Clarify what happens to the proc structure used by apr_fork().

Set the proc->pid field to the pid of the newly created child.
Note that a mere pid value provides little entropy to mix into
the child random pool.


git-svn-id: http://svn.apache.org/repos/asf/apr/apr/trunk@1198860 13f79535-47bb-0310-9956-ffa450edef68

2 files changed, 8 insertions, 7 deletions

diff --git a/random/unix/apr_random.c b/random/unix/apr_random.c
index c6d671c6b..852cfd6e3 100644
--- a/random/unix/apr_random.c
+++ b/random/unix/apr_random.c
@@ -159,6 +159,11 @@ APR_DECLARE(void) apr_random_after_fork(apr_proc_t *proc)
     apr_random_t *r;
 
     for (r = all_random; r; r = r->next)
+        /* 
+         * XXX Note: the pid does not provide sufficient entropy to 
+         * actually call this secure.  See Ben's paper referenced at 
+         * the top of this file. 
+         */
         mixer(r,proc->pid);
 }
 
diff --git a/threadproc/unix/proc.c b/threadproc/unix/proc.c
index 8ded39177..004772ff8 100644
--- a/threadproc/unix/proc.c
+++ b/threadproc/unix/proc.c
@@ -219,15 +219,14 @@ APR_DECLARE(apr_status_t) apr_procattr_detach_set(apr_procattr_t *attr,
 APR_DECLARE(apr_status_t) apr_proc_fork(apr_proc_t *proc, apr_pool_t *pool)
 {
     int pid;
+    
+    memset(proc, 0, sizeof(apr_proc_t));
 
     if ((pid = fork()) < 0) {
         return errno;
     }
     else if (pid == 0) {
-        proc->pid = pid;
-        proc->in = NULL;
-        proc->out = NULL;
-        proc->err = NULL;
+        proc->pid = getpid();
 
         apr_random_after_fork(proc);
 
@@ -235,9 +234,6 @@ APR_DECLARE(apr_status_t) apr_proc_fork(apr_proc_t *proc, apr_pool_t *pool)
     }
 
     proc->pid = pid;
-    proc->in = NULL;
-    proc->out = NULL;
-    proc->err = NULL;
 
     return APR_INPARENT;
 }