@@ -300,4 +300,15 @@ static inline int bpf_recv_map_fds(const char *path, int *fds,
return -1;
}
#endif /* HAVE_ELF */
+
+#ifdef HAVE_LIBBPF
+int iproute2_bpf_elf_ctx_init(struct bpf_cfg_in *cfg);
+int iproute2_bpf_fetch_ancillary(void);
+int iproute2_get_root_path(char *root_path, size_t len);
+bool iproute2_is_pin_map(const char *libbpf_map_name, char *pathname);
+bool iproute2_is_map_in_map(const char *libbpf_map_name, struct bpf_elf_map *imap,
+ struct bpf_elf_map *omap, char *omap_name);
+int iproute2_find_map_name_by_id(unsigned int map_id, char *name);
+int iproute2_load_libbpf(struct bpf_cfg_in *cfg);
+#endif /* HAVE_LIBBPF */
#endif /* __BPF_UTIL__ */
@@ -7,6 +7,10 @@ UTILOBJ = utils.o rt_names.o ll_map.o ll_types.o ll_proto.o ll_addr.o \
inet_proto.o namespace.o json_writer.o json_print.o \
names.o color.o bpf_legacy.o exec.o fs.o cg_map.o
+ifeq ($(HAVE_LIBBPF),y)
+UTILOBJ += bpf_libbpf.o
+endif
+
NLOBJ=libgenl.o libnetlink.o
all: libnetlink.a libutil.a
@@ -940,6 +940,9 @@ static int bpf_do_parse(struct bpf_cfg_in *cfg, const bool *opt_tbl)
static int bpf_do_load(struct bpf_cfg_in *cfg)
{
if (cfg->mode == EBPF_OBJECT) {
+#ifdef HAVE_LIBBPF
+ return iproute2_load_libbpf(cfg);
+#endif
cfg->prog_fd = bpf_obj_open(cfg->object, cfg->type,
cfg->section, cfg->ifindex,
cfg->verbose);
@@ -3165,3 +3168,178 @@ int bpf_recv_map_fds(const char *path, int *fds, struct bpf_map_aux *aux,
return ret;
}
#endif /* HAVE_ELF */
+
+#ifdef HAVE_LIBBPF
+/* The following functions are wrapper functions for libbpf code to be
+ * compatible with the legacy format. So all the functions have prefix
+ * with iproute2_
+ */
+int iproute2_bpf_elf_ctx_init(struct bpf_cfg_in *cfg)
+{
+ struct bpf_elf_ctx *ctx = &__ctx;
+
+ return bpf_elf_ctx_init(ctx, cfg->object, cfg->type, cfg->ifindex, cfg->verbose);
+}
+
+int iproute2_bpf_fetch_ancillary(void)
+{
+ struct bpf_elf_ctx *ctx = &__ctx;
+ struct bpf_elf_sec_data data;
+ int i, ret = 0;
+
+ for (i = 1; i < ctx->elf_hdr.e_shnum; i++) {
+ ret = bpf_fill_section_data(ctx, i, &data);
+ if (ret < 0)
+ continue;
+
+ if (data.sec_hdr.sh_type == SHT_PROGBITS &&
+ !strcmp(data.sec_name, ELF_SECTION_MAPS))
+ ret = bpf_fetch_maps_begin(ctx, i, &data);
+ else if (data.sec_hdr.sh_type == SHT_SYMTAB &&
+ !strcmp(data.sec_name, ".symtab"))
+ ret = bpf_fetch_symtab(ctx, i, &data);
+ else if (data.sec_hdr.sh_type == SHT_STRTAB &&
+ !strcmp(data.sec_name, ".strtab"))
+ ret = bpf_fetch_strtab(ctx, i, &data);
+ if (ret < 0) {
+ fprintf(stderr, "Error parsing section %d! Perhaps check with readelf -a?\n",
+ i);
+ return ret;
+ }
+ }
+
+ if (bpf_has_map_data(ctx)) {
+ ret = bpf_fetch_maps_end(ctx);
+ if (ret < 0) {
+ fprintf(stderr, "Error fixing up map structure, incompatible struct bpf_elf_map used?\n");
+ return ret;
+ }
+ }
+
+ return ret;
+}
+
+int iproute2_get_root_path(char *root_path, size_t len)
+{
+ struct bpf_elf_ctx *ctx = &__ctx;
+ int ret = 0;
+
+ snprintf(root_path, len, "%s/%s",
+ bpf_get_work_dir(ctx->type), BPF_DIR_GLOBALS);
+
+ ret = mkdir(root_path, S_IRWXU);
+ if (ret && errno != EEXIST) {
+ fprintf(stderr, "mkdir %s failed: %s\n", root_path, strerror(errno));
+ return ret;
+ }
+
+ return 0;
+}
+
+bool iproute2_is_pin_map(const char *libbpf_map_name, char *pathname)
+{
+ struct bpf_elf_ctx *ctx = &__ctx;
+ const char *map_name, *tmp;
+ unsigned int pinning;
+ int i, ret = 0;
+
+ for (i = 0; i < ctx->map_num; i++) {
+ if (ctx->maps[i].pinning == PIN_OBJECT_NS &&
+ ctx->noafalg) {
+ fprintf(stderr, "Missing kernel AF_ALG support for PIN_OBJECT_NS!\n");
+ return false;
+ }
+
+ map_name = bpf_map_fetch_name(ctx, i);
+ if (!map_name) {
+ return false;
+ }
+
+ if (strcmp(libbpf_map_name, map_name))
+ continue;
+
+ pinning = ctx->maps[i].pinning;
+
+ if (bpf_no_pinning(ctx, pinning) || !bpf_get_work_dir(ctx->type))
+ return false;
+
+ if (pinning == PIN_OBJECT_NS)
+ ret = bpf_make_obj_path(ctx);
+ else if ((tmp = bpf_custom_pinning(ctx, pinning)))
+ ret = bpf_make_custom_path(ctx, tmp);
+ if (ret < 0)
+ return false;
+
+ bpf_make_pathname(pathname, PATH_MAX, map_name, ctx, pinning);
+
+ return true;
+ }
+
+ return false;
+}
+
+bool iproute2_is_map_in_map(const char *libbpf_map_name, struct bpf_elf_map *imap,
+ struct bpf_elf_map *omap, char *omap_name)
+{
+ struct bpf_elf_ctx *ctx = &__ctx;
+ const char *inner_map_name, *outer_map_name;
+ int i, j;
+
+ for (i = 0; i < ctx->map_num; i++) {
+ inner_map_name = bpf_map_fetch_name(ctx, i);
+ if (!inner_map_name) {
+ return false;
+ }
+
+ if (strcmp(libbpf_map_name, inner_map_name))
+ continue;
+
+ if (!ctx->maps[i].id ||
+ ctx->maps[i].inner_id ||
+ ctx->maps[i].inner_idx == -1)
+ continue;
+
+ *imap = ctx->maps[i];
+
+ for (j = 0; j < ctx->map_num; j++) {
+ if (!bpf_is_map_in_map_type(&ctx->maps[j]))
+ continue;
+ if (ctx->maps[j].inner_id != ctx->maps[i].id)
+ continue;
+
+ *omap = ctx->maps[j];
+ outer_map_name = bpf_map_fetch_name(ctx, j);
+ memcpy(omap_name, outer_map_name, strlen(outer_map_name) + 1);
+
+ return true;
+ }
+ }
+
+ return false;
+}
+
+int iproute2_find_map_name_by_id(unsigned int map_id, char *name)
+{
+ struct bpf_elf_ctx *ctx = &__ctx;
+ const char *map_name;
+ int i, idx = -1;
+
+ for (i = 0; i < ctx->map_num; i++) {
+ if (ctx->maps[i].id == map_id &&
+ ctx->maps[i].type == BPF_MAP_TYPE_PROG_ARRAY) {
+ idx = i;
+ break;
+ }
+ }
+
+ if (idx < 0)
+ return -1;
+
+ map_name = bpf_map_fetch_name(ctx, idx);
+ if (!map_name)
+ return -1;
+
+ memcpy(name, map_name, strlen(map_name) + 1);
+ return 0;
+}
+#endif /* HAVE_LIBBPF */
new file mode 100644
@@ -0,0 +1,338 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <errno.h>
+#include <fcntl.h>
+
+#include <libelf.h>
+#include <gelf.h>
+
+#include <bpf/libbpf.h>
+#include <bpf/bpf.h>
+
+#include "bpf_util.h"
+
+#define MAX_ERRNO 4095
+#define IS_ERR_VALUE(x) ((x) >= (unsigned long)-MAX_ERRNO)
+
+static inline bool IS_ERR_OR_NULL(const void *ptr)
+{
+ return (!ptr) || IS_ERR_VALUE((unsigned long)ptr);
+}
+
+static int verbose_print(enum libbpf_print_level level, const char *format, va_list args)
+{
+ return vfprintf(stderr, format, args);
+}
+
+static int silent_print(enum libbpf_print_level level, const char *format, va_list args)
+{
+ if (level > LIBBPF_WARN)
+ return 0;
+
+ /* Skip warning from bpf_object__init_user_maps() for legacy maps */
+ if (strstr(format, "has unrecognized, non-zero options"))
+ return 0;
+
+ return vfprintf(stderr, format, args);
+}
+
+static int create_map(const char *name, struct bpf_elf_map *map,
+ __u32 ifindex, int inner_fd)
+{
+ struct bpf_create_map_attr map_attr = {};
+
+ map_attr.name = name;
+ map_attr.map_type = map->type;
+ map_attr.map_flags = map->flags;
+ map_attr.key_size = map->size_key;
+ map_attr.value_size = map->size_value;
+ map_attr.max_entries = map->max_elem;
+ map_attr.map_ifindex = ifindex;
+ map_attr.inner_map_fd = inner_fd;
+
+ return bpf_create_map_xattr(&map_attr);
+}
+
+static int create_map_in_map(struct bpf_object *obj, struct bpf_map *map,
+ struct bpf_elf_map *elf_map, int inner_fd,
+ bool *reuse_pin_map)
+{
+ char pathname[PATH_MAX];
+ const char *map_name;
+ bool pin_map = false;
+ int map_fd, ret = 0;
+
+ map_name = bpf_map__name(map);
+
+ if (iproute2_is_pin_map(map_name, pathname)) {
+ pin_map = true;
+
+ /* Check if there already has a pinned map */
+ map_fd = bpf_obj_get(pathname);
+ if (map_fd > 0) {
+ if (reuse_pin_map)
+ *reuse_pin_map = true;
+ close(map_fd);
+ return bpf_map__set_pin_path(map, pathname);
+ }
+ }
+
+ map_fd = create_map(map_name, elf_map, bpf_map__ifindex(map), inner_fd);
+ if (map_fd < 0) {
+ fprintf(stderr, "create map %s failed\n", map_name);
+ return map_fd;
+ }
+
+ ret = bpf_map__reuse_fd(map, map_fd);
+ if (ret < 0) {
+ fprintf(stderr, "map %s reuse fd failed\n", map_name);
+ goto err_out;
+ }
+
+ if (pin_map) {
+ ret = bpf_map__set_pin_path(map, pathname);
+ if (ret < 0)
+ goto err_out;
+ }
+
+ return 0;
+err_out:
+ close(map_fd);
+ return ret;
+}
+
+static int
+handle_legacy_map_in_map(struct bpf_object *obj, struct bpf_map *inner_map,
+ const char *inner_map_name)
+{
+ int inner_fd, outer_fd, inner_idx, ret = 0;
+ struct bpf_elf_map imap, omap;
+ struct bpf_map *outer_map;
+ /* What's the size limit of map name? */
+ char outer_map_name[128];
+ bool reuse_pin_map = false;
+
+ /* Deal with map-in-map */
+ if (iproute2_is_map_in_map(inner_map_name, &imap, &omap, outer_map_name)) {
+ ret = create_map_in_map(obj, inner_map, &imap, -1, NULL);
+ if (ret < 0)
+ return ret;
+
+ inner_fd = bpf_map__fd(inner_map);
+ outer_map = bpf_object__find_map_by_name(obj, outer_map_name);
+ ret = create_map_in_map(obj, outer_map, &omap, inner_fd, &reuse_pin_map);
+ if (ret < 0)
+ return ret;
+
+ if (!reuse_pin_map) {
+ inner_idx = imap.inner_idx;
+ outer_fd = bpf_map__fd(outer_map);
+ ret = bpf_map_update_elem(outer_fd, &inner_idx, &inner_fd, 0);
+ if (ret < 0)
+ fprintf(stderr, "Cannot update inner_idx into outer_map\n");
+ }
+ }
+
+ return ret;
+}
+
+static int find_legacy_tail_calls(struct bpf_program *prog, struct bpf_object *obj)
+{
+ unsigned int map_id, key_id;
+ const char *sec_name;
+ struct bpf_map *map;
+ char map_name[128];
+ int ret;
+
+ /* Handle iproute2 tail call */
+ sec_name = bpf_program__section_name(prog);
+ ret = sscanf(sec_name, "%i/%i", &map_id, &key_id);
+ if (ret != 2)
+ return -1;
+
+ ret = iproute2_find_map_name_by_id(map_id, map_name);
+ if (ret < 0) {
+ fprintf(stderr, "unable to find map id %u for tail call\n", map_id);
+ return ret;
+ }
+
+ map = bpf_object__find_map_by_name(obj, map_name);
+ if (!map)
+ return -1;
+
+ /* Save the map here for later updating */
+ bpf_program__set_priv(prog, map, NULL);
+
+ return 0;
+}
+
+static int update_legacy_tail_call_maps(struct bpf_object *obj)
+{
+ int prog_fd, map_fd, ret = 0;
+ unsigned int map_id, key_id;
+ struct bpf_program *prog;
+ const char *sec_name;
+ struct bpf_map *map;
+
+ bpf_object__for_each_program(prog, obj) {
+ map = bpf_program__priv(prog);
+ if (!map)
+ continue;
+
+ prog_fd = bpf_program__fd(prog);
+ if (prog_fd < 0)
+ continue;
+
+ sec_name = bpf_program__section_name(prog);
+ ret = sscanf(sec_name, "%i/%i", &map_id, &key_id);
+ if (ret != 2)
+ continue;
+
+ map_fd = bpf_map__fd(map);
+ ret = bpf_map_update_elem(map_fd, &key_id, &prog_fd, 0);
+ if (ret < 0) {
+ fprintf(stderr, "Cannot update map key for tail call!\n");
+ return ret;
+ }
+ }
+
+ return 0;
+}
+
+static int handle_legacy_maps(struct bpf_object *obj)
+{
+ char pathname[PATH_MAX];
+ struct bpf_map *map;
+ const char *map_name;
+ int map_fd, ret = 0;
+
+ bpf_object__for_each_map(map, obj) {
+ map_name = bpf_map__name(map);
+
+ ret = handle_legacy_map_in_map(obj, map, map_name);
+ if (ret)
+ return ret;
+
+ /* If it is a iproute2 legacy pin maps, just set pin path
+ * and let bpf_object__load() to deal with the map creation.
+ * We need to ignore map-in-maps which have pinned maps manually
+ */
+ map_fd = bpf_map__fd(map);
+ if (map_fd < 0 && iproute2_is_pin_map(map_name, pathname)) {
+ ret = bpf_map__set_pin_path(map, pathname);
+ if (ret) {
+ fprintf(stderr, "map '%s': couldn't set pin path.\n", map_name);
+ break;
+ }
+ }
+
+ }
+
+ return ret;
+}
+
+static int load_bpf_object(struct bpf_cfg_in *cfg)
+{
+ struct bpf_program *p, *prog = NULL;
+ struct bpf_object *obj;
+ char root_path[PATH_MAX];
+ struct bpf_map *map;
+ int prog_fd, ret = 0;
+
+ ret = iproute2_get_root_path(root_path, PATH_MAX);
+ if (ret)
+ return ret;
+
+ DECLARE_LIBBPF_OPTS(bpf_object_open_opts, open_opts,
+ .relaxed_maps = true,
+ .pin_root_path = root_path,
+ );
+
+ obj = bpf_object__open_file(cfg->object, &open_opts);
+ if (IS_ERR_OR_NULL(obj))
+ return -ENOENT;
+
+ bpf_object__for_each_program(p, obj) {
+ /* Only load the programs that will either be subsequently
+ * attached or inserted into a tail call map */
+ if (find_legacy_tail_calls(p, obj) < 0 && cfg->section &&
+ strcmp(bpf_program__section_name(p), cfg->section)) {
+ ret = bpf_program__set_autoload(p, false);
+ if (ret)
+ return -EINVAL;
+ continue;
+ }
+
+ bpf_program__set_type(p, cfg->type);
+ bpf_program__set_ifindex(p, cfg->ifindex);
+ if (!prog)
+ prog = p;
+ }
+
+ bpf_object__for_each_map(map, obj) {
+ if (!bpf_map__is_offload_neutral(map))
+ bpf_map__set_ifindex(map, cfg->ifindex);
+ }
+
+ if (!prog) {
+ fprintf(stderr, "object file doesn't contain sec %s\n", cfg->section);
+ return -ENOENT;
+ }
+
+ /* Handle iproute2 legacy pin maps and map-in-maps */
+ ret = handle_legacy_maps(obj);
+ if (ret)
+ goto unload_obj;
+
+ ret = bpf_object__load(obj);
+ if (ret)
+ goto unload_obj;
+
+ ret = update_legacy_tail_call_maps(obj);
+ if (ret)
+ goto unload_obj;
+
+ prog_fd = fcntl(bpf_program__fd(prog), F_DUPFD_CLOEXEC, 1);
+ if (prog_fd < 0)
+ ret = -errno;
+ else
+ cfg->prog_fd = prog_fd;
+
+unload_obj:
+ /* Close obj as we don't need it */
+ bpf_object__close(obj);
+ return ret;
+}
+
+/* Load ebpf and return prog fd */
+int iproute2_load_libbpf(struct bpf_cfg_in *cfg)
+{
+ int ret = 0;
+
+ if (cfg->verbose)
+ libbpf_set_print(verbose_print);
+ else
+ libbpf_set_print(silent_print);
+
+ ret = iproute2_bpf_elf_ctx_init(cfg);
+ if (ret < 0) {
+ fprintf(stderr, "Cannot initialize ELF context!\n");
+ return ret;
+ }
+
+ ret = iproute2_bpf_fetch_ancillary();
+ if (ret < 0) {
+ fprintf(stderr, "Error fetching ELF ancillary data!\n");
+ return ret;
+ }
+
+ ret = load_bpf_object(cfg);
+ if (ret)
+ return ret;
+
+ return cfg->prog_fd;
+}