lsn37linux网卡驱动实战编写

Linux络接口卡（NIC）驱LinuxNICdriver数据接口与socket接口体NICdriverNIC数据结构sk_buff与structsk_buff{union{structstructsk_buff*next;structsk_buff*prev;ktime_tstamp;structrb_nodestruct structnet_device unsignedintlen;unsignedintu16u16u32priority;Dma__tdma_;Sk_buff_data_ttail;Sk_buff_data_tend;unsignedchar*head;unsignedchar*data;unsignedinttruesize;Atomic_tusers;NextprevSk:socket关联packetTstamp包到达与搁置的时间Rbnode:Dev:代表数据操作的deviceLen:packet的总数量Mac_lenmacheader的长度Csum:packet’schecksumPriority代表packetQosHead指向socketbuffer的headEnd:socketbuffer的endStructnet_device就是一个美丽的错误，夹杂了协议与IOStruct当ifconfigeth0upNdo_openndo_validate_addr被调用当ifconfigeth0down,Ndo_stop被调用当MTU被改变的时候，ndo_change_mtu被调用当mac被改变的时候，ndo_set_mac_addressNetif_start_queue开始传输，放在ndo_openNetif_stop_queue停止传输，放在ndo_stop在ndo_open更新网络接口的mac请求资源，IOmemoryDMAchannelMapIRQ调用net_if_start_queue，让内核知道driver在probe分配一个networkdevice初始化bus请求与映射资源（IOmemoryDMAchannel填充netdevif_portirq,netdev_ops调用sha512./certs/signing_key.pem./certs/signing_key.x509#include#include#include<linux/netdevice.h>#include<linux/etherdevice.h>#includeMODULE_DESCRIPTION("Kernelmodulefornic");#define#definestructnic_privunsignedchar*tx_buf;unsignedinttx_len;u32msg_enable;staticstructnet_devicestaticvoiddump(unsignedchar*buffer)unsignedchar*p,sbuf[2*(sizeof(structethhdr)+intp=for(i=0;i<sizeof(structethhdr);i++)p+=sprintf(p,"%02X",}printk("eth%s\n",p=for(i=0;i<sizeof(structiphdr);i++)p+=sprintf(p,"%02X",buffer[sizeof(structethhdr)+}printk("iph%s\n",p=for(i=0;i<4;i++)p+=sprintf(p,"%02X",buffer[sizeof(structethhdr)+sizeof(structiphdr)+i]);}printk("payload%s\n",}staticvoidnic_rx(structnet_device*dev,intlen,unsignedchar{structsk_buffstructnic_priv*priv=netif_info(priv,hw,dev,"%s(#%d),func,LINE,skb=dev_alloc_skb(len+2);if(!skb){netif_err(priv,rx_err,"%s(#%d),rx:lowonmem-packetfunc,LINEreturn;}skb_reserve(skb,2);memcpy(skb_put(skb,len),buf,len);skb->dev=skb->protocol=eth_type_trans(skb,dev);skb->ip_summed=CHECKSUM_UNNECESSARY;dev->stats.rx_packets++;dev->stats.rx_bytes+=len;}staticintnic_open(structnet_device*dev)structnic_priv*priv=netdev_priv(dev);netif_info(priv,ifup,dev,"%s(#%d),priv:%p\n",func,LINE,priv->tx_buf=kmalloc(MAX_ETH_FRAME_SIZE,GFP_KERNEL);if(priv->tx_buf==NULL){netif_info(priv,ifup,dev,"%s(#%d),cannotalloctxfunc,return-ENOMEM;}

LINEreturn0;}staticintnic_stop(structnet_device*dev)structnic_priv*priv=netdev_priv(dev);netif_info(priv,ifdown,dev,"%s(#%d),priv:%p\n",func,LINE,if(priv->tx_buf) }return}staticvoidnic_hw_xmit(structnet_device*dev)structnic_priv*priv=netdev_priv(dev);structiphdr*iph;u32*saddr,*daddr;structin_device*in_dev;structin_ifaddrif(priv->tx_len<sizeof(structethhdr)+sizeof(structiphdr)){netif_info(priv,hw,dev,"%s(#%d),tooshort\n",func,LINEreturn}iph=(structiphdr*)(priv->tx_buf+sizeof(structethhdr));saddr=&iph->saddr;daddr=&iph-netif_info(priv,hw,dev,"%s(#%d),orig,src:%pI4,dst:%pI4,func,LINE,saddr,daddr,priv-in_dev=nic_dev[(dev==nic_dev[0]?1:0)]->ip_ptr;if(in_dev){//if_info=in_dev-for(if_info=in_dev->ifa_list;if_info;if_info=if_info->ifa_next){*saddr=*daddr=if_info->ifa_address;netif_info(priv,hw,dev,"%s(#%d),new,src:%pI4,}

func

LINE,saddr,if(!if_info)dev->stats.tx_droppednetif_info(priv,hw,dev,"%s(#%d),dropreturn}}

func

LINEiph->check=iph->check=ip_fast_csum((unsignedchar*)iph,iph-dev->stats.tx_packetsdev->stats.tx_bytes+=priv-nic_rx(nic_dev[(dev==nic_dev[0]?1:0)],priv->tx_len,}staticnetdev_tx_tnic_start_xmit(structsk_buff*skb,structnet_device*dev){structnic_priv*priv=netif_info(priv,drv,dev,"%s(#%d),orig,src:%pI4,func,LINE,&(ip_hdr(skb)->saddr),priv->tx_len=skb-if(likely(priv->tx_len<MAX_ETH_FRAME_SIZE)){if(priv->tx_len<ETH_ZLEN){memset(priv->tx_buf,0,ETH_ZLEN);priv->tx_len=ETH_ZLEN;}skb_copy_and_csum_dev(skb,priv->tx_buf); }else dev->stats.tx_dropped++;return}return}staticintnic_validate_addr(structnet_device*dev){structnic_priv*priv=netdev_priv(dev);netif_info(priv,drv,dev,"%s(#%d),priv:%p\n",func,LINE,return}staticintnic_change_mtu(structnet_device*dev,intnew_mtu){structnic_priv*priv=netdev_priv(dev);netif_info(priv,drv,dev,"%s(#%d),func,LINE,returneth_change_mtu(dev,}staticintnic_set_mac_addr(structnet_device*dev,void*addr)structnic_priv*priv=netdev_priv(dev);netif_info(priv,drv,dev,"%s(#%d),priv:%p\n",func,LINE,returneth_mac_addr(dev,}staticintnic_header_create(structsk_buff*skb,structunsignedshorttype,constvoid*daddr,constvoid*saddr,unsignedintlen){structnic_priv*priv=structethhdr*eth=(structethhdr*)skb_push(skb,ETH_HLEN);structnet_device*dst_netdev;netif_info(priv,drv,dev,func,LINEdst_netdev=nic_dev[(dev==nic_dev[0]?1:0)];eth->h_proto=htons(type);memcpy(eth->h_source,saddr?saddr:dev->dev_addr,memcpy(eth->h_dest,dst_netdev->dev_addr,dst_netdev-returndev-}staticconststructheader_opsnic_header_ops=.create=staticconststructnet_device_opsnic_netdev_ops=.ndo_open=.ndo_stop=.ndo_validate_addr=.ndo_start_xmit=.ndo_change_mtu=.ndo_set_mac_address=staticstructnet_device*nic_alloc_netdev(void)structnet_device*netdev=alloc_etherdev(sizeof(structif(!netdev)pr_err("%s(#%d):allocdevfailed",returnNULL;}

func

LINEnetdev->netdev_ops=&nic_netdev_ops;netdev->flags|=IFF_NOARP;netdev->features|=NETIF_F_HW_CSUM;netdev->header_ops=&nic_header_ops;return}staticintinitnic_init(void)intret=structnic_privpr_info("%s(#%d):install

func

LINEnic_dev[0]=nic_alloc_netdev();if(!nic_dev[0]){printk("%s(#%d):allocnetdev[0]LINEreturn-

func}nic_dev[1]=nic_alloc_netdev();if(!nic_dev[1]){printk("%s(#%d):allocnetdev[1]LINEgoto

func}ret=register_netdev(nic_dev[0]);if(ret){printk("%s(#%d):regnetdriverfailed.ret:LINE,goto

func}ret=register_netdev(nic_dev[1]);if(ret){printk("%s(#%d):regnetdriverfailed.LINE,goto

func}priv=netdev_pri