usr.sbin/rtadvd/advcap.c

   1 /*      $FreeBSD$       */
   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  * 4. 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(char *, char *);
  91 int getent(char *, char *, char *);
  92 int tnchktc(void);
  93 int tnamatch(char *);
  94 static char *tskip(char *);
  95 int64_t tgetnum(char *);
  96 int tgetflag(char *);
  97 char *tgetstr(char *, char **);
  98 static char *tdecode(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(STDERR_FILENO, "Remcap entry too long\n",
 162                                       23);
 163                                 break;
 164                         } else
 165                                 *cp++ = c;
 166                 }
 167                 *cp = 0;
 168
 169                 /*
 170                  * The real work for the match.
 171                  */
 172                 if (tnamatch(name)) {
 173                         close(tf);
 174                         return (tnchktc());
 175                 }
 176         }
 177 }
 178
 179 /*
 180  * tnchktc: check the last entry, see if it's tc=xxx. If so,
 181  * recursively find xxx and append that entry (minus the names)
 182  * to take the place of the tc=xxx entry. This allows termcap
 183  * entries to say "like an HP2621 but doesn't turn on the labels".
 184  * Note that this works because of the left to right scan.
 185  */
 186 int
 187 tnchktc()
 188 {
 189         char *p, *q;
 190         char tcname[16];        /* name of similar terminal */
 191         char tcbuf[BUFSIZ];
 192         char *holdtbuf = tbuf;
 193         int l;
 194
 195         p = tbuf + strlen(tbuf) - 2;    /* before the last colon */
 196         while (*--p != ':')
 197                 if (p < tbuf) {
 198                         write(STDERR_FILENO, "Bad remcap entry\n", 18);
 199                         return (0);
 200                 }
 201         p++;
 202         /* p now points to beginning of last field */
 203         if (p[0] != 't' || p[1] != 'c')
 204                 return (1);
 205         strlcpy(tcname, p + 3, sizeof tcname);
 206         q = tcname;
 207         while (*q && *q != ':')
 208                 q++;
 209         *q = 0;
 210         if (++hopcount > MAXHOP) {
 211                 write(STDERR_FILENO, "Infinite tc= loop\n", 18);
 212                 return (0);
 213         }
 214         if (getent(tcbuf, tcname, remotefile) != 1) {
 215                 return (0);
 216         }
 217         for (q = tcbuf; *q++ != ':'; )
 218                 ;
 219         l = p - holdtbuf + strlen(q);
 220         if (l > BUFSIZ) {
 221                 write(STDERR_FILENO, "Remcap entry too long\n", 23);
 222                 q[BUFSIZ - (p-holdtbuf)] = 0;
 223         }
 224         strcpy(p, q);
 225         tbuf = holdtbuf;
 226         return (1);
 227 }
 228
 229 /*
 230  * Tnamatch deals with name matching.  The first field of the termcap
 231  * entry is a sequence of names separated by |'s, so we compare
 232  * against each such name.  The normal : terminator after the last
 233  * name (before the first field) stops us.
 234  */
 235 int
 236 tnamatch(np)
 237         char *np;
 238 {
 239         char *Np, *Bp;
 240
 241         Bp = tbuf;
 242         if (*Bp == '#')
 243                 return (0);
 244         for (;;) {
 245                 for (Np = np; *Np && *Bp == *Np; Bp++, Np++)
 246                         continue;
 247                 if (*Np == 0 && (*Bp == '|' || *Bp == ':' || *Bp == 0))
 248                         return (1);
 249                 while (*Bp && *Bp != ':' && *Bp != '|')
 250                         Bp++;
 251                 if (*Bp == 0 || *Bp == ':')
 252                         return (0);
 253                 Bp++;
 254         }
 255 }
 256
 257 /*
 258  * Skip to the next field.  Notice that this is very dumb, not
 259  * knowing about \: escapes or any such.  If necessary, :'s can be put
 260  * into the termcap file in octal.
 261  */
 262 static char *
 263 tskip(bp)
 264         char *bp;
 265 {
 266         int dquote;
 267
 268         dquote = 0;
 269         while (*bp) {
 270                 switch (*bp) {
 271                 case ':':
 272                         if (!dquote)
 273                                 goto breakbreak;
 274                         else
 275                                 bp++;
 276                         break;
 277                 case '\\':
 278                         bp++;
 279                         if (isdigit(*bp)) {
 280                                 while (isdigit(*bp++))
 281                                         ;
 282                         } else
 283                                 bp++;
 284                 case '"':
 285                         dquote = (dquote ? 1 : 0);
 286                         bp++;
 287                         break;
 288                 default:
 289                         bp++;
 290                         break;
 291                 }
 292         }
 293 breakbreak:
 294         if (*bp == ':')
 295                 bp++;
 296         return (bp);
 297 }
 298
 299 /*
 300  * Return the (numeric) option id.
 301  * Numeric options look like
 302  *      li#80
 303  * i.e. the option string is separated from the numeric value by
 304  * a # character.  If the option is not found we return -1.
 305  * Note that we handle octal numbers beginning with 0.
 306  */
 307 int64_t
 308 tgetnum(id)
 309         char *id;
 310 {
 311         int64_t i;
 312         int base;
 313         char *bp = tbuf;
 314
 315         for (;;) {
 316                 bp = tskip(bp);
 317                 if (*bp == 0)
 318                         return (-1);
 319                 if (strncmp(bp, id, strlen(id)) != 0)
 320                         continue;
 321                 bp += strlen(id);
 322                 if (*bp == '@')
 323                         return (-1);
 324                 if (*bp != '#')
 325                         continue;
 326                 bp++;
 327                 base = 10;
 328                 if (*bp == '0')
 329                         base = 8;
 330                 i = 0;
 331                 while (isdigit(*bp))
 332                         i *= base, i += *bp++ - '0';
 333                 return (i);
 334         }
 335 }
 336
 337 /*
 338  * Handle a flag option.
 339  * Flag options are given "naked", i.e. followed by a : or the end
 340  * of the buffer.  Return 1 if we find the option, or 0 if it is
 341  * not given.
 342  */
 343 int
 344 tgetflag(id)
 345         char *id;
 346 {
 347         char *bp = tbuf;
 348
 349         for (;;) {
 350                 bp = tskip(bp);
 351                 if (!*bp)
 352                         return (0);
 353                 if (strncmp(bp, id, strlen(id)) == 0) {
 354                         bp += strlen(id);
 355                         if (!*bp || *bp == ':')
 356                                 return (1);
 357                         else if (*bp == '@')
 358                                 return (0);
 359                 }
 360         }
 361 }
 362
 363 /*
 364  * Get a string valued option.
 365  * These are given as
 366  *      cl=^Z
 367  * Much decoding is done on the strings, and the strings are
 368  * placed in area, which is a ref parameter which is updated.
 369  * No checking on area overflow.
 370  */
 371 char *
 372 tgetstr(id, area)
 373         char *id, **area;
 374 {
 375         char *bp = tbuf;
 376
 377         for (;;) {
 378                 bp = tskip(bp);
 379                 if (!*bp)
 380                         return (0);
 381                 if (strncmp(bp, id, strlen(id)) != 0)
 382                         continue;
 383                 bp += strlen(id);
 384                 if (*bp == '@')
 385                         return (0);
 386                 if (*bp != '=')
 387                         continue;
 388                 bp++;
 389                 return (tdecode(bp, area));
 390         }
 391 }
 392
 393 /*
 394  * Tdecode does the grung work to decode the
 395  * string capability escapes.
 396  */
 397 static char *
 398 tdecode(str, area)
 399         char *str;
 400         char **area;
 401 {
 402         char *cp;
 403         int c;
 404         char *dp;
 405         int i;
 406         char term;
 407
 408         term = ':';
 409         cp = *area;
 410 again:
 411         if (*str == '"') {
 412                 term = '"';
 413                 str++;
 414         }
 415         while ((c = *str++) && c != term) {
 416                 switch (c) {
 417
 418                 case '^':
 419                         c = *str++ & 037;
 420                         break;
 421
 422                 case '\\':
 423                         dp = "E\033^^\\\\::n\nr\rt\tb\bf\f\"\"";
 424                         c = *str++;
 425 nextc:
 426                         if (*dp++ == c) {
 427                                 c = *dp++;
 428                                 break;
 429                         }
 430                         dp++;
 431                         if (*dp)
 432                                 goto nextc;
 433                         if (isdigit(c)) {
 434                                 c -= '0', i = 2;
 435                                 do
 436                                         c <<= 3, c |= *str++ - '0';
 437                                 while (--i && isdigit(*str));
 438                         }
 439                         break;
 440                 }
 441                 *cp++ = c;
 442         }
 443         if (c == term && term != ':') {
 444                 term = ':';
 445                 goto again;
 446         }
 447         *cp++ = 0;
 448         str = *area;
 449         *area = cp;
 450         return (str);
 451 }