From 98fd158e28d89f10ee7a41b4f6a14fbd0021ef35 Mon Sep 17 00:00:00 2001
From: Maria Matejka <mq@ucw.cz>
Date: Wed, 13 Apr 2022 17:05:12 +0200
Subject: RIP: fixed the EA_RIP_FROM attribute

The interface pointer was improperly converted to u32 and back. Fixing
this by explicitly allocating an adata structure for it. It's not so
memory efficient, we'll optimize this later.
---
 proto/rip/rip.c | 54 ++++++++++++++++++++++++++++++++++++------------------
 1 file changed, 36 insertions(+), 18 deletions(-)

(limited to 'proto')

diff --git a/proto/rip/rip.c b/proto/rip/rip.c
index 9d8b9849..6ca7a6b5 100644
--- a/proto/rip/rip.c
+++ b/proto/rip/rip.c
@@ -124,6 +124,11 @@ static inline int rip_same_rte(struct rip_rte *a, struct rip_rte *b)
 static inline int rip_valid_rte(struct rip_rte *rt)
 { return rt->from->ifa != NULL; }
 
+struct rip_iface_adata {
+  struct adata ad;
+  struct iface *iface;
+};
+
 /**
  * rip_announce_rte - announce route from RIP routing table to the core
  * @p: RIP instance
@@ -188,25 +193,37 @@ rip_announce_rte(struct rip_proto *p, struct rip_entry *en)
       a0.nh.iface = rt->from->ifa->iface;
     }
 
-    a0.eattrs = alloca(sizeof(ea_list) + 3*sizeof(eattr));
-    memset(a0.eattrs, 0, sizeof(ea_list)); /* Zero-ing only the ea_list header */
-    a0.eattrs->count = 3;
-    a0.eattrs->attrs[0] = (eattr) {
-      .id = EA_RIP_METRIC,
-      .type = EAF_TYPE_INT,
-      .u.data = rt_metric,
-    };
-    a0.eattrs->attrs[1] = (eattr) {
-      .id = EA_RIP_TAG,
-      .type = EAF_TYPE_INT,
-      .u.data = rt_tag,
-    };
-    a0.eattrs->attrs[2] = (eattr) {
-      .id = EA_RIP_FROM,
-      .type = EAF_TYPE_PTR,
-      .u.data = (uintptr_t) a0.nh.iface,
+    struct {
+      ea_list l;
+      eattr e[3];
+      struct rip_iface_adata riad;
+    } ea_block = {
+      .l = { .count = 3, },
+      .e = {
+	{
+	  .id = EA_RIP_METRIC,
+	  .type = EAF_TYPE_INT,
+	  .u.data = rt_metric,
+	},
+	{
+	  .id = EA_RIP_TAG,
+	  .type = EAF_TYPE_INT,
+	  .u.data = rt_tag,
+	},
+	{
+	  .id = EA_RIP_FROM,
+	  .type = EAF_TYPE_IFACE,
+	  .u.ptr = &ea_block.riad.ad,
+	}
+      },
+      .riad = {
+	.ad = { .length = sizeof(struct rip_iface_adata) - sizeof(struct adata) },
+	.iface = a0.nh.iface,
+      },
     };
 
+    a0.eattrs = &ea_block.l;
+
     rta *a = rta_lookup(&a0);
     rte *e = rte_get_temp(a, p->p.main_source);
 
@@ -323,7 +340,8 @@ rip_rt_notify(struct proto *P, struct channel *ch UNUSED, struct network *net, s
     /* Update */
     u32 rt_tag = ea_get_int(new->attrs->eattrs, EA_RIP_TAG, 0);
     u32 rt_metric = ea_get_int(new->attrs->eattrs, EA_RIP_METRIC, 1);
-    struct iface *rt_from = (struct iface *) ea_get_int(new->attrs->eattrs, EA_RIP_FROM, 0);
+    const eattr *rie = ea_find(new->attrs->eattrs, EA_RIP_FROM);
+    struct iface *rt_from = rie ? ((struct rip_iface_adata *) rie->u.ptr)->iface : NULL;
 
     if (rt_metric > p->infinity)
     {
-- 
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