This gives us more freedom about the fd that is passed to qemu, allowing us to e.g. pass sockets. Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
		
			
				
	
	
		
			137 lines
		
	
	
		
			3.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			137 lines
		
	
	
		
			3.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
 | 
						|
 * SCM_RIGHTS with unix socket help program for test
 | 
						|
 *
 | 
						|
 * Copyright IBM, Inc. 2013
 | 
						|
 *
 | 
						|
 * Authors:
 | 
						|
 *  Wenchao Xia    <xiawenc@linux.vnet.ibm.com>
 | 
						|
 *
 | 
						|
 * This work is licensed under the terms of the GNU LGPL, version 2 or later.
 | 
						|
 * See the COPYING.LIB file in the top-level directory.
 | 
						|
 */
 | 
						|
 | 
						|
#include "qemu/osdep.h"
 | 
						|
#include <sys/socket.h>
 | 
						|
#include <sys/un.h>
 | 
						|
 | 
						|
/* #define SOCKET_SCM_DEBUG */
 | 
						|
 | 
						|
/*
 | 
						|
 * @fd and @fd_to_send will not be checked for validation in this function,
 | 
						|
 * a blank will be sent as iov data to notify qemu.
 | 
						|
 */
 | 
						|
static int send_fd(int fd, int fd_to_send)
 | 
						|
{
 | 
						|
    struct msghdr msg;
 | 
						|
    struct iovec iov[1];
 | 
						|
    int ret;
 | 
						|
    char control[CMSG_SPACE(sizeof(int))];
 | 
						|
    struct cmsghdr *cmsg;
 | 
						|
 | 
						|
    memset(&msg, 0, sizeof(msg));
 | 
						|
    memset(control, 0, sizeof(control));
 | 
						|
 | 
						|
    /* Send a blank to notify qemu */
 | 
						|
    iov[0].iov_base = (void *)" ";
 | 
						|
    iov[0].iov_len = 1;
 | 
						|
 | 
						|
    msg.msg_iov = iov;
 | 
						|
    msg.msg_iovlen = 1;
 | 
						|
 | 
						|
    msg.msg_control = control;
 | 
						|
    msg.msg_controllen = sizeof(control);
 | 
						|
 | 
						|
    cmsg = CMSG_FIRSTHDR(&msg);
 | 
						|
 | 
						|
    cmsg->cmsg_len = CMSG_LEN(sizeof(int));
 | 
						|
    cmsg->cmsg_level = SOL_SOCKET;
 | 
						|
    cmsg->cmsg_type = SCM_RIGHTS;
 | 
						|
    memcpy(CMSG_DATA(cmsg), &fd_to_send, sizeof(int));
 | 
						|
 | 
						|
    do {
 | 
						|
        ret = sendmsg(fd, &msg, 0);
 | 
						|
    } while (ret < 0 && errno == EINTR);
 | 
						|
 | 
						|
    if (ret < 0) {
 | 
						|
        fprintf(stderr, "Failed to send msg, reason: %s\n", strerror(errno));
 | 
						|
    }
 | 
						|
 | 
						|
    return ret;
 | 
						|
}
 | 
						|
 | 
						|
/* Convert string to fd number. */
 | 
						|
static int get_fd_num(const char *fd_str, bool silent)
 | 
						|
{
 | 
						|
    int sock;
 | 
						|
    char *err;
 | 
						|
 | 
						|
    errno = 0;
 | 
						|
    sock = strtol(fd_str, &err, 10);
 | 
						|
    if (errno) {
 | 
						|
        if (!silent) {
 | 
						|
            fprintf(stderr, "Failed in strtol for socket fd, reason: %s\n",
 | 
						|
                    strerror(errno));
 | 
						|
        }
 | 
						|
        return -1;
 | 
						|
    }
 | 
						|
    if (!*fd_str || *err || sock < 0) {
 | 
						|
        if (!silent) {
 | 
						|
            fprintf(stderr, "bad numerical value for socket fd '%s'\n", fd_str);
 | 
						|
        }
 | 
						|
        return -1;
 | 
						|
    }
 | 
						|
 | 
						|
    return sock;
 | 
						|
}
 | 
						|
 | 
						|
/*
 | 
						|
 * To make things simple, the caller needs to specify:
 | 
						|
 * 1. socket fd.
 | 
						|
 * 2. path of the file to be sent.
 | 
						|
 */
 | 
						|
int main(int argc, char **argv, char **envp)
 | 
						|
{
 | 
						|
    int sock, fd, ret;
 | 
						|
 | 
						|
#ifdef SOCKET_SCM_DEBUG
 | 
						|
    int i;
 | 
						|
    for (i = 0; i < argc; i++) {
 | 
						|
        fprintf(stderr, "Parameter %d: %s\n", i, argv[i]);
 | 
						|
    }
 | 
						|
#endif
 | 
						|
 | 
						|
    if (argc != 3) {
 | 
						|
        fprintf(stderr,
 | 
						|
                "Usage: %s < socket-fd > < file-path >\n",
 | 
						|
                argv[0]);
 | 
						|
        return EXIT_FAILURE;
 | 
						|
    }
 | 
						|
 | 
						|
 | 
						|
    sock = get_fd_num(argv[1], false);
 | 
						|
    if (sock < 0) {
 | 
						|
        return EXIT_FAILURE;
 | 
						|
    }
 | 
						|
 | 
						|
    fd = get_fd_num(argv[2], true);
 | 
						|
    if (fd < 0) {
 | 
						|
        /* Now only open a file in readonly mode for test purpose. If more
 | 
						|
           precise control is needed, use python script in file operation, which
 | 
						|
           is supposed to fork and exec this program. */
 | 
						|
        fd = open(argv[2], O_RDONLY);
 | 
						|
        if (fd < 0) {
 | 
						|
            fprintf(stderr, "Failed to open file '%s'\n", argv[2]);
 | 
						|
            return EXIT_FAILURE;
 | 
						|
        }
 | 
						|
    }
 | 
						|
 | 
						|
    ret = send_fd(sock, fd);
 | 
						|
    if (ret < 0) {
 | 
						|
        close(fd);
 | 
						|
        return EXIT_FAILURE;
 | 
						|
    }
 | 
						|
 | 
						|
    close(fd);
 | 
						|
    return EXIT_SUCCESS;
 | 
						|
}
 |