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authorDaniel Baumann <daniel.baumann@progress-linux.org>2021-02-08 13:16:47 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2021-02-08 13:16:47 +0000
commit4f5226cb7a97f86421a94fcc75c59fe6d709ae02 (patch)
tree1a2cab09cbbc1040650fe21c0a9cef15d2ccb6ee /src/protocol.c
parentInitial commit. (diff)
downloadttyd-4f5226cb7a97f86421a94fcc75c59fe6d709ae02.tar.xz
ttyd-4f5226cb7a97f86421a94fcc75c59fe6d709ae02.zip
Adding upstream version 1.6.3.upstream/1.6.3
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/protocol.c')
-rw-r--r--src/protocol.c460
1 files changed, 460 insertions, 0 deletions
diff --git a/src/protocol.c b/src/protocol.c
new file mode 100644
index 0000000..4b832ab
--- /dev/null
+++ b/src/protocol.c
@@ -0,0 +1,460 @@
+#include <errno.h>
+#include <json.h>
+#include <libwebsockets.h>
+#include <signal.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/wait.h>
+
+#include "server.h"
+#include "terminal.h"
+#include "utils.h"
+
+// initial message list
+static char initial_cmds[] = {SET_WINDOW_TITLE, SET_PREFERENCES};
+
+static int send_initial_message(struct lws *wsi, int index) {
+ unsigned char message[LWS_PRE + 1 + 4096];
+ unsigned char *p = &message[LWS_PRE];
+ char buffer[128];
+ int n = 0;
+
+ char cmd = initial_cmds[index];
+ switch (cmd) {
+ case SET_WINDOW_TITLE:
+ gethostname(buffer, sizeof(buffer) - 1);
+ n = sprintf((char *)p, "%c%s (%s)", cmd, server->command, buffer);
+ break;
+ case SET_PREFERENCES:
+ n = sprintf((char *)p, "%c%s", cmd, server->prefs_json);
+ break;
+ default:
+ break;
+ }
+
+ return lws_write(wsi, p, (size_t)n, LWS_WRITE_BINARY);
+}
+
+static bool parse_window_size(struct pss_tty *pss, int *cols, int *rows) {
+ char json[pss->len];
+ strncpy(json, pss->buffer + 1, pss->len - 1);
+ json[pss->len - 1] = '\0';
+
+ json_object *obj = json_tokener_parse(json);
+ struct json_object *o = NULL;
+
+ if (!json_object_object_get_ex(obj, "columns", &o)) {
+ lwsl_err("columns field not exists, json: %s\n", json);
+ return false;
+ }
+ *cols = json_object_get_int(o);
+ if (!json_object_object_get_ex(obj, "rows", &o)) {
+ lwsl_err("rows field not exists, json: %s\n", json);
+ return false;
+ }
+ *rows = json_object_get_int(o);
+ json_object_put(obj);
+
+ return true;
+}
+
+static bool check_host_origin(struct lws *wsi) {
+ int origin_length = lws_hdr_total_length(wsi, WSI_TOKEN_ORIGIN);
+ char buf[origin_length + 1];
+ memset(buf, 0, sizeof(buf));
+ int len = lws_hdr_copy(wsi, buf, sizeof(buf), WSI_TOKEN_ORIGIN);
+ if (len <= 0) {
+ return false;
+ }
+
+ const char *prot, *address, *path;
+ int port;
+ if (lws_parse_uri(buf, &prot, &address, &port, &path)) return false;
+ if (port == 80 || port == 443) {
+ sprintf(buf, "%s", address);
+ } else {
+ sprintf(buf, "%s:%d", address, port);
+ }
+
+ int host_length = lws_hdr_total_length(wsi, WSI_TOKEN_HOST);
+ if (host_length != strlen(buf)) return false;
+ char host_buf[host_length + 1];
+ memset(host_buf, 0, sizeof(host_buf));
+ len = lws_hdr_copy(wsi, host_buf, sizeof(host_buf), WSI_TOKEN_HOST);
+
+ return len > 0 && strcasecmp(buf, host_buf) == 0;
+}
+
+static void close_cb(uv_handle_t *handle) {
+ struct pty_proc *proc = container_of((uv_pipe_t *)handle, struct pty_proc, pipe);
+ free(proc);
+}
+
+static void pty_proc_free(struct pty_proc *proc) {
+ uv_read_stop((uv_stream_t *)&proc->pipe);
+ close(proc->pty);
+ if (proc->pty_buffer != NULL) {
+ free(proc->pty_buffer);
+ proc->pty_buffer = NULL;
+ }
+ for (int i = 0; i < proc->argc; i++) {
+ free(proc->args[i]);
+ }
+ uv_close((uv_handle_t *)&proc->pipe, close_cb);
+}
+
+static void alloc_cb(uv_handle_t *handle, size_t suggested_size, uv_buf_t *buf) {
+ buf->base = xmalloc(suggested_size);
+ buf->len = suggested_size;
+}
+
+static void read_cb(uv_stream_t *stream, ssize_t nread, const uv_buf_t *buf) {
+ struct pss_tty *pss = (struct pss_tty *)stream->data;
+ struct pty_proc *proc = pss->proc;
+ proc->pty_len = nread;
+
+ uv_read_stop(stream);
+
+ if (nread == UV_ENOBUFS || nread == 0) return;
+ if (nread > 0) {
+ proc->pty_buffer = xmalloc(LWS_PRE + 1 + (size_t)nread);
+ memcpy(proc->pty_buffer + LWS_PRE + 1, buf->base, (size_t)nread);
+ } else {
+ proc->pty_buffer = NULL;
+ if (nread != UV_EOF) {
+ proc->err_count++;
+ lwsl_err("read_cb: %s (%s)\n", uv_err_name(nread), uv_strerror(nread));
+ }
+ }
+ free(buf->base);
+
+ lws_callback_on_writable(pss->wsi);
+}
+
+static void child_cb(uv_signal_t *handle, int signum) {
+ pid_t pid;
+ int stat;
+
+ struct pty_proc *proc;
+ LIST_HEAD(proc, pty_proc) *procs = handle->data;
+ LIST_FOREACH(proc, procs, entry) {
+ do
+ pid = waitpid(proc->pid, &stat, WNOHANG);
+ while (pid == -1 && errno == EINTR);
+
+ if (pid <= 0) continue;
+
+ if (WIFEXITED(stat)) {
+ proc->status = WEXITSTATUS(stat);
+ lwsl_notice("process exited with code %d, pid: %d\n", proc->status, proc->pid);
+ } else if (WIFSIGNALED(stat)) {
+ int sig = WTERMSIG(stat);
+ char sig_name[20];
+
+ proc->status = 128 + sig;
+ get_sig_name(sig, sig_name, sizeof(sig_name));
+ lwsl_notice("process killed with signal %d (%s), pid: %d\n", sig, sig_name, proc->pid);
+ }
+
+ LIST_REMOVE(proc, entry);
+ if (proc->state == STATE_KILL) {
+ pty_proc_free(proc);
+ } else {
+ proc->state = STATE_EXIT;
+ }
+ }
+}
+
+static int spawn_process(struct pss_tty *pss) {
+ struct pty_proc *proc = pss->proc;
+ // append url args to arguments
+ char *argv[server->argc + proc->argc + 1];
+ int i, n = 0;
+ for (i = 0; i < server->argc; i++) {
+ argv[n++] = server->argv[i];
+ }
+ for (i = 0; i < proc->argc; i++) {
+ argv[n++] = proc->args[i];
+ }
+ argv[n] = NULL;
+
+ uv_signal_start(&server->watcher, child_cb, SIGCHLD);
+
+ // ensure the lws socket fd close-on-exec
+ fd_set_cloexec(lws_get_socket_fd(pss->wsi));
+
+ // create process with pseudo-tty
+ proc->pid = pty_fork(&proc->pty, argv[0], argv, server->terminal_type);
+ if (proc->pid < 0) {
+ lwsl_err("pty_fork: %d (%s)\n", errno, strerror(errno));
+ return 1;
+ }
+
+ lwsl_notice("started process, pid: %d\n", proc->pid);
+
+ proc->pipe.data = pss;
+ uv_pipe_open(&proc->pipe, proc->pty);
+
+ lws_callback_on_writable(pss->wsi);
+
+ return 0;
+}
+
+static void kill_process(struct pty_proc *proc) {
+ if (proc->pid <= 0) return;
+
+ pid_t pid = proc->pid;
+ int sig = server->sig_code;
+ char *sig_name = server->sig_name;
+
+ lwsl_notice("killing process %d with signal: %d (%s)\n", pid, sig, sig_name);
+ int pgid = getpgid(pid);
+ if (uv_kill(pgid > 0 ? -pgid : pid, sig) != 0) {
+ lwsl_err("kill: %d, errno: %d (%s)\n", pid, errno, strerror(errno));
+ }
+}
+
+static void write_cb(uv_write_t *req, int status) {
+ if (status != 0) lwsl_warn("uv_write callback returned status: %d\n", status);
+ free(req->data);
+ free(req);
+}
+
+int callback_tty(struct lws *wsi, enum lws_callback_reasons reason, void *user, void *in,
+ size_t len) {
+ struct pss_tty *pss = (struct pss_tty *)user;
+ struct pty_proc *proc;
+ char buf[256];
+ size_t n = 0;
+
+ switch (reason) {
+ case LWS_CALLBACK_FILTER_PROTOCOL_CONNECTION:
+ if (server->once && server->client_count > 0) {
+ lwsl_warn("refuse to serve WS client due to the --once option.\n");
+ return 1;
+ }
+ if (server->max_clients > 0 && server->client_count == server->max_clients) {
+ lwsl_warn("refuse to serve WS client due to the --max-clients option.\n");
+ return 1;
+ }
+
+ n = lws_hdr_copy(wsi, pss->path, sizeof(pss->path), WSI_TOKEN_GET_URI);
+#if defined(LWS_ROLE_H2)
+ if (n <= 0) n = lws_hdr_copy(wsi, pss->path, sizeof(pss->path), WSI_TOKEN_HTTP_COLON_PATH);
+#endif
+ if (strncmp(pss->path, endpoints.ws, n) != 0) {
+ lwsl_warn("refuse to serve WS client for illegal ws path: %s\n", buf);
+ return 1;
+ }
+
+ if (server->check_origin && !check_host_origin(wsi)) {
+ lwsl_warn(
+ "refuse to serve WS client from different origin due to the "
+ "--check-origin option.\n");
+ return 1;
+ }
+ break;
+
+ case LWS_CALLBACK_ESTABLISHED:
+ pss->initialized = false;
+ pss->initial_cmd_index = 0;
+ pss->authenticated = false;
+ pss->wsi = wsi;
+ pss->buffer = NULL;
+
+ pss->proc = proc = xmalloc(sizeof(struct pty_proc));
+ memset(proc, 0, sizeof(struct pty_proc));
+ proc->status = -1;
+ proc->state = STATE_INIT;
+ uv_pipe_init(server->loop, &proc->pipe, 0);
+
+ if (server->url_arg) {
+ while (lws_hdr_copy_fragment(wsi, buf, sizeof(buf), WSI_TOKEN_HTTP_URI_ARGS, n++) > 0) {
+ if (strncmp(buf, "arg=", 4) == 0) {
+ proc->args = xrealloc(proc->args, (proc->argc + 1) * sizeof(char *));
+ proc->args[proc->argc] = strdup(&buf[4]);
+ proc->argc++;
+ }
+ }
+ }
+
+ LIST_INSERT_HEAD(&server->procs, proc, entry);
+ server->client_count++;
+
+#if LWS_LIBRARY_VERSION_NUMBER >= 2004000
+ lws_get_peer_simple(lws_get_network_wsi(wsi), pss->address, sizeof(pss->address));
+#else
+ char name[100];
+ lws_get_peer_addresses(wsi, lws_get_socket_fd(wsi), name, sizeof(name), pss->address,
+ sizeof(pss->address));
+#endif
+ lwsl_notice("WS %s - %s, clients: %d\n", pss->path, pss->address, server->client_count);
+ break;
+
+ case LWS_CALLBACK_SERVER_WRITEABLE:
+ proc = pss->proc;
+ if (!pss->initialized) {
+ if (pss->initial_cmd_index == sizeof(initial_cmds)) {
+ pss->initialized = true;
+ uv_read_start((uv_stream_t *)&proc->pipe, alloc_cb, read_cb);
+ break;
+ }
+ if (send_initial_message(wsi, pss->initial_cmd_index) < 0) {
+ lwsl_err("failed to send initial message, index: %d\n", pss->initial_cmd_index);
+ lws_close_reason(wsi, LWS_CLOSE_STATUS_UNEXPECTED_CONDITION, NULL, 0);
+ return -1;
+ }
+ pss->initial_cmd_index++;
+ lws_callback_on_writable(wsi);
+ break;
+ }
+
+ // read error or client exited, close connection
+ if (proc->status == 0 || proc->pty_len == UV_EOF) {
+ lws_close_reason(wsi, LWS_CLOSE_STATUS_NORMAL, NULL, 0);
+ return 1;
+ } else if (proc->status > 0 || (proc->pty_len < 0 && proc->err_count == MAX_READ_RETRY)) {
+ lws_close_reason(wsi, LWS_CLOSE_STATUS_UNEXPECTED_CONDITION, NULL, 0);
+ return -1;
+ }
+
+ if (proc->pty_buffer != NULL && proc->pty_len > 0) {
+ proc->pty_buffer[LWS_PRE] = OUTPUT;
+ n = (size_t)(proc->pty_len + 1);
+ if (lws_write(wsi, (unsigned char *)proc->pty_buffer + LWS_PRE, n, LWS_WRITE_BINARY) < n) {
+ lwsl_err("write OUTPUT to WS\n");
+ }
+ free(proc->pty_buffer);
+ proc->pty_buffer = NULL;
+ }
+
+ uv_read_start((uv_stream_t *)&proc->pipe, alloc_cb, read_cb);
+ break;
+
+ case LWS_CALLBACK_RECEIVE:
+ if (pss->buffer == NULL) {
+ pss->buffer = xmalloc(len);
+ pss->len = len;
+ memcpy(pss->buffer, in, len);
+ } else {
+ pss->buffer = xrealloc(pss->buffer, pss->len + len);
+ memcpy(pss->buffer + pss->len, in, len);
+ pss->len += len;
+ }
+
+ const char command = pss->buffer[0];
+
+ // check auth
+ if (server->credential != NULL && !pss->authenticated && command != JSON_DATA) {
+ lwsl_warn("WS client not authenticated\n");
+ return 1;
+ }
+
+ // check if there are more fragmented messages
+ if (lws_remaining_packet_payload(wsi) > 0 || !lws_is_final_fragment(wsi)) {
+ return 0;
+ }
+
+ proc = pss->proc;
+ switch (command) {
+ case INPUT:
+ if (proc->pty == 0) break;
+ if (server->readonly) break;
+
+ char *data = xmalloc(pss->len - 1);
+ memcpy(data, pss->buffer + 1, pss->len - 1);
+
+ uv_buf_t b = {data, pss->len - 1};
+ uv_write_t *req = xmalloc(sizeof(uv_write_t));
+ req->data = data;
+
+ int err = uv_write(req, (uv_stream_t *)&proc->pipe, &b, 1, write_cb);
+ if (err) {
+ lwsl_err("uv_write: %s (%s)\n", uv_err_name(err), uv_strerror(err));
+ return -1;
+ }
+ break;
+ case RESIZE_TERMINAL: {
+ int cols, rows;
+ if (parse_window_size(pss, &cols, &rows)) {
+ if (pty_resize(proc->pty, cols, rows) < 0) {
+ lwsl_err("pty_resize: %d (%s)\n", errno, strerror(errno));
+ }
+ }
+ } break;
+ case PAUSE:
+ if (proc->state == STATE_INIT) {
+ uv_read_stop((uv_stream_t *)&proc->pipe);
+ proc->state = STATE_PAUSE;
+ }
+ break;
+ case RESUME:
+ if (proc->state == STATE_PAUSE) {
+ uv_read_start((uv_stream_t *)&proc->pipe, alloc_cb, read_cb);
+ proc->state = STATE_INIT;
+ }
+ break;
+ case JSON_DATA:
+ if (proc->pid > 0) break;
+ if (server->credential != NULL) {
+ json_object *obj = json_tokener_parse(pss->buffer);
+ struct json_object *o = NULL;
+ if (json_object_object_get_ex(obj, "AuthToken", &o)) {
+ const char *token = json_object_get_string(o);
+ if (token != NULL && !strcmp(token, server->credential))
+ pss->authenticated = true;
+ else
+ lwsl_warn("WS authentication failed with token: %s\n", token);
+ }
+ if (!pss->authenticated) {
+ lws_close_reason(wsi, LWS_CLOSE_STATUS_POLICY_VIOLATION, NULL, 0);
+ return -1;
+ }
+ }
+ if (spawn_process(pss) != 0) return 1;
+ break;
+ default:
+ lwsl_warn("ignored unknown message type: %c\n", command);
+ break;
+ }
+
+ if (pss->buffer != NULL) {
+ free(pss->buffer);
+ pss->buffer = NULL;
+ }
+ break;
+
+ case LWS_CALLBACK_CLOSED:
+ if (pss->wsi == NULL) break;
+
+ server->client_count--;
+ lwsl_notice("WS closed from %s, clients: %d\n", pss->address, server->client_count);
+ if (pss->buffer != NULL) {
+ free(pss->buffer);
+ }
+
+ proc = pss->proc;
+ if (proc->state == STATE_EXIT) {
+ pty_proc_free(proc);
+ } else {
+ proc->state = STATE_KILL;
+ uv_read_stop((uv_stream_t *)&proc->pipe);
+ kill_process(proc);
+ }
+
+ if (server->once && server->client_count == 0) {
+ lwsl_notice("exiting due to the --once option.\n");
+ force_exit = true;
+ lws_cancel_service(context);
+ exit(0);
+ }
+ break;
+
+ default:
+ break;
+ }
+
+ return 0;
+}