net: sctp: implement rfc6458, 5.3.4. SCTP_SNDINFO cmsg support
This patch implements section 5.3.4. of RFC6458, that is, support
for 'SCTP Send Information Structure' (SCTP_SNDINFO) which can be
placed into ancillary data cmsghdr structure for sendmsg() calls.
The sctp_sndinfo structure is defined as per RFC as below ...
struct sctp_sndinfo {
uint16_t snd_sid;
uint16_t snd_flags;
uint32_t snd_ppid;
uint32_t snd_context;
sctp_assoc_t snd_assoc_id;
};
... and supplied under cmsg_level IPPROTO_SCTP, cmsg_type
SCTP_SNDINFO, while cmsg_data[] contains struct sctp_sndinfo.
An sctp_sndinfo 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 266022a..a387761 100644
--- a/include/uapi/linux/sctp.h
+++ b/include/uapi/linux/sctp.h
@@ -154,6 +154,22 @@
sctp_assoc_t sinfo_assoc_id;
};
+/* 5.3.4 SCTP Send Information Structure (SCTP_SNDINFO)
+ *
+ * This cmsghdr structure specifies SCTP options for sendmsg().
+ *
+ * cmsg_level cmsg_type cmsg_data[]
+ * ------------ ------------ -------------------
+ * IPPROTO_SCTP SCTP_SNDINFO struct sctp_sndinfo
+ */
+struct sctp_sndinfo {
+ __u16 snd_sid;
+ __u16 snd_flags;
+ __u32 snd_ppid;
+ __u32 snd_context;
+ sctp_assoc_t snd_assoc_id;
+};
+
/*
* sinfo_flags: 16 bits (unsigned integer)
*
@@ -177,10 +193,12 @@
/* These are cmsg_types. */
typedef enum sctp_cmsg_type {
- SCTP_INIT, /* 5.2.1 SCTP Initiation Structure */
+ SCTP_INIT, /* 5.2.1 SCTP Initiation Structure */
#define SCTP_INIT SCTP_INIT
- SCTP_SNDRCV, /* 5.2.2 SCTP Header Information Structure */
+ SCTP_SNDRCV, /* 5.2.2 SCTP Header Information Structure */
#define SCTP_SNDRCV SCTP_SNDRCV
+ SCTP_SNDINFO, /* 5.3.4 SCTP Send Information Structure */
+#define SCTP_SNDINFO SCTP_SNDINFO
} sctp_cmsg_t;
/*