sway/sway/main.c
Dan Robertson 88d042ec49
nvidia: Validate the nvidia_drm module options
When the proprietary nvidia driver is used, ensure the modeset option is
set instead of checking /proc/cmdline for nvidia-drm.modeset=1.
2017-10-24 22:35:31 +00:00

501 lines
12 KiB
C

#define _XOPEN_SOURCE 700
#define _POSIX_C_SOURCE 200112L
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <wlc/wlc.h>
#include <sys/wait.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/un.h>
#include <signal.h>
#include <unistd.h>
#include <getopt.h>
#ifdef __linux__
#include <sys/capability.h>
#include <sys/prctl.h>
#endif
#include "sway/extensions.h"
#include "sway/layout.h"
#include "sway/config.h"
#include "sway/security.h"
#include "sway/handlers.h"
#include "sway/input.h"
#include "sway/ipc-server.h"
#include "ipc-client.h"
#include "readline.h"
#include "stringop.h"
#include "sway.h"
#include "log.h"
#include "util.h"
static bool terminate_request = false;
static int exit_value = 0;
void sway_terminate(int exit_code) {
terminate_request = true;
exit_value = exit_code;
wlc_terminate();
}
void sig_handler(int signal) {
close_views(&root_container);
sway_terminate(EXIT_SUCCESS);
}
static void wlc_log_handler(enum wlc_log_type type, const char *str) {
if (type == WLC_LOG_ERROR) {
sway_log(L_ERROR, "[wlc] %s", str);
} else if (type == WLC_LOG_WARN) {
sway_log(L_INFO, "[wlc] %s", str);
} else {
sway_log(L_DEBUG, "[wlc] %s", str);
}
}
void detect_raspi() {
bool raspi = false;
FILE *f = fopen("/sys/firmware/devicetree/base/model", "r");
if (!f) {
return;
}
char *line;
while(!feof(f)) {
if (!(line = read_line(f))) {
break;
}
if (strstr(line, "Raspberry Pi")) {
raspi = true;
}
free(line);
}
fclose(f);
FILE *g = fopen("/proc/modules", "r");
if (!g) {
return;
}
bool vc4 = false;
while (!feof(g)) {
if (!(line = read_line(g))) {
break;
}
if (strstr(line, "vc4")) {
vc4 = true;
}
free(line);
}
fclose(g);
if (!vc4 && raspi) {
fprintf(stderr, "\x1B[1;31mWarning: You have a "
"Raspberry Pi, but the vc4 Module is "
"not loaded! Set 'dtoverlay=vc4-kms-v3d'"
"in /boot/config.txt and reboot.\x1B[0m\n");
}
}
void detect_proprietary() {
FILE *f = fopen("/proc/modules", "r");
if (!f) {
return;
}
bool nvidia = false, nvidia_modeset = false, nvidia_uvm = false, nvidia_drm = false;
while (!feof(f)) {
char *line;
if (!(line = read_line(f))) {
break;
}
if (strstr(line, "nvidia")) {
nvidia = true;
}
if (strstr(line, "nvidia_modeset")) {
nvidia_modeset = true;
}
if (strstr(line, "nvidia_uvm")) {
nvidia_uvm = true;
}
if (strstr(line, "nvidia_drm")) {
nvidia_drm = true;
}
if (strstr(line, "fglrx")) {
fprintf(stderr, "\x1B[1;31mWarning: Proprietary AMD drivers do "
"NOT support Wayland. Use radeon.\x1B[0m\n");
free(line);
break;
}
free(line);
}
fclose(f);
if (nvidia) {
fprintf(stderr, "\x1B[1;31mWarning: Proprietary nvidia driver support "
"is considered experimental. Nouveau is strongly recommended."
"\x1B[0m\n");
if (!nvidia_modeset || !nvidia_uvm || !nvidia_drm) {
fprintf(stderr, "\x1B[1;31mWarning: You do not have all of the "
"necessary kernel modules loaded for nvidia support. "
"You need nvidia, nvidia_modeset, nvidia_uvm, and nvidia_drm."
"\x1B[0m\n");
}
#ifdef __linux__
f = fopen("/sys/module/nvidia_drm/parameters/modeset", "r");
if (f) {
char *line = read_line(f);
if (line && strstr(line, "Y")) {
// nvidia-drm.modeset is set to 0
fprintf(stderr, "\x1B[1;31mWarning: You must load "
"nvidia-drm with the modeset option on to use "
"the proprietary driver. Consider adding "
"nvidia-drm.modeset=1 to your kernel command line "
"parameters.\x1B[0m\n");
}
fclose(f);
free(line);
} else {
// nvidia-drm.modeset is not set
fprintf(stderr, "\x1B[1;31mWarning: You must load "
"nvidia-drm with the modeset option on to use "
"the proprietary driver. Consider adding "
"nvidia-drm.modeset=1 to your kernel command line "
"parameters.\x1B[0m\n");
}
#else
f = fopen("/proc/cmdline", "r");
if (f) {
char *line = read_line(f);
if (line && !strstr(line, "nvidia-drm.modeset=1")) {
fprintf(stderr, "\x1B[1;31mWarning: You must add "
"nvidia-drm.modeset=1 to your kernel command line to use "
"the proprietary driver.\x1B[0m\n");
}
fclose(f);
free(line);
}
#endif
}
}
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);
close(socketfd);
}
static void log_env() {
const char *log_vars[] = {
"PATH",
"LD_LOAD_PATH",
"LD_PRELOAD_PATH",
"LD_LIBRARY_PATH",
"SWAY_CURSOR_THEME",
"SWAY_CURSOR_SIZE",
"SWAYSOCK",
"WLC_DRM_DEVICE",
"WLC_SHM",
"WLC_OUTPUTS",
"WLC_XWAYLAND",
"WLC_LIBINPUT",
"WLC_REPEAT_DELAY",
"WLC_REPEAT_RATE",
"XKB_DEFAULT_RULES",
"XKB_DEFAULT_MODEL",
"XKB_DEFAULT_LAYOUT",
"XKB_DEFAULT_VARIANT",
"XKB_DEFAULT_OPTIONS",
};
for (size_t i = 0; i < sizeof(log_vars) / sizeof(char *); ++i) {
sway_log(L_INFO, "%s=%s", log_vars[i], getenv(log_vars[i]));
}
}
static void log_distro() {
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(L_INFO, "Contents of %s:", paths[i]);
while (!feof(f)) {
char *line;
if (!(line = read_line(f))) {
break;
}
if (*line) {
sway_log(L_INFO, "%s", line);
}
free(line);
}
fclose(f);
}
}
}
static void log_kernel() {
FILE *f = popen("uname -a", "r");
if (!f) {
sway_log(L_INFO, "Unable to determine kernel version");
return;
}
while (!feof(f)) {
char *line;
if (!(line = read_line(f))) {
break;
}
if (*line) {
sway_log(L_INFO, "%s", line);
}
free(line);
}
fclose(f);
}
static void security_sanity_check() {
// TODO: Notify users visually if this has issues
struct stat s;
if (stat("/proc", &s)) {
sway_log(L_ERROR,
"!! DANGER !! /proc is not available - sway CANNOT enforce security rules!");
}
#ifdef __linux__
cap_flag_value_t v;
cap_t cap = cap_get_proc();
if (!cap || cap_get_flag(cap, CAP_SYS_PTRACE, CAP_PERMITTED, &v) != 0 || v != CAP_SET) {
sway_log(L_ERROR,
"!! DANGER !! Sway does not have CAP_SYS_PTRACE and cannot enforce security rules for processes running as other users.");
}
if (cap) {
cap_free(cap);
}
#endif
}
static void executable_sanity_check() {
#ifdef __linux__
struct stat sb;
char *exe = realpath("/proc/self/exe", NULL);
stat(exe, &sb);
// We assume that cap_get_file returning NULL implies ENODATA
if (sb.st_mode & (S_ISUID|S_ISGID) && cap_get_file(exe)) {
sway_log(L_ERROR,
"sway executable has both the s(g)uid bit AND file caps set.");
sway_log(L_ERROR,
"This is strongly discouraged (and completely broken).");
sway_log(L_ERROR,
"Please clear one of them (either the suid bit, or the file caps).");
sway_log(L_ERROR,
"If unsure, strip the file caps.");
exit(EXIT_FAILURE);
}
free(exe);
#endif
}
int main(int argc, char **argv) {
static int verbose = 0, debug = 0, validate = 0;
static 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'},
{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";
// Security:
unsetenv("LD_PRELOAD");
#ifdef _LD_LIBRARY_PATH
setenv("LD_LIBRARY_PATH", _LD_LIBRARY_PATH, 1);
#else
unsetenv("LD_LIBRARY_PATH");
#endif
int c;
while (1) {
int option_index = 0;
c = getopt_long(argc, argv, "hCdvVc:", long_options, &option_index);
if (c == -1) {
break;
}
switch (c) {
case 'h': // help
fprintf(stdout, "%s", usage);
exit(EXIT_SUCCESS);
break;
case 'c': // config
config_path = strdup(optarg);
break;
case 'C': // validate
validate = 1;
break;
case 'd': // debug
debug = 1;
break;
case 'v': // version
fprintf(stdout, "sway version " SWAY_VERSION "\n");
exit(EXIT_SUCCESS);
break;
case 'V': // verbose
verbose = 1;
break;
case 'p': ; // --get-socketpath
if (getenv("SWAYSOCK")) {
fprintf(stdout, "%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);
}
}
// we need to setup logging before wlc_init in case it fails.
if (debug) {
init_log(L_DEBUG);
} else if (verbose || validate) {
init_log(L_INFO);
} else {
init_log(L_ERROR);
}
if (optind < argc) { // Behave as IPC client
if(optind != 1) {
sway_log(L_ERROR, "Don't use options with the IPC client");
exit(EXIT_FAILURE);
}
if (getuid() != geteuid() || getgid() != getegid()) {
if (setgid(getgid()) != 0) {
sway_log(L_ERROR, "Unable to drop root");
exit(EXIT_FAILURE);
}
if (setuid(getuid()) != 0) {
sway_log(L_ERROR, "Unable to drop root");
exit(EXIT_FAILURE);
}
}
if (setuid(0) != -1) {
sway_log(L_ERROR, "Root privileges can be restored.");
exit(EXIT_FAILURE);
}
char *socket_path = getenv("SWAYSOCK");
if (!socket_path) {
sway_log(L_ERROR, "Unable to retrieve socket path");
exit(EXIT_FAILURE);
}
char *command = join_args(argv + optind, argc - optind);
run_as_ipc_client(command, socket_path);
return 0;
}
executable_sanity_check();
#ifdef __linux__
bool suid = false;
if (getuid() != geteuid() || getgid() != getegid()) {
// Retain capabilities after setuid()
if (prctl(PR_SET_KEEPCAPS, 1, 0, 0, 0)) {
sway_log(L_ERROR, "Cannot keep caps after setuid()");
exit(EXIT_FAILURE);
}
suid = true;
}
#endif
wlc_log_set_handler(wlc_log_handler);
log_kernel();
log_distro();
log_env();
detect_proprietary();
detect_raspi();
input_devices = create_list();
/* Changing code earlier than this point requires detailed review */
/* (That code runs as root on systems without logind, and wlc_init drops to
* another user.) */
register_wlc_handlers();
if (!wlc_init()) {
return 1;
}
register_extensions();
#ifdef __linux__
if (suid) {
// Drop every cap except CAP_SYS_PTRACE
cap_t caps = cap_init();
cap_value_t keep = CAP_SYS_PTRACE;
sway_log(L_INFO, "Dropping extra capabilities");
if (cap_set_flag(caps, CAP_PERMITTED, 1, &keep, CAP_SET) ||
cap_set_flag(caps, CAP_EFFECTIVE, 1, &keep, CAP_SET) ||
cap_set_proc(caps)) {
sway_log(L_ERROR, "Failed to drop extra capabilities");
exit(EXIT_FAILURE);
}
}
#endif
// handle SIGTERM signals
signal(SIGTERM, sig_handler);
// prevent ipc from crashing sway
signal(SIGPIPE, SIG_IGN);
sway_log(L_INFO, "Starting sway version " SWAY_VERSION "\n");
init_layout();
ipc_init();
if (validate) {
bool valid = load_main_config(config_path, false);
return valid ? 0 : 1;
}
if (!load_main_config(config_path, false)) {
sway_terminate(EXIT_FAILURE);
}
if (config_path) {
free(config_path);
}
security_sanity_check();
if (!terminate_request) {
wlc_run();
}
list_free(input_devices);
ipc_terminate();
if (config) {
free_config(config);
}
return exit_value;
}