【2018深信服 醒狮计划】《Linux应用编程》学习笔记
2018深信服“醒狮计划”笔记
第4~5周（5.14-5.27）
| 课程 | 必修 | 选修 | 基本要求 |
|---|---|---|---|
| Linux应用编程 | 《Linux 网络编程卷一》《Linux 网络编程卷二》 | 《《Linux4.0设备驱动开发详解》 | 主要熟练掌握Linux进程、线程模型、各种进程间通讯方式、网络套接字编程、基础后台模块架构模型 |
1. 工欲善其事必先利其器.
根据网上大佬们的建议,决定使用
Clion+Clang作为开发,为什么选择Clion,因为之前有做过Android开发,对JetBrains的一系列产品情有独钟,网上大佬各种吐槽gcc,强推Clang,那我就先这样试试.不行再换被,反正程序猿就是喜欢折腾.
怎么配置我就不说了,网上有很多
JetBrains产品目录:https://www.jetbrains.com/products.html?fromMenu
Ubuntu下安装clang:https://blog.csdn.net/straydragon/article/details/79323502
2. 根据checklist设置注释模板
有很多,自己去改把
文件头注释范例：
/*
功能：
日期：${TIME}
作者：luojie
*/
3. 下载本书的源码,遇到很多坑
1. 下载完成后查看README
Execute the following from the src/ directory:
./configure # try to figure out all implementation differences
cd lib # build the basic library that all programs need
make # use "gmake" everywhere on BSD/OS systems
cd ../libfree # continue building the basic library
make
cd ../libroute # only if your system supports 4.4BSD style routing sockets
make # only if your system supports 4.4BSD style routing sockets
cd ../libxti # only if your system supports XTI
make # only if your system supports XTI
cd ../intro # build and test a basic client program
make daytimetcpcli
./daytimetcpcli 127.0.0.1
If all that works, you're all set to start compiling individual programs.
Notice that all the source code assumes tabs every 4 columns, not 8.2. unpv13e/libfree目录下 make报错
inet_ntop.c:60:9: error: argument ‘size’ doesn’t match prototype
size_t size;解决方法:将inet_ntop.c中size_t改为socklen_t
3. unpv13e/libroute目录下 make报错
gcc -I../lib -g -O2 -D_REENTRANT -Wall -c -o get_rtaddrs.o get_rtaddrs.c
In file included from get_rtaddrs.c:1:0:
unproute.h:3:45: fatal error: net/if_dl.h: No such file or directory
compilation terminated.解决方法: 创建if_dl.h 放到/usr/include/net/下,下面是if_dl.h源码,可以复制创建文件
/*
* Copyright (c) 1990, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)if_dl.h 8.1 (Berkeley) 6/10/93
*/
/*
* A Link-Level Sockaddr may specify the interface in one of two
* ways: either by means of a system-provided index number (computed
* anew and possibly differently on every reboot), or by a human-readable
* string such as "il0" (for managerial convenience).
*
* Census taking actions, such as something akin to SIOCGCONF would return
* both the index and the human name.
*
* High volume transactions (such as giving a link-level ``from'' address
* in a recvfrom or recvmsg call) may be likely only to provide the indexed
* form, (which requires fewer copy operations and less space).
*
* The form and interpretation of the link-level address is purely a matter
* of convention between the device driver and its consumers; however, it is
* expected that all drivers for an interface of a given if_type will agree.
*/
/*
* Structure of a Link-Level sockaddr:
*/
struct sockaddr_dl {
u_char sdl_len; /* Total length of sockaddr */
u_char sdl_family; /* AF_DLI */
u_short sdl_index; /* if != 0, system given index for interface */
u_char sdl_type; /* interface type */
u_char sdl_nlen; /* interface name length, no trailing 0 reqd. */
u_char sdl_alen; /* link level address length */
u_char sdl_slen; /* link layer selector length */
char sdl_data[12]; /* minimum work area, can be larger;
contains both if name and ll address */
};
#define LLADDR(s) ((caddr_t)((s)->sdl_data + (s)->sdl_nlen))
#ifndef KERNEL
#include 4. RTAX_MAX变量未声明
README里面说BSD的系统才用编译这个。自己的系统是基于Ubuntu系统，所以不用编译这个,直接跳到第五步。
get_rtaddrs.c:21:18: error: ‘RTAX_MAX’ undeclared (first use in this function)
for (i = 0; i < RTAX_MAX; i++) {
^解决办法:get_rtaddrs.c 中RTAX_MAX变量未声明，在/libroute/unproute.h 加 #define RTAX_MAX 1024
5. Run
linux 现在因为安全问题，各个发行版本默认是不开
daytime服务的。第一个例子实际上是
两个程序，客户端和服务端,所以要开两个终端
- 一个运行:
make daytimetcpsrv
sudo ./daytimetcpsrv- 另一个运行
./daytimetcpcli 127.0.0.1- 返回结果:
Wed May 16 16:37:05 2018
详情可以参考:https://www.jianshu.com/p/a0037f327b96