1/*-
2 * Copyright (c) 2000 Poul-Henning Kamp and Dag-Erling Co�dan Sm�rgrav
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer
10 *    in this position and unchanged.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 * 3. The name of the author may not be used to endorse or promote products
15 *    derived from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29#include <sys/cdefs.h>
30
31#include <sys/param.h>
32
33#ifdef KERNEL
34/* #include <ctype.h> */
35#include <sys/kernel.h>
36#include <sys/malloc.h>
37#include <sys/systm.h>
38#include <sys/uio.h>
39#include <sys/uio_internal.h>
40#include <sys/systm.h>
41#include <stdarg.h>
42#else /* KERNEL */
43#include <ctype.h>
44#include <stdarg.h>
45#include <stdio.h>
46#include <stdlib.h>
47#include <string.h>
48#endif /* KERNEL */
49
50#include <sys/sbuf.h>
51
52#ifdef KERNEL
53/* MALLOC_DEFINE(M_SBUF, "sbuf", "string buffers"); */
54#define	SBMALLOC(size)		_MALLOC(size, M_SBUF, M_WAITOK)
55#define	SBFREE(buf)		FREE(buf, M_SBUF)
56#else /* KERNEL */
57#define	KASSERT(e, m)
58#define	SBMALLOC(size)		malloc(size)
59#define	SBFREE(buf)		free(buf)
60#define	min(x,y)		MIN(x,y)
61
62#endif /* KERNEL */
63
64/*
65 * Predicates
66 */
67#define	SBUF_ISDYNAMIC(s)	((s)->s_flags & SBUF_DYNAMIC)
68#define	SBUF_ISDYNSTRUCT(s)	((s)->s_flags & SBUF_DYNSTRUCT)
69#define	SBUF_ISFINISHED(s)	((s)->s_flags & SBUF_FINISHED)
70#define	SBUF_HASOVERFLOWED(s)	((s)->s_flags & SBUF_OVERFLOWED)
71#define	SBUF_HASROOM(s)		((s)->s_len < (s)->s_size - 1)
72#define	SBUF_FREESPACE(s)	((s)->s_size - (s)->s_len - 1)
73#define	SBUF_CANEXTEND(s)	((s)->s_flags & SBUF_AUTOEXTEND)
74
75/*
76 * Set / clear flags
77 */
78#define	SBUF_SETFLAG(s, f)	do { (s)->s_flags |= (f); } while (0)
79#define	SBUF_CLEARFLAG(s, f)	do { (s)->s_flags &= ~(f); } while (0)
80
81#define	SBUF_MINEXTENDSIZE	16		/* Should be power of 2. */
82#define	SBUF_MAXEXTENDSIZE	PAGE_SIZE
83#define	SBUF_MAXEXTENDINCR	PAGE_SIZE
84
85/*
86 * Debugging support
87 */
88#if defined(KERNEL) && defined(INVARIANTS)
89static void
90_assert_sbuf_integrity(const char *fun, struct sbuf *s)
91{
92	KASSERT(s != NULL,
93	    ("%s called with a NULL sbuf pointer", fun));
94	KASSERT(s->s_buf != NULL,
95	    ("%s called with uninitialized or corrupt sbuf", fun));
96	KASSERT(s->s_len < s->s_size,
97	    ("wrote past end of sbuf (%d >= %d)", s->s_len, s->s_size));
98}
99
100static void
101_assert_sbuf_state(const char *fun, struct sbuf *s, int state)
102{
103	KASSERT((s->s_flags & SBUF_FINISHED) == state,
104	    ("%s called with %sfinished or corrupt sbuf", fun,
105	    (state ? "un" : "")));
106}
107#define	assert_sbuf_integrity(s) _assert_sbuf_integrity(__func__, (s))
108#define	assert_sbuf_state(s, i)	 _assert_sbuf_state(__func__, (s), (i))
109#else /* KERNEL && INVARIANTS */
110#define	assert_sbuf_integrity(s) do { } while (0)
111#define	assert_sbuf_state(s, i)	 do { } while (0)
112#endif /* KERNEL && INVARIANTS */
113
114static int
115sbuf_extendsize(int size)
116{
117	int newsize;
118
119	newsize = SBUF_MINEXTENDSIZE;
120	while (newsize < size) {
121		if (newsize < (int)SBUF_MAXEXTENDSIZE)
122			newsize *= 2;
123		else
124			newsize += SBUF_MAXEXTENDINCR;
125	}
126
127	return (newsize);
128}
129
130
131/*
132 * Extend an sbuf.
133 */
134static int
135sbuf_extend(struct sbuf *s, int addlen)
136{
137	char *newbuf;
138	int newsize;
139
140	if (!SBUF_CANEXTEND(s))
141		return (-1);
142
143	newsize = sbuf_extendsize(s->s_size + addlen);
144	newbuf = (char *)SBMALLOC(newsize);
145	if (newbuf == NULL)
146		return (-1);
147	bcopy(s->s_buf, newbuf, s->s_size);
148	if (SBUF_ISDYNAMIC(s))
149		SBFREE(s->s_buf);
150	else
151		SBUF_SETFLAG(s, SBUF_DYNAMIC);
152	s->s_buf = newbuf;
153	s->s_size = newsize;
154	return (0);
155}
156
157/*
158 * Initialize an sbuf.
159 * If buf is non-NULL, it points to a static or already-allocated string
160 * big enough to hold at least length characters.
161 */
162struct sbuf *
163sbuf_new(struct sbuf *s, char *buf, int length, int flags)
164{
165	KASSERT(length >= 0,
166	    ("attempt to create an sbuf of negative length (%d)", length));
167	KASSERT((flags & ~SBUF_USRFLAGMSK) == 0,
168	    ("%s called with invalid flags", __func__));
169
170	flags &= SBUF_USRFLAGMSK;
171	if (s == NULL) {
172		s = (struct sbuf *)SBMALLOC(sizeof *s);
173		if (s == NULL)
174			return (NULL);
175		bzero(s, sizeof *s);
176		s->s_flags = flags;
177		SBUF_SETFLAG(s, SBUF_DYNSTRUCT);
178	} else {
179		bzero(s, sizeof *s);
180		s->s_flags = flags;
181	}
182	s->s_size = length;
183	if (buf) {
184		s->s_buf = buf;
185		return (s);
186	}
187	if (flags & SBUF_AUTOEXTEND)
188		s->s_size = sbuf_extendsize(s->s_size);
189	s->s_buf = (char *)SBMALLOC(s->s_size);
190	if (s->s_buf == NULL) {
191		if (SBUF_ISDYNSTRUCT(s))
192			SBFREE(s);
193		return (NULL);
194	}
195	SBUF_SETFLAG(s, SBUF_DYNAMIC);
196	return (s);
197}
198
199#ifdef KERNEL
200/*
201 * Create an sbuf with uio data
202 */
203struct sbuf *
204sbuf_uionew(struct sbuf *s, struct uio *uio, int *error)
205{
206	KASSERT(uio != NULL,
207	    ("%s called with NULL uio pointer", __func__));
208	KASSERT(error != NULL,
209	    ("%s called with NULL error pointer", __func__));
210
211	s = sbuf_new(s, NULL, uio_resid(uio) + 1, 0);
212	if (s == NULL) {
213		*error = ENOMEM;
214		return (NULL);
215	}
216	*error = uiomove(s->s_buf, uio_resid(uio), uio);
217	if (*error != 0) {
218		sbuf_delete(s);
219		return (NULL);
220	}
221	s->s_len = s->s_size - 1;
222	*error = 0;
223	return (s);
224}
225#endif
226
227/*
228 * Clear an sbuf and reset its position.
229 */
230void
231sbuf_clear(struct sbuf *s)
232{
233	assert_sbuf_integrity(s);
234	/* don't care if it's finished or not */
235
236	SBUF_CLEARFLAG(s, SBUF_FINISHED);
237	SBUF_CLEARFLAG(s, SBUF_OVERFLOWED);
238	s->s_len = 0;
239}
240
241/*
242 * Set the sbuf's end position to an arbitrary value.
243 * Effectively truncates the sbuf at the new position.
244 */
245int
246sbuf_setpos(struct sbuf *s, int pos)
247{
248	assert_sbuf_integrity(s);
249	assert_sbuf_state(s, 0);
250
251	KASSERT(pos >= 0,
252	    ("attempt to seek to a negative position (%d)", pos));
253	KASSERT(pos < s->s_size,
254	    ("attempt to seek past end of sbuf (%d >= %d)", pos, s->s_size));
255
256	if (pos < 0 || pos > s->s_len)
257		return (-1);
258	s->s_len = pos;
259	return (0);
260}
261
262/*
263 * Append a byte string to an sbuf.
264 */
265int
266sbuf_bcat(struct sbuf *s, const void *buf, size_t len)
267{
268	const char *str = buf;
269
270	assert_sbuf_integrity(s);
271	assert_sbuf_state(s, 0);
272
273	if (SBUF_HASOVERFLOWED(s))
274		return (-1);
275
276	for (; len; len--) {
277		if (!SBUF_HASROOM(s) && sbuf_extend(s, len) < 0)
278			break;
279		s->s_buf[s->s_len++] = *str++;
280	}
281	if (len) {
282		SBUF_SETFLAG(s, SBUF_OVERFLOWED);
283		return (-1);
284	}
285	return (0);
286}
287
288#ifdef KERNEL
289/*
290 * Copy a byte string from userland into an sbuf.
291 */
292int
293sbuf_bcopyin(struct sbuf *s, const void *uaddr, size_t len)
294{
295	assert_sbuf_integrity(s);
296	assert_sbuf_state(s, 0);
297
298	if (SBUF_HASOVERFLOWED(s))
299		return (-1);
300
301	if (len == 0)
302		return (0);
303	if (len > (unsigned) SBUF_FREESPACE(s)) {
304		sbuf_extend(s, len - SBUF_FREESPACE(s));
305		len = min(len, SBUF_FREESPACE(s));
306	}
307	if (copyin(CAST_USER_ADDR_T(uaddr), s->s_buf + s->s_len, len) != 0)
308		return (-1);
309	s->s_len += len;
310
311	return (0);
312}
313#endif
314
315/*
316 * Copy a byte string into an sbuf.
317 */
318int
319sbuf_bcpy(struct sbuf *s, const void *buf, size_t len)
320{
321	assert_sbuf_integrity(s);
322	assert_sbuf_state(s, 0);
323
324	sbuf_clear(s);
325	return (sbuf_bcat(s, buf, len));
326}
327
328/*
329 * Append a string to an sbuf.
330 */
331int
332sbuf_cat(struct sbuf *s, const char *str)
333{
334	assert_sbuf_integrity(s);
335	assert_sbuf_state(s, 0);
336
337	if (SBUF_HASOVERFLOWED(s))
338		return (-1);
339
340	while (*str) {
341		if (!SBUF_HASROOM(s) && sbuf_extend(s, strlen(str)) < 0)
342			break;
343		s->s_buf[s->s_len++] = *str++;
344	}
345	if (*str) {
346		SBUF_SETFLAG(s, SBUF_OVERFLOWED);
347		return (-1);
348	}
349	return (0);
350}
351
352#ifdef KERNEL
353/*
354 * Append a string from userland to an sbuf.
355 */
356int
357sbuf_copyin(struct sbuf *s, const void *uaddr, size_t len)
358{
359	size_t done;
360
361	assert_sbuf_integrity(s);
362	assert_sbuf_state(s, 0);
363
364	if (SBUF_HASOVERFLOWED(s))
365		return (-1);
366
367	if (len == 0)
368		len = SBUF_FREESPACE(s);	/* XXX return 0? */
369	if (len > (unsigned) SBUF_FREESPACE(s)) {
370		sbuf_extend(s, len);
371		len = min(len, SBUF_FREESPACE(s));
372	}
373	switch (copyinstr(CAST_USER_ADDR_T(uaddr), s->s_buf + s->s_len, len + 1, &done)) {
374	case ENAMETOOLONG:
375		SBUF_SETFLAG(s, SBUF_OVERFLOWED);
376		/* fall through */
377	case 0:
378		s->s_len += done - 1;
379		break;
380	default:
381		return (-1);	/* XXX */
382	}
383
384	return (done);
385}
386#endif
387
388/*
389 * Copy a string into an sbuf.
390 */
391int
392sbuf_cpy(struct sbuf *s, const char *str)
393{
394	assert_sbuf_integrity(s);
395	assert_sbuf_state(s, 0);
396
397	sbuf_clear(s);
398	return (sbuf_cat(s, str));
399}
400
401/*
402 * Format the given argument list and append the resulting string to an sbuf.
403 */
404int
405sbuf_vprintf(struct sbuf *s, const char *fmt, va_list ap)
406{
407	__builtin_va_list ap_copy; /* XXX tduffy - blame on him */
408	int len;
409
410	assert_sbuf_integrity(s);
411	assert_sbuf_state(s, 0);
412
413	KASSERT(fmt != NULL,
414	    ("%s called with a NULL format string", __func__));
415
416	if (SBUF_HASOVERFLOWED(s))
417		return (-1);
418
419	do {
420		va_copy(ap_copy, ap);
421		len = vsnprintf(&s->s_buf[s->s_len], SBUF_FREESPACE(s) + 1,
422		    fmt, ap_copy);
423		va_end(ap_copy);
424	} while (len > SBUF_FREESPACE(s) &&
425	    sbuf_extend(s, len - SBUF_FREESPACE(s)) == 0);
426
427	/*
428	 * s->s_len is the length of the string, without the terminating nul.
429	 * When updating s->s_len, we must subtract 1 from the length that
430	 * we passed into vsnprintf() because that length includes the
431	 * terminating nul.
432	 *
433	 * vsnprintf() returns the amount that would have been copied,
434	 * given sufficient space, hence the min() calculation below.
435	 */
436	s->s_len += min(len, SBUF_FREESPACE(s));
437	if (!SBUF_HASROOM(s) && !SBUF_CANEXTEND(s))
438		SBUF_SETFLAG(s, SBUF_OVERFLOWED);
439
440	KASSERT(s->s_len < s->s_size,
441	    ("wrote past end of sbuf (%d >= %d)", s->s_len, s->s_size));
442
443	if (SBUF_HASOVERFLOWED(s))
444		return (-1);
445	return (0);
446}
447
448/*
449 * Format the given arguments and append the resulting string to an sbuf.
450 */
451int
452sbuf_printf(struct sbuf *s, const char *fmt, ...)
453{
454	va_list ap;
455	int result;
456
457	va_start(ap, fmt);
458	result = sbuf_vprintf(s, fmt, ap);
459	va_end(ap);
460	return(result);
461}
462
463/*
464 * Append a character to an sbuf.
465 */
466int
467sbuf_putc(struct sbuf *s, int c)
468{
469	assert_sbuf_integrity(s);
470	assert_sbuf_state(s, 0);
471
472	if (SBUF_HASOVERFLOWED(s))
473		return (-1);
474
475	if (!SBUF_HASROOM(s) && sbuf_extend(s, 1) < 0) {
476		SBUF_SETFLAG(s, SBUF_OVERFLOWED);
477		return (-1);
478	}
479	if (c != '\0')
480	    s->s_buf[s->s_len++] = c;
481	return (0);
482}
483
484static inline int
485isspace(char ch)
486{
487  return (ch == ' ' || ch == '\n' || ch == '\t');
488}
489
490/*
491 * Trim whitespace characters from end of an sbuf.
492 */
493int
494sbuf_trim(struct sbuf *s)
495{
496	assert_sbuf_integrity(s);
497	assert_sbuf_state(s, 0);
498
499	if (SBUF_HASOVERFLOWED(s))
500		return (-1);
501
502	while (s->s_len && isspace(s->s_buf[s->s_len-1]))
503		--s->s_len;
504
505	return (0);
506}
507
508/*
509 * Check if an sbuf overflowed
510 */
511int
512sbuf_overflowed(struct sbuf *s)
513{
514    return SBUF_HASOVERFLOWED(s);
515}
516
517/*
518 * Finish off an sbuf.
519 */
520void
521sbuf_finish(struct sbuf *s)
522{
523	assert_sbuf_integrity(s);
524	assert_sbuf_state(s, 0);
525
526	s->s_buf[s->s_len] = '\0';
527	SBUF_CLEARFLAG(s, SBUF_OVERFLOWED);
528	SBUF_SETFLAG(s, SBUF_FINISHED);
529}
530
531/*
532 * Return a pointer to the sbuf data.
533 */
534char *
535sbuf_data(struct sbuf *s)
536{
537	assert_sbuf_integrity(s);
538	assert_sbuf_state(s, SBUF_FINISHED);
539
540	return s->s_buf;
541}
542
543/*
544 * Return the length of the sbuf data.
545 */
546int
547sbuf_len(struct sbuf *s)
548{
549	assert_sbuf_integrity(s);
550	/* don't care if it's finished or not */
551
552	if (SBUF_HASOVERFLOWED(s))
553		return (-1);
554	return s->s_len;
555}
556
557/*
558 * Clear an sbuf, free its buffer if necessary.
559 */
560void
561sbuf_delete(struct sbuf *s)
562{
563	int isdyn;
564
565	assert_sbuf_integrity(s);
566	/* don't care if it's finished or not */
567
568	if (SBUF_ISDYNAMIC(s))
569		SBFREE(s->s_buf);
570	isdyn = SBUF_ISDYNSTRUCT(s);
571	bzero(s, sizeof *s);
572	if (isdyn)
573		SBFREE(s);
574}
575
576/*
577 * Check if an sbuf has been finished.
578 */
579int
580sbuf_done(struct sbuf *s)
581{
582
583	return(SBUF_ISFINISHED(s));
584}
585