usr/src/cmd/vntsd/write.c

   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  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
  23  * Use is subject to license terms.
  24  */
  25 #pragma ident   "%Z%%M% %I%     %E% SMI"
  26
  27 /*
  28  * write thread - read from vcc console and  write to tcp client. There are one
  29  * writer and multiple readers per console. The first client who connects to
  30  * a console get write access.
  31  * Writer thread writes vcc data to all tcp clients that connected to
  32  * the console.
  33  */
  34
  35 #include <stdio.h>
  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 <poll.h>
  48 #include <syslog.h>
  49 #include <libintl.h>
  50 #include "vntsd.h"
  51 #include "chars.h"
  52
  53 /* handle for writing all clients  */
  54 typedef struct write_buf {
  55         uint_t  sz;         /* data size */
  56         char    *buf;
  57 } write_buf_t;
  58
  59 /*
  60  * check the state of write thread. exit if no more client connects to the
  61  * console.
  62  */
  63 static void
  64 write_chk_status(vntsd_cons_t *consp, int status)
  65 {
  66
  67         if ((consp->status & VNTSD_CONS_DELETED) || (consp->clientpq == NULL)) {
  68                 thr_exit(0);
  69         }
  70
  71         switch (status) {
  72         case VNTSD_STATUS_VCC_IO_ERR:
  73                 assert(consp->group != NULL);
  74                 if (vntsd_vcc_err(consp) != VNTSD_STATUS_CONTINUE) {
  75                         thr_exit(0);
  76                 }
  77                 break;
  78         case VNTSD_STATUS_INTR:
  79                 thr_exit(0);
  80         default:
  81                 break;
  82
  83         }
  84 }
  85
  86 /*
  87  * skip_terminal_null()
  88  * scan terminal null character sequence (0x5e 0x40)
  89  * return number of characters in the buf after skipping terminal null
  90  * sequence. buf size must be at least sz+1.
  91  */
  92 static int
  93 skip_terminal_null(char *buf, int sz)
  94 {
  95         int         i, j;
  96         static int  term_null_seq = 0;
  97
  98         assert(sz >= 0);
  99
 100         if (term_null_seq) {
 101                 /* skip 0x5e previously */
 102                 term_null_seq = 0;
 103
 104                 if (buf[0] != 0x40) {
 105                         /* not terminal null sequence put 0x5e back */
 106                         for (i = sz; i > 0; i--) {
 107                                 buf[i] = buf[i-1];
 108                         }
 109
 110                         buf[0] = 0x5e;
 111
 112                         sz++;
 113                 } else {
 114                         /* skip terminal null sequence */
 115                         sz--;
 116
 117                         if (sz == 0) {
 118                                 return (sz);
 119                         }
 120
 121                         for (i = 0; i < sz; i++) {
 122                                 buf[i] = buf[i+1];
 123                         }
 124                 }
 125         }
 126
 127         for (; ; ) {
 128                 for (i = 0; i < sz; i++) {
 129                         if (buf[i]  == '\0') {
 130                                 return (i);
 131                         }
 132
 133                         if (buf[i] == 0x5e) {
 134                                 /* possible terminal null sequence */
 135                                 if (i == sz -1) {
 136                                         /* last character in buffer */
 137                                         term_null_seq = 1;
 138                                         sz--;
 139                                         buf[i] = 0;
 140                                         return (sz);
 141                                 }
 142
 143                                 if (buf[i+1] == 0x40) {
 144                                         /* found terminal null sequence */
 145                                         sz -= 2;
 146                                         for (j = i; j < sz -i; j++) {
 147                                                 buf[j] = buf[j+2];
 148                                         }
 149                                         break;
 150                                 }
 151
 152                                 if (buf[i+1] == '\0') {
 153                                         buf[i] = 0;
 154                                         term_null_seq = 1;
 155                                         return (i);
 156                                 }
 157
 158                         }
 159                 }
 160
 161                 if (i == sz) {
 162                         /* end of scan */
 163                         return (sz);
 164                 }
 165         }
 166 }
 167
 168 /* read data from vcc */
 169 static int
 170 read_vcc(vntsd_cons_t *consp, char *buf, ssize_t *sz)
 171 {
 172         /* read from vcc */
 173         *sz = read(consp->vcc_fd, buf, VNTSD_MAX_BUF_SIZE);
 174
 175         if (errno == EINTR) {
 176                 return (VNTSD_STATUS_INTR);
 177         }
 178
 179         if ((*sz > 0)) {
 180                 return (VNTSD_SUCCESS);
 181         }
 182         return (VNTSD_STATUS_VCC_IO_ERR);
 183 }
 184
 185 /*
 186  * write to a client
 187  * this function is passed as a parameter to vntsd_que_find.
 188  * for each client that connected to the console, vntsd_que_find
 189  * applies this function.
 190  */
 191 static boolean_t
 192 write_one_client(vntsd_client_t *clientp, write_buf_t *write_buf)
 193 {
 194         int rv;
 195
 196         rv = vntsd_write_client(clientp, write_buf->buf, write_buf->sz);
 197         if (rv != VNTSD_SUCCESS) {
 198                 (void) mutex_lock(&clientp->lock);
 199                 clientp->status |= VNTSD_CLIENT_IO_ERR;
 200                 assert(clientp->cons);
 201                 (void) thr_kill(clientp->cons_tid, NULL);
 202                 (void) mutex_unlock(&clientp->lock);
 203         }
 204         return (B_FALSE);
 205
 206 }
 207
 208 /* vntsd_write_thread() */
 209 void*
 210 vntsd_write_thread(vntsd_cons_t *consp)
 211 {
 212         char            buf[VNTSD_MAX_BUF_SIZE+1];
 213         int             sz;
 214         int             rv;
 215         write_buf_t     write_buf;
 216
 217         D1(stderr, "t@%d vntsd_write@%d\n", thr_self(), consp->vcc_fd);
 218
 219         assert(consp);
 220         write_chk_status(consp, VNTSD_SUCCESS);
 221
 222         for (; ; ) {
 223                 bzero(buf,  VNTSD_MAX_BUF_SIZE +1);
 224
 225                 /* read data */
 226                 rv = read_vcc(consp, buf, &sz);
 227
 228                 write_chk_status(consp, rv);
 229
 230                 if (sz <= 0) {
 231                         continue;
 232                 }
 233
 234                 /* has data */
 235                 if ((sz = skip_terminal_null(buf, sz)) == 0) {
 236                         /* terminal null sequence */
 237                         continue;
 238                 }
 239
 240                 write_buf.sz = sz;
 241                 write_buf.buf = buf;
 242
 243                 /*
 244                  * output data to all clients connected
 245                  * to this console
 246                  */
 247
 248                 (void) mutex_lock(&consp->lock);
 249                 (void) vntsd_que_find(consp->clientpq,
 250                     (compare_func_t)write_one_client, &write_buf);
 251                 (void) mutex_unlock(&consp->lock);
 252
 253                 write_chk_status(consp, VNTSD_SUCCESS);
 254
 255         }
 256
 257         /*NOTREACHED*/
 258         return (NULL);
 259 }