The Tcpdump Group git mirrors - tcpdump/blob - print-zephyr.c

   1 /*
   2  * Decode and print Zephyr packets.
   3  *
   4  *      http://web.mit.edu/zephyr/doc/protocol
   5  *
   6  * Copyright (c) 2001 Nickolai Zeldovich <kolya@MIT.EDU>
   7  * All rights reserved.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that: (1) source code
  11  * distributions retain the above copyright notice and this paragraph
  12  * in its entirety, and (2) distributions including binary code include
  13  * the above copyright notice and this paragraph in its entirety in
  14  * the documentation or other materials provided with the distribution.
  15  * The name of the author(s) may not be used to endorse or promote
  16  * products derived from this software without specific prior written
  17  * permission.  THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY
  18  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  20  * PURPOSE.
  21  */
  22
  23 /* \summary: Zephyr printer */
  24
  25 #ifdef HAVE_CONFIG_H
  26 #include "config.h"
  27 #endif
  28
  29 #include <netdissect-stdinc.h>
  30
  31 #include <stdio.h>
  32 #include <string.h>
  33 #include <stdlib.h>
  34
  35 #include "netdissect.h"
  36
  37 struct z_packet {
  38     const char *version;
  39     int numfields;
  40     int kind;
  41     const char *uid;
  42     int port;
  43     int auth;
  44     int authlen;
  45     const char *authdata;
  46     const char *class;
  47     const char *inst;
  48     const char *opcode;
  49     const char *sender;
  50     const char *recipient;
  51     const char *format;
  52     int cksum;
  53     int multi;
  54     const char *multi_uid;
  55     /* Other fields follow here.. */
  56 };
  57
  58 enum z_packet_type {
  59     Z_PACKET_UNSAFE = 0,
  60     Z_PACKET_UNACKED,
  61     Z_PACKET_ACKED,
  62     Z_PACKET_HMACK,
  63     Z_PACKET_HMCTL,
  64     Z_PACKET_SERVACK,
  65     Z_PACKET_SERVNAK,
  66     Z_PACKET_CLIENTACK,
  67     Z_PACKET_STAT
  68 };
  69
  70 static const struct tok z_types[] = {
  71     { Z_PACKET_UNSAFE,          "unsafe" },
  72     { Z_PACKET_UNACKED,         "unacked" },
  73     { Z_PACKET_ACKED,           "acked" },
  74     { Z_PACKET_HMACK,           "hm-ack" },
  75     { Z_PACKET_HMCTL,           "hm-ctl" },
  76     { Z_PACKET_SERVACK,         "serv-ack" },
  77     { Z_PACKET_SERVNAK,         "serv-nak" },
  78     { Z_PACKET_CLIENTACK,       "client-ack" },
  79     { Z_PACKET_STAT,            "stat" },
  80     { 0,                        NULL }
  81 };
  82
  83 static char z_buf[256];
  84
  85 static const char *
  86 parse_field(netdissect_options *ndo, const char **pptr, int *len, int *truncated)
  87 {
  88     const char *s;
  89
  90     /* Start of string */
  91     s = *pptr;
  92     /* Scan for the NUL terminator */
  93     for (;;) {
  94         if (*len == 0) {
  95             /* Ran out of packet data without finding it */
  96             return NULL;
  97         }
  98         if (!ND_TTEST_SIZE(*pptr)) {
  99             /* Ran out of captured data without finding it */
 100             *truncated = 1;
 101             return NULL;
 102         }
 103         if (**pptr == '\0') {
 104             /* Found it */
 105             break;
 106         }
 107         /* Keep scanning */
 108         (*pptr)++;
 109         (*len)--;
 110     }
 111     /* Skip the NUL terminator */
 112     (*pptr)++;
 113     (*len)--;
 114     return s;
 115 }
 116
 117 static const char *
 118 z_triple(const char *class, const char *inst, const char *recipient)
 119 {
 120     if (!*recipient)
 121         recipient = "*";
 122     snprintf(z_buf, sizeof(z_buf), "<%s,%s,%s>", class, inst, recipient);
 123     z_buf[sizeof(z_buf)-1] = '\0';
 124     return z_buf;
 125 }
 126
 127 static const char *
 128 str_to_lower(const char *string)
 129 {
 130     char *zb_string;
 131
 132     strncpy(z_buf, string, sizeof(z_buf));
 133     z_buf[sizeof(z_buf)-1] = '\0';
 134
 135     zb_string = z_buf;
 136     while (*zb_string) {
 137         *zb_string = tolower((unsigned char)(*zb_string));
 138         zb_string++;
 139     }
 140
 141     return z_buf;
 142 }
 143
 144 void
 145 zephyr_print(netdissect_options *ndo, const u_char *cp, int length)
 146 {
 147     struct z_packet z = {0};
 148     const char *parse = (const char *) cp;
 149     int parselen = length;
 150     const char *s;
 151     int lose = 0;
 152     int truncated = 0;
 153
 154     /* squelch compiler warnings */
 155
 156 #define PARSE_STRING                                            \
 157         s = parse_field(ndo, &parse, &parselen, &truncated);    \
 158         if (truncated) goto trunc;                              \
 159         if (!s) lose = 1;
 160
 161 #define PARSE_FIELD_INT(field)                  \
 162         PARSE_STRING                            \
 163         if (!lose) field = strtol(s, 0, 16);
 164
 165 #define PARSE_FIELD_STR(field)                  \
 166         PARSE_STRING                            \
 167         if (!lose) field = s;
 168
 169     PARSE_FIELD_STR(z.version);
 170     if (lose) return;
 171     if (strncmp(z.version, "ZEPH", 4))
 172         return;
 173
 174     PARSE_FIELD_INT(z.numfields);
 175     PARSE_FIELD_INT(z.kind);
 176     PARSE_FIELD_STR(z.uid);
 177     PARSE_FIELD_INT(z.port);
 178     PARSE_FIELD_INT(z.auth);
 179     PARSE_FIELD_INT(z.authlen);
 180     PARSE_FIELD_STR(z.authdata);
 181     PARSE_FIELD_STR(z.class);
 182     PARSE_FIELD_STR(z.inst);
 183     PARSE_FIELD_STR(z.opcode);
 184     PARSE_FIELD_STR(z.sender);
 185     PARSE_FIELD_STR(z.recipient);
 186     PARSE_FIELD_STR(z.format);
 187     PARSE_FIELD_INT(z.cksum);
 188     PARSE_FIELD_INT(z.multi);
 189     PARSE_FIELD_STR(z.multi_uid);
 190
 191     if (lose)
 192         goto trunc;
 193
 194     ND_PRINT(" zephyr");
 195     if (strncmp(z.version+4, "0.2", 3)) {
 196         ND_PRINT(" v%s", z.version+4);
 197         return;
 198     }
 199
 200     ND_PRINT(" %s", tok2str(z_types, "type %d", z.kind));
 201     if (z.kind == Z_PACKET_SERVACK) {
 202         /* Initialization to silence warnings */
 203         const char *ackdata = NULL;
 204         PARSE_FIELD_STR(ackdata);
 205         if (!lose && strcmp(ackdata, "SENT"))
 206             ND_PRINT("/%s", str_to_lower(ackdata));
 207     }
 208     if (*z.sender) ND_PRINT(" %s", z.sender);
 209
 210     if (!strcmp(z.class, "USER_LOCATE")) {
 211         if (!strcmp(z.opcode, "USER_HIDE"))
 212             ND_PRINT(" hide");
 213         else if (!strcmp(z.opcode, "USER_UNHIDE"))
 214             ND_PRINT(" unhide");
 215         else
 216             ND_PRINT(" locate %s", z.inst);
 217         return;
 218     }
 219
 220     if (!strcmp(z.class, "ZEPHYR_ADMIN")) {
 221         ND_PRINT(" zephyr-admin %s", str_to_lower(z.opcode));
 222         return;
 223     }
 224
 225     if (!strcmp(z.class, "ZEPHYR_CTL")) {
 226         if (!strcmp(z.inst, "CLIENT")) {
 227             if (!strcmp(z.opcode, "SUBSCRIBE") ||
 228                 !strcmp(z.opcode, "SUBSCRIBE_NODEFS") ||
 229                 !strcmp(z.opcode, "UNSUBSCRIBE")) {
 230
 231                 ND_PRINT(" %ssub%s", strcmp(z.opcode, "SUBSCRIBE") ? "un" : "",
 232                                    strcmp(z.opcode, "SUBSCRIBE_NODEFS") ? "" :
 233                                                                    "-nodefs");
 234                 if (z.kind != Z_PACKET_SERVACK) {
 235                     /* Initialization to silence warnings */
 236                     const char *c = NULL, *i = NULL, *r = NULL;
 237                     PARSE_FIELD_STR(c);
 238                     PARSE_FIELD_STR(i);
 239                     PARSE_FIELD_STR(r);
 240                     if (!lose) ND_PRINT(" %s", z_triple(c, i, r));
 241                 }
 242                 return;
 243             }
 244
 245             if (!strcmp(z.opcode, "GIMME")) {
 246                 ND_PRINT(" ret");
 247                 return;
 248             }
 249
 250             if (!strcmp(z.opcode, "GIMMEDEFS")) {
 251                 ND_PRINT(" gimme-defs");
 252                 return;
 253             }
 254
 255             if (!strcmp(z.opcode, "CLEARSUB")) {
 256                 ND_PRINT(" clear-subs");
 257                 return;
 258             }
 259
 260             ND_PRINT(" %s", str_to_lower(z.opcode));
 261             return;
 262         }
 263
 264         if (!strcmp(z.inst, "HM")) {
 265             ND_PRINT(" %s", str_to_lower(z.opcode));
 266             return;
 267         }
 268
 269         if (!strcmp(z.inst, "REALM")) {
 270             if (!strcmp(z.opcode, "ADD_SUBSCRIBE"))
 271                 ND_PRINT(" realm add-subs");
 272             if (!strcmp(z.opcode, "REQ_SUBSCRIBE"))
 273                 ND_PRINT(" realm req-subs");
 274             if (!strcmp(z.opcode, "RLM_SUBSCRIBE"))
 275                 ND_PRINT(" realm rlm-sub");
 276             if (!strcmp(z.opcode, "RLM_UNSUBSCRIBE"))
 277                 ND_PRINT(" realm rlm-unsub");
 278             return;
 279         }
 280     }
 281
 282     if (!strcmp(z.class, "HM_CTL")) {
 283         ND_PRINT(" hm_ctl %s", str_to_lower(z.inst));
 284         ND_PRINT(" %s", str_to_lower(z.opcode));
 285         return;
 286     }
 287
 288     if (!strcmp(z.class, "HM_STAT")) {
 289         if (!strcmp(z.inst, "HMST_CLIENT") && !strcmp(z.opcode, "GIMMESTATS")) {
 290             ND_PRINT(" get-client-stats");
 291             return;
 292         }
 293     }
 294
 295     if (!strcmp(z.class, "WG_CTL")) {
 296         ND_PRINT(" wg_ctl %s", str_to_lower(z.inst));
 297         ND_PRINT(" %s", str_to_lower(z.opcode));
 298         return;
 299     }
 300
 301     if (!strcmp(z.class, "LOGIN")) {
 302         if (!strcmp(z.opcode, "USER_FLUSH")) {
 303             ND_PRINT(" flush_locs");
 304             return;
 305         }
 306
 307         if (!strcmp(z.opcode, "NONE") ||
 308             !strcmp(z.opcode, "OPSTAFF") ||
 309             !strcmp(z.opcode, "REALM-VISIBLE") ||
 310             !strcmp(z.opcode, "REALM-ANNOUNCED") ||
 311             !strcmp(z.opcode, "NET-VISIBLE") ||
 312             !strcmp(z.opcode, "NET-ANNOUNCED")) {
 313             ND_PRINT(" set-exposure %s", str_to_lower(z.opcode));
 314             return;
 315         }
 316     }
 317
 318     if (!*z.recipient)
 319         z.recipient = "*";
 320
 321     ND_PRINT(" to %s", z_triple(z.class, z.inst, z.recipient));
 322     if (*z.opcode)
 323         ND_PRINT(" op %s", z.opcode);
 324     return;
 325
 326 trunc:
 327     ND_PRINT(" [|zephyr] (%d)", length);
 328     return;
 329 }