Re: [dpdk-dev] [PATCH 3/6] net/tap: check interface name in kvargs

["Luse, Paul E" <paul.e.luse@intel.com>]

Thanks Jim!!

-from my iPhone 

> On Jan 11, 2019, at 11:37 AM, Wiles, Keith <keith.wiles@intel.com> wrote:
> 
> 
> 
>> On Jan 11, 2019, at 12:06 PM, Stephen Hemminger <stephen@networkplumber.org> wrote:
>> 
>> If interface name is passed to remote or iface then check
>> the length and for invalid characters. This avoids problems where
>> name gets truncated or rejected by kernel.
>> 
>> Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
>> ---
>> drivers/net/tap/rte_eth_tap.c | 37 +++++++++++++++++++++++++++++++----
>> 1 file changed, 33 insertions(+), 4 deletions(-)
>> 
>> diff --git a/drivers/net/tap/rte_eth_tap.c b/drivers/net/tap/rte_eth_tap.c
>> index d7f77d664502..6a388eed0dd4 100644
>> --- a/drivers/net/tap/rte_eth_tap.c
>> +++ b/drivers/net/tap/rte_eth_tap.c
>> @@ -37,6 +37,7 @@
>> #include <linux/if_tun.h>
>> #include <linux/if_ether.h>
>> #include <fcntl.h>
>> +#include <ctype.h>
>> 
>> #include <tap_rss.h>
>> #include <rte_eth_tap.h>
>> @@ -1884,6 +1885,23 @@ eth_dev_tap_create(struct rte_vdev_device *vdev, char *tap_name,
>>    return -EINVAL;
>> }
>> 
>> +/* make sure name is a possible Linux network device name */
>> +static bool is_valid_iface(const char *name)
> 
> I am sorry, but the function name must be on the next line as per the style. I know you do not like it, but that is what the style states.
>> +{
>> +    if (*name == '\0')
>> +        return false;
>> +
>> +    if (strnlen(name, IFNAMSIZ) == IFNAMSIZ)
>> +        return false;
>> +
>> +    while (*name) {
>> +        if (*name == '/' || *name == ':' || isspace(*name))
>> +            return false;
>> +        name++;
>> +    }
>> +    return true;
>> +}
>> +
>> static int
>> set_interface_name(const char *key __rte_unused,
>>           const char *value,
>> @@ -1891,12 +1909,17 @@ set_interface_name(const char *key __rte_unused,
>> {
>>    char *name = (char *)extra_args;
>> 
>> -    if (value)
>> +    if (value) {
>> +        if (!is_valid_iface(value)) {
>> +            TAP_LOG(ERR, "TAP invalid remote interface name (%s)",
>> +                value);
>> +            return -1;
>> +        }
>>        strlcpy(name, value, RTE_ETH_NAME_MAX_LEN);
>> -    else
>> +    } else {
>>        snprintf(name, RTE_ETH_NAME_MAX_LEN, "%s%d",
>>             DEFAULT_TAP_NAME, tun_unit - 1);
>> -
>> +    }
> 
> This is also a one line else and the style states to remove the {}.
>>    return 0;
>> }
>> 
>> @@ -1907,8 +1930,14 @@ set_remote_iface(const char *key __rte_unused,
>> {
>>    char *name = (char *)extra_args;
>> 
>> -    if (value)
>> +    if (value) {
>> +        if (!is_valid_iface(value)) {
>> +            TAP_LOG(ERR, "TAP invalid remote interface name (%s)",
>> +                value);
>> +            return -1;
>> +        }
>>        strlcpy(name, value, RTE_ETH_NAME_MAX_LEN);
>> +    }
>> 
>>    return 0;
>> }
>> -- 
>> 2.20.1
>> 
> 
> I hate having to be the style police, but until we use something to validate the DPDK coding style (as I posted the uncrustify config last month) we have to keep the style the same or change the DPDK coding standard.
> 
> Regards,
> Keith
>