[mirror_ubuntu-jammy-kernel.git] / net / 9p / protocol.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * 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.
 */

#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);
	stbuf->name = NULL;
	kfree(stbuf->uid);
	stbuf->uid = NULL;
	kfree(stbuf->gid);
	stbuf->gid = NULL;
	kfree(stbuf->muid);
	stbuf->muid = NULL;
	kfree(stbuf->extension);
	stbuf->extension = NULL;
}
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 = -ENOMEM;
					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_array(*nwname,
							  sizeof(char *),
							  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_array(*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;
	}

	return fake_pdu.offset;
}
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);
		return ret;
	}

	ret = strscpy(dirent->d_name, nameptr, sizeof(dirent->d_name));
	if (ret < 0) {
		p9_debug(P9_DEBUG_ERROR,
			 "On the wire dirent name too long: %s\n",
			 nameptr);
		kfree(nameptr);
		return ret;
	}
	kfree(nameptr);

	return fake_pdu.offset;
}
EXPORT_SYMBOL(p9dirent_read);
Commit	Line	Data
1f327613	1	// SPDX-License-Identifier: GPL-2.0-only
ace51c4d EVH	2	/*
	3	* net/9p/protocol.c
	4	*
	5	* 9P Protocol Support Code
	6	*
	7	* Copyright (C) 2008 by Eric Van Hensbergen <ericvh@gmail.com>
	8	*
	9	* Base on code from Anthony Liguori <aliguori@us.ibm.com>
	10	* Copyright (C) 2008 by IBM, Corp.
ace51c4d EVH	11	*/
	12
	13	#include <linux/module.h>
	14	#include <linux/errno.h>
01b0c5cf	15	#include <linux/kernel.h>
51a87c55	16	#include <linux/uaccess.h>
5a0e3ad6	17	#include <linux/slab.h>
e7f4b8f1	18	#include <linux/sched.h>
01b0c5cf	19	#include <linux/stddef.h>
beeebc92	20	#include <linux/types.h>
4f3b35c1	21	#include <linux/uio.h>
ace51c4d EVH	22	#include <net/9p/9p.h>
	23	#include <net/9p/client.h>
	24	#include "protocol.h"
	25
348b5901 AK	26	#include <trace/events/9p.h>
348b5901 AK	27
ace51c4d	28	static int
342fee1d	29	p9pdu_writef(struct p9_fcall pdu, int proto_version, const char fmt, ...);
ace51c4d EVH	30
	31	void p9stat_free(struct p9_wstat *stbuf)
	32	{
	33	kfree(stbuf->name);
62e39417	34	stbuf->name = NULL;
ace51c4d	35	kfree(stbuf->uid);
62e39417	36	stbuf->uid = NULL;
ace51c4d	37	kfree(stbuf->gid);
62e39417	38	stbuf->gid = NULL;
ace51c4d	39	kfree(stbuf->muid);
62e39417	40	stbuf->muid = NULL;
ace51c4d	41	kfree(stbuf->extension);
62e39417	42	stbuf->extension = NULL;
ace51c4d EVH	43	}
	44	EXPORT_SYMBOL(p9stat_free);
	45
abfa034e	46	size_t pdu_read(struct p9_fcall pdu, void data, size_t size)
ace51c4d	47	{
01b0c5cf	48	size_t len = min(pdu->size - pdu->offset, size);
ace51c4d EVH	49	memcpy(data, &pdu->sdata[pdu->offset], len);
	50	pdu->offset += len;
	51	return size - len;
	52	}
	53
	54	static size_t pdu_write(struct p9_fcall pdu, const void data, size_t size)
	55	{
01b0c5cf	56	size_t len = min(pdu->capacity - pdu->size, size);
ace51c4d EVH	57	memcpy(&pdu->sdata[pdu->size], data, len);
	58	pdu->size += len;
	59	return size - len;
	60	}
	61
51a87c55	62	static size_t
4f3b35c1	63	pdu_write_u(struct p9_fcall pdu, struct iov_iter from, size_t size)
51a87c55	64	{
01b0c5cf	65	size_t len = min(pdu->capacity - pdu->size, size);
4f3b35c1	66	struct iov_iter i = *from;
1c512a7c	67	if (!copy_from_iter_full(&pdu->sdata[pdu->size], len, &i))
7b3bb3fe	68	len = 0;
51a87c55 EVH	69
	70	pdu->size += len;
	71	return size - len;
	72	}
	73
ace51c4d EVH	74	/*
	75	b - int8_t
	76	w - int16_t
	77	d - int32_t
	78	q - int64_t
	79	s - string
97fc8b1e EB	80	u - numeric uid
97fc8b1e EB	81	g - numeric gid
ace51c4d EVH	82	S - stat
	83	Q - qid
	84	D - data blob (int32_t size followed by void *, results are not freed)
	85	T - array of strings (int16_t count, followed by strings)
	86	R - array of qids (int16_t count, followed by qids)
f0853122	87	A - stat for 9p2000.L (p9_stat_dotl)
ace51c4d EVH	88	? - if optional = 1, continue parsing
	89	*/
	90
	91	static int
342fee1d SK	92	p9pdu_vreadf(struct p9_fcall pdu, int proto_version, const char fmt,
342fee1d SK	93	va_list ap)
ace51c4d EVH	94	{
	95	const char *ptr;
	96	int errcode = 0;
	97
	98	for (ptr = fmt; *ptr; ptr++) {
	99	switch (*ptr) {
	100	case 'b':{
	101	int8_t val = va_arg(ap, int8_t );
	102	if (pdu_read(pdu, val, sizeof(*val))) {
	103	errcode = -EFAULT;
	104	break;
	105	}
	106	}
	107	break;
	108	case 'w':{
	109	int16_t val = va_arg(ap, int16_t );
beeebc92 EVH	110	__le16 le_val;
beeebc92 EVH	111	if (pdu_read(pdu, &le_val, sizeof(le_val))) {
ace51c4d EVH	112	errcode = -EFAULT;
	113	break;
	114	}
beeebc92	115	*val = le16_to_cpu(le_val);
ace51c4d EVH	116	}
	117	break;
	118	case 'd':{
	119	int32_t val = va_arg(ap, int32_t );
beeebc92 EVH	120	__le32 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 = le32_to_cpu(le_val);
ace51c4d EVH	126	}
	127	break;
	128	case 'q':{
	129	int64_t val = va_arg(ap, int64_t );
beeebc92 EVH	130	__le64 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 = le64_to_cpu(le_val);
ace51c4d EVH	136	}
	137	break;
	138	case 's':{
e45c5405	139	char sptr = va_arg(ap, char );
219fd58b	140	uint16_t len;
ace51c4d	141
342fee1d SK	142	errcode = p9pdu_readf(pdu, proto_version,
342fee1d SK	143	"w", &len);
ace51c4d EVH	144	if (errcode)
	145	break;
	146
eeff66ef	147	*sptr = kmalloc(len + 1, GFP_NOFS);
e45c5405	148	if (*sptr == NULL) {
b87d1d26	149	errcode = -ENOMEM;
ace51c4d EVH	150	break;
ace51c4d EVH	151	}
219fd58b	152	if (pdu_read(pdu, *sptr, len)) {
ace51c4d	153	errcode = -EFAULT;
e45c5405 EVH	154	kfree(*sptr);
e45c5405 EVH	155	*sptr = NULL;
ace51c4d	156	} else
219fd58b	157	(*sptr)[len] = 0;
ace51c4d EVH	158	}
ace51c4d EVH	159	break;
97fc8b1e EB	160	case 'u': {
	161	kuid_t uid = va_arg(ap, kuid_t );
	162	__le32 le_val;
	163	if (pdu_read(pdu, &le_val, sizeof(le_val))) {
	164	errcode = -EFAULT;
	165	break;
	166	}
	167	*uid = make_kuid(&init_user_ns,
	168	le32_to_cpu(le_val));
	169	} break;
	170	case 'g': {
	171	kgid_t gid = va_arg(ap, kgid_t );
	172	__le32 le_val;
	173	if (pdu_read(pdu, &le_val, sizeof(le_val))) {
	174	errcode = -EFAULT;
	175	break;
	176	}
	177	*gid = make_kgid(&init_user_ns,
	178	le32_to_cpu(le_val));
	179	} break;
ace51c4d EVH	180	case 'Q':{
	181	struct p9_qid *qid =
	182	va_arg(ap, struct p9_qid *);
	183
342fee1d	184	errcode = p9pdu_readf(pdu, proto_version, "bdq",
ace51c4d EVH	185	&qid->type, &qid->version,
	186	&qid->path);
	187	}
	188	break;
	189	case 'S':{
	190	struct p9_wstat *stbuf =
	191	va_arg(ap, struct p9_wstat *);
	192
f0a0ac2e	193	memset(stbuf, 0, sizeof(struct p9_wstat));
447c5094 EB	194	stbuf->n_uid = stbuf->n_muid = INVALID_UID;
	195	stbuf->n_gid = INVALID_GID;
	196
ace51c4d	197	errcode =
342fee1d	198	p9pdu_readf(pdu, proto_version,
447c5094	199	"wwdQdddqssss?sugu",
ace51c4d EVH	200	&stbuf->size, &stbuf->type,
	201	&stbuf->dev, &stbuf->qid,
	202	&stbuf->mode, &stbuf->atime,
	203	&stbuf->mtime, &stbuf->length,
	204	&stbuf->name, &stbuf->uid,
	205	&stbuf->gid, &stbuf->muid,
	206	&stbuf->extension,
	207	&stbuf->n_uid, &stbuf->n_gid,
	208	&stbuf->n_muid);
	209	if (errcode)
	210	p9stat_free(stbuf);
	211	}
	212	break;
	213	case 'D':{
219fd58b	214	uint32_t count = va_arg(ap, uint32_t );
ace51c4d EVH	215	void data = va_arg(ap, void );
	216
	217	errcode =
342fee1d	218	p9pdu_readf(pdu, proto_version, "d", count);
ace51c4d EVH	219	if (!errcode) {
ace51c4d EVH	220	*count =
219fd58b	221	min_t(uint32_t, *count,
01b0c5cf	222	pdu->size - pdu->offset);
ace51c4d EVH	223	*data = &pdu->sdata[pdu->offset];
	224	}
	225	}
	226	break;
	227	case 'T':{
b76225e2	228	uint16_t nwname = va_arg(ap, uint16_t );
ace51c4d EVH	229	char *wnames = va_arg(ap, char *);
ace51c4d EVH	230
342fee1d SK	231	errcode = p9pdu_readf(pdu, proto_version,
342fee1d SK	232	"w", nwname);
ace51c4d EVH	233	if (!errcode) {
ace51c4d EVH	234	*wnames =
6da2ec56 KC	235	kmalloc_array(*nwname,
	236	sizeof(char *),
	237	GFP_NOFS);
ace51c4d EVH	238	if (!*wnames)
	239	errcode = -ENOMEM;
	240	}
	241
	242	if (!errcode) {
	243	int i;
	244
	245	for (i = 0; i < *nwname; i++) {
	246	errcode =
342fee1d SK	247	p9pdu_readf(pdu,
342fee1d SK	248	proto_version,
ace51c4d EVH	249	"s",
	250	&(*wnames)[i]);
	251	if (errcode)
	252	break;
	253	}
	254	}
	255
	256	if (errcode) {
	257	if (*wnames) {
	258	int i;
	259
	260	for (i = 0; i < *nwname; i++)
	261	kfree((*wnames)[i]);
	262	}
	263	kfree(*wnames);
	264	*wnames = NULL;
	265	}
	266	}
	267	break;
	268	case 'R':{
6250a8ba	269	uint16_t nwqid = va_arg(ap, uint16_t );
ace51c4d EVH	270	struct p9_qid **wqids =
	271	va_arg(ap, struct p9_qid **);
	272
	273	*wqids = NULL;
	274
	275	errcode =
342fee1d	276	p9pdu_readf(pdu, proto_version, "w", nwqid);
ace51c4d EVH	277	if (!errcode) {
ace51c4d EVH	278	*wqids =
6da2ec56 KC	279	kmalloc_array(*nwqid,
	280	sizeof(struct p9_qid),
	281	GFP_NOFS);
ace51c4d EVH	282	if (*wqids == NULL)
	283	errcode = -ENOMEM;
	284	}
	285
	286	if (!errcode) {
	287	int i;
	288
	289	for (i = 0; i < *nwqid; i++) {
	290	errcode =
342fee1d SK	291	p9pdu_readf(pdu,
342fee1d SK	292	proto_version,
ace51c4d EVH	293	"Q",
	294	&(*wqids)[i]);
	295	if (errcode)
	296	break;
	297	}
	298	}
	299
	300	if (errcode) {
	301	kfree(*wqids);
	302	*wqids = NULL;
	303	}
	304	}
	305	break;
f0853122 SK	306	case 'A': {
	307	struct p9_stat_dotl *stbuf =
	308	va_arg(ap, struct p9_stat_dotl *);
	309
	310	memset(stbuf, 0, sizeof(struct p9_stat_dotl));
	311	errcode =
	312	p9pdu_readf(pdu, proto_version,
447c5094	313	"qQdugqqqqqqqqqqqqqqq",
f0853122 SK	314	&stbuf->st_result_mask,
	315	&stbuf->qid,
	316	&stbuf->st_mode,
	317	&stbuf->st_uid, &stbuf->st_gid,
	318	&stbuf->st_nlink,
	319	&stbuf->st_rdev, &stbuf->st_size,
	320	&stbuf->st_blksize, &stbuf->st_blocks,
	321	&stbuf->st_atime_sec,
	322	&stbuf->st_atime_nsec,
	323	&stbuf->st_mtime_sec,
	324	&stbuf->st_mtime_nsec,
	325	&stbuf->st_ctime_sec,
	326	&stbuf->st_ctime_nsec,
	327	&stbuf->st_btime_sec,
	328	&stbuf->st_btime_nsec,
	329	&stbuf->st_gen,
	330	&stbuf->st_data_version);
	331	}
	332	break;
ace51c4d	333	case '?':
c56e4acf SK	334	if ((proto_version != p9_proto_2000u) &&
c56e4acf SK	335	(proto_version != p9_proto_2000L))
ace51c4d EVH	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
342fee1d SK	351	p9pdu_vwritef(struct p9_fcall pdu, int proto_version, const char fmt,
342fee1d SK	352	va_list ap)
ace51c4d EVH	353	{
	354	const char *ptr;
	355	int errcode = 0;
	356
	357	for (ptr = fmt; *ptr; ptr++) {
	358	switch (*ptr) {
	359	case 'b':{
	360	int8_t val = va_arg(ap, int);
	361	if (pdu_write(pdu, &val, sizeof(val)))
	362	errcode = -EFAULT;
	363	}
	364	break;
	365	case 'w':{
beeebc92	366	__le16 val = cpu_to_le16(va_arg(ap, int));
ace51c4d EVH	367	if (pdu_write(pdu, &val, sizeof(val)))
	368	errcode = -EFAULT;
	369	}
	370	break;
	371	case 'd':{
beeebc92	372	__le32 val = cpu_to_le32(va_arg(ap, int32_t));
ace51c4d EVH	373	if (pdu_write(pdu, &val, sizeof(val)))
	374	errcode = -EFAULT;
	375	}
	376	break;
	377	case 'q':{
beeebc92	378	__le64 val = cpu_to_le64(va_arg(ap, int64_t));
ace51c4d EVH	379	if (pdu_write(pdu, &val, sizeof(val)))
	380	errcode = -EFAULT;
	381	}
	382	break;
	383	case 's':{
e45c5405	384	const char sptr = va_arg(ap, const char );
219fd58b	385	uint16_t len = 0;
e45c5405	386	if (sptr)
d31bb4f0	387	len = min_t(size_t, strlen(sptr),
219fd58b	388	USHRT_MAX);
ace51c4d	389
342fee1d SK	390	errcode = p9pdu_writef(pdu, proto_version,
342fee1d SK	391	"w", len);
e45c5405	392	if (!errcode && pdu_write(pdu, sptr, len))
ace51c4d EVH	393	errcode = -EFAULT;
	394	}
	395	break;
97fc8b1e EB	396	case 'u': {
	397	kuid_t uid = va_arg(ap, kuid_t);
	398	__le32 val = cpu_to_le32(
	399	from_kuid(&init_user_ns, uid));
	400	if (pdu_write(pdu, &val, sizeof(val)))
	401	errcode = -EFAULT;
	402	} break;
	403	case 'g': {
	404	kgid_t gid = va_arg(ap, kgid_t);
	405	__le32 val = cpu_to_le32(
	406	from_kgid(&init_user_ns, gid));
	407	if (pdu_write(pdu, &val, sizeof(val)))
	408	errcode = -EFAULT;
	409	} break;
ace51c4d EVH	410	case 'Q':{
	411	const struct p9_qid *qid =
	412	va_arg(ap, const struct p9_qid *);
	413	errcode =
342fee1d	414	p9pdu_writef(pdu, proto_version, "bdq",
ace51c4d EVH	415	qid->type, qid->version,
	416	qid->path);
	417	} break;
	418	case 'S':{
	419	const struct p9_wstat *stbuf =
	420	va_arg(ap, const struct p9_wstat *);
	421	errcode =
342fee1d	422	p9pdu_writef(pdu, proto_version,
447c5094	423	"wwdQdddqssss?sugu",
ace51c4d	424	stbuf->size, stbuf->type,
51a87c55	425	stbuf->dev, &stbuf->qid,
ace51c4d EVH	426	stbuf->mode, stbuf->atime,
	427	stbuf->mtime, stbuf->length,
	428	stbuf->name, stbuf->uid,
	429	stbuf->gid, stbuf->muid,
	430	stbuf->extension, stbuf->n_uid,
	431	stbuf->n_gid, stbuf->n_muid);
	432	} break;
4f3b35c1	433	case 'V':{
6250a8ba	434	uint32_t count = va_arg(ap, uint32_t);
4f3b35c1 AV	435	struct iov_iter *from =
4f3b35c1 AV	436	va_arg(ap, struct iov_iter *);
342fee1d SK	437	errcode = p9pdu_writef(pdu, proto_version, "d",
342fee1d SK	438	count);
4f3b35c1	439	if (!errcode && pdu_write_u(pdu, from, count))
51a87c55 EVH	440	errcode = -EFAULT;
	441	}
	442	break;
ace51c4d	443	case 'T':{
b76225e2	444	uint16_t nwname = va_arg(ap, int);
ace51c4d EVH	445	const char wnames = va_arg(ap, const char );
ace51c4d EVH	446
342fee1d SK	447	errcode = p9pdu_writef(pdu, proto_version, "w",
342fee1d SK	448	nwname);
ace51c4d EVH	449	if (!errcode) {
	450	int i;
	451
	452	for (i = 0; i < nwname; i++) {
	453	errcode =
342fee1d SK	454	p9pdu_writef(pdu,
342fee1d SK	455	proto_version,
ace51c4d EVH	456	"s",
	457	wnames[i]);
	458	if (errcode)
	459	break;
	460	}
	461	}
	462	}
	463	break;
	464	case 'R':{
6250a8ba	465	uint16_t nwqid = va_arg(ap, int);
ace51c4d EVH	466	struct p9_qid *wqids =
	467	va_arg(ap, struct p9_qid *);
	468
342fee1d SK	469	errcode = p9pdu_writef(pdu, proto_version, "w",
342fee1d SK	470	nwqid);
ace51c4d EVH	471	if (!errcode) {
	472	int i;
	473
	474	for (i = 0; i < nwqid; i++) {
	475	errcode =
342fee1d SK	476	p9pdu_writef(pdu,
342fee1d SK	477	proto_version,
ace51c4d EVH	478	"Q",
	479	&wqids[i]);
	480	if (errcode)
	481	break;
	482	}
	483	}
	484	}
	485	break;
87d7845a SK	486	case 'I':{
	487	struct p9_iattr_dotl *p9attr = va_arg(ap,
	488	struct p9_iattr_dotl *);
	489
	490	errcode = p9pdu_writef(pdu, proto_version,
447c5094	491	"ddugqqqqq",
87d7845a SK	492	p9attr->valid,
	493	p9attr->mode,
	494	p9attr->uid,
	495	p9attr->gid,
	496	p9attr->size,
	497	p9attr->atime_sec,
	498	p9attr->atime_nsec,
	499	p9attr->mtime_sec,
	500	p9attr->mtime_nsec);
	501	}
	502	break;
ace51c4d	503	case '?':
c56e4acf SK	504	if ((proto_version != p9_proto_2000u) &&
c56e4acf SK	505	(proto_version != p9_proto_2000L))
ace51c4d EVH	506	return 0;
	507	break;
	508	default:
	509	BUG();
	510	break;
	511	}
	512
	513	if (errcode)
	514	break;
	515	}
	516
	517	return errcode;
	518	}
	519
342fee1d	520	int p9pdu_readf(struct p9_fcall pdu, int proto_version, const char fmt, ...)
ace51c4d EVH	521	{
	522	va_list ap;
	523	int ret;
	524
	525	va_start(ap, fmt);
342fee1d	526	ret = p9pdu_vreadf(pdu, proto_version, fmt, ap);
ace51c4d EVH	527	va_end(ap);
	528
	529	return ret;
	530	}
	531
	532	static int
342fee1d	533	p9pdu_writef(struct p9_fcall pdu, int proto_version, const char fmt, ...)
ace51c4d EVH	534	{
	535	va_list ap;
	536	int ret;
	537
	538	va_start(ap, fmt);
342fee1d	539	ret = p9pdu_vwritef(pdu, proto_version, fmt, ap);
ace51c4d EVH	540	va_end(ap);
	541
	542	return ret;
	543	}
51a87c55	544
348b5901	545	int p9stat_read(struct p9_client clnt, char buf, int len, struct p9_wstat *st)
02da398b EVH	546	{
02da398b EVH	547	struct p9_fcall fake_pdu;
e7f4b8f1	548	int ret;
02da398b EVH	549
	550	fake_pdu.size = len;
	551	fake_pdu.capacity = len;
	552	fake_pdu.sdata = buf;
	553	fake_pdu.offset = 0;
	554
348b5901	555	ret = p9pdu_readf(&fake_pdu, clnt->proto_version, "S", st);
e7f4b8f1	556	if (ret) {
5d385153	557	p9_debug(P9_DEBUG_9P, "<<< p9stat_read failed: %d\n", ret);
348b5901	558	trace_9p_protocol_dump(clnt, &fake_pdu);
2803cf43	559	return ret;
e7f4b8f1 EVH	560	}
e7f4b8f1 EVH	561
2803cf43	562	return fake_pdu.offset;
02da398b EVH	563	}
	564	EXPORT_SYMBOL(p9stat_read);
	565
51a87c55 EVH	566	int p9pdu_prepare(struct p9_fcall *pdu, int16_t tag, int8_t type)
51a87c55 EVH	567	{
9bb6c10a	568	pdu->id = type;
51a87c55 EVH	569	return p9pdu_writef(pdu, 0, "dbw", 0, type, tag);
	570	}
	571
348b5901	572	int p9pdu_finalize(struct p9_client clnt, struct p9_fcall pdu)
51a87c55 EVH	573	{
	574	int size = pdu->size;
	575	int err;
	576
	577	pdu->size = 0;
	578	err = p9pdu_writef(pdu, 0, "d", size);
	579	pdu->size = size;
	580
348b5901	581	trace_9p_protocol_dump(clnt, pdu);
5d385153 JP	582	p9_debug(P9_DEBUG_9P, ">>> size=%d type: %d tag: %d\n",
5d385153 JP	583	pdu->size, pdu->id, pdu->tag);
e7f4b8f1	584
51a87c55 EVH	585	return err;
	586	}
	587
	588	void p9pdu_reset(struct p9_fcall *pdu)
	589	{
	590	pdu->offset = 0;
	591	pdu->size = 0;
	592	}
7751bdb3	593
348b5901 AK	594	int p9dirent_read(struct p9_client clnt, char buf, int len,
348b5901 AK	595	struct p9_dirent *dirent)
7751bdb3 SK	596	{
	597	struct p9_fcall fake_pdu;
	598	int ret;
	599	char *nameptr;
	600
	601	fake_pdu.size = len;
	602	fake_pdu.capacity = len;
	603	fake_pdu.sdata = buf;
	604	fake_pdu.offset = 0;
	605
348b5901 AK	606	ret = p9pdu_readf(&fake_pdu, clnt->proto_version, "Qqbs", &dirent->qid,
348b5901 AK	607	&dirent->d_off, &dirent->d_type, &nameptr);
7751bdb3	608	if (ret) {
5d385153	609	p9_debug(P9_DEBUG_9P, "<<< p9dirent_read failed: %d\n", ret);
348b5901	610	trace_9p_protocol_dump(clnt, &fake_pdu);
ef5305f1	611	return ret;
7751bdb3 SK	612	}
7751bdb3 SK	613
ef5305f1 DM	614	ret = strscpy(dirent->d_name, nameptr, sizeof(dirent->d_name));
	615	if (ret < 0) {
	616	p9_debug(P9_DEBUG_ERROR,
	617	"On the wire dirent name too long: %s\n",
	618	nameptr);
	619	kfree(nameptr);
	620	return ret;
	621	}
1b0bcbcf	622	kfree(nameptr);
7751bdb3	623
7751bdb3 SK	624	return fake_pdu.offset;
	625	}
	626	EXPORT_SYMBOL(p9dirent_read);