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     nd_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 = {
 148         NULL,   /* version */
 149         0,      /* numfields */
 150         0,      /* kind */
 151         NULL,   /* uid */
 152         0,      /* port */
 153         0,      /* auth */
 154         0,      /* authlen */
 155         NULL,   /* authdata */
 156         NULL,   /* class */
 157         NULL,   /* inst */
 158         NULL,   /* opcode */
 159         NULL,   /* sender */
 160         NULL,   /* recipient */
 161         NULL,   /* format */
 162         0,      /* cksum */
 163         0,      /* multi */
 164         NULL    /* multi_uid */
 165     };
 166     const char *parse = (const char *) cp;
 167     int parselen = length;
 168     const char *s;
 169     int lose = 0;
 170     int truncated = 0;
 171
 172     ndo->ndo_protocol = "zephyr";
 173     /* squelch compiler warnings */
 174
 175 #define PARSE_STRING                                            \
 176         s = parse_field(ndo, &parse, &parselen, &truncated);    \
 177         if (truncated) goto trunc;                              \
 178         if (!s) lose = 1;
 179
 180 #define PARSE_FIELD_INT(field)                  \
 181         PARSE_STRING                            \
 182         if (!lose) field = strtol(s, 0, 16);
 183
 184 #define PARSE_FIELD_STR(field)                  \
 185         PARSE_STRING                            \
 186         if (!lose) field = s;
 187
 188     PARSE_FIELD_STR(z.version);
 189     if (lose) return;
 190     if (strncmp(z.version, "ZEPH", 4))
 191         return;
 192
 193     PARSE_FIELD_INT(z.numfields);
 194     PARSE_FIELD_INT(z.kind);
 195     PARSE_FIELD_STR(z.uid);
 196     PARSE_FIELD_INT(z.port);
 197     PARSE_FIELD_INT(z.auth);
 198     PARSE_FIELD_INT(z.authlen);
 199     PARSE_FIELD_STR(z.authdata);
 200     PARSE_FIELD_STR(z.class);
 201     PARSE_FIELD_STR(z.inst);
 202     PARSE_FIELD_STR(z.opcode);
 203     PARSE_FIELD_STR(z.sender);
 204     PARSE_FIELD_STR(z.recipient);
 205     PARSE_FIELD_STR(z.format);
 206     PARSE_FIELD_INT(z.cksum);
 207     PARSE_FIELD_INT(z.multi);
 208     PARSE_FIELD_STR(z.multi_uid);
 209
 210     if (lose)
 211         goto trunc;
 212
 213     ND_PRINT(" zephyr");
 214     if (strncmp(z.version+4, "0.2", 3)) {
 215         ND_PRINT(" v%s", z.version+4);
 216         return;
 217     }
 218
 219     ND_PRINT(" %s", tok2str(z_types, "type %d", z.kind));
 220     if (z.kind == Z_PACKET_SERVACK) {
 221         /* Initialization to silence warnings */
 222         const char *ackdata = NULL;
 223         PARSE_FIELD_STR(ackdata);
 224         if (!lose && strcmp(ackdata, "SENT"))
 225             ND_PRINT("/%s", str_to_lower(ackdata));
 226     }
 227     if (*z.sender) ND_PRINT(" %s", z.sender);
 228
 229     if (!strcmp(z.class, "USER_LOCATE")) {
 230         if (!strcmp(z.opcode, "USER_HIDE"))
 231             ND_PRINT(" hide");
 232         else if (!strcmp(z.opcode, "USER_UNHIDE"))
 233             ND_PRINT(" unhide");
 234         else
 235             ND_PRINT(" locate %s", z.inst);
 236         return;
 237     }
 238
 239     if (!strcmp(z.class, "ZEPHYR_ADMIN")) {
 240         ND_PRINT(" zephyr-admin %s", str_to_lower(z.opcode));
 241         return;
 242     }
 243
 244     if (!strcmp(z.class, "ZEPHYR_CTL")) {
 245         if (!strcmp(z.inst, "CLIENT")) {
 246             if (!strcmp(z.opcode, "SUBSCRIBE") ||
 247                 !strcmp(z.opcode, "SUBSCRIBE_NODEFS") ||
 248                 !strcmp(z.opcode, "UNSUBSCRIBE")) {
 249
 250                 ND_PRINT(" %ssub%s", strcmp(z.opcode, "SUBSCRIBE") ? "un" : "",
 251                                    strcmp(z.opcode, "SUBSCRIBE_NODEFS") ? "" :
 252                                                                    "-nodefs");
 253                 if (z.kind != Z_PACKET_SERVACK) {
 254                     /* Initialization to silence warnings */
 255                     const char *c = NULL, *i = NULL, *r = NULL;
 256                     PARSE_FIELD_STR(c);
 257                     PARSE_FIELD_STR(i);
 258                     PARSE_FIELD_STR(r);
 259                     if (!lose) ND_PRINT(" %s", z_triple(c, i, r));
 260                 }
 261                 return;
 262             }
 263
 264             if (!strcmp(z.opcode, "GIMME")) {
 265                 ND_PRINT(" ret");
 266                 return;
 267             }
 268
 269             if (!strcmp(z.opcode, "GIMMEDEFS")) {
 270                 ND_PRINT(" gimme-defs");
 271                 return;
 272             }
 273
 274             if (!strcmp(z.opcode, "CLEARSUB")) {
 275                 ND_PRINT(" clear-subs");
 276                 return;
 277             }
 278
 279             ND_PRINT(" %s", str_to_lower(z.opcode));
 280             return;
 281         }
 282
 283         if (!strcmp(z.inst, "HM")) {
 284             ND_PRINT(" %s", str_to_lower(z.opcode));
 285             return;
 286         }
 287
 288         if (!strcmp(z.inst, "REALM")) {
 289             if (!strcmp(z.opcode, "ADD_SUBSCRIBE"))
 290                 ND_PRINT(" realm add-subs");
 291             if (!strcmp(z.opcode, "REQ_SUBSCRIBE"))
 292                 ND_PRINT(" realm req-subs");
 293             if (!strcmp(z.opcode, "RLM_SUBSCRIBE"))
 294                 ND_PRINT(" realm rlm-sub");
 295             if (!strcmp(z.opcode, "RLM_UNSUBSCRIBE"))
 296                 ND_PRINT(" realm rlm-unsub");
 297             return;
 298         }
 299     }
 300
 301     if (!strcmp(z.class, "HM_CTL")) {
 302         ND_PRINT(" hm_ctl %s", str_to_lower(z.inst));
 303         ND_PRINT(" %s", str_to_lower(z.opcode));
 304         return;
 305     }
 306
 307     if (!strcmp(z.class, "HM_STAT")) {
 308         if (!strcmp(z.inst, "HMST_CLIENT") && !strcmp(z.opcode, "GIMMESTATS")) {
 309             ND_PRINT(" get-client-stats");
 310             return;
 311         }
 312     }
 313
 314     if (!strcmp(z.class, "WG_CTL")) {
 315         ND_PRINT(" wg_ctl %s", str_to_lower(z.inst));
 316         ND_PRINT(" %s", str_to_lower(z.opcode));
 317         return;
 318     }
 319
 320     if (!strcmp(z.class, "LOGIN")) {
 321         if (!strcmp(z.opcode, "USER_FLUSH")) {
 322             ND_PRINT(" flush_locs");
 323             return;
 324         }
 325
 326         if (!strcmp(z.opcode, "NONE") ||
 327             !strcmp(z.opcode, "OPSTAFF") ||
 328             !strcmp(z.opcode, "REALM-VISIBLE") ||
 329             !strcmp(z.opcode, "REALM-ANNOUNCED") ||
 330             !strcmp(z.opcode, "NET-VISIBLE") ||
 331             !strcmp(z.opcode, "NET-ANNOUNCED")) {
 332             ND_PRINT(" set-exposure %s", str_to_lower(z.opcode));
 333             return;
 334         }
 335     }
 336
 337     if (!*z.recipient)
 338         z.recipient = "*";
 339
 340     ND_PRINT(" to %s", z_triple(z.class, z.inst, z.recipient));
 341     if (*z.opcode)
 342         ND_PRINT(" op %s", z.opcode);
 343     return;
 344
 345 trunc:
 346     ND_PRINT(" [|zephyr] (%d)", length);
 347     return;
 348 }