[people/arne_f/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 <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, ...);

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;
}

/*
	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 '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;
}
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>
	30	#include <net/9p/9p.h>
	31	#include <net/9p/client.h>
	32	#include "protocol.h"
	33
	34	#ifndef MIN
	35	#define MIN(a, b) (((a) < (b)) ? (a) : (b))
	36	#endif
	37
	38	#ifndef MAX
	39	#define MAX(a, b) (((a) > (b)) ? (a) : (b))
	40	#endif
	41
	42	#ifndef offset_of
	43	#define offset_of(type, memb) \
	44	((unsigned long)(&((type *)0)->memb))
	45	#endif
	46	#ifndef container_of
	47	#define container_of(obj, type, memb) \
	48	((type )(((char )obj) - offset_of(type, memb)))
	49	#endif
	50
	51	static int
	52	p9pdu_writef(struct p9_fcall pdu, int optional, const char fmt, ...);
	53
	54	void p9stat_free(struct p9_wstat *stbuf)
	55	{
	56	kfree(stbuf->name);
	57	kfree(stbuf->uid);
	58	kfree(stbuf->gid);
	59	kfree(stbuf->muid);
	60	kfree(stbuf->extension);
	61	}
	62	EXPORT_SYMBOL(p9stat_free);
	63
	64	static size_t pdu_read(struct p9_fcall pdu, void data, size_t size)
65	{
66	size_t len = MIN(pdu->size - pdu->offset, size);
67	memcpy(data, &pdu->sdata[pdu->offset], len);
68	pdu->offset += len;
69	return size - len;
70	}
71
72	static size_t pdu_write(struct p9_fcall pdu, const void data, size_t size)
73	{
74	size_t len = MIN(pdu->capacity - pdu->size, size);
75	memcpy(&pdu->sdata[pdu->size], data, len);
76	pdu->size += len;
77	return size - len;
78	}
79
80	/*
81	b - int8_t
82	w - int16_t
83	d - int32_t
84	q - int64_t
85	s - string
86	S - stat
87	Q - qid
88	D - data blob (int32_t size followed by void *, results are not freed)
89	T - array of strings (int16_t count, followed by strings)
90	R - array of qids (int16_t count, followed by qids)
91	? - if optional = 1, continue parsing
92	*/
93
94	static int
95	p9pdu_vreadf(struct p9_fcall pdu, int optional, const char fmt, va_list ap)
96	{
97	const char *ptr;
98	int errcode = 0;
99
100	for (ptr = fmt; *ptr; ptr++) {
101	switch (*ptr) {
102	case 'b':{
103	int8_t val = va_arg(ap, int8_t );
104	if (pdu_read(pdu, val, sizeof(*val))) {
105	errcode = -EFAULT;
106	break;
107	}
108	}
109	break;
110	case 'w':{
111	int16_t val = va_arg(ap, int16_t );
112	if (pdu_read(pdu, val, sizeof(*val))) {
113	errcode = -EFAULT;
114	break;
115	}
116	val = cpu_to_le16(val);
117	}
118	break;
119	case 'd':{
120	int32_t val = va_arg(ap, int32_t );
121	if (pdu_read(pdu, val, sizeof(*val))) {
122	errcode = -EFAULT;
123	break;
124	}
125	val = cpu_to_le32(val);
126	}
127	break;
128	case 'q':{
129	int64_t val = va_arg(ap, int64_t );
130	if (pdu_read(pdu, val, sizeof(*val))) {
131	errcode = -EFAULT;
132	break;
133	}
134	val = cpu_to_le64(val);
135	}
136	break;
137	case 's':{
138	char ptr = va_arg(ap, char );
139	int16_t len;
140	int size;
141
142	errcode = p9pdu_readf(pdu, optional, "w", &len);
143	if (errcode)
144	break;
145
146	size = MAX(len, 0);
147
148	*ptr = kmalloc(size + 1, GFP_KERNEL);
149	if (*ptr == NULL) {
150	errcode = -EFAULT;
151	break;
152	}
153	if (pdu_read(pdu, *ptr, size)) {
154	errcode = -EFAULT;
155	kfree(*ptr);
156	*ptr = NULL;
157	} else
158	(*ptr)[size] = 0;
159	}
160	break;
161	case 'Q':{
162	struct p9_qid *qid =
163	va_arg(ap, struct p9_qid *);
164
165	errcode = p9pdu_readf(pdu, optional, "bdq",
166	&qid->type, &qid->version,
167	&qid->path);
168	}
169	break;
170	case 'S':{
171	struct p9_wstat *stbuf =
172	va_arg(ap, struct p9_wstat *);
173
174	stbuf->extension = NULL;
175	stbuf->n_uid = stbuf->n_gid = stbuf->n_muid =
176	-1;
177
178	errcode =
179	p9pdu_readf(pdu, optional,
180	"wwdQdddqssss?sddd",
181	&stbuf->size, &stbuf->type,
182	&stbuf->dev, &stbuf->qid,
183	&stbuf->mode, &stbuf->atime,
184	&stbuf->mtime, &stbuf->length,
185	&stbuf->name, &stbuf->uid,
186	&stbuf->gid, &stbuf->muid,
187	&stbuf->extension,
188	&stbuf->n_uid, &stbuf->n_gid,
189	&stbuf->n_muid);
190	if (errcode)
191	p9stat_free(stbuf);
192	}
193	break;
194	case 'D':{
195	int32_t count = va_arg(ap, int32_t );
196	void data = va_arg(ap, void );
197
198	errcode =
199	p9pdu_readf(pdu, optional, "d", count);
200	if (!errcode) {
201	*count =
202	MIN(*count,
203	pdu->size - pdu->offset);
204	*data = &pdu->sdata[pdu->offset];
205	}
206	}
207	break;
208	case 'T':{
209	int16_t nwname = va_arg(ap, int16_t );
210	char *wnames = va_arg(ap, char *);
211
212	errcode =
213	p9pdu_readf(pdu, optional, "w", nwname);
214	if (!errcode) {
215	*wnames =
216	kmalloc(sizeof(char ) *nwname,
217	GFP_KERNEL);
218	if (!*wnames)
219	errcode = -ENOMEM;
220	}
221
222	if (!errcode) {
223	int i;
224
225	for (i = 0; i < *nwname; i++) {
226	errcode =
227	p9pdu_readf(pdu, optional,
228	"s",
229	&(*wnames)[i]);
230	if (errcode)
231	break;
232	}
233	}
234
235	if (errcode) {
236	if (*wnames) {
237	int i;
238
239	for (i = 0; i < *nwname; i++)
240	kfree((*wnames)[i]);
241	}
242	kfree(*wnames);
243	*wnames = NULL;
244	}
245	}
246	break;
247	case 'R':{
248	int16_t nwqid = va_arg(ap, int16_t );
249	struct p9_qid **wqids =
250	va_arg(ap, struct p9_qid **);
251
252	*wqids = NULL;
253
254	errcode =
255	p9pdu_readf(pdu, optional, "w", nwqid);
256	if (!errcode) {
257	*wqids =
258	kmalloc(nwqid
259	sizeof(struct p9_qid),
260	GFP_KERNEL);
261	if (*wqids == NULL)
262	errcode = -ENOMEM;
263	}
264
265	if (!errcode) {
266	int i;
267
268	for (i = 0; i < *nwqid; i++) {
269	errcode =
270	p9pdu_readf(pdu, optional,
271	"Q",
272	&(*wqids)[i]);
273	if (errcode)
274	break;
275	}
276	}
277
278	if (errcode) {
279	kfree(*wqids);
280	*wqids = NULL;
281	}
282	}
283	break;
284	case '?':
285	if (!optional)
286	return 0;
287	break;
288	default:
289	BUG();
290	break;
291	}
292
293	if (errcode)
294	break;
295	}
296
297	return errcode;
298	}
299
300	int
301	p9pdu_vwritef(struct p9_fcall pdu, int optional, const char fmt, va_list ap)
302	{
303	const char *ptr;
304	int errcode = 0;
305
306	for (ptr = fmt; *ptr; ptr++) {
307	switch (*ptr) {
308	case 'b':{
309	int8_t val = va_arg(ap, int);
310	if (pdu_write(pdu, &val, sizeof(val)))
311	errcode = -EFAULT;
312	}
313	break;
314	case 'w':{
315	int16_t val = va_arg(ap, int);
316	if (pdu_write(pdu, &val, sizeof(val)))
317	errcode = -EFAULT;
318	}
319	break;
320	case 'd':{
321	int32_t val = va_arg(ap, int32_t);
322	if (pdu_write(pdu, &val, sizeof(val)))
323	errcode = -EFAULT;
324	}
325	break;
326	case 'q':{
327	int64_t val = va_arg(ap, int64_t);
328	if (pdu_write(pdu, &val, sizeof(val)))
329	errcode = -EFAULT;
330	}
331	break;
332	case 's':{
333	const char ptr = va_arg(ap, const char );
334	int16_t len = 0;
335
336	if (ptr)
337	len = MIN(strlen(ptr), USHORT_MAX);
338
339	errcode = p9pdu_writef(pdu, optional, "w", len);
340	if (!errcode && pdu_write(pdu, ptr, len))
341	errcode = -EFAULT;
342	}
343	break;
344	case 'Q':{
345	const struct p9_qid *qid =
346	va_arg(ap, const struct p9_qid *);
347	errcode =
348	p9pdu_writef(pdu, optional, "bdq",
349	qid->type, qid->version,
350	qid->path);
351	} break;
352	case 'S':{
353	const struct p9_wstat *stbuf =
354	va_arg(ap, const struct p9_wstat *);
355	errcode =
356	p9pdu_writef(pdu, optional,
357	"wwdQdddqssss?sddd",
358	stbuf->size, stbuf->type,
359	stbuf->dev, stbuf->qid,
360	stbuf->mode, stbuf->atime,
361	stbuf->mtime, stbuf->length,
362	stbuf->name, stbuf->uid,
363	stbuf->gid, stbuf->muid,
364	stbuf->extension, stbuf->n_uid,
365	stbuf->n_gid, stbuf->n_muid);
366	} break;
367	case 'D':{
368	int32_t count = va_arg(ap, int32_t);
369	const void data = va_arg(ap, const void );
370
371	errcode =
372	p9pdu_writef(pdu, optional, "d", count);
373	if (!errcode && pdu_write(pdu, data, count))
374	errcode = -EFAULT;
375	}
376	break;
377	case 'T':{
378	int16_t nwname = va_arg(ap, int);
379	const char wnames = va_arg(ap, const char );
380
381	errcode =
382	p9pdu_writef(pdu, optional, "w", nwname);
383	if (!errcode) {
384	int i;
385
386	for (i = 0; i < nwname; i++) {
387	errcode =
388	p9pdu_writef(pdu, optional,
389	"s",
390	wnames[i]);
391	if (errcode)
392	break;
393	}
394	}
395	}
396	break;
397	case 'R':{
398	int16_t nwqid = va_arg(ap, int);
399	struct p9_qid *wqids =
400	va_arg(ap, struct p9_qid *);
401
402	errcode =
403	p9pdu_writef(pdu, optional, "w", nwqid);
404	if (!errcode) {
405	int i;
406
407	for (i = 0; i < nwqid; i++) {
408	errcode =
409	p9pdu_writef(pdu, optional,
410	"Q",
411	&wqids[i]);
412	if (errcode)
413	break;
414	}
415	}
416	}
417	break;
418	case '?':
419	if (!optional)
420	return 0;
421	break;
422	default:
423	BUG();
424	break;
425	}
426
427	if (errcode)
428	break;
429	}
430
431	return errcode;
432	}
433
434	int p9pdu_readf(struct p9_fcall pdu, int optional, const char fmt, ...)
435	{
436	va_list ap;
437	int ret;
438
439	va_start(ap, fmt);
440	ret = p9pdu_vreadf(pdu, optional, fmt, ap);
441	va_end(ap);
442
443	return ret;
444	}
445
446	static int
447	p9pdu_writef(struct p9_fcall pdu, int optional, const char fmt, ...)
448	{
449	va_list ap;
450	int ret;
451
452	va_start(ap, fmt);
453	ret = p9pdu_vwritef(pdu, optional, fmt, ap);
454	va_end(ap);
455
456	return ret;
457	}