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 "mcast.h" 20#include "net_user.h" 21#include "um_malloc.h" 22#include "user.h" 23 24static 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 sin->sin_addr.s_addr = in_aton(addr); 36 sin->sin_port = htons(port); 37 return sin; 38} 39 40static int mcast_user_init(void *data, void *dev) 41{ 42 struct mcast_data *pri = data; 43 44 pri->mcast_addr = new_addr(pri->addr, pri->port); 45 pri->dev = dev; 46 return 0; 47} 48 49static void mcast_remove(void *data) 50{ 51 struct mcast_data *pri = data; 52 53 kfree(pri->mcast_addr); 54 pri->mcast_addr = NULL; 55} 56 57static int mcast_open(void *data) 58{ 59 struct mcast_data *pri = data; 60 struct sockaddr_in *sin = pri->mcast_addr; 61 struct ip_mreq mreq; 62 int fd, yes = 1, err = -EINVAL; 63 64 65 if ((sin->sin_addr.s_addr == 0) || (sin->sin_port == 0)) 66 goto out; 67 68 fd = socket(AF_INET, SOCK_DGRAM, 0); 69 70 if (fd < 0) { 71 err = -errno; 72 printk(UM_KERN_ERR "mcast_open : data socket failed, " 73 "errno = %d\n", errno); 74 goto out; 75 } 76 77 if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes)) < 0) { 78 err = -errno; 79 printk(UM_KERN_ERR "mcast_open: SO_REUSEADDR failed, " 80 "errno = %d\n", errno); 81 goto out_close; 82 } 83 84 /* set ttl according to config */ 85 if (setsockopt(fd, SOL_IP, IP_MULTICAST_TTL, &pri->ttl, 86 sizeof(pri->ttl)) < 0) { 87 err = -errno; 88 printk(UM_KERN_ERR "mcast_open: IP_MULTICAST_TTL failed, " 89 "error = %d\n", errno); 90 goto out_close; 91 } 92 93 /* set LOOP, so data does get fed back to local sockets */ 94 if (setsockopt(fd, SOL_IP, IP_MULTICAST_LOOP, &yes, sizeof(yes)) < 0) { 95 err = -errno; 96 printk(UM_KERN_ERR "mcast_open: IP_MULTICAST_LOOP failed, " 97 "error = %d\n", errno); 98 goto out_close; 99 } 100 101 /* bind socket to mcast address */ 102 if (bind(fd, (struct sockaddr *) sin, sizeof(*sin)) < 0) { 103 err = -errno; 104 printk(UM_KERN_ERR "mcast_open : data bind failed, " 105 "errno = %d\n", errno); 106 goto out_close; 107 } 108 109 /* subscribe to the multicast group */ 110 mreq.imr_multiaddr.s_addr = sin->sin_addr.s_addr; 111 mreq.imr_interface.s_addr = 0; 112 if (setsockopt(fd, SOL_IP, IP_ADD_MEMBERSHIP, 113 &mreq, sizeof(mreq)) < 0) { 114 err = -errno; 115 printk(UM_KERN_ERR "mcast_open: IP_ADD_MEMBERSHIP failed, " 116 "error = %d\n", errno); 117 printk(UM_KERN_ERR "There appears not to be a multicast-" 118 "capable network interface on the host.\n"); 119 printk(UM_KERN_ERR "eth0 should be configured in order to use " 120 "the multicast transport.\n"); 121 goto out_close; 122 } 123 124 return fd; 125 126 out_close: 127 close(fd); 128 out: 129 return err; 130} 131 132static void mcast_close(int fd, void *data) 133{ 134 struct ip_mreq mreq; 135 struct mcast_data *pri = data; 136 struct sockaddr_in *sin = pri->mcast_addr; 137 138 mreq.imr_multiaddr.s_addr = sin->sin_addr.s_addr; 139 mreq.imr_interface.s_addr = 0; 140 if (setsockopt(fd, SOL_IP, IP_DROP_MEMBERSHIP, 141 &mreq, sizeof(mreq)) < 0) { 142 printk(UM_KERN_ERR "mcast_open: IP_DROP_MEMBERSHIP failed, " 143 "error = %d\n", errno); 144 } 145 146 close(fd); 147} 148 149int mcast_user_write(int fd, void *buf, int len, struct mcast_data *pri) 150{ 151 struct sockaddr_in *data_addr = pri->mcast_addr; 152 153 return net_sendto(fd, buf, len, data_addr, sizeof(*data_addr)); 154} 155 156const struct net_user_info mcast_user_info = { 157 .init = mcast_user_init, 158 .open = mcast_open, 159 .close = mcast_close, 160 .remove = mcast_remove, 161 .add_address = NULL, 162 .delete_address = NULL, 163 .mtu = ETH_MAX_PACKET, 164 .max_packet = ETH_MAX_PACKET + ETH_HEADER_OTHER, 165}; 166