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Commit	Line	Data
	1	/*-
	2	* Copyright (c) 2009 David Schultz <das@FreeBSD.org>
	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	* 2. Redistributions in binary form must reproduce the above copyright
	11	* notice, this list of conditions and the following disclaimer in the
	12	* documentation and/or other materials provided with the distribution.
	13	*
	14	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
	15	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	16	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	17	* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
	18	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	19	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	20	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	21	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	22	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	23	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	24	* SUCH DAMAGE.
	25	*/
	26
	27	#include <sys/cdefs.h>
	28	__FBSDID("$FreeBSD: src/lib/libc/stdio/getdelim.c,v 1.3 2009/10/04 19:43:36 das Exp $");
	29
	30	#include "namespace.h"
	31	#include <os/overflow.h>
	32	#include <sys/param.h>
	33	#include <errno.h>
	34	#include <limits.h>
	35	#include <stdio.h>
	36	#include <stdlib.h>
	37	#include <string.h>
	38	#include "un-namespace.h"
	39
	40	#include "libc_private.h"
	41	#include "local.h"
	42
	43	static inline size_t
	44	p2roundup(size_t n)
	45	{
	46
	47	if (!powerof2(n)) {
	48	n--;
	49	n \|= n >> 1;
	50	n \|= n >> 2;
	51	n \|= n >> 4;
	52	n \|= n >> 8;
	53	n \|= n >> 16;
	54	#if SIZE_T_MAX > 0xffffffffU
	55	n \|= n >> 32;
	56	#endif
	57	n++;
	58	}
	59	return (n);
	60	}
	61
	62	/*
	63	* Expand *linep to hold len bytes (up to SSIZE_MAX + 1).
	64	*/
	65	static inline int
	66	expandtofit(char ** __restrict linep, size_t len, size_t * __restrict capp)
	67	{
	68	char *newline;
	69	size_t newcap;
	70
	71	if (len > (size_t)SSIZE_MAX + 1) {
	72	errno = EOVERFLOW;
	73	return (-1);
	74	}
	75	if (len > *capp) {
	76	if (len == (size_t)SSIZE_MAX + 1) /* avoid overflow */
	77	newcap = (size_t)SSIZE_MAX + 1;
	78	else
	79	newcap = p2roundup(len);
	80	newline = realloc(*linep, newcap);
	81	if (newline == NULL)
	82	return (-1);
	83	*capp = newcap;
	84	*linep = newline;
	85	}
	86	return (0);
	87	}
	88
	89	/*
	90	* Append the src buffer to the *dstp buffer. The buffers are of
	91	* length srclen and *dstlenp, respectively, and dst has space for
	92	* dstlenp bytes. After the call, dstlenp and *dstcapp are updated
	93	* appropriately, and *dstp is reallocated if needed. Returns 0 on
	94	* success, -1 on allocation failure.
	95	*/
	96	static int
	97	sappend(char ** __restrict dstp, size_t * __restrict dstlenp,
	98	size_t * __restrict dstcapp, char * __restrict src, size_t srclen)
	99	{
	100	size_t tmp;
	101
	102	/* avoid overflowing the result length */
	103	if (os_add3_overflow(srclen, *dstlenp, 1, &tmp)) {
	104	errno = EOVERFLOW;
	105	return (-1);
	106	}
	107
	108	/* ensure room for srclen + dstlen + terminating NUL */
	109	if (expandtofit(dstp, tmp, dstcapp))
	110	return (-1);
	111	memcpy(dstp + dstlenp, src, srclen);
	112	*dstlenp += srclen;
	113	return (0);
	114	}
	115
	116	ssize_t
	117	getdelim(char ** __restrict linep, size_t * __restrict linecapp, int delim,
	118	FILE * __restrict fp)
	119	{
	120	u_char *endp;
	121	size_t linelen;
	122
	123	FLOCKFILE(fp);
	124	ORIENT(fp, -1);
	125
	126	if (linep == NULL \|\| linecapp == NULL) {
	127	errno = EINVAL;
	128	goto error;
	129	}
	130
	131	if (*linep == NULL)
	132	*linecapp = 0;
	133
	134	if (fp->_r <= 0 && __srefill(fp)) {
	135	/* If fp is at EOF already, we just need space for the NUL. */
	136	if (__sferror(fp) \|\| expandtofit(linep, 1, linecapp))
	137	goto error;
	138	FUNLOCKFILE(fp);
	139	(*linep)[0] = '\0';
	140	return (-1);
	141	}
	142
	143	linelen = 0;
	144	while ((endp = memchr(fp->_p, delim, fp->_r)) == NULL) {
	145	if (sappend(linep, &linelen, linecapp, fp->_p, fp->_r))
	146	goto error;
	147	if (__srefill(fp)) {
	148	if (__sferror(fp))
	149	goto error;
	150	goto done; /* hit EOF */
	151	}
	152	}
	153	endp++; /* snarf the delimiter, too */
	154	if (sappend(linep, &linelen, linecapp, fp->_p, endp - fp->_p))
	155	goto error;
	156	fp->_r -= endp - fp->_p;
	157	fp->_p = endp;
	158	done:
	159	/* Invariant: linep has space for at least linelen+1 bytes. /
	160	(*linep)[linelen] = '\0';
	161	FUNLOCKFILE(fp);
	162	return (linelen);
	163
	164	error:
	165	fp->_flags \|= __SERR;
	166	FUNLOCKFILE(fp);
	167	return (-1);
	168	}