Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Linux Socket Filter Data Structures |
| 3 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4 | #ifndef __LINUX_FILTER_H__ |
| 5 | #define __LINUX_FILTER_H__ |
| 6 | |
Arun Sharma | 60063497 | 2011-07-26 16:09:06 -0700 | [diff] [blame] | 7 | #include <linux/atomic.h> |
Will Drewry | 0c5fe1b | 2012-04-12 16:47:53 -0500 | [diff] [blame] | 8 | #include <linux/compat.h> |
Alexei Starovoitov | d45ed4a | 2013-10-04 00:14:06 -0700 | [diff] [blame] | 9 | #include <linux/workqueue.h> |
David Howells | 607ca46 | 2012-10-13 10:46:48 +0100 | [diff] [blame] | 10 | #include <uapi/linux/filter.h> |
Heiko Carstens | 792d4b5 | 2011-05-22 07:08:11 +0000 | [diff] [blame] | 11 | |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame^] | 12 | /* Internally used and optimized filter representation with extended |
| 13 | * instruction set based on top of classic BPF. |
Will Drewry | 0c5fe1b | 2012-04-12 16:47:53 -0500 | [diff] [blame] | 14 | */ |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame^] | 15 | |
| 16 | /* instruction classes */ |
| 17 | #define BPF_ALU64 0x07 /* alu mode in double word width */ |
| 18 | |
| 19 | /* ld/ldx fields */ |
| 20 | #define BPF_DW 0x18 /* double word */ |
| 21 | #define BPF_XADD 0xc0 /* exclusive add */ |
| 22 | |
| 23 | /* alu/jmp fields */ |
| 24 | #define BPF_MOV 0xb0 /* mov reg to reg */ |
| 25 | #define BPF_ARSH 0xc0 /* sign extending arithmetic shift right */ |
| 26 | |
| 27 | /* change endianness of a register */ |
| 28 | #define BPF_END 0xd0 /* flags for endianness conversion: */ |
| 29 | #define BPF_TO_LE 0x00 /* convert to little-endian */ |
| 30 | #define BPF_TO_BE 0x08 /* convert to big-endian */ |
| 31 | #define BPF_FROM_LE BPF_TO_LE |
| 32 | #define BPF_FROM_BE BPF_TO_BE |
| 33 | |
| 34 | #define BPF_JNE 0x50 /* jump != */ |
| 35 | #define BPF_JSGT 0x60 /* SGT is signed '>', GT in x86 */ |
| 36 | #define BPF_JSGE 0x70 /* SGE is signed '>=', GE in x86 */ |
| 37 | #define BPF_CALL 0x80 /* function call */ |
| 38 | #define BPF_EXIT 0x90 /* function return */ |
| 39 | |
| 40 | /* BPF has 10 general purpose 64-bit registers and stack frame. */ |
| 41 | #define MAX_BPF_REG 11 |
| 42 | |
| 43 | /* BPF program can access up to 512 bytes of stack space. */ |
| 44 | #define MAX_BPF_STACK 512 |
| 45 | |
| 46 | /* Arg1, context and stack frame pointer register positions. */ |
| 47 | #define ARG1_REG 1 |
| 48 | #define CTX_REG 6 |
| 49 | #define FP_REG 10 |
| 50 | |
| 51 | struct sock_filter_int { |
| 52 | __u8 code; /* opcode */ |
| 53 | __u8 a_reg:4; /* dest register */ |
| 54 | __u8 x_reg:4; /* source register */ |
| 55 | __s16 off; /* signed offset */ |
| 56 | __s32 imm; /* signed immediate constant */ |
| 57 | }; |
| 58 | |
| 59 | #ifdef CONFIG_COMPAT |
| 60 | /* A struct sock_filter is architecture independent. */ |
Will Drewry | 0c5fe1b | 2012-04-12 16:47:53 -0500 | [diff] [blame] | 61 | struct compat_sock_fprog { |
| 62 | u16 len; |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame^] | 63 | compat_uptr_t filter; /* struct sock_filter * */ |
Will Drewry | 0c5fe1b | 2012-04-12 16:47:53 -0500 | [diff] [blame] | 64 | }; |
| 65 | #endif |
| 66 | |
Daniel Borkmann | a3ea269 | 2014-03-28 18:58:19 +0100 | [diff] [blame] | 67 | struct sock_fprog_kern { |
| 68 | u16 len; |
| 69 | struct sock_filter *filter; |
| 70 | }; |
| 71 | |
Heiko Carstens | 792d4b5 | 2011-05-22 07:08:11 +0000 | [diff] [blame] | 72 | struct sk_buff; |
| 73 | struct sock; |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame^] | 74 | struct seccomp_data; |
Heiko Carstens | 792d4b5 | 2011-05-22 07:08:11 +0000 | [diff] [blame] | 75 | |
Daniel Borkmann | a3ea269 | 2014-03-28 18:58:19 +0100 | [diff] [blame] | 76 | struct sk_filter { |
Stephen Hemminger | b715631 | 2008-04-10 01:33:47 -0700 | [diff] [blame] | 77 | atomic_t refcnt; |
Daniel Borkmann | f8bbbfc | 2014-03-28 18:58:18 +0100 | [diff] [blame] | 78 | u32 jited:1, /* Is our filter JIT'ed? */ |
| 79 | len:31; /* Number of filter blocks */ |
Daniel Borkmann | a3ea269 | 2014-03-28 18:58:19 +0100 | [diff] [blame] | 80 | struct sock_fprog_kern *orig_prog; /* Original BPF program */ |
Alexei Starovoitov | d45ed4a | 2013-10-04 00:14:06 -0700 | [diff] [blame] | 81 | struct rcu_head rcu; |
Eric Dumazet | 0a14842 | 2011-04-20 09:27:32 +0000 | [diff] [blame] | 82 | unsigned int (*bpf_func)(const struct sk_buff *skb, |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame^] | 83 | const struct sock_filter_int *filter); |
Alexei Starovoitov | d45ed4a | 2013-10-04 00:14:06 -0700 | [diff] [blame] | 84 | union { |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame^] | 85 | struct sock_filter insns[0]; |
| 86 | struct sock_filter_int insnsi[0]; |
Alexei Starovoitov | d45ed4a | 2013-10-04 00:14:06 -0700 | [diff] [blame] | 87 | struct work_struct work; |
| 88 | }; |
Stephen Hemminger | b715631 | 2008-04-10 01:33:47 -0700 | [diff] [blame] | 89 | }; |
| 90 | |
Alexei Starovoitov | d45ed4a | 2013-10-04 00:14:06 -0700 | [diff] [blame] | 91 | static inline unsigned int sk_filter_size(unsigned int proglen) |
Stephen Hemminger | b715631 | 2008-04-10 01:33:47 -0700 | [diff] [blame] | 92 | { |
Alexei Starovoitov | d45ed4a | 2013-10-04 00:14:06 -0700 | [diff] [blame] | 93 | return max(sizeof(struct sk_filter), |
| 94 | offsetof(struct sk_filter, insns[proglen])); |
Stephen Hemminger | b715631 | 2008-04-10 01:33:47 -0700 | [diff] [blame] | 95 | } |
| 96 | |
Daniel Borkmann | a3ea269 | 2014-03-28 18:58:19 +0100 | [diff] [blame] | 97 | #define sk_filter_proglen(fprog) \ |
| 98 | (fprog->len * sizeof(fprog->filter[0])) |
| 99 | |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame^] | 100 | #define SK_RUN_FILTER(filter, ctx) \ |
| 101 | (*filter->bpf_func)(ctx, filter->insnsi) |
| 102 | |
Daniel Borkmann | fbc907f | 2014-03-28 18:58:20 +0100 | [diff] [blame] | 103 | int sk_filter(struct sock *sk, struct sk_buff *skb); |
Alexei Starovoitov | bd4cf0e | 2014-03-28 18:58:25 +0100 | [diff] [blame^] | 104 | |
| 105 | u32 sk_run_filter_int_seccomp(const struct seccomp_data *ctx, |
| 106 | const struct sock_filter_int *insni); |
| 107 | u32 sk_run_filter_int_skb(const struct sk_buff *ctx, |
| 108 | const struct sock_filter_int *insni); |
| 109 | |
| 110 | int sk_convert_filter(struct sock_filter *prog, int len, |
| 111 | struct sock_filter_int *new_prog, int *new_len); |
Daniel Borkmann | a3ea269 | 2014-03-28 18:58:19 +0100 | [diff] [blame] | 112 | |
Daniel Borkmann | fbc907f | 2014-03-28 18:58:20 +0100 | [diff] [blame] | 113 | int sk_unattached_filter_create(struct sk_filter **pfp, |
| 114 | struct sock_fprog *fprog); |
| 115 | void sk_unattached_filter_destroy(struct sk_filter *fp); |
Daniel Borkmann | a3ea269 | 2014-03-28 18:58:19 +0100 | [diff] [blame] | 116 | |
Daniel Borkmann | fbc907f | 2014-03-28 18:58:20 +0100 | [diff] [blame] | 117 | int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk); |
| 118 | int sk_detach_filter(struct sock *sk); |
Daniel Borkmann | a3ea269 | 2014-03-28 18:58:19 +0100 | [diff] [blame] | 119 | |
Daniel Borkmann | fbc907f | 2014-03-28 18:58:20 +0100 | [diff] [blame] | 120 | int sk_chk_filter(struct sock_filter *filter, unsigned int flen); |
| 121 | int sk_get_filter(struct sock *sk, struct sock_filter __user *filter, |
| 122 | unsigned int len); |
| 123 | void sk_decode_filter(struct sock_filter *filt, struct sock_filter *to); |
| 124 | |
| 125 | void sk_filter_charge(struct sock *sk, struct sk_filter *fp); |
| 126 | void sk_filter_uncharge(struct sock *sk, struct sk_filter *fp); |
Eric Dumazet | 0a14842 | 2011-04-20 09:27:32 +0000 | [diff] [blame] | 127 | |
| 128 | #ifdef CONFIG_BPF_JIT |
Xi Wang | 20074f3 | 2013-05-01 16:24:08 -0400 | [diff] [blame] | 129 | #include <stdarg.h> |
Chen Gang | a691ce7 | 2013-03-28 15:24:53 +0000 | [diff] [blame] | 130 | #include <linux/linkage.h> |
| 131 | #include <linux/printk.h> |
| 132 | |
Daniel Borkmann | fbc907f | 2014-03-28 18:58:20 +0100 | [diff] [blame] | 133 | void bpf_jit_compile(struct sk_filter *fp); |
| 134 | void bpf_jit_free(struct sk_filter *fp); |
Daniel Borkmann | 7961780 | 2013-03-21 22:22:03 +0100 | [diff] [blame] | 135 | |
| 136 | static inline void bpf_jit_dump(unsigned int flen, unsigned int proglen, |
| 137 | u32 pass, void *image) |
| 138 | { |
Eric Dumazet | 1649544 | 2013-05-17 16:57:37 +0000 | [diff] [blame] | 139 | pr_err("flen=%u proglen=%u pass=%u image=%pK\n", |
Daniel Borkmann | 7961780 | 2013-03-21 22:22:03 +0100 | [diff] [blame] | 140 | flen, proglen, pass, image); |
| 141 | if (image) |
Eric Dumazet | 1649544 | 2013-05-17 16:57:37 +0000 | [diff] [blame] | 142 | print_hex_dump(KERN_ERR, "JIT code: ", DUMP_PREFIX_OFFSET, |
Daniel Borkmann | 7961780 | 2013-03-21 22:22:03 +0100 | [diff] [blame] | 143 | 16, 1, image, proglen, false); |
| 144 | } |
Eric Dumazet | 0a14842 | 2011-04-20 09:27:32 +0000 | [diff] [blame] | 145 | #else |
Alexei Starovoitov | d45ed4a | 2013-10-04 00:14:06 -0700 | [diff] [blame] | 146 | #include <linux/slab.h> |
Eric Dumazet | 0a14842 | 2011-04-20 09:27:32 +0000 | [diff] [blame] | 147 | static inline void bpf_jit_compile(struct sk_filter *fp) |
| 148 | { |
| 149 | } |
| 150 | static inline void bpf_jit_free(struct sk_filter *fp) |
| 151 | { |
Alexei Starovoitov | d45ed4a | 2013-10-04 00:14:06 -0700 | [diff] [blame] | 152 | kfree(fp); |
Eric Dumazet | 0a14842 | 2011-04-20 09:27:32 +0000 | [diff] [blame] | 153 | } |
Eric Dumazet | 0a14842 | 2011-04-20 09:27:32 +0000 | [diff] [blame] | 154 | #endif |
| 155 | |
Michal Sekletar | ea02f94 | 2014-01-17 17:09:45 +0100 | [diff] [blame] | 156 | static inline int bpf_tell_extensions(void) |
| 157 | { |
Daniel Borkmann | 3769229 | 2014-01-21 00:19:37 +0100 | [diff] [blame] | 158 | return SKF_AD_MAX; |
Michal Sekletar | ea02f94 | 2014-01-17 17:09:45 +0100 | [diff] [blame] | 159 | } |
| 160 | |
Eric Dumazet | 0a14842 | 2011-04-20 09:27:32 +0000 | [diff] [blame] | 161 | enum { |
| 162 | BPF_S_RET_K = 1, |
| 163 | BPF_S_RET_A, |
| 164 | BPF_S_ALU_ADD_K, |
| 165 | BPF_S_ALU_ADD_X, |
| 166 | BPF_S_ALU_SUB_K, |
| 167 | BPF_S_ALU_SUB_X, |
| 168 | BPF_S_ALU_MUL_K, |
| 169 | BPF_S_ALU_MUL_X, |
| 170 | BPF_S_ALU_DIV_X, |
Eric Dumazet | b6069a9 | 2012-09-07 22:03:35 +0000 | [diff] [blame] | 171 | BPF_S_ALU_MOD_K, |
| 172 | BPF_S_ALU_MOD_X, |
Eric Dumazet | 0a14842 | 2011-04-20 09:27:32 +0000 | [diff] [blame] | 173 | BPF_S_ALU_AND_K, |
| 174 | BPF_S_ALU_AND_X, |
| 175 | BPF_S_ALU_OR_K, |
| 176 | BPF_S_ALU_OR_X, |
Daniel Borkmann | 9e49e88 | 2012-09-24 02:23:59 +0000 | [diff] [blame] | 177 | BPF_S_ALU_XOR_K, |
| 178 | BPF_S_ALU_XOR_X, |
Eric Dumazet | 0a14842 | 2011-04-20 09:27:32 +0000 | [diff] [blame] | 179 | BPF_S_ALU_LSH_K, |
| 180 | BPF_S_ALU_LSH_X, |
| 181 | BPF_S_ALU_RSH_K, |
| 182 | BPF_S_ALU_RSH_X, |
| 183 | BPF_S_ALU_NEG, |
| 184 | BPF_S_LD_W_ABS, |
| 185 | BPF_S_LD_H_ABS, |
| 186 | BPF_S_LD_B_ABS, |
| 187 | BPF_S_LD_W_LEN, |
| 188 | BPF_S_LD_W_IND, |
| 189 | BPF_S_LD_H_IND, |
| 190 | BPF_S_LD_B_IND, |
| 191 | BPF_S_LD_IMM, |
| 192 | BPF_S_LDX_W_LEN, |
| 193 | BPF_S_LDX_B_MSH, |
| 194 | BPF_S_LDX_IMM, |
| 195 | BPF_S_MISC_TAX, |
| 196 | BPF_S_MISC_TXA, |
| 197 | BPF_S_ALU_DIV_K, |
| 198 | BPF_S_LD_MEM, |
| 199 | BPF_S_LDX_MEM, |
| 200 | BPF_S_ST, |
| 201 | BPF_S_STX, |
| 202 | BPF_S_JMP_JA, |
| 203 | BPF_S_JMP_JEQ_K, |
| 204 | BPF_S_JMP_JEQ_X, |
| 205 | BPF_S_JMP_JGE_K, |
| 206 | BPF_S_JMP_JGE_X, |
| 207 | BPF_S_JMP_JGT_K, |
| 208 | BPF_S_JMP_JGT_X, |
| 209 | BPF_S_JMP_JSET_K, |
| 210 | BPF_S_JMP_JSET_X, |
| 211 | /* Ancillary data */ |
| 212 | BPF_S_ANC_PROTOCOL, |
| 213 | BPF_S_ANC_PKTTYPE, |
| 214 | BPF_S_ANC_IFINDEX, |
| 215 | BPF_S_ANC_NLATTR, |
| 216 | BPF_S_ANC_NLATTR_NEST, |
| 217 | BPF_S_ANC_MARK, |
| 218 | BPF_S_ANC_QUEUE, |
| 219 | BPF_S_ANC_HATYPE, |
| 220 | BPF_S_ANC_RXHASH, |
| 221 | BPF_S_ANC_CPU, |
Jiri Pirko | ffe06c1 | 2012-03-31 11:01:20 +0000 | [diff] [blame] | 222 | BPF_S_ANC_ALU_XOR_X, |
Will Drewry | 46b325c | 2012-04-12 16:47:52 -0500 | [diff] [blame] | 223 | BPF_S_ANC_SECCOMP_LD_W, |
Eric Dumazet | f333503 | 2012-10-27 02:26:17 +0000 | [diff] [blame] | 224 | BPF_S_ANC_VLAN_TAG, |
| 225 | BPF_S_ANC_VLAN_TAG_PRESENT, |
Daniel Borkmann | 3e5289d | 2013-03-19 06:39:31 +0000 | [diff] [blame] | 226 | BPF_S_ANC_PAY_OFFSET, |
Eric Dumazet | 0a14842 | 2011-04-20 09:27:32 +0000 | [diff] [blame] | 227 | }; |
| 228 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 229 | #endif /* __LINUX_FILTER_H__ */ |