From 2325ad59676d9311bacd0323f7eefc32ced07c40 Mon Sep 17 00:00:00 2001 From: eric Date: Wed, 31 Mar 2021 17:42:24 +0000 Subject: change the barrier so that fd's are always passed and received with the first byte of the imsg they belong to. idea, tweaks and ok claudio@ --- lib/libutil/imsg-buffer.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) (limited to 'lib/libutil/imsg-buffer.c') diff --git a/lib/libutil/imsg-buffer.c b/lib/libutil/imsg-buffer.c index 7c60d9e9e72..4526842bd86 100644 --- a/lib/libutil/imsg-buffer.c +++ b/lib/libutil/imsg-buffer.c @@ -1,4 +1,4 @@ -/* $OpenBSD: imsg-buffer.c,v 1.12 2019/01/20 02:50:03 bcook Exp $ */ +/* $OpenBSD: imsg-buffer.c,v 1.13 2021/03/31 17:42:24 eric Exp $ */ /* * Copyright (c) 2003, 2004 Henning Brauer @@ -225,7 +225,7 @@ int msgbuf_write(struct msgbuf *msgbuf) { struct iovec iov[IOV_MAX]; - struct ibuf *buf; + struct ibuf *buf, *buf0 = NULL; unsigned int i = 0; ssize_t n; struct msghdr msg; @@ -241,24 +241,26 @@ msgbuf_write(struct msgbuf *msgbuf) TAILQ_FOREACH(buf, &msgbuf->bufs, entry) { if (i >= IOV_MAX) break; + if (i > 0 && buf->fd != -1) + break; iov[i].iov_base = buf->buf + buf->rpos; iov[i].iov_len = buf->wpos - buf->rpos; i++; if (buf->fd != -1) - break; + buf0 = buf; } msg.msg_iov = iov; msg.msg_iovlen = i; - if (buf != NULL && buf->fd != -1) { + if (buf0 != NULL) { 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) = buf->fd; + *(int *)CMSG_DATA(cmsg) = buf0->fd; } again: @@ -279,9 +281,9 @@ again: * assumption: fd got sent if sendmsg sent anything * this works because fds are passed one at a time */ - if (buf != NULL && buf->fd != -1) { - close(buf->fd); - buf->fd = -1; + if (buf0 != NULL) { + close(buf0->fd); + buf0->fd = -1; } msgbuf_drain(msgbuf, n); -- cgit v1.2.3-59-g8ed1b