wpa_config_read分析

路徑為:external\wpa_supplicant_8\wpa_supplicant\config_file.c

struct wpa_config * wpa_config_read(const char *name, struct wpa_config *cfgp)
{
    FILE *f;
    char buf[512], *pos;
    int errors = 0, line = 0;
    struct wpa_ssid *ssid, *tail = NULL, *head = NULL;
    struct wpa_cred *cred, *cred_tail = NULL
 
, *cred_head = NULL;
    struct wpa_config *config;/*配置檔案在程式碼中對應的資料結構*/
    int id = 0;
    int cred_id = 0;

    if (name == NULL)
        return NULL;
    if (cfgp)
        config = cfgp;
    else
        config = wpa_config_alloc_empty(NULL, NULL);
    if (config == NULL) {
        wpa_printf(MSG_ERROR, "Failed to allocate config file "
 

               "structure");
        return NULL;
    }
    head = config->ssid;
    cred_head = config->cred;

    wpa_printf(MSG_DEBUG, "Reading configuration file '%s'", name);
    f = fopen(name, "r");
    if (f == NULL) {
        wpa_printf(MSG_ERROR, "Failed to open config file '%s', "
               "error: %s"
 
, name, strerror(errno));
        os_free(config);
        return NULL;
    }

    while (wpa_config_get_line(buf, sizeof(buf), f, &line, &pos)) {
        if (os_strcmp(pos, "network={") == 0) {
            /*讀取配置檔案中的network項, 並將其轉化成一個wpa_ssid型別的物件*/
            ssid = wpa_config_read_network(f, &line, id++);
            if (ssid == NULL) {
                wpa_printf(MSG_ERROR, "Line %d: failed to "
                       "parse network block.", line);
                errors++;
                continue;
            }
            if (head == NULL) {/*wpa_ssid通過next成員變數構成了一個單項鍊表*/
                head = tail = ssid;
            } else {
                tail->next = ssid;
                tail = ssid;
            }
            /*network項屬於配置檔案的一部分, 故wpa_ssid物件也包含在wpa_config物件中*/
            if (wpa_config_add_prio_network(config, ssid)) {
                wpa_printf(MSG_ERROR, "Line %d: failed to add "
                       "network block to priority list.",
                       line);
                errors++;
                continue;
            }
        } else if (os_strcmp(pos, "cred={") == 0) {
            cred = wpa_config_read_cred(f, &line, cred_id++);
            if (cred == NULL) {
                wpa_printf(MSG_ERROR, "Line %d: failed to "
                       "parse cred block.", line);
                errors++;
                continue;
            }
            if (cred_head == NULL) {
                cred_head = cred_tail = cred;
            } else {
                cred_tail->next = cred;
                cred_tail = cred;
            }
#ifndef CONFIG_NO_CONFIG_BLOBS
        } else if (os_strncmp(pos, "blob-base64-", 12) == 0) {
            if (wpa_config_process_blob(config, f, &line, pos + 12)
                < 0) {
                wpa_printf(MSG_ERROR, "Line %d: failed to "
                       "process blob.", line);
                errors++;
                continue;
            }
#endif /* CONFIG_NO_CONFIG_BLOBS */
        } else if (wpa_config_process_global(config, pos, line) < 0) {
            wpa_printf(MSG_ERROR, "Line %d: Invalid configuration "
                   "line '%s'.", line, pos);
            errors++;
            continue;
        }
    }

    fclose(f);

    config->ssid = head;
    wpa_config_debug_dump_networks(config);
    config->cred = cred_head;

#ifndef WPA_IGNORE_CONFIG_ERRORS
    if (errors) {
        wpa_config_free(config);
        config = NULL;
        head = NULL;
    }
#endif /* WPA_IGNORE_CONFIG_ERRORS */

    return config;
}

wpa_config和wpa_ssid這兩個資料結構都是配置檔案中的資訊在程式碼中的反映. 可以檢視wpa_suppilcant.conf配置模板檔案來了解各個配置項的含義.

wpa_supplicant_init_iface分析

static int wpa_supplicant_init_iface(struct wpa_supplicant *wpa_s,
                     struct wpa_interface *iface)
{
...
    /*將wpa_interface中的ifname複製到wpa_supplicant的ifname變數中*/
    os_strlcpy(wpa_s->ifname, iface->ifname, sizeof(wpa_s->ifname));
...
    /* 下面這兩個函式和EAPOL狀態機相關 RSNA Supplicant Key Management - INITIALIZE */
    eapol_sm_notify_portEnabled(wpa_s->eapol, FALSE);
    eapol_sm_notify_portValid(wpa_s->eapol, FALSE);
...
}

wpa_supplicant_set_driver會根據driver(wlan驅動)名找到wpa_drivers陣列中的nl80211指定的wpa_supplicant中driver的物件wpa_driver_nl80211_ops,然後呼叫它的global_init函式.

路徑:external\wpa_supplicant_8\src\drivers\driver_nl80211.c