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 29static 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 44static 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 53static 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 61static 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 135static 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 152int 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 159static int mcast_set_mtu(int mtu, void *data) 160{ 161 return mtu; 162} 163 164const 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}; 174