Filter: Allow manually setting MPLS label

Heh

4 files changed, 34 insertions, 0 deletions

diff --git a/filter/config.Y b/filter/config.Y
index 557a951f..e8860675 100644
--- a/filter/config.Y
+++ b/filter/config.Y
@@ -288,6 +288,7 @@ CF_KEYWORDS(FUNCTION, PRINT, PRINTN, UNSET, RETURN,
 	PREPEND, FIRST, LAST, LAST_NONAGGREGATED, MATCH,
 	EMPTY,
 	FILTER, WHERE, EVAL, ATTRIBUTE,
+	ATTACH_MLS,
 	BT_ASSERT, BT_TEST_SUITE, BT_CHECK_ASSIGN, BT_TEST_SAME, FORMAT)
 
 %nonassoc THEN
@@ -905,6 +906,10 @@ cmd:
  | dynamic_attr '.' FILTER '(' term ')' ';'    { $$ = f_generate_complex( FI_CLIST_FILTER, $1, $5 ); }
  | BT_ASSERT '(' get_cf_position term get_cf_position ')' ';' { $$ = assert_done($4, $3 + 1, $5 - 1); }
  | BT_CHECK_ASSIGN '(' get_cf_position lvalue get_cf_position ',' term ')' ';' { $$ = assert_assign(&$4, $7, $3 + 1, $5 - 1); }
+ | ATTACH_MLS '(' label_stack ')' ';' { $$ = f_new_inst(FI_ATTACH_MLS,
+	f_new_inst(FI_CONSTANT, (struct f_val) { .type = T_MLS, .val.mls = $3, })); }
+ | ATTACH_MLS '(' ')' ';' { $$ = f_new_inst(FI_ATTACH_MLS,
+	f_new_inst(FI_CONSTANT, (struct f_val) { .type = T_MLS, .val.mls = cfg_allocz(sizeof(mpls_label_stack)), })); }
  ;
 
 get_cf_position:
diff --git a/filter/data.c b/filter/data.c
index 40220255..23b0cd27 100644
--- a/filter/data.c
+++ b/filter/data.c
@@ -238,6 +238,14 @@ pm_same(const struct f_path_mask *m1, const struct f_path_mask *m2)
   return 1;
 }
 
+static int
+mpls_same(const mpls_label_stack *m1, const mpls_label_stack *m2)
+{
+  if (m1->len != m2->len)
+    return 0;
+  return !memcmp(m1->stack, m2->stack, m1->len * sizeof(u32));
+}
+
 /**
  * val_same - compare two values
  * @v1: first value
@@ -263,6 +271,8 @@ val_same(const struct f_val *v1, const struct f_val *v2)
     return pm_same(v1->val.path_mask, v2->val.path_mask);
   case T_PATH_MASK_ITEM:
     return pmi_same(&(v1->val.pmi), &(v2->val.pmi));
+  case T_MLS:
+    return mpls_same(v1->val.mls, v2->val.mls);
   case T_PATH:
   case T_CLIST:
   case T_ECLIST:
diff --git a/filter/data.h b/filter/data.h
index 4ebce73b..dc56d88e 100644
--- a/filter/data.h
+++ b/filter/data.h
@@ -58,6 +58,7 @@ enum f_type {
   T_LCLIST = 0x29,		/* Large community list */
   T_RD = 0x2a,		/* Route distinguisher for VPN addresses */
   T_PATH_MASK_ITEM = 0x2b,	/* Path mask item for path mask constructors */
+  T_MLS = 0x2c,
 
   T_SET = 0x80,
   T_PREFIX_SET = 0x81,
@@ -78,6 +79,7 @@ struct f_val {
     const struct adata *ad;
     const struct f_path_mask *path_mask;
     struct f_path_mask_item pmi;
+    mpls_label_stack *mls;
   } val;
 };
 
diff --git a/filter/f-inst.c b/filter/f-inst.c
index df908e26..dc375825 100644
--- a/filter/f-inst.c
+++ b/filter/f-inst.c
@@ -1210,6 +1210,23 @@
 
   }
 
+  INST(FI_ATTACH_MLS, 1, 0) {	/* attach_mls([stack]) */
+    NEVER_CONSTANT;
+    ARG(1, T_MLS);
+    ACCESS_EATTRS;
+    ACCESS_RTE;
+    struct rta *rta = (*fs->rte)->attrs;
+
+    const mpls_label_stack *mls = v1.val.mls;
+    for (struct nexthop *nh = &rta->nh; nh; nh = nh->next) {
+      nh->labels = mls ? mls->len : 0;
+      if (mls)
+        memcpy(&nh->label, mls->stack, mls->len * sizeof(u32));
+    }
+
+    RESULT_VOID;
+  }
+
   INST(FI_FORMAT, 1, 0) {	/* Format */
     ARG_ANY(1);
     RESULT(T_STRING, s, val_format_str(fpool, &v1));