gnunet-communicator-udp.c File Reference

Transport plugin using UDP. More...

#include "platform.h"
#include "gnunet_util_lib.h"
#include "gnunet_protocols.h"
#include "gnunet_signatures.h"
#include "gnunet_constants.h"
#include "gnunet_nt_lib.h"
#include "gnunet_nat_service.h"
#include "gnunet_statistics_service.h"
#include "gnunet_transport_application_service.h"
#include "gnunet_transport_communication_service.h"

Include dependency graph for gnunet-communicator-udp.c:

Go to the source code of this file.

Data Structures
struct	UdpHandshakeSignature
	Signature we use to verify that the ephemeral key was really chosen by the specified sender. More...
struct	InitialKX
	"Plaintext" header at beginning of KX message. More...
struct	UDPConfirmation
	Encrypted continuation of UDP initial handshake, followed by message header with payload. More...
struct	UDPAck
	UDP key acknowledgement. More...
struct	UdpBroadcastSignature
	Signature we use to verify that the broadcast was really made by the peer that claims to have made it. More...
struct	UDPBroadcast
	Broadcast by peer in LAN announcing its presence. More...
struct	UDPBox
	UDP message box. More...
struct	KeyCacheEntry
	Pre-generated "kid" code (key and IV identification code) to quickly derive master key for a struct UDPBox. More...
struct	SharedSecret
	Shared secret we generated for a particular sender or receiver. More...
struct	SenderAddress
	Information we track per sender address we have recently been in contact with (we decrypt messages from the sender). More...
struct	ReceiverAddress
	Information we track per receiving address we have recently been in contact with (encryption to receiver). More...
struct	BroadcastInterface
	Interface we broadcast our presence on. More...
struct	SearchContext
	Context information to be used while searching for operation contexts. More...

Macros
#define	REKEY_TIME_INTERVAL   GNUNET_TIME_UNIT_DAYS
	How often do we rekey based on time (at least) More...
#define	PROTO_QUEUE_TIMEOUT   GNUNET_TIME_UNIT_MINUTES
	How long do we wait until we must have received the initial KX? More...
#define	BROADCAST_FREQUENCY   GNUNET_TIME_UNIT_MINUTES
	How often do we broadcast our presence on the LAN? More...
#define	INTERFACE_SCAN_FREQUENCY   GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MINUTES, 5)
	How often do we scan for changes to our network interfaces? More...
#define	ADDRESS_VALIDITY_PERIOD   GNUNET_TIME_UNIT_HOURS
	How long do we believe our addresses to remain up (before the other peer should revalidate). More...
#define	AES_KEY_SIZE   (256 / 8)
	AES key size. More...
#define	AES_IV_SIZE   (96 / 8)
	AES (GCM) IV size. More...
#define	GCM_TAG_SIZE   (128 / 8)
	Size of the GCM tag. More...
#define	KCN_THRESHOLD   92
	If we fall below this number of available KCNs, we generate additional ACKs until we reach KCN_TARGET. More...
#define	KCN_TARGET   128
	How many KCNs do we keep around after we hit the KCN_THRESHOLD? Should be larger than KCN_THRESHOLD so we do not generate just one ACK at the time. More...
#define	MAX_SQN_DELTA   160
	What is the maximum delta between KCN sequence numbers that we allow. More...
#define	MAX_SECRETS   128
	How many shared master secrets do we keep around at most per sender? Should be large enough so that we generally have a chance of sending an ACK before the sender already rotated out the master secret. More...
#define	REKEY_MAX_BYTES   (1024LLU * 1024 * 1024 * 4LLU)
	How often do we rekey based on number of bytes transmitted? (additionally randomized). More...
#define	COMMUNICATOR_ADDRESS_PREFIX   "udp"
	Address prefix used by the communicator. More...
#define	COMMUNICATOR_CONFIG_SECTION   "communicator-udp"
	Configuration section used by the communicator. More...

Functions
static void	bi_destroy (struct BroadcastInterface *bi)
	An interface went away, stop broadcasting on it. More...
static void	receiver_destroy (struct ReceiverAddress *receiver)
	Destroys a receiving state due to timeout or shutdown. More...
static void	kce_destroy (struct KeyCacheEntry *kce)
	Free memory used by key cache entry. More...
static void	get_kid (const struct GNUNET_HashCode *msec, uint32_t serial, struct GNUNET_ShortHashCode *kid)
	Compute kid. More...
static void	kce_generate (struct SharedSecret *ss, uint32_t seq)
	Setup key cache entry for sequence number seq and shared secret ss. More...
static void	secret_destroy (struct SharedSecret *ss)
	Destroy ss and associated key cache entries. More...
static void	sender_destroy (struct SenderAddress *sender)
	Functions with this signature are called whenever we need to close a sender's state due to timeout. More...
static void	get_iv_key (const struct GNUNET_HashCode *msec, uint32_t serial, char key[(256/8)], char iv[(96/8)])
	Compute key and iv. More...
static void	reschedule_sender_timeout (struct SenderAddress *sender)
	Increment sender timeout due to activity. More...
static void	reschedule_receiver_timeout (struct ReceiverAddress *receiver)
	Increment receiver timeout due to activity. More...
static void	check_timeouts (void *cls)
	Task run to check #receiver_heap and #sender_heap for timeouts. More...
static void	calculate_cmac (struct SharedSecret *ss)
	Calcualte cmac from master in ss. More...
static void	pass_plaintext_to_core (struct SenderAddress *sender, const void *plaintext, size_t plaintext_len)
	We received plaintext_len bytes of plaintext from a sender. More...
static void	setup_cipher (const struct GNUNET_HashCode *msec, uint32_t serial, gcry_cipher_hd_t *cipher)
	Setup cipher based on shared secret msec and serial number serial. More...
static int	try_decrypt (const struct SharedSecret *ss, const char tag[(128/8)], uint32_t serial, const char *in_buf, size_t in_buf_size, char *out_buf)
	Try to decrypt buf using shared secret ss and key/iv derived using serial. More...
static struct SharedSecret *	setup_shared_secret_dec (const struct GNUNET_CRYPTO_EcdhePublicKey *ephemeral)
	Setup shared secret for decryption. More...
static struct SharedSecret *	setup_shared_secret_enc (const struct GNUNET_CRYPTO_EcdhePrivateKey *ephemeral, struct ReceiverAddress *receiver)
	Setup shared secret for encryption. More...
static void	setup_receiver_mq (struct ReceiverAddress *receiver)
	Setup the MQ for the receiver. More...
static int	handle_ack (void *cls, const struct GNUNET_PeerIdentity *pid, void *value)
	We received an ACK for pid. More...
static void	try_handle_plaintext (struct SenderAddress *sender, const void *buf, size_t buf_size)
	Test if we have received a valid message in plaintext. More...
static void	consider_ss_ack (struct SharedSecret *ss)
	We established a shared secret with a sender. More...
static void	decrypt_box (const struct UDPBox *box, size_t box_len, struct KeyCacheEntry *kce)
	We received a box with matching kce. More...
static int	find_sender_by_address (void *cls, const struct GNUNET_PeerIdentity *key, void *value)
	Find existing struct SenderAddress by matching addresses. More...
static struct SenderAddress *	setup_sender (const struct GNUNET_PeerIdentity *target, const struct sockaddr *address, socklen_t address_len)
	Create sender address for target. More...
static int	verify_confirmation (const struct GNUNET_CRYPTO_EcdhePublicKey *ephemeral, const struct UDPConfirmation *uc)
	Check signature from uc against ephemeral. More...
static char *	sockaddr_to_udpaddr_string (const struct sockaddr *address, socklen_t address_len)
	Converts address to the address string format used by this communicator in HELLOs. More...
static void	sock_read (void *cls)
	Socket read task. More...
static struct sockaddr *	udp_address_to_sockaddr (const char *bindto, socklen_t *sock_len)
	Convert UDP bind specification to a struct sockaddr * More...
static void	do_pad (gcry_cipher_hd_t out_cipher, char *dgram, size_t pad_size)
	Pad dgram by pad_size using out_cipher. More...
static void	mq_send_kx (struct GNUNET_MQ_Handle *mq, const struct GNUNET_MessageHeader *msg, void *impl_state)
	Signature of functions implementing the sending functionality of a message queue. More...
static void	mq_send_d (struct GNUNET_MQ_Handle *mq, const struct GNUNET_MessageHeader *msg, void *impl_state)
	Signature of functions implementing the sending functionality of a message queue. More...
static void	mq_destroy_d (struct GNUNET_MQ_Handle *mq, void *impl_state)
	Signature of functions implementing the destruction of a message queue. More...
static void	mq_destroy_kx (struct GNUNET_MQ_Handle *mq, void *impl_state)
	Signature of functions implementing the destruction of a message queue. More...
static void	mq_cancel (struct GNUNET_MQ_Handle *mq, void *impl_state)
	Implementation function that cancels the currently sent message. More...
static void	mq_error (void *cls, enum GNUNET_MQ_Error error)
	Generic error handler, called with the appropriate error code and the same closure specified at the creation of the message queue. More...
static int	mq_init (void *cls, const struct GNUNET_PeerIdentity *peer, const char *address)
	Function called by the transport service to initialize a message queue given address information about another peer. More...
static int	get_receiver_delete_it (void *cls, const struct GNUNET_PeerIdentity *target, void *value)
	Iterator over all receivers to clean up. More...
static int	get_sender_delete_it (void *cls, const struct GNUNET_PeerIdentity *target, void *value)
	Iterator over all senders to clean up. More...
static void	do_shutdown (void *cls)
	Shutdown the UNIX communicator. More...
static void	enc_notify_cb (void *cls, const struct GNUNET_PeerIdentity *sender, const struct GNUNET_MessageHeader *msg)
	Function called when the transport service has received a backchannel message for this communicator (!) via a different return path. More...
static void	nat_address_cb (void *cls, void **app_ctx, int add_remove, enum GNUNET_NAT_AddressClass ac, const struct sockaddr *addr, socklen_t addrlen)
	Signature of the callback passed to GNUNET_NAT_register() for a function to call whenever our set of 'valid' addresses changes. More...
static void	ifc_broadcast (void *cls)
	Broadcast our presence on one of our interfaces. More...
static int	iface_proc (void *cls, const char *name, int isDefault, const struct sockaddr *addr, const struct sockaddr *broadcast_addr, const struct sockaddr *netmask, socklen_t addrlen)
	Callback function invoked for each interface found. More...
static void	do_broadcast (void *cls)
	Scan interfaces to broadcast our presence on the LAN. More...
static void	run (void *cls, char *const *args, const char *cfgfile, const struct GNUNET_CONFIGURATION_Handle *c)
	Setup communicator and launch network interactions. More...
int	main (int argc, char *const *argv)
	The main function for the UNIX communicator. More...

Variables
static struct GNUNET_CONTAINER_MultiShortmap *	key_cache
	Cache of pre-generated key IDs. More...
static struct GNUNET_SCHEDULER_Task *	read_task
	ID of read task. More...
static struct GNUNET_SCHEDULER_Task *	timeout_task
	ID of timeout task. More...
static struct GNUNET_SCHEDULER_Task *	broadcast_task
	ID of master broadcast task. More...
static struct GNUNET_STATISTICS_Handle *	stats
	For logging statistics. More...
static struct GNUNET_TRANSPORT_CommunicatorHandle *	ch
	Our environment. More...
static struct GNUNET_CONTAINER_MultiPeerMap *	receivers
	Receivers (map from peer identity to struct ReceiverAddress) More...
static struct GNUNET_CONTAINER_MultiPeerMap *	senders
	Senders (map from peer identity to struct SenderAddress) More...
static struct GNUNET_CONTAINER_Heap *	senders_heap
	Expiration heap for senders (contains struct SenderAddress) More...
static struct GNUNET_CONTAINER_Heap *	receivers_heap
	Expiration heap for receivers (contains struct ReceiverAddress) More...
static struct BroadcastInterface *	bi_head
	Broadcast interface tasks. More...
static struct BroadcastInterface *	bi_tail
	Broadcast interface tasks. More...
static struct GNUNET_NETWORK_Handle *	udp_sock
	Our socket. More...
static int	have_v6_socket
	GNUNET_YES if udp_sock supports IPv6. More...
static struct GNUNET_PeerIdentity	my_identity
	Our public key. More...
static struct GNUNET_CRYPTO_EddsaPrivateKey *	my_private_key
	Our private key. More...
static const struct GNUNET_CONFIGURATION_Handle *	cfg
	Our configuration. More...
static struct GNUNET_TRANSPORT_ApplicationHandle *	ah
	Our handle to report addresses for validation to TRANSPORT. More...
static struct GNUNET_NT_InterfaceScanner *	is
	Network scanner to determine network types. More...
static struct GNUNET_NAT_Handle *	nat
	Connection to NAT service. More...
static uint16_t	my_port
	Port number to which we are actually bound. More...

Detailed Description

Transport plugin using UDP.

Author

Christian Grothoff

TODO:

• consider imposing transmission limits in the absence of ACKs; or: maybe this should be done at TNG service level? (at least the receiver might want to enforce limits on KX/DH operations per sender in here) (#5552)
• overall, we should look more into flow control support (either in backchannel, or general solution in TNG service)
• handle addresses discovered from broadcasts (#5551) (think: what was the story again on address validation? where is the API for that!?!)
• support DNS names in BINDTO option (#5528)
• support NAT connection reversal method (#5529)
• support other UDP-specific NAT traversal methods (#)

Definition in file gnunet-communicator-udp.c.

Macro Definition Documentation

REKEY_TIME_INTERVAL

#define REKEY_TIME_INTERVAL   GNUNET_TIME_UNIT_DAYS

How often do we rekey based on time (at least)

Definition at line 54 of file gnunet-communicator-udp.c.

PROTO_QUEUE_TIMEOUT

#define PROTO_QUEUE_TIMEOUT   GNUNET_TIME_UNIT_MINUTES

How long do we wait until we must have received the initial KX?

Definition at line 59 of file gnunet-communicator-udp.c.

BROADCAST_FREQUENCY

#define BROADCAST_FREQUENCY   GNUNET_TIME_UNIT_MINUTES

How often do we broadcast our presence on the LAN?

Definition at line 64 of file gnunet-communicator-udp.c.

Referenced by ifc_broadcast().

INTERFACE_SCAN_FREQUENCY

#define INTERFACE_SCAN_FREQUENCY   GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MINUTES, 5)

How often do we scan for changes to our network interfaces?

Definition at line 69 of file gnunet-communicator-udp.c.

Referenced by do_broadcast(), and ifc_broadcast().

ADDRESS_VALIDITY_PERIOD

#define ADDRESS_VALIDITY_PERIOD   GNUNET_TIME_UNIT_HOURS

How long do we believe our addresses to remain up (before the other peer should revalidate).

Definition at line 76 of file gnunet-communicator-udp.c.

Referenced by pass_plaintext_to_core().

AES_KEY_SIZE

#define AES_KEY_SIZE   (256 / 8)

AES key size.

Definition at line 81 of file gnunet-communicator-udp.c.

Referenced by setup_cipher().

AES_IV_SIZE

#define AES_IV_SIZE   (96 / 8)

AES (GCM) IV size.

Definition at line 86 of file gnunet-communicator-udp.c.

Referenced by get_iv_key(), and setup_cipher().

GCM_TAG_SIZE

#define GCM_TAG_SIZE   (128 / 8)

Size of the GCM tag.

Definition at line 91 of file gnunet-communicator-udp.c.

KCN_THRESHOLD

#define KCN_THRESHOLD   92

If we fall below this number of available KCNs, we generate additional ACKs until we reach KCN_TARGET.

Should be large enough that we don't generate ACKs all the time and still have enough time for the ACK to arrive before the sender runs out. So really this should ideally be based on the RTT.

Definition at line 102 of file gnunet-communicator-udp.c.

Referenced by consider_ss_ack().

KCN_TARGET

#define KCN_TARGET   128

How many KCNs do we keep around after we hit the KCN_THRESHOLD? Should be larger than KCN_THRESHOLD so we do not generate just one ACK at the time.

Definition at line 110 of file gnunet-communicator-udp.c.

Referenced by consider_ss_ack().

MAX_SQN_DELTA

#define MAX_SQN_DELTA   160

What is the maximum delta between KCN sequence numbers that we allow.

Used to expire 'ancient' KCNs that likely were dropped by the network. Must be larger than KCN_TARGET (otherwise we generate new KCNs all the time), but not too large (otherwise packet loss may cause sender to fall back to KX needlessly when sender runs out of ACK'ed KCNs due to losses).

Definition at line 121 of file gnunet-communicator-udp.c.

Referenced by consider_ss_ack().

MAX_SECRETS

#define MAX_SECRETS   128

How many shared master secrets do we keep around at most per sender? Should be large enough so that we generally have a chance of sending an ACK before the sender already rotated out the master secret.

Generally values around KCN_TARGET make sense. Might make sense to adapt to RTT if we had a good measurement...

Definition at line 132 of file gnunet-communicator-udp.c.

Referenced by sock_read().

REKEY_MAX_BYTES

#define REKEY_MAX_BYTES   (1024LLU * 1024 * 1024 * 4LLU)

How often do we rekey based on number of bytes transmitted? (additionally randomized).

Definition at line 138 of file gnunet-communicator-udp.c.

COMMUNICATOR_ADDRESS_PREFIX

#define COMMUNICATOR_ADDRESS_PREFIX   "udp"

Address prefix used by the communicator.

Definition at line 144 of file gnunet-communicator-udp.c.

Referenced by consider_ss_ack(), mq_init(), nat_address_cb(), run(), and sockaddr_to_udpaddr_string().

COMMUNICATOR_CONFIG_SECTION

#define COMMUNICATOR_CONFIG_SECTION   "communicator-udp"

Configuration section used by the communicator.

Definition at line 149 of file gnunet-communicator-udp.c.

Referenced by run(), and udp_address_to_sockaddr().

Function Documentation

bi_destroy()

static void bi_destroy ( struct BroadcastInterface *  bi )

static

An interface went away, stop broadcasting on it.

Parameters

bi	entity to close down

Definition at line 769 of file gnunet-communicator-udp.c.

References BroadcastInterface::ba, BroadcastInterface::broadcast_task, GNUNET_CONTAINER_DLL_remove, GNUNET_ERROR_TYPE_WARNING, GNUNET_free, GNUNET_log_strerror, GNUNET_NETWORK_socket_setsockopt(), GNUNET_OK, GNUNET_SCHEDULER_cancel(), BroadcastInterface::mcreq, and BroadcastInterface::sa.

Referenced by do_broadcast(), and do_shutdown().

{
  if (AF_INET6 == bi->sa->sa_family)
  {
    /* Leave the multicast group */
    if (GNUNET_OK != GNUNET_NETWORK_socket_setsockopt (udp_sock,
                                                       IPPROTO_IPV6,
                                                       IPV6_LEAVE_GROUP,
                                                       &bi->mcreq,
                                                       sizeof(bi->mcreq)))
    {
      GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "setsockopt");
    }
  }
  GNUNET_CONTAINER_DLL_remove (bi_head, bi_tail, bi);
  GNUNET_SCHEDULER_cancel (bi->broadcast_task);
  GNUNET_free (bi->sa);
  GNUNET_free (bi->ba);
  GNUNET_free (bi);
}

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receiver_destroy()

static void receiver_destroy ( struct ReceiverAddress *  receiver )

static

Destroys a receiving state due to timeout or shutdown.

Parameters

receiver

entity to close down

Definition at line 797 of file gnunet-communicator-udp.c.

References ReceiverAddress::address, ReceiverAddress::d_mq, ReceiverAddress::d_qh, ReceiverAddress::foreign_addr, GNUNET_assert, GNUNET_CONTAINER_heap_remove_node(), GNUNET_CONTAINER_multipeermap_remove(), GNUNET_CONTAINER_multipeermap_size(), GNUNET_ERROR_TYPE_DEBUG, GNUNET_free, GNUNET_i2s(), GNUNET_log, GNUNET_MQ_destroy(), GNUNET_NO, GNUNET_STATISTICS_set(), GNUNET_TRANSPORT_communicator_mq_del(), GNUNET_YES, ReceiverAddress::hn, ReceiverAddress::kx_mq, ReceiverAddress::kx_qh, mq, and ReceiverAddress::target.

Referenced by check_timeouts(), get_receiver_delete_it(), mq_destroy_d(), mq_destroy_kx(), mq_error(), mq_send_d(), and mq_send_kx().

{
  struct GNUNET_MQ_Handle *mq;

  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "Disconnecting receiver for peer `%s'\n",
              GNUNET_i2s (&receiver->target));
  if (NULL != (mq = receiver->kx_mq))
  {
    receiver->kx_mq = NULL;
    GNUNET_MQ_destroy (mq);
  }
  if (NULL != receiver->kx_qh)
  {
    GNUNET_TRANSPORT_communicator_mq_del (receiver->kx_qh);
    receiver->kx_qh = NULL;
  }
  if (NULL != (mq = receiver->d_mq))
  {
    receiver->d_mq = NULL;
    GNUNET_MQ_destroy (mq);
  }
  if (NULL != receiver->d_qh)
  {
    GNUNET_TRANSPORT_communicator_mq_del (receiver->d_qh);
    receiver->d_qh = NULL;
  }
  GNUNET_assert (GNUNET_YES ==
                 GNUNET_CONTAINER_multipeermap_remove (receivers,
                                                       &receiver->target,
                                                       receiver));
  GNUNET_assert (receiver == GNUNET_CONTAINER_heap_remove_node (receiver->hn));
  GNUNET_STATISTICS_set (stats,
                         "# receivers active",
                         GNUNET_CONTAINER_multipeermap_size (receivers),
                         GNUNET_NO);
  GNUNET_free (receiver->address);
  GNUNET_free (receiver->foreign_addr);
  GNUNET_free (receiver);
}

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kce_destroy()

static void kce_destroy ( struct KeyCacheEntry *  kce )

static

Free memory used by key cache entry.

Parameters

kce	the key cache entry

Definition at line 845 of file gnunet-communicator-udp.c.

References SharedSecret::active_kce_count, GNUNET_assert, GNUNET_CONTAINER_DLL_remove, GNUNET_CONTAINER_multishortmap_remove(), GNUNET_free, GNUNET_YES, SharedSecret::kce_head, SharedSecret::kce_tail, KeyCacheEntry::kid, and KeyCacheEntry::ss.

Referenced by consider_ss_ack(), decrypt_box(), and secret_destroy().

{
  struct SharedSecret *ss = kce->ss;

  ss->active_kce_count--;
  GNUNET_CONTAINER_DLL_remove (ss->kce_head, ss->kce_tail, kce);
  GNUNET_assert (GNUNET_YES == GNUNET_CONTAINER_multishortmap_remove (key_cache,
                                                                      &kce->kid,
                                                                      kce));
  GNUNET_free (kce);
}

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get_kid()

static void get_kid ( const struct GNUNET_HashCode *  msec, uint32_t  serial, struct GNUNET_ShortHashCode *  kid  )

static

Compute kid.

Parameters

msec	master secret for HMAC calculation
serial	number for the smac calculation
kid[out]	where to write the key ID

Definition at line 866 of file gnunet-communicator-udp.c.

References GNUNET_CRYPTO_hkdf().

Referenced by kce_generate(), and mq_send_d().

{
  uint32_t sid = htonl (serial);

  GNUNET_CRYPTO_hkdf (kid,
                      sizeof(*kid),
                      GCRY_MD_SHA512,
                      GCRY_MD_SHA256,
                      &sid,
                      sizeof(sid),
                      msec,
                      sizeof(*msec),
                      "UDP-KID",
                      strlen ("UDP-KID"),
                      NULL,
                      0);
}

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kce_generate()

static void kce_generate ( struct SharedSecret *  ss, uint32_t  seq  )

static

Setup key cache entry for sequence number seq and shared secret ss.

Parameters

ss	shared secret
seq	sequence number for the key cache entry

Definition at line 894 of file gnunet-communicator-udp.c.

References SharedSecret::active_kce_count, get_kid(), GNUNET_assert, GNUNET_CONTAINER_DLL_insert, GNUNET_CONTAINER_MULTIHASHMAPOPTION_MULTIPLE, GNUNET_CONTAINER_multishortmap_put(), GNUNET_CONTAINER_multishortmap_size(), GNUNET_new, GNUNET_NO, GNUNET_STATISTICS_set(), SharedSecret::kce_head, SharedSecret::kce_tail, KeyCacheEntry::kid, SharedSecret::master, KeyCacheEntry::sequence_number, and KeyCacheEntry::ss.

Referenced by consider_ss_ack().

{
  struct KeyCacheEntry *kce;

  GNUNET_assert (0 < seq);
  kce = GNUNET_new (struct KeyCacheEntry);
  kce->ss = ss;
  kce->sequence_number = seq;
  get_kid (&ss->master, seq, &kce->kid);
  GNUNET_CONTAINER_DLL_insert (ss->kce_head, ss->kce_tail, kce);
  ss->active_kce_count++;
  (void) GNUNET_CONTAINER_multishortmap_put (
    key_cache,
    &kce->kid,
    kce,
    GNUNET_CONTAINER_MULTIHASHMAPOPTION_MULTIPLE);
  GNUNET_STATISTICS_set (stats,
                         "# KIDs active",
                         GNUNET_CONTAINER_multishortmap_size (key_cache),
                         GNUNET_NO);
}

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secret_destroy()

static void secret_destroy ( struct SharedSecret *  ss )

static

Destroy ss and associated key cache entries.

Parameters

ss	shared secret to destroy

Definition at line 923 of file gnunet-communicator-udp.c.

References ReceiverAddress::acks_available, GNUNET_CONTAINER_DLL_remove, GNUNET_CONTAINER_multishortmap_size(), GNUNET_free, GNUNET_NO, GNUNET_STATISTICS_set(), GNUNET_STATISTICS_update(), kce_destroy(), SharedSecret::kce_head, SenderAddress::num_secrets, ReceiverAddress::num_secrets, SharedSecret::receiver, UdpHandshakeSignature::receiver, SharedSecret::sender, UdpHandshakeSignature::sender, SharedSecret::sequence_allowed, SharedSecret::sequence_used, SenderAddress::ss_head, ReceiverAddress::ss_head, SenderAddress::ss_tail, and ReceiverAddress::ss_tail.

Referenced by sock_read().

{
  struct SenderAddress *sender;
  struct ReceiverAddress *receiver;
  struct KeyCacheEntry *kce;

  if (NULL != (sender = ss->sender))
  {
    GNUNET_CONTAINER_DLL_remove (sender->ss_head, sender->ss_tail, ss);
    sender->num_secrets--;
  }
  if (NULL != (receiver = ss->receiver))
  {
    GNUNET_CONTAINER_DLL_remove (receiver->ss_head, receiver->ss_tail, ss);
    receiver->num_secrets--;
    receiver->acks_available -= (ss->sequence_allowed - ss->sequence_used);
  }
  while (NULL != (kce = ss->kce_head))
    kce_destroy (kce);
  GNUNET_STATISTICS_update (stats, "# Secrets active", -1, GNUNET_NO);
  GNUNET_STATISTICS_set (stats,
                         "# KIDs active",
                         GNUNET_CONTAINER_multishortmap_size (key_cache),
                         GNUNET_NO);
  GNUNET_free (ss);
}

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sender_destroy()

static void sender_destroy ( struct SenderAddress *  sender )

static

Functions with this signature are called whenever we need to close a sender's state due to timeout.

Parameters

sender

entity to close down

Definition at line 958 of file gnunet-communicator-udp.c.

References SenderAddress::address, GNUNET_assert, GNUNET_CONTAINER_heap_remove_node(), GNUNET_CONTAINER_multipeermap_remove(), GNUNET_CONTAINER_multipeermap_size(), GNUNET_free, GNUNET_NO, GNUNET_STATISTICS_set(), GNUNET_YES, SenderAddress::hn, and SenderAddress::target.

Referenced by check_timeouts(), and get_sender_delete_it().

{
  GNUNET_assert (
    GNUNET_YES ==
    GNUNET_CONTAINER_multipeermap_remove (senders, &sender->target, sender));
  GNUNET_assert (sender == GNUNET_CONTAINER_heap_remove_node (sender->hn));
  GNUNET_STATISTICS_set (stats,
                         "# senders active",
                         GNUNET_CONTAINER_multipeermap_size (senders),
                         GNUNET_NO);
  GNUNET_free (sender->address);
  GNUNET_free (sender);
}

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get_iv_key()

static void get_iv_key ( const struct GNUNET_HashCode *  msec, uint32_t  serial, char  key[(256/8)], char  iv[(96/8)]  )

static

Compute key and iv.

Parameters

msec	master secret for calculation
serial	number for the smac calculation
key[out]	where to write the decrption key
iv[out]	where to write the IV

Definition at line 982 of file gnunet-communicator-udp.c.

References AES_IV_SIZE, GNUNET_CRYPTO_hkdf(), key, and res.

Referenced by setup_cipher().

{
  uint32_t sid = htonl (serial);
  char res[AES_KEY_SIZE + AES_IV_SIZE];

  GNUNET_CRYPTO_hkdf (res,
                      sizeof(res),
                      GCRY_MD_SHA512,
                      GCRY_MD_SHA256,
                      &sid,
                      sizeof(sid),
                      msec,
                      sizeof(*msec),
                      "UDP-IV-KEY",
                      strlen ("UDP-IV-KEY"),
                      NULL,
                      0);
  memcpy (key, res, AES_KEY_SIZE);
  memcpy (iv, &res[AES_KEY_SIZE], AES_IV_SIZE);
}

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reschedule_sender_timeout()

static void reschedule_sender_timeout ( struct SenderAddress *  sender )

static

Increment sender timeout due to activity.

Parameters

sender

address for which the timeout should be rescheduled

Definition at line 1013 of file gnunet-communicator-udp.c.

References GNUNET_TIME_Absolute::abs_value_us, GNUNET_CONSTANTS_IDLE_CONNECTION_TIMEOUT, GNUNET_CONTAINER_heap_update_cost(), GNUNET_TIME_relative_to_absolute(), SenderAddress::hn, and SenderAddress::timeout.

Referenced by setup_sender().

{
  sender->timeout =
    GNUNET_TIME_relative_to_absolute (GNUNET_CONSTANTS_IDLE_CONNECTION_TIMEOUT);
  GNUNET_CONTAINER_heap_update_cost (sender->hn, sender->timeout.abs_value_us);
}

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reschedule_receiver_timeout()

static void reschedule_receiver_timeout ( struct ReceiverAddress *  receiver )

static

Increment receiver timeout due to activity.

Parameters

receiver

address for which the timeout should be rescheduled

Definition at line 1027 of file gnunet-communicator-udp.c.

References GNUNET_TIME_Absolute::abs_value_us, GNUNET_CONSTANTS_IDLE_CONNECTION_TIMEOUT, GNUNET_CONTAINER_heap_update_cost(), GNUNET_TIME_relative_to_absolute(), ReceiverAddress::hn, and ReceiverAddress::timeout.

Referenced by mq_send_d(), and mq_send_kx().

{
  receiver->timeout =
    GNUNET_TIME_relative_to_absolute (GNUNET_CONSTANTS_IDLE_CONNECTION_TIMEOUT);
  GNUNET_CONTAINER_heap_update_cost (receiver->hn,
                                     receiver->timeout.abs_value_us);
}

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check_timeouts()

static void check_timeouts ( void *  cls )

static

Task run to check #receiver_heap and #sender_heap for timeouts.

Parameters

cls	unused, NULL

Definition at line 1042 of file gnunet-communicator-udp.c.

References GNUNET_CONTAINER_heap_peek(), GNUNET_ERROR_TYPE_DEBUG, GNUNET_log, GNUNET_SCHEDULER_add_delayed(), GNUNET_TIME_absolute_get_remaining(), GNUNET_TIME_relative_min(), GNUNET_TIME_UNIT_FOREVER_REL, UdpHandshakeSignature::receiver, receiver_destroy(), GNUNET_TIME_Relative::rel_value_us, UdpHandshakeSignature::sender, sender_destroy(), SenderAddress::timeout, and ReceiverAddress::timeout.

Referenced by mq_init(), and setup_sender().

{
  struct GNUNET_TIME_Relative st;
  struct GNUNET_TIME_Relative rt;
  struct GNUNET_TIME_Relative delay;
  struct ReceiverAddress *receiver;
  struct SenderAddress *sender;

  (void) cls;
  timeout_task = NULL;
  rt = GNUNET_TIME_UNIT_FOREVER_REL;
  while (NULL != (receiver = GNUNET_CONTAINER_heap_peek (receivers_heap)))
  {
    rt = GNUNET_TIME_absolute_get_remaining (receiver->timeout);
    if (0 != rt.rel_value_us)
      break;
    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                "Receiver timed out\n");
    receiver_destroy (receiver);
  }
  st = GNUNET_TIME_UNIT_FOREVER_REL;
  while (NULL != (sender = GNUNET_CONTAINER_heap_peek (senders_heap)))
  {
    st = GNUNET_TIME_absolute_get_remaining (sender->timeout);
    if (0 != st.rel_value_us)
      break;
    sender_destroy (sender);
  }
  delay = GNUNET_TIME_relative_min (rt, st);
  if (delay.rel_value_us < GNUNET_TIME_UNIT_FOREVER_REL.rel_value_us)
    timeout_task = GNUNET_SCHEDULER_add_delayed (delay, &check_timeouts, NULL);
}

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calculate_cmac()

static void calculate_cmac ( struct SharedSecret *  ss )

static

Calcualte cmac from master in ss.

Parameters

ss[in,out]

data structure to complete

Definition at line 1082 of file gnunet-communicator-udp.c.

References SharedSecret::cmac, GNUNET_CRYPTO_hkdf(), and SharedSecret::master.

Referenced by setup_shared_secret_enc(), and sock_read().

{
  GNUNET_CRYPTO_hkdf (&ss->cmac,
                      sizeof(ss->cmac),
                      GCRY_MD_SHA512,
                      GCRY_MD_SHA256,
                      "CMAC",
                      strlen ("CMAC"),
                      &ss->master,
                      sizeof(ss->master),
                      "UDP-CMAC",
                      strlen ("UDP-CMAC"),
                      NULL,
                      0);
}

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pass_plaintext_to_core()

static void pass_plaintext_to_core ( struct SenderAddress *  sender, const void *  plaintext, size_t  plaintext_len  )

static

We received plaintext_len bytes of plaintext from a sender.

Pass it on to CORE.

Parameters

queue	the queue that received the plaintext
plaintext	the plaintext that was received
plaintext_len	number of bytes of plaintext received

Definition at line 1108 of file gnunet-communicator-udp.c.

References ADDRESS_VALIDITY_PERIOD, GNUNET_assert, GNUNET_ERROR_TYPE_DEBUG, GNUNET_log, GNUNET_NO, GNUNET_STATISTICS_update(), GNUNET_SYSERR, GNUNET_TRANSPORT_communicator_receive(), GNUNET_MessageHeader::size, and SenderAddress::target.

Referenced by try_handle_plaintext().

{
  const struct GNUNET_MessageHeader *hdr = plaintext;
  const char *pos = plaintext;

  while (ntohs (hdr->size) < plaintext_len)
  {
    GNUNET_STATISTICS_update (stats,
                              "# bytes given to core",
                              ntohs (hdr->size),
                              GNUNET_NO);
    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                "Giving %u bytes to TNG\n", ntohs (hdr->size));
    GNUNET_assert (GNUNET_SYSERR !=
                   GNUNET_TRANSPORT_communicator_receive (ch,
                                                          &sender->target,
                                                          hdr,
                                                          ADDRESS_VALIDITY_PERIOD,
                                                          NULL /* no flow control possible */
                                                          ,
                                                          NULL));
    /* move on to next message, if any */
    plaintext_len -= ntohs (hdr->size);
    if (plaintext_len < sizeof(*hdr))
      break;
    pos += ntohs (hdr->size);
    hdr = (const struct GNUNET_MessageHeader *) pos;
    // TODO for now..., we do not actually sen >1msg or have a way of telling
    // if we are done
    break;
  }
  GNUNET_STATISTICS_update (stats,
                            "# bytes padding discarded",
                            plaintext_len,
                            GNUNET_NO);
}

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setup_cipher()

static void setup_cipher ( const struct GNUNET_HashCode *  msec, uint32_t  serial, gcry_cipher_hd_t *  cipher  )

static

Setup cipher based on shared secret msec and serial number serial.

Parameters

msec	master shared secret
serial	serial number of cipher to set up
cipher[out]	cipher to initialize

Definition at line 1157 of file gnunet-communicator-udp.c.

References AES_IV_SIZE, AES_KEY_SIZE, get_iv_key(), GNUNET_assert, and key.

Referenced by mq_send_d(), mq_send_kx(), and try_decrypt().

{
  char key[AES_KEY_SIZE];
  char iv[AES_IV_SIZE];
  int rc;

  GNUNET_assert (0 ==
                 gcry_cipher_open (cipher,
                                   GCRY_CIPHER_AES256 /* low level: go for speed */,
                                   GCRY_CIPHER_MODE_GCM,
                                   0 /* flags */));
  get_iv_key (msec, serial, key, iv);
  rc = gcry_cipher_setkey (*cipher, key, sizeof(key));
  GNUNET_assert ((0 == rc) || ((char) rc == GPG_ERR_WEAK_KEY));
  rc = gcry_cipher_setiv (*cipher, iv, sizeof(iv));
  GNUNET_assert ((0 == rc) || ((char) rc == GPG_ERR_WEAK_KEY));
}

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try_decrypt()

static int try_decrypt ( const struct SharedSecret *  ss, const char  tag[(128/8)], uint32_t  serial, const char *  in_buf, size_t  in_buf_size, char *  out_buf  )

static

Try to decrypt buf using shared secret ss and key/iv derived using serial.

Parameters

ss	shared secret
tag	GCM authentication tag
serial	serial number to use
in_buf	input buffer to decrypt
in_buf_size	number of bytes in in_buf and available in out_buf
out_buf	where to write the result

Returns

GNUNET_OK on success

Definition at line 1191 of file gnunet-communicator-udp.c.

References GNUNET_assert, GNUNET_NO, GNUNET_OK, GNUNET_STATISTICS_update(), GNUNET_SYSERR, SharedSecret::master, and setup_cipher().

Referenced by decrypt_box(), and sock_read().

{
  gcry_cipher_hd_t cipher;

  setup_cipher (&ss->master, serial, &cipher);
  GNUNET_assert (
    0 ==
    gcry_cipher_decrypt (cipher, out_buf, in_buf_size, in_buf, in_buf_size));
  if (0 != gcry_cipher_checktag (cipher, tag, GCM_TAG_SIZE))
  {
    gcry_cipher_close (cipher);
    GNUNET_STATISTICS_update (stats,
                              "# AEAD authentication failures",
                              1,
                              GNUNET_NO);
    return GNUNET_SYSERR;
  }
  gcry_cipher_close (cipher);
  return GNUNET_OK;
}

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setup_shared_secret_dec()

static struct SharedSecret* setup_shared_secret_dec ( const struct GNUNET_CRYPTO_EcdhePublicKey *  ephemeral )

static

Setup shared secret for decryption.

Parameters

ephemeral

ephemeral key we received from the other peer

Returns

new shared secret

Definition at line 1225 of file gnunet-communicator-udp.c.

References GNUNET_CRYPTO_eddsa_ecdh(), GNUNET_new, and SharedSecret::master.

Referenced by sock_read().

{
  struct SharedSecret *ss;

  ss = GNUNET_new (struct SharedSecret);
  GNUNET_CRYPTO_eddsa_ecdh (my_private_key, ephemeral, &ss->master);
  return ss;
}

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setup_shared_secret_enc()

static struct SharedSecret* setup_shared_secret_enc ( const struct GNUNET_CRYPTO_EcdhePrivateKey *  ephemeral, struct ReceiverAddress *  receiver  )

static

Setup shared secret for encryption.

Parameters

ephemeral	ephemeral key we are sending to the other peer
receiver[in,out]	queue to initialize encryption key for

Returns

new shared secret

Definition at line 1243 of file gnunet-communicator-udp.c.

References calculate_cmac(), GNUNET_CONTAINER_DLL_insert, GNUNET_CRYPTO_ecdh_eddsa(), GNUNET_new, GNUNET_NO, GNUNET_STATISTICS_update(), SharedSecret::master, ReceiverAddress::num_secrets, GNUNET_PeerIdentity::public_key, SharedSecret::receiver, UdpHandshakeSignature::receiver, setup_receiver_mq(), ReceiverAddress::ss_head, ReceiverAddress::ss_tail, and ReceiverAddress::target.

Referenced by mq_send_kx().

{
  struct SharedSecret *ss;

  ss = GNUNET_new (struct SharedSecret);
  GNUNET_CRYPTO_ecdh_eddsa (ephemeral,
                            &receiver->target.public_key,
                            &ss->master);
  calculate_cmac (ss);
  ss->receiver = receiver;
  GNUNET_CONTAINER_DLL_insert (receiver->ss_head, receiver->ss_tail, ss);
  receiver->num_secrets++;
  GNUNET_STATISTICS_update (stats, "# Secrets active", 1, GNUNET_NO);
  return ss;
}

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setup_receiver_mq()

static void setup_receiver_mq ( struct ReceiverAddress *  receiver )

static

Setup the MQ for the receiver.

If a queue exists, the existing one is destroyed. Then the MTU is recalculated and a fresh queue is initialized.

Parameters

receiver

receiver to setup MQ for

Definition at line 2166 of file gnunet-communicator-udp.c.

References ReceiverAddress::address, ReceiverAddress::d_mq, ReceiverAddress::d_mtu, ReceiverAddress::d_qh, ReceiverAddress::foreign_addr, GNUNET_assert, GNUNET_ERROR_TYPE_DEBUG, GNUNET_log, GNUNET_MQ_queue_for_callbacks(), GNUNET_TRANSPORT_communicator_mq_add(), GNUNET_TRANSPORT_CS_OUTBOUND, GNUNET_TRANSPORT_QUEUE_LENGTH_UNLIMITED, ReceiverAddress::kx_mq, ReceiverAddress::kx_mtu, ReceiverAddress::kx_qh, mq_cancel(), mq_destroy_d(), mq_destroy_kx(), mq_error(), mq_send_d(), mq_send_kx(), ReceiverAddress::nt, and ReceiverAddress::target.

Referenced by mq_init(), and setup_shared_secret_enc().

{
  size_t base_mtu;

  /*if (NULL != receiver->kx_qh)
  {
    GNUNET_TRANSPORT_communicator_mq_del (receiver->kx_qh);
    receiver->kx_qh = NULL;
  }
  if (NULL != receiver->d_qh)
  {
    GNUNET_TRANSPORT_communicator_mq_del (receiver->d_qh);
    receiver->d_qh = NULL;
  }*/
  // GNUNET_assert (NULL == receiver->mq);
  switch (receiver->address->sa_family)
  {
  case AF_INET:
    base_mtu = 1480   /* Ethernet MTU, 1500 - Ethernet header - VLAN tag */
               - sizeof(struct GNUNET_TUN_IPv4Header)   /* 20 */
               - sizeof(struct GNUNET_TUN_UdpHeader) /* 8 */;
    break;

  case AF_INET6:
    base_mtu = 1280   /* Minimum MTU required by IPv6 */
               - sizeof(struct GNUNET_TUN_IPv6Header)   /* 40 */
               - sizeof(struct GNUNET_TUN_UdpHeader) /* 8 */;
    break;

  default:
    GNUNET_assert (0);
    break;
  }
  /* MTU based on full KX messages */
  receiver->kx_mtu = base_mtu - sizeof(struct InitialKX)   /* 48 */
                     - sizeof(struct UDPConfirmation); /* 104 */
  /* MTU based on BOXed messages */
  receiver->d_mtu = base_mtu - sizeof(struct UDPBox);

  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "Setting up MQs and QHs\n");
  /* => Effective MTU for CORE will range from 1080 (IPv6 + KX) to
     1404 (IPv4 + Box) bytes, depending on circumstances... */
  if (NULL == receiver->kx_mq)
    receiver->kx_mq = GNUNET_MQ_queue_for_callbacks (&mq_send_kx,
                                                     &mq_destroy_kx,
                                                     &mq_cancel,
                                                     receiver,
                                                     NULL,
                                                     &mq_error,
                                                     receiver);
  if (NULL == receiver->d_mq)
    receiver->d_mq = GNUNET_MQ_queue_for_callbacks (&mq_send_d,
                                                    &mq_destroy_d,
                                                    &mq_cancel,
                                                    receiver,
                                                    NULL,
                                                    &mq_error,
                                                    receiver);

  receiver->kx_qh =
    GNUNET_TRANSPORT_communicator_mq_add (ch,
                                          &receiver->target,
                                          receiver->foreign_addr,
                                          receiver->kx_mtu,
                                          GNUNET_TRANSPORT_QUEUE_LENGTH_UNLIMITED,
                                          0, /* Priority */
                                          receiver->nt,
                                          GNUNET_TRANSPORT_CS_OUTBOUND,
                                          receiver->kx_mq);
  receiver->d_qh =
    GNUNET_TRANSPORT_communicator_mq_add (ch,
                                          &receiver->target,
                                          receiver->foreign_addr,
                                          receiver->d_mtu,
                                          0, /* Initialize with 0 acks */
                                          1, /* Priority */
                                          receiver->nt,
                                          GNUNET_TRANSPORT_CS_OUTBOUND,
                                          receiver->d_mq);

}

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handle_ack()

static int handle_ack ( void *  cls, const struct GNUNET_PeerIdentity *  pid, void *  value  )

static

We received an ACK for pid.

Check if it is for the receiver in value and if so, handle it and return GNUNET_NO. Otherwise, return GNUNET_YES.

Parameters

cls	a const struct UDPAck
pid	peer the ACK is from
value	a struct ReceiverAddress

Returns

GNUNET_YES to continue to iterate

Definition at line 1283 of file gnunet-communicator-udp.c.

References ReceiverAddress::acks_available, UDPAck::cmac, ReceiverAddress::d_qh, GNUNET_CONTAINER_DLL_insert, GNUNET_CONTAINER_DLL_remove, GNUNET_ERROR_TYPE_DEBUG, GNUNET_log, GNUNET_NO, GNUNET_TRANSPORT_communicator_mq_update(), GNUNET_YES, SharedSecret::next, UDPAck::sequence_max, ReceiverAddress::ss_head, ReceiverAddress::ss_tail, and value.

Referenced by enc_notify_cb(), and try_handle_plaintext().

{
  const struct UDPAck *ack = cls;
  struct ReceiverAddress *receiver = value;
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "in handle ack\n");

  (void) pid;
  for (struct SharedSecret *ss = receiver->ss_head; NULL != ss; ss = ss->next)
  {
    if (0 == memcmp (&ack->cmac, &ss->cmac, sizeof(struct GNUNET_HashCode)))
    {
      uint32_t allowed;
      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                  "Found matching mac\n");

      allowed = ntohl (ack->sequence_max);

      if (allowed > ss->sequence_allowed)
      {
        GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                    "%u > %u (%u)\n", allowed, ss->sequence_allowed,
                    receiver->acks_available);

        receiver->acks_available += (allowed - ss->sequence_allowed);
        GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                    "Tell transport we have more acks!\n");
        GNUNET_TRANSPORT_communicator_mq_update (ch,
                                                 receiver->d_qh,
                                                 (allowed - ss->sequence_allowed),
                                                 1);
        ss->sequence_allowed = allowed;
        /* move ss to head to avoid discarding it anytime soon! */
        GNUNET_CONTAINER_DLL_remove (receiver->ss_head, receiver->ss_tail, ss);
        GNUNET_CONTAINER_DLL_insert (receiver->ss_head, receiver->ss_tail, ss);
      }
      return GNUNET_NO;
    }
  }
  return GNUNET_YES;
}

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try_handle_plaintext()

static void try_handle_plaintext ( struct SenderAddress *  sender, const void *  buf, size_t  buf_size  )

static

Test if we have received a valid message in plaintext.

If so, handle it.

Parameters

sender	peer to process inbound plaintext for
buf	buffer we received
buf_size	number of bytes in buf

Definition at line 1335 of file gnunet-communicator-udp.c.

References GNUNET_CONTAINER_multipeermap_get_multiple(), GNUNET_MESSAGE_TYPE_COMMUNICATOR_UDP_ACK, GNUNET_MESSAGE_TYPE_COMMUNICATOR_UDP_PAD, handle_ack(), pass_plaintext_to_core(), GNUNET_MessageHeader::size, SenderAddress::target, type, and GNUNET_MessageHeader::type.

Referenced by decrypt_box(), and sock_read().

{
  const struct GNUNET_MessageHeader *hdr =
    (const struct GNUNET_MessageHeader *) buf;
  const struct UDPAck *ack = (const struct UDPAck *) buf;
  uint16_t type;

  if (sizeof(*hdr) > buf_size)
    return; /* not even a header */
  if (ntohs (hdr->size) > buf_size)
    return; /* not even a header */
  type = ntohs (hdr->type);
  switch (type)
  {
  case GNUNET_MESSAGE_TYPE_COMMUNICATOR_UDP_ACK:
    /* lookup master secret by 'cmac', then update sequence_max */
    GNUNET_CONTAINER_multipeermap_get_multiple (receivers,
                                                &sender->target,
                                                &handle_ack,
                                                (void *) ack);
    /* There could be more messages after the ACK, handle those as well */
    buf += ntohs (hdr->size);
    buf_size -= ntohs (hdr->size);
    pass_plaintext_to_core (sender, buf, buf_size);
    break;

  case GNUNET_MESSAGE_TYPE_COMMUNICATOR_UDP_PAD:
    /* skip padding */
    break;

  default:
    pass_plaintext_to_core (sender, buf, buf_size);
  }
}

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consider_ss_ack()

static void consider_ss_ack ( struct SharedSecret *  ss )

static

We established a shared secret with a sender.

We should try to send the sender an struct UDPAck at the next opportunity to allow the sender to use ss longer (assuming we did not yet already recently).

Parameters

ss	shared secret to generate ACKs for

Definition at line 1382 of file gnunet-communicator-udp.c.

References SharedSecret::active_kce_count, UDPAck::cmac, SharedSecret::cmac, COMMUNICATOR_ADDRESS_PREFIX, GNUNET_assert, GNUNET_ERROR_TYPE_DEBUG, GNUNET_i2s_full(), GNUNET_log, GNUNET_MESSAGE_TYPE_COMMUNICATOR_UDP_ACK, GNUNET_TRANSPORT_communicator_notify(), UDPAck::header, kce_destroy(), kce_generate(), SharedSecret::kce_head, SharedSecret::kce_tail, KCN_TARGET, KCN_THRESHOLD, MAX_SQN_DELTA, SharedSecret::sender, SharedSecret::sequence_allowed, UDPAck::sequence_max, KeyCacheEntry::sequence_number, GNUNET_MessageHeader::size, SenderAddress::target, and GNUNET_MessageHeader::type.

Referenced by decrypt_box(), and sock_read().

{
  GNUNET_assert (NULL != ss->sender);
  /* drop ancient KeyCacheEntries */
  while ((NULL != ss->kce_head) &&
         (MAX_SQN_DELTA <
          ss->kce_head->sequence_number - ss->kce_tail->sequence_number))
    kce_destroy (ss->kce_tail);
  if (ss->active_kce_count < KCN_THRESHOLD)
  {
    struct UDPAck ack;

    while (ss->active_kce_count < KCN_TARGET)
      kce_generate (ss, ++ss->sequence_allowed);
    ack.header.type = htons (GNUNET_MESSAGE_TYPE_COMMUNICATOR_UDP_ACK);
    ack.header.size = htons (sizeof(ack));
    ack.sequence_max = htonl (ss->sequence_allowed);
    ack.cmac = ss->cmac;
    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                "Notifying transport of UDPAck %s\n",
                GNUNET_i2s_full (&ss->sender->target));
    GNUNET_TRANSPORT_communicator_notify (ch,
                                          &ss->sender->target,
                                          COMMUNICATOR_ADDRESS_PREFIX,
                                          &ack.header);
  }
}

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decrypt_box()

static void decrypt_box ( const struct UDPBox *  box, size_t  box_len, struct KeyCacheEntry *  kce  )

static

We received a box with matching kce.

Decrypt and process it.

Parameters

box	the data we received
box_len	number of bytes in box
kce	key index to decrypt box

Definition at line 1419 of file gnunet-communicator-udp.c.

References consider_ss_ack(), UDPBox::gcm_tag, GNUNET_assert, GNUNET_NO, GNUNET_OK, GNUNET_STATISTICS_update(), kce_destroy(), SharedSecret::sender, KeyCacheEntry::sequence_number, KeyCacheEntry::ss, try_decrypt(), and try_handle_plaintext().

Referenced by sock_read().

{
  struct SharedSecret *ss = kce->ss;
  char out_buf[box_len - sizeof(*box)];

  GNUNET_assert (NULL != ss->sender);
  if (GNUNET_OK != try_decrypt (ss,
                                box->gcm_tag,
                                kce->sequence_number,
                                (const char *) &box[1],
                                sizeof(out_buf),
                                out_buf))
  {
    GNUNET_STATISTICS_update (stats,
                              "# Decryption failures with valid KCE",
                              1,
                              GNUNET_NO);
    kce_destroy (kce);
    return;
  }
  kce_destroy (kce);
  GNUNET_STATISTICS_update (stats,
                            "# bytes decrypted with BOX",
                            sizeof(out_buf),
                            GNUNET_NO);
  try_handle_plaintext (ss->sender, out_buf, sizeof(out_buf));
  consider_ss_ack (ss);
}

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find_sender_by_address()

static int find_sender_by_address ( void *  cls, const struct GNUNET_PeerIdentity *  key, void *  value  )

static

Find existing struct SenderAddress by matching addresses.

Parameters

cls	a struct SearchContext
key	ignored, must match already
value	a struct SenderAddress

Returns

GNUNET_YES if not found (continue to search), GNUNET_NO if found

Definition at line 1482 of file gnunet-communicator-udp.c.

References SenderAddress::address, SearchContext::address, SenderAddress::address_len, SearchContext::address_len, GNUNET_NO, GNUNET_YES, sc, SearchContext::sender, UdpHandshakeSignature::sender, and value.

Referenced by setup_sender().

{
  struct SearchContext *sc = cls;
  struct SenderAddress *sender = value;

  if ((sender->address_len == sc->address_len) &&
      (0 == memcmp (sender->address, sc->address, sender->address_len)))
  {
    sc->sender = sender;
    return GNUNET_NO;   /* stop iterating! */
  }
  return GNUNET_YES;
}

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setup_sender()

static struct SenderAddress* setup_sender ( const struct GNUNET_PeerIdentity *  target, const struct sockaddr *  address, socklen_t  address_len  )

static

Create sender address for target.

Note that we might already have one, so a fresh one is only allocated if one does not yet exist for address.

Parameters

target	peer to generate address for
address	target address
address_len	number of bytes in address

Returns

data structure to keep track of key material for decrypting data from target

Definition at line 1511 of file gnunet-communicator-udp.c.

References GNUNET_TIME_Absolute::abs_value_us, address, SenderAddress::address, SearchContext::address, SenderAddress::address_len, SearchContext::address_len, check_timeouts(), find_sender_by_address(), GNUNET_CONSTANTS_IDLE_CONNECTION_TIMEOUT, GNUNET_CONTAINER_heap_insert(), GNUNET_CONTAINER_MULTIHASHMAPOPTION_MULTIPLE, GNUNET_CONTAINER_multipeermap_get_multiple(), GNUNET_CONTAINER_multipeermap_put(), GNUNET_CONTAINER_multipeermap_size(), GNUNET_memdup, GNUNET_new, GNUNET_NO, GNUNET_NT_scanner_get_type(), GNUNET_SCHEDULER_add_now(), GNUNET_STATISTICS_set(), GNUNET_TIME_relative_to_absolute(), SenderAddress::hn, SenderAddress::nt, reschedule_sender_timeout(), SearchContext::sender, UdpHandshakeSignature::sender, SenderAddress::target, and SenderAddress::timeout.

Referenced by sock_read().

{
  struct SenderAddress *sender;
  struct SearchContext sc = { .address = address,
                              .address_len = address_len,
                              .sender = NULL };

  GNUNET_CONTAINER_multipeermap_get_multiple (senders,
                                              target,
                                              &find_sender_by_address,
                                              &sc);
  if (NULL != sc.sender)
  {
    reschedule_sender_timeout (sc.sender);
    return sc.sender;
  }
  sender = GNUNET_new (struct SenderAddress);
  sender->target = *target;
  sender->address = GNUNET_memdup (address, address_len);
  sender->address_len = address_len;
  (void) GNUNET_CONTAINER_multipeermap_put (
    senders,
    &sender->target,
    sender,
    GNUNET_CONTAINER_MULTIHASHMAPOPTION_MULTIPLE);
  GNUNET_STATISTICS_set (stats,
                         "# senders active",
                         GNUNET_CONTAINER_multipeermap_size (receivers),
                         GNUNET_NO);
  sender->timeout =
    GNUNET_TIME_relative_to_absolute (GNUNET_CONSTANTS_IDLE_CONNECTION_TIMEOUT);
  sender->hn = GNUNET_CONTAINER_heap_insert (senders_heap,
                                             sender,
                                             sender->timeout.abs_value_us);
  sender->nt = GNUNET_NT_scanner_get_type (is, address, address_len);
  if (NULL == timeout_task)
    timeout_task = GNUNET_SCHEDULER_add_now (&check_timeouts, NULL);
  return sender;
}

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verify_confirmation()

static int verify_confirmation ( const struct GNUNET_CRYPTO_EcdhePublicKey *  ephemeral, const struct UDPConfirmation *  uc  )

static

Check signature from uc against ephemeral.

Parameters

ephermal	key that is signed
uc	signature of claimant

Returns

GNUNET_OK if signature is valid

Definition at line 1562 of file gnunet-communicator-udp.c.

References UdpHandshakeSignature::ephemeral, GNUNET_CRYPTO_eddsa_verify, GNUNET_SIGNATURE_COMMUNICATOR_UDP_HANDSHAKE, UDPConfirmation::monotonic_time, UdpHandshakeSignature::monotonic_time, my_identity, GNUNET_PeerIdentity::public_key, GNUNET_CRYPTO_EccSignaturePurpose::purpose, UdpHandshakeSignature::purpose, UdpHandshakeSignature::receiver, UDPConfirmation::sender, UdpHandshakeSignature::sender, UDPConfirmation::sender_sig, and GNUNET_CRYPTO_EccSignaturePurpose::size.

Referenced by sock_read().

{
  struct UdpHandshakeSignature uhs;

  uhs.purpose.purpose = htonl (GNUNET_SIGNATURE_COMMUNICATOR_UDP_HANDSHAKE);
  uhs.purpose.size = htonl (sizeof(uhs));
  uhs.sender = uc->sender;
  uhs.receiver = my_identity;
  uhs.ephemeral = *ephemeral;
  uhs.monotonic_time = uc->monotonic_time;
  return GNUNET_CRYPTO_eddsa_verify (
    GNUNET_SIGNATURE_COMMUNICATOR_UDP_HANDSHAKE,
    &uhs,
    &uc->sender_sig,
    &uc->sender.public_key);
}

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sockaddr_to_udpaddr_string()

static char* sockaddr_to_udpaddr_string ( const struct sockaddr *  address, socklen_t  address_len  )

static

Converts address to the address string format used by this communicator in HELLOs.

Parameters

address	the address to convert, must be AF_INET or AF_INET6.
address_len	number of bytes in address

Returns

string representation of address

Definition at line 1590 of file gnunet-communicator-udp.c.

References COMMUNICATOR_ADDRESS_PREFIX, GNUNET_a2s(), GNUNET_asprintf(), GNUNET_assert, and ret.

Referenced by mq_init(), and sock_read().

{
  char *ret;

  switch (address->sa_family)
  {
  case AF_INET:
    GNUNET_asprintf (&ret,
                     "%s-%s",
                     COMMUNICATOR_ADDRESS_PREFIX,
                     GNUNET_a2s (address, address_len));
    break;

  case AF_INET6:
    GNUNET_asprintf (&ret,
                     "%s-%s",
                     COMMUNICATOR_ADDRESS_PREFIX,
                     GNUNET_a2s (address, address_len));
    break;

  default:
    GNUNET_assert (0);
  }
  return ret;
}

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sock_read()

static void sock_read ( void *  cls )

static

Socket read task.

Parameters

cls

NULL

Definition at line 1624 of file gnunet-communicator-udp.c.

References buf, calculate_cmac(), consider_ss_ack(), decrypt_box(), InitialKX::ephemeral, InitialKX::gcm_tag, GNUNET_break_op, GNUNET_CONTAINER_DLL_insert, GNUNET_CONTAINER_multishortmap_get(), GNUNET_CRYPTO_eddsa_verify, GNUNET_CRYPTO_hash(), GNUNET_ERROR_TYPE_DEBUG, GNUNET_free, GNUNET_log, GNUNET_log_strerror, GNUNET_NETWORK_socket_recvfrom(), GNUNET_NO, GNUNET_NT_scanner_get_type(), GNUNET_OK, GNUNET_SCHEDULER_add_read_net(), GNUNET_SIGNATURE_COMMUNICATOR_UDP_BROADCAST, GNUNET_STATISTICS_update(), GNUNET_TIME_UNIT_FOREVER_REL, GNUNET_TRANSPORT_application_validate(), UdpBroadcastSignature::h_address, UDPBox::kid, MAX_SECRETS, nt, SenderAddress::num_secrets, GNUNET_PeerIdentity::public_key, GNUNET_CRYPTO_EccSignaturePurpose::purpose, UdpBroadcastSignature::purpose, secret_destroy(), UDPConfirmation::sender, UdpBroadcastSignature::sender, SharedSecret::sender, UdpHandshakeSignature::sender, setup_sender(), setup_shared_secret_dec(), GNUNET_CRYPTO_EccSignaturePurpose::size, sockaddr_to_udpaddr_string(), SenderAddress::ss_head, SenderAddress::ss_tail, try_decrypt(), try_handle_plaintext(), uc, and verify_confirmation().

Referenced by run().

{
  struct sockaddr_storage sa;
  socklen_t salen = sizeof(sa);
  char buf[UINT16_MAX];
  ssize_t rcvd;

  (void) cls;
  read_task = GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_UNIT_FOREVER_REL,
                                             udp_sock,
                                             &sock_read,
                                             NULL);
  rcvd = GNUNET_NETWORK_socket_recvfrom (udp_sock,
                                         buf,
                                         sizeof(buf),
                                         (struct sockaddr *) &sa,
                                         &salen);
  if (-1 == rcvd)
  {
    GNUNET_log_strerror (GNUNET_ERROR_TYPE_DEBUG, "recv");
    return;
  }
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "Read %lu bytes\n", rcvd);
  /* first, see if it is a UDPBox */
  if (rcvd > sizeof(struct UDPBox))
  {
    const struct UDPBox *box;
    struct KeyCacheEntry *kce;

    box = (const struct UDPBox *) buf;
    kce = GNUNET_CONTAINER_multishortmap_get (key_cache, &box->kid);
    if (NULL != kce)
    {
      decrypt_box (box, (size_t) rcvd, kce);
      return;
    }
  }

  /* next, check if it is a broadcast */
  if (sizeof(struct UDPBroadcast) == rcvd)
  {
    const struct UDPBroadcast *ub;
    struct UdpBroadcastSignature uhs;

    ub = (const struct UDPBroadcast *) buf;
    uhs.purpose.purpose = htonl (GNUNET_SIGNATURE_COMMUNICATOR_UDP_BROADCAST);
    uhs.purpose.size = htonl (sizeof(uhs));
    uhs.sender = ub->sender;
    GNUNET_CRYPTO_hash (&sa, salen, &uhs.h_address);
    if (GNUNET_OK ==
        GNUNET_CRYPTO_eddsa_verify (GNUNET_SIGNATURE_COMMUNICATOR_UDP_BROADCAST,
                                    &uhs,
                                    &ub->sender_sig,
                                    &ub->sender.public_key))
    {
      char *addr_s;
      enum GNUNET_NetworkType nt;

      addr_s =
        sockaddr_to_udpaddr_string ((const struct sockaddr *) &sa, salen);
      GNUNET_STATISTICS_update (stats, "# broadcasts received", 1, GNUNET_NO);
      /* use our own mechanism to determine network type */
      nt =
        GNUNET_NT_scanner_get_type (is, (const struct sockaddr *) &sa, salen);
      GNUNET_TRANSPORT_application_validate (ah, &ub->sender, nt, addr_s);
      GNUNET_free (addr_s);
      return;
    }
    /* continue with KX, mostly for statistics... */
  }


  /* finally, test if it is a KX */
  if (rcvd < sizeof(struct UDPConfirmation) + sizeof(struct InitialKX))
  {
    GNUNET_STATISTICS_update (stats,
                              "# messages dropped (no kid, too small for KX)",
                              1,
                              GNUNET_NO);
    return;
  }
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "Got KX\n");
  {
    const struct InitialKX *kx;
    struct SharedSecret *ss;
    char pbuf[rcvd - sizeof(struct InitialKX)];
    const struct UDPConfirmation *uc;
    struct SenderAddress *sender;

    kx = (const struct InitialKX *) buf;
    ss = setup_shared_secret_dec (&kx->ephemeral);
    if (GNUNET_OK != try_decrypt (ss,
                                  kx->gcm_tag,
                                  0,
                                  &buf[sizeof(*kx)],
                                  sizeof(pbuf),
                                  pbuf))
    {
      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                  "Unable to decrypt tag, dropping...\n");
      GNUNET_free (ss);
      GNUNET_STATISTICS_update (
        stats,
        "# messages dropped (no kid, AEAD decryption failed)",
        1,
        GNUNET_NO);
      return;
    }
    uc = (const struct UDPConfirmation *) pbuf;
    if (GNUNET_OK != verify_confirmation (&kx->ephemeral, uc))
    {
      GNUNET_break_op (0);
      GNUNET_free (ss);
      GNUNET_STATISTICS_update (stats,
                                "# messages dropped (sender signature invalid)",
                                1,
                                GNUNET_NO);
      return;
    }
    calculate_cmac (ss);
    sender = setup_sender (&uc->sender, (const struct sockaddr *) &sa, salen);
    ss->sender = sender;
    GNUNET_CONTAINER_DLL_insert (sender->ss_head, sender->ss_tail, ss);
    sender->num_secrets++;
    GNUNET_STATISTICS_update (stats, "# Secrets active", 1, GNUNET_NO);
    GNUNET_STATISTICS_update (stats,
                              "# messages decrypted without BOX",
                              1,
                              GNUNET_NO);
    try_handle_plaintext (sender, &uc[1], sizeof(pbuf) - sizeof(*uc));
    consider_ss_ack (ss);
    if (sender->num_secrets > MAX_SECRETS)
      secret_destroy (sender->ss_tail);
  }
}

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udp_address_to_sockaddr()

static struct sockaddr* udp_address_to_sockaddr ( const char *  bindto, socklen_t *  sock_len  )

static

Convert UDP bind specification to a struct sockaddr *

Parameters

	bindto	bind specification to convert
[out]	sock_len	set to the length of the address

Returns

converted bindto specification

Definition at line 1771 of file gnunet-communicator-udp.c.

References COMMUNICATOR_CONFIG_SECTION, dummy, GNUNET_CONFIGURATION_get_value_yesno(), GNUNET_ERROR_TYPE_ERROR, GNUNET_free, GNUNET_log, GNUNET_malloc, GNUNET_memdup, GNUNET_NETWORK_test_pf(), GNUNET_NO, GNUNET_strdup, GNUNET_YES, port, and start.

Referenced by mq_init(), and run().

{
  struct sockaddr *in;
  unsigned int port;
  char dummy[2];
  char *colon;
  char *cp;

  if (1 == sscanf (bindto, "%u%1s", &port, dummy))
  {
    /* interpreting value as just a PORT number */
    if (port > UINT16_MAX)
    {
      GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                  "BINDTO specification `%s' invalid: value too large for port\n",
                  bindto);
      return NULL;
    }
    if ((GNUNET_NO == GNUNET_NETWORK_test_pf (PF_INET6)) ||
        (GNUNET_YES ==
         GNUNET_CONFIGURATION_get_value_yesno (cfg,
                                               COMMUNICATOR_CONFIG_SECTION,
                                               "DISABLE_V6")))
    {
      struct sockaddr_in *i4;

      i4 = GNUNET_malloc (sizeof(struct sockaddr_in));
      i4->sin_family = AF_INET;
      i4->sin_port = htons ((uint16_t) port);
      *sock_len = sizeof(struct sockaddr_in);
      in = (struct sockaddr *) i4;
    }
    else
    {
      struct sockaddr_in6 *i6;

      i6 = GNUNET_malloc (sizeof(struct sockaddr_in6));
      i6->sin6_family = AF_INET6;
      i6->sin6_port = htons ((uint16_t) port);
      *sock_len = sizeof(struct sockaddr_in6);
      in = (struct sockaddr *) i6;
    }
    return in;
  }
  cp = GNUNET_strdup (bindto);
  colon = strrchr (cp, ':');
  if (NULL != colon)
  {
    /* interpet value after colon as port */
    *colon = '\0';
    colon++;
    if (1 == sscanf (colon, "%u%1s", &port, dummy))
    {
      /* interpreting value as just a PORT number */
      if (port > UINT16_MAX)
      {
        GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                    "BINDTO specification `%s' invalid: value too large for port\n",
                    bindto);
        GNUNET_free (cp);
        return NULL;
      }
    }
    else
    {
      GNUNET_log (
        GNUNET_ERROR_TYPE_ERROR,
        "BINDTO specification `%s' invalid: last ':' not followed by number\n",
        bindto);
      GNUNET_free (cp);
      return NULL;
    }
  }
  else
  {
    /* interpret missing port as 0, aka pick any free one */
    port = 0;
  }
  {
    /* try IPv4 */
    struct sockaddr_in v4;
    if (1 == inet_pton (AF_INET, cp, &v4.sin_addr))
    {
      v4.sin_family = AF_INET;
      v4.sin_port = htons ((uint16_t) port);
#if HAVE_SOCKADDR_IN_SIN_LEN
      v4.sin_len = sizeof(struct sockaddr_in);
#endif
      in = GNUNET_memdup (&v4, sizeof(struct sockaddr_in));
      *sock_len = sizeof(struct sockaddr_in);
      GNUNET_free (cp);
      return in;
    }
  }
  {
    /* try IPv6 */
    struct sockaddr_in6 v6;
    const char *start;

    start = cp;
    if (('[' == *cp) && (']' == cp[strlen (cp) - 1]))
    {
      start++;   /* skip over '[' */
      cp[strlen (cp) - 1] = '\0';  /* eat ']' */
    }
    if (1 == inet_pton (AF_INET6, start, &v6.sin6_addr))
    {
      v6.sin6_family = AF_INET6;
      v6.sin6_port = htons ((uint16_t) port);
#if HAVE_SOCKADDR_IN_SIN_LEN
      v6.sin6_len = sizeof(sizeof(struct sockaddr_in6));
#endif
      in = GNUNET_memdup (&v6, sizeof(v6));
      *sock_len = sizeof(v6);
      GNUNET_free (cp);
      return in;
    }
  }
  /* #5528 FIXME (feature!): maybe also try getnameinfo()? */
  GNUNET_free (cp);
  return NULL;
}

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do_pad()

static void do_pad ( gcry_cipher_hd_t  out_cipher, char *  dgram, size_t  pad_size  )

static

Pad dgram by pad_size using out_cipher.

Parameters

out_cipher	cipher to use
dgram	datagram to pad
pad_size	number of bytes of padding to append

Definition at line 1903 of file gnunet-communicator-udp.c.

References GNUNET_assert, GNUNET_CRYPTO_QUALITY_WEAK, GNUNET_CRYPTO_random_block(), GNUNET_MESSAGE_TYPE_COMMUNICATOR_UDP_PAD, and GNUNET_MessageHeader::size.

Referenced by mq_send_d(), and mq_send_kx().

{
  char pad[pad_size];

  GNUNET_CRYPTO_random_block (GNUNET_CRYPTO_QUALITY_WEAK, pad, sizeof(pad));
  if (sizeof(pad) > sizeof(struct GNUNET_MessageHeader))
  {
    struct GNUNET_MessageHeader hdr =
    { .size = htons (sizeof(pad)),
      .type = htons (GNUNET_MESSAGE_TYPE_COMMUNICATOR_UDP_PAD) };

    memcpy (pad, &hdr, sizeof(hdr));
  }
  GNUNET_assert (
    0 ==
    gcry_cipher_encrypt (out_cipher, dgram, sizeof(pad), pad, sizeof(pad)));
}

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mq_send_kx()

static void mq_send_kx ( struct GNUNET_MQ_Handle *  mq, const struct GNUNET_MessageHeader *  msg, void *  impl_state  )

static

Signature of functions implementing the sending functionality of a message queue.

Parameters

mq	the message queue
msg	the message to send
impl_state	our struct ReceiverAddress

Definition at line 1931 of file gnunet-communicator-udp.c.

References ReceiverAddress::address, ReceiverAddress::address_len, do_pad(), UdpHandshakeSignature::ephemeral, InitialKX::ephemeral, InitialKX::gcm_tag, GNUNET_a2s(), GNUNET_assert, GNUNET_break, GNUNET_CRYPTO_ecdhe_key_create(), GNUNET_CRYPTO_ecdhe_key_get_public(), GNUNET_CRYPTO_eddsa_sign, GNUNET_ERROR_TYPE_DEBUG, GNUNET_ERROR_TYPE_WARNING, GNUNET_log, GNUNET_log_strerror, GNUNET_MQ_impl_send_continue(), GNUNET_NETWORK_socket_sendto(), GNUNET_SIGNATURE_COMMUNICATOR_UDP_HANDSHAKE, GNUNET_TIME_absolute_get_monotonic(), GNUNET_TIME_absolute_hton(), ReceiverAddress::kx_mq, ReceiverAddress::kx_mtu, SharedSecret::master, UDPConfirmation::monotonic_time, UdpHandshakeSignature::monotonic_time, my_identity, GNUNET_CRYPTO_EccSignaturePurpose::purpose, UdpHandshakeSignature::purpose, UdpHandshakeSignature::receiver, receiver_destroy(), reschedule_receiver_timeout(), UDPConfirmation::sender, UdpHandshakeSignature::sender, UDPConfirmation::sender_sig, setup_cipher(), setup_shared_secret_enc(), GNUNET_CRYPTO_EccSignaturePurpose::size, GNUNET_MessageHeader::size, ReceiverAddress::target, and uc.

Referenced by setup_receiver_mq().

{
  struct ReceiverAddress *receiver = impl_state;
  uint16_t msize = ntohs (msg->size);
  struct UdpHandshakeSignature uhs;
  struct UDPConfirmation uc;
  struct InitialKX kx;
  struct GNUNET_CRYPTO_EcdhePrivateKey epriv;
  char dgram[receiver->kx_mtu + sizeof(uc) + sizeof(kx)];
  size_t dpos;
  gcry_cipher_hd_t out_cipher;
  struct SharedSecret *ss;


  GNUNET_assert (mq == receiver->kx_mq);
  if (msize > receiver->kx_mtu)
  {
    GNUNET_break (0);
    receiver_destroy (receiver);
    return;
  }
  reschedule_receiver_timeout (receiver);

  /* setup key material */
  GNUNET_CRYPTO_ecdhe_key_create (&epriv);

  ss = setup_shared_secret_enc (&epriv, receiver);
  setup_cipher (&ss->master, 0, &out_cipher);
  /* compute 'uc' */
  uc.sender = my_identity;
  uc.monotonic_time =
    GNUNET_TIME_absolute_hton (GNUNET_TIME_absolute_get_monotonic (cfg));
  uhs.purpose.purpose = htonl (GNUNET_SIGNATURE_COMMUNICATOR_UDP_HANDSHAKE);
  uhs.purpose.size = htonl (sizeof(uhs));
  uhs.sender = my_identity;
  uhs.receiver = receiver->target;
  GNUNET_CRYPTO_ecdhe_key_get_public (&epriv, &uhs.ephemeral);
  uhs.monotonic_time = uc.monotonic_time;
  GNUNET_CRYPTO_eddsa_sign (my_private_key,
                            &uhs,
                            &uc.sender_sig);
  /* Leave space for kx */
  dpos = sizeof(kx);
  /* Append encrypted uc to dgram */
  GNUNET_assert (0 == gcry_cipher_encrypt (out_cipher,
                                           &dgram[dpos],
                                           sizeof(uc),
                                           &uc,
                                           sizeof(uc)));
  dpos += sizeof(uc);
  /* Append encrypted payload to dgram */
  GNUNET_assert (
    0 == gcry_cipher_encrypt (out_cipher, &dgram[dpos], msize, msg, msize));
  dpos += msize;
  do_pad (out_cipher, &dgram[dpos], sizeof(dgram) - dpos);
  /* Datagram starts with kx */
  kx.ephemeral = uhs.ephemeral;
  GNUNET_assert (
    0 == gcry_cipher_gettag (out_cipher, kx.gcm_tag, sizeof(kx.gcm_tag)));
  gcry_cipher_close (out_cipher);
  memcpy (dgram, &kx, sizeof(kx));
  if (-1 == GNUNET_NETWORK_socket_sendto (udp_sock,
                                          dgram,
                                          sizeof(dgram),
                                          receiver->address,
                                          receiver->address_len))
    GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "send");
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "Sending KX to %s\n", GNUNET_a2s (receiver->address,
                                                receiver->address_len));
  GNUNET_MQ_impl_send_continue (mq);
}

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mq_send_d()

static void mq_send_d ( struct GNUNET_MQ_Handle *  mq, const struct GNUNET_MessageHeader *  msg, void *  impl_state  )

static

Signature of functions implementing the sending functionality of a message queue.

Parameters

mq	the message queue
msg	the message to send
impl_state	our struct ReceiverAddress

Definition at line 2016 of file gnunet-communicator-udp.c.

References ReceiverAddress::acks_available, ReceiverAddress::d_mq, ReceiverAddress::d_mtu, do_pad(), UDPBox::gcm_tag, get_kid(), GNUNET_assert, GNUNET_break, GNUNET_ERROR_TYPE_DEBUG, GNUNET_ERROR_TYPE_WARNING, GNUNET_log, GNUNET_log_strerror, GNUNET_MQ_impl_send_continue(), GNUNET_NETWORK_socket_sendto(), UDPBox::kid, SharedSecret::prev, receiver_destroy(), reschedule_receiver_timeout(), setup_cipher(), GNUNET_MessageHeader::size, and ReceiverAddress::ss_tail.

Referenced by setup_receiver_mq().

{
  struct ReceiverAddress *receiver = impl_state;
  uint16_t msize = ntohs (msg->size);

  GNUNET_assert (mq == receiver->d_mq);
  if ((msize > receiver->d_mtu) ||
      (0 == receiver->acks_available))
  {
    GNUNET_break (0);
    receiver_destroy (receiver);
    return;
  }
  reschedule_receiver_timeout (receiver);

  /* begin "BOX" encryption method, scan for ACKs from tail! */
  for (struct SharedSecret *ss = receiver->ss_tail; NULL != ss; ss = ss->prev)
  {
    if (ss->sequence_used >= ss->sequence_allowed)
    {
      continue;
    }
    char dgram[sizeof(struct UDPBox) + receiver->d_mtu];
    struct UDPBox *box;
    gcry_cipher_hd_t out_cipher;
    size_t dpos;

    box = (struct UDPBox *) dgram;
    ss->sequence_used++;
    get_kid (&ss->master, ss->sequence_used, &box->kid);
    setup_cipher (&ss->master, ss->sequence_used, &out_cipher);
    /* Append encrypted payload to dgram */
    dpos = sizeof(struct UDPBox);
    GNUNET_assert (
      0 == gcry_cipher_encrypt (out_cipher, &dgram[dpos], msize, msg, msize));
    dpos += msize;
    do_pad (out_cipher, &dgram[dpos], sizeof(dgram) - dpos);
    GNUNET_assert (0 == gcry_cipher_gettag (out_cipher,
                                            box->gcm_tag,
                                            sizeof(box->gcm_tag)));
    gcry_cipher_close (out_cipher);
    if (-1 == GNUNET_NETWORK_socket_sendto (udp_sock,
                                            dgram,
                                            sizeof(dgram),
                                            receiver->address,
                                            receiver->address_len))
      GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "send");
    GNUNET_MQ_impl_send_continue (mq);
    receiver->acks_available--;
    if (0 == receiver->acks_available)
    {
      /* We have no more ACKs */
      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                  "No more acks\n");
    }
    return;
  }
}

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mq_destroy_d()

static void mq_destroy_d ( struct GNUNET_MQ_Handle *  mq, void *  impl_state  )

static

Signature of functions implementing the destruction of a message queue.

Implementations must not free mq, but should take care of impl_state.

Parameters

mq	the message queue to destroy
impl_state	our struct ReceiverAddress

Definition at line 2087 of file gnunet-communicator-udp.c.

References ReceiverAddress::d_mq, GNUNET_ERROR_TYPE_DEBUG, GNUNET_log, and receiver_destroy().

Referenced by setup_receiver_mq().

{
  struct ReceiverAddress *receiver = impl_state;
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "Default MQ destroyed\n");
  if (mq == receiver->d_mq)
  {
    receiver->d_mq = NULL;
    receiver_destroy (receiver);
  }
}

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mq_destroy_kx()

static void mq_destroy_kx ( struct GNUNET_MQ_Handle *  mq, void *  impl_state  )

static

Signature of functions implementing the destruction of a message queue.

Implementations must not free mq, but should take care of impl_state.

Parameters

mq	the message queue to destroy
impl_state	our struct ReceiverAddress

Definition at line 2109 of file gnunet-communicator-udp.c.

References GNUNET_ERROR_TYPE_DEBUG, GNUNET_log, ReceiverAddress::kx_mq, and receiver_destroy().

Referenced by setup_receiver_mq().

{
  struct ReceiverAddress *receiver = impl_state;
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "KX MQ destroyed\n");
  if (mq == receiver->kx_mq)
  {
    receiver->kx_mq = NULL;
    receiver_destroy (receiver);
  }
}

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mq_cancel()

static void mq_cancel ( struct GNUNET_MQ_Handle *  mq, void *  impl_state  )

static

Implementation function that cancels the currently sent message.

Parameters

mq	message queue
impl_state	our struct RecvierAddress

Definition at line 2129 of file gnunet-communicator-udp.c.

References GNUNET_assert.

Referenced by setup_receiver_mq().

{
  /* Cancellation is impossible with UDP; bail */
  GNUNET_assert (0);
}

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mq_error()

static void mq_error ( void *  cls, enum GNUNET_MQ_Error  error  )

static

Generic error handler, called with the appropriate error code and the same closure specified at the creation of the message queue.

Not every message queue implementation supports an error handler.

Parameters

cls	our struct ReceiverAddress
error	error code

Definition at line 2146 of file gnunet-communicator-udp.c.

References GNUNET_ERROR_TYPE_ERROR, GNUNET_i2s(), GNUNET_log, receiver_destroy(), and ReceiverAddress::target.

Referenced by setup_receiver_mq().

{
  struct ReceiverAddress *receiver = cls;

  GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
              "MQ error in queue to %s: %d\n",
              GNUNET_i2s (&receiver->target),
              (int) error);
  receiver_destroy (receiver);
}

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mq_init()

static int mq_init ( void *  cls, const struct GNUNET_PeerIdentity *  peer, const char *  address  )

static

Function called by the transport service to initialize a message queue given address information about another peer.

If and when the communication channel is established, the communicator must call GNUNET_TRANSPORT_communicator_mq_add() to notify the service that the channel is now up. It is the responsibility of the communicator to manage sane retries and timeouts for any peer/address combination provided by the transport service. Timeouts and retries do not need to be signalled to the transport service.

Parameters

cls	closure
peer	identity of the other peer
address	where to send the message, human-readable communicator-specific format, 0-terminated, UTF-8

Returns

GNUNET_OK on success, GNUNET_SYSERR if the provided address is invalid

Definition at line 2269 of file gnunet-communicator-udp.c.

References GNUNET_TIME_Absolute::abs_value_us, ReceiverAddress::address, ReceiverAddress::address_len, check_timeouts(), COMMUNICATOR_ADDRESS_PREFIX, ReceiverAddress::foreign_addr, GNUNET_break_op, GNUNET_CONSTANTS_IDLE_CONNECTION_TIMEOUT, GNUNET_CONTAINER_heap_insert(), GNUNET_CONTAINER_MULTIHASHMAPOPTION_MULTIPLE, GNUNET_CONTAINER_multipeermap_put(), GNUNET_CONTAINER_multipeermap_size(), GNUNET_ERROR_TYPE_DEBUG, GNUNET_i2s_full(), GNUNET_log, GNUNET_new, GNUNET_NO, GNUNET_NT_scanner_get_type(), GNUNET_OK, GNUNET_SCHEDULER_add_now(), GNUNET_STATISTICS_set(), GNUNET_SYSERR, GNUNET_TIME_relative_to_absolute(), ReceiverAddress::hn, ReceiverAddress::nt, peer, UdpHandshakeSignature::receiver, setup_receiver_mq(), sockaddr_to_udpaddr_string(), ReceiverAddress::target, ReceiverAddress::timeout, and udp_address_to_sockaddr().

Referenced by run().

{
  struct ReceiverAddress *receiver;
  const char *path;
  struct sockaddr *in;
  socklen_t in_len;

  if (0 != strncmp (address,
                    COMMUNICATOR_ADDRESS_PREFIX "-",
                    strlen (COMMUNICATOR_ADDRESS_PREFIX "-")))
  {
    GNUNET_break_op (0);
    return GNUNET_SYSERR;
  }
  path = &address[strlen (COMMUNICATOR_ADDRESS_PREFIX "-")];
  in = udp_address_to_sockaddr (path, &in_len);

  receiver = GNUNET_new (struct ReceiverAddress);
  receiver->address = in;
  receiver->address_len = in_len;
  receiver->target = *peer;
  receiver->nt = GNUNET_NT_scanner_get_type (is, in, in_len);
  (void) GNUNET_CONTAINER_multipeermap_put (
    receivers,
    &receiver->target,
    receiver,
    GNUNET_CONTAINER_MULTIHASHMAPOPTION_MULTIPLE);
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "Added %s to receivers\n",
              GNUNET_i2s_full (&receiver->target));
  receiver->timeout =
    GNUNET_TIME_relative_to_absolute (GNUNET_CONSTANTS_IDLE_CONNECTION_TIMEOUT);
  receiver->hn = GNUNET_CONTAINER_heap_insert (receivers_heap,
                                               receiver,
                                               receiver->timeout.abs_value_us);
  GNUNET_STATISTICS_set (stats,
                         "# receivers active",
                         GNUNET_CONTAINER_multipeermap_size (receivers),
                         GNUNET_NO);
  receiver->foreign_addr =
    sockaddr_to_udpaddr_string (receiver->address, receiver->address_len);
  setup_receiver_mq (receiver);
  if (NULL == timeout_task)
    timeout_task = GNUNET_SCHEDULER_add_now (&check_timeouts, NULL);
  return GNUNET_OK;
}

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get_receiver_delete_it()

static int get_receiver_delete_it ( void *  cls, const struct GNUNET_PeerIdentity *  target, void *  value  )

static

Iterator over all receivers to clean up.

Parameters

cls	NULL
target	unused
value	the queue to destroy

Returns

GNUNET_OK to continue to iterate

Definition at line 2326 of file gnunet-communicator-udp.c.

References GNUNET_OK, receiver_destroy(), and value.

Referenced by do_shutdown().

{
  struct ReceiverAddress *receiver = value;

  (void) cls;
  (void) target;
  receiver_destroy (receiver);
  return GNUNET_OK;
}

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get_sender_delete_it()

static int get_sender_delete_it ( void *  cls, const struct GNUNET_PeerIdentity *  target, void *  value  )

static

Iterator over all senders to clean up.

Parameters

cls	NULL
target	unused
value	the queue to destroy

Returns

GNUNET_OK to continue to iterate

Definition at line 2348 of file gnunet-communicator-udp.c.

References GNUNET_OK, UdpHandshakeSignature::sender, sender_destroy(), and value.

Referenced by do_shutdown().

{
  struct SenderAddress *sender = value;

  (void) cls;
  (void) target;
  sender_destroy (sender);
  return GNUNET_OK;
}

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do_shutdown()

static void do_shutdown ( void *  cls )

static

Shutdown the UNIX communicator.

Parameters

cls	NULL (always)

Definition at line 2367 of file gnunet-communicator-udp.c.

References bi_destroy(), get_receiver_delete_it(), get_sender_delete_it(), GNUNET_break, GNUNET_CONTAINER_heap_destroy(), GNUNET_CONTAINER_multipeermap_destroy(), GNUNET_CONTAINER_multipeermap_iterate(), GNUNET_CONTAINER_multishortmap_destroy(), GNUNET_free, GNUNET_NAT_unregister(), GNUNET_NETWORK_socket_close(), GNUNET_NO, GNUNET_NT_scanner_done(), GNUNET_OK, GNUNET_SCHEDULER_cancel(), GNUNET_STATISTICS_destroy(), GNUNET_TRANSPORT_application_done(), and GNUNET_TRANSPORT_communicator_disconnect().

Referenced by run().

{
  if (NULL != nat)
  {
    GNUNET_NAT_unregister (nat);
    nat = NULL;
  }
  while (NULL != bi_head)
    bi_destroy (bi_head);
  if (NULL != broadcast_task)
  {
    GNUNET_SCHEDULER_cancel (broadcast_task);
    broadcast_task = NULL;
  }
  if (NULL != read_task)
  {
    GNUNET_SCHEDULER_cancel (read_task);
    read_task = NULL;
  }
  if (NULL != udp_sock)
  {
    GNUNET_break (GNUNET_OK == GNUNET_NETWORK_socket_close (udp_sock));
    udp_sock = NULL;
  }
  GNUNET_CONTAINER_multipeermap_iterate (receivers,
                                         &get_receiver_delete_it,
                                         NULL);
  GNUNET_CONTAINER_multipeermap_destroy (receivers);
  GNUNET_CONTAINER_multipeermap_iterate (senders, &get_sender_delete_it, NULL);
  GNUNET_CONTAINER_multipeermap_destroy (senders);
  GNUNET_CONTAINER_multishortmap_destroy (key_cache);
  GNUNET_CONTAINER_heap_destroy (senders_heap);
  GNUNET_CONTAINER_heap_destroy (receivers_heap);
  if (NULL != ch)
  {
    GNUNET_TRANSPORT_communicator_disconnect (ch);
    ch = NULL;
  }
  if (NULL != ah)
  {
    GNUNET_TRANSPORT_application_done (ah);
    ah = NULL;
  }
  if (NULL != stats)
  {
    GNUNET_STATISTICS_destroy (stats, GNUNET_NO);
    stats = NULL;
  }
  if (NULL != my_private_key)
  {
    GNUNET_free (my_private_key);
    my_private_key = NULL;
  }
  if (NULL != is)
  {
    GNUNET_NT_scanner_done (is);
    is = NULL;
  }
}

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enc_notify_cb()

static void enc_notify_cb ( void *  cls, const struct GNUNET_PeerIdentity *  sender, const struct GNUNET_MessageHeader *  msg  )

static

Function called when the transport service has received a backchannel message for this communicator (!) via a different return path.

Should be an acknowledgement.

Parameters

cls	closure, NULL
sender	which peer sent the notification
msg	payload

Definition at line 2438 of file gnunet-communicator-udp.c.

References GNUNET_break_op, GNUNET_CONTAINER_multipeermap_get_multiple(), GNUNET_ERROR_TYPE_DEBUG, GNUNET_i2s_full(), GNUNET_log, GNUNET_MESSAGE_TYPE_COMMUNICATOR_UDP_ACK, handle_ack(), GNUNET_MessageHeader::size, and GNUNET_MessageHeader::type.

Referenced by run().

{
  const struct UDPAck *ack;

  (void) cls;
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "Storing UDPAck received from backchannel from %s\n",
              GNUNET_i2s_full (sender));
  if ((ntohs (msg->type) != GNUNET_MESSAGE_TYPE_COMMUNICATOR_UDP_ACK) ||
      (ntohs (msg->size) != sizeof(struct UDPAck)))
  {
    GNUNET_break_op (0);
    return;
  }
  ack = (const struct UDPAck *) msg;
  GNUNET_CONTAINER_multipeermap_get_multiple (receivers,
                                              sender,
                                              &handle_ack,
                                              (void *) ack);
}

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nat_address_cb()

static void nat_address_cb ( void *  cls, void **  app_ctx, int  add_remove, enum GNUNET_NAT_AddressClass  ac, const struct sockaddr *  addr, socklen_t  addrlen  )

static

Signature of the callback passed to GNUNET_NAT_register() for a function to call whenever our set of 'valid' addresses changes.

Parameters

cls	closure
app_ctx[in,out]	location where the app can store stuff on add and retrieve it on remove
add_remove	GNUNET_YES to add a new public IP address, GNUNET_NO to remove a previous (now invalid) one
ac	address class the address belongs to
addr	either the previous or the new public IP address
addrlen	actual length of the addr

Definition at line 2476 of file gnunet-communicator-udp.c.

References ai, COMMUNICATOR_ADDRESS_PREFIX, GNUNET_a2s(), GNUNET_asprintf(), GNUNET_free, GNUNET_NT_scanner_get_type(), GNUNET_TIME_UNIT_FOREVER_REL, GNUNET_TRANSPORT_communicator_address_add(), GNUNET_TRANSPORT_communicator_address_remove(), GNUNET_YES, and nt.

Referenced by run().

{
  char *my_addr;
  struct GNUNET_TRANSPORT_AddressIdentifier *ai;

  if (GNUNET_YES == add_remove)
  {
    enum GNUNET_NetworkType nt;

    GNUNET_asprintf (&my_addr,
                     "%s-%s",
                     COMMUNICATOR_ADDRESS_PREFIX,
                     GNUNET_a2s (addr, addrlen));
    nt = GNUNET_NT_scanner_get_type (is, addr, addrlen);
    ai =
      GNUNET_TRANSPORT_communicator_address_add (ch,
                                                 my_addr,
                                                 nt,
                                                 GNUNET_TIME_UNIT_FOREVER_REL);
    GNUNET_free (my_addr);
    *app_ctx = ai;
  }
  else
  {
    ai = *app_ctx;
    GNUNET_TRANSPORT_communicator_address_remove (ai);
    *app_ctx = NULL;
  }
}

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ifc_broadcast()

static void ifc_broadcast ( void *  cls )

static

Broadcast our presence on one of our interfaces.

Parameters

cls	a struct BroadcastInterface

Definition at line 2518 of file gnunet-communicator-udp.c.

References BroadcastInterface::ba, BroadcastInterface::bcm, BROADCAST_FREQUENCY, BroadcastInterface::broadcast_task, GNUNET_break, GNUNET_CRYPTO_QUALITY_WEAK, GNUNET_CRYPTO_random_u64(), GNUNET_ERROR_TYPE_WARNING, GNUNET_log_strerror, GNUNET_NETWORK_socket_sendto(), GNUNET_NETWORK_socket_setsockopt(), GNUNET_OK, GNUNET_SCHEDULER_add_delayed(), INTERFACE_SCAN_FREQUENCY, BroadcastInterface::mcreq, my_port, BroadcastInterface::sa, and BroadcastInterface::salen.

Referenced by iface_proc().

{
  struct BroadcastInterface *bi = cls;
  struct GNUNET_TIME_Relative delay;

  delay = BROADCAST_FREQUENCY;
  delay.rel_value_us =
    GNUNET_CRYPTO_random_u64 (GNUNET_CRYPTO_QUALITY_WEAK, delay.rel_value_us);
  bi->broadcast_task =
    GNUNET_SCHEDULER_add_delayed (INTERFACE_SCAN_FREQUENCY, &ifc_broadcast, bi);

  switch (bi->sa->sa_family)
  {
  case AF_INET: {
      static int yes = 1;
      static int no = 0;
      ssize_t sent;

      if (GNUNET_OK != GNUNET_NETWORK_socket_setsockopt (udp_sock,
                                                         SOL_SOCKET,
                                                         SO_BROADCAST,
                                                         &yes,
                                                         sizeof(int)))
        GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "setsockopt");
      sent = GNUNET_NETWORK_socket_sendto (udp_sock,
                                           &bi->bcm,
                                           sizeof(bi->bcm),
                                           bi->ba,
                                           bi->salen);
      if (-1 == sent)
        GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "sendto");
      if (GNUNET_OK != GNUNET_NETWORK_socket_setsockopt (udp_sock,
                                                         SOL_SOCKET,
                                                         SO_BROADCAST,
                                                         &no,
                                                         sizeof(int)))
        GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "setsockopt");
      break;
    }

  case AF_INET6: {
      ssize_t sent;
      struct sockaddr_in6 dst;

      dst.sin6_family = AF_INET6;
      dst.sin6_port = htons (my_port);
      dst.sin6_addr = bi->mcreq.ipv6mr_multiaddr;
      dst.sin6_scope_id = ((struct sockaddr_in6 *) bi->ba)->sin6_scope_id;

      sent = GNUNET_NETWORK_socket_sendto (udp_sock,
                                           &bi->bcm,
                                           sizeof(bi->bcm),
                                           (const struct sockaddr *) &dst,
                                           sizeof(dst));
      if (-1 == sent)
        GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "sendto");
      break;
    }

  default:
    GNUNET_break (0);
    break;
  }
}

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iface_proc()

static int iface_proc ( void *  cls, const char *  name, int  isDefault, const struct sockaddr *  addr, const struct sockaddr *  broadcast_addr, const struct sockaddr *  netmask, socklen_t  addrlen  )

static

Callback function invoked for each interface found.

Activates/deactivates broadcast interfaces.

Parameters

cls	NULL
name	name of the interface (can be NULL for unknown)
isDefault	is this presumably the default interface
addr	address of this interface (can be NULL for unknown or unassigned)
broadcast_addr	the broadcast address (can be NULL for unknown or unassigned)
netmask	the network mask (can be NULL for unknown or unassigned)
addrlen	length of the address

Returns

GNUNET_OK to continue iteration, GNUNET_SYSERR to abort

Definition at line 2599 of file gnunet-communicator-udp.c.

References BroadcastInterface::ba, BroadcastInterface::bcm, BroadcastInterface::broadcast_task, BroadcastInterface::found, GNUNET_assert, GNUNET_CONTAINER_DLL_insert, GNUNET_CRYPTO_eddsa_sign, GNUNET_CRYPTO_hash(), GNUNET_ERROR_TYPE_WARNING, GNUNET_log_strerror, GNUNET_memdup, GNUNET_NETWORK_socket_setsockopt(), GNUNET_new, GNUNET_NT_LOOPBACK, GNUNET_NT_scanner_get_type(), GNUNET_OK, GNUNET_SCHEDULER_add_now(), GNUNET_SIGNATURE_COMMUNICATOR_UDP_BROADCAST, GNUNET_YES, UdpBroadcastSignature::h_address, have_v6_socket, ifc_broadcast(), BroadcastInterface::mcreq, my_identity, BroadcastInterface::next, GNUNET_CRYPTO_EccSignaturePurpose::purpose, UdpBroadcastSignature::purpose, BroadcastInterface::sa, BroadcastInterface::salen, UDPBroadcast::sender, UdpBroadcastSignature::sender, UDPBroadcast::sender_sig, and GNUNET_CRYPTO_EccSignaturePurpose::size.

Referenced by do_broadcast().

{
  struct BroadcastInterface *bi;
  enum GNUNET_NetworkType network;
  struct UdpBroadcastSignature ubs;

  (void) cls;
  (void) netmask;
  if (NULL == addr)
    return GNUNET_YES; /* need to know our address! */
  network = GNUNET_NT_scanner_get_type (is, addr, addrlen);
  if (GNUNET_NT_LOOPBACK == network)
  {
    /* Broadcasting on loopback does not make sense */
    return GNUNET_YES;
  }
  for (bi = bi_head; NULL != bi; bi = bi->next)
  {
    if ((bi->salen == addrlen) && (0 == memcmp (addr, bi->sa, addrlen)))
    {
      bi->found = GNUNET_YES;
      return GNUNET_OK;
    }
  }

  if ((AF_INET6 == addr->sa_family) && (NULL == broadcast_addr))
    return GNUNET_OK; /* broadcast_addr is required for IPv6! */
  if ((AF_INET6 == addr->sa_family) && (GNUNET_YES != have_v6_socket))
    return GNUNET_OK; /* not using IPv6 */

  bi = GNUNET_new (struct BroadcastInterface);
  bi->sa = GNUNET_memdup (addr, addrlen);
  if (NULL != broadcast_addr)
    bi->ba = GNUNET_memdup (broadcast_addr, addrlen);
  bi->salen = addrlen;
  bi->found = GNUNET_YES;
  bi->bcm.sender = my_identity;
  ubs.purpose.purpose = htonl (GNUNET_SIGNATURE_COMMUNICATOR_UDP_BROADCAST);
  ubs.purpose.size = htonl (sizeof(ubs));
  ubs.sender = my_identity;
  GNUNET_CRYPTO_hash (addr, addrlen, &ubs.h_address);
  GNUNET_CRYPTO_eddsa_sign (my_private_key,
                            &ubs,
                            &bi->bcm.sender_sig);
  if (NULL != broadcast_addr)
  {
    bi->broadcast_task = GNUNET_SCHEDULER_add_now (&ifc_broadcast, bi);
    GNUNET_CONTAINER_DLL_insert (bi_head, bi_tail, bi);
  }
  if ((AF_INET6 == addr->sa_family) && (NULL != broadcast_addr))
  {
    /* Create IPv6 multicast request */
    const struct sockaddr_in6 *s6 =
      (const struct sockaddr_in6 *) broadcast_addr;

    GNUNET_assert (
      1 == inet_pton (AF_INET6, "FF05::13B", &bi->mcreq.ipv6mr_multiaddr));

    /* http://tools.ietf.org/html/rfc2553#section-5.2:
     *
     * IPV6_JOIN_GROUP
     *
     * Join a multicast group on a specified local interface.  If the
     * interface index is specified as 0, the kernel chooses the local
     * interface.  For example, some kernels look up the multicast
     * group in the normal IPv6 routing table and using the resulting
     * interface; we do this for each interface, so no need to use
     * zero (anymore...).
     */bi->mcreq.ipv6mr_interface = s6->sin6_scope_id;

    /* Join the multicast group */
    if (GNUNET_OK != GNUNET_NETWORK_socket_setsockopt (udp_sock,
                                                       IPPROTO_IPV6,
                                                       IPV6_JOIN_GROUP,
                                                       &bi->mcreq,
                                                       sizeof(bi->mcreq)))
    {
      GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "setsockopt");
    }
  }
  return GNUNET_OK;
}

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do_broadcast()

static void do_broadcast ( void *  cls )

static

Scan interfaces to broadcast our presence on the LAN.

Parameters

cls	NULL, unused

Definition at line 2695 of file gnunet-communicator-udp.c.

References bi_destroy(), BroadcastInterface::found, GNUNET_NO, GNUNET_OS_network_interfaces_list(), GNUNET_SCHEDULER_add_delayed(), iface_proc(), INTERFACE_SCAN_FREQUENCY, and BroadcastInterface::next.

Referenced by run().

{
  struct BroadcastInterface *bin;

  (void) cls;
  for (struct BroadcastInterface *bi = bi_head; NULL != bi; bi = bi->next)
    bi->found = GNUNET_NO;
  GNUNET_OS_network_interfaces_list (&iface_proc, NULL);
  for (struct BroadcastInterface *bi = bi_head; NULL != bi; bi = bin)
  {
    bin = bi->next;
    if (GNUNET_NO == bi->found)
      bi_destroy (bi);
  }
  broadcast_task = GNUNET_SCHEDULER_add_delayed (INTERFACE_SCAN_FREQUENCY,
                                                 &do_broadcast,
                                                 NULL);
}

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run()

static void run ( void *  cls, char *const *  args, const char *  cfgfile, const struct GNUNET_CONFIGURATION_Handle *  c  )

static

Setup communicator and launch network interactions.

Parameters

cls	NULL (always)
args	remaining command-line arguments
cfgfile	name of the configuration file used (for saving, can be NULL!)
c	configuration

Definition at line 2724 of file gnunet-communicator-udp.c.

References _, COMMUNICATOR_ADDRESS_PREFIX, COMMUNICATOR_CONFIG_SECTION, do_broadcast(), do_shutdown(), enc_notify_cb(), GNUNET_a2s(), GNUNET_break, GNUNET_CONFIGURATION_get_value_string(), GNUNET_CONFIGURATION_get_value_yesno(), GNUNET_CONTAINER_heap_create(), GNUNET_CONTAINER_HEAP_ORDER_MIN, GNUNET_CONTAINER_multipeermap_create(), GNUNET_CONTAINER_multishortmap_create(), GNUNET_CRYPTO_eddsa_key_create_from_configuration(), GNUNET_CRYPTO_eddsa_key_get_public(), GNUNET_ERROR_TYPE_DEBUG, GNUNET_ERROR_TYPE_ERROR, GNUNET_free, GNUNET_log, GNUNET_log_config_missing(), GNUNET_log_strerror, GNUNET_log_strerror_file, GNUNET_NAT_register(), GNUNET_NETWORK_get_fd(), GNUNET_NETWORK_socket_bind(), GNUNET_NETWORK_socket_close(), GNUNET_NETWORK_socket_create(), GNUNET_NT_scanner_init(), GNUNET_OK, GNUNET_SCHEDULER_add_now(), GNUNET_SCHEDULER_add_read_net(), GNUNET_SCHEDULER_add_shutdown(), GNUNET_SCHEDULER_shutdown(), GNUNET_STATISTICS_create(), GNUNET_TIME_UNIT_FOREVER_REL, GNUNET_TRANSPORT_application_init(), GNUNET_TRANSPORT_CC_UNRELIABLE, GNUNET_TRANSPORT_communicator_connect(), GNUNET_YES, have_v6_socket, mq_init(), my_identity, my_port, nat_address_cb(), GNUNET_PeerIdentity::public_key, sock_read(), and udp_address_to_sockaddr().

Referenced by main().

{
  char *bindto;
  struct sockaddr *in;
  socklen_t in_len;
  struct sockaddr_storage in_sto;
  socklen_t sto_len;

  (void) cls;
  cfg = c;
  if (GNUNET_OK !=
      GNUNET_CONFIGURATION_get_value_string (cfg,
                                             COMMUNICATOR_CONFIG_SECTION,
                                             "BINDTO",
                                             &bindto))
  {
    GNUNET_log_config_missing (GNUNET_ERROR_TYPE_ERROR,
                               COMMUNICATOR_CONFIG_SECTION,
                               "BINDTO");
    return;
  }

  in = udp_address_to_sockaddr (bindto, &in_len);
  if (NULL == in)
  {
    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                "Failed to setup UDP socket address with path `%s'\n",
                bindto);
    GNUNET_free (bindto);
    return;
  }
  udp_sock =
    GNUNET_NETWORK_socket_create (in->sa_family, SOCK_DGRAM, IPPROTO_UDP);
  if (NULL == udp_sock)
  {
    GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR, "socket");
    GNUNET_free (in);
    GNUNET_free (bindto);
    return;
  }
  if (AF_INET6 == in->sa_family)
    have_v6_socket = GNUNET_YES;
  if (GNUNET_OK != GNUNET_NETWORK_socket_bind (udp_sock, in, in_len))
  {
    GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_ERROR, "bind", bindto);
    GNUNET_NETWORK_socket_close (udp_sock);
    udp_sock = NULL;
    GNUNET_free (in);
    GNUNET_free (bindto);
    return;
  }

  /* We might have bound to port 0, allowing the OS to figure it out;
     thus, get the real IN-address from the socket */
  sto_len = sizeof(in_sto);
  if (0 != getsockname (GNUNET_NETWORK_get_fd (udp_sock),
                        (struct sockaddr *) &in_sto,
                        &sto_len))
  {
    memcpy (&in_sto, in, in_len);
    sto_len = in_len;
  }
  GNUNET_free (in);
  GNUNET_free (bindto);
  in = (struct sockaddr *) &in_sto;
  in_len = sto_len;
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "Bound to `%s'\n",
              GNUNET_a2s ((const struct sockaddr *) &in_sto, sto_len));
  switch (in->sa_family)
  {
  case AF_INET:
    my_port = ntohs (((struct sockaddr_in *) in)->sin_port);
    break;

  case AF_INET6:
    my_port = ntohs (((struct sockaddr_in6 *) in)->sin6_port);
    break;

  default:
    GNUNET_break (0);
    my_port = 0;
  }
  stats = GNUNET_STATISTICS_create ("C-UDP", cfg);
  senders = GNUNET_CONTAINER_multipeermap_create (32, GNUNET_YES);
  receivers = GNUNET_CONTAINER_multipeermap_create (32, GNUNET_YES);
  senders_heap = GNUNET_CONTAINER_heap_create (GNUNET_CONTAINER_HEAP_ORDER_MIN);
  receivers_heap =
    GNUNET_CONTAINER_heap_create (GNUNET_CONTAINER_HEAP_ORDER_MIN);
  key_cache = GNUNET_CONTAINER_multishortmap_create (1024, GNUNET_YES);
  GNUNET_SCHEDULER_add_shutdown (&do_shutdown, NULL);
  is = GNUNET_NT_scanner_init ();
  my_private_key = GNUNET_CRYPTO_eddsa_key_create_from_configuration (cfg);
  if (NULL == my_private_key)
  {
    GNUNET_log (
      GNUNET_ERROR_TYPE_ERROR,
      _ (
        "Transport service is lacking key configuration settings. Exiting.\n"));
    GNUNET_SCHEDULER_shutdown ();
    return;
  }
  GNUNET_CRYPTO_eddsa_key_get_public (my_private_key, &my_identity.public_key);
  /* start reading */
  read_task = GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_UNIT_FOREVER_REL,
                                             udp_sock,
                                             &sock_read,
                                             NULL);
  ch = GNUNET_TRANSPORT_communicator_connect (cfg,
                                              COMMUNICATOR_CONFIG_SECTION,
                                              COMMUNICATOR_ADDRESS_PREFIX,
                                              GNUNET_TRANSPORT_CC_UNRELIABLE,
                                              &mq_init,
                                              NULL,
                                              &enc_notify_cb,
                                              NULL);
  if (NULL == ch)
  {
    GNUNET_break (0);
    GNUNET_SCHEDULER_shutdown ();
    return;
  }
  ah = GNUNET_TRANSPORT_application_init (cfg);
  if (NULL == ah)
  {
    GNUNET_break (0);
    GNUNET_SCHEDULER_shutdown ();
    return;
  }
  /* start broadcasting */
  if (GNUNET_YES !=
      GNUNET_CONFIGURATION_get_value_yesno (cfg,
                                            COMMUNICATOR_CONFIG_SECTION,
                                            "DISABLE_BROADCAST"))
  {
    broadcast_task = GNUNET_SCHEDULER_add_now (&do_broadcast, NULL);
  }
  nat = GNUNET_NAT_register (cfg,
                             COMMUNICATOR_CONFIG_SECTION,
                             IPPROTO_UDP,
                             1 /* one address */,
                             (const struct sockaddr **) &in,
                             &in_len,
                             &nat_address_cb,
                             NULL /* FIXME: support reversal: #5529 */,
                             NULL /* closure */);
}

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main()

int main	(	int	argc,
		char *const *	argv
	)

The main function for the UNIX communicator.

Parameters

argc	number of arguments from the command line
argv	command line arguments

Returns

0 ok, 1 on error

Definition at line 2884 of file gnunet-communicator-udp.c.

References _, GNUNET_free_nz, GNUNET_GETOPT_OPTION_END, GNUNET_OK, GNUNET_PROGRAM_run(), GNUNET_STRINGS_get_utf8_args(), ret, and run().

{
  static const struct GNUNET_GETOPT_CommandLineOption options[] = {
    GNUNET_GETOPT_OPTION_END
  };
  int ret;

  if (GNUNET_OK != GNUNET_STRINGS_get_utf8_args (argc, argv, &argc, &argv))
    return 2;

  ret = (GNUNET_OK == GNUNET_PROGRAM_run (argc,
                                          argv,
                                          "gnunet-communicator-udp",
                                          _ ("GNUnet UDP communicator"),
                                          options,
                                          &run,
                                          NULL))
        ? 0
        : 1;
  GNUNET_free_nz ((void *) argv);
  return ret;
}

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Variable Documentation

key_cache

struct GNUNET_CONTAINER_MultiShortmap* key_cache

static

Cache of pre-generated key IDs.

Definition at line 660 of file gnunet-communicator-udp.c.

read_task

struct GNUNET_SCHEDULER_Task* read_task

static

ID of read task.

Definition at line 665 of file gnunet-communicator-udp.c.

timeout_task

struct GNUNET_SCHEDULER_Task* timeout_task

static

ID of timeout task.

Definition at line 670 of file gnunet-communicator-udp.c.

broadcast_task

struct GNUNET_SCHEDULER_Task* broadcast_task

static

ID of master broadcast task.

Definition at line 675 of file gnunet-communicator-udp.c.

stats

struct GNUNET_STATISTICS_Handle* stats

static

For logging statistics.

Definition at line 680 of file gnunet-communicator-udp.c.

ch

struct GNUNET_TRANSPORT_CommunicatorHandle* ch

static

Our environment.

Definition at line 685 of file gnunet-communicator-udp.c.

receivers

struct GNUNET_CONTAINER_MultiPeerMap* receivers

static

Receivers (map from peer identity to struct ReceiverAddress)

Definition at line 690 of file gnunet-communicator-udp.c.

senders

struct GNUNET_CONTAINER_MultiPeerMap* senders

static

Senders (map from peer identity to struct SenderAddress)

Definition at line 695 of file gnunet-communicator-udp.c.

senders_heap

struct GNUNET_CONTAINER_Heap* senders_heap

static

Expiration heap for senders (contains struct SenderAddress)

Definition at line 700 of file gnunet-communicator-udp.c.

receivers_heap

struct GNUNET_CONTAINER_Heap* receivers_heap

static

Expiration heap for receivers (contains struct ReceiverAddress)

Definition at line 705 of file gnunet-communicator-udp.c.

bi_head

struct BroadcastInterface* bi_head

static

Broadcast interface tasks.

Kept in a DLL.

Definition at line 710 of file gnunet-communicator-udp.c.

bi_tail

struct BroadcastInterface* bi_tail

static

Broadcast interface tasks.

Kept in a DLL.

Definition at line 715 of file gnunet-communicator-udp.c.

udp_sock

struct GNUNET_NETWORK_Handle* udp_sock

static

Our socket.

Definition at line 720 of file gnunet-communicator-udp.c.

have_v6_socket

int have_v6_socket

static

GNUNET_YES if udp_sock supports IPv6.

Definition at line 725 of file gnunet-communicator-udp.c.

Referenced by iface_proc(), and run().

my_identity

struct GNUNET_PeerIdentity my_identity

static

Our public key.

Definition at line 730 of file gnunet-communicator-udp.c.

Referenced by iface_proc(), mq_send_kx(), run(), and verify_confirmation().

my_private_key

struct GNUNET_CRYPTO_EddsaPrivateKey* my_private_key

static

Our private key.

Definition at line 735 of file gnunet-communicator-udp.c.

cfg

const struct GNUNET_CONFIGURATION_Handle* cfg

static

Our configuration.

Definition at line 740 of file gnunet-communicator-udp.c.

ah

struct GNUNET_TRANSPORT_ApplicationHandle* ah

static

Our handle to report addresses for validation to TRANSPORT.

Definition at line 745 of file gnunet-communicator-udp.c.

is

struct GNUNET_NT_InterfaceScanner* is

static

Network scanner to determine network types.

Definition at line 750 of file gnunet-communicator-udp.c.

nat

struct GNUNET_NAT_Handle* nat

static

Connection to NAT service.

Definition at line 755 of file gnunet-communicator-udp.c.

my_port

uint16_t my_port

static

Port number to which we are actually bound.

Definition at line 760 of file gnunet-communicator-udp.c.

Referenced by ifc_broadcast(), and run().