/*
- * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2000-2018 Apple Inc. All rights reserved.
*
- * @APPLE_LICENSE_HEADER_START@
+ * @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. Please obtain a copy of the License at
- * http://www.opensource.apple.com/apsl/ and read it before using this
- * file.
+ * 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
* Please see the License for the specific language governing rights and
* limitations under the License.
*
- * @APPLE_LICENSE_HEADER_END@
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
*/
/* $NetBSD: uipc_mbuf.c,v 1.40 1999/04/01 00:23:25 thorpej Exp $ */
*
* @(#)uipc_mbuf.c 8.4 (Berkeley) 2/14/95
*/
+/*
+ * NOTICE: This file was modified by SPARTA, Inc. in 2005 to introduce
+ * support for mandatory and extensible security protections. This notice
+ * is included in support of clause 2.2 (b) of the Apple Public License,
+ * Version 2.0.
+ */
/*#define PULLDOWN_DEBUG*/
#include <sys/proc_internal.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
-#if defined(PULLDOWN_STAT) && defined(INET6)
+#include <sys/mcache.h>
#include <netinet/in.h>
+#include <netinet/ip_var.h>
+#if INET6
#include <netinet/ip6.h>
#include <netinet6/ip6_var.h>
+#endif /* INET6 */
+
+#if CONFIG_MACF_NET
+#include <security/mac_framework.h>
#endif
/*
* XXX M_TRAILINGSPACE/M_LEADINGSPACE on shared cluster (sharedcluster)
*/
struct mbuf *
-m_pulldown(m, off, len, offp)
- struct mbuf *m;
- int off, len;
- int *offp;
+m_pulldown(struct mbuf *m, int off, int len, int *offp)
{
- struct mbuf *n, *o;
- int hlen, tlen, olen;
- int sharedcluster;
-#if defined(PULLDOWN_STAT) && defined(INET6)
+ struct mbuf *n = NULL, *o = NULL;
+ int hlen = 0, tlen = 0, olen = 0;
+ int sharedcluster = 0;
+#if defined(PULLDOWN_STAT) && INET6
static struct mbuf *prev = NULL;
int prevlen = 0, prevmlen = 0;
#endif
return NULL; /* impossible */
}
-#if defined(PULLDOWN_STAT) && defined(INET6)
+#if defined(PULLDOWN_STAT) && INET6
ip6stat.ip6s_pulldown++;
#endif
-#if defined(PULLDOWN_STAT) && defined(INET6)
+#if defined(PULLDOWN_STAT) && INET6
/* statistics for m_pullup */
ip6stat.ip6s_pullup++;
if (off + len > MHLEN)
}
#endif
n = m;
+
+ /*
+ * Iterate and make n point to the mbuf
+ * within which the first byte at length
+ * offset is contained from the start of
+ * mbuf chain.
+ */
while (n != NULL && off > 0) {
if (n->m_len > off)
break;
off -= n->m_len;
n = n->m_next;
}
+
/* be sure to point non-empty mbuf */
while (n != NULL && n->m_len == 0)
n = n->m_next;
+
if (!n) {
m_freem(m);
return NULL; /* mbuf chain too short */
/*
* the target data is on <n, off>.
* if we got enough data on the mbuf "n", we're done.
+ *
+ * It should be noted, that we should only do this either
+ * when offset is 0, i.e. data is pointing to the start
+ * or when the caller specifies an out argument to get
+ * the offset value in the mbuf to work with data pointer
+ * correctly.
+ *
+ * If offset is not 0 and caller did not provide out-argument
+ * to get offset, we should split the mbuf even when the length
+ * is contained in current mbuf.
*/
if ((off == 0 || offp) && len <= n->m_len - off)
goto ok;
-#if defined(PULLDOWN_STAT) && defined(INET6)
+#if defined(PULLDOWN_STAT) && INET6
ip6stat.ip6s_pulldown_copy++;
#endif
/*
- * when len < n->m_len - off and off != 0, it is a special case.
+ * when len <= n->m_len - off and off != 0, it is a special case.
* len bytes from <n, off> sits in single mbuf, but the caller does
* not like the starting position (off).
* chop the current mbuf into two pieces, set off to 0.
*/
- if (len < n->m_len - off) {
+ if (len <= n->m_len - off) {
o = m_copym(n, off, n->m_len - off, M_DONTWAIT);
if (o == NULL) {
m_freem(m);
* we need to take hlen from <n, off> and tlen from <n->m_next, 0>,
* and construct contiguous mbuf with m_len == len.
* note that hlen + tlen == len, and tlen > 0.
+ *
+ * Read these variables as head length and tail length
*/
hlen = n->m_len - off;
tlen = len - hlen;
if ((n->m_flags & M_EXT) == 0)
sharedcluster = 0;
else {
- if (n->m_ext.ext_free)
+ if (m_get_ext_free(n) != NULL)
sharedcluster = 1;
else if (m_mclhasreference(n))
sharedcluster = 1;
else
sharedcluster = 0;
}
+
+ /*
+ * If we have enough space left in current mbuf to accomodate
+ * tail length, copy tail length worth of data starting with next mbuf
+ * and adjust the length of next one accordingly.
+ */
if ((off == 0 || offp) && M_TRAILINGSPACE(n) >= tlen
&& !sharedcluster) {
m_copydata(n->m_next, 0, tlen, mtod(n, caddr_t) + n->m_len);
m_adj(n->m_next, tlen);
goto ok;
}
- if ((off == 0 || offp) && M_LEADINGSPACE(n->m_next) >= hlen
- && !sharedcluster) {
+
+ /*
+ * If have enough leading space in next mbuf to accomodate head length
+ * of current mbuf, and total resulting length of next mbuf is greater
+ * than or equal to requested len bytes, then just copy hlen from
+ * current to the next one and adjust sizes accordingly.
+ */
+ if ((off == 0 || offp) && M_LEADINGSPACE(n->m_next) >= hlen &&
+ (n->m_next->m_len + hlen) >= len && !sharedcluster) {
n->m_next->m_data -= hlen;
n->m_next->m_len += hlen;
bcopy(mtod(n, caddr_t) + off, mtod(n->m_next, caddr_t), hlen);
* now, we need to do the hard way. don't m_copy as there's no room
* on both end.
*/
-#if defined(PULLDOWN_STAT) && defined(INET6)
+#if defined(PULLDOWN_STAT) && INET6
ip6stat.ip6s_pulldown_alloc++;
#endif
MGET(o, M_DONTWAIT, m->m_type);
}
/*
- * pkthdr.aux chain manipulation.
- * we don't allow clusters at this moment.
+ * Create and return an m_tag, either by re-using space in a previous tag
+ * or by allocating a new mbuf/cluster
*/
-struct mbuf *
-m_aux_add(m, af, type)
- struct mbuf *m;
- int af, type;
+struct m_tag *
+m_tag_create(u_int32_t id, u_int16_t type, int len, int wait, struct mbuf *buf)
{
- struct mbuf *n;
- struct mauxtag *t;
-
- if ((m->m_flags & M_PKTHDR) == 0)
- return NULL;
-
- n = m_aux_find(m, af, type);
- if (n)
- return n;
-
- MGET(n, M_DONTWAIT, m->m_type);
- if (n == NULL)
- return NULL;
-
- t = mtod(n, struct mauxtag *);
- t->af = af;
- t->type = type;
- n->m_data += sizeof(struct mauxtag);
- n->m_len = 0;
- n->m_next = m->m_pkthdr.aux;
- m->m_pkthdr.aux = n;
- return n;
-}
+ struct m_tag *t = NULL;
+ struct m_tag *p;
-struct mbuf *
-m_aux_find(m, af, type)
- struct mbuf *m;
- int af, type;
-{
- struct mbuf *n;
- struct mauxtag *t;
+ if (len < 0)
+ return (NULL);
- if ((m->m_flags & M_PKTHDR) == 0)
- return NULL;
+ if (len + sizeof (struct m_tag) + sizeof (struct m_taghdr) > MLEN)
+ return (m_tag_alloc(id, type, len, wait));
- for (n = m->m_pkthdr.aux; n; n = n->m_next) {
- t = (struct mauxtag *)n->m_dat;
- if (t->af == af && t->type == type)
- return n;
- }
- return NULL;
-}
+ /*
+ * We've exhausted all external cases. Now, go through the m_tag
+ * chain and see if we can fit it in any of them.
+ * If not (t == NULL), call m_tag_alloc to store it in a new mbuf.
+ */
+ p = SLIST_FIRST(&buf->m_pkthdr.tags);
+ while(p != NULL) {
+ /* 2KCL m_tag */
+ if (M_TAG_ALIGN(p->m_tag_len) +
+ sizeof (struct m_taghdr) > MLEN) {
+ p = SLIST_NEXT(p, m_tag_link);
+ continue;
+ }
-void
-m_aux_delete(m, victim)
- struct mbuf *m;
- struct mbuf *victim;
-{
- struct mbuf *n, *prev, *next;
- struct mauxtag *t;
+ VERIFY(p->m_tag_cookie == M_TAG_VALID_PATTERN);
- if ((m->m_flags & M_PKTHDR) == 0)
- return;
+ struct mbuf *m = m_dtom(p);
+ struct m_taghdr *hdr = (struct m_taghdr *)(void *)m->m_data;
- prev = NULL;
- n = m->m_pkthdr.aux;
- while (n) {
- t = (struct mauxtag *)n->m_dat;
- next = n->m_next;
- if (n == victim) {
- if (prev)
- prev->m_next = n->m_next;
- else
- m->m_pkthdr.aux = n->m_next;
- n->m_next = NULL;
- m_free(n);
- } else
- prev = n;
- n = next;
+ VERIFY(IS_P2ALIGNED(hdr + 1, sizeof (u_int64_t)));
+ VERIFY(m->m_flags & M_TAGHDR && !(m->m_flags & M_EXT));
+
+ /* The mbuf can store this m_tag */
+ if (M_TAG_ALIGN(len) <= MLEN - m->m_len) {
+ t = (struct m_tag *)(void *)(m->m_data + m->m_len);
+ VERIFY(IS_P2ALIGNED(t, sizeof (u_int64_t)));
+ hdr->refcnt++;
+ m->m_len += M_TAG_ALIGN(len);
+ VERIFY(m->m_len <= MLEN);
+ break;
+ }
+
+ p = SLIST_NEXT(p, m_tag_link);
}
+
+ if (t == NULL)
+ return (m_tag_alloc(id, type, len, wait));
+
+ t->m_tag_cookie = M_TAG_VALID_PATTERN;
+ t->m_tag_type = type;
+ t->m_tag_len = len;
+ t->m_tag_id = id;
+ if (len > 0)
+ bzero(t + 1, len);
+ return (t);
}
/* Get a packet tag structure along with specified data following. */
struct m_tag *t;
if (len < 0)
- return NULL;
-#ifndef __APPLE__
- t = malloc(len + sizeof(struct m_tag), M_PACKET_TAGS, wait);
-#else
- /*MALLOC(t, struct m_tag *, len + sizeof(struct m_tag), M_TEMP, M_WAITOK);*/
- if (len + sizeof(struct m_tag) <= MLEN) {
+ return (NULL);
+
+ if (M_TAG_ALIGN(len) + sizeof (struct m_taghdr) <= MLEN) {
struct mbuf *m = m_get(wait, MT_TAG);
+ struct m_taghdr *hdr;
+
if (m == NULL)
- return NULL;
- t = (struct m_tag *) m->m_dat;
- } else if (len + sizeof(struct m_tag) <= MCLBYTES) {
- MCLALLOC((caddr_t)t, wait);
- } else
+ return (NULL);
+
+ m->m_flags |= M_TAGHDR;
+
+ hdr = (struct m_taghdr *)(void *)m->m_data;
+ VERIFY(IS_P2ALIGNED(hdr + 1, sizeof (u_int64_t)));
+ hdr->refcnt = 1;
+ m->m_len += sizeof (struct m_taghdr);
+ t = (struct m_tag *)(void *)(m->m_data + m->m_len);
+ VERIFY(IS_P2ALIGNED(t, sizeof (u_int64_t)));
+ m->m_len += M_TAG_ALIGN(len);
+ VERIFY(m->m_len <= MLEN);
+ } else if (len + sizeof (struct m_tag) <= MCLBYTES) {
+ t = (struct m_tag *)(void *)m_mclalloc(wait);
+ } else {
t = NULL;
-#endif
+ }
+
if (t == NULL)
- return NULL;
+ return (NULL);
+
+ VERIFY(IS_P2ALIGNED(t, sizeof (u_int64_t)));
+ t->m_tag_cookie = M_TAG_VALID_PATTERN;
t->m_tag_type = type;
t->m_tag_len = len;
t->m_tag_id = id;
- return t;
+ if (len > 0)
+ bzero(t + 1, len);
+ return (t);
}
void
m_tag_free(struct m_tag *t)
{
-#ifndef __APPLE__
- free(t, M_PACKET_TAGS);
-#else
- /* FREE(t, M_TEMP); */
+#if CONFIG_MACF_NET
+ if (t != NULL &&
+ t->m_tag_id == KERNEL_MODULE_TAG_ID &&
+ t->m_tag_type == KERNEL_TAG_TYPE_MACLABEL)
+ mac_mbuf_tag_destroy(t);
+#endif
if (t == NULL)
return;
- if (t->m_tag_len <= MLEN) {
+
+ VERIFY(t->m_tag_cookie == M_TAG_VALID_PATTERN);
+
+ if (M_TAG_ALIGN(t->m_tag_len) + sizeof (struct m_taghdr) <= MLEN) {
struct mbuf * m = m_dtom(t);
- m_free(m);
+ VERIFY(m->m_flags & M_TAGHDR);
+ struct m_taghdr *hdr = (struct m_taghdr *)(void *)m->m_data;
+
+ VERIFY(IS_P2ALIGNED(hdr + 1, sizeof (u_int64_t)));
+
+ /* No other tags in this mbuf */
+ if(--hdr->refcnt == 0) {
+ m_free(m);
+ return;
+ }
+
+ /* Pattern-fill the header */
+ u_int64_t *fill_ptr = (u_int64_t *)t;
+ u_int64_t *end_ptr = (u_int64_t *)(t + 1);
+ while (fill_ptr < end_ptr) {
+ *fill_ptr = M_TAG_FREE_PATTERN;
+ fill_ptr++;
+ }
} else {
- MCLFREE((caddr_t)t);
+ m_mclfree((caddr_t)t);
}
-#endif
}
/* Prepend a packet tag. */
void
m_tag_prepend(struct mbuf *m, struct m_tag *t)
{
- KASSERT(m && t, ("m_tag_prepend: null argument, m %p t %p", m, t));
+ VERIFY(m != NULL && t != NULL);
+
SLIST_INSERT_HEAD(&m->m_pkthdr.tags, t, m_tag_link);
}
void
m_tag_unlink(struct mbuf *m, struct m_tag *t)
{
- KASSERT(m && t, ("m_tag_unlink: null argument, m %p t %p", m, t));
+ VERIFY(m->m_flags & M_PKTHDR);
+ VERIFY(t != NULL && t->m_tag_cookie == M_TAG_VALID_PATTERN);
+
SLIST_REMOVE(&m->m_pkthdr.tags, t, m_tag, m_tag_link);
}
void
m_tag_delete(struct mbuf *m, struct m_tag *t)
{
- KASSERT(m && t, ("m_tag_delete: null argument, m %p t %p", m, t));
m_tag_unlink(m, t);
m_tag_free(t);
}
{
struct m_tag *p, *q;
- KASSERT(m, ("m_tag_delete_chain: null mbuf"));
- if (t != NULL)
+ VERIFY(m->m_flags & M_PKTHDR);
+
+ if (t != NULL) {
p = t;
- else
+ } else {
p = SLIST_FIRST(&m->m_pkthdr.tags);
+ }
if (p == NULL)
return;
- while ((q = SLIST_NEXT(p, m_tag_link)) != NULL)
+
+ VERIFY(p->m_tag_cookie == M_TAG_VALID_PATTERN);
+ while ((q = SLIST_NEXT(p, m_tag_link)) != NULL) {
+ VERIFY(q->m_tag_cookie == M_TAG_VALID_PATTERN);
m_tag_delete(m, q);
+ }
m_tag_delete(m, p);
}
{
struct m_tag *p;
- KASSERT(m, ("m_tag_find: null mbuf"));
- if (t == NULL)
+ VERIFY(m->m_flags & M_PKTHDR);
+
+ if (t == NULL) {
p = SLIST_FIRST(&m->m_pkthdr.tags);
- else
+ } else {
+ VERIFY(t->m_tag_cookie == M_TAG_VALID_PATTERN);
p = SLIST_NEXT(t, m_tag_link);
+ }
while (p != NULL) {
+ VERIFY(p->m_tag_cookie == M_TAG_VALID_PATTERN);
if (p->m_tag_id == id && p->m_tag_type == type)
- return p;
+ return (p);
p = SLIST_NEXT(p, m_tag_link);
}
- return NULL;
+ return (NULL);
}
/* Copy a single tag. */
{
struct m_tag *p;
- KASSERT(t, ("m_tag_copy: null tag"));
+ VERIFY(t != NULL);
+
p = m_tag_alloc(t->m_tag_id, t->m_tag_type, t->m_tag_len, how);
if (p == NULL)
return (NULL);
+#if CONFIG_MACF_NET
+ /*
+ * XXXMAC: we should probably pass off the initialization, and
+ * copying here? can we hid that KERNEL_TAG_TYPE_MACLABEL is
+ * special from the mbuf code?
+ */
+ if (t != NULL &&
+ t->m_tag_id == KERNEL_MODULE_TAG_ID &&
+ t->m_tag_type == KERNEL_TAG_TYPE_MACLABEL) {
+ if (mac_mbuf_tag_init(p, how) != 0) {
+ m_tag_free(p);
+ return (NULL);
+ }
+ mac_mbuf_tag_copy(t, p);
+ } else
+#endif
bcopy(t + 1, p + 1, t->m_tag_len); /* Copy the data */
- return p;
+ return (p);
}
/*
{
struct m_tag *p, *t, *tprev = NULL;
- KASSERT(to && from,
- ("m_tag_copy: null argument, to %p from %p", to, from));
+ VERIFY((to->m_flags & M_PKTHDR) && (from->m_flags & M_PKTHDR));
+
m_tag_delete_chain(to, NULL);
SLIST_FOREACH(p, &from->m_pkthdr.tags, m_tag_link) {
+ VERIFY(p->m_tag_cookie == M_TAG_VALID_PATTERN);
t = m_tag_copy(p, how);
if (t == NULL) {
m_tag_delete_chain(to, NULL);
- return 0;
+ return (0);
}
- if (tprev == NULL)
+ if (tprev == NULL) {
SLIST_INSERT_HEAD(&to->m_pkthdr.tags, t, m_tag_link);
- else {
+ } else {
SLIST_INSERT_AFTER(tprev, t, m_tag_link);
tprev = t;
}
}
- return 1;
+ return (1);
}
-/* Initialize tags on an mbuf. */
+/* Initialize dynamic and static tags on an mbuf. */
void
-m_tag_init(struct mbuf *m)
+m_tag_init(struct mbuf *m, int all)
{
+ VERIFY(m->m_flags & M_PKTHDR);
+
SLIST_INIT(&m->m_pkthdr.tags);
+ /*
+ * If the caller wants to preserve static mbuf tags
+ * (e.g. m_dup_pkthdr), don't zero them out.
+ */
+ if (all) {
+ bzero(&m->m_pkthdr.builtin_mtag._net_mtag,
+ sizeof (m->m_pkthdr.builtin_mtag._net_mtag));
+ }
}
/* Get first tag in chain. */
struct m_tag *
m_tag_first(struct mbuf *m)
{
- return SLIST_FIRST(&m->m_pkthdr.tags);
+ VERIFY(m->m_flags & M_PKTHDR);
+
+ return (SLIST_FIRST(&m->m_pkthdr.tags));
}
/* Get next tag in chain. */
struct m_tag *
-m_tag_next(__unused struct mbuf *m, struct m_tag *t)
+m_tag_next(struct mbuf *m, struct m_tag *t)
{
- return SLIST_NEXT(t, m_tag_link);
+#pragma unused(m)
+ VERIFY(t != NULL);
+ VERIFY(t->m_tag_cookie == M_TAG_VALID_PATTERN);
+
+ return (SLIST_NEXT(t, m_tag_link));
+}
+
+int
+m_set_traffic_class(struct mbuf *m, mbuf_traffic_class_t tc)
+{
+ u_int32_t val = MBUF_TC2SCVAL(tc); /* just the val portion */
+
+ return (m_set_service_class(m, m_service_class_from_val(val)));
+}
+
+mbuf_traffic_class_t
+m_get_traffic_class(struct mbuf *m)
+{
+ return (MBUF_SC2TC(m_get_service_class(m)));
+}
+
+int
+m_set_service_class(struct mbuf *m, mbuf_svc_class_t sc)
+{
+ int error = 0;
+
+ VERIFY(m->m_flags & M_PKTHDR);
+
+ if (MBUF_VALID_SC(sc))
+ m->m_pkthdr.pkt_svc = sc;
+ else
+ error = EINVAL;
+
+ return (error);
+}
+
+mbuf_svc_class_t
+m_get_service_class(struct mbuf *m)
+{
+ mbuf_svc_class_t sc;
+
+ VERIFY(m->m_flags & M_PKTHDR);
+
+ if (MBUF_VALID_SC(m->m_pkthdr.pkt_svc))
+ sc = m->m_pkthdr.pkt_svc;
+ else
+ sc = MBUF_SC_BE;
+
+ return (sc);
+}
+
+mbuf_svc_class_t
+m_service_class_from_idx(u_int32_t i)
+{
+ mbuf_svc_class_t sc = MBUF_SC_BE;
+
+ switch (i) {
+ case SCIDX_BK_SYS:
+ return (MBUF_SC_BK_SYS);
+
+ case SCIDX_BK:
+ return (MBUF_SC_BK);
+
+ case SCIDX_BE:
+ return (MBUF_SC_BE);
+
+ case SCIDX_RD:
+ return (MBUF_SC_RD);
+
+ case SCIDX_OAM:
+ return (MBUF_SC_OAM);
+
+ case SCIDX_AV:
+ return (MBUF_SC_AV);
+
+ case SCIDX_RV:
+ return (MBUF_SC_RV);
+
+ case SCIDX_VI:
+ return (MBUF_SC_VI);
+
+ case SCIDX_VO:
+ return (MBUF_SC_VO);
+
+ case SCIDX_CTL:
+ return (MBUF_SC_CTL);
+
+ default:
+ break;
+ }
+
+ VERIFY(0);
+ /* NOTREACHED */
+ return (sc);
+}
+
+mbuf_svc_class_t
+m_service_class_from_val(u_int32_t v)
+{
+ mbuf_svc_class_t sc = MBUF_SC_BE;
+
+ switch (v) {
+ case SCVAL_BK_SYS:
+ return (MBUF_SC_BK_SYS);
+
+ case SCVAL_BK:
+ return (MBUF_SC_BK);
+
+ case SCVAL_BE:
+ return (MBUF_SC_BE);
+
+ case SCVAL_RD:
+ return (MBUF_SC_RD);
+
+ case SCVAL_OAM:
+ return (MBUF_SC_OAM);
+
+ case SCVAL_AV:
+ return (MBUF_SC_AV);
+
+ case SCVAL_RV:
+ return (MBUF_SC_RV);
+
+ case SCVAL_VI:
+ return (MBUF_SC_VI);
+
+ case SCVAL_VO:
+ return (MBUF_SC_VO);
+
+ case SCVAL_CTL:
+ return (MBUF_SC_CTL);
+
+ default:
+ break;
+ }
+
+ VERIFY(0);
+ /* NOTREACHED */
+ return (sc);
+}
+
+uint16_t
+m_adj_sum16(struct mbuf *m, uint32_t start, uint32_t dataoff,
+ uint32_t datalen, uint32_t sum)
+{
+ uint32_t total_sub = 0; /* total to subtract */
+ uint32_t mlen = m_pktlen(m); /* frame length */
+ uint32_t bytes = (dataoff + datalen); /* bytes covered by sum */
+ int len;
+
+ ASSERT(bytes <= mlen);
+
+ /*
+ * Take care of excluding (len > 0) or including (len < 0)
+ * extraneous octets at the beginning of the packet, taking
+ * into account the start offset.
+ */
+ len = (dataoff - start);
+ if (len > 0)
+ total_sub = m_sum16(m, start, len);
+ else if (len < 0)
+ sum += m_sum16(m, dataoff, -len);
+
+ /*
+ * Take care of excluding any postpended extraneous octets.
+ */
+ len = (mlen - bytes);
+ if (len > 0) {
+ struct mbuf *m0 = m;
+ uint32_t extra = m_sum16(m, bytes, len);
+ uint32_t off = bytes, off0 = off;
+
+ while (off > 0) {
+ if (__improbable(m == NULL)) {
+ panic("%s: invalid mbuf chain %p [off %u, "
+ "len %u]", __func__, m0, off0, len);
+ /* NOTREACHED */
+ }
+ if (off < m->m_len)
+ break;
+ off -= m->m_len;
+ m = m->m_next;
+ }
+
+ /* if we started on odd-alignment, swap the value */
+ if ((uintptr_t)(mtod(m, uint8_t *) + off) & 1)
+ total_sub += ((extra << 8) & 0xffff) | (extra >> 8);
+ else
+ total_sub += extra;
+
+ total_sub = (total_sub >> 16) + (total_sub & 0xffff);
+ }
+
+ /*
+ * 1's complement subtract any extraneous octets.
+ */
+ if (total_sub != 0) {
+ if (total_sub >= sum)
+ sum = ~(total_sub - sum) & 0xffff;
+ else
+ sum -= total_sub;
+ }
+
+ /* fold 32-bit to 16-bit */
+ sum = (sum >> 16) + (sum & 0xffff); /* 17-bit */
+ sum = (sum >> 16) + (sum & 0xffff); /* 16-bit + carry */
+ sum = (sum >> 16) + (sum & 0xffff); /* final carry */
+
+ return (sum & 0xffff);
+}
+
+uint16_t
+m_sum16(struct mbuf *m, uint32_t off, uint32_t len)
+{
+ int mlen;
+
+ /*
+ * Sanity check
+ *
+ * Use m_length2() instead of m_length(), as we cannot rely on
+ * the caller setting m_pkthdr.len correctly, if the mbuf is
+ * a M_PKTHDR one.
+ */
+ if ((mlen = m_length2(m, NULL)) < (off + len)) {
+ panic("%s: mbuf %p len (%d) < off+len (%d+%d)\n", __func__,
+ m, mlen, off, len);
+ /* NOTREACHED */
+ }
+
+ return (os_cpu_in_cksum_mbuf(m, len, off, 0));
}
projects / apple / xnu.git / blobdiff