/* SPDX-License-Identifier: LGPL-2.1-or-later */

#include <stdio.h>

#include "alloc-util.h"

#include "conf-parser.h"

#include "escape.h"

#include "extract-word.h"

#include "fd-util.h"

#include "fileio.h"

#include "generator.h"

#include "glyph-util.h"

#include "log.h"

#include "parse-util.h"

#include "path-util.h"

#include "specifier.h"

#include "string-util.h"

#include "strv.h"

#include "unit-name.h"

#include "user-util.h"

#include "xdg-autostart-service.h"

XdgAutostartService* xdg_autostart_service_free(XdgAutostartService *s) {

        if (!s)

                return NULL;

        free(s->name);

        free(s->path);

        free(s->description);

        free(s->type);

        free(s->exec_string);

        free(s->working_directory);

        strv_free(s->only_show_in);

        strv_free(s->not_show_in);

        free(s->try_exec);

        free(s->autostart_condition);

        free(s->kde_autostart_condition);

        free(s->gnome_autostart_phase);

        return mfree(s);

}

char* xdg_autostart_service_translate_name(const char *name) {

        _cleanup_free_ char *c = NULL, *escaped = NULL;

        char *res;

        c = strdup(name);

        if (!c)

                return NULL;

        res = endswith(c, ".desktop");

        if (res)

                *res = '\0';

        escaped = unit_name_escape(c);

        if (!escaped)

                return NULL;

        return strjoin("app-", escaped, "@autostart.service");

}

static int xdg_config_parse_bool(

                const char *unit,

                const char *filename,

                unsigned line,

                const char *section,

                unsigned section_line,

                const char *lvalue,

                int ltype,

                const char *rvalue,

                void *data,

                void *userdata) {

        bool *b = ASSERT_PTR(data);

        int r;

        assert(filename);

        assert(lvalue);

        assert(rvalue);

        r = parse_boolean(rvalue);

        if (r < 0)

                return log_syntax(unit, LOG_ERR, filename, line, SYNTHETIC_ERRNO(EINVAL), "Invalid value for boolean: %s", rvalue);

        *b = r;

        return 0;

}

/* Unescapes the string in-place, returns non-zero status on error. */

static int xdg_unescape_string(

                const char *unit,

                const char *filename,

                int line,

                char *str) {

        char *in;

        char *out;

        assert(str);

        in = out = str;

        for (; *in; in++, out++) {

                if (*in == '\\') {

                        /* Move forward, and ensure it is a valid escape. */

                        in++;

                        switch (*in) {

                                case 's':

                                        *out = ' ';

                                        break;

                                case 'n':

                                        *out = '\n';

                                        break;

                                case 't':

                                        *out = '\t';

                                        break;

                                case 'r':

                                        *out = '\r';

                                        break;

                                case '\\':

                                        *out = '\\';

                                        break;

                                case ';':

                                        /* Technically only permitted for strv. */

                                        *out = ';';

                                        break;

                                default:

                                        return log_syntax(unit, LOG_ERR, filename, line, SYNTHETIC_ERRNO(EINVAL), "Undefined escape sequence \\%c.", *in);

                        }

                        continue;

                }

                *out = *in;

        }

        *out = '\0';

        return 0;

}

/* Note: We do not bother with unescaping the strings, hence the _raw postfix. */

static int xdg_config_parse_string(

                const char *unit,

                const char *filename,

                unsigned line,

                const char *section,

                unsigned section_line,

                const char *lvalue,

                int ltype,

                const char *rvalue,

                void *data,

                void *userdata) {

        _cleanup_free_ char *res = NULL;

        char **out = ASSERT_PTR(data);

        int r;

        assert(filename);

        assert(lvalue);

        assert(rvalue);

        /* XDG does not allow duplicate definitions. */

        if (*out) {

                log_syntax(unit, LOG_WARNING, filename, line, 0, "Key %s was defined multiple times, ignoring.", lvalue);

                return 0;

        }

        res = strdup(rvalue);

        if (!res)

                return log_oom();

        r = xdg_unescape_string(unit, filename, line, res);

        if (r < 0)

                return r;

        *out = TAKE_PTR(res);

        return 0;

}

static int strv_strndup_unescape_and_push(

                const char *unit,

                const char *filename,

                unsigned line,

                char ***sv,

                size_t *n,

                const char *start,

                const char *end) {

        if (end == start)

                return 0;

        _cleanup_free_ char *copy = NULL;

        int r;

        copy = strndup(start, end - start);

        if (!copy)

                return log_oom();

        r = xdg_unescape_string(unit, filename, line, copy);

        if (r < 0)

                return r;

        if (!GREEDY_REALLOC(*sv, *n + 2)) /* One extra for NULL */

                return log_oom();

        (*sv)[*n] = TAKE_PTR(copy);

        (*sv)[*n + 1] = NULL;

        (*n)++;

        return 0;

}

static int xdg_config_parse_strv(

                const char *unit,

                const char *filename,

                unsigned line,

                const char *section,

                unsigned section_line,

                const char *lvalue,

                int ltype,

                const char *rvalue,

                void *data,

                void *userdata) {

        char ***ret_sv = ASSERT_PTR(data);

        int r;

        assert(filename);

        assert(lvalue);

        assert(rvalue);

        /* XDG does not allow duplicate definitions. */

        if (*ret_sv) {

                log_syntax(unit, LOG_WARNING, filename, line, 0, "Key %s was already defined, ignoring.", lvalue);

                return 0;

        }

        size_t n = 0;

        _cleanup_strv_free_ char **sv = NULL;

        if (!GREEDY_REALLOC0(sv, 1))

                return log_oom();

        /* We cannot use strv_split because it does not handle escaping correctly. */

        const char *start = rvalue, *end;

        for (end = start; *end; end++) {

                if (*end == '\\') {

                        /* Move forward, and ensure it is a valid escape. */

                        end++;

                        if (!strchr("sntr\\;", *end)) {

                                log_syntax(unit, LOG_WARNING, filename, line, 0, "Undefined escape sequence \\%c.", *end);

                                return 0;

                        }

                        continue;

                }

                if (*end == ';') {

                        r = strv_strndup_unescape_and_push(unit, filename, line,

                                                           &sv, &n,

                                                           start, end);

                        if (r < 0)

                                return r;

                        start = end + 1;

                }

        }

        /* Handle the trailing entry after the last separator */

        r = strv_strndup_unescape_and_push(unit, filename, line,

                                           &sv, &n,

                                           start, end);

        if (r < 0)

                return r;

        *ret_sv = TAKE_PTR(sv);

        return 0;

}

static int xdg_config_item_table_lookup(

                const void *table,

                const char *section,

                const char *lvalue,

                ConfigParserCallback *ret_func,

                int *ret_ltype,

                void **ret_data,

                void *userdata) {

        assert(lvalue);

        /* Ignore any keys with [] as those are translations. */

        if (strchr(lvalue, '[')) {

                *ret_func = NULL;

                *ret_ltype = 0;

                *ret_data = NULL;

                return 1;

        }

        return config_item_table_lookup(table, section, lvalue, ret_func, ret_ltype, ret_data, userdata);

}

XdgAutostartService *xdg_autostart_service_parse_desktop(const char *path) {

        _cleanup_(xdg_autostart_service_freep) XdgAutostartService *service = NULL;

        int r;

        service = new0(XdgAutostartService, 1);

        if (!service)

                return NULL;

        service->path = strdup(path);

        if (!service->path)

                return NULL;

        const ConfigTableItem items[] = {

                { "Desktop Entry", "Name",                      xdg_config_parse_string, 0, &service->description             },

                { "Desktop Entry", "Exec",                      xdg_config_parse_string, 0, &service->exec_string             },

                { "Desktop Entry", "Path",                      xdg_config_parse_string, 0, &service->working_directory       },

                { "Desktop Entry", "TryExec",                   xdg_config_parse_string, 0, &service->try_exec                },

                { "Desktop Entry", "Type",                      xdg_config_parse_string, 0, &service->type                    },

                { "Desktop Entry", "OnlyShowIn",                xdg_config_parse_strv,   0, &service->only_show_in            },

                { "Desktop Entry", "NotShowIn",                 xdg_config_parse_strv,   0, &service->not_show_in             },

                { "Desktop Entry", "Hidden",                    xdg_config_parse_bool,   0, &service->hidden                  },

                { "Desktop Entry", "AutostartCondition",        xdg_config_parse_string, 0, &service->autostart_condition     },

                { "Desktop Entry", "X-KDE-autostart-condition", xdg_config_parse_string, 0, &service->kde_autostart_condition },

                { "Desktop Entry", "X-GNOME-Autostart-Phase",   xdg_config_parse_string, 0, &service->gnome_autostart_phase   },

                { "Desktop Entry", "X-systemd-skip",            xdg_config_parse_bool,   0, &service->systemd_skip            },

                /* Common entries that we do not use currently. */

                { "Desktop Entry", "Categories",                NULL, 0, NULL},

                { "Desktop Entry", "Comment",                   NULL, 0, NULL},

                { "Desktop Entry", "DBusActivatable",           NULL, 0, NULL},

                { "Desktop Entry", "Encoding",                  NULL, 0, NULL},

                { "Desktop Entry", "GenericName",               NULL, 0, NULL},

                { "Desktop Entry", "Icon",                      NULL, 0, NULL},

                { "Desktop Entry", "Keywords",                  NULL, 0, NULL},

                { "Desktop Entry", "MimeType",                  NULL, 0, NULL},

                { "Desktop Entry", "NoDisplay",                 NULL, 0, NULL},

                { "Desktop Entry", "StartupNotify",             NULL, 0, NULL},

                { "Desktop Entry", "StartupWMClass",            NULL, 0, NULL},

                { "Desktop Entry", "Terminal",                  NULL, 0, NULL},

                { "Desktop Entry", "URL",                       NULL, 0, NULL},

                { "Desktop Entry", "Version",                   NULL, 0, NULL},

                {}

        };

        r = config_parse(NULL, service->path, NULL,

                         "Desktop Entry\0",

                         xdg_config_item_table_lookup, items,

                         CONFIG_PARSE_RELAXED | CONFIG_PARSE_WARN,

                         service,

                         NULL);

        /* If parsing failed, only hide the file so it will still mask others. */

        if (r < 0) {

                log_warning_errno(r, "Failed to parse %s, ignoring it", service->path);

                service->hidden = true;

        }

        return TAKE_PTR(service);

}

int xdg_autostart_format_exec_start(

                const char *exec,

                char **ret_exec_start) {

        _cleanup_strv_free_ char **exec_split = NULL;

        char *res;

        size_t n, i;

        bool first_arg;

        int r;

        /*

         * Unfortunately, there is a mismatch between systemd's idea of $PATH and XDGs. I.e. we need to

         * ensure that we have an absolute path to support cases where $PATH has been modified from the

         * default set.

         *

         * Note that this is only needed for development environments though; so while it is important, this

         * should have no effect in production environments.

         *

         * To be compliant with the XDG specification, we also need to strip certain parameters and

         * such. Doing so properly makes parsing the command line unavoidable.

         *

         * NOTE: Technically, XDG only specifies " as quotes, while this also accepts '.

         */

        r = strv_split_full(&exec_split, exec, NULL, EXTRACT_UNQUOTE | EXTRACT_RELAX);

        if (r < 0)

                return r;

        if (strv_isempty(exec_split))

                return log_warning_errno(SYNTHETIC_ERRNO(EINVAL), "Exec line is empty");

        first_arg = true;

        for (i = n = 0; exec_split[i]; i++) {

                _cleanup_free_ char *c = NULL, *raw = NULL, *percent = NULL, *tilde_expanded = NULL;

                ssize_t l;

                l = cunescape(exec_split[i], 0, &c);

                if (l < 0)

                        return log_debug_errno(l, "Failed to unescape '%s': %m", exec_split[i]);

                if (first_arg) {

                        _cleanup_free_ char *executable = NULL;

                        /* This is the executable, find it in $PATH */

                        first_arg = false;

                        r = find_executable(c, &executable);

                        if (r < 0)

                                return log_info_errno(r, "Exec binary '%s' does not exist: %m", c);

                        free_and_replace(exec_split[n++], executable);

                        continue;

                }

                /*

                 * Remove any standardised XDG fields; we assume they never appear as part of another

                 * argument as that just does not make any sense as they can be empty (GLib will e.g. turn

                 * "%f" into an empty argument).  Other implementations may handle this differently.

                 */

                if (STR_IN_SET(c,

                               "%f", "%F",

                               "%u", "%U",

                               "%d", "%D",

                               "%n", "%N",

                               "%i",          /* Location of icon, could be implemented. */

                               "%c",          /* Translated application name, could be implemented. */

                               "%k",          /* Location of desktop file, could be implemented. */

                               "%v",

                               "%m"

                               ))

                        continue;

                /*

                 * %% -> % and then % -> %% means that we correctly quote any % and also quote any left over

                 * (and invalid) % specifier from the desktop file.

                 */

                raw = strreplace(c, "%%", "%");

                if (!raw)

                        return log_oom();

                percent = strreplace(raw, "%", "%%");

                if (!percent)

                        return log_oom();

                /*

                 * Expand ~ if it comes at the beginning of an argument to form a path.

                 *

                 * The specification does not mandate this, but we do it anyway for compatibility with

                 * older KDE code, which supported a more shell-like syntax for users making custom entries.

                 */

                if (percent[0] == '~' && (isempty(percent + 1) || path_is_absolute(percent + 1))) {

                        _cleanup_free_ char *home = NULL;

                        r = get_home_dir(&home);

                        if (r < 0)

                                return r;

                        tilde_expanded = path_join(home, &percent[1]);

                        if (!tilde_expanded)

                                return log_oom();

                        free_and_replace(exec_split[n++], tilde_expanded);

                } else

                        free_and_replace(exec_split[n++], percent);

        }

        for (; exec_split[n]; n++)

                exec_split[n] = mfree(exec_split[n]);

        res = quote_command_line(exec_split, SHELL_ESCAPE_EMPTY);

        if (!res)

                return log_oom();

        *ret_exec_start = res;

        return 0;

}

static int xdg_autostart_generate_desktop_condition(

                const XdgAutostartService *service,

                FILE *f,

                const char *test_binary,

                const char *condition) {

        int r;

        /* Generate an ExecCondition for GNOME autostart condition */

        if (!isempty(condition)) {

                _cleanup_free_ char *gnome_autostart_condition_path = NULL, *e_autostart_condition = NULL;

                r = find_executable(test_binary, &gnome_autostart_condition_path);

                if (r < 0) {

                        log_full_errno(r == -ENOENT ? LOG_DEBUG : LOG_WARNING, r,

                                       "%s: ExecCondition executable %s not found, unit will not be started automatically: %m",

                                       service->path, test_binary);

                        fprintf(f, "# ExecCondition using %s skipped due to missing binary.\n", test_binary);

                        return 0;

                }

                e_autostart_condition = cescape(condition);

                if (!e_autostart_condition)

                        return log_oom();

                log_debug("%s: ExecCondition converted to %s --condition \"%s\"%s",

                          service->path, gnome_autostart_condition_path, e_autostart_condition,

                          glyph(GLYPH_ELLIPSIS));

                fprintf(f,

                         "ExecCondition=%s --condition \"%s\"\n",

                         gnome_autostart_condition_path,

                         e_autostart_condition);

        }

        return 0;

}

int xdg_autostart_service_generate_unit(

                const XdgAutostartService *service,

                const char *dest) {

        _cleanup_free_ char *path_escaped = NULL, *exec_start = NULL;

        _cleanup_fclose_ FILE *f = NULL;

        _cleanup_strv_free_ char **only_show_in = NULL, **not_show_in = NULL;

        int r;

        assert(service);

        /* Nothing to do for hidden services. */

        if (service->hidden) {

                log_debug("%s: not generating unit, entry is hidden.", service->path);

                return 0;

        }

        if (service->systemd_skip) {

                log_debug("%s: not generating unit, marked as skipped by generator.", service->path);

                return 0;

        }

        /* Nothing to do if type is not Application. */

        if (!streq_ptr(service->type, "Application")) {

                log_debug("%s: not generating unit, Type=%s is not supported.", service->path, service->type);

                return 0;

        }

        if (!service->exec_string) {

                log_warning("%s: not generating unit, no Exec= line.", service->path);

                return 0;

        }

        if (service->only_show_in) {

                only_show_in = strv_copy(service->only_show_in);

                if (!only_show_in)

                        return log_oom();

        }

        if (service->not_show_in) {

                not_show_in = strv_copy(service->not_show_in);

                if (!not_show_in)

                        return log_oom();

        }

        /* The TryExec key cannot be checked properly from the systemd unit, it is trivial to check using

         * find_executable though. */

        if (service->try_exec) {

                r = find_executable(service->try_exec, NULL);

                if (r < 0) {

                        log_full_errno(r == -ENOENT ? LOG_DEBUG : LOG_WARNING, r,

                                       "%s: not generating unit, could not find TryExec= binary %s: %m",

                                       service->path, service->try_exec);

                        return 0;

                }

        }

        r = xdg_autostart_format_exec_start(service->exec_string, &exec_start);

        if (r < 0) {

                log_full_errno(r == -ENOENT ? LOG_INFO : LOG_WARNING, r,

                               r == -ENOENT ? "%s: not generating unit, executable specified in Exec= does not exist."

                                            : "%s: not generating unit, error parsing Exec= line: %m",

                               service->path);

                return 0;

        }

        if (service->gnome_autostart_phase) {

                /* There is no explicit value for the "Application" phase.

                 *

                 * On GNOME secondary startup mechanism handles desktop files with startup phases set.

                 * We want to mark these as "NotShowIn=GNOME"

                 *

                 * If that means no-one will load them, we can get skip it entirely.

                 */

                if (strv_contains(only_show_in, "GNOME")) {

                        strv_remove(only_show_in, "GNOME");

                        if (strv_isempty(only_show_in)) {

                                log_debug("%s: GNOME startup phases are handled separately. Skipping.",

                                          service->path);

                                return 0;

                        }

                }

                log_debug("%s: GNOME startup phases are handled separately, marking as NotShowIn=GNOME.",

                          service->path);

                if (strv_extend(&not_show_in, "GNOME") < 0)

                        return log_oom();

        }

        path_escaped = specifier_escape(service->path);

        if (!path_escaped)

                return log_oom();

        r = generator_open_unit_file(dest, /* source= */ NULL, service->name, &f);

        if (r < 0)

                return r;

        fprintf(f,

                "[Unit]\n"

                "Documentation=man:systemd-xdg-autostart-generator(8)\n"

                "SourcePath=%s\n"

                "PartOf=graphical-session.target\n\n",

                path_escaped);

        if (service->description) {

                _cleanup_free_ char *t = NULL;

                t = specifier_escape(service->description);

                if (!t)

                        return log_oom();

                fprintf(f, "Description=%s\n", t);

        }

        /* Only start after the session is ready. */

        fprintf(f,

                "After=graphical-session.target\n");

        fprintf(f,

                "\n[Service]\n"

                "Type=exec\n"

                "ExitType=cgroup\n"

                "ExecStart=:%s\n"

                "Restart=no\n"

                "TimeoutStopSec=5s\n"

                "Slice=app.slice\n",

                exec_start);

        if (service->working_directory) {

                _cleanup_free_ char *e_working_directory = NULL;

                e_working_directory = cescape(service->working_directory);

                if (!e_working_directory)

                        return log_oom();

                fprintf(f, "WorkingDirectory=-%s\n", e_working_directory);

        }

        /* Generate an ExecCondition to check $XDG_CURRENT_DESKTOP */

        if (!strv_isempty(only_show_in) || !strv_isempty(not_show_in)) {

                _cleanup_free_ char *only_show_in_string = NULL, *not_show_in_string = NULL, *e_only_show_in = NULL, *e_not_show_in = NULL;

                only_show_in_string = strv_join(only_show_in, ":");

                not_show_in_string = strv_join(not_show_in, ":");

                if (!only_show_in_string || !not_show_in_string)

                        return log_oom();

                e_only_show_in = cescape(only_show_in_string);

                e_not_show_in = cescape(not_show_in_string);

                if (!e_only_show_in || !e_not_show_in)

                        return log_oom();

                /* Just assume the values are reasonably sane */

                fprintf(f,

                        "ExecCondition=" LIBEXECDIR "/systemd-xdg-autostart-condition \"%s\" \"%s\"\n",

                        e_only_show_in,

                        e_not_show_in);

        }

        r = xdg_autostart_generate_desktop_condition(service, f,

                                                     "gnome-systemd-autostart-condition",

                                                     service->autostart_condition);

        if (r < 0)

                return r;

        r = xdg_autostart_generate_desktop_condition(service, f,

                                                     "kde-systemd-start-condition",

                                                     service->kde_autostart_condition);

        if (r < 0)

                return r;

        r = fflush_and_check(f);

        if (r < 0)

                return log_error_errno(r, "Failed to write unit %s: %m", service->name);

        log_debug("%s: symlinking %s in xdg-desktop-autostart.target/.wants%s",

                  service->path, service->name, glyph(GLYPH_ELLIPSIS));

        return generator_add_symlink(dest, "xdg-desktop-autostart.target", "wants", service->name);

}