[mirror_ubuntu-hirsute-kernel.git] / include / linux / filter.h

/*
 * 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 */

/* 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);

void sk_filter_select_runtime(struct sk_filter *fp);
void sk_filter_free(struct sk_filter *fp);

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_kern *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_filter_charge(struct sock *sk, struct sk_filter *fp);
void sk_filter_uncharge(struct sock *sk, struct sk_filter *fp);

u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
void bpf_int_jit_compile(struct sk_filter *fp);

#define BPF_ANC		BIT(15)

static inline u16 bpf_anc_helper(const struct sock_filter *ftest)
{
	BUG_ON(ftest->code & BPF_ANC);

	switch (ftest->code) {
	case BPF_LD | BPF_W | BPF_ABS:
	case BPF_LD | BPF_H | BPF_ABS:
	case BPF_LD | BPF_B | BPF_ABS:
#define BPF_ANCILLARY(CODE)	case SKF_AD_OFF + SKF_AD_##CODE:	\
				return BPF_ANC | SKF_AD_##CODE
		switch (ftest->k) {
		BPF_ANCILLARY(PROTOCOL);
		BPF_ANCILLARY(PKTTYPE);
		BPF_ANCILLARY(IFINDEX);
		BPF_ANCILLARY(NLATTR);
		BPF_ANCILLARY(NLATTR_NEST);
		BPF_ANCILLARY(MARK);
		BPF_ANCILLARY(QUEUE);
		BPF_ANCILLARY(HATYPE);
		BPF_ANCILLARY(RXHASH);
		BPF_ANCILLARY(CPU);
		BPF_ANCILLARY(ALU_XOR_X);
		BPF_ANCILLARY(VLAN_TAG);
		BPF_ANCILLARY(VLAN_TAG_PRESENT);
		BPF_ANCILLARY(PAY_OFFSET);
		BPF_ANCILLARY(RANDOM);
		}
		/* Fallthrough. */
	default:
		return ftest->code;
	}
}

#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 /* CONFIG_BPF_JIT */

static inline int bpf_tell_extensions(void)
{
	return SKF_AD_MAX;
}

#endif /* __LINUX_FILTER_H__ */
Commit	Line	Data
1da177e4 LT	1	/*
	2	* Linux Socket Filter Data Structures
	3	*/
1da177e4 LT	4	#ifndef __LINUX_FILTER_H__
	5	#define __LINUX_FILTER_H__
	6
60063497	7	#include <linux/atomic.h>
0c5fe1b4	8	#include <linux/compat.h>
d45ed4a4	9	#include <linux/workqueue.h>
607ca46e	10	#include <uapi/linux/filter.h>
792d4b5c	11
bd4cf0ed AS	12	/* Internally used and optimized filter representation with extended
bd4cf0ed AS	13	* instruction set based on top of classic BPF.
0c5fe1b4	14	*/
bd4cf0ed AS	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
30743837 DB	40	/* Register numbers */
	41	enum {
	42	BPF_REG_0 = 0,
	43	BPF_REG_1,
	44	BPF_REG_2,
	45	BPF_REG_3,
	46	BPF_REG_4,
	47	BPF_REG_5,
	48	BPF_REG_6,
	49	BPF_REG_7,
	50	BPF_REG_8,
	51	BPF_REG_9,
	52	BPF_REG_10,
	53	__MAX_BPF_REG,
	54	};
	55
bd4cf0ed	56	/* BPF has 10 general purpose 64-bit registers and stack frame. */
30743837 DB	57	#define MAX_BPF_REG __MAX_BPF_REG
	58
	59	/* ArgX, context and stack frame pointer register positions. Note,
	60	* Arg1, Arg2, Arg3, etc are used as argument mappings of function
	61	* calls in BPF_CALL instruction.
	62	*/
	63	#define BPF_REG_ARG1 BPF_REG_1
	64	#define BPF_REG_ARG2 BPF_REG_2
	65	#define BPF_REG_ARG3 BPF_REG_3
	66	#define BPF_REG_ARG4 BPF_REG_4
	67	#define BPF_REG_ARG5 BPF_REG_5
	68	#define BPF_REG_CTX BPF_REG_6
	69	#define BPF_REG_FP BPF_REG_10
	70
	71	/* Additional register mappings for converted user programs. */
	72	#define BPF_REG_A BPF_REG_0
	73	#define BPF_REG_X BPF_REG_7
	74	#define BPF_REG_TMP BPF_REG_8
bd4cf0ed AS	75
	76	/* BPF program can access up to 512 bytes of stack space. */
	77	#define MAX_BPF_STACK 512
	78
9739eef1 AS	79	/* bpf_add\|sub\|...: a += x, bpf_mov: a = x */
	80	#define BPF_ALU64_REG(op, a, x) \
	81	((struct sock_filter_int) {BPF_ALU64\|BPF_OP(op)\|BPF_X, a, x, 0, 0})
	82	#define BPF_ALU32_REG(op, a, x) \
	83	((struct sock_filter_int) {BPF_ALU\|BPF_OP(op)\|BPF_X, a, x, 0, 0})
	84
	85	/* bpf_add\|sub\|...: a += imm, bpf_mov: a = imm */
	86	#define BPF_ALU64_IMM(op, a, imm) \
	87	((struct sock_filter_int) {BPF_ALU64\|BPF_OP(op)\|BPF_K, a, 0, 0, imm})
	88	#define BPF_ALU32_IMM(op, a, imm) \
	89	((struct sock_filter_int) {BPF_ALU\|BPF_OP(op)\|BPF_K, a, 0, 0, imm})
	90
	91	/* R0 = (uint ) (skb->data + off) */
	92	#define BPF_LD_ABS(size, off) \
	93	((struct sock_filter_int) {BPF_LD\|BPF_SIZE(size)\|BPF_ABS, 0, 0, 0, off})
	94
	95	/* R0 = (uint ) (skb->data + x + off) */
	96	#define BPF_LD_IND(size, x, off) \
	97	((struct sock_filter_int) {BPF_LD\|BPF_SIZE(size)\|BPF_IND, 0, x, 0, off})
	98
	99	/* a = (uint ) (x + off) */
	100	#define BPF_LDX_MEM(sz, a, x, off) \
	101	((struct sock_filter_int) {BPF_LDX\|BPF_SIZE(sz)\|BPF_MEM, a, x, off, 0})
	102
	103	/* if (a 'op' x) goto pc+off */
	104	#define BPF_JMP_REG(op, a, x, off) \
	105	((struct sock_filter_int) {BPF_JMP\|BPF_OP(op)\|BPF_X, a, x, off, 0})
	106
	107	/* if (a 'op' imm) goto pc+off */
	108	#define BPF_JMP_IMM(op, a, imm, off) \
	109	((struct sock_filter_int) {BPF_JMP\|BPF_OP(op)\|BPF_K, a, 0, off, imm})
	110
	111	#define BPF_EXIT_INSN() \
	112	((struct sock_filter_int) {BPF_JMP\|BPF_EXIT, 0, 0, 0, 0})
	113
	114	static inline int size_to_bpf(int size)
	115	{
	116	switch (size) {
	117	case 1:
	118	return BPF_B;
	119	case 2:
	120	return BPF_H;
	121	case 4:
	122	return BPF_W;
	123	case 8:
	124	return BPF_DW;
	125	default:
	126	return -EINVAL;
	127	}
	128	}
	129
30743837 DB	130	/* Macro to invoke filter function. */
30743837 DB	131	#define SK_RUN_FILTER(filter, ctx) (*filter->bpf_func)(ctx, filter->insnsi)
bd4cf0ed AS	132
	133	struct sock_filter_int {
	134	__u8 code; /* opcode */
	135	__u8 a_reg:4; /* dest register */
	136	__u8 x_reg:4; /* source register */
	137	__s16 off; /* signed offset */
	138	__s32 imm; /* signed immediate constant */
	139	};
	140
	141	#ifdef CONFIG_COMPAT
	142	/* A struct sock_filter is architecture independent. */
0c5fe1b4 WD	143	struct compat_sock_fprog {
0c5fe1b4 WD	144	u16 len;
bd4cf0ed	145	compat_uptr_t filter; /* struct sock_filter * */
0c5fe1b4 WD	146	};
	147	#endif
	148
a3ea269b DB	149	struct sock_fprog_kern {
	150	u16 len;
	151	struct sock_filter *filter;
	152	};
	153
792d4b5c HC	154	struct sk_buff;
792d4b5c HC	155	struct sock;
bd4cf0ed	156	struct seccomp_data;
792d4b5c	157
a3ea269b	158	struct sk_filter {
b715631f	159	atomic_t refcnt;
f8bbbfc3 DB	160	u32 jited:1, /* Is our filter JIT'ed? */
f8bbbfc3 DB	161	len:31; /* Number of filter blocks */
a3ea269b	162	struct sock_fprog_kern orig_prog; / Original BPF program */
d45ed4a4	163	struct rcu_head rcu;
0a14842f	164	unsigned int (bpf_func)(const struct sk_buff skb,
bd4cf0ed	165	const struct sock_filter_int *filter);
d45ed4a4	166	union {
bd4cf0ed AS	167	struct sock_filter insns[0];
bd4cf0ed AS	168	struct sock_filter_int insnsi[0];
d45ed4a4 AS	169	struct work_struct work;
d45ed4a4 AS	170	};
b715631f SH	171	};
b715631f SH	172
d45ed4a4	173	static inline unsigned int sk_filter_size(unsigned int proglen)
b715631f	174	{
d45ed4a4 AS	175	return max(sizeof(struct sk_filter),
d45ed4a4 AS	176	offsetof(struct sk_filter, insns[proglen]));
b715631f SH	177	}
b715631f SH	178
a3ea269b DB	179	#define sk_filter_proglen(fprog) \
	180	(fprog->len * sizeof(fprog->filter[0]))
	181
fbc907f0	182	int sk_filter(struct sock sk, struct sk_buff skb);
bd4cf0ed	183
5fe821a9 AS	184	void sk_filter_select_runtime(struct sk_filter *fp);
5fe821a9 AS	185	void sk_filter_free(struct sk_filter *fp);
bd4cf0ed AS	186
	187	int sk_convert_filter(struct sock_filter *prog, int len,
	188	struct sock_filter_int new_prog, int new_len);
a3ea269b	189
fbc907f0	190	int sk_unattached_filter_create(struct sk_filter **pfp,
b1fcd35c	191	struct sock_fprog_kern *fprog);
fbc907f0	192	void sk_unattached_filter_destroy(struct sk_filter *fp);
a3ea269b	193
fbc907f0 DB	194	int sk_attach_filter(struct sock_fprog fprog, struct sock sk);
fbc907f0 DB	195	int sk_detach_filter(struct sock *sk);
a3ea269b	196
fbc907f0 DB	197	int sk_chk_filter(struct sock_filter *filter, unsigned int flen);
	198	int sk_get_filter(struct sock sk, struct sock_filter __user filter,
	199	unsigned int len);
fbc907f0 DB	200
	201	void sk_filter_charge(struct sock sk, struct sk_filter fp);
	202	void sk_filter_uncharge(struct sock sk, struct sk_filter fp);
0a14842f	203
62258278 AS	204	u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
	205	void bpf_int_jit_compile(struct sk_filter *fp);
	206
34805931 DB	207	#define BPF_ANC BIT(15)
	208
	209	static inline u16 bpf_anc_helper(const struct sock_filter *ftest)
	210	{
	211	BUG_ON(ftest->code & BPF_ANC);
	212
	213	switch (ftest->code) {
	214	case BPF_LD \| BPF_W \| BPF_ABS:
	215	case BPF_LD \| BPF_H \| BPF_ABS:
	216	case BPF_LD \| BPF_B \| BPF_ABS:
	217	#define BPF_ANCILLARY(CODE) case SKF_AD_OFF + SKF_AD_##CODE: \
	218	return BPF_ANC \| SKF_AD_##CODE
	219	switch (ftest->k) {
	220	BPF_ANCILLARY(PROTOCOL);
	221	BPF_ANCILLARY(PKTTYPE);
	222	BPF_ANCILLARY(IFINDEX);
	223	BPF_ANCILLARY(NLATTR);
	224	BPF_ANCILLARY(NLATTR_NEST);
	225	BPF_ANCILLARY(MARK);
	226	BPF_ANCILLARY(QUEUE);
	227	BPF_ANCILLARY(HATYPE);
	228	BPF_ANCILLARY(RXHASH);
	229	BPF_ANCILLARY(CPU);
	230	BPF_ANCILLARY(ALU_XOR_X);
	231	BPF_ANCILLARY(VLAN_TAG);
	232	BPF_ANCILLARY(VLAN_TAG_PRESENT);
	233	BPF_ANCILLARY(PAY_OFFSET);
	234	BPF_ANCILLARY(RANDOM);
	235	}
	236	/* Fallthrough. */
	237	default:
	238	return ftest->code;
	239	}
	240	}
	241
0a14842f	242	#ifdef CONFIG_BPF_JIT
20074f35	243	#include <stdarg.h>
a691ce7f CG	244	#include <linux/linkage.h>
	245	#include <linux/printk.h>
	246
fbc907f0 DB	247	void bpf_jit_compile(struct sk_filter *fp);
fbc907f0 DB	248	void bpf_jit_free(struct sk_filter *fp);
79617801 DB	249
	250	static inline void bpf_jit_dump(unsigned int flen, unsigned int proglen,
	251	u32 pass, void *image)
	252	{
16495445	253	pr_err("flen=%u proglen=%u pass=%u image=%pK\n",
79617801 DB	254	flen, proglen, pass, image);
79617801 DB	255	if (image)
16495445	256	print_hex_dump(KERN_ERR, "JIT code: ", DUMP_PREFIX_OFFSET,
79617801 DB	257	16, 1, image, proglen, false);
79617801 DB	258	}
0a14842f	259	#else
d45ed4a4	260	#include <linux/slab.h>
34805931	261
0a14842f ED	262	static inline void bpf_jit_compile(struct sk_filter *fp)
	263	{
	264	}
34805931	265
0a14842f ED	266	static inline void bpf_jit_free(struct sk_filter *fp)
0a14842f ED	267	{
d45ed4a4	268	kfree(fp);
0a14842f	269	}
34805931	270	#endif /* CONFIG_BPF_JIT */
0a14842f	271
ea02f941 MS	272	static inline int bpf_tell_extensions(void)
ea02f941 MS	273	{
37692299	274	return SKF_AD_MAX;
ea02f941 MS	275	}
ea02f941 MS	276
1da177e4	277	#endif /* __LINUX_FILTER_H__ */