and fix confusing datasize name into gapsize in m_inc. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
239 lines
5 KiB
C
239 lines
5 KiB
C
/*
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* Copyright (c) 1995 Danny Gasparovski
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*
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* Please read the file COPYRIGHT for the
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* terms and conditions of the copyright.
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*/
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/*
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* mbuf's in SLiRP are much simpler than the real mbufs in
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* FreeBSD. They are fixed size, determined by the MTU,
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* so that one whole packet can fit. Mbuf's cannot be
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* chained together. If there's more data than the mbuf
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* could hold, an external g_malloced buffer is pointed to
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* by m_ext (and the data pointers) and M_EXT is set in
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* the flags
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*/
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#include "qemu/osdep.h"
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#include "slirp.h"
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#define MBUF_THRESH 30
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/*
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* Find a nice value for msize
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*/
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#define SLIRP_MSIZE\
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(offsetof(struct mbuf, m_dat) + IF_MAXLINKHDR + TCPIPHDR_DELTA + IF_MTU)
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void
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m_init(Slirp *slirp)
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{
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slirp->m_freelist.qh_link = slirp->m_freelist.qh_rlink = &slirp->m_freelist;
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slirp->m_usedlist.qh_link = slirp->m_usedlist.qh_rlink = &slirp->m_usedlist;
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}
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void m_cleanup(Slirp *slirp)
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{
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struct mbuf *m, *next;
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m = (struct mbuf *) slirp->m_usedlist.qh_link;
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while ((struct quehead *) m != &slirp->m_usedlist) {
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next = m->m_next;
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if (m->m_flags & M_EXT) {
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g_free(m->m_ext);
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}
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g_free(m);
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m = next;
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}
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m = (struct mbuf *) slirp->m_freelist.qh_link;
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while ((struct quehead *) m != &slirp->m_freelist) {
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next = m->m_next;
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g_free(m);
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m = next;
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}
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}
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/*
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* Get an mbuf from the free list, if there are none
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* allocate one
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*
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* Because fragmentation can occur if we alloc new mbufs and
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* free old mbufs, we mark all mbufs above mbuf_thresh as M_DOFREE,
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* which tells m_free to actually g_free() it
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*/
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struct mbuf *
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m_get(Slirp *slirp)
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{
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register struct mbuf *m;
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int flags = 0;
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DEBUG_CALL("m_get");
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if (slirp->m_freelist.qh_link == &slirp->m_freelist) {
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m = g_malloc(SLIRP_MSIZE);
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slirp->mbuf_alloced++;
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if (slirp->mbuf_alloced > MBUF_THRESH)
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flags = M_DOFREE;
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m->slirp = slirp;
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} else {
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m = (struct mbuf *) slirp->m_freelist.qh_link;
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remque(m);
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}
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/* Insert it in the used list */
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insque(m,&slirp->m_usedlist);
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m->m_flags = (flags | M_USEDLIST);
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/* Initialise it */
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m->m_size = SLIRP_MSIZE - offsetof(struct mbuf, m_dat);
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m->m_data = m->m_dat;
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m->m_len = 0;
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m->m_nextpkt = NULL;
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m->m_prevpkt = NULL;
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m->resolution_requested = false;
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m->expiration_date = (uint64_t)-1;
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DEBUG_ARG("m = %p", m);
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return m;
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}
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void
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m_free(struct mbuf *m)
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{
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DEBUG_CALL("m_free");
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DEBUG_ARG("m = %p", m);
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if(m) {
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/* Remove from m_usedlist */
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if (m->m_flags & M_USEDLIST)
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remque(m);
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/* If it's M_EXT, free() it */
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if (m->m_flags & M_EXT) {
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g_free(m->m_ext);
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}
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/*
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* Either free() it or put it on the free list
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*/
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if (m->m_flags & M_DOFREE) {
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m->slirp->mbuf_alloced--;
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g_free(m);
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} else if ((m->m_flags & M_FREELIST) == 0) {
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insque(m,&m->slirp->m_freelist);
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m->m_flags = M_FREELIST; /* Clobber other flags */
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}
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} /* if(m) */
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}
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/*
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* Copy data from one mbuf to the end of
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* the other.. if result is too big for one mbuf, allocate
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* an M_EXT data segment
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*/
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void
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m_cat(struct mbuf *m, struct mbuf *n)
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{
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/*
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* If there's no room, realloc
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*/
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if (M_FREEROOM(m) < n->m_len)
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m_inc(m, m->m_len + n->m_len);
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memcpy(m->m_data+m->m_len, n->m_data, n->m_len);
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m->m_len += n->m_len;
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m_free(n);
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}
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/* make m 'size' bytes large from m_data */
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void
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m_inc(struct mbuf *m, int size)
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{
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int gapsize;
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/* some compilers throw up on gotos. This one we can fake. */
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if (M_ROOM(m) > size) {
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return;
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}
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if (m->m_flags & M_EXT) {
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gapsize = m->m_data - m->m_ext;
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m->m_ext = g_realloc(m->m_ext, size + gapsize);
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} else {
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gapsize = m->m_data - m->m_dat;
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m->m_ext = g_malloc(size + gapsize);
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memcpy(m->m_ext, m->m_dat, m->m_size);
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m->m_flags |= M_EXT;
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}
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m->m_data = m->m_ext + gapsize;
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m->m_size = size + gapsize;
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}
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void
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m_adj(struct mbuf *m, int len)
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{
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if (m == NULL)
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return;
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if (len >= 0) {
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/* Trim from head */
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m->m_data += len;
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m->m_len -= len;
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} else {
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/* Trim from tail */
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len = -len;
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m->m_len -= len;
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}
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}
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/*
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* Copy len bytes from m, starting off bytes into n
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*/
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int
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m_copy(struct mbuf *n, struct mbuf *m, int off, int len)
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{
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if (len > M_FREEROOM(n))
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return -1;
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memcpy((n->m_data + n->m_len), (m->m_data + off), len);
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n->m_len += len;
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return 0;
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}
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/*
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* Given a pointer into an mbuf, return the mbuf
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* XXX This is a kludge, I should eliminate the need for it
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* Fortunately, it's not used often
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*/
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struct mbuf *
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dtom(Slirp *slirp, void *dat)
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{
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struct mbuf *m;
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DEBUG_CALL("dtom");
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DEBUG_ARG("dat = %p", dat);
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/* bug corrected for M_EXT buffers */
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for (m = (struct mbuf *) slirp->m_usedlist.qh_link;
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(struct quehead *) m != &slirp->m_usedlist;
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m = m->m_next) {
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if (m->m_flags & M_EXT) {
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if( (char *)dat>=m->m_ext && (char *)dat<(m->m_ext + m->m_size) )
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return m;
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} else {
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if( (char *)dat >= m->m_dat && (char *)dat<(m->m_dat + m->m_size) )
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return m;
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}
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}
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DEBUG_ERROR((dfd, "dtom failed"));
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return (struct mbuf *)0;
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}
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