| // Copyright (c) PLUMgrid, Inc. |
| // Licensed under the Apache License, Version 2.0 (the "License") |
| |
| #include <bcc/proto.h> |
| |
| // hash |
| struct FwdKey { |
| u32 dip:32; |
| }; |
| struct FwdLeaf { |
| u32 fwd_idx:32; |
| }; |
| BPF_TABLE("hash", struct FwdKey, struct FwdLeaf, fwd_map, 1); |
| |
| // array |
| struct ConfigKey { |
| u32 index; |
| }; |
| struct ConfigLeaf { |
| u32 bpfdev_ip; |
| u32 slave_ip; |
| }; |
| BPF_TABLE("array", struct ConfigKey, struct ConfigLeaf, config_map, 1); |
| |
| // hash |
| struct MacaddrKey { |
| u32 ip; |
| }; |
| struct MacaddrLeaf { |
| u64 mac; |
| }; |
| BPF_TABLE("hash", struct MacaddrKey, struct MacaddrLeaf, macaddr_map, 11); |
| |
| // hash |
| struct SlaveKey { |
| u32 slave_ip; |
| }; |
| struct SlaveLeaf { |
| u32 slave_ifindex; |
| }; |
| BPF_TABLE("hash", struct SlaveKey, struct SlaveLeaf, slave_map, 10); |
| |
| int handle_packet(struct __sk_buff *skb) { |
| int ret = 0; |
| u8 *cursor = 0; |
| |
| if (skb->pkt_type == 0) { |
| // tx |
| // make sure configured |
| u32 slave_ip; |
| |
| struct ConfigKey cfg_key = {.index = 0}; |
| struct ConfigLeaf *cfg_leaf = config_map.lookup(&cfg_key); |
| if (cfg_leaf) { |
| slave_ip = cfg_leaf->slave_ip; |
| } else { |
| return 0xffffffff; |
| } |
| |
| // make sure slave configured |
| // tx, default to the single slave |
| struct SlaveKey slave_key = {.slave_ip = slave_ip}; |
| struct SlaveLeaf *slave_leaf = slave_map.lookup(&slave_key); |
| if (slave_leaf) { |
| ret = slave_leaf->slave_ifindex; |
| } else { |
| return 0xffffffff; |
| } |
| } else { |
| // rx, default to stack |
| ret = 0; |
| } |
| |
| struct ethernet_t *ethernet = cursor_advance(cursor, sizeof(*ethernet)); |
| switch (ethernet->type) { |
| case ETH_P_IP: goto ip; |
| case ETH_P_ARP: goto arp; |
| case ETH_P_8021Q: goto dot1q; |
| default: goto EOP; |
| } |
| |
| dot1q: { |
| struct dot1q_t *dot1q = cursor_advance(cursor, sizeof(*dot1q)); |
| switch (dot1q->type) { |
| case ETH_P_IP: goto ip; |
| case ETH_P_ARP: goto arp; |
| default: goto EOP; |
| } |
| } |
| |
| arp: { |
| struct arp_t *arp = cursor_advance(cursor, sizeof(*arp)); |
| if (skb->pkt_type) { |
| if (arp->oper == 1) { |
| struct MacaddrKey mac_key = {.ip=arp->spa}; |
| struct MacaddrLeaf mac_leaf = {.mac=arp->sha}; |
| macaddr_map.update(&mac_key, &mac_leaf); |
| } |
| } |
| goto EOP; |
| } |
| |
| struct ip_t *ip = cursor_advance(cursor, sizeof(*ip)); |
| ip: { |
| switch (ip->nextp) { |
| case 6: goto tcp; |
| case 17: goto udp; |
| default: goto EOP; |
| } |
| } |
| tcp: { |
| struct tcp_t *tcp = cursor_advance(cursor, sizeof(*tcp)); |
| goto EOP; |
| } |
| udp: { |
| struct udp_t *udp = cursor_advance(cursor, sizeof(*udp)); |
| if (udp->dport != 5000) { |
| goto EOP; |
| } |
| if (skb->pkt_type) { |
| // lookup and then forward |
| struct FwdKey fwd_key = {.dip=ip->dst}; |
| struct FwdLeaf *fwd_val = fwd_map.lookup(&fwd_key); |
| if (fwd_val) { |
| return fwd_val->fwd_idx; |
| } |
| } else { |
| // rewrite the packet and send to a pre-configured index if needed |
| u32 new_ip; |
| u32 old_ip; |
| u64 src_mac; |
| u64 dst_mac; |
| |
| struct ConfigKey cfg_key = {.index = 0}; |
| struct ConfigLeaf *cfg_leaf = config_map.lookup(&cfg_key); |
| if (cfg_leaf) { |
| struct MacaddrKey mac_key = {.ip = cfg_leaf->bpfdev_ip}; |
| struct MacaddrLeaf *mac_leaf; |
| |
| mac_key.ip = cfg_leaf->bpfdev_ip; |
| mac_leaf = macaddr_map.lookup(&mac_key); |
| if (mac_leaf) { |
| src_mac = mac_leaf->mac; |
| } else { |
| goto EOP; |
| } |
| |
| mac_key.ip = cfg_leaf->slave_ip; |
| mac_leaf = macaddr_map.lookup(&mac_key); |
| if (mac_leaf) { |
| dst_mac = mac_leaf->mac; |
| } else { |
| goto EOP; |
| } |
| |
| // rewrite ethernet header |
| ethernet->dst = dst_mac; |
| ethernet->src = src_mac; |
| |
| // ip & udp checksum |
| incr_cksum_l4(&udp->crc, ip->src, cfg_leaf->bpfdev_ip, 1); |
| incr_cksum_l4(&udp->crc, ip->dst, cfg_leaf->slave_ip, 1); |
| |
| // rewrite ip src/dst fields |
| ip->src = cfg_leaf->bpfdev_ip; |
| ip->dst = cfg_leaf->slave_ip; |
| } |
| } |
| goto EOP; |
| } |
| |
| EOP: |
| return ret; |
| } |