diff options
| -rw-r--r-- | doc/bird.sgml | 4 | ||||
| -rw-r--r-- | filter/filter.c | 28 |
2 files changed, 25 insertions, 7 deletions
diff --git a/doc/bird.sgml b/doc/bird.sgml index c725081a..3a2607b4 100644 --- a/doc/bird.sgml +++ b/doc/bird.sgml @@ -1498,8 +1498,8 @@ if 1234 = i then printn "."; else { like it accesses variables. Attempts to access undefined attribute result in a runtime error; you can check if an attribute is defined by using the <cf>defined( <m>attribute</m> )</cf> operator. One notable exception to this -rule are attributes of clist type, where undefined value is regarded as empty -clist for most purposes. +rule are attributes of bgppath and *clist types, where undefined value is +regarded as empty bgppath/*clist for most purposes. <descrip> <tag><label id="rta-net"><m/prefix/ net</tag> diff --git a/filter/filter.c b/filter/filter.c index aef4f44a..4e17f974 100644 --- a/filter/filter.c +++ b/filter/filter.c @@ -54,6 +54,17 @@ void (*bt_assert_hook)(int result, struct f_inst *assert); +static struct adata undef_adata; /* adata of length 0 used for undefined */ + +/* Special undef value for paths and clists */ +static inline int +undef_value(struct f_val v) +{ + return ((v.type == T_PATH) || (v.type == T_CLIST) || + (v.type == T_ECLIST) || (v.type == T_LCLIST)) && + (v.val.ad == &undef_adata); +} + static struct adata * adata_empty(struct linpool *pool, int l) { @@ -815,7 +826,7 @@ interpret(struct f_inst *what) case P('d','e'): ONEARG; res.type = T_BOOL; - res.val.i = (v1.type != T_VOID); + res.val.i = (v1.type != T_VOID) && !undef_value(v1); break; case 'T': ONEARG; @@ -1001,24 +1012,31 @@ interpret(struct f_inst *what) e = ea_find((*f_rte)->attrs->eattrs, code); if (!e) { - /* A special case: undefined int_set looks like empty int_set */ + /* A special case: undefined as_path looks like empty as_path */ + if ((what->aux & EAF_TYPE_MASK) == EAF_TYPE_AS_PATH) { + res.type = T_PATH; + res.val.ad = &undef_adata; + break; + } + + /* The same special case for int_set */ if ((what->aux & EAF_TYPE_MASK) == EAF_TYPE_INT_SET) { res.type = T_CLIST; - res.val.ad = adata_empty(f_pool, 0); + res.val.ad = &undef_adata; break; } /* The same special case for ec_set */ if ((what->aux & EAF_TYPE_MASK) == EAF_TYPE_EC_SET) { res.type = T_ECLIST; - res.val.ad = adata_empty(f_pool, 0); + res.val.ad = &undef_adata; break; } /* The same special case for lc_set */ if ((what->aux & EAF_TYPE_MASK) == EAF_TYPE_LC_SET) { res.type = T_LCLIST; - res.val.ad = adata_empty(f_pool, 0); + res.val.ad = &undef_adata; break; } |