Code changes

Signed-off-by: Dan Finneran <[email protected]>
isovalent · Sep 6, 2024 · 64ba76d · 64ba76d
1 parent 962d2e0
commit 64ba76d
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Showing 2 changed files with 39 additions and 45 deletions.
diff --git a/eBPF/redirect/ebpf/redirect.c b/eBPF/redirect/ebpf/redirect.c
@@ -49,9 +49,6 @@ static inline int redirect_tcp(struct __sk_buff *skb, bool ingress) {
       return TC_ACT_OK;
     }
     __u32 ip_hlen = 0;
-    //__u32 poffset = 0;
-    //__u32 plength = 0;
-    // __u32 ip_total_length = bpf_ntohs(iph->tot_len);
 
     ip_hlen = iph->ihl << 2;
 
@@ -72,15 +69,17 @@ static inline int redirect_tcp(struct __sk_buff *skb, bool ingress) {
       bpf_printk("bpf_skb_load_bytes eth failed");
       return TC_ACT_OK;
     }
-    __u16 source = bpf_htons(tcp.source);
-    __u16 dest = bpf_htons(tcp.dest);
+
+    // something doesn't seem right here
+    __u16 source = tcp.source;
+    __u16 dest = tcp.dest;
 
     bpf_printk("ingress:%s source: %d -> destination %d",
                ingress ? "true" : "false", source, dest);
 
     if (ingress) {
       if (dest == 2001) {
-        tcp.dest = bpf_ntohs(2000);
+        tcp.dest = 2000;
         long ret =
             bpf_skb_store_bytes(skb, sizeof(struct ethhdr) + (ip.ihl << 2),
                                 &tcp, sizeof(tcp), BPF_F_RECOMPUTE_CSUM);
@@ -89,41 +88,34 @@ static inline int redirect_tcp(struct __sk_buff *skb, bool ingress) {
         }
       }
     } else {
-      if (source == 2000) {
-        tcp.source = bpf_ntohs(2001);
-        long ret =
-            bpf_skb_store_bytes(skb, sizeof(struct ethhdr) + (ip.ihl << 2),
-                                &tcp, sizeof(tcp), BPF_F_RECOMPUTE_CSUM);
-        if (ret != 0) {
-          bpf_printk("Error writing bytes");
-        }
-      }
+      //
     }
   }
+}
 
-  /*
-  15:27:27.195146 IP (tos 0x0, ttl 64, id 64035, offset 0, flags [DF], proto TCP
-  (6), length 60) 127.0.0.1.55590 > 127.0.0.1.2001: Flags [S], cksum 0xfe30
-  (incorrect -> 0xde8f), seq 1127217463, win 65495, options [mss 65495,sackOK,TS
-  val 1342243858 ecr 0,nop,wscale 7], length 0 15:27:27.195160 IP (tos 0x0, ttl
-  64, id 0, offset 0, flags [DF], proto TCP (6), length 40) 127.0.0.1.2001 >
-  127.0.0.1.55590: Flags [R.], cksum 0x946e (correct), seq 0, ack 1127217464,
-  win 0, length 0
-
-     15:27:19.192319 IP (tos 0x0, ttl 64, id 57861, offset 0, flags [DF], proto
-  TCP (6), length 60) 127.0.0.1.50720 > 127.0.0.1.2001: Flags [S], cksum 0xfe30
-  (incorrect -> 0xb3db), seq 1553087697, win 65495, options [mss 65495,sackOK,TS
-  val 1342235856 ecr 0,nop,wscale 7], length 0 15:27:19.192345 IP (tos 0x0, ttl
-  64, id 0, offset 0, flags [DF], proto TCP (6), length 60) 127.0.0.1.2000 >
-  127.0.0.1.50720: Flags [S.], cksum 0xfe30 (incorrect -> 0x7bf5), seq
-  2242477415, ack 1553087698, win 65483, options [mss 65495,sackOK,TS val
-  1342235856 ecr 1342235856,nop,wscale 7], length 0 15:27:19.192359 IP (tos 0x0,
-  ttl 64, id 0, offset 0, flags [DF], proto TCP (6), length 40) 127.0.0.1.50720
-  > 127.0.0.1.2001: Flags [R], cksum 0x4a89 (incorrect -> 0x4a88), seq
-  1553087698, win 0, length 0
-      */
-
-  return TC_ACT_OK;
+/*
+15:27:27.195146 IP (tos 0x0, ttl 64, id 64035, offset 0, flags [DF], proto TCP
+(6), length 60) 127.0.0.1.55590 > 127.0.0.1.2001: Flags [S], cksum 0xfe30
+(incorrect -> 0xde8f), seq 1127217463, win 65495, options [mss 65495,sackOK,TS
+val 1342243858 ecr 0,nop,wscale 7], length 0 15:27:27.195160 IP (tos 0x0, ttl
+64, id 0, offset 0, flags [DF], proto TCP (6), length 40) 127.0.0.1.2001 >
+127.0.0.1.55590: Flags [R.], cksum 0x946e (correct), seq 0, ack 1127217464,
+win 0, length 0
+
+   15:27:19.192319 IP (tos 0x0, ttl 64, id 57861, offset 0, flags [DF], proto
+TCP (6), length 60) 127.0.0.1.50720 > 127.0.0.1.2001: Flags [S], cksum 0xfe30
+(incorrect -> 0xb3db), seq 1553087697, win 65495, options [mss 65495,sackOK,TS
+val 1342235856 ecr 0,nop,wscale 7], length 0 15:27:19.192345 IP (tos 0x0, ttl
+64, id 0, offset 0, flags [DF], proto TCP (6), length 60) 127.0.0.1.2000 >
+127.0.0.1.50720: Flags [S.], cksum 0xfe30 (incorrect -> 0x7bf5), seq
+2242477415, ack 1553087698, win 65483, options [mss 65495,sackOK,TS val
+1342235856 ecr 1342235856,nop,wscale 7], length 0 15:27:19.192359 IP (tos 0x0,
+ttl 64, id 0, offset 0, flags [DF], proto TCP (6), length 40) 127.0.0.1.50720
+> 127.0.0.1.2001: Flags [R], cksum 0x4a89 (incorrect -> 0x4a88), seq
+1553087698, win 0, length 0
+    */
+
+return TC_ACT_OK;
 }
 
 // eBPF hooks - This is where the magic happens!

diff --git a/eBPF/response/ebpf/response.c b/eBPF/response/ebpf/response.c
@@ -90,6 +90,15 @@ static inline int swap_udp(struct __sk_buff *skb) {
       data[3] = '\0'; // null terminate the string
       bpf_printk("data: %s", data);
 
+      u32 data_offset = sizeof(*eth) + sizeof(*iph) + sizeof(*udph);
+
+      data[0] = '?';
+
+      ret = bpf_skb_store_bytes(skb, data_offset, &data, sizeof(data),
+                                BPF_F_RECOMPUTE_CSUM);
+
+      // Something doesn't seem right
+
       /* We'll store the mac addresses (L2) */
       __u8 src_mac[ETH_ALEN];
       __u8 dst_mac[ETH_ALEN];
@@ -133,13 +142,6 @@ static inline int swap_udp(struct __sk_buff *skb) {
                               offsetof(struct udphdr, dest),
                           &src_port, sizeof(src_port), 0);
 
-      u32 data_offset = sizeof(*eth) + sizeof(*iph) + sizeof(*udph);
-
-      data[0] = '?';
-
-      ret = bpf_skb_store_bytes(skb, data_offset, &data, sizeof(data),
-                                BPF_F_RECOMPUTE_CSUM);
-
       /* And then send it back from wherever it's come from */
       ret = bpf_clone_redirect(skb, skb->ifindex, 0);
       if (ret) {