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 "namespace.h" 31 #include <sys/param.h> 32 #include <errno.h> 33 #include <limits.h> 34 #include <stdio.h> 35 #include <stdlib.h> 36 #include <string.h> 37 #include "un-namespace.h" 38 39 #include "libc_private.h" 40 #include "local.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_CANCELSAFE(fp); 116 ORIENT(fp, -1); 117 118 if (linep == NULL || linecapp == NULL) { 119 errno = EINVAL; 120 goto error; 121 } 122 123 if (*linep == NULL) 124 *linecapp = 0; 125 126 if (fp->_r <= 0 && __srefill(fp)) { 127 /* If fp is at EOF already, we just need space for the NUL. */ 128 if (!__sfeof(fp) || expandtofit(linep, 1, linecapp)) 129 goto error; 130 (*linep)[0] = '\0'; 131 linelen = -1; 132 goto end; 133 } 134 135 linelen = 0; 136 while ((endp = memchr(fp->_p, delim, fp->_r)) == NULL) { 137 if (sappend(linep, &linelen, linecapp, fp->_p, fp->_r)) 138 goto error; 139 errno = 0; 140 if (__srefill(fp)) { 141 if (__sfeof(fp)) 142 goto done; 143 if (errno == EAGAIN) { 144 /* 145 * We need to undo a partial read that has 146 * been placed into linep or we would otherwise 147 * lose it on the next read. 148 */ 149 while (linelen > 0) { 150 if (__ungetc((*linep)[--linelen], 151 fp) == EOF) 152 goto error; 153 } 154 /* 155 * This is not strictly needed but it is 156 * possible a consumer has worked around an 157 * older EAGAIN bug by buffering a partial 158 * return. 159 */ 160 (*linep)[0] = '\0'; 161 } 162 goto error; 163 } 164 } 165 endp++; /* snarf the delimiter, too */ 166 if (sappend(linep, &linelen, linecapp, fp->_p, endp - fp->_p)) 167 goto error; 168 fp->_r -= endp - fp->_p; 169 fp->_p = endp; 170 done: 171 /* Invariant: *linep has space for at least linelen+1 bytes. */ 172 (*linep)[linelen] = '\0'; 173 end: 174 FUNLOCKFILE_CANCELSAFE(); 175 return (linelen); 176 177 error: 178 fp->_flags |= __SERR; 179 linelen = -1; 180 goto end; 181 } 182