linux进程间传递fd备忘

linux进程间传递fd备忘

(2012-11-08 16:50:15)

类： linux备忘

=========================================================
server.c
==========================================================
#include
#include
#include
#include

enum{false,true};
int send_fd(int fd,int fd_to_send);

int main()
{
 

       int sfd,cfd,size;
        struct sockaddr_un un;

        un.sun_family = AF_UNIX;
        strcpy(un.sun_path,"foo.socket");
        sfd = socket(AF_UNIX,SOCK_STREAM,0);

        size = offsetof(struct sockaddr_un,sun_path) + strlen(un.sun_path);
        remove("foo.socket");
        bind(sfd,(struct sockaddr *)&un,size);

        listen(sfd,5);
        while(true){
                cfd = accept(sfd,NULL,NULL);

                int fd;
                fd = open("test",O_RDWR,0600);
                send_fd(cfd,fd);
                close(fd);

                close(cfd);
        }
        close(sfd);
}

#define CONTROLLEN CMSG_LEN(sizeof(int))
static struct cmsghdr   *cmptr = NULL;

int send_fd(int fd,int fd_to_send)
{
        struct iovec    iov[1];
        struct msghdr   msg;
        char    buf[0];

        iov[0].iov_base = buf;
        iov[0].iov_len = 1;
        msg.msg_name    = NULL;
        msg.msg_namelen = 0;
        msg.msg_iov     = iov;
        msg.msg_iovlen = 1;


        if(cmptr == NULL && (cmptr = malloc(CONTROLLEN)) == NULL)
                return (-1);
        cmptr->cmsg_len         = CONTROLLEN;
        cmptr->cmsg_level       = SOL_SOCKET;
        cmptr->cmsg_type        = SCM_RIGHTS;
        *(int *)CMSG_DATA(cmptr)= fd_to_send;

        msg.msg_control         = cmptr;
        msg.msg_controllen      = CONTROLLEN;


        sendmsg(fd,&msg,0);

        return (0);
}

=========================================================================
client.c
=========================================================================
#include
#include
#include
#include

int recv_fd(int fd);
enum{false,true};

int main()
{
        int fd,size;
        char buf[512];
        int testfd;

        memset(buf,'\0',sizeof(buf));
        struct sockaddr_un un;

        un.sun_family = AF_UNIX;
        strcpy(un.sun_path,"foo.socket");
        fd = socket(AF_UNIX,SOCK_STREAM,0);

        size = offsetof(struct sockaddr_un,sun_path) + strlen(un.sun_path);
        connect(fd,(struct sockaddr *)&un,size);

        testfd = recv_fd(fd);
        read(testfd,buf,512);
        printf("%s\n",buf);

        close(fd);

}


#define CONTROLLEN CMSG_LEN(sizeof(int))
static struct cmsghdr   *cmptr = NULL;

int recv_fd(int fd)
{
        int     newfd;
        char    buf[0];
        struct iovec    iov[1];
        struct msghdr   msg;

        while(true){
                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;
                if(cmptr == NULL && (cmptr = malloc(CONTROLLEN)) == NULL){
                        return (-1);
                }
                msg.msg_control         = cmptr;
                msg.msg_controllen      = CONTROLLEN;

                recvmsg(fd,&msg,0);

                newfd = *(int *)CMSG_DATA(cmptr);

                return(newfd);
        }
}