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| | // SPDX-License-Identifier: GPL-2.0-or-later
// SPDX-FileCopyrightText: 2020-2021 Alyssa Ross <hi@alyssa.is>
#define _GNU_SOURCE
#include <errno.h>
#include <fcntl.h>
#include <inttypes.h>
#include <poll.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdnoreturn.h>
#include <string.h>
#include <sys/socket.h>
#include <sys/wait.h>
#include <sysexits.h>
#include <unistd.h>
#include <linux/vm_sockets.h>
#include "env.h"
#include "log.h"
#include "num.h"
#include "vsock.h"
noreturn static void ex_usage(void)
{
if (verbosity)
fprintf(stderr, "Usage: %s [ -1 ] [ -q | -Q | -v ] cid port prog...\n",
program_invocation_short_name);
exit(EX_USAGE);
}
int main(int argc, char *argv[])
{
bool notify = false;
int opt;
pid_t child;
uint32_t lcid, lport, rcid, rport;
while ((opt = getopt(argc, argv, "+1qQv")) != -1) {
switch (opt) {
case '1':
notify = true;
break;
case 'q':
case 'Q':
case 'v':
set_verbosity(opt);
break;
default:
ex_usage();
}
}
// Check there are enough positional arguments (two for the
// address and at least one to exec into).
if (optind > argc - 3)
ex_usage();
if (!strcmp(argv[optind], "-1"))
lcid = VMADDR_CID_ANY;
else if (getu32(argv[optind], 0, UINT32_MAX, &lcid))
ex_usage();
optind++;
if (!strcmp(argv[optind], "-1"))
lport = VMADDR_PORT_ANY;
else if (getu32(argv[optind], 0, UINT32_MAX, &lport))
ex_usage();
optind++;
int fd = socket(AF_VSOCK, SOCK_STREAM, 0);
if (fd == -1)
diee(EX_OSERR, "socket");
if (fcntl(fd, F_SETFL, O_NONBLOCK) == -1)
diee(EX_OSERR, "fcntl");
if (vsock_bind(fd, lcid, lport) == -1)
diee(EX_OSERR, "bind");
if (listen(fd, 40) == -1)
diee(EX_OSERR, "listen");
if (lport == VMADDR_PORT_ANY)
if (vsock_get_cid_and_port(fd, NULL, &lport) == -1)
diee(EX_OSERR, "getsockname");
if (notify) {
printf("%" PRIu32 "\n", lport);
fclose(stdout);
}
setenvf("VSOCKLOCALCID", 1, "%" PRIu32, lcid);
setenvf("VSOCKLOCALPORT", 1, "%" PRIu32, lport);
ilog("listening as %" PRIu32 " on port %" PRIu32, lcid, lport);
struct pollfd poll_fd = { .fd = fd, .events = POLL_IN, .revents = 0 };
while (poll(&poll_fd, 1, -1) != -1) {
// On Linux, conn will be blocking. On other
// platforms, this may not be the case. If other
// platforms are to be supported, we'd probably want
// to set O_NONBLOCK here.
int conn = vsock_accept(fd, &rcid, &rport);
if (conn == -1)
diee(EX_OSERR, "accept");
setenvf("VSOCKREMOTECID", 1, "%" PRIu32, rcid);
setenvf("VSOCKREMOTEPORT", 1, "%" PRIu32, rport);
ilog("connection from %" PRIu32 " port %" PRIu32, rcid, rport);
switch (child = fork()) {
case -1: diee(EX_OSERR, "fork");
case 0:
if (dup2(conn, STDIN_FILENO) == -1)
diee(EX_OSERR, "dup2");
if (dup2(conn, STDOUT_FILENO) == -1)
diee(EX_OSERR, "dup2");
if (conn != STDIN_FILENO && conn != STDOUT_FILENO)
close(conn);
execvp(argv[optind], &argv[optind]);
diee(EX_OSERR, "exec");
}
if (waitpid(child, NULL, 0) == -1)
diee(EX_OSERR, "waitpid");
close(conn);
}
diee(EX_OSERR, "poll");
}
|