Openwrt ubox应用例子: 实现C/S网络通信

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Openwrt ubox应用例子: 实现C/S网络通信

ubox是Openwrt的一个帮助工具包, 包含了MD5,链表,平衡树,blob标签式二进制数据包的生成和解释......等等基础API, 以及uloop,usock,ustream,ulog等应用。 通过学习ubox可以更好地理解和融入Openwrt框架体系。

通过应用其中的uloop和usock可实现基于文件句柄监控和事件驱动机制的C/S结构网络通信应用。
以下是一个实现的小例子：

1.  服务端  usock_server.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/time.h>
#include <libubox/usock.h>
#include <libubox/uloop.h>static char *host_addr="192.168.1.9";
static char *server_port="5678";
static char *strhello="Welcome to UBOX world!\n";
static char *strreply="Add client to uloop_fd_event successfully!\n";/*  client fd event call_back */
void sevent_cb(struct uloop_fd *fd, unsigned int events)
{char buf[1024];struct timeval tm;int ret;gettimeofday(&tm,NULL);if(events & ULOOP_READ) {printf("%ld: ULOOP_READ is triggered! sock fd=%d,  events=%d\n", tm.tv_sec,fd->fd, events);ret=read(fd->fd, buf, sizeof(buf));buf[ret]=0;printf("Client MSG: %s \n", buf);if(events & ULOOP_WRITE) {write(fd->fd, strhello, strlen(strhello));}}
}/* server fd event call_back function */
void server_cb(struct uloop_fd *fd, unsigned int events)
{printf("server_cb is triggered! events=%d\n",events);int client_fd=accept(fd->fd, NULL,0);if(client_fd<0) {perror("server_cb accept");return;}printf(" >>>>>>> New client accepted! >>>>>>\n");write(client_fd,strhello,strlen(strhello));struct uloop_fd *ucli_fd=calloc(1,sizeof(struct uloop_fd));if(ucli_fd==NULL)return;/* add client fd to uloop event */ucli_fd->fd= client_fd;ucli_fd->cb = sevent_cb;printf("Add client to uloop_fd...\n");uloop_fd_add(ucli_fd, ULOOP_READ | ULOOP_WRITE | ULOOP_EDGE_TRIGGER);
}struct uloop_fd server_fd = {.cb = server_cb,
};void main(void)
{int sfd;char buf[1024];/* 1. init uloop */uloop_init();/* 2. create server usock */sfd=usock(USOCK_TCP|USOCK_SERVER, host_addr, server_port);if(sfd<0) {perror("usock");exit(-1);}printf("Succeed to create server at %s:%s\n",host_addr, server_port);/* 3. add server fd to uloop event */server_fd.fd=sfd;uloop_fd_add(&server_fd, ULOOP_READ | ULOOP_EDGE_TRIGGER); /* read only *//* 4. loop events monitoring */uloop_run();/* 5. end uloop */uloop_done();
}

2. 客户端  usock_client.c

#include <stdio.h>
#include <stdlib.h>
#include <libubox/usock.h>
#include <libubox/uloop.h>
#include <string.h>
#include <sys/time.h>char *host_addr="192.168.1.9";
char *server_port="5678";
char *strhello="Hello UBOX!";void cevent_cb(struct uloop_fd *fd, unsigned int events)
{char buf[1024];struct timeval tm;gettimeofday(&tm,NULL);if(events & ULOOP_READ) {printf("%ld: event ULOOP_READ is triggered! sock fd=%d,  events=%d\n",tm.tv_sec, fd->fd, events);read(fd->fd, buf, sizeof(buf));printf("MSG from server: %s \n", buf);if(events & ULOOP_WRITE) {write(fd->fd, strhello, strlen(strhello));}sleep(1);}
}struct uloop_fd client_fd =
{.cb = cevent_cb,
};void main(void)
{int cfd;char buf[1024];int ret;uloop_init();cfd=usock(USOCK_TCP, host_addr, server_port);if(cfd<0) {perror("usock");exit(-1);}printf("Connect to server %s:%s successfuly!\n", host_addr, server_port);ret=read(cfd, buf, sizeof(buf));buf[ret]=0;printf("receive msg: %s\n",buf);/* send a msg to trigger ping_pong events */write(cfd, strhello, strlen(strhello));client_fd.fd=cfd;uloop_fd_add(&client_fd, ULOOP_READ | ULOOP_WRITE );printf("start uloop_run() ...\n");uloop_run();uloop_done();
}

3. 本例子在openwrt  widora环境下编译通过, Makefile 如下：

export STAGING_DIR=/home/midas-zhou/openwrt_widora/staging_dir
COMMON_USRDIR=/home/midas-zhou/openwrt_widora/staging_dir/target-mipsel_24kec+dsp_uClibc-0.9.33.2/usr/CC= $(STAGING_DIR)/toolchain-mipsel_24kec+dsp_gcc-4.8-linaro_uClibc-0.9.33.2/bin/mipsel-openwrt-linux-gccCFLAGS  += -I$(COMMON_USRDIR)/include
LDFLAGS += -L$(COMMON_USRDIR)/lib
LIBS    += -luboxall:	 usock_server usock_client test_timeoutusock_server:   usock_server.c$(CC) $(CFLAGS) $(LDFLAGS) $(LIBS) usock_server.c -o usock_serverusock_client:   usock_client.c$(CC) $(CFLAGS) $(LDFLAGS) $(LIBS) usock_client.c -o usock_clientclean:rm -rf *.o usock_server usock_client

4. 在openwrt中试验, 首先运行usock_server,  然后启动若干个usock_client, 观察实际效果。

5. 备注:  程序中host_addr 和 Makefile环境变量请根据自己实际情况修改。