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-rwxr-xr-xnetwerk/sctp/src/user_mbuf.c1431
1 files changed, 1431 insertions, 0 deletions
diff --git a/netwerk/sctp/src/user_mbuf.c b/netwerk/sctp/src/user_mbuf.c
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index 000000000..de8f0fbc8
--- /dev/null
+++ b/netwerk/sctp/src/user_mbuf.c
@@ -0,0 +1,1431 @@
+/*-
+ * Copyright (c) 1982, 1986, 1988, 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.
+ * 3. 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.
+ *
+ */
+
+/*
+ * __Userspace__ version of /usr/src/sys/kern/kern_mbuf.c
+ * We are initializing two zones for Mbufs and Clusters.
+ *
+ */
+
+#include <stdio.h>
+#include <string.h>
+/* #include <sys/param.h> This defines MSIZE 256 */
+#if !defined(SCTP_SIMPLE_ALLOCATOR)
+#include "umem.h"
+#endif
+#include "user_mbuf.h"
+#include "user_environment.h"
+#include "user_atomic.h"
+#include "netinet/sctp_pcb.h"
+
+struct mbstat mbstat;
+#define KIPC_MAX_LINKHDR 4 /* int: max length of link header (see sys/sysclt.h) */
+#define KIPC_MAX_PROTOHDR 5 /* int: max length of network header (see sys/sysclt.h)*/
+int max_linkhdr = KIPC_MAX_LINKHDR;
+int max_protohdr = KIPC_MAX_PROTOHDR; /* Size of largest protocol layer header. */
+
+/*
+ * Zones from which we allocate.
+ */
+sctp_zone_t zone_mbuf;
+sctp_zone_t zone_clust;
+sctp_zone_t zone_ext_refcnt;
+
+/* __Userspace__ clust_mb_args will be passed as callback data to mb_ctor_clust
+ * and mb_dtor_clust.
+ * Note: I had to use struct clust_args as an encapsulation for an mbuf pointer.
+ * struct mbuf * clust_mb_args; does not work.
+ */
+struct clust_args clust_mb_args;
+
+
+/* __Userspace__
+ * Local prototypes.
+ */
+static int mb_ctor_mbuf(void *, void *, int);
+static int mb_ctor_clust(void *, void *, int);
+static void mb_dtor_mbuf(void *, void *);
+static void mb_dtor_clust(void *, void *);
+
+
+/***************** Functions taken from user_mbuf.h *************/
+
+static int mbuf_constructor_dup(struct mbuf *m, int pkthdr, short type)
+{
+ int flags = pkthdr;
+ if (type == MT_NOINIT)
+ return (0);
+
+ m->m_next = NULL;
+ m->m_nextpkt = NULL;
+ m->m_len = 0;
+ m->m_flags = flags;
+ m->m_type = type;
+ if (flags & M_PKTHDR) {
+ m->m_data = m->m_pktdat;
+ m->m_pkthdr.rcvif = NULL;
+ m->m_pkthdr.len = 0;
+ m->m_pkthdr.header = NULL;
+ m->m_pkthdr.csum_flags = 0;
+ m->m_pkthdr.csum_data = 0;
+ m->m_pkthdr.tso_segsz = 0;
+ m->m_pkthdr.ether_vtag = 0;
+ SLIST_INIT(&m->m_pkthdr.tags);
+ } else
+ m->m_data = m->m_dat;
+
+ return (0);
+}
+
+/* __Userspace__ */
+struct mbuf *
+m_get(int how, short type)
+{
+ struct mbuf *mret;
+#if defined(SCTP_SIMPLE_ALLOCATOR)
+ struct mb_args mbuf_mb_args;
+
+ /* The following setter function is not yet being enclosed within
+ * #if USING_MBUF_CONSTRUCTOR - #endif, until I have thoroughly tested
+ * mb_dtor_mbuf. See comment there
+ */
+ mbuf_mb_args.flags = 0;
+ mbuf_mb_args.type = type;
+#endif
+ /* Mbuf master zone, zone_mbuf, has already been
+ * created in mbuf_init() */
+ mret = SCTP_ZONE_GET(zone_mbuf, struct mbuf);
+#if defined(SCTP_SIMPLE_ALLOCATOR)
+ mb_ctor_mbuf(mret, &mbuf_mb_args, 0);
+#endif
+ /*mret = ((struct mbuf *)umem_cache_alloc(zone_mbuf, UMEM_DEFAULT));*/
+
+ /* There are cases when an object available in the current CPU's
+ * loaded magazine and in those cases the object's constructor is not applied.
+ * If that is the case, then we are duplicating constructor initialization here,
+ * so that the mbuf is properly constructed before returning it.
+ */
+ if (mret) {
+#if USING_MBUF_CONSTRUCTOR
+ if (! (mret->m_type == type) ) {
+ mbuf_constructor_dup(mret, 0, type);
+ }
+#else
+ mbuf_constructor_dup(mret, 0, type);
+#endif
+
+ }
+ return mret;
+}
+
+
+/* __Userspace__ */
+struct mbuf *
+m_gethdr(int how, short type)
+{
+ struct mbuf *mret;
+#if defined(SCTP_SIMPLE_ALLOCATOR)
+ struct mb_args mbuf_mb_args;
+
+ /* The following setter function is not yet being enclosed within
+ * #if USING_MBUF_CONSTRUCTOR - #endif, until I have thoroughly tested
+ * mb_dtor_mbuf. See comment there
+ */
+ mbuf_mb_args.flags = M_PKTHDR;
+ mbuf_mb_args.type = type;
+#endif
+ mret = SCTP_ZONE_GET(zone_mbuf, struct mbuf);
+#if defined(SCTP_SIMPLE_ALLOCATOR)
+ mb_ctor_mbuf(mret, &mbuf_mb_args, 0);
+#endif
+ /*mret = ((struct mbuf *)umem_cache_alloc(zone_mbuf, UMEM_DEFAULT));*/
+ /* There are cases when an object available in the current CPU's
+ * loaded magazine and in those cases the object's constructor is not applied.
+ * If that is the case, then we are duplicating constructor initialization here,
+ * so that the mbuf is properly constructed before returning it.
+ */
+ if (mret) {
+#if USING_MBUF_CONSTRUCTOR
+ if (! ((mret->m_flags & M_PKTHDR) && (mret->m_type == type)) ) {
+ mbuf_constructor_dup(mret, M_PKTHDR, type);
+ }
+#else
+ mbuf_constructor_dup(mret, M_PKTHDR, type);
+#endif
+ }
+ return mret;
+}
+
+/* __Userspace__ */
+struct mbuf *
+m_free(struct mbuf *m)
+{
+
+ struct mbuf *n = m->m_next;
+
+ if (m->m_flags & M_EXT)
+ mb_free_ext(m);
+ else if ((m->m_flags & M_NOFREE) == 0) {
+#if defined(SCTP_SIMPLE_ALLOCATOR)
+ mb_dtor_mbuf(m, NULL);
+#endif
+ SCTP_ZONE_FREE(zone_mbuf, m);
+ }
+ /*umem_cache_free(zone_mbuf, m);*/
+ return (n);
+}
+
+
+static int clust_constructor_dup(caddr_t m_clust, struct mbuf* m)
+{
+ u_int *refcnt;
+ int type, size;
+
+ /* Assigning cluster of MCLBYTES. TODO: Add jumbo frame functionality */
+ type = EXT_CLUSTER;
+ size = MCLBYTES;
+
+ refcnt = SCTP_ZONE_GET(zone_ext_refcnt, u_int);
+ /*refcnt = (u_int *)umem_cache_alloc(zone_ext_refcnt, UMEM_DEFAULT);*/
+ if (refcnt == NULL) {
+#if !defined(SCTP_SIMPLE_ALLOCATOR)
+ umem_reap();
+#endif
+ refcnt = SCTP_ZONE_GET(zone_ext_refcnt, u_int);
+ /*refcnt = (u_int *)umem_cache_alloc(zone_ext_refcnt, UMEM_DEFAULT);*/
+ }
+ *refcnt = 1;
+ if (m != NULL) {
+ m->m_ext.ext_buf = (caddr_t)m_clust;
+ m->m_data = m->m_ext.ext_buf;
+ m->m_flags |= M_EXT;
+ m->m_ext.ext_free = NULL;
+ m->m_ext.ext_args = NULL;
+ m->m_ext.ext_size = size;
+ m->m_ext.ext_type = type;
+ m->m_ext.ref_cnt = refcnt;
+ }
+
+ return (0);
+}
+
+
+
+/* __Userspace__ */
+void
+m_clget(struct mbuf *m, int how)
+{
+ caddr_t mclust_ret;
+#if defined(SCTP_SIMPLE_ALLOCATOR)
+ struct clust_args clust_mb_args;
+#endif
+ if (m->m_flags & M_EXT) {
+ SCTPDBG(SCTP_DEBUG_USR, "%s: %p mbuf already has cluster\n", __func__, (void *)m);
+ }
+ m->m_ext.ext_buf = (char *)NULL;
+#if defined(SCTP_SIMPLE_ALLOCATOR)
+ clust_mb_args.parent_mbuf = m;
+#endif
+ mclust_ret = SCTP_ZONE_GET(zone_clust, char);
+#if defined(SCTP_SIMPLE_ALLOCATOR)
+ mb_ctor_clust(mclust_ret, &clust_mb_args, 0);
+#endif
+ /*mclust_ret = umem_cache_alloc(zone_clust, UMEM_DEFAULT);*/
+ /*
+ On a cluster allocation failure, call umem_reap() and retry.
+ */
+
+ if (mclust_ret == NULL) {
+#if !defined(SCTP_SIMPLE_ALLOCATOR)
+ /* mclust_ret = SCTP_ZONE_GET(zone_clust, char);
+ mb_ctor_clust(mclust_ret, &clust_mb_args, 0);
+#else*/
+ umem_reap();
+ mclust_ret = SCTP_ZONE_GET(zone_clust, char);
+#endif
+ /*mclust_ret = umem_cache_alloc(zone_clust, UMEM_DEFAULT);*/
+ if (NULL == mclust_ret) {
+ SCTPDBG(SCTP_DEBUG_USR, "Memory allocation failure in %s\n", __func__);
+ }
+ }
+
+#if USING_MBUF_CONSTRUCTOR
+ if ((m->m_ext.ext_buf == NULL)) {
+ clust_constructor_dup(mclust_ret, m);
+ }
+#else
+ clust_constructor_dup(mclust_ret, m);
+#endif
+}
+
+/*
+ * Unlink a tag from the list of tags associated with an mbuf.
+ */
+static __inline void
+m_tag_unlink(struct mbuf *m, struct m_tag *t)
+{
+
+ SLIST_REMOVE(&m->m_pkthdr.tags, t, m_tag, m_tag_link);
+}
+
+/*
+ * Reclaim resources associated with a tag.
+ */
+static __inline void
+m_tag_free(struct m_tag *t)
+{
+
+ (*t->m_tag_free)(t);
+}
+
+/*
+ * Set up the contents of a tag. Note that this does not fill in the free
+ * method; the caller is expected to do that.
+ *
+ * XXX probably should be called m_tag_init, but that was already taken.
+ */
+static __inline void
+m_tag_setup(struct m_tag *t, u_int32_t cookie, int type, int len)
+{
+
+ t->m_tag_id = type;
+ t->m_tag_len = len;
+ t->m_tag_cookie = cookie;
+}
+
+/************ End functions from user_mbuf.h ******************/
+
+
+
+/************ End functions to substitute umem_cache_alloc and umem_cache_free **************/
+
+/* __Userspace__
+ * TODO: mbuf_init must be called in the initialization routines
+ * of userspace stack.
+ */
+void
+mbuf_init(void *dummy)
+{
+
+ /*
+ * __Userspace__Configure UMA zones for Mbufs and Clusters.
+ * (TODO: m_getcl() - using packet secondary zone).
+ * There is no provision for trash_init and trash_fini in umem.
+ *
+ */
+ /* zone_mbuf = umem_cache_create(MBUF_MEM_NAME, MSIZE, 0,
+ mb_ctor_mbuf, mb_dtor_mbuf, NULL,
+ &mbuf_mb_args,
+ NULL, 0);
+ zone_mbuf = umem_cache_create(MBUF_MEM_NAME, MSIZE, 0, NULL, NULL, NULL, NULL, NULL, 0);*/
+#if defined(SCTP_SIMPLE_ALLOCATOR)
+ SCTP_ZONE_INIT(zone_mbuf, MBUF_MEM_NAME, MSIZE, 0);
+#else
+ zone_mbuf = umem_cache_create(MBUF_MEM_NAME, MSIZE, 0,
+ mb_ctor_mbuf, mb_dtor_mbuf, NULL,
+ NUULL,
+ NULL, 0);
+#endif
+ /*zone_ext_refcnt = umem_cache_create(MBUF_EXTREFCNT_MEM_NAME, sizeof(u_int), 0,
+ NULL, NULL, NULL,
+ NULL,
+ NULL, 0);*/
+ SCTP_ZONE_INIT(zone_ext_refcnt, MBUF_EXTREFCNT_MEM_NAME, sizeof(u_int), 0);
+
+ /*zone_clust = umem_cache_create(MBUF_CLUSTER_MEM_NAME, MCLBYTES, 0,
+ mb_ctor_clust, mb_dtor_clust, NULL,
+ &clust_mb_args,
+ NULL, 0);
+ zone_clust = umem_cache_create(MBUF_CLUSTER_MEM_NAME, MCLBYTES, 0, NULL, NULL, NULL, NULL, NULL,0);*/
+#if defined(SCTP_SIMPLE_ALLOCATOR)
+ SCTP_ZONE_INIT(zone_clust, MBUF_CLUSTER_MEM_NAME, MCLBYTES, 0);
+#else
+ zone_clust = umem_cache_create(MBUF_CLUSTER_MEM_NAME, MCLBYTES, 0,
+ mb_ctor_clust, mb_dtor_clust, NULL,
+ &clust_mb_args,
+ NULL, 0);
+#endif
+
+ /* uma_prealloc() goes here... */
+
+ /* __Userspace__ Add umem_reap here for low memory situation?
+ *
+ */
+
+
+ /*
+ * [Re]set counters and local statistics knobs.
+ *
+ */
+
+ mbstat.m_mbufs = 0;
+ mbstat.m_mclusts = 0;
+ mbstat.m_drain = 0;
+ mbstat.m_msize = MSIZE;
+ mbstat.m_mclbytes = MCLBYTES;
+ mbstat.m_minclsize = MINCLSIZE;
+ mbstat.m_mlen = MLEN;
+ mbstat.m_mhlen = MHLEN;
+ mbstat.m_numtypes = MT_NTYPES;
+
+ mbstat.m_mcfail = mbstat.m_mpfail = 0;
+ mbstat.sf_iocnt = 0;
+ mbstat.sf_allocwait = mbstat.sf_allocfail = 0;
+
+}
+
+
+
+/*
+ * __Userspace__
+ *
+ * Constructor for Mbuf master zone. We have a different constructor
+ * for allocating the cluster.
+ *
+ * The 'arg' pointer points to a mb_args structure which
+ * contains call-specific information required to support the
+ * mbuf allocation API. See user_mbuf.h.
+ *
+ * The flgs parameter below can be UMEM_DEFAULT or UMEM_NOFAIL depending on what
+ * was passed when umem_cache_alloc was called.
+ * TODO: Use UMEM_NOFAIL in umem_cache_alloc and also define a failure handler
+ * and call umem_nofail_callback(my_failure_handler) in the stack initialization routines
+ * The advantage of using UMEM_NOFAIL is that we don't have to check if umem_cache_alloc
+ * was successful or not. The failure handler would take care of it, if we use the UMEM_NOFAIL
+ * flag.
+ *
+ * NOTE Ref: http://docs.sun.com/app/docs/doc/819-2243/6n4i099p2?l=en&a=view&q=umem_zalloc)
+ * The umem_nofail_callback() function sets the **process-wide** UMEM_NOFAIL callback.
+ * It also mentions that umem_nofail_callback is Evolving.
+ *
+ */
+static int
+mb_ctor_mbuf(void *mem, void *arg, int flgs)
+{
+#if USING_MBUF_CONSTRUCTOR
+ struct mbuf *m;
+ struct mb_args *args;
+
+ int flags;
+ short type;
+
+ m = (struct mbuf *)mem;
+ args = (struct mb_args *)arg;
+ flags = args->flags;
+ type = args->type;
+
+ /*
+ * The mbuf is initialized later.
+ *
+ */
+ if (type == MT_NOINIT)
+ return (0);
+
+ m->m_next = NULL;
+ m->m_nextpkt = NULL;
+ m->m_len = 0;
+ m->m_flags = flags;
+ m->m_type = type;
+ if (flags & M_PKTHDR) {
+ m->m_data = m->m_pktdat;
+ m->m_pkthdr.rcvif = NULL;
+ m->m_pkthdr.len = 0;
+ m->m_pkthdr.header = NULL;
+ m->m_pkthdr.csum_flags = 0;
+ m->m_pkthdr.csum_data = 0;
+ m->m_pkthdr.tso_segsz = 0;
+ m->m_pkthdr.ether_vtag = 0;
+ SLIST_INIT(&m->m_pkthdr.tags);
+ } else
+ m->m_data = m->m_dat;
+#endif
+ return (0);
+}
+
+
+/*
+ * __Userspace__
+ * The Mbuf master zone destructor.
+ * This would be called in response to umem_cache_destroy
+ * TODO: Recheck if this is what we want to do in this destructor.
+ * (Note: the number of times mb_dtor_mbuf is called is equal to the
+ * number of individual mbufs allocated from zone_mbuf.
+ */
+static void
+mb_dtor_mbuf(void *mem, void *arg)
+{
+ struct mbuf *m;
+
+ m = (struct mbuf *)mem;
+ if ((m->m_flags & M_PKTHDR) != 0) {
+ m_tag_delete_chain(m, NULL);
+ }
+}
+
+
+/* __Userspace__
+ * The Cluster zone constructor.
+ *
+ * Here the 'arg' pointer points to the Mbuf which we
+ * are configuring cluster storage for. If 'arg' is
+ * empty we allocate just the cluster without setting
+ * the mbuf to it. See mbuf.h.
+ */
+static int
+mb_ctor_clust(void *mem, void *arg, int flgs)
+{
+
+#if USING_MBUF_CONSTRUCTOR
+ struct mbuf *m;
+ struct clust_args * cla;
+ u_int *refcnt;
+ int type, size;
+ sctp_zone_t zone;
+
+ /* Assigning cluster of MCLBYTES. TODO: Add jumbo frame functionality */
+ type = EXT_CLUSTER;
+ zone = zone_clust;
+ size = MCLBYTES;
+
+ cla = (struct clust_args *)arg;
+ m = cla->parent_mbuf;
+
+ refcnt = SCTP_ZONE_GET(zone_ext_refcnt, u_int);
+ /*refcnt = (u_int *)umem_cache_alloc(zone_ext_refcnt, UMEM_DEFAULT);*/
+ *refcnt = 1;
+
+ if (m != NULL) {
+ m->m_ext.ext_buf = (caddr_t)mem;
+ m->m_data = m->m_ext.ext_buf;
+ m->m_flags |= M_EXT;
+ m->m_ext.ext_free = NULL;
+ m->m_ext.ext_args = NULL;
+ m->m_ext.ext_size = size;
+ m->m_ext.ext_type = type;
+ m->m_ext.ref_cnt = refcnt;
+ }
+#endif
+ return (0);
+}
+
+/* __Userspace__ */
+static void
+mb_dtor_clust(void *mem, void *arg)
+{
+
+ /* mem is of type caddr_t. In sys/types.h we have typedef char * caddr_t; */
+ /* mb_dtor_clust is called at time of umem_cache_destroy() (the number of times
+ * mb_dtor_clust is called is equal to the number of individual mbufs allocated
+ * from zone_clust. Similarly for mb_dtor_mbuf).
+ * At this point the following:
+ * struct mbuf *m;
+ * m = (struct mbuf *)arg;
+ * assert (*(m->m_ext.ref_cnt) == 0); is not meaningful since m->m_ext.ref_cnt = NULL;
+ * has been done in mb_free_ext().
+ */
+
+}
+
+
+
+
+/* Unlink and free a packet tag. */
+void
+m_tag_delete(struct mbuf *m, struct m_tag *t)
+{
+ KASSERT(m && t, ("m_tag_delete: null argument, m %p t %p", (void *)m, (void *)t));
+ m_tag_unlink(m, t);
+ m_tag_free(t);
+}
+
+
+/* Unlink and free a packet tag chain, starting from given tag. */
+void
+m_tag_delete_chain(struct mbuf *m, struct m_tag *t)
+{
+
+ struct m_tag *p, *q;
+
+ KASSERT(m, ("m_tag_delete_chain: null mbuf"));
+ if (t != NULL)
+ p = t;
+ else
+ p = SLIST_FIRST(&m->m_pkthdr.tags);
+ if (p == NULL)
+ return;
+ while ((q = SLIST_NEXT(p, m_tag_link)) != NULL)
+ m_tag_delete(m, q);
+ m_tag_delete(m, p);
+}
+
+#if 0
+static void
+sctp_print_mbuf_chain(struct mbuf *m)
+{
+ SCTP_DEBUG_USR(SCTP_DEBUG_USR, "Printing mbuf chain %p.\n", (void *)m);
+ for(; m; m=m->m_next) {
+ SCTP_DEBUG_USR(SCTP_DEBUG_USR, "%p: m_len = %ld, m_type = %x, m_next = %p.\n", (void *)m, m->m_len, m->m_type, (void *)m->m_next);
+ if (m->m_flags & M_EXT)
+ SCTP_DEBUG_USR(SCTP_DEBUG_USR, "%p: extend_size = %d, extend_buffer = %p, ref_cnt = %d.\n", (void *)m, m->m_ext.ext_size, (void *)m->m_ext.ext_buf, *(m->m_ext.ref_cnt));
+ }
+}
+#endif
+
+/*
+ * Free an entire chain of mbufs and associated external buffers, if
+ * applicable.
+ */
+void
+m_freem(struct mbuf *mb)
+{
+ while (mb != NULL)
+ mb = m_free(mb);
+}
+
+/*
+ * __Userspace__
+ * clean mbufs with M_EXT storage attached to them
+ * if the reference count hits 1.
+ */
+void
+mb_free_ext(struct mbuf *m)
+{
+
+ int skipmbuf;
+
+ KASSERT((m->m_flags & M_EXT) == M_EXT, ("%s: M_EXT not set", __func__));
+ KASSERT(m->m_ext.ref_cnt != NULL, ("%s: ref_cnt not set", __func__));
+
+ /*
+ * check if the header is embedded in the cluster
+ */
+ skipmbuf = (m->m_flags & M_NOFREE);
+
+ /* Free the external attached storage if this
+ * mbuf is the only reference to it.
+ *__Userspace__ TODO: jumbo frames
+ *
+ */
+ /* NOTE: We had the same code that SCTP_DECREMENT_AND_CHECK_REFCOUNT
+ reduces to here before but the IPHONE malloc commit had changed
+ this to compare to 0 instead of 1 (see next line). Why?
+ . .. this caused a huge memory leak in Linux.
+ */
+#ifdef IPHONE
+ if (atomic_fetchadd_int(m->m_ext.ref_cnt, -1) == 0)
+#else
+ if (SCTP_DECREMENT_AND_CHECK_REFCOUNT(m->m_ext.ref_cnt))
+#endif
+ {
+ if (m->m_ext.ext_type == EXT_CLUSTER){
+#if defined(SCTP_SIMPLE_ALLOCATOR)
+ mb_dtor_clust(m->m_ext.ext_buf, &clust_mb_args);
+#endif
+ SCTP_ZONE_FREE(zone_clust, m->m_ext.ext_buf);
+ SCTP_ZONE_FREE(zone_ext_refcnt, (u_int*)m->m_ext.ref_cnt);
+ m->m_ext.ref_cnt = NULL;
+ }
+ }
+
+ if (skipmbuf)
+ return;
+
+
+ /* __Userspace__ Also freeing the storage for ref_cnt
+ * Free this mbuf back to the mbuf zone with all m_ext
+ * information purged.
+ */
+ m->m_ext.ext_buf = NULL;
+ m->m_ext.ext_free = NULL;
+ m->m_ext.ext_args = NULL;
+ m->m_ext.ref_cnt = NULL;
+ m->m_ext.ext_size = 0;
+ m->m_ext.ext_type = 0;
+ m->m_flags &= ~M_EXT;
+#if defined(SCTP_SIMPLE_ALLOCATOR)
+ mb_dtor_mbuf(m, NULL);
+#endif
+ SCTP_ZONE_FREE(zone_mbuf, m);
+
+ /*umem_cache_free(zone_mbuf, m);*/
+}
+
+/*
+ * "Move" mbuf pkthdr from "from" to "to".
+ * "from" must have M_PKTHDR set, and "to" must be empty.
+ */
+void
+m_move_pkthdr(struct mbuf *to, struct mbuf *from)
+{
+
+ to->m_flags = (from->m_flags & M_COPYFLAGS) | (to->m_flags & M_EXT);
+ if ((to->m_flags & M_EXT) == 0)
+ to->m_data = to->m_pktdat;
+ to->m_pkthdr = from->m_pkthdr; /* especially tags */
+ SLIST_INIT(&from->m_pkthdr.tags); /* purge tags from src */
+ from->m_flags &= ~M_PKTHDR;
+}
+
+
+/*
+ * Rearange an mbuf chain so that len bytes are contiguous
+ * and in the data area of an mbuf (so that mtod and dtom
+ * will work for a structure of size len). Returns the resulting
+ * mbuf chain on success, frees 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.
+ */
+struct mbuf *
+m_pullup(struct mbuf *n, int len)
+{
+ struct mbuf *m;
+ int count;
+ int space;
+
+ /*
+ * 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 ((n->m_flags & M_EXT) == 0 &&
+ n->m_data + len < &n->m_dat[MLEN] && n->m_next) {
+ if (n->m_len >= len)
+ return (n);
+ m = n;
+ n = n->m_next;
+ len -= m->m_len;
+ } else {
+ if (len > MHLEN)
+ goto bad;
+ MGET(m, M_NOWAIT, n->m_type);
+ if (m == NULL)
+ goto bad;
+ m->m_len = 0;
+ if (n->m_flags & M_PKTHDR)
+ M_MOVE_PKTHDR(m, n);
+ }
+ space = &m->m_dat[MLEN] - (m->m_data + m->m_len);
+ do {
+ count = min(min(max(len, max_protohdr), space), n->m_len);
+ bcopy(mtod(n, caddr_t), mtod(m, caddr_t) + m->m_len,
+ (u_int)count);
+ len -= count;
+ m->m_len += count;
+ n->m_len -= count;
+ space -= count;
+ if (n->m_len)
+ n->m_data += count;
+ else
+ n = m_free(n);
+ } while (len > 0 && n);
+ if (len > 0) {
+ (void) m_free(m);
+ goto bad;
+ }
+ m->m_next = n;
+ return (m);
+bad:
+ m_freem(n);
+ mbstat.m_mpfail++; /* XXX: No consistency. */
+ return (NULL);
+}
+
+
+static struct mbuf *
+m_dup1(struct mbuf *m, int off, int len, int wait)
+{
+ struct mbuf *n = NULL;
+ int copyhdr;
+
+ if (len > MCLBYTES)
+ return NULL;
+ if (off == 0 && (m->m_flags & M_PKTHDR) != 0)
+ copyhdr = 1;
+ else
+ copyhdr = 0;
+ if (len >= MINCLSIZE) {
+ if (copyhdr == 1) {
+ m_clget(n, wait); /* TODO: include code for copying the header */
+ m_dup_pkthdr(n, m, wait);
+ } else
+ m_clget(n, wait);
+ } else {
+ if (copyhdr == 1)
+ n = m_gethdr(wait, m->m_type);
+ else
+ n = m_get(wait, m->m_type);
+ }
+ if (!n)
+ return NULL; /* ENOBUFS */
+
+ if (copyhdr && !m_dup_pkthdr(n, m, wait)) {
+ m_free(n);
+ return NULL;
+ }
+ m_copydata(m, off, len, mtod(n, caddr_t));
+ n->m_len = len;
+ return n;
+}
+
+
+/* Taken from sys/kern/uipc_mbuf2.c */
+struct mbuf *
+m_pulldown(struct mbuf *m, int off, int len, int *offp)
+{
+ struct mbuf *n, *o;
+ int hlen, tlen, olen;
+ int writable;
+
+ /* check invalid arguments. */
+ KASSERT(m, ("m == NULL in m_pulldown()"));
+ if (len > MCLBYTES) {
+ m_freem(m);
+ return NULL; /* impossible */
+ }
+
+#ifdef PULLDOWN_DEBUG
+ {
+ struct mbuf *t;
+ SCTP_DEBUG_USR(SCTP_DEBUG_USR, "before:");
+ for (t = m; t; t = t->m_next)
+ SCTP_DEBUG_USR(SCTP_DEBUG_USR, " %d", t->m_len);
+ SCTP_DEBUG_USR(SCTP_DEBUG_USR, "\n");
+ }
+#endif
+ n = m;
+ 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 */
+ }
+
+ writable = 0;
+ if ((n->m_flags & M_EXT) == 0 ||
+ (n->m_ext.ext_type == EXT_CLUSTER && M_WRITABLE(n)))
+ writable = 1;
+
+ /*
+ * the target data is on <n, off>.
+ * if we got enough data on the mbuf "n", we're done.
+ */
+ if ((off == 0 || offp) && len <= n->m_len - off && writable)
+ goto ok;
+
+ /*
+ * 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) {
+ o = m_dup1(n, off, n->m_len - off, M_NOWAIT);
+ if (o == NULL) {
+ m_freem(m);
+ return NULL; /* ENOBUFS */
+ }
+ n->m_len = off;
+ o->m_next = n->m_next;
+ n->m_next = o;
+ n = n->m_next;
+ off = 0;
+ goto ok;
+ }
+ /*
+ * 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.
+ */
+ hlen = n->m_len - off;
+ tlen = len - hlen;
+
+ /*
+ * ensure that we have enough trailing data on mbuf chain.
+ * if not, we can do nothing about the chain.
+ */
+ olen = 0;
+ for (o = n->m_next; o != NULL; o = o->m_next)
+ olen += o->m_len;
+ if (hlen + olen < len) {
+ m_freem(m);
+ return NULL; /* mbuf chain too short */
+ }
+
+ /*
+ * easy cases first.
+ * we need to use m_copydata() to get data from <n->m_next, 0>.
+ */
+ if ((off == 0 || offp) && M_TRAILINGSPACE(n) >= tlen
+ && writable) {
+ m_copydata(n->m_next, 0, tlen, mtod(n, caddr_t) + n->m_len);
+ n->m_len += tlen;
+ m_adj(n->m_next, tlen);
+ goto ok;
+ }
+
+ if ((off == 0 || offp) && M_LEADINGSPACE(n->m_next) >= hlen
+ && writable) {
+ 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);
+ n->m_len -= hlen;
+ n = n->m_next;
+ off = 0;
+ goto ok;
+ }
+
+ /*
+ * now, we need to do the hard way. don't m_copy as there's no room
+ * on both end.
+ */
+ if (len > MLEN)
+ m_clget(o, M_NOWAIT);
+ /* o = m_getcl(M_NOWAIT, m->m_type, 0);*/
+ else
+ o = m_get(M_NOWAIT, m->m_type);
+ if (!o) {
+ m_freem(m);
+ return NULL; /* ENOBUFS */
+ }
+ /* get hlen from <n, off> into <o, 0> */
+ o->m_len = hlen;
+ bcopy(mtod(n, caddr_t) + off, mtod(o, caddr_t), hlen);
+ n->m_len -= hlen;
+ /* get tlen from <n->m_next, 0> into <o, hlen> */
+ m_copydata(n->m_next, 0, tlen, mtod(o, caddr_t) + o->m_len);
+ o->m_len += tlen;
+ m_adj(n->m_next, tlen);
+ o->m_next = n->m_next;
+ n->m_next = o;
+ n = o;
+ off = 0;
+ok:
+#ifdef PULLDOWN_DEBUG
+ {
+ struct mbuf *t;
+ SCTP_DEBUG_USR(SCTP_DEBUG_USR, "after:");
+ for (t = m; t; t = t->m_next)
+ SCTP_DEBUG_USR(SCTP_DEBUG_USR, "%c%d", t == n ? '*' : ' ', t->m_len);
+ SCTP_DEBUG_USR(SCTP_DEBUG_USR, " (off=%d)\n", off);
+ }
+#endif
+ if (offp)
+ *offp = off;
+ return n;
+}
+
+/*
+ * Attach the the cluster from *m to *n, set up m_ext in *n
+ * and bump the refcount of the cluster.
+ */
+static void
+mb_dupcl(struct mbuf *n, struct mbuf *m)
+{
+ KASSERT((m->m_flags & M_EXT) == M_EXT, ("%s: M_EXT not set", __func__));
+ KASSERT(m->m_ext.ref_cnt != NULL, ("%s: ref_cnt not set", __func__));
+ KASSERT((n->m_flags & M_EXT) == 0, ("%s: M_EXT set", __func__));
+
+ if (*(m->m_ext.ref_cnt) == 1)
+ *(m->m_ext.ref_cnt) += 1;
+ else
+ atomic_add_int(m->m_ext.ref_cnt, 1);
+ n->m_ext.ext_buf = m->m_ext.ext_buf;
+ n->m_ext.ext_free = m->m_ext.ext_free;
+ n->m_ext.ext_args = m->m_ext.ext_args;
+ n->m_ext.ext_size = m->m_ext.ext_size;
+ n->m_ext.ref_cnt = m->m_ext.ref_cnt;
+ n->m_ext.ext_type = m->m_ext.ext_type;
+ n->m_flags |= M_EXT;
+}
+
+
+/*
+ * Make a copy of an mbuf chain starting "off0" bytes from the beginning,
+ * continuing for "len" bytes. If len is M_COPYALL, copy to end of mbuf.
+ * The wait parameter is a choice of M_TRYWAIT/M_NOWAIT from caller.
+ * Note that the copy is read-only, because clusters are not copied,
+ * only their reference counts are incremented.
+ */
+
+struct mbuf *
+m_copym(struct mbuf *m, int off0, int len, int wait)
+{
+ struct mbuf *n, **np;
+ int off = off0;
+ struct mbuf *top;
+ int copyhdr = 0;
+
+ KASSERT(off >= 0, ("m_copym, negative off %d", off));
+ KASSERT(len >= 0, ("m_copym, negative len %d", len));
+
+ if (off == 0 && m->m_flags & M_PKTHDR)
+ copyhdr = 1;
+ while (off > 0) {
+ KASSERT(m != NULL, ("m_copym, offset > size of mbuf chain"));
+ if (off < m->m_len)
+ break;
+ off -= m->m_len;
+ m = m->m_next;
+ }
+ np = &top;
+ top = 0;
+ while (len > 0) {
+ if (m == NULL) {
+ KASSERT(len == M_COPYALL, ("m_copym, length > size of mbuf chain"));
+ break;
+ }
+ if (copyhdr)
+ MGETHDR(n, wait, m->m_type);
+ else
+ MGET(n, wait, m->m_type);
+ *np = n;
+ if (n == NULL)
+ goto nospace;
+ if (copyhdr) {
+ if (!m_dup_pkthdr(n, m, wait))
+ goto nospace;
+ if (len == M_COPYALL)
+ n->m_pkthdr.len -= off0;
+ else
+ n->m_pkthdr.len = len;
+ copyhdr = 0;
+ }
+ n->m_len = min(len, m->m_len - off);
+ if (m->m_flags & M_EXT) {
+ n->m_data = m->m_data + off;
+ mb_dupcl(n, m);
+ } else
+ bcopy(mtod(m, caddr_t)+off, mtod(n, caddr_t),
+ (u_int)n->m_len);
+ if (len != M_COPYALL)
+ len -= n->m_len;
+ off = 0;
+ m = m->m_next;
+ np = &n->m_next;
+ }
+ if (top == NULL)
+ mbstat.m_mcfail++; /* XXX: No consistency. */
+
+ return (top);
+nospace:
+ m_freem(top);
+ mbstat.m_mcfail++; /* XXX: No consistency. */
+ return (NULL);
+}
+
+
+int
+m_tag_copy_chain(struct mbuf *to, struct mbuf *from, int how)
+{
+ struct m_tag *p, *t, *tprev = NULL;
+
+ KASSERT(to && from, ("m_tag_copy_chain: null argument, to %p from %p", (void *)to, (void *)from));
+ m_tag_delete_chain(to, NULL);
+ SLIST_FOREACH(p, &from->m_pkthdr.tags, m_tag_link) {
+ t = m_tag_copy(p, how);
+ if (t == NULL) {
+ m_tag_delete_chain(to, NULL);
+ return 0;
+ }
+ if (tprev == NULL)
+ SLIST_INSERT_HEAD(&to->m_pkthdr.tags, t, m_tag_link);
+ else
+ SLIST_INSERT_AFTER(tprev, t, m_tag_link);
+ tprev = t;
+ }
+ return 1;
+}
+
+/*
+ * Duplicate "from"'s mbuf pkthdr in "to".
+ * "from" must have M_PKTHDR set, and "to" must be empty.
+ * In particular, this does a deep copy of the packet tags.
+ */
+int
+m_dup_pkthdr(struct mbuf *to, struct mbuf *from, int how)
+{
+
+ to->m_flags = (from->m_flags & M_COPYFLAGS) | (to->m_flags & M_EXT);
+ if ((to->m_flags & M_EXT) == 0)
+ to->m_data = to->m_pktdat;
+ to->m_pkthdr = from->m_pkthdr;
+ SLIST_INIT(&to->m_pkthdr.tags);
+ return (m_tag_copy_chain(to, from, MBTOM(how)));
+}
+
+/* Copy a single tag. */
+struct m_tag *
+m_tag_copy(struct m_tag *t, int how)
+{
+ struct m_tag *p;
+
+ KASSERT(t, ("m_tag_copy: null tag"));
+ p = m_tag_alloc(t->m_tag_cookie, t->m_tag_id, t->m_tag_len, how);
+ if (p == NULL)
+ return (NULL);
+ bcopy(t + 1, p + 1, t->m_tag_len); /* Copy the data */
+ return p;
+}
+
+/* Get a packet tag structure along with specified data following. */
+struct m_tag *
+m_tag_alloc(u_int32_t cookie, int type, int len, int wait)
+{
+ struct m_tag *t;
+
+ if (len < 0)
+ return NULL;
+ t = malloc(len + sizeof(struct m_tag));
+ if (t == NULL)
+ return NULL;
+ m_tag_setup(t, cookie, type, len);
+ t->m_tag_free = m_tag_free_default;
+ return t;
+}
+
+/* Free a packet tag. */
+void
+m_tag_free_default(struct m_tag *t)
+{
+ free(t);
+}
+
+/*
+ * Copy data from a buffer back into the indicated mbuf chain,
+ * starting "off" bytes from the beginning, extending the mbuf
+ * chain if necessary.
+ */
+void
+m_copyback(struct mbuf *m0, int off, int len, caddr_t cp)
+{
+ int mlen;
+ struct mbuf *m = m0, *n;
+ int totlen = 0;
+
+ if (m0 == NULL)
+ return;
+ while (off > (mlen = m->m_len)) {
+ off -= mlen;
+ totlen += mlen;
+ if (m->m_next == NULL) {
+ n = m_get(M_NOWAIT, m->m_type);
+ if (n == NULL)
+ goto out;
+ bzero(mtod(n, caddr_t), MLEN);
+ n->m_len = min(MLEN, len + off);
+ m->m_next = n;
+ }
+ m = m->m_next;
+ }
+ while (len > 0) {
+ mlen = min (m->m_len - off, len);
+ bcopy(cp, off + mtod(m, caddr_t), (u_int)mlen);
+ cp += mlen;
+ len -= mlen;
+ mlen += off;
+ off = 0;
+ totlen += mlen;
+ if (len == 0)
+ break;
+ if (m->m_next == NULL) {
+ n = m_get(M_NOWAIT, m->m_type);
+ if (n == NULL)
+ break;
+ n->m_len = min(MLEN, len);
+ m->m_next = n;
+ }
+ m = m->m_next;
+ }
+out: if (((m = m0)->m_flags & M_PKTHDR) && (m->m_pkthdr.len < totlen))
+ m->m_pkthdr.len = totlen;
+}
+
+
+/*
+ * Lesser-used path for M_PREPEND:
+ * allocate new mbuf to prepend to chain,
+ * copy junk along.
+ */
+struct mbuf *
+m_prepend(struct mbuf *m, int len, int how)
+{
+ struct mbuf *mn;
+
+ if (m->m_flags & M_PKTHDR)
+ MGETHDR(mn, how, m->m_type);
+ else
+ MGET(mn, how, m->m_type);
+ if (mn == NULL) {
+ m_freem(m);
+ return (NULL);
+ }
+ if (m->m_flags & M_PKTHDR)
+ M_MOVE_PKTHDR(mn, m);
+ mn->m_next = m;
+ m = mn;
+ if(m->m_flags & M_PKTHDR) {
+ if (len < MHLEN)
+ MH_ALIGN(m, len);
+ } else {
+ if (len < MLEN)
+ M_ALIGN(m, len);
+ }
+ m->m_len = len;
+ return (m);
+}
+
+/*
+ * Copy data from an mbuf chain starting "off" bytes from the beginning,
+ * continuing for "len" bytes, into the indicated buffer.
+ */
+void
+m_copydata(const struct mbuf *m, int off, int len, caddr_t cp)
+{
+ u_int count;
+
+ KASSERT(off >= 0, ("m_copydata, negative off %d", off));
+ KASSERT(len >= 0, ("m_copydata, negative len %d", len));
+ while (off > 0) {
+ KASSERT(m != NULL, ("m_copydata, offset > size of mbuf chain"));
+ if (off < m->m_len)
+ break;
+ off -= m->m_len;
+ m = m->m_next;
+ }
+ while (len > 0) {
+ KASSERT(m != NULL, ("m_copydata, length > size of mbuf chain"));
+ count = min(m->m_len - off, len);
+ bcopy(mtod(m, caddr_t) + off, cp, count);
+ len -= count;
+ cp += count;
+ off = 0;
+ m = m->m_next;
+ }
+}
+
+
+/*
+ * Concatenate mbuf chain n to m.
+ * Both chains must be of the same type (e.g. MT_DATA).
+ * Any m_pkthdr is not updated.
+ */
+void
+m_cat(struct mbuf *m, struct mbuf *n)
+{
+ while (m->m_next)
+ m = m->m_next;
+ while (n) {
+ if (m->m_flags & M_EXT ||
+ m->m_data + m->m_len + n->m_len >= &m->m_dat[MLEN]) {
+ /* just join the two chains */
+ m->m_next = n;
+ return;
+ }
+ /* splat the data from one into the other */
+ bcopy(mtod(n, caddr_t), mtod(m, caddr_t) + m->m_len, (u_int)n->m_len);
+ m->m_len += n->m_len;
+ n = m_free(n);
+ }
+}
+
+
+void
+m_adj(struct mbuf *mp, int req_len)
+{
+ int len = req_len;
+ struct mbuf *m;
+ int count;
+
+ if ((m = mp) == NULL)
+ return;
+ if (len >= 0) {
+ /*
+ * Trim from head.
+ */
+ while (m != NULL && len > 0) {
+ if (m->m_len <= len) {
+ len -= m->m_len;
+ m->m_len = 0;
+ m = m->m_next;
+ } else {
+ m->m_len -= len;
+ m->m_data += len;
+ len = 0;
+ }
+ }
+ m = mp;
+ if (mp->m_flags & M_PKTHDR)
+ m->m_pkthdr.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->m_len;
+ if (m->m_next == (struct mbuf *)0)
+ break;
+ m = m->m_next;
+ }
+ if (m->m_len >= len) {
+ m->m_len -= len;
+ if (mp->m_flags & M_PKTHDR)
+ mp->m_pkthdr.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 (m->m_flags & M_PKTHDR)
+ m->m_pkthdr.len = count;
+ for (; m; m = m->m_next) {
+ if (m->m_len >= count) {
+ m->m_len = count;
+ if (m->m_next != NULL) {
+ m_freem(m->m_next);
+ m->m_next = NULL;
+ }
+ break;
+ }
+ count -= m->m_len;
+ }
+ }
+}
+
+
+/* m_split is used within sctp_handle_cookie_echo. */
+
+/*
+ * Partition an mbuf chain in two pieces, returning the tail --
+ * all but the first len0 bytes. In case of failure, it returns NULL and
+ * attempts to restore the chain to its original state.
+ *
+ * Note that the resulting mbufs might be read-only, because the new
+ * mbuf can end up sharing an mbuf cluster with the original mbuf if
+ * the "breaking point" happens to lie within a cluster mbuf. Use the
+ * M_WRITABLE() macro to check for this case.
+ */
+struct mbuf *
+m_split(struct mbuf *m0, int len0, int wait)
+{
+ struct mbuf *m, *n;
+ u_int len = len0, remain;
+
+ /* MBUF_CHECKSLEEP(wait); */
+ for (m = m0; m && (int)len > m->m_len; m = m->m_next)
+ len -= m->m_len;
+ if (m == NULL)
+ return (NULL);
+ remain = m->m_len - len;
+ if (m0->m_flags & M_PKTHDR) {
+ MGETHDR(n, wait, m0->m_type);
+ if (n == NULL)
+ return (NULL);
+ n->m_pkthdr.rcvif = m0->m_pkthdr.rcvif;
+ n->m_pkthdr.len = m0->m_pkthdr.len - len0;
+ m0->m_pkthdr.len = len0;
+ if (m->m_flags & M_EXT)
+ goto extpacket;
+ if (remain > MHLEN) {
+ /* m can't be the lead packet */
+ MH_ALIGN(n, 0);
+ n->m_next = m_split(m, len, wait);
+ if (n->m_next == NULL) {
+ (void) m_free(n);
+ return (NULL);
+ } else {
+ n->m_len = 0;
+ return (n);
+ }
+ } else
+ MH_ALIGN(n, remain);
+ } else if (remain == 0) {
+ n = m->m_next;
+ m->m_next = NULL;
+ return (n);
+ } else {
+ MGET(n, wait, m->m_type);
+ if (n == NULL)
+ return (NULL);
+ M_ALIGN(n, remain);
+ }
+extpacket:
+ if (m->m_flags & M_EXT) {
+ n->m_data = m->m_data + len;
+ mb_dupcl(n, m);
+ } else {
+ bcopy(mtod(m, caddr_t) + len, mtod(n, caddr_t), remain);
+ }
+ n->m_len = remain;
+ m->m_len = len;
+ n->m_next = m->m_next;
+ m->m_next = NULL;
+ return (n);
+}
+
+
+
+
+int
+pack_send_buffer(caddr_t buffer, struct mbuf* mb){
+
+ int count_to_copy;
+ int total_count_copied = 0;
+ int offset = 0;
+
+ do {
+ count_to_copy = mb->m_len;
+ bcopy(mtod(mb, caddr_t), buffer+offset, count_to_copy);
+ offset += count_to_copy;
+ total_count_copied += count_to_copy;
+ mb = mb->m_next;
+ } while(mb);
+
+ return (total_count_copied);
+}