Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextgrafted

Pull networking updates from Jakub Kicinski:
 "Core:

   - Add dedicated kmem_cache for typical/small skb->head, avoid having
     to access struct page at kfree time, and improve memory use.

   - Introduce sysctl to set default RPS configuration for new netdevs.

   - Define Netlink protocol specification format which can be used to
     describe messages used by each family and auto-generate parsers.
     Add tools for generating kernel data structures and uAPI headers.

   - Expose all net/core sysctls inside netns.

   - Remove 4s sleep in netpoll if carrier is instantly detected on
     boot.

   - Add configurable limit of MDB entries per port, and port-vlan.

   - Continue populating drop reasons throughout the stack.

   - Retire a handful of legacy Qdiscs and classifiers.

  Protocols:

   - Support IPv4 big TCP (TSO frames larger than 64kB).

   - Add IP_LOCAL_PORT_RANGE socket option, to control local port range
     on socket by socket basis.

   - Track and report in procfs number of MPTCP sockets used.

   - Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path
     manager.

   - IPv6: don't check net.ipv6.route.max_size and rely on garbage
     collection to free memory (similarly to IPv4).

   - Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986).

   - ICMP: add per-rate limit counters.

   - Add support for user scanning requests in ieee802154.

   - Remove static WEP support.

   - Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate
     reporting.

   - WiFi 7 EHT channel puncturing support (client & AP).

  BPF:

   - Add a rbtree data structure following the "next-gen data structure"
     precedent set by recently added linked list, that is, by using
     kfunc + kptr instead of adding a new BPF map type.

   - Expose XDP hints via kfuncs with initial support for RX hash and
     timestamp metadata.

   - Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to
     better support decap on GRE tunnel devices not operating in collect
     metadata.

   - Improve x86 JIT's codegen for PROBE_MEM runtime error checks.

   - Remove the need for trace_printk_lock for bpf_trace_printk and
     bpf_trace_vprintk helpers.

   - Extend libbpf's bpf_tracing.h support for tracing arguments of
     kprobes/uprobes and syscall as a special case.

   - Significantly reduce the search time for module symbols by
     livepatch and BPF.

   - Enable cpumasks to be used as kptrs, which is useful for tracing
     programs tracking which tasks end up running on which CPUs in
     different time intervals.

   - Add support for BPF trampoline on s390x and riscv64.

   - Add capability to export the XDP features supported by the NIC.

   - Add __bpf_kfunc tag for marking kernel functions as kfuncs.

   - Add cgroup.memory=nobpf kernel parameter option to disable BPF
     memory accounting for container environments.

  Netfilter:

   - Remove the CLUSTERIP target. It has been marked as obsolete for
     years, and we still have WARN splats wrt races of the out-of-band
     /proc interface installed by this target.

   - Add 'destroy' commands to nf_tables. They are identical to the
     existing 'delete' commands, but do not return an error if the
     referenced object (set, chain, rule...) did not exist.

  Driver API:

   - Improve cpumask_local_spread() locality to help NICs set the right
     IRQ affinity on AMD platforms.

   - Separate C22 and C45 MDIO bus transactions more clearly.

   - Introduce new DCB table to control DSCP rewrite on egress.

   - Support configuration of Physical Layer Collision Avoidance (PLCA)
     Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of
     shared medium Ethernet.

   - Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing
     preemption of low priority frames by high priority frames.

   - Add support for controlling MACSec offload using netlink SET.

   - Rework devlink instance refcounts to allow registration and
     de-registration under the instance lock. Split the code into
     multiple files, drop some of the unnecessarily granular locks and
     factor out common parts of netlink operation handling.

   - Add TX frame aggregation parameters (for USB drivers).

   - Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning
     messages with notifications for debug.

   - Allow offloading of UDP NEW connections via act_ct.

   - Add support for per action HW stats in TC.

   - Support hardware miss to TC action (continue processing in SW from
     a specific point in the action chain).

   - Warn if old Wireless Extension user space interface is used with
     modern cfg80211/mac80211 drivers. Do not support Wireless
     Extensions for Wi-Fi 7 devices at all. Everyone should switch to
     using nl80211 interface instead.

   - Improve the CAN bit timing configuration. Use extack to return
     error messages directly to user space, update the SJW handling,
     including the definition of a new default value that will benefit
     CAN-FD controllers, by increasing their oscillator tolerance.

  New hardware / drivers:

   - Ethernet:
      - nVidia BlueField-3 support (control traffic driver)
      - Ethernet support for imx93 SoCs
      - Motorcomm yt8531 gigabit Ethernet PHY
      - onsemi NCN26000 10BASE-T1S PHY (with support for PLCA)
      - Microchip LAN8841 PHY (incl. cable diagnostics and PTP)
      - Amlogic gxl MDIO mux

   - WiFi:
      - RealTek RTL8188EU (rtl8xxxu)
      - Qualcomm Wi-Fi 7 devices (ath12k)

   - CAN:
      - Renesas R-Car V4H

  Drivers:

   - Bluetooth:
      - Set Per Platform Antenna Gain (PPAG) for Intel controllers.

   - Ethernet NICs:
      - Intel (1G, igc):
         - support TSN / Qbv / packet scheduling features of i226 model
      - Intel (100G, ice):
         - use GNSS subsystem instead of TTY
         - multi-buffer XDP support
         - extend support for GPIO pins to E823 devices
      - nVidia/Mellanox:
         - update the shared buffer configuration on PFC commands
         - implement PTP adjphase function for HW offset control
         - TC support for Geneve and GRE with VF tunnel offload
         - more efficient crypto key management method
         - multi-port eswitch support
      - Netronome/Corigine:
         - add DCB IEEE support
         - support IPsec offloading for NFP3800
      - Freescale/NXP (enetc):
         - support XDP_REDIRECT for XDP non-linear buffers
         - improve reconfig, avoid link flap and waiting for idle
         - support MAC Merge layer
      - Other NICs:
         - sfc/ef100: add basic devlink support for ef100
         - ionic: rx_push mode operation (writing descriptors via MMIO)
         - bnxt: use the auxiliary bus abstraction for RDMA
         - r8169: disable ASPM and reset bus in case of tx timeout
         - cpsw: support QSGMII mode for J721e CPSW9G
         - cpts: support pulse-per-second output
         - ngbe: add an mdio bus driver
         - usbnet: optimize usbnet_bh() by avoiding unnecessary queuing
         - r8152: handle devices with FW with NCM support
         - amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation
         - virtio-net: support multi buffer XDP
         - virtio/vsock: replace virtio_vsock_pkt with sk_buff
         - tsnep: XDP support

   - Ethernet high-speed switches:
      - nVidia/Mellanox (mlxsw):
         - add support for latency TLV (in FW control messages)
      - Microchip (sparx5):
         - separate explicit and implicit traffic forwarding rules, make
           the implicit rules always active
         - add support for egress DSCP rewrite
         - IS0 VCAP support (Ingress Classification)
         - IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS
           etc.)
         - ES2 VCAP support (Egress Access Control)
         - support for Per-Stream Filtering and Policing (802.1Q,
           8.6.5.1)

   - Ethernet embedded switches:
      - Marvell (mv88e6xxx):
         - add MAB (port auth) offload support
         - enable PTP receive for mv88e6390
      - NXP (ocelot):
         - support MAC Merge layer
         - support for the the vsc7512 internal copper phys
      - Microchip:
         - lan9303: convert to PHYLINK
         - lan966x: support TC flower filter statistics
         - lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x
         - lan937x: support Credit Based Shaper configuration
         - ksz9477: support Energy Efficient Ethernet
      - other:
         - qca8k: convert to regmap read/write API, use bulk operations
         - rswitch: Improve TX timestamp accuracy

   - Intel WiFi (iwlwifi):
      - EHT (Wi-Fi 7) rate reporting
      - STEP equalizer support: transfer some STEP (connection to radio
        on platforms with integrated wifi) related parameters from the
        BIOS to the firmware.

   - Qualcomm 802.11ax WiFi (ath11k):
      - IPQ5018 support
      - Fine Timing Measurement (FTM) responder role support
      - channel 177 support

   - MediaTek WiFi (mt76):
      - per-PHY LED support
      - mt7996: EHT (Wi-Fi 7) support
      - Wireless Ethernet Dispatch (WED) reset support
      - switch to using page pool allocator

   - RealTek WiFi (rtw89):
      - support new version of Bluetooth co-existance

   - Mobile:
      - rmnet: support TX aggregation"

* tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits)
  page_pool: add a comment explaining the fragment counter usage
  net: ethtool: fix __ethtool_dev_mm_supported() implementation
  ethtool: pse-pd: Fix double word in comments
  xsk: add linux/vmalloc.h to xsk.c
  sefltests: netdevsim: wait for devlink instance after netns removal
  selftest: fib_tests: Always cleanup before exit
  net/mlx5e: Align IPsec ASO result memory to be as required by hardware
  net/mlx5e: TC, Set CT miss to the specific ct action instance
  net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG
  net/mlx5: Refactor tc miss handling to a single function
  net/mlx5: Kconfig: Make tc offload depend on tc skb extension
  net/sched: flower: Support hardware miss to tc action
  net/sched: flower: Move filter handle initialization earlier
  net/sched: cls_api: Support hardware miss to tc action
  net/sched: Rename user cookie and act cookie
  sfc: fix builds without CONFIG_RTC_LIB
  sfc: clean up some inconsistent indentings
  net/mlx4_en: Introduce flexible array to silence overflow warning
  net: lan966x: Fix possible deadlock inside PTP
  net/ulp: Remove redundant ->clone() test in inet_clone_ulp().
  ...

1 files changed, 486 insertions, 0 deletions

diff --git a/net/core/utils.c b/net/core/utils.c
new file mode 100644
index 000000000..c994e9517
--- /dev/null
+++ b/net/core/utils.c
@@ -0,0 +1,486 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *	Generic address resultion entity
+ *
+ *	Authors:
+ *	net_random Alan Cox
+ *	net_ratelimit Andi Kleen
+ *	in{4,6}_pton YOSHIFUJI Hideaki, Copyright (C)2006 USAGI/WIDE Project
+ *
+ *	Created by Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
+ */
+
+#include <linux/module.h>
+#include <linux/jiffies.h>
+#include <linux/kernel.h>
+#include <linux/ctype.h>
+#include <linux/inet.h>
+#include <linux/mm.h>
+#include <linux/net.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/percpu.h>
+#include <linux/init.h>
+#include <linux/ratelimit.h>
+#include <linux/socket.h>
+
+#include <net/sock.h>
+#include <net/net_ratelimit.h>
+#include <net/ipv6.h>
+
+#include <asm/byteorder.h>
+#include <linux/uaccess.h>
+
+DEFINE_RATELIMIT_STATE(net_ratelimit_state, 5 * HZ, 10);
+/*
+ * All net warning printk()s should be guarded by this function.
+ */
+int net_ratelimit(void)
+{
+	return __ratelimit(&net_ratelimit_state);
+}
+EXPORT_SYMBOL(net_ratelimit);
+
+/*
+ * Convert an ASCII string to binary IP.
+ * This is outside of net/ipv4/ because various code that uses IP addresses
+ * is otherwise not dependent on the TCP/IP stack.
+ */
+
+__be32 in_aton(const char *str)
+{
+	unsigned int l;
+	unsigned int val;
+	int i;
+
+	l = 0;
+	for (i = 0; i < 4; i++)	{
+		l <<= 8;
+		if (*str != '\0') {
+			val = 0;
+			while (*str != '\0' && *str != '.' && *str != '\n') {
+				val *= 10;
+				val += *str - '0';
+				str++;
+			}
+			l |= val;
+			if (*str != '\0')
+				str++;
+		}
+	}
+	return htonl(l);
+}
+EXPORT_SYMBOL(in_aton);
+
+#define IN6PTON_XDIGIT		0x00010000
+#define IN6PTON_DIGIT		0x00020000
+#define IN6PTON_COLON_MASK	0x00700000
+#define IN6PTON_COLON_1		0x00100000	/* single : requested */
+#define IN6PTON_COLON_2		0x00200000	/* second : requested */
+#define IN6PTON_COLON_1_2	0x00400000	/* :: requested */
+#define IN6PTON_DOT		0x00800000	/* . */
+#define IN6PTON_DELIM		0x10000000
+#define IN6PTON_NULL		0x20000000	/* first/tail */
+#define IN6PTON_UNKNOWN		0x40000000
+
+static inline int xdigit2bin(char c, int delim)
+{
+	int val;
+
+	if (c == delim || c == '\0')
+		return IN6PTON_DELIM;
+	if (c == ':')
+		return IN6PTON_COLON_MASK;
+	if (c == '.')
+		return IN6PTON_DOT;
+
+	val = hex_to_bin(c);
+	if (val >= 0)
+		return val | IN6PTON_XDIGIT | (val < 10 ? IN6PTON_DIGIT : 0);
+
+	if (delim == -1)
+		return IN6PTON_DELIM;
+	return IN6PTON_UNKNOWN;
+}
+
+/**
+ * in4_pton - convert an IPv4 address from literal to binary representation
+ * @src: the start of the IPv4 address string
+ * @srclen: the length of the string, -1 means strlen(src)
+ * @dst: the binary (u8[4] array) representation of the IPv4 address
+ * @delim: the delimiter of the IPv4 address in @src, -1 means no delimiter
+ * @end: A pointer to the end of the parsed string will be placed here
+ *
+ * Return one on success, return zero when any error occurs
+ * and @end will point to the end of the parsed string.
+ *
+ */
+int in4_pton(const char *src, int srclen,
+	     u8 *dst,
+	     int delim, const char **end)
+{
+	const char *s;
+	u8 *d;
+	u8 dbuf[4];
+	int ret = 0;
+	int i;
+	int w = 0;
+
+	if (srclen < 0)
+		srclen = strlen(src);
+	s = src;
+	d = dbuf;
+	i = 0;
+	while (1) {
+		int c;
+		c = xdigit2bin(srclen > 0 ? *s : '\0', delim);
+		if (!(c & (IN6PTON_DIGIT | IN6PTON_DOT | IN6PTON_DELIM | IN6PTON_COLON_MASK))) {
+			goto out;
+		}
+		if (c & (IN6PTON_DOT | IN6PTON_DELIM | IN6PTON_COLON_MASK)) {
+			if (w == 0)
+				goto out;
+			*d++ = w & 0xff;
+			w = 0;
+			i++;
+			if (c & (IN6PTON_DELIM | IN6PTON_COLON_MASK)) {
+				if (i != 4)
+					goto out;
+				break;
+			}
+			goto cont;
+		}
+		w = (w * 10) + c;
+		if ((w & 0xffff) > 255) {
+			goto out;
+		}
+cont:
+		if (i >= 4)
+			goto out;
+		s++;
+		srclen--;
+	}
+	ret = 1;
+	memcpy(dst, dbuf, sizeof(dbuf));
+out:
+	if (end)
+		*end = s;
+	return ret;
+}
+EXPORT_SYMBOL(in4_pton);
+
+/**
+ * in6_pton - convert an IPv6 address from literal to binary representation
+ * @src: the start of the IPv6 address string
+ * @srclen: the length of the string, -1 means strlen(src)
+ * @dst: the binary (u8[16] array) representation of the IPv6 address
+ * @delim: the delimiter of the IPv6 address in @src, -1 means no delimiter
+ * @end: A pointer to the end of the parsed string will be placed here
+ *
+ * Return one on success, return zero when any error occurs
+ * and @end will point to the end of the parsed string.
+ *
+ */
+int in6_pton(const char *src, int srclen,
+	     u8 *dst,
+	     int delim, const char **end)
+{
+	const char *s, *tok = NULL;
+	u8 *d, *dc = NULL;
+	u8 dbuf[16];
+	int ret = 0;
+	int i;
+	int state = IN6PTON_COLON_1_2 | IN6PTON_XDIGIT | IN6PTON_NULL;
+	int w = 0;
+
+	memset(dbuf, 0, sizeof(dbuf));
+
+	s = src;
+	d = dbuf;
+	if (srclen < 0)
+		srclen = strlen(src);
+
+	while (1) {
+		int c;
+
+		c = xdigit2bin(srclen > 0 ? *s : '\0', delim);
+		if (!(c & state))
+			goto out;
+		if (c & (IN6PTON_DELIM | IN6PTON_COLON_MASK)) {
+			/* process one 16-bit word */
+			if (!(state & IN6PTON_NULL)) {
+				*d++ = (w >> 8) & 0xff;
+				*d++ = w & 0xff;
+			}
+			w = 0;
+			if (c & IN6PTON_DELIM) {
+				/* We've processed last word */
+				break;
+			}
+			/*
+			 * COLON_1 => XDIGIT
+			 * COLON_2 => XDIGIT|DELIM
+			 * COLON_1_2 => COLON_2
+			 */
+			switch (state & IN6PTON_COLON_MASK) {
+			case IN6PTON_COLON_2:
+				dc = d;
+				state = IN6PTON_XDIGIT | IN6PTON_DELIM;
+				if (dc - dbuf >= sizeof(dbuf))
+					state |= IN6PTON_NULL;
+				break;
+			case IN6PTON_COLON_1|IN6PTON_COLON_1_2:
+				state = IN6PTON_XDIGIT | IN6PTON_COLON_2;
+				break;
+			case IN6PTON_COLON_1:
+				state = IN6PTON_XDIGIT;
+				break;
+			case IN6PTON_COLON_1_2:
+				state = IN6PTON_COLON_2;
+				break;
+			default:
+				state = 0;
+			}
+			tok = s + 1;
+			goto cont;
+		}
+
+		if (c & IN6PTON_DOT) {
+			ret = in4_pton(tok ? tok : s, srclen + (int)(s - tok), d, delim, &s);
+			if (ret > 0) {
+				d += 4;
+				break;
+			}
+			goto out;
+		}
+
+		w = (w << 4) | (0xff & c);
+		state = IN6PTON_COLON_1 | IN6PTON_DELIM;
+		if (!(w & 0xf000)) {
+			state |= IN6PTON_XDIGIT;
+		}
+		if (!dc && d + 2 < dbuf + sizeof(dbuf)) {
+			state |= IN6PTON_COLON_1_2;
+			state &= ~IN6PTON_DELIM;
+		}
+		if (d + 2 >= dbuf + sizeof(dbuf)) {
+			state &= ~(IN6PTON_COLON_1|IN6PTON_COLON_1_2);
+		}
+cont:
+		if ((dc && d + 4 < dbuf + sizeof(dbuf)) ||
+		    d + 4 == dbuf + sizeof(dbuf)) {
+			state |= IN6PTON_DOT;
+		}
+		if (d >= dbuf + sizeof(dbuf)) {
+			state &= ~(IN6PTON_XDIGIT|IN6PTON_COLON_MASK);
+		}
+		s++;
+		srclen--;
+	}
+
+	i = 15; d--;
+
+	if (dc) {
+		while (d >= dc)
+			dst[i--] = *d--;
+		while (i >= dc - dbuf)
+			dst[i--] = 0;
+		while (i >= 0)
+			dst[i--] = *d--;
+	} else
+		memcpy(dst, dbuf, sizeof(dbuf));
+
+	ret = 1;
+out:
+	if (end)
+		*end = s;
+	return ret;
+}
+EXPORT_SYMBOL(in6_pton);
+
+static int inet4_pton(const char *src, u16 port_num,
+		struct sockaddr_storage *addr)
+{
+	struct sockaddr_in *addr4 = (struct sockaddr_in *)addr;
+	size_t srclen = strlen(src);
+
+	if (srclen > INET_ADDRSTRLEN)
+		return -EINVAL;
+
+	if (in4_pton(src, srclen, (u8 *)&addr4->sin_addr.s_addr,
+		     '\n', NULL) == 0)
+		return -EINVAL;
+
+	addr4->sin_family = AF_INET;
+	addr4->sin_port = htons(port_num);
+
+	return 0;
+}
+
+static int inet6_pton(struct net *net, const char *src, u16 port_num,
+		struct sockaddr_storage *addr)
+{
+	struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)addr;
+	const char *scope_delim;
+	size_t srclen = strlen(src);
+
+	if (srclen > INET6_ADDRSTRLEN)
+		return -EINVAL;
+
+	if (in6_pton(src, srclen, (u8 *)&addr6->sin6_addr.s6_addr,
+		     '%', &scope_delim) == 0)
+		return -EINVAL;
+
+	if (ipv6_addr_type(&addr6->sin6_addr) & IPV6_ADDR_LINKLOCAL &&
+	    src + srclen != scope_delim && *scope_delim == '%') {
+		struct net_device *dev;
+		char scope_id[16];
+		size_t scope_len = min_t(size_t, sizeof(scope_id) - 1,
+					 src + srclen - scope_delim - 1);
+
+		memcpy(scope_id, scope_delim + 1, scope_len);
+		scope_id[scope_len] = '\0';
+
+		dev = dev_get_by_name(net, scope_id);
+		if (dev) {
+			addr6->sin6_scope_id = dev->ifindex;
+			dev_put(dev);
+		} else if (kstrtouint(scope_id, 0, &addr6->sin6_scope_id)) {
+			return -EINVAL;
+		}
+	}
+
+	addr6->sin6_family = AF_INET6;
+	addr6->sin6_port = htons(port_num);
+
+	return 0;
+}
+
+/**
+ * inet_pton_with_scope - convert an IPv4/IPv6 and port to socket address
+ * @net: net namespace (used for scope handling)
+ * @af: address family, AF_INET, AF_INET6 or AF_UNSPEC for either
+ * @src: the start of the address string
+ * @port: the start of the port string (or NULL for none)
+ * @addr: output socket address
+ *
+ * Return zero on success, return errno when any error occurs.
+ */
+int inet_pton_with_scope(struct net *net, __kernel_sa_family_t af,
+		const char *src, const char *port, struct sockaddr_storage *addr)
+{
+	u16 port_num;
+	int ret = -EINVAL;
+
+	if (port) {
+		if (kstrtou16(port, 0, &port_num))
+			return -EINVAL;
+	} else {
+		port_num = 0;
+	}
+
+	switch (af) {
+	case AF_INET:
+		ret = inet4_pton(src, port_num, addr);
+		break;
+	case AF_INET6:
+		ret = inet6_pton(net, src, port_num, addr);
+		break;
+	case AF_UNSPEC:
+		ret = inet4_pton(src, port_num, addr);
+		if (ret)
+			ret = inet6_pton(net, src, port_num, addr);
+		break;
+	default:
+		pr_err("unexpected address family %d\n", af);
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL(inet_pton_with_scope);
+
+bool inet_addr_is_any(struct sockaddr *addr)
+{
+	if (addr->sa_family == AF_INET6) {
+		struct sockaddr_in6 *in6 = (struct sockaddr_in6 *)addr;
+		const struct sockaddr_in6 in6_any =
+			{ .sin6_addr = IN6ADDR_ANY_INIT };
+
+		if (!memcmp(in6->sin6_addr.s6_addr,
+			    in6_any.sin6_addr.s6_addr, 16))
+			return true;
+	} else if (addr->sa_family == AF_INET) {
+		struct sockaddr_in *in = (struct sockaddr_in *)addr;
+
+		if (in->sin_addr.s_addr == htonl(INADDR_ANY))
+			return true;
+	} else {
+		pr_warn("unexpected address family %u\n", addr->sa_family);
+	}
+
+	return false;
+}
+EXPORT_SYMBOL(inet_addr_is_any);
+
+void inet_proto_csum_replace4(__sum16 *sum, struct sk_buff *skb,
+			      __be32 from, __be32 to, bool pseudohdr)
+{
+	if (skb->ip_summed != CHECKSUM_PARTIAL) {
+		csum_replace4(sum, from, to);
+		if (skb->ip_summed == CHECKSUM_COMPLETE && pseudohdr)
+			skb->csum = ~csum_add(csum_sub(~(skb->csum),
+						       (__force __wsum)from),
+					      (__force __wsum)to);
+	} else if (pseudohdr)
+		*sum = ~csum_fold(csum_add(csum_sub(csum_unfold(*sum),
+						    (__force __wsum)from),
+					   (__force __wsum)to));
+}
+EXPORT_SYMBOL(inet_proto_csum_replace4);
+
+/**
+ * inet_proto_csum_replace16 - update layer 4 header checksum field
+ * @sum: Layer 4 header checksum field
+ * @skb: sk_buff for the packet
+ * @from: old IPv6 address
+ * @to: new IPv6 address
+ * @pseudohdr: True if layer 4 header checksum includes pseudoheader
+ *
+ * Update layer 4 header as per the update in IPv6 src/dst address.
+ *
+ * There is no need to update skb->csum in this function, because update in two
+ * fields a.) IPv6 src/dst address and b.) L4 header checksum cancels each other
+ * for skb->csum calculation. Whereas inet_proto_csum_replace4 function needs to
+ * update skb->csum, because update in 3 fields a.) IPv4 src/dst address,
+ * b.) IPv4 Header checksum and c.) L4 header checksum results in same diff as
+ * L4 Header checksum for skb->csum calculation.
+ */
+void inet_proto_csum_replace16(__sum16 *sum, struct sk_buff *skb,
+			       const __be32 *from, const __be32 *to,
+			       bool pseudohdr)
+{
+	__be32 diff[] = {
+		~from[0], ~from[1], ~from[2], ~from[3],
+		to[0], to[1], to[2], to[3],
+	};
+	if (skb->ip_summed != CHECKSUM_PARTIAL) {
+		*sum = csum_fold(csum_partial(diff, sizeof(diff),
+				 ~csum_unfold(*sum)));
+	} else if (pseudohdr)
+		*sum = ~csum_fold(csum_partial(diff, sizeof(diff),
+				  csum_unfold(*sum)));
+}
+EXPORT_SYMBOL(inet_proto_csum_replace16);
+
+void inet_proto_csum_replace_by_diff(__sum16 *sum, struct sk_buff *skb,
+				     __wsum diff, bool pseudohdr)
+{
+	if (skb->ip_summed != CHECKSUM_PARTIAL) {
+		csum_replace_by_diff(sum, diff);
+		if (skb->ip_summed == CHECKSUM_COMPLETE && pseudohdr)
+			skb->csum = ~csum_sub(diff, skb->csum);
+	} else if (pseudohdr) {
+		*sum = ~csum_fold(csum_add(diff, csum_unfold(*sum)));
+	}
+}
+EXPORT_SYMBOL(inet_proto_csum_replace_by_diff);