230 lines
5.5 KiB
C
230 lines
5.5 KiB
C
/*
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* Linux Socket Filter Data Structures
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*/
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#ifndef __LINUX_FILTER_H__
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#define __LINUX_FILTER_H__
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#include <linux/atomic.h>
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#include <linux/compat.h>
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#include <linux/workqueue.h>
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#include <uapi/linux/filter.h>
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/* Internally used and optimized filter representation with extended
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* instruction set based on top of classic BPF.
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*/
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/* instruction classes */
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#define BPF_ALU64 0x07 /* alu mode in double word width */
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/* ld/ldx fields */
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#define BPF_DW 0x18 /* double word */
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#define BPF_XADD 0xc0 /* exclusive add */
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/* alu/jmp fields */
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#define BPF_MOV 0xb0 /* mov reg to reg */
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#define BPF_ARSH 0xc0 /* sign extending arithmetic shift right */
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/* change endianness of a register */
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#define BPF_END 0xd0 /* flags for endianness conversion: */
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#define BPF_TO_LE 0x00 /* convert to little-endian */
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#define BPF_TO_BE 0x08 /* convert to big-endian */
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#define BPF_FROM_LE BPF_TO_LE
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#define BPF_FROM_BE BPF_TO_BE
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#define BPF_JNE 0x50 /* jump != */
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#define BPF_JSGT 0x60 /* SGT is signed '>', GT in x86 */
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#define BPF_JSGE 0x70 /* SGE is signed '>=', GE in x86 */
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#define BPF_CALL 0x80 /* function call */
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#define BPF_EXIT 0x90 /* function return */
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/* BPF has 10 general purpose 64-bit registers and stack frame. */
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#define MAX_BPF_REG 11
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/* BPF program can access up to 512 bytes of stack space. */
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#define MAX_BPF_STACK 512
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/* Arg1, context and stack frame pointer register positions. */
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#define ARG1_REG 1
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#define CTX_REG 6
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#define FP_REG 10
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struct sock_filter_int {
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__u8 code; /* opcode */
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__u8 a_reg:4; /* dest register */
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__u8 x_reg:4; /* source register */
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__s16 off; /* signed offset */
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__s32 imm; /* signed immediate constant */
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};
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#ifdef CONFIG_COMPAT
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/* A struct sock_filter is architecture independent. */
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struct compat_sock_fprog {
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u16 len;
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compat_uptr_t filter; /* struct sock_filter * */
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};
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#endif
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struct sock_fprog_kern {
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u16 len;
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struct sock_filter *filter;
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};
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struct sk_buff;
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struct sock;
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struct seccomp_data;
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struct sk_filter {
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atomic_t refcnt;
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u32 jited:1, /* Is our filter JIT'ed? */
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len:31; /* Number of filter blocks */
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struct sock_fprog_kern *orig_prog; /* Original BPF program */
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struct rcu_head rcu;
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unsigned int (*bpf_func)(const struct sk_buff *skb,
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const struct sock_filter_int *filter);
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union {
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struct sock_filter insns[0];
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struct sock_filter_int insnsi[0];
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struct work_struct work;
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};
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};
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static inline unsigned int sk_filter_size(unsigned int proglen)
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{
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return max(sizeof(struct sk_filter),
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offsetof(struct sk_filter, insns[proglen]));
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}
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#define sk_filter_proglen(fprog) \
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(fprog->len * sizeof(fprog->filter[0]))
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#define SK_RUN_FILTER(filter, ctx) \
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(*filter->bpf_func)(ctx, filter->insnsi)
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int sk_filter(struct sock *sk, struct sk_buff *skb);
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u32 sk_run_filter_int_seccomp(const struct seccomp_data *ctx,
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const struct sock_filter_int *insni);
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u32 sk_run_filter_int_skb(const struct sk_buff *ctx,
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const struct sock_filter_int *insni);
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int sk_convert_filter(struct sock_filter *prog, int len,
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struct sock_filter_int *new_prog, int *new_len);
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int sk_unattached_filter_create(struct sk_filter **pfp,
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struct sock_fprog *fprog);
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void sk_unattached_filter_destroy(struct sk_filter *fp);
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int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk);
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int sk_detach_filter(struct sock *sk);
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int sk_chk_filter(struct sock_filter *filter, unsigned int flen);
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int sk_get_filter(struct sock *sk, struct sock_filter __user *filter,
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unsigned int len);
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void sk_decode_filter(struct sock_filter *filt, struct sock_filter *to);
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void sk_filter_charge(struct sock *sk, struct sk_filter *fp);
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void sk_filter_uncharge(struct sock *sk, struct sk_filter *fp);
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#ifdef CONFIG_BPF_JIT
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#include <stdarg.h>
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#include <linux/linkage.h>
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#include <linux/printk.h>
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void bpf_jit_compile(struct sk_filter *fp);
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void bpf_jit_free(struct sk_filter *fp);
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static inline void bpf_jit_dump(unsigned int flen, unsigned int proglen,
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u32 pass, void *image)
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{
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pr_err("flen=%u proglen=%u pass=%u image=%pK\n",
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flen, proglen, pass, image);
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if (image)
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print_hex_dump(KERN_ERR, "JIT code: ", DUMP_PREFIX_OFFSET,
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16, 1, image, proglen, false);
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}
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#else
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#include <linux/slab.h>
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static inline void bpf_jit_compile(struct sk_filter *fp)
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{
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}
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static inline void bpf_jit_free(struct sk_filter *fp)
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{
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kfree(fp);
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}
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#endif
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static inline int bpf_tell_extensions(void)
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{
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return SKF_AD_MAX;
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}
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enum {
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BPF_S_RET_K = 1,
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BPF_S_RET_A,
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BPF_S_ALU_ADD_K,
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BPF_S_ALU_ADD_X,
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BPF_S_ALU_SUB_K,
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BPF_S_ALU_SUB_X,
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BPF_S_ALU_MUL_K,
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BPF_S_ALU_MUL_X,
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BPF_S_ALU_DIV_X,
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BPF_S_ALU_MOD_K,
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BPF_S_ALU_MOD_X,
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BPF_S_ALU_AND_K,
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BPF_S_ALU_AND_X,
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BPF_S_ALU_OR_K,
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BPF_S_ALU_OR_X,
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BPF_S_ALU_XOR_K,
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BPF_S_ALU_XOR_X,
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BPF_S_ALU_LSH_K,
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BPF_S_ALU_LSH_X,
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BPF_S_ALU_RSH_K,
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BPF_S_ALU_RSH_X,
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BPF_S_ALU_NEG,
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BPF_S_LD_W_ABS,
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BPF_S_LD_H_ABS,
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BPF_S_LD_B_ABS,
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BPF_S_LD_W_LEN,
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BPF_S_LD_W_IND,
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BPF_S_LD_H_IND,
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BPF_S_LD_B_IND,
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BPF_S_LD_IMM,
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BPF_S_LDX_W_LEN,
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BPF_S_LDX_B_MSH,
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BPF_S_LDX_IMM,
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BPF_S_MISC_TAX,
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BPF_S_MISC_TXA,
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BPF_S_ALU_DIV_K,
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BPF_S_LD_MEM,
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BPF_S_LDX_MEM,
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BPF_S_ST,
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BPF_S_STX,
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BPF_S_JMP_JA,
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BPF_S_JMP_JEQ_K,
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BPF_S_JMP_JEQ_X,
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BPF_S_JMP_JGE_K,
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BPF_S_JMP_JGE_X,
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BPF_S_JMP_JGT_K,
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BPF_S_JMP_JGT_X,
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BPF_S_JMP_JSET_K,
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BPF_S_JMP_JSET_X,
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/* Ancillary data */
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BPF_S_ANC_PROTOCOL,
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BPF_S_ANC_PKTTYPE,
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BPF_S_ANC_IFINDEX,
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BPF_S_ANC_NLATTR,
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BPF_S_ANC_NLATTR_NEST,
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BPF_S_ANC_MARK,
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BPF_S_ANC_QUEUE,
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BPF_S_ANC_HATYPE,
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BPF_S_ANC_RXHASH,
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BPF_S_ANC_CPU,
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BPF_S_ANC_ALU_XOR_X,
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BPF_S_ANC_SECCOMP_LD_W,
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BPF_S_ANC_VLAN_TAG,
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BPF_S_ANC_VLAN_TAG_PRESENT,
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BPF_S_ANC_PAY_OFFSET,
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};
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#endif /* __LINUX_FILTER_H__ */
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