Add type field to UDP datagrams

This will allow future extensions

diff --git a/net/can/canethgw.c b/net/can/canethgw.c
index 6dda6f36dcdda7e0fbc53cf68870c9eb0a883b05..635383de66e85b201fca35fbecb627589959601c 100644 (file)
--- a/net/can/canethgw.c
+++ b/net/can/canethgw.c
@@ -24,6 +24,10 @@
 
 MODULE_LICENSE("GPL");
 
+enum msg_types {
+       CAN_FRAME,
+};
+
 struct cegw_job
 {
        struct kref refcount;
@@ -45,8 +49,9 @@ static void cegw_job_release(struct kref *ref);
 static int cegw_udp_send(struct socket *udp_sock, struct can_frame *cf, struct sockaddr_in* addr)
 {
        struct msghdr mh;
-       struct kvec vec;
+       struct kvec vec[2];
        int err;
+       __u16 type = CAN_FRAME;
 
        mh.msg_name = addr;
        mh.msg_namelen = sizeof(*addr);
@@ -54,10 +59,12 @@ static int cegw_udp_send(struct socket *udp_sock, struct can_frame *cf, struct s
        mh.msg_controllen = 0;
        mh.msg_flags = 0;
 
-       vec.iov_base = cf;
-       vec.iov_len = sizeof(*cf);
+       type = cpu_to_be16(type);
+       vec[0].iov_base = &type;
+       vec[1].iov_base = cf;
+       vec[1].iov_len = sizeof(*cf);
 
-       err = kernel_sendmsg(udp_sock, &mh, &vec, 1, sizeof(*cf));
+       err = kernel_sendmsg(udp_sock, &mh, vec, 2, sizeof(*cf));
 
        return err;
 }
@@ -90,26 +97,34 @@ static int cegw_can_send(struct socket* can_sock, struct can_frame* cf)
 static int cegw_udp2can(void *data)
 {
        struct can_frame cf;
-       struct kvec vec;
+       struct kvec vec[2];
        struct msghdr mh;
        struct cegw_job *job = (struct cegw_job *)data;
        struct socket *udp_sock = NULL, *can_sock = NULL;
        int ret = 0;
+       __u16 type;
 
        memset(&mh, 0, sizeof(mh));
        udp_sock = job->udp_sock;
        can_sock = job->can_sock;
 
        while (1) {
-               vec.iov_base = &cf;
-               vec.iov_len = sizeof(cf);
-               ret = kernel_recvmsg(udp_sock, &mh, &vec, 1,
+               vec[0].iov_base = &type;
+               vec[0].iov_len = sizeof(type);
+               vec[1].iov_base = &cf;
+               vec[1].iov_len = sizeof(cf);
+               ret = kernel_recvmsg(udp_sock, &mh, vec, 2,
                                     sizeof(cf), 0);
-               if (ret < 1)
+               if (ret != sizeof(type) + sizeof(cf))
                        break;
 
-               cf.can_id = be32_to_cpu(cf.can_id);
-               cegw_can_send(can_sock, &cf);
+               type = be16_to_cpu(type);
+               switch (type) {
+               case CAN_FRAME:
+                       cf.can_id = be32_to_cpu(cf.can_id);
+                       cegw_can_send(can_sock, &cf);
+               default:;
+               }
        }
 
        cegw_thread_stop(job);