| #include <linux/skbuff.h> |
| #include <linux/export.h> |
| #include <linux/ip.h> |
| #include <linux/ipv6.h> |
| #include <linux/if_vlan.h> |
| #include <net/ip.h> |
| #include <net/ipv6.h> |
| #include <linux/igmp.h> |
| #include <linux/icmp.h> |
| #include <linux/sctp.h> |
| #include <linux/dccp.h> |
| #include <linux/if_tunnel.h> |
| #include <linux/if_pppox.h> |
| #include <linux/ppp_defs.h> |
| #include <net/flow_keys.h> |
| |
| /* copy saddr & daddr, possibly using 64bit load/store |
| * Equivalent to : flow->src = iph->saddr; |
| * flow->dst = iph->daddr; |
| */ |
| static void iph_to_flow_copy_addrs(struct flow_keys *flow, const struct iphdr *iph) |
| { |
| BUILD_BUG_ON(offsetof(typeof(*flow), dst) != |
| offsetof(typeof(*flow), src) + sizeof(flow->src)); |
| memcpy(&flow->src, &iph->saddr, sizeof(flow->src) + sizeof(flow->dst)); |
| } |
| |
| /** |
| * skb_flow_get_ports - extract the upper layer ports and return them |
| * @skb: buffer to extract the ports from |
| * @thoff: transport header offset |
| * @ip_proto: protocol for which to get port offset |
| * |
| * The function will try to retrieve the ports at offset thoff + poff where poff |
| * is the protocol port offset returned from proto_ports_offset |
| */ |
| __be32 skb_flow_get_ports(const struct sk_buff *skb, int thoff, u8 ip_proto) |
| { |
| int poff = proto_ports_offset(ip_proto); |
| |
| if (poff >= 0) { |
| __be32 *ports, _ports; |
| |
| ports = skb_header_pointer(skb, thoff + poff, |
| sizeof(_ports), &_ports); |
| if (ports) |
| return *ports; |
| } |
| |
| return 0; |
| } |
| EXPORT_SYMBOL(skb_flow_get_ports); |
| |
| bool skb_flow_dissect(const struct sk_buff *skb, struct flow_keys *flow) |
| { |
| int nhoff = skb_network_offset(skb); |
| u8 ip_proto; |
| __be16 proto = skb->protocol; |
| |
| memset(flow, 0, sizeof(*flow)); |
| |
| again: |
| switch (proto) { |
| case htons(ETH_P_IP): { |
| const struct iphdr *iph; |
| struct iphdr _iph; |
| ip: |
| iph = skb_header_pointer(skb, nhoff, sizeof(_iph), &_iph); |
| if (!iph || iph->ihl < 5) |
| return false; |
| nhoff += iph->ihl * 4; |
| |
| ip_proto = iph->protocol; |
| if (ip_is_fragment(iph)) |
| ip_proto = 0; |
| |
| iph_to_flow_copy_addrs(flow, iph); |
| break; |
| } |
| case htons(ETH_P_IPV6): { |
| const struct ipv6hdr *iph; |
| struct ipv6hdr _iph; |
| ipv6: |
| iph = skb_header_pointer(skb, nhoff, sizeof(_iph), &_iph); |
| if (!iph) |
| return false; |
| |
| ip_proto = iph->nexthdr; |
| flow->src = (__force __be32)ipv6_addr_hash(&iph->saddr); |
| flow->dst = (__force __be32)ipv6_addr_hash(&iph->daddr); |
| nhoff += sizeof(struct ipv6hdr); |
| break; |
| } |
| case htons(ETH_P_8021AD): |
| case htons(ETH_P_8021Q): { |
| const struct vlan_hdr *vlan; |
| struct vlan_hdr _vlan; |
| |
| vlan = skb_header_pointer(skb, nhoff, sizeof(_vlan), &_vlan); |
| if (!vlan) |
| return false; |
| |
| proto = vlan->h_vlan_encapsulated_proto; |
| nhoff += sizeof(*vlan); |
| goto again; |
| } |
| case htons(ETH_P_PPP_SES): { |
| struct { |
| struct pppoe_hdr hdr; |
| __be16 proto; |
| } *hdr, _hdr; |
| hdr = skb_header_pointer(skb, nhoff, sizeof(_hdr), &_hdr); |
| if (!hdr) |
| return false; |
| proto = hdr->proto; |
| nhoff += PPPOE_SES_HLEN; |
| switch (proto) { |
| case htons(PPP_IP): |
| goto ip; |
| case htons(PPP_IPV6): |
| goto ipv6; |
| default: |
| return false; |
| } |
| } |
| default: |
| return false; |
| } |
| |
| switch (ip_proto) { |
| case IPPROTO_GRE: { |
| struct gre_hdr { |
| __be16 flags; |
| __be16 proto; |
| } *hdr, _hdr; |
| |
| hdr = skb_header_pointer(skb, nhoff, sizeof(_hdr), &_hdr); |
| if (!hdr) |
| return false; |
| /* |
| * Only look inside GRE if version zero and no |
| * routing |
| */ |
| if (!(hdr->flags & (GRE_VERSION|GRE_ROUTING))) { |
| proto = hdr->proto; |
| nhoff += 4; |
| if (hdr->flags & GRE_CSUM) |
| nhoff += 4; |
| if (hdr->flags & GRE_KEY) |
| nhoff += 4; |
| if (hdr->flags & GRE_SEQ) |
| nhoff += 4; |
| if (proto == htons(ETH_P_TEB)) { |
| const struct ethhdr *eth; |
| struct ethhdr _eth; |
| |
| eth = skb_header_pointer(skb, nhoff, |
| sizeof(_eth), &_eth); |
| if (!eth) |
| return false; |
| proto = eth->h_proto; |
| nhoff += sizeof(*eth); |
| } |
| goto again; |
| } |
| break; |
| } |
| case IPPROTO_IPIP: |
| proto = htons(ETH_P_IP); |
| goto ip; |
| case IPPROTO_IPV6: |
| proto = htons(ETH_P_IPV6); |
| goto ipv6; |
| default: |
| break; |
| } |
| |
| flow->n_proto = proto; |
| flow->ip_proto = ip_proto; |
| flow->ports = skb_flow_get_ports(skb, nhoff, ip_proto); |
| flow->thoff = (u16) nhoff; |
| |
| return true; |
| } |
| EXPORT_SYMBOL(skb_flow_dissect); |
| |
| static u32 hashrnd __read_mostly; |
| static __always_inline void __flow_hash_secret_init(void) |
| { |
| net_get_random_once(&hashrnd, sizeof(hashrnd)); |
| } |
| |
| static __always_inline u32 __flow_hash_3words(u32 a, u32 b, u32 c) |
| { |
| __flow_hash_secret_init(); |
| return jhash_3words(a, b, c, hashrnd); |
| } |
| |
| static inline u32 __flow_hash_from_keys(struct flow_keys *keys) |
| { |
| u32 hash; |
| |
| /* get a consistent hash (same value on both flow directions) */ |
| if (((__force u32)keys->dst < (__force u32)keys->src) || |
| (((__force u32)keys->dst == (__force u32)keys->src) && |
| ((__force u16)keys->port16[1] < (__force u16)keys->port16[0]))) { |
| swap(keys->dst, keys->src); |
| swap(keys->port16[0], keys->port16[1]); |
| } |
| |
| hash = __flow_hash_3words((__force u32)keys->dst, |
| (__force u32)keys->src, |
| (__force u32)keys->ports); |
| if (!hash) |
| hash = 1; |
| |
| return hash; |
| } |
| |
| u32 flow_hash_from_keys(struct flow_keys *keys) |
| { |
| return __flow_hash_from_keys(keys); |
| } |
| EXPORT_SYMBOL(flow_hash_from_keys); |
| |
| /* |
| * __skb_get_hash: calculate a flow hash based on src/dst addresses |
| * and src/dst port numbers. Sets hash in skb to non-zero hash value |
| * on success, zero indicates no valid hash. Also, sets l4_hash in skb |
| * if hash is a canonical 4-tuple hash over transport ports. |
| */ |
| void __skb_get_hash(struct sk_buff *skb) |
| { |
| struct flow_keys keys; |
| |
| if (!skb_flow_dissect(skb, &keys)) |
| return; |
| |
| if (keys.ports) |
| skb->l4_hash = 1; |
| |
| skb->hash = __flow_hash_from_keys(&keys); |
| } |
| EXPORT_SYMBOL(__skb_get_hash); |
| |
| /* |
| * Returns a Tx hash based on the given packet descriptor a Tx queues' number |
| * to be used as a distribution range. |
| */ |
| u16 __skb_tx_hash(const struct net_device *dev, struct sk_buff *skb, |
| unsigned int num_tx_queues) |
| { |
| u32 hash; |
| u16 qoffset = 0; |
| u16 qcount = num_tx_queues; |
| |
| if (skb_rx_queue_recorded(skb)) { |
| hash = skb_get_rx_queue(skb); |
| while (unlikely(hash >= num_tx_queues)) |
| hash -= num_tx_queues; |
| return hash; |
| } |
| |
| if (dev->num_tc) { |
| u8 tc = netdev_get_prio_tc_map(dev, skb->priority); |
| qoffset = dev->tc_to_txq[tc].offset; |
| qcount = dev->tc_to_txq[tc].count; |
| } |
| |
| return (u16) (((u64)skb_get_hash(skb) * qcount) >> 32) + qoffset; |
| } |
| EXPORT_SYMBOL(__skb_tx_hash); |
| |
| /* __skb_get_poff() returns the offset to the payload as far as it could |
| * be dissected. The main user is currently BPF, so that we can dynamically |
| * truncate packets without needing to push actual payload to the user |
| * space and can analyze headers only, instead. |
| */ |
| u32 __skb_get_poff(const struct sk_buff *skb) |
| { |
| struct flow_keys keys; |
| u32 poff = 0; |
| |
| if (!skb_flow_dissect(skb, &keys)) |
| return 0; |
| |
| poff += keys.thoff; |
| switch (keys.ip_proto) { |
| case IPPROTO_TCP: { |
| const struct tcphdr *tcph; |
| struct tcphdr _tcph; |
| |
| tcph = skb_header_pointer(skb, poff, sizeof(_tcph), &_tcph); |
| if (!tcph) |
| return poff; |
| |
| poff += max_t(u32, sizeof(struct tcphdr), tcph->doff * 4); |
| break; |
| } |
| case IPPROTO_UDP: |
| case IPPROTO_UDPLITE: |
| poff += sizeof(struct udphdr); |
| break; |
| /* For the rest, we do not really care about header |
| * extensions at this point for now. |
| */ |
| case IPPROTO_ICMP: |
| poff += sizeof(struct icmphdr); |
| break; |
| case IPPROTO_ICMPV6: |
| poff += sizeof(struct icmp6hdr); |
| break; |
| case IPPROTO_IGMP: |
| poff += sizeof(struct igmphdr); |
| break; |
| case IPPROTO_DCCP: |
| poff += sizeof(struct dccp_hdr); |
| break; |
| case IPPROTO_SCTP: |
| poff += sizeof(struct sctphdr); |
| break; |
| } |
| |
| return poff; |
| } |
| |
| static inline int get_xps_queue(struct net_device *dev, struct sk_buff *skb) |
| { |
| #ifdef CONFIG_XPS |
| struct xps_dev_maps *dev_maps; |
| struct xps_map *map; |
| int queue_index = -1; |
| |
| rcu_read_lock(); |
| dev_maps = rcu_dereference(dev->xps_maps); |
| if (dev_maps) { |
| map = rcu_dereference( |
| dev_maps->cpu_map[raw_smp_processor_id()]); |
| if (map) { |
| if (map->len == 1) |
| queue_index = map->queues[0]; |
| else |
| queue_index = map->queues[ |
| ((u64)skb_get_hash(skb) * map->len) >> 32]; |
| |
| if (unlikely(queue_index >= dev->real_num_tx_queues)) |
| queue_index = -1; |
| } |
| } |
| rcu_read_unlock(); |
| |
| return queue_index; |
| #else |
| return -1; |
| #endif |
| } |
| |
| static u16 __netdev_pick_tx(struct net_device *dev, struct sk_buff *skb) |
| { |
| struct sock *sk = skb->sk; |
| int queue_index = sk_tx_queue_get(sk); |
| |
| if (queue_index < 0 || skb->ooo_okay || |
| queue_index >= dev->real_num_tx_queues) { |
| int new_index = get_xps_queue(dev, skb); |
| if (new_index < 0) |
| new_index = skb_tx_hash(dev, skb); |
| |
| if (queue_index != new_index && sk && |
| rcu_access_pointer(sk->sk_dst_cache)) |
| sk_tx_queue_set(sk, new_index); |
| |
| queue_index = new_index; |
| } |
| |
| return queue_index; |
| } |
| |
| struct netdev_queue *netdev_pick_tx(struct net_device *dev, |
| struct sk_buff *skb, |
| void *accel_priv) |
| { |
| int queue_index = 0; |
| |
| if (dev->real_num_tx_queues != 1) { |
| const struct net_device_ops *ops = dev->netdev_ops; |
| if (ops->ndo_select_queue) |
| queue_index = ops->ndo_select_queue(dev, skb, accel_priv, |
| __netdev_pick_tx); |
| else |
| queue_index = __netdev_pick_tx(dev, skb); |
| |
| if (!accel_priv) |
| queue_index = netdev_cap_txqueue(dev, queue_index); |
| } |
| |
| skb_set_queue_mapping(skb, queue_index); |
| return netdev_get_tx_queue(dev, queue_index); |
| } |