Files
ttyd/src/server.c

614 lines
21 KiB
C

#include "server.h"
#include <errno.h>
#include <getopt.h>
#include <json.h>
#include <libwebsockets.h>
#include <signal.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include "utils.h"
#ifndef TTYD_VERSION
#define TTYD_VERSION "unknown"
#endif
volatile bool force_exit = false;
struct lws_context *context;
struct server *server;
struct endpoints endpoints = {"/ws", "/", "/token", ""};
extern int callback_http(struct lws *wsi, enum lws_callback_reasons reason, void *user, void *in, size_t len);
extern int callback_tty(struct lws *wsi, enum lws_callback_reasons reason, void *user, void *in, size_t len);
// websocket protocols
static const struct lws_protocols protocols[] = {{"http-only", callback_http, sizeof(struct pss_http), 0},
{"tty", callback_tty, sizeof(struct pss_tty), 0},
{NULL, NULL, 0, 0}};
#ifndef LWS_WITHOUT_EXTENSIONS
// websocket extensions
static const struct lws_extension extensions[] = {
{"permessage-deflate", lws_extension_callback_pm_deflate, "permessage-deflate"},
{"deflate-frame", lws_extension_callback_pm_deflate, "deflate_frame"},
{NULL, NULL, NULL}};
#endif
#if LWS_LIBRARY_VERSION_NUMBER >= 4000000
static const uint32_t backoff_ms[] = {1000, 2000, 3000, 4000, 5000};
static lws_retry_bo_t retry = {
.retry_ms_table = backoff_ms,
.retry_ms_table_count = LWS_ARRAY_SIZE(backoff_ms),
.conceal_count = LWS_ARRAY_SIZE(backoff_ms),
.secs_since_valid_ping = 5,
.secs_since_valid_hangup = 10,
.jitter_percent = 0,
};
#endif
// command line options
static const struct option options[] = {{"port", required_argument, NULL, 'p'},
{"interface", required_argument, NULL, 'i'},
{"socket-owner", required_argument, NULL, 'U'},
{"credential", required_argument, NULL, 'c'},
{"auth-header", required_argument, NULL, 'H'},
{"uid", required_argument, NULL, 'u'},
{"gid", required_argument, NULL, 'g'},
{"signal", required_argument, NULL, 's'},
{"cwd", required_argument, NULL, 'w'},
{"index", required_argument, NULL, 'I'},
{"base-path", required_argument, NULL, 'b'},
#if LWS_LIBRARY_VERSION_NUMBER >= 4000000
{"ping-interval", required_argument, NULL, 'P'},
#endif
{"ipv6", no_argument, NULL, '6'},
{"ssl", no_argument, NULL, 'S'},
{"ssl-cert", required_argument, NULL, 'C'},
{"ssl-key", required_argument, NULL, 'K'},
{"ssl-ca", required_argument, NULL, 'A'},
{"url-arg", no_argument, NULL, 'a'},
{"readonly", no_argument, NULL, 'R'},
{"terminal-type", required_argument, NULL, 'T'},
{"client-option", required_argument, NULL, 't'},
{"check-origin", no_argument, NULL, 'O'},
{"max-clients", required_argument, NULL, 'm'},
{"once", no_argument, NULL, 'o'},
{"browser", no_argument, NULL, 'B'},
{"debug", required_argument, NULL, 'd'},
{"version", no_argument, NULL, 'v'},
{"help", no_argument, NULL, 'h'},
{NULL, 0, 0, 0}};
static const char *opt_string = "p:i:c:H:u:g:s:w:I:b:P:6aSC:K:A:Rt:T:Om:oBd:vh";
static void print_help() {
// clang-format off
fprintf(stderr, "ttyd is a tool for sharing terminal over the web\n\n"
"USAGE:\n"
" ttyd [options] <command> [<arguments...>]\n\n"
"VERSION:\n"
" %s\n\n"
"OPTIONS:\n"
" -p, --port Port to listen (default: 7681, use `0` for random port)\n"
" -i, --interface Network interface to bind (eg: eth0), or UNIX domain socket path (eg: /var/run/ttyd.sock)\n"
" -U, --socket-owner User owner of the UNIX domain socket file, when enabled (eg: user:group)\n"
" -c, --credential Credential for basic authentication (format: username:password)\n"
" -H, --auth-header HTTP Header name for auth proxy, this will configure ttyd to let a HTTP reverse proxy handle authentication\n"
" -u, --uid User id to run with\n"
" -g, --gid Group id to run with\n"
" -s, --signal Signal to send to the command when exit it (default: 1, SIGHUP)\n"
" -w, --cwd Working directory to be set for the child program\n"
" -a, --url-arg Allow client to send command line arguments in URL (eg: http://localhost:7681?arg=foo&arg=bar)\n"
" -R, --readonly Do not allow clients to write to the TTY\n"
" -t, --client-option Send option to client (format: key=value), repeat to add more options\n"
" -T, --terminal-type Terminal type to report, default: xterm-256color\n"
" -O, --check-origin Do not allow websocket connection from different origin\n"
" -m, --max-clients Maximum clients to support (default: 0, no limit)\n"
" -o, --once Accept only one client and exit on disconnection\n"
" -B, --browser Open terminal with the default system browser\n"
" -I, --index Custom index.html path\n"
" -b, --base-path Expected base path for requests coming from a reverse proxy (eg: /mounted/here, max length: 128)\n"
#if LWS_LIBRARY_VERSION_NUMBER >= 4000000
" -P, --ping-interval Websocket ping interval(sec) (default: 5)\n"
#endif
#ifdef LWS_WITH_IPV6
" -6, --ipv6 Enable IPv6 support\n"
#endif
#if defined(LWS_OPENSSL_SUPPORT) || defined(LWS_WITH_TLS)
" -S, --ssl Enable SSL\n"
" -C, --ssl-cert SSL certificate file path\n"
" -K, --ssl-key SSL key file path\n"
" -A, --ssl-ca SSL CA file path for client certificate verification\n"
#endif
" -d, --debug Set log level (default: 7)\n"
" -v, --version Print the version and exit\n"
" -h, --help Print this text and exit\n\n"
"Visit https://github.com/tsl0922/ttyd to get more information and report bugs.\n",
TTYD_VERSION
);
// clang-format on
}
static void print_config() {
lwsl_notice("tty configuration:\n");
if (server->credential != NULL) lwsl_notice(" credential: %s\n", server->credential);
lwsl_notice(" start command: %s\n", server->command);
lwsl_notice(" close signal: %s (%d)\n", server->sig_name, server->sig_code);
lwsl_notice(" terminal type: %s\n", server->terminal_type);
if (endpoints.parent[0]) {
lwsl_notice("endpoints:\n");
lwsl_notice(" base-path: %s\n", endpoints.parent);
lwsl_notice(" index : %s\n", endpoints.index);
lwsl_notice(" token : %s\n", endpoints.token);
lwsl_notice(" websocket: %s\n", endpoints.ws);
}
if (server->auth_header != NULL) lwsl_notice(" auth header: %s\n", server->auth_header);
if (server->check_origin) lwsl_notice(" check origin: true\n");
if (server->url_arg) lwsl_notice(" allow url arg: true\n");
if (server->readonly) lwsl_notice(" readonly: true\n");
if (server->max_clients > 0) lwsl_notice(" max clients: %d\n", server->max_clients);
if (server->once) lwsl_notice(" once: true\n");
if (server->index != NULL) lwsl_notice(" custom index.html: %s\n", server->index);
}
static struct server *server_new(int argc, char **argv, int start) {
struct server *ts;
size_t cmd_len = 0;
ts = xmalloc(sizeof(struct server));
memset(ts, 0, sizeof(struct server));
ts->client_count = 0;
ts->sig_code = SIGHUP;
sprintf(ts->terminal_type, "%s", "xterm-256color");
get_sig_name(ts->sig_code, ts->sig_name, sizeof(ts->sig_name));
if (start == argc) return ts;
int cmd_argc = argc - start;
char **cmd_argv = &argv[start];
ts->argv = xmalloc(sizeof(char *) * (cmd_argc + 1));
for (int i = 0; i < cmd_argc; i++) {
ts->argv[i] = strdup(cmd_argv[i]);
cmd_len += strlen(ts->argv[i]);
if (i != cmd_argc - 1) {
cmd_len++; // for space
}
}
ts->argv[cmd_argc] = NULL;
ts->argc = cmd_argc;
ts->command = xmalloc(cmd_len + 1);
char *ptr = ts->command;
for (int i = 0; i < cmd_argc; i++) {
size_t len = strlen(ts->argv[i]);
ptr = memcpy(ptr, ts->argv[i], len + 1) + len;
if (i != cmd_argc - 1) {
*ptr++ = ' ';
}
}
*ptr = '\0'; // null terminator
ts->loop = xmalloc(sizeof *ts->loop);
uv_loop_init(ts->loop);
return ts;
}
static void server_free(struct server *ts) {
if (ts == NULL) return;
if (ts->credential != NULL) free(ts->credential);
if (ts->auth_header != NULL) free(ts->auth_header);
if (ts->index != NULL) free(ts->index);
if (ts->cwd != NULL) free(ts->cwd);
free(ts->command);
free(ts->prefs_json);
char **p = ts->argv;
for (; *p; p++) free(*p);
free(ts->argv);
if (strlen(ts->socket_path) > 0) {
struct stat st;
if (!stat(ts->socket_path, &st)) {
unlink(ts->socket_path);
}
}
uv_loop_close(ts->loop);
free(ts->loop);
free(ts);
}
static void signal_cb(uv_signal_t *watcher, int signum) {
char sig_name[20];
switch (watcher->signum) {
case SIGINT:
case SIGTERM:
get_sig_name(watcher->signum, sig_name, sizeof(sig_name));
lwsl_notice("received signal: %s (%d), exiting...\n", sig_name, watcher->signum);
break;
default:
signal(SIGABRT, SIG_DFL);
abort();
}
if (force_exit) exit(EXIT_FAILURE);
force_exit = true;
lws_cancel_service(context);
uv_stop(server->loop);
lwsl_notice("send ^C to force exit.\n");
}
static int parse_int(char *name, char *str) {
char *endptr;
errno = 0;
long val = strtol(str, &endptr, 0);
if (errno != 0 || endptr == str) {
fprintf(stderr, "ttyd: invalid value for %s: %s\n", name, str);
exit(EXIT_FAILURE);
}
return (int)val;
}
static int calc_command_start(int argc, char **argv) {
// make a copy of argc and argv
int argc_copy = argc;
char **argv_copy = xmalloc(sizeof(char *) * argc);
for (int i = 0; i < argc; i++) {
argv_copy[i] = strdup(argv[i]);
}
// do not print error message for invalid option
opterr = 0;
while (getopt_long(argc_copy, argv_copy, opt_string, options, NULL) != -1)
;
int start = argc;
if (optind < argc) {
char *command = argv_copy[optind];
for (int i = 0; i < argc; i++) {
if (strcmp(argv[i], command) == 0) {
start = i;
break;
}
}
}
// free argv copy
for (int i = 0; i < argc; i++) {
free(argv_copy[i]);
}
free(argv_copy);
// reset for next use
opterr = 1;
optind = 0;
return start;
}
int main(int argc, char **argv) {
if (argc == 1) {
print_help();
return 0;
}
#ifdef _WIN32
if (!conpty_init()) {
fprintf(stderr, "ERROR: ConPTY init failed! Make sure you are on Windows 10 1809 or later.");
return 1;
}
#endif
int start = calc_command_start(argc, argv);
server = server_new(argc, argv, start);
struct lws_context_creation_info info;
memset(&info, 0, sizeof(info));
info.port = 7681;
info.iface = NULL;
info.protocols = protocols;
info.gid = -1;
info.uid = -1;
info.max_http_header_pool = 16;
info.options = LWS_SERVER_OPTION_LIBUV | LWS_SERVER_OPTION_VALIDATE_UTF8 | LWS_SERVER_OPTION_DISABLE_IPV6;
#ifndef LWS_WITHOUT_EXTENSIONS
info.extensions = extensions;
#endif
info.max_http_header_data = 20480;
int debug_level = LLL_ERR | LLL_WARN | LLL_NOTICE;
char iface[128] = "";
char socket_owner[128] = "";
bool browser = false;
bool ssl = false;
char cert_path[1024] = "";
char key_path[1024] = "";
char ca_path[1024] = "";
struct json_object *client_prefs = json_object_new_object();
// parse command line options
int c;
while ((c = getopt_long(start, argv, opt_string, options, NULL)) != -1) {
switch (c) {
case 'h':
print_help();
return 0;
case 'v':
printf("ttyd version %s\n", TTYD_VERSION);
return 0;
case 'd':
debug_level = parse_int("debug", optarg);
break;
case 'a':
server->url_arg = true;
break;
case 'R':
server->readonly = true;
break;
case 'O':
server->check_origin = true;
break;
case 'm':
server->max_clients = parse_int("max-clients", optarg);
break;
case 'o':
server->once = true;
break;
case 'B':
browser = true;
break;
case 'p':
info.port = parse_int("port", optarg);
if (info.port < 0) {
fprintf(stderr, "ttyd: invalid port: %s\n", optarg);
return -1;
}
break;
case 'i':
strncpy(iface, optarg, sizeof(iface) - 1);
iface[sizeof(iface) - 1] = '\0';
break;
case 'U':
strncpy(socket_owner, optarg, sizeof(socket_owner) - 1);
socket_owner[sizeof(socket_owner) - 1] = '\0';
break;
case 'c':
if (strchr(optarg, ':') == NULL) {
fprintf(stderr, "ttyd: invalid credential, format: username:password\n");
return -1;
}
char b64_text[256];
lws_b64_encode_string(optarg, strlen(optarg), b64_text, sizeof(b64_text));
server->credential = strdup(b64_text);
break;
case 'H':
server->auth_header = strdup(optarg);
break;
case 'u':
info.uid = parse_int("uid", optarg);
break;
case 'g':
info.gid = parse_int("gid", optarg);
break;
case 's': {
int sig = get_sig(optarg);
if (sig > 0) {
server->sig_code = sig;
get_sig_name(sig, server->sig_name, sizeof(server->sig_name));
} else {
fprintf(stderr, "ttyd: invalid signal: %s\n", optarg);
return -1;
}
} break;
case 'w':
server->cwd = strdup(optarg);
break;
case 'I':
if (!strncmp(optarg, "~/", 2)) {
const char *home = getenv("HOME");
server->index = malloc(strlen(home) + strlen(optarg) - 1);
sprintf(server->index, "%s%s", home, optarg + 1);
} else {
server->index = strdup(optarg);
}
struct stat st;
if (stat(server->index, &st) == -1) {
fprintf(stderr, "Can not stat index.html: %s, error: %s\n", server->index, strerror(errno));
return -1;
}
if (S_ISDIR(st.st_mode)) {
fprintf(stderr, "Invalid index.html path: %s, is it a dir?\n", server->index);
return -1;
}
break;
case 'b': {
char path[128];
strncpy(path, optarg, 128);
size_t len = strlen(path);
while (len && path[len - 1] == '/') path[--len] = 0; // trim trailing /
if (!len) break;
#define sc(f) \
strncpy(path + len, endpoints.f, 128 - len); \
endpoints.f = strdup(path);
sc(ws) sc(index) sc(token) sc(parent)
#undef sc
} break;
#if LWS_LIBRARY_VERSION_NUMBER >= 4000000
case 'P': {
int interval = parse_int("ping-interval", optarg);
if (interval < 0) {
fprintf(stderr, "ttyd: invalid ping interval: %s\n", optarg);
return -1;
}
retry.secs_since_valid_ping = interval;
retry.secs_since_valid_hangup = interval + 7;
} break;
#endif
case '6':
info.options &= ~(LWS_SERVER_OPTION_DISABLE_IPV6);
break;
#if defined(LWS_OPENSSL_SUPPORT) || defined(LWS_WITH_TLS)
case 'S':
ssl = true;
break;
case 'C':
strncpy(cert_path, optarg, sizeof(cert_path) - 1);
cert_path[sizeof(cert_path) - 1] = '\0';
break;
case 'K':
strncpy(key_path, optarg, sizeof(key_path) - 1);
key_path[sizeof(key_path) - 1] = '\0';
break;
case 'A':
strncpy(ca_path, optarg, sizeof(ca_path) - 1);
ca_path[sizeof(ca_path) - 1] = '\0';
break;
#endif
case 'T':
strncpy(server->terminal_type, optarg, sizeof(server->terminal_type) - 1);
server->terminal_type[sizeof(server->terminal_type) - 1] = '\0';
break;
case '?':
break;
case 't':
optind--;
for (; optind < start && *argv[optind] != '-'; optind++) {
char *option = optarg;
char *key = strsep(&option, "=");
if (key == NULL) {
fprintf(stderr, "ttyd: invalid client option: %s, format: key=value\n", optarg);
return -1;
}
char *value = strsep(&option, "=");
if (value == NULL) {
fprintf(stderr, "ttyd: invalid client option: %s, format: key=value\n", optarg);
return -1;
}
struct json_object *obj = json_tokener_parse(value);
json_object_object_add(client_prefs, key, obj != NULL ? obj : json_object_new_string(value));
}
break;
default:
print_help();
return -1;
}
}
server->prefs_json = strdup(json_object_to_json_string(client_prefs));
json_object_put(client_prefs);
if (server->command == NULL || strlen(server->command) == 0) {
fprintf(stderr, "ttyd: missing start command\n");
return -1;
}
lws_set_log_level(debug_level, NULL);
char server_hdr[128] = "";
sprintf(server_hdr, "ttyd/%s (libwebsockets/%s)", TTYD_VERSION, LWS_LIBRARY_VERSION);
info.server_string = server_hdr;
#if LWS_LIBRARY_VERSION_NUMBER < 4000000
info.ws_ping_pong_interval = 5;
#else
info.retry_and_idle_policy = &retry;
#endif
if (strlen(iface) > 0) {
info.iface = iface;
if (endswith(info.iface, ".sock") || endswith(info.iface, ".socket")) {
#if defined(LWS_USE_UNIX_SOCK) || defined(LWS_WITH_UNIX_SOCK)
info.options |= LWS_SERVER_OPTION_UNIX_SOCK;
info.port = 0; // warmcat/libwebsockets#1985
strncpy(server->socket_path, info.iface, sizeof(server->socket_path) - 1);
if (strlen(socket_owner) > 0) {
info.unix_socket_perms = socket_owner;
}
#else
fprintf(stderr, "libwebsockets is not compiled with UNIX domain socket support");
return -1;
#endif
}
}
#if defined(LWS_OPENSSL_SUPPORT) || defined(LWS_WITH_TLS)
if (ssl) {
info.ssl_cert_filepath = cert_path;
info.ssl_private_key_filepath = key_path;
#ifndef LWS_WITH_MBEDTLS
info.ssl_options_set = SSL_OP_NO_TLSv1 | SSL_OP_NO_TLSv1_1;
#endif
if (strlen(ca_path) > 0) {
info.ssl_ca_filepath = ca_path;
info.options |= LWS_SERVER_OPTION_REQUIRE_VALID_OPENSSL_CLIENT_CERT;
}
info.options |= LWS_SERVER_OPTION_ALLOW_NON_SSL_ON_SSL_PORT | LWS_SERVER_OPTION_REDIRECT_HTTP_TO_HTTPS;
}
#endif
lwsl_notice("ttyd %s (libwebsockets %s)\n", TTYD_VERSION, LWS_LIBRARY_VERSION);
print_config();
// lws custom header requires lower case name, and terminating :
if (server->auth_header != NULL) {
size_t auth_header_len = strlen(server->auth_header);
server->auth_header = xrealloc(server->auth_header, auth_header_len + 2);
strcat(server->auth_header + auth_header_len, ":");
lowercase(server->auth_header);
}
void *foreign_loops[1];
foreign_loops[0] = server->loop;
info.foreign_loops = foreign_loops;
info.options |= LWS_SERVER_OPTION_EXPLICIT_VHOSTS;
context = lws_create_context(&info);
if (context == NULL) {
lwsl_err("libwebsockets context creation failed\n");
return 1;
}
struct lws_vhost *vhost = lws_create_vhost(context, &info);
if (vhost == NULL) {
lwsl_err("libwebsockets vhost creation failed\n");
return 1;
}
int port = lws_get_vhost_listen_port(vhost);
lwsl_notice(" Listening on port: %d\n", port);
if (browser) {
char url[30];
sprintf(url, "%s://localhost:%d", ssl ? "https" : "http", port);
open_uri(url);
}
#define sig_count 2
int sig_nums[] = {SIGINT, SIGTERM};
uv_signal_t signals[sig_count];
for (int i = 0; i < sig_count; i++) {
uv_signal_init(server->loop, &signals[i]);
uv_signal_start(&signals[i], signal_cb, sig_nums[i]);
}
lws_service(context, 0);
for (int i = 0; i < sig_count; i++) {
uv_signal_stop(&signals[i]);
}
#undef sig_count
lws_context_destroy(context);
// cleanup
server_free(server);
return 0;
}