447 lines
12 KiB
C
447 lines
12 KiB
C
/*
|
|
* 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.
|
|
* 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.
|
|
*
|
|
* $Id: ip_divert.c,v 1.30 1998/06/12 01:54:29 julian Exp $
|
|
*/
|
|
|
|
#include "opt_inet.h"
|
|
#include "opt_ipfw.h"
|
|
#include "opt_ipdivert.h"
|
|
|
|
#ifndef INET
|
|
#error "IPDIVERT requires INET."
|
|
#endif
|
|
|
|
#include <sys/param.h>
|
|
#include <sys/malloc.h>
|
|
#include <sys/mbuf.h>
|
|
#include <sys/socket.h>
|
|
#include <sys/protosw.h>
|
|
#include <sys/socketvar.h>
|
|
#include <sys/systm.h>
|
|
#include <sys/proc.h>
|
|
|
|
#include <vm/vm_zone.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;
|
|
|
|
/*
|
|
* #ifdef IPFW_DIVERT_OLDRESTART
|
|
* 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.
|
|
* #else
|
|
* A 16 bit cookie is passed to the user process.
|
|
* The user process can send it back to help the caller know something
|
|
* about where the packet came from.
|
|
*
|
|
* If IPFW is the caller then the cookie is the rule that sent
|
|
* us here. On reinjection is is the rule after which processing
|
|
* should continue. Leaving it the same will make processing start
|
|
* at the rule number after that which sent it here. Setting it to
|
|
* 0 will restart processing at the beginning.
|
|
* #endif
|
|
*/
|
|
u_int16_t ip_divert_cookie;
|
|
|
|
/* 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 sockaddr *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);
|
|
divcbinfo.porthashbase = hashinit(1, M_PCB, &divcbinfo.porthashmask);
|
|
divcbinfo.ipi_zone = zinit("divcb", sizeof(struct inpcb),
|
|
maxsockets, ZONE_INTERRUPT, 0);
|
|
}
|
|
|
|
/*
|
|
* 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 */
|
|
#ifdef IPFW_DIVERT_OLDRESTART
|
|
divsrc.sin_port = htons(ip_divert_cookie);
|
|
#else
|
|
divsrc.sin_port = ip_divert_cookie;
|
|
#endif /* IPFW_DIVERT_OLDRESTART */
|
|
ip_divert_cookie = 0;
|
|
|
|
/* 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 receive interface */
|
|
for (ifa = m->m_pkthdr.rcvif->if_addrhead.tqh_first;
|
|
ifa != NULL; ifa = ifa->ifa_link.tqe_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;
|
|
}
|
|
}
|
|
if (m->m_pkthdr.rcvif) {
|
|
char name[32];
|
|
/*
|
|
* Hide the actual interface name in there in the
|
|
* sin_zero array. XXX This needs to be moved to a
|
|
* different sockaddr type for divert, e.g.
|
|
* sockaddr_div with multiple fields like
|
|
* sockaddr_dl. Presently we have only 7 bytes
|
|
* but that will do for now as most interfaces
|
|
* are 4 or less + 2 or less bytes for unit.
|
|
* There is probably a faster way of doing this,
|
|
* possibly taking it from the sockaddr_dl on the iface.
|
|
* This solves the problem of a P2P link and a LAN interface
|
|
* having the same address, which can result in the wrong
|
|
* interface being assigned to the packet when fed back
|
|
* into the divert socket. Theoretically if the daemon saves
|
|
* and re-uses the sockaddr_in as suggested in the man pages,
|
|
* this iface name will come along for the ride.
|
|
* (see div_output for the other half of this.)
|
|
*/
|
|
sprintf(name, "%s%d",
|
|
m->m_pkthdr.rcvif->if_name, m->m_pkthdr.rcvif->if_unit);
|
|
strncpy(divsrc.sin_zero, name, 7);
|
|
}
|
|
|
|
/* 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(so, m, addr, control)
|
|
struct socket *so;
|
|
register struct mbuf *m;
|
|
struct sockaddr *addr;
|
|
struct mbuf *control;
|
|
{
|
|
register struct inpcb *const inp = sotoinpcb(so);
|
|
register struct ip *const ip = mtod(m, struct ip *);
|
|
struct sockaddr_in *sin = (struct sockaddr_in *)addr;
|
|
int error = 0;
|
|
|
|
if (control)
|
|
m_freem(control); /* XXX */
|
|
|
|
/* Loopback avoidance and state recovery */
|
|
if (sin) {
|
|
int len = 0;
|
|
char *c = sin->sin_zero;
|
|
#ifdef IPFW_DIVERT_OLDRESTART
|
|
ip_divert_cookie = ntohs(sin->sin_port);
|
|
#else
|
|
ip_divert_cookie = sin->sin_port;
|
|
#endif /* IPFW_DIVERT_OLDRESTART */
|
|
|
|
/*
|
|
* Find receive interface with the given name or IP address.
|
|
* The name is user supplied data so don't trust it's size or
|
|
* that it is zero terminated. The name has priority.
|
|
* We are presently assuming that the sockaddr_in
|
|
* has not been replaced by a sockaddr_div, so we limit it
|
|
* to 16 bytes in total. the name is stuffed (if it exists)
|
|
* in the sin_zero[] field.
|
|
*/
|
|
while (*c++ && (len++ < sizeof(sin->sin_zero)));
|
|
if ((len > 0) && (len < sizeof(sin->sin_zero)))
|
|
m->m_pkthdr.rcvif = ifunit(sin->sin_zero);
|
|
} else {
|
|
ip_divert_cookie = 0;
|
|
}
|
|
|
|
/* 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;
|
|
|
|
/* If no luck with the name above. check by IP address. */
|
|
if (m->m_pkthdr.rcvif == NULL) {
|
|
if (!(ifa = ifa_ifwithaddr((struct sockaddr *) sin))) {
|
|
error = EADDRNOTAVAIL;
|
|
goto cantsend;
|
|
}
|
|
m->m_pkthdr.rcvif = ifa->ifa_ifp;
|
|
}
|
|
|
|
/* Send packet to input processing */
|
|
ip_input(m);
|
|
}
|
|
|
|
/* paranoid: Reset for next time (and other packets) */
|
|
/* almost definitly already done in the ipfw filter but.. */
|
|
ip_divert_cookie = 0;
|
|
return error;
|
|
|
|
cantsend:
|
|
ip_divert_cookie = 0;
|
|
m_freem(m);
|
|
return error;
|
|
}
|
|
|
|
static int
|
|
div_attach(struct socket *so, int proto, struct proc *p)
|
|
{
|
|
struct inpcb *inp;
|
|
int error, s;
|
|
|
|
inp = sotoinpcb(so);
|
|
if (inp)
|
|
panic("div_attach");
|
|
if (p && (error = suser(p->p_ucred, &p->p_acflag)) != 0)
|
|
return error;
|
|
|
|
s = splnet();
|
|
error = in_pcballoc(so, &divcbinfo, p);
|
|
splx(s);
|
|
if (error)
|
|
return error;
|
|
error = soreserve(so, div_sendspace, div_recvspace);
|
|
if (error)
|
|
return error;
|
|
inp = (struct inpcb *)so->so_pcb;
|
|
inp->inp_ip_p = proto;
|
|
inp->inp_flags |= INP_HDRINCL;
|
|
/* The socket is always "connected" because
|
|
we always know "where" to send the packet */
|
|
so->so_state |= SS_ISCONNECTED;
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
div_detach(struct socket *so)
|
|
{
|
|
struct inpcb *inp;
|
|
|
|
inp = sotoinpcb(so);
|
|
if (inp == 0)
|
|
panic("div_detach");
|
|
in_pcbdetach(inp);
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
div_abort(struct socket *so)
|
|
{
|
|
soisdisconnected(so);
|
|
return div_detach(so);
|
|
}
|
|
|
|
static int
|
|
div_disconnect(struct socket *so)
|
|
{
|
|
if ((so->so_state & SS_ISCONNECTED) == 0)
|
|
return ENOTCONN;
|
|
return div_abort(so);
|
|
}
|
|
|
|
static int
|
|
div_bind(struct socket *so, struct sockaddr *nam, struct proc *p)
|
|
{
|
|
struct inpcb *inp;
|
|
int s;
|
|
int error;
|
|
|
|
s = splnet();
|
|
inp = sotoinpcb(so);
|
|
error = in_pcbbind(inp, nam, p);
|
|
splx(s);
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
div_shutdown(struct socket *so)
|
|
{
|
|
socantsendmore(so);
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
div_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam,
|
|
struct mbuf *control, struct proc *p)
|
|
{
|
|
/* 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++;
|
|
m_freem(m);
|
|
return EINVAL;
|
|
}
|
|
|
|
/* Send packet */
|
|
return div_output(so, m, nam, control);
|
|
}
|
|
|
|
struct pr_usrreqs div_usrreqs = {
|
|
div_abort, pru_accept_notsupp, div_attach, div_bind,
|
|
pru_connect_notsupp, pru_connect2_notsupp, in_control, div_detach,
|
|
div_disconnect, pru_listen_notsupp, in_setpeeraddr, pru_rcvd_notsupp,
|
|
pru_rcvoob_notsupp, div_send, pru_sense_null, div_shutdown,
|
|
in_setsockaddr, sosend, soreceive, sopoll
|
|
};
|