[网络协议]TCP 网络编程 阶段复习 （一）

#include <arpa/inet.h>
#include <asm-generic/socket.h>
#include <fcntl.h>
#include <netinet/in.h>
#include <stdio.h>
#include <stdint.h>
#include <strings.h>
#include <sys/socket.h>
#include <sys/select.h>
#include <sys/fcntl.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>

#define PORT 1234
#define MAX_QUE_CONN_NM 5
#define BUFFER_SIZE 1024

void config_socket_addr_afinet(struct sockaddr_in *addr,uint16_t port,const char* saddr){
    if(addr == NULL){
        printf("%s: Error >> addr is Null\n",__func__);
        exit(1);
    }
     addr->sin_family = AF_INET;
     addr->sin_port = htons(port);
     addr->sin_addr.s_addr = (saddr == NULL)?INADDR_ANY:inet_addr(saddr);
     bzero(addr->sin_zero,8); 
}

void clear_socket_addr(struct sockaddr_in *addr){
    bzero(addr,sizeof(struct sockaddr_in));
}

int32_t set_fcntl(int32_t fd,int32_t flags){
    int32_t tmp = fcntl(fd,F_GETFL);
    return fcntl(fd,F_SETFL,tmp|flags);
}

int32_t noblock_tcp_socket_server(void){

    struct sockaddr_in server_addr,client_addr;
    int32_t sin_size,recvbytes;

    int32_t sockfd,client_fd;
    char buf[BUFFER_SIZE];

    if((sockfd = socket(AF_INET,SOCK_STREAM,0)) == -1){
        perror("socket");
        exit(1);
    }
    
    config_socket_addr_afinet(&server_addr,PORT,"192.168.246.133");

    int32_t en = 1;
    setsockopt(sockfd,SOL_SOCKET,SO_REUSEADDR,&en,sizeof(en)); //可以重复使用本地地址进信绑定
    
    if(bind(sockfd,(struct sockaddr*)&server_addr,sizeof(struct sockaddr)) == -1){
        perror("bind");
        exit(0);
    }    

    if(listen(sockfd,MAX_QUE_CONN_NM) == -1 ){
        perror("listen");
        exit(1);
    }

    if(set_fcntl(sockfd,O_NONBLOCK) < 0){
         perror("set socket no block error\n");
         exit(1);
    }    

    while(1){
        sin_size = sizeof(struct sockaddr_in);

        do{
            if((client_fd = accept(sockfd,(struct sockaddr*)&client_addr,(uint32_t*)&sin_size)) >=0){
                printf("connected client: %s\n",inet_ntoa(client_addr.sin_addr));
                break;
            }

            if(errno != EAGAIN){
               printf("accept:%s\n", strerror(errno)); 
            }else{
                sleep(1);
            }
        }while(1);

      
        if((recvbytes = recv(client_fd,buf,BUFFER_SIZE,0)) < 0){
            perror("recv");
            exit(1);
        }  

        printf("recv msg: %s \n",buf);
    }
    close(client_fd);
    exit(1);
}

int32_t tcp_client_tx(const char* argv,const char* buf){
   int32_t sockfd,sendbytes;
   struct sockaddr_in server_addr;

   if((sockfd = socket(AF_INET,SOCK_STREAM,0)) == -1){
       perror("socket");
       exit(1);
   }
    
   config_socket_addr_afinet(&server_addr,PORT,argv);

   if(connect(sockfd, (struct sockaddr*)&server_addr,sizeof(struct sockaddr)) == -1){
       perror("connect");
       exit(1);
   }

   if((sendbytes =send(sockfd,buf,strlen(buf),0)) < 0){
       perror("send");
       exit(1);
   }
   close(sockfd);
   return 0;
}

int32_t select_tcp_server(void){
    struct sockaddr_in server_addr,client_addr;
    uint32_t sin_size,count;

    fd_set inset,tmp_inset;
    int32_t sockfd,client_fd,fd;
    char buf[BUFFER_SIZE];

    config_socket_addr_afinet(&server_addr,PORT,"192.168.246.133");

    if((sockfd = socket(AF_INET,SOCK_STREAM,0)) == -1){
        perror("socket");
        exit(1);
    }

    int32_t en = 1;
    setsockopt(sockfd,SOL_SOCKET,SO_REUSEADDR,&en,sizeof(en)); //可以重复使用本地地址进信绑定
    if(bind(sockfd,(struct sockaddr*)&server_addr,sizeof(struct sockaddr)) == -1){
        perror("error");
        exit(1);
    }

    if(listen(sockfd,MAX_QUE_CONN_NM) == -1){
        perror("listen");
        exit(1);
    }
    printf("listening ... ....\n");

    FD_ZERO(&inset);
    FD_SET(sockfd,&inset);

    while(1){
        tmp_inset = inset;
        sin_size = sizeof(struct sockaddr_in);
        memset(buf,0,strlen(buf));

        if(!(select(1024,&tmp_inset,NULL,NULL,NULL)>0)){
            perror("select");
        }

        for(fd = 0 ; fd < 1024 ; fd++){
            if(FD_ISSET(fd,&tmp_inset) >0){
                if(fd == sockfd){
                    if((client_fd = accept(sockfd,(struct sockaddr*)&client_addr,&sin_size)) == -1){
                        perror("accept");
                        exit(1);
                    }
                    FD_SET(client_fd,&inset);
                    printf("New con from %s\n",inet_ntoa(client_addr.sin_addr));
                }else{
                    if((count = recv(client_fd,buf,BUFFER_SIZE,0))>0){
                        printf("Msg: %s\n",buf);
                    }else{
                        close(fd);
                        FD_CLR(fd,&inset);
                        printf("Client fd left: %d \n",fd);
                    }
                }
            }
        }
    }
    close(fd);
    exit(0);
}

int32_t main(int argc,char* argv[]){
#ifdef MASTER
#ifdef NOBLOCK
    noblock_tcp_socket_server();
#else
    select_tcp_server();
#endif
#else 
    tcp_client_tx(argv[1],argv[2]);
#endif
}

根据其他人的代码修改，封装出来的

Makefile

.PHONY:all clean
SERVER=server
SRC=$(wildcard *.c)
OBJS=$(SRC:.c=.o)
CXX=gcc
CLIENT=client

all:
	make $(SERVER)
	make $(CLIENT)

$(SERVER):
	$(CXX) -g -Wall -DMASTER *.c -o $@ 

$(CLIENT):
	$(CXX) -g -Wall *.c -o $@ 



clean:
	rm -rf $(SERVER) $(OBJS) $(CLIENT)