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Add more expression evaluation goo.

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This commit is contained in:
Ted Lemon
1998-11-06 00:14:47 +00:00
parent c4763f5f3f
commit a461fb50b6
1 changed files with 56 additions and 34 deletions
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90
includes/tree.h
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@@ -53,35 +53,54 @@ typedef struct _pair {
#define TREE_LIMIT 4
#define TREE_DATA_EXPR 5
/* A data buffer with a reference count. */
struct buffer {
int refcnt;
char data [1];
};
/* XXX The mechanism by which data strings are returned is currently
XXX broken: rather than returning an ephemeral pointer, we create
XXX a reference to the data in the caller's space, which the caller
XXX then has to dereference - instead, the reference should be
XXX ephemeral by default and be made a persistent reference explicitly. */
/* A string of data bytes, possibly accompanied by a larger buffer. */
struct data_string {
unsigned char *data, *buffer;
struct buffer *buffer;
unsigned char *data;
int len;
int terminated;
};
/* Expression tree structure. */
enum expr_op {
expr_none,
expr_match,
expr_check,
expr_equal,
expr_substring,
expr_suffix,
expr_concat,
expr_host_lookup,
expr_and,
expr_or,
expr_not,
expr_option,
expr_hardware,
expr_packet,
expr_const_data,
expr_extract_int8,
expr_extract_int16,
expr_extract_int32,
expr_const_int,
expr_exists,
};
struct expression {
enum {
expr_check,
expr_equal,
expr_substring,
expr_suffix,
expr_concat,
expr_host_lookup,
expr_and,
expr_or,
expr_not,
expr_option,
expr_hardware,
expr_packet,
expr_const_data,
expr_extract_int8,
expr_extract_int16,
expr_extract_int32,
expr_const_int,
} op;
int refcnt;
enum expr_op op;
union {
struct {
struct expression *expr;
@@ -103,13 +122,11 @@ struct expression {
struct expression *len;
} packet;
struct data_string const_data;
struct {
struct expression *expr;
struct expression *width;
} extract_int;
struct expression *extract_int;
unsigned long const_int;
struct expression *concat [2];
struct dns_host_entry *host_lookup;
struct option *exists;
} data;
int flags;
# define EXPR_EPHEMERAL 1
@@ -117,26 +134,24 @@ struct expression {
/* DNS host entry structure... */
struct dns_host_entry {
char *hostname;
char *buffer;
int buf_len;
int data_len;
int refcnt;
TIME timeout;
struct data_string data;
char hostname [1];
};
struct option_cache {
struct expression *expression;
struct option *option;
};
struct option_cache; /* forward */
struct data_string; /* forward */
struct packet; /* forward */
struct option_state; /* forward */
struct decoded_option_state; /* forward */
enum statement_op; /* forward */
struct universe {
char *name;
struct data_string (*lookup_func) PROTO ((struct packet *, int));
int (*lookup_func)
PROTO ((struct data_string *,
struct option_state *, int));
void (*set_func) PROTO ((struct option_state *,
struct option_cache *,
enum statement_op));
@@ -150,3 +165,10 @@ struct option {
struct universe *universe;
unsigned char code;
};
enum expression_context {
context_any,
context_boolean,
context_data,
context_numeric
};