The following commit has been merged in the master branch: commit 6f77463027311b49d52bd3aef4d82c8aae27014f Author: Sven Eckelmann sven@narfation.org Date: Fri Feb 4 15:05:00 2011 +0100
batctl: add radiotap wifi packet decapsulation support
Signed-off-by: Sven Eckelmann sven@narfation.org
diff --git a/tcpdump.c b/tcpdump.c index 4443a2a..a715e27 100644 --- a/tcpdump.c +++ b/tcpdump.c @@ -460,6 +460,30 @@ static void parse_eth_hdr(unsigned char *packet_buff, ssize_t buff_len, int read } }
+static int monitor_header_length(unsigned char *packet_buff, ssize_t buff_len, int32_t hw_type) +{ + struct radiotap_header *radiotap_hdr; + switch (hw_type) { + case ARPHRD_IEEE80211_PRISM: + if (buff_len <= (ssize_t)PRISM_HEADER_LEN) + return -1; + else + return PRISM_HEADER_LEN; + + case ARPHRD_IEEE80211_RADIOTAP: + if (buff_len <= (ssize_t)RADIOTAP_HEADER_LEN) + return -1; + + radiotap_hdr = (struct radiotap_header*)packet_buff; + if (buff_len <= radiotap_hdr->it_len) + return -1; + else + return radiotap_hdr->it_len; + } + + return -1; +} + static void parse_wifi_hdr(unsigned char *packet_buff, ssize_t buff_len, int read_opt, int time_printed) { struct ether_header *eth_hdr; @@ -468,12 +492,6 @@ static void parse_wifi_hdr(unsigned char *packet_buff, ssize_t buff_len, int rea uint16_t fc; int hdr_len;
- if (buff_len <= (ssize_t)PRISM_HEADER_LEN) - return; - - buff_len -= PRISM_HEADER_LEN; - packet_buff += PRISM_HEADER_LEN; - /* we assume a minimum size of 38 bytes * (802.11 data frame + LLC) * before we calculate the real size */ @@ -540,6 +558,7 @@ int tcpdump(int argc, char **argv) int ret = EXIT_FAILURE, res, optchar, found_args = 1, max_sock = 0, tmp; int read_opt = USE_BAT_HOSTS; unsigned char packet_buff[2000]; + int monitor_header_len = -1;
while ((optchar = getopt(argc, argv, "hnp:")) != -1) { switch (optchar) { @@ -609,6 +628,7 @@ int tcpdump(int argc, char **argv) switch (dump_if->hw_type) { case ARPHRD_ETHER: case ARPHRD_IEEE80211_PRISM: + case ARPHRD_IEEE80211_RADIOTAP: break; default: printf("Error - interface '%s' is of unknown type: %i\n", dump_if->dev, dump_if->hw_type); @@ -685,7 +705,10 @@ int tcpdump(int argc, char **argv) parse_eth_hdr(packet_buff, read_len, read_opt, 0); break; case ARPHRD_IEEE80211_PRISM: - parse_wifi_hdr(packet_buff, read_len, read_opt, 0); + case ARPHRD_IEEE80211_RADIOTAP: + monitor_header_len = monitor_header_length(packet_buff, read_len, dump_if->hw_type); + if (monitor_header_len >= 0) + parse_wifi_hdr(packet_buff + monitor_header_len, read_len - monitor_header_len, read_opt, 0); break; default: /* should not happen */ diff --git a/tcpdump.h b/tcpdump.h index 17eaeb0..4364be1 100644 --- a/tcpdump.h +++ b/tcpdump.h @@ -27,6 +27,10 @@ #define ARPHRD_IEEE80211_PRISM 802 #endif
+#ifndef ARPHRD_IEEE80211_RADIOTAP +#define ARPHRD_IEEE80211_RADIOTAP 803 +#endif + #define DUMP_TYPE_BATOGM 1 #define DUMP_TYPE_BATICMP 2 #define DUMP_TYPE_BATUCAST 4 @@ -67,6 +71,13 @@ struct ieee80211_hdr { u_int8_t addr4[6]; } __attribute__ ((packed));
+struct radiotap_header { + u_int8_t it_version; + u_int8_t it_pad; + u_int16_t it_len; + u_int32_t it_present; +} __attribute__((__packed__)); + struct prism_item { u_int32_t did; u_int16_t status; @@ -91,5 +102,6 @@ struct prism_header { };
#define PRISM_HEADER_LEN sizeof(struct prism_header) +#define RADIOTAP_HEADER_LEN sizeof(struct radiotap_header)
int tcpdump(int argc, char **argv);