diff options
Diffstat (limited to 'src/xdp/common/common_libbpf.c')
| -rw-r--r-- | src/xdp/common/common_libbpf.c | 162 |
1 files changed, 162 insertions, 0 deletions
diff --git a/src/xdp/common/common_libbpf.c b/src/xdp/common/common_libbpf.c new file mode 100644 index 000000000..5788ecd9e --- /dev/null +++ b/src/xdp/common/common_libbpf.c @@ -0,0 +1,162 @@ +/* Common function that with time should be moved to libbpf */ + +#include <errno.h> +#include <string.h> + +#include <bpf/bpf.h> +#include <bpf/libbpf.h> + +#include "common_libbpf.h" + +/* From: include/linux/err.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); +} + +#define pr_warning printf + +/* As close as possible to libbpf bpf_prog_load_xattr(), with the + * difference of handling pinned maps. + */ +int bpf_prog_load_xattr_maps(const struct bpf_prog_load_attr_maps *attr, + struct bpf_object **pobj, int *prog_fd) +{ + struct bpf_object_open_attr open_attr = { + .file = attr->file, + .prog_type = attr->prog_type, + }; + struct bpf_program *prog, *first_prog = NULL; + enum bpf_attach_type expected_attach_type; + enum bpf_prog_type prog_type; + struct bpf_object *obj; + struct bpf_map *map; + int err; + int i; + + if (!attr) + return -EINVAL; + if (!attr->file) + return -EINVAL; + + + obj = bpf_object__open_xattr(&open_attr); + if (IS_ERR_OR_NULL(obj)) + return -ENOENT; + + bpf_object__for_each_program(prog, obj) { + /* + * If type is not specified, try to guess it based on + * section name. + */ + prog_type = attr->prog_type; + // Was: prog->prog_ifindex = attr->ifindex; + bpf_program__set_ifindex(prog, attr->ifindex); + + expected_attach_type = attr->expected_attach_type; +#if 0 /* Use internal libbpf variables */ + if (prog_type == BPF_PROG_TYPE_UNSPEC) { + err = bpf_program__identify_section(prog, &prog_type, + &expected_attach_type); + if (err < 0) { + bpf_object__close(obj); + return -EINVAL; + } + } +#endif + + bpf_program__set_type(prog, prog_type); + bpf_program__set_expected_attach_type(prog, + expected_attach_type); + + if (!first_prog) + first_prog = prog; + } + + /* Reset attr->pinned_maps.map_fd to identify successful file load */ + for (i = 0; i < attr->nr_pinned_maps; i++) + attr->pinned_maps[i].map_fd = -1; + + bpf_map__for_each(map, obj) { + const char* mapname = bpf_map__name(map); + + if (!bpf_map__is_offload_neutral(map)) + bpf_map__set_ifindex(map, attr->ifindex); + /* Was: map->map_ifindex = attr->ifindex; */ + + for (i = 0; i < attr->nr_pinned_maps; i++) { + struct bpf_pinned_map *pin_map = &attr->pinned_maps[i]; + int fd; + + if (strcmp(mapname, pin_map->name) != 0) + continue; + + /* Matched, try opening pinned file */ + fd = bpf_obj_get(pin_map->filename); + if (fd > 0) { + /* Use FD from pinned map as replacement */ + bpf_map__reuse_fd(map, fd); + /* TODO: Might want to set internal map "name" + * if opened pinned map didn't, to allow + * bpf_object__find_map_fd_by_name() to work. + */ + pin_map->map_fd = fd; + continue; + } + /* Could not open pinned filename map, then this prog + * should then pin the map, BUT this can only happen + * after bpf_object__load(). + */ + } + } + + if (!first_prog) { + pr_warning("object file doesn't contain bpf program\n"); + bpf_object__close(obj); + return -ENOENT; + } + + err = bpf_object__load(obj); + if (err) { + bpf_object__close(obj); + return -EINVAL; + } + + /* Pin the maps that were not loaded via pinned filename */ + bpf_map__for_each(map, obj) { + const char* mapname = bpf_map__name(map); + + for (i = 0; i < attr->nr_pinned_maps; i++) { + struct bpf_pinned_map *pin_map = &attr->pinned_maps[i]; + int err; + + if (strcmp(mapname, pin_map->name) != 0) + continue; + + /* Matched, check if map is already loaded */ + if (pin_map->map_fd != -1) + continue; + + /* Needs to be pinned */ + err = bpf_map__pin(map, pin_map->filename); + if (err) + continue; + pin_map->map_fd = bpf_map__fd(map); + } + } + + /* Help user if requested map name that doesn't exist */ + for (i = 0; i < attr->nr_pinned_maps; i++) { + struct bpf_pinned_map *pin_map = &attr->pinned_maps[i]; + + if (pin_map->map_fd < 0) + pr_warning("%s() requested mapname:%s not seen\n", + __func__, pin_map->name); + } + + *pobj = obj; + *prog_fd = bpf_program__fd(first_prog); + return 0; +} |