diff options
Diffstat (limited to 'source4/heimdal/lib/roken/resolve.c')
| -rw-r--r-- | source4/heimdal/lib/roken/resolve.c | 712 |
1 files changed, 712 insertions, 0 deletions
diff --git a/source4/heimdal/lib/roken/resolve.c b/source4/heimdal/lib/roken/resolve.c new file mode 100644 index 0000000000..4a121216da --- /dev/null +++ b/source4/heimdal/lib/roken/resolve.c @@ -0,0 +1,712 @@ +/* + * Copyright (c) 1995 - 2006 Kungliga Tekniska Högskolan + * (Royal Institute of Technology, Stockholm, Sweden). + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * 3. Neither the name of the Institute nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#ifdef HAVE_CONFIG_H +#include <config.h> +#endif +#include "roken.h" +#ifdef HAVE_ARPA_NAMESER_H +#include <arpa/nameser.h> +#endif +#ifdef HAVE_RESOLV_H +#include <resolv.h> +#endif +#include "resolve.h" + +#include <assert.h> + +RCSID("$Id$"); + +#ifdef _AIX /* AIX have broken res_nsearch() in 5.1 (5.0 also ?) */ +#undef HAVE_RES_NSEARCH +#endif + +#define DECL(X) {#X, rk_ns_t_##X} + +static struct stot{ + const char *name; + int type; +}stot[] = { + DECL(a), + DECL(aaaa), + DECL(ns), + DECL(cname), + DECL(soa), + DECL(ptr), + DECL(mx), + DECL(txt), + DECL(afsdb), + DECL(sig), + DECL(key), + DECL(srv), + DECL(naptr), + DECL(sshfp), + DECL(ds), + {NULL, 0} +}; + +int _resolve_debug = 0; + +int ROKEN_LIB_FUNCTION +dns_string_to_type(const char *name) +{ + struct stot *p = stot; + for(p = stot; p->name; p++) + if(strcasecmp(name, p->name) == 0) + return p->type; + return -1; +} + +const char * ROKEN_LIB_FUNCTION +dns_type_to_string(int type) +{ + struct stot *p = stot; + for(p = stot; p->name; p++) + if(type == p->type) + return p->name; + return NULL; +} + +#if (defined(HAVE_RES_SEARCH) || defined(HAVE_RES_NSEARCH)) && defined(HAVE_DN_EXPAND) + +static void +dns_free_rr(struct resource_record *rr) +{ + if(rr->domain) + free(rr->domain); + if(rr->u.data) + free(rr->u.data); + free(rr); +} + +void ROKEN_LIB_FUNCTION +dns_free_data(struct dns_reply *r) +{ + struct resource_record *rr; + if(r->q.domain) + free(r->q.domain); + for(rr = r->head; rr;){ + struct resource_record *tmp = rr; + rr = rr->next; + dns_free_rr(tmp); + } + free (r); +} + +static int +parse_record(const unsigned char *data, const unsigned char *end_data, + const unsigned char **pp, struct resource_record **ret_rr) +{ + struct resource_record *rr; + int type, class, ttl; + unsigned size; + int status; + char host[MAXDNAME]; + const unsigned char *p = *pp; + + *ret_rr = NULL; + + status = dn_expand(data, end_data, p, host, sizeof(host)); + if(status < 0) + return -1; + if (p + status + 10 > end_data) + return -1; + + p += status; + type = (p[0] << 8) | p[1]; + p += 2; + class = (p[0] << 8) | p[1]; + p += 2; + ttl = (p[0] << 24) | (p[1] << 16) | (p[2] << 8) | p[3]; + p += 4; + size = (p[0] << 8) | p[1]; + p += 2; + + if (p + size > end_data) + return -1; + + rr = calloc(1, sizeof(*rr)); + if(rr == NULL) + return -1; + rr->domain = strdup(host); + if(rr->domain == NULL) { + dns_free_rr(rr); + return -1; + } + rr->type = type; + rr->class = class; + rr->ttl = ttl; + rr->size = size; + switch(type){ + case rk_ns_t_ns: + case rk_ns_t_cname: + case rk_ns_t_ptr: + status = dn_expand(data, end_data, p, host, sizeof(host)); + if(status < 0) { + dns_free_rr(rr); + return -1; + } + rr->u.txt = strdup(host); + if(rr->u.txt == NULL) { + dns_free_rr(rr); + return -1; + } + break; + case rk_ns_t_mx: + case rk_ns_t_afsdb:{ + size_t hostlen; + + status = dn_expand(data, end_data, p + 2, host, sizeof(host)); + if(status < 0){ + dns_free_rr(rr); + return -1; + } + if (status + 2 > size) { + dns_free_rr(rr); + return -1; + } + + hostlen = strlen(host); + rr->u.mx = (struct mx_record*)malloc(sizeof(struct mx_record) + + hostlen); + if(rr->u.mx == NULL) { + dns_free_rr(rr); + return -1; + } + rr->u.mx->preference = (p[0] << 8) | p[1]; + strlcpy(rr->u.mx->domain, host, hostlen + 1); + break; + } + case rk_ns_t_srv:{ + size_t hostlen; + status = dn_expand(data, end_data, p + 6, host, sizeof(host)); + if(status < 0){ + dns_free_rr(rr); + return -1; + } + if (status + 6 > size) { + dns_free_rr(rr); + return -1; + } + + hostlen = strlen(host); + rr->u.srv = + (struct srv_record*)malloc(sizeof(struct srv_record) + + hostlen); + if(rr->u.srv == NULL) { + dns_free_rr(rr); + return -1; + } + rr->u.srv->priority = (p[0] << 8) | p[1]; + rr->u.srv->weight = (p[2] << 8) | p[3]; + rr->u.srv->port = (p[4] << 8) | p[5]; + strlcpy(rr->u.srv->target, host, hostlen + 1); + break; + } + case rk_ns_t_txt:{ + if(size == 0 || size < *p + 1) { + dns_free_rr(rr); + return -1; + } + rr->u.txt = (char*)malloc(*p + 1); + if(rr->u.txt == NULL) { + dns_free_rr(rr); + return -1; + } + strncpy(rr->u.txt, (const char*)(p + 1), *p); + rr->u.txt[*p] = '\0'; + break; + } + case rk_ns_t_key : { + size_t key_len; + + if (size < 4) { + dns_free_rr(rr); + return -1; + } + + key_len = size - 4; + rr->u.key = malloc (sizeof(*rr->u.key) + key_len - 1); + if (rr->u.key == NULL) { + dns_free_rr(rr); + return -1; + } + + rr->u.key->flags = (p[0] << 8) | p[1]; + rr->u.key->protocol = p[2]; + rr->u.key->algorithm = p[3]; + rr->u.key->key_len = key_len; + memcpy (rr->u.key->key_data, p + 4, key_len); + break; + } + case rk_ns_t_sig : { + size_t sig_len, hostlen; + + if(size <= 18) { + dns_free_rr(rr); + return -1; + } + status = dn_expand (data, end_data, p + 18, host, sizeof(host)); + if (status < 0) { + dns_free_rr(rr); + return -1; + } + if (status + 18 > size) { + dns_free_rr(rr); + return -1; + } + + /* the signer name is placed after the sig_data, to make it + easy to free this structure; the size calculation below + includes the zero-termination if the structure itself. + don't you just love C? + */ + sig_len = size - 18 - status; + hostlen = strlen(host); + rr->u.sig = malloc(sizeof(*rr->u.sig) + + hostlen + sig_len); + if (rr->u.sig == NULL) { + dns_free_rr(rr); + return -1; + } + rr->u.sig->type = (p[0] << 8) | p[1]; + rr->u.sig->algorithm = p[2]; + rr->u.sig->labels = p[3]; + rr->u.sig->orig_ttl = (p[4] << 24) | (p[5] << 16) + | (p[6] << 8) | p[7]; + rr->u.sig->sig_expiration = (p[8] << 24) | (p[9] << 16) + | (p[10] << 8) | p[11]; + rr->u.sig->sig_inception = (p[12] << 24) | (p[13] << 16) + | (p[14] << 8) | p[15]; + rr->u.sig->key_tag = (p[16] << 8) | p[17]; + rr->u.sig->sig_len = sig_len; + memcpy (rr->u.sig->sig_data, p + 18 + status, sig_len); + rr->u.sig->signer = &rr->u.sig->sig_data[sig_len]; + strlcpy(rr->u.sig->signer, host, hostlen + 1); + break; + } + + case rk_ns_t_cert : { + size_t cert_len; + + if (size < 5) { + dns_free_rr(rr); + return -1; + } + + cert_len = size - 5; + rr->u.cert = malloc (sizeof(*rr->u.cert) + cert_len - 1); + if (rr->u.cert == NULL) { + dns_free_rr(rr); + return -1; + } + + rr->u.cert->type = (p[0] << 8) | p[1]; + rr->u.cert->tag = (p[2] << 8) | p[3]; + rr->u.cert->algorithm = p[4]; + rr->u.cert->cert_len = cert_len; + memcpy (rr->u.cert->cert_data, p + 5, cert_len); + break; + } + case rk_ns_t_sshfp : { + size_t sshfp_len; + + if (size < 2) { + dns_free_rr(rr); + return -1; + } + + sshfp_len = size - 2; + + rr->u.sshfp = malloc (sizeof(*rr->u.sshfp) + sshfp_len - 1); + if (rr->u.sshfp == NULL) { + dns_free_rr(rr); + return -1; + } + + rr->u.sshfp->algorithm = p[0]; + rr->u.sshfp->type = p[1]; + rr->u.sshfp->sshfp_len = sshfp_len; + memcpy (rr->u.sshfp->sshfp_data, p + 2, sshfp_len); + break; + } + case rk_ns_t_ds: { + size_t digest_len; + + if (size < 4) { + dns_free_rr(rr); + return -1; + } + + digest_len = size - 4; + + rr->u.ds = malloc (sizeof(*rr->u.ds) + digest_len - 1); + if (rr->u.ds == NULL) { + dns_free_rr(rr); + return -1; + } + + rr->u.ds->key_tag = (p[0] << 8) | p[1]; + rr->u.ds->algorithm = p[2]; + rr->u.ds->digest_type = p[3]; + rr->u.ds->digest_len = digest_len; + memcpy (rr->u.ds->digest_data, p + 4, digest_len); + break; + } + default: + rr->u.data = (unsigned char*)malloc(size); + if(size != 0 && rr->u.data == NULL) { + dns_free_rr(rr); + return -1; + } + if (size) + memcpy(rr->u.data, p, size); + } + *pp = p + size; + *ret_rr = rr; + + return 0; +} + +#ifndef TEST_RESOLVE +static +#endif +struct dns_reply* +parse_reply(const unsigned char *data, size_t len) +{ + const unsigned char *p; + int status; + int i; + char host[MAXDNAME]; + const unsigned char *end_data = data + len; + struct dns_reply *r; + struct resource_record **rr; + + r = calloc(1, sizeof(*r)); + if (r == NULL) + return NULL; + + p = data; + + r->h.id = (p[0] << 8) | p[1]; + r->h.flags = 0; + if (p[2] & 0x01) + r->h.flags |= rk_DNS_HEADER_RESPONSE_FLAG; + r->h.opcode = (p[2] >> 1) & 0xf; + if (p[2] & 0x20) + r->h.flags |= rk_DNS_HEADER_AUTHORITIVE_ANSWER; + if (p[2] & 0x40) + r->h.flags |= rk_DNS_HEADER_TRUNCATED_MESSAGE; + if (p[2] & 0x80) + r->h.flags |= rk_DNS_HEADER_RECURSION_DESIRED; + if (p[3] & 0x01) + r->h.flags |= rk_DNS_HEADER_RECURSION_AVAILABLE; + if (p[3] & 0x04) + r->h.flags |= rk_DNS_HEADER_AUTHORITIVE_ANSWER; + if (p[3] & 0x08) + r->h.flags |= rk_DNS_HEADER_CHECKING_DISABLED; + r->h.response_code = (p[3] >> 4) & 0xf; + r->h.qdcount = (p[4] << 8) | p[5]; + r->h.ancount = (p[6] << 8) | p[7]; + r->h.nscount = (p[8] << 8) | p[9]; + r->h.arcount = (p[10] << 8) | p[11]; + + p += 12; + + if(r->h.qdcount != 1) { + free(r); + return NULL; + } + status = dn_expand(data, end_data, p, host, sizeof(host)); + if(status < 0){ + dns_free_data(r); + return NULL; + } + r->q.domain = strdup(host); + if(r->q.domain == NULL) { + dns_free_data(r); + return NULL; + } + if (p + status + 4 > end_data) { + dns_free_data(r); + return NULL; + } + p += status; + r->q.type = (p[0] << 8 | p[1]); + p += 2; + r->q.class = (p[0] << 8 | p[1]); + p += 2; + + rr = &r->head; + for(i = 0; i < r->h.ancount; i++) { + if(parse_record(data, end_data, &p, rr) != 0) { + dns_free_data(r); + return NULL; + } + rr = &(*rr)->next; + } + for(i = 0; i < r->h.nscount; i++) { + if(parse_record(data, end_data, &p, rr) != 0) { + dns_free_data(r); + return NULL; + } + rr = &(*rr)->next; + } + for(i = 0; i < r->h.arcount; i++) { + if(parse_record(data, end_data, &p, rr) != 0) { + dns_free_data(r); + return NULL; + } + rr = &(*rr)->next; + } + *rr = NULL; + return r; +} + +#ifdef HAVE_RES_NSEARCH +#ifdef HAVE_RES_NDESTROY +#define rk_res_free(x) res_ndestroy(x) +#else +#define rk_res_free(x) res_nclose(x) +#endif +#endif + +static struct dns_reply * +dns_lookup_int(const char *domain, int rr_class, int rr_type) +{ + struct dns_reply *r; + unsigned char *reply = NULL; + int size; + int len; +#ifdef HAVE_RES_NSEARCH + struct __res_state state; + memset(&state, 0, sizeof(state)); + if(res_ninit(&state)) + return NULL; /* is this the best we can do? */ +#elif defined(HAVE__RES) + u_long old_options = 0; +#endif + + size = 0; + len = 1000; + do { + if (reply) { + free(reply); + reply = NULL; + } + if (size <= len) + size = len; + if (_resolve_debug) { +#ifdef HAVE_RES_NSEARCH + state.options |= RES_DEBUG; +#elif defined(HAVE__RES) + old_options = _res.options; + _res.options |= RES_DEBUG; +#endif + fprintf(stderr, "dns_lookup(%s, %d, %s), buffer size %d\n", domain, + rr_class, dns_type_to_string(rr_type), size); + } + reply = malloc(size); + if (reply == NULL) { +#ifdef HAVE_RES_NSEARCH + rk_res_free(&state); +#endif + return NULL; + } +#ifdef HAVE_RES_NSEARCH + len = res_nsearch(&state, domain, rr_class, rr_type, reply, size); +#else + len = res_search(domain, rr_class, rr_type, reply, size); +#endif + if (_resolve_debug) { +#if defined(HAVE__RES) && !defined(HAVE_RES_NSEARCH) + _res.options = old_options; +#endif + fprintf(stderr, "dns_lookup(%s, %d, %s) --> %d\n", + domain, rr_class, dns_type_to_string(rr_type), len); + } + if (len < 0) { +#ifdef HAVE_RES_NSEARCH + rk_res_free(&state); +#endif + free(reply); + return NULL; + } + } while (size < len && len < rk_DNS_MAX_PACKET_SIZE); +#ifdef HAVE_RES_NSEARCH + rk_res_free(&state); +#endif + + len = min(len, size); + r = parse_reply(reply, len); + free(reply); + return r; +} + +struct dns_reply * ROKEN_LIB_FUNCTION +dns_lookup(const char *domain, const char *type_name) +{ + int type; + + type = dns_string_to_type(type_name); + if(type == -1) { + if(_resolve_debug) + fprintf(stderr, "dns_lookup: unknown resource type: `%s'\n", + type_name); + return NULL; + } + return dns_lookup_int(domain, C_IN, type); +} + +static int +compare_srv(const void *a, const void *b) +{ + const struct resource_record *const* aa = a, *const* bb = b; + + if((*aa)->u.srv->priority == (*bb)->u.srv->priority) + return ((*aa)->u.srv->weight - (*bb)->u.srv->weight); + return ((*aa)->u.srv->priority - (*bb)->u.srv->priority); +} + +#ifndef HAVE_RANDOM +#define random() rand() +#endif + +/* try to rearrange the srv-records by the algorithm in RFC2782 */ +void ROKEN_LIB_FUNCTION +dns_srv_order(struct dns_reply *r) +{ + struct resource_record **srvs, **ss, **headp; + struct resource_record *rr; + int num_srv = 0; + +#if defined(HAVE_INITSTATE) && defined(HAVE_SETSTATE) + int state[256 / sizeof(int)]; + char *oldstate; +#endif + + for(rr = r->head; rr; rr = rr->next) + if(rr->type == rk_ns_t_srv) + num_srv++; + + if(num_srv == 0) + return; + + srvs = malloc(num_srv * sizeof(*srvs)); + if(srvs == NULL) + return; /* XXX not much to do here */ + + /* unlink all srv-records from the linked list and put them in + a vector */ + for(ss = srvs, headp = &r->head; *headp; ) + if((*headp)->type == rk_ns_t_srv) { + *ss = *headp; + *headp = (*headp)->next; + (*ss)->next = NULL; + ss++; + } else + headp = &(*headp)->next; + + /* sort them by priority and weight */ + qsort(srvs, num_srv, sizeof(*srvs), compare_srv); + +#if defined(HAVE_INITSTATE) && defined(HAVE_SETSTATE) + oldstate = initstate(time(NULL), (char*)state, sizeof(state)); +#endif + + headp = &r->head; + + for(ss = srvs; ss < srvs + num_srv; ) { + int sum, rnd, count; + struct resource_record **ee, **tt; + /* find the last record with the same priority and count the + sum of all weights */ + for(sum = 0, tt = ss; tt < srvs + num_srv; tt++) { + assert(*tt != NULL); + if((*tt)->u.srv->priority != (*ss)->u.srv->priority) + break; + sum += (*tt)->u.srv->weight; + } + ee = tt; + /* ss is now the first record of this priority and ee is the + first of the next */ + while(ss < ee) { + rnd = random() % (sum + 1); + for(count = 0, tt = ss; ; tt++) { + if(*tt == NULL) + continue; + count += (*tt)->u.srv->weight; + if(count >= rnd) + break; + } + + assert(tt < ee); + + /* insert the selected record at the tail (of the head) of + the list */ + (*tt)->next = *headp; + *headp = *tt; + headp = &(*tt)->next; + sum -= (*tt)->u.srv->weight; + *tt = NULL; + while(ss < ee && *ss == NULL) + ss++; + } + } + +#if defined(HAVE_INITSTATE) && defined(HAVE_SETSTATE) + setstate(oldstate); +#endif + free(srvs); + return; +} + +#else /* NOT defined(HAVE_RES_SEARCH) && defined(HAVE_DN_EXPAND) */ + +struct dns_reply * ROKEN_LIB_FUNCTION +dns_lookup(const char *domain, const char *type_name) +{ + return NULL; +} + +void ROKEN_LIB_FUNCTION +dns_free_data(struct dns_reply *r) +{ +} + +void ROKEN_LIB_FUNCTION +dns_srv_order(struct dns_reply *r) +{ +} + +#endif |