| Message ID | 20230709100653.17091-1-anton@khirnov.net |
|---|---|
| State | New |
| Headers | show |
| Series | [FFmpeg-devel] lavu/random_seed: use getrandom() when available | expand |
| Context | Check | Description |
|---|---|---|
| yinshiyou/make_loongarch64 | success | Make finished |
| yinshiyou/make_fate_loongarch64 | success | Make fate finished |
| andriy/make_x86 | success | Make finished |
| andriy/make_fate_x86 | success | Make fate finished |
On 7/9/2023 7:06 AM, Anton Khirnov wrote: > It is a better interface for /dev/u?random on Linux, which avoids the > issues associated with opening files. > --- > configure | 2 ++ > libavutil/random_seed.c | 16 ++++++++++++++++ > 2 files changed, 18 insertions(+) > > diff --git a/configure b/configure > index 0ab0761011..f8c809e491 100755 > --- a/configure > +++ b/configure > @@ -2310,6 +2310,7 @@ SYSTEM_FUNCS=" > getauxval > getenv > gethrtime > + getrandom > getopt > GetModuleHandle > GetProcessAffinityMask > @@ -6387,6 +6388,7 @@ check_func fcntl > check_func fork > check_func gethrtime > check_func getopt > +check_func_headers "sys/random.h" getrandom > check_func getrusage > check_func gettimeofday > check_func isatty > diff --git a/libavutil/random_seed.c b/libavutil/random_seed.c > index f167b172f2..92bf9ef8e1 100644 > --- a/libavutil/random_seed.c > +++ b/libavutil/random_seed.c > @@ -35,6 +35,9 @@ > #elif CONFIG_OPENSSL > #include <openssl/rand.h> > #endif > +#if HAVE_GETRANDOM > +#include <sys/random.h> > +#endif > #include <fcntl.h> > #include <math.h> > #include <time.h> > @@ -51,6 +54,7 @@ > #define TEST 0 > #endif > > +#if !HAVE_GETRANDOM > static int read_random(uint8_t *dst, size_t len, const char *file) > { > #if HAVE_UNISTD_H > @@ -70,6 +74,7 @@ static int read_random(uint8_t *dst, size_t len, const char *file) > return AVERROR(ENOSYS); > #endif > } > +#endif > > static uint32_t get_generic_seed(void) > { > @@ -147,7 +152,18 @@ int av_random_bytes(uint8_t* buf, size_t len) > return 0; > #endif > > + // getrandom() is a better interface for /dev/(u)random on Linux, > + // so it makes no sense to try both > +#if HAVE_GETRANDOM > + { > + ssize_t read = getrandom(buf, len, GRND_NONBLOCK); > + if (read < 0) > + return errno == EAGAIN ? AVERROR_EXTERNAL : AVERROR(errno); > + return read != len ? AVERROR_UNKNOWN : 0; This is returning no matter what the result, when it should only return on success (the !err check below), or fallback to the other implementations otherwise. > + } > +#else > err = read_random(buf, len, "/dev/urandom"); > +#endif > if (!err) > return err; >
diff --git a/configure b/configure index 0ab0761011..f8c809e491 100755 --- a/configure +++ b/configure @@ -2310,6 +2310,7 @@ SYSTEM_FUNCS=" getauxval getenv gethrtime + getrandom getopt GetModuleHandle GetProcessAffinityMask @@ -6387,6 +6388,7 @@ check_func fcntl check_func fork check_func gethrtime check_func getopt +check_func_headers "sys/random.h" getrandom check_func getrusage check_func gettimeofday check_func isatty diff --git a/libavutil/random_seed.c b/libavutil/random_seed.c index f167b172f2..92bf9ef8e1 100644 --- a/libavutil/random_seed.c +++ b/libavutil/random_seed.c @@ -35,6 +35,9 @@ #elif CONFIG_OPENSSL #include <openssl/rand.h> #endif +#if HAVE_GETRANDOM +#include <sys/random.h> +#endif #include <fcntl.h> #include <math.h> #include <time.h> @@ -51,6 +54,7 @@ #define TEST 0 #endif +#if !HAVE_GETRANDOM static int read_random(uint8_t *dst, size_t len, const char *file) { #if HAVE_UNISTD_H @@ -70,6 +74,7 @@ static int read_random(uint8_t *dst, size_t len, const char *file) return AVERROR(ENOSYS); #endif } +#endif static uint32_t get_generic_seed(void) { @@ -147,7 +152,18 @@ int av_random_bytes(uint8_t* buf, size_t len) return 0; #endif + // getrandom() is a better interface for /dev/(u)random on Linux, + // so it makes no sense to try both +#if HAVE_GETRANDOM + { + ssize_t read = getrandom(buf, len, GRND_NONBLOCK); + if (read < 0) + return errno == EAGAIN ? AVERROR_EXTERNAL : AVERROR(errno); + return read != len ? AVERROR_UNKNOWN : 0; + } +#else err = read_random(buf, len, "/dev/urandom"); +#endif if (!err) return err;