diff options
author | Cristian Maglie <c.maglie@bug.st> | 2012-10-18 15:50:09 +0200 |
---|---|---|
committer | Cristian Maglie <c.maglie@bug.st> | 2012-10-18 15:50:09 +0200 |
commit | 6a45ba48ab1f2d0a168373a02ba7fded40a3470e (patch) | |
tree | 163448869b4dfcbce95dc877ffff61a709fba6b6 /firmwares/wifishield/wifiHD/src/wl_cm.c | |
parent | c313b54c00635f1be14a1b09617dc9b8b562e589 (diff) | |
parent | 6d296e0faba5b9910084c307a3f93cb2653bf7f8 (diff) |
Merged upstream arduino branch
Diffstat (limited to 'firmwares/wifishield/wifiHD/src/wl_cm.c')
-rw-r--r-- | firmwares/wifishield/wifiHD/src/wl_cm.c | 437 |
1 files changed, 437 insertions, 0 deletions
diff --git a/firmwares/wifishield/wifiHD/src/wl_cm.c b/firmwares/wifishield/wifiHD/src/wl_cm.c new file mode 100644 index 0000000..bef1afc --- /dev/null +++ b/firmwares/wifishield/wifiHD/src/wl_cm.c @@ -0,0 +1,437 @@ +/* This source file is part of the ATMEL AVR-UC3-SoftwareFramework-1.7.0 Release */ + +/*! \page License + * Copyright (C) 2009, H&D Wireless AB All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * + * 2. Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * + * 3. The name of H&D Wireless AB may not be used to endorse or promote products derived + * from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY H&D WIRELESS AB ``AS IS'' AND ANY EXPRESS OR IMPLIED + * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE EXPRESSLY AND + * SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR ANY DIRECT, + * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES + * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; + * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND + * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF + * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ +#include "wl_cm.h" +#include "util.h" +#include <string.h> +#include "debug.h" + +/** Roaming configuration parameters **/ + +/*! The ROAMING_RSSI_THRESHOLD setting defines how bad the current + * signal strength should be before we'll consider roaming to an AP + * with better signal strength. The objective is to stay on the + * current AP as long as the RSSI is decent, even if there are other + * APs in the same BSS with better RSSI available. + * If ROAMING_RSSI_THRESHOLD is too high we might roam unecessarily. + * If ROAMING_RSSI_THRESHOLD is too low we might not roam in time to + * avoid packet loss. This also impacts power consumption, staying + * too long with an AP with poor RSSI will consume more power. + * Unit is dBm. + */ +#define ROAMING_RSSI_THRESHOLD -65 + +/*! The ROAMING_RSSI_DIFF setting defines how much better + * than the currently associated AP a new AP must be before + * we'll attempt to roam over to the new AP. + * If ROAMING_RSSI_DIFF is too high it might be too hard + * to roam (important if the STA is expected to move + * quickly through different AP coverage areas). + * If ROAMING_RSSI_DIFF is too low we might bounce between + * two APs with similar signal strengths. + * Unit is dBm. + */ +#define ROAMING_RSSI_DIFF 10 + + +#if 1 +# include "printf-stdarg.h" +#include "ard_utils.h" +# define CM_DPRINTF(fmt...) if (enableDebug & INFO_CM_FLAG) printk(fmt) +#else +# define CM_DPRINTF(fmt...) +#endif + + +/** \defgroup wl_cm Connection Manager + * + * These functions are used to configure and control the WiFi connetion + * manager. + * + * + * @{ + */ + +struct cm_candidate { + struct wl_ssid_t ssid; + struct wl_mac_addr_t bssid; +}; + +struct cm { + cm_scan_cb_t *scan_cb; + cm_conn_cb_t *conn_cb; + cm_disconn_cb_t *disconn_cb; + void* ctx; + uint8_t enabled; + struct cm_candidate candidate; +}; + + +/** + * This function can be modified to pick a network based on + * application specific criteria. + * + * If the SSID can not be found in the scan list it will be + * assumed to be a hidden SSID and the wl_connect() command + * will be called to attempt to probe for the network and + * connect to it. + */ +static struct wl_network_t* +find_best_candidate(struct cm* cm) +{ + struct wl_network_list_t* netlist; + struct wl_network_t *best_net = NULL; + uint8_t i; + + if (wl_get_network_list(&netlist) != WL_SUCCESS) + return NULL; + + if (netlist->cnt == 0) + return NULL; + + for (i = 0; i < netlist->cnt; i++) { + /* match on ssid */ + if (cm->candidate.ssid.len) + if (!equal_ssid(&cm->candidate.ssid, + &netlist->net[i]->ssid)) + continue; + + /* match bssid */ + if (strncmp((char*) cm->candidate.bssid.octet, + "\xff\xff\xff\xff\xff\xff", 6)) + if (!equal_bssid(&cm->candidate.bssid, + &netlist->net[i]->bssid)) + continue; + /* check for best rssi. */ + if ( best_net && + ( best_net->rssi > netlist->net[i]->rssi) ) { + continue; + } + best_net = netlist->net[i]; + } + + return best_net; +} + + +/** + * + */ +static void +select_net(struct cm* cm) +{ + struct wl_network_t *candidate_net; + struct wl_network_t *current_net; + struct wl_ssid_t *ssid_p; + + int ret; + + /* Nothing to do */ + if (0 == cm->candidate.ssid.len) { + return; + } + + current_net = wl_get_current_network(); + candidate_net = find_best_candidate(cm); + + /* Connected to the candidate? ... */ + if ( current_net == candidate_net ) { + if ( current_net ) { + /* ...yes, dont change. */ + + return; + } + } + + /* Roaming checks */ + if (current_net && candidate_net) { + /* Are we changing BSSs? */ + if ( equal_ssid(&candidate_net->ssid, + ¤t_net->ssid)) { + + /* ...no. Does the currently connected + * net have a decent RSSI?...*/ + if ( current_net->rssi > ROAMING_RSSI_THRESHOLD ) { + /* ...yes, stay with it. */ + return; + } + /* ...no. Does the candidate have + * sufficiently better RSSI to + * motivate a switch to it? */ + if ( candidate_net->rssi < current_net->rssi + + ROAMING_RSSI_DIFF) { + return; + } + /* ...yes, try to roam to candidate_net */ + CM_DPRINTF("CM: Roaming from rssi %d to %d\n", + current_net->rssi, + candidate_net->rssi); + } + } + /* a candidate is found */ + if (candidate_net) { + /* We connect to a specific bssid here because + * find_best_candidate() might have picked a + * particulare AP among many with the same SSID. + * wl_connect() would pick one of them at random. + */ + ret = wl_connect_bssid(candidate_net->bssid); + } + /* no candidate found */ + else { + CM_DPRINTF("CM: No candidate found for ssid \"%s\"\n", + ssid2str(&cm->candidate.ssid)); + /* Might be a hidden SSID so we try to connect to it. + * wl_connect() will trigger a directed scan + * for the SSID in this case. + */ + ssid_p = &cm->candidate.ssid; + ret = wl_connect(ssid_p->ssid, ssid_p->len); + } + switch (ret) { + case WL_SUCCESS : + return; + case WL_BUSY: + wl_disconnect(); + return; + case WL_RETRY: + break; + default : + CM_DPRINTF("CM: failed to connect\n"); + break; + } + + /* some operation failed or no candidate found */ + if (wl_scan() != WL_SUCCESS) + CM_DPRINTF("CM: failed to scan\n"); +} + + +/** + * + */ +static void +wl_scan_complete_cb(void* ctx) +{ + struct cm *cm = ctx; + + CM_DPRINTF("CM: scan completed\n"); + + if (cm->scan_cb) + cm->scan_cb(cm->ctx); + + if ( 0 == cm->enabled ) { + return; + } + select_net(cm); +} + +/** + * + */ +static void +wl_media_connected_cb(void* ctx) +{ + struct cm *cm = ctx; + struct wl_network_t *net = wl_get_current_network(); + CM_DPRINTF("CM: connected to %s\n", ssid2str(&net->ssid)); + LINK_LED_ON(); + ERROR_LED_OFF(); + if (cm->conn_cb) + cm->conn_cb(net, cm->ctx); +} + + +/** + * + */ +static void +wl_conn_failure_cb(void* ctx) +{ + struct cm *cm = ctx; + CM_DPRINTF("CM: connect failed, scanning\n"); + ERROR_LED_ON(); + LINK_LED_OFF(); + + if ( 0 == cm->enabled ) { + return; + } + if (wl_scan() != WL_SUCCESS) + /* should never happen */ + CM_DPRINTF("CM: could not start scan after connect fail!\n"); +} + + +/** + * + */ +static void +wl_conn_lost_cb(void* ctx) +{ + struct cm *cm = ctx; + CM_DPRINTF("CM: connection lost, scanning\n"); + LINK_LED_OFF(); + if (cm->disconn_cb) + cm->disconn_cb(cm->ctx); + + if ( 0 == cm->enabled ) { + return; + } + if (wl_scan() != WL_SUCCESS) + /* should never happen */ + CM_DPRINTF("CM: could not start scan after connect lost!\n"); +} + + +/** + * + */ +static void +wl_event_cb(struct wl_event_t event, void* ctx) +{ + struct cm *cm = ctx; + + switch (event.id) { + case WL_EVENT_MEDIA_CONNECTED: + wl_media_connected_cb(cm); + break; + + case WL_EVENT_CONN_FAILURE: + wl_conn_failure_cb(cm); + break; + + case WL_EVENT_MEDIA_DISCONNECTED: + CM_DPRINTF("CM: disconnected\n"); + wl_conn_lost_cb(cm); + break; + + case WL_EVENT_SCAN_COMPLETE: + wl_scan_complete_cb(cm); + break; + + default: + CM_DPRINTF("CM: unhandled event\n"); + }; +} + +static struct cm *cm = NULL; + + +/** + * Doesn't actually start the CM, just initializing. CM will run whenever + * an valid ssid is set through wl_cm_set_network() and wl_cm_start() + * has been called. + */ +wl_err_t +wl_cm_init(cm_scan_cb_t scan_cb, + cm_conn_cb_t conn_cb, + cm_disconn_cb_t disconn_cb, + void* ctx) +{ + if (cm != NULL) + return WL_FAILURE; + + cm = calloc(1, sizeof(struct cm)); + if (cm == NULL) { + CM_DPRINTF("CM: out of memory\n"); + return WL_FAILURE; + } + + if (wl_register_event_cb(wl_event_cb, cm) != WL_SUCCESS) { + CM_DPRINTF("CM: could not register event cb\n"); + return WL_FAILURE; + } + + cm->scan_cb = scan_cb; + cm->conn_cb = conn_cb; + cm->disconn_cb = disconn_cb; + cm->enabled = 0; + cm->ctx = ctx; + + CM_DPRINTF("CM: initialized\n"); + return WL_SUCCESS; +} + +wl_err_t +wl_cm_start(void) { + if (NULL == cm) + return WL_FAILURE; + + cm->enabled = 1; + return WL_SUCCESS; +} + +wl_err_t +wl_cm_stop(void) { + if (NULL == cm) + return WL_FAILURE; + + cm->enabled = 0; + return WL_SUCCESS; +} + + +/** + * Set the desired network which the connection manager should try to + * connect to. + * + * The ssid and bssid of the desired network should be specified. The ssid and + * bssid will be matched against the networks found during scan. If any + * parameter is null, it will always match. If both parameters are null, + * the first found network will be chosen. + * + * @param ssid The ssid of the desired network. If null, any ssid will match. + * @param bssid The bssid of the desired network. If null, any bssid will match. + * + */ +wl_err_t +wl_cm_set_network(struct wl_ssid_t *ssid, struct wl_mac_addr_t *bssid) +{ + if (cm == NULL) + return WL_FAILURE; + + if (ssid) + memcpy(&cm->candidate.ssid, ssid, sizeof(cm->candidate.ssid)); + else + cm->candidate.ssid.len = 0; + + if (bssid) + memcpy(&cm->candidate.bssid, bssid, + sizeof(cm->candidate.bssid)); + else + memset(&cm->candidate.bssid, 0xff, sizeof(cm->candidate.bssid)); + + if (cm->candidate.ssid.len) + wl_scan(); + + return WL_SUCCESS; +} +/* + * @} + */ |