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Diffstat (limited to '')
| -rw-r--r-- | monitor_fdpass.c | 185 |
1 files changed, 185 insertions, 0 deletions
diff --git a/monitor_fdpass.c b/monitor_fdpass.c new file mode 100644 index 0000000..a07727a --- /dev/null +++ b/monitor_fdpass.c @@ -0,0 +1,185 @@ +/* $OpenBSD: monitor_fdpass.c,v 1.22 2020/10/18 11:32:01 djm Exp $ */ +/* + * Copyright 2001 Niels Provos <provos@citi.umich.edu> + * 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" + +#include <sys/types.h> +#include <sys/socket.h> +#include <sys/uio.h> +#ifdef HAVE_SYS_UN_H +#include <sys/un.h> +#endif + +#include <errno.h> +#include <string.h> +#include <stdarg.h> + +#ifdef HAVE_POLL_H +# include <poll.h> +#else +# ifdef HAVE_SYS_POLL_H +# include <sys/poll.h> +# endif +#endif + +#include "log.h" +#include "monitor_fdpass.h" + +int +mm_send_fd(int sock, int fd) +{ +#if defined(HAVE_SENDMSG) && (defined(HAVE_ACCRIGHTS_IN_MSGHDR) || defined(HAVE_CONTROL_IN_MSGHDR)) + struct msghdr msg; +#ifndef HAVE_ACCRIGHTS_IN_MSGHDR + union { + struct cmsghdr hdr; + char buf[CMSG_SPACE(sizeof(int))]; + } cmsgbuf; + struct cmsghdr *cmsg; +#endif + struct iovec vec; + char ch = '\0'; + ssize_t n; + struct pollfd pfd; + + memset(&msg, 0, sizeof(msg)); +#ifdef HAVE_ACCRIGHTS_IN_MSGHDR + msg.msg_accrights = (caddr_t)&fd; + msg.msg_accrightslen = sizeof(fd); +#else + memset(&cmsgbuf, 0, sizeof(cmsgbuf)); + msg.msg_control = (caddr_t)&cmsgbuf.buf; + msg.msg_controllen = sizeof(cmsgbuf.buf); + 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; +#endif + + 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; +#else + error("%s: file descriptor passing not supported", __func__); + return -1; +#endif +} + +int +mm_receive_fd(int sock) +{ +#if defined(HAVE_RECVMSG) && (defined(HAVE_ACCRIGHTS_IN_MSGHDR) || defined(HAVE_CONTROL_IN_MSGHDR)) + struct msghdr msg; +#ifndef HAVE_ACCRIGHTS_IN_MSGHDR + union { + struct cmsghdr hdr; + char buf[CMSG_SPACE(sizeof(int))]; + } cmsgbuf; + struct cmsghdr *cmsg; +#endif + struct iovec vec; + ssize_t n; + char ch; + int fd; + struct pollfd pfd; + + memset(&msg, 0, sizeof(msg)); + vec.iov_base = &ch; + vec.iov_len = 1; + msg.msg_iov = &vec; + msg.msg_iovlen = 1; +#ifdef HAVE_ACCRIGHTS_IN_MSGHDR + msg.msg_accrights = (caddr_t)&fd; + msg.msg_accrightslen = sizeof(fd); +#else + memset(&cmsgbuf, 0, sizeof(cmsgbuf)); + msg.msg_control = &cmsgbuf.buf; + msg.msg_controllen = sizeof(cmsgbuf.buf); +#endif + + 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; + } + +#ifdef HAVE_ACCRIGHTS_IN_MSGHDR + if (msg.msg_accrightslen != sizeof(fd)) { + error_f("no fd"); + return -1; + } +#else + cmsg = CMSG_FIRSTHDR(&msg); + if (cmsg == NULL) { + error_f("no message header"); + return -1; + } + +#ifndef BROKEN_CMSG_TYPE + if (cmsg->cmsg_type != SCM_RIGHTS) { + error_f("expected %d got %d", SCM_RIGHTS, cmsg->cmsg_type); + return -1; + } +#endif + fd = (*(int *)CMSG_DATA(cmsg)); +#endif + return fd; +#else + error_f("file descriptor passing not supported"); + return -1; +#endif +} |