1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
|
/* Copyright (c) 2018, Curtis McEnroe <programble@gmail.com>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <err.h>
#include <poll.h>
#include <pwd.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/ioctl.h>
#include <sys/wait.h>
#include <sysexits.h>
#include <termios.h>
#include <unistd.h>
#if defined __FreeBSD__
#include <libutil.h>
#elif defined __linux__
#include <pty.h>
#else
#include <util.h>
#endif
#include "stream.h"
static struct termios saveTerm;
static void restoreTerm(void) {
tcsetattr(STDERR_FILENO, TCSADRAIN, &saveTerm);
}
int main(int argc, char *argv[]) {
int error;
if (argc > 1) {
argv++;
} else {
uid_t uid = getuid();
struct passwd *user = getpwuid(uid);
if (!user) err(EX_OSFILE, "/etc/passwd");
argv[0] = user->pw_shell;
}
int input = STDIN_FILENO;
int local = STDERR_FILENO;
int remote = STDOUT_FILENO;
if (isatty(remote)) {
errx(EX_USAGE, "stdout is not redirected");
}
error = tcgetattr(local, &saveTerm);
if (error) err(EX_IOERR, "tcgetattr");
atexit(restoreTerm);
struct termios raw;
cfmakeraw(&raw);
error = tcsetattr(local, TCSADRAIN, &raw);
if (error) err(EX_IOERR, "tcsetattr");
struct winsize window;
error = ioctl(local, TIOCGWINSZ, &window);
if (error) err(EX_IOERR, "ioctl(%d, TIOCGWINSZ, ...)", local);
ssize_t size = write(remote, &window, sizeof(window));
if (size < 0) err(EX_IOERR, "write(%d)", remote);
if ((size_t)size < sizeof(window)) errx(EX_IOERR, "short write(%d)", remote);
int pty;
pid_t pid = forkpty(&pty, NULL, NULL, &window);
if (pid < 0) err(EX_OSERR, "forkpty");
if (!pid) {
execvp(*argv, argv);
err(EX_USAGE, "%s", *argv);
}
char buf[4096];
ssize_t totalSize = 0;
struct pollfd fds[2] = {
{ .fd = input, .events = POLLIN },
{ .fd = pty, .events = POLLIN },
};
while (0 < poll(fds, 2, -1)) {
if (fds[0].revents) {
ssize_t readSize = read(input, buf, sizeof(buf));
if (readSize < 0) err(EX_IOERR, "read(%d)", input);
ssize_t writeSize = write(pty, buf, readSize);
if (writeSize < 0) err(EX_IOERR, "write(%d)", pty);
if (writeSize < readSize) errx(EX_IOERR, "short write(%d)", pty);
}
if (fds[1].revents) {
ssize_t readSize = read(pty, buf, sizeof(buf));
if (readSize < 0) err(EX_IOERR, "read(%d)", pty);
ssize_t writeSize = write(local, buf, readSize);
if (writeSize < 0) err(EX_IOERR, "write(%d)", local);
if (writeSize < readSize) errx(EX_IOERR, "short write(%d)", local);
writeSize = write(remote, buf, readSize);
if (writeSize < 0) err(EX_IOERR, "write(%d)", remote);
if (writeSize < readSize) errx(EX_IOERR, "short write(%d)", remote);
totalSize += readSize;
if (totalSize >= STREAM_SIZE) {
buf[0] = CTRL('L');
writeSize = write(pty, buf, 1);
if (writeSize < 0) err(EX_IOERR, "write(%d)", pty);
totalSize = 0;
}
}
int status;
pid_t dead = waitpid(pid, &status, WNOHANG);
if (dead < 0) err(EX_OSERR, "waitpid");
if (dead) return WIFEXITED(status) ? WEXITSTATUS(status) : EX_SOFTWARE;
}
err(EX_IOERR, "poll");
}
|