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 */ |
Alexei Starovoitov | e430f34 | 2014-06-06 14:46:06 -0700 | [diff] [blame] | 62 | #define DST regs[insn->dst_reg] |
| 63 | #define SRC regs[insn->src_reg] |
Daniel Borkmann | 3074383 | 2014-05-01 18:34:19 +0200 | [diff] [blame] | 64 | #define FP regs[BPF_REG_FP] |
| 65 | #define ARG1 regs[BPF_REG_ARG1] |
| 66 | #define CTX regs[BPF_REG_CTX] |
Alexei Starovoitov | e430f34 | 2014-06-06 14:46:06 -0700 | [diff] [blame] | 67 | #define IMM insn->imm |
Daniel Borkmann | 3074383 | 2014-05-01 18:34:19 +0200 | [diff] [blame] | 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 | |
Alexei Starovoitov | e430f34 | 2014-06-06 14:46:06 -0700 | [diff] [blame] | 267 | /* Registers used in classic BPF programs need to be reset first. */ |
Daniel Borkmann | 3074383 | 2014-05-01 18:34:19 +0200 | [diff] [blame] | 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 | e430f34 | 2014-06-06 14:46:06 -0700 | [diff] [blame] | 277 | DST = DST OP SRC; \ |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 278 | CONT; \ |
Daniel Borkmann | 5bcfedf | 2014-05-01 18:34:18 +0200 | [diff] [blame] | 279 | ALU_##OPCODE##_X: \ |
Alexei Starovoitov | e430f34 | 2014-06-06 14:46:06 -0700 | [diff] [blame] | 280 | DST = (u32) DST OP (u32) SRC; \ |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 281 | CONT; \ |
Daniel Borkmann | 5bcfedf | 2014-05-01 18:34:18 +0200 | [diff] [blame] | 282 | ALU64_##OPCODE##_K: \ |
Alexei Starovoitov | e430f34 | 2014-06-06 14:46:06 -0700 | [diff] [blame] | 283 | DST = DST OP IMM; \ |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 284 | CONT; \ |
Daniel Borkmann | 5bcfedf | 2014-05-01 18:34:18 +0200 | [diff] [blame] | 285 | ALU_##OPCODE##_K: \ |
Alexei Starovoitov | e430f34 | 2014-06-06 14:46:06 -0700 | [diff] [blame] | 286 | DST = (u32) DST OP (u32) IMM; \ |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 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 | e430f34 | 2014-06-06 14:46:06 -0700 | [diff] [blame] | 299 | DST = (u32) -DST; |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 300 | CONT; |
Daniel Borkmann | 8556ce7 | 2014-05-23 18:43:57 +0200 | [diff] [blame] | 301 | ALU64_NEG: |
Alexei Starovoitov | e430f34 | 2014-06-06 14:46:06 -0700 | [diff] [blame] | 302 | DST = -DST; |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 303 | CONT; |
Daniel Borkmann | 5bcfedf | 2014-05-01 18:34:18 +0200 | [diff] [blame] | 304 | ALU_MOV_X: |
Alexei Starovoitov | e430f34 | 2014-06-06 14:46:06 -0700 | [diff] [blame] | 305 | DST = (u32) SRC; |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 306 | CONT; |
Daniel Borkmann | 5bcfedf | 2014-05-01 18:34:18 +0200 | [diff] [blame] | 307 | ALU_MOV_K: |
Alexei Starovoitov | e430f34 | 2014-06-06 14:46:06 -0700 | [diff] [blame] | 308 | DST = (u32) IMM; |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 309 | CONT; |
Daniel Borkmann | 5bcfedf | 2014-05-01 18:34:18 +0200 | [diff] [blame] | 310 | ALU64_MOV_X: |
Alexei Starovoitov | e430f34 | 2014-06-06 14:46:06 -0700 | [diff] [blame] | 311 | DST = SRC; |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 312 | CONT; |
Daniel Borkmann | 5bcfedf | 2014-05-01 18:34:18 +0200 | [diff] [blame] | 313 | ALU64_MOV_K: |
Alexei Starovoitov | e430f34 | 2014-06-06 14:46:06 -0700 | [diff] [blame] | 314 | DST = IMM; |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 315 | CONT; |
Daniel Borkmann | 5bcfedf | 2014-05-01 18:34:18 +0200 | [diff] [blame] | 316 | ALU64_ARSH_X: |
Alexei Starovoitov | e430f34 | 2014-06-06 14:46:06 -0700 | [diff] [blame] | 317 | (*(s64 *) &DST) >>= SRC; |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 318 | CONT; |
Daniel Borkmann | 5bcfedf | 2014-05-01 18:34:18 +0200 | [diff] [blame] | 319 | ALU64_ARSH_K: |
Alexei Starovoitov | e430f34 | 2014-06-06 14:46:06 -0700 | [diff] [blame] | 320 | (*(s64 *) &DST) >>= IMM; |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 321 | CONT; |
Daniel Borkmann | 5bcfedf | 2014-05-01 18:34:18 +0200 | [diff] [blame] | 322 | ALU64_MOD_X: |
Alexei Starovoitov | e430f34 | 2014-06-06 14:46:06 -0700 | [diff] [blame] | 323 | if (unlikely(SRC == 0)) |
Daniel Borkmann | 5f9fde5 | 2014-04-05 01:04:03 +0200 | [diff] [blame] | 324 | return 0; |
Alexei Starovoitov | e430f34 | 2014-06-06 14:46:06 -0700 | [diff] [blame] | 325 | tmp = DST; |
| 326 | DST = do_div(tmp, SRC); |
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: |
Alexei Starovoitov | e430f34 | 2014-06-06 14:46:06 -0700 | [diff] [blame] | 329 | if (unlikely(SRC == 0)) |
Daniel Borkmann | 5f9fde5 | 2014-04-05 01:04:03 +0200 | [diff] [blame] | 330 | return 0; |
Alexei Starovoitov | e430f34 | 2014-06-06 14:46:06 -0700 | [diff] [blame] | 331 | tmp = (u32) DST; |
| 332 | DST = do_div(tmp, (u32) SRC); |
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 | e430f34 | 2014-06-06 14:46:06 -0700 | [diff] [blame] | 335 | tmp = DST; |
| 336 | DST = do_div(tmp, IMM); |
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 | e430f34 | 2014-06-06 14:46:06 -0700 | [diff] [blame] | 339 | tmp = (u32) DST; |
| 340 | DST = do_div(tmp, (u32) IMM); |
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: |
Alexei Starovoitov | e430f34 | 2014-06-06 14:46:06 -0700 | [diff] [blame] | 343 | if (unlikely(SRC == 0)) |
Daniel Borkmann | 5f9fde5 | 2014-04-05 01:04:03 +0200 | [diff] [blame] | 344 | return 0; |
Alexei Starovoitov | e430f34 | 2014-06-06 14:46:06 -0700 | [diff] [blame] | 345 | do_div(DST, SRC); |
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: |
Alexei Starovoitov | e430f34 | 2014-06-06 14:46:06 -0700 | [diff] [blame] | 348 | if (unlikely(SRC == 0)) |
Daniel Borkmann | 5f9fde5 | 2014-04-05 01:04:03 +0200 | [diff] [blame] | 349 | return 0; |
Alexei Starovoitov | e430f34 | 2014-06-06 14:46:06 -0700 | [diff] [blame] | 350 | tmp = (u32) DST; |
| 351 | do_div(tmp, (u32) SRC); |
| 352 | DST = (u32) tmp; |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 353 | CONT; |
Daniel Borkmann | 5bcfedf | 2014-05-01 18:34:18 +0200 | [diff] [blame] | 354 | ALU64_DIV_K: |
Alexei Starovoitov | e430f34 | 2014-06-06 14:46:06 -0700 | [diff] [blame] | 355 | do_div(DST, IMM); |
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 | e430f34 | 2014-06-06 14:46:06 -0700 | [diff] [blame] | 358 | tmp = (u32) DST; |
| 359 | do_div(tmp, (u32) IMM); |
| 360 | DST = (u32) tmp; |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 361 | CONT; |
Daniel Borkmann | 5bcfedf | 2014-05-01 18:34:18 +0200 | [diff] [blame] | 362 | ALU_END_TO_BE: |
Alexei Starovoitov | e430f34 | 2014-06-06 14:46:06 -0700 | [diff] [blame] | 363 | switch (IMM) { |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 364 | case 16: |
Alexei Starovoitov | e430f34 | 2014-06-06 14:46:06 -0700 | [diff] [blame] | 365 | DST = (__force u16) cpu_to_be16(DST); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 366 | break; |
| 367 | case 32: |
Alexei Starovoitov | e430f34 | 2014-06-06 14:46:06 -0700 | [diff] [blame] | 368 | DST = (__force u32) cpu_to_be32(DST); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 369 | break; |
| 370 | case 64: |
Alexei Starovoitov | e430f34 | 2014-06-06 14:46:06 -0700 | [diff] [blame] | 371 | DST = (__force u64) cpu_to_be64(DST); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 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 | e430f34 | 2014-06-06 14:46:06 -0700 | [diff] [blame] | 376 | switch (IMM) { |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 377 | case 16: |
Alexei Starovoitov | e430f34 | 2014-06-06 14:46:06 -0700 | [diff] [blame] | 378 | DST = (__force u16) cpu_to_le16(DST); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 379 | break; |
| 380 | case 32: |
Alexei Starovoitov | e430f34 | 2014-06-06 14:46:06 -0700 | [diff] [blame] | 381 | DST = (__force u32) cpu_to_le32(DST); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 382 | break; |
| 383 | case 64: |
Alexei Starovoitov | e430f34 | 2014-06-06 14:46:06 -0700 | [diff] [blame] | 384 | DST = (__force u64) cpu_to_le64(DST); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 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 | e430f34 | 2014-06-06 14:46:06 -0700 | [diff] [blame] | 404 | if (DST == SRC) { |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 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 | e430f34 | 2014-06-06 14:46:06 -0700 | [diff] [blame] | 410 | if (DST == IMM) { |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 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 | e430f34 | 2014-06-06 14:46:06 -0700 | [diff] [blame] | 416 | if (DST != SRC) { |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 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 | e430f34 | 2014-06-06 14:46:06 -0700 | [diff] [blame] | 422 | if (DST != IMM) { |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 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 | e430f34 | 2014-06-06 14:46:06 -0700 | [diff] [blame] | 428 | if (DST > SRC) { |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 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 | e430f34 | 2014-06-06 14:46:06 -0700 | [diff] [blame] | 434 | if (DST > IMM) { |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 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 | e430f34 | 2014-06-06 14:46:06 -0700 | [diff] [blame] | 440 | if (DST >= SRC) { |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 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 | e430f34 | 2014-06-06 14:46:06 -0700 | [diff] [blame] | 446 | if (DST >= IMM) { |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 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: |
Alexei Starovoitov | e430f34 | 2014-06-06 14:46:06 -0700 | [diff] [blame] | 452 | if (((s64) DST) > ((s64) SRC)) { |
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: |
Alexei Starovoitov | e430f34 | 2014-06-06 14:46:06 -0700 | [diff] [blame] | 458 | if (((s64) DST) > ((s64) IMM)) { |
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: |
Alexei Starovoitov | e430f34 | 2014-06-06 14:46:06 -0700 | [diff] [blame] | 464 | if (((s64) DST) >= ((s64) SRC)) { |
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: |
Alexei Starovoitov | e430f34 | 2014-06-06 14:46:06 -0700 | [diff] [blame] | 470 | if (((s64) DST) >= ((s64) IMM)) { |
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 | e430f34 | 2014-06-06 14:46:06 -0700 | [diff] [blame] | 476 | if (DST & SRC) { |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 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 | e430f34 | 2014-06-06 14:46:06 -0700 | [diff] [blame] | 482 | if (DST & IMM) { |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 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*/ |
Alexei Starovoitov | e430f34 | 2014-06-06 14:46:06 -0700 | [diff] [blame] | 491 | #define LDST(SIZEOP, SIZE) \ |
| 492 | STX_MEM_##SIZEOP: \ |
| 493 | *(SIZE *)(unsigned long) (DST + insn->off) = SRC; \ |
| 494 | CONT; \ |
| 495 | ST_MEM_##SIZEOP: \ |
| 496 | *(SIZE *)(unsigned long) (DST + insn->off) = IMM; \ |
| 497 | CONT; \ |
| 498 | LDX_MEM_##SIZEOP: \ |
| 499 | DST = *(SIZE *)(unsigned long) (SRC + insn->off); \ |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 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 |
Alexei Starovoitov | e430f34 | 2014-06-06 14:46:06 -0700 | [diff] [blame] | 507 | STX_XADD_W: /* lock xadd *(u32 *)(dst_reg + off16) += src_reg */ |
| 508 | atomic_add((u32) SRC, (atomic_t *)(unsigned long) |
| 509 | (DST + insn->off)); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 510 | CONT; |
Alexei Starovoitov | e430f34 | 2014-06-06 14:46:06 -0700 | [diff] [blame] | 511 | STX_XADD_DW: /* lock xadd *(u64 *)(dst_reg + off16) += src_reg */ |
| 512 | atomic64_add((u64) SRC, (atomic64_t *)(unsigned long) |
| 513 | (DST + insn->off)); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 514 | CONT; |
Alexei Starovoitov | e430f34 | 2014-06-06 14:46:06 -0700 | [diff] [blame] | 515 | LD_ABS_W: /* BPF_R0 = ntohl(*(u32 *) (skb->data + imm32)) */ |
| 516 | off = IMM; |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 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: |
Alexei Starovoitov | e430f34 | 2014-06-06 14:46:06 -0700 | [diff] [blame] | 530 | * ctx == skb == BPF_R6 == CTX |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 531 | * |
| 532 | * Explicit input: |
Alexei Starovoitov | e430f34 | 2014-06-06 14:46:06 -0700 | [diff] [blame] | 533 | * SRC == any register |
| 534 | * IMM == 32-bit immediate |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 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 | */ |
Daniel Borkmann | 3480593 | 2014-05-29 10:22:50 +0200 | [diff] [blame] | 539 | |
Alexei Starovoitov | 61f83d0 | 2014-06-11 13:16:44 -0700 | [diff] [blame] | 540 | ptr = load_pointer((struct sk_buff *) (unsigned long) CTX, off, 4, &tmp); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 541 | if (likely(ptr != NULL)) { |
David S. Miller | 1268e25 | 2014-05-13 13:13:33 -0400 | [diff] [blame] | 542 | BPF_R0 = get_unaligned_be32(ptr); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 543 | CONT; |
| 544 | } |
Daniel Borkmann | 3480593 | 2014-05-29 10:22:50 +0200 | [diff] [blame] | 545 | |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 546 | return 0; |
Alexei Starovoitov | e430f34 | 2014-06-06 14:46:06 -0700 | [diff] [blame] | 547 | LD_ABS_H: /* BPF_R0 = ntohs(*(u16 *) (skb->data + imm32)) */ |
| 548 | off = IMM; |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 549 | load_half: |
Alexei Starovoitov | 61f83d0 | 2014-06-11 13:16:44 -0700 | [diff] [blame] | 550 | ptr = load_pointer((struct sk_buff *) (unsigned long) CTX, off, 2, &tmp); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 551 | if (likely(ptr != NULL)) { |
David S. Miller | 1268e25 | 2014-05-13 13:13:33 -0400 | [diff] [blame] | 552 | BPF_R0 = get_unaligned_be16(ptr); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 553 | CONT; |
| 554 | } |
Daniel Borkmann | 3480593 | 2014-05-29 10:22:50 +0200 | [diff] [blame] | 555 | |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 556 | return 0; |
Alexei Starovoitov | e430f34 | 2014-06-06 14:46:06 -0700 | [diff] [blame] | 557 | LD_ABS_B: /* BPF_R0 = *(u8 *) (skb->data + imm32) */ |
| 558 | off = IMM; |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 559 | load_byte: |
Alexei Starovoitov | 61f83d0 | 2014-06-11 13:16:44 -0700 | [diff] [blame] | 560 | ptr = load_pointer((struct sk_buff *) (unsigned long) CTX, off, 1, &tmp); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 561 | if (likely(ptr != NULL)) { |
David S. Miller | 1268e25 | 2014-05-13 13:13:33 -0400 | [diff] [blame] | 562 | BPF_R0 = *(u8 *)ptr; |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 563 | CONT; |
| 564 | } |
Daniel Borkmann | 3480593 | 2014-05-29 10:22:50 +0200 | [diff] [blame] | 565 | |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 566 | return 0; |
Alexei Starovoitov | e430f34 | 2014-06-06 14:46:06 -0700 | [diff] [blame] | 567 | LD_IND_W: /* BPF_R0 = ntohl(*(u32 *) (skb->data + src_reg + imm32)) */ |
| 568 | off = IMM + SRC; |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 569 | goto load_word; |
Alexei Starovoitov | e430f34 | 2014-06-06 14:46:06 -0700 | [diff] [blame] | 570 | LD_IND_H: /* BPF_R0 = ntohs(*(u16 *) (skb->data + src_reg + imm32)) */ |
| 571 | off = IMM + SRC; |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 572 | goto load_half; |
Alexei Starovoitov | e430f34 | 2014-06-06 14:46:06 -0700 | [diff] [blame] | 573 | LD_IND_B: /* BPF_R0 = *(u8 *) (skb->data + src_reg + imm32) */ |
| 574 | off = IMM + SRC; |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 575 | goto load_byte; |
| 576 | |
| 577 | default_label: |
| 578 | /* If we ever reach this, we have a bug somewhere. */ |
| 579 | WARN_RATELIMIT(1, "unknown opcode %02x\n", insn->code); |
| 580 | return 0; |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 581 | } |
| 582 | |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 583 | /* Helper to find the offset of pkt_type in sk_buff structure. We want |
| 584 | * to make sure its still a 3bit field starting at a byte boundary; |
| 585 | * taken from arch/x86/net/bpf_jit_comp.c. |
| 586 | */ |
Alexei Starovoitov | 0dcceab | 2014-06-05 14:39:36 -0700 | [diff] [blame] | 587 | #ifdef __BIG_ENDIAN_BITFIELD |
| 588 | #define PKT_TYPE_MAX (7 << 5) |
| 589 | #else |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 590 | #define PKT_TYPE_MAX 7 |
Alexei Starovoitov | 0dcceab | 2014-06-05 14:39:36 -0700 | [diff] [blame] | 591 | #endif |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 592 | static unsigned int pkt_type_offset(void) |
| 593 | { |
| 594 | struct sk_buff skb_probe = { .pkt_type = ~0, }; |
| 595 | u8 *ct = (u8 *) &skb_probe; |
| 596 | unsigned int off; |
| 597 | |
| 598 | for (off = 0; off < sizeof(struct sk_buff); off++) { |
| 599 | if (ct[off] == PKT_TYPE_MAX) |
| 600 | return off; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 601 | } |
| 602 | |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 603 | pr_err_once("Please fix %s, as pkt_type couldn't be found!\n", __func__); |
| 604 | return -1; |
| 605 | } |
| 606 | |
Daniel Borkmann | 3074383 | 2014-05-01 18:34:19 +0200 | [diff] [blame] | 607 | 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] | 608 | { |
Daniel Borkmann | eb9672f | 2014-05-01 18:34:20 +0200 | [diff] [blame] | 609 | return __skb_get_poff((struct sk_buff *)(unsigned long) ctx); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 610 | } |
| 611 | |
Daniel Borkmann | 3074383 | 2014-05-01 18:34:19 +0200 | [diff] [blame] | 612 | 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] | 613 | { |
Daniel Borkmann | eb9672f | 2014-05-01 18:34:20 +0200 | [diff] [blame] | 614 | struct sk_buff *skb = (struct sk_buff *)(unsigned long) ctx; |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 615 | struct nlattr *nla; |
| 616 | |
| 617 | if (skb_is_nonlinear(skb)) |
| 618 | return 0; |
| 619 | |
Mathias Krause | 05ab8f2 | 2014-04-13 18:23:33 +0200 | [diff] [blame] | 620 | if (skb->len < sizeof(struct nlattr)) |
| 621 | return 0; |
| 622 | |
Daniel Borkmann | 3074383 | 2014-05-01 18:34:19 +0200 | [diff] [blame] | 623 | if (a > skb->len - sizeof(struct nlattr)) |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 624 | return 0; |
| 625 | |
Daniel Borkmann | 3074383 | 2014-05-01 18:34:19 +0200 | [diff] [blame] | 626 | nla = nla_find((struct nlattr *) &skb->data[a], skb->len - a, x); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 627 | if (nla) |
| 628 | return (void *) nla - (void *) skb->data; |
| 629 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 630 | return 0; |
| 631 | } |
| 632 | |
Daniel Borkmann | 3074383 | 2014-05-01 18:34:19 +0200 | [diff] [blame] | 633 | 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] | 634 | { |
Daniel Borkmann | eb9672f | 2014-05-01 18:34:20 +0200 | [diff] [blame] | 635 | struct sk_buff *skb = (struct sk_buff *)(unsigned long) ctx; |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 636 | struct nlattr *nla; |
| 637 | |
| 638 | if (skb_is_nonlinear(skb)) |
| 639 | return 0; |
| 640 | |
Mathias Krause | 05ab8f2 | 2014-04-13 18:23:33 +0200 | [diff] [blame] | 641 | if (skb->len < sizeof(struct nlattr)) |
| 642 | return 0; |
| 643 | |
Daniel Borkmann | 3074383 | 2014-05-01 18:34:19 +0200 | [diff] [blame] | 644 | if (a > skb->len - sizeof(struct nlattr)) |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 645 | return 0; |
| 646 | |
Daniel Borkmann | 3074383 | 2014-05-01 18:34:19 +0200 | [diff] [blame] | 647 | nla = (struct nlattr *) &skb->data[a]; |
| 648 | if (nla->nla_len > skb->len - a) |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 649 | return 0; |
| 650 | |
Daniel Borkmann | 3074383 | 2014-05-01 18:34:19 +0200 | [diff] [blame] | 651 | nla = nla_find_nested(nla, x); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 652 | if (nla) |
| 653 | return (void *) nla - (void *) skb->data; |
| 654 | |
| 655 | return 0; |
| 656 | } |
| 657 | |
Daniel Borkmann | 3074383 | 2014-05-01 18:34:19 +0200 | [diff] [blame] | 658 | 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] | 659 | { |
| 660 | return raw_smp_processor_id(); |
| 661 | } |
| 662 | |
Chema Gonzalez | 4cd3675 | 2014-04-21 09:21:24 -0700 | [diff] [blame] | 663 | /* note that this only generates 32-bit random numbers */ |
Daniel Borkmann | 3074383 | 2014-05-01 18:34:19 +0200 | [diff] [blame] | 664 | 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] | 665 | { |
Daniel Borkmann | eb9672f | 2014-05-01 18:34:20 +0200 | [diff] [blame] | 666 | return prandom_u32(); |
Chema Gonzalez | 4cd3675 | 2014-04-21 09:21:24 -0700 | [diff] [blame] | 667 | } |
| 668 | |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 669 | static bool convert_bpf_extensions(struct sock_filter *fp, |
| 670 | struct sock_filter_int **insnp) |
| 671 | { |
| 672 | struct sock_filter_int *insn = *insnp; |
| 673 | |
| 674 | switch (fp->k) { |
| 675 | case SKF_AD_OFF + SKF_AD_PROTOCOL: |
| 676 | BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, protocol) != 2); |
| 677 | |
Alexei Starovoitov | e430f34 | 2014-06-06 14:46:06 -0700 | [diff] [blame] | 678 | /* A = *(u16 *) (CTX + offsetof(protocol)) */ |
Daniel Borkmann | f8f6d67 | 2014-05-29 10:22:51 +0200 | [diff] [blame] | 679 | *insn++ = BPF_LDX_MEM(BPF_H, BPF_REG_A, BPF_REG_CTX, |
| 680 | offsetof(struct sk_buff, protocol)); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 681 | /* A = ntohs(A) [emitting a nop or swap16] */ |
Daniel Borkmann | f8f6d67 | 2014-05-29 10:22:51 +0200 | [diff] [blame] | 682 | *insn = BPF_ENDIAN(BPF_FROM_BE, BPF_REG_A, 16); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 683 | break; |
| 684 | |
| 685 | case SKF_AD_OFF + SKF_AD_PKTTYPE: |
Alexei Starovoitov | 9739eef | 2014-05-08 14:10:51 -0700 | [diff] [blame] | 686 | *insn = BPF_LDX_MEM(BPF_B, BPF_REG_A, BPF_REG_CTX, |
| 687 | pkt_type_offset()); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 688 | if (insn->off < 0) |
| 689 | return false; |
| 690 | insn++; |
Alexei Starovoitov | 9739eef | 2014-05-08 14:10:51 -0700 | [diff] [blame] | 691 | *insn = BPF_ALU32_IMM(BPF_AND, BPF_REG_A, PKT_TYPE_MAX); |
Alexei Starovoitov | 0dcceab | 2014-06-05 14:39:36 -0700 | [diff] [blame] | 692 | #ifdef __BIG_ENDIAN_BITFIELD |
| 693 | insn++; |
David S. Miller | f666f87 | 2014-06-05 16:22:02 -0700 | [diff] [blame] | 694 | *insn = BPF_ALU32_IMM(BPF_RSH, BPF_REG_A, 5); |
Alexei Starovoitov | 0dcceab | 2014-06-05 14:39:36 -0700 | [diff] [blame] | 695 | #endif |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 696 | break; |
| 697 | |
| 698 | case SKF_AD_OFF + SKF_AD_IFINDEX: |
| 699 | case SKF_AD_OFF + SKF_AD_HATYPE: |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 700 | BUILD_BUG_ON(FIELD_SIZEOF(struct net_device, ifindex) != 4); |
| 701 | BUILD_BUG_ON(FIELD_SIZEOF(struct net_device, type) != 2); |
Daniel Borkmann | f8f6d67 | 2014-05-29 10:22:51 +0200 | [diff] [blame] | 702 | BUILD_BUG_ON(bytes_to_bpf_size(FIELD_SIZEOF(struct sk_buff, dev)) < 0); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 703 | |
Daniel Borkmann | f8f6d67 | 2014-05-29 10:22:51 +0200 | [diff] [blame] | 704 | *insn++ = BPF_LDX_MEM(bytes_to_bpf_size(FIELD_SIZEOF(struct sk_buff, dev)), |
| 705 | BPF_REG_TMP, BPF_REG_CTX, |
| 706 | offsetof(struct sk_buff, dev)); |
| 707 | /* if (tmp != 0) goto pc + 1 */ |
| 708 | *insn++ = BPF_JMP_IMM(BPF_JNE, BPF_REG_TMP, 0, 1); |
| 709 | *insn++ = BPF_EXIT_INSN(); |
| 710 | if (fp->k == SKF_AD_OFF + SKF_AD_IFINDEX) |
| 711 | *insn = BPF_LDX_MEM(BPF_W, BPF_REG_A, BPF_REG_TMP, |
| 712 | offsetof(struct net_device, ifindex)); |
| 713 | else |
| 714 | *insn = BPF_LDX_MEM(BPF_H, BPF_REG_A, BPF_REG_TMP, |
| 715 | offsetof(struct net_device, type)); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 716 | break; |
| 717 | |
| 718 | case SKF_AD_OFF + SKF_AD_MARK: |
| 719 | BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, mark) != 4); |
| 720 | |
Alexei Starovoitov | 9739eef | 2014-05-08 14:10:51 -0700 | [diff] [blame] | 721 | *insn = BPF_LDX_MEM(BPF_W, BPF_REG_A, BPF_REG_CTX, |
| 722 | offsetof(struct sk_buff, mark)); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 723 | break; |
| 724 | |
| 725 | case SKF_AD_OFF + SKF_AD_RXHASH: |
| 726 | BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, hash) != 4); |
| 727 | |
Alexei Starovoitov | 9739eef | 2014-05-08 14:10:51 -0700 | [diff] [blame] | 728 | *insn = BPF_LDX_MEM(BPF_W, BPF_REG_A, BPF_REG_CTX, |
| 729 | offsetof(struct sk_buff, hash)); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 730 | break; |
| 731 | |
| 732 | case SKF_AD_OFF + SKF_AD_QUEUE: |
| 733 | BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, queue_mapping) != 2); |
| 734 | |
Alexei Starovoitov | 9739eef | 2014-05-08 14:10:51 -0700 | [diff] [blame] | 735 | *insn = BPF_LDX_MEM(BPF_H, BPF_REG_A, BPF_REG_CTX, |
| 736 | offsetof(struct sk_buff, queue_mapping)); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 737 | break; |
| 738 | |
| 739 | case SKF_AD_OFF + SKF_AD_VLAN_TAG: |
| 740 | case SKF_AD_OFF + SKF_AD_VLAN_TAG_PRESENT: |
| 741 | BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, vlan_tci) != 2); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 742 | BUILD_BUG_ON(VLAN_TAG_PRESENT != 0x1000); |
| 743 | |
Alexei Starovoitov | e430f34 | 2014-06-06 14:46:06 -0700 | [diff] [blame] | 744 | /* A = *(u16 *) (CTX + offsetof(vlan_tci)) */ |
Daniel Borkmann | f8f6d67 | 2014-05-29 10:22:51 +0200 | [diff] [blame] | 745 | *insn++ = BPF_LDX_MEM(BPF_H, BPF_REG_A, BPF_REG_CTX, |
| 746 | offsetof(struct sk_buff, vlan_tci)); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 747 | if (fp->k == SKF_AD_OFF + SKF_AD_VLAN_TAG) { |
Alexei Starovoitov | 9739eef | 2014-05-08 14:10:51 -0700 | [diff] [blame] | 748 | *insn = BPF_ALU32_IMM(BPF_AND, BPF_REG_A, |
| 749 | ~VLAN_TAG_PRESENT); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 750 | } else { |
Alexei Starovoitov | 9739eef | 2014-05-08 14:10:51 -0700 | [diff] [blame] | 751 | /* A >>= 12 */ |
Daniel Borkmann | f8f6d67 | 2014-05-29 10:22:51 +0200 | [diff] [blame] | 752 | *insn++ = BPF_ALU32_IMM(BPF_RSH, BPF_REG_A, 12); |
Alexei Starovoitov | 9739eef | 2014-05-08 14:10:51 -0700 | [diff] [blame] | 753 | /* A &= 1 */ |
| 754 | *insn = BPF_ALU32_IMM(BPF_AND, BPF_REG_A, 1); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 755 | } |
| 756 | break; |
| 757 | |
| 758 | case SKF_AD_OFF + SKF_AD_PAY_OFFSET: |
| 759 | case SKF_AD_OFF + SKF_AD_NLATTR: |
| 760 | case SKF_AD_OFF + SKF_AD_NLATTR_NEST: |
| 761 | case SKF_AD_OFF + SKF_AD_CPU: |
Chema Gonzalez | 4cd3675 | 2014-04-21 09:21:24 -0700 | [diff] [blame] | 762 | case SKF_AD_OFF + SKF_AD_RANDOM: |
Alexei Starovoitov | e430f34 | 2014-06-06 14:46:06 -0700 | [diff] [blame] | 763 | /* arg1 = CTX */ |
Daniel Borkmann | f8f6d67 | 2014-05-29 10:22:51 +0200 | [diff] [blame] | 764 | *insn++ = BPF_MOV64_REG(BPF_REG_ARG1, BPF_REG_CTX); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 765 | /* arg2 = A */ |
Daniel Borkmann | f8f6d67 | 2014-05-29 10:22:51 +0200 | [diff] [blame] | 766 | *insn++ = BPF_MOV64_REG(BPF_REG_ARG2, BPF_REG_A); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 767 | /* arg3 = X */ |
Daniel Borkmann | f8f6d67 | 2014-05-29 10:22:51 +0200 | [diff] [blame] | 768 | *insn++ = BPF_MOV64_REG(BPF_REG_ARG3, BPF_REG_X); |
Alexei Starovoitov | e430f34 | 2014-06-06 14:46:06 -0700 | [diff] [blame] | 769 | /* Emit call(arg1=CTX, arg2=A, arg3=X) */ |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 770 | switch (fp->k) { |
| 771 | case SKF_AD_OFF + SKF_AD_PAY_OFFSET: |
Daniel Borkmann | f8f6d67 | 2014-05-29 10:22:51 +0200 | [diff] [blame] | 772 | *insn = BPF_EMIT_CALL(__skb_get_pay_offset); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 773 | break; |
| 774 | case SKF_AD_OFF + SKF_AD_NLATTR: |
Daniel Borkmann | f8f6d67 | 2014-05-29 10:22:51 +0200 | [diff] [blame] | 775 | *insn = BPF_EMIT_CALL(__skb_get_nlattr); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 776 | break; |
| 777 | case SKF_AD_OFF + SKF_AD_NLATTR_NEST: |
Daniel Borkmann | f8f6d67 | 2014-05-29 10:22:51 +0200 | [diff] [blame] | 778 | *insn = BPF_EMIT_CALL(__skb_get_nlattr_nest); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 779 | break; |
| 780 | case SKF_AD_OFF + SKF_AD_CPU: |
Daniel Borkmann | f8f6d67 | 2014-05-29 10:22:51 +0200 | [diff] [blame] | 781 | *insn = BPF_EMIT_CALL(__get_raw_cpu_id); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 782 | break; |
Chema Gonzalez | 4cd3675 | 2014-04-21 09:21:24 -0700 | [diff] [blame] | 783 | case SKF_AD_OFF + SKF_AD_RANDOM: |
Daniel Borkmann | f8f6d67 | 2014-05-29 10:22:51 +0200 | [diff] [blame] | 784 | *insn = BPF_EMIT_CALL(__get_random_u32); |
Chema Gonzalez | 4cd3675 | 2014-04-21 09:21:24 -0700 | [diff] [blame] | 785 | break; |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 786 | } |
| 787 | break; |
| 788 | |
| 789 | case SKF_AD_OFF + SKF_AD_ALU_XOR_X: |
Alexei Starovoitov | 9739eef | 2014-05-08 14:10:51 -0700 | [diff] [blame] | 790 | /* A ^= X */ |
| 791 | *insn = BPF_ALU32_REG(BPF_XOR, BPF_REG_A, BPF_REG_X); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 792 | break; |
| 793 | |
| 794 | default: |
| 795 | /* This is just a dummy call to avoid letting the compiler |
| 796 | * evict __bpf_call_base() as an optimization. Placed here |
| 797 | * where no-one bothers. |
| 798 | */ |
| 799 | BUG_ON(__bpf_call_base(0, 0, 0, 0, 0) != 0); |
| 800 | return false; |
| 801 | } |
| 802 | |
| 803 | *insnp = insn; |
| 804 | return true; |
| 805 | } |
| 806 | |
| 807 | /** |
| 808 | * sk_convert_filter - convert filter program |
| 809 | * @prog: the user passed filter program |
| 810 | * @len: the length of the user passed filter program |
| 811 | * @new_prog: buffer where converted program will be stored |
| 812 | * @new_len: pointer to store length of converted program |
| 813 | * |
| 814 | * Remap 'sock_filter' style BPF instruction set to 'sock_filter_ext' style. |
| 815 | * Conversion workflow: |
| 816 | * |
| 817 | * 1) First pass for calculating the new program length: |
| 818 | * sk_convert_filter(old_prog, old_len, NULL, &new_len) |
| 819 | * |
| 820 | * 2) 2nd pass to remap in two passes: 1st pass finds new |
| 821 | * jump offsets, 2nd pass remapping: |
| 822 | * new_prog = kmalloc(sizeof(struct sock_filter_int) * new_len); |
| 823 | * sk_convert_filter(old_prog, old_len, new_prog, &new_len); |
| 824 | * |
| 825 | * User BPF's register A is mapped to our BPF register 6, user BPF |
| 826 | * register X is mapped to BPF register 7; frame pointer is always |
| 827 | * register 10; Context 'void *ctx' is stored in register 1, that is, |
| 828 | * for socket filters: ctx == 'struct sk_buff *', for seccomp: |
| 829 | * ctx == 'struct seccomp_data *'. |
| 830 | */ |
| 831 | int sk_convert_filter(struct sock_filter *prog, int len, |
| 832 | struct sock_filter_int *new_prog, int *new_len) |
| 833 | { |
| 834 | int new_flen = 0, pass = 0, target, i; |
| 835 | struct sock_filter_int *new_insn; |
| 836 | struct sock_filter *fp; |
| 837 | int *addrs = NULL; |
| 838 | u8 bpf_src; |
| 839 | |
| 840 | BUILD_BUG_ON(BPF_MEMWORDS * sizeof(u32) > MAX_BPF_STACK); |
Daniel Borkmann | 3074383 | 2014-05-01 18:34:19 +0200 | [diff] [blame] | 841 | BUILD_BUG_ON(BPF_REG_FP + 1 != MAX_BPF_REG); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 842 | |
Kees Cook | 6f9a093 | 2014-06-18 15:34:57 -0700 | [diff] [blame] | 843 | if (len <= 0 || len > BPF_MAXINSNS) |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 844 | return -EINVAL; |
| 845 | |
| 846 | if (new_prog) { |
Tobias Klauser | 99e72a0 | 2014-06-24 15:33:22 +0200 | [diff] [blame] | 847 | addrs = kcalloc(len, sizeof(*addrs), GFP_KERNEL); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 848 | if (!addrs) |
| 849 | return -ENOMEM; |
| 850 | } |
| 851 | |
| 852 | do_pass: |
| 853 | new_insn = new_prog; |
| 854 | fp = prog; |
| 855 | |
Daniel Borkmann | f8f6d67 | 2014-05-29 10:22:51 +0200 | [diff] [blame] | 856 | if (new_insn) |
| 857 | *new_insn = BPF_MOV64_REG(BPF_REG_CTX, BPF_REG_ARG1); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 858 | new_insn++; |
| 859 | |
| 860 | for (i = 0; i < len; fp++, i++) { |
| 861 | struct sock_filter_int tmp_insns[6] = { }; |
| 862 | struct sock_filter_int *insn = tmp_insns; |
| 863 | |
| 864 | if (addrs) |
| 865 | addrs[i] = new_insn - new_prog; |
| 866 | |
| 867 | switch (fp->code) { |
| 868 | /* All arithmetic insns and skb loads map as-is. */ |
| 869 | case BPF_ALU | BPF_ADD | BPF_X: |
| 870 | case BPF_ALU | BPF_ADD | BPF_K: |
| 871 | case BPF_ALU | BPF_SUB | BPF_X: |
| 872 | case BPF_ALU | BPF_SUB | BPF_K: |
| 873 | case BPF_ALU | BPF_AND | BPF_X: |
| 874 | case BPF_ALU | BPF_AND | BPF_K: |
| 875 | case BPF_ALU | BPF_OR | BPF_X: |
| 876 | case BPF_ALU | BPF_OR | BPF_K: |
| 877 | case BPF_ALU | BPF_LSH | BPF_X: |
| 878 | case BPF_ALU | BPF_LSH | BPF_K: |
| 879 | case BPF_ALU | BPF_RSH | BPF_X: |
| 880 | case BPF_ALU | BPF_RSH | BPF_K: |
| 881 | case BPF_ALU | BPF_XOR | BPF_X: |
| 882 | case BPF_ALU | BPF_XOR | BPF_K: |
| 883 | case BPF_ALU | BPF_MUL | BPF_X: |
| 884 | case BPF_ALU | BPF_MUL | BPF_K: |
| 885 | case BPF_ALU | BPF_DIV | BPF_X: |
| 886 | case BPF_ALU | BPF_DIV | BPF_K: |
| 887 | case BPF_ALU | BPF_MOD | BPF_X: |
| 888 | case BPF_ALU | BPF_MOD | BPF_K: |
| 889 | case BPF_ALU | BPF_NEG: |
| 890 | case BPF_LD | BPF_ABS | BPF_W: |
| 891 | case BPF_LD | BPF_ABS | BPF_H: |
| 892 | case BPF_LD | BPF_ABS | BPF_B: |
| 893 | case BPF_LD | BPF_IND | BPF_W: |
| 894 | case BPF_LD | BPF_IND | BPF_H: |
| 895 | case BPF_LD | BPF_IND | BPF_B: |
| 896 | /* Check for overloaded BPF extension and |
| 897 | * directly convert it if found, otherwise |
| 898 | * just move on with mapping. |
| 899 | */ |
| 900 | if (BPF_CLASS(fp->code) == BPF_LD && |
| 901 | BPF_MODE(fp->code) == BPF_ABS && |
| 902 | convert_bpf_extensions(fp, &insn)) |
| 903 | break; |
| 904 | |
Daniel Borkmann | f8f6d67 | 2014-05-29 10:22:51 +0200 | [diff] [blame] | 905 | *insn = BPF_RAW_INSN(fp->code, BPF_REG_A, BPF_REG_X, 0, fp->k); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 906 | break; |
| 907 | |
Daniel Borkmann | f8f6d67 | 2014-05-29 10:22:51 +0200 | [diff] [blame] | 908 | /* Jump transformation cannot use BPF block macros |
| 909 | * everywhere as offset calculation and target updates |
| 910 | * require a bit more work than the rest, i.e. jump |
| 911 | * opcodes map as-is, but offsets need adjustment. |
| 912 | */ |
| 913 | |
| 914 | #define BPF_EMIT_JMP \ |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 915 | do { \ |
| 916 | if (target >= len || target < 0) \ |
| 917 | goto err; \ |
| 918 | insn->off = addrs ? addrs[target] - addrs[i] - 1 : 0; \ |
| 919 | /* Adjust pc relative offset for 2nd or 3rd insn. */ \ |
| 920 | insn->off -= insn - tmp_insns; \ |
| 921 | } while (0) |
| 922 | |
Daniel Borkmann | f8f6d67 | 2014-05-29 10:22:51 +0200 | [diff] [blame] | 923 | case BPF_JMP | BPF_JA: |
| 924 | target = i + fp->k + 1; |
| 925 | insn->code = fp->code; |
| 926 | BPF_EMIT_JMP; |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 927 | break; |
| 928 | |
| 929 | case BPF_JMP | BPF_JEQ | BPF_K: |
| 930 | case BPF_JMP | BPF_JEQ | BPF_X: |
| 931 | case BPF_JMP | BPF_JSET | BPF_K: |
| 932 | case BPF_JMP | BPF_JSET | BPF_X: |
| 933 | case BPF_JMP | BPF_JGT | BPF_K: |
| 934 | case BPF_JMP | BPF_JGT | BPF_X: |
| 935 | case BPF_JMP | BPF_JGE | BPF_K: |
| 936 | case BPF_JMP | BPF_JGE | BPF_X: |
| 937 | if (BPF_SRC(fp->code) == BPF_K && (int) fp->k < 0) { |
| 938 | /* BPF immediates are signed, zero extend |
| 939 | * immediate into tmp register and use it |
| 940 | * in compare insn. |
| 941 | */ |
Daniel Borkmann | f8f6d67 | 2014-05-29 10:22:51 +0200 | [diff] [blame] | 942 | *insn++ = BPF_MOV32_IMM(BPF_REG_TMP, fp->k); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 943 | |
Alexei Starovoitov | e430f34 | 2014-06-06 14:46:06 -0700 | [diff] [blame] | 944 | insn->dst_reg = BPF_REG_A; |
| 945 | insn->src_reg = BPF_REG_TMP; |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 946 | bpf_src = BPF_X; |
| 947 | } else { |
Alexei Starovoitov | e430f34 | 2014-06-06 14:46:06 -0700 | [diff] [blame] | 948 | insn->dst_reg = BPF_REG_A; |
| 949 | insn->src_reg = BPF_REG_X; |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 950 | insn->imm = fp->k; |
| 951 | bpf_src = BPF_SRC(fp->code); |
| 952 | } |
| 953 | |
| 954 | /* Common case where 'jump_false' is next insn. */ |
| 955 | if (fp->jf == 0) { |
| 956 | insn->code = BPF_JMP | BPF_OP(fp->code) | bpf_src; |
| 957 | target = i + fp->jt + 1; |
Daniel Borkmann | f8f6d67 | 2014-05-29 10:22:51 +0200 | [diff] [blame] | 958 | BPF_EMIT_JMP; |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 959 | break; |
| 960 | } |
| 961 | |
| 962 | /* Convert JEQ into JNE when 'jump_true' is next insn. */ |
| 963 | if (fp->jt == 0 && BPF_OP(fp->code) == BPF_JEQ) { |
| 964 | insn->code = BPF_JMP | BPF_JNE | bpf_src; |
| 965 | target = i + fp->jf + 1; |
Daniel Borkmann | f8f6d67 | 2014-05-29 10:22:51 +0200 | [diff] [blame] | 966 | BPF_EMIT_JMP; |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 967 | break; |
| 968 | } |
| 969 | |
| 970 | /* Other jumps are mapped into two insns: Jxx and JA. */ |
| 971 | target = i + fp->jt + 1; |
| 972 | insn->code = BPF_JMP | BPF_OP(fp->code) | bpf_src; |
Daniel Borkmann | f8f6d67 | 2014-05-29 10:22:51 +0200 | [diff] [blame] | 973 | BPF_EMIT_JMP; |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 974 | insn++; |
| 975 | |
| 976 | insn->code = BPF_JMP | BPF_JA; |
| 977 | target = i + fp->jf + 1; |
Daniel Borkmann | f8f6d67 | 2014-05-29 10:22:51 +0200 | [diff] [blame] | 978 | BPF_EMIT_JMP; |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 979 | break; |
| 980 | |
| 981 | /* ldxb 4 * ([14] & 0xf) is remaped into 6 insns. */ |
| 982 | case BPF_LDX | BPF_MSH | BPF_B: |
Alexei Starovoitov | 9739eef | 2014-05-08 14:10:51 -0700 | [diff] [blame] | 983 | /* tmp = A */ |
Daniel Borkmann | f8f6d67 | 2014-05-29 10:22:51 +0200 | [diff] [blame] | 984 | *insn++ = BPF_MOV64_REG(BPF_REG_TMP, BPF_REG_A); |
David S. Miller | 1268e25 | 2014-05-13 13:13:33 -0400 | [diff] [blame] | 985 | /* A = BPF_R0 = *(u8 *) (skb->data + K) */ |
Daniel Borkmann | f8f6d67 | 2014-05-29 10:22:51 +0200 | [diff] [blame] | 986 | *insn++ = BPF_LD_ABS(BPF_B, fp->k); |
Alexei Starovoitov | 9739eef | 2014-05-08 14:10:51 -0700 | [diff] [blame] | 987 | /* A &= 0xf */ |
Daniel Borkmann | f8f6d67 | 2014-05-29 10:22:51 +0200 | [diff] [blame] | 988 | *insn++ = BPF_ALU32_IMM(BPF_AND, BPF_REG_A, 0xf); |
Alexei Starovoitov | 9739eef | 2014-05-08 14:10:51 -0700 | [diff] [blame] | 989 | /* A <<= 2 */ |
Daniel Borkmann | f8f6d67 | 2014-05-29 10:22:51 +0200 | [diff] [blame] | 990 | *insn++ = BPF_ALU32_IMM(BPF_LSH, BPF_REG_A, 2); |
Alexei Starovoitov | 9739eef | 2014-05-08 14:10:51 -0700 | [diff] [blame] | 991 | /* X = A */ |
Daniel Borkmann | f8f6d67 | 2014-05-29 10:22:51 +0200 | [diff] [blame] | 992 | *insn++ = BPF_MOV64_REG(BPF_REG_X, BPF_REG_A); |
Alexei Starovoitov | 9739eef | 2014-05-08 14:10:51 -0700 | [diff] [blame] | 993 | /* A = tmp */ |
Daniel Borkmann | f8f6d67 | 2014-05-29 10:22:51 +0200 | [diff] [blame] | 994 | *insn = BPF_MOV64_REG(BPF_REG_A, BPF_REG_TMP); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 995 | break; |
| 996 | |
| 997 | /* RET_K, RET_A are remaped into 2 insns. */ |
| 998 | case BPF_RET | BPF_A: |
| 999 | case BPF_RET | BPF_K: |
Daniel Borkmann | f8f6d67 | 2014-05-29 10:22:51 +0200 | [diff] [blame] | 1000 | *insn++ = BPF_MOV32_RAW(BPF_RVAL(fp->code) == BPF_K ? |
| 1001 | BPF_K : BPF_X, BPF_REG_0, |
| 1002 | BPF_REG_A, fp->k); |
Alexei Starovoitov | 9739eef | 2014-05-08 14:10:51 -0700 | [diff] [blame] | 1003 | *insn = BPF_EXIT_INSN(); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 1004 | break; |
| 1005 | |
| 1006 | /* Store to stack. */ |
| 1007 | case BPF_ST: |
| 1008 | case BPF_STX: |
Daniel Borkmann | f8f6d67 | 2014-05-29 10:22:51 +0200 | [diff] [blame] | 1009 | *insn = BPF_STX_MEM(BPF_W, BPF_REG_FP, BPF_CLASS(fp->code) == |
| 1010 | BPF_ST ? BPF_REG_A : BPF_REG_X, |
| 1011 | -(BPF_MEMWORDS - fp->k) * 4); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 1012 | break; |
| 1013 | |
| 1014 | /* Load from stack. */ |
| 1015 | case BPF_LD | BPF_MEM: |
| 1016 | case BPF_LDX | BPF_MEM: |
Daniel Borkmann | f8f6d67 | 2014-05-29 10:22:51 +0200 | [diff] [blame] | 1017 | *insn = BPF_LDX_MEM(BPF_W, BPF_CLASS(fp->code) == BPF_LD ? |
| 1018 | BPF_REG_A : BPF_REG_X, BPF_REG_FP, |
| 1019 | -(BPF_MEMWORDS - fp->k) * 4); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 1020 | break; |
| 1021 | |
| 1022 | /* A = K or X = K */ |
| 1023 | case BPF_LD | BPF_IMM: |
| 1024 | case BPF_LDX | BPF_IMM: |
Daniel Borkmann | f8f6d67 | 2014-05-29 10:22:51 +0200 | [diff] [blame] | 1025 | *insn = BPF_MOV32_IMM(BPF_CLASS(fp->code) == BPF_LD ? |
| 1026 | BPF_REG_A : BPF_REG_X, fp->k); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 1027 | break; |
| 1028 | |
| 1029 | /* X = A */ |
| 1030 | case BPF_MISC | BPF_TAX: |
Daniel Borkmann | f8f6d67 | 2014-05-29 10:22:51 +0200 | [diff] [blame] | 1031 | *insn = BPF_MOV64_REG(BPF_REG_X, BPF_REG_A); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 1032 | break; |
| 1033 | |
| 1034 | /* A = X */ |
| 1035 | case BPF_MISC | BPF_TXA: |
Daniel Borkmann | f8f6d67 | 2014-05-29 10:22:51 +0200 | [diff] [blame] | 1036 | *insn = BPF_MOV64_REG(BPF_REG_A, BPF_REG_X); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 1037 | break; |
| 1038 | |
| 1039 | /* A = skb->len or X = skb->len */ |
| 1040 | case BPF_LD | BPF_W | BPF_LEN: |
| 1041 | case BPF_LDX | BPF_W | BPF_LEN: |
Daniel Borkmann | f8f6d67 | 2014-05-29 10:22:51 +0200 | [diff] [blame] | 1042 | *insn = BPF_LDX_MEM(BPF_W, BPF_CLASS(fp->code) == BPF_LD ? |
| 1043 | BPF_REG_A : BPF_REG_X, BPF_REG_CTX, |
| 1044 | offsetof(struct sk_buff, len)); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 1045 | break; |
| 1046 | |
Daniel Borkmann | f8f6d67 | 2014-05-29 10:22:51 +0200 | [diff] [blame] | 1047 | /* Access seccomp_data fields. */ |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 1048 | case BPF_LDX | BPF_ABS | BPF_W: |
Alexei Starovoitov | 9739eef | 2014-05-08 14:10:51 -0700 | [diff] [blame] | 1049 | /* A = *(u32 *) (ctx + K) */ |
| 1050 | *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] | 1051 | break; |
| 1052 | |
Daniel Borkmann | f8f6d67 | 2014-05-29 10:22:51 +0200 | [diff] [blame] | 1053 | /* Unkown instruction. */ |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 1054 | default: |
| 1055 | goto err; |
| 1056 | } |
| 1057 | |
| 1058 | insn++; |
| 1059 | if (new_prog) |
| 1060 | memcpy(new_insn, tmp_insns, |
| 1061 | sizeof(*insn) * (insn - tmp_insns)); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 1062 | new_insn += insn - tmp_insns; |
| 1063 | } |
| 1064 | |
| 1065 | if (!new_prog) { |
| 1066 | /* Only calculating new length. */ |
| 1067 | *new_len = new_insn - new_prog; |
| 1068 | return 0; |
| 1069 | } |
| 1070 | |
| 1071 | pass++; |
| 1072 | if (new_flen != new_insn - new_prog) { |
| 1073 | new_flen = new_insn - new_prog; |
| 1074 | if (pass > 2) |
| 1075 | goto err; |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 1076 | goto do_pass; |
| 1077 | } |
| 1078 | |
| 1079 | kfree(addrs); |
| 1080 | BUG_ON(*new_len != new_flen); |
| 1081 | return 0; |
| 1082 | err: |
| 1083 | kfree(addrs); |
| 1084 | return -EINVAL; |
| 1085 | } |
| 1086 | |
| 1087 | /* Security: |
| 1088 | * |
Eric Dumazet | 2d5311e | 2010-12-01 20:46:24 +0000 | [diff] [blame] | 1089 | * 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] | 1090 | * values (check u32 mem[BPF_MEMWORDS] in sk_run_filter()). |
| 1091 | * |
Eric Dumazet | 2d5311e | 2010-12-01 20:46:24 +0000 | [diff] [blame] | 1092 | * As we dont want to clear mem[] array for each packet going through |
| 1093 | * sk_run_filter(), we check that filter loaded by user never try to read |
| 1094 | * 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] | 1095 | * a malicious user doesn't try to abuse us. |
Eric Dumazet | 2d5311e | 2010-12-01 20:46:24 +0000 | [diff] [blame] | 1096 | */ |
| 1097 | static int check_load_and_stores(struct sock_filter *filter, int flen) |
| 1098 | { |
Daniel Borkmann | 3480593 | 2014-05-29 10:22:50 +0200 | [diff] [blame] | 1099 | u16 *masks, memvalid = 0; /* One bit per cell, 16 cells */ |
Eric Dumazet | 2d5311e | 2010-12-01 20:46:24 +0000 | [diff] [blame] | 1100 | int pc, ret = 0; |
| 1101 | |
| 1102 | BUILD_BUG_ON(BPF_MEMWORDS > 16); |
Daniel Borkmann | 3480593 | 2014-05-29 10:22:50 +0200 | [diff] [blame] | 1103 | |
Tobias Klauser | 99e72a0 | 2014-06-24 15:33:22 +0200 | [diff] [blame] | 1104 | masks = kmalloc_array(flen, sizeof(*masks), GFP_KERNEL); |
Eric Dumazet | 2d5311e | 2010-12-01 20:46:24 +0000 | [diff] [blame] | 1105 | if (!masks) |
| 1106 | return -ENOMEM; |
Daniel Borkmann | 3480593 | 2014-05-29 10:22:50 +0200 | [diff] [blame] | 1107 | |
Eric Dumazet | 2d5311e | 2010-12-01 20:46:24 +0000 | [diff] [blame] | 1108 | memset(masks, 0xff, flen * sizeof(*masks)); |
| 1109 | |
| 1110 | for (pc = 0; pc < flen; pc++) { |
| 1111 | memvalid &= masks[pc]; |
| 1112 | |
| 1113 | switch (filter[pc].code) { |
Daniel Borkmann | 3480593 | 2014-05-29 10:22:50 +0200 | [diff] [blame] | 1114 | case BPF_ST: |
| 1115 | case BPF_STX: |
Eric Dumazet | 2d5311e | 2010-12-01 20:46:24 +0000 | [diff] [blame] | 1116 | memvalid |= (1 << filter[pc].k); |
| 1117 | break; |
Daniel Borkmann | 3480593 | 2014-05-29 10:22:50 +0200 | [diff] [blame] | 1118 | case BPF_LD | BPF_MEM: |
| 1119 | case BPF_LDX | BPF_MEM: |
Eric Dumazet | 2d5311e | 2010-12-01 20:46:24 +0000 | [diff] [blame] | 1120 | if (!(memvalid & (1 << filter[pc].k))) { |
| 1121 | ret = -EINVAL; |
| 1122 | goto error; |
| 1123 | } |
| 1124 | break; |
Daniel Borkmann | 3480593 | 2014-05-29 10:22:50 +0200 | [diff] [blame] | 1125 | case BPF_JMP | BPF_JA: |
| 1126 | /* A jump must set masks on target */ |
Eric Dumazet | 2d5311e | 2010-12-01 20:46:24 +0000 | [diff] [blame] | 1127 | masks[pc + 1 + filter[pc].k] &= memvalid; |
| 1128 | memvalid = ~0; |
| 1129 | break; |
Daniel Borkmann | 3480593 | 2014-05-29 10:22:50 +0200 | [diff] [blame] | 1130 | case BPF_JMP | BPF_JEQ | BPF_K: |
| 1131 | case BPF_JMP | BPF_JEQ | BPF_X: |
| 1132 | case BPF_JMP | BPF_JGE | BPF_K: |
| 1133 | case BPF_JMP | BPF_JGE | BPF_X: |
| 1134 | case BPF_JMP | BPF_JGT | BPF_K: |
| 1135 | case BPF_JMP | BPF_JGT | BPF_X: |
| 1136 | case BPF_JMP | BPF_JSET | BPF_K: |
| 1137 | case BPF_JMP | BPF_JSET | BPF_X: |
| 1138 | /* A jump must set masks on targets */ |
Eric Dumazet | 2d5311e | 2010-12-01 20:46:24 +0000 | [diff] [blame] | 1139 | masks[pc + 1 + filter[pc].jt] &= memvalid; |
| 1140 | masks[pc + 1 + filter[pc].jf] &= memvalid; |
| 1141 | memvalid = ~0; |
| 1142 | break; |
| 1143 | } |
| 1144 | } |
| 1145 | error: |
| 1146 | kfree(masks); |
| 1147 | return ret; |
| 1148 | } |
| 1149 | |
Daniel Borkmann | 3480593 | 2014-05-29 10:22:50 +0200 | [diff] [blame] | 1150 | static bool chk_code_allowed(u16 code_to_probe) |
| 1151 | { |
| 1152 | static const bool codes[] = { |
| 1153 | /* 32 bit ALU operations */ |
| 1154 | [BPF_ALU | BPF_ADD | BPF_K] = true, |
| 1155 | [BPF_ALU | BPF_ADD | BPF_X] = true, |
| 1156 | [BPF_ALU | BPF_SUB | BPF_K] = true, |
| 1157 | [BPF_ALU | BPF_SUB | BPF_X] = true, |
| 1158 | [BPF_ALU | BPF_MUL | BPF_K] = true, |
| 1159 | [BPF_ALU | BPF_MUL | BPF_X] = true, |
| 1160 | [BPF_ALU | BPF_DIV | BPF_K] = true, |
| 1161 | [BPF_ALU | BPF_DIV | BPF_X] = true, |
| 1162 | [BPF_ALU | BPF_MOD | BPF_K] = true, |
| 1163 | [BPF_ALU | BPF_MOD | BPF_X] = true, |
| 1164 | [BPF_ALU | BPF_AND | BPF_K] = true, |
| 1165 | [BPF_ALU | BPF_AND | BPF_X] = true, |
| 1166 | [BPF_ALU | BPF_OR | BPF_K] = true, |
| 1167 | [BPF_ALU | BPF_OR | BPF_X] = true, |
| 1168 | [BPF_ALU | BPF_XOR | BPF_K] = true, |
| 1169 | [BPF_ALU | BPF_XOR | BPF_X] = true, |
| 1170 | [BPF_ALU | BPF_LSH | BPF_K] = true, |
| 1171 | [BPF_ALU | BPF_LSH | BPF_X] = true, |
| 1172 | [BPF_ALU | BPF_RSH | BPF_K] = true, |
| 1173 | [BPF_ALU | BPF_RSH | BPF_X] = true, |
| 1174 | [BPF_ALU | BPF_NEG] = true, |
| 1175 | /* Load instructions */ |
| 1176 | [BPF_LD | BPF_W | BPF_ABS] = true, |
| 1177 | [BPF_LD | BPF_H | BPF_ABS] = true, |
| 1178 | [BPF_LD | BPF_B | BPF_ABS] = true, |
| 1179 | [BPF_LD | BPF_W | BPF_LEN] = true, |
| 1180 | [BPF_LD | BPF_W | BPF_IND] = true, |
| 1181 | [BPF_LD | BPF_H | BPF_IND] = true, |
| 1182 | [BPF_LD | BPF_B | BPF_IND] = true, |
| 1183 | [BPF_LD | BPF_IMM] = true, |
| 1184 | [BPF_LD | BPF_MEM] = true, |
| 1185 | [BPF_LDX | BPF_W | BPF_LEN] = true, |
| 1186 | [BPF_LDX | BPF_B | BPF_MSH] = true, |
| 1187 | [BPF_LDX | BPF_IMM] = true, |
| 1188 | [BPF_LDX | BPF_MEM] = true, |
| 1189 | /* Store instructions */ |
| 1190 | [BPF_ST] = true, |
| 1191 | [BPF_STX] = true, |
| 1192 | /* Misc instructions */ |
| 1193 | [BPF_MISC | BPF_TAX] = true, |
| 1194 | [BPF_MISC | BPF_TXA] = true, |
| 1195 | /* Return instructions */ |
| 1196 | [BPF_RET | BPF_K] = true, |
| 1197 | [BPF_RET | BPF_A] = true, |
| 1198 | /* Jump instructions */ |
| 1199 | [BPF_JMP | BPF_JA] = true, |
| 1200 | [BPF_JMP | BPF_JEQ | BPF_K] = true, |
| 1201 | [BPF_JMP | BPF_JEQ | BPF_X] = true, |
| 1202 | [BPF_JMP | BPF_JGE | BPF_K] = true, |
| 1203 | [BPF_JMP | BPF_JGE | BPF_X] = true, |
| 1204 | [BPF_JMP | BPF_JGT | BPF_K] = true, |
| 1205 | [BPF_JMP | BPF_JGT | BPF_X] = true, |
| 1206 | [BPF_JMP | BPF_JSET | BPF_K] = true, |
| 1207 | [BPF_JMP | BPF_JSET | BPF_X] = true, |
| 1208 | }; |
| 1209 | |
| 1210 | if (code_to_probe >= ARRAY_SIZE(codes)) |
| 1211 | return false; |
| 1212 | |
| 1213 | return codes[code_to_probe]; |
| 1214 | } |
| 1215 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1216 | /** |
| 1217 | * sk_chk_filter - verify socket filter code |
| 1218 | * @filter: filter to verify |
| 1219 | * @flen: length of filter |
| 1220 | * |
| 1221 | * Check the user's filter code. If we let some ugly |
| 1222 | * filter code slip through kaboom! The filter must contain |
Kris Katterjohn | 9369986 | 2006-01-04 13:58:36 -0800 | [diff] [blame] | 1223 | * no references or jumps that are out of range, no illegal |
| 1224 | * instructions, and must end with a RET instruction. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1225 | * |
Kris Katterjohn | 7b11f69 | 2006-01-13 14:33:06 -0800 | [diff] [blame] | 1226 | * All jumps are forward as they are not signed. |
| 1227 | * |
| 1228 | * Returns 0 if the rule set is legal or -EINVAL if not. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1229 | */ |
Dan Carpenter | 4f25af2 | 2011-10-17 21:04:20 +0000 | [diff] [blame] | 1230 | int sk_chk_filter(struct sock_filter *filter, unsigned int flen) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1231 | { |
Daniel Borkmann | aa1113d | 2012-12-28 10:50:17 +0000 | [diff] [blame] | 1232 | bool anc_found; |
Daniel Borkmann | 3480593 | 2014-05-29 10:22:50 +0200 | [diff] [blame] | 1233 | int pc; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1234 | |
David S. Miller | 1b93ae64 | 2005-12-27 13:57:59 -0800 | [diff] [blame] | 1235 | if (flen == 0 || flen > BPF_MAXINSNS) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1236 | return -EINVAL; |
| 1237 | |
Daniel Borkmann | 3480593 | 2014-05-29 10:22:50 +0200 | [diff] [blame] | 1238 | /* Check the filter code now */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1239 | for (pc = 0; pc < flen; pc++) { |
Tetsuo Handa | cba328f | 2010-11-16 15:19:51 +0000 | [diff] [blame] | 1240 | struct sock_filter *ftest = &filter[pc]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1241 | |
Daniel Borkmann | 3480593 | 2014-05-29 10:22:50 +0200 | [diff] [blame] | 1242 | /* May we actually operate on this code? */ |
| 1243 | if (!chk_code_allowed(ftest->code)) |
Tetsuo Handa | cba328f | 2010-11-16 15:19:51 +0000 | [diff] [blame] | 1244 | return -EINVAL; |
Daniel Borkmann | 3480593 | 2014-05-29 10:22:50 +0200 | [diff] [blame] | 1245 | |
Kris Katterjohn | 9369986 | 2006-01-04 13:58:36 -0800 | [diff] [blame] | 1246 | /* Some instructions need special checks */ |
Daniel Borkmann | 3480593 | 2014-05-29 10:22:50 +0200 | [diff] [blame] | 1247 | switch (ftest->code) { |
| 1248 | case BPF_ALU | BPF_DIV | BPF_K: |
| 1249 | case BPF_ALU | BPF_MOD | BPF_K: |
| 1250 | /* Check for division by zero */ |
Eric Dumazet | b6069a9 | 2012-09-07 22:03:35 +0000 | [diff] [blame] | 1251 | if (ftest->k == 0) |
| 1252 | return -EINVAL; |
| 1253 | break; |
Daniel Borkmann | 3480593 | 2014-05-29 10:22:50 +0200 | [diff] [blame] | 1254 | case BPF_LD | BPF_MEM: |
| 1255 | case BPF_LDX | BPF_MEM: |
| 1256 | case BPF_ST: |
| 1257 | case BPF_STX: |
| 1258 | /* Check for invalid memory addresses */ |
Kris Katterjohn | 9369986 | 2006-01-04 13:58:36 -0800 | [diff] [blame] | 1259 | if (ftest->k >= BPF_MEMWORDS) |
| 1260 | return -EINVAL; |
Hagen Paul Pfeifer | 01f2f3f | 2010-06-19 17:05:36 +0000 | [diff] [blame] | 1261 | break; |
Daniel Borkmann | 3480593 | 2014-05-29 10:22:50 +0200 | [diff] [blame] | 1262 | case BPF_JMP | BPF_JA: |
| 1263 | /* Note, the large ftest->k might cause loops. |
Kris Katterjohn | 9369986 | 2006-01-04 13:58:36 -0800 | [diff] [blame] | 1264 | * Compare this with conditional jumps below, |
| 1265 | * where offsets are limited. --ANK (981016) |
| 1266 | */ |
Daniel Borkmann | 3480593 | 2014-05-29 10:22:50 +0200 | [diff] [blame] | 1267 | if (ftest->k >= (unsigned int)(flen - pc - 1)) |
Kris Katterjohn | 9369986 | 2006-01-04 13:58:36 -0800 | [diff] [blame] | 1268 | return -EINVAL; |
| 1269 | break; |
Daniel Borkmann | 3480593 | 2014-05-29 10:22:50 +0200 | [diff] [blame] | 1270 | case BPF_JMP | BPF_JEQ | BPF_K: |
| 1271 | case BPF_JMP | BPF_JEQ | BPF_X: |
| 1272 | case BPF_JMP | BPF_JGE | BPF_K: |
| 1273 | case BPF_JMP | BPF_JGE | BPF_X: |
| 1274 | case BPF_JMP | BPF_JGT | BPF_K: |
| 1275 | case BPF_JMP | BPF_JGT | BPF_X: |
| 1276 | case BPF_JMP | BPF_JSET | BPF_K: |
| 1277 | case BPF_JMP | BPF_JSET | BPF_X: |
| 1278 | /* Both conditionals must be safe */ |
Hagen Paul Pfeifer | 01f2f3f | 2010-06-19 17:05:36 +0000 | [diff] [blame] | 1279 | if (pc + ftest->jt + 1 >= flen || |
| 1280 | pc + ftest->jf + 1 >= flen) |
| 1281 | return -EINVAL; |
Tetsuo Handa | cba328f | 2010-11-16 15:19:51 +0000 | [diff] [blame] | 1282 | break; |
Daniel Borkmann | 3480593 | 2014-05-29 10:22:50 +0200 | [diff] [blame] | 1283 | case BPF_LD | BPF_W | BPF_ABS: |
| 1284 | case BPF_LD | BPF_H | BPF_ABS: |
| 1285 | case BPF_LD | BPF_B | BPF_ABS: |
Daniel Borkmann | aa1113d | 2012-12-28 10:50:17 +0000 | [diff] [blame] | 1286 | anc_found = false; |
Daniel Borkmann | 3480593 | 2014-05-29 10:22:50 +0200 | [diff] [blame] | 1287 | if (bpf_anc_helper(ftest) & BPF_ANC) |
| 1288 | anc_found = true; |
| 1289 | /* Ancillary operation unknown or unsupported */ |
Daniel Borkmann | aa1113d | 2012-12-28 10:50:17 +0000 | [diff] [blame] | 1290 | if (anc_found == false && ftest->k >= SKF_AD_OFF) |
| 1291 | return -EINVAL; |
Hagen Paul Pfeifer | 01f2f3f | 2010-06-19 17:05:36 +0000 | [diff] [blame] | 1292 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1293 | } |
| 1294 | |
Daniel Borkmann | 3480593 | 2014-05-29 10:22:50 +0200 | [diff] [blame] | 1295 | /* Last instruction must be a RET code */ |
Hagen Paul Pfeifer | 01f2f3f | 2010-06-19 17:05:36 +0000 | [diff] [blame] | 1296 | switch (filter[flen - 1].code) { |
Daniel Borkmann | 3480593 | 2014-05-29 10:22:50 +0200 | [diff] [blame] | 1297 | case BPF_RET | BPF_K: |
| 1298 | case BPF_RET | BPF_A: |
Eric Dumazet | 2d5311e | 2010-12-01 20:46:24 +0000 | [diff] [blame] | 1299 | return check_load_and_stores(filter, flen); |
Tetsuo Handa | cba328f | 2010-11-16 15:19:51 +0000 | [diff] [blame] | 1300 | } |
Daniel Borkmann | 3480593 | 2014-05-29 10:22:50 +0200 | [diff] [blame] | 1301 | |
Tetsuo Handa | cba328f | 2010-11-16 15:19:51 +0000 | [diff] [blame] | 1302 | return -EINVAL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1303 | } |
Stephen Hemminger | b715631 | 2008-04-10 01:33:47 -0700 | [diff] [blame] | 1304 | EXPORT_SYMBOL(sk_chk_filter); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1305 | |
Daniel Borkmann | a3ea269 | 2014-03-28 18:58:19 +0100 | [diff] [blame] | 1306 | static int sk_store_orig_filter(struct sk_filter *fp, |
| 1307 | const struct sock_fprog *fprog) |
| 1308 | { |
| 1309 | unsigned int fsize = sk_filter_proglen(fprog); |
| 1310 | struct sock_fprog_kern *fkprog; |
| 1311 | |
| 1312 | fp->orig_prog = kmalloc(sizeof(*fkprog), GFP_KERNEL); |
| 1313 | if (!fp->orig_prog) |
| 1314 | return -ENOMEM; |
| 1315 | |
| 1316 | fkprog = fp->orig_prog; |
| 1317 | fkprog->len = fprog->len; |
| 1318 | fkprog->filter = kmemdup(fp->insns, fsize, GFP_KERNEL); |
| 1319 | if (!fkprog->filter) { |
| 1320 | kfree(fp->orig_prog); |
| 1321 | return -ENOMEM; |
| 1322 | } |
| 1323 | |
| 1324 | return 0; |
| 1325 | } |
| 1326 | |
| 1327 | static void sk_release_orig_filter(struct sk_filter *fp) |
| 1328 | { |
| 1329 | struct sock_fprog_kern *fprog = fp->orig_prog; |
| 1330 | |
| 1331 | if (fprog) { |
| 1332 | kfree(fprog->filter); |
| 1333 | kfree(fprog); |
| 1334 | } |
| 1335 | } |
| 1336 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1337 | /** |
Eric Dumazet | 46bcf14 | 2010-12-06 09:29:43 -0800 | [diff] [blame] | 1338 | * sk_filter_release_rcu - Release a socket filter by rcu_head |
Pavel Emelyanov | 47e958e | 2007-10-17 21:22:42 -0700 | [diff] [blame] | 1339 | * @rcu: rcu_head that contains the sk_filter to free |
| 1340 | */ |
Daniel Borkmann | fbc907f | 2014-03-28 18:58:20 +0100 | [diff] [blame] | 1341 | static void sk_filter_release_rcu(struct rcu_head *rcu) |
Pavel Emelyanov | 47e958e | 2007-10-17 21:22:42 -0700 | [diff] [blame] | 1342 | { |
| 1343 | struct sk_filter *fp = container_of(rcu, struct sk_filter, rcu); |
| 1344 | |
Daniel Borkmann | a3ea269 | 2014-03-28 18:58:19 +0100 | [diff] [blame] | 1345 | sk_release_orig_filter(fp); |
Alexei Starovoitov | 5fe821a | 2014-05-19 14:56:14 -0700 | [diff] [blame] | 1346 | sk_filter_free(fp); |
Pavel Emelyanov | 47e958e | 2007-10-17 21:22:42 -0700 | [diff] [blame] | 1347 | } |
Daniel Borkmann | fbc907f | 2014-03-28 18:58:20 +0100 | [diff] [blame] | 1348 | |
| 1349 | /** |
| 1350 | * sk_filter_release - release a socket filter |
| 1351 | * @fp: filter to remove |
| 1352 | * |
| 1353 | * Remove a filter from a socket and release its resources. |
| 1354 | */ |
| 1355 | static void sk_filter_release(struct sk_filter *fp) |
| 1356 | { |
| 1357 | if (atomic_dec_and_test(&fp->refcnt)) |
| 1358 | call_rcu(&fp->rcu, sk_filter_release_rcu); |
| 1359 | } |
| 1360 | |
| 1361 | void sk_filter_uncharge(struct sock *sk, struct sk_filter *fp) |
| 1362 | { |
| 1363 | atomic_sub(sk_filter_size(fp->len), &sk->sk_omem_alloc); |
| 1364 | sk_filter_release(fp); |
| 1365 | } |
| 1366 | |
| 1367 | void sk_filter_charge(struct sock *sk, struct sk_filter *fp) |
| 1368 | { |
| 1369 | atomic_inc(&fp->refcnt); |
| 1370 | atomic_add(sk_filter_size(fp->len), &sk->sk_omem_alloc); |
| 1371 | } |
Pavel Emelyanov | 47e958e | 2007-10-17 21:22:42 -0700 | [diff] [blame] | 1372 | |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 1373 | static struct sk_filter *__sk_migrate_realloc(struct sk_filter *fp, |
| 1374 | struct sock *sk, |
| 1375 | unsigned int len) |
| 1376 | { |
| 1377 | struct sk_filter *fp_new; |
| 1378 | |
| 1379 | if (sk == NULL) |
| 1380 | return krealloc(fp, len, GFP_KERNEL); |
| 1381 | |
| 1382 | fp_new = sock_kmalloc(sk, len, GFP_KERNEL); |
| 1383 | if (fp_new) { |
Daniel Borkmann | eb9672f | 2014-05-01 18:34:20 +0200 | [diff] [blame] | 1384 | *fp_new = *fp; |
Tobias Klauser | 285276e | 2014-06-24 15:33:20 +0200 | [diff] [blame] | 1385 | /* As we're keeping orig_prog in fp_new along, |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 1386 | * we need to make sure we're not evicting it |
| 1387 | * from the old fp. |
| 1388 | */ |
| 1389 | fp->orig_prog = NULL; |
| 1390 | sk_filter_uncharge(sk, fp); |
| 1391 | } |
| 1392 | |
| 1393 | return fp_new; |
| 1394 | } |
| 1395 | |
| 1396 | static struct sk_filter *__sk_migrate_filter(struct sk_filter *fp, |
| 1397 | struct sock *sk) |
| 1398 | { |
| 1399 | struct sock_filter *old_prog; |
| 1400 | struct sk_filter *old_fp; |
Daniel Borkmann | 3480593 | 2014-05-29 10:22:50 +0200 | [diff] [blame] | 1401 | int err, new_len, old_len = fp->len; |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 1402 | |
| 1403 | /* We are free to overwrite insns et al right here as it |
| 1404 | * won't be used at this point in time anymore internally |
| 1405 | * after the migration to the internal BPF instruction |
| 1406 | * representation. |
| 1407 | */ |
| 1408 | BUILD_BUG_ON(sizeof(struct sock_filter) != |
| 1409 | sizeof(struct sock_filter_int)); |
| 1410 | |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 1411 | /* Conversion cannot happen on overlapping memory areas, |
| 1412 | * so we need to keep the user BPF around until the 2nd |
| 1413 | * pass. At this time, the user BPF is stored in fp->insns. |
| 1414 | */ |
| 1415 | old_prog = kmemdup(fp->insns, old_len * sizeof(struct sock_filter), |
| 1416 | GFP_KERNEL); |
| 1417 | if (!old_prog) { |
| 1418 | err = -ENOMEM; |
| 1419 | goto out_err; |
| 1420 | } |
| 1421 | |
| 1422 | /* 1st pass: calculate the new program length. */ |
| 1423 | err = sk_convert_filter(old_prog, old_len, NULL, &new_len); |
| 1424 | if (err) |
| 1425 | goto out_err_free; |
| 1426 | |
| 1427 | /* Expand fp for appending the new filter representation. */ |
| 1428 | old_fp = fp; |
| 1429 | fp = __sk_migrate_realloc(old_fp, sk, sk_filter_size(new_len)); |
| 1430 | if (!fp) { |
| 1431 | /* The old_fp is still around in case we couldn't |
| 1432 | * allocate new memory, so uncharge on that one. |
| 1433 | */ |
| 1434 | fp = old_fp; |
| 1435 | err = -ENOMEM; |
| 1436 | goto out_err_free; |
| 1437 | } |
| 1438 | |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 1439 | fp->len = new_len; |
| 1440 | |
| 1441 | /* 2nd pass: remap sock_filter insns into sock_filter_int insns. */ |
| 1442 | err = sk_convert_filter(old_prog, old_len, fp->insnsi, &new_len); |
| 1443 | if (err) |
| 1444 | /* 2nd sk_convert_filter() can fail only if it fails |
| 1445 | * to allocate memory, remapping must succeed. Note, |
| 1446 | * that at this time old_fp has already been released |
| 1447 | * by __sk_migrate_realloc(). |
| 1448 | */ |
| 1449 | goto out_err_free; |
| 1450 | |
Alexei Starovoitov | 5fe821a | 2014-05-19 14:56:14 -0700 | [diff] [blame] | 1451 | sk_filter_select_runtime(fp); |
| 1452 | |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 1453 | kfree(old_prog); |
| 1454 | return fp; |
| 1455 | |
| 1456 | out_err_free: |
| 1457 | kfree(old_prog); |
| 1458 | out_err: |
| 1459 | /* Rollback filter setup. */ |
| 1460 | if (sk != NULL) |
| 1461 | sk_filter_uncharge(sk, fp); |
| 1462 | else |
| 1463 | kfree(fp); |
| 1464 | return ERR_PTR(err); |
| 1465 | } |
| 1466 | |
Alexei Starovoitov | 6225827 | 2014-05-13 19:50:46 -0700 | [diff] [blame] | 1467 | void __weak bpf_int_jit_compile(struct sk_filter *prog) |
| 1468 | { |
| 1469 | } |
| 1470 | |
Alexei Starovoitov | 5fe821a | 2014-05-19 14:56:14 -0700 | [diff] [blame] | 1471 | /** |
| 1472 | * sk_filter_select_runtime - select execution runtime for BPF program |
| 1473 | * @fp: sk_filter populated with internal BPF program |
| 1474 | * |
| 1475 | * try to JIT internal BPF program, if JIT is not available select interpreter |
| 1476 | * BPF program will be executed via SK_RUN_FILTER() macro |
| 1477 | */ |
| 1478 | void sk_filter_select_runtime(struct sk_filter *fp) |
| 1479 | { |
| 1480 | fp->bpf_func = (void *) __sk_run_filter; |
| 1481 | |
| 1482 | /* Probe if internal BPF can be JITed */ |
| 1483 | bpf_int_jit_compile(fp); |
| 1484 | } |
| 1485 | EXPORT_SYMBOL_GPL(sk_filter_select_runtime); |
| 1486 | |
| 1487 | /* free internal BPF program */ |
| 1488 | void sk_filter_free(struct sk_filter *fp) |
| 1489 | { |
| 1490 | bpf_jit_free(fp); |
| 1491 | } |
| 1492 | EXPORT_SYMBOL_GPL(sk_filter_free); |
| 1493 | |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 1494 | static struct sk_filter *__sk_prepare_filter(struct sk_filter *fp, |
| 1495 | struct sock *sk) |
Jiri Pirko | 302d663 | 2012-03-31 11:01:19 +0000 | [diff] [blame] | 1496 | { |
| 1497 | int err; |
| 1498 | |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 1499 | fp->bpf_func = NULL; |
Daniel Borkmann | f8bbbfc | 2014-03-28 18:58:18 +0100 | [diff] [blame] | 1500 | fp->jited = 0; |
Jiri Pirko | 302d663 | 2012-03-31 11:01:19 +0000 | [diff] [blame] | 1501 | |
| 1502 | err = sk_chk_filter(fp->insns, fp->len); |
Leon Yu | 418c96a | 2014-06-01 05:37:25 +0000 | [diff] [blame] | 1503 | if (err) { |
| 1504 | if (sk != NULL) |
| 1505 | sk_filter_uncharge(sk, fp); |
| 1506 | else |
| 1507 | kfree(fp); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 1508 | return ERR_PTR(err); |
Leon Yu | 418c96a | 2014-06-01 05:37:25 +0000 | [diff] [blame] | 1509 | } |
Jiri Pirko | 302d663 | 2012-03-31 11:01:19 +0000 | [diff] [blame] | 1510 | |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 1511 | /* Probe if we can JIT compile the filter and if so, do |
| 1512 | * the compilation of the filter. |
| 1513 | */ |
Jiri Pirko | 302d663 | 2012-03-31 11:01:19 +0000 | [diff] [blame] | 1514 | bpf_jit_compile(fp); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 1515 | |
| 1516 | /* JIT compiler couldn't process this filter, so do the |
| 1517 | * internal BPF translation for the optimized interpreter. |
| 1518 | */ |
Alexei Starovoitov | 5fe821a | 2014-05-19 14:56:14 -0700 | [diff] [blame] | 1519 | if (!fp->jited) |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 1520 | fp = __sk_migrate_filter(fp, sk); |
| 1521 | |
| 1522 | return fp; |
Jiri Pirko | 302d663 | 2012-03-31 11:01:19 +0000 | [diff] [blame] | 1523 | } |
| 1524 | |
| 1525 | /** |
| 1526 | * sk_unattached_filter_create - create an unattached filter |
Randy Dunlap | c6c4b97 | 2012-06-08 14:01:44 +0000 | [diff] [blame] | 1527 | * @pfp: the unattached filter that is created |
Tobias Klauser | 677a9fd | 2014-06-24 15:33:21 +0200 | [diff] [blame] | 1528 | * @fprog: the filter program |
Jiri Pirko | 302d663 | 2012-03-31 11:01:19 +0000 | [diff] [blame] | 1529 | * |
Randy Dunlap | c6c4b97 | 2012-06-08 14:01:44 +0000 | [diff] [blame] | 1530 | * Create a filter independent of any socket. We first run some |
Jiri Pirko | 302d663 | 2012-03-31 11:01:19 +0000 | [diff] [blame] | 1531 | * sanity checks on it to make sure it does not explode on us later. |
| 1532 | * If an error occurs or there is insufficient memory for the filter |
| 1533 | * a negative errno code is returned. On success the return is zero. |
| 1534 | */ |
| 1535 | int sk_unattached_filter_create(struct sk_filter **pfp, |
Daniel Borkmann | b1fcd35 | 2014-05-23 18:43:58 +0200 | [diff] [blame] | 1536 | struct sock_fprog_kern *fprog) |
Jiri Pirko | 302d663 | 2012-03-31 11:01:19 +0000 | [diff] [blame] | 1537 | { |
Daniel Borkmann | a3ea269 | 2014-03-28 18:58:19 +0100 | [diff] [blame] | 1538 | unsigned int fsize = sk_filter_proglen(fprog); |
Jiri Pirko | 302d663 | 2012-03-31 11:01:19 +0000 | [diff] [blame] | 1539 | struct sk_filter *fp; |
Jiri Pirko | 302d663 | 2012-03-31 11:01:19 +0000 | [diff] [blame] | 1540 | |
| 1541 | /* Make sure new filter is there and in the right amounts. */ |
| 1542 | if (fprog->filter == NULL) |
| 1543 | return -EINVAL; |
| 1544 | |
Alexei Starovoitov | d45ed4a | 2013-10-04 00:14:06 -0700 | [diff] [blame] | 1545 | fp = kmalloc(sk_filter_size(fprog->len), GFP_KERNEL); |
Jiri Pirko | 302d663 | 2012-03-31 11:01:19 +0000 | [diff] [blame] | 1546 | if (!fp) |
| 1547 | return -ENOMEM; |
Daniel Borkmann | a3ea269 | 2014-03-28 18:58:19 +0100 | [diff] [blame] | 1548 | |
Jiri Pirko | 302d663 | 2012-03-31 11:01:19 +0000 | [diff] [blame] | 1549 | memcpy(fp->insns, fprog->filter, fsize); |
| 1550 | |
| 1551 | atomic_set(&fp->refcnt, 1); |
| 1552 | fp->len = fprog->len; |
Daniel Borkmann | a3ea269 | 2014-03-28 18:58:19 +0100 | [diff] [blame] | 1553 | /* Since unattached filters are not copied back to user |
| 1554 | * space through sk_get_filter(), we do not need to hold |
| 1555 | * a copy here, and can spare us the work. |
| 1556 | */ |
| 1557 | fp->orig_prog = NULL; |
Jiri Pirko | 302d663 | 2012-03-31 11:01:19 +0000 | [diff] [blame] | 1558 | |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 1559 | /* __sk_prepare_filter() already takes care of uncharging |
| 1560 | * memory in case something goes wrong. |
| 1561 | */ |
| 1562 | fp = __sk_prepare_filter(fp, NULL); |
| 1563 | if (IS_ERR(fp)) |
| 1564 | return PTR_ERR(fp); |
Jiri Pirko | 302d663 | 2012-03-31 11:01:19 +0000 | [diff] [blame] | 1565 | |
| 1566 | *pfp = fp; |
| 1567 | return 0; |
Jiri Pirko | 302d663 | 2012-03-31 11:01:19 +0000 | [diff] [blame] | 1568 | } |
| 1569 | EXPORT_SYMBOL_GPL(sk_unattached_filter_create); |
| 1570 | |
| 1571 | void sk_unattached_filter_destroy(struct sk_filter *fp) |
| 1572 | { |
| 1573 | sk_filter_release(fp); |
| 1574 | } |
| 1575 | EXPORT_SYMBOL_GPL(sk_unattached_filter_destroy); |
| 1576 | |
Pavel Emelyanov | 47e958e | 2007-10-17 21:22:42 -0700 | [diff] [blame] | 1577 | /** |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1578 | * sk_attach_filter - attach a socket filter |
| 1579 | * @fprog: the filter program |
| 1580 | * @sk: the socket to use |
| 1581 | * |
| 1582 | * Attach the user's filter code. We first run some sanity checks on |
| 1583 | * it to make sure it does not explode on us later. If an error |
| 1584 | * occurs or there is insufficient memory for the filter a negative |
| 1585 | * errno code is returned. On success the return is zero. |
| 1586 | */ |
| 1587 | int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk) |
| 1588 | { |
Pavel Emelyanov | d3904b7 | 2007-10-17 21:22:17 -0700 | [diff] [blame] | 1589 | struct sk_filter *fp, *old_fp; |
Daniel Borkmann | a3ea269 | 2014-03-28 18:58:19 +0100 | [diff] [blame] | 1590 | unsigned int fsize = sk_filter_proglen(fprog); |
Alexei Starovoitov | d45ed4a | 2013-10-04 00:14:06 -0700 | [diff] [blame] | 1591 | unsigned int sk_fsize = sk_filter_size(fprog->len); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1592 | int err; |
| 1593 | |
Vincent Bernat | d59577b | 2013-01-16 22:55:49 +0100 | [diff] [blame] | 1594 | if (sock_flag(sk, SOCK_FILTER_LOCKED)) |
| 1595 | return -EPERM; |
| 1596 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1597 | /* Make sure new filter is there and in the right amounts. */ |
Kris Katterjohn | e35bedf | 2006-01-17 02:25:52 -0800 | [diff] [blame] | 1598 | if (fprog->filter == NULL) |
| 1599 | return -EINVAL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1600 | |
Alexei Starovoitov | d45ed4a | 2013-10-04 00:14:06 -0700 | [diff] [blame] | 1601 | fp = sock_kmalloc(sk, sk_fsize, GFP_KERNEL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1602 | if (!fp) |
| 1603 | return -ENOMEM; |
Daniel Borkmann | a3ea269 | 2014-03-28 18:58:19 +0100 | [diff] [blame] | 1604 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1605 | if (copy_from_user(fp->insns, fprog->filter, fsize)) { |
Alexei Starovoitov | d45ed4a | 2013-10-04 00:14:06 -0700 | [diff] [blame] | 1606 | sock_kfree_s(sk, fp, sk_fsize); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1607 | return -EFAULT; |
| 1608 | } |
| 1609 | |
| 1610 | atomic_set(&fp->refcnt, 1); |
| 1611 | fp->len = fprog->len; |
| 1612 | |
Daniel Borkmann | a3ea269 | 2014-03-28 18:58:19 +0100 | [diff] [blame] | 1613 | err = sk_store_orig_filter(fp, fprog); |
| 1614 | if (err) { |
| 1615 | sk_filter_uncharge(sk, fp); |
| 1616 | return -ENOMEM; |
| 1617 | } |
| 1618 | |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame] | 1619 | /* __sk_prepare_filter() already takes care of uncharging |
| 1620 | * memory in case something goes wrong. |
| 1621 | */ |
| 1622 | fp = __sk_prepare_filter(fp, sk); |
| 1623 | if (IS_ERR(fp)) |
| 1624 | return PTR_ERR(fp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1625 | |
Eric Dumazet | f91ff5b | 2010-09-27 06:07:30 +0000 | [diff] [blame] | 1626 | old_fp = rcu_dereference_protected(sk->sk_filter, |
| 1627 | sock_owned_by_user(sk)); |
Pavel Emelyanov | d3904b7 | 2007-10-17 21:22:17 -0700 | [diff] [blame] | 1628 | rcu_assign_pointer(sk->sk_filter, fp); |
Pavel Emelyanov | d3904b7 | 2007-10-17 21:22:17 -0700 | [diff] [blame] | 1629 | |
Olof Johansson | 9b013e0 | 2007-10-18 21:48:39 -0700 | [diff] [blame] | 1630 | if (old_fp) |
Eric Dumazet | 46bcf14 | 2010-12-06 09:29:43 -0800 | [diff] [blame] | 1631 | sk_filter_uncharge(sk, old_fp); |
Daniel Borkmann | a3ea269 | 2014-03-28 18:58:19 +0100 | [diff] [blame] | 1632 | |
Pavel Emelyanov | d3904b7 | 2007-10-17 21:22:17 -0700 | [diff] [blame] | 1633 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1634 | } |
Michael S. Tsirkin | 5ff3f07 | 2010-02-14 01:01:00 +0000 | [diff] [blame] | 1635 | EXPORT_SYMBOL_GPL(sk_attach_filter); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1636 | |
Pavel Emelyanov | 55b3332 | 2007-10-17 21:21:26 -0700 | [diff] [blame] | 1637 | int sk_detach_filter(struct sock *sk) |
| 1638 | { |
| 1639 | int ret = -ENOENT; |
| 1640 | struct sk_filter *filter; |
| 1641 | |
Vincent Bernat | d59577b | 2013-01-16 22:55:49 +0100 | [diff] [blame] | 1642 | if (sock_flag(sk, SOCK_FILTER_LOCKED)) |
| 1643 | return -EPERM; |
| 1644 | |
Eric Dumazet | f91ff5b | 2010-09-27 06:07:30 +0000 | [diff] [blame] | 1645 | filter = rcu_dereference_protected(sk->sk_filter, |
| 1646 | sock_owned_by_user(sk)); |
Pavel Emelyanov | 55b3332 | 2007-10-17 21:21:26 -0700 | [diff] [blame] | 1647 | if (filter) { |
Stephen Hemminger | a9b3cd7 | 2011-08-01 16:19:00 +0000 | [diff] [blame] | 1648 | RCU_INIT_POINTER(sk->sk_filter, NULL); |
Eric Dumazet | 46bcf14 | 2010-12-06 09:29:43 -0800 | [diff] [blame] | 1649 | sk_filter_uncharge(sk, filter); |
Pavel Emelyanov | 55b3332 | 2007-10-17 21:21:26 -0700 | [diff] [blame] | 1650 | ret = 0; |
| 1651 | } |
Daniel Borkmann | a3ea269 | 2014-03-28 18:58:19 +0100 | [diff] [blame] | 1652 | |
Pavel Emelyanov | 55b3332 | 2007-10-17 21:21:26 -0700 | [diff] [blame] | 1653 | return ret; |
| 1654 | } |
Michael S. Tsirkin | 5ff3f07 | 2010-02-14 01:01:00 +0000 | [diff] [blame] | 1655 | EXPORT_SYMBOL_GPL(sk_detach_filter); |
Pavel Emelyanov | a8fc927 | 2012-11-01 02:01:48 +0000 | [diff] [blame] | 1656 | |
Daniel Borkmann | a3ea269 | 2014-03-28 18:58:19 +0100 | [diff] [blame] | 1657 | int sk_get_filter(struct sock *sk, struct sock_filter __user *ubuf, |
| 1658 | unsigned int len) |
Pavel Emelyanov | a8fc927 | 2012-11-01 02:01:48 +0000 | [diff] [blame] | 1659 | { |
Daniel Borkmann | a3ea269 | 2014-03-28 18:58:19 +0100 | [diff] [blame] | 1660 | struct sock_fprog_kern *fprog; |
Pavel Emelyanov | a8fc927 | 2012-11-01 02:01:48 +0000 | [diff] [blame] | 1661 | struct sk_filter *filter; |
Daniel Borkmann | a3ea269 | 2014-03-28 18:58:19 +0100 | [diff] [blame] | 1662 | int ret = 0; |
Pavel Emelyanov | a8fc927 | 2012-11-01 02:01:48 +0000 | [diff] [blame] | 1663 | |
| 1664 | lock_sock(sk); |
| 1665 | filter = rcu_dereference_protected(sk->sk_filter, |
Daniel Borkmann | a3ea269 | 2014-03-28 18:58:19 +0100 | [diff] [blame] | 1666 | sock_owned_by_user(sk)); |
Pavel Emelyanov | a8fc927 | 2012-11-01 02:01:48 +0000 | [diff] [blame] | 1667 | if (!filter) |
| 1668 | goto out; |
Daniel Borkmann | a3ea269 | 2014-03-28 18:58:19 +0100 | [diff] [blame] | 1669 | |
| 1670 | /* We're copying the filter that has been originally attached, |
| 1671 | * so no conversion/decode needed anymore. |
| 1672 | */ |
| 1673 | fprog = filter->orig_prog; |
| 1674 | |
| 1675 | ret = fprog->len; |
Pavel Emelyanov | a8fc927 | 2012-11-01 02:01:48 +0000 | [diff] [blame] | 1676 | if (!len) |
Daniel Borkmann | a3ea269 | 2014-03-28 18:58:19 +0100 | [diff] [blame] | 1677 | /* User space only enquires number of filter blocks. */ |
Pavel Emelyanov | a8fc927 | 2012-11-01 02:01:48 +0000 | [diff] [blame] | 1678 | goto out; |
Daniel Borkmann | a3ea269 | 2014-03-28 18:58:19 +0100 | [diff] [blame] | 1679 | |
Pavel Emelyanov | a8fc927 | 2012-11-01 02:01:48 +0000 | [diff] [blame] | 1680 | ret = -EINVAL; |
Daniel Borkmann | a3ea269 | 2014-03-28 18:58:19 +0100 | [diff] [blame] | 1681 | if (len < fprog->len) |
Pavel Emelyanov | a8fc927 | 2012-11-01 02:01:48 +0000 | [diff] [blame] | 1682 | goto out; |
| 1683 | |
| 1684 | ret = -EFAULT; |
Daniel Borkmann | a3ea269 | 2014-03-28 18:58:19 +0100 | [diff] [blame] | 1685 | if (copy_to_user(ubuf, fprog->filter, sk_filter_proglen(fprog))) |
| 1686 | goto out; |
Pavel Emelyanov | a8fc927 | 2012-11-01 02:01:48 +0000 | [diff] [blame] | 1687 | |
Daniel Borkmann | a3ea269 | 2014-03-28 18:58:19 +0100 | [diff] [blame] | 1688 | /* Instead of bytes, the API requests to return the number |
| 1689 | * of filter blocks. |
| 1690 | */ |
| 1691 | ret = fprog->len; |
Pavel Emelyanov | a8fc927 | 2012-11-01 02:01:48 +0000 | [diff] [blame] | 1692 | out: |
| 1693 | release_sock(sk); |
| 1694 | return ret; |
| 1695 | } |