f_bpf: communicate ifindex for eBPF offload

Split parsing and loading of the eBPF program and if skip_sw is set
load the program for ifindex, to which the qdisc is attached.

Note that the ifindex will be ignored for programs which are already
loaded (e.g. when using pinned programs), but in that case we just
trust the user knows what he's doing.  Hopefully we will get extack
soon in the driver to help debugging this case.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>

diff --git a/tc/f_bpf.c b/tc/f_bpf.c
index f598784e8b0852f46caca340f4bd8cc476da9dfb..5906f8bb969def1d924395f5eac06313e2a45fc5 100644 (file)
--- a/tc/f_bpf.c
+++ b/tc/f_bpf.c
@@ -82,6 +82,7 @@ static int bpf_parse_opt(struct filter_util *qu, char *handle,
        unsigned int bpf_flags = 0;
        struct bpf_cfg_in cfg = {};
        bool seen_run = false;
+       bool skip_sw = false;
        struct rtattr *tail;
        int ret = 0;
 
@@ -110,8 +111,11 @@ opt_bpf:
                        cfg.argc = argc;
                        cfg.argv = argv;
 
-                       if (bpf_parse_and_load_common(&cfg, &bpf_cb_ops, n))
+                       if (bpf_parse_common(&cfg, &bpf_cb_ops) < 0) {
+                               fprintf(stderr,
+                                       "Unable to parse bpf command line\n");
                                return -1;
+                       }
 
                        argc = cfg.argc;
                        argv = cfg.argv;
@@ -135,6 +139,7 @@ opt_bpf:
                        bpf_gen_flags |= TCA_CLS_FLAGS_SKIP_HW;
                } else if (matches(*argv, "skip_sw") == 0) {
                        bpf_gen_flags |= TCA_CLS_FLAGS_SKIP_SW;
+                       skip_sw = true;
                } else if (matches(*argv, "action") == 0) {
                        NEXT_ARG();
                        if (parse_action(&argc, &argv, TCA_BPF_ACT, n)) {
@@ -164,6 +169,13 @@ opt_bpf:
                NEXT_ARG_FWD();
        }
 
+       if (skip_sw)
+               cfg.ifindex = t->tcm_ifindex;
+       if (bpf_load_common(&cfg, &bpf_cb_ops, n) < 0) {
+               fprintf(stderr, "Unable to load program\n");
+               return -1;
+       }
+
        if (bpf_gen_flags)
                addattr32(n, MAX_MSG, TCA_BPF_FLAGS_GEN, bpf_gen_flags);
        if (bpf_flags)