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 };
  62
  63 struct afb_hsrv {
  64         unsigned refcount;
  65         struct hsrv_handler *handlers;
  66         struct MHD_Daemon *httpd;
  67         sd_event_source *evsrc;
  68         int in_run;
  69         char *cache_to;
  70 };
  71
  72 static int global_reqids = 0;
  73
  74 static void reply_error(struct MHD_Connection *connection, unsigned int status)
  75 {
  76         struct MHD_Response *response = MHD_create_response_from_buffer(0, NULL, MHD_RESPMEM_PERSISTENT);
  77         MHD_queue_response(connection, status, response);
  78         MHD_destroy_response(response);
  79 }
  80
  81 static int postproc(void *cls,
  82                     enum MHD_ValueKind kind,
  83                     const char *key,
  84                     const char *filename,
  85                     const char *content_type,
  86                     const char *transfer_encoding,
  87                     const char *data,
  88                     uint64_t off,
  89                     size_t size)
  90 {
  91         struct afb_hreq *hreq = cls;
  92         if (filename != NULL)
  93                 return afb_hreq_post_add_file(hreq, key, filename, data, size);
  94         else
  95                 return afb_hreq_post_add(hreq, key, data, size);
  96 }
  97
  98 static int access_handler(
  99                 void *cls,
 100                 struct MHD_Connection *connection,
 101                 const char *url,
 102                 const char *methodstr,
 103                 const char *version,
 104                 const char *upload_data,
 105                 size_t *upload_data_size,
 106                 void **recordreq)
 107 {
 108         int rc;
 109         struct afb_hreq *hreq;
 110         enum afb_method method;
 111         struct afb_hsrv *hsrv;
 112         struct hsrv_handler *iter;
 113         const char *type;
 114
 115         hsrv = cls;
 116         hreq = *recordreq;
 117         if (hreq == NULL) {
 118                 /* get the method */
 119                 method = get_method(methodstr);
 120                 method &= afb_method_get | afb_method_post;
 121                 if (method == afb_method_none) {
 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                         reply_error(connection, MHD_HTTP_INTERNAL_SERVER_ERROR);
 130                         return MHD_YES;
 131                 }
 132
 133                 /* init the request */
 134                 hreq->refcount = 1;
 135                 hreq->hsrv = hsrv;
 136                 hreq->cacheTimeout = hsrv->cache_to;
 137                 hreq->reqid = ++global_reqids;
 138                 hreq->scanned = 0;
 139                 hreq->suspended = 0;
 140                 hreq->replied = 0;
 141                 hreq->connection = connection;
 142                 hreq->method = method;
 143                 hreq->version = version;
 144                 hreq->tail = hreq->url = url;
 145                 hreq->lentail = hreq->lenurl = strlen(url);
 146                 *recordreq = hreq;
 147
 148                 /* init the post processing */
 149                 if (method == afb_method_post) {
 150                         type = afb_hreq_get_header(hreq, MHD_HTTP_HEADER_CONTENT_TYPE);
 151                         if (type == NULL) {
 152                                 /* an empty post, let's process it as a get */
 153                                 hreq->method = afb_method_get;
 154                         } else if (strcasestr(type, FORM_CONTENT) != NULL) {
 155                                 hreq->postform = MHD_create_post_processor (connection, 65500, postproc, hreq);
 156                                 if (hreq->postform == NULL)
 157                                         afb_hreq_reply_error(hreq, MHD_HTTP_INTERNAL_SERVER_ERROR);
 158                                 return MHD_YES;
 159                         } else if (strcasestr(type, JSON_CONTENT) != NULL) {
 160                                 return MHD_YES;
 161                         } else {
 162                                 afb_hreq_reply_error(hreq, MHD_HTTP_UNSUPPORTED_MEDIA_TYPE);
 163                                 return MHD_YES;
 164                         }
 165                 }
 166         }
 167
 168         /* process further data */
 169         if (*upload_data_size) {
 170                 if (hreq->postform != NULL) {
 171                         if (!MHD_post_process (hreq->postform, upload_data, *upload_data_size)) {
 172                                 afb_hreq_reply_error(hreq, MHD_HTTP_INTERNAL_SERVER_ERROR);
 173                                 return MHD_YES;
 174                         }
 175                 } else {
 176                         if (!afb_hreq_post_add(hreq, "", upload_data, *upload_data_size)) {
 177                                 afb_hreq_reply_error(hreq, MHD_HTTP_INTERNAL_SERVER_ERROR);
 178                                 return MHD_YES;
 179                         }
 180                 }
 181                 *upload_data_size = 0;
 182                 return MHD_YES;
 183         }
 184
 185         /* flush the data */
 186         if (hreq->postform != NULL) {
 187                 rc = MHD_destroy_post_processor(hreq->postform);
 188                 hreq->postform = NULL;
 189                 if (rc == MHD_NO) {
 190                         afb_hreq_reply_error(hreq, MHD_HTTP_BAD_REQUEST);
 191                         return MHD_YES;
 192                 }
 193         }
 194
 195         if (hreq->scanned != 0) {
 196                 if (hreq->replied == 0 && hreq->suspended == 0) {
 197                         MHD_suspend_connection (connection);
 198                         hreq->suspended = 1;
 199                 }
 200                 return MHD_YES;
 201         }
 202
 203         /* search an handler for the request */
 204         hreq->scanned = 1;
 205         iter = hsrv->handlers;
 206         while (iter) {
 207                 if (afb_hreq_unprefix(hreq, iter->prefix, iter->length)) {
 208                         if (iter->handler(hreq, iter->data)) {
 209                                 if (hreq->replied == 0 && hreq->suspended == 0) {
 210                                         MHD_suspend_connection (connection);
 211                                         hreq->suspended = 1;
 212                                 }
 213                                 return MHD_YES;
 214                         }
 215                         hreq->tail = hreq->url;
 216                         hreq->lentail = hreq->lenurl;
 217                 }
 218                 iter = iter->next;
 219         }
 220
 221         /* no handler */
 222         afb_hreq_reply_error(hreq, MHD_HTTP_NOT_FOUND);
 223         return MHD_YES;
 224 }
 225
 226 /* Because of POST call multiple time requestApi we need to free POST handle here */
 227 static void end_handler(void *cls, struct MHD_Connection *connection, void **recordreq,
 228                         enum MHD_RequestTerminationCode toe)
 229 {
 230         struct afb_hreq *hreq;
 231
 232         hreq = *recordreq;
 233         if (hreq->upgrade)
 234                 MHD_suspend_connection (connection);
 235         afb_hreq_unref(hreq);
 236 }
 237
 238 void run_micro_httpd(struct afb_hsrv *hsrv)
 239 {
 240         if (hsrv->in_run != 0)
 241                 hsrv->in_run = 2;
 242         else {
 243                 sd_event_source_set_io_events(hsrv->evsrc, 0);
 244                 do {
 245                         hsrv->in_run = 1;
 246                         MHD_run(hsrv->httpd);
 247                 } while(hsrv->in_run == 2);
 248                 hsrv->in_run = 0;
 249                 sd_event_source_set_io_events(hsrv->evsrc, EPOLLIN);
 250         }
 251 }
 252
 253 static int io_event_callback(sd_event_source *src, int fd, uint32_t revents, void *hsrv)
 254 {
 255         run_micro_httpd(hsrv);
 256         return 0;
 257 }
 258
 259 static int new_client_handler(void *cls, const struct sockaddr *addr, socklen_t addrlen)
 260 {
 261         return MHD_YES;
 262 }
 263
 264 static struct hsrv_handler *new_handler(
 265                 struct hsrv_handler *head,
 266                 const char *prefix,
 267                 int (*handler) (struct afb_hreq *, void *),
 268                 void *data,
 269                 int priority)
 270 {
 271         struct hsrv_handler *link, *iter, *previous;
 272         size_t length;
 273
 274         /* get the length of the prefix without its leading / */
 275         length = strlen(prefix);
 276         while (length && prefix[length - 1] == '/')
 277                 length--;
 278
 279         /* allocates the new link */
 280         link = malloc(sizeof *link);
 281         if (link == NULL)
 282                 return NULL;
 283
 284         /* initialize it */
 285         link->prefix = prefix;
 286         link->length = length;
 287         link->handler = handler;
 288         link->data = data;
 289         link->priority = priority;
 290
 291         /* adds it */
 292         previous = NULL;
 293         iter = head;
 294         while (iter && (priority < iter->priority || (priority == iter->priority && length <= iter->length))) {
 295                 previous = iter;
 296                 iter = iter->next;
 297         }
 298         link->next = iter;
 299         if (previous == NULL)
 300                 return link;
 301         previous->next = link;
 302         return head;
 303 }
 304
 305 static int handle_alias_relax(struct afb_hreq *hreq, void *data)
 306 {
 307         struct hsrv_alias *da = data;
 308
 309         if (hreq->method != afb_method_get)
 310                 return 0;
 311
 312         if (!afb_hreq_valid_tail(hreq))
 313                 return 0;
 314
 315         return afb_hreq_reply_file_if_exist(hreq, da->dirfd, &hreq->tail[1]);
 316 }
 317
 318 static int handle_alias(struct afb_hreq *hreq, void *data)
 319 {
 320         struct hsrv_alias *da = data;
 321
 322         if (hreq->method != afb_method_get) {
 323                 afb_hreq_reply_error(hreq, MHD_HTTP_METHOD_NOT_ALLOWED);
 324                 return 1;
 325         }
 326
 327         if (!afb_hreq_valid_tail(hreq)) {
 328                 afb_hreq_reply_error(hreq, MHD_HTTP_FORBIDDEN);
 329                 return 1;
 330         }
 331
 332         return afb_hreq_reply_file(hreq, da->dirfd, &hreq->tail[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                 if (afb_hsrv_add_handler(hsrv, prefix, relax ? handle_alias_relax : 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