diff options
Diffstat (limited to 'tools/lib/bpf/libbpf.c')
| -rw-r--r-- | tools/lib/bpf/libbpf.c | 284 |
1 files changed, 162 insertions, 122 deletions
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 2abd0f112627..b607be7236d3 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -1,4 +1,4 @@ -// SPDX-License-Identifier: LGPL-2.1 +// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) /* * Common eBPF ELF object loading operations. @@ -7,19 +7,6 @@ * Copyright (C) 2015 Wang Nan <wangnan0@huawei.com> * Copyright (C) 2015 Huawei Inc. * Copyright (C) 2017 Nicira, Inc. - * - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU Lesser General Public - * License as published by the Free Software Foundation; - * version 2.1 of the License (not later!) - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU Lesser General Public License for more details. - * - * You should have received a copy of the GNU Lesser General Public - * License along with this program; if not, see <http://www.gnu.org/licenses> */ #define _GNU_SOURCE @@ -32,7 +19,6 @@ #include <unistd.h> #include <fcntl.h> #include <errno.h> -#include <perf-sys.h> #include <asm/unistd.h> #include <linux/err.h> #include <linux/kernel.h> @@ -40,6 +26,8 @@ #include <linux/btf.h> #include <linux/list.h> #include <linux/limits.h> +#include <linux/perf_event.h> +#include <linux/ring_buffer.h> #include <sys/stat.h> #include <sys/types.h> #include <sys/vfs.h> @@ -50,6 +38,7 @@ #include "libbpf.h" #include "bpf.h" #include "btf.h" +#include "str_error.h" #ifndef EM_BPF #define EM_BPF 247 @@ -181,7 +170,7 @@ static LIST_HEAD(bpf_objects_list); struct bpf_object { char license[64]; - u32 kern_version; + __u32 kern_version; struct bpf_program *programs; size_t nr_programs; @@ -227,7 +216,7 @@ struct bpf_object { }; #define obj_elf_valid(o) ((o)->efile.elf) -static void bpf_program__unload(struct bpf_program *prog) +void bpf_program__unload(struct bpf_program *prog) { int i; @@ -469,7 +458,8 @@ static int bpf_object__elf_init(struct bpf_object *obj) obj->efile.fd = open(obj->path, O_RDONLY); if (obj->efile.fd < 0) { char errmsg[STRERR_BUFSIZE]; - char *cp = strerror_r(errno, errmsg, sizeof(errmsg)); + char *cp = libbpf_strerror_r(errno, errmsg, + sizeof(errmsg)); pr_warning("failed to open %s: %s\n", obj->path, cp); return -errno; @@ -551,7 +541,7 @@ static int bpf_object__init_kversion(struct bpf_object *obj, void *data, size_t size) { - u32 kver; + __u32 kver; if (size != sizeof(kver)) { pr_warning("invalid kver section in %s\n", obj->path); @@ -573,8 +563,9 @@ static int compare_bpf_map(const void *_a, const void *_b) } static int -bpf_object__init_maps(struct bpf_object *obj) +bpf_object__init_maps(struct bpf_object *obj, int flags) { + bool strict = !(flags & MAPS_RELAX_COMPAT); int i, map_idx, map_def_sz, nr_maps = 0; Elf_Scn *scn; Elf_Data *data; @@ -696,7 +687,8 @@ bpf_object__init_maps(struct bpf_object *obj) "has unrecognized, non-zero " "options\n", obj->path, map_name); - return -EINVAL; + if (strict) + return -EINVAL; } } memcpy(&obj->maps[map_idx].def, def, @@ -727,7 +719,7 @@ static bool section_have_execinstr(struct bpf_object *obj, int idx) return false; } -static int bpf_object__elf_collect(struct bpf_object *obj) +static int bpf_object__elf_collect(struct bpf_object *obj, int flags) { Elf *elf = obj->efile.elf; GElf_Ehdr *ep = &obj->efile.ehdr; @@ -810,8 +802,8 @@ static int bpf_object__elf_collect(struct bpf_object *obj) data->d_size, name, idx); if (err) { char errmsg[STRERR_BUFSIZE]; - char *cp = strerror_r(-err, errmsg, - sizeof(errmsg)); + char *cp = libbpf_strerror_r(-err, errmsg, + sizeof(errmsg)); pr_warning("failed to alloc program %s (%s): %s", name, obj->path, cp); @@ -854,7 +846,7 @@ static int bpf_object__elf_collect(struct bpf_object *obj) return LIBBPF_ERRNO__FORMAT; } if (obj->efile.maps_shndx >= 0) { - err = bpf_object__init_maps(obj); + err = bpf_object__init_maps(obj, flags); if (err) goto out; } @@ -1140,7 +1132,7 @@ bpf_object__create_maps(struct bpf_object *obj) *pfd = bpf_create_map_xattr(&create_attr); if (*pfd < 0 && create_attr.btf_key_type_id) { - cp = strerror_r(errno, errmsg, sizeof(errmsg)); + cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg)); pr_warning("Error in bpf_create_map_xattr(%s):%s(%d). Retrying without BTF.\n", map->name, cp, errno); create_attr.btf_fd = 0; @@ -1155,7 +1147,7 @@ bpf_object__create_maps(struct bpf_object *obj) size_t j; err = *pfd; - cp = strerror_r(errno, errmsg, sizeof(errmsg)); + cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg)); pr_warning("failed to create map (name: '%s'): %s\n", map->name, cp); for (j = 0; j < i; j++) @@ -1306,7 +1298,7 @@ static int bpf_object__collect_reloc(struct bpf_object *obj) static int load_program(enum bpf_prog_type type, enum bpf_attach_type expected_attach_type, const char *name, struct bpf_insn *insns, int insns_cnt, - char *license, u32 kern_version, int *pfd, int prog_ifindex) + char *license, __u32 kern_version, int *pfd, int prog_ifindex) { struct bpf_load_program_attr load_attr; char *cp, errmsg[STRERR_BUFSIZE]; @@ -1339,7 +1331,7 @@ load_program(enum bpf_prog_type type, enum bpf_attach_type expected_attach_type, } ret = -LIBBPF_ERRNO__LOAD; - cp = strerror_r(errno, errmsg, sizeof(errmsg)); + cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg)); pr_warning("load bpf program failed: %s\n", cp); if (log_buf && log_buf[0] != '\0') { @@ -1375,9 +1367,9 @@ out: return ret; } -static int +int bpf_program__load(struct bpf_program *prog, - char *license, u32 kern_version) + char *license, __u32 kern_version) { int err = 0, fd, i; @@ -1502,6 +1494,7 @@ static bool bpf_prog_type__needs_kver(enum bpf_prog_type type) case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: case BPF_PROG_TYPE_LIRC_MODE2: case BPF_PROG_TYPE_SK_REUSEPORT: + case BPF_PROG_TYPE_FLOW_DISSECTOR: return false; case BPF_PROG_TYPE_UNSPEC: case BPF_PROG_TYPE_KPROBE: @@ -1525,7 +1518,7 @@ static int bpf_object__validate(struct bpf_object *obj, bool needs_kver) static struct bpf_object * __bpf_object__open(const char *path, void *obj_buf, size_t obj_buf_sz, - bool needs_kver) + bool needs_kver, int flags) { struct bpf_object *obj; int err; @@ -1541,7 +1534,7 @@ __bpf_object__open(const char *path, void *obj_buf, size_t obj_buf_sz, CHECK_ERR(bpf_object__elf_init(obj), err, out); CHECK_ERR(bpf_object__check_endianness(obj), err, out); - CHECK_ERR(bpf_object__elf_collect(obj), err, out); + CHECK_ERR(bpf_object__elf_collect(obj, flags), err, out); CHECK_ERR(bpf_object__collect_reloc(obj), err, out); CHECK_ERR(bpf_object__validate(obj, needs_kver), err, out); @@ -1552,7 +1545,8 @@ out: return ERR_PTR(err); } -struct bpf_object *bpf_object__open_xattr(struct bpf_object_open_attr *attr) +struct bpf_object *__bpf_object__open_xattr(struct bpf_object_open_attr *attr, + int flags) { /* param validation */ if (!attr->file) @@ -1561,7 +1555,13 @@ struct bpf_object *bpf_object__open_xattr(struct bpf_object_open_attr *attr) pr_debug("loading %s\n", attr->file); return __bpf_object__open(attr->file, NULL, 0, - bpf_prog_type__needs_kver(attr->prog_type)); + bpf_prog_type__needs_kver(attr->prog_type), + flags); +} + +struct bpf_object *bpf_object__open_xattr(struct bpf_object_open_attr *attr) +{ + return __bpf_object__open_xattr(attr, 0); } struct bpf_object *bpf_object__open(const char *path) @@ -1594,7 +1594,7 @@ struct bpf_object *bpf_object__open_buffer(void *obj_buf, pr_debug("loading object '%s' from buffer\n", name); - return __bpf_object__open(name, obj_buf, obj_buf_sz, true); + return __bpf_object__open(name, obj_buf, obj_buf_sz, true, true); } int bpf_object__unload(struct bpf_object *obj) @@ -1654,7 +1654,7 @@ static int check_path(const char *path) dir = dirname(dname); if (statfs(dir, &st_fs)) { - cp = strerror_r(errno, errmsg, sizeof(errmsg)); + cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg)); pr_warning("failed to statfs %s: %s\n", dir, cp); err = -errno; } @@ -1690,7 +1690,7 @@ int bpf_program__pin_instance(struct bpf_program *prog, const char *path, } if (bpf_obj_pin(prog->instances.fds[instance], path)) { - cp = strerror_r(errno, errmsg, sizeof(errmsg)); + cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg)); pr_warning("failed to pin program: %s\n", cp); return -errno; } @@ -1708,7 +1708,7 @@ static int make_dir(const char *path) err = -errno; if (err) { - cp = strerror_r(-err, errmsg, sizeof(errmsg)); + cp = libbpf_strerror_r(-err, errmsg, sizeof(errmsg)); pr_warning("failed to mkdir %s: %s\n", path, cp); } return err; @@ -1770,7 +1770,7 @@ int bpf_map__pin(struct bpf_map *map, const char *path) } if (bpf_obj_pin(map->fd, path)) { - cp = strerror_r(errno, errmsg, sizeof(errmsg)); + cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg)); pr_warning("failed to pin map: %s\n", cp); return -errno; } @@ -2084,57 +2084,90 @@ void bpf_program__set_expected_attach_type(struct bpf_program *prog, prog->expected_attach_type = type; } -#define BPF_PROG_SEC_FULL(string, ptype, atype) \ - { string, sizeof(string) - 1, ptype, atype } +#define BPF_PROG_SEC_IMPL(string, ptype, eatype, atype) \ + { string, sizeof(string) - 1, ptype, eatype, atype } -#define BPF_PROG_SEC(string, ptype) BPF_PROG_SEC_FULL(string, ptype, 0) +/* Programs that can NOT be attached. */ +#define BPF_PROG_SEC(string, ptype) BPF_PROG_SEC_IMPL(string, ptype, 0, -EINVAL) -#define BPF_S_PROG_SEC(string, ptype) \ - BPF_PROG_SEC_FULL(string, BPF_PROG_TYPE_CGROUP_SOCK, ptype) +/* Programs that can be attached. */ +#define BPF_APROG_SEC(string, ptype, atype) \ + BPF_PROG_SEC_IMPL(string, ptype, 0, atype) -#define BPF_SA_PROG_SEC(string, ptype) \ - BPF_PROG_SEC_FULL(string, BPF_PROG_TYPE_CGROUP_SOCK_ADDR, ptype) +/* Programs that must specify expected attach type at load time. */ +#define BPF_EAPROG_SEC(string, ptype, eatype) \ + BPF_PROG_SEC_IMPL(string, ptype, eatype, eatype) + +/* Programs that can be attached but attach type can't be identified by section + * name. Kept for backward compatibility. + */ +#define BPF_APROG_COMPAT(string, ptype) BPF_PROG_SEC(string, ptype) static const struct { const char *sec; size_t len; enum bpf_prog_type prog_type; enum bpf_attach_type expected_attach_type; + enum bpf_attach_type attach_type; } section_names[] = { - BPF_PROG_SEC("socket", BPF_PROG_TYPE_SOCKET_FILTER), - BPF_PROG_SEC("kprobe/", BPF_PROG_TYPE_KPROBE), - BPF_PROG_SEC("kretprobe/", BPF_PROG_TYPE_KPROBE), - BPF_PROG_SEC("classifier", BPF_PROG_TYPE_SCHED_CLS), - BPF_PROG_SEC("action", BPF_PROG_TYPE_SCHED_ACT), - BPF_PROG_SEC("tracepoint/", BPF_PROG_TYPE_TRACEPOINT), - BPF_PROG_SEC("raw_tracepoint/", BPF_PROG_TYPE_RAW_TRACEPOINT), - BPF_PROG_SEC("xdp", BPF_PROG_TYPE_XDP), - BPF_PROG_SEC("perf_event", BPF_PROG_TYPE_PERF_EVENT), - BPF_PROG_SEC("cgroup/skb", BPF_PROG_TYPE_CGROUP_SKB), - BPF_PROG_SEC("cgroup/sock", BPF_PROG_TYPE_CGROUP_SOCK), - BPF_PROG_SEC("cgroup/dev", BPF_PROG_TYPE_CGROUP_DEVICE), - BPF_PROG_SEC("lwt_in", BPF_PROG_TYPE_LWT_IN), - BPF_PROG_SEC("lwt_out", BPF_PROG_TYPE_LWT_OUT), - BPF_PROG_SEC("lwt_xmit", BPF_PROG_TYPE_LWT_XMIT), - BPF_PROG_SEC("lwt_seg6local", BPF_PROG_TYPE_LWT_SEG6LOCAL), - BPF_PROG_SEC("sockops", BPF_PROG_TYPE_SOCK_OPS), - BPF_PROG_SEC("sk_skb", BPF_PROG_TYPE_SK_SKB), - BPF_PROG_SEC("sk_msg", BPF_PROG_TYPE_SK_MSG), - BPF_PROG_SEC("lirc_mode2", BPF_PROG_TYPE_LIRC_MODE2), - BPF_SA_PROG_SEC("cgroup/bind4", BPF_CGROUP_INET4_BIND), - BPF_SA_PROG_SEC("cgroup/bind6", BPF_CGROUP_INET6_BIND), - BPF_SA_PROG_SEC("cgroup/connect4", BPF_CGROUP_INET4_CONNECT), - BPF_SA_PROG_SEC("cgroup/connect6", BPF_CGROUP_INET6_CONNECT), - BPF_SA_PROG_SEC("cgroup/sendmsg4", BPF_CGROUP_UDP4_SENDMSG), - BPF_SA_PROG_SEC("cgroup/sendmsg6", BPF_CGROUP_UDP6_SENDMSG), - BPF_S_PROG_SEC("cgroup/post_bind4", BPF_CGROUP_INET4_POST_BIND), - BPF_S_PROG_SEC("cgroup/post_bind6", BPF_CGROUP_INET6_POST_BIND), + BPF_PROG_SEC("socket", BPF_PROG_TYPE_SOCKET_FILTER), + BPF_PROG_SEC("kprobe/", BPF_PROG_TYPE_KPROBE), + BPF_PROG_SEC("kretprobe/", BPF_PROG_TYPE_KPROBE), + BPF_PROG_SEC("classifier", BPF_PROG_TYPE_SCHED_CLS), + BPF_PROG_SEC("action", BPF_PROG_TYPE_SCHED_ACT), + BPF_PROG_SEC("tracepoint/", BPF_PROG_TYPE_TRACEPOINT), + BPF_PROG_SEC("raw_tracepoint/", BPF_PROG_TYPE_RAW_TRACEPOINT), + BPF_PROG_SEC("xdp", BPF_PROG_TYPE_XDP), + BPF_PROG_SEC("perf_event", BPF_PROG_TYPE_PERF_EVENT), + BPF_PROG_SEC("lwt_in", BPF_PROG_TYPE_LWT_IN), + BPF_PROG_SEC("lwt_out", BPF_PROG_TYPE_LWT_OUT), + BPF_PROG_SEC("lwt_xmit", BPF_PROG_TYPE_LWT_XMIT), + BPF_PROG_SEC("lwt_seg6local", BPF_PROG_TYPE_LWT_SEG6LOCAL), + BPF_APROG_SEC("cgroup_skb/ingress", BPF_PROG_TYPE_CGROUP_SKB, + BPF_CGROUP_INET_INGRESS), + BPF_APROG_SEC("cgroup_skb/egress", BPF_PROG_TYPE_CGROUP_SKB, + BPF_CGROUP_INET_EGRESS), + BPF_APROG_COMPAT("cgroup/skb", BPF_PROG_TYPE_CGROUP_SKB), + BPF_APROG_SEC("cgroup/sock", BPF_PROG_TYPE_CGROUP_SOCK, + BPF_CGROUP_INET_SOCK_CREATE), + BPF_EAPROG_SEC("cgroup/post_bind4", BPF_PROG_TYPE_CGROUP_SOCK, + BPF_CGROUP_INET4_POST_BIND), + BPF_EAPROG_SEC("cgroup/post_bind6", BPF_PROG_TYPE_CGROUP_SOCK, + BPF_CGROUP_INET6_POST_BIND), + BPF_APROG_SEC("cgroup/dev", BPF_PROG_TYPE_CGROUP_DEVICE, + BPF_CGROUP_DEVICE), + BPF_APROG_SEC("sockops", BPF_PROG_TYPE_SOCK_OPS, + BPF_CGROUP_SOCK_OPS), + BPF_APROG_SEC("sk_skb/stream_parser", BPF_PROG_TYPE_SK_SKB, + BPF_SK_SKB_STREAM_PARSER), + BPF_APROG_SEC("sk_skb/stream_verdict", BPF_PROG_TYPE_SK_SKB, + BPF_SK_SKB_STREAM_VERDICT), + BPF_APROG_COMPAT("sk_skb", BPF_PROG_TYPE_SK_SKB), + BPF_APROG_SEC("sk_msg", BPF_PROG_TYPE_SK_MSG, + BPF_SK_MSG_VERDICT), + BPF_APROG_SEC("lirc_mode2", BPF_PROG_TYPE_LIRC_MODE2, + BPF_LIRC_MODE2), + BPF_APROG_SEC("flow_dissector", BPF_PROG_TYPE_FLOW_DISSECTOR, + BPF_FLOW_DISSECTOR), + BPF_EAPROG_SEC("cgroup/bind4", BPF_PROG_TYPE_CGROUP_SOCK_ADDR, + BPF_CGROUP_INET4_BIND), + BPF_EAPROG_SEC("cgroup/bind6", BPF_PROG_TYPE_CGROUP_SOCK_ADDR, + BPF_CGROUP_INET6_BIND), + BPF_EAPROG_SEC("cgroup/connect4", BPF_PROG_TYPE_CGROUP_SOCK_ADDR, + BPF_CGROUP_INET4_CONNECT), + BPF_EAPROG_SEC("cgroup/connect6", BPF_PROG_TYPE_CGROUP_SOCK_ADDR, + BPF_CGROUP_INET6_CONNECT), + BPF_EAPROG_SEC("cgroup/sendmsg4", BPF_PROG_TYPE_CGROUP_SOCK_ADDR, + BPF_CGROUP_UDP4_SENDMSG), + BPF_EAPROG_SEC("cgroup/sendmsg6", BPF_PROG_TYPE_CGROUP_SOCK_ADDR, + BPF_CGROUP_UDP6_SENDMSG), }; +#undef BPF_PROG_SEC_IMPL #undef BPF_PROG_SEC -#undef BPF_PROG_SEC_FULL -#undef BPF_S_PROG_SEC -#undef BPF_SA_PROG_SEC +#undef BPF_APROG_SEC +#undef BPF_EAPROG_SEC +#undef BPF_APROG_COMPAT int libbpf_prog_type_by_name(const char *name, enum bpf_prog_type *prog_type, enum bpf_attach_type *expected_attach_type) @@ -2154,6 +2187,25 @@ int libbpf_prog_type_by_name(const char *name, enum bpf_prog_type *prog_type, return -EINVAL; } +int libbpf_attach_type_by_name(const char *name, + enum bpf_attach_type *attach_type) +{ + int i; + + if (!name) + return -EINVAL; + + for (i = 0; i < ARRAY_SIZE(section_names); i++) { + if (strncmp(name, section_names[i].sec, section_names[i].len)) + continue; + if (section_names[i].attach_type == -EINVAL) + return -EINVAL; + *attach_type = section_names[i].attach_type; + return 0; + } + return -EINVAL; +} + static int bpf_program__identify_section(struct bpf_program *prog, enum bpf_prog_type *prog_type, @@ -2336,7 +2388,7 @@ int bpf_prog_load_xattr(const struct bpf_prog_load_attr *attr, bpf_program__set_expected_attach_type(prog, expected_attach_type); - if (!bpf_program__is_function_storage(prog, obj) && !first_prog) + if (!first_prog) first_prog = prog; } @@ -2363,61 +2415,49 @@ int bpf_prog_load_xattr(const struct bpf_prog_load_attr *attr, } enum bpf_perf_event_ret -bpf_perf_event_read_simple(void *mem, unsigned long size, - unsigned long page_size, void **buf, size_t *buf_len, - bpf_perf_event_print_t fn, void *priv) +bpf_perf_event_read_simple(void *mmap_mem, size_t mmap_size, size_t page_size, + void **copy_mem, size_t *copy_size, + bpf_perf_event_print_t fn, void *private_data) { - volatile struct perf_event_mmap_page *header = mem; + struct perf_event_mmap_page *header = mmap_mem; + __u64 data_head = ring_buffer_read_head(header); __u64 data_tail = header->data_tail; - __u64 data_head = header->data_head; - int ret = LIBBPF_PERF_EVENT_ERROR; - void *base, *begin, *end; - - asm volatile("" ::: "memory"); /* in real code it should be smp_rmb() */ - if (data_head == data_tail) - return LIBBPF_PERF_EVENT_CONT; - - base = ((char *)header) + page_size; - - begin = base + data_tail % size; - end = base + data_head % size; - - while (begin != end) { - struct perf_event_header *ehdr; - - ehdr = begin; - if (begin + ehdr->size > base + size) { - long len = base + size - begin; - - if (*buf_len < ehdr->size) { - free(*buf); - *buf = malloc(ehdr->size); - if (!*buf) { + void *base = ((__u8 *)header) + page_size; + int ret = LIBBPF_PERF_EVENT_CONT; + struct perf_event_header *ehdr; + size_t ehdr_size; + + while (data_head != data_tail) { + ehdr = base + (data_tail & (mmap_size - 1)); + ehdr_size = ehdr->size; + + if (((void *)ehdr) + ehdr_size > base + mmap_size) { + void *copy_start = ehdr; + size_t len_first = base + mmap_size - copy_start; + size_t len_secnd = ehdr_size - len_first; + + if (*copy_size < ehdr_size) { + free(*copy_mem); + *copy_mem = malloc(ehdr_size); + if (!*copy_mem) { + *copy_size = 0; ret = LIBBPF_PERF_EVENT_ERROR; break; } - *buf_len = ehdr->size; + *copy_size = ehdr_size; } - memcpy(*buf, begin, len); - memcpy(*buf + len, base, ehdr->size - len); - ehdr = (void *)*buf; - begin = base + ehdr->size - len; - } else if (begin + ehdr->size == base + size) { - begin = base; - } else { - begin += ehdr->size; + memcpy(*copy_mem, copy_start, len_first); + memcpy(*copy_mem + len_first, base, len_secnd); + ehdr = *copy_mem; } - ret = fn(ehdr, priv); + ret = fn(ehdr, private_data); + data_tail += ehdr_size; if (ret != LIBBPF_PERF_EVENT_CONT) break; - - data_tail += ehdr->size; } - __sync_synchronize(); /* smp_mb() */ - header->data_tail = data_tail; - + ring_buffer_write_tail(header, data_tail); return ret; } |