路径为:external\wpa_supplicant_8\wpa_supplicant\wpa_supplicant.c
/** * wpa_supplicant_add_iface - Add a new network interface * @global: Pointer to global data from wpa_supplicant_init() * @iface: Interface configuration options * Returns: Pointer to the created interface or %NULL on failure * * This function is used to add new network interfaces for %wpa_supplicant. * This can be called before wpa_supplicant_run() to add interfaces before the * main event loop has been started. In addition, new interfaces can be added * dynamically while %wpa_supplicant is already running. This could happen, * e.g., when a hotplug network adapter is inserted. */
struct wpa_supplicant * wpa_supplicant_add_iface(struct wpa_global *global,
struct wpa_interface *iface)
{
struct wpa_supplicant *wpa_s;
struct wpa_interface t_iface;
struct wpa_ssid *ssid;
if (global == NULL || iface == NULL)
return NULL;
wpa_s = wpa_supplicant_alloc();
if (wpa_s == NULL)
return NULL;
wpa_s->global = global;
t_iface = *iface;
if (global->params.override_driver) {
wpa_printf(MSG_DEBUG, "Override interface parameter: driver "
"('%s' -> '%s')",
iface->driver, global->params.override_driver);
t_iface.driver = global->params.override_driver;
}
if (global->params.override_ctrl_interface) {
wpa_printf(MSG_DEBUG, "Override interface parameter: "
"ctrl_interface ('%s' -> '%s')",
iface->ctrl_interface,
global->params.override_ctrl_interface);
t_iface.ctrl_interface =
global->params.override_ctrl_interface;
}
/*重要*/
if (wpa_supplicant_init_iface(wpa_s, &t_iface)) {
wpa_printf(MSG_DEBUG, "Failed to add interface %s",
iface->ifname);
wpa_supplicant_deinit_iface(wpa_s, 0, 0);
return NULL;
}
/* 通过dbus通知外接有新的iface加入 Notify the control interfaces about new iface */
if (wpas_notify_iface_added(wpa_s)) {
wpa_supplicant_deinit_iface(wpa_s, 1, 0);
return NULL;
}
/*通过dbus通知外界有新的无线网络加入*/
for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next)
wpas_notify_network_added(wpa_s, ssid);
/* wpa_global的ifaces变量指向一个wpa_supplicant对象, * 而wpa_supplicant又通过next变量将自己链接到一个单项链表中*/
wpa_s->next = global->ifaces;
global->ifaces = wpa_s;
wpa_dbg(wpa_s, MSG_DEBUG, "Added interface %s", wpa_s->ifname);
wpa_supplicant_set_state(wpa_s, WPA_DISCONNECTED);
return wpa_s;
}
wpa_supplicant_add_iface函数的内容非常丰富, 包括两个重要数据结构(wpa_supplicant和wpa_ssid)以及一个关键函数wpa_supplicant_init_iface.这些数据背景较多, 先来看看他们.
wpa_ssid结构体
wpa_ssid结构体用于存储某个无线网络的配置信息(如所支持的安全类型, 优先级等). (external\wpa_supplicant_8\wpa_supplicant\wpa_supplicant.conf)文件中的每一个network项都对应一个wpa_ssid对象.
路径为:external\wpa_supplicant_8\wpa_supplicant\config_ssid.h
/** * struct wpa_ssid - Network configuration data * * This structure includes all the configuration variables for a network. This * data is included in the per-interface configuration data as an element of * the network list, struct wpa_config::ssid. Each network block in the * configuration is mapped to a struct wpa_ssid instance. * */
struct wpa_ssid {
/** * next - Next network in global list * * This pointer can be used to iterate over all networks. The head of * this list is stored in the ssid field of struct wpa_config. */
struct wpa_ssid *next;/*所有wpa_ssid对象都保存在一个链表当中, 头指针保存于另外一个结构体wpa_config的ssid变量中*/
/** * pnext - Next network in per-priority list * * This pointer can be used to iterate over all networks in the same * priority class. The heads of these list are stored in the pssid * fields of struct wpa_config. */
struct wpa_ssid *pnext;/*wpa_ssid还可以按priority保存在另一个链表中, 头指针为wpa_config的ssid变量*/
/** * id - Unique id for the network * * This identifier is used as a unique identifier for each network * block when using the control interface. Each network is allocated an * id when it is being created, either when reading the configuration * file or when a new network is added through the control interface. */
int id;/*每个无线网络都有一个唯一的编号*/
/** * priority - Priority group * * By default, all networks will get same priority group (0). If some * of the networks are more desirable, this field can be used to change * the order in which wpa_supplicant goes through the networks when * selecting a BSS. The priority groups will be iterated in decreasing * priority (i.e., the larger the priority value, the sooner the * network is matched against the scan results). Within each priority * group, networks will be selected based on security policy, signal * strength, etc. * * Please note that AP scanning with scan_ssid=1 and ap_scan=2 mode are * not using this priority to select the order for scanning. Instead, * they try the networks in the order that used in the configuration * file. */
int priority;/*该无线网络对应的priority值, 默认为0*/
/** * ssid - Service set identifier (network name) * * This is the SSID for the network. For wireless interfaces, this is * used to select which network will be used. If set to %NULL (or * ssid_len=0), any SSID can be used. For wired interfaces, this must * be set to %NULL. Note: SSID may contain any characters, even nul * (ASCII 0) and as such, this should not be assumed to be a nul * terminated string. ssid_len defines how many characters are valid * and the ssid field is not guaranteed to be nul terminated. */
u8 *ssid;/*无线网络的名字*/
/** * ssid_len - Length of the SSID */
size_t ssid_len;/*ssid变量长度*/
/** * bssid - BSSID * * If set, this network block is used only when associating with the AP * using the configured BSSID * * If this is a persistent P2P group (disabled == 2), this is the GO * Device Address. */
u8 bssid[ETH_ALEN];/*用于保存bssid[ETH_ALEN]*/
/** * bssid_set - Whether BSSID is configured for this network */
int bssid_set;/*该无线网络是否设置了bssid变量*/
/** * psk - WPA pre-shared key (256 bits) */
u8 psk[32];/*数组长度为32, 用于保存WPA中的Pre-Shared Key (256位)*/
/** * psk_set - Whether PSK field is configured */
int psk_set;/*是否设置了上面的psk参数*/
/** * passphrase - WPA ASCII passphrase * * If this is set, psk will be generated using the SSID and passphrase * configured for the network. ASCII passphrase must be between 8 and * 63 characters (inclusive). */
char *passphrase;/*为WPA设置ASCII字符密码*/
/** * ext_psk - PSK/passphrase name in external storage * * If this is set, PSK/passphrase will be fetched from external storage * when requesting association with the network. */
char *ext_psk;
/** * pairwise_cipher - Bitfield of allowed pairwise ciphers, WPA_CIPHER_* */
int pairwise_cipher;/*用于单播数据加密的密钥类型*/
/** * group_cipher - Bitfield of allowed group ciphers, WPA_CIPHER_* */
int group_cipher;/*用于数组数据加密的密钥类型*/
/** * key_mgmt - Bitfield of allowed key management protocols * * WPA_KEY_MGMT_* */
int key_mgmt;/*密钥管理类型*/
/** * bg_scan_period - Background scan period in seconds, 0 to disable, or * -1 to indicate no change to default driver configuration */
int bg_scan_period;
/** * proto - Bitfield of allowed protocols, WPA_PROTO_* */
int proto;/*该无线网络支持的安全保护类型*/
/** * auth_alg - Bitfield of allowed authentication algorithms * * WPA_AUTH_ALG_* */
int auth_alg;/*该无线网络支持的身份验证类型*/
/** * scan_ssid - Scan this SSID with Probe Requests * * scan_ssid can be used to scan for APs using hidden SSIDs. * Note: Many drivers do not support this. ap_mode=2 can be used with * such drivers to use hidden SSIDs. */
int scan_ssid;/*是否利用probe request帧扫描此ssid对应的无线网络*/
#ifdef IEEE8021X_EAPOL
#define EAPOL_FLAG_REQUIRE_KEY_UNICAST BIT(0)
#define EAPOL_FLAG_REQUIRE_KEY_BROADCAST BIT(1)
/** * eapol_flags - Bit field of IEEE 802.1X/EAPOL options (EAPOL_FLAG_*) */
int eapol_flags;/*EAPOL选项*/
/** * eap - EAP peer configuration for this network */
struct eap_peer_config eap;/*eap peer端设置信息*/
#endif /* IEEE8021X_EAPOL */
#define NUM_WEP_KEYS 4
#define MAX_WEP_KEY_LEN 16
/** * wep_key - WEP keys */
u8 wep_key[NUM_WEP_KEYS][MAX_WEP_KEY_LEN];
/** * wep_key_len - WEP key lengths */
size_t wep_key_len[NUM_WEP_KEYS];
/** * wep_tx_keyidx - Default key index for TX frames using WEP */
int wep_tx_keyidx;
/** * proactive_key_caching - Enable proactive key caching * * This field can be used to enable proactive key caching which is also * known as opportunistic PMKSA caching for WPA2. This is disabled (0) * by default unless default value is changed with the global okc=1 * parameter. Enable by setting this to 1. * * Proactive key caching is used to make supplicant assume that the APs * are using the same PMK and generate PMKSA cache entries without * doing RSN pre-authentication. This requires support from the AP side * and is normally used with wireless switches that co-locate the * authenticator. * * Internally, special value -1 is used to indicate that the parameter * was not specified in the configuration (i.e., default behavior is * followed). */
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 * * This field should be set to 1 if LEAP is enabled. This is used to * select IEEE 802.11 authentication algorithm. */
int leap;
/** * non_leap - Number of EAP methods not using LEAP * * This field should be set to >0 if any EAP method other than LEAP is * enabled. This is used to select IEEE 802.11 authentication * algorithm. */
int non_leap;
/** * eap_workaround - EAP workarounds enabled * * wpa_supplicant supports number of "EAP workarounds" to work around * interoperability issues with incorrectly behaving authentication * servers. This is recommended to be enabled by default because some * of the issues are present in large number of authentication servers. * * Strict EAP conformance mode can be configured by disabling * workarounds with eap_workaround = 0. */
unsigned int eap_workaround;
#endif /* IEEE8021X_EAPOL */
/** * mode - IEEE 802.11 operation mode (Infrastucture/IBSS) * * 0 = infrastructure (Managed) mode, i.e., associate with an AP. * * 1 = IBSS (ad-hoc, peer-to-peer) * * 2 = AP (access point) * * 3 = P2P Group Owner (can be set in the configuration file) * * 4 = P2P Group Formation (used internally; not in configuration * files) * * Note: IBSS can only be used with key_mgmt NONE (plaintext and * static WEP) and key_mgmt=WPA-NONE (fixed group key TKIP/CCMP). In * addition, ap_scan has to be set to 2 for IBSS. WPA-None requires * following network block options: proto=WPA, key_mgmt=WPA-NONE, * pairwise=NONE, group=TKIP (or CCMP, but not both), and psk must also * be set (either directly or using ASCII passphrase). */
enum wpas_mode {
WPAS_MODE_INFRA = 0,
WPAS_MODE_IBSS = 1,
WPAS_MODE_AP = 2,
WPAS_MODE_P2P_GO = 3,
WPAS_MODE_P2P_GROUP_FORMATION = 4,
} mode;
/** * disabled - Whether this network is currently disabled * * 0 = this network can be used (default). * 1 = this network block is disabled (can be enabled through * ctrl_iface, e.g., with wpa_cli or wpa_gui). * 2 = this network block includes parameters for a persistent P2P * group (can be used with P2P ctrl_iface commands) */
int disabled;
/** * disabled_for_connect - Whether this network was temporarily disabled * * This flag is used to reenable all the temporarily disabled networks * after either the success or failure of a WPS connection. */
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 * * This value is passed to external ctrl_iface monitors in * WPA_EVENT_CONNECTED event and wpa_cli sets this as WPA_ID_STR * environment variable for action scripts. */
char *id_str;
#ifdef CONFIG_IEEE80211W
/** * ieee80211w - Whether management frame protection is enabled * * This value is used to configure policy for management frame * protection (IEEE 802.11w). 0 = disabled, 1 = optional, 2 = required. * This is disabled by default unless the default value has been changed * with the global pmf=1/2 parameter. * * Internally, special value 3 is used to indicate that the parameter * was not specified in the configuration (i.e., default behavior is * followed). */
enum mfp_options ieee80211w;
#endif /* CONFIG_IEEE80211W */
/** * frequency - Channel frequency in megahertz (MHz) for IBSS * * This value is used to configure the initial channel for IBSS (adhoc) * networks, e.g., 2412 = IEEE 802.11b/g channel 1. It is ignored in * the infrastructure mode. In addition, this value is only used by the * station that creates the IBSS. If an IBSS network with the * configured SSID is already present, the frequency of the network * will be used instead of this configured value. */
int frequency;
int ht40;
/** * wpa_ptk_rekey - Maximum lifetime for PTK in seconds * * This value can be used to enforce rekeying of PTK to mitigate some * attacks against TKIP deficiencies. */
int wpa_ptk_rekey;
/** * scan_freq - Array of frequencies to scan or %NULL for all * * This is an optional zero-terminated array of frequencies in * megahertz (MHz) to include in scan requests when searching for this * network. This can be used to speed up scanning when the network is * known to not use all possible channels. */
int *scan_freq;
/** * bgscan - Background scan and roaming parameters or %NULL if none * * This is an optional set of parameters for background scanning and * roaming within a network (ESS) in following format: * <bgscan module name>:<module parameters> */
char *bgscan;
/** * ignore_broadcast_ssid - Hide SSID in AP mode * * Send empty SSID in beacons and ignore probe request frames that do * not specify full SSID, i.e., require stations to know SSID. * default: disabled (0) * 1 = send empty (length=0) SSID in beacon and ignore probe request * for broadcast SSID * 2 = clear SSID (ASCII 0), but keep the original length (this may be * required with some clients that do not support empty SSID) and * ignore probe requests for broadcast SSID */
int ignore_broadcast_ssid;
/** * freq_list - Array of allowed frequencies or %NULL for all * * This is an optional zero-terminated array of frequencies in * megahertz (MHz) to allow for selecting the BSS. If set, scan results * that do not match any of the specified frequencies are not * considered when selecting a BSS. */
int *freq_list;
/** * p2p_client_list - List of P2P Clients in a persistent group (GO) * * This is a list of P2P Clients (P2P Device Address) that have joined * the persistent group. This is maintained on the GO for persistent * group entries (disabled == 2). */
u8 *p2p_client_list;
/** * num_p2p_clients - Number of entries in p2p_client_list */
size_t num_p2p_clients;
#ifndef P2P_MAX_STORED_CLIENTS
#define P2P_MAX_STORED_CLIENTS 100
#endif /* P2P_MAX_STORED_CLIENTS */
/** * psk_list - Per-client PSKs (struct psk_list_entry) */
struct dl_list psk_list;
/** * p2p_group - Network generated as a P2P group (used internally) */
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 * * This attribute will be set when keys are determined through * WPS or similar so that they may be exported. */
int export_keys;
#ifdef ANDROID_P2P
/** * assoc_retry - Number of times association should be retried. */
int assoc_retry;
#endif
#ifdef CONFIG_HT_OVERRIDES
/** * disable_ht - Disable HT (IEEE 802.11n) for this network * * By default, use it if it is available, but this can be configured * to 1 to have it disabled. */
int disable_ht;
/** * disable_ht40 - Disable HT40 for this network * * By default, use it if it is available, but this can be configured * to 1 to have it disabled. */
int disable_ht40;
/** * disable_sgi - Disable SGI (Short Guard Interval) for this network * * By default, use it if it is available, but this can be configured * to 1 to have it disabled. */
int disable_sgi;
/** * disable_max_amsdu - Disable MAX A-MSDU * * A-MDSU will be 3839 bytes when disabled, or 7935 * when enabled (assuming it is otherwise supported) * -1 (default) means do not apply any settings to the kernel. */
int disable_max_amsdu;
/** * ampdu_factor - Maximum A-MPDU Length Exponent * * 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 (IEEE 802.11ac) for this network * * By default, use it if it is available, but this can be configured * to 1 to have it disabled. */
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;
/** * dtim_period - DTIM period in Beacon intervals * 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_time disabled_until;
/** * parent_cred - Pointer to parent wpa_cred entry * * This pointer can be used to delete temporary networks when a wpa_cred * that was used to create them is removed. This pointer should not be * dereferences since it may not be updated in all cases. */
void *parent_cred;
};
