On Mon, 29 May 2017 15:42:18 +0200
Gaetan Rivet <gaetan.ri...@6wind.com> wrote:
>
> +- **exec(<shell command>)** parameter
> +
> + This parameter allows the user to provide a command to the fail-safe PMD to
> + execute and define a sub-device.
> + It is done within a regular shell context.
> + The first line of its output is read by the fail-safe PMD and otherwise
> + interpreted as if passed by the regular **dev** parameter.
> + Any other line is discarded.
> + If the command fail or output an incorrect string, the sub-device is not
> + initialized.
> + All commas within the ``shell command`` are replaced by spaces before
> + executing the command. This helps using scripts to specify devices.
> +
Exec from a DPDK application seems like possible security hole since most DPDK
applications
have to run as root.
> static int
> +fs_execute_cmd(struct sub_device *sdev, char *cmdline)
> +{
> + FILE *fp;
> + /* store possible newline as well */
> + char output[DEVARGS_MAXLEN + 1];
> + size_t len;
> + int old_err;
> + int ret;
> +
> + assert(cmdline != NULL || sdev->cmdline != NULL);
> + if (sdev->cmdline == NULL) {
> + char *new_str;
> + size_t i;
> +
> + len = strlen(cmdline) + 1;
> + new_str = rte_realloc(sdev->cmdline, len,
> + RTE_CACHE_LINE_SIZE);
> + if (new_str == NULL) {
> + ERROR("Command line allocation failed");
> + return -ENOMEM;
> + }
Using rte_malloc for cmdline is way over optimizing. rte_malloc comes from huge
page area
which is limited. The only reason to use it is if the memory needs to be shared
by primary/slave.
Also rte_malloc has much less protection (memleak checkers, guards etc)
compared to regular malloc.
