/*

Copyright (c) 2015 by Juliusz Chroboczek

Permission is hereby granted, free of charge, to any person obtaining a copy

of this software and associated documentation files (the "Software"), to deal

in the Software without restriction, including without limitation the rights

to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

copies of the Software, and to permit persons to whom the Software is

furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in

all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE

AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN

THE SOFTWARE.

*/

#include <assert.h>

#include <time.h>

#include <string.h>

#include <stdio.h>

#include <stdlib.h>

#include <errno.h>

#include <sys/types.h>

#include <sys/socket.h>

#include <netinet/in.h>

#include "shncpd.h"

#include "trickle.h"

#include "state.h"

#include "send.h"

#include "prefix.h"

#include "util.h"

#define SENDBUF_SIZE 4000

static unsigned char *sendbuf = NULL;

static int buffered = 0;

/* At most one of those can be set. */

static struct interface *buffered_interface = NULL;

static struct sockaddr_in6 buffered_sin6;

int

flushbuf()

{

struct sockaddr_in6 tob, *to;

int rc;

if(!buffered)

return 0;

if(buffered_interface) {

memset(&tob, 0, sizeof(tob));

tob.sin6_family = AF_INET6;

memcpy(&tob.sin6_addr, &protocol_group, 16);

tob.sin6_port = htons(protocol_port);

tob.sin6_scope_id = buffered_interface->ifindex;

to = &tob;

} else {

to = &buffered_sin6;

}

rc = sendto(protocol_socket, sendbuf, buffered, 0,

(struct sockaddr*)to, sizeof(struct sockaddr_in6));

if(rc < 0) {

int saved_errno = errno;

perror("sendto");

errno = saved_errno;

}

buffered_interface = NULL;

buffered = 0;

MEM_UNDEFINED(sendbuf, SENDBUF_SIZE);

MEM_UNDEFINED(&buffered_sin6, sizeof(buffered_sin6));

return rc;

}

int

buffer_tlv(int type, const unsigned char *data, int datalen,

const struct sockaddr_in6 *sin6, struct interface *interface)

{

if(interface && sin6) {

errno = EINVAL;

return -1;

}

if(sendbuf == NULL)

sendbuf = allocate_buffer(SENDBUF_SIZE);

if(sendbuf == NULL)

return -1;

if(buffered &&

((interface && interface != buffered_interface) ||

(!interface && (buffered_interface ||

memcmp(sin6, &buffered_sin6, sizeof(*sin6)) != 0)) ||

buffered + datalen > 1400))

flushbuf();

if(buffered + datalen + 4 > SENDBUF_SIZE) {

errno = EMSGSIZE;

return -1;

}

if(!buffered) {

/* NODE-ENDPOINT */

DO_HTONS(sendbuf + 0, 3);

DO_HTONS(sendbuf + 2, 8);

memcpy(sendbuf + 4, myid, 4);

DO_HTONL(sendbuf + 8,

interface ? interface->ifindex : sin6->sin6_scope_id);

buffered = 12;

}

if(interface)

buffered_interface = interface;

else

memcpy(&buffered_sin6, sin6, sizeof(*sin6));

DO_HTONS(sendbuf + buffered, type); buffered += 2;

DO_HTONS(sendbuf + buffered, datalen); buffered += 2;

memcpy(sendbuf + buffered, data, datalen); buffered += datalen;

if(debug_level >= 3)

debugf("Buffering %s %d (%d)\n",

interface ? "multicast" : "unicast", type, datalen);

return 1;

}

int

buffer_network_state(const struct sockaddr_in6 *sin6,

struct interface *interface)

{

unsigned char h[8];

int rc;

rc = network_hash(h);

if(rc < 0)

return -1;

debugf("-> NETWORK-STATE %s%s\n",

format_64(h), interface ? " (multicast)" : "");

buffer_tlv(4, h, 8, sin6, interface);

return 1;

}

#define CHECK(_n) if(buflen < i + (_n)) goto fail

#define BYTE(_v) buf[i] = (_v); i++

#define BYTES(_v, _len) memcpy(buf + i, (_v), (_len)); i += (_len)

#define SHORT(_v) DO_HTONS(buf + i, (_v)); i += 2

#define LONG(_v) DO_HTONL(buf + i, (_v)); i += 4

#define PAD() while((i & 3) != 0) buf[i++] = 0

int

buffer_node_state(struct node *node, int full,

const struct sockaddr_in6 *sin6, struct interface *interface)

{

int buflen = full ? 20 + node->datalen : 20;

unsigned char buf[buflen];

int i = 0;

long long orig_delay =

(now.tv_sec - node->orig_time.tv_sec) * 1000LL +

((long long)now.tv_nsec - node->orig_time.tv_nsec + 999999) / 1000000;

BYTES(node->id, 4);

LONG(node->seqno);

LONG((unsigned)orig_delay);

BYTES(node->datahash, 8);

if(full) {

BYTES(node->data, node->datalen);

}

assert(i == buflen);

debugf("-> NODE-STATE %s%s\n",

format_32(node->id),

full && interface ? " (full, multicast)" :

full ? " (full)" :

interface ? " (multicast)" : "");

return buffer_tlv(5, buf, buflen, sin6, interface);

}

int

format_my_state(unsigned char *buf, int buflen)

{

int i = 0, j, k;

for(j = 0; j < numneighs; j++) {

CHECK(12);

SHORT(8);

SHORT(12);

BYTES(neighs[j].id, 4);

LONG(neighs[j].eid);

LONG(neighs[j].interface->ifindex);

PAD();

}

CHECK(11);

SHORT(32);

SHORT(12);

SHORT(0x100);

SHORT(0);

BYTES("SHNCPD/0", 8);

PAD();

for(j = 0; j < numinterfaces; j++) {

for(k = 0; k < interfaces[j].numassigned; k++) {

const struct assigned_prefix *aa = &interfaces[j].assigned[k];

int pbytes = (aa->assigned.plen + 7) / 8;

if(aa->published) {

assert(aa->assigned.plen > 0);

CHECK(10 + pbytes);

SHORT(35);

SHORT(6 + pbytes);

LONG(interfaces[j].ifindex);

BYTE((aa->assigned.prio & 0x0F));

BYTE(aa->assigned.plen);

BYTES(&aa->assigned.p, pbytes);

PAD();

}

if(!IN6_IS_ADDR_UNSPECIFIED(&aa->assigned_address)) {

CHECK(24);

SHORT(36);

SHORT(20);

LONG(interfaces[j].ifindex);

BYTES(&aa->assigned_address, 16);

PAD();

}

}

}

return i;

fail:

return -1;

}

#undef CHECK

#undef BYTE

#undef BYTES

#undef SHORT

#undef LONG

#undef PAD