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2b44043265
The two new variables "arp_requested" and "expiration_date" in the mbuf structure have been added after the variable-sized "m_dat_" array. The variables have to be added before the m_dat_ array instead. Without this patch, the expiration_date gets clobbered by code that accesses the m_dat_ array. I experienced this problem with the code in slirp/tftp.c: The tftp_send_data() function created a new packet with the m_get() function (which fills-in a default expiration_date value). Then the TFTP code cleared the data section of the packet, which accidentially also cleared the expiration_date. This zeroed expiration_date then finally causes the packet to be discarded during if_start(), so that TFTP packets were not transmitted anymore. [Jan: added comment as suggested by Fabien ] CC: Fabien Chouteau <chouteau@adacore.com> Signed-off-by: Thomas Huth <thuth@linux.vnet.ibm.com> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
128 lines
4.3 KiB
C
128 lines
4.3 KiB
C
/*
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* Copyright (c) 1982, 1986, 1988, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* @(#)mbuf.h 8.3 (Berkeley) 1/21/94
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* mbuf.h,v 1.9 1994/11/14 13:54:20 bde Exp
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*/
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#ifndef _MBUF_H_
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#define _MBUF_H_
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#define MINCSIZE 4096 /* Amount to increase mbuf if too small */
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/*
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* Macros for type conversion
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* mtod(m,t) - convert mbuf pointer to data pointer of correct type
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*/
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#define mtod(m,t) ((t)(m)->m_data)
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/* XXX About mbufs for slirp:
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* Only one mbuf is ever used in a chain, for each "cell" of data.
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* m_nextpkt points to the next packet, if fragmented.
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* If the data is too large, the M_EXT is used, and a larger block
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* is alloced. Therefore, m_free[m] must check for M_EXT and if set
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* free the m_ext. This is inefficient memory-wise, but who cares.
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*/
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/* XXX should union some of these! */
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/* header at beginning of each mbuf: */
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struct m_hdr {
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struct mbuf *mh_next; /* Linked list of mbufs */
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struct mbuf *mh_prev;
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struct mbuf *mh_nextpkt; /* Next packet in queue/record */
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struct mbuf *mh_prevpkt; /* Flags aren't used in the output queue */
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int mh_flags; /* Misc flags */
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int mh_size; /* Size of data */
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struct socket *mh_so;
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caddr_t mh_data; /* Location of data */
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int mh_len; /* Amount of data in this mbuf */
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};
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/*
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* How much room is in the mbuf, from m_data to the end of the mbuf
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*/
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#define M_ROOM(m) ((m->m_flags & M_EXT)? \
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(((m)->m_ext + (m)->m_size) - (m)->m_data) \
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: \
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(((m)->m_dat + (m)->m_size) - (m)->m_data))
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/*
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* How much free room there is
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*/
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#define M_FREEROOM(m) (M_ROOM(m) - (m)->m_len)
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#define M_TRAILINGSPACE M_FREEROOM
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struct mbuf {
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struct m_hdr m_hdr;
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Slirp *slirp;
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bool arp_requested;
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uint64_t expiration_date;
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/* start of dynamic buffer area, must be last element */
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union M_dat {
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char m_dat_[1]; /* ANSI don't like 0 sized arrays */
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char *m_ext_;
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} M_dat;
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};
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#define m_next m_hdr.mh_next
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#define m_prev m_hdr.mh_prev
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#define m_nextpkt m_hdr.mh_nextpkt
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#define m_prevpkt m_hdr.mh_prevpkt
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#define m_flags m_hdr.mh_flags
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#define m_len m_hdr.mh_len
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#define m_data m_hdr.mh_data
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#define m_size m_hdr.mh_size
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#define m_dat M_dat.m_dat_
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#define m_ext M_dat.m_ext_
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#define m_so m_hdr.mh_so
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#define ifq_prev m_prev
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#define ifq_next m_next
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#define ifs_prev m_prevpkt
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#define ifs_next m_nextpkt
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#define ifq_so m_so
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#define M_EXT 0x01 /* m_ext points to more (malloced) data */
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#define M_FREELIST 0x02 /* mbuf is on free list */
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#define M_USEDLIST 0x04 /* XXX mbuf is on used list (for dtom()) */
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#define M_DOFREE 0x08 /* when m_free is called on the mbuf, free()
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* it rather than putting it on the free list */
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void m_init(Slirp *);
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struct mbuf * m_get(Slirp *);
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void m_free(struct mbuf *);
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void m_cat(register struct mbuf *, register struct mbuf *);
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void m_inc(struct mbuf *, int);
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void m_adj(struct mbuf *, int);
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int m_copy(struct mbuf *, struct mbuf *, int, int);
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struct mbuf * dtom(Slirp *, void *);
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#endif
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