| /* 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 < 0) |
| return fd; |
| |
| 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 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); |
| } |