Re: [PATCH 02/12] net: add function to pretty print IPv4

[Thomas Monjalon <thomas@monjalon.net>]

15/12/2021 14:06, Ananyev, Konstantin:
> 
> > > From: Stephen Hemminger [mailto:stephen@networkplumber.org]
> > > Sent: Wednesday, 15 December 2021 04.21
> > >
> > > On Wed, 15 Dec 2021 01:06:14 +0000
> > > "Ananyev, Konstantin" <konstantin.ananyev@intel.com> wrote:
> > > > > > --- a/lib/net/rte_ip.h
> > > > > > +++ b/lib/net/rte_ip.h
> > > > > > @@ -444,6 +444,26 @@ __rte_experimental
> > > > > >  int32_t
> > > > > >  rte_ip_parse_addr(const char *src_ip, uint32_t *output_addr);
> > > > > >
> > > > > > +
> > > > > > +/**
> > > > > > + * Print IP address from 32 bit int into char * buffer.
> > > > > > + *
> > > > > > + * @param ip_addr
> > > > > > + *   ip address to be printed.
> > > > > > + * @param buffer
> > > > > > + *   The buffer the string will be saved into.
> > > > > > + * @param buffer_size
> > > > > > + *   size of buffer to be used.
> > > > > > + *
> > > > > > + * @retval 0
> > > > > > + *   Success.
> > > > > > + * @retval -1
> > > > > > + *   Failure due to invalid input arguments.
> > > > > > + */
> > > > > > +__rte_experimental
> > > > > > +int32_t
> > > > > > +rte_ip_print_addr(uint32_t ip_addr, char *buffer, uint32_t
> > > > > > buffer_size);
> > > > > > +
> > > > >
> > > > > In continuation of my email reply about the IPv4 parse function...
> > > > >
> > > > > I have a few suggestions to the IPv4 print function too:
> > > > >
> > > > > The return value should be the number of characters written to the
> > > output string, and still -1 on error. With this modification, you could
> > > > > use the return type ssize_t instead of int32_t.
> > > > >
> > > > > Furthermore, I would prefer having the parameters in the same order
> > > as snprintf(): char *str, size_t size, const uint32_t ip_addr. Please
> > > > > also notice the suggested changed type for the size, and the const
> > > added to the ip_addr.
> > > > >
> > > > Honestly, I don't understand why we need to introduce such functions
> > > > inside DPDK at all.
> > > > What's wrong with existing standard ones: inet_ntop() and
> > > inet_pton()?
> > >
> > > Agreed, I see no added value in reinventing here
> > 
> > I think that DPDK functions for converting all sorts of types to/from strings would be useful; not only IP addresses, but also MAC addresses,
> > TCP/UDP port numbers and VLAN IDs.
> 
> For MACs we already have:
> rte_ether_format_addr()/rte_ether_unformat_addr()
> 
> > 
> > If you don't like IP address string conversion functions in the net library, DPDK could have a string conversions library. That library could
> > expose a multitude of APIs for the same purpose, so the application can use the API that best fits each application use.
> 
> I don’t mind to add new functions into net lib, if they are useful ones.
> But for that particular case, I just don't see what is the reason to
> develop and maintain our own functions while existing analogues:
> - are well known, widely adopted and field proven
> - do provide the same or even more comprehensive functionality

+1
Waiting for an answer from the authors. One month silence so far.