diff options
Diffstat (limited to 'babeld/resend.c')
| -rw-r--r-- | babeld/resend.c | 301 |
1 files changed, 301 insertions, 0 deletions
diff --git a/babeld/resend.c b/babeld/resend.c new file mode 100644 index 0000000..254faac --- /dev/null +++ b/babeld/resend.c @@ -0,0 +1,301 @@ +// SPDX-License-Identifier: MIT +/* +Copyright (c) 2007, 2008 by Juliusz Chroboczek +*/ + +#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(); +} |