diff options
| -rw-r--r-- | libavutil/random_seed.c | 34 |
1 files changed, 24 insertions, 10 deletions
diff --git a/libavutil/random_seed.c b/libavutil/random_seed.c index 00d6317241..a2b388549c 100644 --- a/libavutil/random_seed.c +++ b/libavutil/random_seed.c @@ -24,19 +24,33 @@ #include "random_seed.h" #include "avutil.h" +static int read_random(uint32_t *dst, const char *file) +{ + int fd = open(file, O_RDONLY); + int err = -1; + + if (fd == -1) + return -1; +#if HAVE_FCNTL && defined(O_NONBLOCK) + if (fcntl(fd, F_SETFL, fcntl(fd, F_GETFL) | O_NONBLOCK) != -1) +#endif + err = read(fd, dst, sizeof(*dst)); + close(fd); + + return err; +} + uint32_t av_get_random_seed(void) { uint32_t seed; - int fd; - - if ((fd = open("/dev/random", O_RDONLY)) == -1) - fd = open("/dev/urandom", O_RDONLY); - if (fd != -1){ - int err = read(fd, &seed, 4); - close(fd); - if (err == 4) - return seed; - } + int err; + + err = read_random(&seed, "/dev/urandom"); + if (err != sizeof(seed)) + err = read_random(&seed, "/dev/random"); + if (err == sizeof(seed)) + return seed; + #ifdef AV_READ_TIME seed = AV_READ_TIME(); #endif |