1// SPDX-License-Identifier: GPL-2.0
2/*
3 * user-mode-linux networking multicast transport
4 * Copyright (C) 2001 by Harald Welte <laforge@gnumonks.org>
5 * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
6 *
7 * based on the existing uml-networking code, which is
8 * Copyright (C) 2001 Lennert Buytenhek (buytenh@gnu.org) and
9 * James Leu (jleu@mindspring.net).
10 * Copyright (C) 2001 by various other people who didn't put their name here.
11 *
12 */
13
14#include <linux/init.h>
15#include <linux/netdevice.h>
16#include "umcast.h"
17#include <net_kern.h>
18
19struct umcast_init {
20 char *addr;
21 int lport;
22 int rport;
23 int ttl;
24 bool unicast;
25};
26
27static void umcast_init(struct net_device *dev, void *data)
28{
29 struct uml_net_private *pri;
30 struct umcast_data *dpri;
31 struct umcast_init *init = data;
32
33 pri = netdev_priv(dev);
34 dpri = (struct umcast_data *) pri->user;
35 dpri->addr = init->addr;
36 dpri->lport = init->lport;
37 dpri->rport = init->rport;
38 dpri->unicast = init->unicast;
39 dpri->ttl = init->ttl;
40 dpri->dev = dev;
41
42 if (dpri->unicast) {
43 printk(KERN_INFO "ucast backend address: %s:%u listen port: "
44 "%u\n", dpri->addr, dpri->rport, dpri->lport);
45 } else {
46 printk(KERN_INFO "mcast backend multicast address: %s:%u, "
47 "TTL:%u\n", dpri->addr, dpri->lport, dpri->ttl);
48 }
49}
50
51static int umcast_read(int fd, struct sk_buff *skb, struct uml_net_private *lp)
52{
53 return net_recvfrom(fd, skb_mac_header(skb),
54 skb->dev->mtu + ETH_HEADER_OTHER);
55}
56
57static int umcast_write(int fd, struct sk_buff *skb, struct uml_net_private *lp)
58{
59 return umcast_user_write(fd, buf: skb->data, len: skb->len,
60 pri: (struct umcast_data *) &lp->user);
61}
62
63static const struct net_kern_info umcast_kern_info = {
64 .init = umcast_init,
65 .protocol = eth_protocol,
66 .read = umcast_read,
67 .write = umcast_write,
68};
69
70static int mcast_setup(char *str, char **mac_out, void *data)
71{
72 struct umcast_init *init = data;
73 char *port_str = NULL, *ttl_str = NULL, *remain;
74 char *last;
75
76 *init = ((struct umcast_init)
77 { .addr = "239.192.168.1",
78 .lport = 1102,
79 .ttl = 1 });
80
81 remain = split_if_spec(str, mac_out, &init->addr, &port_str, &ttl_str,
82 NULL);
83 if (remain != NULL) {
84 printk(KERN_ERR "mcast_setup - Extra garbage on "
85 "specification : '%s'\n", remain);
86 return 0;
87 }
88
89 if (port_str != NULL) {
90 init->lport = simple_strtoul(port_str, &last, 10);
91 if ((*last != '\0') || (last == port_str)) {
92 printk(KERN_ERR "mcast_setup - Bad port : '%s'\n",
93 port_str);
94 return 0;
95 }
96 }
97
98 if (ttl_str != NULL) {
99 init->ttl = simple_strtoul(ttl_str, &last, 10);
100 if ((*last != '\0') || (last == ttl_str)) {
101 printk(KERN_ERR "mcast_setup - Bad ttl : '%s'\n",
102 ttl_str);
103 return 0;
104 }
105 }
106
107 init->unicast = false;
108 init->rport = init->lport;
109
110 printk(KERN_INFO "Configured mcast device: %s:%u-%u\n", init->addr,
111 init->lport, init->ttl);
112
113 return 1;
114}
115
116static int ucast_setup(char *str, char **mac_out, void *data)
117{
118 struct umcast_init *init = data;
119 char *lport_str = NULL, *rport_str = NULL, *remain;
120 char *last;
121
122 *init = ((struct umcast_init)
123 { .addr = "",
124 .lport = 1102,
125 .rport = 1102 });
126
127 remain = split_if_spec(str, mac_out, &init->addr,
128 &lport_str, &rport_str, NULL);
129 if (remain != NULL) {
130 printk(KERN_ERR "ucast_setup - Extra garbage on "
131 "specification : '%s'\n", remain);
132 return 0;
133 }
134
135 if (lport_str != NULL) {
136 init->lport = simple_strtoul(lport_str, &last, 10);
137 if ((*last != '\0') || (last == lport_str)) {
138 printk(KERN_ERR "ucast_setup - Bad listen port : "
139 "'%s'\n", lport_str);
140 return 0;
141 }
142 }
143
144 if (rport_str != NULL) {
145 init->rport = simple_strtoul(rport_str, &last, 10);
146 if ((*last != '\0') || (last == rport_str)) {
147 printk(KERN_ERR "ucast_setup - Bad remote port : "
148 "'%s'\n", rport_str);
149 return 0;
150 }
151 }
152
153 init->unicast = true;
154
155 printk(KERN_INFO "Configured ucast device: :%u -> %s:%u\n",
156 init->lport, init->addr, init->rport);
157
158 return 1;
159}
160
161static struct transport mcast_transport = {
162 .list = LIST_HEAD_INIT(mcast_transport.list),
163 .name = "mcast",
164 .setup = mcast_setup,
165 .user = &umcast_user_info,
166 .kern = &umcast_kern_info,
167 .private_size = sizeof(struct umcast_data),
168 .setup_size = sizeof(struct umcast_init),
169};
170
171static struct transport ucast_transport = {
172 .list = LIST_HEAD_INIT(ucast_transport.list),
173 .name = "ucast",
174 .setup = ucast_setup,
175 .user = &umcast_user_info,
176 .kern = &umcast_kern_info,
177 .private_size = sizeof(struct umcast_data),
178 .setup_size = sizeof(struct umcast_init),
179};
180
181static int register_umcast(void)
182{
183 register_transport(&mcast_transport);
184 register_transport(&ucast_transport);
185 return 0;
186}
187
188late_initcall(register_umcast);
189

source code of linux/arch/um/drivers/umcast_kern.c