tcpdump: print 802.11 sequence numbers properly

[Stefan Sperling]

tcpdump -e -v -y IEEE802_11_RADIO currently prints sequence number
and fragment number as a combined decimal value.

This patch makes tcpdump display these values separately which is a lot
easier to follow along as packets scroll by.

ok?

diff 18a81a05d6e3098eadc4b5e23d6656377f87591a /usr/src
blob - 7528f50e45765f83d5d719d831df2880838bc28c
file + usr.sbin/tcpdump/print-802_11.c
--- usr.sbin/tcpdump/print-802_11.c
+++ usr.sbin/tcpdump/print-802_11.c
@@ -162,7 +162,9 @@ ieee80211_hdr(struct ieee80211_frame *wh)
                u_int16_t seq;
                TCARR(wh->i_seq);
                bcopy(wh->i_seq, &seq, sizeof(u_int16_t));
-               printf(" (seq %u): ", letoh16(seq));
+               printf(" (seq %u frag %u): ",
+                   letoh16(seq) >> IEEE80211_SEQ_SEQ_SHIFT,
+                   letoh16(seq) & IEEE80211_SEQ_FRAG_MASK);
        } else
                printf(": ");