1 /* 2 * common eBPF ELF operations. 3 * 4 * Copyright (C) 2013-2015 Alexei Starovoitov <ast@kernel.org> 5 * Copyright (C) 2015 Wang Nan <wangnan0@huawei.com> 6 * Copyright (C) 2015 Huawei Inc. 7 */ 8 9 #include <stdlib.h> 10 #include <memory.h> 11 #include <unistd.h> 12 #include <asm/unistd.h> 13 #include <linux/bpf.h> 14 #include "bpf.h" 15 16 /* 17 * When building perf, unistd.h is overrided. __NR_bpf is 18 * required to be defined explicitly. 19 */ 20 #ifndef __NR_bpf 21 # if defined(__i386__) 22 # define __NR_bpf 357 23 # elif defined(__x86_64__) 24 # define __NR_bpf 321 25 # elif defined(__aarch64__) 26 # define __NR_bpf 280 27 # else 28 # error __NR_bpf not defined. libbpf does not support your arch. 29 # endif 30 #endif 31 32 static __u64 ptr_to_u64(void *ptr) 33 { 34 return (__u64) (unsigned long) ptr; 35 } 36 37 static int sys_bpf(enum bpf_cmd cmd, union bpf_attr *attr, 38 unsigned int size) 39 { 40 return syscall(__NR_bpf, cmd, attr, size); 41 } 42 43 int bpf_create_map(enum bpf_map_type map_type, int key_size, 44 int value_size, int max_entries) 45 { 46 union bpf_attr attr; 47 48 memset(&attr, '\0', sizeof(attr)); 49 50 attr.map_type = map_type; 51 attr.key_size = key_size; 52 attr.value_size = value_size; 53 attr.max_entries = max_entries; 54 55 return sys_bpf(BPF_MAP_CREATE, &attr, sizeof(attr)); 56 } 57 58 int bpf_load_program(enum bpf_prog_type type, struct bpf_insn *insns, 59 size_t insns_cnt, char *license, 60 u32 kern_version, char *log_buf, size_t log_buf_sz) 61 { 62 int fd; 63 union bpf_attr attr; 64 65 bzero(&attr, sizeof(attr)); 66 attr.prog_type = type; 67 attr.insn_cnt = (__u32)insns_cnt; 68 attr.insns = ptr_to_u64(insns); 69 attr.license = ptr_to_u64(license); 70 attr.log_buf = ptr_to_u64(NULL); 71 attr.log_size = 0; 72 attr.log_level = 0; 73 attr.kern_version = kern_version; 74 75 fd = sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr)); 76 if (fd >= 0 || !log_buf || !log_buf_sz) 77 return fd; 78 79 /* Try again with log */ 80 attr.log_buf = ptr_to_u64(log_buf); 81 attr.log_size = log_buf_sz; 82 attr.log_level = 1; 83 log_buf[0] = 0; 84 return sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr)); 85 } 86 87 int bpf_map_update_elem(int fd, void *key, void *value, 88 u64 flags) 89 { 90 union bpf_attr attr; 91 92 bzero(&attr, sizeof(attr)); 93 attr.map_fd = fd; 94 attr.key = ptr_to_u64(key); 95 attr.value = ptr_to_u64(value); 96 attr.flags = flags; 97 98 return sys_bpf(BPF_MAP_UPDATE_ELEM, &attr, sizeof(attr)); 99 } 100