On 08/26/2013 08:52 PM, Wenchao Xia wrote: > This program can do a sendmsg call to transfer fd with unix > socket, which is not supported in python2. > > The built binary will not be deleted in clean, but it is a > existing issue in ./tests, which should be solved in another > patch. > > Signed-off-by: Wenchao Xia <xiaw...@linux.vnet.ibm.com> > ---
> +++ b/tests/qemu-iotests/socket_scm_helper.c
> @@ -0,0 +1,119 @@
> +/*
> + * SCM_RIGHT with unix socket help program for test
s/SCM_RIGHT/&S/
> +
> +static int send_fd(int fd, int fd_to_send, const char *data, size_t len)
> +{
> + struct msghdr msg;
> + struct iovec iov[1];
> + int ret;
> + char control[CMSG_SPACE(sizeof(int))];
> + struct cmsghdr *cmsg;
> +
> + if (fd < 0) {
> + fprintf(stderr, "Socket fd is invalid.\n");
> + return -1;
> + }
> + if (fd_to_send < 0) {
> + fprintf(stderr, "Fd to send is invalid.\n");
> + return -1;
> + }
> + if (data == NULL || len <= 0) {
len cannot be < 0, since it is size_t (or did you mean for it to be
ssize_t?)
> + if (ret < 0) {
> + fprintf(stderr, "Failed to send msg, reason: %s.\n",
> strerror(errno));
Messages typically shouldn't end with '.'; especially when ending the
message with strerror.
> + }
> +
> + return ret;
> +}
> +
> +/*
> + * To make things simple, the caller need to specify:
s/need/needs/
> + * 1. socket fd.
> + * 2. fd to send.
> + * 3. msg to send.
> + */
> +int main(int argc, char **argv, char **envp)
> +{
> + int sock, fd, ret, buflen;
> + const char *buf;
> +#ifdef SOCKET_SCM_DEBUG
> + int i;
> + for (i = 0; i < argc; i++) {
> + fprintf(stderr, "Parameter %d: %s.\n", i, argv[i]);
Another useless ending '.' (and elsewhere throughout the patch)
> + }
> +#endif
> +
> + if (argc < 4) {
> + fprintf(stderr,
> + "Invalid parameter, use it as:\n"
> + "%s SOCKET_FD FD_TO_SEND MSG.\n",
> + argv[0]);
This rejects too few, but not too many, arguments. Should the condition
be: if (argc != 4)
> + return 1;
I prefer EXIT_FAILURE over the magic number 1 (multiple instances).
> + }
> +
> + errno = 0;
> + sock = strtol(argv[1], NULL, 10);
Failure to pass in a second argument means you cannot distinguish ""
from "0" from "0a" - all three input strings for argv[1] result in
sock==0 without you knowing any better. If you're going to use
strtol(), use it correctly; if you don't care about garbage, then atoi()
is just as (in)correct and with less typing.
> + if (errno) {
> + fprintf(stderr, "Failed in strtol for socket fd, reason: %s.\n",
> + strerror(errno));
> + return 1;
> + }
> + fd = strtol(argv[2], NULL, 10);
> + if (errno) {
> + fprintf(stderr, "Failed in strtol for fd to send, reason: %s.\n",
> + strerror(errno));
> + return 1;
> + }
> +
> + buf = argv[3];
> + buflen = strlen(buf);
> +
> + ret = send_fd(sock, fd, buf, buflen);
> + if (ret < 0) {
> + return 1;
> + }
> + return 0;
I prefer EXIT_SUCCESS over the magic number 0.
> +}
>
--
Eric Blake eblake redhat com +1-919-301-3266
Libvirt virtualization library http://libvirt.org
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