/*
 * Services - controls services keeps track of their state
 *
 * Copyright 2007 Google (Mikolaj Zalewski)
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
 */

#define WIN32_LEAN_AND_MEAN

#include <stdarg.h>
#include <windows.h>
#include <winsvc.h>
#include <rpc.h>

#include "wine/unicode.h"
#include "wine/debug.h"
#include "svcctl.h"

#include "services.h"

#define MAX_SERVICE_NAME 260

WINE_DEFAULT_DEBUG_CHANNEL(service);

HANDLE g_hStartedEvent;
struct scmdatabase *active_database;

static const WCHAR SZ_LOCAL_SYSTEM[] = {'L','o','c','a','l','S','y','s','t','e','m',0};

/* Registry constants */
static const WCHAR SZ_SERVICES_KEY[] = { 'S','y','s','t','e','m','\\',
      'C','u','r','r','e','n','t','C','o','n','t','r','o','l','S','e','t','\\',
      'S','e','r','v','i','c','e','s',0 };

/* Service key values names */
static const WCHAR SZ_DISPLAY_NAME[]      = {'D','i','s','p','l','a','y','N','a','m','e',0 };
static const WCHAR SZ_TYPE[]              = {'T','y','p','e',0 };
static const WCHAR SZ_START[]             = {'S','t','a','r','t',0 };
static const WCHAR SZ_ERROR[]             = {'E','r','r','o','r','C','o','n','t','r','o','l',0 };
static const WCHAR SZ_IMAGE_PATH[]        = {'I','m','a','g','e','P','a','t','h',0};
static const WCHAR SZ_GROUP[]             = {'G','r','o','u','p',0};
static const WCHAR SZ_DEPEND_ON_SERVICE[] = {'D','e','p','e','n','d','O','n','S','e','r','v','i','c','e',0};
static const WCHAR SZ_DEPEND_ON_GROUP[]   = {'D','e','p','e','n','d','O','n','G','r','o','u','p',0};
static const WCHAR SZ_OBJECT_NAME[]       = {'O','b','j','e','c','t','N','a','m','e',0};
static const WCHAR SZ_TAG[]               = {'T','a','g',0};
static const WCHAR SZ_DESCRIPTION[]       = {'D','e','s','c','r','i','p','t','i','o','n',0};


DWORD service_create(LPCWSTR name, struct service_entry **entry)
{
    *entry = HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, sizeof(**entry));
    if (!*entry)
        return ERROR_NOT_ENOUGH_SERVER_MEMORY;
    (*entry)->name = strdupW(name);
    if (!(*entry)->name)
    {
        HeapFree(GetProcessHeap(), 0, *entry);
        return ERROR_NOT_ENOUGH_SERVER_MEMORY;
    }
    (*entry)->control_pipe = INVALID_HANDLE_VALUE;
    return ERROR_SUCCESS;
}

void free_service_entry(struct service_entry *entry)
{
    HeapFree(GetProcessHeap(), 0, entry->name);
    HeapFree(GetProcessHeap(), 0, entry->config.lpBinaryPathName);
    HeapFree(GetProcessHeap(), 0, entry->config.lpDependencies);
    HeapFree(GetProcessHeap(), 0, entry->config.lpLoadOrderGroup);
    HeapFree(GetProcessHeap(), 0, entry->config.lpServiceStartName);
    HeapFree(GetProcessHeap(), 0, entry->config.lpDisplayName);
    HeapFree(GetProcessHeap(), 0, entry->description);
    HeapFree(GetProcessHeap(), 0, entry->dependOnServices);
    HeapFree(GetProcessHeap(), 0, entry->dependOnGroups);
    CloseHandle(entry->control_mutex);
    CloseHandle(entry->control_pipe);
    CloseHandle(entry->status_changed_event);
    HeapFree(GetProcessHeap(), 0, entry);
}

static DWORD load_service_config(HKEY hKey, struct service_entry *entry)
{
    DWORD err;
    WCHAR *wptr;

    if ((err = load_reg_string(hKey, SZ_IMAGE_PATH,   TRUE, &entry->config.lpBinaryPathName)) != 0)
        return err;
    if ((err = load_reg_string(hKey, SZ_GROUP,        0,    &entry->config.lpLoadOrderGroup)) != 0)
        return err;
    if ((err = load_reg_string(hKey, SZ_OBJECT_NAME,  TRUE, &entry->config.lpServiceStartName)) != 0)
        return err;
    if ((err = load_reg_string(hKey, SZ_DISPLAY_NAME, 0,    &entry->config.lpDisplayName)) != 0)
        return err;
    if ((err = load_reg_string(hKey, SZ_DESCRIPTION,  0,    &entry->description)) != 0)
        return err;
    if ((err = load_reg_multisz(hKey, SZ_DEPEND_ON_SERVICE, &entry->dependOnServices)) != 0)
        return err;
    if ((err = load_reg_multisz(hKey, SZ_DEPEND_ON_GROUP,   &entry->dependOnGroups)) != 0)
        return err;

    if ((err = load_reg_dword(hKey, SZ_TYPE,  &entry->config.dwServiceType)) != 0)
        return err;
    if ((err = load_reg_dword(hKey, SZ_START, &entry->config.dwStartType)) != 0)
        return err;
    if ((err = load_reg_dword(hKey, SZ_ERROR, &entry->config.dwErrorControl)) != 0)
        return err;
    if ((err = load_reg_dword(hKey, SZ_TAG,   &entry->config.dwTagId)) != 0)
        return err;

    WINE_TRACE("Image path           = %s\n", wine_dbgstr_w(entry->config.lpBinaryPathName) );
    WINE_TRACE("Group                = %s\n", wine_dbgstr_w(entry->config.lpLoadOrderGroup) );
    WINE_TRACE("Service account name = %s\n", wine_dbgstr_w(entry->config.lpServiceStartName) );
    WINE_TRACE("Display name         = %s\n", wine_dbgstr_w(entry->config.lpDisplayName) );
    WINE_TRACE("Service dependancies : %s\n", entry->dependOnServices[0] ? "" : "(none)");
    for (wptr = entry->dependOnServices; *wptr; wptr += strlenW(wptr) + 1)
        WINE_TRACE("    * %s\n", wine_dbgstr_w(wptr));
    WINE_TRACE("Group dependancies   : %s\n", entry->dependOnGroups[0] ? "" : "(none)");
    for (wptr = entry->dependOnGroups; *wptr; wptr += strlenW(wptr) + 1)
        WINE_TRACE("    * %s\n", wine_dbgstr_w(wptr));

    return ERROR_SUCCESS;
}

static DWORD reg_set_string_value(HKEY hKey, LPCWSTR value_name, LPCWSTR string)
{
    if (!string)
    {
        DWORD err;
        err = RegDeleteValueW(hKey, value_name);
        if (err != ERROR_FILE_NOT_FOUND)
            return err;

        return ERROR_SUCCESS;
    }

    return RegSetValueExW(hKey, value_name, 0, REG_SZ, (LPBYTE)string, sizeof(WCHAR)*(strlenW(string) + 1));
}

DWORD save_service_config(struct service_entry *entry)
{
    DWORD err;
    HKEY hKey = NULL;

    err = RegCreateKeyW(entry->db->root_key, entry->name, &hKey);
    if (err != ERROR_SUCCESS)
        goto cleanup;

    if ((err = reg_set_string_value(hKey, SZ_DISPLAY_NAME, entry->config.lpDisplayName)) != 0)
        goto cleanup;
    if ((err = reg_set_string_value(hKey, SZ_IMAGE_PATH, entry->config.lpBinaryPathName)) != 0)
        goto cleanup;
    if ((err = reg_set_string_value(hKey, SZ_GROUP, entry->config.lpLoadOrderGroup)) != 0)
        goto cleanup;
    if ((err = reg_set_string_value(hKey, SZ_OBJECT_NAME, entry->config.lpServiceStartName)) != 0)
        goto cleanup;
    if ((err = reg_set_string_value(hKey, SZ_DESCRIPTION, entry->description)) != 0)
        goto cleanup;
    if ((err = RegSetValueExW(hKey, SZ_START, 0, REG_DWORD, (LPBYTE)&entry->config.dwStartType, sizeof(DWORD))) != 0)
        goto cleanup;
    if ((err = RegSetValueExW(hKey, SZ_ERROR, 0, REG_DWORD, (LPBYTE)&entry->config.dwErrorControl, sizeof(DWORD))) != 0)
        goto cleanup;

    if ((err = RegSetValueExW(hKey, SZ_TYPE, 0, REG_DWORD, (LPBYTE)&entry->config.dwServiceType, sizeof(DWORD))) != 0)
        goto cleanup;

    if (entry->config.dwTagId)
        err = RegSetValueExW(hKey, SZ_TAG, 0, REG_DWORD, (LPBYTE)&entry->config.dwTagId, sizeof(DWORD));
    else
        err = RegDeleteValueW(hKey, SZ_TAG);

    if (err != 0 && err != ERROR_FILE_NOT_FOUND)
        goto cleanup;

    err = ERROR_SUCCESS;
cleanup:
    RegCloseKey(hKey);
    return err;
}

DWORD scmdatabase_add_service(struct scmdatabase *db, struct service_entry *service)
{
    int err;
    service->db = db;
    if ((err = save_service_config(service)) != ERROR_SUCCESS)
    {
        WINE_ERR("Couldn't store service configuration: error %u\n", err);
        return ERROR_GEN_FAILURE;
    }

    list_add_tail(&db->services, &service->entry);
    return ERROR_SUCCESS;
}

DWORD scmdatabase_remove_service(struct scmdatabase *db, struct service_entry *service)
{
    int err;

    err = RegDeleteTreeW(db->root_key, service->name);

    if (err != 0)
        return err;

    list_remove(&service->entry);
    service->entry.next = service->entry.prev = NULL;
    return ERROR_SUCCESS;
}

BOOL validate_service_name(LPCWSTR name)
{
    return (name && name[0] && !strchrW(name, '/') && !strchrW(name, '\\'));
}

BOOL validate_service_config(struct service_entry *entry)
{
    if (entry->config.dwServiceType & SERVICE_WIN32 && (entry->config.lpBinaryPathName == NULL || !entry->config.lpBinaryPathName[0]))
    {
        WINE_ERR("Service %s is Win32 but have no image path set\n", wine_dbgstr_w(entry->name));
        return FALSE;
    }

    switch (entry->config.dwServiceType)
    {
    case SERVICE_KERNEL_DRIVER:
    case SERVICE_FILE_SYSTEM_DRIVER:
    case SERVICE_WIN32_OWN_PROCESS:
    case SERVICE_WIN32_SHARE_PROCESS:
        /* No problem */
        break;
    case SERVICE_WIN32_OWN_PROCESS | SERVICE_INTERACTIVE_PROCESS:
    case SERVICE_WIN32_SHARE_PROCESS | SERVICE_INTERACTIVE_PROCESS:
        /* These can be only run as LocalSystem */
        if (entry->config.lpServiceStartName && strcmpiW(entry->config.lpServiceStartName, SZ_LOCAL_SYSTEM) != 0)
        {
            WINE_ERR("Service %s is interactive but has a start name\n", wine_dbgstr_w(entry->name));
            return FALSE;
        }
        break;
    default:
        WINE_ERR("Service %s have unknown service type\n", wine_dbgstr_w(entry->name));
        return FALSE;
    }

    /* StartType can only be a single value (if several values are mixed the result is probably not what was intended) */
    if (entry->config.dwStartType > SERVICE_DISABLED)
    {
        WINE_ERR("Service %s have unknown start type\n", wine_dbgstr_w(entry->name));
        return FALSE;
    }

    /* SERVICE_BOOT_START and SERVICE_SYSTEM_START or only allowed for driver services */
    if (((entry->config.dwStartType == SERVICE_BOOT_START) || (entry->config.dwStartType == SERVICE_SYSTEM_START)) &&
        ((entry->config.dwServiceType & SERVICE_WIN32_OWN_PROCESS) || (entry->config.dwServiceType & SERVICE_WIN32_SHARE_PROCESS)))
    {
        WINE_ERR("Service %s - SERVICE_BOOT_START and SERVICE_SYSTEM_START are only allowed for driver services\n", wine_dbgstr_w(entry->name));
        return FALSE;
    }

    if (entry->config.lpServiceStartName == NULL)
        entry->config.lpServiceStartName = strdupW(SZ_LOCAL_SYSTEM);

    return TRUE;
}


struct service_entry *scmdatabase_find_service(struct scmdatabase *db, LPCWSTR name)
{
    struct service_entry *service;

    LIST_FOR_EACH_ENTRY(service, &db->services, struct service_entry, entry)
    {
        if (strcmpiW(name, service->name) == 0)
            return service;
    }

    return NULL;
}

struct service_entry *scmdatabase_find_service_by_displayname(struct scmdatabase *db, LPCWSTR name)
{
    struct service_entry *service;

    LIST_FOR_EACH_ENTRY(service, &db->services, struct service_entry, entry)
    {
        if (strcmpiW(name, service->config.lpDisplayName) == 0)
            return service;
    }

    return NULL;
}

void release_service(struct service_entry *service)
{
    if (InterlockedDecrement(&service->ref_count) == 0 && is_marked_for_delete(service))
        free_service_entry(service);
}

static DWORD scmdatabase_create(struct scmdatabase **db)
{
    DWORD err;

    *db = HeapAlloc(GetProcessHeap(), 0, sizeof(**db));
    if (!*db)
        return ERROR_NOT_ENOUGH_SERVER_MEMORY;

    (*db)->service_start_lock = FALSE;
    list_init(&(*db)->services);

    InitializeCriticalSection(&(*db)->cs);

    err = RegCreateKeyExW(HKEY_LOCAL_MACHINE, SZ_SERVICES_KEY, 0, NULL,
                          REG_OPTION_NON_VOLATILE, KEY_ALL_ACCESS, NULL,
                          &(*db)->root_key, NULL);
    if (err != ERROR_SUCCESS)
        HeapFree(GetProcessHeap(), 0, *db);

    return err;
}

static void scmdatabase_destroy(struct scmdatabase *db)
{
    RegCloseKey(db->root_key);
    DeleteCriticalSection(&db->cs);
    HeapFree(GetProcessHeap(), 0, db);
}

static DWORD scmdatabase_load_services(struct scmdatabase *db)
{
    DWORD err;
    int i;

    for (i = 0; TRUE; i++)
    {
        WCHAR szName[MAX_SERVICE_NAME];
        struct service_entry *entry;
        HKEY hServiceKey;

        err = RegEnumKeyW(db->root_key, i, szName, MAX_SERVICE_NAME);
        if (err == ERROR_NO_MORE_ITEMS)
            break;

        if (err != 0)
        {
            WINE_ERR("Error %d reading key %d name - skipping\n", err, i);
            continue;
        }

        err = service_create(szName, &entry);
        if (err != ERROR_SUCCESS)
            break;

        WINE_TRACE("Loading service %s\n", wine_dbgstr_w(szName));
        err = RegOpenKeyExW(db->root_key, szName, 0, KEY_READ | KEY_WRITE, &hServiceKey);
        if (err == ERROR_SUCCESS)
        {
            err = load_service_config(hServiceKey, entry);
            RegCloseKey(hServiceKey);
        }

        if (err != ERROR_SUCCESS)
        {
            WINE_ERR("Error %d reading registry key for service %s - skipping\n", err, wine_dbgstr_w(szName));
            free_service_entry(entry);
            continue;
        }

        if (entry->config.dwServiceType == 0)
        {
            /* Maybe an application only wrote some configuration in the service key. Continue silently */
            WINE_TRACE("Even the service type not set for service %s - skipping\n", wine_dbgstr_w(szName));
            free_service_entry(entry);
            continue;
        }

        if (!validate_service_config(entry))
        {
            WINE_ERR("Invalid configuration of service %s - skipping\n", wine_dbgstr_w(szName));
            free_service_entry(entry);
            continue;
        }

        entry->status.dwServiceType = entry->config.dwServiceType;
        entry->status.dwCurrentState = SERVICE_STOPPED;
        entry->status.dwWin32ExitCode = ERROR_SERVICE_NEVER_STARTED;
        entry->db = db;
        /* all other fields are zero */

        list_add_tail(&db->services, &entry->entry);
    }
    return ERROR_SUCCESS;
}

DWORD scmdatabase_lock_startup(struct scmdatabase *db)
{
    if (InterlockedCompareExchange(&db->service_start_lock, TRUE, FALSE))
        return ERROR_SERVICE_DATABASE_LOCKED;
    return ERROR_SUCCESS;
}

void scmdatabase_unlock_startup(struct scmdatabase *db)
{
    InterlockedCompareExchange(&db->service_start_lock, FALSE, TRUE);
}

void scmdatabase_lock_shared(struct scmdatabase *db)
{
    EnterCriticalSection(&db->cs);
}

void scmdatabase_lock_exclusive(struct scmdatabase *db)
{
    EnterCriticalSection(&db->cs);
}

void scmdatabase_unlock(struct scmdatabase *db)
{
    LeaveCriticalSection(&db->cs);
}

void service_lock_shared(struct service_entry *service)
{
    EnterCriticalSection(&service->db->cs);
}

void service_lock_exclusive(struct service_entry *service)
{
    EnterCriticalSection(&service->db->cs);
}

void service_unlock(struct service_entry *service)
{
    LeaveCriticalSection(&service->db->cs);
}

int main(int argc, char *argv[])
{
    static const WCHAR svcctl_started_event[] = SVCCTL_STARTED_EVENT;
    DWORD err;
    g_hStartedEvent = CreateEventW(NULL, TRUE, FALSE, svcctl_started_event);
    err = scmdatabase_create(&active_database);
    if (err != ERROR_SUCCESS)
        return err;
    if ((err = scmdatabase_load_services(active_database)) != ERROR_SUCCESS)
        return err;
    err = RPC_MainLoop();
    scmdatabase_destroy(active_database);
    return err;
}