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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 15:24:08 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 15:24:08 +0000 |
commit | f449f278dd3c70e479a035f50a9bb817a9b433ba (patch) | |
tree | 8ca2bfb785dda9bb4d573acdf9b42aea9cd51383 /src/libknot/rrtype/opt.c | |
parent | Initial commit. (diff) | |
download | knot-f449f278dd3c70e479a035f50a9bb817a9b433ba.tar.xz knot-f449f278dd3c70e479a035f50a9bb817a9b433ba.zip |
Adding upstream version 3.2.6.upstream/3.2.6upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | src/libknot/rrtype/opt.c | 687 |
1 files changed, 687 insertions, 0 deletions
diff --git a/src/libknot/rrtype/opt.c b/src/libknot/rrtype/opt.c new file mode 100644 index 0000000..294689c --- /dev/null +++ b/src/libknot/rrtype/opt.c @@ -0,0 +1,687 @@ +/* Copyright (C) 2022 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/>. + */ + +#include <assert.h> +#include <stdint.h> +#include <stdlib.h> +#include <string.h> +#include <netinet/in.h> +#include <sys/socket.h> + +#include "libknot/attribute.h" +#include "libknot/consts.h" +#include "libknot/descriptor.h" +#include "libknot/lookup.h" +#include "libknot/packet/pkt.h" +#include "libknot/rrtype/opt.h" +#include "contrib/mempattern.h" +#include "contrib/wire_ctx.h" + +/*! \brief Some implementation-related constants. */ +enum { + /*! \brief Byte offset of the extended RCODE field in TTL. */ + EDNS_OFFSET_RCODE = 0, + /*! \brief Byte offset of the version field in TTL. */ + EDNS_OFFSET_VERSION = 1, + + /*! \brief Byte offset of the family field in option data. */ + EDNS_OFFSET_CLIENT_SUBNET_FAMILY = 0, + /*! \brief Byte offset of the source mask field in option data. */ + EDNS_OFFSET_CLIENT_SUBNET_SRC_MASK = 2, + /*! \brief Byte offset of the destination mask field in option data. */ + EDNS_OFFSET_CLIENT_SUBNET_DST_MASK = 3, + /*! \brief Byte offset of the address field in option data. */ + EDNS_OFFSET_CLIENT_SUBNET_ADDR = 4, +}; + +_public_ +int knot_edns_init(knot_rrset_t *opt_rr, uint16_t max_pld, + uint8_t ext_rcode, uint8_t ver, knot_mm_t *mm) +{ + if (opt_rr == NULL) { + return KNOT_EINVAL; + } + + /* Initialize RRSet. */ + knot_dname_t *owner = knot_dname_copy((const uint8_t *)"", mm); + if (owner == NULL) { + return KNOT_ENOMEM; + } + + knot_rrset_init(opt_rr, owner, KNOT_RRTYPE_OPT, max_pld, 0); + + /* Create empty RDATA */ + int ret = knot_rrset_add_rdata(opt_rr, NULL, 0, mm); + if (ret == KNOT_EOK) { + knot_edns_set_ext_rcode(opt_rr, ext_rcode); + knot_edns_set_version(opt_rr, ver); + } + + return ret; +} + +_public_ +uint8_t knot_edns_get_ext_rcode(const knot_rrset_t *opt_rr) +{ + assert(opt_rr != NULL); + uint32_t ttl = 0; + wire_ctx_t w = wire_ctx_init((uint8_t *)&ttl, sizeof(ttl)); + // TTL is stored in machine byte order. Convert it to wire order first. + wire_ctx_write_u32(&w, opt_rr->ttl); + wire_ctx_set_offset(&w, EDNS_OFFSET_RCODE); + return wire_ctx_read_u8(&w); +} + +static void set_value_to_ttl(knot_rrset_t *opt_rr, size_t offset, uint8_t value) +{ + uint32_t ttl = 0; + wire_ctx_t w = wire_ctx_init((uint8_t *)&ttl, sizeof(ttl)); + // TTL is stored in machine byte order. Convert it to wire order first. + wire_ctx_write_u32(&w, opt_rr->ttl); + // Set the Extended RCODE in the converted TTL + wire_ctx_set_offset(&w, offset); + wire_ctx_write_u8(&w, value); + // Convert it back to machine byte order + wire_ctx_set_offset(&w, 0); + uint32_t ttl_local = wire_ctx_read_u32(&w); + // Store the TTL to the RDATA + opt_rr->ttl = ttl_local; +} + +_public_ +void knot_edns_set_ext_rcode(knot_rrset_t *opt_rr, uint8_t ext_rcode) +{ + assert(opt_rr != NULL); + set_value_to_ttl(opt_rr, EDNS_OFFSET_RCODE, ext_rcode); +} + +_public_ +uint8_t knot_edns_get_version(const knot_rrset_t *opt_rr) +{ + assert(opt_rr != NULL); + uint32_t ttl = 0; + wire_ctx_t w = wire_ctx_init((uint8_t *)&ttl, sizeof(ttl)); + // TTL is stored in machine byte order. Convert it to wire order first. + wire_ctx_write_u32(&w, opt_rr->ttl); + wire_ctx_set_offset(&w, EDNS_OFFSET_VERSION); + return wire_ctx_read_u8(&w); +} + +_public_ +void knot_edns_set_version(knot_rrset_t *opt_rr, uint8_t version) +{ + assert(opt_rr != NULL); + set_value_to_ttl(opt_rr, EDNS_OFFSET_VERSION, version); +} + +/*! + * \brief Add new EDNS option by replacing RDATA of OPT RR. + * + * \param opt OPT RR structure to add the Option to. + * \param code Option code. + * \param size Option data length in bytes. + * \param mm Memory context. + * + * \return Pointer to uninitialized option data. + */ +static uint8_t *edns_add(knot_rrset_t *opt, uint16_t code, uint16_t size, + knot_mm_t *mm) +{ + assert(opt->rrs.count == 1); + + // extract old RDATA + + uint8_t *old_data = opt->rrs.rdata->data; + uint16_t old_data_len = opt->rrs.rdata->len; + + // construct new RDATA + + uint16_t new_data_len = old_data_len + KNOT_EDNS_OPTION_HDRLEN + size; + uint8_t new_data[new_data_len]; + + wire_ctx_t wire = wire_ctx_init(new_data, new_data_len); + wire_ctx_write(&wire, old_data, old_data_len); + wire_ctx_write_u16(&wire, code); + wire_ctx_write_u16(&wire, size); + + // prepare EDNS option data + + size_t offset = wire_ctx_offset(&wire); + wire_ctx_clear(&wire, size); + + assert(wire_ctx_available(&wire) == 0); + assert(wire.error == KNOT_EOK); + + // replace RDATA + + knot_rdataset_clear(&opt->rrs, mm); + if (knot_rrset_add_rdata(opt, new_data, new_data_len, mm) != KNOT_EOK) { + return NULL; + } + + return opt->rrs.rdata->data + offset; +} + +_public_ +int knot_edns_reserve_option(knot_rrset_t *opt_rr, uint16_t code, + uint16_t size, uint8_t **wire_ptr, knot_mm_t *mm) +{ + if (!opt_rr) { + return KNOT_EINVAL; + } + + uint8_t *wire = edns_add(opt_rr, code, size, mm); + if (!wire) { + return KNOT_ENOMEM; + } + + if (wire_ptr) { + *wire_ptr = wire; + } + + return KNOT_EOK; +} + +_public_ +int knot_edns_add_option(knot_rrset_t *opt_rr, uint16_t code, + uint16_t size, const uint8_t *data, knot_mm_t *mm) +{ + if (!opt_rr || (size > 0 && !data)) { + return KNOT_EINVAL; + } + + uint8_t *wire = edns_add(opt_rr, code, size, mm); + if (!wire) { + return KNOT_ENOMEM; + } + + if (size > 0) { + memcpy(wire, data, size); + } + + return KNOT_EOK; +} + +_public_ +uint8_t *knot_edns_get_option(const knot_rrset_t *opt_rr, uint16_t code, + const uint8_t *previous) +{ + if (opt_rr == NULL) { + return NULL; + } + + knot_rdata_t *rdata = opt_rr->rrs.rdata; + if (rdata == NULL || rdata->len == 0) { + return NULL; + } + + wire_ctx_t wire = wire_ctx_init_const(rdata->data, rdata->len); + if (previous != NULL) { + if (previous < wire.wire) { + return NULL; + } + wire_ctx_set_offset(&wire, previous - wire.wire + 2); + uint16_t opt_len = wire_ctx_read_u16(&wire); + wire_ctx_skip(&wire, opt_len); + } + + while (wire_ctx_available(&wire) > 0 && wire.error == KNOT_EOK) { + uint8_t *pos = wire.position; + uint16_t opt_code = wire_ctx_read_u16(&wire); + uint16_t opt_len = wire_ctx_read_u16(&wire); + wire_ctx_skip(&wire, opt_len); + if (wire.error == KNOT_EOK && opt_code == code) { + return pos; + } + } + + return NULL; +} + +_public_ +int knot_edns_get_options(knot_rrset_t *opt_rr, knot_edns_options_t **out, + knot_mm_t *mm) +{ + if (opt_rr == NULL || opt_rr->rrs.count > 1 || out == NULL) { + return KNOT_EINVAL; + } + + knot_rdata_t *rdata = opt_rr->rrs.rdata; + if (rdata == NULL || rdata->len == 0) { + return KNOT_EOK; + } + + knot_edns_options_t *options = mm_calloc(mm, 1, sizeof(*options)); + + wire_ctx_t wire = wire_ctx_init_const(rdata->data, rdata->len); + + while (wire_ctx_available(&wire) > 0 && wire.error == KNOT_EOK) { + uint8_t *pos = wire.position; + uint16_t opt_code = wire_ctx_read_u16(&wire); + uint16_t opt_len = wire_ctx_read_u16(&wire); + wire_ctx_skip(&wire, opt_len); + if (wire.error == KNOT_EOK && opt_code <= KNOT_EDNS_MAX_OPTION_CODE) { + options->ptr[opt_code] = pos; + } + } + + if (wire.error != KNOT_EOK) { + mm_free(mm, options); + return wire.error; + } + + *out = options; + return KNOT_EOK; +} + +_public_ +int knot_edns_alignment_size(size_t current_pkt_size, + size_t current_opt_size, + size_t block_size) +{ + if (current_opt_size == 0 || block_size == 0) { + return -1; + } + + size_t current_size = current_pkt_size + current_opt_size; + if (current_size % block_size == 0) { + return -1; + } + + size_t modulo = (current_size + KNOT_EDNS_OPTION_HDRLEN) % block_size; + + return (modulo == 0) ? 0 : block_size - modulo; +} + +/*! + * \brief EDNS Client Subnet family data. + */ +typedef struct { + int platform; //!< Platform family identifier. + uint16_t iana; //!< IANA family identifier. + size_t offset; //!< Socket address offset. + size_t size; //!< Socket address size. +} ecs_family_t; + +#define ECS_INIT(platform, iana, type, member) \ + { platform, iana, offsetof(type, member), sizeof(((type *)0)->member) } + +/*! + * \brief Supported EDNS Client Subnet families. + * + * https://www.iana.org/assignments/address-family-numbers/address-family-numbers.xml + */ +static const ecs_family_t ECS_FAMILIES[] = { + ECS_INIT(AF_INET, KNOT_ADDR_FAMILY_IPV4, struct sockaddr_in, sin_addr), + ECS_INIT(AF_INET6, KNOT_ADDR_FAMILY_IPV6, struct sockaddr_in6, sin6_addr), + { 0 } +}; + +/*! + * \brief Lookup ECS family by platform identifier. + */ +static const ecs_family_t *ecs_family_by_platform(int family) +{ + for (const ecs_family_t *f = ECS_FAMILIES; f->size > 0; f++) { + if (f->platform == family) { + return f; + } + } + + return NULL; +} + +/*! + * \brief Lookup ECS family by IANA identifier. + */ +static const ecs_family_t *ecs_family_by_iana(uint16_t family) +{ + for (const ecs_family_t *f = ECS_FAMILIES; f->size > 0; f++) { + if (f->iana == family) { + return f; + } + } + + return NULL; +} + +/*! + * \brief Get ECS address prefix size in bytes. + */ +static uint16_t ecs_prefix_size(uint8_t prefix) +{ + return (prefix + 7) / 8; +} + +static uint8_t ecs_prefix_lsb_mask(uint8_t prefix) +{ + int modulo = prefix % 8; + if (modulo == 0) { + return 0xff; + } else { + return 0xff << (8 - modulo); + } +} + +/*! + * \brief Write raw network address prefix and clear the rest of the buffer. + */ +static void ecs_write_address(wire_ctx_t *dst, wire_ctx_t *src, int8_t prefix) +{ + size_t count = ecs_prefix_size(prefix); + uint8_t lsb_mask = ecs_prefix_lsb_mask(prefix); + + if (count > 0) { + wire_ctx_copy(dst, src, count); + if (dst->error != KNOT_EOK) { + return; + } + dst->position[-1] &= lsb_mask; + } + + size_t blank = wire_ctx_available(dst); + wire_ctx_clear(dst, blank); +} + +/*! + * \brief Check if ECS parameters are valid. + */ +static bool ecs_is_valid(const knot_edns_client_subnet_t *ecs) +{ + if (ecs == NULL) { + return false; + } + + const ecs_family_t *f = ecs_family_by_iana(ecs->family); + + return f != NULL && // known family check + (ecs->source_len <= f->size * 8) && // family address maximum check + (ecs->scope_len <= f->size * 8); // family address maximum check +} + +_public_ +uint16_t knot_edns_client_subnet_size(const knot_edns_client_subnet_t *ecs) +{ + if (!ecs_is_valid(ecs)) { + return 0; + } + + return sizeof(ecs->family) + + sizeof(ecs->source_len) + + sizeof(ecs->scope_len) + + ecs_prefix_size(ecs->source_len); +} + +_public_ +int knot_edns_client_subnet_write(uint8_t *option, uint16_t option_len, + const knot_edns_client_subnet_t *ecs) +{ + if (option == NULL || ecs == NULL) { + return KNOT_EINVAL; + } + + if (!ecs_is_valid(ecs)) { + return KNOT_EINVAL; + } + + wire_ctx_t wire = wire_ctx_init(option, option_len); + wire_ctx_t addr = wire_ctx_init_const(ecs->address, sizeof(ecs->address)); + + wire_ctx_write_u16(&wire, ecs->family); + wire_ctx_write_u8(&wire, ecs->source_len); + wire_ctx_write_u8(&wire, ecs->scope_len); + ecs_write_address(&wire, &addr, ecs->source_len); + + if (wire.error != KNOT_EOK) { + return wire.error; + } + + return KNOT_EOK; +} + +_public_ +int knot_edns_client_subnet_parse(knot_edns_client_subnet_t *ecs, + const uint8_t *option, uint16_t option_len) +{ + if (ecs == NULL || option == NULL) { + return KNOT_EINVAL; + } + + knot_edns_client_subnet_t result = { 0 }; + + wire_ctx_t wire = wire_ctx_init_const(option, option_len); + wire_ctx_t addr = wire_ctx_init(result.address, sizeof(result.address)); + + result.family = wire_ctx_read_u16(&wire); + result.source_len = wire_ctx_read_u8(&wire); + result.scope_len = wire_ctx_read_u8(&wire); + ecs_write_address(&addr, &wire, result.source_len); + + if (addr.error != KNOT_EOK || wire.error != KNOT_EOK) { + return KNOT_EMALF; + } + + if (!ecs_is_valid(&result)) { + return KNOT_EMALF; + } + + *ecs = result; + return KNOT_EOK; +} + +_public_ +int knot_edns_client_subnet_set_addr(knot_edns_client_subnet_t *ecs, + const struct sockaddr_storage *addr) +{ + if (ecs == NULL || addr == NULL) { + return KNOT_EINVAL; + } + + const ecs_family_t *f = ecs_family_by_platform(addr->ss_family); + if (f == NULL) { + return KNOT_ENOTSUP; + } + + ecs->family = f->iana; + ecs->source_len = f->size * 8; + ecs->scope_len = 0; + + wire_ctx_t dst = wire_ctx_init(ecs->address, sizeof(ecs->address)); + wire_ctx_t src = wire_ctx_init_const((uint8_t *)addr + f->offset, f->size); + ecs_write_address(&dst, &src, ecs->source_len); + + assert(dst.error == KNOT_EOK); + + return KNOT_EOK; +} + +_public_ +int knot_edns_client_subnet_get_addr(struct sockaddr_storage *addr, + const knot_edns_client_subnet_t *ecs) +{ + if (addr == NULL || ecs == NULL) { + return KNOT_EINVAL; + } + + const ecs_family_t *f = ecs_family_by_iana(ecs->family); + if (f == NULL) { + return KNOT_ENOTSUP; + } + + addr->ss_family = f->platform; + + wire_ctx_t dst = wire_ctx_init((uint8_t *)addr + f->offset, f->size); + wire_ctx_t src = wire_ctx_init_const(ecs->address, sizeof(ecs->address)); + ecs_write_address(&dst, &src, ecs->source_len); + + assert(dst.error == KNOT_EOK); + + return KNOT_EOK; +} + +_public_ +uint16_t knot_edns_keepalive_size(uint16_t timeout) +{ + return (timeout > 0) ? sizeof(uint16_t) : 0; +} + +_public_ +int knot_edns_keepalive_write(uint8_t *option, uint16_t option_len, uint16_t timeout) +{ + if (option == NULL) { + return KNOT_EINVAL; + } + + if (timeout == 0) { + return KNOT_EOK; + } + + wire_ctx_t wire = wire_ctx_init(option, option_len); + wire_ctx_write_u16(&wire, timeout); + + return wire.error; +} + +_public_ +int knot_edns_keepalive_parse(uint16_t *timeout, const uint8_t *option, + uint16_t option_len) +{ + if (timeout == NULL || option == NULL) { + return KNOT_EINVAL; + } + + *timeout = 0; + + if (option_len > 0) { + wire_ctx_t wire = wire_ctx_init_const(option, option_len); + *timeout = wire_ctx_read_u16(&wire); + + if (wire.error != KNOT_EOK) { + return KNOT_EMALF; + } + } + + return KNOT_EOK; +} + +_public_ +uint16_t knot_edns_chain_size(const knot_dname_t *point) +{ + return knot_dname_size(point); +} + +_public_ +int knot_edns_chain_write(uint8_t *option, uint16_t option_len, + const knot_dname_t *point) +{ + if (option == NULL || point == NULL) { + return KNOT_EINVAL; + } + + wire_ctx_t wire = wire_ctx_init(option, option_len); + wire_ctx_write(&wire, point, knot_dname_size(point)); + + return wire.error; +} + +_public_ +int knot_edns_chain_parse(knot_dname_t **point, const uint8_t *option, + uint16_t option_len, knot_mm_t *mm) +{ + if (point == NULL || option == NULL) { + return KNOT_EINVAL; + } + + int ret = knot_dname_wire_check(option, option + option_len, NULL); + if (ret <= 0) { + return KNOT_EMALF; + } + + *point = knot_dname_copy(option, mm); + if (*point == NULL) { + return KNOT_ENOMEM; + } + + return KNOT_EOK; +} + +_public_ +uint16_t knot_edns_cookie_size(const knot_edns_cookie_t *cc, + const knot_edns_cookie_t *sc) +{ + if (cc == NULL || cc->len != KNOT_EDNS_COOKIE_CLNT_SIZE) { + return 0; + } else if (sc == NULL || sc->len == 0) { + return KNOT_EDNS_COOKIE_CLNT_SIZE; + } else if (sc->len < KNOT_EDNS_COOKIE_SRVR_MIN_SIZE || + sc->len > KNOT_EDNS_COOKIE_SRVR_MAX_SIZE) { + return 0; + } else { + return cc->len + sc->len; + } +} + +_public_ +int knot_edns_cookie_write(uint8_t *option, uint16_t option_len, + const knot_edns_cookie_t *cc, + const knot_edns_cookie_t *sc) +{ + if (option == NULL || cc == NULL || cc->len != KNOT_EDNS_COOKIE_CLNT_SIZE) { + return KNOT_EINVAL; + } + + wire_ctx_t wire = wire_ctx_init(option, option_len); + wire_ctx_write(&wire, cc->data, cc->len); + + if (sc != NULL && sc->len > 0) { + if (sc->len < KNOT_EDNS_COOKIE_SRVR_MIN_SIZE || + sc->len > KNOT_EDNS_COOKIE_SRVR_MAX_SIZE) { + return KNOT_EINVAL; + } + wire_ctx_write(&wire, sc->data, sc->len); + } + + return wire.error; +} + +_public_ +int knot_edns_cookie_parse(knot_edns_cookie_t *cc, knot_edns_cookie_t *sc, + const uint8_t *option, uint16_t option_len) +{ + if (cc == NULL || sc == NULL || option == NULL) { + return KNOT_EINVAL; + } + + if (option_len != KNOT_EDNS_COOKIE_CLNT_SIZE && + (option_len < KNOT_EDNS_COOKIE_CLNT_SIZE + KNOT_EDNS_COOKIE_SRVR_MIN_SIZE || + option_len > KNOT_EDNS_COOKIE_CLNT_SIZE + KNOT_EDNS_COOKIE_SRVR_MAX_SIZE)) { + return KNOT_EMALF; + } + assert(option_len >= KNOT_EDNS_COOKIE_CLNT_SIZE); + + memcpy(cc->data, option, KNOT_EDNS_COOKIE_CLNT_SIZE); + cc->len = KNOT_EDNS_COOKIE_CLNT_SIZE; + + size_t sc_len = option_len - KNOT_EDNS_COOKIE_CLNT_SIZE; + if (sc_len == 0) { + sc->len = 0; + } else { + memcpy(sc->data, option + KNOT_EDNS_COOKIE_CLNT_SIZE, sc_len); + sc->len = sc_len; + } + + return KNOT_EOK; +} |