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_output.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, 1990, 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  *      @(#)ip_output.c 8.3 (Berkeley) 1/21/94
   30  */
   31 
   32 #include <sys/cdefs.h>
   33 __FBSDID("$FreeBSD: releng/9.2/sys/netinet/ip_output.c 253281 2013-07-12 18:54:47Z trociny $");
   34 
   35 #include "opt_ipfw.h"
   36 #include "opt_ipsec.h"
   37 #include "opt_route.h"
   38 #include "opt_mbuf_stress_test.h"
   39 #include "opt_mpath.h"
   40 #include "opt_sctp.h"
   41 
   42 #include <sys/param.h>
   43 #include <sys/systm.h>
   44 #include <sys/kernel.h>
   45 #include <sys/malloc.h>
   46 #include <sys/mbuf.h>
   47 #include <sys/priv.h>
   48 #include <sys/proc.h>
   49 #include <sys/protosw.h>
   50 #include <sys/socket.h>
   51 #include <sys/socketvar.h>
   52 #include <sys/sysctl.h>
   53 #include <sys/ucred.h>
   54 
   55 #include <net/if.h>
   56 #include <net/if_llatbl.h>
   57 #include <net/netisr.h>
   58 #include <net/pfil.h>
   59 #include <net/route.h>
   60 #include <net/flowtable.h>
   61 #ifdef RADIX_MPATH
   62 #include <net/radix_mpath.h>
   63 #endif
   64 #include <net/vnet.h>
   65 
   66 #include <netinet/in.h>
   67 #include <netinet/in_systm.h>
   68 #include <netinet/ip.h>
   69 #include <netinet/in_pcb.h>
   70 #include <netinet/in_var.h>
   71 #include <netinet/ip_var.h>
   72 #include <netinet/ip_options.h>
   73 #ifdef SCTP
   74 #include <netinet/sctp.h>
   75 #include <netinet/sctp_crc32.h>
   76 #endif
   77 
   78 #ifdef IPSEC
   79 #include <netinet/ip_ipsec.h>
   80 #include <netipsec/ipsec.h>
   81 #endif /* IPSEC*/
   82 
   83 #include <machine/in_cksum.h>
   84 
   85 #include <security/mac/mac_framework.h>
   86 
   87 VNET_DEFINE(u_short, ip_id);
   88 
   89 #ifdef MBUF_STRESS_TEST
   90 static int mbuf_frag_size = 0;
   91 SYSCTL_INT(_net_inet_ip, OID_AUTO, mbuf_frag_size, CTLFLAG_RW,
   92         &mbuf_frag_size, 0, "Fragment outgoing mbufs to this size");
   93 #endif
   94 
   95 static void     ip_mloopback
   96         (struct ifnet *, struct mbuf *, struct sockaddr_in *, int);
   97 
   98 
   99 extern int in_mcast_loop;
  100 extern  struct protosw inetsw[];
  101 
  102 /*
  103  * IP output.  The packet in mbuf chain m contains a skeletal IP
  104  * header (with len, off, ttl, proto, tos, src, dst).
  105  * ip_len and ip_off are in host format.
  106  * The mbuf chain containing the packet will be freed.
  107  * The mbuf opt, if present, will not be freed.
  108  * If route ro is present and has ro_rt initialized, route lookup would be
  109  * skipped and ro->ro_rt would be used. If ro is present but ro->ro_rt is NULL,
  110  * then result of route lookup is stored in ro->ro_rt.
  111  *
  112  * In the IP forwarding case, the packet will arrive with options already
  113  * inserted, so must have a NULL opt pointer.
  114  */
  115 int
  116 ip_output(struct mbuf *m, struct mbuf *opt, struct route *ro, int flags,
  117     struct ip_moptions *imo, struct inpcb *inp)
  118 {
  119         struct ip *ip;
  120         struct ifnet *ifp = NULL;       /* keep compiler happy */
  121         struct mbuf *m0;
  122         int hlen = sizeof (struct ip);
  123         int mtu;
  124         int n;  /* scratchpad */
  125         int error = 0;
  126         struct sockaddr_in *dst;
  127         struct in_ifaddr *ia;
  128         int isbroadcast, sw_csum;
  129         struct route iproute;
  130         struct rtentry *rte;    /* cache for ro->ro_rt */
  131         struct in_addr odst;
  132         struct m_tag *fwd_tag = NULL;
  133 #ifdef IPSEC
  134         int no_route_but_check_spd = 0;
  135 #endif
  136         M_ASSERTPKTHDR(m);
  137 
  138         if (inp != NULL) {
  139                 INP_LOCK_ASSERT(inp);
  140                 M_SETFIB(m, inp->inp_inc.inc_fibnum);
  141                 if (inp->inp_flags & (INP_HW_FLOWID|INP_SW_FLOWID)) {
  142                         m->m_pkthdr.flowid = inp->inp_flowid;
  143                         m->m_flags |= M_FLOWID;
  144                 }
  145         }
  146 
  147         if (ro == NULL) {
  148                 ro = &iproute;
  149                 bzero(ro, sizeof (*ro));
  150         }
  151 
  152 #ifdef FLOWTABLE
  153         if (ro->ro_rt == NULL) {
  154                 struct flentry *fle;
  155                         
  156                 /*
  157                  * The flow table returns route entries valid for up to 30
  158                  * seconds; we rely on the remainder of ip_output() taking no
  159                  * longer than that long for the stability of ro_rt. The
  160                  * flow ID assignment must have happened before this point.
  161                  */
  162                 fle = flowtable_lookup_mbuf(V_ip_ft, m, AF_INET);
  163                 if (fle != NULL)
  164                         flow_to_route(fle, ro);
  165         }
  166 #endif
  167 
  168         if (opt) {
  169                 int len = 0;
  170                 m = ip_insertoptions(m, opt, &len);
  171                 if (len != 0)
  172                         hlen = len; /* ip->ip_hl is updated above */
  173         }
  174         ip = mtod(m, struct ip *);
  175 
  176         /*
  177          * Fill in IP header.  If we are not allowing fragmentation,
  178          * then the ip_id field is meaningless, but we don't set it
  179          * to zero.  Doing so causes various problems when devices along
  180          * the path (routers, load balancers, firewalls, etc.) illegally
  181          * disable DF on our packet.  Note that a 16-bit counter
  182          * will wrap around in less than 10 seconds at 100 Mbit/s on a
  183          * medium with MTU 1500.  See Steven M. Bellovin, "A Technique
  184          * for Counting NATted Hosts", Proc. IMW'02, available at
  185          * <http://www.cs.columbia.edu/~smb/papers/fnat.pdf>.
  186          */
  187         if ((flags & (IP_FORWARDING|IP_RAWOUTPUT)) == 0) {
  188                 ip->ip_v = IPVERSION;
  189                 ip->ip_hl = hlen >> 2;
  190                 ip->ip_id = ip_newid();
  191                 IPSTAT_INC(ips_localout);
  192         } else {
  193                 /* Header already set, fetch hlen from there */
  194                 hlen = ip->ip_hl << 2;
  195         }
  196 
  197 again:
  198         dst = (struct sockaddr_in *)&ro->ro_dst;
  199         ia = NULL;
  200         /*
  201          * If there is a cached route,
  202          * check that it is to the same destination
  203          * and is still up.  If not, free it and try again.
  204          * The address family should also be checked in case of sharing the
  205          * cache with IPv6.
  206          */
  207         rte = ro->ro_rt;
  208         if (rte && ((rte->rt_flags & RTF_UP) == 0 ||
  209                     rte->rt_ifp == NULL ||
  210                     !RT_LINK_IS_UP(rte->rt_ifp) ||
  211                           dst->sin_family != AF_INET ||
  212                           dst->sin_addr.s_addr != ip->ip_dst.s_addr)) {
  213                 RO_RTFREE(ro);
  214                 ro->ro_lle = NULL;
  215                 rte = NULL;
  216         }
  217         if (rte == NULL && fwd_tag == NULL) {
  218                 bzero(dst, sizeof(*dst));
  219                 dst->sin_family = AF_INET;
  220                 dst->sin_len = sizeof(*dst);
  221                 dst->sin_addr = ip->ip_dst;
  222         }
  223         /*
  224          * If routing to interface only, short circuit routing lookup.
  225          * The use of an all-ones broadcast address implies this; an
  226          * interface is specified by the broadcast address of an interface,
  227          * or the destination address of a ptp interface.
  228          */
  229         if (flags & IP_SENDONES) {
  230                 if ((ia = ifatoia(ifa_ifwithbroadaddr(sintosa(dst)))) == NULL &&
  231                     (ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst)))) == NULL) {
  232                         IPSTAT_INC(ips_noroute);
  233                         error = ENETUNREACH;
  234                         goto bad;
  235                 }
  236                 ip->ip_dst.s_addr = INADDR_BROADCAST;
  237                 dst->sin_addr = ip->ip_dst;
  238                 ifp = ia->ia_ifp;
  239                 ip->ip_ttl = 1;
  240                 isbroadcast = 1;
  241         } else if (flags & IP_ROUTETOIF) {
  242                 if ((ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst)))) == NULL &&
  243                     (ia = ifatoia(ifa_ifwithnet(sintosa(dst), 0))) == NULL) {
  244                         IPSTAT_INC(ips_noroute);
  245                         error = ENETUNREACH;
  246                         goto bad;
  247                 }
  248                 ifp = ia->ia_ifp;
  249                 ip->ip_ttl = 1;
  250                 isbroadcast = in_broadcast(dst->sin_addr, ifp);
  251         } else if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) &&
  252             imo != NULL && imo->imo_multicast_ifp != NULL) {
  253                 /*
  254                  * Bypass the normal routing lookup for multicast
  255                  * packets if the interface is specified.
  256                  */
  257                 ifp = imo->imo_multicast_ifp;
  258                 IFP_TO_IA(ifp, ia);
  259                 isbroadcast = 0;        /* fool gcc */
  260         } else {
  261                 /*
  262                  * We want to do any cloning requested by the link layer,
  263                  * as this is probably required in all cases for correct
  264                  * operation (as it is for ARP).
  265                  */
  266                 if (rte == NULL) {
  267 #ifdef RADIX_MPATH
  268                         rtalloc_mpath_fib(ro,
  269                             ntohl(ip->ip_src.s_addr ^ ip->ip_dst.s_addr),
  270                             inp ? inp->inp_inc.inc_fibnum : M_GETFIB(m));
  271 #else
  272                         in_rtalloc_ign(ro, 0,
  273                             inp ? inp->inp_inc.inc_fibnum : M_GETFIB(m));
  274 #endif
  275                         rte = ro->ro_rt;
  276                 }
  277                 if (rte == NULL ||
  278                     rte->rt_ifp == NULL ||
  279                     !RT_LINK_IS_UP(rte->rt_ifp)) {
  280 #ifdef IPSEC
  281                         /*
  282                          * There is no route for this packet, but it is
  283                          * possible that a matching SPD entry exists.
  284                          */
  285                         no_route_but_check_spd = 1;
  286                         mtu = 0; /* Silence GCC warning. */
  287                         goto sendit;
  288 #endif
  289                         IPSTAT_INC(ips_noroute);
  290                         error = EHOSTUNREACH;
  291                         goto bad;
  292                 }
  293                 ia = ifatoia(rte->rt_ifa);
  294                 ifa_ref(&ia->ia_ifa);
  295                 ifp = rte->rt_ifp;
  296                 rte->rt_rmx.rmx_pksent++;
  297                 if (rte->rt_flags & RTF_GATEWAY)
  298                         dst = (struct sockaddr_in *)rte->rt_gateway;
  299                 if (rte->rt_flags & RTF_HOST)
  300                         isbroadcast = (rte->rt_flags & RTF_BROADCAST);
  301                 else
  302                         isbroadcast = in_broadcast(dst->sin_addr, ifp);
  303         }
  304         /*
  305          * Calculate MTU.  If we have a route that is up, use that,
  306          * otherwise use the interface's MTU.
  307          */
  308         if (rte != NULL && (rte->rt_flags & (RTF_UP|RTF_HOST))) {
  309                 /*
  310                  * This case can happen if the user changed the MTU
  311                  * of an interface after enabling IP on it.  Because
  312                  * most netifs don't keep track of routes pointing to
  313                  * them, there is no way for one to update all its
  314                  * routes when the MTU is changed.
  315                  */
  316                 if (rte->rt_rmx.rmx_mtu > ifp->if_mtu)
  317                         rte->rt_rmx.rmx_mtu = ifp->if_mtu;
  318                 mtu = rte->rt_rmx.rmx_mtu;
  319         } else {
  320                 mtu = ifp->if_mtu;
  321         }
  322         /* Catch a possible divide by zero later. */
  323         KASSERT(mtu > 0, ("%s: mtu %d <= 0, rte=%p (rt_flags=0x%08x) ifp=%p",
  324             __func__, mtu, rte, (rte != NULL) ? rte->rt_flags : 0, ifp));
  325         if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
  326                 m->m_flags |= M_MCAST;
  327                 /*
  328                  * IP destination address is multicast.  Make sure "dst"
  329                  * still points to the address in "ro".  (It may have been
  330                  * changed to point to a gateway address, above.)
  331                  */
  332                 dst = (struct sockaddr_in *)&ro->ro_dst;
  333                 /*
  334                  * See if the caller provided any multicast options
  335                  */
  336                 if (imo != NULL) {
  337                         ip->ip_ttl = imo->imo_multicast_ttl;
  338                         if (imo->imo_multicast_vif != -1)
  339                                 ip->ip_src.s_addr =
  340                                     ip_mcast_src ?
  341                                     ip_mcast_src(imo->imo_multicast_vif) :
  342                                     INADDR_ANY;
  343                 } else
  344                         ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL;
  345                 /*
  346                  * Confirm that the outgoing interface supports multicast.
  347                  */
  348                 if ((imo == NULL) || (imo->imo_multicast_vif == -1)) {
  349                         if ((ifp->if_flags & IFF_MULTICAST) == 0) {
  350                                 IPSTAT_INC(ips_noroute);
  351                                 error = ENETUNREACH;
  352                                 goto bad;
  353                         }
  354                 }
  355                 /*
  356                  * If source address not specified yet, use address
  357                  * of outgoing interface.
  358                  */
  359                 if (ip->ip_src.s_addr == INADDR_ANY) {
  360                         /* Interface may have no addresses. */
  361                         if (ia != NULL)
  362                                 ip->ip_src = IA_SIN(ia)->sin_addr;
  363                 }
  364 
  365                 if ((imo == NULL && in_mcast_loop) ||
  366                     (imo && imo->imo_multicast_loop)) {
  367                         /*
  368                          * Loop back multicast datagram if not expressly
  369                          * forbidden to do so, even if we are not a member
  370                          * of the group; ip_input() will filter it later,
  371                          * thus deferring a hash lookup and mutex acquisition
  372                          * at the expense of a cheap copy using m_copym().
  373                          */
  374                         ip_mloopback(ifp, m, dst, hlen);
  375                 } else {
  376                         /*
  377                          * If we are acting as a multicast router, perform
  378                          * multicast forwarding as if the packet had just
  379                          * arrived on the interface to which we are about
  380                          * to send.  The multicast forwarding function
  381                          * recursively calls this function, using the
  382                          * IP_FORWARDING flag to prevent infinite recursion.
  383                          *
  384                          * Multicasts that are looped back by ip_mloopback(),
  385                          * above, will be forwarded by the ip_input() routine,
  386                          * if necessary.
  387                          */
  388                         if (V_ip_mrouter && (flags & IP_FORWARDING) == 0) {
  389                                 /*
  390                                  * If rsvp daemon is not running, do not
  391                                  * set ip_moptions. This ensures that the packet
  392                                  * is multicast and not just sent down one link
  393                                  * as prescribed by rsvpd.
  394                                  */
  395                                 if (!V_rsvp_on)
  396                                         imo = NULL;
  397                                 if (ip_mforward &&
  398                                     ip_mforward(ip, ifp, m, imo) != 0) {
  399                                         m_freem(m);
  400                                         goto done;
  401                                 }
  402                         }
  403                 }
  404 
  405                 /*
  406                  * Multicasts with a time-to-live of zero may be looped-
  407                  * back, above, but must not be transmitted on a network.
  408                  * Also, multicasts addressed to the loopback interface
  409                  * are not sent -- the above call to ip_mloopback() will
  410                  * loop back a copy. ip_input() will drop the copy if
  411                  * this host does not belong to the destination group on
  412                  * the loopback interface.
  413                  */
  414                 if (ip->ip_ttl == 0 || ifp->if_flags & IFF_LOOPBACK) {
  415                         m_freem(m);
  416                         goto done;
  417                 }
  418 
  419                 goto sendit;
  420         }
  421 
  422         /*
  423          * If the source address is not specified yet, use the address
  424          * of the outoing interface.
  425          */
  426         if (ip->ip_src.s_addr == INADDR_ANY) {
  427                 /* Interface may have no addresses. */
  428                 if (ia != NULL) {
  429                         ip->ip_src = IA_SIN(ia)->sin_addr;
  430                 }
  431         }
  432 
  433         /*
  434          * Verify that we have any chance at all of being able to queue the
  435          * packet or packet fragments, unless ALTQ is enabled on the given
  436          * interface in which case packetdrop should be done by queueing.
  437          */
  438         n = ip->ip_len / mtu + 1; /* how many fragments ? */
  439         if (
  440 #ifdef ALTQ
  441             (!ALTQ_IS_ENABLED(&ifp->if_snd)) &&
  442 #endif /* ALTQ */
  443             (ifp->if_snd.ifq_len + n) >= ifp->if_snd.ifq_maxlen ) {
  444                 error = ENOBUFS;
  445                 IPSTAT_INC(ips_odropped);
  446                 ifp->if_snd.ifq_drops += n;
  447                 goto bad;
  448         }
  449 
  450         /*
  451          * Look for broadcast address and
  452          * verify user is allowed to send
  453          * such a packet.
  454          */
  455         if (isbroadcast) {
  456                 if ((ifp->if_flags & IFF_BROADCAST) == 0) {
  457                         error = EADDRNOTAVAIL;
  458                         goto bad;
  459                 }
  460                 if ((flags & IP_ALLOWBROADCAST) == 0) {
  461                         error = EACCES;
  462                         goto bad;
  463                 }
  464                 /* don't allow broadcast messages to be fragmented */
  465                 if (ip->ip_len > mtu) {
  466                         error = EMSGSIZE;
  467                         goto bad;
  468                 }
  469                 m->m_flags |= M_BCAST;
  470         } else {
  471                 m->m_flags &= ~M_BCAST;
  472         }
  473 
  474 sendit:
  475 #ifdef IPSEC
  476         switch(ip_ipsec_output(&m, inp, &flags, &error)) {
  477         case 1:
  478                 goto bad;
  479         case -1:
  480                 goto done;
  481         case 0:
  482         default:
  483                 break;  /* Continue with packet processing. */
  484         }
  485         /*
  486          * Check if there was a route for this packet; return error if not.
  487          */
  488         if (no_route_but_check_spd) {
  489                 IPSTAT_INC(ips_noroute);
  490                 error = EHOSTUNREACH;
  491                 goto bad;
  492         }
  493         /* Update variables that are affected by ipsec4_output(). */
  494         ip = mtod(m, struct ip *);
  495         hlen = ip->ip_hl << 2;
  496 #endif /* IPSEC */
  497 
  498         /* Jump over all PFIL processing if hooks are not active. */
  499         if (!PFIL_HOOKED(&V_inet_pfil_hook))
  500                 goto passout;
  501 
  502         /* Run through list of hooks for output packets. */
  503         odst.s_addr = ip->ip_dst.s_addr;
  504         error = pfil_run_hooks(&V_inet_pfil_hook, &m, ifp, PFIL_OUT, inp);
  505         if (error != 0 || m == NULL)
  506                 goto done;
  507 
  508         ip = mtod(m, struct ip *);
  509 
  510         /* See if destination IP address was changed by packet filter. */
  511         if (odst.s_addr != ip->ip_dst.s_addr) {
  512                 m->m_flags |= M_SKIP_FIREWALL;
  513                 /* If destination is now ourself drop to ip_input(). */
  514                 if (in_localip(ip->ip_dst)) {
  515                         m->m_flags |= M_FASTFWD_OURS;
  516                         if (m->m_pkthdr.rcvif == NULL)
  517                                 m->m_pkthdr.rcvif = V_loif;
  518                         if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
  519                                 m->m_pkthdr.csum_flags |=
  520                                     CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
  521                                 m->m_pkthdr.csum_data = 0xffff;
  522                         }
  523                         m->m_pkthdr.csum_flags |=
  524                             CSUM_IP_CHECKED | CSUM_IP_VALID;
  525 #ifdef SCTP
  526                         if (m->m_pkthdr.csum_flags & CSUM_SCTP)
  527                                 m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
  528 #endif
  529                         error = netisr_queue(NETISR_IP, m);
  530                         goto done;
  531                 } else {
  532                         if (ia != NULL)
  533                                 ifa_free(&ia->ia_ifa);
  534                         goto again;     /* Redo the routing table lookup. */
  535                 }
  536         }
  537 
  538         /* See if local, if yes, send it to netisr with IP_FASTFWD_OURS. */
  539         if (m->m_flags & M_FASTFWD_OURS) {
  540                 if (m->m_pkthdr.rcvif == NULL)
  541                         m->m_pkthdr.rcvif = V_loif;
  542                 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
  543                         m->m_pkthdr.csum_flags |=
  544                             CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
  545                         m->m_pkthdr.csum_data = 0xffff;
  546                 }
  547 #ifdef SCTP
  548                 if (m->m_pkthdr.csum_flags & CSUM_SCTP)
  549                         m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
  550 #endif
  551                 m->m_pkthdr.csum_flags |=
  552                             CSUM_IP_CHECKED | CSUM_IP_VALID;
  553 
  554                 error = netisr_queue(NETISR_IP, m);
  555                 goto done;
  556         }
  557         /* Or forward to some other address? */
  558         if ((m->m_flags & M_IP_NEXTHOP) &&
  559             (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) {
  560                 dst = (struct sockaddr_in *)&ro->ro_dst;
  561                 bcopy((fwd_tag+1), dst, sizeof(struct sockaddr_in));
  562                 m->m_flags |= M_SKIP_FIREWALL;
  563                 m->m_flags &= ~M_IP_NEXTHOP;
  564                 m_tag_delete(m, fwd_tag);
  565                 if (ia != NULL)
  566                         ifa_free(&ia->ia_ifa);
  567                 goto again;
  568         }
  569 
  570 passout:
  571         /* 127/8 must not appear on wire - RFC1122. */
  572         if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
  573             (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) {
  574                 if ((ifp->if_flags & IFF_LOOPBACK) == 0) {
  575                         IPSTAT_INC(ips_badaddr);
  576                         error = EADDRNOTAVAIL;
  577                         goto bad;
  578                 }
  579         }
  580 
  581         m->m_pkthdr.csum_flags |= CSUM_IP;
  582         sw_csum = m->m_pkthdr.csum_flags & ~ifp->if_hwassist;
  583         if (sw_csum & CSUM_DELAY_DATA) {
  584                 in_delayed_cksum(m);
  585                 sw_csum &= ~CSUM_DELAY_DATA;
  586         }
  587 #ifdef SCTP
  588         if (sw_csum & CSUM_SCTP) {
  589                 sctp_delayed_cksum(m, (uint32_t)(ip->ip_hl << 2));
  590                 sw_csum &= ~CSUM_SCTP;
  591         }
  592 #endif
  593         m->m_pkthdr.csum_flags &= ifp->if_hwassist;
  594 
  595         /*
  596          * If small enough for interface, or the interface will take
  597          * care of the fragmentation for us, we can just send directly.
  598          */
  599         if (ip->ip_len <= mtu ||
  600             (m->m_pkthdr.csum_flags & ifp->if_hwassist & CSUM_TSO) != 0 ||
  601             ((ip->ip_off & IP_DF) == 0 && (ifp->if_hwassist & CSUM_FRAGMENT))) {
  602                 ip->ip_len = htons(ip->ip_len);
  603                 ip->ip_off = htons(ip->ip_off);
  604                 ip->ip_sum = 0;
  605                 if (sw_csum & CSUM_DELAY_IP)
  606                         ip->ip_sum = in_cksum(m, hlen);
  607 
  608                 /*
  609                  * Record statistics for this interface address.
  610                  * With CSUM_TSO the byte/packet count will be slightly
  611                  * incorrect because we count the IP+TCP headers only
  612                  * once instead of for every generated packet.
  613                  */
  614                 if (!(flags & IP_FORWARDING) && ia) {
  615                         if (m->m_pkthdr.csum_flags & CSUM_TSO)
  616                                 ia->ia_ifa.if_opackets +=
  617                                     m->m_pkthdr.len / m->m_pkthdr.tso_segsz;
  618                         else
  619                                 ia->ia_ifa.if_opackets++;
  620                         ia->ia_ifa.if_obytes += m->m_pkthdr.len;
  621                 }
  622 #ifdef MBUF_STRESS_TEST
  623                 if (mbuf_frag_size && m->m_pkthdr.len > mbuf_frag_size)
  624                         m = m_fragment(m, M_DONTWAIT, mbuf_frag_size);
  625 #endif
  626                 /*
  627                  * Reset layer specific mbuf flags
  628                  * to avoid confusing lower layers.
  629                  */
  630                 m->m_flags &= ~(M_PROTOFLAGS);
  631                 error = (*ifp->if_output)(ifp, m,
  632                                 (struct sockaddr *)dst, ro);
  633                 goto done;
  634         }
  635 
  636         /* Balk when DF bit is set or the interface didn't support TSO. */
  637         if ((ip->ip_off & IP_DF) || (m->m_pkthdr.csum_flags & CSUM_TSO)) {
  638                 error = EMSGSIZE;
  639                 IPSTAT_INC(ips_cantfrag);
  640                 goto bad;
  641         }
  642 
  643         /*
  644          * Too large for interface; fragment if possible. If successful,
  645          * on return, m will point to a list of packets to be sent.
  646          */
  647         error = ip_fragment(ip, &m, mtu, ifp->if_hwassist, sw_csum);
  648         if (error)
  649                 goto bad;
  650         for (; m; m = m0) {
  651                 m0 = m->m_nextpkt;
  652                 m->m_nextpkt = 0;
  653                 if (error == 0) {
  654                         /* Record statistics for this interface address. */
  655                         if (ia != NULL) {
  656                                 ia->ia_ifa.if_opackets++;
  657                                 ia->ia_ifa.if_obytes += m->m_pkthdr.len;
  658                         }
  659                         /*
  660                          * Reset layer specific mbuf flags
  661                          * to avoid confusing upper layers.
  662                          */
  663                         m->m_flags &= ~(M_PROTOFLAGS);
  664 
  665                         error = (*ifp->if_output)(ifp, m,
  666                             (struct sockaddr *)dst, ro);
  667                 } else
  668                         m_freem(m);
  669         }
  670 
  671         if (error == 0)
  672                 IPSTAT_INC(ips_fragmented);
  673 
  674 done:
  675         if (ro == &iproute)
  676                 RO_RTFREE(ro);
  677         if (ia != NULL)
  678                 ifa_free(&ia->ia_ifa);
  679         return (error);
  680 bad:
  681         m_freem(m);
  682         goto done;
  683 }
  684 
  685 /*
  686  * Create a chain of fragments which fit the given mtu. m_frag points to the
  687  * mbuf to be fragmented; on return it points to the chain with the fragments.
  688  * Return 0 if no error. If error, m_frag may contain a partially built
  689  * chain of fragments that should be freed by the caller.
  690  *
  691  * if_hwassist_flags is the hw offload capabilities (see if_data.ifi_hwassist)
  692  * sw_csum contains the delayed checksums flags (e.g., CSUM_DELAY_IP).
  693  */
  694 int
  695 ip_fragment(struct ip *ip, struct mbuf **m_frag, int mtu,
  696     u_long if_hwassist_flags, int sw_csum)
  697 {
  698         int error = 0;
  699         int hlen = ip->ip_hl << 2;
  700         int len = (mtu - hlen) & ~7;    /* size of payload in each fragment */
  701         int off;
  702         struct mbuf *m0 = *m_frag;      /* the original packet          */
  703         int firstlen;
  704         struct mbuf **mnext;
  705         int nfrags;
  706 
  707         if (ip->ip_off & IP_DF) {       /* Fragmentation not allowed */
  708                 IPSTAT_INC(ips_cantfrag);
  709                 return EMSGSIZE;
  710         }
  711 
  712         /*
  713          * Must be able to put at least 8 bytes per fragment.
  714          */
  715         if (len < 8)
  716                 return EMSGSIZE;
  717 
  718         /*
  719          * If the interface will not calculate checksums on
  720          * fragmented packets, then do it here.
  721          */
  722         if (m0->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
  723                 in_delayed_cksum(m0);
  724                 m0->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
  725         }
  726 #ifdef SCTP
  727         if (m0->m_pkthdr.csum_flags & CSUM_SCTP) {
  728                 sctp_delayed_cksum(m0, hlen);
  729                 m0->m_pkthdr.csum_flags &= ~CSUM_SCTP;
  730         }
  731 #endif
  732         if (len > PAGE_SIZE) {
  733                 /* 
  734                  * Fragment large datagrams such that each segment 
  735                  * contains a multiple of PAGE_SIZE amount of data, 
  736                  * plus headers. This enables a receiver to perform 
  737                  * page-flipping zero-copy optimizations.
  738                  *
  739                  * XXX When does this help given that sender and receiver
  740                  * could have different page sizes, and also mtu could
  741                  * be less than the receiver's page size ?
  742                  */
  743                 int newlen;
  744                 struct mbuf *m;
  745 
  746                 for (m = m0, off = 0; m && (off+m->m_len) <= mtu; m = m->m_next)
  747                         off += m->m_len;
  748 
  749                 /*
  750                  * firstlen (off - hlen) must be aligned on an 
  751                  * 8-byte boundary
  752                  */
  753                 if (off < hlen)
  754                         goto smart_frag_failure;
  755                 off = ((off - hlen) & ~7) + hlen;
  756                 newlen = (~PAGE_MASK) & mtu;
  757                 if ((newlen + sizeof (struct ip)) > mtu) {
  758                         /* we failed, go back the default */
  759 smart_frag_failure:
  760                         newlen = len;
  761                         off = hlen + len;
  762                 }
  763                 len = newlen;
  764 
  765         } else {
  766                 off = hlen + len;
  767         }
  768 
  769         firstlen = off - hlen;
  770         mnext = &m0->m_nextpkt;         /* pointer to next packet */
  771 
  772         /*
  773          * Loop through length of segment after first fragment,
  774          * make new header and copy data of each part and link onto chain.
  775          * Here, m0 is the original packet, m is the fragment being created.
  776          * The fragments are linked off the m_nextpkt of the original
  777          * packet, which after processing serves as the first fragment.
  778          */
  779         for (nfrags = 1; off < ip->ip_len; off += len, nfrags++) {
  780                 struct ip *mhip;        /* ip header on the fragment */
  781                 struct mbuf *m;
  782                 int mhlen = sizeof (struct ip);
  783 
  784                 MGETHDR(m, M_DONTWAIT, MT_DATA);
  785                 if (m == NULL) {
  786                         error = ENOBUFS;
  787                         IPSTAT_INC(ips_odropped);
  788                         goto done;
  789                 }
  790                 m->m_flags |= (m0->m_flags & M_MCAST) | M_FRAG;
  791                 /*
  792                  * In the first mbuf, leave room for the link header, then
  793                  * copy the original IP header including options. The payload
  794                  * goes into an additional mbuf chain returned by m_copym().
  795                  */
  796                 m->m_data += max_linkhdr;
  797                 mhip = mtod(m, struct ip *);
  798                 *mhip = *ip;
  799                 if (hlen > sizeof (struct ip)) {
  800                         mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip);
  801                         mhip->ip_v = IPVERSION;
  802                         mhip->ip_hl = mhlen >> 2;
  803                 }
  804                 m->m_len = mhlen;
  805                 /* XXX do we need to add ip->ip_off below ? */
  806                 mhip->ip_off = ((off - hlen) >> 3) + ip->ip_off;
  807                 if (off + len >= ip->ip_len) {  /* last fragment */
  808                         len = ip->ip_len - off;
  809                         m->m_flags |= M_LASTFRAG;
  810                 } else
  811                         mhip->ip_off |= IP_MF;
  812                 mhip->ip_len = htons((u_short)(len + mhlen));
  813                 m->m_next = m_copym(m0, off, len, M_DONTWAIT);
  814                 if (m->m_next == NULL) {        /* copy failed */
  815                         m_free(m);
  816                         error = ENOBUFS;        /* ??? */
  817                         IPSTAT_INC(ips_odropped);
  818                         goto done;
  819                 }
  820                 m->m_pkthdr.len = mhlen + len;
  821                 m->m_pkthdr.rcvif = NULL;
  822 #ifdef MAC
  823                 mac_netinet_fragment(m0, m);
  824 #endif
  825                 m->m_pkthdr.csum_flags = m0->m_pkthdr.csum_flags;
  826                 mhip->ip_off = htons(mhip->ip_off);
  827                 mhip->ip_sum = 0;
  828                 if (sw_csum & CSUM_DELAY_IP)
  829                         mhip->ip_sum = in_cksum(m, mhlen);
  830                 *mnext = m;
  831                 mnext = &m->m_nextpkt;
  832         }
  833         IPSTAT_ADD(ips_ofragments, nfrags);
  834 
  835         /* set first marker for fragment chain */
  836         m0->m_flags |= M_FIRSTFRAG | M_FRAG;
  837         m0->m_pkthdr.csum_data = nfrags;
  838 
  839         /*
  840          * Update first fragment by trimming what's been copied out
  841          * and updating header.
  842          */
  843         m_adj(m0, hlen + firstlen - ip->ip_len);
  844         m0->m_pkthdr.len = hlen + firstlen;
  845         ip->ip_len = htons((u_short)m0->m_pkthdr.len);
  846         ip->ip_off |= IP_MF;
  847         ip->ip_off = htons(ip->ip_off);
  848         ip->ip_sum = 0;
  849         if (sw_csum & CSUM_DELAY_IP)
  850                 ip->ip_sum = in_cksum(m0, hlen);
  851 
  852 done:
  853         *m_frag = m0;
  854         return error;
  855 }
  856 
  857 void
  858 in_delayed_cksum(struct mbuf *m)
  859 {
  860         struct ip *ip;
  861         u_short csum, offset;
  862 
  863         ip = mtod(m, struct ip *);
  864         offset = ip->ip_hl << 2 ;
  865         csum = in_cksum_skip(m, ip->ip_len, offset);
  866         if (m->m_pkthdr.csum_flags & CSUM_UDP && csum == 0)
  867                 csum = 0xffff;
  868         offset += m->m_pkthdr.csum_data;        /* checksum offset */
  869 
  870         if (offset + sizeof(u_short) > m->m_len) {
  871                 printf("delayed m_pullup, m->len: %d  off: %d  p: %d\n",
  872                     m->m_len, offset, ip->ip_p);
  873                 /*
  874                  * XXX
  875                  * this shouldn't happen, but if it does, the
  876                  * correct behavior may be to insert the checksum
  877                  * in the appropriate next mbuf in the chain.
  878                  */
  879                 return;
  880         }
  881         *(u_short *)(m->m_data + offset) = csum;
  882 }
  883 
  884 /*
  885  * IP socket option processing.
  886  */
  887 int
  888 ip_ctloutput(struct socket *so, struct sockopt *sopt)
  889 {
  890         struct  inpcb *inp = sotoinpcb(so);
  891         int     error, optval;
  892 
  893         error = optval = 0;
  894         if (sopt->sopt_level != IPPROTO_IP) {
  895                 error = EINVAL;
  896 
  897                 if (sopt->sopt_level == SOL_SOCKET &&
  898                     sopt->sopt_dir == SOPT_SET) {
  899                         switch (sopt->sopt_name) {
  900                         case SO_REUSEADDR:
  901                                 INP_WLOCK(inp);
  902                                 if ((so->so_options & SO_REUSEADDR) != 0)
  903                                         inp->inp_flags2 |= INP_REUSEADDR;
  904                                 else
  905                                         inp->inp_flags2 &= ~INP_REUSEADDR;
  906                                 INP_WUNLOCK(inp);
  907                                 error = 0;
  908                                 break;
  909                         case SO_REUSEPORT:
  910                                 INP_WLOCK(inp);
  911                                 if ((so->so_options & SO_REUSEPORT) != 0)
  912                                         inp->inp_flags2 |= INP_REUSEPORT;
  913                                 else
  914                                         inp->inp_flags2 &= ~INP_REUSEPORT;
  915                                 INP_WUNLOCK(inp);
  916                                 error = 0;
  917                                 break;
  918                         case SO_SETFIB:
  919                                 INP_WLOCK(inp);
  920                                 inp->inp_inc.inc_fibnum = so->so_fibnum;
  921                                 INP_WUNLOCK(inp);
  922                                 error = 0;
  923                                 break;
  924                         default:
  925                                 break;
  926                         }
  927                 }
  928                 return (error);
  929         }
  930 
  931         switch (sopt->sopt_dir) {
  932         case SOPT_SET:
  933                 switch (sopt->sopt_name) {
  934                 case IP_OPTIONS:
  935 #ifdef notyet
  936                 case IP_RETOPTS:
  937 #endif
  938                 {
  939                         struct mbuf *m;
  940                         if (sopt->sopt_valsize > MLEN) {
  941                                 error = EMSGSIZE;
  942                                 break;
  943                         }
  944                         MGET(m, sopt->sopt_td ? M_WAIT : M_DONTWAIT, MT_DATA);
  945                         if (m == NULL) {
  946                                 error = ENOBUFS;
  947                                 break;
  948                         }
  949                         m->m_len = sopt->sopt_valsize;
  950                         error = sooptcopyin(sopt, mtod(m, char *), m->m_len,
  951                                             m->m_len);
  952                         if (error) {
  953                                 m_free(m);
  954                                 break;
  955                         }
  956                         INP_WLOCK(inp);
  957                         error = ip_pcbopts(inp, sopt->sopt_name, m);
  958                         INP_WUNLOCK(inp);
  959                         return (error);
  960                 }
  961 
  962                 case IP_BINDANY:
  963                         if (sopt->sopt_td != NULL) {
  964                                 error = priv_check(sopt->sopt_td,
  965                                     PRIV_NETINET_BINDANY);
  966                                 if (error)
  967                                         break;
  968                         }
  969                         /* FALLTHROUGH */
  970                 case IP_TOS:
  971                 case IP_TTL:
  972                 case IP_MINTTL:
  973                 case IP_RECVOPTS:
  974                 case IP_RECVRETOPTS:
  975                 case IP_RECVDSTADDR:
  976                 case IP_RECVTTL:
  977                 case IP_RECVIF:
  978                 case IP_FAITH:
  979                 case IP_ONESBCAST:
  980                 case IP_DONTFRAG:
  981                 case IP_RECVTOS:
  982                         error = sooptcopyin(sopt, &optval, sizeof optval,
  983                                             sizeof optval);
  984                         if (error)
  985                                 break;
  986 
  987                         switch (sopt->sopt_name) {
  988                         case IP_TOS:
  989                                 inp->inp_ip_tos = optval;
  990                                 break;
  991 
  992                         case IP_TTL:
  993                                 inp->inp_ip_ttl = optval;
  994                                 break;
  995 
  996                         case IP_MINTTL:
  997                                 if (optval >= 0 && optval <= MAXTTL)
  998                                         inp->inp_ip_minttl = optval;
  999                                 else
 1000                                         error = EINVAL;
 1001                                 break;
 1002 
 1003 #define OPTSET(bit) do {                                                \
 1004         INP_WLOCK(inp);                                                 \
 1005         if (optval)                                                     \
 1006                 inp->inp_flags |= bit;                                  \
 1007         else                                                            \
 1008                 inp->inp_flags &= ~bit;                                 \
 1009         INP_WUNLOCK(inp);                                               \
 1010 } while (0)
 1011 
 1012                         case IP_RECVOPTS:
 1013                                 OPTSET(INP_RECVOPTS);
 1014                                 break;
 1015 
 1016                         case IP_RECVRETOPTS:
 1017                                 OPTSET(INP_RECVRETOPTS);
 1018                                 break;
 1019 
 1020                         case IP_RECVDSTADDR:
 1021                                 OPTSET(INP_RECVDSTADDR);
 1022                                 break;
 1023 
 1024                         case IP_RECVTTL:
 1025                                 OPTSET(INP_RECVTTL);
 1026                                 break;
 1027 
 1028                         case IP_RECVIF:
 1029                                 OPTSET(INP_RECVIF);
 1030                                 break;
 1031 
 1032                         case IP_FAITH:
 1033                                 OPTSET(INP_FAITH);
 1034                                 break;
 1035 
 1036                         case IP_ONESBCAST:
 1037                                 OPTSET(INP_ONESBCAST);
 1038                                 break;
 1039                         case IP_DONTFRAG:
 1040                                 OPTSET(INP_DONTFRAG);
 1041                                 break;
 1042                         case IP_BINDANY:
 1043                                 OPTSET(INP_BINDANY);
 1044                                 break;
 1045                         case IP_RECVTOS:
 1046                                 OPTSET(INP_RECVTOS);
 1047                                 break;
 1048                         }
 1049                         break;
 1050 #undef OPTSET
 1051 
 1052                 /*
 1053                  * Multicast socket options are processed by the in_mcast
 1054                  * module.
 1055                  */
 1056                 case IP_MULTICAST_IF:
 1057                 case IP_MULTICAST_VIF:
 1058                 case IP_MULTICAST_TTL:
 1059                 case IP_MULTICAST_LOOP:
 1060                 case IP_ADD_MEMBERSHIP:
 1061                 case IP_DROP_MEMBERSHIP:
 1062                 case IP_ADD_SOURCE_MEMBERSHIP:
 1063                 case IP_DROP_SOURCE_MEMBERSHIP:
 1064                 case IP_BLOCK_SOURCE:
 1065                 case IP_UNBLOCK_SOURCE:
 1066                 case IP_MSFILTER:
 1067                 case MCAST_JOIN_GROUP:
 1068                 case MCAST_LEAVE_GROUP:
 1069                 case MCAST_JOIN_SOURCE_GROUP:
 1070                 case MCAST_LEAVE_SOURCE_GROUP:
 1071                 case MCAST_BLOCK_SOURCE:
 1072                 case MCAST_UNBLOCK_SOURCE:
 1073                         error = inp_setmoptions(inp, sopt);
 1074                         break;
 1075 
 1076                 case IP_PORTRANGE:
 1077                         error = sooptcopyin(sopt, &optval, sizeof optval,
 1078                                             sizeof optval);
 1079                         if (error)
 1080                                 break;
 1081 
 1082                         INP_WLOCK(inp);
 1083                         switch (optval) {
 1084                         case IP_PORTRANGE_DEFAULT:
 1085                                 inp->inp_flags &= ~(INP_LOWPORT);
 1086                                 inp->inp_flags &= ~(INP_HIGHPORT);
 1087                                 break;
 1088 
 1089                         case IP_PORTRANGE_HIGH:
 1090                                 inp->inp_flags &= ~(INP_LOWPORT);
 1091                                 inp->inp_flags |= INP_HIGHPORT;
 1092                                 break;
 1093 
 1094                         case IP_PORTRANGE_LOW:
 1095                                 inp->inp_flags &= ~(INP_HIGHPORT);
 1096                                 inp->inp_flags |= INP_LOWPORT;
 1097                                 break;
 1098 
 1099                         default:
 1100                                 error = EINVAL;
 1101                                 break;
 1102                         }
 1103                         INP_WUNLOCK(inp);
 1104                         break;
 1105 
 1106 #ifdef IPSEC
 1107                 case IP_IPSEC_POLICY:
 1108                 {
 1109                         caddr_t req;
 1110                         struct mbuf *m;
 1111 
 1112                         if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */
 1113                                 break;
 1114                         if ((error = soopt_mcopyin(sopt, m)) != 0) /* XXX */
 1115                                 break;
 1116                         req = mtod(m, caddr_t);
 1117                         error = ipsec_set_policy(inp, sopt->sopt_name, req,
 1118                             m->m_len, (sopt->sopt_td != NULL) ?
 1119                             sopt->sopt_td->td_ucred : NULL);
 1120                         m_freem(m);
 1121                         break;
 1122                 }
 1123 #endif /* IPSEC */
 1124 
 1125                 default:
 1126                         error = ENOPROTOOPT;
 1127                         break;
 1128                 }
 1129                 break;
 1130 
 1131         case SOPT_GET:
 1132                 switch (sopt->sopt_name) {
 1133                 case IP_OPTIONS:
 1134                 case IP_RETOPTS:
 1135                         if (inp->inp_options)
 1136                                 error = sooptcopyout(sopt, 
 1137                                                      mtod(inp->inp_options,
 1138                                                           char *),
 1139                                                      inp->inp_options->m_len);
 1140                         else
 1141                                 sopt->sopt_valsize = 0;
 1142                         break;
 1143 
 1144                 case IP_TOS:
 1145                 case IP_TTL:
 1146                 case IP_MINTTL:
 1147                 case IP_RECVOPTS:
 1148                 case IP_RECVRETOPTS:
 1149                 case IP_RECVDSTADDR:
 1150                 case IP_RECVTTL:
 1151                 case IP_RECVIF:
 1152                 case IP_PORTRANGE:
 1153                 case IP_FAITH:
 1154                 case IP_ONESBCAST:
 1155                 case IP_DONTFRAG:
 1156                 case IP_BINDANY:
 1157                 case IP_RECVTOS:
 1158                         switch (sopt->sopt_name) {
 1159 
 1160                         case IP_TOS:
 1161                                 optval = inp->inp_ip_tos;
 1162                                 break;
 1163 
 1164                         case IP_TTL:
 1165                                 optval = inp->inp_ip_ttl;
 1166                                 break;
 1167 
 1168                         case IP_MINTTL:
 1169                                 optval = inp->inp_ip_minttl;
 1170                                 break;
 1171 
 1172 #define OPTBIT(bit)     (inp->inp_flags & bit ? 1 : 0)
 1173 
 1174                         case IP_RECVOPTS:
 1175                                 optval = OPTBIT(INP_RECVOPTS);
 1176                                 break;
 1177 
 1178                         case IP_RECVRETOPTS:
 1179                                 optval = OPTBIT(INP_RECVRETOPTS);
 1180                                 break;
 1181 
 1182                         case IP_RECVDSTADDR:
 1183                                 optval = OPTBIT(INP_RECVDSTADDR);
 1184                                 break;
 1185 
 1186                         case IP_RECVTTL:
 1187                                 optval = OPTBIT(INP_RECVTTL);
 1188                                 break;
 1189 
 1190                         case IP_RECVIF:
 1191                                 optval = OPTBIT(INP_RECVIF);
 1192                                 break;
 1193 
 1194                         case IP_PORTRANGE:
 1195                                 if (inp->inp_flags & INP_HIGHPORT)
 1196                                         optval = IP_PORTRANGE_HIGH;
 1197                                 else if (inp->inp_flags & INP_LOWPORT)
 1198                                         optval = IP_PORTRANGE_LOW;
 1199                                 else
 1200                                         optval = 0;
 1201                                 break;
 1202 
 1203                         case IP_FAITH:
 1204                                 optval = OPTBIT(INP_FAITH);
 1205                                 break;
 1206 
 1207                         case IP_ONESBCAST:
 1208                                 optval = OPTBIT(INP_ONESBCAST);
 1209                                 break;
 1210                         case IP_DONTFRAG:
 1211                                 optval = OPTBIT(INP_DONTFRAG);
 1212                                 break;
 1213                         case IP_BINDANY:
 1214                                 optval = OPTBIT(INP_BINDANY);
 1215                                 break;
 1216                         case IP_RECVTOS:
 1217                                 optval = OPTBIT(INP_RECVTOS);
 1218                                 break;
 1219                         }
 1220                         error = sooptcopyout(sopt, &optval, sizeof optval);
 1221                         break;
 1222 
 1223                 /*
 1224                  * Multicast socket options are processed by the in_mcast
 1225                  * module.
 1226                  */
 1227                 case IP_MULTICAST_IF:
 1228                 case IP_MULTICAST_VIF:
 1229                 case IP_MULTICAST_TTL:
 1230                 case IP_MULTICAST_LOOP:
 1231                 case IP_MSFILTER:
 1232                         error = inp_getmoptions(inp, sopt);
 1233                         break;
 1234 
 1235 #ifdef IPSEC
 1236                 case IP_IPSEC_POLICY:
 1237                 {
 1238                         struct mbuf *m = NULL;
 1239                         caddr_t req = NULL;
 1240                         size_t len = 0;
 1241 
 1242                         if (m != 0) {
 1243                                 req = mtod(m, caddr_t);
 1244                                 len = m->m_len;
 1245                         }
 1246                         error = ipsec_get_policy(sotoinpcb(so), req, len, &m);
 1247                         if (error == 0)
 1248                                 error = soopt_mcopyout(sopt, m); /* XXX */
 1249                         if (error == 0)
 1250                                 m_freem(m);
 1251                         break;
 1252                 }
 1253 #endif /* IPSEC */
 1254 
 1255                 default:
 1256                         error = ENOPROTOOPT;
 1257                         break;
 1258                 }
 1259                 break;
 1260         }
 1261         return (error);
 1262 }
 1263 
 1264 /*
 1265  * Routine called from ip_output() to loop back a copy of an IP multicast
 1266  * packet to the input queue of a specified interface.  Note that this
 1267  * calls the output routine of the loopback "driver", but with an interface
 1268  * pointer that might NOT be a loopback interface -- evil, but easier than
 1269  * replicating that code here.
 1270  */
 1271 static void
 1272 ip_mloopback(struct ifnet *ifp, struct mbuf *m, struct sockaddr_in *dst,
 1273     int hlen)
 1274 {
 1275         register struct ip *ip;
 1276         struct mbuf *copym;
 1277 
 1278         /*
 1279          * Make a deep copy of the packet because we're going to
 1280          * modify the pack in order to generate checksums.
 1281          */
 1282         copym = m_dup(m, M_DONTWAIT);
 1283         if (copym != NULL && (copym->m_flags & M_EXT || copym->m_len < hlen))
 1284                 copym = m_pullup(copym, hlen);
 1285         if (copym != NULL) {
 1286                 /* If needed, compute the checksum and mark it as valid. */
 1287                 if (copym->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
 1288                         in_delayed_cksum(copym);
 1289                         copym->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
 1290                         copym->m_pkthdr.csum_flags |=
 1291                             CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
 1292                         copym->m_pkthdr.csum_data = 0xffff;
 1293                 }
 1294                 /*
 1295                  * We don't bother to fragment if the IP length is greater
 1296                  * than the interface's MTU.  Can this possibly matter?
 1297                  */
 1298                 ip = mtod(copym, struct ip *);
 1299                 ip->ip_len = htons(ip->ip_len);
 1300                 ip->ip_off = htons(ip->ip_off);
 1301                 ip->ip_sum = 0;
 1302                 ip->ip_sum = in_cksum(copym, hlen);
 1303 #if 1 /* XXX */
 1304                 if (dst->sin_family != AF_INET) {
 1305                         printf("ip_mloopback: bad address family %d\n",
 1306                                                 dst->sin_family);
 1307                         dst->sin_family = AF_INET;
 1308                 }
 1309 #endif
 1310                 if_simloop(ifp, copym, dst->sin_family, 0);
 1311         }
 1312 }

Cache object: 1cc24b7733ba0012a53c20d4f60cae2e


[ 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.