wordpress 中文图片不显示,北京网站优化公司哪家好,工作证明,简述企业网络建设的步骤本文主要介绍external/wpa_supplicant_8/src/p2p/p2p.c文件
先看下p2p_find 这个方法
P2P_find 主要用于 P2P#xff08;点对点#xff09;网络中查找其他对等方的功能。另外可以看到设置P2P模块的状态为 P2P_SEARCH
int p2p_find(struct p2p_data *p2p, unsigned int tim…本文主要介绍external/wpa_supplicant_8/src/p2p/p2p.c文件
先看下p2p_find 这个方法
P2P_find 主要用于 P2P点对点网络中查找其他对等方的功能。另外可以看到设置P2P模块的状态为 P2P_SEARCH
int p2p_find(struct p2p_data *p2p, unsigned int timeout,enum p2p_discovery_type type,unsigned int num_req_dev_types, const u8 *req_dev_types,const u8 *dev_id, unsigned int search_delay,u8 seek_count, const char **seek, int freq, bool include_6ghz)
{int res;struct os_reltime start;p2p_dbg(p2p, Starting find (type%d), type);//确认P2P扫描已经可以使用if (p2p-p2p_scan_running) {p2p_dbg(p2p, p2p_scan is already running);}p2p_free_req_dev_types(p2p);if (req_dev_types num_req_dev_types) {p2p-req_dev_types os_memdup(req_dev_types,num_req_dev_types *WPS_DEV_TYPE_LEN);if (p2p-req_dev_types NULL)return -1;p2p-num_req_dev_types num_req_dev_types;}if (dev_id) {os_memcpy(p2p-find_dev_id_buf, dev_id, ETH_ALEN);p2p-find_dev_id p2p-find_dev_id_buf;} elsep2p-find_dev_id NULL;p2p-include_6ghz p2p_wfd_enabled(p2p) include_6ghz;if (seek_count 0 || !seek) {/* Not an ASP search */p2p-p2ps_seek 0;} else if (seek_count 1 seek (!seek[0] || !seek[0][0])) {/** An empty seek string means no hash values, but still an ASP* search.*/p2p_dbg(p2p, ASP search);p2p-p2ps_seek_count 0;p2p-p2ps_seek 1;} else if (seek seek_count P2P_MAX_QUERY_HASH) {u8 buf[P2PS_HASH_LEN];int i, count 0;for (i 0; i seek_count; i) {if (!p2ps_gen_hash(p2p, seek[i], buf))continue;p2p_dbg(p2p, Seek service %s hash MACSTR,seek[i], MAC2STR(buf));os_memcpy(p2p-p2ps_seek_hash[count * P2PS_HASH_LEN],buf, P2PS_HASH_LEN);count;}p2p-p2ps_seek_count count;p2p-p2ps_seek 1;} else {p2p-p2ps_seek_count 0;p2p-p2ps_seek 1;}/* Special case to perform wildcard search */if (p2p-p2ps_seek_count 0 p2p-p2ps_seek) {p2p-p2ps_seek_count 1;os_memcpy(p2p-p2ps_seek_hash, p2p-wild_card_hash,P2PS_HASH_LEN);}//P2P_AFTER_SCAN_NOTHING表示P2P设备完成scan动作后无需做其他动作p2p-start_after_scan P2P_AFTER_SCAN_NOTHING;p2p_clear_timeout(p2p);if (p2p-pending_listen_freq) {p2p_dbg(p2p, Clear pending_listen_freq for p2p_find);p2p-pending_listen_freq 0;}//停止监听p2p-cfg-stop_listen(p2p-cfg-cb_ctx);p2p-find_pending_full 0;p2p-find_type type;if (freq ! 2412 freq ! 2437 freq ! 2462 freq ! 60480)p2p-find_specified_freq freq;elsep2p-find_specified_freq 0;p2p_device_clear_reported(p2p);os_memset(p2p-sd_query_no_ack, 0, ETH_ALEN);//设置P2P模块的状态为 P2P_SEARCHp2p_set_state(p2p, P2P_SEARCH);p2p-search_delay search_delay;p2p-in_search_delay 0;eloop_cancel_timeout(p2p_find_timeout, p2p, NULL);p2p-last_p2p_find_timeout timeout;if (timeout)//注册一个扫描超时处理任务eloop_register_timeout(timeout, 0, p2p_find_timeout,p2p, NULL);os_get_reltime(start);switch (type) {case P2P_FIND_START_WITH_FULL:if (freq 0) {/** Start with the specified channel and then move to* scans for social channels and this specific channel.*/res p2p-cfg-p2p_scan(p2p-cfg-cb_ctx,P2P_SCAN_SPECIFIC, freq,p2p-num_req_dev_types,p2p-req_dev_types, dev_id,DEV_PW_DEFAULT,p2p-include_6ghz);break;}/* fall through */case P2P_FIND_PROGRESSIVE: //p2p_scan指向函数 wpas_p2p_scanres p2p-cfg-p2p_scan(p2p-cfg-cb_ctx, P2P_SCAN_FULL, 0,p2p-num_req_dev_types,p2p-req_dev_types, dev_id,DEV_PW_DEFAULT, p2p-include_6ghz);break;case P2P_FIND_ONLY_SOCIAL:res p2p-cfg-p2p_scan(p2p-cfg-cb_ctx, P2P_SCAN_SOCIAL, 0,p2p-num_req_dev_types,p2p-req_dev_types, dev_id,DEV_PW_DEFAULT, p2p-include_6ghz);break;default:return -1;}if (!res)p2p-find_start start;if (res ! 0 p2p-p2p_scan_running) {p2p_dbg(p2p, Failed to start p2p_scan - another p2p_scan was already running);/* wait for the previous p2p_scan to complete */if (type P2P_FIND_PROGRESSIVE ||(type P2P_FIND_START_WITH_FULL freq 0))p2p-find_pending_full 1;res 0; /* do not report failure */} else if (res ! 0) {p2p_dbg(p2p, Failed to start p2p_scan);p2p_set_state(p2p, P2P_IDLE);eloop_cancel_timeout(p2p_find_timeout, p2p, NULL);}return res;
} 接着看下P2P模块的状态为 P2P_SEARCH后如何进行进入listen状态 也就是p2p_listen_in_find这个方法
static void p2p_listen_in_find(struct p2p_data *p2p, int dev_disc)
{unsigned int r, tu;int freq;struct wpabuf *ies;p2p_dbg(p2p, Starting short listen state (state%s),p2p_state_txt(p2p-state));if (p2p-pending_listen_freq) {/* We have a pending p2p_listen request */p2p_dbg(p2p, p2p_listen command pending already);return;}//根据 p2p_supplicant.conf中listen_channel等配置参数获取对应的频段freq p2p_channel_to_freq(p2p-cfg-reg_class, p2p-cfg-channel);if (freq 0) {p2p_dbg(p2p, Unknown regulatory class/channel);return;}//计算需要在listen state 等待的时间if (os_get_random((u8 *) r, sizeof(r)) 0)r 0;tu (r % ((p2p-max_disc_int - p2p-min_disc_int) 1) p2p-min_disc_int) * 100;if (p2p-max_disc_tu 0 tu (unsigned int) p2p-max_disc_tu)tu p2p-max_disc_tu;if (!dev_disc tu 100)tu 100; /* Need to wait in non-device discovery use cases */if (p2p-cfg-max_listen 1024 * tu / 1000 p2p-cfg-max_listen)tu p2p-cfg-max_listen * 1000 / 1024;if (tu 0) {p2p_dbg(p2p, Skip listen state since duration was 0 TU);p2p_set_timeout(p2p, 0, 0);return;}//构造P2P Probe Response帧当我们在Listen state收到其他设备发来的Probe Request帧后wifi驱动将直接回复此处设置的 P2P Probe Response帧。ies p2p_build_probe_resp_ies(p2p, NULL, 0);if (ies NULL)return;p2p-pending_listen_freq freq;p2p-pending_listen_sec 0;p2p-pending_listen_usec 1024 * tu;//start_listen指向 wpas_start_listen 函数if (p2p-cfg-start_listen(p2p-cfg-cb_ctx, freq, 1024 * tu / 1000,ies) 0) {p2p_dbg(p2p, Failed to start listen mode);p2p-pending_listen_freq 0;}wpabuf_free(ies);
}
在来看p2p_connect函数其代码如下所示
这里面有3个重要的知识点
1、是 breaker值在每次发起P2P_CONNECT时都取反一次这样做的目的是在双方的Intent值相同的情况下多次协商时双方都有机会做GO。并且在发送Request时才填入自己的breaker值在回应Response时是把对方的breaker值取反后作为breaker值发送。
2. 如果当前P2P还在扫描过程中则设置start_after_scan为P2P_AFTER_SCAN_CONNECT标志当scan结束后在扫描结果处理流程中该标志将通知P2P进入connect处理流程
3. p2p_connect_send发送GON Request帧
int p2p_connect(struct p2p_data *p2p, const u8 *peer_addr,enum p2p_wps_method wps_method,int go_intent, const u8 *own_interface_addr,unsigned int force_freq, int persistent_group,const u8 *force_ssid, size_t force_ssid_len,int pd_before_go_neg, unsigned int pref_freq, u16 oob_pw_id)
{struct p2p_device *dev;p2p_dbg(p2p, Request to start group negotiation - peer MACSTR GO Intent%d Intended Interface Address MACSTR wps_method%d persistent_group%d pd_before_go_neg%d oob_pw_id%u allow_6ghz%d,MAC2STR(peer_addr), go_intent, MAC2STR(own_interface_addr),wps_method, persistent_group, pd_before_go_neg, oob_pw_id,p2p-allow_6ghz);//获取当前设备p2p dev设备的信息dev p2p_get_device(p2p, peer_addr);if (dev NULL || (dev-flags P2P_DEV_PROBE_REQ_ONLY)) {p2p_dbg(p2p, Cannot connect to unknown P2P Device MACSTR,MAC2STR(peer_addr));return -1;}// 如果指定了工作频段则需要判断是否支持该工作频段否则return -1if (p2p_prepare_channel(p2p, dev, force_freq, pref_freq,go_intent 15) 0)return -1;if (dev-flags P2P_DEV_GROUP_CLIENT_ONLY) {if (!(dev-info.dev_capab P2P_DEV_CAPAB_CLIENT_DISCOVERABILITY)) {p2p_dbg(p2p, Cannot connect to P2P Device MACSTR that is in a group and is not discoverable,MAC2STR(peer_addr));return -1;}if (dev-oper_freq 0) {p2p_dbg(p2p, Cannot connect to P2P Device MACSTR with incomplete information,MAC2STR(peer_addr));return -1;}/** First, try to connect directly. If the peer does not* acknowledge frames, assume it is sleeping and use device* discoverability via the GO at that point.*/}p2p-ssid_set 0;if (force_ssid) {wpa_hexdump_ascii(MSG_DEBUG, P2P: Forced SSID,force_ssid, force_ssid_len);os_memcpy(p2p-ssid, force_ssid, force_ssid_len);p2p-ssid_len force_ssid_len;p2p-ssid_set 1;}dev-flags ~P2P_DEV_NOT_YET_READY;dev-flags ~P2P_DEV_USER_REJECTED;dev-flags ~P2P_DEV_WAIT_GO_NEG_RESPONSE;dev-flags ~P2P_DEV_WAIT_GO_NEG_CONFIRM;if (pd_before_go_neg)dev-flags | P2P_DEV_PD_BEFORE_GO_NEG;else {dev-flags ~P2P_DEV_PD_BEFORE_GO_NEG;/** Assign dialog token and tie breaker here to use the same* values in each retry within the same GO Negotiation exchange.*/dev-dialog_token;if (dev-dialog_token 0)dev-dialog_token 1;dev-tie_breaker p2p-next_tie_breaker;p2p-next_tie_breaker !p2p-next_tie_breaker;//这里是对intent的值取反}dev-connect_reqs 0;dev-go_neg_req_sent 0;dev-go_state UNKNOWN_GO;p2p_set_dev_persistent(dev, persistent_group);p2p-go_intent go_intent;os_memcpy(p2p-intended_addr, own_interface_addr, ETH_ALEN);if (p2p-state ! P2P_IDLE)p2p_stop_find(p2p);dev-wps_method wps_method;dev-oob_pw_id oob_pw_id;dev-status P2P_SC_SUCCESS;if (p2p-p2p_scan_running) {p2p_dbg(p2p, p2p_scan running - delay connect send);
/*
如果当前P2P还在扫描过程中则设置start_after_scan为P2P_AFTER_SCAN_CONNECT标志
当scan结束后在扫描结果处理流程中该标志将通知P2P进入connect处理流程。
*/p2p-start_after_scan P2P_AFTER_SCAN_CONNECT;os_memcpy(p2p-after_scan_peer, peer_addr, ETH_ALEN);return 0;}// 下面这个函数将发送GON Request帧return p2p_connect_send(p2p, dev);
}p2p_set_state和p2p_set_timeout记录了P2P: State和Timeout
void p2p_set_state(struct p2p_data *p2p, int new_state)
{p2p_dbg(p2p, State %s - %s,p2p_state_txt(p2p-state), p2p_state_txt(new_state));p2p-state new_state;if (new_state P2P_IDLE p2p-pending_channel) {p2p_dbg(p2p, Apply change in listen channel);p2p-cfg-reg_class p2p-pending_reg_class;p2p-cfg-channel p2p-pending_channel;p2p-pending_reg_class 0;p2p-pending_channel 0;}
}void p2p_set_timeout(struct p2p_data *p2p, unsigned int sec, unsigned int usec)
{p2p_dbg(p2p, Set timeout (state%s): %u.%06u sec,p2p_state_txt(p2p-state), sec, usec);eloop_cancel_timeout(p2p_state_timeout, p2p, NULL);eloop_register_timeout(sec, usec, p2p_state_timeout, p2p, NULL);
}
