1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2009 David Schultz <das@FreeBSD.org>
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29#include <sys/cdefs.h>
30__FBSDID("$FreeBSD$");
31
32#include "namespace.h"
33#include <sys/param.h>
34#include <errno.h>
35#include <limits.h>
36#include <stdio.h>
37#include <stdlib.h>
38#include <string.h>
39#include "un-namespace.h"
40
41#include "libc_private.h"
42#include "local.h"
43
44static inline size_t
45p2roundup(size_t n)
46{
47
48	if (!powerof2(n)) {
49		n--;
50		n |= n >> 1;
51		n |= n >> 2;
52		n |= n >> 4;
53		n |= n >> 8;
54		n |= n >> 16;
55#if SIZE_T_MAX > 0xffffffffU
56		n |= n >> 32;
57#endif
58		n++;
59	}
60	return (n);
61}
62
63/*
64 * Expand *linep to hold len bytes (up to SSIZE_MAX + 1).
65 */
66static inline int
67expandtofit(char ** __restrict linep, size_t len, size_t * __restrict capp)
68{
69	char *newline;
70	size_t newcap;
71
72	if (len > (size_t)SSIZE_MAX + 1) {
73		errno = EOVERFLOW;
74		return (-1);
75	}
76	if (len > *capp) {
77		if (len == (size_t)SSIZE_MAX + 1)	/* avoid overflow */
78			newcap = (size_t)SSIZE_MAX + 1;
79		else
80			newcap = p2roundup(len);
81		newline = realloc(*linep, newcap);
82		if (newline == NULL)
83			return (-1);
84		*capp = newcap;
85		*linep = newline;
86	}
87	return (0);
88}
89
90/*
91 * Append the src buffer to the *dstp buffer. The buffers are of
92 * length srclen and *dstlenp, respectively, and dst has space for
93 * *dstlenp bytes. After the call, *dstlenp and *dstcapp are updated
94 * appropriately, and *dstp is reallocated if needed. Returns 0 on
95 * success, -1 on allocation failure.
96 */
97static int
98sappend(char ** __restrict dstp, size_t * __restrict dstlenp,
99	size_t * __restrict dstcapp, char * __restrict src, size_t srclen)
100{
101
102	/* ensure room for srclen + dstlen + terminating NUL */
103	if (expandtofit(dstp, srclen + *dstlenp + 1, dstcapp))
104		return (-1);
105	memcpy(*dstp + *dstlenp, src, srclen);
106	*dstlenp += srclen;
107	return (0);
108}
109
110ssize_t
111getdelim(char ** __restrict linep, size_t * __restrict linecapp, int delim,
112	 FILE * __restrict fp)
113{
114	u_char *endp;
115	size_t linelen;
116
117	FLOCKFILE_CANCELSAFE(fp);
118	ORIENT(fp, -1);
119
120	if (linep == NULL || linecapp == NULL) {
121		errno = EINVAL;
122		goto error;
123	}
124
125	if (*linep == NULL)
126		*linecapp = 0;
127
128	if (fp->_r <= 0 && __srefill(fp)) {
129		/* If fp is at EOF already, we just need space for the NUL. */
130		if (!__sfeof(fp) || expandtofit(linep, 1, linecapp))
131			goto error;
132		(*linep)[0] = '\0';
133		linelen = -1;
134		goto end;
135	}
136
137	linelen = 0;
138	while ((endp = memchr(fp->_p, delim, fp->_r)) == NULL) {
139		if (sappend(linep, &linelen, linecapp, fp->_p, fp->_r))
140			goto error;
141		if (__srefill(fp)) {
142			if (!__sfeof(fp))
143				goto error;
144			goto done;	/* hit EOF */
145		}
146	}
147	endp++;	/* snarf the delimiter, too */
148	if (sappend(linep, &linelen, linecapp, fp->_p, endp - fp->_p))
149		goto error;
150	fp->_r -= endp - fp->_p;
151	fp->_p = endp;
152done:
153	/* Invariant: *linep has space for at least linelen+1 bytes. */
154	(*linep)[linelen] = '\0';
155end:
156	FUNLOCKFILE_CANCELSAFE();
157	return (linelen);
158
159error:
160	fp->_flags |= __SERR;
161	linelen = -1;
162	goto end;
163}
164