f_bpf: allow for optional classid and add flags

When having optional classid, most minimal command can be sth
like:

  tc filter add dev foo parent X: bpf obj prog.o

Therefore, adapt the code so that a next argument will not be
enforced as the case currently.

Also, minor cleanup on the classid, where we should rather
have used addattr32(), and add flags for exec configuration,
for example (using short notation):

  tc filter add dev foo parent X: bpf da obj prog.o

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>

diff --git a/include/utils.h b/include/utils.h
index f77edeb0f8845fec65ecc7daffebb6cf3cb28e8e..668d159cec2f6f8ece8ab6af4cb95887204794d2 100644 (file)
--- a/include/utils.h
+++ b/include/utils.h
@@ -47,6 +47,7 @@ void incomplete_command(void) __attribute__((noreturn));
 
 #define NEXT_ARG() do { argv++; if (--argc <= 0) incomplete_command(); } while(0)
 #define NEXT_ARG_OK() (argc - 1 > 0)
+#define NEXT_ARG_FWD() do { argv++; argc--; } while(0)
 #define PREV_ARG() do { argv--; argc++; } while(0)
 
 typedef struct

diff --git a/tc/f_bpf.c b/tc/f_bpf.c
index 490dc6b4e7ba58a8e56e7d5708316e5344e2fed6..ac77af58378c89b436aa9d4b12b3a558514166b0 100644 (file)
--- a/tc/f_bpf.c
+++ b/tc/f_bpf.c
@@ -41,7 +41,7 @@ static void explain(void)
        fprintf(stderr, "\n");
        fprintf(stderr, "eBPF use case:\n");
        fprintf(stderr, " object-file FILE [ section CLS_NAME ] [ export UDS_FILE ]");
-       fprintf(stderr, " [ verbose ]\n");
+       fprintf(stderr, " [ verbose ] [ direct-action ]\n");
        fprintf(stderr, "\n");
        fprintf(stderr, "Common remaining options:\n");
        fprintf(stderr, " [ action ACTION_SPEC ]\n");
@@ -69,6 +69,7 @@ static int bpf_parse_opt(struct filter_util *qu, char *handle,
        struct tcmsg *t = NLMSG_DATA(n);
        const char *bpf_uds_name = NULL;
        const char *bpf_sec_name = NULL;
+       unsigned int bpf_flags = 0;
        char *bpf_obj = NULL;
        struct rtattr *tail;
        bool seen_run = false;
@@ -124,25 +125,28 @@ opt_bpf:
                        if (ebpf) {
                                bpf_uds_name = getenv(BPF_ENV_UDS);
                                bpf_obj = *argv;
-                               NEXT_ARG();
 
-                               if (strcmp(*argv, "section") == 0 ||
-                                   strcmp(*argv, "sec") == 0) {
+                               NEXT_ARG_FWD();
+
+                               if (argc > 0 &&
+                                   (strcmp(*argv, "section") == 0 ||
+                                    strcmp(*argv, "sec") == 0)) {
                                        NEXT_ARG();
                                        bpf_sec_name = *argv;
-                                       NEXT_ARG();
+                                       NEXT_ARG_FWD();
                                }
-                               if (!bpf_uds_name &&
+                               if (argc > 0 && !bpf_uds_name &&
                                    (strcmp(*argv, "export") == 0 ||
                                     strcmp(*argv, "exp") == 0)) {
                                        NEXT_ARG();
                                        bpf_uds_name = *argv;
-                                       NEXT_ARG();
+                                       NEXT_ARG_FWD();
                                }
-                               if (strcmp(*argv, "verbose") == 0 ||
-                                   strcmp(*argv, "verb") == 0) {
+                               if (argc > 0 &&
+                                   (strcmp(*argv, "verbose") == 0 ||
+                                    strcmp(*argv, "verb") == 0)) {
                                        bpf_verbose = true;
-                                       NEXT_ARG();
+                                       NEXT_ARG_FWD();
                                }
 
                                PREV_ARG();
@@ -182,7 +186,10 @@ opt_bpf:
                                fprintf(stderr, "Illegal \"classid\"\n");
                                return -1;
                        }
-                       addattr_l(n, MAX_MSG, TCA_BPF_CLASSID, &handle, 4);
+                       addattr32(n, MAX_MSG, TCA_BPF_CLASSID, handle);
+               } else if (matches(*argv, "direct-action") == 0 ||
+                          matches(*argv, "da") == 0) {
+                       bpf_flags |= TCA_BPF_FLAG_ACT_DIRECT;
                } else if (matches(*argv, "action") == 0) {
                        NEXT_ARG();
                        if (parse_action(&argc, &argv, TCA_BPF_ACT, n)) {
@@ -208,10 +215,13 @@ opt_bpf:
                        explain();
                        return -1;
                }
-               argc--;
-               argv++;
+
+               NEXT_ARG_FWD();
        }
 
+       if (bpf_obj && bpf_flags)
+               addattr32(n, MAX_MSG, TCA_BPF_FLAGS, bpf_flags);
+
        tail->rta_len = (((void *)n) + n->nlmsg_len) - (void *)tail;
 
        if (bpf_uds_name)
@@ -244,6 +254,13 @@ static int bpf_print_opt(struct filter_util *qu, FILE *f,
        else if (tb[TCA_BPF_FD])
                fprintf(f, "pfd %u ", rta_getattr_u32(tb[TCA_BPF_FD]));
 
+       if (tb[TCA_BPF_FLAGS]) {
+               unsigned int flags = rta_getattr_u32(tb[TCA_BPF_FLAGS]);
+
+               if (flags & TCA_BPF_FLAG_ACT_DIRECT)
+                       fprintf(f, "direct-action ");
+       }
+
        if (tb[TCA_BPF_OPS] && tb[TCA_BPF_OPS_LEN]) {
                bpf_print_ops(f, tb[TCA_BPF_OPS],
                              rta_getattr_u16(tb[TCA_BPF_OPS_LEN]));