diff options
Diffstat (limited to 'Utilities/cmlibuv/src/unix/random-getrandom.c')
-rw-r--r-- | Utilities/cmlibuv/src/unix/random-getrandom.c | 88 |
1 files changed, 88 insertions, 0 deletions
diff --git a/Utilities/cmlibuv/src/unix/random-getrandom.c b/Utilities/cmlibuv/src/unix/random-getrandom.c new file mode 100644 index 0000000..bcc9408 --- /dev/null +++ b/Utilities/cmlibuv/src/unix/random-getrandom.c @@ -0,0 +1,88 @@ +/* Copyright libuv contributors. All rights reserved. + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to + * deal in the Software without restriction, including without limitation the + * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or + * sell copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS + * IN THE SOFTWARE. + */ + +#include "uv.h" +#include "internal.h" + +#ifdef __linux__ + +#include "linux-syscalls.h" + +#define uv__random_getrandom_init() 0 + +#else /* !__linux__ */ + +#include <stddef.h> +#include <dlfcn.h> + +typedef ssize_t (*uv__getrandom_cb)(void *, size_t, unsigned); + +static uv__getrandom_cb uv__getrandom; +static uv_once_t once = UV_ONCE_INIT; + +static void uv__random_getrandom_init_once(void) { + uv__getrandom = (uv__getrandom_cb) dlsym(RTLD_DEFAULT, "getrandom"); +} + +static int uv__random_getrandom_init(void) { + uv_once(&once, uv__random_getrandom_init_once); + + if (uv__getrandom == NULL) + return UV_ENOSYS; + + return 0; +} + +#endif /* !__linux__ */ + +int uv__random_getrandom(void* buf, size_t buflen) { + ssize_t n; + size_t pos; + int rc; + + rc = uv__random_getrandom_init(); + if (rc != 0) + return rc; + + for (pos = 0; pos != buflen; pos += n) { + do { + n = buflen - pos; + + /* Most getrandom() implementations promise that reads <= 256 bytes + * will always succeed and won't be interrupted by signals. + * It's therefore useful to split it up in smaller reads because + * one big read may, in theory, continuously fail with EINTR. + */ + if (n > 256) + n = 256; + + n = uv__getrandom((char *) buf + pos, n, 0); + } while (n == -1 && errno == EINTR); + + if (n == -1) + return UV__ERR(errno); + + if (n == 0) + return UV_EIO; + } + + return 0; +} |