1 files changed, 343 insertions, 0 deletions
diff --git a/src/utils/common/params.c b/src/utils/common/params.c
new file mode 100644
index 0000000..4db4b9e
--- /dev/null
+++ b/src/utils/common/params.c
@@ -0,0 +1,343 @@
+/*  Copyright (C) 2022 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 <arpa/inet.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <netinet/in.h>
+#include <sys/socket.h>
+
+#ifdef LIBIDN
+#include LIBIDN_HEADER
+#endif
+
+#include "utils/common/params.h"
+#include "utils/common/msg.h"
+#include "utils/common/resolv.h"
+#include "utils/common/token.h"
+#include "libknot/libknot.h"
+#include "contrib/macros.h"
+#include "contrib/mempattern.h"
+#include "contrib/openbsd/strlcpy.h"
+#include "contrib/strtonum.h"
+
+#define IPV4_REVERSE_DOMAIN	"in-addr.arpa."
+#define IPV6_REVERSE_DOMAIN	"ip6.arpa."
+
+char *name_from_idn(const char *idn_name) {
+#ifdef LIBIDN
+	char *name = NULL;
+
+	int rc = idna_to_ascii_lz(idn_name, &name, 0);
+	if (rc != IDNA_SUCCESS) {
+		ERR("IDNA (%s)", idna_strerror(rc));
+		return NULL;
+	}
+
+	return name;
+#endif
+	return strdup(idn_name);
+}
+
+void name_to_idn(char **name) {
+#ifdef LIBIDN
+	char *idn_name = NULL;
+
+	int rc = idna_to_unicode_8zlz(*name, &idn_name, 0);
+	if (rc != IDNA_SUCCESS) {
+		return;
+	}
+
+	free(*name);
+	*name = idn_name;
+#endif
+	return;
+}
+
+/*!
+ * \brief Checks if string is a prefix of reference string.
+ *
+ * \param pref		Prefix string.
+ * \param pref_len	Prefix length.
+ * \param str		Reference string (must have trailing zero).
+ *
+ * \retval -1		\a pref is not a prefix of \a str.
+ * \retval  0<=		number of chars after prefix \a pref in \a str.
+ */
+static int cmp_prefix(const char *pref, const size_t pref_len,
+                      const char *str)
+{
+	size_t i = 0;
+	while (1) {
+		// Different characters => NOT prefix.
+		if (pref[i] != str[i]) {
+			return -1;
+		}
+
+		i++;
+
+		// Pref IS a prefix of pref.
+		if (i == pref_len) {
+			size_t rest = 0;
+			while (str[i + rest] != '\0') {
+				rest++;
+			}
+			return rest;
+		// Pref is longer then ref => NOT prefix.
+		} else if (str[i] == '\0') {
+			return -1;
+		}
+	}
+}
+
+int best_param(const char *str, const size_t str_len, const param_t *tbl,
+               bool *unique)
+{
+	if (str == NULL || str_len == 0 || tbl == NULL) {
+		DBG_NULL;
+		return KNOT_EINVAL;
+	}
+
+	int best_pos = -1;
+	int best_match = INT_MAX;
+	size_t matches = 0;
+	for (int i = 0; tbl[i].name != NULL; i++) {
+		int ret = cmp_prefix(str, str_len, tbl[i].name);
+		switch (ret) {
+		case -1:
+			continue;
+		case 0:
+			*unique = true;
+			return i;
+		default:
+			if (ret < best_match) {
+				best_pos = i;
+				best_match = ret;
+			}
+			matches++;
+		}
+	}
+
+	switch (matches) {
+	case 0:
+		return KNOT_ENOTSUP;
+	case 1:
+		*unique = true;
+		return best_pos;
+	default:
+		*unique = false;
+		return best_pos;
+	}
+}
+
+char *get_reverse_name(const char *name)
+{
+	struct in_addr	addr4;
+	struct in6_addr	addr6;
+	int		ret;
+	char		buf[128] = "\0";
+
+	if (name == NULL) {
+		DBG_NULL;
+		return NULL;
+	}
+
+	// Check name for IPv4 address, IPv6 address or other.
+	if (inet_pton(AF_INET, name, &addr4) == 1) {
+		uint32_t num = ntohl(addr4.s_addr);
+
+		// Create IPv4 reverse FQD name.
+		ret = snprintf(buf, sizeof(buf), "%u.%u.%u.%u.%s",
+		               (num >>  0) & 0xFF, (num >>  8) & 0xFF,
+		               (num >> 16) & 0xFF, (num >> 24) & 0xFF,
+		               IPV4_REVERSE_DOMAIN);
+		if (ret < 0 || (size_t)ret >= sizeof(buf)) {
+			return NULL;
+		}
+
+		return strdup(buf);
+	} else if (inet_pton(AF_INET6, name, &addr6) == 1) {
+		char	*pos = buf;
+		size_t  len = sizeof(buf);
+		uint8_t left, right;
+
+		// Create IPv6 reverse name.
+		for (int i = 15; i >= 0; i--) {
+			left = ((addr6.s6_addr)[i] & 0xF0) >> 4;
+			right = (addr6.s6_addr)[i] & 0x0F;
+
+			ret = snprintf(pos, len, "%x.%x.", right, left);
+			if (ret < 0 || (size_t)ret >= len) {
+				return NULL;
+			}
+
+			pos += ret;
+			len -= ret;
+		}
+
+		// Add IPv6 reverse domain.
+		ret = snprintf(pos, len, "%s", IPV6_REVERSE_DOMAIN);
+		if (ret < 0 || (size_t)ret >= len) {
+			return NULL;
+		}
+
+		return strdup(buf);
+	} else {
+		return NULL;
+	}
+}
+
+char *get_fqd_name(const char *name)
+{
+	char *fqd_name = NULL;
+
+	if (name == NULL) {
+		DBG_NULL;
+		return NULL;
+	}
+
+	size_t name_len = strlen(name);
+
+	// If the name is FQDN, make a copy.
+	if (name[name_len - 1] == '.') {
+		fqd_name = strdup(name);
+	// Else make a copy and append a trailing dot.
+	} else {
+		size_t fqd_name_size = name_len + 2;
+		fqd_name = malloc(fqd_name_size);
+		if (fqd_name != NULL) {
+			strlcpy(fqd_name, name, fqd_name_size);
+			fqd_name[name_len] = '.';
+			fqd_name[name_len + 1] = 0;
+		}
+	}
+
+	return fqd_name;
+}
+
+int params_parse_class(const char *value, uint16_t *rclass)
+{
+	if (value == NULL || rclass == NULL) {
+		DBG_NULL;
+		return KNOT_EINVAL;
+	}
+
+	if (knot_rrclass_from_string(value, rclass) == 0) {
+		return KNOT_EOK;
+	} else {
+		return KNOT_EINVAL;
+	}
+}
+
+int params_parse_type(const char *value, uint16_t *rtype, int64_t *serial,
+                      bool *notify)
+{
+	if (value == NULL || rtype == NULL || serial == NULL) {
+		DBG_NULL;
+		return KNOT_EINVAL;
+	}
+
+	// Find and parse type name.
+	size_t param_pos = strcspn(value, "=");
+	char *type_char = strndup(value, param_pos);
+
+	if (knot_rrtype_from_string(type_char, rtype) != 0) {
+		size_t cmp_len = MAX(strlen("NOTIFY"), param_pos);
+		if (strncasecmp(type_char, "NOTIFY", cmp_len) == 0) {
+			*rtype = KNOT_RRTYPE_SOA;
+			*notify = true;
+		} else {
+			free(type_char);
+			return KNOT_EINVAL;
+		}
+	} else {
+		*notify = false;
+	}
+
+	free(type_char);
+
+	// Parse additional parameter.
+	if (param_pos == strlen(value)) {
+		// IXFR requires serial parameter.
+		if (*rtype == KNOT_RRTYPE_IXFR) {
+			DBG("SOA serial is required for IXFR query");
+			return KNOT_EINVAL;
+		} else {
+			*serial = -1;
+		}
+	} else {
+		// Additional parameter is accepted for IXFR or NOTIFY.
+		if (*rtype == KNOT_RRTYPE_IXFR || *notify) {
+			const char *param_str = value + 1 + param_pos;
+			char *end;
+
+			// Convert string to serial.
+			unsigned long long num = strtoull(param_str, &end, 10);
+
+			// Check for bad serial string.
+			if (end == param_str || *end != '\0' || num > UINT32_MAX) {
+				DBG("bad SOA serial '%s'", param_str);
+				return KNOT_EINVAL;
+			}
+
+			*serial = num;
+		} else {
+			DBG("unsupported parameter '%s'", value);
+			return KNOT_EINVAL;
+		}
+	}
+
+	return KNOT_EOK;
+}
+
+int params_parse_server(const char *value, list_t *servers, const char *def_port)
+{
+	if (value == NULL || servers == NULL) {
+		DBG_NULL;
+		return KNOT_EINVAL;
+	}
+
+	// Add specified nameserver.
+	srv_info_t *server = parse_nameserver(value, def_port);
+	if (server == NULL) {
+		return KNOT_EINVAL;
+	}
+	add_tail(servers, (node_t *)server);
+
+	return KNOT_EOK;
+}
+
+int params_parse_wait(const char *value, int32_t *dst)
+{
+	if (value == NULL || dst == NULL) {
+		DBG_NULL;
+		return KNOT_EINVAL;
+	}
+
+	uint32_t num = 0;
+	int ret = str_to_u32(value, &num);
+	if (ret != KNOT_EOK) {
+		return ret;
+	}
+
+	if (num < 1 || num > INT32_MAX / 1000) {
+		num = INT32_MAX / 1000;
+	}
+
+	*dst = num;
+
+	return KNOT_EOK;
+}