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, 757 insertions, 0 deletions

diff --git a/net/rds/tcp.c b/net/rds/tcp.c
new file mode 100644
index 000000000..c5b86066f
--- /dev/null
+++ b/net/rds/tcp.c
@@ -0,0 +1,757 @@
+/*
+ * Copyright (c) 2006, 2018 Oracle and/or its affiliates. All rights reserved.
+ *
+ * This software is available to you under a choice of one of two
+ * licenses.  You may choose to be licensed under the terms of the GNU
+ * General Public License (GPL) Version 2, available from the file
+ * COPYING in the main directory of this source tree, or the
+ * OpenIB.org BSD license below:
+ *
+ *     Redistribution and use in source and binary forms, with or
+ *     without modification, are permitted provided that the following
+ *     conditions are met:
+ *
+ *      - Redistributions of source code must retain the above
+ *        copyright notice, this list of conditions and the following
+ *        disclaimer.
+ *
+ *      - Redistributions in binary form must reproduce the above
+ *        copyright notice, this list of conditions and the following
+ *        disclaimer in the documentation and/or other materials
+ *        provided with the distribution.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ */
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/in.h>
+#include <linux/module.h>
+#include <net/tcp.h>
+#include <net/net_namespace.h>
+#include <net/netns/generic.h>
+#include <net/addrconf.h>
+
+#include "rds.h"
+#include "tcp.h"
+
+/* only for info exporting */
+static DEFINE_SPINLOCK(rds_tcp_tc_list_lock);
+static LIST_HEAD(rds_tcp_tc_list);
+
+/* rds_tcp_tc_count counts only IPv4 connections.
+ * rds6_tcp_tc_count counts both IPv4 and IPv6 connections.
+ */
+static unsigned int rds_tcp_tc_count;
+#if IS_ENABLED(CONFIG_IPV6)
+static unsigned int rds6_tcp_tc_count;
+#endif
+
+/* Track rds_tcp_connection structs so they can be cleaned up */
+static DEFINE_SPINLOCK(rds_tcp_conn_lock);
+static LIST_HEAD(rds_tcp_conn_list);
+static atomic_t rds_tcp_unloading = ATOMIC_INIT(0);
+
+static struct kmem_cache *rds_tcp_conn_slab;
+
+static int rds_tcp_skbuf_handler(struct ctl_table *ctl, int write,
+				 void *buffer, size_t *lenp, loff_t *fpos);
+
+static int rds_tcp_min_sndbuf = SOCK_MIN_SNDBUF;
+static int rds_tcp_min_rcvbuf = SOCK_MIN_RCVBUF;
+
+static struct ctl_table rds_tcp_sysctl_table[] = {
+#define	RDS_TCP_SNDBUF	0
+	{
+		.procname       = "rds_tcp_sndbuf",
+		/* data is per-net pointer */
+		.maxlen         = sizeof(int),
+		.mode           = 0644,
+		.proc_handler   = rds_tcp_skbuf_handler,
+		.extra1		= &rds_tcp_min_sndbuf,
+	},
+#define	RDS_TCP_RCVBUF	1
+	{
+		.procname       = "rds_tcp_rcvbuf",
+		/* data is per-net pointer */
+		.maxlen         = sizeof(int),
+		.mode           = 0644,
+		.proc_handler   = rds_tcp_skbuf_handler,
+		.extra1		= &rds_tcp_min_rcvbuf,
+	},
+	{ }
+};
+
+u32 rds_tcp_write_seq(struct rds_tcp_connection *tc)
+{
+	/* seq# of the last byte of data in tcp send buffer */
+	return tcp_sk(tc->t_sock->sk)->write_seq;
+}
+
+u32 rds_tcp_snd_una(struct rds_tcp_connection *tc)
+{
+	return tcp_sk(tc->t_sock->sk)->snd_una;
+}
+
+void rds_tcp_restore_callbacks(struct socket *sock,
+			       struct rds_tcp_connection *tc)
+{
+	rdsdebug("restoring sock %p callbacks from tc %p\n", sock, tc);
+	write_lock_bh(&sock->sk->sk_callback_lock);
+
+	/* done under the callback_lock to serialize with write_space */
+	spin_lock(&rds_tcp_tc_list_lock);
+	list_del_init(&tc->t_list_item);
+#if IS_ENABLED(CONFIG_IPV6)
+	rds6_tcp_tc_count--;
+#endif
+	if (!tc->t_cpath->cp_conn->c_isv6)
+		rds_tcp_tc_count--;
+	spin_unlock(&rds_tcp_tc_list_lock);
+
+	tc->t_sock = NULL;
+
+	sock->sk->sk_write_space = tc->t_orig_write_space;
+	sock->sk->sk_data_ready = tc->t_orig_data_ready;
+	sock->sk->sk_state_change = tc->t_orig_state_change;
+	sock->sk->sk_user_data = NULL;
+
+	write_unlock_bh(&sock->sk->sk_callback_lock);
+}
+
+/*
+ * rds_tcp_reset_callbacks() switches the to the new sock and
+ * returns the existing tc->t_sock.
+ *
+ * The only functions that set tc->t_sock are rds_tcp_set_callbacks
+ * and rds_tcp_reset_callbacks.  Send and receive trust that
+ * it is set.  The absence of RDS_CONN_UP bit protects those paths
+ * from being called while it isn't set.
+ */
+void rds_tcp_reset_callbacks(struct socket *sock,
+			     struct rds_conn_path *cp)
+{
+	struct rds_tcp_connection *tc = cp->cp_transport_data;
+	struct socket *osock = tc->t_sock;
+
+	if (!osock)
+		goto newsock;
+
+	/* Need to resolve a duelling SYN between peers.
+	 * We have an outstanding SYN to this peer, which may
+	 * potentially have transitioned to the RDS_CONN_UP state,
+	 * so we must quiesce any send threads before resetting
+	 * cp_transport_data. We quiesce these threads by setting
+	 * cp_state to something other than RDS_CONN_UP, and then
+	 * waiting for any existing threads in rds_send_xmit to
+	 * complete release_in_xmit(). (Subsequent threads entering
+	 * rds_send_xmit() will bail on !rds_conn_up().
+	 *
+	 * However an incoming syn-ack at this point would end up
+	 * marking the conn as RDS_CONN_UP, and would again permit
+	 * rds_send_xmi() threads through, so ideally we would
+	 * synchronize on RDS_CONN_UP after lock_sock(), but cannot
+	 * do that: waiting on !RDS_IN_XMIT after lock_sock() may
+	 * end up deadlocking with tcp_sendmsg(), and the RDS_IN_XMIT
+	 * would not get set. As a result, we set c_state to
+	 * RDS_CONN_RESETTTING, to ensure that rds_tcp_state_change
+	 * cannot mark rds_conn_path_up() in the window before lock_sock()
+	 */
+	atomic_set(&cp->cp_state, RDS_CONN_RESETTING);
+	wait_event(cp->cp_waitq, !test_bit(RDS_IN_XMIT, &cp->cp_flags));
+	/* reset receive side state for rds_tcp_data_recv() for osock  */
+	cancel_delayed_work_sync(&cp->cp_send_w);
+	cancel_delayed_work_sync(&cp->cp_recv_w);
+	lock_sock(osock->sk);
+	if (tc->t_tinc) {
+		rds_inc_put(&tc->t_tinc->ti_inc);
+		tc->t_tinc = NULL;
+	}
+	tc->t_tinc_hdr_rem = sizeof(struct rds_header);
+	tc->t_tinc_data_rem = 0;
+	rds_tcp_restore_callbacks(osock, tc);
+	release_sock(osock->sk);
+	sock_release(osock);
+newsock:
+	rds_send_path_reset(cp);
+	lock_sock(sock->sk);
+	rds_tcp_set_callbacks(sock, cp);
+	release_sock(sock->sk);
+}
+
+/* Add tc to rds_tcp_tc_list and set tc->t_sock. See comments
+ * above rds_tcp_reset_callbacks for notes about synchronization
+ * with data path
+ */
+void rds_tcp_set_callbacks(struct socket *sock, struct rds_conn_path *cp)
+{
+	struct rds_tcp_connection *tc = cp->cp_transport_data;
+
+	rdsdebug("setting sock %p callbacks to tc %p\n", sock, tc);
+	write_lock_bh(&sock->sk->sk_callback_lock);
+
+	/* done under the callback_lock to serialize with write_space */
+	spin_lock(&rds_tcp_tc_list_lock);
+	list_add_tail(&tc->t_list_item, &rds_tcp_tc_list);
+#if IS_ENABLED(CONFIG_IPV6)
+	rds6_tcp_tc_count++;
+#endif
+	if (!tc->t_cpath->cp_conn->c_isv6)
+		rds_tcp_tc_count++;
+	spin_unlock(&rds_tcp_tc_list_lock);
+
+	/* accepted sockets need our listen data ready undone */
+	if (sock->sk->sk_data_ready == rds_tcp_listen_data_ready)
+		sock->sk->sk_data_ready = sock->sk->sk_user_data;
+
+	tc->t_sock = sock;
+	tc->t_cpath = cp;
+	tc->t_orig_data_ready = sock->sk->sk_data_ready;
+	tc->t_orig_write_space = sock->sk->sk_write_space;
+	tc->t_orig_state_change = sock->sk->sk_state_change;
+
+	sock->sk->sk_user_data = cp;
+	sock->sk->sk_data_ready = rds_tcp_data_ready;
+	sock->sk->sk_write_space = rds_tcp_write_space;
+	sock->sk->sk_state_change = rds_tcp_state_change;
+
+	write_unlock_bh(&sock->sk->sk_callback_lock);
+}
+
+/* Handle RDS_INFO_TCP_SOCKETS socket option.  It only returns IPv4
+ * connections for backward compatibility.
+ */
+static void rds_tcp_tc_info(struct socket *rds_sock, unsigned int len,
+			    struct rds_info_iterator *iter,
+			    struct rds_info_lengths *lens)
+{
+	struct rds_info_tcp_socket tsinfo;
+	struct rds_tcp_connection *tc;
+	unsigned long flags;
+
+	spin_lock_irqsave(&rds_tcp_tc_list_lock, flags);
+
+	if (len / sizeof(tsinfo) < rds_tcp_tc_count)
+		goto out;
+
+	list_for_each_entry(tc, &rds_tcp_tc_list, t_list_item) {
+		struct inet_sock *inet = inet_sk(tc->t_sock->sk);
+
+		if (tc->t_cpath->cp_conn->c_isv6)
+			continue;
+
+		tsinfo.local_addr = inet->inet_saddr;
+		tsinfo.local_port = inet->inet_sport;
+		tsinfo.peer_addr = inet->inet_daddr;
+		tsinfo.peer_port = inet->inet_dport;
+
+		tsinfo.hdr_rem = tc->t_tinc_hdr_rem;
+		tsinfo.data_rem = tc->t_tinc_data_rem;
+		tsinfo.last_sent_nxt = tc->t_last_sent_nxt;
+		tsinfo.last_expected_una = tc->t_last_expected_una;
+		tsinfo.last_seen_una = tc->t_last_seen_una;
+		tsinfo.tos = tc->t_cpath->cp_conn->c_tos;
+
+		rds_info_copy(iter, &tsinfo, sizeof(tsinfo));
+	}
+
+out:
+	lens->nr = rds_tcp_tc_count;
+	lens->each = sizeof(tsinfo);
+
+	spin_unlock_irqrestore(&rds_tcp_tc_list_lock, flags);
+}
+
+#if IS_ENABLED(CONFIG_IPV6)
+/* Handle RDS6_INFO_TCP_SOCKETS socket option. It returns both IPv4 and
+ * IPv6 connections. IPv4 connection address is returned in an IPv4 mapped
+ * address.
+ */
+static void rds6_tcp_tc_info(struct socket *sock, unsigned int len,
+			     struct rds_info_iterator *iter,
+			     struct rds_info_lengths *lens)
+{
+	struct rds6_info_tcp_socket tsinfo6;
+	struct rds_tcp_connection *tc;
+	unsigned long flags;
+
+	spin_lock_irqsave(&rds_tcp_tc_list_lock, flags);
+
+	if (len / sizeof(tsinfo6) < rds6_tcp_tc_count)
+		goto out;
+
+	list_for_each_entry(tc, &rds_tcp_tc_list, t_list_item) {
+		struct sock *sk = tc->t_sock->sk;
+		struct inet_sock *inet = inet_sk(sk);
+
+		tsinfo6.local_addr = sk->sk_v6_rcv_saddr;
+		tsinfo6.local_port = inet->inet_sport;
+		tsinfo6.peer_addr = sk->sk_v6_daddr;
+		tsinfo6.peer_port = inet->inet_dport;
+
+		tsinfo6.hdr_rem = tc->t_tinc_hdr_rem;
+		tsinfo6.data_rem = tc->t_tinc_data_rem;
+		tsinfo6.last_sent_nxt = tc->t_last_sent_nxt;
+		tsinfo6.last_expected_una = tc->t_last_expected_una;
+		tsinfo6.last_seen_una = tc->t_last_seen_una;
+
+		rds_info_copy(iter, &tsinfo6, sizeof(tsinfo6));
+	}
+
+out:
+	lens->nr = rds6_tcp_tc_count;
+	lens->each = sizeof(tsinfo6);
+
+	spin_unlock_irqrestore(&rds_tcp_tc_list_lock, flags);
+}
+#endif
+
+int rds_tcp_laddr_check(struct net *net, const struct in6_addr *addr,
+			__u32 scope_id)
+{
+	struct net_device *dev = NULL;
+#if IS_ENABLED(CONFIG_IPV6)
+	int ret;
+#endif
+
+	if (ipv6_addr_v4mapped(addr)) {
+		if (inet_addr_type(net, addr->s6_addr32[3]) == RTN_LOCAL)
+			return 0;
+		return -EADDRNOTAVAIL;
+	}
+
+	/* If the scope_id is specified, check only those addresses
+	 * hosted on the specified interface.
+	 */
+	if (scope_id != 0) {
+		rcu_read_lock();
+		dev = dev_get_by_index_rcu(net, scope_id);
+		/* scope_id is not valid... */
+		if (!dev) {
+			rcu_read_unlock();
+			return -EADDRNOTAVAIL;
+		}
+		rcu_read_unlock();
+	}
+#if IS_ENABLED(CONFIG_IPV6)
+	ret = ipv6_chk_addr(net, addr, dev, 0);
+	if (ret)
+		return 0;
+#endif
+	return -EADDRNOTAVAIL;
+}
+
+static void rds_tcp_conn_free(void *arg)
+{
+	struct rds_tcp_connection *tc = arg;
+	unsigned long flags;
+
+	rdsdebug("freeing tc %p\n", tc);
+
+	spin_lock_irqsave(&rds_tcp_conn_lock, flags);
+	if (!tc->t_tcp_node_detached)
+		list_del(&tc->t_tcp_node);
+	spin_unlock_irqrestore(&rds_tcp_conn_lock, flags);
+
+	kmem_cache_free(rds_tcp_conn_slab, tc);
+}
+
+static int rds_tcp_conn_alloc(struct rds_connection *conn, gfp_t gfp)
+{
+	struct rds_tcp_connection *tc;
+	int i, j;
+	int ret = 0;
+
+	for (i = 0; i < RDS_MPATH_WORKERS; i++) {
+		tc = kmem_cache_alloc(rds_tcp_conn_slab, gfp);
+		if (!tc) {
+			ret = -ENOMEM;
+			goto fail;
+		}
+		mutex_init(&tc->t_conn_path_lock);
+		tc->t_sock = NULL;
+		tc->t_tinc = NULL;
+		tc->t_tinc_hdr_rem = sizeof(struct rds_header);
+		tc->t_tinc_data_rem = 0;
+
+		conn->c_path[i].cp_transport_data = tc;
+		tc->t_cpath = &conn->c_path[i];
+		tc->t_tcp_node_detached = true;
+
+		rdsdebug("rds_conn_path [%d] tc %p\n", i,
+			 conn->c_path[i].cp_transport_data);
+	}
+	spin_lock_irq(&rds_tcp_conn_lock);
+	for (i = 0; i < RDS_MPATH_WORKERS; i++) {
+		tc = conn->c_path[i].cp_transport_data;
+		tc->t_tcp_node_detached = false;
+		list_add_tail(&tc->t_tcp_node, &rds_tcp_conn_list);
+	}
+	spin_unlock_irq(&rds_tcp_conn_lock);
+fail:
+	if (ret) {
+		for (j = 0; j < i; j++)
+			rds_tcp_conn_free(conn->c_path[j].cp_transport_data);
+	}
+	return ret;
+}
+
+static bool list_has_conn(struct list_head *list, struct rds_connection *conn)
+{
+	struct rds_tcp_connection *tc, *_tc;
+
+	list_for_each_entry_safe(tc, _tc, list, t_tcp_node) {
+		if (tc->t_cpath->cp_conn == conn)
+			return true;
+	}
+	return false;
+}
+
+static void rds_tcp_set_unloading(void)
+{
+	atomic_set(&rds_tcp_unloading, 1);
+}
+
+static bool rds_tcp_is_unloading(struct rds_connection *conn)
+{
+	return atomic_read(&rds_tcp_unloading) != 0;
+}
+
+static void rds_tcp_destroy_conns(void)
+{
+	struct rds_tcp_connection *tc, *_tc;
+	LIST_HEAD(tmp_list);
+
+	/* avoid calling conn_destroy with irqs off */
+	spin_lock_irq(&rds_tcp_conn_lock);
+	list_for_each_entry_safe(tc, _tc, &rds_tcp_conn_list, t_tcp_node) {
+		if (!list_has_conn(&tmp_list, tc->t_cpath->cp_conn))
+			list_move_tail(&tc->t_tcp_node, &tmp_list);
+	}
+	spin_unlock_irq(&rds_tcp_conn_lock);
+
+	list_for_each_entry_safe(tc, _tc, &tmp_list, t_tcp_node)
+		rds_conn_destroy(tc->t_cpath->cp_conn);
+}
+
+static void rds_tcp_exit(void);
+
+static u8 rds_tcp_get_tos_map(u8 tos)
+{
+	/* all user tos mapped to default 0 for TCP transport */
+	return 0;
+}
+
+struct rds_transport rds_tcp_transport = {
+	.laddr_check		= rds_tcp_laddr_check,
+	.xmit_path_prepare	= rds_tcp_xmit_path_prepare,
+	.xmit_path_complete	= rds_tcp_xmit_path_complete,
+	.xmit			= rds_tcp_xmit,
+	.recv_path		= rds_tcp_recv_path,
+	.conn_alloc		= rds_tcp_conn_alloc,
+	.conn_free		= rds_tcp_conn_free,
+	.conn_path_connect	= rds_tcp_conn_path_connect,
+	.conn_path_shutdown	= rds_tcp_conn_path_shutdown,
+	.inc_copy_to_user	= rds_tcp_inc_copy_to_user,
+	.inc_free		= rds_tcp_inc_free,
+	.stats_info_copy	= rds_tcp_stats_info_copy,
+	.exit			= rds_tcp_exit,
+	.get_tos_map		= rds_tcp_get_tos_map,
+	.t_owner		= THIS_MODULE,
+	.t_name			= "tcp",
+	.t_type			= RDS_TRANS_TCP,
+	.t_prefer_loopback	= 1,
+	.t_mp_capable		= 1,
+	.t_unloading		= rds_tcp_is_unloading,
+};
+
+static unsigned int rds_tcp_netid;
+
+/* per-network namespace private data for this module */
+struct rds_tcp_net {
+	struct socket *rds_tcp_listen_sock;
+	struct work_struct rds_tcp_accept_w;
+	struct ctl_table_header *rds_tcp_sysctl;
+	struct ctl_table *ctl_table;
+	int sndbuf_size;
+	int rcvbuf_size;
+};
+
+/* All module specific customizations to the RDS-TCP socket should be done in
+ * rds_tcp_tune() and applied after socket creation.
+ */
+bool rds_tcp_tune(struct socket *sock)
+{
+	struct sock *sk = sock->sk;
+	struct net *net = sock_net(sk);
+	struct rds_tcp_net *rtn;
+
+	tcp_sock_set_nodelay(sock->sk);
+	lock_sock(sk);
+	/* TCP timer functions might access net namespace even after
+	 * a process which created this net namespace terminated.
+	 */
+	if (!sk->sk_net_refcnt) {
+		if (!maybe_get_net(net)) {
+			release_sock(sk);
+			return false;
+		}
+		/* Update ns_tracker to current stack trace and refcounted tracker */
+		__netns_tracker_free(net, &sk->ns_tracker, false);
+
+		sk->sk_net_refcnt = 1;
+		netns_tracker_alloc(net, &sk->ns_tracker, GFP_KERNEL);
+		sock_inuse_add(net, 1);
+	}
+	rtn = net_generic(net, rds_tcp_netid);
+	if (rtn->sndbuf_size > 0) {
+		sk->sk_sndbuf = rtn->sndbuf_size;
+		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
+	}
+	if (rtn->rcvbuf_size > 0) {
+		sk->sk_rcvbuf = rtn->rcvbuf_size;
+		sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
+	}
+	release_sock(sk);
+	return true;
+}
+
+static void rds_tcp_accept_worker(struct work_struct *work)
+{
+	struct rds_tcp_net *rtn = container_of(work,
+					       struct rds_tcp_net,
+					       rds_tcp_accept_w);
+
+	while (rds_tcp_accept_one(rtn->rds_tcp_listen_sock) == 0)
+		cond_resched();
+}
+
+void rds_tcp_accept_work(struct sock *sk)
+{
+	struct net *net = sock_net(sk);
+	struct rds_tcp_net *rtn = net_generic(net, rds_tcp_netid);
+
+	queue_work(rds_wq, &rtn->rds_tcp_accept_w);
+}
+
+static __net_init int rds_tcp_init_net(struct net *net)
+{
+	struct rds_tcp_net *rtn = net_generic(net, rds_tcp_netid);
+	struct ctl_table *tbl;
+	int err = 0;
+
+	memset(rtn, 0, sizeof(*rtn));
+
+	/* {snd, rcv}buf_size default to 0, which implies we let the
+	 * stack pick the value, and permit auto-tuning of buffer size.
+	 */
+	if (net == &init_net) {
+		tbl = rds_tcp_sysctl_table;
+	} else {
+		tbl = kmemdup(rds_tcp_sysctl_table,
+			      sizeof(rds_tcp_sysctl_table), GFP_KERNEL);
+		if (!tbl) {
+			pr_warn("could not set allocate sysctl table\n");
+			return -ENOMEM;
+		}
+		rtn->ctl_table = tbl;
+	}
+	tbl[RDS_TCP_SNDBUF].data = &rtn->sndbuf_size;
+	tbl[RDS_TCP_RCVBUF].data = &rtn->rcvbuf_size;
+	rtn->rds_tcp_sysctl = register_net_sysctl(net, "net/rds/tcp", tbl);
+	if (!rtn->rds_tcp_sysctl) {
+		pr_warn("could not register sysctl\n");
+		err = -ENOMEM;
+		goto fail;
+	}
+
+#if IS_ENABLED(CONFIG_IPV6)
+	rtn->rds_tcp_listen_sock = rds_tcp_listen_init(net, true);
+#else
+	rtn->rds_tcp_listen_sock = rds_tcp_listen_init(net, false);
+#endif
+	if (!rtn->rds_tcp_listen_sock) {
+		pr_warn("could not set up IPv6 listen sock\n");
+
+#if IS_ENABLED(CONFIG_IPV6)
+		/* Try IPv4 as some systems disable IPv6 */
+		rtn->rds_tcp_listen_sock = rds_tcp_listen_init(net, false);
+		if (!rtn->rds_tcp_listen_sock) {
+#endif
+			unregister_net_sysctl_table(rtn->rds_tcp_sysctl);
+			rtn->rds_tcp_sysctl = NULL;
+			err = -EAFNOSUPPORT;
+			goto fail;
+#if IS_ENABLED(CONFIG_IPV6)
+		}
+#endif
+	}
+	INIT_WORK(&rtn->rds_tcp_accept_w, rds_tcp_accept_worker);
+	return 0;
+
+fail:
+	if (net != &init_net)
+		kfree(tbl);
+	return err;
+}
+
+static void rds_tcp_kill_sock(struct net *net)
+{
+	struct rds_tcp_connection *tc, *_tc;
+	LIST_HEAD(tmp_list);
+	struct rds_tcp_net *rtn = net_generic(net, rds_tcp_netid);
+	struct socket *lsock = rtn->rds_tcp_listen_sock;
+
+	rtn->rds_tcp_listen_sock = NULL;
+	rds_tcp_listen_stop(lsock, &rtn->rds_tcp_accept_w);
+	spin_lock_irq(&rds_tcp_conn_lock);
+	list_for_each_entry_safe(tc, _tc, &rds_tcp_conn_list, t_tcp_node) {
+		struct net *c_net = read_pnet(&tc->t_cpath->cp_conn->c_net);
+
+		if (net != c_net)
+			continue;
+		if (!list_has_conn(&tmp_list, tc->t_cpath->cp_conn)) {
+			list_move_tail(&tc->t_tcp_node, &tmp_list);
+		} else {
+			list_del(&tc->t_tcp_node);
+			tc->t_tcp_node_detached = true;
+		}
+	}
+	spin_unlock_irq(&rds_tcp_conn_lock);
+	list_for_each_entry_safe(tc, _tc, &tmp_list, t_tcp_node)
+		rds_conn_destroy(tc->t_cpath->cp_conn);
+}
+
+static void __net_exit rds_tcp_exit_net(struct net *net)
+{
+	struct rds_tcp_net *rtn = net_generic(net, rds_tcp_netid);
+
+	rds_tcp_kill_sock(net);
+
+	if (rtn->rds_tcp_sysctl)
+		unregister_net_sysctl_table(rtn->rds_tcp_sysctl);
+
+	if (net != &init_net)
+		kfree(rtn->ctl_table);
+}
+
+static struct pernet_operations rds_tcp_net_ops = {
+	.init = rds_tcp_init_net,
+	.exit = rds_tcp_exit_net,
+	.id = &rds_tcp_netid,
+	.size = sizeof(struct rds_tcp_net),
+};
+
+void *rds_tcp_listen_sock_def_readable(struct net *net)
+{
+	struct rds_tcp_net *rtn = net_generic(net, rds_tcp_netid);
+	struct socket *lsock = rtn->rds_tcp_listen_sock;
+
+	if (!lsock)
+		return NULL;
+
+	return lsock->sk->sk_user_data;
+}
+
+/* when sysctl is used to modify some kernel socket parameters,this
+ * function  resets the RDS connections in that netns  so that we can
+ * restart with new parameters.  The assumption is that such reset
+ * events are few and far-between.
+ */
+static void rds_tcp_sysctl_reset(struct net *net)
+{
+	struct rds_tcp_connection *tc, *_tc;
+
+	spin_lock_irq(&rds_tcp_conn_lock);
+	list_for_each_entry_safe(tc, _tc, &rds_tcp_conn_list, t_tcp_node) {
+		struct net *c_net = read_pnet(&tc->t_cpath->cp_conn->c_net);
+
+		if (net != c_net || !tc->t_sock)
+			continue;
+
+		/* reconnect with new parameters */
+		rds_conn_path_drop(tc->t_cpath, false);
+	}
+	spin_unlock_irq(&rds_tcp_conn_lock);
+}
+
+static int rds_tcp_skbuf_handler(struct ctl_table *ctl, int write,
+				 void *buffer, size_t *lenp, loff_t *fpos)
+{
+	struct net *net = current->nsproxy->net_ns;
+	int err;
+
+	err = proc_dointvec_minmax(ctl, write, buffer, lenp, fpos);
+	if (err < 0) {
+		pr_warn("Invalid input. Must be >= %d\n",
+			*(int *)(ctl->extra1));
+		return err;
+	}
+	if (write)
+		rds_tcp_sysctl_reset(net);
+	return 0;
+}
+
+static void rds_tcp_exit(void)
+{
+	rds_tcp_set_unloading();
+	synchronize_rcu();
+	rds_info_deregister_func(RDS_INFO_TCP_SOCKETS, rds_tcp_tc_info);
+#if IS_ENABLED(CONFIG_IPV6)
+	rds_info_deregister_func(RDS6_INFO_TCP_SOCKETS, rds6_tcp_tc_info);
+#endif
+	unregister_pernet_device(&rds_tcp_net_ops);
+	rds_tcp_destroy_conns();
+	rds_trans_unregister(&rds_tcp_transport);
+	rds_tcp_recv_exit();
+	kmem_cache_destroy(rds_tcp_conn_slab);
+}
+module_exit(rds_tcp_exit);
+
+static int __init rds_tcp_init(void)
+{
+	int ret;
+
+	rds_tcp_conn_slab = kmem_cache_create("rds_tcp_connection",
+					      sizeof(struct rds_tcp_connection),
+					      0, 0, NULL);
+	if (!rds_tcp_conn_slab) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	ret = rds_tcp_recv_init();
+	if (ret)
+		goto out_slab;
+
+	ret = register_pernet_device(&rds_tcp_net_ops);
+	if (ret)
+		goto out_recv;
+
+	rds_trans_register(&rds_tcp_transport);
+
+	rds_info_register_func(RDS_INFO_TCP_SOCKETS, rds_tcp_tc_info);
+#if IS_ENABLED(CONFIG_IPV6)
+	rds_info_register_func(RDS6_INFO_TCP_SOCKETS, rds6_tcp_tc_info);
+#endif
+
+	goto out;
+out_recv:
+	rds_tcp_recv_exit();
+out_slab:
+	kmem_cache_destroy(rds_tcp_conn_slab);
+out:
+	return ret;
+}
+module_init(rds_tcp_init);
+
+MODULE_AUTHOR("Oracle Corporation <rds-devel@oss.oracle.com>");
+MODULE_DESCRIPTION("RDS: TCP transport");
+MODULE_LICENSE("Dual BSD/GPL");