LXR qemu/tests/qemu-iotests/socket_scm

   1/*
   2 * SCM_RIGHTS with unix socket help program for test
   3 *
   4 * Copyright IBM, Inc. 2013
   5 *
   6 * Authors:
   7 *  Wenchao Xia    <xiawenc@linux.vnet.ibm.com>
   8 *
   9 * This work is licensed under the terms of the GNU LGPL, version 2 or later.
  10 * See the COPYING.LIB file in the top-level directory.
  11 */
  12
  13#include "qemu/osdep.h"
  14#include <sys/socket.h>
  15#include <sys/un.h>
  16
  17/* #define SOCKET_SCM_DEBUG */
  18
  19/*
  20 * @fd and @fd_to_send will not be checked for validation in this function,
  21 * a blank will be sent as iov data to notify qemu.
  22 */
  23static int send_fd(int fd, int fd_to_send)
  24{
  25    struct msghdr msg;
  26    struct iovec iov[1];
  27    int ret;
  28    char control[CMSG_SPACE(sizeof(int))];
  29    struct cmsghdr *cmsg;
  30
  31    memset(&msg, 0, sizeof(msg));
  32    memset(control, 0, sizeof(control));
  33
  34    /* Send a blank to notify qemu */
  35    iov[0].iov_base = (void *)" ";
  36    iov[0].iov_len = 1;
  37
  38    msg.msg_iov = iov;
  39    msg.msg_iovlen = 1;
  40
  41    msg.msg_control = control;
  42    msg.msg_controllen = sizeof(control);
  43
  44    cmsg = CMSG_FIRSTHDR(&msg);
  45
  46    cmsg->cmsg_len = CMSG_LEN(sizeof(int));
  47    cmsg->cmsg_level = SOL_SOCKET;
  48    cmsg->cmsg_type = SCM_RIGHTS;
  49    memcpy(CMSG_DATA(cmsg), &fd_to_send, sizeof(int));
  50
  51    do {
  52        ret = sendmsg(fd, &msg, 0);
  53    } while (ret < 0 && errno == EINTR);
  54
  55    if (ret < 0) {
  56        fprintf(stderr, "Failed to send msg, reason: %s\n", strerror(errno));
  57    }
  58
  59    return ret;
  60}
  61
  62/* Convert string to fd number. */
  63static int get_fd_num(const char *fd_str)
  64{
  65    int sock;
  66    char *err;
  67
  68    errno = 0;
  69    sock = strtol(fd_str, &err, 10);
  70    if (errno) {
  71        fprintf(stderr, "Failed in strtol for socket fd, reason: %s\n",
  72                strerror(errno));
  73        return -1;
  74    }
  75    if (!*fd_str || *err || sock < 0) {
  76        fprintf(stderr, "bad numerical value for socket fd '%s'\n", fd_str);
  77        return -1;
  78    }
  79
  80    return sock;
  81}
  82
  83/*
  84 * To make things simple, the caller needs to specify:
  85 * 1. socket fd.
  86 * 2. path of the file to be sent.
  87 */
  88int main(int argc, char **argv, char **envp)
  89{
  90    int sock, fd, ret;
  91
  92#ifdef SOCKET_SCM_DEBUG
  93    int i;
  94    for (i = 0; i < argc; i++) {
  95        fprintf(stderr, "Parameter %d: %s\n", i, argv[i]);
  96    }
  97#endif
  98
  99    if (argc != 3) {
 100        fprintf(stderr,
 101                "Usage: %s < socket-fd > < file-path >\n",
 102                argv[0]);
 103        return EXIT_FAILURE;
 104    }
 105
 106
 107    sock = get_fd_num(argv[1]);
 108    if (sock < 0) {
 109        return EXIT_FAILURE;
 110    }
 111
 112    /* Now only open a file in readonly mode for test purpose. If more precise
 113       control is needed, use python script in file operation, which is
 114       supposed to fork and exec this program. */
 115    fd = open(argv[2], O_RDONLY);
 116    if (fd < 0) {
 117        fprintf(stderr, "Failed to open file '%s'\n", argv[2]);
 118        return EXIT_FAILURE;
 119    }
 120
 121    ret = send_fd(sock, fd);
 122    if (ret < 0) {
 123        close(fd);
 124        return EXIT_FAILURE;
 125    }
 126
 127    close(fd);
 128    return EXIT_SUCCESS;
 129}
 130