* modules/generators/mod_cgid.c (sock_readhdr): Only set up control

  message block when required; add some additional error handling.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1867878 13f79535-47bb-0310-9956-ffa450edef68

1 files changed, 15 insertions, 7 deletions

diff --git a/modules/generators/mod_cgid.c b/modules/generators/mod_cgid.c
index 67f458a27e..4354499b4f 100644
--- a/modules/generators/mod_cgid.c
+++ b/modules/generators/mod_cgid.c
@@ -381,11 +381,12 @@ static apr_status_t sock_readhdr(int fd, int *errfd, void *vbuf, size_t buf_size
     
     msg.msg_iov = &vec;
     msg.msg_iovlen = 1;
-    
-    msg.msg_control = u.buf;
-    msg.msg_controllen = sizeof(u.buf);
 
-    if (errfd) *errfd = 0;
+    if (errfd) {
+        msg.msg_control = u.buf;
+        msg.msg_controllen = sizeof(u.buf);
+        *errfd = 0;
+    }
     
     /* use MSG_WAITALL to skip loop on truncated reads */
     do {
@@ -395,10 +396,17 @@ static apr_status_t sock_readhdr(int fd, int *errfd, void *vbuf, size_t buf_size
     if (rc == 0) {
         return ECONNRESET;
     }
-    
-    cmsg = CMSG_FIRSTHDR(&msg);
+    else if (rc < 0) {
+        return errno;
+    }
+    else if (rc != buf_size) {
+        /* MSG_WAITALL should ensure the recvmsg blocks until the
+         * entire length is read, but let's be paranoid. */
+        return APR_INCOMPLETE;
+    }
+
     if (errfd
-        && cmsg
+        && (cmsg = CMSG_FIRSTHDR(&msg)) != NULL
         && cmsg->cmsg_len == CMSG_LEN(sizeof(*errfd))
         && cmsg->cmsg_level == SOL_SOCKET
         && cmsg->cmsg_type == SCM_RIGHTS) {