diff --git a/share/man/man4/divert.4 b/share/man/man4/divert.4 index cfe1a31486c9..18da54ee9fc9 100644 --- a/share/man/man4/divert.4 +++ b/share/man/man4/divert.4 @@ -1,200 +1,199 @@ .\" $FreeBSD$ .\" .Dd August 30, 2022 .Dt DIVERT 4 .Os .Sh NAME .Nm divert .Nd kernel packet diversion mechanism .Sh SYNOPSIS .In sys/types.h .In sys/socket.h .In netinet/in.h .Ft int .Fn socket PF_DIVERT SOCK_RAW 0 .Pp To enable support for divert sockets, place the following lines in the kernel configuration file: .Bd -ragged -offset indent .Cd "options IPFIREWALL" .Cd "options IPDIVERT" .Ed .Pp Alternatively, to load the driver as a module at boot time, add the following lines into the .Xr loader.conf 5 file: .Bd -literal -offset indent ipfw_load="YES" ipdivert_load="YES" .Ed .Sh DESCRIPTION Divert sockets allow to intercept and re-inject packets flowing through the .Xr ipfw 4 firewall. A divert socket can be bound to a specific .Nm port via the .Xr bind 2 system call. The sockaddr argument shall be sockaddr_in with sin_port set to the desired value. Note that the .Nm port has nothing to do with TCP/UDP ports. It is just a cookie number, that allows to differentiate between different divert points in the .Xr ipfw 4 ruleset. A divert socket bound to a divert port will receive all packets diverted to that port by .Xr ipfw 4 . Packets may also be written to a divert port, in which case they re-enter firewall processing at the next rule. .Pp By reading from and writing to a divert socket, matching packets can be passed through an arbitrary ``filter'' as they travel through the host machine, special routing tricks can be done, etc. .Sh READING PACKETS Packets are diverted either as they are ``incoming'' or ``outgoing.'' Incoming packets are diverted after reception on an IP interface, whereas outgoing packets are diverted before next hop forwarding. .Pp Diverted packets may be read unaltered via .Xr read 2 , .Xr recv 2 , or .Xr recvfrom 2 . In the latter case, the address returned will have its port set to some tag supplied by the packet diverter, (usually the ipfw rule number) and the IP address set to the (first) address of the interface on which the packet was received (if the packet was incoming) or .Dv INADDR_ANY (if the packet was outgoing). The interface name (if defined for the packet) will be placed in the 8 bytes following the address, if it fits. .Sh WRITING PACKETS Writing to a divert socket is similar to writing to a raw IP socket; the packet is injected ``as is'' into the normal kernel IP packet processing using .Xr sendto 2 and minimal error checking is done. Packets are distinguished as either incoming or outgoing. If .Xr sendto 2 is used with a destination IP address of .Dv INADDR_ANY , then the packet is treated as if it were outgoing, i.e., destined for a non-local address. Otherwise, the packet is assumed to be incoming and full packet routing is done. .Pp In the latter case, the IP address specified must match the address of some local interface, or an interface name must be found after the IP address. If an interface name is found, that interface will be used and the value of the IP address will be ignored (other than the fact that it is not .Dv INADDR_ANY ) . This is to indicate on which interface the packet .Dq arrived . .Pp Normally, packets read as incoming should be written as incoming; similarly for outgoing packets. When reading and then writing back packets, passing the same socket address supplied by .Xr recvfrom 2 unmodified to .Xr sendto 2 simplifies things (see below). .Pp The port part of the socket address passed to the .Xr sendto 2 contains a tag that should be meaningful to the diversion module. In the case of .Xr ipfw 8 the tag is interpreted as the rule number .Em after which rule processing should restart. .Sh LOOP AVOIDANCE Packets written into a divert socket (using .Xr sendto 2 ) re-enter the packet filter at the rule number following the tag given in the port part of the socket address, which is usually already set at the rule number that caused the diversion (not the next rule if there are several at the same number). If the 'tag' is altered to indicate an alternative re-entry point, care should be taken to avoid loops, where the same packet is diverted more than once at the same rule. .Sh DETAILS If a packet is diverted but no socket is bound to the port, or if .Dv IPDIVERT is not enabled or loaded in the kernel, the packet is dropped. .Pp Incoming packet fragments which get diverted are fully reassembled before delivery; the diversion of any one fragment causes the entire packet to get diverted. If different fragments divert to different ports, then which port ultimately gets chosen is unpredictable. .Pp Note that packets arriving on the divert socket by the .Xr ipfw 8 .Cm tee action are delivered as-is and packet fragments do not get reassembled in this case. .Pp Packets are received and sent unchanged, except that packets read as outgoing have invalid IP header checksums, and packets written as outgoing have their IP header checksums overwritten with the correct value. Packets written as incoming and having incorrect checksums will be dropped. Otherwise, all header fields are unchanged (and therefore in network order). .Pp -Binding to port numbers less than 1024 requires super-user access, as does -creating a +Creating a .Nm -socket. +socket requires super-user access. .Sh ERRORS Writing to a divert socket can return these errors, along with the usual errors possible when writing raw packets: .Bl -tag -width Er .It Bq Er EINVAL The packet had an invalid header, or the IP options in the packet and the socket options set were incompatible. .It Bq Er EADDRNOTAVAIL The destination address contained an IP address not equal to .Dv INADDR_ANY that was not associated with any interface. .El .Sh SEE ALSO .Xr bind 2 , .Xr recvfrom 2 , .Xr sendto 2 , .Xr socket 2 , .Xr ipfw 4 , .Xr ipfw 8 .Sh AUTHORS .An Archie Cobbs Aq Mt archie@FreeBSD.org , Whistle Communications Corp. .Sh BUGS This is an attempt to provide a clean way for user mode processes to implement various IP tricks like address translation, but it could be cleaner, and it is too dependent on .Xr ipfw 8 . .Pp It is questionable whether incoming fragments should be reassembled before being diverted. For example, if only some fragments of a packet destined for another machine do not get routed through the local machine, the packet is lost. This should probably be a settable socket option in any case. diff --git a/sys/netinet/ip_divert.c b/sys/netinet/ip_divert.c index 0cecbbd0d15d..7e0a09bd8e3a 100644 --- a/sys/netinet/ip_divert.c +++ b/sys/netinet/ip_divert.c @@ -1,806 +1,756 @@ /*- * 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 __FBSDID("$FreeBSD$"); #include "opt_inet.h" #include "opt_inet6.h" #include "opt_sctp.h" #ifndef INET #error "IPDIVERT requires INET" /* XXX! */ #endif #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef INET6 #include #include #endif #if defined(SCTP) || defined(SCTP_SUPPORT) #include #endif #include /* * 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) -VNET_DEFINE_STATIC(struct inpcbinfo, divcbinfo); -#define V_divcbinfo VNET(divcbinfo) - 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); -/* - * Initialize divert connection block queue. - */ -INPCBSTORAGE_DEFINE(divcbstor, "divinp", "divcb", "div", "divhash"); - -static void -div_init(void *arg __unused) -{ - - /* - * 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, &divcbstor, 1, 1); -} -VNET_SYSINIT(div_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_THIRD, div_init, NULL); - -static void -div_destroy(void *unused __unused) -{ +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; +}; - in_pcbinfo_destroy(&V_divcbinfo); -} -VNET_SYSUNINIT(divert, SI_SUB_PROTO_DOMAIN, SI_ORDER_THIRD, div_destroy, NULL); +SLIST_HEAD(divhashhead, divcb); -static bool -div_port_match(const struct inpcb *inp, void *v) -{ - uint16_t nport = *(uint16_t *)v; +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) - return (inp->inp_lport == nport); -} +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) { #if defined(SCTP) || defined(SCTP_SUPPORT) struct ip *ip; #endif - struct inpcb *inp; - struct socket *sa; + struct divcb *dcb; u_int16_t nport; struct sockaddr_in divsrc; - struct inpcb_iterator inpi = INP_ITERATOR(&V_divcbinfo, - INPLOOKUP_RLOCKPCB, div_port_match, &nport); struct m_tag *mtag; NET_EPOCH_ASSERT(); 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))) == NULL) return; /* 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) { ip = mtod(m, struct ip *); sctp_delayed_cksum(m, (uint32_t)(ip->ip_hl << 2)); m->m_pkthdr.csum_flags &= ~CSUM_SCTP; } #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 = ((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; 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 */ - sa = NULL; - /* nport is inp_next's context. */ - nport = htons((u_int16_t)(((struct ipfw_rule_ref *)(mtag+1))->info)); - while ((inp = inp_next(&inpi)) != NULL) { - sa = inp->inp_socket; + nport = htons((uint16_t)(((struct ipfw_rule_ref *)(mtag+1))->info)); + 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); - sa = NULL; /* force mbuf reclaim below */ + m_freem(m); } else { sorwakeup_locked(sa); DIVSTAT_INC(diverted); } - /* XXX why does only one socket match? */ - INP_RUNLOCK(inp); - break; - } - if (sa == NULL) { - m_freem(m); + } 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; 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) { case IPVERSION: family = AF_INET; break; #ifdef INET6 case IPV6_VERSION >> 4: family = AF_INET6; break; #endif default: m_freem(m); return (EAFNOSUPPORT); } /* 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; error = div_output_outbound(family, so, m); } else { dt->info |= IPFW_IS_DIVERT | IPFW_INFO_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) { struct ip *const ip = mtod(m, struct ip *); - struct mbuf *options; - struct inpcb *inp; int error; - inp = sotoinpcb(so); - INP_RLOCK(inp); switch (family) { case AF_INET: - /* - * 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)) { - INP_RUNLOCK(inp); + /* 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; #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)) { - INP_RUNLOCK(inp); m_freem(m); return (EINVAL); } break; } #endif } #ifdef MAC - mac_inpcb_create_mbuf(inp, m); + mac_socket_create_mbuf(so, 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. - */ - options = NULL; - if (inp->inp_options != NULL) { - options = m_dup(inp->inp_options, M_NOWAIT); - if (options == NULL) { - INP_RUNLOCK(inp); - m_freem(m); - return (ENOBUFS); - } - } - INP_RUNLOCK(inp); error = 0; switch (family) { case AF_INET: - error = ip_output(m, options, NULL, + error = ip_output(m, NULL, NULL, ((so->so_options & SO_DONTROUTE) ? IP_ROUTETOIF : 0) | IP_ALLOWBROADCAST | IP_RAWOUTPUT, NULL, NULL); break; #ifdef INET6 case AF_INET6: error = ip6_output(m, NULL, NULL, 0, NULL, NULL, NULL); break; #endif } if (error == 0) DIVSTAT_INC(outbound); - if (options != NULL) - m_freem(options); 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) { const struct ip *ip; 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) { case AF_INET: 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_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; #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 inpcb *inp; + struct divcb *dcb; 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; - error = in_pcballoc(so, &V_divcbinfo); - if (error) - return error; - inp = (struct inpcb *)so->so_pcb; - inp->inp_ip_p = proto; - inp->inp_flags |= INP_HDRINCL; - INP_WUNLOCK(inp); - return 0; + 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_detach(struct socket *so) +div_free(epoch_context_t ctx) { - struct inpcb *inp; + struct divcb *dcb = __containerof(ctx, struct divcb, dcb_epochctx); + + free(dcb, M_PCB); +} - inp = sotoinpcb(so); - KASSERT(inp != NULL, ("div_detach: inp == NULL")); - INP_WLOCK(inp); - in_pcbdetach(inp); - in_pcbfree(inp); +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 inpcb *inp; - int error; + struct divcb *dcb; + uint16_t port; - 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; if (nam->sa_len != sizeof(struct sockaddr_in)) return EINVAL; - ((struct sockaddr_in *)nam)->sin_addr.s_addr = INADDR_ANY; - INP_WLOCK(inp); - INP_HASH_WLOCK(&V_divcbinfo); - error = in_pcbbind(inp, nam, td->td_ucred); - INP_HASH_WUNLOCK(&V_divcbinfo); - INP_WUNLOCK(inp); - return error; + 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_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_pcblist(SYSCTL_HANDLER_ARGS) { - struct inpcb_iterator inpi = INP_ALL_ITERATOR(&V_divcbinfo, - INPLOOKUP_RLOCKPCB); struct xinpgen xig; - struct inpcb *inp; + struct divcb *dcb; int error; if (req->newptr != 0) return EPERM; if (req->oldptr == 0) { - int n; + u_int n; - n = V_divcbinfo.ipi_count; + 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_divcbinfo.ipi_count; - xig.xig_gen = V_divcbinfo.ipi_gencnt; + 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; - while ((inp = inp_next(&inpi)) != NULL) { - if (inp->inp_gencnt <= xig.xig_gen) { - struct xinpcb xi; - - in_pcbtoxinpcb(inp, &xi); - error = SYSCTL_OUT(req, &xi, sizeof xi); - if (error) { - INP_RUNLOCK(inp); - break; + 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; } } - } - 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. - */ - xig.xig_gen = V_divcbinfo.ipi_gencnt; - xig.xig_sogen = so_gencnt; - xig.xig_count = V_divcbinfo.ipi_count; - error = SYSCTL_OUT(req, &xig, sizeof xig); - } + /* + * 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_control = in_control, .pr_detach = div_detach, - .pr_peeraddr = in_getpeeraddr, .pr_send = div_send, .pr_shutdown = div_shutdown, - .pr_sockaddr = in_getsockaddr, - .pr_sosetlabel = in_pcbsosetlabel }; 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. */ - INP_INFO_WLOCK(&V_divcbinfo); - if (V_divcbinfo.ipi_count != 0) { + DIVERT_LOCK(); + if (V_dcb_count != 0) { + DIVERT_UNLOCK(); err = EBUSY; - INP_INFO_WUNLOCK(&V_divcbinfo); break; } + DIVERT_UNLOCK(); ip_divert_ptr = NULL; domain_remove(&divertdomain); - INP_INFO_WUNLOCK(&V_divcbinfo); -#ifndef VIMAGE - div_destroy(NULL); -#endif 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_DEPEND(ipdivert, ipfw, 3, 3, 3); MODULE_VERSION(ipdivert, 1);