int connect_v4_prog(struct bpf_sock_addr *ctx)
{
struct sockaddr_in sa;
/* Rewrite destination. */
ctx->user_ip4 = bpf_htonl(DST_REWRITE_IP4);
ctx->user_port = bpf_htons(DST_REWRITE_PORT4);
if (ctx->type == SOCK_DGRAM || ctx->type == SOCK_STREAM) {
///* Rewrite source. */
memset(&sa, 0, sizeof(sa));
sa.sin_family = AF_INET;
sa.sin_port = bpf_htons(0);
sa.sin_addr.s_addr = bpf_htonl(SRC_REWRITE_IP4);
if (bpf_bind(ctx, (struct sockaddr *)&sa, sizeof(sa)) != 0)
return 0;
}
return 1;
}
static int handle_rx(void *skb, struct metadata *md) {
struct __sk_buff *skb2 = (struct __sk_buff *)skb;
void *data = (void *)(long)skb2->data;
void *data_end = (void *)(long)skb2->data_end;
struct eth_hdr *eth = data;
if (data + sizeof(*eth) > data_end)
return RX_DROP;
u32 in_ifc = md->in_ifc;
#ifdef BPF_TRACE
bpf_trace_printk("[switch-%d]: in_ifc=%d\n", md->module_id, in_ifc);
#endif
// port security on source mac
#ifdef MAC_SECURITY_INGRESS
__be64 *mac_lookup = securitymac.lookup(&in_ifc);
if (mac_lookup)
if (eth->src != *mac_lookup) {
#ifdef BPF_TRACE
bpf_trace_printk("[switch-%d]: mac INGRESS %lx mismatch %lx -> DROP\n",
md->module_id, PRINT_MAC(eth->src), PRINT_MAC(*mac_lookup));
#endif
return RX_DROP;
}
#endif
// port security on source ip
#ifdef IP_SECURITY_INGRESS
if (eth->proto == bpf_htons(ETH_P_IP)) {
__be32 *ip_lookup = securityip.lookup(&in_ifc);
if (ip_lookup) {
struct ip_t *ip = data + sizeof(*eth);
if (data + sizeof(*eth) + sizeof(*ip) > data_end)
return RX_DROP;
if (ip->src != *ip_lookup) {
#ifdef BPF_TRACE
bpf_trace_printk("[switch-%d]: IP INGRESS %x mismatch %x -> DROP\n",
md->module_id, bpf_htonl(ip->src), bpf_htonl(*ip_lookup));
#endif
return RX_DROP;
}
}
}
#endif
#ifdef BPF_TRACE
bpf_trace_printk("[switch-%d]: mac src:%lx dst:%lx\n",
md->module_id, PRINT_MAC(eth->src), PRINT_MAC(eth->dst));
#endif
//LEARNING PHASE: mapping in_ifc with src_interface
__be64 src_key = eth->src;
//lookup in fwdtable. if no key present initialize with interface
u32 *interface_lookup = fwdtable.lookup_or_init(&src_key, &in_ifc);
//if the same mac has changed interface, update it
if (*interface_lookup != in_ifc)
*interface_lookup = in_ifc;
//FORWARDING PHASE: select interface(s) to send the packet
__be64 dst_mac = eth->dst;
//lookup in forwarding table fwdtable
u32 *dst_interface = fwdtable.lookup(&dst_mac);
if (dst_interface) {
//HIT in forwarding table
//redirect packet to dst_interface
#ifdef MAC_SECURITY_EGRESS
u32 out_iface = *dst_interface;
__be64 *mac_lookup = securitymac.lookup(&out_iface);
if (mac_lookup)
if (eth->dst != *mac_lookup){
#ifdef BPF_TRACE
bpf_trace_printk("[switch-%d]: mac EGRESS %lx mismatch %lx -> DROP\n",
md->module_id, PRINT_MAC(eth->dst), PRINT_MAC(*mac_lookup));
#endif
return RX_DROP;
}
#endif
/* do not send packet back on the ingress interface */
if (*dst_interface == in_ifc)
return RX_DROP;
pkt_redirect(skb, md, *dst_interface);
#ifdef BPF_TRACE
bpf_trace_printk("[switch-%d]: redirect out_ifc=%d\n", md->module_id, *dst_interface);
#endif
return RX_REDIRECT;
} else {
#ifdef BPF_TRACE
bpf_trace_printk("[switch-%d]: Broadcast\n", md->module_id);
#endif
pkt_controller(skb, md, PKT_BROADCAST);
return RX_CONTROLLER;
}
}