Eric Lee / smarc-ti-linux-kernel

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samples/bpf/libbpf.c 2.67 KB
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3c731eba4   Alexei Starovoitov   bpf: mini eBPF li... 
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  /* eBPF mini library */
  #include <stdlib.h>
  #include <stdio.h>
  #include <linux/unistd.h>
  #include <unistd.h>
  #include <string.h>
  #include <linux/netlink.h>
  #include <linux/bpf.h>
  #include <errno.h>
03f4723ed   Alexei Starovoitov   samples: bpf: exa... 
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  #include <net/ethernet.h>
  #include <net/if.h>
  #include <linux/if_packet.h>
  #include <arpa/inet.h>
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  #include "libbpf.h"
  
  static __u64 ptr_to_u64(void *ptr)
  {
  	return (__u64) (unsigned long) ptr;
  }
  
  int bpf_create_map(enum bpf_map_type map_type, int key_size, int value_size,
  		   int max_entries)
  {
  	union bpf_attr attr = {
  		.map_type = map_type,
  		.key_size = key_size,
  		.value_size = value_size,
  		.max_entries = max_entries
  	};
  
  	return syscall(__NR_bpf, BPF_MAP_CREATE, &attr, sizeof(attr));
  }
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  int bpf_update_elem(int fd, void *key, void *value, unsigned long long flags)
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  {
  	union bpf_attr attr = {
  		.map_fd = fd,
  		.key = ptr_to_u64(key),
  		.value = ptr_to_u64(value),
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  		.flags = flags,
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  	};
  
  	return syscall(__NR_bpf, BPF_MAP_UPDATE_ELEM, &attr, sizeof(attr));
  }
  
  int bpf_lookup_elem(int fd, void *key, void *value)
  {
  	union bpf_attr attr = {
  		.map_fd = fd,
  		.key = ptr_to_u64(key),
  		.value = ptr_to_u64(value),
  	};
  
  	return syscall(__NR_bpf, BPF_MAP_LOOKUP_ELEM, &attr, sizeof(attr));
  }
  
  int bpf_delete_elem(int fd, void *key)
  {
  	union bpf_attr attr = {
  		.map_fd = fd,
  		.key = ptr_to_u64(key),
  	};
  
  	return syscall(__NR_bpf, BPF_MAP_DELETE_ELEM, &attr, sizeof(attr));
  }
  
  int bpf_get_next_key(int fd, void *key, void *next_key)
  {
  	union bpf_attr attr = {
  		.map_fd = fd,
  		.key = ptr_to_u64(key),
  		.next_key = ptr_to_u64(next_key),
  	};
  
  	return syscall(__NR_bpf, BPF_MAP_GET_NEXT_KEY, &attr, sizeof(attr));
  }
  
  #define ROUND_UP(x, n) (((x) + (n) - 1u) & ~((n) - 1u))
  
  char bpf_log_buf[LOG_BUF_SIZE];
  
  int bpf_prog_load(enum bpf_prog_type prog_type,
  		  const struct bpf_insn *insns, int prog_len,
  		  const char *license)
  {
  	union bpf_attr attr = {
  		.prog_type = prog_type,
  		.insns = ptr_to_u64((void *) insns),
  		.insn_cnt = prog_len / sizeof(struct bpf_insn),
  		.license = ptr_to_u64((void *) license),
  		.log_buf = ptr_to_u64(bpf_log_buf),
  		.log_size = LOG_BUF_SIZE,
  		.log_level = 1,
  	};
  
  	bpf_log_buf[0] = 0;
  
  	return syscall(__NR_bpf, BPF_PROG_LOAD, &attr, sizeof(attr));
  }
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  int open_raw_sock(const char *name)
  {
  	struct sockaddr_ll sll;
  	int sock;
  
  	sock = socket(PF_PACKET, SOCK_RAW | SOCK_NONBLOCK | SOCK_CLOEXEC, htons(ETH_P_ALL));
  	if (sock < 0) {
  		printf("cannot create raw socket
  ");
  		return -1;
  	}
  
  	memset(&sll, 0, sizeof(sll));
  	sll.sll_family = AF_PACKET;
  	sll.sll_ifindex = if_nametoindex(name);
  	sll.sll_protocol = htons(ETH_P_ALL);
  	if (bind(sock, (struct sockaddr *)&sll, sizeof(sll)) < 0) {
  		printf("bind to %s: %s
  ", name, strerror(errno));
  		close(sock);
  		return -1;
  	}
  
  	return sock;
  }