1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 2009 David Schultz <das@FreeBSD.org> 5 * Copyright (c) 2021 Dell EMC 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 */ 29 30 #include <sys/cdefs.h> 31 __FBSDID("$FreeBSD$"); 32 33 #include "namespace.h" 34 #include <sys/param.h> 35 #include <errno.h> 36 #include <limits.h> 37 #include <stdio.h> 38 #include <stdlib.h> 39 #include <string.h> 40 #include "un-namespace.h" 41 42 #include "libc_private.h" 43 #include "local.h" 44 45 static inline size_t 46 p2roundup(size_t n) 47 { 48 49 if (!powerof2(n)) { 50 n--; 51 n |= n >> 1; 52 n |= n >> 2; 53 n |= n >> 4; 54 n |= n >> 8; 55 n |= n >> 16; 56 #if SIZE_T_MAX > 0xffffffffU 57 n |= n >> 32; 58 #endif 59 n++; 60 } 61 return (n); 62 } 63 64 /* 65 * Expand *linep to hold len bytes (up to SSIZE_MAX + 1). 66 */ 67 static inline int 68 expandtofit(char ** __restrict linep, size_t len, size_t * __restrict capp) 69 { 70 char *newline; 71 size_t newcap; 72 73 if (len > (size_t)SSIZE_MAX + 1) { 74 errno = EOVERFLOW; 75 return (-1); 76 } 77 if (len > *capp) { 78 if (len == (size_t)SSIZE_MAX + 1) /* avoid overflow */ 79 newcap = (size_t)SSIZE_MAX + 1; 80 else 81 newcap = p2roundup(len); 82 newline = realloc(*linep, newcap); 83 if (newline == NULL) 84 return (-1); 85 *capp = newcap; 86 *linep = newline; 87 } 88 return (0); 89 } 90 91 /* 92 * Append the src buffer to the *dstp buffer. The buffers are of 93 * length srclen and *dstlenp, respectively, and dst has space for 94 * *dstlenp bytes. After the call, *dstlenp and *dstcapp are updated 95 * appropriately, and *dstp is reallocated if needed. Returns 0 on 96 * success, -1 on allocation failure. 97 */ 98 static int 99 sappend(char ** __restrict dstp, size_t * __restrict dstlenp, 100 size_t * __restrict dstcapp, char * __restrict src, size_t srclen) 101 { 102 103 /* ensure room for srclen + dstlen + terminating NUL */ 104 if (expandtofit(dstp, srclen + *dstlenp + 1, dstcapp)) 105 return (-1); 106 memcpy(*dstp + *dstlenp, src, srclen); 107 *dstlenp += srclen; 108 return (0); 109 } 110 111 ssize_t 112 getdelim(char ** __restrict linep, size_t * __restrict linecapp, int delim, 113 FILE * __restrict fp) 114 { 115 u_char *endp; 116 size_t linelen; 117 118 FLOCKFILE_CANCELSAFE(fp); 119 ORIENT(fp, -1); 120 121 if (linep == NULL || linecapp == NULL) { 122 errno = EINVAL; 123 goto error; 124 } 125 126 if (*linep == NULL) 127 *linecapp = 0; 128 129 if (fp->_r <= 0 && __srefill(fp)) { 130 /* If fp is at EOF already, we just need space for the NUL. */ 131 if (!__sfeof(fp) || expandtofit(linep, 1, linecapp)) 132 goto error; 133 (*linep)[0] = '\0'; 134 linelen = -1; 135 goto end; 136 } 137 138 linelen = 0; 139 while ((endp = memchr(fp->_p, delim, fp->_r)) == NULL) { 140 if (sappend(linep, &linelen, linecapp, fp->_p, fp->_r)) 141 goto error; 142 errno = 0; 143 if (__srefill(fp)) { 144 if (__sfeof(fp)) 145 goto done; 146 if (errno == EAGAIN) { 147 /* 148 * We need to undo a partial read that has 149 * been placed into linep or we would otherwise 150 * lose it on the next read. 151 */ 152 while (linelen > 0) { 153 if (__ungetc((*linep)[--linelen], 154 fp) == EOF) 155 goto error; 156 } 157 /* 158 * This is not strictly needed but it is 159 * possible a consumer has worked around an 160 * older EAGAIN bug by buffering a partial 161 * return. 162 */ 163 (*linep)[0] = '\0'; 164 } 165 goto error; 166 } 167 } 168 endp++; /* snarf the delimiter, too */ 169 if (sappend(linep, &linelen, linecapp, fp->_p, endp - fp->_p)) 170 goto error; 171 fp->_r -= endp - fp->_p; 172 fp->_p = endp; 173 done: 174 /* Invariant: *linep has space for at least linelen+1 bytes. */ 175 (*linep)[linelen] = '\0'; 176 end: 177 FUNLOCKFILE_CANCELSAFE(); 178 return (linelen); 179 180 error: 181 fp->_flags |= __SERR; 182 linelen = -1; 183 goto end; 184 } 185