systemd: move basic systemd library to shared/nm-utils
For better or worse, we already pull in large parts of systemd sources. I need a base64 decode implementation (because glib's g_base64_decode() cannot reject invalid encodings). Instead of coming up with my own or copy-paste if from somewhere, reuse systemd's unbase64mem(). But for that, make systemd's basic bits an independent static library first because I will need it in libnm-core. This doesn't really change anything except making "libnm-systemd-core.la" an indpendent static library that could be used from "libnm-core". We shall still be mindful about which internal code of systemd we use, and only access functionality that is exposed via "systemd/nm-sd-utils-shared.h".
This commit is contained in:
Thomas Haller
256
shared/systemd/src/basic/io-util.c
Normal file
256
shared/systemd/src/basic/io-util.c
Normal file
@@ -0,0 +1,256 @@
|
||||
/* SPDX-License-Identifier: LGPL-2.1+ */
|
||||
|
||||
#include "nm-sd-adapt-shared.h"
|
||||
|
||||
#include <errno.h>
|
||||
#include <limits.h>
|
||||
#include <poll.h>
|
||||
#include <stdio.h>
|
||||
#include <time.h>
|
||||
#include <unistd.h>
|
||||
|
||||
#include "io-util.h"
|
||||
#include "time-util.h"
|
||||
|
||||
int flush_fd(int fd) {
|
||||
struct pollfd pollfd = {
|
||||
.fd = fd,
|
||||
.events = POLLIN,
|
||||
};
|
||||
int count = 0;
|
||||
|
||||
/* Read from the specified file descriptor, until POLLIN is not set anymore, throwing away everything
|
||||
* read. Note that some file descriptors (notable IP sockets) will trigger POLLIN even when no data can be read
|
||||
* (due to IP packet checksum mismatches), hence this function is only safe to be non-blocking if the fd used
|
||||
* was set to non-blocking too. */
|
||||
|
||||
for (;;) {
|
||||
char buf[LINE_MAX];
|
||||
ssize_t l;
|
||||
int r;
|
||||
|
||||
r = poll(&pollfd, 1, 0);
|
||||
if (r < 0) {
|
||||
if (errno == EINTR)
|
||||
continue;
|
||||
|
||||
return -errno;
|
||||
|
||||
} else if (r == 0)
|
||||
return count;
|
||||
|
||||
l = read(fd, buf, sizeof(buf));
|
||||
if (l < 0) {
|
||||
|
||||
if (errno == EINTR)
|
||||
continue;
|
||||
|
||||
if (errno == EAGAIN)
|
||||
return count;
|
||||
|
||||
return -errno;
|
||||
} else if (l == 0)
|
||||
return count;
|
||||
|
||||
count += (int) l;
|
||||
}
|
||||
}
|
||||
|
||||
ssize_t loop_read(int fd, void *buf, size_t nbytes, bool do_poll) {
|
||||
uint8_t *p = buf;
|
||||
ssize_t n = 0;
|
||||
|
||||
assert(fd >= 0);
|
||||
assert(buf);
|
||||
|
||||
/* If called with nbytes == 0, let's call read() at least
|
||||
* once, to validate the operation */
|
||||
|
||||
if (nbytes > (size_t) SSIZE_MAX)
|
||||
return -EINVAL;
|
||||
|
||||
do {
|
||||
ssize_t k;
|
||||
|
||||
k = read(fd, p, nbytes);
|
||||
if (k < 0) {
|
||||
if (errno == EINTR)
|
||||
continue;
|
||||
|
||||
if (errno == EAGAIN && do_poll) {
|
||||
|
||||
/* We knowingly ignore any return value here,
|
||||
* and expect that any error/EOF is reported
|
||||
* via read() */
|
||||
|
||||
(void) fd_wait_for_event(fd, POLLIN, USEC_INFINITY);
|
||||
continue;
|
||||
}
|
||||
|
||||
return n > 0 ? n : -errno;
|
||||
}
|
||||
|
||||
if (k == 0)
|
||||
return n;
|
||||
|
||||
assert((size_t) k <= nbytes);
|
||||
|
||||
p += k;
|
||||
nbytes -= k;
|
||||
n += k;
|
||||
} while (nbytes > 0);
|
||||
|
||||
return n;
|
||||
}
|
||||
|
||||
int loop_read_exact(int fd, void *buf, size_t nbytes, bool do_poll) {
|
||||
ssize_t n;
|
||||
|
||||
n = loop_read(fd, buf, nbytes, do_poll);
|
||||
if (n < 0)
|
||||
return (int) n;
|
||||
if ((size_t) n != nbytes)
|
||||
return -EIO;
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
int loop_write(int fd, const void *buf, size_t nbytes, bool do_poll) {
|
||||
const uint8_t *p = buf;
|
||||
|
||||
assert(fd >= 0);
|
||||
assert(buf);
|
||||
|
||||
if (_unlikely_(nbytes > (size_t) SSIZE_MAX))
|
||||
return -EINVAL;
|
||||
|
||||
do {
|
||||
ssize_t k;
|
||||
|
||||
k = write(fd, p, nbytes);
|
||||
if (k < 0) {
|
||||
if (errno == EINTR)
|
||||
continue;
|
||||
|
||||
if (errno == EAGAIN && do_poll) {
|
||||
/* We knowingly ignore any return value here,
|
||||
* and expect that any error/EOF is reported
|
||||
* via write() */
|
||||
|
||||
(void) fd_wait_for_event(fd, POLLOUT, USEC_INFINITY);
|
||||
continue;
|
||||
}
|
||||
|
||||
return -errno;
|
||||
}
|
||||
|
||||
if (_unlikely_(nbytes > 0 && k == 0)) /* Can't really happen */
|
||||
return -EIO;
|
||||
|
||||
assert((size_t) k <= nbytes);
|
||||
|
||||
p += k;
|
||||
nbytes -= k;
|
||||
} while (nbytes > 0);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
int pipe_eof(int fd) {
|
||||
struct pollfd pollfd = {
|
||||
.fd = fd,
|
||||
.events = POLLIN|POLLHUP,
|
||||
};
|
||||
|
||||
int r;
|
||||
|
||||
r = poll(&pollfd, 1, 0);
|
||||
if (r < 0)
|
||||
return -errno;
|
||||
|
||||
if (r == 0)
|
||||
return 0;
|
||||
|
||||
return pollfd.revents & POLLHUP;
|
||||
}
|
||||
|
||||
int fd_wait_for_event(int fd, int event, usec_t t) {
|
||||
|
||||
struct pollfd pollfd = {
|
||||
.fd = fd,
|
||||
.events = event,
|
||||
};
|
||||
|
||||
struct timespec ts;
|
||||
int r;
|
||||
|
||||
r = ppoll(&pollfd, 1, t == USEC_INFINITY ? NULL : timespec_store(&ts, t), NULL);
|
||||
if (r < 0)
|
||||
return -errno;
|
||||
if (r == 0)
|
||||
return 0;
|
||||
|
||||
return pollfd.revents;
|
||||
}
|
||||
|
||||
static size_t nul_length(const uint8_t *p, size_t sz) {
|
||||
size_t n = 0;
|
||||
|
||||
while (sz > 0) {
|
||||
if (*p != 0)
|
||||
break;
|
||||
|
||||
n++;
|
||||
p++;
|
||||
sz--;
|
||||
}
|
||||
|
||||
return n;
|
||||
}
|
||||
|
||||
ssize_t sparse_write(int fd, const void *p, size_t sz, size_t run_length) {
|
||||
const uint8_t *q, *w, *e;
|
||||
ssize_t l;
|
||||
|
||||
q = w = p;
|
||||
e = q + sz;
|
||||
while (q < e) {
|
||||
size_t n;
|
||||
|
||||
n = nul_length(q, e - q);
|
||||
|
||||
/* If there are more than the specified run length of
|
||||
* NUL bytes, or if this is the beginning or the end
|
||||
* of the buffer, then seek instead of write */
|
||||
if ((n > run_length) ||
|
||||
(n > 0 && q == p) ||
|
||||
(n > 0 && q + n >= e)) {
|
||||
if (q > w) {
|
||||
l = write(fd, w, q - w);
|
||||
if (l < 0)
|
||||
return -errno;
|
||||
if (l != q -w)
|
||||
return -EIO;
|
||||
}
|
||||
|
||||
if (lseek(fd, n, SEEK_CUR) == (off_t) -1)
|
||||
return -errno;
|
||||
|
||||
q += n;
|
||||
w = q;
|
||||
} else if (n > 0)
|
||||
q += n;
|
||||
else
|
||||
q++;
|
||||
}
|
||||
|
||||
if (q > w) {
|
||||
l = write(fd, w, q - w);
|
||||
if (l < 0)
|
||||
return -errno;
|
||||
if (l != q - w)
|
||||
return -EIO;
|
||||
}
|
||||
|
||||
return q - (const uint8_t*) p;
|
||||
}
|
||||
Reference in New Issue
Block a user