sctp: add SCTP_PR_ASSOC_STATUS on sctp sockopt

This patch adds SCTP_PR_ASSOC_STATUS to sctp sockopt, which is used
to dump the prsctp statistics info from the asoc. The prsctp statistics
includes abandoned_sent/unsent from the asoc. abandoned_sent is the
count of the packets we drop packets from retransmit/transmited queue,
and abandoned_unsent is the count of the packets we drop from out_queue
according to the policy.

Note: another option for prsctp statistics dump described in rfc is
SCTP_PR_STREAM_STATUS, which is used to dump the prsctp statistics
info from each stream. But by now, linux doesn't yet have per stream
statistics info, it needs rfc6525 to be implemented. As the prsctp
statistics for each stream has to be based on per stream statistics,
we will delay it until rfc6525 is done in linux.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 12 insertions, 0 deletions

diff --git a/include/uapi/linux/sctp.h b/include/uapi/linux/sctp.h
index 984cf2e..d304f4c 100644
--- a/include/uapi/linux/sctp.h
+++ b/include/uapi/linux/sctp.h
@@ -114,6 +114,7 @@ typedef __s32 sctp_assoc_t;
 #define SCTP_GET_ASSOC_STATS	112	/* Read only */
 #define SCTP_PR_SUPPORTED	113
 #define SCTP_DEFAULT_PRINFO	114
+#define SCTP_PR_ASSOC_STATUS	115
 
 /* PR-SCTP policies */
 #define SCTP_PR_SCTP_NONE	0x0000
@@ -926,6 +927,17 @@ struct sctp_paddrthlds {
 	__u16 spt_pathpfthld;
 };
 
+/*
+ * Socket Option for Getting the Association/Stream-Specific PR-SCTP Status
+ */
+struct sctp_prstatus {
+	sctp_assoc_t sprstat_assoc_id;
+	__u16 sprstat_sid;
+	__u16 sprstat_policy;
+	__u64 sprstat_abandoned_unsent;
+	__u64 sprstat_abandoned_sent;
+};
+
 struct sctp_default_prinfo {
 	sctp_assoc_t pr_assoc_id;
 	__u32 pr_value;