| /* |
| * 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 "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, |
| }; |
| |
| 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, |
| }, |
| }; |
| |
| 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, bool verbose); |
| #else |
| static int bpf_obj_open(const char *path, enum bpf_prog_type type, |
| const char *sec, 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_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, *last; |
| FILE *fp; |
| |
| tmp_len = sizeof("4096,") + BPF_MAXINSNS * op_len; |
| tmp_string = 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; |
| } |
| |
| if (!fgets(tmp_string, tmp_len, fp)) { |
| free(tmp_string); |
| fclose(fp); |
| return -EIO; |
| } |
| |
| fclose(fp); |
| |
| last = &tmp_string[strlen(tmp_string) - 1]; |
| if (*last == '\n') |
| *last = 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(FILE *f, struct rtattr *bpf_ops, __u16 len) |
| { |
| struct sock_filter *ops = (struct sock_filter *) RTA_DATA(bpf_ops); |
| int i; |
| |
| if (len == 0) |
| return; |
| |
| fprintf(f, "bytecode \'%u,", len); |
| |
| for (i = 0; i < len - 1; i++) |
| fprintf(f, "%hu %hhu %hhu %u,", ops[i].code, ops[i].jt, |
| ops[i].jf, ops[i].k); |
| |
| fprintf(f, "%hu %hhu %hhu %u\'", ops[i].code, ops[i].jt, |
| ops[i].jf, ops[i].k); |
| } |
| |
| 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"); |
| } |
| |
| static int bpf_map_selfcheck_pinned(int fd, const struct bpf_elf_map *map, |
| int length) |
| { |
| char file[PATH_MAX], buff[4096]; |
| struct bpf_elf_map tmp = {}, zero = {}; |
| unsigned int val; |
| FILE *fp; |
| |
| snprintf(file, sizeof(file), "/proc/%d/fdinfo/%d", getpid(), fd); |
| |
| fp = fopen(file, "r"); |
| 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) |
| tmp.type = val; |
| else if (sscanf(buff, "key_size:\t%u", &val) == 1) |
| tmp.size_key = val; |
| else if (sscanf(buff, "value_size:\t%u", &val) == 1) |
| tmp.size_value = val; |
| else if (sscanf(buff, "max_entries:\t%u", &val) == 1) |
| tmp.max_elem = val; |
| else if (sscanf(buff, "map_flags:\t%i", &val) == 1) |
| tmp.flags = val; |
| } |
| |
| fclose(fp); |
| |
| 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_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(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_valid_mntpt(*ptr, magic) == 0) { |
| strncpy(mnt, *ptr, len - 1); |
| mnt[len - 1] = 0; |
| return mnt; |
| } |
| ptr++; |
| } |
| } |
| |
| fp = fopen("/proc/mounts", "r"); |
| if (fp == NULL || len != PATH_MAX) |
| 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, |
| }; |
| char tpipe[PATH_MAX]; |
| const char *mnt; |
| int fd; |
| |
| 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; |
| } |
| |
| snprintf(tpipe, sizeof(tpipe), "%s/trace_pipe", mnt); |
| |
| fd = open(tpipe, O_RDONLY); |
| if (fd < 0) |
| return -1; |
| |
| fprintf(stderr, "Running! Hang up with ^C!\n\n"); |
| while (1) { |
| static char buff[4096]; |
| ssize_t ret; |
| |
| ret = read(fd, buff, sizeof(buff) - 1); |
| if (ret > 0) { |
| write(2, buff, ret); |
| fflush(stderr); |
| } |
| } |
| |
| return 0; |
| } |
| |
| static int bpf_gen_global(const char *bpf_sub_dir) |
| { |
| char bpf_glo_dir[PATH_MAX]; |
| int ret; |
| |
| snprintf(bpf_glo_dir, sizeof(bpf_glo_dir), "%s/%s/", |
| bpf_sub_dir, BPF_DIR_GLOBALS); |
| |
| ret = mkdir(bpf_glo_dir, S_IRWXU); |
| if (ret && errno != EEXIST) { |
| fprintf(stderr, "mkdir %s failed: %s\n", bpf_glo_dir, |
| strerror(errno)); |
| return ret; |
| } |
| |
| return 0; |
| } |
| |
| static int bpf_gen_master(const char *base, const char *name) |
| { |
| char bpf_sub_dir[PATH_MAX]; |
| int ret; |
| |
| snprintf(bpf_sub_dir, sizeof(bpf_sub_dir), "%s%s/", base, name); |
| |
| ret = mkdir(bpf_sub_dir, S_IRWXU); |
| if (ret && errno != EEXIST) { |
| fprintf(stderr, "mkdir %s failed: %s\n", bpf_sub_dir, |
| strerror(errno)); |
| return ret; |
| } |
| |
| return bpf_gen_global(bpf_sub_dir); |
| } |
| |
| 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[PATH_MAX]; |
| char bpf_sub_dir[PATH_MAX]; |
| struct stat sb = {}; |
| int ret; |
| |
| snprintf(bpf_lnk_dir, sizeof(bpf_lnk_dir), "%s%s/", base, link); |
| snprintf(bpf_sub_dir, sizeof(bpf_sub_dir), "%s%s", base, name); |
| |
| 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)); |
| return ret; |
| } |
| |
| return bpf_slave_via_bind_mnt(bpf_sub_dir, |
| bpf_lnk_dir); |
| } |
| |
| ret = lstat(bpf_sub_dir, &sb); |
| if (ret) { |
| fprintf(stderr, "lstat %s failed: %s\n", |
| bpf_sub_dir, strerror(errno)); |
| return ret; |
| } |
| |
| if ((sb.st_mode & S_IFMT) != S_IFLNK) |
| return bpf_gen_global(bpf_sub_dir); |
| } |
| |
| return 0; |
| } |
| |
| 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[PATH_MAX]; |
| static const char *mnt; |
| static bool bpf_mnt_cached; |
| static const char * const bpf_known_mnts[] = { |
| BPF_DIR_MNT, |
| "/bpf", |
| 0, |
| }; |
| int ret; |
| |
| if (bpf_mnt_cached) { |
| const char *out = mnt; |
| |
| if (out) { |
| snprintf(bpf_tmp, sizeof(bpf_tmp), "%s%s/", |
| out, bpf_prog_to_subdir(type)); |
| out = bpf_tmp; |
| } |
| return out; |
| } |
| |
| mnt = bpf_find_mntpt("bpf", BPF_FS_MAGIC, bpf_tmp, sizeof(bpf_tmp), |
| bpf_known_mnts); |
| if (!mnt) { |
| mnt = getenv(BPF_ENV_MNT); |
| if (!mnt) |
| mnt = BPF_DIR_MNT; |
| ret = bpf_mnt_fs(mnt); |
| if (ret) { |
| mnt = NULL; |
| goto out; |
| } |
| } |
| |
| snprintf(bpf_wrk_dir, sizeof(bpf_wrk_dir), "%s/", mnt); |
| |
| 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)); |
| } |
| |
| enum bpf_mode { |
| CBPF_BYTECODE, |
| CBPF_FILE, |
| EBPF_OBJECT, |
| EBPF_PINNED, |
| BPF_MODE_MAX, |
| }; |
| |
| static int bpf_parse(enum bpf_prog_type *type, enum bpf_mode *mode, |
| 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)) { |
| *mode = CBPF_BYTECODE; |
| } else if (opt_tbl[CBPF_FILE] && |
| (matches(*argv, "bytecode-file") == 0 || |
| strcmp(*argv, "bcf") == 0)) { |
| *mode = CBPF_FILE; |
| } else if (opt_tbl[EBPF_OBJECT] && |
| (matches(*argv, "object-file") == 0 || |
| strcmp(*argv, "obj") == 0)) { |
| *mode = EBPF_OBJECT; |
| } else if (opt_tbl[EBPF_PINNED] && |
| (matches(*argv, "object-pinned") == 0 || |
| matches(*argv, "pinned") == 0 || |
| matches(*argv, "fd") == 0)) { |
| *mode = EBPF_PINNED; |
| } else { |
| fprintf(stderr, "What mode is \"%s\"?\n", *argv); |
| return -1; |
| } |
| |
| NEXT_ARG(); |
| file = section = uds_name = NULL; |
| if (*mode == EBPF_OBJECT || *mode == EBPF_PINNED) { |
| file = *argv; |
| NEXT_ARG_FWD(); |
| |
| if (*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)) { |
| *type = i; |
| break; |
| } |
| } |
| |
| if (*type == BPF_PROG_TYPE_UNSPEC) { |
| fprintf(stderr, "What type is \"%s\"?\n", |
| *argv); |
| return -1; |
| } |
| NEXT_ARG_FWD(); |
| } else { |
| *type = BPF_PROG_TYPE_SCHED_CLS; |
| } |
| } |
| |
| section = bpf_prog_to_default_section(*type); |
| if (argc > 0 && matches(*argv, "section") == 0) { |
| NEXT_ARG(); |
| section = *argv; |
| NEXT_ARG_FWD(); |
| } |
| |
| if (__bpf_prog_meta[*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 (*mode == CBPF_BYTECODE || *mode == CBPF_FILE) |
| ret = bpf_ops_parse(argc, argv, cfg->ops, *mode == CBPF_FILE); |
| else if (*mode == EBPF_OBJECT) |
| ret = bpf_obj_open(file, *type, section, verbose); |
| else if (*mode == EBPF_PINNED) |
| ret = bpf_obj_get(file, *type); |
| else |
| return -1; |
| |
| cfg->object = file; |
| cfg->section = section; |
| cfg->uds = uds_name; |
| cfg->argc = argc; |
| cfg->argv = argv; |
| |
| return ret; |
| } |
| |
| static int bpf_parse_opt_tbl(enum bpf_prog_type type, struct bpf_cfg_in *cfg, |
| const struct bpf_cfg_ops *ops, void *nl, |
| const bool *opt_tbl) |
| { |
| struct sock_filter opcodes[BPF_MAXINSNS]; |
| char annotation[256]; |
| enum bpf_mode mode; |
| int ret; |
| |
| cfg->ops = opcodes; |
| ret = bpf_parse(&type, &mode, cfg, opt_tbl); |
| cfg->ops = NULL; |
| if (ret < 0) |
| return ret; |
| |
| if (mode == CBPF_BYTECODE || mode == CBPF_FILE) |
| ops->cbpf_cb(nl, opcodes, ret); |
| if (mode == EBPF_OBJECT || mode == EBPF_PINNED) { |
| snprintf(annotation, sizeof(annotation), "%s:[%s]", |
| basename(cfg->object), mode == EBPF_PINNED ? |
| "*fsobj" : cfg->section); |
| ops->ebpf_cb(nl, ret, annotation); |
| } |
| |
| return 0; |
| } |
| |
| int bpf_parse_common(enum bpf_prog_type type, struct bpf_cfg_in *cfg, |
| const struct bpf_cfg_ops *ops, void *nl) |
| { |
| 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_parse_opt_tbl(type, cfg, ops, nl, opt_tbl); |
| } |
| |
| int bpf_graft_map(const char *map_path, uint32_t *key, int argc, char **argv) |
| { |
| enum bpf_prog_type type = BPF_PROG_TYPE_UNSPEC; |
| 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 = { |
| .argc = argc, |
| .argv = argv, |
| }; |
| int ret, prog_fd, map_fd; |
| enum bpf_mode mode; |
| uint32_t map_key; |
| |
| prog_fd = bpf_parse(&type, &mode, &cfg, opt_tbl); |
| if (prog_fd < 0) |
| return 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, 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, |
| offsetof(struct bpf_elf_map, max_elem)); |
| 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; |
| } |
| |
| #ifdef HAVE_ELF |
| struct bpf_elf_prog { |
| enum bpf_prog_type type; |
| const struct bpf_insn *insns; |
| size_t size; |
| const char *license; |
| }; |
| |
| struct bpf_hash_entry { |
| unsigned int pinning; |
| const char *subpath; |
| struct bpf_hash_entry *next; |
| }; |
| |
| struct bpf_elf_ctx { |
| Elf *elf_fd; |
| GElf_Ehdr elf_hdr; |
| Elf_Data *sym_tab; |
| Elf_Data *str_tab; |
| int obj_fd; |
| int map_fds[ELF_MAX_MAPS]; |
| struct bpf_elf_map maps[ELF_MAX_MAPS]; |
| int sym_num; |
| int map_num; |
| int map_len; |
| bool *sec_done; |
| int sec_maps; |
| char license[ELF_MAX_LICENSE_LEN]; |
| enum bpf_prog_type type; |
| bool verbose; |
| 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 __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 (ctx->log && ctx->log[0]) { |
| 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; |
| void *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; |
| |
| 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) |
| { |
| union bpf_attr attr = {}; |
| |
| attr.map_type = type; |
| attr.key_size = size_key; |
| attr.value_size = size_value; |
| attr.max_entries = max_elem; |
| attr.map_flags = flags; |
| |
| return bpf(BPF_MAP_CREATE, &attr, sizeof(attr)); |
| } |
| |
| static 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) |
| { |
| 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); |
| |
| 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)); |
| } |
| |
| 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) { |
| fprintf(stderr, "Cannot get AF_ALG socket: %s\n", |
| strerror(errno)); |
| return cfd; |
| } |
| |
| ret = bind(cfd, (struct sockaddr *)&alg, sizeof(alg)); |
| if (ret < 0) { |
| fprintf(stderr, "Error binding socket: %s\n", strerror(errno)); |
| goto out_cfd; |
| } |
| |
| ofd = accept(cfd, NULL, 0); |
| if (ofd < 0) { |
| fprintf(stderr, "Error accepting socket: %s\n", |
| strerror(errno)); |
| 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 const char *bpf_get_obj_uid(const char *pathname) |
| { |
| static bool bpf_uid_cached; |
| static char bpf_uid[64]; |
| uint8_t tmp[20]; |
| int ret; |
| |
| if (bpf_uid_cached) |
| goto done; |
| |
| ret = bpf_obj_hash(pathname, tmp, sizeof(tmp)); |
| if (ret) { |
| fprintf(stderr, "Object hashing failed!\n"); |
| return NULL; |
| } |
| |
| hexstring_n2a(tmp, sizeof(tmp), bpf_uid, sizeof(bpf_uid)); |
| bpf_uid_cached = true; |
| done: |
| return bpf_uid; |
| } |
| |
| static int bpf_init_env(const char *pathname) |
| { |
| 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"); |
| return 0; |
| } |
| |
| if (!bpf_get_obj_uid(pathname)) |
| return -1; |
| |
| return 0; |
| } |
| |
| 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), |
| bpf_get_obj_uid(NULL), 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[PATH_MAX]; |
| int ret; |
| |
| snprintf(tmp, sizeof(tmp), "%s/%s", bpf_get_work_dir(ctx->type), |
| bpf_get_obj_uid(NULL)); |
| |
| ret = mkdir(tmp, S_IRWXU); |
| if (ret && errno != EEXIST) { |
| fprintf(stderr, "mkdir %s failed: %s\n", tmp, strerror(errno)); |
| return ret; |
| } |
| |
| return 0; |
| } |
| |
| static int bpf_make_custom_path(const struct bpf_elf_ctx *ctx, |
| const char *todo) |
| { |
| char tmp[PATH_MAX], rem[PATH_MAX], *sub; |
| int ret; |
| |
| snprintf(tmp, sizeof(tmp), "%s/../", bpf_get_work_dir(ctx->type)); |
| snprintf(rem, sizeof(rem), "%s/", todo); |
| 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)); |
| return ret; |
| } |
| |
| sub = strtok(NULL, "/"); |
| } |
| |
| return 0; |
| } |
| |
| 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(prog->type, prog->insns, prog->size, |
| prog->license, 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) |
| { |
| 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", map->size_value); |
| fprintf(stderr, " - Max elems: %u\n", map->max_elem); |
| fprintf(stderr, " - Flags: %#x\n\n", map->flags); |
| } |
| |
| static int bpf_map_attach(const char *name, const struct bpf_elf_map *map, |
| struct bpf_elf_ctx *ctx) |
| { |
| int fd, ret; |
| |
| fd = bpf_probe_pinned(name, ctx, map->pinning); |
| if (fd > 0) { |
| ret = bpf_map_selfcheck_pinned(fd, map, |
| offsetof(struct bpf_elf_map, |
| id)); |
| 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; |
| } |
| |
| errno = 0; |
| fd = bpf_map_create(map->type, map->size_key, map->size_value, |
| map->max_elem, map->flags); |
| if (fd < 0 || ctx->verbose) { |
| bpf_map_report(fd, name, map, ctx); |
| if (fd < 0) |
| return fd; |
| } |
| |
| ret = bpf_place_pinned(fd, name, ctx, map->pinning); |
| if (ret < 0 && errno != EEXIST) { |
| fprintf(stderr, "Could not pin %s map: %s\n", name, |
| strerror(errno)); |
| close(fd); |
| 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 const char *bpf_map_fetch_name(struct bpf_elf_ctx *ctx, int which) |
| { |
| GElf_Sym sym; |
| int i; |
| |
| for (i = 0; i < ctx->sym_num; i++) { |
| if (gelf_getsym(ctx->sym_tab, i, &sym) != &sym) |
| continue; |
| |
| if (GELF_ST_BIND(sym.st_info) != STB_GLOBAL || |
| GELF_ST_TYPE(sym.st_info) != STT_NOTYPE || |
| sym.st_shndx != ctx->sec_maps || |
| sym.st_value / ctx->map_len != which) |
| continue; |
| |
| return bpf_str_tab_name(ctx, &sym); |
| } |
| |
| return NULL; |
| } |
| |
| static int bpf_maps_attach_all(struct bpf_elf_ctx *ctx) |
| { |
| const char *map_name; |
| int i, fd; |
| |
| for (i = 0; i < ctx->map_num; i++) { |
| map_name = bpf_map_fetch_name(ctx, i); |
| if (!map_name) |
| return -EIO; |
| |
| fd = bpf_map_attach(map_name, &ctx->maps[i], ctx); |
| if (fd < 0) |
| return fd; |
| |
| ctx->map_fds[i] = fd; |
| } |
| |
| 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++) { |
| if (gelf_getsym(ctx->sym_tab, i, &sym) != &sym) |
| continue; |
| |
| if (GELF_ST_BIND(sym.st_info) != STB_GLOBAL || |
| GELF_ST_TYPE(sym.st_info) != STT_NOTYPE || |
| 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++) { |
| if (gelf_getsym(ctx->sym_tab, i, &sym) != &sym) |
| continue; |
| if (GELF_ST_BIND(sym.st_info) != STB_GLOBAL || |
| GELF_ST_TYPE(sym.st_info) != STT_NOTYPE || |
| 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)); |
| |
| printf("Note: %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 bool bpf_has_map_data(const struct bpf_elf_ctx *ctx) |
| { |
| return ctx->sym_tab && ctx->str_tab && ctx->sec_maps; |
| } |
| |
| static int bpf_fetch_ancillary(struct bpf_elf_ctx *ctx) |
| { |
| 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_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; |
| } |
| |
| 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.insns = data.sec_data->d_buf; |
| prog.size = data.sec_data->d_size; |
| prog.license = ctx->license; |
| |
| fd = bpf_prog_attach(section, &prog, ctx); |
| if (fd < 0) |
| return fd; |
| |
| ctx->sec_done[i] = true; |
| break; |
| } |
| |
| return fd; |
| } |
| |
| static int bpf_apply_relo_data(struct bpf_elf_ctx *ctx, |
| struct bpf_elf_sec_data *data_relo, |
| struct bpf_elf_sec_data *data_insn) |
| { |
| Elf_Data *idata = data_insn->sec_data; |
| GElf_Shdr *rhdr = &data_relo->sec_hdr; |
| int relo_ent, relo_num = rhdr->sh_size / rhdr->sh_entsize; |
| struct bpf_insn *insns = idata->d_buf; |
| unsigned int num_insns = idata->d_size / sizeof(*insns); |
| |
| for (relo_ent = 0; relo_ent < relo_num; relo_ent++) { |
| unsigned int ioff, rmap; |
| GElf_Rel relo; |
| GElf_Sym sym; |
| |
| if (gelf_getrel(data_relo->sec_data, relo_ent, &relo) != &relo) |
| return -EIO; |
| |
| ioff = relo.r_offset / sizeof(struct bpf_insn); |
| if (ioff >= num_insns || |
| insns[ioff].code != (BPF_LD | BPF_IMM | BPF_DW)) { |
| fprintf(stderr, "ELF contains relo data for non ld64 instruction at offset %u! Compiler bug?!\n", |
| ioff); |
| if (ioff < num_insns && |
| insns[ioff].code == (BPF_JMP | BPF_CALL)) |
| fprintf(stderr, " - Try to annotate functions with always_inline attribute!\n"); |
| return -EINVAL; |
| } |
| |
| if (gelf_getsym(ctx->sym_tab, GELF_R_SYM(relo.r_info), &sym) != &sym) |
| return -EIO; |
| if (sym.st_shndx != ctx->sec_maps) { |
| fprintf(stderr, "ELF contains non-map related relo data in entry %u pointing to section %u! Compiler bug?!\n", |
| relo_ent, sym.st_shndx); |
| return -EIO; |
| } |
| |
| rmap = sym.st_value / ctx->map_len; |
| if (rmap >= ARRAY_SIZE(ctx->map_fds)) |
| return -EINVAL; |
| if (!ctx->map_fds[rmap]) |
| return -EINVAL; |
| |
| if (ctx->verbose) |
| fprintf(stderr, "Map \'%s\' (%d) injected into prog section \'%s\' at offset %u!\n", |
| bpf_str_tab_name(ctx, &sym), ctx->map_fds[rmap], |
| data_insn->sec_name, ioff); |
| |
| insns[ioff].src_reg = BPF_PSEUDO_MAP_FD; |
| insns[ioff].imm = ctx->map_fds[rmap]; |
| } |
| |
| return 0; |
| } |
| |
| static int bpf_fetch_prog_relo(struct bpf_elf_ctx *ctx, const char *section, |
| bool *lderr, bool *sseen) |
| { |
| struct bpf_elf_sec_data data_relo, data_insn; |
| struct bpf_elf_prog prog; |
| int ret, idx, i, fd = -1; |
| |
| for (i = 1; i < ctx->elf_hdr.e_shnum; i++) { |
| 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; |
| |
| *sseen = true; |
| |
| ret = bpf_apply_relo_data(ctx, &data_relo, &data_insn); |
| if (ret < 0) |
| return ret; |
| |
| memset(&prog, 0, sizeof(prog)); |
| prog.type = ctx->type; |
| prog.insns = data_insn.sec_data->d_buf; |
| prog.size = data_insn.sec_data->d_size; |
| prog.license = ctx->license; |
| |
| fd = bpf_prog_attach(section, &prog, ctx); |
| if (fd < 0) { |
| *lderr = true; |
| return fd; |
| } |
| |
| 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; |
| int ret = -1; |
| |
| if (bpf_has_map_data(ctx)) |
| ret = bpf_fetch_prog_relo(ctx, section, &lderr, &sseen); |
| 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; |
| } |
| |
| 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) { |
| if (errno == E2BIG) |
| fprintf(stderr, "Tail call key %u for map %u out of bounds?\n", |
| key_id, map_id); |
| return -errno; |
| } |
| |
| 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); |
| } |
| } |
| } |
| |
| static int bpf_elf_check_ehdr(const struct bpf_elf_ctx *ctx) |
| { |
| if (ctx->elf_hdr.e_type != ET_REL || |
| (ctx->elf_hdr.e_machine != EM_NONE && |
| ctx->elf_hdr.e_machine != EM_BPF) || |
| ctx->elf_hdr.e_version != EV_CURRENT) { |
| fprintf(stderr, "ELF format error, ELF file not for eBPF?\n"); |
| return -EINVAL; |
| } |
| |
| switch (ctx->elf_hdr.e_ident[EI_DATA]) { |
| default: |
| fprintf(stderr, "ELF format error, wrong endianness info?\n"); |
| return -EINVAL; |
| case ELFDATA2LSB: |
| if (htons(1) == 1) { |
| fprintf(stderr, |
| "We are big endian, eBPF object is little endian!\n"); |
| return -EIO; |
| } |
| break; |
| case ELFDATA2MSB: |
| if (htons(1) != 1) { |
| fprintf(stderr, |
| "We are little endian, eBPF object is big endian!\n"); |
| return -EIO; |
| } |
| break; |
| } |
| |
| return 0; |
| } |
| |
| static int bpf_elf_ctx_init(struct bpf_elf_ctx *ctx, const char *pathname, |
| enum bpf_prog_type type, bool verbose) |
| { |
| int ret = -EINVAL; |
| |
| if (elf_version(EV_CURRENT) == EV_NONE || |
| bpf_init_env(pathname)) |
| return ret; |
| |
| memset(ctx, 0, sizeof(*ctx)); |
| ctx->verbose = verbose; |
| ctx->type = type; |
| |
| ctx->obj_fd = open(pathname, O_RDONLY); |
| if (ctx->obj_fd < 0) |
| return ctx->obj_fd; |
| |
| ctx->elf_fd = elf_begin(ctx->obj_fd, ELF_C_READ, NULL); |
| if (!ctx->elf_fd) { |
| ret = -EINVAL; |
| goto out_fd; |
| } |
| |
| if (elf_kind(ctx->elf_fd) != ELF_K_ELF) { |
| ret = -EINVAL; |
| goto out_fd; |
| } |
| |
| if (gelf_getehdr(ctx->elf_fd, &ctx->elf_hdr) != |
| &ctx->elf_hdr) { |
| ret = -EIO; |
| goto out_elf; |
| } |
| |
| ret = bpf_elf_check_ehdr(ctx); |
| if (ret < 0) |
| goto out_elf; |
| |
| ctx->sec_done = calloc(ctx->elf_hdr.e_shnum, |
| sizeof(*(ctx->sec_done))); |
| if (!ctx->sec_done) { |
| ret = -ENOMEM; |
| goto out_elf; |
| } |
| |
| if (ctx->verbose && bpf_log_realloc(ctx)) { |
| ret = -ENOMEM; |
| goto out_free; |
| } |
| |
| bpf_save_finfo(ctx); |
| bpf_hash_init(ctx, CONFDIR "/bpf_pinning"); |
| |
| return 0; |
| out_free: |
| free(ctx->sec_done); |
| out_elf: |
| elf_end(ctx->elf_fd); |
| out_fd: |
| close(ctx->obj_fd); |
| return ret; |
| } |
| |
| static int bpf_maps_count(struct bpf_elf_ctx *ctx) |
| { |
| int i, count = 0; |
| |
| for (i = 0; i < ARRAY_SIZE(ctx->map_fds); i++) { |
| if (!ctx->map_fds[i]) |
| break; |
| count++; |
| } |
| |
| return count; |
| } |
| |
| static void bpf_maps_teardown(struct bpf_elf_ctx *ctx) |
| { |
| int i; |
| |
| for (i = 0; i < ARRAY_SIZE(ctx->map_fds); i++) { |
| if (ctx->map_fds[i]) |
| close(ctx->map_fds[i]); |
| } |
| } |
| |
| static void bpf_elf_ctx_destroy(struct bpf_elf_ctx *ctx, bool failure) |
| { |
| if (failure) |
| bpf_maps_teardown(ctx); |
| |
| bpf_hash_destroy(ctx); |
| |
| free(ctx->sec_done); |
| free(ctx->log); |
| |
| elf_end(ctx->elf_fd); |
| close(ctx->obj_fd); |
| } |
| |
| static struct bpf_elf_ctx __ctx; |
| |
| static int bpf_obj_open(const char *pathname, enum bpf_prog_type type, |
| const char *section, bool verbose) |
| { |
| struct bpf_elf_ctx *ctx = &__ctx; |
| int fd = 0, ret; |
| |
| ret = bpf_elf_ctx_init(ctx, pathname, type, verbose); |
| if (ret < 0) { |
| fprintf(stderr, "Cannot initialize ELF context!\n"); |
| return ret; |
| } |
| |
| ret = bpf_fetch_ancillary(ctx); |
| if (ret < 0) { |
| fprintf(stderr, "Error fetching ELF ancillary data!\n"); |
| goto out; |
| } |
| |
| fd = bpf_fetch_prog_sec(ctx, section); |
| if (fd < 0) { |
| fprintf(stderr, "Error fetching program/map!\n"); |
| ret = fd; |
| goto out; |
| } |
| |
| ret = bpf_fill_prog_arrays(ctx); |
| if (ret < 0) |
| fprintf(stderr, "Error filling program arrays!\n"); |
| out: |
| bpf_elf_ctx_destroy(ctx, ret < 0); |
| if (ret < 0) { |
| if (fd) |
| close(fd); |
| return ret; |
| } |
| |
| return fd; |
| } |
| |
| static int |
| bpf_map_set_send(int fd, struct sockaddr_un *addr, unsigned int addr_len, |
| const struct bpf_map_data *aux, unsigned int entries) |
| { |
| struct bpf_map_set_msg msg = { |
| .aux.uds_ver = BPF_SCM_AUX_VER, |
| .aux.num_ent = entries, |
| }; |
| int *cmsg_buf, min_fd; |
| char *amsg_buf; |
| int i; |
| |
| strncpy(msg.aux.obj_name, aux->obj, sizeof(msg.aux.obj_name)); |
| memcpy(&msg.aux.obj_st, aux->st, sizeof(msg.aux.obj_st)); |
| |
| cmsg_buf = bpf_map_set_init(&msg, addr, addr_len); |
| amsg_buf = (char *)msg.aux.ent; |
| |
| for (i = 0; i < entries; i += min_fd) { |
| int ret; |
| |
| min_fd = min(BPF_SCM_MAX_FDS * 1U, entries - i); |
| bpf_map_set_init_single(&msg, min_fd); |
| |
| memcpy(cmsg_buf, &aux->fds[i], sizeof(aux->fds[0]) * min_fd); |
| memcpy(amsg_buf, &aux->ent[i], sizeof(aux->ent[0]) * min_fd); |
| |
| ret = sendmsg(fd, &msg.hdr, 0); |
| if (ret <= 0) |
| return ret ? : -1; |
| } |
| |
| return 0; |
| } |
| |
| static int |
| bpf_map_set_recv(int fd, int *fds, struct bpf_map_aux *aux, |
| unsigned int entries) |
| { |
| struct bpf_map_set_msg msg; |
| int *cmsg_buf, min_fd; |
| char *amsg_buf, *mmsg_buf; |
| unsigned int needed = 1; |
| int i; |
| |
| cmsg_buf = bpf_map_set_init(&msg, NULL, 0); |
| amsg_buf = (char *)msg.aux.ent; |
| mmsg_buf = (char *)&msg.aux; |
| |
| for (i = 0; i < min(entries, needed); i += min_fd) { |
| struct cmsghdr *cmsg; |
| int ret; |
| |
| min_fd = min(entries, entries - i); |
| bpf_map_set_init_single(&msg, min_fd); |
| |
| ret = recvmsg(fd, &msg.hdr, 0); |
| if (ret <= 0) |
| return ret ? : -1; |
| |
| cmsg = CMSG_FIRSTHDR(&msg.hdr); |
| if (!cmsg || cmsg->cmsg_type != SCM_RIGHTS) |
| return -EINVAL; |
| if (msg.hdr.msg_flags & MSG_CTRUNC) |
| return -EIO; |
| if (msg.aux.uds_ver != BPF_SCM_AUX_VER) |
| return -ENOSYS; |
| |
| min_fd = (cmsg->cmsg_len - sizeof(*cmsg)) / sizeof(fd); |
| if (min_fd > entries || min_fd <= 0) |
| return -EINVAL; |
| |
| memcpy(&fds[i], cmsg_buf, sizeof(fds[0]) * min_fd); |
| memcpy(&aux->ent[i], amsg_buf, sizeof(aux->ent[0]) * min_fd); |
| memcpy(aux, mmsg_buf, offsetof(struct bpf_map_aux, ent)); |
| |
| needed = aux->num_ent; |
| } |
| |
| return 0; |
| } |
| |
| int bpf_send_map_fds(const char *path, const char *obj) |
| { |
| struct bpf_elf_ctx *ctx = &__ctx; |
| struct sockaddr_un addr = { .sun_family = AF_UNIX }; |
| struct bpf_map_data bpf_aux = { |
| .fds = ctx->map_fds, |
| .ent = ctx->maps, |
| .st = &ctx->stat, |
| .obj = obj, |
| }; |
| int fd, ret; |
| |
| fd = socket(AF_UNIX, SOCK_DGRAM, 0); |
| if (fd < 0) { |
| fprintf(stderr, "Cannot open socket: %s\n", |
| strerror(errno)); |
| return -1; |
| } |
| |
| strncpy(addr.sun_path, path, sizeof(addr.sun_path)); |
| |
| ret = connect(fd, (struct sockaddr *)&addr, sizeof(addr)); |
| if (ret < 0) { |
| fprintf(stderr, "Cannot connect to %s: %s\n", |
| path, strerror(errno)); |
| return -1; |
| } |
| |
| ret = bpf_map_set_send(fd, &addr, sizeof(addr), &bpf_aux, |
| bpf_maps_count(ctx)); |
| if (ret < 0) |
| fprintf(stderr, "Cannot send fds to %s: %s\n", |
| path, strerror(errno)); |
| |
| bpf_maps_teardown(ctx); |
| close(fd); |
| return ret; |
| } |
| |
| int bpf_recv_map_fds(const char *path, int *fds, struct bpf_map_aux *aux, |
| unsigned int entries) |
| { |
| struct sockaddr_un addr = { .sun_family = AF_UNIX }; |
| int fd, ret; |
| |
| fd = socket(AF_UNIX, SOCK_DGRAM, 0); |
| if (fd < 0) { |
| fprintf(stderr, "Cannot open socket: %s\n", |
| strerror(errno)); |
| return -1; |
| } |
| |
| strncpy(addr.sun_path, path, sizeof(addr.sun_path)); |
| |
| ret = bind(fd, (struct sockaddr *)&addr, sizeof(addr)); |
| if (ret < 0) { |
| fprintf(stderr, "Cannot bind to socket: %s\n", |
| strerror(errno)); |
| return -1; |
| } |
| |
| ret = bpf_map_set_recv(fd, fds, aux, entries); |
| if (ret < 0) |
| fprintf(stderr, "Cannot recv fds from %s: %s\n", |
| path, strerror(errno)); |
| |
| unlink(addr.sun_path); |
| close(fd); |
| return ret; |
| } |
| #endif /* HAVE_ELF */ |