diff options
Diffstat (limited to 'deps/uv/src/unix/random-devurandom.c')
-rw-r--r-- | deps/uv/src/unix/random-devurandom.c | 93 |
1 files changed, 93 insertions, 0 deletions
diff --git a/deps/uv/src/unix/random-devurandom.c b/deps/uv/src/unix/random-devurandom.c new file mode 100644 index 0000000000..bfc40d20f8 --- /dev/null +++ b/deps/uv/src/unix/random-devurandom.c @@ -0,0 +1,93 @@ +/* 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" + +#include <sys/stat.h> +#include <unistd.h> + +static uv_once_t once = UV_ONCE_INIT; +static int status; + + +int uv__random_readpath(const char* path, void* buf, size_t buflen) { + struct stat s; + size_t pos; + ssize_t n; + int fd; + + fd = uv__open_cloexec(path, O_RDONLY); + + if (fd == -1) + return UV__ERR(errno); + + if (fstat(fd, &s)) { + uv__close(fd); + return UV__ERR(errno); + } + + if (!S_ISCHR(s.st_mode)) { + uv__close(fd); + return UV_EIO; + } + + for (pos = 0; pos != buflen; pos += n) { + do + n = read(fd, (char*) buf + pos, buflen - pos); + while (n == -1 && errno == EINTR); + + if (n == -1) { + uv__close(fd); + return UV__ERR(errno); + } + + if (n == 0) { + uv__close(fd); + return UV_EIO; + } + } + + uv__close(fd); + return 0; +} + + +static void uv__random_devurandom_init(void) { + char c; + + /* Linux's and NetBSD's random(4) man page suggests applications should read + * at least once from /dev/random before switching to /dev/urandom in order + * to seed the system RNG. Reads from /dev/random can of course block + * indefinitely until entropy is available but that's the point. + */ + status = uv__random_readpath("/dev/random", &c, 1); +} + + +int uv__random_devurandom(void* buf, size_t buflen) { + uv_once(&once, uv__random_devurandom_init); + + if (status != 0) + return status; + + return uv__random_readpath("/dev/urandom", buf, buflen); +} |