usr.sbin/rtadvd/advcap.c

   1 /*      $FreeBSD: stable/10/usr.sbin/rtadvd/advcap.c 222824 2011-06-07 15:40:17Z hrs $  */
   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 /*
  68  * termcap - routines for dealing with the terminal capability data base
  69  *
  70  * BUG:         Should use a "last" pointer in tbuf, so that searching
  71  *              for capabilities alphabetically would not be a n**2/2
  72  *              process when large numbers of capabilities are given.
  73  * Note:        If we add a last pointer now we will screw up the
  74  *              tc capability. We really should compile termcap.
  75  *
  76  * Essentially all the work here is scanning and decoding escapes
  77  * in string capabilities.  We don't use stdio because the editor
  78  * doesn't, and because living w/o it is not hard.
  79  */
  80
  81 static  char *tbuf;
  82 static  int hopcount;   /* detect infinite loops in termcap, init 0 */
  83
  84 extern const char *conffile;
  85
  86 int tgetent(char *, char *);
  87 int getent(char *, char *, const char *);
  88 int tnchktc(void);
  89 int tnamatch(char *);
  90 static char *tskip(char *);
  91 int64_t tgetnum(char *);
  92 int tgetflag(char *);
  93 char *tgetstr(char *, char **);
  94 static char *tdecode(char *, char **);
  95
  96 /*
  97  * Get an entry for terminal name in buffer bp,
  98  * from the termcap file.  Parse is very rudimentary;
  99  * we just notice escaped newlines.
 100  */
 101 int
 102 tgetent(char *bp, char *name)
 103 {
 104         return (getent(bp, name, conffile));
 105 }
 106
 107 int
 108 getent(char *bp, char *name, const char *cfile)
 109 {
 110         int c;
 111         int i = 0, cnt = 0;
 112         char ibuf[BUFSIZ];
 113         char *cp;
 114         int tf;
 115
 116         tbuf = bp;
 117         tf = 0;
 118         /*
 119          * TERMCAP can have one of two things in it. It can be the
 120          * name of a file to use instead of /etc/termcap. In this
 121          * case it better start with a "/". Or it can be an entry to
 122          * use so we don't have to read the file. In this case it
 123          * has to already have the newlines crunched out.
 124          */
 125         if (cfile && *cfile)
 126                 tf = open(cfile, O_RDONLY);
 127
 128         if (tf < 0) {
 129                 syslog(LOG_INFO,
 130                        "<%s> open: %s", __func__, strerror(errno));
 131                 return (-2);
 132         }
 133         for (;;) {
 134                 cp = bp;
 135                 for (;;) {
 136                         if (i == cnt) {
 137                                 cnt = read(tf, ibuf, BUFSIZ);
 138                                 if (cnt <= 0) {
 139                                         close(tf);
 140                                         return (0);
 141                                 }
 142                                 i = 0;
 143                         }
 144                         c = ibuf[i++];
 145                         if (c == '\n') {
 146                                 if (cp > bp && cp[-1] == '\\') {
 147                                         cp--;
 148                                         continue;
 149                                 }
 150                                 break;
 151                         }
 152                         if (cp >= bp + BUFSIZ) {
 153                                 write(STDERR_FILENO, "Remcap entry too long\n",
 154                                       23);
 155                                 break;
 156                         } else
 157                                 *cp++ = c;
 158                 }
 159                 *cp = 0;
 160
 161                 /*
 162                  * The real work for the match.
 163                  */
 164                 if (tnamatch(name)) {
 165                         close(tf);
 166                         return (tnchktc());
 167                 }
 168         }
 169 }
 170
 171 /*
 172  * tnchktc: check the last entry, see if it's tc=xxx. If so,
 173  * recursively find xxx and append that entry (minus the names)
 174  * to take the place of the tc=xxx entry. This allows termcap
 175  * entries to say "like an HP2621 but doesn't turn on the labels".
 176  * Note that this works because of the left to right scan.
 177  */
 178 int
 179 tnchktc(void)
 180 {
 181         char *p, *q;
 182         char tcname[16];        /* name of similar terminal */
 183         char tcbuf[BUFSIZ];
 184         char *holdtbuf = tbuf;
 185         int l;
 186
 187         p = tbuf + strlen(tbuf) - 2;    /* before the last colon */
 188         while (*--p != ':')
 189                 if (p < tbuf) {
 190                         write(STDERR_FILENO, "Bad remcap entry\n", 18);
 191                         return (0);
 192                 }
 193         p++;
 194         /* p now points to beginning of last field */
 195         if (p[0] != 't' || p[1] != 'c')
 196                 return (1);
 197         strlcpy(tcname, p + 3, sizeof tcname);
 198         q = tcname;
 199         while (*q && *q != ':')
 200                 q++;
 201         *q = 0;
 202         if (++hopcount > MAXHOP) {
 203                 write(STDERR_FILENO, "Infinite tc= loop\n", 18);
 204                 return (0);
 205         }
 206         if (getent(tcbuf, tcname, conffile) != 1) {
 207                 return (0);
 208         }
 209         for (q = tcbuf; *q++ != ':'; )
 210                 ;
 211         l = p - holdtbuf + strlen(q);
 212         if (l > BUFSIZ) {
 213                 write(STDERR_FILENO, "Remcap entry too long\n", 23);
 214                 q[BUFSIZ - (p-holdtbuf)] = 0;
 215         }
 216         strcpy(p, q);
 217         tbuf = holdtbuf;
 218         return (1);
 219 }
 220
 221 /*
 222  * Tnamatch deals with name matching.  The first field of the termcap
 223  * entry is a sequence of names separated by |'s, so we compare
 224  * against each such name.  The normal : terminator after the last
 225  * name (before the first field) stops us.
 226  */
 227 int
 228 tnamatch(char *np)
 229 {
 230         char *Np, *Bp;
 231
 232         Bp = tbuf;
 233         if (*Bp == '#')
 234                 return (0);
 235         for (;;) {
 236                 for (Np = np; *Np && *Bp == *Np; Bp++, Np++)
 237                         continue;
 238                 if (*Np == 0 && (*Bp == '|' || *Bp == ':' || *Bp == 0))
 239                         return (1);
 240                 while (*Bp && *Bp != ':' && *Bp != '|')
 241                         Bp++;
 242                 if (*Bp == 0 || *Bp == ':')
 243                         return (0);
 244                 Bp++;
 245         }
 246 }
 247
 248 /*
 249  * Skip to the next field.  Notice that this is very dumb, not
 250  * knowing about \: escapes or any such.  If necessary, :'s can be put
 251  * into the termcap file in octal.
 252  */
 253 static char *
 254 tskip(char *bp)
 255 {
 256         int dquote;
 257
 258         dquote = 0;
 259         while (*bp) {
 260                 switch (*bp) {
 261                 case ':':
 262                         if (!dquote)
 263                                 goto breakbreak;
 264                         else
 265                                 bp++;
 266                         break;
 267                 case '\\':
 268                         bp++;
 269                         if (isdigit(*bp)) {
 270                                 while (isdigit(*bp++))
 271                                         ;
 272                         } else
 273                                 bp++;
 274                         /* FALLTHROUGH */
 275                 case '"':
 276                         dquote = (dquote ? 1 : 0);
 277                         bp++;
 278                         break;
 279                 default:
 280                         bp++;
 281                         break;
 282                 }
 283         }
 284 breakbreak:
 285         if (*bp == ':')
 286                 bp++;
 287         return (bp);
 288 }
 289
 290 /*
 291  * Return the (numeric) option id.
 292  * Numeric options look like
 293  *      li#80
 294  * i.e. the option string is separated from the numeric value by
 295  * a # character.  If the option is not found we return -1.
 296  * Note that we handle octal numbers beginning with 0.
 297  */
 298 int64_t
 299 tgetnum(char *id)
 300 {
 301         int64_t i;
 302         int base;
 303         char *bp = tbuf;
 304
 305         for (;;) {
 306                 bp = tskip(bp);
 307                 if (*bp == 0)
 308                         return (-1);
 309                 if (strncmp(bp, id, strlen(id)) != 0)
 310                         continue;
 311                 bp += strlen(id);
 312                 if (*bp == '@')
 313                         return (-1);
 314                 if (*bp != '#')
 315                         continue;
 316                 bp++;
 317                 base = 10;
 318                 if (*bp == '0')
 319                         base = 8;
 320                 i = 0;
 321                 while (isdigit(*bp))
 322                         i *= base, i += *bp++ - '0';
 323                 return (i);
 324         }
 325 }
 326
 327 /*
 328  * Handle a flag option.
 329  * Flag options are given "naked", i.e. followed by a : or the end
 330  * of the buffer.  Return 1 if we find the option, or 0 if it is
 331  * not given.
 332  */
 333 int
 334 tgetflag(char *id)
 335 {
 336         char *bp = tbuf;
 337
 338         for (;;) {
 339                 bp = tskip(bp);
 340                 if (!*bp)
 341                         return (0);
 342                 if (strncmp(bp, id, strlen(id)) == 0) {
 343                         bp += strlen(id);
 344                         if (!*bp || *bp == ':')
 345                                 return (1);
 346                         else if (*bp == '@')
 347                                 return (0);
 348                 }
 349         }
 350 }
 351
 352 /*
 353  * Get a string valued option.
 354  * These are given as
 355  *      cl=^Z
 356  * Much decoding is done on the strings, and the strings are
 357  * placed in area, which is a ref parameter which is updated.
 358  * No checking on area overflow.
 359  */
 360 char *
 361 tgetstr(char *id, char **area)
 362 {
 363         char *bp = tbuf;
 364
 365         for (;;) {
 366                 bp = tskip(bp);
 367                 if (!*bp)
 368                         return (0);
 369                 if (strncmp(bp, id, strlen(id)) != 0)
 370                         continue;
 371                 bp += strlen(id);
 372                 if (*bp == '@')
 373                         return (0);
 374                 if (*bp != '=')
 375                         continue;
 376                 bp++;
 377                 return (tdecode(bp, area));
 378         }
 379 }
 380
 381 /*
 382  * Tdecode does the grung work to decode the
 383  * string capability escapes.
 384  */
 385 static char *
 386 tdecode(char *str, char **area)
 387 {
 388         char *cp;
 389         int c;
 390         const char *dp;
 391         int i;
 392         char term;
 393
 394         term = ':';
 395         cp = *area;
 396 again:
 397         if (*str == '"') {
 398                 term = '"';
 399                 str++;
 400         }
 401         while ((c = *str++) && c != term) {
 402                 switch (c) {
 403
 404                 case '^':
 405                         c = *str++ & 037;
 406                         break;
 407
 408                 case '\\':
 409                         dp = "E\033^^\\\\::n\nr\rt\tb\bf\f\"\"";
 410                         c = *str++;
 411 nextc:
 412                         if (*dp++ == c) {
 413                                 c = *dp++;
 414                                 break;
 415                         }
 416                         dp++;
 417                         if (*dp)
 418                                 goto nextc;
 419                         if (isdigit(c)) {
 420                                 c -= '0', i = 2;
 421                                 do
 422                                         c <<= 3, c |= *str++ - '0';
 423                                 while (--i && isdigit(*str));
 424                         }
 425                         break;
 426                 }
 427                 *cp++ = c;
 428         }
 429         if (c == term && term != ':') {
 430                 term = ':';
 431                 goto again;
 432         }
 433         *cp++ = 0;
 434         str = *area;
 435         *area = cp;
 436         return (str);
 437 }