serval-dna/mphlr.h

/* 
Serval Distributed Numbering Architecture (DNA)
Copyright (C) 2010 Paul Gardner-Stephen 

This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
*/

#include <stdio.h>
#include <errno.h>
#include <stdlib.h>
#ifdef HAVE_STRINGS_H
#include <strings.h>
#endif
#include <string.h>

#ifdef WIN32
#include "win32/win32.h"
#else
#include <unistd.h>
#ifdef HAVE_NET_IF_H
#include <net/if.h>
#endif
#ifdef HAVE_NETINET_IN_H
#include <netinet/in.h>
#endif
#ifdef HAVE_LINUX_IF_H
#include <linux/if.h>
#endif
#ifdef HAVE_LINUX_NETLINK_H
#include <linux/netlink.h>
#endif
#ifdef HAVE_LINUX_RTNETLINK_H
#include <linux/rtnetlink.h>
#endif
#ifdef HAVE_IFADDRS_H
#include <ifaddrs.h>
#endif
#endif

#if !defined(FORASTERISK) && !defined(s_addr)
#ifdef HAVE_ARPA_INET_H
#include <arpa/inet.h>
#else
typedef unsigned int in_addr_t;
struct in_addr {
   in_addr_t s_addr;
};
#endif
#endif

#ifdef HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif
#ifdef HAVE_SYS_MMAN_H
#include <sys/mman.h>
#endif
#ifdef HAVE_SYS_TIME_H
#include <sys/time.h>
#endif
#ifdef HAVE_POLL_H
#include <poll.h>
#endif
#ifdef HAVE_NETDB_H
#include <netdb.h>
#endif
#ifdef HAVE_CTYPE_H
#include <ctype.h>
#endif

#ifndef WIN32
#include <sys/ioctl.h>
#include <sys/un.h>
#include <net/if.h>
#endif

#include <fcntl.h>
//FIXME #include <getopt.h>
#include <ctype.h>

/* UDP Port numbers for various Serval services.
 The overlay mesh works over DNA */
#define PORT_DNA 4110

/* OpenWRT libc doesn't have bcopy, but has memmove */
#define bcopy(A,B,C) memmove(B,A,C)

#define BATCH 1
#define NONBATCH 0

#define REQ_SERIAL 0
#define REQ_PARALLEL -1
#define REQ_FIRSTREPLY -2
#define REQ_REPLY -101


#define SET_NOREPLACE 1
#define SET_REPLACE 2
#define SET_NOCREATE 3
#define SET_FRAGMENT 0x80

#define WITHDATA 1
#define WITHOUTDATA 0

/* Limit packet payloads to minimise packet loss of big packets in mesh networks */
#define MAX_DATA_BYTES 256

extern int debug;
extern int timeout;
extern int hlr_size;
extern unsigned char *hlr;

double simulatedBER;

extern int serverMode;

extern char *gatewayspec;

extern struct sockaddr recvaddr;
extern struct in_addr client_addr;
extern int client_port;

#define MAX_PEERS 1024
extern int peer_count;
extern struct in_addr peers[MAX_PEERS];

struct mphlr_variable {
  unsigned char id;
  char *name;
  char *desc;
};

extern char *outputtemplate;
extern char *instrumentation_file;
extern char *batman_socket;
extern char *batman_peerfile;

/* HLR records can be upto 4GB, so 4x8bits are needed to encode the size */
#define HLR_RECORD_LEN_SIZE 4

/* Packet format:

   16 bit - Magic value 0x4110
   16 bit - Version number (0001 initially)
   16 bit - Payload length
   16 bit - Cipher method (0000 = clear text)
   
   Ciphered payload follows:
   (needs to have no predictable data to protect against known plain-text attacks)
   
   64bit transaction id (random)
   8bit - payload rotation (random, to help protect encryption from cribs)

   Remainder of payload, after correcting for rotation:
   
   33byte did|subscriber id
   16byte salt
   16byte hash of PIN+salt
   
   Remainder of packet is interpretted as a series of operations

   8 bit operation: 
   00 = get, 01 = set, 02 = delete, 03 = update,
   80 = decline, 81 = okay (+optional result),
   f0 = xfer HLR record
   fe = random padding follows (to help protect cryptography from cribs)
   ff = end of transaction
   
   get - 8 bit variable value

*/
#define SID_SIZE 32 
#define DID_MAXSIZE 32
#define SIDDIDFIELD_LEN (SID_SIZE+1)
#define PINFIELD_LEN 32
#define HEADERFIELDS_LEN (2+2+2+2+8+1)
#define OFS_TRANSIDFIELD (2+2+2+2)
#define TRANSID_SIZE 8
#define OFS_ROTATIONFIELD (OFS_TRANSIDFIELD+TRANSID_SIZE)
#define OFS_SIDDIDFIELD HEADERFIELDS_LEN
#define OFS_PINFIELD (OFS_SIDDIDFIELD+SIDDIDFIELD_LEN)
#define OFS_PAYLOAD (OFS_PINFIELD+16+16)

struct response {
  int code;
  unsigned char sid[32];
  struct in_addr sender;
  unsigned char *response;
  int response_len;
  int var_id;
  int var_instance;
  int value_len;
  int value_offset;
  int value_bytes;
  struct response *next,*prev;

  /* who sent it? */
  unsigned short peer_id;
  /* have we checked it to see if it allows us to stop requesting? */
  unsigned char checked;
};

struct response_set {
  struct response *responses;
  struct response *last_response;
  int response_count;

  /* Bit mask of peers who have replied */
  unsigned char *reply_bitmask;
};

struct hlrentry_handle {
  int record_length;
  unsigned char *hlr;
  int hlr_offset;
  
  int var_id;
  int var_instance;
  unsigned char *value;
  int value_len;

  int entry_offset;
};

/* Array of variables that can be placed in an MPHLR */
#define VAR_EOR 0x00
#define VAR_CREATETIME 0x01
#define VAR_CREATOR 0x02
#define VAR_REVISION 0x03
#define VAR_REVISOR 0x04
#define VAR_PIN 0x05
#define VAR_VOICESIG 0x08
#define VAR_HLRMASTER 0x0f
#define VAR_DIDS 0x80
#define VAR_LOCATIONS 0x81
#define VAR_IEMIS 0x82
#define VAR_TEMIS 0x83
#define VAR_CALLS_IN 0x90
#define VAR_CALLS_MISSED 0x91
#define VAR_CALLS_OUT 0x92
#define VAR_SMESSAGES 0xa0
#define VAR_DID2SUBSCRIBER 0xb0
#define VAR_HLRBACKUPS 0xf0
#define VAR_NOTE 0xff
extern struct mphlr_variable vars[];

#define ACTION_GET 0x00
#define ACTION_SET 0x01
#define ACTION_DEL 0x02
#define ACTION_INSERT 0x03
#define ACTION_DIGITALTELEGRAM 0x04
#define ACTION_CREATEHLR 0x0f

#define ACTION_STATS 0x40

#define ACTION_DONE 0x7e
#define ACTION_ERROR 0x7f

#define ACTION_DECLINED 0x80
#define ACTION_OKAY 0x81
#define ACTION_DATA 0x82
#define ACTION_WROTE 0x83

#define ACTION_XFER 0xf0
#define ACTION_PAD 0xfe
#define ACTION_EOT 0xff

extern int hexdigit[16];

/* Make sure we have space to put bytes of the packet as we go along */
#define CHECK_PACKET_LEN(B) {if (((*packet_len)+(B))>=packet_maxlen) { setReason("Packet composition ran out of space."); return -1; } }

extern int sock;

int stowSid(unsigned char *packet,int ofs,char *sid);
int stowDid(unsigned char *packet,int *ofs,char *did);
int isFieldZeroP(unsigned char *packet,int start,int count);
void srandomdev();
int respondSimple(char *sid,int action,unsigned char *action_text,int action_len,
		  unsigned char *transaction_id,int cryptoFlags);
int requestItem(char *did,char *sid,char *item,int instance,unsigned char *buffer,int buffer_length,int *len,
		unsigned char *transaction_id);
int requestNewHLR(char *did,char *pin,char *sid);
int server(char *backing_file,int size,int foregroundMode);

int setReason(char *fmt, ...);
int hexvalue(unsigned char c);
int dump(char *name,unsigned char *addr,int len);
int packetOk(unsigned char *packet,int len,unsigned char *transaction_id);
int process_packet(unsigned char *packet,int len,struct sockaddr *sender,int sender_len);
int packetMakeHeader(unsigned char *packet,int packet_maxlen,int *packet_len,unsigned char *transaction_id);
int packetSetDid(unsigned char *packet,int packet_maxlen,int *packet_len,char *did);
int packetSetSid(unsigned char *packet,int packet_maxlen,int *packet_len,char *sid);
int packetFinalise(unsigned char *packet,int packet_maxlen,int *packet_len);
int packetAddHLRCreateRequest(unsigned char *packet,int packet_maxlen,int *packet_len);
int extractResponses(struct in_addr sender,unsigned char *buffer,int len,struct response_set *responses);
int packetAddVariableRequest(unsigned char *packet,int packet_maxlen,int *packet_len,
                             char *item,int instance,int start_offset,int max_offset);
int packetGetID(unsigned char *packet,int len,char *did,char *sid);
int getPeerList();
int sendToPeers(unsigned char *packet,int packet_len,int method,int peerId,struct response_set *responses);
int getReplyPackets(int method,int peer,int batchP,
		    struct response_set *responses,
		    unsigned char *transaction_id,int timeout);
int clearResponse(struct response **response);
int nextHlr(unsigned char *hlr,int *ofs);
int findHlr(unsigned char *hlr,int *ofs,char *sid,char *did);
int createHlr(char *did,char *sid);
struct hlrentry_handle *openhlrentry(unsigned char *hlr,int hofs);
struct hlrentry_handle *hlrentrygetent(struct hlrentry_handle *h);
int hlrStowValue(unsigned char *hlr,int hofs,int hlr_offset,
		 int varid,int varinstance,unsigned char *value,int len);
int hlrMakeSpace(unsigned char *hlr,int hofs,int hlr_offset,int bytes);
int packageVariableSegment(unsigned char *data,int *dlen,struct hlrentry_handle *h,
			   int offset,int buffer_size);
int packetDecipher(unsigned char *packet,int len,int cipher);
int safeZeroField(unsigned char *packet,int start,int count);
int unpackageVariableSegment(unsigned char *data,int dlen,int flags,struct response *r);
int extractSid(unsigned char *packet,int *ofs,char *sid);
int hlrSetVariable(unsigned char *hlr,int hofs,int varid,int varinstance,
		   unsigned char *value,int len);
int extractDid(unsigned char *packet,int *ofs,char *did);
char *hlrSid(unsigned char *hlr,int ofs);
int parseAssignment(unsigned char *text,int *var_id,unsigned char *value,int *value_len);
int writeItem(char *id,int var_id,int instance,unsigned char *value,int value_start,int value_len,int policy);
int packetAddVariableWrite(unsigned char *packet,int packet_maxlen,int *packet_len,
			   int itemId,int instance,unsigned char *value,int start_offset,int value_len,int flags);
int processRequest(unsigned char *packet,int len,struct sockaddr *sender,int sender_len,
		   unsigned char *transaction_id,char *did,char *sid);

int extractRequest(unsigned char *packet,int *packet_ofs,int packet_len,
		   int *itemId,int *instance,unsigned char *value,
		   int *start_offset,int *max_offset,int *flags);
int hlrGetVariable(unsigned char *hlr,int hofs,int varid,int varinstance,
		   unsigned char *value,int *len);
int packetSendRequest(int method,unsigned char *packet,int packet_len,int batchP,
		      unsigned char *transaction_id,struct response_set *responses);
int dumpResponses(struct response_set *responses);
int eraseLastResponse(struct response_set *responses);
int dropPacketP(int packet_len);
int clearResponses(struct response_set *responses);
int responseFromPeerP(struct response_set *responses,int peerId);
int responseFromPeer(struct response_set *responses,int peerId);
int additionalPeer(char *peer);
int readRoutingTable(struct in_addr peers[],int *peer_count,int peer_max);
int readBatmanPeerFile(char *file_path,struct in_addr peers[],int *peer_count,int peer_max);
int getBatmanPeerList(char *socket_path,struct in_addr peers[],int *peer_count,int peer_max);
int hlrDump(unsigned char *hlr,int hofs);
int peerAddress(char *did,char *sid,int flags);
int fixResponses(struct response_set *responses);
int importHlr(char *textfile);
int exportHlr(unsigned char *hlr,char *text);
int openHlrFile(char *backing_file,int size);
int runCommand(char *cmd);
int asteriskObtainGateway(char *requestor_sid,char *did,char *uri_out);

#define CRYPT_CIPHERED 1
#define CRYPT_SIGNED 2
#define CRYPT_PUBLIC 4

extern int overlayMode;
#define OVERLAY_INTERFACE_UNKNOWN 0
#define OVERLAY_INTERFACE_ETHERNET 1
#define OVERLAY_INTERFACE_WIFI 2
#define OVERLAY_INTERFACE_PACKETRADIO 3
typedef struct overlay_interface {
  char name[80];
  int socket;
  int bits_per_second;
  int port;
  int type;
  /* Number of milli-seconds per tick for this interface, which is basically related to the     
     the typical TX range divided by the maximum expected speed of nodes in the network.
     This means that short-range communications has a higher bandwidth requirement than
     long-range communications because the tick interval has to be shorter to still allow
     fast-convergence time to allow for mobility.

     For wifi (nominal range 100m) it is usually 500ms.
     For ~100K ISM915MHz (nominal range 1000m) it will probably be about 5000ms.
     For ~10K ISM915MHz (nominal range ~3000m) it will probably be about 15000ms.
     These figures will be refined over time, and we will allow people to set them per-interface.
  */
  int tick_ms;
  /* The time of the last tick on this interface in milli seconds */
  long long last_tick_ms;

  /* Sequence number of last tick.  Sent with announcments to help keep track of the reliability of
     getting traffic to/from us. */
  int sequence_number;

  /* Broadcast address and netmask, if known */
  struct sockaddr_in local_address;
  struct sockaddr_in broadcast_address;
  struct sockaddr_in netmask;

  /* Not necessarily the real MTU, but the largest frame size we are willing to TX on this interface.
     For radio links the actual maximum and the maximum that is likely to be delivered reliably are
     potentially two quite different values. */
  int mtu;

  /* If the interface still exists on the local machine.
     If not, it we keep track of it for a few seconds before purging it, incase of flapping, e.g.,
     due to DHCP renewal */
  int observed;
} overlay_interface;

/* Maximum interface count is rather arbitrary.
   Memory consumption is O(n) with respect to this parameter, so let's not make it too big for now.
*/
#define OVERLAY_MAX_INTERFACES 16
extern overlay_interface overlay_interfaces[OVERLAY_MAX_INTERFACES];

/*
  For each peer we need to keep track of the routes that we know to reach it.

  We want to use static sized data structures as much as we can to keep things efficient by
  allowing computed memory address lookups instead of following linked lists and other 
  non-deterministic means.

  The tricky part of doing all this is that each interface may have a different maximum number
  of peers based on the bandwidth of the link, as we do not want mesh traffic to consume all
  available bandwidth.  In particular, we need to reserve at least enough bandwidth for one
  call.

  Related to this, if we are in a mesh larger than the per-interface limit allows, then we need to
  only track the highest-scoring peers.  This sounds simple, but how to we tell when to replace a
  low-scoring peer with another one which has a better reachability score, if we are not tracking 
  the reachability score of that node?

  The answer to this is that we track as many nodes as we can, but only announce the highest
  scoring nodes on each interface as bandwidth allows.

  This also keeps our memory usage fixed.

  XXX - At present we are setting OVERLAY_MAX_PEERS at compile time.
  With a bit of work we can change this to be a run-time option.

  Memory consumption of OVERLAY_MAX_PEERS=n is O(n^2).
  XXX We could and should improve this down the track by only monitoring the top k routes, and replacing the worst route
  option when a better one comes along.  This would get the memory usage down to O(n).

 */
#define OVERLAY_MAX_PEERS 500

typedef struct overlay_peer {
  unsigned char address[SIDDIDFIELD_LEN];

  /* Scores and score update times for reaching this node via various interfaces */
  int known_routes[OVERLAY_MAX_INTERFACES];
  unsigned short scores[OVERLAY_MAX_INTERFACES][OVERLAY_MAX_PEERS];

  /* last_regeneration is the time that this peer was created/replaced with another peer.
     lastupdate[] indicates the time that another peer's reachability report
     caused us to update our score to reach via that peer.
     If lastupdate[x][y] is older than last_regeneration[y], then we must
     ignore the entry, because the lastupdate[x][y] entry references a previous
     generation of that peer, i.e., not to the peer we think it does.
     
     This slight convolution allows us to replace peers without having to touch the
     records of every other peer in our list.
  */
  int last_regeneration;
  unsigned int lastupdate[OVERLAY_MAX_INTERFACES][OVERLAY_MAX_PEERS];
} overlay_peer;

extern overlay_peer overlay_peers[OVERLAY_MAX_PEERS];

typedef struct overlay_buffer {
  unsigned char *bytes;
  int length;
  int allocSize;
  int checkpointLength;
  int sizeLimit;
} overlay_buffer;

int ob_unlimitsize(overlay_buffer *b);

typedef struct overlay_payload {
  struct overlay_payload *prev;
  struct overlay_payload *next;

  /* We allows 256 bit addresses and 32bit port numbers */
  char src[SIDDIDFIELD_LEN];
  char dst[SIDDIDFIELD_LEN];
  int srcPort;
  int dstPort;
  
  /* Hops before packet is dropped */
  unsigned char ttl;
  unsigned char trafficClass;

  unsigned char srcAddrType;
  unsigned char dstAddrType;

  /* Method of encryption if any employed */
  unsigned char cipher;

  /* Payload flags */
  unsigned char flags;

  /* Size and Pointer to the payload itself */
  int payloadLength;
  /* make the payload pointer be at the end, so that we can conveniently have the data follow this structure if necessary.
     (this lets us change the char * to a char payload[1] down the track to simplify this) */
  unsigned char *payload;

  /* time this frame was enqueued */
  long long enqueued_at;
} overlay_payload;

typedef struct overlay_txqueue {
  overlay_payload *first;
  overlay_payload *last;
  int length;
  int maxLength;
  /* Latency target in ms for this traffic class.
     Frames older than the latency target will get dropped. */
  int latencyTarget;
  
  /* XXX Need to initialise these:
     Real-time queue for voice (<200ms ?)
     Real-time queue for video (<200ms ?) (lower priority than voice)
     Ordinary service queue (<3 sec ?)
     Rhizome opportunistic queue (infinity)
     
     (Mesh management doesn't need a queue, as each overlay packet is tagged with some mesh management information)
  */
} overlay_txqueue;

extern overlay_txqueue overlay_tx[4];
#define OVERLAY_ISOCHRONOUS_VOICE 0
#define OVERLAY_ISOCHRONOUS_VIDEO 1
#define OVERLAY_ORDINARY 2
#define OVERLAY_OPPORTUNISTIC 3

int setReason(char *fmt, ...);
#define WHY(X) setReason("%s:%d:%s()  %s",__FILE__,__LINE__,__FUNCTION__,X)

overlay_buffer *ob_new(int size);
int ob_free(overlay_buffer *b);
int ob_checkpoint(overlay_buffer *b);
int ob_rewind(overlay_buffer *b);
int ob_limitsize(overlay_buffer *b,int bytes);
int ob_unlimitsize(overlay_buffer *b);
int ob_makespace(overlay_buffer *b,int bytes);
int ob_append_bytes(overlay_buffer *b,unsigned char *bytes,int count);
int ob_append_short(overlay_buffer *b,unsigned short v);
int ob_append_int(overlay_buffer *b,unsigned int v);

int op_free(overlay_payload *p);

long long parse_quantity(char *q);

int overlay_interface_init(char *name,struct sockaddr_in src_addr,struct sockaddr_in broadcast,
			   struct sockaddr_in netmask,int speed_in_bits,int port,int type);
int overlay_interface_init_socket(int i,struct sockaddr_in src_addr,struct sockaddr_in broadcast,
				  struct sockaddr_in netmask);
int overlay_interface_discover();
int overlay_interface_discover();
long long overlay_time_until_next_tick();
int overlay_rx_messages();
int overlay_check_ticks();
int overlay_add_selfannouncement();
int overlay_payload_package_fmt1(overlay_payload *p,overlay_buffer *b);

extern int overlay_interface_count;

/* Userland overlay mesh packet codes */
#define OF_SELFANNOUNCE 0x01