release/src/router/ppp/pppd/plugins/pppoe/utils.c

   1
   2 /*
   3  * utils.c - various utility functions used in pppoed.
   4  *
   5  * mostly stolen from ppp-2.3.10 by Marc Boucher <marc@mbsi.ca>
   6  *
   7  * Feb 18/2000 Made fully re-entrant (JHS)
   8  *
   9  * Copyright (c) 1999 The Australian National University.
  10  * All rights reserved.
  11  *
  12  * Redistribution and use in source and binary forms are permitted
  13  * provided that the above copyright poe_notice and this paragraph are
  14  * duplicated in all such forms and that any documentation,
  15  * advertising materials, and other materials related to such
  16  * distribution and use acknowledge that the software was developed
  17  * by the Australian National University.  The name of the University
  18  * may not be used to endorse or promote products derived from this
  19  * software without specific prior written permission.
  20  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
  21  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
  22  * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  23  */
  24
  25 #include <stdio.h>              /* stdio               */
  26 #include <stdlib.h>             /* strtoul(), realloc() */
  27 #include <string.h>             /* memcpy()             */
  28 #include <unistd.h>             /* STDIN_FILENO,exec    */
  29 #include <errno.h>              /* errno                */
  30
  31 #include <sys/time.h>
  32
  33 #include <net/ethernet.h>
  34 #include <netinet/in.h>
  35
  36 #include <stdarg.h>
  37 #include <ctype.h>
  38 #include <syslog.h>
  39 #include <limits.h>
  40 #include <paths.h>
  41
  42 #include "pppoe.h"
  43
  44 static char pidfilename[PATH_MAX];      /* name of pid file */
  45
  46 /*
  47 static int detached = 0;
  48    log_to_fd = -1;
  49  */
  50
  51 static void vslp_printer (void *, char *,...);
  52 static void format_packet (struct pppoe_packet *, int, void (*)(void *, char *,...), void *);
  53 static void format_tag (struct pppoe_tag *, void (*)(void *, char *,...), void *);
  54 struct buffer_poe_info {
  55   char *ptr;
  56   int len;
  57 };
  58
  59 void poe_die (int status);
  60
  61
  62 /*
  63  * vpoe_slprintf - like vsprintf, except we
  64  * also specify the length of the output buffer, and we handle
  65  * %r (recursive format), %m (poe_error message), %v (visible string),
  66  * %q (quoted string), %t (current time) and %E (Ether address) formats.
  67  * Doesn't do floating-point formats.
  68  * Returns the number of chars put into buf.
  69  */
  70 #define OUTCHAR(c)      (buflen > 0? (--buflen, *buf++ = (c)): 0)
  71
  72 int
  73 vpoe_slprintf (char *buf, int buflen, char *fmt, va_list args)
  74 {
  75   int c, i, n;
  76   int width, prec, fillch;
  77   int base, len, neg, quoted;
  78   unsigned long val = 0;
  79   char *str, *f, *buf0;
  80   unsigned char *p;
  81   char num[32];
  82   time_t t;
  83   static char hexchars[] = "0123456789abcdef";
  84   struct buffer_poe_info bufpoe_info;
  85
  86   buf0 = buf;
  87   --buflen;
  88   while (buflen > 0) {
  89     for (f = fmt; *f != '%' && *f != 0; ++f);
  90     if (f > fmt) {
  91       len = f - fmt;
  92       if (len > buflen)
  93         len = buflen;
  94       memcpy (buf, fmt, len);
  95       buf += len;
  96       buflen -= len;
  97       fmt = f;
  98     }
  99     if (*fmt == 0)
 100       break;
 101     c = *++fmt;
 102     width = 0;
 103     prec = -1;
 104     fillch = ' ';
 105     if (c == '0') {
 106       fillch = '0';
 107       c = *++fmt;
 108     }
 109     if (c == '*') {
 110       width = va_arg (args, int);
 111       c = *++fmt;
 112     }
 113     else {
 114       while (isdigit (c)) {
 115         width = width * 10 + c - '0';
 116         c = *++fmt;
 117       }
 118     }
 119     if (c == '.') {
 120       c = *++fmt;
 121       if (c == '*') {
 122         prec = va_arg (args, int);
 123         c = *++fmt;
 124       }
 125       else {
 126         prec = 0;
 127         while (isdigit (c)) {
 128           prec = prec * 10 + c - '0';
 129           c = *++fmt;
 130         }
 131       }
 132     }
 133     str = 0;
 134     base = 0;
 135     neg = 0;
 136     ++fmt;
 137     switch (c) {
 138     case 'd':
 139       i = va_arg (args, int);
 140       if (i < 0) {
 141         neg = 1;
 142         val = -i;
 143       }
 144       else
 145         val = i;
 146       base = 10;
 147       break;
 148     case 'o':
 149       val = va_arg (args, unsigned int);
 150       base = 8;
 151       break;
 152     case 'x':
 153     case 'X':
 154       val = va_arg (args, unsigned int);
 155       base = 16;
 156       break;
 157     case 'p':
 158       val = (unsigned long) va_arg (args, void *);
 159       base = 16;
 160       neg = 2;
 161       break;
 162     case 's':
 163       str = va_arg (args, char *);
 164       break;
 165     case 'c':
 166       num[0] = va_arg (args, int);
 167       num[1] = 0;
 168       str = num;
 169       break;
 170     case 'm':
 171       str = strerror (errno);
 172       break;
 173     case 'E':
 174       p = va_arg (args, unsigned char *);
 175       for (n = ETH_ALEN; n > 0; --n) {
 176         c = *p++;
 177         OUTCHAR (hexchars[(c >> 4) & 0xf]);
 178         OUTCHAR (hexchars[c & 0xf]);
 179         if (n > 1)
 180           OUTCHAR (':');
 181       }
 182       continue;
 183     case 'r':
 184       f = va_arg (args, char *);
 185 #ifndef __powerpc__
 186       n = vpoe_slprintf (buf, buflen + 1, f, va_arg (args, va_list));
 187 #else
 188       /* On the powerpc, a va_list is an array of 1 structure */
 189       n = vpoe_slprintf (buf, buflen + 1, f, va_arg (args, void *));
 190 #endif
 191       buf += n;
 192       buflen -= n;
 193       continue;
 194     case 't':
 195       time (&t);
 196       str = ctime (&t);
 197       str += 4;                 /* chop off the day name */
 198       str[15] = 0;              /* chop off year and newline */
 199       break;
 200     case 'v':                   /* "visible" string */
 201     case 'q':                   /* quoted string */
 202       quoted = c == 'q';
 203       p = va_arg (args, unsigned char *);
 204       if (fillch == '0' && prec >= 0) {
 205         n = prec;
 206       }
 207       else {
 208         n = strlen ((char *) p);
 209         if (prec >= 0 && n > prec)
 210           n = prec;
 211       }
 212       while (n > 0 && buflen > 0) {
 213         c = *p++;
 214         --n;
 215         if (!quoted && c >= 0x80) {
 216           OUTCHAR ('M');
 217           OUTCHAR ('-');
 218           c -= 0x80;
 219         }
 220         if (quoted && (c == '"' || c == '\\'))
 221           OUTCHAR ('\\');
 222         if (c < 0x20 || (0x7f <= c && c < 0xa0)) {
 223           if (quoted) {
 224             OUTCHAR ('\\');
 225             switch (c) {
 226             case '\t':
 227               OUTCHAR ('t');
 228               break;
 229             case '\n':
 230               OUTCHAR ('n');
 231               break;
 232             case '\b':
 233               OUTCHAR ('b');
 234               break;
 235             case '\f':
 236               OUTCHAR ('f');
 237               break;
 238             default:
 239               OUTCHAR ('x');
 240               OUTCHAR (hexchars[c >> 4]);
 241               OUTCHAR (hexchars[c & 0xf]);
 242             }
 243           }
 244           else {
 245             if (c == '\t')
 246               OUTCHAR (c);
 247             else {
 248               OUTCHAR ('^');
 249               OUTCHAR (c ^ 0x40);
 250             }
 251           }
 252         }
 253         else
 254           OUTCHAR (c);
 255       }
 256       continue;
 257     case 'P':                   /* print PPPoE packet */
 258       bufpoe_info.ptr = buf;
 259       bufpoe_info.len = buflen + 1;
 260       p = va_arg (args, unsigned char *);
 261       n = va_arg (args, int);
 262       format_packet ((struct pppoe_packet *) p, n, vslp_printer, &bufpoe_info);
 263       buf = bufpoe_info.ptr;
 264       buflen = bufpoe_info.len - 1;
 265       continue;
 266     case 'T':                   /* print PPPoE tag */
 267       bufpoe_info.ptr = buf;
 268       bufpoe_info.len = buflen + 1;
 269       p = va_arg (args, unsigned char *);
 270       format_tag ((struct pppoe_tag *) p, vslp_printer, &bufpoe_info);
 271       buf = bufpoe_info.ptr;
 272       buflen = bufpoe_info.len - 1;
 273       continue;
 274     case 'B':
 275       p = va_arg (args, unsigned char *);
 276       for (n = prec; n > 0; --n) {
 277         c = *p++;
 278         if (fillch == ' ')
 279           OUTCHAR (' ');
 280         OUTCHAR (hexchars[(c >> 4) & 0xf]);
 281         OUTCHAR (hexchars[c & 0xf]);
 282       }
 283       continue;
 284     default:
 285       *buf++ = '%';
 286       if (c != '%')
 287         --fmt;                  /* so %z outputs %z etc. */
 288       --buflen;
 289       continue;
 290     }
 291     if (base != 0) {
 292       str = num + sizeof (num);
 293       *--str = 0;
 294       while (str > num + neg) {
 295         *--str = hexchars[val % base];
 296         val = val / base;
 297         if (--prec <= 0 && val == 0)
 298           break;
 299       }
 300       switch (neg) {
 301       case 1:
 302         *--str = '-';
 303         break;
 304       case 2:
 305         *--str = 'x';
 306         *--str = '0';
 307         break;
 308       }
 309       len = num + sizeof (num) - 1 - str;
 310     }
 311     else {
 312       len = strlen (str);
 313       if (prec >= 0 && len > prec)
 314         len = prec;
 315     }
 316     if (width > 0) {
 317       if (width > buflen)
 318         width = buflen;
 319       if ((n = width - len) > 0) {
 320         buflen -= n;
 321         for (; n > 0; --n)
 322           *buf++ = fillch;
 323       }
 324     }
 325     if (len > buflen)
 326       len = buflen;
 327     memcpy (buf, str, len);
 328     buf += len;
 329     buflen -= len;
 330   }
 331   *buf = 0;
 332   return buf - buf0;
 333 }
 334
 335 /*
 336  * vslp_printer - used in processing a %P format
 337  */
 338 static void
 339 vslp_printer (void *arg, char *fmt,...)
 340 {
 341   int n;
 342   va_list pvar;
 343   struct buffer_poe_info *bi;
 344
 345   va_start (pvar, fmt);
 346
 347   bi = (struct buffer_poe_info *) arg;
 348   n = vpoe_slprintf (bi->ptr, bi->len, fmt, pvar);
 349   va_end (pvar);
 350
 351   bi->ptr += n;
 352   bi->len -= n;
 353 }
 354
 355 /*
 356  * format_packet - make a readable representation of a packet,
 357  * calling `printer(arg, format, ...)' to output it.
 358  */
 359 static void
 360 format_packet (struct pppoe_packet *p,
 361                int len,
 362                void (*printer) (void *, char *,...),
 363                void *arg)
 364 {
 365   struct pppoe_tag *t;
 366
 367   printer (arg, "Ether addr: %E\n", p->addr.sll_addr);
 368
 369   switch ((unsigned) ntohs (p->addr.sll_protocol)) {
 370   case ETH_P_PPPOE_DISC:
 371     printer (arg, " (PPPOE Discovery)\n");
 372     break;
 373   case ETH_P_PPPOE_SESS:
 374     printer (arg, " (PPPOE Session)\n");
 375     break;
 376   }
 377
 378   printer (arg, " PPPoE hdr: ver=0x%01x type=0x%01x code=0x%02x "
 379            "sid=0x%04x length=0x%04x ", (unsigned) p->hdr->ver,
 380            (unsigned) p->hdr->type, (unsigned) p->hdr->code, (unsigned) p->hdr->sid,
 381            (unsigned) ntohs (p->hdr->length));
 382
 383   switch (p->hdr->code) {
 384   case PADI_CODE:
 385     printer (arg, "(PADI)\n");
 386     break;
 387   case PADO_CODE:
 388     printer (arg, "(PADO)\n");
 389     break;
 390   case PADR_CODE:
 391     printer (arg, "(PADR)\n");
 392     break;
 393   case PADS_CODE:
 394     printer (arg, "(PADS)\n");
 395     break;
 396   case PADT_CODE:
 397     printer (arg, "(PADT)\n");
 398     break;
 399   default:
 400     printer (arg, "(Unknown)\n");
 401   }
 402
 403
 404   for(t = (struct pppoe_tag *) (&p->hdr->tag);
 405       (t < (struct pppoe_tag *) ((char *) (&p->hdr->tag) + ntohs (p->hdr->length))) &&
 406           ntohs (t->tag_type) != PTT_EOL;
 407       t = (struct pppoe_tag *) ((char *) (t + 1) + ntohs (t->tag_len))) {
 408       format_tag (t, printer, arg);
 409   }
 410 }
 411
 412 /*
 413  * format_tag - make a readable representation of a tag,
 414  * calling `printer(arg, format, ...)' to output it.
 415  */
 416 static void
 417 format_tag (struct pppoe_tag *t,
 418                void (*printer) (void *, char *,...),
 419                void *arg)
 420 {
 421     printer (arg, " PPPoE tag: type=%04x length=%04x ",
 422              ntohs (t->tag_type), ntohs (t->tag_len));
 423     switch ( t->tag_type ) {
 424     case PTT_EOL:
 425       printer (arg, "(End of list)");
 426       break;
 427     case PTT_SRV_NAME:
 428       printer (arg, "(Service name)");
 429       break;
 430     case PTT_AC_NAME:
 431       printer (arg, "(AC Name)");
 432       break;
 433     case PTT_HOST_UNIQ:
 434       printer (arg, "(Host Uniq)");
 435       break;
 436     case PTT_AC_COOKIE:
 437       printer (arg, "(AC Cookie)");
 438       break;
 439     case PTT_VENDOR:
 440       printer (arg, "(Vendor Specific)");
 441       break;
 442     case PTT_RELAY_SID:
 443       printer (arg, "(Relay Session ID)");
 444       break;
 445     case PTT_SRV_ERR:
 446       printer (arg, "(Service Name Error)");
 447       break;
 448     case PTT_SYS_ERR:
 449       printer (arg, "(AC System Error)");
 450       break;
 451     case PTT_GEN_ERR:
 452       printer (arg, "(Generic Error)");
 453       break;
 454     default:
 455       printer (arg, "(Unknown)");
 456     }
 457     if (ntohs (t->tag_len) > 0)
 458       switch ( t->tag_type ) {
 459       case PTT_SRV_NAME:
 460       case PTT_AC_NAME:
 461       case PTT_SRV_ERR:
 462       case PTT_SYS_ERR:
 463       case PTT_GEN_ERR: /* ascii data */
 464         {
 465           char *buf;
 466           buf = malloc (ntohs (t->tag_len) + 1);
 467           memset (buf, 0, ntohs (t->tag_len) + 1);
 468           strncpy (buf, (char *) (t + 1), ntohs (t->tag_len));
 469 //        buf[ntohs (t->tag_len)] = '\0';
 470           printer (arg, " data (UTF-8): %s", buf);
 471           free (buf);
 472           break;
 473         }
 474
 475       case PTT_HOST_UNIQ:
 476       case PTT_AC_COOKIE:
 477       case PTT_RELAY_SID:
 478         printer (arg, " data (bin): %.*B", ntohs (t->tag_len), (char *) (t + 1));
 479         break;
 480
 481       default:
 482         printer (arg, " unrecognized data");
 483       }
 484 }
 485
 486 /*
 487  * poe_logit - does the hard work for poe_fatal et al.
 488  */
 489 static void
 490 poe_logit (struct session *ses,int level, char *fmt, va_list args)
 491 {
 492   int n;
 493   char buf[256];
 494
 495   n = vpoe_slprintf (buf, sizeof (buf), fmt, args);
 496   syslog (level, "%s", buf);
 497   if (log_to_fd >= 0 && (level != LOG_DEBUG || ses->opt_debug)) {
 498     if (buf[n - 1] != '\n')
 499       buf[n++] = '\n';
 500     if (write (log_to_fd, buf, n) != n)
 501       log_to_fd = -1;
 502   }
 503 }
 504
 505 /*
 506  * poe_fatal - log an poe_error message and poe_die horribly.
 507  */
 508 void
 509 poe_fatal (struct session *ses, char *fmt,...)
 510 {
 511   va_list pvar;
 512
 513   va_start (pvar, fmt);
 514
 515   poe_logit (ses,LOG_ERR, fmt, pvar);
 516   va_end (pvar);
 517
 518   poe_die(1);                   /* as promised */
 519 }
 520
 521 /*
 522  * poe_error - log an poe_error message.
 523  */
 524 void
 525 poe_error (struct session *ses,char *fmt,...)
 526 {
 527   va_list pvar;
 528
 529   va_start (pvar, fmt);
 530
 531   poe_logit (ses,LOG_ERR, fmt, pvar);
 532   va_end (pvar);
 533 }
 534
 535 /*
 536  * poe_warn - log a poe_warning message.
 537  */
 538 void
 539 poe_warn (struct session *ses,char *fmt,...)
 540 {
 541   va_list pvar;
 542
 543   va_start (pvar, fmt);
 544
 545   poe_logit (ses,LOG_WARNING, fmt, pvar);
 546   va_end (pvar);
 547 }
 548
 549 /*
 550  * poe_info - log an poe_informational message.
 551  */
 552 void
 553 poe_info (struct session *ses,char *fmt,...)
 554 {
 555   va_list pvar;
 556
 557   va_start (pvar, fmt);
 558
 559   poe_logit (ses,LOG_INFO, fmt, pvar);
 560   va_end (pvar);
 561 }
 562
 563 /*
 564  * poe_dbglog - log a debug message.
 565  */
 566 void
 567 poe_dbglog (struct session *ses ,char *fmt,...)
 568 {
 569   va_list pvar;
 570
 571   va_start (pvar, fmt);
 572
 573   poe_logit (ses,LOG_DEBUG, fmt, pvar);
 574   va_end (pvar);
 575 }
 576
 577 /*
 578  * Create a file containing our process ID.
 579  */
 580 void
 581 poe_create_pidfile (struct session *ses)
 582 {
 583   FILE *pidfile;
 584
 585   sprintf (pidfilename, "%s%s.pid", _PATH_VARRUN, "pppoed");
 586   if ((pidfile = fopen (pidfilename, "w")) != NULL) {
 587     fprintf (pidfile, "%d\n", getpid ());
 588     (void) fclose (pidfile);
 589   }
 590   else {
 591     poe_error (ses,"Failed to create pid file %s: %m", pidfilename);
 592     pidfilename[0] = 0;
 593   }
 594 }
 595
 596 /*
 597  * detach - detach us from the controlling terminal.
 598  */
 599 void
 600 poe_detach (struct session *ses)
 601 {
 602   if (ses->detached)
 603     return;
 604
 605   if ((daemon (0, 0)) < 0) {
 606     poe_error (ses,"Couldn't detach (daemon failed: %m)");
 607   }
 608   ses->detached = 1;
 609   ses->log_to_fd = -1;
 610   /* update pid files if they have been written already */
 611   if (pidfilename[0])
 612     poe_create_pidfile (ses);
 613 }
 614
 615 /*
 616  * cleanup - restore anything which needs to be restored before we exit
 617  */
 618 /* ARGSUSED */
 619 static void
 620 cleanup ()
 621 {
 622   if (pidfilename[0] != 0 && unlink (pidfilename) < 0 && errno != ENOENT)
 623     syslog (LOG_INFO,"unable to delete pid file ");
 624   pidfilename[0] = 0;
 625 }
 626
 627 /*
 628  * poe_die - clean up state and exit with the specified status.
 629  */
 630 void
 631 poe_die (int status)
 632 {
 633   cleanup ();
 634   syslog (LOG_INFO, "Exit.");
 635   exit (status);
 636 }