nghttp2/lib/spdylay_frame.c

720 lines
20 KiB
C

/*
* Spdylay - SPDY Library
*
* Copyright (c) 2012 Tatsuhiro Tsujikawa
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
* LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
* OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
#include "spdylay_frame.h"
#include <arpa/inet.h>
#include <string.h>
#include <assert.h>
#include <stdio.h>
#include "spdylay_helper.h"
static uint8_t spdylay_unpack_pri(const uint8_t *data)
{
return (data[0] >> 6) & 0x3;
}
static uint8_t* spdylay_pack_str(uint8_t *buf, const char *str, size_t len)
{
spdylay_put_uint16be(buf, len);
buf += 2;
memcpy(buf, str, len);
return buf+len;
}
static void spdylay_frame_pack_ctrl_hd(uint8_t* buf, const spdylay_ctrl_hd *hd)
{
spdylay_put_uint16be(&buf[0], hd->version);
buf[0] |= 1 << 7;
spdylay_put_uint16be(&buf[2], hd->type);
spdylay_put_uint32be(&buf[4], hd->length);
buf[4] = hd->flags;
}
static void spdylay_frame_unpack_ctrl_hd(spdylay_ctrl_hd *hd,
const uint8_t* buf)
{
hd->version = spdylay_get_uint16(buf) & SPDYLAY_VERSION_MASK;
hd->type = spdylay_get_uint16(&buf[2]);
hd->flags = buf[4];
hd->length = spdylay_get_uint32(&buf[4]) & SPDYLAY_LENGTH_MASK;
}
static ssize_t spdylay_frame_alloc_pack_nv(uint8_t **buf_ptr,
char **nv, size_t nv_offset,
spdylay_zlib *deflater)
{
size_t nvbuflen = spdylay_frame_count_nv_space(nv);
uint8_t *nvbuf = malloc(nvbuflen);
size_t maxframelen = nv_offset+
spdylay_zlib_deflate_hd_bound(deflater, nvbuflen);
uint8_t *framebuf = malloc(maxframelen);
ssize_t framelen;
spdylay_frame_pack_nv(nvbuf, nv);
framelen = spdylay_zlib_deflate_hd(deflater,
framebuf+nv_offset,
maxframelen-nv_offset,
nvbuf, nvbuflen);
free(nvbuf);
if(framelen < 0) {
free(framebuf);
return framelen;
}
framelen += nv_offset;
*buf_ptr = framebuf;
return framelen;
}
int spdylay_frame_count_unpack_nv_space
(size_t *nvlen_ptr, size_t *buflen_ptr, const uint8_t *in, size_t inlen)
{
uint16_t n;
size_t buflen = 0;
size_t nvlen = 0;
size_t off = 0;
const size_t len_size = sizeof(uint16_t);
int i;
if(inlen < len_size) {
return SPDYLAY_ERR_INVALID_ARGUMENT;
}
n = spdylay_get_uint16(in);
off += len_size;
for(i = 0; i < n; ++i) {
uint16_t len;
int j;
for(j = 0; j < 2; ++j) {
if(inlen-off < len_size) {
return SPDYLAY_ERR_INVALID_ARGUMENT;
}
len = spdylay_get_uint16(in+off);
off += 2;
if(inlen-off < len) {
return SPDYLAY_ERR_INVALID_ARGUMENT;
}
buflen += len+1;
off += len;
}
for(off -= len, j = off+len; off != j; ++off) {
if(in[off] == '\0') {
++nvlen;
}
}
++nvlen;
}
*nvlen_ptr = nvlen;
*buflen_ptr = buflen+(nvlen*2+1)*sizeof(char*);
return 0;
}
int spdylay_frame_unpack_nv(char ***nv_ptr, const uint8_t *in, size_t inlen)
{
size_t nvlen, buflen;
int r, i;
char *buf, **index, *data;
uint16_t n;
r = spdylay_frame_count_unpack_nv_space(&nvlen, &buflen, in, inlen);
if(r != 0) {
return r;
}
buf = malloc(buflen);
if(buf == NULL) {
return SPDYLAY_ERR_NOMEM;
}
index = (char**)buf;
data = buf+(nvlen*2+1)*sizeof(char*);
n = spdylay_get_uint16(in);
in += 2;
for(i = 0; i < n; ++i) {
uint16_t len;
char *name, *val;
char *stop;
len = spdylay_get_uint16(in);
in += 2;
name = data;
memcpy(data, in, len);
data += len;
*data = '\0';
++data;
in += len;
len = spdylay_get_uint16(in);
in += 2;
val = data;
memcpy(data, in, len);
for(stop = data+len; data != stop; ++data) {
if(*data == '\0') {
*index++ = name;
*index++ = val;
val = data+1;
}
}
*data = '\0';
++data;
in += len;
*index++ = name;
*index++ = val;
}
*index = NULL;
assert((char*)index-buf == (nvlen*2)*sizeof(char*));
*nv_ptr = (char**)buf;
return 0;
}
static int spdylay_frame_alloc_unpack_nv(char ***nv_ptr,
const uint8_t *in, size_t inlen,
spdylay_zlib *inflater)
{
ssize_t r;
spdylay_buffer outbuffer;
spdylay_buffer_init(&outbuffer, 4096);
r = spdylay_zlib_inflate_hd(inflater, &outbuffer, in, inlen);
if(r < 0) {
spdylay_buffer_free(&outbuffer);
return r;
} else {
uint8_t *buf = malloc(r);
if(buf == NULL) {
spdylay_buffer_free(&outbuffer);
return SPDYLAY_ERR_NOMEM;
}
spdylay_buffer_serialize(&outbuffer, buf);
spdylay_buffer_free(&outbuffer);
r = spdylay_frame_unpack_nv(nv_ptr, buf, r);
free(buf);
return r;
}
}
size_t spdylay_frame_count_nv_space(char **nv)
{
size_t sum = 2;
int i;
const char *prev = "";
size_t prevlen = 0;
for(i = 0; nv[i]; i += 2) {
const char *key = nv[i];
const char *val = nv[i+1];
size_t keylen = strlen(key);
size_t vallen = strlen(val);
if(prevlen == keylen && memcmp(prev, key, keylen) == 0) {
/* Join previous value, with NULL character */
sum += vallen+1;
} else {
prev = key;
/* SPDY NV header does not include terminating NULL byte */
sum += keylen+vallen+4;
}
}
return sum;
}
ssize_t spdylay_frame_pack_nv(uint8_t *buf, char **nv)
{
int i;
uint8_t *bufp = buf+2;
uint16_t num_nv = 0;
/* TODO Join values with same keys, using '\0' as a delimiter */
const char *prev = "";
uint8_t *prev_vallen_buf = NULL;
uint16_t prev_vallen = 0;
for(i = 0; nv[i]; i += 2) {
const char *key = nv[i];
const char *val = nv[i+1];
size_t keylen = strlen(key);
size_t vallen = strlen(val);
if(strcmp(prev, key) == 0) {
prev_vallen += vallen+1;
spdylay_put_uint16be(prev_vallen_buf, prev_vallen);
*bufp = '\0';
++bufp;
memcpy(bufp, val, vallen);
bufp += vallen;
} else {
++num_nv;
bufp = spdylay_pack_str(bufp, key, keylen);
prev = key;
prev_vallen_buf = bufp;
prev_vallen = vallen;
bufp = spdylay_pack_str(bufp, val, vallen);
}
}
spdylay_put_uint16be(buf, num_nv);
return bufp-buf;
}
int spdylay_frame_is_ctrl_frame(uint8_t first_byte)
{
return first_byte & 0x80;
}
void spdylay_frame_nv_del(char **nv)
{
free(nv);
}
char** spdylay_frame_nv_copy(const char **nv)
{
int i;
char *buf;
char **index, *data;
size_t buflen = 0;
for(i = 0; nv[i]; ++i) {
buflen += strlen(nv[i])+1;
}
buflen += (i+1)*sizeof(char*);
buf = malloc(buflen);
if(buf == NULL) {
return NULL;
}
index = (char**)buf;
data = buf+(i+1)*sizeof(char*);
for(i = 0; nv[i]; ++i) {
size_t len = strlen(nv[i])+1;
memcpy(data, nv[i], len);
*index++ = data;
data += len;
}
*index = NULL;
return (char**)buf;
}
static int spdylay_string_compar(const void *lhs, const void *rhs)
{
return strcmp(*(char **)lhs, *(char **)rhs);
}
void spdylay_frame_nv_sort(char **nv)
{
int n;
for(n = 0; nv[n]; ++n);
qsort(nv, n/2, 2*sizeof(char*), spdylay_string_compar);
}
void spdylay_frame_syn_stream_init(spdylay_syn_stream *frame, uint8_t flags,
int32_t stream_id, int32_t assoc_stream_id,
uint8_t pri, char **nv)
{
memset(frame, 0, sizeof(spdylay_syn_stream));
frame->hd.version = SPDYLAY_PROTO_VERSION;
frame->hd.type = SPDYLAY_SYN_STREAM;
frame->hd.flags = flags;
frame->stream_id = stream_id;
frame->assoc_stream_id = assoc_stream_id;
frame->pri = pri;
frame->nv = nv;
}
void spdylay_frame_syn_stream_free(spdylay_syn_stream *frame)
{
spdylay_frame_nv_del(frame->nv);
}
void spdylay_frame_syn_reply_init(spdylay_syn_reply *frame, uint8_t flags,
int32_t stream_id, char **nv)
{
memset(frame, 0, sizeof(spdylay_syn_reply));
frame->hd.version = SPDYLAY_PROTO_VERSION;
frame->hd.type = SPDYLAY_SYN_REPLY;
frame->hd.flags = flags;
frame->stream_id = stream_id;
frame->nv = nv;
}
void spdylay_frame_syn_reply_free(spdylay_syn_reply *frame)
{
spdylay_frame_nv_del(frame->nv);
}
void spdylay_frame_ping_init(spdylay_ping *frame, uint32_t unique_id)
{
memset(frame, 0, sizeof(spdylay_ping));
frame->hd.version = SPDYLAY_PROTO_VERSION;
frame->hd.type = SPDYLAY_PING;
frame->hd.flags = SPDYLAY_FLAG_NONE;
frame->hd.length = 4;
frame->unique_id = unique_id;
}
void spdylay_frame_ping_free(spdylay_ping *frame)
{}
void spdylay_frame_goaway_init(spdylay_goaway *frame,
int32_t last_good_stream_id)
{
memset(frame, 0, sizeof(spdylay_goaway));
frame->hd.version = SPDYLAY_PROTO_VERSION;
frame->hd.type = SPDYLAY_GOAWAY;
frame->hd.length = 4;
frame->last_good_stream_id = last_good_stream_id;
}
void spdylay_frame_goaway_free(spdylay_goaway *frame)
{}
void spdylay_frame_headers_init(spdylay_headers *frame, uint8_t flags,
int32_t stream_id, char **nv)
{
memset(frame, 0, sizeof(spdylay_headers));
frame->hd.version = SPDYLAY_PROTO_VERSION;
frame->hd.type = SPDYLAY_HEADERS;
frame->hd.flags = flags;
frame->stream_id = stream_id;
frame->nv = nv;
}
void spdylay_frame_headers_free(spdylay_headers *frame)
{
spdylay_frame_nv_del(frame->nv);
}
void spdylay_frame_rst_stream_init(spdylay_rst_stream *frame,
int32_t stream_id, uint32_t status_code)
{
memset(frame, 0, sizeof(spdylay_rst_stream));
frame->hd.version = SPDYLAY_PROTO_VERSION;
frame->hd.type = SPDYLAY_RST_STREAM;
frame->hd.flags = 0;
frame->hd.length = 8;
frame->stream_id = stream_id;
frame->status_code = status_code;
}
void spdylay_frame_rst_stream_free(spdylay_rst_stream *frame)
{}
void spdylay_frame_settings_init(spdylay_settings *frame, uint8_t flags,
spdylay_settings_entry *iv, size_t niv)
{
memset(frame, 0, sizeof(spdylay_settings));
frame->hd.version = SPDYLAY_PROTO_VERSION;
frame->hd.type = SPDYLAY_SETTINGS;
frame->hd.flags = flags;
frame->hd.length = 4+niv*8;
frame->niv = niv;
frame->iv = iv;
}
void spdylay_frame_settings_free(spdylay_settings *frame)
{
free(frame->iv);
}
void spdylay_frame_data_init(spdylay_data *frame, int32_t stream_id,
spdylay_data_provider *data_prd)
{
memset(frame, 0, sizeof(spdylay_data));
frame->stream_id = stream_id;
frame->data_prd = *data_prd;
}
void spdylay_frame_data_free(spdylay_data *frame)
{}
#define SPDYLAY_SYN_STREAM_NV_OFFSET 18
ssize_t spdylay_frame_pack_syn_stream(uint8_t **buf_ptr,
spdylay_syn_stream *frame,
spdylay_zlib *deflater)
{
uint8_t *framebuf = NULL;
ssize_t framelen;
framelen = spdylay_frame_alloc_pack_nv(&framebuf, frame->nv,
SPDYLAY_SYN_STREAM_NV_OFFSET,
deflater);
if(framelen < 0) {
return framelen;
}
frame->hd.length = framelen-SPDYLAY_FRAME_HEAD_LENGTH;
memset(framebuf, 0, SPDYLAY_SYN_STREAM_NV_OFFSET);
/* pack ctrl header after length is determined */
spdylay_frame_pack_ctrl_hd(framebuf, &frame->hd);
spdylay_put_uint32be(&framebuf[8], frame->stream_id);
spdylay_put_uint32be(&framebuf[12], frame->assoc_stream_id);
framebuf[16] = (frame->pri << 6);
*buf_ptr = framebuf;
return framelen;
}
int spdylay_frame_unpack_syn_stream(spdylay_syn_stream *frame,
const uint8_t *head, size_t headlen,
const uint8_t *payload, size_t payloadlen,
spdylay_zlib *inflater)
{
int r;
if(payloadlen < 12) {
return SPDYLAY_ERR_INVALID_FRAME;
}
spdylay_frame_unpack_ctrl_hd(&frame->hd, head);
frame->stream_id = spdylay_get_uint32(payload) & SPDYLAY_STREAM_ID_MASK;
frame->assoc_stream_id =
spdylay_get_uint32(payload+4) & SPDYLAY_STREAM_ID_MASK;
frame->pri = spdylay_unpack_pri(payload+8);
r = spdylay_frame_alloc_unpack_nv(&frame->nv, payload+10, payloadlen-10,
inflater);
return r;
}
#define SPDYLAY_SYN_REPLY_NV_OFFSET 14
ssize_t spdylay_frame_pack_syn_reply(uint8_t **buf_ptr,
spdylay_syn_reply *frame,
spdylay_zlib *deflater)
{
uint8_t *framebuf = NULL;
ssize_t framelen;
framelen = spdylay_frame_alloc_pack_nv(&framebuf, frame->nv,
SPDYLAY_SYN_REPLY_NV_OFFSET, deflater);
if(framelen < 0) {
return framelen;
}
frame->hd.length = framelen-SPDYLAY_FRAME_HEAD_LENGTH;
memset(framebuf, 0, SPDYLAY_SYN_REPLY_NV_OFFSET);
spdylay_frame_pack_ctrl_hd(framebuf, &frame->hd);
spdylay_put_uint32be(&framebuf[8], frame->stream_id);
*buf_ptr = framebuf;
return framelen;
}
int spdylay_frame_unpack_syn_reply(spdylay_syn_reply *frame,
const uint8_t *head, size_t headlen,
const uint8_t *payload, size_t payloadlen,
spdylay_zlib *inflater)
{
int r;
if(payloadlen < 8) {
return SPDYLAY_ERR_INVALID_FRAME;
}
spdylay_frame_unpack_ctrl_hd(&frame->hd, head);
frame->stream_id = spdylay_get_uint32(payload) & SPDYLAY_STREAM_ID_MASK;
r = spdylay_frame_alloc_unpack_nv(&frame->nv, payload+6, payloadlen-6,
inflater);
return r;
}
ssize_t spdylay_frame_pack_ping(uint8_t **buf_ptr, spdylay_ping *frame)
{
uint8_t *framebuf = NULL;
ssize_t framelen = 12;
framebuf = malloc(framelen);
if(framebuf == NULL) {
return SPDYLAY_ERR_NOMEM;
}
memset(framebuf, 0, framelen);
spdylay_frame_pack_ctrl_hd(framebuf, &frame->hd);
spdylay_put_uint32be(&framebuf[8], frame->unique_id);
*buf_ptr = framebuf;
return framelen;
}
int spdylay_frame_unpack_ping(spdylay_ping *frame,
const uint8_t *head, size_t headlen,
const uint8_t *payload, size_t payloadlen)
{
if(payloadlen < 4) {
return SPDYLAY_ERR_INVALID_FRAME;
}
spdylay_frame_unpack_ctrl_hd(&frame->hd, head);
frame->unique_id = spdylay_get_uint32(payload);
return 0;
}
ssize_t spdylay_frame_pack_goaway(uint8_t **buf_ptr, spdylay_goaway *frame)
{
uint8_t *framebuf = NULL;
ssize_t framelen = 12;
framebuf = malloc(framelen);
if(framebuf == NULL) {
return SPDYLAY_ERR_NOMEM;
}
memset(framebuf, 0, framelen);
spdylay_frame_pack_ctrl_hd(framebuf, &frame->hd);
spdylay_put_uint32be(&framebuf[8], frame->last_good_stream_id);
*buf_ptr = framebuf;
return framelen;
}
int spdylay_frame_unpack_goaway(spdylay_goaway *frame,
const uint8_t *head, size_t headlen,
const uint8_t *payload, size_t payloadlen)
{
if(payloadlen < 4) {
return SPDYLAY_ERR_INVALID_FRAME;
}
spdylay_frame_unpack_ctrl_hd(&frame->hd, head);
frame->last_good_stream_id = spdylay_get_uint32(payload) &
SPDYLAY_STREAM_ID_MASK;
return 0;
}
#define SPDYLAY_HEADERS_NV_OFFSET 14
ssize_t spdylay_frame_pack_headers(uint8_t **buf_ptr,
spdylay_headers *frame,
spdylay_zlib *deflater)
{
uint8_t *framebuf = NULL;
ssize_t framelen;
framelen = spdylay_frame_alloc_pack_nv(&framebuf, frame->nv,
SPDYLAY_HEADERS_NV_OFFSET, deflater);
if(framelen < 0) {
return framelen;
}
frame->hd.length = framelen-SPDYLAY_FRAME_HEAD_LENGTH;
memset(framebuf, 0, SPDYLAY_HEADERS_NV_OFFSET);
spdylay_frame_pack_ctrl_hd(framebuf, &frame->hd);
spdylay_put_uint32be(&framebuf[8], frame->stream_id);
*buf_ptr = framebuf;
return framelen;
}
int spdylay_frame_unpack_headers(spdylay_headers *frame,
const uint8_t *head, size_t headlen,
const uint8_t *payload, size_t payloadlen,
spdylay_zlib *inflater)
{
int r;
if(payloadlen < 8) {
return SPDYLAY_ERR_INVALID_FRAME;
}
spdylay_frame_unpack_ctrl_hd(&frame->hd, head);
frame->stream_id = spdylay_get_uint32(payload) & SPDYLAY_STREAM_ID_MASK;
r = spdylay_frame_alloc_unpack_nv(&frame->nv, payload+6, payloadlen-6,
inflater);
return r;
}
ssize_t spdylay_frame_pack_rst_stream(uint8_t **buf_ptr,
spdylay_rst_stream *frame)
{
uint8_t *framebuf;
ssize_t framelen = 16;
framebuf = malloc(framelen);
if(framebuf == NULL) {
return SPDYLAY_ERR_NOMEM;
}
memset(framebuf, 0, framelen);
spdylay_frame_pack_ctrl_hd(framebuf, &frame->hd);
spdylay_put_uint32be(&framebuf[8], frame->stream_id);
spdylay_put_uint32be(&framebuf[12], frame->status_code);
*buf_ptr = framebuf;
return framelen;
}
int spdylay_frame_unpack_rst_stream(spdylay_rst_stream *frame,
const uint8_t *head, size_t headlen,
const uint8_t *payload, size_t payloadlen)
{
if(payloadlen < 8) {
return SPDYLAY_ERR_INVALID_FRAME;
}
spdylay_frame_unpack_ctrl_hd(&frame->hd, head);
frame->stream_id = spdylay_get_uint32(payload) & SPDYLAY_STREAM_ID_MASK;
frame->status_code = spdylay_get_uint32(payload+4);
return 0;
}
ssize_t spdylay_frame_pack_settings(uint8_t **buf_ptr, spdylay_settings *frame)
{
uint8_t *framebuf;
ssize_t framelen = SPDYLAY_FRAME_HEAD_LENGTH+frame->hd.length;
int i;
framebuf = malloc(framelen);
if(framebuf == NULL) {
return SPDYLAY_ERR_NOMEM;
}
memset(framebuf, 0, framelen);
spdylay_frame_pack_ctrl_hd(framebuf, &frame->hd);
spdylay_put_uint32be(&framebuf[8], frame->niv);
for(i = 0; i < frame->niv; ++i) {
int off = i*8;
/* spdy/2 spec says ID is network byte order, but publicly
deployed server sends little endian host byte order. */
char *id_ptr = (char*)(&frame->iv[i].settings_id);
#ifdef WORDS_BIGENDIAN
framebuf[12+off] = id_ptr[3];
framebuf[12+off+1] = id_ptr[2];
framebuf[12+off+2] = id_ptr[1];
#else /* !WORDS_BIGENDIAN */
memcpy(&framebuf[12+off], id_ptr, 3);
#endif /* !WORDS_BIGENDIAN */
framebuf[15+off] = frame->iv[i].flags;
spdylay_put_uint32be(&framebuf[16+off], frame->iv[i].value);
}
*buf_ptr = framebuf;
return framelen;
}
int spdylay_frame_unpack_settings(spdylay_settings *frame,
const uint8_t *head, size_t headlen,
const uint8_t *payload, size_t payloadlen)
{
int i;
if(payloadlen < 4) {
return SPDYLAY_ERR_INVALID_FRAME;
}
spdylay_frame_unpack_ctrl_hd(&frame->hd, head);
frame->niv = spdylay_get_uint32(payload);
if(payloadlen != 4+frame->niv*8) {
return SPDYLAY_ERR_INVALID_FRAME;
}
frame->iv = malloc(frame->niv*sizeof(spdylay_settings_entry));
if(frame->iv == NULL) {
return SPDYLAY_ERR_NOMEM;
}
for(i = 0; i < frame->niv; ++i) {
int off = i*8;
/* ID is little endian. See comments in
spdylay_frame_pack_settings(). */
frame->iv[i].settings_id = 0;
#ifdef WORDS_BIGENDIAN
*(char*)(&frame->iv[i].settings_id[1]) = &payload[4+off+2];
*(char*)(&frame->iv[i].settings_id[2]) = &payload[4+off+1];
*(char*)(&frame->iv[i].settings_id[3]) = &payload[4+off+0];
#else /* !WORDS_BIGENDIAN */
memcpy(&frame->iv[i].settings_id, &payload[4+off], 3);
#endif /* !WORDS_BIGENDIAN */
frame->iv[i].flags = payload[7+off];
frame->iv[i].value = spdylay_get_uint32(&payload[8+off]);
}
return 0;
}
spdylay_settings_entry* spdylay_frame_iv_copy(const spdylay_settings_entry *iv,
size_t niv)
{
spdylay_settings_entry *iv_copy;
size_t len = niv*sizeof(spdylay_settings_entry);
iv_copy = malloc(len);
if(iv_copy == NULL) {
return NULL;
}
memcpy(iv_copy, iv, len);
return iv_copy;
}