arch/um/drivers/umcast_user.c

   1 /*
   2  * user-mode-linux networking multicast transport
   3  * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
   4  * Copyright (C) 2001 by Harald Welte <laforge@gnumonks.org>
   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
  15 #include <unistd.h>
  16 #include <errno.h>
  17 #include <netinet/in.h>
  18 #include "kern_constants.h"
  19 #include "umcast.h"
  20 #include "net_user.h"
  21 #include "um_malloc.h"
  22 #include "user.h"
  23
  24 static struct sockaddr_in *new_addr(char *addr, unsigned short port)
  25 {
  26         struct sockaddr_in *sin;
  27
  28         sin = uml_kmalloc(sizeof(struct sockaddr_in), UM_GFP_KERNEL);
  29         if (sin == NULL) {
  30                 printk(UM_KERN_ERR "new_addr: allocation of sockaddr_in "
  31                        "failed\n");
  32                 return NULL;
  33         }
  34         sin->sin_family = AF_INET;
  35         if (addr)
  36                 sin->sin_addr.s_addr = in_aton(addr);
  37         else
  38                 sin->sin_addr.s_addr = INADDR_ANY;
  39         sin->sin_port = htons(port);
  40         return sin;
  41 }
  42
  43 static int umcast_user_init(void *data, void *dev)
  44 {
  45         struct umcast_data *pri = data;
  46
  47         pri->remote_addr = new_addr(pri->addr, pri->rport);
  48         if (pri->unicast)
  49                 pri->listen_addr = new_addr(NULL, pri->lport);
  50         else
  51                 pri->listen_addr = pri->remote_addr;
  52         pri->dev = dev;
  53         return 0;
  54 }
  55
  56 static void umcast_remove(void *data)
  57 {
  58         struct umcast_data *pri = data;
  59
  60         kfree(pri->listen_addr);
  61         if (pri->unicast)
  62                 kfree(pri->remote_addr);
  63         pri->listen_addr = pri->remote_addr = NULL;
  64 }
  65
  66 static int umcast_open(void *data)
  67 {
  68         struct umcast_data *pri = data;
  69         struct sockaddr_in *lsin = pri->listen_addr;
  70         struct sockaddr_in *rsin = pri->remote_addr;
  71         struct ip_mreq mreq;
  72         int fd, yes = 1, err = -EINVAL;
  73
  74
  75         if ((!pri->unicast && lsin->sin_addr.s_addr == 0) ||
  76             (rsin->sin_addr.s_addr == 0) ||
  77             (lsin->sin_port == 0) || (rsin->sin_port == 0))
  78                 goto out;
  79
  80         fd = socket(AF_INET, SOCK_DGRAM, 0);
  81
  82         if (fd < 0) {
  83                 err = -errno;
  84                 printk(UM_KERN_ERR "umcast_open : data socket failed, "
  85                        "errno = %d\n", errno);
  86                 goto out;
  87         }
  88
  89         if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes)) < 0) {
  90                 err = -errno;
  91                 printk(UM_KERN_ERR "umcast_open: SO_REUSEADDR failed, "
  92                        "errno = %d\n", errno);
  93                 goto out_close;
  94         }
  95
  96         if (!pri->unicast) {
  97                 /* set ttl according to config */
  98                 if (setsockopt(fd, SOL_IP, IP_MULTICAST_TTL, &pri->ttl,
  99                                sizeof(pri->ttl)) < 0) {
 100                         err = -errno;
 101                         printk(UM_KERN_ERR "umcast_open: IP_MULTICAST_TTL "
 102                                "failed, error = %d\n", errno);
 103                         goto out_close;
 104                 }
 105
 106                 /* set LOOP, so data does get fed back to local sockets */
 107                 if (setsockopt(fd, SOL_IP, IP_MULTICAST_LOOP,
 108                                &yes, sizeof(yes)) < 0) {
 109                         err = -errno;
 110                         printk(UM_KERN_ERR "umcast_open: IP_MULTICAST_LOOP "
 111                                "failed, error = %d\n", errno);
 112                         goto out_close;
 113                 }
 114         }
 115
 116         /* bind socket to the address */
 117         if (bind(fd, (struct sockaddr *) lsin, sizeof(*lsin)) < 0) {
 118                 err = -errno;
 119                 printk(UM_KERN_ERR "umcast_open : data bind failed, "
 120                        "errno = %d\n", errno);
 121                 goto out_close;
 122         }
 123
 124         if (!pri->unicast) {
 125                 /* subscribe to the multicast group */
 126                 mreq.imr_multiaddr.s_addr = lsin->sin_addr.s_addr;
 127                 mreq.imr_interface.s_addr = 0;
 128                 if (setsockopt(fd, SOL_IP, IP_ADD_MEMBERSHIP,
 129                                &mreq, sizeof(mreq)) < 0) {
 130                         err = -errno;
 131                         printk(UM_KERN_ERR "umcast_open: IP_ADD_MEMBERSHIP "
 132                                "failed, error = %d\n", errno);
 133                         printk(UM_KERN_ERR "There appears not to be a "
 134                                "multicast-capable network interface on the "
 135                                "host.\n");
 136                         printk(UM_KERN_ERR "eth0 should be configured in order "
 137                                "to use the multicast transport.\n");
 138                         goto out_close;
 139                 }
 140         }
 141
 142         return fd;
 143
 144  out_close:
 145         close(fd);
 146  out:
 147         return err;
 148 }
 149
 150 static void umcast_close(int fd, void *data)
 151 {
 152         struct umcast_data *pri = data;
 153
 154         if (!pri->unicast) {
 155                 struct ip_mreq mreq;
 156                 struct sockaddr_in *lsin = pri->listen_addr;
 157
 158                 mreq.imr_multiaddr.s_addr = lsin->sin_addr.s_addr;
 159                 mreq.imr_interface.s_addr = 0;
 160                 if (setsockopt(fd, SOL_IP, IP_DROP_MEMBERSHIP,
 161                                &mreq, sizeof(mreq)) < 0) {
 162                         printk(UM_KERN_ERR "umcast_close: IP_DROP_MEMBERSHIP "
 163                                "failed, error = %d\n", errno);
 164                 }
 165         }
 166
 167         close(fd);
 168 }
 169
 170 int umcast_user_write(int fd, void *buf, int len, struct umcast_data *pri)
 171 {
 172         struct sockaddr_in *data_addr = pri->remote_addr;
 173
 174         return net_sendto(fd, buf, len, data_addr, sizeof(*data_addr));
 175 }
 176
 177 const struct net_user_info umcast_user_info = {
 178         .init   = umcast_user_init,
 179         .open   = umcast_open,
 180         .close  = umcast_close,
 181         .remove = umcast_remove,
 182         .add_address    = NULL,
 183         .delete_address = NULL,
 184         .mtu    = ETH_MAX_PACKET,
 185         .max_packet     = ETH_MAX_PACKET + ETH_HEADER_OTHER,
 186 };