diff options
Diffstat (limited to 'freebsd/sys/netinet/ip_output.c')
| -rw-r--r-- | freebsd/sys/netinet/ip_output.c | 1284 |
1 files changed, 1284 insertions, 0 deletions
diff --git a/freebsd/sys/netinet/ip_output.c b/freebsd/sys/netinet/ip_output.c new file mode 100644 index 00000000..51132333 --- /dev/null +++ b/freebsd/sys/netinet/ip_output.c @@ -0,0 +1,1284 @@ +#include <freebsd/machine/rtems-bsd-config.h> + +/*- + * Copyright (c) 1982, 1986, 1988, 1990, 1993 + * The Regents of the University of California. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 4. Neither the name of the University nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + * @(#)ip_output.c 8.3 (Berkeley) 1/21/94 + */ + +#include <freebsd/sys/cdefs.h> +__FBSDID("$FreeBSD$"); + +#include <freebsd/local/opt_ipfw.h> +#include <freebsd/local/opt_ipsec.h> +#include <freebsd/local/opt_route.h> +#include <freebsd/local/opt_mbuf_stress_test.h> +#include <freebsd/local/opt_mpath.h> +#include <freebsd/local/opt_sctp.h> + +#include <freebsd/sys/param.h> +#include <freebsd/sys/systm.h> +#include <freebsd/sys/kernel.h> +#include <freebsd/sys/malloc.h> +#include <freebsd/sys/mbuf.h> +#include <freebsd/sys/priv.h> +#include <freebsd/sys/proc.h> +#include <freebsd/sys/protosw.h> +#include <freebsd/sys/socket.h> +#include <freebsd/sys/socketvar.h> +#include <freebsd/sys/sysctl.h> +#include <freebsd/sys/ucred.h> + +#include <freebsd/net/if.h> +#include <freebsd/net/if_llatbl.h> +#include <freebsd/net/netisr.h> +#include <freebsd/net/pfil.h> +#include <freebsd/net/route.h> +#include <freebsd/net/flowtable.h> +#ifdef RADIX_MPATH +#include <freebsd/net/radix_mpath.h> +#endif +#include <freebsd/net/vnet.h> + +#include <freebsd/netinet/in.h> +#include <freebsd/netinet/in_systm.h> +#include <freebsd/netinet/ip.h> +#include <freebsd/netinet/in_pcb.h> +#include <freebsd/netinet/in_var.h> +#include <freebsd/netinet/ip_var.h> +#include <freebsd/netinet/ip_options.h> +#ifdef SCTP +#include <freebsd/netinet/sctp.h> +#include <freebsd/netinet/sctp_crc32.h> +#endif + +#ifdef IPSEC +#include <freebsd/netinet/ip_ipsec.h> +#include <freebsd/netipsec/ipsec.h> +#endif /* IPSEC*/ + +#include <freebsd/machine/in_cksum.h> + +#include <freebsd/security/mac/mac_framework.h> + +#define print_ip(x, a, y) printf("%s %d.%d.%d.%d%s",\ + x, (ntohl(a.s_addr)>>24)&0xFF,\ + (ntohl(a.s_addr)>>16)&0xFF,\ + (ntohl(a.s_addr)>>8)&0xFF,\ + (ntohl(a.s_addr))&0xFF, y); + +VNET_DEFINE(u_short, ip_id); + +#ifdef MBUF_STRESS_TEST +int mbuf_frag_size = 0; +SYSCTL_INT(_net_inet_ip, OID_AUTO, mbuf_frag_size, CTLFLAG_RW, + &mbuf_frag_size, 0, "Fragment outgoing mbufs to this size"); +#endif + +static void ip_mloopback + (struct ifnet *, struct mbuf *, struct sockaddr_in *, int); + + +extern int in_mcast_loop; +extern struct protosw inetsw[]; + +/* + * IP output. The packet in mbuf chain m contains a skeletal IP + * header (with len, off, ttl, proto, tos, src, dst). + * The mbuf chain containing the packet will be freed. + * The mbuf opt, if present, will not be freed. + * In the IP forwarding case, the packet will arrive with options already + * inserted, so must have a NULL opt pointer. + */ +int +ip_output(struct mbuf *m, struct mbuf *opt, struct route *ro, int flags, + struct ip_moptions *imo, struct inpcb *inp) +{ + struct ip *ip; + struct ifnet *ifp = NULL; /* keep compiler happy */ + struct mbuf *m0; + int hlen = sizeof (struct ip); + int mtu; + int len, error = 0; + int nortfree = 0; + struct sockaddr_in *dst = NULL; /* keep compiler happy */ + struct in_ifaddr *ia = NULL; + int isbroadcast, sw_csum; + struct route iproute; + struct rtentry *rte; /* cache for ro->ro_rt */ + struct in_addr odst; +#ifdef IPFIREWALL_FORWARD + struct m_tag *fwd_tag = NULL; +#endif +#ifdef IPSEC + int no_route_but_check_spd = 0; +#endif + M_ASSERTPKTHDR(m); + + if (inp != NULL) { + INP_LOCK_ASSERT(inp); + M_SETFIB(m, inp->inp_inc.inc_fibnum); + if (inp->inp_flags & (INP_HW_FLOWID|INP_SW_FLOWID)) { + m->m_pkthdr.flowid = inp->inp_flowid; + m->m_flags |= M_FLOWID; + } + } + + if (ro == NULL) { + ro = &iproute; + bzero(ro, sizeof (*ro)); + +#ifdef FLOWTABLE + { + struct flentry *fle; + + /* + * The flow table returns route entries valid for up to 30 + * seconds; we rely on the remainder of ip_output() taking no + * longer than that long for the stability of ro_rt. The + * flow ID assignment must have happened before this point. + */ + if ((fle = flowtable_lookup_mbuf(V_ip_ft, m, AF_INET)) != NULL) { + flow_to_route(fle, ro); + nortfree = 1; + } + } +#endif + } + + if (opt) { + len = 0; + m = ip_insertoptions(m, opt, &len); + if (len != 0) + hlen = len; + } + ip = mtod(m, struct ip *); + + /* + * Fill in IP header. If we are not allowing fragmentation, + * then the ip_id field is meaningless, but we don't set it + * to zero. Doing so causes various problems when devices along + * the path (routers, load balancers, firewalls, etc.) illegally + * disable DF on our packet. Note that a 16-bit counter + * will wrap around in less than 10 seconds at 100 Mbit/s on a + * medium with MTU 1500. See Steven M. Bellovin, "A Technique + * for Counting NATted Hosts", Proc. IMW'02, available at + * <http://www.cs.columbia.edu/~smb/papers/fnat.pdf>. + */ + if ((flags & (IP_FORWARDING|IP_RAWOUTPUT)) == 0) { + ip->ip_v = IPVERSION; + ip->ip_hl = hlen >> 2; + ip->ip_id = ip_newid(); + IPSTAT_INC(ips_localout); + } else { + hlen = ip->ip_hl << 2; + } + + dst = (struct sockaddr_in *)&ro->ro_dst; +again: + /* + * If there is a cached route, + * check that it is to the same destination + * and is still up. If not, free it and try again. + * The address family should also be checked in case of sharing the + * cache with IPv6. + */ + rte = ro->ro_rt; + if (rte && ((rte->rt_flags & RTF_UP) == 0 || + rte->rt_ifp == NULL || + !RT_LINK_IS_UP(rte->rt_ifp) || + dst->sin_family != AF_INET || + dst->sin_addr.s_addr != ip->ip_dst.s_addr)) { + if (!nortfree) + RTFREE(rte); + rte = ro->ro_rt = (struct rtentry *)NULL; + ro->ro_lle = (struct llentry *)NULL; + } +#ifdef IPFIREWALL_FORWARD + if (rte == NULL && fwd_tag == NULL) { +#else + if (rte == NULL) { +#endif + bzero(dst, sizeof(*dst)); + dst->sin_family = AF_INET; + dst->sin_len = sizeof(*dst); + dst->sin_addr = ip->ip_dst; + } + /* + * If routing to interface only, short circuit routing lookup. + * The use of an all-ones broadcast address implies this; an + * interface is specified by the broadcast address of an interface, + * or the destination address of a ptp interface. + */ + if (flags & IP_SENDONES) { + if ((ia = ifatoia(ifa_ifwithbroadaddr(sintosa(dst)))) == NULL && + (ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst)))) == NULL) { + IPSTAT_INC(ips_noroute); + error = ENETUNREACH; + goto bad; + } + ip->ip_dst.s_addr = INADDR_BROADCAST; + dst->sin_addr = ip->ip_dst; + ifp = ia->ia_ifp; + ip->ip_ttl = 1; + isbroadcast = 1; + } else if (flags & IP_ROUTETOIF) { + if ((ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst)))) == NULL && + (ia = ifatoia(ifa_ifwithnet(sintosa(dst), 0))) == NULL) { + IPSTAT_INC(ips_noroute); + error = ENETUNREACH; + goto bad; + } + ifp = ia->ia_ifp; + ip->ip_ttl = 1; + isbroadcast = in_broadcast(dst->sin_addr, ifp); + } else if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) && + imo != NULL && imo->imo_multicast_ifp != NULL) { + /* + * Bypass the normal routing lookup for multicast + * packets if the interface is specified. + */ + ifp = imo->imo_multicast_ifp; + IFP_TO_IA(ifp, ia); + isbroadcast = 0; /* fool gcc */ + } else { + /* + * We want to do any cloning requested by the link layer, + * as this is probably required in all cases for correct + * operation (as it is for ARP). + */ + if (rte == NULL) { +#ifdef RADIX_MPATH + rtalloc_mpath_fib(ro, + ntohl(ip->ip_src.s_addr ^ ip->ip_dst.s_addr), + inp ? inp->inp_inc.inc_fibnum : M_GETFIB(m)); +#else + in_rtalloc_ign(ro, 0, + inp ? inp->inp_inc.inc_fibnum : M_GETFIB(m)); +#endif + rte = ro->ro_rt; + } + if (rte == NULL || + rte->rt_ifp == NULL || + !RT_LINK_IS_UP(rte->rt_ifp)) { +#ifdef IPSEC + /* + * There is no route for this packet, but it is + * possible that a matching SPD entry exists. + */ + no_route_but_check_spd = 1; + mtu = 0; /* Silence GCC warning. */ + goto sendit; +#endif + IPSTAT_INC(ips_noroute); + error = EHOSTUNREACH; + goto bad; + } + ia = ifatoia(rte->rt_ifa); + ifa_ref(&ia->ia_ifa); + ifp = rte->rt_ifp; + rte->rt_rmx.rmx_pksent++; + if (rte->rt_flags & RTF_GATEWAY) + dst = (struct sockaddr_in *)rte->rt_gateway; + if (rte->rt_flags & RTF_HOST) + isbroadcast = (rte->rt_flags & RTF_BROADCAST); + else + isbroadcast = in_broadcast(dst->sin_addr, ifp); + } + /* + * Calculate MTU. If we have a route that is up, use that, + * otherwise use the interface's MTU. + */ + if (rte != NULL && (rte->rt_flags & (RTF_UP|RTF_HOST))) { + /* + * This case can happen if the user changed the MTU + * of an interface after enabling IP on it. Because + * most netifs don't keep track of routes pointing to + * them, there is no way for one to update all its + * routes when the MTU is changed. + */ + if (rte->rt_rmx.rmx_mtu > ifp->if_mtu) + rte->rt_rmx.rmx_mtu = ifp->if_mtu; + mtu = rte->rt_rmx.rmx_mtu; + } else { + mtu = ifp->if_mtu; + } + if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) { + m->m_flags |= M_MCAST; + /* + * IP destination address is multicast. Make sure "dst" + * still points to the address in "ro". (It may have been + * changed to point to a gateway address, above.) + */ + dst = (struct sockaddr_in *)&ro->ro_dst; + /* + * See if the caller provided any multicast options + */ + if (imo != NULL) { + ip->ip_ttl = imo->imo_multicast_ttl; + if (imo->imo_multicast_vif != -1) + ip->ip_src.s_addr = + ip_mcast_src ? + ip_mcast_src(imo->imo_multicast_vif) : + INADDR_ANY; + } else + ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL; + /* + * Confirm that the outgoing interface supports multicast. + */ + if ((imo == NULL) || (imo->imo_multicast_vif == -1)) { + if ((ifp->if_flags & IFF_MULTICAST) == 0) { + IPSTAT_INC(ips_noroute); + error = ENETUNREACH; + goto bad; + } + } + /* + * If source address not specified yet, use address + * of outgoing interface. + */ + if (ip->ip_src.s_addr == INADDR_ANY) { + /* Interface may have no addresses. */ + if (ia != NULL) + ip->ip_src = IA_SIN(ia)->sin_addr; + } + + if ((imo == NULL && in_mcast_loop) || + (imo && imo->imo_multicast_loop)) { + /* + * Loop back multicast datagram if not expressly + * forbidden to do so, even if we are not a member + * of the group; ip_input() will filter it later, + * thus deferring a hash lookup and mutex acquisition + * at the expense of a cheap copy using m_copym(). + */ + ip_mloopback(ifp, m, dst, hlen); + } else { + /* + * If we are acting as a multicast router, perform + * multicast forwarding as if the packet had just + * arrived on the interface to which we are about + * to send. The multicast forwarding function + * recursively calls this function, using the + * IP_FORWARDING flag to prevent infinite recursion. + * + * Multicasts that are looped back by ip_mloopback(), + * above, will be forwarded by the ip_input() routine, + * if necessary. + */ + if (V_ip_mrouter && (flags & IP_FORWARDING) == 0) { + /* + * If rsvp daemon is not running, do not + * set ip_moptions. This ensures that the packet + * is multicast and not just sent down one link + * as prescribed by rsvpd. + */ + if (!V_rsvp_on) + imo = NULL; + if (ip_mforward && + ip_mforward(ip, ifp, m, imo) != 0) { + m_freem(m); + goto done; + } + } + } + + /* + * Multicasts with a time-to-live of zero may be looped- + * back, above, but must not be transmitted on a network. + * Also, multicasts addressed to the loopback interface + * are not sent -- the above call to ip_mloopback() will + * loop back a copy. ip_input() will drop the copy if + * this host does not belong to the destination group on + * the loopback interface. + */ + if (ip->ip_ttl == 0 || ifp->if_flags & IFF_LOOPBACK) { + m_freem(m); + goto done; + } + + goto sendit; + } + + /* + * If the source address is not specified yet, use the address + * of the outoing interface. + */ + if (ip->ip_src.s_addr == INADDR_ANY) { + /* Interface may have no addresses. */ + if (ia != NULL) { + ip->ip_src = IA_SIN(ia)->sin_addr; + } + } + + /* + * Verify that we have any chance at all of being able to queue the + * packet or packet fragments, unless ALTQ is enabled on the given + * interface in which case packetdrop should be done by queueing. + */ +#ifdef ALTQ + if ((!ALTQ_IS_ENABLED(&ifp->if_snd)) && + ((ifp->if_snd.ifq_len + ip->ip_len / mtu + 1) >= + ifp->if_snd.ifq_maxlen)) +#else + if ((ifp->if_snd.ifq_len + ip->ip_len / mtu + 1) >= + ifp->if_snd.ifq_maxlen) +#endif /* ALTQ */ + { + error = ENOBUFS; + IPSTAT_INC(ips_odropped); + ifp->if_snd.ifq_drops += (ip->ip_len / ifp->if_mtu + 1); + goto bad; + } + + /* + * Look for broadcast address and + * verify user is allowed to send + * such a packet. + */ + if (isbroadcast) { + if ((ifp->if_flags & IFF_BROADCAST) == 0) { + error = EADDRNOTAVAIL; + goto bad; + } + if ((flags & IP_ALLOWBROADCAST) == 0) { + error = EACCES; + goto bad; + } + /* don't allow broadcast messages to be fragmented */ + if (ip->ip_len > mtu) { + error = EMSGSIZE; + goto bad; + } + m->m_flags |= M_BCAST; + } else { + m->m_flags &= ~M_BCAST; + } + +sendit: +#ifdef IPSEC + switch(ip_ipsec_output(&m, inp, &flags, &error, &ifp)) { + case 1: + goto bad; + case -1: + goto done; + case 0: + default: + break; /* Continue with packet processing. */ + } + /* + * Check if there was a route for this packet; return error if not. + */ + if (no_route_but_check_spd) { + IPSTAT_INC(ips_noroute); + error = EHOSTUNREACH; + goto bad; + } + /* Update variables that are affected by ipsec4_output(). */ + ip = mtod(m, struct ip *); + hlen = ip->ip_hl << 2; +#endif /* IPSEC */ + + /* Jump over all PFIL processing if hooks are not active. */ + if (!PFIL_HOOKED(&V_inet_pfil_hook)) + goto passout; + + /* Run through list of hooks for output packets. */ + odst.s_addr = ip->ip_dst.s_addr; + error = pfil_run_hooks(&V_inet_pfil_hook, &m, ifp, PFIL_OUT, inp); + if (error != 0 || m == NULL) + goto done; + + ip = mtod(m, struct ip *); + + /* See if destination IP address was changed by packet filter. */ + if (odst.s_addr != ip->ip_dst.s_addr) { + m->m_flags |= M_SKIP_FIREWALL; + /* If destination is now ourself drop to ip_input(). */ + if (in_localip(ip->ip_dst)) { + m->m_flags |= M_FASTFWD_OURS; + if (m->m_pkthdr.rcvif == NULL) + m->m_pkthdr.rcvif = V_loif; + if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { + m->m_pkthdr.csum_flags |= + CSUM_DATA_VALID | CSUM_PSEUDO_HDR; + m->m_pkthdr.csum_data = 0xffff; + } + m->m_pkthdr.csum_flags |= + CSUM_IP_CHECKED | CSUM_IP_VALID; +#ifdef SCTP + if (m->m_pkthdr.csum_flags & CSUM_SCTP) + m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID; +#endif + error = netisr_queue(NETISR_IP, m); + goto done; + } else + goto again; /* Redo the routing table lookup. */ + } + +#ifdef IPFIREWALL_FORWARD + /* See if local, if yes, send it to netisr with IP_FASTFWD_OURS. */ + if (m->m_flags & M_FASTFWD_OURS) { + if (m->m_pkthdr.rcvif == NULL) + m->m_pkthdr.rcvif = V_loif; + if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { + m->m_pkthdr.csum_flags |= + CSUM_DATA_VALID | CSUM_PSEUDO_HDR; + m->m_pkthdr.csum_data = 0xffff; + } +#ifdef SCTP + if (m->m_pkthdr.csum_flags & CSUM_SCTP) + m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID; +#endif + m->m_pkthdr.csum_flags |= + CSUM_IP_CHECKED | CSUM_IP_VALID; + + error = netisr_queue(NETISR_IP, m); + goto done; + } + /* Or forward to some other address? */ + fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL); + if (fwd_tag) { + dst = (struct sockaddr_in *)&ro->ro_dst; + bcopy((fwd_tag+1), dst, sizeof(struct sockaddr_in)); + m->m_flags |= M_SKIP_FIREWALL; + m_tag_delete(m, fwd_tag); + goto again; + } +#endif /* IPFIREWALL_FORWARD */ + +passout: + /* 127/8 must not appear on wire - RFC1122. */ + if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET || + (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) { + if ((ifp->if_flags & IFF_LOOPBACK) == 0) { + IPSTAT_INC(ips_badaddr); + error = EADDRNOTAVAIL; + goto bad; + } + } + + m->m_pkthdr.csum_flags |= CSUM_IP; + sw_csum = m->m_pkthdr.csum_flags & ~ifp->if_hwassist; + if (sw_csum & CSUM_DELAY_DATA) { + in_delayed_cksum(m); + sw_csum &= ~CSUM_DELAY_DATA; + } +#ifdef SCTP + if (sw_csum & CSUM_SCTP) { + sctp_delayed_cksum(m, (uint32_t)(ip->ip_hl << 2)); + sw_csum &= ~CSUM_SCTP; + } +#endif + m->m_pkthdr.csum_flags &= ifp->if_hwassist; + + /* + * If small enough for interface, or the interface will take + * care of the fragmentation for us, we can just send directly. + */ + if (ip->ip_len <= mtu || + (m->m_pkthdr.csum_flags & ifp->if_hwassist & CSUM_TSO) != 0 || + ((ip->ip_off & IP_DF) == 0 && (ifp->if_hwassist & CSUM_FRAGMENT))) { + ip->ip_len = htons(ip->ip_len); + ip->ip_off = htons(ip->ip_off); + ip->ip_sum = 0; + if (sw_csum & CSUM_DELAY_IP) + ip->ip_sum = in_cksum(m, hlen); + + /* + * Record statistics for this interface address. + * With CSUM_TSO the byte/packet count will be slightly + * incorrect because we count the IP+TCP headers only + * once instead of for every generated packet. + */ + if (!(flags & IP_FORWARDING) && ia) { + if (m->m_pkthdr.csum_flags & CSUM_TSO) + ia->ia_ifa.if_opackets += + m->m_pkthdr.len / m->m_pkthdr.tso_segsz; + else + ia->ia_ifa.if_opackets++; + ia->ia_ifa.if_obytes += m->m_pkthdr.len; + } +#ifdef MBUF_STRESS_TEST + if (mbuf_frag_size && m->m_pkthdr.len > mbuf_frag_size) + m = m_fragment(m, M_DONTWAIT, mbuf_frag_size); +#endif + /* + * Reset layer specific mbuf flags + * to avoid confusing lower layers. + */ + m->m_flags &= ~(M_PROTOFLAGS); + error = (*ifp->if_output)(ifp, m, + (struct sockaddr *)dst, ro); + goto done; + } + + /* Balk when DF bit is set or the interface didn't support TSO. */ + if ((ip->ip_off & IP_DF) || (m->m_pkthdr.csum_flags & CSUM_TSO)) { + error = EMSGSIZE; + IPSTAT_INC(ips_cantfrag); + goto bad; + } + + /* + * Too large for interface; fragment if possible. If successful, + * on return, m will point to a list of packets to be sent. + */ + error = ip_fragment(ip, &m, mtu, ifp->if_hwassist, sw_csum); + if (error) + goto bad; + for (; m; m = m0) { + m0 = m->m_nextpkt; + m->m_nextpkt = 0; + if (error == 0) { + /* Record statistics for this interface address. */ + if (ia != NULL) { + ia->ia_ifa.if_opackets++; + ia->ia_ifa.if_obytes += m->m_pkthdr.len; + } + /* + * Reset layer specific mbuf flags + * to avoid confusing upper layers. + */ + m->m_flags &= ~(M_PROTOFLAGS); + + error = (*ifp->if_output)(ifp, m, + (struct sockaddr *)dst, ro); + } else + m_freem(m); + } + + if (error == 0) + IPSTAT_INC(ips_fragmented); + +done: + if (ro == &iproute && ro->ro_rt && !nortfree) { + RTFREE(ro->ro_rt); + } + if (ia != NULL) + ifa_free(&ia->ia_ifa); + return (error); +bad: + m_freem(m); + goto done; +} + +/* + * Create a chain of fragments which fit the given mtu. m_frag points to the + * mbuf to be fragmented; on return it points to the chain with the fragments. + * Return 0 if no error. If error, m_frag may contain a partially built + * chain of fragments that should be freed by the caller. + * + * if_hwassist_flags is the hw offload capabilities (see if_data.ifi_hwassist) + * sw_csum contains the delayed checksums flags (e.g., CSUM_DELAY_IP). + */ +int +ip_fragment(struct ip *ip, struct mbuf **m_frag, int mtu, + u_long if_hwassist_flags, int sw_csum) +{ + int error = 0; + int hlen = ip->ip_hl << 2; + int len = (mtu - hlen) & ~7; /* size of payload in each fragment */ + int off; + struct mbuf *m0 = *m_frag; /* the original packet */ + int firstlen; + struct mbuf **mnext; + int nfrags; + + if (ip->ip_off & IP_DF) { /* Fragmentation not allowed */ + IPSTAT_INC(ips_cantfrag); + return EMSGSIZE; + } + + /* + * Must be able to put at least 8 bytes per fragment. + */ + if (len < 8) + return EMSGSIZE; + + /* + * If the interface will not calculate checksums on + * fragmented packets, then do it here. + */ + if (m0->m_pkthdr.csum_flags & CSUM_DELAY_DATA && + (if_hwassist_flags & CSUM_IP_FRAGS) == 0) { + in_delayed_cksum(m0); + m0->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; + } +#ifdef SCTP + if (m0->m_pkthdr.csum_flags & CSUM_SCTP && + (if_hwassist_flags & CSUM_IP_FRAGS) == 0) { + sctp_delayed_cksum(m0, hlen); + m0->m_pkthdr.csum_flags &= ~CSUM_SCTP; + } +#endif + if (len > PAGE_SIZE) { + /* + * Fragment large datagrams such that each segment + * contains a multiple of PAGE_SIZE amount of data, + * plus headers. This enables a receiver to perform + * page-flipping zero-copy optimizations. + * + * XXX When does this help given that sender and receiver + * could have different page sizes, and also mtu could + * be less than the receiver's page size ? + */ + int newlen; + struct mbuf *m; + + for (m = m0, off = 0; m && (off+m->m_len) <= mtu; m = m->m_next) + off += m->m_len; + + /* + * firstlen (off - hlen) must be aligned on an + * 8-byte boundary + */ + if (off < hlen) + goto smart_frag_failure; + off = ((off - hlen) & ~7) + hlen; + newlen = (~PAGE_MASK) & mtu; + if ((newlen + sizeof (struct ip)) > mtu) { + /* we failed, go back the default */ +smart_frag_failure: + newlen = len; + off = hlen + len; + } + len = newlen; + + } else { + off = hlen + len; + } + + firstlen = off - hlen; + mnext = &m0->m_nextpkt; /* pointer to next packet */ + + /* + * Loop through length of segment after first fragment, + * make new header and copy data of each part and link onto chain. + * Here, m0 is the original packet, m is the fragment being created. + * The fragments are linked off the m_nextpkt of the original + * packet, which after processing serves as the first fragment. + */ + for (nfrags = 1; off < ip->ip_len; off += len, nfrags++) { + struct ip *mhip; /* ip header on the fragment */ + struct mbuf *m; + int mhlen = sizeof (struct ip); + + MGETHDR(m, M_DONTWAIT, MT_DATA); + if (m == NULL) { + error = ENOBUFS; + IPSTAT_INC(ips_odropped); + goto done; + } + m->m_flags |= (m0->m_flags & M_MCAST) | M_FRAG; + /* + * In the first mbuf, leave room for the link header, then + * copy the original IP header including options. The payload + * goes into an additional mbuf chain returned by m_copym(). + */ + m->m_data += max_linkhdr; + mhip = mtod(m, struct ip *); + *mhip = *ip; + if (hlen > sizeof (struct ip)) { + mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip); + mhip->ip_v = IPVERSION; + mhip->ip_hl = mhlen >> 2; + } + m->m_len = mhlen; + /* XXX do we need to add ip->ip_off below ? */ + mhip->ip_off = ((off - hlen) >> 3) + ip->ip_off; + if (off + len >= ip->ip_len) { /* last fragment */ + len = ip->ip_len - off; + m->m_flags |= M_LASTFRAG; + } else + mhip->ip_off |= IP_MF; + mhip->ip_len = htons((u_short)(len + mhlen)); + m->m_next = m_copym(m0, off, len, M_DONTWAIT); + if (m->m_next == NULL) { /* copy failed */ + m_free(m); + error = ENOBUFS; /* ??? */ + IPSTAT_INC(ips_odropped); + goto done; + } + m->m_pkthdr.len = mhlen + len; + m->m_pkthdr.rcvif = NULL; +#ifdef MAC + mac_netinet_fragment(m0, m); +#endif + m->m_pkthdr.csum_flags = m0->m_pkthdr.csum_flags; + mhip->ip_off = htons(mhip->ip_off); + mhip->ip_sum = 0; + if (sw_csum & CSUM_DELAY_IP) + mhip->ip_sum = in_cksum(m, mhlen); + *mnext = m; + mnext = &m->m_nextpkt; + } + IPSTAT_ADD(ips_ofragments, nfrags); + + /* set first marker for fragment chain */ + m0->m_flags |= M_FIRSTFRAG | M_FRAG; + m0->m_pkthdr.csum_data = nfrags; + + /* + * Update first fragment by trimming what's been copied out + * and updating header. + */ + m_adj(m0, hlen + firstlen - ip->ip_len); + m0->m_pkthdr.len = hlen + firstlen; + ip->ip_len = htons((u_short)m0->m_pkthdr.len); + ip->ip_off |= IP_MF; + ip->ip_off = htons(ip->ip_off); + ip->ip_sum = 0; + if (sw_csum & CSUM_DELAY_IP) + ip->ip_sum = in_cksum(m0, hlen); + +done: + *m_frag = m0; + return error; +} + +void +in_delayed_cksum(struct mbuf *m) +{ + struct ip *ip; + u_short csum, offset; + + ip = mtod(m, struct ip *); + offset = ip->ip_hl << 2 ; + csum = in_cksum_skip(m, ip->ip_len, offset); + if (m->m_pkthdr.csum_flags & CSUM_UDP && csum == 0) + csum = 0xffff; + offset += m->m_pkthdr.csum_data; /* checksum offset */ + + if (offset + sizeof(u_short) > m->m_len) { + printf("delayed m_pullup, m->len: %d off: %d p: %d\n", + m->m_len, offset, ip->ip_p); + /* + * XXX + * this shouldn't happen, but if it does, the + * correct behavior may be to insert the checksum + * in the appropriate next mbuf in the chain. + */ + return; + } + *(u_short *)(m->m_data + offset) = csum; +} + +/* + * IP socket option processing. + */ +int +ip_ctloutput(struct socket *so, struct sockopt *sopt) +{ + struct inpcb *inp = sotoinpcb(so); + int error, optval; + + error = optval = 0; + if (sopt->sopt_level != IPPROTO_IP) { + if ((sopt->sopt_level == SOL_SOCKET) && + (sopt->sopt_name == SO_SETFIB)) { + inp->inp_inc.inc_fibnum = so->so_fibnum; + return (0); + } + return (EINVAL); + } + + switch (sopt->sopt_dir) { + case SOPT_SET: + switch (sopt->sopt_name) { + case IP_OPTIONS: +#ifdef notyet + case IP_RETOPTS: +#endif + { + struct mbuf *m; + if (sopt->sopt_valsize > MLEN) { + error = EMSGSIZE; + break; + } + MGET(m, sopt->sopt_td ? M_WAIT : M_DONTWAIT, MT_DATA); + if (m == NULL) { + error = ENOBUFS; + break; + } + m->m_len = sopt->sopt_valsize; + error = sooptcopyin(sopt, mtod(m, char *), m->m_len, + m->m_len); + if (error) { + m_free(m); + break; + } + INP_WLOCK(inp); + error = ip_pcbopts(inp, sopt->sopt_name, m); + INP_WUNLOCK(inp); + return (error); + } + + case IP_BINDANY: + if (sopt->sopt_td != NULL) { + error = priv_check(sopt->sopt_td, + PRIV_NETINET_BINDANY); + if (error) + break; + } + /* FALLTHROUGH */ + case IP_TOS: + case IP_TTL: + case IP_MINTTL: + case IP_RECVOPTS: + case IP_RECVRETOPTS: + case IP_RECVDSTADDR: + case IP_RECVTTL: + case IP_RECVIF: + case IP_FAITH: + case IP_ONESBCAST: + case IP_DONTFRAG: + error = sooptcopyin(sopt, &optval, sizeof optval, + sizeof optval); + if (error) + break; + + switch (sopt->sopt_name) { + case IP_TOS: + inp->inp_ip_tos = optval; + break; + + case IP_TTL: + inp->inp_ip_ttl = optval; + break; + + case IP_MINTTL: + if (optval >= 0 && optval <= MAXTTL) + inp->inp_ip_minttl = optval; + else + error = EINVAL; + break; + +#define OPTSET(bit) do { \ + INP_WLOCK(inp); \ + if (optval) \ + inp->inp_flags |= bit; \ + else \ + inp->inp_flags &= ~bit; \ + INP_WUNLOCK(inp); \ +} while (0) + + case IP_RECVOPTS: + OPTSET(INP_RECVOPTS); + break; + + case IP_RECVRETOPTS: + OPTSET(INP_RECVRETOPTS); + break; + + case IP_RECVDSTADDR: + OPTSET(INP_RECVDSTADDR); + break; + + case IP_RECVTTL: + OPTSET(INP_RECVTTL); + break; + + case IP_RECVIF: + OPTSET(INP_RECVIF); + break; + + case IP_FAITH: + OPTSET(INP_FAITH); + break; + + case IP_ONESBCAST: + OPTSET(INP_ONESBCAST); + break; + case IP_DONTFRAG: + OPTSET(INP_DONTFRAG); + break; + case IP_BINDANY: + OPTSET(INP_BINDANY); + break; + } + break; +#undef OPTSET + + /* + * Multicast socket options are processed by the in_mcast + * module. + */ + case IP_MULTICAST_IF: + case IP_MULTICAST_VIF: + case IP_MULTICAST_TTL: + case IP_MULTICAST_LOOP: + case IP_ADD_MEMBERSHIP: + case IP_DROP_MEMBERSHIP: + case IP_ADD_SOURCE_MEMBERSHIP: + case IP_DROP_SOURCE_MEMBERSHIP: + case IP_BLOCK_SOURCE: + case IP_UNBLOCK_SOURCE: + case IP_MSFILTER: + case MCAST_JOIN_GROUP: + case MCAST_LEAVE_GROUP: + case MCAST_JOIN_SOURCE_GROUP: + case MCAST_LEAVE_SOURCE_GROUP: + case MCAST_BLOCK_SOURCE: + case MCAST_UNBLOCK_SOURCE: + error = inp_setmoptions(inp, sopt); + break; + + case IP_PORTRANGE: + error = sooptcopyin(sopt, &optval, sizeof optval, + sizeof optval); + if (error) + break; + + INP_WLOCK(inp); + switch (optval) { + case IP_PORTRANGE_DEFAULT: + inp->inp_flags &= ~(INP_LOWPORT); + inp->inp_flags &= ~(INP_HIGHPORT); + break; + + case IP_PORTRANGE_HIGH: + inp->inp_flags &= ~(INP_LOWPORT); + inp->inp_flags |= INP_HIGHPORT; + break; + + case IP_PORTRANGE_LOW: + inp->inp_flags &= ~(INP_HIGHPORT); + inp->inp_flags |= INP_LOWPORT; + break; + + default: + error = EINVAL; + break; + } + INP_WUNLOCK(inp); + break; + +#ifdef IPSEC + case IP_IPSEC_POLICY: + { + caddr_t req; + struct mbuf *m; + + if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */ + break; + if ((error = soopt_mcopyin(sopt, m)) != 0) /* XXX */ + break; + req = mtod(m, caddr_t); + error = ipsec_set_policy(inp, sopt->sopt_name, req, + m->m_len, (sopt->sopt_td != NULL) ? + sopt->sopt_td->td_ucred : NULL); + m_freem(m); + break; + } +#endif /* IPSEC */ + + default: + error = ENOPROTOOPT; + break; + } + break; + + case SOPT_GET: + switch (sopt->sopt_name) { + case IP_OPTIONS: + case IP_RETOPTS: + if (inp->inp_options) + error = sooptcopyout(sopt, + mtod(inp->inp_options, + char *), + inp->inp_options->m_len); + else + sopt->sopt_valsize = 0; + break; + + case IP_TOS: + case IP_TTL: + case IP_MINTTL: + case IP_RECVOPTS: + case IP_RECVRETOPTS: + case IP_RECVDSTADDR: + case IP_RECVTTL: + case IP_RECVIF: + case IP_PORTRANGE: + case IP_FAITH: + case IP_ONESBCAST: + case IP_DONTFRAG: + case IP_BINDANY: + switch (sopt->sopt_name) { + + case IP_TOS: + optval = inp->inp_ip_tos; + break; + + case IP_TTL: + optval = inp->inp_ip_ttl; + break; + + case IP_MINTTL: + optval = inp->inp_ip_minttl; + break; + +#define OPTBIT(bit) (inp->inp_flags & bit ? 1 : 0) + + case IP_RECVOPTS: + optval = OPTBIT(INP_RECVOPTS); + break; + + case IP_RECVRETOPTS: + optval = OPTBIT(INP_RECVRETOPTS); + break; + + case IP_RECVDSTADDR: + optval = OPTBIT(INP_RECVDSTADDR); + break; + + case IP_RECVTTL: + optval = OPTBIT(INP_RECVTTL); + break; + + case IP_RECVIF: + optval = OPTBIT(INP_RECVIF); + break; + + case IP_PORTRANGE: + if (inp->inp_flags & INP_HIGHPORT) + optval = IP_PORTRANGE_HIGH; + else if (inp->inp_flags & INP_LOWPORT) + optval = IP_PORTRANGE_LOW; + else + optval = 0; + break; + + case IP_FAITH: + optval = OPTBIT(INP_FAITH); + break; + + case IP_ONESBCAST: + optval = OPTBIT(INP_ONESBCAST); + break; + case IP_DONTFRAG: + optval = OPTBIT(INP_DONTFRAG); + break; + case IP_BINDANY: + optval = OPTBIT(INP_BINDANY); + break; + } + error = sooptcopyout(sopt, &optval, sizeof optval); + break; + + /* + * Multicast socket options are processed by the in_mcast + * module. + */ + case IP_MULTICAST_IF: + case IP_MULTICAST_VIF: + case IP_MULTICAST_TTL: + case IP_MULTICAST_LOOP: + case IP_MSFILTER: + error = inp_getmoptions(inp, sopt); + break; + +#ifdef IPSEC + case IP_IPSEC_POLICY: + { + struct mbuf *m = NULL; + caddr_t req = NULL; + size_t len = 0; + + if (m != 0) { + req = mtod(m, caddr_t); + len = m->m_len; + } + error = ipsec_get_policy(sotoinpcb(so), req, len, &m); + if (error == 0) + error = soopt_mcopyout(sopt, m); /* XXX */ + if (error == 0) + m_freem(m); + break; + } +#endif /* IPSEC */ + + default: + error = ENOPROTOOPT; + break; + } + break; + } + return (error); +} + +/* + * Routine called from ip_output() to loop back a copy of an IP multicast + * packet to the input queue of a specified interface. Note that this + * calls the output routine of the loopback "driver", but with an interface + * pointer that might NOT be a loopback interface -- evil, but easier than + * replicating that code here. + */ +static void +ip_mloopback(struct ifnet *ifp, struct mbuf *m, struct sockaddr_in *dst, + int hlen) +{ + register struct ip *ip; + struct mbuf *copym; + + /* + * Make a deep copy of the packet because we're going to + * modify the pack in order to generate checksums. + */ + copym = m_dup(m, M_DONTWAIT); + if (copym != NULL && (copym->m_flags & M_EXT || copym->m_len < hlen)) + copym = m_pullup(copym, hlen); + if (copym != NULL) { + /* If needed, compute the checksum and mark it as valid. */ + if (copym->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { + in_delayed_cksum(copym); + copym->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; + copym->m_pkthdr.csum_flags |= + CSUM_DATA_VALID | CSUM_PSEUDO_HDR; + copym->m_pkthdr.csum_data = 0xffff; + } + /* + * We don't bother to fragment if the IP length is greater + * than the interface's MTU. Can this possibly matter? + */ + ip = mtod(copym, struct ip *); + ip->ip_len = htons(ip->ip_len); + ip->ip_off = htons(ip->ip_off); + ip->ip_sum = 0; + ip->ip_sum = in_cksum(copym, hlen); +#if 1 /* XXX */ + if (dst->sin_family != AF_INET) { + printf("ip_mloopback: bad address family %d\n", + dst->sin_family); + dst->sin_family = AF_INET; + } +#endif + if_simloop(ifp, copym, dst->sin_family, 0); + } +} |