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