src/afb-hsrv.c

   1 /*
   2  * Copyright (C) 2016, 2017 "IoT.bzh"
   3  * Author: José Bollo <jose.bollo@iot.bzh>
   4  *
   5  * Licensed under the Apache License, Version 2.0 (the "License");
   6  * you may not use this file except in compliance with the License.
   7  * You may obtain a copy of the License at
   8  *
   9  *   http://www.apache.org/licenses/LICENSE-2.0
  10  *
  11  * Unless required by applicable law or agreed to in writing, software
  12  * distributed under the License is distributed on an "AS IS" BASIS,
  13  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14  * See the License for the specific language governing permissions and
  15  * limitations under the License.
  16  */
  17
  18 #define _GNU_SOURCE
  19
  20 #include <stdint.h>
  21 #include <stdio.h>
  22 #include <string.h>
  23 #include <assert.h>
  24 #include <poll.h>
  25 #include <fcntl.h>
  26 #include <errno.h>
  27 #include <sys/stat.h>
  28
  29 #include <microhttpd.h>
  30 #include <systemd/sd-event.h>
  31
  32 #include "afb-method.h"
  33 #include "afb-context.h"
  34 #include "afb-hreq.h"
  35 #include "afb-hsrv.h"
  36 #include <afb/afb-req-itf.h>
  37 #include "verbose.h"
  38 #include "locale-root.h"
  39
  40 #include "afb-common.h"
  41
  42
  43
  44 #define JSON_CONTENT  "application/json"
  45 #define FORM_CONTENT  MHD_HTTP_POST_ENCODING_MULTIPART_FORMDATA
  46
  47
  48 struct hsrv_handler {
  49         struct hsrv_handler *next;
  50         const char *prefix;
  51         size_t length;
  52         int (*handler) (struct afb_hreq *, void *);
  53         void *data;
  54         int priority;
  55 };
  56
  57 struct hsrv_alias {
  58         struct locale_root *root;
  59         int relax;
  60 };
  61
  62 struct afb_hsrv {
  63         unsigned refcount;
  64         struct hsrv_handler *handlers;
  65         struct MHD_Daemon *httpd;
  66         sd_event_source *evsrc;
  67         int in_run;
  68         char *cache_to;
  69 };
  70
  71 static int global_reqids = 0;
  72
  73 static void reply_error(struct MHD_Connection *connection, unsigned int status)
  74 {
  75         struct MHD_Response *response = MHD_create_response_from_buffer(0, NULL, MHD_RESPMEM_PERSISTENT);
  76         MHD_queue_response(connection, status, response);
  77         MHD_destroy_response(response);
  78 }
  79
  80 static int postproc(void *cls,
  81                     enum MHD_ValueKind kind,
  82                     const char *key,
  83                     const char *filename,
  84                     const char *content_type,
  85                     const char *transfer_encoding,
  86                     const char *data,
  87                     uint64_t off,
  88                     size_t size)
  89 {
  90         struct afb_hreq *hreq = cls;
  91         if (filename != NULL)
  92                 return afb_hreq_post_add_file(hreq, key, filename, data, size);
  93         else
  94                 return afb_hreq_post_add(hreq, key, data, size);
  95 }
  96
  97 static int access_handler(
  98                 void *cls,
  99                 struct MHD_Connection *connection,
 100                 const char *url,
 101                 const char *methodstr,
 102                 const char *version,
 103                 const char *upload_data,
 104                 size_t *upload_data_size,
 105                 void **recordreq)
 106 {
 107         int rc;
 108         struct afb_hreq *hreq;
 109         enum afb_method method;
 110         struct afb_hsrv *hsrv;
 111         struct hsrv_handler *iter;
 112         const char *type;
 113
 114         hsrv = cls;
 115         hreq = *recordreq;
 116         if (hreq == NULL) {
 117                 /* get the method */
 118                 method = get_method(methodstr);
 119                 method &= afb_method_get | afb_method_post;
 120                 if (method == afb_method_none) {
 121                         WARNING("Unsupported HTTP operation %s", methodstr);
 122                         reply_error(connection, MHD_HTTP_BAD_REQUEST);
 123                         return MHD_YES;
 124                 }
 125
 126                 /* create the request */
 127                 hreq = calloc(1, sizeof *hreq);
 128                 if (hreq == NULL) {
 129                         ERROR("Can't allocate 'hreq'");
 130                         reply_error(connection, MHD_HTTP_INTERNAL_SERVER_ERROR);
 131                         return MHD_YES;
 132                 }
 133
 134                 /* init the request */
 135                 hreq->refcount = 1;
 136                 hreq->hsrv = hsrv;
 137                 hreq->cacheTimeout = hsrv->cache_to;
 138                 hreq->reqid = ++global_reqids;
 139                 hreq->scanned = 0;
 140                 hreq->suspended = 0;
 141                 hreq->replied = 0;
 142                 hreq->connection = connection;
 143                 hreq->method = method;
 144                 hreq->version = version;
 145                 hreq->lang = MHD_lookup_connection_value(connection, MHD_HEADER_KIND, MHD_HTTP_HEADER_ACCEPT_LANGUAGE);
 146                 hreq->tail = hreq->url = url;
 147                 hreq->lentail = hreq->lenurl = strlen(url);
 148                 *recordreq = hreq;
 149
 150                 /* init the post processing */
 151                 if (method == afb_method_post) {
 152                         type = afb_hreq_get_header(hreq, MHD_HTTP_HEADER_CONTENT_TYPE);
 153                         if (type == NULL) {
 154                                 /* an empty post, let's process it as a get */
 155                                 hreq->method = afb_method_get;
 156                         } else if (strcasestr(type, FORM_CONTENT) != NULL) {
 157                                 hreq->postform = MHD_create_post_processor (connection, 65500, postproc, hreq);
 158                                 if (hreq->postform == NULL) {
 159                                         ERROR("Can't create POST processor");
 160                                         afb_hreq_reply_error(hreq, MHD_HTTP_INTERNAL_SERVER_ERROR);
 161                                 }
 162                                 return MHD_YES;
 163                         } else if (strcasestr(type, JSON_CONTENT) != NULL) {
 164                                 return MHD_YES;
 165                         } else {
 166                                 WARNING("Unsupported media type %s", type);
 167                                 afb_hreq_reply_error(hreq, MHD_HTTP_UNSUPPORTED_MEDIA_TYPE);
 168                                 return MHD_YES;
 169                         }
 170                 }
 171         }
 172
 173         /* process further data */
 174         if (*upload_data_size) {
 175                 if (hreq->postform != NULL) {
 176                         if (!MHD_post_process (hreq->postform, upload_data, *upload_data_size)) {
 177                                 ERROR("error in POST processor");
 178                                 afb_hreq_reply_error(hreq, MHD_HTTP_INTERNAL_SERVER_ERROR);
 179                                 return MHD_YES;
 180                         }
 181                 } else {
 182                         if (!afb_hreq_post_add(hreq, "", upload_data, *upload_data_size)) {
 183                                 afb_hreq_reply_error(hreq, MHD_HTTP_INTERNAL_SERVER_ERROR);
 184                                 return MHD_YES;
 185                         }
 186                 }
 187                 *upload_data_size = 0;
 188                 return MHD_YES;
 189         }
 190
 191         /* flush the data */
 192         if (hreq->postform != NULL) {
 193                 rc = MHD_destroy_post_processor(hreq->postform);
 194                 hreq->postform = NULL;
 195                 if (rc == MHD_NO) {
 196                         ERROR("error detected in POST processing");
 197                         afb_hreq_reply_error(hreq, MHD_HTTP_BAD_REQUEST);
 198                         return MHD_YES;
 199                 }
 200         }
 201
 202         if (hreq->scanned != 0) {
 203                 if (hreq->replied == 0 && hreq->suspended == 0) {
 204                         MHD_suspend_connection (connection);
 205                         hreq->suspended = 1;
 206                 }
 207                 return MHD_YES;
 208         }
 209
 210         /* search an handler for the request */
 211         hreq->scanned = 1;
 212         iter = hsrv->handlers;
 213         while (iter) {
 214                 if (afb_hreq_unprefix(hreq, iter->prefix, iter->length)) {
 215                         if (iter->handler(hreq, iter->data)) {
 216                                 if (hreq->replied == 0 && hreq->suspended == 0) {
 217                                         MHD_suspend_connection (connection);
 218                                         hreq->suspended = 1;
 219                                 }
 220                                 return MHD_YES;
 221                         }
 222                         hreq->tail = hreq->url;
 223                         hreq->lentail = hreq->lenurl;
 224                 }
 225                 iter = iter->next;
 226         }
 227
 228         /* no handler */
 229         WARNING("Unhandled request to %s", hreq->url);
 230         afb_hreq_reply_error(hreq, MHD_HTTP_NOT_FOUND);
 231         return MHD_YES;
 232 }
 233
 234 /* Because of POST call multiple time requestApi we need to free POST handle here */
 235 static void end_handler(void *cls, struct MHD_Connection *connection, void **recordreq,
 236                         enum MHD_RequestTerminationCode toe)
 237 {
 238         struct afb_hreq *hreq;
 239
 240         hreq = *recordreq;
 241         if (hreq) {
 242                 if (hreq->upgrade)
 243                         MHD_suspend_connection (connection);
 244                 afb_hreq_unref(hreq);
 245         }
 246 }
 247
 248 void run_micro_httpd(struct afb_hsrv *hsrv)
 249 {
 250         if (hsrv->in_run != 0)
 251                 hsrv->in_run = 2;
 252         else {
 253                 sd_event_source_set_io_events(hsrv->evsrc, 0);
 254                 do {
 255                         hsrv->in_run = 1;
 256                         MHD_run(hsrv->httpd);
 257                 } while(hsrv->in_run == 2);
 258                 hsrv->in_run = 0;
 259                 sd_event_source_set_io_events(hsrv->evsrc, EPOLLIN);
 260         }
 261 }
 262
 263 static int io_event_callback(sd_event_source *src, int fd, uint32_t revents, void *hsrv)
 264 {
 265         run_micro_httpd(hsrv);
 266         return 0;
 267 }
 268
 269 static int new_client_handler(void *cls, const struct sockaddr *addr, socklen_t addrlen)
 270 {
 271         return MHD_YES;
 272 }
 273
 274 static struct hsrv_handler *new_handler(
 275                 struct hsrv_handler *head,
 276                 const char *prefix,
 277                 int (*handler) (struct afb_hreq *, void *),
 278                 void *data,
 279                 int priority)
 280 {
 281         struct hsrv_handler *link, *iter, *previous;
 282         size_t length;
 283
 284         /* get the length of the prefix without its leading / */
 285         length = strlen(prefix);
 286         while (length && prefix[length - 1] == '/')
 287                 length--;
 288
 289         /* allocates the new link */
 290         link = malloc(sizeof *link);
 291         if (link == NULL)
 292                 return NULL;
 293
 294         /* initialize it */
 295         link->prefix = prefix;
 296         link->length = length;
 297         link->handler = handler;
 298         link->data = data;
 299         link->priority = priority;
 300
 301         /* adds it */
 302         previous = NULL;
 303         iter = head;
 304         while (iter && (priority < iter->priority || (priority == iter->priority && length <= iter->length))) {
 305                 previous = iter;
 306                 iter = iter->next;
 307         }
 308         link->next = iter;
 309         if (previous == NULL)
 310                 return link;
 311         previous->next = link;
 312         return head;
 313 }
 314
 315 static int handle_alias(struct afb_hreq *hreq, void *data)
 316 {
 317         int rc;
 318         struct hsrv_alias *da = data;
 319         struct locale_search *search;
 320
 321         if (hreq->method != afb_method_get) {
 322                 if (da->relax)
 323                         return 0;
 324                 afb_hreq_reply_error(hreq, MHD_HTTP_METHOD_NOT_ALLOWED);
 325                 return 1;
 326         }
 327
 328         search = locale_root_search(da->root, hreq->lang, 0);
 329         rc = afb_hreq_reply_locale_file_if_exist(hreq, search, &hreq->tail[1]);
 330         locale_search_unref(search);
 331         if (rc == 0) {
 332                 if (da->relax)
 333                         return 0;
 334                 afb_hreq_reply_error(hreq, MHD_HTTP_NOT_FOUND);
 335         }
 336         return 1;
 337 }
 338
 339 int afb_hsrv_add_handler(
 340                 struct afb_hsrv *hsrv,
 341                 const char *prefix,
 342                 int (*handler) (struct afb_hreq *, void *),
 343                 void *data,
 344                 int priority)
 345 {
 346         struct hsrv_handler *head;
 347
 348         head = new_handler(hsrv->handlers, prefix, handler, data, priority);
 349         if (head == NULL)
 350                 return 0;
 351         hsrv->handlers = head;
 352         return 1;
 353 }
 354
 355 int afb_hsrv_add_alias_root(struct afb_hsrv *hsrv, const char *prefix, struct locale_root *root, int priority, int relax)
 356 {
 357         struct hsrv_alias *da;
 358
 359         da = malloc(sizeof *da);
 360         if (da != NULL) {
 361                 da->root = root;
 362                 da->relax = relax;
 363                 if (afb_hsrv_add_handler(hsrv, prefix, handle_alias, da, priority)) {
 364                         locale_root_addref(root);
 365                         return 1;
 366                 }
 367                 free(da);
 368         }
 369         return 0;
 370 }
 371
 372 int afb_hsrv_add_alias(struct afb_hsrv *hsrv, const char *prefix, int dirfd, const char *alias, int priority, int relax)
 373 {
 374         struct locale_root *root;
 375         int rc;
 376
 377         root = locale_root_create_at(dirfd, alias);
 378         if (root == NULL) {
 379                 ERROR("can't connect to directory %s: %m", alias);
 380                 rc = 0;
 381         } else {
 382                 rc = afb_hsrv_add_alias_root(hsrv, prefix, root, priority, relax);
 383                 locale_root_unref(root);
 384         }
 385         return rc;
 386 }
 387
 388 int afb_hsrv_set_cache_timeout(struct afb_hsrv *hsrv, int duration)
 389 {
 390         int rc;
 391         char *dur;
 392
 393         rc = asprintf(&dur, "%d", duration);
 394         if (rc < 0)
 395                 return 0;
 396
 397         free(hsrv->cache_to);
 398         hsrv->cache_to = dur;
 399         return 1;
 400 }
 401
 402 int afb_hsrv_start(struct afb_hsrv *hsrv, uint16_t port, unsigned int connection_timeout)
 403 {
 404         sd_event_source *evsrc;
 405         int rc;
 406         struct MHD_Daemon *httpd;
 407         const union MHD_DaemonInfo *info;
 408
 409         httpd = MHD_start_daemon(
 410                 MHD_USE_EPOLL_LINUX_ONLY | MHD_USE_TCP_FASTOPEN | MHD_USE_DEBUG | MHD_USE_SUSPEND_RESUME,
 411                 port,                           /* port */
 412                 new_client_handler, NULL,       /* Tcp Accept call back + extra attribute */
 413                 access_handler, hsrv,   /* Http Request Call back + extra attribute */
 414                 MHD_OPTION_NOTIFY_COMPLETED, end_handler, hsrv,
 415                 MHD_OPTION_CONNECTION_TIMEOUT, connection_timeout,
 416                 MHD_OPTION_END);        /* options-end */
 417
 418         if (httpd == NULL) {
 419                 ERROR("httpStart invalid httpd port: %d", (int)port);
 420                 return 0;
 421         }
 422
 423         info = MHD_get_daemon_info(httpd, MHD_DAEMON_INFO_EPOLL_FD_LINUX_ONLY);
 424         if (info == NULL) {
 425                 MHD_stop_daemon(httpd);
 426                 ERROR("httpStart no pollfd");
 427                 return 0;
 428         }
 429
 430         rc = sd_event_add_io(afb_common_get_event_loop(), &evsrc, info->listen_fd, EPOLLIN, io_event_callback, hsrv);
 431         if (rc < 0) {
 432                 MHD_stop_daemon(httpd);
 433                 errno = -rc;
 434                 ERROR("connection to events for httpd failed");
 435                 return 0;
 436         }
 437
 438         hsrv->httpd = httpd;
 439         hsrv->evsrc = evsrc;
 440         return 1;
 441 }
 442
 443 void afb_hsrv_stop(struct afb_hsrv *hsrv)
 444 {
 445         if (hsrv->evsrc != NULL) {
 446                 sd_event_source_unref(hsrv->evsrc);
 447                 hsrv->evsrc = NULL;
 448         }
 449         if (hsrv->httpd != NULL)
 450                 MHD_stop_daemon(hsrv->httpd);
 451         hsrv->httpd = NULL;
 452 }
 453
 454 struct afb_hsrv *afb_hsrv_create()
 455 {
 456         struct afb_hsrv *result = calloc(1, sizeof(struct afb_hsrv));
 457         if (result != NULL)
 458                 result->refcount = 1;
 459         return result;
 460 }
 461
 462 void afb_hsrv_put(struct afb_hsrv *hsrv)
 463 {
 464         assert(hsrv->refcount != 0);
 465         if (!--hsrv->refcount) {
 466                 afb_hsrv_stop(hsrv);
 467                 free(hsrv);
 468         }
 469 }
 470