Q1-Add vendor IE

Topics in this section,

Learnings in this section

Version Info

Problem Statement

Approach and code flow

Actual change and Patch

Wireshark capture

Learnings in this section

In this section, you are going to learn

How to add vendor IE in Probe-Request and Association-Request similar to SSID IE

Version Info

#	Version
Ubuntu	Ubuntu 22.04 64 bit
Linux Kernel	6.9.2
Supplicant	wpa_supplicant 2.10

Problem Statement

Add vendor IE in Probe-Request and Association-Request similar to SSID IE

Approach and code flow

Call flow for add vendor ie in Probe-request

Call flow for add vendor ie in Association-Request

nl80211_global_init ()
   wpa_driver_nl80211_init_nl_global ()
      process_global_event ()
	 do_process_drv_event ()
	    send_scan_event ()
	       process_global_event ()
		  do_process_drv_event ()
		     mlme_event ()
			mlme_event_auth ()
			   wpa_supplicant_event ()
			       sme_event_auth ()
				  sme_associate ()
				      sta_construct_vendor_ie ()

Actual change and Patch

Download the below patch file

add_vendor_ie_prob_assoc_req.patch

See the full content of patch file

diff -crB original/wpa_supplicant-2.10/wpa_supplicant/scan.c changed/wpa_supplicant-2.10/wpa_supplicant/scan.c
*** original/wpa_supplicant-2.10/wpa_supplicant/scan.c	2022-01-17 02:21:29.000000000 +0530
--- changed/wpa_supplicant-2.10/wpa_supplicant/scan.c	2024-07-29 15:35:11.660281820 +0530
***************
*** 588,593 ****
--- 588,614 ----
  	wpabuf_free(default_ies);
  }
  
+ unsigned char vendor_ie[]= {
+ 	// Vender OUI ( Organization Unique identifier )
+ 	0x50, 0x6f, 0x9a,
+ 	// Vender-Specific data
+ 	0x33, 0x44, 0x55, 0x66
+ };
+ 
+ void sta_build_vendor_ie(struct wpa_supplicant *wpa_s, struct wpabuf **extra_ie)
+ {
+ 	size_t buf_len;
+ 	        /* Wi-Fi vendor element */
+         buf_len = 1 +   /* Element ID */
+                   1 +   /* Length */
+ 		  sizeof(vendor_ie);
+ 	if (wpabuf_resize(extra_ie, buf_len) == 0) {
+ 		wpabuf_put_u8(*extra_ie, WLAN_EID_VENDOR_SPECIFIC);
+ 		wpabuf_put_u8(*extra_ie, buf_len-2);
+ 		wpabuf_put_data(*extra_ie, vendor_ie, sizeof(vendor_ie));
+ 	}
+ 
+ }
  
  static struct wpabuf * wpa_supplicant_extra_ies(struct wpa_supplicant *wpa_s)
  {
***************
*** 674,681 ****
  
  		if (wpabuf_resize(&extra_ie, wpabuf_len(buf)) == 0)
  			wpabuf_put_buf(extra_ie, buf);
! 	}
! 
  	return extra_ie;
  }
  
--- 695,702 ----
  
  		if (wpabuf_resize(&extra_ie, wpabuf_len(buf)) == 0)
  			wpabuf_put_buf(extra_ie, buf);
! 	} 
! 		sta_build_vendor_ie(wpa_s, &extra_ie);
  	return extra_ie;
  }
  
diff -crB original/wpa_supplicant-2.10/wpa_supplicant/sme.c changed/wpa_supplicant-2.10/wpa_supplicant/sme.c
*** original/wpa_supplicant-2.10/wpa_supplicant/sme.c	2022-01-17 02:21:29.000000000 +0530
--- changed/wpa_supplicant-2.10/wpa_supplicant/sme.c	2024-07-29 15:36:17.476280799 +0530
***************
*** 1721,1726 ****
--- 1721,1741 ----
  }
  #endif /* CONFIG_IEEE80211R */
  
+ unsigned char vendor_assoc_ie[]= {
+         0xdd, // Element ID for
+       	0x07, // Length of the IE
+         // Vender OUI ( Organization Unique identifier )
+         0x50, 0x6f, 0x9a,
+         // Vender-Specific data
+         0x33, 0x44, 0x55, 0x66
+ };
+ 
+ void sta_construct_vendor_ie(struct wpa_supplicant *wpa_s)
+ {
+ 	os_memcpy(wpa_s->sme.assoc_req_ie + wpa_s->sme.assoc_req_ie_len,vendor_assoc_ie,sizeof(vendor_assoc_ie));
+ 	wpa_s->sme.assoc_req_ie_len += sizeof(vendor_assoc_ie);
+ 
+ }
  
  void sme_associate(struct wpa_supplicant *wpa_s, enum wpas_mode mode,
  		   const u8 *bssid, u16 auth_type)
***************
*** 1957,1963 ****
  		}
  		wpa_s->sme.assoc_req_ie_len += multi_ap_ie_len;
  	}
! 
  	params.bssid = bssid;
  	params.ssid = wpa_s->sme.ssid;
  	params.ssid_len = wpa_s->sme.ssid_len;
--- 1972,1978 ----
  		}
  		wpa_s->sme.assoc_req_ie_len += multi_ap_ie_len;
  	}
! 	sta_construct_vendor_ie(wpa_s);
  	params.bssid = bssid;
  	params.ssid = wpa_s->sme.ssid;
  	params.ssid_len = wpa_s->sme.ssid_len;

test:~$ pwd
/home/test

Make sure internet is available in laptop to download supplicant package

test:~$ sudo wget https://w1.fi/releases/wpa_supplicant-2.10.tar.gz

Create a directory

test:~$ mkdir supplicant

Change directory to supplicant

test:~$ cd supplicant

Note : Your present working directory should be supplicant

test:~$ pwd
/home/test/supplicant/

Extract wpa_supplicant

test:~$ sudo tar -xvf ~/wpa_supplicant-2.10.tar.gz

Run the below command to apply patch

test:~$ patch -p1 < add_vendor_ie_prob_assoc_req.patch
patching file wpa_supplicant-2.10/wpa_supplicant/scan.c
patching file wpa_supplicant-2.10/wpa_supplicant/sme.c

Change directory to wpa_supplicant

test:~$ cd wpa_supplicant-2.10/wpa_supplicant/

Check the current working directory using pwd command
Make sure your current working directory is wpa_supplicant

test:~$ pwd
/home/test/supplicant/wpa_supplicant-2.10/wpa_supplicant

Copy the contents of defconfig file to .config file

test:~$ sudo cp defconfig .config

Compile wpa_supplicant

test:~$ sudo make

Create run_supplicant.conf

test:~$ sudo vim ./run_supplicant.conf

ctrl_interface=/run/wpa_supplicant
update_config=1

network={
ssid="test_open"
key_mgmt=NONE
}

Run wpa_supplicant

test:~$ sudo ./wpa_supplicant -Dnl80211 -i wlan1 -c ./run_supplicant.conf

Wireshark capture

Download file to check wireshark output

add_vendor_ie_prob_assoc_req.pcapng

Check for probe request packet
Click on packet No.97 as shown in the image below

Click on IEEE 802.11 Wireless Management
Click on Tagged parameters
Click on Tag: Vendor Specific: Wi-Fi Alliance: Unknown

Check for association request packet
Click on packet No.135 as shown in the image below

Click on IEEE 802.11 Wireless Management
Click on Tagged parameters
Click on Tag: Vendor Specific: Wi-Fi Alliance: Unknown