netif_add 网口 添加/修改/配置 源码分析 1
添加netif_add函数
struct netif *
netif_add(struct netif *netif, struct ip_addr *ipaddr, struct ip_addr *netmask,
struct ip_addr *gw,
void *state,
err_t (* init)(struct netif *netif),
err_t (* input)(struct pbuf *p, struct netif *netif))
{
static u8_t netifnum = 0;
/////// 初始化各个参数
/* reset new interface configuration state */
netif->ip_addr.addr = 0;
netif->netmask.addr = 0;
netif->gw.addr = 0;
netif->flags = 0;
#if LWIP_DHCP
/* netif not under DHCP control by default */
netif->dhcp = NULL;
#endif /* LWIP_DHCP */
#if LWIP_AUTOIP
/* netif not under AutoIP control by default */
netif->autoip = NULL;
#endif /* LWIP_AUTOIP */
#if LWIP_NETIF_STATUS_CALLBACK
netif->status_callback = NULL;
#endif /* LWIP_NETIF_STATUS_CALLBACK */
#if LWIP_NETIF_LINK_CALLBACK
netif->link_callback = NULL;
#endif /* LWIP_NETIF_LINK_CALLBACK */
#if LWIP_IGMP
netif->igmp_mac_filter = NULL;
#endif /* LWIP_IGMP */
#if ENABLE_LOOPBACK
netif->loop_first = NULL;
netif->loop_last = NULL;
#endif /* ENABLE_LOOPBACK */
/* remember netif specific state information data */
netif->state = state;
netif->num = netifnum++;
netif->input = input;
#if LWIP_NETIF_HWADDRHINT
netif->addr_hint = NULL;
#endif /* LWIP_NETIF_HWADDRHINT*/
#if ENABLE_LOOPBACK && LWIP_LOOPBACK_MAX_PBUFS
netif->loop_cnt_current = 0;
#endif /* ENABLE_LOOPBACK && LWIP_LOOPBACK_MAX_PBUFS */
///// 初始化结束
netif_set_addr(netif, ipaddr, netmask, gw);
/* call user specified initialization function for netif */
if (init(netif) != ERR_OK) {
return NULL;
}
/* add this netif to the list */
netif->next = netif_list;
netif_list = netif;
snmp_inc_iflist();
#if LWIP_IGMP
/* start IGMP processing */
if (netif->flags & NETIF_FLAG_IGMP) {
igmp_start( netif);
}
#endif /* LWIP_IGMP */
LWIP_DEBUGF(NETIF_DEBUG, ("netif: added interface %c%c IP addr ",
netif->name[0], netif->name[1]));
ip_addr_debug_print(NETIF_DEBUG, ipaddr);
LWIP_DEBUGF(NETIF_DEBUG, (" netmask "));
ip_addr_debug_print(NETIF_DEBUG, netmask);
LWIP_DEBUGF(NETIF_DEBUG, (" gw "));
ip_addr_debug_print(NETIF_DEBUG, gw);
LWIP_DEBUGF(NETIF_DEBUG, ("\n"));
return netif;
}
netif 结构体 硬件网络接口 详解见http://my.oschina.net/u/274829/blog/271848
struct ipaddr 32位的ip地址
PACK_STRUCT_BEGIN //与编译器有关
struct ip_addr {
PACK_STRUCT_FIELD(u32_t addr); //#define PACK_STRUCT_FIELD(x) x
} PACK_STRUCT_STRUCT;
PACK_STRUCT_END
netif_set_addr 改变ip地址、子网掩码、网关
void
netif_set_addr(struct netif *netif, struct ip_addr *ipaddr, struct ip_addr *netmask,
struct ip_addr *gw)
{
netif_set_ipaddr(netif, ipaddr);
netif_set_netmask(netif, netmask);
netif_set_gw(netif, gw);
}
netif_set_ipaddr()设置ip
void
netif_set_ipaddr(struct netif *netif, struct ip_addr *ipaddr)
{
/* TODO: Handling of obsolete pcbs */
/* See: http://mail.gnu.org/archive/html/lwip-users/2003-03/msg00118.html */
#if LWIP_TCP //TCP
struct tcp_pcb *pcb;
struct tcp_pcb_listen *lpcb;
/* address is actually being changed? */
if ((ip_addr_cmp(ipaddr, &(netif->ip_addr))) == 0)
{
/* extern struct tcp_pcb *tcp_active_pcbs; defined by tcp.h */
LWIP_DEBUGF(NETIF_DEBUG | 1, ("netif_set_ipaddr: netif address being changed\n"));
pcb = tcp_active_pcbs;
while (pcb != NULL) {
/* PCB bound to current local interface address? */
if (ip_addr_cmp(&(pcb->local_ip), &(netif->ip_addr))) {
/* this connection must be aborted */
struct tcp_pcb *next = pcb->next;
LWIP_DEBUGF(NETIF_DEBUG | 1, ("netif_set_ipaddr: aborting TCP pcb %p\n", (void *)pcb));
tcp_abort(pcb);
pcb = next;
} else {
pcb = pcb->next;
}
}
for (lpcb = tcp_listen_pcbs.listen_pcbs; lpcb != NULL; lpcb = lpcb->next) {
/* PCB bound to current local interface address? */
if ((!(ip_addr_isany(&(lpcb->local_ip)))) &&
(ip_addr_cmp(&(lpcb->local_ip), &(netif->ip_addr)))) {
/* The PCB is listening to the old ipaddr and
* is set to listen to the new one instead */
ip_addr_set(&(lpcb->local_ip), ipaddr);
}
}
}
#endif
snmp_delete_ipaddridx_tree(netif);
snmp_delete_iprteidx_tree(0,netif);
/* set new IP address to netif */
ip_addr_set(&(netif->ip_addr), ipaddr);
snmp_insert_ipaddridx_tree(netif);
snmp_insert_iprteidx_tree(0,netif);
LWIP_DEBUGF(NETIF_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE | 3, ("netif: IP address of interface %c%c set to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
netif->name[0], netif->name[1],
ip4_addr1(&netif->ip_addr), //设置ip 31-23位
ip4_addr2(&netif->ip_addr),
ip4_addr3(&netif->ip_addr),
ip4_addr4(&netif->ip_addr))); //ip 7-0位
}
netif_set_netmask()
void
netif_set_netmask(struct netif *netif, struct ip_addr *netmask)
{
snmp_delete_iprteidx_tree(0, netif);
/* set new netmask to netif */
ip_addr_set(&(netif->netmask), netmask);
snmp_insert_iprteidx_tree(0, netif);
LWIP_DEBUGF(NETIF_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE | 3, ("netif: netmask of interface %c%c set to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
netif->name[0], netif->name[1],
ip4_addr1(&netif->netmask),
ip4_addr2(&netif->netmask),
ip4_addr3(&netif->netmask),
ip4_addr4(&netif->netmask)));
}
netif_set_gw()
void
netif_set_gw(struct netif *netif, struct ip_addr *gw)
{
ip_addr_set(&(netif->gw), gw);
LWIP_DEBUGF(NETIF_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE | 3, ("netif: GW address of interface %c%c set to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
netif->name[0], netif->name[1],
ip4_addr1(&netif->gw),
ip4_addr2(&netif->gw),
ip4_addr3(&netif->gw),
ip4_addr4(&netif->gw)));
}
ethernetif_init()
err_t
ethernetif_init(struct netif *netif)
{
struct ethernetif *ethernetif;
LWIP_ASSERT("netif != NULL", (netif != NULL));
ethernetif = mem_malloc(sizeof(struct ethernetif));
if (ethernetif == NULL)
{
LWIP_DEBUGF(NETIF_DEBUG, ("ethernetif_init: out of memory\n"));
return ERR_MEM;
}
#if LWIP_NETIF_HOSTNAME
/* Initialize interface hostname */
netif->hostname = "ARMJISHU.COM_lwip";
#endif /* LWIP_NETIF_HOSTNAME */
/*
* Initialize the snmp variables and counters inside the struct netif.
* The last argument should be replaced with your link speed, in units
* of bits per second.
*/
NETIF_INIT_SNMP(netif, snmp_ifType_ethernet_csmacd, 100000000);
netif->state = ethernetif;
netif->name[0] = IFNAME0; //'s'
netif->name[1] = IFNAME1; //'t'
/* We directly use etharp_output() here to save a function call.
* You can instead declare your own function an call etharp_output()
* from it if you have to do some checks before sending (e.g. if link
* is available...) */
netif->output = etharp_output;
netif->linkoutput = low_level_output;
ethernetif->ethaddr = (struct eth_addr *)&(netif->hwaddr[0]);
/* initialize the hardware */
low_level_init(netif);
return ERR_OK;
}
struct ethernetif 状态
struct ethernetif
{
struct eth_addr *ethaddr; //6个字节
/* Add whatever per-interface state that is needed here. */
int unused;
};
PACK_STRUCT_BEGIN
struct eth_addr {
PACK_STRUCT_FIELD(u8_t addr[ETHARP_HWADDR_LEN]); //ETHARP_HWADDR_LEN = 6
} PACK_STRUCT_STRUCT;
PACK_STRUCT_END
etharp_output 检查IP地址
err_t
etharp_output(struct netif *netif, struct pbuf *q, struct ip_addr *ipaddr)
{
struct eth_addr *dest, mcastaddr;
/* make room for Ethernet header - should not fail */
if (pbuf_header(q, sizeof(struct eth_hdr)) != 0) {
/* bail out */
LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE | 2, ("etharp_output: could not allocate room for header.\n"));
LINK_STATS_INC(link.lenerr);
return ERR_BUF;
}
/* assume unresolved Ethernet address */
dest = NULL;
/* Determine on destination hardware address. Broadcasts and multicasts
* are special, other IP addresses are looked up in the ARP table. */
/* broadcast destination IP address? */
if (ip_addr_isbroadcast(ipaddr, netif)) { //是否广播
/* broadcast on Ethernet also */
dest = (struct eth_addr *)ðbroadcast;
/* multicast destination IP address? */
} else if (ip_addr_ismulticast(ipaddr)) { //是否多播地址
/* Hash IP multicast address to MAC address.*/
mcastaddr.addr[0] = 0x01;
mcastaddr.addr[1] = 0x00;
mcastaddr.addr[2] = 0x5e;
mcastaddr.addr[3] = ip4_addr2(ipaddr) & 0x7f;
mcastaddr.addr[4] = ip4_addr3(ipaddr);
mcastaddr.addr[5] = ip4_addr4(ipaddr);
/* destination Ethernet address is multicast */
dest = &mcastaddr;
/* unicast destination IP address? */
} else {
/* outside local network? */
if (!ip_addr_netcmp(ipaddr, &(netif->ip_addr), &(netif->netmask))) {
/* interface has default gateway? */
if (netif->gw.addr != 0) {
/* send to hardware address of default gateway IP address */
ipaddr = &(netif->gw);
/* no default gateway available */
} else {
/* no route to destination error (default gateway missing) */
return ERR_RTE;
}
}
/* queue on destination Ethernet address belonging to ipaddr */
return etharp_query(netif, ipaddr, q);
}
/* continuation for multicast/broadcast destinations */
/* obtain source Ethernet address of the given interface */
/* send packet directly on the link */
return etharp_send_ip(netif, q, (struct eth_addr*)(netif->hwaddr), dest);
}
l
static err_t
low_level_output(struct netif *netif, struct pbuf *p)
{
struct pbuf *q;
int l = 0;
u8 *buffer = (u8 *)ETH_GetCurrentTxBuffer();
for(q = p; q != NULL; q = q->next)
{
memcpy((u8_t*)&buffer[l], q->payload, q->len);
l = l + q->len;
}
ETH_TxPkt_ChainMode(l);
return ERR_OK;
}