The Design and Implementation of the FreeBSD Operating System, Second Edition
Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]

FreeBSD/Linux Kernel Cross Reference
sys/netinet/ip_divert.c

Version: -  FREEBSD  -  FREEBSD-13-STABLE  -  FREEBSD-13-0  -  FREEBSD-12-STABLE  -  FREEBSD-12-0  -  FREEBSD-11-STABLE  -  FREEBSD-11-0  -  FREEBSD-10-STABLE  -  FREEBSD-10-0  -  FREEBSD-9-STABLE  -  FREEBSD-9-0  -  FREEBSD-8-STABLE  -  FREEBSD-8-0  -  FREEBSD-7-STABLE  -  FREEBSD-7-0  -  FREEBSD-6-STABLE  -  FREEBSD-6-0  -  FREEBSD-5-STABLE  -  FREEBSD-5-0  -  FREEBSD-4-STABLE  -  FREEBSD-3-STABLE  -  FREEBSD22  -  l41  -  OPENBSD  -  linux-2.6  -  MK84  -  PLAN9  -  xnu-8792 
SearchContext: -  none  -  3  -  10 

    1 /*-
    2  * Copyright (c) 1982, 1986, 1988, 1993
    3  *      The Regents of the University of California.  All rights reserved.
    4  *
    5  * Redistribution and use in source and binary forms, with or without
    6  * modification, are permitted provided that the following conditions
    7  * are met:
    8  * 1. Redistributions of source code must retain the above copyright
    9  *    notice, this list of conditions and the following disclaimer.
   10  * 2. Redistributions in binary form must reproduce the above copyright
   11  *    notice, this list of conditions and the following disclaimer in the
   12  *    documentation and/or other materials provided with the distribution.
   13  * 4. Neither the name of the University nor the names of its contributors
   14  *    may be used to endorse or promote products derived from this software
   15  *    without specific prior written permission.
   16  *
   17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   27  * SUCH DAMAGE.
   28  */
   29 
   30 #include <sys/cdefs.h>
   31 __FBSDID("$FreeBSD: releng/9.1/sys/netinet/ip_divert.c 224575 2011-08-01 13:41:38Z glebius $");
   32 
   33 #if !defined(KLD_MODULE)
   34 #include "opt_inet.h"
   35 #include "opt_sctp.h"
   36 #ifndef INET
   37 #error "IPDIVERT requires INET."
   38 #endif
   39 #endif
   40 #include "opt_inet6.h"
   41 
   42 #include <sys/param.h>
   43 #include <sys/kernel.h>
   44 #include <sys/lock.h>
   45 #include <sys/malloc.h>
   46 #include <sys/mbuf.h>
   47 #include <sys/module.h>
   48 #include <sys/kernel.h>
   49 #include <sys/priv.h>
   50 #include <sys/proc.h>
   51 #include <sys/protosw.h>
   52 #include <sys/socket.h>
   53 #include <sys/socketvar.h>
   54 #include <sys/sysctl.h>
   55 #include <net/vnet.h>
   56 
   57 #include <net/if.h>
   58 #include <net/netisr.h> 
   59 
   60 #include <netinet/in.h>
   61 #include <netinet/in_pcb.h>
   62 #include <netinet/in_systm.h>
   63 #include <netinet/in_var.h>
   64 #include <netinet/ip.h>
   65 #include <netinet/ip_var.h>
   66 #ifdef INET6
   67 #include <netinet/ip6.h>
   68 #include <netinet6/ip6_var.h>
   69 #endif
   70 #ifdef SCTP
   71 #include <netinet/sctp_crc32.h>
   72 #endif
   73 
   74 #include <security/mac/mac_framework.h>
   75 
   76 /*
   77  * Divert sockets
   78  */
   79 
   80 /*
   81  * Allocate enough space to hold a full IP packet
   82  */
   83 #define DIVSNDQ         (65536 + 100)
   84 #define DIVRCVQ         (65536 + 100)
   85 
   86 /*
   87  * Divert sockets work in conjunction with ipfw or other packet filters,
   88  * see the divert(4) manpage for features.
   89  * Packets are selected by the packet filter and tagged with an
   90  * MTAG_IPFW_RULE tag carrying the 'divert port' number (as set by
   91  * the packet filter) and information on the matching filter rule for
   92  * subsequent reinjection. The divert_port is used to put the packet
   93  * on the corresponding divert socket, while the rule number is passed
   94  * up (at least partially) as the sin_port in the struct sockaddr.
   95  *
   96  * Packets written to the divert socket carry in sin_addr a
   97  * destination address, and in sin_port the number of the filter rule
   98  * after which to continue processing.
   99  * If the destination address is INADDR_ANY, the packet is treated as
  100  * as outgoing and sent to ip_output(); otherwise it is treated as
  101  * incoming and sent to ip_input().
  102  * Further, sin_zero carries some information on the interface,
  103  * which can be used in the reinject -- see comments in the code.
  104  *
  105  * On reinjection, processing in ip_input() and ip_output()
  106  * will be exactly the same as for the original packet, except that
  107  * packet filter processing will start at the rule number after the one
  108  * written in the sin_port (ipfw does not allow a rule #0, so sin_port=0
  109  * will apply the entire ruleset to the packet).
  110  */
  111 
  112 /* Internal variables. */
  113 static VNET_DEFINE(struct inpcbhead, divcb);
  114 static VNET_DEFINE(struct inpcbinfo, divcbinfo);
  115 
  116 #define V_divcb                         VNET(divcb)
  117 #define V_divcbinfo                     VNET(divcbinfo)
  118 
  119 static u_long   div_sendspace = DIVSNDQ;        /* XXX sysctl ? */
  120 static u_long   div_recvspace = DIVRCVQ;        /* XXX sysctl ? */
  121 
  122 static eventhandler_tag ip_divert_event_tag;
  123 
  124 /*
  125  * Initialize divert connection block queue.
  126  */
  127 static void
  128 div_zone_change(void *tag)
  129 {
  130 
  131         uma_zone_set_max(V_divcbinfo.ipi_zone, maxsockets);
  132 }
  133 
  134 static int
  135 div_inpcb_init(void *mem, int size, int flags)
  136 {
  137         struct inpcb *inp = mem;
  138 
  139         INP_LOCK_INIT(inp, "inp", "divinp");
  140         return (0);
  141 }
  142 
  143 static void
  144 div_inpcb_fini(void *mem, int size)
  145 {
  146         struct inpcb *inp = mem;
  147 
  148         INP_LOCK_DESTROY(inp);
  149 }
  150 
  151 static void
  152 div_init(void)
  153 {
  154 
  155         /*
  156          * XXX We don't use the hash list for divert IP, but it's easier to
  157          * allocate one-entry hash lists than it is to check all over the
  158          * place for hashbase == NULL.
  159          */
  160         in_pcbinfo_init(&V_divcbinfo, "div", &V_divcb, 1, 1, "divcb",
  161             div_inpcb_init, div_inpcb_fini, UMA_ZONE_NOFREE,
  162             IPI_HASHFIELDS_NONE);
  163 }
  164 
  165 static void
  166 div_destroy(void)
  167 {
  168 
  169         in_pcbinfo_destroy(&V_divcbinfo);
  170 }
  171 
  172 /*
  173  * IPPROTO_DIVERT is not in the real IP protocol number space; this
  174  * function should never be called.  Just in case, drop any packets.
  175  */
  176 static void
  177 div_input(struct mbuf *m, int off)
  178 {
  179 
  180         KMOD_IPSTAT_INC(ips_noproto);
  181         m_freem(m);
  182 }
  183 
  184 /*
  185  * Divert a packet by passing it up to the divert socket at port 'port'.
  186  *
  187  * Setup generic address and protocol structures for div_input routine,
  188  * then pass them along with mbuf chain.
  189  */
  190 static void
  191 divert_packet(struct mbuf *m, int incoming)
  192 {
  193         struct ip *ip;
  194         struct inpcb *inp;
  195         struct socket *sa;
  196         u_int16_t nport;
  197         struct sockaddr_in divsrc;
  198         struct m_tag *mtag;
  199 
  200         mtag = m_tag_locate(m, MTAG_IPFW_RULE, 0, NULL);
  201         if (mtag == NULL) {
  202                 m_freem(m);
  203                 return;
  204         }
  205         /* Assure header */
  206         if (m->m_len < sizeof(struct ip) &&
  207             (m = m_pullup(m, sizeof(struct ip))) == 0)
  208                 return;
  209         ip = mtod(m, struct ip *);
  210 
  211         /* Delayed checksums are currently not compatible with divert. */
  212         if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
  213                 ip->ip_len = ntohs(ip->ip_len);
  214                 in_delayed_cksum(m);
  215                 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
  216                 ip->ip_len = htons(ip->ip_len);
  217         }
  218 #ifdef SCTP
  219         if (m->m_pkthdr.csum_flags & CSUM_SCTP) {
  220                 ip->ip_len = ntohs(ip->ip_len);
  221                 sctp_delayed_cksum(m, (uint32_t)(ip->ip_hl << 2));
  222                 m->m_pkthdr.csum_flags &= ~CSUM_SCTP;
  223                 ip->ip_len = htons(ip->ip_len);
  224         }
  225 #endif
  226         bzero(&divsrc, sizeof(divsrc));
  227         divsrc.sin_len = sizeof(divsrc);
  228         divsrc.sin_family = AF_INET;
  229         /* record matching rule, in host format */
  230         divsrc.sin_port = ((struct ipfw_rule_ref *)(mtag+1))->rulenum;
  231         /*
  232          * Record receive interface address, if any.
  233          * But only for incoming packets.
  234          */
  235         if (incoming) {
  236                 struct ifaddr *ifa;
  237                 struct ifnet *ifp;
  238 
  239                 /* Sanity check */
  240                 M_ASSERTPKTHDR(m);
  241 
  242                 /* Find IP address for receive interface */
  243                 ifp = m->m_pkthdr.rcvif;
  244                 if_addr_rlock(ifp);
  245                 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
  246                         if (ifa->ifa_addr->sa_family != AF_INET)
  247                                 continue;
  248                         divsrc.sin_addr =
  249                             ((struct sockaddr_in *) ifa->ifa_addr)->sin_addr;
  250                         break;
  251                 }
  252                 if_addr_runlock(ifp);
  253         }
  254         /*
  255          * Record the incoming interface name whenever we have one.
  256          */
  257         if (m->m_pkthdr.rcvif) {
  258                 /*
  259                  * Hide the actual interface name in there in the 
  260                  * sin_zero array. XXX This needs to be moved to a
  261                  * different sockaddr type for divert, e.g.
  262                  * sockaddr_div with multiple fields like 
  263                  * sockaddr_dl. Presently we have only 7 bytes
  264                  * but that will do for now as most interfaces
  265                  * are 4 or less + 2 or less bytes for unit.
  266                  * There is probably a faster way of doing this,
  267                  * possibly taking it from the sockaddr_dl on the iface.
  268                  * This solves the problem of a P2P link and a LAN interface
  269                  * having the same address, which can result in the wrong
  270                  * interface being assigned to the packet when fed back
  271                  * into the divert socket. Theoretically if the daemon saves
  272                  * and re-uses the sockaddr_in as suggested in the man pages,
  273                  * this iface name will come along for the ride.
  274                  * (see div_output for the other half of this.)
  275                  */ 
  276                 strlcpy(divsrc.sin_zero, m->m_pkthdr.rcvif->if_xname,
  277                     sizeof(divsrc.sin_zero));
  278         }
  279 
  280         /* Put packet on socket queue, if any */
  281         sa = NULL;
  282         nport = htons((u_int16_t)(((struct ipfw_rule_ref *)(mtag+1))->info));
  283         INP_INFO_RLOCK(&V_divcbinfo);
  284         LIST_FOREACH(inp, &V_divcb, inp_list) {
  285                 /* XXX why does only one socket match? */
  286                 if (inp->inp_lport == nport) {
  287                         INP_RLOCK(inp);
  288                         sa = inp->inp_socket;
  289                         SOCKBUF_LOCK(&sa->so_rcv);
  290                         if (sbappendaddr_locked(&sa->so_rcv,
  291                             (struct sockaddr *)&divsrc, m,
  292                             (struct mbuf *)0) == 0) {
  293                                 SOCKBUF_UNLOCK(&sa->so_rcv);
  294                                 sa = NULL;      /* force mbuf reclaim below */
  295                         } else
  296                                 sorwakeup_locked(sa);
  297                         INP_RUNLOCK(inp);
  298                         break;
  299                 }
  300         }
  301         INP_INFO_RUNLOCK(&V_divcbinfo);
  302         if (sa == NULL) {
  303                 m_freem(m);
  304                 KMOD_IPSTAT_INC(ips_noproto);
  305                 KMOD_IPSTAT_DEC(ips_delivered);
  306         }
  307 }
  308 
  309 /*
  310  * Deliver packet back into the IP processing machinery.
  311  *
  312  * If no address specified, or address is 0.0.0.0, send to ip_output();
  313  * otherwise, send to ip_input() and mark as having been received on
  314  * the interface with that address.
  315  */
  316 static int
  317 div_output(struct socket *so, struct mbuf *m, struct sockaddr_in *sin,
  318     struct mbuf *control)
  319 {
  320         struct ip *const ip = mtod(m, struct ip *);
  321         struct m_tag *mtag;
  322         struct ipfw_rule_ref *dt;
  323         int error = 0;
  324 
  325         /*
  326          * An mbuf may hasn't come from userland, but we pretend
  327          * that it has.
  328          */
  329         m->m_pkthdr.rcvif = NULL;
  330         m->m_nextpkt = NULL;
  331         M_SETFIB(m, so->so_fibnum);
  332 
  333         if (control)
  334                 m_freem(control);               /* XXX */
  335 
  336         mtag = m_tag_locate(m, MTAG_IPFW_RULE, 0, NULL);
  337         if (mtag == NULL) {
  338                 /* this should be normal */
  339                 mtag = m_tag_alloc(MTAG_IPFW_RULE, 0,
  340                     sizeof(struct ipfw_rule_ref), M_NOWAIT | M_ZERO);
  341                 if (mtag == NULL) {
  342                         error = ENOBUFS;
  343                         goto cantsend;
  344                 }
  345                 m_tag_prepend(m, mtag);
  346         }
  347         dt = (struct ipfw_rule_ref *)(mtag+1);
  348 
  349         /* Loopback avoidance and state recovery */
  350         if (sin) {
  351                 int i;
  352 
  353                 /* set the starting point. We provide a non-zero slot,
  354                  * but a non_matching chain_id to skip that info and use
  355                  * the rulenum/rule_id.
  356                  */
  357                 dt->slot = 1; /* dummy, chain_id is invalid */
  358                 dt->chain_id = 0;
  359                 dt->rulenum = sin->sin_port+1; /* host format ? */
  360                 dt->rule_id = 0;
  361                 /*
  362                  * Find receive interface with the given name, stuffed
  363                  * (if it exists) in the sin_zero[] field.
  364                  * The name is user supplied data so don't trust its size
  365                  * or that it is zero terminated.
  366                  */
  367                 for (i = 0; i < sizeof(sin->sin_zero) && sin->sin_zero[i]; i++)
  368                         ;
  369                 if ( i > 0 && i < sizeof(sin->sin_zero))
  370                         m->m_pkthdr.rcvif = ifunit(sin->sin_zero);
  371         }
  372 
  373         /* Reinject packet into the system as incoming or outgoing */
  374         if (!sin || sin->sin_addr.s_addr == 0) {
  375                 struct mbuf *options = NULL;
  376                 struct inpcb *inp;
  377 
  378                 dt->info |= IPFW_IS_DIVERT | IPFW_INFO_OUT;
  379                 inp = sotoinpcb(so);
  380                 INP_RLOCK(inp);
  381                 switch (ip->ip_v) {
  382                 case IPVERSION:
  383                         /*
  384                          * Don't allow both user specified and setsockopt
  385                          * options, and don't allow packet length sizes that
  386                          * will crash.
  387                          */
  388                         if ((((ip->ip_hl << 2) != sizeof(struct ip)) &&
  389                             inp->inp_options != NULL) ||
  390                             ((u_short)ntohs(ip->ip_len) > m->m_pkthdr.len)) {
  391                                 error = EINVAL;
  392                                 INP_RUNLOCK(inp);
  393                                 goto cantsend;
  394                         }
  395 
  396                         /* Convert fields to host order for ip_output() */
  397                         ip->ip_len = ntohs(ip->ip_len);
  398                         ip->ip_off = ntohs(ip->ip_off);
  399                         break;
  400 #ifdef INET6
  401                 case IPV6_VERSION >> 4:
  402                     {
  403                         struct ip6_hdr *const ip6 = mtod(m, struct ip6_hdr *);
  404 
  405                         /* Don't allow packet length sizes that will crash */
  406                         if (((u_short)ntohs(ip6->ip6_plen) > m->m_pkthdr.len)) {
  407                                 error = EINVAL;
  408                                 INP_RUNLOCK(inp);
  409                                 goto cantsend;
  410                         }
  411 
  412                         ip6->ip6_plen = ntohs(ip6->ip6_plen);
  413                         break;
  414                     }
  415 #endif
  416                 default:
  417                         error = EINVAL;
  418                         INP_RUNLOCK(inp);
  419                         goto cantsend;
  420                 }
  421 
  422                 /* Send packet to output processing */
  423                 KMOD_IPSTAT_INC(ips_rawout);            /* XXX */
  424 
  425 #ifdef MAC
  426                 mac_inpcb_create_mbuf(inp, m);
  427 #endif
  428                 /*
  429                  * Get ready to inject the packet into ip_output().
  430                  * Just in case socket options were specified on the
  431                  * divert socket, we duplicate them.  This is done
  432                  * to avoid having to hold the PCB locks over the call
  433                  * to ip_output(), as doing this results in a number of
  434                  * lock ordering complexities.
  435                  *
  436                  * Note that we set the multicast options argument for
  437                  * ip_output() to NULL since it should be invariant that
  438                  * they are not present.
  439                  */
  440                 KASSERT(inp->inp_moptions == NULL,
  441                     ("multicast options set on a divert socket"));
  442                 /*
  443                  * XXXCSJP: It is unclear to me whether or not it makes
  444                  * sense for divert sockets to have options.  However,
  445                  * for now we will duplicate them with the INP locks
  446                  * held so we can use them in ip_output() without
  447                  * requring a reference to the pcb.
  448                  */
  449                 if (inp->inp_options != NULL) {
  450                         options = m_dup(inp->inp_options, M_NOWAIT);
  451                         if (options == NULL) {
  452                                 INP_RUNLOCK(inp);
  453                                 error = ENOBUFS;
  454                                 goto cantsend;
  455                         }
  456                 }
  457                 INP_RUNLOCK(inp);
  458 
  459                 switch (ip->ip_v) {
  460                 case IPVERSION:
  461                         error = ip_output(m, options, NULL,
  462                             ((so->so_options & SO_DONTROUTE) ? IP_ROUTETOIF : 0)
  463                             | IP_ALLOWBROADCAST | IP_RAWOUTPUT, NULL, NULL);
  464                         break;
  465 #ifdef INET6
  466                 case IPV6_VERSION >> 4:
  467                         error = ip6_output(m, NULL, NULL, 0, NULL, NULL, NULL);
  468                         break;
  469 #endif
  470                 }
  471                 if (options != NULL)
  472                         m_freem(options);
  473         } else {
  474                 dt->info |= IPFW_IS_DIVERT | IPFW_INFO_IN;
  475                 if (m->m_pkthdr.rcvif == NULL) {
  476                         /*
  477                          * No luck with the name, check by IP address.
  478                          * Clear the port and the ifname to make sure
  479                          * there are no distractions for ifa_ifwithaddr.
  480                          */
  481                         struct  ifaddr *ifa;
  482 
  483                         bzero(sin->sin_zero, sizeof(sin->sin_zero));
  484                         sin->sin_port = 0;
  485                         ifa = ifa_ifwithaddr((struct sockaddr *) sin);
  486                         if (ifa == NULL) {
  487                                 error = EADDRNOTAVAIL;
  488                                 goto cantsend;
  489                         }
  490                         m->m_pkthdr.rcvif = ifa->ifa_ifp;
  491                         ifa_free(ifa);
  492                 }
  493 #ifdef MAC
  494                 mac_socket_create_mbuf(so, m);
  495 #endif
  496                 /* Send packet to input processing via netisr */
  497                 switch (ip->ip_v) {
  498                 case IPVERSION:
  499                         netisr_queue_src(NETISR_IP, (uintptr_t)so, m);
  500                         break;
  501 #ifdef INET6
  502                 case IPV6_VERSION >> 4:
  503                         netisr_queue_src(NETISR_IPV6, (uintptr_t)so, m);
  504                         break;
  505 #endif
  506                 default:
  507                         error = EINVAL;
  508                         goto cantsend;
  509                 }
  510         }
  511 
  512         return (error);
  513 
  514 cantsend:
  515         m_freem(m);
  516         return (error);
  517 }
  518 
  519 static int
  520 div_attach(struct socket *so, int proto, struct thread *td)
  521 {
  522         struct inpcb *inp;
  523         int error;
  524 
  525         inp  = sotoinpcb(so);
  526         KASSERT(inp == NULL, ("div_attach: inp != NULL"));
  527         if (td != NULL) {
  528                 error = priv_check(td, PRIV_NETINET_DIVERT);
  529                 if (error)
  530                         return (error);
  531         }
  532         error = soreserve(so, div_sendspace, div_recvspace);
  533         if (error)
  534                 return error;
  535         INP_INFO_WLOCK(&V_divcbinfo);
  536         error = in_pcballoc(so, &V_divcbinfo);
  537         if (error) {
  538                 INP_INFO_WUNLOCK(&V_divcbinfo);
  539                 return error;
  540         }
  541         inp = (struct inpcb *)so->so_pcb;
  542         INP_INFO_WUNLOCK(&V_divcbinfo);
  543         inp->inp_ip_p = proto;
  544         inp->inp_vflag |= INP_IPV4;
  545         inp->inp_flags |= INP_HDRINCL;
  546         INP_WUNLOCK(inp);
  547         return 0;
  548 }
  549 
  550 static void
  551 div_detach(struct socket *so)
  552 {
  553         struct inpcb *inp;
  554 
  555         inp = sotoinpcb(so);
  556         KASSERT(inp != NULL, ("div_detach: inp == NULL"));
  557         INP_INFO_WLOCK(&V_divcbinfo);
  558         INP_WLOCK(inp);
  559         in_pcbdetach(inp);
  560         in_pcbfree(inp);
  561         INP_INFO_WUNLOCK(&V_divcbinfo);
  562 }
  563 
  564 static int
  565 div_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
  566 {
  567         struct inpcb *inp;
  568         int error;
  569 
  570         inp = sotoinpcb(so);
  571         KASSERT(inp != NULL, ("div_bind: inp == NULL"));
  572         /* in_pcbbind assumes that nam is a sockaddr_in
  573          * and in_pcbbind requires a valid address. Since divert
  574          * sockets don't we need to make sure the address is
  575          * filled in properly.
  576          * XXX -- divert should not be abusing in_pcbind
  577          * and should probably have its own family.
  578          */
  579         if (nam->sa_family != AF_INET)
  580                 return EAFNOSUPPORT;
  581         ((struct sockaddr_in *)nam)->sin_addr.s_addr = INADDR_ANY;
  582         INP_INFO_WLOCK(&V_divcbinfo);
  583         INP_WLOCK(inp);
  584         INP_HASH_WLOCK(&V_divcbinfo);
  585         error = in_pcbbind(inp, nam, td->td_ucred);
  586         INP_HASH_WUNLOCK(&V_divcbinfo);
  587         INP_WUNLOCK(inp);
  588         INP_INFO_WUNLOCK(&V_divcbinfo);
  589         return error;
  590 }
  591 
  592 static int
  593 div_shutdown(struct socket *so)
  594 {
  595         struct inpcb *inp;
  596 
  597         inp = sotoinpcb(so);
  598         KASSERT(inp != NULL, ("div_shutdown: inp == NULL"));
  599         INP_WLOCK(inp);
  600         socantsendmore(so);
  601         INP_WUNLOCK(inp);
  602         return 0;
  603 }
  604 
  605 static int
  606 div_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam,
  607     struct mbuf *control, struct thread *td)
  608 {
  609 
  610         /* Packet must have a header (but that's about it) */
  611         if (m->m_len < sizeof (struct ip) &&
  612             (m = m_pullup(m, sizeof (struct ip))) == 0) {
  613                 KMOD_IPSTAT_INC(ips_toosmall);
  614                 m_freem(m);
  615                 return EINVAL;
  616         }
  617 
  618         /* Send packet */
  619         return div_output(so, m, (struct sockaddr_in *)nam, control);
  620 }
  621 
  622 static void
  623 div_ctlinput(int cmd, struct sockaddr *sa, void *vip)
  624 {
  625         struct in_addr faddr;
  626 
  627         faddr = ((struct sockaddr_in *)sa)->sin_addr;
  628         if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY)
  629                 return;
  630         if (PRC_IS_REDIRECT(cmd))
  631                 return;
  632 }
  633 
  634 static int
  635 div_pcblist(SYSCTL_HANDLER_ARGS)
  636 {
  637         int error, i, n;
  638         struct inpcb *inp, **inp_list;
  639         inp_gen_t gencnt;
  640         struct xinpgen xig;
  641 
  642         /*
  643          * The process of preparing the TCB list is too time-consuming and
  644          * resource-intensive to repeat twice on every request.
  645          */
  646         if (req->oldptr == 0) {
  647                 n = V_divcbinfo.ipi_count;
  648                 n += imax(n / 8, 10);
  649                 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xinpcb);
  650                 return 0;
  651         }
  652 
  653         if (req->newptr != 0)
  654                 return EPERM;
  655 
  656         /*
  657          * OK, now we're committed to doing something.
  658          */
  659         INP_INFO_RLOCK(&V_divcbinfo);
  660         gencnt = V_divcbinfo.ipi_gencnt;
  661         n = V_divcbinfo.ipi_count;
  662         INP_INFO_RUNLOCK(&V_divcbinfo);
  663 
  664         error = sysctl_wire_old_buffer(req,
  665             2 * sizeof(xig) + n*sizeof(struct xinpcb));
  666         if (error != 0)
  667                 return (error);
  668 
  669         xig.xig_len = sizeof xig;
  670         xig.xig_count = n;
  671         xig.xig_gen = gencnt;
  672         xig.xig_sogen = so_gencnt;
  673         error = SYSCTL_OUT(req, &xig, sizeof xig);
  674         if (error)
  675                 return error;
  676 
  677         inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK);
  678         if (inp_list == 0)
  679                 return ENOMEM;
  680         
  681         INP_INFO_RLOCK(&V_divcbinfo);
  682         for (inp = LIST_FIRST(V_divcbinfo.ipi_listhead), i = 0; inp && i < n;
  683              inp = LIST_NEXT(inp, inp_list)) {
  684                 INP_WLOCK(inp);
  685                 if (inp->inp_gencnt <= gencnt &&
  686                     cr_canseeinpcb(req->td->td_ucred, inp) == 0) {
  687                         in_pcbref(inp);
  688                         inp_list[i++] = inp;
  689                 }
  690                 INP_WUNLOCK(inp);
  691         }
  692         INP_INFO_RUNLOCK(&V_divcbinfo);
  693         n = i;
  694 
  695         error = 0;
  696         for (i = 0; i < n; i++) {
  697                 inp = inp_list[i];
  698                 INP_RLOCK(inp);
  699                 if (inp->inp_gencnt <= gencnt) {
  700                         struct xinpcb xi;
  701                         bzero(&xi, sizeof(xi));
  702                         xi.xi_len = sizeof xi;
  703                         /* XXX should avoid extra copy */
  704                         bcopy(inp, &xi.xi_inp, sizeof *inp);
  705                         if (inp->inp_socket)
  706                                 sotoxsocket(inp->inp_socket, &xi.xi_socket);
  707                         INP_RUNLOCK(inp);
  708                         error = SYSCTL_OUT(req, &xi, sizeof xi);
  709                 } else
  710                         INP_RUNLOCK(inp);
  711         }
  712         INP_INFO_WLOCK(&V_divcbinfo);
  713         for (i = 0; i < n; i++) {
  714                 inp = inp_list[i];
  715                 INP_RLOCK(inp);
  716                 if (!in_pcbrele_rlocked(inp))
  717                         INP_RUNLOCK(inp);
  718         }
  719         INP_INFO_WUNLOCK(&V_divcbinfo);
  720 
  721         if (!error) {
  722                 /*
  723                  * Give the user an updated idea of our state.
  724                  * If the generation differs from what we told
  725                  * her before, she knows that something happened
  726                  * while we were processing this request, and it
  727                  * might be necessary to retry.
  728                  */
  729                 INP_INFO_RLOCK(&V_divcbinfo);
  730                 xig.xig_gen = V_divcbinfo.ipi_gencnt;
  731                 xig.xig_sogen = so_gencnt;
  732                 xig.xig_count = V_divcbinfo.ipi_count;
  733                 INP_INFO_RUNLOCK(&V_divcbinfo);
  734                 error = SYSCTL_OUT(req, &xig, sizeof xig);
  735         }
  736         free(inp_list, M_TEMP);
  737         return error;
  738 }
  739 
  740 #ifdef SYSCTL_NODE
  741 SYSCTL_NODE(_net_inet, IPPROTO_DIVERT, divert, CTLFLAG_RW, 0, "IPDIVERT");
  742 SYSCTL_PROC(_net_inet_divert, OID_AUTO, pcblist, CTLTYPE_OPAQUE | CTLFLAG_RD,
  743     NULL, 0, div_pcblist, "S,xinpcb", "List of active divert sockets");
  744 #endif
  745 
  746 struct pr_usrreqs div_usrreqs = {
  747         .pru_attach =           div_attach,
  748         .pru_bind =             div_bind,
  749         .pru_control =          in_control,
  750         .pru_detach =           div_detach,
  751         .pru_peeraddr =         in_getpeeraddr,
  752         .pru_send =             div_send,
  753         .pru_shutdown =         div_shutdown,
  754         .pru_sockaddr =         in_getsockaddr,
  755         .pru_sosetlabel =       in_pcbsosetlabel
  756 };
  757 
  758 struct protosw div_protosw = {
  759         .pr_type =              SOCK_RAW,
  760         .pr_protocol =          IPPROTO_DIVERT,
  761         .pr_flags =             PR_ATOMIC|PR_ADDR,
  762         .pr_input =             div_input,
  763         .pr_ctlinput =          div_ctlinput,
  764         .pr_ctloutput =         ip_ctloutput,
  765         .pr_init =              div_init,
  766 #ifdef VIMAGE
  767         .pr_destroy =           div_destroy,
  768 #endif
  769         .pr_usrreqs =           &div_usrreqs
  770 };
  771 
  772 static int
  773 div_modevent(module_t mod, int type, void *unused)
  774 {
  775         int err = 0;
  776 #ifndef VIMAGE
  777         int n;
  778 #endif
  779 
  780         switch (type) {
  781         case MOD_LOAD:
  782                 /*
  783                  * Protocol will be initialized by pf_proto_register().
  784                  * We don't have to register ip_protox because we are not
  785                  * a true IP protocol that goes over the wire.
  786                  */
  787                 err = pf_proto_register(PF_INET, &div_protosw);
  788                 if (err != 0)
  789                         return (err);
  790                 ip_divert_ptr = divert_packet;
  791                 ip_divert_event_tag = EVENTHANDLER_REGISTER(maxsockets_change,
  792                     div_zone_change, NULL, EVENTHANDLER_PRI_ANY);
  793                 break;
  794         case MOD_QUIESCE:
  795                 /*
  796                  * IPDIVERT may normally not be unloaded because of the
  797                  * potential race conditions.  Tell kldunload we can't be
  798                  * unloaded unless the unload is forced.
  799                  */
  800                 err = EPERM;
  801                 break;
  802         case MOD_UNLOAD:
  803 #ifdef VIMAGE
  804                 err = EPERM;
  805                 break;
  806 #else
  807                 /*
  808                  * Forced unload.
  809                  *
  810                  * Module ipdivert can only be unloaded if no sockets are
  811                  * connected.  Maybe this can be changed later to forcefully
  812                  * disconnect any open sockets.
  813                  *
  814                  * XXXRW: Note that there is a slight race here, as a new
  815                  * socket open request could be spinning on the lock and then
  816                  * we destroy the lock.
  817                  */
  818                 INP_INFO_WLOCK(&V_divcbinfo);
  819                 n = V_divcbinfo.ipi_count;
  820                 if (n != 0) {
  821                         err = EBUSY;
  822                         INP_INFO_WUNLOCK(&V_divcbinfo);
  823                         break;
  824                 }
  825                 ip_divert_ptr = NULL;
  826                 err = pf_proto_unregister(PF_INET, IPPROTO_DIVERT, SOCK_RAW);
  827                 INP_INFO_WUNLOCK(&V_divcbinfo);
  828                 div_destroy();
  829                 EVENTHANDLER_DEREGISTER(maxsockets_change, ip_divert_event_tag);
  830                 break;
  831 #endif /* !VIMAGE */
  832         default:
  833                 err = EOPNOTSUPP;
  834                 break;
  835         }
  836         return err;
  837 }
  838 
  839 static moduledata_t ipdivertmod = {
  840         "ipdivert",
  841         div_modevent,
  842         0
  843 };
  844 
  845 DECLARE_MODULE(ipdivert, ipdivertmod, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY);
  846 MODULE_DEPEND(ipdivert, ipfw, 2, 2, 2);
  847 MODULE_VERSION(ipdivert, 1);

Cache object: a4487fea448d2437f051c26b9622a488


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]


This page is part of the FreeBSD/Linux Linux Kernel Cross-Reference, and was automatically generated using a modified version of the LXR engine.