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-rw-r--r--lib/bind/irs/hesiod.c505
1 files changed, 505 insertions, 0 deletions
diff --git a/lib/bind/irs/hesiod.c b/lib/bind/irs/hesiod.c
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--- /dev/null
+++ b/lib/bind/irs/hesiod.c
@@ -0,0 +1,505 @@
+#if defined(LIBC_SCCS) && !defined(lint)
+static const char rcsid[] = "$Id: hesiod.c,v 1.4.18.3 2005/07/28 07:38:08 marka Exp $";
+#endif
+
+/*
+ * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
+ * Copyright (c) 1996,1999 by Internet Software Consortium.
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
+ * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+
+/*! \file
+ * \brief
+ * hesiod.c --- the core portion of the hesiod resolver.
+ *
+ * This file is derived from the hesiod library from Project Athena;
+ * It has been extensively rewritten by Theodore Ts'o to have a more
+ * thread-safe interface.
+ * \author
+ * This file is primarily maintained by <tytso@mit.edu> and <ghudson@mit.edu>.
+ */
+
+/* Imports */
+
+#include "port_before.h"
+
+#include <sys/types.h>
+#include <netinet/in.h>
+#include <arpa/nameser.h>
+
+#include <errno.h>
+#include <netdb.h>
+#include <resolv.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "port_after.h"
+
+#include "pathnames.h"
+#include "hesiod.h"
+#include "hesiod_p.h"
+
+/* Forward */
+
+int hesiod_init(void **context);
+void hesiod_end(void *context);
+char * hesiod_to_bind(void *context, const char *name,
+ const char *type);
+char ** hesiod_resolve(void *context, const char *name,
+ const char *type);
+void hesiod_free_list(void *context, char **list);
+
+static int parse_config_file(struct hesiod_p *ctx, const char *filename);
+static char ** get_txt_records(struct hesiod_p *ctx, int class,
+ const char *name);
+static int init(struct hesiod_p *ctx);
+
+/* Public */
+
+/*%
+ * This function is called to initialize a hesiod_p.
+ */
+int
+hesiod_init(void **context) {
+ struct hesiod_p *ctx;
+ char *cp;
+
+ ctx = malloc(sizeof(struct hesiod_p));
+ if (ctx == 0) {
+ errno = ENOMEM;
+ return (-1);
+ }
+
+ memset(ctx, 0, sizeof (*ctx));
+
+ if (parse_config_file(ctx, _PATH_HESIOD_CONF) < 0) {
+#ifdef DEF_RHS
+ /*
+ * Use compiled in defaults.
+ */
+ ctx->LHS = malloc(strlen(DEF_LHS) + 1);
+ ctx->RHS = malloc(strlen(DEF_RHS) + 1);
+ if (ctx->LHS == NULL || ctx->RHS == NULL) {
+ errno = ENOMEM;
+ goto cleanup;
+ }
+ strcpy(ctx->LHS, DEF_LHS); /* (checked) */
+ strcpy(ctx->RHS, DEF_RHS); /* (checked) */
+#else
+ goto cleanup;
+#endif
+ }
+ /*
+ * The default RHS can be overridden by an environment
+ * variable.
+ */
+ if ((cp = getenv("HES_DOMAIN")) != NULL) {
+ size_t RHSlen = strlen(cp) + 2;
+ if (ctx->RHS)
+ free(ctx->RHS);
+ ctx->RHS = malloc(RHSlen);
+ if (!ctx->RHS) {
+ errno = ENOMEM;
+ goto cleanup;
+ }
+ if (cp[0] == '.') {
+ strcpy(ctx->RHS, cp); /* (checked) */
+ } else {
+ strcpy(ctx->RHS, "."); /* (checked) */
+ strcat(ctx->RHS, cp); /* (checked) */
+ }
+ }
+
+ /*
+ * If there is no default hesiod realm set, we return an
+ * error.
+ */
+ if (!ctx->RHS) {
+ errno = ENOEXEC;
+ goto cleanup;
+ }
+
+#if 0
+ if (res_ninit(ctx->res) < 0)
+ goto cleanup;
+#endif
+
+ *context = ctx;
+ return (0);
+
+ cleanup:
+ hesiod_end(ctx);
+ return (-1);
+}
+
+/*%
+ * This function deallocates the hesiod_p
+ */
+void
+hesiod_end(void *context) {
+ struct hesiod_p *ctx = (struct hesiod_p *) context;
+ int save_errno = errno;
+
+ if (ctx->res)
+ res_nclose(ctx->res);
+ if (ctx->RHS)
+ free(ctx->RHS);
+ if (ctx->LHS)
+ free(ctx->LHS);
+ if (ctx->res && ctx->free_res)
+ (*ctx->free_res)(ctx->res);
+ free(ctx);
+ errno = save_errno;
+}
+
+/*%
+ * This function takes a hesiod (name, type) and returns a DNS
+ * name which is to be resolved.
+ */
+char *
+hesiod_to_bind(void *context, const char *name, const char *type) {
+ struct hesiod_p *ctx = (struct hesiod_p *) context;
+ char *bindname;
+ char **rhs_list = NULL;
+ const char *RHS, *cp;
+
+ /* Decide what our RHS is, and set cp to the end of the actual name. */
+ if ((cp = strchr(name, '@')) != NULL) {
+ if (strchr(cp + 1, '.'))
+ RHS = cp + 1;
+ else if ((rhs_list = hesiod_resolve(context, cp + 1,
+ "rhs-extension")) != NULL)
+ RHS = *rhs_list;
+ else {
+ errno = ENOENT;
+ return (NULL);
+ }
+ } else {
+ RHS = ctx->RHS;
+ cp = name + strlen(name);
+ }
+
+ /*
+ * Allocate the space we need, including up to three periods and
+ * the terminating NUL.
+ */
+ if ((bindname = malloc((cp - name) + strlen(type) + strlen(RHS) +
+ (ctx->LHS ? strlen(ctx->LHS) : 0) + 4)) == NULL) {
+ errno = ENOMEM;
+ if (rhs_list)
+ hesiod_free_list(context, rhs_list);
+ return NULL;
+ }
+
+ /* Now put together the DNS name. */
+ memcpy(bindname, name, cp - name);
+ bindname[cp - name] = '\0';
+ strcat(bindname, ".");
+ strcat(bindname, type);
+ if (ctx->LHS) {
+ if (ctx->LHS[0] != '.')
+ strcat(bindname, ".");
+ strcat(bindname, ctx->LHS);
+ }
+ if (RHS[0] != '.')
+ strcat(bindname, ".");
+ strcat(bindname, RHS);
+
+ if (rhs_list)
+ hesiod_free_list(context, rhs_list);
+
+ return (bindname);
+}
+
+/*%
+ * This is the core function. Given a hesiod (name, type), it
+ * returns an array of strings returned by the resolver.
+ */
+char **
+hesiod_resolve(void *context, const char *name, const char *type) {
+ struct hesiod_p *ctx = (struct hesiod_p *) context;
+ char *bindname = hesiod_to_bind(context, name, type);
+ char **retvec;
+
+ if (bindname == NULL)
+ return (NULL);
+ if (init(ctx) == -1) {
+ free(bindname);
+ return (NULL);
+ }
+
+ if ((retvec = get_txt_records(ctx, C_IN, bindname))) {
+ free(bindname);
+ return (retvec);
+ }
+
+ if (errno != ENOENT)
+ return (NULL);
+
+ retvec = get_txt_records(ctx, C_HS, bindname);
+ free(bindname);
+ return (retvec);
+}
+
+void
+hesiod_free_list(void *context, char **list) {
+ char **p;
+
+ UNUSED(context);
+
+ for (p = list; *p; p++)
+ free(*p);
+ free(list);
+}
+
+/*%
+ * This function parses the /etc/hesiod.conf file
+ */
+static int
+parse_config_file(struct hesiod_p *ctx, const char *filename) {
+ char *key, *data, *cp, **cpp;
+ char buf[MAXDNAME+7];
+ FILE *fp;
+
+ /*
+ * Clear the existing configuration variable, just in case
+ * they're set.
+ */
+ if (ctx->RHS)
+ free(ctx->RHS);
+ if (ctx->LHS)
+ free(ctx->LHS);
+ ctx->RHS = ctx->LHS = 0;
+
+ /*
+ * Now open and parse the file...
+ */
+ if (!(fp = fopen(filename, "r")))
+ return (-1);
+
+ while (fgets(buf, sizeof(buf), fp) != NULL) {
+ cp = buf;
+ if (*cp == '#' || *cp == '\n' || *cp == '\r')
+ continue;
+ while(*cp == ' ' || *cp == '\t')
+ cp++;
+ key = cp;
+ while(*cp != ' ' && *cp != '\t' && *cp != '=')
+ cp++;
+ *cp++ = '\0';
+
+ while(*cp == ' ' || *cp == '\t' || *cp == '=')
+ cp++;
+ data = cp;
+ while(*cp != ' ' && *cp != '\n' && *cp != '\r')
+ cp++;
+ *cp++ = '\0';
+
+ if (strcmp(key, "lhs") == 0)
+ cpp = &ctx->LHS;
+ else if (strcmp(key, "rhs") == 0)
+ cpp = &ctx->RHS;
+ else
+ continue;
+
+ *cpp = malloc(strlen(data) + 1);
+ if (!*cpp) {
+ errno = ENOMEM;
+ goto cleanup;
+ }
+ strcpy(*cpp, data);
+ }
+ fclose(fp);
+ return (0);
+
+ cleanup:
+ fclose(fp);
+ if (ctx->RHS)
+ free(ctx->RHS);
+ if (ctx->LHS)
+ free(ctx->LHS);
+ ctx->RHS = ctx->LHS = 0;
+ return (-1);
+}
+
+/*%
+ * Given a DNS class and a DNS name, do a lookup for TXT records, and
+ * return a list of them.
+ */
+static char **
+get_txt_records(struct hesiod_p *ctx, int class, const char *name) {
+ struct {
+ int type; /*%< RR type */
+ int class; /*%< RR class */
+ int dlen; /*%< len of data section */
+ u_char *data; /*%< pointer to data */
+ } rr;
+ HEADER *hp;
+ u_char qbuf[MAX_HESRESP], abuf[MAX_HESRESP];
+ u_char *cp, *erdata, *eom;
+ char *dst, *edst, **list;
+ int ancount, qdcount;
+ int i, j, n, skip;
+
+ /*
+ * Construct the query and send it.
+ */
+ n = res_nmkquery(ctx->res, QUERY, name, class, T_TXT, NULL, 0,
+ NULL, qbuf, MAX_HESRESP);
+ if (n < 0) {
+ errno = EMSGSIZE;
+ return (NULL);
+ }
+ n = res_nsend(ctx->res, qbuf, n, abuf, MAX_HESRESP);
+ if (n < 0) {
+ errno = ECONNREFUSED;
+ return (NULL);
+ }
+ if (n < HFIXEDSZ) {
+ errno = EMSGSIZE;
+ return (NULL);
+ }
+
+ /*
+ * OK, parse the result.
+ */
+ hp = (HEADER *) abuf;
+ ancount = ntohs(hp->ancount);
+ qdcount = ntohs(hp->qdcount);
+ cp = abuf + sizeof(HEADER);
+ eom = abuf + n;
+
+ /* Skip query, trying to get to the answer section which follows. */
+ for (i = 0; i < qdcount; i++) {
+ skip = dn_skipname(cp, eom);
+ if (skip < 0 || cp + skip + QFIXEDSZ > eom) {
+ errno = EMSGSIZE;
+ return (NULL);
+ }
+ cp += skip + QFIXEDSZ;
+ }
+
+ list = malloc((ancount + 1) * sizeof(char *));
+ if (!list) {
+ errno = ENOMEM;
+ return (NULL);
+ }
+ j = 0;
+ for (i = 0; i < ancount; i++) {
+ skip = dn_skipname(cp, eom);
+ if (skip < 0) {
+ errno = EMSGSIZE;
+ goto cleanup;
+ }
+ cp += skip;
+ if (cp + 3 * INT16SZ + INT32SZ > eom) {
+ errno = EMSGSIZE;
+ goto cleanup;
+ }
+ rr.type = ns_get16(cp);
+ cp += INT16SZ;
+ rr.class = ns_get16(cp);
+ cp += INT16SZ + INT32SZ; /*%< skip the ttl, too */
+ rr.dlen = ns_get16(cp);
+ cp += INT16SZ;
+ if (cp + rr.dlen > eom) {
+ errno = EMSGSIZE;
+ goto cleanup;
+ }
+ rr.data = cp;
+ cp += rr.dlen;
+ if (rr.class != class || rr.type != T_TXT)
+ continue;
+ if (!(list[j] = malloc(rr.dlen)))
+ goto cleanup;
+ dst = list[j++];
+ edst = dst + rr.dlen;
+ erdata = rr.data + rr.dlen;
+ cp = rr.data;
+ while (cp < erdata) {
+ n = (unsigned char) *cp++;
+ if (cp + n > eom || dst + n > edst) {
+ errno = EMSGSIZE;
+ goto cleanup;
+ }
+ memcpy(dst, cp, n);
+ cp += n;
+ dst += n;
+ }
+ if (cp != erdata) {
+ errno = EMSGSIZE;
+ goto cleanup;
+ }
+ *dst = '\0';
+ }
+ list[j] = NULL;
+ if (j == 0) {
+ errno = ENOENT;
+ goto cleanup;
+ }
+ return (list);
+
+ cleanup:
+ for (i = 0; i < j; i++)
+ free(list[i]);
+ free(list);
+ return (NULL);
+}
+
+struct __res_state *
+__hesiod_res_get(void *context) {
+ struct hesiod_p *ctx = context;
+
+ if (!ctx->res) {
+ struct __res_state *res;
+ res = (struct __res_state *)malloc(sizeof *res);
+ if (res == NULL) {
+ errno = ENOMEM;
+ return (NULL);
+ }
+ memset(res, 0, sizeof *res);
+ __hesiod_res_set(ctx, res, free);
+ }
+
+ return (ctx->res);
+}
+
+void
+__hesiod_res_set(void *context, struct __res_state *res,
+ void (*free_res)(void *)) {
+ struct hesiod_p *ctx = context;
+
+ if (ctx->res && ctx->free_res) {
+ res_nclose(ctx->res);
+ (*ctx->free_res)(ctx->res);
+ }
+
+ ctx->res = res;
+ ctx->free_res = free_res;
+}
+
+static int
+init(struct hesiod_p *ctx) {
+
+ if (!ctx->res && !__hesiod_res_get(ctx))
+ return (-1);
+
+ if (((ctx->res->options & RES_INIT) == 0U) &&
+ (res_ninit(ctx->res) == -1))
+ return (-1);
+
+ return (0);
+}
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