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)

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

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

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

通过ioctl设置驱动参数：

【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()

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