src/afb-hsrv.c

   1 /*
   2  * Copyright (C) 2016 "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
  39 #include "afb-common.h"
  40
  41
  42
  43 #define JSON_CONTENT  "application/json"
  44 #define FORM_CONTENT  MHD_HTTP_POST_ENCODING_MULTIPART_FORMDATA
  45
  46
  47 struct hsrv_handler {
  48         struct hsrv_handler *next;
  49         const char *prefix;
  50         size_t length;
  51         int (*handler) (struct afb_hreq *, void *);
  52         void *data;
  53         int priority;
  54 };
  55
  56 struct hsrv_alias {
  57         const char *alias;
  58         const char *directory;
  59         size_t lendir;
  60         int dirfd;
  61         int relax;
  62 };
  63
  64 struct afb_hsrv {
  65         unsigned refcount;
  66         struct hsrv_handler *handlers;
  67         struct MHD_Daemon *httpd;
  68         sd_event_source *evsrc;
  69         int in_run;
  70         char *cache_to;
  71 };
  72
  73 static int global_reqids = 0;
  74
  75 static void reply_error(struct MHD_Connection *connection, unsigned int status)
  76 {
  77         struct MHD_Response *response = MHD_create_response_from_buffer(0, NULL, MHD_RESPMEM_PERSISTENT);
  78         MHD_queue_response(connection, status, response);
  79         MHD_destroy_response(response);
  80 }
  81
  82 static int postproc(void *cls,
  83                     enum MHD_ValueKind kind,
  84                     const char *key,
  85                     const char *filename,
  86                     const char *content_type,
  87                     const char *transfer_encoding,
  88                     const char *data,
  89                     uint64_t off,
  90                     size_t size)
  91 {
  92         struct afb_hreq *hreq = cls;
  93         if (filename != NULL)
  94                 return afb_hreq_post_add_file(hreq, key, filename, data, size);
  95         else
  96                 return afb_hreq_post_add(hreq, key, data, size);
  97 }
  98
  99 static int access_handler(
 100                 void *cls,
 101                 struct MHD_Connection *connection,
 102                 const char *url,
 103                 const char *methodstr,
 104                 const char *version,
 105                 const char *upload_data,
 106                 size_t *upload_data_size,
 107                 void **recordreq)
 108 {
 109         int rc;
 110         struct afb_hreq *hreq;
 111         enum afb_method method;
 112         struct afb_hsrv *hsrv;
 113         struct hsrv_handler *iter;
 114         const char *type;
 115
 116         hsrv = cls;
 117         hreq = *recordreq;
 118         if (hreq == NULL) {
 119                 /* get the method */
 120                 method = get_method(methodstr);
 121                 method &= afb_method_get | afb_method_post;
 122                 if (method == afb_method_none) {
 123                         reply_error(connection, MHD_HTTP_BAD_REQUEST);
 124                         return MHD_YES;
 125                 }
 126
 127                 /* create the request */
 128                 hreq = calloc(1, sizeof *hreq);
 129                 if (hreq == NULL) {
 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 = afb_hreq_get_header(hreq, 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                                         afb_hreq_reply_error(hreq, MHD_HTTP_INTERNAL_SERVER_ERROR);
 160                                 return MHD_YES;
 161                         } else if (strcasestr(type, JSON_CONTENT) != NULL) {
 162                                 return MHD_YES;
 163                         } else {
 164                                 afb_hreq_reply_error(hreq, MHD_HTTP_UNSUPPORTED_MEDIA_TYPE);
 165                                 return MHD_YES;
 166                         }
 167                 }
 168         }
 169
 170         /* process further data */
 171         if (*upload_data_size) {
 172                 if (hreq->postform != NULL) {
 173                         if (!MHD_post_process (hreq->postform, upload_data, *upload_data_size)) {
 174                                 afb_hreq_reply_error(hreq, MHD_HTTP_INTERNAL_SERVER_ERROR);
 175                                 return MHD_YES;
 176                         }
 177                 } else {
 178                         if (!afb_hreq_post_add(hreq, "", upload_data, *upload_data_size)) {
 179                                 afb_hreq_reply_error(hreq, MHD_HTTP_INTERNAL_SERVER_ERROR);
 180                                 return MHD_YES;
 181                         }
 182                 }
 183                 *upload_data_size = 0;
 184                 return MHD_YES;
 185         }
 186
 187         /* flush the data */
 188         if (hreq->postform != NULL) {
 189                 rc = MHD_destroy_post_processor(hreq->postform);
 190                 hreq->postform = NULL;
 191                 if (rc == MHD_NO) {
 192                         afb_hreq_reply_error(hreq, MHD_HTTP_BAD_REQUEST);
 193                         return MHD_YES;
 194                 }
 195         }
 196
 197         if (hreq->scanned != 0) {
 198                 if (hreq->replied == 0 && hreq->suspended == 0) {
 199                         MHD_suspend_connection (connection);
 200                         hreq->suspended = 1;
 201                 }
 202                 return MHD_YES;
 203         }
 204
 205         /* search an handler for the request */
 206         hreq->scanned = 1;
 207         iter = hsrv->handlers;
 208         while (iter) {
 209                 if (afb_hreq_unprefix(hreq, iter->prefix, iter->length)) {
 210                         if (iter->handler(hreq, iter->data)) {
 211                                 if (hreq->replied == 0 && hreq->suspended == 0) {
 212                                         MHD_suspend_connection (connection);
 213                                         hreq->suspended = 1;
 214                                 }
 215                                 return MHD_YES;
 216                         }
 217                         hreq->tail = hreq->url;
 218                         hreq->lentail = hreq->lenurl;
 219                 }
 220                 iter = iter->next;
 221         }
 222
 223         /* no handler */
 224         afb_hreq_reply_error(hreq, MHD_HTTP_NOT_FOUND);
 225         return MHD_YES;
 226 }
 227
 228 /* Because of POST call multiple time requestApi we need to free POST handle here */
 229 static void end_handler(void *cls, struct MHD_Connection *connection, void **recordreq,
 230                         enum MHD_RequestTerminationCode toe)
 231 {
 232         struct afb_hreq *hreq;
 233
 234         hreq = *recordreq;
 235         if (hreq->upgrade)
 236                 MHD_suspend_connection (connection);
 237         afb_hreq_unref(hreq);
 238 }
 239
 240 void run_micro_httpd(struct afb_hsrv *hsrv)
 241 {
 242         if (hsrv->in_run != 0)
 243                 hsrv->in_run = 2;
 244         else {
 245                 sd_event_source_set_io_events(hsrv->evsrc, 0);
 246                 do {
 247                         hsrv->in_run = 1;
 248                         MHD_run(hsrv->httpd);
 249                 } while(hsrv->in_run == 2);
 250                 hsrv->in_run = 0;
 251                 sd_event_source_set_io_events(hsrv->evsrc, EPOLLIN);
 252         }
 253 }
 254
 255 static int io_event_callback(sd_event_source *src, int fd, uint32_t revents, void *hsrv)
 256 {
 257         run_micro_httpd(hsrv);
 258         return 0;
 259 }
 260
 261 static int new_client_handler(void *cls, const struct sockaddr *addr, socklen_t addrlen)
 262 {
 263         return MHD_YES;
 264 }
 265
 266 static struct hsrv_handler *new_handler(
 267                 struct hsrv_handler *head,
 268                 const char *prefix,
 269                 int (*handler) (struct afb_hreq *, void *),
 270                 void *data,
 271                 int priority)
 272 {
 273         struct hsrv_handler *link, *iter, *previous;
 274         size_t length;
 275
 276         /* get the length of the prefix without its leading / */
 277         length = strlen(prefix);
 278         while (length && prefix[length - 1] == '/')
 279                 length--;
 280
 281         /* allocates the new link */
 282         link = malloc(sizeof *link);
 283         if (link == NULL)
 284                 return NULL;
 285
 286         /* initialize it */
 287         link->prefix = prefix;
 288         link->length = length;
 289         link->handler = handler;
 290         link->data = data;
 291         link->priority = priority;
 292
 293         /* adds it */
 294         previous = NULL;
 295         iter = head;
 296         while (iter && (priority < iter->priority || (priority == iter->priority && length <= iter->length))) {
 297                 previous = iter;
 298                 iter = iter->next;
 299         }
 300         link->next = iter;
 301         if (previous == NULL)
 302                 return link;
 303         previous->next = link;
 304         return head;
 305 }
 306
 307 static int handle_alias(struct afb_hreq *hreq, void *data)
 308 {
 309         int rc;
 310         struct hsrv_alias *da = data;
 311
 312         if (hreq->method != afb_method_get) {
 313                 if (da->relax)
 314                         return 0;
 315                 afb_hreq_reply_error(hreq, MHD_HTTP_METHOD_NOT_ALLOWED);
 316                 return 1;
 317         }
 318
 319         if (!afb_hreq_valid_tail(hreq)) {
 320                 if (da->relax)
 321                         return 0;
 322                 afb_hreq_reply_error(hreq, MHD_HTTP_FORBIDDEN);
 323                 return 1;
 324         }
 325
 326         rc = afb_hreq_reply_file_if_exist(hreq, da->dirfd, &hreq->tail[1]);
 327         if (rc == 0) {
 328                 if (da->relax)
 329                         return 0;
 330                 afb_hreq_reply_error(hreq, MHD_HTTP_NOT_FOUND);
 331         }
 332         return 1;
 333 }
 334
 335 int afb_hsrv_add_handler(
 336                 struct afb_hsrv *hsrv,
 337                 const char *prefix,
 338                 int (*handler) (struct afb_hreq *, void *),
 339                 void *data,
 340                 int priority)
 341 {
 342         struct hsrv_handler *head;
 343
 344         head = new_handler(hsrv->handlers, prefix, handler, data, priority);
 345         if (head == NULL)
 346                 return 0;
 347         hsrv->handlers = head;
 348         return 1;
 349 }
 350
 351 int afb_hsrv_add_alias(struct afb_hsrv *hsrv, const char *prefix, const char *alias, int priority, int relax)
 352 {
 353         struct hsrv_alias *da;
 354         int dirfd;
 355
 356         dirfd = open(alias, O_PATH|O_DIRECTORY);
 357         if (dirfd < 0) {
 358                 /* TODO message */
 359                 return 0;
 360         }
 361         da = malloc(sizeof *da);
 362         if (da != NULL) {
 363                 da->alias = prefix;
 364                 da->directory = alias;
 365                 da->lendir = strlen(da->directory);
 366                 da->dirfd = dirfd;
 367                 da->relax = relax;
 368                 if (afb_hsrv_add_handler(hsrv, prefix, handle_alias, da, priority))
 369                         return 1;
 370                 free(da);
 371         }
 372         close(dirfd);
 373         return 0;
 374 }
 375
 376 int afb_hsrv_set_cache_timeout(struct afb_hsrv *hsrv, int duration)
 377 {
 378         int rc;
 379         char *dur;
 380
 381         rc = asprintf(&dur, "%d", duration);
 382         if (rc < 0)
 383                 return 0;
 384
 385         free(hsrv->cache_to);
 386         hsrv->cache_to = dur;
 387         return 1;
 388 }
 389
 390 int afb_hsrv_start(struct afb_hsrv *hsrv, uint16_t port, unsigned int connection_timeout)
 391 {
 392         sd_event_source *evsrc;
 393         int rc;
 394         struct MHD_Daemon *httpd;
 395         const union MHD_DaemonInfo *info;
 396
 397         httpd = MHD_start_daemon(
 398                 MHD_USE_EPOLL_LINUX_ONLY | MHD_USE_TCP_FASTOPEN | MHD_USE_DEBUG | MHD_USE_SUSPEND_RESUME,
 399                 port,                           /* port */
 400                 new_client_handler, NULL,       /* Tcp Accept call back + extra attribute */
 401                 access_handler, hsrv,   /* Http Request Call back + extra attribute */
 402                 MHD_OPTION_NOTIFY_COMPLETED, end_handler, hsrv,
 403                 MHD_OPTION_CONNECTION_TIMEOUT, connection_timeout,
 404                 MHD_OPTION_END);        /* options-end */
 405
 406         if (httpd == NULL) {
 407                 ERROR("httpStart invalid httpd port: %d", (int)port);
 408                 return 0;
 409         }
 410
 411         info = MHD_get_daemon_info(httpd, MHD_DAEMON_INFO_EPOLL_FD_LINUX_ONLY);
 412         if (info == NULL) {
 413                 MHD_stop_daemon(httpd);
 414                 ERROR("httpStart no pollfd");
 415                 return 0;
 416         }
 417
 418         rc = sd_event_add_io(afb_common_get_event_loop(), &evsrc, info->listen_fd, EPOLLIN, io_event_callback, hsrv);
 419         if (rc < 0) {
 420                 MHD_stop_daemon(httpd);
 421                 errno = -rc;
 422                 ERROR("connection to events for httpd failed");
 423                 return 0;
 424         }
 425
 426         hsrv->httpd = httpd;
 427         hsrv->evsrc = evsrc;
 428         return 1;
 429 }
 430
 431 void afb_hsrv_stop(struct afb_hsrv *hsrv)
 432 {
 433         if (hsrv->evsrc != NULL) {
 434                 sd_event_source_unref(hsrv->evsrc);
 435                 hsrv->evsrc = NULL;
 436         }
 437         if (hsrv->httpd != NULL)
 438                 MHD_stop_daemon(hsrv->httpd);
 439         hsrv->httpd = NULL;
 440 }
 441
 442 struct afb_hsrv *afb_hsrv_create()
 443 {
 444         struct afb_hsrv *result = calloc(1, sizeof(struct afb_hsrv));
 445         if (result != NULL)
 446                 result->refcount = 1;
 447         return result;
 448 }
 449
 450 void afb_hsrv_put(struct afb_hsrv *hsrv)
 451 {
 452         assert(hsrv->refcount != 0);
 453         if (!--hsrv->refcount) {
 454                 afb_hsrv_stop(hsrv);
 455                 free(hsrv);
 456         }
 457 }
 458