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/* SPDX-License-Identifier: BSD-3-Clause */
/*
* Copyright (c) 1982, 1986, 1988, 1990, 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.
*
* @(#)udp_usrreq.c 8.4 (Berkeley) 1/21/94
* udp_usrreq.c,v 1.4 1994/10/02 17:48:45 phk Exp
*/
/*
* Changes and additions relating to SLiRP
* Copyright (c) 1995 Danny Gasparovski.
*
* Please read the file COPYRIGHT for the
* terms and conditions of the copyright.
*/
#include "slirp.h"
#include "ip_icmp.h"
static uint8_t udp_tos(struct socket *so);
void udp_init(Slirp *slirp)
{
slirp->udb.so_next = slirp->udb.so_prev = &slirp->udb;
slirp->udp_last_so = &slirp->udb;
}
void udp_cleanup(Slirp *slirp)
{
struct socket *so, *so_next;
for (so = slirp->udb.so_next; so != &slirp->udb; so = so_next) {
so_next = so->so_next;
udp_detach(slirp->udb.so_next);
}
}
/* m->m_data points at ip packet header
* m->m_len length ip packet
* ip->ip_len length data (IPDU)
*/
void udp_input(register struct mbuf *m, int iphlen)
{
Slirp *slirp = m->slirp;
M_DUP_DEBUG(slirp, m, 0, 0);
register struct ip *ip;
register struct udphdr *uh;
int len;
struct ip save_ip;
struct socket *so;
struct sockaddr_storage lhost;
struct sockaddr_in *lhost4;
int ttl;
DEBUG_CALL("udp_input");
DEBUG_ARG("m = %p", m);
DEBUG_ARG("iphlen = %d", iphlen);
/*
* Strip IP options, if any; should skip this,
* make available to user, and use on returned packets,
* but we don't yet have a way to check the checksum
* with options still present.
*/
if (iphlen > sizeof(struct ip)) {
ip_stripoptions(m, (struct mbuf *)0);
iphlen = sizeof(struct ip);
}
/*
* Get IP and UDP header together in first mbuf.
*/
ip = mtod(m, struct ip *);
uh = (struct udphdr *)((char *)ip + iphlen);
/*
* Make mbuf data length reflect UDP length.
* If not enough data to reflect UDP length, drop.
*/
len = ntohs((uint16_t)uh->uh_ulen);
if (ip->ip_len != len) {
if (len > ip->ip_len) {
goto bad;
}
m_adj(m, len - ip->ip_len);
ip->ip_len = len;
}
/*
* Save a copy of the IP header in case we want restore it
* for sending an ICMP error message in response.
*/
save_ip = *ip;
save_ip.ip_len += iphlen; /* tcp_input subtracts this */
/*
* Checksum extended UDP header and data.
*/
if (uh->uh_sum) {
memset(&((struct ipovly *)ip)->ih_mbuf, 0, sizeof(struct mbuf_ptr));
((struct ipovly *)ip)->ih_x1 = 0;
((struct ipovly *)ip)->ih_len = uh->uh_ulen;
if (cksum(m, len + sizeof(struct ip))) {
goto bad;
}
}
lhost.ss_family = AF_INET;
lhost4 = (struct sockaddr_in *)&lhost;
lhost4->sin_addr = ip->ip_src;
lhost4->sin_port = uh->uh_sport;
/*
* handle DHCP/BOOTP
*/
if (ntohs(uh->uh_dport) == BOOTP_SERVER &&
(ip->ip_dst.s_addr == slirp->vhost_addr.s_addr ||
ip->ip_dst.s_addr == 0xffffffff)) {
bootp_input(m);
goto bad;
}
/*
* handle TFTP
*/
if (ntohs(uh->uh_dport) == TFTP_SERVER &&
ip->ip_dst.s_addr == slirp->vhost_addr.s_addr) {
m->m_data += iphlen;
m->m_len -= iphlen;
tftp_input(&lhost, m);
m->m_data -= iphlen;
m->m_len += iphlen;
goto bad;
}
if (slirp->restricted) {
goto bad;
}
/*
* Locate pcb for datagram.
*/
so = solookup(&slirp->udp_last_so, &slirp->udb, &lhost, NULL);
if (so == NULL) {
/*
* If there's no socket for this packet,
* create one
*/
so = socreate(slirp);
if (udp_attach(so, AF_INET) == -1) {
DEBUG_MISC(" udp_attach errno = %d-%s", errno, strerror(errno));
sofree(so);
goto bad;
}
/*
* Setup fields
*/
so->so_lfamily = AF_INET;
so->so_laddr = ip->ip_src;
so->so_lport = uh->uh_sport;
if ((so->so_iptos = udp_tos(so)) == 0)
so->so_iptos = ip->ip_tos;
/*
* XXXXX Here, check if it's in udpexec_list,
* and if it is, do the fork_exec() etc.
*/
}
so->so_ffamily = AF_INET;
so->so_faddr = ip->ip_dst; /* XXX */
so->so_fport = uh->uh_dport; /* XXX */
iphlen += sizeof(struct udphdr);
m->m_len -= iphlen;
m->m_data += iphlen;
/*
* Check for TTL
*/
ttl = save_ip.ip_ttl-1;
if (ttl <= 0) {
m->m_len += iphlen;
m->m_data -= iphlen;
*ip = save_ip;
DEBUG_MISC("udp ttl exceeded");
icmp_send_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, 0, NULL);
goto bad;
}
setsockopt(so->s, IPPROTO_IP, IP_TTL, &ttl, sizeof(ttl));
/*
* Now we sendto() the packet.
*/
if (sosendto(so, m) == -1) {
m->m_len += iphlen;
m->m_data -= iphlen;
*ip = save_ip;
DEBUG_MISC("udp tx errno = %d-%s", errno, strerror(errno));
icmp_send_error(m, ICMP_UNREACH, ICMP_UNREACH_NET, 0, strerror(errno));
goto bad;
}
m_free(so->so_m); /* used for ICMP if error on sorecvfrom */
/* restore the orig mbuf packet */
m->m_len += iphlen;
m->m_data -= iphlen;
*ip = save_ip;
so->so_m = m; /* ICMP backup */
return;
bad:
m_free(m);
}
int udp_output(struct socket *so, struct mbuf *m, struct sockaddr_in *saddr,
struct sockaddr_in *daddr, int iptos)
{
Slirp *slirp = m->slirp;
M_DUP_DEBUG(slirp, m, 0, sizeof(struct udpiphdr));
register struct udpiphdr *ui;
int error = 0;
DEBUG_CALL("udp_output");
DEBUG_ARG("so = %p", so);
DEBUG_ARG("m = %p", m);
DEBUG_ARG("saddr = %s", inet_ntoa(saddr->sin_addr));
DEBUG_ARG("daddr = %s", inet_ntoa(daddr->sin_addr));
/*
* Adjust for header
*/
m->m_data -= sizeof(struct udpiphdr);
m->m_len += sizeof(struct udpiphdr);
/*
* Fill in mbuf with extended UDP header
* and addresses and length put into network format.
*/
ui = mtod(m, struct udpiphdr *);
memset(&ui->ui_i.ih_mbuf, 0, sizeof(struct mbuf_ptr));
ui->ui_x1 = 0;
ui->ui_pr = IPPROTO_UDP;
ui->ui_len = htons(m->m_len - sizeof(struct ip));
/* XXXXX Check for from-one-location sockets, or from-any-location sockets
*/
ui->ui_src = saddr->sin_addr;
ui->ui_dst = daddr->sin_addr;
ui->ui_sport = saddr->sin_port;
ui->ui_dport = daddr->sin_port;
ui->ui_ulen = ui->ui_len;
/*
* Stuff checksum and output datagram.
*/
ui->ui_sum = 0;
if ((ui->ui_sum = cksum(m, m->m_len)) == 0)
ui->ui_sum = 0xffff;
((struct ip *)ui)->ip_len = m->m_len;
((struct ip *)ui)->ip_ttl = IPDEFTTL;
((struct ip *)ui)->ip_tos = iptos;
error = ip_output(so, m);
return (error);
}
int udp_attach(struct socket *so, unsigned short af)
{
so->s = slirp_socket(af, SOCK_DGRAM, 0);
if (so->s != -1) {
if (slirp_bind_outbound(so, af) != 0) {
// bind failed - close socket
closesocket(so->s);
so->s = -1;
return -1;
}
#ifdef __linux__
{
int opt = 1;
switch (af) {
case AF_INET:
setsockopt(so->s, IPPROTO_IP, IP_RECVERR, &opt, sizeof(opt));
break;
case AF_INET6:
setsockopt(so->s, IPPROTO_IPV6, IPV6_RECVERR, &opt, sizeof(opt));
break;
default:
g_assert_not_reached();
}
}
#endif
so->so_expire = curtime + SO_EXPIRE;
insque(so, &so->slirp->udb);
}
so->slirp->cb->register_poll_fd(so->s, so->slirp->opaque);
return (so->s);
}
void udp_detach(struct socket *so)
{
so->slirp->cb->unregister_poll_fd(so->s, so->slirp->opaque);
closesocket(so->s);
sofree(so);
}
static const struct tos_t udptos[] = { { 0, 53, IPTOS_LOWDELAY, 0 }, /* DNS */
{ 0, 0, 0, 0 } };
static uint8_t udp_tos(struct socket *so)
{
int i = 0;
while (udptos[i].tos) {
if ((udptos[i].fport && ntohs(so->so_fport) == udptos[i].fport) ||
(udptos[i].lport && ntohs(so->so_lport) == udptos[i].lport)) {
if (so->slirp->enable_emu)
so->so_emu = udptos[i].emu;
return udptos[i].tos;
}
i++;
}
return 0;
}
struct socket *udpx_listen(Slirp *slirp,
const struct sockaddr *haddr, socklen_t haddrlen,
const struct sockaddr *laddr, socklen_t laddrlen,
int flags)
{
struct socket *so;
socklen_t addrlen;
int save_errno;
so = socreate(slirp);
so->s = slirp_socket(haddr->sa_family, SOCK_DGRAM, 0);
if (so->s < 0) {
save_errno = errno;
sofree(so);
errno = save_errno;
return NULL;
}
if (haddr->sa_family == AF_INET6)
slirp_socket_set_v6only(so->s, (flags & SS_HOSTFWD_V6ONLY) != 0);
so->so_expire = curtime + SO_EXPIRE;
insque(so, &slirp->udb);
if (bind(so->s, haddr, haddrlen) < 0) {
save_errno = errno;
udp_detach(so);
errno = save_errno;
return NULL;
}
slirp_socket_set_fast_reuse(so->s);
addrlen = sizeof(so->fhost);
getsockname(so->s, &so->fhost.sa, &addrlen);
sotranslate_accept(so);
sockaddr_copy(&so->lhost.sa, sizeof(so->lhost), laddr, laddrlen);
if (flags != SS_FACCEPTONCE)
so->so_expire = 0;
so->so_state &= SS_PERSISTENT_MASK;
so->so_state |= SS_ISFCONNECTED | flags;
return so;
}
struct socket *udp_listen(Slirp *slirp, uint32_t haddr, unsigned hport,
uint32_t laddr, unsigned lport, int flags)
{
struct sockaddr_in hsa, lsa;
memset(&hsa, 0, sizeof(hsa));
hsa.sin_family = AF_INET;
hsa.sin_addr.s_addr = haddr;
hsa.sin_port = hport;
memset(&lsa, 0, sizeof(lsa));
lsa.sin_family = AF_INET;
lsa.sin_addr.s_addr = laddr;
lsa.sin_port = lport;
return udpx_listen(slirp, (const struct sockaddr *) &hsa, sizeof(hsa), (struct sockaddr *) &lsa, sizeof(lsa), flags);
}
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