Merge branch 'net-extend-drop-reasons'

Johannes Berg says:

====================
net: extend drop reasons

Here's v4 of the extended drop reasons, with fixes to kernel-doc
and checkpatch.
====================

Link: https://lore.kernel.org/r/20230419125254.20789-1-johannes@sipsolutions.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Author: kuba-moo

include/linux/netdevice.h

@@ -52,7 +52,7 @@
 #include <linux/rbtree.h>
 #include <net/net_trackers.h>
 #include <net/net_debug.h>
-#include <net/dropreason.h>
+#include <net/dropreason-core.h>
 
 struct netpoll_info;
 struct device;

include/linux/skbuff.h

@@ -37,7 +37,7 @@
 #include <linux/netfilter/nf_conntrack_common.h>
 #endif
 #include <net/net_debug.h>
-#include <net/dropreason.h>
+#include <net/dropreason-core.h>
 
 /**
  * DOC: skb checksums

include/net/dropreason-core.h

@@ -0,0 +1,370 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#ifndef _LINUX_DROPREASON_CORE_H
+#define _LINUX_DROPREASON_CORE_H
+
+#define DEFINE_DROP_REASON(FN, FNe)	\
+	FN(NOT_SPECIFIED)		\
+	FN(NO_SOCKET)			\
+	FN(PKT_TOO_SMALL)		\
+	FN(TCP_CSUM)			\
+	FN(SOCKET_FILTER)		\
+	FN(UDP_CSUM)			\
+	FN(NETFILTER_DROP)		\
+	FN(OTHERHOST)			\
+	FN(IP_CSUM)			\
+	FN(IP_INHDR)			\
+	FN(IP_RPFILTER)			\
+	FN(UNICAST_IN_L2_MULTICAST)	\
+	FN(XFRM_POLICY)			\
+	FN(IP_NOPROTO)			\
+	FN(SOCKET_RCVBUFF)		\
+	FN(PROTO_MEM)			\
+	FN(TCP_MD5NOTFOUND)		\
+	FN(TCP_MD5UNEXPECTED)		\
+	FN(TCP_MD5FAILURE)		\
+	FN(SOCKET_BACKLOG)		\
+	FN(TCP_FLAGS)			\
+	FN(TCP_ZEROWINDOW)		\
+	FN(TCP_OLD_DATA)		\
+	FN(TCP_OVERWINDOW)		\
+	FN(TCP_OFOMERGE)		\
+	FN(TCP_RFC7323_PAWS)		\
+	FN(TCP_INVALID_SEQUENCE)	\
+	FN(TCP_RESET)			\
+	FN(TCP_INVALID_SYN)		\
+	FN(TCP_CLOSE)			\
+	FN(TCP_FASTOPEN)		\
+	FN(TCP_OLD_ACK)			\
+	FN(TCP_TOO_OLD_ACK)		\
+	FN(TCP_ACK_UNSENT_DATA)		\
+	FN(TCP_OFO_QUEUE_PRUNE)		\
+	FN(TCP_OFO_DROP)		\
+	FN(IP_OUTNOROUTES)		\
+	FN(BPF_CGROUP_EGRESS)		\
+	FN(IPV6DISABLED)		\
+	FN(NEIGH_CREATEFAIL)		\
+	FN(NEIGH_FAILED)		\
+	FN(NEIGH_QUEUEFULL)		\
+	FN(NEIGH_DEAD)			\
+	FN(TC_EGRESS)			\
+	FN(QDISC_DROP)			\
+	FN(CPU_BACKLOG)			\
+	FN(XDP)				\
+	FN(TC_INGRESS)			\
+	FN(UNHANDLED_PROTO)		\
+	FN(SKB_CSUM)			\
+	FN(SKB_GSO_SEG)			\
+	FN(SKB_UCOPY_FAULT)		\
+	FN(DEV_HDR)			\
+	FN(DEV_READY)			\
+	FN(FULL_RING)			\
+	FN(NOMEM)			\
+	FN(HDR_TRUNC)			\
+	FN(TAP_FILTER)			\
+	FN(TAP_TXFILTER)		\
+	FN(ICMP_CSUM)			\
+	FN(INVALID_PROTO)		\
+	FN(IP_INADDRERRORS)		\
+	FN(IP_INNOROUTES)		\
+	FN(PKT_TOO_BIG)			\
+	FN(DUP_FRAG)			\
+	FN(FRAG_REASM_TIMEOUT)		\
+	FN(FRAG_TOO_FAR)		\
+	FN(TCP_MINTTL)			\
+	FN(IPV6_BAD_EXTHDR)		\
+	FN(IPV6_NDISC_FRAG)		\
+	FN(IPV6_NDISC_HOP_LIMIT)	\
+	FN(IPV6_NDISC_BAD_CODE)		\
+	FN(IPV6_NDISC_BAD_OPTIONS)	\
+	FN(IPV6_NDISC_NS_OTHERHOST)	\
+	FNe(MAX)
+
+/**
+ * enum skb_drop_reason - the reasons of skb drops
+ *
+ * The reason of skb drop, which is used in kfree_skb_reason().
+ */
+enum skb_drop_reason {
+	/**
+	 * @SKB_NOT_DROPPED_YET: skb is not dropped yet (used for no-drop case)
+	 */
+	SKB_NOT_DROPPED_YET = 0,
+	/** @SKB_CONSUMED: packet has been consumed */
+	SKB_CONSUMED,
+	/** @SKB_DROP_REASON_NOT_SPECIFIED: drop reason is not specified */
+	SKB_DROP_REASON_NOT_SPECIFIED,
+	/** @SKB_DROP_REASON_NO_SOCKET: socket not found */
+	SKB_DROP_REASON_NO_SOCKET,
+	/** @SKB_DROP_REASON_PKT_TOO_SMALL: packet size is too small */
+	SKB_DROP_REASON_PKT_TOO_SMALL,
+	/** @SKB_DROP_REASON_TCP_CSUM: TCP checksum error */
+	SKB_DROP_REASON_TCP_CSUM,
+	/** @SKB_DROP_REASON_SOCKET_FILTER: dropped by socket filter */
+	SKB_DROP_REASON_SOCKET_FILTER,
+	/** @SKB_DROP_REASON_UDP_CSUM: UDP checksum error */
+	SKB_DROP_REASON_UDP_CSUM,
+	/** @SKB_DROP_REASON_NETFILTER_DROP: dropped by netfilter */
+	SKB_DROP_REASON_NETFILTER_DROP,
+	/**
+	 * @SKB_DROP_REASON_OTHERHOST: packet don't belong to current host
+	 * (interface is in promisc mode)
+	 */
+	SKB_DROP_REASON_OTHERHOST,
+	/** @SKB_DROP_REASON_IP_CSUM: IP checksum error */
+	SKB_DROP_REASON_IP_CSUM,
+	/**
+	 * @SKB_DROP_REASON_IP_INHDR: there is something wrong with IP header (see
+	 * IPSTATS_MIB_INHDRERRORS)
+	 */
+	SKB_DROP_REASON_IP_INHDR,
+	/**
+	 * @SKB_DROP_REASON_IP_RPFILTER: IP rpfilter validate failed. see the
+	 * document for rp_filter in ip-sysctl.rst for more information
+	 */
+	SKB_DROP_REASON_IP_RPFILTER,
+	/**
+	 * @SKB_DROP_REASON_UNICAST_IN_L2_MULTICAST: destination address of L2 is
+	 * multicast, but L3 is unicast.
+	 */
+	SKB_DROP_REASON_UNICAST_IN_L2_MULTICAST,
+	/** @SKB_DROP_REASON_XFRM_POLICY: xfrm policy check failed */
+	SKB_DROP_REASON_XFRM_POLICY,
+	/** @SKB_DROP_REASON_IP_NOPROTO: no support for IP protocol */
+	SKB_DROP_REASON_IP_NOPROTO,
+	/** @SKB_DROP_REASON_SOCKET_RCVBUFF: socket receive buff is full */
+	SKB_DROP_REASON_SOCKET_RCVBUFF,
+	/**
+	 * @SKB_DROP_REASON_PROTO_MEM: proto memory limition, such as udp packet
+	 * drop out of udp_memory_allocated.
+	 */
+	SKB_DROP_REASON_PROTO_MEM,
+	/**
+	 * @SKB_DROP_REASON_TCP_MD5NOTFOUND: no MD5 hash and one expected,
+	 * corresponding to LINUX_MIB_TCPMD5NOTFOUND
+	 */
+	SKB_DROP_REASON_TCP_MD5NOTFOUND,
+	/**
+	 * @SKB_DROP_REASON_TCP_MD5UNEXPECTED: MD5 hash and we're not expecting
+	 * one, corresponding to LINUX_MIB_TCPMD5UNEXPECTED
+	 */
+	SKB_DROP_REASON_TCP_MD5UNEXPECTED,
+	/**
+	 * @SKB_DROP_REASON_TCP_MD5FAILURE: MD5 hash and its wrong, corresponding
+	 * to LINUX_MIB_TCPMD5FAILURE
+	 */
+	SKB_DROP_REASON_TCP_MD5FAILURE,
+	/**
+	 * @SKB_DROP_REASON_SOCKET_BACKLOG: failed to add skb to socket backlog (
+	 * see LINUX_MIB_TCPBACKLOGDROP)
+	 */
+	SKB_DROP_REASON_SOCKET_BACKLOG,
+	/** @SKB_DROP_REASON_TCP_FLAGS: TCP flags invalid */
+	SKB_DROP_REASON_TCP_FLAGS,
+	/**
+	 * @SKB_DROP_REASON_TCP_ZEROWINDOW: TCP receive window size is zero,
+	 * see LINUX_MIB_TCPZEROWINDOWDROP
+	 */
+	SKB_DROP_REASON_TCP_ZEROWINDOW,
+	/**
+	 * @SKB_DROP_REASON_TCP_OLD_DATA: the TCP data reveived is already
+	 * received before (spurious retrans may happened), see
+	 * LINUX_MIB_DELAYEDACKLOST
+	 */
+	SKB_DROP_REASON_TCP_OLD_DATA,
+	/**
+	 * @SKB_DROP_REASON_TCP_OVERWINDOW: the TCP data is out of window,
+	 * the seq of the first byte exceed the right edges of receive
+	 * window
+	 */
+	SKB_DROP_REASON_TCP_OVERWINDOW,
+	/**
+	 * @SKB_DROP_REASON_TCP_OFOMERGE: the data of skb is already in the ofo
+	 * queue, corresponding to LINUX_MIB_TCPOFOMERGE
+	 */
+	SKB_DROP_REASON_TCP_OFOMERGE,
+	/**
+	 * @SKB_DROP_REASON_TCP_RFC7323_PAWS: PAWS check, corresponding to
+	 * LINUX_MIB_PAWSESTABREJECTED
+	 */
+	SKB_DROP_REASON_TCP_RFC7323_PAWS,
+	/** @SKB_DROP_REASON_TCP_INVALID_SEQUENCE: Not acceptable SEQ field */
+	SKB_DROP_REASON_TCP_INVALID_SEQUENCE,
+	/** @SKB_DROP_REASON_TCP_RESET: Invalid RST packet */
+	SKB_DROP_REASON_TCP_RESET,
+	/**
+	 * @SKB_DROP_REASON_TCP_INVALID_SYN: Incoming packet has unexpected
+	 * SYN flag
+	 */
+	SKB_DROP_REASON_TCP_INVALID_SYN,
+	/** @SKB_DROP_REASON_TCP_CLOSE: TCP socket in CLOSE state */
+	SKB_DROP_REASON_TCP_CLOSE,
+	/** @SKB_DROP_REASON_TCP_FASTOPEN: dropped by FASTOPEN request socket */
+	SKB_DROP_REASON_TCP_FASTOPEN,
+	/** @SKB_DROP_REASON_TCP_OLD_ACK: TCP ACK is old, but in window */
+	SKB_DROP_REASON_TCP_OLD_ACK,
+	/** @SKB_DROP_REASON_TCP_TOO_OLD_ACK: TCP ACK is too old */
+	SKB_DROP_REASON_TCP_TOO_OLD_ACK,
+	/**
+	 * @SKB_DROP_REASON_TCP_ACK_UNSENT_DATA: TCP ACK for data we haven't
+	 * sent yet
+	 */
+	SKB_DROP_REASON_TCP_ACK_UNSENT_DATA,
+	/** @SKB_DROP_REASON_TCP_OFO_QUEUE_PRUNE: pruned from TCP OFO queue */
+	SKB_DROP_REASON_TCP_OFO_QUEUE_PRUNE,
+	/** @SKB_DROP_REASON_TCP_OFO_DROP: data already in receive queue */
+	SKB_DROP_REASON_TCP_OFO_DROP,
+	/** @SKB_DROP_REASON_IP_OUTNOROUTES: route lookup failed */
+	SKB_DROP_REASON_IP_OUTNOROUTES,
+	/**
+	 * @SKB_DROP_REASON_BPF_CGROUP_EGRESS: dropped by BPF_PROG_TYPE_CGROUP_SKB
+	 * eBPF program
+	 */
+	SKB_DROP_REASON_BPF_CGROUP_EGRESS,
+	/** @SKB_DROP_REASON_IPV6DISABLED: IPv6 is disabled on the device */
+	SKB_DROP_REASON_IPV6DISABLED,
+	/** @SKB_DROP_REASON_NEIGH_CREATEFAIL: failed to create neigh entry */
+	SKB_DROP_REASON_NEIGH_CREATEFAIL,
+	/** @SKB_DROP_REASON_NEIGH_FAILED: neigh entry in failed state */
+	SKB_DROP_REASON_NEIGH_FAILED,
+	/** @SKB_DROP_REASON_NEIGH_QUEUEFULL: arp_queue for neigh entry is full */
+	SKB_DROP_REASON_NEIGH_QUEUEFULL,
+	/** @SKB_DROP_REASON_NEIGH_DEAD: neigh entry is dead */
+	SKB_DROP_REASON_NEIGH_DEAD,
+	/** @SKB_DROP_REASON_TC_EGRESS: dropped in TC egress HOOK */
+	SKB_DROP_REASON_TC_EGRESS,
+	/**
+	 * @SKB_DROP_REASON_QDISC_DROP: dropped by qdisc when packet outputting (
+	 * failed to enqueue to current qdisc)
+	 */
+	SKB_DROP_REASON_QDISC_DROP,
+	/**
+	 * @SKB_DROP_REASON_CPU_BACKLOG: failed to enqueue the skb to the per CPU
+	 * backlog queue. This can be caused by backlog queue full (see
+	 * netdev_max_backlog in net.rst) or RPS flow limit
+	 */
+	SKB_DROP_REASON_CPU_BACKLOG,
+	/** @SKB_DROP_REASON_XDP: dropped by XDP in input path */
+	SKB_DROP_REASON_XDP,
+	/** @SKB_DROP_REASON_TC_INGRESS: dropped in TC ingress HOOK */
+	SKB_DROP_REASON_TC_INGRESS,
+	/** @SKB_DROP_REASON_UNHANDLED_PROTO: protocol not implemented or not supported */
+	SKB_DROP_REASON_UNHANDLED_PROTO,
+	/** @SKB_DROP_REASON_SKB_CSUM: sk_buff checksum computation error */
+	SKB_DROP_REASON_SKB_CSUM,
+	/** @SKB_DROP_REASON_SKB_GSO_SEG: gso segmentation error */
+	SKB_DROP_REASON_SKB_GSO_SEG,
+	/**
+	 * @SKB_DROP_REASON_SKB_UCOPY_FAULT: failed to copy data from user space,
+	 * e.g., via zerocopy_sg_from_iter() or skb_orphan_frags_rx()
+	 */
+	SKB_DROP_REASON_SKB_UCOPY_FAULT,
+	/** @SKB_DROP_REASON_DEV_HDR: device driver specific header/metadata is invalid */
+	SKB_DROP_REASON_DEV_HDR,
+	/**
+	 * @SKB_DROP_REASON_DEV_READY: the device is not ready to xmit/recv due to
+	 * any of its data structure that is not up/ready/initialized,
+	 * e.g., the IFF_UP is not set, or driver specific tun->tfiles[txq]
+	 * is not initialized
+	 */
+	SKB_DROP_REASON_DEV_READY,
+	/** @SKB_DROP_REASON_FULL_RING: ring buffer is full */
+	SKB_DROP_REASON_FULL_RING,
+	/** @SKB_DROP_REASON_NOMEM: error due to OOM */
+	SKB_DROP_REASON_NOMEM,
+	/**
+	 * @SKB_DROP_REASON_HDR_TRUNC: failed to trunc/extract the header from
+	 * networking data, e.g., failed to pull the protocol header from
+	 * frags via pskb_may_pull()
+	 */
+	SKB_DROP_REASON_HDR_TRUNC,
+	/**
+	 * @SKB_DROP_REASON_TAP_FILTER: dropped by (ebpf) filter directly attached
+	 * to tun/tap, e.g., via TUNSETFILTEREBPF
+	 */
+	SKB_DROP_REASON_TAP_FILTER,
+	/**
+	 * @SKB_DROP_REASON_TAP_TXFILTER: dropped by tx filter implemented at
+	 * tun/tap, e.g., check_filter()
+	 */
+	SKB_DROP_REASON_TAP_TXFILTER,
+	/** @SKB_DROP_REASON_ICMP_CSUM: ICMP checksum error */
+	SKB_DROP_REASON_ICMP_CSUM,
+	/**
+	 * @SKB_DROP_REASON_INVALID_PROTO: the packet doesn't follow RFC 2211,
+	 * such as a broadcasts ICMP_TIMESTAMP
+	 */
+	SKB_DROP_REASON_INVALID_PROTO,
+	/**
+	 * @SKB_DROP_REASON_IP_INADDRERRORS: host unreachable, corresponding to
+	 * IPSTATS_MIB_INADDRERRORS
+	 */
+	SKB_DROP_REASON_IP_INADDRERRORS,
+	/**
+	 * @SKB_DROP_REASON_IP_INNOROUTES: network unreachable, corresponding to
+	 * IPSTATS_MIB_INADDRERRORS
+	 */
+	SKB_DROP_REASON_IP_INNOROUTES,
+	/**
+	 * @SKB_DROP_REASON_PKT_TOO_BIG: packet size is too big (maybe exceed the
+	 * MTU)
+	 */
+	SKB_DROP_REASON_PKT_TOO_BIG,
+	/** @SKB_DROP_REASON_DUP_FRAG: duplicate fragment */
+	SKB_DROP_REASON_DUP_FRAG,
+	/** @SKB_DROP_REASON_FRAG_REASM_TIMEOUT: fragment reassembly timeout */
+	SKB_DROP_REASON_FRAG_REASM_TIMEOUT,
+	/**
+	 * @SKB_DROP_REASON_FRAG_TOO_FAR: ipv4 fragment too far.
+	 * (/proc/sys/net/ipv4/ipfrag_max_dist)
+	 */
+	SKB_DROP_REASON_FRAG_TOO_FAR,
+	/**
+	 * @SKB_DROP_REASON_TCP_MINTTL: ipv4 ttl or ipv6 hoplimit below
+	 * the threshold (IP_MINTTL or IPV6_MINHOPCOUNT).
+	 */
+	SKB_DROP_REASON_TCP_MINTTL,
+	/** @SKB_DROP_REASON_IPV6_BAD_EXTHDR: Bad IPv6 extension header. */
+	SKB_DROP_REASON_IPV6_BAD_EXTHDR,
+	/** @SKB_DROP_REASON_IPV6_NDISC_FRAG: invalid frag (suppress_frag_ndisc). */
+	SKB_DROP_REASON_IPV6_NDISC_FRAG,
+	/** @SKB_DROP_REASON_IPV6_NDISC_HOP_LIMIT: invalid hop limit. */
+	SKB_DROP_REASON_IPV6_NDISC_HOP_LIMIT,
+	/** @SKB_DROP_REASON_IPV6_NDISC_BAD_CODE: invalid NDISC icmp6 code. */
+	SKB_DROP_REASON_IPV6_NDISC_BAD_CODE,
+	/** @SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS: invalid NDISC options. */
+	SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS,
+	/**
+	 * @SKB_DROP_REASON_IPV6_NDISC_NS_OTHERHOST: NEIGHBOUR SOLICITATION
+	 * for another host.
+	 */
+	SKB_DROP_REASON_IPV6_NDISC_NS_OTHERHOST,
+	/**
+	 * @SKB_DROP_REASON_MAX: the maximum of core drop reasons, which
+	 * shouldn't be used as a real 'reason' - only for tracing code gen
+	 */
+	SKB_DROP_REASON_MAX,
+
+	/**
+	 * @SKB_DROP_REASON_SUBSYS_MASK: subsystem mask in drop reasons,
+	 * see &enum skb_drop_reason_subsys
+	 */
+	SKB_DROP_REASON_SUBSYS_MASK = 0xffff0000,
+};
+
+#define SKB_DROP_REASON_SUBSYS_SHIFT	16
+
+#define SKB_DR_INIT(name, reason)				\
+	enum skb_drop_reason name = SKB_DROP_REASON_##reason
+#define SKB_DR(name)						\
+	SKB_DR_INIT(name, NOT_SPECIFIED)
+#define SKB_DR_SET(name, reason)				\
+	(name = SKB_DROP_REASON_##reason)
+#define SKB_DR_OR(name, reason)					\
+	do {							\
+		if (name == SKB_DROP_REASON_NOT_SPECIFIED ||	\
+		    name == SKB_NOT_DROPPED_YET)		\
+			SKB_DR_SET(name, reason);		\
+	} while (0)
+
+#endif