1 // SPDX-License-Identifier: GPL-2.0 2 /* Copyright (c) 2021 Google LLC. */ 3 4 #include <linux/bpf.h> 5 #include <bpf/bpf_helpers.h> 6 7 __u32 pid = 0; 8 9 char num_out[64] = {}; 10 long num_ret = 0; 11 12 char ip_out[64] = {}; 13 long ip_ret = 0; 14 15 char sym_out[64] = {}; 16 long sym_ret = 0; 17 18 char addr_out[64] = {}; 19 long addr_ret = 0; 20 21 char str_out[64] = {}; 22 long str_ret = 0; 23 24 char over_out[6] = {}; 25 long over_ret = 0; 26 27 char pad_out[10] = {}; 28 long pad_ret = 0; 29 30 char noarg_out[64] = {}; 31 long noarg_ret = 0; 32 33 long nobuf_ret = 0; 34 35 extern const void schedule __ksym; 36 37 SEC("raw_tp/sys_enter") 38 int handler(const void *ctx) 39 { 40 /* Convenient values to pretty-print */ 41 const __u8 ex_ipv4[] = {127, 0, 0, 1}; 42 const __u8 ex_ipv6[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1}; 43 static const char str1[] = "str1"; 44 static const char longstr[] = "longstr"; 45 46 if ((int)bpf_get_current_pid_tgid() != pid) 47 return 0; 48 49 /* Integer types */ 50 num_ret = BPF_SNPRINTF(num_out, sizeof(num_out), 51 "%d %u %x %li %llu %lX", 52 -8, 9, 150, -424242, 1337, 0xDABBAD00); 53 /* IP addresses */ 54 ip_ret = BPF_SNPRINTF(ip_out, sizeof(ip_out), "%pi4 %pI6", 55 &ex_ipv4, &ex_ipv6); 56 /* Symbol lookup formatting */ 57 sym_ret = BPF_SNPRINTF(sym_out, sizeof(sym_out), "%ps %pS %pB", 58 &schedule, &schedule, &schedule); 59 /* Kernel pointers */ 60 addr_ret = BPF_SNPRINTF(addr_out, sizeof(addr_out), "%pK %px %p", 61 0, 0xFFFF00000ADD4E55, 0xFFFF00000ADD4E55); 62 /* Strings and single-byte character embedding */ 63 str_ret = BPF_SNPRINTF(str_out, sizeof(str_out), "%s % 9c %+2c %-3c %04c %0c %+05s", 64 str1, 'a', 'b', 'c', 'd', 'e', longstr); 65 /* Overflow */ 66 over_ret = BPF_SNPRINTF(over_out, sizeof(over_out), "%%overflow"); 67 /* Padding of fixed width numbers */ 68 pad_ret = BPF_SNPRINTF(pad_out, sizeof(pad_out), "%5d %0900000X", 4, 4); 69 /* No args */ 70 noarg_ret = BPF_SNPRINTF(noarg_out, sizeof(noarg_out), "simple case"); 71 /* No buffer */ 72 nobuf_ret = BPF_SNPRINTF(NULL, 0, "only interested in length %d", 60); 73 74 return 0; 75 } 76 77 char _license[] SEC("license") = "GPL"; 78