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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2016-03-25 03:53:42 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2016-03-25 03:53:42 -0300
commit03dd4cb26d967f9588437b0fc9cc0e8353322bb7 (patch)
treefa581f6dc1c0596391690d1f67eceef3af8246dc /tools/lib/bpf/libbpf.h
parentd4e493caf788ef44982e131ff9c786546904d934 (diff)
Linux-libre 4.5-gnu
Diffstat (limited to 'tools/lib/bpf/libbpf.h')
-rw-r--r--tools/lib/bpf/libbpf.h88
1 files changed, 88 insertions, 0 deletions
diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index c9a9aef28..a51594c7b 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -88,6 +88,70 @@ const char *bpf_program__title(struct bpf_program *prog, bool needs_copy);
int bpf_program__fd(struct bpf_program *prog);
+struct bpf_insn;
+
+/*
+ * Libbpf allows callers to adjust BPF programs before being loaded
+ * into kernel. One program in an object file can be transform into
+ * multiple variants to be attached to different code.
+ *
+ * bpf_program_prep_t, bpf_program__set_prep and bpf_program__nth_fd
+ * are APIs for this propose.
+ *
+ * - bpf_program_prep_t:
+ * It defines 'preprocessor', which is a caller defined function
+ * passed to libbpf through bpf_program__set_prep(), and will be
+ * called before program is loaded. The processor should adjust
+ * the program one time for each instances according to the number
+ * passed to it.
+ *
+ * - bpf_program__set_prep:
+ * Attachs a preprocessor to a BPF program. The number of instances
+ * whould be created is also passed through this function.
+ *
+ * - bpf_program__nth_fd:
+ * After the program is loaded, get resuling fds from bpf program for
+ * each instances.
+ *
+ * If bpf_program__set_prep() is not used, the program whould be loaded
+ * without adjustment during bpf_object__load(). The program has only
+ * one instance. In this case bpf_program__fd(prog) is equal to
+ * bpf_program__nth_fd(prog, 0).
+ */
+
+struct bpf_prog_prep_result {
+ /*
+ * If not NULL, load new instruction array.
+ * If set to NULL, don't load this instance.
+ */
+ struct bpf_insn *new_insn_ptr;
+ int new_insn_cnt;
+
+ /* If not NULL, result fd is set to it */
+ int *pfd;
+};
+
+/*
+ * Parameters of bpf_program_prep_t:
+ * - prog: The bpf_program being loaded.
+ * - n: Index of instance being generated.
+ * - insns: BPF instructions array.
+ * - insns_cnt:Number of instructions in insns.
+ * - res: Output parameter, result of transformation.
+ *
+ * Return value:
+ * - Zero: pre-processing success.
+ * - Non-zero: pre-processing, stop loading.
+ */
+typedef int (*bpf_program_prep_t)(struct bpf_program *prog, int n,
+ struct bpf_insn *insns, int insns_cnt,
+ struct bpf_prog_prep_result *res);
+
+int bpf_program__set_prep(struct bpf_program *prog, int nr_instance,
+ bpf_program_prep_t prep);
+
+int bpf_program__nth_fd(struct bpf_program *prog, int n);
+
/*
* We don't need __attribute__((packed)) now since it is
* unnecessary for 'bpf_map_def' because they are all aligned.
@@ -101,4 +165,28 @@ struct bpf_map_def {
unsigned int max_entries;
};
+/*
+ * There is another 'struct bpf_map' in include/linux/map.h. However,
+ * it is not a uapi header so no need to consider name clash.
+ */
+struct bpf_map;
+struct bpf_map *
+bpf_object__get_map_by_name(struct bpf_object *obj, const char *name);
+
+struct bpf_map *
+bpf_map__next(struct bpf_map *map, struct bpf_object *obj);
+#define bpf_map__for_each(pos, obj) \
+ for ((pos) = bpf_map__next(NULL, (obj)); \
+ (pos) != NULL; \
+ (pos) = bpf_map__next((pos), (obj)))
+
+int bpf_map__get_fd(struct bpf_map *map);
+int bpf_map__get_def(struct bpf_map *map, struct bpf_map_def *pdef);
+const char *bpf_map__get_name(struct bpf_map *map);
+
+typedef void (*bpf_map_clear_priv_t)(struct bpf_map *, void *);
+int bpf_map__set_private(struct bpf_map *map, void *priv,
+ bpf_map_clear_priv_t clear_priv);
+int bpf_map__get_private(struct bpf_map *map, void **ppriv);
+
#endif