freebsd-dev/sys/netinet/ip_divert.c
Mike Barcroft fd8e4ebc8c o Move NTOHL() and associated macros into <sys/param.h>. These are
deprecated in favor of the POSIX-defined lowercase variants.
o Change all occurrences of NTOHL() and associated marcros in the
  source tree to use the lowercase function variants.
o Add missing license bits to sparc64's <machine/endian.h>.
  Approved by: jake
o Clean up <machine/endian.h> files.
o Remove unused __uint16_swap_uint32() from i386's <machine/endian.h>.
o Remove prototypes for non-existent bswapXX() functions.
o Include <machine/endian.h> in <arpa/inet.h> to define the
  POSIX-required ntohl() family of functions.
o Do similar things to expose the ntohl() family in libstand, <netinet/in.h>,
  and <sys/param.h>.
o Prepend underscores to the ntohl() family to help deal with
  complexities associated with having MD (asm and inline) versions, and
  having to prevent exposure of these functions in other headers that
  happen to make use of endian-specific defines.
o Create weak aliases to the canonical function name to help deal with
  third-party software forgetting to include an appropriate header.
o Remove some now unneeded pollution from <sys/types.h>.
o Add missing <arpa/inet.h> includes in userland.

Tested on:	alpha, i386
Reviewed by:	bde, jake, tmm
2002-02-18 20:35:27 +00:00

539 lines
14 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.
*
* $FreeBSD$
*/
#include "opt_inet.h"
#include "opt_ipfw.h"
#include "opt_ipdivert.h"
#include "opt_ipsec.h"
#ifndef INET
#error "IPDIVERT requires INET."
#endif
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/proc.h>
#include <sys/socket.h>
#include <sys/protosw.h>
#include <sys/socketvar.h>
#include <sys/sysctl.h>
#include <sys/systm.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)
/*
* A 16 bit cookie is passed to and from the user process.
* The user process can send it back to help the caller know
* something about where the packet originally came from.
*
* In the case of ipfw, 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.
*
* For divert_packet(), ip_divert_cookie is an input value only.
* For div_output(), ip_divert_cookie is an output value only.
*/
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);
}
/*
* IPPROTO_DIVERT is not a real IP protocol; don't allow any packets
* with that protocol number to enter the system from the outside.
*/
void
div_input(struct mbuf *m, int off)
{
ipstat.ips_noproto++;
m_freem(m);
}
/*
* Divert a packet by passing it up to the divert socket at port 'port'.
*
* Setup generic address and protocol structures for div_input routine,
* then pass them along with mbuf chain.
*/
void
divert_packet(struct mbuf *m, int incoming, int port)
{
struct ip *ip;
struct inpcb *inp;
struct socket *sa;
u_int16_t nport;
/* Sanity check */
KASSERT(port != 0, ("%s: port=0", __func__));
/* Record and reset divert cookie */
divsrc.sin_port = ip_divert_cookie;
ip_divert_cookie = 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 receive interface address, if any.
* But only for incoming packets.
*/
divsrc.sin_addr.s_addr = 0;
if (incoming) {
struct ifaddr *ifa;
/* Sanity check */
KASSERT((m->m_flags & M_PKTHDR), ("%s: !PKTHDR", __func__));
/* Find IP address for receive interface */
TAILQ_FOREACH(ifa, &m->m_pkthdr.rcvif->if_addrhead, ifa_link) {
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;
}
}
/*
* Record the incoming interface name whenever we have one.
*/
bzero(&divsrc.sin_zero, sizeof(divsrc.sin_zero));
if (m->m_pkthdr.rcvif) {
/*
* 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.)
*/
snprintf(divsrc.sin_zero, sizeof(divsrc.sin_zero),
"%s%d", m->m_pkthdr.rcvif->if_name,
m->m_pkthdr.rcvif->if_unit);
}
/* Put packet on socket queue, if any */
sa = NULL;
nport = htons((u_int16_t)port);
LIST_FOREACH(inp, &divcb, inp_list) {
if (inp->inp_lport == nport)
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.
*/
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;
ip_divert_cookie = sin->sin_port;
/*
* 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() */
ip->ip_len = ntohs(ip->ip_len);
ip->ip_off = 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) {
/*
* Make sure there are no distractions
* for ifa_ifwithaddr. Clear the port and the ifname.
* Maybe zap all 8 bytes at once using a 64bit write?
*/
bzero(sin->sin_zero, sizeof(sin->sin_zero));
/* *((u_int64_t *)sin->sin_zero) = 0; */ /* XXX ?? */
sin->sin_port = 0;
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:
m_freem(m);
ip_divert_cookie = 0;
return error;
}
static int
div_attach(struct socket *so, int proto, struct thread *td)
{
struct inpcb *inp;
int error, s;
inp = sotoinpcb(so);
if (inp)
panic("div_attach");
if (td && (error = suser_td(td)) != 0)
return error;
error = soreserve(so, div_sendspace, div_recvspace);
if (error)
return error;
s = splnet();
error = in_pcballoc(so, &divcbinfo, td);
splx(s);
if (error)
return error;
inp = (struct inpcb *)so->so_pcb;
inp->inp_ip_p = proto;
inp->inp_vflag |= INP_IPV4;
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 thread *td)
{
struct inpcb *inp;
int s;
int error;
s = splnet();
inp = sotoinpcb(so);
/* in_pcbbind assumes that the socket is a sockaddr_in
* and in_pcbbind requires a valid address. Since divert
* sockets don't we need to make sure the address is
* filled in properly.
* XXX -- divert should not be abusing in_pcbind
* and should probably have its own family.
*/
if (nam->sa_family != AF_INET) {
error = EAFNOSUPPORT;
} else {
((struct sockaddr_in *)nam)->sin_addr.s_addr = INADDR_ANY;
error = in_pcbbind(inp, nam, td);
}
splx(s);
return error;
}
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 thread *td)
{
/* 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);
}
static int
div_pcblist(SYSCTL_HANDLER_ARGS)
{
int error, i, n, s;
struct inpcb *inp, **inp_list;
inp_gen_t gencnt;
struct xinpgen xig;
/*
* The process of preparing the TCB list is too time-consuming and
* resource-intensive to repeat twice on every request.
*/
if (req->oldptr == 0) {
n = divcbinfo.ipi_count;
req->oldidx = 2 * (sizeof xig)
+ (n + n/8) * sizeof(struct xinpcb);
return 0;
}
if (req->newptr != 0)
return EPERM;
/*
* OK, now we're committed to doing something.
*/
s = splnet();
gencnt = divcbinfo.ipi_gencnt;
n = divcbinfo.ipi_count;
splx(s);
xig.xig_len = sizeof xig;
xig.xig_count = n;
xig.xig_gen = gencnt;
xig.xig_sogen = so_gencnt;
error = SYSCTL_OUT(req, &xig, sizeof xig);
if (error)
return error;
inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK);
if (inp_list == 0)
return ENOMEM;
s = splnet();
for (inp = LIST_FIRST(divcbinfo.listhead), i = 0; inp && i < n;
inp = LIST_NEXT(inp, inp_list)) {
if (inp->inp_gencnt <= gencnt && !prison_xinpcb(
req->td->td_proc, inp))
inp_list[i++] = inp;
}
splx(s);
n = i;
error = 0;
for (i = 0; i < n; i++) {
inp = inp_list[i];
if (inp->inp_gencnt <= gencnt) {
struct xinpcb xi;
xi.xi_len = sizeof xi;
/* XXX should avoid extra copy */
bcopy(inp, &xi.xi_inp, sizeof *inp);
if (inp->inp_socket)
sotoxsocket(inp->inp_socket, &xi.xi_socket);
error = SYSCTL_OUT(req, &xi, sizeof xi);
}
}
if (!error) {
/*
* Give the user an updated idea of our state.
* If the generation differs from what we told
* her before, she knows that something happened
* while we were processing this request, and it
* might be necessary to retry.
*/
s = splnet();
xig.xig_gen = divcbinfo.ipi_gencnt;
xig.xig_sogen = so_gencnt;
xig.xig_count = divcbinfo.ipi_count;
splx(s);
error = SYSCTL_OUT(req, &xig, sizeof xig);
}
free(inp_list, M_TEMP);
return error;
}
SYSCTL_DECL(_net_inet_divert);
SYSCTL_PROC(_net_inet_divert, OID_AUTO, pcblist, CTLFLAG_RD, 0, 0,
div_pcblist, "S,xinpcb", "List of active divert sockets");
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
};