[linux-2.6-block.git] / net / 9p / protocol.c

/*
 * net/9p/protocol.c
 *
 * 9P Protocol Support Code
 *
 *  Copyright (C) 2008 by Eric Van Hensbergen <ericvh@gmail.com>
 *
 *  Base on code from Anthony Liguori <aliguori@us.ibm.com>
 *  Copyright (C) 2008 by IBM, Corp.
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License version 2
 *  as published by the Free Software Foundation.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to:
 *  Free Software Foundation
 *  51 Franklin Street, Fifth Floor
 *  Boston, MA  02111-1301  USA
 *
 */

#include <linux/module.h>
#include <linux/errno.h>
#include <linux/uaccess.h>
#include <net/9p/9p.h>
#include <net/9p/client.h>
#include "protocol.h"

#ifndef MIN
#define MIN(a, b) (((a) < (b)) ? (a) : (b))
#endif

#ifndef MAX
#define MAX(a, b) (((a) > (b)) ? (a) : (b))
#endif

#ifndef offset_of
#define offset_of(type, memb) \
	((unsigned long)(&((type *)0)->memb))
#endif
#ifndef container_of
#define container_of(obj, type, memb) \
	((type *)(((char *)obj) - offset_of(type, memb)))
#endif

static int
p9pdu_writef(struct p9_fcall *pdu, int optional, const char *fmt, ...);

#define PACKET_DEBUG 0

void
p9pdu_dump(int way, struct p9_fcall *pdu)
{
	int i, n;
	u8 *data = pdu->sdata;
	int datalen = pdu->size;
	char buf[255];
	int buflen = 255;

	i = n = 0;
	if (datalen > (buflen-16))
		datalen = buflen-16;
	while (i < datalen) {
		n += scnprintf(buf + n, buflen - n, "%02x ", data[i]);
		if (i%4 == 3)
			n += scnprintf(buf + n, buflen - n, " ");
		if (i%32 == 31)
			n += scnprintf(buf + n, buflen - n, "\n");

		i++;
	}
	n += scnprintf(buf + n, buflen - n, "\n");

	if (way)
		printk(KERN_NOTICE "[[(%d)[ %s\n", datalen, buf);
	else
		printk(KERN_NOTICE "]](%d)] %s\n", datalen, buf);
}
EXPORT_SYMBOL(p9pdu_dump);

void p9stat_free(struct p9_wstat *stbuf)
{
	kfree(stbuf->name);
	kfree(stbuf->uid);
	kfree(stbuf->gid);
	kfree(stbuf->muid);
	kfree(stbuf->extension);
}
EXPORT_SYMBOL(p9stat_free);

static size_t pdu_read(struct p9_fcall *pdu, void *data, size_t size)
{
	size_t len = MIN(pdu->size - pdu->offset, size);
	memcpy(data, &pdu->sdata[pdu->offset], len);
	pdu->offset += len;
	return size - len;
}

static size_t pdu_write(struct p9_fcall *pdu, const void *data, size_t size)
{
	size_t len = MIN(pdu->capacity - pdu->size, size);
	memcpy(&pdu->sdata[pdu->size], data, len);
	pdu->size += len;
	return size - len;
}

static size_t
pdu_write_u(struct p9_fcall *pdu, const char __user *udata, size_t size)
{
	size_t len = MIN(pdu->capacity - pdu->size, size);
	int err = copy_from_user(&pdu->sdata[pdu->size], udata, len);
	if (err)
		printk(KERN_WARNING "pdu_write_u returning: %d\n", err);

	pdu->size += len;
	return size - len;
}

/*
	b - int8_t
	w - int16_t
	d - int32_t
	q - int64_t
	s - string
	S - stat
	Q - qid
	D - data blob (int32_t size followed by void *, results are not freed)
	T - array of strings (int16_t count, followed by strings)
	R - array of qids (int16_t count, followed by qids)
	? - if optional = 1, continue parsing
*/

static int
p9pdu_vreadf(struct p9_fcall *pdu, int optional, const char *fmt, va_list ap)
{
	const char *ptr;
	int errcode = 0;

	for (ptr = fmt; *ptr; ptr++) {
		switch (*ptr) {
		case 'b':{
				int8_t *val = va_arg(ap, int8_t *);
				if (pdu_read(pdu, val, sizeof(*val))) {
					errcode = -EFAULT;
					break;
				}
			}
			break;
		case 'w':{
				int16_t *val = va_arg(ap, int16_t *);
				if (pdu_read(pdu, val, sizeof(*val))) {
					errcode = -EFAULT;
					break;
				}
				*val = cpu_to_le16(*val);
			}
			break;
		case 'd':{
				int32_t *val = va_arg(ap, int32_t *);
				if (pdu_read(pdu, val, sizeof(*val))) {
					errcode = -EFAULT;
					break;
				}
				*val = cpu_to_le32(*val);
			}
			break;
		case 'q':{
				int64_t *val = va_arg(ap, int64_t *);
				if (pdu_read(pdu, val, sizeof(*val))) {
					errcode = -EFAULT;
					break;
				}
				*val = cpu_to_le64(*val);
			}
			break;
		case 's':{
				char **ptr = va_arg(ap, char **);
				int16_t len;
				int size;

				errcode = p9pdu_readf(pdu, optional, "w", &len);
				if (errcode)
					break;

				size = MAX(len, 0);

				*ptr = kmalloc(size + 1, GFP_KERNEL);
				if (*ptr == NULL) {
					errcode = -EFAULT;
					break;
				}
				if (pdu_read(pdu, *ptr, size)) {
					errcode = -EFAULT;
					kfree(*ptr);
					*ptr = NULL;
				} else
					(*ptr)[size] = 0;
			}
			break;
		case 'Q':{
				struct p9_qid *qid =
				    va_arg(ap, struct p9_qid *);

				errcode = p9pdu_readf(pdu, optional, "bdq",
						      &qid->type, &qid->version,
						      &qid->path);
			}
			break;
		case 'S':{
				struct p9_wstat *stbuf =
				    va_arg(ap, struct p9_wstat *);

				stbuf->extension = NULL;
				stbuf->n_uid = stbuf->n_gid = stbuf->n_muid =
				    -1;
				errcode =
				    p9pdu_readf(pdu, optional,
						"wwdQdddqssss?sddd",
						&stbuf->size, &stbuf->type,
						&stbuf->dev, &stbuf->qid,
						&stbuf->mode, &stbuf->atime,
						&stbuf->mtime, &stbuf->length,
						&stbuf->name, &stbuf->uid,
						&stbuf->gid, &stbuf->muid,
						&stbuf->extension,
						&stbuf->n_uid, &stbuf->n_gid,
						&stbuf->n_muid);
				if (errcode)
					p9stat_free(stbuf);
			}
			break;
		case 'D':{
				int32_t *count = va_arg(ap, int32_t *);
				void **data = va_arg(ap, void **);

				errcode =
				    p9pdu_readf(pdu, optional, "d", count);
				if (!errcode) {
					*count =
					    MIN(*count,
						pdu->size - pdu->offset);
					*data = &pdu->sdata[pdu->offset];
				}
			}
			break;
		case 'T':{
				int16_t *nwname = va_arg(ap, int16_t *);
				char ***wnames = va_arg(ap, char ***);

				errcode =
				    p9pdu_readf(pdu, optional, "w", nwname);
				if (!errcode) {
					*wnames =
					    kmalloc(sizeof(char *) * *nwname,
						    GFP_KERNEL);
					if (!*wnames)
						errcode = -ENOMEM;
				}

				if (!errcode) {
					int i;

					for (i = 0; i < *nwname; i++) {
						errcode =
						    p9pdu_readf(pdu, optional,
								"s",
								&(*wnames)[i]);
						if (errcode)
							break;
					}
				}

				if (errcode) {
					if (*wnames) {
						int i;

						for (i = 0; i < *nwname; i++)
							kfree((*wnames)[i]);
					}
					kfree(*wnames);
					*wnames = NULL;
				}
			}
			break;
		case 'R':{
				int16_t *nwqid = va_arg(ap, int16_t *);
				struct p9_qid **wqids =
				    va_arg(ap, struct p9_qid **);

				*wqids = NULL;

				errcode =
				    p9pdu_readf(pdu, optional, "w", nwqid);
				if (!errcode) {
					*wqids =
					    kmalloc(*nwqid *
						    sizeof(struct p9_qid),
						    GFP_KERNEL);
					if (*wqids == NULL)
						errcode = -ENOMEM;
				}

				if (!errcode) {
					int i;

					for (i = 0; i < *nwqid; i++) {
						errcode =
						    p9pdu_readf(pdu, optional,
								"Q",
								&(*wqids)[i]);
						if (errcode)
							break;
					}
				}

				if (errcode) {
					kfree(*wqids);
					*wqids = NULL;
				}
			}
			break;
		case '?':
			if (!optional)
				return 0;
			break;
		default:
			BUG();
			break;
		}

		if (errcode)
			break;
	}

	return errcode;
}

int
p9pdu_vwritef(struct p9_fcall *pdu, int optional, const char *fmt, va_list ap)
{
	const char *ptr;
	int errcode = 0;

	for (ptr = fmt; *ptr; ptr++) {
		switch (*ptr) {
		case 'b':{
				int8_t val = va_arg(ap, int);
				if (pdu_write(pdu, &val, sizeof(val)))
					errcode = -EFAULT;
			}
			break;
		case 'w':{
				int16_t val = va_arg(ap, int);
				if (pdu_write(pdu, &val, sizeof(val)))
					errcode = -EFAULT;
			}
			break;
		case 'd':{
				int32_t val = va_arg(ap, int32_t);
				if (pdu_write(pdu, &val, sizeof(val)))
					errcode = -EFAULT;
			}
			break;
		case 'q':{
				int64_t val = va_arg(ap, int64_t);
				if (pdu_write(pdu, &val, sizeof(val)))
					errcode = -EFAULT;
			}
			break;
		case 's':{
				const char *ptr = va_arg(ap, const char *);
				int16_t len = 0;
				if (ptr)
					len = MIN(strlen(ptr), USHORT_MAX);

				errcode = p9pdu_writef(pdu, optional, "w", len);
				if (!errcode && pdu_write(pdu, ptr, len))
					errcode = -EFAULT;
			}
			break;
		case 'Q':{
				const struct p9_qid *qid =
				    va_arg(ap, const struct p9_qid *);
				errcode =
				    p9pdu_writef(pdu, optional, "bdq",
						 qid->type, qid->version,
						 qid->path);
			} break;
		case 'S':{
				const struct p9_wstat *stbuf =
				    va_arg(ap, const struct p9_wstat *);
				errcode =
				    p9pdu_writef(pdu, optional,
						 "wwdQdddqssss?sddd",
						 stbuf->size, stbuf->type,
						 stbuf->dev, &stbuf->qid,
						 stbuf->mode, stbuf->atime,
						 stbuf->mtime, stbuf->length,
						 stbuf->name, stbuf->uid,
						 stbuf->gid, stbuf->muid,
						 stbuf->extension, stbuf->n_uid,
						 stbuf->n_gid, stbuf->n_muid);
			} break;
		case 'D':{
				int32_t count = va_arg(ap, int32_t);
				const void *data = va_arg(ap, const void *);

				errcode =
				    p9pdu_writef(pdu, optional, "d", count);
				if (!errcode && pdu_write(pdu, data, count))
					errcode = -EFAULT;
			}
			break;
		case 'U':{
				int32_t count = va_arg(ap, int32_t);
				const char __user *udata =
						va_arg(ap, const void *);
				errcode =
				    p9pdu_writef(pdu, optional, "d", count);
				if (!errcode && pdu_write_u(pdu, udata, count))
					errcode = -EFAULT;
			}
			break;
		case 'T':{
				int16_t nwname = va_arg(ap, int);
				const char **wnames = va_arg(ap, const char **);

				errcode =
				    p9pdu_writef(pdu, optional, "w", nwname);
				if (!errcode) {
					int i;

					for (i = 0; i < nwname; i++) {
						errcode =
						    p9pdu_writef(pdu, optional,
								 "s",
								 wnames[i]);
						if (errcode)
							break;
					}
				}
			}
			break;
		case 'R':{
				int16_t nwqid = va_arg(ap, int);
				struct p9_qid *wqids =
				    va_arg(ap, struct p9_qid *);

				errcode =
				    p9pdu_writef(pdu, optional, "w", nwqid);
				if (!errcode) {
					int i;

					for (i = 0; i < nwqid; i++) {
						errcode =
						    p9pdu_writef(pdu, optional,
								 "Q",
								 &wqids[i]);
						if (errcode)
							break;
					}
				}
			}
			break;
		case '?':
			if (!optional)
				return 0;
			break;
		default:
			BUG();
			break;
		}

		if (errcode)
			break;
	}

	return errcode;
}

int p9pdu_readf(struct p9_fcall *pdu, int optional, const char *fmt, ...)
{
	va_list ap;
	int ret;

	va_start(ap, fmt);
	ret = p9pdu_vreadf(pdu, optional, fmt, ap);
	va_end(ap);

	return ret;
}

static int
p9pdu_writef(struct p9_fcall *pdu, int optional, const char *fmt, ...)
{
	va_list ap;
	int ret;

	va_start(ap, fmt);
	ret = p9pdu_vwritef(pdu, optional, fmt, ap);
	va_end(ap);

	return ret;
}

int p9pdu_prepare(struct p9_fcall *pdu, int16_t tag, int8_t type)
{
	return p9pdu_writef(pdu, 0, "dbw", 0, type, tag);
}

int p9pdu_finalize(struct p9_fcall *pdu)
{
	int size = pdu->size;
	int err;

	pdu->size = 0;
	err = p9pdu_writef(pdu, 0, "d", size);
	pdu->size = size;

	if (PACKET_DEBUG)
		p9pdu_dump(0, pdu);

	return err;
}

void p9pdu_reset(struct p9_fcall *pdu)
{
	pdu->offset = 0;
	pdu->size = 0;
}
Commit	Line	Data
ace51c4d EVH	1	/*
	2	* net/9p/protocol.c
	3	*
	4	* 9P Protocol Support Code
	5	*
	6	* Copyright (C) 2008 by Eric Van Hensbergen <ericvh@gmail.com>
	7	*
	8	* Base on code from Anthony Liguori <aliguori@us.ibm.com>
	9	* Copyright (C) 2008 by IBM, Corp.
	10	*
	11	* This program is free software; you can redistribute it and/or modify
	12	* it under the terms of the GNU General Public License version 2
	13	* as published by the Free Software Foundation.
	14	*
	15	* This program is distributed in the hope that it will be useful,
	16	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	17	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	18	* GNU General Public License for more details.
	19	*
	20	* You should have received a copy of the GNU General Public License
	21	* along with this program; if not, write to:
	22	* Free Software Foundation
	23	* 51 Franklin Street, Fifth Floor
	24	* Boston, MA 02111-1301 USA
	25	*
	26	*/
	27
	28	#include <linux/module.h>
	29	#include <linux/errno.h>
51a87c55	30	#include <linux/uaccess.h>
ace51c4d EVH	31	#include <net/9p/9p.h>
	32	#include <net/9p/client.h>
	33	#include "protocol.h"
	34
	35	#ifndef MIN
	36	#define MIN(a, b) (((a) < (b)) ? (a) : (b))
	37	#endif
	38
	39	#ifndef MAX
	40	#define MAX(a, b) (((a) > (b)) ? (a) : (b))
	41	#endif
	42
	43	#ifndef offset_of
	44	#define offset_of(type, memb) \
	45	((unsigned long)(&((type *)0)->memb))
	46	#endif
	47	#ifndef container_of
	48	#define container_of(obj, type, memb) \
	49	((type )(((char )obj) - offset_of(type, memb)))
	50	#endif
	51
	52	static int
	53	p9pdu_writef(struct p9_fcall pdu, int optional, const char fmt, ...);
	54
51a87c55 EVH	55	#define PACKET_DEBUG 0
	56
	57	void
	58	p9pdu_dump(int way, struct p9_fcall *pdu)
	59	{
	60	int i, n;
	61	u8 *data = pdu->sdata;
	62	int datalen = pdu->size;
	63	char buf[255];
	64	int buflen = 255;
	65
	66	i = n = 0;
	67	if (datalen > (buflen-16))
	68	datalen = buflen-16;
	69	while (i < datalen) {
	70	n += scnprintf(buf + n, buflen - n, "%02x ", data[i]);
	71	if (i%4 == 3)
	72	n += scnprintf(buf + n, buflen - n, " ");
	73	if (i%32 == 31)
	74	n += scnprintf(buf + n, buflen - n, "\n");
	75
	76	i++;
	77	}
	78	n += scnprintf(buf + n, buflen - n, "\n");
	79
	80	if (way)
	81	printk(KERN_NOTICE "[[(%d)[ %s\n", datalen, buf);
	82	else
	83	printk(KERN_NOTICE "]](%d)] %s\n", datalen, buf);
	84	}
	85	EXPORT_SYMBOL(p9pdu_dump);
	86
ace51c4d EVH	87	void p9stat_free(struct p9_wstat *stbuf)
	88	{
	89	kfree(stbuf->name);
	90	kfree(stbuf->uid);
	91	kfree(stbuf->gid);
	92	kfree(stbuf->muid);
	93	kfree(stbuf->extension);
	94	}
	95	EXPORT_SYMBOL(p9stat_free);
	96
	97	static size_t pdu_read(struct p9_fcall pdu, void data, size_t size)
	98	{
	99	size_t len = MIN(pdu->size - pdu->offset, size);
	100	memcpy(data, &pdu->sdata[pdu->offset], len);
	101	pdu->offset += len;
	102	return size - len;
	103	}
	104
	105	static size_t pdu_write(struct p9_fcall pdu, const void data, size_t size)
	106	{
	107	size_t len = MIN(pdu->capacity - pdu->size, size);
	108	memcpy(&pdu->sdata[pdu->size], data, len);
	109	pdu->size += len;
	110	return size - len;
	111	}
	112
51a87c55 EVH	113	static size_t
	114	pdu_write_u(struct p9_fcall pdu, const char __user udata, size_t size)
	115	{
	116	size_t len = MIN(pdu->capacity - pdu->size, size);
	117	int err = copy_from_user(&pdu->sdata[pdu->size], udata, len);
	118	if (err)
	119	printk(KERN_WARNING "pdu_write_u returning: %d\n", err);
	120
	121	pdu->size += len;
	122	return size - len;
	123	}
	124
ace51c4d EVH	125	/*
	126	b - int8_t
	127	w - int16_t
	128	d - int32_t
	129	q - int64_t
	130	s - string
	131	S - stat
	132	Q - qid
	133	D - data blob (int32_t size followed by void *, results are not freed)
	134	T - array of strings (int16_t count, followed by strings)
	135	R - array of qids (int16_t count, followed by qids)
	136	? - if optional = 1, continue parsing
	137	*/
	138
	139	static int
	140	p9pdu_vreadf(struct p9_fcall pdu, int optional, const char fmt, va_list ap)
	141	{
	142	const char *ptr;
	143	int errcode = 0;
	144
	145	for (ptr = fmt; *ptr; ptr++) {
	146	switch (*ptr) {
	147	case 'b':{
	148	int8_t val = va_arg(ap, int8_t );
	149	if (pdu_read(pdu, val, sizeof(*val))) {
	150	errcode = -EFAULT;
	151	break;
	152	}
	153	}
	154	break;
	155	case 'w':{
	156	int16_t val = va_arg(ap, int16_t );
	157	if (pdu_read(pdu, val, sizeof(*val))) {
	158	errcode = -EFAULT;
	159	break;
	160	}
	161	val = cpu_to_le16(val);
	162	}
	163	break;
	164	case 'd':{
	165	int32_t val = va_arg(ap, int32_t );
	166	if (pdu_read(pdu, val, sizeof(*val))) {
	167	errcode = -EFAULT;
	168	break;
	169	}
	170	val = cpu_to_le32(val);
	171	}
	172	break;
	173	case 'q':{
	174	int64_t val = va_arg(ap, int64_t );
	175	if (pdu_read(pdu, val, sizeof(*val))) {
	176	errcode = -EFAULT;
	177	break;
	178	}
	179	val = cpu_to_le64(val);
	180	}
	181	break;
	182	case 's':{
	183	char ptr = va_arg(ap, char );
	184	int16_t len;
	185	int size;
	186
	187	errcode = p9pdu_readf(pdu, optional, "w", &len);
	188	if (errcode)
189	break;
190
191	size = MAX(len, 0);
192
193	*ptr = kmalloc(size + 1, GFP_KERNEL);
194	if (*ptr == NULL) {
195	errcode = -EFAULT;
196	break;
197	}
198	if (pdu_read(pdu, *ptr, size)) {
199	errcode = -EFAULT;
200	kfree(*ptr);
201	*ptr = NULL;
202	} else
203	(*ptr)[size] = 0;
204	}
205	break;
206	case 'Q':{
207	struct p9_qid *qid =
208	va_arg(ap, struct p9_qid *);
209
210	errcode = p9pdu_readf(pdu, optional, "bdq",
211	&qid->type, &qid->version,
212	&qid->path);
213	}
214	break;
215	case 'S':{
216	struct p9_wstat *stbuf =
217	va_arg(ap, struct p9_wstat *);
218
219	stbuf->extension = NULL;
220	stbuf->n_uid = stbuf->n_gid = stbuf->n_muid =
221	-1;
ace51c4d EVH	222	errcode =
	223	p9pdu_readf(pdu, optional,
	224	"wwdQdddqssss?sddd",
	225	&stbuf->size, &stbuf->type,
	226	&stbuf->dev, &stbuf->qid,
	227	&stbuf->mode, &stbuf->atime,
	228	&stbuf->mtime, &stbuf->length,
	229	&stbuf->name, &stbuf->uid,
	230	&stbuf->gid, &stbuf->muid,
	231	&stbuf->extension,
	232	&stbuf->n_uid, &stbuf->n_gid,
	233	&stbuf->n_muid);
	234	if (errcode)
	235	p9stat_free(stbuf);
	236	}
	237	break;
	238	case 'D':{
	239	int32_t count = va_arg(ap, int32_t );
	240	void data = va_arg(ap, void );
	241
	242	errcode =
	243	p9pdu_readf(pdu, optional, "d", count);
	244	if (!errcode) {
	245	*count =
	246	MIN(*count,
	247	pdu->size - pdu->offset);
	248	*data = &pdu->sdata[pdu->offset];
	249	}
	250	}
	251	break;
	252	case 'T':{
	253	int16_t nwname = va_arg(ap, int16_t );
	254	char *wnames = va_arg(ap, char *);
	255
	256	errcode =
	257	p9pdu_readf(pdu, optional, "w", nwname);
	258	if (!errcode) {
	259	*wnames =
	260	kmalloc(sizeof(char ) *nwname,
	261	GFP_KERNEL);
	262	if (!*wnames)
	263	errcode = -ENOMEM;
	264	}
	265
	266	if (!errcode) {
	267	int i;
	268
	269	for (i = 0; i < *nwname; i++) {
	270	errcode =
	271	p9pdu_readf(pdu, optional,
	272	"s",
	273	&(*wnames)[i]);
	274	if (errcode)
	275	break;
	276	}
	277	}
	278
	279	if (errcode) {
	280	if (*wnames) {
	281	int i;
	282
	283	for (i = 0; i < *nwname; i++)
	284	kfree((*wnames)[i]);
	285	}
286	kfree(*wnames);
287	*wnames = NULL;
288	}
289	}
290	break;
291	case 'R':{
292	int16_t nwqid = va_arg(ap, int16_t );
293	struct p9_qid **wqids =
294	va_arg(ap, struct p9_qid **);
295
296	*wqids = NULL;
297
298	errcode =
299	p9pdu_readf(pdu, optional, "w", nwqid);
300	if (!errcode) {
301	*wqids =
302	kmalloc(nwqid
303	sizeof(struct p9_qid),
304	GFP_KERNEL);
305	if (*wqids == NULL)
306	errcode = -ENOMEM;
307	}
308
309	if (!errcode) {
310	int i;
311
312	for (i = 0; i < *nwqid; i++) {
313	errcode =
314	p9pdu_readf(pdu, optional,
315	"Q",
316	&(*wqids)[i]);
317	if (errcode)
318	break;
319	}
320	}
321
322	if (errcode) {
323	kfree(*wqids);
324	*wqids = NULL;
325	}
326	}
327	break;
328	case '?':
329	if (!optional)
330	return 0;
331	break;
332	default:
333	BUG();
334	break;
335	}
336
337	if (errcode)
338	break;
339	}
340
341	return errcode;
342	}
343
344	int
345	p9pdu_vwritef(struct p9_fcall pdu, int optional, const char fmt, va_list ap)
346	{
347	const char *ptr;
348	int errcode = 0;
349
350	for (ptr = fmt; *ptr; ptr++) {
351	switch (*ptr) {
352	case 'b':{
353	int8_t val = va_arg(ap, int);
354	if (pdu_write(pdu, &val, sizeof(val)))
355	errcode = -EFAULT;
356	}
357	break;
358	case 'w':{
359	int16_t val = va_arg(ap, int);
360	if (pdu_write(pdu, &val, sizeof(val)))
361	errcode = -EFAULT;
362	}
363	break;
364	case 'd':{
365	int32_t val = va_arg(ap, int32_t);
366	if (pdu_write(pdu, &val, sizeof(val)))
367	errcode = -EFAULT;
368	}
369	break;
370	case 'q':{
371	int64_t val = va_arg(ap, int64_t);
372	if (pdu_write(pdu, &val, sizeof(val)))
373	errcode = -EFAULT;
374	}
375	break;
376	case 's':{
377	const char ptr = va_arg(ap, const char );
378	int16_t len = 0;
ace51c4d EVH	379	if (ptr)
	380	len = MIN(strlen(ptr), USHORT_MAX);
	381
	382	errcode = p9pdu_writef(pdu, optional, "w", len);
	383	if (!errcode && pdu_write(pdu, ptr, len))
	384	errcode = -EFAULT;
	385	}
	386	break;
	387	case 'Q':{
	388	const struct p9_qid *qid =
	389	va_arg(ap, const struct p9_qid *);
	390	errcode =
	391	p9pdu_writef(pdu, optional, "bdq",
	392	qid->type, qid->version,
	393	qid->path);
	394	} break;
	395	case 'S':{
	396	const struct p9_wstat *stbuf =
	397	va_arg(ap, const struct p9_wstat *);
	398	errcode =
	399	p9pdu_writef(pdu, optional,
	400	"wwdQdddqssss?sddd",
	401	stbuf->size, stbuf->type,
51a87c55	402	stbuf->dev, &stbuf->qid,
ace51c4d EVH	403	stbuf->mode, stbuf->atime,
	404	stbuf->mtime, stbuf->length,
	405	stbuf->name, stbuf->uid,
	406	stbuf->gid, stbuf->muid,
	407	stbuf->extension, stbuf->n_uid,
	408	stbuf->n_gid, stbuf->n_muid);
	409	} break;
	410	case 'D':{
	411	int32_t count = va_arg(ap, int32_t);
	412	const void data = va_arg(ap, const void );
	413
	414	errcode =
	415	p9pdu_writef(pdu, optional, "d", count);
	416	if (!errcode && pdu_write(pdu, data, count))
	417	errcode = -EFAULT;
	418	}
	419	break;
51a87c55 EVH	420	case 'U':{
	421	int32_t count = va_arg(ap, int32_t);
	422	const char __user *udata =
	423	va_arg(ap, const void *);
	424	errcode =
	425	p9pdu_writef(pdu, optional, "d", count);
	426	if (!errcode && pdu_write_u(pdu, udata, count))
	427	errcode = -EFAULT;
	428	}
	429	break;
ace51c4d EVH	430	case 'T':{
	431	int16_t nwname = va_arg(ap, int);
	432	const char wnames = va_arg(ap, const char );
	433
	434	errcode =
	435	p9pdu_writef(pdu, optional, "w", nwname);
	436	if (!errcode) {
	437	int i;
	438
	439	for (i = 0; i < nwname; i++) {
	440	errcode =
	441	p9pdu_writef(pdu, optional,
	442	"s",
	443	wnames[i]);
	444	if (errcode)
	445	break;
	446	}
	447	}
	448	}
	449	break;
	450	case 'R':{
	451	int16_t nwqid = va_arg(ap, int);
	452	struct p9_qid *wqids =
	453	va_arg(ap, struct p9_qid *);
	454
	455	errcode =
	456	p9pdu_writef(pdu, optional, "w", nwqid);
	457	if (!errcode) {
	458	int i;
	459
	460	for (i = 0; i < nwqid; i++) {
	461	errcode =
	462	p9pdu_writef(pdu, optional,
	463	"Q",
	464	&wqids[i]);
	465	if (errcode)
	466	break;
	467	}
	468	}
	469	}
	470	break;
	471	case '?':
	472	if (!optional)
	473	return 0;
	474	break;
	475	default:
	476	BUG();
	477	break;
	478	}
	479
	480	if (errcode)
	481	break;
	482	}
	483
	484	return errcode;
	485	}
	486
	487	int p9pdu_readf(struct p9_fcall pdu, int optional, const char fmt, ...)
	488	{
	489	va_list ap;
	490	int ret;
	491
	492	va_start(ap, fmt);
	493	ret = p9pdu_vreadf(pdu, optional, fmt, ap);
494	va_end(ap);
495
496	return ret;
497	}
498
499	static int
500	p9pdu_writef(struct p9_fcall pdu, int optional, const char fmt, ...)
501	{
502	va_list ap;
503	int ret;
504
505	va_start(ap, fmt);
506	ret = p9pdu_vwritef(pdu, optional, fmt, ap);
507	va_end(ap);
508
509	return ret;
510	}
51a87c55 EVH	511
	512	int p9pdu_prepare(struct p9_fcall *pdu, int16_t tag, int8_t type)
	513	{
	514	return p9pdu_writef(pdu, 0, "dbw", 0, type, tag);
	515	}
	516
	517	int p9pdu_finalize(struct p9_fcall *pdu)
	518	{
	519	int size = pdu->size;
	520	int err;
	521
	522	pdu->size = 0;
	523	err = p9pdu_writef(pdu, 0, "d", size);
	524	pdu->size = size;
	525
	526	if (PACKET_DEBUG)
	527	p9pdu_dump(0, pdu);
	528
	529	return err;
	530	}
	531
	532	void p9pdu_reset(struct p9_fcall *pdu)
	533	{
	534	pdu->offset = 0;
	535	pdu->size = 0;
	536	}