Seperate arc4random's os-dependent parts into static inline functions,

making it much easier for libressl -portable to fill in the gaps.
ok bcook beck

1 files changed, 11 insertions, 36 deletions

diff --git a/src/lib/libc/crypt/arc4random.c b/src/lib/libc/crypt/arc4random.c
index 565bfa0333..d42022c455 100644
--- a/src/lib/libc/crypt/arc4random.c
+++ b/src/lib/libc/crypt/arc4random.c
@@ -1,4 +1,4 @@
-/*      $OpenBSD: arc4random.c,v 1.46 2014/07/17 14:30:41 deraadt Exp $ */
+/*      $OpenBSD: arc4random.c,v 1.47 2014/07/18 02:05:55 deraadt Exp $ */
 
 /*
  * Copyright (c) 1996, David Mazieres <dm@uun.org>
@@ -52,11 +52,16 @@
 #define RSBUFSZ (16*BLOCKSZ)
 
 /* Marked MAP_INHERIT_ZERO, so zero'd out in fork children. */
-static struct {
+static struct _rs {
         size_t          rs_have;        /* valid bytes at end of rs_buf */
         size_t          rs_count;       /* bytes till reseed */
 } *rs;
 
+static inline void *_rs_allocate(size_t len);
+static inline void _rs_forkdetect(void);
+static inline void _rs_forkdetectsetup(struct _rs *buf, size_t len);
+#include "arc4random.h"
+
 /* Preserved in fork children. */
 static struct {
         chacha_ctx      rs_chacha;      /* chacha context for random keystream */
@@ -65,19 +70,6 @@ static struct {
 
 static inline void _rs_rekey(u_char *dat, size_t datlen);
 
-#ifndef MAP_INHERIT_ZERO
-static inline void
-_rs_forkhandler(void)
-{
-        /*
-         * Race-free because we're running single-threaded in a new
-         * address space, and once allocated rs is never deallocated.
-         */
-        if (rs)
-                rs->rs_count = 0;
-}
-#endif /* MAP_INHERIT_ZERO */
-
 static inline void
 _rs_init(u_char *buf, size_t n)
 {
@@ -85,19 +77,12 @@ _rs_init(u_char *buf, size_t n)
                 return;
 
         if (rs == NULL) {
-                if ((rs = mmap(NULL, sizeof(*rs), PROT_READ|PROT_WRITE,
-                    MAP_ANON|MAP_PRIVATE, -1, 0)) == MAP_FAILED)
-                        abort();
-#ifdef MAP_INHERIT_ZERO
-                if (minherit(rs, sizeof(*rs), MAP_INHERIT_ZERO) == -1)
+                if ((rs = _rs_allocate(sizeof(*rs))) == NULL)
                         abort();
-#else
-                _ARC4_ATFORK(_rs_forkhandler);
-#endif
+                _rs_forkdetectsetup(rs, sizeof(*rs));
         }
         if (rsx == NULL) {
-                if ((rsx = mmap(NULL, sizeof(*rsx), PROT_READ|PROT_WRITE,
-                    MAP_ANON|MAP_PRIVATE, -1, 0)) == MAP_FAILED)
+                if ((rsx = _rs_allocate(sizeof(*rsx))) == NULL)
                         abort();
         }
 
@@ -129,17 +114,7 @@ _rs_stir(void)
 static inline void
 _rs_stir_if_needed(size_t len)
 {
-#ifndef MAP_INHERIT_ZERO
-        static pid_t _rs_pid = 0;
-        pid_t pid = getpid();
-
-        /* If a system lacks MAP_INHERIT_ZERO, resort to getpid() */
-        if (_rs_pid == 0 || _rs_pid != pid) {
-                _rs_pid = pid;
-                if (rs)
-                        rs->rs_count = 0;
-        }
-#endif
+        _rs_forkdetect();
         if (!rs || rs->rs_count <= len)
                 _rs_stir();
         if (rs->rs_count <= len)