/* $NetBSD: monitor_fdpass.c,v 1.8.14.1 2023/12/25 12:31:05 martin Exp $ */ /* $OpenBSD: monitor_fdpass.c,v 1.22 2020/10/18 11:32:01 djm Exp $ */ /* * Copyright 2001 Niels Provos * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #include "includes.h" __RCSID("$NetBSD: monitor_fdpass.c,v 1.8.14.1 2023/12/25 12:31:05 martin Exp $"); #include #include #include #include #include #include #include #include "log.h" #include "monitor_fdpass.h" int mm_send_fd(int sock, int fd) { struct msghdr msg; union { struct cmsghdr hdr; char buf[1024]; } cmsgbuf; struct cmsghdr *cmsg; struct iovec vec; char ch = '\0'; ssize_t n; struct pollfd pfd; if (sizeof(cmsgbuf.buf) < CMSG_SPACE(sizeof(int))) { error("%s: %zu < %zu, recompile", __func__, sizeof(cmsgbuf.buf), CMSG_SPACE(sizeof(int))); return -1; } memset(&msg, 0, sizeof(msg)); memset(&cmsgbuf, 0, sizeof(cmsgbuf)); msg.msg_control = &cmsgbuf.buf; msg.msg_controllen = CMSG_SPACE(sizeof(int)); cmsg = CMSG_FIRSTHDR(&msg); cmsg->cmsg_len = CMSG_LEN(sizeof(int)); cmsg->cmsg_level = SOL_SOCKET; cmsg->cmsg_type = SCM_RIGHTS; *(int *)CMSG_DATA(cmsg) = fd; msg.msg_controllen = cmsg->cmsg_len; vec.iov_base = &ch; vec.iov_len = 1; msg.msg_iov = &vec; msg.msg_iovlen = 1; pfd.fd = sock; pfd.events = POLLOUT; while ((n = sendmsg(sock, &msg, 0)) == -1 && (errno == EAGAIN || errno == EINTR)) { debug3_f("sendmsg(%d): %s", fd, strerror(errno)); (void)poll(&pfd, 1, -1); } if (n == -1) { error_f("sendmsg(%d): %s", fd, strerror(errno)); return -1; } if (n != 1) { error_f("sendmsg: expected sent 1 got %zd", n); return -1; } return 0; } int mm_receive_fd(int sock) { struct msghdr msg; union { struct cmsghdr hdr; char buf[1024]; } cmsgbuf; struct cmsghdr *cmsg; struct iovec vec; ssize_t n; char ch; int fd; struct pollfd pfd; if (sizeof(cmsgbuf.buf) < CMSG_SPACE(sizeof(int))) { error("%s: %zu < %zu, recompile", __func__, sizeof(cmsgbuf.buf), CMSG_SPACE(sizeof(int))); return -1; } memset(&msg, 0, sizeof(msg)); memset(&cmsgbuf, 0, sizeof(cmsgbuf)); vec.iov_base = &ch; vec.iov_len = 1; msg.msg_iov = &vec; msg.msg_iovlen = 1; msg.msg_control = &cmsgbuf.buf; msg.msg_controllen = CMSG_SPACE(sizeof(int)); pfd.fd = sock; pfd.events = POLLIN; while ((n = recvmsg(sock, &msg, 0)) == -1 && (errno == EAGAIN || errno == EINTR)) { debug3_f("recvmsg: %s", strerror(errno)); (void)poll(&pfd, 1, -1); } if (n == -1) { error_f("recvmsg: %s", strerror(errno)); return -1; } if (n != 1) { error_f("recvmsg: expected received 1 got %zd", n); return -1; } cmsg = CMSG_FIRSTHDR(&msg); if (cmsg == NULL) { error_f("no message header"); return -1; } if (cmsg->cmsg_type != SCM_RIGHTS) { error_f("expected %d got %d", SCM_RIGHTS, cmsg->cmsg_type); return -1; } fd = (*(int *)CMSG_DATA(cmsg)); return fd; }