quagga中cli命令分析

在已有的命令视图中新增加命令

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定义命令并处理

• 定义命令，
  DEFUN(处理函数，命令名称，命令字符串，帮助信息)

#define DEFUN(funcname, cmdname, cmdstr, helpstr) \  DEFUN_CMD_FUNC_DECL(funcname) \  DEFUN_CMD_ELEMENT(funcname, cmdname, cmdstr, helpstr, 0, 0) \  DEFUN_CMD_FUNC_TEXT(funcname)

DEFUN (vpnv4_route_target_import,       vpnv4_route_target_import_cmd,       "rt-import ASN:nn",       "Route target import\n"       "ASN:nn, e.g., 100:1\n"){  return bgp_vpn_rt_import (SAFI_MPLS_VPN, vty, argv[0]);}

处理函数声明： Static int bgp_vpn_rt_import (safi_t safi, struct vty *vty, const char *rt_str)； 

• 处理函数实现；

int bgp_vpn_rt_import (safi_t safi, struct vty *vty,                      const char *rt_str){    return CMD_SUCCESS;}

• 安装该命令到对应的命令视图下，
  Install_element(命令视图，命令名称)

voidbgp_mplsvpn_init (void){  install_element (BGP_VPNV4_NODE, &vpnv4_network_cmd);  install_element (BGP_VPNV4_NODE, &vpnv4_network_route_map_cmd);  install_element (BGP_VPNV4_NODE, &vpnv4_route_target_import_cmd);  install_element (BGP_VPNV4_NODE, &vpnv4_route_target_export_cmd);  ...}

show running显示命令

• show running读取命令的位置

/* Write current configuration into the terminal. */ALIAS (config_write_terminal,       show_running_config_cmd,       "show running-config",       SHOW_STR       "running configuration\n")

可以看到show running使用的是config_write_terminal这个函数体，它的实现在：

/* Write current configuration into the terminal. */DEFUN (config_write_terminal,       config_write_terminal_cmd,       "write terminal",       "Write running configuration to memory, network, or terminal\n"       "Write to terminal\n"){  unsigned int i;  struct cmd_node *node;  if (vty->type == VTY_SHELL_SERV)    {      for (i = 0; i < vector_active (cmdvec); i++)    if ((node = vector_slot (cmdvec, i)) && node->func && node->vtysh)      {        if ((*node->func) (vty))          vty_out (vty, "!%s", VTY_NEWLINE);      }    }  else    {      vty_out (vty, "%sCurrent configuration:%s", VTY_NEWLINE,           VTY_NEWLINE);      vty_out (vty, "!%s", VTY_NEWLINE);      for (i = 0; i < vector_active (cmdvec); i++)    if ((node = vector_slot (cmdvec, i)) && node->func)      {        if ((*node->func) (vty))          vty_out (vty, "!%s", VTY_NEWLINE);      }      vty_out (vty, "end%s",VTY_NEWLINE);    }  return CMD_SUCCESS;}

执行show running时调用了node->func函数，install_node时会给node->func赋值：

/* Install top node of command vector. */voidinstall_node (struct cmd_node *node,           int (*func) (struct vty *)){  vector_set_index (cmdvec, node->node, node);  node->func = func;  node->cmd_vector = vector_init (VECTOR_MIN_SIZE);}

只要func不为null，调用show running就会执行此函数。以BGP为例，install_node定义的位置如下：

voidbgp_vty_init (void){  /* Install bgp top node. */  install_node (&bgp_node, bgp_config_write);  install_node (&bgp_ipv4_unicast_node, NULL);  install_node (&bgp_ipv4_multicast_node, NULL);  install_node (&bgp_ipv6_unicast_node, NULL);  install_node (&bgp_ipv6_multicast_node, NULL);  install_node (&bgp_vpnv4_node, NULL);  install_node (&bgp_vpnv6_node, NULL);  install_node (&bgp_encap_node, NULL);  install_node (&bgp_encapv6_node, NULL);  /* Install default VTY commands to new nodes.  */  install_default (BGP_NODE);  install_default (BGP_IPV4_NODE);  ... }

可以看到执行的是bgp_config_write函数，可以把需要显示的命令及数值添加到函数里，以配置的bgp vpn rt为例，需要在对应的node视图下添加：

vty_out (vty, " rt-export %s", rt_export_buf);          vty_out (vty, "%s", VTY_NEWLINE);

在quagga的基础上新增加命令视图(转)

• 定义命令视图类型，enum node_type ；
• 定义命令视图结构，struct cmd_node；
  Static struct cmd_node 视图名称={
  命令视图类型，
  该视图下的提示符字符串，
  }；
• 安装命令视图，install_node(),install_default()；
  Install_node(视图名称，回调函数)
  Install_default(视图类型)