| /* |
| * bpf.c BPF common code |
| * |
| * This program is free software; you can distribute it and/or |
| * modify it under the terms of the GNU General Public License |
| * as published by the Free Software Foundation; either version |
| * 2 of the License, or (at your option) any later version. |
| * |
| * Authors: Daniel Borkmann <daniel@iogearbox.net> |
| * Jiri Pirko <jiri@resnulli.us> |
| * Alexei Starovoitov <ast@kernel.org> |
| */ |
| |
| #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 <stdarg.h> |
| #include <limits.h> |
| #include <assert.h> |
| |
| #ifdef HAVE_ELF |
| #include <libelf.h> |
| #include <gelf.h> |
| #endif |
| |
| #include <sys/types.h> |
| #include <sys/stat.h> |
| #include <sys/un.h> |
| #include <sys/vfs.h> |
| #include <sys/mount.h> |
| #include <sys/syscall.h> |
| #include <sys/sendfile.h> |
| #include <sys/resource.h> |
| |
| #include <arpa/inet.h> |
| |
| #include "utils.h" |
| #include "json_print.h" |
| |
| #include "bpf_util.h" |
| #include "bpf_elf.h" |
| #include "bpf_scm.h" |
| |
| struct bpf_prog_meta { |
| const char *type; |
| const char *subdir; |
| const char *section; |
| bool may_uds_export; |
| }; |
| |
| static const enum bpf_prog_type __bpf_types[] = { |
| BPF_PROG_TYPE_SCHED_CLS, |
| BPF_PROG_TYPE_SCHED_ACT, |
| BPF_PROG_TYPE_XDP, |
| BPF_PROG_TYPE_LWT_IN, |
| BPF_PROG_TYPE_LWT_OUT, |
| BPF_PROG_TYPE_LWT_XMIT, |
| }; |
| |
| static const struct bpf_prog_meta __bpf_prog_meta[] = { |
| [BPF_PROG_TYPE_SCHED_CLS] = { |
| .type = "cls", |
| .subdir = "tc", |
| .section = ELF_SECTION_CLASSIFIER, |
| .may_uds_export = true, |
| }, |
| [BPF_PROG_TYPE_SCHED_ACT] = { |
| .type = "act", |
| .subdir = "tc", |
| .section = ELF_SECTION_ACTION, |
| .may_uds_export = true, |
| }, |
| [BPF_PROG_TYPE_XDP] = { |
| .type = "xdp", |
| .subdir = "xdp", |
| .section = ELF_SECTION_PROG, |
| }, |
| [BPF_PROG_TYPE_LWT_IN] = { |
| .type = "lwt_in", |
| .subdir = "ip", |
| .section = ELF_SECTION_PROG, |
| }, |
| [BPF_PROG_TYPE_LWT_OUT] = { |
| .type = "lwt_out", |
| .subdir = "ip", |
| .section = ELF_SECTION_PROG, |
| }, |
| [BPF_PROG_TYPE_LWT_XMIT] = { |
| .type = "lwt_xmit", |
| .subdir = "ip", |
| .section = ELF_SECTION_PROG, |
| }, |
| [BPF_PROG_TYPE_LWT_SEG6LOCAL] = { |
| .type = "lwt_seg6local", |
| .subdir = "ip", |
| .section = ELF_SECTION_PROG, |
| }, |
| }; |
| |
| static const char *bpf_prog_to_subdir(enum bpf_prog_type type) |
| { |
| assert(type < ARRAY_SIZE(__bpf_prog_meta) && |
| __bpf_prog_meta[type].subdir); |
| return __bpf_prog_meta[type].subdir; |
| } |
| |
| const char *bpf_prog_to_default_section(enum bpf_prog_type type) |
| { |
| assert(type < ARRAY_SIZE(__bpf_prog_meta) && |
| __bpf_prog_meta[type].section); |
| return __bpf_prog_meta[type].section; |
| } |
| |
| #ifdef HAVE_ELF |
| static int bpf_obj_open(const char *path, enum bpf_prog_type type, |
| const char *sec, __u32 ifindex, bool verbose); |
| #else |
| static int bpf_obj_open(const char *path, enum bpf_prog_type type, |
| const char *sec, __u32 ifindex, bool verbose) |
| { |
| fprintf(stderr, "No ELF library support compiled in.\n"); |
| errno = ENOSYS; |
| return -1; |
| } |
| #endif |
| |
| static inline __u64 bpf_ptr_to_u64(const void *ptr) |
| { |
| return (__u64)(unsigned long)ptr; |
| } |
| |
| static int bpf(int cmd, union bpf_attr *attr, unsigned int size) |
| { |
| #ifdef __NR_bpf |
| return syscall(__NR_bpf, cmd, attr, size); |
| #else |
| fprintf(stderr, "No bpf syscall, kernel headers too old?\n"); |
| errno = ENOSYS; |
| return -1; |
| #endif |
| } |
| |
| static int bpf_map_update(int fd, const void *key, const void *value, |
| uint64_t flags) |
| { |
| union bpf_attr attr = {}; |
| |
| attr.map_fd = fd; |
| attr.key = bpf_ptr_to_u64(key); |
| attr.value = bpf_ptr_to_u64(value); |
| attr.flags = flags; |
| |
| return bpf(BPF_MAP_UPDATE_ELEM, &attr, sizeof(attr)); |
| } |
| |
| static int bpf_prog_fd_by_id(uint32_t id) |
| { |
| union bpf_attr attr = {}; |
| |
| attr.prog_id = id; |
| |
| return bpf(BPF_PROG_GET_FD_BY_ID, &attr, sizeof(attr)); |
| } |
| |
| static int bpf_prog_info_by_fd(int fd, struct bpf_prog_info *info, |
| uint32_t *info_len) |
| { |
| union bpf_attr attr = {}; |
| int ret; |
| |
| attr.info.bpf_fd = fd; |
| attr.info.info = bpf_ptr_to_u64(info); |
| attr.info.info_len = *info_len; |
| |
| *info_len = 0; |
| ret = bpf(BPF_OBJ_GET_INFO_BY_FD, &attr, sizeof(attr)); |
| if (!ret) |
| *info_len = attr.info.info_len; |
| |
| return ret; |
| } |
| |
| int bpf_dump_prog_info(FILE *f, uint32_t id) |
| { |
| struct bpf_prog_info info = {}; |
| uint32_t len = sizeof(info); |
| int fd, ret, dump_ok = 0; |
| SPRINT_BUF(tmp); |
| |
| open_json_object("prog"); |
| print_uint(PRINT_ANY, "id", "id %u ", id); |
| |
| fd = bpf_prog_fd_by_id(id); |
| if (fd < 0) |
| goto out; |
| |
| ret = bpf_prog_info_by_fd(fd, &info, &len); |
| if (!ret && len) { |
| int jited = !!info.jited_prog_len; |
| |
| print_string(PRINT_ANY, "tag", "tag %s ", |
| hexstring_n2a(info.tag, sizeof(info.tag), |
| tmp, sizeof(tmp))); |
| print_uint(PRINT_JSON, "jited", NULL, jited); |
| if (jited && !is_json_context()) |
| fprintf(f, "jited "); |
| dump_ok = 1; |
| } |
| |
| close(fd); |
| out: |
| close_json_object(); |
| return dump_ok; |
| } |
| |
| static int bpf_parse_string(char *arg, bool from_file, __u16 *bpf_len, |
| char **bpf_string, bool *need_release, |
| const char separator) |
| { |
| char sp; |
| |
| if (from_file) { |
| size_t tmp_len, op_len = sizeof("65535 255 255 4294967295,"); |
| char *tmp_string, *pos, c_prev = ' '; |
| FILE *fp; |
| int c; |
| |
| tmp_len = sizeof("4096,") + BPF_MAXINSNS * op_len; |
| tmp_string = pos = calloc(1, tmp_len); |
| if (tmp_string == NULL) |
| return -ENOMEM; |
| |
| fp = fopen(arg, "r"); |
| if (fp == NULL) { |
| perror("Cannot fopen"); |
| free(tmp_string); |
| return -ENOENT; |
| } |
| |
| while ((c = fgetc(fp)) != EOF) { |
| switch (c) { |
| case '\n': |
| if (c_prev != ',') |
| *(pos++) = ','; |
| c_prev = ','; |
| break; |
| case ' ': |
| case '\t': |
| if (c_prev != ' ') |
| *(pos++) = c; |
| c_prev = ' '; |
| break; |
| default: |
| *(pos++) = c; |
| c_prev = c; |
| } |
| if (pos - tmp_string == tmp_len) |
| break; |
| } |
| |
| if (!feof(fp)) { |
| free(tmp_string); |
| fclose(fp); |
| return -E2BIG; |
| } |
| |
| fclose(fp); |
| *pos = 0; |
| |
| *need_release = true; |
| *bpf_string = tmp_string; |
| } else { |
| *need_release = false; |
| *bpf_string = arg; |
| } |
| |
| if (sscanf(*bpf_string, "%hu%c", bpf_len, &sp) != 2 || |
| sp != separator) { |
| if (*need_release) |
| free(*bpf_string); |
| return -EINVAL; |
| } |
| |
| return 0; |
| } |
| |
| static int bpf_ops_parse(int argc, char **argv, struct sock_filter *bpf_ops, |
| bool from_file) |
| { |
| char *bpf_string, *token, separator = ','; |
| int ret = 0, i = 0; |
| bool need_release; |
| __u16 bpf_len = 0; |
| |
| if (argc < 1) |
| return -EINVAL; |
| if (bpf_parse_string(argv[0], from_file, &bpf_len, &bpf_string, |
| &need_release, separator)) |
| return -EINVAL; |
| if (bpf_len == 0 || bpf_len > BPF_MAXINSNS) { |
| ret = -EINVAL; |
| goto out; |
| } |
| |
| token = bpf_string; |
| while ((token = strchr(token, separator)) && (++token)[0]) { |
| if (i >= bpf_len) { |
| fprintf(stderr, "Real program length exceeds encoded length parameter!\n"); |
| ret = -EINVAL; |
| goto out; |
| } |
| |
| if (sscanf(token, "%hu %hhu %hhu %u,", |
| &bpf_ops[i].code, &bpf_ops[i].jt, |
| &bpf_ops[i].jf, &bpf_ops[i].k) != 4) { |
| fprintf(stderr, "Error at instruction %d!\n", i); |
| ret = -EINVAL; |
| goto out; |
| } |
| |
| i++; |
| } |
| |
| if (i != bpf_len) { |
| fprintf(stderr, "Parsed program length is less than encoded length parameter!\n"); |
| ret = -EINVAL; |
| goto out; |
| } |
| ret = bpf_len; |
| out: |
| if (need_release) |
| free(bpf_string); |
| |
| return ret; |
| } |
| |
| void bpf_print_ops(struct rtattr *bpf_ops, __u16 len) |
| { |
| struct sock_filter *ops = RTA_DATA(bpf_ops); |
| int i; |
| |
| if (len == 0) |
| return; |
| |
| open_json_object("bytecode"); |
| print_uint(PRINT_ANY, "length", "bytecode \'%u,", len); |
| open_json_array(PRINT_JSON, "insns"); |
| |
| for (i = 0; i < len; i++) { |
| open_json_object(NULL); |
| print_hu(PRINT_ANY, "code", "%hu ", ops[i].code); |
| print_hhu(PRINT_ANY, "jt", "%hhu ", ops[i].jt); |
| print_hhu(PRINT_ANY, "jf", "%hhu ", ops[i].jf); |
| if (i == len - 1) |
| print_uint(PRINT_ANY, "k", "%u\'", ops[i].k); |
| else |
| print_uint(PRINT_ANY, "k", "%u,", ops[i].k); |
| close_json_object(); |
| } |
| |
| close_json_array(PRINT_JSON, NULL); |
| close_json_object(); |
| } |
| |
| static void bpf_map_pin_report(const struct bpf_elf_map *pin, |
| const struct bpf_elf_map *obj) |
| { |
| fprintf(stderr, "Map specification differs from pinned file!\n"); |
| |
| if (obj->type != pin->type) |
| fprintf(stderr, " - Type: %u (obj) != %u (pin)\n", |
| obj->type, pin->type); |
| if (obj->size_key != pin->size_key) |
| fprintf(stderr, " - Size key: %u (obj) != %u (pin)\n", |
| obj->size_key, pin->size_key); |
| if (obj->size_value != pin->size_value) |
| fprintf(stderr, " - Size value: %u (obj) != %u (pin)\n", |
| obj->size_value, pin->size_value); |
| if (obj->max_elem != pin->max_elem) |
| fprintf(stderr, " - Max elems: %u (obj) != %u (pin)\n", |
| obj->max_elem, pin->max_elem); |
| if (obj->flags != pin->flags) |
| fprintf(stderr, " - Flags: %#x (obj) != %#x (pin)\n", |
| obj->flags, pin->flags); |
| |
| fprintf(stderr, "\n"); |
| } |
| |
| struct bpf_prog_data { |
| unsigned int type; |
| unsigned int jited; |
| }; |
| |
| struct bpf_map_ext { |
| struct bpf_prog_data owner; |
| unsigned int btf_id_key; |
| unsigned int btf_id_val; |
| }; |
| |
| static int bpf_derive_elf_map_from_fdinfo(int fd, struct bpf_elf_map *map, |
| struct bpf_map_ext *ext) |
| { |
| unsigned int val, owner_type = 0, owner_jited = 0; |
| char *file = NULL; |
| char buff[4096]; |
| FILE *fp; |
| int ret; |
| |
| ret = asprintf(&file, "/proc/%d/fdinfo/%d", getpid(), fd); |
| if (ret < 0) { |
| fprintf(stderr, "asprintf failed: %s\n", strerror(errno)); |
| free(file); |
| return ret; |
| } |
| memset(map, 0, sizeof(*map)); |
| |
| fp = fopen(file, "r"); |
| free(file); |
| if (!fp) { |
| fprintf(stderr, "No procfs support?!\n"); |
| return -EIO; |
| } |
| |
| while (fgets(buff, sizeof(buff), fp)) { |
| if (sscanf(buff, "map_type:\t%u", &val) == 1) |
| map->type = val; |
| else if (sscanf(buff, "key_size:\t%u", &val) == 1) |
| map->size_key = val; |
| else if (sscanf(buff, "value_size:\t%u", &val) == 1) |
| map->size_value = val; |
| else if (sscanf(buff, "max_entries:\t%u", &val) == 1) |
| map->max_elem = val; |
| else if (sscanf(buff, "map_flags:\t%i", &val) == 1) |
| map->flags = val; |
| else if (sscanf(buff, "owner_prog_type:\t%i", &val) == 1) |
| owner_type = val; |
| else if (sscanf(buff, "owner_jited:\t%i", &val) == 1) |
| owner_jited = val; |
| } |
| |
| fclose(fp); |
| if (ext) { |
| memset(ext, 0, sizeof(*ext)); |
| ext->owner.type = owner_type; |
| ext->owner.jited = owner_jited; |
| } |
| |
| return 0; |
| } |
| |
| static int bpf_map_selfcheck_pinned(int fd, const struct bpf_elf_map *map, |
| struct bpf_map_ext *ext, int length, |
| enum bpf_prog_type type) |
| { |
| struct bpf_elf_map tmp, zero = {}; |
| int ret; |
| |
| ret = bpf_derive_elf_map_from_fdinfo(fd, &tmp, ext); |
| if (ret < 0) |
| return ret; |
| |
| /* The decision to reject this is on kernel side eventually, but |
| * at least give the user a chance to know what's wrong. |
| */ |
| if (ext->owner.type && ext->owner.type != type) |
| fprintf(stderr, "Program array map owner types differ: %u (obj) != %u (pin)\n", |
| type, ext->owner.type); |
| |
| if (!memcmp(&tmp, map, length)) { |
| return 0; |
| } else { |
| /* If kernel doesn't have eBPF-related fdinfo, we cannot do much, |
| * so just accept it. We know we do have an eBPF fd and in this |
| * case, everything is 0. It is guaranteed that no such map exists |
| * since map type of 0 is unloadable BPF_MAP_TYPE_UNSPEC. |
| */ |
| if (!memcmp(&tmp, &zero, length)) |
| return 0; |
| |
| bpf_map_pin_report(&tmp, map); |
| return -EINVAL; |
| } |
| } |
| |
| static int bpf_mnt_fs(const char *target) |
| { |
| bool bind_done = false; |
| |
| while (mount("", target, "none", MS_PRIVATE | MS_REC, NULL)) { |
| if (errno != EINVAL || bind_done) { |
| fprintf(stderr, "mount --make-private %s failed: %s\n", |
| target, strerror(errno)); |
| return -1; |
| } |
| |
| if (mount(target, target, "none", MS_BIND, NULL)) { |
| fprintf(stderr, "mount --bind %s %s failed: %s\n", |
| target, target, strerror(errno)); |
| return -1; |
| } |
| |
| bind_done = true; |
| } |
| |
| if (mount("bpf", target, "bpf", 0, "mode=0700")) { |
| fprintf(stderr, "mount -t bpf bpf %s failed: %s\n", |
| target, strerror(errno)); |
| return -1; |
| } |
| |
| return 0; |
| } |
| |
| static int bpf_mnt_check_target(const char *target) |
| { |
| struct stat sb = {}; |
| int ret; |
| |
| ret = stat(target, &sb); |
| if (ret) { |
| ret = mkdir(target, S_IRWXU); |
| if (ret) { |
| fprintf(stderr, "mkdir %s failed: %s\n", target, |
| strerror(errno)); |
| return ret; |
| } |
| } |
| |
| return 0; |
| } |
| |
| static int bpf_valid_mntpt(const char *mnt, unsigned long magic) |
| { |
| struct statfs st_fs; |
| |
| if (statfs(mnt, &st_fs) < 0) |
| return -ENOENT; |
| if ((unsigned long)st_fs.f_type != magic) |
| return -ENOENT; |
| |
| return 0; |
| } |
| |
| static const char *bpf_find_mntpt_single(unsigned long magic, char *mnt, |
| int len, const char *mntpt) |
| { |
| int ret; |
| |
| ret = bpf_valid_mntpt(mntpt, magic); |
| if (!ret) { |
| strlcpy(mnt, mntpt, len); |
| return mnt; |
| } |
| |
| return NULL; |
| } |
| |
| static const char *bpf_find_mntpt(const char *fstype, unsigned long magic, |
| char *mnt, int len, |
| const char * const *known_mnts) |
| { |
| const char * const *ptr; |
| char type[100]; |
| FILE *fp; |
| |
| if (known_mnts) { |
| ptr = known_mnts; |
| while (*ptr) { |
| if (bpf_find_mntpt_single(magic, mnt, len, *ptr)) |
| return mnt; |
| ptr++; |
| } |
| } |
| |
| if (len != PATH_MAX) |
| return NULL; |
| |
| fp = fopen("/proc/mounts", "r"); |
| if (fp == NULL) |
| return NULL; |
| |
| while (fscanf(fp, "%*s %" textify(PATH_MAX) "s %99s %*s %*d %*d\n", |
| mnt, type) == 2) { |
| if (strcmp(type, fstype) == 0) |
| break; |
| } |
| |
| fclose(fp); |
| if (strcmp(type, fstype) != 0) |
| return NULL; |
| |
| return mnt; |
| } |
| |
| int bpf_trace_pipe(void) |
| { |
| char tracefs_mnt[PATH_MAX] = TRACE_DIR_MNT; |
| static const char * const tracefs_known_mnts[] = { |
| TRACE_DIR_MNT, |
| "/sys/kernel/debug/tracing", |
| "/tracing", |
| "/trace", |
| 0, |
| }; |
| int fd_in, fd_out = STDERR_FILENO; |
| char *tpipe = NULL; |
| const char *mnt; |
| int ret; |
| |
| mnt = bpf_find_mntpt("tracefs", TRACEFS_MAGIC, tracefs_mnt, |
| sizeof(tracefs_mnt), tracefs_known_mnts); |
| if (!mnt) { |
| fprintf(stderr, "tracefs not mounted?\n"); |
| return -1; |
| } |
| |
| ret = asprintf(&tpipe, "%s/trace_pipe", mnt); |
| if (ret < 0) { |
| fprintf(stderr, "asprintf failed: %s\n", strerror(errno)); |
| free(tpipe); |
| return ret; |
| } |
| |
| fd_in = open(tpipe, O_RDONLY); |
| free(tpipe); |
| if (fd_in < 0) |
| return -1; |
| |
| fprintf(stderr, "Running! Hang up with ^C!\n\n"); |
| while (1) { |
| static char buff[4096]; |
| ssize_t ret; |
| |
| ret = read(fd_in, buff, sizeof(buff)); |
| if (ret > 0 && write(fd_out, buff, ret) == ret) |
| continue; |
| break; |
| } |
| |
| close(fd_in); |
| return -1; |
| } |
| |
| static int bpf_gen_global(const char *bpf_sub_dir) |
| { |
| char *bpf_glo_dir = NULL; |
| int ret; |
| |
| ret = asprintf(&bpf_glo_dir, "%s/%s/", bpf_sub_dir, BPF_DIR_GLOBALS); |
| if (ret < 0) { |
| fprintf(stderr, "asprintf failed: %s\n", strerror(errno)); |
| goto out; |
| } |
| |
| ret = mkdir(bpf_glo_dir, S_IRWXU); |
| if (ret && errno != EEXIST) { |
| fprintf(stderr, "mkdir %s failed: %s\n", bpf_glo_dir, |
| strerror(errno)); |
| goto out; |
| } |
| |
| ret = 0; |
| out: |
| free(bpf_glo_dir); |
| return ret; |
| } |
| |
| static int bpf_gen_master(const char *base, const char *name) |
| { |
| char *bpf_sub_dir = NULL; |
| int ret; |
| |
| ret = asprintf(&bpf_sub_dir, "%s%s/", base, name); |
| if (ret < 0) { |
| fprintf(stderr, "asprintf failed: %s\n", strerror(errno)); |
| goto out; |
| } |
| |
| ret = mkdir(bpf_sub_dir, S_IRWXU); |
| if (ret && errno != EEXIST) { |
| fprintf(stderr, "mkdir %s failed: %s\n", bpf_sub_dir, |
| strerror(errno)); |
| goto out; |
| } |
| |
| ret = bpf_gen_global(bpf_sub_dir); |
| out: |
| free(bpf_sub_dir); |
| return ret; |
| } |
| |
| static int bpf_slave_via_bind_mnt(const char *full_name, |
| const char *full_link) |
| { |
| int ret; |
| |
| ret = mkdir(full_name, S_IRWXU); |
| if (ret) { |
| assert(errno != EEXIST); |
| fprintf(stderr, "mkdir %s failed: %s\n", full_name, |
| strerror(errno)); |
| return ret; |
| } |
| |
| ret = mount(full_link, full_name, "none", MS_BIND, NULL); |
| if (ret) { |
| rmdir(full_name); |
| fprintf(stderr, "mount --bind %s %s failed: %s\n", |
| full_link, full_name, strerror(errno)); |
| } |
| |
| return ret; |
| } |
| |
| static int bpf_gen_slave(const char *base, const char *name, |
| const char *link) |
| { |
| char *bpf_lnk_dir = NULL; |
| char *bpf_sub_dir = NULL; |
| struct stat sb = {}; |
| int ret; |
| |
| ret = asprintf(&bpf_lnk_dir, "%s%s/", base, link); |
| if (ret < 0) { |
| fprintf(stderr, "asprintf failed: %s\n", strerror(errno)); |
| goto out; |
| } |
| |
| ret = asprintf(&bpf_sub_dir, "%s%s", base, name); |
| if (ret < 0) { |
| fprintf(stderr, "asprintf failed: %s\n", strerror(errno)); |
| goto out; |
| } |
| |
| ret = symlink(bpf_lnk_dir, bpf_sub_dir); |
| if (ret) { |
| if (errno != EEXIST) { |
| if (errno != EPERM) { |
| fprintf(stderr, "symlink %s failed: %s\n", |
| bpf_sub_dir, strerror(errno)); |
| goto out; |
| } |
| |
| ret = bpf_slave_via_bind_mnt(bpf_sub_dir, bpf_lnk_dir); |
| goto out; |
| } |
| |
| ret = lstat(bpf_sub_dir, &sb); |
| if (ret) { |
| fprintf(stderr, "lstat %s failed: %s\n", |
| bpf_sub_dir, strerror(errno)); |
| goto out; |
| } |
| |
| if ((sb.st_mode & S_IFMT) != S_IFLNK) { |
| ret = bpf_gen_global(bpf_sub_dir); |
| goto out; |
| } |
| } |
| |
| out: |
| free(bpf_lnk_dir); |
| free(bpf_sub_dir); |
| return ret; |
| } |
| |
| static int bpf_gen_hierarchy(const char *base) |
| { |
| int ret, i; |
| |
| ret = bpf_gen_master(base, bpf_prog_to_subdir(__bpf_types[0])); |
| for (i = 1; i < ARRAY_SIZE(__bpf_types) && !ret; i++) |
| ret = bpf_gen_slave(base, |
| bpf_prog_to_subdir(__bpf_types[i]), |
| bpf_prog_to_subdir(__bpf_types[0])); |
| return ret; |
| } |
| |
| static const char *bpf_get_work_dir(enum bpf_prog_type type) |
| { |
| static char bpf_tmp[PATH_MAX] = BPF_DIR_MNT; |
| static char *bpf_wrk_dir; |
| static const char *mnt; |
| static bool bpf_mnt_cached; |
| const char *mnt_env = getenv(BPF_ENV_MNT); |
| static const char * const bpf_known_mnts[] = { |
| BPF_DIR_MNT, |
| "/bpf", |
| 0, |
| }; |
| int ret; |
| |
| if (bpf_mnt_cached) { |
| const char *out = mnt; |
| |
| if (out && type) { |
| snprintf(bpf_tmp, sizeof(bpf_tmp), "%s%s/", |
| out, bpf_prog_to_subdir(type)); |
| out = bpf_tmp; |
| } |
| return out; |
| } |
| |
| if (mnt_env) |
| mnt = bpf_find_mntpt_single(BPF_FS_MAGIC, bpf_tmp, |
| sizeof(bpf_tmp), mnt_env); |
| else |
| mnt = bpf_find_mntpt("bpf", BPF_FS_MAGIC, bpf_tmp, |
| sizeof(bpf_tmp), bpf_known_mnts); |
| if (!mnt) { |
| mnt = mnt_env ? : BPF_DIR_MNT; |
| ret = bpf_mnt_check_target(mnt); |
| if (!ret) |
| ret = bpf_mnt_fs(mnt); |
| if (ret) { |
| mnt = NULL; |
| goto out; |
| } |
| } |
| |
| ret = asprintf(&bpf_wrk_dir, "%s/", mnt); |
| if (ret < 0) { |
| fprintf(stderr, "asprintf failed: %s\n", strerror(errno)); |
| free(bpf_wrk_dir); |
| goto out; |
| } |
| |
| ret = bpf_gen_hierarchy(bpf_wrk_dir); |
| if (ret) { |
| mnt = NULL; |
| goto out; |
| } |
| |
| mnt = bpf_wrk_dir; |
| out: |
| bpf_mnt_cached = true; |
| return mnt; |
| } |
| |
| static int bpf_obj_get(const char *pathname, enum bpf_prog_type type) |
| { |
| union bpf_attr attr = {}; |
| char tmp[PATH_MAX]; |
| |
| if (strlen(pathname) > 2 && pathname[0] == 'm' && |
| pathname[1] == ':' && bpf_get_work_dir(type)) { |
| snprintf(tmp, sizeof(tmp), "%s/%s", |
| bpf_get_work_dir(type), pathname + 2); |
| pathname = tmp; |
| } |
| |
| attr.pathname = bpf_ptr_to_u64(pathname); |
| |
| return bpf(BPF_OBJ_GET, &attr, sizeof(attr)); |
| } |
| |
| static int bpf_obj_pinned(const char *pathname, enum bpf_prog_type type) |
| { |
| int prog_fd = bpf_obj_get(pathname, type); |
| |
| if (prog_fd < 0) |
| fprintf(stderr, "Couldn\'t retrieve pinned program \'%s\': %s\n", |
| pathname, strerror(errno)); |
| return prog_fd; |
| } |
| |
| static int bpf_do_parse(struct bpf_cfg_in *cfg, const bool *opt_tbl) |
| { |
| const char *file, *section, *uds_name; |
| bool verbose = false; |
| int i, ret, argc; |
| char **argv; |
| |
| argv = cfg->argv; |
| argc = cfg->argc; |
| |
| if (opt_tbl[CBPF_BYTECODE] && |
| (matches(*argv, "bytecode") == 0 || |
| strcmp(*argv, "bc") == 0)) { |
| cfg->mode = CBPF_BYTECODE; |
| } else if (opt_tbl[CBPF_FILE] && |
| (matches(*argv, "bytecode-file") == 0 || |
| strcmp(*argv, "bcf") == 0)) { |
| cfg->mode = CBPF_FILE; |
| } else if (opt_tbl[EBPF_OBJECT] && |
| (matches(*argv, "object-file") == 0 || |
| strcmp(*argv, "obj") == 0)) { |
| cfg->mode = EBPF_OBJECT; |
| } else if (opt_tbl[EBPF_PINNED] && |
| (matches(*argv, "object-pinned") == 0 || |
| matches(*argv, "pinned") == 0 || |
| matches(*argv, "fd") == 0)) { |
| cfg->mode = EBPF_PINNED; |
| } else { |
| fprintf(stderr, "What mode is \"%s\"?\n", *argv); |
| return -1; |
| } |
| |
| NEXT_ARG(); |
| file = section = uds_name = NULL; |
| if (cfg->mode == EBPF_OBJECT || cfg->mode == EBPF_PINNED) { |
| file = *argv; |
| NEXT_ARG_FWD(); |
| |
| if (cfg->type == BPF_PROG_TYPE_UNSPEC) { |
| if (argc > 0 && matches(*argv, "type") == 0) { |
| NEXT_ARG(); |
| for (i = 0; i < ARRAY_SIZE(__bpf_prog_meta); |
| i++) { |
| if (!__bpf_prog_meta[i].type) |
| continue; |
| if (!matches(*argv, |
| __bpf_prog_meta[i].type)) { |
| cfg->type = i; |
| break; |
| } |
| } |
| |
| if (cfg->type == BPF_PROG_TYPE_UNSPEC) { |
| fprintf(stderr, "What type is \"%s\"?\n", |
| *argv); |
| return -1; |
| } |
| NEXT_ARG_FWD(); |
| } else { |
| cfg->type = BPF_PROG_TYPE_SCHED_CLS; |
| } |
| } |
| |
| section = bpf_prog_to_default_section(cfg->type); |
| if (argc > 0 && matches(*argv, "section") == 0) { |
| NEXT_ARG(); |
| section = *argv; |
| NEXT_ARG_FWD(); |
| } |
| |
| if (__bpf_prog_meta[cfg->type].may_uds_export) { |
| uds_name = getenv(BPF_ENV_UDS); |
| if (argc > 0 && !uds_name && |
| matches(*argv, "export") == 0) { |
| NEXT_ARG(); |
| uds_name = *argv; |
| NEXT_ARG_FWD(); |
| } |
| } |
| |
| if (argc > 0 && matches(*argv, "verbose") == 0) { |
| verbose = true; |
| NEXT_ARG_FWD(); |
| } |
| |
| PREV_ARG(); |
| } |
| |
| if (cfg->mode == CBPF_BYTECODE || cfg->mode == CBPF_FILE) { |
| ret = bpf_ops_parse(argc, argv, cfg->opcodes, |
| cfg->mode == CBPF_FILE); |
| cfg->n_opcodes = ret; |
| } else if (cfg->mode == EBPF_OBJECT) { |
| ret = 0; /* program will be loaded by load stage */ |
| } else if (cfg->mode == EBPF_PINNED) { |
| ret = bpf_obj_pinned(file, cfg->type); |
| cfg->prog_fd = ret; |
| } else { |
| return -1; |
| } |
| |
| cfg->object = file; |
| cfg->section = section; |
| cfg->uds = uds_name; |
| cfg->argc = argc; |
| cfg->argv = argv; |
| cfg->verbose = verbose; |
| |
| return ret; |
| } |
| |
| static int bpf_do_load(struct bpf_cfg_in *cfg) |
| { |
| if (cfg->mode == EBPF_OBJECT) { |
| cfg->prog_fd = bpf_obj_open(cfg->object, cfg->type, |
| cfg->section, cfg->ifindex, |
| cfg->verbose); |
| return cfg->prog_fd; |
| } |
| return 0; |
| } |
| |
| int bpf_load_common(struct bpf_cfg_in *cfg, const struct bpf_cfg_ops *ops, |
| void *nl) |
| { |
| char annotation[256]; |
| int ret; |
| |
| ret = bpf_do_load(cfg); |
| if (ret < 0) |
| return ret; |
| |
| if (cfg->mode == CBPF_BYTECODE || cfg->mode == CBPF_FILE) |
| ops->cbpf_cb(nl, cfg->opcodes, cfg->n_opcodes); |
| if (cfg->mode == EBPF_OBJECT || cfg->mode == EBPF_PINNED) { |
| snprintf(annotation, sizeof(annotation), "%s:[%s]", |
| basename(cfg->object), cfg->mode == EBPF_PINNED ? |
| "*fsobj" : cfg->section); |
| ops->ebpf_cb(nl, cfg->prog_fd, annotation); |
| } |
| |
| return 0; |
| } |
| |
| int bpf_parse_common(struct bpf_cfg_in *cfg, const struct bpf_cfg_ops *ops) |
| { |
| bool opt_tbl[BPF_MODE_MAX] = {}; |
| |
| if (ops->cbpf_cb) { |
| opt_tbl[CBPF_BYTECODE] = true; |
| opt_tbl[CBPF_FILE] = true; |
| } |
| |
| if (ops->ebpf_cb) { |
| opt_tbl[EBPF_OBJECT] = true; |
| opt_tbl[EBPF_PINNED] = true; |
| } |
| |
| return bpf_do_parse(cfg, opt_tbl); |
| } |
| |
| int bpf_parse_and_load_common(struct bpf_cfg_in *cfg, |
| const struct bpf_cfg_ops *ops, void *nl) |
| { |
| int ret; |
| |
| ret = bpf_parse_common(cfg, ops); |
| if (ret < 0) |
| return ret; |
| |
| return bpf_load_common(cfg, ops, nl); |
| } |
| |
| int bpf_graft_map(const char *map_path, uint32_t *key, int argc, char **argv) |
| { |
| const bool opt_tbl[BPF_MODE_MAX] = { |
| [EBPF_OBJECT] = true, |
| [EBPF_PINNED] = true, |
| }; |
| const struct bpf_elf_map test = { |
| .type = BPF_MAP_TYPE_PROG_ARRAY, |
| .size_key = sizeof(int), |
| .size_value = sizeof(int), |
| }; |
| struct bpf_cfg_in cfg = { |
| .type = BPF_PROG_TYPE_UNSPEC, |
| .argc = argc, |
| .argv = argv, |
| }; |
| struct bpf_map_ext ext = {}; |
| int ret, prog_fd, map_fd; |
| uint32_t map_key; |
| |
| ret = bpf_do_parse(&cfg, opt_tbl); |
| if (ret < 0) |
| return ret; |
| |
| ret = bpf_do_load(&cfg); |
| if (ret < 0) |
| return ret; |
| |
| prog_fd = cfg.prog_fd; |
| |
| if (key) { |
| map_key = *key; |
| } else { |
| ret = sscanf(cfg.section, "%*i/%i", &map_key); |
| if (ret != 1) { |
| fprintf(stderr, "Couldn\'t infer map key from section name! Please provide \'key\' argument!\n"); |
| ret = -EINVAL; |
| goto out_prog; |
| } |
| } |
| |
| map_fd = bpf_obj_get(map_path, cfg.type); |
| if (map_fd < 0) { |
| fprintf(stderr, "Couldn\'t retrieve pinned map \'%s\': %s\n", |
| map_path, strerror(errno)); |
| ret = map_fd; |
| goto out_prog; |
| } |
| |
| ret = bpf_map_selfcheck_pinned(map_fd, &test, &ext, |
| offsetof(struct bpf_elf_map, max_elem), |
| cfg.type); |
| if (ret < 0) { |
| fprintf(stderr, "Map \'%s\' self-check failed!\n", map_path); |
| goto out_map; |
| } |
| |
| ret = bpf_map_update(map_fd, &map_key, &prog_fd, BPF_ANY); |
| if (ret < 0) |
| fprintf(stderr, "Map update failed: %s\n", strerror(errno)); |
| out_map: |
| close(map_fd); |
| out_prog: |
| close(prog_fd); |
| return ret; |
| } |
| |
| int bpf_prog_attach_fd(int prog_fd, int target_fd, enum bpf_attach_type type) |
| { |
| union bpf_attr attr = {}; |
| |
| attr.target_fd = target_fd; |
| attr.attach_bpf_fd = prog_fd; |
| attr.attach_type = type; |
| |
| return bpf(BPF_PROG_ATTACH, &attr, sizeof(attr)); |
| } |
| |
| int bpf_prog_detach_fd(int target_fd, enum bpf_attach_type type) |
| { |
| union bpf_attr attr = {}; |
| |
| attr.target_fd = target_fd; |
| attr.attach_type = type; |
| |
| return bpf(BPF_PROG_DETACH, &attr, sizeof(attr)); |
| } |
| |
| static int bpf_prog_load_dev(enum bpf_prog_type type, |
| const struct bpf_insn *insns, size_t size_insns, |
| const char *license, __u32 ifindex, |
| char *log, size_t size_log) |
| { |
| union bpf_attr attr = {}; |
| |
| attr.prog_type = type; |
| attr.insns = bpf_ptr_to_u64(insns); |
| attr.insn_cnt = size_insns / sizeof(struct bpf_insn); |
| attr.license = bpf_ptr_to_u64(license); |
| attr.prog_ifindex = ifindex; |
| |
| if (size_log > 0) { |
| attr.log_buf = bpf_ptr_to_u64(log); |
| attr.log_size = size_log; |
| attr.log_level = 1; |
| } |
| |
| return bpf(BPF_PROG_LOAD, &attr, sizeof(attr)); |
| } |
| |
| int bpf_prog_load(enum bpf_prog_type type, const struct bpf_insn *insns, |
| size_t size_insns, const char *license, char *log, |
| size_t size_log) |
| { |
| return bpf_prog_load_dev(type, insns, size_insns, license, 0, |
| log, size_log); |
| } |
| |
| #ifdef HAVE_ELF |
| struct bpf_elf_prog { |
| enum bpf_prog_type type; |
| struct bpf_insn *insns; |
| unsigned int insns_num; |
| size_t size; |
| const char *license; |
| }; |
| |
| struct bpf_hash_entry { |
| unsigned int pinning; |
| const char *subpath; |
| struct bpf_hash_entry *next; |
| }; |
| |
| struct bpf_config { |
| unsigned int jit_enabled; |
| }; |
| |
| struct bpf_btf { |
| const struct btf_header *hdr; |
| const void *raw; |
| const char *strings; |
| const struct btf_type **types; |
| int types_num; |
| }; |
| |
| struct bpf_elf_ctx { |
| struct bpf_config cfg; |
| Elf *elf_fd; |
| GElf_Ehdr elf_hdr; |
| Elf_Data *sym_tab; |
| Elf_Data *str_tab; |
| Elf_Data *btf_data; |
| char obj_uid[64]; |
| int obj_fd; |
| int btf_fd; |
| int map_fds[ELF_MAX_MAPS]; |
| struct bpf_elf_map maps[ELF_MAX_MAPS]; |
| struct bpf_map_ext maps_ext[ELF_MAX_MAPS]; |
| struct bpf_elf_prog prog_text; |
| struct bpf_btf btf; |
| int sym_num; |
| int map_num; |
| int map_len; |
| bool *sec_done; |
| int sec_maps; |
| int sec_text; |
| int sec_btf; |
| char license[ELF_MAX_LICENSE_LEN]; |
| enum bpf_prog_type type; |
| __u32 ifindex; |
| bool verbose; |
| bool noafalg; |
| struct bpf_elf_st stat; |
| struct bpf_hash_entry *ht[256]; |
| char *log; |
| size_t log_size; |
| }; |
| |
| struct bpf_elf_sec_data { |
| GElf_Shdr sec_hdr; |
| Elf_Data *sec_data; |
| const char *sec_name; |
| }; |
| |
| struct bpf_map_data { |
| int *fds; |
| const char *obj; |
| struct bpf_elf_st *st; |
| struct bpf_elf_map *ent; |
| }; |
| |
| static bool bpf_log_has_data(struct bpf_elf_ctx *ctx) |
| { |
| return ctx->log && ctx->log[0]; |
| } |
| |
| static __check_format_string(2, 3) void |
| bpf_dump_error(struct bpf_elf_ctx *ctx, const char *format, ...) |
| { |
| va_list vl; |
| |
| va_start(vl, format); |
| vfprintf(stderr, format, vl); |
| va_end(vl); |
| |
| if (bpf_log_has_data(ctx)) { |
| if (ctx->verbose) { |
| fprintf(stderr, "%s\n", ctx->log); |
| } else { |
| unsigned int off = 0, len = strlen(ctx->log); |
| |
| if (len > BPF_MAX_LOG) { |
| off = len - BPF_MAX_LOG; |
| fprintf(stderr, "Skipped %u bytes, use \'verb\' option for the full verbose log.\n[...]\n", |
| off); |
| } |
| fprintf(stderr, "%s\n", ctx->log + off); |
| } |
| |
| memset(ctx->log, 0, ctx->log_size); |
| } |
| } |
| |
| static int bpf_log_realloc(struct bpf_elf_ctx *ctx) |
| { |
| const size_t log_max = UINT_MAX >> 8; |
| size_t log_size = ctx->log_size; |
| char *ptr; |
| |
| if (!ctx->log) { |
| log_size = 65536; |
| } else if (log_size < log_max) { |
| log_size <<= 1; |
| if (log_size > log_max) |
| log_size = log_max; |
| } else { |
| return -EINVAL; |
| } |
| |
| ptr = realloc(ctx->log, log_size); |
| if (!ptr) |
| return -ENOMEM; |
| |
| ptr[0] = 0; |
| ctx->log = ptr; |
| ctx->log_size = log_size; |
| |
| return 0; |
| } |
| |
| static int bpf_map_create(enum bpf_map_type type, uint32_t size_key, |
| uint32_t size_value, uint32_t max_elem, |
| uint32_t flags, int inner_fd, int btf_fd, |
| uint32_t ifindex, uint32_t btf_id_key, |
| uint32_t btf_id_val) |
| { |
| union bpf_attr attr = {}; |
| |
| attr.map_type = type; |
| attr.key_size = size_key; |
| attr.value_size = inner_fd ? sizeof(int) : size_value; |
| attr.max_entries = max_elem; |
| attr.map_flags = flags; |
| attr.inner_map_fd = inner_fd; |
| attr.map_ifindex = ifindex; |
| attr.btf_fd = btf_fd; |
| attr.btf_key_type_id = btf_id_key; |
| attr.btf_value_type_id = btf_id_val; |
| |
| return bpf(BPF_MAP_CREATE, &attr, sizeof(attr)); |
| } |
| |
| static int bpf_btf_load(void *btf, size_t size_btf, |
| char *log, size_t size_log) |
| { |
| union bpf_attr attr = {}; |
| |
| attr.btf = bpf_ptr_to_u64(btf); |
| attr.btf_size = size_btf; |
| |
| if (size_log > 0) { |
| attr.btf_log_buf = bpf_ptr_to_u64(log); |
| attr.btf_log_size = size_log; |
| attr.btf_log_level = 1; |
| } |
| |
| return bpf(BPF_BTF_LOAD, &attr, sizeof(attr)); |
| } |
| |
| static int bpf_obj_pin(int fd, const char *pathname) |
| { |
| union bpf_attr attr = {}; |
| |
| attr.pathname = bpf_ptr_to_u64(pathname); |
| attr.bpf_fd = fd; |
| |
| return bpf(BPF_OBJ_PIN, &attr, sizeof(attr)); |
| } |
| |
| static int bpf_obj_hash(const char *object, uint8_t *out, size_t len) |
| { |
| struct sockaddr_alg alg = { |
| .salg_family = AF_ALG, |
| .salg_type = "hash", |
| .salg_name = "sha1", |
| }; |
| int ret, cfd, ofd, ffd; |
| struct stat stbuff; |
| ssize_t size; |
| |
| if (!object || len != 20) |
| return -EINVAL; |
| |
| cfd = socket(AF_ALG, SOCK_SEQPACKET, 0); |
| if (cfd < 0) |
| return cfd; |
| |
| ret = bind(cfd, (struct sockaddr *)&alg, sizeof(alg)); |
| if (ret < 0) |
| goto out_cfd; |
| |
| ofd = accept(cfd, NULL, 0); |
| if (ofd < 0) { |
| ret = ofd; |
| goto out_cfd; |
| } |
| |
| ffd = open(object, O_RDONLY); |
| if (ffd < 0) { |
| fprintf(stderr, "Error opening object %s: %s\n", |
| object, strerror(errno)); |
| ret = ffd; |
| goto out_ofd; |
| } |
| |
| ret = fstat(ffd, &stbuff); |
| if (ret < 0) { |
| fprintf(stderr, "Error doing fstat: %s\n", |
| strerror(errno)); |
| goto out_ffd; |
| } |
| |
| size = sendfile(ofd, ffd, NULL, stbuff.st_size); |
| if (size != stbuff.st_size) { |
| fprintf(stderr, "Error from sendfile (%zd vs %zu bytes): %s\n", |
| size, stbuff.st_size, strerror(errno)); |
| ret = -1; |
| goto out_ffd; |
| } |
| |
| size = read(ofd, out, len); |
| if (size != len) { |
| fprintf(stderr, "Error from read (%zd vs %zu bytes): %s\n", |
| size, len, strerror(errno)); |
| ret = -1; |
| } else { |
| ret = 0; |
| } |
| out_ffd: |
| close(ffd); |
| out_ofd: |
| close(ofd); |
| out_cfd: |
| close(cfd); |
| return ret; |
| } |
| |
| static void bpf_init_env(void) |
| { |
| struct rlimit limit = { |
| .rlim_cur = RLIM_INFINITY, |
| .rlim_max = RLIM_INFINITY, |
| }; |
| |
| /* Don't bother in case we fail! */ |
| setrlimit(RLIMIT_MEMLOCK, &limit); |
| |
| if (!bpf_get_work_dir(BPF_PROG_TYPE_UNSPEC)) |
| fprintf(stderr, "Continuing without mounted eBPF fs. Too old kernel?\n"); |
| } |
| |
| static const char *bpf_custom_pinning(const struct bpf_elf_ctx *ctx, |
| uint32_t pinning) |
| { |
| struct bpf_hash_entry *entry; |
| |
| entry = ctx->ht[pinning & (ARRAY_SIZE(ctx->ht) - 1)]; |
| while (entry && entry->pinning != pinning) |
| entry = entry->next; |
| |
| return entry ? entry->subpath : NULL; |
| } |
| |
| static bool bpf_no_pinning(const struct bpf_elf_ctx *ctx, |
| uint32_t pinning) |
| { |
| switch (pinning) { |
| case PIN_OBJECT_NS: |
| case PIN_GLOBAL_NS: |
| return false; |
| case PIN_NONE: |
| return true; |
| default: |
| return !bpf_custom_pinning(ctx, pinning); |
| } |
| } |
| |
| static void bpf_make_pathname(char *pathname, size_t len, const char *name, |
| const struct bpf_elf_ctx *ctx, uint32_t pinning) |
| { |
| switch (pinning) { |
| case PIN_OBJECT_NS: |
| snprintf(pathname, len, "%s/%s/%s", |
| bpf_get_work_dir(ctx->type), |
| ctx->obj_uid, name); |
| break; |
| case PIN_GLOBAL_NS: |
| snprintf(pathname, len, "%s/%s/%s", |
| bpf_get_work_dir(ctx->type), |
| BPF_DIR_GLOBALS, name); |
| break; |
| default: |
| snprintf(pathname, len, "%s/../%s/%s", |
| bpf_get_work_dir(ctx->type), |
| bpf_custom_pinning(ctx, pinning), name); |
| break; |
| } |
| } |
| |
| static int bpf_probe_pinned(const char *name, const struct bpf_elf_ctx *ctx, |
| uint32_t pinning) |
| { |
| char pathname[PATH_MAX]; |
| |
| if (bpf_no_pinning(ctx, pinning) || !bpf_get_work_dir(ctx->type)) |
| return 0; |
| |
| bpf_make_pathname(pathname, sizeof(pathname), name, ctx, pinning); |
| return bpf_obj_get(pathname, ctx->type); |
| } |
| |
| static int bpf_make_obj_path(const struct bpf_elf_ctx *ctx) |
| { |
| char *tmp = NULL; |
| int ret; |
| |
| ret = asprintf(&tmp, "%s/%s", bpf_get_work_dir(ctx->type), ctx->obj_uid); |
| if (ret < 0) { |
| fprintf(stderr, "asprintf failed: %s\n", strerror(errno)); |
| goto out; |
| } |
| |
| ret = mkdir(tmp, S_IRWXU); |
| if (ret && errno != EEXIST) { |
| fprintf(stderr, "mkdir %s failed: %s\n", tmp, strerror(errno)); |
| goto out; |
| } |
| |
| ret = 0; |
| out: |
| free(tmp); |
| return ret; |
| } |
| |
| static int bpf_make_custom_path(const struct bpf_elf_ctx *ctx, |
| const char *todo) |
| { |
| char *tmp = NULL; |
| char *rem = NULL; |
| char *sub; |
| int ret; |
| |
| ret = asprintf(&tmp, "%s/../", bpf_get_work_dir(ctx->type)); |
| if (ret < 0) { |
| fprintf(stderr, "asprintf failed: %s\n", strerror(errno)); |
| goto out; |
| } |
| |
| ret = asprintf(&rem, "%s/", todo); |
| if (ret < 0) { |
| fprintf(stderr, "asprintf failed: %s\n", strerror(errno)); |
| goto out; |
| } |
| |
| sub = strtok(rem, "/"); |
| while (sub) { |
| if (strlen(tmp) + strlen(sub) + 2 > PATH_MAX) |
| return -EINVAL; |
| |
| strcat(tmp, sub); |
| strcat(tmp, "/"); |
| |
| ret = mkdir(tmp, S_IRWXU); |
| if (ret && errno != EEXIST) { |
| fprintf(stderr, "mkdir %s failed: %s\n", tmp, |
| strerror(errno)); |
| goto out; |
| } |
| |
| sub = strtok(NULL, "/"); |
| } |
| |
| ret = 0; |
| out: |
| free(rem); |
| free(tmp); |
| return ret; |
| } |
| |
| static int bpf_place_pinned(int fd, const char *name, |
| const struct bpf_elf_ctx *ctx, uint32_t pinning) |
| { |
| char pathname[PATH_MAX]; |
| const char *tmp; |
| int ret = 0; |
| |
| if (bpf_no_pinning(ctx, pinning) || !bpf_get_work_dir(ctx->type)) |
| return 0; |
| |
| 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 ret; |
| |
| bpf_make_pathname(pathname, sizeof(pathname), name, ctx, pinning); |
| return bpf_obj_pin(fd, pathname); |
| } |
| |
| static void bpf_prog_report(int fd, const char *section, |
| const struct bpf_elf_prog *prog, |
| struct bpf_elf_ctx *ctx) |
| { |
| unsigned int insns = prog->size / sizeof(struct bpf_insn); |
| |
| fprintf(stderr, "\nProg section \'%s\' %s%s (%d)!\n", section, |
| fd < 0 ? "rejected: " : "loaded", |
| fd < 0 ? strerror(errno) : "", |
| fd < 0 ? errno : fd); |
| |
| fprintf(stderr, " - Type: %u\n", prog->type); |
| fprintf(stderr, " - Instructions: %u (%u over limit)\n", |
| insns, insns > BPF_MAXINSNS ? insns - BPF_MAXINSNS : 0); |
| fprintf(stderr, " - License: %s\n\n", prog->license); |
| |
| bpf_dump_error(ctx, "Verifier analysis:\n\n"); |
| } |
| |
| static int bpf_prog_attach(const char *section, |
| const struct bpf_elf_prog *prog, |
| struct bpf_elf_ctx *ctx) |
| { |
| int tries = 0, fd; |
| retry: |
| errno = 0; |
| fd = bpf_prog_load_dev(prog->type, prog->insns, prog->size, |
| prog->license, ctx->ifindex, |
| ctx->log, ctx->log_size); |
| if (fd < 0 || ctx->verbose) { |
| /* The verifier log is pretty chatty, sometimes so chatty |
| * on larger programs, that we could fail to dump everything |
| * into our buffer. Still, try to give a debuggable error |
| * log for the user, so enlarge it and re-fail. |
| */ |
| if (fd < 0 && (errno == ENOSPC || !ctx->log_size)) { |
| if (tries++ < 10 && !bpf_log_realloc(ctx)) |
| goto retry; |
| |
| fprintf(stderr, "Log buffer too small to dump verifier log %zu bytes (%d tries)!\n", |
| ctx->log_size, tries); |
| return fd; |
| } |
| |
| bpf_prog_report(fd, section, prog, ctx); |
| } |
| |
| return fd; |
| } |
| |
| static void bpf_map_report(int fd, const char *name, |
| const struct bpf_elf_map *map, |
| struct bpf_elf_ctx *ctx, int inner_fd) |
| { |
| fprintf(stderr, "Map object \'%s\' %s%s (%d)!\n", name, |
| fd < 0 ? "rejected: " : "loaded", |
| fd < 0 ? strerror(errno) : "", |
| fd < 0 ? errno : fd); |
| |
| fprintf(stderr, " - Type: %u\n", map->type); |
| fprintf(stderr, " - Identifier: %u\n", map->id); |
| fprintf(stderr, " - Pinning: %u\n", map->pinning); |
| fprintf(stderr, " - Size key: %u\n", map->size_key); |
| fprintf(stderr, " - Size value: %u\n", |
| inner_fd ? (int)sizeof(int) : map->size_value); |
| fprintf(stderr, " - Max elems: %u\n", map->max_elem); |
| fprintf(stderr, " - Flags: %#x\n\n", map->flags); |
| } |
| |
| static int bpf_find_map_id(const struct bpf_elf_ctx *ctx, uint32_t id) |
| { |
| int i; |
| |
| for (i = 0; i < ctx->map_num; i++) { |
| if (ctx->maps[i].id != id) |
| continue; |
| if (ctx->map_fds[i] < 0) |
| return -EINVAL; |
| |
| return ctx->map_fds[i]; |
| } |
| |
| return -ENOENT; |
| } |
| |
| static void bpf_report_map_in_map(int outer_fd, uint32_t idx) |
| { |
| struct bpf_elf_map outer_map; |
| int ret; |
| |
| fprintf(stderr, "Cannot insert map into map! "); |
| |
| ret = bpf_derive_elf_map_from_fdinfo(outer_fd, &outer_map, NULL); |
| if (!ret) { |
| if (idx >= outer_map.max_elem && |
| outer_map.type == BPF_MAP_TYPE_ARRAY_OF_MAPS) { |
| fprintf(stderr, "Outer map has %u elements, index %u is invalid!\n", |
| outer_map.max_elem, idx); |
| return; |
| } |
| } |
| |
| fprintf(stderr, "Different map specs used for outer and inner map?\n"); |
| } |
| |
| static bool bpf_is_map_in_map_type(const struct bpf_elf_map *map) |
| { |
| return map->type == BPF_MAP_TYPE_ARRAY_OF_MAPS || |
| map->type == BPF_MAP_TYPE_HASH_OF_MAPS; |
| } |
| |
| static bool bpf_map_offload_neutral(enum bpf_map_type type) |
| { |
| return type == BPF_MAP_TYPE_PERF_EVENT_ARRAY; |
| } |
| |
| static int bpf_map_attach(const char *name, struct bpf_elf_ctx *ctx, |
| const struct bpf_elf_map *map, struct bpf_map_ext *ext, |
| int *have_map_in_map) |
| { |
| int fd, ifindex, ret, map_inner_fd = 0; |
| bool retried = false; |
| |
| probe: |
| fd = bpf_probe_pinned(name, ctx, map->pinning); |
| if (fd > 0) { |
| ret = bpf_map_selfcheck_pinned(fd, map, ext, |
| offsetof(struct bpf_elf_map, |
| id), ctx->type); |
| if (ret < 0) { |
| close(fd); |
| fprintf(stderr, "Map \'%s\' self-check failed!\n", |
| name); |
| return ret; |
| } |
| if (ctx->verbose) |
| fprintf(stderr, "Map \'%s\' loaded as pinned!\n", |
| name); |
| return fd; |
| } |
| |
| if (have_map_in_map && bpf_is_map_in_map_type(map)) { |
| (*have_map_in_map)++; |
| if (map->inner_id) |
| return 0; |
| fprintf(stderr, "Map \'%s\' cannot be created since no inner map ID defined!\n", |
| name); |
| return -EINVAL; |
| } |
| |
| if (!have_map_in_map && bpf_is_map_in_map_type(map)) { |
| map_inner_fd = bpf_find_map_id(ctx, map->inner_id); |
| if (map_inner_fd < 0) { |
| fprintf(stderr, "Map \'%s\' cannot be loaded. Inner map with ID %u not found!\n", |
| name, map->inner_id); |
| return -EINVAL; |
| } |
| } |
| |
| ifindex = bpf_map_offload_neutral(map->type) ? 0 : ctx->ifindex; |
| errno = 0; |
| fd = bpf_map_create(map->type, map->size_key, map->size_value, |
| map->max_elem, map->flags, map_inner_fd, ctx->btf_fd, |
| ifindex, ext->btf_id_key, ext->btf_id_val); |
| |
| if (fd < 0 || ctx->verbose) { |
| bpf_map_report(fd, name, map, ctx, map_inner_fd); |
| if (fd < 0) |
| return fd; |
| } |
| |
| ret = bpf_place_pinned(fd, name, ctx, map->pinning); |
| if (ret < 0) { |
| close(fd); |
| if (!retried && errno == EEXIST) { |
| retried = true; |
| goto probe; |
| } |
| fprintf(stderr, "Could not pin %s map: %s\n", name, |
| strerror(errno)); |
| return ret; |
| } |
| |
| return fd; |
| } |
| |
| static const char *bpf_str_tab_name(const struct bpf_elf_ctx *ctx, |
| const GElf_Sym *sym) |
| { |
| return ctx->str_tab->d_buf + sym->st_name; |
| } |
| |
| static int bpf_btf_find(struct bpf_elf_ctx *ctx, const char *name) |
| { |
| const struct btf_type *type; |
| const char *res; |
| int id; |
| |
| for (id = 1; id < ctx->btf.types_num; id++) { |
| type = ctx->btf.types[id]; |
| if (type->name_off >= ctx->btf.hdr->str_len) |
| continue; |
| res = &ctx->btf.strings[type->name_off]; |
| if (!strcmp(res, name)) |
| return id; |
| } |
| |
| return -ENOENT; |
| } |
| |
| static int bpf_btf_find_kv(struct bpf_elf_ctx *ctx, const struct bpf_elf_map *map, |
| const char *name, uint32_t *id_key, uint32_t *id_val) |
| { |
| const struct btf_member *key, *val; |
| const struct btf_type *type; |
| char btf_name[512]; |
| const char *res; |
| int id; |
| |
| snprintf(btf_name, sizeof(btf_name), "____btf_map_%s", name); |
| id = bpf_btf_find(ctx, btf_name); |
| if (id < 0) |
| return id; |
| |
| type = ctx->btf.types[id]; |
| if (BTF_INFO_KIND(type->info) != BTF_KIND_STRUCT) |
| return -EINVAL; |
| if (BTF_INFO_VLEN(type->info) != 2) |
| return -EINVAL; |
| |
| key = ((void *) type) + sizeof(*type); |
| val = key + 1; |
| if (!key->type || key->type >= ctx->btf.types_num || |
| !val->type || val->type >= ctx->btf.types_num) |
| return -EINVAL; |
| |
| if (key->name_off >= ctx->btf.hdr->str_len || |
| val->name_off >= ctx->btf.hdr->str_len) |
| return -EINVAL; |
| |
| res = &ctx->btf.strings[key->name_off]; |
| if (strcmp(res, "key")) |
| return -EINVAL; |
| |
| res = &ctx->btf.strings[val->name_off]; |
| if (strcmp(res, "value")) |
| return -EINVAL; |
| |
| *id_key = key->type; |
| *id_val = val->type; |
| return 0; |
| } |
| |
| static void bpf_btf_annotate(struct bpf_elf_ctx *ctx, int which, const char *name) |
| { |
| uint32_t id_key = 0, id_val = 0; |
| |
| if (!bpf_btf_find_kv(ctx, &ctx->maps[which], name, &id_key, &id_val)) { |
| ctx->maps_ext[which].btf_id_key = id_key; |
| ctx->maps_ext[which].btf_id_val = id_val; |
| } |
| } |
| |
| static const char *bpf_map_fetch_name(struct bpf_elf_ctx *ctx, int which) |
| { |
| const char *name; |
| GElf_Sym sym; |
| int i; |
| |
| for (i = 0; i < ctx->sym_num; i++) { |
| int type; |
| |
| if (gelf_getsym(ctx->sym_tab, i, &sym) != &sym) |
| continue; |
| |
| type = GELF_ST_TYPE(sym.st_info); |
| if (GELF_ST_BIND(sym.st_info) != STB_GLOBAL || |
| (type != STT_NOTYPE && type != STT_OBJECT) || |
| sym.st_shndx != ctx->sec_maps || |
| sym.st_value / ctx->map_len != which) |
| continue; |
| |
| name = bpf_str_tab_name(ctx, &sym); |
| bpf_btf_annotate(ctx, which, name); |
| return name; |
| } |
| |
| return NULL; |
| } |
| |
| static int bpf_maps_attach_all(struct bpf_elf_ctx *ctx) |
| { |
| int i, j, ret, fd, inner_fd, inner_idx, have_map_in_map = 0; |
| const char *map_name; |
| |
| 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 -ENOTSUP; |
| } |
| |
| map_name = bpf_map_fetch_name(ctx, i); |
| if (!map_name) |
| return -EIO; |
| |
| fd = bpf_map_attach(map_name, ctx, &ctx->maps[i], |
| &ctx->maps_ext[i], &have_map_in_map); |
| if (fd < 0) |
| return fd; |
| |
| ctx->map_fds[i] = !fd ? -1 : fd; |
| } |
| |
| for (i = 0; have_map_in_map && i < ctx->map_num; i++) { |
| if (ctx->map_fds[i] >= 0) |
| continue; |
| |
| map_name = bpf_map_fetch_name(ctx, i); |
| if (!map_name) |
| return -EIO; |
| |
| fd = bpf_map_attach(map_name, ctx, &ctx->maps[i], |
| &ctx->maps_ext[i], NULL); |
| if (fd < 0) |
| return fd; |
| |
| ctx->map_fds[i] = fd; |
| } |
| |
| for (i = 0; have_map_in_map && i < ctx->map_num; i++) { |
| if (!ctx->maps[i].id || |
| ctx->maps[i].inner_id || |
| ctx->maps[i].inner_idx == -1) |
| continue; |
| |
| inner_fd = ctx->map_fds[i]; |
| inner_idx = ctx->maps[i].inner_idx; |
| |
| 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; |
| |
| ret = bpf_map_update(ctx->map_fds[j], &inner_idx, |
| &inner_fd, BPF_ANY); |
| if (ret < 0) { |
| bpf_report_map_in_map(ctx->map_fds[j], |
| inner_idx); |
| return ret; |
| } |
| } |
| } |
| |
| return 0; |
| } |
| |
| static int bpf_map_num_sym(struct bpf_elf_ctx *ctx) |
| { |
| int i, num = 0; |
| GElf_Sym sym; |
| |
| for (i = 0; i < ctx->sym_num; i++) { |
| int type; |
| |
| if (gelf_getsym(ctx->sym_tab, i, &sym) != &sym) |
| continue; |
| |
| type = GELF_ST_TYPE(sym.st_info); |
| if (GELF_ST_BIND(sym.st_info) != STB_GLOBAL || |
| (type != STT_NOTYPE && type != STT_OBJECT) || |
| sym.st_shndx != ctx->sec_maps) |
| continue; |
| num++; |
| } |
| |
| return num; |
| } |
| |
| static int bpf_fill_section_data(struct bpf_elf_ctx *ctx, int section, |
| struct bpf_elf_sec_data *data) |
| { |
| Elf_Data *sec_edata; |
| GElf_Shdr sec_hdr; |
| Elf_Scn *sec_fd; |
| char *sec_name; |
| |
| memset(data, 0, sizeof(*data)); |
| |
| sec_fd = elf_getscn(ctx->elf_fd, section); |
| if (!sec_fd) |
| return -EINVAL; |
| if (gelf_getshdr(sec_fd, &sec_hdr) != &sec_hdr) |
| return -EIO; |
| |
| sec_name = elf_strptr(ctx->elf_fd, ctx->elf_hdr.e_shstrndx, |
| sec_hdr.sh_name); |
| if (!sec_name || !sec_hdr.sh_size) |
| return -ENOENT; |
| |
| sec_edata = elf_getdata(sec_fd, NULL); |
| if (!sec_edata || elf_getdata(sec_fd, sec_edata)) |
| return -EIO; |
| |
| memcpy(&data->sec_hdr, &sec_hdr, sizeof(sec_hdr)); |
| |
| data->sec_name = sec_name; |
| data->sec_data = sec_edata; |
| return 0; |
| } |
| |
| struct bpf_elf_map_min { |
| __u32 type; |
| __u32 size_key; |
| __u32 size_value; |
| __u32 max_elem; |
| }; |
| |
| static int bpf_fetch_maps_begin(struct bpf_elf_ctx *ctx, int section, |
| struct bpf_elf_sec_data *data) |
| { |
| ctx->map_num = data->sec_data->d_size; |
| ctx->sec_maps = section; |
| ctx->sec_done[section] = true; |
| |
| if (ctx->map_num > sizeof(ctx->maps)) { |
| fprintf(stderr, "Too many BPF maps in ELF section!\n"); |
| return -ENOMEM; |
| } |
| |
| memcpy(ctx->maps, data->sec_data->d_buf, ctx->map_num); |
| return 0; |
| } |
| |
| static int bpf_map_verify_all_offs(struct bpf_elf_ctx *ctx, int end) |
| { |
| GElf_Sym sym; |
| int off, i; |
| |
| for (off = 0; off < end; off += ctx->map_len) { |
| /* Order doesn't need to be linear here, hence we walk |
| * the table again. |
| */ |
| for (i = 0; i < ctx->sym_num; i++) { |
| int type; |
| |
| if (gelf_getsym(ctx->sym_tab, i, &sym) != &sym) |
| continue; |
| |
| type = GELF_ST_TYPE(sym.st_info); |
| if (GELF_ST_BIND(sym.st_info) != STB_GLOBAL || |
| (type != STT_NOTYPE && type != STT_OBJECT) || |
| sym.st_shndx != ctx->sec_maps) |
| continue; |
| if (sym.st_value == off) |
| break; |
| if (i == ctx->sym_num - 1) |
| return -1; |
| } |
| } |
| |
| return off == end ? 0 : -1; |
| } |
| |
| static int bpf_fetch_maps_end(struct bpf_elf_ctx *ctx) |
| { |
| struct bpf_elf_map fixup[ARRAY_SIZE(ctx->maps)] = {}; |
| int i, sym_num = bpf_map_num_sym(ctx); |
| __u8 *buff; |
| |
| if (sym_num == 0 || sym_num > ARRAY_SIZE(ctx->maps)) { |
| fprintf(stderr, "%u maps not supported in current map section!\n", |
| sym_num); |
| return -EINVAL; |
| } |
| |
| if (ctx->map_num % sym_num != 0 || |
| ctx->map_num % sizeof(__u32) != 0) { |
| fprintf(stderr, "Number BPF map symbols are not multiple of struct bpf_elf_map!\n"); |
| return -EINVAL; |
| } |
| |
| ctx->map_len = ctx->map_num / sym_num; |
| if (bpf_map_verify_all_offs(ctx, ctx->map_num)) { |
| fprintf(stderr, "Different struct bpf_elf_map in use!\n"); |
| return -EINVAL; |
| } |
| |
| if (ctx->map_len == sizeof(struct bpf_elf_map)) { |
| ctx->map_num = sym_num; |
| return 0; |
| } else if (ctx->map_len > sizeof(struct bpf_elf_map)) { |
| fprintf(stderr, "struct bpf_elf_map not supported, coming from future version?\n"); |
| return -EINVAL; |
| } else if (ctx->map_len < sizeof(struct bpf_elf_map_min)) { |
| fprintf(stderr, "struct bpf_elf_map too small, not supported!\n"); |
| return -EINVAL; |
| } |
| |
| ctx->map_num = sym_num; |
| for (i = 0, buff = (void *)ctx->maps; i < ctx->map_num; |
| i++, buff += ctx->map_len) { |
| /* The fixup leaves the rest of the members as zero, which |
| * is fine currently, but option exist to set some other |
| * default value as well when needed in future. |
| */ |
| memcpy(&fixup[i], buff, ctx->map_len); |
| } |
| |
| memcpy(ctx->maps, fixup, sizeof(fixup)); |
| if (ctx->verbose) |
| printf("%zu bytes struct bpf_elf_map fixup performed due to size mismatch!\n", |
| sizeof(struct bpf_elf_map) - ctx->map_len); |
| return 0; |
| } |
| |
| static int bpf_fetch_license(struct bpf_elf_ctx *ctx, int section, |
| struct bpf_elf_sec_data *data) |
| { |
| if (data->sec_data->d_size > sizeof(ctx->license)) |
| return -ENOMEM; |
| |
| memcpy(ctx->license, data->sec_data->d_buf, data->sec_data->d_size); |
| ctx->sec_done[section] = true; |
| return 0; |
| } |
| |
| static int bpf_fetch_symtab(struct bpf_elf_ctx *ctx, int section, |
| struct bpf_elf_sec_data *data) |
| { |
| ctx->sym_tab = data->sec_data; |
| ctx->sym_num = data->sec_hdr.sh_size / data->sec_hdr.sh_entsize; |
| ctx->sec_done[section] = true; |
| return 0; |
| } |
| |
| static int bpf_fetch_strtab(struct bpf_elf_ctx *ctx, int section, |
| struct bpf_elf_sec_data *data) |
| { |
| ctx->str_tab = data->sec_data; |
| ctx->sec_done[section] = true; |
| return 0; |
| } |
| |
| static int bpf_fetch_text(struct bpf_elf_ctx *ctx, int section, |
| struct bpf_elf_sec_data *data) |
| { |
| ctx->sec_text = section; |
| ctx->sec_done[section] = true; |
| return 0; |
| } |
| |
| static void bpf_btf_report(int fd, struct bpf_elf_ctx *ctx) |
| { |
| fprintf(stderr, "\nBTF debug data section \'.BTF\' %s%s (%d)!\n", |
| fd < 0 ? "rejected: " : "loaded", |
| fd < 0 ? strerror(errno) : "", |
| fd < 0 ? errno : fd); |
| |
| fprintf(stderr, " - Length: %zu\n", ctx->btf_data->d_size); |
| |
| bpf_dump_error(ctx, "Verifier analysis:\n\n"); |
| } |
| |
| static int bpf_btf_attach(struct bpf_elf_ctx *ctx) |
| { |
| int tries = 0, fd; |
| retry: |
| errno = 0; |
| fd = bpf_btf_load(ctx->btf_data->d_buf, ctx->btf_data->d_size, |
| ctx->log, ctx->log_size); |
| if (fd < 0 || ctx->verbose) { |
| if (fd < 0 && (errno == ENOSPC || !ctx->log_size)) { |
| if (tries++ < 10 && !bpf_log_realloc(ctx)) |
| goto retry; |
| |
| fprintf(stderr, "Log buffer too small to dump verifier log %zu bytes (%d tries)!\n", |
| ctx->log_size, tries); |
| return fd; |
| } |
| |
| if (bpf_log_has_data(ctx)) |
| bpf_btf_report(fd, ctx); |
| } |
| |
| return fd; |
| } |
| |
| static int bpf_fetch_btf_begin(struct bpf_elf_ctx *ctx, int section, |
| struct bpf_elf_sec_data *data) |
| { |
| ctx->btf_data = data->sec_data; |
| ctx->sec_btf = section; |
| ctx->sec_done[section] = true; |
| return 0; |
| } |
| |
| static int bpf_btf_check_header(struct bpf_elf_ctx *ctx) |
| { |
| const struct btf_header *hdr = ctx->btf_data->d_buf; |
| const char *str_start, *str_end; |
| unsigned int data_len; |
| |
| if (hdr->magic != BTF_MAGIC) { |
| fprintf(stderr, "Object has wrong BTF magic: %x, expected: %x!\n", |
| hdr->magic, BTF_MAGIC); |
| return -EINVAL; |
| } |
| |
| if (hdr->version != BTF_VERSION) { |
| fprintf(stderr, "Object has wrong BTF version: %u, expected: %u!\n", |
| hdr->version, BTF_VERSION); |
| return -EINVAL; |
| } |
| |
| if (hdr->flags) { |
| fprintf(stderr, "Object has unsupported BTF flags %x!\n", |
| hdr->flags); |
| return -EINVAL; |
| } |
| |
| data_len = ctx->btf_data->d_size - sizeof(*hdr); |
| if (data_len < hdr->type_off || |
| data_len < hdr->str_off || |
| data_len < hdr->type_len + hdr->str_len || |
| hdr->type_off >= hdr->str_off || |
| hdr->type_off + hdr->type_len != hdr->str_off || |
| hdr->str_off + hdr->str_len != data_len || |
| (hdr->type_off & (sizeof(uint32_t) - 1))) { |
| fprintf(stderr, "Object has malformed BTF data!\n"); |
| return -EINVAL; |
| } |
| |
| ctx->btf.hdr = hdr; |
| ctx->btf.raw = hdr + 1; |
| |
| str_start = ctx->btf.raw + hdr->str_off; |
| str_end = str_start + hdr->str_len; |
| if (!hdr->str_len || |
| hdr->str_len - 1 > BTF_MAX_NAME_OFFSET || |
| str_start[0] || str_end[-1]) { |
| fprintf(stderr, "Object has malformed BTF string data!\n"); |
| return -EINVAL; |
| } |
| |
| ctx->btf.strings = str_start; |
| return 0; |
| } |
| |
| static int bpf_btf_register_type(struct bpf_elf_ctx *ctx, |
| const struct btf_type *type) |
| { |
| int cur = ctx->btf.types_num, num = cur + 1; |
| const struct btf_type **types; |
| |
| types = realloc(ctx->btf.types, num * sizeof(type)); |
| if (!types) { |
| free(ctx->btf.types); |
| ctx->btf.types = NULL; |
| ctx->btf.types_num = 0; |
| return -ENOMEM; |
| } |
| |
| ctx->btf.types = types; |
| ctx->btf.types[cur] = type; |
| ctx->btf.types_num = num; |
| return 0; |
| } |
| |
| static struct btf_type btf_type_void; |
| |
| static int bpf_btf_prep_type_data(struct bpf_elf_ctx *ctx) |
| { |
| const void *type_cur = ctx->btf.raw + ctx->btf.hdr->type_off; |
| const void *type_end = ctx->btf.raw + ctx->btf.hdr->str_off; |
| const struct btf_type *type; |
| uint16_t var_len; |
| int ret, kind; |
| |
| ret = bpf_btf_register_type(ctx, &btf_type_void); |
| if (ret < 0) |
| return ret; |
| |
| while (type_cur < type_end) { |
| type = type_cur; |
| type_cur += sizeof(*type); |
| |
| var_len = BTF_INFO_VLEN(type->info); |
| kind = BTF_INFO_KIND(type->info); |
| |
| switch (kind) { |
| case BTF_KIND_INT: |
| type_cur += sizeof(int); |
| break; |
| case BTF_KIND_ARRAY: |
| type_cur += sizeof(struct btf_array); |
| break; |
| case BTF_KIND_STRUCT: |
| case BTF_KIND_UNION: |
| type_cur += var_len * sizeof(struct btf_member); |
| break; |
| case BTF_KIND_ENUM: |
| type_cur += var_len * sizeof(struct btf_enum); |
| break; |
| case BTF_KIND_FUNC_PROTO: |
| type_cur += var_len * sizeof(struct btf_param); |
| break; |
| case BTF_KIND_TYPEDEF: |
| case BTF_KIND_PTR: |
| case BTF_KIND_FWD: |
| case BTF_KIND_VOLATILE: |
| case BTF_KIND_CONST: |
| case BTF_KIND_RESTRICT: |
| case BTF_KIND_FUNC: |
| break; |
| default: |
| fprintf(stderr, "Object has unknown BTF type: %u!\n", kind); |
| return -EINVAL; |
| } |
| |
| ret = bpf_btf_register_type(ctx, type); |
| if (ret < 0) |
| return ret; |
| } |
| |
| return 0; |
| } |
| |
| static int bpf_btf_prep_data(struct bpf_elf_ctx *ctx) |
| { |
| int ret = bpf_btf_check_header(ctx); |
| |
| if (!ret) |
| return bpf_btf_prep_type_data(ctx); |
| return ret; |
| } |
| |
| static void bpf_fetch_btf_end(struct bpf_elf_ctx *ctx) |
| { |
| int fd = bpf_btf_attach(ctx); |
| |
| if (fd < 0) |
| return; |
| ctx->btf_fd = fd; |
| if (bpf_btf_prep_data(ctx) < 0) { |
| close(ctx->btf_fd); |
| ctx->btf_fd = 0; |
| } |
| } |
| |
| static bool bpf_has_map_data(const struct bpf_elf_ctx *ctx) |
| { |
| return ctx->sym_tab && ctx->str_tab && ctx->sec_maps; |
| } |
| |
| static bool bpf_has_btf_data(const struct bpf_elf_ctx *ctx) |
| { |
| return ctx->sec_btf; |
| } |
| |
| static bool bpf_has_call_data(const struct bpf_elf_ctx *ctx) |
| { |
| return ctx->sec_text; |
| } |
| |
| static int bpf_fetch_ancillary(struct bpf_elf_ctx *ctx, bool check_text_sec) |
| { |
| struct bpf_elf_sec_data data; |
| int i, ret = -1; |
| |
| 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_PROGBITS && |
| !strcmp(data.sec_name, ELF_SECTION_LICENSE)) |
| ret = bpf_fetch_license(ctx, i, &data); |
| else if (data.sec_hdr.sh_type == SHT_PROGBITS && |
| (data.sec_hdr.sh_flags & SHF_EXECINSTR) && |
| !strcmp(data.sec_name, ".text") && |
| check_text_sec) |
| ret = bpf_fetch_text(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); |
| else if (data.sec_hdr.sh_type == SHT_PROGBITS && |
| !strcmp(data.sec_name, ".BTF")) |
| ret = bpf_fetch_btf_begin(ctx, i, &data); |
| if (ret < 0) { |
| fprintf(stderr, "Error parsing section %d! Perhaps check with readelf -a?\n", |
| i); |
| return ret; |
| } |
| } |
| |
| if (bpf_has_btf_data(ctx)) |
| bpf_fetch_btf_end(ctx); |
| 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; |
| } |
| |
| ret = bpf_maps_attach_all(ctx); |
| if (ret < 0) { |
| fprintf(stderr, "Error loading maps into kernel!\n"); |
| return ret; |
| } |
| } |
| |
| return ret; |
| } |
| |
| static int bpf_fetch_prog(struct bpf_elf_ctx *ctx, const char *section, |
| bool *sseen) |
| { |
| struct bpf_elf_sec_data data; |
| struct bpf_elf_prog prog; |
| int ret, i, fd = -1; |
| |
| for (i = 1; i < ctx->elf_hdr.e_shnum; i++) { |
| if (ctx->sec_done[i]) |
| continue; |
| |
| ret = bpf_fill_section_data(ctx, i, &data); |
| if (ret < 0 || |
| !(data.sec_hdr.sh_type == SHT_PROGBITS && |
| (data.sec_hdr.sh_flags & SHF_EXECINSTR) && |
| !strcmp(data.sec_name, section))) |
| continue; |
| |
| *sseen = true; |
| |
| memset(&prog, 0, sizeof(prog)); |
| prog.type = ctx->type; |
| prog.license = ctx->license; |
| prog.size = data.sec_data->d_size; |
| prog.insns_num = prog.size / sizeof(struct bpf_insn); |
| prog.insns = data.sec_data->d_buf; |
| |
| fd = bpf_prog_attach(section, &prog, ctx); |
| if (fd < 0) |
| return fd; |
| |
| ctx->sec_done[i] = true; |
| break; |
| } |
| |
| return fd; |
| } |
| |
| struct bpf_relo_props { |
| struct bpf_tail_call { |
| unsigned int total; |
| unsigned int jited; |
| } tc; |
| int main_num; |
| }; |
| |
| static int bpf_apply_relo_map(struct bpf_elf_ctx *ctx, struct bpf_elf_prog *prog, |
| GElf_Rel *relo, GElf_Sym *sym, |
| struct bpf_relo_props *props) |
| { |
| unsigned int insn_off = relo->r_offset / sizeof(struct bpf_insn); |
| unsigned int map_idx = sym->st_value / ctx->map_len; |
| |
| if (insn_off >= prog->insns_num) |
| return -EINVAL; |
| if (prog->insns[insn_off].code != (BPF_LD | BPF_IMM | BPF_DW)) { |
| fprintf(stderr, "ELF contains relo data for non ld64 instruction at offset %u! Compiler bug?!\n", |
| insn_off); |
| return -EINVAL; |
| } |
| |
| if (map_idx >= ARRAY_SIZE(ctx->map_fds)) |
| return -EINVAL; |
| if (!ctx->map_fds[map_idx]) |
| return -EINVAL; |
| if (ctx->maps[map_idx].type == BPF_MAP_TYPE_PROG_ARRAY) { |
| props->tc.total++; |
| if (ctx->maps_ext[map_idx].owner.jited || |
| (ctx->maps_ext[map_idx].owner.type == 0 && |
| ctx->cfg.jit_enabled)) |
| props->tc.jited++; |
| } |
| |
| prog->insns[insn_off].src_reg = BPF_PSEUDO_MAP_FD; |
| prog->insns[insn_off].imm = ctx->map_fds[map_idx]; |
| return 0; |
| } |
| |
| static int bpf_apply_relo_call(struct bpf_elf_ctx *ctx, struct bpf_elf_prog *prog, |
| GElf_Rel *relo, GElf_Sym *sym, |
| struct bpf_relo_props *props) |
| { |
| unsigned int insn_off = relo->r_offset / sizeof(struct bpf_insn); |
| struct bpf_elf_prog *prog_text = &ctx->prog_text; |
| |
| if (insn_off >= prog->insns_num) |
| return -EINVAL; |
| if (prog->insns[insn_off].code != (BPF_JMP | BPF_CALL) && |
| prog->insns[insn_off].src_reg != BPF_PSEUDO_CALL) { |
| fprintf(stderr, "ELF contains relo data for non call instruction at offset %u! Compiler bug?!\n", |
| insn_off); |
| return -EINVAL; |
| } |
| |
| if (!props->main_num) { |
| struct bpf_insn *insns = realloc(prog->insns, |
| prog->size + prog_text->size); |
| if (!insns) |
| return -ENOMEM; |
| |
| memcpy(insns + prog->insns_num, prog_text->insns, |
| prog_text->size); |
| props->main_num = prog->insns_num; |
| prog->insns = insns; |
| prog->insns_num += prog_text->insns_num; |
| prog->size += prog_text->size; |
| } |
| |
| prog->insns[insn_off].imm += props->main_num - insn_off; |
| return 0; |
| } |
| |
| static int bpf_apply_relo_data(struct bpf_elf_ctx *ctx, |
| struct bpf_elf_sec_data *data_relo, |
| struct bpf_elf_prog *prog, |
| struct bpf_relo_props *props) |
| { |
| GElf_Shdr *rhdr = &data_relo->sec_hdr; |
| int relo_ent, relo_num = rhdr->sh_size / rhdr->sh_entsize; |
| |
| for (relo_ent = 0; relo_ent < relo_num; relo_ent++) { |
| GElf_Rel relo; |
| GElf_Sym sym; |
| int ret = -EIO; |
| |
| if (gelf_getrel(data_relo->sec_data, relo_ent, &relo) != &relo) |
| return -EIO; |
| if (gelf_getsym(ctx->sym_tab, GELF_R_SYM(relo.r_info), &sym) != &sym) |
| return -EIO; |
| |
| if (sym.st_shndx == ctx->sec_maps) |
| ret = bpf_apply_relo_map(ctx, prog, &relo, &sym, props); |
| else if (sym.st_shndx == ctx->sec_text) |
| ret = bpf_apply_relo_call(ctx, prog, &relo, &sym, props); |
| else |
| fprintf(stderr, "ELF contains non-{map,call} related relo data in entry %u pointing to section %u! Compiler bug?!\n", |
| relo_ent, sym.st_shndx); |
| if (ret < 0) |
| return ret; |
| } |
| |
| return 0; |
| } |
| |
| static int bpf_fetch_prog_relo(struct bpf_elf_ctx *ctx, const char *section, |
| bool *lderr, bool *sseen, struct bpf_elf_prog *prog) |
| { |
| struct bpf_elf_sec_data data_relo, data_insn; |
| int ret, idx, i, fd = -1; |
| |
| for (i = 1; i < ctx->elf_hdr.e_shnum; i++) { |
| struct bpf_relo_props props = {}; |
| |
| ret = bpf_fill_section_data(ctx, i, &data_relo); |
| if (ret < 0 || data_relo.sec_hdr.sh_type != SHT_REL) |
| continue; |
| |
| idx = data_relo.sec_hdr.sh_info; |
| |
| ret = bpf_fill_section_data(ctx, idx, &data_insn); |
| if (ret < 0 || |
| !(data_insn.sec_hdr.sh_type == SHT_PROGBITS && |
| (data_insn.sec_hdr.sh_flags & SHF_EXECINSTR) && |
| !strcmp(data_insn.sec_name, section))) |
| continue; |
| if (sseen) |
| *sseen = true; |
| |
| memset(prog, 0, sizeof(*prog)); |
| prog->type = ctx->type; |
| prog->license = ctx->license; |
| prog->size = data_insn.sec_data->d_size; |
| prog->insns_num = prog->size / sizeof(struct bpf_insn); |
| prog->insns = malloc(prog->size); |
| if (!prog->insns) { |
| *lderr = true; |
| return -ENOMEM; |
| } |
| |
| memcpy(prog->insns, data_insn.sec_data->d_buf, prog->size); |
| |
| ret = bpf_apply_relo_data(ctx, &data_relo, prog, &props); |
| if (ret < 0) { |
| *lderr = true; |
| if (ctx->sec_text != idx) |
| free(prog->insns); |
| return ret; |
| } |
| if (ctx->sec_text == idx) { |
| fd = 0; |
| goto out; |
| } |
| |
| fd = bpf_prog_attach(section, prog, ctx); |
| free(prog->insns); |
| if (fd < 0) { |
| *lderr = true; |
| if (props.tc.total) { |
| if (ctx->cfg.jit_enabled && |
| props.tc.total != props.tc.jited) |
| fprintf(stderr, "JIT enabled, but only %u/%u tail call maps in the program have JITed owner!\n", |
| props.tc.jited, props.tc.total); |
| if (!ctx->cfg.jit_enabled && |
| props.tc.jited) |
| fprintf(stderr, "JIT disabled, but %u/%u tail call maps in the program have JITed owner!\n", |
| props.tc.jited, props.tc.total); |
| } |
| return fd; |
| } |
| out: |
| ctx->sec_done[i] = true; |
| ctx->sec_done[idx] = true; |
| break; |
| } |
| |
| return fd; |
| } |
| |
| static int bpf_fetch_prog_sec(struct bpf_elf_ctx *ctx, const char *section) |
| { |
| bool lderr = false, sseen = false; |
| struct bpf_elf_prog prog; |
| int ret = -1; |
| |
| if (bpf_has_call_data(ctx)) { |
| ret = bpf_fetch_prog_relo(ctx, ".text", &lderr, NULL, |
| &ctx->prog_text); |
| if (ret < 0) |
| return ret; |
| } |
| |
| if (bpf_has_map_data(ctx) || bpf_has_call_data(ctx)) |
| ret = bpf_fetch_prog_relo(ctx, section, &lderr, &sseen, &prog); |
| if (ret < 0 && !lderr) |
| ret = bpf_fetch_prog(ctx, section, &sseen); |
| if (ret < 0 && !sseen) |
| fprintf(stderr, "Program section \'%s\' not found in ELF file!\n", |
| section); |
| return ret; |
| } |
| |
| static int bpf_find_map_by_id(struct bpf_elf_ctx *ctx, uint32_t id) |
| { |
| int i; |
| |
| for (i = 0; i < ARRAY_SIZE(ctx->map_fds); i++) |
| if (ctx->map_fds[i] && ctx->maps[i].id == id && |
| ctx->maps[i].type == BPF_MAP_TYPE_PROG_ARRAY) |
| return i; |
| return -1; |
| } |
| |
| struct bpf_jited_aux { |
| int prog_fd; |
| int map_fd; |
| struct bpf_prog_data prog; |
| struct bpf_map_ext map; |
| }; |
| |
| static int bpf_derive_prog_from_fdinfo(int fd, struct bpf_prog_data *prog) |
| { |
| char *file = NULL; |
| char buff[4096]; |
| unsigned int val; |
| FILE *fp; |
| int ret; |
| |
| ret = asprintf(&file, "/proc/%d/fdinfo/%d", getpid(), fd); |
| if (ret < 0) { |
| fprintf(stderr, "asprintf failed: %s\n", strerror(errno)); |
| free(file); |
| return ret; |
| } |
| |
| memset(prog, 0, sizeof(*prog)); |
| |
| fp = fopen(file, "r"); |
| free(file); |
| if (!fp) { |
| fprintf(stderr, "No procfs support?!\n"); |
| return -EIO; |
| } |
| |
| while (fgets(buff, sizeof(buff), fp)) { |
| if (sscanf(buff, "prog_type:\t%u", &val) == 1) |
| prog->type = val; |
| else if (sscanf(buff, "prog_jited:\t%u", &val) == 1) |
| prog->jited = val; |
| } |
| |
| fclose(fp); |
| return 0; |
| } |
| |
| static int bpf_tail_call_get_aux(struct bpf_jited_aux *aux) |
| { |
| struct bpf_elf_map tmp; |
| int ret; |
| |
| ret = bpf_derive_elf_map_from_fdinfo(aux->map_fd, &tmp, &aux->map); |
| if (!ret) |
| ret = bpf_derive_prog_from_fdinfo(aux->prog_fd, &aux->prog); |
| |
| return ret; |
| } |
| |
| static int bpf_fill_prog_arrays(struct bpf_elf_ctx *ctx) |
| { |
| struct bpf_elf_sec_data data; |
| uint32_t map_id, key_id; |
| int fd, i, ret, idx; |
| |
| for (i = 1; i < ctx->elf_hdr.e_shnum; i++) { |
| if (ctx->sec_done[i]) |
| continue; |
| |
| ret = bpf_fill_section_data(ctx, i, &data); |
| if (ret < 0) |
| continue; |
| |
| ret = sscanf(data.sec_name, "%i/%i", &map_id, &key_id); |
| if (ret != 2) |
| continue; |
| |
| idx = bpf_find_map_by_id(ctx, map_id); |
| if (idx < 0) |
| continue; |
| |
| fd = bpf_fetch_prog_sec(ctx, data.sec_name); |
| if (fd < 0) |
| return -EIO; |
| |
| ret = bpf_map_update(ctx->map_fds[idx], &key_id, |
| &fd, BPF_ANY); |
| if (ret < 0) { |
| struct bpf_jited_aux aux = {}; |
| |
| ret = -errno; |
| if (errno == E2BIG) { |
| fprintf(stderr, "Tail call key %u for map %u out of bounds?\n", |
| key_id, map_id); |
| return ret; |
| } |
| |
| aux.map_fd = ctx->map_fds[idx]; |
| aux.prog_fd = fd; |
| |
| if (bpf_tail_call_get_aux(&aux)) |
| return ret; |
| if (!aux.map.owner.type) |
| return ret; |
| |
| if (aux.prog.type != aux.map.owner.type) |
| fprintf(stderr, "Tail call map owned by prog type %u, but prog type is %u!\n", |
| aux.map.owner.type, aux.prog.type); |
| if (aux.prog.jited != aux.map.owner.jited) |
| fprintf(stderr, "Tail call map %s jited, but prog %s!\n", |
| aux.map.owner.jited ? "is" : "not", |
| aux.prog.jited ? "is" : "not"); |
| return ret; |
| } |
| |
| ctx->sec_done[i] = true; |
| } |
| |
| return 0; |
| } |
| |
| static void bpf_save_finfo(struct bpf_elf_ctx *ctx) |
| { |
| struct stat st; |
| int ret; |
| |
| memset(&ctx->stat, 0, sizeof(ctx->stat)); |
| |
| ret = fstat(ctx->obj_fd, &st); |
| if (ret < 0) { |
| fprintf(stderr, "Stat of elf file failed: %s\n", |
| strerror(errno)); |
| return; |
| } |
| |
| ctx->stat.st_dev = st.st_dev; |
| ctx->stat.st_ino = st.st_ino; |
| } |
| |
| static int bpf_read_pin_mapping(FILE *fp, uint32_t *id, char *path) |
| { |
| char buff[PATH_MAX]; |
| |
| while (fgets(buff, sizeof(buff), fp)) { |
| char *ptr = buff; |
| |
| while (*ptr == ' ' || *ptr == '\t') |
| ptr++; |
| |
| if (*ptr == '#' || *ptr == '\n' || *ptr == 0) |
| continue; |
| |
| if (sscanf(ptr, "%i %s\n", id, path) != 2 && |
| sscanf(ptr, "%i %s #", id, path) != 2) { |
| strcpy(path, ptr); |
| return -1; |
| } |
| |
| return 1; |
| } |
| |
| return 0; |
| } |
| |
| static bool bpf_pinning_reserved(uint32_t pinning) |
| { |
| switch (pinning) { |
| case PIN_NONE: |
| case PIN_OBJECT_NS: |
| case PIN_GLOBAL_NS: |
| return true; |
| default: |
| return false; |
| } |
| } |
| |
| static void bpf_hash_init(struct bpf_elf_ctx *ctx, const char *db_file) |
| { |
| struct bpf_hash_entry *entry; |
| char subpath[PATH_MAX] = {}; |
| uint32_t pinning; |
| FILE *fp; |
| int ret; |
| |
| fp = fopen(db_file, "r"); |
| if (!fp) |
| return; |
| |
| while ((ret = bpf_read_pin_mapping(fp, &pinning, subpath))) { |
| if (ret == -1) { |
| fprintf(stderr, "Database %s is corrupted at: %s\n", |
| db_file, subpath); |
| fclose(fp); |
| return; |
| } |
| |
| if (bpf_pinning_reserved(pinning)) { |
| fprintf(stderr, "Database %s, id %u is reserved - ignoring!\n", |
| db_file, pinning); |
| continue; |
| } |
| |
| entry = malloc(sizeof(*entry)); |
| if (!entry) { |
| fprintf(stderr, "No memory left for db entry!\n"); |
| continue; |
| } |
| |
| entry->pinning = pinning; |
| entry->subpath = strdup(subpath); |
| if (!entry->subpath) { |
| fprintf(stderr, "No memory left for db entry!\n"); |
| free(entry); |
| continue; |
| } |
| |
| entry->next = ctx->ht[pinning & (ARRAY_SIZE(ctx->ht) - 1)]; |
| ctx->ht[pinning & (ARRAY_SIZE(ctx->ht) - 1)] = entry; |
| } |
| |
| fclose(fp); |
| } |
| |
| static void bpf_hash_destroy(struct bpf_elf_ctx *ctx) |
| { |
| struct bpf_hash_entry *entry; |
| int i; |
| |
| for (i = 0; i < ARRAY_SIZE(ctx->ht); i++) { |
| while ((entry = ctx->ht[i]) != NULL) { |
| ctx->ht[i] = entry->next; |
| free((char *)entry->subpath); |
| free(entry); |
| } |
| } |
| } |
| |
|