gstreamer/ext/sctp/usrsctp/usrsctplib/user_mbuf.c
Tim-Philipp Müller f4538e24b6 sctp: import internal copy of usrsctp library
There are problems with global shared state and no API stability
guarantees, and we can't rely on distros shipping the fixes we
need. Both firefox and Chrome bundle their own copies too.

Imported from https://github.com/sctplab/usrsctp,
commit 547d3b46c64876c0336b9eef297fda58dbe1adaf
Date: Thu Jul 23 21:49:32 2020 +0200

Fixes https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/-/issues/870

Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/-/merge_requests/1465>
2020-08-14 01:32:45 +01:00

1566 lines
37 KiB
C

/*-
* 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"
#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_initialize() */
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 void
clust_constructor_dup(caddr_t m_clust, struct mbuf* m)
{
u_int *refcnt;
int type, size;
if (m == NULL) {
return;
}
/* 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 !defined(SCTP_SIMPLE_ALLOCATOR)
if (refcnt == NULL) {
umem_reap();
refcnt = SCTP_ZONE_GET(zone_ext_refcnt, u_int);
/*refcnt = (u_int *)umem_cache_alloc(zone_ext_refcnt, UMEM_DEFAULT);*/
}
#endif
*refcnt = 1;
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;
}
/* __Userspace__ */
void
m_clget(struct mbuf *m, int how)
{
caddr_t mclust_ret;
#if defined(SCTP_SIMPLE_ALLOCATOR)
struct clust_args clust_mb_args_l;
#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_l.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_l, 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
}
struct mbuf *
m_getm2(struct mbuf *m, int len, int how, short type, int flags, int allonebuf)
{
struct mbuf *mb, *nm = NULL, *mtail = NULL;
int size, mbuf_threshold, space_needed = len;
KASSERT(len >= 0, ("%s: len is < 0", __func__));
/* Validate flags. */
flags &= (M_PKTHDR | M_EOR);
/* Packet header mbuf must be first in chain. */
if ((flags & M_PKTHDR) && m != NULL) {
flags &= ~M_PKTHDR;
}
if (allonebuf == 0)
mbuf_threshold = SCTP_BASE_SYSCTL(sctp_mbuf_threshold_count);
else
mbuf_threshold = 1;
/* Loop and append maximum sized mbufs to the chain tail. */
while (len > 0) {
if ((!allonebuf && len >= MCLBYTES) || (len > (int)(((mbuf_threshold - 1) * MLEN) + MHLEN))) {
mb = m_gethdr(how, type);
MCLGET(mb, how);
size = MCLBYTES;
/* SCTP_BUF_LEN(mb) = MCLBYTES; */
} else if (flags & M_PKTHDR) {
mb = m_gethdr(how, type);
if (len < MHLEN) {
size = len;
} else {
size = MHLEN;
}
} else {
mb = m_get(how, type);
if (len < MLEN) {
size = len;
} else {
size = MLEN;
}
}
/* Fail the whole operation if one mbuf can't be allocated. */
if (mb == NULL) {
if (nm != NULL)
m_freem(nm);
return (NULL);
}
if (allonebuf != 0 && size < space_needed) {
m_freem(mb);
return (NULL);
}
/* Book keeping. */
len -= size;
if (mtail != NULL)
mtail->m_next = mb;
else
nm = mb;
mtail = mb;
flags &= ~M_PKTHDR; /* Only valid on the first mbuf. */
}
if (flags & M_EOR) {
mtail->m_flags |= M_EOR; /* Only valid on the last mbuf. */
}
/* If mbuf was supplied, append new chain to the end of it. */
if (m != NULL) {
for (mtail = m; mtail->m_next != NULL; mtail = mtail->m_next);
mtail->m_next = nm;
mtail->m_flags &= ~M_EOR;
} else {
m = nm;
}
return (m);
}
/*
* Copy the contents of uio into a properly sized mbuf chain.
*/
struct mbuf *
m_uiotombuf(struct uio *uio, int how, int len, int align, int flags)
{
struct mbuf *m, *mb;
int error, length;
ssize_t total;
int progress = 0;
/*
* len can be zero or an arbitrary large value bound by
* the total data supplied by the uio.
*/
if (len > 0)
total = min(uio->uio_resid, len);
else
total = uio->uio_resid;
/*
* The smallest unit returned by m_getm2() is a single mbuf
* with pkthdr. We can't align past it.
*/
if (align >= MHLEN)
return (NULL);
/*
* Give us the full allocation or nothing.
* If len is zero return the smallest empty mbuf.
*/
m = m_getm2(NULL, (int)max(total + align, 1), how, MT_DATA, flags, 0);
if (m == NULL)
return (NULL);
m->m_data += align;
/* Fill all mbufs with uio data and update header information. */
for (mb = m; mb != NULL; mb = mb->m_next) {
length = (int)min(M_TRAILINGSPACE(mb), total - progress);
error = uiomove(mtod(mb, void *), length, uio);
if (error) {
m_freem(m);
return (NULL);
}
mb->m_len = length;
progress += length;
if (flags & M_PKTHDR)
m->m_pkthdr.len += length;
}
KASSERT(progress == total, ("%s: progress != total", __func__));
return (m);
}
u_int
m_length(struct mbuf *m0, struct mbuf **last)
{
struct mbuf *m;
u_int len;
len = 0;
for (m = m0; m != NULL; m = m->m_next) {
len += m->m_len;
if (m->m_next == NULL)
break;
}
if (last != NULL)
*last = m;
return (len);
}
struct mbuf *
m_last(struct mbuf *m)
{
while (m->m_next) {
m = m->m_next;
}
return (m);
}
/*
* 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, uint32_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 **************/
void
mbuf_initialize(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?
*
*/
}
/*
* __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 = (int)(&m->m_dat[MLEN] - (m->m_data + m->m_len));
do {
count = min(min(max(len, max_protohdr), space), n->m_len);
memcpy(mtod(m, caddr_t) + m->m_len,mtod(n, caddr_t), (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);
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;
memcpy( mtod(n->m_next, caddr_t), mtod(n, caddr_t) + off,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;
memcpy(mtod(o, caddr_t), mtod(n, caddr_t) + off, 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));
KASSERT(m != NULL, ("m_copym, m is NULL"));
#if !defined(INVARIANTS)
if (m == NULL) {
return (NULL);
}
#endif
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
memcpy(mtod(n, caddr_t), mtod(m, caddr_t) + off, (u_int)n->m_len);
if (len != M_COPYALL)
len -= n->m_len;
off = 0;
m = m->m_next;
np = &n->m_next;
}
return (top);
nospace:
m_freem(top);
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)
{
KASSERT(to, ("m_dup_pkthdr: to is NULL"));
KASSERT(from, ("m_dup_pkthdr: from is NULL"));
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);
memcpy(p + 1, t + 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(uint32_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;
memset(mtod(n, caddr_t), 0, 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);
memcpy(off + mtod(m, caddr_t), cp, (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);
memcpy(cp, mtod(m, caddr_t) + off, 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 */
memcpy(mtod(m, caddr_t) + m->m_len, mtod(n, caddr_t), (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 {
memcpy(mtod(n, caddr_t), mtod(m, caddr_t) + len, 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;
memcpy(buffer+offset, mtod(mb, caddr_t), count_to_copy);
offset += count_to_copy;
total_count_copied += count_to_copy;
mb = mb->m_next;
} while(mb);
return (total_count_copied);
}