From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.org/gmane.linux.lib.musl.general/12334 Path: news.gmane.org!.POSTED!not-for-mail From: Hauke Mehrtens Newsgroups: gmane.linux.lib.musl.general Subject: [PATCH v2] Add getrandom syscall wrapper and getentropy function Date: Sat, 6 Jan 2018 23:08:09 +0100 Message-ID: <20180106220809.10078-1-hauke@hauke-m.de> Reply-To: musl@lists.openwall.com NNTP-Posting-Host: blaine.gmane.org X-Trace: blaine.gmane.org 1515276407 25790 195.159.176.226 (6 Jan 2018 22:06:47 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Sat, 6 Jan 2018 22:06:47 +0000 (UTC) Cc: Hauke Mehrtens To: musl@lists.openwall.com Original-X-From: musl-return-12350-gllmg-musl=m.gmane.org@lists.openwall.com Sat Jan 06 23:06:43 2018 Return-path: Envelope-to: gllmg-musl@m.gmane.org Original-Received: from mother.openwall.net ([195.42.179.200]) by blaine.gmane.org with smtp (Exim 4.84_2) (envelope-from ) id 1eXwbu-00065H-7Y for gllmg-musl@m.gmane.org; Sat, 06 Jan 2018 23:06:38 +0100 Original-Received: (qmail 22296 invoked by uid 550); 6 Jan 2018 22:08:37 -0000 Mailing-List: contact musl-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Original-Received: (qmail 22247 invoked from network); 6 Jan 2018 22:08:36 -0000 X-Virus-Scanned: amavisd-new at heinlein-support.de Xref: news.gmane.org gmane.linux.lib.musl.general:12334 Archived-At: This syscall is available since Linux 3.17 and was also implemented in glibc in version 2.25 using the same interfaces. The getrandom function is a pure syscall wrapper liker glibc does it. getentropy is implemented on top of the getrandom syscall and fills the buffer. Currently no fallback is implemented this could be possible by using AT_RANDOM in the future. --- include/sys/random.h | 21 +++++++++++++++++++++ src/linux/getentropy.c | 29 +++++++++++++++++++++++++++++ src/linux/getrandom.c | 7 +++++++ 3 files changed, 57 insertions(+) create mode 100644 include/sys/random.h create mode 100644 src/linux/getentropy.c create mode 100644 src/linux/getrandom.c diff --git a/include/sys/random.h b/include/sys/random.h new file mode 100644 index 00000000..5b09e394 --- /dev/null +++ b/include/sys/random.h @@ -0,0 +1,21 @@ +#ifndef _SYS_RANDOM_H +#define _SYS_RANDOM_H +#ifdef __cplusplus +extern "C" { +#endif + +#define __NEED_size_t +#define __NEED_ssize_t +#include + +#define GRND_NONBLOCK 0x0001 +#define GRND_RANDOM 0x0002 + +ssize_t getrandom(void *buf, size_t buflen, unsigned int flags); + +int getentropy(void *buffer, size_t length); + +#ifdef __cplusplus +} +#endif +#endif diff --git a/src/linux/getentropy.c b/src/linux/getentropy.c new file mode 100644 index 00000000..48ca3d51 --- /dev/null +++ b/src/linux/getentropy.c @@ -0,0 +1,29 @@ +#include +#include +#include "syscall.h" + +int getentropy(void *buffer, size_t length) +{ + int ret; + char *pos = buffer; + size_t rem = length; + + if (length > 256) { + return __syscall_ret(-EIO); + } + + while (rem) { + ret = __syscall_cp(SYS_getrandom, pos, rem, 0); + if (ret == -EINTR) { + continue; + } else if (ret == -EFAULT || ret == -ENOSYS) { + return __syscall_ret(ret); + } else if (ret <= 0) { + return __syscall_ret(-EIO); + } + + pos += ret; + rem -= ret; + } + return 0; +} diff --git a/src/linux/getrandom.c b/src/linux/getrandom.c new file mode 100644 index 00000000..795b932c --- /dev/null +++ b/src/linux/getrandom.c @@ -0,0 +1,7 @@ +#include +#include "syscall.h" + +ssize_t getrandom(void *buf, size_t buflen, unsigned int flags) +{ + return syscall_cp(SYS_getrandom, buf, buflen, flags); +} -- 2.11.0