diff options
Diffstat (limited to 'external/unbound/daemon/worker.c')
| -rw-r--r-- | external/unbound/daemon/worker.c | 38 |
1 files changed, 32 insertions, 6 deletions
diff --git a/external/unbound/daemon/worker.c b/external/unbound/daemon/worker.c index 93481354f..f4e87289a 100644 --- a/external/unbound/daemon/worker.c +++ b/external/unbound/daemon/worker.c @@ -86,6 +86,8 @@ /** Size of an UDP datagram */ #define NORMAL_UDP_SIZE 512 /* bytes */ +/** ratelimit for error responses */ +#define ERROR_RATELIMIT 100 /* qps */ /** * seconds to add to prefetch leeway. This is a TTL that expires old rrsets @@ -291,6 +293,26 @@ worker_handle_service_reply(struct comm_point* c, void* arg, int error, return 0; } +/** ratelimit error replies + * @param worker: the worker struct with ratelimit counter + * @param err: error code that would be wanted. + * @return value of err if okay, or -1 if it should be discarded instead. + */ +static int +worker_err_ratelimit(struct worker* worker, int err) +{ + if(worker->err_limit_time == *worker->env.now) { + /* see if limit is exceeded for this second */ + if(worker->err_limit_count++ > ERROR_RATELIMIT) + return -1; + } else { + /* new second, new limits */ + worker->err_limit_time = *worker->env.now; + worker->err_limit_count = 1; + } + return err; +} + /** check request sanity. * @param pkt: the wire packet to examine for sanity. * @param worker: parameters for checking. @@ -315,32 +337,32 @@ worker_check_request(sldns_buffer* pkt, struct worker* worker) if(LDNS_TC_WIRE(sldns_buffer_begin(pkt))) { LDNS_TC_CLR(sldns_buffer_begin(pkt)); verbose(VERB_QUERY, "request bad, has TC bit on"); - return LDNS_RCODE_FORMERR; + return worker_err_ratelimit(worker, LDNS_RCODE_FORMERR); } if(LDNS_OPCODE_WIRE(sldns_buffer_begin(pkt)) != LDNS_PACKET_QUERY) { verbose(VERB_QUERY, "request unknown opcode %d", LDNS_OPCODE_WIRE(sldns_buffer_begin(pkt))); - return LDNS_RCODE_NOTIMPL; + return worker_err_ratelimit(worker, LDNS_RCODE_NOTIMPL); } if(LDNS_QDCOUNT(sldns_buffer_begin(pkt)) != 1) { verbose(VERB_QUERY, "request wrong nr qd=%d", LDNS_QDCOUNT(sldns_buffer_begin(pkt))); - return LDNS_RCODE_FORMERR; + return worker_err_ratelimit(worker, LDNS_RCODE_FORMERR); } if(LDNS_ANCOUNT(sldns_buffer_begin(pkt)) != 0) { verbose(VERB_QUERY, "request wrong nr an=%d", LDNS_ANCOUNT(sldns_buffer_begin(pkt))); - return LDNS_RCODE_FORMERR; + return worker_err_ratelimit(worker, LDNS_RCODE_FORMERR); } if(LDNS_NSCOUNT(sldns_buffer_begin(pkt)) != 0) { verbose(VERB_QUERY, "request wrong nr ns=%d", LDNS_NSCOUNT(sldns_buffer_begin(pkt))); - return LDNS_RCODE_FORMERR; + return worker_err_ratelimit(worker, LDNS_RCODE_FORMERR); } if(LDNS_ARCOUNT(sldns_buffer_begin(pkt)) > 1) { verbose(VERB_QUERY, "request wrong nr ar=%d", LDNS_ARCOUNT(sldns_buffer_begin(pkt))); - return LDNS_RCODE_FORMERR; + return worker_err_ratelimit(worker, LDNS_RCODE_FORMERR); } return 0; } @@ -813,6 +835,10 @@ worker_handle_request(struct comm_point* c, void* arg, int error, if(!query_info_parse(&qinfo, c->buffer)) { verbose(VERB_ALGO, "worker parse request: formerror."); log_addr(VERB_CLIENT,"from",&repinfo->addr, repinfo->addrlen); + if(worker_err_ratelimit(worker, LDNS_RCODE_FORMERR) == -1) { + comm_point_drop_reply(repinfo); + return 0; + } sldns_buffer_rewind(c->buffer); LDNS_QR_SET(sldns_buffer_begin(c->buffer)); LDNS_RCODE_SET(sldns_buffer_begin(c->buffer), |