On Fri, Aug 2, 2019 at 3:26 PM Y Song <[email protected]> wrote:
>
> On Thu, Aug 1, 2019 at 2:04 AM Daniel T. Lee <[email protected]> wrote:
> >
> > By this commit, using `bpftool net detach`, the attached XDP prog can
> > be detached. Detaching the BPF prog will be done through libbpf
> > 'bpf_set_link_xdp_fd' with the progfd set to -1.
> >
> > Signed-off-by: Daniel T. Lee <[email protected]>
> > ---
> > Changes in v2:
> > - command 'unload' changed to 'detach' for the consistency
> >
> > tools/bpf/bpftool/net.c | 55 ++++++++++++++++++++++++++++++++++++++++-
> > 1 file changed, 54 insertions(+), 1 deletion(-)
> >
> > diff --git a/tools/bpf/bpftool/net.c b/tools/bpf/bpftool/net.c
> > index f3b57660b303..2ae9a613b05c 100644
> > --- a/tools/bpf/bpftool/net.c
> > +++ b/tools/bpf/bpftool/net.c
> > @@ -281,6 +281,31 @@ static int parse_attach_args(int argc, char **argv,
> > int *progfd,
> > return 0;
> > }
> >
> > +static int parse_detach_args(int argc, char **argv,
> > + enum net_attach_type *attach_type, int
> > *ifindex)
> > +{
> > + if (!REQ_ARGS(2))
> > + return -EINVAL;
> > +
> > + *attach_type = parse_attach_type(*argv);
> > + if (*attach_type == __MAX_NET_ATTACH_TYPE) {
> > + p_err("invalid net attach/detach type");
> > + return -EINVAL;
> > + }
> > +
> > + NEXT_ARG();
> > + if (!REQ_ARGS(1))
> > + return -EINVAL;
> > +
> > + *ifindex = if_nametoindex(*argv);
> > + if (!*ifindex) {
> > + p_err("Invalid ifname");
> > + return -EINVAL;
> > + }
> > +
> > + return 0;
> > +}
> > +
> > static int do_attach_detach_xdp(int *progfd, enum net_attach_type
> > *attach_type,
> > int *ifindex)
> > {
> > @@ -323,6 +348,31 @@ static int do_attach(int argc, char **argv)
> > return 0;
> > }
> >
> > +static int do_detach(int argc, char **argv)
> > +{
> > + enum net_attach_type attach_type;
> > + int err, progfd, ifindex;
> > +
> > + err = parse_detach_args(argc, argv, &attach_type, &ifindex);
> > + if (err)
> > + return err;
> > +
> > + /* to detach xdp prog */
> > + progfd = -1;
> > + if (is_prefix("xdp", attach_type_strings[attach_type]))
> > + err = do_attach_detach_xdp(&progfd, &attach_type, &ifindex);
>
> Similar to previous patch, parameters no need to be pointer.
>
I will change the parameter as pass by value.
> > +
> > + if (err < 0) {
> > + p_err("link set %s failed",
> > attach_type_strings[attach_type]);
> > + return -1;
>
> Maybe "return err"?
>
Hadn't thought of that.
I will change to it!
> > + }
> > +
> > + if (json_output)
> > + jsonw_null(json_wtr);
> > +
> > + return 0;
> > +}
> > +
> > static int do_show(int argc, char **argv)
> > {
> > struct bpf_attach_info attach_info = {};
> > @@ -406,6 +456,7 @@ static int do_help(int argc, char **argv)
> > fprintf(stderr,
> > "Usage: %s %s { show | list } [dev <devname>]\n"
> > " %s %s attach PROG LOAD_TYPE <devname>\n"
> > + " %s %s detach LOAD_TYPE <devname>\n"
> > " %s %s help\n"
> > "\n"
> > " " HELP_SPEC_PROGRAM "\n"
> > @@ -415,7 +466,8 @@ static int do_help(int argc, char **argv)
> > " to dump program attachments. For program types\n"
> > " sk_{filter,skb,msg,reuseport} and lwt/seg6, please\n"
> > " consult iproute2.\n",
> > - bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2]);
> > + bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2],
> > + bin_name, argv[-2]);
> >
> > return 0;
> > }
> > @@ -424,6 +476,7 @@ static const struct cmd cmds[] = {
> > { "show", do_show },
> > { "list", do_show },
> > { "attach", do_attach },
> > + { "detach", do_detach },
> > { "help", do_help },
> > { 0 }
> > };
> > --
> > 2.20.1
> >
Thanks for the review!
