1 // Copyright (c) PLUMgrid, Inc. 2 // Licensed under the Apache License, Version 2.0 (the "License") 3 #include <bcc/proto.h> 4 5 #define _memcpy __builtin_memcpy 6 7 // meta data passed between bpf programs 8 typedef struct bpf_metadata { 9 u32 prog_id; 10 u32 rx_port_id; 11 } bpf_metadata_t; 12 13 typedef struct bpf_dest { 14 u32 prog_id; 15 u32 port_id; 16 } bpf_dest_t; 17 18 // use u64 to represent eth_addr. 19 // maintain the structure though to indicate the semantics 20 typedef struct eth_addr { 21 u64 addr; 22 } eth_addr_t; 23 24 // Program table definitions for tail calls 25 BPF_PROG_ARRAY(jump, 16); 26 27 // physical endpoint manager (pem) tables which connects to boeht bridge 1 and bridge 2 28 // <port_id, bpf_dest> 29 BPF_ARRAY(pem_dest, bpf_dest_t, 256); 30 // <port_id, ifindex> 31 BPF_ARRAY(pem_port, u32, 256); 32 // <ifindex, port_id> 33 BPF_HASH(pem_ifindex, u32, u32, 256); 34 // <0, tx2vm_pkts> 35 BPF_ARRAY(pem_stats, u32, 1); 36 37 // bridge 1 (br1) tables 38 // <port_id, bpf_dest> 39 BPF_ARRAY(br1_dest, bpf_dest_t, 256); 40 // <eth_addr, port_id> 41 BPF_HASH(br1_mac, eth_addr_t, u32, 256); 42 // <0, rtr_ifindex> 43 BPF_ARRAY(br1_rtr, u32, 1); 44 // <mac, ifindex> 45 BPF_HASH(br1_mac_ifindex, eth_addr_t, u32, 1); 46 47 // bridge 2 (br2) tables 48 // <port_id, bpf_dest> 49 BPF_ARRAY(br2_dest, bpf_dest_t, 256); 50 // <eth_addr, port_id> 51 BPF_HASH(br2_mac, eth_addr_t, u32, 256); 52 // <0, rtr_ifindex> 53 BPF_ARRAY(br2_rtr, u32, 1); 54 // <mac, ifindex> 55 BPF_HASH(br2_mac_ifindex, eth_addr_t, u32, 1); 56 57 int pem(struct __sk_buff *skb) { 58 bpf_metadata_t meta = {}; 59 u32 ifindex; 60 u32 *tx_port_id_p; 61 u32 tx_port_id; 62 u32 rx_port; 63 u32 *ifindex_p; 64 bpf_dest_t *dest_p; 65 66 // pem does not look at packet data 67 if (skb->tc_index == 0) { 68 skb->tc_index = 1; 69 skb->cb[0] = skb->cb[1] = 0; 70 meta.prog_id = meta.rx_port_id = 0; 71 } else { 72 meta.prog_id = skb->cb[0]; 73 asm volatile("" ::: "memory"); 74 meta.rx_port_id = skb->cb[1]; 75 } 76 if (!meta.prog_id) { 77 /* from external */ 78 ifindex = skb->ingress_ifindex; 79 tx_port_id_p = pem_ifindex.lookup(&ifindex); 80 if (tx_port_id_p) { 81 tx_port_id = *tx_port_id_p; 82 dest_p = pem_dest.lookup(&tx_port_id); 83 if (dest_p) { 84 skb->cb[0] = dest_p->prog_id; 85 skb->cb[1] = dest_p->port_id; 86 jump.call(skb, dest_p->prog_id); 87 } 88 } 89 } else { 90 /* from internal */ 91 rx_port = meta.rx_port_id; 92 ifindex_p = pem_port.lookup(&rx_port); 93 if (ifindex_p) { 94 #if 1 95 /* accumulate stats, may hurt performance slightly */ 96 u32 index = 0; 97 u32 *value = pem_stats.lookup(&index); 98 if (value) 99 lock_xadd(value, 1); 100 #endif 101 bpf_clone_redirect(skb, *ifindex_p, 0); 102 } 103 } 104 105 return 1; 106 } 107 108 static int br_common(struct __sk_buff *skb, int which_br) { 109 u8 *cursor = 0; 110 u16 proto; 111 u16 arpop; 112 eth_addr_t dmac; 113 u8 *mac_p; 114 u32 dip; 115 u32 *tx_port_id_p; 116 u32 tx_port_id; 117 bpf_dest_t *dest_p; 118 u32 index, *rtrif_p; 119 120 struct ethernet_t *ethernet = cursor_advance(cursor, sizeof(*ethernet)); 121 /* handle ethernet packet header */ 122 { 123 dmac.addr = ethernet->dst; 124 /* skb->tc_index may be preserved across router namespace if router simply rewrite packet 125 * and send it back. 126 */ 127 if (skb->tc_index == 1) { 128 /* packet from pem, send to the router, set tc_index to 2 */ 129 skb->tc_index = 2; 130 if (dmac.addr == 0xffffffffffffULL) { 131 index = 0; 132 if (which_br == 1) 133 rtrif_p = br1_rtr.lookup(&index); 134 else 135 rtrif_p = br2_rtr.lookup(&index); 136 if (rtrif_p) 137 bpf_clone_redirect(skb, *rtrif_p, 0); 138 } else { 139 /* the dmac address should match the router's */ 140 if (which_br == 1) 141 rtrif_p = br1_mac_ifindex.lookup(&dmac); 142 else 143 rtrif_p = br2_mac_ifindex.lookup(&dmac); 144 if (rtrif_p) 145 bpf_clone_redirect(skb, *rtrif_p, 0); 146 } 147 return 1; 148 } 149 150 /* set the tc_index to 1 so pem knows it is from internal */ 151 skb->tc_index = 1; 152 switch (ethernet->type) { 153 case ETH_P_IP: goto ip; 154 case ETH_P_ARP: goto arp; 155 case ETH_P_8021Q: goto dot1q; 156 default: goto EOP; 157 } 158 } 159 160 dot1q: { 161 struct dot1q_t *dot1q = cursor_advance(cursor, sizeof(*dot1q)); 162 switch(dot1q->type) { 163 case ETH_P_IP: goto ip; 164 case ETH_P_ARP: goto arp; 165 default: goto EOP; 166 } 167 } 168 169 arp: { 170 struct arp_t *arp = cursor_advance(cursor, sizeof(*arp)); 171 /* mac learning */ 172 arpop = arp->oper; 173 if (arpop == 2) { 174 index = 0; 175 if (which_br == 1) 176 rtrif_p = br1_rtr.lookup(&index); 177 else 178 rtrif_p = br2_rtr.lookup(&index); 179 if (rtrif_p) { 180 __u32 ifindex = *rtrif_p; 181 eth_addr_t smac; 182 183 smac.addr = ethernet->src; 184 if (which_br == 1) 185 br1_mac_ifindex.update(&smac, &ifindex); 186 else 187 br2_mac_ifindex.update(&smac, &ifindex); 188 } 189 } 190 goto xmit; 191 } 192 193 ip: { 194 struct ip_t *ip = cursor_advance(cursor, sizeof(*ip)); 195 goto xmit; 196 } 197 198 xmit: 199 if (which_br == 1) 200 tx_port_id_p = br1_mac.lookup(&dmac); 201 else 202 tx_port_id_p = br2_mac.lookup(&dmac); 203 if (tx_port_id_p) { 204 tx_port_id = *tx_port_id_p; 205 if (which_br == 1) 206 dest_p = br1_dest.lookup(&tx_port_id); 207 else 208 dest_p = br2_dest.lookup(&tx_port_id); 209 if (dest_p) { 210 skb->cb[0] = dest_p->prog_id; 211 skb->cb[1] = dest_p->port_id; 212 jump.call(skb, dest_p->prog_id); 213 } 214 } 215 216 EOP: 217 return 1; 218 } 219 220 int br1(struct __sk_buff *skb) { 221 return br_common(skb, 1); 222 } 223 224 int br2(struct __sk_buff *skb) { 225 return br_common(skb, 2); 226 } 227
