From: Shawn Landden <shawn@churchofgit.com>
Date: Wed, 11 Mar 2015 04:01:47 +0000 (-0700)
Subject: udev-ctrl: fix strict aliasing issues
X-Git-Tag: v219.0~310
X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=commitdiff_plain;h=6421348d5263ee1a36037c3e119a01351f0f83e9;p=elogind.git

udev-ctrl: fix strict aliasing issues

it is ironic that
"The only purpose of this structure is to cast the structure pointer
passed in addr in order to avoid compiler warnings.  See EXAMPLE below."
from bind(2)
---

diff --git a/src/udev/udev-ctrl.c b/src/udev/udev-ctrl.c
index c0c5981db..61d3c5b55 100644
--- a/src/udev/udev-ctrl.c
+++ b/src/udev/udev-ctrl.c
@@ -18,6 +18,7 @@
 #include <sys/socket.h>
 #include <sys/un.h>
 
+#include "socket-util.h"
 #include "udev.h"
 
 /* wire protocol magic must match */
@@ -55,7 +56,7 @@ struct udev_ctrl {
         int refcount;
         struct udev *udev;
         int sock;
-        struct sockaddr_un saddr;
+        union sockaddr_union saddr;
         socklen_t addrlen;
         bool bound;
         bool cleanup_socket;
@@ -94,9 +95,9 @@ struct udev_ctrl *udev_ctrl_new_from_fd(struct udev *udev, int fd) {
         if (r < 0)
                 log_warning_errno(errno, "could not set SO_PASSCRED: %m");
 
-        uctrl->saddr.sun_family = AF_LOCAL;
-        strscpy(uctrl->saddr.sun_path, sizeof(uctrl->saddr.sun_path), "/run/udev/control");
-        uctrl->addrlen = offsetof(struct sockaddr_un, sun_path) + strlen(uctrl->saddr.sun_path);
+        uctrl->saddr.un.sun_family = AF_LOCAL;
+        strscpy(uctrl->saddr.un.sun_path, sizeof(uctrl->saddr.un.sun_path), "/run/udev/control");
+        uctrl->addrlen = offsetof(struct sockaddr_un, sun_path) + strlen(uctrl->saddr.un.sun_path);
         return uctrl;
 }
 
@@ -108,10 +109,10 @@ int udev_ctrl_enable_receiving(struct udev_ctrl *uctrl) {
         int err;
 
         if (!uctrl->bound) {
-                err = bind(uctrl->sock, (struct sockaddr *)&uctrl->saddr, uctrl->addrlen);
+                err = bind(uctrl->sock, &uctrl->saddr.sa, uctrl->addrlen);
                 if (err < 0 && errno == EADDRINUSE) {
-                        unlink(uctrl->saddr.sun_path);
-                        err = bind(uctrl->sock, (struct sockaddr *)&uctrl->saddr, uctrl->addrlen);
+                        unlink(uctrl->saddr.un.sun_path);
+                        err = bind(uctrl->sock, &uctrl->saddr.sa, uctrl->addrlen);
                 }
 
                 if (err < 0) {
@@ -160,7 +161,7 @@ int udev_ctrl_cleanup(struct udev_ctrl *uctrl) {
         if (uctrl == NULL)
                 return 0;
         if (uctrl->cleanup_socket)
-                unlink(uctrl->saddr.sun_path);
+                unlink(uctrl->saddr.un.sun_path);
         return 0;
 }
 
@@ -249,7 +250,7 @@ static int ctrl_send(struct udev_ctrl *uctrl, enum udev_ctrl_msg_type type, int
                 ctrl_msg_wire.intval = intval;
 
         if (!uctrl->connected) {
-                if (connect(uctrl->sock, (struct sockaddr *)&uctrl->saddr, uctrl->addrlen) < 0) {
+                if (connect(uctrl->sock, &uctrl->saddr.sa, uctrl->addrlen) < 0) {
                         err = -errno;
                         goto out;
                 }