http://blog.csdn.net/cuijiyue/article/details/51428835

1 配置文件

conf文件作为wpa_supplicant的配置文件，一般叫做 wpa_supplicant.conf 。其中存储着wpa_supplicant的运行参数和以保存的网络列表。 conf文件的路径，通过启动wpa_supplicant时的 –c 参数传入，初始化过程中赋值到wpa_s->confname，然后将数据读入wpa_s->conf中。

wpa_supplicant的所有参数都定义在struct wpa_config中

struct wpa_config { //config文件中，存储所有network节点的链表 struct wpa_ssid *ssid; //按照priority排列的network节点 struct wpa_ssid **pssid; //*pssid的长度 int num_prio; /** * cred - Head of the credential list * * This is the head for the list of all the configured credentials. */ struct wpa_cred *cred; //EAP版本，WPAS支持到2 int eapol_version; //1---wpas负责扫描和选择网络 //0、2---驱动负责扫描和连接 int ap_scan; //bgscan - Background scan and roaming parameters or %NULL if none char *bgscan; //disable_scan_offload - Disable automatic offloading of scan requests //驱动可以自行sche_scan，设置为1，disable驱动的功能 int disable_scan_offload; // ctrl_interface - Parameters for the control interface //结构名称例如wlan0 char *ctrl_interface; //ctrl_interface_group - Control interface group (DEPRECATED) char *ctrl_interface_group; //fast_reauth - EAP fast re-authentication (session resumption) //默认是1 disable，设置为0 disable该功能， int fast_reauth; //opensc_engine_path - Path to the OpenSSL engine for opensc char *opensc_engine_path; //pkcs11_engine_path - Path to the OpenSSL engine for PKCS#11 char *pkcs11_engine_path; //pkcs11_module_path - Path to the OpenSSL OpenSC/PKCS#11 module char *pkcs11_module_path; //pcsc_reader - PC/SC reader name prefix char *pcsc_reader; // pcsc_pin - PIN for USIM, GSM SIM, and smartcards char *pcsc_pin; //external_sim - Use external processing for SIM/USIM operations int external_sim; //driver_param - Driver interface parameters //如果有的话，通过struct wpa_driver_ops::set_param()执行 char *driver_param; //dot11RSNAConfigPMKLifetime - Maximum lifetime of a PMK unsigned int dot11RSNAConfigPMKLifetime; // dot11RSNAConfigPMKReauthThreshold - PMK re-authentication threshold unsigned int dot11RSNAConfigPMKReauthThreshold; //dot11RSNAConfigSATimeout - Security association timeout unsigned int dot11RSNAConfigSATimeout; //update_config - Is wpa_supplicant allowed to update configuration/ int update_config; //blobs - Configuration blobs struct wpa_config_blob *blobs; // uuid - Universally Unique IDentifier (UUID; see RFC 4122) for WPS u8 uuid[16]; //device_name - Device Name (WPS) char *device_name; //manufacturer - Manufacturer (WPS) //The manufacturer of the device (up to 64 ASCII characters) char *manufacturer; // model_name - Model Name (WPS) //Model of the device (up to 32 ASCII characters) char *model_name; //model_number - Model Number (WPS) //Additional device description (up to 32 ASCII characters) char *model_number; //serial_number - Serial Number (WPS) //Serial number of the device (up to 32 characters) char *serial_number; //device_type - Primary Device Type (WPS) u8 device_type[WPS_DEV_TYPE_LEN]; //config_methods - Config Methods（WPS） char *config_methods; //os_version - OS Version (WPS) //4-octet operating system version number u8 os_version[4]; //country - Country code（ISO/IEC alpha2） char country[2]; /** * wps_cred_processing - Credential processing * * 0 = process received credentials internally * 1 = do not process received credentials; just pass them over * ctrl_iface to external program(s) * 2 = process received credentials internally and pass them over * ctrl_iface to external program(s) */ int wps_cred_processing; #define MAX_SEC_DEVICE_TYPES 5 /** * sec_device_types - Secondary Device Types (P2P) */ u8 sec_device_type[MAX_SEC_DEVICE_TYPES][WPS_DEV_TYPE_LEN]; int num_sec_device_types; int p2p_listen_reg_class; int p2p_listen_channel; int p2p_oper_reg_class; int p2p_oper_channel; int p2p_go_intent; char *p2p_ssid_postfix; int persistent_reconnect; int p2p_intra_bss; unsigned int num_p2p_pref_chan; struct p2p_channel *p2p_pref_chan; struct wpa_freq_range_list p2p_no_go_freq; int p2p_add_cli_chan; int p2p_ignore_shared_freq; int p2p_optimize_listen_chan; struct wpabuf *wps_vendor_ext_m1; //wps_vendor_ext - Vendor extension attributes in WPS //MAX_WPS_VENDOR_EXT = 10 struct wpabuf *wps_vendor_ext[MAX_WPS_VENDOR_EXT]; // p2p_group_idle - Maximum idle time in seconds for P2P group //超过该时间（秒），将关闭数据 int p2p_group_idle; //p2p_passphrase_len - Passphrase length (8..63) for P2P GO //GO产生的随机秘钥的长度（8~63） unsigned int p2p_passphrase_len; //bss_max_count - Maximum number of BSS entries to keep in memory //存储的bss最大个数 unsigned int bss_max_count; //bss_expiration_age - BSS entry age after which it can be expired //bss超期时间秒（bss 被remnove后的时间）， unsigned int bss_expiration_age; //bss_expiration_scan_count - Expire BSS after number of scans //bss经过几次扫描不到，被remove unsigned int bss_expiration_scan_count; //filter_ssids - SSID-based scan result filtering //0--disable， 1--enable int filter_ssids; //filter_rssi - RSSI-based scan result filtering //0--disable, -n--去掉scan_res中<-ndb的bss int filter_rssi; //max_num_sta - Maximum number of STAs in an AP/P2P GO unsigned int max_num_sta; // freq_list - Array of allowed scan frequencies or %NULL for all //允许扫描的频率列表 int *freq_list; //scan_cur_freq - Whether to scan only the current channel,只扫描当前频率 int scan_cur_freq; //changed_parameters - Bitmap of changed parameters since last update unsigned int changed_parameters; //disassoc_low_ack - Disassocicate stations with massive packet loss //因丢包导致关联失败的station个数 int disassoc_low_ack; //interworking - Whether Interworking (IEEE 802.11u) is enabled int interworking; //access_network_type - Access Network Type //interworking=1时，该项起作用，取值0~15 int access_network_type; //hessid - Homogenous ESS identifier 80211u相关 u8 hessid[ETH_ALEN]; //hs20 - Hotspot 2.0 int hs20; //pbc_in_m1 - AP mode WPS probing workaround for PBC with Windows 7 int pbc_in_m1; //autoscan - Automatic scan parameters or %NULL if none，文档中有介绍 //<autoscan module name>:<module parameters> char *autoscan; //NFC相关 int wps_nfc_pw_from_config; int wps_nfc_dev_pw_id; struct wpabuf *wps_nfc_dh_pubkey; struct wpabuf *wps_nfc_dh_privkey; struct wpabuf *wps_nfc_dev_pw; /** * ext_password_backend - External password backend or %NULL if none * * format: <backend name>[:<optional backend parameters>] */ char *ext_password_backend; /* * p2p_go_max_inactivity - Timeout in seconds to detect STA inactivity * * This timeout value is used in P2P GO mode to clean up * inactive stations. * By default: 300 seconds. */ int p2p_go_max_inactivity; struct hostapd_wmm_ac_params wmm_ac_params[4]; // auto_interworking - Whether to use network selection automatically int auto_interworking; //p2p_go_ht40 - Default mode for HT40 enable when operating as GO. int p2p_go_ht40; // p2p_go_vht - Default mode for VHT enable when operating as GO int p2p_go_vht; int p2p_disabled; //p2p_no_group_iface - Whether group interfaces can be used int p2p_no_group_iface; //okc - Whether to enable opportunistic key caching by default int okc; //pmf - Whether to enable/require PMF by default。默认值为0 //ieee80211w=1 or ieee80211w=2 parameter. pmf=1/2 can be used to change enum mfp_options pmf; //sae_groups - Preference list of enabled groups for SAE int *sae_groups; // dtim_period - Default DTIM period in Beacon intervals int dtim_period; // beacon_int - Default Beacon interval in TU int beacon_int; //ap_vendor_elements: Vendor specific elements for Beacon/ProbeResp struct wpabuf *ap_vendor_elements; //ignore_old_scan_res - Ignore scan results older than request int ignore_old_scan_res; //sched_scan_interval - schedule scan interval unsigned int sched_scan_interval; //tdls_external_control - External control for TDLS setup requests int tdls_external_control; u8 ip_addr_go[4]; u8 ip_addr_mask[4]; u8 ip_addr_start[4]; u8 ip_addr_end[4]; //osu_dir - OSU provider information directory char *osu_dir; //wowlan_triggers - Wake-on-WLAN triggers char *wowlan_triggers; //p2p_search_delay - Extra delay between concurrent search iterations unsigned int p2p_search_delay; //key_mgmt_offload - Use key managment offload int key_mgmt_offload; };

2. network节点

conf文件中每一个network节点都是一个保存的网络，在Android手机扫描结果界面中可以直接点击连接该网络，形式如下 network={ ssid=”ASUS” psk=”**” key_mgmt=WPA-PSK priority=6 } 上述节点中存储了网络的名称（ssid），密码（psk），加密方式（WPA_PSK），优先级（priority） WIFI网络有多种加密方式，每种加密方式（wpa_psk，wep，open，wapi，各种eap等）的节点书写方式都不同，具体可以参考源代码中wpa_supplicant.conf文件 wpa_supplicant.conf

每一个network节点解析后会生成一个struct wpa_ssid，结构体中顶一个多种字段，以满足不同加密方式的需求。

//wpa_supplicant.conf中的网络节点都会生成一个wps_ssid的结构体 struct wpa_ssid{ //链表指针，链表头存放在struct wpa_config->ssid struct wpa_ssid *next; //按照priority组成的链表，链表头在struct wpa_config->pssid struct wpa_ssid *pnext; //每个网络节点都会有一个id，当通过control interface创建时，通过config文件读取时，都会赋予一个id int id; //每个network初始的priority的值是0，当select该bss时，priority会升高 //收到扫描结果时，按照priority由高到低匹配， //当priority相同时，会按照安全协议，信号强度匹配 //注意：AP采用scan_ssid=1 和 ap_scan=2 时，按照config文件中的顺序（wpa_config->ssid）匹配 int priority; //网络标识，可以包含任何字符， u8 *ssid; size_t ssid_len; //如果有该值，是该bssid的AP关联时会用到 //如果disabled == 2，该值为GO的mac u8 bssid[ETH_ALEN]; //对于该network，bssid是否被配置 int bssid_set; //GO的mac地址 u8 go_p2p_dev_addr[ETH_ALEN]; //psk - WPA pre-shared key (256 bits)通过passphrase项的sha生成 u8 psk[32]; //Whether PSK field is configured int psk_set; //如果包含该项，那么连接时采用ssid和passphrase，长度为8~63字符 char *passphrase; //存储PSK的文件路径 char *ext_psk; //pairwise_cipher - Bitfield of allowed pairwise ciphers, WPA_CIPHER_* int pairwise_cipher; //group_cipher - Bitfield of allowed group ciphers, WPA_CIPHER_* int group_cipher; //Bitfield of allowed key management protocols WPA_KEY_MGMT_* int key_mgmt; //背景扫描的间隔（秒），0----disable， -1----使用驱动中默认值 int bg_scan_period; //Bitfield of allowed protocols, WPA_PROTO_* int proto; //Bitfield of allowed authentication algorithms（算法）WPA_AUTH_ALG_* int auth_alg; //放BSS设置为隐藏时，使用该项值写入到Probe Requests， //当某些驱动不支持扫描隐藏网络时，设置ap_mode=2 int scan_ssid; **EAP相关 //Bit field of IEEE 802.1X/EAPOL options (EAPOL_FLAG_*) int eapol_flags; //eap - EAP peer configuration for this network struct eap_peer_config eap; **WEP相关 //wep密码 NUM_WEP_KEYS=4 MAX_WEP_KEY_LEN=16 u8 wep_key[NUM_WEP_KEYS][MAX_WEP_KEY_LEN]; size_t wep_key_len[NUM_WEP_KEYS]; //wep_tx_keyidx - Default key index for TX frames using WEP int wep_tx_keyidx; //什么是proactive key caching？ //1---使能， 0--禁用 //与 PMK， PMKSA， RSN有关 int proactive_key_caching; /** * mixed_cell - Whether mixed cells are allowed * * This option can be used to configure whether so called mixed cells, * i.e., networks that use both plaintext and encryption in the same * SSID, are allowed. This is disabled (0) by default. Enable by * setting this to 1. */ int mixed_cell; #ifdef IEEE8021X_EAPOL //leap - Number of EAP methods using LEAP //LEAP是一种EAP认证，android wifi界面不支持 int leap; //non_leap - Number of EAP methods not using LEAP int non_leap; //eap_workaround - EAP workarounds enabled //跳过关联失败的eap server unsigned int eap_workaround; #endif /* IEEE8021X_EAPOL */ //WPAS模式 enum wpas_mode { WPAS_MODE_INFRA = 0, //征程station模式 WPAS_MODE_IBSS = 1, //IBSS网络，只用station不需要AP组成 WPAS_MODE_AP = 2, //AP， softap WPAS_MODE_P2P_GO = 3, //P2P GO WPAS_MODE_P2P_GROUP_FORMATION = 4, //不能通过config文件设置 } mode; //0---该network可用 //1---该network不可用，可通过 ctrl_iface启用 //2---该network包含P2P参数 int disabled; //WPS网络连接之前，设置该值disable，连接完，取消， int disabled_for_connect; /** * peerkey - Whether PeerKey handshake for direct links is allowed * * This is only used when both RSN/WPA2 and IEEE 802.11e (QoS) are * enabled. * * 0 = disabled (default) * 1 = enabled */ int peerkey; //id_str - Network identifier string for external scripts char *id_str; #ifdef CONFIG_IEEE80211W //ieee80211w - Whether management frame protection is enabled enum mfp_options ieee80211w; { NO_MGMT_FRAME_PROTECTION = 0, MGMT_FRAME_PROTECTION_OPTIONAL = 1, MGMT_FRAME_PROTECTION_REQUIRED = 2, }; #endif /* CONFIG_IEEE80211W */ int frequency; int ht40; int vht; //wpa_ptk_rekey - Maximum lifetime for PTK in seconds //PSK生存时间 int wpa_ptk_rekey; //该network的扫描频率，如果设置了该值，对于该network，只扫描该频率 int *scan_freq; //bgscan 背景扫描设置，参数格式： //<bgscan module name>:<module parameters> char *bgscan; //wpas 在 AP模式时，设置隐藏SSID //0--disable， 1--beacon中ssid长度为0，不对probe request做回应， 2 beacon中ssid内容为‘0’，不对probe request做回应 int ignore_broadcast_ssid; //如果设置了该项，当接收到扫描结果时，如果频率列表不配皮，不在select该bss int *freq_list; //p2p_client_list - List of P2P Clients in a persistent group (GO) //GC的mac地址列表 u8 *p2p_client_list; //num_p2p_clients - Number of entries in p2p_client_list size_t num_p2p_clients; #define P2P_MAX_STORED_CLIENTS 100 //struct psk_list_entry) 链表头 struct dl_list psk_list; struct psk_list_entry { struct dl_list list; u8 addr[ETH_ALEN]; u8 psk[32]; u8 p2p; }; //p2p_group - Network generated as a P2P group (config文件不可配置) int p2p_group; //p2p_persistent_group - Whether this is a persistent group int p2p_persistent_group; //temporary - Whether this network is temporary and not to be saved int temporary; //export_keys - Whether keys may be exported int export_keys; #ifdef CONFIG_HT_OVERRIDES //disable_ht - Disable HT （高吞吐率模式）(IEEE 802.11n) for this network int disable_ht; //disable_ht40 - Disable HT40 for this network int disable_ht40; //disable_sgi - Disable SGI（帧间隔） (Short Guard Interval) for this network int disable_sgi; //disable_ldpc - Disable LDPC（一种编码方式） for this network int disable_ldpc; //ht40_intolerant（不容许） - Indicate 40 MHz intolerant for this network int ht40_intolerant; //disable_max_amsdu - Disable MAX A-MSDU //MSDU一个报文，disable该项，amsdu为3839B，enable则为7935B， //-1则不做任何设置 int disable_max_amsdu; //ampdu_factor - Maximum A-MPDU Length Exponen //Value: 0-3, see 7.3.2.56.3 in IEEE Std 802.11n-2009. int ampdu_factor; /* ampdu_density - Minimum A-MPDU Start Spacing * Value: 0-7, see 7.3.2.56.3 in IEEE Std 802.11n-2009.*/ int ampdu_density; /* ht_mcs - Allowed HT-MCS rates, in ASCII hex: ffff0000... * By default (empty string): Use whatever the OS has configured.*/ char *ht_mcs; #endif /* CONFIG_HT_OVERRIDES */ #ifdef CONFIG_VHT_OVERRIDES /* disable_vht - Disable VHT （束波成型）(IEEE 802.11ac) for this network*/ int disable_vht; //vht_capa - VHT capabilities to use unsigned int vht_capa; //vht_capa_mask - mask for VHT capabilities unsigned int vht_capa_mask; int vht_rx_mcs_nss_1, vht_rx_mcs_nss_2, vht_rx_mcs_nss_3, vht_rx_mcs_nss_4, vht_rx_mcs_nss_5, vht_rx_mcs_nss_6, vht_rx_mcs_nss_7, vht_rx_mcs_nss_8; int vht_tx_mcs_nss_1, vht_tx_mcs_nss_2, vht_tx_mcs_nss_3, vht_tx_mcs_nss_4, vht_tx_mcs_nss_5, vht_tx_mcs_nss_6, vht_tx_mcs_nss_7, vht_tx_mcs_nss_8; #endif /* CONFIG_VHT_OVERRIDES */ /* ap_max_inactivity - Timeout in seconds to detect STA's inactivity * This timeout value is used in AP mode to clean up inactive stations. * By default: 300 seconds. */ int ap_max_inactivity; AP模式 /* dtim_period - DTIM period in Beacon intervals * dtim，间隔多个beacon帧中包含tim信息，tim用于通知station AP有其暂存帧 * By default: 2 */ int dtim_period; //beacon_int - Beacon interval (default: 100 TU) int beacon_int; //auth_failures - Number of consecutive authentication failures unsigned int auth_failures; // disabled_until - Network block disabled until this time if non-zero struct os_reltime disabled_until; void *parent_cred; int macsec_policy; //HS20相关， int update_identifier; unsigned int wps_run; }

3. 操作方法

在conf文件中，可以定义3种节点， wpa_ssid 对应 network ={ }节点： wpa_cred 对应 cred = { }节点 wpa_config_blob 对应参数blob-base64-， 主要介绍wpas_ssid（network ={ }）的作用，其余两个android还没见过 在conf文件中，是按照 项=值 的对应关系对应的， network ={ }中的项和值得对应关系存储在全局变量数组ssid_fields中 其余的全局设置项存储在global_fields中

3.1 wpa_config_read读取参数

//name----conf文件的路径 //cfgp----之前的config数据 //有两个全局数组比较重要， ssid_fields存放network节点的所有可设置值， global_fields存放搜有conf中全局的可设置项 struct wpa_config * wpa_config_read(const char *name, struct wpa_config *cfgp) { //buf存放conf中一行的数据，最长不能超过512 char buf[512], *pos; //生成一个空的config结构体，里面有一些参数提前设置好默认值 struct wpa_config *config = wpa_config_alloc_empty(NULL, NULL); //打开文件 FILE *f = fopen(name, "r"); //循环获取文件中一行 while (wpa_config_get_line(buf, sizeof(buf), f, &line, &pos)) { //network={ if (os_strcmp(pos, "network={") == 0) { //检测到"network={"，进一步读取网络节点的内容 struct wpa_ssid *ssid = wpa_config_read_network(f, &line, id++); { //设置网络节点中一些参数的默认值 wpa_config_set_network_defaults(ssid); //获取每一行的内容，通过‘=’匹配，前面是项名称，后是值 while (wpa_config_get_line(buf, sizeof(buf), f, line, &pos)) { //int wpa_config_set(struct wpa_ssid *ssid, const char *var, const char *value, int line) //ssid中对应项的值，ssid_fields全局数组中，定义了每一项的name，获取值方式 wpa_config_set(ssid, pos, pos2, *line) } //获取完一个network，对内部的信息进行升级 //1.如果设置了passphrase和psk_set，利用sha1生成wpa psk wpa_config_validate_network(ssid, *line); } //将生成的ssid加入到conf->pssid链表中 wpa_config_add_prio_network(config, ssid) } //cred={ else if (os_strcmp(pos, "cred={") == 0) { cred = wpa_config_read_cred(f, &line, cred_id++); } //blob-base64- else if (os_strncmp(pos, "blob-base64-", 12) == 0) { if (wpa_config_process_blob(config, f, &line, pos + 12) } //获取conf中的全局参数，存储在全局数组global_fields else if (wpa_config_process_global(config, pos, line) < 0) { } } }

3.2 wpa_config_write写入参数

int wpa_config_write(const char *name, struct wpa_config *config) { FILE *f; //写入全局项 wpa_config_write_global(f, config); //写入cred节点 for (cred = config->cred; cred; cred = cred->next) { wpa_config_write_cred(f, cred); } //存储network节点 for (ssid = config->ssid; ssid; ssid = ssid->next) { if (ssid->key_mgmt == WPA_KEY_MGMT_WPS || ssid->temporary) continue; /* do not save temporary networks */ if (wpa_key_mgmt_wpa_psk(ssid->key_mgmt) && !ssid->psk_set && !ssid->passphrase) continue; /* do not save invalid network */ wpa_config_write_network(f, ssid); } //写入blob值 for (blob = config->blobs; blob; blob = blob->next) { ret = wpa_config_write_blob(f, blob); } }

3.3 wpa_config_add_network添加网络

调用该函数后，会返回一个预先设置好id的ssid指针

struct wpa_ssid * wpa_config_add_network(struct wpa_config *config) { //遍历得到config->ssid中最大的id + 1 //生成一个空的ssid节点，并添加到config->ssid链表中 ssid->id = id; //更新pssid链表 wpa_config_update_prio_list(config); return ssid; }

wpa_config_get_network获取一个network节点

通过id值获取conf->ssid链表的中network元素

struct wpa_ssid * wpa_config_get_network(struct wpa_config *config, int id) { struct wpa_ssid *ssid = config->ssid; while (ssid) { if (id == ssid->id) break; }

3.4wpa_config_remove_network删除一个network节点

通过id值删除network

int wpa_config_remove_network(struct wpa_config *config, int id) { //通过获取config->ssid链表中id值匹配的ssid元素 struct wpa_ssid *ssid = config->ssid; while (ssid) { if (id == ssid->id) break; } //从链表中删除 //更新pssid列表 wpa_config_update_prio_list(config); //释放空间 wpa_config_free_ssid(ssid); }

3.5wpa_config_set设置network中某项的值

//由外部控制 framework或者wpa_cli int wpa_config_set(struct wpa_ssid *ssid, const char *var, const char *value, int line);