網絡套接字入口函數

//所有的網絡套接字系統調用函數（socket bind listen connect ）都使用一個共同的入口函數：sys_socketcall
/*
第一個參數call表示被調用的應用層接口函數，第二個參數是一個指針，指向具體被調用函數（如accept函數）所需要的參數。
這些在用戶系統調用時傳入的參數將原封不動地傳遞給內核網絡棧相關底層函數使用
*/
asmlinkage int sys_socketcall(int call, unsigned long *args)

int er;
switch(call)
{
case SYS_SOCKET:
er=verify_area(VERIFY_READ, args, 3 * sizeof(long));
if(er)
return er;
return(sock_socket(get_fs_long(args+0),
get_fs_long(args+1),
get_fs_long(args+2)));
case SYS_BIND:
er=verify_area(VERIFY_READ, args, 3 * sizeof(long));
if(er)
return er;
return(sock_bind(get_fs_long(args+0),
(struct sockaddr *)get_fs_long(args+1),
get_fs_long(args+2)));
case SYS_CONNECT:
er=verify_area(VERIFY_READ, args, 3 * sizeof(long));
if(er)
return er;
return(sock_connect(get_fs_long(args+0),
(struct sockaddr *)get_fs_long(args+1),
get_fs_long(args+2)));
case SYS_LISTEN:
er=verify_area(VERIFY_READ, args, 2 * sizeof(long));
if(er)
return er;
return(sock_listen(get_fs_long(args+0),
get_fs_long(args+1)));
case SYS_ACCEPT:
er=verify_area(VERIFY_READ, args, 3 * sizeof(long));
if(er)
return er;
return(sock_accept(get_fs_long(args+0),
(struct sockaddr *)get_fs_long(args+1),
(int *)get_fs_long(args+2)));
case SYS_GETSOCKNAME:
er=verify_area(VERIFY_READ, args, 3 * sizeof(long));
if(er)
return er;
return(sock_getsockname(get_fs_long(args+0),
(struct sockaddr *)get_fs_long(args+1),
(int *)get_fs_long(args+2)));
case SYS_GETPEERNAME:
er=verify_area(VERIFY_READ, args, 3 * sizeof(long));
if(er)
return er;
return(sock_getpeername(get_fs_long(args+0),
(struct sockaddr *)get_fs_long(args+1),
(int *)get_fs_long(args+2)));
case SYS_SOCKETPAIR:
er=verify_area(VERIFY_READ, args, 4 * sizeof(long));
if(er)
return er;
return(sock_socketpair(get_fs_long(args+0),
get_fs_long(args+1),
get_fs_long(args+2),
(unsigned long *)get_fs_long(args+3)));
case SYS_SEND:
er=verify_area(VERIFY_READ, args, 4 * sizeof(unsigned long));
if(er)
return er;
return(sock_send(get_fs_long(args+0),
(void *)get_fs_long(args+1),
get_fs_long(args+2),
get_fs_long(args+3)));
case SYS_SENDTO:
er=verify_area(VERIFY_READ, args, 6 * sizeof(unsigned long));
if(er)
return er;
return(sock_sendto(get_fs_long(args+0),
(void *)get_fs_long(args+1),
get_fs_long(args+2),
get_fs_long(args+3),
(struct sockaddr *)get_fs_long(args+4),
get_fs_long(args+5)));
case SYS_RECV:
er=verify_area(VERIFY_READ, args, 4 * sizeof(unsigned long));
if(er)
return er;
return(sock_recv(get_fs_long(args+0),
(void *)get_fs_long(args+1),
get_fs_long(args+2),
get_fs_long(args+3)));
case SYS_RECVFROM:
er=verify_area(VERIFY_READ, args, 6 * sizeof(unsigned long));
if(er)
return er;
return(sock_recvfrom(get_fs_long(args+0),
(void *)get_fs_long(args+1),
get_fs_long(args+2),
get_fs_long(args+3),
(struct sockaddr *)get_fs_long(args+4),
(int *)get_fs_long(args+5)));
case SYS_SHUTDOWN:
er=verify_area(VERIFY_READ, args, 2* sizeof(unsigned long));
if(er)
return er;
return(sock_shutdown(get_fs_long(args+0),
get_fs_long(args+1)));
case SYS_SETSOCKOPT:
er=verify_area(VERIFY_READ, args, 5*sizeof(unsigned long));
if(er)
return er;
return(sock_setsockopt(get_fs_long(args+0),
get_fs_long(args+1),
get_fs_long(args+2),
(char *)get_fs_long(args+3),
get_fs_long(args+4)));
case SYS_GETSOCKOPT:
er=verify_area(VERIFY_READ, args, 5*sizeof(unsigned long));
if(er)
return er;
return(sock_getsockopt(get_fs_long(args+0),
get_fs_long(args+1),
get_fs_long(args+2),
(char *)get_fs_long(args+3),
(int *)get_fs_long(args+4)));
default:
return(-EINVAL);
}
}