/* Trims the size of 'b' to fit its actual content, reducing its tailroom to
* 0. Its headroom, if any, is preserved.
*
* Buffers not obtained from malloc() are not resized, since that wouldn't save
* any memory. */
void
ofpbuf_trim(struct ofpbuf *b)
{
if (b->source == OFPBUF_MALLOC
&& (ofpbuf_headroom(b) || ofpbuf_tailroom(b))) {
ofpbuf_resize__(b, 0, 0);
}
}
/* Reallocates 'b' so that it has exactly 'new_headroom' and 'new_tailroom'
* bytes of headroom and tailroom, respectively. */
static void
ofpbuf_resize__(struct ofpbuf *b, size_t new_headroom, size_t new_tailroom)
{
void *new_base, *new_data;
size_t new_allocated;
new_allocated = new_headroom + b->size + new_tailroom;
switch (b->source) {
case OFPBUF_MALLOC:
if (new_headroom == ofpbuf_headroom(b)) {
new_base = xrealloc(b->base, new_allocated);
} else {
new_base = xmalloc(new_allocated);
ofpbuf_copy__(b, new_base, new_headroom, new_tailroom);
free(b->base);
}
break;
case OFPBUF_STACK:
NOT_REACHED();
case OFPBUF_STUB:
b->source = OFPBUF_MALLOC;
new_base = xmalloc(new_allocated);
ofpbuf_copy__(b, new_base, new_headroom, new_tailroom);
break;
default:
NOT_REACHED();
}
b->allocated = new_allocated;
b->base = new_base;
new_data = (char *) new_base + new_headroom;
if (b->data != new_data) {
uintptr_t data_delta = (char *) new_data - (char *) b->data;
b->data = new_data;
if (b->l2) {
b->l2 = (char *) b->l2 + data_delta;
}
if (b->l2_5) {
b->l2_5 = (char *) b->l2_5 + data_delta;
}
if (b->l3) {
b->l3 = (char *) b->l3 + data_delta;
}
if (b->l4) {
b->l4 = (char *) b->l4 + data_delta;
}
if (b->l7) {
b->l7 = (char *) b->l7 + data_delta;
}
}
}
/* Returns a string that describes some of 'b''s metadata plus a hex dump of up
* to 'maxbytes' from the start of the buffer. */
char *
ofpbuf_to_string(const struct ofpbuf *b, size_t maxbytes)
{
struct ds s;
ds_init(&s);
ds_put_format(&s, "size=%"PRIu32", allocated=%"PRIu32", head=%"PRIuSIZE", tail=%"PRIuSIZE"\n",
b->size, b->allocated,
ofpbuf_headroom(b), ofpbuf_tailroom(b));
ds_put_hex_dump(&s, b->data, MIN(b->size, maxbytes), 0, false);
return ds_cstr(&s);
}
/* Shifts all of the data within the allocated space in 'b' by 'delta' bytes.
* For example, a 'delta' of 1 would cause each byte of data to move one byte
* forward (from address 'p' to 'p+1'), and a 'delta' of -1 would cause each
* byte to move one byte backward (from 'p' to 'p-1').
*
* If used, user must make sure the 'header' and 'msg' pointers are updated
* after shifting.
*/
void
ofpbuf_shift(struct ofpbuf *b, int delta)
{
ovs_assert(delta > 0 ? delta <= ofpbuf_tailroom(b)
: delta < 0 ? -delta <= ofpbuf_headroom(b)
: true);
if (delta != 0) {
char *dst = (char *) b->data + delta;
memmove(dst, b->data, b->size);
b->data = dst;
}
}
/* Shifts all of the data within the allocated space in 'b' by 'delta' bytes.
* For example, a 'delta' of 1 would cause each byte of data to move one byte
* forward (from address 'p' to 'p+1'), and a 'delta' of -1 would cause each
* byte to move one byte backward (from 'p' to 'p-1'). */
void
ofpbuf_shift(struct ofpbuf *b, int delta)
{
ovs_assert(delta > 0 ? delta <= ofpbuf_tailroom(b)
: delta < 0 ? -delta <= ofpbuf_headroom(b)
: true);
if (delta != 0) {
char *dst = (char *) ofpbuf_data(b) + delta;
memmove(dst, ofpbuf_data(b), ofpbuf_size(b));
ofpbuf_set_data(b, dst);
}
}
/* Reallocates 'b' so that it has exactly 'new_headroom' and 'new_tailroom'
* bytes of headroom and tailroom, respectively. */
static void
ofpbuf_resize__(struct ofpbuf *b, size_t new_headroom, size_t new_tailroom)
{
void *new_base, *new_data;
size_t new_allocated;
new_allocated = new_headroom + b->size + new_tailroom;
switch (b->source) {
case OFPBUF_MALLOC:
if (new_headroom == ofpbuf_headroom(b)) {
new_base = xrealloc(b->base, new_allocated);
} else {
new_base = xmalloc(new_allocated);
ofpbuf_copy__(b, new_base, new_headroom, new_tailroom);
free(b->base);
}
break;
case OFPBUF_STACK:
OVS_NOT_REACHED();
case OFPBUF_STUB:
b->source = OFPBUF_MALLOC;
new_base = xmalloc(new_allocated);
ofpbuf_copy__(b, new_base, new_headroom, new_tailroom);
break;
default:
OVS_NOT_REACHED();
}
b->allocated = new_allocated;
b->base = new_base;
new_data = (char *) new_base + new_headroom;
if (b->data != new_data) {
if (b->header) {
uintptr_t data_delta = (char *) b->header - (char *) b->data;
b->header = (char *) new_data + data_delta;
}
if (b->msg) {
uintptr_t data_delta = (char *) b->msg - (char *) b->data;
b->msg = (char *) new_data + data_delta;
}
b->data = new_data;
}
}
static void
ofpbuf_copy__(struct ofpbuf *b, uint8_t *new_base,
size_t new_headroom, size_t new_tailroom)
{
const uint8_t *old_base = b->base;
size_t old_headroom = ofpbuf_headroom(b);
size_t old_tailroom = ofpbuf_tailroom(b);
size_t copy_headroom = MIN(old_headroom, new_headroom);
size_t copy_tailroom = MIN(old_tailroom, new_tailroom);
memcpy(&new_base[new_headroom - copy_headroom],
&old_base[old_headroom - copy_headroom],
copy_headroom + b->size + copy_tailroom);
}
/* Reallocates 'b' so that it has exactly 'new_headroom' and 'new_tailroom'
* bytes of headroom and tailroom, respectively. */
static void
ofpbuf_resize__(struct ofpbuf *b, size_t new_headroom, size_t new_tailroom)
{
void *new_base, *new_data;
size_t new_allocated;
new_allocated = new_headroom + ofpbuf_size(b) + new_tailroom;
switch (b->source) {
case OFPBUF_DPDK:
OVS_NOT_REACHED();
case OFPBUF_MALLOC:
if (new_headroom == ofpbuf_headroom(b)) {
new_base = xrealloc(ofpbuf_base(b), new_allocated);
} else {
new_base = xmalloc(new_allocated);
ofpbuf_copy__(b, new_base, new_headroom, new_tailroom);
free(ofpbuf_base(b));
}
break;
case OFPBUF_STACK:
OVS_NOT_REACHED();
case OFPBUF_STUB:
b->source = OFPBUF_MALLOC;
new_base = xmalloc(new_allocated);
ofpbuf_copy__(b, new_base, new_headroom, new_tailroom);
break;
default:
OVS_NOT_REACHED();
}
b->allocated = new_allocated;
ofpbuf_set_base(b, new_base);
new_data = (char *) new_base + new_headroom;
if (ofpbuf_data(b) != new_data) {
if (b->frame) {
uintptr_t data_delta = (char *) new_data - (char *) ofpbuf_data(b);
b->frame = (char *) b->frame + data_delta;
}
ofpbuf_set_data(b, new_data);
}
}
void
ofpbuf_prealloc_headroom(struct ofpbuf *b, size_t size)
{
assert(size <= ofpbuf_headroom(b));
}
/* Reallocates 'b' so that it has exactly 'new_tailroom' bytes of tailroom. */
static void
ofpbuf_resize_tailroom__(struct ofpbuf *b, size_t new_tailroom)
{
b->allocated = ofpbuf_headroom(b) + b->size + new_tailroom;
ofpbuf_rebase__(b, xrealloc(b->base, b->allocated));
}