1323129Sdes/* $OpenBSD: monitor_fdpass.c,v 1.21 2016/02/29 20:22:36 jca Exp $ */ 298675Sdes/* 398675Sdes * Copyright 2001 Niels Provos <provos@citi.umich.edu> 498675Sdes * All rights reserved. 598675Sdes * 698675Sdes * Redistribution and use in source and binary forms, with or without 798675Sdes * modification, are permitted provided that the following conditions 898675Sdes * are met: 998675Sdes * 1. Redistributions of source code must retain the above copyright 1098675Sdes * notice, this list of conditions and the following disclaimer. 1198675Sdes * 2. Redistributions in binary form must reproduce the above copyright 1298675Sdes * notice, this list of conditions and the following disclaimer in the 1398675Sdes * documentation and/or other materials provided with the distribution. 1498675Sdes * 1598675Sdes * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 1698675Sdes * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 1798675Sdes * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 1898675Sdes * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 1998675Sdes * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 2098675Sdes * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 2198675Sdes * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 2298675Sdes * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 2398675Sdes * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 2498675Sdes * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 2598675Sdes */ 2698675Sdes 2798675Sdes#include "includes.h" 2898675Sdes 29162852Sdes#include <sys/types.h> 30162852Sdes#include <sys/socket.h> 3198675Sdes#include <sys/uio.h> 32164146Sdes#ifdef HAVE_SYS_UN_H 33164146Sdes#include <sys/un.h> 34164146Sdes#endif 3598675Sdes 36162852Sdes#include <errno.h> 37162852Sdes#include <string.h> 38162852Sdes#include <stdarg.h> 39162852Sdes 40294328Sdes#ifdef HAVE_POLL_H 41294328Sdes# include <poll.h> 42294328Sdes#else 43294328Sdes# ifdef HAVE_SYS_POLL_H 44294328Sdes# include <sys/poll.h> 45294328Sdes# endif 46294328Sdes#endif 47294328Sdes 4898675Sdes#include "log.h" 4998675Sdes#include "monitor_fdpass.h" 5098675Sdes 51181111Sdesint 52137015Sdesmm_send_fd(int sock, int fd) 5398675Sdes{ 5498937Sdes#if defined(HAVE_SENDMSG) && (defined(HAVE_ACCRIGHTS_IN_MSGHDR) || defined(HAVE_CONTROL_IN_MSGHDR)) 5598675Sdes struct msghdr msg; 5698937Sdes#ifndef HAVE_ACCRIGHTS_IN_MSGHDR 57180989Sdes union { 58180989Sdes struct cmsghdr hdr; 59180989Sdes char buf[CMSG_SPACE(sizeof(int))]; 60180989Sdes } cmsgbuf; 6198937Sdes struct cmsghdr *cmsg; 6298937Sdes#endif 63192595Sdes struct iovec vec; 64192595Sdes char ch = '\0'; 65192595Sdes ssize_t n; 66204917Sdes struct pollfd pfd; 6798675Sdes 6898675Sdes memset(&msg, 0, sizeof(msg)); 6998937Sdes#ifdef HAVE_ACCRIGHTS_IN_MSGHDR 7098937Sdes msg.msg_accrights = (caddr_t)&fd; 7198937Sdes msg.msg_accrightslen = sizeof(fd); 7298937Sdes#else 73294332Sdes memset(&cmsgbuf, 0, sizeof(cmsgbuf)); 74180989Sdes msg.msg_control = (caddr_t)&cmsgbuf.buf; 75180989Sdes msg.msg_controllen = sizeof(cmsgbuf.buf); 7698675Sdes cmsg = CMSG_FIRSTHDR(&msg); 7798675Sdes cmsg->cmsg_len = CMSG_LEN(sizeof(int)); 7898675Sdes cmsg->cmsg_level = SOL_SOCKET; 7998675Sdes cmsg->cmsg_type = SCM_RIGHTS; 8098675Sdes *(int *)CMSG_DATA(cmsg) = fd; 8198937Sdes#endif 8298675Sdes 8398675Sdes vec.iov_base = &ch; 8498675Sdes vec.iov_len = 1; 8598675Sdes msg.msg_iov = &vec; 8698675Sdes msg.msg_iovlen = 1; 8798675Sdes 88204917Sdes pfd.fd = sock; 89204917Sdes pfd.events = POLLOUT; 90204917Sdes while ((n = sendmsg(sock, &msg, 0)) == -1 && 91204917Sdes (errno == EAGAIN || errno == EINTR)) { 92192595Sdes debug3("%s: sendmsg(%d): %s", __func__, fd, strerror(errno)); 93204917Sdes (void)poll(&pfd, 1, -1); 94204917Sdes } 95192595Sdes if (n == -1) { 96181111Sdes error("%s: sendmsg(%d): %s", __func__, fd, 9798675Sdes strerror(errno)); 98181111Sdes return -1; 99181111Sdes } 100181111Sdes 101181111Sdes if (n != 1) { 102323129Sdes error("%s: sendmsg: expected sent 1 got %zd", __func__, n); 103181111Sdes return -1; 104181111Sdes } 105181111Sdes return 0; 10698937Sdes#else 107181111Sdes error("%s: file descriptor passing not supported", __func__); 108181111Sdes return -1; 10998937Sdes#endif 11098675Sdes} 11198675Sdes 11298675Sdesint 113137015Sdesmm_receive_fd(int sock) 11498675Sdes{ 11598937Sdes#if defined(HAVE_RECVMSG) && (defined(HAVE_ACCRIGHTS_IN_MSGHDR) || defined(HAVE_CONTROL_IN_MSGHDR)) 11698675Sdes struct msghdr msg; 11798937Sdes#ifndef HAVE_ACCRIGHTS_IN_MSGHDR 118180989Sdes union { 119180989Sdes struct cmsghdr hdr; 120180989Sdes char buf[CMSG_SPACE(sizeof(int))]; 121180989Sdes } cmsgbuf; 12298937Sdes struct cmsghdr *cmsg; 12398937Sdes#endif 124192595Sdes struct iovec vec; 125192595Sdes ssize_t n; 126192595Sdes char ch; 127192595Sdes int fd; 128204917Sdes struct pollfd pfd; 12998675Sdes 13098675Sdes memset(&msg, 0, sizeof(msg)); 13198675Sdes vec.iov_base = &ch; 13298675Sdes vec.iov_len = 1; 13398675Sdes msg.msg_iov = &vec; 13498675Sdes msg.msg_iovlen = 1; 13598937Sdes#ifdef HAVE_ACCRIGHTS_IN_MSGHDR 13698937Sdes msg.msg_accrights = (caddr_t)&fd; 13798937Sdes msg.msg_accrightslen = sizeof(fd); 13898937Sdes#else 139294332Sdes memset(&cmsgbuf, 0, sizeof(cmsgbuf)); 140180989Sdes msg.msg_control = &cmsgbuf.buf; 141180989Sdes msg.msg_controllen = sizeof(cmsgbuf.buf); 14298937Sdes#endif 14398675Sdes 144204917Sdes pfd.fd = sock; 145204917Sdes pfd.events = POLLIN; 146204917Sdes while ((n = recvmsg(sock, &msg, 0)) == -1 && 147204917Sdes (errno == EAGAIN || errno == EINTR)) { 148192595Sdes debug3("%s: recvmsg: %s", __func__, strerror(errno)); 149204917Sdes (void)poll(&pfd, 1, -1); 150204917Sdes } 151192595Sdes if (n == -1) { 152181111Sdes error("%s: recvmsg: %s", __func__, strerror(errno)); 153181111Sdes return -1; 154181111Sdes } 155192595Sdes 156181111Sdes if (n != 1) { 157323129Sdes error("%s: recvmsg: expected received 1 got %zd", __func__, n); 158181111Sdes return -1; 159181111Sdes } 16098675Sdes 16198937Sdes#ifdef HAVE_ACCRIGHTS_IN_MSGHDR 162181111Sdes if (msg.msg_accrightslen != sizeof(fd)) { 163181111Sdes error("%s: no fd", __func__); 164181111Sdes return -1; 165181111Sdes } 16698937Sdes#else 16798675Sdes cmsg = CMSG_FIRSTHDR(&msg); 168181111Sdes if (cmsg == NULL) { 169181111Sdes error("%s: no message header", __func__); 170181111Sdes return -1; 171181111Sdes } 172192595Sdes 173124208Sdes#ifndef BROKEN_CMSG_TYPE 174181111Sdes if (cmsg->cmsg_type != SCM_RIGHTS) { 175181111Sdes error("%s: expected type %d got %d", __func__, 17698675Sdes SCM_RIGHTS, cmsg->cmsg_type); 177181111Sdes return -1; 178181111Sdes } 179124208Sdes#endif 18098675Sdes fd = (*(int *)CMSG_DATA(cmsg)); 18198937Sdes#endif 18298675Sdes return fd; 18398937Sdes#else 184181111Sdes error("%s: file descriptor passing not supported", __func__); 185181111Sdes return -1; 18698937Sdes#endif 18798675Sdes} 188