[mirror_ubuntu-artful-kernel.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 <linux/sched.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, ...);

#ifdef CONFIG_NET_9P_DEBUG
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)
		P9_DPRINTK(P9_DEBUG_PKT, "[[[(%d) %s\n", datalen, buf);
	else
		P9_DPRINTK(P9_DEBUG_PKT, "]]](%d) %s\n", datalen, buf);
}
#else
void
p9pdu_dump(int way, struct p9_fcall *pdu)
{
}
#endif
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 *);

				memset(stbuf, 0, sizeof(struct p9_wstat));
				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 p9stat_read(char *buf, int len, struct p9_wstat *st, int dotu)
{
	struct p9_fcall fake_pdu;
	int ret;

	fake_pdu.size = len;
	fake_pdu.capacity = len;
	fake_pdu.sdata = buf;
	fake_pdu.offset = 0;

	ret = p9pdu_readf(&fake_pdu, dotu, "S", st);
	if (ret) {
		P9_DPRINTK(P9_DEBUG_9P, "<<< p9stat_read failed: %d\n", ret);
		p9pdu_dump(1, &fake_pdu);
	}

	return ret;
}
EXPORT_SYMBOL(p9stat_read);

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;

#ifdef CONFIG_NET_9P_DEBUG
	if ((p9_debug_level & P9_DEBUG_PKT) == P9_DEBUG_PKT)
		p9pdu_dump(0, pdu);
#endif

	P9_DPRINTK(P9_DEBUG_9P, ">>> size=%d type: %d tag: %d\n", pdu->size,
							pdu->id, pdu->tag);

	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>
e7f4b8f1	31	#include <linux/sched.h>
ace51c4d EVH	32	#include <net/9p/9p.h>
	33	#include <net/9p/client.h>
	34	#include "protocol.h"
	35
	36	#ifndef MIN
	37	#define MIN(a, b) (((a) < (b)) ? (a) : (b))
	38	#endif
	39
	40	#ifndef MAX
	41	#define MAX(a, b) (((a) > (b)) ? (a) : (b))
	42	#endif
	43
	44	#ifndef offset_of
	45	#define offset_of(type, memb) \
	46	((unsigned long)(&((type *)0)->memb))
	47	#endif
	48	#ifndef container_of
	49	#define container_of(obj, type, memb) \
	50	((type )(((char )obj) - offset_of(type, memb)))
	51	#endif
	52
	53	static int
	54	p9pdu_writef(struct p9_fcall pdu, int optional, const char fmt, ...);
	55
0b15a3a5	56	#ifdef CONFIG_NET_9P_DEBUG
51a87c55 EVH	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)
e7f4b8f1	81	P9_DPRINTK(P9_DEBUG_PKT, "[[[(%d) %s\n", datalen, buf);
51a87c55	82	else
e7f4b8f1	83	P9_DPRINTK(P9_DEBUG_PKT, "]]](%d) %s\n", datalen, buf);
51a87c55	84	}
0b15a3a5 EVH	85	#else
	86	void
	87	p9pdu_dump(int way, struct p9_fcall *pdu)
	88	{
	89	}
	90	#endif
51a87c55 EVH	91	EXPORT_SYMBOL(p9pdu_dump);
51a87c55 EVH	92
ace51c4d EVH	93	void p9stat_free(struct p9_wstat *stbuf)
	94	{
	95	kfree(stbuf->name);
	96	kfree(stbuf->uid);
	97	kfree(stbuf->gid);
	98	kfree(stbuf->muid);
	99	kfree(stbuf->extension);
	100	}
	101	EXPORT_SYMBOL(p9stat_free);
	102
	103	static size_t pdu_read(struct p9_fcall pdu, void data, size_t size)
	104	{
	105	size_t len = MIN(pdu->size - pdu->offset, size);
	106	memcpy(data, &pdu->sdata[pdu->offset], len);
	107	pdu->offset += len;
	108	return size - len;
	109	}
	110
	111	static size_t pdu_write(struct p9_fcall pdu, const void data, size_t size)
	112	{
	113	size_t len = MIN(pdu->capacity - pdu->size, size);
	114	memcpy(&pdu->sdata[pdu->size], data, len);
	115	pdu->size += len;
	116	return size - len;
	117	}
	118
51a87c55 EVH	119	static size_t
	120	pdu_write_u(struct p9_fcall pdu, const char __user udata, size_t size)
	121	{
	122	size_t len = MIN(pdu->capacity - pdu->size, size);
	123	int err = copy_from_user(&pdu->sdata[pdu->size], udata, len);
	124	if (err)
	125	printk(KERN_WARNING "pdu_write_u returning: %d\n", err);
	126
	127	pdu->size += len;
	128	return size - len;
	129	}
	130
ace51c4d EVH	131	/*
	132	b - int8_t
	133	w - int16_t
	134	d - int32_t
	135	q - int64_t
	136	s - string
	137	S - stat
	138	Q - qid
	139	D - data blob (int32_t size followed by void *, results are not freed)
	140	T - array of strings (int16_t count, followed by strings)
	141	R - array of qids (int16_t count, followed by qids)
	142	? - if optional = 1, continue parsing
	143	*/
	144
	145	static int
	146	p9pdu_vreadf(struct p9_fcall pdu, int optional, const char fmt, va_list ap)
	147	{
	148	const char *ptr;
	149	int errcode = 0;
	150
	151	for (ptr = fmt; *ptr; ptr++) {
	152	switch (*ptr) {
	153	case 'b':{
	154	int8_t val = va_arg(ap, int8_t );
	155	if (pdu_read(pdu, val, sizeof(*val))) {
	156	errcode = -EFAULT;
	157	break;
	158	}
	159	}
	160	break;
	161	case 'w':{
	162	int16_t val = va_arg(ap, int16_t );
	163	if (pdu_read(pdu, val, sizeof(*val))) {
	164	errcode = -EFAULT;
	165	break;
	166	}
	167	val = cpu_to_le16(val);
	168	}
	169	break;
	170	case 'd':{
	171	int32_t val = va_arg(ap, int32_t );
	172	if (pdu_read(pdu, val, sizeof(*val))) {
	173	errcode = -EFAULT;
	174	break;
	175	}
	176	val = cpu_to_le32(val);
	177	}
	178	break;
	179	case 'q':{
	180	int64_t val = va_arg(ap, int64_t );
	181	if (pdu_read(pdu, val, sizeof(*val))) {
	182	errcode = -EFAULT;
	183	break;
	184	}
	185	val = cpu_to_le64(val);
	186	}
	187	break;
	188	case 's':{
	189	char ptr = va_arg(ap, char );
	190	int16_t len;
	191	int size;
	192
	193	errcode = p9pdu_readf(pdu, optional, "w", &len);
	194	if (errcode)
195	break;
196
197	size = MAX(len, 0);
198
199	*ptr = kmalloc(size + 1, GFP_KERNEL);
200	if (*ptr == NULL) {
201	errcode = -EFAULT;
202	break;
203	}
204	if (pdu_read(pdu, *ptr, size)) {
205	errcode = -EFAULT;
206	kfree(*ptr);
207	*ptr = NULL;
208	} else
209	(*ptr)[size] = 0;
210	}
211	break;
212	case 'Q':{
213	struct p9_qid *qid =
214	va_arg(ap, struct p9_qid *);
215
216	errcode = p9pdu_readf(pdu, optional, "bdq",
217	&qid->type, &qid->version,
218	&qid->path);
219	}
220	break;
221	case 'S':{
222	struct p9_wstat *stbuf =
223	va_arg(ap, struct p9_wstat *);
224
f0a0ac2e	225	memset(stbuf, 0, sizeof(struct p9_wstat));
ace51c4d	226	stbuf->n_uid = stbuf->n_gid = stbuf->n_muid =
f0a0ac2e	227	-1;
ace51c4d EVH	228	errcode =
	229	p9pdu_readf(pdu, optional,
	230	"wwdQdddqssss?sddd",
	231	&stbuf->size, &stbuf->type,
	232	&stbuf->dev, &stbuf->qid,
	233	&stbuf->mode, &stbuf->atime,
	234	&stbuf->mtime, &stbuf->length,
	235	&stbuf->name, &stbuf->uid,
	236	&stbuf->gid, &stbuf->muid,
	237	&stbuf->extension,
	238	&stbuf->n_uid, &stbuf->n_gid,
	239	&stbuf->n_muid);
	240	if (errcode)
	241	p9stat_free(stbuf);
	242	}
	243	break;
	244	case 'D':{
	245	int32_t count = va_arg(ap, int32_t );
	246	void data = va_arg(ap, void );
	247
	248	errcode =
	249	p9pdu_readf(pdu, optional, "d", count);
	250	if (!errcode) {
	251	*count =
	252	MIN(*count,
	253	pdu->size - pdu->offset);
	254	*data = &pdu->sdata[pdu->offset];
	255	}
	256	}
	257	break;
	258	case 'T':{
	259	int16_t nwname = va_arg(ap, int16_t );
	260	char *wnames = va_arg(ap, char *);
	261
	262	errcode =
	263	p9pdu_readf(pdu, optional, "w", nwname);
	264	if (!errcode) {
	265	*wnames =
	266	kmalloc(sizeof(char ) *nwname,
	267	GFP_KERNEL);
	268	if (!*wnames)
	269	errcode = -ENOMEM;
	270	}
	271
	272	if (!errcode) {
	273	int i;
	274
	275	for (i = 0; i < *nwname; i++) {
	276	errcode =
	277	p9pdu_readf(pdu, optional,
	278	"s",
	279	&(*wnames)[i]);
	280	if (errcode)
	281	break;
	282	}
	283	}
	284
	285	if (errcode) {
	286	if (*wnames) {
	287	int i;
	288
	289	for (i = 0; i < *nwname; i++)
	290	kfree((*wnames)[i]);
	291	}
292	kfree(*wnames);
293	*wnames = NULL;
294	}
295	}
296	break;
297	case 'R':{
298	int16_t nwqid = va_arg(ap, int16_t );
299	struct p9_qid **wqids =
300	va_arg(ap, struct p9_qid **);
301
302	*wqids = NULL;
303
304	errcode =
305	p9pdu_readf(pdu, optional, "w", nwqid);
306	if (!errcode) {
307	*wqids =
308	kmalloc(nwqid
309	sizeof(struct p9_qid),
310	GFP_KERNEL);
311	if (*wqids == NULL)
312	errcode = -ENOMEM;
313	}
314
315	if (!errcode) {
316	int i;
317
318	for (i = 0; i < *nwqid; i++) {
319	errcode =
320	p9pdu_readf(pdu, optional,
321	"Q",
322	&(*wqids)[i]);
323	if (errcode)
324	break;
325	}
326	}
327
328	if (errcode) {
329	kfree(*wqids);
330	*wqids = NULL;
331	}
332	}
333	break;
334	case '?':
335	if (!optional)
336	return 0;
337	break;
338	default:
339	BUG();
340	break;
341	}
342
343	if (errcode)
344	break;
345	}
346
347	return errcode;
348	}
349
350	int
351	p9pdu_vwritef(struct p9_fcall pdu, int optional, const char fmt, va_list ap)
352	{
353	const char *ptr;
354	int errcode = 0;
355
356	for (ptr = fmt; *ptr; ptr++) {
357	switch (*ptr) {
358	case 'b':{
359	int8_t val = va_arg(ap, int);
360	if (pdu_write(pdu, &val, sizeof(val)))
361	errcode = -EFAULT;
362	}
363	break;
364	case 'w':{
365	int16_t val = va_arg(ap, int);
366	if (pdu_write(pdu, &val, sizeof(val)))
367	errcode = -EFAULT;
368	}
369	break;
370	case 'd':{
371	int32_t val = va_arg(ap, int32_t);
372	if (pdu_write(pdu, &val, sizeof(val)))
373	errcode = -EFAULT;
374	}
375	break;
376	case 'q':{
377	int64_t val = va_arg(ap, int64_t);
378	if (pdu_write(pdu, &val, sizeof(val)))
379	errcode = -EFAULT;
380	}
381	break;
382	case 's':{
383	const char ptr = va_arg(ap, const char );
384	int16_t len = 0;
ace51c4d EVH	385	if (ptr)
	386	len = MIN(strlen(ptr), USHORT_MAX);
	387
	388	errcode = p9pdu_writef(pdu, optional, "w", len);
	389	if (!errcode && pdu_write(pdu, ptr, len))
	390	errcode = -EFAULT;
	391	}
	392	break;
	393	case 'Q':{
	394	const struct p9_qid *qid =
	395	va_arg(ap, const struct p9_qid *);
	396	errcode =
	397	p9pdu_writef(pdu, optional, "bdq",
	398	qid->type, qid->version,
	399	qid->path);
	400	} break;
	401	case 'S':{
	402	const struct p9_wstat *stbuf =
	403	va_arg(ap, const struct p9_wstat *);
	404	errcode =
	405	p9pdu_writef(pdu, optional,
	406	"wwdQdddqssss?sddd",
	407	stbuf->size, stbuf->type,
51a87c55	408	stbuf->dev, &stbuf->qid,
ace51c4d EVH	409	stbuf->mode, stbuf->atime,
	410	stbuf->mtime, stbuf->length,
	411	stbuf->name, stbuf->uid,
	412	stbuf->gid, stbuf->muid,
	413	stbuf->extension, stbuf->n_uid,
	414	stbuf->n_gid, stbuf->n_muid);
	415	} break;
	416	case 'D':{
	417	int32_t count = va_arg(ap, int32_t);
	418	const void data = va_arg(ap, const void );
	419
	420	errcode =
	421	p9pdu_writef(pdu, optional, "d", count);
	422	if (!errcode && pdu_write(pdu, data, count))
	423	errcode = -EFAULT;
	424	}
	425	break;
51a87c55 EVH	426	case 'U':{
	427	int32_t count = va_arg(ap, int32_t);
	428	const char __user *udata =
	429	va_arg(ap, const void *);
	430	errcode =
	431	p9pdu_writef(pdu, optional, "d", count);
	432	if (!errcode && pdu_write_u(pdu, udata, count))
	433	errcode = -EFAULT;
	434	}
	435	break;
ace51c4d EVH	436	case 'T':{
	437	int16_t nwname = va_arg(ap, int);
	438	const char wnames = va_arg(ap, const char );
	439
	440	errcode =
	441	p9pdu_writef(pdu, optional, "w", nwname);
	442	if (!errcode) {
	443	int i;
	444
	445	for (i = 0; i < nwname; i++) {
	446	errcode =
	447	p9pdu_writef(pdu, optional,
	448	"s",
	449	wnames[i]);
	450	if (errcode)
	451	break;
	452	}
	453	}
	454	}
	455	break;
	456	case 'R':{
	457	int16_t nwqid = va_arg(ap, int);
	458	struct p9_qid *wqids =
	459	va_arg(ap, struct p9_qid *);
	460
	461	errcode =
	462	p9pdu_writef(pdu, optional, "w", nwqid);
	463	if (!errcode) {
	464	int i;
	465
	466	for (i = 0; i < nwqid; i++) {
	467	errcode =
	468	p9pdu_writef(pdu, optional,
	469	"Q",
	470	&wqids[i]);
	471	if (errcode)
	472	break;
	473	}
	474	}
	475	}
	476	break;
	477	case '?':
	478	if (!optional)
	479	return 0;
	480	break;
	481	default:
	482	BUG();
	483	break;
	484	}
	485
	486	if (errcode)
	487	break;
	488	}
	489
	490	return errcode;
	491	}
	492
	493	int p9pdu_readf(struct p9_fcall pdu, int optional, const char fmt, ...)
	494	{
	495	va_list ap;
	496	int ret;
	497
	498	va_start(ap, fmt);
	499	ret = p9pdu_vreadf(pdu, optional, fmt, ap);
500	va_end(ap);
501
502	return ret;
503	}
504
505	static int
506	p9pdu_writef(struct p9_fcall pdu, int optional, const char fmt, ...)
507	{
508	va_list ap;
509	int ret;
510
511	va_start(ap, fmt);
512	ret = p9pdu_vwritef(pdu, optional, fmt, ap);
513	va_end(ap);
514
515	return ret;
516	}
51a87c55	517
02da398b EVH	518	int p9stat_read(char buf, int len, struct p9_wstat st, int dotu)
	519	{
	520	struct p9_fcall fake_pdu;
e7f4b8f1	521	int ret;
02da398b EVH	522
	523	fake_pdu.size = len;
	524	fake_pdu.capacity = len;
	525	fake_pdu.sdata = buf;
	526	fake_pdu.offset = 0;
	527
e7f4b8f1 EVH	528	ret = p9pdu_readf(&fake_pdu, dotu, "S", st);
	529	if (ret) {
	530	P9_DPRINTK(P9_DEBUG_9P, "<<< p9stat_read failed: %d\n", ret);
	531	p9pdu_dump(1, &fake_pdu);
	532	}
	533
	534	return ret;
02da398b EVH	535	}
	536	EXPORT_SYMBOL(p9stat_read);
	537
51a87c55 EVH	538	int p9pdu_prepare(struct p9_fcall *pdu, int16_t tag, int8_t type)
	539	{
	540	return p9pdu_writef(pdu, 0, "dbw", 0, type, tag);
	541	}
	542
	543	int p9pdu_finalize(struct p9_fcall *pdu)
	544	{
	545	int size = pdu->size;
	546	int err;
	547
	548	pdu->size = 0;
	549	err = p9pdu_writef(pdu, 0, "d", size);
	550	pdu->size = size;
	551
0b15a3a5	552	#ifdef CONFIG_NET_9P_DEBUG
e7f4b8f1	553	if ((p9_debug_level & P9_DEBUG_PKT) == P9_DEBUG_PKT)
51a87c55	554	p9pdu_dump(0, pdu);
0b15a3a5	555	#endif
51a87c55	556
e7f4b8f1 EVH	557	P9_DPRINTK(P9_DEBUG_9P, ">>> size=%d type: %d tag: %d\n", pdu->size,
	558	pdu->id, pdu->tag);
	559
51a87c55 EVH	560	return err;
	561	}
	562
	563	void p9pdu_reset(struct p9_fcall *pdu)
	564	{
	565	pdu->offset = 0;
	566	pdu->size = 0;
	567	}