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edge.c
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edge.c
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/**
* (C) 2007-09 - Luca Deri <[email protected]>
* Richard Andrews <[email protected]>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not see see <http://www.gnu.org/licenses/>
*
* Code contributions courtesy of:
* Don Bindner <[email protected]>
* Sylwester Sosnowski <[email protected]>
* Wilfried "Wonka" Klaebe
* Lukasz Taczuk
*
*/
#include "n2n.h"
#include "n2n_transforms.h"
#include "n2n_log.h"
#include "n2n_utils.h"
#include "edge.h"
#include "edge_mgmt.h"
#include "tuntap.h"
#include "minilzo.h"
#include <assert.h>
//TODO
#define N2N_DEFAULT_IFACE "edge0"
#define DEFAULT_NET_MASK "255.255.255.0"
/* Work-memory needed for compression. Allocate memory in units
* of `lzo_align_t' (instead of `char') to make sure it is properly aligned.
*/
/* #define HEAP_ALLOC(var,size) \ */
/* lzo_align_t __LZO_MMODEL var [ ((size) + (sizeof(lzo_align_t) - 1)) / sizeof(lzo_align_t) ] */
/* static HEAP_ALLOC(wrkmem,LZO1X_1_MEM_COMPRESS); */
/* ******************************************************* */
/** Return the IP address of the current supernode in the ring. */
/*
static const n2n_sock_t *supernode_ip(const n2n_edge_t *eee)
{
return eee->supernode;//TODO &eee->supernodes[eee->sn_idx];
}
*/
static n2n_sock_t* first_supernode(const n2n_edge_t *eee)
{
sn_list_entry_t *first = N2N_LIST_FIRST_ENTRY(&eee->supernodes, sn_list_entry_t);
if (first)
return &first->sock;
return NULL;
}
static n2n_sock_t *next_supernode(const n2n_edge_t *eee)
{
n2n_sock_t *next_sn = NULL;
if (eee->supernode)
{
sn_list_entry_t *crnt = CONTAINER_OF(eee->supernode, sn_list_entry_t, sock);
if (crnt->list.next == &eee->supernodes.node)
next_sn = first_supernode(eee);
else
{
sn_list_entry_t *next = N2N_LIST_NEXT_ENTRY(crnt, sn_list_entry_t);
next_sn = &next->sock;
}
}
return next_sn;
}
/******************************************************************************/
/**
* Initialize an edge to defaults.
*
* This also initializes the NULL transform operation opstruct.
*/
static int edge_init(n2n_edge_t *eee)
{
#ifdef WIN32
initWin32();
#endif
memset(eee, 0, sizeof(n2n_edge_t));
eee->start_time = time(NULL);
transop_null_init(&(eee->transop[N2N_TRANSOP_NULL_IDX]));
transop_twofish_init(&(eee->transop[N2N_TRANSOP_TF_IDX]));
transop_aes_init(&(eee->transop[N2N_TRANSOP_AESCBC_IDX]));
eee->tx_transop_idx = N2N_TRANSOP_NULL_IDX; /* No guarantee the others have been setup */
eee->daemon = 1; /* By default run in daemon mode. */
eee->re_resolve_supernode_ip = 0;
/* keyschedule set to NULLs by memset */
/* community_name set to NULLs by memset */
eee->null_transop = 0;
eee->udp_sock = -1;
eee->udp_mgmt_sock = -1;
eee->ip_mode = N2N_IPM_STATIC;
eee->allow_routing = 0;
eee->drop_multicast = 1;
list_head_init(&eee->known_peers);
list_head_init(&eee->pending_peers);
eee->last_register_req = 0;
eee->register_lifetime = REGISTER_SUPER_INTERVAL_DFL;
eee->last_p2p = 0;
eee->last_sup = 0;
eee->sup_attempts = N2N_EDGE_SUP_ATTEMPTS;
if (lzo_init() != LZO_E_OK)
{
traceError("LZO compression error");
return (-1);
}
list_head_init(&eee->supernodes);
#ifdef N2N_MULTIPLE_SUPERNODES
list_head_init(&eee->queried_supernodes);
#endif
//TODO
//memset(&(eee->supernode), 0, sizeof(eee->supernode));
//eee->supernode.family = AF_INET;
eee->supernode = NULL;
//TODO
#ifndef WIN32
/* Device name matters on non-Windows environments */
strcpy(eee->device.dev_name, N2N_DEFAULT_IFACE);
#endif
eee->device.device_mask = inet_addr("255.255.255.0");//TODO
eee->device.mtu = DEFAULT_MTU;
/*
// TUNTAP: tuntap_dev_name, ip_mode, ip_addr, netmask, device_mac, mtu
//char tuntap_dev_name[N2N_IFNAMSIZ] = "edge0";
char ip_mode[N2N_IF_MODE_SIZE] = "static";
char ip_addr[N2N_NETMASK_STR_SIZE] = "";
char netmask[N2N_NETMASK_STR_SIZE] = "255.255.255.0";
//int mtu = DEFAULT_MTU;
*/
return (0);
}
/* Called in main() after options are parsed. */
static int edge_init_twofish(n2n_edge_t *eee, uint8_t *encrypt_pwd, uint32_t encrypt_pwd_len)
{
return transop_twofish_setup(&(eee->transop[N2N_TRANSOP_TF_IDX]), 0, encrypt_pwd, encrypt_pwd_len);
}
/**
* Find the transop op-struct for the transform enumeration required.
* @return - index into the transop array, or -1 on failure.
*/
static int transop_enum_to_index(n2n_transform_t id)
{
switch (id)
{
case N2N_TRANSFORM_ID_TWOFISH:
return N2N_TRANSOP_TF_IDX;
break;
case N2N_TRANSFORM_ID_NULL:
return N2N_TRANSOP_NULL_IDX;
break;
case N2N_TRANSFORM_ID_AESCBC:
return N2N_TRANSOP_AESCBC_IDX;
break;
default:
return -1;
}
}
/**
* Choose the transop for Tx. This should be based on the newest valid
* cipherspec in the key schedule.
*
* Never fall back to NULL transform unless no key sources were specified. It is
* better to render edge inoperative than to expose user data in the clear. In
* the case where all SAs are expired an arbitrary transform will be chosen for
* Tx. It will fail having no valid SAs but one must be selected.
*/
static size_t edge_choose_tx_transop(const n2n_edge_t *eee)//TODO make inline
{
if (eee->null_transop)
{
return N2N_TRANSOP_NULL_IDX;
}
return eee->tx_transop_idx;
}
/**
* Called periodically to roll keys and do any periodic maintenance in the
* transform operations state machines.
*/
static int n2n_tick_transop(n2n_edge_t *eee, time_t now)
{
n2n_tostat_t tst;
size_t trop = eee->tx_transop_idx;
/* Tests are done in order that most preferred transform is last and causes
* tx_transop_idx to be left at most preferred valid transform. */
tst = (eee->transop[N2N_TRANSOP_NULL_IDX].tick)(&(eee->transop[N2N_TRANSOP_NULL_IDX]), now);
tst = (eee->transop[N2N_TRANSOP_AESCBC_IDX].tick)(&(eee->transop[N2N_TRANSOP_AESCBC_IDX]), now);
if (tst.can_tx)
{
traceDebug("can_tx AESCBC (idx=%u)", (unsigned int) N2N_TRANSOP_AESCBC_IDX);
trop = N2N_TRANSOP_AESCBC_IDX;
}
tst = (eee->transop[N2N_TRANSOP_TF_IDX].tick)(&(eee->transop[N2N_TRANSOP_TF_IDX]), now);
if (tst.can_tx)
{
traceDebug("can_tx TF (idx=%u)", (unsigned int) N2N_TRANSOP_TF_IDX);
trop = N2N_TRANSOP_TF_IDX;
}
if (trop != eee->tx_transop_idx)
{
eee->tx_transop_idx = trop;
traceNormal("Chose new tx_transop_idx=%u", (unsigned int) (eee->tx_transop_idx));
}
return 0;
}
/**
* Read in a key-schedule file, parse the lines and pass each line to the
* appropriate trans_op for parsing of key-data and adding key-schedule
* entries. The lookup table of time->trans_op is constructed such that
* encoding can be passed to the correct trans_op. The trans_op internal table
* will then determine the best SA for that trans_op from the key schedule to
* use for encoding.
*/
/* TODO static*/ int edge_init_keyschedule(n2n_edge_t *eee)
{
#define N2N_NUM_CIPHERSPECS 32
int retval = -1;
ssize_t numSpecs = 0;
n2n_cipherspec_t specs[N2N_NUM_CIPHERSPECS];
size_t i;
time_t now = time(NULL);
numSpecs = n2n_read_keyfile(specs, N2N_NUM_CIPHERSPECS, eee->keyschedule);
if (numSpecs > 0)
{
traceNormal("keyfile = %s read -> %d specs.\n", optarg, (signed int) numSpecs);
for (i = 0; i < (size_t) numSpecs; ++i)
{
int idx;
idx = transop_enum_to_index(specs[i].t);
switch (idx)
{
case N2N_TRANSOP_TF_IDX:
case N2N_TRANSOP_AESCBC_IDX:
{
retval = (eee->transop[idx].addspec)(&(eee->transop[idx]),
&(specs[i]));
break;
}
default:
retval = -1;
break;
}
if (0 != retval)
{
traceError("keyschedule failed to add spec[%u] to transop[%d].\n",
(unsigned int) i, idx);
return retval;
}
}
n2n_tick_transop(eee, now);
}
else
{
traceError("Failed to process '%s'", eee->keyschedule);
}
return retval;
}
/**
* Deinitialize the edge and deallocate any owned memory.
*/
static void edge_deinit(n2n_edge_t *eee)
{
if (eee->udp_sock >= 0)
{
closesocket( eee->udp_sock);
}
if (eee->udp_mgmt_sock >= 0)
{
closesocket(eee->udp_mgmt_sock);
}
list_clear(&eee->pending_peers);
list_clear(&eee->known_peers);
(eee->transop[N2N_TRANSOP_TF_IDX].deinit)(&eee->transop[N2N_TRANSOP_TF_IDX]);
(eee->transop[N2N_TRANSOP_NULL_IDX].deinit)(&eee->transop[N2N_TRANSOP_NULL_IDX]);
#ifdef N2N_MULTIPLE_SUPERNODES
eee->snm_state = 0;//TODO redundant
list_clear(&eee->queried_supernodes);
#endif
}
/******************************************************************************
*
* EDGE <-> SUPERNODE COMMUNICATION
*
*/
/**
* Send a REGISTER_SUPER packet to the current supernode.
*/
static void send_register_super(n2n_edge_t *eee, const n2n_sock_t *supernode)
{
uint8_t pktbuf[N2N_PKT_BUF_SIZE];
size_t idx;
ssize_t sent;
n2n_common_t cmn;
n2n_flags_t flags = 0;
n2n_REGISTER_SUPER_t reg;
n2n_sock_str_t sockbuf;
#ifdef N2N_MULTIPLE_SUPERNODES
/*if (eee->sn_num == 1)//TODO
flags |= N2N_FLAGS_FED_C;*/
#endif
init_cmn(&cmn, n2n_register_super, flags, eee->community_name);
for (idx = 0; idx < N2N_COOKIE_SIZE; ++idx)
{
eee->last_cookie[idx] = rand() % 0xff;
}
memset(®, 0, sizeof(reg));
memcpy(reg.cookie, eee->last_cookie, N2N_COOKIE_SIZE);
reg.auth.scheme = 0; /* No auth yet */
idx = 0;
encode_mac(reg.edgeMac, &idx, eee->device.mac_addr);
idx = 0;
encode_REGISTER_SUPER(pktbuf, &idx, &cmn, ®);
traceInfo("Tx REGISTER_SUPER to %s", sock2str(sockbuf, supernode));
sent = sendto_sock(eee->udp_sock, pktbuf, idx, supernode);
}
/**
* @brief Check to see if we should re-register with the supernode.
*
* This is frequently called by the main loop.
*/
static void update_supernode_reg(n2n_edge_t *eee, time_t nowTime)
{
if (eee->sn_wait && (nowTime > (eee->last_register_req + (eee->register_lifetime / 10))))
{
/* fall through */
traceDebug("update_supernode_reg: doing fast retry.");
}
else if (nowTime < (eee->last_register_req + eee->register_lifetime))
/* Too early */
return;
if (0 == eee->sup_attempts)
{
/* Give up on that supernode and try the next one. */
++eee->sn_idx;
if (eee->sn_idx >= eee->sn_num)
{
/* Got to end of list, go back to the start.
* Also works for list of one entry. */
eee->sn_idx = 0;
}
traceWarning("Supernode not responding - moving to %u of %u",
(unsigned int) eee->sn_idx, (unsigned int) eee->sn_num);
eee->sup_attempts = N2N_EDGE_SUP_ATTEMPTS;
}
else
{
--eee->sup_attempts;
}
if (eee->re_resolve_supernode_ip || (eee->sn_num > 1))
{
//TODO supernode2addr(&(eee->supernode), eee->sn_ip_array[eee->sn_idx]);
//TODO remove eee->supernode = eee->supernodes[eee->sn_idx];
eee->supernode = next_supernode(eee);
}
send_register_super(eee, eee->supernode);
{
n2n_sock_str_t sockstr;
traceDebug("Registering with supernode (%s) (attempts left %u)",
sock2str(sockstr, eee->supernode),
(unsigned int) eee->sup_attempts);
}
eee->sn_wait = 1;
/* REVISIT: turn-on gratuitous ARP with config option. */
/* send_grat_arps(sock_fd, is_udp_sock); */
eee->last_register_req = nowTime;
}
static int add_supernode(n2n_edge_t *eee, n2n_sock_t *sock)
{
sn_list_entry_t *sn = malloc(sizeof(sn_list_entry_t));
if (NULL == sn)
{
traceError("Error allocating new 'sn_list_entry_t'");
return -1;
}
sock_cpy(&sn->sock, sock);
list_add(&eee->supernodes, &sn->list);
++eee->sn_num;
return 0;
}
#ifdef N2N_MULTIPLE_SUPERNODES
static void send_query(n2n_edge_t *eee, const n2n_sock_t *dst)
{
uint8_t pktbuf[N2N_PKT_BUF_SIZE];
size_t idx;
n2n_common_t cmn;
n2n_QUERY_SUPER_t query;
n2n_sock_str_t sockbuf;
init_cmn(&cmn, n2n_query_super, N2N_FLAGS_FED_C, eee->community_name);//TODO
idx = 0;
encode_common(pktbuf, &idx, &cmn);
encode_QUERY_SUPER(pktbuf, &idx, &cmn, &query);
traceInfo("Tx QUERY_SUPER to %s", sock2str(sockbuf, dst));
sendto_sock(eee->udp_sock, pktbuf, idx, dst);
}
static void query_supernodes(n2n_edge_t *eee, time_t now)
{
sn_info_t *qi = NULL;
N2N_LIST_FOR_EACH(&eee->queried_supernodes, qi)
{
send_query(eee, &qi->sock);
}
eee->snm_state = N2N_SNM_STATE_DISCOVERY;
}
static int sn_rank(const sn_info_t *sni)
{
int delta = N2N_MAX_COMM_PER_SN - sni->edges_num;
delta = MAX(delta, 1);
return (int) (sni->timestamp * 100 / delta);
}
static int sn_cmp_rank_asc(const void *l, const void *r)
{
return (sn_rank((const struct sn_info *) l) -
sn_rank((const struct sn_info *) r));
}
static void choose_supernodes(n2n_edge_t *eee, time_t now)
{
/* if (eee->snm_discovery_state != N2N_SNM_STATE_DISCOVERY)
{
return;
}*/
if (now - eee->start_time < N2N_SUPER_DISCOVERY_INTERVAL)
{
return;
}
/* Supernodes may already coordinate our community (eee->sn_num > 0) */
if (eee->sn_num < N2N_EDGE_NUM_SUPERNODES)
{
sn_info_t *scan = NULL;
n2n_sock_str_t sockbuf;
/* The best are first */
list_sort(&eee->queried_supernodes, sn_cmp_rank_asc);
N2N_LIST_FOR_EACH(&eee->queried_supernodes, scan)
{
if (scan->timestamp == 0)
/* No response */
break;
//TODO without duplicates
traceNormal("supernode %u => %s\n", eee->sn_num,
sock2str(sockbuf, &scan->sock));
add_supernode(eee, &scan->sock);
if (eee->sn_num == N2N_EDGE_NUM_SUPERNODES)
break;
}
}
if (eee->sn_num > 0)
{
eee->supernode = first_supernode(eee);
eee->snm_state = N2N_SNM_STATE_READY;
update_supernode_reg(eee, now);
//TODO remove send_register_super(eee, &sni->sock);
}
}
static int find_known_supernode_by_sock(n2n_edge_t *eee, const n2n_sock_t *sock)
{
sn_info_t *sn = find_supernode_info(&eee->queried_supernodes, sock);
if (NULL == sn)
{
sn = find_supernode_info(&eee->supernodes, sock);
}
return -(sn == NULL);
}
#endif
/******************************************************************************
*
* EDGE <-> EDGE (P2P) COMMUNICATION
*
*/
/**
* Send a REGISTER packet to another edge.
*/
static void send_register(n2n_edge_t *eee, const n2n_sock_t *remote_peer)
{
uint8_t pktbuf[N2N_PKT_BUF_SIZE];
size_t idx;
ssize_t sent;
n2n_common_t cmn;
n2n_REGISTER_t reg;
n2n_sock_str_t sockbuf;
init_cmn(&cmn, n2n_register, 0, eee->community_name);
memset(®, 0, sizeof(reg));
idx = 0;
encode_uint32(reg.cookie, &idx, 123456789);
idx = 0;
encode_mac(reg.srcMac, &idx, eee->device.mac_addr);
idx = 0;
encode_REGISTER(pktbuf, &idx, &cmn, ®);
traceInfo("Tx REGISTER %s", sock2str(sockbuf, remote_peer));
sent = sendto_sock(eee->udp_sock, pktbuf, idx, remote_peer);
}
/**
* Send a REGISTER_ACK packet to a peer edge.
*/
static void send_register_ack(n2n_edge_t *eee,
const n2n_sock_t *remote_peer,
const n2n_REGISTER_t *reg)
{
uint8_t pktbuf[N2N_PKT_BUF_SIZE];
size_t idx;
ssize_t sent;
n2n_common_t cmn;
n2n_REGISTER_ACK_t ack;
n2n_sock_str_t sockbuf;
init_cmn(&cmn, n2n_register_ack, 0, eee->community_name);
memset(&ack, 0, sizeof(ack));
memcpy(ack.cookie, reg->cookie, N2N_COOKIE_SIZE);
memcpy(ack.srcMac, eee->device.mac_addr, N2N_MAC_SIZE);
memcpy(ack.dstMac, reg->srcMac, N2N_MAC_SIZE);
idx = 0;
encode_REGISTER_ACK(pktbuf, &idx, &cmn, &ack);
traceInfo("Tx REGISTER_ACK %s", sock2str(sockbuf, remote_peer));
sent = sendto_sock(eee->udp_sock, pktbuf, idx, remote_peer);
}
/** NOT IMPLEMENTED
*
* This would send a DEREGISTER packet to a peer edge or supernode to indicate
* the edge is going away.
*/
static void send_deregister(n2n_edge_t *eee,
n2n_sock_t *remote_peer)
{
/* Marshall and send message */
}
/**
* Start the registration process.
*
* If the peer is already in pending_peers, ignore the request.
* If not in pending_peers, add it and send a REGISTER.
*
* If hdr is for a direct peer-to-peer packet, try to register back to sender
* even if the MAC is in pending_peers. This is because an incident direct
* packet indicates that peer-to-peer exchange should work so more aggressive
* registration can be permitted (once per incoming packet) as this should only
* last for a small number of packets..
*
* Called from the main loop when Rx a packet for our device MAC.
*/
static void try_send_register(n2n_edge_t *eee, uint8_t from_supernode,
const n2n_mac_t mac, const n2n_sock_t *peer)
{
/* REVISIT: purge of pending_peers not yet done. */
macstr_t mac_buf;
n2n_sock_str_t sockbuf;
peer_info_t *scan = find_peer_by_mac(&eee->pending_peers, mac);
if (scan)
return;
scan = calloc(1, sizeof(peer_info_t));
memcpy(scan->mac_addr, mac, N2N_MAC_SIZE);
scan->sock = *peer;
scan->last_seen = time(NULL); /* Don't change this it marks the pending peer for removal. */
peer_list_add(&eee->pending_peers, scan);
traceDebug("=== new pending %s -> %s",
mac2str(mac_buf, scan->mac_addr),
sock2str(sockbuf, &(scan->sock)));
traceInfo("Pending peers list size=%u",
(unsigned int) list_size(&eee->pending_peers));
/* trace Sending REGISTER */
send_register(eee, &(scan->sock));
/* pending_peers now owns scan. */
}
/**
* Move the peer from the pending_peers list to the known_peers lists.
*
* peer must be a pointer to an element of the pending_peers list.
*
* Called by main loop when Rx a REGISTER_ACK.
*/
static void set_peer_operational(n2n_edge_t *eee,
const n2n_mac_t mac, const n2n_sock_t *peer)
{
n2n_list_node_t *prev_node = NULL;
peer_info_t *scan;
macstr_t macbuf;
n2n_sock_str_t sockbuf;
traceInfo("set_peer_operational: %s -> %s",
mac2str(macbuf, mac), sock2str(sockbuf, peer));
scan = find_peer_by_mac_for_removal(&eee->pending_peers, mac, &prev_node);
if (scan == NULL)
{
traceDebug("Failed to find sender in pending_peers.");
return;
}
/* Remove scan from pending_peers. */
prev_node->next = scan->list.next;
scan->sock = *peer;
scan->last_seen = time(NULL);
/* Add scan to known_peers. */
list_add(&eee->known_peers, &scan->list);
traceDebug("=== new peer %s -> %s", macbuf, sockbuf);
traceInfo("Pending peers list size=%u",
(unsigned int) list_size(&eee->pending_peers));
traceInfo("Operational peers list size=%u",
(unsigned int) list_size(&eee->known_peers));
}
/**
* Keep the known_peers list straight.
*
* Ignore broadcast L2 packets, and packets with invalid public_ip.
* If the dst_mac is in known_peers make sure the entry is correct:
* - if the public_ip socket has changed, erase the entry
* - if the same, update its last_seen = when
*/
static void update_peer_address(n2n_edge_t *eee, uint8_t from_supernode,
const n2n_mac_t mac, const n2n_sock_t *peer,
time_t when)
{
peer_info_t *scan = NULL;
n2n_list_node_t *prev_node = NULL; /* use to remove bad registrations. */
n2n_sock_str_t sockbuf1;
n2n_sock_str_t sockbuf2; /* don't clobber sockbuf1 if writing two addresses to trace */
macstr_t macbuf;
if (is_empty_ip_address(peer))
/* Not to be registered. */
return;
if (is_broadcast_mac(mac))
/* Not to be registered. */
return;
scan = find_peer_by_mac_for_removal(&eee->known_peers, mac, &prev_node);
if (NULL == scan)
/* Not in known_peers. */
return;
if (0 != sock_equal(&scan->sock, peer))
{
if (0 == from_supernode)
{
traceNormal("Peer changed %s: %s -> %s",
mac2str(macbuf, scan->mac_addr),
sock2str(sockbuf1, &scan->sock),
sock2str(sockbuf2, peer));
/* The peer has changed public socket. It can no longer
* be assumed to be reachable. Remove the peer. */
prev_node->next = scan->list.next;
free(scan);
try_send_register(eee, from_supernode, mac, peer);
}
else
{
/* Don't worry about what the supernode reports,
* it could be seeing a different socket. */
}
}
else
{
/* Found and unchanged. */
scan->last_seen = when;
}
}
/**
* Update the last_seen time for this peer, or get registered.
*/
static void check_peer(n2n_edge_t *eee, uint8_t from_supernode,
const n2n_mac_t mac, const n2n_sock_t *peer)
{
peer_info_t *scan = find_peer_by_mac(&eee->known_peers, mac);
if (NULL == scan)
{
/* Not in known_peers - start the REGISTER process. */
try_send_register(eee, from_supernode, mac, peer);
}
else
{
/* Already in known_peers. */
update_peer_address(eee, from_supernode, mac, peer, time(NULL));
}
}
/**
* @return 1 if destination is a peer, 0 if destination is supernode
*/
static int find_peer_destination(n2n_edge_t *eee,
const n2n_mac_t mac, n2n_sock_t *destination)
{
const struct peer_info *scan = NULL;
macstr_t macbuf;
n2n_sock_str_t sockbuf;
int retval = 0;
traceDebug("Searching destination peer for MAC %s", mac2str(macbuf, mac));
N2N_LIST_FOR_EACH(&eee->known_peers, scan)
{
traceDebug("Evaluating peer [MAC=%s]", mac2str(macbuf, scan->mac_addr));
if (scan->last_seen > 0 && mac_equal(mac, scan->mac_addr))
{
memcpy(destination, &scan->sock, sizeof(n2n_sock_t));
retval = 1;
break;
}
}
if (0 == retval)
{
memcpy(destination, eee->supernode, sizeof(n2n_sock_t));
}
traceDebug("find_peer_destination (%s) -> [%s]",
mac2str(macbuf, mac), sock2str(sockbuf, destination));
return retval;
}
/******************************************************************************
*
* TUNNELING
*
*/
/* Read from TAP device */
/**
* Send an encapsulated Ethernet PACKET to a destination edge or broadcast MAC
* address.
*/
static ssize_t send_PACKET(n2n_edge_t *eee, n2n_mac_t dst_mac,
const uint8_t *pktbuf, size_t pktlen)
{
int is_p2p_dest;
ssize_t s;
n2n_sock_str_t sockbuf;
n2n_sock_t destination;
/* hexdump( pktbuf, pktlen ); */
is_p2p_dest = find_peer_destination(eee, dst_mac, &destination);
if (is_p2p_dest)
{
++(eee->tx_p2p);
}
else
{
++(eee->tx_sup);
}
traceInfo("send_PACKET to %s", sock2str(sockbuf, &destination));
s = sendto_sock(eee->udp_sock, pktbuf, pktlen, &destination);
return s;
}
/**
* A layer-2 packet was received at the tunnel and needs to be sent via UDP.
*/
static void send_packet2net(n2n_edge_t *eee, uint8_t *tap_pkt, size_t len)
{
n2n_PACKET_t pkt;
n2n_common_t cmn;
uint8_t pktbuf[N2N_PKT_BUF_SIZE];
size_t pktlen = 0;
size_t tx_transop_idx = 0;
n2n_trans_op_t *tx_transop = NULL;
ether_hdr_t eh;
//TODO n2n_mac_t dest_mac;
uint8_t *dest_mac;
/* tap_pkt is not aligned so we have to copy to aligned memory */
memcpy(&eh, tap_pkt, sizeof(ether_hdr_t));
/* Discard IP packets that are not originated by this hosts */
if (!(eee->allow_routing))
{
if (ntohs(eh.type) == 0x0800)//TODO
{
/* This is an IP packet from the local source address - not forwarded. */
#define ETH_FRAMESIZE 14
#define IP4_SRCOFFSET 12
uint32_t *dst = (uint32_t *) &tap_pkt[ETH_FRAMESIZE + IP4_SRCOFFSET];
/* Note: all elements of the_ip are in network order */
if (*dst != eee->device.ip_addr)
{
ipstr_t ip_buf;
/* This is a packet that needs to be routed */
traceInfo("Discarding routed packet [%s]",
intoa(ntohl(*dst), ip_buf, sizeof(ip_buf)));//TODO
return;
}
else
{
/* This packet is originated by us */
/* traceInfo("Sending non-routed packet"); */
}
}
}
/* Optionally compress then apply transforms, e.g. encryption. */
/* Once processed, send to destination in PACKET */
//TODO memcpy(dest_mac, tap_pkt, N2N_MAC_SIZE); /* dest MAC is first in ethernet header */
dest_mac = eh.dhost;
tx_transop_idx = edge_choose_tx_transop(eee);
//TODO
tx_transop = &eee->transop[tx_transop_idx];
/* no options, not from supernode, no socket */
init_cmn(&cmn, n2n_packet, 0, eee->community_name);
memset(&pkt, 0, sizeof(pkt));
memcpy(pkt.srcMac, eee->device.mac_addr, N2N_MAC_SIZE);
memcpy(pkt.dstMac, dest_mac, N2N_MAC_SIZE);
//pkt.sock.family = 0; /* do not encode sock */
pkt.transform = tx_transop->transform_id;
pktlen = 0;
encode_PACKET(pktbuf, &pktlen, &cmn, &pkt);
traceDebug("encoded PACKET header of size=%u transform %u (idx=%u)",
(unsigned int) pktlen, (unsigned int) pkt.transform, (unsigned int) tx_transop_idx);
/* Transform */
pktlen += tx_transop->fwd(tx_transop,
pktbuf + pktlen, N2N_PKT_BUF_SIZE - pktlen, /* out */
tap_pkt, len); /* in */
/* Update statistics (TODO: what if sending error?) */
++tx_transop->tx_cnt;
send_PACKET(eee, dest_mac, pktbuf, pktlen); /* to peer or supernode */
}