[linux.git] / net / 9p / protocol.c

/*
 * net/9p/protocol.c
 *
 * 9P Protocol Support Code
 *
 *  Copyright (C) 2008 by Eric Van Hensbergen <[email protected]>
 *
 *  Base on code from Anthony Liguori <[email protected]>
 *  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/kernel.h>
#include <linux/uaccess.h>
#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/stddef.h>
#include <linux/types.h>
#include <linux/uio.h>
#include <net/9p/9p.h>
#include <net/9p/client.h>
#include "protocol.h"

#include <trace/events/9p.h>

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

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);

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, struct iov_iter *from, size_t size)
{
	size_t len = min(pdu->capacity - pdu->size, size);
	struct iov_iter i = *from;
	if (!copy_from_iter_full(&pdu->sdata[pdu->size], len, &i))
		len = 0;

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

/*
	b - int8_t
	w - int16_t
	d - int32_t
	q - int64_t
	s - string
	u - numeric uid
	g - numeric gid
	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)
	A - stat for 9p2000.L (p9_stat_dotl)
	? - if optional = 1, continue parsing
*/

static int
p9pdu_vreadf(struct p9_fcall *pdu, int proto_version, 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 *);
				__le16 le_val;
				if (pdu_read(pdu, &le_val, sizeof(le_val))) {
					errcode = -EFAULT;
					break;
				}
				*val = le16_to_cpu(le_val);
			}
			break;
		case 'd':{
				int32_t *val = va_arg(ap, int32_t *);
				__le32 le_val;
				if (pdu_read(pdu, &le_val, sizeof(le_val))) {
					errcode = -EFAULT;
					break;
				}
				*val = le32_to_cpu(le_val);
			}
			break;
		case 'q':{
				int64_t *val = va_arg(ap, int64_t *);
				__le64 le_val;
				if (pdu_read(pdu, &le_val, sizeof(le_val))) {
					errcode = -EFAULT;
					break;
				}
				*val = le64_to_cpu(le_val);
			}
			break;
		case 's':{
				char **sptr = va_arg(ap, char **);
				uint16_t len;

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

				*sptr = kmalloc(len + 1, GFP_NOFS);
				if (*sptr == NULL) {
					errcode = -EFAULT;
					break;
				}
				if (pdu_read(pdu, *sptr, len)) {
					errcode = -EFAULT;
					kfree(*sptr);
					*sptr = NULL;
				} else
					(*sptr)[len] = 0;
			}
			break;
		case 'u': {
				kuid_t *uid = va_arg(ap, kuid_t *);
				__le32 le_val;
				if (pdu_read(pdu, &le_val, sizeof(le_val))) {
					errcode = -EFAULT;
					break;
				}
				*uid = make_kuid(&init_user_ns,
						 le32_to_cpu(le_val));
			} break;
		case 'g': {
				kgid_t *gid = va_arg(ap, kgid_t *);
				__le32 le_val;
				if (pdu_read(pdu, &le_val, sizeof(le_val))) {
					errcode = -EFAULT;
					break;
				}
				*gid = make_kgid(&init_user_ns,
						 le32_to_cpu(le_val));
			} break;
		case 'Q':{
				struct p9_qid *qid =
				    va_arg(ap, struct p9_qid *);

				errcode = p9pdu_readf(pdu, proto_version, "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_muid = INVALID_UID;
				stbuf->n_gid = INVALID_GID;

				errcode =
				    p9pdu_readf(pdu, proto_version,
						"wwdQdddqssss?sugu",
						&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':{
				uint32_t *count = va_arg(ap, uint32_t *);
				void **data = va_arg(ap, void **);

				errcode =
				    p9pdu_readf(pdu, proto_version, "d", count);
				if (!errcode) {
					*count =
					    min_t(uint32_t, *count,
						  pdu->size - pdu->offset);
					*data = &pdu->sdata[pdu->offset];
				}
			}
			break;
		case 'T':{
				uint16_t *nwname = va_arg(ap, uint16_t *);
				char ***wnames = va_arg(ap, char ***);

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

				if (!errcode) {
					int i;

					for (i = 0; i < *nwname; i++) {
						errcode =
						    p9pdu_readf(pdu,
								proto_version,
								"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':{
				uint16_t *nwqid = va_arg(ap, uint16_t *);
				struct p9_qid **wqids =
				    va_arg(ap, struct p9_qid **);

				*wqids = NULL;

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

				if (!errcode) {
					int i;

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

				if (errcode) {
					kfree(*wqids);
					*wqids = NULL;
				}
			}
			break;
		case 'A': {
				struct p9_stat_dotl *stbuf =
				    va_arg(ap, struct p9_stat_dotl *);

				memset(stbuf, 0, sizeof(struct p9_stat_dotl));
				errcode =
				    p9pdu_readf(pdu, proto_version,
					"qQdugqqqqqqqqqqqqqqq",
					&stbuf->st_result_mask,
					&stbuf->qid,
					&stbuf->st_mode,
					&stbuf->st_uid, &stbuf->st_gid,
					&stbuf->st_nlink,
					&stbuf->st_rdev, &stbuf->st_size,
					&stbuf->st_blksize, &stbuf->st_blocks,
					&stbuf->st_atime_sec,
					&stbuf->st_atime_nsec,
					&stbuf->st_mtime_sec,
					&stbuf->st_mtime_nsec,
					&stbuf->st_ctime_sec,
					&stbuf->st_ctime_nsec,
					&stbuf->st_btime_sec,
					&stbuf->st_btime_nsec,
					&stbuf->st_gen,
					&stbuf->st_data_version);
			}
			break;
		case '?':
			if ((proto_version != p9_proto_2000u) &&
				(proto_version != p9_proto_2000L))
				return 0;
			break;
		default:
			BUG();
			break;
		}

		if (errcode)
			break;
	}

	return errcode;
}

int
p9pdu_vwritef(struct p9_fcall *pdu, int proto_version, 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':{
				__le16 val = cpu_to_le16(va_arg(ap, int));
				if (pdu_write(pdu, &val, sizeof(val)))
					errcode = -EFAULT;
			}
			break;
		case 'd':{
				__le32 val = cpu_to_le32(va_arg(ap, int32_t));
				if (pdu_write(pdu, &val, sizeof(val)))
					errcode = -EFAULT;
			}
			break;
		case 'q':{
				__le64 val = cpu_to_le64(va_arg(ap, int64_t));
				if (pdu_write(pdu, &val, sizeof(val)))
					errcode = -EFAULT;
			}
			break;
		case 's':{
				const char *sptr = va_arg(ap, const char *);
				uint16_t len = 0;
				if (sptr)
					len = min_t(size_t, strlen(sptr),
								USHRT_MAX);

				errcode = p9pdu_writef(pdu, proto_version,
								"w", len);
				if (!errcode && pdu_write(pdu, sptr, len))
					errcode = -EFAULT;
			}
			break;
		case 'u': {
				kuid_t uid = va_arg(ap, kuid_t);
				__le32 val = cpu_to_le32(
						from_kuid(&init_user_ns, uid));
				if (pdu_write(pdu, &val, sizeof(val)))
					errcode = -EFAULT;
			} break;
		case 'g': {
				kgid_t gid = va_arg(ap, kgid_t);
				__le32 val = cpu_to_le32(
						from_kgid(&init_user_ns, gid));
				if (pdu_write(pdu, &val, sizeof(val)))
					errcode = -EFAULT;
			} break;
		case 'Q':{
				const struct p9_qid *qid =
				    va_arg(ap, const struct p9_qid *);
				errcode =
				    p9pdu_writef(pdu, proto_version, "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, proto_version,
						 "wwdQdddqssss?sugu",
						 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 'V':{
				uint32_t count = va_arg(ap, uint32_t);
				struct iov_iter *from =
						va_arg(ap, struct iov_iter *);
				errcode = p9pdu_writef(pdu, proto_version, "d",
									count);
				if (!errcode && pdu_write_u(pdu, from, count))
					errcode = -EFAULT;
			}
			break;
		case 'T':{
				uint16_t nwname = va_arg(ap, int);
				const char **wnames = va_arg(ap, const char **);

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

					for (i = 0; i < nwname; i++) {
						errcode =
						    p9pdu_writef(pdu,
								proto_version,
								 "s",
								 wnames[i]);
						if (errcode)
							break;
					}
				}
			}
			break;
		case 'R':{
				uint16_t nwqid = va_arg(ap, int);
				struct p9_qid *wqids =
				    va_arg(ap, struct p9_qid *);

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

					for (i = 0; i < nwqid; i++) {
						errcode =
						    p9pdu_writef(pdu,
								proto_version,
								 "Q",
								 &wqids[i]);
						if (errcode)
							break;
					}
				}
			}
			break;
		case 'I':{
				struct p9_iattr_dotl *p9attr = va_arg(ap,
							struct p9_iattr_dotl *);

				errcode = p9pdu_writef(pdu, proto_version,
							"ddugqqqqq",
							p9attr->valid,
							p9attr->mode,
							p9attr->uid,
							p9attr->gid,
							p9attr->size,
							p9attr->atime_sec,
							p9attr->atime_nsec,
							p9attr->mtime_sec,
							p9attr->mtime_nsec);
			}
			break;
		case '?':
			if ((proto_version != p9_proto_2000u) &&
				(proto_version != p9_proto_2000L))
				return 0;
			break;
		default:
			BUG();
			break;
		}

		if (errcode)
			break;
	}

	return errcode;
}

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

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

	return ret;
}

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

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

	return ret;
}

int p9stat_read(struct p9_client *clnt, char *buf, int len, struct p9_wstat *st)
{
	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, clnt->proto_version, "S", st);
	if (ret) {
		p9_debug(P9_DEBUG_9P, "<<< p9stat_read failed: %d\n", ret);
		trace_9p_protocol_dump(clnt, &fake_pdu);
	}

	return ret;
}
EXPORT_SYMBOL(p9stat_read);

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

int p9pdu_finalize(struct p9_client *clnt, struct p9_fcall *pdu)
{
	int size = pdu->size;
	int err;

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

	trace_9p_protocol_dump(clnt, pdu);
	p9_debug(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;
}

int p9dirent_read(struct p9_client *clnt, char *buf, int len,
		  struct p9_dirent *dirent)
{
	struct p9_fcall fake_pdu;
	int ret;
	char *nameptr;

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

	ret = p9pdu_readf(&fake_pdu, clnt->proto_version, "Qqbs", &dirent->qid,
			  &dirent->d_off, &dirent->d_type, &nameptr);
	if (ret) {
		p9_debug(P9_DEBUG_9P, "<<< p9dirent_read failed: %d\n", ret);
		trace_9p_protocol_dump(clnt, &fake_pdu);
		goto out;
	}

	strcpy(dirent->d_name, nameptr);
	kfree(nameptr);

out:
	return fake_pdu.offset;
}
EXPORT_SYMBOL(p9dirent_read);
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 <[email protected]>
	7	*
	8	* Base on code from Anthony Liguori <[email protected]>
	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>
01b0c5cf	30	#include <linux/kernel.h>
51a87c55	31	#include <linux/uaccess.h>
5a0e3ad6	32	#include <linux/slab.h>
e7f4b8f1	33	#include <linux/sched.h>
01b0c5cf	34	#include <linux/stddef.h>
beeebc92	35	#include <linux/types.h>
4f3b35c1	36	#include <linux/uio.h>
ace51c4d EVH	37	#include <net/9p/9p.h>
	38	#include <net/9p/client.h>
	39	#include "protocol.h"
	40
348b5901 AK	41	#include <trace/events/9p.h>
348b5901 AK	42
ace51c4d	43	static int
342fee1d	44	p9pdu_writef(struct p9_fcall pdu, int proto_version, const char fmt, ...);
ace51c4d EVH	45
	46	void p9stat_free(struct p9_wstat *stbuf)
	47	{
	48	kfree(stbuf->name);
	49	kfree(stbuf->uid);
	50	kfree(stbuf->gid);
	51	kfree(stbuf->muid);
	52	kfree(stbuf->extension);
	53	}
	54	EXPORT_SYMBOL(p9stat_free);
	55
abfa034e	56	size_t pdu_read(struct p9_fcall pdu, void data, size_t size)
ace51c4d	57	{
01b0c5cf	58	size_t len = min(pdu->size - pdu->offset, size);
ace51c4d EVH	59	memcpy(data, &pdu->sdata[pdu->offset], len);
	60	pdu->offset += len;
	61	return size - len;
	62	}
	63
	64	static size_t pdu_write(struct p9_fcall pdu, const void data, size_t size)
	65	{
01b0c5cf	66	size_t len = min(pdu->capacity - pdu->size, size);
ace51c4d EVH	67	memcpy(&pdu->sdata[pdu->size], data, len);
	68	pdu->size += len;
	69	return size - len;
	70	}
	71
51a87c55	72	static size_t
4f3b35c1	73	pdu_write_u(struct p9_fcall pdu, struct iov_iter from, size_t size)
51a87c55	74	{
01b0c5cf	75	size_t len = min(pdu->capacity - pdu->size, size);
4f3b35c1	76	struct iov_iter i = *from;
1c512a7c	77	if (!copy_from_iter_full(&pdu->sdata[pdu->size], len, &i))
7b3bb3fe	78	len = 0;
51a87c55 EVH	79
	80	pdu->size += len;
	81	return size - len;
	82	}
	83
ace51c4d EVH	84	/*
	85	b - int8_t
	86	w - int16_t
	87	d - int32_t
	88	q - int64_t
	89	s - string
97fc8b1e EB	90	u - numeric uid
97fc8b1e EB	91	g - numeric gid
ace51c4d EVH	92	S - stat
	93	Q - qid
	94	D - data blob (int32_t size followed by void *, results are not freed)
	95	T - array of strings (int16_t count, followed by strings)
	96	R - array of qids (int16_t count, followed by qids)
f0853122	97	A - stat for 9p2000.L (p9_stat_dotl)
ace51c4d EVH	98	? - if optional = 1, continue parsing
	99	*/
	100
	101	static int
342fee1d SK	102	p9pdu_vreadf(struct p9_fcall pdu, int proto_version, const char fmt,
342fee1d SK	103	va_list ap)
ace51c4d EVH	104	{
	105	const char *ptr;
	106	int errcode = 0;
	107
	108	for (ptr = fmt; *ptr; ptr++) {
	109	switch (*ptr) {
	110	case 'b':{
	111	int8_t val = va_arg(ap, int8_t );
	112	if (pdu_read(pdu, val, sizeof(*val))) {
	113	errcode = -EFAULT;
	114	break;
	115	}
	116	}
	117	break;
	118	case 'w':{
	119	int16_t val = va_arg(ap, int16_t );
beeebc92 EVH	120	__le16 le_val;
beeebc92 EVH	121	if (pdu_read(pdu, &le_val, sizeof(le_val))) {
ace51c4d EVH	122	errcode = -EFAULT;
	123	break;
	124	}
beeebc92	125	*val = le16_to_cpu(le_val);
ace51c4d EVH	126	}
	127	break;
	128	case 'd':{
	129	int32_t val = va_arg(ap, int32_t );
beeebc92 EVH	130	__le32 le_val;
beeebc92 EVH	131	if (pdu_read(pdu, &le_val, sizeof(le_val))) {
ace51c4d EVH	132	errcode = -EFAULT;
	133	break;
	134	}
beeebc92	135	*val = le32_to_cpu(le_val);
ace51c4d EVH	136	}
	137	break;
	138	case 'q':{
	139	int64_t val = va_arg(ap, int64_t );
beeebc92 EVH	140	__le64 le_val;
beeebc92 EVH	141	if (pdu_read(pdu, &le_val, sizeof(le_val))) {
ace51c4d EVH	142	errcode = -EFAULT;
	143	break;
	144	}
beeebc92	145	*val = le64_to_cpu(le_val);
ace51c4d EVH	146	}
	147	break;
	148	case 's':{
e45c5405	149	char sptr = va_arg(ap, char );
219fd58b	150	uint16_t len;
ace51c4d	151
342fee1d SK	152	errcode = p9pdu_readf(pdu, proto_version,
342fee1d SK	153	"w", &len);
ace51c4d EVH	154	if (errcode)
	155	break;
	156
eeff66ef	157	*sptr = kmalloc(len + 1, GFP_NOFS);
e45c5405	158	if (*sptr == NULL) {
ace51c4d EVH	159	errcode = -EFAULT;
	160	break;
	161	}
219fd58b	162	if (pdu_read(pdu, *sptr, len)) {
ace51c4d	163	errcode = -EFAULT;
e45c5405 EVH	164	kfree(*sptr);
e45c5405 EVH	165	*sptr = NULL;
ace51c4d	166	} else
219fd58b	167	(*sptr)[len] = 0;
ace51c4d EVH	168	}
ace51c4d EVH	169	break;
97fc8b1e EB	170	case 'u': {
	171	kuid_t uid = va_arg(ap, kuid_t );
	172	__le32 le_val;
	173	if (pdu_read(pdu, &le_val, sizeof(le_val))) {
	174	errcode = -EFAULT;
	175	break;
	176	}
	177	*uid = make_kuid(&init_user_ns,
	178	le32_to_cpu(le_val));
	179	} break;
	180	case 'g': {
	181	kgid_t gid = va_arg(ap, kgid_t );
	182	__le32 le_val;
	183	if (pdu_read(pdu, &le_val, sizeof(le_val))) {
	184	errcode = -EFAULT;
	185	break;
	186	}
	187	*gid = make_kgid(&init_user_ns,
	188	le32_to_cpu(le_val));
	189	} break;
ace51c4d EVH	190	case 'Q':{
	191	struct p9_qid *qid =
	192	va_arg(ap, struct p9_qid *);
	193
342fee1d	194	errcode = p9pdu_readf(pdu, proto_version, "bdq",
ace51c4d EVH	195	&qid->type, &qid->version,
	196	&qid->path);
	197	}
	198	break;
	199	case 'S':{
	200	struct p9_wstat *stbuf =
	201	va_arg(ap, struct p9_wstat *);
	202
f0a0ac2e	203	memset(stbuf, 0, sizeof(struct p9_wstat));
447c5094 EB	204	stbuf->n_uid = stbuf->n_muid = INVALID_UID;
	205	stbuf->n_gid = INVALID_GID;
	206
ace51c4d	207	errcode =
342fee1d	208	p9pdu_readf(pdu, proto_version,
447c5094	209	"wwdQdddqssss?sugu",
ace51c4d EVH	210	&stbuf->size, &stbuf->type,
	211	&stbuf->dev, &stbuf->qid,
	212	&stbuf->mode, &stbuf->atime,
	213	&stbuf->mtime, &stbuf->length,
	214	&stbuf->name, &stbuf->uid,
	215	&stbuf->gid, &stbuf->muid,
	216	&stbuf->extension,
	217	&stbuf->n_uid, &stbuf->n_gid,
	218	&stbuf->n_muid);
	219	if (errcode)
	220	p9stat_free(stbuf);
	221	}
	222	break;
	223	case 'D':{
219fd58b	224	uint32_t count = va_arg(ap, uint32_t );
ace51c4d EVH	225	void data = va_arg(ap, void );
	226
	227	errcode =
342fee1d	228	p9pdu_readf(pdu, proto_version, "d", count);
ace51c4d EVH	229	if (!errcode) {
ace51c4d EVH	230	*count =
219fd58b	231	min_t(uint32_t, *count,
01b0c5cf	232	pdu->size - pdu->offset);
ace51c4d EVH	233	*data = &pdu->sdata[pdu->offset];
	234	}
	235	}
	236	break;
	237	case 'T':{
b76225e2	238	uint16_t nwname = va_arg(ap, uint16_t );
ace51c4d EVH	239	char *wnames = va_arg(ap, char *);
ace51c4d EVH	240
342fee1d SK	241	errcode = p9pdu_readf(pdu, proto_version,
342fee1d SK	242	"w", nwname);
ace51c4d EVH	243	if (!errcode) {
	244	*wnames =
	245	kmalloc(sizeof(char ) *nwname,
eeff66ef	246	GFP_NOFS);
ace51c4d EVH	247	if (!*wnames)
	248	errcode = -ENOMEM;
	249	}
	250
	251	if (!errcode) {
	252	int i;
	253
	254	for (i = 0; i < *nwname; i++) {
	255	errcode =
342fee1d SK	256	p9pdu_readf(pdu,
342fee1d SK	257	proto_version,
ace51c4d EVH	258	"s",
	259	&(*wnames)[i]);
	260	if (errcode)
	261	break;
	262	}
	263	}
	264
	265	if (errcode) {
	266	if (*wnames) {
	267	int i;
	268
	269	for (i = 0; i < *nwname; i++)
	270	kfree((*wnames)[i]);
	271	}
	272	kfree(*wnames);
	273	*wnames = NULL;
	274	}
	275	}
	276	break;
	277	case 'R':{
6250a8ba	278	uint16_t nwqid = va_arg(ap, uint16_t );
ace51c4d EVH	279	struct p9_qid **wqids =
	280	va_arg(ap, struct p9_qid **);
	281
	282	*wqids = NULL;
	283
	284	errcode =
342fee1d	285	p9pdu_readf(pdu, proto_version, "w", nwqid);
ace51c4d EVH	286	if (!errcode) {
	287	*wqids =
	288	kmalloc(nwqid
	289	sizeof(struct p9_qid),
eeff66ef	290	GFP_NOFS);
ace51c4d EVH	291	if (*wqids == NULL)
	292	errcode = -ENOMEM;
	293	}
	294
	295	if (!errcode) {
	296	int i;
	297
	298	for (i = 0; i < *nwqid; i++) {
	299	errcode =
342fee1d SK	300	p9pdu_readf(pdu,
342fee1d SK	301	proto_version,
ace51c4d EVH	302	"Q",
	303	&(*wqids)[i]);
	304	if (errcode)
	305	break;
	306	}
	307	}
	308
	309	if (errcode) {
	310	kfree(*wqids);
	311	*wqids = NULL;
	312	}
	313	}
	314	break;
f0853122 SK	315	case 'A': {
	316	struct p9_stat_dotl *stbuf =
	317	va_arg(ap, struct p9_stat_dotl *);
	318
	319	memset(stbuf, 0, sizeof(struct p9_stat_dotl));
	320	errcode =
	321	p9pdu_readf(pdu, proto_version,
447c5094	322	"qQdugqqqqqqqqqqqqqqq",
f0853122 SK	323	&stbuf->st_result_mask,
	324	&stbuf->qid,
	325	&stbuf->st_mode,
	326	&stbuf->st_uid, &stbuf->st_gid,
	327	&stbuf->st_nlink,
	328	&stbuf->st_rdev, &stbuf->st_size,
	329	&stbuf->st_blksize, &stbuf->st_blocks,
	330	&stbuf->st_atime_sec,
	331	&stbuf->st_atime_nsec,
	332	&stbuf->st_mtime_sec,
	333	&stbuf->st_mtime_nsec,
	334	&stbuf->st_ctime_sec,
	335	&stbuf->st_ctime_nsec,
	336	&stbuf->st_btime_sec,
	337	&stbuf->st_btime_nsec,
	338	&stbuf->st_gen,
	339	&stbuf->st_data_version);
	340	}
	341	break;
ace51c4d	342	case '?':
c56e4acf SK	343	if ((proto_version != p9_proto_2000u) &&
c56e4acf SK	344	(proto_version != p9_proto_2000L))
ace51c4d EVH	345	return 0;
	346	break;
	347	default:
	348	BUG();
	349	break;
	350	}
	351
	352	if (errcode)
	353	break;
	354	}
	355
	356	return errcode;
	357	}
	358
	359	int
342fee1d SK	360	p9pdu_vwritef(struct p9_fcall pdu, int proto_version, const char fmt,
342fee1d SK	361	va_list ap)
ace51c4d EVH	362	{
	363	const char *ptr;
	364	int errcode = 0;
	365
	366	for (ptr = fmt; *ptr; ptr++) {
	367	switch (*ptr) {
	368	case 'b':{
	369	int8_t val = va_arg(ap, int);
	370	if (pdu_write(pdu, &val, sizeof(val)))
	371	errcode = -EFAULT;
	372	}
	373	break;
	374	case 'w':{
beeebc92	375	__le16 val = cpu_to_le16(va_arg(ap, int));
ace51c4d EVH	376	if (pdu_write(pdu, &val, sizeof(val)))
	377	errcode = -EFAULT;
	378	}
	379	break;
	380	case 'd':{
beeebc92	381	__le32 val = cpu_to_le32(va_arg(ap, int32_t));
ace51c4d EVH	382	if (pdu_write(pdu, &val, sizeof(val)))
	383	errcode = -EFAULT;
	384	}
	385	break;
	386	case 'q':{
beeebc92	387	__le64 val = cpu_to_le64(va_arg(ap, int64_t));
ace51c4d EVH	388	if (pdu_write(pdu, &val, sizeof(val)))
	389	errcode = -EFAULT;
	390	}
	391	break;
	392	case 's':{
e45c5405	393	const char sptr = va_arg(ap, const char );
219fd58b	394	uint16_t len = 0;
e45c5405	395	if (sptr)
d31bb4f0	396	len = min_t(size_t, strlen(sptr),
219fd58b	397	USHRT_MAX);
ace51c4d	398
342fee1d SK	399	errcode = p9pdu_writef(pdu, proto_version,
342fee1d SK	400	"w", len);
e45c5405	401	if (!errcode && pdu_write(pdu, sptr, len))
ace51c4d EVH	402	errcode = -EFAULT;
	403	}
	404	break;
97fc8b1e EB	405	case 'u': {
	406	kuid_t uid = va_arg(ap, kuid_t);
	407	__le32 val = cpu_to_le32(
	408	from_kuid(&init_user_ns, uid));
	409	if (pdu_write(pdu, &val, sizeof(val)))
	410	errcode = -EFAULT;
	411	} break;
	412	case 'g': {
	413	kgid_t gid = va_arg(ap, kgid_t);
	414	__le32 val = cpu_to_le32(
	415	from_kgid(&init_user_ns, gid));
	416	if (pdu_write(pdu, &val, sizeof(val)))
	417	errcode = -EFAULT;
	418	} break;
ace51c4d EVH	419	case 'Q':{
	420	const struct p9_qid *qid =
	421	va_arg(ap, const struct p9_qid *);
	422	errcode =
342fee1d	423	p9pdu_writef(pdu, proto_version, "bdq",
ace51c4d EVH	424	qid->type, qid->version,
	425	qid->path);
	426	} break;
	427	case 'S':{
	428	const struct p9_wstat *stbuf =
	429	va_arg(ap, const struct p9_wstat *);
	430	errcode =
342fee1d	431	p9pdu_writef(pdu, proto_version,
447c5094	432	"wwdQdddqssss?sugu",
ace51c4d	433	stbuf->size, stbuf->type,
51a87c55	434	stbuf->dev, &stbuf->qid,
ace51c4d EVH	435	stbuf->mode, stbuf->atime,
	436	stbuf->mtime, stbuf->length,
	437	stbuf->name, stbuf->uid,
	438	stbuf->gid, stbuf->muid,
	439	stbuf->extension, stbuf->n_uid,
	440	stbuf->n_gid, stbuf->n_muid);
	441	} break;
4f3b35c1	442	case 'V':{
6250a8ba	443	uint32_t count = va_arg(ap, uint32_t);
4f3b35c1 AV	444	struct iov_iter *from =
4f3b35c1 AV	445	va_arg(ap, struct iov_iter *);
342fee1d SK	446	errcode = p9pdu_writef(pdu, proto_version, "d",
342fee1d SK	447	count);
4f3b35c1	448	if (!errcode && pdu_write_u(pdu, from, count))
51a87c55 EVH	449	errcode = -EFAULT;
	450	}
	451	break;
ace51c4d	452	case 'T':{
b76225e2	453	uint16_t nwname = va_arg(ap, int);
ace51c4d EVH	454	const char wnames = va_arg(ap, const char );
ace51c4d EVH	455
342fee1d SK	456	errcode = p9pdu_writef(pdu, proto_version, "w",
342fee1d SK	457	nwname);
ace51c4d EVH	458	if (!errcode) {
	459	int i;
	460
	461	for (i = 0; i < nwname; i++) {
	462	errcode =
342fee1d SK	463	p9pdu_writef(pdu,
342fee1d SK	464	proto_version,
ace51c4d EVH	465	"s",
	466	wnames[i]);
	467	if (errcode)
	468	break;
	469	}
	470	}
	471	}
	472	break;
	473	case 'R':{
6250a8ba	474	uint16_t nwqid = va_arg(ap, int);
ace51c4d EVH	475	struct p9_qid *wqids =
	476	va_arg(ap, struct p9_qid *);
	477
342fee1d SK	478	errcode = p9pdu_writef(pdu, proto_version, "w",
342fee1d SK	479	nwqid);
ace51c4d EVH	480	if (!errcode) {
	481	int i;
	482
	483	for (i = 0; i < nwqid; i++) {
	484	errcode =
342fee1d SK	485	p9pdu_writef(pdu,
342fee1d SK	486	proto_version,
ace51c4d EVH	487	"Q",
	488	&wqids[i]);
	489	if (errcode)
	490	break;
	491	}
	492	}
	493	}
	494	break;
87d7845a SK	495	case 'I':{
	496	struct p9_iattr_dotl *p9attr = va_arg(ap,
	497	struct p9_iattr_dotl *);
	498
	499	errcode = p9pdu_writef(pdu, proto_version,
447c5094	500	"ddugqqqqq",
87d7845a SK	501	p9attr->valid,
	502	p9attr->mode,
	503	p9attr->uid,
	504	p9attr->gid,
	505	p9attr->size,
	506	p9attr->atime_sec,
	507	p9attr->atime_nsec,
	508	p9attr->mtime_sec,
	509	p9attr->mtime_nsec);
	510	}
	511	break;
ace51c4d	512	case '?':
c56e4acf SK	513	if ((proto_version != p9_proto_2000u) &&
c56e4acf SK	514	(proto_version != p9_proto_2000L))
ace51c4d EVH	515	return 0;
	516	break;
	517	default:
	518	BUG();
	519	break;
	520	}
	521
	522	if (errcode)
	523	break;
	524	}
	525
	526	return errcode;
	527	}
	528
342fee1d	529	int p9pdu_readf(struct p9_fcall pdu, int proto_version, const char fmt, ...)
ace51c4d EVH	530	{
	531	va_list ap;
	532	int ret;
	533
	534	va_start(ap, fmt);
342fee1d	535	ret = p9pdu_vreadf(pdu, proto_version, fmt, ap);
ace51c4d EVH	536	va_end(ap);
	537
	538	return ret;
	539	}
	540
	541	static int
342fee1d	542	p9pdu_writef(struct p9_fcall pdu, int proto_version, const char fmt, ...)
ace51c4d EVH	543	{
	544	va_list ap;
	545	int ret;
	546
	547	va_start(ap, fmt);
342fee1d	548	ret = p9pdu_vwritef(pdu, proto_version, fmt, ap);
ace51c4d EVH	549	va_end(ap);
	550
	551	return ret;
	552	}
51a87c55	553
348b5901	554	int p9stat_read(struct p9_client clnt, char buf, int len, struct p9_wstat *st)
02da398b EVH	555	{
02da398b EVH	556	struct p9_fcall fake_pdu;
e7f4b8f1	557	int ret;
02da398b EVH	558
	559	fake_pdu.size = len;
	560	fake_pdu.capacity = len;
	561	fake_pdu.sdata = buf;
	562	fake_pdu.offset = 0;
	563
348b5901	564	ret = p9pdu_readf(&fake_pdu, clnt->proto_version, "S", st);
e7f4b8f1	565	if (ret) {
5d385153	566	p9_debug(P9_DEBUG_9P, "<<< p9stat_read failed: %d\n", ret);
348b5901	567	trace_9p_protocol_dump(clnt, &fake_pdu);
e7f4b8f1 EVH	568	}
	569
	570	return ret;
02da398b EVH	571	}
	572	EXPORT_SYMBOL(p9stat_read);
	573
51a87c55 EVH	574	int p9pdu_prepare(struct p9_fcall *pdu, int16_t tag, int8_t type)
51a87c55 EVH	575	{
9bb6c10a	576	pdu->id = type;
51a87c55 EVH	577	return p9pdu_writef(pdu, 0, "dbw", 0, type, tag);
	578	}
	579
348b5901	580	int p9pdu_finalize(struct p9_client clnt, struct p9_fcall pdu)
51a87c55 EVH	581	{
	582	int size = pdu->size;
	583	int err;
	584
	585	pdu->size = 0;
	586	err = p9pdu_writef(pdu, 0, "d", size);
	587	pdu->size = size;
	588
348b5901	589	trace_9p_protocol_dump(clnt, pdu);
5d385153 JP	590	p9_debug(P9_DEBUG_9P, ">>> size=%d type: %d tag: %d\n",
5d385153 JP	591	pdu->size, pdu->id, pdu->tag);
e7f4b8f1	592
51a87c55 EVH	593	return err;
	594	}
	595
	596	void p9pdu_reset(struct p9_fcall *pdu)
	597	{
	598	pdu->offset = 0;
	599	pdu->size = 0;
	600	}
7751bdb3	601
348b5901 AK	602	int p9dirent_read(struct p9_client clnt, char buf, int len,
348b5901 AK	603	struct p9_dirent *dirent)
7751bdb3 SK	604	{
	605	struct p9_fcall fake_pdu;
	606	int ret;
	607	char *nameptr;
	608
	609	fake_pdu.size = len;
	610	fake_pdu.capacity = len;
	611	fake_pdu.sdata = buf;
	612	fake_pdu.offset = 0;
	613
348b5901 AK	614	ret = p9pdu_readf(&fake_pdu, clnt->proto_version, "Qqbs", &dirent->qid,
348b5901 AK	615	&dirent->d_off, &dirent->d_type, &nameptr);
7751bdb3	616	if (ret) {
5d385153	617	p9_debug(P9_DEBUG_9P, "<<< p9dirent_read failed: %d\n", ret);
348b5901	618	trace_9p_protocol_dump(clnt, &fake_pdu);
7751bdb3 SK	619	goto out;
	620	}
	621
	622	strcpy(dirent->d_name, nameptr);
1b0bcbcf	623	kfree(nameptr);
7751bdb3 SK	624
	625	out:
	626	return fake_pdu.offset;
	627	}
	628	EXPORT_SYMBOL(p9dirent_read);