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 enum afb_hsrv_state {
  58         hsrv_idle = 0,
  59         hsrv_run,
  60         hsrv_rerun
  61 };
  62
  63 struct afb_hsrv {
  64         unsigned refcount;
  65         enum afb_hsrv_state state;
  66         struct hsrv_handler *handlers;
  67         struct MHD_Daemon *httpd;
  68         struct upoll *upoll;
  69         char *cache_to;
  70 };
  71
  72
  73 static void reply_error(struct MHD_Connection *connection, unsigned int status)
  74 {
  75         struct MHD_Response *response = MHD_create_response_from_buffer(0, NULL, MHD_RESPMEM_PERSISTENT);
  76         MHD_queue_response(connection, status, response);
  77         MHD_destroy_response(response);
  78 }
  79
  80 static int postproc(void *cls,
  81                     enum MHD_ValueKind kind,
  82                     const char *key,
  83                     const char *filename,
  84                     const char *content_type,
  85                     const char *transfer_encoding,
  86                     const char *data,
  87                     uint64_t off,
  88                     size_t size)
  89 {
  90         struct afb_hreq *hreq = cls;
  91         if (filename != NULL)
  92                 return afb_hreq_post_add_file(hreq, key, filename, data, size);
  93         else
  94                 return afb_hreq_post_add(hreq, key, data, size);
  95 }
  96
  97 static int access_handler(
  98                 void *cls,
  99                 struct MHD_Connection *connection,
 100                 const char *url,
 101                 const char *methodstr,
 102                 const char *version,
 103                 const char *upload_data,
 104                 size_t *upload_data_size,
 105                 void **recordreq)
 106 {
 107         int rc;
 108         struct afb_hreq *hreq;
 109         enum afb_method method;
 110         struct afb_hsrv *hsrv;
 111         struct hsrv_handler *iter;
 112         const char *type;
 113
 114         hsrv = cls;
 115         hreq = *recordreq;
 116         if (hreq == NULL) {
 117                 /* create the request */
 118                 hreq = calloc(1, sizeof *hreq);
 119                 if (hreq == NULL)
 120                         goto internal_error;
 121                 *recordreq = hreq;
 122
 123                 /* get the method */
 124                 method = get_method(methodstr);
 125                 method &= afb_method_get | afb_method_post;
 126                 if (method == afb_method_none)
 127                         goto bad_request;
 128
 129                 /* init the request */
 130                 hreq->cacheTimeout = hsrv->cache_to;
 131                 hreq->connection = connection;
 132                 hreq->method = method;
 133                 hreq->version = version;
 134                 hreq->tail = hreq->url = url;
 135                 hreq->lentail = hreq->lenurl = strlen(url);
 136
 137                 /* init the post processing */
 138                 if (method == afb_method_post) {
 139                         type = afb_hreq_get_header(hreq, MHD_HTTP_HEADER_CONTENT_TYPE);
 140                         if (type == NULL) {
 141                                 /* an empty post, let's process it as a get */
 142                                 hreq->method = afb_method_get;
 143                         } else if (strcasestr(type, FORM_CONTENT) != NULL) {
 144                                 hreq->postform = MHD_create_post_processor (connection, 65500, postproc, hreq);
 145                                 if (hreq->postform == NULL)
 146                                         goto internal_error;
 147                                 return MHD_YES;
 148                         } else if (strcasestr(type, JSON_CONTENT) == NULL) {
 149                                 reply_error(connection, MHD_HTTP_UNSUPPORTED_MEDIA_TYPE);
 150                                 return MHD_YES;
 151                         }
 152                 }
 153         }
 154
 155         /* process further data */
 156         if (*upload_data_size) {
 157                 if (hreq->postform != NULL) {
 158                         if (!MHD_post_process (hreq->postform, upload_data, *upload_data_size))
 159                                 goto internal_error;
 160                 } else {
 161                         if (!afb_hreq_post_add(hreq, "", upload_data, *upload_data_size))
 162                                 goto internal_error;
 163                 }
 164                 *upload_data_size = 0;
 165                 return MHD_YES;
 166         }
 167
 168         /* flush the data */
 169         if (hreq->postform != NULL) {
 170                 rc = MHD_destroy_post_processor(hreq->postform);
 171                 hreq->postform = NULL;
 172                 if (rc == MHD_NO)
 173                         goto bad_request;
 174         }
 175
 176         /* search an handler for the request */
 177         iter = hsrv->handlers;
 178         while (iter) {
 179                 if (afb_hreq_unprefix(hreq, iter->prefix, iter->length)) {
 180                         if (iter->handler(hreq, iter->data))
 181                                 return MHD_YES;
 182                         hreq->tail = hreq->url;
 183                         hreq->lentail = hreq->lenurl;
 184                 }
 185                 iter = iter->next;
 186         }
 187
 188         /* no handler */
 189         afb_hreq_reply_error(hreq, MHD_HTTP_NOT_FOUND);
 190         return MHD_YES;
 191
 192 bad_request:
 193         reply_error(connection, MHD_HTTP_BAD_REQUEST);
 194         return MHD_YES;
 195
 196 internal_error:
 197         reply_error(connection, MHD_HTTP_INTERNAL_SERVER_ERROR);
 198         return MHD_YES;
 199 }
 200
 201 /* Because of POST call multiple time requestApi we need to free POST handle here */
 202 static void end_handler(void *cls, struct MHD_Connection *connection, void **recordreq,
 203                         enum MHD_RequestTerminationCode toe)
 204 {
 205         struct afb_hreq *hreq;
 206
 207         hreq = *recordreq;
 208         if (hreq->upgrade)
 209                 MHD_suspend_connection (connection);
 210         afb_hreq_free(hreq);
 211 }
 212
 213 static void handle_epoll_readable(struct afb_hsrv *hsrv)
 214 {
 215         if (hsrv->state != hsrv_idle)
 216                 hsrv->state = hsrv_rerun;
 217         else {
 218                 do {
 219                         hsrv->state = hsrv_run;
 220                         MHD_run(hsrv->httpd);
 221                 } while (hsrv->state == hsrv_rerun);
 222                 hsrv->state = hsrv_idle;
 223         }
 224 };
 225
 226 static int new_client_handler(void *cls, const struct sockaddr *addr, socklen_t addrlen)
 227 {
 228         return MHD_YES;
 229 }
 230
 231 static struct hsrv_handler *new_handler(
 232                 struct hsrv_handler *head,
 233                 const char *prefix,
 234                 int (*handler) (struct afb_hreq *, void *),
 235                 void *data,
 236                 int priority)
 237 {
 238         struct hsrv_handler *link, *iter, *previous;
 239         size_t length;
 240
 241         /* get the length of the prefix without its leading / */
 242         length = strlen(prefix);
 243         while (length && prefix[length - 1] == '/')
 244                 length--;
 245
 246         /* allocates the new link */
 247         link = malloc(sizeof *link);
 248         if (link == NULL)
 249                 return NULL;
 250
 251         /* initialize it */
 252         link->prefix = prefix;
 253         link->length = length;
 254         link->handler = handler;
 255         link->data = data;
 256         link->priority = priority;
 257
 258         /* adds it */
 259         previous = NULL;
 260         iter = head;
 261         while (iter && (priority < iter->priority || (priority == iter->priority && length <= iter->length))) {
 262                 previous = iter;
 263                 iter = iter->next;
 264         }
 265         link->next = iter;
 266         if (previous == NULL)
 267                 return link;
 268         previous->next = link;
 269         return head;
 270 }
 271
 272 static int handle_alias(struct afb_hreq *hreq, void *data)
 273 {
 274         struct hsrv_alias *da = data;
 275
 276         if (hreq->method != afb_method_get) {
 277                 afb_hreq_reply_error(hreq, MHD_HTTP_METHOD_NOT_ALLOWED);
 278                 return 1;
 279         }
 280
 281         if (!afb_hreq_valid_tail(hreq)) {
 282                 afb_hreq_reply_error(hreq, MHD_HTTP_FORBIDDEN);
 283                 return 1;
 284         }
 285
 286         return afb_hreq_reply_file(hreq, da->dirfd, &hreq->tail[1]);
 287 }
 288
 289 int afb_hsrv_add_handler(
 290                 struct afb_hsrv *hsrv,
 291                 const char *prefix,
 292                 int (*handler) (struct afb_hreq *, void *),
 293                 void *data,
 294                 int priority)
 295 {
 296         struct hsrv_handler *head;
 297
 298         head = new_handler(hsrv->handlers, prefix, handler, data, priority);
 299         if (head == NULL)
 300                 return 0;
 301         hsrv->handlers = head;
 302         return 1;
 303 }
 304
 305 int afb_hsrv_add_alias(struct afb_hsrv *hsrv, const char *prefix, const char *alias, int priority)
 306 {
 307         struct hsrv_alias *da;
 308         int dirfd;
 309
 310         dirfd = open(alias, O_PATH|O_DIRECTORY);
 311         if (dirfd < 0) {
 312                 /* TODO message */
 313                 return 0;
 314         }
 315         da = malloc(sizeof *da);
 316         if (da != NULL) {
 317                 da->alias = prefix;
 318                 da->directory = alias;
 319                 da->lendir = strlen(da->directory);
 320                 da->dirfd = dirfd;
 321                 if (afb_hsrv_add_handler(hsrv, prefix, handle_alias, da, priority))
 322                         return 1;
 323                 free(da);
 324         }
 325         close(dirfd);
 326         return 0;
 327 }
 328
 329 int afb_hsrv_set_cache_timeout(struct afb_hsrv *hsrv, int duration)
 330 {
 331         int rc;
 332         char *dur;
 333
 334         rc = asprintf(&dur, "%d", duration);
 335         if (rc < 0)
 336                 return 0;
 337
 338         free(hsrv->cache_to);
 339         hsrv->cache_to = dur;
 340         return 1;
 341 }
 342
 343 int afb_hsrv_start(struct afb_hsrv *hsrv, uint16_t port, unsigned int connection_timeout)
 344 {
 345         struct upoll *upoll;
 346         struct MHD_Daemon *httpd;
 347         const union MHD_DaemonInfo *info;
 348
 349         httpd = MHD_start_daemon(
 350                 MHD_USE_EPOLL_LINUX_ONLY | MHD_USE_TCP_FASTOPEN | MHD_USE_DEBUG | MHD_USE_SUSPEND_RESUME,
 351                 port,                           /* port */
 352                 new_client_handler, NULL,       /* Tcp Accept call back + extra attribute */
 353                 access_handler, hsrv,   /* Http Request Call back + extra attribute */
 354                 MHD_OPTION_NOTIFY_COMPLETED, end_handler, hsrv,
 355                 MHD_OPTION_CONNECTION_TIMEOUT, connection_timeout,
 356                 MHD_OPTION_END);        /* options-end */
 357
 358         if (httpd == NULL) {
 359                 fprintf(stderr, "Error: httpStart invalid httpd port: %d", (int)port);
 360                 return 0;
 361         }
 362
 363         info = MHD_get_daemon_info(httpd, MHD_DAEMON_INFO_EPOLL_FD_LINUX_ONLY);
 364         if (info == NULL) {
 365                 MHD_stop_daemon(httpd);
 366                 fprintf(stderr, "Error: httpStart no pollfd");
 367                 return 0;
 368         }
 369
 370         upoll = upoll_open(info->listen_fd, hsrv);
 371         if (upoll == NULL) {
 372                 MHD_stop_daemon(httpd);
 373                 fprintf(stderr, "Error: connection to upoll of httpd failed");
 374                 return 0;
 375         }
 376         upoll_on_readable(upoll, (void*)handle_epoll_readable);
 377
 378         hsrv->httpd = httpd;
 379         hsrv->upoll = upoll;
 380         return 1;
 381 }
 382
 383 void afb_hsrv_stop(struct afb_hsrv *hsrv)
 384 {
 385         if (hsrv->upoll)
 386                 upoll_close(hsrv->upoll);
 387         hsrv->upoll = NULL;
 388         if (hsrv->httpd != NULL)
 389                 MHD_stop_daemon(hsrv->httpd);
 390         hsrv->httpd = NULL;
 391 }
 392
 393 struct afb_hsrv *afb_hsrv_create()
 394 {
 395         struct afb_hsrv *result = calloc(1, sizeof(struct afb_hsrv));
 396         if (result != NULL)
 397                 result->refcount = 1;
 398         return result;
 399 }
 400
 401 void afb_hsrv_put(struct afb_hsrv *hsrv)
 402 {
 403         assert(hsrv->refcount != 0);
 404         if (!--hsrv->refcount) {
 405                 afb_hsrv_stop(hsrv);
 406                 free(hsrv);
 407         }
 408 }
 409