support ebpf

2022-07-29 09:08:35 +08:00
parent 57a15088c2
commit 31f4d20477
30 changed files with 6270 additions and 8 deletions
--- a/component/ebpf/bpf/tc.c
+++ b/component/ebpf/bpf/tc.c
@@ -0,0 +1,103 @@
+#include <stdbool.h>
+#include <linux/bpf.h>
+#include <linux/if_ether.h>
+#include <linux/ip.h>
+#include <linux/in.h>
+//#include <linux/tcp.h>
+//#include <linux/udp.h>
+#include <linux/pkt_cls.h>
+
+#include "bpf_endian.h"
+#include "bpf_helpers.h"
+
+struct {
+    __uint(type, BPF_MAP_TYPE_ARRAY);
+    __type(key, __u32);
+    __type(value, __u32);
+    __uint(max_entries, 2);
+    __uint(pinning, LIBBPF_PIN_BY_NAME);
+} tc_params_map SEC(".maps");
+
+static __always_inline bool is_lan_ip(__be32 addr) {
+    if (addr == 0xffffffff)
+        return true;
+
+    __u8 fist = (__u8)(addr & 0xff);
+
+    if (fist == 127 || fist == 10)
+        return true;
+
+    __u8 second = (__u8)((addr >> 8) & 0xff);
+
+    if (fist == 172 && second >= 16 && second <= 31)
+        return true;
+
+    if (fist == 192 && second == 168)
+        return true;
+
+    return false;
+}
+
+SEC("tc_clash_redirect_to_tun")
+int tc_tun_func(struct __sk_buff *skb) {
+    void *data          = (void *)(long)skb->data;
+    void *data_end      = (void *)(long)skb->data_end;
+    struct ethhdr *eth  = data;
+
+    if ((void *)(eth + 1) > data_end)
+        return TC_ACT_OK;
+
+    if (eth->h_proto == bpf_htons(ETH_P_ARP))
+        return TC_ACT_OK;
+
+    __u32 key = 0, *clash_mark, *tun_ifindex;
+
+    clash_mark = bpf_map_lookup_elem(&tc_params_map, &key);
+    if (!clash_mark)
+        return TC_ACT_OK;
+
+    if (skb->mark == *clash_mark)
+        return TC_ACT_OK;
+
+    if (eth->h_proto == bpf_htons(ETH_P_IP)) {
+        struct iphdr *iph = (struct iphdr *)(eth + 1);
+        if ((void *)(iph + 1) > data_end)
+            return TC_ACT_OK;
+
+        if (iph->protocol == IPPROTO_ICMP)
+            return TC_ACT_OK;
+
+        __be32 daddr = iph->daddr;
+
+        if (is_lan_ip(daddr))
+            return TC_ACT_OK;
+
+//        if (iph->protocol == IPPROTO_TCP) {
+//            struct tcphdr *tcph = (struct tcphdr *)(iph + 1);
+//            if ((void *)(tcph + 1) > data_end)
+//                return TC_ACT_OK;
+//
+//            __u16 source = bpf_ntohs(tcph->source);
+//            if (source == 22 || source == 80 || source == 443 || source == 8080 || source == 8443 || source == 9090 || (source >= 7890 && source <= 7895))
+//                return TC_ACT_OK;
+//        } else if (iph->protocol == IPPROTO_UDP) {
+//            struct udphdr *udph = (struct udphdr *)(iph + 1);
+//            if ((void *)(udph + 1) > data_end)
+//                return TC_ACT_OK;
+//
+//            __u16 source = bpf_ntohs(udph->source);
+//            if (source == 53 || (source >= 135 && source <= 139))
+//                return TC_ACT_OK;
+//        }
+    }
+
+    key = 1;
+    tun_ifindex = bpf_map_lookup_elem(&tc_params_map, &key);
+    if (!tun_ifindex)
+        return TC_ACT_OK;
+
+    //return bpf_redirect(*tun_ifindex, BPF_F_INGRESS); // __bpf_rx_skb
+    return bpf_redirect(*tun_ifindex, 0); // __bpf_tx_skb / __dev_xmit_skb
+}
+
+char _license[] SEC("license") = "GPL";