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-rw-r--r--samples/bpf/xdp_redirect_cpu.bpf.c539
1 files changed, 539 insertions, 0 deletions
diff --git a/samples/bpf/xdp_redirect_cpu.bpf.c b/samples/bpf/xdp_redirect_cpu.bpf.c
new file mode 100644
index 000000000..87c54bfdb
--- /dev/null
+++ b/samples/bpf/xdp_redirect_cpu.bpf.c
@@ -0,0 +1,539 @@
+/* XDP redirect to CPUs via cpumap (BPF_MAP_TYPE_CPUMAP)
+ *
+ * GPLv2, Copyright(c) 2017 Jesper Dangaard Brouer, Red Hat, Inc.
+ */
+#include "vmlinux.h"
+#include "xdp_sample.bpf.h"
+#include "xdp_sample_shared.h"
+#include "hash_func01.h"
+
+/* Special map type that can XDP_REDIRECT frames to another CPU */
+struct {
+ __uint(type, BPF_MAP_TYPE_CPUMAP);
+ __uint(key_size, sizeof(u32));
+ __uint(value_size, sizeof(struct bpf_cpumap_val));
+} cpu_map SEC(".maps");
+
+/* Set of maps controlling available CPU, and for iterating through
+ * selectable redirect CPUs.
+ */
+struct {
+ __uint(type, BPF_MAP_TYPE_ARRAY);
+ __type(key, u32);
+ __type(value, u32);
+} cpus_available SEC(".maps");
+
+struct {
+ __uint(type, BPF_MAP_TYPE_ARRAY);
+ __type(key, u32);
+ __type(value, u32);
+ __uint(max_entries, 1);
+} cpus_count SEC(".maps");
+
+struct {
+ __uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
+ __type(key, u32);
+ __type(value, u32);
+ __uint(max_entries, 1);
+} cpus_iterator SEC(".maps");
+
+struct {
+ __uint(type, BPF_MAP_TYPE_DEVMAP);
+ __uint(key_size, sizeof(int));
+ __uint(value_size, sizeof(struct bpf_devmap_val));
+ __uint(max_entries, 1);
+} tx_port SEC(".maps");
+
+char tx_mac_addr[ETH_ALEN];
+
+/* Helper parse functions */
+
+static __always_inline
+bool parse_eth(struct ethhdr *eth, void *data_end,
+ u16 *eth_proto, u64 *l3_offset)
+{
+ u16 eth_type;
+ u64 offset;
+
+ offset = sizeof(*eth);
+ if ((void *)eth + offset > data_end)
+ return false;
+
+ eth_type = eth->h_proto;
+
+ /* Skip non 802.3 Ethertypes */
+ if (__builtin_expect(bpf_ntohs(eth_type) < ETH_P_802_3_MIN, 0))
+ return false;
+
+ /* Handle VLAN tagged packet */
+ if (eth_type == bpf_htons(ETH_P_8021Q) ||
+ eth_type == bpf_htons(ETH_P_8021AD)) {
+ struct vlan_hdr *vlan_hdr;
+
+ vlan_hdr = (void *)eth + offset;
+ offset += sizeof(*vlan_hdr);
+ if ((void *)eth + offset > data_end)
+ return false;
+ eth_type = vlan_hdr->h_vlan_encapsulated_proto;
+ }
+ /* Handle double VLAN tagged packet */
+ if (eth_type == bpf_htons(ETH_P_8021Q) ||
+ eth_type == bpf_htons(ETH_P_8021AD)) {
+ struct vlan_hdr *vlan_hdr;
+
+ vlan_hdr = (void *)eth + offset;
+ offset += sizeof(*vlan_hdr);
+ if ((void *)eth + offset > data_end)
+ return false;
+ eth_type = vlan_hdr->h_vlan_encapsulated_proto;
+ }
+
+ *eth_proto = bpf_ntohs(eth_type);
+ *l3_offset = offset;
+ return true;
+}
+
+static __always_inline
+u16 get_dest_port_ipv4_udp(struct xdp_md *ctx, u64 nh_off)
+{
+ void *data_end = (void *)(long)ctx->data_end;
+ void *data = (void *)(long)ctx->data;
+ struct iphdr *iph = data + nh_off;
+ struct udphdr *udph;
+
+ if (iph + 1 > data_end)
+ return 0;
+ if (!(iph->protocol == IPPROTO_UDP))
+ return 0;
+
+ udph = (void *)(iph + 1);
+ if (udph + 1 > data_end)
+ return 0;
+
+ return bpf_ntohs(udph->dest);
+}
+
+static __always_inline
+int get_proto_ipv4(struct xdp_md *ctx, u64 nh_off)
+{
+ void *data_end = (void *)(long)ctx->data_end;
+ void *data = (void *)(long)ctx->data;
+ struct iphdr *iph = data + nh_off;
+
+ if (iph + 1 > data_end)
+ return 0;
+ return iph->protocol;
+}
+
+static __always_inline
+int get_proto_ipv6(struct xdp_md *ctx, u64 nh_off)
+{
+ void *data_end = (void *)(long)ctx->data_end;
+ void *data = (void *)(long)ctx->data;
+ struct ipv6hdr *ip6h = data + nh_off;
+
+ if (ip6h + 1 > data_end)
+ return 0;
+ return ip6h->nexthdr;
+}
+
+SEC("xdp")
+int xdp_prognum0_no_touch(struct xdp_md *ctx)
+{
+ u32 key = bpf_get_smp_processor_id();
+ struct datarec *rec;
+ u32 *cpu_selected;
+ u32 cpu_dest = 0;
+ u32 key0 = 0;
+
+ /* Only use first entry in cpus_available */
+ cpu_selected = bpf_map_lookup_elem(&cpus_available, &key0);
+ if (!cpu_selected)
+ return XDP_ABORTED;
+ cpu_dest = *cpu_selected;
+
+ rec = bpf_map_lookup_elem(&rx_cnt, &key);
+ if (!rec)
+ return XDP_PASS;
+ NO_TEAR_INC(rec->processed);
+
+ if (cpu_dest >= nr_cpus) {
+ NO_TEAR_INC(rec->issue);
+ return XDP_ABORTED;
+ }
+ return bpf_redirect_map(&cpu_map, cpu_dest, 0);
+}
+
+SEC("xdp")
+int xdp_prognum1_touch_data(struct xdp_md *ctx)
+{
+ void *data_end = (void *)(long)ctx->data_end;
+ void *data = (void *)(long)ctx->data;
+ u32 key = bpf_get_smp_processor_id();
+ struct ethhdr *eth = data;
+ struct datarec *rec;
+ u32 *cpu_selected;
+ u32 cpu_dest = 0;
+ u32 key0 = 0;
+ u16 eth_type;
+
+ /* Only use first entry in cpus_available */
+ cpu_selected = bpf_map_lookup_elem(&cpus_available, &key0);
+ if (!cpu_selected)
+ return XDP_ABORTED;
+ cpu_dest = *cpu_selected;
+
+ /* Validate packet length is minimum Eth header size */
+ if (eth + 1 > data_end)
+ return XDP_ABORTED;
+
+ rec = bpf_map_lookup_elem(&rx_cnt, &key);
+ if (!rec)
+ return XDP_PASS;
+ NO_TEAR_INC(rec->processed);
+
+ /* Read packet data, and use it (drop non 802.3 Ethertypes) */
+ eth_type = eth->h_proto;
+ if (bpf_ntohs(eth_type) < ETH_P_802_3_MIN) {
+ NO_TEAR_INC(rec->dropped);
+ return XDP_DROP;
+ }
+
+ if (cpu_dest >= nr_cpus) {
+ NO_TEAR_INC(rec->issue);
+ return XDP_ABORTED;
+ }
+ return bpf_redirect_map(&cpu_map, cpu_dest, 0);
+}
+
+SEC("xdp")
+int xdp_prognum2_round_robin(struct xdp_md *ctx)
+{
+ void *data_end = (void *)(long)ctx->data_end;
+ void *data = (void *)(long)ctx->data;
+ u32 key = bpf_get_smp_processor_id();
+ struct datarec *rec;
+ u32 cpu_dest = 0;
+ u32 key0 = 0;
+
+ u32 *cpu_selected;
+ u32 *cpu_iterator;
+ u32 *cpu_max;
+ u32 cpu_idx;
+
+ cpu_max = bpf_map_lookup_elem(&cpus_count, &key0);
+ if (!cpu_max)
+ return XDP_ABORTED;
+
+ cpu_iterator = bpf_map_lookup_elem(&cpus_iterator, &key0);
+ if (!cpu_iterator)
+ return XDP_ABORTED;
+ cpu_idx = *cpu_iterator;
+
+ *cpu_iterator += 1;
+ if (*cpu_iterator == *cpu_max)
+ *cpu_iterator = 0;
+
+ cpu_selected = bpf_map_lookup_elem(&cpus_available, &cpu_idx);
+ if (!cpu_selected)
+ return XDP_ABORTED;
+ cpu_dest = *cpu_selected;
+
+ rec = bpf_map_lookup_elem(&rx_cnt, &key);
+ if (!rec)
+ return XDP_PASS;
+ NO_TEAR_INC(rec->processed);
+
+ if (cpu_dest >= nr_cpus) {
+ NO_TEAR_INC(rec->issue);
+ return XDP_ABORTED;
+ }
+ return bpf_redirect_map(&cpu_map, cpu_dest, 0);
+}
+
+SEC("xdp")
+int xdp_prognum3_proto_separate(struct xdp_md *ctx)
+{
+ void *data_end = (void *)(long)ctx->data_end;
+ void *data = (void *)(long)ctx->data;
+ u32 key = bpf_get_smp_processor_id();
+ struct ethhdr *eth = data;
+ u8 ip_proto = IPPROTO_UDP;
+ struct datarec *rec;
+ u16 eth_proto = 0;
+ u64 l3_offset = 0;
+ u32 cpu_dest = 0;
+ u32 *cpu_lookup;
+ u32 cpu_idx = 0;
+
+ rec = bpf_map_lookup_elem(&rx_cnt, &key);
+ if (!rec)
+ return XDP_PASS;
+ NO_TEAR_INC(rec->processed);
+
+ if (!(parse_eth(eth, data_end, &eth_proto, &l3_offset)))
+ return XDP_PASS; /* Just skip */
+
+ /* Extract L4 protocol */
+ switch (eth_proto) {
+ case ETH_P_IP:
+ ip_proto = get_proto_ipv4(ctx, l3_offset);
+ break;
+ case ETH_P_IPV6:
+ ip_proto = get_proto_ipv6(ctx, l3_offset);
+ break;
+ case ETH_P_ARP:
+ cpu_idx = 0; /* ARP packet handled on separate CPU */
+ break;
+ default:
+ cpu_idx = 0;
+ }
+
+ /* Choose CPU based on L4 protocol */
+ switch (ip_proto) {
+ case IPPROTO_ICMP:
+ case IPPROTO_ICMPV6:
+ cpu_idx = 2;
+ break;
+ case IPPROTO_TCP:
+ cpu_idx = 0;
+ break;
+ case IPPROTO_UDP:
+ cpu_idx = 1;
+ break;
+ default:
+ cpu_idx = 0;
+ }
+
+ cpu_lookup = bpf_map_lookup_elem(&cpus_available, &cpu_idx);
+ if (!cpu_lookup)
+ return XDP_ABORTED;
+ cpu_dest = *cpu_lookup;
+
+ if (cpu_dest >= nr_cpus) {
+ NO_TEAR_INC(rec->issue);
+ return XDP_ABORTED;
+ }
+ return bpf_redirect_map(&cpu_map, cpu_dest, 0);
+}
+
+SEC("xdp")
+int xdp_prognum4_ddos_filter_pktgen(struct xdp_md *ctx)
+{
+ void *data_end = (void *)(long)ctx->data_end;
+ void *data = (void *)(long)ctx->data;
+ u32 key = bpf_get_smp_processor_id();
+ struct ethhdr *eth = data;
+ u8 ip_proto = IPPROTO_UDP;
+ struct datarec *rec;
+ u16 eth_proto = 0;
+ u64 l3_offset = 0;
+ u32 cpu_dest = 0;
+ u32 *cpu_lookup;
+ u32 cpu_idx = 0;
+ u16 dest_port;
+
+ rec = bpf_map_lookup_elem(&rx_cnt, &key);
+ if (!rec)
+ return XDP_PASS;
+ NO_TEAR_INC(rec->processed);
+
+ if (!(parse_eth(eth, data_end, &eth_proto, &l3_offset)))
+ return XDP_PASS; /* Just skip */
+
+ /* Extract L4 protocol */
+ switch (eth_proto) {
+ case ETH_P_IP:
+ ip_proto = get_proto_ipv4(ctx, l3_offset);
+ break;
+ case ETH_P_IPV6:
+ ip_proto = get_proto_ipv6(ctx, l3_offset);
+ break;
+ case ETH_P_ARP:
+ cpu_idx = 0; /* ARP packet handled on separate CPU */
+ break;
+ default:
+ cpu_idx = 0;
+ }
+
+ /* Choose CPU based on L4 protocol */
+ switch (ip_proto) {
+ case IPPROTO_ICMP:
+ case IPPROTO_ICMPV6:
+ cpu_idx = 2;
+ break;
+ case IPPROTO_TCP:
+ cpu_idx = 0;
+ break;
+ case IPPROTO_UDP:
+ cpu_idx = 1;
+ /* DDoS filter UDP port 9 (pktgen) */
+ dest_port = get_dest_port_ipv4_udp(ctx, l3_offset);
+ if (dest_port == 9) {
+ NO_TEAR_INC(rec->dropped);
+ return XDP_DROP;
+ }
+ break;
+ default:
+ cpu_idx = 0;
+ }
+
+ cpu_lookup = bpf_map_lookup_elem(&cpus_available, &cpu_idx);
+ if (!cpu_lookup)
+ return XDP_ABORTED;
+ cpu_dest = *cpu_lookup;
+
+ if (cpu_dest >= nr_cpus) {
+ NO_TEAR_INC(rec->issue);
+ return XDP_ABORTED;
+ }
+ return bpf_redirect_map(&cpu_map, cpu_dest, 0);
+}
+
+/* Hashing initval */
+#define INITVAL 15485863
+
+static __always_inline
+u32 get_ipv4_hash_ip_pair(struct xdp_md *ctx, u64 nh_off)
+{
+ void *data_end = (void *)(long)ctx->data_end;
+ void *data = (void *)(long)ctx->data;
+ struct iphdr *iph = data + nh_off;
+ u32 cpu_hash;
+
+ if (iph + 1 > data_end)
+ return 0;
+
+ cpu_hash = iph->saddr + iph->daddr;
+ cpu_hash = SuperFastHash((char *)&cpu_hash, 4, INITVAL + iph->protocol);
+
+ return cpu_hash;
+}
+
+static __always_inline
+u32 get_ipv6_hash_ip_pair(struct xdp_md *ctx, u64 nh_off)
+{
+ void *data_end = (void *)(long)ctx->data_end;
+ void *data = (void *)(long)ctx->data;
+ struct ipv6hdr *ip6h = data + nh_off;
+ u32 cpu_hash;
+
+ if (ip6h + 1 > data_end)
+ return 0;
+
+ cpu_hash = ip6h->saddr.in6_u.u6_addr32[0] + ip6h->daddr.in6_u.u6_addr32[0];
+ cpu_hash += ip6h->saddr.in6_u.u6_addr32[1] + ip6h->daddr.in6_u.u6_addr32[1];
+ cpu_hash += ip6h->saddr.in6_u.u6_addr32[2] + ip6h->daddr.in6_u.u6_addr32[2];
+ cpu_hash += ip6h->saddr.in6_u.u6_addr32[3] + ip6h->daddr.in6_u.u6_addr32[3];
+ cpu_hash = SuperFastHash((char *)&cpu_hash, 4, INITVAL + ip6h->nexthdr);
+
+ return cpu_hash;
+}
+
+/* Load-Balance traffic based on hashing IP-addrs + L4-proto. The
+ * hashing scheme is symmetric, meaning swapping IP src/dest still hit
+ * same CPU.
+ */
+SEC("xdp")
+int xdp_prognum5_lb_hash_ip_pairs(struct xdp_md *ctx)
+{
+ void *data_end = (void *)(long)ctx->data_end;
+ void *data = (void *)(long)ctx->data;
+ u32 key = bpf_get_smp_processor_id();
+ struct ethhdr *eth = data;
+ struct datarec *rec;
+ u16 eth_proto = 0;
+ u64 l3_offset = 0;
+ u32 cpu_dest = 0;
+ u32 cpu_idx = 0;
+ u32 *cpu_lookup;
+ u32 key0 = 0;
+ u32 *cpu_max;
+ u32 cpu_hash;
+
+ rec = bpf_map_lookup_elem(&rx_cnt, &key);
+ if (!rec)
+ return XDP_PASS;
+ NO_TEAR_INC(rec->processed);
+
+ cpu_max = bpf_map_lookup_elem(&cpus_count, &key0);
+ if (!cpu_max)
+ return XDP_ABORTED;
+
+ if (!(parse_eth(eth, data_end, &eth_proto, &l3_offset)))
+ return XDP_PASS; /* Just skip */
+
+ /* Hash for IPv4 and IPv6 */
+ switch (eth_proto) {
+ case ETH_P_IP:
+ cpu_hash = get_ipv4_hash_ip_pair(ctx, l3_offset);
+ break;
+ case ETH_P_IPV6:
+ cpu_hash = get_ipv6_hash_ip_pair(ctx, l3_offset);
+ break;
+ case ETH_P_ARP: /* ARP packet handled on CPU idx 0 */
+ default:
+ cpu_hash = 0;
+ }
+
+ /* Choose CPU based on hash */
+ cpu_idx = cpu_hash % *cpu_max;
+
+ cpu_lookup = bpf_map_lookup_elem(&cpus_available, &cpu_idx);
+ if (!cpu_lookup)
+ return XDP_ABORTED;
+ cpu_dest = *cpu_lookup;
+
+ if (cpu_dest >= nr_cpus) {
+ NO_TEAR_INC(rec->issue);
+ return XDP_ABORTED;
+ }
+ return bpf_redirect_map(&cpu_map, cpu_dest, 0);
+}
+
+SEC("xdp/cpumap")
+int xdp_redirect_cpu_devmap(struct xdp_md *ctx)
+{
+ void *data_end = (void *)(long)ctx->data_end;
+ void *data = (void *)(long)ctx->data;
+ struct ethhdr *eth = data;
+ u64 nh_off;
+
+ nh_off = sizeof(*eth);
+ if (data + nh_off > data_end)
+ return XDP_DROP;
+
+ swap_src_dst_mac(data);
+ return bpf_redirect_map(&tx_port, 0, 0);
+}
+
+SEC("xdp/cpumap")
+int xdp_redirect_cpu_pass(struct xdp_md *ctx)
+{
+ return XDP_PASS;
+}
+
+SEC("xdp/cpumap")
+int xdp_redirect_cpu_drop(struct xdp_md *ctx)
+{
+ return XDP_DROP;
+}
+
+SEC("xdp/devmap")
+int xdp_redirect_egress_prog(struct xdp_md *ctx)
+{
+ void *data_end = (void *)(long)ctx->data_end;
+ void *data = (void *)(long)ctx->data;
+ struct ethhdr *eth = data;
+ u64 nh_off;
+
+ nh_off = sizeof(*eth);
+ if (data + nh_off > data_end)
+ return XDP_DROP;
+
+ __builtin_memcpy(eth->h_source, (const char *)tx_mac_addr, ETH_ALEN);
+
+ return XDP_PASS;
+}
+
+char _license[] SEC("license") = "GPL";
generated by cgit v1.2.3 (git 2.39.1) at 2024-05-17 17:49:14 +0000