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  *
   5  * based on the existing uml-networking code, which is
   6  * Copyright (C) 2001 Lennert Buytenhek (buytenh@gnu.org) and
   7  * James Leu (jleu@mindspring.net).
   8  * Copyright (C) 2001 by various other people who didn't put their name here.
   9  *
  10  * Licensed under the GPL.
  11  */
  12
  13 #include "linux/kernel.h"
  14 #include "linux/init.h"
  15 #include "linux/netdevice.h"
  16 #include "linux/etherdevice.h"
  17 #include "linux/in.h"
  18 #include "linux/inet.h"
  19 #include "net_kern.h"
  20 #include "net_user.h"
  21 #include "mcast.h"
  22
  23 struct mcast_init {
  24         char *addr;
  25         int port;
  26         int ttl;
  27 };
  28
  29 static void mcast_init(struct net_device *dev, void *data)
  30 {
  31         struct uml_net_private *pri;
  32         struct mcast_data *dpri;
  33         struct mcast_init *init = data;
  34
  35         pri = dev->priv;
  36         dpri = (struct mcast_data *) pri->user;
  37         dpri->addr = init->addr;
  38         dpri->port = init->port;
  39         dpri->ttl = init->ttl;
  40         dpri->dev = dev;
  41
  42         printk("mcast backend ");
  43         printk("multicast address: %s:%u, TTL:%u ",
  44                dpri->addr, dpri->port, dpri->ttl);
  45
  46         printk("\n");
  47 }
  48
  49 static int mcast_read(int fd, struct sk_buff **skb, struct uml_net_private *lp)
  50 {
  51         *skb = ether_adjust_skb(*skb, ETH_HEADER_OTHER);
  52         if(*skb == NULL) return(-ENOMEM);
  53         return(net_recvfrom(fd, (*skb)->mac.raw,
  54                             (*skb)->dev->mtu + ETH_HEADER_OTHER));
  55 }
  56
  57 static int mcast_write(int fd, struct sk_buff **skb,
  58                         struct uml_net_private *lp)
  59 {
  60         return mcast_user_write(fd, (*skb)->data, (*skb)->len,
  61                                  (struct mcast_data *) &lp->user);
  62 }
  63
  64 static const struct net_kern_info mcast_kern_info = {
  65         .init                   = mcast_init,
  66         .protocol               = eth_protocol,
  67         .read                   = mcast_read,
  68         .write                  = mcast_write,
  69 };
  70
  71 int mcast_setup(char *str, char **mac_out, void *data)
  72 {
  73         struct mcast_init *init = data;
  74         char *port_str = NULL, *ttl_str = NULL, *remain;
  75         char *last;
  76
  77         *init = ((struct mcast_init)
  78                 { .addr         = "239.192.168.1",
  79                   .port         = 1102,
  80                   .ttl          = 1 });
  81
  82         remain = split_if_spec(str, mac_out, &init->addr, &port_str, &ttl_str,
  83                                NULL);
  84         if(remain != NULL){
  85                 printk(KERN_ERR "mcast_setup - Extra garbage on "
  86                        "specification : '%s'\n", remain);
  87                 return(0);
  88         }
  89
  90         if(port_str != NULL){
  91                 init->port = simple_strtoul(port_str, &last, 10);
  92                 if((*last != '\0') || (last == port_str)){
  93                         printk(KERN_ERR "mcast_setup - Bad port : '%s'\n",
  94                                port_str);
  95                         return(0);
  96                 }
  97         }
  98
  99         if(ttl_str != NULL){
 100                 init->ttl = simple_strtoul(ttl_str, &last, 10);
 101                 if((*last != '\0') || (last == ttl_str)){
 102                         printk(KERN_ERR "mcast_setup - Bad ttl : '%s'\n",
 103                                ttl_str);
 104                         return(0);
 105                 }
 106         }
 107
 108         printk(KERN_INFO "Configured mcast device: %s:%u-%u\n", init->addr,
 109                init->port, init->ttl);
 110
 111         return(1);
 112 }
 113
 114 static struct transport mcast_transport = {
 115         .list           = LIST_HEAD_INIT(mcast_transport.list),
 116         .name           = "mcast",
 117         .setup          = mcast_setup,
 118         .user           = &mcast_user_info,
 119         .kern           = &mcast_kern_info,
 120         .private_size   = sizeof(struct mcast_data),
 121         .setup_size     = sizeof(struct mcast_init),
 122 };
 123
 124 static int register_mcast(void)
 125 {
 126         register_transport(&mcast_transport);
 127         return 0;
 128 }
 129
 130 __initcall(register_mcast);