tools/lib/bpf/libbpf_errno.c

   1 // SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
   2
   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  * Copyright (C) 2017 Nicira, Inc.
   8  */
   9
  10 #undef _GNU_SOURCE
  11 #include <stdio.h>
  12 #include <string.h>
  13
  14 #include "libbpf.h"
  15 #include "libbpf_internal.h"
  16
  17 /* make sure libbpf doesn't use kernel-only integer typedefs */
  18 #pragma GCC poison u8 u16 u32 u64 s8 s16 s32 s64
  19
  20 #define ERRNO_OFFSET(e)         ((e) - __LIBBPF_ERRNO__START)
  21 #define ERRCODE_OFFSET(c)       ERRNO_OFFSET(LIBBPF_ERRNO__##c)
  22 #define NR_ERRNO        (__LIBBPF_ERRNO__END - __LIBBPF_ERRNO__START)
  23
  24 static const char *libbpf_strerror_table[NR_ERRNO] = {
  25         [ERRCODE_OFFSET(LIBELF)]        = "Something wrong in libelf",
  26         [ERRCODE_OFFSET(FORMAT)]        = "BPF object format invalid",
  27         [ERRCODE_OFFSET(KVERSION)]      = "'version' section incorrect or lost",
  28         [ERRCODE_OFFSET(ENDIAN)]        = "Endian mismatch",
  29         [ERRCODE_OFFSET(INTERNAL)]      = "Internal error in libbpf",
  30         [ERRCODE_OFFSET(RELOC)]         = "Relocation failed",
  31         [ERRCODE_OFFSET(VERIFY)]        = "Kernel verifier blocks program loading",
  32         [ERRCODE_OFFSET(PROG2BIG)]      = "Program too big",
  33         [ERRCODE_OFFSET(KVER)]          = "Incorrect kernel version",
  34         [ERRCODE_OFFSET(PROGTYPE)]      = "Kernel doesn't support this program type",
  35         [ERRCODE_OFFSET(WRNGPID)]       = "Wrong pid in netlink message",
  36         [ERRCODE_OFFSET(INVSEQ)]        = "Invalid netlink sequence",
  37         [ERRCODE_OFFSET(NLPARSE)]       = "Incorrect netlink message parsing",
  38 };
  39
  40 int libbpf_strerror(int err, char *buf, size_t size)
  41 {
  42         int ret;
  43
  44         if (!buf || !size)
  45                 return libbpf_err(-EINVAL);
  46
  47         err = err > 0 ? err : -err;
  48
  49         if (err < __LIBBPF_ERRNO__START) {
  50                 ret = strerror_r(err, buf, size);
  51                 buf[size - 1] = '\0';
  52                 return libbpf_err_errno(ret);
  53         }
  54
  55         if (err < __LIBBPF_ERRNO__END) {
  56                 const char *msg;
  57
  58                 msg = libbpf_strerror_table[ERRNO_OFFSET(err)];
  59                 ret = snprintf(buf, size, "%s", msg);
  60                 buf[size - 1] = '\0';
  61                 /* The length of the buf and msg is positive.
  62                  * A negative number may be returned only when the
  63                  * size exceeds INT_MAX. Not likely to appear.
  64                  */
  65                 if (ret >= size)
  66                         return libbpf_err(-ERANGE);
  67                 return 0;
  68         }
  69
  70         ret = snprintf(buf, size, "Unknown libbpf error %d", err);
  71         buf[size - 1] = '\0';
  72         if (ret >= size)
  73                 return libbpf_err(-ERANGE);
  74         return libbpf_err(-ENOENT);
  75 }