initial commit

.gitignore

@@ -0,0 +1,3 @@
+.*swp
+*.so.*
+*.o

Makefile

@@ -0,0 +1,17 @@
+CC = gcc
+CFLAGS = --std=gnu99 -fPIC -O2 -g -ggdb -Wall
+LDFLAGS = -lunbound
+
+BINS = libnss_ubdns.so.2
+
+all: $(BINS)
+
+UBDNS_OBJS = arpa.o domain_to_str.o lookup.o ubdns.o
+
+libnss_ubdns.so.2: $(UBDNS_OBJS)
+	$(CC) -fPIC -shared -Wl,-h,libnss_ubdns.so.2 -Wl,--version-script,nss_ubdns.map -o $@ $(LDFLAGS) $^
+
+clean:
+	rm -f $(BINS) $(UBDNS_OBJS)
+
+.PHONY: all clean

arpa.c

@@ -0,0 +1,89 @@
+/* arpa.c - convert IPv4 or IPv6 address to PTR qname
+ * based on isip4() and isip6() from unbound-host
+ */
+
+/*
+ * Copyright (C) 2011 Robert S. Edmonds
+ *
+ * Permission to use, copy, modify, and/or 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.
+ */
+
+/*
+ * checkconf/unbound-host.c - replacement for host that supports validation.
+ *
+ * Copyright (c) 2007, NLnet Labs. All rights reserved.
+ *
+ * This software is open source.
+ * 
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 
+ * Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ * 
+ * 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.
+ * 
+ * Neither the name of the NLNET LABS 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 COPYRIGHT HOLDERS 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 REGENTS 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.
+ */
+
+#include <stdint.h>
+#include <stdio.h>
+#include <string.h>
+
+void
+arpa_qname_ip4(const void *addr, char **res) {
+	char buf[32];
+	snprintf(buf, sizeof(buf), "%u.%u.%u.%u.in-addr.arpa.",
+		 (unsigned)((uint8_t *) addr)[3],
+		 (unsigned)((uint8_t *) addr)[2],
+		 (unsigned)((uint8_t *) addr)[1],
+		 (unsigned)((uint8_t *) addr)[0]
+	);
+	*res = strdup(buf);
+}
+
+void
+arpa_qname_ip6(const void *addr, char **res) {
+	const char *hex = "0123456789abcdef";
+	char buf[128];
+	char *p;
+	int i;
+
+	p = buf;
+	for (i = 15; i >= 0; i--) {
+		uint8_t b = ((uint8_t *) addr)[i];
+		*p++ = hex[ (b & 0x0f) ];
+		*p++ = '.';
+		*p++ = hex[ (b & 0xf0) >> 4 ];
+		*p++ = '.';
+	}
+	snprintf(buf + 16*4, sizeof(buf) - 16*4, "ip6.arpa.");
+	*res = strdup(buf);
+}

domain_to_str.c

@@ -0,0 +1,73 @@
+/* domain_to_str.c - convert wire-format DNS name to presentation format
+ * from wreck/wdns/msg/domain_to_str.c
+ */
+
+/*
+ * Copyright (c) 2009, 2010 by Internet Systems Consortium, Inc. ("ISC")
+ * 
+ * Permission to use, copy, modify, and/or 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.
+ */
+
+#include <assert.h>
+#include <stdint.h>
+#include <stdio.h>
+
+/**
+ * Convert a domain name to a human-readable string.
+ *
+ * \param[in] src domain name in wire format
+ * \param[in] src_len length of domain name in bytes
+ * \param[out] dst caller-allocated string buffer of size WDNS_PRESLEN_NAME
+ * 
+ * \return Number of bytes read from src.
+ */
+
+size_t
+domain_to_str(const uint8_t *src, size_t src_len, char *dst) {
+	size_t bytes_read = 0;
+	size_t bytes_remaining = src_len;
+	uint8_t oclen;
+
+	assert(src != NULL);
+
+	oclen = *src;
+	while (bytes_remaining > 0 && oclen != 0) {
+		src++;
+		bytes_remaining--;
+
+		bytes_read += oclen + 1 /* length octet */;
+
+		while (oclen-- && bytes_remaining > 0) {
+			uint8_t c = *src++;
+			bytes_remaining--;
+
+			if (c == '.') {
+				*dst++ = '\\';
+				*dst++ = c;
+			} else if (c >= '!' && c <= '~') {
+				*dst++ = c;
+			} else {
+				snprintf(dst, 5, "\\%.3d", c);
+				dst += 4;
+			}
+		}
+		*dst++ = '.';
+		oclen = *src;
+	}
+	if (bytes_read == 0)
+		*dst++ = '.';
+	bytes_read++;
+
+	*dst = '\0';
+	return (bytes_read);
+}

lookup.c

@@ -0,0 +1,181 @@
+/*
+ * Copyright (C) 2011 Robert S. Edmonds
+ *
+ * Permission to use, copy, modify, and/or 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.
+ */
+
+#include <assert.h>
+#include <ctype.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <unbound.h>
+
+#include "ubdns.h"
+
+static struct ub_ctx *ctx = NULL;
+
+static void __attribute__((constructor))
+ubdns_init(void) {
+	int ret = 0;
+
+	ctx = ub_ctx_create();
+	if (ctx != NULL) {
+		int ret;
+
+		ret = ub_ctx_resolvconf(ctx, "/etc/ubdns/resolv.conf");
+		if (ret != 0)
+			goto out;
+
+		ret = ub_ctx_add_ta_file(ctx, "/var/lib/unbound/root.key");
+		if (ret != 0)
+			goto out;
+	}
+
+out:
+	if (ret != 0) {
+		if (ctx != NULL)
+			ub_ctx_delete(ctx);
+		ctx = NULL;
+	}
+}
+
+static void __attribute__((destructor))
+ubdns_finish(void) {
+	ub_ctx_delete(ctx);
+	ctx = NULL;
+}
+
+static bool
+ubdns_check_result(struct ub_result *res) {
+	if (res->havedata == 0)
+		return (false);
+	if (res->bogus)
+		return (false);
+
+	return (true);
+}
+
+static int
+ubdns_add_result(struct address **_list, unsigned *_n_list, struct ub_result *res, int af) {
+	struct address *list = *_list;
+	unsigned n_list = *_n_list;
+	int i;
+
+	if (!ubdns_check_result(res))
+		return (0);
+
+	for (i = 0; res->data[i] != NULL; i++) {
+		if (res->len[i] == PROTO_ADDRESS_SIZE(af)) {
+			list = realloc(list, (n_list + 1) * sizeof(struct address));
+			if (!list)
+				return (-1);
+
+			list[n_list].family = af;
+			list[n_list].scope = 0;
+			memcpy(list[n_list].address, res->data[i], PROTO_ADDRESS_SIZE(af));
+			n_list += 1;
+		}
+	}
+
+	*_list = list;
+	*_n_list = n_list;
+	return (0);
+}
+
+int
+ubdns_lookup_forward(const char *hn, int af, struct address **_list, unsigned *_n_list) {
+	struct address *list = NULL;
+	unsigned n_list = 0;
+	int r = 1;
+	int ret;
+
+	struct ub_result *res;
+
+	if (ctx == NULL)
+		goto err;
+
+	if (af == AF_INET || af == AF_UNSPEC) {
+		ret = ub_resolve(ctx, (char *) hn, 1 /*A*/, 1 /*IN*/, &res);
+		if (ret != 0)
+			goto err;
+
+		ret = ubdns_add_result(&list, &n_list, res, AF_INET);
+		if (ret != 0)
+			goto err;
+
+		ub_resolve_free(res);
+	}
+
+	if (af == AF_INET6 || af == AF_UNSPEC) {
+		ret = ub_resolve(ctx, (char *) hn, 28 /*A*/, 1 /*IN*/, &res);
+		if (ret != 0)
+			goto err;
+
+		ret = ubdns_add_result(&list, &n_list, res, AF_INET6);
+		if (ret != 0)
+			goto err;
+
+		ub_resolve_free(res);
+	}
+
+finish:
+	if (r < 0) {
+		free(list);
+	} else {
+		qsort(list, n_list, sizeof(struct address), address_compare);
+
+		*_list = list;
+		*_n_list = n_list;
+	}
+
+	return r;
+err:
+	r = 0;
+	goto finish;
+}
+
+char *
+ubdns_lookup_reverse(const void *addr, int af) {
+	struct ub_result *res;
+	char *qname = NULL;
+	int ret;
+
+	if (ctx == NULL)
+		return (NULL);
+
+	if (af == AF_INET) {
+		arpa_qname_ip4(addr, &qname);
+	} else if (af == AF_INET6) {
+		arpa_qname_ip6(addr, &qname);
+	} else {
+		return (NULL);
+	}
+
+	ret = ub_resolve(ctx, qname, 12 /*PTR*/, 1 /*IN*/, &res);
+
+	if (ret == 0 &&
+	    ubdns_check_result(res) &&
+	    res->data[0] != NULL)
+	{
+		char name[1025];
+		domain_to_str((const uint8_t *) res->data[0], res->len[0], name);
+		return (strdup(name));
+	}
+
+	return (NULL);
+}

nss_ubdns.map

@@ -0,0 +1,11 @@
+EXPORTED {
+    global:
+        _nss_ubdns_gethostbyaddr2_r;
+        _nss_ubdns_gethostbyaddr_r;
+        _nss_ubdns_gethostbyname2_r;
+        _nss_ubdns_gethostbyname3_r;
+        _nss_ubdns_gethostbyname4_r;
+        _nss_ubdns_gethostbyname_r;
+    local:
+        *;
+};