Adding upstream version 2.4.1.upstream/2.4.1upstream

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

1 files changed, 417 insertions, 0 deletions

diff --git a/src/bin/dhcp4/parser_context.h b/src/bin/dhcp4/parser_context.h
new file mode 100644
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+++ b/src/bin/dhcp4/parser_context.h
@@ -0,0 +1,417 @@
+// Copyright (C) 2015-2021 Internet Systems Consortium, Inc. ("ISC")
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+#ifndef PARSER_CONTEXT_H
+#define PARSER_CONTEXT_H
+#include <string>
+#include <map>
+#include <vector>
+#include <dhcp4/dhcp4_parser.h>
+#include <dhcp4/parser_context_decl.h>
+#include <exceptions/exceptions.h>
+
+// Tell Flex the lexer's prototype ...
+#define YY_DECL isc::dhcp::Dhcp4Parser::symbol_type parser4_lex (Parser4Context& driver)
+
+// ... and declare it for the parser's sake.
+YY_DECL;
+
+namespace isc {
+namespace dhcp {
+
+/// @brief Evaluation error exception raised when trying to parse.
+///
+/// @todo: This probably should be common for Dhcp4 and Dhcp6.
+class Dhcp4ParseError : public isc::Exception {
+public:
+    Dhcp4ParseError(const char* file, size_t line, const char* what) :
+        isc::Exception(file, line, what) { };
+};
+
+/// @brief Evaluation context, an interface to the expression evaluation.
+class Parser4Context
+{
+public:
+
+    /// @brief Defines currently supported scopes
+    ///
+    /// Dhcp4Parser is able to parse several types of scope. Usually,
+    /// when it parses a config file, it expects the data to have a map
+    /// with Dhcp4 in it and all the parameters within that Dhcp4 map.
+    /// However, sometimes the parser is expected to parse only a subset
+    /// of that information. For example, it may be asked to parse
+    /// a structure that is host-reservation only, without the global
+    /// 'Dhcp4' or 'reservations' around it. In such case the parser
+    /// is being told to start parsing as PARSER_HOST_RESERVATION4.
+    typedef enum {
+        /// This parser will parse the content as generic JSON.
+        PARSER_JSON,
+
+        /// This parser will parse the content as Dhcp4 config wrapped in a map
+        /// (that's the regular config file)
+        PARSER_DHCP4,
+
+        /// This parser will parse the content of Dhcp4 (without outer { } and
+        /// without "Dhcp4"). It is mostly used in unit-tests as most of the
+        /// unit-tests do not define the outer map and Dhcp4 entity, just the
+        /// contents of it.
+        SUBPARSER_DHCP4,
+
+        /// This will parse the input as interfaces content.
+        PARSER_INTERFACES,
+
+        /// This will parse the input as Subnet4 content.
+        PARSER_SUBNET4,
+
+        /// This will parse the input as pool4 content.
+        PARSER_POOL4,
+
+        /// This will parse the input as host-reservation.
+        PARSER_HOST_RESERVATION,
+
+        /// This will parse the input option definitions (for tests).
+        PARSER_OPTION_DEFS,
+
+        /// This will parse the input as option definition.
+        PARSER_OPTION_DEF,
+
+        /// This will parse the input as option data.
+        PARSER_OPTION_DATA,
+
+        /// This will parse the input as hooks-library.
+        PARSER_HOOKS_LIBRARY,
+
+        /// This will parse the input as dhcp-ddns.
+        PARSER_DHCP_DDNS,
+
+        /// This will parse the input as config-control.
+        PARSER_CONFIG_CONTROL,
+    } ParserType;
+
+    /// @brief Default constructor.
+    Parser4Context();
+
+    /// @brief destructor
+    virtual ~Parser4Context();
+
+    /// @brief JSON elements being parsed.
+    std::vector<isc::data::ElementPtr> stack_;
+
+    /// @brief Method called before scanning starts on a string.
+    ///
+    /// @param str string to be parsed
+    /// @param type specifies expected content
+    void scanStringBegin(const std::string& str, ParserType type);
+
+    /// @brief Method called before scanning starts on a file.
+    ///
+    /// @param f stdio FILE pointer
+    /// @param filename file to be parsed
+    /// @param type specifies expected content
+    void scanFileBegin(FILE* f, const std::string& filename, ParserType type);
+
+    /// @brief Method called after the last tokens are scanned.
+    void scanEnd();
+
+    /// @brief Divert input to an include file.
+    ///
+    /// @param filename file to be included
+    void includeFile(const std::string& filename);
+
+    /// @brief Run the parser on the string specified.
+    ///
+    /// This method parses specified string. Depending on the value of
+    /// parser_type, parser may either check only that the input is valid
+    /// JSON, or may do more specific syntax checking. See @ref ParserType
+    /// for supported syntax checkers.
+    ///
+    /// @param str string to be parsed
+    /// @param parser_type specifies expected content (usually DHCP4 or generic JSON)
+    /// @return Element structure representing parsed text.
+    isc::data::ElementPtr parseString(const std::string& str,
+                                      ParserType parser_type);
+
+    /// @brief Run the parser on the file specified.
+    ///
+    /// This method parses specified file. Depending on the value of
+    /// parser_type, parser may either check only that the input is valid
+    /// JSON, or may do more specific syntax checking. See @ref ParserType
+    /// for supported syntax checkers.
+    ///
+    /// @param filename file to be parsed
+    /// @param parser_type specifies expected content (usually DHCP4 or generic JSON)
+    /// @return Element structure representing parsed text.
+    isc::data::ElementPtr parseFile(const std::string& filename,
+                                    ParserType parser_type);
+
+    /// @brief Error handler
+    ///
+    /// @note The optional position for an error in a string begins by 1
+    /// so the caller should add 1 to the position of the C++ string.
+    ///
+    /// @param loc location within the parsed file where the problem was experienced.
+    /// @param what string explaining the nature of the error.
+    /// @param pos optional position for in string errors.
+    /// @throw Dhcp4ParseError
+    void error(const isc::dhcp::location& loc,
+               const std::string& what,
+               size_t pos = 0);
+
+    /// @brief Error handler
+    ///
+    /// This is a simplified error reporting tool for possible future
+    /// cases when the Dhcp4Parser is not able to handle the packet.
+    ///
+    /// @param what string explaining the nature of the error.
+    /// @throw Dhcp4ParseError
+    void error(const std::string& what);
+
+    /// @brief Fatal error handler
+    ///
+    /// This is for should not happen but fatal errors.
+    /// Used by YY_FATAL_ERROR macro so required to be static.
+    ///
+    /// @param what string explaining the nature of the error.
+    /// @throw Dhcp4ParseError
+    static void fatal(const std::string& what);
+
+    /// @brief Converts bison's position to one understandable by isc::data::Element
+    ///
+    /// Convert a bison location into an element position
+    /// (take the begin, the end is lost)
+    ///
+    /// @param loc location in bison format
+    /// @return Position in format accepted by Element
+    isc::data::Element::Position loc2pos(isc::dhcp::location& loc);
+
+    /// @brief Check if a required parameter is present
+    ///
+    /// Check if a required parameter is present in the map at the top
+    /// of the stack and raise an error when it is not.
+    ///
+    /// @param name name of the parameter to check
+    /// @param open_loc location of the opening curly bracket
+    /// @param close_loc location of the closing curly bracket
+    /// @throw Dhcp4ParseError
+    void require(const std::string& name,
+                 isc::data::Element::Position open_loc,
+                 isc::data::Element::Position close_loc);
+
+    /// @brief Check if a parameter is already present
+    ///
+    /// Check if a parameter is already present in the map at the top
+    /// of the stack and raise an error when it is.
+    ///
+    /// @param name name of the parameter to check
+    /// @param loc location of the current parameter
+    /// @throw Dhcp4ParseError
+    void unique(const std::string& name,
+                isc::data::Element::Position loc);
+
+    /// @brief Warning handler
+    ///
+    /// @param loc location within the parsed file where the problem was experienced
+    /// @param what string explaining the nature of the error
+    ///
+    /// @throw ParseError
+    void warning(const isc::dhcp::location& loc, const std::string& what);
+
+    /// @brief Warning for extra commas
+    ///
+    /// @param loc location within the parsed file of the extra comma
+    ///
+    /// @throw ParseError
+    void warnAboutExtraCommas(const isc::dhcp::location& loc);
+
+    /// @brief Defines syntactic contexts for lexical tie-ins
+    typedef enum {
+        ///< This one is used in pure JSON mode.
+        NO_KEYWORD,
+
+        ///< Used while parsing top level (that contains Dhcp4)
+        CONFIG,
+
+        ///< Used while parsing content of Dhcp4.
+        DHCP4,
+
+        /// Used while parsing Dhcp4/interfaces structures.
+        INTERFACES_CONFIG,
+
+        /// Sanity checks.
+        SANITY_CHECKS,
+
+        /// Used while parsing Dhcp4/interfaces/dhcp-socket-type structures.
+        DHCP_SOCKET_TYPE,
+
+        /// Used while parsing Dhcp4/interfaces/outbound-interface structures.
+        OUTBOUND_INTERFACE,
+
+        /// Used while parsing Dhcp4/lease-database structures.
+        LEASE_DATABASE,
+
+        /// Used while parsing Dhcp4/hosts-database[s] structures.
+        HOSTS_DATABASE,
+
+        /// Used while parsing Dhcp4/*-database/type.
+        DATABASE_TYPE,
+
+        /// Used while parsing Dhcp4/*-database/on-fail.
+        DATABASE_ON_FAIL,
+
+        /// Used while parsing Dhcp4/host-reservation-identifiers.
+        HOST_RESERVATION_IDENTIFIERS,
+
+        /// Used while parsing Dhcp4/hooks-libraries.
+        HOOKS_LIBRARIES,
+
+        /// Used while parsing Dhcp4/Subnet4 structures.
+        SUBNET4,
+
+        /// Used while parsing shared-networks structures.
+        SHARED_NETWORK,
+
+        /// Used while parsing Dhcp4/reservation-mode.
+        RESERVATION_MODE,
+
+        /// Used while parsing Dhcp4/option-def structures.
+        OPTION_DEF,
+
+        /// Used while parsing Dhcp4/option-data, Dhcp4/subnet4/option-data
+        /// or anywhere option-data is present (client classes, host
+        /// reservations and possibly others).
+        OPTION_DATA,
+
+        /// Used while parsing Dhcp4/client-classes structures.
+        CLIENT_CLASSES,
+
+        /// Used while parsing Dhcp4/expired-leases-processing.
+        EXPIRED_LEASES_PROCESSING,
+
+        /// Used while parsing Dhcp4/server-id structures.
+        SERVER_ID,
+
+        /// Used while parsing Dhcp4/control-socket structures.
+        CONTROL_SOCKET,
+
+        /// Used while parsing Dhcp4/dhcp-queue-control structures.
+        DHCP_QUEUE_CONTROL,
+
+        /// Used while parsing Dhcp4/multi-threading structures.
+        DHCP_MULTI_THREADING,
+
+        /// Used while parsing Dhcp4/subnet4/pools structures.
+        POOLS,
+
+        /// Used while parsing Dhcp4/reservations structures.
+        RESERVATIONS,
+
+        /// Used while parsing Dhcp4/subnet4relay structures.
+        RELAY,
+
+        /// Used while parsing Dhcp4/loggers structures.
+        LOGGERS,
+
+        /// Used while parsing Dhcp4/loggers/output_options structures.
+        OUTPUT_OPTIONS,
+
+        /// Used while parsing Dhcp4/dhcp-ddns.
+        DHCP_DDNS,
+
+        /// Used while parsing Dhcp4/dhcp-ddns/ncr-protocol
+        NCR_PROTOCOL,
+
+        /// Used while parsing Dhcp4/dhcp-ddns/ncr-format
+        NCR_FORMAT,
+
+        /// Used while parsing Dhcp4/dhcp-ddns/replace-client-name.
+        REPLACE_CLIENT_NAME,
+
+        /// Used while parsing Dhcp4/config-control
+        CONFIG_CONTROL,
+
+        /// Used while parsing config-control/config-databases
+        CONFIG_DATABASE,
+
+        /// Used while parsing compatibility parameters
+        COMPATIBILITY,
+
+    } ParserContext;
+
+    /// @brief File name
+    std::string file_;
+
+    /// @brief File name stack
+    std::vector<std::string> files_;
+
+    /// @brief Location of the current token
+    ///
+    /// The lexer will keep updating it. This variable will be useful
+    /// for logging errors.
+    isc::dhcp::location loc_;
+
+    /// @brief Location stack
+    std::vector<isc::dhcp::location> locs_;
+
+    /// @brief Lexer state stack
+    std::vector<struct yy_buffer_state*> states_;
+
+    /// @brief sFile (aka FILE)
+    FILE* sfile_;
+
+    /// @brief sFile (aka FILE) stack
+    ///
+    /// This is a stack of files. Typically there's only one file (the
+    /// one being currently parsed), but there may be more if one
+    /// file includes another.
+    std::vector<FILE*> sfiles_;
+
+    /// @brief Current syntactic context
+    ParserContext ctx_;
+
+    /// @brief Enter a new syntactic context
+    ///
+    /// Entering a new syntactic context is useful in several ways.
+    /// First, it allows the parser to avoid conflicts. Second, it
+    /// allows the lexer to return different tokens depending on
+    /// context (e.g. if "renew-timer" string is detected, the lexer
+    /// will return STRING token if in JSON mode or RENEW_TIMER if
+    /// in DHCP4 mode. Finally, the syntactic context allows the
+    /// error message to be more descriptive if the input string
+    /// does not parse properly.
+    ///
+    /// @param ctx the syntactic context to enter into
+    void enter(const ParserContext& ctx);
+
+    /// @brief Leave a syntactic context
+    ///
+    /// @throw isc::Unexpected if unbalanced
+    void leave();
+
+    /// @brief Get the syntactic context name
+    ///
+    /// @return printable name of the context.
+    const std::string contextName();
+
+ private:
+    /// @brief Flag determining scanner debugging.
+    bool trace_scanning_;
+
+    /// @brief Flag determining parser debugging.
+    bool trace_parsing_;
+
+    /// @brief Syntactic context stack
+    std::vector<ParserContext> cstack_;
+
+    /// @brief Common part of parseXXX
+    ///
+    /// @return Element structure representing parsed text.
+    isc::data::ElementPtr parseCommon();
+};
+
+}; // end of isc::eval namespace
+}; // end of isc namespace
+
+#endif