iwpriv工具通过ioctl动态获取相应无线网卡驱动的private_args所有扩展参数.docx

iwpriv工具通过ioctl动态获取相应无线网卡驱动的private_args所有扩展参数iwpriv是处理下面的wlan_private_args的所有扩展命令,iwpriv的实现上,是这样的,=main=set_private=iw_get_priv_info获取wireless网卡所能处理的所有wlan_private_args类型.dev_ioctl=wext_handle_ioctl=wireless_process_ioctlif (cmd = SIOCGIWPRIV & dev-wireless_handlers)return ioctl_standard_call(dev, ifr, cmd, &iw_handler_get_private);static int ioctl_standard_call(struct net_device *dev, struct ifreq *ifr, unsigned intcmd, iw_handlerhandler)./* Call the handler */ret = handler(dev, &info, &(iwr-u), extra);if (user_length u.data.length) kfree(extra);return -E2BIG;/通知iwpriv,本wifi网卡对应的private命令还没有完,还有,这样iwpriv将会继续/maxpriv默认为16,即将以16个为一组,一组一组的从wifi网卡驱动读取该网卡所能支持的所有private_args参数/newpriv = realloc(priv, maxpriv * sizeof(priv0);继续申请,继续拷贝,知道将wifi网卡自定义的wlan_private_args参数全部/传出到iwpriv为止./* New driver API : try to find the handler */handler = get_handler(dev, cmd);/获取if (handler) /* Standard and private are not the same */if (cmd do_ioctl完成的.return ioctl_private_call(dev, ifr, cmd, handler);/* Old driver API : call driver ioctl handler */if (dev-do_ioctl)/如果dev-wireless_handlers-standard和dev-wireless_handlers-privateindex都不对该cmd作处理,那么由/dev-do_ioctl = wlan_do_ioctl;我们驱动的最后处理函数wlan_do_ioctl处理.return dev-do_ioctl(dev, ifr, cmd);static iw_handler get_handler(struct net_device *dev, unsigned int cmd)/* Dont optimise the following variable, it will crash */unsigned intindex;/* *MUST* be unsigned */* Check if we have some wireless handlers defined */if (dev-wireless_handlers = NULL)return NULL;/* Try as a standard command */index = cmd - SIOCIWFIRST;if (index wireless_handlers-num_standard)return dev-wireless_handlers-standardindex;/* Try as a private command */index = cmd - SIOCIWFIRSTPRIV;/if (index wireless_handlers-num_private)return dev-wireless_handlers-privateindex;/该private命令的handler./* Not found */return NULL;下面wlan_private_args为本wifi网卡驱动的所能支持的所有命令,也就是iwpriv命令所能支持的所有命令struct iw_handler_def wlan_handler_def = num_standard:sizeof(wlan_handler) / sizeof(iw_handler),num_private:sizeof(wlan_private_handler) / sizeof(iw_handler),num_private_args:sizeof(wlan_private_args) / sizeof(struct iw_priv_args),standard:(iw_handler *) wlan_handler,private:(iw_handler *) wlan_private_handler,private_args:(struct iw_priv_args *) wlan_private_args,#if WIRELESS_EXT 20get_wireless_stats:wlan_get_wireless_stats,#endif;以下为示意代码,我们的wifi网卡驱动支持如下iwpriv命令.static const struct iw_priv_args wlan_private_args = extscan hostcmd arpfilter regrdwr sdcmd52rw sdcmd53rw setgetconf getcis scantype deauth getNF getRSSI bgscan enable11d adhocgrate sdioclock wmm uapsdnullgen setcoalescing adhocgprot setpowercons wmm_qosinfo lolisteninter fwwakeupmethod psnullinterval bcnmisto adhocawakepd moduletype autodeepsleep enhanceps wakeupmt setrxant settxant authalgs encryptionmode setregioncode setlisteninter setmultipledtim setbcnavg setdataavg associate getregioncode getlisteninter getmultipledtim gettxrate getbcnavg getdataavg getrxant gettxant gettsf wpssession deepsleep adhocstop radioon radiooff rmaeskey crypto_test reasso-on reasso-off wlanidle-on wlanidle-off sleepparams requesttpc powercap measreq bca-ts scanmode getadhocstatus setgenie getgenie qstatus ts_status setaeskey getaeskey version verext setwpaie setband setadhocch chanswann getband getadhocch getlog tpccfg scanprobes ledgpio sleeppd rateadapt getSNR getrate getrxinfo atimwindow bcninterval sdiopullctrl scantime sysclock txcontrol hscfg hssetpara inactoext dbgscfg drvdbg drvdelaymax intfctrl setquietie setuserscan getscantable setmrvltlv getassocrsp addts delts qconfig qstats txpktstats getcfptable mefcfg getmem;浅析ethx网卡控制函数ioctl实现具体流程=1.应用层程序iwprivwireless tools网络配置应用程序iwpriv命令格式:iwpriv ethX private-command parametersiwpriv部分实现源码如下:int main(int argc, char *argv) . sockfd = socket(AF_INET, SOCK_STREAM, 0); . ioctl(sockfd, ioctl_val, &iwr);/将控制命令通过ioctl发送到无线网卡 .=2.系统调用sys_ioctl应用层通过ioctl(sockfd, ioctl_val, &iwr);触发sys_ioctl系统调用,实际流程:sys_ioctl=vfs_ioctl=do_ioctl=最后调用filp-f_op-unlocked_ioctl执行具体的ioctl操作,该操作就是sock_ioctl,至于为什么是sock_ioctl,后边作了进一步分析sock_ioctl= . #ifdef CONFIG_WIRELESS_EXT if (cmd = SIOCIWFIRST & cmd wext_handle_ioctl ./* Take care of Wireless Extensions */ if (cmd = SIOCIWFIRST & cmd wireless_process_ioctl=然后通过if (dev = _dev_get_by_name(net, ifr-ifr_name) = NULL)函数,从系统管理的net链表中,把ioctl指定的ethX对应的struct net_device摘出来,最后调用ioctl_private_call(handler)或者调用dev-do_ioctl(dev, ifr, cmd)来处理该ioctl,这两个函数分别指向wlan_handler_def和wlan_do_ioctl=3.wifi网卡是怎么登记到kernel上的wlan_probe()=wlan_add_card()=alloc_etherdev()=之后将操作方法添加到struct net_device *dev=alloc_etherdev()申请的dev上去,其中包括: . /* Setup the OS Interface to our functions */ dev-open = wlan_open; dev-hard_start_xmit = wlan_hard_start_xmit; dev-stop = wlan_close; dev-do_ioctl = wlan_do_ioctl; dev-set_mac_address = wlan_set_mac_address; dev-tx_timeout = wlan_tx_timeout; dev-get_stats = wlan_get_stats; dev-watchdog_timeo = MRVDRV_DEFAULT_WATCHDOG_TIMEOUT; dev-wireless_handlers = (struct iw_handler_def *) &wlan_handler_def; dev-set_multicast_list = wlan_set_multicast_list; .4.socket系统调用如何关联上ioctl和ethX设备asmlinkage long sys_socket(int family, int type, int protocol);sys_socket=sock_create=_sock_create=sock = sock_alloc();通过sock_mnt-mnt_sb从socket文件系统的超级块上申请一个inode节点,这样也就同时获得了由该inode描述的一个sock结构体单元,所以sokcet和dentry目录项等效,接下来从net_families全局管理结构体中找到当前family对应的ops操作集,net_proto_family *pf=net_familiesfamily;pf-create(net, sock, protocol);/核心调用,对于ipv4,就是inet_create以ipv4为例static struct net_proto_family inet_family_ops = .family = PF_INET, .create = inet_create, .owner = THIS_MODULE,;还记得上面应用层创建sokcet的函数吧,sockfd = socket(AF_INET, SOCK_STREAM, 0);/AF_INET虽然等于PF_INET,但是因为种种原因我们提倡使用PF_INET可见family等于AF_INET,type等于SOCK_STREAM,协议protocol为0,也就是采用IP协议,inet_create=inetswsock-type也就是inetswSOCK_STREAM,从inetswsock-type中找到已经登记的protocol网络协议处理函数,inetsw是怎么填充的呢?inet_init()=inet_register_protosw(inetsw_array)=这样inetsw_array中的所有protocol处理模块都将登记到inetsw中了,static struct inet_protosw inetsw_array = .type = SOCK_STREAM, .protocol = IPPROTO_TCP, .prot = &tcp_prot, .ops = &inet_stream_ops, .capability = -1, .no_check = 0, .flags = INET_PROTOSW_PERMANENT | INET_PROTOSW_ICSK, , .type = SOCK_DGRAM, .protocol = IPPROTO_UDP, .prot = &udp_prot, .ops = &inet_dgram_ops, .capability = -1, .no_check = UDP_CSUM_DEFAULT, .flags = INET_PROTOSW_PERMANENT, , .type = SOCK_RAW, .protocol = IPPROTO_IP, /* wild card */ .prot = &raw_prot, .ops = &inet_sockraw_ops, .capability = CAP_NET_RAW, .no_check = UDP_CSUM_DEFAULT, .flags = INET_PROTOSW_REUSE, ;至于inet_init,则是以fs_initcall(inet_init)方式,以5号优先级被build in到了内核中,当kernel启动时会在start_kernel=rest_init=kernel_init=do_basic_setup=do_initcalls中依据优先级号优先于其他module驱动被调用.这样sock-ops = answer-ops;对于ipv4也就等于inet_stream_ops,接下来就是将ops填充到file操作指针中了,sys_socket=sock_map_fd=sock_attach_fd=dentry-d_op = &sockfs_dentry_operations;init_file(file, sock_mnt, dentry, FMODE_READ | FMODE_WRITE, &socket_file_ops);file-private_data = sock;其中init_file=file-f_op = fop;也就是file-f_op = socket_file_ops;所以read(),wirte(),poll()和ioctl()应用程序调用的file-f_op就是socket_file_ops了,比如:read()对应sock_aio_read网络异步读write()对应sock_aio_write网络异步写ioctl()对应sock_ioctlsocket_file_ops结构体具体实现如下:static const struct file_operations socket_file_ops = .owner = THIS_MODULE, .llseek = no_llseek, .aio_read = sock_aio_read, .aio_write = sock_aio_write, .poll = sock_poll, .unlocked_ioctl = sock_ioctl,#ifdef CONFIG_COMPAT .compat_ioctl = compat_sock_ioctl,#endif .mmap = sock_mmap, .open = sock_no_open, /* special open code to disallow open via /proc */ .release = sock_close, .fasync = sock_fasync, .sendpage = sock_sendpage, .splice_write = generic_splice_sendpage,;网卡控制因为涉及到的知识点比较多,上面只是从宏观上对数据流程做了一个简单的介绍,深入到其中的每个知识点,都会牵扯出一系列文章,读者需要自己去一个个的慢慢深入,希望本文能够对刚刚接触网络驱动的读者有所帮助和启发【gliethttp.Leith】wireless extention扩展接口Blog作者的回复:wlan_add_card=wlan_create_thread(wlan_service_main_thread, &priv-MainThread, wlan_main_service);=wlan_service_main_thread=wlan_exec_next_cmd=将调用wlan_enter_ps和wlan_exit_pssbi_interrupt=从sdio口上传来的中断数据,sdio_irq_thread=process_sdio_pending_irqs=调用func-irq_handler(func);即本.在mmc_signal_sdio_irq=将调用wake_up_process(host-sdio_irq_thread);来唤醒该irq处理线程,可能还有其他命令需要处理wlan_exec_next_cmd这个pxamci_irq就是mmc的物理irq中断了,pxamci_irq=mmc_signal_sdio_irq(host-mmc);wlan_exec_next_cmd=只要cmd链表上CmdNode还存在,那么就会执行wlan_dnld_cmd_to_fw(wlan_private * priv, CmdCtrlNode * CmdNode)将CmdNode中的数据下发下去,然后重新触发wlan_mod_timer(&Adapter-MrvDrvCommandTimer, MRVDRV_TIMER_5S);也就是wlan_cmd_timeout_func命令超时处理函数,在cmd已经有了恢复之后,在主线程中调用wlan_process_cmdresp,立即调用wlan_cancel_timer(&Adapter-MrvDrvCommandTimer);来删除定时器wlan_service_main_thread=每次唤醒都会检查= /* Execute the next command */ if (!priv-wlan_dev.cmd_sent & !Adapter-CurCmd) wlan_exec_next_cmd(priv);=wlan_prepare_cmd=wlan_hostcmd_ioctl=获取一个空闲的CmdNode节点wlan_get_cmd_node,当完成赋值之后,执行如下语句,将CmdNode节点添加到处理队列中:wlan_insert_cmd_to_pending_q(Adapter, CmdNode, TRUE);wake_up_interruptible(&priv-MainThread.waitQ);另外在数组中/* iwconfig settable callbacks */static const iw_handler wlan_handler这个数组中全部是回调函数,/* wlan_handler_def */struct iw_handler_def wlan_handler_def = num_standard:sizeof(wlan_handler) / sizeof(iw_handler), num_private:sizeof(wlan_private_handler) / sizeof(iw_handler), num_private_args:sizeof(wlan_private_args) / sizeof(struct iw_priv_args), standard:(iw_handler *) wlan_handler, private:(iw_handler *) wlan_private_handler, private_args:(struct iw_priv_args *) wlan_private_args,#if WIRELESS_EXT 20 get_wireless_stats:wlan_get_wireless_stats,#endif;在wlan_add_card函数中dev-wireless_handlers = (struct iw_handler_def *) &wlan_handler_def;=在kernel的net中使用wireless extention扩展接口static iw_handler get_handler(struct net_device *dev, unsigned int cmd) /* Dont optimise the following variable, it will crash */ unsigned int index; /* *MUST* be unsigned */ /* Check if we have some wireless handlers defined */ if (dev-wireless_handlers = NULL) return NULL; /* Try as a standard command */ index = cmd - SIOCIWFIRST; if (index wireless_handlers-num_standard) return dev-wireless_handlers-standardindex; /* Try as a private command */ index = cmd - SIOCIWFIRSTPRIV; if (index wireless_handlers-num_private) return dev-wireless_handlers-privateindex;