[mirror_frr.git] / lib / imsg.c

/*	$OpenBSD$	*/

/*
 * 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 <zebra.h>

#include "memory.h"
#include "queue.h"
#include "imsg.h"

static int imsg_fd_overhead = 0;

static int imsg_get_fd(struct imsgbuf *);

#ifndef __OpenBSD__
/*
 * The original code calls getdtablecount() which is OpenBSD specific. Use
 * available_fds() from OpenSMTPD instead.
 */
static int available_fds(unsigned int n)
{
	unsigned int i;
	int ret, fds[256];

	if (n > (unsigned int)array_size(fds))
		return (1);

	ret = 0;
	for (i = 0; i < n; i++) {
		fds[i] = -1;
		if ((fds[i] = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
			if (errno == EAFNOSUPPORT || errno == EPROTONOSUPPORT)
				fds[i] = socket(AF_INET6, SOCK_DGRAM, 0);
			if (fds[i] < 0) {
				ret = 1;
				break;
			}
		}
	}

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

	return (ret);
}
#endif

void imsg_init(struct imsgbuf *ibuf, int fd)
{
	msgbuf_init(&ibuf->w);
	memset(&ibuf->r, 0, 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;
	int fd;
	struct imsg_fd *ifd;

	memset(&msg, 0, sizeof(msg));
	memset(&cmsgbuf, 0, sizeof(cmsgbuf));

	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:
#ifdef __OpenBSD__
	if (getdtablecount() + imsg_fd_overhead
		    + (int)((CMSG_SPACE(sizeof(int)) - CMSG_SPACE(0))
			    / sizeof(int))
	    >= getdtablesize()) {
#else
	if (available_fds(imsg_fd_overhead
			  + (CMSG_SPACE(sizeof(int)) - CMSG_SPACE(0))
				    / sizeof(int))) {
#endif
		errno = EAGAIN;
		free(ifd);
		return (-1);
	}

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

	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:
	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 (datalen == 0)
		imsg->data = NULL;
	else if ((imsg->data = malloc(datalen)) == NULL)
		return (-1);

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

	if (imsg->data)
		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, uint32_t type, uint32_t peerid,
		 pid_t pid, int fd, const void *data, uint16_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, uint32_t type, uint32_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, uint32_t type, uint32_t peerid,
			 pid_t pid, uint16_t datalen)
{
	struct ibuf *wbuf;
	struct imsg_hdr hdr;

	memset(&hdr, 0x00, IMSG_HEADER_SIZE);

	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, uint16_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 = (uint16_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_POP_FIRST(&ibuf->fds, entry)) == NULL)
		return (-1);

	fd = ifd->fd;
	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);
}
Commit	Line	Data
8429abe0 RW	1	/* $OpenBSD$ */
	2
	3	/*
	4	* Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
	5	*
	6	* Permission to use, copy, modify, and distribute this software for any
	7	* purpose with or without fee is hereby granted, provided that the above
	8	* copyright notice and this permission notice appear in all copies.
	9	*
	10	* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
	11	* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
	12	* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
	13	* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
	14	* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
	15	* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
	16	* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
	17	*/
	18
eac6e3f0	19	#include <zebra.h>
8429abe0	20
97b5d752	21	#include "memory.h"
cd85bc2e	22	#include "queue.h"
8429abe0 RW	23	#include "imsg.h"
8429abe0 RW	24
c17faa4b	25	static int imsg_fd_overhead = 0;
8429abe0	26
c17faa4b	27	static int imsg_get_fd(struct imsgbuf *);
8429abe0	28
eac6e3f0 RW	29	#ifndef __OpenBSD__
	30	/*
	31	* The original code calls getdtablecount() which is OpenBSD specific. Use
	32	* available_fds() from OpenSMTPD instead.
	33	*/
996c9314	34	static int available_fds(unsigned int n)
eac6e3f0	35	{
996c9314 LB	36	unsigned int i;
996c9314 LB	37	int ret, fds[256];
eac6e3f0	38
97b5d752	39	if (n > (unsigned int)array_size(fds))
eac6e3f0 RW	40	return (1);
	41
	42	ret = 0;
	43	for (i = 0; i < n; i++) {
	44	fds[i] = -1;
	45	if ((fds[i] = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
	46	if (errno == EAFNOSUPPORT \|\| errno == EPROTONOSUPPORT)
	47	fds[i] = socket(AF_INET6, SOCK_DGRAM, 0);
	48	if (fds[i] < 0) {
	49	ret = 1;
	50	break;
	51	}
	52	}
	53	}
	54
	55	for (i = 0; i < n && fds[i] >= 0; i++)
	56	close(fds[i]);
	57
	58	return (ret);
	59	}
	60	#endif
	61
996c9314	62	void imsg_init(struct imsgbuf *ibuf, int fd)
8429abe0 RW	63	{
	64	msgbuf_init(&ibuf->w);
	65	memset(&ibuf->r, 0, sizeof(ibuf->r));
	66	ibuf->fd = fd;
	67	ibuf->w.fd = fd;
	68	ibuf->pid = getpid();
	69	TAILQ_INIT(&ibuf->fds);
	70	}
	71
996c9314	72	ssize_t imsg_read(struct imsgbuf *ibuf)
8429abe0	73	{
996c9314 LB	74	struct msghdr msg;
996c9314 LB	75	struct cmsghdr *cmsg;
8429abe0 RW	76	union {
8429abe0 RW	77	struct cmsghdr hdr;
996c9314	78	char buf[CMSG_SPACE(sizeof(int) * 1)];
8429abe0	79	} cmsgbuf;
996c9314	80	struct iovec iov;
a2b6e694	81	ssize_t n;
996c9314 LB	82	int fd;
996c9314 LB	83	struct imsg_fd *ifd;
8429abe0 RW	84
	85	memset(&msg, 0, sizeof(msg));
	86	memset(&cmsgbuf, 0, sizeof(cmsgbuf));
	87
	88	iov.iov_base = ibuf->r.buf + ibuf->r.wpos;
	89	iov.iov_len = sizeof(ibuf->r.buf) - ibuf->r.wpos;
	90	msg.msg_iov = &iov;
	91	msg.msg_iovlen = 1;
	92	msg.msg_control = &cmsgbuf.buf;
	93	msg.msg_controllen = sizeof(cmsgbuf.buf);
	94
	95	if ((ifd = calloc(1, sizeof(struct imsg_fd))) == NULL)
	96	return (-1);
	97
	98	again:
eac6e3f0	99	#ifdef __OpenBSD__
996c9314 LB	100	if (getdtablecount() + imsg_fd_overhead
	101	+ (int)((CMSG_SPACE(sizeof(int)) - CMSG_SPACE(0))
	102	/ sizeof(int))
8429abe0	103	>= getdtablesize()) {
eac6e3f0	104	#else
996c9314 LB	105	if (available_fds(imsg_fd_overhead
	106	+ (CMSG_SPACE(sizeof(int)) - CMSG_SPACE(0))
	107	/ sizeof(int))) {
eac6e3f0	108	#endif
8429abe0 RW	109	errno = EAGAIN;
	110	free(ifd);
	111	return (-1);
	112	}
	113
a2b6e694	114	n = recvmsg(ibuf->fd, &msg, 0);
a2b6e694	115	if (n == -1) {
8429abe0 RW	116	if (errno == EINTR)
	117	goto again;
	118	goto fail;
	119	}
	120
	121	ibuf->r.wpos += n;
	122
	123	for (cmsg = CMSG_FIRSTHDR(&msg); cmsg != NULL;
996c9314 LB	124	cmsg = CMSG_NXTHDR(&msg, cmsg)) {
	125	if (cmsg->cmsg_level == SOL_SOCKET
	126	&& cmsg->cmsg_type == SCM_RIGHTS) {
8429abe0 RW	127	int i;
	128	int j;
	129
	130	/*
	131	* We only accept one file descriptor. Due to C
	132	* padding rules, our control buffer might contain
	133	* more than one fd, and we must close them.
	134	*/
996c9314 LB	135	j = ((char *)cmsg + cmsg->cmsg_len
	136	- (char *)CMSG_DATA(cmsg))
	137	/ sizeof(int);
8429abe0 RW	138	for (i = 0; i < j; i++) {
	139	fd = ((int *)CMSG_DATA(cmsg))[i];
	140	if (ifd != NULL) {
	141	ifd->fd = fd;
	142	TAILQ_INSERT_TAIL(&ibuf->fds, ifd,
996c9314	143	entry);
8429abe0 RW	144	ifd = NULL;
	145	} else
	146	close(fd);
	147	}
	148	}
	149	/* we do not handle other ctl data level */
	150	}
	151
	152	fail:
	153	free(ifd);
	154	return (n);
	155	}
	156
996c9314	157	ssize_t imsg_get(struct imsgbuf ibuf, struct imsg imsg)
8429abe0	158	{
996c9314	159	size_t av, left, datalen;
8429abe0 RW	160
	161	av = ibuf->r.wpos;
	162
	163	if (IMSG_HEADER_SIZE > av)
	164	return (0);
	165
	166	memcpy(&imsg->hdr, ibuf->r.buf, sizeof(imsg->hdr));
996c9314	167	if (imsg->hdr.len < IMSG_HEADER_SIZE \|\| imsg->hdr.len > MAX_IMSGSIZE) {
8429abe0 RW	168	errno = ERANGE;
	169	return (-1);
	170	}
	171	if (imsg->hdr.len > av)
	172	return (0);
	173	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
	174	ibuf->r.rptr = ibuf->r.buf + IMSG_HEADER_SIZE;
	175	if (datalen == 0)
	176	imsg->data = NULL;
	177	else if ((imsg->data = malloc(datalen)) == NULL)
	178	return (-1);
	179
	180	if (imsg->hdr.flags & IMSGF_HASFD)
	181	imsg->fd = imsg_get_fd(ibuf);
	182	else
	183	imsg->fd = -1;
	184
dd3415b7	185	if (imsg->data)
996c9314	186	memcpy(imsg->data, ibuf->r.rptr, datalen);
8429abe0 RW	187
	188	if (imsg->hdr.len < av) {
	189	left = av - imsg->hdr.len;
	190	memmove(&ibuf->r.buf, ibuf->r.buf + imsg->hdr.len, left);
	191	ibuf->r.wpos = left;
	192	} else
	193	ibuf->r.wpos = 0;
	194
	195	return (datalen + IMSG_HEADER_SIZE);
	196	}
	197
d7c0a89a QY	198	int imsg_compose(struct imsgbuf *ibuf, uint32_t type, uint32_t peerid,
d7c0a89a QY	199	pid_t pid, int fd, const void *data, uint16_t datalen)
8429abe0	200	{
996c9314	201	struct ibuf *wbuf;
8429abe0 RW	202
	203	if ((wbuf = imsg_create(ibuf, type, peerid, pid, datalen)) == NULL)
	204	return (-1);
	205
	206	if (imsg_add(wbuf, data, datalen) == -1)
	207	return (-1);
	208
	209	wbuf->fd = fd;
	210
	211	imsg_close(ibuf, wbuf);
	212
	213	return (1);
	214	}
	215
d7c0a89a	216	int imsg_composev(struct imsgbuf *ibuf, uint32_t type, uint32_t peerid,
996c9314	217	pid_t pid, int fd, const struct iovec *iov, int iovcnt)
8429abe0	218	{
996c9314 LB	219	struct ibuf *wbuf;
996c9314 LB	220	int i, datalen = 0;
8429abe0 RW	221
	222	for (i = 0; i < iovcnt; i++)
	223	datalen += iov[i].iov_len;
	224
	225	if ((wbuf = imsg_create(ibuf, type, peerid, pid, datalen)) == NULL)
	226	return (-1);
	227
	228	for (i = 0; i < iovcnt; i++)
	229	if (imsg_add(wbuf, iov[i].iov_base, iov[i].iov_len) == -1)
	230	return (-1);
	231
	232	wbuf->fd = fd;
	233
	234	imsg_close(ibuf, wbuf);
	235
	236	return (1);
	237	}
	238
	239	/* ARGSUSED */
d7c0a89a QY	240	struct ibuf imsg_create(struct imsgbuf ibuf, uint32_t type, uint32_t peerid,
d7c0a89a QY	241	pid_t pid, uint16_t datalen)
8429abe0	242	{
996c9314 LB	243	struct ibuf *wbuf;
996c9314 LB	244	struct imsg_hdr hdr;
8429abe0	245
c2fb17b5 QY	246	memset(&hdr, 0x00, IMSG_HEADER_SIZE);
c2fb17b5 QY	247
8429abe0 RW	248	datalen += IMSG_HEADER_SIZE;
	249	if (datalen > MAX_IMSGSIZE) {
	250	errno = ERANGE;
	251	return (NULL);
	252	}
	253
	254	hdr.type = type;
	255	hdr.flags = 0;
	256	hdr.peerid = peerid;
	257	if ((hdr.pid = pid) == 0)
	258	hdr.pid = ibuf->pid;
	259	if ((wbuf = ibuf_dynamic(datalen, MAX_IMSGSIZE)) == NULL) {
	260	return (NULL);
	261	}
	262	if (imsg_add(wbuf, &hdr, sizeof(hdr)) == -1)
	263	return (NULL);
	264
	265	return (wbuf);
	266	}
	267
d7c0a89a	268	int imsg_add(struct ibuf msg, const void data, uint16_t datalen)
8429abe0 RW	269	{
	270	if (datalen)
	271	if (ibuf_add(msg, data, datalen) == -1) {
	272	ibuf_free(msg);
	273	return (-1);
	274	}
	275	return (datalen);
	276	}
	277
996c9314	278	void imsg_close(struct imsgbuf ibuf, struct ibuf msg)
8429abe0	279	{
996c9314	280	struct imsg_hdr *hdr;
8429abe0 RW	281
	282	hdr = (struct imsg_hdr *)msg->buf;
	283
	284	hdr->flags &= ~IMSGF_HASFD;
	285	if (msg->fd != -1)
	286	hdr->flags \|= IMSGF_HASFD;
	287
d7c0a89a	288	hdr->len = (uint16_t)msg->wpos;
8429abe0 RW	289
	290	ibuf_close(&ibuf->w, msg);
	291	}
	292
996c9314	293	void imsg_free(struct imsg *imsg)
8429abe0 RW	294	{
	295	free(imsg->data);
	296	}
	297
996c9314	298	int imsg_get_fd(struct imsgbuf *ibuf)
8429abe0	299	{
996c9314 LB	300	int fd;
996c9314 LB	301	struct imsg_fd *ifd;
8429abe0	302
a43ad4fe	303	if ((ifd = TAILQ_POP_FIRST(&ibuf->fds, entry)) == NULL)
8429abe0 RW	304	return (-1);
	305
	306	fd = ifd->fd;
8429abe0 RW	307	free(ifd);
	308
	309	return (fd);
	310	}
	311
996c9314	312	int imsg_flush(struct imsgbuf *ibuf)
8429abe0 RW	313	{
	314	while (ibuf->w.queued)
	315	if (msgbuf_write(&ibuf->w) <= 0)
	316	return (-1);
	317	return (0);
	318	}
	319
996c9314	320	void imsg_clear(struct imsgbuf *ibuf)
8429abe0	321	{
996c9314	322	int fd;
8429abe0 RW	323
	324	msgbuf_clear(&ibuf->w);
	325	while ((fd = imsg_get_fd(ibuf)) != -1)
	326	close(fd);
	327	}