diff options
Diffstat (limited to 'sys/netinet/ip_divert.c')
| -rw-r--r-- | sys/netinet/ip_divert.c | 781 |
1 files changed, 781 insertions, 0 deletions
diff --git a/sys/netinet/ip_divert.c b/sys/netinet/ip_divert.c new file mode 100644 index 000000000000..5a561814cdb5 --- /dev/null +++ b/sys/netinet/ip_divert.c @@ -0,0 +1,781 @@ +/*- + * SPDX-License-Identifier: BSD-3-Clause + * + * 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. 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> +#include "opt_inet.h" +#include "opt_inet6.h" +#include "opt_sctp.h" + +#include <sys/param.h> +#include <sys/eventhandler.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/domain.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/if_var.h> +#include <net/if_private.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> +#include <netinet/ip_divert.h> +#ifdef INET6 +#include <netinet/ip6.h> +#include <netinet6/ip6_var.h> +#endif +#if defined(SCTP) || defined(SCTP_SUPPORT) +#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) + +/* + * Usually a system has very few divert ports. Previous implementation + * used a linked list. + */ +#define DIVHASHSIZE (1 << 3) /* 8 entries, one cache line. */ +#define DIVHASH(port) (port % DIVHASHSIZE) +#define DCBHASH(dcb) ((dcb)->dcb_port % DIVHASHSIZE) + +/* + * 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). + */ +static SYSCTL_NODE(_net_inet, OID_AUTO, divert, CTLFLAG_RW | CTLFLAG_MPSAFE, 0, + "divert(4)"); + +VNET_PCPUSTAT_DEFINE_STATIC(struct divstat, divstat); +VNET_PCPUSTAT_SYSINIT(divstat); +#ifdef VIMAGE +VNET_PCPUSTAT_SYSUNINIT(divstat); +#endif +SYSCTL_VNET_PCPUSTAT(_net_inet_divert, OID_AUTO, stats, struct divstat, + divstat, "divert(4) socket statistics"); +#define DIVSTAT_INC(name) \ + VNET_PCPUSTAT_ADD(struct divstat, divstat, div_ ## name, 1) + +static u_long div_sendspace = DIVSNDQ; /* XXX sysctl ? */ +static u_long div_recvspace = DIVRCVQ; /* XXX sysctl ? */ + +static int div_output_inbound(int fmaily, struct socket *so, struct mbuf *m, + struct sockaddr_in *sin); +static int div_output_outbound(int family, struct socket *so, struct mbuf *m); + +struct divcb { + union { + SLIST_ENTRY(divcb) dcb_next; + intptr_t dcb_bound; +#define DCB_UNBOUND ((intptr_t)-1) + }; + struct socket *dcb_socket; + uint16_t dcb_port; + uint64_t dcb_gencnt; + struct epoch_context dcb_epochctx; +}; + +SLIST_HEAD(divhashhead, divcb); + +VNET_DEFINE_STATIC(struct divhashhead, divhash[DIVHASHSIZE]) = {}; +#define V_divhash VNET(divhash) +VNET_DEFINE_STATIC(uint64_t, dcb_count) = 0; +#define V_dcb_count VNET(dcb_count) +VNET_DEFINE_STATIC(uint64_t, dcb_gencnt) = 0; +#define V_dcb_gencnt VNET(dcb_gencnt) + +static struct mtx divert_mtx; +MTX_SYSINIT(divert, &divert_mtx, "divert(4) socket pcb lists", MTX_DEF); +#define DIVERT_LOCK() mtx_lock(&divert_mtx) +#define DIVERT_UNLOCK() mtx_unlock(&divert_mtx) + +/* + * Divert a packet by passing it up to the divert socket at port 'port'. + */ +static void +divert_packet(struct mbuf *m, bool incoming) +{ + struct divcb *dcb; + u_int16_t nport; + struct sockaddr_in divsrc; + struct m_tag *mtag; + uint16_t cookie; + + NET_EPOCH_ASSERT(); + + mtag = m_tag_locate(m, MTAG_IPFW_RULE, 0, NULL); + if (mtag != NULL) { + cookie = ((struct ipfw_rule_ref *)(mtag+1))->rulenum; + nport = htons((uint16_t) + (((struct ipfw_rule_ref *)(mtag+1))->info)); + } else if ((mtag = m_tag_locate(m, MTAG_PF_DIVERT, 0, NULL)) != NULL) { + cookie = ((struct pf_divert_mtag *)(mtag+1))->idir; + nport = htons(((struct pf_divert_mtag *)(mtag+1))->port); + } else { + m_freem(m); + return; + } + /* Assure header */ + if (m->m_len < sizeof(struct ip) && + (m = m_pullup(m, sizeof(struct ip))) == NULL) + return; +#ifdef INET + /* 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; + } +#if defined(SCTP) || defined(SCTP_SUPPORT) + if (m->m_pkthdr.csum_flags & CSUM_SCTP) { + struct ip *ip; + + ip = mtod(m, struct ip *); + sctp_delayed_cksum(m, (uint32_t)(ip->ip_hl << 2)); + m->m_pkthdr.csum_flags &= ~CSUM_SCTP; + } +#endif +#endif +#ifdef INET6 + if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) { + in6_delayed_cksum(m, m->m_pkthdr.len - + sizeof(struct ip6_hdr), sizeof(struct ip6_hdr)); + m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA_IPV6; + } +#if defined(SCTP) || defined(SCTP_SUPPORT) + if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6) { + sctp_delayed_cksum(m, sizeof(struct ip6_hdr)); + m->m_pkthdr.csum_flags &= ~CSUM_SCTP_IPV6; + } +#endif +#endif /* INET6 */ + bzero(&divsrc, sizeof(divsrc)); + divsrc.sin_len = sizeof(divsrc); + divsrc.sin_family = AF_INET; + /* record matching rule, in host format */ + divsrc.sin_port = cookie; + /* + * 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; + CK_STAILQ_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; + } + } + /* + * 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 */ + SLIST_FOREACH(dcb, &V_divhash[DIVHASH(nport)], dcb_next) + if (dcb->dcb_port == nport) + break; + + if (dcb != NULL) { + struct socket *sa = dcb->dcb_socket; + + SOCKBUF_LOCK(&sa->so_rcv); + if (sbappendaddr_locked(&sa->so_rcv, + (struct sockaddr *)&divsrc, m, NULL) == 0) { + soroverflow_locked(sa); + m_freem(m); + } else { + sorwakeup_locked(sa); + DIVSTAT_INC(diverted); + } + } else { + DIVSTAT_INC(noport); + m_freem(m); + } +} + +/* + * 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_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam, + struct mbuf *control, struct thread *td) +{ + struct epoch_tracker et; + struct sockaddr_in *sin = (struct sockaddr_in *)nam; + const struct ip *ip; + struct m_tag *mtag; + struct ipfw_rule_ref *dt; + struct pf_divert_mtag *pfdt; + int error, family; + + if (control) + m_freem(control); + + /* Packet must have a header (but that's about it) */ + if (m->m_len < sizeof (struct ip) && + (m = m_pullup(m, sizeof (struct ip))) == NULL) { + m_freem(m); + return (EINVAL); + } + + if (sin != NULL) { + if (sin->sin_family != AF_INET) { + m_freem(m); + return (EAFNOSUPPORT); + } + if (sin->sin_len != sizeof(*sin)) { + m_freem(m); + return (EINVAL); + } + } + + /* + * 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); + + 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) { + m_freem(m); + return (ENOBUFS); + } + 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; + /* XXX: broken for IPv6 */ + /* + * 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); + } + + ip = mtod(m, struct ip *); + switch (ip->ip_v) { +#ifdef INET + case IPVERSION: + family = AF_INET; + break; +#endif +#ifdef INET6 + case IPV6_VERSION >> 4: + family = AF_INET6; + break; +#endif + default: + m_freem(m); + return (EAFNOSUPPORT); + } + + mtag = m_tag_locate(m, MTAG_PF_DIVERT, 0, NULL); + if (mtag == NULL) { + /* this should be normal */ + mtag = m_tag_alloc(MTAG_PF_DIVERT, 0, + sizeof(struct pf_divert_mtag), M_NOWAIT | M_ZERO); + if (mtag == NULL) { + m_freem(m); + return (ENOBUFS); + } + m_tag_prepend(m, mtag); + } + pfdt = (struct pf_divert_mtag *)(mtag+1); + if (sin) + pfdt->idir = sin->sin_port; + + /* Reinject packet into the system as incoming or outgoing */ + NET_EPOCH_ENTER(et); + if (!sin || sin->sin_addr.s_addr == 0) { + dt->info |= IPFW_IS_DIVERT | IPFW_INFO_OUT; + pfdt->ndir = PF_DIVERT_MTAG_DIR_OUT; + error = div_output_outbound(family, so, m); + } else { + dt->info |= IPFW_IS_DIVERT | IPFW_INFO_IN; + pfdt->ndir = PF_DIVERT_MTAG_DIR_IN; + error = div_output_inbound(family, so, m, sin); + } + NET_EPOCH_EXIT(et); + + return (error); +} + +/* + * Sends mbuf @m to the wire via ip[6]_output(). + * + * Returns 0 on success or an errno value on failure. @m is always consumed. + */ +static int +div_output_outbound(int family, struct socket *so, struct mbuf *m) +{ + int error; + + switch (family) { +#ifdef INET + case AF_INET: + { + struct ip *const ip = mtod(m, struct ip *); + + /* Don't allow packet length sizes that will crash. */ + if (((u_short)ntohs(ip->ip_len) > m->m_pkthdr.len)) { + m_freem(m); + return (EINVAL); + } + break; + } +#endif +#ifdef INET6 + case AF_INET6: + { + 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)) { + m_freem(m); + return (EINVAL); + } + break; + } +#endif + } + +#ifdef MAC + mac_socket_create_mbuf(so, m); +#endif + + error = 0; + switch (family) { +#ifdef INET + case AF_INET: + error = ip_output(m, NULL, NULL, + ((so->so_options & SO_DONTROUTE) ? IP_ROUTETOIF : 0) + | IP_ALLOWBROADCAST | IP_RAWOUTPUT, NULL, NULL); + break; +#endif +#ifdef INET6 + case AF_INET6: + error = ip6_output(m, NULL, NULL, 0, NULL, NULL, NULL); + break; +#endif + } + if (error == 0) + DIVSTAT_INC(outbound); + + return (error); +} + +/* + * Schedules mbuf @m for local processing via IPv4/IPv6 netisr queue. + * + * Returns 0 on success or an errno value on failure. @m is always consumed. + */ +static int +div_output_inbound(int family, struct socket *so, struct mbuf *m, + struct sockaddr_in *sin) +{ + struct ifaddr *ifa; + + 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. + */ + + /* XXX: broken for IPv6 */ + bzero(sin->sin_zero, sizeof(sin->sin_zero)); + sin->sin_port = 0; + ifa = ifa_ifwithaddr((struct sockaddr *) sin); + if (ifa == NULL) { + m_freem(m); + return (EADDRNOTAVAIL); + } + m->m_pkthdr.rcvif = ifa->ifa_ifp; + } +#ifdef MAC + mac_socket_create_mbuf(so, m); +#endif + /* Send packet to input processing via netisr */ + switch (family) { +#ifdef INET + case AF_INET: + { + const struct ip *ip; + + ip = mtod(m, struct ip *); + /* + * Restore M_BCAST flag when destination address is + * broadcast. It is expected by ip_tryforward(). + */ + if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) + m->m_flags |= M_MCAST; + else if (in_ifnet_broadcast(ip->ip_dst, m->m_pkthdr.rcvif)) + m->m_flags |= M_BCAST; + netisr_queue_src(NETISR_IP, (uintptr_t)so, m); + DIVSTAT_INC(inbound); + break; + } +#endif +#ifdef INET6 + case AF_INET6: + netisr_queue_src(NETISR_IPV6, (uintptr_t)so, m); + DIVSTAT_INC(inbound); + break; +#endif + default: + m_freem(m); + return (EINVAL); + } + + return (0); +} + +static int +div_attach(struct socket *so, int proto, struct thread *td) +{ + struct divcb *dcb; + int error; + + 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; + dcb = malloc(sizeof(*dcb), M_PCB, M_WAITOK); + dcb->dcb_bound = DCB_UNBOUND; + dcb->dcb_socket = so; + DIVERT_LOCK(); + V_dcb_count++; + dcb->dcb_gencnt = ++V_dcb_gencnt; + DIVERT_UNLOCK(); + so->so_pcb = dcb; + + return (0); +} + +static void +div_free(epoch_context_t ctx) +{ + struct divcb *dcb = __containerof(ctx, struct divcb, dcb_epochctx); + + free(dcb, M_PCB); +} + +static void +div_detach(struct socket *so) +{ + struct divcb *dcb = so->so_pcb; + + so->so_pcb = NULL; + DIVERT_LOCK(); + if (dcb->dcb_bound != DCB_UNBOUND) + SLIST_REMOVE(&V_divhash[DCBHASH(dcb)], dcb, divcb, dcb_next); + V_dcb_count--; + V_dcb_gencnt++; + DIVERT_UNLOCK(); + NET_EPOCH_CALL(div_free, &dcb->dcb_epochctx); +} + +static int +div_bind(struct socket *so, struct sockaddr *nam, struct thread *td) +{ + struct divcb *dcb; + uint16_t port; + + if (nam->sa_family != AF_INET) + return EAFNOSUPPORT; + if (nam->sa_len != sizeof(struct sockaddr_in)) + return EINVAL; + port = ((struct sockaddr_in *)nam)->sin_port; + DIVERT_LOCK(); + SLIST_FOREACH(dcb, &V_divhash[DIVHASH(port)], dcb_next) + if (dcb->dcb_port == port) { + DIVERT_UNLOCK(); + return (EADDRINUSE); + } + dcb = so->so_pcb; + if (dcb->dcb_bound != DCB_UNBOUND) + SLIST_REMOVE(&V_divhash[DCBHASH(dcb)], dcb, divcb, dcb_next); + dcb->dcb_port = port; + SLIST_INSERT_HEAD(&V_divhash[DIVHASH(port)], dcb, dcb_next); + DIVERT_UNLOCK(); + + return (0); +} + +static int +div_pcblist(SYSCTL_HANDLER_ARGS) +{ + struct xinpgen xig; + struct divcb *dcb; + int error; + + if (req->newptr != 0) + return EPERM; + + if (req->oldptr == 0) { + u_int n; + + n = V_dcb_count; + n += imax(n / 8, 10); + req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xinpcb); + return 0; + } + + if ((error = sysctl_wire_old_buffer(req, 0)) != 0) + return (error); + + bzero(&xig, sizeof(xig)); + xig.xig_len = sizeof xig; + xig.xig_count = V_dcb_count; + xig.xig_gen = V_dcb_gencnt; + xig.xig_sogen = so_gencnt; + error = SYSCTL_OUT(req, &xig, sizeof xig); + if (error) + return error; + + DIVERT_LOCK(); + for (int i = 0; i < DIVHASHSIZE; i++) + SLIST_FOREACH(dcb, &V_divhash[i], dcb_next) { + if (dcb->dcb_gencnt <= xig.xig_gen) { + struct xinpcb xi; + + bzero(&xi, sizeof(xi)); + xi.xi_len = sizeof(struct xinpcb); + sotoxsocket(dcb->dcb_socket, &xi.xi_socket); + xi.inp_gencnt = dcb->dcb_gencnt; + xi.inp_vflag = INP_IPV4; /* XXX: netstat(1) */ + xi.inp_inc.inc_ie.ie_lport = dcb->dcb_port; + error = SYSCTL_OUT(req, &xi, sizeof xi); + if (error) + goto errout; + } + } + + /* + * 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. + */ + xig.xig_gen = V_dcb_gencnt; + xig.xig_sogen = so_gencnt; + xig.xig_count = V_dcb_count; + error = SYSCTL_OUT(req, &xig, sizeof xig); + +errout: + DIVERT_UNLOCK(); + + return (error); +} +SYSCTL_PROC(_net_inet_divert, OID_AUTO, pcblist, + CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, 0, div_pcblist, + "S,xinpcb", "List of active divert sockets"); + +static struct protosw div_protosw = { + .pr_type = SOCK_RAW, + .pr_flags = PR_ATOMIC|PR_ADDR, + .pr_attach = div_attach, + .pr_bind = div_bind, + .pr_detach = div_detach, + .pr_send = div_send, +}; + +static struct domain divertdomain = { + .dom_family = PF_DIVERT, + .dom_name = "divert", + .dom_nprotosw = 1, + .dom_protosw = { &div_protosw }, +}; + +static int +div_modevent(module_t mod, int type, void *unused) +{ + int err = 0; + + switch (type) { + case MOD_LOAD: + domain_add(&divertdomain); + ip_divert_ptr = divert_packet; + 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: + /* + * 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. + * + * XXXGL: One more reason this code is incorrect is that it + * checks only the current vnet. + */ + DIVERT_LOCK(); + if (V_dcb_count != 0) { + DIVERT_UNLOCK(); + err = EBUSY; + break; + } + DIVERT_UNLOCK(); + ip_divert_ptr = NULL; + domain_remove(&divertdomain); + break; + default: + err = EOPNOTSUPP; + break; + } + return err; +} + +static moduledata_t ipdivertmod = { + "ipdivert", + div_modevent, + 0 +}; + +DECLARE_MODULE(ipdivert, ipdivertmod, SI_SUB_PROTO_FIREWALL, SI_ORDER_ANY); +MODULE_VERSION(ipdivert, 1); |