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Diffstat (limited to 'proto/babel/packets.c')
-rw-r--r--proto/babel/packets.c199
1 files changed, 172 insertions, 27 deletions
diff --git a/proto/babel/packets.c b/proto/babel/packets.c
index 70cfc196..b52c2ddf 100644
--- a/proto/babel/packets.c
+++ b/proto/babel/packets.c
@@ -112,7 +112,8 @@ struct babel_parse_state {
struct babel_proto *proto;
struct babel_iface *ifa;
ip_addr saddr;
- ip_addr next_hop;
+ ip_addr next_hop_ip4;
+ 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 */
@@ -130,7 +131,8 @@ enum parse_result {
struct babel_write_state {
u64 router_id;
u8 router_id_seen;
-// ip_addr next_hop;
+ ip_addr next_hop_ip4;
+ ip_addr next_hop_ip6;
};
@@ -163,6 +165,21 @@ put_time16(void *p, u16 v)
}
static inline void
+read_ip4_px(net_addr *n, const void *p, uint plen)
+{
+ ip4_addr addr = {0};
+ memcpy(&addr, p, BYTES(plen));
+ net_fill_ip4(n, ip4_ntoh(addr), plen);
+}
+
+static inline void
+put_ip4_px(void *p, net_addr *n)
+{
+ ip4_addr addr = ip4_hton(net4_prefix(n));
+ memcpy(p, &addr, NET_SIZE(n));
+}
+
+static inline void
read_ip6_px(net_addr *n, const void *p, uint plen)
{
ip6_addr addr = IPA_NONE;
@@ -432,21 +449,24 @@ babel_read_next_hop(struct babel_tlv *hdr, union babel_msg *m UNUSED,
return PARSE_ERROR;
case BABEL_AE_IP4:
- /* TODO */
+ if (TLV_OPT_LENGTH(tlv) < sizeof(ip4_addr))
+ return PARSE_ERROR;
+
+ state->next_hop_ip4 = ipa_from_ip4(get_ip4(&tlv->addr));
return PARSE_IGNORE;
case BABEL_AE_IP6:
if (TLV_OPT_LENGTH(tlv) < sizeof(ip6_addr))
return PARSE_ERROR;
- state->next_hop = ipa_from_ip6(get_ip6(&tlv->addr));
+ state->next_hop_ip6 = ipa_from_ip6(get_ip6(&tlv->addr));
return PARSE_IGNORE;
case BABEL_AE_IP6_LL:
if (TLV_OPT_LENGTH(tlv) < 8)
return PARSE_ERROR;
- state->next_hop = ipa_from_ip6(get_ip6_ll(&tlv->addr));
+ state->next_hop_ip6 = ipa_from_ip6(get_ip6_ll(&tlv->addr));
return PARSE_IGNORE;
default:
@@ -456,6 +476,51 @@ babel_read_next_hop(struct babel_tlv *hdr, union babel_msg *m UNUSED,
return PARSE_IGNORE;
}
+/* This is called directly from babel_write_update() and returns -1 if a next
+ hop should be written but there is not enough space. */
+static int
+babel_write_next_hop(struct babel_tlv *hdr, ip_addr addr,
+ struct babel_write_state *state, uint max_len)
+{
+ struct babel_tlv_next_hop *tlv = (void *) hdr;
+
+ if (ipa_zero(addr))
+ {
+ /* Should not happen */
+ return 0;
+ }
+ else if (ipa_is_ip4(addr) && !ipa_equal(addr, state->next_hop_ip4))
+ {
+ uint len = sizeof(struct babel_tlv_next_hop) + sizeof(ip4_addr);
+ if (len > max_len)
+ return -1;
+
+ TLV_HDR(tlv, BABEL_TLV_NEXT_HOP, len);
+
+ tlv->ae = BABEL_AE_IP4;
+ put_ip4(&tlv->addr, ipa_to_ip4(addr));
+ state->next_hop_ip4 = addr;
+
+ return len;
+ }
+ else if (ipa_is_ip6(addr) && !ipa_equal(addr, state->next_hop_ip6))
+ {
+ uint len = sizeof(struct babel_tlv_next_hop) + sizeof(ip6_addr);
+ if (len > max_len)
+ return -1;
+
+ TLV_HDR(tlv, BABEL_TLV_NEXT_HOP, len);
+
+ tlv->ae = BABEL_AE_IP6;
+ put_ip6(&tlv->addr, ipa_to_ip6(addr));
+ state->next_hop_ip6 = addr;
+
+ return len;
+ }
+
+ return 0;
+}
+
static int
babel_read_update(struct babel_tlv *hdr, union babel_msg *m,
struct babel_parse_state *state)
@@ -488,8 +553,33 @@ babel_read_update(struct babel_tlv *hdr, union babel_msg *m,
break;
case BABEL_AE_IP4:
- /* TODO */
- return PARSE_IGNORE;
+ 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;
+
+ /* Need next hop for v4 routes */
+ if (ipa_zero(state->next_hop_ip4))
+ return PARSE_ERROR;
+
+ /* Merge saved prefix and received prefix parts */
+ memcpy(buf, state->def_ip4_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_FLAG_DEF_PREFIX)
+ {
+ put_ip4(state->def_ip4_prefix, prefix4);
+ state->def_ip4_prefix_seen = 1;
+ }
+
+ msg->next_hop = state->next_hop_ip4;
+
+ break;
case BABEL_AE_IP6:
if (tlv->plen > IP6_MAX_PREFIX_LENGTH)
@@ -503,20 +593,23 @@ babel_read_update(struct babel_tlv *hdr, union babel_msg *m,
memcpy(buf, state->def_ip6_prefix, tlv->omitted);
memcpy(buf + tlv->omitted, tlv->addr, len);
- ip6_addr prefix = get_ip6(buf);
- net_fill_ip6(&msg->net, prefix, tlv->plen);
+ ip6_addr prefix6 = get_ip6(buf);
+ net_fill_ip6(&msg->net, prefix6, tlv->plen);
if (tlv->flags & BABEL_FLAG_DEF_PREFIX)
{
- put_ip6(state->def_ip6_prefix, prefix);
+ put_ip6(state->def_ip6_prefix, prefix6);
state->def_ip6_prefix_seen = 1;
}
if (tlv->flags & BABEL_FLAG_ROUTER_ID)
{
- state->router_id = ((u64) _I2(prefix)) << 32 | _I3(prefix);
+ state->router_id = ((u64) _I2(prefix6)) << 32 | _I3(prefix6);
state->router_id_seen = 1;
}
+
+ msg->next_hop = state->next_hop_ip6;
+
break;
case BABEL_AE_IP6_LL:
@@ -535,7 +628,6 @@ babel_read_update(struct babel_tlv *hdr, union babel_msg *m,
}
msg->router_id = state->router_id;
- msg->next_hop = state->next_hop;
msg->sender = state->saddr;
return PARSE_SUCCESS;
@@ -545,7 +637,6 @@ static uint
babel_write_update(struct babel_tlv *hdr, union babel_msg *m,
struct babel_write_state *state, uint max_len)
{
- struct babel_tlv_update *tlv = (void *) hdr;
struct babel_msg_update *msg = &m->update;
uint len0 = 0;
@@ -554,15 +645,34 @@ babel_write_update(struct babel_tlv *hdr, union babel_msg *m,
* both of them. There is enough space for the Router-ID TLV, because
* sizeof(struct babel_tlv_router_id) == sizeof(struct babel_tlv_update).
*
- * Router ID is not used for retractions, so do not us it in such case.
+ * Router ID is not used for retractions, so do not use it in such case.
*/
if ((msg->metric < BABEL_INFINITY) &&
(!state->router_id_seen || (msg->router_id != state->router_id)))
{
len0 = babel_write_router_id(hdr, msg->router_id, state, max_len);
- tlv = (struct babel_tlv_update *) NEXT_TLV(tlv);
+ hdr = NEXT_TLV(hdr);
}
+ /*
+ * We also may add Next Hop TLV for regular updates. It may fail for not
+ * enough space or it may be unnecessary as the next hop is the same as the
+ * last one already announced. So we handle all three cases.
+ */
+ if (msg->metric < BABEL_INFINITY)
+ {
+ int l = babel_write_next_hop(hdr, msg->next_hop, state, max_len - len0);
+ if (l < 0)
+ return 0;
+
+ if (l)
+ {
+ len0 += l;
+ hdr = NEXT_TLV(hdr);
+ }
+ }
+
+ struct babel_tlv_update *tlv = (void *) hdr;
uint len = sizeof(struct babel_tlv_update) + NET_SIZE(&msg->net);
if (len0 + len > max_len)
@@ -576,6 +686,12 @@ babel_write_update(struct babel_tlv *hdr, union babel_msg *m,
tlv->ae = BABEL_AE_WILDCARD;
tlv->plen = 0;
}
+ else if (msg->net.type == NET_IP4)
+ {
+ tlv->ae = BABEL_AE_IP4;
+ tlv->plen = net4_pxlen(&msg->net);
+ put_ip4_px(tlv->addr, &msg->net);
+ }
else
{
tlv->ae = BABEL_AE_IP6;
@@ -610,8 +726,14 @@ babel_read_route_request(struct babel_tlv *hdr, union babel_msg *m,
return PARSE_SUCCESS;
case BABEL_AE_IP4:
- /* TODO */
- return PARSE_IGNORE;
+ if (tlv->plen > IP4_MAX_PREFIX_LENGTH)
+ return PARSE_ERROR;
+
+ if (TLV_OPT_LENGTH(tlv) < BYTES(tlv->plen))
+ return PARSE_ERROR;
+
+ read_ip4_px(&msg->net, tlv->addr, tlv->plen);
+ return PARSE_SUCCESS;
case BABEL_AE_IP6:
if (tlv->plen > IP6_MAX_PREFIX_LENGTH)
@@ -652,6 +774,12 @@ babel_write_route_request(struct babel_tlv *hdr, union babel_msg *m,
tlv->ae = BABEL_AE_WILDCARD;
tlv->plen = 0;
}
+ else if (msg->net.type == NET_IP4)
+ {
+ tlv->ae = BABEL_AE_IP4;
+ tlv->plen = net4_pxlen(&msg->net);
+ put_ip4_px(tlv->addr, &msg->net);
+ }
else
{
tlv->ae = BABEL_AE_IP6;
@@ -684,8 +812,14 @@ babel_read_seqno_request(struct babel_tlv *hdr, union babel_msg *m,
return PARSE_ERROR;
case BABEL_AE_IP4:
- /* TODO */
- return PARSE_IGNORE;
+ if (tlv->plen > IP4_MAX_PREFIX_LENGTH)
+ return PARSE_ERROR;
+
+ if (TLV_OPT_LENGTH(tlv) < BYTES(tlv->plen))
+ return PARSE_ERROR;
+
+ read_ip4_px(&msg->net, tlv->addr, tlv->plen);
+ return PARSE_SUCCESS;
case BABEL_AE_IP6:
if (tlv->plen > IP6_MAX_PREFIX_LENGTH)
@@ -720,12 +854,23 @@ babel_write_seqno_request(struct babel_tlv *hdr, union babel_msg *m,
return 0;
TLV_HDR(tlv, BABEL_TLV_SEQNO_REQUEST, len);
- tlv->ae = BABEL_AE_IP6;
- tlv->plen = net6_pxlen(&msg->net);
+
+ if (msg->net.type == NET_IP4)
+ {
+ tlv->ae = BABEL_AE_IP4;
+ tlv->plen = net4_pxlen(&msg->net);
+ put_ip4_px(tlv->addr, &msg->net);
+ }
+ else
+ {
+ tlv->ae = BABEL_AE_IP6;
+ tlv->plen = net6_pxlen(&msg->net);
+ put_ip6_px(tlv->addr, &msg->net);
+ }
+
put_u16(&tlv->seqno, msg->seqno);
tlv->hop_count = msg->hop_count;
put_u64(&tlv->router_id, msg->router_id);
- put_ip6_px(tlv->addr, &msg->net);
return len;
}
@@ -799,7 +944,7 @@ static uint
babel_write_queue(struct babel_iface *ifa, list *queue)
{
struct babel_proto *p = ifa->proto;
- struct babel_write_state state = {};
+ struct babel_write_state state = { .next_hop_ip6 = ifa->addr };
if (EMPTY_LIST(*queue))
return 0;
@@ -935,10 +1080,10 @@ babel_process_packet(struct babel_pkt_header *pkt, int len,
byte *end = (byte *)pkt + plen;
struct babel_parse_state state = {
- .proto = p,
- .ifa = ifa,
- .saddr = saddr,
- .next_hop = saddr,
+ .proto = p,
+ .ifa = ifa,
+ .saddr = saddr,
+ .next_hop_ip6 = saddr,
};
if ((pkt->magic != BABEL_MAGIC) || (pkt->version != BABEL_VERSION))
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-26 01:46:19 +0000