Annotation of embedaddon/quagga/babeld/resend.c, revision 1.1.1.1

1.1       misho       1: /*  
                      2:  *  This file is free software: you may copy, redistribute and/or modify it  
                      3:  *  under the terms of the GNU General Public License as published by the  
                      4:  *  Free Software Foundation, either version 2 of the License, or (at your  
                      5:  *  option) any later version.  
                      6:  *  
                      7:  *  This file is distributed in the hope that it will be useful, but  
                      8:  *  WITHOUT ANY WARRANTY; without even the implied warranty of  
                      9:  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU  
                     10:  *  General Public License for more details.  
                     11:  *  
                     12:  *  You should have received a copy of the GNU General Public License  
                     13:  *  along with this program.  If not, see <http://www.gnu.org/licenses/>.  
                     14:  *  
                     15:  * This file incorporates work covered by the following copyright and  
                     16:  * permission notice:  
                     17:  *  
                     18: Copyright (c) 2007, 2008 by Juliusz Chroboczek
                     19: 
                     20: Permission is hereby granted, free of charge, to any person obtaining a copy
                     21: of this software and associated documentation files (the "Software"), to deal
                     22: in the Software without restriction, including without limitation the rights
                     23: to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
                     24: copies of the Software, and to permit persons to whom the Software is
                     25: furnished to do so, subject to the following conditions:
                     26: 
                     27: The above copyright notice and this permission notice shall be included in
                     28: all copies or substantial portions of the Software.
                     29: 
                     30: THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
                     31: IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
                     32: FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
                     33: AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
                     34: LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
                     35: OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
                     36: THE SOFTWARE.
                     37: */
                     38: 
                     39: #include <sys/time.h>
                     40: #include <time.h>
                     41: #include <string.h>
                     42: #include <stdlib.h>
                     43: 
                     44: #include <zebra.h>
                     45: #include "if.h"
                     46: 
                     47: #include "babel_main.h"
                     48: #include "babeld.h"
                     49: #include "util.h"
                     50: #include "neighbour.h"
                     51: #include "resend.h"
                     52: #include "message.h"
                     53: #include "babel_interface.h"
                     54: 
                     55: struct timeval resend_time = {0, 0};
                     56: struct resend *to_resend = NULL;
                     57: 
                     58: static int
                     59: resend_match(struct resend *resend,
                     60:              int kind, const unsigned char *prefix, unsigned char plen)
                     61: {
                     62:     return (resend->kind == kind &&
                     63:             resend->plen == plen && memcmp(resend->prefix, prefix, 16) == 0);
                     64: }
                     65: 
                     66: /* This is called by neigh.c when a neighbour is flushed */
                     67: 
                     68: void
                     69: flush_resends(struct neighbour *neigh)
                     70: {
                     71:     /* Nothing for now */
                     72: }
                     73: 
                     74: static struct resend *
                     75: find_resend(int kind, const unsigned char *prefix, unsigned char plen,
                     76:              struct resend **previous_return)
                     77: {
                     78:     struct resend *current, *previous;
                     79: 
                     80:     previous = NULL;
                     81:     current = to_resend;
                     82:     while(current) {
                     83:         if(resend_match(current, kind, prefix, plen)) {
                     84:             if(previous_return)
                     85:                 *previous_return = previous;
                     86:             return current;
                     87:         }
                     88:         previous = current;
                     89:         current = current->next;
                     90:     }
                     91: 
                     92:     return NULL;
                     93: }
                     94: 
                     95: struct resend *
                     96: find_request(const unsigned char *prefix, unsigned char plen,
                     97:              struct resend **previous_return)
                     98: {
                     99:     return find_resend(RESEND_REQUEST, prefix, plen, previous_return);
                    100: }
                    101: 
                    102: int
                    103: record_resend(int kind, const unsigned char *prefix, unsigned char plen,
                    104:               unsigned short seqno, const unsigned char *id,
                    105:               struct interface *ifp, int delay)
                    106: {
                    107:     struct resend *resend;
                    108:     unsigned int ifindex = ifp ? ifp->ifindex : 0;
                    109: 
                    110:     if((kind == RESEND_REQUEST &&
                    111:         input_filter(NULL, prefix, plen, NULL, ifindex) >= INFINITY) ||
                    112:        (kind == RESEND_UPDATE &&
                    113:         output_filter(NULL, prefix, plen, ifindex) >= INFINITY))
                    114:         return 0;
                    115: 
                    116:     if(delay >= 0xFFFF)
                    117:         delay = 0xFFFF;
                    118: 
                    119:     resend = find_resend(kind, prefix, plen, NULL);
                    120:     if(resend) {
                    121:         if(resend->delay && delay)
                    122:             resend->delay = MIN(resend->delay, delay);
                    123:         else if(delay)
                    124:             resend->delay = delay;
                    125:         resend->time = babel_now;
                    126:         resend->max = RESEND_MAX;
                    127:         if(id && memcmp(resend->id, id, 8) == 0 &&
                    128:            seqno_compare(resend->seqno, seqno) > 0) {
                    129:             return 0;
                    130:         }
                    131:         if(id)
                    132:             memcpy(resend->id, id, 8);
                    133:         else
                    134:             memset(resend->id, 0, 8);
                    135:         resend->seqno = seqno;
                    136:         if(resend->ifp != ifp)
                    137:             resend->ifp = NULL;
                    138:     } else {
                    139:         resend = malloc(sizeof(struct resend));
                    140:         if(resend == NULL)
                    141:             return -1;
                    142:         resend->kind = kind;
                    143:         resend->max = RESEND_MAX;
                    144:         resend->delay = delay;
                    145:         memcpy(resend->prefix, prefix, 16);
                    146:         resend->plen = plen;
                    147:         resend->seqno = seqno;
                    148:         if(id)
                    149:             memcpy(resend->id, id, 8);
                    150:         else
                    151:             memset(resend->id, 0, 8);
                    152:         resend->ifp = ifp;
                    153:         resend->time = babel_now;
                    154:         resend->next = to_resend;
                    155:         to_resend = resend;
                    156:     }
                    157: 
                    158:     if(resend->delay) {
                    159:         struct timeval timeout;
                    160:         timeval_add_msec(&timeout, &resend->time, resend->delay);
                    161:         timeval_min(&resend_time, &timeout);
                    162:     }
                    163:     return 1;
                    164: }
                    165: 
                    166: static int
                    167: resend_expired(struct resend *resend)
                    168: {
                    169:     switch(resend->kind) {
                    170:     case RESEND_REQUEST:
                    171:         return timeval_minus_msec(&babel_now, &resend->time) >= REQUEST_TIMEOUT;
                    172:     default:
                    173:         return resend->max <= 0;
                    174:     }
                    175: }
                    176: 
                    177: int
                    178: unsatisfied_request(const unsigned char *prefix, unsigned char plen,
                    179:                     unsigned short seqno, const unsigned char *id)
                    180: {
                    181:     struct resend *request;
                    182: 
                    183:     request = find_request(prefix, plen, NULL);
                    184:     if(request == NULL || resend_expired(request))
                    185:         return 0;
                    186: 
                    187:     if(memcmp(request->id, id, 8) != 0 ||
                    188:        seqno_compare(request->seqno, seqno) <= 0)
                    189:         return 1;
                    190: 
                    191:     return 0;
                    192: }
                    193: 
                    194: /* Determine whether a given request should be forwarded. */
                    195: int
                    196: request_redundant(struct interface *ifp,
                    197:                   const unsigned char *prefix, unsigned char plen,
                    198:                   unsigned short seqno, const unsigned char *id)
                    199: {
                    200:     struct resend *request;
                    201: 
                    202:     request = find_request(prefix, plen, NULL);
                    203:     if(request == NULL || resend_expired(request))
                    204:         return 0;
                    205: 
                    206:     if(memcmp(request->id, id, 8) == 0 &&
                    207:        seqno_compare(request->seqno, seqno) > 0)
                    208:         return 0;
                    209: 
                    210:     if(request->ifp != NULL && request->ifp != ifp)
                    211:         return 0;
                    212: 
                    213:     if(request->max > 0)
                    214:         /* Will be resent. */
                    215:         return 1;
                    216: 
                    217:     if(timeval_minus_msec(&babel_now, &request->time) <
                    218:        (ifp ? MIN(babel_get_if_nfo(ifp)->hello_interval, 1000) : 1000))
                    219:         /* Fairly recent. */
                    220:         return 1;
                    221: 
                    222:     return 0;
                    223: }
                    224: 
                    225: int
                    226: satisfy_request(const unsigned char *prefix, unsigned char plen,
                    227:                 unsigned short seqno, const unsigned char *id,
                    228:                 struct interface *ifp)
                    229: {
                    230:     struct resend *request, *previous;
                    231: 
                    232:     request = find_request(prefix, plen, &previous);
                    233:     if(request == NULL)
                    234:         return 0;
                    235: 
                    236:     if(ifp != NULL && request->ifp != ifp)
                    237:         return 0;
                    238: 
                    239:     if(memcmp(request->id, id, 8) != 0 ||
                    240:        seqno_compare(request->seqno, seqno) <= 0) {
                    241:         /* We cannot remove the request, as we may be walking the list right
                    242:            now.  Mark it as expired, so that expire_resend will remove it. */
                    243:         request->max = 0;
                    244:         request->time.tv_sec = 0;
                    245:         recompute_resend_time();
                    246:         return 1;
                    247:     }
                    248: 
                    249:     return 0;
                    250: }
                    251: 
                    252: void
                    253: expire_resend()
                    254: {
                    255:     struct resend *current, *previous;
                    256:     int recompute = 0;
                    257: 
                    258:     previous = NULL;
                    259:     current = to_resend;
                    260:     while(current) {
                    261:         if(resend_expired(current)) {
                    262:             if(previous == NULL) {
                    263:                 to_resend = current->next;
                    264:                 free(current);
                    265:                 current = to_resend;
                    266:             } else {
                    267:                 previous->next = current->next;
                    268:                 free(current);
                    269:                 current = previous->next;
                    270:             }
                    271:             recompute = 1;
                    272:         } else {
                    273:             previous = current;
                    274:             current = current->next;
                    275:         }
                    276:     }
                    277:     if(recompute)
                    278:         recompute_resend_time();
                    279: }
                    280: 
                    281: void
                    282: recompute_resend_time()
                    283: {
                    284:     struct resend *request;
                    285:     struct timeval resend = {0, 0};
                    286: 
                    287:     request = to_resend;
                    288:     while(request) {
                    289:         if(!resend_expired(request) && request->delay > 0 && request->max > 0) {
                    290:             struct timeval timeout;
                    291:             timeval_add_msec(&timeout, &request->time, request->delay);
                    292:             timeval_min(&resend, &timeout);
                    293:         }
                    294:         request = request->next;
                    295:     }
                    296: 
                    297:     resend_time = resend;
                    298: }
                    299: 
                    300: void
                    301: do_resend()
                    302: {
                    303:     struct resend *resend;
                    304: 
                    305:     resend = to_resend;
                    306:     while(resend) {
                    307:         if(!resend_expired(resend) && resend->delay > 0 && resend->max > 0) {
                    308:             struct timeval timeout;
                    309:             timeval_add_msec(&timeout, &resend->time, resend->delay);
                    310:             if(timeval_compare(&babel_now, &timeout) >= 0) {
                    311:                 switch(resend->kind) {
                    312:                 case RESEND_REQUEST:
                    313:                     send_multihop_request(resend->ifp,
                    314:                                           resend->prefix, resend->plen,
                    315:                                           resend->seqno, resend->id, 127);
                    316:                     break;
                    317:                 case RESEND_UPDATE:
                    318:                     send_update(resend->ifp, 1,
                    319:                                 resend->prefix, resend->plen);
                    320:                     break;
                    321:                 default: abort();
                    322:                 }
                    323:                 resend->delay = MIN(0xFFFF, resend->delay * 2);
                    324:                 resend->max--;
                    325:             }
                    326:         }
                    327:         resend = resend->next;
                    328:     }
                    329:     recompute_resend_time();
                    330: }

FreeBSD-CVSweb <freebsd-cvsweb@FreeBSD.org>