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_ioctl
if (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 int cmd,
iw_handler handler)
{
...
/* Call the handler */
ret = handler(dev, &info, &(iwr->u), extra);
if (user_length < iwr->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(priv[0]));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 < SIOCIWFIRSTPRIV)
return ioctl_standard_call(dev, ifr, cmd, handler);
else
//如果有对应的handler,那么处理iwpriv的命令,可以我们的iwpriv都是由dev->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->private[index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)
{
/* Don't "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 < dev->wireless_handlers->num_standard)
return dev->wireless_handlers->standard[index];
/* Try as a private command */
index = cmd - SIOCIWFIRSTPRIV;//
if (index < dev->wireless_handlers->num_private)
return dev->wireless_handlers->private[index];//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 > 20
get_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iwpriv
wireless tools网络配置应用程序iwpriv命令格式:
iwpriv ethX private-command [parameters]
iwpriv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 <= SIOCIWLAST) {
err = dev_ioctl(net, cmd, argp);//
} else
#endif
...
}
dev_ioctl=>wext_handle_ioctl
{
...
/* Take care of Wireless Extensions */
if (cmd >= SIOCIWFIRST && cmd <= SIOCIWLAST)
return wext_handle_ioctl(net, &ifr, cmd, arg);
...
}
wext_handle_ioctl=>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_families[family];
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=>inetsw[sock->type]也就是inetsw[SOCK_STREAM],
从inetsw[sock->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_ioctl
socket_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_ps
sbi_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)
{
/* Don't "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 < dev->wireless_handlers->num_standard)
return dev->wireless_handlers->standard[index];
/* Try as a private command */
index = cmd - SIOCIWFIRSTPRIV;
if (index < dev->wireless_handlers->num_private)
return dev->wireless_handlers->private[index];
/* Not found */
return NULL;
}
=>sock_ioctl
=>dev_ioctl
+++/* Take care of Wireless Extensions */
+++if (cmd >= SIOCIWFIRST && cmd <= SIOCIWLAST)
+++return wext_handle_ioctl(net, &ifr, cmd, arg);
=>wext_handle_ioctl
=>wireless_process_ioctl(struct net *net, struct ifreq *ifr, unsigned int cmd)
=>get_handler(dev, cmd);如果没有实现该cmd,那么将调用dev->do_ioctl来处理,
wlan_reassoc_timer_func=>
wmm_start_queue=>
wlan_tx_packet=>
wlan_tx_timeout=>
wlan_remove_card=>
wlan_hostcmd_ioctl=>
wlan_auto_deep_sleep=>
wlan_set_deep_sleep=>
wlan_prepare_cmd=>
wlan_cmd_timeout_func=>
将调用wake_up_interruptible(&priv->MainThread.waitQ);唤醒wlan_service_main_thread主处理线程.
wlan_hard_start_xmit=>wlan_tx_packet发送数据包
dev->tx_timeout = wlan_tx_timeout;
wlan_initialize_timer(&Adapter->MrvDrvCommandTimer, wlan_cmd_timeout_func, priv);
int wlan_do_ioctl(struct net_device *dev, struct ifreq *req, int cmd)
{
...
case WLAN_WAKEUP_MT:
if (wrq->u.data.length > 0)
Adapter->IntCounter++;
wake_up_interruptible(&priv->MainThread.waitQ);
break;
...
}
在wlan_process_cmdresp()处理完该cmd之后,调用
wlan_insert_cmd_to_free_q=>wlan_clean_cmd_noder,从命令链表上删除已经处理完成的cmd_node,
wlan_clean_cmd_noder然后pTempNode->CmdWaitQWoken = TRUE;同时如果该cmd_node是一个被阻塞等待的,那么唤醒等待的程序.
wake_up_interruptible(&pTempNode->cmdwait_q);
