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
22enum request_type { REQ_NEW_CONTROL };
23
24#define SWITCH_MAGIC 0xfeedface
25
26struct request_v3 {
27 uint32_t magic;
28 uint32_t version;
29 enum request_type type;
30 struct sockaddr_un sock;
31};
32
33static 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
48static 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
126static 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(name: pri->ctl_sock,
138 len: 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: &name, len: 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
155static int daemon_open(void *data)
156{
157 struct daemon_data *pri = data;
158 return pri->fd;
159}
160
161static 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
178int 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
185const 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

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