[mirror_frr.git] / babeld / resend.c

/*
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.
*/

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#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(void)
{
    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(void)
{
    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(void)
{
    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();
}
Commit	Line	Data
ca10883e DS	1	/*
	2	Copyright (c) 2007, 2008 by Juliusz Chroboczek
	3
	4	Permission is hereby granted, free of charge, to any person obtaining a copy
	5	of this software and associated documentation files (the "Software"), to deal
	6	in the Software without restriction, including without limitation the rights
	7	to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	8	copies of the Software, and to permit persons to whom the Software is
	9	furnished to do so, subject to the following conditions:
	10
	11	The above copyright notice and this permission notice shall be included in
	12	all copies or substantial portions of the Software.
	13
	14	THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	15	IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	16	FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
	17	AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	18	LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
	19	OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
	20	THE SOFTWARE.
	21	*/
	22
b45ac5f5 DL	23	#ifdef HAVE_CONFIG_H
	24	#include "config.h"
	25	#endif
	26
ca10883e DS	27	#include <sys/time.h>
	28	#include <time.h>
	29	#include <string.h>
	30	#include <stdlib.h>
	31
	32	#include <zebra.h>
	33	#include "if.h"
	34
	35	#include "babel_main.h"
	36	#include "babeld.h"
	37	#include "util.h"
	38	#include "neighbour.h"
	39	#include "resend.h"
	40	#include "message.h"
	41	#include "babel_interface.h"
	42
	43	struct timeval resend_time = {0, 0};
	44	struct resend *to_resend = NULL;
	45
	46	static int
	47	resend_match(struct resend *resend,
	48	int kind, const unsigned char *prefix, unsigned char plen)
	49	{
	50	return (resend->kind == kind &&
	51	resend->plen == plen && memcmp(resend->prefix, prefix, 16) == 0);
	52	}
	53
	54	/* This is called by neigh.c when a neighbour is flushed */
	55
	56	void
	57	flush_resends(struct neighbour *neigh)
	58	{
	59	/* Nothing for now */
	60	}
	61
	62	static struct resend *
	63	find_resend(int kind, const unsigned char *prefix, unsigned char plen,
	64	struct resend **previous_return)
	65	{
	66	struct resend current, previous;
	67
	68	previous = NULL;
	69	current = to_resend;
	70	while(current) {
	71	if(resend_match(current, kind, prefix, plen)) {
	72	if(previous_return)
	73	*previous_return = previous;
	74	return current;
	75	}
	76	previous = current;
	77	current = current->next;
	78	}
	79
	80	return NULL;
	81	}
	82
	83	struct resend *
	84	find_request(const unsigned char *prefix, unsigned char plen,
	85	struct resend **previous_return)
	86	{
	87	return find_resend(RESEND_REQUEST, prefix, plen, previous_return);
	88	}
	89
	90	int
91	record_resend(int kind, const unsigned char *prefix, unsigned char plen,
92	unsigned short seqno, const unsigned char *id,
93	struct interface *ifp, int delay)
94	{
95	struct resend *resend;
96	unsigned int ifindex = ifp ? ifp->ifindex : 0;
97
98	if((kind == RESEND_REQUEST &&
99	input_filter(NULL, prefix, plen, NULL, ifindex) >= INFINITY) \|\|
100	(kind == RESEND_UPDATE &&
101	output_filter(NULL, prefix, plen, ifindex) >= INFINITY))
102	return 0;
103
104	if(delay >= 0xFFFF)
105	delay = 0xFFFF;
106
107	resend = find_resend(kind, prefix, plen, NULL);
108	if(resend) {
109	if(resend->delay && delay)
110	resend->delay = MIN(resend->delay, delay);
111	else if(delay)
112	resend->delay = delay;
113	resend->time = babel_now;
114	resend->max = RESEND_MAX;
115	if(id && memcmp(resend->id, id, 8) == 0 &&
116	seqno_compare(resend->seqno, seqno) > 0) {
117	return 0;
118	}
119	if(id)
120	memcpy(resend->id, id, 8);
121	else
122	memset(resend->id, 0, 8);
123	resend->seqno = seqno;
124	if(resend->ifp != ifp)
125	resend->ifp = NULL;
126	} else {
127	resend = malloc(sizeof(struct resend));
128	if(resend == NULL)
129	return -1;
130	resend->kind = kind;
131	resend->max = RESEND_MAX;
132	resend->delay = delay;
133	memcpy(resend->prefix, prefix, 16);
134	resend->plen = plen;
135	resend->seqno = seqno;
136	if(id)
137	memcpy(resend->id, id, 8);
138	else
139	memset(resend->id, 0, 8);
140	resend->ifp = ifp;
141	resend->time = babel_now;
142	resend->next = to_resend;
143	to_resend = resend;
144	}
145
146	if(resend->delay) {
147	struct timeval timeout;
148	timeval_add_msec(&timeout, &resend->time, resend->delay);
149	timeval_min(&resend_time, &timeout);
150	}
151	return 1;
152	}
153
154	static int
155	resend_expired(struct resend *resend)
156	{
157	switch(resend->kind) {
158	case RESEND_REQUEST:
159	return timeval_minus_msec(&babel_now, &resend->time) >= REQUEST_TIMEOUT;
160	default:
161	return resend->max <= 0;
162	}
163	}
164
165	int
166	unsatisfied_request(const unsigned char *prefix, unsigned char plen,
167	unsigned short seqno, const unsigned char *id)
168	{
169	struct resend *request;
170
171	request = find_request(prefix, plen, NULL);
172	if(request == NULL \|\| resend_expired(request))
173	return 0;
174
175	if(memcmp(request->id, id, 8) != 0 \|\|
176	seqno_compare(request->seqno, seqno) <= 0)
177	return 1;
178
179	return 0;
180	}
181
182	/* Determine whether a given request should be forwarded. */
183	int
184	request_redundant(struct interface *ifp,
185	const unsigned char *prefix, unsigned char plen,
186	unsigned short seqno, const unsigned char *id)
187	{
188	struct resend *request;
189
190	request = find_request(prefix, plen, NULL);
191	if(request == NULL \|\| resend_expired(request))
192	return 0;
193
194	if(memcmp(request->id, id, 8) == 0 &&
195	seqno_compare(request->seqno, seqno) > 0)
196	return 0;
197
198	if(request->ifp != NULL && request->ifp != ifp)
199	return 0;
200
201	if(request->max > 0)
202	/* Will be resent. */
203	return 1;
204
205	if(timeval_minus_msec(&babel_now, &request->time) <
206	(ifp ? MIN(babel_get_if_nfo(ifp)->hello_interval, 1000) : 1000))
207	/* Fairly recent. */
208	return 1;
209
210	return 0;
211	}
212
213	int
214	satisfy_request(const unsigned char *prefix, unsigned char plen,
215	unsigned short seqno, const unsigned char *id,
216	struct interface *ifp)
217	{
218	struct resend request, previous;
219
220	request = find_request(prefix, plen, &previous);
221	if(request == NULL)
222	return 0;
223
224	if(ifp != NULL && request->ifp != ifp)
225	return 0;
226
227	if(memcmp(request->id, id, 8) != 0 \|\|
228	seqno_compare(request->seqno, seqno) <= 0) {
229	/* We cannot remove the request, as we may be walking the list right
230	now. Mark it as expired, so that expire_resend will remove it. */
231	request->max = 0;
232	request->time.tv_sec = 0;
233	recompute_resend_time();
234	return 1;
235	}
236
237	return 0;
238	}
239
240	void
4d762f26	241	expire_resend(void)
ca10883e DS	242	{
	243	struct resend current, previous;
	244	int recompute = 0;
	245
	246	previous = NULL;
	247	current = to_resend;
	248	while(current) {
	249	if(resend_expired(current)) {
	250	if(previous == NULL) {
	251	to_resend = current->next;
	252	free(current);
	253	current = to_resend;
	254	} else {
	255	previous->next = current->next;
	256	free(current);
	257	current = previous->next;
	258	}
	259	recompute = 1;
	260	} else {
	261	previous = current;
	262	current = current->next;
	263	}
	264	}
	265	if(recompute)
	266	recompute_resend_time();
	267	}
	268
	269	void
4d762f26	270	recompute_resend_time(void)
ca10883e DS	271	{
	272	struct resend *request;
	273	struct timeval resend = {0, 0};
	274
	275	request = to_resend;
	276	while(request) {
	277	if(!resend_expired(request) && request->delay > 0 && request->max > 0) {
	278	struct timeval timeout;
	279	timeval_add_msec(&timeout, &request->time, request->delay);
	280	timeval_min(&resend, &timeout);
	281	}
	282	request = request->next;
	283	}
	284
	285	resend_time = resend;
	286	}
	287
	288	void
4d762f26	289	do_resend(void)
ca10883e DS	290	{
	291	struct resend *resend;
	292
	293	resend = to_resend;
	294	while(resend) {
	295	if(!resend_expired(resend) && resend->delay > 0 && resend->max > 0) {
	296	struct timeval timeout;
	297	timeval_add_msec(&timeout, &resend->time, resend->delay);
	298	if(timeval_compare(&babel_now, &timeout) >= 0) {
	299	switch(resend->kind) {
	300	case RESEND_REQUEST:
	301	send_multihop_request(resend->ifp,
	302	resend->prefix, resend->plen,
	303	resend->seqno, resend->id, 127);
	304	break;
	305	case RESEND_UPDATE:
	306	send_update(resend->ifp, 1,
	307	resend->prefix, resend->plen);
	308	break;
	309	default: abort();
	310	}
	311	resend->delay = MIN(0xFFFF, resend->delay * 2);
	312	resend->max--;
	313	}
	314	}
	315	resend = resend->next;
	316	}
	317	recompute_resend_time();
	318	}