compat/imsg.c - tmux - Rivoreo Source Code Repositories

 /*	$OpenBSD: imsg.c,v 1.6 2014/06/30 00:26:22 deraadt Exp $	*/

 /*
  * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
  *
  * Permission to use, copy, modify, and distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
  * copyright notice and this permission notice appear in all copies.
  *
  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */

 #include <sys/types.h>
 #include <sys/queue.h>
 #include <sys/socket.h>
 #include <sys/uio.h>

 #include <errno.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>

 #include "tmux.h"
 #include "imsg.h"

 int	 imsg_fd_overhead = 0;

 int	 imsg_get_fd(struct imsgbuf *);

 int	 available_fds(unsigned int);

 /* TA:  2014-09-08:  Note that the original code calls getdtablecount() which is
  * OpenBSD specific.  Until such time that it's ported elsewhere from
  * <unistd.h>, I've mimicked what OpenSMTPD are doing, by using available_fds()
  * instead.
  */

 int
 available_fds(unsigned int n)
 {
 	unsigned int	i;
 	int		ret, fds[256];

 	if (n > (sizeof(fds)/sizeof(fds[0])))
 		return (1);

 	ret = 0;
 	for (i = 0; i < n; i++) {
 		fds[i] = -1;
 		if ((fds[i] = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
 			ret = 1;
 			break;
 		}
 	}

 	for (i = 0; i < n && fds[i] >= 0; i++)
 		close(fds[i]);

 	return (ret);
 }

 void
 imsg_init(struct imsgbuf *ibuf, int fd)
 {
 	msgbuf_init(&ibuf->w);
 	bzero(&ibuf->r, sizeof(ibuf->r));
 	ibuf->fd = fd;
 	ibuf->w.fd = fd;
 	ibuf->pid = getpid();
 	TAILQ_INIT(&ibuf->fds);
 }

 ssize_t
 imsg_read(struct imsgbuf *ibuf)
 {
 	struct msghdr		 msg;
 	struct cmsghdr		*cmsg;
 	union {
 		struct cmsghdr hdr;
 		char	buf[CMSG_SPACE(sizeof(int) * 1)];
 	} cmsgbuf;
 	struct iovec		 iov;
 	ssize_t			 n = -1;
 	int			 fd;
 	struct imsg_fd		*ifd;

 	bzero(&msg, sizeof(msg));

 	iov.iov_base = ibuf->r.buf + ibuf->r.wpos;
 	iov.iov_len = sizeof(ibuf->r.buf) - ibuf->r.wpos;
 	msg.msg_iov = &iov;
 	msg.msg_iovlen = 1;
 	msg.msg_control = &cmsgbuf.buf;
 	msg.msg_controllen = sizeof(cmsgbuf.buf);

 	if ((ifd = calloc(1, sizeof(struct imsg_fd))) == NULL)
 		return (-1);

 again:
 	if (available_fds(imsg_fd_overhead +
 	    (CMSG_SPACE(sizeof(int))-CMSG_SPACE(0))/sizeof(int))) {
 		errno = EAGAIN;
 		free(ifd);
 		return (-1);
 	}

 	if ((n = recvmsg(ibuf->fd, &msg, 0)) == -1) {
 		if (errno == EMSGSIZE)
 			goto fail;
 		if (errno != EINTR && errno != EAGAIN)
 			goto fail;
 		goto again;
 	}

 	ibuf->r.wpos += n;

 	for (cmsg = CMSG_FIRSTHDR(&msg); cmsg != NULL;
 	    cmsg = CMSG_NXTHDR(&msg, cmsg)) {
 		if (cmsg->cmsg_level == SOL_SOCKET &&
 		    cmsg->cmsg_type == SCM_RIGHTS) {
 			int i;
 			int j;

 			/*
 			 * We only accept one file descriptor.  Due to C
 			 * padding rules, our control buffer might contain
 			 * more than one fd, and we must close them.
 			 */
 			j = ((char *)cmsg + cmsg->cmsg_len -
 			    (char *)CMSG_DATA(cmsg)) / sizeof(int);
 			for (i = 0; i < j; i++) {
 				fd = ((int *)CMSG_DATA(cmsg))[i];
 				if (ifd != NULL) {
 					ifd->fd = fd;
 					TAILQ_INSERT_TAIL(&ibuf->fds, ifd,
 					    entry);
 					ifd = NULL;
 				} else
 					close(fd);
 			}
 		}
 		/* we do not handle other ctl data level */
 	}

 fail:
 	if (ifd)
 		free(ifd);
 	return (n);
 }

 ssize_t
 imsg_get(struct imsgbuf *ibuf, struct imsg *imsg)
 {
 	size_t			 av, left, datalen;

 	av = ibuf->r.wpos;

 	if (IMSG_HEADER_SIZE > av)
 		return (0);

 	memcpy(&imsg->hdr, ibuf->r.buf, sizeof(imsg->hdr));
 	if (imsg->hdr.len < IMSG_HEADER_SIZE ||
 	    imsg->hdr.len > MAX_IMSGSIZE) {
 		errno = ERANGE;
 		return (-1);
 	}
 	if (imsg->hdr.len > av)
 		return (0);
 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
 	ibuf->r.rptr = ibuf->r.buf + IMSG_HEADER_SIZE;
 	if ((imsg->data = malloc(datalen)) == NULL)
 		return (-1);

 	if (imsg->hdr.flags & IMSGF_HASFD)
 		imsg->fd = imsg_get_fd(ibuf);
 	else
 		imsg->fd = -1;

 	memcpy(imsg->data, ibuf->r.rptr, datalen);

 	if (imsg->hdr.len < av) {
 		left = av - imsg->hdr.len;
 		memmove(&ibuf->r.buf, ibuf->r.buf + imsg->hdr.len, left);
 		ibuf->r.wpos = left;
 	} else
 		ibuf->r.wpos = 0;

 	return (datalen + IMSG_HEADER_SIZE);
 }

 int
 imsg_compose(struct imsgbuf *ibuf, u_int32_t type, u_int32_t peerid,
     pid_t pid, int fd, const void *data, u_int16_t datalen)
 {
 	struct ibuf	*wbuf;

 	if ((wbuf = imsg_create(ibuf, type, peerid, pid, datalen)) == NULL)
 		return (-1);

 	if (imsg_add(wbuf, data, datalen) == -1)
 		return (-1);

 	wbuf->fd = fd;

 	imsg_close(ibuf, wbuf);

 	return (1);
 }

 int
 imsg_composev(struct imsgbuf *ibuf, u_int32_t type, u_int32_t peerid,
     pid_t pid, int fd, const struct iovec *iov, int iovcnt)
 {
 	struct ibuf	*wbuf;
 	int		 i, datalen = 0;

 	for (i = 0; i < iovcnt; i++)
 		datalen += iov[i].iov_len;

 	if ((wbuf = imsg_create(ibuf, type, peerid, pid, datalen)) == NULL)
 		return (-1);

 	for (i = 0; i < iovcnt; i++)
 		if (imsg_add(wbuf, iov[i].iov_base, iov[i].iov_len) == -1)
 			return (-1);

 	wbuf->fd = fd;

 	imsg_close(ibuf, wbuf);

 	return (1);
 }

 /* ARGSUSED */
 struct ibuf *
 imsg_create(struct imsgbuf *ibuf, u_int32_t type, u_int32_t peerid,
     pid_t pid, u_int16_t datalen)
 {
 	struct ibuf	*wbuf;
 	struct imsg_hdr	 hdr;

 	datalen += IMSG_HEADER_SIZE;
 	if (datalen > MAX_IMSGSIZE) {
 		errno = ERANGE;
 		return (NULL);
 	}

 	hdr.type = type;
 	hdr.flags = 0;
 	hdr.peerid = peerid;
 	if ((hdr.pid = pid) == 0)
 		hdr.pid = ibuf->pid;
 	if ((wbuf = ibuf_dynamic(datalen, MAX_IMSGSIZE)) == NULL) {
 		return (NULL);
 	}
 	if (imsg_add(wbuf, &hdr, sizeof(hdr)) == -1)
 		return (NULL);

 	return (wbuf);
 }

 int
 imsg_add(struct ibuf *msg, const void *data, u_int16_t datalen)
 {
 	if (datalen)
 		if (ibuf_add(msg, data, datalen) == -1) {
 			ibuf_free(msg);
 			return (-1);
 		}
 	return (datalen);
 }

 void
 imsg_close(struct imsgbuf *ibuf, struct ibuf *msg)
 {
 	struct imsg_hdr	*hdr;

 	hdr = (struct imsg_hdr *)msg->buf;

 	hdr->flags &= ~IMSGF_HASFD;
 	if (msg->fd != -1)
 		hdr->flags |= IMSGF_HASFD;

 	hdr->len = (u_int16_t)msg->wpos;

 	ibuf_close(&ibuf->w, msg);
 }

 void
 imsg_free(struct imsg *imsg)
 {
 	free(imsg->data);
 }

 int
 imsg_get_fd(struct imsgbuf *ibuf)
 {
 	int		 fd;
 	struct imsg_fd	*ifd;

 	if ((ifd = TAILQ_FIRST(&ibuf->fds)) == NULL)
 		return (-1);

 	fd = ifd->fd;
 	TAILQ_REMOVE(&ibuf->fds, ifd, entry);
 	free(ifd);

 	return (fd);
 }

 int
 imsg_flush(struct imsgbuf *ibuf)
 {
 	while (ibuf->w.queued)
 		if (msgbuf_write(&ibuf->w) < 0)
 			return (-1);
 	return (0);
 }

 void
 imsg_clear(struct imsgbuf *ibuf)
 {
 	int	fd;

 	msgbuf_clear(&ibuf->w);
 	while ((fd = imsg_get_fd(ibuf)) != -1)
 		close(fd);
 }
	/* $OpenBSD: imsg.c,v 1.6 2014/06/30 00:26:22 deraadt Exp $ */

	/*
	* Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
	*
	* Permission to use, copy, modify, and distribute this software for any
	* purpose with or without fee is hereby granted, provided that the above
	* copyright notice and this permission notice appear in all copies.
	*
	* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
	* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
	* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
	* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
	* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
	* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
	* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
	*/

	#include <sys/types.h>
	#include <sys/queue.h>
	#include <sys/socket.h>
	#include <sys/uio.h>

	#include <errno.h>
	#include <stdlib.h>
	#include <string.h>
	#include <unistd.h>

	#include "tmux.h"
	#include "imsg.h"

	int imsg_fd_overhead = 0;

	int imsg_get_fd(struct imsgbuf *);

	int available_fds(unsigned int);

	/* TA: 2014-09-08: Note that the original code calls getdtablecount() which is
	* OpenBSD specific. Until such time that it's ported elsewhere from
	* <unistd.h>, I've mimicked what OpenSMTPD are doing, by using available_fds()
	* instead.
	*/

	int
	available_fds(unsigned int n)
	{
	unsigned int i;
	int ret, fds[256];

	if (n > (sizeof(fds)/sizeof(fds[0])))
	return (1);

	ret = 0;
	for (i = 0; i < n; i++) {
	fds[i] = -1;
	if ((fds[i] = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
	ret = 1;
	break;
	}
	}

	for (i = 0; i < n && fds[i] >= 0; i++)
	close(fds[i]);

	return (ret);
	}

	void
	imsg_init(struct imsgbuf *ibuf, int fd)
	{
	msgbuf_init(&ibuf->w);
	bzero(&ibuf->r, sizeof(ibuf->r));
	ibuf->fd = fd;
	ibuf->w.fd = fd;
	ibuf->pid = getpid();
	TAILQ_INIT(&ibuf->fds);
	}

	ssize_t
	imsg_read(struct imsgbuf *ibuf)
	{
	struct msghdr msg;
	struct cmsghdr *cmsg;
	union {
	struct cmsghdr hdr;
	char buf[CMSG_SPACE(sizeof(int) * 1)];
	} cmsgbuf;
	struct iovec iov;
	ssize_t n = -1;
	int fd;
	struct imsg_fd *ifd;

	bzero(&msg, sizeof(msg));

	iov.iov_base = ibuf->r.buf + ibuf->r.wpos;
	iov.iov_len = sizeof(ibuf->r.buf) - ibuf->r.wpos;
	msg.msg_iov = &iov;
	msg.msg_iovlen = 1;
	msg.msg_control = &cmsgbuf.buf;
	msg.msg_controllen = sizeof(cmsgbuf.buf);

	if ((ifd = calloc(1, sizeof(struct imsg_fd))) == NULL)
	return (-1);

	again:
	if (available_fds(imsg_fd_overhead +
	(CMSG_SPACE(sizeof(int))-CMSG_SPACE(0))/sizeof(int))) {
	errno = EAGAIN;
	free(ifd);
	return (-1);
	}

	if ((n = recvmsg(ibuf->fd, &msg, 0)) == -1) {
	if (errno == EMSGSIZE)
	goto fail;
	if (errno != EINTR && errno != EAGAIN)
	goto fail;
	goto again;
	}

	ibuf->r.wpos += n;

	for (cmsg = CMSG_FIRSTHDR(&msg); cmsg != NULL;
	cmsg = CMSG_NXTHDR(&msg, cmsg)) {
	if (cmsg->cmsg_level == SOL_SOCKET &&
	cmsg->cmsg_type == SCM_RIGHTS) {
	int i;
	int j;

	/*
	* We only accept one file descriptor. Due to C
	* padding rules, our control buffer might contain
	* more than one fd, and we must close them.
	*/
	j = ((char *)cmsg + cmsg->cmsg_len -
	(char *)CMSG_DATA(cmsg)) / sizeof(int);
	for (i = 0; i < j; i++) {
	fd = ((int *)CMSG_DATA(cmsg))[i];
	if (ifd != NULL) {
	ifd->fd = fd;
	TAILQ_INSERT_TAIL(&ibuf->fds, ifd,
	entry);
	ifd = NULL;
	} else
	close(fd);
	}
	}
	/* we do not handle other ctl data level */
	}

	fail:
	if (ifd)
	free(ifd);
	return (n);
	}

	ssize_t
	imsg_get(struct imsgbuf ibuf, struct imsg imsg)
	{
	size_t av, left, datalen;

	av = ibuf->r.wpos;

	if (IMSG_HEADER_SIZE > av)
	return (0);

	memcpy(&imsg->hdr, ibuf->r.buf, sizeof(imsg->hdr));
	if (imsg->hdr.len < IMSG_HEADER_SIZE \|\|
	imsg->hdr.len > MAX_IMSGSIZE) {
	errno = ERANGE;
	return (-1);
	}
	if (imsg->hdr.len > av)
	return (0);
	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
	ibuf->r.rptr = ibuf->r.buf + IMSG_HEADER_SIZE;
	if ((imsg->data = malloc(datalen)) == NULL)
	return (-1);

	if (imsg->hdr.flags & IMSGF_HASFD)
	imsg->fd = imsg_get_fd(ibuf);
	else
	imsg->fd = -1;

	memcpy(imsg->data, ibuf->r.rptr, datalen);

	if (imsg->hdr.len < av) {
	left = av - imsg->hdr.len;
	memmove(&ibuf->r.buf, ibuf->r.buf + imsg->hdr.len, left);
	ibuf->r.wpos = left;
	} else
	ibuf->r.wpos = 0;

	return (datalen + IMSG_HEADER_SIZE);
	}

	int
	imsg_compose(struct imsgbuf *ibuf, u_int32_t type, u_int32_t peerid,
	pid_t pid, int fd, const void *data, u_int16_t datalen)
	{
	struct ibuf *wbuf;

	if ((wbuf = imsg_create(ibuf, type, peerid, pid, datalen)) == NULL)
	return (-1);

	if (imsg_add(wbuf, data, datalen) == -1)
	return (-1);

	wbuf->fd = fd;

	imsg_close(ibuf, wbuf);

	return (1);
	}

	int
	imsg_composev(struct imsgbuf *ibuf, u_int32_t type, u_int32_t peerid,
	pid_t pid, int fd, const struct iovec *iov, int iovcnt)
	{
	struct ibuf *wbuf;
	int i, datalen = 0;

	for (i = 0; i < iovcnt; i++)
	datalen += iov[i].iov_len;

	if ((wbuf = imsg_create(ibuf, type, peerid, pid, datalen)) == NULL)
	return (-1);

	for (i = 0; i < iovcnt; i++)
	if (imsg_add(wbuf, iov[i].iov_base, iov[i].iov_len) == -1)
	return (-1);

	wbuf->fd = fd;

	imsg_close(ibuf, wbuf);

	return (1);
	}

	/* ARGSUSED */
	struct ibuf *
	imsg_create(struct imsgbuf *ibuf, u_int32_t type, u_int32_t peerid,
	pid_t pid, u_int16_t datalen)
	{
	struct ibuf *wbuf;
	struct imsg_hdr hdr;

	datalen += IMSG_HEADER_SIZE;
	if (datalen > MAX_IMSGSIZE) {
	errno = ERANGE;
	return (NULL);
	}

	hdr.type = type;
	hdr.flags = 0;
	hdr.peerid = peerid;
	if ((hdr.pid = pid) == 0)
	hdr.pid = ibuf->pid;
	if ((wbuf = ibuf_dynamic(datalen, MAX_IMSGSIZE)) == NULL) {
	return (NULL);
	}
	if (imsg_add(wbuf, &hdr, sizeof(hdr)) == -1)
	return (NULL);

	return (wbuf);
	}

	int
	imsg_add(struct ibuf msg, const void data, u_int16_t datalen)
	{
	if (datalen)
	if (ibuf_add(msg, data, datalen) == -1) {
	ibuf_free(msg);
	return (-1);
	}
	return (datalen);
	}

	void
	imsg_close(struct imsgbuf ibuf, struct ibuf msg)
	{
	struct imsg_hdr *hdr;

	hdr = (struct imsg_hdr *)msg->buf;

	hdr->flags &= ~IMSGF_HASFD;
	if (msg->fd != -1)
	hdr->flags \|= IMSGF_HASFD;

	hdr->len = (u_int16_t)msg->wpos;

	ibuf_close(&ibuf->w, msg);
	}

	void
	imsg_free(struct imsg *imsg)
	{
	free(imsg->data);
	}

	int
	imsg_get_fd(struct imsgbuf *ibuf)
	{
	int fd;
	struct imsg_fd *ifd;

	if ((ifd = TAILQ_FIRST(&ibuf->fds)) == NULL)
	return (-1);

	fd = ifd->fd;
	TAILQ_REMOVE(&ibuf->fds, ifd, entry);
	free(ifd);

	return (fd);
	}

	int
	imsg_flush(struct imsgbuf *ibuf)
	{
	while (ibuf->w.queued)
	if (msgbuf_write(&ibuf->w) < 0)
	return (-1);
	return (0);
	}

	void
	imsg_clear(struct imsgbuf *ibuf)
	{
	int fd;

	msgbuf_clear(&ibuf->w);
	while ((fd = imsg_get_fd(ibuf)) != -1)
	close(fd);
	}