Commit a815bde5 authored by Jussi Maki's avatar Jussi Maki Committed by Daniel Borkmann
Browse files

net, bonding: Refactor bond_xmit_hash for use with xdp_buff 



In preparation for adding XDP support to the bonding driver
refactor the packet hashing functions to be able to work with
any linear data buffer without an skb.

Signed-off-by: default avatarJussi Maki <joamaki@gmail.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Cc: Jay Vosburgh <j.vosburgh@gmail.com>
Cc: Veaceslav Falico <vfalico@gmail.com>
Cc: Andy Gospodarek <andy@greyhouse.net>
Link: https://lore.kernel.org/bpf/20210731055738.16820-2-joamaki@gmail.com
parent c83ae15d

drivers/net/bonding/bond_main.c

+90 −57
Original line number Diff line number Diff line
@@ -3614,55 +3614,80 @@ static struct notifier_block bond_netdev_notifier = { 


/*---------------------------- Hashing Policies -----------------------------*/



/* Helper to access data in a packet, with or without a backing skb.

 * If skb is given the data is linearized if necessary via pskb_may_pull.

 */

static inline const void *bond_pull_data(struct sk_buff *skb,

					 const void *data, int hlen, int n)

{

	if (likely(n <= hlen))

		return data;

	else if (skb && likely(pskb_may_pull(skb, n)))

		return skb->head;



	return NULL;

}



/* L2 hash helper */

static inline u32 bond_eth_hash(struct sk_buff *skb)

static inline u32 bond_eth_hash(struct sk_buff *skb, const void *data, int mhoff, int hlen)

{

	struct ethhdr *ep, hdr_tmp;

	struct ethhdr *ep;



	ep = skb_header_pointer(skb, 0, sizeof(hdr_tmp), &hdr_tmp);

	if (ep)

		return ep->h_dest[5] ^ ep->h_source[5] ^ ep->h_proto;

	data = bond_pull_data(skb, data, hlen, mhoff + sizeof(struct ethhdr));

	if (!data)

		return 0;



	ep = (struct ethhdr *)(data + mhoff);

	return ep->h_dest[5] ^ ep->h_source[5] ^ ep->h_proto;

}



static bool bond_flow_ip(struct sk_buff *skb, struct flow_keys *fk,

			 int *noff, int *proto, bool l34)

static bool bond_flow_ip(struct sk_buff *skb, struct flow_keys *fk, const void *data,

			 int hlen, __be16 l2_proto, int *nhoff, int *ip_proto, bool l34)

{

	const struct ipv6hdr *iph6;

	const struct iphdr *iph;



	if (skb->protocol == htons(ETH_P_IP)) {

		if (unlikely(!pskb_may_pull(skb, *noff + sizeof(*iph))))

	if (l2_proto == htons(ETH_P_IP)) {

		data = bond_pull_data(skb, data, hlen, *nhoff + sizeof(*iph));

		if (!data)

			return false;

		iph = (const struct iphdr *)(skb->data + *noff);



		iph = (const struct iphdr *)(data + *nhoff);

		iph_to_flow_copy_v4addrs(fk, iph);

		*noff += iph->ihl << 2;

		*nhoff += iph->ihl << 2;

		if (!ip_is_fragment(iph))

			*proto = iph->protocol;

	} else if (skb->protocol == htons(ETH_P_IPV6)) {

		if (unlikely(!pskb_may_pull(skb, *noff + sizeof(*iph6))))

			*ip_proto = iph->protocol;

	} else if (l2_proto == htons(ETH_P_IPV6)) {

		data = bond_pull_data(skb, data, hlen, *nhoff + sizeof(*iph6));

		if (!data)

			return false;

		iph6 = (const struct ipv6hdr *)(skb->data + *noff);



		iph6 = (const struct ipv6hdr *)(data + *nhoff);

		iph_to_flow_copy_v6addrs(fk, iph6);

		*noff += sizeof(*iph6);

		*proto = iph6->nexthdr;

		*nhoff += sizeof(*iph6);

		*ip_proto = iph6->nexthdr;

	} else {

		return false;

	}



	if (l34 && *proto >= 0)

		fk->ports.ports = skb_flow_get_ports(skb, *noff, *proto);

	if (l34 && *ip_proto >= 0)

		fk->ports.ports = __skb_flow_get_ports(skb, *nhoff, *ip_proto, data, hlen);



	return true;

}



static u32 bond_vlan_srcmac_hash(struct sk_buff *skb)

static u32 bond_vlan_srcmac_hash(struct sk_buff *skb, const void *data, int mhoff, int hlen)

{

	struct ethhdr *mac_hdr = (struct ethhdr *)skb_mac_header(skb);

	struct ethhdr *mac_hdr;

	u32 srcmac_vendor = 0, srcmac_dev = 0;

	u16 vlan;

	int i;



	data = bond_pull_data(skb, data, hlen, mhoff + sizeof(struct ethhdr));

	if (!data)

		return 0;

	mac_hdr = (struct ethhdr *)(data + mhoff);



	for (i = 0; i < 3; i++)

		srcmac_vendor = (srcmac_vendor << 8) | mac_hdr->h_source[i];
@@ -3678,26 +3703,25 @@ static u32 bond_vlan_srcmac_hash(struct sk_buff *skb) 
}



/* Extract the appropriate headers based on bond's xmit policy */

static bool bond_flow_dissect(struct bonding *bond, struct sk_buff *skb,

			      struct flow_keys *fk)

static bool bond_flow_dissect(struct bonding *bond, struct sk_buff *skb, const void *data,

			      __be16 l2_proto, int nhoff, int hlen, struct flow_keys *fk)

{

	bool l34 = bond->params.xmit_policy == BOND_XMIT_POLICY_LAYER34;

	int noff, proto = -1;

	int ip_proto = -1;



	switch (bond->params.xmit_policy) {

	case BOND_XMIT_POLICY_ENCAP23:

	case BOND_XMIT_POLICY_ENCAP34:

		memset(fk, 0, sizeof(*fk));

		return __skb_flow_dissect(NULL, skb, &flow_keys_bonding,

					  fk, NULL, 0, 0, 0, 0);

					  fk, data, l2_proto, nhoff, hlen, 0);

	default:

		break;

	}



	fk->ports.ports = 0;

	memset(&fk->icmp, 0, sizeof(fk->icmp));

	noff = skb_network_offset(skb);

	if (!bond_flow_ip(skb, fk, &noff, &proto, l34))

	if (!bond_flow_ip(skb, fk, data, hlen, l2_proto, &nhoff, &ip_proto, l34))

		return false;



	/* ICMP error packets contains at least 8 bytes of the header
@@ -3705,22 +3729,20 @@ static bool bond_flow_dissect(struct bonding *bond, struct sk_buff *skb, 
	 * to correlate ICMP error packets within the same flow which

	 * generated the error.

	 */

	if (proto == IPPROTO_ICMP || proto == IPPROTO_ICMPV6) {

		skb_flow_get_icmp_tci(skb, &fk->icmp, skb->data,

				      skb_transport_offset(skb),

				      skb_headlen(skb));

		if (proto == IPPROTO_ICMP) {

	if (ip_proto == IPPROTO_ICMP || ip_proto == IPPROTO_ICMPV6) {

		skb_flow_get_icmp_tci(skb, &fk->icmp, data, nhoff, hlen);

		if (ip_proto == IPPROTO_ICMP) {

			if (!icmp_is_err(fk->icmp.type))

				return true;



			noff += sizeof(struct icmphdr);

		} else if (proto == IPPROTO_ICMPV6) {

			nhoff += sizeof(struct icmphdr);

		} else if (ip_proto == IPPROTO_ICMPV6) {

			if (!icmpv6_is_err(fk->icmp.type))

				return true;



			noff += sizeof(struct icmp6hdr);

			nhoff += sizeof(struct icmp6hdr);

		}

		return bond_flow_ip(skb, fk, &noff, &proto, l34);

		return bond_flow_ip(skb, fk, data, hlen, l2_proto, &nhoff, &ip_proto, l34);

	}



	return true;
@@ -3736,33 +3758,26 @@ static u32 bond_ip_hash(u32 hash, struct flow_keys *flow) 
	return hash >> 1;

}



/**

 * bond_xmit_hash - generate a hash value based on the xmit policy

 * @bond: bonding device

 * @skb: buffer to use for headers

 *

 * This function will extract the necessary headers from the skb buffer and use

 * them to generate a hash based on the xmit_policy set in the bonding device

/* Generate hash based on xmit policy. If @skb is given it is used to linearize

 * the data as required, but this function can be used without it if the data is

 * known to be linear (e.g. with xdp_buff).

 */

u32 bond_xmit_hash(struct bonding *bond, struct sk_buff *skb)

static u32 __bond_xmit_hash(struct bonding *bond, struct sk_buff *skb, const void *data,

			    __be16 l2_proto, int mhoff, int nhoff, int hlen)

{

	struct flow_keys flow;

	u32 hash;



	if (bond->params.xmit_policy == BOND_XMIT_POLICY_ENCAP34 &&

	    skb->l4_hash)

		return skb->hash;



	if (bond->params.xmit_policy == BOND_XMIT_POLICY_VLAN_SRCMAC)

		return bond_vlan_srcmac_hash(skb);

		return bond_vlan_srcmac_hash(skb, data, mhoff, hlen);



	if (bond->params.xmit_policy == BOND_XMIT_POLICY_LAYER2 ||

	    !bond_flow_dissect(bond, skb, &flow))

		return bond_eth_hash(skb);

	    !bond_flow_dissect(bond, skb, data, l2_proto, nhoff, hlen, &flow))

		return bond_eth_hash(skb, data, mhoff, hlen);



	if (bond->params.xmit_policy == BOND_XMIT_POLICY_LAYER23 ||

	    bond->params.xmit_policy == BOND_XMIT_POLICY_ENCAP23) {

		hash = bond_eth_hash(skb);

		hash = bond_eth_hash(skb, data, mhoff, hlen);

	} else {

		if (flow.icmp.id)

			memcpy(&hash, &flow.icmp, sizeof(hash));
@@ -3773,6 +3788,25 @@ u32 bond_xmit_hash(struct bonding *bond, struct sk_buff *skb) 
	return bond_ip_hash(hash, &flow);

}



/**

 * bond_xmit_hash - generate a hash value based on the xmit policy

 * @bond: bonding device

 * @skb: buffer to use for headers

 *

 * This function will extract the necessary headers from the skb buffer and use

 * them to generate a hash based on the xmit_policy set in the bonding device

 */

u32 bond_xmit_hash(struct bonding *bond, struct sk_buff *skb)

{

	if (bond->params.xmit_policy == BOND_XMIT_POLICY_ENCAP34 &&

	    skb->l4_hash)

		return skb->hash;



	return __bond_xmit_hash(bond, skb, skb->head, skb->protocol,

				skb->mac_header, skb->network_header,

				skb_headlen(skb));

}



/*-------------------------- Device entry points ----------------------------*/



void bond_work_init_all(struct bonding *bond)
@@ -4434,8 +4468,7 @@ static netdev_tx_t bond_xmit_roundrobin(struct sk_buff *skb, 
	return bond_tx_drop(bond_dev, skb);

}



static struct slave *bond_xmit_activebackup_slave_get(struct bonding *bond,

						      struct sk_buff *skb)

static struct slave *bond_xmit_activebackup_slave_get(struct bonding *bond)

{

	return rcu_dereference(bond->curr_active_slave);

}
@@ -4449,7 +4482,7 @@ static netdev_tx_t bond_xmit_activebackup(struct sk_buff *skb, 
	struct bonding *bond = netdev_priv(bond_dev);

	struct slave *slave;



	slave = bond_xmit_activebackup_slave_get(bond, skb);

	slave = bond_xmit_activebackup_slave_get(bond);

	if (slave)

		return bond_dev_queue_xmit(bond, skb, slave->dev);
@@ -4747,7 +4780,7 @@ static struct net_device *bond_xmit_get_slave(struct net_device *master_dev, 
		slave = bond_xmit_roundrobin_slave_get(bond, skb);

		break;

	case BOND_MODE_ACTIVEBACKUP:

		slave = bond_xmit_activebackup_slave_get(bond, skb);

		slave = bond_xmit_activebackup_slave_get(bond);

		break;

	case BOND_MODE_8023AD:

	case BOND_MODE_XOR: