lws-netdev.h

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/*
 * libwebsockets - small server side websockets and web server implementation
 *
 * Copyright (C) 2010 - 2020 Andy Green <andy@warmcat.com>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to
 * deal in the Software without restriction, including without limitation the
 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
 * sell copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
 */
 
#define LWS_WIFI_MAX_SCAN_TRACK 16
#define LWS_ETH_ALEN 6
 
typedef uint8_t lws_wifi_ch_t;
typedef int8_t lws_wifi_rssi_t;
struct lws_netdev_instance;
 
typedef enum {
        LWSNDTYP_UNKNOWN,
        LWSNDTYP_WIFI,
        LWSNDTYP_ETH,
} lws_netdev_type_t;
 
/*
 * Base class for netdev configuration
 */
 
typedef struct lws_netdev_config {
        void                            *plat_config;
} lws_netdev_config_t;
 
/*
 * Const Logical generic network interface ops
 */
 
typedef struct lws_netdev_ops {
        struct lws_netdev_instance * (*create)(struct lws_context *ctx,
                                               const struct lws_netdev_ops *ops,
                                               const char *name, void *platinfo);
        int (*configure)(struct lws_netdev_instance *nd,
                         lws_netdev_config_t *config);
        int (*up)(struct lws_netdev_instance *nd);
        int (*down)(struct lws_netdev_instance *nd);
        int (*event)(struct lws_netdev_instance *nd, lws_usec_t timestamp,
                     void *buf, size_t len);
        /**< these are SMD events coming from lws event loop thread context */
        void (*destroy)(struct lws_netdev_instance **pnd);
        int (*connect)(struct lws_netdev_instance *wnd, const char *ssid,
                            const char *passphrase, uint8_t *bssid);
        void (*scan)(struct lws_netdev_instance *nd);
} lws_netdev_ops_t;
 
/*
 * Network devices on this platform
 *
 * We also hold a list of all known network credentials (when they are needed
 * because there is a network interface without anything to connect to) and
 * the lws_settings instance they are stored in
 */
 
typedef struct lws_netdevs {
        lws_dll2_owner_t                owner;
        /**< list of netdevs / lws_netdev_instance_t -based objects */
 
        lws_dll2_owner_t                owner_creds;
        /**< list of known credentials */
        struct lwsac                    *ac_creds;
        /**< lwsac holding retreived credentials settings, or NULL */
        lws_settings_instance_t         *si;
 
        lws_sockaddr46                  sa46_dns_resolver;
 
        uint8_t                         refcount_creds;
        /**< when there are multiple netdevs, must refcount creds in mem */
} lws_netdevs_t;
 
/*
 * Base class for an allocated instantiated derived object using lws_netdev_ops,
 * ie, a specific ethernet device
 */
 
typedef struct lws_netdev_instance {
        const char                      *name;
        const lws_netdev_ops_t          *ops;
        void                            *platinfo;
        lws_dll2_t                      list;
        uint8_t                         mac[LWS_ETH_ALEN];
        uint8_t                         type; /* lws_netdev_type_t */
} lws_netdev_instance_t;
 
enum {
        LNDIW_ALG_OPEN,
        LNDIW_ALG_WPA2,
 
        LNDIW_MODE_STA                  = (1 << 0),
        LNDIW_MODE_AP                   = (1 << 1),
        LNDIW_UP                        = (1 << 7),
 
        LNDIW_ACQ_IPv4                  = (1 << 0),
        LNDIW_ACQ_IPv6                  = (1 << 1),
};
 
/*
 * Group AP / Station State
 */
 
typedef enum {
        LWSNDVWIFI_STATE_INITIAL,
                /*
                 * We should gratuitously try whatever last worked for us, then
                 * if that fails, worry about the rest of the logic
                 */
        LWSNDVWIFI_STATE_SCAN,
                /*
                 * Unconnected, scanning: AP known in one of the config slots ->
                 * configure it, start timeout + LWSNDVWIFI_STATE_STAT, if no AP
                 * already up in same group with lower MAC, after a random
                 * period start up our AP (LWSNDVWIFI_STATE_AP)
                 */
        LWSNDVWIFI_STATE_AP,
                /* Trying to be the group AP... periodically do a scan
                 * LWSNDVWIFI_STATE_AP_SCAN, faster and then slower
                 */
        LWSNDVWIFI_STATE_AP_SCAN,
                /*
                 * doing a scan while trying to be the group AP... if we see a
                 * lower MAC being the AP for the same group AP, abandon being
                 * an AP and join that AP as a station
                 */
        LWSNDVWIFI_STATE_STAT_GRP_AP,
                /*
                 * We have decided to join another group member who is being the
                 * AP, as its MAC is lower than ours.  This is a stable state,
                 * but we still do periodic scans
                 * LWSNDVWIFI_STATE_STAT_GRP_AP_SCAN and will always prefer an
                 * AP configured in a slot.
                 */
        LWSNDVWIFI_STATE_STAT_GRP_AP_SCAN,
                /*
                 * We have joined a group member who is doing the AP job... we
                 * want to check every now and then if a configured AP has
                 * appeared that we should better use instead.  Otherwise stay
                 * in LWSNDVWIFI_STATE_STAT_GRP_AP
                 */
        LWSNDVWIFI_STATE_STAT,
                /*
                 * trying to connect to another non-group AP. If we don't get an
                 * IP within a timeout and retries, mark it as unusable it and go back
                 */
        LWSNDVWIFI_STATE_STAT_HAPPY,
} lws_netdev_wifi_state_t;
 
/*
 * Generic WIFI credentials
 */
 
typedef struct lws_wifi_creds {
        lws_dll2_t                      list;
 
        uint8_t                         bssid[LWS_ETH_ALEN];
        char                            passphrase[64];
        char                            ssid[33];
        uint8_t                         alg;
} lws_wifi_creds_t;
 
/*
 * Generic WIFI Network Device Instance
 */
 
typedef struct lws_netdev_instance_wifi {
        lws_netdev_instance_t           inst;
        lws_dll2_owner_t                scan; /* sorted scan results */
        lws_sorted_usec_list_t          sul_scan;
 
        lws_wifi_creds_t                *ap_cred;
        const char                      *ap_ip;
 
        const char                      *sta_ads;
 
        char                            current_attempt_ssid[33];
        uint8_t                         current_attempt_bssid[LWS_ETH_ALEN];
 
        uint8_t                         flags;
        uint8_t                         state; /* lws_netdev_wifi_state_t */
} lws_netdev_instance_wifi_t;
 
/*
 * Logical scan results sorted list item
 */
 
typedef struct lws_wifi_sta {
        lws_dll2_t                      list;
 
        uint32_t                        last_seen; /* unix time */
        uint32_t                        last_tried; /* unix time */
 
        uint8_t                         bssid[LWS_ETH_ALEN];
        char                            *ssid; /* points to overallocation */
        uint8_t                         ssid_len;
        lws_wifi_ch_t                   ch;
        lws_wifi_rssi_t                 rssi[8];
        int16_t                         rssi_avg;
        uint8_t                         authmode;
 
        uint8_t                         rssi_count;
        uint8_t                         rssi_next;
 
        /* ssid overallocated afterwards */
} lws_wifi_sta_t;
 
#define rssi_averaged(_x) (_x->rssi_count ?
                ((int)_x->rssi_avg / (int)_x->rssi_count) :
                        -200)
 
LWS_VISIBLE LWS_EXTERN lws_netdevs_t *
lws_netdevs_from_ctx(struct lws_context *ctx);
 
LWS_VISIBLE LWS_EXTERN int
lws_netdev_credentials_settings_set(lws_netdevs_t *nds);
 
LWS_VISIBLE LWS_EXTERN int
lws_netdev_credentials_settings_get(lws_netdevs_t *nds);
 
LWS_VISIBLE LWS_EXTERN struct lws_netdev_instance *
lws_netdev_wifi_create_plat(struct lws_context *ctx,
                            const lws_netdev_ops_t *ops, const char *name,
                            void *platinfo);
LWS_VISIBLE LWS_EXTERN int
lws_netdev_wifi_configure_plat(struct lws_netdev_instance *nd,
                               lws_netdev_config_t *config);
LWS_VISIBLE LWS_EXTERN int
lws_netdev_wifi_event_plat(struct lws_netdev_instance *nd, lws_usec_t timestamp,
                           void *buf, size_t len);
LWS_VISIBLE LWS_EXTERN int
lws_netdev_wifi_up_plat(struct lws_netdev_instance *nd);
LWS_VISIBLE LWS_EXTERN int
lws_netdev_wifi_down_plat(struct lws_netdev_instance *nd);
LWS_VISIBLE LWS_EXTERN void
lws_netdev_wifi_destroy_plat(struct lws_netdev_instance **pnd);
LWS_VISIBLE LWS_EXTERN void
lws_netdev_wifi_scan_plat(lws_netdev_instance_t *nd);
 
LWS_VISIBLE LWS_EXTERN int
lws_netdev_wifi_connect_plat(lws_netdev_instance_t *wnd, const char *ssid,
                             const char *passphrase, uint8_t *bssid);
 
LWS_VISIBLE LWS_EXTERN lws_netdev_instance_t *
lws_netdev_find(lws_netdevs_t *netdevs, const char *ifname);
 
#define lws_netdev_wifi_plat_ops
        .create                         = lws_netdev_wifi_create_plat,
        .configure                      = lws_netdev_wifi_configure_plat,
        .event                          = lws_netdev_wifi_event_plat,
        .up                             = lws_netdev_wifi_up_plat,
        .down                           = lws_netdev_wifi_down_plat,
        .connect                        = lws_netdev_wifi_connect_plat,
        .scan                           = lws_netdev_wifi_scan_plat,
        .destroy                        = lws_netdev_wifi_destroy_plat
 
/*
 * This is for plat / OS level init that is necessary to be able to use
 * networking or wifi at all, without mentioning any specific device
 */
 
LWS_VISIBLE LWS_EXTERN int
lws_netdev_plat_init(void);
 
LWS_VISIBLE LWS_EXTERN int
lws_netdev_plat_wifi_init(void);