xref: /linux/arch/um/drivers/daemon_user.c (revision 132db93572821ec2fdf81e354cc40f558faf7e4f)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
4  * Copyright (C) 2001 Lennert Buytenhek (buytenh@gnu.org) and
5  * James Leu (jleu@mindspring.net).
6  * Copyright (C) 2001 by various other people who didn't put their name here.
7  */
8 
9 #include <stdint.h>
10 #include <unistd.h>
11 #include <errno.h>
12 #include <sys/types.h>
13 #include <sys/socket.h>
14 #include <sys/time.h>
15 #include <sys/un.h>
16 #include "daemon.h"
17 #include <net_user.h>
18 #include <os.h>
19 #include <um_malloc.h>
20 
21 enum request_type { REQ_NEW_CONTROL };
22 
23 #define SWITCH_MAGIC 0xfeedface
24 
25 struct request_v3 {
26 	uint32_t magic;
27 	uint32_t version;
28 	enum request_type type;
29 	struct sockaddr_un sock;
30 };
31 
32 static struct sockaddr_un *new_addr(void *name, int len)
33 {
34 	struct sockaddr_un *sun;
35 
36 	sun = uml_kmalloc(sizeof(struct sockaddr_un), UM_GFP_KERNEL);
37 	if (sun == NULL) {
38 		printk(UM_KERN_ERR "new_addr: allocation of sockaddr_un "
39 		       "failed\n");
40 		return NULL;
41 	}
42 	sun->sun_family = AF_UNIX;
43 	memcpy(sun->sun_path, name, len);
44 	return sun;
45 }
46 
47 static int connect_to_switch(struct daemon_data *pri)
48 {
49 	struct sockaddr_un *ctl_addr = pri->ctl_addr;
50 	struct sockaddr_un *local_addr = pri->local_addr;
51 	struct sockaddr_un *sun;
52 	struct request_v3 req;
53 	int fd, n, err;
54 
55 	pri->control = socket(AF_UNIX, SOCK_STREAM, 0);
56 	if (pri->control < 0) {
57 		err = -errno;
58 		printk(UM_KERN_ERR "daemon_open : control socket failed, "
59 		       "errno = %d\n", -err);
60 		return err;
61 	}
62 
63 	if (connect(pri->control, (struct sockaddr *) ctl_addr,
64 		   sizeof(*ctl_addr)) < 0) {
65 		err = -errno;
66 		printk(UM_KERN_ERR "daemon_open : control connect failed, "
67 		       "errno = %d\n", -err);
68 		goto out;
69 	}
70 
71 	fd = socket(AF_UNIX, SOCK_DGRAM, 0);
72 	if (fd < 0) {
73 		err = -errno;
74 		printk(UM_KERN_ERR "daemon_open : data socket failed, "
75 		       "errno = %d\n", -err);
76 		goto out;
77 	}
78 	if (bind(fd, (struct sockaddr *) local_addr, sizeof(*local_addr)) < 0) {
79 		err = -errno;
80 		printk(UM_KERN_ERR "daemon_open : data bind failed, "
81 		       "errno = %d\n", -err);
82 		goto out_close;
83 	}
84 
85 	sun = uml_kmalloc(sizeof(struct sockaddr_un), UM_GFP_KERNEL);
86 	if (sun == NULL) {
87 		printk(UM_KERN_ERR "new_addr: allocation of sockaddr_un "
88 		       "failed\n");
89 		err = -ENOMEM;
90 		goto out_close;
91 	}
92 
93 	req.magic = SWITCH_MAGIC;
94 	req.version = SWITCH_VERSION;
95 	req.type = REQ_NEW_CONTROL;
96 	req.sock = *local_addr;
97 	n = write(pri->control, &req, sizeof(req));
98 	if (n != sizeof(req)) {
99 		printk(UM_KERN_ERR "daemon_open : control setup request "
100 		       "failed, err = %d\n", -errno);
101 		err = -ENOTCONN;
102 		goto out_free;
103 	}
104 
105 	n = read(pri->control, sun, sizeof(*sun));
106 	if (n != sizeof(*sun)) {
107 		printk(UM_KERN_ERR "daemon_open : read of data socket failed, "
108 		       "err = %d\n", -errno);
109 		err = -ENOTCONN;
110 		goto out_free;
111 	}
112 
113 	pri->data_addr = sun;
114 	return fd;
115 
116  out_free:
117 	kfree(sun);
118  out_close:
119 	close(fd);
120  out:
121 	close(pri->control);
122 	return err;
123 }
124 
125 static int daemon_user_init(void *data, void *dev)
126 {
127 	struct daemon_data *pri = data;
128 	struct timeval tv;
129 	struct {
130 		char zero;
131 		int pid;
132 		int usecs;
133 	} name;
134 
135 	if (!strcmp(pri->sock_type, "unix"))
136 		pri->ctl_addr = new_addr(pri->ctl_sock,
137 					 strlen(pri->ctl_sock) + 1);
138 	name.zero = 0;
139 	name.pid = os_getpid();
140 	gettimeofday(&tv, NULL);
141 	name.usecs = tv.tv_usec;
142 	pri->local_addr = new_addr(&name, sizeof(name));
143 	pri->dev = dev;
144 	pri->fd = connect_to_switch(pri);
145 	if (pri->fd < 0) {
146 		kfree(pri->local_addr);
147 		pri->local_addr = NULL;
148 		return pri->fd;
149 	}
150 
151 	return 0;
152 }
153 
154 static int daemon_open(void *data)
155 {
156 	struct daemon_data *pri = data;
157 	return pri->fd;
158 }
159 
160 static void daemon_remove(void *data)
161 {
162 	struct daemon_data *pri = data;
163 
164 	close(pri->fd);
165 	pri->fd = -1;
166 	close(pri->control);
167 	pri->control = -1;
168 
169 	kfree(pri->data_addr);
170 	pri->data_addr = NULL;
171 	kfree(pri->ctl_addr);
172 	pri->ctl_addr = NULL;
173 	kfree(pri->local_addr);
174 	pri->local_addr = NULL;
175 }
176 
177 int daemon_user_write(int fd, void *buf, int len, struct daemon_data *pri)
178 {
179 	struct sockaddr_un *data_addr = pri->data_addr;
180 
181 	return net_sendto(fd, buf, len, data_addr, sizeof(*data_addr));
182 }
183 
184 const struct net_user_info daemon_user_info = {
185 	.init		= daemon_user_init,
186 	.open		= daemon_open,
187 	.close	 	= NULL,
188 	.remove	 	= daemon_remove,
189 	.add_address	= NULL,
190 	.delete_address = NULL,
191 	.mtu		= ETH_MAX_PACKET,
192 	.max_packet	= ETH_MAX_PACKET + ETH_HEADER_OTHER,
193 };
194