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 #include "priv_stdio.h" 41 42 static inline size_t 43 p2roundup(size_t n) 44 { 45 46 if (!powerof2(n)) { 47 n--; 48 n |= n >> 1; 49 n |= n >> 2; 50 n |= n >> 4; 51 n |= n >> 8; 52 n |= n >> 16; 53 #if SIZE_T_MAX > 0xffffffffU 54 n |= n >> 32; 55 #endif 56 n++; 57 } 58 return (n); 59 } 60 61 /* 62 * Expand *linep to hold len bytes (up to SSIZE_MAX + 1). 63 */ 64 static inline int 65 expandtofit(char ** __restrict linep, size_t len, size_t * __restrict capp) 66 { 67 char *newline; 68 size_t newcap; 69 70 if (len > (size_t)SSIZE_MAX + 1) { 71 errno = EOVERFLOW; 72 return (-1); 73 } 74 if (len > *capp) { 75 if (len == (size_t)SSIZE_MAX + 1) /* avoid overflow */ 76 newcap = (size_t)SSIZE_MAX + 1; 77 else 78 newcap = p2roundup(len); 79 newline = realloc(*linep, newcap); 80 if (newline == NULL) 81 return (-1); 82 *capp = newcap; 83 *linep = newline; 84 } 85 return (0); 86 } 87 88 /* 89 * Append the src buffer to the *dstp buffer. The buffers are of 90 * length srclen and *dstlenp, respectively, and dst has space for 91 * *dstlenp bytes. After the call, *dstlenp and *dstcapp are updated 92 * appropriately, and *dstp is reallocated if needed. Returns 0 on 93 * success, -1 on allocation failure. 94 */ 95 static int 96 sappend(char ** __restrict dstp, size_t * __restrict dstlenp, 97 size_t * __restrict dstcapp, char * __restrict src, size_t srclen) 98 { 99 100 /* ensure room for srclen + dstlen + terminating NUL */ 101 if (expandtofit(dstp, srclen + *dstlenp + 1, dstcapp)) 102 return (-1); 103 memcpy(*dstp + *dstlenp, src, srclen); 104 *dstlenp += srclen; 105 return (0); 106 } 107 108 ssize_t 109 getdelim(char ** __restrict linep, size_t * __restrict linecapp, int delim, 110 FILE * __restrict fp) 111 { 112 u_char *endp; 113 size_t linelen; 114 115 FLOCKFILE(fp); 116 ORIENT(fp, -1); 117 118 if (linep == NULL || linecapp == NULL) { 119 errno = EINVAL; 120 goto error; 121 } 122 123 if (*linecapp == 0) 124 *linep = NULL; 125 126 if (fp->pub._r <= 0 && __srefill(fp)) { 127 /* If fp is at EOF already, we just need space for the NUL. */ 128 if (__sferror(fp) || expandtofit(linep, 1, linecapp)) 129 goto error; 130 FUNLOCKFILE(fp); 131 (*linep)[0] = '\0'; 132 return (-1); 133 } 134 135 linelen = 0; 136 while ((endp = memchr(fp->pub._p, delim, fp->pub._r)) == NULL) { 137 if (sappend(linep, &linelen, linecapp, fp->pub._p, fp->pub._r)) 138 goto error; 139 if (__srefill(fp)) { 140 if (__sferror(fp)) 141 goto error; 142 goto done; /* hit EOF */ 143 } 144 } 145 endp++; /* snarf the delimiter, too */ 146 if (sappend(linep, &linelen, linecapp, fp->pub._p, endp - fp->pub._p)) 147 goto error; 148 fp->pub._r -= endp - fp->pub._p; 149 fp->pub._p = endp; 150 done: 151 /* Invariant: *linep has space for at least linelen+1 bytes. */ 152 (*linep)[linelen] = '\0'; 153 FUNLOCKFILE(fp); 154 return (linelen); 155 156 error: 157 fp->pub._flags |= __SERR; 158 FUNLOCKFILE(fp); 159 return (-1); 160 } 161