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freebsd-skq/sys/netinet/ip_divert.c
Gleb Smirnoff 8f134647ca Switch the entire IPv4 stack to keep the IP packet header 
in network byte order. Any host byte order processing is
done in local variables and host byte order values are
never[1] written to a packet.

  After this change a packet processed by the stack isn't
modified at all[2] except for TTL.

  After this change a network stack hacker doesn't need to
scratch his head trying to figure out what is the byte order
at the given place in the stack.

[1] One exception still remains. The raw sockets convert host
byte order before pass a packet to an application. Probably
this would remain for ages for compatibility.

[2] The ip_input() still subtructs header len from ip->ip_len,
but this is planned to be fixed soon.

Reviewed by:	luigi, Maxim Dounin <mdounin mdounin.ru>
Tested by:	ray, Olivier Cochard-Labbe <olivier cochard.me>
2012-10-22 21:09:03 +00:00

837 lines
22 KiB
C
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/*-
* 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_inet.h"
#include "opt_inet6.h"
#include "opt_sctp.h"
#ifndef INET
#error "IPDIVERT requires INET"
#endif
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/module.h>
#include <sys/kernel.h>
#include <sys/priv.h>
#include <sys/proc.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/sysctl.h>
#include <net/vnet.h>
#include <net/if.h>
#include <net/netisr.h>
#include <netinet/in.h>
#include <netinet/in_pcb.h>
#include <netinet/in_systm.h>
#include <netinet/in_var.h>
#include <netinet/ip.h>
#include <netinet/ip_var.h>
#ifdef INET6
#include <netinet/ip6.h>
#include <netinet6/ip6_var.h>
#endif
#ifdef SCTP
#include <netinet/sctp_crc32.h>
#endif
#include <security/mac/mac_framework.h>
/*
* Divert sockets
*/
/*
* Allocate enough space to hold a full IP packet
*/
#define DIVSNDQ (65536 + 100)
#define DIVRCVQ (65536 + 100)
/*
* Divert sockets work in conjunction with ipfw or other packet filters,
* see the divert(4) manpage for features.
* Packets are selected by the packet filter and tagged with an
* MTAG_IPFW_RULE tag carrying the 'divert port' number (as set by
* the packet filter) and information on the matching filter rule for
* subsequent reinjection. The divert_port is used to put the packet
* on the corresponding divert socket, while the rule number is passed
* up (at least partially) as the sin_port in the struct sockaddr.
*
* Packets written to the divert socket carry in sin_addr a
* destination address, and in sin_port the number of the filter rule
* after which to continue processing.
* If the destination address is INADDR_ANY, the packet is treated as
* as outgoing and sent to ip_output(); otherwise it is treated as
* incoming and sent to ip_input().
* Further, sin_zero carries some information on the interface,
* which can be used in the reinject -- see comments in the code.
*
* On reinjection, processing in ip_input() and ip_output()
* will be exactly the same as for the original packet, except that
* packet filter processing will start at the rule number after the one
* written in the sin_port (ipfw does not allow a rule #0, so sin_port=0
* will apply the entire ruleset to the packet).
*/
/* Internal variables. */
static VNET_DEFINE(struct inpcbhead, divcb);
static VNET_DEFINE(struct inpcbinfo, divcbinfo);
#define V_divcb VNET(divcb)
#define V_divcbinfo VNET(divcbinfo)
static u_long div_sendspace = DIVSNDQ; /* XXX sysctl ? */
static u_long div_recvspace = DIVRCVQ; /* XXX sysctl ? */
static eventhandler_tag ip_divert_event_tag;
/*
* Initialize divert connection block queue.
*/
static void
div_zone_change(void *tag)
{
uma_zone_set_max(V_divcbinfo.ipi_zone, maxsockets);
}
static int
div_inpcb_init(void *mem, int size, int flags)
{
struct inpcb *inp = mem;
INP_LOCK_INIT(inp, "inp", "divinp");
return (0);
}
static void
div_inpcb_fini(void *mem, int size)
{
struct inpcb *inp = mem;
INP_LOCK_DESTROY(inp);
}
static void
div_init(void)
{
/*
* XXX We don't use the hash list for divert IP, but it's easier to
* allocate one-entry hash lists than it is to check all over the
* place for hashbase == NULL.
*/
in_pcbinfo_init(&V_divcbinfo, "div", &V_divcb, 1, 1, "divcb",
div_inpcb_init, div_inpcb_fini, UMA_ZONE_NOFREE,
IPI_HASHFIELDS_NONE);
}
static void
div_destroy(void)
{
in_pcbinfo_destroy(&V_divcbinfo);
}
/*
* IPPROTO_DIVERT is not in the real IP protocol number space; this
* function should never be called. Just in case, drop any packets.
*/
static void
div_input(struct mbuf *m, int off)
{
KMOD_IPSTAT_INC(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.
*/
static void
divert_packet(struct mbuf *m, int incoming)
{
struct ip *ip;
struct inpcb *inp;
struct socket *sa;
u_int16_t nport;
struct sockaddr_in divsrc;
struct m_tag *mtag;
mtag = m_tag_locate(m, MTAG_IPFW_RULE, 0, NULL);
if (mtag == NULL) {
m_freem(m);
return;
}
/* Assure header */
if (m->m_len < sizeof(struct ip) &&
(m = m_pullup(m, sizeof(struct ip))) == 0)
return;
ip = mtod(m, struct ip *);
/* Delayed checksums are currently not compatible with divert. */
if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
in_delayed_cksum(m);
m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
}
#ifdef SCTP
if (m->m_pkthdr.csum_flags & CSUM_SCTP) {
sctp_delayed_cksum(m, (uint32_t)(ip->ip_hl << 2));
m->m_pkthdr.csum_flags &= ~CSUM_SCTP;
}
#endif
bzero(&divsrc, sizeof(divsrc));
divsrc.sin_len = sizeof(divsrc);
divsrc.sin_family = AF_INET;
/* record matching rule, in host format */
divsrc.sin_port = ((struct ipfw_rule_ref *)(mtag+1))->rulenum;
/*
* Record receive interface address, if any.
* But only for incoming packets.
*/
if (incoming) {
struct ifaddr *ifa;
struct ifnet *ifp;
/* Sanity check */
M_ASSERTPKTHDR(m);
/* Find IP address for receive interface */
ifp = m->m_pkthdr.rcvif;
if_addr_rlock(ifp);
TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
if (ifa->ifa_addr->sa_family != AF_INET)
continue;
divsrc.sin_addr =
((struct sockaddr_in *) ifa->ifa_addr)->sin_addr;
break;
}
if_addr_runlock(ifp);
}
/*
* Record the incoming interface name whenever we have one.
*/
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.)
*/
strlcpy(divsrc.sin_zero, m->m_pkthdr.rcvif->if_xname,
sizeof(divsrc.sin_zero));
}
/* Put packet on socket queue, if any */
sa = NULL;
nport = htons((u_int16_t)(((struct ipfw_rule_ref *)(mtag+1))->info));
INP_INFO_RLOCK(&V_divcbinfo);
LIST_FOREACH(inp, &V_divcb, inp_list) {
/* XXX why does only one socket match? */
if (inp->inp_lport == nport) {
INP_RLOCK(inp);
sa = inp->inp_socket;
SOCKBUF_LOCK(&sa->so_rcv);
if (sbappendaddr_locked(&sa->so_rcv,
(struct sockaddr *)&divsrc, m,
(struct mbuf *)0) == 0) {
SOCKBUF_UNLOCK(&sa->so_rcv);
sa = NULL; /* force mbuf reclaim below */
} else
sorwakeup_locked(sa);
INP_RUNLOCK(inp);
break;
}
}
INP_INFO_RUNLOCK(&V_divcbinfo);
if (sa == NULL) {
m_freem(m);
KMOD_IPSTAT_INC(ips_noproto);
KMOD_IPSTAT_DEC(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(struct socket *so, struct mbuf *m, struct sockaddr_in *sin,
struct mbuf *control)
{
struct ip *const ip = mtod(m, struct ip *);
struct m_tag *mtag;
struct ipfw_rule_ref *dt;
int error = 0;
/*
* An mbuf may hasn't come from userland, but we pretend
* that it has.
*/
m->m_pkthdr.rcvif = NULL;
m->m_nextpkt = NULL;
M_SETFIB(m, so->so_fibnum);
if (control)
m_freem(control); /* XXX */
mtag = m_tag_locate(m, MTAG_IPFW_RULE, 0, NULL);
if (mtag == NULL) {
/* this should be normal */
mtag = m_tag_alloc(MTAG_IPFW_RULE, 0,
sizeof(struct ipfw_rule_ref), M_NOWAIT | M_ZERO);
if (mtag == NULL) {
error = ENOBUFS;
goto cantsend;
}
m_tag_prepend(m, mtag);
}
dt = (struct ipfw_rule_ref *)(mtag+1);
/* Loopback avoidance and state recovery */
if (sin) {
int i;
/* set the starting point. We provide a non-zero slot,
* but a non_matching chain_id to skip that info and use
* the rulenum/rule_id.
*/
dt->slot = 1; /* dummy, chain_id is invalid */
dt->chain_id = 0;
dt->rulenum = sin->sin_port+1; /* host format ? */
dt->rule_id = 0;
/*
* Find receive interface with the given name, stuffed
* (if it exists) in the sin_zero[] field.
* The name is user supplied data so don't trust its size
* or that it is zero terminated.
*/
for (i = 0; i < sizeof(sin->sin_zero) && sin->sin_zero[i]; i++)
;
if ( i > 0 && i < sizeof(sin->sin_zero))
m->m_pkthdr.rcvif = ifunit(sin->sin_zero);
}
/* Reinject packet into the system as incoming or outgoing */
if (!sin || sin->sin_addr.s_addr == 0) {
struct mbuf *options = NULL;
struct inpcb *inp;
dt->info |= IPFW_IS_DIVERT | IPFW_INFO_OUT;
inp = sotoinpcb(so);
INP_RLOCK(inp);
switch (ip->ip_v) {
case IPVERSION:
/*
* Don't allow both user specified and setsockopt
* options, and don't allow packet length sizes that
* will crash.
*/
if ((((ip->ip_hl << 2) != sizeof(struct ip)) &&
inp->inp_options != NULL) ||
((u_short)ntohs(ip->ip_len) > m->m_pkthdr.len)) {
error = EINVAL;
INP_RUNLOCK(inp);
goto cantsend;
}
break;
#ifdef INET6
case IPV6_VERSION >> 4:
{
struct ip6_hdr *const ip6 = mtod(m, struct ip6_hdr *);
/* Don't allow packet length sizes that will crash */
if (((u_short)ntohs(ip6->ip6_plen) > m->m_pkthdr.len)) {
error = EINVAL;
INP_RUNLOCK(inp);
goto cantsend;
}
break;
}
#endif
default:
error = EINVAL;
INP_RUNLOCK(inp);
goto cantsend;
}
/* Send packet to output processing */
KMOD_IPSTAT_INC(ips_rawout); /* XXX */
#ifdef MAC
mac_inpcb_create_mbuf(inp, m);
#endif
/*
* Get ready to inject the packet into ip_output().
* Just in case socket options were specified on the
* divert socket, we duplicate them. This is done
* to avoid having to hold the PCB locks over the call
* to ip_output(), as doing this results in a number of
* lock ordering complexities.
*
* Note that we set the multicast options argument for
* ip_output() to NULL since it should be invariant that
* they are not present.
*/
KASSERT(inp->inp_moptions == NULL,
("multicast options set on a divert socket"));
/*
* XXXCSJP: It is unclear to me whether or not it makes
* sense for divert sockets to have options. However,
* for now we will duplicate them with the INP locks
* held so we can use them in ip_output() without
* requring a reference to the pcb.
*/
if (inp->inp_options != NULL) {
options = m_dup(inp->inp_options, M_NOWAIT);
if (options == NULL) {
INP_RUNLOCK(inp);
error = ENOBUFS;
goto cantsend;
}
}
INP_RUNLOCK(inp);
switch (ip->ip_v) {
case IPVERSION:
error = ip_output(m, options, NULL,
((so->so_options & SO_DONTROUTE) ? IP_ROUTETOIF : 0)
| IP_ALLOWBROADCAST | IP_RAWOUTPUT, NULL, NULL);
break;
#ifdef INET6
case IPV6_VERSION >> 4:
error = ip6_output(m, NULL, NULL, 0, NULL, NULL, NULL);
break;
#endif
}
if (options != NULL)
m_freem(options);
} else {
dt->info |= IPFW_IS_DIVERT | IPFW_INFO_IN;
if (m->m_pkthdr.rcvif == NULL) {
/*
* No luck with the name, check by IP address.
* Clear the port and the ifname to make sure
* there are no distractions for ifa_ifwithaddr.
*/
struct ifaddr *ifa;
bzero(sin->sin_zero, sizeof(sin->sin_zero));
sin->sin_port = 0;
ifa = ifa_ifwithaddr((struct sockaddr *) sin);
if (ifa == NULL) {
error = EADDRNOTAVAIL;
goto cantsend;
}
m->m_pkthdr.rcvif = ifa->ifa_ifp;
ifa_free(ifa);
}
#ifdef MAC
mac_socket_create_mbuf(so, m);
#endif
/* Send packet to input processing via netisr */
switch (ip->ip_v) {
case IPVERSION:
netisr_queue_src(NETISR_IP, (uintptr_t)so, m);
break;
#ifdef INET6
case IPV6_VERSION >> 4:
netisr_queue_src(NETISR_IPV6, (uintptr_t)so, m);
break;
#endif
default:
error = EINVAL;
goto cantsend;
}
}
return (error);
cantsend:
m_freem(m);
return (error);
}
static int
div_attach(struct socket *so, int proto, struct thread *td)
{
struct inpcb *inp;
int error;
inp = sotoinpcb(so);
KASSERT(inp == NULL, ("div_attach: inp != NULL"));
if (td != NULL) {
error = priv_check(td, PRIV_NETINET_DIVERT);
if (error)
return (error);
}
error = soreserve(so, div_sendspace, div_recvspace);
if (error)
return error;
INP_INFO_WLOCK(&V_divcbinfo);
error = in_pcballoc(so, &V_divcbinfo);
if (error) {
INP_INFO_WUNLOCK(&V_divcbinfo);
return error;
}
inp = (struct inpcb *)so->so_pcb;
INP_INFO_WUNLOCK(&V_divcbinfo);
inp->inp_ip_p = proto;
inp->inp_vflag |= INP_IPV4;
inp->inp_flags |= INP_HDRINCL;
INP_WUNLOCK(inp);
return 0;
}
static void
div_detach(struct socket *so)
{
struct inpcb *inp;
inp = sotoinpcb(so);
KASSERT(inp != NULL, ("div_detach: inp == NULL"));
INP_INFO_WLOCK(&V_divcbinfo);
INP_WLOCK(inp);
in_pcbdetach(inp);
in_pcbfree(inp);
INP_INFO_WUNLOCK(&V_divcbinfo);
}
static int
div_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
{
struct inpcb *inp;
int error;
inp = sotoinpcb(so);
KASSERT(inp != NULL, ("div_bind: inp == NULL"));
/* in_pcbbind assumes that nam 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)
return EAFNOSUPPORT;
((struct sockaddr_in *)nam)->sin_addr.s_addr = INADDR_ANY;
INP_INFO_WLOCK(&V_divcbinfo);
INP_WLOCK(inp);
INP_HASH_WLOCK(&V_divcbinfo);
error = in_pcbbind(inp, nam, td->td_ucred);
INP_HASH_WUNLOCK(&V_divcbinfo);
INP_WUNLOCK(inp);
INP_INFO_WUNLOCK(&V_divcbinfo);
return error;
}
static int
div_shutdown(struct socket *so)
{
struct inpcb *inp;
inp = sotoinpcb(so);
KASSERT(inp != NULL, ("div_shutdown: inp == NULL"));
INP_WLOCK(inp);
socantsendmore(so);
INP_WUNLOCK(inp);
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) {
KMOD_IPSTAT_INC(ips_toosmall);
m_freem(m);
return EINVAL;
}
/* Send packet */
return div_output(so, m, (struct sockaddr_in *)nam, control);
}
static void
div_ctlinput(int cmd, struct sockaddr *sa, void *vip)
{
struct in_addr faddr;
faddr = ((struct sockaddr_in *)sa)->sin_addr;
if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY)
return;
if (PRC_IS_REDIRECT(cmd))
return;
}
static int
div_pcblist(SYSCTL_HANDLER_ARGS)
{
int error, i, n;
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 = V_divcbinfo.ipi_count;
n += imax(n / 8, 10);
req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xinpcb);
return 0;
}
if (req->newptr != 0)
return EPERM;
/*
* OK, now we're committed to doing something.
*/
INP_INFO_RLOCK(&V_divcbinfo);
gencnt = V_divcbinfo.ipi_gencnt;
n = V_divcbinfo.ipi_count;
INP_INFO_RUNLOCK(&V_divcbinfo);
error = sysctl_wire_old_buffer(req,
2 * sizeof(xig) + n*sizeof(struct xinpcb));
if (error != 0)
return (error);
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;
INP_INFO_RLOCK(&V_divcbinfo);
for (inp = LIST_FIRST(V_divcbinfo.ipi_listhead), i = 0; inp && i < n;
inp = LIST_NEXT(inp, inp_list)) {
INP_WLOCK(inp);
if (inp->inp_gencnt <= gencnt &&
cr_canseeinpcb(req->td->td_ucred, inp) == 0) {
in_pcbref(inp);
inp_list[i++] = inp;
}
INP_WUNLOCK(inp);
}
INP_INFO_RUNLOCK(&V_divcbinfo);
n = i;
error = 0;
for (i = 0; i < n; i++) {
inp = inp_list[i];
INP_RLOCK(inp);
if (inp->inp_gencnt <= gencnt) {
struct xinpcb xi;
bzero(&xi, sizeof(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);
INP_RUNLOCK(inp);
error = SYSCTL_OUT(req, &xi, sizeof xi);
} else
INP_RUNLOCK(inp);
}
INP_INFO_WLOCK(&V_divcbinfo);
for (i = 0; i < n; i++) {
inp = inp_list[i];
INP_RLOCK(inp);
if (!in_pcbrele_rlocked(inp))
INP_RUNLOCK(inp);
}
INP_INFO_WUNLOCK(&V_divcbinfo);
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.
*/
INP_INFO_RLOCK(&V_divcbinfo);
xig.xig_gen = V_divcbinfo.ipi_gencnt;
xig.xig_sogen = so_gencnt;
xig.xig_count = V_divcbinfo.ipi_count;
INP_INFO_RUNLOCK(&V_divcbinfo);
error = SYSCTL_OUT(req, &xig, sizeof xig);
}
free(inp_list, M_TEMP);
return error;
}
#ifdef SYSCTL_NODE
static SYSCTL_NODE(_net_inet, IPPROTO_DIVERT, divert, CTLFLAG_RW, 0,
"IPDIVERT");
SYSCTL_PROC(_net_inet_divert, OID_AUTO, pcblist, CTLTYPE_OPAQUE | CTLFLAG_RD,
NULL, 0, div_pcblist, "S,xinpcb", "List of active divert sockets");
#endif
struct pr_usrreqs div_usrreqs = {
.pru_attach = div_attach,
.pru_bind = div_bind,
.pru_control = in_control,
.pru_detach = div_detach,
.pru_peeraddr = in_getpeeraddr,
.pru_send = div_send,
.pru_shutdown = div_shutdown,
.pru_sockaddr = in_getsockaddr,
.pru_sosetlabel = in_pcbsosetlabel
};
struct protosw div_protosw = {
.pr_type = SOCK_RAW,
.pr_protocol = IPPROTO_DIVERT,
.pr_flags = PR_ATOMIC|PR_ADDR,
.pr_input = div_input,
.pr_ctlinput = div_ctlinput,
.pr_ctloutput = ip_ctloutput,
.pr_init = div_init,
#ifdef VIMAGE
.pr_destroy = div_destroy,
#endif
.pr_usrreqs = &div_usrreqs
};
static int
div_modevent(module_t mod, int type, void *unused)
{
int err = 0;
#ifndef VIMAGE
int n;
#endif
switch (type) {
case MOD_LOAD:
/*
* Protocol will be initialized by pf_proto_register().
* We don't have to register ip_protox because we are not
* a true IP protocol that goes over the wire.
*/
err = pf_proto_register(PF_INET, &div_protosw);
if (err != 0)
return (err);
ip_divert_ptr = divert_packet;
ip_divert_event_tag = EVENTHANDLER_REGISTER(maxsockets_change,
div_zone_change, NULL, EVENTHANDLER_PRI_ANY);
break;
case MOD_QUIESCE:
/*
* IPDIVERT may normally not be unloaded because of the
* potential race conditions. Tell kldunload we can't be
* unloaded unless the unload is forced.
*/
err = EPERM;
break;
case MOD_UNLOAD:
#ifdef VIMAGE
err = EPERM;
break;
#else
/*
* Forced unload.
*
* Module ipdivert can only be unloaded if no sockets are
* connected. Maybe this can be changed later to forcefully
* disconnect any open sockets.
*
* XXXRW: Note that there is a slight race here, as a new
* socket open request could be spinning on the lock and then
* we destroy the lock.
*/
INP_INFO_WLOCK(&V_divcbinfo);
n = V_divcbinfo.ipi_count;
if (n != 0) {
err = EBUSY;
INP_INFO_WUNLOCK(&V_divcbinfo);
break;
}
ip_divert_ptr = NULL;
err = pf_proto_unregister(PF_INET, IPPROTO_DIVERT, SOCK_RAW);
INP_INFO_WUNLOCK(&V_divcbinfo);
div_destroy();
EVENTHANDLER_DEREGISTER(maxsockets_change, ip_divert_event_tag);
break;
#endif /* !VIMAGE */
default:
err = EOPNOTSUPP;
break;
}
return err;
}
static moduledata_t ipdivertmod = {
"ipdivert",
div_modevent,
0
};
DECLARE_MODULE(ipdivert, ipdivertmod, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY);
MODULE_DEPEND(ipdivert, ipfw, 2, 2, 2);
MODULE_VERSION(ipdivert, 1);
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