| /** |
| * Copyright (c) Runtime Inc. |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| /* |
| * 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 "os/os.h" |
| |
| #include <string.h> |
| |
| int |
| os_mqueue_init(struct os_mqueue *mq, void *arg) |
| { |
| struct os_event *ev; |
| |
| STAILQ_INIT(&mq->mq_head); |
| |
| ev = &mq->mq_ev; |
| memset(ev, 0, sizeof(*ev)); |
| ev->ev_arg = arg; |
| ev->ev_type = OS_EVENT_T_MQUEUE_DATA; |
| |
| 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); |
| |
| m = OS_MBUF_PKTHDR_TO_MBUF(mp); |
| |
| 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; |
| |
| 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); |
| } |
| |
| |
| /** |
| * Initialize a pool of mbufs. |
| * |
| * @param omp The mbuf pool to initialize |
| * @param mp The memory pool that will hold this mbuf pool |
| * @param buf_len The length of the buffer itself. |
| * @param nbufs The number of buffers in the pool |
| * |
| * @return 0 on success, error code on failure. |
| */ |
| 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_mbuf_count = nbufs; |
| omp->omp_pool = mp; |
| |
| return (0); |
| } |
| |
| /** |
| * Get an mbuf from the mbuf pool. The mbuf is allocated, and initialized |
| * prior to being returned. |
| * |
| * @param omp The mbuf pool to return the packet from |
| * @param leadingspace The amount of leadingspace to put before the data |
| * section by default. |
| * |
| * @return An initialized mbuf on success, and NULL on failure. |
| */ |
| struct os_mbuf * |
| os_mbuf_get(struct os_mbuf_pool *omp, uint16_t leadingspace) |
| { |
| struct os_mbuf *om; |
| |
| om = os_memblock_get(omp->omp_pool); |
| if (!om) { |
| goto err; |
| } |
| |
| SLIST_NEXT(om, om_next) = NULL; |
| om->om_flags = 0; |
| om->om_len = 0; |
| om->om_data = (&om->om_databuf[0] + leadingspace); |
| om->om_omp = omp; |
| |
| return (om); |
| err: |
| return (NULL); |
| } |
| |
| /* Allocate a new packet header mbuf out of the os_mbuf_pool */ |
| struct os_mbuf * |
| os_mbuf_get_pkthdr(struct os_mbuf_pool *omp, uint8_t extra_pkthdr_len) |
| { |
| struct os_mbuf_pkthdr *pkthdr; |
| struct os_mbuf *om; |
| |
| om = os_mbuf_get(omp, 0); |
| if (om) { |
| om->om_pkthdr_len = extra_pkthdr_len + sizeof(struct os_mbuf_pkthdr); |
| om->om_data += extra_pkthdr_len + sizeof(struct os_mbuf_pkthdr); |
| |
| pkthdr = OS_MBUF_PKTHDR(om); |
| pkthdr->omp_len = 0; |
| pkthdr->omp_flags = 0; |
| STAILQ_NEXT(pkthdr, omp_next) = NULL; |
| } |
| |
| return om; |
| } |
| |
| /** |
| * Release a mbuf back to the pool |
| * |
| * @param omp The Mbuf pool to release back to |
| * @param om The Mbuf to release back to the pool |
| * |
| * @return 0 on success, -1 on failure |
| */ |
| int |
| os_mbuf_free(struct os_mbuf *om) |
| { |
| int rc; |
| |
| rc = os_memblock_put(om->om_omp->omp_pool, om); |
| if (rc != 0) { |
| goto err; |
| } |
| |
| return (0); |
| err: |
| return (rc); |
| } |
| |
| /** |
| * Free a chain of mbufs |
| * |
| * @param omp The mbuf pool to free the chain of mbufs into |
| * @param om The starting mbuf of the chain to free back into the pool |
| * |
| * @return 0 on success, -1 on failure |
| */ |
| int |
| os_mbuf_free_chain(struct os_mbuf *om) |
| { |
| struct os_mbuf *next; |
| int rc; |
| |
| while (om != NULL) { |
| next = SLIST_NEXT(om, om_next); |
| |
| rc = os_mbuf_free(om); |
| if (rc != 0) { |
| goto err; |
| } |
| |
| om = next; |
| } |
| |
| return (0); |
| err: |
| 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) |
| { |
| memcpy(&new_buf->om_databuf[0], &old_buf->om_databuf[0], |
| old_buf->om_pkthdr_len); |
| } |
| |
| /** |
| * Append data onto a mbuf |
| * |
| * @param omp The mbuf pool this mbuf was allocated out of |
| * @param om The mbuf to append the data onto |
| * @param data The data to append onto the mbuf |
| * @param len The length of the data to append |
| * |
| * @return 0 on success, and an error code on failure |
| */ |
| 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, void *) + 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(om, 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); |
| } |
| |
| |
| /** |
| * Duplicate a chain of mbufs. Return the start of the duplicated chain. |
| * |
| * @param omp The mbuf pool to duplicate out of |
| * @param om The mbuf chain to duplicate |
| * |
| * @return A pointer to the new chain of mbufs |
| */ |
| 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); |
| } |
| |
| /** |
| * Locates the specified absolute offset within an mbuf chain. The offset |
| * can be one past than the total length of the chain, but no greater. |
| * |
| * @param om The start of the mbuf chain to seek within. |
| * @param off The absolute address to find. |
| * @param out_off On success, this points to the relative offset |
| * within the returned mbuf. |
| * |
| * @return The mbuf containing the specified offset on |
| * success. |
| * NULL if the specified offset is out of bounds. |
| */ |
| struct os_mbuf * |
| os_mbuf_off(struct os_mbuf *om, int off, int *out_off) |
| { |
| struct os_mbuf *next; |
| |
| while (1) { |
| if (om == NULL) { |
| return NULL; |
| } |
| |
| next = SLIST_NEXT(om, om_next); |
| |
| if (om->om_len > off || |
| (om->om_len == off && next == NULL)) { |
| |
| *out_off = off; |
| return om; |
| } |
| |
| off -= om->om_len; |
| om = next; |
| } |
| } |
| |
| /* |
| * Copy data from an mbuf chain starting "off" bytes from the beginning, |
| * continuing for "len" bytes, into the indicated buffer. |
| * |
| * @return 0 on success; |
| * -1 if the mbuf does not contain enough data. |
| */ |
| int |
| os_mbuf_copydata(const struct os_mbuf *m, int off, int len, void *dst) |
| { |
| unsigned int count; |
| uint8_t *udst; |
| |
| 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; |
| } |
| } |
| } |
| |
| /** |
| * Performs a memory compare of the specified region of an mbuf chain against a |
| * flat buffer. |
| * |
| * @param om The start of the mbuf chain to compare. |
| * @param off The offset within the mbuf chain to start the |
| * comparison. |
| * @param data The flat buffer to compare. |
| * @param len The length of the flat buffer. |
| * |
| * @return 0 if both memory regions are identical; |
| * A memcmp return code if there is a mismatch; |
| * -1 if the mbuf is too short. |
| */ |
| int |
| os_mbuf_memcmp(const struct os_mbuf *om, int off, const void *data, int len) |
| { |
| int chunk_sz; |
| int data_off; |
| int om_off; |
| int rc; |
| |
| if (len <= 0) { |
| return 0; |
| } |
| |
| data_off = 0; |
| om = os_mbuf_off((struct os_mbuf *)om, off, &om_off); |
| while (1) { |
| if (om == NULL) { |
| return -1; |
| } |
| |
| 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 -1; |
| } |
| } |
| } |
| |
| /** |
| * Increases the length of an mbuf chain by adding data to the front. If there |
| * is insufficient room in the leading mbuf, additional mbufs are allocated and |
| * prepended as necessary. If this function fails to allocate an mbuf, the |
| * entire chain is freed. |
| * |
| * The specified mbuf chain does not need to contain a packet header. |
| * |
| * @param omp The mbuf pool to allocate from. |
| * @param om The head of the mbuf chain. |
| * @param len The number of bytes to prepend. |
| * |
| * @return The new head of the chain on success; |
| * NULL on failure. |
| */ |
| 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; |
| } |
| |
| /** |
| * Copies the contents of a flat buffer into an mbuf chain, starting at the |
| * specified destination offset. If the mbuf is too small for the source data, |
| * it is extended as necessary. If the destination mbuf contains a packet |
| * header, the header length is updated. |
| * |
| * @param omp The mbuf pool to allocate from. |
| * @param om The mbuf chain to copy into. |
| * @param off The offset within the chain to copy to. |
| * @param src The source buffer to copy from. |
| * @param len The number of bytes to copy. |
| * |
| * @return 0 on success; nonzero on failure. |
| */ |
| 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; |
| int copylen; |
| int cur_off; |
| 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; |
| } |
| |
| /* 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; |
| } |
| |
| /** |
| * Attaches a second mbuf chain onto the end of the first. If the first chain |
| * contains a packet header, the header's length is updated. If the second |
| * chain has a packet header, its header is cleared. |
| * |
| * @param first The mbuf chain being attached to. |
| * @param second The mbuf chain that gets attached. |
| */ |
| 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; |
| } |
| |
| /** |
| * Increases the length of an mbuf chain by the specified amount. If there is |
| * not sufficient room in the last buffer, a new buffer is allocated and |
| * appended to the chain. It is an error to request more data than can fit in |
| * a single buffer. |
| * |
| * @param omp |
| * @param om The head of the chain to extend. |
| * @param len The number of bytes to extend by. |
| * |
| * @return A pointer to the new data on success; |
| * NULL on failure. |
| */ |
| 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; |
| } |
| |
| #if 0 |
| |
| /** |
| * Rearrange a mbuf chain so that len bytes are contiguous, |
| * and in the data area of an mbuf (so that OS_MBUF_DATA() will |
| * work on a structure of size len.) Returns the resulting |
| * mbuf chain on success, free's it and returns NULL on failure. |
| * |
| * If there is room, it will add up to "max_protohdr - len" |
| * extra bytes to the contiguous region, in an attempt to avoid being |
| * called next time. |
| * |
| * @param omp The mbuf pool to take the mbufs out of |
| * @param om The mbuf chain to make contiguous |
| * @param len The number of bytes in the chain to make contiguous |
| * |
| * @return The contiguous mbuf chain on success, NULL on failure. |
| */ |
| struct os_mbuf * |
| os_mbuf_pullup(struct os_mbuf *om, uint16_t len) |
| { |
| struct os_mbuf_pool *omp; |
| struct os_mbuf *newm; |
| |
| omp = om->om_omp; |
| |
| if (len > omp->omp_databuf_len) { |
| goto err; |
| } |
| |
| /* Is 'n' bytes already contiguous? */ |
| if (((uint8_t *) &om->om_databuf[0] + omp->omp_databuf_len) - |
| OS_MBUF_DATA(om, uint8_t *) >= len) { |
| newm = om; |
| goto done; |
| } |
| |
| /* Nope, OK. Allocate a new buffer, and then go through and copy 'n' |
| * bytes into that buffer. |
| */ |
| newm = os_mbuf_get(omp, 0); |
| if (!newm) { |
| goto err; |
| } |
| |
| written = 0; |
| while (written < len |
| |
| |
| done: |
| return (newm); |
| err: |
| if (om) { |
| os_mbuf_free_chain(om); |
| } |
| |
| return (NULL); |
| } |
| #endif |
