usr.sbin/rtadvd/advcap.c

   1 /*      $NetBSD: advcap.c,v 1.11 2006/03/05 23:47:08 rpaulo Exp $       */
   2 /*      $KAME: advcap.c,v 1.11 2003/05/19 09:46:50 keiichi Exp $        */
   3
   4 /*
   5  * Copyright (c) 1983 The Regents of the University of California.
   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  * 3. Neither the name of the University nor the names of its contributors
  17  *    may be used to endorse or promote products derived from this software
  18  *    without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  */
  32
  33 /*
  34  * remcap - routines for dealing with the remote host data base
  35  *
  36  * derived from termcap
  37  */
  38 #include <sys/types.h>
  39 #include <sys/uio.h>
  40 #include <unistd.h>
  41 #include <fcntl.h>
  42 #include <ctype.h>
  43 #include <stdlib.h>
  44 #include <stdio.h>
  45 #include <syslog.h>
  46 #include <errno.h>
  47 #include <string.h>
  48 #include "pathnames.h"
  49
  50 #ifndef BUFSIZ
  51 #define BUFSIZ          1024
  52 #endif
  53 #define MAXHOP          32              /* max number of tc= indirections */
  54
  55 #define tgetent         agetent
  56 #define tnchktc         anchktc
  57 #define tnamatch        anamatch
  58 #define tgetnum         agetnum
  59 #define tgetflag        agetflag
  60 #define tgetstr         agetstr
  61
  62 #if 0
  63 #define V_TERMCAP       "REMOTE"
  64 #define V_TERM          "HOST"
  65 #endif
  66
  67 char    *RM;
  68
  69 /*
  70  * termcap - routines for dealing with the terminal capability data base
  71  *
  72  * BUG:         Should use a "last" pointer in tbuf, so that searching
  73  *              for capabilities alphabetically would not be a n**2/2
  74  *              process when large numbers of capabilities are given.
  75  * Note:        If we add a last pointer now we will screw up the
  76  *              tc capability. We really should compile termcap.
  77  *
  78  * Essentially all the work here is scanning and decoding escapes
  79  * in string capabilities.  We don't use stdio because the editor
  80  * doesn't, and because living w/o it is not hard.
  81  */
  82
  83 static  char *tbuf;
  84 static  int hopcount;   /* detect infinite loops in termcap, init 0 */
  85
  86 static  char *remotefile;
  87
  88 extern char *conffile;
  89
  90 int tgetent __P((char *, char *));
  91 int getent __P((char *, char *, char *));
  92 int tnchktc __P((void));
  93 int tnamatch __P((char *));
  94 static char *tskip __P((char *));
  95 int64_t tgetnum __P((char *));
  96 int tgetflag __P((char *));
  97 char *tgetstr __P((char *, char **));
  98 static char *tdecode __P((char *, char **));
  99
 100 /*
 101  * Get an entry for terminal name in buffer bp,
 102  * from the termcap file.  Parse is very rudimentary;
 103  * we just notice escaped newlines.
 104  */
 105 int
 106 tgetent(bp, name)
 107         char *bp, *name;
 108 {
 109         char *cp;
 110
 111         remotefile = cp = conffile ? conffile : _PATH_RTADVDCONF;
 112         return (getent(bp, name, cp));
 113 }
 114
 115 int
 116 getent(bp, name, cp)
 117         char *bp, *name, *cp;
 118 {
 119         int c;
 120         int i = 0, cnt = 0;
 121         char ibuf[BUFSIZ];
 122         int tf;
 123
 124         tbuf = bp;
 125         tf = 0;
 126         /*
 127          * TERMCAP can have one of two things in it. It can be the
 128          * name of a file to use instead of /etc/termcap. In this
 129          * case it better start with a "/". Or it can be an entry to
 130          * use so we don't have to read the file. In this case it
 131          * has to already have the newlines crunched out.
 132          */
 133         if (cp && *cp) {
 134                 tf = open(RM = cp, O_RDONLY);
 135         }
 136         if (tf < 0) {
 137                 syslog(LOG_INFO,
 138                        "<%s> open: %s", __func__, strerror(errno));
 139                 return (-2);
 140         }
 141         for (;;) {
 142                 cp = bp;
 143                 for (;;) {
 144                         if (i == cnt) {
 145                                 cnt = read(tf, ibuf, BUFSIZ);
 146                                 if (cnt <= 0) {
 147                                         close(tf);
 148                                         return (0);
 149                                 }
 150                                 i = 0;
 151                         }
 152                         c = ibuf[i++];
 153                         if (c == '\n') {
 154                                 if (cp > bp && cp[-1] == '\\') {
 155                                         cp--;
 156                                         continue;
 157                                 }
 158                                 break;
 159                         }
 160                         if (cp >= bp + BUFSIZ) {
 161                                 write(2,"Remcap entry too long\n", 23);
 162                                 break;
 163                         } else
 164                                 *cp++ = c;
 165                 }
 166                 *cp = 0;
 167
 168                 /*
 169                  * The real work for the match.
 170                  */
 171                 if (tnamatch(name)) {
 172                         close(tf);
 173                         return (tnchktc());
 174                 }
 175         }
 176 }
 177
 178 /*
 179  * tnchktc: check the last entry, see if it's tc=xxx. If so,
 180  * recursively find xxx and append that entry (minus the names)
 181  * to take the place of the tc=xxx entry. This allows termcap
 182  * entries to say "like an HP2621 but doesn't turn on the labels".
 183  * Note that this works because of the left to right scan.
 184  */
 185 int
 186 tnchktc()
 187 {
 188         char *p, *q;
 189         char tcname[16];        /* name of similar terminal */
 190         char tcbuf[BUFSIZ];
 191         char *holdtbuf = tbuf;
 192         int l;
 193
 194         p = tbuf + strlen(tbuf) - 2;    /* before the last colon */
 195         while (*--p != ':')
 196                 if (p < tbuf) {
 197                         write(2, "Bad remcap entry\n", 18);
 198                         return (0);
 199                 }
 200         p++;
 201         /* p now points to beginning of last field */
 202         if (p[0] != 't' || p[1] != 'c')
 203                 return (1);
 204         strlcpy(tcname, p + 3, sizeof tcname);
 205         q = tcname;
 206         while (*q && *q != ':')
 207                 q++;
 208         *q = 0;
 209         if (++hopcount > MAXHOP) {
 210                 write(2, "Infinite tc= loop\n", 18);
 211                 return (0);
 212         }
 213         if (getent(tcbuf, tcname, remotefile) != 1) {
 214                 return (0);
 215         }
 216         for (q = tcbuf; *q++ != ':'; )
 217                 ;
 218         l = p - holdtbuf + strlen(q);
 219         if (l > BUFSIZ) {
 220                 write(2, "Remcap entry too long\n", 23);
 221                 q[BUFSIZ - (p-holdtbuf)] = 0;
 222         }
 223         strcpy(p, q);
 224         tbuf = holdtbuf;
 225         return (1);
 226 }
 227
 228 /*
 229  * Tnamatch deals with name matching.  The first field of the termcap
 230  * entry is a sequence of names separated by |'s, so we compare
 231  * against each such name.  The normal : terminator after the last
 232  * name (before the first field) stops us.
 233  */
 234 int
 235 tnamatch(np)
 236         char *np;
 237 {
 238         char *Np, *Bp;
 239
 240         Bp = tbuf;
 241         if (*Bp == '#')
 242                 return (0);
 243         for (;;) {
 244                 for (Np = np; *Np && *Bp == *Np; Bp++, Np++)
 245                         continue;
 246                 if (*Np == 0 && (*Bp == '|' || *Bp == ':' || *Bp == 0))
 247                         return (1);
 248                 while (*Bp && *Bp != ':' && *Bp != '|')
 249                         Bp++;
 250                 if (*Bp == 0 || *Bp == ':')
 251                         return (0);
 252                 Bp++;
 253         }
 254 }
 255
 256 /*
 257  * Skip to the next field.  Notice that this is very dumb, not
 258  * knowing about \: escapes or any such.  If necessary, :'s can be put
 259  * into the termcap file in octal.
 260  */
 261 static char *
 262 tskip(bp)
 263         char *bp;
 264 {
 265         int dquote;
 266
 267         dquote = 0;
 268         while (*bp) {
 269                 switch (*bp) {
 270                 case ':':
 271                         if (!dquote)
 272                                 goto breakbreak;
 273                         else
 274                                 bp++;
 275                         break;
 276                 case '\\':
 277                         bp++;
 278                         if (isdigit((unsigned char)*bp)) {
 279                                 while (isdigit((unsigned char)*bp++))
 280                                         ;
 281                         } else
 282                                 bp++;
 283                 case '"':
 284                         dquote = (dquote ? 0 : 1);
 285                         bp++;
 286                         break;
 287                 default:
 288                         bp++;
 289                         break;
 290                 }
 291         }
 292 breakbreak:
 293         if (*bp == ':')
 294                 bp++;
 295         return (bp);
 296 }
 297
 298 /*
 299  * Return the (numeric) option id.
 300  * Numeric options look like
 301  *      li#80
 302  * i.e. the option string is separated from the numeric value by
 303  * a # character.  If the option is not found we return -1.
 304  * Note that we handle octal numbers beginning with 0.
 305  */
 306 int64_t
 307 tgetnum(id)
 308         char *id;
 309 {
 310         int64_t i;
 311         int base;
 312         char *bp = tbuf;
 313
 314         for (;;) {
 315                 bp = tskip(bp);
 316                 if (*bp == 0)
 317                         return (-1);
 318                 if (strncmp(bp, id, strlen(id)) != 0)
 319                         continue;
 320                 bp += strlen(id);
 321                 if (*bp == '@')
 322                         return (-1);
 323                 if (*bp != '#')
 324                         continue;
 325                 bp++;
 326                 base = 10;
 327                 if (*bp == '0')
 328                         base = 8;
 329                 i = 0;
 330                 while (isdigit((unsigned char)*bp))
 331                         i *= base, i += *bp++ - '0';
 332                 return (i);
 333         }
 334 }
 335
 336 /*
 337  * Handle a flag option.
 338  * Flag options are given "naked", i.e. followed by a : or the end
 339  * of the buffer.  Return 1 if we find the option, or 0 if it is
 340  * not given.
 341  */
 342 int
 343 tgetflag(id)
 344         char *id;
 345 {
 346         char *bp = tbuf;
 347
 348         for (;;) {
 349                 bp = tskip(bp);
 350                 if (!*bp)
 351                         return (0);
 352                 if (strncmp(bp, id, strlen(id)) == 0) {
 353                         bp += strlen(id);
 354                         if (!*bp || *bp == ':')
 355                                 return (1);
 356                         else if (*bp == '@')
 357                                 return (0);
 358                 }
 359         }
 360 }
 361
 362 /*
 363  * Get a string valued option.
 364  * These are given as
 365  *      cl=^Z
 366  * Much decoding is done on the strings, and the strings are
 367  * placed in area, which is a ref parameter which is updated.
 368  * No checking on area overflow.
 369  */
 370 char *
 371 tgetstr(id, area)
 372         char *id, **area;
 373 {
 374         char *bp = tbuf;
 375
 376         for (;;) {
 377                 bp = tskip(bp);
 378                 if (!*bp)
 379                         return (0);
 380                 if (strncmp(bp, id, strlen(id)) != 0)
 381                         continue;
 382                 bp += strlen(id);
 383                 if (*bp == '@')
 384                         return (0);
 385                 if (*bp != '=')
 386                         continue;
 387                 bp++;
 388                 return (tdecode(bp, area));
 389         }
 390 }
 391
 392 /*
 393  * Tdecode does the grung work to decode the
 394  * string capability escapes.
 395  */
 396 static char *
 397 tdecode(str, area)
 398         char *str;
 399         char **area;
 400 {
 401         char *cp;
 402         int c;
 403         char *dp;
 404         int i;
 405         char term;
 406
 407         term = ':';
 408         cp = *area;
 409 again:
 410         if (*str == '"') {
 411                 term = '"';
 412                 str++;
 413         }
 414         while ((c = *str++) && c != term) {
 415                 switch (c) {
 416
 417                 case '^':
 418                         c = *str++ & 037;
 419                         break;
 420
 421                 case '\\':
 422                         dp = "E\033^^\\\\::n\nr\rt\tb\bf\f\"\"";
 423                         c = *str++;
 424 nextc:
 425                         if (*dp++ == c) {
 426                                 c = *dp++;
 427                                 break;
 428                         }
 429                         dp++;
 430                         if (*dp)
 431                                 goto nextc;
 432                         if (isdigit((unsigned char)c)) {
 433                                 c -= '0', i = 2;
 434                                 do
 435                                         c <<= 3, c |= *str++ - '0';
 436                                 while (--i && isdigit((unsigned char)*str));
 437                         }
 438                         break;
 439                 }
 440                 *cp++ = c;
 441         }
 442         if (c == term && term != ':') {
 443                 term = ':';
 444                 goto again;
 445         }
 446         *cp++ = 0;
 447         str = *area;
 448         *area = cp;
 449         return (str);
 450 }