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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 <err.h>
#include <errno.h>
#include <fcntl.h>
#include <poll.h>
#include <sys/ioctl.h>
#include <sys/ioctl.h>
#include <sysexits.h>
#include <unistd.h>
extern int winch(void);
static struct {
int winch;
int local;
int remote;
} fd = { -1, -1, STDIN_FILENO };
int main(int argc, char *argv[]) {
if (argc < 2) errx(EX_USAGE, "missing private id");
if (!isatty(STDERR_FILENO)) errx(EX_USAGE, "no terminal (use ssh -t)");
const char *path = argv[1];
fd.local = open(path, O_WRONLY);
if (fd.local < 0) err(EX_NOINPUT, "%s", path);
struct winsize window;
int error = ioctl(STDERR_FILENO, TIOCGWINSZ, &window);
if (error) err(EX_IOERR, "TIOCGWINSZ");
fd.winch = winch();
for (;;) {
int error = ftruncate(fd.local, 0);
if (error) err(EX_IOERR, "%s", path);
off_t off = lseek(fd.local, 0, SEEK_SET);
if (off < 0) err(EX_IOERR, "%s", path);
ssize_t size = write(fd.local, &window, sizeof(window));
if (size < 0) err(EX_IOERR, "write(%d)", fd.local);
if ((size_t)size < sizeof(window)) {
errx(EX_IOERR, "short write(%d)", fd.local);
}
char buf[4096];
struct pollfd fds[2] = {
{ .fd = fd.remote, .events = POLLIN },
{ .fd = fd.winch, .events = POLLIN },
};
for (ssize_t totalSize = 0; totalSize < 1024 * 1024;) {
int nfds = poll(fds, 2, -1);
if (nfds < 0) {
if (errno == EINTR) continue;
err(EX_IOERR, "poll");
}
if (fds[0].revents & POLLIN) {
ssize_t readSize = read(fd.remote, buf, sizeof(buf));
if (readSize < 0) err(EX_IOERR, "read(%d)", fd.remote);
if (!readSize) return EX_OK;
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);
totalSize += readSize;
}
if (fds[0].revents & POLLHUP) return EX_OK;
if (fds[1].revents & POLLIN) {
ssize_t readSize = read(fd.winch, &window, sizeof(window));
if (readSize < 0) err(EX_IOERR, "read(%d)", fd.winch);
if ((size_t)readSize < sizeof(window)) {
errx(EX_IOERR, "short read(%d)", fd.winch);
}
break;
}
}
}
}
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