getentropy(2) is in POSIX-2024, so adjust the #include visibility,

change the "too much" error to EINVAL, add GETENTROPY_MAX to
<limits.h> (via sys/syslimits.h), and update the manpage.

ok deraadt@

diff --git a/include/unistd.h b/include/unistd.h
index 1fda33a..0497207 100644 (file)
--- a/include/unistd.h
+++ b/include/unistd.h
@@ -1,4 +1,4 @@
-/*     $OpenBSD: unistd.h,v 1.109 2024/05/18 05:20:22 guenther Exp $ */
+/*     $OpenBSD: unistd.h,v 1.110 2024/08/02 01:53:21 guenther Exp $ */
 /*     $NetBSD: unistd.h,v 1.26.4.1 1996/05/28 02:31:51 mrg Exp $      */
 
 /*-
@@ -471,6 +471,10 @@ int        symlinkat(const char *, int, const char *);
 int    unlinkat(int, const char *, int);
 #endif
 
+#if __POSIX_VISIBLE >= 202405 || __BSD_VISIBLE
+int    getentropy(void *, size_t);
+#endif
+
 #if __BSD_VISIBLE
 int    dup3(int, int, int);
 int    pipe2(int [2], int);
@@ -525,7 +529,6 @@ int  setthrname(pid_t, const char *);
 void    setusershell(void);
 int     strtofflags(char **, u_int32_t *, u_int32_t *);
 int     swapctl(int cmd, const void *arg, int misc);
-int     getentropy(void *, size_t);
 int     pledge(const char *, const char *);
 int     unveil(const char *, const char *);
 pid_t   __tfork_thread(const struct __tfork *, size_t, void (*)(void *),

diff --git a/lib/libc/sys/getentropy.2 b/lib/libc/sys/getentropy.2
index 3f4fb05..5432069 100644 (file)
--- a/lib/libc/sys/getentropy.2
+++ b/lib/libc/sys/getentropy.2
@@ -1,4 +1,4 @@
-.\"    $OpenBSD: getentropy.2,v 1.10 2022/02/06 00:29:02 jsg Exp $
+.\"    $OpenBSD: getentropy.2,v 1.11 2024/08/02 01:53:21 guenther Exp $
 .\"
 .\" Copyright (c) 2014 Theo de Raadt
 .\"
@@ -14,7 +14,7 @@
 .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\"
-.Dd $Mdocdate: February 6 2022 $
+.Dd $Mdocdate: August 2 2024 $
 .Dt GETENTROPY 2
 .Os
 .Sh NAME
@@ -30,7 +30,9 @@ fills a buffer with high-quality entropy, which can be used
 as input for process-context pseudorandom generators like
 .Xr arc4random 3 .
 .Pp
-The maximum buffer size permitted is 256 bytes.
+The maximum buffer size permitted is
+.Dv GETENTROPY_MAX
+(256) bytes.
 .Pp
 .Fn getentropy
 is not intended for regular code; use the
@@ -51,11 +53,16 @@ The
 .Fa buf
 parameter points to an
 invalid address.
-.It Bq Er EIO
-Too many bytes requested, or some other fatal error occurred.
+.It Bq Er EINVAL
+Too many bytes requested.
 .El
 .Sh SEE ALSO
 .Xr arc4random 3
+.Sh STANDARDS
+The
+.Fn getentropy
+function conforms to
+.St -p1003.1-2024 .
 .Sh HISTORY
 The
 .Fn getentropy

diff --git a/sys/dev/rnd.c b/sys/dev/rnd.c
index 4ad4a73..259721d 100644 (file)
--- a/sys/dev/rnd.c
+++ b/sys/dev/rnd.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: rnd.c,v 1.228 2024/06/14 10:17:05 claudio Exp $       */
+/*     $OpenBSD: rnd.c,v 1.229 2024/08/02 01:53:21 guenther Exp $      */
 
 /*
  * Copyright (c) 2011,2020 Theo de Raadt.
@@ -75,6 +75,7 @@
 #include <sys/msgbuf.h>
 #include <sys/mount.h>
 #include <sys/syscallargs.h>
+#include <sys/syslimits.h>
 
 #include <crypto/sha2.h>
 
@@ -814,11 +815,11 @@ sys_getentropy(struct proc *p, void *v, register_t *retval)
                syscallarg(void *) buf;
                syscallarg(size_t) nbyte;
        } */ *uap = v;
-       char buf[256];
+       char buf[GETENTROPY_MAX];
        int error;
 
        if (SCARG(uap, nbyte) > sizeof(buf))
-               return (EIO);
+               return (EINVAL);
        arc4random_buf(buf, SCARG(uap, nbyte));
        if ((error = copyout(buf, SCARG(uap, buf), SCARG(uap, nbyte))) != 0)
                return (error);

diff --git a/sys/sys/syslimits.h b/sys/sys/syslimits.h
index 4ebc656..d8c98a9 100644 (file)
--- a/sys/sys/syslimits.h
+++ b/sys/sys/syslimits.h
@@ -1,4 +1,4 @@
-/*     $OpenBSD: syslimits.h,v 1.15 2022/02/22 16:58:08 deraadt Exp $  */
+/*     $OpenBSD: syslimits.h,v 1.16 2024/08/02 01:53:21 guenther Exp $ */
 /*     $NetBSD: syslimits.h,v 1.12 1995/10/05 05:26:19 thorpej Exp $   */
 
 /*
@@ -76,4 +76,8 @@
 #define HOST_NAME_MAX          255     /* max hostname length w/o NUL */
 #endif
 
+#if __POSIX_VISIBLE >= 202405
+#define        GETENTROPY_MAX            256   /* max bytes from getentropy(2) */
+#endif
+
 #define _MAXCOMLEN             24      /* includes NUL */