On 22-Jul-19 2:06 AM, Ogawa Yasufumi wrote:
2019年7月12日(金) 11:22 Yasufumi Ogawa <yasufu...@gmail.com
<mailto:yasufu...@gmail.com>>:
On 2019/07/11 22:14, Burakov, Anatoly wrote:
> On 11-Jul-19 12:57 PM, Yasufumi Ogawa wrote:
>> On 2019/07/11 19:53, Burakov, Anatoly wrote:
>>> On 11-Jul-19 11:31 AM, yasufu...@gmail.com
<mailto:yasufu...@gmail.com> wrote:
>>>> From: Yasufumi Ogawa <ogawa.yasuf...@lab.ntt.co.jp
<mailto:ogawa.yasuf...@lab.ntt.co.jp>>
>>>>
>>> <...>
>>>
>>>> + if (getpid() == 1) {
>>>> + FILE *hn_fp;
>>>> + hn_fp = fopen("/etc/hostname", "r");
>>>> + if (hn_fp == NULL) {
>>>> + RTE_LOG(ERR, EAL,
>>>> + "Cannot open '/etc/hostname' for secondary\n");
>>>> + return -1;
>>>> + }
>>>> +
>>>> + /* with docker, /etc/hostname just has one entry of
>>>> hostname */
>>>> + if (fscanf(hn_fp, "%s", proc_id) == EOF) {
>>>
>>> Apologies for not pointing this out earlier, but do i understand
>>> correctly that there's no bounds checking here, and fscanf() will
>>> write however many bytes it wants?
>> I understand "%s" is not appropriate. hostname is 12 bytes char
and I
>> thought proc_id[16] is enough, but it is unsafe. In addition,
hostname
>> can be defined by user with docker's option, so it should be enough
>> for user defined name.
>>
>> How do you think expecting max 32 chars of hostname and set
boundary
>> "%32s" as following?
>>
>> proc_id[33]; /* define proc id from hostname less than 33
bytes. */
>> ...
>> if (fscanf(hn_fp, "%32s", proc_id) == EOF) {
>>
>
> As long as it takes NULL-termination into account as well, it
should be
> OK. I can't recall off the top of my head if %32s includes NULL
> terminator (probably not?).
Do you agree if initialize with NULL chars to ensure proc_id is
NULL-terminated? As tested on my environment, "%Ns" sets next of Nth
char as NULL, but it seems more reliable.
proc_id[33] = { 0 };
Hi Anatoly,
I would like to send v4 patch if it is agreeable.
Yes, please do.
As a side note, you don't need to ask anyone's permission to send a patch :)
Yasufumi
--
Thanks,
Anatoly
