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. All advertising materials mentioning features or use of this software
  16  *    must display the following acknowledgement:
  17  *      This product includes software developed by the University of
  18  *      California, Berkeley and its contributors.
  19  * 4. Neither the name of the University nor the names of its contributors
  20  *    may be used to endorse or promote products derived from this software
  21  *    without specific prior written permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  33  * SUCH DAMAGE.
  34  *
  35  * $FreeBSD: src/usr.sbin/rtadvd/advcap.c,v 1.1.2.2 2001/07/03 11:02:13 ume Exp $
  36  * $DragonFly: src/usr.sbin/rtadvd/advcap.c,v 1.5 2005/02/17 14:00:10 joerg Exp $
  37  */
  38
  39 /*
  40  * remcap - routines for dealing with the remote host data base
  41  *
  42  * derived from termcap
  43  */
  44 #include <sys/types.h>
  45 #include <sys/uio.h>
  46 #include <unistd.h>
  47 #include <fcntl.h>
  48 #include <ctype.h>
  49 #include <stdlib.h>
  50 #include <stdio.h>
  51 #include <syslog.h>
  52 #include <errno.h>
  53 #include <string.h>
  54 #include "pathnames.h"
  55
  56 #ifndef BUFSIZ
  57 #define BUFSIZ          1024
  58 #endif
  59 #define MAXHOP          32              /* max number of tc= indirections */
  60
  61 #define tgetent         agetent
  62 #define tnchktc         anchktc
  63 #define tnamatch        anamatch
  64 #define tgetnum         agetnum
  65 #define tgetflag        agetflag
  66 #define tgetstr         agetstr
  67
  68 #if 0
  69 #define V_TERMCAP       "REMOTE"
  70 #define V_TERM          "HOST"
  71 #endif
  72
  73 char    *RM;
  74
  75 /*
  76  * termcap - routines for dealing with the terminal capability data base
  77  *
  78  * BUG:         Should use a "last" pointer in tbuf, so that searching
  79  *              for capabilities alphabetically would not be a n**2/2
  80  *              process when large numbers of capabilities are given.
  81  * Note:        If we add a last pointer now we will screw up the
  82  *              tc capability. We really should compile termcap.
  83  *
  84  * Essentially all the work here is scanning and decoding escapes
  85  * in string capabilities.  We don't use stdio because the editor
  86  * doesn't, and because living w/o it is not hard.
  87  */
  88
  89 static  char *tbuf;
  90 static  int hopcount;   /* detect infinite loops in termcap, init 0 */
  91
  92 static  char *remotefile;
  93
  94 extern char *conffile;
  95
  96 int tgetent(char *, char *);
  97 int getent(char *, char *, char *);
  98 int tnchktc(void);
  99 int tnamatch(char *);
 100 static char *tskip(char *);
 101 long long tgetnum(char *);
 102 int tgetflag(char *);
 103 char *tgetstr(char *, char **);
 104 static char *tdecode(char *, char **);
 105
 106 /*
 107  * Get an entry for terminal name in buffer bp,
 108  * from the termcap file.  Parse is very rudimentary;
 109  * we just notice escaped newlines.
 110  */
 111 int
 112 tgetent(char *bp, char *name)
 113 {
 114         char *cp;
 115
 116         remotefile = cp = conffile ? conffile : _PATH_RTADVDCONF;
 117         return (getent(bp, name, cp));
 118 }
 119
 120 int
 121 getent(char *bp, char *name, char *cp)
 122 {
 123         int c;
 124         int i = 0, cnt = 0;
 125         char ibuf[BUFSIZ];
 126         int tf;
 127
 128         tbuf = bp;
 129         tf = 0;
 130         /*
 131          * TERMCAP can have one of two things in it. It can be the
 132          * name of a file to use instead of /etc/termcap. In this
 133          * case it better start with a "/". Or it can be an entry to
 134          * use so we don't have to read the file. In this case it
 135          * has to already have the newlines crunched out.
 136          */
 137         if (cp && *cp) {
 138                 tf = open(RM = cp, O_RDONLY);
 139         }
 140         if (tf < 0) {
 141                 syslog(LOG_INFO,
 142                        "<%s> open: %s", __func__, strerror(errno));
 143                 return (-2);
 144         }
 145         for (;;) {
 146                 cp = bp;
 147                 for (;;) {
 148                         if (i == cnt) {
 149                                 cnt = read(tf, ibuf, BUFSIZ);
 150                                 if (cnt <= 0) {
 151                                         close(tf);
 152                                         return (0);
 153                                 }
 154                                 i = 0;
 155                         }
 156                         c = ibuf[i++];
 157                         if (c == '\n') {
 158                                 if (cp > bp && cp[-1] == '\\') {
 159                                         cp--;
 160                                         continue;
 161                                 }
 162                                 break;
 163                         }
 164                         if (cp >= bp+BUFSIZ) {
 165                                 write(2,"Remcap entry too long\n", 23);
 166                                 break;
 167                         } else
 168                                 *cp++ = c;
 169                 }
 170                 *cp = 0;
 171
 172                 /*
 173                  * The real work for the match.
 174                  */
 175                 if (tnamatch(name)) {
 176                         close(tf);
 177                         return (tnchktc());
 178                 }
 179         }
 180 }
 181
 182 /*
 183  * tnchktc: check the last entry, see if it's tc=xxx. If so,
 184  * recursively find xxx and append that entry (minus the names)
 185  * to take the place of the tc=xxx entry. This allows termcap
 186  * entries to say "like an HP2621 but doesn't turn on the labels".
 187  * Note that this works because of the left to right scan.
 188  */
 189 int
 190 tnchktc(void)
 191 {
 192         char *p, *q;
 193         char tcname[16];        /* name of similar terminal */
 194         char tcbuf[BUFSIZ];
 195         char *holdtbuf = tbuf;
 196         int l;
 197
 198         p = tbuf + strlen(tbuf) - 2;    /* before the last colon */
 199         while (*--p != ':')
 200                 if (p<tbuf) {
 201                         write(2, "Bad remcap entry\n", 18);
 202                         return (0);
 203                 }
 204         p++;
 205         /* p now points to beginning of last field */
 206         if (p[0] != 't' || p[1] != 'c')
 207                 return (1);
 208         strcpy(tcname, p+3);
 209         q = tcname;
 210         while (*q && *q != ':')
 211                 q++;
 212         *q = 0;
 213         if (++hopcount > MAXHOP) {
 214                 write(2, "Infinite tc= loop\n", 18);
 215                 return (0);
 216         }
 217         if (getent(tcbuf, tcname, remotefile) != 1) {
 218                 return (0);
 219         }
 220         for (q = tcbuf; *q++ != ':'; )
 221                 ;
 222         l = p - holdtbuf + strlen(q);
 223         if (l > BUFSIZ) {
 224                 write(2, "Remcap entry too long\n", 23);
 225                 q[BUFSIZ - (p-holdtbuf)] = 0;
 226         }
 227         strcpy(p, q);
 228         tbuf = holdtbuf;
 229         return (1);
 230 }
 231
 232 /*
 233  * Tnamatch deals with name matching.  The first field of the termcap
 234  * entry is a sequence of names separated by |'s, so we compare
 235  * against each such name.  The normal : terminator after the last
 236  * name (before the first field) stops us.
 237  */
 238 int
 239 tnamatch(char *np)
 240 {
 241         char *Np, *Bp;
 242
 243         Bp = tbuf;
 244         if (*Bp == '#')
 245                 return (0);
 246         for (;;) {
 247                 for (Np = np; *Np && *Bp == *Np; Bp++, Np++)
 248                         continue;
 249                 if (*Np == 0 && (*Bp == '|' || *Bp == ':' || *Bp == 0))
 250                         return (1);
 251                 while (*Bp && *Bp != ':' && *Bp != '|')
 252                         Bp++;
 253                 if (*Bp == 0 || *Bp == ':')
 254                         return (0);
 255                 Bp++;
 256         }
 257 }
 258
 259 /*
 260  * Skip to the next field.  Notice that this is very dumb, not
 261  * knowing about \: escapes or any such.  If necessary, :'s can be put
 262  * into the termcap file in octal.
 263  */
 264 static char *
 265 tskip(char *bp)
 266 {
 267         int dquote;
 268
 269         dquote = 0;
 270         while (*bp) {
 271                 switch (*bp) {
 272                 case ':':
 273                         if (!dquote)
 274                                 goto breakbreak;
 275                         else
 276                                 bp++;
 277                         break;
 278                 case '\\':
 279                         bp++;
 280                         if (isdigit(*bp)) {
 281                                 while (isdigit(*bp++))
 282                                         ;
 283                         } else
 284                                 bp++;
 285                 case '"':
 286                         dquote = (dquote ? 1 : 0);
 287                         bp++;
 288                         break;
 289                 default:
 290                         bp++;
 291                         break;
 292                 }
 293         }
 294 breakbreak:
 295         if (*bp == ':')
 296                 bp++;
 297         return (bp);
 298 }
 299
 300 /*
 301  * Return the (numeric) option id.
 302  * Numeric options look like
 303  *      li#80
 304  * i.e. the option string is separated from the numeric value by
 305  * a # character.  If the option is not found we return -1.
 306  * Note that we handle octal numbers beginning with 0.
 307  */
 308 long long
 309 tgetnum(char *id)
 310 {
 311         long long 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(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(char *id, char **area)
 372 {
 373         char *bp = tbuf;
 374
 375         for (;;) {
 376                 bp = tskip(bp);
 377                 if (!*bp)
 378                         return (0);
 379                 if (strncmp(bp, id, strlen(id)) != 0)
 380                         continue;
 381                 bp += strlen(id);
 382                 if (*bp == '@')
 383                         return (0);
 384                 if (*bp != '=')
 385                         continue;
 386                 bp++;
 387                 return (tdecode(bp, area));
 388         }
 389 }
 390
 391 /*
 392  * Tdecode does the grunt work to decode the
 393  * string capability escapes.
 394  */
 395 static char *
 396 tdecode(char *str, char **area)
 397 {
 398         char *cp;
 399         int c;
 400         char *dp;
 401         int i;
 402         char term;
 403
 404         term = ':';
 405         cp = *area;
 406 again:
 407         if (*str == '"') {
 408                 term = '"';
 409                 str++;
 410         }
 411         while ((c = *str++) && c != term) {
 412                 switch (c) {
 413
 414                 case '^':
 415                         c = *str++ & 037;
 416                         break;
 417
 418                 case '\\':
 419                         dp = "E\033^^\\\\::n\nr\rt\tb\bf\f\"\"";
 420                         c = *str++;
 421 nextc:
 422                         if (*dp++ == c) {
 423                                 c = *dp++;
 424                                 break;
 425                         }
 426                         dp++;
 427                         if (*dp)
 428                                 goto nextc;
 429                         if (isdigit(c)) {
 430                                 c -= '0', i = 2;
 431                                 do
 432                                         c <<= 3, c |= *str++ - '0';
 433                                 while (--i && isdigit(*str));
 434                         }
 435                         break;
 436                 }
 437                 *cp++ = c;
 438         }
 439         if (c == term && term != ':') {
 440                 term = ':';
 441                 goto again;
 442         }
 443         *cp++ = 0;
 444         str = *area;
 445         *area = cp;
 446         return (str);
 447 }