babeld/resend.c - quagga - Gitiles

 /*
  *  This file is free software: you may copy, redistribute and/or modify it
  *  under the terms of the GNU General Public License as published by the
  *  Free Software Foundation, either version 2 of the License, or (at your
  *  option) any later version.
  *
  *  This file 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 <http://www.gnu.org/licenses/>.
  *
  * This file incorporates work covered by the following copyright and
  * permission notice:
  *
 Copyright (c) 2007, 2008 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 <sys/time.h>
 #include <time.h>
 #include <string.h>
 #include <stdlib.h>

 #include <zebra.h>
 #include "if.h"

 #include "babel_main.h"
 #include "babeld.h"
 #include "util.h"
 #include "neighbour.h"
 #include "resend.h"
 #include "message.h"
 #include "babel_interface.h"

 struct timeval resend_time = {0, 0};
 struct resend *to_resend = NULL;

 static int
 resend_match(struct resend *resend,
              int kind, const unsigned char *prefix, unsigned char plen)
 {
     return (resend->kind == kind &&
             resend->plen == plen && memcmp(resend->prefix, prefix, 16) == 0);
 }

 /* This is called by neigh.c when a neighbour is flushed */

 void
 flush_resends(struct neighbour *neigh)
 {
     /* Nothing for now */
 }

 static struct resend *
 find_resend(int kind, const unsigned char *prefix, unsigned char plen,
              struct resend **previous_return)
 {
     struct resend *current, *previous;

     previous = NULL;
     current = to_resend;
     while(current) {
         if(resend_match(current, kind, prefix, plen)) {
             if(previous_return)
                 *previous_return = previous;
             return current;
         }
         previous = current;
         current = current->next;
     }

     return NULL;
 }

 struct resend *
 find_request(const unsigned char *prefix, unsigned char plen,
              struct resend **previous_return)
 {
     return find_resend(RESEND_REQUEST, prefix, plen, previous_return);
 }

 int
 record_resend(int kind, const unsigned char *prefix, unsigned char plen,
               unsigned short seqno, const unsigned char *id,
               struct interface *ifp, int delay)
 {
     struct resend *resend;
     unsigned int ifindex = ifp ? ifp->ifindex : 0;

     if((kind == RESEND_REQUEST &&
         input_filter(NULL, prefix, plen, NULL, ifindex) >= INFINITY) ||
        (kind == RESEND_UPDATE &&
         output_filter(NULL, prefix, plen, ifindex) >= INFINITY))
         return 0;

     if(delay >= 0xFFFF)
         delay = 0xFFFF;

     resend = find_resend(kind, prefix, plen, NULL);
     if(resend) {
         if(resend->delay && delay)
             resend->delay = MIN(resend->delay, delay);
         else if(delay)
             resend->delay = delay;
         resend->time = babel_now;
         resend->max = RESEND_MAX;
         if(id && memcmp(resend->id, id, 8) == 0 &&
            seqno_compare(resend->seqno, seqno) > 0) {
             return 0;
         }
         if(id)
             memcpy(resend->id, id, 8);
         else
             memset(resend->id, 0, 8);
         resend->seqno = seqno;
         if(resend->ifp != ifp)
             resend->ifp = NULL;
     } else {
         resend = malloc(sizeof(struct resend));
         if(resend == NULL)
             return -1;
         resend->kind = kind;
         resend->max = RESEND_MAX;
         resend->delay = delay;
         memcpy(resend->prefix, prefix, 16);
         resend->plen = plen;
         resend->seqno = seqno;
         if(id)
             memcpy(resend->id, id, 8);
         else
             memset(resend->id, 0, 8);
         resend->ifp = ifp;
         resend->time = babel_now;
         resend->next = to_resend;
         to_resend = resend;
     }

     if(resend->delay) {
         struct timeval timeout;
         timeval_add_msec(&timeout, &resend->time, resend->delay);
         timeval_min(&resend_time, &timeout);
     }
     return 1;
 }

 static int
 resend_expired(struct resend *resend)
 {
     switch(resend->kind) {
     case RESEND_REQUEST:
         return timeval_minus_msec(&babel_now, &resend->time) >= REQUEST_TIMEOUT;
     default:
         return resend->max <= 0;
     }
 }

 int
 unsatisfied_request(const unsigned char *prefix, unsigned char plen,
                     unsigned short seqno, const unsigned char *id)
 {
     struct resend *request;

     request = find_request(prefix, plen, NULL);
     if(request == NULL || resend_expired(request))
         return 0;

     if(memcmp(request->id, id, 8) != 0 ||
        seqno_compare(request->seqno, seqno) <= 0)
         return 1;

     return 0;
 }

 /* Determine whether a given request should be forwarded. */
 int
 request_redundant(struct interface *ifp,
                   const unsigned char *prefix, unsigned char plen,
                   unsigned short seqno, const unsigned char *id)
 {
     struct resend *request;

     request = find_request(prefix, plen, NULL);
     if(request == NULL || resend_expired(request))
         return 0;

     if(memcmp(request->id, id, 8) == 0 &&
        seqno_compare(request->seqno, seqno) > 0)
         return 0;

     if(request->ifp != NULL && request->ifp != ifp)
         return 0;

     if(request->max > 0)
         /* Will be resent. */
         return 1;

     if(timeval_minus_msec(&babel_now, &request->time) <
        (ifp ? MIN(babel_get_if_nfo(ifp)->hello_interval, 1000) : 1000))
         /* Fairly recent. */
         return 1;

     return 0;
 }

 int
 satisfy_request(const unsigned char *prefix, unsigned char plen,
                 unsigned short seqno, const unsigned char *id,
                 struct interface *ifp)
 {
     struct resend *request, *previous;

     request = find_request(prefix, plen, &previous);
     if(request == NULL)
         return 0;

     if(ifp != NULL && request->ifp != ifp)
         return 0;

     if(memcmp(request->id, id, 8) != 0 ||
        seqno_compare(request->seqno, seqno) <= 0) {
         /* We cannot remove the request, as we may be walking the list right
            now.  Mark it as expired, so that expire_resend will remove it. */
         request->max = 0;
         request->time.tv_sec = 0;
         recompute_resend_time();
         return 1;
     }

     return 0;
 }

 void
 expire_resend()
 {
     struct resend *current, *previous;
     int recompute = 0;

     previous = NULL;
     current = to_resend;
     while(current) {
         if(resend_expired(current)) {
             if(previous == NULL) {
                 to_resend = current->next;
                 free(current);
                 current = to_resend;
             } else {
                 previous->next = current->next;
                 free(current);
                 current = previous->next;
             }
             recompute = 1;
         } else {
             previous = current;
             current = current->next;
         }
     }
     if(recompute)
         recompute_resend_time();
 }

 void
 recompute_resend_time()
 {
     struct resend *request;
     struct timeval resend = {0, 0};

     request = to_resend;
     while(request) {
         if(!resend_expired(request) && request->delay > 0 && request->max > 0) {
             struct timeval timeout;
             timeval_add_msec(&timeout, &request->time, request->delay);
             timeval_min(&resend, &timeout);
         }
         request = request->next;
     }

     resend_time = resend;
 }

 void
 do_resend()
 {
     struct resend *resend;

     resend = to_resend;
     while(resend) {
         if(!resend_expired(resend) && resend->delay > 0 && resend->max > 0) {
             struct timeval timeout;
             timeval_add_msec(&timeout, &resend->time, resend->delay);
             if(timeval_compare(&babel_now, &timeout) >= 0) {
                 switch(resend->kind) {
                 case RESEND_REQUEST:
                     send_multihop_request(resend->ifp,
                                           resend->prefix, resend->plen,
                                           resend->seqno, resend->id, 127);
                     break;
                 case RESEND_UPDATE:
                     send_update(resend->ifp, 1,
                                 resend->prefix, resend->plen);
                     break;
                 default: abort();
                 }
                 resend->delay = MIN(0xFFFF, resend->delay * 2);
                 resend->max--;
             }
         }
         resend = resend->next;
     }
     recompute_resend_time();
 }
	/*
	* This file is free software: you may copy, redistribute and/or modify it
	* under the terms of the GNU General Public License as published by the
	* Free Software Foundation, either version 2 of the License, or (at your
	* option) any later version.
	*
	* This file 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 <http://www.gnu.org/licenses/>.
	*
	* This file incorporates work covered by the following copyright and
	* permission notice:
	*
	Copyright (c) 2007, 2008 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 <sys/time.h>
	#include <time.h>
	#include <string.h>
	#include <stdlib.h>

	#include <zebra.h>
	#include "if.h"

	#include "babel_main.h"
	#include "babeld.h"
	#include "util.h"
	#include "neighbour.h"
	#include "resend.h"
	#include "message.h"
	#include "babel_interface.h"

	struct timeval resend_time = {0, 0};
	struct resend *to_resend = NULL;

	static int
	resend_match(struct resend *resend,
	int kind, const unsigned char *prefix, unsigned char plen)
	{
	return (resend->kind == kind &&
	resend->plen == plen && memcmp(resend->prefix, prefix, 16) == 0);
	}

	/* This is called by neigh.c when a neighbour is flushed */

	void
	flush_resends(struct neighbour *neigh)
	{
	/* Nothing for now */
	}

	static struct resend *
	find_resend(int kind, const unsigned char *prefix, unsigned char plen,
	struct resend **previous_return)
	{
	struct resend current, previous;

	previous = NULL;
	current = to_resend;
	while(current) {
	if(resend_match(current, kind, prefix, plen)) {
	if(previous_return)
	*previous_return = previous;
	return current;
	}
	previous = current;
	current = current->next;
	}

	return NULL;
	}

	struct resend *
	find_request(const unsigned char *prefix, unsigned char plen,
	struct resend **previous_return)
	{
	return find_resend(RESEND_REQUEST, prefix, plen, previous_return);
	}

	int
	record_resend(int kind, const unsigned char *prefix, unsigned char plen,
	unsigned short seqno, const unsigned char *id,
	struct interface *ifp, int delay)
	{
	struct resend *resend;
	unsigned int ifindex = ifp ? ifp->ifindex : 0;

	if((kind == RESEND_REQUEST &&
	input_filter(NULL, prefix, plen, NULL, ifindex) >= INFINITY) \|\|
	(kind == RESEND_UPDATE &&
	output_filter(NULL, prefix, plen, ifindex) >= INFINITY))
	return 0;

	if(delay >= 0xFFFF)
	delay = 0xFFFF;

	resend = find_resend(kind, prefix, plen, NULL);
	if(resend) {
	if(resend->delay && delay)
	resend->delay = MIN(resend->delay, delay);
	else if(delay)
	resend->delay = delay;
	resend->time = babel_now;
	resend->max = RESEND_MAX;
	if(id && memcmp(resend->id, id, 8) == 0 &&
	seqno_compare(resend->seqno, seqno) > 0) {
	return 0;
	}
	if(id)
	memcpy(resend->id, id, 8);
	else
	memset(resend->id, 0, 8);
	resend->seqno = seqno;
	if(resend->ifp != ifp)
	resend->ifp = NULL;
	} else {
	resend = malloc(sizeof(struct resend));
	if(resend == NULL)
	return -1;
	resend->kind = kind;
	resend->max = RESEND_MAX;
	resend->delay = delay;
	memcpy(resend->prefix, prefix, 16);
	resend->plen = plen;
	resend->seqno = seqno;
	if(id)
	memcpy(resend->id, id, 8);
	else
	memset(resend->id, 0, 8);
	resend->ifp = ifp;
	resend->time = babel_now;
	resend->next = to_resend;
	to_resend = resend;
	}

	if(resend->delay) {
	struct timeval timeout;
	timeval_add_msec(&timeout, &resend->time, resend->delay);
	timeval_min(&resend_time, &timeout);
	}
	return 1;
	}

	static int
	resend_expired(struct resend *resend)
	{
	switch(resend->kind) {
	case RESEND_REQUEST:
	return timeval_minus_msec(&babel_now, &resend->time) >= REQUEST_TIMEOUT;
	default:
	return resend->max <= 0;
	}
	}

	int
	unsatisfied_request(const unsigned char *prefix, unsigned char plen,
	unsigned short seqno, const unsigned char *id)
	{
	struct resend *request;

	request = find_request(prefix, plen, NULL);
	if(request == NULL \|\| resend_expired(request))
	return 0;

	if(memcmp(request->id, id, 8) != 0 \|\|
	seqno_compare(request->seqno, seqno) <= 0)
	return 1;

	return 0;
	}

	/* Determine whether a given request should be forwarded. */
	int
	request_redundant(struct interface *ifp,
	const unsigned char *prefix, unsigned char plen,
	unsigned short seqno, const unsigned char *id)
	{
	struct resend *request;

	request = find_request(prefix, plen, NULL);
	if(request == NULL \|\| resend_expired(request))
	return 0;

	if(memcmp(request->id, id, 8) == 0 &&
	seqno_compare(request->seqno, seqno) > 0)
	return 0;

	if(request->ifp != NULL && request->ifp != ifp)
	return 0;

	if(request->max > 0)
	/* Will be resent. */
	return 1;

	if(timeval_minus_msec(&babel_now, &request->time) <
	(ifp ? MIN(babel_get_if_nfo(ifp)->hello_interval, 1000) : 1000))
	/* Fairly recent. */
	return 1;

	return 0;
	}

	int
	satisfy_request(const unsigned char *prefix, unsigned char plen,
	unsigned short seqno, const unsigned char *id,
	struct interface *ifp)
	{
	struct resend request, previous;

	request = find_request(prefix, plen, &previous);
	if(request == NULL)
	return 0;

	if(ifp != NULL && request->ifp != ifp)
	return 0;

	if(memcmp(request->id, id, 8) != 0 \|\|
	seqno_compare(request->seqno, seqno) <= 0) {
	/* We cannot remove the request, as we may be walking the list right
	now. Mark it as expired, so that expire_resend will remove it. */
	request->max = 0;
	request->time.tv_sec = 0;
	recompute_resend_time();
	return 1;
	}

	return 0;
	}

	void
	expire_resend()
	{
	struct resend current, previous;
	int recompute = 0;

	previous = NULL;
	current = to_resend;
	while(current) {
	if(resend_expired(current)) {
	if(previous == NULL) {
	to_resend = current->next;
	free(current);
	current = to_resend;
	} else {
	previous->next = current->next;
	free(current);
	current = previous->next;
	}
	recompute = 1;
	} else {
	previous = current;
	current = current->next;
	}
	}
	if(recompute)
	recompute_resend_time();
	}

	void
	recompute_resend_time()
	{
	struct resend *request;
	struct timeval resend = {0, 0};

	request = to_resend;
	while(request) {
	if(!resend_expired(request) && request->delay > 0 && request->max > 0) {
	struct timeval timeout;
	timeval_add_msec(&timeout, &request->time, request->delay);
	timeval_min(&resend, &timeout);
	}
	request = request->next;
	}

	resend_time = resend;
	}

	void
	do_resend()
	{
	struct resend *resend;

	resend = to_resend;
	while(resend) {
	if(!resend_expired(resend) && resend->delay > 0 && resend->max > 0) {
	struct timeval timeout;
	timeval_add_msec(&timeout, &resend->time, resend->delay);
	if(timeval_compare(&babel_now, &timeout) >= 0) {
	switch(resend->kind) {
	case RESEND_REQUEST:
	send_multihop_request(resend->ifp,
	resend->prefix, resend->plen,
	resend->seqno, resend->id, 127);
	break;
	case RESEND_UPDATE:
	send_update(resend->ifp, 1,
	resend->prefix, resend->plen);
	break;
	default: abort();
	}
	resend->delay = MIN(0xFFFF, resend->delay * 2);
	resend->max--;
	}
	}
	resend = resend->next;
	}
	recompute_resend_time();
	}