/* **********************************************************
 * Copyright (c) 2011-2022 Google, Inc.  All rights reserved.
 * Copyright (c) 2008-2010 VMware, Inc.  All rights reserved.
 * **********************************************************/

/*
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * * Redistributions of source code must retain the above copyright notice,
 *   this list of conditions and the following disclaimer.
 *
 * * Redistributions in binary form must reproduce the above copyright notice,
 *   this list of conditions and the following disclaimer in the documentation
 *   and/or other materials provided with the distribution.
 *
 * * Neither the name of VMware, Inc. nor the names of its contributors may be
 *   used to endorse or promote products derived from this software without
 *   specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL VMWARE, INC. OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
 * DAMAGE.
 */

#include <stdlib.h> /* for malloc */
#include <stdio.h>
#include <string.h>
#include "utils.h"
#include "share.h"
#include "utils.h"
#include "dr_config.h"
#include "our_tchar.h"
#include "dr_frontend.h"
#include "drlibc.h"

/* We use DR's snprintf for consistent behavior when len==max.
 * TODO: Change all of libutil by changing our_tchar.h.
 */
#undef _snprintf
#define _snprintf d_r_snprintf
int
d_r_snprintf(char *s, size_t max, const char *fmt, ...);

#ifdef WINDOWS
#    include <windows.h>
#    include <io.h> /* for _get_osfhandle */
#    include "processes.h"
#    include "mfapi.h" /* for PLATFORM_WIN_2000 */

#    define RELEASE32_DLL _TEXT("\\lib32\\release\\dynamorio.dll")
#    define DEBUG32_DLL _TEXT("\\lib32\\debug\\dynamorio.dll")
#    define RELEASE64_DLL _TEXT("\\lib64\\release\\dynamorio.dll")
#    define DEBUG64_DLL _TEXT("\\lib64\\debug\\dynamorio.dll")
#    define LOG_SUBDIR _TEXT("\\logs")
#    define LIB32_SUBDIR _TEXT("\\lib32")
#    define PREINJECT32_DLL _TEXT("\\lib32\\drpreinject.dll")
#    define PREINJECT64_DLL _TEXT("\\lib64\\drpreinject.dll")
#    undef _sntprintf
#    define _sntprintf d_r_snprintf_wide
int
d_r_snprintf_wide(wchar_t *s, size_t max, const wchar_t *fmt, ...);
#else
#    include <sys/stat.h>
#    include <sys/types.h>
#    include <unistd.h>
#    if defined(MACOS) || defined(ANDROID)
#        include <sys/syscall.h>
#    else
#        include <syscall.h>
#    endif

#    define RELEASE32_DLL "/lib32/release/libdynamorio.so"
#    define DEBUG32_DLL "/lib32/debug/libdynamorio.so"
#    define RELEASE64_DLL "/lib64/release/libdynamorio.so"
#    define DEBUG64_DLL "/lib64/debug/libdynamorio.so"
#    define LOG_SUBDIR "/logs"
#    define LIB32_SUBDIR "/lib32/"
#    undef _sntprintf
#    define _sntprintf d_r_snprintf
int
d_r_snprintf_wide(wchar_t *s, size_t max, const wchar_t *fmt, ...);

extern bool
create_nudge_signal_payload(siginfo_t *info OUT, uint action_mask, client_id_t client_id,
                            uint flags, uint64 client_arg);
#endif

/* The minimum option size is 3, e.g., "-x ".  Note that we need the
 * NULL term too so "-x -y" needs 6 characters.
 */
#define MAX_NUM_OPTIONS (DR_MAX_OPTIONS_LENGTH / 3)

/* Upper bound on the length of an fopen mode string, including the null
 * terminator.  For example, "rw+b\0" or "ra\0".
 */
enum { MAX_MODE_STRING_SIZE = 16 };

/* Data structs to hold info about the DYNAMORIO_OPTION registry entry */
typedef struct _client_opt_t {
    TCHAR *path;
    client_id_t id;
    TCHAR *opts;
    bool alt_bitwidth;
} client_opt_t;

typedef struct _opt_info_t {
    dr_operation_mode_t mode;
    TCHAR *extra_opts[MAX_NUM_OPTIONS];
    size_t num_extra_opts;
    /* note that clients are parsed and stored in priority order */
    client_opt_t *client_opts[MAX_CLIENT_LIBS];
    size_t num_clients;
} opt_info_t;

/* Does a straight copy when TCHAR is char, and a widening conversion when
 * TCHAR is wchar_t.  Does not null terminate for use in buffered printing.
 */
static void
convert_to_tchar(TCHAR *dst, const char *src, size_t dst_sz)
{
#ifdef _UNICODE
#    ifdef DEBUG
    int res =
#    endif
        MultiByteToWideChar(CP_UTF8, 0 /*=>MB_PRECOMPOSED*/, src, -1 /*null-term*/, dst,
                            (int)dst_sz);
    DO_ASSERT(res > 0 && "convert_to_tchar failed");
#else
    strncpy(dst, src, dst_sz);
#endif
}

/* Function to iterate over the options in a DYNAMORIO_OPTIONS string.
 * For the purposes of this function, we're not differentiating
 * between an option and an option argument.  We're simply looking for
 * space-separated strings while taking into account that some strings
 * can be quoted.  'ptr' should point to the current location in the
 * options string; the option is copied to 'token'
 */
static TCHAR *
get_next_token(TCHAR *ptr, TCHAR *token)
{
    /* advance to next non-space character */
    while (*ptr == _T(' ')) {
        ptr++;
    }

    /* check for end-of-string */
    if (*ptr == _T('\0')) {
        token[0] = _T('\0');
        return NULL;
    }

    /* for quoted options, copy until the closing quote */
    if (*ptr == _T('\"') || *ptr == _T('\'') || *ptr == _T('`')) {
        TCHAR quote = *ptr;
        *token++ = *ptr++;
        while (*ptr != _T('\0')) {
            *token++ = *ptr++;
            if (ptr[-1] == quote && ptr[-2] != _T('\\')) {
                break;
            }
        }
    }

    /* otherwise copy until the next space character */
    else {
        while (*ptr != _T(' ') && *ptr != _T('\0')) {
            *token++ = *ptr++;
        }
    }

    *token = _T('\0');
    return ptr;
}

static void
copy_up_to_max(char *buf, size_t max, TCHAR *src)
{
    size_t len = MIN(max - 1, _tcslen(src));
    _snprintf(buf, len, TSTR_FMT, src);
    buf[len] = '\0';
}

/* Allocate a new client_opt_t */
static client_opt_t *
new_client_opt(const TCHAR *path, client_id_t id, const TCHAR *opts, bool alt_bitwidth)
{
    size_t len;
    client_opt_t *opt = (client_opt_t *)malloc(sizeof(client_opt_t));
    if (opt == NULL) {
        return NULL;
    }

    opt->id = id;
    opt->alt_bitwidth = alt_bitwidth;

    len = MIN(MAXIMUM_PATH - 1, _tcslen(path));
    opt->path = malloc((len + 1) * sizeof(opt->path[0]));
    _tcsncpy(opt->path, path, len);
    opt->path[len] = _T('\0');

    len = MIN(DR_MAX_OPTIONS_LENGTH - 1, _tcslen(opts));
    opt->opts = malloc((len + 1) * sizeof(opt->opts[0]));
    _tcsncpy(opt->opts, opts, len);
    opt->opts[len] = _T('\0');

    return opt;
}

/* Free a client_opt_t */
static void
free_client_opt(client_opt_t *opt)
{
    if (opt == NULL) {
        return;
    }
    if (opt->path != NULL) {
        free(opt->path);
    }
    if (opt->opts != NULL) {
        free(opt->opts);
    }
    free(opt);
}

/* Add another client to an opt_info_t struct */
static dr_config_status_t
add_client_lib(opt_info_t *opt_info, client_id_t id, size_t pri, const TCHAR *path,
               const TCHAR *opts, bool alt_bitwidth)
{
    size_t i;

    if (opt_info->num_clients >= MAX_CLIENT_LIBS) {
        return DR_FAILURE;
    }

    if (pri > opt_info->num_clients) {
        return DR_ID_INVALID;
    }

    /* shift existing entries to make space for the new client info */
    for (i = opt_info->num_clients; i > pri; i--) {
        opt_info->client_opts[i] = opt_info->client_opts[i - 1];
    }

    opt_info->client_opts[pri] = new_client_opt(path, id, opts, alt_bitwidth);
    opt_info->num_clients++;

    return DR_SUCCESS;
}

static dr_config_status_t
remove_client_lib(opt_info_t *opt_info, client_id_t id)
{
    size_t i, j;
    dr_config_status_t status = DR_ID_INVALID;
    for (i = 0; i < opt_info->num_clients; i++) {
        if (opt_info->client_opts[i]->id == id) {
            free_client_opt(opt_info->client_opts[i]);

            /* shift remaining entries down */
            for (j = i; j < opt_info->num_clients - 1; j++) {
                opt_info->client_opts[j] = opt_info->client_opts[j + 1];
            }

            opt_info->num_clients--;
            status = DR_SUCCESS;
            /* Keep searching to also remove any alt-bitwidth for the same id. */
            i--;
        }
    }

    return status;
}

/* Add an 'extra' option (non-client related option) to an opt_info_t struct */
static dr_config_status_t
add_extra_option(opt_info_t *opt_info, const TCHAR *opt)
{
    if (opt != NULL && opt[0] != _T('\0')) {
        size_t idx, len;
        idx = opt_info->num_extra_opts;
        if (idx >= MAX_NUM_OPTIONS) {
            return DR_FAILURE;
        }

        len = MIN(DR_MAX_OPTIONS_LENGTH - 1, _tcslen(opt));
        opt_info->extra_opts[idx] =
            malloc((len + 1) * sizeof(opt_info->extra_opts[idx][0]));
        _tcsncpy(opt_info->extra_opts[idx], opt, len);
        opt_info->extra_opts[idx][len] = _T('\0');

        opt_info->num_extra_opts++;
    }

    return DR_SUCCESS;
}

static dr_config_status_t
add_extra_option_char(opt_info_t *opt_info, const char *opt)
{
    if (opt != NULL && opt[0] != '\0') {
        TCHAR wbuf[DR_MAX_OPTIONS_LENGTH];
        convert_to_tchar(wbuf, opt, DR_MAX_OPTIONS_LENGTH);
        NULL_TERMINATE_BUFFER(wbuf);
        return add_extra_option(opt_info, wbuf);
    }

    return DR_SUCCESS;
}

/* Free allocated memory in an opt_info_t */
static void
free_opt_info(opt_info_t *opt_info)
{
    size_t i;
    for (i = 0; i < opt_info->num_clients; i++) {
        free_client_opt(opt_info->client_opts[i]);
    }
    for (i = 0; i < opt_info->num_extra_opts; i++) {
        free(opt_info->extra_opts[i]);
    }
}

/***************************************************************************
 * i#85/PR 212034 and i#265/PR 486139: use config files
 *
 * The API uses char* here but be careful b/c this file is build w/ UNICODE
 * so we use *A versions of Windows API routines.
 * Also note that I left many types as TCHAR for less change in handling
 * PARAMS_IN_REGISTRY and config files: eventually should convert all
 * to char.
 */

#ifdef PARAMS_IN_REGISTRY
#    define IF_REG_ELSE(x, y) x
#    define PARAM_STR(name) L_IF_WIN(name)
#else
#    define PARAM_STR(name) name
#    define IF_REG_ELSE(x, y) y
#endif

#ifndef PARAMS_IN_REGISTRY
/* DYNAMORIO_VAR_CONFIGDIR is searched first, and then these: */
#    ifdef WINDOWS
#        define LOCAL_CONFIG_ENV "USERPROFILE"
#        define LOCAL_CONFIG_SUBDIR "dynamorio"
#    else
#        define LOCAL_CONFIG_ENV "HOME"
#        define LOCAL_CONFIG_SUBDIR ".dynamorio"
#    endif
#    define GLOBAL_CONFIG_SUBDIR "config"
#    define CFG_SFX_64 "config64"
#    define CFG_SFX_32 "config32"
#    ifdef X64
#        define CFG_SFX CFG_SFX_64
#    else
#        define CFG_SFX CFG_SFX_32
#    endif

static const char *
get_config_sfx(dr_platform_t dr_platform)
{
    if (dr_platform == DR_PLATFORM_DEFAULT)
        return CFG_SFX;
    else if (dr_platform == DR_PLATFORM_32BIT)
        return CFG_SFX_32;
    else if (dr_platform == DR_PLATFORM_64BIT)
        return CFG_SFX_64;
    else
        DO_ASSERT(false);
    return "";
}

static bool
env_var_exists(const char *name, char *buf, size_t buflen)
{
    return drfront_get_env_var(name, buf, buflen) == DRFRONT_SUCCESS;
}

static bool
is_config_dir_valid(const char *dir)
{
    /* i#1701 Android support: on Android devices (and in some cases ChromeOS),
     * $HOME is read-only.  Thus we want to check for writability.
     */
    bool ret = false;
    return drfront_access(dir, DRFRONT_WRITE, &ret) == DRFRONT_SUCCESS && ret;
}

/* If find_temp, will use a temp dir; else will fail if no standard config dir. */
static bool
get_config_dir(bool global, char *fname, size_t fname_len, bool find_temp)
{
    char dir[MAXIMUM_PATH];
    const char *subdir = "";
    bool res = false;
    /* We return the last-tried dir on failure */
    NULL_TERMINATE_BUFFER(dir);
    fname[0] = '\0';
    if (global) {
#    ifdef WINDOWS
        _snprintf(dir, BUFFER_SIZE_ELEMENTS(dir), TSTR_FMT, get_dynamorio_home());
        NULL_TERMINATE_BUFFER(dir);
        subdir = GLOBAL_CONFIG_SUBDIR;
#    else
        /* FIXME i#840: Support global config files by porting more of utils.c.
         */
        return false;
#    endif
    } else {
        /* DYNAMORIO_CONFIGDIR takes precedence, and we do not check for
         * is_config_dir_valid() b/c the user explicitly asked for it.
         * The user can set TMPDIR if checks are desired.
         */
        if (!env_var_exists(DYNAMORIO_VAR_CONFIGDIR, dir, BUFFER_SIZE_ELEMENTS(dir))) {
            if (!env_var_exists(LOCAL_CONFIG_ENV, dir, BUFFER_SIZE_ELEMENTS(dir)) ||
                !is_config_dir_valid(dir)) {
                if (!find_temp)
                    goto get_config_dir_done;
                /* Attempt to make things work for non-interactive users (i#939) */
                if ((!env_var_exists("TMP", dir, BUFFER_SIZE_ELEMENTS(dir)) ||
                     !is_config_dir_valid(dir)) &&
                    (!env_var_exists("TEMP", dir, BUFFER_SIZE_ELEMENTS(dir)) ||
                     !is_config_dir_valid(dir)) &&
                    (!env_var_exists("TMPDIR", dir, BUFFER_SIZE_ELEMENTS(dir)) ||
                     !is_config_dir_valid(dir))) {
#    ifdef WINDOWS
                    /* There is no straightforward hardcoded fallback for temp dirs
                     * on Windows.  But for that reason even a sandbox will leave
                     * TMP and/or TEMP set so we don't expect to hit this case.
                     */
                    goto get_config_dir_done;
#    else
#        ifdef ANDROID
                    /* This dir is not always present, but often is.
                     * We can't easily query the Java layer for the "cache dir".
                     * DrMi#1857: for Android apps, this is disallowed by SELinux
                     * (and we found no way to chcon to fix that), which does allow
                     * /sdcard but it's not world-writable.  We have to rely on the
                     * user setting TMPDIR to the app's data dir.
                     */
#            define TMP_DIR "/data/local/tmp"
#        else
#            define TMP_DIR "/tmp"
#        endif
                    /* Prefer /tmp to cwd as the former is more likely writable */
                    strncpy(dir, TMP_DIR, BUFFER_SIZE_ELEMENTS(dir));
                    NULL_TERMINATE_BUFFER(dir);
                    if ((!file_exists(dir) || !is_config_dir_valid(dir)) &&
                        /* Prefer getcwd over PWD env var which is not always set
                         * (e.g., on Android, it's in "adb shell" but not child)
                         */
                        (getcwd(dir, BUFFER_SIZE_ELEMENTS(dir)) == NULL ||
                         !is_config_dir_valid(dir))) {
#        ifdef ANDROID
                        /* Put back TMP_DIR for better error msg in caller */
                        strncpy(dir, TMP_DIR, BUFFER_SIZE_ELEMENTS(dir));
                        NULL_TERMINATE_BUFFER(dir);
#        endif
                        goto get_config_dir_done;
                    }
#    endif
                }
            }
            /* For anon config files (.0config32), we set DYNAMORIO_VAR_CONFIGDIR to be
             * either LOCAL_CONFIG_ENV or TMP to ensure DR finds the same config file!
             */
#    ifdef WINDOWS
            {
                TCHAR wbuf[MAXIMUM_PATH];
                convert_to_tchar(wbuf, dir, BUFFER_SIZE_ELEMENTS(wbuf));
                NULL_TERMINATE_BUFFER(wbuf);
                if (!SetEnvironmentVariableW(L_DYNAMORIO_VAR_CONFIGDIR, wbuf))
                    goto get_config_dir_done;
            }
#    else
            if (setenv(DYNAMORIO_VAR_CONFIGDIR, dir, 1 /*replace*/) != 0)
                goto get_config_dir_done;
#    endif
        }
        subdir = LOCAL_CONFIG_SUBDIR;
    }
    res = true;
get_config_dir_done:
    /* On failure, we still want to copy the last-tried dir out so drdeploy can have a
     * nicer error msg.
     */
    _snprintf(fname, fname_len, "%s/%s", dir, subdir);
    fname[fname_len - 1] = '\0';
    return res;
}

/* No support yet here to create some types of files the core supports:
 * - system config dir by reading home reg key: plan is to
 *   add a global setting to use that, so no change to params in API
 * - default0.config
 */
static bool
get_config_file_name(const char *process_name, process_id_t pid, bool global,
                     dr_platform_t dr_platform, char *fname, size_t fname_len)
{
    size_t dir_len;
#    ifdef WINDOWS
    drfront_status_t res;
#    endif
    /* i#939: we can't fall back to tmp dirs here b/c it's too late to set
     * the DYNAMORIO_CONFIGDIR env var (child is already created).
     */
    if (!get_config_dir(global, fname, fname_len, false)) {
        DO_ASSERT(false && "get_config_dir failed: check permissions");
        return false;
    }
#    ifdef WINDOWS
    /* make sure subdir exists*/
    res = drfront_create_dir(fname);
    if (res != DRFRONT_SUCCESS && res != DRFRONT_ERROR_FILE_EXISTS) {
        DO_ASSERT(false && "failed to create subdir: check permissions");
        return false;
    }
#    else
    {
        struct stat64 st;
        /* DrMi#1857: with both native and wrapped Android apps using the same
         * config dir but running as different users, we need the dir to be
         * world-writable (this is when SELinux is disabled and a common config
         * dir is used).
         */
        mkdir(fname, IF_ANDROID_ELSE(0777, 0770));
#        ifdef ANDROID
        chmod(fname, 0777); /* umask probably stripped out o+w, so we chmod */
#        endif
        /* Use the raw syscall to avoid glibc 2.33 deps (i#5474). */
        if (dr_stat_syscall(fname, &st) != 0 || !S_ISDIR(st.st_mode)) {
            DO_ASSERT(false && "failed to create subdir: check permissions");
            return false;
        }
    }
#    endif
    dir_len = strlen(fname);
    if (pid > 0) {
        /* <root>/appname.<pid>.1config */
        _snprintf(fname + dir_len, fname_len - dir_len, "/%s.%d.1%s", process_name, pid,
                  get_config_sfx(dr_platform));
    } else {
        /* <root>/appname.config */
        _snprintf(fname + dir_len, fname_len - dir_len, "/%s.%s", process_name,
                  get_config_sfx(dr_platform));
    }
    fname[fname_len - 1] = '\0';
    return true;
}

static FILE *
open_config_file(const char *process_name, process_id_t pid, bool global,
                 dr_platform_t dr_platform, bool read, bool write, bool overwrite)
{
    TCHAR wfname[MAXIMUM_PATH];
    char fname[MAXIMUM_PATH];
    TCHAR mode[MAX_MODE_STRING_SIZE];
    int i = 0;
    FILE *f;
    DO_ASSERT(read || write);
    DO_ASSERT(!(read && overwrite) && "read+overwrite incompatible");
    if (!get_config_file_name(process_name, pid, global, dr_platform, fname,
                              BUFFER_SIZE_ELEMENTS(fname))) {
        DO_ASSERT(false && "get_config_file_name failed");
        return NULL;
    }

    /* XXX: Checking for existence before opening is racy. */
    convert_to_tchar(wfname, fname, BUFFER_SIZE_ELEMENTS(wfname));
    NULL_TERMINATE_BUFFER(wfname);
    if (!read && write && !overwrite && file_exists(wfname)) {
        return NULL;
    }

    /* Careful, Windows fopen aborts the process on invalid mode strings.
     * Order matters.  Modifiers like 'b' have to come after standard characters
     * like r, w, and +.
     */
    if (read)
        mode[i++] = _T('r');
    if (write)
        mode[i++] = (read ? _T('+') : _T('w'));
    mode[i++] = _T('b'); /* Avoid CRLF translation on Windows. */
    mode[i++] = _T('\0');
    DO_ASSERT(i <= BUFFER_SIZE_ELEMENTS(mode));
    NULL_TERMINATE_BUFFER(mode);
    f = _wfopen(wfname, mode);
    return f;
}

static void
trim_trailing_newline(TCHAR *line)
{
    TCHAR *cur = line + _tcslen(line) - 1;
    while (cur >= line && (*cur == _T('\n') || *cur == _T('\r'))) {
        *cur = _T('\0');
        cur--;
    }
}

/* Copies the value for var, converted to a TCHAR, into val.  If elide is true,
 * also overwrites var and its value in the file with all lines subsequent,
 * allowing for a simple append to change the value (the file must have been
 * opened with both read and write access).
 */
static bool
read_config_ex(FILE *f, const char *var, TCHAR *val, size_t val_len, bool elide)
{
    bool found = false;
    /* FIXME: share code w/ core/config.c */
#    define BUFSIZE (MAX_CONFIG_VALUE + 128)
    char line[BUFSIZE];
    size_t var_len = strlen(var);
    /* Offsets into the file for the start and end of var. */
    size_t var_start = 0;
    size_t var_end = 0;
    /* each time we start from beginning: we assume a small file */
    if (f == NULL)
        return false;
    if (fseek(f, 0, SEEK_SET))
        return false;
    while (fgets(line, BUFFER_SIZE_ELEMENTS(line), f) != NULL) {
        fflush(stdout);
        /* Find lines starting with VAR=. */
        if (strncmp(line, var, var_len) == 0 && line[var_len] == '=') {
            found = true;
            var_end = var_start + strlen(line);
            if (val != NULL) {
                convert_to_tchar(val, line + var_len + 1, val_len);
                val[val_len - 1] = _T('\0');
                trim_trailing_newline(val);
            }
            break;
        }
        var_start += strlen(line);
        fflush(stdout);
    }

    /* If elide is true, seek back to the line, delete it, and shift the rest of
     * the file backward.  It's easier to do this with a fixed size buffer than
     * it is to it line-by-line with fgets/fputs.
     */
    if (found && elide) {
        /* Use long instead of ssize_t to match FILE* API. */
        long write_cur = (long)var_start;
        long read_cur = (long)var_end;
        long bufread;
        fflush(stdout);
        while (true) {
            fseek(f, read_cur, SEEK_SET);
            bufread = (long)fread(line, 1, BUFFER_SIZE_ELEMENTS(line), f);
            DO_ASSERT(ferror(f) == 0);
            line[bufread] = '\0';
            fflush(stdout);
            fseek(f, write_cur, SEEK_SET);
            if (bufread > 0) {
                fwrite(line, 1, bufread, f);
                DO_ASSERT(ferror(f) == 0);
                read_cur += bufread;
                write_cur += bufread;
            } else {
                break;
            }
        }
#    ifdef WINDOWS
        /* XXX: Can't find a way to truncate the file at the current position
         * using the FILE API.
         */
        SetEndOfFile((HANDLE)_get_osfhandle(_fileno(f)));
#    else
        {
            int r;
            off_t pos = lseek(fileno(f), 0, SEEK_CUR);
            if (pos == -1)
                return false;
            r = ftruncate(fileno(f), (off_t)pos);
            if (r != 0)
                return false;
        }
#    endif
    }

    return found;
}

/* for simplest coexistence with PARAMS_IN_REGISTRY taking in TCHAR and
 * converting to char.  not very efficient though.
 */
static dr_config_status_t
write_config_param(FILE *f, const char *var, const TCHAR *val)
{
    size_t written;
    int len;
    char buf[MAX_CONFIG_VALUE];
    DO_ASSERT(f != NULL);
    len = _snprintf(buf, BUFFER_SIZE_ELEMENTS(buf), "%s=" TSTR_FMT "\n", var, val);
    /* don't remove the newline: better to truncate options than to have none (i#547) */
    buf[BUFFER_SIZE_ELEMENTS(buf) - 2] = '\n';
    buf[BUFFER_SIZE_ELEMENTS(buf) - 1] = '\0';
    written = fwrite(buf, 1, strlen(buf), f);
    DO_ASSERT(written == strlen(buf));
    if (len < 0)
        return DR_CONFIG_STRING_TOO_LONG;
    if (written != strlen(buf))
        return DR_CONFIG_FILE_WRITE_FAILED;
    return DR_SUCCESS;
}

static bool
read_config_param(FILE *f, const char *var, TCHAR *val, size_t val_len)
{
    return read_config_ex(f, var, val, val_len, false);
}

#else /* !PARAMS_IN_REGISTRY */

static dr_config_status_t
write_config_param(ConfigGroup *policy, const TCHAR *var, const TCHAR *val)
{
    set_config_group_parameter(policy, var, val);
    return DR_SUCCESS;
}

static bool
read_config_param(FILE *f, const char *var, const TCHAR *val, size_t val_len)
{
    TCHAR *ptr = get_config_group_parameter(proc_policy, L_DYNAMORIO_VAR_OPTIONS);
    if (ptr == NULL)
        return false;
    _sntprintf(val, val_len, _TEXT("%s"), ptr);
    return true;
}

#endif /* PARAMS_IN_REGISTRY */

/***************************************************************************/

/* Read a DYNAMORIO_OPTIONS string from 'wbuf' and populate an opt_info_t struct */
static dr_config_status_t
read_options(opt_info_t *opt_info, IF_REG_ELSE(ConfigGroup *proc_policy, FILE *f))
{
    TCHAR buf[MAX_CONFIG_VALUE];
    TCHAR *ptr, token[DR_MAX_OPTIONS_LENGTH], tmp[DR_MAX_OPTIONS_LENGTH];
    opt_info_t null_opt_info = {
        0,
    };
    size_t len;

    *opt_info = null_opt_info;

    if (!read_config_param(IF_REG_ELSE(proc_policy, f), PARAM_STR(DYNAMORIO_VAR_OPTIONS),
                           buf, BUFFER_SIZE_ELEMENTS(buf)))
        return DR_FAILURE;
    ptr = buf;

    /* We'll be safe and not trust that get_config_group_parameter
     * returns a nice NULL-terminated string with no more than
     * DR_MAX_OPTIONS_LENGTH characters.  Making sure we have such a
     * string makes get_next_token() simpler.  A more efficient
     * approach would be to keep track of a string length and pass
     * that to get_next_token().
     */
    len = MIN(DR_MAX_OPTIONS_LENGTH - 1, _tcslen(ptr));
    _tcsncpy(tmp, ptr, len);
    tmp[len] = _T('\0');

    opt_info->mode = DR_MODE_NONE;

    ptr = tmp;
    while (ptr != NULL) {
        ptr = get_next_token(ptr, token);

        /*
         * look for the mode
         */
        if (_tcscmp(token, _TEXT("-code_api")) == 0) {
            if (opt_info->mode != DR_MODE_NONE &&
                /* allow dup options (i#1448) */
                opt_info->mode != DR_MODE_CODE_MANIPULATION) {
                goto error;
            }
            opt_info->mode = DR_MODE_CODE_MANIPULATION;
        }
#ifdef MF_API
        else if (_tcscmp(token, _TEXT("-security_api")) == 0) {
            if (opt_info->mode != DR_MODE_NONE &&
                opt_info->mode != DR_MODE_MEMORY_FIREWALL) {
                goto error;
            }
            opt_info->mode = DR_MODE_MEMORY_FIREWALL;
        }
#endif
        else if (_tcscmp(token, _TEXT("-probe_api")) == 0) {
#ifdef PROBE_API
            /* nothing; we assign the mode when we see -code_api */
#else
            /* we shouldn't see -probe_api */
            goto error;
#endif
        }
#ifdef PROBE_API
        else if (_tcscmp(token, _TEXT("-hotp_only")) == 0) {
            if (opt_info->mode != DR_MODE_NONE && opt_info->mode != DR_MODE_PROBE) {
                goto error;
            }
            opt_info->mode = DR_MODE_PROBE;
        }
#endif

        /*
         * look for client options
         */
        else if (_tcscmp(token, _TEXT("-client_lib")) == 0 ||
                 _tcscmp(token, _TEXT("-client_lib32")) == 0 ||
                 _tcscmp(token, _TEXT("-client_lib64")) == 0) {
            bool alt_bitwidth =
                _tcscmp(token,
                        IF_X64_ELSE(_TEXT("-client_lib32"), _TEXT("-client_lib64"))) == 0;
            TCHAR *path_str, *id_str, *opt_str;
            client_id_t id;

            ptr = get_next_token(ptr, token);
            if (ptr == NULL) {
                goto error;
            }

            /* handle enclosing quotes */
            path_str = token;
            if (path_str[0] == _T('\"') || path_str[0] == _T('\'') ||
                path_str[0] == _T('`')) {
                TCHAR quote = path_str[0];
                size_t last;

                path_str++;
                last = _tcslen(path_str) - 1;
                if (path_str[last] != quote) {
                    goto error;
                }
                path_str[last] = _T('\0');
            }

            /* -client_lib options should have the form path;ID;options.
             * Client priority is left-to-right.
             */
            id_str = _tcsstr(path_str, _TEXT(";"));
            if (id_str == NULL) {
                goto error;
            }

            *id_str = _T('\0');
            id_str++;

            opt_str = _tcsstr(id_str, _TEXT(";"));
            if (opt_str == NULL) {
                goto error;
            }

            *opt_str = _T('\0');
            opt_str++;

            /* client IDs are in hex */
            id = _tcstoul(id_str, NULL, 16);

            /* add the client info to our opt_info structure */
            if (add_client_lib(opt_info, id, opt_info->num_clients, path_str, opt_str,
                               alt_bitwidth) != DR_SUCCESS) {
                goto error;
            }
        }

        /*
         * Any remaining options are not related to clients.  Put all
         * these options (and their arguments) in one array.
         */
        else {
            if (add_extra_option(opt_info, token) != DR_SUCCESS) {
                goto error;
            }
        }
    }

    fflush(stdout);

    return DR_SUCCESS;

error:
    free_opt_info(opt_info);
    *opt_info = null_opt_info;
    return DR_FAILURE;
}

/* Write the options stored in an opt_info_t to 'wbuf' in the form expected
 * by the DYNAMORIO_OPTIONS registry entry.
 */
static dr_config_status_t
write_options(opt_info_t *opt_info, TCHAR *wbuf)
{
    size_t i;
    const char *mode_str = "";
    ssize_t len;
    ssize_t sofar = 0;
    ssize_t bufsz = DR_MAX_OPTIONS_LENGTH;

    /* NOTE - mode_str must come first since we want to give
     * client-supplied options the chance to override (for
     * ex. -stack_size which -code_api sets, see PR 247436
     */
    switch (opt_info->mode) {
#ifdef MF_API
    case DR_MODE_MEMORY_FIREWALL: mode_str = "-security_api"; break;
#endif
    case DR_MODE_CODE_MANIPULATION:
#ifdef PROBE_API
        mode_str = "-code_api -probe_api";
#else
        mode_str = "-code_api";
#endif
        break;
#ifdef PROBE_API
    case DR_MODE_PROBE: mode_str = "-probe_api -hotp_only"; break;
#endif
    case DR_MODE_DO_NOT_RUN:
        /* this is a mode b/c can't add dr_register_process param w/o breaking
         * backward compat, so just ignore in terms of options, user has to
         * re-reg anyway to re-enable and can specify mode then.
         */
        mode_str = "";
        break;
    default: DO_ASSERT(false);
    }

    len = _sntprintf(wbuf + sofar, bufsz - sofar, _TEXT(TSTR_FMT), mode_str);
    if (len >= 0 && len <= bufsz - sofar)
        sofar += len;

    /* extra options */
    for (i = 0; i < opt_info->num_extra_opts; i++) {
        /* FIXME: Note that we're blindly allowing any options
         * provided so we can allow users to specify "undocumented"
         * options.  Maybe we should be checking that the options are
         * actually valid?
         */
        len = _sntprintf(wbuf + sofar, bufsz - sofar, _TEXT(" %s"),
                         opt_info->extra_opts[i]);
        if (len >= 0 && len <= bufsz - sofar)
            sofar += len;
    }

    /* client lib options */
    for (i = 0; i < opt_info->num_clients; i++) {
        client_opt_t *client_opts = opt_info->client_opts[i];
        /* i#1542: pick a delimiter that avoids conflicts w/ the client strings */
        char delim = '\"';
        if (strchr(client_opts->path, delim) || strchr(client_opts->opts, delim)) {
            delim = '\'';
            if (strchr(client_opts->path, delim) || strchr(client_opts->opts, delim)) {
                delim = '`';
                if (strchr(client_opts->path, delim) ||
                    strchr(client_opts->opts, delim)) {
                    return DR_CONFIG_OPTIONS_INVALID;
                }
            }
        }
        /* no ; allowed */
        if (strchr(client_opts->path, ';') || strchr(client_opts->opts, ';'))
            return DR_CONFIG_OPTIONS_INVALID;
        len = _sntprintf(
            wbuf + sofar, bufsz - sofar,
            client_opts->alt_bitwidth ? IF_X64_ELSE(_TEXT(" -client_lib32 %c%s;%x;%s%c"),
                                                    _TEXT(" -client_lib64 %c%s;%x;%s%c"))
                                      : IF_X64_ELSE(_TEXT(" -client_lib64 %c%s;%x;%s%c"),
                                                    _TEXT(" -client_lib32 %c%s;%x;%s%c")),
            delim, client_opts->path, client_opts->id, client_opts->opts, delim);
        if (len >= 0 && len <= bufsz - sofar)
            sofar += len;
    }

    wbuf[DR_MAX_OPTIONS_LENGTH - 1] = _T('\0');
    return DR_SUCCESS;
}

#ifdef PARAMS_IN_REGISTRY
/* caller must call free_config_group() on the returned ConfigGroup */
static ConfigGroup *
get_policy(dr_platform_t dr_platform)
{
    ConfigGroup *policy;

    /* PR 244206: set the registry view before any registry access.
     * If we are ever part of a persistent agent maybe we should
     * restore to the default platform at the end of this routine?
     */
    set_dr_platform(dr_platform);

    if (read_config_group(&policy, L_PRODUCT_NAME, TRUE) != ERROR_SUCCESS) {
        return NULL;
    }

    return policy;
}

/* As a sub policy only the parent policy (from get_policy()) need be freed */
static ConfigGroup *
get_proc_policy(ConfigGroup *policy, const char *process_name)
{
    ConfigGroup *res = NULL;
    if (policy != NULL) {
        TCHAR wbuf[MAXIMUM_PATH];
        convert_to_tchar(wbuf, process_name, MAXIMUM_PATH);
        NULL_TERMINATE_BUFFER(wbuf);
        res = get_child(wbuf, policy);
    }
    return res;
}
#endif /* PARAMS_IN_REGISTRY */

static bool
platform_is_64bit(dr_platform_t platform)
{
    return (platform == DR_PLATFORM_64BIT IF_X64(|| platform == DR_PLATFORM_DEFAULT));
}

/* FIXME i#840: Syswide NYI for Linux. */
#ifdef WINDOWS
static void
get_syswide_path(TCHAR *wbuf, const char *dr_root_dir)
{
    TCHAR path[MAXIMUM_PATH];
    int len;
    if (!platform_is_64bit(get_dr_platform()))
        _sntprintf(path, MAXIMUM_PATH, _TEXT("%S") PREINJECT32_DLL, dr_root_dir);
    else
        _sntprintf(path, MAXIMUM_PATH, _TEXT("%S") PREINJECT64_DLL, dr_root_dir);
    path[MAXIMUM_PATH - 1] = '\0';
    /* spaces are separator in AppInit so use short path */
    len = GetShortPathName(path, wbuf, MAXIMUM_PATH);
    DO_ASSERT(len > 0);
    wbuf[MAXIMUM_PATH - 1] = _T('\0');
}

dr_config_status_t
dr_register_syswide(dr_platform_t dr_platform, const char *dr_root_dir)
{
    TCHAR wbuf[MAXIMUM_PATH];
    set_dr_platform(dr_platform);
    /* Set the appinit key */
    get_syswide_path(wbuf, dr_root_dir);
    /* Always overwrite, in case we have an older drpreinject version in there */
    if (set_custom_autoinjection(wbuf, APPINIT_OVERWRITE) != ERROR_SUCCESS ||
        (is_vista() && set_loadappinit() != ERROR_SUCCESS)) {
        return DR_FAILURE;
    }
    return DR_SUCCESS;
}

dr_config_status_t
dr_unregister_syswide(dr_platform_t dr_platform, const char *dr_root_dir)
{
    TCHAR wbuf[MAXIMUM_PATH];
    set_dr_platform(dr_platform);
    /* Set the appinit key */
    get_syswide_path(wbuf, dr_root_dir);
    if (unset_custom_autoinjection(wbuf, APPINIT_OVERWRITE) != ERROR_SUCCESS)
        return DR_FAILURE;
    /* We leave Vista loadappinit on */
    return DR_SUCCESS;
}

bool
dr_syswide_is_on(dr_platform_t dr_platform, const char *dr_root_dir)
{
    TCHAR wbuf[MAXIMUM_PATH];
    set_dr_platform(dr_platform);
    /* Set the appinit key */
    get_syswide_path(wbuf, dr_root_dir);
    return CAST_TO_bool(is_custom_autoinjection_set(wbuf));
}
#endif /* WINDOWS */

dr_config_status_t
dr_register_process(const char *process_name, process_id_t pid, bool global,
                    const char *dr_root_dir, dr_operation_mode_t dr_mode, bool debug,
                    dr_platform_t dr_platform, const char *dr_options)
{
#ifdef PARAMS_IN_REGISTRY
    ConfigGroup *policy, *proc_policy;
#else
    FILE *f;
#endif
    TCHAR wbuf[MAX(MAXIMUM_PATH, DR_MAX_OPTIONS_LENGTH)];
    IF_WINDOWS(DWORD platform;)
    opt_info_t opt_info = {
        0,
    };
    dr_config_status_t status;

#ifdef PARAMS_IN_REGISTRY
    /* PR 244206: set the registry view before any registry access.
     * If we are ever part of a persistent agent maybe we should
     * restore to the default platform at the end of this routine?
     */
    set_dr_platform(dr_platform);

    /* create top-level Determina/SecureCore key */
    if (create_root_key() != ERROR_SUCCESS) {
        return DR_FAILURE;
    }
    if (read_config_group(&policy, L_PRODUCT_NAME, TRUE) != ERROR_SUCCESS) {
        return DR_FAILURE;
    }

    /* create process key */
    convert_to_tchar(wbuf, process_name, MAXIMUM_PATH);
    NULL_TERMINATE_BUFFER(wbuf);
    proc_policy = get_child(wbuf, policy);
    if (proc_policy == NULL) {
        proc_policy = new_config_group(wbuf);
        add_config_group(policy, proc_policy);
    } else {
        return DR_PROC_REG_EXISTS;
    }
#else
    f = open_config_file(process_name, pid, global, dr_platform, false /*!read*/,
                         true /*write*/, pid != 0 /*overwrite for pid-specific*/);
    if (f == NULL) {
#    ifdef WINDOWS
        int err = GetLastError();
        if (err == ERROR_ALREADY_EXISTS)
            return DR_PROC_REG_EXISTS;
        else
#    endif
            return DR_CONFIG_DIR_NOT_FOUND;
    }
#endif

    /* set the rununder string */
    _sntprintf(wbuf, MAXIMUM_PATH,
               (dr_mode == DR_MODE_DO_NOT_RUN) ? _TEXT("0") : _TEXT("1"));
    NULL_TERMINATE_BUFFER(wbuf);
    status = write_config_param(IF_REG_ELSE(proc_policy, f),
                                PARAM_STR(DYNAMORIO_VAR_RUNUNDER), wbuf);
    DO_ASSERT(status == DR_SUCCESS);
    if (status != DR_SUCCESS)
        return status;

    /* set the autoinject string (i.e., path to dynamorio.dll */
    if (debug) {
        if (!platform_is_64bit(dr_platform))
            _sntprintf(wbuf, MAXIMUM_PATH, _TEXT(TSTR_FMT) DEBUG32_DLL, dr_root_dir);
        else
            _sntprintf(wbuf, MAXIMUM_PATH, _TEXT(TSTR_FMT) DEBUG64_DLL, dr_root_dir);
    } else {
        if (!platform_is_64bit(dr_platform))
            _sntprintf(wbuf, MAXIMUM_PATH, _TEXT(TSTR_FMT) RELEASE32_DLL, dr_root_dir);
        else
            _sntprintf(wbuf, MAXIMUM_PATH, _TEXT(TSTR_FMT) RELEASE64_DLL, dr_root_dir);
    }
    NULL_TERMINATE_BUFFER(wbuf);
    status = write_config_param(IF_REG_ELSE(proc_policy, f),
                                PARAM_STR(DYNAMORIO_VAR_AUTOINJECT), wbuf);
    DO_ASSERT(status == DR_SUCCESS);
    if (status != DR_SUCCESS)
        return status;

    /* set the logdir string */
    /* XXX i#886: should we expose this in the dr_register_process() params (and
     * thus dr_process_is_registered() and dr_registered_process_iterator_next())?
     * We now have a -logdir runtime option so we don't need to expose it for full
     * functionality anymore but it would serve to reduce the length of option
     * strings to have more control over the default.  Linux dr{config,run} does
     * allow such control today.
     */
    _sntprintf(wbuf, MAXIMUM_PATH, _TEXT(TSTR_FMT) LOG_SUBDIR, dr_root_dir);
    NULL_TERMINATE_BUFFER(wbuf);
    status = write_config_param(IF_REG_ELSE(proc_policy, f),
                                PARAM_STR(DYNAMORIO_VAR_LOGDIR), wbuf);
    DO_ASSERT(status == DR_SUCCESS);
    if (status != DR_SUCCESS)
        return status;

    /* set the options string last for faster updating w/ config files */
    opt_info.mode = dr_mode;
    add_extra_option_char(&opt_info, dr_options);
    status = write_options(&opt_info, wbuf);
    if (status != DR_SUCCESS)
        return status;
    status = write_config_param(IF_REG_ELSE(proc_policy, f),
                                PARAM_STR(DYNAMORIO_VAR_OPTIONS), wbuf);
    free_opt_info(&opt_info);
    DO_ASSERT(status == DR_SUCCESS);
    if (status != DR_SUCCESS)
        return status;

#ifdef PARAMS_IN_REGISTRY
    /* write the registry */
    if (write_config_group(policy) != ERROR_SUCCESS) {
        DO_ASSERT(false);
        return DR_FAILURE;
    }
#else
    fclose(f);
#endif

#ifdef WINDOWS
    /* If on win2k, copy drearlyhelper?.dll to system32
     * FIXME: this requires admin privs!  oh well: only issue is early inject
     * on win2k...
     */
    if (get_platform(&platform) == ERROR_SUCCESS && platform == PLATFORM_WIN_2000) {
        _sntprintf(wbuf, MAXIMUM_PATH, _TEXT(TSTR_FMT) LIB32_SUBDIR, dr_root_dir);
        NULL_TERMINATE_BUFFER(wbuf);
        copy_earlyhelper_dlls(wbuf);
    }
#endif

    return DR_SUCCESS;
}

dr_config_status_t
dr_unregister_process(const char *process_name, process_id_t pid, bool global,
                      dr_platform_t dr_platform)
{
#ifndef PARAMS_IN_REGISTRY
    char fname[MAXIMUM_PATH];
    if (get_config_file_name(process_name, pid, global, dr_platform, fname,
                             BUFFER_SIZE_ELEMENTS(fname))) {
        TCHAR wbuf[MAXIMUM_PATH];
        convert_to_tchar(wbuf, fname, BUFFER_SIZE_ELEMENTS(wbuf));
        NULL_TERMINATE_BUFFER(wbuf);
        if (!file_exists(wbuf))
            return DR_PROC_REG_INVALID;
        if (_wremove(wbuf) == 0)
            return DR_SUCCESS;
    }
    return DR_FAILURE;
#else
    ConfigGroup *policy = get_policy(dr_platform);
    ConfigGroup *proc_policy = get_proc_policy(policy, process_name);
    TCHAR wbuf[MAXIMUM_PATH];
    dr_config_status_t status = DR_SUCCESS;

    if (proc_policy == NULL) {
        status = DR_PROC_REG_INVALID;
        goto exit;
    }

    /* remove it */
    convert_to_tchar(wbuf, process_name, BUFFER_SIZE_ELEMENTS(wbuf));
    NULL_TERMINATE_BUFFER(wbuf);
    remove_child(wbuf, policy);
    policy->should_clear = TRUE;

    /* write the registry */
    if (write_config_group(policy) != ERROR_SUCCESS) {
        status = DR_FAILURE;
        goto exit;
    }

    /* FIXME PR 232738: we should remove the drdearlyhelp?.dlls and preinject
     * from system32, and remove the base reg keys, if dr_unregister_process()
     * removes the last registered process.
     */

exit:
    if (policy != NULL)
        free_config_group(policy);
    return status;
#endif
}

/* For !PARAMS_IN_REGISTRY, process_name is NOT filled in! */
static void
read_process_policy(IF_REG_ELSE(ConfigGroup *proc_policy, FILE *f),
                    char *process_name /* OUT */, char *dr_root_dir /* OUT */,
                    dr_operation_mode_t *dr_mode /* OUT */, bool *debug /* OUT */,
                    char *dr_options /* OUT */)
{
    TCHAR autoinject[MAX_CONFIG_VALUE];
    opt_info_t opt_info;

    if (dr_mode != NULL)
        *dr_mode = DR_MODE_NONE;
    if (dr_root_dir != NULL)
        *dr_root_dir = '\0';
    if (dr_options != NULL)
        *dr_options = '\0';

#ifdef PARAMS_IN_REGISTRY
    if (process_name != NULL)
        *process_name = '\0';
    if (process_name != NULL && proc_policy->name != NULL) {
        copy_up_to_max(process_name, MAXIMUM_PATH, proc_policy->name);
    }
#else
        /* up to caller to fill in! */
#endif

    if (dr_root_dir != NULL &&
        read_config_param(IF_REG_ELSE(proc_policy, f),
                          PARAM_STR(DYNAMORIO_VAR_AUTOINJECT), autoinject,
                          BUFFER_SIZE_ELEMENTS(autoinject))) {
        TCHAR *vers = _tcsstr(autoinject, RELEASE32_DLL);
        if (vers == NULL) {
            vers = _tcsstr(autoinject, DEBUG32_DLL);
        }
        if (vers == NULL) {
            vers = _tcsstr(autoinject, RELEASE64_DLL);
        }
        if (vers == NULL) {
            vers = _tcsstr(autoinject, DEBUG64_DLL);
        }
        if (vers != NULL) {
            size_t len = MIN(MAXIMUM_PATH - 1, vers - autoinject);
            _snprintf(dr_root_dir, len, TSTR_FMT, autoinject);
            dr_root_dir[len] = '\0';
        } else {
            dr_root_dir[0] = '\0';
        }
    }

    if (read_options(&opt_info, IF_REG_ELSE(proc_policy, f)) != DR_SUCCESS) {
        /* note: read_options() frees any memory it allocates if it fails */
        return;
    }

    if (debug != NULL) {
        if (_tcsstr(autoinject, DEBUG32_DLL) != NULL ||
            _tcsstr(autoinject, DEBUG64_DLL) != NULL) {
            *debug = true;
        } else {
            *debug = false;
        }
    }

    if (dr_mode != NULL) {
        *dr_mode = opt_info.mode;
        if (read_config_param(IF_REG_ELSE(proc_policy, f),
                              PARAM_STR(DYNAMORIO_VAR_RUNUNDER), autoinject,
                              BUFFER_SIZE_ELEMENTS(autoinject))) {
            if (_tcscmp(autoinject, _TEXT("0")) == 0)
                *dr_mode = DR_MODE_DO_NOT_RUN;
        }
    }

    if (dr_options != NULL) {
        uint i;
        size_t len_remain = DR_MAX_OPTIONS_LENGTH - 1, cur_off = 0;
        dr_options[0] = '\0';
        for (i = 0; i < opt_info.num_extra_opts; i++) {
            size_t len;
            if (i > 0 && len_remain > 0) {
                len_remain--;
                dr_options[cur_off++] = ' ';
            }
            len = MIN(len_remain, _tcslen(opt_info.extra_opts[i]));
            _snprintf(dr_options + cur_off, len, TSTR_FMT, opt_info.extra_opts[i]);
            cur_off += len;
            len_remain -= len;
            dr_options[cur_off] = '\0';
        }
    }

    free_opt_info(&opt_info);
}

/* FIXME i#840: NYI for Linux, need a FindFirstFile equivalent. */
#ifdef WINDOWS

struct _dr_registered_process_iterator_t {
#    ifdef PARAMS_IN_REGISTRY
    ConfigGroup *policy;
    ConfigGroup *cur;
#    else
    bool has_next;
    HANDLE find_handle;
    /* because UNICODE is defined we have to use the wide version of
     * FindFirstFile and convert back and forth
     */
    WIN32_FIND_DATA find_data;
    /* FindFirstFile only fills in the basename */
    TCHAR wdir[MAXIMUM_PATH];
    TCHAR wfname[MAXIMUM_PATH];
#    endif
};

dr_registered_process_iterator_t *
dr_registered_process_iterator_start(dr_platform_t dr_platform, bool global)
{
    dr_registered_process_iterator_t *iter = (dr_registered_process_iterator_t *)malloc(
        sizeof(dr_registered_process_iterator_t));
#    ifdef PARAMS_IN_REGISTRY
    iter->policy = get_policy(dr_platform);
    if (iter->policy != NULL)
        iter->cur = iter->policy->children;
    else
        iter->cur = NULL;
#    else
    char dir[MAXIMUM_PATH];
    if (!get_config_dir(global, dir, BUFFER_SIZE_ELEMENTS(dir), false)) {
        iter->has_next = false;
        iter->find_handle = INVALID_HANDLE_VALUE;
        return iter;
    }
    convert_to_tchar(iter->wdir, dir, BUFFER_SIZE_ELEMENTS(iter->wdir));
    NULL_TERMINATE_BUFFER(iter->wdir);
    _sntprintf(iter->wfname, BUFFER_SIZE_ELEMENTS(iter->wfname), _TEXT("%s/*.%S"),
               iter->wdir, get_config_sfx(dr_platform));
    NULL_TERMINATE_BUFFER(iter->wfname);
    iter->find_handle = FindFirstFile(iter->wfname, &iter->find_data);
    iter->has_next = (iter->find_handle != INVALID_HANDLE_VALUE);
#    endif
    return iter;
}

bool
dr_registered_process_iterator_hasnext(dr_registered_process_iterator_t *iter)
{
#    ifdef PARAMS_IN_REGISTRY
    return iter->policy != NULL && iter->cur != NULL;
#    else
    return iter->has_next;
#    endif
}

bool
dr_registered_process_iterator_next(dr_registered_process_iterator_t *iter,
                                    char *process_name /* OUT */,
                                    char *dr_root_dir /* OUT */,
                                    dr_operation_mode_t *dr_mode /* OUT */,
                                    bool *debug /* OUT */, char *dr_options /* OUT */)
{
#    ifdef PARAMS_IN_REGISTRY
    read_process_policy(iter->cur, process_name, dr_root_dir, dr_mode, debug, dr_options);
    iter->cur = iter->cur->next;
    return true;
#    else
    bool ok = true;
    FILE *f;
    _sntprintf(iter->wfname, BUFFER_SIZE_ELEMENTS(iter->wfname), _TEXT("%s/%s"),
               iter->wdir, iter->find_data.cFileName);
    NULL_TERMINATE_BUFFER(iter->wfname);
    f = _wfopen(iter->wfname, L"r");
    if (process_name != NULL) {
        TCHAR *end;
        end = _tcsstr(iter->find_data.cFileName, _TEXT(".config"));
        if (end == NULL) {
            process_name[0] = '\0';
            ok = false;
        } else {
#        ifdef UNICODE
            _snprintf(process_name, end - iter->find_data.cFileName, "%S",
                      iter->find_data.cFileName);
#        else
            _snprintf(process_name, end - iter->find_data.cFileName, "%s",
                      iter->find_data.cFileName);
#        endif
        }
    }
    if (!FindNextFile(iter->find_handle, &iter->find_data))
        iter->has_next = false;
    if (f == NULL || !ok) {
        if (f != NULL)
            fclose(f);
        return false;
    }
    read_process_policy(f, process_name, dr_root_dir, dr_mode, debug, dr_options);
    fclose(f);
    return true;
#    endif
}

void
dr_registered_process_iterator_stop(dr_registered_process_iterator_t *iter)
{
#    ifdef PARAMS_IN_REGISTRY
    if (iter->policy != NULL)
        free_config_group(iter->policy);
#    else
    if (iter->find_handle != INVALID_HANDLE_VALUE)
        FindClose(iter->find_handle);
#    endif
    free(iter);
}

#endif /* WINDOWS */

dr_config_status_t
dr_register_inject_paths(const char *process_name, process_id_t pid, bool global,
                         dr_platform_t dr_platform, const char *dr_lib_path,
                         const char *dr_alt_lib_path)
{
#ifdef PARAMS_IN_REGISTRY
    ConfigGroup *policy = get_policy(dr_platform);
    ConfigGroup *proc_policy = get_proc_policy(policy, process_name);
#else
    FILE *f = open_config_file(process_name, pid, global, dr_platform, true /*read*/,
                               true /*write*/, false /*!overwrite*/);
#endif
    dr_config_status_t status = DR_SUCCESS;
    TCHAR wpath[MAXIMUM_PATH];
    if (IF_REG_ELSE(proc_policy == NULL, f == NULL)) {
        status = DR_PROC_REG_INVALID;
        goto exit;
    }
    if (dr_lib_path == NULL) {
        status = DR_CONFIG_INVALID_PARAMETER;
        goto exit;
    }
#ifndef PARAMS_IN_REGISTRY
    /* shift rest of file up, overwriting old value, so we can append new value */
    read_config_ex(f, DYNAMORIO_VAR_AUTOINJECT, NULL, 0, true);
#endif
    convert_to_tchar(wpath, dr_lib_path, MAXIMUM_PATH);
    NULL_TERMINATE_BUFFER(wpath);
    status = write_config_param(IF_REG_ELSE(proc_policy, f),
                                PARAM_STR(DYNAMORIO_VAR_AUTOINJECT), wpath);
    if (status != DR_SUCCESS)
        return status;

    if (dr_alt_lib_path != NULL) {
#ifndef PARAMS_IN_REGISTRY
        /* shift rest of file up, overwriting old value, so we can append new value */
        read_config_ex(f, DYNAMORIO_VAR_ALTINJECT, NULL, 0, true);
#endif
        convert_to_tchar(wpath, dr_alt_lib_path, MAXIMUM_PATH);
        NULL_TERMINATE_BUFFER(wpath);
        status = write_config_param(IF_REG_ELSE(proc_policy, f),
                                    PARAM_STR(DYNAMORIO_VAR_ALTINJECT), wpath);
        if (status != DR_SUCCESS)
            return status;
    }

#ifdef PARAMS_IN_REGISTRY
    /* write the registry */
    if (write_config_group(policy) != ERROR_SUCCESS) {
        return DR_FAILURE;
    }
#endif

exit:
#ifdef PARAMS_IN_REGISTRY
    if (policy != NULL)
        free_config_group(policy);
#else
    if (f != NULL)
        fclose(f);
#endif
    return status;
}

bool
dr_process_is_registered(const char *process_name, process_id_t pid, bool global,
                         dr_platform_t dr_platform /* OUT */, char *dr_root_dir /* OUT */,
                         dr_operation_mode_t *dr_mode /* OUT */, bool *debug /* OUT */,
                         char *dr_options /* OUT */)
{
    bool result = false;
#ifdef PARAMS_IN_REGISTRY
    ConfigGroup *policy = get_policy(dr_platform);
    ConfigGroup *proc_policy = get_proc_policy(policy, process_name);
#else
    FILE *f = open_config_file(process_name, pid, global, dr_platform, true /*read*/,
                               false /*!write*/, false /*!overwrite*/);
#endif
    if (IF_REG_ELSE(proc_policy == NULL, f == NULL))
        goto exit;
    result = true;

    read_process_policy(IF_REG_ELSE(proc_policy, f), NULL, dr_root_dir, dr_mode, debug,
                        dr_options);

exit:
#ifdef PARAMS_IN_REGISTRY
    if (policy != NULL)
        free_config_group(policy);
#else
    if (f != NULL)
        fclose(f);
#endif
    return result;
}

struct _dr_client_iterator_t {
    opt_info_t opt_info;
    uint cur;
    bool valid;
};

dr_client_iterator_t *
dr_client_iterator_start(const char *process_name, process_id_t pid, bool global,
                         dr_platform_t dr_platform)
{
#ifdef PARAMS_IN_REGISTRY
    ConfigGroup *policy = get_policy(dr_platform);
    ConfigGroup *proc_policy = get_proc_policy(policy, process_name);
#else
    FILE *f = open_config_file(process_name, pid, global, dr_platform, true /*read*/,
                               false /*!write*/, false /*!overwrite*/);
#endif
    dr_client_iterator_t *iter =
        (dr_client_iterator_t *)malloc(sizeof(dr_client_iterator_t));

    iter->valid = false;
    iter->cur = 0;
    if (IF_REG_ELSE(proc_policy == NULL, f == NULL))
        return iter;
    if (read_options(&iter->opt_info, IF_REG_ELSE(proc_policy, f)) != DR_SUCCESS) {
#ifdef PARAMS_IN_REGISTRY
        if (policy != NULL)
            free_config_group(policy);
#else
        if (f != NULL)
            fclose(f);
#endif
        return iter;
    }
    iter->valid = true;
#ifdef PARAMS_IN_REGISTRY
    if (policy != NULL)
        free_config_group(policy);
#else
    if (f != NULL)
        fclose(f);
#endif
    return iter;
}

bool
dr_client_iterator_hasnext(dr_client_iterator_t *iter)
{
    return iter->valid && iter->cur < iter->opt_info.num_clients;
}

void
dr_client_iterator_next(dr_client_iterator_t *iter, client_id_t *client_id, /* OUT */
                        size_t *client_pri,                                 /* OUT */
                        char *client_path,                                  /* OUT */
                        char *client_options /* OUT */)
{
    client_opt_t *client_opt = iter->opt_info.client_opts[iter->cur];

    if (client_pri != NULL)
        *client_pri = iter->cur;

    if (client_path != NULL) {
        copy_up_to_max(client_path, MAXIMUM_PATH, client_opt->path);
    }

    if (client_id != NULL)
        *client_id = client_opt->id;

    if (client_options != NULL) {
        copy_up_to_max(client_options, DR_MAX_OPTIONS_LENGTH, client_opt->opts);
    }

    iter->cur++;
}

dr_config_status_t
dr_client_iterator_next_ex(dr_client_iterator_t *iter,
                           dr_config_client_t *client /* IN/OUT */)
{
    client_opt_t *client_opt = iter->opt_info.client_opts[iter->cur];
    if (client == NULL || client->struct_size != sizeof(dr_config_client_t))
        return DR_CONFIG_INVALID_PARAMETER;
    client->id = client_opt->id;
    client->priority = iter->cur;
    if (client->path != NULL) {
        copy_up_to_max(client->path, MAXIMUM_PATH, client_opt->path);
    }
    if (client->options != NULL) {
        copy_up_to_max(client->options, DR_MAX_OPTIONS_LENGTH, client_opt->opts);
    }
    client->is_alt_bitwidth = client_opt->alt_bitwidth;
    iter->cur++;
    return DR_SUCCESS;
}

void
dr_client_iterator_stop(dr_client_iterator_t *iter)
{
    if (iter->valid)
        free_opt_info(&iter->opt_info);
    free(iter);
}

size_t
dr_num_registered_clients(const char *process_name, process_id_t pid, bool global,
                          dr_platform_t dr_platform)
{
    opt_info_t opt_info;
    size_t num = 0;
#ifdef PARAMS_IN_REGISTRY
    ConfigGroup *policy = get_policy(dr_platform);
    ConfigGroup *proc_policy = get_proc_policy(policy, process_name);
#else
    FILE *f = open_config_file(process_name, pid, global, dr_platform, true /*read*/,
                               false /*!write*/, false /*!overwrite*/);
#endif
    if (IF_REG_ELSE(proc_policy == NULL, f == NULL))
        goto exit;

    if (read_options(&opt_info, IF_REG_ELSE(proc_policy, f)) != DR_SUCCESS)
        goto exit;

    num = opt_info.num_clients;
    free_opt_info(&opt_info);

exit:
#ifdef PARAMS_IN_REGISTRY
    if (policy != NULL)
        free_config_group(policy);
#else
    fclose(f);
#endif
    return num;
}

dr_config_status_t
dr_get_client_info_ex(const char *process_name, process_id_t pid, bool global,
                      dr_platform_t dr_platform, dr_config_client_t *client)
{
    if (client == NULL || client->struct_size != sizeof(*client))
        return DR_CONFIG_INVALID_PARAMETER;
    opt_info_t opt_info;
    dr_config_status_t status;
    size_t i;
#ifdef PARAMS_IN_REGISTRY
    ConfigGroup *policy = get_policy(dr_platform);
    ConfigGroup *proc_policy = get_proc_policy(policy, process_name);
#else
    FILE *f = open_config_file(process_name, pid, global, dr_platform, true /*read*/,
                               false /*!write*/, false /*!overwrite*/);
#endif
    if (IF_REG_ELSE(proc_policy == NULL, f == NULL)) {
        status = DR_PROC_REG_INVALID;
        goto exit;
    }

    status = read_options(&opt_info, IF_REG_ELSE(proc_policy, f));
    if (status != DR_SUCCESS)
        goto exit;

    for (i = 0; i < opt_info.num_clients; i++) {
        if (opt_info.client_opts[i]->id == client->id) {
            client_opt_t *client_opt = opt_info.client_opts[i];

            client->priority = i;
            if (client->path != NULL) {
                copy_up_to_max(client->path, MAXIMUM_PATH, client_opt->path);
            }

            if (client->options != NULL) {
                copy_up_to_max(client->options, DR_MAX_OPTIONS_LENGTH, client_opt->opts);
            }

            status = DR_SUCCESS;
            goto exit;
        }
    }

    status = DR_ID_INVALID;

exit:
#ifdef PARAMS_IN_REGISTRY
    if (policy != NULL)
        free_config_group(policy);
#else
    fclose(f);
#endif
    return status;
}

dr_config_status_t
dr_get_client_info(const char *process_name, process_id_t pid, bool global,
                   dr_platform_t dr_platform, client_id_t client_id, size_t *client_pri,
                   char *client_path, char *client_options)
{
    dr_config_client_t client;
    client.struct_size = sizeof(client);
    client.id = client_id;
    client.path = client_path;
    client.options = client_options;
    dr_config_status_t status =
        dr_get_client_info_ex(process_name, pid, global, dr_platform, &client);
    if (status == DR_SUCCESS && client_pri != NULL)
        *client_pri = client.priority;
    return status;
}

dr_config_status_t
dr_register_client_ex(const char *process_name, process_id_t pid, bool global,
                      dr_platform_t dr_platform, dr_config_client_t *client)
{
    if (client == NULL || client->struct_size != sizeof(*client))
        return DR_CONFIG_INVALID_PARAMETER;

    TCHAR new_opts[DR_MAX_OPTIONS_LENGTH];
    TCHAR wpath[MAXIMUM_PATH], woptions[DR_MAX_OPTIONS_LENGTH];
#ifdef PARAMS_IN_REGISTRY
    ConfigGroup *policy = get_policy(dr_platform);
    ConfigGroup *proc_policy = get_proc_policy(policy, process_name);
#else
    FILE *f = open_config_file(process_name, pid, global, dr_platform, true /*read*/,
                               true /*write*/, false /*!overwrite*/);
#endif
    dr_config_status_t status;
    opt_info_t opt_info;
    bool opt_info_alloc = false;
    size_t i;

    if (IF_REG_ELSE(proc_policy == NULL, f == NULL)) {
        status = DR_PROC_REG_INVALID;
        goto exit;
    }

    status = read_options(&opt_info, IF_REG_ELSE(proc_policy, f));
    if (status != DR_SUCCESS) {
        goto exit;
    }
    opt_info_alloc = true;

    bool order_ok = !client->is_alt_bitwidth;
    for (i = 0; i < opt_info.num_clients; i++) {
        if (opt_info.client_opts[i]->id == client->id) {
            if (!opt_info.client_opts[i]->alt_bitwidth && client->is_alt_bitwidth) {
                /* OK since this is the alt for an existing primary. */
                order_ok = true;
            } else {
                status = DR_ID_CONFLICTING;
                goto exit;
            }
        }
    }
    if (!order_ok) {
        status = DR_CONFIG_CLIENT_NOT_FOUND;
        goto exit;
    }

    if (client->priority > opt_info.num_clients) {
        status = DR_PRIORITY_INVALID;
        goto exit;
    }

    convert_to_tchar(wpath, client->path, MAXIMUM_PATH);
    NULL_TERMINATE_BUFFER(wpath);
    convert_to_tchar(woptions, client->options, DR_MAX_OPTIONS_LENGTH);
    NULL_TERMINATE_BUFFER(woptions);

    status = add_client_lib(&opt_info, client->id, client->priority, wpath, woptions,
                            client->is_alt_bitwidth);
    if (status != DR_SUCCESS) {
        goto exit;
    }

    /* write the registry */
    status = write_options(&opt_info, new_opts);
    if (status != DR_SUCCESS)
        goto exit;
#ifndef PARAMS_IN_REGISTRY
    /* shift rest of file up, overwriting old value, so we can append new value */
    read_config_ex(f, DYNAMORIO_VAR_OPTIONS, NULL, 0, true);
#endif
    status = write_config_param(IF_REG_ELSE(proc_policy, f),
                                PARAM_STR(DYNAMORIO_VAR_OPTIONS), new_opts);
    if (status != DR_SUCCESS)
        goto exit;

#ifdef PARAMS_IN_REGISTRY
    if (write_config_group(policy) != ERROR_SUCCESS) {
        status = DR_FAILURE;
        goto exit;
    }
#endif
    status = DR_SUCCESS;

exit:
#ifdef PARAMS_IN_REGISTRY
    if (policy != NULL)
        free_config_group(policy);
#else
    if (f != NULL)
        fclose(f);
#endif
    if (opt_info_alloc)
        free_opt_info(&opt_info);
    return status;
}

dr_config_status_t
dr_register_client(const char *process_name, process_id_t pid, bool global,
                   dr_platform_t dr_platform, client_id_t client_id, size_t client_pri,
                   const char *client_path, const char *client_options)
{
    dr_config_client_t client;
    client.struct_size = sizeof(client);
    client.id = client_id;
    client.priority = client_pri;
    client.path = (char *)client_path;
    client.options = (char *)client_options;
    client.is_alt_bitwidth = false;
    return dr_register_client_ex(process_name, pid, global, dr_platform, &client);
}

dr_config_status_t
dr_unregister_client(const char *process_name, process_id_t pid, bool global,
                     dr_platform_t dr_platform, client_id_t client_id)
{
    TCHAR new_opts[DR_MAX_OPTIONS_LENGTH];
#ifdef PARAMS_IN_REGISTRY
    ConfigGroup *policy = get_policy(dr_platform);
    ConfigGroup *proc_policy = get_proc_policy(policy, process_name);
#else
    FILE *f = open_config_file(process_name, pid, global, dr_platform, true /*read*/,
                               true /*write*/, false /*!overwrite*/);
#endif
    dr_config_status_t status;
    opt_info_t opt_info;
    bool opt_info_alloc = false;

    if (IF_REG_ELSE(proc_policy == NULL, f == NULL)) {
        status = DR_PROC_REG_INVALID;
        goto exit;
    }

    status = read_options(&opt_info, IF_REG_ELSE(proc_policy, f));
    if (status != DR_SUCCESS) {
        goto exit;
    }
    opt_info_alloc = true;

    status = remove_client_lib(&opt_info, client_id);
    if (status != DR_SUCCESS) {
        goto exit;
    }

    /* write the registry */
    write_options(&opt_info, new_opts);
#ifndef PARAMS_IN_REGISTRY
    /* shift rest of file up, overwriting old value, so we can append new value */
    read_config_ex(f, DYNAMORIO_VAR_OPTIONS, NULL, 0, true);
#endif
    write_config_param(IF_REG_ELSE(proc_policy, f), PARAM_STR(DYNAMORIO_VAR_OPTIONS),
                       new_opts);

#ifdef PARAMS_IN_REGISTRY
    if (write_config_group(policy) != ERROR_SUCCESS) {
        status = DR_FAILURE;
        goto exit;
    }
#endif

    status = DR_SUCCESS;

exit:
#ifdef PARAMS_IN_REGISTRY
    if (policy != NULL)
        free_config_group(policy);
#else
    if (f != NULL)
        fclose(f);
#endif
    if (opt_info_alloc)
        free_opt_info(&opt_info);
    return status;
}

#ifdef WINDOWS

typedef struct {
    const char *process_name; /* if non-null nudges processes with matching name */
    bool all;                 /* if set attempts to nudge all processes */
    client_id_t client_id;
    uint64 argument;
    int count;     /* number of nudges successfully delivered */
    DWORD res;     /* last failing error code */
    DWORD timeout; /* amount of time to wait for nudge to finish */
} pw_nudge_callback_data_t;

static BOOL
pw_nudge_callback(process_info_t *pi, void **param)
{
    char buf[MAXIMUM_PATH];
    pw_nudge_callback_data_t *data = (pw_nudge_callback_data_t *)param;

    if (pi->ProcessID == 0)
        return true; /* skip system process */

    buf[0] = '\0';
    if (pi->ProcessName != NULL)
        _snprintf(buf, MAXIMUM_PATH, "%S", pi->ProcessName);
    NULL_TERMINATE_BUFFER(buf);
    if (data->all ||
        (data->process_name != NULL &&
         strnicmp(data->process_name, buf, MAXIMUM_PATH) == 0)) {
        DWORD res = generic_nudge(pi->ProcessID, true, NUDGE_GENERIC(client),
                                  data->client_id, data->argument, data->timeout);
        if (res == ERROR_SUCCESS || res == ERROR_TIMEOUT) {
            data->count++;
            if (res == ERROR_TIMEOUT && data->timeout != 0)
                data->res = ERROR_TIMEOUT;
        } else if (res != ERROR_MOD_NOT_FOUND /* so failed for a good reason */)
            data->res = res;
    }

    return true;
}

/* TODO: must be careful in invoking the correct VIPA's nudge handler,
 * particularly a problem with multiple agents, but can be a problem even in a
 * single agent if some other dll exports dr_nudge_handler() (remote
 * contingency).
 */

dr_config_status_t
dr_nudge_process(const char *process_name, client_id_t client_id, uint64 arg,
                 uint timeout_ms, int *nudge_count /*OUT */)
{
    pw_nudge_callback_data_t data = { 0 };
    data.process_name = process_name;
    data.client_id = client_id;
    data.argument = arg;
    data.timeout = timeout_ms;
    data.res = ERROR_SUCCESS;
    process_walk(&pw_nudge_callback, (void **)&data);
    if (nudge_count != NULL)
        *nudge_count = data.count;

    if (data.res == ERROR_SUCCESS)
        return DR_SUCCESS;
    else if (data.res == ERROR_TIMEOUT)
        return DR_NUDGE_TIMEOUT;
    else
        return DR_FAILURE;
}

dr_config_status_t
dr_nudge_pid(process_id_t process_id, client_id_t client_id, uint64 arg, uint timeout_ms)
{
    DWORD res = generic_nudge(process_id, true, NUDGE_GENERIC(client), client_id, arg,
                              timeout_ms);

    if (res == ERROR_SUCCESS)
        return DR_SUCCESS;
    if (res == ERROR_MOD_NOT_FOUND)
        return DR_NUDGE_PID_NOT_INJECTED;
    if (res == ERROR_TIMEOUT && timeout_ms != 0)
        return DR_NUDGE_TIMEOUT;
    return DR_FAILURE;
}

dr_config_status_t
dr_nudge_all(client_id_t client_id, uint64 arg, uint timeout_ms, int *nudge_count /*OUT*/)
{
    pw_nudge_callback_data_t data = { 0 };
    data.all = true;
    data.client_id = client_id;
    data.argument = arg;
    data.timeout = timeout_ms;
    data.res = ERROR_SUCCESS;
    process_walk(&pw_nudge_callback, (void **)&data);
    if (nudge_count != NULL)
        *nudge_count = data.count;

    if (data.res == ERROR_SUCCESS)
        return DR_SUCCESS;
    if (data.res == ERROR_TIMEOUT)
        return DR_NUDGE_TIMEOUT;
    return DR_FAILURE;
}

#elif defined LINUX

dr_config_status_t
dr_nudge_pid(process_id_t process_id, client_id_t client_id, uint64 arg, uint timeout_ms)
{
    siginfo_t info;
    int res;
    /* construct the payload */
    if (!create_nudge_signal_payload(&info, NUDGE_GENERIC(client), 0, client_id, arg))
        return DR_FAILURE;
    /* send the nudge */
    res = syscall(SYS_rt_sigqueueinfo, process_id, NUDGESIG_SIGNUM, &info);
    if (res < 0)
        return DR_FAILURE;
    return DR_SUCCESS;
}

#endif /* WINDOWS */

/* XXX: perhaps we should take in a config dir as a parameter to all
 * of the registration routines in the drconfiglib API rather than or
 * in addition to having this env var DYNAMORIO_CONFIGLIB.
 * Xref i#939.
 */
dr_config_status_t
dr_get_config_dir(bool global, bool alternative_local, char *config_dir /* OUT */,
                  size_t config_dir_sz)
{
    if (get_config_dir(global, config_dir, config_dir_sz, alternative_local)) {
        /* XXX: it would be nice to return DR_CONFIG_STRING_TOO_LONG if the
         * buffer is too small, rather than just truncating it
         */
        return DR_SUCCESS;
    } else
        return DR_CONFIG_DIR_NOT_FOUND;
}