0725，进程间传递文件描述符，socketpair + sendmsg/recvmsg

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上课喵：

pipe匿名管道的问题

#include <func.h>int main()
{int fds[2];pipe(fds);pid_t pid=fork();if(pid>0){ //fatherclose(fds[0]);//close readint fd=open("file2.txt",O_RDONLY);printf("father: fds[1]:%d\n",fds[1]);write(fds[1],&fd,sizeof(fd));wait(NULL);close(fd);}else{   //sonclose(fds[1]);//close erint chilfd=-1;read(fds[0],&chilfd,sizeof(chilfd));  //read baba pipeprintf("chilefd %d.fds [0]:%d\n",chilfd,fds[0]);char buff[100]={0};read(chilfd,buff,sizeof(buff));printf("buff  %s.\n",buff);}return 0;
}

writev

#include <func.h>
#include <sys/uio.h>int main()
{char buff[]="love";char buff2[]="xixi";int fd=open("file2.txt",O_RDWR|O_CREAT,0664);if(fd==-1){};struct iovec iov[2];iov[0].iov_base=buff;iov[0].iov_len=strlen(buff);iov[1].iov_base=buff2;iov[1].iov_len=strlen(buff2);int ret=writev(fd,iov,2);printf("ret :%d \n",ret);close(fd);return 0;
}

readv

#include <func.h>
#include <sys/uio.h>int main()
{char buff[6]={0};char buff2[6]={0};int fd=open("file2.txt",O_RDWR);if(fd==-1){};struct iovec iov[2];iov[0].iov_base=buff;/* iov[0].iov_len=strlen(buff); */iov[0].iov_len=sizeof(buff);iov[1].iov_base=buff2;iov[1].iov_len=sizeof(buff2);int ret=readv(fd,iov,2);printf("ret :%d \n",ret);printf("buff:%s \n",buff);printf("buff2:%s \n",buff2);close(fd);return 0;
}

结构体struct msghdr的发送和接收实现

真是酣畅淋漓的CP

代码改好了！！
./wr33: sendmsg: Bad file descriptor
嘿嘿~~~因为没有文件所以打开失败了！！！聪明小辉

#include <func.h>
#include <sys/uio.h>int sendFd(int pipefd,int fd){//buid 2 groupchar buff[6]="hellp";struct iovec iov;memset(&iov,0,sizeof(iov));iov.iov_base=buff;iov.iov_len=sizeof(buff);//build 3 groupint len=CMSG_LEN(sizeof(fd));struct cmsghdr* cmsg=(struct cmsghdr*)calloc(1,len);cmsg->cmsg_len=len;cmsg->cmsg_level=SOL_SOCKET;cmsg->cmsg_type=SCM_RIGHTS;int * p=(int*)CMSG_DATA(cmsg);*p=fd;// buid msghdrstruct msghdr msg;memset(&msg,0,sizeof(msg));msg.msg_iov=&iov;msg.msg_iovlen=1;msg.msg_control=cmsg;//传递文件描述msg.msg_controllen=len;int ret=sendmsg(pipefd,&msg,0);printf("sendmsg ret: %d\n",ret);if(ret==-1){error(1,errno,"sendmsg");}free(cmsg);return 0;
}int recvFd(int pipefd,int *pfd){//buid 2 groupchar buff[6]={0};struct iovec iov;memset(&iov,0,sizeof(iov));iov.iov_base=buff;iov.iov_len=sizeof(buff);//3 groupint len=CMSG_LEN(sizeof(int));struct cmsghdr* cmsg=(struct cmsghdr*)calloc(1,len);cmsg->cmsg_len=len;cmsg->cmsg_level=SOL_SOCKET;cmsg->cmsg_type=SCM_RIGHTS;struct msghdr msg;memset(&msg,0,sizeof(msg));msg.msg_iov=&iov;msg.msg_iovlen=1;msg.msg_control=cmsg;//传递文件描述符msg.msg_controllen=len;int ret =recvmsg(pipefd,&msg,0);if(ret==-1){error(1,errno,"recvmsg");}int* p=(int*)CMSG_DATA(cmsg);printf("buff: %s\n",buff);*pfd=*p;//传给外籍的指针(读取文件描述符的值)return 0;
}int main()
{int fds[2];socketpair(AF_LOCAL,SOCK_STREAM,0,fds);pid_t pid=fork();if(pid>0){ //fatherclose(fds[0]);//close readint fd=open("file1.txt",O_RDONLY);printf("father fd:%d\n",fd);/* write(fds[1],&fd,sizeof(fd)); */sendFd(fds[1],fd);wait(NULL);close(fd);}else{   //sonclose(fds[1]);//close erint chilfd=-1;/* read(fds[0],&chilfd,sizeof(chilfd));  //read baba pipe */recvFd(fds[0],&chilfd);printf("chilefd %d.fds [0]:%d\n",chilfd,fds[0]);char buff[100]={0};read(chilfd,buff,sizeof(buff));printf("buff  %s.\n",buff);}return 0;
}

 进程池框架的搭建

作业：

01：参考我们上课的代码: 让子进程A打开一个文件, 把这个文件描述符信息发给父进程B, 让父进程B在这个文件上能写一个字符串. 

好像没什么用？？？？？？

#include <func.h>
#include <sys/uio.h>int sendFd(int pipefd,int fd){//buid 2 groupchar buff[6]={0};struct iovec iov;memset(&iov,0,sizeof(iov));iov.iov_base=buff;iov.iov_len=sizeof(buff);//build 3 groupint len=CMSG_LEN(sizeof(fd));struct cmsghdr* cmsg=(struct cmsghdr*)calloc(1,len);cmsg->cmsg_len=len;cmsg->cmsg_level=SOL_SOCKET;cmsg->cmsg_type=SCM_RIGHTS;int * p=(int*)CMSG_DATA(cmsg);*p=fd;// buid msghdrstruct msghdr msg;memset(&msg,0,sizeof(msg));msg.msg_iov=&iov;msg.msg_iovlen=1;msg.msg_control=cmsg;//传递文件描述msg.msg_controllen=len;int ret=sendmsg(pipefd,&msg,0);if(ret==-1){error(1,errno,"sendmsg");}free(cmsg);return 0;
}int recvFd(int pipefd,int *pfd){//buid 2 groupchar buff[6]={0};struct iovec iov;memset(&iov,0,sizeof(iov));iov.iov_base=buff;iov.iov_len=sizeof(buff);//3 groupint len=CMSG_LEN(sizeof(int));struct cmsghdr* cmsg=(struct cmsghdr*)calloc(1,len);cmsg->cmsg_len=len;cmsg->cmsg_level=SOL_SOCKET;cmsg->cmsg_type=SCM_RIGHTS;struct msghdr msg;memset(&msg,0,sizeof(msg));msg.msg_iov=&iov;msg.msg_iovlen=1;msg.msg_control=cmsg;//传递文件描述符msg.msg_controllen=len;int ret =recvmsg(pipefd,&msg,0);if(ret==-1){error(1,errno,"recvmsg");}int* p=(int*)CMSG_DATA(cmsg);*pfd=*p;//传给外籍的指针(读取文件描述符的值)return 0;
}int main()
{int fd[2];int err=socketpair(AF_LOCAL,SOCK_STREAM,0,fd);if(err==-1){error(1,errno,"sockpair");}int pid=fork();switch (pid){case -1:error(1,errno,"fork");break;case 0:{close(fd[0]);printf("child process:%d\n",getpid());int pfd;recvFd(fd[1],&pfd);char buff[]="我恨你我恨你我恨你！！！！！\n";write(pfd,buff,sizeof(buff));close(pfd);break;}default:{close(fd[1]);int filefd=open("file2.txt",O_RDWR);if(filefd==-1){error(1,errno,"open");}sendFd(fd[0],filefd);break;}      }return 0;
}

所以那狗东西要怎么打印出来可恶！！！！ 

02：仿照我们上课写的进程池, 自己手写(不要直接复制)一个进程池代码。

过

抄抄抄：

02：使用select编写聊天室程序：客户端和服务端使用tcp通信；服务端可以处理新客户端的连接和转发消息；客户端可以连入服务端并发送消息。

哥们发现少一个右括号直接傻眼了喵

xiaohuichen@xiaohuichen-virtual-machine:~/001/724$ cat douqusi.c
#include <func.h>
#define IP1  "192.168.235.128"
#define PORT1 8080int main()
{struct sockaddr_in addr;addr.sin_family=AF_INET;addr.sin_port=htons(PORT1);addr.sin_addr.s_addr=inet_addr(IP1);int lifd=socket(AF_INET,SOCK_STREAM,0);bind(lifd,(struct sockaddr *)&addr,sizeof(struct sockaddr));listen(lifd,100);int ac_fd[1000];int ac_num=0;char buf[256];char buf_sent[256];fd_set readfds;FD_ZERO(&readfds);int fd_max;FD_SET(lifd,&readfds);fd_max=lifd;fd_set old_fds=readfds;printf("listenning\n");while(1){readfds=old_fds;select (fd_max+1,&readfds,NULL,NULL,NULL);if(FD_ISSET(lifd,&readfds)){ac_fd[ac_num]=accept(lifd,NULL,NULL);FD_SET(ac_fd[ac_num],&old_fds);if(ac_fd[ac_num]>fd_max){fd_max=ac_fd[ac_num];}ac_num++;printf("welcome user%d \n",ac_fd[ac_num-1]);}for(int i=0;i<ac_num;i++){if(FD_ISSET(ac_fd[i],&readfds)){int a=recv(ac_fd[i],buf,256,0);if(a==0){close(ac_fd[i]);}}sprintf(buf_sent,"user%d:%s",ac_fd[i],buf);for(int j=0;j<ac_num;j++){send(ac_fd[j],buf_sent,strlen(buf_sent)+1,0);}}}return 0;
}

HTTP:（咳咳，是我不知道怎么跑然后连了一个客户端喵）

#include <func.h>
#define IP1  "192.168.235.128"
#define PORT1 8080struct sockaddr* addr_create(const char* ip,int  port ){struct sockaddr_in* addr=(struct sockaddr_in*)malloc(sizeof(struct sockaddr_in));memset(addr,0,sizeof(*addr));addr->sin_family=AF_INET;addr->sin_port=htons(port);addr->sin_addr.s_addr=inet_addr(ip);return (struct sockaddr*)addr;
}int main()
{int sofd=socket(AF_INET,SOCK_STREAM,0);if(sofd==-1){error(1,errno,"socket");}int on=1;int ret=setsockopt(sofd,SOL_SOCKET,SO_REUSEADDR,&on,sizeof(on));if(ret==-1){error(1,errno,"setsoclopt");}struct sockaddr* addr=addr_create(IP1,PORT1);ret=bind(sofd,addr,sizeof(*addr));if(ret==-1){error(1,errno,"bind");}ret=listen(sofd,1);while(1){int peerfd=accept(sofd,NULL,NULL);char buff[4096]={0};ret=recv(peerfd,buff,sizeof(buff),0);printf("\nrecv: %d.bytes \n",ret);printf("----%s\n",buff);char response[4096]={0};const char* start_line="HTTP/1.1 200 ok\r\n";const char* headers="Server:MyHttpServer1.0\r\n""Connection:keep-aliave\r\n""Conntent-Type:text/html\r\n""Content-Length:";const char* empty_line="\r\n";const char* body="<html><head>This is a test</head><body>hello,client</body></html>";sprintf(response,"%s%s%ld\r\n%s%s",start_line,headers,strlen(body),empty_line,body);send(peerfd,response,strlen(response),0);}close(sofd);return 0;
}