pppd/pppd.h

   1 /*
   2  * pppd.h - PPP daemon global declarations.
   3  *
   4  * Copyright (c) 1989 Carnegie Mellon University.
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms are permitted
   8  * provided that the above copyright notice and this paragraph are
   9  * duplicated in all such forms and that any documentation,
  10  * advertising materials, and other materials related to such
  11  * distribution and use acknowledge that the software was developed
  12  * by Carnegie Mellon University.  The name of the
  13  * University may not be used to endorse or promote products derived
  14  * from this software without specific prior written permission.
  15  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
  16  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
  17  * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  18  *
  19  * $Id: pppd.h,v 1.24 1999/01/20 00:01:00 paulus Exp $
  20  */
  21
  22 /*
  23  * TODO:
  24  */
  25
  26 #ifndef __PPPD_H__
  27 #define __PPPD_H__
  28
  29 #include <stdio.h>              /* for FILE */
  30 #include <sys/param.h>          /* for MAXPATHLEN and BSD4_4, if defined */
  31 #include <sys/types.h>          /* for u_int32_t, if defined */
  32 #include <sys/time.h>           /* for struct timeval */
  33 #include <net/ppp_defs.h>
  34
  35 #if __STDC__
  36 #include <stdarg.h>
  37 #define __V(x)  x
  38 #else
  39 #include <varargs.h>
  40 #define __V(x)  (va_alist) va_dcl
  41 #define const
  42 #endif
  43
  44 /*
  45  * Limits.
  46  */
  47
  48 #define NUM_PPP         1       /* One PPP interface supported (per process) */
  49 #define MAXWORDLEN      1024    /* max length of word in file (incl null) */
  50 #define MAXARGS         1       /* max # args to a command */
  51 #define MAXNAMELEN      256     /* max length of hostname or name for auth */
  52 #define MAXSECRETLEN    256     /* max length of password or secret */
  53
  54 /*
  55  * Option descriptor structure.
  56  */
  57
  58 typedef unsigned char   bool;
  59
  60 enum opt_type {
  61         o_special_noarg = 0,
  62         o_special = 1,
  63         o_bool,
  64         o_int,
  65         o_uint32,
  66         o_string,
  67 };
  68
  69 typedef struct {
  70         char    *name;          /* name of the option */
  71         enum opt_type type;
  72         void    *addr;
  73         char    *description;
  74         int     flags;
  75         void    *addr2;
  76         int     upper_limit;
  77         int     lower_limit;
  78 } option_t;
  79
  80 /* Values for flags */
  81 #define OPT_VALUE       0xff    /* mask for presupplied value */
  82 #define OPT_HEX         0x100   /* int option is in hex */
  83 #define OPT_NOARG       0x200   /* option doesn't take argument */
  84 #define OPT_OR          0x400   /* OR in argument to value */
  85 #define OPT_INC         0x800   /* increment value */
  86 #define OPT_PRIV        0x1000  /* privileged option */
  87 #define OPT_STATIC      0x2000  /* string option goes into static array */
  88 #define OPT_LLIMIT      0x4000  /* check value against lower limit */
  89 #define OPT_ULIMIT      0x8000  /* check value against upper limit */
  90 #define OPT_LIMITS      (OPT_LLIMIT|OPT_ULIMIT)
  91 #define OPT_ZEROOK      0x10000 /* 0 value is OK even if not within limits */
  92 #define OPT_NOINCR      0x20000 /* value mustn't be increased */
  93 #define OPT_ZEROINF     0x40000 /* with OPT_NOINCR, 0 == infinity */
  94 #define OPT_A2INFO      0x100000 /* addr2 -> option_info to update */
  95 #define OPT_A2COPY      0x200000 /* addr2 -> second location to rcv value */
  96 #define OPT_ENABLE      0x400000 /* use *addr2 as enable for option */
  97
  98 #define OPT_VAL(x)      ((x) & OPT_VALUE)
  99
 100 /*
 101  * Global variables.
 102  */
 103
 104 extern int      hungup;         /* Physical layer has disconnected */
 105 extern int      ifunit;         /* Interface unit number */
 106 extern char     ifname[];       /* Interface name */
 107 extern int      ttyfd;          /* Serial device file descriptor */
 108 extern char     hostname[];     /* Our hostname */
 109 extern u_char   outpacket_buf[]; /* Buffer for outgoing packets */
 110 extern int      phase;          /* Current state of link - see values below */
 111 extern int      baud_rate;      /* Current link speed in bits/sec */
 112 extern char     *progname;      /* Name of this program */
 113 extern int      redirect_stderr;/* Connector's stderr should go to file */
 114 extern char     peer_authname[];/* Authenticated name of peer */
 115 extern int      privileged;     /* We were run by real-uid root */
 116 extern int      need_holdoff;   /* Need holdoff period after link terminates */
 117 extern char     **script_env;   /* Environment variables for scripts */
 118 extern int      detached;       /* Have detached from controlling tty */
 119
 120 /*
 121  * Variables set by command-line options.
 122  */
 123
 124 extern int      debug;          /* Debug flag */
 125 extern int      kdebugflag;     /* Tell kernel to print debug messages */
 126 extern int      default_device; /* Using /dev/tty or equivalent */
 127 extern char     devnam[];       /* Device name */
 128 extern int      crtscts;        /* Use hardware flow control */
 129 extern bool     modem;          /* Use modem control lines */
 130 extern int      inspeed;        /* Input/Output speed requested */
 131 extern u_int32_t netmask;       /* IP netmask to set on interface */
 132 extern bool     lockflag;       /* Create lock file to lock the serial dev */
 133 extern bool     nodetach;       /* Don't detach from controlling tty */
 134 extern bool     updetach;       /* Detach from controlling tty when link up */
 135 extern char     *connector;     /* Script to establish physical link */
 136 extern char     *disconnector;  /* Script to disestablish physical link */
 137 extern char     *welcomer;      /* Script to welcome client after connection */
 138 extern int      maxconnect;     /* Maximum connect time (seconds) */
 139 extern char     user[];         /* Our name for authenticating ourselves */
 140 extern char     passwd[];       /* Password for PAP */
 141 extern bool     auth_required;  /* Peer is required to authenticate */
 142 extern bool     persist;        /* Reopen link after it goes down */
 143 extern bool     uselogin;       /* Use /etc/passwd for checking PAP */
 144 extern char     our_name[];     /* Our name for authentication purposes */
 145 extern char     remote_name[];  /* Peer's name for authentication */
 146 extern int      explicit_remote;/* remote_name specified with remotename opt */
 147 extern bool     demand;         /* Do dial-on-demand */
 148 extern char     *ipparam;       /* Extra parameter for ip up/down scripts */
 149 extern bool     cryptpap;       /* Others' PAP passwords are encrypted */
 150 extern int      idle_time_limit;/* Shut down link if idle for this long */
 151 extern int      holdoff;        /* Dead time before restarting */
 152 #ifdef PPP_FILTER
 153 extern struct   bpf_program pass_filter;   /* Filter for pkts to pass */
 154 extern struct   bpf_program active_filter; /* Filter for link-active pkts */
 155 #endif
 156
 157 char *current_option;           /* the name of the option being parsed */
 158 int  privileged_option;         /* set iff the current option came from root */
 159 char *option_source;            /* string saying where the option came from */
 160
 161 #ifdef MSLANMAN
 162 extern bool     ms_lanman;      /* Use LanMan password instead of NT */
 163                                 /* Has meaning only with MS-CHAP challenges */
 164 #endif
 165
 166 /*
 167  * Values for phase.
 168  */
 169 #define PHASE_DEAD              0
 170 #define PHASE_INITIALIZE        1
 171 #define PHASE_DORMANT           2
 172 #define PHASE_ESTABLISH         3
 173 #define PHASE_AUTHENTICATE      4
 174 #define PHASE_CALLBACK          5
 175 #define PHASE_NETWORK           6
 176 #define PHASE_TERMINATE         7
 177 #define PHASE_HOLDOFF           8
 178
 179 /*
 180  * The following struct gives the addresses of procedures to call
 181  * for a particular protocol.
 182  */
 183 struct protent {
 184     u_short protocol;           /* PPP protocol number */
 185     /* Initialization procedure */
 186     void (*init) __P((int unit));
 187     /* Process a received packet */
 188     void (*input) __P((int unit, u_char *pkt, int len));
 189     /* Process a received protocol-reject */
 190     void (*protrej) __P((int unit));
 191     /* Lower layer has come up */
 192     void (*lowerup) __P((int unit));
 193     /* Lower layer has gone down */
 194     void (*lowerdown) __P((int unit));
 195     /* Open the protocol */
 196     void (*open) __P((int unit));
 197     /* Close the protocol */
 198     void (*close) __P((int unit, char *reason));
 199     /* Print a packet in readable form */
 200     int  (*printpkt) __P((u_char *pkt, int len,
 201                           void (*printer) __P((void *, char *, ...)),
 202                           void *arg));
 203     /* Process a received data packet */
 204     void (*datainput) __P((int unit, u_char *pkt, int len));
 205     bool enabled_flag;          /* 0 iff protocol is disabled */
 206     char *name;                 /* Text name of protocol */
 207     option_t *options;          /* List of command-line options */
 208     /* Check requested options, assign defaults */
 209     void (*check_options) __P((void));
 210     /* Configure interface for demand-dial */
 211     int  (*demand_conf) __P((int unit));
 212     /* Say whether to bring up link for this pkt */
 213     int  (*active_pkt) __P((u_char *pkt, int len));
 214 };
 215
 216 /* Table of pointers to supported protocols */
 217 extern struct protent *protocols[];
 218
 219 /*
 220  * Prototypes.
 221  */
 222
 223 /* Procedures exported from main.c. */
 224 void detach __P((void));        /* Detach from controlling tty */
 225 void die __P((int));            /* Cleanup and exit */
 226 void quit __P((void));          /* like die(1) */
 227 void novm __P((char *));        /* Say we ran out of memory, and die */
 228 void timeout __P((void (*func)(void *), void *arg, int t));
 229                                 /* Call func(arg) after t seconds */
 230 void untimeout __P((void (*func)(void *), void *arg));
 231                                 /* Cancel call to func(arg) */
 232 pid_t run_program __P((char *prog, char **args, int must_exist,
 233                        void (*done)(void *), void *arg));
 234                                 /* Run program prog with args in child */
 235 void demuxprotrej __P((int, int));
 236                                 /* Demultiplex a Protocol-Reject */
 237 void format_packet __P((u_char *, int, void (*) (void *, char *, ...),
 238                 void *));       /* Format a packet in human-readable form */
 239 void log_packet __P((u_char *, int, char *, int));
 240                                 /* Format a packet and log it with syslog */
 241 void print_string __P((char *, int,  void (*) (void *, char *, ...),
 242                 void *));       /* Format a string for output */
 243 int fmtmsg __P((char *, int, char *, ...));             /* sprintf++ */
 244 int vfmtmsg __P((char *, int, char *, va_list));        /* vsprintf++ */
 245 void script_setenv __P((char *, char *));       /* set script env var */
 246 void script_unsetenv __P((char *));             /* unset script env var */
 247
 248 /* Procedures exported from auth.c */
 249 void link_required __P((int));    /* we are starting to use the link */
 250 void link_terminated __P((int));  /* we are finished with the link */
 251 void link_down __P((int));        /* the LCP layer has left the Opened state */
 252 void link_established __P((int)); /* the link is up; authenticate now */
 253 void np_up __P((int, int));       /* a network protocol has come up */
 254 void np_down __P((int, int));     /* a network protocol has gone down */
 255 void np_finished __P((int, int)); /* a network protocol no longer needs link */
 256 void auth_peer_fail __P((int, int));
 257                                 /* peer failed to authenticate itself */
 258 void auth_peer_success __P((int, int, char *, int));
 259                                 /* peer successfully authenticated itself */
 260 void auth_withpeer_fail __P((int, int));
 261                                 /* we failed to authenticate ourselves */
 262 void auth_withpeer_success __P((int, int));
 263                                 /* we successfully authenticated ourselves */
 264 void auth_check_options __P((void));
 265                                 /* check authentication options supplied */
 266 void auth_reset __P((int));     /* check what secrets we have */
 267 int  check_passwd __P((int, char *, int, char *, int, char **, int *));
 268                                 /* Check peer-supplied username/password */
 269 int  get_secret __P((int, char *, char *, char *, int *, int));
 270                                 /* get "secret" for chap */
 271 int  auth_ip_addr __P((int, u_int32_t));
 272                                 /* check if IP address is authorized */
 273 int  bad_ip_adrs __P((u_int32_t));
 274                                 /* check if IP address is unreasonable */
 275 void check_access __P((FILE *, char *));
 276                                 /* check permissions on secrets file */
 277
 278 /* Procedures exported from demand.c */
 279 void demand_conf __P((void));   /* config interface(s) for demand-dial */
 280 void demand_block __P((void));  /* set all NPs to queue up packets */
 281 void demand_unblock __P((void)); /* set all NPs to pass packets */
 282 void demand_discard __P((void)); /* set all NPs to discard packets */
 283 void demand_rexmit __P((int));  /* retransmit saved frames for an NP */
 284 int  loop_chars __P((unsigned char *, int)); /* process chars from loopback */
 285 int  loop_frame __P((unsigned char *, int)); /* process frame from loopback */
 286
 287 /* Procedures exported from sys-*.c */
 288 void sys_init __P((void));      /* Do system-dependent initialization */
 289 void sys_cleanup __P((void));   /* Restore system state before exiting */
 290 int  sys_check_options __P((void)); /* Check options specified */
 291 void sys_close __P((void));     /* Clean up in a child before execing */
 292 int  ppp_available __P((void)); /* Test whether ppp kernel support exists */
 293 void open_ppp_loopback __P((void)); /* Open loopback for demand-dialling */
 294 void establish_ppp __P((int));  /* Turn serial port into a ppp interface */
 295 void restore_loop __P((void));  /* Transfer ppp unit back to loopback */
 296 void disestablish_ppp __P((int)); /* Restore port to normal operation */
 297 void clean_check __P((void));   /* Check if line was 8-bit clean */
 298 void set_up_tty __P((int, int)); /* Set up port's speed, parameters, etc. */
 299 void restore_tty __P((int));    /* Restore port's original parameters */
 300 void setdtr __P((int, int));    /* Raise or lower port's DTR line */
 301 void output __P((int, u_char *, int)); /* Output a PPP packet */
 302 void wait_input __P((struct timeval *));
 303                                 /* Wait for input, with timeout */
 304 void wait_loop_output __P((struct timeval *));
 305                                 /* Wait for pkt from loopback, with timeout */
 306 void wait_time __P((struct timeval *)); /* Wait for given length of time */
 307 int  read_packet __P((u_char *)); /* Read PPP packet */
 308 int  get_loop_output __P((void)); /* Read pkts from loopback */
 309 void ppp_send_config __P((int, int, u_int32_t, int, int));
 310                                 /* Configure i/f transmit parameters */
 311 void ppp_set_xaccm __P((int, ext_accm));
 312                                 /* Set extended transmit ACCM */
 313 void ppp_recv_config __P((int, int, u_int32_t, int, int));
 314                                 /* Configure i/f receive parameters */
 315 int  ccp_test __P((int, u_char *, int, int));
 316                                 /* Test support for compression scheme */
 317 void ccp_flags_set __P((int, int, int));
 318                                 /* Set kernel CCP state */
 319 int  ccp_fatal_error __P((int)); /* Test for fatal decomp error in kernel */
 320 int  get_idle_time __P((int, struct ppp_idle *));
 321                                 /* Find out how long link has been idle */
 322 int  sifvjcomp __P((int, int, int, int));
 323                                 /* Configure VJ TCP header compression */
 324 int  sifup __P((int));          /* Configure i/f up (for IP) */
 325 int  sifnpmode __P((int u, int proto, enum NPmode mode));
 326                                 /* Set mode for handling packets for proto */
 327 int  sifdown __P((int));        /* Configure i/f down (for IP) */
 328 int  sifaddr __P((int, u_int32_t, u_int32_t, u_int32_t));
 329                                 /* Configure IP addresses for i/f */
 330 int  cifaddr __P((int, u_int32_t, u_int32_t));
 331                                 /* Reset i/f IP addresses */
 332 int  sifdefaultroute __P((int, u_int32_t, u_int32_t));
 333                                 /* Create default route through i/f */
 334 int  cifdefaultroute __P((int, u_int32_t, u_int32_t));
 335                                 /* Delete default route through i/f */
 336 int  sifproxyarp __P((int, u_int32_t));
 337                                 /* Add proxy ARP entry for peer */
 338 int  cifproxyarp __P((int, u_int32_t));
 339                                 /* Delete proxy ARP entry for peer */
 340 u_int32_t GetMask __P((u_int32_t)); /* Get appropriate netmask for address */
 341 int  lock __P((char *));        /* Create lock file for device */
 342 void unlock __P((void));        /* Delete previously-created lock file */
 343 int  daemon __P((int, int));    /* Detach us from terminal session */
 344 void logwtmp __P((const char *, const char *, const char *));
 345                                 /* Write entry to wtmp file */
 346 int  get_host_seed __P((void)); /* Get host-dependent random number seed */
 347 int  have_route_to __P((u_int32_t)); /* Check if route to addr exists */
 348 void hangup_modem __P((int));   /* Make modem hang up */
 349 #ifdef PPP_FILTER
 350 int  set_filters __P((struct bpf_program *pass, struct bpf_program *active));
 351                                 /* Set filter programs in kernel */
 352 #endif
 353 #ifdef IPX_CHANGE
 354 int  sipxfaddr __P((int, unsigned long, unsigned char *));
 355 int  cipxfaddr __P((int));
 356 #endif
 357
 358 /* Procedures exported from options.c */
 359 int  parse_args __P((int argc, char **argv));
 360                                 /* Parse options from arguments given */
 361 void usage __P((void));         /* Print a usage message */
 362 int  options_from_file __P((char *filename, int must_exist, int check_prot,
 363                             int privileged));
 364                                 /* Parse options from an options file */
 365 int  options_from_user __P((void)); /* Parse options from user's .ppprc */
 366 int  options_for_tty __P((void)); /* Parse options from /etc/ppp/options.tty */
 367 void scan_args __P((int argc, char **argv));
 368                                 /* Look for tty name in command-line args */
 369 int  getword __P((FILE *f, char *word, int *newlinep, char *filename));
 370                                 /* Read a word from a file */
 371 void option_error __P((char *fmt, ...));
 372                                 /* Print an error message about an option */
 373 int number_option __P((char *, u_int32_t *, int));
 374                                 /* Parse a numerical option */
 375 int int_option __P((char *, int *));
 376                                 /* Simplified number_option for decimal ints */
 377
 378 /*
 379  * This structure is used to store information about certain
 380  * options, such as where the option value came from (/etc/ppp/options,
 381  * command line, etc.) and whether it came from a privileged source.
 382  */
 383
 384 struct option_info {
 385     int     priv;               /* was value set by sysadmin? */
 386     char    *source;            /* where option came from */
 387 };
 388
 389 extern struct option_info auth_req_info;
 390 extern struct option_info connector_info;
 391 extern struct option_info disconnector_info;
 392 extern struct option_info welcomer_info;
 393
 394 /*
 395  * Inline versions of get/put char/short/long.
 396  * Pointer is advanced; we assume that both arguments
 397  * are lvalues and will already be in registers.
 398  * cp MUST be u_char *.
 399  */
 400 #define GETCHAR(c, cp) { \
 401         (c) = *(cp)++; \
 402 }
 403 #define PUTCHAR(c, cp) { \
 404         *(cp)++ = (u_char) (c); \
 405 }
 406
 407
 408 #define GETSHORT(s, cp) { \
 409         (s) = *(cp)++ << 8; \
 410         (s) |= *(cp)++; \
 411 }
 412 #define PUTSHORT(s, cp) { \
 413         *(cp)++ = (u_char) ((s) >> 8); \
 414         *(cp)++ = (u_char) (s); \
 415 }
 416
 417 #define GETLONG(l, cp) { \
 418         (l) = *(cp)++ << 8; \
 419         (l) |= *(cp)++; (l) <<= 8; \
 420         (l) |= *(cp)++; (l) <<= 8; \
 421         (l) |= *(cp)++; \
 422 }
 423 #define PUTLONG(l, cp) { \
 424         *(cp)++ = (u_char) ((l) >> 24); \
 425         *(cp)++ = (u_char) ((l) >> 16); \
 426         *(cp)++ = (u_char) ((l) >> 8); \
 427         *(cp)++ = (u_char) (l); \
 428 }
 429
 430 #define INCPTR(n, cp)   ((cp) += (n))
 431 #define DECPTR(n, cp)   ((cp) -= (n))
 432
 433 #undef  FALSE
 434 #define FALSE   0
 435 #undef  TRUE
 436 #define TRUE    1
 437
 438 /*
 439  * System dependent definitions for user-level 4.3BSD UNIX implementation.
 440  */
 441
 442 #define DEMUXPROTREJ(u, p)      demuxprotrej(u, p)
 443
 444 #define TIMEOUT(r, f, t)        timeout((r), (f), (t))
 445 #define UNTIMEOUT(r, f)         untimeout((r), (f))
 446
 447 #define BCOPY(s, d, l)          memcpy(d, s, l)
 448 #define BZERO(s, n)             memset(s, 0, n)
 449 #define EXIT(u)                 quit()
 450
 451 #define PRINTMSG(m, l)  { m[l] = '\0'; syslog(LOG_INFO, "Remote message: %s", m); }
 452
 453 /*
 454  * MAKEHEADER - Add Header fields to a packet.
 455  */
 456 #define MAKEHEADER(p, t) { \
 457     PUTCHAR(PPP_ALLSTATIONS, p); \
 458     PUTCHAR(PPP_UI, p); \
 459     PUTSHORT(t, p); }
 460
 461
 462 #ifdef DEBUGALL
 463 #define DEBUGMAIN       1
 464 #define DEBUGFSM        1
 465 #define DEBUGLCP        1
 466 #define DEBUGIPCP       1
 467 #define DEBUGUPAP       1
 468 #define DEBUGCHAP       1
 469 #endif
 470
 471 #ifndef LOG_PPP                 /* we use LOG_LOCAL2 for syslog by default */
 472 #if defined(DEBUGMAIN) || defined(DEBUGFSM) || defined(DEBUGSYS) \
 473   || defined(DEBUGLCP) || defined(DEBUGIPCP) || defined(DEBUGUPAP) \
 474   || defined(DEBUGCHAP) || defined(DEBUG)
 475 #define LOG_PPP LOG_LOCAL2
 476 #else
 477 #define LOG_PPP LOG_DAEMON
 478 #endif
 479 #endif /* LOG_PPP */
 480
 481 #ifdef DEBUGMAIN
 482 #define MAINDEBUG(x)    if (debug) syslog x
 483 #else
 484 #define MAINDEBUG(x)
 485 #endif
 486
 487 #ifdef DEBUGSYS
 488 #define SYSDEBUG(x)     if (debug) syslog x
 489 #else
 490 #define SYSDEBUG(x)
 491 #endif
 492
 493 #ifdef DEBUGFSM
 494 #define FSMDEBUG(x)     if (debug) syslog x
 495 #else
 496 #define FSMDEBUG(x)
 497 #endif
 498
 499 #ifdef DEBUGLCP
 500 #define LCPDEBUG(x)     if (debug) syslog x
 501 #else
 502 #define LCPDEBUG(x)
 503 #endif
 504
 505 #ifdef DEBUGIPCP
 506 #define IPCPDEBUG(x)    if (debug) syslog x
 507 #else
 508 #define IPCPDEBUG(x)
 509 #endif
 510
 511 #ifdef DEBUGUPAP
 512 #define UPAPDEBUG(x)    if (debug) syslog x
 513 #else
 514 #define UPAPDEBUG(x)
 515 #endif
 516
 517 #ifdef DEBUGCHAP
 518 #define CHAPDEBUG(x)    if (debug) syslog x
 519 #else
 520 #define CHAPDEBUG(x)
 521 #endif
 522
 523 #ifdef DEBUGIPXCP
 524 #define IPXCPDEBUG(x)   if (debug) syslog x
 525 #else
 526 #define IPXCPDEBUG(x)
 527 #endif
 528
 529 #ifndef SIGTYPE
 530 #if defined(sun) || defined(SYSV) || defined(POSIX_SOURCE)
 531 #define SIGTYPE void
 532 #else
 533 #define SIGTYPE int
 534 #endif /* defined(sun) || defined(SYSV) || defined(POSIX_SOURCE) */
 535 #endif /* SIGTYPE */
 536
 537 #ifndef MIN
 538 #define MIN(a, b)       ((a) < (b)? (a): (b))
 539 #endif
 540 #ifndef MAX
 541 #define MAX(a, b)       ((a) > (b)? (a): (b))
 542 #endif
 543
 544 #endif /* __PPP_H__ */