Stephen Hemminger wrote: > On Mon, 18 Dec 2017 23:37:09 +0200 > Serhey Popovich <serhe.popov...@gmail.com> wrote: > >> Stephen Hemminger wrote: >>> On Mon, 18 Dec 2017 23:02:07 +0200 >>> Serhey Popovich <serhe.popov...@gmail.com> wrote: >>> >>>> Stephen Hemminger wrote: >>>>> On Mon, 18 Dec 2017 20:54:06 +0200 >>>>> Serhey Popovych <serhe.popov...@gmail.com> wrote: >>>>> >>>>>> diff --git a/ip/iplink.c b/ip/iplink.c >>>>>> index 1e685cc..4f9c169 100644 >>>>>> --- a/ip/iplink.c >>>>>> +++ b/ip/iplink.c >>>>>> @@ -586,8 +586,10 @@ int iplink_parse(int argc, char **argv, struct >>>>>> iplink_req *req, >>>>>> *name = *argv; >>>>>> } else if (strcmp(*argv, "index") == 0) { >>>>>> NEXT_ARG(); >>>>>> + if (*index) >>>>>> + duparg("index", *argv); >>>>>> *index = atoi(*argv); >>>>>> - if (*index < 0) >>>>>> + if (*index <= 0) >>>>> >>>>> Why not use strtoul instead of atoi? >>>> Do not see reason for strtoul() instead atoi(): >>>> >>>> 1) main arg: indexes in kernel represented as "int", which is >>>> signed. <= 0 values are reserved for various special purposes >>>> (see net/core/fib_rules.c on how device matching implemented). >>>> >>>> Configuring network device manually with index <= 0 is not correct >>>> (however possible). Kernel itself never chooses ifindex <= 0. >>>> >>>> Having unsigned int > 0x7fffffff actually means index <= 0. >>>> >>>> 2) this is not single place in iproute2 where it is used: not >>>> going to remove last user. >>>> >>>> 3) make changes clear and transparent for review. >>> >>> I would rather all of iproute2 correctly handles unsigned values. >>> Too much code is old K&R style C "the world is an int" and "who needs >>> to check for negative". >> >> You are right :(. I'm just trying to improve things a bit. >> >>> >>> There already is get_unsigned() in iproute2 util functions. >> This is good one based on strtoul(). But do we want to submit say >> index = (unsigned int)2147483648(0x7fffffff) to the kernel that is >> illegal from it's perspective? >> >> Or do you mean I can prepare treewide change to replace atoi() with >> get_unsigned()/get_integer() where appropriate? >> >> We already check if (*index < 0) since commit 3c682146aeff >> (iplink: forbid negative ifindex and modifying ifindex), and I just >> put index == 0 in the same range of invalid indexes. >> > > The legacy BSD ABI for interfaces uses int, so that sets the upper > bound for kernel. > > The netlink ABI limit is u32 for ifindex so technically 1..UINT32_MAX are > possible values but kernel is bound by BSD mistake. Thank you for in depth explanation!
> > I will take the original patch. > >
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