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