diff options
| author | Michael Biebl <biebl@debian.org> | 2019-04-21 21:09:51 +0200 |
|---|---|---|
| committer | Michael Biebl <biebl@debian.org> | 2019-04-21 21:09:51 +0200 |
| commit | 85563b7fc7ec2cd21e38debb9b28db342e2e8e7c (patch) | |
| tree | cce7b0b02d28fae2df9fdf2c1804cacd1500f2d7 /shared/systemd/src/basic/errno-util.h | |
| parent | 9a6dcbf895f9da01768e64b73cec88c16157d91e (diff) | |
New upstream version 1.18.0 upstream/1.18.0
Diffstat (limited to 'shared/systemd/src/basic/errno-util.h')
| -rw-r--r-- | shared/systemd/src/basic/errno-util.h | 69 |
1 files changed, 69 insertions, 0 deletions
diff --git a/shared/systemd/src/basic/errno-util.h b/shared/systemd/src/basic/errno-util.h new file mode 100644 index 00000000..d7a5ea77 --- /dev/null +++ b/shared/systemd/src/basic/errno-util.h @@ -0,0 +1,69 @@ +/* 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); +} |