pktlength.c

   1 /*
   2   chronyd/chronyc - Programs for keeping computer clocks accurate.
   3
   4  **********************************************************************
   5  * Copyright (C) Richard P. Curnow  1997-2002
   6  * Copyright (C) Miroslav Lichvar  2014-2016
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of version 2 of the GNU General Public License as
  10  * published by the Free Software Foundation.
  11  *
  12  * This program is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License along
  18  * with this program; if not, write to the Free Software Foundation, Inc.,
  19  * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  20  *
  21  **********************************************************************
  22
  23   =======================================================================
  24
  25   Routines to compute the expected length of a command or reply packet.
  26   These operate on the RAW NETWORK packets, from the point of view of
  27   integer endianness within the structures.
  28
  29   */
  30 #include "config.h"
  31
  32 #include "sysincl.h"
  33
  34 #include "util.h"
  35 #include "pktlength.h"
  36
  37 #define PADDING_LENGTH_(request_length, reply_length) \
  38   (uint16_t)((request_length) < (reply_length) ? (reply_length) - (request_length) : 0)
  39
  40 #define PADDING_LENGTH(request_data, reply_data) \
  41   PADDING_LENGTH_(offsetof(CMD_Request, request_data), offsetof(CMD_Reply, reply_data))
  42
  43 #define REQ_LENGTH_ENTRY(request_data_field, reply_data_field) \
  44   { offsetof(CMD_Request, data.request_data_field.EOR), \
  45     PADDING_LENGTH(data.request_data_field.EOR, data.reply_data_field.EOR) }
  46
  47 #define RPY_LENGTH_ENTRY(reply_data_field) \
  48   offsetof(CMD_Reply, data.reply_data_field.EOR)
  49
  50 /* ================================================== */
  51
  52 struct request_length {
  53   uint16_t command;
  54   uint16_t padding;
  55 };
  56
  57 static const struct request_length request_lengths[] = {
  58   REQ_LENGTH_ENTRY(null, null),                 /* NULL */
  59   REQ_LENGTH_ENTRY(online, null),               /* ONLINE */
  60   REQ_LENGTH_ENTRY(offline, null),              /* OFFLINE */
  61   REQ_LENGTH_ENTRY(burst, null),                /* BURST */
  62   REQ_LENGTH_ENTRY(modify_minpoll, null),       /* MODIFY_MINPOLL */
  63   REQ_LENGTH_ENTRY(modify_maxpoll, null),       /* MODIFY_MAXPOLL */
  64   REQ_LENGTH_ENTRY(dump, null),                 /* DUMP */
  65   REQ_LENGTH_ENTRY(modify_maxdelay, null),      /* MODIFY_MAXDELAY */
  66   REQ_LENGTH_ENTRY(modify_maxdelayratio, null), /* MODIFY_MAXDELAYRATIO */
  67   REQ_LENGTH_ENTRY(modify_maxupdateskew, null), /* MODIFY_MAXUPDATESKEW */
  68   REQ_LENGTH_ENTRY(logon, null),                /* LOGON */
  69   REQ_LENGTH_ENTRY(settime, manual_timestamp),  /* SETTIME */
  70   { 0, 0 },                                     /* LOCAL */
  71   REQ_LENGTH_ENTRY(manual, null),               /* MANUAL */
  72   REQ_LENGTH_ENTRY(null, n_sources),            /* N_SOURCES */
  73   REQ_LENGTH_ENTRY(source_data, source_data),   /* SOURCE_DATA */
  74   REQ_LENGTH_ENTRY(null, null),                 /* REKEY */
  75   REQ_LENGTH_ENTRY(allow_deny, null),           /* ALLOW */
  76   REQ_LENGTH_ENTRY(allow_deny, null),           /* ALLOWALL */
  77   REQ_LENGTH_ENTRY(allow_deny, null),           /* DENY */
  78   REQ_LENGTH_ENTRY(allow_deny, null),           /* DENYALL */
  79   REQ_LENGTH_ENTRY(allow_deny, null),           /* CMDALLOW */
  80   REQ_LENGTH_ENTRY(allow_deny, null),           /* CMDALLOWALL */
  81   REQ_LENGTH_ENTRY(allow_deny, null),           /* CMDDENY */
  82   REQ_LENGTH_ENTRY(allow_deny, null),           /* CMDDENYALL */
  83   REQ_LENGTH_ENTRY(ac_check, null),             /* ACCHECK */
  84   REQ_LENGTH_ENTRY(ac_check, null),             /* CMDACCHECK */
  85   { 0, 0 },                                     /* ADD_SERVER */
  86   { 0, 0 },                                     /* ADD_PEER */
  87   REQ_LENGTH_ENTRY(del_source, null),           /* DEL_SOURCE */
  88   REQ_LENGTH_ENTRY(null, null),                 /* WRITERTC */
  89   REQ_LENGTH_ENTRY(dfreq, null),                /* DFREQ */
  90   REQ_LENGTH_ENTRY(doffset, null),              /* DOFFSET */
  91   REQ_LENGTH_ENTRY(null, tracking),             /* TRACKING */
  92   REQ_LENGTH_ENTRY(sourcestats, sourcestats),   /* SOURCESTATS */
  93   REQ_LENGTH_ENTRY(null, rtc),                  /* RTCREPORT */
  94   REQ_LENGTH_ENTRY(null, null),                 /* TRIMRTC */
  95   REQ_LENGTH_ENTRY(null, null),                 /* CYCLELOGS */
  96   { 0, 0 },                                     /* SUBNETS_ACCESSED - not supported */
  97   { 0, 0 },                                     /* CLIENT_ACCESSES - not supported */
  98   { 0, 0 },                                     /* CLIENT_ACCESSES_BY_INDEX - not supported */
  99   REQ_LENGTH_ENTRY(null, manual_list),          /* MANUAL_LIST */
 100   REQ_LENGTH_ENTRY(manual_delete, null),        /* MANUAL_DELETE */
 101   REQ_LENGTH_ENTRY(null, null),                 /* MAKESTEP */
 102   REQ_LENGTH_ENTRY(null, activity),             /* ACTIVITY */
 103   REQ_LENGTH_ENTRY(modify_minstratum, null),    /* MODIFY_MINSTRATUM */
 104   REQ_LENGTH_ENTRY(modify_polltarget, null),    /* MODIFY_POLLTARGET */
 105   REQ_LENGTH_ENTRY(modify_maxdelaydevratio, null), /* MODIFY_MAXDELAYDEVRATIO */
 106   REQ_LENGTH_ENTRY(null, null),                 /* RESELECT */
 107   REQ_LENGTH_ENTRY(reselect_distance, null),    /* RESELECTDISTANCE */
 108   REQ_LENGTH_ENTRY(modify_makestep, null),      /* MODIFY_MAKESTEP */
 109   REQ_LENGTH_ENTRY(null, smoothing),            /* SMOOTHING */
 110   REQ_LENGTH_ENTRY(smoothtime, null),           /* SMOOTHTIME */
 111   REQ_LENGTH_ENTRY(null, null),                 /* REFRESH */
 112   REQ_LENGTH_ENTRY(null, server_stats),         /* SERVER_STATS */
 113   REQ_LENGTH_ENTRY(client_accesses_by_index,
 114                    client_accesses_by_index),   /* CLIENT_ACCESSES_BY_INDEX2 */
 115   REQ_LENGTH_ENTRY(local, null),                /* LOCAL2 */
 116   REQ_LENGTH_ENTRY(ntp_data, ntp_data),         /* NTP_DATA */
 117   { 0, 0 },                                     /* ADD_SERVER2 */
 118   { 0, 0 },                                     /* ADD_PEER2 */
 119   { 0, 0 },                                     /* ADD_SERVER3 */
 120   { 0, 0 },                                     /* ADD_PEER3 */
 121   REQ_LENGTH_ENTRY(null, null),                 /* SHUTDOWN */
 122   REQ_LENGTH_ENTRY(null, null),                 /* ONOFFLINE */
 123   REQ_LENGTH_ENTRY(ntp_source, null),           /* ADD_SOURCE */
 124   REQ_LENGTH_ENTRY(ntp_source_name,
 125                    ntp_source_name),            /* NTP_SOURCE_NAME */
 126   REQ_LENGTH_ENTRY(null, null),                 /* RESET */
 127 };
 128
 129 static const uint16_t reply_lengths[] = {
 130   0,                                            /* empty slot */
 131   RPY_LENGTH_ENTRY(null),                       /* NULL */
 132   RPY_LENGTH_ENTRY(n_sources),                  /* N_SOURCES */
 133   RPY_LENGTH_ENTRY(source_data),                /* SOURCE_DATA */
 134   0,                                            /* MANUAL_TIMESTAMP */
 135   RPY_LENGTH_ENTRY(tracking),                   /* TRACKING */
 136   RPY_LENGTH_ENTRY(sourcestats),                /* SOURCESTATS */
 137   RPY_LENGTH_ENTRY(rtc),                        /* RTC */
 138   0,                                            /* SUBNETS_ACCESSED - not supported */
 139   0,                                            /* CLIENT_ACCESSES - not supported */
 140   0,                                            /* CLIENT_ACCESSES_BY_INDEX - not supported */
 141   0,                                            /* MANUAL_LIST - not supported */
 142   RPY_LENGTH_ENTRY(activity),                   /* ACTIVITY */
 143   RPY_LENGTH_ENTRY(smoothing),                  /* SMOOTHING */
 144   RPY_LENGTH_ENTRY(server_stats),               /* SERVER_STATS */
 145   RPY_LENGTH_ENTRY(client_accesses_by_index),   /* CLIENT_ACCESSES_BY_INDEX2 */
 146   RPY_LENGTH_ENTRY(ntp_data),                   /* NTP_DATA */
 147   RPY_LENGTH_ENTRY(manual_timestamp),           /* MANUAL_TIMESTAMP2 */
 148   RPY_LENGTH_ENTRY(manual_list),                /* MANUAL_LIST2 */
 149   RPY_LENGTH_ENTRY(ntp_source_name),            /* NTP_SOURCE_NAME */
 150 };
 151
 152 /* ================================================== */
 153
 154 int
 155 PKL_CommandLength(CMD_Request *r)
 156 {
 157   uint32_t type;
 158   int command_length;
 159
 160   assert(sizeof (request_lengths) / sizeof (request_lengths[0]) == N_REQUEST_TYPES);
 161
 162   type = ntohs(r->command);
 163   if (type >= N_REQUEST_TYPES)
 164     return 0;
 165
 166   command_length = request_lengths[type].command;
 167   if (!command_length)
 168     return 0;
 169
 170   return command_length + PKL_CommandPaddingLength(r);
 171 }
 172
 173 /* ================================================== */
 174
 175 int
 176 PKL_CommandPaddingLength(CMD_Request *r)
 177 {
 178   uint32_t type;
 179
 180   if (r->version < PROTO_VERSION_PADDING)
 181     return 0;
 182
 183   type = ntohs(r->command);
 184
 185   if (type >= N_REQUEST_TYPES)
 186     return 0;
 187
 188   return request_lengths[ntohs(r->command)].padding;
 189 }
 190
 191 /* ================================================== */
 192
 193 int
 194 PKL_ReplyLength(CMD_Reply *r)
 195 {
 196   uint32_t type;
 197
 198   assert(sizeof (reply_lengths) / sizeof (reply_lengths[0]) == N_REPLY_TYPES);
 199
 200   type = ntohs(r->reply);
 201
 202   /* Note that reply type codes start from 1, not 0 */
 203   if (type < 1 || type >= N_REPLY_TYPES)
 204     return 0;
 205
 206   return reply_lengths[type];
 207 }
 208
 209 /* ================================================== */
 210