/*
 * Copyright (c) 2007-2012 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 <mach/mach.h>
#include <mach/mach_error.h>
#include <mach/vm_map.h>
#include <servers/bootstrap.h>
#include <IOKit/IOReturn.h>
#include <CoreFoundation/CoreFoundation.h>
#include "mDNSDebug.h"
#include "helper.h"
#include "helpermsg.h"

#define ERROR(x, y) y,
static const char *errorstring[] =
{
    #include "helper-error.h"
    NULL
};
#undef ERROR

static mach_port_t getHelperPort(int retry)
{
    static mach_port_t port = MACH_PORT_NULL;
    if (retry) port = MACH_PORT_NULL;
    if (port == MACH_PORT_NULL && BOOTSTRAP_SUCCESS != bootstrap_look_up(bootstrap_port, kmDNSHelperServiceName, &port))
        LogMsg("%s: cannot contact helper", __func__);
    return port;
}

const char *mDNSHelperError(int err)
{
    static const char *p = "<unknown error>";
    if (mDNSHelperErrorBase < err && mDNSHelperErrorEnd > err)
        p = errorstring[err - mDNSHelperErrorBase - 1];
    return p;
}

/* Ugly but handy. */
// We don't bother reporting kIOReturnNotReady because that error code occurs in "normal" operation
// and doesn't indicate anything unexpected that needs to be investigated

#define MACHRETRYLOOP_BEGIN(kr, retry, err, fin)                                            \
    for (;;)                                                                                \
    {
#define MACHRETRYLOOP_END(kr, retry, err, fin)                                              \
    if (KERN_SUCCESS == (kr)) break;                                                                                             \
    else if (MACH_SEND_INVALID_DEST == (kr) && 0 == (retry)++) continue;                                                                                             \
    else                                                                                \
    {                                                                               \
        (err) = kmDNSHelperCommunicationFailed;                                         \
        LogMsg("%s: Mach communication failed: %d %X %s", __func__, kr, kr, mach_error_string(kr)); \
        goto fin;                                                                       \
    }                                                                               \
    }                                                                                   \
    if (0 != (err) && kIOReturnNotReady != (err))                                           \
    { LogMsg("%s: %d 0x%X (%s)", __func__, (err), (err), mDNSHelperError(err)); goto fin; }

void mDNSPreferencesSetName(int key, domainlabel *old, domainlabel *new)
{
    kern_return_t kr = KERN_FAILURE;
    int retry = 0;
    int err = 0;
    char oldname[MAX_DOMAIN_LABEL+1] = {0};
    char newname[MAX_DOMAIN_LABEL+1] = {0};
    ConvertDomainLabelToCString_unescaped(old, oldname);
    if (new) ConvertDomainLabelToCString_unescaped(new, newname);

    MACHRETRYLOOP_BEGIN(kr, retry, err, fin);
    kr = proxy_mDNSPreferencesSetName(getHelperPort(retry), key, oldname, newname);
    MACHRETRYLOOP_END(kr, retry, err, fin);

fin:
    (void)err;
}

void mDNSDynamicStoreSetConfig(int key, const char *subkey, CFPropertyListRef value)
{
    CFWriteStreamRef stream = NULL;
    CFDataRef bytes = NULL;
    kern_return_t kr = KERN_FAILURE;
    int retry = 0;
    int err = 0;

    if (NULL == (stream = CFWriteStreamCreateWithAllocatedBuffers(NULL, NULL)))
    {
        err = kmDNSHelperCreationFailed;
        LogMsg("%s: CFWriteStreamCreateWithAllocatedBuffers failed", __func__);
        goto fin;
    }
    CFWriteStreamOpen(stream);
    if (0 == CFPropertyListWriteToStream(value, stream, kCFPropertyListBinaryFormat_v1_0, NULL))
    {
        err = kmDNSHelperPListWriteFailed;
        LogMsg("%s: CFPropertyListWriteToStream failed", __func__);
        goto fin;
    }
    if (NULL == (bytes = CFWriteStreamCopyProperty(stream, kCFStreamPropertyDataWritten)))
    {
        err = kmDNSHelperCreationFailed;
        LogMsg("%s: CFWriteStreamCopyProperty failed", __func__);
        goto fin;
    }
    CFWriteStreamClose(stream);
    CFRelease(stream);
    stream = NULL;
    MACHRETRYLOOP_BEGIN(kr, retry, err, fin);
    kr = proxy_mDNSDynamicStoreSetConfig(getHelperPort(retry), key, subkey ? subkey : "", (vm_offset_t)CFDataGetBytePtr(bytes), CFDataGetLength(bytes));
    MACHRETRYLOOP_END(kr, retry, err, fin);

fin:
    if (NULL != stream) { CFWriteStreamClose(stream); CFRelease(stream); }
    if (NULL != bytes) CFRelease(bytes);
    (void)err;
}

void mDNSRequestBPF(void)
{
    kern_return_t kr = KERN_FAILURE;
    int retry = 0, err = 0;
    MACHRETRYLOOP_BEGIN(kr, retry, err, fin);
    kr = proxy_mDNSRequestBPF(getHelperPort(retry));
    MACHRETRYLOOP_END(kr, retry, err, fin);
fin:
    (void)err;
}

int mDNSPowerRequest(int key, int interval)
{
    kern_return_t kr = KERN_FAILURE;
    int retry = 0, err = 0;
    MACHRETRYLOOP_BEGIN(kr, retry, err, fin);
    kr = proxy_mDNSPowerRequest(getHelperPort(retry), key, interval, &err);
    MACHRETRYLOOP_END(kr, retry, err, fin);
fin:
    return err;
}

int mDNSSetLocalAddressCacheEntry(int ifindex, int family, const v6addr_t ip, const ethaddr_t eth)
{
    kern_return_t kr = KERN_FAILURE;
    int retry = 0, err = 0;
    MACHRETRYLOOP_BEGIN(kr, retry, err, fin);
    kr = proxy_mDNSSetLocalAddressCacheEntry(getHelperPort(retry), ifindex, family, (uint8_t*)ip, (uint8_t*)eth, &err);
    MACHRETRYLOOP_END(kr, retry, err, fin);
fin:
    return err;
}

void mDNSNotify(const char *title, const char *msg) // Both strings are UTF-8 text
{
    kern_return_t kr = KERN_FAILURE;
    int retry = 0, err = 0;
    MACHRETRYLOOP_BEGIN(kr, retry, err, fin);
    kr = proxy_mDNSNotify(getHelperPort(retry), title, msg);
    MACHRETRYLOOP_END(kr, retry, err, fin);
fin:
    (void)err;
}

int mDNSKeychainGetSecrets(CFArrayRef *result)
{
    CFPropertyListRef plist = NULL;
    CFDataRef bytes = NULL;
    kern_return_t kr = KERN_FAILURE;
    unsigned int numsecrets = 0;
    vm_offset_t secrets = 0;
    mach_msg_type_number_t secretsCnt = 0;
    int retry = 0, err = 0;

    MACHRETRYLOOP_BEGIN(kr, retry, err, fin);
    kr = proxy_mDNSKeychainGetSecrets(getHelperPort(retry), &numsecrets, &secrets, &secretsCnt, &err);
    MACHRETRYLOOP_END(kr, retry, err, fin);

    if (NULL == (bytes = CFDataCreateWithBytesNoCopy(kCFAllocatorDefault, (void*)secrets, secretsCnt, kCFAllocatorNull)))
    {
        err = kmDNSHelperCreationFailed;
        LogMsg("%s: CFDataCreateWithBytesNoCopy failed", __func__);
        goto fin;
    }
    if (NULL == (plist = CFPropertyListCreateFromXMLData(kCFAllocatorDefault, bytes, kCFPropertyListImmutable, NULL)))
    {
        err = kmDNSHelperInvalidPList;
        LogMsg("%s: CFPropertyListCreateFromXMLData failed", __func__);
        goto fin;
    }
    if (CFArrayGetTypeID() != CFGetTypeID(plist))
    {
        err = kmDNSHelperTypeError;
        LogMsg("%s: Unexpected result type", __func__);
        CFRelease(plist);
        plist = NULL;
        goto fin;
    }
    *result = (CFArrayRef)plist;

fin:
    if (bytes) CFRelease(bytes);
    if (secrets) vm_deallocate(mach_task_self(), secrets, secretsCnt);
    return err;
}

void mDNSConfigureServer(int updown, const char *const prefix, const domainname *const fqdn)
{
    kern_return_t kr = KERN_SUCCESS;
    int retry = 0, err = 0;
    char fqdnStr[MAX_ESCAPED_DOMAIN_NAME + 10] = { 0 }; // Assume the prefix is no larger than 10 chars
    if (fqdn)
    {
        mDNSPlatformStrCopy(fqdnStr, prefix);
        ConvertDomainNameToCString(fqdn, fqdnStr + mDNSPlatformStrLen(prefix));
    }
    MACHRETRYLOOP_BEGIN(kr, retry, err, fin);
    kr = proxy_mDNSConfigureServer(getHelperPort(retry), updown, fqdnStr);
    MACHRETRYLOOP_END(kr, retry, err, fin);
fin:
    (void)err;
}

int mDNSAutoTunnelSetKeys(int replacedelete, v6addr_t local_inner,
                          v6addr_t local_outer, short local_port, v6addr_t remote_inner,
                          v6addr_t remote_outer, short remote_port, const char* const prefix, const domainname *const fqdn)
{
    kern_return_t kr = KERN_SUCCESS;
    int retry = 0, err = 0;
    char fqdnStr[MAX_ESCAPED_DOMAIN_NAME + 10] = { 0 }; // Assume the prefix is no larger than 10 chars
    if (fqdn)
    {
        mDNSPlatformStrCopy(fqdnStr, prefix);
        ConvertDomainNameToCString(fqdn, fqdnStr + mDNSPlatformStrLen(prefix));
    }
    MACHRETRYLOOP_BEGIN(kr, retry, err, fin);
    kr = proxy_mDNSAutoTunnelSetKeys(getHelperPort(retry), replacedelete, local_inner, local_outer, local_port, remote_inner, remote_outer, remote_port, fqdnStr, &err);
    MACHRETRYLOOP_END(kr, retry, err, fin);
fin:
    return err;
}

void mDNSSendWakeupPacket(unsigned ifid, char *eth_addr, char *ip_addr, int iteration)
{
    kern_return_t kr = KERN_SUCCESS;
    int retry = 0, err = 0;
    MACHRETRYLOOP_BEGIN(kr, retry, err, fin);
    kr = proxy_mDNSSendWakeupPacket(getHelperPort(retry), ifid, eth_addr, ip_addr, iteration);
    MACHRETRYLOOP_END(kr, retry, err, fin);
fin:
    (void) err;
}

void mDNSPacketFilterControl(uint32_t command, char * ifname, uint32_t count, pfArray_t portArray, pfArray_t protocolArray)
{
    kern_return_t kr = KERN_SUCCESS;
    int retry = 0, err = 0;
    MACHRETRYLOOP_BEGIN(kr, retry, err, fin);
    kr = proxy_mDNSPacketFilterControl(getHelperPort(retry), command, ifname, count, portArray, protocolArray);
    MACHRETRYLOOP_END(kr, retry, err, fin);
fin:
    (void) err;
}

int mDNSSendKeepalive(v6addr_t sadd, v6addr_t dadd, uint16_t lport, uint16_t rport, unsigned seq, unsigned ack, uint16_t win)
{
    kern_return_t kr = KERN_FAILURE;
    int retry = 0, err = 0;
    MACHRETRYLOOP_BEGIN(kr, retry, err, fin);
    kr = proxy_mDNSSendKeepalive(getHelperPort(retry), sadd, dadd, lport, rport, seq, ack, win);
    MACHRETRYLOOP_END(kr, retry, err, fin);
fin:
    return err;
}


int mDNSInterfaceAdvtIoctl(const char *ifname, int op)
{
    kern_return_t kr = KERN_FAILURE;
    int retry = 0, err = 0;

    MACHRETRYLOOP_BEGIN(kr, retry, err, fin);
    kr = proxy_mDNSInterfaceAdvtIoctl(getHelperPort(retry), ifname, op);
    MACHRETRYLOOP_END(kr, retry, err, fin);

fin:
    return err;
}