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 | |
Jan Seiffert | f03fb3f | 2012-03-30 05:08:19 +0000 | [diff] [blame] | 48 | /* No hurry in this branch |
| 49 | * |
| 50 | * Exported for the bpf jit load helper. |
| 51 | */ |
| 52 | 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] | 53 | { |
| 54 | u8 *ptr = NULL; |
| 55 | |
| 56 | if (k >= SKF_NET_OFF) |
Arnaldo Carvalho de Melo | d56f90a | 2007-04-10 20:50:43 -0700 | [diff] [blame] | 57 | ptr = skb_network_header(skb) + k - SKF_NET_OFF; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 58 | else if (k >= SKF_LL_OFF) |
Arnaldo Carvalho de Melo | 98e399f | 2007-03-19 15:33:04 -0700 | [diff] [blame] | 59 | ptr = skb_mac_header(skb) + k - SKF_LL_OFF; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 60 | |
Eric Dumazet | 4bc65dd | 2010-12-07 22:26:15 +0000 | [diff] [blame] | 61 | if (ptr >= skb->head && ptr + size <= skb_tail_pointer(skb)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 62 | return ptr; |
| 63 | return NULL; |
| 64 | } |
| 65 | |
Eric Dumazet | 62ab081 | 2010-12-06 20:50:09 +0000 | [diff] [blame] | 66 | static inline void *load_pointer(const struct sk_buff *skb, int k, |
YOSHIFUJI Hideaki | 4ec93ed | 2007-02-09 23:24:36 +0900 | [diff] [blame] | 67 | unsigned int size, void *buffer) |
Patrick McHardy | 0b05b2a | 2005-07-05 14:10:21 -0700 | [diff] [blame] | 68 | { |
| 69 | if (k >= 0) |
| 70 | return skb_header_pointer(skb, k, size, buffer); |
Jan Seiffert | f03fb3f | 2012-03-30 05:08:19 +0000 | [diff] [blame] | 71 | return bpf_internal_load_pointer_neg_helper(skb, k, size); |
Patrick McHardy | 0b05b2a | 2005-07-05 14:10:21 -0700 | [diff] [blame] | 72 | } |
| 73 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 74 | /** |
Stephen Hemminger | 43db6d6 | 2008-04-10 01:43:09 -0700 | [diff] [blame] | 75 | * sk_filter - run a packet through a socket filter |
| 76 | * @sk: sock associated with &sk_buff |
| 77 | * @skb: buffer to filter |
Stephen Hemminger | 43db6d6 | 2008-04-10 01:43:09 -0700 | [diff] [blame] | 78 | * |
| 79 | * Run the filter code and then cut skb->data to correct size returned by |
| 80 | * sk_run_filter. If pkt_len is 0 we toss packet. If skb->len is smaller |
| 81 | * than pkt_len we keep whole skb->data. This is the socket level |
| 82 | * wrapper to sk_run_filter. It returns 0 if the packet should |
| 83 | * be accepted or -EPERM if the packet should be tossed. |
| 84 | * |
| 85 | */ |
| 86 | int sk_filter(struct sock *sk, struct sk_buff *skb) |
| 87 | { |
| 88 | int err; |
| 89 | struct sk_filter *filter; |
| 90 | |
Mel Gorman | c93bdd0 | 2012-07-31 16:44:19 -0700 | [diff] [blame] | 91 | /* |
| 92 | * If the skb was allocated from pfmemalloc reserves, only |
| 93 | * allow SOCK_MEMALLOC sockets to use it as this socket is |
| 94 | * helping free memory |
| 95 | */ |
| 96 | if (skb_pfmemalloc(skb) && !sock_flag(sk, SOCK_MEMALLOC)) |
| 97 | return -ENOMEM; |
| 98 | |
Stephen Hemminger | 43db6d6 | 2008-04-10 01:43:09 -0700 | [diff] [blame] | 99 | err = security_sock_rcv_skb(sk, skb); |
| 100 | if (err) |
| 101 | return err; |
| 102 | |
Eric Dumazet | 80f8f10 | 2011-01-18 07:46:52 +0000 | [diff] [blame] | 103 | rcu_read_lock(); |
| 104 | filter = rcu_dereference(sk->sk_filter); |
Stephen Hemminger | 43db6d6 | 2008-04-10 01:43:09 -0700 | [diff] [blame] | 105 | if (filter) { |
Eric Dumazet | 0a14842 | 2011-04-20 09:27:32 +0000 | [diff] [blame] | 106 | unsigned int pkt_len = SK_RUN_FILTER(filter, skb); |
Eric Dumazet | 0d7da9d | 2010-10-25 03:47:05 +0000 | [diff] [blame] | 107 | |
Stephen Hemminger | 43db6d6 | 2008-04-10 01:43:09 -0700 | [diff] [blame] | 108 | err = pkt_len ? pskb_trim(skb, pkt_len) : -EPERM; |
| 109 | } |
Eric Dumazet | 80f8f10 | 2011-01-18 07:46:52 +0000 | [diff] [blame] | 110 | rcu_read_unlock(); |
Stephen Hemminger | 43db6d6 | 2008-04-10 01:43:09 -0700 | [diff] [blame] | 111 | |
| 112 | return err; |
| 113 | } |
| 114 | EXPORT_SYMBOL(sk_filter); |
| 115 | |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 116 | /* Base function for offset calculation. Needs to go into .text section, |
| 117 | * therefore keeping it non-static as well; will also be used by JITs |
| 118 | * anyway later on, so do not let the compiler omit it. |
| 119 | */ |
| 120 | noinline u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5) |
| 121 | { |
| 122 | return 0; |
| 123 | } |
| 124 | |
Stephen Hemminger | 43db6d6 | 2008-04-10 01:43:09 -0700 | [diff] [blame] | 125 | /** |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 126 | * __sk_run_filter - run a filter on a given context |
| 127 | * @ctx: buffer to run the filter on |
Daniel Borkmann | 01d32f6 | 2014-04-01 19:38:01 +0200 | [diff] [blame] | 128 | * @insn: filter to apply |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 129 | * |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 130 | * Decode and apply filter instructions to the skb->data. Return length to |
Daniel Borkmann | 01d32f6 | 2014-04-01 19:38:01 +0200 | [diff] [blame] | 131 | * 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] | 132 | * array of filter instructions. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 133 | */ |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 134 | 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] | 135 | { |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 136 | u64 stack[MAX_BPF_STACK / sizeof(u64)]; |
| 137 | u64 regs[MAX_BPF_REG], tmp; |
Patrick McHardy | 0b05b2a | 2005-07-05 14:10:21 -0700 | [diff] [blame] | 138 | void *ptr; |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 139 | int off; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 140 | |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 141 | #define K insn->imm |
| 142 | #define A regs[insn->a_reg] |
| 143 | #define X regs[insn->x_reg] |
| 144 | #define R0 regs[0] |
YOSHIFUJI Hideaki | 4ec93ed | 2007-02-09 23:24:36 +0900 | [diff] [blame] | 145 | |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 146 | #define CONT ({insn++; goto select_insn; }) |
| 147 | #define CONT_JMP ({insn++; goto select_insn; }) |
Patrick McHardy | 4738c1d | 2008-04-10 02:02:28 -0700 | [diff] [blame] | 148 | |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 149 | static const void *jumptable[256] = { |
| 150 | [0 ... 255] = &&default_label, |
| 151 | /* Now overwrite non-defaults ... */ |
| 152 | #define DL(A, B, C) [A|B|C] = &&A##_##B##_##C |
| 153 | DL(BPF_ALU, BPF_ADD, BPF_X), |
| 154 | DL(BPF_ALU, BPF_ADD, BPF_K), |
| 155 | DL(BPF_ALU, BPF_SUB, BPF_X), |
| 156 | DL(BPF_ALU, BPF_SUB, BPF_K), |
| 157 | DL(BPF_ALU, BPF_AND, BPF_X), |
| 158 | DL(BPF_ALU, BPF_AND, BPF_K), |
| 159 | DL(BPF_ALU, BPF_OR, BPF_X), |
| 160 | DL(BPF_ALU, BPF_OR, BPF_K), |
| 161 | DL(BPF_ALU, BPF_LSH, BPF_X), |
| 162 | DL(BPF_ALU, BPF_LSH, BPF_K), |
| 163 | DL(BPF_ALU, BPF_RSH, BPF_X), |
| 164 | DL(BPF_ALU, BPF_RSH, BPF_K), |
| 165 | DL(BPF_ALU, BPF_XOR, BPF_X), |
| 166 | DL(BPF_ALU, BPF_XOR, BPF_K), |
| 167 | DL(BPF_ALU, BPF_MUL, BPF_X), |
| 168 | DL(BPF_ALU, BPF_MUL, BPF_K), |
| 169 | DL(BPF_ALU, BPF_MOV, BPF_X), |
| 170 | DL(BPF_ALU, BPF_MOV, BPF_K), |
| 171 | DL(BPF_ALU, BPF_DIV, BPF_X), |
| 172 | DL(BPF_ALU, BPF_DIV, BPF_K), |
| 173 | DL(BPF_ALU, BPF_MOD, BPF_X), |
| 174 | DL(BPF_ALU, BPF_MOD, BPF_K), |
| 175 | DL(BPF_ALU, BPF_NEG, 0), |
| 176 | DL(BPF_ALU, BPF_END, BPF_TO_BE), |
| 177 | DL(BPF_ALU, BPF_END, BPF_TO_LE), |
| 178 | DL(BPF_ALU64, BPF_ADD, BPF_X), |
| 179 | DL(BPF_ALU64, BPF_ADD, BPF_K), |
| 180 | DL(BPF_ALU64, BPF_SUB, BPF_X), |
| 181 | DL(BPF_ALU64, BPF_SUB, BPF_K), |
| 182 | DL(BPF_ALU64, BPF_AND, BPF_X), |
| 183 | DL(BPF_ALU64, BPF_AND, BPF_K), |
| 184 | DL(BPF_ALU64, BPF_OR, BPF_X), |
| 185 | DL(BPF_ALU64, BPF_OR, BPF_K), |
| 186 | DL(BPF_ALU64, BPF_LSH, BPF_X), |
| 187 | DL(BPF_ALU64, BPF_LSH, BPF_K), |
| 188 | DL(BPF_ALU64, BPF_RSH, BPF_X), |
| 189 | DL(BPF_ALU64, BPF_RSH, BPF_K), |
| 190 | DL(BPF_ALU64, BPF_XOR, BPF_X), |
| 191 | DL(BPF_ALU64, BPF_XOR, BPF_K), |
| 192 | DL(BPF_ALU64, BPF_MUL, BPF_X), |
| 193 | DL(BPF_ALU64, BPF_MUL, BPF_K), |
| 194 | DL(BPF_ALU64, BPF_MOV, BPF_X), |
| 195 | DL(BPF_ALU64, BPF_MOV, BPF_K), |
| 196 | DL(BPF_ALU64, BPF_ARSH, BPF_X), |
| 197 | DL(BPF_ALU64, BPF_ARSH, BPF_K), |
| 198 | DL(BPF_ALU64, BPF_DIV, BPF_X), |
| 199 | DL(BPF_ALU64, BPF_DIV, BPF_K), |
| 200 | DL(BPF_ALU64, BPF_MOD, BPF_X), |
| 201 | DL(BPF_ALU64, BPF_MOD, BPF_K), |
| 202 | DL(BPF_ALU64, BPF_NEG, 0), |
| 203 | DL(BPF_JMP, BPF_CALL, 0), |
| 204 | DL(BPF_JMP, BPF_JA, 0), |
| 205 | DL(BPF_JMP, BPF_JEQ, BPF_X), |
| 206 | DL(BPF_JMP, BPF_JEQ, BPF_K), |
| 207 | DL(BPF_JMP, BPF_JNE, BPF_X), |
| 208 | DL(BPF_JMP, BPF_JNE, BPF_K), |
| 209 | DL(BPF_JMP, BPF_JGT, BPF_X), |
| 210 | DL(BPF_JMP, BPF_JGT, BPF_K), |
| 211 | DL(BPF_JMP, BPF_JGE, BPF_X), |
| 212 | DL(BPF_JMP, BPF_JGE, BPF_K), |
| 213 | DL(BPF_JMP, BPF_JSGT, BPF_X), |
| 214 | DL(BPF_JMP, BPF_JSGT, BPF_K), |
| 215 | DL(BPF_JMP, BPF_JSGE, BPF_X), |
| 216 | DL(BPF_JMP, BPF_JSGE, BPF_K), |
| 217 | DL(BPF_JMP, BPF_JSET, BPF_X), |
| 218 | DL(BPF_JMP, BPF_JSET, BPF_K), |
| 219 | DL(BPF_JMP, BPF_EXIT, 0), |
| 220 | DL(BPF_STX, BPF_MEM, BPF_B), |
| 221 | DL(BPF_STX, BPF_MEM, BPF_H), |
| 222 | DL(BPF_STX, BPF_MEM, BPF_W), |
| 223 | DL(BPF_STX, BPF_MEM, BPF_DW), |
| 224 | DL(BPF_STX, BPF_XADD, BPF_W), |
| 225 | DL(BPF_STX, BPF_XADD, BPF_DW), |
| 226 | DL(BPF_ST, BPF_MEM, BPF_B), |
| 227 | DL(BPF_ST, BPF_MEM, BPF_H), |
| 228 | DL(BPF_ST, BPF_MEM, BPF_W), |
| 229 | DL(BPF_ST, BPF_MEM, BPF_DW), |
| 230 | DL(BPF_LDX, BPF_MEM, BPF_B), |
| 231 | DL(BPF_LDX, BPF_MEM, BPF_H), |
| 232 | DL(BPF_LDX, BPF_MEM, BPF_W), |
| 233 | DL(BPF_LDX, BPF_MEM, BPF_DW), |
| 234 | DL(BPF_LD, BPF_ABS, BPF_W), |
| 235 | DL(BPF_LD, BPF_ABS, BPF_H), |
| 236 | DL(BPF_LD, BPF_ABS, BPF_B), |
| 237 | DL(BPF_LD, BPF_IND, BPF_W), |
| 238 | DL(BPF_LD, BPF_IND, BPF_H), |
| 239 | DL(BPF_LD, BPF_IND, BPF_B), |
| 240 | #undef DL |
| 241 | }; |
Patrick McHardy | 4738c1d | 2008-04-10 02:02:28 -0700 | [diff] [blame] | 242 | |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 243 | regs[FP_REG] = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; |
| 244 | regs[ARG1_REG] = (u64) (unsigned long) ctx; |
| 245 | |
| 246 | select_insn: |
| 247 | goto *jumptable[insn->code]; |
| 248 | |
| 249 | /* ALU */ |
| 250 | #define ALU(OPCODE, OP) \ |
| 251 | BPF_ALU64_##OPCODE##_BPF_X: \ |
| 252 | A = A OP X; \ |
| 253 | CONT; \ |
| 254 | BPF_ALU_##OPCODE##_BPF_X: \ |
| 255 | A = (u32) A OP (u32) X; \ |
| 256 | CONT; \ |
| 257 | BPF_ALU64_##OPCODE##_BPF_K: \ |
| 258 | A = A OP K; \ |
| 259 | CONT; \ |
| 260 | BPF_ALU_##OPCODE##_BPF_K: \ |
| 261 | A = (u32) A OP (u32) K; \ |
| 262 | CONT; |
| 263 | |
| 264 | ALU(BPF_ADD, +) |
| 265 | ALU(BPF_SUB, -) |
| 266 | ALU(BPF_AND, &) |
| 267 | ALU(BPF_OR, |) |
| 268 | ALU(BPF_LSH, <<) |
| 269 | ALU(BPF_RSH, >>) |
| 270 | ALU(BPF_XOR, ^) |
| 271 | ALU(BPF_MUL, *) |
| 272 | #undef ALU |
| 273 | BPF_ALU_BPF_NEG_0: |
| 274 | A = (u32) -A; |
| 275 | CONT; |
| 276 | BPF_ALU64_BPF_NEG_0: |
| 277 | A = -A; |
| 278 | CONT; |
| 279 | BPF_ALU_BPF_MOV_BPF_X: |
| 280 | A = (u32) X; |
| 281 | CONT; |
| 282 | BPF_ALU_BPF_MOV_BPF_K: |
| 283 | A = (u32) K; |
| 284 | CONT; |
| 285 | BPF_ALU64_BPF_MOV_BPF_X: |
| 286 | A = X; |
| 287 | CONT; |
| 288 | BPF_ALU64_BPF_MOV_BPF_K: |
| 289 | A = K; |
| 290 | CONT; |
| 291 | BPF_ALU64_BPF_ARSH_BPF_X: |
| 292 | (*(s64 *) &A) >>= X; |
| 293 | CONT; |
| 294 | BPF_ALU64_BPF_ARSH_BPF_K: |
| 295 | (*(s64 *) &A) >>= K; |
| 296 | CONT; |
| 297 | BPF_ALU64_BPF_MOD_BPF_X: |
Daniel Borkmann | 5f9fde5 | 2014-04-05 01:04:03 +0200 | [diff] [blame] | 298 | if (unlikely(X == 0)) |
| 299 | return 0; |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 300 | tmp = A; |
Daniel Borkmann | 5f9fde5 | 2014-04-05 01:04:03 +0200 | [diff] [blame] | 301 | A = do_div(tmp, X); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 302 | CONT; |
| 303 | BPF_ALU_BPF_MOD_BPF_X: |
Daniel Borkmann | 5f9fde5 | 2014-04-05 01:04:03 +0200 | [diff] [blame] | 304 | if (unlikely(X == 0)) |
| 305 | return 0; |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 306 | tmp = (u32) A; |
Daniel Borkmann | 5f9fde5 | 2014-04-05 01:04:03 +0200 | [diff] [blame] | 307 | A = do_div(tmp, (u32) X); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 308 | CONT; |
| 309 | BPF_ALU64_BPF_MOD_BPF_K: |
| 310 | tmp = A; |
Daniel Borkmann | 5f9fde5 | 2014-04-05 01:04:03 +0200 | [diff] [blame] | 311 | A = do_div(tmp, K); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 312 | CONT; |
| 313 | BPF_ALU_BPF_MOD_BPF_K: |
| 314 | tmp = (u32) A; |
Daniel Borkmann | 5f9fde5 | 2014-04-05 01:04:03 +0200 | [diff] [blame] | 315 | A = do_div(tmp, (u32) K); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 316 | CONT; |
| 317 | BPF_ALU64_BPF_DIV_BPF_X: |
Daniel Borkmann | 5f9fde5 | 2014-04-05 01:04:03 +0200 | [diff] [blame] | 318 | if (unlikely(X == 0)) |
| 319 | return 0; |
| 320 | do_div(A, X); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 321 | CONT; |
| 322 | BPF_ALU_BPF_DIV_BPF_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 = (u32) A; |
Daniel Borkmann | 5f9fde5 | 2014-04-05 01:04:03 +0200 | [diff] [blame] | 326 | do_div(tmp, (u32) X); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 327 | A = (u32) tmp; |
| 328 | CONT; |
| 329 | BPF_ALU64_BPF_DIV_BPF_K: |
Daniel Borkmann | 5f9fde5 | 2014-04-05 01:04:03 +0200 | [diff] [blame] | 330 | do_div(A, K); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 331 | CONT; |
| 332 | BPF_ALU_BPF_DIV_BPF_K: |
| 333 | tmp = (u32) A; |
Daniel Borkmann | 5f9fde5 | 2014-04-05 01:04:03 +0200 | [diff] [blame] | 334 | do_div(tmp, (u32) K); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 335 | A = (u32) tmp; |
| 336 | CONT; |
| 337 | BPF_ALU_BPF_END_BPF_TO_BE: |
| 338 | switch (K) { |
| 339 | case 16: |
| 340 | A = (__force u16) cpu_to_be16(A); |
| 341 | break; |
| 342 | case 32: |
| 343 | A = (__force u32) cpu_to_be32(A); |
| 344 | break; |
| 345 | case 64: |
| 346 | A = (__force u64) cpu_to_be64(A); |
| 347 | break; |
Patrick McHardy | 4738c1d | 2008-04-10 02:02:28 -0700 | [diff] [blame] | 348 | } |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 349 | CONT; |
| 350 | BPF_ALU_BPF_END_BPF_TO_LE: |
| 351 | switch (K) { |
| 352 | case 16: |
| 353 | A = (__force u16) cpu_to_le16(A); |
| 354 | break; |
| 355 | case 32: |
| 356 | A = (__force u32) cpu_to_le32(A); |
| 357 | break; |
| 358 | case 64: |
| 359 | A = (__force u64) cpu_to_le64(A); |
| 360 | break; |
Pablo Neira Ayuso | d214c75 | 2008-11-20 00:49:27 -0800 | [diff] [blame] | 361 | } |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 362 | CONT; |
| 363 | |
| 364 | /* CALL */ |
| 365 | BPF_JMP_BPF_CALL_0: |
| 366 | /* Function call scratches R1-R5 registers, preserves R6-R9, |
| 367 | * and stores return value into R0. |
| 368 | */ |
| 369 | R0 = (__bpf_call_base + insn->imm)(regs[1], regs[2], regs[3], |
| 370 | regs[4], regs[5]); |
| 371 | CONT; |
| 372 | |
| 373 | /* JMP */ |
| 374 | BPF_JMP_BPF_JA_0: |
| 375 | insn += insn->off; |
| 376 | CONT; |
| 377 | BPF_JMP_BPF_JEQ_BPF_X: |
| 378 | if (A == X) { |
| 379 | insn += insn->off; |
| 380 | CONT_JMP; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 381 | } |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 382 | CONT; |
| 383 | BPF_JMP_BPF_JEQ_BPF_K: |
| 384 | if (A == K) { |
| 385 | insn += insn->off; |
| 386 | CONT_JMP; |
| 387 | } |
| 388 | CONT; |
| 389 | BPF_JMP_BPF_JNE_BPF_X: |
| 390 | if (A != X) { |
| 391 | insn += insn->off; |
| 392 | CONT_JMP; |
| 393 | } |
| 394 | CONT; |
| 395 | BPF_JMP_BPF_JNE_BPF_K: |
| 396 | if (A != K) { |
| 397 | insn += insn->off; |
| 398 | CONT_JMP; |
| 399 | } |
| 400 | CONT; |
| 401 | BPF_JMP_BPF_JGT_BPF_X: |
| 402 | if (A > X) { |
| 403 | insn += insn->off; |
| 404 | CONT_JMP; |
| 405 | } |
| 406 | CONT; |
| 407 | BPF_JMP_BPF_JGT_BPF_K: |
| 408 | if (A > K) { |
| 409 | insn += insn->off; |
| 410 | CONT_JMP; |
| 411 | } |
| 412 | CONT; |
| 413 | BPF_JMP_BPF_JGE_BPF_X: |
| 414 | if (A >= X) { |
| 415 | insn += insn->off; |
| 416 | CONT_JMP; |
| 417 | } |
| 418 | CONT; |
| 419 | BPF_JMP_BPF_JGE_BPF_K: |
| 420 | if (A >= K) { |
| 421 | insn += insn->off; |
| 422 | CONT_JMP; |
| 423 | } |
| 424 | CONT; |
| 425 | BPF_JMP_BPF_JSGT_BPF_X: |
| 426 | if (((s64)A) > ((s64)X)) { |
| 427 | insn += insn->off; |
| 428 | CONT_JMP; |
| 429 | } |
| 430 | CONT; |
| 431 | BPF_JMP_BPF_JSGT_BPF_K: |
| 432 | if (((s64)A) > ((s64)K)) { |
| 433 | insn += insn->off; |
| 434 | CONT_JMP; |
| 435 | } |
| 436 | CONT; |
| 437 | BPF_JMP_BPF_JSGE_BPF_X: |
| 438 | if (((s64)A) >= ((s64)X)) { |
| 439 | insn += insn->off; |
| 440 | CONT_JMP; |
| 441 | } |
| 442 | CONT; |
| 443 | BPF_JMP_BPF_JSGE_BPF_K: |
| 444 | if (((s64)A) >= ((s64)K)) { |
| 445 | insn += insn->off; |
| 446 | CONT_JMP; |
| 447 | } |
| 448 | CONT; |
| 449 | BPF_JMP_BPF_JSET_BPF_X: |
| 450 | if (A & X) { |
| 451 | insn += insn->off; |
| 452 | CONT_JMP; |
| 453 | } |
| 454 | CONT; |
| 455 | BPF_JMP_BPF_JSET_BPF_K: |
| 456 | if (A & K) { |
| 457 | insn += insn->off; |
| 458 | CONT_JMP; |
| 459 | } |
| 460 | CONT; |
| 461 | BPF_JMP_BPF_EXIT_0: |
| 462 | return R0; |
| 463 | |
| 464 | /* STX and ST and LDX*/ |
| 465 | #define LDST(SIZEOP, SIZE) \ |
| 466 | BPF_STX_BPF_MEM_##SIZEOP: \ |
| 467 | *(SIZE *)(unsigned long) (A + insn->off) = X; \ |
| 468 | CONT; \ |
| 469 | BPF_ST_BPF_MEM_##SIZEOP: \ |
| 470 | *(SIZE *)(unsigned long) (A + insn->off) = K; \ |
| 471 | CONT; \ |
| 472 | BPF_LDX_BPF_MEM_##SIZEOP: \ |
| 473 | A = *(SIZE *)(unsigned long) (X + insn->off); \ |
| 474 | CONT; |
| 475 | |
| 476 | LDST(BPF_B, u8) |
| 477 | LDST(BPF_H, u16) |
| 478 | LDST(BPF_W, u32) |
| 479 | LDST(BPF_DW, u64) |
| 480 | #undef LDST |
| 481 | BPF_STX_BPF_XADD_BPF_W: /* lock xadd *(u32 *)(A + insn->off) += X */ |
| 482 | atomic_add((u32) X, (atomic_t *)(unsigned long) |
| 483 | (A + insn->off)); |
| 484 | CONT; |
| 485 | BPF_STX_BPF_XADD_BPF_DW: /* lock xadd *(u64 *)(A + insn->off) += X */ |
| 486 | atomic64_add((u64) X, (atomic64_t *)(unsigned long) |
| 487 | (A + insn->off)); |
| 488 | CONT; |
| 489 | BPF_LD_BPF_ABS_BPF_W: /* R0 = ntohl(*(u32 *) (skb->data + K)) */ |
| 490 | off = K; |
| 491 | load_word: |
| 492 | /* BPF_LD + BPD_ABS and BPF_LD + BPF_IND insns are only |
| 493 | * appearing in the programs where ctx == skb. All programs |
| 494 | * keep 'ctx' in regs[CTX_REG] == R6, sk_convert_filter() |
| 495 | * saves it in R6, internal BPF verifier will check that |
| 496 | * R6 == ctx. |
| 497 | * |
| 498 | * BPF_ABS and BPF_IND are wrappers of function calls, so |
| 499 | * they scratch R1-R5 registers, preserve R6-R9, and store |
| 500 | * return value into R0. |
| 501 | * |
| 502 | * Implicit input: |
| 503 | * ctx |
| 504 | * |
| 505 | * Explicit input: |
| 506 | * X == any register |
| 507 | * K == 32-bit immediate |
| 508 | * |
| 509 | * Output: |
| 510 | * R0 - 8/16/32-bit skb data converted to cpu endianness |
| 511 | */ |
| 512 | ptr = load_pointer((struct sk_buff *) ctx, off, 4, &tmp); |
| 513 | if (likely(ptr != NULL)) { |
| 514 | R0 = get_unaligned_be32(ptr); |
| 515 | CONT; |
| 516 | } |
| 517 | return 0; |
| 518 | BPF_LD_BPF_ABS_BPF_H: /* R0 = ntohs(*(u16 *) (skb->data + K)) */ |
| 519 | off = K; |
| 520 | load_half: |
| 521 | ptr = load_pointer((struct sk_buff *) ctx, off, 2, &tmp); |
| 522 | if (likely(ptr != NULL)) { |
| 523 | R0 = get_unaligned_be16(ptr); |
| 524 | CONT; |
| 525 | } |
| 526 | return 0; |
| 527 | BPF_LD_BPF_ABS_BPF_B: /* R0 = *(u8 *) (ctx + K) */ |
| 528 | off = K; |
| 529 | load_byte: |
| 530 | ptr = load_pointer((struct sk_buff *) ctx, off, 1, &tmp); |
| 531 | if (likely(ptr != NULL)) { |
| 532 | R0 = *(u8 *)ptr; |
| 533 | CONT; |
| 534 | } |
| 535 | return 0; |
| 536 | BPF_LD_BPF_IND_BPF_W: /* R0 = ntohl(*(u32 *) (skb->data + X + K)) */ |
| 537 | off = K + X; |
| 538 | goto load_word; |
| 539 | BPF_LD_BPF_IND_BPF_H: /* R0 = ntohs(*(u16 *) (skb->data + X + K)) */ |
| 540 | off = K + X; |
| 541 | goto load_half; |
| 542 | BPF_LD_BPF_IND_BPF_B: /* R0 = *(u8 *) (skb->data + X + K) */ |
| 543 | off = K + X; |
| 544 | goto load_byte; |
| 545 | |
| 546 | default_label: |
| 547 | /* If we ever reach this, we have a bug somewhere. */ |
| 548 | WARN_RATELIMIT(1, "unknown opcode %02x\n", insn->code); |
| 549 | return 0; |
| 550 | #undef CONT_JMP |
| 551 | #undef CONT |
| 552 | |
| 553 | #undef R0 |
| 554 | #undef X |
| 555 | #undef A |
| 556 | #undef K |
| 557 | } |
| 558 | |
| 559 | u32 sk_run_filter_int_seccomp(const struct seccomp_data *ctx, |
| 560 | const struct sock_filter_int *insni) |
| 561 | __attribute__ ((alias ("__sk_run_filter"))); |
| 562 | |
| 563 | u32 sk_run_filter_int_skb(const struct sk_buff *ctx, |
| 564 | const struct sock_filter_int *insni) |
| 565 | __attribute__ ((alias ("__sk_run_filter"))); |
| 566 | EXPORT_SYMBOL_GPL(sk_run_filter_int_skb); |
| 567 | |
| 568 | /* Helper to find the offset of pkt_type in sk_buff structure. We want |
| 569 | * to make sure its still a 3bit field starting at a byte boundary; |
| 570 | * taken from arch/x86/net/bpf_jit_comp.c. |
| 571 | */ |
| 572 | #define PKT_TYPE_MAX 7 |
| 573 | static unsigned int pkt_type_offset(void) |
| 574 | { |
| 575 | struct sk_buff skb_probe = { .pkt_type = ~0, }; |
| 576 | u8 *ct = (u8 *) &skb_probe; |
| 577 | unsigned int off; |
| 578 | |
| 579 | for (off = 0; off < sizeof(struct sk_buff); off++) { |
| 580 | if (ct[off] == PKT_TYPE_MAX) |
| 581 | return off; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 582 | } |
| 583 | |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 584 | pr_err_once("Please fix %s, as pkt_type couldn't be found!\n", __func__); |
| 585 | return -1; |
| 586 | } |
| 587 | |
| 588 | static u64 __skb_get_pay_offset(u64 ctx, u64 A, u64 X, u64 r4, u64 r5) |
| 589 | { |
| 590 | struct sk_buff *skb = (struct sk_buff *)(long) ctx; |
| 591 | |
| 592 | return __skb_get_poff(skb); |
| 593 | } |
| 594 | |
| 595 | static u64 __skb_get_nlattr(u64 ctx, u64 A, u64 X, u64 r4, u64 r5) |
| 596 | { |
| 597 | struct sk_buff *skb = (struct sk_buff *)(long) ctx; |
| 598 | struct nlattr *nla; |
| 599 | |
| 600 | if (skb_is_nonlinear(skb)) |
| 601 | return 0; |
| 602 | |
Mathias Krause | 05ab8f2 | 2014-04-13 18:23:33 +0200 | [diff] [blame] | 603 | if (skb->len < sizeof(struct nlattr)) |
| 604 | return 0; |
| 605 | |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 606 | if (A > skb->len - sizeof(struct nlattr)) |
| 607 | return 0; |
| 608 | |
| 609 | nla = nla_find((struct nlattr *) &skb->data[A], skb->len - A, X); |
| 610 | if (nla) |
| 611 | return (void *) nla - (void *) skb->data; |
| 612 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 613 | return 0; |
| 614 | } |
| 615 | |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 616 | static u64 __skb_get_nlattr_nest(u64 ctx, u64 A, u64 X, u64 r4, u64 r5) |
| 617 | { |
| 618 | struct sk_buff *skb = (struct sk_buff *)(long) ctx; |
| 619 | struct nlattr *nla; |
| 620 | |
| 621 | if (skb_is_nonlinear(skb)) |
| 622 | return 0; |
| 623 | |
Mathias Krause | 05ab8f2 | 2014-04-13 18:23:33 +0200 | [diff] [blame] | 624 | if (skb->len < sizeof(struct nlattr)) |
| 625 | return 0; |
| 626 | |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 627 | if (A > skb->len - sizeof(struct nlattr)) |
| 628 | return 0; |
| 629 | |
| 630 | nla = (struct nlattr *) &skb->data[A]; |
Mathias Krause | 05ab8f2 | 2014-04-13 18:23:33 +0200 | [diff] [blame] | 631 | if (nla->nla_len > skb->len - A) |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 632 | return 0; |
| 633 | |
| 634 | nla = nla_find_nested(nla, X); |
| 635 | if (nla) |
| 636 | return (void *) nla - (void *) skb->data; |
| 637 | |
| 638 | return 0; |
| 639 | } |
| 640 | |
| 641 | static u64 __get_raw_cpu_id(u64 ctx, u64 A, u64 X, u64 r4, u64 r5) |
| 642 | { |
| 643 | return raw_smp_processor_id(); |
| 644 | } |
| 645 | |
Chema Gonzalez | 4cd3675 | 2014-04-21 09:21:24 -0700 | [diff] [blame] | 646 | /* note that this only generates 32-bit random numbers */ |
| 647 | static u64 __get_random_u32(u64 ctx, u64 A, u64 X, u64 r4, u64 r5) |
| 648 | { |
| 649 | return (u64)prandom_u32(); |
| 650 | } |
| 651 | |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 652 | /* Register mappings for user programs. */ |
| 653 | #define A_REG 0 |
| 654 | #define X_REG 7 |
| 655 | #define TMP_REG 8 |
| 656 | #define ARG2_REG 2 |
| 657 | #define ARG3_REG 3 |
| 658 | |
| 659 | static bool convert_bpf_extensions(struct sock_filter *fp, |
| 660 | struct sock_filter_int **insnp) |
| 661 | { |
| 662 | struct sock_filter_int *insn = *insnp; |
| 663 | |
| 664 | switch (fp->k) { |
| 665 | case SKF_AD_OFF + SKF_AD_PROTOCOL: |
| 666 | BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, protocol) != 2); |
| 667 | |
| 668 | insn->code = BPF_LDX | BPF_MEM | BPF_H; |
| 669 | insn->a_reg = A_REG; |
| 670 | insn->x_reg = CTX_REG; |
| 671 | insn->off = offsetof(struct sk_buff, protocol); |
| 672 | insn++; |
| 673 | |
| 674 | /* A = ntohs(A) [emitting a nop or swap16] */ |
| 675 | insn->code = BPF_ALU | BPF_END | BPF_FROM_BE; |
| 676 | insn->a_reg = A_REG; |
| 677 | insn->imm = 16; |
| 678 | break; |
| 679 | |
| 680 | case SKF_AD_OFF + SKF_AD_PKTTYPE: |
| 681 | insn->code = BPF_LDX | BPF_MEM | BPF_B; |
| 682 | insn->a_reg = A_REG; |
| 683 | insn->x_reg = CTX_REG; |
| 684 | insn->off = pkt_type_offset(); |
| 685 | if (insn->off < 0) |
| 686 | return false; |
| 687 | insn++; |
| 688 | |
| 689 | insn->code = BPF_ALU | BPF_AND | BPF_K; |
| 690 | insn->a_reg = A_REG; |
| 691 | insn->imm = PKT_TYPE_MAX; |
| 692 | break; |
| 693 | |
| 694 | case SKF_AD_OFF + SKF_AD_IFINDEX: |
| 695 | case SKF_AD_OFF + SKF_AD_HATYPE: |
| 696 | if (FIELD_SIZEOF(struct sk_buff, dev) == 8) |
| 697 | insn->code = BPF_LDX | BPF_MEM | BPF_DW; |
| 698 | else |
| 699 | insn->code = BPF_LDX | BPF_MEM | BPF_W; |
| 700 | insn->a_reg = TMP_REG; |
| 701 | insn->x_reg = CTX_REG; |
| 702 | insn->off = offsetof(struct sk_buff, dev); |
| 703 | insn++; |
| 704 | |
| 705 | insn->code = BPF_JMP | BPF_JNE | BPF_K; |
| 706 | insn->a_reg = TMP_REG; |
| 707 | insn->imm = 0; |
| 708 | insn->off = 1; |
| 709 | insn++; |
| 710 | |
| 711 | insn->code = BPF_JMP | BPF_EXIT; |
| 712 | insn++; |
| 713 | |
| 714 | BUILD_BUG_ON(FIELD_SIZEOF(struct net_device, ifindex) != 4); |
| 715 | BUILD_BUG_ON(FIELD_SIZEOF(struct net_device, type) != 2); |
| 716 | |
| 717 | insn->a_reg = A_REG; |
| 718 | insn->x_reg = TMP_REG; |
| 719 | |
| 720 | if (fp->k == SKF_AD_OFF + SKF_AD_IFINDEX) { |
| 721 | insn->code = BPF_LDX | BPF_MEM | BPF_W; |
| 722 | insn->off = offsetof(struct net_device, ifindex); |
| 723 | } else { |
| 724 | insn->code = BPF_LDX | BPF_MEM | BPF_H; |
| 725 | insn->off = offsetof(struct net_device, type); |
| 726 | } |
| 727 | break; |
| 728 | |
| 729 | case SKF_AD_OFF + SKF_AD_MARK: |
| 730 | BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, mark) != 4); |
| 731 | |
| 732 | insn->code = BPF_LDX | BPF_MEM | BPF_W; |
| 733 | insn->a_reg = A_REG; |
| 734 | insn->x_reg = CTX_REG; |
| 735 | insn->off = offsetof(struct sk_buff, mark); |
| 736 | break; |
| 737 | |
| 738 | case SKF_AD_OFF + SKF_AD_RXHASH: |
| 739 | BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, hash) != 4); |
| 740 | |
| 741 | insn->code = BPF_LDX | BPF_MEM | BPF_W; |
| 742 | insn->a_reg = A_REG; |
| 743 | insn->x_reg = CTX_REG; |
| 744 | insn->off = offsetof(struct sk_buff, hash); |
| 745 | break; |
| 746 | |
| 747 | case SKF_AD_OFF + SKF_AD_QUEUE: |
| 748 | BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, queue_mapping) != 2); |
| 749 | |
| 750 | insn->code = BPF_LDX | BPF_MEM | BPF_H; |
| 751 | insn->a_reg = A_REG; |
| 752 | insn->x_reg = CTX_REG; |
| 753 | insn->off = offsetof(struct sk_buff, queue_mapping); |
| 754 | break; |
| 755 | |
| 756 | case SKF_AD_OFF + SKF_AD_VLAN_TAG: |
| 757 | case SKF_AD_OFF + SKF_AD_VLAN_TAG_PRESENT: |
| 758 | BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, vlan_tci) != 2); |
| 759 | |
| 760 | insn->code = BPF_LDX | BPF_MEM | BPF_H; |
| 761 | insn->a_reg = A_REG; |
| 762 | insn->x_reg = CTX_REG; |
| 763 | insn->off = offsetof(struct sk_buff, vlan_tci); |
| 764 | insn++; |
| 765 | |
| 766 | BUILD_BUG_ON(VLAN_TAG_PRESENT != 0x1000); |
| 767 | |
| 768 | if (fp->k == SKF_AD_OFF + SKF_AD_VLAN_TAG) { |
| 769 | insn->code = BPF_ALU | BPF_AND | BPF_K; |
| 770 | insn->a_reg = A_REG; |
| 771 | insn->imm = ~VLAN_TAG_PRESENT; |
| 772 | } else { |
| 773 | insn->code = BPF_ALU | BPF_RSH | BPF_K; |
| 774 | insn->a_reg = A_REG; |
| 775 | insn->imm = 12; |
| 776 | insn++; |
| 777 | |
| 778 | insn->code = BPF_ALU | BPF_AND | BPF_K; |
| 779 | insn->a_reg = A_REG; |
| 780 | insn->imm = 1; |
| 781 | } |
| 782 | break; |
| 783 | |
| 784 | case SKF_AD_OFF + SKF_AD_PAY_OFFSET: |
| 785 | case SKF_AD_OFF + SKF_AD_NLATTR: |
| 786 | case SKF_AD_OFF + SKF_AD_NLATTR_NEST: |
| 787 | case SKF_AD_OFF + SKF_AD_CPU: |
Chema Gonzalez | 4cd3675 | 2014-04-21 09:21:24 -0700 | [diff] [blame] | 788 | case SKF_AD_OFF + SKF_AD_RANDOM: |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 789 | /* arg1 = ctx */ |
| 790 | insn->code = BPF_ALU64 | BPF_MOV | BPF_X; |
| 791 | insn->a_reg = ARG1_REG; |
| 792 | insn->x_reg = CTX_REG; |
| 793 | insn++; |
| 794 | |
| 795 | /* arg2 = A */ |
| 796 | insn->code = BPF_ALU64 | BPF_MOV | BPF_X; |
| 797 | insn->a_reg = ARG2_REG; |
| 798 | insn->x_reg = A_REG; |
| 799 | insn++; |
| 800 | |
| 801 | /* arg3 = X */ |
| 802 | insn->code = BPF_ALU64 | BPF_MOV | BPF_X; |
| 803 | insn->a_reg = ARG3_REG; |
| 804 | insn->x_reg = X_REG; |
| 805 | insn++; |
| 806 | |
| 807 | /* Emit call(ctx, arg2=A, arg3=X) */ |
| 808 | insn->code = BPF_JMP | BPF_CALL; |
| 809 | switch (fp->k) { |
| 810 | case SKF_AD_OFF + SKF_AD_PAY_OFFSET: |
| 811 | insn->imm = __skb_get_pay_offset - __bpf_call_base; |
| 812 | break; |
| 813 | case SKF_AD_OFF + SKF_AD_NLATTR: |
| 814 | insn->imm = __skb_get_nlattr - __bpf_call_base; |
| 815 | break; |
| 816 | case SKF_AD_OFF + SKF_AD_NLATTR_NEST: |
| 817 | insn->imm = __skb_get_nlattr_nest - __bpf_call_base; |
| 818 | break; |
| 819 | case SKF_AD_OFF + SKF_AD_CPU: |
| 820 | insn->imm = __get_raw_cpu_id - __bpf_call_base; |
| 821 | break; |
Chema Gonzalez | 4cd3675 | 2014-04-21 09:21:24 -0700 | [diff] [blame] | 822 | case SKF_AD_OFF + SKF_AD_RANDOM: |
| 823 | insn->imm = __get_random_u32 - __bpf_call_base; |
| 824 | break; |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 825 | } |
| 826 | break; |
| 827 | |
| 828 | case SKF_AD_OFF + SKF_AD_ALU_XOR_X: |
| 829 | insn->code = BPF_ALU | BPF_XOR | BPF_X; |
| 830 | insn->a_reg = A_REG; |
| 831 | insn->x_reg = X_REG; |
| 832 | break; |
| 833 | |
| 834 | default: |
| 835 | /* This is just a dummy call to avoid letting the compiler |
| 836 | * evict __bpf_call_base() as an optimization. Placed here |
| 837 | * where no-one bothers. |
| 838 | */ |
| 839 | BUG_ON(__bpf_call_base(0, 0, 0, 0, 0) != 0); |
| 840 | return false; |
| 841 | } |
| 842 | |
| 843 | *insnp = insn; |
| 844 | return true; |
| 845 | } |
| 846 | |
| 847 | /** |
| 848 | * sk_convert_filter - convert filter program |
| 849 | * @prog: the user passed filter program |
| 850 | * @len: the length of the user passed filter program |
| 851 | * @new_prog: buffer where converted program will be stored |
| 852 | * @new_len: pointer to store length of converted program |
| 853 | * |
| 854 | * Remap 'sock_filter' style BPF instruction set to 'sock_filter_ext' style. |
| 855 | * Conversion workflow: |
| 856 | * |
| 857 | * 1) First pass for calculating the new program length: |
| 858 | * sk_convert_filter(old_prog, old_len, NULL, &new_len) |
| 859 | * |
| 860 | * 2) 2nd pass to remap in two passes: 1st pass finds new |
| 861 | * jump offsets, 2nd pass remapping: |
| 862 | * new_prog = kmalloc(sizeof(struct sock_filter_int) * new_len); |
| 863 | * sk_convert_filter(old_prog, old_len, new_prog, &new_len); |
| 864 | * |
| 865 | * User BPF's register A is mapped to our BPF register 6, user BPF |
| 866 | * register X is mapped to BPF register 7; frame pointer is always |
| 867 | * register 10; Context 'void *ctx' is stored in register 1, that is, |
| 868 | * for socket filters: ctx == 'struct sk_buff *', for seccomp: |
| 869 | * ctx == 'struct seccomp_data *'. |
| 870 | */ |
| 871 | int sk_convert_filter(struct sock_filter *prog, int len, |
| 872 | struct sock_filter_int *new_prog, int *new_len) |
| 873 | { |
| 874 | int new_flen = 0, pass = 0, target, i; |
| 875 | struct sock_filter_int *new_insn; |
| 876 | struct sock_filter *fp; |
| 877 | int *addrs = NULL; |
| 878 | u8 bpf_src; |
| 879 | |
| 880 | BUILD_BUG_ON(BPF_MEMWORDS * sizeof(u32) > MAX_BPF_STACK); |
| 881 | BUILD_BUG_ON(FP_REG + 1 != MAX_BPF_REG); |
| 882 | |
| 883 | if (len <= 0 || len >= BPF_MAXINSNS) |
| 884 | return -EINVAL; |
| 885 | |
| 886 | if (new_prog) { |
| 887 | addrs = kzalloc(len * sizeof(*addrs), GFP_KERNEL); |
| 888 | if (!addrs) |
| 889 | return -ENOMEM; |
| 890 | } |
| 891 | |
| 892 | do_pass: |
| 893 | new_insn = new_prog; |
| 894 | fp = prog; |
| 895 | |
| 896 | if (new_insn) { |
| 897 | new_insn->code = BPF_ALU64 | BPF_MOV | BPF_X; |
| 898 | new_insn->a_reg = CTX_REG; |
| 899 | new_insn->x_reg = ARG1_REG; |
| 900 | } |
| 901 | new_insn++; |
| 902 | |
| 903 | for (i = 0; i < len; fp++, i++) { |
| 904 | struct sock_filter_int tmp_insns[6] = { }; |
| 905 | struct sock_filter_int *insn = tmp_insns; |
| 906 | |
| 907 | if (addrs) |
| 908 | addrs[i] = new_insn - new_prog; |
| 909 | |
| 910 | switch (fp->code) { |
| 911 | /* All arithmetic insns and skb loads map as-is. */ |
| 912 | case BPF_ALU | BPF_ADD | BPF_X: |
| 913 | case BPF_ALU | BPF_ADD | BPF_K: |
| 914 | case BPF_ALU | BPF_SUB | BPF_X: |
| 915 | case BPF_ALU | BPF_SUB | BPF_K: |
| 916 | case BPF_ALU | BPF_AND | BPF_X: |
| 917 | case BPF_ALU | BPF_AND | BPF_K: |
| 918 | case BPF_ALU | BPF_OR | BPF_X: |
| 919 | case BPF_ALU | BPF_OR | BPF_K: |
| 920 | case BPF_ALU | BPF_LSH | BPF_X: |
| 921 | case BPF_ALU | BPF_LSH | BPF_K: |
| 922 | case BPF_ALU | BPF_RSH | BPF_X: |
| 923 | case BPF_ALU | BPF_RSH | BPF_K: |
| 924 | case BPF_ALU | BPF_XOR | BPF_X: |
| 925 | case BPF_ALU | BPF_XOR | BPF_K: |
| 926 | case BPF_ALU | BPF_MUL | BPF_X: |
| 927 | case BPF_ALU | BPF_MUL | BPF_K: |
| 928 | case BPF_ALU | BPF_DIV | BPF_X: |
| 929 | case BPF_ALU | BPF_DIV | BPF_K: |
| 930 | case BPF_ALU | BPF_MOD | BPF_X: |
| 931 | case BPF_ALU | BPF_MOD | BPF_K: |
| 932 | case BPF_ALU | BPF_NEG: |
| 933 | case BPF_LD | BPF_ABS | BPF_W: |
| 934 | case BPF_LD | BPF_ABS | BPF_H: |
| 935 | case BPF_LD | BPF_ABS | BPF_B: |
| 936 | case BPF_LD | BPF_IND | BPF_W: |
| 937 | case BPF_LD | BPF_IND | BPF_H: |
| 938 | case BPF_LD | BPF_IND | BPF_B: |
| 939 | /* Check for overloaded BPF extension and |
| 940 | * directly convert it if found, otherwise |
| 941 | * just move on with mapping. |
| 942 | */ |
| 943 | if (BPF_CLASS(fp->code) == BPF_LD && |
| 944 | BPF_MODE(fp->code) == BPF_ABS && |
| 945 | convert_bpf_extensions(fp, &insn)) |
| 946 | break; |
| 947 | |
| 948 | insn->code = fp->code; |
| 949 | insn->a_reg = A_REG; |
| 950 | insn->x_reg = X_REG; |
| 951 | insn->imm = fp->k; |
| 952 | break; |
| 953 | |
| 954 | /* Jump opcodes map as-is, but offsets need adjustment. */ |
| 955 | case BPF_JMP | BPF_JA: |
| 956 | target = i + fp->k + 1; |
| 957 | insn->code = fp->code; |
| 958 | #define EMIT_JMP \ |
| 959 | do { \ |
| 960 | if (target >= len || target < 0) \ |
| 961 | goto err; \ |
| 962 | insn->off = addrs ? addrs[target] - addrs[i] - 1 : 0; \ |
| 963 | /* Adjust pc relative offset for 2nd or 3rd insn. */ \ |
| 964 | insn->off -= insn - tmp_insns; \ |
| 965 | } while (0) |
| 966 | |
| 967 | EMIT_JMP; |
| 968 | break; |
| 969 | |
| 970 | case BPF_JMP | BPF_JEQ | BPF_K: |
| 971 | case BPF_JMP | BPF_JEQ | BPF_X: |
| 972 | case BPF_JMP | BPF_JSET | BPF_K: |
| 973 | case BPF_JMP | BPF_JSET | BPF_X: |
| 974 | case BPF_JMP | BPF_JGT | BPF_K: |
| 975 | case BPF_JMP | BPF_JGT | BPF_X: |
| 976 | case BPF_JMP | BPF_JGE | BPF_K: |
| 977 | case BPF_JMP | BPF_JGE | BPF_X: |
| 978 | if (BPF_SRC(fp->code) == BPF_K && (int) fp->k < 0) { |
| 979 | /* BPF immediates are signed, zero extend |
| 980 | * immediate into tmp register and use it |
| 981 | * in compare insn. |
| 982 | */ |
| 983 | insn->code = BPF_ALU | BPF_MOV | BPF_K; |
| 984 | insn->a_reg = TMP_REG; |
| 985 | insn->imm = fp->k; |
| 986 | insn++; |
| 987 | |
| 988 | insn->a_reg = A_REG; |
| 989 | insn->x_reg = TMP_REG; |
| 990 | bpf_src = BPF_X; |
| 991 | } else { |
| 992 | insn->a_reg = A_REG; |
| 993 | insn->x_reg = X_REG; |
| 994 | insn->imm = fp->k; |
| 995 | bpf_src = BPF_SRC(fp->code); |
| 996 | } |
| 997 | |
| 998 | /* Common case where 'jump_false' is next insn. */ |
| 999 | if (fp->jf == 0) { |
| 1000 | insn->code = BPF_JMP | BPF_OP(fp->code) | bpf_src; |
| 1001 | target = i + fp->jt + 1; |
| 1002 | EMIT_JMP; |
| 1003 | break; |
| 1004 | } |
| 1005 | |
| 1006 | /* Convert JEQ into JNE when 'jump_true' is next insn. */ |
| 1007 | if (fp->jt == 0 && BPF_OP(fp->code) == BPF_JEQ) { |
| 1008 | insn->code = BPF_JMP | BPF_JNE | bpf_src; |
| 1009 | target = i + fp->jf + 1; |
| 1010 | EMIT_JMP; |
| 1011 | break; |
| 1012 | } |
| 1013 | |
| 1014 | /* Other jumps are mapped into two insns: Jxx and JA. */ |
| 1015 | target = i + fp->jt + 1; |
| 1016 | insn->code = BPF_JMP | BPF_OP(fp->code) | bpf_src; |
| 1017 | EMIT_JMP; |
| 1018 | insn++; |
| 1019 | |
| 1020 | insn->code = BPF_JMP | BPF_JA; |
| 1021 | target = i + fp->jf + 1; |
| 1022 | EMIT_JMP; |
| 1023 | break; |
| 1024 | |
| 1025 | /* ldxb 4 * ([14] & 0xf) is remaped into 6 insns. */ |
| 1026 | case BPF_LDX | BPF_MSH | BPF_B: |
| 1027 | insn->code = BPF_ALU64 | BPF_MOV | BPF_X; |
| 1028 | insn->a_reg = TMP_REG; |
| 1029 | insn->x_reg = A_REG; |
| 1030 | insn++; |
| 1031 | |
| 1032 | insn->code = BPF_LD | BPF_ABS | BPF_B; |
| 1033 | insn->a_reg = A_REG; |
| 1034 | insn->imm = fp->k; |
| 1035 | insn++; |
| 1036 | |
| 1037 | insn->code = BPF_ALU | BPF_AND | BPF_K; |
| 1038 | insn->a_reg = A_REG; |
| 1039 | insn->imm = 0xf; |
| 1040 | insn++; |
| 1041 | |
| 1042 | insn->code = BPF_ALU | BPF_LSH | BPF_K; |
| 1043 | insn->a_reg = A_REG; |
| 1044 | insn->imm = 2; |
| 1045 | insn++; |
| 1046 | |
| 1047 | insn->code = BPF_ALU64 | BPF_MOV | BPF_X; |
| 1048 | insn->a_reg = X_REG; |
| 1049 | insn->x_reg = A_REG; |
| 1050 | insn++; |
| 1051 | |
| 1052 | insn->code = BPF_ALU64 | BPF_MOV | BPF_X; |
| 1053 | insn->a_reg = A_REG; |
| 1054 | insn->x_reg = TMP_REG; |
| 1055 | break; |
| 1056 | |
| 1057 | /* RET_K, RET_A are remaped into 2 insns. */ |
| 1058 | case BPF_RET | BPF_A: |
| 1059 | case BPF_RET | BPF_K: |
| 1060 | insn->code = BPF_ALU | BPF_MOV | |
| 1061 | (BPF_RVAL(fp->code) == BPF_K ? |
| 1062 | BPF_K : BPF_X); |
| 1063 | insn->a_reg = 0; |
| 1064 | insn->x_reg = A_REG; |
| 1065 | insn->imm = fp->k; |
| 1066 | insn++; |
| 1067 | |
| 1068 | insn->code = BPF_JMP | BPF_EXIT; |
| 1069 | break; |
| 1070 | |
| 1071 | /* Store to stack. */ |
| 1072 | case BPF_ST: |
| 1073 | case BPF_STX: |
| 1074 | insn->code = BPF_STX | BPF_MEM | BPF_W; |
| 1075 | insn->a_reg = FP_REG; |
| 1076 | insn->x_reg = fp->code == BPF_ST ? A_REG : X_REG; |
| 1077 | insn->off = -(BPF_MEMWORDS - fp->k) * 4; |
| 1078 | break; |
| 1079 | |
| 1080 | /* Load from stack. */ |
| 1081 | case BPF_LD | BPF_MEM: |
| 1082 | case BPF_LDX | BPF_MEM: |
| 1083 | insn->code = BPF_LDX | BPF_MEM | BPF_W; |
| 1084 | insn->a_reg = BPF_CLASS(fp->code) == BPF_LD ? |
| 1085 | A_REG : X_REG; |
| 1086 | insn->x_reg = FP_REG; |
| 1087 | insn->off = -(BPF_MEMWORDS - fp->k) * 4; |
| 1088 | break; |
| 1089 | |
| 1090 | /* A = K or X = K */ |
| 1091 | case BPF_LD | BPF_IMM: |
| 1092 | case BPF_LDX | BPF_IMM: |
| 1093 | insn->code = BPF_ALU | BPF_MOV | BPF_K; |
| 1094 | insn->a_reg = BPF_CLASS(fp->code) == BPF_LD ? |
| 1095 | A_REG : X_REG; |
| 1096 | insn->imm = fp->k; |
| 1097 | break; |
| 1098 | |
| 1099 | /* X = A */ |
| 1100 | case BPF_MISC | BPF_TAX: |
| 1101 | insn->code = BPF_ALU64 | BPF_MOV | BPF_X; |
| 1102 | insn->a_reg = X_REG; |
| 1103 | insn->x_reg = A_REG; |
| 1104 | break; |
| 1105 | |
| 1106 | /* A = X */ |
| 1107 | case BPF_MISC | BPF_TXA: |
| 1108 | insn->code = BPF_ALU64 | BPF_MOV | BPF_X; |
| 1109 | insn->a_reg = A_REG; |
| 1110 | insn->x_reg = X_REG; |
| 1111 | break; |
| 1112 | |
| 1113 | /* A = skb->len or X = skb->len */ |
| 1114 | case BPF_LD | BPF_W | BPF_LEN: |
| 1115 | case BPF_LDX | BPF_W | BPF_LEN: |
| 1116 | insn->code = BPF_LDX | BPF_MEM | BPF_W; |
| 1117 | insn->a_reg = BPF_CLASS(fp->code) == BPF_LD ? |
| 1118 | A_REG : X_REG; |
| 1119 | insn->x_reg = CTX_REG; |
| 1120 | insn->off = offsetof(struct sk_buff, len); |
| 1121 | break; |
| 1122 | |
| 1123 | /* access seccomp_data fields */ |
| 1124 | case BPF_LDX | BPF_ABS | BPF_W: |
| 1125 | insn->code = BPF_LDX | BPF_MEM | BPF_W; |
| 1126 | insn->a_reg = A_REG; |
| 1127 | insn->x_reg = CTX_REG; |
| 1128 | insn->off = fp->k; |
| 1129 | break; |
| 1130 | |
| 1131 | default: |
| 1132 | goto err; |
| 1133 | } |
| 1134 | |
| 1135 | insn++; |
| 1136 | if (new_prog) |
| 1137 | memcpy(new_insn, tmp_insns, |
| 1138 | sizeof(*insn) * (insn - tmp_insns)); |
| 1139 | |
| 1140 | new_insn += insn - tmp_insns; |
| 1141 | } |
| 1142 | |
| 1143 | if (!new_prog) { |
| 1144 | /* Only calculating new length. */ |
| 1145 | *new_len = new_insn - new_prog; |
| 1146 | return 0; |
| 1147 | } |
| 1148 | |
| 1149 | pass++; |
| 1150 | if (new_flen != new_insn - new_prog) { |
| 1151 | new_flen = new_insn - new_prog; |
| 1152 | if (pass > 2) |
| 1153 | goto err; |
| 1154 | |
| 1155 | goto do_pass; |
| 1156 | } |
| 1157 | |
| 1158 | kfree(addrs); |
| 1159 | BUG_ON(*new_len != new_flen); |
| 1160 | return 0; |
| 1161 | err: |
| 1162 | kfree(addrs); |
| 1163 | return -EINVAL; |
| 1164 | } |
| 1165 | |
| 1166 | /* Security: |
| 1167 | * |
Eric Dumazet | 2d5311e | 2010-12-01 20:46:24 +0000 | [diff] [blame] | 1168 | * 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] | 1169 | * values (check u32 mem[BPF_MEMWORDS] in sk_run_filter()). |
| 1170 | * |
Eric Dumazet | 2d5311e | 2010-12-01 20:46:24 +0000 | [diff] [blame] | 1171 | * As we dont want to clear mem[] array for each packet going through |
| 1172 | * sk_run_filter(), we check that filter loaded by user never try to read |
| 1173 | * 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] | 1174 | * a malicious user doesn't try to abuse us. |
Eric Dumazet | 2d5311e | 2010-12-01 20:46:24 +0000 | [diff] [blame] | 1175 | */ |
| 1176 | static int check_load_and_stores(struct sock_filter *filter, int flen) |
| 1177 | { |
| 1178 | u16 *masks, memvalid = 0; /* one bit per cell, 16 cells */ |
| 1179 | int pc, ret = 0; |
| 1180 | |
| 1181 | BUILD_BUG_ON(BPF_MEMWORDS > 16); |
| 1182 | masks = kmalloc(flen * sizeof(*masks), GFP_KERNEL); |
| 1183 | if (!masks) |
| 1184 | return -ENOMEM; |
| 1185 | memset(masks, 0xff, flen * sizeof(*masks)); |
| 1186 | |
| 1187 | for (pc = 0; pc < flen; pc++) { |
| 1188 | memvalid &= masks[pc]; |
| 1189 | |
| 1190 | switch (filter[pc].code) { |
| 1191 | case BPF_S_ST: |
| 1192 | case BPF_S_STX: |
| 1193 | memvalid |= (1 << filter[pc].k); |
| 1194 | break; |
| 1195 | case BPF_S_LD_MEM: |
| 1196 | case BPF_S_LDX_MEM: |
| 1197 | if (!(memvalid & (1 << filter[pc].k))) { |
| 1198 | ret = -EINVAL; |
| 1199 | goto error; |
| 1200 | } |
| 1201 | break; |
| 1202 | case BPF_S_JMP_JA: |
| 1203 | /* a jump must set masks on target */ |
| 1204 | masks[pc + 1 + filter[pc].k] &= memvalid; |
| 1205 | memvalid = ~0; |
| 1206 | break; |
| 1207 | case BPF_S_JMP_JEQ_K: |
| 1208 | case BPF_S_JMP_JEQ_X: |
| 1209 | case BPF_S_JMP_JGE_K: |
| 1210 | case BPF_S_JMP_JGE_X: |
| 1211 | case BPF_S_JMP_JGT_K: |
| 1212 | case BPF_S_JMP_JGT_X: |
| 1213 | case BPF_S_JMP_JSET_X: |
| 1214 | case BPF_S_JMP_JSET_K: |
| 1215 | /* a jump must set masks on targets */ |
| 1216 | masks[pc + 1 + filter[pc].jt] &= memvalid; |
| 1217 | masks[pc + 1 + filter[pc].jf] &= memvalid; |
| 1218 | memvalid = ~0; |
| 1219 | break; |
| 1220 | } |
| 1221 | } |
| 1222 | error: |
| 1223 | kfree(masks); |
| 1224 | return ret; |
| 1225 | } |
| 1226 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1227 | /** |
| 1228 | * sk_chk_filter - verify socket filter code |
| 1229 | * @filter: filter to verify |
| 1230 | * @flen: length of filter |
| 1231 | * |
| 1232 | * Check the user's filter code. If we let some ugly |
| 1233 | * filter code slip through kaboom! The filter must contain |
Kris Katterjohn | 9369986 | 2006-01-04 13:58:36 -0800 | [diff] [blame] | 1234 | * no references or jumps that are out of range, no illegal |
| 1235 | * instructions, and must end with a RET instruction. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1236 | * |
Kris Katterjohn | 7b11f69 | 2006-01-13 14:33:06 -0800 | [diff] [blame] | 1237 | * All jumps are forward as they are not signed. |
| 1238 | * |
| 1239 | * Returns 0 if the rule set is legal or -EINVAL if not. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1240 | */ |
Dan Carpenter | 4f25af2 | 2011-10-17 21:04:20 +0000 | [diff] [blame] | 1241 | int sk_chk_filter(struct sock_filter *filter, unsigned int flen) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1242 | { |
Tetsuo Handa | cba328f | 2010-11-16 15:19:51 +0000 | [diff] [blame] | 1243 | /* |
| 1244 | * Valid instructions are initialized to non-0. |
| 1245 | * Invalid instructions are initialized to 0. |
| 1246 | */ |
| 1247 | static const u8 codes[] = { |
Eric Dumazet | 8c1592d | 2010-11-18 21:56:38 +0000 | [diff] [blame] | 1248 | [BPF_ALU|BPF_ADD|BPF_K] = BPF_S_ALU_ADD_K, |
| 1249 | [BPF_ALU|BPF_ADD|BPF_X] = BPF_S_ALU_ADD_X, |
| 1250 | [BPF_ALU|BPF_SUB|BPF_K] = BPF_S_ALU_SUB_K, |
| 1251 | [BPF_ALU|BPF_SUB|BPF_X] = BPF_S_ALU_SUB_X, |
| 1252 | [BPF_ALU|BPF_MUL|BPF_K] = BPF_S_ALU_MUL_K, |
| 1253 | [BPF_ALU|BPF_MUL|BPF_X] = BPF_S_ALU_MUL_X, |
| 1254 | [BPF_ALU|BPF_DIV|BPF_X] = BPF_S_ALU_DIV_X, |
Eric Dumazet | b6069a9 | 2012-09-07 22:03:35 +0000 | [diff] [blame] | 1255 | [BPF_ALU|BPF_MOD|BPF_K] = BPF_S_ALU_MOD_K, |
| 1256 | [BPF_ALU|BPF_MOD|BPF_X] = BPF_S_ALU_MOD_X, |
Eric Dumazet | 8c1592d | 2010-11-18 21:56:38 +0000 | [diff] [blame] | 1257 | [BPF_ALU|BPF_AND|BPF_K] = BPF_S_ALU_AND_K, |
| 1258 | [BPF_ALU|BPF_AND|BPF_X] = BPF_S_ALU_AND_X, |
| 1259 | [BPF_ALU|BPF_OR|BPF_K] = BPF_S_ALU_OR_K, |
| 1260 | [BPF_ALU|BPF_OR|BPF_X] = BPF_S_ALU_OR_X, |
Daniel Borkmann | 9e49e88 | 2012-09-24 02:23:59 +0000 | [diff] [blame] | 1261 | [BPF_ALU|BPF_XOR|BPF_K] = BPF_S_ALU_XOR_K, |
| 1262 | [BPF_ALU|BPF_XOR|BPF_X] = BPF_S_ALU_XOR_X, |
Eric Dumazet | 8c1592d | 2010-11-18 21:56:38 +0000 | [diff] [blame] | 1263 | [BPF_ALU|BPF_LSH|BPF_K] = BPF_S_ALU_LSH_K, |
| 1264 | [BPF_ALU|BPF_LSH|BPF_X] = BPF_S_ALU_LSH_X, |
| 1265 | [BPF_ALU|BPF_RSH|BPF_K] = BPF_S_ALU_RSH_K, |
| 1266 | [BPF_ALU|BPF_RSH|BPF_X] = BPF_S_ALU_RSH_X, |
| 1267 | [BPF_ALU|BPF_NEG] = BPF_S_ALU_NEG, |
| 1268 | [BPF_LD|BPF_W|BPF_ABS] = BPF_S_LD_W_ABS, |
| 1269 | [BPF_LD|BPF_H|BPF_ABS] = BPF_S_LD_H_ABS, |
| 1270 | [BPF_LD|BPF_B|BPF_ABS] = BPF_S_LD_B_ABS, |
| 1271 | [BPF_LD|BPF_W|BPF_LEN] = BPF_S_LD_W_LEN, |
| 1272 | [BPF_LD|BPF_W|BPF_IND] = BPF_S_LD_W_IND, |
| 1273 | [BPF_LD|BPF_H|BPF_IND] = BPF_S_LD_H_IND, |
| 1274 | [BPF_LD|BPF_B|BPF_IND] = BPF_S_LD_B_IND, |
| 1275 | [BPF_LD|BPF_IMM] = BPF_S_LD_IMM, |
| 1276 | [BPF_LDX|BPF_W|BPF_LEN] = BPF_S_LDX_W_LEN, |
| 1277 | [BPF_LDX|BPF_B|BPF_MSH] = BPF_S_LDX_B_MSH, |
| 1278 | [BPF_LDX|BPF_IMM] = BPF_S_LDX_IMM, |
| 1279 | [BPF_MISC|BPF_TAX] = BPF_S_MISC_TAX, |
| 1280 | [BPF_MISC|BPF_TXA] = BPF_S_MISC_TXA, |
| 1281 | [BPF_RET|BPF_K] = BPF_S_RET_K, |
| 1282 | [BPF_RET|BPF_A] = BPF_S_RET_A, |
| 1283 | [BPF_ALU|BPF_DIV|BPF_K] = BPF_S_ALU_DIV_K, |
| 1284 | [BPF_LD|BPF_MEM] = BPF_S_LD_MEM, |
| 1285 | [BPF_LDX|BPF_MEM] = BPF_S_LDX_MEM, |
| 1286 | [BPF_ST] = BPF_S_ST, |
| 1287 | [BPF_STX] = BPF_S_STX, |
| 1288 | [BPF_JMP|BPF_JA] = BPF_S_JMP_JA, |
| 1289 | [BPF_JMP|BPF_JEQ|BPF_K] = BPF_S_JMP_JEQ_K, |
| 1290 | [BPF_JMP|BPF_JEQ|BPF_X] = BPF_S_JMP_JEQ_X, |
| 1291 | [BPF_JMP|BPF_JGE|BPF_K] = BPF_S_JMP_JGE_K, |
| 1292 | [BPF_JMP|BPF_JGE|BPF_X] = BPF_S_JMP_JGE_X, |
| 1293 | [BPF_JMP|BPF_JGT|BPF_K] = BPF_S_JMP_JGT_K, |
| 1294 | [BPF_JMP|BPF_JGT|BPF_X] = BPF_S_JMP_JGT_X, |
| 1295 | [BPF_JMP|BPF_JSET|BPF_K] = BPF_S_JMP_JSET_K, |
| 1296 | [BPF_JMP|BPF_JSET|BPF_X] = BPF_S_JMP_JSET_X, |
Tetsuo Handa | cba328f | 2010-11-16 15:19:51 +0000 | [diff] [blame] | 1297 | }; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1298 | int pc; |
Daniel Borkmann | aa1113d | 2012-12-28 10:50:17 +0000 | [diff] [blame] | 1299 | bool anc_found; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1300 | |
David S. Miller | 1b93ae64 | 2005-12-27 13:57:59 -0800 | [diff] [blame] | 1301 | if (flen == 0 || flen > BPF_MAXINSNS) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1302 | return -EINVAL; |
| 1303 | |
| 1304 | /* check the filter code now */ |
| 1305 | for (pc = 0; pc < flen; pc++) { |
Tetsuo Handa | cba328f | 2010-11-16 15:19:51 +0000 | [diff] [blame] | 1306 | struct sock_filter *ftest = &filter[pc]; |
| 1307 | u16 code = ftest->code; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1308 | |
Tetsuo Handa | cba328f | 2010-11-16 15:19:51 +0000 | [diff] [blame] | 1309 | if (code >= ARRAY_SIZE(codes)) |
| 1310 | return -EINVAL; |
| 1311 | code = codes[code]; |
Eric Dumazet | 8c1592d | 2010-11-18 21:56:38 +0000 | [diff] [blame] | 1312 | if (!code) |
Tetsuo Handa | cba328f | 2010-11-16 15:19:51 +0000 | [diff] [blame] | 1313 | return -EINVAL; |
Kris Katterjohn | 9369986 | 2006-01-04 13:58:36 -0800 | [diff] [blame] | 1314 | /* Some instructions need special checks */ |
Tetsuo Handa | cba328f | 2010-11-16 15:19:51 +0000 | [diff] [blame] | 1315 | switch (code) { |
| 1316 | case BPF_S_ALU_DIV_K: |
Eric Dumazet | b6069a9 | 2012-09-07 22:03:35 +0000 | [diff] [blame] | 1317 | case BPF_S_ALU_MOD_K: |
| 1318 | /* check for division by zero */ |
| 1319 | if (ftest->k == 0) |
| 1320 | return -EINVAL; |
| 1321 | break; |
Tetsuo Handa | cba328f | 2010-11-16 15:19:51 +0000 | [diff] [blame] | 1322 | case BPF_S_LD_MEM: |
| 1323 | case BPF_S_LDX_MEM: |
| 1324 | case BPF_S_ST: |
| 1325 | case BPF_S_STX: |
| 1326 | /* check for invalid memory addresses */ |
Kris Katterjohn | 9369986 | 2006-01-04 13:58:36 -0800 | [diff] [blame] | 1327 | if (ftest->k >= BPF_MEMWORDS) |
| 1328 | return -EINVAL; |
Hagen Paul Pfeifer | 01f2f3f | 2010-06-19 17:05:36 +0000 | [diff] [blame] | 1329 | break; |
Tetsuo Handa | cba328f | 2010-11-16 15:19:51 +0000 | [diff] [blame] | 1330 | case BPF_S_JMP_JA: |
Kris Katterjohn | 9369986 | 2006-01-04 13:58:36 -0800 | [diff] [blame] | 1331 | /* |
| 1332 | * Note, the large ftest->k might cause loops. |
| 1333 | * Compare this with conditional jumps below, |
| 1334 | * where offsets are limited. --ANK (981016) |
| 1335 | */ |
Eric Dumazet | 95c9617 | 2012-04-15 05:58:06 +0000 | [diff] [blame] | 1336 | if (ftest->k >= (unsigned int)(flen-pc-1)) |
Kris Katterjohn | 9369986 | 2006-01-04 13:58:36 -0800 | [diff] [blame] | 1337 | return -EINVAL; |
| 1338 | break; |
Hagen Paul Pfeifer | 01f2f3f | 2010-06-19 17:05:36 +0000 | [diff] [blame] | 1339 | case BPF_S_JMP_JEQ_K: |
| 1340 | case BPF_S_JMP_JEQ_X: |
| 1341 | case BPF_S_JMP_JGE_K: |
| 1342 | case BPF_S_JMP_JGE_X: |
| 1343 | case BPF_S_JMP_JGT_K: |
| 1344 | case BPF_S_JMP_JGT_X: |
| 1345 | case BPF_S_JMP_JSET_X: |
| 1346 | case BPF_S_JMP_JSET_K: |
Tetsuo Handa | cba328f | 2010-11-16 15:19:51 +0000 | [diff] [blame] | 1347 | /* for conditionals both must be safe */ |
Hagen Paul Pfeifer | 01f2f3f | 2010-06-19 17:05:36 +0000 | [diff] [blame] | 1348 | if (pc + ftest->jt + 1 >= flen || |
| 1349 | pc + ftest->jf + 1 >= flen) |
| 1350 | return -EINVAL; |
Tetsuo Handa | cba328f | 2010-11-16 15:19:51 +0000 | [diff] [blame] | 1351 | break; |
Eric Dumazet | 12b16da | 2010-12-15 19:45:28 +0000 | [diff] [blame] | 1352 | case BPF_S_LD_W_ABS: |
| 1353 | case BPF_S_LD_H_ABS: |
| 1354 | case BPF_S_LD_B_ABS: |
Daniel Borkmann | aa1113d | 2012-12-28 10:50:17 +0000 | [diff] [blame] | 1355 | anc_found = false; |
Eric Dumazet | 12b16da | 2010-12-15 19:45:28 +0000 | [diff] [blame] | 1356 | #define ANCILLARY(CODE) case SKF_AD_OFF + SKF_AD_##CODE: \ |
| 1357 | code = BPF_S_ANC_##CODE; \ |
Daniel Borkmann | aa1113d | 2012-12-28 10:50:17 +0000 | [diff] [blame] | 1358 | anc_found = true; \ |
Eric Dumazet | 12b16da | 2010-12-15 19:45:28 +0000 | [diff] [blame] | 1359 | break |
| 1360 | switch (ftest->k) { |
| 1361 | ANCILLARY(PROTOCOL); |
| 1362 | ANCILLARY(PKTTYPE); |
| 1363 | ANCILLARY(IFINDEX); |
| 1364 | ANCILLARY(NLATTR); |
| 1365 | ANCILLARY(NLATTR_NEST); |
| 1366 | ANCILLARY(MARK); |
| 1367 | ANCILLARY(QUEUE); |
| 1368 | ANCILLARY(HATYPE); |
| 1369 | ANCILLARY(RXHASH); |
| 1370 | ANCILLARY(CPU); |
Jiri Pirko | ffe06c1 | 2012-03-31 11:01:20 +0000 | [diff] [blame] | 1371 | ANCILLARY(ALU_XOR_X); |
Eric Dumazet | f333503 | 2012-10-27 02:26:17 +0000 | [diff] [blame] | 1372 | ANCILLARY(VLAN_TAG); |
| 1373 | ANCILLARY(VLAN_TAG_PRESENT); |
Daniel Borkmann | 3e5289d | 2013-03-19 06:39:31 +0000 | [diff] [blame] | 1374 | ANCILLARY(PAY_OFFSET); |
Chema Gonzalez | 4cd3675 | 2014-04-21 09:21:24 -0700 | [diff] [blame] | 1375 | ANCILLARY(RANDOM); |
Eric Dumazet | 12b16da | 2010-12-15 19:45:28 +0000 | [diff] [blame] | 1376 | } |
Daniel Borkmann | aa1113d | 2012-12-28 10:50:17 +0000 | [diff] [blame] | 1377 | |
| 1378 | /* ancillary operation unknown or unsupported */ |
| 1379 | if (anc_found == false && ftest->k >= SKF_AD_OFF) |
| 1380 | return -EINVAL; |
Hagen Paul Pfeifer | 01f2f3f | 2010-06-19 17:05:36 +0000 | [diff] [blame] | 1381 | } |
Tetsuo Handa | cba328f | 2010-11-16 15:19:51 +0000 | [diff] [blame] | 1382 | ftest->code = code; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1383 | } |
| 1384 | |
Hagen Paul Pfeifer | 01f2f3f | 2010-06-19 17:05:36 +0000 | [diff] [blame] | 1385 | /* last instruction must be a RET code */ |
| 1386 | switch (filter[flen - 1].code) { |
| 1387 | case BPF_S_RET_K: |
| 1388 | case BPF_S_RET_A: |
Eric Dumazet | 2d5311e | 2010-12-01 20:46:24 +0000 | [diff] [blame] | 1389 | return check_load_and_stores(filter, flen); |
Tetsuo Handa | cba328f | 2010-11-16 15:19:51 +0000 | [diff] [blame] | 1390 | } |
| 1391 | return -EINVAL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1392 | } |
Stephen Hemminger | b715631 | 2008-04-10 01:33:47 -0700 | [diff] [blame] | 1393 | EXPORT_SYMBOL(sk_chk_filter); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1394 | |
Daniel Borkmann | a3ea269 | 2014-03-28 18:58:19 +0100 | [diff] [blame] | 1395 | static int sk_store_orig_filter(struct sk_filter *fp, |
| 1396 | const struct sock_fprog *fprog) |
| 1397 | { |
| 1398 | unsigned int fsize = sk_filter_proglen(fprog); |
| 1399 | struct sock_fprog_kern *fkprog; |
| 1400 | |
| 1401 | fp->orig_prog = kmalloc(sizeof(*fkprog), GFP_KERNEL); |
| 1402 | if (!fp->orig_prog) |
| 1403 | return -ENOMEM; |
| 1404 | |
| 1405 | fkprog = fp->orig_prog; |
| 1406 | fkprog->len = fprog->len; |
| 1407 | fkprog->filter = kmemdup(fp->insns, fsize, GFP_KERNEL); |
| 1408 | if (!fkprog->filter) { |
| 1409 | kfree(fp->orig_prog); |
| 1410 | return -ENOMEM; |
| 1411 | } |
| 1412 | |
| 1413 | return 0; |
| 1414 | } |
| 1415 | |
| 1416 | static void sk_release_orig_filter(struct sk_filter *fp) |
| 1417 | { |
| 1418 | struct sock_fprog_kern *fprog = fp->orig_prog; |
| 1419 | |
| 1420 | if (fprog) { |
| 1421 | kfree(fprog->filter); |
| 1422 | kfree(fprog); |
| 1423 | } |
| 1424 | } |
| 1425 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1426 | /** |
Eric Dumazet | 46bcf14 | 2010-12-06 09:29:43 -0800 | [diff] [blame] | 1427 | * sk_filter_release_rcu - Release a socket filter by rcu_head |
Pavel Emelyanov | 47e958e | 2007-10-17 21:22:42 -0700 | [diff] [blame] | 1428 | * @rcu: rcu_head that contains the sk_filter to free |
| 1429 | */ |
Daniel Borkmann | fbc907f | 2014-03-28 18:58:20 +0100 | [diff] [blame] | 1430 | static void sk_filter_release_rcu(struct rcu_head *rcu) |
Pavel Emelyanov | 47e958e | 2007-10-17 21:22:42 -0700 | [diff] [blame] | 1431 | { |
| 1432 | struct sk_filter *fp = container_of(rcu, struct sk_filter, rcu); |
| 1433 | |
Daniel Borkmann | a3ea269 | 2014-03-28 18:58:19 +0100 | [diff] [blame] | 1434 | sk_release_orig_filter(fp); |
Eric Dumazet | 0a14842 | 2011-04-20 09:27:32 +0000 | [diff] [blame] | 1435 | bpf_jit_free(fp); |
Pavel Emelyanov | 47e958e | 2007-10-17 21:22:42 -0700 | [diff] [blame] | 1436 | } |
Daniel Borkmann | fbc907f | 2014-03-28 18:58:20 +0100 | [diff] [blame] | 1437 | |
| 1438 | /** |
| 1439 | * sk_filter_release - release a socket filter |
| 1440 | * @fp: filter to remove |
| 1441 | * |
| 1442 | * Remove a filter from a socket and release its resources. |
| 1443 | */ |
| 1444 | static void sk_filter_release(struct sk_filter *fp) |
| 1445 | { |
| 1446 | if (atomic_dec_and_test(&fp->refcnt)) |
| 1447 | call_rcu(&fp->rcu, sk_filter_release_rcu); |
| 1448 | } |
| 1449 | |
| 1450 | void sk_filter_uncharge(struct sock *sk, struct sk_filter *fp) |
| 1451 | { |
| 1452 | atomic_sub(sk_filter_size(fp->len), &sk->sk_omem_alloc); |
| 1453 | sk_filter_release(fp); |
| 1454 | } |
| 1455 | |
| 1456 | void sk_filter_charge(struct sock *sk, struct sk_filter *fp) |
| 1457 | { |
| 1458 | atomic_inc(&fp->refcnt); |
| 1459 | atomic_add(sk_filter_size(fp->len), &sk->sk_omem_alloc); |
| 1460 | } |
Pavel Emelyanov | 47e958e | 2007-10-17 21:22:42 -0700 | [diff] [blame] | 1461 | |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 1462 | static struct sk_filter *__sk_migrate_realloc(struct sk_filter *fp, |
| 1463 | struct sock *sk, |
| 1464 | unsigned int len) |
| 1465 | { |
| 1466 | struct sk_filter *fp_new; |
| 1467 | |
| 1468 | if (sk == NULL) |
| 1469 | return krealloc(fp, len, GFP_KERNEL); |
| 1470 | |
| 1471 | fp_new = sock_kmalloc(sk, len, GFP_KERNEL); |
| 1472 | if (fp_new) { |
| 1473 | memcpy(fp_new, fp, sizeof(struct sk_filter)); |
| 1474 | /* As we're kepping orig_prog in fp_new along, |
| 1475 | * we need to make sure we're not evicting it |
| 1476 | * from the old fp. |
| 1477 | */ |
| 1478 | fp->orig_prog = NULL; |
| 1479 | sk_filter_uncharge(sk, fp); |
| 1480 | } |
| 1481 | |
| 1482 | return fp_new; |
| 1483 | } |
| 1484 | |
| 1485 | static struct sk_filter *__sk_migrate_filter(struct sk_filter *fp, |
| 1486 | struct sock *sk) |
| 1487 | { |
| 1488 | struct sock_filter *old_prog; |
| 1489 | struct sk_filter *old_fp; |
| 1490 | int i, err, new_len, old_len = fp->len; |
| 1491 | |
| 1492 | /* We are free to overwrite insns et al right here as it |
| 1493 | * won't be used at this point in time anymore internally |
| 1494 | * after the migration to the internal BPF instruction |
| 1495 | * representation. |
| 1496 | */ |
| 1497 | BUILD_BUG_ON(sizeof(struct sock_filter) != |
| 1498 | sizeof(struct sock_filter_int)); |
| 1499 | |
| 1500 | /* For now, we need to unfiddle BPF_S_* identifiers in place. |
| 1501 | * This can sooner or later on be subject to removal, e.g. when |
| 1502 | * JITs have been converted. |
| 1503 | */ |
| 1504 | for (i = 0; i < fp->len; i++) |
| 1505 | sk_decode_filter(&fp->insns[i], &fp->insns[i]); |
| 1506 | |
| 1507 | /* Conversion cannot happen on overlapping memory areas, |
| 1508 | * so we need to keep the user BPF around until the 2nd |
| 1509 | * pass. At this time, the user BPF is stored in fp->insns. |
| 1510 | */ |
| 1511 | old_prog = kmemdup(fp->insns, old_len * sizeof(struct sock_filter), |
| 1512 | GFP_KERNEL); |
| 1513 | if (!old_prog) { |
| 1514 | err = -ENOMEM; |
| 1515 | goto out_err; |
| 1516 | } |
| 1517 | |
| 1518 | /* 1st pass: calculate the new program length. */ |
| 1519 | err = sk_convert_filter(old_prog, old_len, NULL, &new_len); |
| 1520 | if (err) |
| 1521 | goto out_err_free; |
| 1522 | |
| 1523 | /* Expand fp for appending the new filter representation. */ |
| 1524 | old_fp = fp; |
| 1525 | fp = __sk_migrate_realloc(old_fp, sk, sk_filter_size(new_len)); |
| 1526 | if (!fp) { |
| 1527 | /* The old_fp is still around in case we couldn't |
| 1528 | * allocate new memory, so uncharge on that one. |
| 1529 | */ |
| 1530 | fp = old_fp; |
| 1531 | err = -ENOMEM; |
| 1532 | goto out_err_free; |
| 1533 | } |
| 1534 | |
| 1535 | fp->bpf_func = sk_run_filter_int_skb; |
| 1536 | fp->len = new_len; |
| 1537 | |
| 1538 | /* 2nd pass: remap sock_filter insns into sock_filter_int insns. */ |
| 1539 | err = sk_convert_filter(old_prog, old_len, fp->insnsi, &new_len); |
| 1540 | if (err) |
| 1541 | /* 2nd sk_convert_filter() can fail only if it fails |
| 1542 | * to allocate memory, remapping must succeed. Note, |
| 1543 | * that at this time old_fp has already been released |
| 1544 | * by __sk_migrate_realloc(). |
| 1545 | */ |
| 1546 | goto out_err_free; |
| 1547 | |
| 1548 | kfree(old_prog); |
| 1549 | return fp; |
| 1550 | |
| 1551 | out_err_free: |
| 1552 | kfree(old_prog); |
| 1553 | out_err: |
| 1554 | /* Rollback filter setup. */ |
| 1555 | if (sk != NULL) |
| 1556 | sk_filter_uncharge(sk, fp); |
| 1557 | else |
| 1558 | kfree(fp); |
| 1559 | return ERR_PTR(err); |
| 1560 | } |
| 1561 | |
| 1562 | static struct sk_filter *__sk_prepare_filter(struct sk_filter *fp, |
| 1563 | struct sock *sk) |
Jiri Pirko | 302d663 | 2012-03-31 11:01:19 +0000 | [diff] [blame] | 1564 | { |
| 1565 | int err; |
| 1566 | |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 1567 | fp->bpf_func = NULL; |
Daniel Borkmann | f8bbbfc | 2014-03-28 18:58:18 +0100 | [diff] [blame] | 1568 | fp->jited = 0; |
Jiri Pirko | 302d663 | 2012-03-31 11:01:19 +0000 | [diff] [blame] | 1569 | |
| 1570 | err = sk_chk_filter(fp->insns, fp->len); |
| 1571 | if (err) |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 1572 | return ERR_PTR(err); |
Jiri Pirko | 302d663 | 2012-03-31 11:01:19 +0000 | [diff] [blame] | 1573 | |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 1574 | /* Probe if we can JIT compile the filter and if so, do |
| 1575 | * the compilation of the filter. |
| 1576 | */ |
Jiri Pirko | 302d663 | 2012-03-31 11:01:19 +0000 | [diff] [blame] | 1577 | bpf_jit_compile(fp); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 1578 | |
| 1579 | /* JIT compiler couldn't process this filter, so do the |
| 1580 | * internal BPF translation for the optimized interpreter. |
| 1581 | */ |
| 1582 | if (!fp->jited) |
| 1583 | fp = __sk_migrate_filter(fp, sk); |
| 1584 | |
| 1585 | return fp; |
Jiri Pirko | 302d663 | 2012-03-31 11:01:19 +0000 | [diff] [blame] | 1586 | } |
| 1587 | |
| 1588 | /** |
| 1589 | * sk_unattached_filter_create - create an unattached filter |
| 1590 | * @fprog: the filter program |
Randy Dunlap | c6c4b97 | 2012-06-08 14:01:44 +0000 | [diff] [blame] | 1591 | * @pfp: the unattached filter that is created |
Jiri Pirko | 302d663 | 2012-03-31 11:01:19 +0000 | [diff] [blame] | 1592 | * |
Randy Dunlap | c6c4b97 | 2012-06-08 14:01:44 +0000 | [diff] [blame] | 1593 | * Create a filter independent of any socket. We first run some |
Jiri Pirko | 302d663 | 2012-03-31 11:01:19 +0000 | [diff] [blame] | 1594 | * sanity checks on it to make sure it does not explode on us later. |
| 1595 | * If an error occurs or there is insufficient memory for the filter |
| 1596 | * a negative errno code is returned. On success the return is zero. |
| 1597 | */ |
| 1598 | int sk_unattached_filter_create(struct sk_filter **pfp, |
| 1599 | struct sock_fprog *fprog) |
| 1600 | { |
Daniel Borkmann | a3ea269 | 2014-03-28 18:58:19 +0100 | [diff] [blame] | 1601 | unsigned int fsize = sk_filter_proglen(fprog); |
Jiri Pirko | 302d663 | 2012-03-31 11:01:19 +0000 | [diff] [blame] | 1602 | struct sk_filter *fp; |
Jiri Pirko | 302d663 | 2012-03-31 11:01:19 +0000 | [diff] [blame] | 1603 | |
| 1604 | /* Make sure new filter is there and in the right amounts. */ |
| 1605 | if (fprog->filter == NULL) |
| 1606 | return -EINVAL; |
| 1607 | |
Alexei Starovoitov | d45ed4a | 2013-10-04 00:14:06 -0700 | [diff] [blame] | 1608 | fp = kmalloc(sk_filter_size(fprog->len), GFP_KERNEL); |
Jiri Pirko | 302d663 | 2012-03-31 11:01:19 +0000 | [diff] [blame] | 1609 | if (!fp) |
| 1610 | return -ENOMEM; |
Daniel Borkmann | a3ea269 | 2014-03-28 18:58:19 +0100 | [diff] [blame] | 1611 | |
Jiri Pirko | 302d663 | 2012-03-31 11:01:19 +0000 | [diff] [blame] | 1612 | memcpy(fp->insns, fprog->filter, fsize); |
| 1613 | |
| 1614 | atomic_set(&fp->refcnt, 1); |
| 1615 | fp->len = fprog->len; |
Daniel Borkmann | a3ea269 | 2014-03-28 18:58:19 +0100 | [diff] [blame] | 1616 | /* Since unattached filters are not copied back to user |
| 1617 | * space through sk_get_filter(), we do not need to hold |
| 1618 | * a copy here, and can spare us the work. |
| 1619 | */ |
| 1620 | fp->orig_prog = NULL; |
Jiri Pirko | 302d663 | 2012-03-31 11:01:19 +0000 | [diff] [blame] | 1621 | |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 1622 | /* __sk_prepare_filter() already takes care of uncharging |
| 1623 | * memory in case something goes wrong. |
| 1624 | */ |
| 1625 | fp = __sk_prepare_filter(fp, NULL); |
| 1626 | if (IS_ERR(fp)) |
| 1627 | return PTR_ERR(fp); |
Jiri Pirko | 302d663 | 2012-03-31 11:01:19 +0000 | [diff] [blame] | 1628 | |
| 1629 | *pfp = fp; |
| 1630 | return 0; |
Jiri Pirko | 302d663 | 2012-03-31 11:01:19 +0000 | [diff] [blame] | 1631 | } |
| 1632 | EXPORT_SYMBOL_GPL(sk_unattached_filter_create); |
| 1633 | |
| 1634 | void sk_unattached_filter_destroy(struct sk_filter *fp) |
| 1635 | { |
| 1636 | sk_filter_release(fp); |
| 1637 | } |
| 1638 | EXPORT_SYMBOL_GPL(sk_unattached_filter_destroy); |
| 1639 | |
Pavel Emelyanov | 47e958e | 2007-10-17 21:22:42 -0700 | [diff] [blame] | 1640 | /** |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1641 | * sk_attach_filter - attach a socket filter |
| 1642 | * @fprog: the filter program |
| 1643 | * @sk: the socket to use |
| 1644 | * |
| 1645 | * Attach the user's filter code. We first run some sanity checks on |
| 1646 | * it to make sure it does not explode on us later. If an error |
| 1647 | * occurs or there is insufficient memory for the filter a negative |
| 1648 | * errno code is returned. On success the return is zero. |
| 1649 | */ |
| 1650 | int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk) |
| 1651 | { |
Pavel Emelyanov | d3904b7 | 2007-10-17 21:22:17 -0700 | [diff] [blame] | 1652 | struct sk_filter *fp, *old_fp; |
Daniel Borkmann | a3ea269 | 2014-03-28 18:58:19 +0100 | [diff] [blame] | 1653 | unsigned int fsize = sk_filter_proglen(fprog); |
Alexei Starovoitov | d45ed4a | 2013-10-04 00:14:06 -0700 | [diff] [blame] | 1654 | unsigned int sk_fsize = sk_filter_size(fprog->len); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1655 | int err; |
| 1656 | |
Vincent Bernat | d59577b | 2013-01-16 22:55:49 +0100 | [diff] [blame] | 1657 | if (sock_flag(sk, SOCK_FILTER_LOCKED)) |
| 1658 | return -EPERM; |
| 1659 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1660 | /* Make sure new filter is there and in the right amounts. */ |
Kris Katterjohn | e35bedf | 2006-01-17 02:25:52 -0800 | [diff] [blame] | 1661 | if (fprog->filter == NULL) |
| 1662 | return -EINVAL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1663 | |
Alexei Starovoitov | d45ed4a | 2013-10-04 00:14:06 -0700 | [diff] [blame] | 1664 | fp = sock_kmalloc(sk, sk_fsize, GFP_KERNEL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1665 | if (!fp) |
| 1666 | return -ENOMEM; |
Daniel Borkmann | a3ea269 | 2014-03-28 18:58:19 +0100 | [diff] [blame] | 1667 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1668 | if (copy_from_user(fp->insns, fprog->filter, fsize)) { |
Alexei Starovoitov | d45ed4a | 2013-10-04 00:14:06 -0700 | [diff] [blame] | 1669 | sock_kfree_s(sk, fp, sk_fsize); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1670 | return -EFAULT; |
| 1671 | } |
| 1672 | |
| 1673 | atomic_set(&fp->refcnt, 1); |
| 1674 | fp->len = fprog->len; |
| 1675 | |
Daniel Borkmann | a3ea269 | 2014-03-28 18:58:19 +0100 | [diff] [blame] | 1676 | err = sk_store_orig_filter(fp, fprog); |
| 1677 | if (err) { |
| 1678 | sk_filter_uncharge(sk, fp); |
| 1679 | return -ENOMEM; |
| 1680 | } |
| 1681 | |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 1682 | /* __sk_prepare_filter() already takes care of uncharging |
| 1683 | * memory in case something goes wrong. |
| 1684 | */ |
| 1685 | fp = __sk_prepare_filter(fp, sk); |
| 1686 | if (IS_ERR(fp)) |
| 1687 | return PTR_ERR(fp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1688 | |
Eric Dumazet | f91ff5b | 2010-09-27 06:07:30 +0000 | [diff] [blame] | 1689 | old_fp = rcu_dereference_protected(sk->sk_filter, |
| 1690 | sock_owned_by_user(sk)); |
Pavel Emelyanov | d3904b7 | 2007-10-17 21:22:17 -0700 | [diff] [blame] | 1691 | rcu_assign_pointer(sk->sk_filter, fp); |
Pavel Emelyanov | d3904b7 | 2007-10-17 21:22:17 -0700 | [diff] [blame] | 1692 | |
Olof Johansson | 9b013e0 | 2007-10-18 21:48:39 -0700 | [diff] [blame] | 1693 | if (old_fp) |
Eric Dumazet | 46bcf14 | 2010-12-06 09:29:43 -0800 | [diff] [blame] | 1694 | sk_filter_uncharge(sk, old_fp); |
Daniel Borkmann | a3ea269 | 2014-03-28 18:58:19 +0100 | [diff] [blame] | 1695 | |
Pavel Emelyanov | d3904b7 | 2007-10-17 21:22:17 -0700 | [diff] [blame] | 1696 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1697 | } |
Michael S. Tsirkin | 5ff3f07 | 2010-02-14 01:01:00 +0000 | [diff] [blame] | 1698 | EXPORT_SYMBOL_GPL(sk_attach_filter); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1699 | |
Pavel Emelyanov | 55b3332 | 2007-10-17 21:21:26 -0700 | [diff] [blame] | 1700 | int sk_detach_filter(struct sock *sk) |
| 1701 | { |
| 1702 | int ret = -ENOENT; |
| 1703 | struct sk_filter *filter; |
| 1704 | |
Vincent Bernat | d59577b | 2013-01-16 22:55:49 +0100 | [diff] [blame] | 1705 | if (sock_flag(sk, SOCK_FILTER_LOCKED)) |
| 1706 | return -EPERM; |
| 1707 | |
Eric Dumazet | f91ff5b | 2010-09-27 06:07:30 +0000 | [diff] [blame] | 1708 | filter = rcu_dereference_protected(sk->sk_filter, |
| 1709 | sock_owned_by_user(sk)); |
Pavel Emelyanov | 55b3332 | 2007-10-17 21:21:26 -0700 | [diff] [blame] | 1710 | if (filter) { |
Stephen Hemminger | a9b3cd7 | 2011-08-01 16:19:00 +0000 | [diff] [blame] | 1711 | RCU_INIT_POINTER(sk->sk_filter, NULL); |
Eric Dumazet | 46bcf14 | 2010-12-06 09:29:43 -0800 | [diff] [blame] | 1712 | sk_filter_uncharge(sk, filter); |
Pavel Emelyanov | 55b3332 | 2007-10-17 21:21:26 -0700 | [diff] [blame] | 1713 | ret = 0; |
| 1714 | } |
Daniel Borkmann | a3ea269 | 2014-03-28 18:58:19 +0100 | [diff] [blame] | 1715 | |
Pavel Emelyanov | 55b3332 | 2007-10-17 21:21:26 -0700 | [diff] [blame] | 1716 | return ret; |
| 1717 | } |
Michael S. Tsirkin | 5ff3f07 | 2010-02-14 01:01:00 +0000 | [diff] [blame] | 1718 | EXPORT_SYMBOL_GPL(sk_detach_filter); |
Pavel Emelyanov | a8fc927 | 2012-11-01 02:01:48 +0000 | [diff] [blame] | 1719 | |
Nicolas Dichtel | ed13998 | 2013-06-05 15:30:55 +0200 | [diff] [blame] | 1720 | void sk_decode_filter(struct sock_filter *filt, struct sock_filter *to) |
Pavel Emelyanov | a8fc927 | 2012-11-01 02:01:48 +0000 | [diff] [blame] | 1721 | { |
| 1722 | static const u16 decodes[] = { |
| 1723 | [BPF_S_ALU_ADD_K] = BPF_ALU|BPF_ADD|BPF_K, |
| 1724 | [BPF_S_ALU_ADD_X] = BPF_ALU|BPF_ADD|BPF_X, |
| 1725 | [BPF_S_ALU_SUB_K] = BPF_ALU|BPF_SUB|BPF_K, |
| 1726 | [BPF_S_ALU_SUB_X] = BPF_ALU|BPF_SUB|BPF_X, |
| 1727 | [BPF_S_ALU_MUL_K] = BPF_ALU|BPF_MUL|BPF_K, |
| 1728 | [BPF_S_ALU_MUL_X] = BPF_ALU|BPF_MUL|BPF_X, |
| 1729 | [BPF_S_ALU_DIV_X] = BPF_ALU|BPF_DIV|BPF_X, |
| 1730 | [BPF_S_ALU_MOD_K] = BPF_ALU|BPF_MOD|BPF_K, |
| 1731 | [BPF_S_ALU_MOD_X] = BPF_ALU|BPF_MOD|BPF_X, |
| 1732 | [BPF_S_ALU_AND_K] = BPF_ALU|BPF_AND|BPF_K, |
| 1733 | [BPF_S_ALU_AND_X] = BPF_ALU|BPF_AND|BPF_X, |
| 1734 | [BPF_S_ALU_OR_K] = BPF_ALU|BPF_OR|BPF_K, |
| 1735 | [BPF_S_ALU_OR_X] = BPF_ALU|BPF_OR|BPF_X, |
| 1736 | [BPF_S_ALU_XOR_K] = BPF_ALU|BPF_XOR|BPF_K, |
| 1737 | [BPF_S_ALU_XOR_X] = BPF_ALU|BPF_XOR|BPF_X, |
| 1738 | [BPF_S_ALU_LSH_K] = BPF_ALU|BPF_LSH|BPF_K, |
| 1739 | [BPF_S_ALU_LSH_X] = BPF_ALU|BPF_LSH|BPF_X, |
| 1740 | [BPF_S_ALU_RSH_K] = BPF_ALU|BPF_RSH|BPF_K, |
| 1741 | [BPF_S_ALU_RSH_X] = BPF_ALU|BPF_RSH|BPF_X, |
| 1742 | [BPF_S_ALU_NEG] = BPF_ALU|BPF_NEG, |
| 1743 | [BPF_S_LD_W_ABS] = BPF_LD|BPF_W|BPF_ABS, |
| 1744 | [BPF_S_LD_H_ABS] = BPF_LD|BPF_H|BPF_ABS, |
| 1745 | [BPF_S_LD_B_ABS] = BPF_LD|BPF_B|BPF_ABS, |
| 1746 | [BPF_S_ANC_PROTOCOL] = BPF_LD|BPF_B|BPF_ABS, |
| 1747 | [BPF_S_ANC_PKTTYPE] = BPF_LD|BPF_B|BPF_ABS, |
| 1748 | [BPF_S_ANC_IFINDEX] = BPF_LD|BPF_B|BPF_ABS, |
| 1749 | [BPF_S_ANC_NLATTR] = BPF_LD|BPF_B|BPF_ABS, |
| 1750 | [BPF_S_ANC_NLATTR_NEST] = BPF_LD|BPF_B|BPF_ABS, |
| 1751 | [BPF_S_ANC_MARK] = BPF_LD|BPF_B|BPF_ABS, |
| 1752 | [BPF_S_ANC_QUEUE] = BPF_LD|BPF_B|BPF_ABS, |
| 1753 | [BPF_S_ANC_HATYPE] = BPF_LD|BPF_B|BPF_ABS, |
| 1754 | [BPF_S_ANC_RXHASH] = BPF_LD|BPF_B|BPF_ABS, |
| 1755 | [BPF_S_ANC_CPU] = BPF_LD|BPF_B|BPF_ABS, |
| 1756 | [BPF_S_ANC_ALU_XOR_X] = BPF_LD|BPF_B|BPF_ABS, |
Pavel Emelyanov | a8fc927 | 2012-11-01 02:01:48 +0000 | [diff] [blame] | 1757 | [BPF_S_ANC_VLAN_TAG] = BPF_LD|BPF_B|BPF_ABS, |
| 1758 | [BPF_S_ANC_VLAN_TAG_PRESENT] = BPF_LD|BPF_B|BPF_ABS, |
Daniel Borkmann | 3e5289d | 2013-03-19 06:39:31 +0000 | [diff] [blame] | 1759 | [BPF_S_ANC_PAY_OFFSET] = BPF_LD|BPF_B|BPF_ABS, |
Chema Gonzalez | 4cd3675 | 2014-04-21 09:21:24 -0700 | [diff] [blame] | 1760 | [BPF_S_ANC_RANDOM] = BPF_LD|BPF_B|BPF_ABS, |
Pavel Emelyanov | a8fc927 | 2012-11-01 02:01:48 +0000 | [diff] [blame] | 1761 | [BPF_S_LD_W_LEN] = BPF_LD|BPF_W|BPF_LEN, |
| 1762 | [BPF_S_LD_W_IND] = BPF_LD|BPF_W|BPF_IND, |
| 1763 | [BPF_S_LD_H_IND] = BPF_LD|BPF_H|BPF_IND, |
| 1764 | [BPF_S_LD_B_IND] = BPF_LD|BPF_B|BPF_IND, |
| 1765 | [BPF_S_LD_IMM] = BPF_LD|BPF_IMM, |
| 1766 | [BPF_S_LDX_W_LEN] = BPF_LDX|BPF_W|BPF_LEN, |
| 1767 | [BPF_S_LDX_B_MSH] = BPF_LDX|BPF_B|BPF_MSH, |
| 1768 | [BPF_S_LDX_IMM] = BPF_LDX|BPF_IMM, |
| 1769 | [BPF_S_MISC_TAX] = BPF_MISC|BPF_TAX, |
| 1770 | [BPF_S_MISC_TXA] = BPF_MISC|BPF_TXA, |
| 1771 | [BPF_S_RET_K] = BPF_RET|BPF_K, |
| 1772 | [BPF_S_RET_A] = BPF_RET|BPF_A, |
| 1773 | [BPF_S_ALU_DIV_K] = BPF_ALU|BPF_DIV|BPF_K, |
| 1774 | [BPF_S_LD_MEM] = BPF_LD|BPF_MEM, |
| 1775 | [BPF_S_LDX_MEM] = BPF_LDX|BPF_MEM, |
| 1776 | [BPF_S_ST] = BPF_ST, |
| 1777 | [BPF_S_STX] = BPF_STX, |
| 1778 | [BPF_S_JMP_JA] = BPF_JMP|BPF_JA, |
| 1779 | [BPF_S_JMP_JEQ_K] = BPF_JMP|BPF_JEQ|BPF_K, |
| 1780 | [BPF_S_JMP_JEQ_X] = BPF_JMP|BPF_JEQ|BPF_X, |
| 1781 | [BPF_S_JMP_JGE_K] = BPF_JMP|BPF_JGE|BPF_K, |
| 1782 | [BPF_S_JMP_JGE_X] = BPF_JMP|BPF_JGE|BPF_X, |
| 1783 | [BPF_S_JMP_JGT_K] = BPF_JMP|BPF_JGT|BPF_K, |
| 1784 | [BPF_S_JMP_JGT_X] = BPF_JMP|BPF_JGT|BPF_X, |
| 1785 | [BPF_S_JMP_JSET_K] = BPF_JMP|BPF_JSET|BPF_K, |
| 1786 | [BPF_S_JMP_JSET_X] = BPF_JMP|BPF_JSET|BPF_X, |
| 1787 | }; |
| 1788 | u16 code; |
| 1789 | |
| 1790 | code = filt->code; |
| 1791 | |
| 1792 | to->code = decodes[code]; |
| 1793 | to->jt = filt->jt; |
| 1794 | to->jf = filt->jf; |
Eric Dumazet | aee636c | 2014-01-15 06:50:07 -0800 | [diff] [blame] | 1795 | to->k = filt->k; |
Pavel Emelyanov | a8fc927 | 2012-11-01 02:01:48 +0000 | [diff] [blame] | 1796 | } |
| 1797 | |
Daniel Borkmann | a3ea269 | 2014-03-28 18:58:19 +0100 | [diff] [blame] | 1798 | int sk_get_filter(struct sock *sk, struct sock_filter __user *ubuf, |
| 1799 | unsigned int len) |
Pavel Emelyanov | a8fc927 | 2012-11-01 02:01:48 +0000 | [diff] [blame] | 1800 | { |
Daniel Borkmann | a3ea269 | 2014-03-28 18:58:19 +0100 | [diff] [blame] | 1801 | struct sock_fprog_kern *fprog; |
Pavel Emelyanov | a8fc927 | 2012-11-01 02:01:48 +0000 | [diff] [blame] | 1802 | struct sk_filter *filter; |
Daniel Borkmann | a3ea269 | 2014-03-28 18:58:19 +0100 | [diff] [blame] | 1803 | int ret = 0; |
Pavel Emelyanov | a8fc927 | 2012-11-01 02:01:48 +0000 | [diff] [blame] | 1804 | |
| 1805 | lock_sock(sk); |
| 1806 | filter = rcu_dereference_protected(sk->sk_filter, |
Daniel Borkmann | a3ea269 | 2014-03-28 18:58:19 +0100 | [diff] [blame] | 1807 | sock_owned_by_user(sk)); |
Pavel Emelyanov | a8fc927 | 2012-11-01 02:01:48 +0000 | [diff] [blame] | 1808 | if (!filter) |
| 1809 | goto out; |
Daniel Borkmann | a3ea269 | 2014-03-28 18:58:19 +0100 | [diff] [blame] | 1810 | |
| 1811 | /* We're copying the filter that has been originally attached, |
| 1812 | * so no conversion/decode needed anymore. |
| 1813 | */ |
| 1814 | fprog = filter->orig_prog; |
| 1815 | |
| 1816 | ret = fprog->len; |
Pavel Emelyanov | a8fc927 | 2012-11-01 02:01:48 +0000 | [diff] [blame] | 1817 | if (!len) |
Daniel Borkmann | a3ea269 | 2014-03-28 18:58:19 +0100 | [diff] [blame] | 1818 | /* User space only enquires number of filter blocks. */ |
Pavel Emelyanov | a8fc927 | 2012-11-01 02:01:48 +0000 | [diff] [blame] | 1819 | goto out; |
Daniel Borkmann | a3ea269 | 2014-03-28 18:58:19 +0100 | [diff] [blame] | 1820 | |
Pavel Emelyanov | a8fc927 | 2012-11-01 02:01:48 +0000 | [diff] [blame] | 1821 | ret = -EINVAL; |
Daniel Borkmann | a3ea269 | 2014-03-28 18:58:19 +0100 | [diff] [blame] | 1822 | if (len < fprog->len) |
Pavel Emelyanov | a8fc927 | 2012-11-01 02:01:48 +0000 | [diff] [blame] | 1823 | goto out; |
| 1824 | |
| 1825 | ret = -EFAULT; |
Daniel Borkmann | a3ea269 | 2014-03-28 18:58:19 +0100 | [diff] [blame] | 1826 | if (copy_to_user(ubuf, fprog->filter, sk_filter_proglen(fprog))) |
| 1827 | goto out; |
Pavel Emelyanov | a8fc927 | 2012-11-01 02:01:48 +0000 | [diff] [blame] | 1828 | |
Daniel Borkmann | a3ea269 | 2014-03-28 18:58:19 +0100 | [diff] [blame] | 1829 | /* Instead of bytes, the API requests to return the number |
| 1830 | * of filter blocks. |
| 1831 | */ |
| 1832 | ret = fprog->len; |
Pavel Emelyanov | a8fc927 | 2012-11-01 02:01:48 +0000 | [diff] [blame] | 1833 | out: |
| 1834 | release_sock(sk); |
| 1835 | return ret; |
| 1836 | } |