* ended our handle will be dead. It's important that
* we do this after sleeping, so that we don't enter
* an endless loop. */
- safe_close(fd);
+ fd = safe_close(fd);
}
safe_close(notify);
}
int dev_urandom(void *p, size_t n) {
- _cleanup_close_ int fd;
+ static int have_syscall = -1;
+ int r, fd;
ssize_t k;
+ /* Gathers some randomness from the kernel. This call will
+ * never block, and will always return some data from the
+ * kernel, regardless if the random pool is fully initialized
+ * or not. It thus makes no guarantee for the quality of the
+ * returned entropy, but is good enough for or usual usecases
+ * of seeding the hash functions for hashtable */
+
+ /* Use the getrandom() syscall unless we know we don't have
+ * it, or when the requested size is too large for it. */
+ if (have_syscall != 0 || (size_t) (int) n != n) {
+ r = getrandom(p, n, GRND_NONBLOCK);
+ if (r == (int) n) {
+ have_syscall = true;
+ return 0;
+ }
+
+ if (r < 0) {
+ if (errno == ENOSYS)
+ /* we lack the syscall, continue with
+ * reading from /dev/urandom */
+ have_syscall = false;
+ else if (errno == EAGAIN)
+ /* not enough entropy for now. Let's
+ * remember to use the syscall the
+ * next time, again, but also read
+ * from /dev/urandom for now, which
+ * doesn't care about the current
+ * amount of entropy. */
+ have_syscall = true;
+ else
+ return -errno;
+ } else
+ /* too short read? */
+ return -EIO;
+ }
+
fd = open("/dev/urandom", O_RDONLY|O_CLOEXEC|O_NOCTTY);
if (fd < 0)
return errno == ENOENT ? -ENOSYS : -errno;
k = loop_read(fd, p, n, true);
+ safe_close(fd);
+
if (k < 0)
return (int) k;
if ((size_t) k != n)
return 0;
}
-void random_bytes(void *p, size_t n) {
+void initialize_srand(void) {
static bool srand_called = false;
+ unsigned x;
+#ifdef HAVE_SYS_AUXV_H
+ void *auxv;
+#endif
+
+ if (srand_called)
+ return;
+
+ x = 0;
+
+#ifdef HAVE_SYS_AUXV_H
+ /* The kernel provides us with a bit of entropy in auxv, so
+ * let's try to make use of that to seed the pseudo-random
+ * generator. It's better than nothing... */
+
+ auxv = (void*) getauxval(AT_RANDOM);
+ if (auxv)
+ x ^= *(unsigned*) auxv;
+#endif
+
+ x ^= (unsigned) now(CLOCK_REALTIME);
+ x ^= (unsigned) gettid();
+
+ srand(x);
+ srand_called = true;
+}
+
+void random_bytes(void *p, size_t n) {
uint8_t *q;
int r;
/* 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, so let's try to make use of that to seed the
- * pseudo-random generator. It's better than
- * nothing... */
-
- void *auxv;
-
- auxv = (void*) getauxval(AT_RANDOM);
- if (auxv)
- x ^= *(unsigned*) auxv;
-#endif
-
- x ^= (unsigned) now(CLOCK_REALTIME);
- x ^= (unsigned) gettid();
-
- srand(x);
- srand_called = true;
- }
+ initialize_srand();
for (q = p; q < (uint8_t*) p + n; q ++)
*q = rand();
case CURLY:
if (*e == '{') {
- if (!(k = strnappend(r, word, e-word-1)))
+ k = strnappend(r, word, e-word-1);
+ if (!k)
goto fail;
free(r);
state = VARIABLE;
} else if (*e == '$') {
- if (!(k = strnappend(r, word, e-word)))
+ k = strnappend(r, word, e-word);
+ if (!k)
goto fail;
free(r);
}
}
- if (!(k = strnappend(r, word, e-word)))
+ k = strnappend(r, word, e-word);
+ if (!k)
goto fail;
free(r);
c = 0;
e = getenv("COLUMNS");
if (e)
- safe_atoi(e, &c);
+ (void) safe_atoi(e, &c);
if (c <= 0)
c = fd_columns(STDOUT_FILENO);
l = 0;
e = getenv("LINES");
if (e)
- safe_atou(e, &l);
+ (void) safe_atou(e, &l);
if (l <= 0)
l = fd_lines(STDOUT_FILENO);
if (lstat(path, &info) < 0)
return -errno;
- if (S_ISLNK(info.st_mode))
- return 1;
+ return !!S_ISLNK(info.st_mode);
+}
- return 0;
+int is_dir(const char* path, bool follow) {
+ struct stat st;
+
+ if (follow) {
+ if (stat(path, &st) < 0)
+ return -errno;
+ } else {
+ if (lstat(path, &st) < 0)
+ return -errno;
+ }
+
+ return !!S_ISDIR(st.st_mode);
}
int unquote_first_word(const char **p, char **ret) {
return 0;
}
+
+int sethostname_idempotent(const char *s) {
+ int r;
+ char buf[HOST_NAME_MAX + 1] = {};
+
+ assert(s);
+
+ r = gethostname(buf, sizeof(buf));
+ if (r < 0)
+ return -errno;
+
+ if (streq(buf, s))
+ return 0;
+
+ r = sethostname(s, strlen(s));
+ if (r < 0)
+ return -errno;
+
+ return 1;
+}
~ianmdlvl / elogind.git / blobdiff