net: sctp: implement rfc6458, 5.3.5. SCTP_RCVINFO cmsg support
This patch implements section 5.3.5. of RFC6458, that is, support
for 'SCTP Receive Information Structure' (SCTP_RCVINFO) which is
placed into ancillary data cmsghdr structure for each recvmsg()
call.
This option can be enabled/disabled via setsockopt(2) on SOL_SCTP
level by setting an int value with 1/0 for SCTP_RECVRCVINFO in user
space applications as per RFC6458, section 8.1.29.
The sctp_rcvinfo structure is defined as per RFC as below ...
struct sctp_rcvinfo {
uint16_t rcv_sid;
uint16_t rcv_ssn;
uint16_t rcv_flags;
<-- 2 bytes hole -->
uint32_t rcv_ppid;
uint32_t rcv_tsn;
uint32_t rcv_cumtsn;
uint32_t rcv_context;
sctp_assoc_t rcv_assoc_id;
};
... and provided under cmsg_level IPPROTO_SCTP, cmsg_type
SCTP_RCVINFO, while cmsg_data[] contains struct sctp_rcvinfo.
An sctp_rcvinfo item always corresponds to the data in msg_iov.
Joint work with Daniel Borkmann.
Signed-off-by: Geir Ola Vaagland <geirola@gmail.com>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/uapi/linux/sctp.h b/include/uapi/linux/sctp.h
index a387761..29b81bb 100644
--- a/include/uapi/linux/sctp.h
+++ b/include/uapi/linux/sctp.h
@@ -95,6 +95,7 @@
#define SCTP_GET_ASSOC_ID_LIST 29 /* Read only */
#define SCTP_AUTO_ASCONF 30
#define SCTP_PEER_ADDR_THLDS 31
+#define SCTP_RECVRCVINFO 32
/* Internal Socket Options. Some of the sctp library functions are
* implemented using these socket options.
@@ -110,8 +111,7 @@
#define SCTP_SOCKOPT_CONNECTX3 111 /* CONNECTX requests (updated) */
#define SCTP_GET_ASSOC_STATS 112 /* Read only */
-/*
- * 5.2.1 SCTP Initiation Structure (SCTP_INIT)
+/* 5.3.1 SCTP Initiation Structure (SCTP_INIT)
*
* This cmsghdr structure provides information for initializing new
* SCTP associations with sendmsg(). The SCTP_INITMSG socket option
@@ -121,7 +121,6 @@
* cmsg_level cmsg_type cmsg_data[]
* ------------ ------------ ----------------------
* IPPROTO_SCTP SCTP_INIT struct sctp_initmsg
- *
*/
struct sctp_initmsg {
__u16 sinit_num_ostreams;
@@ -130,8 +129,7 @@
__u16 sinit_max_init_timeo;
};
-/*
- * 5.2.2 SCTP Header Information Structure (SCTP_SNDRCV)
+/* 5.3.2 SCTP Header Information Structure (SCTP_SNDRCV)
*
* This cmsghdr structure specifies SCTP options for sendmsg() and
* describes SCTP header information about a received message through
@@ -140,7 +138,6 @@
* cmsg_level cmsg_type cmsg_data[]
* ------------ ------------ ----------------------
* IPPROTO_SCTP SCTP_SNDRCV struct sctp_sndrcvinfo
- *
*/
struct sctp_sndrcvinfo {
__u16 sinfo_stream;
@@ -170,13 +167,32 @@
sctp_assoc_t snd_assoc_id;
};
+/* 5.3.5 SCTP Receive Information Structure (SCTP_RCVINFO)
+ *
+ * This cmsghdr structure describes SCTP receive information
+ * about a received message through recvmsg().
+ *
+ * cmsg_level cmsg_type cmsg_data[]
+ * ------------ ------------ -------------------
+ * IPPROTO_SCTP SCTP_RCVINFO struct sctp_rcvinfo
+ */
+struct sctp_rcvinfo {
+ __u16 rcv_sid;
+ __u16 rcv_ssn;
+ __u16 rcv_flags;
+ __u32 rcv_ppid;
+ __u32 rcv_tsn;
+ __u32 rcv_cumtsn;
+ __u32 rcv_context;
+ sctp_assoc_t rcv_assoc_id;
+};
+
/*
* sinfo_flags: 16 bits (unsigned integer)
*
* This field may contain any of the following flags and is composed of
* a bitwise OR of these values.
*/
-
enum sctp_sinfo_flags {
SCTP_UNORDERED = 1, /* Send/receive message unordered. */
SCTP_ADDR_OVER = 2, /* Override the primary destination. */
@@ -199,6 +215,8 @@
#define SCTP_SNDRCV SCTP_SNDRCV
SCTP_SNDINFO, /* 5.3.4 SCTP Send Information Structure */
#define SCTP_SNDINFO SCTP_SNDINFO
+ SCTP_RCVINFO, /* 5.3.5 SCTP Receive Information Structure */
+#define SCTP_RCVINFO SCTP_RCVINFO
} sctp_cmsg_t;
/*