packet/probe.h

   1 /*
   2     mtr  --  a network diagnostic tool
   3     Copyright (C) 2016  Matt Kimball
   4
   5     This program is free software; you can redistribute it and/or modify
   6     it under the terms of the GNU General Public License version 2 as
   7     published by the Free Software Foundation.
   8
   9     This program is distributed in the hope that it will be useful,
  10     but WITHOUT ANY WARRANTY; without even the implied warranty of
  11     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12     GNU General Public License for more details.
  13
  14     You should have received a copy of the GNU General Public License along
  15     with this program; if not, write to the Free Software Foundation, Inc.,
  16     51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  17 */
  18
  19 #ifndef PROBE_H
  20 #define PROBE_H
  21
  22 #include "platform.h"
  23
  24 #include <netinet/in.h>
  25 #include <stdbool.h>
  26 #include <sys/socket.h>
  27 #include <sys/time.h>
  28
  29 #include "portability/queue.h"
  30
  31 #ifdef PLATFORM_CYGWIN
  32 #include "probe_cygwin.h"
  33 #else
  34 #include "probe_unix.h"
  35 #endif
  36
  37 #define MAX_PROBES 1024
  38
  39 /*  Use the "jumbo" frame size as the max packet size  */
  40 #define PACKET_BUFFER_SIZE 9000
  41
  42 /*  Parameters for sending a new probe  */
  43 struct probe_param_t {
  44     /*  The version of the Internet Protocol to use.  (4 or 6)  */
  45     int ip_version;
  46
  47     /*  The command token used to identify a probe when it is completed  */
  48     int command_token;
  49
  50     /*  The IP address to probe  */
  51     const char *remote_address;
  52
  53     /*  The local address from which to send probes  */
  54     const char *local_address;
  55
  56     /*  The local device from which to send probes  */
  57     const char *local_device;
  58
  59     /*  Protocol for the probe, using the IPPROTO_* defines  */
  60     int protocol;
  61
  62     /*  The destination port for non-ICMP probes  */
  63     int dest_port;
  64
  65     /*  The local port number to use when sending probes  */
  66     int local_port;
  67
  68     /*  The "type of service" field in the IP header  */
  69     int type_of_service;
  70
  71     /*  The packet "mark" used for mark-based routing on Linux  */
  72     uint32_t routing_mark;
  73
  74     /*  Time to live for the transmitted probe  */
  75     int ttl;
  76
  77     /*  The packet size (in bytes) including protocol headers  */
  78     int packet_size;
  79
  80     /*  The value with which to fill the bytes of the packet.  */
  81     int bit_pattern;
  82
  83     /*  The number of seconds to wait before assuming the probe was lost  */
  84     int timeout;
  85
  86     /*  true is the probe is to test byte order */
  87     bool is_probing_byte_order;
  88 };
  89
  90 /*  Tracking information for an outstanding probe  */
  91 struct probe_t {
  92     /*  Our entry in the probe list  */
  93     LIST_ENTRY(
  94     probe_t) probe_list_entry;
  95
  96     /*
  97        Also the ICMP sequence ID used to identify the probe.
  98
  99        Also used as the port number to use when binding stream protocol
 100        sockets for this probe.  (i.e. TCP or SCTP)
 101      */
 102     int sequence;
 103
 104     /*  Command token of the probe request  */
 105     int token;
 106
 107     /*  The address being probed  */
 108     struct sockaddr_storage remote_addr;
 109
 110     /* The local address which was used */
 111     struct sockaddr_storage local_addr;
 112
 113
 114     /*  Platform specific probe tracking  */
 115     struct probe_platform_t platform;
 116 };
 117
 118 /*  Global state for interacting with the network  */
 119 struct net_state_t {
 120     /*  The number of entries in the outstanding_probes list  */
 121     int outstanding_probe_count;
 122
 123     /*  Tracking information for in-flight probes  */
 124      LIST_HEAD(
 125     probe_list_head_t,
 126     probe_t) outstanding_probes;
 127
 128     /*  Platform specific tracking information  */
 129     struct net_state_platform_t platform;
 130 };
 131
 132 /*  Multiprotocol Label Switching information  */
 133 struct mpls_label_t {
 134     uint32_t label;
 135     uint8_t traffic_class;
 136     uint8_t bottom_of_stack;
 137     uint8_t ttl;
 138 };
 139
 140 void init_net_state_privileged(
 141     struct net_state_t *net_state);
 142
 143 void init_net_state(
 144     struct net_state_t *net_state);
 145
 146 bool is_ip_version_supported(
 147     struct net_state_t *net_state,
 148     int ip_version);
 149
 150 bool is_protocol_supported(
 151     struct net_state_t *net_state,
 152     int protocol);
 153
 154 bool get_next_probe_timeout(
 155     const struct net_state_t *net_state,
 156     struct timeval *timeout);
 157
 158 void send_probe(
 159     struct net_state_t *net_state,
 160     const struct probe_param_t *param);
 161
 162 void receive_replies(
 163     struct net_state_t *net_state);
 164
 165 void check_probe_timeouts(
 166     struct net_state_t *net_state);
 167
 168 void respond_to_probe(
 169     struct net_state_t *net_state,
 170     struct probe_t *probe,
 171     int icmp_type,
 172     const struct sockaddr_storage *remote_addr,
 173     unsigned int round_trip_us,
 174     int mpls_count,
 175     const struct mpls_label_t *mpls);
 176
 177 int decode_address_string(
 178     int ip_version,
 179     const char *address_string,
 180     struct sockaddr_storage *address);
 181
 182 int resolve_probe_addresses(
 183     struct net_state_t *net_state,
 184     const struct probe_param_t *param,
 185     struct sockaddr_storage *dest_sockaddr,
 186     struct sockaddr_storage *src_sockaddr);
 187
 188 struct probe_t *alloc_probe(
 189     struct net_state_t *net_state,
 190     int token);
 191
 192 void free_probe(
 193     struct net_state_t *net_state,
 194     struct probe_t *probe);
 195
 196 void platform_alloc_probe(
 197     struct net_state_t *net_state,
 198     struct probe_t *probe);
 199
 200 void platform_free_probe(
 201     struct probe_t *probe);
 202
 203 struct probe_t *find_probe(
 204     struct net_state_t *net_state,
 205     int protocol,
 206     int icmp_id,
 207     int icmp_sequence);
 208
 209 int find_source_addr(
 210     struct sockaddr_storage *srcaddr,
 211     const struct sockaddr_storage *destaddr);
 212
 213 extern char *probe_err;
 214
 215 #endif