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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 <https://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 <assert.h>
#include <sys/stat.h>
#include "minilzo.h"
#ifdef N2N_MULTIPLE_SUPERNODES
#include "sn_multiple.h"
#endif
#if defined(DEBUG)
#define SOCKET_TIMEOUT_INTERVAL_SECS 5
#define REGISTER_SUPER_INTERVAL_DFL 20 /* sec */
#else /* #if defined(DEBUG) */
#define SOCKET_TIMEOUT_INTERVAL_SECS 10
#define REGISTER_SUPER_INTERVAL_DFL 60 /* sec */
#endif /* #if defined(DEBUG) */
#define REGISTER_SUPER_INTERVAL_MIN 20 /* sec */
#define REGISTER_SUPER_INTERVAL_MAX 3600 /* sec */
#define IFACE_UPDATE_INTERVAL (30) /* sec. How long it usually takes to get an IP lease. */
#define TRANSOP_TICK_INTERVAL (10) /* sec */
/** maximum length of command line arguments */
#define MAX_CMDLINE_BUFFER_LENGTH 4096
/** maximum length of a line in the configuration file */
#define MAX_CONFFILE_LINE_LENGTH 1024
#define N2N_PATHNAME_MAXLEN 256
#define N2N_MAX_TRANSFORMS 16
#define N2N_EDGE_MGMT_PORT 5644
/** Positions in the transop array where various transforms are stored.
*
* Used by transop_enum_to_index(). See also the transform enumerations in
* n2n_transforms.h */
#define N2N_TRANSOP_NULL_IDX 0
#define N2N_TRANSOP_TF_IDX 1
#define N2N_TRANSOP_AESCBC_IDX 2
/* etc. */
/* 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); */
/* ******************************************************* */
#define N2N_EDGE_SN_HOST_SIZE 48
typedef char n2n_sn_name_t[N2N_EDGE_SN_HOST_SIZE];
#ifdef N2N_MULTIPLE_SUPERNODES
#define N2N_EDGE_NUM_SUPERNODES N2N_MAX_SN_PER_COMM
#else
#define N2N_EDGE_NUM_SUPERNODES 2
#endif
#define N2N_EDGE_SUP_ATTEMPTS 3 /* Number of failed attmpts before moving on to next supernode. */
/** Main structure type for edge. */
struct n2n_edge
{
int daemon; /**< Non-zero if edge should detach and run in the background. */
uint8_t re_resolve_supernode_ip;
n2n_sock_t supernode;
size_t sn_idx; /**< Currently active supernode. */
size_t sn_num; /**< Number of supernode addresses defined. */
n2n_sn_name_t sn_ip_array[N2N_EDGE_NUM_SUPERNODES];
int sn_wait; /**< Whether we are waiting for a supernode response. */
n2n_community_t community_name; /**< The community. 16 full octets. */
char keyschedule[N2N_PATHNAME_MAXLEN];
int null_transop; /**< Only allowed if no key sources defined. */
int udp_sock;
int udp_mgmt_sock; /**< socket for status info. */
tuntap_dev device; /**< All about the TUNTAP device */
int dyn_ip_mode; /**< Interface IP address is dynamically allocated, eg. DHCP. */
int allow_routing; /**< Accept packet no to interface address. */
int drop_multicast; /**< Multicast ethernet addresses. */
n2n_trans_op_t transop[N2N_MAX_TRANSFORMS]; /* one for each transform at fixed positions */
size_t tx_transop_idx; /**< The transop to use when encoding. */
struct peer_info * known_peers; /**< Edges we are connected to. */
struct peer_info * pending_peers; /**< Edges we have tried to register with. */
time_t last_register_req; /**< Check if time to re-register with super*/
size_t register_lifetime; /**< Time distance after last_register_req at which to re-register. */
time_t last_p2p; /**< Last time p2p traffic was received. */
time_t last_sup; /**< Last time a packet arrived from supernode. */
size_t sup_attempts; /**< Number of remaining attempts to this supernode. */
n2n_cookie_t last_cookie; /**< Cookie sent in last REGISTER_SUPER. */
time_t start_time; /**< For calculating uptime */
/* Statistics */
size_t tx_p2p;
size_t rx_p2p;
size_t tx_sup;
size_t rx_sup;
#ifdef N2N_MULTIPLE_SUPERNODES
uint8_t snm_discovery_state;
int snm_sock;
sn_list_t supernodes;
struct sn_info reg_sn;
#endif
};
/** Return the IP address of the current supernode in the ring. */
static const char * supernode_ip( const n2n_edge_t * eee )
{
return (eee->sn_ip_array)[eee->sn_idx];
}
static void supernode2addr(n2n_sock_t * sn, const n2n_sn_name_t addr);
static void send_packet2net(n2n_edge_t * eee,
uint8_t *decrypted_msg, size_t len);
/* ************************************** */
/* parse the configuration file */
static int readConfFile(const char * filename, char * const linebuffer) {
struct stat stats;
FILE * fd;
char * buffer = NULL;
buffer = (char *)malloc(MAX_CONFFILE_LINE_LENGTH);
if (!buffer) {
traceEvent( TRACE_ERROR, "Unable to allocate memory");
return -1;
}
if (stat(filename, &stats)) {
if (errno == ENOENT)
traceEvent(TRACE_ERROR, "parameter file %s not found/unable to access\n", filename);
else
traceEvent(TRACE_ERROR, "cannot stat file %s, errno=%d\n",filename, errno);
free(buffer);
return -1;
}
fd = fopen(filename, "rb");
if (!fd) {
traceEvent(TRACE_ERROR, "Unable to open parameter file '%s' (%d)...\n",filename,errno);
free(buffer);
return -1;
}
while(fgets(buffer, MAX_CONFFILE_LINE_LENGTH,fd)) {
char * p = NULL;
/* strip out comments */
p = strchr(buffer, '#');
if (p) *p ='\0';
/* remove \n */
p = strchr(buffer, '\n');
if (p) *p ='\0';
/* strip out heading spaces */
p = buffer;
while(*p == ' ' && *p != '\0') ++p;
if (p != buffer) strncpy(buffer,p,strlen(p)+1);
/* strip out trailing spaces */
while(strlen(buffer) && buffer[strlen(buffer)-1]==' ')
buffer[strlen(buffer)-1]= '\0';
/* check for nested @file option */
if (strchr(buffer, '@')) {
traceEvent(TRACE_ERROR, "@file in file nesting is not supported\n");
free(buffer);
return -1;
}
if ((strlen(linebuffer)+strlen(buffer)+2)< MAX_CMDLINE_BUFFER_LENGTH) {
strncat(linebuffer, " ", 1);
strncat(linebuffer, buffer, strlen(buffer));
} else {
traceEvent(TRACE_ERROR, "too many argument");
free(buffer);
return -1;
}
}
free(buffer);
fclose(fd);
return 0;
}
/* Create the argv vector */
static char ** buildargv(int * effectiveargc, char * const linebuffer) {
const int INITIAL_MAXARGC = 16; /* Number of args + NULL in initial argv */
int maxargc;
int argc=0;
char ** argv;
char * buffer, * buff;
*effectiveargc = 0;
buffer = (char *)calloc(1, strlen(linebuffer)+2);
if (!buffer) {
traceEvent( TRACE_ERROR, "Unable to allocate memory");
return NULL;
}
strncpy(buffer, linebuffer,strlen(linebuffer));
maxargc = INITIAL_MAXARGC;
argv = (char **)malloc(maxargc * sizeof(char*));
if (argv == NULL) {
traceEvent( TRACE_ERROR, "Unable to allocate memory");
return NULL;
}
buff = buffer;
while(buff) {
char * p = strchr(buff,' ');
if (p) {
*p='\0';
argv[argc++] = strdup(buff);
while(*++p == ' ' && *p != '\0');
buff=p;
if (argc >= maxargc) {
maxargc *= 2;
argv = (char **)realloc(argv, maxargc * sizeof(char*));
if (argv == NULL) {
traceEvent(TRACE_ERROR, "Unable to re-allocate memory");
free(buffer);
return NULL;
}
}
} else {
argv[argc++] = strdup(buff);
break;
}
}
free(buffer);
*effectiveargc = argc;
return argv;
}
/* ************************************** */
/** Initialise an edge to defaults.
*
* This also initialises 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->dyn_ip_mode = 0;
eee->allow_routing = 0;
eee->drop_multicast = 1;
eee->known_peers = NULL;
eee->pending_peers = NULL;
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)
{
traceEvent(TRACE_ERROR, "LZO compression error");
return(-1);
}
#ifdef N2N_MULTIPLE_SUPERNODES
eee->snm_sock = -1;
eee->snm_discovery_state = N2N_SNM_STATE_DISCOVERY;
memset(&eee->supernodes, 0, sizeof(sn_list_t));
#endif
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;
}
}
/** Called periodically to roll keys and do any periodic maintenance in the
* tranform 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 )
{
traceEvent( TRACE_DEBUG, "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 )
{
traceEvent( TRACE_DEBUG, "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;
traceEvent( TRACE_NORMAL, "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. */
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 )
{
traceEvent( TRACE_NORMAL, "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;
}
if (0 != retval)
{
traceEvent( TRACE_ERROR, "keyschedule failed to add spec[%u] to transop[%d].\n",
(unsigned int)i, idx);
return retval;
}
}
n2n_tick_transop( eee, now );
}
else
{
traceEvent( TRACE_ERROR, "Failed to process '%s'", eee->keyschedule );
}
return retval;
}
/** Deinitialise 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);
}
clear_peer_list( &(eee->pending_peers) );
clear_peer_list( &(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
if (eee->snm_sock >= 0)
{
closesocket(eee->snm_sock);
}
eee->snm_discovery_state = 0;
clear_sn_list(&eee->supernodes.list_head);
#endif
}
static void readFromIPSocket( n2n_edge_t * eee );
static void readFromMgmtSocket( n2n_edge_t * eee, int * keep_running );
static void help() {
print_n2n_version();
printf("edge "
#if defined(N2N_CAN_NAME_IFACE)
"-d <tun device> "
#endif /* #if defined(N2N_CAN_NAME_IFACE) */
"-a [static:|dhcp:]<tun IP address> "
"-c <community> "
"[-k <encrypt key> | -K <key file>] "
"[-s <netmask>] "
#if defined(N2N_HAVE_SETUID)
"[-u <uid> -g <gid>]"
#endif /* #ifndef N2N_HAVE_SETUID */
#if defined(N2N_HAVE_DAEMON)
"[-f]"
#endif /* #if defined(N2N_HAVE_DAEMON) */
"[-m <MAC address>]"
"\n"
"-l <supernode host:port> "
"[-p <local port>] [-M <mtu>] "
"[-r] [-E] [-v] [-t <mgmt port>] [-b] [-h]\n\n");
#ifdef __linux__
printf("-d <tun device> | tun device name\n");
#endif
printf("-a <mode:address> | Set interface address. For DHCP use '-r -a dhcp:0.0.0.0'\n");
printf("-c <community> | n2n community name the edge belongs to.\n");
printf("-k <encrypt key> | Encryption key (ASCII) - also N2N_KEY=<encrypt key>. Not with -K.\n");
printf("-K <key file> | Specify a key schedule file to load. Not with -k.\n");
printf("-s <netmask> | Edge interface netmask in dotted decimal notation (255.255.255.0).\n");
printf("-l <supernode host:port> | Supernode IP:port\n");
printf("-b | Periodically resolve supernode IP\n");
printf(" : (when supernodes are running on dynamic IPs)\n");
printf("-p <local port> | Fixed local UDP port.\n");
#ifndef WIN32
printf("-u <UID> | User ID (numeric) to use when privileges are dropped.\n");
printf("-g <GID> | Group ID (numeric) to use when privileges are dropped.\n");
#endif /* ifndef WIN32 */
#ifdef N2N_HAVE_DAEMON
printf("-f | Do not fork and run as a daemon; rather run in foreground.\n");
#endif /* #ifdef N2N_HAVE_DAEMON */
printf("-m <MAC address> | Fix MAC address for the TAP interface (otherwise it may be random)\n"
" : eg. -m 01:02:03:04:05:06\n");
printf("-M <mtu> | Specify n2n MTU of edge interface (default %d).\n", DEFAULT_MTU);
printf("-r | Enable packet forwarding through n2n community.\n");
printf("-E | Accept multicast MAC addresses (default=drop).\n");
printf("-v | Make more verbose. Repeat as required.\n");
printf("-t | Management UDP Port (for multiple edges on a machine).\n");
#ifdef N2N_MULTIPLE_SUPERNODES
printf("-x <SNM port> | SNM port.\n");
#endif
printf("\nEnvironment variables:\n");
printf(" N2N_KEY | Encryption key (ASCII). Not with -K or -k.\n" );
exit(0);
}
/** Send a datagram to a socket defined by a n2n_sock_t */
static ssize_t sendto_sock( int fd, const void * buf, size_t len, const n2n_sock_t * dest )
{
struct sockaddr_in peer_addr;
ssize_t sent;
fill_sockaddr( (struct sockaddr *) &peer_addr,
sizeof(peer_addr),
dest );
sent = sendto( fd, buf, len, 0/*flags*/,
(struct sockaddr *)&peer_addr, sizeof(struct sockaddr_in) );
if ( sent < 0 )
{
char * c = strerror(errno);
traceEvent( TRACE_ERROR, "sendto failed (%d) %s", errno, c );
}
else
{
traceEvent( TRACE_DEBUG, "sendto sent=%d to ", (signed int)sent );
}
return sent;
}
/** 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;
memset(&cmn, 0, sizeof(cmn) );
memset(®, 0, sizeof(reg) );
cmn.ttl=N2N_DEFAULT_TTL;
cmn.pc = n2n_register;
cmn.flags = 0;
memcpy( cmn.community, eee->community_name, N2N_COMMUNITY_SIZE );
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, ® );
traceEvent( TRACE_INFO, "send REGISTER %s",
sock_to_cstr( sockbuf, remote_peer ) );
sent = sendto_sock( eee->udp_sock, pktbuf, idx, remote_peer );
}
/** 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_REGISTER_SUPER_t reg;
n2n_sock_str_t sockbuf;
memset(&cmn, 0, sizeof(cmn) );
memset(®, 0, sizeof(reg) );
cmn.ttl=N2N_DEFAULT_TTL;
cmn.pc = n2n_register_super;
cmn.flags = 0;
memcpy( cmn.community, eee->community_name, N2N_COMMUNITY_SIZE );
for( idx=0; idx < N2N_COOKIE_SIZE; ++idx )
{
eee->last_cookie[idx] = rand() % 0xff;
}
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, ® );
traceEvent( TRACE_INFO, "send REGISTER_SUPER to %s",
sock_to_cstr( sockbuf, supernode ) );
sent = sendto_sock( eee->udp_sock, pktbuf, idx, supernode );
}
/** 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;
memset(&cmn, 0, sizeof(cmn) );
memset(&ack, 0, sizeof(reg) );
cmn.ttl=N2N_DEFAULT_TTL;
cmn.pc = n2n_register_ack;
cmn.flags = 0;
memcpy( cmn.community, eee->community_name, N2N_COMMUNITY_SIZE );
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 );
traceEvent( TRACE_INFO, "send REGISTER_ACK %s",
sock_to_cstr( 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 */
}
static int is_empty_ip_address( const n2n_sock_t * sock );
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);
void check_peer( n2n_edge_t * eee,
uint8_t from_supernode,
const n2n_mac_t mac,
const n2n_sock_t * peer );
void try_send_register( n2n_edge_t * eee,
uint8_t from_supernode,
const n2n_mac_t mac,
const n2n_sock_t * peer );
void set_peer_operational( n2n_edge_t * eee,
const n2n_mac_t mac,
const n2n_sock_t * peer );
/** 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.
*/
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. */
struct peer_info * scan = find_peer_by_mac( eee->pending_peers, mac );
macstr_t mac_buf;
n2n_sock_str_t sockbuf;
if ( NULL == scan )
{
scan = calloc( 1, sizeof( struct peer_info ) );
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 );
traceEvent( TRACE_DEBUG, "=== new pending %s -> %s",
macaddr_str( mac_buf, scan->mac_addr ),
sock_to_cstr( sockbuf, &(scan->sock) ) );
traceEvent( TRACE_INFO, "Pending peers list size=%u",
(unsigned int)peer_list_size( eee->pending_peers ) );
/* trace Sending REGISTER */
send_register(eee, &(scan->sock) );
/* pending_peers now owns scan. */
}
else
{
}
}
/** Update the last_seen time for this peer, or get registered. */
void check_peer( n2n_edge_t * eee,
uint8_t from_supernode,
const n2n_mac_t mac,
const n2n_sock_t * peer )
{
struct peer_info * 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) );
}
}
/* 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.
*/
void set_peer_operational( n2n_edge_t * eee,
const n2n_mac_t mac,
const n2n_sock_t * peer )
{
struct peer_info * prev = NULL;
struct peer_info * scan;
macstr_t mac_buf;
n2n_sock_str_t sockbuf;
traceEvent( TRACE_INFO, "set_peer_operational: %s -> %s",
macaddr_str( mac_buf, mac),
sock_to_cstr( sockbuf, peer ) );
scan=eee->pending_peers;
while ( NULL != scan )
{
if ( 0 == memcmp( scan->mac_addr, mac, N2N_MAC_SIZE ) )
{
break; /* found. */
}
prev = scan;
scan = scan->next;
}
if ( scan )
{
/* Remove scan from pending_peers. */
if ( prev )
{
prev->next = scan->next;
}
else
{
eee->pending_peers = scan->next;
}
/* Add scan to known_peers. */
scan->next = eee->known_peers;
eee->known_peers = scan;
scan->sock = *peer;
traceEvent( TRACE_DEBUG, "=== new peer %s -> %s",
macaddr_str( mac_buf, scan->mac_addr),
sock_to_cstr( sockbuf, &(scan->sock) ) );
traceEvent( TRACE_INFO, "Pending peers list size=%u",
(unsigned int)peer_list_size( eee->pending_peers ) );
traceEvent( TRACE_INFO, "Operational peers list size=%u",
(unsigned int)peer_list_size( eee->known_peers ) );
scan->last_seen = time(NULL);
}
else
{
traceEvent( TRACE_DEBUG, "Failed to find sender in pending_peers." );
}
}
n2n_mac_t broadcast_mac = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
static int is_empty_ip_address( const n2n_sock_t * sock )
{
const uint8_t * ptr=NULL;
size_t len=0;
size_t i;
if ( AF_INET6 == sock->family )
{
ptr = sock->addr.v6;
len = 16;
}
else
{
ptr = sock->addr.v4;
len = 4;
}
for (i=0; i<len; ++i)
{
if ( 0 != ptr[i] )
{
/* found a non-zero byte in address */
return 0;
}
}
return 1;
}
/** 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)
{
struct peer_info *scan = eee->known_peers;
struct peer_info *prev = 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 mac_buf;
if ( is_empty_ip_address( peer ) )
{
/* Not to be registered. */
return;
}
if ( 0 == memcmp( mac, broadcast_mac, N2N_MAC_SIZE ) )
{
/* Not to be registered. */
return;
}
while(scan != NULL)
{
if(memcmp(mac, scan->mac_addr, N2N_MAC_SIZE) == 0)
{
break;
}
prev = scan;
scan = scan->next;
}
if ( NULL == scan )
{
/* Not in known_peers. */
return;
}
if ( 0 != sock_equal( &(scan->sock), peer))
{
if ( 0 == from_supernode )
{
traceEvent( TRACE_NORMAL, "Peer changed %s: %s -> %s",
macaddr_str( mac_buf, scan->mac_addr ),
sock_to_cstr(sockbuf1, &(scan->sock)),
sock_to_cstr(sockbuf2, peer) );
/* The peer has changed public socket. It can no longer be assumed to be reachable. */
/* Remove the peer. */
if ( NULL == prev )
{
/* scan was head of list */
eee->known_peers = scan->next;
}
else
{
prev->next = scan->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;
}
}
#if defined(DUMMY_ID_00001) /* Disabled waiting for config option to enable it */
static char gratuitous_arp[] = {
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, /* Dest mac */
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* Src mac */