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authorLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
committerLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
commit5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 (patch)
treecc5c2d0a898769fd59549594fedb3ee6f84e59a0 /net/mac80211/mesh_pathtbl.c
downloadlinux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.tar.gz
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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(). ...
Diffstat (limited to 'net/mac80211/mesh_pathtbl.c')
-rw-r--r--net/mac80211/mesh_pathtbl.c790
1 files changed, 790 insertions, 0 deletions
diff --git a/net/mac80211/mesh_pathtbl.c b/net/mac80211/mesh_pathtbl.c
new file mode 100644
index 000000000..3b81e6df3
--- /dev/null
+++ b/net/mac80211/mesh_pathtbl.c
@@ -0,0 +1,790 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2008, 2009 open80211s Ltd.
+ * Author: Luis Carlos Cobo <luisca@cozybit.com>
+ */
+
+#include <linux/etherdevice.h>
+#include <linux/list.h>
+#include <linux/random.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/string.h>
+#include <net/mac80211.h>
+#include "wme.h"
+#include "ieee80211_i.h"
+#include "mesh.h"
+
+static void mesh_path_free_rcu(struct mesh_table *tbl, struct mesh_path *mpath);
+
+static u32 mesh_table_hash(const void *addr, u32 len, u32 seed)
+{
+ /* Use last four bytes of hw addr as hash index */
+ return jhash_1word(__get_unaligned_cpu32((u8 *)addr + 2), seed);
+}
+
+static const struct rhashtable_params mesh_rht_params = {
+ .nelem_hint = 2,
+ .automatic_shrinking = true,
+ .key_len = ETH_ALEN,
+ .key_offset = offsetof(struct mesh_path, dst),
+ .head_offset = offsetof(struct mesh_path, rhash),
+ .hashfn = mesh_table_hash,
+};
+
+static inline bool mpath_expired(struct mesh_path *mpath)
+{
+ return (mpath->flags & MESH_PATH_ACTIVE) &&
+ time_after(jiffies, mpath->exp_time) &&
+ !(mpath->flags & MESH_PATH_FIXED);
+}
+
+static void mesh_path_rht_free(void *ptr, void *tblptr)
+{
+ struct mesh_path *mpath = ptr;
+ struct mesh_table *tbl = tblptr;
+
+ mesh_path_free_rcu(tbl, mpath);
+}
+
+static void mesh_table_init(struct mesh_table *tbl)
+{
+ INIT_HLIST_HEAD(&tbl->known_gates);
+ INIT_HLIST_HEAD(&tbl->walk_head);
+ atomic_set(&tbl->entries, 0);
+ spin_lock_init(&tbl->gates_lock);
+ spin_lock_init(&tbl->walk_lock);
+
+ /* rhashtable_init() may fail only in case of wrong
+ * mesh_rht_params
+ */
+ WARN_ON(rhashtable_init(&tbl->rhead, &mesh_rht_params));
+}
+
+static void mesh_table_free(struct mesh_table *tbl)
+{
+ rhashtable_free_and_destroy(&tbl->rhead,
+ mesh_path_rht_free, tbl);
+}
+
+/**
+ * mesh_path_assign_nexthop - update mesh path next hop
+ *
+ * @mpath: mesh path to update
+ * @sta: next hop to assign
+ *
+ * Locking: mpath->state_lock must be held when calling this function
+ */
+void mesh_path_assign_nexthop(struct mesh_path *mpath, struct sta_info *sta)
+{
+ struct sk_buff *skb;
+ struct ieee80211_hdr *hdr;
+ unsigned long flags;
+
+ rcu_assign_pointer(mpath->next_hop, sta);
+
+ spin_lock_irqsave(&mpath->frame_queue.lock, flags);
+ skb_queue_walk(&mpath->frame_queue, skb) {
+ hdr = (struct ieee80211_hdr *) skb->data;
+ memcpy(hdr->addr1, sta->sta.addr, ETH_ALEN);
+ memcpy(hdr->addr2, mpath->sdata->vif.addr, ETH_ALEN);
+ ieee80211_mps_set_frame_flags(sta->sdata, sta, hdr);
+ }
+
+ spin_unlock_irqrestore(&mpath->frame_queue.lock, flags);
+}
+
+static void prepare_for_gate(struct sk_buff *skb, char *dst_addr,
+ struct mesh_path *gate_mpath)
+{
+ struct ieee80211_hdr *hdr;
+ struct ieee80211s_hdr *mshdr;
+ int mesh_hdrlen, hdrlen;
+ char *next_hop;
+
+ hdr = (struct ieee80211_hdr *) skb->data;
+ hdrlen = ieee80211_hdrlen(hdr->frame_control);
+ mshdr = (struct ieee80211s_hdr *) (skb->data + hdrlen);
+
+ if (!(mshdr->flags & MESH_FLAGS_AE)) {
+ /* size of the fixed part of the mesh header */
+ mesh_hdrlen = 6;
+
+ /* make room for the two extended addresses */
+ skb_push(skb, 2 * ETH_ALEN);
+ memmove(skb->data, hdr, hdrlen + mesh_hdrlen);
+
+ hdr = (struct ieee80211_hdr *) skb->data;
+
+ /* we preserve the previous mesh header and only add
+ * the new addresses */
+ mshdr = (struct ieee80211s_hdr *) (skb->data + hdrlen);
+ mshdr->flags = MESH_FLAGS_AE_A5_A6;
+ memcpy(mshdr->eaddr1, hdr->addr3, ETH_ALEN);
+ memcpy(mshdr->eaddr2, hdr->addr4, ETH_ALEN);
+ }
+
+ /* update next hop */
+ hdr = (struct ieee80211_hdr *) skb->data;
+ rcu_read_lock();
+ next_hop = rcu_dereference(gate_mpath->next_hop)->sta.addr;
+ memcpy(hdr->addr1, next_hop, ETH_ALEN);
+ rcu_read_unlock();
+ memcpy(hdr->addr2, gate_mpath->sdata->vif.addr, ETH_ALEN);
+ memcpy(hdr->addr3, dst_addr, ETH_ALEN);
+}
+
+/**
+ * mesh_path_move_to_queue - Move or copy frames from one mpath queue to another
+ *
+ * This function is used to transfer or copy frames from an unresolved mpath to
+ * a gate mpath. The function also adds the Address Extension field and
+ * updates the next hop.
+ *
+ * If a frame already has an Address Extension field, only the next hop and
+ * destination addresses are updated.
+ *
+ * The gate mpath must be an active mpath with a valid mpath->next_hop.
+ *
+ * @gate_mpath: An active mpath the frames will be sent to (i.e. the gate)
+ * @from_mpath: The failed mpath
+ * @copy: When true, copy all the frames to the new mpath queue. When false,
+ * move them.
+ */
+static void mesh_path_move_to_queue(struct mesh_path *gate_mpath,
+ struct mesh_path *from_mpath,
+ bool copy)
+{
+ struct sk_buff *skb, *fskb, *tmp;
+ struct sk_buff_head failq;
+ unsigned long flags;
+
+ if (WARN_ON(gate_mpath == from_mpath))
+ return;
+ if (WARN_ON(!gate_mpath->next_hop))
+ return;
+
+ __skb_queue_head_init(&failq);
+
+ spin_lock_irqsave(&from_mpath->frame_queue.lock, flags);
+ skb_queue_splice_init(&from_mpath->frame_queue, &failq);
+ spin_unlock_irqrestore(&from_mpath->frame_queue.lock, flags);
+
+ skb_queue_walk_safe(&failq, fskb, tmp) {
+ if (skb_queue_len(&gate_mpath->frame_queue) >=
+ MESH_FRAME_QUEUE_LEN) {
+ mpath_dbg(gate_mpath->sdata, "mpath queue full!\n");
+ break;
+ }
+
+ skb = skb_copy(fskb, GFP_ATOMIC);
+ if (WARN_ON(!skb))
+ break;
+
+ prepare_for_gate(skb, gate_mpath->dst, gate_mpath);
+ skb_queue_tail(&gate_mpath->frame_queue, skb);
+
+ if (copy)
+ continue;
+
+ __skb_unlink(fskb, &failq);
+ kfree_skb(fskb);
+ }
+
+ mpath_dbg(gate_mpath->sdata, "Mpath queue for gate %pM has %d frames\n",
+ gate_mpath->dst, skb_queue_len(&gate_mpath->frame_queue));
+
+ if (!copy)
+ return;
+
+ spin_lock_irqsave(&from_mpath->frame_queue.lock, flags);
+ skb_queue_splice(&failq, &from_mpath->frame_queue);
+ spin_unlock_irqrestore(&from_mpath->frame_queue.lock, flags);
+}
+
+
+static struct mesh_path *mpath_lookup(struct mesh_table *tbl, const u8 *dst,
+ struct ieee80211_sub_if_data *sdata)
+{
+ struct mesh_path *mpath;
+
+ mpath = rhashtable_lookup(&tbl->rhead, dst, mesh_rht_params);
+
+ if (mpath && mpath_expired(mpath)) {
+ spin_lock_bh(&mpath->state_lock);
+ mpath->flags &= ~MESH_PATH_ACTIVE;
+ spin_unlock_bh(&mpath->state_lock);
+ }
+ return mpath;
+}
+
+/**
+ * mesh_path_lookup - look up a path in the mesh path table
+ * @sdata: local subif
+ * @dst: hardware address (ETH_ALEN length) of destination
+ *
+ * Returns: pointer to the mesh path structure, or NULL if not found
+ *
+ * Locking: must be called within a read rcu section.
+ */
+struct mesh_path *
+mesh_path_lookup(struct ieee80211_sub_if_data *sdata, const u8 *dst)
+{
+ return mpath_lookup(&sdata->u.mesh.mesh_paths, dst, sdata);
+}
+
+struct mesh_path *
+mpp_path_lookup(struct ieee80211_sub_if_data *sdata, const u8 *dst)
+{
+ return mpath_lookup(&sdata->u.mesh.mpp_paths, dst, sdata);
+}
+
+static struct mesh_path *
+__mesh_path_lookup_by_idx(struct mesh_table *tbl, int idx)
+{
+ int i = 0;
+ struct mesh_path *mpath;
+
+ hlist_for_each_entry_rcu(mpath, &tbl->walk_head, walk_list) {
+ if (i++ == idx)
+ break;
+ }
+
+ if (!mpath)
+ return NULL;
+
+ if (mpath_expired(mpath)) {
+ spin_lock_bh(&mpath->state_lock);
+ mpath->flags &= ~MESH_PATH_ACTIVE;
+ spin_unlock_bh(&mpath->state_lock);
+ }
+ return mpath;
+}
+
+/**
+ * mesh_path_lookup_by_idx - look up a path in the mesh path table by its index
+ * @idx: index
+ * @sdata: local subif, or NULL for all entries
+ *
+ * Returns: pointer to the mesh path structure, or NULL if not found.
+ *
+ * Locking: must be called within a read rcu section.
+ */
+struct mesh_path *
+mesh_path_lookup_by_idx(struct ieee80211_sub_if_data *sdata, int idx)
+{
+ return __mesh_path_lookup_by_idx(&sdata->u.mesh.mesh_paths, idx);
+}
+
+/**
+ * mpp_path_lookup_by_idx - look up a path in the proxy path table by its index
+ * @idx: index
+ * @sdata: local subif, or NULL for all entries
+ *
+ * Returns: pointer to the proxy path structure, or NULL if not found.
+ *
+ * Locking: must be called within a read rcu section.
+ */
+struct mesh_path *
+mpp_path_lookup_by_idx(struct ieee80211_sub_if_data *sdata, int idx)
+{
+ return __mesh_path_lookup_by_idx(&sdata->u.mesh.mpp_paths, idx);
+}
+
+/**
+ * mesh_path_add_gate - add the given mpath to a mesh gate to our path table
+ * @mpath: gate path to add to table
+ */
+int mesh_path_add_gate(struct mesh_path *mpath)
+{
+ struct mesh_table *tbl;
+ int err;
+
+ rcu_read_lock();
+ tbl = &mpath->sdata->u.mesh.mesh_paths;
+
+ spin_lock_bh(&mpath->state_lock);
+ if (mpath->is_gate) {
+ err = -EEXIST;
+ spin_unlock_bh(&mpath->state_lock);
+ goto err_rcu;
+ }
+ mpath->is_gate = true;
+ mpath->sdata->u.mesh.num_gates++;
+
+ spin_lock(&tbl->gates_lock);
+ hlist_add_head_rcu(&mpath->gate_list, &tbl->known_gates);
+ spin_unlock(&tbl->gates_lock);
+
+ spin_unlock_bh(&mpath->state_lock);
+
+ mpath_dbg(mpath->sdata,
+ "Mesh path: Recorded new gate: %pM. %d known gates\n",
+ mpath->dst, mpath->sdata->u.mesh.num_gates);
+ err = 0;
+err_rcu:
+ rcu_read_unlock();
+ return err;
+}
+
+/**
+ * mesh_gate_del - remove a mesh gate from the list of known gates
+ * @tbl: table which holds our list of known gates
+ * @mpath: gate mpath
+ */
+static void mesh_gate_del(struct mesh_table *tbl, struct mesh_path *mpath)
+{
+ lockdep_assert_held(&mpath->state_lock);
+ if (!mpath->is_gate)
+ return;
+
+ mpath->is_gate = false;
+ spin_lock_bh(&tbl->gates_lock);
+ hlist_del_rcu(&mpath->gate_list);
+ mpath->sdata->u.mesh.num_gates--;
+ spin_unlock_bh(&tbl->gates_lock);
+
+ mpath_dbg(mpath->sdata,
+ "Mesh path: Deleted gate: %pM. %d known gates\n",
+ mpath->dst, mpath->sdata->u.mesh.num_gates);
+}
+
+/**
+ * mesh_gate_num - number of gates known to this interface
+ * @sdata: subif data
+ */
+int mesh_gate_num(struct ieee80211_sub_if_data *sdata)
+{
+ return sdata->u.mesh.num_gates;
+}
+
+static
+struct mesh_path *mesh_path_new(struct ieee80211_sub_if_data *sdata,
+ const u8 *dst, gfp_t gfp_flags)
+{
+ struct mesh_path *new_mpath;
+
+ new_mpath = kzalloc(sizeof(struct mesh_path), gfp_flags);
+ if (!new_mpath)
+ return NULL;
+
+ memcpy(new_mpath->dst, dst, ETH_ALEN);
+ eth_broadcast_addr(new_mpath->rann_snd_addr);
+ new_mpath->is_root = false;
+ new_mpath->sdata = sdata;
+ new_mpath->flags = 0;
+ skb_queue_head_init(&new_mpath->frame_queue);
+ new_mpath->exp_time = jiffies;
+ spin_lock_init(&new_mpath->state_lock);
+ timer_setup(&new_mpath->timer, mesh_path_timer, 0);
+
+ return new_mpath;
+}
+
+/**
+ * mesh_path_add - allocate and add a new path to the mesh path table
+ * @dst: destination address of the path (ETH_ALEN length)
+ * @sdata: local subif
+ *
+ * Returns: 0 on success
+ *
+ * State: the initial state of the new path is set to 0
+ */
+struct mesh_path *mesh_path_add(struct ieee80211_sub_if_data *sdata,
+ const u8 *dst)
+{
+ struct mesh_table *tbl;
+ struct mesh_path *mpath, *new_mpath;
+
+ if (ether_addr_equal(dst, sdata->vif.addr))
+ /* never add ourselves as neighbours */
+ return ERR_PTR(-ENOTSUPP);
+
+ if (is_multicast_ether_addr(dst))
+ return ERR_PTR(-ENOTSUPP);
+
+ if (atomic_add_unless(&sdata->u.mesh.mpaths, 1, MESH_MAX_MPATHS) == 0)
+ return ERR_PTR(-ENOSPC);
+
+ new_mpath = mesh_path_new(sdata, dst, GFP_ATOMIC);
+ if (!new_mpath)
+ return ERR_PTR(-ENOMEM);
+
+ tbl = &sdata->u.mesh.mesh_paths;
+ spin_lock_bh(&tbl->walk_lock);
+ mpath = rhashtable_lookup_get_insert_fast(&tbl->rhead,
+ &new_mpath->rhash,
+ mesh_rht_params);
+ if (!mpath)
+ hlist_add_head(&new_mpath->walk_list, &tbl->walk_head);
+ spin_unlock_bh(&tbl->walk_lock);
+
+ if (mpath) {
+ kfree(new_mpath);
+
+ if (IS_ERR(mpath))
+ return mpath;
+
+ new_mpath = mpath;
+ }
+
+ sdata->u.mesh.mesh_paths_generation++;
+ return new_mpath;
+}
+
+int mpp_path_add(struct ieee80211_sub_if_data *sdata,
+ const u8 *dst, const u8 *mpp)
+{
+ struct mesh_table *tbl;
+ struct mesh_path *new_mpath;
+ int ret;
+
+ if (ether_addr_equal(dst, sdata->vif.addr))
+ /* never add ourselves as neighbours */
+ return -ENOTSUPP;
+
+ if (is_multicast_ether_addr(dst))
+ return -ENOTSUPP;
+
+ new_mpath = mesh_path_new(sdata, dst, GFP_ATOMIC);
+
+ if (!new_mpath)
+ return -ENOMEM;
+
+ memcpy(new_mpath->mpp, mpp, ETH_ALEN);
+ tbl = &sdata->u.mesh.mpp_paths;
+
+ spin_lock_bh(&tbl->walk_lock);
+ ret = rhashtable_lookup_insert_fast(&tbl->rhead,
+ &new_mpath->rhash,
+ mesh_rht_params);
+ if (!ret)
+ hlist_add_head_rcu(&new_mpath->walk_list, &tbl->walk_head);
+ spin_unlock_bh(&tbl->walk_lock);
+
+ if (ret)
+ kfree(new_mpath);
+
+ sdata->u.mesh.mpp_paths_generation++;
+ return ret;
+}
+
+
+/**
+ * mesh_plink_broken - deactivates paths and sends perr when a link breaks
+ *
+ * @sta: broken peer link
+ *
+ * This function must be called from the rate control algorithm if enough
+ * delivery errors suggest that a peer link is no longer usable.
+ */
+void mesh_plink_broken(struct sta_info *sta)
+{
+ struct ieee80211_sub_if_data *sdata = sta->sdata;
+ struct mesh_table *tbl = &sdata->u.mesh.mesh_paths;
+ static const u8 bcast[ETH_ALEN] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
+ struct mesh_path *mpath;
+
+ rcu_read_lock();
+ hlist_for_each_entry_rcu(mpath, &tbl->walk_head, walk_list) {
+ if (rcu_access_pointer(mpath->next_hop) == sta &&
+ mpath->flags & MESH_PATH_ACTIVE &&
+ !(mpath->flags & MESH_PATH_FIXED)) {
+ spin_lock_bh(&mpath->state_lock);
+ mpath->flags &= ~MESH_PATH_ACTIVE;
+ ++mpath->sn;
+ spin_unlock_bh(&mpath->state_lock);
+ mesh_path_error_tx(sdata,
+ sdata->u.mesh.mshcfg.element_ttl,
+ mpath->dst, mpath->sn,
+ WLAN_REASON_MESH_PATH_DEST_UNREACHABLE, bcast);
+ }
+ }
+ rcu_read_unlock();
+}
+
+static void mesh_path_free_rcu(struct mesh_table *tbl,
+ struct mesh_path *mpath)
+{
+ struct ieee80211_sub_if_data *sdata = mpath->sdata;
+
+ spin_lock_bh(&mpath->state_lock);
+ mpath->flags |= MESH_PATH_RESOLVING | MESH_PATH_DELETED;
+ mesh_gate_del(tbl, mpath);
+ spin_unlock_bh(&mpath->state_lock);
+ timer_shutdown_sync(&mpath->timer);
+ atomic_dec(&sdata->u.mesh.mpaths);
+ atomic_dec(&tbl->entries);
+ mesh_path_flush_pending(mpath);
+ kfree_rcu(mpath, rcu);
+}
+
+static void __mesh_path_del(struct mesh_table *tbl, struct mesh_path *mpath)
+{
+ hlist_del_rcu(&mpath->walk_list);
+ rhashtable_remove_fast(&tbl->rhead, &mpath->rhash, mesh_rht_params);
+ mesh_path_free_rcu(tbl, mpath);
+}
+
+/**
+ * mesh_path_flush_by_nexthop - Deletes mesh paths if their next hop matches
+ *
+ * @sta: mesh peer to match
+ *
+ * RCU notes: this function is called when a mesh plink transitions from
+ * PLINK_ESTAB to any other state, since PLINK_ESTAB state is the only one that
+ * allows path creation. This will happen before the sta can be freed (because
+ * sta_info_destroy() calls this) so any reader in a rcu read block will be
+ * protected against the plink disappearing.
+ */
+void mesh_path_flush_by_nexthop(struct sta_info *sta)
+{
+ struct ieee80211_sub_if_data *sdata = sta->sdata;
+ struct mesh_table *tbl = &sdata->u.mesh.mesh_paths;
+ struct mesh_path *mpath;
+ struct hlist_node *n;
+
+ spin_lock_bh(&tbl->walk_lock);
+ hlist_for_each_entry_safe(mpath, n, &tbl->walk_head, walk_list) {
+ if (rcu_access_pointer(mpath->next_hop) == sta)
+ __mesh_path_del(tbl, mpath);
+ }
+ spin_unlock_bh(&tbl->walk_lock);
+}
+
+static void mpp_flush_by_proxy(struct ieee80211_sub_if_data *sdata,
+ const u8 *proxy)
+{
+ struct mesh_table *tbl = &sdata->u.mesh.mpp_paths;
+ struct mesh_path *mpath;
+ struct hlist_node *n;
+
+ spin_lock_bh(&tbl->walk_lock);
+ hlist_for_each_entry_safe(mpath, n, &tbl->walk_head, walk_list) {
+ if (ether_addr_equal(mpath->mpp, proxy))
+ __mesh_path_del(tbl, mpath);
+ }
+ spin_unlock_bh(&tbl->walk_lock);
+}
+
+static void table_flush_by_iface(struct mesh_table *tbl)
+{
+ struct mesh_path *mpath;
+ struct hlist_node *n;
+
+ spin_lock_bh(&tbl->walk_lock);
+ hlist_for_each_entry_safe(mpath, n, &tbl->walk_head, walk_list) {
+ __mesh_path_del(tbl, mpath);
+ }
+ spin_unlock_bh(&tbl->walk_lock);
+}
+
+/**
+ * mesh_path_flush_by_iface - Deletes all mesh paths associated with a given iface
+ *
+ * This function deletes both mesh paths as well as mesh portal paths.
+ *
+ * @sdata: interface data to match
+ *
+ */
+void mesh_path_flush_by_iface(struct ieee80211_sub_if_data *sdata)
+{
+ table_flush_by_iface(&sdata->u.mesh.mesh_paths);
+ table_flush_by_iface(&sdata->u.mesh.mpp_paths);
+}
+
+/**
+ * table_path_del - delete a path from the mesh or mpp table
+ *
+ * @tbl: mesh or mpp path table
+ * @sdata: local subif
+ * @addr: dst address (ETH_ALEN length)
+ *
+ * Returns: 0 if successful
+ */
+static int table_path_del(struct mesh_table *tbl,
+ struct ieee80211_sub_if_data *sdata,
+ const u8 *addr)
+{
+ struct mesh_path *mpath;
+
+ spin_lock_bh(&tbl->walk_lock);
+ mpath = rhashtable_lookup_fast(&tbl->rhead, addr, mesh_rht_params);
+ if (!mpath) {
+ spin_unlock_bh(&tbl->walk_lock);
+ return -ENXIO;
+ }
+
+ __mesh_path_del(tbl, mpath);
+ spin_unlock_bh(&tbl->walk_lock);
+ return 0;
+}
+
+
+/**
+ * mesh_path_del - delete a mesh path from the table
+ *
+ * @addr: dst address (ETH_ALEN length)
+ * @sdata: local subif
+ *
+ * Returns: 0 if successful
+ */
+int mesh_path_del(struct ieee80211_sub_if_data *sdata, const u8 *addr)
+{
+ int err;
+
+ /* flush relevant mpp entries first */
+ mpp_flush_by_proxy(sdata, addr);
+
+ err = table_path_del(&sdata->u.mesh.mesh_paths, sdata, addr);
+ sdata->u.mesh.mesh_paths_generation++;
+ return err;
+}
+
+/**
+ * mesh_path_tx_pending - sends pending frames in a mesh path queue
+ *
+ * @mpath: mesh path to activate
+ *
+ * Locking: the state_lock of the mpath structure must NOT be held when calling
+ * this function.
+ */
+void mesh_path_tx_pending(struct mesh_path *mpath)
+{
+ if (mpath->flags & MESH_PATH_ACTIVE)
+ ieee80211_add_pending_skbs(mpath->sdata->local,
+ &mpath->frame_queue);
+}
+
+/**
+ * mesh_path_send_to_gates - sends pending frames to all known mesh gates
+ *
+ * @mpath: mesh path whose queue will be emptied
+ *
+ * If there is only one gate, the frames are transferred from the failed mpath
+ * queue to that gate's queue. If there are more than one gates, the frames
+ * are copied from each gate to the next. After frames are copied, the
+ * mpath queues are emptied onto the transmission queue.
+ */
+int mesh_path_send_to_gates(struct mesh_path *mpath)
+{
+ struct ieee80211_sub_if_data *sdata = mpath->sdata;
+ struct mesh_table *tbl;
+ struct mesh_path *from_mpath = mpath;
+ struct mesh_path *gate;
+ bool copy = false;
+
+ tbl = &sdata->u.mesh.mesh_paths;
+
+ rcu_read_lock();
+ hlist_for_each_entry_rcu(gate, &tbl->known_gates, gate_list) {
+ if (gate->flags & MESH_PATH_ACTIVE) {
+ mpath_dbg(sdata, "Forwarding to %pM\n", gate->dst);
+ mesh_path_move_to_queue(gate, from_mpath, copy);
+ from_mpath = gate;
+ copy = true;
+ } else {
+ mpath_dbg(sdata,
+ "Not forwarding to %pM (flags %#x)\n",
+ gate->dst, gate->flags);
+ }
+ }
+
+ hlist_for_each_entry_rcu(gate, &tbl->known_gates, gate_list) {
+ mpath_dbg(sdata, "Sending to %pM\n", gate->dst);
+ mesh_path_tx_pending(gate);
+ }
+ rcu_read_unlock();
+
+ return (from_mpath == mpath) ? -EHOSTUNREACH : 0;
+}
+
+/**
+ * mesh_path_discard_frame - discard a frame whose path could not be resolved
+ *
+ * @skb: frame to discard
+ * @sdata: network subif the frame was to be sent through
+ *
+ * Locking: the function must me called within a rcu_read_lock region
+ */
+void mesh_path_discard_frame(struct ieee80211_sub_if_data *sdata,
+ struct sk_buff *skb)
+{
+ ieee80211_free_txskb(&sdata->local->hw, skb);
+ sdata->u.mesh.mshstats.dropped_frames_no_route++;
+}
+
+/**
+ * mesh_path_flush_pending - free the pending queue of a mesh path
+ *
+ * @mpath: mesh path whose queue has to be freed
+ *
+ * Locking: the function must me called within a rcu_read_lock region
+ */
+void mesh_path_flush_pending(struct mesh_path *mpath)
+{
+ struct sk_buff *skb;
+
+ while ((skb = skb_dequeue(&mpath->frame_queue)) != NULL)
+ mesh_path_discard_frame(mpath->sdata, skb);
+}
+
+/**
+ * mesh_path_fix_nexthop - force a specific next hop for a mesh path
+ *
+ * @mpath: the mesh path to modify
+ * @next_hop: the next hop to force
+ *
+ * Locking: this function must be called holding mpath->state_lock
+ */
+void mesh_path_fix_nexthop(struct mesh_path *mpath, struct sta_info *next_hop)
+{
+ spin_lock_bh(&mpath->state_lock);
+ mesh_path_assign_nexthop(mpath, next_hop);
+ mpath->sn = 0xffff;
+ mpath->metric = 0;
+ mpath->hop_count = 0;
+ mpath->exp_time = 0;
+ mpath->flags = MESH_PATH_FIXED | MESH_PATH_SN_VALID;
+ mesh_path_activate(mpath);
+ spin_unlock_bh(&mpath->state_lock);
+ ewma_mesh_fail_avg_init(&next_hop->mesh->fail_avg);
+ /* init it at a low value - 0 start is tricky */
+ ewma_mesh_fail_avg_add(&next_hop->mesh->fail_avg, 1);
+ mesh_path_tx_pending(mpath);
+}
+
+void mesh_pathtbl_init(struct ieee80211_sub_if_data *sdata)
+{
+ mesh_table_init(&sdata->u.mesh.mesh_paths);
+ mesh_table_init(&sdata->u.mesh.mpp_paths);
+}
+
+static
+void mesh_path_tbl_expire(struct ieee80211_sub_if_data *sdata,
+ struct mesh_table *tbl)
+{
+ struct mesh_path *mpath;
+ struct hlist_node *n;
+
+ spin_lock_bh(&tbl->walk_lock);
+ hlist_for_each_entry_safe(mpath, n, &tbl->walk_head, walk_list) {
+ if ((!(mpath->flags & MESH_PATH_RESOLVING)) &&
+ (!(mpath->flags & MESH_PATH_FIXED)) &&
+ time_after(jiffies, mpath->exp_time + MESH_PATH_EXPIRE))
+ __mesh_path_del(tbl, mpath);
+ }
+ spin_unlock_bh(&tbl->walk_lock);
+}
+
+void mesh_path_expire(struct ieee80211_sub_if_data *sdata)
+{
+ mesh_path_tbl_expire(sdata, &sdata->u.mesh.mesh_paths);
+ mesh_path_tbl_expire(sdata, &sdata->u.mesh.mpp_paths);
+}
+
+void mesh_pathtbl_unregister(struct ieee80211_sub_if_data *sdata)
+{
+ mesh_table_free(&sdata->u.mesh.mesh_paths);
+ mesh_table_free(&sdata->u.mesh.mpp_paths);
+}