Add can-eth-gw from Matejka's repo

diff --git a/include/linux/can/canethgw.h b/include/linux/can/canethgw.h
new file mode 100644 (file)
index 0000000..65d9cc5
--- /dev/null
+++ b/include/linux/can/canethgw.h
@@ -0,0 +1,30 @@
+#ifndef CANETHGW_H
+#define CANETHGW_H
+
+#include <linux/types.h>
+
+struct cegw_ioctl
+{
+       __u32 can_sock;
+       __u32 udp_sock;
+       __u32 udp_dstcnt;
+       __u32 udp_addrlen;
+       struct sockaddr_in udp_dst[0];
+};
+
+#ifdef __KERNEL__
+struct cegw_job
+{
+       struct kref refcount;
+       struct socket* can_sock;
+       struct socket* udp_sock;
+       __u32  udp_dstcnt;
+       struct sockaddr_in udp_dst[0];
+};
+#endif
+
+#define CEGW_IOCTL_BASE 'c'
+#define CEGW_IOCTL_START _IOW(CEGW_IOCTL_BASE, 0, struct cegw_ioctl)
+
+#endif /* CANETHGW_H */
+

diff --git a/net/can/canethgw.c b/net/can/canethgw.c
new file mode 100644 (file)
index 0000000..d5b0302
--- /dev/null
+++ b/net/can/canethgw.c
@@ -0,0 +1,347 @@
+/*
+ * Copyright: (c) 2012 Czech Technical University in Prague
+ *
+ * Authors:
+ *     Radek Matějka <radek.matejka@gmail.com>
+ *     Michal Sojka  <sojkam1@fel.cvut.cz>
+ *
+ * Funded by: Volkswagen Group Research
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/kthread.h>
+#include <linux/file.h>
+#include <net/sock.h>
+#include <linux/can.h>
+#include <linux/miscdevice.h>
+#include "canethgw.h"
+
+MODULE_LICENSE("GPL");
+
+static int cegw_udp2can(void *data);
+static int cegw_udp_send(struct socket *udp_sock, struct can_frame *cf,
+               struct sockaddr_in* addr);
+static int cegw_can2udp(void *data);
+static int cegw_can_send(struct socket *can_sock, struct can_frame *cf);
+static int cegw_thread_start(void *data);
+static int cegw_thread_stop(struct cegw_job *job);
+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;
+       int err;
+
+       mh.msg_name = addr;
+       mh.msg_namelen = sizeof(*addr);
+       mh.msg_control = NULL;
+       mh.msg_controllen = 0;
+       mh.msg_flags = 0;
+
+       vec.iov_base = cf;
+       vec.iov_len = sizeof(*cf);
+
+       err = kernel_sendmsg(udp_sock, &mh, &vec, 1, sizeof(*cf));
+
+       return err;
+}
+
+static int cegw_can_send(struct socket* can_sock, struct can_frame* cf)
+{
+       struct msghdr mh;
+       struct kvec vec;
+       int err;
+
+       mh.msg_name = NULL;
+       mh.msg_namelen = 0;
+       mh.msg_control = NULL;
+       mh.msg_controllen = 0;
+       mh.msg_flags = 0;
+
+       vec.iov_base = cf;
+       vec.iov_len = sizeof(*cf);
+
+       err = kernel_sendmsg(can_sock, &mh, &vec, 1, sizeof(*cf));
+
+       return err;
+}
+
+/**
+ * cegw_udp2can - performs udp->can routing
+ *
+ * This function is run as a thread.
+ */
+static int cegw_udp2can(void *data)
+{
+       struct can_frame cf;
+       struct kvec vec;
+       struct msghdr mh;
+       struct cegw_job *job = (struct cegw_job *)data;
+       struct socket *udp_sock = NULL, *can_sock = NULL;
+       int ret = 0;
+
+       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,
+                               sizeof(cf), 0);
+               if (ret < 1)
+                       break;
+
+               cf.can_id = be32_to_cpu(cf.can_id);
+               cegw_can_send(can_sock, &cf);
+       }
+
+       cegw_thread_stop(job);
+       kref_put(&job->refcount, cegw_job_release);
+       do_exit(ret);
+}
+
+/**
+ * cegw_can2udp - performs can->udp routing
+ *
+ * This function is run as a thread.
+ */
+static int cegw_can2udp(void* data)
+{
+       struct msghdr mh;
+       struct kvec vec;
+       struct can_frame cf;
+       struct cegw_job* job = (struct cegw_job*)data;
+       struct socket* udp_sock = job->udp_sock;
+       struct socket* can_sock = job->can_sock;
+       int i;
+       int ret;
+
+       memset(&mh, 0, sizeof(mh));
+
+       while (1) {
+               vec.iov_base = &cf;
+               vec.iov_len = sizeof(cf);
+
+               ret = kernel_recvmsg(can_sock, &mh, &vec, 1,
+                                          sizeof(cf), 0);
+               if (ret < 1)
+                       break;
+
+               cf.can_id = cpu_to_be32(cf.can_id);
+               for (i=0; i<job->udp_dstcnt; i++) {
+                       cegw_udp_send(udp_sock, &cf, &job->udp_dst[i]);
+               }
+       }
+
+       cegw_thread_stop(job);
+       kref_put(&job->refcount, cegw_job_release);
+       do_exit(ret);
+}
+
+static void cegw_job_release(struct kref *ref)
+{
+       struct cegw_job *job = container_of(ref, struct cegw_job, refcount);
+
+       fput(job->can_sock->file);
+       fput(job->udp_sock->file);
+       kfree(job);
+}
+
+/**
+ * cegw_thread_start - start working threads
+ * @data: (struct cegw_job *) with sockets and udp addresses filled in
+ *
+ * Two threads are started. One is serving udp->can routing and the other
+ * can->udp.
+ */
+static int cegw_thread_start(void *data)
+{
+       struct task_struct *task = NULL;
+       struct cegw_job *job = (struct cegw_job *)data;
+
+       kref_init(&job->refcount);
+       kref_get(&job->refcount);
+
+       task = kthread_run(cegw_udp2can, data, "canethgw_udp2can");
+       if (IS_ERR(task)) {
+               kref_sub(&job->refcount, 2, cegw_job_release);
+               return -ENOMEM;
+       }
+
+       task = kthread_run(cegw_can2udp, data, "canethgw_can2udp");
+       if (IS_ERR(task)) {
+               cegw_thread_stop(job);
+               kref_put(&job->refcount, cegw_job_release);
+               return -ENOMEM;
+       }
+
+       return 0;
+}
+
+/**
+ * cegw_thread_stop - stops threads
+ */
+static int cegw_thread_stop(struct cegw_job *job)
+{
+       int how = SHUT_RDWR;
+       struct sock *sk = NULL;
+       struct socket *udp_sock = job->udp_sock;
+       struct socket *can_sock = job->can_sock;
+
+       kernel_sock_shutdown(udp_sock, SHUT_RDWR);
+
+       /* PF_CAN sockets do not implement shutdown - do it manualy */
+       sk = can_sock->sk;
+       how++;
+       lock_sock(sk);
+       sk->sk_shutdown |= how;
+       sk->sk_state_change(sk);
+       release_sock(sk);
+
+       return 0;
+}
+
+static int cegw_open(struct inode *inode, struct file *file)
+{
+       file->private_data = NULL;
+
+       if (try_module_get(THIS_MODULE) == false)
+               return -EAGAIN;
+
+       return 0;
+}
+
+static int cegw_release(struct inode *inode, struct file *file)
+{
+       struct cegw_job *job = (struct cegw_job *)file->private_data;
+
+       if (job) {
+               cegw_thread_stop(job);
+       }
+
+       module_put(THIS_MODULE);
+       return 0;
+}
+
+/**
+ * cegw_ioctl_start - processes ioctl CEGW_IOCTL_START call
+ *
+ * The function takes over cegw_ioctl structure from userspace and
+ * prepares cegw_job structure. The cegw_job is stored in
+ * file->private_data and used by kernel threads to serve gateway
+ * functionality.
+ */
+static long cegw_ioctl_start(struct file *file, unsigned long arg)
+{
+       int i;
+       int err = 0;
+       __u32 dstcnt = 0;
+       __u32 addrlen = 0;
+       struct cegw_ioctl gwctl;
+       struct cegw_job *job = NULL;
+
+       err = copy_from_user(&gwctl, (void __user *)arg, sizeof(gwctl));
+       if (err != 0)
+               return -EFAULT;
+
+       dstcnt = gwctl.udp_dstcnt;
+       addrlen = gwctl.udp_addrlen;
+
+       if (addrlen != sizeof(struct sockaddr_in))
+               return -EAFNOSUPPORT;
+
+       /* */
+       job = kmalloc(GFP_KERNEL, sizeof(*job) + dstcnt*addrlen );
+       if (job == NULL)
+               return -ENOMEM;
+
+       err = copy_from_user(&job->udp_dst, (void __user *)(arg + sizeof(struct cegw_ioctl)), dstcnt*addrlen);
+       if (err != 0) {
+               kfree(job);
+               return -EFAULT;
+       }
+
+       for (i=0; i<dstcnt; i++) {
+               if (job->udp_dst[i].sin_family != AF_INET) {
+                       kfree(job);
+                       return -EAFNOSUPPORT;
+               }
+       }
+
+       job->udp_sock = sockfd_lookup(gwctl.udp_sock, &err);
+       if (job->udp_sock == NULL) {
+               kfree(job);
+               return err;
+       }
+
+       job->can_sock = sockfd_lookup(gwctl.can_sock, &err);
+       if (job->can_sock == NULL) {
+               fput(job->udp_sock->file);
+               kfree(job);
+               return err;
+       }
+
+       job->udp_dstcnt = dstcnt;
+
+       err = cegw_thread_start(job);
+       if (err != 0)
+               return err;
+
+       file->private_data = job;
+       return 0;
+}
+
+static long cegw_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+       int err;
+
+       switch (cmd) {
+               case CEGW_IOCTL_START:
+                       err = cegw_ioctl_start(file, arg);
+                       break;
+               default:
+                       err = -EOPNOTSUPP;
+                       break;
+       }
+
+       return err;
+}
+
+static const struct file_operations cegw_fops = {
+       .owner = THIS_MODULE,
+       .open = cegw_open,
+       .release = cegw_release,
+       .unlocked_ioctl = cegw_ioctl
+};
+
+static struct miscdevice cegw_device = {
+       .minor = MISC_DYNAMIC_MINOR,
+       .name = "canethgw",
+       .fops = &cegw_fops
+};
+
+static int __init cegw_init(void)
+{
+       misc_register(&cegw_device);
+
+       return 0;
+}
+
+static void __exit cegw_exit(void)
+{
+       misc_deregister(&cegw_device);
+
+       return;
+}
+
+module_init(cegw_init);
+module_exit(cegw_exit);
+