arch/um/drivers/mcast_user.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
  14 #include <errno.h>
  15 #include <unistd.h>
  16 #include <sys/socket.h>
  17 #include <sys/un.h>
  18 #include <sys/time.h>
  19 #include <netinet/in.h>
  20 #include "net_user.h"
  21 #include "mcast.h"
  22 #include "kern_util.h"
  23 #include "user_util.h"
  24 #include "user.h"
  25 #include "os.h"
  26 #include "um_malloc.h"
  27
  28 #define MAX_PACKET (ETH_MAX_PACKET + ETH_HEADER_OTHER)
  29
  30 static struct sockaddr_in *new_addr(char *addr, unsigned short port)
  31 {
  32         struct sockaddr_in *sin;
  33
  34         sin = um_kmalloc(sizeof(struct sockaddr_in));
  35         if(sin == NULL){
  36                 printk("new_addr: allocation of sockaddr_in failed\n");
  37                 return(NULL);
  38         }
  39         sin->sin_family = AF_INET;
  40         sin->sin_addr.s_addr = in_aton(addr);
  41         sin->sin_port = htons(port);
  42         return(sin);
  43 }
  44
  45 static void mcast_user_init(void *data, void *dev)
  46 {
  47         struct mcast_data *pri = data;
  48
  49         pri->mcast_addr = new_addr(pri->addr, pri->port);
  50         pri->dev = dev;
  51 }
  52
  53 static int mcast_open(void *data)
  54 {
  55         struct mcast_data *pri = data;
  56         struct sockaddr_in *sin = pri->mcast_addr;
  57         struct ip_mreq mreq;
  58         int fd, yes = 1, err = -EINVAL;
  59
  60
  61         if ((sin->sin_addr.s_addr == 0) || (sin->sin_port == 0))
  62                 goto out;
  63
  64         fd = socket(AF_INET, SOCK_DGRAM, 0);
  65
  66         if (fd < 0){
  67                 err = -errno;
  68                 printk("mcast_open : data socket failed, errno = %d\n",
  69                        errno);
  70                 goto out;
  71         }
  72
  73         if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes)) < 0) {
  74                 err = -errno;
  75                 printk("mcast_open: SO_REUSEADDR failed, errno = %d\n",
  76                         errno);
  77                 goto out_close;
  78         }
  79
  80         /* set ttl according to config */
  81         if (setsockopt(fd, SOL_IP, IP_MULTICAST_TTL, &pri->ttl,
  82                        sizeof(pri->ttl)) < 0) {
  83                 err = -errno;
  84                 printk("mcast_open: IP_MULTICAST_TTL failed, error = %d\n",
  85                         errno);
  86                 goto out_close;
  87         }
  88
  89         /* set LOOP, so data does get fed back to local sockets */
  90         if (setsockopt(fd, SOL_IP, IP_MULTICAST_LOOP, &yes, sizeof(yes)) < 0) {
  91                 err = -errno;
  92                 printk("mcast_open: IP_MULTICAST_LOOP failed, error = %d\n",
  93                         errno);
  94                 goto out_close;
  95         }
  96
  97         /* bind socket to mcast address */
  98         if (bind(fd, (struct sockaddr *) sin, sizeof(*sin)) < 0) {
  99                 err = -errno;
 100                 printk("mcast_open : data bind failed, errno = %d\n", errno);
 101                 goto out_close;
 102         }
 103
 104         /* subscribe to the multicast group */
 105         mreq.imr_multiaddr.s_addr = sin->sin_addr.s_addr;
 106         mreq.imr_interface.s_addr = 0;
 107         if (setsockopt(fd, SOL_IP, IP_ADD_MEMBERSHIP,
 108                        &mreq, sizeof(mreq)) < 0) {
 109                 err = -errno;
 110                 printk("mcast_open: IP_ADD_MEMBERSHIP failed, error = %d\n",
 111                         errno);
 112                 printk("There appears not to be a multicast-capable network "
 113                        "interface on the host.\n");
 114                 printk("eth0 should be configured in order to use the "
 115                        "multicast transport.\n");
 116                 goto out_close;
 117         }
 118
 119         return fd;
 120
 121  out_close:
 122         os_close_file(fd);
 123  out:
 124         return err;
 125 }
 126
 127 static void mcast_close(int fd, void *data)
 128 {
 129         struct ip_mreq mreq;
 130         struct mcast_data *pri = data;
 131         struct sockaddr_in *sin = pri->mcast_addr;
 132
 133         mreq.imr_multiaddr.s_addr = sin->sin_addr.s_addr;
 134         mreq.imr_interface.s_addr = 0;
 135         if (setsockopt(fd, SOL_IP, IP_DROP_MEMBERSHIP,
 136                        &mreq, sizeof(mreq)) < 0) {
 137                 printk("mcast_open: IP_DROP_MEMBERSHIP failed, error = %d\n",
 138                         errno);
 139         }
 140
 141         os_close_file(fd);
 142 }
 143
 144 int mcast_user_write(int fd, void *buf, int len, struct mcast_data *pri)
 145 {
 146         struct sockaddr_in *data_addr = pri->mcast_addr;
 147
 148         return(net_sendto(fd, buf, len, data_addr, sizeof(*data_addr)));
 149 }
 150
 151 static int mcast_set_mtu(int mtu, void *data)
 152 {
 153         return(mtu);
 154 }
 155
 156 const struct net_user_info mcast_user_info = {
 157         .init           = mcast_user_init,
 158         .open           = mcast_open,
 159         .close          = mcast_close,
 160         .remove         = NULL,
 161         .set_mtu        = mcast_set_mtu,
 162         .add_address    = NULL,
 163         .delete_address = NULL,
 164         .max_packet     = MAX_PACKET - ETH_HEADER_OTHER
 165 };