serval-dna/serval.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.
*/

// #define MALLOC_PARANOIA

#include <stdio.h>
#include <errno.h>
#include <stdlib.h>
#include <stdarg.h>
#ifdef HAVE_STRINGS_H
#include <strings.h>
#endif
#include <string.h>
#include <signal.h>
#include <sys/types.h>

#ifdef WIN32
#include "win32/win32.h"
#else
#include <unistd.h>
#ifdef HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif
#ifdef HAVE_NET_ROUTE_H
     #include <net/route.h>
#endif
#ifdef HAVE_LINUX_IF_H
#include <linux/if.h>
#else
#ifdef HAVE_NET_IF_H
#include <net/if.h>
#endif
#endif
#ifdef HAVE_NETINET_IN_H
#include <netinet/in.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

#ifdef HAVE_SYS_UCRED_H
#include <sys/ucred.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>
#endif

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

#ifdef ANDROID
#define DEFAULT_INSTANCE_PATH "/data/data/org.servalproject/var/serval-node"
#else
#define DEFAULT_INSTANCE_PATH "/var/serval-node"
#endif

/* bzero(3) is deprecated in favour of memset(3). */
#define bzero(addr,len) memset((addr), 0, (len))

/* 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 dnatimeout;
extern int hlr_size;
extern unsigned char *hlr;

double simulatedBER;

extern int serverMode;
extern int servalShutdown;

extern int returnMultiVars;

extern char *gatewayspec;

int rhizome_enabled();
const char *rhizome_datastore_path();

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;


typedef struct keypair {
  int type;
  unsigned char *private_key;
  int private_key_len;
  unsigned char *public_key;
  int public_key_len;
} keypair;

/* Contains just the list of private:public key pairs and types,
   the pin used to extract them, and the slot in the keyring file
   (so that it can be replaced/rewritten as required). */
#define PKR_MAX_KEYPAIRS 64
#define PKR_SALT_BYTES 32
#define PKR_MAC_BYTES 64
typedef struct keyring_identity {  
  char *PKRPin;
  unsigned int slot;
  int keypair_count;
  keypair *keypairs[PKR_MAX_KEYPAIRS];
} keyring_identity;

/* 64K identities, can easily be increased should the need arise,
   but keep it low-ish for now so that the 64K pointers don't eat too
   much ram on a small device.  Should probably think about having
   small and large device settings for some of these things */
#define KEYRING_MAX_IDENTITIES 65536
typedef struct keyring_context {
  char *KeyRingPin;
  unsigned char *KeyRingSalt;
  int KeyRingSaltLen;

  int identity_count;
  keyring_identity *identities[KEYRING_MAX_IDENTITIES];
} keyring_context;

#define KEYRING_PAGE_SIZE 4096LL
#define KEYRING_BAM_BYTES 2048LL
#define KEYRING_BAM_BITS (KEYRING_BAM_BYTES<<3)
#define KEYRING_SLAB_SIZE (KEYRING_PAGE_SIZE*KEYRING_BAM_BITS)
typedef struct keyring_bam {
  off_t file_offset;
  unsigned char bitmap[KEYRING_BAM_BYTES];
  struct keyring_bam *next;
} keyring_bam;

#define KEYRING_MAX_CONTEXTS 256
typedef struct keyring_file {
  int context_count;
  keyring_bam *bam;
  keyring_context *contexts[KEYRING_MAX_CONTEXTS];
  FILE *file;
  off_t file_size;
} keyring_file;

void keyring_free(keyring_file *k);
void keyring_free_context(keyring_context *c);
void keyring_free_identity(keyring_identity *id);
void keyring_free_keypair(keypair *kp);
int keyring_identity_mac(keyring_context *c,keyring_identity *id,
			 unsigned char *pkrsalt,unsigned char *mac);
#define KEYTYPE_CRYPTOBOX 0x01
#define KEYTYPE_CRYPTOSIGN 0x02
#define KEYTYPE_RHIZOME 0x03
/* DIDs aren't really keys, but the keyring is a real handy place to keep them,
   and keep them private if people so desire */
#define KEYTYPE_DID 0x04

/* handle to keyring file for use in running instance */
extern keyring_file *keyring;

/* Public calls to keyring management */
keyring_file *keyring_open(char *file);
keyring_file *keyring_open_with_pins(const char *pinlist);
int keyring_enter_pin(keyring_file *k, const char *pin);
int keyring_enter_pins(keyring_file *k, const char *pinlist);
int keyring_set_did(keyring_identity *id,char *did,char *name);
int keyring_sanitise_position(keyring_file *k,int *cn,int *in,int *kp);
int keyring_next_identity(keyring_file *k,int *cn,int *in,int *kp);
int keyring_find_did(keyring_file *k,int *cn,int *in,int *kp,char *did);
int keyring_find_sid(keyring_file *k,int *cn,int *in,int *kp,unsigned char *sid);
unsigned char *keyring_find_sas_private(keyring_file *k,unsigned char *sid,
					unsigned char **sas_public);
unsigned char *keyring_find_sas_public(keyring_file *k,unsigned char *sid);

int keyring_commit(keyring_file *k);
keyring_identity *keyring_create_identity(keyring_file *k,keyring_context *c,
					  char *pin);
int keyring_seed(keyring_file *k);

/* 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)

#define SID_STRLEN (SID_SIZE*2)

struct response {
  int code;
  unsigned char sid[SID_SIZE];
  struct in_addr sender;
  int recvttl;
  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;
};

/* 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_NAME 0x10
#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_RECVTTL 0xfd
#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) { return WHY("Packet composition ran out of space."); } }

extern int sock;

const char *confValueGet(const char *var, const char *defaultValue);
int confValueGetBoolean(const char *var, int defaultValue);
void confSetDebugFlags();
int confParseBoolean(const char *text, const char *option_name);

int recvwithttl(int sock,unsigned char *buffer,int bufferlen,int *ttl,
		struct sockaddr *recvaddr,unsigned int *recvaddrlen);
int validateSid(const char *sid);
int stowSid(unsigned char *packet, int ofs, const char *sid);
int stowBytes(unsigned char *packet, const char *in,int count);
int stowDid(unsigned char *packet,int *ofs,char *did);
int isFieldZeroP(unsigned char *packet,int start,int count);
void srandomdev();
int respondSimple(keyring_identity *id,
		  int action,unsigned char *action_text,int action_len,
		  unsigned char *transaction_id,int recvttl,
		  struct sockaddr *recvaddr,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 recvttl,struct sockaddr *recvaddr);
long long gettime_ms();
int server_pid();
void server_save_argv(int argc, const char *const *argv);
int server(char *backing_file);
void server_shutdown_check();
int server_create_stopfile();
int server_remove_stopfile();
int server_check_stopfile();
void serverCleanUp();
int isTransactionInCache(unsigned char *transaction_id);
void insertTransactionInCache(unsigned char *transaction_id);

int hexvalue(unsigned char c);
char *str_toupper_inplace(char *s);
int packetOk(int interface,unsigned char *packet,int len,
	     unsigned char *transaction_id, int recvttl,
	     struct sockaddr *recvaddr,int recvaddrlen,int parseP);
int process_packet(unsigned char *packet,int len,
		   int recvttl,struct sockaddr *sender,int sender_len);
int packetMakeHeader(unsigned char *packet,int packet_maxlen,int *packet_len,unsigned char *transaction_id,int cryptoflags);
int packetSetDid(unsigned char *packet,int packet_maxlen,int *packet_len,char *did);
// Deprecated
// int packetSetSid(unsigned char *packet,int packet_maxlen,int *packet_len,char *sid);
int packetSetSidFromId(unsigned char *packet,int packet_maxlen,int *packet_len,
		       keyring_identity *id);
int packetFinalise(unsigned char *packet,int packet_maxlen,int recvttl,
		   int *packet_len,int cryptoflags);
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,struct sockaddr *recvaddr,int timeout);
int clearResponse(struct response **response);
int packageVariableSegment(unsigned char *data,int *dlen,
			   struct response *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, char *sid);
int writeItem(char *sid,int var_id,int instance,unsigned char *value,
	      int value_start,int value_length,int flags, 
	      int recvttl,struct sockaddr *recvaddr);
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,int recvttl,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 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);
int packetOkDNA(unsigned char *packet,int len,unsigned char *transaction_id,
		int recvttl,struct sockaddr *recvaddr,int recvaddrlen,int parseP);
int packetOkOverlay(int interface,unsigned char *packet,int len,
		    unsigned char *transaction_id,int recvttl,
		    struct sockaddr *recvaddr,int recvaddrlen,int parseP);
int prepareGateway(char *gatewayspec);
int packetSendRequest(int method,unsigned char *packet,int packet_len,int batchP,
		      unsigned char *transaction_id,struct sockaddr *recvaddr,
		      struct response_set *responses);
int readArpTable(struct in_addr peers[],int *peer_count,int peer_max);

#define OVERLAY_MAX_INTERFACES 16

typedef struct overlay_address_table {
  unsigned char epoch;
  char sids[256][SID_SIZE];
  /* 0x00 = not set, which thus limits us to using only 255 (0x01-0xff) of the indexes for
     storing addresses.
     By spending an extra 256 bytes we reduce, but not eliminate the problem of collisions.
     Will think about a complete solution later.
  */
  unsigned char byfirstbyte[256][2];
  /* next free entry in sid[] */
  unsigned char next_free;
} overlay_address_table;

typedef struct sid {
  unsigned char b[SID_SIZE];
} sid;

typedef struct overlay_address_cache {
  int size;
  int shift; /* Used to calculat lookup function, which is (b[0].b[1].b[2]>>shift) */
  sid *sids; /* one entry per bucket, to keep things simple. */
  /* XXX Should have a means of changing the hash function so that naughty people can't try
     to force our cache to flush with duplicate addresses? 
     But we must use only the first 24 bits of the address due to abbreviation policies, 
     so our options are limited.
     For now the hash will be the first k bits.
  */
} overlay_address_cache;

extern sid overlay_abbreviate_current_sender;

typedef struct overlay_frame {
  struct overlay_frame *prev;
  struct overlay_frame *next;

  unsigned int type;
  unsigned int modifiers;

  unsigned char ttl;
  unsigned char dequeue;

  /* Mark which interfaces the frame has been sent on,
     so that we can ensure that broadcast frames get sent
     exactly once on each interface */
  int isBroadcast;
  unsigned char broadcast_sent_via[OVERLAY_MAX_INTERFACES];

  unsigned char nexthop[32];
  int nexthop_address_status;
  int nexthop_interface; /* which interface the next hop should be attempted on */

  unsigned char destination[32];
  int destination_address_status;

  unsigned char source[32];
  int source_address_status;

  /* IPv4 node frame was received from (if applicable) */
  struct sockaddr *recvaddr;

  /* Frame content from destination address onwards */
  int bytecount;
  unsigned char *bytes;

  /* Actual payload */
  struct overlay_buffer *payload;

  int rfs; /* remainder of frame size */
  
  long long enqueued_at;

} overlay_frame;

int overlay_frame_process(int interface,overlay_frame *f);
int overlay_frame_resolve_addresses(int interface,overlay_frame *f);


#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 fd;
  int offset;
  int fileP;
  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; /* milliseconds per tick */

  /* The time of the last tick on this interface in milli seconds */
  long long last_tick_ms;
  /* How many times have we abbreviated our address since we last announced it in full? */
  int ticks_since_sent_full_address;

  /* sequence number of last packet sent on this interface.
     Used to allow NACKs that can request retransmission of recent packets.
  */
  int sequence_number;
  /* XXX need recent packet buffers to support the above */

  /* Broadcast address and netmask, if known */
  /* We really only case about distinct broadcast addresses on interfaces.
     Also simplifies aliases on interfaces.
     struct sockaddr_in local_address; */
  struct sockaddr_in broadcast_address;

  /* 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.
*/
extern overlay_interface overlay_interfaces[OVERLAY_MAX_INTERFACES];
extern int overlay_last_interface_number; // used to remember where a packet came from
extern unsigned int overlay_sequence_number;

/* Has someone sent us an abbreviation of an unknown type recently? If so remind them
   that we don't accept these.
   XXX - This method assumes bidirectional links.  We should consider sending direct
   to the perpetuator. We will deal with that in time, the main thing is that we have
   a message type that can be used for the purpose.
*/
extern int overlay_interface_repeat_abbreviation_policy[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;
  int var_length_offset;
  int var_length_bytes;
} overlay_buffer;

int ob_unlimitsize(overlay_buffer *b);


typedef struct overlay_txqueue {
  struct overlay_frame *first;
  struct overlay_frame *last;
  int length; /* # frames in queue */
  int maxLength; /* max # frames in queue before we consider ourselves congested */

  /* 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;


#define OQ_ISOCHRONOUS_VOICE 0
#define OQ_MESH_MANAGEMENT 1
#define OQ_ISOCHRONOUS_VIDEO 2
#define OQ_ORDINARY 3
#define OQ_OPPORTUNISTIC 4
#define OQ_MAX 5
extern overlay_txqueue overlay_tx[OQ_MAX];

#define LOG_LEVEL_DEBUG     (0)
#define LOG_LEVEL_INFO      (1)
#define LOG_LEVEL_WARN      (2)
#define LOG_LEVEL_ERROR     (3)
#define LOG_LEVEL_FATAL     (4)

void logMessage(int level, const char *file, unsigned int line, const char *function, const char *fmt, ...);
void vlogMessage(int level, const char *file, unsigned int line, const char *function, const char *fmt, va_list);
long long debugFlagMask(const char *flagname);
char *catv(const char *data, char *buf, size_t len);
int dump(char *name,unsigned char *addr,int len);

const char *trimbuildpath(const char *s);

#define LOGF(L,F,...)       logMessage(L, __FILE__, __LINE__, __FUNCTION__, F, ##__VA_ARGS__)

#define FATALF(F,...)       do { logMessage(LOG_LEVEL_FATAL, __FILE__, __LINE__, __FUNCTION__, F, ##__VA_ARGS__); exit(-1); } while (1)
#define FATAL(X)            FATALF("%s", (X))
#define FATAL_perror(X)     FATALF("%s: %s [errno=%d]", (X), strerror(errno), errno)

#define WHYF(F,...)         (LOGF(LOG_LEVEL_ERROR, F, ##__VA_ARGS__), -1)
#define WHY(X)              WHYF("%s", (X))
#define WHYNULL(X)          (LOGF(LOG_LEVEL_ERROR, "%s", X), NULL)
#define WHY_perror(X)       WHYF("%s: %s [errno=%d]", (X), strerror(errno), errno)

#define WARNF(F,...)        logMessage(LOG_LEVEL_WARN, __FILE__, __LINE__, __FUNCTION__, F, ##__VA_ARGS__)
#define WARN(X)             WARNF("%s", (X))
#define WARN_perror(X)      WARNF("%s: %s [errno=%d]", (X), strerror(errno), errno)

#define INFOF(F,...)        logMessage(LOG_LEVEL_INFO, __FILE__, __LINE__, __FUNCTION__, F, ##__VA_ARGS__)
#define INFO(X)             INFOF("%s", (X))

#define DEBUGF(F,...)       logMessage(LOG_LEVEL_DEBUG, __FILE__, __LINE__, __FUNCTION__, F, ##__VA_ARGS__)
#define DEBUG(X)            DEBUGF("%s", (X))
#define DEBUG_perror(X)     DEBUGF("%s: %s [errno=%d]", (X), strerror(errno), errno)
#define D DEBUG("D")

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_byte(overlay_buffer *b,unsigned char byte);
int ob_append_bytes(overlay_buffer *b,unsigned char *bytes,int count);
unsigned char *ob_append_space(overlay_buffer *b,int count);
int ob_append_short(overlay_buffer *b,unsigned short v);
int ob_append_int(overlay_buffer *b,unsigned int v);
int ob_patch_rfs(overlay_buffer *b,int l);
int ob_indel_space(overlay_buffer *b,int offset,int shift);
int ob_append_rfs(overlay_buffer *b,int l);

int op_free(overlay_frame *p);
overlay_frame *op_dup(overlay_frame *f);

long long parse_quantity(char *q);

int overlay_interface_init(char *name,struct sockaddr_in src_addr,struct sockaddr_in broadcast,
			   int speed_in_bits,int port,int type);
int overlay_interface_init_socket(int i,struct sockaddr_in src_addr,struct sockaddr_in broadcast);
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_frame_package_fmt1(overlay_frame *p,overlay_buffer *b);
int overlay_interface_args(const char *arg);
int overlay_get_nexthop(unsigned char *d,unsigned char *nexthop,int *nexthoplen,
			int *interface);
int overlay_sendto(struct sockaddr_in *recipientaddr,unsigned char *bytes,int len);
int overlay_rhizome_add_advertisements(int interface_number,overlay_buffer *e);
int overlay_add_local_identity(unsigned char *s);
int overlay_address_is_local(unsigned char *s);

extern int overlay_interface_count;

#define OVERLAY_MAX_LOCAL_IDENTITIES 256
extern int overlay_local_identity_count;
extern unsigned char *overlay_local_identities[OVERLAY_MAX_LOCAL_IDENTITIES];

/* Overlay mesh packet codes */
#define OF_TYPE_BITS 0xf0
#define OF_TYPE_SELFANNOUNCE 0x10 /* BATMAN style announcement frames */
#define OF_TYPE_SELFANNOUNCE_ACK 0x20 /* BATMAN style "I saw your announcment" frames */
#define OF_TYPE_DATA 0x30 /* Ordinary data frame.
		        Upto MTU bytes of payload.
			32 bit channel/port indicator for each end. 
		        */
#define OF_TYPE_DATA_VOICE 0x40 /* Voice data frame. 
			      Limited to 255 bytes of payload. 
			      1 byte channel/port indicator for each end */
#define OF_TYPE_RHIZOME_ADVERT 0x50 /* Advertisment of file availability via Rhizome */
#define OF_TYPE_PLEASEEXPLAIN 0x60 /* Request for resolution of an abbreviated address */
#define OF_TYPE_NODEANNOUNCE 0x70
#define OF_TYPE_IDENTITYENQUIRY 0x80
#define OF_TYPE_RESERVED_09 0x90
#define OF_TYPE_RESERVED_0a 0xa0
#define OF_TYPE_RESERVED_0b 0xb0
#define OF_TYPE_RESERVED_0c 0xc0
#define OF_TYPE_RESERVED_0d 0xd0
#define OF_TYPE_EXTENDED12 0xe0 /* modifier bits and next byte provide 12 bits extended format
				   (for future expansion, just allows us to skip the frame) */
#define OF_TYPE_EXTENDED20 0xf0 /* modifier bits and next 2 bytes provide 20 bits extended format
				 (for future expansion, just allows us to skip the frame) */
/* Flags used to control the interpretation of the resolved type field */
#define OF_TYPE_FLAG_BITS 0xf0000000
#define OF_TYPE_FLAG_NORMAL 0x0
#define OF_TYPE_FLAG_E12 0x10000000
#define OF_TYPE_FLAG_E20 0x20000000

/* Modifiers that indicate the disposition of the frame */
#define OF_MODIFIER_BITS 0x0f

/* Crypto/security options */
#define OF_CRYPTO_BITS 0x0c
#define OF_CRYPTO_NONE 0x00
#define OF_CRYPTO_CIPHERED 0x04 /* Encrypted frame */
#define OF_CRYPTO_SIGNED 0x08   /* signed frame */
/* The following was previously considered, but is not being implemented at this
   time.
   #define OF_CRYPTO_PARANOID 0x0c Encrypted and digitally signed frame, with final destination address also encrypted. */

/* Data compression */
#define OF_COMPRESS_BITS 0x03
#define OF_COMPRESS_NONE 0x00
#define OF_COMPRESS_GZIP 0x01     /* Frame compressed with gzip */
#define OF_COMPRESS_BZIP2 0x02    /* bzip2 */
#define OF_COMPRESS_RESERVED 0x03 /* Reserved for another compression system */

#define OVERLAY_ADDRESS_CACHE_SIZE 1024
int overlay_abbreviate_address(unsigned char *in,unsigned char *out,int *ofs);
int overlay_abbreviate_append_address(overlay_buffer *b,unsigned char *a);

int overlay_abbreviate_expand_address(int interface,unsigned char *in,int *inofs,unsigned char *out,int *ofs);
int overlay_abbreviate_cache_address(unsigned char *sid);
int overlay_abbreviate_cache_lookup(unsigned char *in,unsigned char *out,int *ofs,
				    int prefix_bytes,int index_bytes);
int overlay_abbreviate_remember_index(int index_byte_count,unsigned char *in,unsigned char *index_bytes);
extern int overlay_abbreviate_repeat_policy;
int overlay_abbreviate_set_most_recent_address(unsigned char *in);
int overlay_abbreviate_clear_most_recent_address();

/* Return codes for resolution of abbreviated addressses */
#define OA_UNINITIALISED 0 /* Nothing has been written into the field */
#define OA_RESOLVED 1      /* We expanded the abbreviation successfully */
#define OA_PLEASEEXPLAIN 2 /* We need the sender to explain their abbreviation */
#define OA_UNSUPPORTED 3   /* We cannot expand the abbreviation as we do not understand this code */

/* Codes used to describe abbreviated addresses.
   Values 0x10 - 0xff are the first byte of, and implicit indicators of addresses written in full */
#define OA_CODE_SELF 0x00
#define OA_CODE_INDEX 0x01
#define OA_CODE_02 0x02
#define OA_CODE_PREVIOUS 0x03
#define OA_CODE_04 0x04
#define OA_CODE_PREFIX3 0x05
#define OA_CODE_PREFIX7 0x06
#define OA_CODE_PREFIX11 0x07
#define OA_CODE_FULL_INDEX1 0x08
#define OA_CODE_PREFIX3_INDEX1 0x09
#define OA_CODE_PREFIX7_INDEX1 0x0a
#define OA_CODE_PREFIX11_INDEX1 0x0b
#define OA_CODE_0C 0x0c
#define OA_CODE_PREFIX11_INDEX2 0x0d
#define OA_CODE_FULL_INDEX2 0x0e
/* The TTL field in a frame is used to differentiate between link-local and wide-area broadcasts */
#define OA_CODE_BROADCAST 0x0f

#define RFS_PLUS250 0xfa
#define RFS_PLUS456 0xfb
#define RFS_PLUS762 0xfc
#define RFS_PLUS1018 0xfd
#define RFS_PLUS1274 0xfe
#define RFS_3BYTE 0xff
int rfs_length(int l);
int rfs_encode(int l,unsigned char *b);
int rfs_decode(unsigned char *b,int *offset);

typedef struct overlay_neighbour_observation {
  /* Sequence numbers are handled as ranges because the tick
     rate can vary between interfaces, and we want to be able to
     estimate the reliability of links to nodes that may have
     several available interfaces.
     We don't want sequence numbers to wrap too often, but we
     would also like to support fairly fast ticking interfaces,
     e.g., for gigabit type links. So lets go with 1ms granularity. */
  unsigned int s1;
  unsigned int s2;
  long long time_ms;
  unsigned char sender_interface;
  unsigned char valid;
} overlay_neighbour_observation;

#define OVERLAY_SENDER_PREFIX_LENGTH 12
typedef struct overlay_node_observation {
  unsigned char observed_score; /* serves as validty check also */
  unsigned char corrected_score;
  unsigned char gateways_en_route;
  unsigned char RESERVED; /* for alignment */
  unsigned char interface;
  long long rx_time;
  unsigned char sender_prefix[OVERLAY_SENDER_PREFIX_LENGTH];
} overlay_node_observation;

/* Keep track of last 32 observations of a node.
   Hopefully this is enough, if not, we will increase.
   To keep the requirement down we will collate contigious neighbour observations on each interface.
   For node observations we can just replace old observations with new ones. 
*/
#define OVERLAY_MAX_OBSERVATIONS 32

typedef struct overlay_node {
  unsigned char sid[SID_SIZE];
  int neighbour_id; /* 0=not a neighbour */
  int most_recent_observation_id;
  int best_link_score;
  int best_observation;
  unsigned int last_first_hand_observation_time_millisec;
  long long last_observation_time_ms;
  /* When did we last advertise this node on each interface, and what score
     did we advertise? */
  long long most_recent_advertisment[OVERLAY_MAX_INTERFACES];
  unsigned char most_recent_advertised_score[OVERLAY_MAX_INTERFACES];
  overlay_node_observation observations[OVERLAY_MAX_OBSERVATIONS];
} overlay_node;

typedef struct overlay_neighbour {
  long long last_observation_time_ms;
  long long last_metric_update;
  int most_recent_observation_id;
  overlay_neighbour_observation observations[OVERLAY_MAX_OBSERVATIONS];
  overlay_node *node;

  /* Scores of visibility from each of the neighbours interfaces.
     This is so that the sender knows which interface to use to reach us.
   */
  unsigned char scores[OVERLAY_MAX_INTERFACES];

  /* One-byte index entries for address abbreviation */
  unsigned char one_byte_index_address_prefixes[256][OVERLAY_SENDER_PREFIX_LENGTH];
} overlay_neighbour;
extern overlay_neighbour *overlay_neighbours;

long long overlay_gettime_ms();
int overlay_route_init(int mb_ram);
int overlay_route_saw_selfannounce_ack(int interface,overlay_frame *f,long long now);
int overlay_route_recalc_node_metrics(overlay_node *n,long long now);
int overlay_route_recalc_neighbour_metrics(overlay_neighbour *n,long long now);
int overlay_route_saw_selfannounce(int interface,overlay_frame *f,long long now);
overlay_node *overlay_route_find_node(unsigned char *sid,int prefixLen,int createP);
unsigned int overlay_route_hash_sid(unsigned char *sid);
int overlay_route_init(int mb_ram);
overlay_neighbour *overlay_route_get_neighbour_structure(unsigned char *packed_sid, 
							 int prefixLen,int createP);
unsigned char *overlay_get_my_sid();
int overlay_frame_set_me_as_source(overlay_frame *f);
int overlay_frame_set_neighbour_as_source(overlay_frame *f,overlay_neighbour *n);
int overlay_frame_set_neighbour_as_destination(overlay_frame *f,overlay_neighbour *n);
int overlay_frame_set_broadcast_as_destination(overlay_frame *f);
int overlay_broadcast_generate_address(unsigned char *a);
int overlay_update_sequence_number();
int packetEncipher(unsigned char *packet,int maxlen,int *len,int cryptoflags);
int overlayServerMode();
int overlay_payload_enqueue(int q,overlay_frame *p,int forceBroadcastP);
long long overlay_time_in_ms();
int overlay_abbreviate_lookup_sender_id();
int ob_dump(overlay_buffer *b,char *desc);
unsigned int ob_get_int(overlay_buffer *b,int offset);
char *overlay_render_sid(unsigned char *sid);
int overlay_route_record_link(long long now,unsigned char *to,
			      unsigned char *via,int sender_interface,
			      unsigned int s1,unsigned int s2,int score,int gateways_en_route);
int overlay_route_dump();
int overlay_route_tick();
int overlay_route_tick_neighbour(int neighbour_id,long long now);
int overlay_route_tick_node(int bin,int slot,long long now);
int overlay_route_add_advertisements(int interface,overlay_buffer *e);
int ovleray_route_please_advertise(overlay_node *n);
int overlay_abbreviate_set_current_sender(unsigned char *in);

extern int overlay_bin_count;
extern int overlay_bin_size; /* associativity, i.e., entries per bin */
extern int overlay_bin_bytes;
extern overlay_node **overlay_nodes;

int overlay_route_saw_advertisements(int i,overlay_frame *f, long long now);
int overlay_rhizome_saw_advertisements(int i,overlay_frame *f, long long now);
int overlay_route_please_advertise(overlay_node *n);
int rhizome_server_get_fds(struct pollfd *fds,int *fdcount,int fdmax);
int rhizome_server_poll();
int rhizome_saw_voice_traffic();
int overlay_saw_mdp_containing_frame(int interface,overlay_frame *f,long long now);

#include "nacl.h"

#define DEBUG_PACKETRX              (1 << 0)
#define DEBUG_OVERLAYINTERFACES     (1 << 1)
#define DEBUG_VERBOSE               (1 << 2)
#define DEBUG_VERBOSE_IO            (1 << 3)
#define DEBUG_PEERS                 (1 << 4)
#define DEBUG_DNARESPONSES          (1 << 5)
#define DEBUG_DNAREQUESTS           (1 << 6)
#define DEBUG_SIMULATION            (1 << 7)
#define DEBUG_DNAVARS               (1 << 8)
#define DEBUG_PACKETFORMATS         (1 << 9)
#define DEBUG_GATEWAY               (1 << 10)
#define DEBUG_HLR                   (1 << 11)
#define DEBUG_IO                    (1 << 12)
#define DEBUG_OVERLAYFRAMES         (1 << 13)
#define DEBUG_OVERLAYABBREVIATIONS  (1 << 14)
#define DEBUG_OVERLAYROUTING        (1 << 15)
#define DEBUG_SECURITY              (1 << 16)
#define DEBUG_RHIZOME               (1 << 17)
#define DEBUG_OVERLAYROUTEMONITOR   (1 << 18)
#define DEBUG_QUEUES                (1 << 19)
#define DEBUG_BROADCASTS            (1 << 20)
#define DEBUG_RHIZOMESYNC           (1 << 21)
#define DEBUG_PACKETTX              (1 << 22)
#define DEBUG_PACKETCONSTRUCTION    (1 << 23)
#define DEBUG_MANIFESTS             (1 << 24)

int serval_packetvisualise(FILE *f,char *message,unsigned char *packet,int plen);

int overlay_broadcast_drop_check(unsigned char *a);
int overlay_address_is_broadcast(unsigned char *a);
int overlay_broadcast_generate_address(unsigned char *a);
int overlay_abbreviate_unset_current_sender();
int rhizome_fetching_get_fds(struct pollfd *fds,int *fdcount,int fdmax);
int rhizome_fetch_poll();
int rhizome_opendb();

typedef struct dna_identity_status {
  char sid[SID_STRLEN];
  char did[64+1];
  char name[255+1];

  int initialisedP;
  time_t startofvalidity;
  time_t endofvalidity;
  int verifier_count;
#define MAX_SIGNATURES 16
  /* Dynamically allocate these so that we don't waste a memory
     (well, if we are talking about running on a feature phone, 4KB per entry
     (16*256 bytes) is best avoided if we can.) */
  unsigned char *verifiers[MAX_SIGNATURES];
#define IDENTITY_VERIFIED (1<<0)
#define IDENTITY_VERIFIEDBYME (1<<1)
#define IDENTITY_NOTVERIFIED (1<<2)
  /* The value below is for caching negative results */
#define IDENTITY_UNKNOWN (1<<3)
  int verificationStatus;

  /* Set if we know that there are no duplicates of this DID/name
     combination, as it allows us to avoid a database lookup. */
  int uniqueDidAndName;
} dna_identity_status;

int parseCommandLine(int argc, const char *const *argv);

int parseOldCommandLine(int argc, char **argv);
int parseAssignment(unsigned char *text, int *var_id, unsigned char *value, int *value_len);

dna_identity_status *dnacache_lookup(char *did,char *name,char *sid);
dna_identity_status *dnacache_lookup_next();
int dnacache_update_verification(char *did,char *sid,char *name,
				 char *signature,int revokeVerificationP);
int dnacache_vouch_for_identity(char *did,char *sid,char *name);

#undef DEBUG_MEM_ABUSE
#ifdef DEBUG_MEM_ABUSE
int memabuseInit();
int _memabuseCheck(const char *func,const char *file,const int line);
#define memabuseCheck() _memabuseCheck(__FUNCTION__,__FILE__,__LINE__)
#else
#define memabuseInit() /* */
#define memabuseCheck() /* */
#endif

const char *thisinstancepath;
const char *serval_instancepath();
int form_serval_instance_path(char * buf, size_t bufsiz, const char *path);
int create_serval_instance_dir();

int mkdirs(const char *path, mode_t mode);
int mkdirsn(const char *path, size_t len, mode_t mode);

/* Handy statement for forming a path to an instance file in a char buffer whose declaration
 * is in scope (so that sizeof(buf) will work).  Evaluates to true if the pathname fitted into
 * the provided buffer, false (0) otherwise (after printing a message to stderr).  */
#define FORM_SERVAL_INSTANCE_PATH(buf, path) (form_serval_instance_path(buf, sizeof(buf), (path)))

int overlay_mdp_get_fds(struct pollfd *fds,int *fdcount,int fdmax);
int overlay_mdp_poll();
int overlay_mdp_reply_error(int sock,
			    struct sockaddr_un *recvaddr,int recvaddrlen,
			    int error_number,char *message);
extern int mdp_abstract_socket;
extern int mdp_named_socket;


typedef struct sockaddr_mdp {
  unsigned char sid[SID_SIZE];
  unsigned int port;
} sockaddr_mdp;
unsigned char *keyring_get_nm_bytes(sockaddr_mdp *priv,sockaddr_mdp *pub);

#define MDP_PORT_ECHO 0x00000007
#define MDP_PORT_KEYMAPREQUEST 0x10000001
#define MDP_PORT_VOMP 0x10000002
#define MDP_PORT_DNALOOKUP 0x10000003

#define MDP_TYPE_MASK 0xff
#define MDP_FLAG_MASK 0xff00
#define MDP_FORCE 0x0100
#define MDP_NOCRYPT 0x0200
#define MDP_NOSIGN 0x0400
#define MDP_TX 1
typedef struct overlay_mdp_data_frame {
  sockaddr_mdp src;
  sockaddr_mdp dst;
  unsigned short payload_length;
#define MDP_MTU 2000
  unsigned char payload[MDP_MTU-100];
} overlay_mdp_data_frame;

#define MDP_BIND 3
typedef struct overlay_mdp_bind_request {
  unsigned int port_number;
  unsigned char sid[SID_SIZE];
} overlay_mdp_bind_request;

#define MDP_ERROR 4
typedef struct overlay_mdp_error {
  unsigned int error;
  char message[128];
} overlay_mdp_error;

#define MDP_GETADDRS 5
#define MDP_ADDRLIST 6
typedef struct overlay_mdp_addrlist {
  int selfP;
  unsigned int server_sid_count;
  unsigned int first_sid;
  unsigned int last_sid;
  unsigned int frame_sid_count; /* how many of the following 59 slots are
				    populated */
  /* 59*32 < (MDP_MTU-100), so up to 59 SIDs in a single reply.
     Multiple replies can be used to respond with more. */
#define MDP_MAX_SID_REQUEST 59
  unsigned char sids[MDP_MAX_SID_REQUEST][SID_SIZE];
} overlay_mdp_addrlist;

#define MDP_VOMPEVENT 7
#define VOMP_MAX_CALLS 16
/* Maximum amount of audio to cram into a VoMP audio packet.
   More lets us include preemptive retransmissions.
   Less reduces the chance of packets getting lost, and reduces
   the bandwidth used. */
#define VOMP_STUFF_BYTES 800
/* elements sorted by size for alignment */
typedef struct overlay_mdp_vompevent {
  /* Once a call has been established, this is how the MDP/VoMP server
     and user-end process talk about the call. */
  unsigned int call_session_token;
  unsigned long long audio_sample_endtime;
  unsigned long long audio_sample_starttime;
  unsigned long long last_activity;
#define VOMPEVENT_RINGING (1<<0)
#define VOMPEVENT_CALLENDED (1<<1)
#define VOMPEVENT_CALLREJECT (1<<2)
#define VOMPEVENT_HANGUP VOMPEVENT_CALLREJECT
#define VOMPEVENT_TIMEOUT (1<<3)
#define VOMPEVENT_ERROR (1<<4)
#define VOMPEVENT_AUDIOSTREAMING (1<<5)
#define VOMPEVENT_DIAL (1<<6)
#define VOMPEVENT_REGISTERINTEREST (1<<7)
#define VOMPEVENT_WITHDRAWINTEREST (1<<8)
#define VOMPEVENT_CALLCREATED (1<<9)
#define VOMPEVENT_PICKUP (1<<10)
#define VOMPEVENT_CALLINFO (1<<11)
#define VOMPEVENT_AUDIOPACKET (1<<12)
  unsigned int flags;
  unsigned short audio_sample_bytes;
  unsigned char audio_sample_codec;  
  unsigned char local_state;
  unsigned char remote_state;
  /* list of codecs the registering party is willing to support
       (for VOMPEVENT_REGISTERINTEREST) */
  unsigned char supported_codecs[257];
  union {
    struct {
      /* Used to precisely define the call end points during call
	 setup. */
      char local_did[64];
      char remote_did[64];
      unsigned char local_sid[SID_SIZE];
      unsigned char remote_sid[SID_SIZE];
      /* session numbers of other calls in progress 
	 (for VOMPEVENT_CALLINFO) */
      unsigned int other_calls_sessions[VOMP_MAX_CALLS];
      unsigned char other_calls_states[VOMP_MAX_CALLS];
    };
#define MAX_AUDIO_BYTES 1024
    unsigned char audio_bytes[MAX_AUDIO_BYTES];
  };
} overlay_mdp_vompevent;

#define MDP_NODEINFO 8
typedef struct overlay_mdp_nodeinfo {
  unsigned char sid[SID_SIZE];
  int sid_prefix_length; /* allow wildcard matching */
  char did[64];
  char name[64];
  int foundP;
  int localP;
  int neighbourP;
  int score;
  int interface_number;
  int resolve_did;
  unsigned long long time_since_last_observation;
  int index; /* which record to return or was returned (incase there are multiple matches) */
  int count; /* number of matching records */
} overlay_mdp_nodeinfo;

#define MDP_GOODBYE 9
typedef struct overlay_mdp_frame {
#define MDP_AWAITREPLY 9999
  unsigned int packetTypeAndFlags;
  union {
    overlay_mdp_data_frame out;
    overlay_mdp_data_frame in;
    overlay_mdp_bind_request bind;
    overlay_mdp_addrlist addrlist;
    overlay_mdp_vompevent vompevent;
    overlay_mdp_nodeinfo nodeinfo;
    overlay_mdp_error error;
    /* 2048 is too large (causes EMSGSIZE errors on OSX, but probably fine on
       Linux) */
    char raw[MDP_MTU];
  };
} overlay_mdp_frame;

int keyring_mapping_request(keyring_file *k,overlay_mdp_frame *req);

/* Client-side MDP function */
extern int mdp_client_socket;
int overlay_mdp_client_init();
int overlay_mdp_client_done();
int overlay_mdp_client_poll(long long timeout_ms);
int overlay_mdp_recv(overlay_mdp_frame *mdp,int *ttl);
int overlay_mdp_send(overlay_mdp_frame *mdp,int flags,int timeout_ms);

/* Server-side MDP functions */
int overlay_saw_mdp_frame(int interface, overlay_mdp_frame *mdp,long long now);
int overlay_mdp_swap_src_dst(overlay_mdp_frame *mdp);
int overlay_mdp_reply(int sock,struct sockaddr_un *recvaddr,int recvaddrlen,
			  overlay_mdp_frame *mdpreply);
int overlay_mdp_relevant_bytes(overlay_mdp_frame *mdp);
int overlay_mdp_dispatch(overlay_mdp_frame *mdp,int userGeneratedFrameP,
		     struct sockaddr_un *recvaddr,int recvaddlen);

int ob_bcopy(overlay_buffer *b,int from, int to, int len);
int ob_setbyte(overlay_buffer *b,int ofs,unsigned char value);

char *overlay_render_sid(unsigned char *sid);
char *overlay_render_sid_prefix(unsigned char *sid,int l);
int dump_payload(overlay_frame *p,char *message);

int urandombytes(unsigned char *x,unsigned long long xlen);

#ifdef MALLOC_PARANOIA
#define malloc(X) _serval_debug_malloc(X,__FILE__,__FUNCTION__,__LINE__)
#define calloc(X,Y) _serval_debug_calloc(X,Y,__FILE__,__FUNCTION__,__LINE__)
#define free(X) _serval_debug_free(X,__FILE__,__FUNCTION__,__LINE__)

void *_serval_debug_malloc(unsigned int bytes,char *file,const char *func,int line);
void *_serval_debug_calloc(unsigned int bytes,unsigned int count,char *file,const char *func,int line);
void _serval_debug_free(void *p,char *file,const char *func,int line);
#endif


typedef struct vomp_call_half {
  unsigned char sid[SID_SIZE];
  unsigned char did[64];
  unsigned char state;
  unsigned char last_state; // last state communicated to monitoring parties
  unsigned char codec;
  unsigned int session;
#define VOMP_SESSION_MASK 0xffffff
  unsigned int sequence;
  /* the following is from call creation, not start of audio flow */
  unsigned long long milliseconds_since_call_start;
} vomp_call_half;

typedef struct vomp_sample_block {
  unsigned int codec;
  unsigned long long starttime;
  unsigned long long endtime;
  unsigned char bytes[1024];
} vomp_sample_block;

#define VOMP_MAX_RECENT_SAMPLES 8
typedef struct vomp_call_state {
  vomp_call_half local;
  vomp_call_half remote;
  int ringing;
  int fast_audio;
  unsigned long long create_time;
  unsigned long long last_activity;
  unsigned long long audio_clock;
  long long  next_status_time;
  int audio_started;
  int last_sent_status;
  unsigned char remote_codec_list[256];
  int recent_sample_rotor;
  vomp_sample_block recent_samples[VOMP_MAX_RECENT_SAMPLES];
} vomp_call_state;

extern int vomp_call_count;
extern int vomp_active_call;
extern vomp_call_state vomp_call_states[VOMP_MAX_CALLS];


#define VOMP_CODEC_NONE 0x00
#define VOMP_CODEC_CODEC2_2400 0x01
#define VOMP_CODEC_CODEC2_1400 0x02
#define VOMP_CODEC_GSMHALF 0x03
#define VOMP_CODEC_GSMFULL 0x04
#define VOMP_CODEC_16SIGNED 0x05
#define VOMP_CODEC_8ULAW 0x06
#define VOMP_CODEC_8ALAW 0x07
#define VOMP_CODEC_PCM 0x08
#define VOMP_CODEC_DTMF 0x80
#define VOMP_CODEC_ENGAGED 0x81
#define VOMP_CODEC_ONHOLD 0x82
#define VOMP_CODEC_CALLERID 0x83
#define VOMP_CODEC_CODECSISUPPORT 0xfe
#define VOMP_CODEC_CHANGEYOURCODECTO 0xff

#define VOMP_STATE_NOCALL 1
#define VOMP_STATE_CALLPREP 2
#define VOMP_STATE_RINGINGOUT 3
#define VOMP_STATE_RINGINGIN 4
#define VOMP_STATE_INCALL 5
#define VOMP_STATE_CALLENDED 6

/* in milliseconds of inactivity */
#define VOMP_CALL_TIMEOUT 120000
#define VOMP_CALL_STATUS_INTERVAL 1000

#define VOMP_TELLINTERESTED (1<<0)
#define VOMP_TELLREMOTE (1<<1)
#define VOMP_NEWCALL (1<<2)
#define VOMP_FORCETELLREMOTE ((1<<3)|VOMP_TELLREMOTE)
#define VOMP_TELLCODECS (1<<4)
#define VOMP_SENDAUDIO (1<<5)

vomp_call_state *vomp_find_call_by_session(int session_token);
int vomp_mdp_event(overlay_mdp_frame *mdp,
		   struct sockaddr_un *recvaddr,int recvaddrlen);
int vomp_mdp_received(overlay_mdp_frame *mdp);
char *vomp_describe_state(int state);
char *vomp_describe_codec(int c);
int vomp_tick();
int vomp_tick_interval();
int vomp_sample_size(int c);
int vomp_codec_timespan(int c);
int vomp_send_status(vomp_call_state *call,int flags,overlay_mdp_frame *arg);
int vomp_parse_dtmf_digit(char c);

typedef struct command_line_option {
  int (*function)(int argc, const char *const *argv, struct command_line_option *o);
  const char *words[32]; // 32 words should be plenty!
  unsigned long long flags;
#define CLIFLAG_NONOVERLAY (1<<0) /* Uses a legacy IPv4 DNA call instead of overlay mnetwork */
#define CLIFLAG_STANDALONE (1<<1) /* Cannot be issued to a running instance */
  const char *description; // describe this invocation
} command_line_option;

extern command_line_option command_line_options[];
int cli_arg(int argc, const char *const *argv, command_line_option *o, char *argname, const char **dst, int (*validator)(const char *arg), char *defaultvalue);
int cli_putchar(char c);
int cli_puts(const char *str);
int cli_printf(const char *fmt, ...);
int cli_delim(const char *opt);

int overlay_mdp_getmyaddr(int index,unsigned char *sid);
int overlay_mdp_bind(unsigned char *localaddr,int port); 
int overlay_route_node_info(overlay_mdp_frame *mdp,
			    struct sockaddr_un *addr,int addrlen);
int overlay_interface_register(unsigned char *name,
			       struct sockaddr_in local,
			       struct sockaddr_in broadcast);
int overlay_queue_dump(overlay_txqueue *q);
int overlay_broadcast_ensemble(int interface_number,
			       struct sockaddr_in *recipientaddr /* NULL == broadcast */,
			       unsigned char *bytes,int len);

int app_vomp_status(int argc, const char *const *argv, struct command_line_option *o);
int app_vomp_dial(int argc, const char *const *argv, struct command_line_option *o);
int app_vomp_pickup(int argc, const char *const *argv, struct command_line_option *o);
int app_vomp_hangup(int argc, const char *const *argv, struct command_line_option *o);
int app_vomp_monitor(int argc, const char *const *argv, struct command_line_option *o);
#ifdef HAVE_VOIPTEST
int app_pa_phone(int argc, const char *const *argv, struct command_line_option *o);
#endif
int app_vomp_dtmf(int argc, const char *const *argv, struct command_line_option *o);
int app_monitor_cli(int argc, const char *const *argv, struct command_line_option *o);

int monitor_get_fds(struct pollfd *fds,int *fdcount,int fdmax);

int monitor_setup_sockets();
int monitor_poll();
int monitor_get_fds(struct pollfd *fds,int *fdcount,int fdmax);
int monitor_call_status(vomp_call_state *call);
int monitor_send_audio(vomp_call_state *call,overlay_mdp_frame *audio);
int monitor_announce_peer(unsigned char *sid);
int monitor_tell_clients(unsigned char *msg,int msglen,int mask);
extern int monitor_socket_count;


typedef struct monitor_audio {
  char name[128];
  int (*start)();
  int (*stop)();
  int (*poll_fds)(struct pollfd *,int);
  int (*read)(unsigned char *,int);
  int (*write)(unsigned char *,int);
} monitor_audio;
extern monitor_audio *audev;

monitor_audio *audio_msm_g1_detect();
monitor_audio *audio_alsa_detect();
monitor_audio *audio_reflector_detect();
int detectAudioDevice();
int getAudioPlayFd();
int getAudioRecordFd();
int getAudioBytes(unsigned char *buffer,
		  int offset,
		  int bufferSize);
int encodeAndDispatchRecordedAudio(int fd,int callSessionToken,
				   int recordCodec,
				   unsigned char *sampleData,
				   int sampleBytes);
int scrapeProcNetRoute();
int lsif();
int bufferAudioForPlayback(int codec,long long start_time,long long end_time,
			   unsigned char *data,int dataLen);
int startAudio();
int stopAudio();

#define SERVER_UNKNOWN 1
#define SERVER_NOTRESPONDING 2
#define SERVER_NOTRUNNING 3
#define SERVER_RUNNING 4
int server_probe(int *pid);