/* * user-mode-linux networking multicast transport * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) * Copyright (C) 2001 by Harald Welte <laforge@gnumonks.org> * * based on the existing uml-networking code, which is * Copyright (C) 2001 Lennert Buytenhek (buytenh@gnu.org) and * James Leu (jleu@mindspring.net). * Copyright (C) 2001 by various other people who didn't put their name here. * * Licensed under the GPL. * */ #include <unistd.h> #include <errno.h> #include <netinet/in.h> #include "kern_constants.h" #include "mcast.h" #include "net_user.h" #include "um_malloc.h" #include "user.h" static struct sockaddr_in *new_addr(char *addr, unsigned short port) { struct sockaddr_in *sin; sin = uml_kmalloc(sizeof(struct sockaddr_in), UM_GFP_KERNEL); if (sin == NULL) { printk(UM_KERN_ERR "new_addr: allocation of sockaddr_in " "failed\n"); return NULL; } sin->sin_family = AF_INET; sin->sin_addr.s_addr = in_aton(addr); sin->sin_port = htons(port); return sin; } static int mcast_user_init(void *data, void *dev) { struct mcast_data *pri = data; pri->mcast_addr = new_addr(pri->addr, pri->port); pri->dev = dev; return 0; } static void mcast_remove(void *data) { struct mcast_data *pri = data; kfree(pri->mcast_addr); pri->mcast_addr = NULL; } static int mcast_open(void *data) { struct mcast_data *pri = data; struct sockaddr_in *sin = pri->mcast_addr; struct ip_mreq mreq; int fd, yes = 1, err = -EINVAL; if ((sin->sin_addr.s_addr == 0) || (sin->sin_port == 0)) goto out; fd = socket(AF_INET, SOCK_DGRAM, 0); if (fd < 0) { err = -errno; printk(UM_KERN_ERR "mcast_open : data socket failed, " "errno = %d\n", errno); goto out; } if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes)) < 0) { err = -errno; printk(UM_KERN_ERR "mcast_open: SO_REUSEADDR failed, " "errno = %d\n", errno); goto out_close; } /* set ttl according to config */ if (setsockopt(fd, SOL_IP, IP_MULTICAST_TTL, &pri->ttl, sizeof(pri->ttl)) < 0) { err = -errno; printk(UM_KERN_ERR "mcast_open: IP_MULTICAST_TTL failed, " "error = %d\n", errno); goto out_close; } /* set LOOP, so data does get fed back to local sockets */ if (setsockopt(fd, SOL_IP, IP_MULTICAST_LOOP, &yes, sizeof(yes)) < 0) { err = -errno; printk(UM_KERN_ERR "mcast_open: IP_MULTICAST_LOOP failed, " "error = %d\n", errno); goto out_close; } /* bind socket to mcast address */ if (bind(fd, (struct sockaddr *) sin, sizeof(*sin)) < 0) { err = -errno; printk(UM_KERN_ERR "mcast_open : data bind failed, " "errno = %d\n", errno); goto out_close; } /* subscribe to the multicast group */ mreq.imr_multiaddr.s_addr = sin->sin_addr.s_addr; mreq.imr_interface.s_addr = 0; if (setsockopt(fd, SOL_IP, IP_ADD_MEMBERSHIP, &mreq, sizeof(mreq)) < 0) { err = -errno; printk(UM_KERN_ERR "mcast_open: IP_ADD_MEMBERSHIP failed, " "error = %d\n", errno); printk(UM_KERN_ERR "There appears not to be a multicast-" "capable network interface on the host.\n"); printk(UM_KERN_ERR "eth0 should be configured in order to use " "the multicast transport.\n"); goto out_close; } return fd; out_close: close(fd); out: return err; } static void mcast_close(int fd, void *data) { struct ip_mreq mreq; struct mcast_data *pri = data; struct sockaddr_in *sin = pri->mcast_addr; mreq.imr_multiaddr.s_addr = sin->sin_addr.s_addr; mreq.imr_interface.s_addr = 0; if (setsockopt(fd, SOL_IP, IP_DROP_MEMBERSHIP, &mreq, sizeof(mreq)) < 0) { printk(UM_KERN_ERR "mcast_open: IP_DROP_MEMBERSHIP failed, " "error = %d\n", errno); } close(fd); } int mcast_user_write(int fd, void *buf, int len, struct mcast_data *pri) { struct sockaddr_in *data_addr = pri->mcast_addr; return net_sendto(fd, buf, len, data_addr, sizeof(*data_addr)); } const struct net_user_info mcast_user_info = { .init = mcast_user_init, .open = mcast_open, .close = mcast_close, .remove = mcast_remove, .add_address = NULL, .delete_address = NULL, .mtu = ETH_MAX_PACKET, .max_packet = ETH_MAX_PACKET + ETH_HEADER_OTHER, };