linux进程之间传递句柄
參考網上的實現，進行了一點改進，本來想用FIFO實現的，后來發現不行，必須使用系統的sendmsg函數，代碼格式有點亂，不過功能可以實現，改天有空整理一下~~
講究看哈~
?
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include<sys/socket.h>
#include<netinet/in.h>
#include<arpa/inet.h>
#include <strings.h>
#include<sys/wait.h>
#include <string.h>
#include <errno.h>
#include <sys/un.h>
#include <sys/uio.h>
#include <fcntl.h>
#include <limits.h>
#include <sys/stat.h>
#define FIFO_NAME "/home/907684/my_fifo_file"
//#define BUFFER_SIZE PIPE_BUF
#define BUFFER_SIZE 10
#define TEN_MEG (1024*10)
#define CONTROLLEN sizeof (struct cmsghdr) + sizeof (int)
#define false 0
#define true 1
//異步寫打開FIFO，必須先有讀打開FIFO 否則會失敗！
int proccess_num=-1;
void show_struct_byte(const char * buf, int len)
{
?if (len <= 0) return;
?
?int i;
?printf("[%d]show struct len :%d. \r\n",proccess_num,len);
?printf("[%d]show struct as string :%s. \r\n *** \r\n",proccess_num,buf);
?
?for(i=0;i<len;i++)
?{
??printf("%d ",(int)(*buf++));
?}
?printf("\r\n[%d]finish show struct byte \r\n", proccess_num);
}
int send_sock_fd(int pipe_fd, int sock_fd)
{
????if (pipe_fd <0 || sock_fd < 0) return false;
?????
?????
????int bytes = 0,res;
????int return_flag=true;
????printf("[%d]enter send_sock_fd()... \r\n",proccess_num);
????/*????
????char buf_str[] = "firt recieved Client speaking!\n";
????//int ret = write(sock_fd, buf_str, sizeof(buf_str));
????//write() 異常判斷...
???
????struct cmsghdr *? cmptr = 0;
????struct msghdr msg;
????struct iovec? iov[1];
????char?? buf[2];
???
????iov[0].iov_base = buf;
????iov[0].iov_len? = 2;
????msg.msg_iov = iov;
????msg.msg_iovlen = 1;
????msg.msg_name = NULL;
????msg.msg_namelen = 0;
???
????cmptr = (struct cmsghdr *)malloc(sizeof(struct cmsghdr) + sizeof(int));
????cmptr->cmsg_level = SOL_SOCKET;
????cmptr->cmsg_type? = SCM_RIGHTS;
????cmptr->cmsg_len?? = sizeof(struct cmsghdr) + sizeof(int);
????*(int *)CMSG_DATA(cmptr) = sock_fd;
????msg.msg_control = cmptr;
????msg.msg_controllen = sizeof(struct cmsghdr) + sizeof(int);
????
????buf[1] = 0; buf[0] = 1;
????*/????
????
???? char tmpbuf[CONTROLLEN];
???? struct cmsghdr *cmptr = (struct cmsghdr *) tmpbuf;
???? struct iovec iov[1];
???? struct msghdr msg;
???? char buf[1];
???? iov[0].iov_base = buf;
???? iov[0].iov_len = 1;
???? msg.msg_iov = iov;
???? msg.msg_iovlen = 1;
???? msg.msg_name = NULL;
???? msg.msg_namelen = 0;
???? msg.msg_control = cmptr;
???? msg.msg_controllen = CONTROLLEN;
???? cmptr->cmsg_level = SOL_SOCKET;
???? cmptr->cmsg_type = SCM_RIGHTS;
???? cmptr->cmsg_len = CONTROLLEN;
???? *(int *)CMSG_DATA (cmptr) = sock_fd;
?
?????show_struct_byte((char *)&msg, sizeof(msg));?
????while (bytes < sizeof(msg))
??????? {
??????? ??printf("[%d]call write()... \r\n",proccess_num);
????
??????????? res = write(pipe_fd, (void *)&msg, sizeof(msg));
??????????? //res = sendmsg(pipe_fd,&msg,0);
???????????
??????????? printf("[%d]res = %d && errno = %d. \r\n",proccess_num,res,errno);
??????????? if (res == -1 )
??????????? {
??????????? ??if(errno == EAGAIN)
??????????? ??{
???????????????? printf("[%d]write no data. try later... \r\n",proccess_num);
???????????????? continue;
?????????????? }
?????????????? else
?????????????? {
???????????? ??printf("[%d]write error. exit! \r\n",proccess_num);
???????????? ?? fprintf(stderr, "Write error on pipe\r\n");
???????????? ??
???????????????? return_flag=false;?
???????????????? break;???????????? ?
?????????????? }
??????????? }
??????????? bytes += res;
??????????? printf("[%d]write data:%d bytes, sleep...\r\n",proccess_num,res);
??????????? //sleep(9);
??????? }
??????? printf("[%d]Total %d bytes send to fifo. send sock_fd:%d. sizeof(msg):%d \r\n",proccess_num,bytes, sock_fd, sizeof(msg));
??????? sleep(5);
???????
??????? //free(cmptr);
??????? //close(sock_fd); //NOT close?
??????? //close(pipe_fd); //NOT close?
?
????return return_flag;
}
int read_sock_fd(int pipe_fd, int* sock_fd)
{
????if (pipe_fd < 0 || sock_fd < 0) return false;
?????
????int bytes = 0, res;
????int return_flag = true;
????printf("[%d]enter read_sock_fd()... \r\n",proccess_num);
????/*
????//get client fd
????char buf[2];
????int newfd = -1;
????struct iovec?? iov[1];
????struct msghdr? msg;
????struct cmsghdr * cmptr = (struct cmsghdr *)malloc(sizeof(struct cmsghdr) + sizeof(int));
????
????iov[0].iov_base = buf;
????iov[0].iov_len? = sizeof(buf);
????msg.msg_iov???? = iov;
????msg.msg_iovlen? = 1;
????msg.msg_name??? = NULL;
????msg.msg_namelen = 0;
????msg.msg_control = cmptr;
????msg.msg_controllen = sizeof(struct cmsghdr) + sizeof(int);
????*/
????
???? char tmpbuf[CONTROLLEN];
???? struct cmsghdr *cmptr = (struct cmsghdr *) tmpbuf;
???? struct iovec iov[1];
???? struct msghdr msg;
???? char buf[1];
???? iov[0].iov_base = buf;
???? iov[0].iov_len = sizeof (buf);
???? msg.msg_iov = iov;
???? msg.msg_iovlen = 1;
???? msg.msg_name = NULL;
???? msg.msg_namelen = 0;
???? msg.msg_control = cmptr;
???? msg.msg_controllen = CONTROLLEN;
???
??????? printf("[%d] loop call read() fifo... \r\n", proccess_num);
????while (bytes < sizeof(msg))
??????? {
??????? ??res = read(pipe_fd, &msg, sizeof(msg));
??????? ??//res = recvmsg(pipe_fd,&msg,0);
??????? ??sleep(2);
??????????? printf("[%d]res = %d && errno = %d. \r\n", proccess_num,res,errno);
??????????? if (res == -1 )
??????????? {
??????????? ??if(errno == EAGAIN)
??????????? ??{
???????????????? //printf("read no data. try later... \r\n");
???????????????? continue;
?????????????? }
?????????????? else
?????????????? {
???????????? ??printf("[%d]read error. exit! \r\n",proccess_num);
???????????? ?? fprintf(stderr, "Write error on pipe\r\n");
???????????????? return_flag = false;??????
???????????????? break;??????? ?
?????????????? }
??????????? }
??????????? bytes += res;
??????????? printf("[%d]read data:%d bytes.\r\n",proccess_num,res);
??????????? //sleep(9);
??????? }
??????? printf("[%d]%d bytes read from fifo. sizeof(msg):%d \r\n",proccess_num,bytes,sizeof(msg));
???????
??????? //get client socket
??????? if (return_flag)
??????? {
??????? ?/*
??????? ?printf("[%d]read fifo succeed. pase client fd.\r\n",proccess_num);
??????? ?printf("[%d]*(int*)CMSG_DATA(cmptr):%d,cmptr:%d.\r\n",proccess_num,*(int*)CMSG_DATA(cmptr),cmptr);
??show_struct_byte((char *)&msg, sizeof(msg));?
???
??????? ?*sock_fd = *(int*)CMSG_DATA(cmptr);
??????? ?*/
??????? ?
??????? ?printf("[%d]*(int*)CMSG_DATA(cmptr):%d,cmptr:%d.\r\n",proccess_num,*(int *)CMSG_DATA (cmptr),cmptr);
??????? ?show_struct_byte((char *)&msg, sizeof(msg));?
??????? ?*sock_fd = *(int *)CMSG_DATA (cmptr);
???
?????printf("[%d]CMSG_FIRSTHDR(&msg) ret:%d (should not be 0!) \r\n", proccess_num,CMSG_FIRSTHDR(&msg));
???
??????? }
??????? else
??????? {
??????? ?printf("[%d]read fifo failed. set sock_fd = -1. \r\n",proccess_num);
??????? ?*sock_fd = -1;
??????? ?}
??????? printf("[%d]get client fd:%d.\r\n",proccess_num,*sock_fd);
??????? //sleep(5);
??????? close(pipe_fd);
??????? //close(sock_fd); //NOT close?
??????? //free(cmptr);
?return return_flag;
}
int init_fifo_write()
{
??//***** fifo *****
??? int write_pipe_fd;
??? int res;
??? int open_mode = O_WRONLY|O_NONBLOCK;
??? int bytes = 0;
??? //char buffer[BUFFER_SIZE + 1] = "hello";
??? if (access(FIFO_NAME, F_OK) == -1)
??? {
??????? res = mkfifo(FIFO_NAME, 0777);
??????? if (res != 0)
??????? {
??????????? fprintf(stderr, "Could not create fifo %s \r\n", FIFO_NAME);
??????????? return -1;
??????? }
??? }
??? printf("[%d] write opeining FIFO :%s? \r\n", proccess_num, FIFO_NAME);
??? //printf("fifo buffer size:%d",BUFFER_SIZE);
???
??? int read_fd = open(FIFO_NAME, O_RDONLY | O_NONBLOCK);
??? if (read_fd == -1)
??? {
??? ??printf("[%d]read open fifo file failed. exit. \r\n",proccess_num);
??????? return -1;
??? } ??
???
??? write_pipe_fd = open(FIFO_NAME, O_WRONLY|O_NONBLOCK);???
??? if (write_pipe_fd == -1)
??? {
??? ??printf("[%d]write open fifo file failed. exit. \r\n",proccess_num);
??????? return -1;
??? } ?
??? printf("[%d]Process %d result %d\r\n",proccess_num, getpid(), write_pipe_fd);
???
??? return write_pipe_fd;?
???
?? }
int init_fifo_read()
{
??? int read_pipe_fd;
??? int res;
??? int open_mode = O_RDONLY|O_NONBLOCK;
??? char buffer[BUFFER_SIZE + 1];
??? int bytes = 0;
??? memset(buffer, 0, sizeof(buffer));
??? printf("[%d] read opeining FIFO :%s? \r\n", proccess_num, FIFO_NAME);
??? //printf("fifo buffer size:%d",BUFFER_SIZE);
??? read_pipe_fd = open(FIFO_NAME, O_RDONLY|O_NONBLOCK);
??? printf("Process %d result %d\r\n", getpid(), read_pipe_fd);
??? if (read_pipe_fd == -1)
??? {
??? ??printf("read open fifo file failed. exit. \r\n");
??????? return -1;
??? } ?
??? printf("Process %d result %d\r\n", getpid(), read_pipe_fd);
???
??? return read_pipe_fd;?
?}
?//***** fifo *****
//************************ send socket fd
static struct sockaddr_un addr = {0};?
static int s_create_usockfd()
{
?static char* path = "/home/907684/test/fd_send/share_fd";
?int sockfd;?
?addr.sun_family = AF_UNIX;????
?strcpy(addr.sun_path, path);
?sockfd = socket(PF_UNIX, SOCK_DGRAM, 0);????
?if(sockfd == -1)
?{
??printf("create unix sockfd failed, %d, %s\n", errno, strerror(errno));????????
??return 0;????
?}????
?else
?{
??printf("create unix sockfd ok\n");????
?}?
//還需要使用bind函數來創建S_IFSOCK類型文件!!!!!!
//否則可能提示文件不存在!!!
?return sockfd;
}?
static int s_send_fd(int sockfd, int fd)
{
?struct msghdr msg = {0};
?char ccmsg[CMSG_SPACE(sizeof(fd))];????
?struct cmsghdr* cmsg;???? int rv;?
?msg.msg_name = (struct sockaddr*)&addr;????
?msg.msg_namelen = sizeof(addr);?
?msg.msg_control = ccmsg;
?msg.msg_controllen = sizeof(ccmsg);?
?cmsg = CMSG_FIRSTHDR(&msg);????
?cmsg->cmsg_level = SOL_SOCKET;????
?cmsg->cmsg_type = SCM_RIGHTS;
?cmsg->cmsg_len = CMSG_LEN(sizeof(fd));?
?*(int*)CMSG_DATA(cmsg) = fd;????
?msg.msg_control = ccmsg;
?msg.msg_controllen = cmsg->cmsg_len;????
?msg.msg_flags = 0;?
?printf("sendmsg file fd[%d] to socket fd[%d]\n",fd, sockfd);
?
?rv = (sendmsg(sockfd, &msg, 0) != -1);????
?printf("sendmsg return %d \r\n",rv);
?if(rv)
?{
??printf("sendmsg ok, file fd is %d\n", fd);????????
??close(fd);????
?}????
?else
?{
??printf("sendmsg failed to socket fd[%d], errno[%d], error str:%s\n", sockfd, errno, strerror(errno));????
?}?
?printf("send fd[%d] to shared file finish.\r\n", fd);
?return rv;
}?
int get_fd_to_send()
{
?char * file_shared_path = "/home/907684/test/fd_send/file_shared.txt";
?int sfd = open(file_shared_path, O_CREAT|O_RDWR|O_TRUNC, 0644);?
?return sfd;?
}
//************************ send socket fd
?
//************************ recv socket fd
static int r_create_usockfd(char* path)
{
??? struct sockaddr_un addr = {0};
??? int opt = 1;
??? int fd;
?
??? addr.sun_family = AF_UNIX;
?
??? unlink(path);
??? strcpy(addr.sun_path, path);?
?
??? fd = socket(PF_UNIX, SOCK_DGRAM, 0);
?
??? if(bind(fd, (struct sockaddr*)&addr, sizeof(addr))){
??????? printf("[%d]recv bind failed, %d, %s\n",proccess_num, errno, strerror(errno));
??? }
??? else{
??????? printf("[%d]recv bind ok\n", proccess_num);
??? }
?
??? return fd;
}
?
static int r_recv_fd(int fd)
{
??? struct msghdr msg = {0};
??? int rv = 0;
??? int cfd = -1;
??? char ccmsg[CMSG_SPACE(sizeof(cfd))];
??? struct cmsghdr* cmsg;
?
??? msg.msg_control = ccmsg;
??? msg.msg_controllen = sizeof(ccmsg);
?
??? while(1){
??????? rv = recvmsg(fd, &msg, 0);
??????? if(rv == -1){
??????????? printf("recvmsg failed, return %d, %d, %s\n", rv, errno, strerror(errno));
??????????? sleep(1);
??????? }
??????? else{
??????????? printf("[%d]recvmsg ok.\n",proccess_num);
??????????? break;
??????? }
??? }
?
??? cmsg = CMSG_FIRSTHDR(&msg);
??? int client_fd=*(int*)CMSG_DATA(cmsg);
??? printf("[%d]recieved client socket fd[%d].\n",proccess_num,client_fd);
??? return client_fd;
}
int get_share_fd()
{
??? int sfd = socket(AF_INET, SOCK_STREAM, 0);
??? sfd = socket(AF_INET, SOCK_STREAM, 0);? // waste some fd
?
??? static char* path = "/home/907684/test/fd_send/share_fd";
??? int sockfd = r_create_usockfd(path);
??? int cfd = r_recv_fd(sockfd);
??? return cfd;
}
void send_msg_to_client(int cfd)
{
??? char* str = "This is the second proccess speaking.\n";
??? printf("[%d]write string to recieved file fd[%d]. string[%s]\r\n",proccess_num, cfd,str);
??? int res = write(cfd, str, strlen(str));
??? if(res<0)
??? {
??????? printf("write error. res:%d\r\n",res);
??? }
}
//************************ recv socket fd
?
int main(int argc, char ** argv)
{
?pid_t pid;
?char *msg;
?int n,i,j;
?int exit_code;
?int res=0,WR_fifo_fd,RD_fifo_fd;
?
?//***** socket *****
?int listenfd,connfd;
?socklen_t clilen;
?struct sockaddr_in cliaddr,servaddr;
?
?listenfd = socket(AF_INET,SOCK_STREAM,0);
?
?//set non_block
?int flags = fcntl(listenfd, F_GETFL, 0);
?if( -1 == fcntl(listenfd, F_SETFL, flags|O_NONBLOCK) )
?{
??printf("Set NONBLOCK for socket fd %d failed", listenfd);
??exit(1);
?}
?
?bzero(&servaddr,sizeof(servaddr));
?servaddr.sin_family = AF_INET;
?servaddr.sin_addr.s_addr = htonl(INADDR_ANY);
?servaddr.sin_port = htons(8060);
?
?bind(listenfd, (struct sockaddr*)&servaddr, sizeof(struct sockaddr));
?listen(listenfd, 1024);
?//***** socket *****
?
?printf("start.\r\n");
?
?for( i=0;i<3;i++)
?{
??pid=fork();
??proccess_num=i;
??if(pid == 0 || pid == -1)
??{
???printf(" not fork.\r\n");
???break;
??}
?}
?
?if (pid == -1)
?{
??printf("fork error.\r\n");
??exit(1);
?}
?else if(pid == 0)
?{
??//child procces.
??//********
??printf("[%d] enter for...\r\n",proccess_num);
??
??if (proccess_num == 1) // 1 write fifo
??{
???printf("[%d] init_fifo_write.\r\n",proccess_num);
???res = init_fifo_write();
???if (res == -1)
???{
????printf("init fifo write failed. exit.");
????exit(EXIT_FAILURE);
????}
???WR_fifo_fd = res;
??}
??
??if (proccess_num == 2) // 2 read fifo
??{
???printf("[%d] init_fifo_read. \r\n",proccess_num);
???res = init_fifo_read();
???if (res == -1)
???{
????printf("init fifo read failed. exit.");
????exit(EXIT_FAILURE);
????}
???RD_fifo_fd = res;
??}
??
??printf("[%d] child loop call accept() .\r\n",proccess_num);
??for(;;)
??{
????//printf("[%d] sleep 2 sec.\r\n",proccess_num);
????sleep(1);
????//read fifo .
????if (proccess_num == 2) // 2 read fifo
????{
?????int clifd=-1;
?????//printf("[%d] fifo read.\r\n",proccess_num);
?????int shared_fd;
?????shared_fd = get_share_fd();
?????send_msg_to_client(shared_fd);
?????/*?????
?????res = read_sock_fd(RD_fifo_fd,&clifd);
?????if (res != true)
?????{
??????printf("[%d]read socket fd failed! \r\n",proccess_num);
?????}
?????else
?????{
??????printf("[%d]read socket fd succeed! fd:%d \r\n",proccess_num,clifd);
??????//send some data to client
??????printf("send some data to client! \r\n");
??????char buf_str[] = "This is second recieved Client!\n";
??????int ret = write(clifd, buf_str, sizeof(buf_str));??
??????printf("write ret:%d. buf_str size:%d \r\n", ret,sizeof(buf_str));????
?????
??????printf("[%d] close client fd:%d \r\n",proccess_num,clifd);
??????time_t t;
??????time(&t);
??????printf("[%d]time: %ld\n",proccess_num,t);
??????close(clifd);
?????}*/
????}
????else if (proccess_num == 1) // 1 write fifo
????{
?????clilen = sizeof(cliaddr);
?????//printf("[%d] child call accept() .\r\n",proccess_num);
?????if((connfd = accept(listenfd,(struct sockaddr*)&cliaddr, &clilen)) < 0)
?????{
??????//printf("[%d] accept failed. fd: %d.\r\n",proccess_num,connfd);
??????if(errno == EAGAIN)
??????{
???????//printf("[%d] accept EAGAIN.continue...\r\n",proccess_num);
???????continue;
??????}
??????else
??????{
???????printf("[%d] accept error.\r\n",proccess_num);
???????exit(1);
??????}
?????}
?????else
?????{
??????printf("[%d] accept succeed. fd:%d \r\n",proccess_num,connfd);
??????//sleep(10);
??????
??????/*if (1) // 1 write fifo
??????{
???????printf("[%d] fifo write.\r\n",proccess_num);
???????//send socket fd to other proccess.
???????res = send_sock_fd(WR_fifo_fd, connfd);
???????if (res != true)
????????printf("[%d]send socket fd %d failed! sleep 10...\r\n",proccess_num,connfd);
???????else
????????printf("[%d]send socket fd %d succeed! sleep 10...\r\n",proccess_num,connfd);
???????sleep(10);
??????}*/
??????//send socket fd to other proccess!
??????int local_sockfd = s_create_usockfd();????
??????//int client_fd = get_fd_to_send(); ?
??????int client_fd = connfd;
??????s_send_fd(local_sockfd,client_fd);?
??????
??????
??????printf("[%d]send socket fd[%d] to other proccess finish. close socket fd. \r\n",proccess_num,connfd);
??????close(connfd);?//NOT close??
??????time_t t;
??????time(&t);
??????printf("[%d]time: %ld\n",proccess_num,t);?
?????}
????}
??//********
??//exit(0);
??}
?}
?else
?{
??//parent.
??printf("parent wait...\r\n");
??while(1);
??printf("parent exit.\r\n");
??exit(0);
??}
?
?}
?
?
?
?
client的代碼：
#include <stdio.h>
#include <sys/socket.h>
#include <string.h>
#include <netinet/in.h>
#define BUF_LEN????50
/************關于本文檔********************************************
*filename: client.c
*purpose: 這是在Linux下用C語言寫的一個簡單sokcet客戶端，用來向共享socket發送消息，以測試共享socket
進程接收消息情況。
使用方法：./client server-ip
?
更多開源軟件，請訪問http://fossd.net/?fromuid=32
*********************************************************************/
?#include<time.h>
int main(int argc,char* argv[])
{
? if (!argv[1])
? {
? ?printf(" useage: ./client?? [server ip] \r\n eixt. \r\n");
?return -1;
? ?}
?
?? int ret;
?? int fd;
??
??? int i,len;
?? struct sockaddr_in servaddr;
?? char buf[BUF_LEN];
?? fd_set writefds;
?? strcpy(buf,"hi, i am client\n");
?? fd =? socket(AF_INET,SOCK_STREAM,0);
?? if(fd <= 0)
?? {
?? ?? perror("socket");
?? return fd;
?? }
?? servaddr.sin_family = AF_INET;
?? servaddr.sin_port = htons(8060);
?? servaddr.sin_addr.s_addr = inet_addr(argv[1]);
?? printf("connect to server... \r\n");
?? ret = connect(fd,(struct sockaddr*)&servaddr,sizeof(servaddr));
?? if(ret != 0)
?? {
?? ?? perror("connect");
?? return ret;
?? }
?? bzero(buf,BUF_LEN);
?? sprintf(buf,"%d hi,i came from client",i);
?? len = strlen(buf);
?? ret = write(fd,buf,BUF_LEN);
?? printf("write ret:%d \r\n",ret);
?? if (ret <= 0)
?? {
?? ?printf("write ret <= 0 \r\n");
?? }
?? char read_buf[1024]={0};
?? if(read(fd, read_buf, 1024) > 0)
?? {
?? ?printf("read data:%s \r\n", read_buf? );
? ?}
?? else
?? {
?? ?printf("read ret <= 0 \r\n");
?? ?}
??
?? printf("read finish. exit.\r\n");
??
?? time_t t;
?? time(&t);
?? printf("time: %ld\n",t);
/*
?? while(1)
?? {
?? ??? int i,len,ret;
?
?????? for(i = 0; i < 2000; i++)
?????? {
??? ??? bzero(buf,BUF_LEN);
???? sprintf(buf,"%d hi,i came from client",i);
???? len = strlen(buf);
????
???? ret = write(fd,buf,BUF_LEN);
?????? }
?????? sleep(3);
?? }
? */
}
?
?
?
轉載于:https://www.cnblogs.com/kai-jiang/p/3235096.html
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