Adding upstream version 1.7.4.upstream/1.7.4

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 395 insertions, 0 deletions

diff --git a/src/protocol.c b/src/protocol.c
new file mode 100644
index 0000000..3a53f96
--- /dev/null
+++ b/src/protocol.c
@@ -0,0 +1,395 @@
+#include <errno.h>
+#include <json.h>
+#include <libwebsockets.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "pty.h"
+#include "server.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 json_object *parse_window_size(const char *buf, size_t len, uint16_t *cols, uint16_t *rows) {
+  json_tokener *tok = json_tokener_new();
+  json_object *obj = json_tokener_parse_ex(tok, buf, len);
+  struct json_object *o = NULL;
+
+  if (json_object_object_get_ex(obj, "columns", &o)) *cols = (uint16_t)json_object_get_int(o);
+  if (json_object_object_get_ex(obj, "rows", &o)) *rows = (uint16_t)json_object_get_int(o);
+
+  json_tokener_free(tok);
+  return obj;
+}
+
+static bool check_host_origin(struct lws *wsi) {
+  char buf[256];
+  memset(buf, 0, sizeof(buf));
+  int len = lws_hdr_copy(wsi, buf, (int)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);
+  }
+
+  char host_buf[256];
+  memset(host_buf, 0, sizeof(host_buf));
+  len = lws_hdr_copy(wsi, host_buf, (int)sizeof(host_buf), WSI_TOKEN_HOST);
+
+  return len > 0 && strcasecmp(buf, host_buf) == 0;
+}
+
+static pty_ctx_t *pty_ctx_init(struct pss_tty *pss) {
+  pty_ctx_t *ctx = xmalloc(sizeof(pty_ctx_t));
+  ctx->pss = pss;
+  ctx->ws_closed = false;
+  return ctx;
+}
+
+static void pty_ctx_free(pty_ctx_t *ctx) { free(ctx); }
+
+static void process_read_cb(pty_process *process, pty_buf_t *buf, bool eof) {
+  pty_ctx_t *ctx = (pty_ctx_t *)process->ctx;
+  if (ctx->ws_closed) {
+    pty_buf_free(buf);
+    return;
+  }
+
+  if (eof && !process_running(process))
+    ctx->pss->lws_close_status = process->exit_code == 0 ? 1000 : 1006;
+  else
+    ctx->pss->pty_buf = buf;
+  lws_callback_on_writable(ctx->pss->wsi);
+}
+
+static void process_exit_cb(pty_process *process) {
+  pty_ctx_t *ctx = (pty_ctx_t *)process->ctx;
+  if (ctx->ws_closed) {
+    lwsl_notice("process killed with signal %d, pid: %d\n", process->exit_signal, process->pid);
+    goto done;
+  }
+
+  lwsl_notice("process exited with code %d, pid: %d\n", process->exit_code, process->pid);
+  ctx->pss->process = NULL;
+  ctx->pss->lws_close_status = process->exit_code == 0 ? 1000 : 1006;
+  lws_callback_on_writable(ctx->pss->wsi);
+
+done:
+  pty_ctx_free(ctx);
+}
+
+static char **build_args(struct pss_tty *pss) {
+  int i, n = 0;
+  char **argv = xmalloc((server->argc + pss->argc + 1) * sizeof(char *));
+
+  for (i = 0; i < server->argc; i++) {
+    argv[n++] = server->argv[i];
+  }
+
+  for (i = 0; i < pss->argc; i++) {
+    argv[n++] = pss->args[i];
+  }
+
+  argv[n] = NULL;
+
+  return argv;
+}
+
+static char **build_env(struct pss_tty *pss) {
+  int i = 0, n = 2;
+  char **envp = xmalloc(n * sizeof(char *));
+
+  // TERM
+  envp[i] = xmalloc(36);
+  snprintf(envp[i], 36, "TERM=%s", server->terminal_type);
+  i++;
+
+  // TTYD_USER
+  if (strlen(pss->user) > 0) {
+    envp = xrealloc(envp, (++n) * sizeof(char *));
+    envp[i] = xmalloc(40);
+    snprintf(envp[i], 40, "TTYD_USER=%s", pss->user);
+    i++;
+  }
+
+  envp[i] = NULL;
+
+  return envp;
+}
+
+static bool spawn_process(struct pss_tty *pss, uint16_t columns, uint16_t rows) {
+  pty_process *process = process_init((void *)pty_ctx_init(pss), server->loop, build_args(pss), build_env(pss));
+  if (server->cwd != NULL) process->cwd = strdup(server->cwd);
+  if (columns > 0) process->columns = columns;
+  if (rows > 0) process->rows = rows;
+  if (pty_spawn(process, process_read_cb, process_exit_cb) != 0) {
+    lwsl_err("pty_spawn: %d (%s)\n", errno, strerror(errno));
+    process_free(process);
+    return false;
+  }
+  lwsl_notice("started process, pid: %d\n", process->pid);
+  pss->process = process;
+  lws_callback_on_writable(pss->wsi);
+
+  return true;
+}
+
+static void wsi_output(struct lws *wsi, pty_buf_t *buf) {
+  if (buf == NULL) return;
+  char *message = xmalloc(LWS_PRE + 1 + buf->len);
+  char *ptr = message + LWS_PRE;
+
+  *ptr = OUTPUT;
+  memcpy(ptr + 1, buf->base, buf->len);
+  size_t n = buf->len + 1;
+
+  if (lws_write(wsi, (unsigned char *)ptr, n, LWS_WRITE_BINARY) < n) {
+    lwsl_err("write OUTPUT to WS\n");
+  }
+
+  free(message);
+}
+
+static bool check_auth(struct lws *wsi, struct pss_tty *pss) {
+  if (server->auth_header != NULL) {
+    return lws_hdr_custom_copy(wsi, pss->user, sizeof(pss->user), server->auth_header, strlen(server->auth_header)) > 0;
+  }
+
+  if (server->credential != NULL) {
+    char buf[256];
+    size_t n = lws_hdr_copy(wsi, buf, sizeof(buf), WSI_TOKEN_HTTP_AUTHORIZATION);
+    return n >= 7 && strstr(buf, "Basic ") && !strcmp(buf + 6, server->credential);
+  }
+
+  return true;
+}
+
+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;
+  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;
+      }
+      if (!check_auth(wsi, pss)) 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", pss->path);
+        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->authenticated = false;
+      pss->wsi = wsi;
+      pss->lws_close_status = LWS_CLOSE_STATUS_NOSTATUS;
+
+      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) {
+            pss->args = xrealloc(pss->args, (pss->argc + 1) * sizeof(char *));
+            pss->args[pss->argc] = strdup(&buf[4]);
+            pss->argc++;
+          }
+        }
+      }
+
+      server->client_count++;
+
+      lws_get_peer_simple(lws_get_network_wsi(wsi), pss->address, sizeof(pss->address));
+      lwsl_notice("WS   %s - %s, clients: %d\n", pss->path, pss->address, server->client_count);
+      break;
+
+    case LWS_CALLBACK_SERVER_WRITEABLE:
+      if (!pss->initialized) {
+        if (pss->initial_cmd_index == sizeof(initial_cmds)) {
+          pss->initialized = true;
+          pty_resume(pss->process);
+          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;
+      }
+
+      if (pss->lws_close_status > LWS_CLOSE_STATUS_NOSTATUS) {
+        lws_close_reason(wsi, pss->lws_close_status, NULL, 0);
+        return 1;
+      }
+
+      if (pss->pty_buf != NULL) {
+        wsi_output(wsi, pss->pty_buf);
+        pty_buf_free(pss->pty_buf);
+        pss->pty_buf = NULL;
+        pty_resume(pss->process);
+      }
+      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;
+      }
+
+      switch (command) {
+        case INPUT:
+          if (!server->writable) break;
+          int err = pty_write(pss->process, pty_buf_init(pss->buffer + 1, pss->len - 1));
+          if (err) {
+            lwsl_err("uv_write: %s (%s)\n", uv_err_name(err), uv_strerror(err));
+            return -1;
+          }
+          break;
+        case RESIZE_TERMINAL:
+          if (pss->process == NULL) break;
+          json_object_put(
+              parse_window_size(pss->buffer + 1, pss->len - 1, &pss->process->columns, &pss->process->rows));
+          pty_resize(pss->process);
+          break;
+        case PAUSE:
+          pty_pause(pss->process);
+          break;
+        case RESUME:
+          pty_resume(pss->process);
+          break;
+        case JSON_DATA:
+          if (pss->process != NULL) break;
+          uint16_t columns = 0;
+          uint16_t rows = 0;
+          json_object *obj = parse_window_size(pss->buffer, pss->len, &columns, &rows);
+          if (server->credential != NULL) {
+            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) {
+              json_object_put(obj);
+              lws_close_reason(wsi, LWS_CLOSE_STATUS_POLICY_VIOLATION, NULL, 0);
+              return -1;
+            }
+          }
+          json_object_put(obj);
+          if (!spawn_process(pss, columns, rows)) 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);
+      if (pss->pty_buf != NULL) pty_buf_free(pss->pty_buf);
+      for (int i = 0; i < pss->argc; i++) {
+        free(pss->args[i]);
+      }
+
+      if (pss->process != NULL) {
+        ((pty_ctx_t *)pss->process->ctx)->ws_closed = true;
+        if (process_running(pss->process)) {
+          pty_pause(pss->process);
+          lwsl_notice("killing process, pid: %d\n", pss->process->pid);
+          pty_kill(pss->process, server->sig_code);
+        }
+      }
+
+      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;
+}