diff options
Diffstat (limited to 'crypto/heimdal/lib/roken/resolve.c')
-rw-r--r-- | crypto/heimdal/lib/roken/resolve.c | 554 |
1 files changed, 554 insertions, 0 deletions
diff --git a/crypto/heimdal/lib/roken/resolve.c b/crypto/heimdal/lib/roken/resolve.c new file mode 100644 index 0000000..eddaa7d --- /dev/null +++ b/crypto/heimdal/lib/roken/resolve.c @@ -0,0 +1,554 @@ +/* + * Copyright (c) 1995 - 2001 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: resolve.c,v 1.30 2001/10/02 15:39:41 joda Exp $"); + +#if defined(HAVE_RES_SEARCH) && defined(HAVE_DN_EXPAND) + +#define DECL(X) {#X, T_##X} + +static struct stot{ + const char *name; + int type; +}stot[] = { + DECL(A), + DECL(NS), + DECL(CNAME), + DECL(SOA), + DECL(PTR), + DECL(MX), + DECL(TXT), + DECL(AFSDB), + DECL(SIG), + DECL(KEY), + DECL(SRV), + DECL(NAPTR), + {NULL, 0} +}; + +int _resolve_debug = 0; + +int +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 * +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; +} + +void +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; + if(rr->domain) + free(rr->domain); + if(rr->u.data) + free(rr->u.data); + rr = rr->next; + free(tmp); + } + free (r); +} + +static struct dns_reply* +parse_reply(unsigned char *data, int len) +{ + unsigned char *p; + char host[128]; + int status; + + struct dns_reply *r; + struct resource_record **rr; + + r = calloc(1, sizeof(*r)); + if (r == NULL) + return NULL; + + p = data; +#if 0 + /* doesn't work on Crays */ + memcpy(&r->h, p, sizeof(HEADER)); + p += sizeof(HEADER); +#else + memcpy(&r->h, p, 12); /* XXX this will probably be mostly garbage */ + p += 12; +#endif + status = dn_expand(data, data + len, 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; + } + 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; + while(p < data + len){ + int type, class, ttl, size; + status = dn_expand(data, data + len, p, host, sizeof(host)); + if(status < 0){ + dns_free_data(r); + return NULL; + } + 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; + *rr = (struct resource_record*)calloc(1, + sizeof(struct resource_record)); + if(*rr == NULL) { + dns_free_data(r); + return NULL; + } + (*rr)->domain = strdup(host); + if((*rr)->domain == NULL) { + dns_free_data(r); + return NULL; + } + (*rr)->type = type; + (*rr)->class = class; + (*rr)->ttl = ttl; + (*rr)->size = size; + switch(type){ + case T_NS: + case T_CNAME: + case T_PTR: + status = dn_expand(data, data + len, p, host, sizeof(host)); + if(status < 0){ + dns_free_data(r); + return NULL; + } + (*rr)->u.txt = strdup(host); + if((*rr)->u.txt == NULL) { + dns_free_data(r); + return NULL; + } + break; + case T_MX: + case T_AFSDB:{ + status = dn_expand(data, data + len, p + 2, host, sizeof(host)); + if(status < 0){ + dns_free_data(r); + return NULL; + } + (*rr)->u.mx = (struct mx_record*)malloc(sizeof(struct mx_record) + + strlen(host)); + if((*rr)->u.mx == NULL) { + dns_free_data(r); + return NULL; + } + (*rr)->u.mx->preference = (p[0] << 8) | p[1]; + strcpy((*rr)->u.mx->domain, host); + break; + } + case T_SRV:{ + status = dn_expand(data, data + len, p + 6, host, sizeof(host)); + if(status < 0){ + dns_free_data(r); + return NULL; + } + (*rr)->u.srv = + (struct srv_record*)malloc(sizeof(struct srv_record) + + strlen(host)); + if((*rr)->u.srv == NULL) { + dns_free_data(r); + return NULL; + } + (*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]; + strcpy((*rr)->u.srv->target, host); + break; + } + case T_TXT:{ + (*rr)->u.txt = (char*)malloc(size + 1); + if((*rr)->u.txt == NULL) { + dns_free_data(r); + return NULL; + } + strncpy((*rr)->u.txt, (char*)p + 1, *p); + (*rr)->u.txt[*p] = 0; + break; + } + case T_KEY : { + size_t key_len; + + key_len = size - 4; + (*rr)->u.key = malloc (sizeof(*(*rr)->u.key) + key_len - 1); + if ((*rr)->u.key == NULL) { + dns_free_data (r); + return NULL; + } + + (*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 T_SIG : { + size_t sig_len; + + status = dn_expand (data, data + len, p + 18, host, sizeof(host)); + if (status < 0) { + dns_free_data (r); + return NULL; + } + sig_len = len - 18 - status; + (*rr)->u.sig = malloc(sizeof(*(*rr)->u.sig) + + strlen(host) + sig_len); + if ((*rr)->u.sig == NULL) { + dns_free_data (r); + return NULL; + } + (*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]; + strcpy((*rr)->u.sig->signer, host); + break; + } + + case T_CERT : { + size_t cert_len; + + cert_len = size - 5; + (*rr)->u.cert = malloc (sizeof(*(*rr)->u.cert) + cert_len - 1); + if ((*rr)->u.cert == NULL) { + dns_free_data (r); + return NULL; + } + + (*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; + } + default: + (*rr)->u.data = (unsigned char*)malloc(size); + if(size != 0 && (*rr)->u.data == NULL) { + dns_free_data(r); + return NULL; + } + memcpy((*rr)->u.data, p, size); + } + p += size; + rr = &(*rr)->next; + } + *rr = NULL; + return r; +} + +static struct dns_reply * +dns_lookup_int(const char *domain, int rr_class, int rr_type) +{ + unsigned char reply[1024]; + int len; + struct dns_reply *r = NULL; + u_long old_options = 0; + + if (_resolve_debug) { + old_options = _res.options; + _res.options |= RES_DEBUG; + fprintf(stderr, "dns_lookup(%s, %d, %s)\n", domain, + rr_class, dns_type_to_string(rr_type)); + } + len = res_search(domain, rr_class, rr_type, reply, sizeof(reply)); + if (_resolve_debug) { + _res.options = old_options; + fprintf(stderr, "dns_lookup(%s, %d, %s) --> %d\n", + domain, rr_class, dns_type_to_string(rr_type), len); + } + if (len >= 0) + r = parse_reply(reply, len); + return r; +} + +struct dns_reply * +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 +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) + char state[256], *oldstate; +#endif + + for(rr = r->head; rr; rr = rr->next) + if(rr->type == 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 == 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), 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++) { + if(*tt == NULL) + continue; + 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 * +dns_lookup(const char *domain, const char *type_name) +{ + return NULL; +} + +void +dns_free_data(struct dns_reply *r) +{ +} + +void +dns_srv_order(struct dns_reply *r) +{ +} + +#endif + +#ifdef TEST +int +main(int argc, char **argv) +{ + struct dns_reply *r; + struct resource_record *rr; + r = dns_lookup(argv[1], argv[2]); + if(r == NULL){ + printf("No reply.\n"); + return 1; + } + if(r->q.type == T_SRV) + dns_srv_order(r); + + for(rr = r->head; rr;rr=rr->next){ + printf("%s %s %d ", rr->domain, dns_type_to_string(rr->type), rr->ttl); + switch(rr->type){ + case T_NS: + case T_CNAME: + case T_PTR: + printf("%s\n", (char*)rr->u.data); + break; + case T_A: + printf("%s\n", inet_ntoa(*rr->u.a)); + break; + case T_MX: + case T_AFSDB:{ + printf("%d %s\n", rr->u.mx->preference, rr->u.mx->domain); + break; + } + case T_SRV:{ + struct srv_record *srv = rr->u.srv; + printf("%d %d %d %s\n", srv->priority, srv->weight, + srv->port, srv->target); + break; + } + case T_TXT: { + printf("%s\n", rr->u.txt); + break; + } + case T_SIG : { + struct sig_record *sig = rr->u.sig; + const char *type_string = dns_type_to_string (sig->type); + + printf ("type %u (%s), algorithm %u, labels %u, orig_ttl %u, sig_expiration %u, sig_inception %u, key_tag %u, signer %s\n", + sig->type, type_string ? type_string : "", + sig->algorithm, sig->labels, sig->orig_ttl, + sig->sig_expiration, sig->sig_inception, sig->key_tag, + sig->signer); + break; + } + case T_KEY : { + struct key_record *key = rr->u.key; + + printf ("flags %u, protocol %u, algorithm %u\n", + key->flags, key->protocol, key->algorithm); + break; + } + default: + printf("\n"); + break; + } + } + + return 0; +} +#endif |