/*
* Linux Socket Filter Data Structures
*/
#ifndef __LINUX_FILTER_H__
#define __LINUX_FILTER_H__
#include <linux/atomic.h>
#include <linux/compat.h>
#include <linux/workqueue.h>
#include <uapi/linux/filter.h>
/* Internally used and optimized filter representation with extended
* instruction set based on top of classic BPF.
*/
/* instruction classes */
#define BPF_ALU64 0x07 /* alu mode in double word width */
/* ld/ldx fields */
#define BPF_DW 0x18 /* double word */
#define BPF_XADD 0xc0 /* exclusive add */
/* alu/jmp fields */
#define BPF_MOV 0xb0 /* mov reg to reg */
#define BPF_ARSH 0xc0 /* sign extending arithmetic shift right */
/* change endianness of a register */
#define BPF_END 0xd0 /* flags for endianness conversion: */
#define BPF_TO_LE 0x00 /* convert to little-endian */
#define BPF_TO_BE 0x08 /* convert to big-endian */
#define BPF_FROM_LE BPF_TO_LE
#define BPF_FROM_BE BPF_TO_BE
#define BPF_JNE 0x50 /* jump != */
#define BPF_JSGT 0x60 /* SGT is signed '>', GT in x86 */
#define BPF_JSGE 0x70 /* SGE is signed '>=', GE in x86 */
#define BPF_CALL 0x80 /* function call */
#define BPF_EXIT 0x90 /* function return */
/* Placeholder/dummy for 0 */
#define BPF_0 0
/* Register numbers */
enum {
BPF_REG_0 = 0,
BPF_REG_1,
BPF_REG_2,
BPF_REG_3,
BPF_REG_4,
BPF_REG_5,
BPF_REG_6,
BPF_REG_7,
BPF_REG_8,
BPF_REG_9,
BPF_REG_10,
__MAX_BPF_REG,
};
/* BPF has 10 general purpose 64-bit registers and stack frame. */
#define MAX_BPF_REG __MAX_BPF_REG
/* ArgX, context and stack frame pointer register positions. Note,
* Arg1, Arg2, Arg3, etc are used as argument mappings of function
* calls in BPF_CALL instruction.
*/
#define BPF_REG_ARG1 BPF_REG_1
#define BPF_REG_ARG2 BPF_REG_2
#define BPF_REG_ARG3 BPF_REG_3
#define BPF_REG_ARG4 BPF_REG_4
#define BPF_REG_ARG5 BPF_REG_5
#define BPF_REG_CTX BPF_REG_6
#define BPF_REG_FP BPF_REG_10
/* Additional register mappings for converted user programs. */
#define BPF_REG_A BPF_REG_0
#define BPF_REG_X BPF_REG_7
#define BPF_REG_TMP BPF_REG_8
/* BPF program can access up to 512 bytes of stack space. */
#define MAX_BPF_STACK 512
/* bpf_add|sub|...: a += x, bpf_mov: a = x */
#define BPF_ALU64_REG(op, a, x) \
((struct sock_filter_int) {BPF_ALU64|BPF_OP(op)|BPF_X, a, x, 0, 0})
#define BPF_ALU32_REG(op, a, x) \
((struct sock_filter_int) {BPF_ALU|BPF_OP(op)|BPF_X, a, x, 0, 0})
/* bpf_add|sub|...: a += imm, bpf_mov: a = imm */
#define BPF_ALU64_IMM(op, a, imm) \
((struct sock_filter_int) {BPF_ALU64|BPF_OP(op)|BPF_K, a, 0, 0, imm})
#define BPF_ALU32_IMM(op, a, imm) \
((struct sock_filter_int) {BPF_ALU|BPF_OP(op)|BPF_K, a, 0, 0, imm})
/* R0 = *(uint *) (skb->data + off) */
#define BPF_LD_ABS(size, off) \
((struct sock_filter_int) {BPF_LD|BPF_SIZE(size)|BPF_ABS, 0, 0, 0, off})
/* R0 = *(uint *) (skb->data + x + off) */
#define BPF_LD_IND(size, x, off) \
((struct sock_filter_int) {BPF_LD|BPF_SIZE(size)|BPF_IND, 0, x, 0, off})
/* a = *(uint *) (x + off) */
#define BPF_LDX_MEM(sz, a, x, off) \
((struct sock_filter_int) {BPF_LDX|BPF_SIZE(sz)|BPF_MEM, a, x, off, 0})
/* if (a 'op' x) goto pc+off */
#define BPF_JMP_REG(op, a, x, off) \
((struct sock_filter_int) {BPF_JMP|BPF_OP(op)|BPF_X, a, x, off, 0})
/* if (a 'op' imm) goto pc+off */
#define BPF_JMP_IMM(op, a, imm, off) \
((struct sock_filter_int) {BPF_JMP|BPF_OP(op)|BPF_K, a, 0, off, imm})
#define BPF_EXIT_INSN() \
((struct sock_filter_int) {BPF_JMP|BPF_EXIT, 0, 0, 0, 0})
static inline int size_to_bpf(int size)
{
switch (size) {
case 1:
return BPF_B;
case 2:
return BPF_H;
case 4:
return BPF_W;
case 8:
return BPF_DW;
default:
return -EINVAL;
}
}
/* Macro to invoke filter function. */
#define SK_RUN_FILTER(filter, ctx) (*filter->bpf_func)(ctx, filter->insnsi)
struct sock_filter_int {
__u8 code; /* opcode */
__u8 a_reg:4; /* dest register */
__u8 x_reg:4; /* source register */
__s16 off; /* signed offset */
__s32 imm; /* signed immediate constant */
};
#ifdef CONFIG_COMPAT
/* A struct sock_filter is architecture independent. */
struct compat_sock_fprog {
u16 len;
compat_uptr_t filter; /* struct sock_filter * */
};
#endif
struct sock_fprog_kern {
u16 len;
struct sock_filter *filter;
};
struct sk_buff;
struct sock;
struct seccomp_data;
struct sk_filter {
atomic_t refcnt;
u32 jited:1, /* Is our filter JIT'ed? */
len:31; /* Number of filter blocks */
struct sock_fprog_kern *orig_prog; /* Original BPF program */
struct rcu_head rcu;
unsigned int (*bpf_func)(const struct sk_buff *skb,
const struct sock_filter_int *filter);
union {
struct sock_filter insns[0];
struct sock_filter_int insnsi[0];
struct work_struct work;
};
};
static inline unsigned int sk_filter_size(unsigned int proglen)
{
return max(sizeof(struct sk_filter),
offsetof(struct sk_filter, insns[proglen]));
}
#define sk_filter_proglen(fprog) \
(fprog->len * sizeof(fprog->filter[0]))
int sk_filter(struct sock *sk, struct sk_buff *skb);
u32 sk_run_filter_int_seccomp(const struct seccomp_data *ctx,
const struct sock_filter_int *insni);
u32 sk_run_filter_int_skb(const struct sk_buff *ctx,
const struct sock_filter_int *insni);
int sk_convert_filter(struct sock_filter *prog, int len,
struct sock_filter_int *new_prog, int *new_len);
int sk_unattached_filter_create(struct sk_filter **pfp,
struct sock_fprog *fprog);
void sk_unattached_filter_destroy(struct sk_filter *fp);
int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk);
int sk_detach_filter(struct sock *sk);
int sk_chk_filter(struct sock_filter *filter, unsigned int flen);
int sk_get_filter(struct sock *sk, struct sock_filter __user *filter,
unsigned int len);
void sk_decode_filter(struct sock_filter *filt, struct sock_filter *to);
void sk_filter_charge(struct sock *sk, struct sk_filter *fp);
void sk_filter_uncharge(struct sock *sk, struct sk_filter *fp);
#ifdef CONFIG_BPF_JIT
#include <stdarg.h>
#include <linux/linkage.h>
#include <linux/printk.h>
void bpf_jit_compile(struct sk_filter *fp);
void bpf_jit_free(struct sk_filter *fp);
static inline void bpf_jit_dump(unsigned int flen, unsigned int proglen,
u32 pass, void *image)
{
pr_err("flen=%u proglen=%u pass=%u image=%pK\n",
flen, proglen, pass, image);
if (image)
print_hex_dump(KERN_ERR, "JIT code: ", DUMP_PREFIX_OFFSET,
16, 1, image, proglen, false);
}
#else
#include <linux/slab.h>
static inline void bpf_jit_compile(struct sk_filter *fp)
{
}
static inline void bpf_jit_free(struct sk_filter *fp)
{
kfree(fp);
}
#endif
static inline int bpf_tell_extensions(void)
{
return SKF_AD_MAX;
}
enum {
BPF_S_RET_K = 1,
BPF_S_RET_A,
BPF_S_ALU_ADD_K,
BPF_S_ALU_ADD_X,
BPF_S_ALU_SUB_K,
BPF_S_ALU_SUB_X,
BPF_S_ALU_MUL_K,
BPF_S_ALU_MUL_X,
BPF_S_ALU_DIV_X,
BPF_S_ALU_MOD_K,
BPF_S_ALU_MOD_X,
BPF_S_ALU_AND_K,
BPF_S_ALU_AND_X,
BPF_S_ALU_OR_K,
BPF_S_ALU_OR_X,
BPF_S_ALU_XOR_K,
BPF_S_ALU_XOR_X,
BPF_S_ALU_LSH_K,
BPF_S_ALU_LSH_X,
BPF_S_ALU_RSH_K,
BPF_S_ALU_RSH_X,
BPF_S_ALU_NEG,
BPF_S_LD_W_ABS,
BPF_S_LD_H_ABS,
BPF_S_LD_B_ABS,
BPF_S_LD_W_LEN,
BPF_S_LD_W_IND,
BPF_S_LD_H_IND,
BPF_S_LD_B_IND,
BPF_S_LD_IMM,
BPF_S_LDX_W_LEN,
BPF_S_LDX_B_MSH,
BPF_S_LDX_IMM,
BPF_S_MISC_TAX,
BPF_S_MISC_TXA,
BPF_S_ALU_DIV_K,
BPF_S_LD_MEM,
BPF_S_LDX_MEM,
BPF_S_ST,
BPF_S_STX,
BPF_S_JMP_JA,
BPF_S_JMP_JEQ_K,
BPF_S_JMP_JEQ_X,
BPF_S_JMP_JGE_K,
BPF_S_JMP_JGE_X,
BPF_S_JMP_JGT_K,
BPF_S_JMP_JGT_X,
BPF_S_JMP_JSET_K,
BPF_S_JMP_JSET_X,
/* Ancillary data */
BPF_S_ANC_PROTOCOL,
BPF_S_ANC_PKTTYPE,
BPF_S_ANC_IFINDEX,
BPF_S_ANC_NLATTR,
BPF_S_ANC_NLATTR_NEST,
BPF_S_ANC_MARK,
BPF_S_ANC_QUEUE,
BPF_S_ANC_HATYPE,
BPF_S_ANC_RXHASH,
BPF_S_ANC_CPU,
BPF_S_ANC_ALU_XOR_X,
BPF_S_ANC_VLAN_TAG,
BPF_S_ANC_VLAN_TAG_PRESENT,
BPF_S_ANC_PAY_OFFSET,
BPF_S_ANC_RANDOM,
};
#endif /* __LINUX_FILTER_H__ */
