drgn.helpers.linux.net: add basic skb_dump helper

Signed-off-by: Mina Almasry <[email protected]>

drgn/helpers/linux/net.py

@@ -35,6 +35,7 @@
     "skb_is_nonlinear",
     "skb_tailroom",
     "skb_availroom",
+    "skb_dump",
 )
 
 
@@ -315,3 +316,32 @@ def skb_mac_header_was_set(skb: Object) -> int:
 def skb_transport_header_was_set(skb: Object) -> int:
     prog = skb.prog_
     return skb.transport_header != 65535;
+
+
+def skb_dump(skb: Object) -> None:
+    prog = skb.prog_
+
+    headroom = skb_headroom(skb)
+    tailroom = skb_tailroom(skb)
+    sh = skb_shinfo(skb)
+
+    has_mac = skb_mac_header_was_set(skb)
+    has_trans = skb_transport_header_was_set(skb)
+
+    print("skb len=%u headroom=%u headlen=%u tailroom=%u\n"
+          "mac=(%d,%d) net=(%d,%d) trans=%d\n"
+          "shinfo(txflags=%u nr_frags=%u gso(size=%hu type=%u segs=%hu))\n"
+          "csum(0x%x ip_summed=%u complete_sw=%u valid=%u level=%u)\n"
+          "hash(0x%x sw=%u l4=%u) proto=0x%04x pkttype=%u iif=%d\n" %
+          (skb.len, headroom, skb_headlen(skb), tailroom,
+           skb.mac_header if has_mac else  -1,
+           skb_mac_header_len(skb) if has_mac else -1,
+           skb.network_header,
+           skb_network_header_len(skb) if has_trans else -1,
+           skb.transport_header if has_trans else -1,
+           sh.tx_flags, sh.nr_frags,
+           sh.gso_size, sh.gso_type, sh.gso_segs,
+           skb.csum, skb.ip_summed, skb.csum_complete_sw,
+           skb.csum_valid, skb.csum_level,
+           skb.hash, skb.sw_hash, skb.l4_hash,
+           skb.protocol, skb.pkt_type, skb.skb_iif))