arch/um/drivers/mcast_kern.c

   1 /*
   2  * user-mode-linux networking multicast transport
   3  * Copyright (C) 2001 by Harald Welte <laforge@gnumonks.org>
   4  * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
   5  *
   6  * based on the existing uml-networking code, which is
   7  * Copyright (C) 2001 Lennert Buytenhek (buytenh@gnu.org) and
   8  * James Leu (jleu@mindspring.net).
   9  * Copyright (C) 2001 by various other people who didn't put their name here.
  10  *
  11  * Licensed under the GPL.
  12  */
  13
  14 #include "linux/init.h"
  15 #include <linux/netdevice.h>
  16 #include "mcast.h"
  17 #include "net_kern.h"
  18
  19 struct mcast_init {
  20         char *addr;
  21         int port;
  22         int ttl;
  23 };
  24
  25 static void mcast_init(struct net_device *dev, void *data)
  26 {
  27         struct uml_net_private *pri;
  28         struct mcast_data *dpri;
  29         struct mcast_init *init = data;
  30
  31         pri = dev->priv;
  32         dpri = (struct mcast_data *) pri->user;
  33         dpri->addr = init->addr;
  34         dpri->port = init->port;
  35         dpri->ttl = init->ttl;
  36         dpri->dev = dev;
  37
  38         printk("mcast backend multicast address: %s:%u, TTL:%u\n",
  39                dpri->addr, dpri->port, dpri->ttl);
  40 }
  41
  42 static int mcast_read(int fd, struct sk_buff **skb, struct uml_net_private *lp)
  43 {
  44         *skb = ether_adjust_skb(*skb, ETH_HEADER_OTHER);
  45         if (*skb == NULL)
  46                 return -ENOMEM;
  47         return net_recvfrom(fd, skb_mac_header(*skb),
  48                             (*skb)->dev->mtu + ETH_HEADER_OTHER);
  49 }
  50
  51 static int mcast_write(int fd, struct sk_buff **skb, struct uml_net_private *lp)
  52 {
  53         return mcast_user_write(fd, (*skb)->data, (*skb)->len,
  54                                 (struct mcast_data *) &lp->user);
  55 }
  56
  57 static const struct net_kern_info mcast_kern_info = {
  58         .init                   = mcast_init,
  59         .protocol               = eth_protocol,
  60         .read                   = mcast_read,
  61         .write                  = mcast_write,
  62 };
  63
  64 int mcast_setup(char *str, char **mac_out, void *data)
  65 {
  66         struct mcast_init *init = data;
  67         char *port_str = NULL, *ttl_str = NULL, *remain;
  68         char *last;
  69
  70         *init = ((struct mcast_init)
  71                 { .addr         = "239.192.168.1",
  72                   .port         = 1102,
  73                   .ttl          = 1 });
  74
  75         remain = split_if_spec(str, mac_out, &init->addr, &port_str, &ttl_str,
  76                                NULL);
  77         if (remain != NULL) {
  78                 printk(KERN_ERR "mcast_setup - Extra garbage on "
  79                        "specification : '%s'\n", remain);
  80                 return 0;
  81         }
  82
  83         if (port_str != NULL) {
  84                 init->port = simple_strtoul(port_str, &last, 10);
  85                 if ((*last != '\0') || (last == port_str)) {
  86                         printk(KERN_ERR "mcast_setup - Bad port : '%s'\n",
  87                                port_str);
  88                         return 0;
  89                 }
  90         }
  91
  92         if (ttl_str != NULL) {
  93                 init->ttl = simple_strtoul(ttl_str, &last, 10);
  94                 if ((*last != '\0') || (last == ttl_str)) {
  95                         printk(KERN_ERR "mcast_setup - Bad ttl : '%s'\n",
  96                                ttl_str);
  97                         return 0;
  98                 }
  99         }
 100
 101         printk(KERN_INFO "Configured mcast device: %s:%u-%u\n", init->addr,
 102                init->port, init->ttl);
 103
 104         return 1;
 105 }
 106
 107 static struct transport mcast_transport = {
 108         .list           = LIST_HEAD_INIT(mcast_transport.list),
 109         .name           = "mcast",
 110         .setup          = mcast_setup,
 111         .user           = &mcast_user_info,
 112         .kern           = &mcast_kern_info,
 113         .private_size   = sizeof(struct mcast_data),
 114         .setup_size     = sizeof(struct mcast_init),
 115 };
 116
 117 static int register_mcast(void)
 118 {
 119         register_transport(&mcast_transport);
 120         return 0;
 121 }
 122
 123 late_initcall(register_mcast);