1 files changed, 130 insertions, 0 deletions
diff --git a/ntpd/ntp_scanner.h b/ntpd/ntp_scanner.h
new file mode 100644
index 0000000..6797637
--- /dev/null
+++ b/ntpd/ntp_scanner.h
@@ -0,0 +1,130 @@
+/* ntp_scanner.h
+ *
+ * The header file for a simple lexical analyzer. 
+ *
+ * Written By:	Sachin Kamboj
+ *		University of Delaware
+ *		Newark, DE 19711
+ * Copyright (c) 2006
+ */
+
+#ifndef NTP_SCANNER_H
+#define NTP_SCANNER_H
+
+#include "ntp_config.h"
+
+/*
+ * ntp.conf syntax is slightly irregular in that some tokens such as
+ * hostnames do not require quoting even if they might otherwise be
+ * recognized as T_ terminal tokens.  This hand-crafted lexical scanner
+ * uses a "followed by" value associated with each keyword to indicate
+ * normal scanning of the next token, forced scanning of the next token
+ * alone as a T_String, or forced scanning of all tokens to the end of
+ * the command as T_String.
+ * In the past the identifiers for this functionality ended in _ARG:
+ *
+ * NO_ARG	->	FOLLBY_TOKEN
+ * SINGLE_ARG	->	FOLLBY_STRING
+ * MULTIPLE_ARG	->	FOLLBY_STRINGS_TO_EOC
+ *
+ * Note that some tokens use FOLLBY_TOKEN even though they sometimes
+ * are followed by strings.  FOLLBY_STRING is used only when needed to
+ * avoid the keyword scanner matching a token where a string is needed.
+ *
+ * FOLLBY_NON_ACCEPT is an overloading of this field to distinguish
+ * non-accepting states (where the state number does not match a T_
+ * value).
+ */
+typedef enum {
+	FOLLBY_TOKEN = 0,
+	FOLLBY_STRING,
+	FOLLBY_STRINGS_TO_EOC,
+	FOLLBY_NON_ACCEPTING
+} follby;
+
+#define MAXLINE		1024	/* maximum length of line */
+#define MAXINCLUDELEVEL	5	/* maximum include file levels */
+
+/* STRUCTURES
+ * ----------
+ */
+
+/* 
+ * Define a structure to hold the FSA for the keywords.
+ * The structure is actually a trie.
+ *
+ * To save space, a single u_int32 encodes four fields, and a fifth
+ * (the token completed for terminal states) is implied by the index of
+ * the rule within the scan state array, taking advantage of the fact
+ * there are more scan states than the highest T_ token number.
+ *
+ * The lowest 8 bits hold the character the state matches on.
+ * Bits 8 and 9 hold the followedby value (0 - 3).  For non-accepting
+ *   states (which do not match a completed token) the followedby
+ *   value 3 (FOLLBY_NONACCEPTING) denotes that fact.  For accepting
+ *   states, values 0 - 2 control whether the scanner forces the
+ *   following token(s) to strings.
+ * Bits 10 through 20 hold the next state to check not matching
+ * this state's character.
+ * Bits 21 through 31 hold the next state to check matching the char.
+ */
+
+#define S_ST(ch, fb, match_n, other_n) (			\
+	(u_char)((ch) & 0xff) |					\
+	((u_int32)(fb) << 8) |					\
+	((u_int32)(match_n) << 10) |				\
+	((u_int32)(other_n) << 21)				\
+)
+
+#define SS_CH(ss)	((char)(u_char)((ss) & 0xff))
+#define SS_FB(ss)	(((u_int)(ss) >>  8) & 0x3)
+#define SS_MATCH_N(ss)	(((u_int)(ss) >> 10) & 0x7ff)
+#define SS_OTHER_N(ss)	(((u_int)(ss) >> 21) & 0x7ff)
+
+typedef u_int32 scan_state;
+
+
+/* Structure to hold a filename, file pointer and positional info */
+struct FILE_INFO {
+	const char *	fname;			/* Path to the file */
+	FILE *		fd;			/* File Descriptor */
+	int		line_no;		/* Line Number */
+	int		col_no;			/* Column Number */
+	int		prev_line_col_no;	/* Col No on the 
+						   previous line when a
+						   '\n' was seen */
+	int		prev_token_line_no;	/* Line at start of
+						   token */
+	int		prev_token_col_no;	/* Col No at start of
+						   token */
+	int		err_line_no;
+	int		err_col_no;
+};
+
+
+/* SCANNER GLOBAL VARIABLES 
+ * ------------------------
+ */
+extern config_tree cfgt;	  /* Parser output stored here */
+extern int curr_include_level;    /* The current include level */
+
+/* VARIOUS EXTERNAL DECLARATIONS
+ * -----------------------------
+ */
+extern int old_config_style;
+extern int input_from_file;
+extern struct FILE_INFO *fp[];
+
+/* VARIOUS SUBROUTINE DECLARATIONS
+ * -------------------------------
+ */
+extern const char *keyword(int token);
+extern char *quote_if_needed(char *str);
+int yylex(struct FILE_INFO *);
+
+struct FILE_INFO *F_OPEN(const char *path, const char *mode);
+int FGETC(struct FILE_INFO *stream);
+int UNGETC(int ch, struct FILE_INFO *stream);
+int FCLOSE(struct FILE_INFO *stream);
+
+#endif	/* NTP_SCANNER_H */