/* Reallocates 'b' so that it has exactly 'new_headroom' and 'new_tailroom'
* bytes of headroom and tailroom, respectively. */
static void
dp_packet_resize__(struct dp_packet *b, size_t new_headroom, size_t new_tailroom)
{
void *new_base, *new_data;
size_t new_allocated;
new_allocated = new_headroom + dp_packet_size(b) + new_tailroom;
switch (b->source) {
case DPBUF_DPDK:
OVS_NOT_REACHED();
case DPBUF_MALLOC:
if (new_headroom == dp_packet_headroom(b)) {
new_base = xrealloc(dp_packet_base(b), new_allocated);
} else {
new_base = xmalloc(new_allocated);
dp_packet_copy__(b, new_base, new_headroom, new_tailroom);
free(dp_packet_base(b));
}
break;
case DPBUF_STACK:
OVS_NOT_REACHED();
case DPBUF_STUB:
b->source = DPBUF_MALLOC;
new_base = xmalloc(new_allocated);
dp_packet_copy__(b, new_base, new_headroom, new_tailroom);
break;
default:
OVS_NOT_REACHED();
}
b->allocated = new_allocated;
dp_packet_set_base(b, new_base);
new_data = (char *) new_base + new_headroom;
if (dp_packet_data(b) != new_data) {
if (b->frame) {
uintptr_t data_delta = (char *) new_data - (char *) dp_packet_data(b);
b->frame = (char *) b->frame + data_delta;
}
dp_packet_set_data(b, new_data);
}
}
/* Returns the data in 'b' as a block of malloc()'d memory and frees the buffer
* within 'b'. (If 'b' itself was dynamically allocated, e.g. with
* dp_packet_new(), then it should still be freed with, e.g., dp_packet_delete().) */
void *
dp_packet_steal_data(struct dp_packet *b)
{
void *p;
ovs_assert(b->source != DPBUF_DPDK);
if (b->source == DPBUF_MALLOC && dp_packet_data(b) == dp_packet_base(b)) {
p = dp_packet_data(b);
} else {
p = xmemdup(dp_packet_data(b), dp_packet_size(b));
if (b->source == DPBUF_MALLOC) {
free(dp_packet_base(b));
}
}
dp_packet_set_base(b, NULL);
dp_packet_set_data(b, NULL);
return p;
}
static void
dp_packet_copy__(struct dp_packet *b, uint8_t *new_base,
size_t new_headroom, size_t new_tailroom)
{
const uint8_t *old_base = dp_packet_base(b);
size_t old_headroom = dp_packet_headroom(b);
size_t old_tailroom = dp_packet_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 + dp_packet_size(b) + copy_tailroom);
}
/* Frees memory that 'b' points to. */
void
dp_packet_uninit(struct dp_packet *b)
{
if (b) {
if (b->source == DPBUF_MALLOC) {
free(dp_packet_base(b));
} else if (b->source == DPBUF_DPDK) {
#ifdef DPDK_NETDEV
/* If this dp_packet was allocated by DPDK it must have been
* created as a dp_packet */
free_dpdk_buf((struct dp_packet*) b);
#endif
}
}
}
