1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{linux.intel,addtoit}.com)
4 */
5
6#include <stdio.h>
7#include <stdlib.h>
8#include <string.h>
9#include <errno.h>
10#include <termios.h>
11#include <unistd.h>
12#include <netinet/in.h>
13#include "chan_user.h"
14#include <os.h>
15#include "port.h"
16#include <um_malloc.h>
17
18struct port_chan {
19 int raw;
20 struct termios tt;
21 void *kernel_data;
22 char dev[sizeof("32768\0")];
23};
24
25static void *port_init(char *str, int device, const struct chan_opts *opts)
26{
27 struct port_chan *data;
28 void *kern_data;
29 char *end;
30 int port;
31
32 if (*str != ':') {
33 printk(UM_KERN_ERR "port_init : channel type 'port' must "
34 "specify a port number\n");
35 return NULL;
36 }
37 str++;
38 port = strtoul(str, &end, 0);
39 if ((*end != '\0') || (end == str)) {
40 printk(UM_KERN_ERR "port_init : couldn't parse port '%s'\n",
41 str);
42 return NULL;
43 }
44
45 kern_data = port_data(port);
46 if (kern_data == NULL)
47 return NULL;
48
49 data = uml_kmalloc(sizeof(*data), UM_GFP_KERNEL);
50 if (data == NULL)
51 goto err;
52
53 *data = ((struct port_chan) { .raw = opts->raw,
54 .kernel_data = kern_data });
55 sprintf(data->dev, "%d", port);
56
57 return data;
58 err:
59 port_kern_free(d: kern_data);
60 return NULL;
61}
62
63static void port_free(void *d)
64{
65 struct port_chan *data = d;
66
67 port_kern_free(d: data->kernel_data);
68 kfree(data);
69}
70
71static int port_open(int input, int output, int primary, void *d,
72 char **dev_out)
73{
74 struct port_chan *data = d;
75 int fd, err;
76
77 fd = port_wait(data: data->kernel_data);
78 if ((fd >= 0) && data->raw) {
79 CATCH_EINTR(err = tcgetattr(fd, &data->tt));
80 if (err)
81 return err;
82
83 err = raw(fd);
84 if (err)
85 return err;
86 }
87 *dev_out = data->dev;
88 return fd;
89}
90
91static void port_close(int fd, void *d)
92{
93 struct port_chan *data = d;
94
95 port_remove_dev(d: data->kernel_data);
96 os_close_file(fd);
97}
98
99const struct chan_ops port_ops = {
100 .type = "port",
101 .init = port_init,
102 .open = port_open,
103 .close = port_close,
104 .read = generic_read,
105 .write = generic_write,
106 .console_write = generic_console_write,
107 .window_size = generic_window_size,
108 .free = port_free,
109 .winch = 1,
110};
111
112int port_listen_fd(int port)
113{
114 struct sockaddr_in addr;
115 int fd, err, arg;
116
117 fd = socket(PF_INET, SOCK_STREAM, 0);
118 if (fd == -1)
119 return -errno;
120
121 arg = 1;
122 if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &arg, sizeof(arg)) < 0) {
123 err = -errno;
124 goto out;
125 }
126
127 addr.sin_family = AF_INET;
128 addr.sin_port = htons(port);
129 addr.sin_addr.s_addr = htonl(INADDR_ANY);
130 if (bind(fd, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
131 err = -errno;
132 goto out;
133 }
134
135 if (listen(fd, 1) < 0) {
136 err = -errno;
137 goto out;
138 }
139
140 err = os_set_fd_block(fd, 0);
141 if (err < 0)
142 goto out;
143
144 return fd;
145 out:
146 close(fd);
147 return err;
148}
149
150struct port_pre_exec_data {
151 int sock_fd;
152 int pipe_fd;
153};
154
155static void port_pre_exec(void *arg)
156{
157 struct port_pre_exec_data *data = arg;
158
159 dup2(data->sock_fd, 0);
160 dup2(data->sock_fd, 1);
161 dup2(data->sock_fd, 2);
162 close(data->sock_fd);
163 dup2(data->pipe_fd, 3);
164 shutdown(3, SHUT_RD);
165 close(data->pipe_fd);
166}
167
168int port_connection(int fd, int *socket, int *pid_out)
169{
170 int new, err;
171 char *env;
172 char *argv[] = { "in.telnetd", "-L",
173 OS_LIB_PATH "/uml/port-helper", NULL };
174 struct port_pre_exec_data data;
175
176 if ((env = getenv("UML_PORT_HELPER")))
177 argv[2] = env;
178
179 new = accept(fd, NULL, 0);
180 if (new < 0)
181 return -errno;
182
183 err = os_access(argv[2], X_OK);
184 if (err < 0) {
185 printk(UM_KERN_ERR "port_connection : error accessing port-helper "
186 "executable at %s: %s\n", argv[2], strerror(-err));
187 if (env == NULL)
188 printk(UM_KERN_ERR "Set UML_PORT_HELPER environment "
189 "variable to path to uml-utilities port-helper "
190 "binary\n");
191 goto out_close;
192 }
193
194 err = os_pipe(socket, 0, 0);
195 if (err < 0)
196 goto out_close;
197
198 data = ((struct port_pre_exec_data)
199 { .sock_fd = new,
200 .pipe_fd = socket[1] });
201
202 err = run_helper(port_pre_exec, &data, argv);
203 if (err < 0)
204 goto out_shutdown;
205
206 *pid_out = err;
207 return new;
208
209 out_shutdown:
210 shutdown(socket[0], SHUT_RDWR);
211 close(socket[0]);
212 shutdown(socket[1], SHUT_RDWR);
213 close(socket[1]);
214 out_close:
215 close(new);
216 return err;
217}
218

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