* [PATCH v5 1/4] net:ipv6:Add void *data to ndisc_send_na function
2022-03-21 8:47 [PATCH v5 0/4] Add support for IPV6 RLB to balance-alb mode Sun Shouxin
@ 2022-03-21 8:47 ` Sun Shouxin
2022-03-21 8:47 ` [PATCH v5 2/4] net:ipv6:Refactor ndisc_send_na to support sending na by slave directly Sun Shouxin
` (2 subsequent siblings)
3 siblings, 0 replies; 8+ messages in thread
From: Sun Shouxin @ 2022-03-21 8:47 UTC (permalink / raw)
To: j.vosburgh, vfalico, andy, davem, kuba, pabeni, yoshfuji, dsahern,
oliver
Cc: netdev, linux-kernel, huyd12, sunshouxin
Adds void *data to ndisc_send_na stub function and
ndisc_send_na direct function. Update all places that
use both ndisc_send_na to pass NULL as the data parameter.
Signed-off-by: Sun Shouxin <sunshouxin@chinatelecom.cn>
---
drivers/net/usb/cdc_mbim.c | 3 ++-
include/net/ipv6_stubs.h | 3 ++-
include/net/ndisc.h | 3 ++-
net/ipv6/addrconf.c | 2 +-
net/ipv6/ndisc.c | 9 +++++----
5 files changed, 12 insertions(+), 8 deletions(-)
diff --git a/drivers/net/usb/cdc_mbim.c b/drivers/net/usb/cdc_mbim.c
index c89639381eca..fa3869b214a9 100644
--- a/drivers/net/usb/cdc_mbim.c
+++ b/drivers/net/usb/cdc_mbim.c
@@ -347,7 +347,8 @@ static void do_neigh_solicit(struct usbnet *dev, u8 *buf, u16 tci)
is_router /* router */,
true /* solicited */,
false /* override */,
- true /* inc_opt */);
+ true /* inc_opt */,
+ NULL);
out:
dev_put(netdev);
}
diff --git a/include/net/ipv6_stubs.h b/include/net/ipv6_stubs.h
index 45e0339be6fa..2b64ea6590b6 100644
--- a/include/net/ipv6_stubs.h
+++ b/include/net/ipv6_stubs.h
@@ -56,7 +56,8 @@ struct ipv6_stub {
void (*udpv6_encap_enable)(void);
void (*ndisc_send_na)(struct net_device *dev, const struct in6_addr *daddr,
const struct in6_addr *solicited_addr,
- bool router, bool solicited, bool override, bool inc_opt);
+ bool router, bool solicited, bool override,
+ bool inc_opt, void *data);
#if IS_ENABLED(CONFIG_XFRM)
void (*xfrm6_local_rxpmtu)(struct sk_buff *skb, u32 mtu);
int (*xfrm6_udp_encap_rcv)(struct sock *sk, struct sk_buff *skb);
diff --git a/include/net/ndisc.h b/include/net/ndisc.h
index da7eec8669ec..24cf6e92fecc 100644
--- a/include/net/ndisc.h
+++ b/include/net/ndisc.h
@@ -460,7 +460,8 @@ void ndisc_send_rs(struct net_device *dev,
const struct in6_addr *saddr, const struct in6_addr *daddr);
void ndisc_send_na(struct net_device *dev, const struct in6_addr *daddr,
const struct in6_addr *solicited_addr,
- bool router, bool solicited, bool override, bool inc_opt);
+ bool router, bool solicited, bool override, bool inc_opt,
+ void *data);
void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target);
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index b22504176588..bb1912eacd90 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -4217,7 +4217,7 @@ static void addrconf_dad_completed(struct inet6_ifaddr *ifp, bool bump_id,
ndisc_send_na(dev, &in6addr_linklocal_allnodes, &ifp->addr,
/*router=*/ !!ifp->idev->cnf.forwarding,
/*solicited=*/ false, /*override=*/ true,
- /*inc_opt=*/ true);
+ /*inc_opt=*/ true, NULL);
}
if (send_rs) {
diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
index fcb288b0ae13..f7bd7082abb4 100644
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c
@@ -518,7 +518,8 @@ EXPORT_SYMBOL(ndisc_send_skb);
void ndisc_send_na(struct net_device *dev, const struct in6_addr *daddr,
const struct in6_addr *solicited_addr,
- bool router, bool solicited, bool override, bool inc_opt)
+ bool router, bool solicited, bool override, bool inc_opt,
+ void *data)
{
struct sk_buff *skb;
struct in6_addr tmpaddr;
@@ -591,7 +592,7 @@ static void ndisc_send_unsol_na(struct net_device *dev)
ndisc_send_na(dev, &in6addr_linklocal_allnodes, &ifa->addr,
/*router=*/ !!idev->cnf.forwarding,
/*solicited=*/ false, /*override=*/ true,
- /*inc_opt=*/ true);
+ /*inc_opt=*/ true, NULL);
}
read_unlock_bh(&idev->lock);
@@ -932,7 +933,7 @@ static void ndisc_recv_ns(struct sk_buff *skb)
if (dad) {
ndisc_send_na(dev, &in6addr_linklocal_allnodes, &msg->target,
- !!is_router, false, (ifp != NULL), true);
+ !!is_router, false, ifp, true, NULL);
goto out;
}
@@ -954,7 +955,7 @@ static void ndisc_recv_ns(struct sk_buff *skb)
NDISC_NEIGHBOUR_SOLICITATION, &ndopts);
if (neigh || !dev->header_ops) {
ndisc_send_na(dev, saddr, &msg->target, !!is_router,
- true, (ifp != NULL && inc), inc);
+ true, (ifp && inc), inc, NULL);
if (neigh)
neigh_release(neigh);
}
--
2.27.0
^ permalink raw reply related [flat|nested] 8+ messages in thread* [PATCH v5 2/4] net:ipv6:Refactor ndisc_send_na to support sending na by slave directly
2022-03-21 8:47 [PATCH v5 0/4] Add support for IPV6 RLB to balance-alb mode Sun Shouxin
2022-03-21 8:47 ` [PATCH v5 1/4] net:ipv6:Add void *data to ndisc_send_na function Sun Shouxin
@ 2022-03-21 8:47 ` Sun Shouxin
2022-03-21 8:47 ` [PATCH v5 3/4] net:ipv6:Export inet6_ifa_finish_destroy and ipv6_get_ifaddr Sun Shouxin
2022-03-21 8:47 ` [PATCH v5 4/4] net:bonding:Add support for IPV6 RLB to balance-alb mode Sun Shouxin
3 siblings, 0 replies; 8+ messages in thread
From: Sun Shouxin @ 2022-03-21 8:47 UTC (permalink / raw)
To: j.vosburgh, vfalico, andy, davem, kuba, pabeni, yoshfuji, dsahern,
oliver
Cc: netdev, linux-kernel, huyd12, sunshouxin
Refactor ndisc_send_na to support sending na by slave directly.
Signed-off-by: Sun Shouxin <sunshouxin@chinatelecom.cn>
---
include/net/ndisc.h | 6 +++++
net/ipv6/ndisc.c | 55 +++++++++++++++++++++++++++++++++------------
2 files changed, 47 insertions(+), 14 deletions(-)
diff --git a/include/net/ndisc.h b/include/net/ndisc.h
index 24cf6e92fecc..e71702a44a3d 100644
--- a/include/net/ndisc.h
+++ b/include/net/ndisc.h
@@ -107,6 +107,12 @@ struct nd_opt_hdr {
__u8 nd_opt_len;
} __packed;
+struct nd_sendinfo {
+ __u16 vlanid;
+ void *mac_dst;
+ const void *mac_src;
+};
+
/* ND options */
struct ndisc_options {
struct nd_opt_hdr *nd_opt_array[__ND_OPT_ARRAY_MAX];
diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
index f7bd7082abb4..47875aab86e5 100644
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c
@@ -526,22 +526,29 @@ void ndisc_send_na(struct net_device *dev, const struct in6_addr *daddr,
struct inet6_ifaddr *ifp;
const struct in6_addr *src_addr;
struct nd_msg *msg;
+ struct nd_sendinfo *sendinfo = data;
+ struct net *net = dev_net(dev);
+ struct sock *sk = net->ipv6.ndisc_sk;
int optlen = 0;
- /* for anycast or proxy, solicited_addr != src_addr */
- ifp = ipv6_get_ifaddr(dev_net(dev), solicited_addr, dev, 1);
- if (ifp) {
- src_addr = solicited_addr;
- if (ifp->flags & IFA_F_OPTIMISTIC)
- override = false;
- inc_opt |= ifp->idev->cnf.force_tllao;
- in6_ifa_put(ifp);
+ if (!sendinfo) {
+ /* for anycast or proxy, solicited_addr != src_addr */
+ ifp = ipv6_get_ifaddr(dev_net(dev), solicited_addr, dev, 1);
+ if (ifp) {
+ src_addr = solicited_addr;
+ if (ifp->flags & IFA_F_OPTIMISTIC)
+ override = false;
+ inc_opt |= ifp->idev->cnf.force_tllao;
+ in6_ifa_put(ifp);
+ } else {
+ if (ipv6_dev_get_saddr(dev_net(dev), dev, daddr,
+ inet6_sk(dev_net(dev)->ipv6.ndisc_sk)->srcprefs,
+ &tmpaddr))
+ return;
+ src_addr = &tmpaddr;
+ }
} else {
- if (ipv6_dev_get_saddr(dev_net(dev), dev, daddr,
- inet6_sk(dev_net(dev)->ipv6.ndisc_sk)->srcprefs,
- &tmpaddr))
- return;
- src_addr = &tmpaddr;
+ src_addr = solicited_addr;
}
if (!dev->addr_len)
@@ -569,8 +576,28 @@ void ndisc_send_na(struct net_device *dev, const struct in6_addr *daddr,
ndisc_fill_addr_option(skb, ND_OPT_TARGET_LL_ADDR,
dev->dev_addr,
NDISC_NEIGHBOUR_ADVERTISEMENT);
+ if (!sendinfo) {
+ ndisc_send_skb(skb, daddr, src_addr);
+ } else {
+ if (sendinfo->vlanid)
+ __vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q),
+ sendinfo->vlanid);
+
+ msg->icmph.icmp6_cksum = csum_ipv6_magic(src_addr, daddr, skb->len,
+ IPPROTO_ICMPV6,
+ csum_partial(&msg->icmph,
+ skb->len, 0));
- ndisc_send_skb(skb, daddr, src_addr);
+ ip6_nd_hdr(skb, src_addr, daddr, inet6_sk(sk)->hop_limit, skb->len);
+
+ skb->protocol = htons(ETH_P_IPV6);
+ skb->dev = dev;
+ if (dev_hard_header(skb, dev, ETH_P_IPV6, sendinfo->mac_dst,
+ sendinfo->mac_src, skb->len) < 0)
+ return;
+
+ dev_queue_xmit(skb);
+ }
}
static void ndisc_send_unsol_na(struct net_device *dev)
--
2.27.0
^ permalink raw reply related [flat|nested] 8+ messages in thread* [PATCH v5 4/4] net:bonding:Add support for IPV6 RLB to balance-alb mode
2022-03-21 8:47 [PATCH v5 0/4] Add support for IPV6 RLB to balance-alb mode Sun Shouxin
` (2 preceding siblings ...)
2022-03-21 8:47 ` [PATCH v5 3/4] net:ipv6:Export inet6_ifa_finish_destroy and ipv6_get_ifaddr Sun Shouxin
@ 2022-03-21 8:47 ` Sun Shouxin
2022-03-21 9:56 ` Jiri Pirko
` (2 more replies)
3 siblings, 3 replies; 8+ messages in thread
From: Sun Shouxin @ 2022-03-21 8:47 UTC (permalink / raw)
To: j.vosburgh, vfalico, andy, davem, kuba, pabeni, yoshfuji, dsahern,
oliver
Cc: netdev, linux-kernel, huyd12, sunshouxin
This patch is implementing IPV6 RLB for balance-alb mode.
Suggested-by: Hu Yadi <huyd12@chinatelecom.cn>
Signed-off-by: Sun Shouxin <sunshouxin@chinatelecom.cn>
---
Introduction:
This is like ipv4 rlb,ipv6 rlb uses ND to realize it.
I would show it through each function.
Add rx6_hashtbl in alb_bond_info to save ipv6 rlb client_info.
Add rx6_ntt,rx6_hashtbl_used_head,rlb6_update_delay_counter,
and rlb6_update_retry_counter in alb_bond_info to support ipv6 rlb update.
Add ip6_src and ip6_dst in rlb_client_info.
Add ipv6 rlb actions in bond_alb_monitor and rlb_rebalance.
rlb6_update_client:send na packet based client_info to update
the neighbour infomation in other host.
rlb6_update_rx_clients:send na packet based ntt
rlb6_delete_table_entry_dst:
rlb6_src_link:
rlb6_src_unlink:update rx6_hashtbl
rlb6_nd_choose_channel:choose tx_slave and update the client_info
rlb_nd_xmit:when sending ns and na packet,choose tx_slave packet
and update the client_info
rlb6_update_entry_from_na:update the client_info when receiving na
rlb6_delete_table_entry:delete client_info
rlb6_purge_src_ip:deletes all rx_hashtbl entries with ip_src if their
mac_src does not match lladdr
rlb_recv:as the recv_probe
rlb_nd_recv:receiving ns and na packet
---
drivers/net/bonding/bond_3ad.c | 2 +-
drivers/net/bonding/bond_alb.c | 592 ++++++++++++++++++++++++++++-
drivers/net/bonding/bond_debugfs.c | 14 +
drivers/net/bonding/bond_main.c | 6 +-
include/net/bond_3ad.h | 2 +-
include/net/bond_alb.h | 7 +
include/net/bonding.h | 6 +-
7 files changed, 615 insertions(+), 14 deletions(-)
diff --git a/drivers/net/bonding/bond_3ad.c b/drivers/net/bonding/bond_3ad.c
index a86b1f71762e..3cba269f12e2 100644
--- a/drivers/net/bonding/bond_3ad.c
+++ b/drivers/net/bonding/bond_3ad.c
@@ -2682,7 +2682,7 @@ int bond_3ad_get_active_agg_info(struct bonding *bond, struct ad_info *ad_info)
return ret;
}
-int bond_3ad_lacpdu_recv(const struct sk_buff *skb, struct bonding *bond,
+int bond_3ad_lacpdu_recv(struct sk_buff *skb, struct bonding *bond,
struct slave *slave)
{
struct lacpdu *lacpdu, _lacpdu;
diff --git a/drivers/net/bonding/bond_alb.c b/drivers/net/bonding/bond_alb.c
index 303c8d32d451..06a4557e00e3 100644
--- a/drivers/net/bonding/bond_alb.c
+++ b/drivers/net/bonding/bond_alb.c
@@ -23,6 +23,9 @@
#include <asm/byteorder.h>
#include <net/bonding.h>
#include <net/bond_alb.h>
+#include <net/addrconf.h>
+#include <net/ip6_checksum.h>
+#include <net/ipv6_stubs.h>
static const u8 mac_v6_allmcast[ETH_ALEN + 2] __long_aligned = {
0x33, 0x33, 0x00, 0x00, 0x00, 0x01
@@ -57,6 +60,13 @@ static void rlb_purge_src_ip(struct bonding *bond, struct arp_pkt *arp);
static void rlb_src_unlink(struct bonding *bond, u32 index);
static void rlb_src_link(struct bonding *bond, u32 ip_src_hash,
u32 ip_dst_hash);
+static void rlb6_delete_table_entry(struct bonding *bond, u32 index);
+static u8 *alb_get_lladdr(struct sk_buff *skb);
+static void alb_set_nd_option(struct sk_buff *skb, struct bonding *bond,
+ struct slave *tx_slave);
+static bool alb_determine_ipv6_nd(struct sk_buff *skb, struct bonding *bond);
+static int rlb_recv(struct sk_buff *skb, struct bonding *bond,
+ struct slave *slave);
static inline u8 _simple_hash(const u8 *hash_start, int hash_size)
{
@@ -269,7 +279,7 @@ static void rlb_update_entry_from_arp(struct bonding *bond, struct arp_pkt *arp)
spin_unlock_bh(&bond->mode_lock);
}
-static int rlb_arp_recv(const struct sk_buff *skb, struct bonding *bond,
+static int rlb_arp_recv(struct sk_buff *skb, struct bonding *bond,
struct slave *slave)
{
struct arp_pkt *arp, _arp;
@@ -415,6 +425,31 @@ static void rlb_clear_slave(struct bonding *bond, struct slave *slave)
}
}
+ rx_hash_table = bond_info->rx6_hashtbl;
+ index = bond_info->rx6_hashtbl_used_head;
+ for (; index != RLB_NULL_INDEX; index = next_index) {
+ next_index = rx_hash_table[index].used_next;
+ if (rx_hash_table[index].slave == slave) {
+ struct slave *assigned_slave = rlb_next_rx_slave(bond);
+
+ if (assigned_slave) {
+ u8 mac_dst[ETH_ALEN];
+
+ rx_hash_table[index].slave = assigned_slave;
+ memcpy(mac_dst, rx_hash_table[index].mac_dst,
+ sizeof(mac_dst));
+ if (is_valid_ether_addr(mac_dst)) {
+ bond_info->rx6_hashtbl[index].ntt = 1;
+ bond_info->rx6_ntt = 1;
+ bond_info->rlb6_update_retry_counter =
+ RLB_UPDATE_RETRY;
+ }
+ } else { /* there is no active slave */
+ rx_hash_table[index].slave = NULL;
+ }
+ }
+ }
+
spin_unlock_bh(&bond->mode_lock);
if (slave != rtnl_dereference(bond->curr_active_slave))
@@ -704,7 +739,7 @@ static void rlb_rebalance(struct bonding *bond)
struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
struct slave *assigned_slave;
struct rlb_client_info *client_info;
- int ntt;
+ int ntt, ntt_ip6;
u32 hash_index;
spin_lock_bh(&bond->mode_lock);
@@ -724,9 +759,27 @@ static void rlb_rebalance(struct bonding *bond)
}
}
+ ntt_ip6 = 0;
+ hash_index = bond_info->rx6_hashtbl_used_head;
+ for (; hash_index != RLB_NULL_INDEX;
+ hash_index = client_info->used_next) {
+ client_info = &bond_info->rx6_hashtbl[hash_index];
+ assigned_slave = __rlb_next_rx_slave(bond);
+ if (assigned_slave && client_info->slave != assigned_slave) {
+ client_info->slave = assigned_slave;
+ if (!is_zero_ether_addr(client_info->mac_dst)) {
+ client_info->ntt = 1;
+ ntt_ip6 = 1;
+ }
+ }
+ }
+
/* update the team's flag only after the whole iteration */
if (ntt)
bond_info->rx_ntt = 1;
+
+ if (ntt_ip6)
+ bond_info->rx6_ntt = 1;
spin_unlock_bh(&bond->mode_lock);
}
@@ -846,6 +899,7 @@ static int rlb_initialize(struct bonding *bond)
{
struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
struct rlb_client_info *new_hashtbl;
+ struct rlb_client_info *new6_hashtbl;
int size = RLB_HASH_TABLE_SIZE * sizeof(struct rlb_client_info);
int i;
@@ -853,19 +907,29 @@ static int rlb_initialize(struct bonding *bond)
if (!new_hashtbl)
return -1;
+ new6_hashtbl = kmalloc(size, GFP_KERNEL);
+ if (!new6_hashtbl) {
+ kfree(new_hashtbl);
+ return -1;
+ }
+
spin_lock_bh(&bond->mode_lock);
bond_info->rx_hashtbl = new_hashtbl;
+ bond_info->rx6_hashtbl = new6_hashtbl;
bond_info->rx_hashtbl_used_head = RLB_NULL_INDEX;
+ bond_info->rx6_hashtbl_used_head = RLB_NULL_INDEX;
- for (i = 0; i < RLB_HASH_TABLE_SIZE; i++)
+ for (i = 0; i < RLB_HASH_TABLE_SIZE; i++) {
rlb_init_table_entry(bond_info->rx_hashtbl + i);
+ rlb_init_table_entry(bond_info->rx6_hashtbl + i);
+ }
spin_unlock_bh(&bond->mode_lock);
/* register to receive ARPs */
- bond->recv_probe = rlb_arp_recv;
+ bond->recv_probe = rlb_recv;
return 0;
}
@@ -880,6 +944,10 @@ static void rlb_deinitialize(struct bonding *bond)
bond_info->rx_hashtbl = NULL;
bond_info->rx_hashtbl_used_head = RLB_NULL_INDEX;
+ kfree(bond_info->rx6_hashtbl);
+ bond_info->rx6_hashtbl = NULL;
+ bond_info->rx6_hashtbl_used_head = RLB_NULL_INDEX;
+
spin_unlock_bh(&bond->mode_lock);
}
@@ -901,9 +969,397 @@ static void rlb_clear_vlan(struct bonding *bond, unsigned short vlan_id)
curr_index = next_index;
}
+ curr_index = bond_info->rx6_hashtbl_used_head;
+ while (curr_index != RLB_NULL_INDEX) {
+ struct rlb_client_info *curr = &bond_info->rx6_hashtbl[curr_index];
+ u32 next_index = bond_info->rx6_hashtbl[curr_index].used_next;
+
+ if (curr->vlan_id == vlan_id)
+ rlb6_delete_table_entry(bond, curr_index);
+
+ curr_index = next_index;
+ }
+
+ spin_unlock_bh(&bond->mode_lock);
+}
+
+/*********************** ipv6 rlb specific functions ***************************/
+static void rlb6_update_client(struct rlb_client_info *client_info)
+{
+ struct nd_sendinfo sendinfo;
+ int i;
+
+ if (!client_info->slave || !is_valid_ether_addr(client_info->mac_dst))
+ return;
+
+ sendinfo.vlanid = client_info->vlan_id;
+ sendinfo.mac_dst = client_info->mac_dst;
+ sendinfo.mac_src = client_info->slave->dev->dev_addr;
+
+ for (i = 0; i < RLB_ARP_BURST_SIZE; i++) {
+ ipv6_stub->ndisc_send_na(client_info->slave->dev,
+ &client_info->ip6_dst,
+ &client_info->ip6_src,
+ false, false, true, true,
+ &sendinfo);
+ }
+}
+
+static void rlb6_update_rx_clients(struct bonding *bond)
+{
+ struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
+ struct rlb_client_info *client_info;
+ u32 hash_index;
+
+ spin_lock_bh(&bond->mode_lock);
+
+ hash_index = bond_info->rx6_hashtbl_used_head;
+ for (; hash_index != RLB_NULL_INDEX;
+ hash_index = client_info->used_next) {
+ client_info = &bond_info->rx6_hashtbl[hash_index];
+ if (client_info->ntt) {
+ rlb6_update_client(client_info);
+ if (bond_info->rlb6_update_retry_counter == 0)
+ client_info->ntt = 0;
+ }
+ }
+
+ bond_info->rlb6_update_delay_counter = RLB_UPDATE_DELAY;
+
+ spin_unlock_bh(&bond->mode_lock);
+}
+
+static void rlb6_delete_table_entry_dst(struct bonding *bond, u32 index)
+{
+ struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
+ u32 next_index = bond_info->rx6_hashtbl[index].used_next;
+ u32 prev_index = bond_info->rx6_hashtbl[index].used_prev;
+
+ if (index == bond_info->rx6_hashtbl_used_head)
+ bond_info->rx6_hashtbl_used_head = next_index;
+
+ if (next_index != RLB_NULL_INDEX)
+ bond_info->rx6_hashtbl[next_index].used_prev = prev_index;
+
+ if (prev_index != RLB_NULL_INDEX)
+ bond_info->rx6_hashtbl[prev_index].used_next = next_index;
+}
+
+static void rlb6_src_link(struct bonding *bond, u32 ip_src_hash,
+ u32 ip_dst_hash)
+{
+ struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
+ u32 next;
+
+ bond_info->rx6_hashtbl[ip_dst_hash].src_prev = ip_src_hash;
+ next = bond_info->rx6_hashtbl[ip_src_hash].src_first;
+ bond_info->rx6_hashtbl[ip_dst_hash].src_next = next;
+ if (next != RLB_NULL_INDEX)
+ bond_info->rx6_hashtbl[next].src_prev = ip_dst_hash;
+ bond_info->rx6_hashtbl[ip_src_hash].src_first = ip_dst_hash;
+}
+
+static void rlb6_src_unlink(struct bonding *bond, u32 index)
+{
+ struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
+ u32 next_index = bond_info->rx6_hashtbl[index].src_next;
+ u32 prev_index = bond_info->rx6_hashtbl[index].src_prev;
+
+ bond_info->rx6_hashtbl[index].src_next = RLB_NULL_INDEX;
+ bond_info->rx6_hashtbl[index].src_prev = RLB_NULL_INDEX;
+
+ if (next_index != RLB_NULL_INDEX)
+ bond_info->rx6_hashtbl[next_index].src_prev = prev_index;
+
+ if (prev_index == RLB_NULL_INDEX)
+ return;
+
+ if (bond_info->rx6_hashtbl[prev_index].src_first == index)
+ bond_info->rx6_hashtbl[prev_index].src_first = next_index;
+ else
+ bond_info->rx6_hashtbl[prev_index].src_next = next_index;
+}
+
+static void rlb6_req_update_slave_clients(struct bonding *bond,
+ struct slave *slave)
+{
+ struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
+ struct rlb_client_info *client_info;
+ u32 hash_index;
+ int ntt = 0;
+
+ spin_lock_bh(&bond->mode_lock);
+
+ hash_index = bond_info->rx6_hashtbl_used_head;
+ for (; hash_index != RLB_NULL_INDEX;
+ hash_index = client_info->used_next) {
+ client_info = &bond_info->rx6_hashtbl[hash_index];
+ if (client_info->slave == slave &&
+ is_valid_ether_addr(client_info->mac_dst)) {
+ client_info->ntt = 1;
+ ntt = 1;
+ }
+ }
+
+ if (ntt) {
+ bond_info->rx6_ntt = 1;
+ bond_info->rlb6_update_retry_counter =
+ RLB_UPDATE_RETRY;
+ }
+ spin_unlock_bh(&bond->mode_lock);
+}
+
+static struct slave *rlb6_nd_choose_channel(struct sk_buff *skb,
+ struct bonding *bond,
+ struct ipv6hdr *ip6hdr,
+ u8 type)
+{
+ struct nd_msg *msg;
+ struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
+ struct slave *assigned_slave, *curr_active_slave;
+ struct rlb_client_info *client_info;
+ struct ethhdr *eth_data;
+ u8 *dst_ip;
+ u32 hash_index = 0;
+
+ spin_lock(&bond->mode_lock);
+
+ msg = (struct nd_msg *)skb_transport_header(skb);
+ eth_data = eth_hdr(skb);
+ curr_active_slave = rcu_dereference(bond->curr_active_slave);
+
+ if (type == NDISC_NEIGHBOUR_SOLICITATION)
+ dst_ip = (u8 *)msg->target.s6_addr;
+ else
+ dst_ip = (u8 *)ip6hdr->daddr.s6_addr;
+
+ hash_index = _simple_hash(dst_ip,
+ sizeof(struct in6_addr));
+ client_info = &bond_info->rx6_hashtbl[hash_index];
+
+ if (client_info->assigned) {
+ if (!memcmp(client_info->ip6_dst.s6_addr, dst_ip,
+ sizeof(struct in6_addr)) &&
+ !memcmp(client_info->ip6_src.s6_addr,
+ ip6hdr->saddr.s6_addr,
+ sizeof(ip6hdr->saddr.s6_addr))) {
+ ether_addr_copy(client_info->mac_src,
+ eth_data->h_source);
+
+ assigned_slave = client_info->slave;
+ if (assigned_slave) {
+ spin_unlock(&bond->mode_lock);
+ return assigned_slave;
+ }
+ } else {
+ if (curr_active_slave &&
+ curr_active_slave != client_info->slave) {
+ client_info->slave = curr_active_slave;
+ rlb6_update_client(client_info);
+ }
+ }
+ }
+
+ /* assign a new slave */
+ assigned_slave = __rlb_next_rx_slave(bond);
+
+ if (assigned_slave) {
+ if (!(client_info->assigned &&
+ !memcmp(client_info->ip6_src.s6_addr,
+ ip6hdr->saddr.s6_addr, sizeof(ip6hdr->saddr.s6_addr)))) {
+ u32 hash_src = _simple_hash((u8 *)ip6hdr->saddr.s6_addr,
+ sizeof(ip6hdr->saddr.s6_addr));
+
+ rlb6_src_unlink(bond, hash_index);
+ rlb6_src_link(bond, hash_src, hash_index);
+ }
+
+ memcpy(client_info->ip6_src.s6_addr, ip6hdr->saddr.s6_addr,
+ sizeof(ip6hdr->saddr.s6_addr));
+ memcpy(client_info->ip6_dst.s6_addr, dst_ip,
+ sizeof(struct in6_addr));
+
+ ether_addr_copy(client_info->mac_dst, eth_data->h_dest);
+ ether_addr_copy(client_info->mac_src, eth_data->h_source);
+
+ client_info->slave = assigned_slave;
+
+ if (is_valid_ether_addr(client_info->mac_dst)) {
+ client_info->ntt = 1;
+ bond->alb_info.rx6_ntt = 1;
+ } else {
+ client_info->ntt = 0;
+ }
+
+ if (vlan_get_tag(skb, &client_info->vlan_id))
+ client_info->vlan_id = 0;
+
+ if (!client_info->assigned) {
+ u32 prev_tbl_head = bond_info->rx6_hashtbl_used_head;
+
+ bond_info->rx6_hashtbl_used_head = hash_index;
+ client_info->used_next = prev_tbl_head;
+ if (prev_tbl_head != RLB_NULL_INDEX)
+ bond_info->rx6_hashtbl[prev_tbl_head].used_prev = hash_index;
+ client_info->assigned = 1;
+ }
+ }
+
+ spin_unlock(&bond->mode_lock);
+
+ return assigned_slave;
+}
+
+static struct slave *rlb_nd_xmit(struct sk_buff *skb, struct bonding *bond)
+{
+ struct slave *tx_slave = NULL;
+ struct ipv6hdr *ip6hdr;
+ struct icmp6hdr *hdr;
+ u8 *lladdr;
+
+ if (!pskb_network_may_pull(skb, sizeof(*ip6hdr)))
+ return NULL;
+
+ ip6hdr = ipv6_hdr(skb);
+ if (ip6hdr->nexthdr != IPPROTO_ICMPV6)
+ return NULL;
+
+ if (!pskb_network_may_pull(skb, sizeof(*ip6hdr) + sizeof(*hdr)))
+ return NULL;
+
+ hdr = icmp6_hdr(skb);
+
+ if (hdr->icmp6_type != NDISC_NEIGHBOUR_ADVERTISEMENT &&
+ hdr->icmp6_type != NDISC_NEIGHBOUR_SOLICITATION) {
+ return NULL;
+ }
+
+ lladdr = alb_get_lladdr(skb);
+ if (!lladdr)
+ return NULL;
+
+ if (!bond_slave_has_mac_rx(bond, lladdr)) {
+ tx_slave = rcu_dereference(bond->curr_active_slave);
+ return tx_slave;
+ }
+
+ tx_slave = rlb6_nd_choose_channel(skb, bond, ip6hdr, hdr->icmp6_type);
+ if (!tx_slave)
+ return NULL;
+
+ alb_set_nd_option(skb, bond, tx_slave);
+
+ return tx_slave;
+}
+
+static void rlb6_update_entry_from_na(struct bonding *bond,
+ struct ipv6hdr *ip6hdr, u8 *lladdr)
+{
+ struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
+ struct rlb_client_info *client_info;
+ u32 hash_index;
+
+ spin_lock_bh(&bond->mode_lock);
+
+ hash_index = _simple_hash(ip6hdr->saddr.s6_addr,
+ sizeof(ip6hdr->saddr.s6_addr));
+ client_info = &bond_info->rx6_hashtbl[hash_index];
+
+ if (client_info->assigned &&
+ !memcmp(ip6hdr->saddr.s6_addr, client_info->ip6_dst.s6_addr,
+ sizeof(ip6hdr->saddr.s6_addr)) && !memcmp(ip6hdr->daddr.s6_addr,
+ client_info->ip6_src.s6_addr, sizeof(ip6hdr->daddr.s6_addr)) &&
+ !ether_addr_equal_64bits(client_info->mac_dst, lladdr)) {
+ memcpy(client_info->mac_dst, lladdr,
+ sizeof(client_info->mac_dst));
+ }
spin_unlock_bh(&bond->mode_lock);
}
+static void rlb6_delete_table_entry(struct bonding *bond, u32 index)
+{
+ struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
+ struct rlb_client_info *entry = &bond_info->rx_hashtbl[index];
+
+ rlb6_delete_table_entry_dst(bond, index);
+ rlb_init_table_entry_dst(entry);
+ rlb6_src_unlink(bond, index);
+}
+
+static void rlb6_purge_src_ip(struct bonding *bond, struct ipv6hdr *ip6hdr,
+ u8 *lladdr)
+{
+ struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
+ struct rlb_client_info *client_info;
+ u32 ip_src_hash = _simple_hash((u8 *)ip6hdr->saddr.s6_addr,
+ sizeof(ip6hdr->saddr.s6_addr));
+ u32 index, next_index;
+
+ spin_lock_bh(&bond->mode_lock);
+
+ index = bond_info->rx6_hashtbl[ip_src_hash].src_first;
+ while (index != RLB_NULL_INDEX) {
+ client_info = &bond_info->rx6_hashtbl[index];
+ next_index = client_info->src_next;
+
+ if (!memcmp(client_info->ip6_src.s6_addr,
+ ip6hdr->saddr.s6_addr,
+ sizeof(ip6hdr->saddr.s6_addr)) &&
+ !ether_addr_equal_64bits(lladdr,
+ client_info->mac_src))
+ rlb6_delete_table_entry(bond, index);
+ index = next_index;
+ }
+
+ spin_unlock_bh(&bond->mode_lock);
+}
+
+static int rlb_nd_recv(struct sk_buff *skb, struct bonding *bond)
+{
+ struct ipv6hdr *ip6hdr;
+ struct nd_msg *msg;
+ struct inet6_ifaddr *ifp;
+ u8 *lladdr;
+
+ if (!pskb_network_may_pull(skb, sizeof(*ip6hdr)))
+ return RX_HANDLER_ANOTHER;
+
+ ip6hdr = ipv6_hdr(skb);
+
+ ifp = ipv6_get_ifaddr(dev_net(skb->dev), &ip6hdr->saddr, NULL, 0);
+ if (ifp) {
+ in6_ifa_put(ifp);
+ return RX_HANDLER_ANOTHER;
+ }
+
+ if (!pskb_network_may_pull(skb, sizeof(struct ipv6hdr) +
+ sizeof(struct nd_msg)))
+ return RX_HANDLER_ANOTHER;
+
+ msg = (struct nd_msg *)skb_transport_header(skb);
+ lladdr = alb_get_lladdr(skb);
+ if (!lladdr)
+ return RX_HANDLER_ANOTHER;
+
+ rlb6_purge_src_ip(bond, ip6hdr, lladdr);
+
+ if (msg->icmph.icmp6_type == NDISC_NEIGHBOUR_ADVERTISEMENT)
+ rlb6_update_entry_from_na(bond, ip6hdr, lladdr);
+
+ return RX_HANDLER_ANOTHER;
+}
+
+static int rlb_recv(struct sk_buff *skb, struct bonding *bond,
+ struct slave *slave)
+{
+ if (skb->protocol == cpu_to_be16(ETH_P_ARP))
+ return rlb_arp_recv(skb, bond, slave);
+ else if (alb_determine_ipv6_nd(skb, bond))
+ return rlb_nd_recv(skb, bond);
+
+ return RX_HANDLER_ANOTHER;
+}
+
/*********************** tlb/rlb shared functions *********************/
static void alb_send_lp_vid(struct slave *slave, const u8 mac_addr[],
@@ -1068,6 +1524,7 @@ static void alb_fasten_mac_swap(struct bonding *bond, struct slave *slave1,
* has changed
*/
rlb_req_update_slave_clients(bond, slave1);
+ rlb6_req_update_slave_clients(bond, slave1);
}
} else {
disabled_slave = slave1;
@@ -1080,6 +1537,7 @@ static void alb_fasten_mac_swap(struct bonding *bond, struct slave *slave1,
* has changed
*/
rlb_req_update_slave_clients(bond, slave2);
+ rlb6_req_update_slave_clients(bond, slave2);
}
} else {
disabled_slave = slave2;
@@ -1291,6 +1749,111 @@ static bool alb_determine_nd(struct sk_buff *skb, struct bonding *bond)
hdr->icmp6_type == NDISC_NEIGHBOUR_SOLICITATION;
}
+static bool alb_determine_ipv6_nd(struct sk_buff *skb, struct bonding *bond)
+{
+ if (skb->protocol == htons(ETH_P_IPV6)) {
+ if (skb_vlan_tag_present(skb))
+ skb->transport_header = skb->network_header + sizeof(struct ipv6hdr);
+ return alb_determine_nd(skb, bond);
+ }
+
+ return false;
+}
+
+static void alb_change_nd_option(struct sk_buff *skb, const void *data)
+{
+ struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
+ struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)msg->opt;
+ struct net_device *dev = skb->dev;
+ struct icmp6hdr *icmp6h = icmp6_hdr(skb);
+ struct ipv6hdr *ip6hdr = ipv6_hdr(skb);
+ u8 *lladdr = NULL;
+ u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
+ offsetof(struct nd_msg, opt));
+
+ while (ndoptlen) {
+ int l;
+
+ switch (nd_opt->nd_opt_type) {
+ case ND_OPT_SOURCE_LL_ADDR:
+ case ND_OPT_TARGET_LL_ADDR:
+ lladdr = ndisc_opt_addr_data(nd_opt, dev);
+ break;
+
+ default:
+ lladdr = NULL;
+ break;
+ }
+
+ l = nd_opt->nd_opt_len << 3;
+
+ if (ndoptlen < l || l == 0)
+ return;
+
+ if (lladdr) {
+ memcpy(lladdr, data, dev->addr_len);
+ icmp6h->icmp6_cksum = 0;
+
+ icmp6h->icmp6_cksum = csum_ipv6_magic(&ip6hdr->saddr,
+ &ip6hdr->daddr,
+ ntohs(ip6hdr->payload_len),
+ IPPROTO_ICMPV6,
+ csum_partial(icmp6h,
+ ntohs(ip6hdr->payload_len),
+ 0));
+ return;
+ }
+ ndoptlen -= l;
+ nd_opt = ((void *)nd_opt) + l;
+ }
+}
+
+static u8 *alb_get_lladdr(struct sk_buff *skb)
+{
+ struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
+ struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)msg->opt;
+ struct net_device *dev = skb->dev;
+ u8 *lladdr = NULL;
+ u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
+ offsetof(struct nd_msg, opt));
+
+ while (ndoptlen) {
+ int l;
+
+ switch (nd_opt->nd_opt_type) {
+ case ND_OPT_SOURCE_LL_ADDR:
+ case ND_OPT_TARGET_LL_ADDR:
+ lladdr = ndisc_opt_addr_data(nd_opt, dev);
+ break;
+
+ default:
+ break;
+ }
+
+ l = nd_opt->nd_opt_len << 3;
+
+ if (ndoptlen < l || l == 0)
+ return NULL;
+
+ if (lladdr)
+ return lladdr;
+
+ ndoptlen -= l;
+ nd_opt = ((void *)nd_opt) + l;
+ }
+
+ return lladdr;
+}
+
+static void alb_set_nd_option(struct sk_buff *skb, struct bonding *bond,
+ struct slave *tx_slave)
+{
+ if (tx_slave != rcu_access_pointer(bond->curr_active_slave)) {
+ if (alb_determine_nd(skb, bond))
+ alb_change_nd_option(skb, tx_slave->dev->dev_addr);
+ }
+}
+
/************************ exported alb functions ************************/
int bond_alb_initialize(struct bonding *bond, int rlb_enabled)
@@ -1457,12 +2020,17 @@ struct slave *bond_xmit_alb_slave_get(struct bonding *bond,
break;
}
- if (alb_determine_nd(skb, bond)) {
+ tx_slave = rlb_nd_xmit(skb, bond);
+ if (tx_slave) {
+ do_tx_balance = false;
+ break;
+ }
+
+ if (!pskb_network_may_pull(skb, sizeof(*ip6hdr))) {
do_tx_balance = false;
break;
}
- /* The IPv6 header is pulled by alb_determine_nd */
/* Additionally, DAD probes should not be tx-balanced as that
* will lead to false positives for duplicate addresses and
* prevent address configuration from working.
@@ -1612,6 +2180,17 @@ void bond_alb_monitor(struct work_struct *work)
bond_info->rx_ntt = 0;
}
}
+ if (bond_info->rx6_ntt) {
+ if (bond_info->rlb6_update_delay_counter) {
+ --bond_info->rlb6_update_delay_counter;
+ } else {
+ rlb6_update_rx_clients(bond);
+ if (bond_info->rlb6_update_retry_counter)
+ --bond_info->rlb6_update_retry_counter;
+ else
+ bond_info->rx6_ntt = 0;
+ }
+ }
}
rcu_read_unlock();
re_arm:
@@ -1812,6 +2391,7 @@ int bond_alb_set_mac_address(struct net_device *bond_dev, void *addr)
if (bond->alb_info.rlb_enabled) {
/* inform clients mac address has changed */
rlb_req_update_slave_clients(bond, curr_active);
+ rlb6_req_update_slave_clients(bond, curr_active);
}
}
diff --git a/drivers/net/bonding/bond_debugfs.c b/drivers/net/bonding/bond_debugfs.c
index 4f9b4a18c74c..90e88ff9b2bf 100644
--- a/drivers/net/bonding/bond_debugfs.c
+++ b/drivers/net/bonding/bond_debugfs.c
@@ -41,6 +41,20 @@ static int bond_debug_rlb_hash_show(struct seq_file *m, void *v)
client_info->slave->dev->name);
}
+ seq_puts(m, "SourceIP DestinationIP Destination MAC Src MAC DEV\n");
+
+ hash_index = bond_info->rx6_hashtbl_used_head;
+ for (; hash_index != RLB_NULL_INDEX;
+ hash_index = client_info->used_next) {
+ client_info = &bond_info->rx6_hashtbl[hash_index];
+ seq_printf(m, "%-40pI6 %-40pI6 %-17pM %-17pM %s\n",
+ &client_info->ip6_src,
+ &client_info->ip6_dst,
+ &client_info->mac_dst,
+ &client_info->mac_src,
+ client_info->slave->dev->name);
+ }
+
spin_unlock_bh(&bond->mode_lock);
return 0;
diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index 15eddca7b4b6..b6252b181940 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -1510,8 +1510,8 @@ static rx_handler_result_t bond_handle_frame(struct sk_buff **pskb)
struct sk_buff *skb = *pskb;
struct slave *slave;
struct bonding *bond;
- int (*recv_probe)(const struct sk_buff *, struct bonding *,
- struct slave *);
+ int (*recv_probe)(struct sk_buff *skb, struct bonding *bond,
+ struct slave *slave);
int ret = RX_HANDLER_ANOTHER;
skb = skb_share_check(skb, GFP_ATOMIC);
@@ -3228,7 +3228,7 @@ static int bond_na_rcv(const struct sk_buff *skb, struct bonding *bond,
}
#endif
-int bond_rcv_validate(const struct sk_buff *skb, struct bonding *bond,
+int bond_rcv_validate(struct sk_buff *skb, struct bonding *bond,
struct slave *slave)
{
#if IS_ENABLED(CONFIG_IPV6)
diff --git a/include/net/bond_3ad.h b/include/net/bond_3ad.h
index 184105d68294..51886d9c928d 100644
--- a/include/net/bond_3ad.h
+++ b/include/net/bond_3ad.h
@@ -300,7 +300,7 @@ void bond_3ad_handle_link_change(struct slave *slave, char link);
int bond_3ad_get_active_agg_info(struct bonding *bond, struct ad_info *ad_info);
int __bond_3ad_get_active_agg_info(struct bonding *bond,
struct ad_info *ad_info);
-int bond_3ad_lacpdu_recv(const struct sk_buff *skb, struct bonding *bond,
+int bond_3ad_lacpdu_recv(struct sk_buff *skb, struct bonding *bond,
struct slave *slave);
int bond_3ad_set_carrier(struct bonding *bond);
void bond_3ad_update_lacp_active(struct bonding *bond);
diff --git a/include/net/bond_alb.h b/include/net/bond_alb.h
index 191c36afa1f4..b1a572eead31 100644
--- a/include/net/bond_alb.h
+++ b/include/net/bond_alb.h
@@ -94,6 +94,8 @@ struct tlb_client_info {
struct rlb_client_info {
__be32 ip_src; /* the server IP address */
__be32 ip_dst; /* the client IP address */
+ struct in6_addr ip6_src;
+ struct in6_addr ip6_dst;
u8 mac_src[ETH_ALEN]; /* the server MAC address */
u8 mac_dst[ETH_ALEN]; /* the client MAC address */
@@ -131,10 +133,13 @@ struct alb_bond_info {
/* -------- rlb parameters -------- */
int rlb_enabled;
struct rlb_client_info *rx_hashtbl; /* Receive hash table */
+ struct rlb_client_info *rx6_hashtbl; /* Receive hash table */
u32 rx_hashtbl_used_head;
+ u32 rx6_hashtbl_used_head;
u8 rx_ntt; /* flag - need to transmit
* to all rx clients
*/
+ u8 rx6_ntt;
struct slave *rx_slave;/* last slave to xmit from */
u8 primary_is_promisc; /* boolean */
u32 rlb_promisc_timeout_counter;/* counts primary
@@ -144,6 +149,8 @@ struct alb_bond_info {
u32 rlb_update_retry_counter;/* counter of retries
* of client update
*/
+ u32 rlb6_update_delay_counter;
+ u32 rlb6_update_retry_counter;
u8 rlb_rebalance; /* flag - indicates that the
* rx traffic should be
* rebalanced
diff --git a/include/net/bonding.h b/include/net/bonding.h
index b14f4c0b4e9e..552bce0168d1 100644
--- a/include/net/bonding.h
+++ b/include/net/bonding.h
@@ -220,8 +220,8 @@ struct bonding {
struct bond_up_slave __rcu *all_slaves;
bool force_primary;
s32 slave_cnt; /* never change this value outside the attach/detach wrappers */
- int (*recv_probe)(const struct sk_buff *, struct bonding *,
- struct slave *);
+ int (*recv_probe)(struct sk_buff *skb, struct bonding *bond,
+ struct slave *slave);
/* mode_lock is used for mode-specific locking needs, currently used by:
* 3ad mode (4) - protect against running bond_3ad_unbind_slave() and
* bond_3ad_state_machine_handler() concurrently and also
@@ -639,7 +639,7 @@ struct bond_net {
struct class_attribute class_attr_bonding_masters;
};
-int bond_rcv_validate(const struct sk_buff *skb, struct bonding *bond, struct slave *slave);
+int bond_rcv_validate(struct sk_buff *skb, struct bonding *bond, struct slave *slave);
netdev_tx_t bond_dev_queue_xmit(struct bonding *bond, struct sk_buff *skb, struct net_device *slave_dev);
int bond_create(struct net *net, const char *name);
int bond_create_sysfs(struct bond_net *net);
--
2.27.0
^ permalink raw reply related [flat|nested] 8+ messages in thread