1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * user-mode-linux networking multicast transport |
4 | * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) |
5 | * Copyright (C) 2001 by Harald Welte <laforge@gnumonks.org> |
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 | |
15 | #include <unistd.h> |
16 | #include <errno.h> |
17 | #include <netinet/in.h> |
18 | #include "umcast.h" |
19 | #include <net_user.h> |
20 | #include <um_malloc.h> |
21 | |
22 | static struct sockaddr_in *new_addr(char *addr, unsigned short port) |
23 | { |
24 | struct sockaddr_in *sin; |
25 | |
26 | sin = uml_kmalloc(sizeof(struct sockaddr_in), UM_GFP_KERNEL); |
27 | if (sin == NULL) { |
28 | printk(UM_KERN_ERR "new_addr: allocation of sockaddr_in " |
29 | "failed\n" ); |
30 | return NULL; |
31 | } |
32 | sin->sin_family = AF_INET; |
33 | if (addr) |
34 | sin->sin_addr.s_addr = in_aton(addr); |
35 | else |
36 | sin->sin_addr.s_addr = INADDR_ANY; |
37 | sin->sin_port = htons(port); |
38 | return sin; |
39 | } |
40 | |
41 | static int umcast_user_init(void *data, void *dev) |
42 | { |
43 | struct umcast_data *pri = data; |
44 | |
45 | pri->remote_addr = new_addr(addr: pri->addr, port: pri->rport); |
46 | if (pri->unicast) |
47 | pri->listen_addr = new_addr(addr: NULL, port: pri->lport); |
48 | else |
49 | pri->listen_addr = pri->remote_addr; |
50 | pri->dev = dev; |
51 | return 0; |
52 | } |
53 | |
54 | static void umcast_remove(void *data) |
55 | { |
56 | struct umcast_data *pri = data; |
57 | |
58 | kfree(pri->listen_addr); |
59 | if (pri->unicast) |
60 | kfree(pri->remote_addr); |
61 | pri->listen_addr = pri->remote_addr = NULL; |
62 | } |
63 | |
64 | static int umcast_open(void *data) |
65 | { |
66 | struct umcast_data *pri = data; |
67 | struct sockaddr_in *lsin = pri->listen_addr; |
68 | struct sockaddr_in *rsin = pri->remote_addr; |
69 | struct ip_mreq mreq; |
70 | int fd, yes = 1, err = -EINVAL; |
71 | |
72 | |
73 | if ((!pri->unicast && lsin->sin_addr.s_addr == 0) || |
74 | (rsin->sin_addr.s_addr == 0) || |
75 | (lsin->sin_port == 0) || (rsin->sin_port == 0)) |
76 | goto out; |
77 | |
78 | fd = socket(AF_INET, SOCK_DGRAM, 0); |
79 | |
80 | if (fd < 0) { |
81 | err = -errno; |
82 | printk(UM_KERN_ERR "umcast_open : data socket failed, " |
83 | "errno = %d\n" , errno); |
84 | goto out; |
85 | } |
86 | |
87 | if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes)) < 0) { |
88 | err = -errno; |
89 | printk(UM_KERN_ERR "umcast_open: SO_REUSEADDR failed, " |
90 | "errno = %d\n" , errno); |
91 | goto out_close; |
92 | } |
93 | |
94 | if (!pri->unicast) { |
95 | /* set ttl according to config */ |
96 | if (setsockopt(fd, SOL_IP, IP_MULTICAST_TTL, &pri->ttl, |
97 | sizeof(pri->ttl)) < 0) { |
98 | err = -errno; |
99 | printk(UM_KERN_ERR "umcast_open: IP_MULTICAST_TTL " |
100 | "failed, error = %d\n" , errno); |
101 | goto out_close; |
102 | } |
103 | |
104 | /* set LOOP, so data does get fed back to local sockets */ |
105 | if (setsockopt(fd, SOL_IP, IP_MULTICAST_LOOP, |
106 | &yes, sizeof(yes)) < 0) { |
107 | err = -errno; |
108 | printk(UM_KERN_ERR "umcast_open: IP_MULTICAST_LOOP " |
109 | "failed, error = %d\n" , errno); |
110 | goto out_close; |
111 | } |
112 | } |
113 | |
114 | /* bind socket to the address */ |
115 | if (bind(fd, (struct sockaddr *) lsin, sizeof(*lsin)) < 0) { |
116 | err = -errno; |
117 | printk(UM_KERN_ERR "umcast_open : data bind failed, " |
118 | "errno = %d\n" , errno); |
119 | goto out_close; |
120 | } |
121 | |
122 | if (!pri->unicast) { |
123 | /* subscribe to the multicast group */ |
124 | mreq.imr_multiaddr.s_addr = lsin->sin_addr.s_addr; |
125 | mreq.imr_interface.s_addr = 0; |
126 | if (setsockopt(fd, SOL_IP, IP_ADD_MEMBERSHIP, |
127 | &mreq, sizeof(mreq)) < 0) { |
128 | err = -errno; |
129 | printk(UM_KERN_ERR "umcast_open: IP_ADD_MEMBERSHIP " |
130 | "failed, error = %d\n" , errno); |
131 | printk(UM_KERN_ERR "There appears not to be a " |
132 | "multicast-capable network interface on the " |
133 | "host.\n" ); |
134 | printk(UM_KERN_ERR "eth0 should be configured in order " |
135 | "to use the multicast transport.\n" ); |
136 | goto out_close; |
137 | } |
138 | } |
139 | |
140 | return fd; |
141 | |
142 | out_close: |
143 | close(fd); |
144 | out: |
145 | return err; |
146 | } |
147 | |
148 | static void umcast_close(int fd, void *data) |
149 | { |
150 | struct umcast_data *pri = data; |
151 | |
152 | if (!pri->unicast) { |
153 | struct ip_mreq mreq; |
154 | struct sockaddr_in *lsin = pri->listen_addr; |
155 | |
156 | mreq.imr_multiaddr.s_addr = lsin->sin_addr.s_addr; |
157 | mreq.imr_interface.s_addr = 0; |
158 | if (setsockopt(fd, SOL_IP, IP_DROP_MEMBERSHIP, |
159 | &mreq, sizeof(mreq)) < 0) { |
160 | printk(UM_KERN_ERR "umcast_close: IP_DROP_MEMBERSHIP " |
161 | "failed, error = %d\n" , errno); |
162 | } |
163 | } |
164 | |
165 | close(fd); |
166 | } |
167 | |
168 | int umcast_user_write(int fd, void *buf, int len, struct umcast_data *pri) |
169 | { |
170 | struct sockaddr_in *data_addr = pri->remote_addr; |
171 | |
172 | return net_sendto(fd, buf, len, data_addr, sizeof(*data_addr)); |
173 | } |
174 | |
175 | const struct net_user_info umcast_user_info = { |
176 | .init = umcast_user_init, |
177 | .open = umcast_open, |
178 | .close = umcast_close, |
179 | .remove = umcast_remove, |
180 | .add_address = NULL, |
181 | .delete_address = NULL, |
182 | .mtu = ETH_MAX_PACKET, |
183 | .max_packet = ETH_MAX_PACKET + ETH_HEADER_OTHER, |
184 | }; |
185 | |