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