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, Version 1.0 only 6 * (the "License"). You may not use this file except in compliance 7 * with the License. 8 * 9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10 * or http://www.opensolaris.org/os/licensing. 11 * See the License for the specific language governing permissions 12 * and limitations under the License. 13 * 14 * When distributing Covered Code, include this CDDL HEADER in each 15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16 * If applicable, add the following below this CDDL HEADER, with the 17 * fields enclosed by brackets "[]" replaced with your own identifying 18 * information: Portions Copyright [yyyy] [name of copyright owner] 19 * 20 * CDDL HEADER END 21 */ 22 /* 23 * Copyright (c) 1997-2001 by Sun Microsystems, Inc. 24 * All rights reserved. 25 */ 26 27 #pragma ident "%Z%%M% %I% %E% SMI" 28 29 /* 30 * Log I/O Backend 31 * 32 * This backend provides the ability to form a T in an iob's output routine. 33 * We use this capability to provide interactive session logging. We create 34 * a log i/o and give it a pointer to another i/o backend representing the 35 * log file, and then stack this on top of the existing stdio i/o backend. 36 * As each write occurs, the log i/o writes to the log file, and also passes 37 * the write request along to io->io_next. 38 */ 39 40 #include <mdb/mdb_modapi.h> 41 #include <mdb/mdb_err.h> 42 #include <mdb/mdb_io_impl.h> 43 #include <mdb/mdb.h> 44 45 static ssize_t 46 logio_read(mdb_io_t *io, void *buf, size_t nbytes) 47 { 48 mdb_io_t *logio = io->io_data; 49 ssize_t rbytes; 50 51 if (io->io_next != NULL) { 52 rbytes = IOP_READ(io->io_next, buf, nbytes); 53 54 if (rbytes > 0) { 55 (void) IOP_WRITE(logio, mdb.m_prompt, mdb.m_promptlen); 56 (void) IOP_WRITE(logio, buf, rbytes); 57 } 58 59 return (rbytes); 60 } 61 62 return (-1); 63 } 64 65 static ssize_t 66 logio_write(mdb_io_t *io, const void *buf, size_t nbytes) 67 { 68 mdb_io_t *logio = io->io_data; 69 ssize_t wbytes; 70 71 if (io->io_next != NULL) { 72 wbytes = IOP_WRITE(io->io_next, buf, nbytes); 73 74 if (wbytes > 0) 75 (void) IOP_WRITE(logio, buf, wbytes); 76 77 return (wbytes); 78 } 79 80 return (-1); 81 } 82 83 static void 84 logio_close(mdb_io_t *io) 85 { 86 mdb_io_rele(io->io_data); 87 } 88 89 static const char * 90 logio_name(mdb_io_t *io) 91 { 92 if (io->io_next != NULL) 93 return (IOP_NAME(io->io_next)); 94 95 return ("(log)"); 96 } 97 98 static const mdb_io_ops_t logio_ops = { 99 logio_read, 100 logio_write, 101 no_io_seek, 102 no_io_ctl, 103 logio_close, 104 logio_name, 105 no_io_link, 106 no_io_unlink, 107 no_io_setattr, 108 no_io_suspend, 109 no_io_resume 110 }; 111 112 mdb_io_t * 113 mdb_logio_create(mdb_io_t *logio) 114 { 115 mdb_io_t *io = mdb_alloc(sizeof (mdb_io_t), UM_SLEEP); 116 117 io->io_ops = &logio_ops; 118 io->io_data = mdb_io_hold(logio); 119 io->io_next = NULL; 120 io->io_refcnt = 0; 121 122 return (io); 123 } 124