Systemd/src/basic/errno-util.h

70 lines
2.4 KiB
C

/* SPDX-License-Identifier: LGPL-2.1+ */
#pragma once
#include "macro.h"
static inline void _reset_errno_(int *saved_errno) {
if (*saved_errno < 0) /* Invalidated by UNPROTECT_ERRNO? */
return;
errno = *saved_errno;
}
#define PROTECT_ERRNO \
_cleanup_(_reset_errno_) _unused_ int _saved_errno_ = errno
#define UNPROTECT_ERRNO \
do { \
errno = _saved_errno_; \
_saved_errno_ = -1; \
} while (false)
static inline int negative_errno(void) {
/* This helper should be used to shut up gcc if you know 'errno' is
* negative. Instead of "return -errno;", use "return negative_errno();"
* It will suppress bogus gcc warnings in case it assumes 'errno' might
* be 0 and thus the caller's error-handling might not be triggered. */
assert_return(errno > 0, -EINVAL);
return -errno;
}
/* Hint #1: ENETUNREACH happens if we try to connect to "non-existing" special IP addresses, such as ::5.
*
* Hint #2: The kernel sends e.g., EHOSTUNREACH or ENONET to userspace in some ICMP error cases. See the
* icmp_err_convert[] in net/ipv4/icmp.c in the kernel sources */
static inline bool ERRNO_IS_DISCONNECT(int r) {
return IN_SET(abs(r),
ECONNABORTED,
ECONNREFUSED,
ECONNRESET,
EHOSTDOWN,
EHOSTUNREACH,
ENETDOWN,
ENETRESET,
ENETUNREACH,
ENONET,
ENOPROTOOPT,
ENOTCONN,
EPIPE,
EPROTO,
ESHUTDOWN);
}
/* Transient errors we might get on accept() that we should ignore. As per error handling comment in
* the accept(2) man page. */
static inline bool ERRNO_IS_ACCEPT_AGAIN(int r) {
return ERRNO_IS_DISCONNECT(r) ||
IN_SET(abs(r),
EAGAIN,
EINTR,
EOPNOTSUPP);
}
/* Resource exhaustion, could be our fault or general system trouble */
static inline bool ERRNO_IS_RESOURCE(int r) {
return IN_SET(abs(r),
EMFILE,
ENFILE,
ENOMEM);
}