899 lines
23 KiB
C
899 lines
23 KiB
C
/*
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* Filters: utility functions
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*
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* Copyright 1998 Pavel Machek <pavel@ucw.cz>
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*
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* Can be freely distributed and used under the terms of the GNU GPL.
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*
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*/
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/**
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* DOC: Filters
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*
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* You can find sources of the filter language in |filter/|
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* directory. File |filter/config.Y| contains filter grammar and basically translates
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* the source from user into a tree of &f_inst structures. These trees are
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* later interpreted using code in |filter/filter.c|.
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*
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* A filter is represented by a tree of &f_inst structures, one structure per
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* "instruction". Each &f_inst contains @code, @aux value which is
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* usually the data type this instruction operates on and two generic
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* arguments (@a1, @a2). Some instructions contain pointer(s) to other
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* instructions in their (@a1, @a2) fields.
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*
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* Filters use a &f_val structure for their data. Each &f_val
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* contains type and value (types are constants prefixed with %T_). Few
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* of the types are special; %T_RETURN can be or-ed with a type to indicate
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* that return from a function or from the whole filter should be
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* forced. Important thing about &f_val's is that they may be copied
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* with a simple |=|. That's fine for all currently defined types: strings
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* are read-only (and therefore okay), paths are copied for each
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* operation (okay too).
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*/
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#undef LOCAL_DEBUG
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#include "nest/bird.h"
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#include "lib/lists.h"
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#include "lib/resource.h"
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#include "lib/socket.h"
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#include "lib/string.h"
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#include "lib/unaligned.h"
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#include "nest/route.h"
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#include "nest/protocol.h"
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#include "nest/iface.h"
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#include "nest/attrs.h"
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#include "conf/conf.h"
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#include "filter/filter.h"
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#define P(a,b) ((a<<8) | b)
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#define CMP_ERROR 999
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static struct adata *
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adata_empty(struct linpool *pool)
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{
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struct adata *res = lp_alloc(pool, sizeof(struct adata));
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res->length = 0;
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return res;
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}
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static int
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pm_path_compare(struct f_path_mask *m1, struct f_path_mask *m2)
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{
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while (1) {
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if ((!m1) || (!m2))
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return !((!m1) && (!m2));
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m1 = m1->next;
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m2 = m2->next;
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}
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}
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static void
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pm_format(struct f_path_mask *p, byte *buf, unsigned int size)
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{
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byte *end = buf + size - 16;
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while (p)
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{
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if (buf > end)
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{
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strcpy(buf, " ...");
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return;
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}
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if (p->any)
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buf += bsprintf(buf, "? ");
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else
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buf += bsprintf(buf, "%u ", p->val);
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p = p->next;
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}
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*buf = 0;
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}
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/**
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* val_compare - compare two values
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* @v1: first value
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* @v2: second value
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*
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* Compares two values and returns -1, 0, 1 on <, =, > or 999 on error.
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* Tree module relies on this giving consistent results so that it can
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* build balanced trees.
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*/
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int
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val_compare(struct f_val v1, struct f_val v2)
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{
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int rc;
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if ((v1.type == T_VOID) && (v2.type == T_VOID))
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return 0;
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if (v1.type == T_VOID) /* Hack for else */
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return -1;
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if (v2.type == T_VOID)
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return 1;
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if (v1.type != v2.type) {
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debug( "Types do not match in val_compare\n" );
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return CMP_ERROR;
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}
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switch (v1.type) {
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case T_ENUM:
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case T_INT:
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case T_PAIR:
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if (v1.val.i == v2.val.i) return 0;
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if (v1.val.i < v2.val.i) return -1;
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return 1;
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case T_IP:
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return ipa_compare(v1.val.px.ip, v2.val.px.ip);
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case T_PREFIX:
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if (rc = ipa_compare(v1.val.px.ip, v2.val.px.ip))
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return rc;
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if (v1.val.px.len < v2.val.px.len)
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return -1;
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if (v1.val.px.len > v2.val.px.len)
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return 1;
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return 0;
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case T_PATH_MASK:
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return pm_path_compare(v1.val.path_mask, v2.val.path_mask);
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default:
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debug( "Compare of unkown entities: %x\n", v1.type );
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return CMP_ERROR;
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}
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}
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/*
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* val_simple_in_range - check if @v1 ~ @v2 for everything except sets
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*/
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static int
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val_simple_in_range(struct f_val v1, struct f_val v2)
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{
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if ((v1.type == T_PATH) && (v2.type == T_PATH_MASK))
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return as_path_match(v1.val.ad, v2.val.path_mask);
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if ((v1.type == T_PAIR) && (v2.type == T_CLIST))
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return int_set_contains(v2.val.ad, v1.val.i);
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if ((v1.type == T_IP) && (v2.type == T_PREFIX))
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return !(ipa_compare(ipa_and(v2.val.px.ip, ipa_mkmask(v2.val.px.len)), ipa_and(v1.val.px.ip, ipa_mkmask(v2.val.px.len))));
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if ((v1.type == T_PREFIX) && (v2.type == T_PREFIX)) {
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ip_addr mask;
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if (v1.val.px.len & (LEN_PLUS | LEN_MINUS | LEN_RANGE))
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return CMP_ERROR;
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mask = ipa_mkmask( v2.val.px.len & LEN_MASK );
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if (ipa_compare(ipa_and(v2.val.px.ip, mask), ipa_and(v1.val.px.ip, mask)))
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return 0;
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if ((v2.val.px.len & LEN_MINUS) && (v1.val.px.len <= (v2.val.px.len & LEN_MASK)))
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return 0;
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if ((v2.val.px.len & LEN_PLUS) && (v1.val.px.len < (v2.val.px.len & LEN_MASK)))
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return 0;
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if ((v2.val.px.len & LEN_RANGE) && ((v1.val.px.len < (0xff & (v2.val.px.len >> 16)))
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|| (v1.val.px.len > (0xff & (v2.val.px.len >> 8)))))
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return 0;
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return 1;
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}
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return CMP_ERROR;
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}
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/**
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* val_in_range - implement |~| operator
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* @v1: element
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* @v2: set
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*
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* Checks if @v1 is element (|~| operator) of @v2. Sets are internally represented as balanced trees, see
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* |tree.c| module (this is not limited to sets, but for non-set cases, val_simple_in_range() is called early).
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*/
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static int
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val_in_range(struct f_val v1, struct f_val v2)
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{
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int res;
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res = val_simple_in_range(v1, v2);
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if (res != CMP_ERROR)
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return res;
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if (v2.type == T_SET)
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switch (v1.type) {
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case T_ENUM:
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case T_INT:
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case T_IP:
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case T_PREFIX:
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{
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struct f_tree *n;
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n = find_tree(v2.val.t, v1);
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if (!n)
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return 0;
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return !! (val_simple_in_range(v1, n->from)); /* We turn CMP_ERROR into compared ok, and that's fine */
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}
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}
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return CMP_ERROR;
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}
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static void
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tree_print(struct f_tree *t)
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{
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if (!t) {
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debug( "() " );
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return;
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}
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debug( "[ " );
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tree_print( t->left );
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debug( ", " ); val_print( t->from ); debug( ".." ); val_print( t->to ); debug( ", " );
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tree_print( t->right );
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debug( "] " );
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}
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/*
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* val_print - format filter value
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*/
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void
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val_print(struct f_val v)
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{
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char buf[2048];
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char buf2[1024];
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#define PRINTF(a...) bsnprintf( buf, 2040, a )
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buf[0] = 0;
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switch (v.type) {
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case T_VOID: PRINTF( "(void)" ); break;
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case T_BOOL: PRINTF( v.val.i ? "TRUE" : "FALSE" ); break;
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case T_INT: PRINTF( "%d ", v.val.i ); break;
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case T_STRING: PRINTF( "%s", v.val.s ); break;
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case T_IP: PRINTF( "%I", v.val.px.ip ); break;
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case T_PREFIX: PRINTF( "%I/%d", v.val.px.ip, v.val.px.len ); break;
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case T_PAIR: PRINTF( "(%d,%d)", v.val.i >> 16, v.val.i & 0xffff ); break;
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case T_SET: tree_print( v.val.t ); PRINTF( "\n" ); break;
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case T_ENUM: PRINTF( "(enum %x)%d", v.type, v.val.i ); break;
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case T_PATH: as_path_format(v.val.ad, buf2, 1020); PRINTF( "(path %s)", buf2 ); break;
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case T_CLIST: int_set_format(v.val.ad, 1, buf2, 1020); PRINTF( "(clist %s)", buf2 ); break;
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case T_PATH_MASK: pm_format(v.val.path_mask, buf2, 1020); PRINTF( "(pathmask %s)", buf2 ); break;
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default: PRINTF( "[unknown type %x]", v.type );
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#undef PRINTF
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}
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debug( buf );
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}
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static struct rte **f_rte, *f_rte_old;
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static struct linpool *f_pool;
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static struct ea_list **f_tmp_attrs;
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static int f_flags;
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static rta *f_rta_copy;
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/*
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* rta_cow - prepare rta for modification by filter
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*/
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static void
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rta_cow(void)
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{
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if (!f_rta_copy) {
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f_rta_copy = lp_alloc(f_pool, sizeof(rta));
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memcpy(f_rta_copy, (*f_rte)->attrs, sizeof(rta));
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f_rta_copy->aflags = 0;
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*f_rte = rte_cow(*f_rte);
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rta_free((*f_rte)->attrs);
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(*f_rte)->attrs = f_rta_copy;
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}
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}
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#define runtime(x) do { \
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log( L_ERR "filters, line %d: %s", what->lineno, x); \
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res.type = T_RETURN; \
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res.val.i = F_ERROR; \
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return res; \
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} while(0)
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#define ARG(x,y) \
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x = interpret(what->y); \
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if (x.type & T_RETURN) \
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return x;
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#define ONEARG ARG(v1, a1.p)
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#define TWOARGS ARG(v1, a1.p) \
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ARG(v2, a2.p)
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#define TWOARGS_C TWOARGS \
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if (v1.type != v2.type) \
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runtime( "Can't operate with values of incompatible types" );
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/**
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* interpret
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* @what: filter to interpret
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*
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* Interpret given tree of filter instructions. This is core function
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* of filter system and does all the hard work.
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*
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* Each instruction has 4 fields: code (which is instruction code),
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* aux (which is extension to instruction code, typically type),
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* arg1 and arg2 - arguments. Depending on instruction, arguments
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* are either integers, or pointers to instruction trees. Common
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* instructions like +, that have two expressions as arguments use
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* TWOARGS macro to get both of them evaluated.
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*
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* &f_val structures are copied around, so there are no problems with
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* memory managment.
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*/
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static struct f_val
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interpret(struct f_inst *what)
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{
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struct symbol *sym;
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struct f_val v1, v2, res;
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int i;
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res.type = T_VOID;
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if (!what)
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return res;
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switch(what->code) {
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case ',':
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TWOARGS;
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break;
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/* Binary operators */
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case '+':
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TWOARGS_C;
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switch (res.type = v1.type) {
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case T_VOID: runtime( "Can't operate with values of type void" );
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case T_INT: res.val.i = v1.val.i + v2.val.i; break;
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default: runtime( "Usage of unknown type" );
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}
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break;
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case '-':
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TWOARGS_C;
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switch (res.type = v1.type) {
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case T_VOID: runtime( "Can't operate with values of type void" );
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case T_INT: res.val.i = v1.val.i - v2.val.i; break;
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default: runtime( "Usage of unknown type" );
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}
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break;
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case '*':
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TWOARGS_C;
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switch (res.type = v1.type) {
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case T_VOID: runtime( "Can't operate with values of type void" );
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case T_INT: res.val.i = v1.val.i * v2.val.i; break;
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default: runtime( "Usage of unknown type" );
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}
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break;
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case '/':
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TWOARGS_C;
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switch (res.type = v1.type) {
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case T_VOID: runtime( "Can't operate with values of type void" );
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case T_INT: if (v2.val.i == 0) runtime( "Mother told me not to divide by 0" );
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res.val.i = v1.val.i / v2.val.i; break;
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case T_IP: if (v2.type != T_INT)
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runtime( "Incompatible types in / operator" );
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break;
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default: runtime( "Usage of unknown type" );
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}
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break;
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case '&':
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TWOARGS_C;
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res.type = v1.type;
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if (res.type != T_BOOL) runtime( "Can't do boolean operation on non-booleans" );
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res.val.i = v1.val.i && v2.val.i;
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break;
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case '|':
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TWOARGS_C;
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res.type = v1.type;
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if (res.type != T_BOOL) runtime( "Can't do boolean operation on non-booleans" );
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res.val.i = v1.val.i || v2.val.i;
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break;
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/* Relational operators */
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#define COMPARE(x) \
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TWOARGS_C; \
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res.type = T_BOOL; \
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i = val_compare(v1, v2); \
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if (i==CMP_ERROR) \
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runtime( "Error in comparison" ); \
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res.val.i = (x); \
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break;
|
|
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case P('!','='): COMPARE(i!=0);
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case P('=','='): COMPARE(i==0);
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case '<': COMPARE(i==-1);
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case P('<','='): COMPARE(i!=1);
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|
|
|
case '!':
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ONEARG;
|
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if (v1.type != T_BOOL)
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runtime( "Not applied to non-boolean" );
|
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res = v1;
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res.val.i = !res.val.i;
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break;
|
|
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case '~':
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TWOARGS;
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res.type = T_BOOL;
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res.val.i = val_in_range(v1, v2);
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if (res.val.i == CMP_ERROR)
|
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runtime( "~ applied on unknown type pair" );
|
|
break;
|
|
case P('d','e'):
|
|
ONEARG;
|
|
res.type = T_BOOL;
|
|
res.val.i = (v1.type != T_VOID);
|
|
break;
|
|
|
|
/* Set to indirect value, a1 = variable, a2 = value */
|
|
case 's':
|
|
ARG(v2, a2.p);
|
|
sym = what->a1.p;
|
|
switch (res.type = v2.type) {
|
|
case T_VOID: runtime( "Can't assign void values" );
|
|
case T_ENUM:
|
|
case T_INT:
|
|
case T_IP:
|
|
case T_PREFIX:
|
|
case T_PAIR:
|
|
case T_PATH:
|
|
case T_CLIST:
|
|
case T_PATH_MASK:
|
|
if (sym->class != (SYM_VARIABLE | v2.type))
|
|
runtime( "Assigning to variable of incompatible type" );
|
|
* (struct f_val *) sym->aux2 = v2;
|
|
break;
|
|
default:
|
|
bug( "Set to invalid type" );
|
|
}
|
|
break;
|
|
|
|
case 'c': /* integer (or simple type) constant */
|
|
res.type = what->aux;
|
|
res.val.i = what->a2.i;
|
|
break;
|
|
case 'C':
|
|
res = * ((struct f_val *) what->a1.p);
|
|
break;
|
|
case 'p':
|
|
ONEARG;
|
|
val_print(v1);
|
|
break;
|
|
case '?': /* ? has really strange error value, so we can implement if ... else nicely :-) */
|
|
ONEARG;
|
|
if (v1.type != T_BOOL)
|
|
runtime( "If requires boolean expression" );
|
|
if (v1.val.i) {
|
|
ARG(res,a2.p);
|
|
res.val.i = 0;
|
|
} else res.val.i = 1;
|
|
res.type = T_BOOL;
|
|
break;
|
|
case '0':
|
|
debug( "No operation\n" );
|
|
break;
|
|
case P('p',','):
|
|
ONEARG;
|
|
if (what->a2.i == F_NOP || (what->a2.i != F_NONL && what->a1.p))
|
|
debug( "\n" );
|
|
|
|
switch (what->a2.i) {
|
|
case F_QUITBIRD:
|
|
die( "Filter asked me to die" );
|
|
case F_ACCEPT:
|
|
/* Should take care about turning ACCEPT into MODIFY */
|
|
case F_ERROR:
|
|
case F_REJECT: /* FIXME (noncritical) Should print complete route along with reason to reject route */
|
|
res.type = T_RETURN;
|
|
res.val.i = what->a2.i;
|
|
return res; /* We have to return now, no more processing. */
|
|
case F_NONL:
|
|
case F_NOP:
|
|
break;
|
|
default:
|
|
bug( "unknown return type: Can't happen");
|
|
}
|
|
break;
|
|
case 'a': /* rta access */
|
|
{
|
|
struct rta *rta = (*f_rte)->attrs;
|
|
res.type = what->aux;
|
|
switch(res.type) {
|
|
case T_IP:
|
|
res.val.px.ip = * (ip_addr *) ((char *) rta + what->a2.i);
|
|
break;
|
|
case T_ENUM:
|
|
res.val.i = * ((char *) rta + what->a2.i);
|
|
break;
|
|
case T_PREFIX: /* Warning: this works only for prefix of network */
|
|
{
|
|
res.val.px.ip = (*f_rte)->net->n.prefix;
|
|
res.val.px.len = (*f_rte)->net->n.pxlen;
|
|
break;
|
|
}
|
|
default:
|
|
bug( "Invalid type for rta access (%x)", res.type );
|
|
}
|
|
}
|
|
break;
|
|
case P('a','S'):
|
|
ONEARG;
|
|
if (what->aux != v1.type)
|
|
runtime( "Attempt to set static attribute to incompatible type" );
|
|
rta_cow();
|
|
{
|
|
struct rta *rta = (*f_rte)->attrs;
|
|
switch (what->aux) {
|
|
case T_ENUM:
|
|
* ((char *) rta + what->a2.i) = v1.val.i;
|
|
break;
|
|
case T_IP:
|
|
* (ip_addr *) ((char *) rta + what->a2.i) = v1.val.px.ip;
|
|
break;
|
|
default:
|
|
bug( "Unknown type in set of static attribute" );
|
|
}
|
|
}
|
|
break;
|
|
case P('e','a'): /* Access to extended attributes */
|
|
{
|
|
eattr *e = NULL;
|
|
if (!(f_flags & FF_FORCE_TMPATTR))
|
|
e = ea_find( (*f_rte)->attrs->eattrs, what->a2.i );
|
|
if (!e)
|
|
e = ea_find( (*f_tmp_attrs), what->a2.i );
|
|
if ((!e) && (f_flags & FF_FORCE_TMPATTR))
|
|
e = ea_find( (*f_rte)->attrs->eattrs, what->a2.i );
|
|
|
|
switch (what->aux & EAF_TYPE_MASK) {
|
|
case EAF_TYPE_INT:
|
|
if (!e) {
|
|
res.type = T_VOID;
|
|
break;
|
|
}
|
|
res.type = T_INT;
|
|
res.val.i = e->u.data;
|
|
break;
|
|
case EAF_TYPE_AS_PATH:
|
|
if (!e) {
|
|
res.type = T_VOID;
|
|
break;
|
|
}
|
|
res.type = T_PATH;
|
|
res.val.ad = e->u.ptr;
|
|
break;
|
|
case EAF_TYPE_INT_SET:
|
|
if (!e) {
|
|
res.type = T_CLIST;
|
|
res.val.ad = adata_empty(f_pool);
|
|
break;
|
|
}
|
|
res.type = T_CLIST;
|
|
res.val.ad = e->u.ptr;
|
|
break;
|
|
default:
|
|
bug("Unknown type in e,a");
|
|
}
|
|
}
|
|
break;
|
|
case P('e','S'):
|
|
ONEARG;
|
|
{
|
|
struct ea_list *l = lp_alloc(f_pool, sizeof(struct ea_list) + sizeof(eattr));
|
|
|
|
l->next = NULL;
|
|
l->flags = EALF_SORTED;
|
|
l->count = 1;
|
|
l->attrs[0].id = what->a2.i;
|
|
l->attrs[0].flags = 0;
|
|
l->attrs[0].type = what->aux | EAF_ORIGINATED;
|
|
switch (what->aux & EAF_TYPE_MASK) {
|
|
case EAF_TYPE_INT:
|
|
if (v1.type != T_INT)
|
|
runtime( "Setting int attribute to non-int value" );
|
|
l->attrs[0].u.data = v1.val.i;
|
|
break;
|
|
case EAF_TYPE_AS_PATH:
|
|
if (v1.type != T_PATH)
|
|
runtime( "Setting path attribute to non-path value" );
|
|
l->attrs[0].u.ptr = v1.val.ad;
|
|
break;
|
|
case EAF_TYPE_INT_SET:
|
|
if (v1.type != T_CLIST)
|
|
runtime( "Setting int set attribute to non-clist value" );
|
|
l->attrs[0].u.ptr = v1.val.ad;
|
|
break;
|
|
case EAF_TYPE_UNDEF:
|
|
if (v1.type != T_VOID)
|
|
runtime( "Setting void attribute to non-void value" );
|
|
l->attrs[0].u.data = 0;
|
|
break;
|
|
default: bug("Unknown type in e,S");
|
|
}
|
|
|
|
if (!(what->aux & EAF_TEMP) && (!(f_flags & FF_FORCE_TMPATTR))) {
|
|
rta_cow();
|
|
l->next = f_rta_copy->eattrs;
|
|
f_rta_copy->eattrs = l;
|
|
} else {
|
|
l->next = (*f_tmp_attrs);
|
|
(*f_tmp_attrs) = l;
|
|
}
|
|
}
|
|
break;
|
|
case 'P':
|
|
res.type = T_INT;
|
|
res.val.i = (*f_rte)->pref;
|
|
break;
|
|
case P('P','S'):
|
|
ONEARG;
|
|
if (v1.type != T_INT)
|
|
runtime( "Can't set preference to non-integer" );
|
|
*f_rte = rte_cow(*f_rte);
|
|
(*f_rte)->pref = v1.val.i;
|
|
break;
|
|
case 'L': /* Get length of */
|
|
ONEARG;
|
|
res.type = T_INT;
|
|
switch(v1.type) {
|
|
case T_PREFIX: res.val.i = v1.val.px.len; break;
|
|
case T_PATH: res.val.i = as_path_getlen(v1.val.ad); break;
|
|
default: bug( "Length of what?" );
|
|
}
|
|
break;
|
|
case P('c','p'): /* Convert prefix to ... */
|
|
ONEARG;
|
|
if (v1.type != T_PREFIX)
|
|
runtime( "Prefix expected" );
|
|
res.type = what->aux;
|
|
switch(res.type) {
|
|
/* case T_INT: res.val.i = v1.val.px.len; break; Not needed any more */
|
|
case T_IP: res.val.px.ip = v1.val.px.ip; break;
|
|
default: bug( "Unknown prefix to conversion" );
|
|
}
|
|
break;
|
|
case 'r':
|
|
ONEARG;
|
|
res = v1;
|
|
res.type |= T_RETURN;
|
|
break;
|
|
case P('c','a'): /* CALL: this is special: if T_RETURN and returning some value, mask it out */
|
|
ONEARG;
|
|
res = interpret(what->a2.p);
|
|
if (res.type == T_RETURN)
|
|
return res;
|
|
res.type &= ~T_RETURN;
|
|
break;
|
|
case P('S','W'):
|
|
ONEARG;
|
|
{
|
|
struct f_tree *t = find_tree(what->a2.p, v1);
|
|
if (!t) {
|
|
v1.type = T_VOID;
|
|
t = find_tree(what->a2.p, v1);
|
|
if (!t) {
|
|
debug( "No else statement?\n");
|
|
break;
|
|
}
|
|
}
|
|
/* It is actually possible to have t->data NULL */
|
|
return interpret(t->data);
|
|
}
|
|
break;
|
|
case P('i','M'): /* IP.MASK(val) */
|
|
TWOARGS;
|
|
if (v2.type != T_INT)
|
|
runtime( "Integer expected");
|
|
if (v1.type != T_IP)
|
|
runtime( "You can mask only IP addresses" );
|
|
{
|
|
ip_addr mask = ipa_mkmask(v2.val.i);
|
|
res.type = T_IP;
|
|
res.val.px.ip = ipa_and(mask, v1.val.px.ip);
|
|
}
|
|
break;
|
|
|
|
case 'E': /* Create empty attribute */
|
|
res.type = what->aux;
|
|
res.val.ad = adata_empty(f_pool);
|
|
break;
|
|
case P('A','p'): /* Path prepend */
|
|
TWOARGS;
|
|
if (v1.type != T_PATH)
|
|
runtime("Can't prepend to non-path");
|
|
if (v2.type != T_INT)
|
|
runtime("Can't prepend non-integer");
|
|
|
|
res.type = T_PATH;
|
|
res.val.ad = as_path_prepend(f_pool, v1.val.ad, v2.val.i);
|
|
break;
|
|
|
|
case P('C','a'): /* Community list add or delete */
|
|
TWOARGS;
|
|
if (v1.type != T_CLIST)
|
|
runtime("Can't add/delete to non-clist");
|
|
if (v2.type != T_PAIR)
|
|
runtime("Can't add/delete non-pair");
|
|
|
|
res.type = T_CLIST;
|
|
switch (what->aux) {
|
|
case 'a': res.val.ad = int_set_add(f_pool, v1.val.ad, v2.val.i); break;
|
|
case 'd': res.val.ad = int_set_del(f_pool, v1.val.ad, v2.val.i); break;
|
|
default: bug("unknown Ca operation");
|
|
}
|
|
break;
|
|
|
|
default:
|
|
bug( "Unknown instruction %d (%c)", what->code, what->code & 0xff);
|
|
}
|
|
if (what->next)
|
|
return interpret(what->next);
|
|
return res;
|
|
}
|
|
|
|
#undef ARG
|
|
#define ARG(x,y) \
|
|
if (!i_same(f1->y, f2->y)) \
|
|
return 0;
|
|
|
|
#define ONEARG ARG(v1, a1.p)
|
|
#define TWOARGS ARG(v1, a1.p) \
|
|
ARG(v2, a2.p)
|
|
|
|
#define A2_SAME if (f1->a2.i != f2->a2.i) return 0;
|
|
|
|
/*
|
|
* i_same - function that does real comparing of instruction trees, you should call filter_same from outside
|
|
*/
|
|
int
|
|
i_same(struct f_inst *f1, struct f_inst *f2)
|
|
{
|
|
if ((!!f1) != (!!f2))
|
|
return 0;
|
|
if (!f1)
|
|
return 1;
|
|
if (f1->aux != f2->aux)
|
|
return 0;
|
|
if (f1->code != f2->code)
|
|
return 0;
|
|
if (f1 == f2) /* It looks strange, but it is possible with call rewriting trickery */
|
|
return 1;
|
|
|
|
switch(f1->code) {
|
|
case ',': /* fall through */
|
|
case '+':
|
|
case '-':
|
|
case '*':
|
|
case '/':
|
|
case '|':
|
|
case '&':
|
|
case P('!','='):
|
|
case P('=','='):
|
|
case '<':
|
|
case P('<','='): TWOARGS; break;
|
|
|
|
case '!': ONEARG; break;
|
|
case '~': TWOARGS; break;
|
|
case P('d','e'): ONEARG; break;
|
|
|
|
case 's':
|
|
ARG(v2, a2.p);
|
|
{
|
|
struct symbol *s1, *s2;
|
|
s1 = f1->a1.p;
|
|
s2 = f2->a1.p;
|
|
if (strcmp(s1->name, s2->name))
|
|
return 0;
|
|
if (s1->class != s2->class)
|
|
return 0;
|
|
}
|
|
break;
|
|
|
|
case 'c':
|
|
if (f1->aux & T_SET) {
|
|
if (!same_tree(f1->a2.p, f2->a2.p))
|
|
return 0;
|
|
break;
|
|
}
|
|
switch (f1->aux) {
|
|
case T_STRING:
|
|
if (strcmp(f1->a2.p, f2->a2.p))
|
|
return 0;
|
|
break;
|
|
default:
|
|
A2_SAME;
|
|
}
|
|
break;
|
|
case 'C':
|
|
if (val_compare(* (struct f_val *) f1->a1.p, * (struct f_val *) f2->a1.p))
|
|
return 0;
|
|
break;
|
|
case 'p': case 'L': ONEARG; break;
|
|
case '?': TWOARGS; break;
|
|
case '0': case 'E': break;
|
|
case P('p',','): ONEARG; A2_SAME; break;
|
|
case 'P':
|
|
case 'a': A2_SAME; break;
|
|
case P('e','a'): A2_SAME; break;
|
|
case P('P','S'):
|
|
case P('a','S'):
|
|
case P('e','S'): ONEARG; A2_SAME; break;
|
|
|
|
case 'r': ONEARG; break;
|
|
case P('c','p'): ONEARG; break;
|
|
case P('c','a'): /* Call rewriting trickery to avoid exponential behaviour */
|
|
ONEARG;
|
|
if (!i_same(f1->a2.p, f2->a2.p))
|
|
return 0;
|
|
f2->a2.p = f1->a2.p;
|
|
break;
|
|
case P('S','W'): ONEARG; if (!same_tree(f1->a2.p, f2->a2.p)) return 0; break;
|
|
case P('i','M'): TWOARGS; break;
|
|
case P('A','p'): TWOARGS; break;
|
|
case P('C','a'): TWOARGS; break;
|
|
default:
|
|
bug( "Unknown instruction %d in same (%c)", f1->code, f1->code & 0xff);
|
|
}
|
|
return i_same(f1->next, f2->next);
|
|
}
|
|
|
|
/**
|
|
* f_run - external entry point to filters
|
|
* @filter: pointer to filter to run
|
|
* @tmp_attrs: where to store newly generated temporary attributes
|
|
* @rte: pointer to pointer to &rte being filtered. When route is modified, this is changed with rte_cow().
|
|
* @tmp_pool: all filter allocations go from this pool
|
|
* @flags: flags
|
|
*/
|
|
int
|
|
f_run(struct filter *filter, struct rte **rte, struct ea_list **tmp_attrs, struct linpool *tmp_pool, int flags)
|
|
{
|
|
struct f_inst *inst;
|
|
struct f_val res;
|
|
DBG( "Running filter `%s'...", filter->name );
|
|
|
|
f_flags = flags;
|
|
f_tmp_attrs = tmp_attrs;
|
|
f_rte = rte;
|
|
f_rte_old = *rte;
|
|
f_rta_copy = NULL;
|
|
f_pool = tmp_pool;
|
|
inst = filter->root;
|
|
res = interpret(inst);
|
|
if (res.type != T_RETURN) {
|
|
log( L_ERR "Filter %s did not return accept nor reject. Make up your mind", filter->name);
|
|
return F_ERROR;
|
|
}
|
|
DBG( "done (%d)\n", res.val.i );
|
|
return res.val.i;
|
|
}
|
|
|
|
int
|
|
f_eval_int(struct f_inst *expr)
|
|
{
|
|
struct f_val res;
|
|
|
|
f_flags = 0;
|
|
f_tmp_attrs = NULL;
|
|
f_rte = NULL;
|
|
f_rte_old = NULL;
|
|
f_rta_copy = NULL;
|
|
f_pool = cfg_mem;
|
|
res = interpret(expr);
|
|
if (res.type != T_INT)
|
|
cf_error("Integer expression expected");
|
|
return res.val.i;
|
|
}
|
|
|
|
/**
|
|
* filter_same - compare two filters
|
|
* @new: first filter to be compared
|
|
* @old: second filter to be compared, notice that this filter is
|
|
* damaged while comparing.
|
|
*
|
|
* Returns 1 in case filters are same, otherwise 0. If there are
|
|
* underlying bugs, it will rather say 0 on same filters than say
|
|
* 1 on different.
|
|
*/
|
|
int
|
|
filter_same(struct filter *new, struct filter *old)
|
|
{
|
|
if (old == new) /* Handle FILTER_ACCEPT and FILTER_REJECT */
|
|
return 1;
|
|
if (old == FILTER_ACCEPT || old == FILTER_REJECT ||
|
|
new == FILTER_ACCEPT || new == FILTER_REJECT)
|
|
return 0;
|
|
return i_same(new->root, old->root);
|
|
}
|