usr.sbin/rtadvd/advcap.c

   1 /*      $KAME: advcap.c,v 1.5 2001/02/01 09:12:08 jinmei Exp $  */
   2
   3 /*
   4  * Copyright (c) 1983 The Regents of the University of California.
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. Neither the name of the University nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  *
  31  * $FreeBSD: src/usr.sbin/rtadvd/advcap.c,v 1.1.2.2 2001/07/03 11:02:13 ume Exp $
  32  * $DragonFly: src/usr.sbin/rtadvd/advcap.c,v 1.5 2005/02/17 14:00:10 joerg Exp $
  33  */
  34
  35 /*
  36  * remcap - routines for dealing with the remote host data base
  37  *
  38  * derived from termcap
  39  */
  40 #include <sys/types.h>
  41 #include <sys/uio.h>
  42 #include <unistd.h>
  43 #include <fcntl.h>
  44 #include <ctype.h>
  45 #include <stdlib.h>
  46 #include <stdio.h>
  47 #include <syslog.h>
  48 #include <errno.h>
  49 #include <string.h>
  50 #include "pathnames.h"
  51
  52 #ifndef BUFSIZ
  53 #define BUFSIZ          1024
  54 #endif
  55 #define MAXHOP          32              /* max number of tc= indirections */
  56
  57 #define tgetent         agetent
  58 #define tnchktc         anchktc
  59 #define tnamatch        anamatch
  60 #define tgetnum         agetnum
  61 #define tgetflag        agetflag
  62 #define tgetstr         agetstr
  63
  64 #if 0
  65 #define V_TERMCAP       "REMOTE"
  66 #define V_TERM          "HOST"
  67 #endif
  68
  69 char    *RM;
  70
  71 /*
  72  * termcap - routines for dealing with the terminal capability data base
  73  *
  74  * BUG:         Should use a "last" pointer in tbuf, so that searching
  75  *              for capabilities alphabetically would not be a n**2/2
  76  *              process when large numbers of capabilities are given.
  77  * Note:        If we add a last pointer now we will screw up the
  78  *              tc capability. We really should compile termcap.
  79  *
  80  * Essentially all the work here is scanning and decoding escapes
  81  * in string capabilities.  We don't use stdio because the editor
  82  * doesn't, and because living w/o it is not hard.
  83  */
  84
  85 static  char *tbuf;
  86 static  int hopcount;   /* detect infinite loops in termcap, init 0 */
  87
  88 static  char *remotefile;
  89
  90 extern char *conffile;
  91
  92 int tgetent(char *, char *);
  93 int getent(char *, char *, char *);
  94 int tnchktc(void);
  95 int tnamatch(char *);
  96 static char *tskip(char *);
  97 long long tgetnum(char *);
  98 int tgetflag(char *);
  99 char *tgetstr(char *, char **);
 100 static char *tdecode(char *, char **);
 101
 102 /*
 103  * Get an entry for terminal name in buffer bp,
 104  * from the termcap file.  Parse is very rudimentary;
 105  * we just notice escaped newlines.
 106  */
 107 int
 108 tgetent(char *bp, char *name)
 109 {
 110         char *cp;
 111
 112         remotefile = cp = conffile ? conffile : _PATH_RTADVDCONF;
 113         return (getent(bp, name, cp));
 114 }
 115
 116 int
 117 getent(char *bp, char *name, char *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(void)
 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         strcpy(tcname, p+3);
 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(char *np)
 236 {
 237         char *Np, *Bp;
 238
 239         Bp = tbuf;
 240         if (*Bp == '#')
 241                 return (0);
 242         for (;;) {
 243                 for (Np = np; *Np && *Bp == *Np; Bp++, Np++)
 244                         continue;
 245                 if (*Np == 0 && (*Bp == '|' || *Bp == ':' || *Bp == 0))
 246                         return (1);
 247                 while (*Bp && *Bp != ':' && *Bp != '|')
 248                         Bp++;
 249                 if (*Bp == 0 || *Bp == ':')
 250                         return (0);
 251                 Bp++;
 252         }
 253 }
 254
 255 /*
 256  * Skip to the next field.  Notice that this is very dumb, not
 257  * knowing about \: escapes or any such.  If necessary, :'s can be put
 258  * into the termcap file in octal.
 259  */
 260 static char *
 261 tskip(char *bp)
 262 {
 263         int dquote;
 264
 265         dquote = 0;
 266         while (*bp) {
 267                 switch (*bp) {
 268                 case ':':
 269                         if (!dquote)
 270                                 goto breakbreak;
 271                         else
 272                                 bp++;
 273                         break;
 274                 case '\\':
 275                         bp++;
 276                         if (isdigit(*bp)) {
 277                                 while (isdigit(*bp++))
 278                                         ;
 279                         } else
 280                                 bp++;
 281                 case '"':
 282                         dquote = (dquote ? 1 : 0);
 283                         bp++;
 284                         break;
 285                 default:
 286                         bp++;
 287                         break;
 288                 }
 289         }
 290 breakbreak:
 291         if (*bp == ':')
 292                 bp++;
 293         return (bp);
 294 }
 295
 296 /*
 297  * Return the (numeric) option id.
 298  * Numeric options look like
 299  *      li#80
 300  * i.e. the option string is separated from the numeric value by
 301  * a # character.  If the option is not found we return -1.
 302  * Note that we handle octal numbers beginning with 0.
 303  */
 304 long long
 305 tgetnum(char *id)
 306 {
 307         long long i;
 308         int base;
 309         char *bp = tbuf;
 310
 311         for (;;) {
 312                 bp = tskip(bp);
 313                 if (*bp == 0)
 314                         return (-1);
 315                 if (strncmp(bp, id, strlen(id)) != 0)
 316                         continue;
 317                 bp += strlen(id);
 318                 if (*bp == '@')
 319                         return (-1);
 320                 if (*bp != '#')
 321                         continue;
 322                 bp++;
 323                 base = 10;
 324                 if (*bp == '0')
 325                         base = 8;
 326                 i = 0;
 327                 while (isdigit(*bp))
 328                         i *= base, i += *bp++ - '0';
 329                 return (i);
 330         }
 331 }
 332
 333 /*
 334  * Handle a flag option.
 335  * Flag options are given "naked", i.e. followed by a : or the end
 336  * of the buffer.  Return 1 if we find the option, or 0 if it is
 337  * not given.
 338  */
 339 int
 340 tgetflag(char *id)
 341 {
 342         char *bp = tbuf;
 343
 344         for (;;) {
 345                 bp = tskip(bp);
 346                 if (!*bp)
 347                         return (0);
 348                 if (strncmp(bp, id, strlen(id)) == 0) {
 349                         bp += strlen(id);
 350                         if (!*bp || *bp == ':')
 351                                 return (1);
 352                         else if (*bp == '@')
 353                                 return (0);
 354                 }
 355         }
 356 }
 357
 358 /*
 359  * Get a string valued option.
 360  * These are given as
 361  *      cl=^Z
 362  * Much decoding is done on the strings, and the strings are
 363  * placed in area, which is a ref parameter which is updated.
 364  * No checking on area overflow.
 365  */
 366 char *
 367 tgetstr(char *id, char **area)
 368 {
 369         char *bp = tbuf;
 370
 371         for (;;) {
 372                 bp = tskip(bp);
 373                 if (!*bp)
 374                         return (0);
 375                 if (strncmp(bp, id, strlen(id)) != 0)
 376                         continue;
 377                 bp += strlen(id);
 378                 if (*bp == '@')
 379                         return (0);
 380                 if (*bp != '=')
 381                         continue;
 382                 bp++;
 383                 return (tdecode(bp, area));
 384         }
 385 }
 386
 387 /*
 388  * Tdecode does the grunt work to decode the
 389  * string capability escapes.
 390  */
 391 static char *
 392 tdecode(char *str, char **area)
 393 {
 394         char *cp;
 395         int c;
 396         char *dp;
 397         int i;
 398         char term;
 399
 400         term = ':';
 401         cp = *area;
 402 again:
 403         if (*str == '"') {
 404                 term = '"';
 405                 str++;
 406         }
 407         while ((c = *str++) && c != term) {
 408                 switch (c) {
 409
 410                 case '^':
 411                         c = *str++ & 037;
 412                         break;
 413
 414                 case '\\':
 415                         dp = "E\033^^\\\\::n\nr\rt\tb\bf\f\"\"";
 416                         c = *str++;
 417 nextc:
 418                         if (*dp++ == c) {
 419                                 c = *dp++;
 420                                 break;
 421                         }
 422                         dp++;
 423                         if (*dp)
 424                                 goto nextc;
 425                         if (isdigit(c)) {
 426                                 c -= '0', i = 2;
 427                                 do
 428                                         c <<= 3, c |= *str++ - '0';
 429                                 while (--i && isdigit(*str));
 430                         }
 431                         break;
 432                 }
 433                 *cp++ = c;
 434         }
 435         if (c == term && term != ':') {
 436                 term = ':';
 437                 goto again;
 438         }
 439         *cp++ = 0;
 440         str = *area;
 441         *area = cp;
 442         return (str);
 443 }