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authorXin Long <lucien.xin@gmail.com>2021-06-22 21:04:52 +0300
committerDavid S. Miller <davem@davemloft.net>2021-06-22 21:28:52 +0300
commitfe59379b9ab7ddad157f5379fa47dbf84c9b5e09 (patch)
tree53972eaae7c47412ba8aca07bd05b18af1b2b7aa /net/sctp/sm_statefuns.c
parent92548ec2f1f92d0c0b60ce59592b645571672568 (diff)
downloadlinux-fe59379b9ab7ddad157f5379fa47dbf84c9b5e09.tar.xz
sctp: do the basic send and recv for PLPMTUD probe
This patch does exactly what rfc8899#section-6.2.1.2 says: The SCTP sender needs to be able to determine the total size of a probe packet. The HEARTBEAT chunk could carry a Heartbeat Information parameter that includes, besides the information suggested in [RFC4960], the probe size to help an implementation associate a HEARTBEAT ACK with the size of probe that was sent. The sender could also use other methods, such as sending a nonce and verifying the information returned also contains the corresponding nonce. The length of the PAD chunk is computed by reducing the probing size by the size of the SCTP common header and the HEARTBEAT chunk. Note that HB ACK chunk will carry back whatever HB chunk carried, including the probe_size we put it in; We also check hbinfo->probe_size in the HB ACK against link->pl.probe_size to validate this HB ACK chunk. v1->v2: - Remove the unused 'sp' and add static for sctp_packet_bundle_pad(). Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/sctp/sm_statefuns.c')
-rw-r--r--net/sctp/sm_statefuns.c20
1 files changed, 18 insertions, 2 deletions
diff --git a/net/sctp/sm_statefuns.c b/net/sctp/sm_statefuns.c
index 3b99eda50618..8edb9186112a 100644
--- a/net/sctp/sm_statefuns.c
+++ b/net/sctp/sm_statefuns.c
@@ -1004,7 +1004,7 @@ static enum sctp_disposition sctp_sf_heartbeat(
struct sctp_chunk *reply;
/* Send a heartbeat to our peer. */
- reply = sctp_make_heartbeat(asoc, transport);
+ reply = sctp_make_heartbeat(asoc, transport, 0);
if (!reply)
return SCTP_DISPOSITION_NOMEM;
@@ -1104,8 +1104,15 @@ enum sctp_disposition sctp_sf_send_probe(struct net *net,
struct sctp_cmd_seq *commands)
{
struct sctp_transport *transport = (struct sctp_transport *)arg;
+ struct sctp_chunk *reply;
+
+ if (!sctp_transport_pl_enabled(transport))
+ return SCTP_DISPOSITION_CONSUME;
- /* The actual handling will be performed here in a later patch. */
+ reply = sctp_make_heartbeat(asoc, transport, transport->pl.probe_size);
+ if (!reply)
+ return SCTP_DISPOSITION_NOMEM;
+ sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
sctp_add_cmd_sf(commands, SCTP_CMD_PROBE_TIMER_UPDATE,
SCTP_TRANSPORT(transport));
@@ -1260,6 +1267,15 @@ enum sctp_disposition sctp_sf_backbeat_8_3(struct net *net,
if (hbinfo->hb_nonce != link->hb_nonce)
return SCTP_DISPOSITION_DISCARD;
+ if (hbinfo->probe_size) {
+ if (hbinfo->probe_size != link->pl.probe_size ||
+ !sctp_transport_pl_enabled(link))
+ return SCTP_DISPOSITION_DISCARD;
+
+ /* The actual handling will be performed here in a later patch. */
+ return SCTP_DISPOSITION_CONSUME;
+ }
+
max_interval = link->hbinterval + link->rto;
/* Check if the timestamp looks valid. */