1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 22 /* 23 * Copyright 2008 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 /* Copyright (c) 1988 AT&T */ 28 /* All Rights Reserved */ 29 30 #pragma ident "%Z%%M% %I% %E% SMI" 31 32 33 #define _LARGEFILE64_SOURCE 1 34 35 #include "lint.h" 36 #include "file64.h" 37 #include <stdlib.h> 38 #include <stdio.h> 39 #include <sys/types.h> 40 #include <sys/stat.h> 41 #include "stdiom.h" 42 43 /* 44 * If buffer space has been pre-allocated use it otherwise malloc space. 45 * PUSHBACK causes the base pointer to be bumped forward. At least 4 bytes 46 * of pushback are required to meet international specifications. 47 * Extra space at the end of the buffer allows for synchronization problems. 48 * If malloc() fails stdio bails out; assumption being the system is in trouble. 49 * Associate a buffer with stream; return NULL on error. 50 */ 51 Uchar * 52 _findbuf(FILE *iop) 53 { 54 int fd = GET_FD(iop); 55 Uchar *buf; 56 int size = BUFSIZ; 57 Uchar *endbuf; 58 int tty = -1; 59 60 struct stat64 stbuf; /* used to get file system block size */ 61 62 if (iop->_flag & _IONBF) /* need a small buffer, at least */ 63 { 64 trysmall:; 65 size = _SMBFSZ - PUSHBACK; 66 if (fd < _NFILE) 67 buf = _smbuf[fd]; 68 else if ((buf = (Uchar *)malloc(_SMBFSZ * sizeof (Uchar))) != 69 NULL) 70 iop->_flag |= _IOMYBUF; 71 } 72 #ifndef _STDIO_ALLOCATE 73 else if (fd < 2 && (tty = isatty(fd))) { 74 buf = (fd == 0) ? _sibuf : _sobuf; /* special buffer */ 75 /* for std{in,out} */ 76 } 77 #endif 78 else { 79 /* 80 * The operating system can tell us the 81 * right size for a buffer; 82 * avoid 0-size buffers as returned for some 83 * special files (doors) 84 */ 85 if (fstat64(fd, &stbuf) == 0 && stbuf.st_blksize > 0) 86 size = stbuf.st_blksize; 87 88 if ((buf = (Uchar *)malloc(sizeof (Uchar)*(size+_SMBFSZ))) != 89 NULL) 90 iop->_flag |= _IOMYBUF; 91 else 92 goto trysmall; 93 } 94 if (buf == NULL) 95 return (NULL); /* malloc() failed */ 96 iop->_base = buf + PUSHBACK; /* bytes for pushback */ 97 iop->_ptr = buf + PUSHBACK; 98 endbuf = iop->_base + size; 99 _setbufend(iop, endbuf); 100 if (!(iop->_flag & _IONBF) && ((tty != -1) ? tty : isatty(fd))) 101 iop->_flag |= _IOLBF; 102 return (endbuf); 103 } 104