mDNSResponder-258.13.tar.gz

[apple/mdnsresponder.git] / mDNSMacOSX / helper.c

/* -*- Mode: C; tab-width: 4 -*-
 *
 * Copyright (c) 2007 Apple Inc. All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include <sys/cdefs.h>
#include <arpa/inet.h>
#include <bsm/libbsm.h>
#include <net/if.h>
#include <net/route.h>
#include <net/if_dl.h>
#include <net/if_types.h>
#include <netinet/in.h>
#include <netinet/if_ether.h>
#include <netinet6/in6_var.h>
#include <netinet6/nd6.h>
#include <netinet6/ipsec.h>
#include <sys/ioctl.h>
#include <sys/param.h>
#include <sys/socket.h>
#include <asl.h>
#include <ctype.h>
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <signal.h>
#include <stdarg.h>
#include <stdbool.h>
#include <string.h>
#include <unistd.h>
#include <Security/Security.h>
#include <SystemConfiguration/SystemConfiguration.h>
#include <SystemConfiguration/SCDynamicStore.h>
#include <SystemConfiguration/SCPreferencesSetSpecific.h>
#include <SystemConfiguration/SCDynamicStoreCopySpecific.h>
#include <TargetConditionals.h>
#include <IOKit/pwr_mgt/IOPMLib.h>

#include "mDNSEmbeddedAPI.h"
#include "dns_sd.h"
#include "dnssd_ipc.h"
#include "libpfkey.h"
#include "helper.h"
#include "helpermsgServer.h"
#include "helper-server.h"
#include "ipsec_options.h"

#ifndef RTF_IFSCOPE
#define RTF_IFSCOPE 0x1000000
#endif

#if TARGET_OS_EMBEDDED
#ifndef MDNS_NO_IPSEC
#define MDNS_NO_IPSEC 1
#endif
#define NO_CFUSERNOTIFICATION 1
#define NO_SECURITYFRAMEWORK 1
#endif

// Embed the client stub code here, so we can access private functions like ConnectToServer, create_hdr, deliver_request
#include "../mDNSShared/dnssd_ipc.c"
#include "../mDNSShared/dnssd_clientstub.c"

typedef struct sadb_x_policy *ipsec_policy_t;

uid_t mDNSResponderUID;
gid_t mDNSResponderGID;
static const char kTunnelAddressInterface[] = "lo0";

void
debug_(const char *func, const char *fmt, ...)
        {
        char buf[2048];
        va_list ap;

        va_start(ap, fmt);
        vsnprintf(buf, sizeof(buf), fmt, ap);
        va_end(ap);
        helplog(ASL_LEVEL_DEBUG, "%s: %s", func, buf);
        }

static int
authorized(audit_token_t *token)
        {
        int ok = 0;
        pid_t pid = (pid_t)-1;
        uid_t euid = (uid_t)-1;

        audit_token_to_au32(*token, NULL, &euid, NULL, NULL, NULL, &pid, NULL,
            NULL);
        ok = (euid == mDNSResponderUID || euid == 0);
        if (!ok)
                helplog(ASL_LEVEL_NOTICE,
                    "Unauthorized access by euid=%lu pid=%lu",
                    (unsigned long)euid, (unsigned long)pid);
        return ok;
        }

kern_return_t
do_mDNSExit(__unused mach_port_t port, audit_token_t token)
        {
        debug("entry");
        if (!authorized(&token))
                goto fin;
        helplog(ASL_LEVEL_INFO, "exit");
        exit(0);

fin:
        debug("fin");
        return KERN_SUCCESS;
        }

kern_return_t do_mDNSRequestBPF(__unused mach_port_t port, audit_token_t token)
        {
        if (!authorized(&token)) return KERN_SUCCESS;
        DNSServiceRef ref;
        DNSServiceErrorType err = ConnectToServer(&ref, 0, send_bpf, NULL, NULL, NULL);
        if (err) { helplog(ASL_LEVEL_ERR, "do_mDNSRequestBPF: ConnectToServer %d", err); return err; }
        
        char *ptr;
        size_t len = sizeof(DNSServiceFlags);
        ipc_msg_hdr *hdr = create_hdr(send_bpf, &len, &ptr, 0, ref);
        if (!hdr) { DNSServiceRefDeallocate(ref); return kDNSServiceErr_NoMemory; }
        put_flags(0, &ptr);
        deliver_request(hdr, ref);              // Will free hdr for us
        DNSServiceRefDeallocate(ref);
        update_idle_timer();
        return KERN_SUCCESS;
        }

kern_return_t do_mDNSPowerRequest(__unused mach_port_t port, int key, int interval, int *err, audit_token_t token)
        {
        *err = -1;
        if (!authorized(&token)) { *err = kmDNSHelperNotAuthorized; goto fin; }

        CFArrayRef events = IOPMCopyScheduledPowerEvents();
        if (events)
                {
                int i;
                CFIndex count = CFArrayGetCount(events);
                for (i=0; i<count; i++)
                        {
                        CFDictionaryRef dict = CFArrayGetValueAtIndex(events, i);
                        CFStringRef id = CFDictionaryGetValue(dict, CFSTR(kIOPMPowerEventAppNameKey));
                        if (CFEqual(id, CFSTR("mDNSResponderHelper")))
                                {
                                CFDateRef   EventTime = CFDictionaryGetValue(dict, CFSTR(kIOPMPowerEventTimeKey));
                                CFStringRef EventType = CFDictionaryGetValue(dict, CFSTR(kIOPMPowerEventTypeKey));
                                IOReturn result = IOPMCancelScheduledPowerEvent(EventTime, id, EventType);
                                //helplog(ASL_LEVEL_ERR, "Deleting old event %s");
                                if (result) helplog(ASL_LEVEL_ERR, "IOPMCancelScheduledPowerEvent %d failed %d", i, result);
                                }
                        }
                CFRelease(events);
                }

        if (key < 0)                    // mDNSPowerRequest(-1,-1) means "clear any stale schedules" (see above)
                *err = 0;
        else if (key == 0)              // mDNSPowerRequest(0, 0) means "sleep now"
                {
                IOReturn r = IOPMSleepSystem(IOPMFindPowerManagement(MACH_PORT_NULL));
                if (r) { usleep(100000); helplog(ASL_LEVEL_ERR, "IOPMSleepSystem %d", r); }
                *err = r;
                }
        else if (key > 0)
                {
                CFDateRef w = CFDateCreate(NULL, CFAbsoluteTimeGetCurrent() + interval);
                if (w)
                        {
                        IOReturn r = IOPMSchedulePowerEvent(w, CFSTR("mDNSResponderHelper"), key ? CFSTR(kIOPMAutoWake) : CFSTR(kIOPMAutoSleep));
                        if (r) { usleep(100000); helplog(ASL_LEVEL_ERR, "IOPMSchedulePowerEvent(%d) %d %x", interval, r, r); }
                        *err = r;
                        CFRelease(w);
                        }
                }
fin:
        update_idle_timer();
        return KERN_SUCCESS;
        }

kern_return_t do_mDNSSetLocalAddressCacheEntry(__unused mach_port_t port, int ifindex, int family, v6addr_t ip, ethaddr_t eth, int *err, audit_token_t token)
        {
        #define IPv6FMTSTRING "%02X%02X:%02X%02X:%02X%02X:%02X%02X:%02X%02X:%02X%02X:%02X%02X:%02X%02X"
        #define IPv6FMTARGS  ip[0], ip[1], ip[2], ip[3], ip[4], ip[5], ip[6], ip[7], ip[8], ip[9], ip[10], ip[11], ip[12], ip[13], ip[14], ip[15] 
        #if 0
        if (family == 4)
                helplog(ASL_LEVEL_ERR, "do_mDNSSetLocalAddressCacheEntry %d IPv%d %d.%d.%d.%d %02X:%02X:%02X:%02X:%02X:%02X",
                        ifindex, family, ip[0], ip[1], ip[2], ip[3], eth[0], eth[1], eth[2], eth[3], eth[4], eth[5]);
        else
                helplog(ASL_LEVEL_ERR, "do_mDNSSetLocalAddressCacheEntry %d IPv%d " IPv6FMTSTRING " %02X:%02X:%02X:%02X:%02X:%02X",
                        ifindex, family, IPv6FMTARGS, eth[0], eth[1], eth[2], eth[3], eth[4], eth[5]);
        #endif

        *err = -1;
        if (!authorized(&token)) { *err = kmDNSHelperNotAuthorized; goto fin; }

        static int s = -1, seq = 0;
        if (s < 0)
                {
                s = socket(PF_ROUTE, SOCK_RAW, 0);
                if (s < 0) helplog(ASL_LEVEL_ERR, "do_mDNSSetLocalAddressCacheEntry: socket(PF_ROUTE, SOCK_RAW, 0) failed %d (%s)", errno, strerror(errno));
                }

        if (s >= 0)
                {
                struct timeval tv;
                gettimeofday(&tv, 0);
                if (family == 4)
                        {
                        struct { struct rt_msghdr hdr; struct sockaddr_inarp dst; struct sockaddr_dl sdl; } rtmsg;
                        memset(&rtmsg, 0, sizeof(rtmsg));

                        rtmsg.hdr.rtm_msglen         = sizeof(rtmsg);
                        rtmsg.hdr.rtm_version        = RTM_VERSION;
                        rtmsg.hdr.rtm_type           = RTM_ADD;
                        rtmsg.hdr.rtm_index          = ifindex;
                        rtmsg.hdr.rtm_flags          = RTF_HOST | RTF_STATIC | RTF_IFSCOPE;
                        rtmsg.hdr.rtm_addrs          = RTA_DST | RTA_GATEWAY;
                        rtmsg.hdr.rtm_pid            = 0;
                        rtmsg.hdr.rtm_seq            = seq++;
                        rtmsg.hdr.rtm_errno          = 0;
                        rtmsg.hdr.rtm_use            = 0;
                        rtmsg.hdr.rtm_inits          = RTV_EXPIRE;
                        rtmsg.hdr.rtm_rmx.rmx_expire = tv.tv_sec + 30;

                        rtmsg.dst.sin_len            = sizeof(rtmsg.dst);
                        rtmsg.dst.sin_family         = AF_INET;
                        rtmsg.dst.sin_port           = 0;
                        rtmsg.dst.sin_addr.s_addr    = *(in_addr_t*)ip;
                        rtmsg.dst.sin_srcaddr.s_addr = 0;
                        rtmsg.dst.sin_tos            = 0;
                        rtmsg.dst.sin_other          = 0;

                        rtmsg.sdl.sdl_len            = sizeof(rtmsg.sdl);
                        rtmsg.sdl.sdl_family         = AF_LINK;
                        rtmsg.sdl.sdl_index          = ifindex;
                        rtmsg.sdl.sdl_type           = IFT_ETHER;
                        rtmsg.sdl.sdl_nlen           = 0;
                        rtmsg.sdl.sdl_alen           = ETHER_ADDR_LEN;
                        rtmsg.sdl.sdl_slen           = 0;

                        // Target MAC address goes in rtmsg.sdl.sdl_data[0..5]; (See LLADDR() in /usr/include/net/if_dl.h)
                        memcpy(rtmsg.sdl.sdl_data, eth, sizeof(ethaddr_t));

                        int len = write(s, (char *)&rtmsg, sizeof(rtmsg));
                        if (len < 0)
                                helplog(ASL_LEVEL_ERR, "do_mDNSSetLocalAddressCacheEntry: write(%d) interface %d address %d.%d.%d.%d seq %d result %d errno %d (%s)",
                                        sizeof(rtmsg), ifindex, ip[0], ip[1], ip[2], ip[3], rtmsg.hdr.rtm_seq, len, errno, strerror(errno));
                        len = read(s, (char *)&rtmsg, sizeof(rtmsg));
                        if (len < 0 || rtmsg.hdr.rtm_errno)
                                helplog(ASL_LEVEL_ERR, "do_mDNSSetLocalAddressCacheEntry: read (%d) interface %d address %d.%d.%d.%d seq %d result %d errno %d (%s) %d",
                                        sizeof(rtmsg), ifindex, ip[0], ip[1], ip[2], ip[3], rtmsg.hdr.rtm_seq, len, errno, strerror(errno), rtmsg.hdr.rtm_errno);

                        *err = 0;
                        }
                else
                        {
                        struct { struct rt_msghdr hdr; struct sockaddr_in6 dst; struct sockaddr_dl sdl; } rtmsg;
                        memset(&rtmsg, 0, sizeof(rtmsg));

                        rtmsg.hdr.rtm_msglen         = sizeof(rtmsg);
                        rtmsg.hdr.rtm_version        = RTM_VERSION;
                        rtmsg.hdr.rtm_type           = RTM_ADD;
                        rtmsg.hdr.rtm_index          = ifindex;
                        rtmsg.hdr.rtm_flags          = RTF_HOST | RTF_STATIC | RTF_IFSCOPE;
                        rtmsg.hdr.rtm_addrs          = RTA_DST | RTA_GATEWAY;
                        rtmsg.hdr.rtm_pid            = 0;
                        rtmsg.hdr.rtm_seq            = seq++;
                        rtmsg.hdr.rtm_errno          = 0;
                        rtmsg.hdr.rtm_use            = 0;
                        rtmsg.hdr.rtm_inits          = RTV_EXPIRE;
                        rtmsg.hdr.rtm_rmx.rmx_expire = tv.tv_sec + 30;

                        rtmsg.dst.sin6_len           = sizeof(rtmsg.dst);
                        rtmsg.dst.sin6_family        = AF_INET6;
                        rtmsg.dst.sin6_port          = 0;
                        rtmsg.dst.sin6_flowinfo      = 0;
                        rtmsg.dst.sin6_addr          = *(struct in6_addr*)ip;
                        rtmsg.dst.sin6_scope_id      = ifindex;

                        rtmsg.sdl.sdl_len            = sizeof(rtmsg.sdl);
                        rtmsg.sdl.sdl_family         = AF_LINK;
                        rtmsg.sdl.sdl_index          = ifindex;
                        rtmsg.sdl.sdl_type           = IFT_ETHER;
                        rtmsg.sdl.sdl_nlen           = 0;
                        rtmsg.sdl.sdl_alen           = ETHER_ADDR_LEN;
                        rtmsg.sdl.sdl_slen           = 0;

                        // Target MAC address goes in rtmsg.sdl.sdl_data[0..5]; (See LLADDR() in /usr/include/net/if_dl.h)
                        memcpy(rtmsg.sdl.sdl_data, eth, sizeof(ethaddr_t));

                        int len = write(s, (char *)&rtmsg, sizeof(rtmsg));
                        if (len < 0)
                                helplog(ASL_LEVEL_ERR, "do_mDNSSetLocalAddressCacheEntry: write(%d) interface %d address " IPv6FMTSTRING " seq %d result %d errno %d (%s)",
                                        sizeof(rtmsg), ifindex, IPv6FMTARGS, rtmsg.hdr.rtm_seq, len, errno, strerror(errno));
                        len = read(s, (char *)&rtmsg, sizeof(rtmsg));
                        if (len < 0 || rtmsg.hdr.rtm_errno)
                                helplog(ASL_LEVEL_ERR, "do_mDNSSetLocalAddressCacheEntry: read (%d) interface %d address " IPv6FMTSTRING " seq %d result %d errno %d (%s) %d",
                                        sizeof(rtmsg), ifindex, IPv6FMTARGS, rtmsg.hdr.rtm_seq, len, errno, strerror(errno), rtmsg.hdr.rtm_errno);

                        *err = 0;
                        }

                }

fin:
        update_idle_timer();
        return KERN_SUCCESS;
        }

kern_return_t do_mDNSNotify(__unused mach_port_t port, const char *title, const char *msg, audit_token_t token)
        {
        if (!authorized(&token)) return KERN_SUCCESS;

#ifndef NO_CFUSERNOTIFICATION
        static const char footer[] = "(Note: This message only appears on machines with 17.x.x.x IP addresses — i.e. at Apple — not on customer machines.)";
        CFStringRef alertHeader  = CFStringCreateWithCString(NULL, title,  kCFStringEncodingUTF8);
        CFStringRef alertBody    = CFStringCreateWithCString(NULL, msg,    kCFStringEncodingUTF8);
        CFStringRef alertFooter  = CFStringCreateWithCString(NULL, footer, kCFStringEncodingUTF8);
        CFStringRef alertMessage = CFStringCreateWithFormat(NULL, NULL, CFSTR("%@\r\r%@"), alertBody, alertFooter);
        CFRelease(alertBody);
        CFRelease(alertFooter);
        int err = CFUserNotificationDisplayNotice(0.0, kCFUserNotificationStopAlertLevel, NULL, NULL, NULL, alertHeader, alertMessage, NULL);
        if (err) helplog(ASL_LEVEL_ERR, "CFUserNotificationDisplayNotice returned %d", err);
        CFRelease(alertHeader);
        CFRelease(alertMessage);
#else
        (void)title;
        (void)msg;
#endif /* NO_CFUSERNOTIFICATION */

        update_idle_timer();
        return KERN_SUCCESS;
        }

kern_return_t
do_mDNSDynamicStoreSetConfig(__unused mach_port_t port, int key,
    const char* subkey, vm_offset_t value, mach_msg_type_number_t valueCnt,
    audit_token_t token)
        {
        CFStringRef sckey = NULL;
        Boolean release_sckey = FALSE;
        CFDataRef bytes = NULL;
        CFPropertyListRef plist = NULL;
        SCDynamicStoreRef store = NULL;

        debug("entry");
        if (!authorized(&token)) goto fin;

        switch ((enum mDNSDynamicStoreSetConfigKey)key)
                {
                case kmDNSMulticastConfig:
                        sckey = CFSTR("State:/Network/" kDNSServiceCompMulticastDNS);
                        break;
                case kmDNSDynamicConfig:
                        sckey = CFSTR("State:/Network/DynamicDNS");
                        break;
                case kmDNSPrivateConfig:
                        sckey = CFSTR("State:/Network/" kDNSServiceCompPrivateDNS);
                        break;
                case kmDNSBackToMyMacConfig:
                        sckey = CFSTR("State:/Network/BackToMyMac");
                        break;
                case kmDNSSleepProxyServersState:
                        {
                        CFMutableStringRef tmp = CFStringCreateMutable(kCFAllocatorDefault, 0);
                        CFStringAppend(tmp, CFSTR("State:/Network/Interface/"));
                        CFStringAppendCString(tmp, subkey, kCFStringEncodingUTF8);
                        CFStringAppend(tmp, CFSTR("/SleepProxyServers"));
                        sckey = CFStringCreateCopy(kCFAllocatorDefault, tmp);
                        release_sckey = TRUE;
                        CFRelease(tmp);
                        break;
                        }
                default:
                        debug("unrecognized key %d", key);
                        goto fin;
                }
        if (NULL == (bytes = CFDataCreateWithBytesNoCopy(NULL, (void *)value,
            valueCnt, kCFAllocatorNull)))
                {
                debug("CFDataCreateWithBytesNoCopy of value failed");
                goto fin;
                }
        if (NULL == (plist = CFPropertyListCreateFromXMLData(NULL, bytes,
            kCFPropertyListImmutable, NULL)))
                {
                debug("CFPropertyListCreateFromXMLData of bytes failed");
                goto fin;
                }
        CFRelease(bytes);
        bytes = NULL;
        if (NULL == (store = SCDynamicStoreCreate(NULL,
            CFSTR(kmDNSHelperServiceName), NULL, NULL)))
                {
                debug("SCDynamicStoreCreate failed: %s", SCErrorString(SCError()));
                goto fin;
                }
        SCDynamicStoreSetValue(store, sckey, plist);
        debug("succeeded");

fin:
        if (NULL != bytes)
                CFRelease(bytes);
        if (NULL != plist)
                CFRelease(plist);
        if (NULL != store)
                CFRelease(store);
        if (release_sckey && sckey)
                CFRelease(sckey);
        vm_deallocate(mach_task_self(), value, valueCnt);
        update_idle_timer();
        return KERN_SUCCESS;
        }

char usercompname[MAX_DOMAIN_LABEL+1] = {0}; // the last computer name the user saw
char userhostname[MAX_DOMAIN_LABEL+1] = {0}; // the last local host name the user saw
char lastcompname[MAX_DOMAIN_LABEL+1] = {0}; // the last computer name saved to preferences
char lasthostname[MAX_DOMAIN_LABEL+1] = {0}; // the last local host name saved to preferences

#ifndef NO_CFUSERNOTIFICATION
static CFStringRef CFS_OQ = NULL;
static CFStringRef CFS_CQ = NULL;
static CFStringRef CFS_Format = NULL;
static CFStringRef CFS_ComputerName = NULL;
static CFStringRef CFS_ComputerNameMsg = NULL;
static CFStringRef CFS_LocalHostName = NULL;
static CFStringRef CFS_LocalHostNameMsg = NULL;
static CFStringRef CFS_Problem = NULL;

static CFUserNotificationRef gNotification    = NULL;
static CFRunLoopSourceRef    gNotificationRLS = NULL;

static void NotificationCallBackDismissed(CFUserNotificationRef userNotification, CFOptionFlags responseFlags)
        {
        debug("entry");
        (void)responseFlags;    // Unused
        if (userNotification != gNotification) helplog(ASL_LEVEL_ERR, "NotificationCallBackDismissed: Wrong CFUserNotificationRef");
        if (gNotificationRLS)
                {
                // Caution: don't use CFRunLoopGetCurrent() here, because the currently executing thread may not be our "CFRunLoopRun" thread.
                // We need to explicitly specify the desired CFRunLoop from which we want to remove this event source.
                CFRunLoopRemoveSource(gRunLoop, gNotificationRLS, kCFRunLoopDefaultMode);
                CFRelease(gNotificationRLS);
                gNotificationRLS = NULL;
                CFRelease(gNotification);
                gNotification = NULL;
                }
        // By dismissing the alert, the user has conceptually acknowleged the rename.
        // (e.g. the machine's name is now officially "computer-2.local", not "computer.local".)
        // If we get *another* conflict, the new alert should refer to the 'old' name
        // as now being "computer-2.local", not "computer.local"
        usercompname[0] = 0;
        userhostname[0] = 0;
        lastcompname[0] = 0;
        lasthostname[0] = 0;
        update_idle_timer();
        unpause_idle_timer();
        }

static void ShowNameConflictNotification(CFMutableArrayRef header, CFStringRef subtext)
        {
        CFMutableDictionaryRef dictionary = CFDictionaryCreateMutable(NULL, 0, &kCFTypeDictionaryKeyCallBacks, &kCFTypeDictionaryValueCallBacks);
        if (!dictionary) return;

        debug("entry");

        CFDictionarySetValue(dictionary, kCFUserNotificationAlertHeaderKey, header);
        CFDictionarySetValue(dictionary, kCFUserNotificationAlertMessageKey, subtext);

        CFURLRef urlRef = CFURLCreateWithFileSystemPath(NULL, CFSTR("/System/Library/CoreServices/mDNSResponder.bundle"), kCFURLPOSIXPathStyle, true);
        if (urlRef) { CFDictionarySetValue(dictionary, kCFUserNotificationLocalizationURLKey, urlRef); CFRelease(urlRef); }

        if (gNotification)      // If notification already on-screen, update it in place
                CFUserNotificationUpdate(gNotification, 0, kCFUserNotificationCautionAlertLevel, dictionary);
        else                            // else, we need to create it
                {
                SInt32 error;
                gNotification = CFUserNotificationCreate(NULL, 0, kCFUserNotificationCautionAlertLevel, &error, dictionary);
                if (!gNotification || error) { helplog(ASL_LEVEL_ERR, "ShowNameConflictNotification: CFUserNotificationRef: Error %d", error); return; }
                gNotificationRLS = CFUserNotificationCreateRunLoopSource(NULL, gNotification, NotificationCallBackDismissed, 0);
                if (!gNotificationRLS) { helplog(ASL_LEVEL_ERR,"ShowNameConflictNotification: RLS"); CFRelease(gNotification); gNotification = NULL; return; }
                // Caution: don't use CFRunLoopGetCurrent() here, because the currently executing thread may not be our "CFRunLoopRun" thread.
                // We need to explicitly specify the desired CFRunLoop to which we want to add this event source.
                CFRunLoopAddSource(gRunLoop, gNotificationRLS, kCFRunLoopDefaultMode);
                debug("gRunLoop=%p gNotification=%p gNotificationRLS=%p", gRunLoop, gNotification, gNotificationRLS);
                pause_idle_timer();
                }

        CFRelease(dictionary);
        }

static CFMutableArrayRef GetHeader(const char* oldname, const char* newname, const CFStringRef msg, const char* suffix)
        {
        CFMutableArrayRef alertHeader = NULL;

        const CFStringRef cfoldname = CFStringCreateWithCString(NULL, oldname,  kCFStringEncodingUTF8);
        // NULL newname means we've given up trying to construct a name that doesn't conflict
        const CFStringRef cfnewname = newname ? CFStringCreateWithCString(NULL, newname,  kCFStringEncodingUTF8) : NULL;
        // We tag a zero-width non-breaking space at the end of the literal text to guarantee that, no matter what
        // arbitrary computer name the user may choose, this exact text (with zero-width non-breaking space added)
        // can never be one that occurs in the Localizable.strings translation file.
        if (!cfoldname)
                helplog(ASL_LEVEL_ERR,"Could not construct CFStrings for old=%s", newname);
        else if (newname && !cfnewname)
                helplog(ASL_LEVEL_ERR,"Could not construct CFStrings for new=%s", newname);
        else
                {
                const CFStringRef s1 = CFStringCreateWithFormat(NULL, NULL, CFS_Format, cfoldname, suffix);
                const CFStringRef s2 = cfnewname ? CFStringCreateWithFormat(NULL, NULL, CFS_Format, cfnewname, suffix) : NULL;

                alertHeader = CFArrayCreateMutable(NULL, 0, &kCFTypeArrayCallBacks);

                if (!s1)
                        helplog(ASL_LEVEL_ERR, "Could not construct secondary CFString for old=%s", oldname);
                else if (cfnewname && !s2)
                        helplog(ASL_LEVEL_ERR, "Could not construct secondary CFString for new=%s", newname);
                else if (!alertHeader)
                        helplog(ASL_LEVEL_ERR, "Could not construct CFArray for notification");
                else
                        {
                        // Make sure someone is logged in.  We don't want this popping up over the login window
                        uid_t uid;
                        gid_t gid;
                        CFStringRef userName = SCDynamicStoreCopyConsoleUser(NULL, &uid, &gid);
                        if (userName)
                                {
                                CFRelease(userName);
                                CFArrayAppendValue(alertHeader, msg); // Opening phrase of message, provided by caller
                                CFArrayAppendValue(alertHeader, CFS_OQ); CFArrayAppendValue(alertHeader, s1); CFArrayAppendValue(alertHeader, CFS_CQ);
                                CFArrayAppendValue(alertHeader, CFSTR(" is already in use on this network. "));
                                if (s2)
                                        {
                                        CFArrayAppendValue(alertHeader, CFSTR("The name has been changed to "));
                                        CFArrayAppendValue(alertHeader, CFS_OQ); CFArrayAppendValue(alertHeader, s2); CFArrayAppendValue(alertHeader, CFS_CQ);
                                        CFArrayAppendValue(alertHeader, CFSTR("."));
                                        }
                                else
                                        CFArrayAppendValue(alertHeader, CFSTR("All attempts to find an available name by adding a number to the name were also unsuccessful."));
                                }
                        }
                if (s1)          CFRelease(s1);
                if (s2)          CFRelease(s2);
                }
        if (cfoldname) CFRelease(cfoldname);
        if (cfnewname) CFRelease(cfnewname);

        return alertHeader;
        }
#endif /* ndef NO_CFUSERNOTIFICATION */

static void update_notification(void)
        {
#ifndef NO_CFUSERNOTIFICATION
        debug("entry ucn=%s, uhn=%s, lcn=%s, lhn=%s", usercompname, userhostname, lastcompname, lasthostname);
        if (!CFS_OQ)
                {
                // Note: the "\xEF\xBB\xBF" byte sequence in the CFS_Format string is the UTF-8 encoding of the zero-width non-breaking space character.
                // By appending this invisible character on the end of literal names, we ensure the these strings cannot inadvertently match any string
                // in the localization file -- since we know for sure that none of our strings in the localization file contain the ZWNBS character.
                CFS_OQ               = CFStringCreateWithCString(NULL, "“",  kCFStringEncodingUTF8);
                CFS_CQ               = CFStringCreateWithCString(NULL, "”",  kCFStringEncodingUTF8);
                CFS_Format           = CFStringCreateWithCString(NULL, "%@%s\xEF\xBB\xBF", kCFStringEncodingUTF8);
                CFS_ComputerName     = CFStringCreateWithCString(NULL, "The name of your computer ",  kCFStringEncodingUTF8);
                CFS_ComputerNameMsg  = CFStringCreateWithCString(NULL, "To change the name of your computer, "
                        "open System Preferences and click Sharing, then type the name in the Computer Name field.",  kCFStringEncodingUTF8);
                CFS_LocalHostName    = CFStringCreateWithCString(NULL, "This computer’s local hostname ",  kCFStringEncodingUTF8);
                CFS_LocalHostNameMsg = CFStringCreateWithCString(NULL, "To change the local hostname, "
                        "open System Preferences and click Sharing, then click “Edit” and type the name in the Local Hostname field.",  kCFStringEncodingUTF8);
                CFS_Problem          = CFStringCreateWithCString(NULL, "This may indicate a problem with the local network. "
                        "Please inform your network administrator.",  kCFStringEncodingUTF8);
                }

        if (!usercompname[0] && !userhostname[0])
                {
                if (gNotificationRLS)
                        {
                        debug("canceling notification %p", gNotification);
                        CFUserNotificationCancel(gNotification);
                        unpause_idle_timer();
                        }
                }
        else
                {
                CFMutableArrayRef header = NULL;
                CFStringRef* subtext = NULL;
                if (userhostname[0] && !lasthostname[0]) // we've given up trying to construct a name that doesn't conflict
                        {
                        header = GetHeader(userhostname, NULL, CFS_LocalHostName, ".local");
                        subtext = &CFS_Problem;
                        }
                else if (usercompname[0])
                        {
                        header = GetHeader(usercompname, lastcompname, CFS_ComputerName, "");
                        subtext = &CFS_ComputerNameMsg;
                        }
                else
                        {
                        header = GetHeader(userhostname, lasthostname, CFS_LocalHostName, ".local");
                        subtext = &CFS_LocalHostNameMsg;
                        }       
                ShowNameConflictNotification(header, *subtext);
                CFRelease(header);
                }
#endif
        }

kern_return_t
do_mDNSPreferencesSetName(__unused mach_port_t port, int key, const char* old, const char* new, audit_token_t token)
        {
        SCPreferencesRef session = NULL;
        Boolean ok = FALSE;
        Boolean locked = FALSE;
        CFStringRef cfstr = NULL;
        char* user = NULL;
        char* last = NULL;
        Boolean needUpdate = FALSE;

        debug("entry %s old=%s new=%s", key==kmDNSComputerName ? "ComputerName" : (key==kmDNSLocalHostName ? "LocalHostName" : "UNKNOWN"), old, new);
        if (!authorized(&token)) goto fin;

        switch ((enum mDNSPreferencesSetNameKey)key)
                {
                case kmDNSComputerName:
                        user = usercompname;
                        last = lastcompname;
                        break;
                case kmDNSLocalHostName:
                        user = userhostname;
                        last = lasthostname;
                        break;
                default:
                        debug("unrecognized key: %d", key);
                        goto fin;
                }

        if (!last)
                {
                helplog(ASL_LEVEL_ERR, "%s: no last ptr", __func__);
                goto fin;
                }

        if (!user)
                {
                helplog(ASL_LEVEL_ERR, "%s: no user ptr", __func__);
                goto fin;
                }

        if (0 == strncmp(old, new, MAX_DOMAIN_LABEL+1))
                {
                // old and new are same means the config changed i.e, the user has set something in the preferences pane.
                // This means the conflict has been resolved. We need to dismiss the dialogue.
                if (last[0] && 0 != strncmp(last, new, MAX_DOMAIN_LABEL+1))
                        {
                        last[0] = 0;
                        user[0] = 0;
                        needUpdate = TRUE;
                        }
                goto fin;
                }
        else
                {
                // old and new are not same, this means there is a conflict. For the first conflict, we show
                // the old value and the new value. For all subsequent conflicts, while the dialogue is still
                // up, we do a real time update of the "new" value in the dialogue. That's why we update just
                // "last" here and not "user".
                if (strncmp(last, new, MAX_DOMAIN_LABEL+1))
                        {
                        strncpy(last, new, MAX_DOMAIN_LABEL);
                        needUpdate = TRUE;
                        }
                }

        // If we are not showing the dialogue, we need to remember the first "old" value so that
        // we maintain the same through the lifetime of the dialogue. Subsequence conflicts don't
        // update the "old" value.
        if (!user[0])
                {
                strncpy(user, old, MAX_DOMAIN_LABEL);
                needUpdate = TRUE;
                }

        if (!new[0]) // we've given up trying to construct a name that doesn't conflict
                goto fin;

        cfstr = CFStringCreateWithCString(NULL, new, kCFStringEncodingUTF8);

        session = SCPreferencesCreate(NULL, CFSTR(kmDNSHelperServiceName), NULL);

        if (cfstr == NULL || session == NULL)
                {
                debug("SCPreferencesCreate failed");
                goto fin;
                }
        if (!SCPreferencesLock(session, 0))
                {
                debug("lock failed");
                goto fin;
                }
        locked = TRUE;

        switch ((enum mDNSPreferencesSetNameKey)key)
        {
        case kmDNSComputerName:
                {
                // We want to write the new Computer Name to System Preferences, without disturbing the user-selected
                // system-wide default character set used for things like AppleTalk NBP and NETBIOS service advertising.
                // Note that this encoding is not used for the computer name, but since both are set by the same call,
                // we need to take care to set the name without changing the character set.
                CFStringEncoding encoding = kCFStringEncodingUTF8;
                CFStringRef unused = SCDynamicStoreCopyComputerName(NULL, &encoding);
                if (unused) { CFRelease(unused); unused = NULL; }
                else encoding = kCFStringEncodingUTF8;
                
                ok = SCPreferencesSetComputerName(session, cfstr, encoding);
                }
                break;
        case kmDNSLocalHostName:
                ok = SCPreferencesSetLocalHostName(session, cfstr);
                break;
        default:
                break;
        }

        if (!ok || !SCPreferencesCommitChanges(session) ||
            !SCPreferencesApplyChanges(session))
                {
                debug("SCPreferences update failed");
                goto fin;
                }
        debug("succeeded");

fin:
        if (NULL != cfstr)
                CFRelease(cfstr);
        if (NULL != session)
                {
                if (locked)
                        SCPreferencesUnlock(session);
                CFRelease(session);
                }
        update_idle_timer();
        if (needUpdate) update_notification();
        return KERN_SUCCESS;
        }

enum DNSKeyFormat
        {
        formatNotDNSKey, formatDdnsTypeItem, formatDnsPrefixedServiceItem
        };

// On Mac OS X on Intel, the four-character string seems to be stored backwards, at least sometimes.
// I suspect some overenthusiastic inexperienced engineer said, "On Intel everything's backwards,
// therefore I need to add some byte swapping in this API to make this four-character string backwards too."
// To cope with this we allow *both* "ddns" and "sndd" as valid item types.

static const char dnsprefix[] = "dns:";
static const char ddns[] = "ddns";
static const char ddnsrev[] = "sndd";

#ifndef NO_SECURITYFRAMEWORK
static enum DNSKeyFormat
getDNSKeyFormat(SecKeychainItemRef item, SecKeychainAttributeList **attributesp)
        {
        static UInt32 tags[3] =
                {
                kSecTypeItemAttr, kSecServiceItemAttr, kSecAccountItemAttr
                };
        static SecKeychainAttributeInfo attributeInfo =
                {
                sizeof(tags)/sizeof(tags[0]), tags, NULL
                };
        SecKeychainAttributeList *attributes = NULL;
        enum DNSKeyFormat format;
        Boolean malformed = FALSE;
        OSStatus status = noErr;
        int i = 0;

        *attributesp = NULL;
        if (noErr != (status = SecKeychainItemCopyAttributesAndData(item,
            &attributeInfo, NULL, &attributes, NULL, NULL)))
                {
                debug("SecKeychainItemCopyAttributesAndData %d - skipping",
                    status);
                goto skip;
                }
        if (attributeInfo.count != attributes->count)
                malformed = TRUE;
        for (i = 0; !malformed && i < (int)attributeInfo.count; ++i)
                if (attributeInfo.tag[i] != attributes->attr[i].tag)
                        malformed = TRUE;
        if (malformed)
                {
                debug(
       "malformed result from SecKeychainItemCopyAttributesAndData - skipping");
                goto skip;
                }
        debug("entry (\"%.*s\", \"%.*s\", \"%.*s\")",
            (int)attributes->attr[0].length, attributes->attr[0].data,
            (int)attributes->attr[1].length, attributes->attr[1].data,
            (int)attributes->attr[2].length, attributes->attr[2].data);
        if (attributes->attr[1].length >= MAX_ESCAPED_DOMAIN_NAME +
            sizeof(dnsprefix)-1)
                {
                debug("kSecServiceItemAttr too long (%u) - skipping",
                    (unsigned int)attributes->attr[1].length);
                goto skip;
                }
        if (attributes->attr[2].length >= MAX_ESCAPED_DOMAIN_NAME)
                {
                debug("kSecAccountItemAttr too long (%u) - skipping",
                    (unsigned int)attributes->attr[2].length);
                goto skip;
                }
        if (attributes->attr[1].length >= sizeof(dnsprefix)-1 &&
            0 == strncasecmp(attributes->attr[1].data, dnsprefix,
            sizeof(dnsprefix)-1))
                format = formatDnsPrefixedServiceItem;
        else if (attributes->attr[0].length == sizeof(ddns)-1 &&
            0 == strncasecmp(attributes->attr[0].data, ddns, sizeof(ddns)-1))
                format = formatDdnsTypeItem;
        else if (attributes->attr[0].length == sizeof(ddnsrev)-1 &&
            0 == strncasecmp(attributes->attr[0].data, ddnsrev, sizeof(ddnsrev)-1))
                format = formatDdnsTypeItem;
        else
                {
                debug("uninterested in this entry");
                goto skip;
                }
        *attributesp = attributes;
        debug("accepting this entry");
        return format;

skip:
        SecKeychainItemFreeAttributesAndData(attributes, NULL);
        return formatNotDNSKey;
        }

static CFPropertyListRef
getKeychainItemInfo(SecKeychainItemRef item,
    SecKeychainAttributeList *attributes, enum DNSKeyFormat format)
        {
        CFMutableArrayRef entry = NULL;
        CFDataRef data = NULL;
        OSStatus status = noErr;
        UInt32 keylen = 0;
        void *keyp = 0;

        if (NULL == (entry = CFArrayCreateMutable(NULL, 0,
            &kCFTypeArrayCallBacks)))
                {
                debug("CFArrayCreateMutable failed");
                goto error;
                }
        switch ((enum DNSKeyFormat)format)
        {
        case formatDdnsTypeItem:
                data = CFDataCreate(kCFAllocatorDefault,
                    attributes->attr[1].data, attributes->attr[1].length);
                break;
        case formatDnsPrefixedServiceItem:
                data = CFDataCreate(kCFAllocatorDefault,
                    attributes->attr[1].data + sizeof(dnsprefix)-1,
                    attributes->attr[1].length - (sizeof(dnsprefix)-1));
        default:
                assert("unknown DNSKeyFormat value");
                break;
                }
        if (NULL == data)
                {
                debug("CFDataCreate for attr[1] failed");
                goto error;
                }
        CFArrayAppendValue(entry, data);
        CFRelease(data);
        if (NULL == (data = CFDataCreate(kCFAllocatorDefault,
            attributes->attr[2].data, attributes->attr[2].length)))
                {
                debug("CFDataCreate for attr[2] failed");
                goto error;
                }
        CFArrayAppendValue(entry, data);
        CFRelease(data);
        if (noErr != (status = SecKeychainItemCopyAttributesAndData(item, NULL,
            NULL, NULL, &keylen, &keyp)))
                {
                debug("could not retrieve key for \"%.*s\": %d",
                    (int)attributes->attr[1].length, attributes->attr[1].data,
                    status);
                goto error;
                }
        data = CFDataCreate(kCFAllocatorDefault, keyp, keylen);
        SecKeychainItemFreeAttributesAndData(NULL, keyp);
        if (NULL == data)
                {
                debug("CFDataCreate for keyp failed");
                goto error;
                }
        CFArrayAppendValue(entry, data);
        CFRelease(data);
        return entry;

error:
        if (NULL != entry)
                CFRelease(entry);
        return NULL;
        }
#endif

kern_return_t
do_mDNSKeychainGetSecrets(__unused mach_port_t port, __unused unsigned int *numsecrets,
    __unused vm_offset_t *secrets, __unused mach_msg_type_number_t *secretsCnt, __unused int *err,
    __unused audit_token_t token)
        {
#ifndef NO_SECURITYFRAMEWORK
        CFWriteStreamRef stream = NULL;
        CFDataRef result = NULL;
        CFPropertyListRef entry = NULL;
        CFMutableArrayRef keys = NULL;
        SecKeychainRef skc = NULL;
        SecKeychainItemRef item = NULL;
        SecKeychainSearchRef search = NULL;
        SecKeychainAttributeList *attributes = NULL;
        enum DNSKeyFormat format;
        OSStatus status = 0;

        debug("entry");
        *err = 0;
        *numsecrets = 0;
        *secrets = (vm_offset_t)NULL;
        if (!authorized(&token))
                {
                *err = kmDNSHelperNotAuthorized;
                goto fin;
                }
        if (NULL == (keys = CFArrayCreateMutable(NULL, 0,
            &kCFTypeArrayCallBacks)))
                {
                debug("CFArrayCreateMutable failed");
                *err = kmDNSHelperCreationFailed;
                goto fin;
                }
        if (noErr != (status = SecKeychainCopyDefault(&skc)))
                {
                *err = kmDNSHelperKeychainCopyDefaultFailed;
                goto fin;
                }
        if (noErr != (status = SecKeychainSearchCreateFromAttributes(skc, kSecGenericPasswordItemClass, NULL, &search)))
                {
                *err = kmDNSHelperKeychainSearchCreationFailed;
                goto fin;
                }
        for (status = SecKeychainSearchCopyNext(search, &item);
             noErr == status;
             status = SecKeychainSearchCopyNext(search, &item))
                {
                if (formatNotDNSKey != (format = getDNSKeyFormat(item,
                    &attributes)) &&
                    NULL != (entry = getKeychainItemInfo(item, attributes,
                    format)))
                        {
                        CFArrayAppendValue(keys, entry);
                        CFRelease(entry);
                        }
                SecKeychainItemFreeAttributesAndData(attributes, NULL);
                CFRelease(item);
                }
        if (errSecItemNotFound != status)
                helplog(ASL_LEVEL_ERR, "%s: SecKeychainSearchCopyNext failed: %d",
                    __func__, status);
        if (NULL == (stream =
            CFWriteStreamCreateWithAllocatedBuffers(kCFAllocatorDefault,
            kCFAllocatorDefault)))
                {
                *err = kmDNSHelperCreationFailed;
                debug("CFWriteStreamCreateWithAllocatedBuffers failed");
                goto fin;
                }
        CFWriteStreamOpen(stream);
        if (0 == CFPropertyListWriteToStream(keys, stream,
            kCFPropertyListBinaryFormat_v1_0, NULL))
                {
                *err = kmDNSHelperPListWriteFailed;
                debug("CFPropertyListWriteToStream failed");
                goto fin;
                }
        result = CFWriteStreamCopyProperty(stream,
            kCFStreamPropertyDataWritten);
        if (KERN_SUCCESS != vm_allocate(mach_task_self(), secrets,
            CFDataGetLength(result), VM_FLAGS_ANYWHERE))
                {
                *err = kmDNSHelperCreationFailed;
                debug("vm_allocate failed");
                goto fin;
                }
        CFDataGetBytes(result, CFRangeMake(0, CFDataGetLength(result)),
            (void *)*secrets);
        *secretsCnt = CFDataGetLength(result);
        *numsecrets = CFArrayGetCount(keys);
        debug("succeeded");

fin:
        debug("returning %u secrets", *numsecrets);
        if (NULL != stream)
                {
                CFWriteStreamClose(stream);
                CFRelease(stream);
                }
        if (NULL != result)
                CFRelease(result);
        if (NULL != keys)
                CFRelease(keys);
        if (NULL != search)
                CFRelease(search);
        if (NULL != skc)
                CFRelease(skc);
        update_idle_timer();
        return KERN_SUCCESS;
#else
        return KERN_FAILURE;
#endif
        }

#ifndef MDNS_NO_IPSEC
typedef enum _mDNSTunnelPolicyWhich
        {
        kmDNSTunnelPolicySetup,
        kmDNSTunnelPolicyTeardown,
        kmDNSTunnelPolicyGenerate
        } mDNSTunnelPolicyWhich;

// For kmDNSTunnelPolicySetup, you can setup IPv6-in-IPv6 tunnel or IPv6-in-IPv4 tunnel
// kmDNSNoTunnel is used for other Policy types
typedef enum _mDNSTunnelType
        {
        kmDNSNoTunnel,
        kmDNSIPv6IPv4Tunnel,
        kmDNSIPv6IPv6Tunnel
        } mDNSTunnelType;

static const uint8_t kWholeV6Mask = 128;
static const uint8_t kZeroV6Mask  = 0;

static int
doTunnelPolicy(mDNSTunnelPolicyWhich which, mDNSTunnelType type,
               v6addr_t loc_inner, uint8_t loc_bits,
               v4addr_t loc_outer, uint16_t loc_port, 
               v6addr_t rmt_inner, uint8_t rmt_bits,
               v4addr_t rmt_outer, uint16_t rmt_port,
                   v6addr_t loc_outer6, v6addr_t rmt_outer6);

static int
aliasTunnelAddress(v6addr_t address)
        {
        struct in6_aliasreq ifra_in6;
        int err = 0;
        int s = -1;

        if (0 > (s = socket(AF_INET6, SOCK_DGRAM, 0)))
                {
                helplog(ASL_LEVEL_ERR, "socket(AF_INET6, ...) failed: %s",
                    strerror(errno));
                err = kmDNSHelperDatagramSocketCreationFailed;
                goto fin;
                }
        memset(&ifra_in6, 0, sizeof(ifra_in6));
        strlcpy(ifra_in6.ifra_name, kTunnelAddressInterface,
            sizeof(ifra_in6.ifra_name));
        ifra_in6.ifra_lifetime.ia6t_vltime = ND6_INFINITE_LIFETIME;
        ifra_in6.ifra_lifetime.ia6t_pltime = ND6_INFINITE_LIFETIME;

        ifra_in6.ifra_addr.sin6_family = AF_INET6;
        ifra_in6.ifra_addr.sin6_len = sizeof(struct sockaddr_in6);
        memcpy(&(ifra_in6.ifra_addr.sin6_addr), address,
            sizeof(ifra_in6.ifra_addr.sin6_addr));

        ifra_in6.ifra_prefixmask.sin6_family = AF_INET6;
        ifra_in6.ifra_prefixmask.sin6_len = sizeof(struct sockaddr_in6);
        memset(&(ifra_in6.ifra_prefixmask.sin6_addr), 0xFF,
            sizeof(ifra_in6.ifra_prefixmask.sin6_addr));

        if (0 > ioctl(s, SIOCAIFADDR_IN6, &ifra_in6))
                {
                helplog(ASL_LEVEL_ERR,
                    "ioctl(..., SIOCAIFADDR_IN6, ...) failed: %s",
                    strerror(errno));
                err = kmDNSHelperInterfaceCreationFailed;
                goto fin;
                }

        v6addr_t zero = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0        };
        err = doTunnelPolicy(kmDNSTunnelPolicyGenerate, kmDNSNoTunnel,
            address, kWholeV6Mask, NULL, 0,
            zero, kZeroV6Mask, NULL, 0, NULL, NULL);

fin:
        if (0 <= s)
                close(s);
        return err;
        }

static int
unaliasTunnelAddress(v6addr_t address)
        {
        struct in6_ifreq ifr;
        int err = 0;
        int s = -1;

        if (0 > (s = socket(AF_INET6, SOCK_DGRAM, 0)))
                {
                helplog(ASL_LEVEL_ERR, "socket(AF_INET6, ...) failed: %s",
                    strerror(errno));
                err = kmDNSHelperDatagramSocketCreationFailed;
                goto fin;
                }
        memset(&ifr, 0, sizeof(ifr));
        strlcpy(ifr.ifr_name, kTunnelAddressInterface, sizeof(ifr.ifr_name));
        ifr.ifr_ifru.ifru_addr.sin6_family = AF_INET6;
        ifr.ifr_ifru.ifru_addr.sin6_len = sizeof(struct sockaddr_in6);
        memcpy(&(ifr.ifr_ifru.ifru_addr.sin6_addr), address,
            sizeof(ifr.ifr_ifru.ifru_addr.sin6_addr));

        if (0 > ioctl(s, SIOCDIFADDR_IN6, &ifr))
                {
                helplog(ASL_LEVEL_ERR,
                    "ioctl(..., SIOCDIFADDR_IN6, ...) failed: %s",
                    strerror(errno));
                err = kmDNSHelperInterfaceDeletionFailed;
                goto fin;
                }

        v6addr_t zero = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
        err = doTunnelPolicy(kmDNSTunnelPolicyTeardown, kmDNSNoTunnel,
            address, kWholeV6Mask, NULL, 0,
            zero, kZeroV6Mask, NULL, 0, NULL, NULL);

fin:
        if (0 <= s)
                close(s);
        return err;
        }
#endif /* ifndef MDNS_NO_IPSEC */

int
do_mDNSAutoTunnelInterfaceUpDown(__unused mach_port_t port, int updown,
    v6addr_t address, audit_token_t token)
        {
#ifndef MDNS_NO_IPSEC
        debug("entry");
        if (!authorized(&token)) goto fin;

        switch ((enum mDNSUpDown)updown)
                {
                case kmDNSUp:
                        aliasTunnelAddress(address);
                        break;
                case kmDNSDown:
                        unaliasTunnelAddress(address);
                        break;
                default:
                        goto fin;
                }
        debug("succeeded");

fin:
#else
        (void)port; (void)updown; (void)address; (void)token;
#endif
        update_idle_timer();
        return KERN_SUCCESS;
        }

#ifndef MDNS_NO_IPSEC

static const char g_racoon_config_dir[] = "/var/run/racoon/";
static const char g_racoon_config_dir_old[] = "/etc/racoon/remote/";

CF_EXPORT CFDictionaryRef _CFCopySystemVersionDictionary(void);
CF_EXPORT const CFStringRef _kCFSystemVersionBuildVersionKey;

// Major version  6 is 10.2.x (Jaguar)
// Major version  7 is 10.3.x (Panther)
// Major version  8 is 10.4.x (Tiger)
// Major version  9 is 10.5.x (Leopard)
// Major version 10 is 10.6.x (SnowLeopard)
static int MacOSXSystemBuildNumber(char* letter_out, int* minor_out)
        {
        int major = 0, minor = 0;
        char letter = 0, buildver[256]="<Unknown>";
        CFDictionaryRef vers = _CFCopySystemVersionDictionary();
        if (vers)
                {
                CFStringRef cfbuildver = CFDictionaryGetValue(vers, _kCFSystemVersionBuildVersionKey);
                if (cfbuildver) CFStringGetCString(cfbuildver, buildver, sizeof(buildver), kCFStringEncodingUTF8);
                sscanf(buildver, "%d%c%d", &major, &letter, &minor);
                CFRelease(vers);
                }
        else
                helplog(ASL_LEVEL_NOTICE, "_CFCopySystemVersionDictionary failed");
        
        if (!major) { major=10; letter = 'A'; minor = 190; helplog(ASL_LEVEL_NOTICE, "Note: No Major Build Version number found; assuming 10A190"); }
        if (letter_out) *letter_out = letter;
        if (minor_out) *minor_out = minor;
        return(major);
        }
        
static int UseOldRacoon()
        {
        static int g_oldRacoon = -1;

        if (g_oldRacoon == -1)
                {
                char letter = 0;
                int minor = 0;
                g_oldRacoon = (MacOSXSystemBuildNumber(&letter, &minor) < 10);
                debug("%s", g_oldRacoon?"old":"new");
                }

        return g_oldRacoon;
        }
        
static int RacoonSignal()
        {
        return UseOldRacoon() ? SIGHUP : SIGUSR1;
        }
        
static const char* GetRacoonConfigDir()
        {
        return UseOldRacoon() ? g_racoon_config_dir_old : g_racoon_config_dir;
        }
        
static const char* GetOldRacoonConfigDir()
        {
        return UseOldRacoon() ? NULL : g_racoon_config_dir_old;
        }
        
static const char racoon_config_file[] = "anonymous.conf";
static const char racoon_config_file_orig[] = "anonymous.conf.orig";

static const char configHeader[] = "# BackToMyMac\n";

static int IsFamiliarRacoonConfiguration(const char* racoon_config_path)
        {
        int fd = open(racoon_config_path, O_RDONLY);
        debug("entry %s", racoon_config_path);
        if (0 > fd)
                {
                helplog(ASL_LEVEL_NOTICE, "open \"%s\" failed: %s", racoon_config_path, strerror(errno));
                return 0;
                }
        else
                {
                char header[sizeof(configHeader)] = {0};
                ssize_t bytesRead = read(fd, header, sizeof(header)-1);
                close(fd);
                if (bytesRead != sizeof(header)-1) return 0;
                return (0 == memcmp(header, configHeader, sizeof(header)-1));
                }
        }

static void
revertAnonymousRacoonConfiguration(const char* dir)
        {
        if (!dir) return;
        
        debug("entry %s", dir);

        char racoon_config_path[64];
        strlcpy(racoon_config_path, dir, sizeof(racoon_config_path));
        strlcat(racoon_config_path, racoon_config_file, sizeof(racoon_config_path));

        struct stat s;
        int ret = stat(racoon_config_path, &s);
        debug("stat(%s): %d errno=%d", racoon_config_path, ret, errno);
        if (ret == 0)
                {
                if (IsFamiliarRacoonConfiguration(racoon_config_path))
                        {
                        helplog(ASL_LEVEL_INFO, "\"%s\" looks familiar, unlinking", racoon_config_path);
                        unlink(racoon_config_path);
                        }
                else
                        {
                        helplog(ASL_LEVEL_NOTICE, "\"%s\" does not look familiar, leaving in place", racoon_config_path);
                        return;
                        }
                }
        else if (errno != ENOENT)
                {
                helplog(ASL_LEVEL_NOTICE, "stat failed for \"%s\", leaving in place: %s", racoon_config_path, strerror(errno));
                return;
                }

        char racoon_config_path_orig[64];
        strlcpy(racoon_config_path_orig, dir, sizeof(racoon_config_path_orig));
        strlcat(racoon_config_path_orig, racoon_config_file_orig, sizeof(racoon_config_path_orig));

        ret = stat(racoon_config_path_orig, &s);
        debug("stat(%s): %d errno=%d", racoon_config_path_orig, ret, errno);
        if (ret == 0)
                {
                if (0 > rename(racoon_config_path_orig, racoon_config_path))
                        helplog(ASL_LEVEL_NOTICE, "rename \"%s\" \"%s\" failed: %s", racoon_config_path_orig, racoon_config_path, strerror(errno));
                else
                        debug("reverted \"%s\" to \"%s\"", racoon_config_path_orig, racoon_config_path);
                }
        else if (errno != ENOENT)
                {
                helplog(ASL_LEVEL_NOTICE, "stat failed for \"%s\", leaving in place: %s", racoon_config_path_orig, strerror(errno));
                return;
                }
        }

static void
moveAsideAnonymousRacoonConfiguration(const char* dir)
        {
        if (!dir) return;
        
        debug("entry %s", dir);
        
        char racoon_config_path[64];
        strlcpy(racoon_config_path, dir, sizeof(racoon_config_path));
        strlcat(racoon_config_path, racoon_config_file, sizeof(racoon_config_path));
        
        struct stat s;
        int ret = stat(racoon_config_path, &s);
        if (ret == 0)
                {
                if (IsFamiliarRacoonConfiguration(racoon_config_path))
                        {
                        helplog(ASL_LEVEL_INFO, "\"%s\" looks familiar, unlinking", racoon_config_path);
                        unlink(racoon_config_path);
                        }
                else
                        {
                        char racoon_config_path_orig[64];
                        strlcpy(racoon_config_path_orig, dir, sizeof(racoon_config_path_orig));
                        strlcat(racoon_config_path_orig, racoon_config_file_orig, sizeof(racoon_config_path_orig));
                        if (0 > rename(racoon_config_path, racoon_config_path_orig)) // If we didn't write it, move it to the side so it can be reverted later
                                helplog(ASL_LEVEL_NOTICE, "rename \"%s\" to \"%s\" failed: %s", racoon_config_path, racoon_config_path_orig, strerror(errno));
                        else
                                debug("successfully renamed \"%s\" to \"%s\"", racoon_config_path, racoon_config_path_orig);
                        }
                }
        else if (errno != ENOENT)
                {
                helplog(ASL_LEVEL_NOTICE, "stat failed for \"%s\", leaving in place: %s", racoon_config_path, strerror(errno));
                return;
                }
        }

static int
ensureExistenceOfRacoonConfigDir(const char* const racoon_config_dir)
        {
        struct stat s;
        int ret = stat(racoon_config_dir, &s);
        if (ret != 0)
                {
                if (errno != ENOENT)
                        {
                        helplog(ASL_LEVEL_ERR, "stat of \"%s\" failed (%d): %s",
                                racoon_config_dir, ret, strerror(errno));
                        return -1;
                        }
                else
                        {
                        ret = mkdir(racoon_config_dir, S_IRWXU | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH);
                        if (ret != 0)
                                {
                                helplog(ASL_LEVEL_ERR, "mkdir \"%s\" failed: %s",
                                        racoon_config_dir, strerror(errno));
                                return -1;
                                }
                        else
                                helplog(ASL_LEVEL_INFO, "created directory \"%s\"", racoon_config_dir);
                        }
                }
        else if (!(s.st_mode & S_IFDIR))
                {
                helplog(ASL_LEVEL_ERR, "\"%s\" is not a directory!",
                        racoon_config_dir);
                return -1;
                }
        
        return 0;
        }

static int
createAnonymousRacoonConfiguration(const char *fqdn)
        {
        static const char config1[] =
          "remote anonymous {\n"
          "  exchange_mode aggressive;\n"
          "  doi ipsec_doi;\n"
          "  situation identity_only;\n"
          "  verify_identifier off;\n"
          "  generate_policy on;\n"
          "  shared_secret keychain_by_id \"dns:";
        static const char config2[] =
          "\";\n"
          "  nonce_size 16;\n"
          "  lifetime time 15 min;\n"
          "  initial_contact on;\n"
          "  support_proxy on;\n"
          "  nat_traversal force;\n"
          "  proposal_check claim;\n"
          "  proposal {\n"
          "    encryption_algorithm aes;\n"
          "    hash_algorithm sha1;\n"
          "    authentication_method pre_shared_key;\n"
          "    dh_group 2;\n"
          "    lifetime time 15 min;\n"
          "  }\n"
          "}\n\n"
          "sainfo anonymous { \n"
          "  pfs_group 2;\n"
          "  lifetime time 10 min;\n"
          "  encryption_algorithm aes;\n"
          "  authentication_algorithm hmac_sha1;\n"
          "  compression_algorithm deflate;\n"
          "}\n";
        char tmp_config_path[64];
        char racoon_config_path[64];
        const char* const racoon_config_dir = GetRacoonConfigDir();
        const char* const racoon_config_dir_old = GetOldRacoonConfigDir();
        int fd = -1;
        
        debug("entry");
        
        if (0 > ensureExistenceOfRacoonConfigDir(racoon_config_dir))
                return -1;

        strlcpy(tmp_config_path, racoon_config_dir, sizeof(tmp_config_path));
        strlcat(tmp_config_path, "tmp.XXXXXX", sizeof(tmp_config_path));

        fd = mkstemp(tmp_config_path);

        if (0 > fd)
                {
                helplog(ASL_LEVEL_ERR, "mkstemp \"%s\" failed: %s",
                    tmp_config_path, strerror(errno));
                return -1;
                }
        write(fd, configHeader, sizeof(configHeader)-1);
        write(fd, config1, sizeof(config1)-1);
        write(fd, fqdn, strlen(fqdn));
        write(fd, config2, sizeof(config2)-1);
        close(fd);

        strlcpy(racoon_config_path, racoon_config_dir, sizeof(racoon_config_path));
        strlcat(racoon_config_path, racoon_config_file, sizeof(racoon_config_path));

        moveAsideAnonymousRacoonConfiguration(racoon_config_dir_old);
        moveAsideAnonymousRacoonConfiguration(racoon_config_dir);

        if (0 > rename(tmp_config_path, racoon_config_path))
                {
                unlink(tmp_config_path);
                helplog(ASL_LEVEL_ERR, "rename \"%s\" \"%s\" failed: %s",
                    tmp_config_path, racoon_config_path, strerror(errno));
                revertAnonymousRacoonConfiguration(racoon_config_dir_old);
                revertAnonymousRacoonConfiguration(racoon_config_dir);
                return -1;
                }

        debug("successfully renamed \"%s\" \"%s\"", tmp_config_path, racoon_config_path);
        return 0;
        }

static int
notifyRacoon(void)
        {
        debug("entry");
        static const char racoon_pid_path[] = "/var/run/racoon.pid";
        char buf[] = "18446744073709551615"; /* largest 64-bit integer */
        char *p = NULL;
        ssize_t n = 0;
        unsigned long m = 0;
        int fd = open(racoon_pid_path, O_RDONLY);

        if (0 > fd)
                {
                debug("open \"%s\" failed, and that's OK: %s", racoon_pid_path,
                    strerror(errno));
                return kmDNSHelperRacoonNotificationFailed;
                }
        n = read(fd, buf, sizeof(buf)-1);
        close(fd);
        if (1 > n)
                {
                debug("read of \"%s\" failed: %s", racoon_pid_path,
                    n == 0 ? "empty file" : strerror(errno));
                return kmDNSHelperRacoonNotificationFailed;
                }
        buf[n] = '\0';
        m = strtoul(buf, &p, 10);
        if (*p != '\0' && !isspace(*p))
                {
                debug("invalid PID \"%s\" (around '%c')", buf, *p);
                return kmDNSHelperRacoonNotificationFailed;
                }
        if (2 > m)
                {
                debug("refusing to kill PID %lu", m);
                return kmDNSHelperRacoonNotificationFailed;
                }
        if (0 != kill(m, RacoonSignal()))
                {
                debug("Could not signal racoon (%lu): %s", m, strerror(errno));
                return kmDNSHelperRacoonNotificationFailed;
                }
        debug("Sent racoon (%lu) signal %d", m, RacoonSignal());
        return 0;
        }

static void
closefds(int from)
        {
        int fd = 0;
        struct dirent entry, *entryp = NULL;
        DIR *dirp = opendir("/dev/fd");

        if (dirp == NULL)
                {
                /* fall back to the erroneous getdtablesize method */
                for (fd = from; fd < getdtablesize(); ++fd)
                        close(fd);
                return;
                }
        while (0 == readdir_r(dirp, &entry, &entryp) && NULL != entryp)
                {
                fd = atoi(entryp->d_name);
                if (fd >= from && fd != dirfd(dirp))
                        close(fd);
                }
        closedir(dirp);
        }

static int
startRacoonOld(void)
        {
        debug("entry");
        char * const racoon_args[] = { "/usr/sbin/racoon", "-e", NULL   };
        ssize_t n = 0;
        pid_t pid = 0;
        int status = 0;

        if (0 == (pid = fork()))
                {
                closefds(0);
                execve(racoon_args[0], racoon_args, NULL);
                helplog(ASL_LEVEL_ERR, "execve of \"%s\" failed: %s",
                    racoon_args[0], strerror(errno));
                exit(2);
                }
        helplog(ASL_LEVEL_NOTICE, "racoon (pid=%lu) started",
            (unsigned long)pid);
        n = waitpid(pid, &status, 0);
        if (-1 == n)
                {
                helplog(ASL_LEVEL_ERR, "Unexpected waitpid failure: %s",
                    strerror(errno));
                return kmDNSHelperRacoonStartFailed;
                }
        else if (pid != n)
                {
                helplog(ASL_LEVEL_ERR, "Unexpected waitpid return value %d",
                    (int)n);
                return kmDNSHelperRacoonStartFailed;
                }
        else if (WIFSIGNALED(status))
                {
                helplog(ASL_LEVEL_ERR,
                    "racoon (pid=%lu) terminated due to signal %d",
                    (unsigned long)pid, WTERMSIG(status));
                return kmDNSHelperRacoonStartFailed;
                }
        else if (WIFSTOPPED(status))
                {
                helplog(ASL_LEVEL_ERR,
                    "racoon (pid=%lu) has stopped due to signal %d",
                    (unsigned long)pid, WSTOPSIG(status));
                return kmDNSHelperRacoonStartFailed;
                }
        else if (0 != WEXITSTATUS(status))
                {
                helplog(ASL_LEVEL_ERR,
                    "racoon (pid=%lu) exited with status %d",
                    (unsigned long)pid, WEXITSTATUS(status));
                return kmDNSHelperRacoonStartFailed;
                }
        debug("racoon (pid=%lu) daemonized normally", (unsigned long)pid);
        return 0;
        }

// constant and structure for the racoon control socket
#define VPNCTL_CMD_PING 0x0004
typedef struct vpnctl_hdr_struct
        {
        u_int16_t msg_type;
        u_int16_t flags;
        u_int32_t cookie;
        u_int32_t reserved;
        u_int16_t result;
        u_int16_t len;
        } vpnctl_hdr;

static int
startRacoon(void)
        {
        debug("entry");
        int fd = socket(PF_UNIX, SOCK_STREAM, 0);
        if (0 > fd)
                {
                helplog(ASL_LEVEL_ERR, "Could not create endpoint for racoon control socket: %d %s",
                        errno, strerror(errno));
                return kmDNSHelperRacoonStartFailed;
                }

        struct sockaddr_un saddr;
        memset(&saddr, 0, sizeof(saddr));
        saddr.sun_family = AF_UNIX;
        saddr.sun_len = sizeof(saddr);
        static const char racoon_control_sock_path[] = "/var/run/vpncontrol.sock";
        strcpy(saddr.sun_path, racoon_control_sock_path);
        int result = connect(fd, (struct sockaddr*) &saddr, saddr.sun_len);
        if (0 > result)
                {
                helplog(ASL_LEVEL_ERR, "Could not connect racoon control socket %s: %d %s",
                        racoon_control_sock_path, errno, strerror(errno));
                return kmDNSHelperRacoonStartFailed;
                }
        
        u_int32_t btmm_cookie = 0x4d4d5442;
        vpnctl_hdr h = { VPNCTL_CMD_PING, 0, btmm_cookie, 0, 0, 0 };
        size_t bytes = 0;
        ssize_t ret = 0;
        
        while (bytes < sizeof(vpnctl_hdr))
                {
                ret = write(fd, ((unsigned char*)&h)+bytes, sizeof(vpnctl_hdr) - bytes);
                if (ret == -1)
                        {
                        helplog(ASL_LEVEL_ERR, "Could not write to racoon control socket: %d %s",
                                errno, strerror(errno));
                        return kmDNSHelperRacoonStartFailed;
                        }
                bytes += ret;
                }
        
        int nfds = fd + 1;
        fd_set fds;
        int counter = 0;
        struct timeval tv;
        bytes = 0;
        h.cookie = 0;
        
        for (counter = 0; counter < 100; counter++)
                {
                FD_ZERO(&fds);
                FD_SET(fd, &fds);
                tv = (struct timeval){ 0, 10000 }; // 10 milliseconds * 100 iterations = 1 second max wait time

                result = select(nfds, &fds, (fd_set*)NULL, (fd_set*)NULL, &tv);
                if (result > 0)
                        {
                        if (FD_ISSET(fd, &fds))
                                {
                                ret = read(fd, ((unsigned char*)&h)+bytes, sizeof(vpnctl_hdr) - bytes);
                                
                                if (ret == -1)
                                        {
                                        helplog(ASL_LEVEL_ERR, "Could not read from racoon control socket: %d %s",
                                                strerror(errno));
                                        break;
                                        }
                                bytes += ret;
                                if (bytes >= sizeof(vpnctl_hdr)) break;
                                }
                        else
                                {
                                debug("select returned but fd_isset not on expected fd\n");
                                }
                        }
                else if (result < 0)
                        {
                        debug("select returned %d errno %d %s\n", result, errno, strerror(errno));
                        if (errno != EINTR) break;
                        }
                }
        
        close(fd);
        
        if (bytes < sizeof(vpnctl_hdr) || h.cookie != btmm_cookie) return kmDNSHelperRacoonStartFailed;

        debug("racoon started");
        return 0;
        }

static int
kickRacoon(void)
        {
        if ( 0 == notifyRacoon() )
                return 0;
        return UseOldRacoon() ? startRacoonOld() : startRacoon();
        }

#endif /* ndef MDNS_NO_IPSEC */

int
do_mDNSConfigureServer(__unused mach_port_t port, int updown, const char *fqdn, audit_token_t token)
        {
#ifndef MDNS_NO_IPSEC
        debug("entry");
        if (!authorized(&token)) goto fin;

        switch ((enum mDNSUpDown)updown)
                {
                case kmDNSUp:
                        if (0 != createAnonymousRacoonConfiguration(fqdn)) goto fin;
                        break;
                case kmDNSDown:
                        revertAnonymousRacoonConfiguration(GetOldRacoonConfigDir());
                        revertAnonymousRacoonConfiguration(GetRacoonConfigDir());
                        break;
                default:
                        goto fin;
                }

        if (0 != kickRacoon())
                goto fin;
        debug("succeeded");

fin:
#else
        (void)port; (void)updown; (void)fqdn; (void)token;
#endif
        update_idle_timer();
        return KERN_SUCCESS;
        }

#ifndef MDNS_NO_IPSEC

static unsigned int routeSeq = 1;

static int
setupTunnelRoute(v6addr_t local, v6addr_t remote)
        {
        struct
                {
                struct rt_msghdr    hdr;
                struct sockaddr_in6 dst;
                struct sockaddr_in6 gtwy;
                } msg;
        int err = 0;
        int s = -1;

        if (0 > (s = socket(PF_ROUTE, SOCK_RAW, AF_INET)))
                {
                helplog(ASL_LEVEL_ERR, "socket(PF_ROUTE, ...) failed: %s",
                    strerror(errno));
                err = kmDNSHelperRoutingSocketCreationFailed;
                goto fin;
                }
        memset(&msg, 0, sizeof(msg));
        msg.hdr.rtm_msglen = sizeof(msg);
        msg.hdr.rtm_type = RTM_ADD;
        /* The following flags are set by `route add -inet6 -host ...` */
        msg.hdr.rtm_flags = RTF_UP | RTF_GATEWAY | RTF_HOST | RTF_STATIC;
        msg.hdr.rtm_version = RTM_VERSION;
        msg.hdr.rtm_seq = routeSeq++;
        msg.hdr.rtm_addrs = RTA_DST | RTA_GATEWAY;
        msg.hdr.rtm_inits = RTV_MTU;
        msg.hdr.rtm_rmx.rmx_mtu = 1280;

        msg.dst.sin6_len = sizeof(msg.dst);
        msg.dst.sin6_family = AF_INET6;
        memcpy(&msg.dst.sin6_addr, remote, sizeof(msg.dst.sin6_addr));

        msg.gtwy.sin6_len = sizeof(msg.gtwy);
        msg.gtwy.sin6_family = AF_INET6;
        memcpy(&msg.gtwy.sin6_addr, local, sizeof(msg.gtwy.sin6_addr));

        /* send message, ignore error when route already exists */
        if (0 > write(s, &msg, msg.hdr.rtm_msglen))
                {
                int errno_ = errno;

                debug("write to routing socket failed: %s", strerror(errno_));
                if (EEXIST != errno_)
                        {
                        err = kmDNSHelperRouteAdditionFailed;
                        goto fin;
                        }
                }

fin:
        if (0 <= s)
                close(s);
        return err;
        }

static int
teardownTunnelRoute(v6addr_t remote)
        {
        struct
                {
                struct rt_msghdr    hdr;
                struct sockaddr_in6 dst;
                } msg;
        int err = 0;
        int s = -1;

        if (0 > (s = socket(PF_ROUTE, SOCK_RAW, AF_INET)))
                {
                helplog(ASL_LEVEL_ERR, "socket(PF_ROUTE, ...) failed: %s",
                    strerror(errno));
                err = kmDNSHelperRoutingSocketCreationFailed;
                goto fin;
                }
        memset(&msg, 0, sizeof(msg));

        msg.hdr.rtm_msglen = sizeof(msg);
        msg.hdr.rtm_type = RTM_DELETE;
        msg.hdr.rtm_version = RTM_VERSION;
        msg.hdr.rtm_seq = routeSeq++;
        msg.hdr.rtm_addrs = RTA_DST;

        msg.dst.sin6_len = sizeof(msg.dst);
        msg.dst.sin6_family = AF_INET6;
        memcpy(&msg.dst.sin6_addr, remote, sizeof(msg.dst.sin6_addr));
        if (0 > write(s, &msg, msg.hdr.rtm_msglen))
                {
                int errno_ = errno;

                debug("write to routing socket failed: %s", strerror(errno_));
                if (ESRCH != errno_)
                        {
                        err = kmDNSHelperRouteDeletionFailed;
                        goto fin;
                        }
                }

fin:
        if (0 <= s)
                close(s);
        return err;
        }

static int
v4addr_to_string(v4addr_t addr, char *buf, size_t buflen)
        {
        if (NULL == inet_ntop(AF_INET, addr, buf, buflen))
                {
                helplog(ASL_LEVEL_ERR, "inet_ntop failed: %s",
                    strerror(errno));
                return kmDNSHelperInvalidNetworkAddress;
                }
        else
                return 0;
        }

static int
v6addr_to_string(v6addr_t addr, char *buf, size_t buflen)
        {
        if (NULL == inet_ntop(AF_INET6, addr, buf, buflen))
                {
                helplog(ASL_LEVEL_ERR, "inet_ntop failed: %s",
                    strerror(errno));
                return kmDNSHelperInvalidNetworkAddress;
                }
        else
                return 0;
        }

/* Caller owns object returned in `policy' */
static int
generateTunnelPolicy(mDNSTunnelPolicyWhich which, mDNSTunnelType type, int in,
                     v4addr_t src, uint16_t src_port,
                     v4addr_t dst, uint16_t dst_port,
                         v6addr_t src6, v6addr_t dst6,
                     ipsec_policy_t *policy, size_t *len)
        {
        char srcs[INET_ADDRSTRLEN], dsts[INET_ADDRSTRLEN];
        char srcs6[INET6_ADDRSTRLEN], dsts6[INET6_ADDRSTRLEN];
        char buf[512];
        char *inOut = in ? "in" : "out";
        ssize_t n = 0;
        int err = 0;

        *policy = NULL;
        *len = 0;

        switch (which)
        {
        case kmDNSTunnelPolicySetup:
                if (type == kmDNSIPv6IPv4Tunnel)
                        {
                        if (0 != (err = v4addr_to_string(src, srcs, sizeof(srcs))))
                                goto fin;
                        if (0 != (err = v4addr_to_string(dst, dsts, sizeof(dsts))))
                                goto fin;
                        n = snprintf(buf, sizeof(buf),
                        "%s ipsec esp/tunnel/%s[%u]-%s[%u]/require",
                        inOut, srcs, src_port, dsts, dst_port);
                        }
                else if (type == kmDNSIPv6IPv6Tunnel)
                        {
                        if (0 != (err = v6addr_to_string(src6, srcs6, sizeof(srcs6))))
                                goto fin;
                        if (0 != (err = v6addr_to_string(dst6, dsts6, sizeof(dsts6))))
                                goto fin;
                        n = snprintf(buf, sizeof(buf),
                        "%s ipsec esp/tunnel/%s-%s/require",
                        inOut, srcs6, dsts6);
                        }
                break;
        case kmDNSTunnelPolicyTeardown:
                n = strlcpy(buf, inOut, sizeof(buf));
                break;
        case kmDNSTunnelPolicyGenerate:
                n = snprintf(buf, sizeof(buf), "%s generate", inOut);
                break;
        default:
                err = kmDNSHelperIPsecPolicyCreationFailed;
                goto fin;
                }

        if (n >= (int)sizeof(buf))
                {
                err = kmDNSHelperResultTooLarge;
                goto fin;
                }

        debug("policy=\"%s\"", buf);
        if (NULL == (*policy = (ipsec_policy_t)ipsec_set_policy(buf, n)))
                {
                helplog(ASL_LEVEL_ERR,
                    "Could not create IPsec policy from \"%s\"", buf);
                err = kmDNSHelperIPsecPolicyCreationFailed;
                goto fin;
                }
        *len = ((ipsec_policy_t)(*policy))->sadb_x_policy_len * 8;

fin:
        return err;
        }

static int
sendPolicy(int s, int setup,
           struct sockaddr *src, uint8_t src_bits,
           struct sockaddr *dst, uint8_t dst_bits,
           ipsec_policy_t policy, size_t len)
        {
        static unsigned int policySeq = 0;
        int err = 0;

        debug("entry, setup=%d", setup);
        if (setup)
                err = pfkey_send_spdadd(s, src, src_bits, dst, dst_bits, -1,
                    (char *)policy, len, policySeq++);
        else
                err = pfkey_send_spddelete(s, src, src_bits, dst, dst_bits, -1,
                    (char *)policy, len, policySeq++);
        if (0 > err)
                {
                helplog(ASL_LEVEL_ERR, "Could not set IPsec policy: %s",
                    ipsec_strerror());
                err = kmDNSHelperIPsecPolicySetFailed;
                goto fin;
                }
        else
                err = 0;
        debug("succeeded");

fin:
        return err;
        }

static int
removeSA(int s, struct sockaddr *src, struct sockaddr *dst)
        {
        int err = 0;

        debug("entry");
        err = pfkey_send_delete_all(s, SADB_SATYPE_ESP, IPSEC_MODE_ANY, src, dst);
        if (0 > err)
                {
                helplog(ASL_LEVEL_ERR, "Could not remove IPsec SA: %s", ipsec_strerror());
                err = kmDNSHelperIPsecRemoveSAFailed;
                goto fin;
                }
        err = pfkey_send_delete_all(s, SADB_SATYPE_ESP, IPSEC_MODE_ANY, dst, src);
        if (0 > err)
                {
                helplog(ASL_LEVEL_ERR, "Could not remove IPsec SA: %s", ipsec_strerror());
                err = kmDNSHelperIPsecRemoveSAFailed;
                goto fin;
                }
        else
          err = 0;

        debug("succeeded");

fin:
        return err;
        }

static int
doTunnelPolicy(mDNSTunnelPolicyWhich which, mDNSTunnelType type,
               v6addr_t loc_inner, uint8_t loc_bits,
               v4addr_t loc_outer, uint16_t loc_port, 
               v6addr_t rmt_inner, uint8_t rmt_bits,
               v4addr_t rmt_outer, uint16_t rmt_port,
                   v6addr_t loc_outer6, v6addr_t rmt_outer6)
        {
        struct sockaddr_in6 sin6_loc;
        struct sockaddr_in6 sin6_rmt;
        ipsec_policy_t policy = NULL;
        size_t len = 0;
        int s = -1;
        int err = 0;

        debug("entry");
        if (0 > (s = pfkey_open()))
                {
                helplog(ASL_LEVEL_ERR,
                    "Could not create IPsec policy socket: %s",
                    ipsec_strerror());
                err = kmDNSHelperIPsecPolicySocketCreationFailed;
                goto fin;
                }

        memset(&sin6_loc, 0, sizeof(sin6_loc));
        sin6_loc.sin6_len = sizeof(sin6_loc);
        sin6_loc.sin6_family = AF_INET6;
        sin6_loc.sin6_port = htons(0);
        memcpy(&sin6_loc.sin6_addr, loc_inner, sizeof(sin6_loc.sin6_addr));

        memset(&sin6_rmt, 0, sizeof(sin6_rmt));
        sin6_rmt.sin6_len = sizeof(sin6_rmt);
        sin6_rmt.sin6_family = AF_INET6;
        sin6_rmt.sin6_port = htons(0);
        memcpy(&sin6_rmt.sin6_addr, rmt_inner, sizeof(sin6_rmt.sin6_addr));

        int setup = which != kmDNSTunnelPolicyTeardown;

        if (0 != (err = generateTunnelPolicy(which, type, 1,
            rmt_outer, rmt_port,
            loc_outer, loc_port,
                rmt_outer6, loc_outer6,
            &policy, &len)))
                goto fin;
        if (0 != (err = sendPolicy(s, setup,
            (struct sockaddr *)&sin6_rmt, rmt_bits,
            (struct sockaddr *)&sin6_loc, loc_bits,
            policy, len)))
                goto fin;
        if (NULL != policy)
                {
                free(policy);
                policy = NULL;
                }
        if (0 != (err = generateTunnelPolicy(which, type, 0,
            loc_outer, loc_port,
            rmt_outer, rmt_port,
                loc_outer6, rmt_outer6,
            &policy, &len)))
                goto fin;
        if (0 != (err = sendPolicy(s, setup,
            (struct sockaddr *)&sin6_loc, loc_bits,
            (struct sockaddr *)&sin6_rmt, rmt_bits,
            policy, len)))
                goto fin;

        if (which == kmDNSTunnelPolicyTeardown)
                {
                if (rmt_port)           // Outer tunnel is IPv4
                        {
                        if (loc_outer && rmt_outer)
                                {
                                struct sockaddr_in sin_loc;
                                struct sockaddr_in sin_rmt;
                                memset(&sin_loc, 0, sizeof(sin_loc));
                                sin_loc.sin_len = sizeof(sin_loc);
                                sin_loc.sin_family = AF_INET;
                                memcpy(&sin_loc.sin_addr, loc_outer, sizeof(sin_loc.sin_addr));
                
                                memset(&sin_rmt, 0, sizeof(sin_rmt));
                                sin_rmt.sin_len = sizeof(sin_rmt);
                                sin_rmt.sin_family = AF_INET;
                                memcpy(&sin_rmt.sin_addr, rmt_outer, sizeof(sin_rmt.sin_addr));
                                if (0 != (err = removeSA(s, (struct sockaddr *)&sin_loc, (struct sockaddr *)&sin_rmt)))
                                        goto fin;
                                }
                        }
                else
                        {
                        if (loc_outer6 && rmt_outer6)
                                {
                                struct sockaddr_in6 sin6_lo;
                                struct sockaddr_in6 sin6_rm;

                                memset(&sin6_lo, 0, sizeof(sin6_lo));
                                sin6_lo.sin6_len = sizeof(sin6_lo);
                                sin6_lo.sin6_family = AF_INET6;
                                memcpy(&sin6_lo.sin6_addr, loc_outer6, sizeof(sin6_lo.sin6_addr));
                
                                memset(&sin6_rm, 0, sizeof(sin6_rm));
                                sin6_rm.sin6_len = sizeof(sin6_rm);
                                sin6_rm.sin6_family = AF_INET6;
                                memcpy(&sin6_rm.sin6_addr, rmt_outer6, sizeof(sin6_rm.sin6_addr));
                                if (0 != (err = removeSA(s, (struct sockaddr *)&sin6_lo, (struct sockaddr *)&sin6_rm)))
                                        goto fin;
                                }
                        }
                }


        debug("succeeded");

fin:
        if (s >= 0)
                pfkey_close(s);
        if (NULL != policy)
                free(policy);
        return err;
        }

#endif /* ndef MDNS_NO_IPSEC */

int
do_mDNSAutoTunnelSetKeys(__unused mach_port_t port, int replacedelete,
    v6addr_t loc_inner, v6addr_t loc_outer6, uint16_t loc_port,
    v6addr_t rmt_inner, v6addr_t rmt_outer6, uint16_t rmt_port,
    const char *fqdn, int *err, audit_token_t token)
        {
#ifndef MDNS_NO_IPSEC
        static const char config[] =
          "%s"
          "remote %s [%u] {\n"
          "  disconnect_on_idle idle_timeout 600 idle_direction idle_outbound;\n"
          "  exchange_mode aggressive;\n"
          "  doi ipsec_doi;\n"
          "  situation identity_only;\n"
          "  verify_identifier off;\n"
          "  generate_policy on;\n"
          "  my_identifier user_fqdn \"dns:%s\";\n"
          "  shared_secret keychain \"dns:%s\";\n"
          "  nonce_size 16;\n"
          "  lifetime time 15 min;\n"
          "  initial_contact on;\n"
          "  support_proxy on;\n"
          "  nat_traversal force;\n"
          "  proposal_check claim;\n"
          "  proposal {\n"
          "    encryption_algorithm aes;\n"
          "    hash_algorithm sha1;\n"
          "    authentication_method pre_shared_key;\n"
          "    dh_group 2;\n"
          "    lifetime time 15 min;\n"
          "  }\n"
          "}\n\n"
          "sainfo address %s any address %s any {\n"
          "  pfs_group 2;\n"
          "  lifetime time 10 min;\n"
          "  encryption_algorithm aes;\n"
          "  authentication_algorithm hmac_sha1;\n"
          "  compression_algorithm deflate;\n"
          "}\n\n"
          "sainfo address %s any address %s any {\n"
          "  pfs_group 2;\n"
          "  lifetime time 10 min;\n"
          "  encryption_algorithm aes;\n"
          "  authentication_algorithm hmac_sha1;\n"
          "  compression_algorithm deflate;\n"
          "}\n";
        char path[PATH_MAX] = "";
        char li[INET6_ADDRSTRLEN], lo[INET_ADDRSTRLEN], lo6[INET6_ADDRSTRLEN],
            ri[INET6_ADDRSTRLEN], ro[INET_ADDRSTRLEN], ro6[INET6_ADDRSTRLEN];
        FILE *fp = NULL;
        int fd = -1;
        char tmp_path[PATH_MAX] = "";
        v4addr_t loc_outer, rmt_outer;

        debug("entry");
        *err = 0;
        if (!authorized(&token))
                {
                *err = kmDNSHelperNotAuthorized;
                goto fin;
                }
        switch ((enum mDNSAutoTunnelSetKeysReplaceDelete)replacedelete)
        {
        case kmDNSAutoTunnelSetKeysReplace:
        case kmDNSAutoTunnelSetKeysDelete:
                break;
        default:
                *err = kmDNSHelperInvalidTunnelSetKeysOperation;
                goto fin;
                }

        if (0 != (*err = v6addr_to_string(loc_inner, li, sizeof(li))))
                goto fin;
        if (0 != (*err = v6addr_to_string(rmt_inner, ri, sizeof(ri))))
                goto fin;

        debug("loc_inner=%s rmt_inner=%s", li, ri);
        if (!rmt_port)
                {
                loc_outer[0] = loc_outer[1] = loc_outer[2] = loc_outer[3] = 0;
                rmt_outer[0] = rmt_outer[1] = rmt_outer[2] = rmt_outer[3] = 0;

                if (0 != (*err = v6addr_to_string(loc_outer6, lo6, sizeof(lo6))))
                        goto fin;
                if (0 != (*err = v6addr_to_string(rmt_outer6, ro6, sizeof(ro6))))
                        goto fin;
                debug("IPv6 outer tunnel: loc_outer6=%s rmt_outer6=%s", lo6, ro6);
                if ((int)sizeof(path) <= snprintf(path, sizeof(path),
                "%s%s.conf", GetRacoonConfigDir(), ro6))
                        {
                        *err = kmDNSHelperResultTooLarge;
                        goto fin;
                        }
                }
        else
                {
                loc_outer[0] = loc_outer6[0];
                loc_outer[1] = loc_outer6[1];
                loc_outer[2] = loc_outer6[2];
                loc_outer[3] = loc_outer6[3];

                rmt_outer[0] = rmt_outer6[0];
                rmt_outer[1] = rmt_outer6[1];
                rmt_outer[2] = rmt_outer6[2];
                rmt_outer[3] = rmt_outer6[3];

                if (0 != (*err = v4addr_to_string(loc_outer, lo, sizeof(lo))))
                        goto fin;
                if (0 != (*err = v4addr_to_string(rmt_outer, ro, sizeof(ro))))
                        goto fin;
                debug("IPv4 outer tunnel: loc_outer=%s loc_port=%u rmt_outer=%s rmt_port=%u",
                lo, loc_port, ro, rmt_port);

                if ((int)sizeof(path) <= snprintf(path, sizeof(path),
                "%s%s.%u.conf", GetRacoonConfigDir(), ro,
                rmt_port))
                        {
                        *err = kmDNSHelperResultTooLarge;
                        goto fin;
                        }
                }



        if (kmDNSAutoTunnelSetKeysReplace == replacedelete)
                {
                if (0 > ensureExistenceOfRacoonConfigDir(GetRacoonConfigDir()))
                        {
                        *err = kmDNSHelperRacoonConfigCreationFailed;
                        goto fin;
                        }
                if ((int)sizeof(tmp_path) <=
                    snprintf(tmp_path, sizeof(tmp_path), "%s.XXXXXX", path))
                        {
                        *err = kmDNSHelperResultTooLarge;
                        goto fin;
                        }       
                if (0 > (fd = mkstemp(tmp_path)))
                        {
                        helplog(ASL_LEVEL_ERR, "mkstemp \"%s\" failed: %s",
                            tmp_path, strerror(errno));
                        *err = kmDNSHelperRacoonConfigCreationFailed;
                        goto fin;
                        }
                if (NULL == (fp = fdopen(fd, "w")))
                        {
                        helplog(ASL_LEVEL_ERR, "fdopen: %s",
                            strerror(errno));
                        *err = kmDNSHelperRacoonConfigCreationFailed;
                        goto fin;
                        }
                fd = -1;
                fprintf(fp, config, configHeader, (!rmt_port ? ro6 : ro), rmt_port, fqdn, fqdn, ri, li, li, ri);
                fclose(fp);
                fp = NULL;
                if (0 > rename(tmp_path, path))
                        {
                        helplog(ASL_LEVEL_ERR,
                            "rename \"%s\" \"%s\" failed: %s",
                            tmp_path, path, strerror(errno));
                        *err = kmDNSHelperRacoonConfigCreationFailed;
                        goto fin;
                        }
                }
        else
                {
                if (0 != unlink(path))
                        debug("unlink \"%s\" failed: %s", path,
                            strerror(errno));
                }

        if (0 != (*err = doTunnelPolicy(kmDNSTunnelPolicyTeardown, kmDNSNoTunnel,
            loc_inner, kWholeV6Mask, loc_outer, loc_port,
            rmt_inner, kWholeV6Mask, rmt_outer, rmt_port, loc_outer6, rmt_outer6)))
                goto fin;
        if (kmDNSAutoTunnelSetKeysReplace == replacedelete &&
            0 != (*err = doTunnelPolicy(kmDNSTunnelPolicySetup, (!rmt_port ? kmDNSIPv6IPv6Tunnel : kmDNSIPv6IPv4Tunnel),
                loc_inner, kWholeV6Mask, loc_outer, loc_port,
                rmt_inner, kWholeV6Mask, rmt_outer, rmt_port, loc_outer6, rmt_outer6)))
                goto fin;

        if (0 != (*err = teardownTunnelRoute(rmt_inner)))
                goto fin;
        if (kmDNSAutoTunnelSetKeysReplace == replacedelete &&
                0 != (*err = setupTunnelRoute(loc_inner, rmt_inner)))
                goto fin;

        if (kmDNSAutoTunnelSetKeysReplace == replacedelete &&
                0 != (*err = kickRacoon()))
                goto fin;

        debug("succeeded");

fin:
        if (NULL != fp)
                fclose(fp);
        if (0 <= fd)
                close(fd);
        unlink(tmp_path);
#else
        (void)replacedelete; (void)loc_inner; (void)loc_outer6; (void)loc_port; (void)rmt_inner;
        (void)rmt_outer6; (void)rmt_port; (void)fqdn; (void)token;
        
        *err = kmDNSHelperIPsecDisabled;
#endif /* MDNS_NO_IPSEC */
        update_idle_timer();
        return KERN_SUCCESS;
        }