src/afb-hsrv.c

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