blob: 5332fc4f36f674160a2ed97266123355a9541ae1 [file] [log] [blame]
/*
* Software in this file is based heavily on code written in the FreeBSD source
* code repostiory. While the code is written from scratch, it contains
* many of the ideas and logic flow in the original source, this is a
* derivative work, and the following license applies as well:
*
* Copyright (c) 1982, 1986, 1988, 1991, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
*/
#include <assert.h>
#include <string.h>
#include <limits.h>
#include "syscfg/syscfg.h"
#if !MYNEWT_VAL(OS_SYSVIEW_TRACE_MBUF)
#define OS_TRACE_DISABLE_FILE_API
#endif
#include "os/mynewt.h"
/**
* @addtogroup OSKernel
* @{
* @defgroup OSMqueue Queue of Mbufs
* @{
*/
STAILQ_HEAD(, os_mbuf_pool) g_msys_pool_list =
STAILQ_HEAD_INITIALIZER(g_msys_pool_list);
int
os_mqueue_init(struct os_mqueue *mq, os_event_fn *ev_cb, void *arg)
{
struct os_event *ev;
STAILQ_INIT(&mq->mq_head);
ev = &mq->mq_ev;
memset(ev, 0, sizeof(*ev));
ev->ev_cb = ev_cb;
ev->ev_arg = arg;
return (0);
}
struct os_mbuf *
os_mqueue_get(struct os_mqueue *mq)
{
struct os_mbuf_pkthdr *mp;
struct os_mbuf *m;
os_sr_t sr;
OS_ENTER_CRITICAL(sr);
mp = STAILQ_FIRST(&mq->mq_head);
if (mp) {
STAILQ_REMOVE_HEAD(&mq->mq_head, omp_next);
}
OS_EXIT_CRITICAL(sr);
if (mp) {
m = OS_MBUF_PKTHDR_TO_MBUF(mp);
} else {
m = NULL;
}
return (m);
}
int
os_mqueue_put(struct os_mqueue *mq, struct os_eventq *evq, struct os_mbuf *m)
{
struct os_mbuf_pkthdr *mp;
os_sr_t sr;
int rc;
/* Can only place the head of a chained mbuf on the queue. */
if (!OS_MBUF_IS_PKTHDR(m)) {
rc = OS_EINVAL;
goto err;
}
mp = OS_MBUF_PKTHDR(m);
OS_ENTER_CRITICAL(sr);
STAILQ_INSERT_TAIL(&mq->mq_head, mp, omp_next);
OS_EXIT_CRITICAL(sr);
/* Only post an event to the queue if its specified */
if (evq) {
os_eventq_put(evq, &mq->mq_ev);
}
return (0);
err:
return (rc);
}
int
os_msys_register(struct os_mbuf_pool *new_pool)
{
struct os_mbuf_pool *pool;
pool = NULL;
STAILQ_FOREACH(pool, &g_msys_pool_list, omp_next) {
if (new_pool->omp_databuf_len > pool->omp_databuf_len) {
break;
}
}
if (pool) {
STAILQ_INSERT_AFTER(&g_msys_pool_list, pool, new_pool, omp_next);
} else {
STAILQ_INSERT_TAIL(&g_msys_pool_list, new_pool, omp_next);
}
return (0);
}
void
os_msys_reset(void)
{
STAILQ_INIT(&g_msys_pool_list);
}
static struct os_mbuf_pool *
_os_msys_find_pool(uint16_t dsize)
{
struct os_mbuf_pool *pool;
pool = NULL;
STAILQ_FOREACH(pool, &g_msys_pool_list, omp_next) {
if (dsize <= pool->omp_databuf_len) {
break;
}
}
if (!pool) {
pool = STAILQ_LAST(&g_msys_pool_list, os_mbuf_pool, omp_next);
}
return (pool);
}
struct os_mbuf *
os_msys_get(uint16_t dsize, uint16_t leadingspace)
{
struct os_mbuf *m;
struct os_mbuf_pool *pool;
pool = _os_msys_find_pool(dsize);
if (!pool) {
goto err;
}
m = os_mbuf_get(pool, leadingspace);
return (m);
err:
return (NULL);
}
struct os_mbuf *
os_msys_get_pkthdr(uint16_t dsize, uint16_t user_hdr_len)
{
uint16_t total_pkthdr_len;
struct os_mbuf *m;
struct os_mbuf_pool *pool;
total_pkthdr_len = user_hdr_len + sizeof(struct os_mbuf_pkthdr);
pool = _os_msys_find_pool(dsize + total_pkthdr_len);
if (!pool) {
goto err;
}
m = os_mbuf_get_pkthdr(pool, user_hdr_len);
return (m);
err:
return (NULL);
}
int
os_msys_count(void)
{
struct os_mbuf_pool *omp;
int total;
total = 0;
STAILQ_FOREACH(omp, &g_msys_pool_list, omp_next) {
total += omp->omp_pool->mp_num_blocks;
}
return total;
}
int
os_msys_num_free(void)
{
struct os_mbuf_pool *omp;
int total;
total = 0;
STAILQ_FOREACH(omp, &g_msys_pool_list, omp_next) {
total += omp->omp_pool->mp_num_free;
}
return total;
}
int
os_mbuf_pool_init(struct os_mbuf_pool *omp, struct os_mempool *mp,
uint16_t buf_len, uint16_t nbufs)
{
omp->omp_databuf_len = buf_len - sizeof(struct os_mbuf);
omp->omp_pool = mp;
return (0);
}
struct os_mbuf *
os_mbuf_get(struct os_mbuf_pool *omp, uint16_t leadingspace)
{
struct os_mbuf *om;
os_trace_api_u32x2(OS_TRACE_ID_MBUF_GET, (uint32_t)omp,
(uint32_t)leadingspace);
if (leadingspace > omp->omp_databuf_len) {
om = NULL;
goto done;
}
om = os_memblock_get(omp->omp_pool);
if (!om) {
goto done;
}
SLIST_NEXT(om, om_next) = NULL;
om->om_flags = 0;
om->om_pkthdr_len = 0;
om->om_len = 0;
om->om_data = (&om->om_databuf[0] + leadingspace);
om->om_omp = omp;
done:
os_trace_api_ret_u32(OS_TRACE_ID_MBUF_GET, (uint32_t)om);
return om;
}
struct os_mbuf *
os_mbuf_get_pkthdr(struct os_mbuf_pool *omp, uint8_t user_pkthdr_len)
{
uint16_t pkthdr_len;
struct os_mbuf_pkthdr *pkthdr;
struct os_mbuf *om;
os_trace_api_u32x2(OS_TRACE_ID_MBUF_GET_PKTHDR, (uint32_t)omp,
(uint32_t)user_pkthdr_len);
/* User packet header must fit inside mbuf */
pkthdr_len = user_pkthdr_len + sizeof(struct os_mbuf_pkthdr);
if ((pkthdr_len > omp->omp_databuf_len) || (pkthdr_len > 255)) {
om = NULL;
goto done;
}
om = os_mbuf_get(omp, 0);
if (om) {
om->om_pkthdr_len = pkthdr_len;
om->om_data += pkthdr_len;
pkthdr = OS_MBUF_PKTHDR(om);
pkthdr->omp_len = 0;
pkthdr->omp_flags = 0;
STAILQ_NEXT(pkthdr, omp_next) = NULL;
}
done:
os_trace_api_ret_u32(OS_TRACE_ID_MBUF_GET_PKTHDR, (uint32_t)om);
return om;
}
int
os_mbuf_free(struct os_mbuf *om)
{
int rc;
os_trace_api_u32(OS_TRACE_ID_MBUF_FREE, (uint32_t)om);
if (om->om_omp != NULL) {
rc = os_memblock_put(om->om_omp->omp_pool, om);
if (rc != 0) {
goto done;
}
}
rc = 0;
done:
os_trace_api_ret_u32(OS_TRACE_ID_MBUF_FREE, (uint32_t)rc);
return (rc);
}
int
os_mbuf_free_chain(struct os_mbuf *om)
{
struct os_mbuf *next;
int rc;
os_trace_api_u32(OS_TRACE_ID_MBUF_FREE_CHAIN, (uint32_t)om);
while (om != NULL) {
next = SLIST_NEXT(om, om_next);
rc = os_mbuf_free(om);
if (rc != 0) {
goto done;
}
om = next;
}
rc = 0;
done:
os_trace_api_ret_u32(OS_TRACE_ID_MBUF_FREE_CHAIN, (uint32_t)rc);
return (rc);
}
/**
* Copy a packet header from one mbuf to another.
*
* @param omp The mbuf pool associated with these buffers
* @param new_buf The new buffer to copy the packet header into
* @param old_buf The old buffer to copy the packet header from
*/
static inline void
_os_mbuf_copypkthdr(struct os_mbuf *new_buf, struct os_mbuf *old_buf)
{
assert(new_buf->om_len == 0);
memcpy(&new_buf->om_databuf[0], &old_buf->om_databuf[0],
old_buf->om_pkthdr_len);
new_buf->om_pkthdr_len = old_buf->om_pkthdr_len;
new_buf->om_data = new_buf->om_databuf + old_buf->om_pkthdr_len;
}
uint16_t
os_mbuf_len(const struct os_mbuf *om)
{
uint16_t len;
len = 0;
while (om != NULL) {
len += om->om_len;
om = SLIST_NEXT(om, om_next);
}
return len;
}
int
os_mbuf_append(struct os_mbuf *om, const void *data, uint16_t len)
{
struct os_mbuf_pool *omp;
struct os_mbuf *last;
struct os_mbuf *new;
int remainder;
int space;
int rc;
if (om == NULL) {
rc = OS_EINVAL;
goto err;
}
omp = om->om_omp;
/* Scroll to last mbuf in the chain */
last = om;
while (SLIST_NEXT(last, om_next) != NULL) {
last = SLIST_NEXT(last, om_next);
}
remainder = len;
space = OS_MBUF_TRAILINGSPACE(last);
/* If room in current mbuf, copy the first part of the data into the
* remaining space in that mbuf.
*/
if (space > 0) {
if (space > remainder) {
space = remainder;
}
memcpy(OS_MBUF_DATA(last, uint8_t *) + last->om_len , data, space);
last->om_len += space;
data += space;
remainder -= space;
}
/* Take the remaining data, and keep allocating new mbufs and copying
* data into it, until data is exhausted.
*/
while (remainder > 0) {
new = os_mbuf_get(omp, 0);
if (!new) {
break;
}
new->om_len = min(omp->omp_databuf_len, remainder);
memcpy(OS_MBUF_DATA(new, void *), data, new->om_len);
data += new->om_len;
remainder -= new->om_len;
SLIST_NEXT(last, om_next) = new;
last = new;
}
/* Adjust the packet header length in the buffer */
if (OS_MBUF_IS_PKTHDR(om)) {
OS_MBUF_PKTHDR(om)->omp_len += len - remainder;
}
if (remainder != 0) {
rc = OS_ENOMEM;
goto err;
}
return (0);
err:
return (rc);
}
int
os_mbuf_appendfrom(struct os_mbuf *dst, const struct os_mbuf *src,
uint16_t src_off, uint16_t len)
{
const struct os_mbuf *src_cur_om;
uint16_t src_cur_off;
uint16_t chunk_sz;
int rc;
src_cur_om = os_mbuf_off(src, src_off, &src_cur_off);
while (len > 0) {
if (src_cur_om == NULL) {
return OS_EINVAL;
}
chunk_sz = min(len, src_cur_om->om_len - src_cur_off);
rc = os_mbuf_append(dst, src_cur_om->om_data + src_cur_off, chunk_sz);
if (rc != 0) {
return rc;
}
len -= chunk_sz;
src_cur_om = SLIST_NEXT(src_cur_om, om_next);
src_cur_off = 0;
}
return 0;
}
struct os_mbuf *
os_mbuf_dup(struct os_mbuf *om)
{
struct os_mbuf_pool *omp;
struct os_mbuf *head;
struct os_mbuf *copy;
omp = om->om_omp;
head = NULL;
copy = NULL;
for (; om != NULL; om = SLIST_NEXT(om, om_next)) {
if (head) {
SLIST_NEXT(copy, om_next) = os_mbuf_get(omp,
OS_MBUF_LEADINGSPACE(om));
if (!SLIST_NEXT(copy, om_next)) {
os_mbuf_free_chain(head);
goto err;
}
copy = SLIST_NEXT(copy, om_next);
} else {
head = os_mbuf_get(omp, OS_MBUF_LEADINGSPACE(om));
if (!head) {
goto err;
}
if (OS_MBUF_IS_PKTHDR(om)) {
_os_mbuf_copypkthdr(head, om);
}
copy = head;
}
copy->om_flags = om->om_flags;
copy->om_len = om->om_len;
memcpy(OS_MBUF_DATA(copy, uint8_t *), OS_MBUF_DATA(om, uint8_t *),
om->om_len);
}
return (head);
err:
return (NULL);
}
struct os_mbuf *
os_mbuf_off(const struct os_mbuf *om, int off, uint16_t *out_off)
{
struct os_mbuf *next;
struct os_mbuf *cur;
/* Cast away const. */
cur = (struct os_mbuf *)om;
while (1) {
if (cur == NULL) {
return NULL;
}
next = SLIST_NEXT(cur, om_next);
if (cur->om_len > off ||
(cur->om_len == off && next == NULL)) {
*out_off = off;
return cur;
}
off -= cur->om_len;
cur = next;
}
}
int
os_mbuf_copydata(const struct os_mbuf *m, int off, int len, void *dst)
{
unsigned int count;
uint8_t *udst;
if (!len) {
return 0;
}
udst = dst;
while (off > 0) {
if (!m) {
return (-1);
}
if (off < m->om_len)
break;
off -= m->om_len;
m = SLIST_NEXT(m, om_next);
}
while (len > 0 && m != NULL) {
count = min(m->om_len - off, len);
memcpy(udst, m->om_data + off, count);
len -= count;
udst += count;
off = 0;
m = SLIST_NEXT(m, om_next);
}
return (len > 0 ? -1 : 0);
}
void
os_mbuf_adj(struct os_mbuf *mp, int req_len)
{
int len = req_len;
struct os_mbuf *m;
int count;
if ((m = mp) == NULL)
return;
if (len >= 0) {
/*
* Trim from head.
*/
while (m != NULL && len > 0) {
if (m->om_len <= len) {
len -= m->om_len;
m->om_len = 0;
m = SLIST_NEXT(m, om_next);
} else {
m->om_len -= len;
m->om_data += len;
len = 0;
}
}
if (OS_MBUF_IS_PKTHDR(mp))
OS_MBUF_PKTHDR(mp)->omp_len -= (req_len - len);
} else {
/*
* Trim from tail. Scan the mbuf chain,
* calculating its length and finding the last mbuf.
* If the adjustment only affects this mbuf, then just
* adjust and return. Otherwise, rescan and truncate
* after the remaining size.
*/
len = -len;
count = 0;
for (;;) {
count += m->om_len;
if (SLIST_NEXT(m, om_next) == (struct os_mbuf *)0)
break;
m = SLIST_NEXT(m, om_next);
}
if (m->om_len >= len) {
m->om_len -= len;
if (OS_MBUF_IS_PKTHDR(mp))
OS_MBUF_PKTHDR(mp)->omp_len -= len;
return;
}
count -= len;
if (count < 0)
count = 0;
/*
* Correct length for chain is "count".
* Find the mbuf with last data, adjust its length,
* and toss data from remaining mbufs on chain.
*/
m = mp;
if (OS_MBUF_IS_PKTHDR(m))
OS_MBUF_PKTHDR(m)->omp_len = count;
for (; m; m = SLIST_NEXT(m, om_next)) {
if (m->om_len >= count) {
m->om_len = count;
if (SLIST_NEXT(m, om_next) != NULL) {
os_mbuf_free_chain(SLIST_NEXT(m, om_next));
SLIST_NEXT(m, om_next) = NULL;
}
break;
}
count -= m->om_len;
}
}
}
int
os_mbuf_cmpf(const struct os_mbuf *om, int off, const void *data, int len)
{
uint16_t chunk_sz;
uint16_t data_off;
uint16_t om_off;
int rc;
if (len <= 0) {
return 0;
}
data_off = 0;
om = os_mbuf_off(om, off, &om_off);
while (1) {
if (om == NULL) {
return INT_MAX;
}
chunk_sz = min(om->om_len - om_off, len - data_off);
if (chunk_sz > 0) {
rc = memcmp(om->om_data + om_off, data + data_off, chunk_sz);
if (rc != 0) {
return rc;
}
}
data_off += chunk_sz;
if (data_off == len) {
return 0;
}
om = SLIST_NEXT(om, om_next);
om_off = 0;
if (om == NULL) {
return INT_MAX;
}
}
}
int
os_mbuf_cmpm(const struct os_mbuf *om1, uint16_t offset1,
const struct os_mbuf *om2, uint16_t offset2,
uint16_t len)
{
const struct os_mbuf *cur1;
const struct os_mbuf *cur2;
uint16_t bytes_remaining;
uint16_t chunk_sz;
uint16_t om1_left;
uint16_t om2_left;
uint16_t om1_off;
uint16_t om2_off;
int rc;
om1_off = 0;
om2_off = 0;
cur1 = os_mbuf_off(om1, offset1, &om1_off);
cur2 = os_mbuf_off(om2, offset2, &om2_off);
bytes_remaining = len;
while (1) {
if (bytes_remaining == 0) {
return 0;
}
while (cur1 != NULL && om1_off >= cur1->om_len) {
cur1 = SLIST_NEXT(cur1, om_next);
om1_off = 0;
}
while (cur2 != NULL && om2_off >= cur2->om_len) {
cur2 = SLIST_NEXT(cur2, om_next);
om2_off = 0;
}
if (cur1 == NULL || cur2 == NULL) {
return INT_MAX;
}
om1_left = cur1->om_len - om1_off;
om2_left = cur2->om_len - om2_off;
chunk_sz = min(min(om1_left, om2_left), bytes_remaining);
rc = memcmp(cur1->om_data + om1_off, cur2->om_data + om2_off,
chunk_sz);
if (rc != 0) {
return rc;
}
om1_off += chunk_sz;
om2_off += chunk_sz;
bytes_remaining -= chunk_sz;
}
}
struct os_mbuf *
os_mbuf_prepend(struct os_mbuf *om, int len)
{
struct os_mbuf *p;
int leading;
while (1) {
/* Fill the available space at the front of the head of the chain, as
* needed.
*/
leading = min(len, OS_MBUF_LEADINGSPACE(om));
om->om_data -= leading;
om->om_len += leading;
if (OS_MBUF_IS_PKTHDR(om)) {
OS_MBUF_PKTHDR(om)->omp_len += leading;
}
len -= leading;
if (len == 0) {
break;
}
/* The current head didn't have enough space; allocate a new head. */
if (OS_MBUF_IS_PKTHDR(om)) {
p = os_mbuf_get_pkthdr(om->om_omp,
om->om_pkthdr_len - sizeof (struct os_mbuf_pkthdr));
} else {
p = os_mbuf_get(om->om_omp, 0);
}
if (p == NULL) {
os_mbuf_free_chain(om);
om = NULL;
break;
}
if (OS_MBUF_IS_PKTHDR(om)) {
_os_mbuf_copypkthdr(p, om);
om->om_pkthdr_len = 0;
}
/* Move the new head's data pointer to the end so that data can be
* prepended.
*/
p->om_data += OS_MBUF_TRAILINGSPACE(p);
SLIST_NEXT(p, om_next) = om;
om = p;
}
return om;
}
struct os_mbuf *
os_mbuf_prepend_pullup(struct os_mbuf *om, uint16_t len)
{
om = os_mbuf_prepend(om, len);
if (om == NULL) {
return NULL;
}
om = os_mbuf_pullup(om, len);
if (om == NULL) {
return NULL;
}
return om;
}
int
os_mbuf_copyinto(struct os_mbuf *om, int off, const void *src, int len)
{
struct os_mbuf *next;
struct os_mbuf *cur;
const uint8_t *sptr;
uint16_t cur_off;
int copylen;
int rc;
/* Find the mbuf,offset pair for the start of the destination. */
cur = os_mbuf_off(om, off, &cur_off);
if (cur == NULL) {
return -1;
}
/* Overwrite existing data until we reach the end of the chain. */
sptr = src;
while (1) {
copylen = min(cur->om_len - cur_off, len);
if (copylen > 0) {
memcpy(cur->om_data + cur_off, sptr, copylen);
sptr += copylen;
len -= copylen;
copylen = 0;
}
if (len == 0) {
/* All the source data fit in the existing mbuf chain. */
return 0;
}
next = SLIST_NEXT(cur, om_next);
if (next == NULL) {
break;
}
cur = next;
cur_off = 0;
}
/* Append the remaining data to the end of the chain. */
rc = os_mbuf_append(cur, sptr, len);
if (rc != 0) {
return rc;
}
/* Fix up the packet header, if one is present. */
if (OS_MBUF_IS_PKTHDR(om)) {
OS_MBUF_PKTHDR(om)->omp_len =
max(OS_MBUF_PKTHDR(om)->omp_len, off + len);
}
return 0;
}
void
os_mbuf_concat(struct os_mbuf *first, struct os_mbuf *second)
{
struct os_mbuf *next;
struct os_mbuf *cur;
/* Point 'cur' to the last buffer in the first chain. */
cur = first;
while (1) {
next = SLIST_NEXT(cur, om_next);
if (next == NULL) {
break;
}
cur = next;
}
/* Attach the second chain to the end of the first. */
SLIST_NEXT(cur, om_next) = second;
/* If the first chain has a packet header, calculate the length of the
* second chain and add it to the header length.
*/
if (OS_MBUF_IS_PKTHDR(first)) {
if (OS_MBUF_IS_PKTHDR(second)) {
OS_MBUF_PKTHDR(first)->omp_len += OS_MBUF_PKTHDR(second)->omp_len;
} else {
for (cur = second; cur != NULL; cur = SLIST_NEXT(cur, om_next)) {
OS_MBUF_PKTHDR(first)->omp_len += cur->om_len;
}
}
}
second->om_pkthdr_len = 0;
}
void *
os_mbuf_extend(struct os_mbuf *om, uint16_t len)
{
struct os_mbuf *newm;
struct os_mbuf *last;
void *data;
if (len > om->om_omp->omp_databuf_len) {
return NULL;
}
/* Scroll to last mbuf in the chain */
last = om;
while (SLIST_NEXT(last, om_next) != NULL) {
last = SLIST_NEXT(last, om_next);
}
if (OS_MBUF_TRAILINGSPACE(last) < len) {
newm = os_mbuf_get(om->om_omp, 0);
if (newm == NULL) {
return NULL;
}
SLIST_NEXT(last, om_next) = newm;
last = newm;
}
data = last->om_data + last->om_len;
last->om_len += len;
if (OS_MBUF_IS_PKTHDR(om)) {
OS_MBUF_PKTHDR(om)->omp_len += len;
}
return data;
}
struct os_mbuf *
os_mbuf_pullup(struct os_mbuf *om, uint16_t len)
{
struct os_mbuf_pool *omp;
struct os_mbuf *next;
struct os_mbuf *om2;
int count;
int space;
omp = om->om_omp;
/*
* If first mbuf has no cluster, and has room for len bytes
* without shifting current data, pullup into it,
* otherwise allocate a new mbuf to prepend to the chain.
*/
if (om->om_len >= len) {
return (om);
}
if (om->om_len + OS_MBUF_TRAILINGSPACE(om) >= len &&
SLIST_NEXT(om, om_next)) {
om2 = om;
om = SLIST_NEXT(om, om_next);
len -= om2->om_len;
} else {
if (len > omp->omp_databuf_len - om->om_pkthdr_len) {
goto bad;
}
om2 = os_mbuf_get(omp, 0);
if (om2 == NULL) {
goto bad;
}
if (OS_MBUF_IS_PKTHDR(om)) {
_os_mbuf_copypkthdr(om2, om);
}
}
space = OS_MBUF_TRAILINGSPACE(om2);
do {
count = min(min(len, space), om->om_len);
memcpy(om2->om_data + om2->om_len, om->om_data, count);
len -= count;
om2->om_len += count;
om->om_len -= count;
space -= count;
if (om->om_len) {
om->om_data += count;
} else {
next = SLIST_NEXT(om, om_next);
os_mbuf_free(om);
om = next;
}
} while (len > 0 && om);
if (len > 0) {
os_mbuf_free(om2);
goto bad;
}
SLIST_NEXT(om2, om_next) = om;
return (om2);
bad:
os_mbuf_free_chain(om);
return (NULL);
}
struct os_mbuf *
os_mbuf_trim_front(struct os_mbuf *om)
{
struct os_mbuf *next;
struct os_mbuf *cur;
/* Abort early if there is nothing to trim. */
if (om->om_len != 0) {
return om;
}
/* Starting with the second mbuf in the chain, continue removing and
* freeing mbufs until an non-empty one is encountered.
*/
cur = SLIST_NEXT(om, om_next);
while (cur != NULL && cur->om_len == 0) {
next = SLIST_NEXT(cur, om_next);
SLIST_NEXT(om, om_next) = next;
os_mbuf_free(cur);
cur = next;
}
if (cur == NULL) {
/* All buffers after the first have been freed. */
return om;
}
/* Try to remove the first mbuf in the chain. If this buffer contains a
* packet header, make sure the second buffer can accommodate it.
*/
if (OS_MBUF_LEADINGSPACE(cur) >= om->om_pkthdr_len) {
/* Second buffer has room; copy packet header. */
cur->om_pkthdr_len = om->om_pkthdr_len;
memcpy(OS_MBUF_PKTHDR(cur), OS_MBUF_PKTHDR(om), om->om_pkthdr_len);
/* Free first buffer. */
os_mbuf_free(om);
om = cur;
}
return om;
}
int
os_mbuf_widen(struct os_mbuf *om, uint16_t off, uint16_t len)
{
struct os_mbuf *first_new;
struct os_mbuf *edge_om;
struct os_mbuf *prev;
struct os_mbuf *cur;
uint16_t rem_len;
uint16_t sub_off;
int rc;
/* Locate the mbuf and offset within the chain where the gap will be
* inserted.
*/
edge_om = os_mbuf_off(om, off, &sub_off);
if (edge_om == NULL) {
return SYS_EINVAL;
}
/* If the mbuf has sufficient capacity for the gap, just make room within
* the mbuf.
*/
if (OS_MBUF_TRAILINGSPACE(edge_om) >= len) {
memmove(edge_om->om_data + sub_off + len,
edge_om->om_data + sub_off,
edge_om->om_len - sub_off);
edge_om->om_len += len;
if (OS_MBUF_IS_PKTHDR(om)) {
OS_MBUF_PKTHDR(om)->omp_len += len;
}
return 0;
}
/* Otherwise, allocate new mbufs until the chain has sufficient capacity
* for the gap.
*/
rem_len = len;
first_new = NULL;
prev = NULL;
while (rem_len > 0) {
cur = os_mbuf_get(om->om_omp, 0);
if (cur == NULL) {
/* Free only the mbufs that this function allocated. */
os_mbuf_free_chain(first_new);
return SYS_ENOMEM;
}
/* Remember the start of the chain of new mbufs. */
if (first_new == NULL) {
first_new = cur;
}
if (rem_len > OS_MBUF_TRAILINGSPACE(cur)) {
cur->om_len = OS_MBUF_TRAILINGSPACE(cur);
} else {
cur->om_len = rem_len;
}
rem_len -= cur->om_len;
if (prev != NULL) {
SLIST_NEXT(prev, om_next) = cur;
}
prev = cur;
}
/* Move the misplaced data from the edge mbuf over to the right side of the
* gap.
*/
rc = os_mbuf_append(prev, edge_om->om_data + sub_off,
edge_om->om_len - sub_off);
if (rc != 0) {
os_mbuf_free_chain(first_new);
return SYS_ENOMEM;
}
edge_om->om_len = sub_off;
/* Insert the gap into the chain. */
SLIST_NEXT(prev, om_next) = SLIST_NEXT(edge_om, om_next);
SLIST_NEXT(edge_om, om_next) = first_new;
if (OS_MBUF_IS_PKTHDR(om)) {
OS_MBUF_PKTHDR(om)->omp_len += len;
}
return 0;
}