15232239991

Committed 24 May 2025 08:01PM UTC coverage: 72.053% (-0.02%) from 72.07%

Build # 15232239991

Build Type

push

github

Committed by

web-flow

Commit Message

docs: add man pages for sd_device_enumerator_[new,ref,unref,unrefp] (#37586)

For #20929.

Coverage Stats

299160 of 415197 relevant lines covered (72.05%)

703671.29 hits per line

Source File
Press 'n' to go to next uncovered line, 'b' for previous

81.82

/src/basic/errno-util.h

/* SPDX-License-Identifier: LGPL-2.1-or-later */
#pragma once

#include <errno.h>
#include <inttypes.h>
#include <string.h>

#include "assert-util.h"
#include "macro.h"

/* strerror(3) says that glibc uses a maximum length of 1024 bytes. */
#define ERRNO_BUF_LEN 1024

/* Note: the lifetime of the compound literal is the immediately surrounding block,
 * see C11 §6.5.2.5, and
 * https://stackoverflow.com/questions/34880638/compound-literal-lifetime-and-if-blocks
 *
 * Note that we use the GNU variant of strerror_r() here. */
#define STRERROR(errnum) strerror_r(ABS(errnum), (char[ERRNO_BUF_LEN]){}, ERRNO_BUF_LEN)

/* A helper to print an error message or message for functions that return 0 on EOF.
 * Note that we can't use ({ … }) to define a temporary variable, so errnum is
 * evaluated twice. */
#define STRERROR_OR_EOF(errnum) ((errnum) != 0 ? STRERROR(errnum) : "Unexpected EOF")

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)

#define LOCAL_ERRNO(value)                      \
        PROTECT_ERRNO;                          \
        errno = ABS(value)

#define return_with_errno(r, err)                     \
        do {                                          \
                errno = ABS(err);                     \
                return r;                             \
        } 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;
}

static inline int RET_NERRNO(int ret) {

        /* Helper to wrap system calls in to make them return negative errno errors. This brings system call
         * error handling in sync with how we usually handle errors in our own code, i.e. with immediate
         * returning of negative errno. Usage is like this:
         *
         *     …
         *     r = RET_NERRNO(unlink(t));
         *     …
         *
         * or
         *
         *     …
         *     fd = RET_NERRNO(open("/etc/fstab", O_RDONLY|O_CLOEXEC));
         *     …
         */

        if (ret < 0)
                return negative_errno();

        return ret;
}

/* Collect possible errors in <acc>, so that the first error can be returned.
 * Returns (possibly updated) <acc>. */
#define RET_GATHER(acc, err)                    \
        ({                                      \
                int *__a = &(acc), __e = (err); \
                if (*__a >= 0 && __e < 0)       \
                        *__a = __e;             \
                *__a;                           \
        })

static inline int errno_or_else(int fallback) {
        /* To be used when invoking library calls where errno handling is not defined clearly: we return
         * errno if it is set, and the specified error otherwise. The idea is that the caller initializes
         * errno to zero before doing an API call, and then uses this helper to retrieve a somewhat useful
         * error code */
        if (errno > 0)
                return -errno;

        return -ABS(fallback);
}

/* abs(3) says: Trying to take the absolute value of the most negative integer is not defined. */
#define _DEFINE_ABS_WRAPPER(name)                         \
        static inline bool ERRNO_IS_##name(intmax_t r) {  \
                if (r == INTMAX_MIN)                      \
                        return false;                     \
                return ERRNO_IS_NEG_##name(-ABS(r));      \
        }

/* For send()/recv() or read()/write(). */
static inline bool ERRNO_IS_NEG_TRANSIENT(intmax_t r) {
        return IN_SET(r,
                      -EAGAIN,
                      -EINTR);
}
_DEFINE_ABS_WRAPPER(TRANSIENT);

/* 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.
 *
 * Hint #3: When asynchronous connect() on TCP fails because the host never acknowledges a single packet,
 *          kernel tells us that with ETIMEDOUT, see tcp(7). */
static inline bool ERRNO_IS_NEG_DISCONNECT(intmax_t r) {
        return IN_SET(r,
                      -ECONNABORTED,
                      -ECONNREFUSED,
                      -ECONNRESET,
                      -EHOSTDOWN,
                      -EHOSTUNREACH,
                      -ENETDOWN,
                      -ENETRESET,
                      -ENETUNREACH,
                      -ENONET,
                      -ENOPROTOOPT,
                      -ENOTCONN,
                      -EPIPE,
                      -EPROTO,
                      -ESHUTDOWN,
                      -ETIMEDOUT);
}
_DEFINE_ABS_WRAPPER(DISCONNECT);

/* 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_NEG_ACCEPT_AGAIN(intmax_t r) {
        return ERRNO_IS_NEG_DISCONNECT(r) ||
                ERRNO_IS_NEG_TRANSIENT(r) ||
                r == -EOPNOTSUPP;
}
_DEFINE_ABS_WRAPPER(ACCEPT_AGAIN);

/* Resource exhaustion, could be our fault or general system trouble */
static inline bool ERRNO_IS_NEG_RESOURCE(intmax_t r) {
        return IN_SET(r,
                      -EMFILE,
                      -ENFILE,
                      -ENOMEM);
}
_DEFINE_ABS_WRAPPER(RESOURCE);

/* Seven different errors for "operation/system call/socket feature not supported" */
static inline bool ERRNO_IS_NEG_NOT_SUPPORTED(intmax_t r) {
        return IN_SET(r,
                      -EOPNOTSUPP,
                      -ENOTTY,
                      -ENOSYS,
                      -EAFNOSUPPORT,
                      -EPFNOSUPPORT,
                      -EPROTONOSUPPORT,
                      -ESOCKTNOSUPPORT,
                      -ENOPROTOOPT);
}
_DEFINE_ABS_WRAPPER(NOT_SUPPORTED);

/* ioctl() with unsupported command/arg might additionally return EINVAL */
static inline bool ERRNO_IS_NEG_IOCTL_NOT_SUPPORTED(intmax_t r) {
        return ERRNO_IS_NEG_NOT_SUPPORTED(r) || r == -EINVAL;
}
_DEFINE_ABS_WRAPPER(IOCTL_NOT_SUPPORTED);

/* Two different errors for access problems */
static inline bool ERRNO_IS_NEG_PRIVILEGE(intmax_t r) {
        return IN_SET(r,
                      -EACCES,
                      -EPERM);
}
_DEFINE_ABS_WRAPPER(PRIVILEGE);

/* Three different errors for "not enough disk space" */
static inline bool ERRNO_IS_NEG_DISK_SPACE(intmax_t r) {
        return IN_SET(r,
                      -ENOSPC,
                      -EDQUOT,
                      -EFBIG);
}
_DEFINE_ABS_WRAPPER(DISK_SPACE);

/* Three different errors for "this device does not quite exist" */
static inline bool ERRNO_IS_NEG_DEVICE_ABSENT(intmax_t r) {
        return IN_SET(r,
                      -ENODEV,
                      -ENXIO,
                      -ENOENT);
}
_DEFINE_ABS_WRAPPER(DEVICE_ABSENT);

/* Quite often we want to handle cases where the backing FS doesn't support extended attributes at all and
 * where it simply doesn't have the requested xattr the same way */
static inline bool ERRNO_IS_NEG_XATTR_ABSENT(intmax_t r) {
        return r == -ENODATA ||
                ERRNO_IS_NEG_NOT_SUPPORTED(r);
}
_DEFINE_ABS_WRAPPER(XATTR_ABSENT);

1	/* SPDX-License-Identifier: LGPL-2.1-or-later */
2	#pragma once
3
4	#include <errno.h>
5	#include <inttypes.h>
6	#include <string.h>
7
8	#include "assert-util.h"
9	#include "macro.h"
10
11	/* strerror(3) says that glibc uses a maximum length of 1024 bytes. */
12	#define ERRNO_BUF_LEN 1024
13
14	/* Note: the lifetime of the compound literal is the immediately surrounding block,
15	* see C11 §6.5.2.5, and
16	* https://stackoverflow.com/questions/34880638/compound-literal-lifetime-and-if-blocks
17	*
18	* Note that we use the GNU variant of strerror_r() here. */
19	#define STRERROR(errnum) strerror_r(ABS(errnum), (char[ERRNO_BUF_LEN]){}, ERRNO_BUF_LEN)
20
21	/* A helper to print an error message or message for functions that return 0 on EOF.
22	* Note that we can't use ({ … }) to define a temporary variable, so errnum is
23	* evaluated twice. */
24	#define STRERROR_OR_EOF(errnum) ((errnum) != 0 ? STRERROR(errnum) : "Unexpected EOF")
25
26	static inline void _reset_errno_(int *saved_errno) {	73,737,386✔
27	if (saved_errno < 0) / Invalidated by UNPROTECT_ERRNO? */	73,737,386✔
28	return;
29
30	errno = *saved_errno;	73,730,462✔
31	}
32
33	#define PROTECT_ERRNO \
34	_cleanup_(_reset_errno_) _unused_ int _saved_errno_ = errno
35
36	#define UNPROTECT_ERRNO \
37	do { \
38	errno = _saved_errno_; \
39	_saved_errno_ = -1; \
40	} while (false)
41
42	#define LOCAL_ERRNO(value) \
43	PROTECT_ERRNO; \
44	errno = ABS(value)
45
46	#define return_with_errno(r, err) \
47	do { \
48	errno = ABS(err); \
49	return r; \
50	} while (false)
51
52	static inline int negative_errno(void) {	2,772,524✔
53	/* This helper should be used to shut up gcc if you know 'errno' is
54	* negative. Instead of "return -errno;", use "return negative_errno();"
55	* It will suppress bogus gcc warnings in case it assumes 'errno' might
56	* be 0 and thus the caller's error-handling might not be triggered. */
57	assert_return(errno > 0, -EINVAL);	2,772,524✔
58	return -errno;	2,772,524✔
59	}
60
61	static inline int RET_NERRNO(int ret) {	39,327,682✔
62
63	/* Helper to wrap system calls in to make them return negative errno errors. This brings system call
64	* error handling in sync with how we usually handle errors in our own code, i.e. with immediate
65	* returning of negative errno. Usage is like this:
66	*
67	* …
68	* r = RET_NERRNO(unlink(t));
69	* …
70	*
71	* or
72	*
73	* …
74	* fd = RET_NERRNO(open("/etc/fstab", O_RDONLY\|O_CLOEXEC));
75	* …
76	*/
77
78	if (ret < 0)	39,327,682✔
79	return negative_errno();	2,772,472✔
80
81	return ret;
82	}
83
84	/* Collect possible errors in <acc>, so that the first error can be returned.
85	* Returns (possibly updated) <acc>. */
86	#define RET_GATHER(acc, err) \
87	({ \
88	int *__a = &(acc), __e = (err); \
89	if (*__a >= 0 && __e < 0) \
90	*__a = __e; \
91	*__a; \
92	})
93
94	static inline int errno_or_else(int fallback) {	71,664✔
95	/* To be used when invoking library calls where errno handling is not defined clearly: we return
96	* errno if it is set, and the specified error otherwise. The idea is that the caller initializes
97	* errno to zero before doing an API call, and then uses this helper to retrieve a somewhat useful
98	* error code */
99	if (errno > 0)	71,664✔
100	return -errno;	25✔
101
102	return -ABS(fallback);
103	}
104
105	/* abs(3) says: Trying to take the absolute value of the most negative integer is not defined. */
106	#define _DEFINE_ABS_WRAPPER(name) \
107	static inline bool ERRNO_IS_##name(intmax_t r) { \
108	if (r == INTMAX_MIN) \
109	return false; \
110	return ERRNO_IS_NEG_##name(-ABS(r)); \
111	}
112
113	/* For send()/recv() or read()/write(). */
114	static inline bool ERRNO_IS_NEG_TRANSIENT(intmax_t r) {	3,598,901✔
115	return IN_SET(r,	3,598,714✔
116	-EAGAIN,
117	-EINTR);
118	}
119	_DEFINE_ABS_WRAPPER(TRANSIENT);	5,759✔
120
121	/* Hint #1: ENETUNREACH happens if we try to connect to "non-existing" special IP addresses, such as ::5.
122	*
123	* Hint #2: The kernel sends e.g., EHOSTUNREACH or ENONET to userspace in some ICMP error cases. See the
124	* icmp_err_convert[] in net/ipv4/icmp.c in the kernel sources.
125	*
126	* Hint #3: When asynchronous connect() on TCP fails because the host never acknowledges a single packet,
127	* kernel tells us that with ETIMEDOUT, see tcp(7). */
128	static inline bool ERRNO_IS_NEG_DISCONNECT(intmax_t r) {	654,963✔
129	return IN_SET(r,	654,963✔
130	-ECONNABORTED,
131	-ECONNREFUSED,
132	-ECONNRESET,
133	-EHOSTDOWN,
134	-EHOSTUNREACH,
135	-ENETDOWN,
136	-ENETRESET,
137	-ENETUNREACH,
138	-ENONET,
139	-ENOPROTOOPT,
140	-ENOTCONN,
141	-EPIPE,
142	-EPROTO,
143	-ESHUTDOWN,
144	-ETIMEDOUT);
145	}
146	_DEFINE_ABS_WRAPPER(DISCONNECT);	2,752✔
147
148	/* Transient errors we might get on accept() that we should ignore. As per error handling comment in
149	* the accept(2) man page. */
150	static inline bool ERRNO_IS_NEG_ACCEPT_AGAIN(intmax_t r) {	×
151	return ERRNO_IS_NEG_DISCONNECT(r) \|\|	×
152	ERRNO_IS_NEG_TRANSIENT(r) \|\|	×
153	r == -EOPNOTSUPP;
154	}
155	_DEFINE_ABS_WRAPPER(ACCEPT_AGAIN);	×
156
157	/* Resource exhaustion, could be our fault or general system trouble */
158	static inline bool ERRNO_IS_NEG_RESOURCE(intmax_t r) {	1,301✔
159	return IN_SET(r,	1,301✔
160	-EMFILE,
161	-ENFILE,
162	-ENOMEM);
163	}
164	_DEFINE_ABS_WRAPPER(RESOURCE);	×
165
166	/* Seven different errors for "operation/system call/socket feature not supported" */
167	static inline bool ERRNO_IS_NEG_NOT_SUPPORTED(intmax_t r) {	302,213✔
168	return IN_SET(r,	293,735✔
169	-EOPNOTSUPP,
170	-ENOTTY,
171	-ENOSYS,
172	-EAFNOSUPPORT,
173	-EPFNOSUPPORT,
174	-EPROTONOSUPPORT,
175	-ESOCKTNOSUPPORT,
176	-ENOPROTOOPT);
177	}
178	_DEFINE_ABS_WRAPPER(NOT_SUPPORTED);	205,940✔
179
180	/* ioctl() with unsupported command/arg might additionally return EINVAL */
181	static inline bool ERRNO_IS_NEG_IOCTL_NOT_SUPPORTED(intmax_t r) {	3,207✔
182	return ERRNO_IS_NEG_NOT_SUPPORTED(r) \|\| r == -EINVAL;	3,207✔
183	}
184	_DEFINE_ABS_WRAPPER(IOCTL_NOT_SUPPORTED);	3,207✔
185
186	/* Two different errors for access problems */
187	static inline bool ERRNO_IS_NEG_PRIVILEGE(intmax_t r) {	700,833✔
188	return IN_SET(r,	697,032✔
189	-EACCES,
190	-EPERM);
191	}
192	_DEFINE_ABS_WRAPPER(PRIVILEGE);	3,869✔
193
194	/* Three different errors for "not enough disk space" */
195	static inline bool ERRNO_IS_NEG_DISK_SPACE(intmax_t r) {	×
196	return IN_SET(r,	×
197	-ENOSPC,
198	-EDQUOT,
199	-EFBIG);
200	}
201	_DEFINE_ABS_WRAPPER(DISK_SPACE);	×
202
203	/* Three different errors for "this device does not quite exist" */
204	static inline bool ERRNO_IS_NEG_DEVICE_ABSENT(intmax_t r) {	1,217,073✔
205	return IN_SET(r,	1,217,073✔
206	-ENODEV,
207	-ENXIO,
208	-ENOENT);
209	}
210	_DEFINE_ABS_WRAPPER(DEVICE_ABSENT);	137,860✔
211
212	/* Quite often we want to handle cases where the backing FS doesn't support extended attributes at all and
213	* where it simply doesn't have the requested xattr the same way */
214	static inline bool ERRNO_IS_NEG_XATTR_ABSENT(intmax_t r) {	42,282✔
215	return r == -ENODATA \|\|	42,282✔
216	ERRNO_IS_NEG_NOT_SUPPORTED(r);	42,282✔
217	}
218	_DEFINE_ABS_WRAPPER(XATTR_ABSENT);	31,994✔

systemd / systemd / 15232239991

Source File Press 'n' to go to next uncovered line, 'b' for previous

Source File
Press 'n' to go to next uncovered line, 'b' for previous