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/*
* 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;
}
/* 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;
register struct ip *ip;
register struct udphdr *uh;
int len;
struct ip save_ip;
struct socket *so;

DEBUG_CALL("udp_input");
DEBUG_ARG("m = %lx", (long)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 *)((caddr_t)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;
}
}

        /*
* handle DHCP/BOOTP
*/
        if (ntohs(uh->uh_dport) == BOOTP_SERVER) {
            bootp_input(m);
            goto bad;
        }

        if (slirp->restricted) {
            goto bad;
        }

        /*
* handle TFTP
*/
        if (ntohs(uh->uh_dport) == TFTP_SERVER) {
            tftp_input(m);
            goto bad;
        }

/*
* Locate pcb for datagram.
*/
so = slirp->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 = slirp->udb.so_next; tmp != &slirp->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 == &slirp->udb) {
so = NULL;
} else {
slirp->udp_last_so = so;
}
}

if (so == NULL) {
/*
* If there's no socket for this packet,
* create one
*/
so = socreate(slirp);
if (!so) {
goto bad;
}
if(udp_attach(so) == -1) {
DEBUG_MISC((dfd," udp_attach errno = %d-%s\n",
errno,strerror(errno)));
sofree(so);
goto bad;
}

/*
* Setup fields
*/
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 */

iphlen += sizeof(struct udphdr);
m->m_len -= iphlen;
m->m_data += iphlen;

/*
* Now we sendto() the packet.
*/
if(sosendto(so,m) == -1) {
m->m_len += iphlen;
m->m_data -= iphlen;
*ip=save_ip;
DEBUG_MISC((dfd,"udp tx errno = %d-%s\n",errno,strerror(errno)));
icmp_error(m, ICMP_UNREACH,ICMP_UNREACH_NET, 0,strerror(errno));
}

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_freem(m);
return;
}

int udp_output2(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_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_output(struct socket *so, struct mbuf *m,
               struct sockaddr_in *addr)

{
    Slirp *slirp = so->slirp;
    struct sockaddr_in saddr, daddr;

    saddr = *addr;
    if ((so->so_faddr.s_addr & slirp->vnetwork_mask.s_addr) ==
        slirp->vnetwork_addr.s_addr) {
        uint32_t inv_mask = ~slirp->vnetwork_mask.s_addr;

        if ((so->so_faddr.s_addr & inv_mask) == inv_mask) {
            saddr.sin_addr = slirp->vhost_addr;
        } else if (addr->sin_addr.s_addr == loopback_addr.s_addr ||
                   so->so_faddr.s_addr != slirp->vhost_addr.s_addr) {
            saddr.sin_addr = so->so_faddr;
        }
    }
    daddr.sin_addr = so->so_laddr;
    daddr.sin_port = so->so_lport;

    return udp_output2(so, m, &saddr, &daddr, so->so_iptos);
}

int
udp_attach(struct socket *so)
{
  if((so->s = qemu_socket(AF_INET,SOCK_DGRAM,0)) != -1) {
    so->so_expire = curtime + SO_EXPIRE;
    insque(so, &so->slirp->udb);
  }
  return(so->s);
}

void
udp_detach(struct socket *so)
{
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)) {
so->so_emu = udptos[i].emu;
return udptos[i].tos;
}
i++;
}

return 0;
}

struct socket *
udp_listen(Slirp *slirp, uint32_t haddr, u_int hport, uint32_t laddr,
           u_int lport, int flags)
{
struct sockaddr_in addr;
struct socket *so;
socklen_t addrlen = sizeof(struct sockaddr_in), opt = 1;

so = socreate(slirp);
if (!so) {
return NULL;
}
so->s = qemu_socket(AF_INET,SOCK_DGRAM,0);
so->so_expire = curtime + SO_EXPIRE;
insque(so, &slirp->udb);

addr.sin_family = AF_INET;
addr.sin_addr.s_addr = haddr;
addr.sin_port = hport;

if (bind(so->s,(struct sockaddr *)&addr, addrlen) < 0) {
udp_detach(so);
return NULL;
}
setsockopt(so->s,SOL_SOCKET,SO_REUSEADDR,(char *)&opt,sizeof(int));

getsockname(so->s,(struct sockaddr *)&addr,&addrlen);
so->so_fport = addr.sin_port;
if (addr.sin_addr.s_addr == 0 ||
addr.sin_addr.s_addr == loopback_addr.s_addr) {
so->so_faddr = slirp->vhost_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_PERSISTENT_MASK;
so->so_state |= SS_ISFCONNECTED | flags;

return so;
}
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