wpa_supplicant-0.8源码解析

启动命令：wpa_supplicant -Dwext -iwlan0 -c /var/wpa_supplicant/wpa_supplicant.conf

创建了四个socket：

1. src/drivers/driver_wext.c -> wpa_driver_wext_init() -> drv->ioctl_sock = socket(PF_INET, SOCK_DGRAM, 0)

    用于ioctl下发命令。

2. src/drivers/netlink.c -> netlink_init() -> netlink->sock = socket(PF_NETLINK, SOCK_RAW, NETLINK_ROUTE)

    用于驱动上传事件。

3. src/l2_packet/l2_packet_linux.c -> l2_packet_init() -> l2->fd = socket(PF_PACKET, l2_hdr ? SOCK_RAW : SOCK_DGRAM, htons(protocol))

    用于接受数据包，如EAP包。

4. ctrl_iface_unix.c -> wpa_supplicant_ctrl_iface_init() -> priv->sock = socket(PF_UNIX, SOCK_DGRAM, 0)

    用于wpa_cli控制。

【启动】

main()

global = wpa_supplicant_init(¶ms)

eap_register_methods()

eap_peer_wsc_register()  // 注册EAP-WSC方法

struct eap_method *eap

eap = eap_peer_method_alloc("WSC")

eap->init = eap_wsc_init

eap_wsc_init(struct eap_sm *sm) 完成EAP状态机的初始化

eap->deinit = eap_wsc_deinit

eap->process = eap_wsc_process

eap_wsc_process() 处理接收到的WSC包

eap_peer_method_register(eap)

eloop_init()

random_init()

wpa_supplicant_global_ctrl_iface_init(global)

wpas_notify_supplicant_initialized(global)

global->drv_priv[i] = wpa_drivers[i]->global_init()

for (i = 0; exitcode == 0 && i < iface_count; i++) 

wpa_supplicant_add_iface(global, &ifaces[i])

wpa_s = wpa_supplicant_alloc()

wpa_supplicant_init_iface(wpa_s, &t_iface)

wpa_s->conf = wpa_config_read(wpa_s->confname)  /* 读配置文件 */

wpa_config_read_network()  /* 解析network配置 */

wpa_config_process_global()  /* 解析全局变量配置 */

wpa_supplicant_set_driver(wpa_s, driver)   /* 设置diver接口函数 */

wpa_s->driver = wpa_drivers[i]

wpa_drv_init(wpa_s, wpa_s->ifname)

wpa_s->driver->init(wpa_s, ifname)

wpa_driver_wext_init()

 /* 创建ioctl socket，用来设置驱动参数 */

drv->ioctl_sock = socket(PF_INET, SOCK_DGRAM, 0)  

 /* 创建netlink socket，用来监听内核事件，并注册到eloop */

drv->netlink = netlink_init(cfg)  

netlink->sock = socket(PF_NETLINK, SOCK_RAW, NETLINK_ROUTE)

eloop_register_read_sock()

wpa_driver_wext_finish_drv_init()

linux_set_iface_flags(drv->ioctl_sock, drv->ifname, 1)

ioctl(sock,SIOCGIFFLAGS, &ifr)

ioctl(sock,SIOCSIFFLAGS, &ifr)

wpa_driver_wext_flush_pmkid(drv)

wpa_driver_wext_pmksa(drv, IW_PMKSA_FLUSH, NULL, NULL)

ioctl(drv->ioctl_sock,SIOCSIWPMKSA, &iwr)

wpa_driver_wext_set_mode(drv, 0)

ioctl(drv->ioctl_sock,SIOCSIWMODE, &iwr)

wpa_driver_wext_get_range(drv)

ioctl(drv->ioctl_sock,SIOCGIWRANGE, &iwr)

wpa_driver_wext_disconnect(drv)

ioctl(drv->ioctl_sock,SIOCGIWMODE, &iwr)

wpa_driver_wext_set_bssid(drv, null_bssid)

ioctl(drv->ioctl_sock,SIOCSIWAP, &iwr)

netlink_send_oper_ifla(drv->netlink, drv->ifindex, 1, IF_OPER_DORMANT)

ret = send(netlink->sock, &req, req.hdr.nlmsg_len, 0)

wpa_driver_wext_set_auth_param(drv, IW_AUTH_WPA_ENABLED, 1)

ioctl(drv->ioctl_sock,SIOCSIWAUTH, &iwr)

wpa_drv_set_param(wpa_s, wpa_s->conf->driver_param)

ifname = wpa_drv_get_ifname(wpa_s)

wpa_supplicant_init_wpa(wpa_s)

ctx = os_zalloc(sizeof(*ctx))

wpa_s->wpa = wpa_sm_init(ctx)  // 申请WPA SM内存

wpa_supplicant_driver_init(wpa_s)

/* 创建RAW socket，用来监听EAPOL帧，并注册到eloop，callback函数rtl871x_handle_read */

wpa_s->l2 = l2_packet_init(wpa_s->ifname, 

wpa_drv_get_mac_addr(wpa_s), 

ETH_P_EAPOL, 

wpa_supplicant_rx_eapol, 

wpa_s, 0)

l2->fd = socket(PF_PACKET, SOCK_RAW, htons(ETH_P_EAPOL))

ioctl(l2->fd,SIOCGIFINDEX, &ifr)

ioctl(l2->fd,SIOCGIFHWADDR, &ifr)

eloop_register_read_sock()

wpa_clear_keys(wpa_s, NULL)

wpa_drv_set_key(wpa_s, WPA_ALG_NONE, NULL, 0, 0, NULL, 0, NULL, 0)

wpa_s->driver->set_key() -> wpa_driver_wext_set_key()

wpa_driver_wext_set_key_ext()

ioctl(drv->ioctl_sock,SIOCSIWENCODEEXT, &iwr)

wpa_drv_set_key(wpa_s, WPA_ALG_NONE, NULL, 1, 0, NULL, 0, NULL, 0)

wpa_drv_set_key(wpa_s, WPA_ALG_NONE, NULL, 2, 0, NULL, 0, NULL, 0)

wpa_drv_set_key(wpa_s, WPA_ALG_NONE, NULL, 3, 0, NULL, 0, NULL, 0)

wpa_drv_set_key(wpa_s, WPA_ALG_NONE, NULL, 4, 0, NULL, 0, NULL, 0)

wpa_drv_set_countermeasures(wpa_s, 0)

wpa_s->driver->set_countermeasures() -> wpa_driver_wext_set_countermeasures()

wpa_driver_wext_set_auth_param()

ioctl(drv->ioctl_sock,SIOCSIWAUTH, &iwr)

wpa_drv_flush_pmkid(wpa_s) 

wpa_s->driver->flush_pmkid() -> wpa_driver_wext_flush_pmkid()

wpa_driver_wext_pmksa()

ioctl(drv->ioctl_sock,SIOCSIWPMKSA, &iwr)

wpa_supplicant_req_scan(wpa_s, interface_count, 100000)  // 发起SSID的扫描

eloop_is_timeout_registered(wpa_supplicant_scan, wpa_s, NULL)

eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL)

eloop_register_timeout(sec, usec, wpa_supplicant_scan, wpa_s, NULL)

/* 初始化WPS */

wpas_wps_init(wpa_s)

wps = os_zalloc(sizeof(*wps))

wps->cred_cb = wpa_supplicant_wps_cred  // cred_cb在EAP-WSC模块解析credential属性集时使用

wps->event_cb = wpa_supplicant_wps_event  // event_cb用于通知WSC模块发生的一些事件

wpas_wps_set_uuid(wpa_s, wps)

uuid_gen_mac_addr(wpa_s->own_addr, wps->uuid)

rcfg.pin_needed_cb = wpas_wps_pin_needed_cb

wps->registrar = wps_registrar_init(wps, &rcfg)

struct wps_registrar *reg = os_zalloc(sizeof(*reg))

reg->pin_needed_cb = cfg->pin_needed_cb

wps_set_ie(reg)

wpa_supplicant_init_eapol(wpa_s)

ctx = os_zalloc(sizeof(*ctx))

ctx->eapol_send = wpa_supplicant_eapol_send

ctx->port_cb = wpa_supplicant_port_cb

ctx->cb = wpa_supplicant_eapol_cb

wpa_s->eapol = eapol_sm_init(ctx)  // 申请EAPOL SM内存

sm = os_zalloc(sizeof(*sm))

sm->ctx = ctx

sm->eap = eap_peer_sm_init(sm, &eapol_cb, sm->ctx->msg_ctx, &conf)   // 申请EAP SM内存

sm = os_zalloc(sizeof(*sm))

eloop_register_timeout(1, 0, eapol_port_timers_tick, NULL, sm)

wpa_sm_set_eapol(wpa_s->wpa, wpa_s->eapol)

wpa_supplicant_ctrl_iface_init(wpa_s)

wpas_p2p_init(wpa_s->global, wpa_s)

wpa_bss_init(wpa_s)

wpas_notify_iface_added(wpa_s)

wpas_notify_network_added(wpa_s, ssid)

wpa_supplicant_run(global)

eloop_register_signal_terminate(wpa_supplicant_terminate, global)

eloop_register_signal_reconfig(wpa_supplicant_reconfig, global)

eloop_run()

WPS_PIN 36:13:E8:39:7C:32 12345670

------------------------------------------------------------------

wpa_supplicant_ctrl_iface_receive() // ctrl_iface_unix.c

    wpa_supplicant_ctrl_iface_process()  // ctrl_iface.c

        wpa_supplicant_ctrl_iface_wps_pin()

            wpas_wps_start_pin(wpa_s, _bssid, pin, 0, DEV_PW_DEFAULT)  // wps_supplicant.c

                ssid = wpas_wps_add_network(wpa_s, 0, bssid)

                    ssid = wpa_config_add_network(wpa_s->conf)

                wpas_wps_reassoc(wpa_s, ssid)

                    wpa_supplicant_req_scan(wpa_s, 0, 0)

// wpa_supplicant发起扫描

wpa_supplicant_req_scan()  // scan.c

    wpa_supplicant_scan()

        wps_build_probe_req_ie()

        wpa_supplicant_trigger_scan(wpa_s, ¶ms)

            wpa_drv_scan(wpa_s, params)

                wpa_s->driver->scan2()

                    wpa_driver_wext_scan()  // driver_wext.c

                        wpa_driver_wext_set_probe_req_ie(drv, params->extra_ies, params->extra_ies_len)

                            ioctl(drv->ioctl_sock, SIOCSIWPRIV, &iwr)

                        ioctl(drv->ioctl_sock, SIOCSIWSCAN, &iwr)

                        // Scan requested (ret=0) - scan timeout 5 seconds

                        eloop_register_timeout(5, 0, wpa_driver_wext_scan_timeout)

// driver ioctl SIOCSIWSCAN

rtw_wx_set_scan()

    rtw_sitesurvey_cmd(padapter, ssid, 1, NULL, 0)

// 接收scan结果

netlink_receive（）  // netlink.c

    netlink_receive_link(netlink, netlink->cfg->newlink_cb, h)

        wpa_driver_wext_event_rtm_newlink()  // driver_wext.c

            wpa_driver_wext_event_wireless()

               // SIOCGIWSCAN

                wpa_supplicant_event(drv->ctx, EVENT_SCAN_RESULTS, NULL)  // event.c

                    wpa_supplicant_event_scan_results()

                        _wpa_supplicant_event_scan_results()

                            scan_res = wpa_supplicant_get_scan_results()

                                scan_res = wpa_drv_get_scan_results2(wpa_s)

                                    wpa_s->driver->get_scan_results2(wpa_s->drv_priv)

                                        wpa_driver_wext_get_scan_results() // driver_wext.c

                                            res_buf = wpa_driver_wext_giwscan()

                                                ioctl(drv->ioctl_sock, SIOCGIWSCAN, &iwr)

                                                    rtw_wx_get_scan() // Kernel 8812au ioctl_linux.c

                                                        translate_scan()

                                                            iwe_stream_essid_proess()

                                                            iwe_stream_rate_proces()

                                                            iwe_stream_wpa_wpa2_process()

                                                            iwe_stream_wps_process()

                                                            ...

                            selected = wpa_supplicant_pick_network(wpa_s, scan_res, &ssid)

                                selected = wpa_supplicant_select_bss()

                                    *selected_ssid = wpa_scan_res_match()

                                        wpa_supplicant_ssid_bss_match()

                                            wpas_wps_ssid_bss_match()

                                                eap_is_wps_pin_enrollee()

                                                wps_is_addr_authorized()

                                                is_selected_pin_registrar()

                            wpa_supplicant_connect(wpa_s, selected, ssid)

                                wpa_supplicant_associate(wpa_s, selected, ssid)

// 开始连接

wpa_supplicant_associate（）

------------------------------------------------------------------



wpa_suplicant配置文件
------------------------------------------------------------------
ctrl_interface=/var/run/wpa_supplicant
update_config=1
uuid=109fa92f-1b8b-0000-0000-000000000000
device_name=1B8B
manufacturer=ABC
model_name=123
model_number=456
serial_number=12345
device_type=8-00101101-5
os_version=80000000
config_methods=virtual_display virtual_push_button keypad

network={
        ssid="DIRECT-ITDESKTOP-5VBHCUA3151"
        bssid=0e:8b:fd:e5:1b:50
        psk=b3e0502a0e27d0bbb4c1de0ac058aeb44914598e55ba7a795562f1ec783a7460
        proto=RSN
        key_mgmt=WPA-PSK
        auth_alg=OPEN
}
------------------------------------------



How to Compile WPA_SUPPLICANT wit Wi-Fi Direct Support on Ubuntu 12.04/13.04/13.10/14.04

What is WPA_SUPPLICANT ?
wpa_supplicant is a daemon for wireless connection management on Andorid/Linux OS. You can check your laptop running will be using wpa_supplicant in background.

ps -aef | grep wpa_supplicant


Download
mkdir -p ~/work; cd ~/work;
wget http://hostap.epitest.fi/releases/wpa_supplicant-2.1.tar.gz
tar  zxvf wpa_supplicant-2.1.tar.gz
cd wpa_supplicant-2.1/
cd wpa_supplicant/

Build Environment
Install compilations utilities such as gcc, make etc.

sudo apt-get update
sudo apt-get -y build-dep gcc-4.6 build-essential

P2P Configuration
cp defconfig .config
echo “” >> .config
echo “#Arun Kumar: Enabling Modules for Wi-Fi Direct aka P2P” >> .config
echo CONFIG_P2P=y >> .config
echo CONFIG_AP=y >> .config
echo CONFIG_WPS=y >> .config

Compilation & Installation
make

You may or may not get errors while compiling the source codes.I have faced following compilation errors and given corresponding solutions for the same as follows

Error#1
CC  ../src/drivers/driver_wired.c
../src/drivers/driver_nl80211.c:25:31: fatal error: netlink/genl/genl.h: No such file or directory
compilation terminated.
make: *** [../src/drivers/driver_nl80211.o] Error 1
Solution #1
sudo apt-get -y install libssl-dev libnl-3-dev
echo CFLAGS +=-I/usr/include/libnl3/ >> .config

make

Error#2
../src/drivers/driver_nl80211.c:95:9: warning: passing argument 1 of ‘genl_ctrl_alloc_cache’ from incompatible pointer type [enabled by default]
/usr/include/libnl3/netlink/genl/ctrl.h:25:14: note: expected ‘struct nl_sock *’ but argument is of type ‘struct nl_handle *’
../src/drivers/driver_nl80211.c:95:9: error: too few arguments to function ‘genl_ctrl_alloc_cache’
/usr/include/libnl3/netlink/genl/ctrl.h:25:14: note: declared here

Solution #2
sudo apt-get install libnl-genl-3-dev
echo CONFIG_LIBNL32=y >> .config

make

Now compilation succeeded.

wpa_supplicant is really compiled
tulashi@arunx:~/work/wpa_supplicant-2.1/wpa_supplicant$ file wpa_supplicant
wpa_supplicant: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), dynamically linked (uses shared libs), for GNU/Linux 2.6.24, BuildID[sha1]=0xd69c0b4bbafd67e19dfc86a66bfffdd10c2e2de8, not stripped