet | aee636c | 2014-01-15 06:50:07 -0800 | [diff] [blame] | 1784 | to->k = filt->k; |
Pavel Emelyanov | a8fc927 | 2012-11-01 02:01:48 +0000 | [diff] [blame] | 1785 | } |
| 1786 | |
Daniel Borkmann | a3ea269 | 2014-03-28 18:58:19 +0100 | [diff] [blame] | 1787 | int sk_get_filter(struct sock *sk, struct sock_filter __user *ubuf, |
| 1788 | unsigned int len) |
Pavel Emelyanov | a8fc927 | 2012-11-01 02:01:48 +0000 | [diff] [blame] | 1789 | { |
Daniel Borkmann | a3ea269 | 2014-03-28 18:58:19 +0100 | [diff] [blame] | 1790 | struct sock_fprog_kern *fprog; |
Pavel Emelyanov | a8fc927 | 2012-11-01 02:01:48 +0000 | [diff] [blame] | 1791 | struct sk_filter *filter; |
Daniel Borkmann | a3ea269 | 2014-03-28 18:58:19 +0100 | [diff] [blame] | 1792 | int ret = 0; |
Pavel Emelyanov | a8fc927 | 2012-11-01 02:01:48 +0000 | [diff] [blame] | 1793 | |
| 1794 | lock_sock(sk); |
| 1795 | filter = rcu_dereference_protected(sk->sk_filter, |
Daniel Borkmann | a3ea269 | 2014-03-28 18:58:19 +0100 | [diff] [blame] | 1796 | sock_owned_by_user(sk)); |
Pavel Emelyanov | a8fc927 | 2012-11-01 02:01:48 +0000 | [diff] [blame] | 1797 | if (!filter) |
| 1798 | goto out; |
Daniel Borkmann | a3ea269 | 2014-03-28 18:58:19 +0100 | [diff] [blame] | 1799 | |
| 1800 | /* We're copying the filter that has been originally attached, |
| 1801 | * so no conversion/decode needed anymore. |
| 1802 | */ |
| 1803 | fprog = filter->orig_prog; |
| 1804 | |
| 1805 | ret = fprog->len; |
Pavel Emelyanov | a8fc927 | 2012-11-01 02:01:48 +0000 | [diff] [blame] | 1806 | if (!len) |
Daniel Borkmann | a3ea269 | 2014-03-28 18:58:19 +0100 | [diff] [blame] | 1807 | /* User space only enquires number of filter blocks. */ |
Pavel Emelyanov | a8fc927 | 2012-11-01 02:01:48 +0000 | [diff] [blame] | 1808 | goto out; |
Daniel Borkmann | a3ea269 | 2014-03-28 18:58:19 +0100 | [diff] [blame] | 1809 | |
Pavel Emelyanov | a8fc927 | 2012-11-01 02:01:48 +0000 | [diff] [blame] | 1810 | ret = -EINVAL; |
Daniel Borkmann | a3ea269 | 2014-03-28 18:58:19 +0100 | [diff] [blame] | 1811 | if (len < fprog->len) |
Pavel Emelyanov | a8fc927 | 2012-11-01 02:01:48 +0000 | [diff] [blame] | 1812 | goto out; |
| 1813 | |
| 1814 | ret = -EFAULT; |
Daniel Borkmann | a3ea269 | 2014-03-28 18:58:19 +0100 | [diff] [blame] | 1815 | if (copy_to_user(ubuf, fprog->filter, sk_filter_proglen(fprog))) |
| 1816 | goto out; |
Pavel Emelyanov | a8fc927 | 2012-11-01 02:01:48 +0000 | [diff] [blame] | 1817 | |
Daniel Borkmann | a3ea269 | 2014-03-28 18:58:19 +0100 | [diff] [blame] | 1818 | /* Instead of bytes, the API requests to return the number |
| 1819 | * of filter blocks. |
| 1820 | */ |
| 1821 | ret = fprog->len; |
Pavel Emelyanov | a8fc927 | 2012-11-01 02:01:48 +0000 | [diff] [blame] | 1822 | out: |
| 1823 | release_sock(sk); |
| 1824 | return ret; |
| 1825 | } |