libbpf: add ifindex to enable offload support

BPF programs currently can only be offloaded using iproute2. This
patch will allow programs to be offloaded using libbpf calls.

Signed-off-by: David Beckett <david.beckett@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

4 files changed, 20 insertions, 3 deletions

diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c
index a3a8fb2ac697..6a8a00097fd8 100644
--- a/tools/lib/bpf/bpf.c
+++ b/tools/lib/bpf/bpf.c
@@ -91,6 +91,7 @@ int bpf_create_map_xattr(const struct bpf_create_map_attr *create_attr)
         attr.btf_fd = create_attr->btf_fd;
         attr.btf_key_id = create_attr->btf_key_id;
         attr.btf_value_id = create_attr->btf_value_id;
+        attr.map_ifindex = create_attr->map_ifindex;
 
         return sys_bpf(BPF_MAP_CREATE, &attr, sizeof(attr));
 }
@@ -201,6 +202,7 @@ int bpf_load_program_xattr(const struct bpf_load_program_attr *load_attr,
         attr.log_size = 0;
         attr.log_level = 0;
         attr.kern_version = load_attr->kern_version;
+        attr.prog_ifindex = load_attr->prog_ifindex;
         memcpy(attr.prog_name, load_attr->name,
                min(name_len, BPF_OBJ_NAME_LEN - 1));
 
diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h
index fb3a146d92ff..15bff7728cf1 100644
--- a/tools/lib/bpf/bpf.h
+++ b/tools/lib/bpf/bpf.h
@@ -38,6 +38,7 @@ struct bpf_create_map_attr {
         __u32 btf_fd;
         __u32 btf_key_id;
         __u32 btf_value_id;
+        __u32 map_ifindex;
 };
 
 int bpf_create_map_xattr(const struct bpf_create_map_attr *create_attr);
@@ -64,6 +65,7 @@ struct bpf_load_program_attr {
         size_t insns_cnt;
         const char *license;
         __u32 kern_version;
+        __u32 prog_ifindex;
 };
 
 /* Recommend log buffer size */
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index df54c4c9e48a..3dbe217bf23e 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -178,6 +178,7 @@ struct bpf_program {
         /* Index in elf obj file, for relocation use. */
         int idx;
         char *name;
+        int prog_ifindex;
         char *section_name;
         struct bpf_insn *insns;
         size_t insns_cnt, main_prog_cnt;
@@ -213,6 +214,7 @@ struct bpf_map {
         int fd;
         char *name;
         size_t offset;
+        int map_ifindex;
         struct bpf_map_def def;
         uint32_t btf_key_id;
         uint32_t btf_value_id;
@@ -1091,6 +1093,7 @@ bpf_object__create_maps(struct bpf_object *obj)
                 int *pfd = &map->fd;
 
                 create_attr.name = map->name;
+                create_attr.map_ifindex = map->map_ifindex;
                 create_attr.map_type = def->type;
                 create_attr.map_flags = def->map_flags;
                 create_attr.key_size = def->key_size;
@@ -1273,7 +1276,7 @@ static int bpf_object__collect_reloc(struct bpf_object *obj)
 static int
 load_program(enum bpf_prog_type type, enum bpf_attach_type expected_attach_type,
              const char *name, struct bpf_insn *insns, int insns_cnt,
-             char *license, u32 kern_version, int *pfd)
+             char *license, u32 kern_version, int *pfd, int prog_ifindex)
 {
         struct bpf_load_program_attr load_attr;
         char *log_buf;
@@ -1287,6 +1290,7 @@ load_program(enum bpf_prog_type type, enum bpf_attach_type expected_attach_type,
         load_attr.insns_cnt = insns_cnt;
         load_attr.license = license;
         load_attr.kern_version = kern_version;
+        load_attr.prog_ifindex = prog_ifindex;
 
         if (!load_attr.insns || !load_attr.insns_cnt)
                 return -EINVAL;
@@ -1368,7 +1372,8 @@ bpf_program__load(struct bpf_program *prog,
                 }
                 err = load_program(prog->type, prog->expected_attach_type,
                                    prog->name, prog->insns, prog->insns_cnt,
-                                   license, kern_version, &fd);
+                                   license, kern_version, &fd,
+                                   prog->prog_ifindex);
                 if (!err)
                         prog->instances.fds[0] = fd;
                 goto out;
@@ -1399,7 +1404,8 @@ bpf_program__load(struct bpf_program *prog,
                 err = load_program(prog->type, prog->expected_attach_type,
                                    prog->name, result.new_insn_ptr,
                                    result.new_insn_cnt,
-                                   license, kern_version, &fd);
+                                   license, kern_version, &fd,
+                                   prog->prog_ifindex);
 
                 if (err) {
                         pr_warning("Loading the %dth instance of program '%s' failed\n",
@@ -2188,6 +2194,7 @@ int bpf_prog_load_xattr(const struct bpf_prog_load_attr *attr,
         enum bpf_attach_type expected_attach_type;
         enum bpf_prog_type prog_type;
         struct bpf_object *obj;
+        struct bpf_map *map;
         int section_idx;
         int err;
 
@@ -2207,6 +2214,7 @@ int bpf_prog_load_xattr(const struct bpf_prog_load_attr *attr,
                  * section name.
                  */
                 prog_type = attr->prog_type;
+                prog->prog_ifindex = attr->ifindex;
                 expected_attach_type = attr->expected_attach_type;
                 if (prog_type == BPF_PROG_TYPE_UNSPEC) {
                         section_idx = bpf_program__identify_section(prog);
@@ -2227,6 +2235,10 @@ int bpf_prog_load_xattr(const struct bpf_prog_load_attr *attr,
                         first_prog = prog;
         }
 
+        bpf_map__for_each(map, obj) {
+                map->map_ifindex = attr->ifindex;
+        }
+
         if (!first_prog) {
                 pr_warning("object file doesn't contain bpf program\n");
                 bpf_object__close(obj);
diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index 4574b9563278..cd3fd8d782c7 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -259,6 +259,7 @@ struct bpf_prog_load_attr {
         const char *file;
         enum bpf_prog_type prog_type;
         enum bpf_attach_type expected_attach_type;
+        int ifindex;
 };
 
 int bpf_prog_load_xattr(const struct bpf_prog_load_attr *attr,