Hi Pablo, On Wed, Feb 19, 2020 at 07:04:10PM +0100, Pablo Neira Ayuso wrote: > On Sat, Feb 01, 2020 at 05:21:27PM +1100, Duncan Roe wrote: > > Functions pktb_alloc_data, pktb_make and pktb_make_data are defined. > > The pktb_make pair are syggested as replacements for the pktb_alloc (now) pair > > because they are always faster. > > > > - Add prototypes to include/libnetfilter_queue/pktbuff.h > > - Add pktb_alloc_data much as per Pablo's email of Wed, 8 Jan 2020 > > speedup: point to packet data in netlink receive buffer rather than copy to > > area immediately following pktb struct > > - Add pktb_make much like pktb_usebuf proposed on 10 Dec 2019 > > 2 sppedups: 1. Use an existing buffer rather than calloc and (later) free one. > > 2. Only zero struct and extra parts of pktb - the rest is > > overwritten by copy (calloc has to zero the lot). > > - Add pktb_make_data > > 3 speedups: All of the above > > - Document the new functions > > - Move pktb_alloc and pktb_alloc_data into the "other functions" group since > > they are slower than the "make" equivalent functions > > > > Signed-off-by: Duncan Roe <duncan_roe@xxxxxxxxxxxxxxx> > > --- > > include/libnetfilter_queue/pktbuff.h | 3 + > > src/extra/pktbuff.c | 296 ++++++++++++++++++++++++++++++----- > > 2 files changed, 261 insertions(+), 38 deletions(-) > > > > diff --git a/include/libnetfilter_queue/pktbuff.h b/include/libnetfilter_queue/pktbuff.h > > index 42bc153..fc6bf01 100644 > > --- a/include/libnetfilter_queue/pktbuff.h > > +++ b/include/libnetfilter_queue/pktbuff.h > > @@ -4,6 +4,9 @@ > > struct pkt_buff; > > > > struct pkt_buff *pktb_alloc(int family, void *data, size_t len, size_t extra); > > +struct pkt_buff *pktb_alloc_data(int family, void *data, size_t len); > > +struct pkt_buff *pktb_make(int family, void *data, size_t len, size_t extra, void *buf, size_t bufsize); > > +struct pkt_buff *pktb_make_data(int family, void *data, size_t len, void *buf, size_t bufsize); > > Hm, when I delivered the patch to you, I forgot that you main point > was that you wanted to skip the memory allocation. > > I wonder if all these new functions can be consolidated into one > single function, something like: > > struct pkt_buff *pktb_alloc2(int family, void *head, size_t head_size, void *data, size_t len, size_t extra); > > The idea is that: > > * head is the memory area that is large enough for the struct pkt_buff > (metadata). You can add a new pktb_head_size() function that returns > the size of opaque struct pkt_buff structure (whose layout is not > exposed to the user). I think you can this void *buf in your pktb_make > function. > > * data is the memory area to store the network packet itself. Wait, you need data & len to describe where the data is *now*. You need an extra buf, buflen pair for where to put it. > > Then, you can allocate head and data in the stack and skip > malloc/calloc. > > Would this work for you? I would prefer if there is just one single > advanced function to do this. > > Thanks for your patience. I think I can do as you requested. Just one thing: do you really think pktb_alloc2 is a good name when users *must not* call pktb_free? pktb_put would have been good but it's already taken. Perhaps pktb_alloc2 could set a flag for pktb_free to become a no-op and maybe issue a warning the first time it is called - would that be worth doing? In pktb_alloc2, if extra == 0 then buf can be NULL and buflen 0, since the data will be left in place. That way, we get a single entry point doing as much optimising as possible. Cheers ... Duncan.
