Handle the padding that Atheros adapters helpfully introduce between the

802.2 header and the body.

diff --git a/print-802_11.c b/print-802_11.c
index 0f6f5d3318df161cb77b05cff57721fd807c727b..70124a7062da1c4e5af0b8c35d2525d52eeed83b 100644 (file)
--- a/print-802_11.c
+++ b/print-802_11.c
@@ -22,7 +22,7 @@
 
 #ifndef lint
 static const char rcsid[] _U_ =
-    "@(#) $Header: /tcpdump/master/tcpdump/print-802_11.c,v 1.31.2.14 2007-07-22 22:01:05 guy Exp $ (LBL)";
+    "@(#) $Header: /tcpdump/master/tcpdump/print-802_11.c,v 1.31.2.15 2007-07-22 23:14:14 guy Exp $ (LBL)";
 #endif
 
 #ifdef HAVE_CONFIG_H
@@ -906,8 +906,12 @@ ieee_802_11_hdr_print(u_int16_t fc, const u_char *p, const u_int8_t **srcp,
        }
 }
 
+#ifndef roundup2
+#define        roundup2(x, y)  (((x)+((y)-1))&(~((y)-1))) /* if y is powers of two */
+#endif
+
 static u_int
-ieee802_11_print(const u_char *p, u_int length, u_int caplen)
+ieee802_11_print(const u_char *p, u_int length, u_int caplen, int pad)
 {
        u_int16_t fc;
        u_int hdrlen;
@@ -921,6 +925,8 @@ ieee802_11_print(const u_char *p, u_int length, u_int caplen)
 
        fc = EXTRACT_LE_16BITS(p);
        hdrlen = extract_header_length(fc);
+       if (pad)
+               hdrlen = roundup2(hdrlen, 4);
 
        if (caplen < hdrlen) {
                printf("[|802.11]");
@@ -993,11 +999,11 @@ ieee802_11_print(const u_char *p, u_int length, u_int caplen)
 u_int
 ieee802_11_if_print(const struct pcap_pkthdr *h, const u_char *p)
 {
-       return ieee802_11_print(p, h->len, h->caplen);
+       return ieee802_11_print(p, h->len, h->caplen, 0);
 }
 
 static int
-print_radiotap_field(struct cpack_state *s, u_int32_t bit)
+print_radiotap_field(struct cpack_state *s, u_int32_t bit, int *pad)
 {
        union {
                int8_t          i8;
@@ -1011,6 +1017,10 @@ print_radiotap_field(struct cpack_state *s, u_int32_t bit)
 
        switch (bit) {
        case IEEE80211_RADIOTAP_FLAGS:
+               rc = cpack_uint8(s, &u.u8);
+               if (u.u8 & IEEE80211_RADIOTAP_F_DATAPAD)
+                       *pad = 1;
+               break;
        case IEEE80211_RADIOTAP_RATE:
        case IEEE80211_RADIOTAP_DB_ANTSIGNAL:
        case IEEE80211_RADIOTAP_DB_ANTNOISE:
@@ -1133,6 +1143,7 @@ ieee802_11_radio_print(const u_char *p, u_int length, u_int caplen)
        int bit0;
        const u_char *iter;
        u_int len;
+       int pad;
 
        if (caplen < sizeof(*hdr)) {
                printf("[|802.11]");
@@ -1166,6 +1177,8 @@ ieee802_11_radio_print(const u_char *p, u_int length, u_int caplen)
                return caplen;
        }
 
+       /* Assume no Atheros padding between 802.11 header and body */
+       pad = 0;
        for (bit0 = 0, presentp = &hdr->it_present; presentp <= last_presentp;
             presentp++, bit0 += 32) {
                for (present = EXTRACT_LE_32BITS(presentp); present;
@@ -1177,12 +1190,12 @@ ieee802_11_radio_print(const u_char *p, u_int length, u_int caplen)
                        bit = (enum ieee80211_radiotap_type)
                            (bit0 + BITNO_32(present ^ next_present));
 
-                       if (print_radiotap_field(&cpacker, bit) != 0)
+                       if (print_radiotap_field(&cpacker, bit, &pad) != 0)
                                goto out;
                }
        }
 out:
-       return len + ieee802_11_print(p + len, length - len, caplen - len);
+       return len + ieee802_11_print(p + len, length - len, caplen - len, pad);
 #undef BITNO_32
 #undef BITNO_16
 #undef BITNO_8
@@ -1213,7 +1226,7 @@ ieee802_11_avs_radio_print(const u_char *p, u_int length, u_int caplen)
        }
 
        return caphdr_len + ieee802_11_print(p + caphdr_len,
-           length - caphdr_len, caplen - caphdr_len);
+           length - caphdr_len, caplen - caphdr_len, 0);
 }
 
 #define PRISM_HDR_LEN          144
@@ -1252,7 +1265,7 @@ prism_if_print(const struct pcap_pkthdr *h, const u_char *p)
        }
 
        return PRISM_HDR_LEN + ieee802_11_print(p + PRISM_HDR_LEN,
-           length - PRISM_HDR_LEN, caplen - PRISM_HDR_LEN);
+           length - PRISM_HDR_LEN, caplen - PRISM_HDR_LEN, 0);
 }
 
 /*