diff options
Diffstat (limited to 'lib/addns/dnsrecord.c')
| -rw-r--r-- | lib/addns/dnsrecord.c | 475 |
1 files changed, 475 insertions, 0 deletions
diff --git a/lib/addns/dnsrecord.c b/lib/addns/dnsrecord.c new file mode 100644 index 0000000..e6e205e --- /dev/null +++ b/lib/addns/dnsrecord.c @@ -0,0 +1,475 @@ +/* + Linux DNS client library implementation + Copyright (C) 2006 Krishna Ganugapati <krishnag@centeris.com> + Copyright (C) 2006 Gerald Carter <jerry@samba.org> + + ** NOTE! The following LGPL license applies to the libaddns + ** library. This does NOT imply that all of Samba is released + ** under the LGPL + + This library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + This library 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 + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with this library; if not, see <http://www.gnu.org/licenses/>. +*/ + +#include "dns.h" +#include "lib/util/genrand.h" + +DNS_ERROR dns_create_query( TALLOC_CTX *mem_ctx, const char *name, + uint16_t q_type, uint16_t q_class, + struct dns_request **preq ) +{ + struct dns_request *req = NULL; + struct dns_question *q = NULL; + DNS_ERROR err; + + if (!(req = talloc_zero(mem_ctx, struct dns_request)) || + !(req->questions = talloc_array(req, struct dns_question *, 1)) || + !(req->questions[0] = talloc(req->questions, + struct dns_question))) { + TALLOC_FREE(req); + return ERROR_DNS_NO_MEMORY; + } + + generate_random_buffer((uint8_t *)&req->id, sizeof(req->id)); + + req->num_questions = 1; + q = req->questions[0]; + + err = dns_domain_name_from_string(q, name, &q->name); + if (!ERR_DNS_IS_OK(err)) { + TALLOC_FREE(req); + return err; + } + + q->q_type = q_type; + q->q_class = q_class; + + *preq = req; + return ERROR_DNS_SUCCESS; +} + +DNS_ERROR dns_create_update( TALLOC_CTX *mem_ctx, const char *name, + struct dns_update_request **preq ) +{ + struct dns_update_request *req = NULL; + struct dns_zone *z = NULL; + DNS_ERROR err; + + if (!(req = talloc_zero(mem_ctx, struct dns_update_request)) || + !(req->zones = talloc_array(req, struct dns_zone *, 1)) || + !(req->zones[0] = talloc(req->zones, struct dns_zone))) { + TALLOC_FREE(req); + return ERROR_DNS_NO_MEMORY; + } + + req->id = random(); + req->flags = 0x2800; /* Dynamic update */ + + req->num_zones = 1; + z = req->zones[0]; + + err = dns_domain_name_from_string(z, name, &z->name); + if (!ERR_DNS_IS_OK(err)) { + TALLOC_FREE(req); + return err; + } + + z->z_type = QTYPE_SOA; + z->z_class = DNS_CLASS_IN; + + *preq = req; + return ERROR_DNS_SUCCESS; +} + +DNS_ERROR dns_create_rrec(TALLOC_CTX *mem_ctx, const char *name, + uint16_t type, uint16_t r_class, uint32_t ttl, + uint16_t data_length, uint8_t *data, + struct dns_rrec **prec) +{ + struct dns_rrec *rec = NULL; + DNS_ERROR err; + + if (!(rec = talloc(mem_ctx, struct dns_rrec))) { + return ERROR_DNS_NO_MEMORY; + } + + err = dns_domain_name_from_string(rec, name, &rec->name); + if (!(ERR_DNS_IS_OK(err))) { + TALLOC_FREE(rec); + return err; + } + + rec->type = type; + rec->r_class = r_class; + rec->ttl = ttl; + rec->data_length = data_length; + rec->data = talloc_move(rec, &data); + + *prec = rec; + return ERROR_DNS_SUCCESS; +} + +DNS_ERROR dns_create_a_record(TALLOC_CTX *mem_ctx, const char *host, + uint32_t ttl, const struct sockaddr_storage *pss, + struct dns_rrec **prec) +{ + uint8_t *data; + DNS_ERROR err; + struct in_addr ip; + + if (pss->ss_family != AF_INET) { + return ERROR_DNS_INVALID_PARAMETER; + } + + ip = ((const struct sockaddr_in *)pss)->sin_addr; + if (!(data = (uint8_t *)talloc_memdup(mem_ctx, (const void *)&ip.s_addr, + sizeof(ip.s_addr)))) { + return ERROR_DNS_NO_MEMORY; + } + + err = dns_create_rrec(mem_ctx, host, QTYPE_A, DNS_CLASS_IN, ttl, + sizeof(ip.s_addr), data, prec); + + if (!ERR_DNS_IS_OK(err)) { + TALLOC_FREE(data); + } + + return err; +} + +DNS_ERROR dns_create_aaaa_record(TALLOC_CTX *mem_ctx, const char *host, + uint32_t ttl, const struct sockaddr_storage *pss, + struct dns_rrec **prec) +{ +#ifdef HAVE_IPV6 + uint8_t *data; + DNS_ERROR err; + struct in6_addr ip6; + + if (pss->ss_family != AF_INET6) { + return ERROR_DNS_INVALID_PARAMETER; + } + + ip6 = ((const struct sockaddr_in6 *)pss)->sin6_addr; + if (!(data = (uint8_t *)talloc_memdup(mem_ctx, (const void *)&ip6.s6_addr, + sizeof(ip6.s6_addr)))) { + return ERROR_DNS_NO_MEMORY; + } + + err = dns_create_rrec(mem_ctx, host, QTYPE_AAAA, DNS_CLASS_IN, ttl, + sizeof(ip6.s6_addr), data, prec); + + if (!ERR_DNS_IS_OK(err)) { + TALLOC_FREE(data); + } + + return err; +#else + return ERROR_DNS_INVALID_PARAMETER; +#endif +} + +DNS_ERROR dns_create_name_in_use_record(TALLOC_CTX *mem_ctx, + const char *name, + const struct sockaddr_storage *ss, + struct dns_rrec **prec) +{ + if (ss != NULL) { + switch (ss->ss_family) { + case AF_INET: + return dns_create_a_record(mem_ctx, name, 0, ss, prec); +#ifdef HAVE_IPV6 + case AF_INET6: + return dns_create_aaaa_record(mem_ctx, name, 0, ss, prec); +#endif + default: + return ERROR_DNS_INVALID_PARAMETER; + } + } + + return dns_create_rrec(mem_ctx, name, QTYPE_ANY, DNS_CLASS_IN, 0, 0, + NULL, prec); +} + +DNS_ERROR dns_create_name_not_in_use_record(TALLOC_CTX *mem_ctx, + const char *name, uint32_t type, + struct dns_rrec **prec) +{ + return dns_create_rrec(mem_ctx, name, type, DNS_CLASS_NONE, 0, + 0, NULL, prec); +} + +DNS_ERROR dns_create_delete_record(TALLOC_CTX *mem_ctx, const char *name, + uint16_t type, uint16_t r_class, + struct dns_rrec **prec) +{ + return dns_create_rrec(mem_ctx, name, type, r_class, 0, 0, NULL, prec); +} + +DNS_ERROR dns_create_tkey_record(TALLOC_CTX *mem_ctx, const char *keyname, + const char *algorithm_name, time_t inception, + time_t expiration, uint16_t mode, uint16_t error, + uint16_t key_length, const uint8_t *key, + struct dns_rrec **prec) +{ + struct dns_buffer *buf = NULL; + struct dns_domain_name *algorithm = NULL; + DNS_ERROR err; + + if (!(buf = dns_create_buffer(mem_ctx))) { + return ERROR_DNS_NO_MEMORY; + } + + err = dns_domain_name_from_string(buf, algorithm_name, &algorithm); + if (!ERR_DNS_IS_OK(err)) goto error; + + dns_marshall_domain_name(buf, algorithm); + dns_marshall_uint32(buf, inception); + dns_marshall_uint32(buf, expiration); + dns_marshall_uint16(buf, mode); + dns_marshall_uint16(buf, error); + dns_marshall_uint16(buf, key_length); + dns_marshall_buffer(buf, key, key_length); + dns_marshall_uint16(buf, 0); /* Other Size */ + + if (!ERR_DNS_IS_OK(buf->error)) { + err = buf->error; + goto error; + } + + err = dns_create_rrec(mem_ctx, keyname, QTYPE_TKEY, DNS_CLASS_ANY, 0, + buf->offset, buf->data, prec); + + error: + TALLOC_FREE(buf); + return err; +} + +DNS_ERROR dns_unmarshall_tkey_record(TALLOC_CTX *mem_ctx, struct dns_rrec *rec, + struct dns_tkey_record **ptkey) +{ + struct dns_tkey_record *tkey; + struct dns_buffer buf; + uint32_t tmp_inception, tmp_expiration; + + if (!(tkey = talloc(mem_ctx, struct dns_tkey_record))) { + return ERROR_DNS_NO_MEMORY; + } + + buf.data = rec->data; + buf.size = rec->data_length; + buf.offset = 0; + buf.error = ERROR_DNS_SUCCESS; + + dns_unmarshall_domain_name(tkey, &buf, &tkey->algorithm); + dns_unmarshall_uint32(&buf, &tmp_inception); + dns_unmarshall_uint32(&buf, &tmp_expiration); + dns_unmarshall_uint16(&buf, &tkey->mode); + dns_unmarshall_uint16(&buf, &tkey->error); + dns_unmarshall_uint16(&buf, &tkey->key_length); + + if (!ERR_DNS_IS_OK(buf.error)) goto error; + + if (tkey->key_length) { + if (!(tkey->key = talloc_array(tkey, uint8_t, tkey->key_length))) { + buf.error = ERROR_DNS_NO_MEMORY; + goto error; + } + } else { + tkey->key = NULL; + } + + dns_unmarshall_buffer(&buf, tkey->key, tkey->key_length); + if (!ERR_DNS_IS_OK(buf.error)) goto error; + + tkey->inception = (time_t)tmp_inception; + tkey->expiration = (time_t)tmp_expiration; + + *ptkey = tkey; + return ERROR_DNS_SUCCESS; + + error: + TALLOC_FREE(tkey); + return buf.error; +} + +DNS_ERROR dns_create_tsig_record(TALLOC_CTX *mem_ctx, const char *keyname, + const char *algorithm_name, + time_t time_signed, uint16_t fudge, + uint16_t mac_length, const uint8_t *mac, + uint16_t original_id, uint16_t error, + struct dns_rrec **prec) +{ + struct dns_buffer *buf = NULL; + struct dns_domain_name *algorithm = NULL; + DNS_ERROR err; + + if (!(buf = dns_create_buffer(mem_ctx))) { + return ERROR_DNS_NO_MEMORY; + } + + err = dns_domain_name_from_string(buf, algorithm_name, &algorithm); + if (!ERR_DNS_IS_OK(err)) goto error; + + dns_marshall_domain_name(buf, algorithm); + dns_marshall_uint16(buf, 0); /* time prefix */ + dns_marshall_uint32(buf, time_signed); + dns_marshall_uint16(buf, fudge); + dns_marshall_uint16(buf, mac_length); + dns_marshall_buffer(buf, mac, mac_length); + dns_marshall_uint16(buf, original_id); + dns_marshall_uint16(buf, error); + dns_marshall_uint16(buf, 0); /* Other Size */ + + if (!ERR_DNS_IS_OK(buf->error)) { + err = buf->error; + goto error; + } + + err = dns_create_rrec(mem_ctx, keyname, QTYPE_TSIG, DNS_CLASS_ANY, 0, + buf->offset, buf->data, prec); + + error: + TALLOC_FREE(buf); + return err; +} + +DNS_ERROR dns_add_rrec(TALLOC_CTX *mem_ctx, struct dns_rrec *rec, + uint16_t *num_records, struct dns_rrec ***records) +{ + struct dns_rrec **new_records; + + if (!(new_records = talloc_realloc(mem_ctx, *records, + struct dns_rrec *, + (*num_records)+1))) { + return ERROR_DNS_NO_MEMORY; + } + + new_records[*num_records] = talloc_move(new_records, &rec); + + *num_records += 1; + *records = new_records; + return ERROR_DNS_SUCCESS; +} + +/* + * Create a request that probes a server whether the list of IP addresses + * provides meets our expectations + */ + +DNS_ERROR dns_create_probe(TALLOC_CTX *mem_ctx, const char *zone, + const char *host, int num_ips, + const struct sockaddr_storage *sslist, + struct dns_update_request **preq) +{ + struct dns_update_request *req = NULL; + struct dns_rrec *rec = NULL; + DNS_ERROR err; + uint16_t i; + + err = dns_create_update(mem_ctx, zone, &req); + if (!ERR_DNS_IS_OK(err)) return err; + + err = dns_create_name_not_in_use_record(req, host, QTYPE_CNAME, &rec); + if (!ERR_DNS_IS_OK(err)) goto error; + + err = dns_add_rrec(req, rec, &req->num_preqs, &req->preqs); + if (!ERR_DNS_IS_OK(err)) goto error; + + for (i=0; i<num_ips; i++) { + err = dns_create_name_in_use_record(req, host, + &sslist[i], &rec); + if (!ERR_DNS_IS_OK(err)) goto error; + + err = dns_add_rrec(req, rec, &req->num_preqs, &req->preqs); + if (!ERR_DNS_IS_OK(err)) goto error; + } + + *preq = req; + return ERROR_DNS_SUCCESS; + + error: + TALLOC_FREE(req); + return err; +} + +DNS_ERROR dns_create_update_request(TALLOC_CTX *mem_ctx, + const char *domainname, + const char *hostname, + const struct sockaddr_storage *ss_addrs, + size_t num_addrs, + struct dns_update_request **preq) +{ + struct dns_update_request *req = NULL; + struct dns_rrec *rec = NULL; + DNS_ERROR err; + size_t i; + + err = dns_create_update(mem_ctx, domainname, &req); + if (!ERR_DNS_IS_OK(err)) return err; + + /* + * Use the same prereq as WinXP -- No CNAME records for this host. + */ + + err = dns_create_rrec(req, hostname, QTYPE_CNAME, DNS_CLASS_NONE, + 0, 0, NULL, &rec); + if (!ERR_DNS_IS_OK(err)) goto error; + + err = dns_add_rrec(req, rec, &req->num_preqs, &req->preqs); + if (!ERR_DNS_IS_OK(err)) goto error; + + /* + * Delete all existing RRsets from our name + */ + + err = dns_create_delete_record(req, hostname, QTYPE_ANY, DNS_CLASS_ANY, + &rec); + if (!ERR_DNS_IS_OK(err)) goto error; + + err = dns_add_rrec(req, rec, &req->num_updates, &req->updates); + if (!ERR_DNS_IS_OK(err)) goto error; + + /* + * .. and add our IPs + */ + + for ( i=0; i<num_addrs; i++ ) { + + switch(ss_addrs[i].ss_family) { + case AF_INET: + err = dns_create_a_record(req, hostname, 3600, &ss_addrs[i], &rec); + break; +#ifdef HAVE_IPV6 + case AF_INET6: + err = dns_create_aaaa_record(req, hostname, 3600, &ss_addrs[i], &rec); + break; +#endif + default: + continue; + } + if (!ERR_DNS_IS_OK(err)) + goto error; + + err = dns_add_rrec(req, rec, &req->num_updates, &req->updates); + if (!ERR_DNS_IS_OK(err)) + goto error; + } + + *preq = req; + return ERROR_DNS_SUCCESS; + + error: + TALLOC_FREE(req); + return err; +} |