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Diffstat (limited to 'proto/babel/packets.c')
-rw-r--r--proto/babel/packets.c115
1 files changed, 82 insertions, 33 deletions
diff --git a/proto/babel/packets.c b/proto/babel/packets.c
index d4acc170..28bf9f63 100644
--- a/proto/babel/packets.c
+++ b/proto/babel/packets.c
@@ -166,10 +166,12 @@ struct babel_parse_state {
ip_addr next_hop_ip6;
u64 router_id; /* Router ID used in subsequent updates */
u8 def_ip6_prefix[16]; /* Implicit IPv6 prefix in network order */
- u8 def_ip4_prefix[4]; /* Implicit IPv4 prefix in network order */
+ u8 def_ip4_prefix[4]; /* Implicit IPv4 prefix (AE 1) in network order */
+ u8 def_ip4_via_ip6_prefix[4]; /* Implicit IPv4 prefix (AE 4) in network order */
u8 router_id_seen; /* router_id field is valid */
u8 def_ip6_prefix_seen; /* def_ip6_prefix is valid */
u8 def_ip4_prefix_seen; /* def_ip4_prefix is valid */
+ u8 def_ip4_via_ip6_prefix_seen; /* def_ip4_via_ip6_prefix is valid */
u8 current_tlv_endpos; /* End of self-terminating TLVs (offset from start) */
u8 sadr_enabled;
u8 is_unicast;
@@ -515,9 +517,6 @@ babel_read_ihu(struct babel_tlv *hdr, union babel_msg *m,
msg->addr = IPA_NONE;
msg->sender = state->saddr;
- if (msg->ae >= BABEL_AE_MAX)
- return PARSE_IGNORE;
-
/*
* We only actually read link-local IPs. In every other case, the addr field
* will be 0 but validation will succeed. The handler takes care of these
@@ -526,17 +525,20 @@ babel_read_ihu(struct babel_tlv *hdr, union babel_msg *m,
*/
switch (msg->ae)
{
+ case BABEL_AE_WILDCARD:
+ return PARSE_SUCCESS;
+
case BABEL_AE_IP4:
if (TLV_OPT_LENGTH(tlv) < 4)
return PARSE_ERROR;
state->current_tlv_endpos += 4;
- break;
+ return PARSE_SUCCESS;
case BABEL_AE_IP6:
if (TLV_OPT_LENGTH(tlv) < 16)
return PARSE_ERROR;
state->current_tlv_endpos += 16;
- break;
+ return PARSE_SUCCESS;
case BABEL_AE_IP6_LL:
if (TLV_OPT_LENGTH(tlv) < 8)
@@ -544,10 +546,17 @@ babel_read_ihu(struct babel_tlv *hdr, union babel_msg *m,
msg->addr = ipa_from_ip6(get_ip6_ll(&tlv->addr));
state->current_tlv_endpos += 8;
- break;
+ return PARSE_SUCCESS;
+
+ /* RFC 9229 2.4 - IHU TLV MUST NOT carry the AE 4 (IPv4-via-IPv6) */
+ case BABEL_AE_IP4_VIA_IP6:
+ return PARSE_ERROR;
+
+ default:
+ return PARSE_IGNORE;
}
- return PARSE_SUCCESS;
+ return PARSE_IGNORE;
}
static uint
@@ -640,6 +649,10 @@ babel_read_next_hop(struct babel_tlv *hdr, union babel_msg *m UNUSED,
state->current_tlv_endpos += 8;
return PARSE_IGNORE;
+ /* RFC 9229 2.4 - Next Hop TLV MUST NOT carry the AE 4 (IPv4-via-IPv6) */
+ case BABEL_AE_IP4_VIA_IP6:
+ return PARSE_ERROR;
+
default:
return PARSE_IGNORE;
}
@@ -692,6 +705,42 @@ babel_write_next_hop(struct babel_tlv *hdr, ip_addr addr,
return 0;
}
+/* This is called directly from babel_read_update() to handle
+ both BABEL_AE_IP4 and BABEL_AE_IP4_VIA_IP6 encodings */
+static int
+babel_read_ip4_prefix(struct babel_tlv_update *tlv, struct babel_msg_update *msg,
+ u8 *def_prefix, u8 *def_prefix_seen, ip_addr next_hop, int len)
+{
+ if (tlv->plen > IP4_MAX_PREFIX_LENGTH)
+ return PARSE_ERROR;
+
+ /* Cannot omit data if there is no saved prefix */
+ if (tlv->omitted && !*def_prefix_seen)
+ return PARSE_ERROR;
+
+ /* Update must have next hop, unless it is retraction */
+ if (ipa_zero(next_hop) && msg->metric != BABEL_INFINITY)
+ return PARSE_ERROR;
+
+ /* Merge saved prefix and received prefix parts */
+ u8 buf[4] = {};
+ memcpy(buf, def_prefix, tlv->omitted);
+ memcpy(buf + tlv->omitted, tlv->addr, len);
+
+ ip4_addr prefix4 = get_ip4(buf);
+ net_fill_ip4(&msg->net, prefix4, tlv->plen);
+
+ if (tlv->flags & BABEL_UF_DEF_PREFIX)
+ {
+ put_ip4(def_prefix, prefix4);
+ *def_prefix_seen = 1;
+ }
+
+ msg->next_hop = next_hop;
+
+ return PARSE_SUCCESS;
+}
+
static int
babel_read_update(struct babel_tlv *hdr, union babel_msg *m,
struct babel_parse_state *state)
@@ -706,11 +755,11 @@ babel_read_update(struct babel_tlv *hdr, union babel_msg *m,
/* Length of received prefix data without omitted part */
int len = BYTES(tlv->plen) - (int) tlv->omitted;
- u8 buf[16] = {};
if ((len < 0) || ((uint) len > TLV_OPT_LENGTH(tlv)))
return PARSE_ERROR;
+ int rc;
switch (tlv->ae)
{
case BABEL_AE_WILDCARD:
@@ -724,31 +773,20 @@ babel_read_update(struct babel_tlv *hdr, union babel_msg *m,
break;
case BABEL_AE_IP4:
- if (tlv->plen > IP4_MAX_PREFIX_LENGTH)
- return PARSE_ERROR;
-
- /* Cannot omit data if there is no saved prefix */
- if (tlv->omitted && !state->def_ip4_prefix_seen)
- return PARSE_ERROR;
-
- /* Update must have next hop, unless it is retraction */
- if (ipa_zero(state->next_hop_ip4) && (msg->metric != BABEL_INFINITY))
- return PARSE_IGNORE;
-
- /* Merge saved prefix and received prefix parts */
- memcpy(buf, state->def_ip4_prefix, tlv->omitted);
- memcpy(buf + tlv->omitted, tlv->addr, len);
+ rc = babel_read_ip4_prefix(tlv, msg, state->def_ip4_prefix,
+ &state->def_ip4_prefix_seen,
+ state->next_hop_ip4, len);
+ if (rc != PARSE_SUCCESS)
+ return rc;
- ip4_addr prefix4 = get_ip4(buf);
- net_fill_ip4(&msg->net, prefix4, tlv->plen);
-
- if (tlv->flags & BABEL_UF_DEF_PREFIX)
- {
- put_ip4(state->def_ip4_prefix, prefix4);
- state->def_ip4_prefix_seen = 1;
- }
+ break;
- msg->next_hop = state->next_hop_ip4;
+ case BABEL_AE_IP4_VIA_IP6:
+ rc = babel_read_ip4_prefix(tlv, msg, state->def_ip4_via_ip6_prefix,
+ &state->def_ip4_via_ip6_prefix_seen,
+ state->next_hop_ip6, len);
+ if (rc != PARSE_SUCCESS)
+ return rc;
break;
@@ -761,6 +799,7 @@ babel_read_update(struct babel_tlv *hdr, union babel_msg *m,
return PARSE_ERROR;
/* Merge saved prefix and received prefix parts */
+ u8 buf[16] = {};
memcpy(buf, state->def_ip6_prefix, tlv->omitted);
memcpy(buf + tlv->omitted, tlv->addr, len);
@@ -863,7 +902,7 @@ babel_write_update(struct babel_tlv *hdr, union babel_msg *m,
}
else if (msg->net.type == NET_IP4)
{
- tlv->ae = BABEL_AE_IP4;
+ tlv->ae = ipa_is_ip4(msg->next_hop) ? BABEL_AE_IP4 : BABEL_AE_IP4_VIA_IP6;
tlv->plen = net4_pxlen(&msg->net);
put_ip4_px(tlv->addr, &msg->net);
}
@@ -931,7 +970,12 @@ babel_read_route_request(struct babel_tlv *hdr, union babel_msg *m,
msg->full = 1;
return PARSE_SUCCESS;
+ /*
+ * RFC 9229 2.3 - When receiving requests, AE 1 (IPv4) and AE 4
+ * (IPv4-via-IPv6) MUST be treated in the same manner.
+ */
case BABEL_AE_IP4:
+ case BABEL_AE_IP4_VIA_IP6:
if (tlv->plen > IP4_MAX_PREFIX_LENGTH)
return PARSE_ERROR;
@@ -1032,7 +1076,12 @@ babel_read_seqno_request(struct babel_tlv *hdr, union babel_msg *m,
case BABEL_AE_WILDCARD:
return PARSE_ERROR;
+ /*
+ * RFC 9229 2.3 - When receiving requests, AE 1 (IPv4) and AE 4
+ * (IPv4-via-IPv6) MUST be treated in the same manner.
+ */
case BABEL_AE_IP4:
+ case BABEL_AE_IP4_VIA_IP6:
if (tlv->plen > IP4_MAX_PREFIX_LENGTH)
return PARSE_ERROR;
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-12 14:52:51 +0000