#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 (v4_route_target_import,
v4_route_target_import_cmd,
"rt-import ASN:nn",
"Route target import\n"
"ASN:nn, e.g., 100:1\n")
{
return bgp__rt_import (SAFI_MPLS_VPN, vty, argv[0]);
}
处理函数声明:
Static int bgp__rt_import (safi_t safi, struct vty *vty, const char *rt_str);
int
bgp__rt_import (safi_t safi, struct vty *vty,
const char *rt_str)
{
return CMD_SUCCESS;
}
void
bgp_mpls_init (void)
{
install_element (BGP_VPNV4_NODE, &v4_network_cmd);
install_element (BGP_VPNV4_NODE, &v4_network_route_map_cmd);
install_element (BGP_VPNV4_NODE, &v4_route_target_import_cmd);
install_element (BGP_VPNV4_NODE, &v4_route_target_export_cmd);
...
}
/* 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. */
void
install_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:
void
bgp_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_v4_node, NULL);
install_node (&bgp_v6_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 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);