Unsetting route attributes without messing with type system

This commit is contained in:
Maria Matejka 2022-03-14 11:13:48 +01:00
parent 63cf5d5d8c
commit 0f68515263
5 changed files with 50 additions and 44 deletions

View file

@ -714,9 +714,6 @@
case EAF_TYPE_LC_SET:
RESULT_(T_LCLIST, ad, e->u.ptr);
break;
case EAF_TYPE_UNDEF:
RESULT_VOID;
break;
default:
bug("Unknown dynamic attribute type");
}
@ -794,23 +791,8 @@
ACCESS_RTE;
ACCESS_EATTRS;
{
struct ea_list *l = lp_alloc(fs->pool, sizeof(struct ea_list) + sizeof(eattr));
l->next = NULL;
l->flags = EALF_SORTED;
l->count = 1;
l->attrs[0].id = da.ea_code;
l->attrs[0].flags = 0;
l->attrs[0].type = EAF_TYPE_UNDEF;
l->attrs[0].originated = 1;
l->attrs[0].fresh = 1;
l->attrs[0].u.data = 0;
f_rta_cow(fs);
l->next = *fs->eattrs;
*fs->eattrs = l;
}
f_rta_cow(fs);
ea_unset_attr(fs->eattrs, fs->pool, 1, da.ea_code);
}
INST(FI_LENGTH, 1, 1) { /* Get length of */

View file

@ -505,6 +505,7 @@ typedef struct eattr {
byte type:5; /* Attribute type */
byte originated:1; /* The attribute has originated locally */
byte fresh:1; /* An uncached attribute (e.g. modified in export filter) */
byte undef:1; /* Explicitly undefined */
union {
uintptr_t data;
const struct adata *ptr; /* Attribute data elsewhere */
@ -540,7 +541,6 @@ const char *ea_custom_name(uint ea);
#define EAF_TYPE_PTR 0x0d /* Pointer to an object */
#define EAF_TYPE_EC_SET 0x0e /* Set of pairs of u32's - ext. community list */
#define EAF_TYPE_LC_SET 0x12 /* Set of triplets of u32's - large community list */
#define EAF_TYPE_UNDEF 0x1f /* `force undefined' entry */
#define EAF_EMBEDDED 0x01 /* Data stored in eattr.u.data (part of type spec) */
#define EAF_VAR_LENGTH 0x02 /* Attribute length is variable (part of type spec) */
@ -610,27 +610,50 @@ void ea_format_bitfield(const struct eattr *a, byte *buf, int bufsize, const cha
ea = NULL; \
} while(0) \
struct ea_one_attr_list {
ea_list l;
eattr a;
};
static inline eattr *
ea_set_attr(ea_list **to, struct linpool *pool, uint id, uint flags, uint type, uintptr_t val)
{
ea_list *a = lp_alloc(pool, sizeof(ea_list) + sizeof(eattr));
eattr *e = &a->attrs[0];
struct ea_one_attr_list *ea = lp_alloc(pool, sizeof(*ea));
*ea = (struct ea_one_attr_list) {
.l.flags = EALF_SORTED,
.l.count = 1,
.l.next = *to,
a->flags = EALF_SORTED;
a->count = 1;
a->next = *to;
*to = a;
e->id = id;
e->type = type;
e->flags = flags;
.a.id = id,
.a.type = type,
.a.flags = flags,
};
if (type & EAF_EMBEDDED)
e->u.data = (u32) val;
ea->a.u.data = val;
else
e->u.ptr = (struct adata *) val;
ea->a.u.ptr = (struct adata *) val;
return e;
*to = &ea->l;
return &ea->a;
}
static inline void
ea_unset_attr(ea_list **to, struct linpool *pool, _Bool local, uint code)
{
struct ea_one_attr_list *ea = lp_alloc(pool, sizeof(*ea));
*ea = (struct ea_one_attr_list) {
.l.flags = EALF_SORTED,
.l.count = 1,
.l.next = *to,
.a.id = code,
.a.fresh = local,
.a.originated = local,
.a.undef = 1,
};
*to = &ea->l;
}
static inline void

View file

@ -448,8 +448,7 @@ ea_find(ea_list *e, unsigned id)
{
eattr *a = ea__find(e, id & EA_CODE_MASK);
if (a && (a->type & EAF_TYPE_MASK) == EAF_TYPE_UNDEF &&
!(id & EA_ALLOW_UNDEF))
if (a && a->undef && !(id & EA_ALLOW_UNDEF))
return NULL;
return a;
}
@ -516,7 +515,7 @@ ea_walk(struct ea_walk_state *s, uint id, uint max)
BIT32_SET(s->visited, n);
if ((a->type & EAF_TYPE_MASK) == EAF_TYPE_UNDEF)
if (a->undef)
continue;
s->eattrs = e;
@ -616,7 +615,7 @@ ea_do_prune(ea_list *e)
/* Now s0 is the most recent version, s[-1] the oldest one */
/* Drop undefs */
if ((s0->type & EAF_TYPE_MASK) == EAF_TYPE_UNDEF)
if (s0->undef)
continue;
/* Copy the newest version to destination */
@ -742,6 +741,7 @@ ea_same(ea_list *x, ea_list *y)
a->type != b->type ||
a->originated != b->originated ||
a->fresh != b->fresh ||
a->undef != b->undef ||
((a->type & EAF_EMBEDDED) ? a->u.data != b->u.data : !adata_same(a->u.ptr, b->u.ptr)))
return 0;
}
@ -944,6 +944,10 @@ ea_show(struct cli *c, const eattr *e)
{
*pos++ = ':';
*pos++ = ' ';
if (e->undef)
bsprintf(pos, "undefined");
else
switch (e->type & EAF_TYPE_MASK)
{
case EAF_TYPE_INT:
@ -973,7 +977,6 @@ ea_show(struct cli *c, const eattr *e)
case EAF_TYPE_LC_SET:
ea_show_lc_set(c, ad, pos, buf, end);
return;
case EAF_TYPE_UNDEF:
default:
bsprintf(pos, "<type %02x>", e->type);
}

View file

@ -106,7 +106,7 @@ bgp_set_attr(ea_list **attrs, struct linpool *pool, uint code, uint flags, uintp
({ REPORT(msg, ## args); s->err_withdraw = 1; return; })
#define UNSET(a) \
({ a->type = EAF_TYPE_UNDEF; return; })
({ a->undef = 1; return; })
#define REJECT(msg, args...) \
({ log(L_ERR "%s: " msg, s->proto->p.name, ## args); s->err_reject = 1; return; })
@ -1161,7 +1161,7 @@ bgp_export_attr(struct bgp_export_state *s, eattr *a, ea_list *to)
CALL(desc->export, s, a);
/* Attribute might become undefined in hook */
if ((a->type & EAF_TYPE_MASK) == EAF_TYPE_UNDEF)
if (a->undef)
return;
}
else

View file

@ -563,9 +563,7 @@ bgp_set_attr_data(ea_list **to, struct linpool *pool, uint code, uint flags, voi
bgp_set_attr(to, pool, code, flags, (uintptr_t) a);
}
static inline void
bgp_unset_attr(ea_list **to, struct linpool *pool, uint code)
{ eattr *e = bgp_set_attr(to, pool, code, 0, 0); e->type = EAF_TYPE_UNDEF; }
#define bgp_unset_attr(to, pool, code) ea_unset_attr(to, pool, 0, code)
int bgp_encode_mp_reach_mrt(struct bgp_write_state *s, eattr *a, byte *buf, uint size);