swayfx/sway/main.c
Kenny Levinsen 67d3d952b6 Print deprecation notice when running SUID
SUID privilege drop is needed for the "builtin"-backend of libseat,
which copied our old "direct" backend behavior for the sake of
compatibility and ease of transition.

libseat now has a better alternative in the form of seatd-launch. It
uses the normal seatd daemon and libseat backend and takes care of SUID
for us.

Add a soft deprecation warning to highlight our future intent of
removing this code. The deprecation cycle is needed to avoid surprises
when sway no longer drops privileges.

(cherry picked from commit e1db1f8218998c428e8b087dda6660449ef2891a)
2022-01-16 19:26:57 +01:00

447 lines
11 KiB
C

#define _POSIX_C_SOURCE 200809L
#include <getopt.h>
#include <pango/pangocairo.h>
#include <signal.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/resource.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <sys/un.h>
#include <unistd.h>
#include <wlr/util/log.h>
#include <wlr/version.h>
#include "sway/commands.h"
#include "sway/config.h"
#include "sway/server.h"
#include "sway/swaynag.h"
#include "sway/desktop/transaction.h"
#include "sway/tree/root.h"
#include "sway/ipc-server.h"
#include "ipc-client.h"
#include "log.h"
#include "stringop.h"
#include "util.h"
static bool terminate_request = false;
static int exit_value = 0;
static struct rlimit original_nofile_rlimit = {0};
struct sway_server server = {0};
struct sway_debug debug = {0};
void sway_terminate(int exit_code) {
if (!server.wl_display) {
// Running as IPC client
exit(exit_code);
} else {
// Running as server
terminate_request = true;
exit_value = exit_code;
ipc_event_shutdown("exit");
wl_display_terminate(server.wl_display);
}
}
void sig_handler(int signal) {
sway_terminate(EXIT_SUCCESS);
}
void detect_proprietary(int allow_unsupported_gpu) {
FILE *f = fopen("/proc/modules", "r");
if (!f) {
return;
}
char *line = NULL;
size_t line_size = 0;
while (getline(&line, &line_size, f) != -1) {
if (strncmp(line, "nvidia ", 7) == 0) {
if (allow_unsupported_gpu) {
sway_log(SWAY_ERROR,
"!!! Proprietary Nvidia drivers are in use !!!");
} else {
sway_log(SWAY_ERROR,
"Proprietary Nvidia drivers are NOT supported. "
"Use Nouveau. To launch sway anyway, launch with "
"--unsupported-gpu and DO NOT report issues.");
exit(EXIT_FAILURE);
}
break;
}
if (strstr(line, "fglrx")) {
if (allow_unsupported_gpu) {
sway_log(SWAY_ERROR,
"!!! Proprietary AMD drivers are in use !!!");
} else {
sway_log(SWAY_ERROR, "Proprietary AMD drivers do NOT support "
"Wayland. Use radeon. To try anyway, launch sway with "
"--unsupported-gpu and DO NOT report issues.");
exit(EXIT_FAILURE);
}
break;
}
}
free(line);
fclose(f);
}
void run_as_ipc_client(char *command, char *socket_path) {
int socketfd = ipc_open_socket(socket_path);
uint32_t len = strlen(command);
char *resp = ipc_single_command(socketfd, IPC_COMMAND, command, &len);
printf("%s\n", resp);
free(resp);
close(socketfd);
}
static void log_env(void) {
const char *log_vars[] = {
"LD_LIBRARY_PATH",
"LD_PRELOAD",
"PATH",
"SWAYSOCK",
};
for (size_t i = 0; i < sizeof(log_vars) / sizeof(char *); ++i) {
char *value = getenv(log_vars[i]);
sway_log(SWAY_INFO, "%s=%s", log_vars[i], value != NULL ? value : "");
}
}
static void log_file(FILE *f) {
char *line = NULL;
size_t line_size = 0;
ssize_t nread;
while ((nread = getline(&line, &line_size, f)) != -1) {
if (line[nread - 1] == '\n') {
line[nread - 1] = '\0';
}
sway_log(SWAY_INFO, "%s", line);
}
free(line);
}
static void log_distro(void) {
const char *paths[] = {
"/etc/lsb-release",
"/etc/os-release",
"/etc/debian_version",
"/etc/redhat-release",
"/etc/gentoo-release",
};
for (size_t i = 0; i < sizeof(paths) / sizeof(char *); ++i) {
FILE *f = fopen(paths[i], "r");
if (f) {
sway_log(SWAY_INFO, "Contents of %s:", paths[i]);
log_file(f);
fclose(f);
}
}
}
static void log_kernel(void) {
FILE *f = popen("uname -a", "r");
if (!f) {
sway_log(SWAY_INFO, "Unable to determine kernel version");
return;
}
log_file(f);
pclose(f);
}
static bool drop_permissions(void) {
if (getuid() != geteuid() || getgid() != getegid()) {
sway_log(SWAY_ERROR, "!!! DEPRECATION WARNING: "
"SUID privilege drop will be removed in a future release, please migrate to seatd-launch");
// Set the gid and uid in the correct order.
if (setgid(getgid()) != 0) {
sway_log(SWAY_ERROR, "Unable to drop root group, refusing to start");
return false;
}
if (setuid(getuid()) != 0) {
sway_log(SWAY_ERROR, "Unable to drop root user, refusing to start");
return false;
}
}
if (setgid(0) != -1 || setuid(0) != -1) {
sway_log(SWAY_ERROR, "Unable to drop root (we shouldn't be able to "
"restore it after setuid), refusing to start");
return false;
}
return true;
}
static void increase_nofile_limit(void) {
if (getrlimit(RLIMIT_NOFILE, &original_nofile_rlimit) != 0) {
sway_log_errno(SWAY_ERROR, "Failed to bump max open files limit: "
"getrlimit(NOFILE) failed");
return;
}
struct rlimit new_rlimit = original_nofile_rlimit;
new_rlimit.rlim_cur = new_rlimit.rlim_max;
if (setrlimit(RLIMIT_NOFILE, &new_rlimit) != 0) {
sway_log_errno(SWAY_ERROR, "Failed to bump max open files limit: "
"setrlimit(NOFILE) failed");
sway_log(SWAY_INFO, "Running with %d max open files",
(int)original_nofile_rlimit.rlim_cur);
}
}
void restore_nofile_limit(void) {
if (original_nofile_rlimit.rlim_cur == 0) {
return;
}
if (setrlimit(RLIMIT_NOFILE, &original_nofile_rlimit) != 0) {
sway_log_errno(SWAY_ERROR, "Failed to restore max open files limit: "
"setrlimit(NOFILE) failed");
}
}
void enable_debug_flag(const char *flag) {
if (strcmp(flag, "damage=highlight") == 0) {
debug.damage = DAMAGE_HIGHLIGHT;
} else if (strcmp(flag, "damage=rerender") == 0) {
debug.damage = DAMAGE_RERENDER;
} else if (strcmp(flag, "noatomic") == 0) {
debug.noatomic = true;
} else if (strcmp(flag, "txn-wait") == 0) {
debug.txn_wait = true;
} else if (strcmp(flag, "txn-timings") == 0) {
debug.txn_timings = true;
} else if (strncmp(flag, "txn-timeout=", 12) == 0) {
server.txn_timeout_ms = atoi(&flag[12]);
} else if (strcmp(flag, "noscanout") == 0) {
debug.noscanout = true;
} else {
sway_log(SWAY_ERROR, "Unknown debug flag: %s", flag);
}
}
static sway_log_importance_t convert_wlr_log_importance(
enum wlr_log_importance importance) {
switch (importance) {
case WLR_ERROR:
return SWAY_ERROR;
case WLR_INFO:
return SWAY_INFO;
default:
return SWAY_DEBUG;
}
}
static void handle_wlr_log(enum wlr_log_importance importance,
const char *fmt, va_list args) {
static char sway_fmt[1024];
snprintf(sway_fmt, sizeof(sway_fmt), "[wlr] %s", fmt);
_sway_vlog(convert_wlr_log_importance(importance), sway_fmt, args);
}
int main(int argc, char **argv) {
static int verbose = 0, debug = 0, validate = 0, allow_unsupported_gpu = 0;
static const struct option long_options[] = {
{"help", no_argument, NULL, 'h'},
{"config", required_argument, NULL, 'c'},
{"validate", no_argument, NULL, 'C'},
{"debug", no_argument, NULL, 'd'},
{"version", no_argument, NULL, 'v'},
{"verbose", no_argument, NULL, 'V'},
{"get-socketpath", no_argument, NULL, 'p'},
{"unsupported-gpu", no_argument, NULL, 'u'},
{0, 0, 0, 0}
};
char *config_path = NULL;
const char* usage =
"Usage: sway [options] [command]\n"
"\n"
" -h, --help Show help message and quit.\n"
" -c, --config <config> Specify a config file.\n"
" -C, --validate Check the validity of the config file, then exit.\n"
" -d, --debug Enables full logging, including debug information.\n"
" -v, --version Show the version number and quit.\n"
" -V, --verbose Enables more verbose logging.\n"
" --get-socketpath Gets the IPC socket path and prints it, then exits.\n"
"\n";
int c;
while (1) {
int option_index = 0;
c = getopt_long(argc, argv, "hCdD:vVc:", long_options, &option_index);
if (c == -1) {
break;
}
switch (c) {
case 'h': // help
printf("%s", usage);
exit(EXIT_SUCCESS);
break;
case 'c': // config
free(config_path);
config_path = strdup(optarg);
break;
case 'C': // validate
validate = 1;
break;
case 'd': // debug
debug = 1;
break;
case 'D': // extended debug options
enable_debug_flag(optarg);
break;
case 'u':
allow_unsupported_gpu = 1;
break;
case 'v': // version
printf("sway version " SWAY_VERSION "\n");
exit(EXIT_SUCCESS);
break;
case 'V': // verbose
verbose = 1;
break;
case 'p': ; // --get-socketpath
if (getenv("SWAYSOCK")) {
printf("%s\n", getenv("SWAYSOCK"));
exit(EXIT_SUCCESS);
} else {
fprintf(stderr, "sway socket not detected.\n");
exit(EXIT_FAILURE);
}
break;
default:
fprintf(stderr, "%s", usage);
exit(EXIT_FAILURE);
}
}
// Since wayland requires XDG_RUNTIME_DIR to be set, abort with just the
// clear error message (when not running as an IPC client).
if (!getenv("XDG_RUNTIME_DIR") && optind == argc) {
fprintf(stderr,
"XDG_RUNTIME_DIR is not set in the environment. Aborting.\n");
exit(EXIT_FAILURE);
}
// As the 'callback' function for wlr_log is equivalent to that for
// sway, we do not need to override it.
if (debug) {
sway_log_init(SWAY_DEBUG, sway_terminate);
wlr_log_init(WLR_DEBUG, handle_wlr_log);
} else if (verbose) {
sway_log_init(SWAY_INFO, sway_terminate);
wlr_log_init(WLR_INFO, handle_wlr_log);
} else {
sway_log_init(SWAY_ERROR, sway_terminate);
wlr_log_init(WLR_ERROR, handle_wlr_log);
}
sway_log(SWAY_INFO, "Sway version " SWAY_VERSION);
sway_log(SWAY_INFO, "wlroots version " WLR_VERSION_STR);
log_kernel();
log_distro();
log_env();
if (optind < argc) { // Behave as IPC client
if (optind != 1) {
sway_log(SWAY_ERROR,
"Detected both options and positional arguments. If you "
"are trying to use the IPC client, options are not "
"supported. Otherwise, check the provided arguments for "
"issues. See `man 1 sway` or `sway -h` for usage. If you "
"are trying to generate a debug log, use "
"`sway -d 2>sway.log`.");
exit(EXIT_FAILURE);
}
if (!drop_permissions()) {
exit(EXIT_FAILURE);
}
char *socket_path = getenv("SWAYSOCK");
if (!socket_path) {
sway_log(SWAY_ERROR, "Unable to retrieve socket path");
exit(EXIT_FAILURE);
}
char *command = join_args(argv + optind, argc - optind);
run_as_ipc_client(command, socket_path);
free(command);
return 0;
}
detect_proprietary(allow_unsupported_gpu);
if (!server_privileged_prepare(&server)) {
return 1;
}
if (!drop_permissions()) {
server_fini(&server);
exit(EXIT_FAILURE);
}
increase_nofile_limit();
// handle SIGTERM signals
signal(SIGTERM, sig_handler);
signal(SIGINT, sig_handler);
// prevent ipc from crashing sway
signal(SIGPIPE, SIG_IGN);
sway_log(SWAY_INFO, "Starting sway version " SWAY_VERSION);
root = root_create();
if (!server_init(&server)) {
return 1;
}
if (validate) {
bool valid = load_main_config(config_path, false, true);
free(config_path);
return valid ? 0 : 1;
}
ipc_init(&server);
setenv("WAYLAND_DISPLAY", server.socket, true);
if (!load_main_config(config_path, false, false)) {
sway_terminate(EXIT_FAILURE);
goto shutdown;
}
if (!server_start(&server)) {
sway_terminate(EXIT_FAILURE);
goto shutdown;
}
config->active = true;
load_swaybars();
run_deferred_commands();
run_deferred_bindings();
transaction_commit_dirty();
if (config->swaynag_config_errors.client != NULL) {
swaynag_show(&config->swaynag_config_errors);
}
server_run(&server);
shutdown:
sway_log(SWAY_INFO, "Shutting down sway");
server_fini(&server);
root_destroy(root);
root = NULL;
free(config_path);
free_config(config);
pango_cairo_font_map_set_default(NULL);
return exit_value;
}