/*
 * Copyright (c) 2004-2024 Apple Inc. All rights reserved.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
 *
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. The rights granted to you under the License
 * may not be used to create, or enable the creation or redistribution of,
 * unlawful or unlicensed copies of an Apple operating system, or to
 * circumvent, violate, or enable the circumvention or violation of, any
 * terms of an Apple operating system software license agreement.
 *
 * Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this file.
 *
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
 */

#define __KPI__

#include <sys/param.h>
#include <sys/cdefs.h>
#include <sys/mbuf.h>
#include <sys/mcache.h>
#include <sys/socket.h>
#include <kern/debug.h>
#include <libkern/OSAtomic.h>
#include <string.h>
#include <net/dlil.h>
#include <netinet/in.h>
#include <netinet/ip_var.h>

#include <os/log.h>

#include "net/net_str_id.h"

/* mbuf flags visible to KPI clients; do not add private flags here */
static const mbuf_flags_t mbuf_flags_mask = (MBUF_EXT | MBUF_PKTHDR | MBUF_EOR |
    MBUF_LOOP | MBUF_BCAST | MBUF_MCAST | MBUF_FRAG | MBUF_FIRSTFRAG |
    MBUF_LASTFRAG | MBUF_PROMISC | MBUF_HASFCS);

/* Unalterable mbuf flags */
static const mbuf_flags_t mbuf_cflags_mask = (MBUF_EXT);

#define MAX_MBUF_TX_COMPL_FUNC 8
mbuf_tx_compl_func
    mbuf_tx_compl_table[MAX_MBUF_TX_COMPL_FUNC];
extern lck_rw_t mbuf_tx_compl_tbl_lock;
u_int32_t mbuf_tx_compl_index = 0;

#if (DEVELOPMENT || DEBUG)
int mbuf_tx_compl_debug = 0;
uint64_t mbuf_tx_compl_requested __attribute__((aligned(8))) = 0;
uint64_t mbuf_tx_compl_callbacks __attribute__((aligned(8))) = 0;
uint64_t mbuf_tx_compl_aborted __attribute__((aligned(8))) = 0;

SYSCTL_DECL(_kern_ipc);
SYSCTL_NODE(_kern_ipc, OID_AUTO, mbtxcf,
    CTLFLAG_RW | CTLFLAG_LOCKED, 0, "");
SYSCTL_INT(_kern_ipc_mbtxcf, OID_AUTO, debug,
    CTLFLAG_RW | CTLFLAG_LOCKED, &mbuf_tx_compl_debug, 0, "");
SYSCTL_INT(_kern_ipc_mbtxcf, OID_AUTO, index,
    CTLFLAG_RD | CTLFLAG_LOCKED, &mbuf_tx_compl_index, 0, "");
SYSCTL_QUAD(_kern_ipc_mbtxcf, OID_AUTO, requested,
    CTLFLAG_RD | CTLFLAG_LOCKED, &mbuf_tx_compl_requested, "");
SYSCTL_QUAD(_kern_ipc_mbtxcf, OID_AUTO, callbacks,
    CTLFLAG_RD | CTLFLAG_LOCKED, &mbuf_tx_compl_callbacks, "");
SYSCTL_QUAD(_kern_ipc_mbtxcf, OID_AUTO, aborted,
    CTLFLAG_RD | CTLFLAG_LOCKED, &mbuf_tx_compl_aborted, "");
#endif /* (DEBUG || DEVELOPMENT) */

void * __unsafe_indexable
mbuf_data(mbuf_t mbuf)
{
	return m_mtod_current(mbuf);
}

errno_t
mbuf_data_len(mbuf_t mbuf, void *__sized_by(*out_len) *out_buf, size_t *out_len)
{
	size_t  len;
	void   *buf;

	if (out_len == NULL || out_buf == NULL) {
		return EINVAL;
	}

	len = mbuf_len(mbuf);
	buf = m_mtod_current(mbuf);

	if (len == 0 || buf == NULL) {
		return ENOENT;
	}

	*out_len = len;
	*out_buf = buf;

	return 0;
}

void *
mbuf_datastart(mbuf_t mbuf)
{
	if (mbuf->m_flags & M_EXT) {
		return mbuf->m_ext.ext_buf;
	}
	if (mbuf->m_flags & M_PKTHDR) {
		return mbuf->m_pktdat;
	}
	return mbuf->m_dat;
}

errno_t
mbuf_setdata(mbuf_t mbuf, void *data, size_t len)
{
	size_t  start = (size_t)((char *)mbuf_datastart(mbuf));
	size_t  maxlen = mbuf_maxlen(mbuf);

	if ((size_t)data < start || ((size_t)data) + len > start + maxlen) {
		return EINVAL;
	}
	mbuf->m_data = (uintptr_t)data;
	mbuf->m_len = (int32_t)len;

	return 0;
}

errno_t
mbuf_align_32(mbuf_t mbuf, size_t len)
{
	if ((mbuf->m_flags & M_EXT) != 0 && m_mclhasreference(mbuf)) {
		return ENOTSUP;
	}
	mbuf->m_data = (uintptr_t)mbuf_datastart(mbuf);
	mbuf->m_data +=
	    ((mbuf_trailingspace(mbuf) - len) & ~(sizeof(u_int32_t) - 1));

	return 0;
}

/*
 * This function is used to provide mcl_to_paddr via symbol indirection,
 * please avoid any change in behavior or remove the indirection in
 * config/Unsupported*
 */
addr64_t
mbuf_data_to_physical(void *ptr)
{
	return (addr64_t)mcl_to_paddr(ptr);
}

errno_t
mbuf_get(mbuf_how_t how, mbuf_type_t type, mbuf_t *mbuf)
{
	/* Must set *mbuf to NULL in failure case */
	*mbuf = m_get(how, type);

	return *mbuf == NULL ? ENOMEM : 0;
}

errno_t
mbuf_gethdr(mbuf_how_t how, mbuf_type_t type, mbuf_t *mbuf)
{
	/* Must set *mbuf to NULL in failure case */
	*mbuf = m_gethdr(how, type);

	return *mbuf == NULL ? ENOMEM : 0;
}

errno_t
mbuf_attachcluster(mbuf_how_t how, mbuf_type_t type, mbuf_t *mbuf,
    caddr_t extbuf __sized_by_or_null(extsize), void (*extfree)(caddr_t, u_int, caddr_t),
    size_t extsize, caddr_t extarg)
{
	if (mbuf == NULL || extbuf == NULL || extfree == NULL || extsize == 0) {
		return EINVAL;
	}

	if ((*mbuf = m_clattach(*mbuf, type, extbuf,
	    extfree, extsize, extarg, how, 0)) == NULL) {
		return ENOMEM;
	}

	return 0;
}

errno_t
mbuf_ring_cluster_alloc(mbuf_how_t how, mbuf_type_t type, mbuf_t *mbuf,
    void (*extfree)(caddr_t, u_int, caddr_t), size_t *size)
{
	size_t extsize = 0;
	caddr_t extbuf __sized_by_or_null(extsize) = NULL;
	errno_t err;

	if (mbuf == NULL || extfree == NULL || size == NULL || *size == 0) {
		return EINVAL;
	}

	extsize = *size;
	extbuf = NULL;

	if ((err = mbuf_alloccluster(how, &extsize, &extbuf)) != 0) {
		return err;
	}

	VERIFY((extsize == 0 && extbuf == NULL) || (extsize != 0 && extbuf != NULL));

	if ((*mbuf = m_clattach(*mbuf, type, extbuf,
	    extfree, extsize, NULL, how, 1)) == NULL) {
		mbuf_freecluster(extbuf, extsize);
		return ENOMEM;
	}

	*size = extsize;

	return 0;
}

int
mbuf_ring_cluster_is_active(mbuf_t mbuf)
{
	return m_ext_paired_is_active(mbuf);
}

errno_t
mbuf_ring_cluster_activate(mbuf_t mbuf)
{
	if (mbuf_ring_cluster_is_active(mbuf)) {
		return EBUSY;
	}

	m_ext_paired_activate(mbuf);
	return 0;
}

errno_t
mbuf_cluster_set_prop(mbuf_t mbuf, u_int32_t oldprop, u_int32_t newprop)
{
	if (mbuf == NULL || !(mbuf->m_flags & M_EXT)) {
		return EINVAL;
	}

	return m_ext_set_prop(mbuf, oldprop, newprop) ? 0 : EBUSY;
}

errno_t
mbuf_cluster_get_prop(mbuf_t mbuf, u_int32_t *prop)
{
	if (mbuf == NULL || prop == NULL || !(mbuf->m_flags & M_EXT)) {
		return EINVAL;
	}

	*prop = m_ext_get_prop(mbuf);
	return 0;
}

errno_t
mbuf_alloccluster(mbuf_how_t how, size_t *size, char * __sized_by_or_null(*size) *addr)
{
	if (size == NULL || *size == 0 || addr == NULL) {
		return EINVAL;
	}
	caddr_t _addr = NULL;
	size_t _size = *size;

	if (_size <= MCLBYTES && (_addr = m_mclalloc(how)) != NULL) {
		_size = MCLBYTES;
	} else if (_size > MCLBYTES && _size <= MBIGCLBYTES &&
	    (_addr = m_bigalloc(how)) != NULL) {
		_size = MBIGCLBYTES;
	} else if (_size > MBIGCLBYTES && _size <= M16KCLBYTES &&
	    (_addr = m_16kalloc(how)) != NULL) {
		_size = M16KCLBYTES;
	} else {
		_size = 0;
	}

	if (_addr == NULL) {
		return ENOMEM;
	}

	*size = _size;
	*addr = _addr;

	return 0;
}

void
mbuf_freecluster(caddr_t addr, size_t size)
{
	if (size != MCLBYTES && size != MBIGCLBYTES && size != M16KCLBYTES) {
		panic("%s: invalid size (%ld) for cluster %p", __func__,
		    size, (void *)addr);
	}

	if (size == MCLBYTES) {
		m_mclfree(addr);
	} else if (size == MBIGCLBYTES) {
		m_bigfree(addr, MBIGCLBYTES, NULL);
	} else {
		m_16kfree(addr, M16KCLBYTES, NULL);
	}
}

errno_t
mbuf_getcluster(mbuf_how_t how, mbuf_type_t type, size_t size, mbuf_t *mbuf)
{
	/* Must set *mbuf to NULL in failure case */
	errno_t error = 0;
	int     created = 0;

	if (mbuf == NULL) {
		return EINVAL;
	}
	if (*mbuf == NULL) {
		*mbuf = m_get(how, type);
		if (*mbuf == NULL) {
			return ENOMEM;
		}
		created = 1;
	}
	/*
	 * At the time this code was written, m_{mclget,mbigget,m16kget}
	 * would always return the same value that was passed in to it.
	 */
	if (size == MCLBYTES) {
		*mbuf = m_mclget(*mbuf, how);
	} else if (size == MBIGCLBYTES) {
		*mbuf = m_mbigget(*mbuf, how);
	} else if (size == M16KCLBYTES) {
		*mbuf = m_m16kget(*mbuf, how);
	} else {
		error = EINVAL;
		goto out;
	}
	if (*mbuf == NULL || ((*mbuf)->m_flags & M_EXT) == 0) {
		error = ENOMEM;
	}
out:
	if (created && error != 0) {
		mbuf_free(*mbuf);
		*mbuf = NULL;
	}
	return error;
}

errno_t
mbuf_mclget(mbuf_how_t how, mbuf_type_t type, mbuf_t *mbuf)
{
	/* Must set *mbuf to NULL in failure case */
	errno_t error = 0;
	int             created = 0;
	if (mbuf == NULL) {
		return EINVAL;
	}
	if (*mbuf == NULL) {
		error = mbuf_get(how, type, mbuf);
		if (error) {
			return error;
		}
		created = 1;
	}

	/*
	 * At the time this code was written, m_mclget would always
	 * return the same value that was passed in to it.
	 */
	*mbuf = m_mclget(*mbuf, how);

	if (created && ((*mbuf)->m_flags & M_EXT) == 0) {
		mbuf_free(*mbuf);
		*mbuf = NULL;
	}
	if (*mbuf == NULL || ((*mbuf)->m_flags & M_EXT) == 0) {
		error = ENOMEM;
	}
	return error;
}


errno_t
mbuf_getpacket(mbuf_how_t how, mbuf_t *mbuf)
{
	/* Must set *mbuf to NULL in failure case */
	errno_t error = 0;

	*mbuf = m_getpacket_how(how);

	if (*mbuf == NULL) {
		if (how == MBUF_WAITOK) {
			error = ENOMEM;
		} else {
			error = EWOULDBLOCK;
		}
	}

	return error;
}

/*
 * This function is used to provide m_free via symbol indirection, please avoid
 * any change in behavior or remove the indirection in config/Unsupported*
 */
mbuf_t
mbuf_free(mbuf_t mbuf)
{
	return m_free(mbuf);
}

/*
 * This function is used to provide m_freem via symbol indirection, please avoid
 * any change in behavior or remove the indirection in config/Unsupported*
 */
void
mbuf_freem(mbuf_t mbuf)
{
	m_freem(mbuf);
}

int
mbuf_freem_list(mbuf_t mbuf)
{
	return m_freem_list(mbuf);
}

size_t
mbuf_leadingspace(const mbuf_t mbuf)
{
	return M_LEADINGSPACE(mbuf);
}

/*
 * This function is used to provide m_trailingspace via symbol indirection,
 * please avoid any change in behavior or remove the indirection in
 * config/Unsupported*
 */
size_t
mbuf_trailingspace(const mbuf_t mbuf)
{
	return M_TRAILINGSPACE(mbuf);
}

/* Manipulation */
errno_t
mbuf_copym(const mbuf_t src, size_t offset, size_t len,
    mbuf_how_t how, mbuf_t *new_mbuf)
{
	/* Must set *mbuf to NULL in failure case */
	*new_mbuf = m_copym(src, (int)offset, (int)len, how);

	return *new_mbuf == NULL ? ENOMEM : 0;
}

errno_t
mbuf_dup(const mbuf_t src, mbuf_how_t how, mbuf_t *new_mbuf)
{
	/* Must set *new_mbuf to NULL in failure case */
	*new_mbuf = m_dup(src, how);

	return *new_mbuf == NULL ? ENOMEM : 0;
}

errno_t
mbuf_prepend(mbuf_t *orig, size_t len, mbuf_how_t how)
{
	/* Must set *orig to NULL in failure case */
	*orig = m_prepend_2(*orig, (int)len, how, 0);

	return *orig == NULL ? ENOMEM : 0;
}

errno_t
mbuf_split(mbuf_t src, size_t offset,
    mbuf_how_t how, mbuf_t *new_mbuf)
{
	/* Must set *new_mbuf to NULL in failure case */
	*new_mbuf = m_split(src, (int)offset, how);

	return *new_mbuf == NULL ? ENOMEM : 0;
}

errno_t
mbuf_pullup(mbuf_t *mbuf, size_t len)
{
	/* Must set *mbuf to NULL in failure case */
	*mbuf = m_pullup(*mbuf, (int)len);

	return *mbuf == NULL ? ENOMEM : 0;
}

errno_t
mbuf_pulldown(mbuf_t src, size_t *offset, size_t len, mbuf_t *location)
{
	/* Must set *location to NULL in failure case */
	int new_offset;
	*location = m_pulldown(src, (int)*offset, (int)len, &new_offset);
	*offset = new_offset;

	return *location == NULL ? ENOMEM : 0;
}

/*
 * This function is used to provide m_adj via symbol indirection, please avoid
 * any change in behavior or remove the indirection in config/Unsupported*
 */
void
mbuf_adj(mbuf_t mbuf, int len)
{
	m_adj(mbuf, len);
}

errno_t
mbuf_adjustlen(mbuf_t m, int amount)
{
	/* Verify m_len will be valid after adding amount */
	if (amount > 0) {
		size_t used = (size_t)mtod(m, void*) - (size_t)mbuf_datastart(m) +
		    m->m_len;

		if ((size_t)(amount + used) > mbuf_maxlen(m)) {
			return EINVAL;
		}
	} else if (-amount > m->m_len) {
		return EINVAL;
	}

	m->m_len += amount;
	return 0;
}

mbuf_t
mbuf_concatenate(mbuf_t dst, mbuf_t src)
{
	if (dst == NULL) {
		return NULL;
	}

	m_cat(dst, src);

	/* return dst as is in the current implementation */
	return dst;
}

errno_t
mbuf_copydata(const mbuf_t m0, size_t off, size_t len, void *out_data __sized_by_or_null(len))
{
	/* Copied m_copydata, added error handling (don't just panic) */
	size_t count;
	mbuf_t  m = m0;

	if (off >= INT_MAX || len >= INT_MAX) {
		return EINVAL;
	}

	/*
	 * Empty destination buffer is permitted.
	 */
	if (out_data == NULL || len == 0) {
		return 0;
	}

	while (off > 0) {
		if (m == 0) {
			return EINVAL;
		}
		if (off < (size_t)m->m_len) {
			break;
		}
		off -= m->m_len;
		m = m->m_next;
	}
	while (len > 0) {
		if (m == 0) {
			return EINVAL;
		}
		count = m->m_len - off > len ? len : m->m_len - off;
		bcopy(mtod(m, caddr_t) + off, out_data, count);
		len -= count;
		out_data = ((char *)out_data) + count;
		off = 0;
		m = m->m_next;
	}

	return 0;
}

int
mbuf_mclhasreference(mbuf_t mbuf)
{
	if ((mbuf->m_flags & M_EXT)) {
		return m_mclhasreference(mbuf);
	} else {
		return 0;
	}
}


/* mbuf header */
mbuf_t
mbuf_next(const mbuf_t mbuf)
{
	return mbuf->m_next;
}

errno_t
mbuf_setnext(mbuf_t mbuf, mbuf_t next)
{
	if (next && ((next)->m_nextpkt != NULL ||
	    (next)->m_type == MT_FREE)) {
		return EINVAL;
	}
	mbuf->m_next = next;

	return 0;
}

mbuf_t
mbuf_nextpkt(const mbuf_t mbuf)
{
	return mbuf->m_nextpkt;
}

void
mbuf_setnextpkt(mbuf_t mbuf, mbuf_t nextpkt)
{
	mbuf->m_nextpkt = nextpkt;
}

size_t
mbuf_len(const mbuf_t mbuf)
{
	return mbuf->m_len;
}

void
mbuf_setlen(mbuf_t mbuf, size_t len)
{
	mbuf->m_len = (int32_t)len;
}

size_t
mbuf_maxlen(const mbuf_t mbuf)
{
	if (mbuf->m_flags & M_EXT) {
		return mbuf->m_ext.ext_size;
	}
	return &mbuf->m_dat[MLEN] - ((char *)mbuf_datastart(mbuf));
}

mbuf_type_t
mbuf_type(const mbuf_t mbuf)
{
	return mbuf->m_type;
}

errno_t
mbuf_settype(mbuf_t mbuf, mbuf_type_t new_type)
{
	if (new_type == MBUF_TYPE_FREE) {
		return EINVAL;
	}

	m_mchtype(mbuf, new_type);

	return 0;
}

mbuf_flags_t
mbuf_flags(const mbuf_t mbuf)
{
	return mbuf->m_flags & mbuf_flags_mask;
}

errno_t
mbuf_setflags(mbuf_t mbuf, mbuf_flags_t flags)
{
	errno_t ret = 0;
	mbuf_flags_t oflags = mbuf->m_flags;

	/*
	 * 1. Return error if public but un-alterable flags are changed
	 *    in flags argument.
	 * 2. Return error if bits other than public flags are set in passed
	 *    flags argument.
	 *    Please note that private flag bits must be passed as reset by
	 *    kexts, as they must use mbuf_flags KPI to get current set of
	 *    mbuf flags and mbuf_flags KPI does not expose private flags.
	 */
	if ((flags ^ oflags) & mbuf_cflags_mask) {
		ret = EINVAL;
	} else if (flags & ~mbuf_flags_mask) {
		ret = EINVAL;
	} else {
		mbuf->m_flags = (uint16_t)flags | (mbuf->m_flags & ~mbuf_flags_mask);
		/*
		 * If M_PKTHDR bit has changed, we have work to do;
		 * m_reinit() will take care of setting/clearing the
		 * bit, as well as the rest of bookkeeping.
		 */
		if ((oflags ^ mbuf->m_flags) & M_PKTHDR) {
			mbuf->m_flags ^= M_PKTHDR;      /* restore */
			ret = m_reinit(mbuf,
			    (mbuf->m_flags & M_PKTHDR) ? 0 : 1);
		}
	}

	return ret;
}

errno_t
mbuf_setflags_mask(mbuf_t mbuf, mbuf_flags_t flags, mbuf_flags_t mask)
{
	errno_t ret = 0;

	if (mask & (~mbuf_flags_mask | mbuf_cflags_mask)) {
		ret = EINVAL;
	} else {
		mbuf_flags_t oflags = mbuf->m_flags;
		mbuf->m_flags = (uint16_t)((flags & mask) | (mbuf->m_flags & ~mask));
		/*
		 * If M_PKTHDR bit has changed, we have work to do;
		 * m_reinit() will take care of setting/clearing the
		 * bit, as well as the rest of bookkeeping.
		 */
		if ((oflags ^ mbuf->m_flags) & M_PKTHDR) {
			mbuf->m_flags ^= M_PKTHDR;      /* restore */
			ret = m_reinit(mbuf,
			    (mbuf->m_flags & M_PKTHDR) ? 0 : 1);
		}
	}

	return ret;
}

errno_t
mbuf_copy_pkthdr(mbuf_t dest, const mbuf_t src)
{
	if (((src)->m_flags & M_PKTHDR) == 0) {
		return EINVAL;
	}

	m_copy_pkthdr(dest, src);

	return 0;
}

size_t
mbuf_pkthdr_len(const mbuf_t mbuf)
{
	if (((mbuf)->m_flags & M_PKTHDR) == 0) {
		return 0;
	}
	/*
	 * While we Assert for development or debug builds,
	 * also make sure we never return negative length
	 * for release build.
	 */
	ASSERT(mbuf->m_pkthdr.len >= 0);
	if (mbuf->m_pkthdr.len < 0) {
		return 0;
	}
	return mbuf->m_pkthdr.len;
}

__private_extern__ size_t
mbuf_pkthdr_maxlen(mbuf_t m)
{
	size_t maxlen = 0;
	mbuf_t n = m;

	while (n) {
		maxlen += mbuf_maxlen(n);
		n = mbuf_next(n);
	}
	return maxlen;
}

void
mbuf_pkthdr_setlen(mbuf_t mbuf, size_t len)
{
	if (len > INT32_MAX) {
		len = INT32_MAX;
	}

	mbuf->m_pkthdr.len = (int)len;
}

void
mbuf_pkthdr_adjustlen(mbuf_t mbuf, int amount)
{
	mbuf->m_pkthdr.len += amount;
}

ifnet_t
mbuf_pkthdr_rcvif(const mbuf_t mbuf)
{
	/*
	 * If we reference count ifnets, we should take a reference here
	 * before returning
	 */
	return mbuf->m_pkthdr.rcvif;
}

errno_t
mbuf_pkthdr_setrcvif(mbuf_t mbuf, ifnet_t ifnet)
{
	/* May want to walk ifnet list to determine if interface is valid */
	mbuf->m_pkthdr.rcvif = (struct ifnet *)ifnet;
	return 0;
}

void*
mbuf_pkthdr_header(const mbuf_t mbuf)
{
	return mbuf->m_pkthdr.pkt_hdr;
}

void
mbuf_pkthdr_setheader(mbuf_t mbuf, void *header)
{
	mbuf->m_pkthdr.pkt_hdr = (void*)header;
}

void
mbuf_inbound_modified(mbuf_t mbuf)
{
	/* Invalidate hardware generated checksum flags */
	mbuf->m_pkthdr.csum_flags = 0;
}

void
mbuf_outbound_finalize(struct mbuf *m, u_int32_t pf, size_t o)
{
	/* Generate the packet in software, client needs it */
	switch (pf) {
	case PF_INET:
		(void) in_finalize_cksum(m, (uint32_t)o, m->m_pkthdr.csum_flags);
		break;

	case PF_INET6:
		/*
		 * Checksum offload should not have been enabled when
		 * extension headers exist; indicate that the callee
		 * should skip such case by setting optlen to -1.
		 */
		(void) in6_finalize_cksum(m, (uint32_t)o, -1, -1, m->m_pkthdr.csum_flags);
		break;

	default:
		break;
	}
}

errno_t
mbuf_set_vlan_tag(
	mbuf_t mbuf,
	u_int16_t vlan)
{
	mbuf->m_pkthdr.csum_flags |= CSUM_VLAN_TAG_VALID;
	mbuf->m_pkthdr.vlan_tag = vlan;

	return 0;
}

errno_t
mbuf_get_vlan_tag(
	mbuf_t mbuf,
	u_int16_t *vlan)
{
	if ((mbuf->m_pkthdr.csum_flags & CSUM_VLAN_TAG_VALID) == 0) {
		return ENXIO; // No vlan tag set
	}
	*vlan = mbuf->m_pkthdr.vlan_tag;

	return 0;
}

errno_t
mbuf_clear_vlan_tag(
	mbuf_t mbuf)
{
	mbuf->m_pkthdr.csum_flags &= ~CSUM_VLAN_TAG_VALID;
	mbuf->m_pkthdr.vlan_tag = 0;

	return 0;
}

static const mbuf_csum_request_flags_t mbuf_valid_csum_request_flags =
    MBUF_CSUM_REQ_IP | MBUF_CSUM_REQ_TCP | MBUF_CSUM_REQ_UDP |
    MBUF_CSUM_PARTIAL | MBUF_CSUM_REQ_TCPIPV6 | MBUF_CSUM_REQ_UDPIPV6;

errno_t
mbuf_set_csum_requested(
	mbuf_t mbuf,
	mbuf_csum_request_flags_t request,
	u_int32_t value)
{
	request &= mbuf_valid_csum_request_flags;
	mbuf->m_pkthdr.csum_flags =
	    (mbuf->m_pkthdr.csum_flags & 0xffff0000) | request;
	mbuf->m_pkthdr.csum_data = value;

	return 0;
}

static const mbuf_tso_request_flags_t mbuf_valid_tso_request_flags =
    MBUF_TSO_IPV4 | MBUF_TSO_IPV6;

errno_t
mbuf_get_tso_requested(
	mbuf_t mbuf,
	mbuf_tso_request_flags_t *request,
	u_int32_t *mss)
{
	if (mbuf == NULL || (mbuf->m_flags & M_PKTHDR) == 0 ||
	    request == NULL || mss == NULL) {
		return EINVAL;
	}

	*request = mbuf->m_pkthdr.csum_flags;
	*request &= mbuf_valid_tso_request_flags;
	if (*request != 0) {
		*mss = mbuf->m_pkthdr.tx_seg_size;
	}

	return 0;
}

static inline mbuf_gso_type_t
gso_type_from_tso_request_flags(mbuf_tso_request_flags_t flags)
{
	mbuf_gso_type_t type = MBUF_GSO_TYPE_NONE;

	if ((flags & MBUF_TSO_IPV4) != 0) {
		type = MBUF_GSO_TYPE_IPV4;
	} else if ((flags & MBUF_TSO_IPV6) != 0) {
		type = MBUF_GSO_TYPE_IPV6;
	}
	return type;
}

errno_t
mbuf_get_gso_info(
	mbuf_t mbuf,
	mbuf_gso_type_t *type,
	uint16_t *ret_seg_size,
	uint16_t *ret_hdr_len)
{
	mbuf_tso_request_flags_t flags;
	uint16_t       hdr_len = 0;
	uint16_t       seg_size = 0;

	if (mbuf == NULL || (mbuf->m_flags & M_PKTHDR) == 0 ||
	    type == NULL || ret_seg_size == NULL || ret_hdr_len == NULL) {
		return EINVAL;
	}
	flags = mbuf->m_pkthdr.csum_flags & mbuf_valid_tso_request_flags;
	if (flags != 0) {
		seg_size = mbuf->m_pkthdr.tx_seg_size;
		hdr_len = mbuf->m_pkthdr.tx_hdr_len;
	}
	*type = gso_type_from_tso_request_flags(flags);
	*ret_seg_size = seg_size;
	*ret_hdr_len = hdr_len;
	return 0;
}

errno_t
mbuf_set_gso_info(
	mbuf_t mbuf,
	mbuf_gso_type_t type,
	uint16_t seg_size,
	uint16_t hdr_len)
{
	errno_t         error = EINVAL;
	mbuf_tso_request_flags_t flags = 0;

	if (mbuf == NULL || (mbuf->m_flags & M_PKTHDR) == 0) {
		goto done;
	}
	switch (type) {
	case MBUF_GSO_TYPE_NONE:
		break;
	case MBUF_GSO_TYPE_IPV4:
		flags = MBUF_TSO_IPV4;
		break;
	case MBUF_GSO_TYPE_IPV6:
		flags = MBUF_TSO_IPV6;
		break;
	default:
		/* unsupported type */
		goto done;
	}
	switch (flags) {
	case 0:
		/* clearing GSO, seg_size and hdr_len must be zero */
		if (seg_size != 0 || hdr_len != 0) {
			goto done;
		}
		mbuf->m_pkthdr.csum_flags &= ~mbuf_valid_tso_request_flags;
		mbuf->m_pkthdr.tx_seg_size = 0;
		mbuf->m_pkthdr.tx_hdr_len = 0;
		error = 0;
		break;
	default:
		if (seg_size == 0) {
			/* must specify seg_size */
			goto done;
		}
		mbuf->m_pkthdr.csum_flags |= flags;
		mbuf->m_pkthdr.tx_seg_size = seg_size;
		mbuf->m_pkthdr.tx_hdr_len = hdr_len;
		error = 0;
		break;
	}
done:
	return error;
}

errno_t
mbuf_get_lro_info(
	mbuf_t mbuf,
	uint8_t * seg_cnt,
	uint8_t * dup_ack_cnt)
{
	errno_t         error = EINVAL;

	if (mbuf == NULL || (mbuf->m_flags & M_PKTHDR) == 0) {
		goto done;
	}
	if (seg_cnt == NULL || dup_ack_cnt == NULL) {
		goto done;
	}
	*seg_cnt = mbuf->m_pkthdr.rx_seg_cnt;
	*dup_ack_cnt = 0;
	error = 0;
done:
	return error;
}

errno_t
mbuf_set_lro_info(
	mbuf_t mbuf,
	uint8_t seg_cnt,
	uint8_t dup_ack_cnt)
{
	errno_t         error = EINVAL;

	if (mbuf == NULL || (mbuf->m_flags & M_PKTHDR) == 0 ||
	    dup_ack_cnt != 0 || seg_cnt == 1) {
		goto done;
	}
	mbuf->m_pkthdr.rx_seg_cnt = seg_cnt;
done:
	return error;
}

errno_t
mbuf_get_csum_requested(
	mbuf_t mbuf,
	mbuf_csum_request_flags_t *request,
	u_int32_t *value)
{
	*request = mbuf->m_pkthdr.csum_flags;
	*request &= mbuf_valid_csum_request_flags;
	if (value != NULL) {
		*value = mbuf->m_pkthdr.csum_data;
	}

	return 0;
}

errno_t
mbuf_clear_csum_requested(
	mbuf_t mbuf)
{
	mbuf->m_pkthdr.csum_flags &= 0xffff0000;
	mbuf->m_pkthdr.csum_data = 0;

	return 0;
}

static const mbuf_csum_performed_flags_t mbuf_valid_csum_performed_flags =
    MBUF_CSUM_DID_IP | MBUF_CSUM_IP_GOOD | MBUF_CSUM_DID_DATA |
    MBUF_CSUM_PSEUDO_HDR | MBUF_CSUM_PARTIAL;

errno_t
mbuf_set_csum_performed(
	mbuf_t mbuf,
	mbuf_csum_performed_flags_t performed,
	u_int32_t value)
{
	performed &= mbuf_valid_csum_performed_flags;
	mbuf->m_pkthdr.csum_flags =
	    (mbuf->m_pkthdr.csum_flags & 0xffff0000) | performed;
	mbuf->m_pkthdr.csum_data = value;

	return 0;
}

errno_t
mbuf_get_csum_performed(
	mbuf_t mbuf,
	mbuf_csum_performed_flags_t *performed,
	u_int32_t *value)
{
	*performed =
	    mbuf->m_pkthdr.csum_flags & mbuf_valid_csum_performed_flags;
	*value = mbuf->m_pkthdr.csum_data;

	return 0;
}

errno_t
mbuf_clear_csum_performed(
	mbuf_t mbuf)
{
	mbuf->m_pkthdr.csum_flags &= 0xffff0000;
	mbuf->m_pkthdr.csum_data = 0;

	return 0;
}

errno_t
mbuf_inet_cksum(mbuf_t mbuf, int protocol, u_int32_t offset, u_int32_t length,
    u_int16_t *csum)
{
	if (mbuf == NULL || length == 0 || csum == NULL ||
	    (u_int32_t)mbuf->m_pkthdr.len < (offset + length)) {
		return EINVAL;
	}

	*csum = inet_cksum(mbuf, protocol, offset, length);
	return 0;
}

errno_t
mbuf_inet6_cksum(mbuf_t mbuf, int protocol, u_int32_t offset, u_int32_t length,
    u_int16_t *csum)
{
	if (mbuf == NULL || length == 0 || csum == NULL ||
	    (u_int32_t)mbuf->m_pkthdr.len < (offset + length)) {
		return EINVAL;
	}

	*csum = inet6_cksum(mbuf, protocol, offset, length);
	return 0;
}

/*
 * Mbuf tag KPIs
 */

#define MTAG_FIRST_ID FIRST_KPI_STR_ID

errno_t
mbuf_tag_id_find(
	const char              *string,
	mbuf_tag_id_t   *out_id)
{
	return net_str_id_find_internal(string, out_id, NSI_MBUF_TAG, 1);
}

errno_t
mbuf_tag_allocate(
	mbuf_t                  mbuf,
	mbuf_tag_id_t   id,
	mbuf_tag_type_t type,
	size_t                  length,
	mbuf_how_t              how,
	void**                  data_p)
{
	struct m_tag *tag;
	u_int32_t mtag_id_first, mtag_id_last;

	if (data_p != NULL) {
		*data_p = NULL;
	}

	/* Sanity check parameters */
	(void) net_str_id_first_last(&mtag_id_first, &mtag_id_last,
	    NSI_MBUF_TAG);
	if (mbuf == NULL || (mbuf->m_flags & M_PKTHDR) == 0 ||
	    id < mtag_id_first || id > mtag_id_last || length < 1 ||
	    (length & 0xffff0000) != 0 || data_p == NULL) {
		return EINVAL;
	}

	/* Make sure this mtag hasn't already been allocated */
	tag = m_tag_locate(mbuf, id, type);
	if (tag != NULL) {
		return EEXIST;
	}

	/* Allocate an mtag */
	tag = m_tag_create(id, type, (int)length, how, mbuf);
	if (tag == NULL) {
		return how == M_WAITOK ? ENOMEM : EWOULDBLOCK;
	}

	/* Attach the mtag and set *data_p */
	m_tag_prepend(mbuf, tag);
	*data_p = tag->m_tag_data;

	return 0;
}

errno_t
mbuf_tag_find(
	mbuf_t mbuf,
	mbuf_tag_id_t id,
	mbuf_tag_type_t type,
	size_t *length,
	void **data_p)
{
	struct m_tag *tag;
	u_int32_t mtag_id_first, mtag_id_last;

	if (length != NULL) {
		*length = 0;
	}
	if (data_p != NULL) {
		*data_p = NULL;
	}

	/* Sanity check parameters */
	(void) net_str_id_first_last(&mtag_id_first, &mtag_id_last,
	    NSI_MBUF_TAG);
	if (mbuf == NULL || (mbuf->m_flags & M_PKTHDR) == 0 ||
	    id < mtag_id_first || id > mtag_id_last || length == NULL ||
	    data_p == NULL) {
		return EINVAL;
	}

	/* Locate an mtag */
	tag = m_tag_locate(mbuf, id, type);
	if (tag == NULL) {
		return ENOENT;
	}

	/* Copy out the pointer to the data and the lenght value */
	*length = tag->m_tag_len;
	*data_p = tag->m_tag_data;

	return 0;
}

void
mbuf_tag_free(
	mbuf_t                  mbuf,
	mbuf_tag_id_t   id,
	mbuf_tag_type_t type)
{
	struct m_tag *tag;
	u_int32_t mtag_id_first, mtag_id_last;

	/* Sanity check parameters */
	(void) net_str_id_first_last(&mtag_id_first, &mtag_id_last,
	    NSI_MBUF_TAG);
	if (mbuf == NULL || (mbuf->m_flags & M_PKTHDR) == 0 ||
	    id < mtag_id_first || id > mtag_id_last) {
		return;
	}

	tag = m_tag_locate(mbuf, id, type);
	if (tag == NULL) {
		return;
	}

	m_tag_delete(mbuf, tag);
}

/*
 * Maximum length of driver auxiliary data; keep this small to
 * fit in a single mbuf to avoid wasting memory, rounded down to
 * the nearest 64-bit boundary.  This takes into account mbuf
 * tag-related (m_taghdr + m_tag) as well m_drvaux_tag structs.
 */
#define MBUF_DRVAUX_MAXLEN                                              \
	P2ROUNDDOWN(MLEN -                                              \
	M_TAG_ALIGN(sizeof (struct m_drvaux_tag)), sizeof (uint64_t))

errno_t
mbuf_add_drvaux(mbuf_t mbuf, mbuf_how_t how, u_int32_t family,
    u_int32_t subfamily, size_t length, void **data_p)
{
	struct m_drvaux_tag *p;
	struct m_tag *tag;

	if (mbuf == NULL || !(mbuf->m_flags & M_PKTHDR) ||
	    length == 0 || length > MBUF_DRVAUX_MAXLEN) {
		return EINVAL;
	}

	if (data_p != NULL) {
		*data_p = NULL;
	}

	/* Check if one is already associated */
	if ((tag = m_tag_locate(mbuf, KERNEL_MODULE_TAG_ID,
	    KERNEL_TAG_TYPE_DRVAUX)) != NULL) {
		return EEXIST;
	}

	/* Tag is (m_drvaux_tag + module specific data) */
	if ((tag = m_tag_create(KERNEL_MODULE_TAG_ID, KERNEL_TAG_TYPE_DRVAUX,
	    (int)(sizeof(*p) + length), how, mbuf)) == NULL) {
		return (how == MBUF_WAITOK) ? ENOMEM : EWOULDBLOCK;
	}

	p = (struct m_drvaux_tag *)(tag->m_tag_data);
	p->da_family = family;
	p->da_subfamily = subfamily;
	p->da_length = (int)length;

	/* Associate the tag */
	m_tag_prepend(mbuf, tag);

	if (data_p != NULL) {
		*data_p = (p + 1);
	}

	return 0;
}

errno_t
mbuf_find_drvaux(mbuf_t mbuf, u_int32_t *family_p, u_int32_t *subfamily_p,
    u_int32_t *length_p, void **data_p)
{
	struct m_drvaux_tag *p;
	struct m_tag *tag;

	if (mbuf == NULL || !(mbuf->m_flags & M_PKTHDR) || data_p == NULL) {
		return EINVAL;
	}

	*data_p = NULL;

	if ((tag = m_tag_locate(mbuf, KERNEL_MODULE_TAG_ID,
	    KERNEL_TAG_TYPE_DRVAUX)) == NULL) {
		return ENOENT;
	}

	/* Must be at least size of m_drvaux_tag */
	VERIFY(tag->m_tag_len >= sizeof(*p));

	p = (struct m_drvaux_tag *)(tag->m_tag_data);
	VERIFY(p->da_length > 0 && p->da_length <= MBUF_DRVAUX_MAXLEN);

	if (family_p != NULL) {
		*family_p = p->da_family;
	}
	if (subfamily_p != NULL) {
		*subfamily_p = p->da_subfamily;
	}
	if (length_p != NULL) {
		*length_p = p->da_length;
	}

	*data_p = (p + 1);

	return 0;
}

void
mbuf_del_drvaux(mbuf_t mbuf)
{
	struct m_tag *tag;

	if (mbuf == NULL || !(mbuf->m_flags & M_PKTHDR)) {
		return;
	}

	if ((tag = m_tag_locate(mbuf, KERNEL_MODULE_TAG_ID,
	    KERNEL_TAG_TYPE_DRVAUX)) != NULL) {
		m_tag_delete(mbuf, tag);
	}
}

/* mbuf stats */
void
mbuf_stats(struct mbuf_stat *stats)
{
	stats->mbufs = mbstat.m_mbufs;
	stats->clusters = mbstat.m_clusters;
	stats->clfree = mbstat.m_clfree;
	stats->drops = mbstat.m_drops;
	stats->wait = mbstat.m_wait;
	stats->drain = mbstat.m_drain;
	__builtin_memcpy(stats->mtypes, mbstat.m_mtypes, sizeof(stats->mtypes));
	stats->mcfail = mbstat.m_mcfail;
	stats->mpfail = mbstat.m_mpfail;
	stats->msize = mbstat.m_msize;
	stats->mclbytes = mbstat.m_mclbytes;
	stats->minclsize = mbstat.m_minclsize;
	stats->mlen = mbstat.m_mlen;
	stats->mhlen = mbstat.m_mhlen;
	stats->bigclusters = mbstat.m_bigclusters;
	stats->bigclfree = mbstat.m_bigclfree;
	stats->bigmclbytes = mbstat.m_bigmclbytes;
}

errno_t
mbuf_allocpacket(mbuf_how_t how, size_t packetlen, unsigned int *maxchunks,
    mbuf_t *mbuf)
{
	errno_t error = 0;
	struct mbuf *m;
	unsigned int numpkts = 1;
	unsigned int numchunks = maxchunks != NULL ? *maxchunks : 0;

	if (packetlen == 0) {
		error = EINVAL;
		os_log(OS_LOG_DEFAULT, "mbuf_allocpacket %d", __LINE__);
		goto out;
	}
	m = m_allocpacket_internal(&numpkts, packetlen,
	    maxchunks != NULL ? &numchunks : NULL, how, 1, 0);
	if (m == NULL) {
		if (maxchunks != NULL && *maxchunks && numchunks > *maxchunks) {
			error = ENOBUFS;
			os_log(OS_LOG_DEFAULT, "mbuf_allocpacket %d", __LINE__);
		} else {
			error = ENOMEM;
			os_log(OS_LOG_DEFAULT, "mbuf_allocpacket %d", __LINE__);
		}
	} else {
		if (maxchunks != NULL) {
			*maxchunks = numchunks;
		}
		error = 0;
		*mbuf = m;
	}
out:
	return error;
}

errno_t
mbuf_allocpacket_list(unsigned int numpkts, mbuf_how_t how, size_t packetlen,
    unsigned int *maxchunks, mbuf_t *mbuf)
{
	errno_t error = 0;
	struct mbuf *m;
	unsigned int numchunks = maxchunks ? *maxchunks : 0;

	if (numpkts == 0) {
		error = EINVAL;
		goto out;
	}
	if (packetlen == 0) {
		error = EINVAL;
		goto out;
	}
	m = m_allocpacket_internal(&numpkts, packetlen,
	    maxchunks != NULL ? &numchunks : NULL, how, 1, 0);
	if (m == NULL) {
		if (maxchunks != NULL && *maxchunks && numchunks > *maxchunks) {
			error = ENOBUFS;
		} else {
			error = ENOMEM;
		}
	} else {
		if (maxchunks != NULL) {
			*maxchunks = numchunks;
		}
		error = 0;
		*mbuf = m;
	}
out:
	return error;
}

__private_extern__ size_t
mbuf_pkt_list_len(mbuf_t m)
{
	size_t len = 0;
	mbuf_t n = m;

	while (n) {
		len += mbuf_pkthdr_len(n);
		n = mbuf_nextpkt(n);
	}
	return len;
}

__private_extern__ size_t
mbuf_pkt_list_maxlen(mbuf_t m)
{
	size_t maxlen = 0;
	mbuf_t n = m;

	while (n) {
		maxlen += mbuf_pkthdr_maxlen(n);
		n = mbuf_nextpkt(n);
	}
	return maxlen;
}

/*
 * mbuf_copyback differs from m_copyback in a few ways:
 * 1) mbuf_copyback will allocate clusters for new mbufs we append
 * 2) mbuf_copyback will grow the last mbuf in the chain if possible
 * 3) mbuf_copyback reports whether or not the operation succeeded
 * 4) mbuf_copyback allows the caller to specify M_WAITOK or M_NOWAIT
 */
errno_t
mbuf_copyback(
	mbuf_t          m,
	size_t          off,
	size_t          len0,
	const void      *data __sized_by_or_null(len0),
	mbuf_how_t      how)
{
	size_t  mlen, len = len0;
	mbuf_ref_t  m_start = m;
	mbuf_ref_t  n;
	int             totlen = 0;
	errno_t         result = 0;
	const char      *cp = data;

	if (m == NULL || len == 0 || data == NULL) {
		return EINVAL;
	}

	while (off > (mlen = m->m_len)) {
		off -= mlen;
		totlen += mlen;
		if (m->m_next == 0) {
			n = m_getclr(how, m->m_type);
			if (n == 0) {
				result = ENOBUFS;
				goto out;
			}
			n->m_len = (int32_t)MIN(MLEN, len + off);
			m->m_next = n;
		}
		m = m->m_next;
	}

	while (len > 0) {
		mlen = MIN(m->m_len - off, len);
		if (mlen < len && m->m_next == NULL &&
		    mbuf_trailingspace(m) > 0) {
			size_t  grow = MIN(mbuf_trailingspace(m), len - mlen);
			mlen += grow;
			m->m_len += grow;
		}
		bcopy(cp, off + mtod(m, char *), (unsigned)mlen);
		cp += mlen;
		len -= mlen;
		mlen += off;
		off = 0;
		totlen += mlen;
		if (len == 0) {
			break;
		}
		if (m->m_next == 0) {
			n = m_get(how, m->m_type);
			if (n == NULL) {
				result = ENOBUFS;
				goto out;
			}
			if (len > MINCLSIZE) {
				/*
				 * cluster allocation failure is okay,
				 * we can grow chain
				 */
				mbuf_mclget(how, m->m_type, &n);
			}
			n->m_len = (int32_t)MIN(mbuf_maxlen(n), len);
			m->m_next = n;
		}
		m = m->m_next;
	}

out:
	if ((m_start->m_flags & M_PKTHDR) && (m_start->m_pkthdr.len < totlen)) {
		m_start->m_pkthdr.len = totlen;
	}

	return result;
}

u_int32_t
mbuf_get_mlen(void)
{
	return _MLEN;
}

u_int32_t
mbuf_get_mhlen(void)
{
	return _MHLEN;
}

u_int32_t
mbuf_get_minclsize(void)
{
	return MHLEN + MLEN;
}

u_int32_t
mbuf_get_msize(void)
{
	return _MSIZE;
}

u_int32_t
mbuf_get_traffic_class_max_count(void)
{
	return MBUF_TC_MAX;
}

errno_t
mbuf_get_traffic_class_index(mbuf_traffic_class_t tc, u_int32_t *index)
{
	if (index == NULL || (u_int32_t)tc >= MBUF_TC_MAX) {
		return EINVAL;
	}

	*index = MBUF_SCIDX(m_service_class_from_val(MBUF_TC2SCVAL(tc)));
	return 0;
}

mbuf_traffic_class_t
mbuf_get_traffic_class(mbuf_t m)
{
	if (m == NULL || !(m->m_flags & M_PKTHDR)) {
		return MBUF_TC_BE;
	}

	return m_get_traffic_class(m);
}

errno_t
mbuf_set_traffic_class(mbuf_t m, mbuf_traffic_class_t tc)
{
	if (m == NULL || !(m->m_flags & M_PKTHDR) ||
	    ((u_int32_t)tc >= MBUF_TC_MAX)) {
		return EINVAL;
	}

	return m_set_traffic_class(m, tc);
}

int
mbuf_is_traffic_class_privileged(mbuf_t m)
{
	if (m == NULL || !(m->m_flags & M_PKTHDR) ||
	    !MBUF_VALID_SC(m->m_pkthdr.pkt_svc)) {
		return 0;
	}

	return (m->m_pkthdr.pkt_flags & PKTF_PRIO_PRIVILEGED) ? 1 : 0;
}

u_int32_t
mbuf_get_service_class_max_count(void)
{
	return MBUF_SC_MAX_CLASSES;
}

errno_t
mbuf_get_service_class_index(mbuf_svc_class_t sc, u_int32_t *index)
{
	if (index == NULL || !MBUF_VALID_SC(sc)) {
		return EINVAL;
	}

	*index = MBUF_SCIDX(sc);
	return 0;
}

mbuf_svc_class_t
mbuf_get_service_class(mbuf_t m)
{
	if (m == NULL || !(m->m_flags & M_PKTHDR)) {
		return MBUF_SC_BE;
	}

	return m_get_service_class(m);
}

errno_t
mbuf_set_service_class(mbuf_t m, mbuf_svc_class_t sc)
{
	if (m == NULL || !(m->m_flags & M_PKTHDR)) {
		return EINVAL;
	}

	return m_set_service_class(m, sc);
}

errno_t
mbuf_pkthdr_aux_flags(mbuf_t m, mbuf_pkthdr_aux_flags_t *flagsp)
{
	u_int32_t flags;

	if (m == NULL || !(m->m_flags & M_PKTHDR) || flagsp == NULL) {
		return EINVAL;
	}

	*flagsp = 0;
	flags = m->m_pkthdr.pkt_flags;
	if ((flags & (PKTF_INET_RESOLVE | PKTF_RESOLVE_RTR)) ==
	    (PKTF_INET_RESOLVE | PKTF_RESOLVE_RTR)) {
		*flagsp |= MBUF_PKTAUXF_INET_RESOLVE_RTR;
	}
	if ((flags & (PKTF_INET6_RESOLVE | PKTF_RESOLVE_RTR)) ==
	    (PKTF_INET6_RESOLVE | PKTF_RESOLVE_RTR)) {
		*flagsp |= MBUF_PKTAUXF_INET6_RESOLVE_RTR;
	}

	/* These 2 flags are mutually exclusive */
	VERIFY((*flagsp &
	    (MBUF_PKTAUXF_INET_RESOLVE_RTR | MBUF_PKTAUXF_INET6_RESOLVE_RTR)) !=
	    (MBUF_PKTAUXF_INET_RESOLVE_RTR | MBUF_PKTAUXF_INET6_RESOLVE_RTR));

	return 0;
}

errno_t
mbuf_get_driver_scratch(mbuf_t m, u_int8_t **area, size_t *area_len)
{
	if (m == NULL || area == NULL || area_len == NULL ||
	    !(m->m_flags & M_PKTHDR)) {
		return EINVAL;
	}

	*area_len = m_scratch_get(m, area);
	return 0;
}

errno_t
mbuf_get_unsent_data_bytes(const mbuf_t m, u_int32_t *unsent_data)
{
	if (m == NULL || unsent_data == NULL || !(m->m_flags & M_PKTHDR)) {
		return EINVAL;
	}

	if (!(m->m_pkthdr.pkt_flags & PKTF_VALID_UNSENT_DATA)) {
		return EINVAL;
	}

	*unsent_data = m->m_pkthdr.bufstatus_if +
	    m->m_pkthdr.bufstatus_sndbuf;
	return 0;
}

errno_t
mbuf_get_buffer_status(const mbuf_t m, mbuf_buffer_status_t *buf_status)
{
	if (m == NULL || buf_status == NULL || !(m->m_flags & M_PKTHDR) ||
	    !(m->m_pkthdr.pkt_flags & PKTF_VALID_UNSENT_DATA)) {
		return EINVAL;
	}

	buf_status->buf_interface = m->m_pkthdr.bufstatus_if;
	buf_status->buf_sndbuf = m->m_pkthdr.bufstatus_sndbuf;
	return 0;
}

errno_t
mbuf_pkt_new_flow(const mbuf_t m, u_int32_t *retval)
{
	if (m == NULL || retval == NULL || !(m->m_flags & M_PKTHDR)) {
		return EINVAL;
	}
	if (m->m_pkthdr.pkt_flags & PKTF_NEW_FLOW) {
		*retval = 1;
	} else {
		*retval = 0;
	}
	return 0;
}

errno_t
mbuf_last_pkt(const mbuf_t m, u_int32_t *retval)
{
	if (m == NULL || retval == NULL || !(m->m_flags & M_PKTHDR)) {
		return EINVAL;
	}
	if (m->m_pkthdr.pkt_flags & PKTF_LAST_PKT) {
		*retval = 1;
	} else {
		*retval = 0;
	}
	return 0;
}

errno_t
mbuf_get_timestamp(mbuf_t m, u_int64_t *ts, boolean_t *valid)
{
	if (m == NULL || !(m->m_flags & M_PKTHDR) || ts == NULL) {
		return EINVAL;
	}

	if ((m->m_pkthdr.pkt_flags & PKTF_TS_VALID) == 0) {
		if (valid != NULL) {
			*valid = FALSE;
		}
		*ts = 0;
	} else {
		if (valid != NULL) {
			*valid = TRUE;
		}
		*ts = m->m_pkthdr.pkt_timestamp;
	}
	return 0;
}

errno_t
mbuf_set_timestamp(mbuf_t m, u_int64_t ts, boolean_t valid)
{
	if (m == NULL || !(m->m_flags & M_PKTHDR)) {
		return EINVAL;
	}

	if (valid == FALSE) {
		m->m_pkthdr.pkt_flags &= ~PKTF_TS_VALID;
		m->m_pkthdr.pkt_timestamp = 0;
	} else {
		m->m_pkthdr.pkt_flags |= PKTF_TS_VALID;
		m->m_pkthdr.pkt_timestamp = ts;
	}
	return 0;
}

errno_t
mbuf_get_status(mbuf_t m, kern_return_t *status)
{
	if (m == NULL || !(m->m_flags & M_PKTHDR) || status == NULL) {
		return EINVAL;
	}

	if ((m->m_pkthdr.pkt_flags & PKTF_DRIVER_MTAG) == 0) {
		*status = 0;
	} else {
		*status = m->m_pkthdr.drv_tx_status;
	}
	return 0;
}

static void
driver_mtag_init(mbuf_t m)
{
	if ((m->m_pkthdr.pkt_flags & PKTF_DRIVER_MTAG) == 0) {
		m->m_pkthdr.pkt_flags |= PKTF_DRIVER_MTAG;
		bzero(&m->m_pkthdr.driver_mtag,
		    sizeof(m->m_pkthdr.driver_mtag));
	}
}

errno_t
mbuf_set_status(mbuf_t m, kern_return_t status)
{
	if (m == NULL || !(m->m_flags & M_PKTHDR)) {
		return EINVAL;
	}

	driver_mtag_init(m);

	m->m_pkthdr.drv_tx_status = status;

	return 0;
}

errno_t
mbuf_get_flowid(mbuf_t m, u_int16_t *flowid)
{
	if (m == NULL || !(m->m_flags & M_PKTHDR) || flowid == NULL) {
		return EINVAL;
	}

	if ((m->m_pkthdr.pkt_flags & PKTF_DRIVER_MTAG) == 0) {
		*flowid = 0;
	} else {
		*flowid = m->m_pkthdr.drv_flowid;
	}
	return 0;
}

errno_t
mbuf_set_flowid(mbuf_t m, u_int16_t flowid)
{
	if (m == NULL || !(m->m_flags & M_PKTHDR)) {
		return EINVAL;
	}

	driver_mtag_init(m);

	m->m_pkthdr.drv_flowid = flowid;

	return 0;
}

errno_t
mbuf_get_tx_compl_data(mbuf_t m, uintptr_t *arg, uintptr_t *data)
{
	if (m == NULL || !(m->m_flags & M_PKTHDR) || arg == NULL ||
	    data == NULL) {
		return EINVAL;
	}

	if ((m->m_pkthdr.pkt_flags & PKTF_DRIVER_MTAG) == 0) {
		*arg = 0;
		*data = 0;
	} else {
		*arg = m->m_pkthdr.drv_tx_compl_arg;
		*data = m->m_pkthdr.drv_tx_compl_data;
	}
	return 0;
}

errno_t
mbuf_set_tx_compl_data(mbuf_t m, uintptr_t arg, uintptr_t data)
{
	if (m == NULL || !(m->m_flags & M_PKTHDR)) {
		return EINVAL;
	}

	driver_mtag_init(m);

	m->m_pkthdr.drv_tx_compl_arg = arg;
	m->m_pkthdr.drv_tx_compl_data = data;

	return 0;
}

static u_int32_t
get_tx_compl_callback_index_locked(mbuf_tx_compl_func callback)
{
	u_int32_t i;

	for (i = 0; i < MAX_MBUF_TX_COMPL_FUNC; i++) {
		if (mbuf_tx_compl_table[i] == callback) {
			return i;
		}
	}
	return UINT32_MAX;
}

static u_int32_t
get_tx_compl_callback_index(mbuf_tx_compl_func callback)
{
	u_int32_t i;

	lck_rw_lock_shared(&mbuf_tx_compl_tbl_lock);

	i = get_tx_compl_callback_index_locked(callback);

	lck_rw_unlock_shared(&mbuf_tx_compl_tbl_lock);

	return i;
}

mbuf_tx_compl_func
m_get_tx_compl_callback(u_int32_t idx)
{
	mbuf_tx_compl_func cb;

	if (idx >= MAX_MBUF_TX_COMPL_FUNC) {
		ASSERT(0);
		return NULL;
	}
	lck_rw_lock_shared(&mbuf_tx_compl_tbl_lock);
	cb = mbuf_tx_compl_table[idx];
	lck_rw_unlock_shared(&mbuf_tx_compl_tbl_lock);
	return cb;
}

errno_t
mbuf_register_tx_compl_callback(mbuf_tx_compl_func callback)
{
	int i;
	errno_t error;

	if (callback == NULL) {
		return EINVAL;
	}

	lck_rw_lock_exclusive(&mbuf_tx_compl_tbl_lock);

	i = get_tx_compl_callback_index_locked(callback);
	if (i != -1) {
		error = EEXIST;
		goto unlock;
	}

	/* assume the worst */
	error = ENOSPC;
	for (i = 0; i < MAX_MBUF_TX_COMPL_FUNC; i++) {
		if (mbuf_tx_compl_table[i] == NULL) {
			mbuf_tx_compl_table[i] = callback;
			error = 0;
			goto unlock;
		}
	}
unlock:
	lck_rw_unlock_exclusive(&mbuf_tx_compl_tbl_lock);

	return error;
}

errno_t
mbuf_unregister_tx_compl_callback(mbuf_tx_compl_func callback)
{
	int i;
	errno_t error;

	if (callback == NULL) {
		return EINVAL;
	}

	lck_rw_lock_exclusive(&mbuf_tx_compl_tbl_lock);

	/* assume the worst */
	error = ENOENT;
	for (i = 0; i < MAX_MBUF_TX_COMPL_FUNC; i++) {
		if (mbuf_tx_compl_table[i] == callback) {
			mbuf_tx_compl_table[i] = NULL;
			error = 0;
			goto unlock;
		}
	}
unlock:
	lck_rw_unlock_exclusive(&mbuf_tx_compl_tbl_lock);

	return error;
}

errno_t
mbuf_get_timestamp_requested(mbuf_t m, boolean_t *requested)
{
	if (m == NULL || !(m->m_flags & M_PKTHDR)) {
		return EINVAL;
	}

	if ((m->m_pkthdr.pkt_flags & PKTF_TX_COMPL_TS_REQ) == 0) {
		*requested = FALSE;
	} else {
		*requested = TRUE;
	}
	return 0;
}

errno_t
mbuf_set_timestamp_requested(mbuf_t m, uintptr_t *pktid,
    mbuf_tx_compl_func callback)
{
	uint32_t i;

	if (m == NULL || !(m->m_flags & M_PKTHDR) || callback == NULL ||
	    pktid == NULL) {
		return EINVAL;
	}

	i = get_tx_compl_callback_index(callback);
	if (i == UINT32_MAX) {
		return ENOENT;
	}

	m_add_crumb(m, PKT_CRUMB_TS_COMP_REQ);

	if ((m->m_pkthdr.pkt_flags & PKTF_TX_COMPL_TS_REQ) == 0) {
		m->m_pkthdr.pkt_compl_callbacks = 0;
		m->m_pkthdr.pkt_flags |= PKTF_TX_COMPL_TS_REQ;
		m->m_pkthdr.pkt_compl_context =
		    os_atomic_inc_orig(&mbuf_tx_compl_index, relaxed);

#if (DEBUG || DEVELOPMENT)
		os_atomic_inc(&mbuf_tx_compl_requested, relaxed);
#endif /* (DEBUG || DEVELOPMENT) */
	}
	m->m_pkthdr.pkt_compl_callbacks |= (1 << i);
	*pktid = m->m_pkthdr.pkt_compl_context;

	return 0;
}

void
m_do_tx_compl_callback(struct mbuf *m, struct ifnet *ifp)
{
	int i;

	if (m == NULL) {
		return;
	}

	if ((m->m_pkthdr.pkt_flags & PKTF_TX_COMPL_TS_REQ) == 0) {
		return;
	}

	m_add_crumb(m, PKT_CRUMB_TS_COMP_CB);

#if (DEBUG || DEVELOPMENT)
	if (mbuf_tx_compl_debug != 0 && ifp != NULL &&
	    (ifp->if_xflags & IFXF_TIMESTAMP_ENABLED) != 0 &&
	    (m->m_pkthdr.pkt_flags & PKTF_TS_VALID) == 0) {
		struct timespec now;

		nanouptime(&now);
		net_timernsec(&now, &m->m_pkthdr.pkt_timestamp);
	}
#endif /* (DEBUG || DEVELOPMENT) */

	for (i = 0; i < MAX_MBUF_TX_COMPL_FUNC; i++) {
		mbuf_tx_compl_func callback;

		if ((m->m_pkthdr.pkt_compl_callbacks & (1 << i)) == 0) {
			continue;
		}

		lck_rw_lock_shared(&mbuf_tx_compl_tbl_lock);
		callback = mbuf_tx_compl_table[i];
		lck_rw_unlock_shared(&mbuf_tx_compl_tbl_lock);

		if (callback != NULL) {
			callback(m->m_pkthdr.pkt_compl_context,
			    ifp,
			    (m->m_pkthdr.pkt_flags & PKTF_TS_VALID) ?
			    m->m_pkthdr.pkt_timestamp: 0,
			    m->m_pkthdr.drv_tx_compl_arg,
			    m->m_pkthdr.drv_tx_compl_data,
			    m->m_pkthdr.drv_tx_status);
		}
	}
#if (DEBUG || DEVELOPMENT)
	if (m->m_pkthdr.pkt_compl_callbacks != 0) {
		os_atomic_inc(&mbuf_tx_compl_callbacks, relaxed);
		if (ifp == NULL) {
			os_atomic_inc(&mbuf_tx_compl_aborted, relaxed);
		}
	}
#endif /* (DEBUG || DEVELOPMENT) */
	m->m_pkthdr.pkt_compl_callbacks = 0;
}

errno_t
mbuf_get_keepalive_flag(mbuf_t m, boolean_t *is_keepalive)
{
	if (m == NULL || is_keepalive == NULL || !(m->m_flags & M_PKTHDR)) {
		return EINVAL;
	}

	*is_keepalive = (m->m_pkthdr.pkt_flags & PKTF_KEEPALIVE);

	return 0;
}

errno_t
mbuf_set_keepalive_flag(mbuf_t m, boolean_t is_keepalive)
{
	if (m == NULL || !(m->m_flags & M_PKTHDR)) {
		return EINVAL;
	}

	if (is_keepalive) {
		m->m_pkthdr.pkt_flags |= PKTF_KEEPALIVE;
	} else {
		m->m_pkthdr.pkt_flags &= ~PKTF_KEEPALIVE;
	}

	return 0;
}

errno_t
mbuf_get_wake_packet_flag(mbuf_t m, boolean_t *is_wake_packet)
{
	if (m == NULL || is_wake_packet == NULL || !(m->m_flags & M_PKTHDR)) {
		return EINVAL;
	}

	*is_wake_packet = (m->m_pkthdr.pkt_flags & PKTF_WAKE_PKT);

	return 0;
}

errno_t
mbuf_set_wake_packet_flag(mbuf_t m, boolean_t is_wake_packet)
{
	if (m == NULL || !(m->m_flags & M_PKTHDR)) {
		return EINVAL;
	}

	if (is_wake_packet) {
		m->m_pkthdr.pkt_flags |= PKTF_WAKE_PKT;
	} else {
		m->m_pkthdr.pkt_flags &= ~PKTF_WAKE_PKT;
	}

	return 0;
}