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 * $FreeBSD: src/lib/libc/stdio/getdelim.c,v 1.2 2009/04/06 13:50:04 das Exp $ 27 */ 28 29 #include "namespace.h" 30 #include <sys/param.h> 31 #include <errno.h> 32 #include <limits.h> 33 #include <stdio.h> 34 #include <stdlib.h> 35 #include <string.h> 36 #include "un-namespace.h" 37 38 #include "libc_private.h" 39 #include "local.h" 40 41 static inline size_t 42 p2roundup(size_t n) 43 { 44 45 if (!powerof2(n)) { 46 n--; 47 n |= n >> 1; 48 n |= n >> 2; 49 n |= n >> 4; 50 n |= n >> 8; 51 n |= n >> 16; 52 #if SIZE_T_MAX > 0xffffffffU 53 n |= n >> 32; 54 #endif 55 n++; 56 } 57 return (n); 58 } 59 60 /* 61 * Expand *linep to hold len bytes (up to SSIZE_MAX + 1). 62 */ 63 static inline int 64 expandtofit(char ** __restrict linep, size_t len, size_t * __restrict capp) 65 { 66 char *newline; 67 size_t newcap; 68 69 if (len > (size_t)SSIZE_MAX + 1) { 70 errno = EOVERFLOW; 71 return (-1); 72 } 73 if (len > *capp) { 74 if (len == (size_t)SSIZE_MAX + 1) /* avoid overflow */ 75 newcap = (size_t)SSIZE_MAX + 1; 76 else 77 newcap = p2roundup(len); 78 newline = realloc(*linep, newcap); 79 if (newline == NULL) 80 return (-1); 81 *capp = newcap; 82 *linep = newline; 83 } 84 return (0); 85 } 86 87 /* 88 * Append the src buffer to the *dstp buffer. The buffers are of 89 * length srclen and *dstlenp, respectively, and dst has space for 90 * *dstlenp bytes. After the call, *dstlenp and *dstcapp are updated 91 * appropriately, and *dstp is reallocated if needed. Returns 0 on 92 * success, -1 on allocation failure. 93 */ 94 static int 95 sappend(char ** __restrict dstp, size_t * __restrict dstlenp, 96 size_t * __restrict dstcapp, char * __restrict src, size_t srclen) 97 { 98 99 /* ensure room for srclen + dstlen + terminating NUL */ 100 if (expandtofit(dstp, srclen + *dstlenp + 1, dstcapp)) 101 return (-1); 102 memcpy(*dstp + *dstlenp, src, srclen); 103 *dstlenp += srclen; 104 return (0); 105 } 106 107 ssize_t 108 getdelim(char ** __restrict linep, size_t * __restrict linecapp, int delim, 109 FILE * __restrict fp) 110 { 111 u_char *endp; 112 size_t linelen; 113 114 FLOCKFILE(fp); 115 ORIENT(fp, -1); 116 117 if (linep == NULL || linecapp == NULL) { 118 errno = EINVAL; 119 goto error; 120 } 121 122 if (*linep == NULL) 123 *linecapp = 0; 124 125 if (fp->pub._r <= 0 && __srefill(fp)) { 126 /* If fp is at EOF already, we just need space for the NUL. */ 127 if (__sferror(fp) || expandtofit(linep, 1, linecapp)) 128 goto error; 129 FUNLOCKFILE(fp); 130 (*linep)[0] = '\0'; 131 return (-1); 132 } 133 134 linelen = 0; 135 while ((endp = memchr(fp->pub._p, delim, fp->pub._r)) == NULL) { 136 if (sappend(linep, &linelen, linecapp, fp->pub._p, fp->pub._r)) 137 goto error; 138 if (__srefill(fp)) { 139 if (__sferror(fp)) 140 goto error; 141 goto done; /* hit EOF */ 142 } 143 } 144 endp++; /* snarf the delimiter, too */ 145 if (sappend(linep, &linelen, linecapp, fp->pub._p, endp - fp->pub._p)) 146 goto error; 147 fp->pub._r -= endp - fp->pub._p; 148 fp->pub._p = endp; 149 done: 150 /* Invariant: *linep has space for at least linelen+1 bytes. */ 151 (*linep)[linelen] = '\0'; 152 FUNLOCKFILE(fp); 153 return (linelen); 154 155 error: 156 fp->pub._flags |= __SERR; 157 FUNLOCKFILE(fp); 158 return (-1); 159 } 160