qemu/slirp/ip_input.c

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/*
* 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.
Remove the advertising clause from the slirp license According to the FSF, the 4-clause BSD license, which slirp is covered under, is not compatible with the GPL or LGPL[1]. [1] http://www.fsf.org/licensing/licenses/index_html#GPLIncompatibleLicenses There are three declared copyright holders in slirp that use the 4-clause BSD license, the Regents of UC Berkley, Danny Gasparovski, and Kelly Price. Below are the appropriate permissions to remove the advertise clause from slirp from each party. Special thanks go to Richard Fontana from Red Hat for contacting all of the necessary authors to resolve this issue! Regents of UC Berkley: From ftp://ftp.cs.berkeley.edu/pub/4bsd/README.Impt.License.Change July 22, 1999 To All Licensees, Distributors of Any Version of BSD: As you know, certain of the Berkeley Software Distribution ("BSD") source code files require that further distributions of products containing all or portions of the software, acknowledge within their advertising materials that such products contain software developed by UC Berkeley and its contributors. Specifically, the provision reads: " * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors." Effective immediately, licensees and distributors are no longer required to include the acknowledgement within advertising materials. Accordingly, the foregoing paragraph of those BSD Unix files containing it is hereby deleted in its entirety. William Hoskins Director, Office of Technology Licensing University of California, Berkeley Danny Gasparovski: Subject: RE: Slirp license Date: Thu, 8 Jan 2009 10:51:00 +1100 From: "Gasparovski, Daniel" <Daniel.Gasparovski@ato.gov.au> To: "Richard Fontana" <rfontana@redhat.com> Hi Richard, I have no objection to having Slirp code in QEMU be licensed under the 3-clause BSD license. Thanks for taking the effort to consult me about this. Dan ... Kelly Price: Date: Thu, 8 Jan 2009 19:38:56 -0500 From: "Kelly Price" <strredwolf@gmail.com> To: "Richard Fontana" <rfontana@redhat.com> Subject: Re: Slirp license Thanks for contacting me, Richard. I'm glad you were able to find Dan, as I've been "keeping the light on" for Slirp. I have no use for it now, and I have little time for it (now holding onto Keenspot's Comic Genesis and having a regular US state government position). If Dan would like to return to the project, I'd love to give it back to him. As for copyright, I don't own all of it. Dan does, so I will defer to him. Any of my patches I will gladly license to the 3-part BSD license. My interest in re-licensing was because we didn't have ready info to contact Dan. If Dan would like to port Slirp back out of QEMU, a lot of us 64-bit users would be grateful. Feel free to share this email address with Dan. I will be glad to effect a transfer of the project to him and Mr. Bellard of the QEMU project. Signed-off-by: Anthony Liguori <aliguori@us.ibm.com> git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6451 c046a42c-6fe2-441c-8c8c-71466251a162
2009-01-26 19:37:41 +00:00
* 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.
*
* @(#)ip_input.c 8.2 (Berkeley) 1/4/94
* ip_input.c,v 1.11 1994/11/16 10:17:08 jkh Exp
*/
/*
* Changes and additions relating to SLiRP are
* Copyright (c) 1995 Danny Gasparovski.
*
* Please read the file COPYRIGHT for the
* terms and conditions of the copyright.
*/
#include "qemu/osdep.h"
#include "slirp.h"
#include "ip_icmp.h"
static struct ip *ip_reass(Slirp *slirp, struct ip *ip, struct ipq *fp);
static void ip_freef(Slirp *slirp, struct ipq *fp);
static void ip_enq(register struct ipasfrag *p,
register struct ipasfrag *prev);
static void ip_deq(register struct ipasfrag *p);
/*
* IP initialization: fill in IP protocol switch table.
* All protocols not implemented in kernel go to raw IP protocol handler.
*/
void
ip_init(Slirp *slirp)
{
slirp->ipq.ip_link.next = slirp->ipq.ip_link.prev = &slirp->ipq.ip_link;
udp_init(slirp);
tcp_init(slirp);
icmp_init(slirp);
}
void ip_cleanup(Slirp *slirp)
{
udp_cleanup(slirp);
tcp_cleanup(slirp);
icmp_cleanup(slirp);
}
/*
* Ip input routine. Checksum and byte swap header. If fragmented
* try to reassemble. Process options. Pass to next level.
*/
void
ip_input(struct mbuf *m)
{
Slirp *slirp = m->slirp;
register struct ip *ip;
int hlen;
if (!slirp->in_enabled) {
goto bad;
}
DEBUG_CALL("ip_input");
DEBUG_ARG("m = %p", m);
DEBUG_ARG("m_len = %d", m->m_len);
if (m->m_len < sizeof (struct ip)) {
goto bad;
}
ip = mtod(m, struct ip *);
if (ip->ip_v != IPVERSION) {
goto bad;
}
hlen = ip->ip_hl << 2;
if (hlen<sizeof(struct ip ) || hlen>m->m_len) {/* min header length */
goto bad; /* or packet too short */
}
/* keep ip header intact for ICMP reply
* ip->ip_sum = cksum(m, hlen);
* if (ip->ip_sum) {
*/
if(cksum(m,hlen)) {
goto bad;
}
/*
* Convert fields to host representation.
*/
NTOHS(ip->ip_len);
if (ip->ip_len < hlen) {
goto bad;
}
NTOHS(ip->ip_id);
NTOHS(ip->ip_off);
/*
* Check that the amount of data in the buffers
* is as at least much as the IP header would have us expect.
* Trim mbufs if longer than we expect.
* Drop packet if shorter than we expect.
*/
if (m->m_len < ip->ip_len) {
goto bad;
}
/* Should drop packet if mbuf too long? hmmm... */
if (m->m_len > ip->ip_len)
m_adj(m, ip->ip_len - m->m_len);
/* check ip_ttl for a correct ICMP reply */
if (ip->ip_ttl == 0) {
icmp_send_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, 0, "ttl");
goto bad;
}
/*
* If offset or IP_MF are set, must reassemble.
* Otherwise, nothing need be done.
* (We could look in the reassembly queue to see
* if the packet was previously fragmented,
* but it's not worth the time; just let them time out.)
*
* XXX This should fail, don't fragment yet
*/
if (ip->ip_off &~ IP_DF) {
register struct ipq *fp;
struct qlink *l;
/*
* Look for queue of fragments
* of this datagram.
*/
for (l = slirp->ipq.ip_link.next; l != &slirp->ipq.ip_link;
l = l->next) {
fp = container_of(l, struct ipq, ip_link);
if (ip->ip_id == fp->ipq_id &&
ip->ip_src.s_addr == fp->ipq_src.s_addr &&
ip->ip_dst.s_addr == fp->ipq_dst.s_addr &&
ip->ip_p == fp->ipq_p)
goto found;
}
fp = NULL;
found:
/*
* Adjust ip_len to not reflect header,
* set ip_mff if more fragments are expected,
* convert offset of this to bytes.
*/
ip->ip_len -= hlen;
if (ip->ip_off & IP_MF)
ip->ip_tos |= 1;
else
ip->ip_tos &= ~1;
ip->ip_off <<= 3;
/*
* If datagram marked as having more fragments
* or if this is not the first fragment,
* attempt reassembly; if it succeeds, proceed.
*/
if (ip->ip_tos & 1 || ip->ip_off) {
ip = ip_reass(slirp, ip, fp);
if (ip == NULL)
return;
m = dtom(slirp, ip);
} else
if (fp)
ip_freef(slirp, fp);
} else
ip->ip_len -= hlen;
/*
* Switch out to protocol's input routine.
*/
switch (ip->ip_p) {
case IPPROTO_TCP:
tcp_input(m, hlen, (struct socket *)NULL, AF_INET);
break;
case IPPROTO_UDP:
udp_input(m, hlen);
break;
case IPPROTO_ICMP:
icmp_input(m, hlen);
break;
default:
m_free(m);
}
return;
bad:
m_free(m);
}
#define iptofrag(P) ((struct ipasfrag *)(((char*)(P)) - sizeof(struct qlink)))
#define fragtoip(P) ((struct ip*)(((char*)(P)) + sizeof(struct qlink)))
/*
* Take incoming datagram fragment and try to
* reassemble it into whole datagram. If a chain for
* reassembly of this datagram already exists, then it
* is given as fp; otherwise have to make a chain.
*/
static struct ip *
ip_reass(Slirp *slirp, struct ip *ip, struct ipq *fp)
{
register struct mbuf *m = dtom(slirp, ip);
register struct ipasfrag *q;
int hlen = ip->ip_hl << 2;
int i, next;
DEBUG_CALL("ip_reass");
DEBUG_ARG("ip = %p", ip);
DEBUG_ARG("fp = %p", fp);
DEBUG_ARG("m = %p", m);
/*
* Presence of header sizes in mbufs
* would confuse code below.
* Fragment m_data is concatenated.
*/
m->m_data += hlen;
m->m_len -= hlen;
/*
* If first fragment to arrive, create a reassembly queue.
*/
if (fp == NULL) {
struct mbuf *t = m_get(slirp);
if (t == NULL) {
goto dropfrag;
}
fp = mtod(t, struct ipq *);
insque(&fp->ip_link, &slirp->ipq.ip_link);
fp->ipq_ttl = IPFRAGTTL;
fp->ipq_p = ip->ip_p;
fp->ipq_id = ip->ip_id;
fp->frag_link.next = fp->frag_link.prev = &fp->frag_link;
fp->ipq_src = ip->ip_src;
fp->ipq_dst = ip->ip_dst;
q = (struct ipasfrag *)fp;
goto insert;
}
/*
* Find a segment which begins after this one does.
*/
for (q = fp->frag_link.next; q != (struct ipasfrag *)&fp->frag_link;
q = q->ipf_next)
if (q->ipf_off > ip->ip_off)
break;
/*
* If there is a preceding segment, it may provide some of
* our data already. If so, drop the data from the incoming
* segment. If it provides all of our data, drop us.
*/
if (q->ipf_prev != &fp->frag_link) {
struct ipasfrag *pq = q->ipf_prev;
i = pq->ipf_off + pq->ipf_len - ip->ip_off;
if (i > 0) {
if (i >= ip->ip_len)
goto dropfrag;
m_adj(dtom(slirp, ip), i);
ip->ip_off += i;
ip->ip_len -= i;
}
}
/*
* While we overlap succeeding segments trim them or,
* if they are completely covered, dequeue them.
*/
while (q != (struct ipasfrag*)&fp->frag_link &&
ip->ip_off + ip->ip_len > q->ipf_off) {
i = (ip->ip_off + ip->ip_len) - q->ipf_off;
if (i < q->ipf_len) {
q->ipf_len -= i;
q->ipf_off += i;
m_adj(dtom(slirp, q), i);
break;
}
q = q->ipf_next;
m_free(dtom(slirp, q->ipf_prev));
ip_deq(q->ipf_prev);
}
insert:
/*
* Stick new segment in its place;
* check for complete reassembly.
*/
ip_enq(iptofrag(ip), q->ipf_prev);
next = 0;
for (q = fp->frag_link.next; q != (struct ipasfrag*)&fp->frag_link;
q = q->ipf_next) {
if (q->ipf_off != next)
return NULL;
next += q->ipf_len;
}
if (((struct ipasfrag *)(q->ipf_prev))->ipf_tos & 1)
return NULL;
/*
* Reassembly is complete; concatenate fragments.
*/
q = fp->frag_link.next;
m = dtom(slirp, q);
q = (struct ipasfrag *) q->ipf_next;
while (q != (struct ipasfrag*)&fp->frag_link) {
struct mbuf *t = dtom(slirp, q);
q = (struct ipasfrag *) q->ipf_next;
m_cat(m, t);
}
/*
* Create header for new ip packet by
* modifying header of first packet;
* dequeue and discard fragment reassembly header.
* Make header visible.
*/
q = fp->frag_link.next;
/*
* If the fragments concatenated to an mbuf that's
* bigger than the total size of the fragment, then and
* m_ext buffer was alloced. But fp->ipq_next points to
* the old buffer (in the mbuf), so we must point ip
* into the new buffer.
*/
if (m->m_flags & M_EXT) {
int delta = (char *)q - m->m_dat;
q = (struct ipasfrag *)(m->m_ext + delta);
}
ip = fragtoip(q);
ip->ip_len = next;
ip->ip_tos &= ~1;
ip->ip_src = fp->ipq_src;
ip->ip_dst = fp->ipq_dst;
remque(&fp->ip_link);
(void) m_free(dtom(slirp, fp));
m->m_len += (ip->ip_hl << 2);
m->m_data -= (ip->ip_hl << 2);
return ip;
dropfrag:
m_free(m);
return NULL;
}
/*
* Free a fragment reassembly header and all
* associated datagrams.
*/
static void
ip_freef(Slirp *slirp, struct ipq *fp)
{
register struct ipasfrag *q, *p;
for (q = fp->frag_link.next; q != (struct ipasfrag*)&fp->frag_link; q = p) {
p = q->ipf_next;
ip_deq(q);
m_free(dtom(slirp, q));
}
remque(&fp->ip_link);
(void) m_free(dtom(slirp, fp));
}
/*
* Put an ip fragment on a reassembly chain.
* Like insque, but pointers in middle of structure.
*/
static void
ip_enq(register struct ipasfrag *p, register struct ipasfrag *prev)
{
DEBUG_CALL("ip_enq");
DEBUG_ARG("prev = %p", prev);
p->ipf_prev = prev;
p->ipf_next = prev->ipf_next;
((struct ipasfrag *)(prev->ipf_next))->ipf_prev = p;
prev->ipf_next = p;
}
/*
* To ip_enq as remque is to insque.
*/
static void
ip_deq(register struct ipasfrag *p)
{
((struct ipasfrag *)(p->ipf_prev))->ipf_next = p->ipf_next;
((struct ipasfrag *)(p->ipf_next))->ipf_prev = p->ipf_prev;
}
/*
* IP timer processing;
* if a timer expires on a reassembly
* queue, discard it.
*/
void
ip_slowtimo(Slirp *slirp)
{
struct qlink *l;
DEBUG_CALL("ip_slowtimo");
l = slirp->ipq.ip_link.next;
if (l == NULL)
return;
while (l != &slirp->ipq.ip_link) {
struct ipq *fp = container_of(l, struct ipq, ip_link);
l = l->next;
if (--fp->ipq_ttl == 0) {
ip_freef(slirp, fp);
}
}
}
/*
* Do option processing on a datagram,
* possibly discarding it if bad options are encountered,
* or forwarding it if source-routed.
* Returns 1 if packet has been forwarded/freed,
* 0 if the packet should be processed further.
*/
#ifdef notdef
int
ip_dooptions(m)
struct mbuf *m;
{
register struct ip *ip = mtod(m, struct ip *);
register u_char *cp;
register struct ip_timestamp *ipt;
register struct in_ifaddr *ia;
int opt, optlen, cnt, off, code, type, forward = 0;
struct in_addr *sin, dst;
typedef uint32_t n_time;
n_time ntime;
dst = ip->ip_dst;
cp = (u_char *)(ip + 1);
cnt = (ip->ip_hl << 2) - sizeof (struct ip);
for (; cnt > 0; cnt -= optlen, cp += optlen) {
opt = cp[IPOPT_OPTVAL];
if (opt == IPOPT_EOL)
break;
if (opt == IPOPT_NOP)
optlen = 1;
else {
optlen = cp[IPOPT_OLEN];
if (optlen <= 0 || optlen > cnt) {
code = &cp[IPOPT_OLEN] - (u_char *)ip;
goto bad;
}
}
switch (opt) {
default:
break;
/*
* Source routing with record.
* Find interface with current destination address.
* If none on this machine then drop if strictly routed,
* or do nothing if loosely routed.
* Record interface address and bring up next address
* component. If strictly routed make sure next
* address is on directly accessible net.
*/
case IPOPT_LSRR:
case IPOPT_SSRR:
if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
code = &cp[IPOPT_OFFSET] - (u_char *)ip;
goto bad;
}
ipaddr.sin_addr = ip->ip_dst;
ia = (struct in_ifaddr *)
ifa_ifwithaddr((struct sockaddr *)&ipaddr);
if (ia == 0) {
if (opt == IPOPT_SSRR) {
type = ICMP_UNREACH;
code = ICMP_UNREACH_SRCFAIL;
goto bad;
}
/*
* Loose routing, and not at next destination
* yet; nothing to do except forward.
*/
break;
}
off--; /* 0 origin */
if (off > optlen - sizeof(struct in_addr)) {
/*
* End of source route. Should be for us.
*/
save_rte(cp, ip->ip_src);
break;
}
/*
* locate outgoing interface
*/
bcopy((caddr_t)(cp + off), (caddr_t)&ipaddr.sin_addr,
sizeof(ipaddr.sin_addr));
if (opt == IPOPT_SSRR) {
#define INA struct in_ifaddr *
#define SA struct sockaddr *
if ((ia = (INA)ifa_ifwithdstaddr((SA)&ipaddr)) == 0)
ia = (INA)ifa_ifwithnet((SA)&ipaddr);
} else
ia = ip_rtaddr(ipaddr.sin_addr);
if (ia == 0) {
type = ICMP_UNREACH;
code = ICMP_UNREACH_SRCFAIL;
goto bad;
}
ip->ip_dst = ipaddr.sin_addr;
bcopy((caddr_t)&(IA_SIN(ia)->sin_addr),
(caddr_t)(cp + off), sizeof(struct in_addr));
cp[IPOPT_OFFSET] += sizeof(struct in_addr);
/*
* Let ip_intr's mcast routing check handle mcast pkts
*/
forward = !IN_MULTICAST(ntohl(ip->ip_dst.s_addr));
break;
case IPOPT_RR:
if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
code = &cp[IPOPT_OFFSET] - (u_char *)ip;
goto bad;
}
/*
* If no space remains, ignore.
*/
off--; /* 0 origin */
if (off > optlen - sizeof(struct in_addr))
break;
bcopy((caddr_t)(&ip->ip_dst), (caddr_t)&ipaddr.sin_addr,
sizeof(ipaddr.sin_addr));
/*
* locate outgoing interface; if we're the destination,
* use the incoming interface (should be same).
*/
if ((ia = (INA)ifa_ifwithaddr((SA)&ipaddr)) == 0 &&
(ia = ip_rtaddr(ipaddr.sin_addr)) == 0) {
type = ICMP_UNREACH;
code = ICMP_UNREACH_HOST;
goto bad;
}
bcopy((caddr_t)&(IA_SIN(ia)->sin_addr),
(caddr_t)(cp + off), sizeof(struct in_addr));
cp[IPOPT_OFFSET] += sizeof(struct in_addr);
break;
case IPOPT_TS:
code = cp - (u_char *)ip;
ipt = (struct ip_timestamp *)cp;
if (ipt->ipt_len < 5)
goto bad;
if (ipt->ipt_ptr > ipt->ipt_len - sizeof (int32_t)) {
if (++ipt->ipt_oflw == 0)
goto bad;
break;
}
sin = (struct in_addr *)(cp + ipt->ipt_ptr - 1);
switch (ipt->ipt_flg) {
case IPOPT_TS_TSONLY:
break;
case IPOPT_TS_TSANDADDR:
if (ipt->ipt_ptr + sizeof(n_time) +
sizeof(struct in_addr) > ipt->ipt_len)
goto bad;
ipaddr.sin_addr = dst;
ia = (INA)ifaof_ i f p foraddr((SA)&ipaddr,
m->m_pkthdr.rcvif);
if (ia == 0)
continue;
bcopy((caddr_t)&IA_SIN(ia)->sin_addr,
(caddr_t)sin, sizeof(struct in_addr));
ipt->ipt_ptr += sizeof(struct in_addr);
break;
case IPOPT_TS_PRESPEC:
if (ipt->ipt_ptr + sizeof(n_time) +
sizeof(struct in_addr) > ipt->ipt_len)
goto bad;
bcopy((caddr_t)sin, (caddr_t)&ipaddr.sin_addr,
sizeof(struct in_addr));
if (ifa_ifwithaddr((SA)&ipaddr) == 0)
continue;
ipt->ipt_ptr += sizeof(struct in_addr);
break;
default:
goto bad;
}
ntime = iptime();
bcopy((caddr_t)&ntime, (caddr_t)cp + ipt->ipt_ptr - 1,
sizeof(n_time));
ipt->ipt_ptr += sizeof(n_time);
}
}
if (forward) {
ip_forward(m, 1);
return (1);
}
return (0);
bad:
icmp_send_error(m, type, code, 0, 0);
return (1);
}
#endif /* notdef */
/*
* Strip out IP options, at higher
* level protocol in the kernel.
* Second argument is buffer to which options
* will be moved, and return value is their length.
* (XXX) should be deleted; last arg currently ignored.
*/
void
ip_stripoptions(register struct mbuf *m, struct mbuf *mopt)
{
register int i;
struct ip *ip = mtod(m, struct ip *);
register caddr_t opts;
int olen;
olen = (ip->ip_hl<<2) - sizeof (struct ip);
opts = (caddr_t)(ip + 1);
i = m->m_len - (sizeof (struct ip) + olen);
memcpy(opts, opts + olen, (unsigned)i);
m->m_len -= olen;
ip->ip_hl = sizeof(struct ip) >> 2;
}