hostapd源码分析

本实例中hostapd启动后，eloop监听了四个文件的可读性。

1. fd=3 /dev/random /* 监听 */

2. fd=4 socket(PF_INET, SOCK_DGRAM, 0) /* ioctl socket用于设置参数 */

3. fd=5 socket(PF_PACKET, SOCK_RAW, htons(ETH_P_EAPOL)) /* 监听EAPOL帧 */

4. fd=6 socket(PF_NETLINK, SOCK_RAW, NETLINK_ROUTE) /* 监听内核上报事件 */

5. fd=7 socket(PF_UNIX, SOCK_DGRAM, 0) /* 监听，hostapd_cli控制接口 */

【数据结构】

struct hostapd_iface

struct hapd_interfaces *interfaces

struct hostapd_config *conf /* 存放从配置文件获得的信息 */

struct hostapd_bss_config *bss

char iface[16+1] (=wlan0 ...)

macaddr bssid

struct wpa_driver_ops *driver (在hostapd_init中读取配置文件drvier时初始化，如wpa_driver_rtw_ops)

struct hostapd_data **bss /* 每个bss代表一个BSS，一个AP */

struct hostapd_iface *iface (=hostapd_iface)

struct hostapd_config *iconf (=hostapd_iface->conf)

struct hostapd_bss_config *conf (=hostapd_iface->conf->bss[i])

struct wpa_driver_ops *driver(=hostapd_iface->conf->driver)

void *drv_priv (=driver->hapd_init()=rtl871x_driver_init_ops())

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

【启动】

hostapd -B /var/hostapd/hostapd.conf -P /var/hostapd/hostapd.pid

main()

hostapd_global_init(&interfaces)

eap_server_register_methods()

eap_server_wsc_register()

eloop_init()

os_memset(&eloop, 0, sizeof(eloop))

dl_list_init(&eloop.timeout)

random_init()

eloop_register_read_sock() /* 注册监听文件 */

eloop_register_signal(SIGHUP, handle_reload, interfaces)

eloop_register_signal(SIGUSR1, handle_dump_state, interfaces)

eloop_register_signal_terminate(handle_term, interfaces)

hostapd_interface_init(&interfaces, configfile, debug)

/* 每一个interface对应一个配置文件，多个bss
1. 申请hostapd_iface内存
2. 设置hostapd_iface接口函数
3. 读取配置文件到hostapd_iface->conf

设置struct wpa_driver_ops

4. 申请hostapd_iface->bss[i]内存
5. 关联hostapd_iface->bss[i]到conf和conf->bss[i]

*/

iface = hostapd_init(configfile)

conf = hostapd_config_read(configfile)

hostapd_alloc_bss_data()

hapd = os_zalloc(sizeof(*hapd))

hapd->new_assoc_sta_cb = hostapd_new_assoc_sta /* 设置处理连接请求的callback函数 */

/*

*/

hostapd_driver_init(iface)

hapd->drv_priv = hapd->driver->hapd_init(hapd, ¶ms) /* 即drv_priv=rtl871x_driver_init_ops() */

rtl871x_driver_init_ops()

/* 创建ioctl socket，用来设置驱动参数 */

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

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

drv->l2_sock = l2_packet_init(drv->iface, NULL, ETH_P_EAPOL,rtl871x_handle_read, drv, 1)

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

eloop_register_read_sock()

rtl871x_wireless_event_init()

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

netlink_init()

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

eloop_register_read_sock()

hostapd_setup_interface(iface)

setup_interface(iface)

hostapd_set_country(hapd, country)

driver->set_country()

hostapd_get_hw_features(iface)

driver->get_hw_feature_data()

hostapd_setup_interface_complete(iface, 0)

hostapd_set_freq() => driver->set_freq()

hostapd_prepare_rates() => hostapd_set_rate_sets(...) => driver->set_rate_sets()

hostapd_set_rts() => driver->set_rts(hapd->drv_priv, rts) => rtl871x_set_rts_threshold()

hostapd_set_frag() => driver->set_frag() => rtl871x_set_frag_threshold()

hostapd_setup_bss()

hostapd_if_add() => driver->if_add()

hostapd_flush_old_stations()

hostapd_flush() => driver->flush() => rtl871x_sta_flush_ops()

hostapd_drv_sta_deauth()

hostapd_free_stas()

hostapd_set_privacy()

hostapd_broadcast_wep_clear()

hostapd_setup_encryption()

hostapd_get_ssid()

hostapd_setup_wpa_psk()

hostapd_derive_psk()

hostapd_init_wps()

ieee802_1x_init()

hapd->iface->ctrl_iface_init()

hostapd_ctrl_iface_init()

eloop_register_read_sock() /* 注册控制socket */

ieee802_11_set_beacon()

hostapd_drv_set_beacon()

hapd->driver->set_beacon() => rtl871x_set_beacon_ops()

rtl871x_hostapd_ioctl()

hostapd_tx_queue_params()

ap_list_init()

hostapd_driver_commit()

hostapd_global_run(&interfaces, ...)

eloop_run()

while(){

res = select(eloop.max_sock + 1, rfds, wfds, efds, timeout ? &_tv : NULL)

}

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

【处理连接请求】

监听到l2_sock的EAPOL数据之后，调用rtl871x_handle_read函数。

rtl871x_handle_read()

drv_event_eapol_rx(...)

wpa_supplicant_event(ctx, EVENT_EAPOL_RX, &event)

hostapd_event_eapol_rx()

ieee802_1x_receive()

sta->eapol_sm = ieee802_1x_alloc_eapol_sm(hapd, sta) /* 启动EAPOL状态机 */

switch (hdr->type) {

}

-------------------------hostapd.conf

##### hostapd configuration file ##############################################

interface=wlan0

ctrl_interface=/var/run/hostapd

wpa=2

##### Wi-Fi Protected Setup (WPS) #############################################

eap_server=1

wps_state=2

manufacturer=qmd

model_name=abc

model_number=123

serial_number=12345

device_type=6-0050F204-1

os_version=01020300

config_methods=label display push_button keypad

##### default configuration #######################################

driver=rtl871xdrv

beacon_int=100

ieee80211n=1

wme_enabled=1

uapsd_advertisement_enabled=0

ht_capab=[SHORT-GI-20][SHORT-GI-40]

wpa_key_mgmt=WPA-PSK

wpa_pairwise=CCMP

max_num_sta=32

wpa_group_rekey=86400

supported_rates=60 90 120 180 240 360 480 540

basic_rates=60 120 240

device_name=Lenovo B7D1

ssid=DIRECT-xyFEB7D1

uuid=109FA9FE-B7D1-0000-0000-000000000000

wpa_passphrase=12345678

channel=11

hw_mode=g

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