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->tail = hreq->url = url;
 146                 hreq->lentail = hreq->lenurl = strlen(url);
 147                 *recordreq = hreq;
 148
 149                 /* init the post processing */
 150                 if (method == afb_method_post) {
 151                         type = afb_hreq_get_header(hreq, MHD_HTTP_HEADER_CONTENT_TYPE);
 152                         if (type == NULL) {
 153                                 /* an empty post, let's process it as a get */
 154                                 hreq->method = afb_method_get;
 155                         } else if (strcasestr(type, FORM_CONTENT) != NULL) {
 156                                 hreq->postform = MHD_create_post_processor (connection, 65500, postproc, hreq);
 157                                 if (hreq->postform == NULL)
 158                                         afb_hreq_reply_error(hreq, MHD_HTTP_INTERNAL_SERVER_ERROR);
 159                                 return MHD_YES;
 160                         } else if (strcasestr(type, JSON_CONTENT) != NULL) {
 161                                 return MHD_YES;
 162                         } else {
 163                                 afb_hreq_reply_error(hreq, MHD_HTTP_UNSUPPORTED_MEDIA_TYPE);
 164                                 return MHD_YES;
 165                         }
 166                 }
 167         }
 168
 169         /* process further data */
 170         if (*upload_data_size) {
 171                 if (hreq->postform != NULL) {
 172                         if (!MHD_post_process (hreq->postform, upload_data, *upload_data_size)) {
 173                                 afb_hreq_reply_error(hreq, MHD_HTTP_INTERNAL_SERVER_ERROR);
 174                                 return MHD_YES;
 175                         }
 176                 } else {
 177                         if (!afb_hreq_post_add(hreq, "", upload_data, *upload_data_size)) {
 178                                 afb_hreq_reply_error(hreq, MHD_HTTP_INTERNAL_SERVER_ERROR);
 179                                 return MHD_YES;
 180                         }
 181                 }
 182                 *upload_data_size = 0;
 183                 return MHD_YES;
 184         }
 185
 186         /* flush the data */
 187         if (hreq->postform != NULL) {
 188                 rc = MHD_destroy_post_processor(hreq->postform);
 189                 hreq->postform = NULL;
 190                 if (rc == MHD_NO) {
 191                         afb_hreq_reply_error(hreq, MHD_HTTP_BAD_REQUEST);
 192                         return MHD_YES;
 193                 }
 194         }
 195
 196         if (hreq->scanned != 0) {
 197                 if (hreq->replied == 0 && hreq->suspended == 0) {
 198                         MHD_suspend_connection (connection);
 199                         hreq->suspended = 1;
 200                 }
 201                 return MHD_YES;
 202         }
 203
 204         /* search an handler for the request */
 205         hreq->scanned = 1;
 206         iter = hsrv->handlers;
 207         while (iter) {
 208                 if (afb_hreq_unprefix(hreq, iter->prefix, iter->length)) {
 209                         if (iter->handler(hreq, iter->data)) {
 210                                 if (hreq->replied == 0 && hreq->suspended == 0) {
 211                                         MHD_suspend_connection (connection);
 212                                         hreq->suspended = 1;
 213                                 }
 214                                 return MHD_YES;
 215                         }
 216                         hreq->tail = hreq->url;
 217                         hreq->lentail = hreq->lenurl;
 218                 }
 219                 iter = iter->next;
 220         }
 221
 222         /* no handler */
 223         afb_hreq_reply_error(hreq, MHD_HTTP_NOT_FOUND);
 224         return MHD_YES;
 225 }
 226
 227 /* Because of POST call multiple time requestApi we need to free POST handle here */
 228 static void end_handler(void *cls, struct MHD_Connection *connection, void **recordreq,
 229                         enum MHD_RequestTerminationCode toe)
 230 {
 231         struct afb_hreq *hreq;
 232
 233         hreq = *recordreq;
 234         if (hreq->upgrade)
 235                 MHD_suspend_connection (connection);
 236         afb_hreq_unref(hreq);
 237 }
 238
 239 void run_micro_httpd(struct afb_hsrv *hsrv)
 240 {
 241         if (hsrv->in_run != 0)
 242                 hsrv->in_run = 2;
 243         else {
 244                 sd_event_source_set_io_events(hsrv->evsrc, 0);
 245                 do {
 246                         hsrv->in_run = 1;
 247                         MHD_run(hsrv->httpd);
 248                 } while(hsrv->in_run == 2);
 249                 hsrv->in_run = 0;
 250                 sd_event_source_set_io_events(hsrv->evsrc, EPOLLIN);
 251         }
 252 }
 253
 254 static int io_event_callback(sd_event_source *src, int fd, uint32_t revents, void *hsrv)
 255 {
 256         run_micro_httpd(hsrv);
 257         return 0;
 258 }
 259
 260 static int new_client_handler(void *cls, const struct sockaddr *addr, socklen_t addrlen)
 261 {
 262         return MHD_YES;
 263 }
 264
 265 static struct hsrv_handler *new_handler(
 266                 struct hsrv_handler *head,
 267                 const char *prefix,
 268                 int (*handler) (struct afb_hreq *, void *),
 269                 void *data,
 270                 int priority)
 271 {
 272         struct hsrv_handler *link, *iter, *previous;
 273         size_t length;
 274
 275         /* get the length of the prefix without its leading / */
 276         length = strlen(prefix);
 277         while (length && prefix[length - 1] == '/')
 278                 length--;
 279
 280         /* allocates the new link */
 281         link = malloc(sizeof *link);
 282         if (link == NULL)
 283                 return NULL;
 284
 285         /* initialize it */
 286         link->prefix = prefix;
 287         link->length = length;
 288         link->handler = handler;
 289         link->data = data;
 290         link->priority = priority;
 291
 292         /* adds it */
 293         previous = NULL;
 294         iter = head;
 295         while (iter && (priority < iter->priority || (priority == iter->priority && length <= iter->length))) {
 296                 previous = iter;
 297                 iter = iter->next;
 298         }
 299         link->next = iter;
 300         if (previous == NULL)
 301                 return link;
 302         previous->next = link;
 303         return head;
 304 }
 305
 306 static int handle_alias(struct afb_hreq *hreq, void *data)
 307 {
 308         int rc;
 309         struct hsrv_alias *da = data;
 310
 311         if (hreq->method != afb_method_get) {
 312                 if (da->relax)
 313                         return 0;
 314                 afb_hreq_reply_error(hreq, MHD_HTTP_METHOD_NOT_ALLOWED);
 315                 return 1;
 316         }
 317
 318         if (!afb_hreq_valid_tail(hreq)) {
 319                 if (da->relax)
 320                         return 0;
 321                 afb_hreq_reply_error(hreq, MHD_HTTP_FORBIDDEN);
 322                 return 1;
 323         }
 324
 325         rc = afb_hreq_reply_file_if_exist(hreq, da->dirfd, &hreq->tail[1]);
 326         if (rc == 0) {
 327                 if (da->relax)
 328                         return 0;
 329                 afb_hreq_reply_error(hreq, MHD_HTTP_NOT_FOUND);
 330         }
 331         return 1;
 332 }
 333
 334 int afb_hsrv_add_handler(
 335                 struct afb_hsrv *hsrv,
 336                 const char *prefix,
 337                 int (*handler) (struct afb_hreq *, void *),
 338                 void *data,
 339                 int priority)
 340 {
 341         struct hsrv_handler *head;
 342
 343         head = new_handler(hsrv->handlers, prefix, handler, data, priority);
 344         if (head == NULL)
 345                 return 0;
 346         hsrv->handlers = head;
 347         return 1;
 348 }
 349
 350 int afb_hsrv_add_alias(struct afb_hsrv *hsrv, const char *prefix, const char *alias, int priority, int relax)
 351 {
 352         struct hsrv_alias *da;
 353         int dirfd;
 354
 355         dirfd = open(alias, O_PATH|O_DIRECTORY);
 356         if (dirfd < 0) {
 357                 /* TODO message */
 358                 return 0;
 359         }
 360         da = malloc(sizeof *da);
 361         if (da != NULL) {
 362                 da->alias = prefix;
 363                 da->directory = alias;
 364                 da->lendir = strlen(da->directory);
 365                 da->dirfd = dirfd;
 366                 da->relax = relax;
 367                 if (afb_hsrv_add_handler(hsrv, prefix, handle_alias, da, priority))
 368                         return 1;
 369                 free(da);
 370         }
 371         close(dirfd);
 372         return 0;
 373 }
 374
 375 int afb_hsrv_set_cache_timeout(struct afb_hsrv *hsrv, int duration)
 376 {
 377         int rc;
 378         char *dur;
 379
 380         rc = asprintf(&dur, "%d", duration);
 381         if (rc < 0)
 382                 return 0;
 383
 384         free(hsrv->cache_to);
 385         hsrv->cache_to = dur;
 386         return 1;
 387 }
 388
 389 int afb_hsrv_start(struct afb_hsrv *hsrv, uint16_t port, unsigned int connection_timeout)
 390 {
 391         sd_event_source *evsrc;
 392         int rc;
 393         struct MHD_Daemon *httpd;
 394         const union MHD_DaemonInfo *info;
 395
 396         httpd = MHD_start_daemon(
 397                 MHD_USE_EPOLL_LINUX_ONLY | MHD_USE_TCP_FASTOPEN | MHD_USE_DEBUG | MHD_USE_SUSPEND_RESUME,
 398                 port,                           /* port */
 399                 new_client_handler, NULL,       /* Tcp Accept call back + extra attribute */
 400                 access_handler, hsrv,   /* Http Request Call back + extra attribute */
 401                 MHD_OPTION_NOTIFY_COMPLETED, end_handler, hsrv,
 402                 MHD_OPTION_CONNECTION_TIMEOUT, connection_timeout,
 403                 MHD_OPTION_END);        /* options-end */
 404
 405         if (httpd == NULL) {
 406                 ERROR("httpStart invalid httpd port: %d", (int)port);
 407                 return 0;
 408         }
 409
 410         info = MHD_get_daemon_info(httpd, MHD_DAEMON_INFO_EPOLL_FD_LINUX_ONLY);
 411         if (info == NULL) {
 412                 MHD_stop_daemon(httpd);
 413                 ERROR("httpStart no pollfd");
 414                 return 0;
 415         }
 416
 417         rc = sd_event_add_io(afb_common_get_event_loop(), &evsrc, info->listen_fd, EPOLLIN, io_event_callback, hsrv);
 418         if (rc < 0) {
 419                 MHD_stop_daemon(httpd);
 420                 errno = -rc;
 421                 ERROR("connection to events for httpd failed");
 422                 return 0;
 423         }
 424
 425         hsrv->httpd = httpd;
 426         hsrv->evsrc = evsrc;
 427         return 1;
 428 }
 429
 430 void afb_hsrv_stop(struct afb_hsrv *hsrv)
 431 {
 432         if (hsrv->evsrc != NULL) {
 433                 sd_event_source_unref(hsrv->evsrc);
 434                 hsrv->evsrc = NULL;
 435         }
 436         if (hsrv->httpd != NULL)
 437                 MHD_stop_daemon(hsrv->httpd);
 438         hsrv->httpd = NULL;
 439 }
 440
 441 struct afb_hsrv *afb_hsrv_create()
 442 {
 443         struct afb_hsrv *result = calloc(1, sizeof(struct afb_hsrv));
 444         if (result != NULL)
 445                 result->refcount = 1;
 446         return result;
 447 }
 448
 449 void afb_hsrv_put(struct afb_hsrv *hsrv)
 450 {
 451         assert(hsrv->refcount != 0);
 452         if (!--hsrv->refcount) {
 453                 afb_hsrv_stop(hsrv);
 454                 free(hsrv);
 455         }
 456 }
 457