diff options
Diffstat (limited to '')
| -rw-r--r-- | lib/cache/knot_pkt.c | 106 |
1 files changed, 106 insertions, 0 deletions
diff --git a/lib/cache/knot_pkt.c b/lib/cache/knot_pkt.c new file mode 100644 index 0000000..56836a6 --- /dev/null +++ b/lib/cache/knot_pkt.c @@ -0,0 +1,106 @@ +/* Copyright (C) 2017 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz> + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + This program 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 <https://www.gnu.org/licenses/>. + */ + +/** @file + * Implementation of preparing knot_pkt_t for filling with RRs. + * Prototypes in ./impl.h + */ + +#include "lib/cache/impl.h" + +int pkt_renew(knot_pkt_t *pkt, const knot_dname_t *name, uint16_t type) +{ + /* Update packet question if needed. */ + if (!knot_dname_is_equal(knot_pkt_qname(pkt), name) + || knot_pkt_qtype(pkt) != type || knot_pkt_qclass(pkt) != KNOT_CLASS_IN) { + int ret = kr_pkt_recycle(pkt); + if (ret) return kr_error(ret); + ret = knot_pkt_put_question(pkt, name, KNOT_CLASS_IN, type); + if (ret) return kr_error(ret); + } + + pkt->parsed = pkt->size = PKT_SIZE_NOWIRE; + knot_wire_set_qr(pkt->wire); + knot_wire_set_aa(pkt->wire); + return kr_ok(); +} + +/** Reserve space for additional `count` RRsets. + * \note pkt->rr_info gets correct length but is always zeroed + */ +static int pkt_alloc_space(knot_pkt_t *pkt, int count) +{ + size_t allocd_orig = pkt->rrset_allocd; + if (pkt->rrset_count + count <= allocd_orig) { + return kr_ok(); + } + /* A simple growth strategy, amortized O(count). */ + pkt->rrset_allocd = MAX( + pkt->rrset_count + count, + pkt->rrset_count + allocd_orig); + + pkt->rr = mm_realloc(&pkt->mm, pkt->rr, + sizeof(pkt->rr[0]) * pkt->rrset_allocd, + sizeof(pkt->rr[0]) * allocd_orig); + if (!pkt->rr) { + return kr_error(ENOMEM); + } + /* Allocate pkt->rr_info to be certain, but just leave it zeroed. */ + mm_free(&pkt->mm, pkt->rr_info); + pkt->rr_info = mm_alloc(&pkt->mm, sizeof(pkt->rr_info[0]) * pkt->rrset_allocd); + if (!pkt->rr_info) { + return kr_error(ENOMEM); + } + memset(pkt->rr_info, 0, sizeof(pkt->rr_info[0]) * pkt->rrset_allocd); + return kr_ok(); +} + +int pkt_append(knot_pkt_t *pkt, const struct answer_rrset *rrset, uint8_t rank) +{ + /* allocate space, to be sure */ + int rrset_cnt = (rrset->set.rr->rrs.count > 0) + (rrset->sig_rds.count > 0); + int ret = pkt_alloc_space(pkt, rrset_cnt); + if (ret) return kr_error(ret); + /* write both sets */ + const knot_rdataset_t *rdss[2] = { &rrset->set.rr->rrs, &rrset->sig_rds }; + for (int i = 0; i < rrset_cnt; ++i) { + assert(rdss[i]->count); + /* allocate rank */ + uint8_t *rr_rank = mm_alloc(&pkt->mm, sizeof(*rr_rank)); + if (!rr_rank) return kr_error(ENOMEM); + *rr_rank = (i == 0) ? rank : (KR_RANK_OMIT | KR_RANK_AUTH); + /* rank for RRSIGs isn't really useful: ^^ */ + if (i == 0) { + pkt->rr[pkt->rrset_count] = *rrset->set.rr; + pkt->rr[pkt->rrset_count].additional = rr_rank; + } else { + /* append the RR array */ + pkt->rr[pkt->rrset_count] = (knot_rrset_t){ + .owner = knot_dname_copy(rrset->set.rr->owner, &pkt->mm), + /* ^^ well, another copy isn't really needed */ + .ttl = rrset->set.rr->ttl, + .type = KNOT_RRTYPE_RRSIG, + .rclass = KNOT_CLASS_IN, + .rrs = *rdss[i], + .additional = rr_rank, + }; + } + ++pkt->rrset_count; + ++(pkt->sections[pkt->current].count); + } + return kr_ok(); +} + |