According to the section "Alignment in Radiotap" on the radiotap website, the radiotap header fields must be padded. 8-bit fields must be 8-bit aligned, 16-bit must be 16-bit aligned, etc. In the current implementation, libwifi_create_radiotap with RATE, CHANNEL, and DBM_TX_POWER fields will be generated incorrectly, due to misalignment from the RATE field. This PR adds the appropriate padding.

I am not sure of what I am seeing here, but it seems to me that, I don't know why, beacon frame with an Auth key Suites of 802.1X_FT (3) ends up being shown as 802.1X.

I found this because of my tests, but using the examples/parse_beacon/parse_beacon.c on the same .pcap file gives the same problem:

 $ ./parse_beacon/parse_beacon --file beacons.pcap
[...]
ESSID: DEMOWIFI
BSSID: 22:18:0a:6f:5a:ea
Receiver: ff:ff:ff:ff:ff:ff
Transmitter: 22:18:0a:6f:5a:ea
Channel: 11
WPS: No
Encryption: WPA2, WPA
	Group Ciphers: TKIP
	Pairwise Ciphers: TKIP, CCMP128
	Auth Key Suites: 802.1X
Tagged Parameters:
[...]

Shouldn't there be a 802.1X_FT in Auth Key Suites line ?

beacons.pcap.gz

The documentation states that you should be able to cd into the various example directories and run make in their readmes but there are no Makefiles in them.

This PR adds support for 6GHz by looking at the Radiotap header of a supplied frame.

From commit 7c2b373b:

Radiotap information is now stored in the libwifi_frame struct, and will be kept automatically in libwifi_frame.radiotap_info for the lifecycle of said frame, if it is present.

A new flag has been added for the frame for use with libwifi_frame.flags to detect if the radiotap info is present: LIBWIFI_FLAGS_RADIOTAP_PRESENT.

The frame parser will now automatically calculate the band and center channel from radiotap data, and will store them in libwifi_radiotap_info.channel.center and libwifi_radiotap_info.channel.band.

Four new flags have been added for use with the new radiotap band field:

• LIBWIFI_RADIOTAP_BAND_2GHZ
• LIBWIFI_RADIOTAP_BAND_5GHZ
• LIBWIFI_RADIOTAP_BAND_6GHZ
• LIBWIFI_RADIOTAP_BAND_900MHZ

These can be used with a binary AND: if (rtap.channel.band & LIBWIFI_RADIOTAP_BAND_6GHZ) { }

This PR adds

• A bug fix for parsing tagged parameters with a length of zero
• A function to check if a tagged parameter is present via tag number (libwifi_check_tag(...))
• A function to get the tagged parameter name via a tag number (libwifi_get_tag_name(...))

This commit also enforces error code checking on functions inside of the generation functions, such as for libwifi_quick_add_tag.

• [X] Generation Tests
• [ ] Parser Tests
• [ ] Update comment doc for new generation function returns

In a very specific build setup (using meson+ninja and gcc only), on armv6l, I came across that build error:

[112/132] Compiling C object subprojects/libwifi-0.0.6/examples/parse_eapol.p/parse_eapol_parse_eapol.c.o
FAILED: subprojects/libwifi-0.0.6/examples/parse_eapol.p/parse_eapol_parse_eapol.c.o 
cc -Isubprojects/libwifi-0.0.6/examples/parse_eapol.p -Isubprojects/libwifi-0.0.6/examples -I../subprojects/libwifi-0.0.6/examples -I../subprojects/libwifi-0.0.6/src -I/usr/local/include -fdiagnostics-color=always -pipe -D_FILE_OFFSET_BITS=64 -Wall -Winvalid-pch -g -Wall -Werror -O3 -MD -MQ subprojects/libwifi-0.0.6/examples/parse_eapol.p/parse_eapol_parse_eapol.c.o -MF subprojects/libwifi-0.0.6/examples/parse_eapol.p/parse_eapol_parse_eapol.c.o.d -o subprojects/libwifi-0.0.6/examples/parse_eapol.p/parse_eapol_parse_eapol.c.o -c ../subprojects/libwifi-0.0.6/examples/parse_eapol/parse_eapol.c
../subprojects/libwifi-0.0.6/examples/parse_eapol/parse_eapol.c: In function ‘handle_pkt’:
../subprojects/libwifi-0.0.6/examples/parse_eapol/parse_eapol.c:41:56: error: format ‘%lu’ expects argument of type ‘long unsigned int’, but argument 2 has type ‘uint64_t’ {aka ‘long long unsigned int’} [-Werror=format=]
   41 |             printf("EAPOL: Key Info: Replay Counter: %lu\n", data.key_info.replay_counter);
      |                                                      ~~^     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      |                                                        |                  |
      |                                                        long unsigned int  uint64_t {aka long long unsigned int}
      |                                                      %llu
cc1: all warnings being treated as errors
[113/132] Compiling C object subprojects/libwifi-0.0.6/utils/test_misc.p/src_helpers.c.o
ninja: build stopped: subcommand failed.

This is easly fixed with that patch:

diff --git a/examples/parse_eapol/parse_eapol.c b/examples/parse_eapol/parse_eapol.c
index cf35a6f..f36685b 100644
--- a/examples/parse_eapol/parse_eapol.c
+++ b/examples/parse_eapol/parse_eapol.c
@@ -38,7 +38,7 @@ void handle_pkt(unsigned char *args, const struct pcap_pkthdr *header, const uns
             printf("EAPOL: Descriptor: %d\n", data.descriptor);
             printf("EAPOL: Key Info: Information: 0x%04x\n", data.key_info.information);
             printf("EAPOL: Key Info: Key Length: %d\n", data.key_info.key_length);
-            printf("EAPOL: Key Info: Replay Counter: %lu\n", data.key_info.replay_counter);
+            printf("EAPOL: Key Info: Replay Counter: %"PRIu64"\n", data.key_info.replay_counter);
             printf("EAPOL: Key Info: Nonce: ");
             for (size_t i = 0; i < sizeof(data.key_info.nonce); ++i) {
                 printf("%02x ", data.key_info.nonce[i]);
diff --git a/utils/src/test_parsing.c b/utils/src/test_parsing.c
index b9f9dbc..84a1bde 100644
--- a/utils/src/test_parsing.c
+++ b/utils/src/test_parsing.c
@@ -370,7 +370,7 @@ void parse_data_eapol(struct libwifi_frame frame, unsigned char *args, const str
             printf("EAPOL: Descriptor: %d\n", data.descriptor);
             printf("EAPOL: Key Info: Information: 0x%04x\n", data.key_info.information);
             printf("EAPOL: Key Info: Key Length: %d\n", data.key_info.key_length);
-            printf("EAPOL: Key Info: Replay Counter: %llu\n", data.key_info.replay_counter);
+            printf("EAPOL: Key Info: Replay Counter: %"PRIu64"\n", data.key_info.replay_counter);
             printf("EAPOL: Key Info: Nonce: ");
             for (size_t i = 0; i < sizeof(data.key_info.nonce); ++i) printf("%02x ", data.key_info.nonce[i]);

The second snippet avoids a warning