xref: /openbmc/linux/arch/um/drivers/daemon_user.c (revision e15a5365)
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 <string.h>
11 #include <unistd.h>
12 #include <errno.h>
13 #include <sys/types.h>
14 #include <sys/socket.h>
15 #include <sys/time.h>
16 #include <sys/un.h>
17 #include "daemon.h"
18 #include <net_user.h>
19 #include <os.h>
20 #include <um_malloc.h>
21 
22 enum request_type { REQ_NEW_CONTROL };
23 
24 #define SWITCH_MAGIC 0xfeedface
25 
26 struct request_v3 {
27 	uint32_t magic;
28 	uint32_t version;
29 	enum request_type type;
30 	struct sockaddr_un sock;
31 };
32 
33 static struct sockaddr_un *new_addr(void *name, int len)
34 {
35 	struct sockaddr_un *sun;
36 
37 	sun = uml_kmalloc(sizeof(struct sockaddr_un), UM_GFP_KERNEL);
38 	if (sun == NULL) {
39 		printk(UM_KERN_ERR "new_addr: allocation of sockaddr_un "
40 		       "failed\n");
41 		return NULL;
42 	}
43 	sun->sun_family = AF_UNIX;
44 	memcpy(sun->sun_path, name, len);
45 	return sun;
46 }
47 
48 static int connect_to_switch(struct daemon_data *pri)
49 {
50 	struct sockaddr_un *ctl_addr = pri->ctl_addr;
51 	struct sockaddr_un *local_addr = pri->local_addr;
52 	struct sockaddr_un *sun;
53 	struct request_v3 req;
54 	int fd, n, err;
55 
56 	pri->control = socket(AF_UNIX, SOCK_STREAM, 0);
57 	if (pri->control < 0) {
58 		err = -errno;
59 		printk(UM_KERN_ERR "daemon_open : control socket failed, "
60 		       "errno = %d\n", -err);
61 		return err;
62 	}
63 
64 	if (connect(pri->control, (struct sockaddr *) ctl_addr,
65 		   sizeof(*ctl_addr)) < 0) {
66 		err = -errno;
67 		printk(UM_KERN_ERR "daemon_open : control connect failed, "
68 		       "errno = %d\n", -err);
69 		goto out;
70 	}
71 
72 	fd = socket(AF_UNIX, SOCK_DGRAM, 0);
73 	if (fd < 0) {
74 		err = -errno;
75 		printk(UM_KERN_ERR "daemon_open : data socket failed, "
76 		       "errno = %d\n", -err);
77 		goto out;
78 	}
79 	if (bind(fd, (struct sockaddr *) local_addr, sizeof(*local_addr)) < 0) {
80 		err = -errno;
81 		printk(UM_KERN_ERR "daemon_open : data bind failed, "
82 		       "errno = %d\n", -err);
83 		goto out_close;
84 	}
85 
86 	sun = uml_kmalloc(sizeof(struct sockaddr_un), UM_GFP_KERNEL);
87 	if (sun == NULL) {
88 		printk(UM_KERN_ERR "new_addr: allocation of sockaddr_un "
89 		       "failed\n");
90 		err = -ENOMEM;
91 		goto out_close;
92 	}
93 
94 	req.magic = SWITCH_MAGIC;
95 	req.version = SWITCH_VERSION;
96 	req.type = REQ_NEW_CONTROL;
97 	req.sock = *local_addr;
98 	n = write(pri->control, &req, sizeof(req));
99 	if (n != sizeof(req)) {
100 		printk(UM_KERN_ERR "daemon_open : control setup request "
101 		       "failed, err = %d\n", -errno);
102 		err = -ENOTCONN;
103 		goto out_free;
104 	}
105 
106 	n = read(pri->control, sun, sizeof(*sun));
107 	if (n != sizeof(*sun)) {
108 		printk(UM_KERN_ERR "daemon_open : read of data socket failed, "
109 		       "err = %d\n", -errno);
110 		err = -ENOTCONN;
111 		goto out_free;
112 	}
113 
114 	pri->data_addr = sun;
115 	return fd;
116 
117  out_free:
118 	kfree(sun);
119  out_close:
120 	close(fd);
121  out:
122 	close(pri->control);
123 	return err;
124 }
125 
126 static int daemon_user_init(void *data, void *dev)
127 {
128 	struct daemon_data *pri = data;
129 	struct timeval tv;
130 	struct {
131 		char zero;
132 		int pid;
133 		int usecs;
134 	} name;
135 
136 	if (!strcmp(pri->sock_type, "unix"))
137 		pri->ctl_addr = new_addr(pri->ctl_sock,
138 					 strlen(pri->ctl_sock) + 1);
139 	name.zero = 0;
140 	name.pid = os_getpid();
141 	gettimeofday(&tv, NULL);
142 	name.usecs = tv.tv_usec;
143 	pri->local_addr = new_addr(&name, sizeof(name));
144 	pri->dev = dev;
145 	pri->fd = connect_to_switch(pri);
146 	if (pri->fd < 0) {
147 		kfree(pri->local_addr);
148 		pri->local_addr = NULL;
149 		return pri->fd;
150 	}
151 
152 	return 0;
153 }
154 
155 static int daemon_open(void *data)
156 {
157 	struct daemon_data *pri = data;
158 	return pri->fd;
159 }
160 
161 static void daemon_remove(void *data)
162 {
163 	struct daemon_data *pri = data;
164 
165 	close(pri->fd);
166 	pri->fd = -1;
167 	close(pri->control);
168 	pri->control = -1;
169 
170 	kfree(pri->data_addr);
171 	pri->data_addr = NULL;
172 	kfree(pri->ctl_addr);
173 	pri->ctl_addr = NULL;
174 	kfree(pri->local_addr);
175 	pri->local_addr = NULL;
176 }
177 
178 int daemon_user_write(int fd, void *buf, int len, struct daemon_data *pri)
179 {
180 	struct sockaddr_un *data_addr = pri->data_addr;
181 
182 	return net_sendto(fd, buf, len, data_addr, sizeof(*data_addr));
183 }
184 
185 const struct net_user_info daemon_user_info = {
186 	.init		= daemon_user_init,
187 	.open		= daemon_open,
188 	.close	 	= NULL,
189 	.remove	 	= daemon_remove,
190 	.add_address	= NULL,
191 	.delete_address = NULL,
192 	.mtu		= ETH_MAX_PACKET,
193 	.max_packet	= ETH_MAX_PACKET + ETH_HEADER_OTHER,
194 };
195