Quoting Guillaume ZITTA (l...@zitta.fr):
> >>If not, my proposal:
> >> I set an incomplete (prefix) lxc.network.hwaddr in default conf.
> >> lxc-create complete it randomly and write it to the container's
> >>config.
> >>
> >>Does it make sense?
> >
> >I think so. Just 'xx' in place of real numbers?
> >
> >>I do not/can't code in C, but perhaps I should try ...
> >>
> >>Guillaume ZITTA
>
> Please be kind, it's the second time I do "C" of my life :)
>
> Note about randinit():
> that kind of util can be used in network.c/lxc_mkifname() and
> lxccontainer.c/new_hwaddr()
>
> It works for me, I did 1000 destroy/create (with fake template) in
> 43 sec without mac duplicate.
>
> If I'm not completely doing wrong, I'll provide patch for manpage
> and HAVE_RAND_R ifdef.
>
> please comment.
Looks good, except for one comment below, and if you do submit
this please do add a Signed-off-by line.
>
> diff --git a/src/lxc/confile.c b/src/lxc/confile.c
> index c5ec4f3..5721e05 100644
> --- a/src/lxc/confile.c
> +++ b/src/lxc/confile.c
> @@ -509,6 +509,24 @@ static int macvlan_mode(int *valuep, const char
> *value)
> return -1;
> }
>
> +char *rand_complete_hwaddr(const char *hwaddr)
> +{
> + const char hex[] = "0123456789abcdef";
> + char *retval=NULL;
> + retval = strdup(hwaddr);
> + char *curs = retval;
> +
> + randinit();
> +
> + while (*curs != '\0')
> + {
> + if ( *curs == 'x' || *curs == 'X' )
> + *curs = hex[rand() & 0x0F];
> + curs++;
> + }
> + return retval;
> +}
> +
> static int config_network_flags(const char *key, const char *value,
> struct lxc_conf *lxc_conf)
> {
> @@ -576,11 +594,13 @@ static int config_network_hwaddr(const char
> *key, const char *value,
> {
> struct lxc_netdev *netdev;
>
> - netdev = network_netdev(key, value, &lxc_conf->network);
> + const char *newval = rand_complete_hwaddr(value);
newval got strdup()d above, but is never freed. config_string_item()
will actually strdup that again for the value added to the
configuration. So you need to free newval on exiting this function.
> +
> + netdev = network_netdev(key, newval, &lxc_conf->network);
> if (!netdev)
> return -1;
>
> - return config_string_item(&netdev->hwaddr, value);
> + return config_string_item(&netdev->hwaddr, newval);
> }
>
> static int config_network_vlan_id(const char *key, const char *value,
> diff --git a/src/lxc/utils.c b/src/lxc/utils.c
> index 785f3e6..204179e 100644
> --- a/src/lxc/utils.c
> +++ b/src/lxc/utils.c
> @@ -1126,3 +1126,25 @@ void **lxc_append_null_to_array(void **array,
> size_t count)
> }
> return array;
> }
> +
> +void randinit(void)
> +{
> + /*
> + srand pre-seed function based on /dev/urandom
> + */
> + FILE *f;
> + process_lock();
> + f = fopen("/dev/urandom", "r");
> + process_unlock();
> + if (f) {
> + unsigned int seed;
> + int ret = fread(&seed, sizeof(seed), 1, f);
> + if (ret != 1)
> + seed = time(NULL);
> + process_lock();
> + fclose(f);
> + process_unlock();
> + srand(seed);
> + } else
> + srand(time(NULL));
> +}
> \ No newline at end of file
> diff --git a/src/lxc/utils.h b/src/lxc/utils.h
> index 945f1de..f20339b 100644
> --- a/src/lxc/utils.h
> +++ b/src/lxc/utils.h
> @@ -270,4 +270,7 @@ extern void **lxc_dup_array(void **array,
> lxc_dup_fn element_dup_fn, lxc_free_fn
> extern void **lxc_append_null_to_array(void **array, size_t count);
>
> extern void dump_stacktrace(void);
> +
> +//initialize rand with urandom
> +extern void randinit(void);
> #endif
>
> _______________________________________________
> lxc-devel mailing list
> lxc-devel@lists.linuxcontainers.org
> http://lists.linuxcontainers.org/listinfo/lxc-devel
_______________________________________________
lxc-devel mailing list
lxc-devel@lists.linuxcontainers.org
http://lists.linuxcontainers.org/listinfo/lxc-devel
