Simplify parser interface and code

Exposing type and field information makes little sense. Applications are
required to interpret wire representation for handling queries. Unknown
types can simply be handled generically. Removing the information
simplifies the interface and code.

Fixes #98.

Author: k0ekk0ek

.github/workflows/build-test.yml

@@ -87,4 +87,4 @@ jobs:
           set -e -x
           cd build
           ctest -j 4 --output-on-failure -T test -C ${BUILD_TYPE:-RelWithDebInfo}
-          ZONE_TARGET=fallback ctest -j 4 --output-on-failure -T test -C ${BUILD_TYPE:-RelWithDebInfo}
+          ZONE_KERNEL=fallback ctest -j 4 --output-on-failure -T test -C ${BUILD_TYPE:-RelWithDebInfo}

CMakeLists.txt

@@ -145,9 +145,7 @@ target_include_directories(
               $<BUILD_INTERFACE:${CMAKE_CURRENT_BINARY_DIR}>)
 
 target_sources(zone PRIVATE
-  src/zone.c
-  src/log.c
-  src/fallback/parser.c)
+  src/zone.c src/fallback/parser.c)
 
 add_executable(zone-bench src/bench.c src/fallback/bench.c)
 target_include_directories(
@@ -227,7 +225,8 @@ foreach(match ${matches})
 endforeach()
 
 file(GENERATE OUTPUT config.h CONTENT "${template}")
-configure_file(src/fallback/endian.h.in fallback/endian.h @ONLY)
+# FIXME: we'll need to port this over to autoconf as well
+configure_file(src/generic/endian.h.in generic/endian.h @ONLY)
 
 
 if(BUILD_TESTING)

include/zone.h

@@ -1,5 +1,5 @@
 /*
- * zone.h -- (DNS) zone parser
+ * zone.h -- (DNS) presentation format parser
  *
  * Copyright (c) 2022-2023, NLnet Labs. All rights reserved.
  *
@@ -40,6 +40,8 @@ extern "C" {
 #define ZONE_CH (3u)
 /** Hesiod @rfc{1035} */
 #define ZONE_HS (4u)
+/** Any (QCLASS) @rfc{1035} */
+#define ZONE_ANY (255u)
 /** @} */
 
 /**
@@ -133,11 +135,11 @@ extern "C" {
 #define ZONE_NSEC (47u)
 /** DNS Public Key @rfc{4034} @rfc{3755} */
 #define ZONE_DNSKEY (48u)
-/** DHCID [RFC4701] */
+/** DHCID @rfc{4701} */
 #define ZONE_DHCID (49u)
-/** NSEC3 [RFC5155] */
+/** NSEC3 @rfc{5155} */
 #define ZONE_NSEC3 (50u)
-/** NSEC3PARAM [RFC5155] */
+/** NSEC3PARAM @rfc{5155} */
 #define ZONE_NSEC3PARAM (51u)
 /** TLSA @rfc{6698} */
 #define ZONE_TLSA (52u)
@@ -183,156 +185,9 @@ extern "C" {
 #define ZONE_DLV (32769u)
 /** @} */
 
-typedef struct zone_string zone_string_t;
-struct zone_string {
-  size_t length;
-  const char *data;
-};
-
-// FIXME: probably best to rename this to mnemonic to stay with DNS terminology?
-typedef struct zone_symbol zone_symbol_t;
-struct zone_symbol {
-  struct {
-    char data[24]; // zero padded for convenient vectorized comparison
-    size_t length;
-  } key;
-  uint32_t value;
-};
-
-typedef struct zone_table zone_table_t;
-struct zone_table {
-  size_t length;
-  const zone_symbol_t *symbols; // sorted for use with bsearch
-};
-
-/**
- * @brief Type of value defined by field
- *
- * Fields are defined by their binary representation, NOT their textual
- * representation. e.g. time-to-live and timestamp fields are encoded as
- * 32-bit integers on the wire. @ref type_qualifiers are used to complement
- * the type information. e.g. @ref ZONE_TTL and @ref ZONE_TIME can be used to
- * provide extra information regarding the aforementioned types.
- */
-typedef enum {
-  ZONE_INT8,
-  ZONE_INT16,
-  ZONE_INT32,
-  ZONE_IP4,
-  ZONE_IP6,
-  ZONE_NAME,
-  ZONE_STRING,
-  // (B)inary (L)arge (Ob)ject. Inspired by relational database terminology.
-  // Must be last.
-  ZONE_BLOB,
-  ZONE_ILNP64,
-  // hex fields
-  // ZONE_EUI48 (ZONE_HEX6?)
-  // ZONE_EUI64 (ZONE_HEX8?)
-  // miscellaneous fields
-  ZONE_SVC_PARAM, /**< SVCB service parameter */
-  ZONE_TYPE_BITMAP, /**< NSEC type bitmap */
-  ZONE_SERVICE_BITMAP /**< WKS service bitmap */
-} zone_type_t;
-
-/**
- * @defgroup type_qualifiers Type qualifiers
- *
- * Type qualifiers provide additional information for RDATA fields. Types
- * indicate the binary representation of an RDATA field, qualifier(s) can be
- * used to communicate semantics. e.g. a time-to-live is presented on the
- * wire as a 32-bit integer, ZONE_TTL can be used to signal the field
- * represents a time-to-live value.
- *
- * @note Some types allow for more than one qualifier to be specified, hence
- *       each qualifier is assigned a separate bit.
- *
- * @{
- */
-/**
- * @brief Type code (#ZONE_INT16)
- *
- * Type codes may appear in text by name or generic type notation @rfc{3597}.
- */
-#define ZONE_TYPE (1u << 0)
-/**
- * @brief Class code (#ZONE_INT16)
- *
- * Class codes may appear in text by name or generic class notation @rfc{3597}.
- */
-#define ZONE_CLASS (1u << 1)
-/**
- * @brief Time-to-live (TTL) (#ZONE_INT32)
- *
- * Time-to-live values may appear in text as numeric value (seconds) or in
- * "1h2m3s" notation (@e extension).
- */
-#define ZONE_TTL (1u << 2)
-/**
- * @brief Timestamp (#ZONE_INT32)
- *
- * Timestamps must be presented in text in "YYYYMMDDHHmmSS" notation.
- */
-#define ZONE_TIME (1u << 3)
-/** @brief Text representation is base16 (#ZONE_STRING or #ZONE_BLOB) */
-#define ZONE_BASE16 (1u << 4)
-/** @brief Text representation is base32 (#ZONE_BLOB) */
-#define ZONE_BASE32 (1u << 5)
-/** @brief Text representation is base64 (#ZONE_BLOB) */
-#define ZONE_BASE64 (1u << 6)
-/** @brief Name is compressed (#ZONE_NAME) */
-#define ZONE_COMPRESSED (1u << 7)
-/** @brief Name represents a mailbox (#ZONE_NAME) */
-#define ZONE_MAILBOX (1u << 8)
-/** @brief Name is converted to lower case for DNSSEC validation (#ZONE_NAME) */
-#define ZONE_LOWER_CASE (1u << 9)
-/** @brief Optional (#ZONE_NAME) */
-#define ZONE_OPTIONAL (1u << 10)
-/**
- * @brief May occur multiple times (#ZONE_STRING or #ZONE_SVC_PARAM)
- *
- * Field may occur multiple times. e.g. #ZONE_STRING in #ZONE_TXT or
- * #ZONE_SVC_PARAM in #ZONE_SVCB. Sequences must be the last field in the
- * record.
- */
-#define ZONE_SEQUENCE (1u << 11)
-
-#define ZONE_CAA_TAG (1u << 12)
-/** @} */
-
-typedef struct zone_field_info zone_field_info_t;
-struct zone_field_info {
-  zone_string_t name;
-  uint32_t type;
-  uint32_t qualifiers;
-  zone_table_t symbols;
-};
-
-/**
- * @defgroup options Type options
- * @brief Options for record types
- *
- * @{
- */
-#define ZONE_ANY (1<<2)
-#define ZONE_EXPERIMENTAL (1<<3)
-#define ZONE_OBSOLETE (1<<4)
-/** @} */
-
-typedef struct zone_type_info zone_type_info_t;
-struct zone_type_info {
-  zone_symbol_t name;
-  uint32_t options;
-  struct {
-    size_t length;
-    const zone_field_info_t *fields;
-  } rdata;
-};
-
 #define ZONE_BLOCK_SIZE (64)
 #define ZONE_WINDOW_SIZE (256 * ZONE_BLOCK_SIZE) // 16KB
 
-
 // tape capacity must be large enough to hold every token from a single
 // worst-case read (e.g. 64 consecutive line feeds). in practice a single
 // block will never contain 64 tokens, therefore, to optimize throughput,
@@ -350,10 +205,10 @@ struct zone_name_buffer {
   uint8_t octets[ ZONE_NAME_SIZE + ZONE_PADDING_SIZE ];
 };
 
+// FIXME: explain need for NSEC padding
 typedef struct zone_rdata_buffer zone_rdata_buffer_t;
 struct zone_rdata_buffer {
-  size_t length; /**< Length of RDATA stored in buffer */
-  uint8_t octets[ ZONE_RDATA_SIZE + 4096 /* nsec padding */ ];
+  uint8_t octets[ ZONE_RDATA_SIZE + 4096 /* NSEC padding */ ];
 };
 
 // @private
@@ -425,65 +280,42 @@ struct zone_parser;
 
 typedef void(*zone_log_t)(
   zone_parser_t *,
-  const char *, // file
-  size_t, // line
-  const char *, // function
   uint32_t, // category
   const char *, // message
   void *); // user data
 
 /**
  * @brief Write error message to active log handler.
  *
- * @note Direct use is discouraged. Use of #ZONE_LOG instead.
+ * The zone parser operates on a per-record base and therefore cannot detect
+ * errors that span records. e.g. SOA records being specified more than once.
+ * The user may print a message using the active log handler, keeping the
+ * error message format consistent.
  *
  * @param[in]  parser    Zone parser
- * @param[in]  file      Name of source file
- * @param[in]  line      Line number in source file
- * @param[in]  function  Name of function
  * @param[in]  category  Log category
  * @param[in]  format    Format string compatible with printf
  * @param[in]  ...       Variadic arguments corresponding to #format
  */
 ZONE_EXPORT void zone_log(
   zone_parser_t *parser,
-  const char *file,
-  size_t line,
-  const char *function,
   uint32_t category,
   const char *format,
   ...)
-zone_nonnull((1,2,4,6))
-zone_format_printf(6,7);
-
-/**
- * @brief Write log message to active log handler.
- *
- * The zone parser operates on a per-record base and therefore cannot detect
- * errors that span records. e.g. SOA records being specified more than once.
- * The user may print a message using the active log handler, keeping the
- * error message format consistent.
- *
- * @param[in]  parser    Zone parser
- * @param[in]  category  Log category
- * @param[in]  format    Format string compatible with printf
- * @param[in]  ...       Variadic arguments corresponding to @ref format
- */
-#define ZONE_LOG(parser, category, ...) \
-  zone_log(parser, __FILE__, __LINE__, __func__, category, __VA_ARGS__)
+zone_nonnull((1,3))
+zone_format_printf(3,4);
 
 typedef struct zone_name zone_name_t;
 struct zone_name {
   uint8_t length;
   uint8_t *octets;
 };
 
-// invoked for each record (host order). header (owner, type, class and ttl)
+// invoked for each resource record (host order). header (owner, type, class and ttl)
 // fields are passed individually for convenience. rdata fields can be visited
 // individually by means of the iterator
-typedef int32_t(*zone_add_t)(
+typedef int32_t(*zone_accept_t)(
   zone_parser_t *,
-  const zone_type_info_t *, // type information
   const zone_name_t *, // owner (length + octets)
   uint16_t, // type
   uint16_t, // class
@@ -493,16 +325,17 @@ typedef int32_t(*zone_add_t)(
   void *); // user data
 
 typedef struct {
-  /** Lax mode of operation. */
+  /** Non-strict mode of operation. */
   /** Authoritative servers may choose to be more lenient when operating as
-      as a secondary as data may have been transferred over AXFR/IXFR that
+      a secondary as data may have been transferred over AXFR/IXFR that
       would have triggered an error otherwise. */
-  bool secondary;
+  bool non_strict;
   /** Disable $INCLUDE directive. */
   /** Useful in setups where untrusted input may be offered. */
   bool no_includes;
   /** Enable 1h2m3s notations for TTLS. */
   bool pretty_ttls;
+  // FIXME: require origin to be in wire format? (#115)
   const char *origin;
   uint32_t default_ttl;
   uint16_t default_class;
@@ -512,13 +345,10 @@ typedef struct {
         custom callback was specified. */
     uint32_t categories;
     /** Callback used to write out log messages. */
-    zone_log_t write;
+    zone_log_t callback;
   } log;
   struct {
-    zone_add_t add;
-    // FIXME: more callbacks to be added at a later stage to support efficient
-    //        (de)serialization of AXFR/IXFR in text representation.
-    //zone_delete_t remove;
+    zone_accept_t callback;
   } accept;
 } zone_options_t;
 
@@ -568,21 +398,21 @@ struct zone_parser {
 /** Success */
 #define ZONE_SUCCESS (0)
 /** Syntax error */
-#define ZONE_SYNTAX_ERROR (-1)
+#define ZONE_SYNTAX_ERROR (-256)  // (-1 << 8)
 /** Semantic error */
-#define ZONE_SEMANTIC_ERROR (-2)
+#define ZONE_SEMANTIC_ERROR (-512)  // (-2 << 8)
 /** Operation failed due to lack of memory */
-#define ZONE_OUT_OF_MEMORY (-3)
+#define ZONE_OUT_OF_MEMORY (-768)  // (-3 << 8)
 /** Bad parameter value */
-#define ZONE_BAD_PARAMETER (-4)
+#define ZONE_BAD_PARAMETER (-1024)  // (-4 << 8)
 /** Error reading zone file */
-#define ZONE_IO_ERROR (-5)
+#define ZONE_READ_ERROR (-1280)  // (-5 << 8)
 /** Control directive or support for record type is not implemented */
-#define ZONE_NOT_IMPLEMENTED (-6)
+#define ZONE_NOT_IMPLEMENTED (-1536)  // (-6 << 8)
 /** Specified file does not exist */
-#define ZONE_NOT_A_FILE (-6)
+#define ZONE_NOT_A_FILE (-1792)  // (-7 << 8)
 /** Access to specified file is not allowed */
-#define ZONE_NOT_PERMITTED (-7)
+#define ZONE_NOT_PERMITTED (-2048)  // (-8 << 8)
 /** @} */
 
 /**

include/zone/attributes.h

@@ -43,27 +43,9 @@
 #define zone_nonnull_all zone_attribute((__nonnull__))
 
 #if _MSC_VER
-# define zone_really_inline __forceinline
-# define zone_never_inline __declspec(noinline)
-# define zone_warn_unused_result
-
-# define zone_likely(params) (params)
-# define zone_unlikely(params) (params)
-
 # define zone_format(params)
 # define zone_format_printf(string_index, first_to_check)
 #else // _MSC_VER
-# define zone_really_inline inline zone_attribute((always_inline))
-# define zone_never_inline zone_attribute((noinline))
-# if zone_has_attribute(warn_unused_result)
-#   define zone_warn_unused_result zone_attribute((warn_unused_result))
-# else
-#   define zone_warn_unused_result
-# endif
-
-# define zone_likely(params) __builtin_expect(!!(params), 1)
-# define zone_unlikely(params) __builtin_expect(!!(params), 0)
-
 # if zone_has_attribute(format)
 #   define zone_format(params) zone_attribute((__format__ params))
 #   if __MINGW32__