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-rw-r--r--tools/testing/selftests/bpf/progs/test_l4lb.c473
1 files changed, 473 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/progs/test_l4lb.c b/tools/testing/selftests/bpf/progs/test_l4lb.c
new file mode 100644
index 000000000..33493911d
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/test_l4lb.c
@@ -0,0 +1,473 @@
+/* Copyright (c) 2017 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+#include <stddef.h>
+#include <stdbool.h>
+#include <string.h>
+#include <linux/pkt_cls.h>
+#include <linux/bpf.h>
+#include <linux/in.h>
+#include <linux/if_ether.h>
+#include <linux/ip.h>
+#include <linux/ipv6.h>
+#include <linux/icmp.h>
+#include <linux/icmpv6.h>
+#include <linux/tcp.h>
+#include <linux/udp.h>
+#include <bpf/bpf_helpers.h>
+#include "test_iptunnel_common.h"
+#include <bpf/bpf_endian.h>
+
+int _version SEC("version") = 1;
+
+static inline __u32 rol32(__u32 word, unsigned int shift)
+{
+ return (word << shift) | (word >> ((-shift) & 31));
+}
+
+/* copy paste of jhash from kernel sources to make sure llvm
+ * can compile it into valid sequence of bpf instructions
+ */
+#define __jhash_mix(a, b, c) \
+{ \
+ a -= c; a ^= rol32(c, 4); c += b; \
+ b -= a; b ^= rol32(a, 6); a += c; \
+ c -= b; c ^= rol32(b, 8); b += a; \
+ a -= c; a ^= rol32(c, 16); c += b; \
+ b -= a; b ^= rol32(a, 19); a += c; \
+ c -= b; c ^= rol32(b, 4); b += a; \
+}
+
+#define __jhash_final(a, b, c) \
+{ \
+ c ^= b; c -= rol32(b, 14); \
+ a ^= c; a -= rol32(c, 11); \
+ b ^= a; b -= rol32(a, 25); \
+ c ^= b; c -= rol32(b, 16); \
+ a ^= c; a -= rol32(c, 4); \
+ b ^= a; b -= rol32(a, 14); \
+ c ^= b; c -= rol32(b, 24); \
+}
+
+#define JHASH_INITVAL 0xdeadbeef
+
+typedef unsigned int u32;
+
+static inline u32 jhash(const void *key, u32 length, u32 initval)
+{
+ u32 a, b, c;
+ const unsigned char *k = key;
+
+ a = b = c = JHASH_INITVAL + length + initval;
+
+ while (length > 12) {
+ a += *(u32 *)(k);
+ b += *(u32 *)(k + 4);
+ c += *(u32 *)(k + 8);
+ __jhash_mix(a, b, c);
+ length -= 12;
+ k += 12;
+ }
+ switch (length) {
+ case 12: c += (u32)k[11]<<24;
+ case 11: c += (u32)k[10]<<16;
+ case 10: c += (u32)k[9]<<8;
+ case 9: c += k[8];
+ case 8: b += (u32)k[7]<<24;
+ case 7: b += (u32)k[6]<<16;
+ case 6: b += (u32)k[5]<<8;
+ case 5: b += k[4];
+ case 4: a += (u32)k[3]<<24;
+ case 3: a += (u32)k[2]<<16;
+ case 2: a += (u32)k[1]<<8;
+ case 1: a += k[0];
+ __jhash_final(a, b, c);
+ case 0: /* Nothing left to add */
+ break;
+ }
+
+ return c;
+}
+
+static inline u32 __jhash_nwords(u32 a, u32 b, u32 c, u32 initval)
+{
+ a += initval;
+ b += initval;
+ c += initval;
+ __jhash_final(a, b, c);
+ return c;
+}
+
+static inline u32 jhash_2words(u32 a, u32 b, u32 initval)
+{
+ return __jhash_nwords(a, b, 0, initval + JHASH_INITVAL + (2 << 2));
+}
+
+#define PCKT_FRAGMENTED 65343
+#define IPV4_HDR_LEN_NO_OPT 20
+#define IPV4_PLUS_ICMP_HDR 28
+#define IPV6_PLUS_ICMP_HDR 48
+#define RING_SIZE 2
+#define MAX_VIPS 12
+#define MAX_REALS 5
+#define CTL_MAP_SIZE 16
+#define CH_RINGS_SIZE (MAX_VIPS * RING_SIZE)
+#define F_IPV6 (1 << 0)
+#define F_HASH_NO_SRC_PORT (1 << 0)
+#define F_ICMP (1 << 0)
+#define F_SYN_SET (1 << 1)
+
+struct packet_description {
+ union {
+ __be32 src;
+ __be32 srcv6[4];
+ };
+ union {
+ __be32 dst;
+ __be32 dstv6[4];
+ };
+ union {
+ __u32 ports;
+ __u16 port16[2];
+ };
+ __u8 proto;
+ __u8 flags;
+};
+
+struct ctl_value {
+ union {
+ __u64 value;
+ __u32 ifindex;
+ __u8 mac[6];
+ };
+};
+
+struct vip_meta {
+ __u32 flags;
+ __u32 vip_num;
+};
+
+struct real_definition {
+ union {
+ __be32 dst;
+ __be32 dstv6[4];
+ };
+ __u8 flags;
+};
+
+struct vip_stats {
+ __u64 bytes;
+ __u64 pkts;
+};
+
+struct eth_hdr {
+ unsigned char eth_dest[ETH_ALEN];
+ unsigned char eth_source[ETH_ALEN];
+ unsigned short eth_proto;
+};
+
+struct {
+ __uint(type, BPF_MAP_TYPE_HASH);
+ __uint(max_entries, MAX_VIPS);
+ __type(key, struct vip);
+ __type(value, struct vip_meta);
+} vip_map SEC(".maps");
+
+struct {
+ __uint(type, BPF_MAP_TYPE_ARRAY);
+ __uint(max_entries, CH_RINGS_SIZE);
+ __type(key, __u32);
+ __type(value, __u32);
+} ch_rings SEC(".maps");
+
+struct {
+ __uint(type, BPF_MAP_TYPE_ARRAY);
+ __uint(max_entries, MAX_REALS);
+ __type(key, __u32);
+ __type(value, struct real_definition);
+} reals SEC(".maps");
+
+struct {
+ __uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
+ __uint(max_entries, MAX_VIPS);
+ __type(key, __u32);
+ __type(value, struct vip_stats);
+} stats SEC(".maps");
+
+struct {
+ __uint(type, BPF_MAP_TYPE_ARRAY);
+ __uint(max_entries, CTL_MAP_SIZE);
+ __type(key, __u32);
+ __type(value, struct ctl_value);
+} ctl_array SEC(".maps");
+
+static __always_inline __u32 get_packet_hash(struct packet_description *pckt,
+ bool ipv6)
+{
+ if (ipv6)
+ return jhash_2words(jhash(pckt->srcv6, 16, MAX_VIPS),
+ pckt->ports, CH_RINGS_SIZE);
+ else
+ return jhash_2words(pckt->src, pckt->ports, CH_RINGS_SIZE);
+}
+
+static __always_inline bool get_packet_dst(struct real_definition **real,
+ struct packet_description *pckt,
+ struct vip_meta *vip_info,
+ bool is_ipv6)
+{
+ __u32 hash = get_packet_hash(pckt, is_ipv6) % RING_SIZE;
+ __u32 key = RING_SIZE * vip_info->vip_num + hash;
+ __u32 *real_pos;
+
+ real_pos = bpf_map_lookup_elem(&ch_rings, &key);
+ if (!real_pos)
+ return false;
+ key = *real_pos;
+ *real = bpf_map_lookup_elem(&reals, &key);
+ if (!(*real))
+ return false;
+ return true;
+}
+
+static __always_inline int parse_icmpv6(void *data, void *data_end, __u64 off,
+ struct packet_description *pckt)
+{
+ struct icmp6hdr *icmp_hdr;
+ struct ipv6hdr *ip6h;
+
+ icmp_hdr = data + off;
+ if (icmp_hdr + 1 > data_end)
+ return TC_ACT_SHOT;
+ if (icmp_hdr->icmp6_type != ICMPV6_PKT_TOOBIG)
+ return TC_ACT_OK;
+ off += sizeof(struct icmp6hdr);
+ ip6h = data + off;
+ if (ip6h + 1 > data_end)
+ return TC_ACT_SHOT;
+ pckt->proto = ip6h->nexthdr;
+ pckt->flags |= F_ICMP;
+ memcpy(pckt->srcv6, ip6h->daddr.s6_addr32, 16);
+ memcpy(pckt->dstv6, ip6h->saddr.s6_addr32, 16);
+ return TC_ACT_UNSPEC;
+}
+
+static __always_inline int parse_icmp(void *data, void *data_end, __u64 off,
+ struct packet_description *pckt)
+{
+ struct icmphdr *icmp_hdr;
+ struct iphdr *iph;
+
+ icmp_hdr = data + off;
+ if (icmp_hdr + 1 > data_end)
+ return TC_ACT_SHOT;
+ if (icmp_hdr->type != ICMP_DEST_UNREACH ||
+ icmp_hdr->code != ICMP_FRAG_NEEDED)
+ return TC_ACT_OK;
+ off += sizeof(struct icmphdr);
+ iph = data + off;
+ if (iph + 1 > data_end)
+ return TC_ACT_SHOT;
+ if (iph->ihl != 5)
+ return TC_ACT_SHOT;
+ pckt->proto = iph->protocol;
+ pckt->flags |= F_ICMP;
+ pckt->src = iph->daddr;
+ pckt->dst = iph->saddr;
+ return TC_ACT_UNSPEC;
+}
+
+static __always_inline bool parse_udp(void *data, __u64 off, void *data_end,
+ struct packet_description *pckt)
+{
+ struct udphdr *udp;
+ udp = data + off;
+
+ if (udp + 1 > data_end)
+ return false;
+
+ if (!(pckt->flags & F_ICMP)) {
+ pckt->port16[0] = udp->source;
+ pckt->port16[1] = udp->dest;
+ } else {
+ pckt->port16[0] = udp->dest;
+ pckt->port16[1] = udp->source;
+ }
+ return true;
+}
+
+static __always_inline bool parse_tcp(void *data, __u64 off, void *data_end,
+ struct packet_description *pckt)
+{
+ struct tcphdr *tcp;
+
+ tcp = data + off;
+ if (tcp + 1 > data_end)
+ return false;
+
+ if (tcp->syn)
+ pckt->flags |= F_SYN_SET;
+
+ if (!(pckt->flags & F_ICMP)) {
+ pckt->port16[0] = tcp->source;
+ pckt->port16[1] = tcp->dest;
+ } else {
+ pckt->port16[0] = tcp->dest;
+ pckt->port16[1] = tcp->source;
+ }
+ return true;
+}
+
+static __always_inline int process_packet(void *data, __u64 off, void *data_end,
+ bool is_ipv6, struct __sk_buff *skb)
+{
+ void *pkt_start = (void *)(long)skb->data;
+ struct packet_description pckt = {};
+ struct eth_hdr *eth = pkt_start;
+ struct bpf_tunnel_key tkey = {};
+ struct vip_stats *data_stats;
+ struct real_definition *dst;
+ struct vip_meta *vip_info;
+ struct ctl_value *cval;
+ __u32 v4_intf_pos = 1;
+ __u32 v6_intf_pos = 2;
+ struct ipv6hdr *ip6h;
+ struct vip vip = {};
+ struct iphdr *iph;
+ int tun_flag = 0;
+ __u16 pkt_bytes;
+ __u64 iph_len;
+ __u32 ifindex;
+ __u8 protocol;
+ __u32 vip_num;
+ int action;
+
+ tkey.tunnel_ttl = 64;
+ if (is_ipv6) {
+ ip6h = data + off;
+ if (ip6h + 1 > data_end)
+ return TC_ACT_SHOT;
+
+ iph_len = sizeof(struct ipv6hdr);
+ protocol = ip6h->nexthdr;
+ pckt.proto = protocol;
+ pkt_bytes = bpf_ntohs(ip6h->payload_len);
+ off += iph_len;
+ if (protocol == IPPROTO_FRAGMENT) {
+ return TC_ACT_SHOT;
+ } else if (protocol == IPPROTO_ICMPV6) {
+ action = parse_icmpv6(data, data_end, off, &pckt);
+ if (action >= 0)
+ return action;
+ off += IPV6_PLUS_ICMP_HDR;
+ } else {
+ memcpy(pckt.srcv6, ip6h->saddr.s6_addr32, 16);
+ memcpy(pckt.dstv6, ip6h->daddr.s6_addr32, 16);
+ }
+ } else {
+ iph = data + off;
+ if (iph + 1 > data_end)
+ return TC_ACT_SHOT;
+ if (iph->ihl != 5)
+ return TC_ACT_SHOT;
+
+ protocol = iph->protocol;
+ pckt.proto = protocol;
+ pkt_bytes = bpf_ntohs(iph->tot_len);
+ off += IPV4_HDR_LEN_NO_OPT;
+
+ if (iph->frag_off & PCKT_FRAGMENTED)
+ return TC_ACT_SHOT;
+ if (protocol == IPPROTO_ICMP) {
+ action = parse_icmp(data, data_end, off, &pckt);
+ if (action >= 0)
+ return action;
+ off += IPV4_PLUS_ICMP_HDR;
+ } else {
+ pckt.src = iph->saddr;
+ pckt.dst = iph->daddr;
+ }
+ }
+ protocol = pckt.proto;
+
+ if (protocol == IPPROTO_TCP) {
+ if (!parse_tcp(data, off, data_end, &pckt))
+ return TC_ACT_SHOT;
+ } else if (protocol == IPPROTO_UDP) {
+ if (!parse_udp(data, off, data_end, &pckt))
+ return TC_ACT_SHOT;
+ } else {
+ return TC_ACT_SHOT;
+ }
+
+ if (is_ipv6)
+ memcpy(vip.daddr.v6, pckt.dstv6, 16);
+ else
+ vip.daddr.v4 = pckt.dst;
+
+ vip.dport = pckt.port16[1];
+ vip.protocol = pckt.proto;
+ vip_info = bpf_map_lookup_elem(&vip_map, &vip);
+ if (!vip_info) {
+ vip.dport = 0;
+ vip_info = bpf_map_lookup_elem(&vip_map, &vip);
+ if (!vip_info)
+ return TC_ACT_SHOT;
+ pckt.port16[1] = 0;
+ }
+
+ if (vip_info->flags & F_HASH_NO_SRC_PORT)
+ pckt.port16[0] = 0;
+
+ if (!get_packet_dst(&dst, &pckt, vip_info, is_ipv6))
+ return TC_ACT_SHOT;
+
+ if (dst->flags & F_IPV6) {
+ cval = bpf_map_lookup_elem(&ctl_array, &v6_intf_pos);
+ if (!cval)
+ return TC_ACT_SHOT;
+ ifindex = cval->ifindex;
+ memcpy(tkey.remote_ipv6, dst->dstv6, 16);
+ tun_flag = BPF_F_TUNINFO_IPV6;
+ } else {
+ cval = bpf_map_lookup_elem(&ctl_array, &v4_intf_pos);
+ if (!cval)
+ return TC_ACT_SHOT;
+ ifindex = cval->ifindex;
+ tkey.remote_ipv4 = dst->dst;
+ }
+ vip_num = vip_info->vip_num;
+ data_stats = bpf_map_lookup_elem(&stats, &vip_num);
+ if (!data_stats)
+ return TC_ACT_SHOT;
+ data_stats->pkts++;
+ data_stats->bytes += pkt_bytes;
+ bpf_skb_set_tunnel_key(skb, &tkey, sizeof(tkey), tun_flag);
+ *(u32 *)eth->eth_dest = tkey.remote_ipv4;
+ return bpf_redirect(ifindex, 0);
+}
+
+SEC("l4lb-demo")
+int balancer_ingress(struct __sk_buff *ctx)
+{
+ void *data_end = (void *)(long)ctx->data_end;
+ void *data = (void *)(long)ctx->data;
+ struct eth_hdr *eth = data;
+ __u32 eth_proto;
+ __u32 nh_off;
+
+ nh_off = sizeof(struct eth_hdr);
+ if (data + nh_off > data_end)
+ return TC_ACT_SHOT;
+ eth_proto = eth->eth_proto;
+ if (eth_proto == bpf_htons(ETH_P_IP))
+ return process_packet(data, nh_off, data_end, false, ctx);
+ else if (eth_proto == bpf_htons(ETH_P_IPV6))
+ return process_packet(data, nh_off, data_end, true, ctx);
+ else
+ return TC_ACT_SHOT;
+}
+char _license[] SEC("license") = "GPL";
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-03 18:23:13 +0000