/** * Functions implementing wlan scan IOCTL and firmware command APIs * * IOCTL handlers as well as command preperation and response routines * for sending scan commands to the firmware. */ #include #include #include #include #include #include #include #include #include "host.h" #include "decl.h" #include "dev.h" #include "scan.h" #include "assoc.h" #include "cmd.h" //! Approximate amount of data needed to pass a scan result back to iwlist #define MAX_SCAN_CELL_SIZE (IW_EV_ADDR_LEN \ + IW_ESSID_MAX_SIZE \ + IW_EV_UINT_LEN \ + IW_EV_FREQ_LEN \ + IW_EV_QUAL_LEN \ + IW_ESSID_MAX_SIZE \ + IW_EV_PARAM_LEN \ + 40) /* 40 for WPAIE */ //! Memory needed to store a max sized channel List TLV for a firmware scan #define CHAN_TLV_MAX_SIZE (sizeof(struct mrvlietypesheader) \ + (MRVDRV_MAX_CHANNELS_PER_SCAN \ * sizeof(struct chanscanparamset))) //! Memory needed to store a max number/size SSID TLV for a firmware scan #define SSID_TLV_MAX_SIZE (1 * sizeof(struct mrvlietypes_ssidparamset)) //! Maximum memory needed for a cmd_ds_802_11_scan with all TLVs at max #define MAX_SCAN_CFG_ALLOC (sizeof(struct cmd_ds_802_11_scan) \ + CHAN_TLV_MAX_SIZE + SSID_TLV_MAX_SIZE) //! The maximum number of channels the firmware can scan per command #define MRVDRV_MAX_CHANNELS_PER_SCAN 14 /** * @brief Number of channels to scan per firmware scan command issuance. * * Number restricted to prevent hitting the limit on the amount of scan data * returned in a single firmware scan command. */ #define MRVDRV_CHANNELS_PER_SCAN_CMD 4 //! Scan time specified in the channel TLV for each channel for passive scans #define MRVDRV_PASSIVE_SCAN_CHAN_TIME 100 //! Scan time specified in the channel TLV for each channel for active scans #define MRVDRV_ACTIVE_SCAN_CHAN_TIME 100 static int lbs_ret_80211_scan(struct lbs_private *priv, unsigned long dummy, struct cmd_header *resp); /*********************************************************************/ /* */ /* Misc helper functions */ /* */ /*********************************************************************/ /** * @brief Unsets the MSB on basic rates * * Scan through an array and unset the MSB for basic data rates. * * @param rates buffer of data rates * @param len size of buffer */ static void lbs_unset_basic_rate_flags(u8 *rates, size_t len) { int i; for (i = 0; i < len; i++) rates[i] &= 0x7f; } static inline void clear_bss_descriptor(struct bss_descriptor *bss) { /* Don't blow away ->list, just BSS data */ memset(bss, 0, offsetof(struct bss_descriptor, list)); } /** * @brief Compare two SSIDs * * @param ssid1 A pointer to ssid to compare * @param ssid2 A pointer to ssid to compare * * @return 0: ssid is same, otherwise is different */ int lbs_ssid_cmp(uint8_t *ssid1, uint8_t ssid1_len, uint8_t *ssid2, uint8_t ssid2_len) { if (ssid1_len != ssid2_len) return -1; return memcmp(ssid1, ssid2, ssid1_len); } static inline int match_bss_no_security(struct lbs_802_11_security *secinfo, struct bss_descriptor *match_bss) { if (!secinfo->wep_enabled && !secinfo->WPAenabled && !secinfo->WPA2enabled && match_bss->wpa_ie[0] != MFIE_TYPE_GENERIC && match_bss->rsn_ie[0] != MFIE_TYPE_RSN && !(match_bss->capability & WLAN_CAPABILITY_PRIVACY)) return 1; else return 0; } static inline int match_bss_static_wep(struct lbs_802_11_security *secinfo, struct bss_descriptor *match_bss) { if (secinfo->wep_enabled && !secinfo->WPAenabled && !secinfo->WPA2enabled && (match_bss->capability & WLAN_CAPABILITY_PRIVACY)) return 1; else return 0; } static inline int match_bss_wpa(struct lbs_802_11_security *secinfo, struct bss_descriptor *match_bss) { if (!secinfo->wep_enabled && secinfo->WPAenabled && (match_bss->wpa_ie[0] == MFIE_TYPE_GENERIC) /* privacy bit may NOT be set in some APs like LinkSys WRT54G && (match_bss->capability & WLAN_CAPABILITY_PRIVACY) */ ) return 1; else return 0; } static inline int match_bss_wpa2(struct lbs_802_11_security *secinfo, struct bss_descriptor *match_bss) { if (!secinfo->wep_enabled && secinfo->WPA2enabled && (match_bss->rsn_ie[0] == MFIE_TYPE_RSN) /* privacy bit may NOT be set in some APs like LinkSys WRT54G && (match_bss->capability & WLAN_CAPABILITY_PRIVACY) */ ) return 1; else return 0; } static inline int match_bss_dynamic_wep(struct lbs_802_11_security *secinfo, struct bss_descriptor *match_bss) { if (!secinfo->wep_enabled && !secinfo->WPAenabled && !secinfo->WPA2enabled && (match_bss->wpa_ie[0] != MFIE_TYPE_GENERIC) && (match_bss->rsn_ie[0] != MFIE_TYPE_RSN) && (match_bss->capability & WLAN_CAPABILITY_PRIVACY)) return 1; else return 0; } static inline int is_same_network(struct bss_descriptor *src, struct bss_descriptor *dst) { /* A network is only a duplicate if the channel, BSSID, and ESSID * all match. We treat all with the same BSSID and channel * as one network */ return ((src->ssid_len == dst->ssid_len) && (src->channel == dst->channel) && !compare_ether_addr(src->bssid, dst->bssid) && !memcmp(src->ssid, dst->ssid, src->ssid_len)); } /** * @brief Check if a scanned network compatible with the driver settings * * WEP WPA WPA2 ad-hoc encrypt Network * enabled enabled enabled AES mode privacy WPA WPA2 Compatible * 0 0 0 0 NONE 0 0 0 yes No security * 1 0 0 0 NONE 1 0 0 yes Static WEP * 0 1 0 0 x 1x 1 x yes WPA * 0 0 1 0 x 1x x 1 yes WPA2 * 0 0 0 1 NONE 1 0 0 yes Ad-hoc AES * 0 0 0 0 !=NONE 1 0 0 yes Dynamic WEP * * * @param priv A pointer to struct lbs_private * @param index Index in scantable to check against current driver settings * @param mode Network mode: Infrastructure or IBSS * * @return Index in scantable, or error code if negative */ static int is_network_compatible(struct lbs_private *priv, struct bss_descriptor *bss, uint8_t mode) { int matched = 0; lbs_deb_enter(LBS_DEB_SCAN); if (bss->mode != mode) goto done; if ((matched = match_bss_no_security(&priv->secinfo, bss))) { goto done; } else if ((matched = match_bss_static_wep(&priv->secinfo, bss))) { goto done; } else if ((matched = match_bss_wpa(&priv->secinfo, bss))) { lbs_deb_scan("is_network_compatible() WPA: wpa_ie 0x%x " "wpa2_ie 0x%x WEP %s WPA %s WPA2 %s " "privacy 0x%x\n", bss->wpa_ie[0], bss->rsn_ie[0], priv->secinfo.wep_enabled ? "e" : "d", priv->secinfo.WPAenabled ? "e" : "d", priv->secinfo.WPA2enabled ? "e" : "d", (bss->capability & WLAN_CAPABILITY_PRIVACY)); goto done; } else if ((matched = match_bss_wpa2(&priv->secinfo, bss))) { lbs_deb_scan("is_network_compatible() WPA2: wpa_ie 0x%x " "wpa2_ie 0x%x WEP %s WPA %s WPA2 %s " "privacy 0x%x\n", bss->wpa_ie[0], bss->rsn_ie[0], priv->secinfo.wep_enabled ? "e" : "d", priv->secinfo.WPAenabled ? "e" : "d", priv->secinfo.WPA2enabled ? "e" : "d", (bss->capability & WLAN_CAPABILITY_PRIVACY)); goto done; } else if ((matched = match_bss_dynamic_wep(&priv->secinfo, bss))) { lbs_deb_scan("is_network_compatible() dynamic WEP: " "wpa_ie 0x%x wpa2_ie 0x%x privacy 0x%x\n", bss->wpa_ie[0], bss->rsn_ie[0], (bss->capability & WLAN_CAPABILITY_PRIVACY)); goto done; } /* bss security settings don't match those configured on card */ lbs_deb_scan("is_network_compatible() FAILED: wpa_ie 0x%x " "wpa2_ie 0x%x WEP %s WPA %s WPA2 %s privacy 0x%x\n", bss->wpa_ie[0], bss->rsn_ie[0], priv->secinfo.wep_enabled ? "e" : "d", priv->secinfo.WPAenabled ? "e" : "d", priv->secinfo.WPA2enabled ? "e" : "d", (bss->capability & WLAN_CAPABILITY_PRIVACY)); done: lbs_deb_leave_args(LBS_DEB_SCAN, "matched: %d", matched); return matched; } /*********************************************************************/ /* */ /* Main scanning support */ /* */ /*********************************************************************/ /** * @brief Create a channel list for the driver to scan based on region info * * Only used from lbs_scan_setup_scan_config() * * Use the driver region/band information to construct a comprehensive list * of channels to scan. This routine is used for any scan that is not * provided a specific channel list to scan. * * @param priv A pointer to struct lbs_private structure * @param scanchanlist Output parameter: resulting channel list to scan * * @return void */ static int lbs_scan_create_channel_list(struct lbs_private *priv, struct chanscanparamset *scanchanlist) { struct region_channel *scanregion; struct chan_freq_power *cfp; int rgnidx; int chanidx; int nextchan; uint8_t scantype; chanidx = 0; /* Set the default scan type to the user specified type, will later * be changed to passive on a per channel basis if restricted by * regulatory requirements (11d or 11h) */ scantype = CMD_SCAN_TYPE_ACTIVE; for (rgnidx = 0; rgnidx < ARRAY_SIZE(priv->region_channel); rgnidx++) { if (priv->enable11d && (priv->connect_status != LBS_CONNECTED) && (priv->mesh_connect_status != LBS_CONNECTED)) { /* Scan all the supported chan for the first scan */ if (!priv->universal_channel[rgnidx].valid) continue; scanregion = &priv->universal_channel[rgnidx]; /* clear the parsed_region_chan for the first scan */ memset(&priv->parsed_region_chan, 0x00, sizeof(priv->parsed_region_chan)); } else { if (!priv->region_channel[rgnidx].valid) continue; scanregion = &priv->region_channel[rgnidx]; } for (nextchan = 0; nextchan < scanregion->nrcfp; nextchan++, chanidx++) { struct chanscanparamset *chan = &scanchanlist[chanidx]; cfp = scanregion->CFP + nextchan; if (priv->enable11d) scantype = lbs_get_scan_type_11d(cfp->channel, &priv->parsed_region_chan); if (scanregion->band == BAND_B || scanregion->band == BAND_G) chan->radiotype = CMD_SCAN_RADIO_TYPE_BG; if (scantype == CMD_SCAN_TYPE_PASSIVE) { chan->maxscantime = cpu_to_le16(MRVDRV_PASSIVE_SCAN_CHAN_TIME); chan->chanscanmode.passivescan = 1; } else { chan->maxscantime = cpu_to_le16(MRVDRV_ACTIVE_SCAN_CHAN_TIME); chan->chanscanmode.passivescan = 0; } chan->channumber = cfp->channel; } } return chanidx; } /* * Add SSID TLV of the form: * * TLV-ID SSID 00 00 * length 06 00 * ssid 4d 4e 54 45 53 54 */ static int lbs_scan_add_ssid_tlv(struct lbs_private *priv, u8 *tlv) { struct mrvlietypes_ssidparamset *ssid_tlv = (void *)tlv; ssid_tlv->header.type = cpu_to_le16(TLV_TYPE_SSID); ssid_tlv->header.len = cpu_to_le16(priv->scan_ssid_len); memcpy(ssid_tlv->ssid, priv->scan_ssid, priv->scan_ssid_len); return sizeof(ssid_tlv->header) + priv->scan_ssid_len; } /* * Add CHANLIST TLV of the form * * TLV-ID CHANLIST 01 01 * length 5b 00 * channel 1 00 01 00 00 00 64 00 * radio type 00 * channel 01 * scan type 00 * min scan time 00 00 * max scan time 64 00 * channel 2 00 02 00 00 00 64 00 * channel 3 00 03 00 00 00 64 00 * channel 4 00 04 00 00 00 64 00 * channel 5 00 05 00 00 00 64 00 * channel 6 00 06 00 00 00 64 00 * channel 7 00 07 00 00 00 64 00 * channel 8 00 08 00 00 00 64 00 * channel 9 00 09 00 00 00 64 00 * channel 10 00 0a 00 00 00 64 00 * channel 11 00 0b 00 00 00 64 00 * channel 12 00 0c 00 00 00 64 00 * channel 13 00 0d 00 00 00 64 00 * */ static int lbs_scan_add_chanlist_tlv(uint8_t *tlv, struct chanscanparamset *chan_list, int chan_count) { size_t size = sizeof(struct chanscanparamset) *chan_count; struct mrvlietypes_chanlistparamset *chan_tlv = (void *)tlv; chan_tlv->header.type = cpu_to_le16(TLV_TYPE_CHANLIST); memcpy(chan_tlv->chanscanparam, chan_list, size); chan_tlv->header.len = cpu_to_le16(size); return sizeof(chan_tlv->header) + size; } /* * Add RATES TLV of the form * * TLV-ID RATES 01 00 * length 0e 00 * rates 82 84 8b 96 0c 12 18 24 30 48 60 6c * * The rates are in lbs_bg_rates[], but for the 802.11b * rates the high bit isn't set. */ static int lbs_scan_add_rates_tlv(uint8_t *tlv) { int i; struct mrvlietypes_ratesparamset *rate_tlv = (void *)tlv; rate_tlv->header.type = cpu_to_le16(TLV_TYPE_RATES); tlv += sizeof(rate_tlv->header); for (i = 0; i < MAX_RATES; i++) { *tlv = lbs_bg_rates[i]; if (*tlv == 0) break; /* This code makes sure that the 802.11b rates (1 MBit/s, 2 MBit/s, 5.5 MBit/s and 11 MBit/s get's the high bit set. Note that the values are MBit/s * 2, to mark them as basic rates so that the firmware likes it better */ if (*tlv == 0x02 || *tlv == 0x04 || *tlv == 0x0b || *tlv == 0x16) *tlv |= 0x80; tlv++; } rate_tlv->header.len = cpu_to_le16(i); return sizeof(rate_tlv->header) + i; } /* * Generate the CMD_802_11_SCAN command with the proper tlv * for a bunch of channels. */ static int lbs_do_scan(struct lbs_private *priv, uint8_t bsstype, struct chanscanparamset *chan_list, int chan_count) { int ret = -ENOMEM; struct cmd_ds_802_11_scan *scan_cmd; uint8_t *tlv; /* pointer into our current, growing TLV storage area */ lbs_deb_enter_args(LBS_DEB_SCAN, "bsstype %d, chanlist[].chan %d, chan_count %d", bsstype, chan_list[0].channumber, chan_count); /* create the fixed part for scan command */ scan_cmd = kzalloc(MAX_SCAN_CFG_ALLOC, GFP_KERNEL); if (scan_cmd == NULL) goto out; tlv = scan_cmd->tlvbuffer; /* TODO: do we need to scan for a specific BSSID? memcpy(scan_cmd->bssid, priv->scan_bssid, ETH_ALEN); */ scan_cmd->bsstype = bsstype; /* add TLVs */ if (priv->scan_ssid_len) tlv += lbs_scan_add_ssid_tlv(priv, tlv); if (chan_list && chan_count) tlv += lbs_scan_add_chanlist_tlv(tlv, chan_list, chan_count); tlv += lbs_scan_add_rates_tlv(tlv); /* This is the final data we are about to send */ scan_cmd->hdr.size = cpu_to_le16(tlv - (uint8_t *)scan_cmd); lbs_deb_hex(LBS_DEB_SCAN, "SCAN_CMD", (void *)scan_cmd, sizeof(*scan_cmd)); lbs_deb_hex(LBS_DEB_SCAN, "SCAN_TLV", scan_cmd->tlvbuffer, tlv - scan_cmd->tlvbuffer); ret = __lbs_cmd(priv, CMD_802_11_SCAN, &scan_cmd->hdr, le16_to_cpu(scan_cmd->hdr.size), lbs_ret_80211_scan, 0); out: kfree(scan_cmd); lbs_deb_leave_args(LBS_DEB_SCAN, "ret %d", ret); return ret; } /** * @brief Internal function used to start a scan based on an input config * * Also used from debugfs * * Use the input user scan configuration information when provided in * order to send the appropriate scan commands to firmware to populate or * update the internal driver scan table * * @param priv A pointer to struct lbs_private structure * @param full_scan Do a full-scan (blocking) * * @return 0 or < 0 if error */ static int lbs_scan_networks(struct lbs_private *priv, int full_scan) { int ret = -ENOMEM; struct chanscanparamset *chan_list; struct chanscanparamset *curr_chans; int chan_count; uint8_t bsstype = CMD_BSS_TYPE_ANY; int numchannels = MRVDRV_CHANNELS_PER_SCAN_CMD; union iwreq_data wrqu; #ifdef CONFIG_LIBERTAS_DEBUG struct bss_descriptor *iter; int i = 0; DECLARE_MAC_BUF(mac); #endif lbs_deb_enter_args(LBS_DEB_SCAN, "full_scan %d", full_scan); /* Cancel any partial outstanding partial scans if this scan * is a full scan. */ if (full_scan && delayed_work_pending(&priv->scan_work)) cancel_delayed_work(&priv->scan_work); /* User-specified bsstype or channel list TODO: this can be implemented if some user-space application need the feature. Formerly, it was accessible from debugfs, but then nowhere used. if (user_cfg) { if (user_cfg->bsstype) bsstype = user_cfg->bsstype; } */ lbs_deb_scan("numchannels %d, bsstype %d\n", numchannels, bsstype); /* Create list of channels to scan */ chan_list = kzalloc(sizeof(struct chanscanparamset) * LBS_IOCTL_USER_SCAN_CHAN_MAX, GFP_KERNEL); if (!chan_list) { lbs_pr_alert("SCAN: chan_list empty\n"); goto out; } /* We want to scan all channels */ chan_count = lbs_scan_create_channel_list(priv, chan_list); netif_stop_queue(priv->dev); netif_carrier_off(priv->dev); if (priv->mesh_dev) { netif_stop_queue(priv->mesh_dev); netif_carrier_off(priv->mesh_dev); } /* Prepare to continue an interrupted scan */ lbs_deb_scan("chan_count %d, scan_channel %d\n", chan_count, priv->scan_channel); curr_chans = chan_list; /* advance channel list by already-scanned-channels */ if (priv->scan_channel > 0) { curr_chans += priv->scan_channel; chan_count -= priv->scan_channel; } /* Send scan command(s) * numchannels contains the number of channels we should maximally scan * chan_count is the total number of channels to scan */ while (chan_count) { int to_scan = min(numchannels, chan_count); lbs_deb_scan("scanning %d of %d channels\n", to_scan, chan_count); ret = lbs_do_scan(priv, bsstype, curr_chans, to_scan); if (ret) { lbs_pr_err("SCAN_CMD failed\n"); goto out2; } curr_chans += to_scan; chan_count -= to_scan; /* somehow schedule the next part of the scan */ if (chan_count && !full_scan && !priv->surpriseremoved) { /* -1 marks just that we're currently scanning */ if (priv->scan_channel < 0) priv->scan_channel = to_scan; else priv->scan_channel += to_scan; cancel_delayed_work(&priv->scan_work); queue_delayed_work(priv->work_thread, &priv->scan_work, msecs_to_jiffies(300)); /* skip over GIWSCAN event */ goto out; } } memset(&wrqu, 0, sizeof(union iwreq_data)); wireless_send_event(priv->dev, SIOCGIWSCAN, &wrqu, NULL); #ifdef CONFIG_LIBERTAS_DEBUG /* Dump the scan table */ mutex_lock(&priv->lock); lbs_deb_scan("scan table:\n"); list_for_each_entry(iter, &priv->network_list, list) lbs_deb_scan("%02d: BSSID %s, RSSI %d, SSID '%s'\n", i++, print_mac(mac, iter->bssid), iter->rssi, escape_essid(iter->ssid, iter->ssid_len)); mutex_unlock(&priv->lock); #endif out2: priv->scan_channel = 0; out: if (priv->connect_status == LBS_CONNECTED) { netif_carrier_on(priv->dev); if (!priv->tx_pending_len) netif_wake_queue(priv->dev); } if (priv->mesh_dev && (priv->mesh_connect_status == LBS_CONNECTED)) { netif_carrier_on(priv->mesh_dev); if (!priv->tx_pending_len) netif_wake_queue(priv->mesh_dev); } kfree(chan_list); lbs_deb_leave_args(LBS_DEB_SCAN, "ret %d", ret); return ret; } void lbs_scan_worker(struct work_struct *work) { struct lbs_private *priv = container_of(work, struct lbs_private, scan_work.work); lbs_deb_enter(LBS_DEB_SCAN); lbs_scan_networks(priv, 0); lbs_deb_leave(LBS_DEB_SCAN); } /*********************************************************************/ /* */ /* Result interpretation */ /* */ /*********************************************************************/ /** * @brief Interpret a BSS scan response returned from the firmware * * Parse the various fixed fields and IEs passed back for a a BSS probe * response or beacon from the scan command. Record information as needed * in the scan table struct bss_descriptor for that entry. * * @param bss Output parameter: Pointer to the BSS Entry * * @return 0 or -1 */ static int lbs_process_bss(struct bss_descriptor *bss, uint8_t **pbeaconinfo, int *bytesleft) { struct ieeetypes_fhparamset *pFH; struct ieeetypes_dsparamset *pDS; struct ieeetypes_cfparamset *pCF; struct ieeetypes_ibssparamset *pibss; DECLARE_MAC_BUF(mac); struct ieeetypes_countryinfoset *pcountryinfo; uint8_t *pos, *end, *p; uint8_t n_ex_rates = 0, got_basic_rates = 0, n_basic_rates = 0; uint16_t beaconsize = 0; int ret; lbs_deb_enter(LBS_DEB_SCAN); if (*bytesleft >= sizeof(beaconsize)) { /* Extract & convert beacon size from the command buffer */ beaconsize = le16_to_cpu(get_unaligned((__le16 *)*pbeaconinfo)); *bytesleft -= sizeof(beaconsize); *pbeaconinfo += sizeof(beaconsize); } if (beaconsize == 0 || beaconsize > *bytesleft) { *pbeaconinfo += *bytesleft; *bytesleft = 0; ret = -1; goto done; } /* Initialize the current working beacon pointer for this BSS iteration */ pos = *pbeaconinfo; end = pos + beaconsize; /* Advance the return beacon pointer past the current beacon */ *pbeaconinfo += beaconsize; *bytesleft -= beaconsize; memcpy(bss->bssid, pos, ETH_ALEN); lbs_deb_scan("process_bss: BSSID %s\n", print_mac(mac, bss->bssid)); pos += ETH_ALEN; if ((end - pos) < 12) { lbs_deb_scan("process_bss: Not enough bytes left\n"); ret = -1; goto done; } /* * next 4 fields are RSSI, time stamp, beacon interval, * and capability information */ /* RSSI is 1 byte long */ bss->rssi = *pos; lbs_deb_scan("process_bss: RSSI %d\n", *pos); pos++; /* time stamp is 8 bytes long */ pos += 8; /* beacon interval is 2 bytes long */ bss->beaconperiod = le16_to_cpup((void *) pos); pos += 2; /* capability information is 2 bytes long */ bss->capability = le16_to_cpup((void *) pos); lbs_deb_scan("process_bss: capabilities 0x%04x\n", bss->capability); pos += 2; if (bss->capability & WLAN_CAPABILITY_PRIVACY) lbs_deb_scan("process_bss: WEP enabled\n"); if (bss->capability & WLAN_CAPABILITY_IBSS) bss->mode = IW_MODE_ADHOC; else bss->mode = IW_MODE_INFRA; /* rest of the current buffer are IE's */ lbs_deb_scan("process_bss: IE len %zd\n", end - pos); lbs_deb_hex(LBS_DEB_SCAN, "process_bss: IE info", pos, end - pos); /* process variable IE */ while (pos <= end - 2) { struct ieee80211_info_element * elem = (void *)pos; if (pos + elem->len > end) { lbs_deb_scan("process_bss: error in processing IE, " "bytes left < IE length\n"); break; } switch (elem->id) { case MFIE_TYPE_SSID: bss->ssid_len = elem->len; memcpy(bss->ssid, elem->data, elem->len); lbs_deb_scan("got SSID IE: '%s', len %u\n", escape_essid(bss->ssid, bss->ssid_len), bss->ssid_len); break; case MFIE_TYPE_RATES: n_basic_rates = min_t(uint8_t, MAX_RATES, elem->len); memcpy(bss->rates, elem->data, n_basic_rates); got_basic_rates = 1; lbs_deb_scan("got RATES IE\n"); break; case MFIE_TYPE_FH_SET: pFH = (struct ieeetypes_fhparamset *) pos; memmove(&bss->phyparamset.fhparamset, pFH, sizeof(struct ieeetypes_fhparamset)); lbs_deb_scan("got FH IE\n"); break; case MFIE_TYPE_DS_SET: pDS = (struct ieeetypes_dsparamset *) pos; bss->channel = pDS->currentchan; memcpy(&bss->phyparamset.dsparamset, pDS, sizeof(struct ieeetypes_dsparamset)); lbs_deb_scan("got DS IE, channel %d\n", bss->channel); break; case MFIE_TYPE_CF_SET: pCF = (struct ieeetypes_cfparamset *) pos; memcpy(&bss->ssparamset.cfparamset, pCF, sizeof(struct ieeetypes_cfparamset)); lbs_deb_scan("got CF IE\n"); break; case MFIE_TYPE_IBSS_SET: pibss = (struct ieeetypes_ibssparamset *) pos; bss->atimwindow = le16_to_cpu(pibss->atimwindow); memmove(&bss->ssparamset.ibssparamset, pibss, sizeof(struct ieeetypes_ibssparamset)); lbs_deb_scan("got IBSS IE\n"); break; case MFIE_TYPE_COUNTRY: pcountryinfo = (struct ieeetypes_countryinfoset *) pos; lbs_deb_scan("got COUNTRY IE\n"); if (pcountryinfo->len < sizeof(pcountryinfo->countrycode) || pcountryinfo->len > 254) { lbs_deb_scan("process_bss: 11D- Err CountryInfo len %d, min %zd, max 254\n", pcountryinfo->len, sizeof(pcountryinfo->countrycode)); ret = -1; goto done; } memcpy(&bss->countryinfo, pcountryinfo, pcountryinfo->len + 2); lbs_deb_hex(LBS_DEB_SCAN, "process_bss: 11d countryinfo", (uint8_t *) pcountryinfo, (int) (pcountryinfo->len + 2)); break; case MFIE_TYPE_RATES_EX: /* only process extended supported rate if data rate is * already found. Data rate IE should come before * extended supported rate IE */ lbs_deb_scan("got RATESEX IE\n"); if (!got_basic_rates) { lbs_deb_scan("... but ignoring it\n"); break; } n_ex_rates = elem->len; if (n_basic_rates + n_ex_rates > MAX_RATES) n_ex_rates = MAX_RATES - n_basic_rates; p = bss->rates + n_basic_rates; memcpy(p, elem->data, n_ex_rates); break; case MFIE_TYPE_GENERIC: if (elem->len >= 4 && elem->data[0] == 0x00 && elem->data[1] == 0x50 && elem->data[2] == 0xf2 && elem->data[3] == 0x01) { bss->wpa_ie_len = min(elem->len + 2, MAX_WPA_IE_LEN); memcpy(bss->wpa_ie, elem, bss->wpa_ie_len); lbs_deb_scan("got WPA IE\n"); lbs_deb_hex(LBS_DEB_SCAN, "WPA IE", bss->wpa_ie, elem->len); } else if (elem->len >= MARVELL_MESH_IE_LENGTH && elem->data[0] == 0x00 && elem->data[1] == 0x50 && elem->data[2] == 0x43 && elem->data[3] == 0x04) { lbs_deb_scan("got mesh IE\n"); bss->mesh = 1; } else { lbs_deb_scan("got generic IE: %02x:%02x:%02x:%02x, len %d\n", elem->data[0], elem->data[1], elem->data[2], elem->data[3], elem->len); } break; case MFIE_TYPE_RSN: lbs_deb_scan("got RSN IE\n"); bss->rsn_ie_len = min(elem->len + 2, MAX_WPA_IE_LEN); memcpy(bss->rsn_ie, elem, bss->rsn_ie_len); lbs_deb_hex(LBS_DEB_SCAN, "process_bss: RSN_IE", bss->rsn_ie, elem->len); break; default: lbs_deb_scan("got IE 0x%04x, len %d\n", elem->id, elem->len); break; } pos += elem->len + 2; } /* Timestamp */ bss->last_scanned = jiffies; lbs_unset_basic_rate_flags(bss->rates, sizeof(bss->rates)); ret = 0; done: lbs_deb_leave_args(LBS_DEB_SCAN, "ret %d", ret); return ret; } /** * @brief This function finds a specific compatible BSSID in the scan list * * Used in association code * * @param priv A pointer to struct lbs_private * @param bssid BSSID to find in the scan list * @param mode Network mode: Infrastructure or IBSS * * @return index in BSSID list, or error return code (< 0) */ struct bss_descriptor *lbs_find_bssid_in_list(struct lbs_private *priv, uint8_t *bssid, uint8_t mode) { struct bss_descriptor *iter_bss; struct bss_descriptor *found_bss = NULL; lbs_deb_enter(LBS_DEB_SCAN); if (!bssid) goto out; lbs_deb_hex(LBS_DEB_SCAN, "looking for", bssid, ETH_ALEN); /* Look through the scan table for a compatible match. The loop will * continue past a matched bssid that is not compatible in case there * is an AP with multiple SSIDs assigned to the same BSSID */ mutex_lock(&priv->lock); list_for_each_entry (iter_bss, &priv->network_list, list) { if (compare_ether_addr(iter_bss->bssid, bssid)) continue; /* bssid doesn't match */ switch (mode) { case IW_MODE_INFRA: case IW_MODE_ADHOC: if (!is_network_compatible(priv, iter_bss, mode)) break; found_bss = iter_bss; break; default: found_bss = iter_bss; break; } } mutex_unlock(&priv->lock); out: lbs_deb_leave_args(LBS_DEB_SCAN, "found_bss %p", found_bss); return found_bss; } /** * @brief This function finds ssid in ssid list. * * Used in association code * * @param priv A pointer to struct lbs_private * @param ssid SSID to find in the list * @param bssid BSSID to qualify the SSID selection (if provided) * @param mode Network mode: Infrastructure or IBSS * * @return index in BSSID list */ struct bss_descriptor *lbs_find_ssid_in_list(struct lbs_private *priv, uint8_t *ssid, uint8_t ssid_len, uint8_t *bssid, uint8_t mode, int channel) { u32 bestrssi = 0; struct bss_descriptor * iter_bss = NULL; struct bss_descriptor * found_bss = NULL; struct bss_descriptor * tmp_oldest = NULL; lbs_deb_enter(LBS_DEB_SCAN); mutex_lock(&priv->lock); list_for_each_entry (iter_bss, &priv->network_list, list) { if ( !tmp_oldest || (iter_bss->last_scanned < tmp_oldest->last_scanned)) tmp_oldest = iter_bss; if (lbs_ssid_cmp(iter_bss->ssid, iter_bss->ssid_len, ssid, ssid_len) != 0) continue; /* ssid doesn't match */ if (bssid && compare_ether_addr(iter_bss->bssid, bssid) != 0) continue; /* bssid doesn't match */ if ((channel > 0) && (iter_bss->channel != channel)) continue; /* channel doesn't match */ switch (mode) { case IW_MODE_INFRA: case IW_MODE_ADHOC: if (!is_network_compatible(priv, iter_bss, mode)) break; if (bssid) { /* Found requested BSSID */ found_bss = iter_bss; goto out; } if (SCAN_RSSI(iter_bss->rssi) > bestrssi) { bestrssi = SCAN_RSSI(iter_bss->rssi); found_bss = iter_bss; } break; case IW_MODE_AUTO: default: if (SCAN_RSSI(iter_bss->rssi) > bestrssi) { bestrssi = SCAN_RSSI(iter_bss->rssi); found_bss = iter_bss; } break; } } out: mutex_unlock(&priv->lock); lbs_deb_leave_args(LBS_DEB_SCAN, "found_bss %p", found_bss); return found_bss; } /** * @brief This function finds the best SSID in the Scan List * * Search the scan table for the best SSID that also matches the current * adapter network preference (infrastructure or adhoc) * * @param priv A pointer to struct lbs_private * * @return index in BSSID list */ static struct bss_descriptor *lbs_find_best_ssid_in_list(struct lbs_private *priv, uint8_t mode) { uint8_t bestrssi = 0; struct bss_descriptor *iter_bss; struct bss_descriptor *best_bss = NULL; lbs_deb_enter(LBS_DEB_SCAN); mutex_lock(&priv->lock); list_for_each_entry (iter_bss, &priv->network_list, list) { switch (mode) { case IW_MODE_INFRA: case IW_MODE_ADHOC: if (!is_network_compatible(priv, iter_bss, mode)) break; if (SCAN_RSSI(iter_bss->rssi) <= bestrssi) break; bestrssi = SCAN_RSSI(iter_bss->rssi); best_bss = iter_bss; break; case IW_MODE_AUTO: default: if (SCAN_RSSI(iter_bss->rssi) <= bestrssi) break; bestrssi = SCAN_RSSI(iter_bss->rssi); best_bss = iter_bss; break; } } mutex_unlock(&priv->lock); lbs_deb_leave_args(LBS_DEB_SCAN, "best_bss %p", best_bss); return best_bss; } /** * @brief Find the best AP * * Used from association worker. * * @param priv A pointer to struct lbs_private structure * @param pSSID A pointer to AP's ssid * * @return 0--success, otherwise--fail */ int lbs_find_best_network_ssid(struct lbs_private *priv, uint8_t *out_ssid, uint8_t *out_ssid_len, uint8_t preferred_mode, uint8_t *out_mode) { int ret = -1; struct bss_descriptor *found; lbs_deb_enter(LBS_DEB_SCAN); priv->scan_ssid_len = 0; lbs_scan_networks(priv, 1); if (priv->surpriseremoved) goto out; found = lbs_find_best_ssid_in_list(priv, preferred_mode); if (found && (found->ssid_len > 0)) { memcpy(out_ssid, &found->ssid, IW_ESSID_MAX_SIZE); *out_ssid_len = found->ssid_len; *out_mode = found->mode; ret = 0; } out: lbs_deb_leave_args(LBS_DEB_SCAN, "ret %d", ret); return ret; } /** * @brief Send a scan command for all available channels filtered on a spec * * Used in association code and from debugfs * * @param priv A pointer to struct lbs_private structure * @param ssid A pointer to the SSID to scan for * @param ssid_len Length of the SSID * * @return 0-success, otherwise fail */ int lbs_send_specific_ssid_scan(struct lbs_private *priv, uint8_t *ssid, uint8_t ssid_len) { int ret = 0; lbs_deb_enter_args(LBS_DEB_SCAN, "SSID '%s'\n", escape_essid(ssid, ssid_len)); if (!ssid_len) goto out; memcpy(priv->scan_ssid, ssid, ssid_len); priv->scan_ssid_len = ssid_len; lbs_scan_networks(priv, 1); if (priv->surpriseremoved) { ret = -1; goto out; } out: lbs_deb_leave_args(LBS_DEB_SCAN, "ret %d", ret); return ret; } /*********************************************************************/ /* */ /* Support for Wireless Extensions */ /* */ /*********************************************************************/ #define MAX_CUSTOM_LEN 64 static inline char *lbs_translate_scan(struct lbs_private *priv, char *start, char *stop, struct bss_descriptor *bss) { struct chan_freq_power *cfp; char *current_val; /* For rates */ struct iw_event iwe; /* Temporary buffer */ int j; #define PERFECT_RSSI ((uint8_t)50) #define WORST_RSSI ((uint8_t)0) #define RSSI_DIFF ((uint8_t)(PERFECT_RSSI - WORST_RSSI)) uint8_t rssi; lbs_deb_enter(LBS_DEB_SCAN); cfp = lbs_find_cfp_by_band_and_channel(priv, 0, bss->channel); if (!cfp) { lbs_deb_scan("Invalid channel number %d\n", bss->channel); start = NULL; goto out; } /* First entry *MUST* be the BSSID */ iwe.cmd = SIOCGIWAP; iwe.u.ap_addr.sa_family = ARPHRD_ETHER; memcpy(iwe.u.ap_addr.sa_data, &bss->bssid, ETH_ALEN); start = iwe_stream_add_event(start, stop, &iwe, IW_EV_ADDR_LEN); /* SSID */ iwe.cmd = SIOCGIWESSID; iwe.u.data.flags = 1; iwe.u.data.length = min((uint32_t) bss->ssid_len, (uint32_t) IW_ESSID_MAX_SIZE); start = iwe_stream_add_point(start, stop, &iwe, bss->ssid); /* Mode */ iwe.cmd = SIOCGIWMODE; iwe.u.mode = bss->mode; start = iwe_stream_add_event(start, stop, &iwe, IW_EV_UINT_LEN); /* Frequency */ iwe.cmd = SIOCGIWFREQ; iwe.u.freq.m = (long)cfp->freq * 100000; iwe.u.freq.e = 1; start = iwe_stream_add_event(start, stop, &iwe, IW_EV_FREQ_LEN); /* Add quality statistics */ iwe.cmd = IWEVQUAL; iwe.u.qual.updated = IW_QUAL_ALL_UPDATED; iwe.u.qual.level = SCAN_RSSI(bss->rssi); rssi = iwe.u.qual.level - MRVDRV_NF_DEFAULT_SCAN_VALUE; iwe.u.qual.qual = (100 * RSSI_DIFF * RSSI_DIFF - (PERFECT_RSSI - rssi) * (15 * (RSSI_DIFF) + 62 * (PERFECT_RSSI - rssi))) / (RSSI_DIFF * RSSI_DIFF); if (iwe.u.qual.qual > 100) iwe.u.qual.qual = 100; if (priv->NF[TYPE_BEACON][TYPE_NOAVG] == 0) { iwe.u.qual.noise = MRVDRV_NF_DEFAULT_SCAN_VALUE; } else { iwe.u.qual.noise = CAL_NF(priv->NF[TYPE_BEACON][TYPE_NOAVG]); } /* Locally created ad-hoc BSSs won't have beacons if this is the * only station in the adhoc network; so get signal strength * from receive statistics. */ if ((priv->mode == IW_MODE_ADHOC) && priv->adhoccreate && !lbs_ssid_cmp(priv->curbssparams.ssid, priv->curbssparams.ssid_len, bss->ssid, bss->ssid_len)) { int snr, nf; snr = priv->SNR[TYPE_RXPD][TYPE_AVG] / AVG_SCALE; nf = priv->NF[TYPE_RXPD][TYPE_AVG] / AVG_SCALE; iwe.u.qual.level = CAL_RSSI(snr, nf); } start = iwe_stream_add_event(start, stop, &iwe, IW_EV_QUAL_LEN); /* Add encryption capability */ iwe.cmd = SIOCGIWENCODE; if (bss->capability & WLAN_CAPABILITY_PRIVACY) { iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY; } else { iwe.u.data.flags = IW_ENCODE_DISABLED; } iwe.u.data.length = 0; start = iwe_stream_add_point(start, stop, &iwe, bss->ssid); current_val = start + IW_EV_LCP_LEN; iwe.cmd = SIOCGIWRATE; iwe.u.bitrate.fixed = 0; iwe.u.bitrate.disabled = 0; iwe.u.bitrate.value = 0; for (j = 0; bss->rates[j] && (j < sizeof(bss->rates)); j++) { /* Bit rate given in 500 kb/s units */ iwe.u.bitrate.value = bss->rates[j] * 500000; current_val = iwe_stream_add_value(start, current_val, stop, &iwe, IW_EV_PARAM_LEN); } if ((bss->mode == IW_MODE_ADHOC) && priv->adhoccreate && !lbs_ssid_cmp(priv->curbssparams.ssid, priv->curbssparams.ssid_len, bss->ssid, bss->ssid_len)) { iwe.u.bitrate.value = 22 * 500000; current_val = iwe_stream_add_value(start, current_val, stop, &iwe, IW_EV_PARAM_LEN); } /* Check if we added any event */ if((current_val - start) > IW_EV_LCP_LEN) start = current_val; memset(&iwe, 0, sizeof(iwe)); if (bss->wpa_ie_len) { char buf[MAX_WPA_IE_LEN]; memcpy(buf, bss->wpa_ie, bss->wpa_ie_len); iwe.cmd = IWEVGENIE; iwe.u.data.length = bss->wpa_ie_len; start = iwe_stream_add_point(start, stop, &iwe, buf); } memset(&iwe, 0, sizeof(iwe)); if (bss->rsn_ie_len) { char buf[MAX_WPA_IE_LEN]; memcpy(buf, bss->rsn_ie, bss->rsn_ie_len); iwe.cmd = IWEVGENIE; iwe.u.data.length = bss->rsn_ie_len; start = iwe_stream_add_point(start, stop, &iwe, buf); } if (bss->mesh) { char custom[MAX_CUSTOM_LEN]; char *p = custom; iwe.cmd = IWEVCUSTOM; p += snprintf(p, MAX_CUSTOM_LEN, "mesh-type: olpc"); iwe.u.data.length = p - custom; if (iwe.u.data.length) start = iwe_stream_add_point(start, stop, &iwe, custom); } out: lbs_deb_leave_args(LBS_DEB_SCAN, "start %p", start); return start; } /** * @brief Handle Scan Network ioctl * * @param dev A pointer to net_device structure * @param info A pointer to iw_request_info structure * @param vwrq A pointer to iw_param structure * @param extra A pointer to extra data buf * * @return 0 --success, otherwise fail */ int lbs_set_scan(struct net_device *dev, struct iw_request_info *info, union iwreq_data *wrqu, char *extra) { struct lbs_private *priv = dev->priv; int ret = 0; lbs_deb_enter(LBS_DEB_WEXT); if (!netif_running(dev)) { ret = -ENETDOWN; goto out; } /* mac80211 does this: struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev); if (sdata->type != IEEE80211_IF_TYPE_xxx) { ret = -EOPNOTSUPP; goto out; } */ if (wrqu->data.length == sizeof(struct iw_scan_req) && wrqu->data.flags & IW_SCAN_THIS_ESSID) { struct iw_scan_req *req = (struct iw_scan_req *)extra; priv->scan_ssid_len = req->essid_len; memcpy(priv->scan_ssid, req->essid, priv->scan_ssid_len); lbs_deb_wext("set_scan, essid '%s'\n", escape_essid(priv->scan_ssid, priv->scan_ssid_len)); } else { priv->scan_ssid_len = 0; } if (!delayed_work_pending(&priv->scan_work)) queue_delayed_work(priv->work_thread, &priv->scan_work, msecs_to_jiffies(50)); /* set marker that currently a scan is taking place */ priv->scan_channel = -1; if (priv->surpriseremoved) ret = -EIO; out: lbs_deb_leave_args(LBS_DEB_WEXT, "ret %d", ret); return ret; } /** * @brief Handle Retrieve scan table ioctl * * @param dev A pointer to net_device structure * @param info A pointer to iw_request_info structure * @param dwrq A pointer to iw_point structure * @param extra A pointer to extra data buf * * @return 0 --success, otherwise fail */ int lbs_get_scan(struct net_device *dev, struct iw_request_info *info, struct iw_point *dwrq, char *extra) { #define SCAN_ITEM_SIZE 128 struct lbs_private *priv = dev->priv; int err = 0; char *ev = extra; char *stop = ev + dwrq->length; struct bss_descriptor *iter_bss; struct bss_descriptor *safe; lbs_deb_enter(LBS_DEB_WEXT); /* iwlist should wait until the current scan is finished */ if (priv->scan_channel) return -EAGAIN; /* Update RSSI if current BSS is a locally created ad-hoc BSS */ if ((priv->mode == IW_MODE_ADHOC) && priv->adhoccreate) lbs_prepare_and_send_command(priv, CMD_802_11_RSSI, 0, CMD_OPTION_WAITFORRSP, 0, NULL); mutex_lock(&priv->lock); list_for_each_entry_safe (iter_bss, safe, &priv->network_list, list) { char *next_ev; unsigned long stale_time; if (stop - ev < SCAN_ITEM_SIZE) { err = -E2BIG; break; } /* For mesh device, list only mesh networks */ if (dev == priv->mesh_dev && !iter_bss->mesh) continue; /* Prune old an old scan result */ stale_time = iter_bss->last_scanned + DEFAULT_MAX_SCAN_AGE; if (time_after(jiffies, stale_time)) { list_move_tail(&iter_bss->list, &priv->network_free_list); clear_bss_descriptor(iter_bss); continue; } /* Translate to WE format this entry */ next_ev = lbs_translate_scan(priv, ev, stop, iter_bss); if (next_ev == NULL) continue; ev = next_ev; } mutex_unlock(&priv->lock); dwrq->length = (ev - extra); dwrq->flags = 0; lbs_deb_leave_args(LBS_DEB_WEXT, "ret %d", err); return err; } /*********************************************************************/ /* */ /* Command execution */ /* */ /*********************************************************************/ /** * @brief This function handles the command response of scan * * Called from handle_cmd_response() in cmdrespc. * * The response buffer for the scan command has the following * memory layout: * * .-----------------------------------------------------------. * | header (4 * sizeof(u16)): Standard command response hdr | * .-----------------------------------------------------------. * | bufsize (u16) : sizeof the BSS Description data | * .-----------------------------------------------------------. * | NumOfSet (u8) : Number of BSS Descs returned | * .-----------------------------------------------------------. * | BSSDescription data (variable, size given in bufsize) | * .-----------------------------------------------------------. * | TLV data (variable, size calculated using header->size, | * | bufsize and sizeof the fixed fields above) | * .-----------------------------------------------------------. * * @param priv A pointer to struct lbs_private structure * @param resp A pointer to cmd_ds_command * * @return 0 or -1 */ static int lbs_ret_80211_scan(struct lbs_private *priv, unsigned long dummy, struct cmd_header *resp) { struct cmd_ds_802_11_scan_rsp *scanresp = (void *)resp; struct bss_descriptor *iter_bss; struct bss_descriptor *safe; uint8_t *bssinfo; uint16_t scanrespsize; int bytesleft; int idx; int tlvbufsize; int ret; lbs_deb_enter(LBS_DEB_SCAN); /* Prune old entries from scan table */ list_for_each_entry_safe (iter_bss, safe, &priv->network_list, list) { unsigned long stale_time = iter_bss->last_scanned + DEFAULT_MAX_SCAN_AGE; if (time_before(jiffies, stale_time)) continue; list_move_tail (&iter_bss->list, &priv->network_free_list); clear_bss_descriptor(iter_bss); } if (scanresp->nr_sets > MAX_NETWORK_COUNT) { lbs_deb_scan("SCAN_RESP: too many scan results (%d, max %d)\n", scanresp->nr_sets, MAX_NETWORK_COUNT); ret = -1; goto done; } bytesleft = le16_to_cpu(scanresp->bssdescriptsize); lbs_deb_scan("SCAN_RESP: bssdescriptsize %d\n", bytesleft); scanrespsize = le16_to_cpu(resp->size); lbs_deb_scan("SCAN_RESP: scan results %d\n", scanresp->nr_sets); bssinfo = scanresp->bssdesc_and_tlvbuffer; /* The size of the TLV buffer is equal to the entire command response * size (scanrespsize) minus the fixed fields (sizeof()'s), the * BSS Descriptions (bssdescriptsize as bytesLef) and the command * response header (S_DS_GEN) */ tlvbufsize = scanrespsize - (bytesleft + sizeof(scanresp->bssdescriptsize) + sizeof(scanresp->nr_sets) + S_DS_GEN); /* * Process each scan response returned (scanresp->nr_sets). Save * the information in the newbssentry and then insert into the * driver scan table either as an update to an existing entry * or as an addition at the end of the table */ for (idx = 0; idx < scanresp->nr_sets && bytesleft; idx++) { struct bss_descriptor new; struct bss_descriptor *found = NULL; struct bss_descriptor *oldest = NULL; DECLARE_MAC_BUF(mac); /* Process the data fields and IEs returned for this BSS */ memset(&new, 0, sizeof (struct bss_descriptor)); if (lbs_process_bss(&new, &bssinfo, &bytesleft) != 0) { /* error parsing the scan response, skipped */ lbs_deb_scan("SCAN_RESP: process_bss returned ERROR\n"); continue; } /* Try to find this bss in the scan table */ list_for_each_entry (iter_bss, &priv->network_list, list) { if (is_same_network(iter_bss, &new)) { found = iter_bss; break; } if ((oldest == NULL) || (iter_bss->last_scanned < oldest->last_scanned)) oldest = iter_bss; } if (found) { /* found, clear it */ clear_bss_descriptor(found); } else if (!list_empty(&priv->network_free_list)) { /* Pull one from the free list */ found = list_entry(priv->network_free_list.next, struct bss_descriptor, list); list_move_tail(&found->list, &priv->network_list); } else if (oldest) { /* If there are no more slots, expire the oldest */ found = oldest; clear_bss_descriptor(found); list_move_tail(&found->list, &priv->network_list); } else { continue; } lbs_deb_scan("SCAN_RESP: BSSID %s\n", print_mac(mac, new.bssid)); /* Copy the locally created newbssentry to the scan table */ memcpy(found, &new, offsetof(struct bss_descriptor, list)); } ret = 0; done: lbs_deb_leave_args(LBS_DEB_SCAN, "ret %d", ret); return ret; }