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1/* $OpenBSD: command.c,v 1.18 2019/06/28 13:35:00 deraadt Exp $ */
2
3/*
4 * Copyright (c) 2012 Nicholas Marriott <nicm@openbsd.org>
5 *
6 * Permission to use, copy, modify, and distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
9 *
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
15 * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
16 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 */
18
19#include <sys/types.h>
20#include <sys/ioctl.h>
21#include <sys/wait.h>
22
23#include <event.h>
24#include <errno.h>
25#include <fcntl.h>
26#include <limits.h>
27#include <paths.h>
28#include <signal.h>
29#include <stdlib.h>
30#include <stdio.h>
31#include <string.h>
32#include <unistd.h>
33#include <vis.h>
34
35#include "cu.h"
36
37void pipe_command(void);
38void connect_command(void);
39void send_file(void);
40void send_xmodem(void);
41void set_speed(void);
42void start_record(void);
43
44void
45pipe_command(void)
46{
47 const char *cmd;
48 pid_t pid;
49 int fd;
50
51 cmd = get_input("Local command?");
52 if (cmd == NULL || *cmd == '\0')
53 return;
54
55 restore_termios();
56 set_blocking(line_fd, 1);
57
58 switch (pid = fork()) {
59 case -1:
60 cu_err(1, "fork");
61 case 0:
62 fd = open(_PATH_DEVNULL, O_RDWR);
63 if (fd == -1 || dup2(fd, STDIN_FILENO) == -1)
64 _exit(1);
65 close(fd);
66
67 if (signal(SIGINT, SIG_DFL) == SIG_ERR)
68 _exit(1);
69 if (signal(SIGQUIT, SIG_DFL) == SIG_ERR)
70 _exit(1);
71
72 /* attach stdout to line */
73 if (dup2(line_fd, STDOUT_FILENO) == -1)
74 _exit(1);
75
76 if (closefrom(STDERR_FILENO + 1) != 0)
77 _exit(1);
78
79 execl(_PATH_BSHELL, "sh", "-c", cmd, (char *)NULL);
80 _exit(1);
81 default:
82 while (waitpid(pid, NULL, 0) == -1 && errno == EINTR)
83 /* nothing */;
84 break;
85 }
86
87 set_blocking(line_fd, 0);
88 set_termios();
89}
90
91void
92connect_command(void)
93{
94 const char *cmd;
95 pid_t pid;
96
97 /*
98 * Fork a program with:
99 * 0 <-> remote tty in
100 * 1 <-> remote tty out
101 * 2 <-> local tty stderr
102 */
103
104 cmd = get_input("Local command?");
105 if (cmd == NULL || *cmd == '\0')
106 return;
107
108 restore_termios();
109 set_blocking(line_fd, 1);
110
111 switch (pid = fork()) {
112 case -1:
113 cu_err(1, "fork");
114 case 0:
115 if (signal(SIGINT, SIG_DFL) == SIG_ERR)
116 _exit(1);
117 if (signal(SIGQUIT, SIG_DFL) == SIG_ERR)
118 _exit(1);
119
120 /* attach stdout and stdin to line */
121 if (dup2(line_fd, STDOUT_FILENO) == -1)
122 _exit(1);
123 if (dup2(line_fd, STDIN_FILENO) == -1)
124 _exit(1);
125
126 if (closefrom(STDERR_FILENO + 1) != 0)
127 _exit(1);
128
129 execl(_PATH_BSHELL, "sh", "-c", cmd, (char *)NULL);
130 _exit(1);
131 default:
132 while (waitpid(pid, NULL, 0) == -1 && errno == EINTR)
133 /* nothing */;
134 break;
135 }
136
137 set_blocking(line_fd, 0);
138 set_termios();
139}
140
141void
142send_file(void)
143{
144 const char *file;
145 FILE *f;
146 char buf[BUFSIZ], *expanded;
147 size_t len;
148
149 file = get_input("Local file?");
150 if (file == NULL || *file == '\0')
151 return;
152
153 expanded = tilde_expand(file);
154 f = fopen(expanded, "r");
155 if (f == NULL) {
156 cu_warn("%s", file);
157 return;
158 }
159
160 while (!feof(f) && !ferror(f)) {
161 len = fread(buf, 1, sizeof(buf), f);
162 if (len != 0)
163 bufferevent_write(line_ev, buf, len);
164 }
165
166 fclose(f);
167 free(expanded);
168}
169
170void
171send_xmodem(void)
172{
173 const char *file;
174 char *expanded;
175
176 file = get_input("Local file?");
177 if (file == NULL || *file == '\0')
178 return;
179
180 expanded = tilde_expand(file);
181 xmodem_send(expanded);
182 free(expanded);
183}
184
185void
186set_speed(void)
187{
188 const char *s, *errstr;
189 int speed;
190
191 s = get_input("New speed?");
192 if (s == NULL || *s == '\0')
193 return;
194
195 speed = strtonum(s, 0, UINT_MAX, &errstr);
196 if (errstr != NULL) {
197 cu_warnx("speed is %s: %s", errstr, s);
198 return;
199 }
200
201 if (set_line(speed) != 0)
202 cu_warn("tcsetattr");
203}
204
205void
206start_record(void)
207{
208 const char *file;
209
210 if (record_file != NULL) {
211 fclose(record_file);
212 record_file = NULL;
213 }
214
215 file = get_input("Record file?");
216 if (file == NULL || *file == '\0')
217 return;
218
219 record_file = fopen(file, "a");
220 if (record_file == NULL)
221 cu_warnx("%s", file);
222}
223
224void
225do_command(char c)
226{
227 char esc[4 + 1];
228
229 if (restricted && strchr("CRX$>", c) != NULL) {
230 cu_warnx("~%c command is not allowed in restricted mode", c);
231 return;
232 }
233
234 switch (c) {
235 case '.':
236 case '\004': /* ^D */
237 event_loopexit(NULL);
238 break;
239 case '\032': /* ^Z */
240 restore_termios();
241 kill(getpid(), SIGTSTP);
242 set_termios();
243 break;
244 case 'C':
245 connect_command();
246 break;
247 case 'D':
248 ioctl(line_fd, TIOCCDTR, NULL);
249 sleep(1);
250 ioctl(line_fd, TIOCSDTR, NULL);
251 break;
252 case 'R':
253 start_record();
254 break;
255 case 'S':
256 set_speed();
257 break;
258 case 'X':
259 send_xmodem();
260 break;
261 case '$':
262 pipe_command();
263 break;
264 case '>':
265 send_file();
266 break;
267 case '#':
268 ioctl(line_fd, TIOCSBRK, NULL);
269 sleep(1);
270 ioctl(line_fd, TIOCCBRK, NULL);
271 break;
272 default:
273 if ((u_char)c == escape_char)
274 bufferevent_write(line_ev, &c, 1);
275 break;
276 case '?':
277 vis(esc, escape_char, VIS_WHITE | VIS_NOSLASH, 0);
278 printf("\r\n"
279 "%s# send break\r\n"
280 "%s$ pipe local command to remote host\r\n"
281 "%s> send file to remote host\r\n"
282 "%sC connect program to remote host\r\n"
283 "%sD de-assert DTR line briefly\r\n"
284 "%sR start recording to file\r\n"
285 "%sS set speed\r\n"
286 "%sX send file with XMODEM\r\n"
287 "%s? get this summary\r\n",
288 esc, esc, esc, esc, esc, esc, esc, esc, esc
289 );
290 break;
291 }
292}