Move ucl and rdns to contrib.

1 files changed, 419 insertions, 0 deletions

diff --git a/contrib/librdns/parse.c b/contrib/librdns/parse.c
new file mode 100644
index 000000000..e9527eaa4
--- /dev/null
+++ b/contrib/librdns/parse.c
@@ -0,0 +1,419 @@
+/* Copyright (c) 2014, Vsevolod Stakhov
+ * All rights reserved.
+ *
+ * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED ''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 AUTHOR 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 "rdns.h"
+#include "dns_private.h"
+#include "parse.h"
+#include "logger.h"
+
+static uint8_t *
+rdns_decompress_label (uint8_t *begin, uint16_t *len, uint16_t max)
+{
+	uint16_t offset = (*len);
+
+	if (offset > max) {
+		return NULL;
+	}
+	*len = *(begin + offset);
+	return begin + offset;
+}
+
+#define UNCOMPRESS_DNS_OFFSET(p) (((*(p)) ^ DNS_COMPRESSION_BITS) << 8) + *((p) + 1)
+
+uint8_t *
+rdns_request_reply_cmp (struct rdns_request *req, uint8_t *in, int len)
+{
+	uint8_t *p, *c, *l1, *l2;
+	uint16_t len1, len2;
+	int decompressed = 0;
+	struct rdns_resolver *resolver = req->resolver;
+
+	/* QR format:
+	 * labels - len:octets
+	 * null label - 0
+	 * class - 2 octets
+	 * type - 2 octets
+	 */
+
+	/* In p we would store current position in reply and in c - position in request */
+	p = in;
+	c = req->packet + req->pos;
+
+	for (;;) {
+		/* Get current label */
+		len1 = *p;
+		len2 = *c;
+		if (p - in > len) {
+			rdns_info ("invalid dns reply");
+			return NULL;
+		}
+		/* This may be compressed, so we need to decompress it */
+		if (len1 & DNS_COMPRESSION_BITS) {
+			len1 = UNCOMPRESS_DNS_OFFSET(p);
+			l1 = rdns_decompress_label (in, &len1, len);
+			if (l1 == NULL) {
+				return NULL;
+			}
+			decompressed ++;
+			l1 ++;
+			p += 2;
+		}
+		else {
+			l1 = ++p;
+			p += len1;
+		}
+		if (len2 & DNS_COMPRESSION_BITS) {
+			len2 = UNCOMPRESS_DNS_OFFSET(c);
+			l2 = rdns_decompress_label (c, &len2, len);
+			if (l2 == NULL) {
+				rdns_info ("invalid DNS pointer, cannot decompress");
+				return NULL;
+			}
+			decompressed ++;
+			l2 ++;
+			c += 2;
+		}
+		else {
+			l2 = ++c;
+			c += len2;
+		}
+		if (len1 != len2) {
+			return NULL;
+		}
+		if (len1 == 0) {
+			break;
+		}
+
+		if (memcmp (l1, l2, len1) != 0) {
+			return NULL;
+		}
+		if (decompressed == 2) {
+			break;
+		}
+	}
+
+	/* p now points to the end of QR section */
+	/* Compare class and type */
+	if (memcmp (p, c, sizeof (uint16_t) * 2) == 0) {
+		req->pos = c - req->packet + sizeof (uint16_t) * 2;
+		return p + sizeof (uint16_t) * 2;
+	}
+	return NULL;
+}
+
+#define MAX_RECURSION_LEVEL 10
+
+bool
+rdns_parse_labels (struct rdns_resolver *resolver,
+		uint8_t *in, char **target, uint8_t **pos, struct rdns_reply *rep,
+		int *remain, bool make_name)
+{
+	uint16_t namelen = 0;
+	uint8_t *p = *pos, *begin = *pos, *l, *t, *end = *pos + *remain, *new_pos = *pos;
+	uint16_t llen;
+	int length = *remain, new_remain = *remain;
+	int ptrs = 0, labels = 0;
+	bool got_compression = false;
+
+	/* First go through labels and calculate name length */
+	while (p - begin < length) {
+		if (ptrs > MAX_RECURSION_LEVEL) {
+			rdns_info ("dns pointers are nested too much");
+			return false;
+		}
+		llen = *p;
+		if (llen == 0) {
+			if (!got_compression) {
+				/* In case of compression we have already decremented the processing position */
+				new_remain -= sizeof (uint8_t);
+				new_pos += sizeof (uint8_t);
+			}
+			break;
+		}
+		else if ((llen & DNS_COMPRESSION_BITS)) {
+			if (end - p > 1) {
+				ptrs ++;
+				llen = UNCOMPRESS_DNS_OFFSET(p);
+				l = rdns_decompress_label (in, &llen, end - in);
+				if (l == NULL) {
+					rdns_info ("invalid DNS pointer");
+					return false;
+				}
+				if (!got_compression) {
+					/* Our label processing is finished actually */
+					new_remain -= sizeof (uint16_t);
+					new_pos += sizeof (uint16_t);
+					got_compression = true;
+				}
+				if (l < in || l > begin + length) {
+					rdns_info  ("invalid pointer in DNS packet");
+					return false;
+				}
+				begin = l;
+				length = end - begin;
+				p = l + *l + 1;
+				namelen += *l;
+				labels ++;
+			}
+			else {
+				rdns_info ("DNS packet has incomplete compressed label, input length: %d bytes, remain: %d",
+						*remain, new_remain);
+				return false;
+			}
+		}
+		else {
+			namelen += llen;
+			p += llen + 1;
+			labels ++;
+			if (!got_compression) {
+				new_remain -= llen + 1;
+				new_pos += llen + 1;
+			}
+		}
+	}
+
+	if (!make_name) {
+		goto end;
+	}
+	*target = malloc (namelen + labels + 3);
+	t = (uint8_t *)*target;
+	p = *pos;
+	begin = *pos;
+	length = *remain;
+	/* Now copy labels to name */
+	while (p - begin < length) {
+		llen = *p;
+		if (llen == 0) {
+			break;
+		}
+		else if (llen & DNS_COMPRESSION_BITS) {
+			llen = UNCOMPRESS_DNS_OFFSET(p);
+			l = rdns_decompress_label (in, &llen, end - in);
+			begin = l;
+			length = end - begin;
+			p = l + *l + 1;
+			memcpy (t, l + 1, *l);
+			t += *l;
+			*t ++ = '.';
+		}
+		else {
+			memcpy (t, p + 1, *p);
+			t += *p;
+			*t ++ = '.';
+			p += *p + 1;
+		}
+	}
+	if (t > (uint8_t *)*target) {
+		*(t - 1) = '\0';
+	}
+	else {
+		/* Handle empty labels */
+		**target = '\0';
+	}
+end:
+	*remain = new_remain;
+	*pos = new_pos;
+
+	return true;
+}
+
+#define GET8(x) do {(x) = ((*p)); p += sizeof (uint8_t); *remain -= sizeof (uint8_t); } while(0)
+#define GET16(x) do {(x) = ((*p) << 8) + *(p + 1); p += sizeof (uint16_t); *remain -= sizeof (uint16_t); } while(0)
+#define GET32(x) do {(x) = ((*p) << 24) + ((*(p + 1)) << 16) + ((*(p + 2)) << 8) + *(p + 3); p += sizeof (uint32_t); *remain -= sizeof (uint32_t); } while(0)
+#define SKIP(type) do { p += sizeof(type); *remain -= sizeof(type); } while (0)
+
+int
+rdns_parse_rr (struct rdns_resolver *resolver,
+		uint8_t *in, struct rdns_reply_entry *elt, uint8_t **pos,
+		struct rdns_reply *rep, int *remain)
+{
+	uint8_t *p = *pos, parts;
+	uint16_t type, datalen, txtlen, copied;
+	int32_t ttl;
+	bool parsed = false;
+
+	/* Skip the whole name */
+	if (! rdns_parse_labels (resolver, in, NULL, &p, rep, remain, false)) {
+		rdns_info ("bad RR name");
+		return -1;
+	}
+	if (*remain < (int)sizeof (uint16_t) * 6) {
+		rdns_info ("stripped dns reply: %d bytes remain", *remain);
+		return -1;
+	}
+	GET16 (type);
+	/* Skip class */
+	SKIP (uint16_t);
+	GET32 (ttl);
+	GET16 (datalen);
+	elt->type = type;
+	/* Now p points to RR data */
+	switch (type) {
+	case DNS_T_A:
+		if (!(datalen & 0x3) && datalen <= *remain) {
+			memcpy (&elt->content.a.addr, p, sizeof (struct in_addr));
+			p += datalen;
+			*remain -= datalen;
+			parsed = true;
+		}
+		else {
+			rdns_info ("corrupted A record");
+			return -1;
+		}
+		break;
+	case DNS_T_AAAA:
+		if (datalen == sizeof (struct in6_addr) && datalen <= *remain) {
+			memcpy (&elt->content.aaa.addr, p, sizeof (struct in6_addr));
+			p += datalen;
+			*remain -= datalen;
+			parsed = true;
+		}
+		else {
+			rdns_info ("corrupted AAAA record");
+			return -1;
+		}
+		break;
+	case DNS_T_PTR:
+		if (! rdns_parse_labels (resolver, in, &elt->content.ptr.name, &p,
+				rep, remain, true)) {
+			rdns_info ("invalid labels in PTR record");
+			return -1;
+		}
+		parsed = true;
+		break;
+	case DNS_T_NS:
+		if (! rdns_parse_labels (resolver, in, &elt->content.ns.name, &p,
+				rep, remain, true)) {
+			rdns_info ("invalid labels in NS record");
+			return -1;
+		}
+		parsed = true;
+		break;
+	case DNS_T_SOA:
+		if (! rdns_parse_labels (resolver, in, &elt->content.soa.mname, &p,
+				rep, remain, true)) {
+			rdns_info ("invalid labels in NS record");
+			return -1;
+		}
+		if (! rdns_parse_labels (resolver, in, &elt->content.soa.admin, &p,
+				rep, remain, true)) {
+			rdns_info ("invalid labels in NS record");
+			return -1;
+		}
+		GET32 (elt->content.soa.serial);
+		GET32 (elt->content.soa.refresh);
+		GET32 (elt->content.soa.retry);
+		GET32 (elt->content.soa.expire);
+		GET32 (elt->content.soa.minimum);
+		parsed = true;
+		break;
+	case DNS_T_MX:
+		GET16 (elt->content.mx.priority);
+		if (! rdns_parse_labels (resolver, in, &elt->content.mx.name, &p,
+				rep, remain, true)) {
+			rdns_info ("invalid labels in MX record");
+			return -1;
+		}
+		parsed = true;
+		break;
+	case DNS_T_TXT:
+	case DNS_T_SPF:
+		elt->content.txt.data = malloc (datalen + 1);
+		if (elt->content.txt.data == NULL) {
+			rdns_err ("failed to allocate %d bytes for TXT record", (int)datalen + 1);
+			return -1;
+		}
+		/* Now we should compose data from parts */
+		copied = 0;
+		parts = 0;
+		while (copied + parts < datalen) {
+			txtlen = *p;
+			if (txtlen + copied + parts <= datalen) {
+				parts ++;
+				memcpy (elt->content.txt.data + copied, p + 1, txtlen);
+				copied += txtlen;
+				p += txtlen + 1;
+				*remain -= txtlen + 1;
+			}
+			else {
+				break;
+			}
+		}
+		*(elt->content.txt.data + copied) = '\0';
+		parsed = true;
+		elt->type = RDNS_REQUEST_TXT;
+		break;
+	case DNS_T_SRV:
+		if (p - *pos > (int)(*remain - sizeof (uint16_t) * 3)) {
+			rdns_info ("stripped dns reply while reading SRV record");
+			return -1;
+		}
+		GET16 (elt->content.srv.priority);
+		GET16 (elt->content.srv.weight);
+		GET16 (elt->content.srv.port);
+		if (! rdns_parse_labels (resolver, in, &elt->content.srv.target,
+				&p, rep, remain, true)) {
+			rdns_info ("invalid labels in SRV record");
+			return -1;
+		}
+		parsed = true;
+		break;
+	case DNS_T_TLSA:
+		if (p - *pos > (int)(*remain - sizeof (uint8_t) * 3) || datalen <= 3) {
+			rdns_info ("stripped dns reply while reading TLSA record");
+			return -1;
+		}
+		GET8 (elt->content.tlsa.usage);
+		GET8 (elt->content.tlsa.selector);
+		GET8 (elt->content.tlsa.match_type);
+		datalen -= 3;
+		elt->content.tlsa.data = malloc (datalen);
+		if (elt->content.tlsa.data == NULL) {
+			rdns_err ("failed to allocate %d bytes for TLSA record", (int)datalen + 1);
+			return -1;
+		}
+		elt->content.tlsa.datalen = datalen;
+		memcpy (elt->content.tlsa.data, p, datalen);
+		p += datalen;
+		*remain -= datalen;
+		parsed = true;
+		break;
+	case DNS_T_CNAME:
+		/* Skip cname records */
+		p += datalen;
+		*remain -= datalen;
+		break;
+	default:
+		rdns_debug ("unexpected RR type: %d", type);
+		p += datalen;
+		*remain -= datalen;
+		break;
+	}
+	*pos = p;
+
+	if (parsed) {
+		elt->ttl = ttl;
+		return 1;
+	}
+	return 0;
+}