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 #pragma ident "%Z%%M% %I% %E% SMI" 22 23 /* 24 * Copyright 2006 Sun Microsystems, Inc. All rights reserved. 25 * Use is subject to license terms. 26 */ 27 28 /* 29 * read thread - Read from tcp client and write to vcc driver. There are one 30 * writer and multiple readers per console. The first client who connects to 31 * a console get write access. An error message is returned to readers if they 32 * attemp to input commands. Read thread accepts special daemon commands from 33 * all clients. 34 */ 35 36 #include <stdio.h> 37 #include <stdlib.h> 38 #include <string.h> 39 #include <unistd.h> 40 #include <sys/types.h> 41 #include <sys/socket.h> 42 #include <netinet/in.h> 43 #include <thread.h> 44 #include <synch.h> 45 #include <signal.h> 46 #include <assert.h> 47 #include <ctype.h> 48 #include <syslog.h> 49 #include <libintl.h> 50 #include "vntsd.h" 51 #include "chars.h" 52 53 /* write_vcc() - write to vcc virtual console */ 54 static int 55 write_vcc(vntsd_client_t *clientp, char c) 56 { 57 int n; 58 59 60 assert(clientp); 61 assert(clientp->cons); 62 63 if (c == 0) { 64 return (VNTSD_SUCCESS); 65 } 66 n = write(clientp->cons->vcc_fd, &c, 1); 67 68 if (n < 0) { 69 /* write error */ 70 if (errno == EINTR) { 71 return (vntsd_cons_chk_intr(clientp)); 72 } 73 74 return (VNTSD_STATUS_VCC_IO_ERR); 75 } 76 77 assert(n != 0); 78 return (VNTSD_SUCCESS); 79 80 } 81 82 /* 83 * acquire_writer() the client is going to be writer. 84 * insert the client to the head of the console client queue. 85 */ 86 static int 87 acquire_writer(vntsd_client_t *clientp) 88 { 89 vntsd_cons_t *consp; 90 vntsd_client_t *writerp; 91 int rv; 92 93 D1(stderr, "t@%d:acuire_writer :client@%d\n", thr_self(), 94 clientp->sockfd); 95 96 assert(clientp != NULL); 97 consp = clientp->cons; 98 99 assert(consp); 100 101 (void) mutex_lock(&consp->lock); 102 103 assert(consp->clientpq != NULL); 104 if (consp->clientpq->handle == clientp) { 105 /* clientp is a writer already */ 106 (void) mutex_unlock(&consp->lock); 107 return (VNTSD_SUCCESS); 108 } 109 110 /* current writer */ 111 writerp = (vntsd_client_t *)(consp->clientpq->handle); 112 113 (void) mutex_lock(&writerp->lock); 114 115 rv = vntsd_que_rm(&(consp->clientpq), clientp); 116 assert(rv == VNTSD_SUCCESS); 117 118 (void) mutex_lock(&clientp->lock); 119 120 /* move client to be first in the console queue */ 121 consp->clientpq->handle = clientp; 122 123 /* move previous writer to be the second in the queue */ 124 rv = vntsd_que_insert_after(consp->clientpq, clientp, writerp); 125 126 (void) mutex_unlock(&consp->lock); 127 (void) mutex_unlock(&writerp->lock); 128 (void) mutex_unlock(&clientp->lock); 129 130 if (rv != VNTSD_SUCCESS) { 131 return (rv); 132 } 133 134 /* write warning message to the writer */ 135 136 if ((rv = vntsd_write_line(writerp, 137 gettext("Warning: Console connection forced into read-only mode"))) 138 != VNTSD_SUCCESS) { 139 return (rv); 140 } 141 142 return (VNTSD_SUCCESS); 143 } 144 145 /* interrupt handler */ 146 int 147 vntsd_cons_chk_intr(vntsd_client_t *clientp) 148 { 149 150 if (clientp->status & VNTSD_CLIENT_TIMEOUT) { 151 return (VNTSD_STATUS_CLIENT_QUIT); 152 } 153 if (clientp->status & VNTSD_CLIENT_CONS_DELETED) { 154 return (VNTSD_STATUS_RESELECT_CONS); 155 } 156 157 if (clientp->status & VNTSD_CLIENT_IO_ERR) { 158 return (VNTSD_STATUS_CLIENT_QUIT); 159 } 160 return (VNTSD_STATUS_CONTINUE); 161 } 162 163 /* read from client */ 164 static int 165 read_char(vntsd_client_t *clientp, char *c) 166 { 167 int rv; 168 169 for (; ; ) { 170 171 rv = vntsd_read_data(clientp, c); 172 173 switch (rv) { 174 case VNTSD_STATUS_CONTINUE: 175 break; 176 177 case VNTSD_STATUS_ACQUIRE_WRITER: 178 rv = acquire_writer(clientp); 179 if (rv != VNTSD_SUCCESS) { 180 return (rv); 181 } 182 break; 183 default: 184 return (rv); 185 } 186 } 187 } 188 189 /* vntsd_read worker */ 190 int 191 vntsd_read(vntsd_client_t *clientp) 192 { 193 char c; 194 int rv; 195 196 197 assert(clientp); 198 D3(stderr, "t@%d vntsd_read@%d\n", thr_self(), clientp->sockfd); 199 200 for (; ; ) { 201 202 /* client input */ 203 rv = read_char(clientp, &c); 204 205 if (rv == VNTSD_STATUS_INTR) { 206 rv = vntsd_cons_chk_intr(clientp); 207 } 208 209 if (rv != VNTSD_SUCCESS) { 210 return (rv); 211 } 212 213 assert(clientp->cons); 214 if (clientp->cons->clientpq->handle != clientp) { 215 /* reader - print error message */ 216 if ((c != CR) && (c != LF)) { 217 rv = vntsd_write_line(clientp, 218 gettext(VNTSD_NO_WRITE_ACCESS_MSG)); 219 220 /* check errors and may exit */ 221 if (rv == VNTSD_STATUS_INTR) { 222 rv = vntsd_cons_chk_intr(clientp); 223 } 224 225 if (rv != VNTSD_SUCCESS) { 226 return (rv); 227 } 228 229 } 230 231 continue; 232 } 233 234 rv = vntsd_ctrl_cmd(clientp, c); 235 236 switch (rv) { 237 case VNTSD_STATUS_CONTINUE: 238 continue; 239 break; 240 case VNTSD_STATUS_INTR: 241 rv = vntsd_cons_chk_intr(clientp); 242 if (rv != VNTSD_SUCCESS) { 243 return (rv); 244 } 245 break; 246 case VNTSD_SUCCESS: 247 break; 248 default: 249 return (rv); 250 } 251 252 /* write to vcc */ 253 rv = write_vcc(clientp, c); 254 if (rv == VNTSD_STATUS_INTR) { 255 rv = vntsd_cons_chk_intr(clientp); 256 } 257 if (rv != VNTSD_SUCCESS) { 258 return (rv); 259 } 260 261 } 262 263 /*NOTREACHED*/ 264 return (NULL); 265 } 266