From: Donatas Abraitis <donatas.abraitis@gmail.com>
Date: Wed, 22 Sep 2021 08:30:06 +0000 (+0300)
Subject: bgp: Decode BGP link-bandwidth extended community properly
X-Git-Url: https://git.tcpdump.org/tcpdump/commitdiff_plain/31c9c8736bf471385c41f532d96faf50a9ef62d1

bgp: Decode BGP link-bandwidth extended community properly

First two bytes are reserved for AS.

Before:
```
	  Extended Community (16), length: 8, Flags [OT]:
	    link-BW (0x4004), Flags [non-transitive]: bandwidth: -308754489798474897524123005616128.000 Mbps
	    0x0000:  4004 fde8 47f4 2400
	  Updated routes:
	    192.168.10.0/23
```

After:
```
	  Extended Community (16), length: 8, Flags [OT]:
	    link-BW (0x4004), Flags [non-transitive]: bandwidth: 1.000 Mbps
	    0x0000:  4004 fde8 47f4 2400
	  Updated routes:
	    192.168.10.0/23
```

Signed-off-by: Donatas Abraitis <donatas.abraitis@gmail.com>
---

diff --git a/print-bgp.c b/print-bgp.c
index 269055f5..4404b026 100644
--- a/print-bgp.c
+++ b/print-bgp.c
@@ -842,7 +842,7 @@ bgp_extended_community_print(netdissect_options *ndo,
             break;
 
     case BGP_EXT_COM_LINKBAND:
-            bw.i = GET_BE_U_4(pptr + 2);
+            bw.i = GET_BE_U_4(pptr + 4);
             ND_PRINT("bandwidth: %.3f Mbps",
                      bw.f*8/1000000);
             break;