}
ssize_t loop_read(int fd, void *buf, size_t nbytes, bool do_poll) {
- uint8_t *p;
+ uint8_t *p = buf;
ssize_t n = 0;
assert(fd >= 0);
assert(buf);
- p = buf;
-
while (nbytes > 0) {
ssize_t k;
- if ((k = read(fd, p, nbytes)) <= 0) {
-
- if (k < 0 && errno == EINTR)
- continue;
-
- if (k < 0 && errno == EAGAIN && do_poll) {
- struct pollfd pollfd = {
- .fd = fd,
- .events = POLLIN,
- };
-
- if (poll(&pollfd, 1, -1) < 0) {
- if (errno == EINTR)
- continue;
+ k = read(fd, p, nbytes);
+ if (k < 0 && errno == EINTR)
+ continue;
- return n > 0 ? n : -errno;
- }
+ if (k < 0 && errno == EAGAIN && do_poll) {
- /* We knowingly ignore the revents value here,
- * and expect that any error/EOF is reported
- * via read()/write()
- */
+ /* We knowingly ignore any return value here,
+ * and expect that any error/EOF is reported
+ * via read() */
- continue;
- }
+ fd_wait_for_event(fd, POLLIN, (usec_t) -1);
+ continue;
+ }
+ if (k <= 0)
return n > 0 ? n : (k < 0 ? -errno : 0);
- }
p += k;
nbytes -= k;
}
ssize_t loop_write(int fd, const void *buf, size_t nbytes, bool do_poll) {
- const uint8_t *p;
+ const uint8_t *p = buf;
ssize_t n = 0;
assert(fd >= 0);
assert(buf);
- p = buf;
-
while (nbytes > 0) {
ssize_t k;
k = write(fd, p, nbytes);
- if (k <= 0) {
-
- if (k < 0 && errno == EINTR)
- continue;
-
- if (k < 0 && errno == EAGAIN && do_poll) {
- struct pollfd pollfd = {
- .fd = fd,
- .events = POLLOUT,
- };
+ if (k < 0 && errno == EINTR)
+ continue;
- if (poll(&pollfd, 1, -1) < 0) {
- if (errno == EINTR)
- continue;
+ if (k < 0 && errno == EAGAIN && do_poll) {
- return n > 0 ? n : -errno;
- }
+ /* We knowingly ignore any return value here,
+ * and expect that any error/EOF is reported
+ * via write() */
- /* We knowingly ignore the revents value here,
- * and expect that any error/EOF is reported
- * via read()/write()
- */
-
- continue;
- }
+ fd_wait_for_event(fd, POLLOUT, (usec_t) -1);
+ continue;
+ }
+ if (k <= 0)
return n > 0 ? n : (k < 0 ? -errno : 0);
- }
p += k;
nbytes -= k;
return dir;
}
-void random_bytes(void *p, size_t n) {
- static bool srand_called = false;
+int dev_urandom(void *p, size_t n) {
_cleanup_close_ int fd;
ssize_t k;
- uint8_t *q;
fd = open("/dev/urandom", O_RDONLY|O_CLOEXEC|O_NOCTTY);
if (fd < 0)
- goto fallback;
+ return errno == ENOENT ? -ENOSYS : -errno;
k = loop_read(fd, p, n, true);
- if (k < 0 || (size_t) k != n)
- goto fallback;
+ if (k < 0)
+ return (int) k;
+ if ((size_t) k != n)
+ return -EIO;
- return;
+ return 0;
+}
-fallback:
+void random_bytes(void *p, size_t n) {
+ static bool srand_called = false;
+ uint8_t *q;
+ int r;
+
+ r = dev_urandom(p, n);
+ if (r >= 0)
+ return;
+
+ /* If some idiot made /dev/urandom unavailable to us, he'll
+ * get a PRNG instead. */
if (!srand_called) {
+ unsigned x = 0;
#ifdef HAVE_SYS_AUXV_H
/* The kernel provides us with a bit of entropy in
auxv = (void*) getauxval(AT_RANDOM);
if (auxv)
- srand(*(unsigned*) auxv);
- else
+ x ^= *(unsigned*) auxv;
#endif
- srand(time(NULL) + gettid());
+ x ^= (unsigned) now(CLOCK_REALTIME);
+ x ^= (unsigned) gettid();
+
+ srand(x);
srand_called = true;
}
- /* If some idiot made /dev/urandom unavailable to us, he'll
- * get a PRNG instead. */
for (q = p; q < (uint8_t*) p + n; q ++)
*q = rand();
}
}
int pipe_eof(int fd) {
- int r;
struct pollfd pollfd = {
.fd = fd,
.events = POLLIN|POLLHUP,
};
+ int r;
+
r = poll(&pollfd, 1, 0);
if (r < 0)
return -errno;
}
int fd_wait_for_event(int fd, int event, usec_t t) {
- int r;
+
struct pollfd pollfd = {
.fd = fd,
.events = event,
};
- r = poll(&pollfd, 1, t == (usec_t) -1 ? -1 : (int) (t / USEC_PER_MSEC));
+ struct timespec ts;
+ int r;
+
+ r = ppoll(&pollfd, 1, t == (usec_t) -1 ? NULL : timespec_store(&ts, t), NULL);
if (r < 0)
return -errno;
t[k] = '.';
stpcpy(stpcpy(t+k+1, fn), "XXXXXX");
- fd = mkostemp(t, O_WRONLY|O_CLOEXEC);
+ fd = mkostemp_safe(t, O_WRONLY|O_CLOEXEC);
if (fd < 0) {
free(t);
return -errno;
*ret = s;
return 0;
}
+
+int mkostemp_safe(char *pattern, int flags) {
+ unsigned long tries = TMP_MAX;
+ char *s;
+ int r;
+ _cleanup_umask_ mode_t u;
+
+ assert(pattern);
+
+ u = umask(077);
+
+ /* This is much like like mkostemp() but avoids using any
+ * static variables, thus is async signal safe. Also, it's not
+ * subject to umask(). */
+
+ s = endswith(pattern, "XXXXXX");
+ if (!s)
+ return -EINVAL;
+
+ while (tries--) {
+ unsigned i;
+ int fd;
+
+ r = dev_urandom(s, 6);
+ if (r < 0)
+ return r;
+
+ for (i = 0; i < 6; i++)
+ s[i] = ALPHANUMERICAL[(unsigned) s[i] % (sizeof(ALPHANUMERICAL)-1)];
+
+ fd = open(pattern, flags|O_EXCL|O_CREAT|O_NOCTTY|O_NOFOLLOW, S_IRUSR|S_IWUSR);
+ if (fd >= 0)
+ return fd;
+ if (!IN_SET(errno, EEXIST, EINTR))
+ return -errno;
+ }
+
+ return -EEXIST;
+}
+
+int open_tmpfile(const char *path, int flags) {
+ char *p;
+ int fd;
+
+ assert(path);
+
+#ifdef O_TMPFILE
+ /* Try O_TMPFILE first, if it is supported */
+ fd = open(path, flags|O_TMPFILE, S_IRUSR|S_IWUSR);
+ if (fd >= 0)
+ return fd;
+#endif
+
+ /* Fall back to unguessable name + unlinking */
+ p = strappenda(path, "/systemd-tmp-XXXXXX");
+
+ fd = mkostemp_safe(p, flags);
+ if (fd < 0)
+ return fd;
+
+ unlink(p);
+ return fd;
+}
~ianmdlvl / elogind.git / blobdiff