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.h"
  24 #include "os.h"
  25 #include "um_malloc.h"
  26
  27 #define MAX_PACKET (ETH_MAX_PACKET + ETH_HEADER_OTHER)
  28
  29 static struct sockaddr_in *new_addr(char *addr, unsigned short port)
  30 {
  31         struct sockaddr_in *sin;
  32
  33         sin = um_kmalloc(sizeof(struct sockaddr_in));
  34         if(sin == NULL){
  35                 printk("new_addr: allocation of sockaddr_in failed\n");
  36                 return NULL;
  37         }
  38         sin->sin_family = AF_INET;
  39         sin->sin_addr.s_addr = in_aton(addr);
  40         sin->sin_port = htons(port);
  41         return sin;
  42 }
  43
  44 static int mcast_user_init(void *data, void *dev)
  45 {
  46         struct mcast_data *pri = data;
  47
  48         pri->mcast_addr = new_addr(pri->addr, pri->port);
  49         pri->dev = dev;
  50         return 0;
  51 }
  52
  53 static void mcast_remove(void *data)
  54 {
  55         struct mcast_data *pri = data;
  56
  57         kfree(pri->mcast_addr);
  58         pri->mcast_addr = NULL;
  59 }
  60
  61 static int mcast_open(void *data)
  62 {
  63         struct mcast_data *pri = data;
  64         struct sockaddr_in *sin = pri->mcast_addr;
  65         struct ip_mreq mreq;
  66         int fd, yes = 1, err = -EINVAL;
  67
  68
  69         if ((sin->sin_addr.s_addr == 0) || (sin->sin_port == 0))
  70                 goto out;
  71
  72         fd = socket(AF_INET, SOCK_DGRAM, 0);
  73
  74         if (fd < 0){
  75                 err = -errno;
  76                 printk("mcast_open : data socket failed, errno = %d\n",
  77                        errno);
  78                 goto out;
  79         }
  80
  81         if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes)) < 0) {
  82                 err = -errno;
  83                 printk("mcast_open: SO_REUSEADDR failed, errno = %d\n",
  84                         errno);
  85                 goto out_close;
  86         }
  87
  88         /* set ttl according to config */
  89         if (setsockopt(fd, SOL_IP, IP_MULTICAST_TTL, &pri->ttl,
  90                        sizeof(pri->ttl)) < 0) {
  91                 err = -errno;
  92                 printk("mcast_open: IP_MULTICAST_TTL failed, error = %d\n",
  93                         errno);
  94                 goto out_close;
  95         }
  96
  97         /* set LOOP, so data does get fed back to local sockets */
  98         if (setsockopt(fd, SOL_IP, IP_MULTICAST_LOOP, &yes, sizeof(yes)) < 0) {
  99                 err = -errno;
 100                 printk("mcast_open: IP_MULTICAST_LOOP failed, error = %d\n",
 101                         errno);
 102                 goto out_close;
 103         }
 104
 105         /* bind socket to mcast address */
 106         if (bind(fd, (struct sockaddr *) sin, sizeof(*sin)) < 0) {
 107                 err = -errno;
 108                 printk("mcast_open : data bind failed, errno = %d\n", errno);
 109                 goto out_close;
 110         }
 111
 112         /* subscribe to the multicast group */
 113         mreq.imr_multiaddr.s_addr = sin->sin_addr.s_addr;
 114         mreq.imr_interface.s_addr = 0;
 115         if (setsockopt(fd, SOL_IP, IP_ADD_MEMBERSHIP,
 116                        &mreq, sizeof(mreq)) < 0) {
 117                 err = -errno;
 118                 printk("mcast_open: IP_ADD_MEMBERSHIP failed, error = %d\n",
 119                         errno);
 120                 printk("There appears not to be a multicast-capable network "
 121                        "interface on the host.\n");
 122                 printk("eth0 should be configured in order to use the "
 123                        "multicast transport.\n");
 124                 goto out_close;
 125         }
 126
 127         return fd;
 128
 129  out_close:
 130         os_close_file(fd);
 131  out:
 132         return err;
 133 }
 134
 135 static void mcast_close(int fd, void *data)
 136 {
 137         struct ip_mreq mreq;
 138         struct mcast_data *pri = data;
 139         struct sockaddr_in *sin = pri->mcast_addr;
 140
 141         mreq.imr_multiaddr.s_addr = sin->sin_addr.s_addr;
 142         mreq.imr_interface.s_addr = 0;
 143         if (setsockopt(fd, SOL_IP, IP_DROP_MEMBERSHIP,
 144                        &mreq, sizeof(mreq)) < 0) {
 145                 printk("mcast_open: IP_DROP_MEMBERSHIP failed, error = %d\n",
 146                         errno);
 147         }
 148
 149         os_close_file(fd);
 150 }
 151
 152 int mcast_user_write(int fd, void *buf, int len, struct mcast_data *pri)
 153 {
 154         struct sockaddr_in *data_addr = pri->mcast_addr;
 155
 156         return net_sendto(fd, buf, len, data_addr, sizeof(*data_addr));
 157 }
 158
 159 static int mcast_set_mtu(int mtu, void *data)
 160 {
 161         return mtu;
 162 }
 163
 164 const struct net_user_info mcast_user_info = {
 165         .init           = mcast_user_init,
 166         .open           = mcast_open,
 167         .close          = mcast_close,
 168         .remove         = mcast_remove,
 169         .set_mtu        = mcast_set_mtu,
 170         .add_address    = NULL,
 171         .delete_address = NULL,
 172         .max_packet     = MAX_PACKET - ETH_HEADER_OTHER
 173 };