net: sctp: introduce uapi header for sctp

This patch introduces an UAPI header for the SCTP protocol,
so that we can facilitate the maintenance and development of
user land applications or libraries, in particular in terms
of header synchronization.

To not break compatibility, some fragments from lksctp-tools'
netinet/sctp.h have been carefully included, while taking care
that neither kernel nor user land breaks, so both compile fine
with this change (for lksctp-tools I tested with the old
netinet/sctp.h header and with a newly adapted one that includes
the uapi sctp header). lksctp-tools smoke test run through
successfully as well in both cases.

Suggested-by: Neil Horman <nhorman@tuxdriver.com>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: Vlad Yasevich <vyasevich@gmail.com>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

5 files changed, 78 insertions, 16 deletions

diff --git a/fs/dlm/lowcomms.c b/fs/dlm/lowcomms.c
index 4f5ad246582f..d0ccd2fd79eb 100644
--- a/fs/dlm/lowcomms.c
+++ b/fs/dlm/lowcomms.c
@@ -52,8 +52,8 @@
 #include <linux/mutex.h>
 #include <linux/sctp.h>
 #include <linux/slab.h>
+#include <linux/sctp.h>
 #include <net/sctp/sctp.h>
-#include <net/sctp/user.h>
 #include <net/ipv6.h>
 
 #include "dlm_internal.h"
diff --git a/include/linux/sctp.h b/include/linux/sctp.h
index c11a28706fa4..3bfe8d6ee248 100644
--- a/include/linux/sctp.h
+++ b/include/linux/sctp.h
@@ -53,7 +53,9 @@
 
 #include <linux/in.h>           /* We need in_addr.  */
 #include <linux/in6.h>          /* We need in6_addr.  */
+#include <linux/skbuff.h>
 
+#include <uapi/linux/sctp.h>
 
 /* Section 3.1.  SCTP Common Header Format */
 typedef struct sctphdr {
@@ -63,14 +65,10 @@ typedef struct sctphdr {
         __le32 checksum;
 } __packed sctp_sctphdr_t;
 
-#ifdef __KERNEL__
-#include <linux/skbuff.h>
-
 static inline struct sctphdr *sctp_hdr(const struct sk_buff *skb)
 {
         return (struct sctphdr *)skb_transport_header(skb);
 }
-#endif
 
 /* Section 3.2.  Chunk Field Descriptions. */
 typedef struct sctp_chunkhdr {
diff --git a/include/net/sctp/constants.h b/include/net/sctp/constants.h
index a7dd5c50df79..ca50e0751e47 100644
--- a/include/net/sctp/constants.h
+++ b/include/net/sctp/constants.h
@@ -49,7 +49,6 @@
 
 #include <linux/sctp.h>
 #include <linux/ipv6.h> /* For ipv6hdr. */
-#include <net/sctp/user.h>
 #include <net/tcp_states.h>  /* For TCP states used in sctp_sock_state_t */
 
 /* Value used for stream negotiation. */
diff --git a/include/uapi/linux/Kbuild b/include/uapi/linux/Kbuild
index 5c8a1d25e21c..7df190525337 100644
--- a/include/uapi/linux/Kbuild
+++ b/include/uapi/linux/Kbuild
@@ -331,6 +331,7 @@ header-y += rtnetlink.h
 header-y += scc.h
 header-y += sched.h
 header-y += screen_info.h
+header-y += sctp.h
 header-y += sdla.h
 header-y += seccomp.h
 header-y += securebits.h
diff --git a/include/net/sctp/user.h b/include/uapi/linux/sctp.h
index 9a0ae091366d..66b466e4ca08 100644
--- a/include/net/sctp/user.h
+++ b/include/uapi/linux/sctp.h
@@ -42,15 +42,17 @@
  *    Jon Grimm                <jgrimm@us.ibm.com>
  *    Daisy Chang              <daisyc@us.ibm.com>
  *    Ryan Layer               <rmlayer@us.ibm.com>
- *    Ardelle Fan              <ardelle.fan@intel.com>
+ *    Ardelle Fan              <ardelle.fan@intel.com>
  *    Sridhar Samudrala        <sri@us.ibm.com>
+ *    Inaky Perez-Gonzalez     <inaky.gonzalez@intel.com>
+ *    Vlad Yasevich            <vladislav.yasevich@hp.com>
  *
  * Any bugs reported given to us we will try to fix... any fixes shared will
  * be incorporated into the next SCTP release.
  */
 
-#ifndef __net_sctp_user_h__
-#define __net_sctp_user_h__
+#ifndef _UAPI_SCTP_H
+#define _UAPI_SCTP_H
 
 #include <linux/types.h>
 #include <linux/socket.h>
@@ -165,17 +167,23 @@ enum sctp_sinfo_flags {
         SCTP_ADDR_OVER = 2,  /* Override the primary destination. */
         SCTP_ABORT=4,        /* Send an ABORT message to the peer. */
         SCTP_SACK_IMMEDIATELY = 8,      /* SACK should be sent without delay */
-        SCTP_EOF=MSG_FIN,    /* Initiate graceful shutdown process. */  
+        SCTP_EOF=MSG_FIN,    /* Initiate graceful shutdown process. */
 };
 
+typedef union {
+        __u8                    raw;
+        struct sctp_initmsg     init;
+        struct sctp_sndrcvinfo  sndrcv;
+} sctp_cmsg_data_t;
 
 /* These are cmsg_types.  */
 typedef enum sctp_cmsg_type {
         SCTP_INIT,              /* 5.2.1 SCTP Initiation Structure */
+#define SCTP_INIT       SCTP_INIT
         SCTP_SNDRCV,            /* 5.2.2 SCTP Header Information Structure */
+#define SCTP_SNDRCV     SCTP_SNDRCV
 } sctp_cmsg_t;
 
-
 /*
  * 5.3.1.1 SCTP_ASSOC_CHANGE
  *
@@ -345,6 +353,12 @@ struct sctp_pdapi_event {
 
 enum { SCTP_PARTIAL_DELIVERY_ABORTED=0, };
 
+/*
+ * 5.3.1.8.  SCTP_AUTHENTICATION_EVENT
+ *
+ *  When a receiver is using authentication this message will provide
+ *  notifications regarding new keys being made active as well as errors.
+ */
 struct sctp_authkey_event {
         __u16 auth_type;
         __u16 auth_flags;
@@ -421,15 +435,23 @@ union sctp_notification {
 enum sctp_sn_type {
         SCTP_SN_TYPE_BASE     = (1<<15),
         SCTP_ASSOC_CHANGE,
+#define SCTP_ASSOC_CHANGE               SCTP_ASSOC_CHANGE
         SCTP_PEER_ADDR_CHANGE,
+#define SCTP_PEER_ADDR_CHANGE           SCTP_PEER_ADDR_CHANGE
         SCTP_SEND_FAILED,
+#define SCTP_SEND_FAILED                SCTP_SEND_FAILED
         SCTP_REMOTE_ERROR,
+#define SCTP_REMOTE_ERROR               SCTP_REMOTE_ERROR
         SCTP_SHUTDOWN_EVENT,
+#define SCTP_SHUTDOWN_EVENT             SCTP_SHUTDOWN_EVENT
         SCTP_PARTIAL_DELIVERY_EVENT,
+#define SCTP_PARTIAL_DELIVERY_EVENT     SCTP_PARTIAL_DELIVERY_EVENT
         SCTP_ADAPTATION_INDICATION,
+#define SCTP_ADAPTATION_INDICATION      SCTP_ADAPTATION_INDICATION
         SCTP_AUTHENTICATION_EVENT,
 #define SCTP_AUTHENTICATION_INDICATION  SCTP_AUTHENTICATION_EVENT
         SCTP_SENDER_DRY_EVENT,
+#define SCTP_SENDER_DRY_EVENT           SCTP_SENDER_DRY_EVENT
 };
 
 /* Notification error codes used to fill up the error fields in some
@@ -454,7 +476,7 @@ typedef enum sctp_sn_error {
  *
  *   The protocol parameters used to initialize and bound retransmission
  *   timeout (RTO) are tunable.  See [SCTP] for more information on how
- *   these parameters are used in RTO calculation. 
+ *   these parameters are used in RTO calculation.
  */
 struct sctp_rtoinfo {
         sctp_assoc_t    srto_assoc_id;
@@ -504,6 +526,9 @@ struct sctp_prim {
         struct sockaddr_storage ssp_addr;
 } __attribute__((packed, aligned(4)));
 
+/* For backward compatibility use, define the old name too */
+#define sctp_setprim    sctp_prim
+
 /*
  * 7.1.11 Set Adaptation Layer Indicator (SCTP_ADAPTATION_LAYER)
  *
@@ -564,12 +589,27 @@ struct sctp_authchunk {
  *
  * This option gets or sets the list of HMAC algorithms that the local
  * endpoint requires the peer to use.
-*/
+ */
+#ifndef __KERNEL__
+/* This here is only used by user space as is. It might not be a good idea
+ * to export/reveal the whole structure with reserved fields etc.
+ */
+enum {
+        SCTP_AUTH_HMAC_ID_SHA1 = 1,
+        SCTP_AUTH_HMAC_ID_SHA256 = 3,
+};
+#endif
+
 struct sctp_hmacalgo {
         __u32           shmac_num_idents;
         __u16           shmac_idents[];
 };
 
+/* Sadly, user and kernel space have different names for
+ * this structure member, so this is to not break anything.
+ */
+#define shmac_number_of_idents  shmac_num_idents
+
 /*
  * 7.1.20.  Set a shared key (SCTP_AUTH_KEY)
  *
@@ -691,6 +731,24 @@ struct sctp_authchunks {
         uint8_t         gauth_chunks[];
 };
 
+/* The broken spelling has been released already in lksctp-tools header,
+ * so don't break anyone, now that it's fixed.
+ */
+#define guth_number_of_chunks   gauth_number_of_chunks
+
+/* Association states.  */
+enum sctp_sstat_state {
+        SCTP_EMPTY                = 0,
+        SCTP_CLOSED               = 1,
+        SCTP_COOKIE_WAIT          = 2,
+        SCTP_COOKIE_ECHOED        = 3,
+        SCTP_ESTABLISHED          = 4,
+        SCTP_SHUTDOWN_PENDING     = 5,
+        SCTP_SHUTDOWN_SENT        = 6,
+        SCTP_SHUTDOWN_RECEIVED    = 7,
+        SCTP_SHUTDOWN_ACK_SENT    = 8,
+};
+
 /*
  * 8.2.6. Get the Current Identifiers of Associations
  *        (SCTP_GET_ASSOC_ID_LIST)
@@ -705,15 +763,20 @@ struct sctp_assoc_ids {
 
 /*
  * 8.3, 8.5 get all peer/local addresses in an association.
- * This parameter struct is used by SCTP_GET_PEER_ADDRS and 
+ * This parameter struct is used by SCTP_GET_PEER_ADDRS and
  * SCTP_GET_LOCAL_ADDRS socket options used internally to implement
- * sctp_getpaddrs() and sctp_getladdrs() API. 
+ * sctp_getpaddrs() and sctp_getladdrs() API.
  */
 struct sctp_getaddrs_old {
         sctp_assoc_t            assoc_id;
         int                     addr_num;
+#ifdef __KERNEL__
         struct sockaddr         __user *addrs;
+#else
+        struct sockaddr         *addrs;
+#endif
 };
+
 struct sctp_getaddrs {
         sctp_assoc_t            assoc_id; /*input*/
         __u32                   addr_num; /*output*/
@@ -779,4 +842,5 @@ struct sctp_paddrthlds {
         __u16 spt_pathmaxrxt;
         __u16 spt_pathpfthld;
 };
-#endif /* __net_sctp_user_h__ */
+
+#endif /* _UAPI_SCTP_H */