530b2c8619
Usage: $ sudo ./sockex3 IP src.port -> dst.port bytes packets 127.0.0.1.42010 -> 127.0.0.1.12865 1568 8 127.0.0.1.59526 -> 127.0.0.1.33778 11422636 173070 127.0.0.1.33778 -> 127.0.0.1.59526 11260224828 341974 127.0.0.1.12865 -> 127.0.0.1.42010 1832 12 IP src.port -> dst.port bytes packets 127.0.0.1.42010 -> 127.0.0.1.12865 1568 8 127.0.0.1.59526 -> 127.0.0.1.33778 23198092 351486 127.0.0.1.33778 -> 127.0.0.1.59526 22972698518 698616 127.0.0.1.12865 -> 127.0.0.1.42010 1832 12 this example is similar to sockex2 in a way that it accumulates per-flow statistics, but it does packet parsing differently. sockex2 inlines full packet parser routine into single bpf program. This sockex3 example have 4 independent programs that parse vlan, mpls, ip, ipv6 and one main program that starts the process. bpf_tail_call() mechanism allows each program to be small and be called on demand potentially multiple times, so that many vlan, mpls, ip in ip, gre encapsulations can be parsed. These and other protocol parsers can be added or removed at runtime. TLVs can be parsed in similar manner. Note, tail_call_cnt dynamic check limits the number of tail calls to 32. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
58 lines
2.1 KiB
C
58 lines
2.1 KiB
C
#ifndef __BPF_HELPERS_H
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#define __BPF_HELPERS_H
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/* helper macro to place programs, maps, license in
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* different sections in elf_bpf file. Section names
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* are interpreted by elf_bpf loader
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*/
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#define SEC(NAME) __attribute__((section(NAME), used))
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/* helper functions called from eBPF programs written in C */
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static void *(*bpf_map_lookup_elem)(void *map, void *key) =
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(void *) BPF_FUNC_map_lookup_elem;
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static int (*bpf_map_update_elem)(void *map, void *key, void *value,
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unsigned long long flags) =
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(void *) BPF_FUNC_map_update_elem;
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static int (*bpf_map_delete_elem)(void *map, void *key) =
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(void *) BPF_FUNC_map_delete_elem;
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static int (*bpf_probe_read)(void *dst, int size, void *unsafe_ptr) =
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(void *) BPF_FUNC_probe_read;
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static unsigned long long (*bpf_ktime_get_ns)(void) =
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(void *) BPF_FUNC_ktime_get_ns;
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static int (*bpf_trace_printk)(const char *fmt, int fmt_size, ...) =
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(void *) BPF_FUNC_trace_printk;
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static void (*bpf_tail_call)(void *ctx, void *map, int index) =
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(void *) BPF_FUNC_tail_call;
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static unsigned long long (*bpf_get_smp_processor_id)(void) =
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(void *) BPF_FUNC_get_smp_processor_id;
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/* llvm builtin functions that eBPF C program may use to
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* emit BPF_LD_ABS and BPF_LD_IND instructions
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*/
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struct sk_buff;
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unsigned long long load_byte(void *skb,
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unsigned long long off) asm("llvm.bpf.load.byte");
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unsigned long long load_half(void *skb,
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unsigned long long off) asm("llvm.bpf.load.half");
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unsigned long long load_word(void *skb,
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unsigned long long off) asm("llvm.bpf.load.word");
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/* a helper structure used by eBPF C program
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* to describe map attributes to elf_bpf loader
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*/
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struct bpf_map_def {
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unsigned int type;
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unsigned int key_size;
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unsigned int value_size;
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unsigned int max_entries;
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};
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static int (*bpf_skb_store_bytes)(void *ctx, int off, void *from, int len, int flags) =
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(void *) BPF_FUNC_skb_store_bytes;
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static int (*bpf_l3_csum_replace)(void *ctx, int off, int from, int to, int flags) =
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(void *) BPF_FUNC_l3_csum_replace;
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static int (*bpf_l4_csum_replace)(void *ctx, int off, int from, int to, int flags) =
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(void *) BPF_FUNC_l4_csum_replace;
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#endif
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