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 <stdio.h>
  21 #include <string.h>
  22 #include <assert.h>
  23 #include <poll.h>
  24 #include <fcntl.h>
  25 #include <sys/stat.h>
  26
  27 #include <microhttpd.h>
  28
  29 #include "afb-method.h"
  30 #include "afb-hreq.h"
  31 #include "afb-hsrv.h"
  32 #include "afb-req-itf.h"
  33 #include "verbose.h"
  34 #include "utils-upoll.h"
  35
  36
  37 #define JSON_CONTENT  "application/json"
  38 #define FORM_CONTENT  MHD_HTTP_POST_ENCODING_MULTIPART_FORMDATA
  39
  40
  41 struct hsrv_handler {
  42         struct hsrv_handler *next;
  43         const char *prefix;
  44         size_t length;
  45         int (*handler) (struct afb_hreq *, void *);
  46         void *data;
  47         int priority;
  48 };
  49
  50 struct hsrv_alias {
  51         const char *alias;
  52         const char *directory;
  53         size_t lendir;
  54         int dirfd;
  55 };
  56
  57 struct afb_hsrv {
  58         unsigned refcount;
  59         struct hsrv_handler *handlers;
  60         struct MHD_Daemon *httpd;
  61         struct upoll *upoll;
  62         char *cache_to;
  63 };
  64
  65
  66 static void reply_error(struct MHD_Connection *connection, unsigned int status)
  67 {
  68         struct MHD_Response *response = MHD_create_response_from_buffer(0, NULL, MHD_RESPMEM_PERSISTENT);
  69         MHD_queue_response(connection, status, response);
  70         MHD_destroy_response(response);
  71 }
  72
  73 static int postproc(void *cls,
  74                     enum MHD_ValueKind kind,
  75                     const char *key,
  76                     const char *filename,
  77                     const char *content_type,
  78                     const char *transfer_encoding,
  79                     const char *data,
  80                     uint64_t off,
  81                     size_t size)
  82 {
  83         struct afb_hreq *hreq = cls;
  84         if (filename != NULL)
  85                 return afb_hreq_post_add_file(hreq, key, filename, data, size);
  86         else
  87                 return afb_hreq_post_add(hreq, key, data, size);
  88 }
  89
  90 static int access_handler(
  91                 void *cls,
  92                 struct MHD_Connection *connection,
  93                 const char *url,
  94                 const char *methodstr,
  95                 const char *version,
  96                 const char *upload_data,
  97                 size_t *upload_data_size,
  98                 void **recordreq)
  99 {
 100         int rc;
 101         struct afb_hreq *hreq;
 102         enum afb_method method;
 103         struct afb_hsrv *hsrv;
 104         struct hsrv_handler *iter;
 105         const char *type;
 106
 107         hsrv = cls;
 108         hreq = *recordreq;
 109         if (hreq == NULL) {
 110                 /* create the request */
 111                 hreq = calloc(1, sizeof *hreq);
 112                 if (hreq == NULL)
 113                         goto internal_error;
 114                 *recordreq = hreq;
 115
 116                 /* get the method */
 117                 method = get_method(methodstr);
 118                 method &= afb_method_get | afb_method_post;
 119                 if (method == afb_method_none)
 120                         goto bad_request;
 121
 122                 /* init the request */
 123                 hreq->cacheTimeout = hsrv->cache_to;
 124                 hreq->connection = connection;
 125                 hreq->method = method;
 126                 hreq->version = version;
 127                 hreq->tail = hreq->url = url;
 128                 hreq->lentail = hreq->lenurl = strlen(url);
 129
 130                 /* init the post processing */
 131                 if (method == afb_method_post) {
 132                         type = afb_hreq_get_header(hreq, MHD_HTTP_HEADER_CONTENT_TYPE);
 133                         if (type == NULL) {
 134                                 /* an empty post, let's process it as a get */
 135                                 hreq->method = afb_method_get;
 136                         } else if (strcasestr(type, FORM_CONTENT) != NULL) {
 137                                 hreq->postform = MHD_create_post_processor (connection, 65500, postproc, hreq);
 138                                 if (hreq->postform == NULL)
 139                                         goto internal_error;
 140                                 return MHD_YES;
 141                         } else if (strcasestr(type, JSON_CONTENT) == NULL) {
 142                                 reply_error(connection, MHD_HTTP_UNSUPPORTED_MEDIA_TYPE);
 143                                 return MHD_YES;
 144                         }
 145                 }
 146         }
 147
 148         /* process further data */
 149         if (*upload_data_size) {
 150                 if (hreq->postform != NULL) {
 151                         if (!MHD_post_process (hreq->postform, upload_data, *upload_data_size))
 152                                 goto internal_error;
 153                 } else {
 154                         if (!afb_hreq_post_add(hreq, "", upload_data, *upload_data_size))
 155                                 goto internal_error;
 156                 }
 157                 *upload_data_size = 0;
 158                 return MHD_YES;
 159         }
 160
 161         /* flush the data */
 162         if (hreq->postform != NULL) {
 163                 rc = MHD_destroy_post_processor(hreq->postform);
 164                 hreq->postform = NULL;
 165                 if (rc == MHD_NO)
 166                         goto bad_request;
 167         }
 168
 169         /* search an handler for the request */
 170         iter = hsrv->handlers;
 171         while (iter) {
 172                 if (afb_hreq_unprefix(hreq, iter->prefix, iter->length)) {
 173                         if (iter->handler(hreq, iter->data))
 174                                 return MHD_YES;
 175                         hreq->tail = hreq->url;
 176                         hreq->lentail = hreq->lenurl;
 177                 }
 178                 iter = iter->next;
 179         }
 180
 181         /* no handler */
 182         afb_hreq_reply_error(hreq, MHD_HTTP_NOT_FOUND);
 183         return MHD_YES;
 184
 185 bad_request:
 186         reply_error(connection, MHD_HTTP_BAD_REQUEST);
 187         return MHD_YES;
 188
 189 internal_error:
 190         reply_error(connection, MHD_HTTP_INTERNAL_SERVER_ERROR);
 191         return MHD_YES;
 192 }
 193
 194 /* Because of POST call multiple time requestApi we need to free POST handle here */
 195 static void end_handler(void *cls, struct MHD_Connection *connection, void **recordreq,
 196                         enum MHD_RequestTerminationCode toe)
 197 {
 198         struct afb_hreq *hreq;
 199
 200         hreq = *recordreq;
 201         if (hreq->upgrade)
 202                 MHD_suspend_connection (connection);
 203         afb_hreq_free(hreq);
 204 }
 205
 206 static void handle_epoll_readable(struct afb_hsrv *hsrv)
 207 {
 208         upoll_on_readable(hsrv->upoll, NULL);
 209         MHD_run(hsrv->httpd);
 210         upoll_on_readable(hsrv->upoll, (void*)handle_epoll_readable);
 211 };
 212
 213 static int new_client_handler(void *cls, const struct sockaddr *addr, socklen_t addrlen)
 214 {
 215         return MHD_YES;
 216 }
 217
 218 static struct hsrv_handler *new_handler(
 219                 struct hsrv_handler *head,
 220                 const char *prefix,
 221                 int (*handler) (struct afb_hreq *, void *),
 222                 void *data,
 223                 int priority)
 224 {
 225         struct hsrv_handler *link, *iter, *previous;
 226         size_t length;
 227
 228         /* get the length of the prefix without its leading / */
 229         length = strlen(prefix);
 230         while (length && prefix[length - 1] == '/')
 231                 length--;
 232
 233         /* allocates the new link */
 234         link = malloc(sizeof *link);
 235         if (link == NULL)
 236                 return NULL;
 237
 238         /* initialize it */
 239         link->prefix = prefix;
 240         link->length = length;
 241         link->handler = handler;
 242         link->data = data;
 243         link->priority = priority;
 244
 245         /* adds it */
 246         previous = NULL;
 247         iter = head;
 248         while (iter && (priority < iter->priority || (priority == iter->priority && length <= iter->length))) {
 249                 previous = iter;
 250                 iter = iter->next;
 251         }
 252         link->next = iter;
 253         if (previous == NULL)
 254                 return link;
 255         previous->next = link;
 256         return head;
 257 }
 258
 259 static int handle_alias(struct afb_hreq *hreq, void *data)
 260 {
 261         struct hsrv_alias *da = data;
 262
 263         if (hreq->method != afb_method_get) {
 264                 afb_hreq_reply_error(hreq, MHD_HTTP_METHOD_NOT_ALLOWED);
 265                 return 1;
 266         }
 267
 268         if (!afb_hreq_valid_tail(hreq)) {
 269                 afb_hreq_reply_error(hreq, MHD_HTTP_FORBIDDEN);
 270                 return 1;
 271         }
 272
 273         return afb_hreq_reply_file(hreq, da->dirfd, &hreq->tail[1]);
 274 }
 275
 276 int afb_hsrv_add_handler(
 277                 struct afb_hsrv *hsrv,
 278                 const char *prefix,
 279                 int (*handler) (struct afb_hreq *, void *),
 280                 void *data,
 281                 int priority)
 282 {
 283         struct hsrv_handler *head;
 284
 285         head = new_handler(hsrv->handlers, prefix, handler, data, priority);
 286         if (head == NULL)
 287                 return 0;
 288         hsrv->handlers = head;
 289         return 1;
 290 }
 291
 292 int afb_hsrv_add_alias(struct afb_hsrv *hsrv, const char *prefix, const char *alias, int priority)
 293 {
 294         struct hsrv_alias *da;
 295         int dirfd;
 296
 297         dirfd = open(alias, O_PATH|O_DIRECTORY);
 298         if (dirfd < 0) {
 299                 /* TODO message */
 300                 return 0;
 301         }
 302         da = malloc(sizeof *da);
 303         if (da != NULL) {
 304                 da->alias = prefix;
 305                 da->directory = alias;
 306                 da->lendir = strlen(da->directory);
 307                 da->dirfd = dirfd;
 308                 if (afb_hsrv_add_handler(hsrv, prefix, handle_alias, da, priority))
 309                         return 1;
 310                 free(da);
 311         }
 312         close(dirfd);
 313         return 0;
 314 }
 315
 316 int afb_hsrv_set_cache_timeout(struct afb_hsrv *hsrv, int duration)
 317 {
 318         int rc;
 319         char *dur;
 320
 321         rc = asprintf(&dur, "%d", duration);
 322         if (rc < 0)
 323                 return 0;
 324
 325         free(hsrv->cache_to);
 326         hsrv->cache_to = dur;
 327         return 1;
 328 }
 329
 330 int afb_hsrv_start(struct afb_hsrv *hsrv, uint16_t port, unsigned int connection_timeout)
 331 {
 332         struct upoll *upoll;
 333         struct MHD_Daemon *httpd;
 334         const union MHD_DaemonInfo *info;
 335
 336         httpd = MHD_start_daemon(
 337                 MHD_USE_EPOLL_LINUX_ONLY | MHD_USE_TCP_FASTOPEN | MHD_USE_DEBUG | MHD_USE_SUSPEND_RESUME,
 338                 port,                           /* port */
 339                 new_client_handler, NULL,       /* Tcp Accept call back + extra attribute */
 340                 access_handler, hsrv,   /* Http Request Call back + extra attribute */
 341                 MHD_OPTION_NOTIFY_COMPLETED, end_handler, hsrv,
 342                 MHD_OPTION_CONNECTION_TIMEOUT, connection_timeout,
 343                 MHD_OPTION_END);        /* options-end */
 344
 345         if (httpd == NULL) {
 346                 fprintf(stderr, "Error: httpStart invalid httpd port: %d", (int)port);
 347                 return 0;
 348         }
 349
 350         info = MHD_get_daemon_info(httpd, MHD_DAEMON_INFO_EPOLL_FD_LINUX_ONLY);
 351         if (info == NULL) {
 352                 MHD_stop_daemon(httpd);
 353                 fprintf(stderr, "Error: httpStart no pollfd");
 354                 return 0;
 355         }
 356
 357         upoll = upoll_open(info->listen_fd, hsrv);
 358         if (upoll == NULL) {
 359                 MHD_stop_daemon(httpd);
 360                 fprintf(stderr, "Error: connection to upoll of httpd failed");
 361                 return 0;
 362         }
 363         upoll_on_readable(upoll, (void*)handle_epoll_readable);
 364
 365         hsrv->httpd = httpd;
 366         hsrv->upoll = upoll;
 367         return 1;
 368 }
 369
 370 void afb_hsrv_stop(struct afb_hsrv *hsrv)
 371 {
 372         if (hsrv->upoll)
 373                 upoll_close(hsrv->upoll);
 374         hsrv->upoll = NULL;
 375         if (hsrv->httpd != NULL)
 376                 MHD_stop_daemon(hsrv->httpd);
 377         hsrv->httpd = NULL;
 378 }
 379
 380 struct afb_hsrv *afb_hsrv_create()
 381 {
 382         struct afb_hsrv *result = calloc(1, sizeof(struct afb_hsrv));
 383         if (result != NULL)
 384                 result->refcount = 1;
 385         return result;
 386 }
 387
 388 void afb_hsrv_put(struct afb_hsrv *hsrv)
 389 {
 390         assert(hsrv->refcount != 0);
 391         if (!--hsrv->refcount) {
 392                 afb_hsrv_stop(hsrv);
 393                 free(hsrv);
 394         }
 395 }
 396