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/* Copyright (C) 2018 Causal Agent June <june@causal.agency>
*
* 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 <sys/types.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <stdlib.h>
#include <sys/event.h>
#include <sys/ioctl.h>
#include <sysexits.h>
#include <termios.h>
#include <unistd.h>
extern int winch(void);
static struct {
int winch;
int remote;
int local;
int input;
} fd = { -1, -1, STDOUT_FILENO, STDIN_FILENO };
static struct termios saveTerm;
static void restoreTerm(void) {
tcsetattr(fd.input, TCSADRAIN, &saveTerm);
}
int main(int argc, char *argv[]) {
int error;
if (argc < 2) errx(EX_USAGE, "missing public id");
if (!isatty(fd.local)) errx(EX_USAGE, "no terminal (use ssh -t)");
const char *path = argv[1];
fd.remote = open(path, O_RDONLY);
if (fd.remote < 0) err(EX_NOINPUT, "%s", path);
error = tcgetattr(fd.input, &saveTerm);
if (error) err(EX_IOERR, "tcgetattr");
atexit(restoreTerm);
struct termios term = saveTerm;
term.c_lflag &= ~(ICANON | ECHO);
error = tcsetattr(fd.input, TCSADRAIN, &term);
if (error) err(EX_IOERR, "tcsetattr");
struct winsize localWindow;
error = ioctl(fd.local, TIOCGWINSZ, &localWindow);
if (error) err(EX_IOERR, "TIOCGWINSZ");
fd.winch = winch();
int kq = kqueue();
if (kq < 0) err(EX_OSERR, "kqueue");
struct kevent events[3] = {
{ .ident = fd.input, .filter = EVFILT_READ, .flags = EV_ADD },
{ .ident = fd.remote, .filter = EVFILT_READ, .flags = EV_ADD },
{ .ident = fd.winch, .filter = EVFILT_READ, .flags = EV_ADD },
};
int nevents = kevent(kq, events, 3, NULL, 0, NULL);
if (nevents < 0) err(EX_OSERR, "kevent");
for (;;) {
off_t off = lseek(fd.remote, 0, SEEK_SET);
if (off < 0) err(EX_IOERR, "%s", path);
// FIXME: Hack spin waiting for remote window.
struct winsize remoteWindow;
ssize_t size;
for (int i = 0; i < 100; ++i, usleep(100)) {
size = read(fd.remote, &remoteWindow, sizeof(remoteWindow));
if (size < 0) err(EX_IOERR, "read(%d)", fd.remote);
if (size) break;
}
if ((size_t)size < sizeof(remoteWindow)) {
errx(EX_DATAERR, "no window size (stream not started)");
}
if (
localWindow.ws_col < remoteWindow.ws_col
|| localWindow.ws_row < remoteWindow.ws_row
) {
warnx(
"resize window %hux%hu to at least %hux%hu",
localWindow.ws_col, localWindow.ws_row,
remoteWindow.ws_col, remoteWindow.ws_row
);
ssize_t size = read(fd.winch, &localWindow, sizeof(localWindow));
if (size < 0) err(EX_IOERR, "read(%d)", fd.winch);
if ((size_t)size < sizeof(localWindow)) {
errx(EX_IOERR, "short read(%d)", fd.winch);
}
continue;
}
char buf[4096];
for (;;) {
struct kevent event;
int nevents = kevent(kq, NULL, 0, &event, 1, NULL);
if (nevents < 0) {
if (errno == EINTR) continue;
err(EX_OSERR, "kevent");
}
if (!nevents) continue;
if (event.ident == (uintptr_t)fd.input) {
ssize_t size = read(fd.input, buf, sizeof(buf));
if (size < 0) err(EX_IOERR, "read(%d)", fd.input);
if (size == 1 && buf[0] == 'q') return EX_OK;
}
if (event.ident == (uintptr_t)fd.remote) {
if (event.data < 0) break;
ssize_t readSize = read(fd.remote, buf, sizeof(buf));
if (readSize < 0) err(EX_IOERR, "read(%d)", fd.remote);
ssize_t writeSize = write(fd.local, buf, readSize);
if (writeSize < 0) err(EX_IOERR, "write(%d)", fd.local);
if (writeSize < readSize) errx(EX_IOERR, "short write(%d)", fd.local);
}
if (event.ident == (uintptr_t)fd.winch) {
ssize_t size = read(fd.winch, &localWindow, sizeof(localWindow));
if (size < 0) err(EX_IOERR, "read(%d)", fd.winch);
if ((size_t)size < sizeof(localWindow)) {
errx(EX_IOERR, "short read(%d)", fd.winch);
}
break;
}
}
}
}
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