]> git.saurik.com Git - apple/xnu.git/blobdiff - bsd/netinet/ip_icmp.c
xnu-7195.101.1.tar.gz
[apple/xnu.git] / bsd / netinet / ip_icmp.c
index cb0e43f7a30455aa5855624d99cd03103184da30..0fb3d6f75d6daf58a66f945d4ee3abe6111d9384 100644 (file)
@@ -1,8 +1,8 @@
 /*
- * Copyright (c) 2000-2015 Apple Inc. All rights reserved.
+ * Copyright (c) 2000-2020 Apple Inc. All rights reserved.
  *
  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
- * 
+ *
  * This file contains Original Code and/or Modifications of Original Code
  * as defined in and that are subject to the Apple Public Source License
  * Version 2.0 (the 'License'). You may not use this file except in
  * unlawful or unlicensed copies of an Apple operating system, or to
  * circumvent, violate, or enable the circumvention or violation of, any
  * terms of an Apple operating system software license agreement.
- * 
+ *
  * Please obtain a copy of the License at
  * http://www.opensource.apple.com/apsl/ and read it before using this file.
- * 
+ *
  * The Original Code and all software distributed under the License are
  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
@@ -22,7 +22,7 @@
  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  * Please see the License for the specific language governing rights and
  * limitations under the License.
- * 
+ *
  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  */
 /*
@@ -80,6 +80,7 @@
 
 #include <net/if.h>
 #include <net/route.h>
+#include <net/content_filter.h>
 
 #define _IP_VHL
 #include <netinet/in.h>
 #include <net/necp.h>
 #endif /* NECP */
 
- /* XXX This one should go in sys/mbuf.h. It is used to avoid that
- * a firewall-generated packet loops forever through the firewall.
- */
-#ifndef M_SKIP_FIREWALL
-#define M_SKIP_FIREWALL         0x4000
-#endif 
-
-#if CONFIG_MACF_NET
-#include <security/mac_framework.h>
-#endif /* MAC_NET */
-
 
 /*
  * ICMP routines: error generation, receive packet processing, and
  * host table maintenance routines.
  */
 
-struct icmpstat icmpstat;
+struct  icmpstat icmpstat;
 SYSCTL_STRUCT(_net_inet_icmp, ICMPCTL_STATS, stats,
     CTLFLAG_RD | CTLFLAG_LOCKED,
     &icmpstat, icmpstat, "");
 
-static int     icmpmaskrepl = 0;
+static int      icmpmaskrepl = 0;
 SYSCTL_INT(_net_inet_icmp, ICMPCTL_MASKREPL, maskrepl,
     CTLFLAG_RW | CTLFLAG_LOCKED,
     &icmpmaskrepl, 0, "");
 
-static int     icmptimestamp = 0;
+static int      icmptimestamp = 0;
 SYSCTL_INT(_net_inet_icmp, ICMPCTL_TIMESTAMP, timestamp,
     CTLFLAG_RW | CTLFLAG_LOCKED,
     &icmptimestamp, 0, "");
 
-static int     drop_redirect = 1;
+static int      drop_redirect = 1;
 SYSCTL_INT(_net_inet_icmp, OID_AUTO, drop_redirect,
     CTLFLAG_RW | CTLFLAG_LOCKED,
     &drop_redirect, 0, "");
 
-static int     log_redirect = 0;
+static int      log_redirect = 0;
 SYSCTL_INT(_net_inet_icmp, OID_AUTO, log_redirect,
     CTLFLAG_RW | CTLFLAG_LOCKED,
     &log_redirect, 0, "");
 
 const static int icmp_datalen = 8;
 
-#if ICMP_BANDLIM 
-
+#if ICMP_BANDLIM
 /* Default values in case CONFIG_ICMP_BANDLIM is not defined in the MASTER file */
 #ifndef CONFIG_ICMP_BANDLIM
+#if XNU_TARGET_OS_OSX
 #define CONFIG_ICMP_BANDLIM 250
+#else /* !XNU_TARGET_OS_OSX */
+#define CONFIG_ICMP_BANDLIM 50
+#endif /* !XNU_TARGET_OS_OSX */
 #endif /* CONFIG_ICMP_BANDLIM */
 
-/*    
+/*
  * ICMP error-response bandwidth limiting sysctl.  If not enabled, sysctl
  *      variable content is -1 and read-only.
- */     
-    
+ */
+
 static int      icmplim = CONFIG_ICMP_BANDLIM;
 SYSCTL_INT(_net_inet_icmp, ICMPCTL_ICMPLIM, icmplim, CTLFLAG_RW | CTLFLAG_LOCKED,
-       &icmplim, 0, "");
-
+    &icmplim, 0, "");
 #else /* ICMP_BANDLIM */
-
 static int      icmplim = -1;
 SYSCTL_INT(_net_inet_icmp, ICMPCTL_ICMPLIM, icmplim, CTLFLAG_RD | CTLFLAG_LOCKED,
-       &icmplim, 0, "");
-       
+    &icmplim, 0, "");
 #endif /* ICMP_BANDLIM */
 
+static int      icmplim_random_incr = CONFIG_ICMP_BANDLIM;
+SYSCTL_INT(_net_inet_icmp, ICMPCTL_ICMPLIM_INCR, icmplim_random_incr, CTLFLAG_RW | CTLFLAG_LOCKED,
+    &icmplim_random_incr, 0, "");
+
 /*
  * ICMP broadcast echo sysctl
  */
 
-static int     icmpbmcastecho = 1;
+static int      icmpbmcastecho = 1;
 SYSCTL_INT(_net_inet_icmp, OID_AUTO, bmcastecho, CTLFLAG_RW | CTLFLAG_LOCKED,
-       &icmpbmcastecho, 0, "");
-
+    &icmpbmcastecho, 0, "");
 
-#if ICMPPRINTFS
-int    icmpprintfs = 0;
+#if (DEBUG | DEVELOPMENT)
+static int      icmpprintfs = 0;
+SYSCTL_INT(_net_inet_icmp, OID_AUTO, verbose, CTLFLAG_RW | CTLFLAG_LOCKED,
+    &icmpprintfs, 0, "");
 #endif
 
-static void    icmp_reflect(struct mbuf *);
-static void    icmp_send(struct mbuf *, struct mbuf *);
+static void     icmp_reflect(struct mbuf *);
+static void     icmp_send(struct mbuf *, struct mbuf *);
 
 /*
  * Generate an error packet of type error
@@ -202,135 +197,197 @@ icmp_error(
        u_int32_t dest,
        u_int32_t nextmtu)
 {
-       struct ip *oip, *nip;
-       struct icmp *icp;
-       struct mbuf *m;
-       u_int32_t oiphlen, icmplen, icmpelen, nlen;
+       struct ip *oip = NULL;
+       struct ip *nip = NULL;
+       struct icmp *icp = NULL;
+       struct mbuf *m = NULL;
+       u_int32_t oiphlen = 0;
+       u_int32_t icmplen = 0;
+       u_int32_t icmpelen = 0;
+       u_int32_t nlen = 0;
+
+       VERIFY((u_int)type <= ICMP_MAXTYPE);
+       VERIFY(code <= UINT8_MAX);
 
        /* Expect 32-bit aligned data pointer on strict-align platforms */
        MBUF_STRICT_DATA_ALIGNMENT_CHECK_32(n);
 
+       if (type != ICMP_REDIRECT) {
+               icmpstat.icps_error++;
+       }
+       /*
+        * Don't send error:
+        *   if not the first fragment of message
+        *   if original packet was a multicast or broadcast packet
+        *   if the old packet protocol was ICMP
+        *   error message, only known informational types.
+        */
+       if (n->m_flags & (M_BCAST | M_MCAST)) {
+               goto freeit;
+       }
+
+       /*
+        * Drop if IP header plus ICMP_MINLEN bytes are not contiguous
+        * in first mbuf.
+        */
+       if (n->m_len < sizeof(struct ip) + ICMP_MINLEN) {
+               goto freeit;
+       }
+
        oip = mtod(n, struct ip *);
        oiphlen = IP_VHL_HL(oip->ip_vhl) << 2;
+       if (n->m_len < oiphlen + ICMP_MINLEN) {
+               goto freeit;
+       }
 
-#if ICMPPRINTFS
-       if (icmpprintfs)
+#if (DEBUG | DEVELOPMENT)
+       if (icmpprintfs > 1) {
                printf("icmp_error(0x%llx, %x, %d)\n",
                    (uint64_t)VM_KERNEL_ADDRPERM(oip), type, code);
+       }
 #endif
-       if (type != ICMP_REDIRECT)
-               icmpstat.icps_error++;
-       /*
-        * Don't send error if not the first fragment of message.
-        * Don't error if the old packet protocol was ICMP
-        * error message, only known informational types.
-        */
-       if (oip->ip_off & ~(IP_MF|IP_DF))
+
+       if (oip->ip_off & ~(IP_MF | IP_DF)) {
                goto freeit;
+       }
 
        if (oip->ip_p == IPPROTO_ICMP && type != ICMP_REDIRECT &&
-         n->m_len >= oiphlen + ICMP_MINLEN &&
-         !ICMP_INFOTYPE(((struct icmp *)(void *)((caddr_t)oip + oiphlen))->
-         icmp_type)) {
+           n->m_len >= oiphlen + ICMP_MINLEN &&
+           !ICMP_INFOTYPE(((struct icmp *)(void *)((caddr_t)oip + oiphlen))->
+           icmp_type)) {
                icmpstat.icps_oldicmp++;
                goto freeit;
        }
-       /*
-        * Don't send error in response to a multicast or
-        * broadcast packet
-        */
-       if (n->m_flags & (M_BCAST|M_MCAST))
-               goto freeit;
 
        /*
         * Calculate the 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);
        if (oip->ip_p == IPPROTO_TCP) {
-               struct tcphdr *th;
-               u_int16_t tcphlen;
+               struct tcphdr *th = NULL;
+               u_int16_t tcphlen = 0;
 
+               /*
+                * If the packet got truncated and TCP header
+                * is not contained in the packet, send out
+                * standard reply with only IP header as payload
+                */
                if (oiphlen + sizeof(struct tcphdr) > n->m_len &&
-                   n->m_next == NULL)
+                   n->m_next == NULL) {
                        goto stdreply;
+               }
+
+               /*
+                * Otherwise, pull up to get IP and TCP headers
+                * together
+                */
                if (n->m_len < (oiphlen + sizeof(struct tcphdr)) &&
-                   (n = m_pullup(n, (oiphlen + sizeof(struct tcphdr)))) == NULL)
+                   (n = m_pullup(n, (oiphlen + sizeof(struct tcphdr)))) == NULL) {
                        goto freeit;
+               }
 
+               /*
+                * Reinit pointers derived from mbuf data pointer
+                * as things might have moved around with m_pullup
+                */
+               oip = mtod(n, struct ip *);
                th = (struct tcphdr *)(void *)((caddr_t)oip + oiphlen);
+
                if (th != ((struct tcphdr *)P2ROUNDDOWN(th,
-                   sizeof(u_int32_t))))
+                   sizeof(u_int32_t))) ||
+                   ((th->th_off << 2) > UINT16_MAX)) {
                        goto freeit;
-               tcphlen = th->th_off << 2;
-               if (tcphlen < sizeof(struct tcphdr))
+               }
+               tcphlen = (uint16_t)(th->th_off << 2);
+
+               /* Sanity checks */
+               if (tcphlen < sizeof(struct tcphdr)) {
                        goto freeit;
-               if (oip->ip_len < (oiphlen + tcphlen))
+               }
+               if (oip->ip_len < (oiphlen + tcphlen)) {
                        goto freeit;
-               if ((oiphlen + tcphlen) > n->m_len && n->m_next == NULL)
+               }
+               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)
+                   (n = m_pullup(n, (oiphlen + tcphlen))) == NULL) {
                        goto freeit;
+               }
+
+               /*
+                * Reinit pointers derived from mbuf data pointer
+                * as things might have moved around with m_pullup
+                */
+               oip = mtod(n, struct ip *);
+               th = (struct tcphdr *)(void *)((caddr_t)oip + oiphlen);
 
                icmpelen = max(tcphlen, min(icmp_datalen,
                    (oip->ip_len - oiphlen)));
-       } else
-stdreply:      icmpelen = max(ICMP_MINLEN, min(icmp_datalen,
-                   (ntohs(oip->ip_len) - oiphlen)));
+       } else {
+stdreply:       icmpelen = max(ICMP_MINLEN, min(icmp_datalen,
+                   (oip->ip_len - oiphlen)));
+       }
 
-       icmplen = min(oiphlen + icmpelen, min(nlen, oip->ip_len));
-       if (icmplen < sizeof(struct ip))
+       icmplen = min(oiphlen + icmpelen, nlen);
+       if (icmplen < sizeof(struct ip)) {
                goto freeit;
+       }
+
        /*
         * First, formulate icmp message
+        * Allocate enough space for the IP header, ICMP header
+        * and the payload (part of the original message to be sent back).
         */
-       if (MHLEN > (sizeof(struct ip) + ICMP_MINLEN + icmplen))
-               m = m_gethdr(M_DONTWAIT, MT_HEADER);    /* MAC-OK */
-       else
+       if (MHLEN > (sizeof(struct ip) + ICMP_MINLEN + icmplen)) {
+               m = m_gethdr(M_DONTWAIT, MT_HEADER);    /* MAC-OK */
+       } else {
                m = m_getcl(M_DONTWAIT, MT_DATA, M_PKTHDR);
+       }
 
-       if (m == NULL)
+       if (m == NULL) {
                goto freeit;
-
-       if (n->m_flags & M_SKIP_FIREWALL) {
-               /*
-                * set M_SKIP_FIREWALL to skip firewall check, since
-                * we're called from firewall
-                */
-               m->m_flags |= M_SKIP_FIREWALL;
        }
 
-#if CONFIG_MACF_NET
-       mac_mbuf_label_associate_netlayer(n, m);
-#endif
-       m->m_len = icmplen + ICMP_MINLEN; /* for ICMP header and data */
-       MH_ALIGN(m, m->m_len);
+       /*
+        * Further refine the payload length to the space
+        * remaining in mbuf after including the IP header and ICMP
+        * header.
+        */
+       icmplen = min(icmplen, (u_int)M_TRAILINGSPACE(m) -
+           (u_int)(sizeof(struct ip) - ICMP_MINLEN));
+       m_align(m, ICMP_MINLEN + icmplen);
+       m->m_len = ICMP_MINLEN + icmplen; /* for ICMP header and data */
+
        icp = mtod(m, struct icmp *);
-       if ((u_int)type > ICMP_MAXTYPE) {
-               m_freem(m);
-               goto freeit;
-       }
        icmpstat.icps_outhist[type]++;
-       icp->icmp_type = type;
-       if (type == ICMP_REDIRECT)
+       icp->icmp_type = (u_char)type;
+       if (type == ICMP_REDIRECT) {
                icp->icmp_gwaddr.s_addr = dest;
-       else {
+       else {
                icp->icmp_void = 0;
                /*
                 * The following assignments assume an overlay with the
                 * zeroed icmp_void field.
                 */
                if (type == ICMP_PARAMPROB) {
-                       icp->icmp_pptr = code;
+                       icp->icmp_pptr = (u_char)code;
                        code = 0;
                } else if (type == ICMP_UNREACH &&
                    code == ICMP_UNREACH_NEEDFRAG && nextmtu != 0) {
-                       icp->icmp_nextmtu = htons(nextmtu);
+                       icp->icmp_nextmtu = htons((uint16_t)nextmtu);
                }
        }
 
-       icp->icmp_code = code;
+       icp->icmp_code = (u_char)code;
+
+       /*
+        * Copy icmplen worth of content from original
+        * mbuf (n) to the new packet after ICMP header.
+        */
        m_copydata(n, 0, icmplen, (caddr_t)&icp->icmp_ip);
        nip = &icp->icmp_ip;
 
@@ -342,26 +399,21 @@ stdreply: icmpelen = max(ICMP_MINLEN, min(icmp_datalen,
        HTONS(nip->ip_off);
 #endif
        /*
-        * Now, copy old ip header (without options)
-        * in front of icmp message.
+        * Set up ICMP message mbuf and copy old IP header (without options
+        * in front of ICMP message.
         */
-       if (m->m_data - sizeof(struct ip) < m->m_pktdat) {
-               m_freem(m);
-               goto freeit;
-       }
        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 = m->m_len;
+       nip->ip_len = (uint16_t)m->m_len;
        nip->ip_vhl = IP_VHL_BORING;
        nip->ip_p = IPPROTO_ICMP;
        nip->ip_tos = 0;
        nip->ip_off = 0;
        icmp_reflect(m);
-
 freeit:
        m_freem(n);
 }
@@ -378,8 +430,9 @@ icmp_input(struct mbuf *m, int hlen)
        int icmplen;
        int i;
        struct in_ifaddr *ia;
-       void (*ctlfunc)(int, struct sockaddr *, void *);
+       void (*ctlfunc)(int, struct sockaddr *, void *, struct ifnet *);
        int code;
+       boolean_t should_log_redirect = false;
 
        /* Expect 32-bit aligned data pointer on strict-align platforms */
        MBUF_STRICT_DATA_ALIGNMENT_CHECK_32(m);
@@ -390,15 +443,15 @@ icmp_input(struct mbuf *m, int hlen)
         * Locate icmp structure in mbuf, and check
         * that not corrupted and of at least minimum length.
         */
-#if ICMPPRINTFS
-       if (icmpprintfs) {
-               char buf[MAX_IPv4_STR_LEN];
-               char ipv4str[MAX_IPv4_STR_LEN];
-
-               printf("icmp_input from %s to %s, len %d\n",
-                      inet_ntop(AF_INET, &ip->ip_src, buf, sizeof(buf)),
-                      inet_ntop(AF_INET, &ip->ip_dst, ipv4str, sizeof(ipv4str)),
-                      icmplen);
+#if (DEBUG | DEVELOPMENT)
+       if (icmpprintfs > 2) {
+               char src_str[MAX_IPv4_STR_LEN];
+               char dst_str[MAX_IPv4_STR_LEN];
+
+               inet_ntop(AF_INET, &ip->ip_src, src_str, sizeof(src_str));
+               inet_ntop(AF_INET, &ip->ip_dst, dst_str, sizeof(dst_str));
+               printf("%s: from %s to %s, len %d\n",
+                   __func__, src_str, dst_str, icmplen);
        }
 #endif
        if (icmplen < ICMP_MINLEN) {
@@ -406,7 +459,7 @@ icmp_input(struct mbuf *m, int hlen)
                goto freeit;
        }
        i = hlen + min(icmplen, ICMP_ADVLENMIN);
-       if (m->m_len < i && (m = m_pullup(m, i)) == 0)  {
+       if (m->m_len < i && (m = m_pullup(m, i)) == 0) {
                icmpstat.icps_tooshort++;
                return;
        }
@@ -421,143 +474,188 @@ icmp_input(struct mbuf *m, int hlen)
        m->m_len += hlen;
        m->m_data -= hlen;
 
-#if ICMPPRINTFS
-       if (icmpprintfs)
+#if (DEBUG | DEVELOPMENT)
+       if (icmpprintfs > 2) {
                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)
+       if (icp->icmp_type > ICMP_MAXTYPE) {
                goto raw;
+       }
 
        /* Initialize */
-       bzero(&icmpsrc, sizeof (icmpsrc));
-       icmpsrc.sin_len = sizeof (struct sockaddr_in);
+       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);
+       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);
+       bzero(&icmpgw, sizeof(icmpgw));
+       icmpgw.sin_len = sizeof(struct sockaddr_in);
        icmpgw.sin_family = AF_INET;
 
        icmpstat.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_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;
+               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;
+               /*
+                * 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;
+               case ICMP_UNREACH_NET_PROHIB:
+               case ICMP_UNREACH_HOST_PROHIB:
+               case ICMP_UNREACH_FILTER_PROHIB:
+                       code = PRC_UNREACH_ADMIN_PROHIB;
+                       break;
 
-                       default:
-                               goto badcode;
+               default:
+                       goto badcode;
                }
                goto deliver;
 
        case ICMP_TIMXCEED:
-               if (code > 1)
+               if (code > 1) {
                        goto badcode;
+               }
                code += PRC_TIMXCEED_INTRANS;
                goto deliver;
 
        case ICMP_PARAMPROB:
-               if (code > 1)
+               if (code > 1) {
                        goto badcode;
+               }
                code = PRC_PARAMPROB;
                goto deliver;
 
        case ICMP_SOURCEQUENCH:
-               if (code)
+               if (code) {
                        goto badcode;
+               }
                code = PRC_QUENCH;
-       deliver:
+deliver:
                /*
                 * Problem with datagram; advise higher level routines.
                 */
-               if (icmplen < ICMP_ADVLENMIN || icmplen < ICMP_ADVLEN(icp) ||
-                   IP_VHL_HL(icp->icmp_ip.ip_vhl) < (sizeof(struct ip) >> 2)) {
+               if (icmplen < ICMP_ADVLENMIN || icmplen < ICMP_ADVLEN(icp)
+                   || IP_VHL_HL(icp->icmp_ip.ip_vhl) <
+                   (sizeof(struct ip) >> 2) ||
+                   (m = m_pullup(m, hlen + ICMP_ADVLEN(icp))) == NULL) {
                        icmpstat.icps_badlen++;
                        goto freeit;
                }
 
+               ip = mtod(m, struct ip *);
+               icp = (struct icmp *)(void *)(mtod(m, uint8_t *) + hlen);
+
 #if BYTE_ORDER != BIG_ENDIAN
                NTOHS(icp->icmp_ip.ip_len);
 #endif
 
                /* Discard ICMP's in response to multicast packets */
-               if (IN_MULTICAST(ntohl(icp->icmp_ip.ip_dst.s_addr)))
+               if (IN_MULTICAST(ntohl(icp->icmp_ip.ip_dst.s_addr))) {
                        goto badcode;
-#if ICMPPRINTFS
-               if (icmpprintfs)
-                       printf("deliver to protocol %d\n", icp->icmp_ip.ip_p);
+               }
+#if (DEBUG | DEVELOPMENT)
+               if (icmpprintfs > 2) {
+                       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
+                * if the packet contains [IPv4 AH TCP], we can't make a
                 * notification to TCP layer.
                 */
                ctlfunc = ip_protox[icp->icmp_ip.ip_p]->pr_ctlinput;
-               if (ctlfunc)
+
+               if (ctlfunc) {
+                       LCK_MTX_ASSERT(inet_domain_mutex, LCK_MTX_ASSERT_OWNED);
+
+                       lck_mtx_unlock(inet_domain_mutex);
+
                        (*ctlfunc)(code, (struct sockaddr *)&icmpsrc,
-                                  (void *)&icp->icmp_ip);
+                           (void *)&icp->icmp_ip, m->m_pkthdr.rcvif);
+
+                       lck_mtx_lock(inet_domain_mutex);
+               }
                break;
 
-       badcode:
+badcode:
                icmpstat.icps_badcode++;
                break;
 
        case ICMP_ECHO:
-               if (!icmpbmcastecho
-                   && (m->m_flags & (M_MCAST | M_BCAST)) != 0) {
+               if ((m->m_flags & (M_MCAST | M_BCAST))) {
+                       if (icmpbmcastecho == 0) {
+                               icmpstat.icps_bmcastecho++;
+                               break;
+                       }
+               }
+
+               /*
+                * rdar://18644769
+                * Do not reply when the destination is link local multicast or broadcast
+                * and the source is not from a directly connected subnet
+                */
+               if ((IN_LOCAL_GROUP(ntohl(ip->ip_dst.s_addr)) ||
+                   in_broadcast(ip->ip_dst, m->m_pkthdr.rcvif)) &&
+                   in_localaddr(ip->ip_src) == 0) {
                        icmpstat.icps_bmcastecho++;
+#if (DEBUG | DEVELOPMENT)
+                       if (icmpprintfs > 0) {
+                               char src_str[MAX_IPv4_STR_LEN];
+                               char dst_str[MAX_IPv4_STR_LEN];
+
+                               inet_ntop(AF_INET, &ip->ip_src, src_str, sizeof(src_str));
+                               inet_ntop(AF_INET, &ip->ip_dst, dst_str, sizeof(dst_str));
+                               printf("%s: non local (B|M)CAST %s to %s, len %d\n",
+                                   __func__, src_str, dst_str, icmplen);
+                       }
+#endif
                        break;
                }
+
                icp->icmp_type = ICMP_ECHOREPLY;
 #if ICMP_BANDLIM
-               if (badport_bandlim(BANDLIM_ICMP_ECHO) < 0)
+               if (badport_bandlim(BANDLIM_ICMP_ECHO)) {
                        goto freeit;
-               else
+               else
 #endif
-                       goto reflect;
+               goto reflect;
 
        case ICMP_TSTAMP:
-
-               if (icmptimestamp == 0)
+               if (icmptimestamp == 0) {
                        break;
+               }
 
                if (!icmpbmcastecho
                    && (m->m_flags & (M_MCAST | M_BCAST)) != 0) {
@@ -570,25 +668,26 @@ icmp_input(struct mbuf *m, int hlen)
                }
                icp->icmp_type = ICMP_TSTAMPREPLY;
                icp->icmp_rtime = iptime();
-               icp->icmp_ttime = icp->icmp_rtime;      /* bogus, do later! */
+               icp->icmp_ttime = icp->icmp_rtime;      /* bogus, do later! */
 #if ICMP_BANDLIM
-               if (badport_bandlim(BANDLIM_ICMP_TSTAMP) < 0)
+               if (badport_bandlim(BANDLIM_ICMP_TSTAMP)) {
                        goto freeit;
-               else
+               else
 #endif
-                       goto reflect;
+               goto reflect;
 
        case ICMP_MASKREQ:
-               if (icmpmaskrepl == 0)
+               if (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)
+               if (icmplen < ICMP_MASKLEN) {
                        break;
+               }
                switch (ip->ip_dst.s_addr) {
-
                case INADDR_BROADCAST:
                case INADDR_ANY:
                        icmpdst.sin_addr = ip->ip_src;
@@ -598,9 +697,10 @@ icmp_input(struct mbuf *m, int hlen)
                        icmpdst.sin_addr = ip->ip_dst;
                }
                ia = (struct in_ifaddr *)ifaof_ifpforaddr(
-                           (struct sockaddr *)&icmpdst, m->m_pkthdr.rcvif);
-               if (ia == 0)
+                       (struct sockaddr *)&icmpdst, m->m_pkthdr.rcvif);
+               if (ia == 0) {
                        break;
+               }
                IFA_LOCK(&ia->ia_ifa);
                if (ia->ia_ifp == 0) {
                        IFA_UNLOCK(&ia->ia_ifa);
@@ -611,45 +711,39 @@ icmp_input(struct mbuf *m, int hlen)
                icp->icmp_type = ICMP_MASKREPLY;
                icp->icmp_mask = ia->ia_sockmask.sin_addr.s_addr;
                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;
+                       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_UNLOCK(&ia->ia_ifa);
                IFA_REMREF(&ia->ia_ifa);
 reflect:
-               ip->ip_len += hlen;     /* since ip_input deducts this */
+               ip->ip_len += hlen;     /* since ip_input deducts this */
                icmpstat.icps_reflect++;
                icmpstat.icps_outhist[icp->icmp_type]++;
                icmp_reflect(m);
                return;
 
        case ICMP_REDIRECT:
-               if (log_redirect) {
-                       u_int32_t 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));
-               }
-               if (drop_redirect)
+               if (drop_redirect) {
                        break;
-               if (code > 3)
+               }
+               if (code > 3) {
                        goto badcode;
+               }
                if (icmplen < ICMP_ADVLENMIN || icmplen < ICMP_ADVLEN(icp) ||
                    IP_VHL_HL(icp->icmp_ip.ip_vhl) < (sizeof(struct ip) >> 2)) {
                        icmpstat.icps_badlen++;
                        break;
                }
+
+#if (DEBUG | DEVELOPMENT)
+               should_log_redirect = log_redirect || (icmpprintfs > 0);
+#else
+               should_log_redirect = log_redirect;
+#endif
                /*
                 * Short circuit routing redirects to force
                 * immediate change in the kernel's routing
@@ -659,20 +753,22 @@ reflect:
                 */
                icmpgw.sin_addr = ip->ip_src;
                icmpdst.sin_addr = icp->icmp_gwaddr;
-#if    ICMPPRINTFS
-               if (icmpprintfs) {
-                       char buf[MAX_IPv4_STR_LEN];
-
-                       printf("redirect dst %s to %s\n",
-                              inet_ntop(AF_INET, &icp->icmp_ip.ip_dst, buf, sizeof(buf)),
-                              inet_ntop(AF_INET, &icp->icmp_gwaddr, ipv4str,
-                                                sizeof(ipv4str)));
+
+               if (should_log_redirect) {
+                       char src_str[MAX_IPv4_STR_LEN];
+                       char dst_str[MAX_IPv4_STR_LEN];
+                       char gw_str[MAX_IPv4_STR_LEN];
+
+                       inet_ntop(AF_INET, &ip->ip_src, src_str, sizeof(src_str));
+                       inet_ntop(AF_INET, &icp->icmp_ip.ip_dst, dst_str, sizeof(dst_str));
+                       inet_ntop(AF_INET, &icp->icmp_gwaddr, gw_str, sizeof(gw_str));
+                       printf("%s: redirect dst %s to %s from %s\n", __func__,
+                           dst_str, gw_str, src_str);
                }
-#endif
                icmpsrc.sin_addr = icp->icmp_ip.ip_dst;
                rtredirect(m->m_pkthdr.rcvif, (struct sockaddr *)&icmpsrc,
-                 (struct sockaddr *)&icmpdst, NULL, RTF_GATEWAY | RTF_HOST,
-                 (struct sockaddr *)&icmpgw, NULL);
+                   (struct sockaddr *)&icmpdst, NULL, RTF_GATEWAY | RTF_HOST,
+                   (struct sockaddr *)&icmpgw, NULL);
                pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&icmpsrc);
 #if IPSEC
                key_sa_routechange((struct sockaddr *)&icmpsrc);
@@ -716,9 +812,9 @@ icmp_reflect(struct mbuf *m)
 
        if (!in_canforward(ip->ip_src) &&
            ((ntohl(ip->ip_src.s_addr) & IN_CLASSA_NET) !=
-            (IN_LOOPBACKNET << IN_CLASSA_NSHIFT))) {
-               m_freem(m);     /* Bad return address */
-               goto done;      /* Ip_output() will check for broadcast */
+           (IN_LOOPBACKNET << IN_CLASSA_NSHIFT))) {
+               m_freem(m);     /* Bad return address */
+               goto done;      /* Ip_output() will check for broadcast */
        }
        t = ip->ip_dst;
        ip->ip_dst = ip->ip_src;
@@ -757,13 +853,14 @@ match:
        lck_rw_done(in_ifaddr_rwlock);
 
        /* Initialize */
-       bzero(&icmpdst, sizeof (icmpdst));
-       icmpdst.sin_len = sizeof (struct sockaddr_in);
+       bzero(&icmpdst, sizeof(icmpdst));
+       icmpdst.sin_len = sizeof(struct sockaddr_in);
        icmpdst.sin_family = AF_INET;
        icmpdst.sin_addr = t;
-       if ((ia == (struct in_ifaddr *)0) && m->m_pkthdr.rcvif)
+       if ((ia == (struct in_ifaddr *)0) && m->m_pkthdr.rcvif) {
                ia = (struct in_ifaddr *)ifaof_ifpforaddr(
                        (struct sockaddr *)&icmpdst, m->m_pkthdr.rcvif);
+       }
        /*
         * The following happens if the packet was not addressed to us,
         * and was received on an interface with no IP address.
@@ -779,14 +876,11 @@ match:
                IFA_ADDREF(&ia->ia_ifa);
                lck_rw_done(in_ifaddr_rwlock);
        }
-#if CONFIG_MACF_NET
-       mac_netinet_icmp_reply(m);
-#endif
        IFA_LOCK_SPIN(&ia->ia_ifa);
        t = IA_SIN(ia)->sin_addr;
        IFA_UNLOCK(&ia->ia_ifa);
        ip->ip_src = t;
-       ip->ip_ttl = ip_defttl;
+       ip->ip_ttl = (u_char)ip_defttl;
        IFA_REMREF(&ia->ia_ifa);
        ia = NULL;
 
@@ -801,52 +895,57 @@ match:
                 */
                cp = (u_char *) (ip + 1);
                if ((opts = ip_srcroute()) == 0 &&
-                   (opts = m_gethdr(M_DONTWAIT, MT_HEADER))) { /* MAC-OK */
+                   (opts = m_gethdr(M_DONTWAIT, MT_HEADER))) { /* MAC-OK */
                        opts->m_len = sizeof(struct in_addr);
                        mtod(opts, struct in_addr *)->s_addr = 0;
                }
                if (opts) {
-#if ICMPPRINTFS
-                   if (icmpprintfs)
-                           printf("icmp_reflect optlen %d rt %d => ",
-                               optlen, opts->m_len);
+#if (DEBUG | DEVELOPMENT)
+                       if (icmpprintfs > 1) {
+                               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++;
-                           }
-                   }
-#if ICMPPRINTFS
-                   if (icmpprintfs)
-                           printf("%d\n", opts->m_len);
+                       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++;
+                               }
+                       }
+#if (DEBUG | DEVELOPMENT)
+                       if (icmpprintfs > 1) {
+                               printf("%d\n", opts->m_len);
+                       }
 #endif
                }
                /*
@@ -856,17 +955,19 @@ match:
                ip->ip_len -= optlen;
                ip->ip_vhl = IP_VHL_BORING;
                m->m_len -= optlen;
-               if (m->m_flags & M_PKTHDR)
+               if (m->m_flags & M_PKTHDR) {
                        m->m_pkthdr.len -= optlen;
+               }
                optlen += sizeof(struct ip);
                bcopy((caddr_t)ip + optlen, (caddr_t)(ip + 1),
-                        (unsigned)(m->m_len - sizeof(struct ip)));
+                   (unsigned)(m->m_len - sizeof(struct ip)));
        }
-       m->m_flags &= ~(M_BCAST|M_MCAST);
+       m->m_flags &= ~(M_BCAST | M_MCAST);
        icmp_send(m, opts);
 done:
-       if (opts)
+       if (opts) {
                (void)m_free(opts);
+       }
 }
 
 /*
@@ -880,8 +981,13 @@ icmp_send(struct mbuf *m, struct mbuf *opts)
        int hlen;
        struct icmp *icp;
        struct route ro;
-       struct ip_out_args ipoa = { IFSCOPE_NONE, { 0 },
-           IPOAF_SELECT_SRCIF | IPOAF_BOUND_SRCADDR, 0 };
+       struct ip_out_args ipoa;
+
+       bzero(&ipoa, sizeof(ipoa));
+       ipoa.ipoa_boundif = IFSCOPE_NONE;
+       ipoa.ipoa_flags = IPOAF_SELECT_SRCIF | IPOAF_BOUND_SRCADDR;
+       ipoa.ipoa_sotc = SO_TC_UNSPEC;
+       ipoa.ipoa_netsvctype = _NET_SERVICE_TYPE_UNSPEC;
 
        if (!(m->m_pkthdr.pkt_flags & PKTF_LOOP) && m->m_pkthdr.rcvif != NULL) {
                ipoa.ipoa_boundif = m->m_pkthdr.rcvif->if_index;
@@ -899,14 +1005,14 @@ icmp_send(struct mbuf *m, struct mbuf *opts)
        m->m_pkthdr.rcvif = NULL;
        m->m_pkthdr.csum_data = 0;
        m->m_pkthdr.csum_flags = 0;
-#if ICMPPRINTFS
-       if (icmpprintfs) {
-               char buf[MAX_IPv4_STR_LEN];
-               char ipv4str[MAX_IPv4_STR_LEN];
-
-               printf("icmp_send dst %s src %s\n",
-                      inet_ntop(AF_INET, &ip->ip_dst, buf, sizeof(buf)),
-                      inet_ntop(AF_INET, &ip->ip_src, ipv4str, sizeof(ipv4str)));
+#if (DEBUG | DEVELOPMENT)
+       if (icmpprintfs > 2) {
+               char src_str[MAX_IPv4_STR_LEN];
+               char dst_str[MAX_IPv4_STR_LEN];
+
+               inet_ntop(AF_INET, &ip->ip_src, src_str, sizeof(src_str));
+               inet_ntop(AF_INET, &ip->ip_dst, dst_str, sizeof(dst_str));
+               printf("%s: dst %s src %s\n", __func__, dst_str, src_str);
        }
 #endif
        bzero(&ro, sizeof ro);
@@ -921,8 +1027,8 @@ iptime(void)
        u_int32_t t;
 
        getmicrotime(&atv);
-       t = (atv.tv_sec % (24*60*60)) * 1000 + atv.tv_usec / 1000;
-       return (htonl(t));
+       t = (atv.tv_sec % (24 * 60 * 60)) * 1000 + atv.tv_usec / 1000;
+       return htonl(t);
 }
 
 #if 1
@@ -941,8 +1047,9 @@ ip_next_mtu(int mtu, int dir)
        int i;
 
        for (i = 0; i < (sizeof mtutab) / (sizeof mtutab[0]); i++) {
-               if (mtu >= mtutab[i])
+               if (mtu >= mtutab[i]) {
                        break;
+               }
        }
 
        if (dir < 0) {
@@ -954,7 +1061,7 @@ ip_next_mtu(int mtu, int dir)
        } else {
                if (mtutab[i] == 0) {
                        return 0;
-               } else if(mtu > mtutab[i]) {
+               } else if (mtu > mtutab[i]) {
                        return mtutab[i];
                } else {
                        return mtutab[i + 1];
@@ -967,11 +1074,8 @@ ip_next_mtu(int mtu, int dir)
 
 /*
  * 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.
+ *     Returns false when it is ok to send ICMP error and true to limit sending
+ *     of ICMP error.
  *
  *     For now we separate the TCP and UDP subsystems w/ different 'which'
  *     values.  We may eventually remove this separation (and simplify the
@@ -980,34 +1084,42 @@ ip_next_mtu(int mtu, int dir)
  *     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 
+ *     the 'final' error, but it doesn't make sense to solve the printing
  *     delay with more complex code.
  */
 
-int
+boolean_t
 badport_bandlim(int which)
 {
        static uint64_t lticks[BANDLIM_MAX + 1];
        static int lpackets[BANDLIM_MAX + 1];
-       uint64_t time = net_uptime();
-       int secs;
-
+       uint64_t time;
+       uint64_t secs;
+       static boolean_t is_initialized = FALSE;
+       static int icmplim_random;
        const char *bandlimittype[] = {
                "Limiting icmp unreach response",
                "Limiting icmp ping response",
                "Limiting icmp tstamp response",
                "Limiting closed port RST response",
                "Limiting open port RST response"
-               };
+       };
 
-       /*
-        * Return ok status if feature disabled or argument out of
-        * ranage.
-        */
+       /* Return ok status if feature disabled or argument out of range. */
 
-       if (icmplim <= 0 || which > BANDLIM_MAX || which < 0)
-               return(0);
+       if (icmplim <= 0 || which > BANDLIM_MAX || which < 0) {
+               return false;
+       }
 
+       if (is_initialized == FALSE) {
+               if (icmplim_random_incr > 0 &&
+                   icmplim <= INT32_MAX - (icmplim_random_incr + 1)) {
+                       icmplim_random = icmplim + (random() % icmplim_random_incr) + 1;
+               }
+               is_initialized = TRUE;
+       }
+
+       time = net_uptime();
        secs = time - lticks[which];
 
        /*
@@ -1015,12 +1127,12 @@ badport_bandlim(int which)
         */
 
        if (secs > 1) {
-               if (lpackets[which] > icmplim) {
+               if (lpackets[which] > icmplim_random) {
                        printf("%s from %d to %d packets per second\n",
-                               bandlimittype[which],
-                               lpackets[which],
-                               icmplim
-                       );
+                           bandlimittype[which],
+                           lpackets[which],
+                           icmplim_random
+                           );
                }
                lticks[which] = time;
                lpackets[which] = 0;
@@ -1029,11 +1141,18 @@ badport_bandlim(int which)
        /*
         * bump packet count
         */
-
-       if (++lpackets[which] > icmplim) {
-               return(-1);
+       if (++lpackets[which] > icmplim_random) {
+               /*
+                * After hitting the randomized limit, we further randomize the
+                * behavior of how we apply rate limitation.
+                * We rate limit based on probability that increases with the
+                * increase in lpackets[which] count.
+                */
+               if ((random() % (lpackets[which] - icmplim_random)) != 0) {
+                       return true;
+               }
        }
-       return(0);
+       return false;
 }
 
 #endif
@@ -1066,43 +1185,46 @@ __private_extern__ int icmp_dgram_attach(struct socket *so, int proto, struct pr
 __private_extern__ int icmp_dgram_ctloutput(struct socket *so, struct sockopt *sopt);
 
 __private_extern__ struct pr_usrreqs icmp_dgram_usrreqs = {
-       .pru_abort =            rip_abort,
-       .pru_attach =           icmp_dgram_attach,
-       .pru_bind =             rip_bind,
-       .pru_connect =          rip_connect,
-       .pru_control =          in_control,
-       .pru_detach =           rip_detach,
-       .pru_disconnect =       rip_disconnect,
-       .pru_peeraddr =         in_getpeeraddr,
-       .pru_send =             icmp_dgram_send,
-       .pru_shutdown =         rip_shutdown,
-       .pru_sockaddr =         in_getsockaddr,
-       .pru_sosend =           sosend,
-       .pru_soreceive =        soreceive,
+       .pru_abort =            rip_abort,
+       .pru_attach =           icmp_dgram_attach,
+       .pru_bind =             rip_bind,
+       .pru_connect =          rip_connect,
+       .pru_control =          in_control,
+       .pru_detach =           rip_detach,
+       .pru_disconnect =       rip_disconnect,
+       .pru_peeraddr =         in_getpeeraddr,
+       .pru_send =             icmp_dgram_send,
+       .pru_shutdown =         rip_shutdown,
+       .pru_sockaddr =         in_getsockaddr,
+       .pru_sosend =           sosend,
+       .pru_soreceive =        soreceive,
 };
 
 /* Like rip_attach but without root privilege enforcement */
 __private_extern__ int
 icmp_dgram_attach(struct socket *so, __unused int proto, struct proc *p)
 {
-        struct inpcb *inp;
-        int error;
-
-        inp = sotoinpcb(so);
-        if (inp)
-                panic("icmp_dgram_attach");
-
-        error = soreserve(so, rip_sendspace, rip_recvspace);
-        if (error)
-                return error;
-        error = in_pcballoc(so, &ripcbinfo, p);
-        if (error)
-                return error;
-        inp = (struct inpcb *)so->so_pcb;       
-        inp->inp_vflag |= INP_IPV4;
-        inp->inp_ip_p = IPPROTO_ICMP;
-        inp->inp_ip_ttl = ip_defttl;
-        return 0;
+       struct inpcb *inp;
+       int error;
+
+       inp = sotoinpcb(so);
+       if (inp) {
+               panic("icmp_dgram_attach");
+       }
+
+       error = soreserve(so, rip_sendspace, rip_recvspace);
+       if (error) {
+               return error;
+       }
+       error = in_pcballoc(so, &ripcbinfo, p);
+       if (error) {
+               return error;
+       }
+       inp = (struct inpcb *)so->so_pcb;
+       inp->inp_vflag |= INP_IPV4;
+       inp->inp_ip_p = IPPROTO_ICMP;
+       inp->inp_ip_ttl = (u_char)ip_defttl;
+       return 0;
 }
 
 /*
@@ -1111,46 +1233,45 @@ icmp_dgram_attach(struct socket *so, __unused int proto, struct proc *p)
 __private_extern__ int
 icmp_dgram_ctloutput(struct socket *so, struct sockopt *sopt)
 {
-       int     error;
+       int     error;
 
-       if (sopt->sopt_level != IPPROTO_IP)
-               return (EINVAL);
+       if (sopt->sopt_level != IPPROTO_IP) {
+               return EINVAL;
+       }
 
        switch (sopt->sopt_name) {
-               case IP_OPTIONS:
-               case IP_HDRINCL:
-               case IP_TOS:
-               case IP_TTL:
-               case IP_RECVOPTS:
-               case IP_RECVRETOPTS:
-               case IP_RECVDSTADDR:
-               case IP_RETOPTS:
-               case IP_MULTICAST_IF:
-               case IP_MULTICAST_IFINDEX:
-               case IP_MULTICAST_TTL:
-               case IP_MULTICAST_LOOP:
-               case IP_ADD_MEMBERSHIP:
-               case IP_DROP_MEMBERSHIP:
-               case IP_MULTICAST_VIF:
-               case IP_PORTRANGE:
-               case IP_RECVIF:
-               case IP_IPSEC_POLICY:
-               case IP_STRIPHDR:
-               case IP_RECVTTL:
-               case IP_BOUND_IF:
-#if CONFIG_FORCE_OUT_IFP
-                case IP_FORCE_OUT_IFP:
-#endif
-               case IP_NO_IFT_CELLULAR:
-                       error = rip_ctloutput(so, sopt);
-                       break;
+       case IP_OPTIONS:
+       case IP_HDRINCL:
+       case IP_TOS:
+       case IP_TTL:
+       case IP_RECVOPTS:
+       case IP_RECVRETOPTS:
+       case IP_RECVDSTADDR:
+       case IP_RETOPTS:
+       case IP_MULTICAST_IF:
+       case IP_MULTICAST_IFINDEX:
+       case IP_MULTICAST_TTL:
+       case IP_MULTICAST_LOOP:
+       case IP_ADD_MEMBERSHIP:
+       case IP_DROP_MEMBERSHIP:
+       case IP_MULTICAST_VIF:
+       case IP_PORTRANGE:
+       case IP_RECVIF:
+       case IP_IPSEC_POLICY:
+       case IP_STRIPHDR:
+       case IP_RECVTTL:
+       case IP_BOUND_IF:
+       case IP_DONTFRAG:
+       case IP_NO_IFT_CELLULAR:
+               error = rip_ctloutput(so, sopt);
+               break;
 
-               default:
-                       error = EINVAL;
-                       break;
+       default:
+               error = EINVAL;
+               break;
        }
 
-       return (error);
+       return error;
 }
 
 __private_extern__ int
@@ -1161,21 +1282,32 @@ icmp_dgram_send(struct socket *so, int flags, struct mbuf *m,
        struct inpcb *inp = sotoinpcb(so);
        int hlen;
        struct icmp *icp;
-        struct in_ifaddr *ia = NULL;
+       struct in_ifaddr *ia = NULL;
        int icmplen;
        int error = EINVAL;
+       int inp_flags = inp ? inp->inp_flags : 0;
 
        if (inp == NULL
 #if NECP
-               || (necp_socket_should_use_flow_divert(inp))
+           || (necp_socket_should_use_flow_divert(inp))
 #endif /* NECP */
-               ) {
-               if (inp != NULL)
+           ) {
+               if (inp != NULL) {
                        error = EPROTOTYPE;
+               }
                goto bad;
        }
 
-       if ((inp->inp_flags & INP_HDRINCL) != 0) {
+#if CONTENT_FILTER
+       /*
+        * If socket is subject to Content Filter, get inp_flags from saved state
+        */
+       if (so->so_cfil_db && nam == NULL) {
+               cfil_dgram_peek_socket_state(m, &inp_flags);
+       }
+#endif
+
+       if ((inp_flags & INP_HDRINCL) != 0) {
                /* Expect 32-bit aligned data ptr on strict-align platforms */
                MBUF_STRICT_DATA_ALIGNMENT_CHECK_32(m);
                /*
@@ -1190,16 +1322,20 @@ icmp_dgram_send(struct socket *so, int flags, struct mbuf *m,
                        goto bad;
                }
                /* Only IPv4 */
-               if (IP_VHL_V(ip->ip_vhl) != 4)
+               if (IP_VHL_V(ip->ip_vhl) != 4) {
                        goto bad;
-               if (hlen < 20 || hlen > 40 || ip->ip_len != m->m_pkthdr.len)
+               }
+               if (hlen < 20 || hlen > 40 || ip->ip_len != m->m_pkthdr.len) {
                        goto bad;
+               }
                /* Bogus fragments can tie up peer resources */
-               if ((ip->ip_off & ~IP_DF) !=  0)
+               if ((ip->ip_off & ~IP_DF) != 0) {
                        goto bad;
+               }
                /* Allow only ICMP even for user provided IP header */
-               if (ip->ip_p != IPPROTO_ICMP)
+               if (ip->ip_p != IPPROTO_ICMP) {
                        goto bad;
+               }
                /*
                 * To prevent spoofing, specified source address must
                 * be one of ours.
@@ -1243,32 +1379,37 @@ ours:
        /*
         * Allow only to send request types with code 0
         */
-       if (icp->icmp_code != 0)
+       if (icp->icmp_code != 0) {
                goto bad;
+       }
        switch (icp->icmp_type) {
-               case ICMP_ECHO:
-                       break;
-               case ICMP_TSTAMP:
-                       if (icmplen != 20)
-                               goto bad;
-                       break;
-               case ICMP_MASKREQ:
-                       if (icmplen != 12)
-                               goto bad;
-                       break;
-               default:
+       case ICMP_ECHO:
+               break;
+       case ICMP_TSTAMP:
+               if (icmplen != 20) {
+                       goto bad;
+               }
+               break;
+       case ICMP_MASKREQ:
+               if (icmplen != 12) {
                        goto bad;
+               }
+               break;
+       default:
+               goto bad;
        }
-       return (rip_send(so, flags, m, nam, control, p));
+       return rip_send(so, flags, m, nam, control, p);
 bad:
        VERIFY(error != 0);
 
-       if (m != NULL)
+       if (m != NULL) {
                m_freem(m);
-       if (control != NULL)
+       }
+       if (control != NULL) {
                m_freem(control);
+       }
 
-       return (error);
+       return error;
 }
 
 #endif /* __APPLE__ */