Handle frames with an FCS (at least with a radiotap header).

Handle (to some degree) 802.11n Control Wrapper, Block Ack Req, and
Block Ack frames.

diff --git a/ieee802_11.h b/ieee802_11.h
index 3bcda7d22ba1bdb89090c54e079e17d74da0e006..b921c8f8042d9a80e039006e11e45c837a7f9f6c 100644 (file)
--- a/ieee802_11.h
+++ b/ieee802_11.h
@@ -72,12 +72,15 @@
 /* RESERVED                    0xF  */
 
 
-#define        CTRL_PS_POLL    0xA
-#define        CTRL_RTS        0xB
-#define        CTRL_CTS        0xC
-#define        CTRL_ACK        0xD
-#define        CTRL_CF_END     0xE
-#define        CTRL_END_ACK    0xF
+#define CTRL_CONTROL_WRAPPER   0x7
+#define CTRL_BLOCK_ACK_REQ     0x8
+#define CTRL_BLOCK_ACK         0x9
+#define        CTRL_PS_POLL            0xA
+#define        CTRL_RTS                0xB
+#define        CTRL_CTS                0xC
+#define        CTRL_ACK                0xD
+#define        CTRL_CF_END             0xE
+#define        CTRL_END_ACK            0xF
 
 #define        DATA_DATA                       0x0
 #define        DATA_DATA_CF_ACK                0x1
@@ -312,6 +315,28 @@ struct ctrl_end_ack_t {
 #define        CTRL_END_ACK_HDRLEN     (IEEE802_11_FC_LEN+IEEE802_11_DUR_LEN+\
                                 IEEE802_11_RA_LEN+IEEE802_11_BSSID_LEN)
 
+struct ctrl_block_ack_req_t {
+       u_int16_t       fc;
+       u_int16_t       duration;
+       u_int8_t        ra[6];
+       u_int8_t        ta[6];
+       u_int16_t       bar_control;
+};
+
+#define        CTRL_BLOCK_ACK_REQ_HDRLEN       (IEEE802_11_FC_LEN+IEEE802_11_DUR_LEN+\
+                                        IEEE802_11_RA_LEN+IEEE802_11_TA_LEN)
+
+struct ctrl_block_ack_t {
+       u_int16_t       fc;
+       u_int16_t       duration;
+       u_int8_t        ra[6];
+       u_int8_t        ta[6];
+       u_int16_t       ba_control;
+};
+
+#define        CTRL_BLOCK_ACK_HDRLEN   (IEEE802_11_FC_LEN+IEEE802_11_DUR_LEN+\
+                                IEEE802_11_RA_LEN+IEEE802_11_TA_LEN)
+
 #define        IV_IV(iv)       ((iv) & 0xFFFFFF)
 #define        IV_PAD(iv)      (((iv) >> 24) & 0x3F)
 #define        IV_KEYID(iv)    (((iv) >> 30) & 0x03)

diff --git a/print-802_11.c b/print-802_11.c
index 8cab17c0e5519a31c99bd4cf57455f095b10cd76..28f1bbe7a326d18854a8c79e19aa2be9e48b1811 100644 (file)
--- a/print-802_11.c
+++ b/print-802_11.c
@@ -616,6 +616,26 @@ static int
 ctrl_body_print(u_int16_t fc, const u_char *p)
 {
        switch (FC_SUBTYPE(fc)) {
+       case CTRL_CONTROL_WRAPPER:
+               printf("Control Wrapper");
+               /* XXX - requires special handling */
+               break;
+       case CTRL_BLOCK_ACK_REQ:
+               printf("Block Ack Request");
+               if (!TTEST2(*p, CTRL_BLOCK_ACK_REQ_HDRLEN))
+                       return 0;
+               if (!eflag)
+                       printf(" RA:%s ",
+                           etheraddr_string(((const struct ctrl_block_ack_req_t *)p)->ra));
+               break;
+       case CTRL_BLOCK_ACK:
+               printf("Block Ack");
+               if (!TTEST2(*p, CTRL_BLOCK_ACK_HDRLEN))
+                       return 0;
+               if (!eflag)
+                       printf(" RA:%s ",
+                           etheraddr_string(((const struct ctrl_block_ack_t *)p)->ra));
+               break;
        case CTRL_PS_POLL:
                printf("Power Save-Poll");
                if (!TTEST2(*p, CTRL_PS_POLL_HDRLEN))
@@ -911,17 +931,32 @@ ieee_802_11_hdr_print(u_int16_t fc, const u_char *p, const u_int8_t **srcp,
 #endif
 
 static u_int
-ieee802_11_print(const u_char *p, u_int length, u_int caplen, int pad)
+ieee802_11_print(const u_char *p, u_int length, u_int orig_caplen, int pad,
+    int fcslen)
 {
        u_int16_t fc;
-       u_int hdrlen;
+       u_int caplen, hdrlen;
        const u_int8_t *src, *dst;
        u_short extracted_ethertype;
 
-       if (caplen < IEEE802_11_FC_LEN) {
+       caplen = orig_caplen;
+       /* Remove FCS, if present */
+       if (length < fcslen) {
                printf("[|802.11]");
                return caplen;
        }
+       length -= fcslen;
+       if (caplen > length) {
+               /* Amount of FCS in actual packet data, if any */
+               fcslen = caplen - length;
+               caplen -= fcslen;
+               snapend -= fcslen;
+       }
+
+       if (caplen < IEEE802_11_FC_LEN) {
+               printf("[|802.11]");
+               return orig_caplen;
+       }
 
        fc = EXTRACT_LE_16BITS(p);
        hdrlen = extract_header_length(fc);
@@ -999,11 +1034,11 @@ ieee802_11_print(const u_char *p, u_int length, u_int caplen, int pad)
 u_int
 ieee802_11_if_print(const struct pcap_pkthdr *h, const u_char *p)
 {
-       return ieee802_11_print(p, h->len, h->caplen, 0);
+       return ieee802_11_print(p, h->len, h->caplen, 0, 0);
 }
 
 static int
-print_radiotap_field(struct cpack_state *s, u_int32_t bit, int *pad)
+print_radiotap_field(struct cpack_state *s, u_int32_t bit, u_int8_t *flags)
 {
        union {
                int8_t          i8;
@@ -1018,8 +1053,7 @@ print_radiotap_field(struct cpack_state *s, u_int32_t bit, int *pad)
        switch (bit) {
        case IEEE80211_RADIOTAP_FLAGS:
                rc = cpack_uint8(s, &u.u8);
-               if (u.u8 & IEEE80211_RADIOTAP_F_DATAPAD)
-                       *pad = 1;
+               *flags = u.u8;
                break;
        case IEEE80211_RADIOTAP_RATE:
        case IEEE80211_RADIOTAP_DB_ANTSIGNAL:
@@ -1143,7 +1177,8 @@ 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;
+       u_int8_t flags;
+       int pad, fcslen;
 
        if (caplen < sizeof(*hdr)) {
                printf("[|802.11]");
@@ -1177,8 +1212,12 @@ ieee802_11_radio_print(const u_char *p, u_int length, u_int caplen)
                return caplen;
        }
 
+       /* Assume no flags */
+       flags = 0;
        /* Assume no Atheros padding between 802.11 header and body */
        pad = 0;
+       /* Assume no FCS at end of frame */
+       fcslen = 0;
        for (bit0 = 0, presentp = &hdr->it_present; presentp <= last_presentp;
             presentp++, bit0 += 32) {
                for (present = EXTRACT_LE_32BITS(presentp); present;
@@ -1190,12 +1229,18 @@ 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, &pad) != 0)
+                       if (print_radiotap_field(&cpacker, bit, &flags) != 0)
                                goto out;
                }
        }
+
+       if (flags & IEEE80211_RADIOTAP_F_DATAPAD)
+               pad = 1;        /* Atheros padding */
+       if (flags & IEEE80211_RADIOTAP_F_FCS)
+               fcslen = 4;     /* FCS at end of packet */
 out:
-       return len + ieee802_11_print(p + len, length - len, caplen - len, pad);
+       return len + ieee802_11_print(p + len, length - len, caplen - len, pad,
+           fcslen);
 #undef BITNO_32
 #undef BITNO_16
 #undef BITNO_8
@@ -1231,7 +1276,7 @@ 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, 0);
+           length - caphdr_len, caplen - caphdr_len, 0, 0);
 }
 
 #define PRISM_HDR_LEN          144
@@ -1276,7 +1321,7 @@ 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, 0);
+           length - PRISM_HDR_LEN, caplen - PRISM_HDR_LEN, 0, 0);
 }
 
 /*