Index: stable/10/share/man/man4/icmp.4 =================================================================== --- stable/10/share/man/man4/icmp.4 (revision 281608) +++ stable/10/share/man/man4/icmp.4 (revision 281609) @@ -1,254 +1,258 @@ .\" Copyright (c) 1986, 1991, 1993 .\" The Regents of the University of California. All rights reserved. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in the .\" documentation and/or other materials provided with the distribution. .\" 3. All advertising materials mentioning features or use of this software .\" must display the following acknowledgement: .\" This product includes software developed by the University of .\" California, Berkeley and its contributors. .\" 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. .\" .\" @(#)icmp.4 8.1 (Berkeley) 6/5/93 .\" $FreeBSD$ .\" -.Dd February 9, 2007 +.Dd September 30, 2014 .Dt ICMP 4 .Os .Sh NAME .Nm icmp .Nd Internet Control Message Protocol .Sh SYNOPSIS .In sys/types.h .In sys/socket.h .In netinet/in.h .Ft int .Fn socket AF_INET SOCK_RAW proto .Sh DESCRIPTION .Tn ICMP is the error and control message protocol used by .Tn IP and the Internet protocol family. It may be accessed through a .Dq raw socket for network monitoring and diagnostic functions. The .Fa proto parameter to the socket call to create an .Tn ICMP socket is obtained from .Xr getprotobyname 3 . .Tn ICMP sockets are connectionless, and are normally used with the .Xr sendto 2 and .Xr recvfrom 2 calls, though the .Xr connect 2 call may also be used to fix the destination for future packets (in which case the .Xr read 2 or .Xr recv 2 and .Xr write 2 or .Xr send 2 system calls may be used). .Pp Outgoing packets automatically have an .Tn IP header prepended to them (based on the destination address). Incoming packets are received with the .Tn IP header and options intact. .Ss Types ICMP messages are classified according to the type and code fields present in the ICMP header. The abbreviations for the types and codes may be used in rules in .Xr pf.conf 5 . The following types are defined: .Bl -column x xxxxxxxxxxxx -offset indent .It Sy Num Ta Sy Abbrev. Ta Sy Description .It 0 Ta echorep Ta "Echo reply" .It 3 Ta unreach Ta "Destination unreachable" .It 4 Ta squench Ta "Packet loss, slow down" .It 5 Ta redir Ta "Shorter route exists" .It 6 Ta althost Ta "Alternate host address" .It 8 Ta echoreq Ta "Echo request" .It 9 Ta routeradv Ta "Router advertisement" .It 10 Ta routersol Ta "Router solicitation" .It 11 Ta timex Ta "Time exceeded" .It 12 Ta paramprob Ta "Invalid IP header" .It 13 Ta timereq Ta "Timestamp request" .It 14 Ta timerep Ta "Timestamp reply" .It 15 Ta inforeq Ta "Information request" .It 16 Ta inforep Ta "Information reply" .It 17 Ta maskreq Ta "Address mask request" .It 18 Ta maskrep Ta "Address mask reply" .It 30 Ta trace Ta Traceroute .It 31 Ta dataconv Ta "Data conversion problem" .It 32 Ta mobredir Ta "Mobile host redirection" .It 33 Ta ipv6-where Ta "IPv6 where-are-you" .It 34 Ta ipv6-here Ta "IPv6 i-am-here" .It 35 Ta mobregreq Ta "Mobile registration request" .It 36 Ta mobregrep Ta "Mobile registration reply" .It 39 Ta skip Ta SKIP .It 40 Ta photuris Ta Photuris .El .Pp The following codes are defined: .Bl -column x xxxxxxxxxxxx xxxxxxxx -offset indent .It Sy Num Ta Sy Abbrev. Ta Sy Type Ta Sy Description .It 0 Ta net-unr Ta unreach Ta "Network unreachable" .It 1 Ta host-unr Ta unreach Ta "Host unreachable" .It 2 Ta proto-unr Ta unreach Ta "Protocol unreachable" .It 3 Ta port-unr Ta unreach Ta "Port unreachable" .It 4 Ta needfrag Ta unreach Ta "Fragmentation needed but DF bit set" .It 5 Ta srcfail Ta unreach Ta "Source routing failed" .It 6 Ta net-unk Ta unreach Ta "Network unknown" .It 7 Ta host-unk Ta unreach Ta "Host unknown" .It 8 Ta isolate Ta unreach Ta "Host isolated" .It 9 Ta net-prohib Ta unreach Ta "Network administratively prohibited" .It 10 Ta host-prohib Ta unreach Ta "Host administratively prohibited" .It 11 Ta net-tos Ta unreach Ta "Invalid TOS for network" .It 12 Ta host-tos Ta unreach Ta "Invalid TOS for host" .It 13 Ta filter-prohib Ta unreach Ta "Prohibited access" .It 14 Ta host-preced Ta unreach Ta "Precedence violation" .It 15 Ta cutoff-preced Ta unreach Ta "Precedence cutoff" .It 0 Ta redir-net Ta redir Ta "Shorter route for network" .It 1 Ta redir-host Ta redir Ta "Shorter route for host" .It 2 Ta redir-tos-net Ta redir Ta "Shorter route for TOS and network" .It 3 Ta redir-tos-host Ta redir Ta "Shorter route for TOS and host" .It 0 Ta normal-adv Ta routeradv Ta "Normal advertisement" .It 16 Ta common-adv Ta routeradv Ta "Selective advertisement" .It 0 Ta transit Ta timex Ta "Time exceeded in transit" .It 1 Ta reassemb Ta timex Ta "Time exceeded in reassembly" .It 0 Ta badhead Ta paramprob Ta "Invalid option pointer" .It 1 Ta optmiss Ta paramprob Ta "Missing option" .It 2 Ta badlen Ta paramprob Ta "Invalid length" .It 1 Ta unknown-ind Ta photuris Ta "Unknown security index" .It 2 Ta auth-fail Ta photuris Ta "Authentication failed" .It 3 Ta decrypt-fail Ta photuris Ta "Decryption failed" .El .Ss MIB Variables The .Tn ICMP protocol implements a number of variables in the .Va net.inet.icmp branch of the .Xr sysctl 3 MIB. .Bl -tag -width ".Va icmplim_output" .It Va maskrepl .Pq Vt boolean Enable/disable replies to ICMP Address Mask Request packets. Defaults to false. .It Va maskfake .Pq Vt "unsigned integer" When .Va maskrepl is set and this value is non-zero, it will be used instead of the real address mask when the system replies to an ICMP Address Mask Request packet. Defaults to 0. .It Va icmplim .Pq Vt integer Bandwidth limit for ICMP replies in packets/second. Used when .Va icmplim_output is non-zero. Defaults to 200. .It Va icmplim_output .Pq Vt boolean Enable/disable bandwidth limiting of ICMP replies. Defaults to true. .It Va drop_redirect .Pq Vt boolean Enable/disable dropping of ICMP Redirect packets. Defaults to false. .It Va log_redirect .Pq Vt boolean Enable/disable logging of ICMP Redirect packets. Defaults to false. .It Va bmcastecho .Pq Vt boolean Enable/disable ICMP replies received via broadcast or multicast. Defaults to false. .It Va reply_src .Pq Vt str An interface name used for the ICMP reply source in response to packets which are not directly addressed to us. By default continue with normal source selection. .It Va reply_from_interface .Pq Vt boolean Use the IP address of the interface the packet came through in for responses to packets which are not directly addressed to us. If enabled, this rule is processed before all others. By default, continue with normal source selection. Enabling this option is particularly useful on routers because it makes external traceroutes show the actual path a packet has taken instead of the possibly different return path. .It Va quotelen .Pq Vt integer Number of bytes from original packet to quote in ICMP reply. This number is internally enforced to be at least 8 bytes (per RFC792) and at most the maximal space left in the ICMP reply mbuf. +.It Va tstamprepl +.Pq Vt boolean +Enable/disable replies to ICMP Timestamp packets. +Defaults to true. .El .Sh ERRORS A socket operation may fail with one of the following errors returned: .Bl -tag -width Er .It Bq Er EISCONN when trying to establish a connection on a socket which already has one, or when trying to send a datagram with the destination address specified and the socket is already connected; .It Bq Er ENOTCONN when trying to send a datagram, but no destination address is specified, and the socket has not been connected; .It Bq Er ENOBUFS when the system runs out of memory for an internal data structure; .It Bq Er EADDRNOTAVAIL when an attempt is made to create a socket with a network address for which no network interface exists. .El .Sh SEE ALSO .Xr recv 2 , .Xr send 2 , .Xr inet 4 , .Xr intro 4 , .Xr ip 4 , .Xr pf.conf 5 .Sh HISTORY The .Nm protocol appeared in .Bx 4.3 . Index: stable/10/sys/netinet/ip_icmp.c =================================================================== --- stable/10/sys/netinet/ip_icmp.c (revision 281608) +++ stable/10/sys/netinet/ip_icmp.c (revision 281609) @@ -1,1010 +1,1016 @@ /*- * Copyright (c) 1982, 1986, 1988, 1993 * The Regents of the University of California. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 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_icmp.c 8.2 (Berkeley) 1/4/94 */ #include __FBSDID("$FreeBSD$"); #include "opt_inet.h" #include "opt_ipsec.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef INET #ifdef IPSEC #include #include #endif #include #include #endif /* INET */ /* * ICMP routines: error generation, receive packet processing, and * routines to turnaround packets back to the originator, and * host table maintenance routines. */ static VNET_DEFINE(int, icmplim) = 200; #define V_icmplim VNET(icmplim) SYSCTL_VNET_INT(_net_inet_icmp, ICMPCTL_ICMPLIM, icmplim, CTLFLAG_RW, &VNET_NAME(icmplim), 0, "Maximum number of ICMP responses per second"); static VNET_DEFINE(int, icmplim_output) = 1; #define V_icmplim_output VNET(icmplim_output) SYSCTL_VNET_INT(_net_inet_icmp, OID_AUTO, icmplim_output, CTLFLAG_RW, &VNET_NAME(icmplim_output), 0, "Enable logging of ICMP response rate limiting"); #ifdef INET VNET_PCPUSTAT_DEFINE(struct icmpstat, icmpstat); VNET_PCPUSTAT_SYSINIT(icmpstat); SYSCTL_VNET_PCPUSTAT(_net_inet_icmp, ICMPCTL_STATS, stats, struct icmpstat, icmpstat, "ICMP statistics (struct icmpstat, netinet/icmp_var.h)"); #ifdef VIMAGE VNET_PCPUSTAT_SYSUNINIT(icmpstat); #endif /* VIMAGE */ static VNET_DEFINE(int, icmpmaskrepl) = 0; #define V_icmpmaskrepl VNET(icmpmaskrepl) SYSCTL_VNET_INT(_net_inet_icmp, ICMPCTL_MASKREPL, maskrepl, CTLFLAG_RW, &VNET_NAME(icmpmaskrepl), 0, "Reply to ICMP Address Mask Request packets."); static VNET_DEFINE(u_int, icmpmaskfake) = 0; #define V_icmpmaskfake VNET(icmpmaskfake) SYSCTL_VNET_UINT(_net_inet_icmp, OID_AUTO, maskfake, CTLFLAG_RW, &VNET_NAME(icmpmaskfake), 0, "Fake reply to ICMP Address Mask Request packets."); VNET_DEFINE(int, drop_redirect) = 0; static VNET_DEFINE(int, log_redirect) = 0; #define V_log_redirect VNET(log_redirect) SYSCTL_VNET_INT(_net_inet_icmp, OID_AUTO, log_redirect, CTLFLAG_RW, &VNET_NAME(log_redirect), 0, "Log ICMP redirects to the console"); static VNET_DEFINE(char, reply_src[IFNAMSIZ]); #define V_reply_src VNET(reply_src) SYSCTL_VNET_STRING(_net_inet_icmp, OID_AUTO, reply_src, CTLFLAG_RW, &VNET_NAME(reply_src), IFNAMSIZ, "icmp reply source for non-local packets."); static VNET_DEFINE(int, icmp_rfi) = 0; #define V_icmp_rfi VNET(icmp_rfi) SYSCTL_VNET_INT(_net_inet_icmp, OID_AUTO, reply_from_interface, CTLFLAG_RW, &VNET_NAME(icmp_rfi), 0, "ICMP reply from incoming interface for non-local packets"); static VNET_DEFINE(int, icmp_quotelen) = 8; #define V_icmp_quotelen VNET(icmp_quotelen) SYSCTL_VNET_INT(_net_inet_icmp, OID_AUTO, quotelen, CTLFLAG_RW, &VNET_NAME(icmp_quotelen), 0, "Number of bytes from original packet to quote in ICMP reply"); /* * ICMP broadcast echo sysctl */ static VNET_DEFINE(int, icmpbmcastecho) = 0; #define V_icmpbmcastecho VNET(icmpbmcastecho) SYSCTL_VNET_INT(_net_inet_icmp, OID_AUTO, bmcastecho, CTLFLAG_RW, &VNET_NAME(icmpbmcastecho), 0, ""); +static VNET_DEFINE(int, icmptstamprepl) = 1; +#define V_icmptstamprepl VNET(icmptstamprepl) +SYSCTL_INT(_net_inet_icmp, OID_AUTO, tstamprepl, CTLFLAG_RW, + &VNET_NAME(icmptstamprepl), 0, "Respond to ICMP Timestamp packets"); #ifdef ICMPPRINTFS int icmpprintfs = 0; #endif static void icmp_reflect(struct mbuf *); static void icmp_send(struct mbuf *, struct mbuf *); extern struct protosw inetsw[]; static int sysctl_net_icmp_drop_redir(SYSCTL_HANDLER_ARGS) { int error, new; int i; struct radix_node_head *rnh; new = V_drop_redirect; error = sysctl_handle_int(oidp, &new, 0, req); if (error == 0 && req->newptr) { new = (new != 0) ? 1 : 0; if (new == V_drop_redirect) return (0); for (i = 0; i < rt_numfibs; i++) { if ((rnh = rt_tables_get_rnh(i, AF_INET)) == NULL) continue; RADIX_NODE_HEAD_LOCK(rnh); in_setmatchfunc(rnh, new); RADIX_NODE_HEAD_UNLOCK(rnh); } V_drop_redirect = new; } return (error); } SYSCTL_VNET_PROC(_net_inet_icmp, OID_AUTO, drop_redirect, CTLTYPE_INT|CTLFLAG_RW, 0, 0, sysctl_net_icmp_drop_redir, "I", "Ignore ICMP redirects"); /* * Kernel module interface for updating icmpstat. The argument is an index * into icmpstat treated as an array of u_long. While this encodes the * general layout of icmpstat into the caller, it doesn't encode its * location, so that future changes to add, for example, per-CPU stats * support won't cause binary compatibility problems for kernel modules. */ void kmod_icmpstat_inc(int statnum) { counter_u64_add(VNET(icmpstat)[statnum], 1); } /* * Generate an error packet of type error * in response to bad packet ip. */ void icmp_error(struct mbuf *n, int type, int code, uint32_t dest, int mtu) { register struct ip *oip = mtod(n, struct ip *), *nip; register unsigned oiphlen = oip->ip_hl << 2; register struct icmp *icp; register struct mbuf *m; unsigned icmplen, icmpelen, nlen; KASSERT((u_int)type <= ICMP_MAXTYPE, ("%s: illegal ICMP type", __func__)); #ifdef ICMPPRINTFS if (icmpprintfs) printf("icmp_error(%p, %x, %d)\n", oip, type, code); #endif if (type != ICMP_REDIRECT) ICMPSTAT_INC(icps_error); /* * Don't send error: * if the original packet was encrypted. * if not the first fragment of message. * in response to a multicast or broadcast packet. * if the old packet protocol was an ICMP error message. */ if (n->m_flags & M_DECRYPTED) goto freeit; if (oip->ip_off & htons(~(IP_MF|IP_DF))) goto freeit; if (n->m_flags & (M_BCAST|M_MCAST)) goto freeit; if (oip->ip_p == IPPROTO_ICMP && type != ICMP_REDIRECT && n->m_len >= oiphlen + ICMP_MINLEN && !ICMP_INFOTYPE(((struct icmp *)((caddr_t)oip + oiphlen))->icmp_type)) { ICMPSTAT_INC(icps_oldicmp); goto freeit; } /* Drop if IP header plus 8 bytes is not contignous in first mbuf. */ if (oiphlen + 8 > n->m_len) goto freeit; /* * Calculate length to quote from original packet and * prevent the ICMP mbuf from overflowing. * Unfortunatly this is non-trivial since ip_forward() * sends us truncated packets. */ nlen = m_length(n, NULL); if (oip->ip_p == IPPROTO_TCP) { struct tcphdr *th; int tcphlen; if (oiphlen + sizeof(struct tcphdr) > n->m_len && n->m_next == NULL) goto stdreply; if (n->m_len < oiphlen + sizeof(struct tcphdr) && ((n = m_pullup(n, oiphlen + sizeof(struct tcphdr))) == NULL)) goto freeit; th = (struct tcphdr *)((caddr_t)oip + oiphlen); tcphlen = th->th_off << 2; if (tcphlen < sizeof(struct tcphdr)) goto freeit; if (ntohs(oip->ip_len) < oiphlen + tcphlen) goto freeit; if (oiphlen + tcphlen > n->m_len && n->m_next == NULL) goto stdreply; if (n->m_len < oiphlen + tcphlen && ((n = m_pullup(n, oiphlen + tcphlen)) == NULL)) goto freeit; icmpelen = max(tcphlen, min(V_icmp_quotelen, ntohs(oip->ip_len) - oiphlen)); } else stdreply: icmpelen = max(8, min(V_icmp_quotelen, ntohs(oip->ip_len) - oiphlen)); icmplen = min(oiphlen + icmpelen, nlen); if (icmplen < sizeof(struct ip)) goto freeit; if (MHLEN > sizeof(struct ip) + ICMP_MINLEN + icmplen) m = m_gethdr(M_NOWAIT, MT_DATA); else m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); if (m == NULL) goto freeit; #ifdef MAC mac_netinet_icmp_reply(n, m); #endif icmplen = min(icmplen, M_TRAILINGSPACE(m) - sizeof(struct ip) - ICMP_MINLEN); m_align(m, ICMP_MINLEN + icmplen); m->m_len = ICMP_MINLEN + icmplen; /* XXX MRT make the outgoing packet use the same FIB * that was associated with the incoming packet */ M_SETFIB(m, M_GETFIB(n)); icp = mtod(m, struct icmp *); ICMPSTAT_INC(icps_outhist[type]); icp->icmp_type = type; if (type == ICMP_REDIRECT) icp->icmp_gwaddr.s_addr = dest; else { icp->icmp_void = 0; /* * The following assignments assume an overlay with the * just zeroed icmp_void field. */ if (type == ICMP_PARAMPROB) { icp->icmp_pptr = code; code = 0; } else if (type == ICMP_UNREACH && code == ICMP_UNREACH_NEEDFRAG && mtu) { icp->icmp_nextmtu = htons(mtu); } } icp->icmp_code = code; /* * Copy the quotation into ICMP message and * convert quoted IP header back to network representation. */ m_copydata(n, 0, icmplen, (caddr_t)&icp->icmp_ip); nip = &icp->icmp_ip; /* * Set up ICMP message mbuf and copy old IP header (without options * in front of ICMP message. * If the original mbuf was meant to bypass the firewall, the error * reply should bypass as well. */ m->m_flags |= n->m_flags & M_SKIP_FIREWALL; m->m_data -= sizeof(struct ip); m->m_len += sizeof(struct ip); m->m_pkthdr.len = m->m_len; m->m_pkthdr.rcvif = n->m_pkthdr.rcvif; nip = mtod(m, struct ip *); bcopy((caddr_t)oip, (caddr_t)nip, sizeof(struct ip)); nip->ip_len = htons(m->m_len); nip->ip_v = IPVERSION; nip->ip_hl = 5; nip->ip_p = IPPROTO_ICMP; nip->ip_tos = 0; nip->ip_off = 0; icmp_reflect(m); freeit: m_freem(n); } /* * Process a received ICMP message. */ void icmp_input(struct mbuf *m, int off) { struct icmp *icp; struct in_ifaddr *ia; struct ip *ip = mtod(m, struct ip *); struct sockaddr_in icmpsrc, icmpdst, icmpgw; int hlen = off; int icmplen = ntohs(ip->ip_len) - off; int i, code; void (*ctlfunc)(int, struct sockaddr *, void *); int fibnum; /* * Locate icmp structure in mbuf, and check * that not corrupted and of at least minimum length. */ #ifdef ICMPPRINTFS if (icmpprintfs) { char buf[4 * sizeof "123"]; strcpy(buf, inet_ntoa(ip->ip_src)); printf("icmp_input from %s to %s, len %d\n", buf, inet_ntoa(ip->ip_dst), icmplen); } #endif if (icmplen < ICMP_MINLEN) { ICMPSTAT_INC(icps_tooshort); goto freeit; } i = hlen + min(icmplen, ICMP_ADVLENMIN); if (m->m_len < i && (m = m_pullup(m, i)) == NULL) { ICMPSTAT_INC(icps_tooshort); return; } ip = mtod(m, struct ip *); m->m_len -= hlen; m->m_data += hlen; icp = mtod(m, struct icmp *); if (in_cksum(m, icmplen)) { ICMPSTAT_INC(icps_checksum); goto freeit; } m->m_len += hlen; m->m_data -= hlen; if (m->m_pkthdr.rcvif && m->m_pkthdr.rcvif->if_type == IFT_FAITH) { /* * Deliver very specific ICMP type only. */ switch (icp->icmp_type) { case ICMP_UNREACH: case ICMP_TIMXCEED: break; default: goto freeit; } } #ifdef ICMPPRINTFS if (icmpprintfs) printf("icmp_input, type %d code %d\n", icp->icmp_type, icp->icmp_code); #endif /* * Message type specific processing. */ if (icp->icmp_type > ICMP_MAXTYPE) goto raw; /* Initialize */ bzero(&icmpsrc, sizeof(icmpsrc)); icmpsrc.sin_len = sizeof(struct sockaddr_in); icmpsrc.sin_family = AF_INET; bzero(&icmpdst, sizeof(icmpdst)); icmpdst.sin_len = sizeof(struct sockaddr_in); icmpdst.sin_family = AF_INET; bzero(&icmpgw, sizeof(icmpgw)); icmpgw.sin_len = sizeof(struct sockaddr_in); icmpgw.sin_family = AF_INET; ICMPSTAT_INC(icps_inhist[icp->icmp_type]); code = icp->icmp_code; switch (icp->icmp_type) { case ICMP_UNREACH: switch (code) { case ICMP_UNREACH_NET: case ICMP_UNREACH_HOST: case ICMP_UNREACH_SRCFAIL: case ICMP_UNREACH_NET_UNKNOWN: case ICMP_UNREACH_HOST_UNKNOWN: case ICMP_UNREACH_ISOLATED: case ICMP_UNREACH_TOSNET: case ICMP_UNREACH_TOSHOST: case ICMP_UNREACH_HOST_PRECEDENCE: case ICMP_UNREACH_PRECEDENCE_CUTOFF: code = PRC_UNREACH_NET; break; case ICMP_UNREACH_NEEDFRAG: code = PRC_MSGSIZE; break; /* * RFC 1122, Sections 3.2.2.1 and 4.2.3.9. * Treat subcodes 2,3 as immediate RST */ case ICMP_UNREACH_PROTOCOL: case ICMP_UNREACH_PORT: code = PRC_UNREACH_PORT; break; case ICMP_UNREACH_NET_PROHIB: case ICMP_UNREACH_HOST_PROHIB: case ICMP_UNREACH_FILTER_PROHIB: code = PRC_UNREACH_ADMIN_PROHIB; break; default: goto badcode; } goto deliver; case ICMP_TIMXCEED: if (code > 1) goto badcode; code += PRC_TIMXCEED_INTRANS; goto deliver; case ICMP_PARAMPROB: if (code > 1) goto badcode; code = PRC_PARAMPROB; goto deliver; case ICMP_SOURCEQUENCH: if (code) goto badcode; code = PRC_QUENCH; deliver: /* * Problem with datagram; advise higher level routines. */ if (icmplen < ICMP_ADVLENMIN || icmplen < ICMP_ADVLEN(icp) || icp->icmp_ip.ip_hl < (sizeof(struct ip) >> 2)) { ICMPSTAT_INC(icps_badlen); goto freeit; } /* Discard ICMP's in response to multicast packets */ if (IN_MULTICAST(ntohl(icp->icmp_ip.ip_dst.s_addr))) goto badcode; #ifdef ICMPPRINTFS if (icmpprintfs) printf("deliver to protocol %d\n", icp->icmp_ip.ip_p); #endif icmpsrc.sin_addr = icp->icmp_ip.ip_dst; /* * XXX if the packet contains [IPv4 AH TCP], we can't make a * notification to TCP layer. */ ctlfunc = inetsw[ip_protox[icp->icmp_ip.ip_p]].pr_ctlinput; if (ctlfunc) (*ctlfunc)(code, (struct sockaddr *)&icmpsrc, (void *)&icp->icmp_ip); break; badcode: ICMPSTAT_INC(icps_badcode); break; case ICMP_ECHO: if (!V_icmpbmcastecho && (m->m_flags & (M_MCAST | M_BCAST)) != 0) { ICMPSTAT_INC(icps_bmcastecho); break; } icp->icmp_type = ICMP_ECHOREPLY; if (badport_bandlim(BANDLIM_ICMP_ECHO) < 0) goto freeit; else goto reflect; case ICMP_TSTAMP: + if (V_icmptstamprepl == 0) + break; if (!V_icmpbmcastecho && (m->m_flags & (M_MCAST | M_BCAST)) != 0) { ICMPSTAT_INC(icps_bmcasttstamp); break; } if (icmplen < ICMP_TSLEN) { ICMPSTAT_INC(icps_badlen); break; } icp->icmp_type = ICMP_TSTAMPREPLY; icp->icmp_rtime = iptime(); icp->icmp_ttime = icp->icmp_rtime; /* bogus, do later! */ if (badport_bandlim(BANDLIM_ICMP_TSTAMP) < 0) goto freeit; else goto reflect; case ICMP_MASKREQ: if (V_icmpmaskrepl == 0) break; /* * We are not able to respond with all ones broadcast * unless we receive it over a point-to-point interface. */ if (icmplen < ICMP_MASKLEN) break; switch (ip->ip_dst.s_addr) { case INADDR_BROADCAST: case INADDR_ANY: icmpdst.sin_addr = ip->ip_src; break; default: icmpdst.sin_addr = ip->ip_dst; } ia = (struct in_ifaddr *)ifaof_ifpforaddr( (struct sockaddr *)&icmpdst, m->m_pkthdr.rcvif); if (ia == NULL) break; if (ia->ia_ifp == NULL) { ifa_free(&ia->ia_ifa); break; } icp->icmp_type = ICMP_MASKREPLY; if (V_icmpmaskfake == 0) icp->icmp_mask = ia->ia_sockmask.sin_addr.s_addr; else icp->icmp_mask = V_icmpmaskfake; if (ip->ip_src.s_addr == 0) { if (ia->ia_ifp->if_flags & IFF_BROADCAST) ip->ip_src = satosin(&ia->ia_broadaddr)->sin_addr; else if (ia->ia_ifp->if_flags & IFF_POINTOPOINT) ip->ip_src = satosin(&ia->ia_dstaddr)->sin_addr; } ifa_free(&ia->ia_ifa); reflect: ICMPSTAT_INC(icps_reflect); ICMPSTAT_INC(icps_outhist[icp->icmp_type]); icmp_reflect(m); return; case ICMP_REDIRECT: if (V_log_redirect) { u_long src, dst, gw; src = ntohl(ip->ip_src.s_addr); dst = ntohl(icp->icmp_ip.ip_dst.s_addr); gw = ntohl(icp->icmp_gwaddr.s_addr); printf("icmp redirect from %d.%d.%d.%d: " "%d.%d.%d.%d => %d.%d.%d.%d\n", (int)(src >> 24), (int)((src >> 16) & 0xff), (int)((src >> 8) & 0xff), (int)(src & 0xff), (int)(dst >> 24), (int)((dst >> 16) & 0xff), (int)((dst >> 8) & 0xff), (int)(dst & 0xff), (int)(gw >> 24), (int)((gw >> 16) & 0xff), (int)((gw >> 8) & 0xff), (int)(gw & 0xff)); } /* * RFC1812 says we must ignore ICMP redirects if we * are acting as router. */ if (V_drop_redirect || V_ipforwarding) break; if (code > 3) goto badcode; if (icmplen < ICMP_ADVLENMIN || icmplen < ICMP_ADVLEN(icp) || icp->icmp_ip.ip_hl < (sizeof(struct ip) >> 2)) { ICMPSTAT_INC(icps_badlen); break; } /* * Short circuit routing redirects to force * immediate change in the kernel's routing * tables. The message is also handed to anyone * listening on a raw socket (e.g. the routing * daemon for use in updating its tables). */ icmpgw.sin_addr = ip->ip_src; icmpdst.sin_addr = icp->icmp_gwaddr; #ifdef ICMPPRINTFS if (icmpprintfs) { char buf[4 * sizeof "123"]; strcpy(buf, inet_ntoa(icp->icmp_ip.ip_dst)); printf("redirect dst %s to %s\n", buf, inet_ntoa(icp->icmp_gwaddr)); } #endif icmpsrc.sin_addr = icp->icmp_ip.ip_dst; for ( fibnum = 0; fibnum < rt_numfibs; fibnum++) { in_rtredirect((struct sockaddr *)&icmpsrc, (struct sockaddr *)&icmpdst, (struct sockaddr *)0, RTF_GATEWAY | RTF_HOST, (struct sockaddr *)&icmpgw, fibnum); } pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&icmpsrc); #ifdef IPSEC key_sa_routechange((struct sockaddr *)&icmpsrc); #endif break; /* * No kernel processing for the following; * just fall through to send to raw listener. */ case ICMP_ECHOREPLY: case ICMP_ROUTERADVERT: case ICMP_ROUTERSOLICIT: case ICMP_TSTAMPREPLY: case ICMP_IREQREPLY: case ICMP_MASKREPLY: default: break; } raw: rip_input(m, off); return; freeit: m_freem(m); } /* * Reflect the ip packet back to the source */ static void icmp_reflect(struct mbuf *m) { struct ip *ip = mtod(m, struct ip *); struct ifaddr *ifa; struct ifnet *ifp; struct in_ifaddr *ia; struct in_addr t; struct mbuf *opts = 0; int optlen = (ip->ip_hl << 2) - sizeof(struct ip); if (IN_MULTICAST(ntohl(ip->ip_src.s_addr)) || IN_EXPERIMENTAL(ntohl(ip->ip_src.s_addr)) || IN_ZERONET(ntohl(ip->ip_src.s_addr)) ) { m_freem(m); /* Bad return address */ ICMPSTAT_INC(icps_badaddr); goto done; /* Ip_output() will check for broadcast */ } t = ip->ip_dst; ip->ip_dst = ip->ip_src; /* * Source selection for ICMP replies: * * If the incoming packet was addressed directly to one of our * own addresses, use dst as the src for the reply. */ IN_IFADDR_RLOCK(); LIST_FOREACH(ia, INADDR_HASH(t.s_addr), ia_hash) { if (t.s_addr == IA_SIN(ia)->sin_addr.s_addr) { t = IA_SIN(ia)->sin_addr; IN_IFADDR_RUNLOCK(); goto match; } } IN_IFADDR_RUNLOCK(); /* * If the incoming packet was addressed to one of our broadcast * addresses, use the first non-broadcast address which corresponds * to the incoming interface. */ ifp = m->m_pkthdr.rcvif; if (ifp != NULL && ifp->if_flags & IFF_BROADCAST) { IF_ADDR_RLOCK(ifp); TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { if (ifa->ifa_addr->sa_family != AF_INET) continue; ia = ifatoia(ifa); if (satosin(&ia->ia_broadaddr)->sin_addr.s_addr == t.s_addr) { t = IA_SIN(ia)->sin_addr; IF_ADDR_RUNLOCK(ifp); goto match; } } IF_ADDR_RUNLOCK(ifp); } /* * If the packet was transiting through us, use the address of * the interface the packet came through in. If that interface * doesn't have a suitable IP address, the normal selection * criteria apply. */ if (V_icmp_rfi && ifp != NULL) { IF_ADDR_RLOCK(ifp); TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { if (ifa->ifa_addr->sa_family != AF_INET) continue; ia = ifatoia(ifa); t = IA_SIN(ia)->sin_addr; IF_ADDR_RUNLOCK(ifp); goto match; } IF_ADDR_RUNLOCK(ifp); } /* * If the incoming packet was not addressed directly to us, use * designated interface for icmp replies specified by sysctl * net.inet.icmp.reply_src (default not set). Otherwise continue * with normal source selection. */ if (V_reply_src[0] != '\0' && (ifp = ifunit(V_reply_src))) { IF_ADDR_RLOCK(ifp); TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { if (ifa->ifa_addr->sa_family != AF_INET) continue; ia = ifatoia(ifa); t = IA_SIN(ia)->sin_addr; IF_ADDR_RUNLOCK(ifp); goto match; } IF_ADDR_RUNLOCK(ifp); } /* * If the packet was transiting through us, use the address of * the interface that is the closest to the packet source. * When we don't have a route back to the packet source, stop here * and drop the packet. */ ia = ip_rtaddr(ip->ip_dst, M_GETFIB(m)); if (ia == NULL) { m_freem(m); ICMPSTAT_INC(icps_noroute); goto done; } t = IA_SIN(ia)->sin_addr; ifa_free(&ia->ia_ifa); match: #ifdef MAC mac_netinet_icmp_replyinplace(m); #endif ip->ip_src = t; ip->ip_ttl = V_ip_defttl; if (optlen > 0) { register u_char *cp; int opt, cnt; u_int len; /* * Retrieve any source routing from the incoming packet; * add on any record-route or timestamp options. */ cp = (u_char *) (ip + 1); if ((opts = ip_srcroute(m)) == 0 && (opts = m_gethdr(M_NOWAIT, MT_DATA))) { opts->m_len = sizeof(struct in_addr); mtod(opts, struct in_addr *)->s_addr = 0; } if (opts) { #ifdef ICMPPRINTFS if (icmpprintfs) printf("icmp_reflect optlen %d rt %d => ", optlen, opts->m_len); #endif for (cnt = optlen; cnt > 0; cnt -= len, cp += len) { opt = cp[IPOPT_OPTVAL]; if (opt == IPOPT_EOL) break; if (opt == IPOPT_NOP) len = 1; else { if (cnt < IPOPT_OLEN + sizeof(*cp)) break; len = cp[IPOPT_OLEN]; if (len < IPOPT_OLEN + sizeof(*cp) || len > cnt) break; } /* * Should check for overflow, but it "can't happen" */ if (opt == IPOPT_RR || opt == IPOPT_TS || opt == IPOPT_SECURITY) { bcopy((caddr_t)cp, mtod(opts, caddr_t) + opts->m_len, len); opts->m_len += len; } } /* Terminate & pad, if necessary */ cnt = opts->m_len % 4; if (cnt) { for (; cnt < 4; cnt++) { *(mtod(opts, caddr_t) + opts->m_len) = IPOPT_EOL; opts->m_len++; } } #ifdef ICMPPRINTFS if (icmpprintfs) printf("%d\n", opts->m_len); #endif } ip_stripoptions(m); } m_tag_delete_nonpersistent(m); m->m_flags &= ~(M_BCAST|M_MCAST); icmp_send(m, opts); done: if (opts) (void)m_free(opts); } /* * Send an icmp packet back to the ip level, * after supplying a checksum. */ static void icmp_send(struct mbuf *m, struct mbuf *opts) { register struct ip *ip = mtod(m, struct ip *); register int hlen; register struct icmp *icp; hlen = ip->ip_hl << 2; m->m_data += hlen; m->m_len -= hlen; icp = mtod(m, struct icmp *); icp->icmp_cksum = 0; icp->icmp_cksum = in_cksum(m, ntohs(ip->ip_len) - hlen); m->m_data -= hlen; m->m_len += hlen; m->m_pkthdr.rcvif = (struct ifnet *)0; #ifdef ICMPPRINTFS if (icmpprintfs) { char buf[4 * sizeof "123"]; strcpy(buf, inet_ntoa(ip->ip_dst)); printf("icmp_send dst %s src %s\n", buf, inet_ntoa(ip->ip_src)); } #endif (void) ip_output(m, opts, NULL, 0, NULL, NULL); } /* * Return milliseconds since 00:00 GMT in network format. */ uint32_t iptime(void) { struct timeval atv; u_long t; getmicrotime(&atv); t = (atv.tv_sec % (24*60*60)) * 1000 + atv.tv_usec / 1000; return (htonl(t)); } /* * Return the next larger or smaller MTU plateau (table from RFC 1191) * given current value MTU. If DIR is less than zero, a larger plateau * is returned; otherwise, a smaller value is returned. */ int ip_next_mtu(int mtu, int dir) { static int mtutab[] = { 65535, 32000, 17914, 8166, 4352, 2002, 1492, 1280, 1006, 508, 296, 68, 0 }; int i, size; size = (sizeof mtutab) / (sizeof mtutab[0]); if (dir >= 0) { for (i = 0; i < size; i++) if (mtu > mtutab[i]) return mtutab[i]; } else { for (i = size - 1; i >= 0; i--) if (mtu < mtutab[i]) return mtutab[i]; if (mtu == mtutab[0]) return mtutab[0]; } return 0; } #endif /* INET */ /* * badport_bandlim() - check for ICMP bandwidth limit * * Return 0 if it is ok to send an ICMP error response, -1 if we have * hit our bandwidth limit and it is not ok. * * If icmplim is <= 0, the feature is disabled and 0 is returned. * * For now we separate the TCP and UDP subsystems w/ different 'which' * values. We may eventually remove this separation (and simplify the * code further). * * Note that the printing of the error message is delayed so we can * properly print the icmp error rate that the system was trying to do * (i.e. 22000/100 pps, etc...). This can cause long delays in printing * the 'final' error, but it doesn't make sense to solve the printing * delay with more complex code. */ int badport_bandlim(int which) { #define N(a) (sizeof (a) / sizeof (a[0])) static struct rate { const char *type; struct timeval lasttime; int curpps; } rates[BANDLIM_MAX+1] = { { "icmp unreach response" }, { "icmp ping response" }, { "icmp tstamp response" }, { "closed port RST response" }, { "open port RST response" }, { "icmp6 unreach response" }, { "sctp ootb response" } }; /* * Return ok status if feature disabled or argument out of range. */ if (V_icmplim > 0 && (u_int) which < N(rates)) { struct rate *r = &rates[which]; int opps = r->curpps; if (!ppsratecheck(&r->lasttime, &r->curpps, V_icmplim)) return -1; /* discard packet */ /* * If we've dropped below the threshold after having * rate-limited traffic print the message. This preserves * the previous behaviour at the expense of added complexity. */ if (V_icmplim_output && opps > V_icmplim) log(LOG_NOTICE, "Limiting %s from %d to %d packets/sec\n", r->type, opps, V_icmplim); } return 0; /* okay to send packet */ #undef N } Index: stable/10 =================================================================== --- stable/10 (revision 281608) +++ stable/10 (revision 281609) Property changes on: stable/10 ___________________________________________________________________ Modified: svn:mergeinfo ## -0,0 +0,1 ## Merged /head:r272378