source4/web_server/web_server.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    web server startup
   5
   6    Copyright (C) Andrew Tridgell 2005
   7    Copyright (C) Jelmer Vernooij 2008
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 3 of the License, or
  12    (at your option) any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  21 */
  22
  23 #include "includes.h"
  24 #include "web_server/web_server.h"
  25 #include "../lib/util/dlinklist.h"
  26 #include "lib/tls/tls.h"
  27 #include "lib/events/events.h"
  28 #include "lib/socket/netif.h"
  29 #include "param/param.h"
  30
  31 NTSTATUS server_service_web_init(TALLOC_CTX *);
  32
  33 /* don't allow connections to hang around forever */
  34 #define HTTP_TIMEOUT 120
  35
  36 /*
  37   destroy a web connection
  38 */
  39 static int websrv_destructor(struct websrv_context *web)
  40 {
  41         return 0;
  42 }
  43
  44 /*
  45   called when a connection times out. This prevents a stuck connection
  46   from hanging around forever
  47 */
  48 static void websrv_timeout(struct tevent_context *event_context,
  49                            struct tevent_timer *te,
  50                            struct timeval t, void *private_data)
  51 {
  52         struct websrv_context *web = talloc_get_type_abort(private_data, struct websrv_context);
  53         struct stream_connection *conn = web->conn;
  54         web->conn = NULL;
  55         /* TODO: send a message to any running esp context on this connection
  56            to stop running */
  57         stream_terminate_connection(conn, "websrv_timeout: timed out");
  58 }
  59
  60 /*
  61   setup for a raw http level error
  62 */
  63 void http_error(struct websrv_context *web, const char *status, const char *info)
  64 {
  65         char *s;
  66         s = talloc_asprintf(web,"<HTML><HEAD><TITLE>Error %s</TITLE></HEAD><BODY><H1>Error %s</H1><pre>%s</pre><p></BODY></HTML>\r\n\r\n",
  67                             status, status, info);
  68         if (s == NULL) {
  69                 stream_terminate_connection(web->conn, "http_error: out of memory");
  70                 return;
  71         }
  72         websrv_output_headers(web, status, NULL);
  73         websrv_output(web, s, strlen(s));
  74 }
  75
  76 void websrv_output_headers(struct websrv_context *web, const char *status, struct http_header *headers)
  77 {
  78         char *s;
  79         DATA_BLOB b;
  80         struct http_header *hdr;
  81
  82         s = talloc_asprintf(web, "HTTP/1.0 %s\r\n", status);
  83         if (s == NULL) return;
  84         for (hdr = headers; hdr; hdr = hdr->next) {
  85                 s = talloc_asprintf_append_buffer(s, "%s: %s\r\n", hdr->name, hdr->value);
  86         }
  87
  88         s = talloc_asprintf_append_buffer(s, "\r\n");
  89
  90         b = web->output.content;
  91         web->output.content = data_blob_string_const(s);
  92         websrv_output(web, b.data, b.length);
  93         data_blob_free(&b);
  94 }
  95
  96 void websrv_output(struct websrv_context *web, const void *data, size_t length)
  97 {
  98         data_blob_append(web, &web->output.content, data, length);
  99         TEVENT_FD_NOT_READABLE(web->conn->event.fde);
 100         TEVENT_FD_WRITEABLE(web->conn->event.fde);
 101         web->output.output_pending = true;
 102 }
 103
 104
 105 /*
 106   parse one line of header input
 107 */
 108 NTSTATUS http_parse_header(struct websrv_context *web, const char *line)
 109 {
 110         if (line[0] == 0) {
 111                 web->input.end_of_headers = true;
 112         } else if (strncasecmp(line,"GET ", 4)==0) {
 113                 web->input.url = talloc_strndup(web, &line[4], strcspn(&line[4], " \t"));
 114         } else if (strncasecmp(line,"POST ", 5)==0) {
 115                 web->input.post_request = true;
 116                 web->input.url = talloc_strndup(web, &line[5], strcspn(&line[5], " \t"));
 117         } else if (strchr(line, ':') == NULL) {
 118                 http_error(web, "400 Bad request", "This server only accepts GET and POST requests");
 119                 return NT_STATUS_INVALID_PARAMETER;
 120         } else if (strncasecmp(line, "Content-Length: ", 16)==0) {
 121                 web->input.content_length = strtoul(&line[16], NULL, 10);
 122         } else {
 123                 struct http_header *hdr = talloc_zero(web, struct http_header);
 124                 char *colon = strchr(line, ':');
 125                 if (colon == NULL) {
 126                         http_error(web, "500 Internal Server Error", "invalidly formatted header");
 127                         return NT_STATUS_INVALID_PARAMETER;
 128                 }
 129
 130                 hdr->name = talloc_strndup(hdr, line, colon-line);
 131                 hdr->value = talloc_strdup(hdr, colon+1);
 132                 DLIST_ADD(web->input.headers, hdr);
 133         }
 134
 135         /* ignore all other headers for now */
 136         return NT_STATUS_OK;
 137 }
 138
 139 /*
 140   called when a web connection becomes readable
 141 */
 142 static void websrv_recv(struct stream_connection *conn, uint16_t flags)
 143 {
 144         struct web_server_data *wdata;
 145         struct websrv_context *web = talloc_get_type_abort(conn->private_data,
 146                                                            struct websrv_context);
 147         NTSTATUS status;
 148         uint8_t buf[1024];
 149         size_t nread;
 150         uint8_t *p;
 151         DATA_BLOB b;
 152
 153         /* not the most efficient http parser ever, but good enough for us */
 154         status = socket_recv(conn->socket, buf, sizeof(buf), &nread);
 155         if (NT_STATUS_IS_ERR(status)) goto failed;
 156         if (!NT_STATUS_IS_OK(status)) return;
 157
 158         if (!data_blob_append(web, &web->input.partial, buf, nread))
 159                 goto failed;
 160
 161         /* parse any lines that are available */
 162         b = web->input.partial;
 163         while (!web->input.end_of_headers &&
 164                (p=(uint8_t *)memchr(b.data, '\n', b.length))) {
 165                 const char *line = (const char *)b.data;
 166                 *p = 0;
 167                 if (p != b.data && p[-1] == '\r') {
 168                         p[-1] = 0;
 169                 }
 170                 status = http_parse_header(web, line);
 171                 if (!NT_STATUS_IS_OK(status)) return;
 172                 b.length -= (p - b.data) + 1;
 173                 b.data = p+1;
 174         }
 175
 176         /* keep any remaining bytes in web->input.partial */
 177         if (b.length == 0) {
 178                 b.data = NULL;
 179         }
 180         b = data_blob_talloc(web, b.data, b.length);
 181         data_blob_free(&web->input.partial);
 182         web->input.partial = b;
 183
 184         /* we finish when we have both the full headers (terminated by
 185            a blank line) and any post data, as indicated by the
 186            content_length */
 187         if (web->input.end_of_headers &&
 188             web->input.partial.length >= web->input.content_length) {
 189                 if (web->input.partial.length > web->input.content_length) {
 190                         web->input.partial.data[web->input.content_length] = 0;
 191                 }
 192                 TEVENT_FD_NOT_READABLE(web->conn->event.fde);
 193
 194                 /* the reference/unlink code here is quite subtle. It
 195                  is needed because the rendering of the web-pages, and
 196                  in particular the esp/ejs backend, is semi-async.  So
 197                  we could well end up in the connection timeout code
 198                  while inside http_process_input(), but we must not
 199                  destroy the stack variables being used by that
 200                  rendering process when we handle the timeout. */
 201                 if (!talloc_reference(web->task, web)) goto failed;
 202                 wdata = talloc_get_type_abort(web->task->private_data, struct web_server_data);
 203                 if (wdata == NULL) goto failed;
 204                 wdata->http_process_input(wdata, web);
 205                 talloc_unlink(web->task, web);
 206         }
 207         return;
 208
 209 failed:
 210         stream_terminate_connection(conn, "websrv_recv: failed");
 211 }
 212
 213
 214
 215 /*
 216   called when a web connection becomes writable
 217 */
 218 static void websrv_send(struct stream_connection *conn, uint16_t flags)
 219 {
 220         struct websrv_context *web = talloc_get_type_abort(conn->private_data,
 221                                                            struct websrv_context);
 222         NTSTATUS status;
 223         size_t nsent;
 224         DATA_BLOB b;
 225
 226         b = web->output.content;
 227         b.data += web->output.nsent;
 228         b.length -= web->output.nsent;
 229
 230         status = socket_send(conn->socket, &b, &nsent);
 231         if (NT_STATUS_IS_ERR(status)) {
 232                 stream_terminate_connection(web->conn, "socket_send: failed");
 233                 return;
 234         }
 235         if (!NT_STATUS_IS_OK(status)) {
 236                 return;
 237         }
 238
 239         web->output.nsent += nsent;
 240
 241         if (web->output.content.length == web->output.nsent) {
 242                 stream_terminate_connection(web->conn, "websrv_send: finished sending");
 243         }
 244 }
 245
 246 /*
 247   establish a new connection to the web server
 248 */
 249 static void websrv_accept(struct stream_connection *conn)
 250 {
 251         struct task_server *task = talloc_get_type_abort(conn->private_data, struct task_server);
 252         struct web_server_data *wdata = talloc_get_type_abort(task->private_data, struct web_server_data);
 253         struct websrv_context *web;
 254         struct socket_context *tls_socket;
 255
 256         web = talloc_zero(conn, struct websrv_context);
 257         if (web == NULL) goto failed;
 258
 259         web->task = wdata->task;
 260         web->conn = conn;
 261         conn->private_data = web;
 262         talloc_set_destructor(web, websrv_destructor);
 263
 264         tevent_add_timer(conn->event.ctx, web,
 265                         timeval_current_ofs(HTTP_TIMEOUT, 0),
 266                         websrv_timeout, web);
 267
 268         /* Overwrite the socket with a (possibly) TLS socket */
 269         tls_socket = tls_init_server(wdata->tls_params, conn->socket,
 270                                      conn->event.fde, "GPHO");
 271         /* We might not have TLS, or it might not have initilised */
 272         if (tls_socket) {
 273                 talloc_unlink(conn, conn->socket);
 274                 talloc_steal(conn, tls_socket);
 275                 conn->socket = tls_socket;
 276         } else {
 277                 DEBUG(3, ("TLS not available for web_server connections\n"));
 278         }
 279
 280         return;
 281
 282 failed:
 283         talloc_free(conn);
 284 }
 285
 286
 287 static const struct stream_server_ops web_stream_ops = {
 288         .name                   = "web",
 289         .accept_connection      = websrv_accept,
 290         .recv_handler           = websrv_recv,
 291         .send_handler           = websrv_send,
 292 };
 293
 294 /*
 295   startup the web server task
 296 */
 297 static void websrv_task_init(struct task_server *task)
 298 {
 299         NTSTATUS status;
 300         uint16_t port = lpcfg_web_port(task->lp_ctx);
 301         struct web_server_data *wdata;
 302
 303         task_server_set_title(task, "task[websrv]");
 304
 305         /* startup the Python processor - unfortunately we can't do this
 306            per connection as that wouldn't allow for session variables */
 307         wdata = talloc_zero(task, struct web_server_data);
 308         if (wdata == NULL) goto failed;
 309
 310         wdata->task = task;
 311         task->private_data = wdata;
 312
 313         if (lpcfg_interfaces(task->lp_ctx) && lpcfg_bind_interfaces_only(task->lp_ctx)) {
 314                 int num_interfaces;
 315                 int i;
 316                 struct interface *ifaces;
 317
 318                 load_interface_list(NULL, task->lp_ctx, &ifaces);
 319
 320                 num_interfaces = iface_list_count(ifaces);
 321                 for(i = 0; i < num_interfaces; i++) {
 322                         const char *address = iface_list_n_ip(ifaces, i);
 323                         status = stream_setup_socket(task,
 324                                                      task->event_ctx,
 325                                                      task->lp_ctx,
 326                                                      task->model_ops,
 327                                                      &web_stream_ops,
 328                                                      "ip", address,
 329                                                      &port,
 330                                                      lpcfg_socket_options(task->lp_ctx),
 331                                                      task,
 332                                                      task->process_context);
 333                         if (!NT_STATUS_IS_OK(status)) goto failed;
 334                 }
 335
 336                 talloc_free(ifaces);
 337         } else {
 338                 char **wcard;
 339                 int i;
 340                 wcard = iface_list_wildcard(task);
 341                 if (wcard == NULL) {
 342                         DEBUG(0,("No wildcard addresses available\n"));
 343                         goto failed;
 344                 }
 345                 for (i=0; wcard[i]; i++) {
 346                         status = stream_setup_socket(task, task->event_ctx,
 347                                                      task->lp_ctx,
 348                                                      task->model_ops,
 349                                                      &web_stream_ops,
 350                                                      "ip", wcard[i],
 351                                                      &port, lpcfg_socket_options(task->lp_ctx),
 352                                                      wdata,
 353                                                      task->process_context);
 354                         if (!NT_STATUS_IS_OK(status)) goto failed;
 355                 }
 356                 talloc_free(wcard);
 357         }
 358
 359         wdata->tls_params = tls_initialise(wdata, task->lp_ctx);
 360         if (wdata->tls_params == NULL) goto failed;
 361
 362         if (!wsgi_initialize(wdata)) goto failed;
 363
 364
 365         return;
 366
 367 failed:
 368         task_server_terminate(task, "websrv_task_init: failed to startup web server task", true);
 369 }
 370
 371
 372 /* called at smbd startup - register ourselves as a server service */
 373 NTSTATUS server_service_web_init(TALLOC_CTX *ctx)
 374 {
 375         struct service_details details = {
 376                 .inhibit_fork_on_accept = true,
 377                 .inhibit_pre_fork = true
 378         };
 379         return register_server_service(ctx, "web", websrv_task_init, &details);
 380 }