Adding upstream version 3.0.5.upstream/3.0.5upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 781 insertions, 0 deletions

diff --git a/src/libknot/dname.c b/src/libknot/dname.c
new file mode 100644
index 0000000..0643971
--- /dev/null
+++ b/src/libknot/dname.c
@@ -0,0 +1,781 @@
+/*  Copyright (C) 2020 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz>
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "libknot/attribute.h"
+#include "libknot/consts.h"
+#include "libknot/dname.h"
+#include "libknot/errcode.h"
+#include "libknot/packet/wire.h"
+#include "contrib/ctype.h"
+#include "contrib/mempattern.h"
+#include "contrib/tolower.h"
+
+static bool label_is_equal(const uint8_t *lb1, const uint8_t *lb2, bool no_case)
+{
+	if (*lb1 != *lb2) {
+		return false;
+	}
+
+	if (no_case) {
+		uint8_t len = *lb1;
+		for (uint8_t i = 1; i <= len; i++) {
+			if (knot_tolower(lb1[i]) != knot_tolower(lb2[i])) {
+				return false;
+			}
+		}
+
+		return true;
+	} else {
+		return memcmp(lb1 + 1, lb2 + 1, *lb1) == 0;
+	}
+}
+
+/*!
+ * \brief Align name end-to-end and return number of common suffix labels.
+ *
+ * \param d1         Domain name1.
+ * \param d1_labels  Number of labels in d1.
+ * \param d2         Domain name2.
+ * \param d2_labels  Number of labels in d2.
+ */
+static int dname_align(const uint8_t **d1, uint8_t d1_labels,
+                       const uint8_t **d2, uint8_t d2_labels)
+{
+	assert(d1 && d2);
+
+	for (unsigned j = d1_labels; j < d2_labels; ++j) {
+		*d2 = knot_wire_next_label(*d2, NULL);
+	}
+
+	for (unsigned j = d2_labels; j < d1_labels; ++j) {
+		*d1 = knot_wire_next_label(*d1, NULL);
+	}
+
+	return (d1_labels < d2_labels) ? d1_labels : d2_labels;
+}
+
+_public_
+int knot_dname_wire_check(const uint8_t *name, const uint8_t *endp,
+                          const uint8_t *pkt)
+{
+	if (name == NULL || name == endp) {
+		return KNOT_EINVAL;
+	}
+
+	int wire_len = 0;
+	int name_len = 1; /* Keep \x00 terminal label in advance. */
+	bool is_compressed = false;
+
+	while (*name != '\0') {
+		/* Check bounds (must have at least 2 octets remaining). */
+		if (name + 2 > endp) {
+			return KNOT_EMALF;
+		}
+
+		if (knot_wire_is_pointer(name)) {
+			/* Check that the pointer points backwards
+			 * otherwise it could result in infinite loop
+			 */
+			if (pkt == NULL) {
+				return KNOT_EINVAL;
+			}
+			uint16_t ptr = knot_wire_get_pointer(name);
+			if (ptr >= (name - pkt)) {
+				return KNOT_EMALF;
+			}
+
+			name = pkt + ptr; /* Hop to compressed label */
+			if (!is_compressed) { /* Measure compressed size only */
+				wire_len += sizeof(uint16_t);
+				is_compressed = true;
+			}
+		} else {
+			/* Check label length. */
+			if (*name > KNOT_DNAME_MAXLABELLEN) {
+				return KNOT_EMALF;
+			}
+			/* Check if there's enough space. */
+			int lblen = *name + 1;
+			if (name_len + lblen > KNOT_DNAME_MAXLEN) {
+				return KNOT_EMALF;
+			}
+			/* Update wire size only for noncompressed part. */
+			name_len += lblen;
+			if (!is_compressed) {
+				wire_len += lblen;
+			}
+			/* Hop to next label. */
+			name += lblen;
+		}
+
+		/* Check bounds (must have at least 1 octet). */
+		if (name + 1 > endp) {
+			return KNOT_EMALF;
+		}
+	}
+
+	if (!is_compressed) { /* Terminal label. */
+		wire_len += 1;
+	}
+
+	return wire_len;
+}
+
+_public_
+size_t knot_dname_store(knot_dname_storage_t dst, const knot_dname_t *name)
+{
+	if (dst == NULL || name == NULL) {
+		return 0;
+	}
+
+	size_t len = knot_dname_size(name);
+	assert(len <= KNOT_DNAME_MAXLEN);
+	memcpy(dst, name, len);
+
+	return len;
+}
+
+_public_
+knot_dname_t *knot_dname_copy(const knot_dname_t *name, knot_mm_t *mm)
+{
+	if (name == NULL) {
+		return NULL;
+	}
+
+	size_t len = knot_dname_size(name);
+	knot_dname_t *dst = mm_alloc(mm, len);
+	if (dst == NULL) {
+		return NULL;
+	}
+	memcpy(dst, name, len);
+
+	return dst;
+}
+
+_public_
+int knot_dname_to_wire(uint8_t *dst, const knot_dname_t *src, size_t maxlen)
+{
+	if (dst == NULL || src == NULL) {
+		return KNOT_EINVAL;
+	}
+
+	size_t len = knot_dname_size(src);
+	if (len > maxlen) {
+		return KNOT_ESPACE;
+	}
+	memcpy(dst, src, len);
+
+	return len;
+}
+
+_public_
+int knot_dname_unpack(uint8_t *dst, const knot_dname_t *src,
+                      size_t maxlen, const uint8_t *pkt)
+{
+	if (dst == NULL || src == NULL) {
+		return KNOT_EINVAL;
+	}
+
+	/* Seek first real label occurrence. */
+	src = knot_wire_seek_label(src, pkt);
+
+	/* Unpack rest of the labels. */
+	int len = 0;
+	while (*src != '\0') {
+		uint8_t lblen = *src + 1;
+		if (len + lblen > maxlen) {
+			return KNOT_ESPACE;
+		}
+		memcpy(dst + len, src, lblen);
+		len += lblen;
+		src = knot_wire_next_label(src, pkt);
+	}
+
+	/* Terminal label */
+	if (len + 1 > maxlen) {
+		return KNOT_EINVAL;
+	}
+
+	*(dst + len) = '\0';
+	return len + 1;
+}
+
+_public_
+char *knot_dname_to_str(char *dst, const knot_dname_t *name, size_t maxlen)
+{
+	if (name == NULL) {
+		return NULL;
+	}
+
+	size_t dname_size = knot_dname_size(name);
+
+	/* Check the size for len(dname) + 1 char termination. */
+	size_t alloc_size = (dst == NULL) ? dname_size + 1 : maxlen;
+	if (alloc_size < dname_size + 1) {
+		return NULL;
+	}
+
+	char *res = (dst == NULL) ? malloc(alloc_size) : dst;
+	if (res == NULL) {
+		return NULL;
+	}
+
+	uint8_t label_len = 0;
+	size_t  str_len = 0;
+
+	for (unsigned i = 0; i < dname_size; i++) {
+		uint8_t c = name[i];
+
+		/* Read next label size. */
+		if (label_len == 0) {
+			label_len = c;
+
+			/* Write label separation. */
+			if (str_len > 0 || dname_size == 1) {
+				if (alloc_size <= str_len + 1) {
+					goto dname_to_str_failed;
+				}
+				res[str_len++] = '.';
+			}
+
+			continue;
+		}
+
+		if (is_alnum(c) || c == '-' || c == '_' || c == '*' ||
+		    c == '/') {
+			if (alloc_size <= str_len + 1) {
+				goto dname_to_str_failed;
+			}
+			res[str_len++] = c;
+		} else if (is_punct(c) && c != '#') {
+			/* Exclusion of '#' character is to avoid possible
+			 * collision with rdata hex notation '\#'. So it is
+			 * encoded in \ddd notation.
+			 */
+
+			if (dst != NULL) {
+				if (maxlen <= str_len + 2) {
+					goto dname_to_str_failed;
+				}
+			} else {
+				/* Extend output buffer for \x format. */
+				alloc_size += 1;
+				char *extended = realloc(res, alloc_size);
+				if (extended == NULL) {
+					goto dname_to_str_failed;
+				}
+				res = extended;
+			}
+
+			/* Write encoded character. */
+			res[str_len++] = '\\';
+			res[str_len++] = c;
+		} else {
+			if (dst != NULL) {
+				if (maxlen <= str_len + 4) {
+					goto dname_to_str_failed;
+				}
+			} else {
+				/* Extend output buffer for \DDD format. */
+				alloc_size += 3;
+				char *extended = realloc(res, alloc_size);
+				if (extended == NULL) {
+					goto dname_to_str_failed;
+				}
+				res = extended;
+			}
+
+			/* Write encoded character. */
+			int ret = snprintf(res + str_len, alloc_size - str_len,
+			                   "\\%03u", c);
+			if (ret <= 0 || ret >= alloc_size - str_len) {
+				goto dname_to_str_failed;
+			}
+
+			str_len += ret;
+		}
+
+		label_len--;
+	}
+
+	/* String_termination. */
+	assert(str_len < alloc_size);
+	res[str_len] = 0;
+
+	return res;
+
+dname_to_str_failed:
+
+	if (dst == NULL) {
+		free(res);
+	}
+
+	return NULL;
+}
+
+_public_
+knot_dname_t *knot_dname_from_str(uint8_t *dst, const char *name, size_t maxlen)
+{
+	if (name == NULL) {
+		return NULL;
+	}
+
+	size_t name_len = strlen(name);
+	if (name_len == 0) {
+		return NULL;
+	}
+
+	/* Wire size estimation. */
+	size_t alloc_size = maxlen;
+	if (dst == NULL) {
+		/* Check for the root label. */
+		if (name[0] == '.') {
+			/* Just the root dname can begin with a dot. */
+			if (name_len > 1) {
+				return NULL;
+			}
+			name_len = 0; /* Skip the following parsing. */
+			alloc_size = 1;
+		} else if (name[name_len - 1] != '.') { /* Check for non-FQDN. */
+			alloc_size = 1 + name_len + 1;
+		} else {
+			alloc_size = 1 + name_len ; /* + 1 ~ first label length. */
+		}
+	}
+
+	/* The minimal (root) dname takes 1 byte. */
+	if (alloc_size == 0) {
+		return NULL;
+	}
+
+	/* Check the maximal wire size. */
+	if (alloc_size > KNOT_DNAME_MAXLEN) {
+		alloc_size = KNOT_DNAME_MAXLEN;
+	}
+
+	/* Prepare output buffer. */
+	uint8_t *wire = (dst == NULL) ? malloc(alloc_size) : dst;
+	if (wire == NULL) {
+		return NULL;
+	}
+
+	uint8_t *label = wire;
+	uint8_t *wire_pos = wire + 1;
+	uint8_t *wire_end = wire + alloc_size;
+
+	/* Initialize the first label (root label). */
+	*label = 0;
+
+	const uint8_t *ch = (const uint8_t *)name;
+	const uint8_t *end = ch + name_len;
+
+	while (ch < end) {
+		/* Check the output buffer for enough space. */
+		if (wire_pos >= wire_end) {
+			goto dname_from_str_failed;
+		}
+
+		switch (*ch) {
+		case '.':
+			/* Check for invalid zero-length label. */
+			if (*label == 0 && name_len > 1) {
+				goto dname_from_str_failed;
+			}
+			label = wire_pos++;
+			*label = 0;
+			break;
+		case '\\':
+			ch++;
+
+			/* At least one more character is required OR
+			 * check for maximal label length.
+			 */
+			if (ch == end || ++(*label) > KNOT_DNAME_MAXLABELLEN) {
+				goto dname_from_str_failed;
+			}
+
+			/* Check for \DDD notation. */
+			if (is_digit(*ch)) {
+				/* Check for next two digits. */
+				if (ch + 2 >= end ||
+				    !is_digit(*(ch + 1)) ||
+				    !is_digit(*(ch + 2))) {
+					goto dname_from_str_failed;
+				}
+
+				uint32_t num = (*(ch + 0) - '0') * 100 +
+				               (*(ch + 1) - '0') * 10 +
+				               (*(ch + 2) - '0') * 1;
+				if (num > UINT8_MAX) {
+					goto dname_from_str_failed;
+				}
+				*(wire_pos++) = num;
+				ch +=2;
+			} else {
+				*(wire_pos++) = *ch;
+			}
+			break;
+		default:
+			/* Check for maximal label length. */
+			if (++(*label) > KNOT_DNAME_MAXLABELLEN) {
+				goto dname_from_str_failed;
+			}
+			*(wire_pos++) = *ch;
+		}
+		ch++;
+	}
+
+	/* Check for non-FQDN name. */
+	if (*label > 0) {
+		if (wire_pos >= wire_end) {
+			goto dname_from_str_failed;
+		}
+		*(wire_pos++) = 0;
+	}
+
+	/* Reduce output buffer if the size is overestimated. */
+	if (wire_pos < wire_end && dst == NULL) {
+		uint8_t *reduced = realloc(wire, wire_pos - wire);
+		if (reduced == NULL) {
+			goto dname_from_str_failed;
+		}
+		wire = reduced;
+	}
+
+	return wire;
+
+dname_from_str_failed:
+
+	if (dst == NULL) {
+		free(wire);
+	}
+
+	return NULL;
+}
+
+_public_
+void knot_dname_to_lower(knot_dname_t *name)
+{
+	if (name == NULL) {
+		return;
+	}
+
+	while (*name != '\0') {
+		uint8_t len = *name;
+		for (uint8_t i = 1; i <= len; ++i) {
+			name[i] = knot_tolower(name[i]);
+		}
+		name += 1 + len;
+	}
+}
+
+_public_
+size_t knot_dname_size(const knot_dname_t *name)
+{
+	if (name == NULL) {
+		return 0;
+	}
+
+	/* Count name size without terminal label. */
+	size_t len = 0;
+	while (*name != '\0' && !knot_wire_is_pointer(name)) {
+		uint8_t lblen = *name + 1;
+		len += lblen;
+		name += lblen;
+	}
+
+	if (knot_wire_is_pointer(name)) {
+		/* Add 2-octet compression pointer. */
+		return len + 2;
+	} else {
+		/* Add 1-octet terminal label. */
+		return len + 1;
+	}
+}
+
+_public_
+size_t knot_dname_realsize(const knot_dname_t *name, const uint8_t *pkt)
+{
+	if (name == NULL) {
+		return 0;
+	}
+
+	/* Seek first real label occurrence. */
+	name = knot_wire_seek_label(name, pkt);
+
+	size_t len = 0;
+	while (*name != '\0') {
+		len += *name + 1;
+		name = knot_wire_next_label(name, pkt);
+	}
+
+	/* Add 1-octet terminal label. */
+	return len + 1;
+}
+
+_public_
+size_t knot_dname_matched_labels(const knot_dname_t *d1, const knot_dname_t *d2)
+{
+	/* Count labels. */
+	size_t l1 = knot_dname_labels(d1, NULL);
+	size_t l2 = knot_dname_labels(d2, NULL);
+	if (l1 == 0 || l2 == 0) {
+		return 0;
+	}
+
+	/* Align end-to-end to common suffix. */
+	int common = dname_align(&d1, l1, &d2, l2);
+
+	/* Count longest chain leading to root label. */
+	size_t matched = 0;
+	while (common > 0) {
+		if (label_is_equal(d1, d2, false)) {
+			++matched;
+		} else {
+			matched = 0; /* Broken chain. */
+		}
+
+		/* Next label. */
+		d1 = knot_wire_next_label(d1, NULL);
+		d2 = knot_wire_next_label(d2, NULL);
+		--common;
+	}
+
+	return matched;
+}
+
+_public_
+knot_dname_t *knot_dname_replace_suffix(const knot_dname_t *name, unsigned labels,
+                                        const knot_dname_t *suffix, knot_mm_t *mm)
+{
+	if (name == NULL) {
+		return NULL;
+	}
+
+	/* Calculate prefix and suffix lengths. */
+	size_t dname_lbs = knot_dname_labels(name, NULL);
+	if (dname_lbs < labels) {
+		return NULL;
+	}
+	size_t prefix_lbs = dname_lbs - labels;
+
+	size_t prefix_len = knot_dname_prefixlen(name, prefix_lbs, NULL);
+	size_t suffix_len = knot_dname_size(suffix);
+	if (prefix_len == 0 || suffix_len == 0) {
+		return NULL;
+	}
+
+	/* Create target name. */
+	size_t new_len = prefix_len + suffix_len;
+	knot_dname_t *out = mm_alloc(mm, new_len);
+	if (out == NULL) {
+		return NULL;
+	}
+
+	/* Copy prefix. */
+	uint8_t *dst = out;
+	while (prefix_lbs > 0) {
+		memcpy(dst, name, *name + 1);
+		dst += *name + 1;
+		name = knot_wire_next_label(name, NULL);
+		--prefix_lbs;
+	}
+
+	/* Copy suffix. */
+	while (*suffix != '\0') {
+		memcpy(dst, suffix, *suffix + 1);
+		dst += *suffix + 1;
+		suffix = knot_wire_next_label(suffix, NULL);
+	}
+
+	*dst = '\0';
+	return out;
+}
+
+_public_
+void knot_dname_free(knot_dname_t *name, knot_mm_t *mm)
+{
+	if (name == NULL) {
+		return;
+	}
+
+	mm_free(mm, name);
+}
+
+_public_
+int knot_dname_cmp(const knot_dname_t *d1, const knot_dname_t *d2)
+{
+	if (d1 == NULL) {
+		return -1;
+	} else if (d2 == NULL) {
+		return 1;
+	}
+
+	/* Convert to lookup format. */
+	knot_dname_storage_t lf1_storage;
+	knot_dname_storage_t lf2_storage;
+
+	uint8_t *lf1 = knot_dname_lf(d1, lf1_storage);
+	uint8_t *lf2 = knot_dname_lf(d2, lf2_storage);
+	assert(lf1 && lf2);
+
+	/* Compare common part. */
+	uint8_t common = lf1[0];
+	if (common > lf2[0]) {
+		common = lf2[0];
+	}
+	int ret = memcmp(lf1 + 1, lf2 + 1, common);
+	if (ret != 0) {
+		return ret;
+	}
+
+	/* If they match, compare lengths. */
+	if (lf1[0] < lf2[0]) {
+		return -1;
+	} else if (lf1[0] > lf2[0]) {
+		return 1;
+	} else {
+		return 0;
+	}
+}
+
+inline static bool dname_is_equal(const knot_dname_t *d1, const knot_dname_t *d2, bool no_case)
+{
+	if (d1 == NULL || d2 == NULL) {
+		return false;
+	}
+
+	while (*d1 != '\0' || *d2 != '\0') {
+		if (label_is_equal(d1, d2, no_case)) {
+			d1 = knot_wire_next_label(d1, NULL);
+			d2 = knot_wire_next_label(d2, NULL);
+		} else {
+			return false;
+		}
+	}
+
+	return true;
+}
+
+_public_
+bool knot_dname_is_equal(const knot_dname_t *d1, const knot_dname_t *d2)
+{
+	return dname_is_equal(d1, d2, false);
+}
+
+_public_
+bool knot_dname_is_case_equal(const knot_dname_t *d1, const knot_dname_t *d2)
+{
+	return dname_is_equal(d1, d2, true);
+}
+
+_public_
+size_t knot_dname_prefixlen(const uint8_t *name, unsigned nlabels, const uint8_t *pkt)
+{
+	if (name == NULL) {
+		return 0;
+	}
+
+	/* Zero labels means no prefix. */
+	if (nlabels == 0) {
+		return 0;
+	}
+
+	/* Seek first real label occurrence. */
+	name = knot_wire_seek_label(name, pkt);
+
+	size_t len = 0;
+	while (*name != '\0') {
+		len += *name + 1;
+		name = knot_wire_next_label(name, pkt);
+		if (--nlabels == 0) { /* Count N first labels only. */
+			break;
+		}
+	}
+
+	return len;
+}
+
+_public_
+size_t knot_dname_labels(const uint8_t *name, const uint8_t *pkt)
+{
+	if (name == NULL) {
+		return 0;
+	}
+
+	size_t count = 0;
+	while (*name != '\0') {
+		++count;
+		name = knot_wire_next_label(name, pkt);
+		if (name == NULL) {
+			return 0;
+		}
+	}
+
+	return count;
+}
+
+_public_
+uint8_t *knot_dname_lf(const knot_dname_t *src, knot_dname_storage_t storage)
+{
+	if (src == NULL || storage == NULL) {
+		return NULL;
+	}
+
+	/* Writing from the end. */
+	storage[KNOT_DNAME_MAXLEN - 1] = '\0';
+	size_t idx = KNOT_DNAME_MAXLEN - 1;
+
+	while (*src != 0) {
+		size_t len = *src + 1;
+
+		assert(idx >= len);
+		idx -= len;
+		memcpy(&storage[idx], src, len);
+		storage[idx] = '\0';
+
+		src += len;
+	}
+
+	assert(KNOT_DNAME_MAXLEN >= 1 + idx);
+	storage[idx] = KNOT_DNAME_MAXLEN - 1 - idx;
+
+	return &storage[idx];
+}
+
+_public_
+int knot_dname_in_bailiwick(const knot_dname_t *name, const knot_dname_t *bailiwick)
+{
+	if (name == NULL || bailiwick == NULL) {
+		return KNOT_EINVAL;
+	}
+
+	int label_diff = knot_dname_labels(name, NULL) - knot_dname_labels(bailiwick, NULL);
+	if (label_diff < 0) {
+		return KNOT_EOUTOFZONE;
+	}
+
+	for (int i = 0; i < label_diff; ++i) {
+		name = knot_wire_next_label(name, NULL);
+	}
+
+	return knot_dname_is_equal(name, bailiwick) ? label_diff : KNOT_EOUTOFZONE;
+}