summaryrefslogtreecommitdiff
path: root/proto/babel/packets.c
diff options
context:
space:
mode:
Diffstat (limited to 'proto/babel/packets.c')
-rw-r--r--proto/babel/packets.c126
1 files changed, 122 insertions, 4 deletions
diff --git a/proto/babel/packets.c b/proto/babel/packets.c
index 61c94cc5..f1895655 100644
--- a/proto/babel/packets.c
+++ b/proto/babel/packets.c
@@ -58,6 +58,13 @@ struct babel_tlv_ihu {
u8 addr[0];
} PACKED;
+struct babel_subtlv_timestamp {
+ u8 type;
+ u8 length;
+ u32 tstamp;
+ u32 tstamp_rcvd; /* only used in IHU */
+} PACKED;
+
struct babel_tlv_router_id {
u8 type;
u8 length;
@@ -161,6 +168,7 @@ struct babel_parse_state {
const struct babel_tlv_data* (*get_subtlv_data)(u8 type);
struct babel_proto *proto;
struct babel_iface *ifa;
+ btime received_time;
ip_addr saddr;
ip_addr next_hop_ip4;
ip_addr next_hop_ip6;
@@ -172,6 +180,7 @@ struct babel_parse_state {
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 hello_tstamp_seen; /* pkt contains a hello timestamp */
u8 current_tlv_endpos; /* End of self-terminating TLVs (offset from start) */
u8 sadr_enabled;
u8 is_unicast;
@@ -336,6 +345,7 @@ static int babel_read_update(struct babel_tlv *hdr, union babel_msg *msg, struct
static int babel_read_route_request(struct babel_tlv *hdr, union babel_msg *msg, struct babel_parse_state *state);
static int babel_read_seqno_request(struct babel_tlv *hdr, union babel_msg *msg, struct babel_parse_state *state);
static int babel_read_source_prefix(struct babel_tlv *hdr, union babel_msg *msg, struct babel_parse_state *state);
+static int babel_read_timestamp(struct babel_tlv *hdr, union babel_msg *msg, struct babel_parse_state *state);
static uint babel_write_ack(struct babel_tlv *hdr, union babel_msg *msg, struct babel_write_state *state, uint max_len);
static uint babel_write_hello(struct babel_tlv *hdr, union babel_msg *msg, struct babel_write_state *state, uint max_len);
@@ -344,6 +354,7 @@ static uint babel_write_update(struct babel_tlv *hdr, union babel_msg *msg, stru
static uint babel_write_route_request(struct babel_tlv *hdr, union babel_msg *msg, struct babel_write_state *state, uint max_len);
static uint babel_write_seqno_request(struct babel_tlv *hdr, union babel_msg *msg, struct babel_write_state *state, uint max_len);
static int babel_write_source_prefix(struct babel_tlv *hdr, net_addr *net, uint max_len);
+static int babel_write_timestamp(struct babel_tlv *hdr, u32 tstamp, u32 tstamp_rcvd, uint max_len);
static const struct babel_tlv_data tlv_data[BABEL_TLV_MAX] = {
[BABEL_TLV_ACK_REQ] = {
@@ -419,6 +430,13 @@ static const struct babel_tlv_data *get_packet_tlv_data(u8 type)
return type < sizeof(tlv_data) / sizeof(*tlv_data) ? &tlv_data[type] : NULL;
}
+static const struct babel_tlv_data timestamp_tlv_data = {
+ sizeof(struct babel_subtlv_timestamp),
+ babel_read_timestamp,
+ NULL,
+ NULL
+};
+
static const struct babel_tlv_data source_prefix_tlv_data = {
sizeof(struct babel_subtlv_source_prefix),
babel_read_source_prefix,
@@ -430,6 +448,8 @@ static const struct babel_tlv_data *get_packet_subtlv_data(u8 type)
{
switch (type)
{
+ case BABEL_SUBTLV_TIMESTAMP:
+ return &timestamp_tlv_data;
case BABEL_SUBTLV_SOURCE_PREFIX:
return &source_prefix_tlv_data;
@@ -491,16 +511,34 @@ babel_read_hello(struct babel_tlv *hdr, union babel_msg *m,
static uint
babel_write_hello(struct babel_tlv *hdr, union babel_msg *m,
- struct babel_write_state *state UNUSED, uint max_len UNUSED)
+ struct babel_write_state *state UNUSED, uint max_len)
{
struct babel_tlv_hello *tlv = (void *) hdr;
struct babel_msg_hello *msg = &m->hello;
+ uint len = sizeof(struct babel_tlv_hello);
TLV_HDR0(tlv, BABEL_TLV_HELLO);
put_u16(&tlv->seqno, msg->seqno);
put_time16(&tlv->interval, msg->interval);
- return sizeof(struct babel_tlv_hello);
+ if (msg->tstamp)
+ {
+ /*
+ * There can be a substantial delay between when the babel_msg was created
+ * and when it is serialised. We don't want this included in the RTT
+ * measurement, so replace the timestamp with the current time to get as
+ * close as possible to on-wire time for the packet.
+ */
+ u32 tstamp = current_time_now() TO_US;
+
+ int l = babel_write_timestamp(hdr, tstamp, 0, max_len);
+ if (l < 0)
+ return 0;
+
+ len += l;
+ }
+
+ return len;
}
static int
@@ -565,6 +603,7 @@ babel_write_ihu(struct babel_tlv *hdr, union babel_msg *m,
{
struct babel_tlv_ihu *tlv = (void *) hdr;
struct babel_msg_ihu *msg = &m->ihu;
+ uint len = sizeof(*tlv);
if (ipa_is_link_local(msg->addr) && max_len < sizeof(struct babel_tlv_ihu) + 8)
return 0;
@@ -576,12 +615,24 @@ babel_write_ihu(struct babel_tlv *hdr, union babel_msg *m,
if (!ipa_is_link_local(msg->addr))
{
tlv->ae = BABEL_AE_WILDCARD;
- return sizeof(struct babel_tlv_ihu);
+ goto out;
}
put_ip6_ll(&tlv->addr, msg->addr);
tlv->ae = BABEL_AE_IP6_LL;
hdr->length += 8;
- return sizeof(struct babel_tlv_ihu) + 8;
+ len += 8;
+
+out:
+ if (msg->tstamp)
+ {
+ int l = babel_write_timestamp(hdr, msg->tstamp, msg->tstamp_rcvd, max_len);
+ if (l < 0)
+ return 0;
+
+ len += l;
+ }
+
+ return len;
}
static int
@@ -1249,6 +1300,66 @@ babel_write_source_prefix(struct babel_tlv *hdr, net_addr *n, uint max_len)
return len;
}
+static int
+babel_read_timestamp(struct babel_tlv *hdr, union babel_msg *msg,
+ struct babel_parse_state *state)
+{
+ struct babel_subtlv_timestamp *tlv = (void *) hdr;
+
+ switch (msg->type)
+ {
+ case BABEL_TLV_HELLO:
+ if (tlv->length < 4)
+ return PARSE_ERROR;
+
+ msg->hello.tstamp = get_u32(&tlv->tstamp);
+ msg->hello.pkt_received = state->received_time;
+ state->hello_tstamp_seen = 1;
+ break;
+
+ case BABEL_TLV_IHU:
+ if (tlv->length < 8)
+ return PARSE_ERROR;
+
+ /* RTT calculation relies on a Hello always being present with an IHU */
+ if (!state->hello_tstamp_seen)
+ break;
+
+ msg->ihu.tstamp = get_u32(&tlv->tstamp);
+ msg->ihu.tstamp_rcvd = get_u32(&tlv->tstamp_rcvd);
+ msg->ihu.pkt_received = state->received_time;
+ break;
+
+ default:
+ return PARSE_ERROR;
+ }
+
+ return PARSE_SUCCESS;
+}
+
+static int
+babel_write_timestamp(struct babel_tlv *hdr, u32 tstamp, u32 tstamp_rcvd, uint max_len)
+{
+ struct babel_subtlv_timestamp *tlv = (void *) NEXT_TLV(hdr);
+ uint len = sizeof(*tlv);
+
+ if (hdr->type == BABEL_TLV_HELLO)
+ len -= 4;
+
+ if (len > max_len)
+ return -1;
+
+ TLV_HDR(tlv, BABEL_SUBTLV_TIMESTAMP, len);
+ hdr->length += len;
+
+ put_u32(&tlv->tstamp, tstamp);
+
+ if (hdr->type == BABEL_TLV_IHU)
+ put_u32(&tlv->tstamp_rcvd, tstamp_rcvd);
+
+ return len;
+}
+
static inline int
babel_read_subtlvs(struct babel_tlv *hdr,
union babel_msg *msg,
@@ -1518,6 +1629,13 @@ babel_process_packet(struct babel_iface *ifa,
.saddr = saddr,
.next_hop_ip6 = saddr,
.sadr_enabled = babel_sadr_enabled(p),
+
+ /*
+ * The core updates current_time() after returning from poll(), so this is
+ * actually the time the packet was received, even though there may have
+ * been a bit of delay before we got to process it
+ */
+ .received_time = current_time(),
};
if ((pkt->magic != BABEL_MAGIC) || (pkt->version != BABEL_VERSION))
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-27 02:24:02 +0000