/*
* 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.
* 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.
*
* $FreeBSD: src/sys/netinet/ip_divert.c,v 1.113 2005/05/13 11:44:37 glebius Exp $
*/
/*
* $Id$
*/
#include <sys/param.h>
#include <rtems/bsd/sys/queue.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/protosw.h>
#include <sys/socketvar.h>
#include <sys/errno.h>
#include <sys/systm.h>
#include <net/if.h>
#include <net/route.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/in_pcb.h>
#include <netinet/in_var.h>
#include <netinet/ip_var.h>
/*
* Divert sockets
*/
/*
* Allocate enough space to hold a full IP packet
*/
#define DIVSNDQ (65536 + 100)
#define DIVRCVQ (65536 + 100)
/* Global variables */
/*
* ip_input() and ip_output() set this secret value before calling us to
* let us know which divert port to divert a packet to; this is done so
* we can use the existing prototype for struct protosw's pr_input().
* This is stored in host order.
*/
u_short ip_divert_port;
/*
* We set this value to a non-zero port number when we want the call to
* ip_fw_chk() in ip_input() or ip_output() to ignore ``divert <port>''
* chain entries. This is stored in host order.
*/
u_short ip_divert_ignore;
/* Internal variables. */
static struct inpcbhead divcb;
static struct inpcbinfo divcbinfo;
static u_long div_sendspace = DIVSNDQ; /* XXX sysctl ? */
static u_long div_recvspace = DIVRCVQ; /* XXX sysctl ? */
/* Optimization: have this preinitialized */
static struct sockaddr_in divsrc = { sizeof(divsrc), AF_INET };
/* Internal functions */
static int div_output(struct socket *so,
struct mbuf *m, struct mbuf *addr, struct mbuf *control);
/*
* Initialize divert connection block queue.
*/
void
div_init(void)
{
LIST_INIT(&divcb);
divcbinfo.listhead = &divcb;
/*
* XXX We don't use the hash list for divert IP, but it's easier
* to allocate a one entry hash list than it is to check all
* over the place for hashbase == NULL.
*/
divcbinfo.hashbase = hashinit(1, M_PCB, &divcbinfo.hashmask);
}
/*
* Setup generic address and protocol structures
* for div_input routine, then pass them along with
* mbuf chain. ip->ip_len is assumed to have had
* the header length (hlen) subtracted out already.
* We tell whether the packet was incoming or outgoing
* by seeing if hlen == 0, which is a hack.
*/
void
div_input(struct mbuf *m, int hlen)
{
struct ip *ip;
struct inpcb *inp;
struct socket *sa;
/* Sanity check */
if (ip_divert_port == 0)
panic("div_input: port is 0");
/* Assure header */
if (m->m_len < sizeof(struct ip) &&
(m = m_pullup(m, sizeof(struct ip))) == 0) {
return;
}
ip = mtod(m, struct ip *);
/* Record divert port */
divsrc.sin_port = htons(ip_divert_port);
/* Restore packet header fields */
ip->ip_len += hlen;
HTONS(ip->ip_len);
HTONS(ip->ip_off);
/* Record receive interface address, if any */
divsrc.sin_addr.s_addr = 0;
if (hlen) {
struct ifaddr *ifa;
#ifdef DIAGNOSTIC
/* Sanity check */
if (!(m->m_flags & M_PKTHDR))
panic("div_input: no pkt hdr");
#endif
/* More fields affected by ip_input() */
HTONS(ip->ip_id);
/* Find IP address for recieve interface */
for (ifa = m->m_pkthdr.rcvif->if_addrlist;
ifa != NULL; ifa = ifa->ifa_next) {
if (ifa->ifa_addr == NULL)
continue;
if (ifa->ifa_addr->sa_family != AF_INET)
continue;
divsrc.sin_addr =
((struct sockaddr_in *) ifa->ifa_addr)->sin_addr;
break;
}
}
/* Put packet on socket queue, if any */
sa = NULL;
for (inp = divcb.lh_first; inp != NULL; inp = inp->inp_list.le_next) {
if (inp->inp_lport == htons(ip_divert_port))
sa = inp->inp_socket;
}
if (sa) {
if (sbappendaddr(&sa->so_rcv, (struct sockaddr *)&divsrc,
m, (struct mbuf *)0) == 0)
m_freem(m);
else
sorwakeup(sa);
} else {
m_freem(m);
ipstat.ips_noproto++;
ipstat.ips_delivered--;
}
}
/*
* Deliver packet back into the IP processing machinery.
*
* If no address specified, or address is 0.0.0.0, send to ip_output();
* otherwise, send to ip_input() and mark as having been received on
* the interface with that address.
*
* If no address specified, or dest port is 0, allow packet to divert
* back to this socket; otherwise, don't.
*/
static int
div_output(struct socket *so, struct mbuf *m,
struct mbuf *addr, struct mbuf *control)
{
register struct inpcb *const inp = sotoinpcb(so);
register struct ip *const ip = mtod(m, struct ip *);
struct sockaddr_in *sin = NULL;
int error = 0;
if (control)
m_freem(control); /* XXX */
if (addr)
sin = mtod(addr, struct sockaddr_in *);
/* Loopback avoidance option */
ip_divert_ignore = ntohs(inp->inp_lport);
/* Reinject packet into the system as incoming or outgoing */
if (!sin || sin->sin_addr.s_addr == 0) {
/* Don't allow both user specified and setsockopt options,
and don't allow packet length sizes that will crash */
if (((ip->ip_hl != (sizeof (*ip) >> 2)) && inp->inp_options) ||
((u_short)ntohs(ip->ip_len) > m->m_pkthdr.len)) {
error = EINVAL;
goto cantsend;
}
/* Convert fields to host order for ip_output() */
NTOHS(ip->ip_len);
NTOHS(ip->ip_off);
/* Send packet to output processing */
ipstat.ips_rawout++; /* XXX */
error = ip_output(m, inp->inp_options, &inp->inp_route,
(so->so_options & SO_DONTROUTE) |
IP_ALLOWBROADCAST | IP_RAWOUTPUT, inp->inp_moptions);
} else {
struct ifaddr *ifa;
/* Find receive interface with the given IP address */
sin->sin_port = 0;
if ((ifa = ifa_ifwithaddr((struct sockaddr *) sin)) == 0) {
error = EADDRNOTAVAIL;
goto cantsend;
}
m->m_pkthdr.rcvif = ifa->ifa_ifp;
/* Send packet to input processing */
ip_input(m);
}
/* Reset for next time (and other packets) */
ip_divert_ignore = 0;
return error;
cantsend:
ip_divert_ignore = 0;
m_freem(m);
return error;
}
/*ARGSUSED*/
int
div_usrreq(
struct socket *so,
int req,
struct mbuf *m,
struct mbuf *nam,
struct mbuf *control )
{
register int error = 0;
register struct inpcb *inp = sotoinpcb(so);
int s;
if (inp == NULL && req != PRU_ATTACH) {
error = EINVAL;
goto release;
}
switch (req) {
case PRU_ATTACH:
if (inp)
panic("div_attach");
if ((so->so_state & SS_PRIV) == 0) {
error = EACCES;
break;
}
s = splnet();
error = in_pcballoc(so, &divcbinfo);
splx(s);
if (error)
break;
error = soreserve(so, div_sendspace, div_recvspace);
if (error)
break;
inp = (struct inpcb *)so->so_pcb;
inp->inp_ip_p = (intptr_t)nam; /* XXX */
inp->inp_flags |= INP_HDRINCL;
/* The socket is always "connected" because
we always know "where" to send the packet */
so->so_state |= SS_ISCONNECTED;
break;
case PRU_DISCONNECT:
if ((so->so_state & SS_ISCONNECTED) == 0) {
error = ENOTCONN;
break;
}
/* FALLTHROUGH */
case PRU_ABORT:
soisdisconnected(so);
/* FALLTHROUGH */
case PRU_DETACH:
if (inp == 0)
panic("div_detach");
in_pcbdetach(inp);
break;
case PRU_BIND:
s = splnet();
error = in_pcbbind(inp, nam);
splx(s);
break;
/*
* Mark the connection as being incapable of further input.
*/
case PRU_SHUTDOWN:
socantsendmore(so);
break;
case PRU_SEND:
/* Packet must have a header (but that's about it) */
if (m->m_len < sizeof (struct ip) ||
(m = m_pullup(m, sizeof (struct ip))) == 0) {
ipstat.ips_toosmall++;
error = EINVAL;
break;
}
/* Send packet */
error = div_output(so, m, nam, control);
m = NULL;
break;
case PRU_SOCKADDR:
in_setsockaddr(inp, nam);
break;
case PRU_SENSE:
/*
* stat: don't bother with a blocksize.
*/
return (0);
/*
* Not supported.
*/
case PRU_CONNECT:
case PRU_CONNECT2:
case PRU_CONTROL:
case PRU_RCVOOB:
case PRU_RCVD:
case PRU_LISTEN:
case PRU_ACCEPT:
case PRU_SENDOOB:
case PRU_PEERADDR:
error = EOPNOTSUPP;
break;
default:
panic("div_usrreq");
}
release:
if (m)
m_freem(m);
return (error);
}
