Merge branch 'mctp'

Jeremy Kerr says:

====================
Add Management Component Transport Protocol support

This series adds core MCTP support to the kernel. From the Kconfig
description:

  Management Component Transport Protocol (MCTP) is an in-system
  protocol for communicating between management controllers and
  their managed devices (peripherals, host processors, etc.). The
  protocol is defined by DMTF specification DSP0236.

  This option enables core MCTP support. For communicating with other
  devices, you'll want to enable a driver for a specific hardware
  channel.

This implementation allows a sockets-based API for sending and receiving
MCTP messages via sendmsg/recvmsg on SOCK_DGRAM sockets. Kernel stack
control is all via netlink, using existing RTM_* messages. The userspace
ABI change is fairly small; just the necessary AF_/ETH_P_/ARPHDR_
constants, a new sockaddr, and a new netlink attribute.

For MAINTAINERS, I've just included netdev@ as the list entry. I'm happy
to alter this based on preferences here - an alternative would be the
OpenBMC list (the main user of the MCTP interface), or we can create a
new list entirely.

We have a couple of interface drivers almost ready to go at the moment,
but those can wait until the core code has some review.

This is v4 of the series; v1 and v2 were both RFC.

selinux folks: CCing 01/15 due to the new PF_MCTP protocol family.

linux-doc folks: CCing 15/15 for the new MCTP overview document.

Review, comments, questions etc. are most welcome.

Cheers,

Jeremy

v2:
 - change to match spec terminology: controller -> component
 - require specific capabilities for bind() & sendmsg()
 - add address and tag defintions to uapi
 - add selinux AF_MCTP table definitions
 - remove strict cflags; warnings are present in common headers

v3:
 - require caps for MCTP bind() & send()
 - comment typo fixes
 - switch to an array for local EIDs
 - fix addrinfo dump iteration & error path
 - add RTM_DELADDR
 - remove GENMASK() and BIT() from uapi

v4:
 - drop tun patch; that can be submitted separately
 - keep nipa happy: add maintainer CCs, including doc and selinux
 - net-next rebase
 - Include AF_MCTP in af_family_slock_keys and pf_family_names
 - Introduce MODULE_ definitions earlier
 - upstream change: set_link_af no longer called with RTNL held
 - add kdoc for net_device.mctp_ptr
 - don't inline mctp_rt_match_eid
 - require rtm_type == RTN_UNICAST in route management handlers
 - remove unused RTAX policy table
 - fix mctp_sock->keys rcu annotations
 - fix spurious rcu_read_unlock in route input
====================

Signed-off-by: David S. Miller <[email protected]>

4 files changed, 50 insertions, 0 deletions

diff --git a/include/uapi/linux/if_arp.h b/include/uapi/linux/if_arp.h
index c3cc5a9e5eaf..4783af9fe520 100644
--- a/include/uapi/linux/if_arp.h
+++ b/include/uapi/linux/if_arp.h
@@ -54,6 +54,7 @@
 #define ARPHRD_X25	271		/* CCITT X.25			*/
 #define ARPHRD_HWX25	272		/* Boards with X.25 in firmware	*/
 #define ARPHRD_CAN	280		/* Controller Area Network      */
+#define ARPHRD_MCTP	290
 #define ARPHRD_PPP	512
 #define ARPHRD_CISCO	513		/* Cisco HDLC	 		*/
 #define ARPHRD_HDLC	ARPHRD_CISCO
diff --git a/include/uapi/linux/if_ether.h b/include/uapi/linux/if_ether.h
index a0b637911d3c..5f589c7a8382 100644
--- a/include/uapi/linux/if_ether.h
+++ b/include/uapi/linux/if_ether.h
@@ -151,6 +151,9 @@
 #define ETH_P_MAP	0x00F9		/* Qualcomm multiplexing and
 					 * aggregation protocol
 					 */
+#define ETH_P_MCTP	0x00FA		/* Management component transport
+					 * protocol packets
+					 */
 
 /*
  *	This is an Ethernet frame header.
diff --git a/include/uapi/linux/if_link.h b/include/uapi/linux/if_link.h
index 4882e81514b6..49b22afab78f 100644
--- a/include/uapi/linux/if_link.h
+++ b/include/uapi/linux/if_link.h
@@ -1260,4 +1260,14 @@ struct ifla_rmnet_flags {
 	__u32	mask;
 };
 
+/* MCTP section */
+
+enum {
+	IFLA_MCTP_UNSPEC,
+	IFLA_MCTP_NET,
+	__IFLA_MCTP_MAX,
+};
+
+#define IFLA_MCTP_MAX (__IFLA_MCTP_MAX - 1)
+
 #endif /* _UAPI_LINUX_IF_LINK_H */
diff --git a/include/uapi/linux/mctp.h b/include/uapi/linux/mctp.h
new file mode 100644
index 000000000000..52b54d13f385
--- /dev/null
+++ b/include/uapi/linux/mctp.h
@@ -0,0 +1,36 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+/*
+ * Management Component Transport Protocol (MCTP)
+ *
+ * Copyright (c) 2021 Code Construct
+ * Copyright (c) 2021 Google
+ */
+
+#ifndef __UAPI_MCTP_H
+#define __UAPI_MCTP_H
+
+#include <linux/types.h>
+
+typedef __u8			mctp_eid_t;
+
+struct mctp_addr {
+	mctp_eid_t		s_addr;
+};
+
+struct sockaddr_mctp {
+	unsigned short int	smctp_family;
+	int			smctp_network;
+	struct mctp_addr	smctp_addr;
+	__u8			smctp_type;
+	__u8			smctp_tag;
+};
+
+#define MCTP_NET_ANY		0x0
+
+#define MCTP_ADDR_NULL		0x00
+#define MCTP_ADDR_ANY		0xff
+
+#define MCTP_TAG_MASK		0x07
+#define MCTP_TAG_OWNER		0x08
+
+#endif /* __UAPI_MCTP_H */