telnet_dev.c 文件参考

浏览源代码.

函数
STATIC INLINE TELNET_DEV_S *	GetTelnetDevByFile (const struct file *file, BOOL isOpenOp)
INT32	TelnetTx (const CHAR *buf, UINT32 bufLen)
STATIC INT32	TelnetOpen (struct file *file)
STATIC INT32	TelnetClose (struct file *file)
STATIC ssize_t	TelnetRead (struct file *file, CHAR *buf, size_t bufLen)
STATIC ssize_t	TelnetWrite (struct file *file, const CHAR *buf, const size_t bufLen)
STATIC INT32	TelnetIoctl (struct file *file, const INT32 cmd, unsigned long arg)
	远程登录控制操作 更多...
STATIC INT32	TelnetPoll (struct file *file, poll_table *table)
INT32	TelnetedUnregister (VOID)
INT32	TelnetedRegister (VOID)
INT32	TelnetDevInit (INT32 clientFd)
INT32	TelnetDevDeinit (VOID)

变量
STATIC TELNET_DEV_S	g_telnetDev
	远程登录设备 更多...
STATIC EVENT_CB_S *	g_event
STATIC struct Vnode *	g_currentVnode
STATIC const struct file_operations_vfs	g_telnetOps

函数说明

GetTelnetDevByFile()

STATIC INLINE TELNET_DEV_S * GetTelnetDevByFile	(	const struct file *	file,
		BOOL	isOpenOp
	)

在文件 telnet_dev.c 第 60 行定义.

{
    struct Vnode *telnetInode = NULL;
    TELNET_DEV_S *telnetDev = NULL;
 
    if (file == NULL) {
        return NULL;
    }
    telnetInode = file->f_vnode;
    if (telnetInode == NULL) {
        return NULL;
    }
    /*
     * Check if the f_vnode is valid here for non-open ops (open is supposed to get invalid f_vnode):
     * when telnet is disconnected, there still may be 'TelentShellTask' tasks trying to write
     * to the file, but the file has illegal f_vnode because the file is used by others.
     */
    if (!isOpenOp) {
        if (telnetInode != g_currentVnode) {
            return NULL;
        }
    }
    telnetDev = (TELNET_DEV_S *)((struct drv_data*)telnetInode->data)->priv;
    return telnetDev;
}

这是这个函数的调用关系图:

TelnetClose()

STATIC INT32 TelnetClose

(

struct file *

file

)

在文件 telnet_dev.c 第 174 行定义.

{
    struct wait_queue_head *wait = NULL;
    TELNET_DEV_S *telnetDev = NULL;
 
    TelnetLock();
 
    telnetDev = GetTelnetDevByFile(file, FALSE);
    if (telnetDev != NULL) {
        wait = &telnetDev->wait;
        LOS_ListDelete(&wait->poll_queue);
        free(telnetDev->cmdFifo);
        telnetDev->cmdFifo = NULL;
        (VOID)LOS_EventDestroy(&telnetDev->eventTelnet);
        g_event = NULL;
    }
    g_currentVnode = NULL;
    TelnetUnlock();
    return 0;
}

函数调用图:

TelnetDevDeinit()

INT32 TelnetDevDeinit

(

VOID

)

在文件 telnet_dev.c 第 405 行定义.

{
    INT32 ret;
 
    ret = system_console_deinit(TELNET);
    if (ret != 0) {
        PRINT_ERR("Telnet console deinit error.\n");
    }
    return ret;
}

函数调用图:

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TelnetDevInit()

INT32 TelnetDevInit

(

INT32

clientFd

)

在文件 telnet_dev.c 第 382 行定义.

{
    INT32 ret;
 
    if (clientFd < 0) {
        PRINT_ERR("Invalid telnet clientFd.\n");
        return -1;
    }
    ret = system_console_init(TELNET);//创建一个带远程登录功能的控制台
    if (ret != 0) {
        PRINT_ERR("Telnet console init error.\n");
        return ret;
    }
    ret = ioctl(STDIN_FILENO, CFG_TELNET_SET_FD, clientFd);//绑定FD,相当于shell和控制台绑定
    if (ret != 0) {
        PRINT_ERR("Telnet device ioctl error.\n");
        (VOID)system_console_deinit(TELNET);
    }
    return ret;
}

函数调用图:

这是这个函数的调用关系图:

TelnetedRegister()

INT32 TelnetedRegister

(

VOID

)

在文件 telnet_dev.c 第 365 行定义.

{
    INT32 ret;
 
    g_telnetDev.id = 0;
    g_telnetDev.cmdFifo = NULL;
    g_telnetDev.eventPend = TRUE;
    //注册 telnet 驱动, g_telnetDev为私有数据
    ret = register_driver(TELNET, &g_telnetOps, TELNET_DEV_DRV_MODE, &g_telnetDev);//翻译过来是当读TELNET时,真正要去操作的是 g_telnetDev
    if (ret != 0) {
        PRINT_ERR("Telnet register driver error.\n");
    }
    return ret;
}

这是这个函数的调用关系图:

TelnetedUnregister()

INT32 TelnetedUnregister

(

VOID

)

在文件 telnet_dev.c 第 354 行定义.

{
    free(g_telnetDev.cmdFifo);
    g_telnetDev.cmdFifo = NULL;
    (VOID)unregister_driver(TELNET);//注销字符设备驱动
 
    return 0;
}

函数调用图:

这是这个函数的调用关系图:

TelnetIoctl()

STATIC INT32 TelnetIoctl	(	struct file *	file,
		const INT32	cmd,
		unsigned long	arg
	)

远程登录控制操作

在文件 telnet_dev.c 第 285 行定义.

{
    TELNET_DEV_S *telnetDev = NULL;
 
    TelnetLock();
 
    telnetDev = GetTelnetDevByFile(file, FALSE);
    if (telnetDev == NULL) {
        TelnetUnlock();
        return -1;
    }
 
    if (cmd == CFG_TELNET_EVENT_PEND) {
        if (arg == 0) {
            telnetDev->eventPend = FALSE;
            (VOID)LOS_EventWrite(&(telnetDev->eventTelnet), TELNET_EVENT_MORE_CMD);
            (VOID)LOS_EventClear(&(telnetDev->eventTelnet), ~TELNET_EVENT_MORE_CMD);
        } else {
            telnetDev->eventPend = TRUE;
        }
    } else if (cmd == CFG_TELNET_SET_FD) {
        if (arg >= (FD_SETSIZE - 1)) {
            TelnetUnlock();
            return -1;
        }
        telnetDev->clientFd = (INT32)arg;
    }
    TelnetUnlock();
    return 0;
}

函数调用图:

TelnetOpen()

STATIC INT32 TelnetOpen

(

struct file *

file

)

在文件 telnet_dev.c 第 140 行定义.

{
    struct wait_queue_head *wait = NULL;
    TELNET_DEV_S *telnetDev = NULL;
 
    TelnetLock();
 
    telnetDev = GetTelnetDevByFile(file, TRUE);//获取标准file私有数据
    if (telnetDev == NULL) {
        TelnetUnlock();
        return -1;
    }
 
    if (telnetDev->cmdFifo == NULL) {
        wait = &telnetDev->wait;
        (VOID)LOS_EventInit(&telnetDev->eventTelnet);//初始化事件
        g_event = &telnetDev->eventTelnet;
        telnetDev->cmdFifo = (TELNTE_FIFO_S *)malloc(sizeof(TELNTE_FIFO_S));
        if (telnetDev->cmdFifo == NULL) {
            TelnetUnlock();
            return -1;
        }
        (VOID)memset_s(telnetDev->cmdFifo, sizeof(TELNTE_FIFO_S), 0, sizeof(TELNTE_FIFO_S));
        telnetDev->cmdFifo->fifoNum = FIFO_MAX;
        LOS_ListInit(&wait->poll_queue);
    }
    g_currentVnode = file->f_vnode;
    TelnetUnlock();
    return 0;
}

函数调用图:

TelnetPoll()

STATIC INT32 TelnetPoll	(	struct file *	file,
		poll_table *	table
	)

在文件 telnet_dev.c 第 316 行定义.

{
    TELNET_DEV_S *telnetDev = NULL;
 
    TelnetLock();
 
    telnetDev = GetTelnetDevByFile(file, FALSE);
    if ((telnetDev == NULL) || (telnetDev->cmdFifo == NULL)) {
        TelnetUnlock();
        return -1;
    }
 
    poll_wait(file, &telnetDev->wait, table);
 
    /* check if there are some commands to run */
    if (telnetDev->cmdFifo->fifoNum != FIFO_MAX) {
        TelnetUnlock();
        return POLLIN | POLLRDNORM;
    }
    TelnetUnlock();
    return 0;
}

函数调用图:

TelnetRead()

STATIC ssize_t TelnetRead	(	struct file *	file,
		CHAR *	buf,
		size_t	bufLen
	)

在文件 telnet_dev.c 第 203 行定义.

{
    UINT32 i;
    TELNET_DEV_S *telnetDev = NULL;
 
    TelnetLock();
 
    telnetDev = GetTelnetDevByFile(file, FALSE);//通过文件获取远程登录实体
    if ((buf == NULL) || (telnetDev == NULL) || (telnetDev->cmdFifo == NULL)) {
        TelnetUnlock();
        return -1;
    }
 
    if (telnetDev->eventPend) {//挂起时,说明没有数据可读,等待事件发生
        TelnetUnlock();
        (VOID)LOS_EventRead(g_event, TELNET_EVENT_MORE_CMD, LOS_WAITMODE_OR, LOS_WAIT_FOREVER);//等待读取 TELNET_EVENT_MORE_CMD 事件
        TelnetLock();
    }
 
    if (bufLen > (FIFO_MAX - telnetDev->cmdFifo->fifoNum)) {
        bufLen = FIFO_MAX - telnetDev->cmdFifo->fifoNum;
    }
    //把远程终端过来的数据接走, 一般由 Shell Entry 任务中的 read(fd,&buf)读走数据
    for (i = 0; i < bufLen; i++) {
        *buf++ = telnetDev->cmdFifo->rxBuf[telnetDev->cmdFifo->rxOutIndex++];
        if (telnetDev->cmdFifo->rxOutIndex >= FIFO_MAX) {
            telnetDev->cmdFifo->rxOutIndex = 0;
        }
    }
    telnetDev->cmdFifo->fifoNum += bufLen;
    /* check if no more commands left to run | 检查是否没有更多命令可以运行 */
    if (telnetDev->cmdFifo->fifoNum == FIFO_MAX) {
        (VOID)LOS_EventClear(&telnetDev->eventTelnet, ~TELNET_EVENT_MORE_CMD);//清除读取内容事件
    }
 
    TelnetUnlock();
    return (ssize_t)bufLen;
}

函数调用图:

TelnetTx()

INT32 TelnetTx	(	const CHAR *	buf,
		UINT32	bufLen
	)

在文件 telnet_dev.c 第 94 行定义.

{
    UINT32 i;
    TELNET_DEV_S *telnetDev = NULL;
 
    TelnetLock();
 
    telnetDev = &g_telnetDev;
    if ((buf == NULL) || (telnetDev->cmdFifo == NULL)) {
        TelnetUnlock();
        return -1;
    }
 
    /* size limited */
    if (bufLen > telnetDev->cmdFifo->fifoNum) {//一次拿不完数据的情况
        bufLen = telnetDev->cmdFifo->fifoNum;//只能装满
    }
 
    if (bufLen == 0) { //参数要先判断 @note_thinking
        TelnetUnlock();
        return 0;
    }
 
    /* copy commands to the fifo of the telnet device | 复制命令到telnet设备的fifo*/
    for (i = 0; i < bufLen; i++) {
        telnetDev->cmdFifo->rxBuf[telnetDev->cmdFifo->rxIndex] = *buf;
        telnetDev->cmdFifo->rxIndex++;
        telnetDev->cmdFifo->rxIndex %= FIFO_MAX;
        buf++;
    }
    telnetDev->cmdFifo->fifoNum -= bufLen;
 
    if (telnetDev->eventPend) {
        /* signal that there are some works to do */
        (VOID)LOS_EventWrite(&telnetDev->eventTelnet, TELNET_EVENT_MORE_CMD);
    }
    /* notify the command resolver task */
    notify_poll(&telnetDev->wait);
    TelnetUnlock();
 
    return (INT32)bufLen;
}

函数调用图:

这是这个函数的调用关系图:

TelnetWrite()

STATIC ssize_t TelnetWrite	(	struct file *	file,
		const CHAR *	buf,
		const size_t	bufLen
	)

在文件 telnet_dev.c 第 248 行定义.

{
    INT32 ret = 0;
    TELNET_DEV_S *telnetDev = NULL;
 
    TelnetLock();
 
    telnetDev = GetTelnetDevByFile(file, FALSE);
    if ((buf == NULL) || (telnetDev == NULL) || (telnetDev->cmdFifo == NULL)) {
        TelnetUnlock();
        return -1;
    }
 
    if (OS_INT_ACTIVE) {
        TelnetUnlock();
        return ret;
    }
 
    if (!OsPreemptable()) {//@note_thinking 这里为何要有这个判断?
        TelnetUnlock();
        return ret;
    }
 
    if (telnetDev->clientFd != 0) {
#ifdef LOSCFG_BASE_CORE_SWTMR_ENABLE
         /* DO NOT call blocking API in software timer task | 不要在软件定时器任务中调用阻塞 API */
        if (OsIsSwtmrTask(OsCurrTaskGet())) {
            TelnetUnlock();
            return ret;
        }
#endif
        ret = send(telnetDev->clientFd, buf, bufLen, 0);//向 socket 发送
    }
    TelnetUnlock();
    return ret;
}

函数调用图:

变量说明

g_currentVnode

STATIC struct Vnode* g_currentVnode

在文件 telnet_dev.c 第 58 行定义.

g_event

STATIC EVENT_CB_S* g_event

在文件 telnet_dev.c 第 57 行定义.

g_telnetDev

STATIC TELNET_DEV_S g_telnetDev

远程登录设备

在文件 telnet_dev.c 第 56 行定义.

g_telnetOps

STATIC const struct file_operations_vfs g_telnetOps

初始值:

= {
    TelnetOpen,
    TelnetClose,
    TelnetRead,
    TelnetWrite,
    NULL,
    TelnetIoctl,
    NULL,
#ifndef CONFIG_DISABLE_POLL
    TelnetPoll,
#endif
    NULL,
}

在文件 telnet_dev.c 第 339 行定义.