udp.c revision 6e0b1e7dbe7efb01d4f11ccbb2bc88ba22b38413
/*
* 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. 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.
* 4. 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"
#include "ctl.h"
/*
* UDP protocol implementation.
* Per RFC 768, August, 1980.
*/
#define udpcksum 1
void
udp_init(PNATState pData)
{
udp_last_so = &udb;
udb.so_next = udb.so_prev = &udb;
}
/* m->m_data points at ip packet header
* m->m_len length ip packet
* ip->ip_len length data (IPDU)
*/
void
udp_input(PNATState pData, register struct mbuf *m, int iphlen)
{
register struct ip *ip;
register struct udphdr *uh;
int len;
struct ip save_ip;
struct socket *so;
int ret;
int ttl;
DEBUG_CALL("udp_input");
DEBUG_ARG("m = %lx", (long)m);
ip = mtod(m, struct ip *);
DEBUG_ARG("iphlen = %d", iphlen);
Log2(("%R[IP4] iphlen = %d\n", &ip->ip_dst, iphlen));
udpstat.udps_ipackets++;
/*
* 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 *)((caddr_t)ip + iphlen);
/*
* Make mbuf data length reflect UDP length.
* If not enough data to reflect UDP length, drop.
*/
len = RT_N2H_U16((u_int16_t)uh->uh_ulen);
Assert((ip->ip_len == len));
Assert((ip->ip_len + iphlen == m->m_len));
if (ip->ip_len != len)
{
if (len > ip->ip_len)
{
udpstat.udps_badlen++;
Log3(("NAT: IP(id: %hd) has bad size\n", ip->ip_id));
}
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 (udpcksum && uh->uh_sum)
{
memset(((struct ipovly *)ip)->ih_x1, 0, 9);
((struct ipovly *)ip)->ih_len = uh->uh_ulen;
#if 0
/* keep uh_sum for ICMP reply */
uh->uh_sum = cksum(m, len + sizeof (struct ip));
if (uh->uh_sum)
{
#endif
if(cksum(m, len + iphlen))
{
udpstat.udps_badsum++;
Log3(("NAT: IP(id: %hd) has bad (udp) cksum\n", ip->ip_id));
goto bad;
}
}
#if 0
}
#endif
/*
* handle DHCP/BOOTP
*/
if (uh->uh_dport == RT_H2N_U16_C(BOOTP_SERVER))
{
bootp_input(pData, m);
goto done;
}
if ( pData->fUseHostResolver
&& uh->uh_dport == RT_H2N_U16_C(53)
&& CTL_CHECK(RT_N2H_U32(ip->ip_dst.s_addr), CTL_DNS))
{
struct sockaddr_in dst, src;
src.sin_addr.s_addr = ip->ip_dst.s_addr;
src.sin_port = uh->uh_dport;
dst.sin_addr.s_addr = ip->ip_src.s_addr;
dst.sin_port = uh->uh_sport;
/* udp_output2 will do opposite operations on mbuf*/
m->m_data += sizeof(struct udpiphdr);
m->m_len -= sizeof(struct udpiphdr);
udp_output2(pData, NULL, m, &src, &dst, IPTOS_LOWDELAY);
goto done;
}
/*
* handle TFTP
*/
if ( uh->uh_dport == RT_H2N_U16_C(TFTP_SERVER)
&& CTL_CHECK(RT_N2H_U32(ip->ip_dst.s_addr), CTL_TFTP))
{
tftp_input(pData, m);
goto done;
}
/*
* Locate pcb for datagram.
*/
so = udp_last_so;
if ( so->so_lport != uh->uh_sport
|| so->so_laddr.s_addr != ip->ip_src.s_addr)
{
struct socket *tmp;
for (tmp = udb.so_next; tmp != &udb; tmp = tmp->so_next)
{
if ( tmp->so_lport == uh->uh_sport
&& tmp->so_laddr.s_addr == ip->ip_src.s_addr)
{
so = tmp;
break;
}
}
if (tmp == &udb)
so = NULL;
else
{
udpstat.udpps_pcbcachemiss++;
udp_last_so = so;
}
}
if (so == NULL)
{
/*
* If there's no socket for this packet,
* create one
*/
if ((so = socreate()) == NULL)
{
Log3(("NAT: IP(id: %hd) failed to create socket\n", ip->ip_id));
goto bad;
}
if (udp_attach(pData, so, 0) == -1)
{
Log3(("NAT: IP(id: %hd) udp_attach errno = %d-%s\n",
ip->ip_id, errno, strerror(errno)));
sofree(pData, so);
goto bad;
}
/*
* Setup fields
*/
/* udp_last_so = so; */
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_faddr = ip->ip_dst; /* XXX */
so->so_fport = uh->uh_dport; /* XXX */
/*
* DNS proxy
*/
if ( pData->fUseDnsProxy
&& (ip->ip_dst.s_addr == RT_H2N_U32(RT_N2H_U32(pData->special_addr.s_addr) | CTL_DNS))
&& (uh->uh_dport == RT_H2N_U16_C(53)))
{
dnsproxy_query(pData, so, m, iphlen);
goto done;
}
iphlen += sizeof(struct udphdr);
m->m_len -= iphlen;
m->m_data += iphlen;
/*
* Now we sendto() the packet.
*/
if (so->so_emu)
udp_emu(pData, so, m);
ttl = ip->ip_ttl = save_ip.ip_ttl;
ret = setsockopt(so->s, IPPROTO_IP, IP_TTL, (const char*)&ttl, sizeof(ttl));
if (ret < 0)
LogRel(("NAT: Error (%s) occurred while setting TTL(%d) attribute "
"of IP packet to socket %R[natsock]\n", strerror(errno), ip->ip_ttl, so));
if (sosendto(pData, so, m) == -1)
{
m->m_len += iphlen;
m->m_data -= iphlen;
*ip = save_ip;
DEBUG_MISC((dfd,"NAT: UDP tx errno = %d-%s (on sent to %R[IP4])\n", errno,
strerror(errno), &ip->ip_dst));
icmp_error(pData, m, ICMP_UNREACH, ICMP_UNREACH_NET, 0, strerror(errno));
/* in case we receive ICMP on this socket we'll aware that ICMP has been already sent to host*/
so->so_m = NULL;
}
if (so->so_m)
m_free(pData, 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:
Log2(("NAT: UDP(id: %hd) datagram to %R[IP4] with size(%d) claimed as bad\n",
ip->ip_id, &ip->ip_dst, ip->ip_len));
done:
/* some services like bootp(built-in), dns(buildt-in) and dhcp don't need sockets
* and create new m'buffers to send them to guest, so we'll free their incomming
* buffers here.
*/
m_freem(pData, m);
return;
}
int udp_output2(PNATState pData, struct socket *so, struct mbuf *m,
struct sockaddr_in *saddr, struct sockaddr_in *daddr,
int iptos)
{
register struct udpiphdr *ui;
int error = 0;
DEBUG_CALL("udp_output");
DEBUG_ARG("so = %lx", (long)so);
DEBUG_ARG("m = %lx", (long)m);
DEBUG_ARG("saddr = %lx", (long)saddr->sin_addr.s_addr);
DEBUG_ARG("daddr = %lx", (long)daddr->sin_addr.s_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_x1, 0, 9);
ui->ui_pr = IPPROTO_UDP;
ui->ui_len = RT_H2N_U16(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 (udpcksum)
{
if ((ui->ui_sum = cksum(m, /* sizeof (struct udpiphdr) + */ m->m_len)) == 0)
ui->ui_sum = 0xffff;
}
((struct ip *)ui)->ip_len = m->m_len;
((struct ip *)ui)->ip_ttl = ip_defttl;
((struct ip *)ui)->ip_tos = iptos;
udpstat.udps_opackets++;
error = ip_output(pData, so, m);
return error;
}
int udp_output(PNATState pData, struct socket *so, struct mbuf *m,
struct sockaddr_in *addr)
{
struct sockaddr_in saddr, daddr;
saddr = *addr;
if ((so->so_faddr.s_addr & RT_H2N_U32(pData->netmask)) == pData->special_addr.s_addr)
{
saddr.sin_addr.s_addr = so->so_faddr.s_addr;
if ((so->so_faddr.s_addr & RT_H2N_U32(~pData->netmask)) == RT_H2N_U32(~pData->netmask))
saddr.sin_addr.s_addr = alias_addr.s_addr;
}
/* Any UDP packet to the loopback address must be translated to be from
* the forwarding address, i.e. 10.0.2.2. */
if ( (saddr.sin_addr.s_addr & RT_H2N_U32_C(IN_CLASSA_NET))
== RT_H2N_U32_C(INADDR_LOOPBACK & IN_CLASSA_NET))
saddr.sin_addr.s_addr = alias_addr.s_addr;
daddr.sin_addr = so->so_laddr;
daddr.sin_port = so->so_lport;
return udp_output2(pData, so, m, &saddr, &daddr, so->so_iptos);
}
int
udp_attach(PNATState pData, struct socket *so, int service_port)
{
struct sockaddr_in *addr;
struct sockaddr sa_addr;
socklen_t socklen = sizeof(struct sockaddr);
int status;
int opt = 1;
if ((so->s = socket(AF_INET, SOCK_DGRAM, 0)) == -1)
goto error;
/*
* Here, we bind() the socket. Although not really needed
* (sendto() on an unbound socket will bind it), it's done
* here so that emulation of ytalk etc. don't have to do it
*/
memset(&sa_addr, 0, sizeof(struct sockaddr));
addr = (struct sockaddr_in *)&sa_addr;
#ifdef RT_OS_DARWIN
addr->sin_len = sizeof(struct sockaddr_in);
#endif
addr->sin_family = AF_INET;
addr->sin_port = service_port;
addr->sin_addr.s_addr = pData->bindIP.s_addr;
fd_nonblock(so->s);
if (bind(so->s, &sa_addr, sizeof(struct sockaddr_in)) < 0)
{
int lasterrno = errno;
closesocket(so->s);
so->s = -1;
#ifdef RT_OS_WINDOWS
WSASetLastError(lasterrno);
#else
errno = lasterrno;
#endif
goto error;
}
/* success, insert in queue */
so->so_expire = curtime + SO_EXPIRE;
/* enable broadcast for later use */
setsockopt(so->s, SOL_SOCKET, SO_BROADCAST, (const char *)&opt, sizeof(opt));
status = getsockname(so->s, &sa_addr, &socklen);
Assert(status == 0 && sa_addr.sa_family == AF_INET);
so->so_hlport = ((struct sockaddr_in *)&sa_addr)->sin_port;
so->so_hladdr.s_addr = ((struct sockaddr_in *)&sa_addr)->sin_addr.s_addr;
SOCKET_LOCK_CREATE(so);
QSOCKET_LOCK(udb);
insque(pData, so, &udb);
NSOCK_INC();
QSOCKET_UNLOCK(udb);
return so->s;
error:
Log2(("NAT: can't create datagramm socket\n"));
return -1;
}
void
udp_detach(PNATState pData, struct socket *so)
{
if (so != &pData->icmp_socket)
{
QSOCKET_LOCK(udb);
SOCKET_LOCK(so);
QSOCKET_UNLOCK(udb);
closesocket(so->s);
sofree(pData, so);
SOCKET_UNLOCK(so);
}
}
static const struct tos_t udptos[] =
{
{ 0, 53, IPTOS_LOWDELAY, 0 }, /* DNS */
{ 517, 517, IPTOS_LOWDELAY, EMU_TALK }, /* talk */
{ 518, 518, IPTOS_LOWDELAY, EMU_NTALK }, /* ntalk */
{ 0, 7648, IPTOS_LOWDELAY, EMU_CUSEEME }, /* Cu-Seeme */
{ 0, 0, 0, 0 }
};
u_int8_t
udp_tos(struct socket *so)
{
int i = 0;
while(udptos[i].tos)
{
if ( (udptos[i].fport && RT_N2H_U16(so->so_fport) == udptos[i].fport)
|| (udptos[i].lport && RT_N2H_U16(so->so_lport) == udptos[i].lport))
{
so->so_emu = udptos[i].emu;
return udptos[i].tos;
}
i++;
}
return 0;
}
#ifdef EMULATE_TALK
#include "talkd.h"
#endif
/*
* Here, talk/ytalk/ntalk requests must be emulated
*/
void
udp_emu(PNATState pData, struct socket *so, struct mbuf *m)
{
so->so_emu = 0;
}
struct socket *
udp_listen(PNATState pData, u_int32_t bind_addr, u_int port, u_int32_t laddr, u_int lport, int flags)
{
struct sockaddr_in addr;
struct socket *so;
socklen_t addrlen = sizeof(struct sockaddr_in);
int opt = 1;
if ((so = socreate()) == NULL)
return NULL;
so->s = socket(AF_INET, SOCK_DGRAM, 0);
if (so->s == -1)
{
LogRel(("NAT: can't create datagram socket\n"));
RTMemFree(so);
return NULL;
}
so->so_expire = curtime + SO_EXPIRE;
fd_nonblock(so->s);
SOCKET_LOCK_CREATE(so);
QSOCKET_LOCK(udb);
insque(pData, so, &udb);
NSOCK_INC();
QSOCKET_UNLOCK(udb);
memset(&addr, 0, sizeof(addr));
#ifdef RT_OS_DARWIN
addr.sin_len = sizeof(addr);
#endif
addr.sin_family = AF_INET;
addr.sin_addr.s_addr = bind_addr;
addr.sin_port = port;
if (bind(so->s,(struct sockaddr *)&addr, addrlen) < 0)
{
LogRel(("NAT: bind to %R[IP4] has been failed\n", &addr.sin_addr));
udp_detach(pData, so);
return NULL;
}
setsockopt(so->s, SOL_SOCKET, SO_REUSEADDR,(char *)&opt, sizeof(int));
/* setsockopt(so->s, SOL_SOCKET, SO_OOBINLINE,(char *)&opt, sizeof(int)); */
getsockname(so->s,(struct sockaddr *)&addr,&addrlen);
so->so_fport = addr.sin_port;
/* The original check was completely broken, as the commented out
* if statement was always true (INADDR_ANY=0). */
/* if (addr.sin_addr.s_addr == 0 || addr.sin_addr.s_addr == loopback_addr.s_addr) */
if (1 == 0) /* always use the else part */
so->so_faddr = alias_addr;
else
so->so_faddr = addr.sin_addr;
so->so_lport = lport;
so->so_laddr.s_addr = laddr;
if (flags != SS_FACCEPTONCE)
so->so_expire = 0;
so->so_state = SS_ISFCONNECTED;
return so;
}