1/**
2 * @file
3 * LWIP HTTP server implementation
4 */
5
6/*
7 * Copyright (c) 2001-2003 Swedish Institute of Computer Science.
8 * All rights reserved.
9 *
10 * Redistribution and use in source and binary forms, with or without modification,
11 * are permitted provided that the following conditions are met:
12 *
13 * 1. Redistributions of source code must retain the above copyright notice,
14 *    this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright notice,
16 *    this list of conditions and the following disclaimer in the documentation
17 *    and/or other materials provided with the distribution.
18 * 3. The name of the author may not be used to endorse or promote products
19 *    derived from this software without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
22 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
23 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
24 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
25 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
26 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
29 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
30 * OF SUCH DAMAGE.
31 *
32 * This file is part of the lwIP TCP/IP stack.
33 *
34 * Author: Adam Dunkels <adam@sics.se>
35 *         Simon Goldschmidt
36 *
37 */
38
39/**
40 * @defgroup httpd HTTP server
41 * @ingroup apps
42 *
43 * This httpd supports for a
44 * rudimentary server-side-include facility which will replace tags of the form
45 * <!--#tag--> in any file whose extension is .shtml, .shtm or .ssi with
46 * strings provided by an include handler whose pointer is provided to the
47 * module via function http_set_ssi_handler().
48 * Additionally, a simple common
49 * gateway interface (CGI) handling mechanism has been added to allow clients
50 * to hook functions to particular request URIs.
51 *
52 * To enable SSI support, define label LWIP_HTTPD_SSI in lwipopts.h.
53 * To enable CGI support, define label LWIP_HTTPD_CGI in lwipopts.h.
54 *
55 * By default, the server assumes that HTTP headers are already present in
56 * each file stored in the file system.  By defining LWIP_HTTPD_DYNAMIC_HEADERS in
57 * lwipopts.h, this behavior can be changed such that the server inserts the
58 * headers automatically based on the extension of the file being served.  If
59 * this mode is used, be careful to ensure that the file system image used
60 * does not already contain the header information.
61 *
62 * File system images without headers can be created using the makefsfile
63 * tool with the -h command line option.
64 *
65 *
66 * Notes about valid SSI tags
67 * --------------------------
68 *
69 * The following assumptions are made about tags used in SSI markers:
70 *
71 * 1. No tag may contain '-' or whitespace characters within the tag name.
72 * 2. Whitespace is allowed between the tag leadin "<!--#" and the start of
73 *    the tag name and between the tag name and the leadout string "-->".
74 * 3. The maximum tag name length is LWIP_HTTPD_MAX_TAG_NAME_LEN, currently 8 characters.
75 *
76 * Notes on CGI usage
77 * ------------------
78 *
79 * The simple CGI support offered here works with GET method requests only
80 * and can handle up to 16 parameters encoded into the URI. The handler
81 * function may not write directly to the HTTP output but must return a
82 * filename that the HTTP server will send to the browser as a response to
83 * the incoming CGI request.
84 *
85 *
86 *
87 * The list of supported file types is quite short, so if makefsdata complains
88 * about an unknown extension, make sure to add it (and its doctype) to
89 * the 'g_psHTTPHeaders' list.
90 */
91#include "lwip/init.h"
92#include "lwip/apps/httpd.h"
93#include "lwip/debug.h"
94#include "lwip/stats.h"
95#include "lwip/apps/fs.h"
96#include "httpd_structs.h"
97#include "lwip/def.h"
98
99#include "lwip/altcp.h"
100#include "lwip/altcp_tcp.h"
101#if HTTPD_ENABLE_HTTPS
102#include "lwip/altcp_tls.h"
103#endif
104#ifdef LWIP_HOOK_FILENAME
105#include LWIP_HOOK_FILENAME
106#endif
107#if LWIP_HTTPD_TIMING
108#include "lwip/sys.h"
109#endif /* LWIP_HTTPD_TIMING */
110
111#include <string.h> /* memset */
112#include <stdlib.h> /* atoi */
113#include <stdio.h>
114
115#if LWIP_TCP && LWIP_CALLBACK_API
116
117/** Minimum length for a valid HTTP/0.9 request: "GET /\r\n" -> 7 bytes */
118#define MIN_REQ_LEN   7
119
120#define CRLF "\r\n"
121#if LWIP_HTTPD_SUPPORT_11_KEEPALIVE
122#define HTTP11_CONNECTIONKEEPALIVE  "Connection: keep-alive"
123#define HTTP11_CONNECTIONKEEPALIVE2 "Connection: Keep-Alive"
124#endif
125
126#if LWIP_HTTPD_DYNAMIC_FILE_READ
127#define HTTP_IS_DYNAMIC_FILE(hs) ((hs)->buf != NULL)
128#else
129#define HTTP_IS_DYNAMIC_FILE(hs) 0
130#endif
131
132/* This defines checks whether tcp_write has to copy data or not */
133
134#ifndef HTTP_IS_DATA_VOLATILE
135/** tcp_write does not have to copy data when sent from rom-file-system directly */
136#define HTTP_IS_DATA_VOLATILE(hs)       (HTTP_IS_DYNAMIC_FILE(hs) ? TCP_WRITE_FLAG_COPY : 0)
137#endif
138/** Default: dynamic headers are sent from ROM (non-dynamic headers are handled like file data) */
139#ifndef HTTP_IS_HDR_VOLATILE
140#define HTTP_IS_HDR_VOLATILE(hs, ptr)   0
141#endif
142
143/* Return values for http_send_*() */
144#define HTTP_DATA_TO_SEND_FREED    3
145#define HTTP_DATA_TO_SEND_BREAK    2
146#define HTTP_DATA_TO_SEND_CONTINUE 1
147#define HTTP_NO_DATA_TO_SEND       0
148
149typedef struct {
150  const char *name;
151  u8_t shtml;
152} default_filename;
153
154static const default_filename httpd_default_filenames[] = {
155  {"/index.shtml", 1 },
156  {"/index.ssi",   1 },
157  {"/index.shtm",  1 },
158  {"/index.html",  0 },
159  {"/index.htm",   0 }
160};
161
162#define NUM_DEFAULT_FILENAMES LWIP_ARRAYSIZE(httpd_default_filenames)
163
164#if LWIP_HTTPD_SUPPORT_REQUESTLIST
165/** HTTP request is copied here from pbufs for simple parsing */
166static char httpd_req_buf[LWIP_HTTPD_MAX_REQ_LENGTH + 1];
167#endif /* LWIP_HTTPD_SUPPORT_REQUESTLIST */
168
169#if LWIP_HTTPD_SUPPORT_POST
170#if LWIP_HTTPD_POST_MAX_RESPONSE_URI_LEN > LWIP_HTTPD_MAX_REQUEST_URI_LEN
171#define LWIP_HTTPD_URI_BUF_LEN LWIP_HTTPD_POST_MAX_RESPONSE_URI_LEN
172#endif
173#endif
174#ifndef LWIP_HTTPD_URI_BUF_LEN
175#define LWIP_HTTPD_URI_BUF_LEN LWIP_HTTPD_MAX_REQUEST_URI_LEN
176#endif
177#if LWIP_HTTPD_URI_BUF_LEN
178/* Filename for response file to send when POST is finished or
179 * search for default files when a directory is requested. */
180static char http_uri_buf[LWIP_HTTPD_URI_BUF_LEN + 1];
181#endif
182
183#if LWIP_HTTPD_DYNAMIC_HEADERS
184/* The number of individual strings that comprise the headers sent before each
185 * requested file.
186 */
187#define NUM_FILE_HDR_STRINGS 5
188#define HDR_STRINGS_IDX_HTTP_STATUS           0 /* e.g. "HTTP/1.0 200 OK\r\n" */
189#define HDR_STRINGS_IDX_SERVER_NAME           1 /* e.g. "Server: "HTTPD_SERVER_AGENT"\r\n" */
190#define HDR_STRINGS_IDX_CONTENT_LEN_KEEPALIVE 2 /* e.g. "Content-Length: xy\r\n" and/or "Connection: keep-alive\r\n" */
191#define HDR_STRINGS_IDX_CONTENT_LEN_NR        3 /* the byte count, when content-length is used */
192#define HDR_STRINGS_IDX_CONTENT_TYPE          4 /* the content type (or default answer content type including default document) */
193
194/* The dynamically generated Content-Length buffer needs space for CRLF + NULL */
195#define LWIP_HTTPD_MAX_CONTENT_LEN_OFFSET 3
196#ifndef LWIP_HTTPD_MAX_CONTENT_LEN_SIZE
197/* The dynamically generated Content-Length buffer shall be able to work with
198   ~953 MB (9 digits) */
199#define LWIP_HTTPD_MAX_CONTENT_LEN_SIZE   (9 + LWIP_HTTPD_MAX_CONTENT_LEN_OFFSET)
200#endif
201#endif /* LWIP_HTTPD_DYNAMIC_HEADERS */
202
203#if LWIP_HTTPD_SSI
204
205#define HTTPD_LAST_TAG_PART 0xFFFF
206
207enum tag_check_state {
208  TAG_NONE,       /* Not processing an SSI tag */
209  TAG_LEADIN,     /* Tag lead in "<!--#" being processed */
210  TAG_FOUND,      /* Tag name being read, looking for lead-out start */
211  TAG_LEADOUT,    /* Tag lead out "-->" being processed */
212  TAG_SENDING     /* Sending tag replacement string */
213};
214
215struct http_ssi_state {
216  const char *parsed;     /* Pointer to the first unparsed byte in buf. */
217#if !LWIP_HTTPD_SSI_INCLUDE_TAG
218  const char *tag_started;/* Pointer to the first opening '<' of the tag. */
219#endif /* !LWIP_HTTPD_SSI_INCLUDE_TAG */
220  const char *tag_end;    /* Pointer to char after the closing '>' of the tag. */
221  u32_t parse_left; /* Number of unparsed bytes in buf. */
222  u16_t tag_index;   /* Counter used by tag parsing state machine */
223  u16_t tag_insert_len; /* Length of insert in string tag_insert */
224#if LWIP_HTTPD_SSI_MULTIPART
225  u16_t tag_part; /* Counter passed to and changed by tag insertion function to insert multiple times */
226#endif /* LWIP_HTTPD_SSI_MULTIPART */
227  u8_t tag_type; /* index into http_ssi_tag_desc array */
228  u8_t tag_name_len; /* Length of the tag name in string tag_name */
229  char tag_name[LWIP_HTTPD_MAX_TAG_NAME_LEN + 1]; /* Last tag name extracted */
230  char tag_insert[LWIP_HTTPD_MAX_TAG_INSERT_LEN + 1]; /* Insert string for tag_name */
231  enum tag_check_state tag_state; /* State of the tag processor */
232};
233
234struct http_ssi_tag_description {
235  const char *lead_in;
236  const char *lead_out;
237};
238
239#endif /* LWIP_HTTPD_SSI */
240
241struct http_state {
242#if LWIP_HTTPD_KILL_OLD_ON_CONNECTIONS_EXCEEDED
243  struct http_state *next;
244#endif /* LWIP_HTTPD_KILL_OLD_ON_CONNECTIONS_EXCEEDED */
245  struct fs_file file_handle;
246  struct fs_file *handle;
247  const char *file;       /* Pointer to first unsent byte in buf. */
248
249  struct altcp_pcb *pcb;
250#if LWIP_HTTPD_SUPPORT_REQUESTLIST
251  struct pbuf *req;
252#endif /* LWIP_HTTPD_SUPPORT_REQUESTLIST */
253
254#if LWIP_HTTPD_DYNAMIC_FILE_READ
255  char *buf;        /* File read buffer. */
256  int buf_len;      /* Size of file read buffer, buf. */
257#endif /* LWIP_HTTPD_DYNAMIC_FILE_READ */
258  u32_t left;       /* Number of unsent bytes in buf. */
259  u8_t retries;
260#if LWIP_HTTPD_SUPPORT_11_KEEPALIVE
261  u8_t keepalive;
262#endif /* LWIP_HTTPD_SUPPORT_11_KEEPALIVE */
263#if LWIP_HTTPD_SSI
264  struct http_ssi_state *ssi;
265#endif /* LWIP_HTTPD_SSI */
266#if LWIP_HTTPD_CGI
267  char *params[LWIP_HTTPD_MAX_CGI_PARAMETERS]; /* Params extracted from the request URI */
268  char *param_vals[LWIP_HTTPD_MAX_CGI_PARAMETERS]; /* Values for each extracted param */
269#endif /* LWIP_HTTPD_CGI */
270#if LWIP_HTTPD_DYNAMIC_HEADERS
271  const char *hdrs[NUM_FILE_HDR_STRINGS]; /* HTTP headers to be sent. */
272  char hdr_content_len[LWIP_HTTPD_MAX_CONTENT_LEN_SIZE];
273  u16_t hdr_pos;     /* The position of the first unsent header byte in the
274                        current string */
275  u16_t hdr_index;   /* The index of the hdr string currently being sent. */
276#endif /* LWIP_HTTPD_DYNAMIC_HEADERS */
277#if LWIP_HTTPD_TIMING
278  u32_t time_started;
279#endif /* LWIP_HTTPD_TIMING */
280#if LWIP_HTTPD_SUPPORT_POST
281  u32_t post_content_len_left;
282#if LWIP_HTTPD_POST_MANUAL_WND
283  u32_t unrecved_bytes;
284  u8_t no_auto_wnd;
285  u8_t post_finished;
286#endif /* LWIP_HTTPD_POST_MANUAL_WND */
287#endif /* LWIP_HTTPD_SUPPORT_POST*/
288};
289
290#if HTTPD_USE_MEM_POOL
291LWIP_MEMPOOL_DECLARE(HTTPD_STATE,     MEMP_NUM_PARALLEL_HTTPD_CONNS,     sizeof(struct http_state),     "HTTPD_STATE")
292#if LWIP_HTTPD_SSI
293LWIP_MEMPOOL_DECLARE(HTTPD_SSI_STATE, MEMP_NUM_PARALLEL_HTTPD_SSI_CONNS, sizeof(struct http_ssi_state), "HTTPD_SSI_STATE")
294#define HTTP_FREE_SSI_STATE(x)  LWIP_MEMPOOL_FREE(HTTPD_SSI_STATE, (x))
295#define HTTP_ALLOC_SSI_STATE()  (struct http_ssi_state *)LWIP_MEMPOOL_ALLOC(HTTPD_SSI_STATE)
296#endif /* LWIP_HTTPD_SSI */
297#define HTTP_ALLOC_HTTP_STATE() (struct http_state *)LWIP_MEMPOOL_ALLOC(HTTPD_STATE)
298#define HTTP_FREE_HTTP_STATE(x) LWIP_MEMPOOL_FREE(HTTPD_STATE, (x))
299#else /* HTTPD_USE_MEM_POOL */
300#define HTTP_ALLOC_HTTP_STATE() (struct http_state *)mem_malloc(sizeof(struct http_state))
301#define HTTP_FREE_HTTP_STATE(x) mem_free(x)
302#if LWIP_HTTPD_SSI
303#define HTTP_ALLOC_SSI_STATE()  (struct http_ssi_state *)mem_malloc(sizeof(struct http_ssi_state))
304#define HTTP_FREE_SSI_STATE(x)  mem_free(x)
305#endif /* LWIP_HTTPD_SSI */
306#endif /* HTTPD_USE_MEM_POOL */
307
308static err_t http_close_conn(struct altcp_pcb *pcb, struct http_state *hs);
309static err_t http_close_or_abort_conn(struct altcp_pcb *pcb, struct http_state *hs, u8_t abort_conn);
310static err_t http_find_file(struct http_state *hs, const char *uri, int is_09);
311static err_t http_init_file(struct http_state *hs, struct fs_file *file, int is_09, const char *uri, u8_t tag_check, char *params);
312static err_t http_poll(void *arg, struct altcp_pcb *pcb);
313static u8_t http_check_eof(struct altcp_pcb *pcb, struct http_state *hs);
314#if LWIP_HTTPD_FS_ASYNC_READ
315static void http_continue(void *connection);
316#endif /* LWIP_HTTPD_FS_ASYNC_READ */
317
318#if LWIP_HTTPD_SSI
319/* SSI insert handler function pointer. */
320static tSSIHandler httpd_ssi_handler;
321#if !LWIP_HTTPD_SSI_RAW
322static int httpd_num_tags;
323static const char **httpd_tags;
324#endif /* !LWIP_HTTPD_SSI_RAW */
325
326/* Define the available tag lead-ins and corresponding lead-outs.
327 * ATTENTION: for the algorithm below using this array, it is essential
328 * that the lead in differs in the first character! */
329const struct http_ssi_tag_description http_ssi_tag_desc[] = {
330  {"<!--#", "-->"},
331  {"/*#", "*/"}
332};
333
334#endif /* LWIP_HTTPD_SSI */
335
336#if LWIP_HTTPD_CGI
337/* CGI handler information */
338static const tCGI *httpd_cgis;
339static int httpd_num_cgis;
340static int http_cgi_paramcount;
341#define http_cgi_params     hs->params
342#define http_cgi_param_vals hs->param_vals
343#elif LWIP_HTTPD_CGI_SSI
344static char *http_cgi_params[LWIP_HTTPD_MAX_CGI_PARAMETERS]; /* Params extracted from the request URI */
345static char *http_cgi_param_vals[LWIP_HTTPD_MAX_CGI_PARAMETERS]; /* Values for each extracted param */
346#endif /* LWIP_HTTPD_CGI */
347
348#if LWIP_HTTPD_KILL_OLD_ON_CONNECTIONS_EXCEEDED
349/** global list of active HTTP connections, use to kill the oldest when
350    running out of memory */
351static struct http_state *http_connections;
352
353static void
354http_add_connection(struct http_state *hs)
355{
356  /* add the connection to the list */
357  hs->next = http_connections;
358  http_connections = hs;
359}
360
361static void
362http_remove_connection(struct http_state *hs)
363{
364  /* take the connection off the list */
365  if (http_connections) {
366    if (http_connections == hs) {
367      http_connections = hs->next;
368    } else {
369      struct http_state *last;
370      for (last = http_connections; last->next != NULL; last = last->next) {
371        if (last->next == hs) {
372          last->next = hs->next;
373          break;
374        }
375      }
376    }
377  }
378}
379
380static void
381http_kill_oldest_connection(u8_t ssi_required)
382{
383  struct http_state *hs = http_connections;
384  struct http_state *hs_free_next = NULL;
385  while (hs && hs->next) {
386#if LWIP_HTTPD_SSI
387    if (ssi_required) {
388      if (hs->next->ssi != NULL) {
389        hs_free_next = hs;
390      }
391    } else
392#else /* LWIP_HTTPD_SSI */
393    LWIP_UNUSED_ARG(ssi_required);
394#endif /* LWIP_HTTPD_SSI */
395    {
396      hs_free_next = hs;
397    }
398    LWIP_ASSERT("broken list", hs != hs->next);
399    hs = hs->next;
400  }
401  if (hs_free_next != NULL) {
402    LWIP_ASSERT("hs_free_next->next != NULL", hs_free_next->next != NULL);
403    LWIP_ASSERT("hs_free_next->next->pcb != NULL", hs_free_next->next->pcb != NULL);
404    /* send RST when killing a connection because of memory shortage */
405    http_close_or_abort_conn(hs_free_next->next->pcb, hs_free_next->next, 1); /* this also unlinks the http_state from the list */
406  }
407}
408#else /* LWIP_HTTPD_KILL_OLD_ON_CONNECTIONS_EXCEEDED */
409
410#define http_add_connection(hs)
411#define http_remove_connection(hs)
412
413#endif /* LWIP_HTTPD_KILL_OLD_ON_CONNECTIONS_EXCEEDED */
414
415#if LWIP_HTTPD_SSI
416/** Allocate as struct http_ssi_state. */
417static struct http_ssi_state *
418http_ssi_state_alloc(void)
419{
420  struct http_ssi_state *ret = HTTP_ALLOC_SSI_STATE();
421#if LWIP_HTTPD_KILL_OLD_ON_CONNECTIONS_EXCEEDED
422  if (ret == NULL) {
423    http_kill_oldest_connection(1);
424    ret = HTTP_ALLOC_SSI_STATE();
425  }
426#endif /* LWIP_HTTPD_KILL_OLD_ON_CONNECTIONS_EXCEEDED */
427  if (ret != NULL) {
428    memset(ret, 0, sizeof(struct http_ssi_state));
429  }
430  return ret;
431}
432
433/** Free a struct http_ssi_state. */
434static void
435http_ssi_state_free(struct http_ssi_state *ssi)
436{
437  if (ssi != NULL) {
438    HTTP_FREE_SSI_STATE(ssi);
439  }
440}
441#endif /* LWIP_HTTPD_SSI */
442
443/** Initialize a struct http_state.
444 */
445static void
446http_state_init(struct http_state *hs)
447{
448  /* Initialize the structure. */
449  memset(hs, 0, sizeof(struct http_state));
450#if LWIP_HTTPD_DYNAMIC_HEADERS
451  /* Indicate that the headers are not yet valid */
452  hs->hdr_index = NUM_FILE_HDR_STRINGS;
453#endif /* LWIP_HTTPD_DYNAMIC_HEADERS */
454}
455
456/** Allocate a struct http_state. */
457static struct http_state *
458http_state_alloc(void)
459{
460  struct http_state *ret = HTTP_ALLOC_HTTP_STATE();
461#if LWIP_HTTPD_KILL_OLD_ON_CONNECTIONS_EXCEEDED
462  if (ret == NULL) {
463    http_kill_oldest_connection(0);
464    ret = HTTP_ALLOC_HTTP_STATE();
465  }
466#endif /* LWIP_HTTPD_KILL_OLD_ON_CONNECTIONS_EXCEEDED */
467  if (ret != NULL) {
468    http_state_init(ret);
469    http_add_connection(ret);
470  }
471  return ret;
472}
473
474/** Free a struct http_state.
475 * Also frees the file data if dynamic.
476 */
477static void
478http_state_eof(struct http_state *hs)
479{
480  if (hs->handle) {
481#if LWIP_HTTPD_TIMING
482    u32_t ms_needed = sys_now() - hs->time_started;
483    u32_t needed = LWIP_MAX(1, (ms_needed / 100));
484    LWIP_DEBUGF(HTTPD_DEBUG_TIMING, ("httpd: needed %"U32_F" ms to send file of %d bytes -> %"U32_F" bytes/sec\n",
485                                     ms_needed, hs->handle->len, ((((u32_t)hs->handle->len) * 10) / needed)));
486#endif /* LWIP_HTTPD_TIMING */
487    fs_close(hs->handle);
488    hs->handle = NULL;
489  }
490#if LWIP_HTTPD_DYNAMIC_FILE_READ
491  if (hs->buf != NULL) {
492    mem_free(hs->buf);
493    hs->buf = NULL;
494  }
495#endif /* LWIP_HTTPD_DYNAMIC_FILE_READ */
496#if LWIP_HTTPD_SSI
497  if (hs->ssi) {
498    http_ssi_state_free(hs->ssi);
499    hs->ssi = NULL;
500  }
501#endif /* LWIP_HTTPD_SSI */
502#if LWIP_HTTPD_SUPPORT_REQUESTLIST
503  if (hs->req) {
504    pbuf_free(hs->req);
505    hs->req = NULL;
506  }
507#endif /* LWIP_HTTPD_SUPPORT_REQUESTLIST */
508}
509
510/** Free a struct http_state.
511 * Also frees the file data if dynamic.
512 */
513static void
514http_state_free(struct http_state *hs)
515{
516  if (hs != NULL) {
517    http_state_eof(hs);
518    http_remove_connection(hs);
519    HTTP_FREE_HTTP_STATE(hs);
520  }
521}
522
523/** Call tcp_write() in a loop trying smaller and smaller length
524 *
525 * @param pcb altcp_pcb to send
526 * @param ptr Data to send
527 * @param length Length of data to send (in/out: on return, contains the
528 *        amount of data sent)
529 * @param apiflags directly passed to tcp_write
530 * @return the return value of tcp_write
531 */
532static err_t
533http_write(struct altcp_pcb *pcb, const void *ptr, u16_t *length, u8_t apiflags)
534{
535  u16_t len, max_len;
536  err_t err;
537  LWIP_ASSERT("length != NULL", length != NULL);
538  len = *length;
539  if (len == 0) {
540    return ERR_OK;
541  }
542  /* We cannot send more data than space available in the send buffer. */
543  max_len = altcp_sndbuf(pcb);
544  if (max_len < len) {
545    len = max_len;
546  }
547#ifdef HTTPD_MAX_WRITE_LEN
548  /* Additional limitation: e.g. don't enqueue more than 2*mss at once */
549  max_len = HTTPD_MAX_WRITE_LEN(pcb);
550  if (len > max_len) {
551    len = max_len;
552  }
553#endif /* HTTPD_MAX_WRITE_LEN */
554  do {
555    LWIP_DEBUGF(HTTPD_DEBUG | LWIP_DBG_TRACE, ("Trying to send %d bytes\n", len));
556    err = altcp_write(pcb, ptr, len, apiflags);
557    if (err == ERR_MEM) {
558      if ((altcp_sndbuf(pcb) == 0) ||
559          (altcp_sndqueuelen(pcb) >= TCP_SND_QUEUELEN)) {
560        /* no need to try smaller sizes */
561        len = 1;
562      } else {
563        len /= 2;
564      }
565      LWIP_DEBUGF(HTTPD_DEBUG | LWIP_DBG_TRACE,
566                  ("Send failed, trying less (%d bytes)\n", len));
567    }
568  } while ((err == ERR_MEM) && (len > 1));
569
570  if (err == ERR_OK) {
571    LWIP_DEBUGF(HTTPD_DEBUG | LWIP_DBG_TRACE, ("Sent %d bytes\n", len));
572    *length = len;
573  } else {
574    LWIP_DEBUGF(HTTPD_DEBUG | LWIP_DBG_TRACE, ("Send failed with err %d (\"%s\")\n", err, lwip_strerr(err)));
575    *length = 0;
576  }
577
578#if LWIP_HTTPD_SUPPORT_11_KEEPALIVE
579  /* ensure nagle is normally enabled (only disabled for persistent connections
580     when all data has been enqueued but the connection stays open for the next
581     request */
582  altcp_nagle_enable(pcb);
583#endif
584
585  return err;
586}
587
588/**
589 * The connection shall be actively closed (using RST to close from fault states).
590 * Reset the sent- and recv-callbacks.
591 *
592 * @param pcb the tcp pcb to reset callbacks
593 * @param hs connection state to free
594 */
595static err_t
596http_close_or_abort_conn(struct altcp_pcb *pcb, struct http_state *hs, u8_t abort_conn)
597{
598  err_t err;
599  LWIP_DEBUGF(HTTPD_DEBUG, ("Closing connection %p\n", (void *)pcb));
600
601#if LWIP_HTTPD_SUPPORT_POST
602  if (hs != NULL) {
603    if ((hs->post_content_len_left != 0)
604#if LWIP_HTTPD_POST_MANUAL_WND
605        || ((hs->no_auto_wnd != 0) && (hs->unrecved_bytes != 0))
606#endif /* LWIP_HTTPD_POST_MANUAL_WND */
607       ) {
608      /* make sure the post code knows that the connection is closed */
609      http_uri_buf[0] = 0;
610      httpd_post_finished(hs, http_uri_buf, LWIP_HTTPD_URI_BUF_LEN);
611    }
612  }
613#endif /* LWIP_HTTPD_SUPPORT_POST*/
614
615
616  altcp_arg(pcb, NULL);
617  altcp_recv(pcb, NULL);
618  altcp_err(pcb, NULL);
619  altcp_poll(pcb, NULL, 0);
620  altcp_sent(pcb, NULL);
621  if (hs != NULL) {
622    http_state_free(hs);
623  }
624
625  if (abort_conn) {
626    altcp_abort(pcb);
627    return ERR_OK;
628  }
629  err = altcp_close(pcb);
630  if (err != ERR_OK) {
631    LWIP_DEBUGF(HTTPD_DEBUG, ("Error %d closing %p\n", err, (void *)pcb));
632    /* error closing, try again later in poll */
633    altcp_poll(pcb, http_poll, HTTPD_POLL_INTERVAL);
634  }
635  return err;
636}
637
638/**
639 * The connection shall be actively closed.
640 * Reset the sent- and recv-callbacks.
641 *
642 * @param pcb the tcp pcb to reset callbacks
643 * @param hs connection state to free
644 */
645static err_t
646http_close_conn(struct altcp_pcb *pcb, struct http_state *hs)
647{
648  return http_close_or_abort_conn(pcb, hs, 0);
649}
650
651/** End of file: either close the connection (Connection: close) or
652 * close the file (Connection: keep-alive)
653 */
654static void
655http_eof(struct altcp_pcb *pcb, struct http_state *hs)
656{
657  /* HTTP/1.1 persistent connection? (Not supported for SSI) */
658#if LWIP_HTTPD_SUPPORT_11_KEEPALIVE
659  if (hs->keepalive) {
660    http_remove_connection(hs);
661
662    http_state_eof(hs);
663    http_state_init(hs);
664    /* restore state: */
665    hs->pcb = pcb;
666    hs->keepalive = 1;
667    http_add_connection(hs);
668    /* ensure nagle doesn't interfere with sending all data as fast as possible: */
669    altcp_nagle_disable(pcb);
670  } else
671#endif /* LWIP_HTTPD_SUPPORT_11_KEEPALIVE */
672  {
673    http_close_conn(pcb, hs);
674  }
675}
676
677#if LWIP_HTTPD_CGI || LWIP_HTTPD_CGI_SSI
678/**
679 * Extract URI parameters from the parameter-part of an URI in the form
680 * "test.cgi?x=y" @todo: better explanation!
681 * Pointers to the parameters are stored in hs->param_vals.
682 *
683 * @param hs http connection state
684 * @param params pointer to the NULL-terminated parameter string from the URI
685 * @return number of parameters extracted
686 */
687static int
688extract_uri_parameters(struct http_state *hs, char *params)
689{
690  char *pair;
691  char *equals;
692  int loop;
693
694  LWIP_UNUSED_ARG(hs);
695
696  /* If we have no parameters at all, return immediately. */
697  if (!params || (params[0] == '\0')) {
698    return (0);
699  }
700
701  /* Get a pointer to our first parameter */
702  pair = params;
703
704  /* Parse up to LWIP_HTTPD_MAX_CGI_PARAMETERS from the passed string and ignore the
705   * remainder (if any) */
706  for (loop = 0; (loop < LWIP_HTTPD_MAX_CGI_PARAMETERS) && pair; loop++) {
707
708    /* Save the name of the parameter */
709    http_cgi_params[loop] = pair;
710
711    /* Remember the start of this name=value pair */
712    equals = pair;
713
714    /* Find the start of the next name=value pair and replace the delimiter
715     * with a 0 to terminate the previous pair string. */
716    pair = strchr(pair, '&');
717    if (pair) {
718      *pair = '\0';
719      pair++;
720    } else {
721      /* We didn't find a new parameter so find the end of the URI and
722       * replace the space with a '\0' */
723      pair = strchr(equals, ' ');
724      if (pair) {
725        *pair = '\0';
726      }
727
728      /* Revert to NULL so that we exit the loop as expected. */
729      pair = NULL;
730    }
731
732    /* Now find the '=' in the previous pair, replace it with '\0' and save
733     * the parameter value string. */
734    equals = strchr(equals, '=');
735    if (equals) {
736      *equals = '\0';
737      http_cgi_param_vals[loop] = equals + 1;
738    } else {
739      http_cgi_param_vals[loop] = NULL;
740    }
741  }
742
743  return loop;
744}
745#endif /* LWIP_HTTPD_CGI || LWIP_HTTPD_CGI_SSI */
746
747#if LWIP_HTTPD_SSI
748/**
749 * Insert a tag (found in an shtml in the form of "<!--#tagname-->" into the file.
750 * The tag's name is stored in ssi->tag_name (NULL-terminated), the replacement
751 * should be written to hs->tag_insert (up to a length of LWIP_HTTPD_MAX_TAG_INSERT_LEN).
752 * The amount of data written is stored to ssi->tag_insert_len.
753 *
754 * @todo: return tag_insert_len - maybe it can be removed from struct http_state?
755 *
756 * @param hs http connection state
757 */
758static void
759get_tag_insert(struct http_state *hs)
760{
761#if LWIP_HTTPD_SSI_RAW
762  const char *tag;
763#else /* LWIP_HTTPD_SSI_RAW */
764  int tag;
765#endif /* LWIP_HTTPD_SSI_RAW */
766  size_t len;
767  struct http_ssi_state *ssi;
768#if LWIP_HTTPD_SSI_MULTIPART
769  u16_t current_tag_part;
770#endif /* LWIP_HTTPD_SSI_MULTIPART */
771
772  LWIP_ASSERT("hs != NULL", hs != NULL);
773  ssi = hs->ssi;
774  LWIP_ASSERT("ssi != NULL", ssi != NULL);
775#if LWIP_HTTPD_SSI_MULTIPART
776  current_tag_part = ssi->tag_part;
777  ssi->tag_part = HTTPD_LAST_TAG_PART;
778#endif /* LWIP_HTTPD_SSI_MULTIPART */
779#if LWIP_HTTPD_SSI_RAW
780  tag = ssi->tag_name;
781#endif
782
783  if (httpd_ssi_handler
784#if !LWIP_HTTPD_SSI_RAW
785      && httpd_tags && httpd_num_tags
786#endif /* !LWIP_HTTPD_SSI_RAW */
787     ) {
788
789    /* Find this tag in the list we have been provided. */
790#if LWIP_HTTPD_SSI_RAW
791    {
792#else /* LWIP_HTTPD_SSI_RAW */
793    for (tag = 0; tag < httpd_num_tags; tag++) {
794      if (strcmp(ssi->tag_name, httpd_tags[tag]) == 0)
795#endif /* LWIP_HTTPD_SSI_RAW */
796      {
797        ssi->tag_insert_len = httpd_ssi_handler(tag, ssi->tag_insert,
798                                              LWIP_HTTPD_MAX_TAG_INSERT_LEN
799#if LWIP_HTTPD_SSI_MULTIPART
800                                              , current_tag_part, &ssi->tag_part
801#endif /* LWIP_HTTPD_SSI_MULTIPART */
802#if LWIP_HTTPD_FILE_STATE
803                                              , (hs->handle ? hs->handle->state : NULL)
804#endif /* LWIP_HTTPD_FILE_STATE */
805                                             );
806#if LWIP_HTTPD_SSI_RAW
807        if (ssi->tag_insert_len != HTTPD_SSI_TAG_UNKNOWN)
808#endif /* LWIP_HTTPD_SSI_RAW */
809        {
810          return;
811        }
812      }
813    }
814  }
815
816  /* If we drop out, we were asked to serve a page which contains tags that
817   * we don't have a handler for. Merely echo back the tags with an error
818   * marker. */
819#define UNKNOWN_TAG1_TEXT "<b>***UNKNOWN TAG "
820#define UNKNOWN_TAG1_LEN  18
821#define UNKNOWN_TAG2_TEXT "***</b>"
822#define UNKNOWN_TAG2_LEN  7
823  len = LWIP_MIN(sizeof(ssi->tag_name), LWIP_MIN(strlen(ssi->tag_name),
824                 LWIP_HTTPD_MAX_TAG_INSERT_LEN - (UNKNOWN_TAG1_LEN + UNKNOWN_TAG2_LEN)));
825  MEMCPY(ssi->tag_insert, UNKNOWN_TAG1_TEXT, UNKNOWN_TAG1_LEN);
826  MEMCPY(&ssi->tag_insert[UNKNOWN_TAG1_LEN], ssi->tag_name, len);
827  MEMCPY(&ssi->tag_insert[UNKNOWN_TAG1_LEN + len], UNKNOWN_TAG2_TEXT, UNKNOWN_TAG2_LEN);
828  ssi->tag_insert[UNKNOWN_TAG1_LEN + len + UNKNOWN_TAG2_LEN] = 0;
829
830  len = strlen(ssi->tag_insert);
831  LWIP_ASSERT("len <= 0xffff", len <= 0xffff);
832  ssi->tag_insert_len = (u16_t)len;
833}
834#endif /* LWIP_HTTPD_SSI */
835
836#if LWIP_HTTPD_DYNAMIC_HEADERS
837/**
838 * Generate the relevant HTTP headers for the given filename and write
839 * them into the supplied buffer.
840 */
841static void
842get_http_headers(struct http_state *hs, const char *uri)
843{
844  size_t content_type;
845  char *tmp;
846  char *ext;
847  char *vars;
848
849  /* In all cases, the second header we send is the server identification
850     so set it here. */
851  hs->hdrs[HDR_STRINGS_IDX_SERVER_NAME] = g_psHTTPHeaderStrings[HTTP_HDR_SERVER];
852  hs->hdrs[HDR_STRINGS_IDX_CONTENT_LEN_KEEPALIVE] = NULL;
853  hs->hdrs[HDR_STRINGS_IDX_CONTENT_LEN_NR] = NULL;
854
855  /* Is this a normal file or the special case we use to send back the
856     default "404: Page not found" response? */
857  if (uri == NULL) {
858    hs->hdrs[HDR_STRINGS_IDX_HTTP_STATUS] = g_psHTTPHeaderStrings[HTTP_HDR_NOT_FOUND];
859#if LWIP_HTTPD_SUPPORT_11_KEEPALIVE
860    if (hs->keepalive) {
861      hs->hdrs[HDR_STRINGS_IDX_CONTENT_TYPE] = g_psHTTPHeaderStrings[DEFAULT_404_HTML_PERSISTENT];
862    } else
863#endif
864    {
865      hs->hdrs[HDR_STRINGS_IDX_CONTENT_TYPE] = g_psHTTPHeaderStrings[DEFAULT_404_HTML];
866    }
867
868    /* Set up to send the first header string. */
869    hs->hdr_index = 0;
870    hs->hdr_pos = 0;
871    return;
872  }
873  /* We are dealing with a particular filename. Look for one other
874      special case.  We assume that any filename with "404" in it must be
875      indicative of a 404 server error whereas all other files require
876      the 200 OK header. */
877  if (strstr(uri, "404")) {
878    hs->hdrs[HDR_STRINGS_IDX_HTTP_STATUS] = g_psHTTPHeaderStrings[HTTP_HDR_NOT_FOUND];
879  } else if (strstr(uri, "400")) {
880    hs->hdrs[HDR_STRINGS_IDX_HTTP_STATUS] = g_psHTTPHeaderStrings[HTTP_HDR_BAD_REQUEST];
881  } else if (strstr(uri, "501")) {
882    hs->hdrs[HDR_STRINGS_IDX_HTTP_STATUS] = g_psHTTPHeaderStrings[HTTP_HDR_NOT_IMPL];
883  } else {
884    hs->hdrs[HDR_STRINGS_IDX_HTTP_STATUS] = g_psHTTPHeaderStrings[HTTP_HDR_OK];
885  }
886
887  /* Determine if the URI has any variables and, if so, temporarily remove
888      them. */
889  vars = strchr(uri, '?');
890  if (vars) {
891    *vars = '\0';
892  }
893
894  /* Get a pointer to the file extension.  We find this by looking for the
895      last occurrence of "." in the filename passed. */
896  ext = NULL;
897  tmp = strchr(uri, '.');
898  while (tmp) {
899    ext = tmp + 1;
900    tmp = strchr(ext, '.');
901  }
902  if (ext != NULL) {
903    /* Now determine the content type and add the relevant header for that. */
904    for (content_type = 0; content_type < NUM_HTTP_HEADERS; content_type++) {
905      /* Have we found a matching extension? */
906      if (!lwip_stricmp(g_psHTTPHeaders[content_type].extension, ext)) {
907        break;
908      }
909    }
910  } else {
911    content_type = NUM_HTTP_HEADERS;
912  }
913
914  /* Reinstate the parameter marker if there was one in the original URI. */
915  if (vars) {
916    *vars = '?';
917  }
918
919#if LWIP_HTTPD_OMIT_HEADER_FOR_EXTENSIONLESS_URI
920  /* Does the URL passed have any file extension?  If not, we assume it
921     is a special-case URL used for control state notification and we do
922     not send any HTTP headers with the response. */
923  if (!ext) {
924    /* Force the header index to a value indicating that all headers
925       have already been sent. */
926    hs->hdr_index = NUM_FILE_HDR_STRINGS;
927    return;
928  }
929#endif /* LWIP_HTTPD_OMIT_HEADER_FOR_EXTENSIONLESS_URI */
930  /* Did we find a matching extension? */
931  if (content_type < NUM_HTTP_HEADERS) {
932    /* yes, store it */
933    hs->hdrs[HDR_STRINGS_IDX_CONTENT_TYPE] = g_psHTTPHeaders[content_type].content_type;
934  } else if (!ext) {
935    /* no, no extension found -> use binary transfer to prevent the browser adding '.txt' on save */
936    hs->hdrs[HDR_STRINGS_IDX_CONTENT_TYPE] = HTTP_HDR_APP;
937  } else {
938    /* No - use the default, plain text file type. */
939    hs->hdrs[HDR_STRINGS_IDX_CONTENT_TYPE] = HTTP_HDR_DEFAULT_TYPE;
940  }
941  /* Set up to send the first header string. */
942  hs->hdr_index = 0;
943  hs->hdr_pos = 0;
944}
945
946/* Add content-length header? */
947static void
948get_http_content_length(struct http_state *hs)
949{
950  u8_t add_content_len = 0;
951
952  LWIP_ASSERT("already been here?", hs->hdrs[HDR_STRINGS_IDX_CONTENT_LEN_KEEPALIVE] == NULL);
953
954  add_content_len = 0;
955#if LWIP_HTTPD_SSI
956  if (hs->ssi == NULL) /* @todo: get maximum file length from SSI */
957#endif /* LWIP_HTTPD_SSI */
958  {
959    if ((hs->handle != NULL) && (hs->handle->flags & FS_FILE_FLAGS_HEADER_PERSISTENT)) {
960      add_content_len = 1;
961    }
962  }
963  if (add_content_len) {
964    size_t len;
965    lwip_itoa(hs->hdr_content_len, (size_t)LWIP_HTTPD_MAX_CONTENT_LEN_SIZE,
966              hs->handle->len);
967    len = strlen(hs->hdr_content_len);
968    if (len <= LWIP_HTTPD_MAX_CONTENT_LEN_SIZE - LWIP_HTTPD_MAX_CONTENT_LEN_OFFSET) {
969      SMEMCPY(&hs->hdr_content_len[len], CRLF, 3);
970      hs->hdrs[HDR_STRINGS_IDX_CONTENT_LEN_NR] = hs->hdr_content_len;
971    } else {
972      add_content_len = 0;
973    }
974  }
975#if LWIP_HTTPD_SUPPORT_11_KEEPALIVE
976  if (add_content_len) {
977    hs->hdrs[HDR_STRINGS_IDX_CONTENT_LEN_KEEPALIVE] = g_psHTTPHeaderStrings[HTTP_HDR_KEEPALIVE_LEN];
978  } else {
979    hs->hdrs[HDR_STRINGS_IDX_CONTENT_LEN_KEEPALIVE] = g_psHTTPHeaderStrings[HTTP_HDR_CONN_CLOSE];
980    hs->keepalive = 0;
981  }
982#else /* LWIP_HTTPD_SUPPORT_11_KEEPALIVE */
983  if (add_content_len) {
984    hs->hdrs[HDR_STRINGS_IDX_CONTENT_LEN_KEEPALIVE] = g_psHTTPHeaderStrings[HTTP_HDR_CONTENT_LENGTH];
985  }
986#endif /* LWIP_HTTPD_SUPPORT_11_KEEPALIVE */
987}
988
989/** Sub-function of http_send(): send dynamic headers
990 *
991 * @returns: - HTTP_NO_DATA_TO_SEND: no new data has been enqueued
992 *           - HTTP_DATA_TO_SEND_CONTINUE: continue with sending HTTP body
993 *           - HTTP_DATA_TO_SEND_BREAK: data has been enqueued, headers pending,
994 *                                      so don't send HTTP body yet
995 *           - HTTP_DATA_TO_SEND_FREED: http_state and pcb are already freed
996 */
997static u8_t
998http_send_headers(struct altcp_pcb *pcb, struct http_state *hs)
999{
1000  err_t err;
1001  u16_t len;
1002  u8_t data_to_send = HTTP_NO_DATA_TO_SEND;
1003  u16_t hdrlen, sendlen;
1004
1005  if (hs->hdrs[HDR_STRINGS_IDX_CONTENT_LEN_KEEPALIVE] == NULL) {
1006    /* set up "content-length" and "connection:" headers */
1007    get_http_content_length(hs);
1008  }
1009
1010  /* How much data can we send? */
1011  len = altcp_sndbuf(pcb);
1012  sendlen = len;
1013
1014  while (len && (hs->hdr_index < NUM_FILE_HDR_STRINGS) && sendlen) {
1015    const void *ptr;
1016    u16_t old_sendlen;
1017    u8_t apiflags;
1018    /* How much do we have to send from the current header? */
1019    hdrlen = (u16_t)strlen(hs->hdrs[hs->hdr_index]);
1020
1021    /* How much of this can we send? */
1022    sendlen = (len < (hdrlen - hs->hdr_pos)) ? len : (hdrlen - hs->hdr_pos);
1023
1024    /* Send this amount of data or as much as we can given memory
1025     * constraints. */
1026    ptr = (const void *)(hs->hdrs[hs->hdr_index] + hs->hdr_pos);
1027    old_sendlen = sendlen;
1028    apiflags = HTTP_IS_HDR_VOLATILE(hs, ptr);
1029    if (hs->hdr_index == HDR_STRINGS_IDX_CONTENT_LEN_NR) {
1030      /* content-length is always volatile */
1031      apiflags |= TCP_WRITE_FLAG_COPY;
1032    }
1033    if (hs->hdr_index < NUM_FILE_HDR_STRINGS - 1) {
1034      apiflags |= TCP_WRITE_FLAG_MORE;
1035    }
1036    err = http_write(pcb, ptr, &sendlen, apiflags);
1037    if ((err == ERR_OK) && (old_sendlen != sendlen)) {
1038      /* Remember that we added some more data to be transmitted. */
1039      data_to_send = HTTP_DATA_TO_SEND_CONTINUE;
1040    } else if (err != ERR_OK) {
1041      /* special case: http_write does not try to send 1 byte */
1042      sendlen = 0;
1043    }
1044
1045    /* Fix up the header position for the next time round. */
1046    hs->hdr_pos += sendlen;
1047    len -= sendlen;
1048
1049    /* Have we finished sending this string? */
1050    if (hs->hdr_pos == hdrlen) {
1051      /* Yes - move on to the next one */
1052      hs->hdr_index++;
1053      /* skip headers that are NULL (not all headers are required) */
1054      while ((hs->hdr_index < NUM_FILE_HDR_STRINGS) &&
1055             (hs->hdrs[hs->hdr_index] == NULL)) {
1056        hs->hdr_index++;
1057      }
1058      hs->hdr_pos = 0;
1059    }
1060  }
1061
1062  if ((hs->hdr_index >= NUM_FILE_HDR_STRINGS) && (hs->file == NULL)) {
1063    /* When we are at the end of the headers, check for data to send
1064     * instead of waiting for ACK from remote side to continue
1065     * (which would happen when sending files from async read). */
1066    if (http_check_eof(pcb, hs)) {
1067      data_to_send = HTTP_DATA_TO_SEND_BREAK;
1068    } else {
1069      /* At this point, for non-keepalive connections, hs is deallocated an
1070         pcb is closed. */
1071      return HTTP_DATA_TO_SEND_FREED;
1072    }
1073  }
1074  /* If we get here and there are still header bytes to send, we send
1075   * the header information we just wrote immediately. If there are no
1076   * more headers to send, but we do have file data to send, drop through
1077   * to try to send some file data too. */
1078  if ((hs->hdr_index < NUM_FILE_HDR_STRINGS) || !hs->file) {
1079    LWIP_DEBUGF(HTTPD_DEBUG, ("tcp_output\n"));
1080    return HTTP_DATA_TO_SEND_BREAK;
1081  }
1082  return data_to_send;
1083}
1084#endif /* LWIP_HTTPD_DYNAMIC_HEADERS */
1085
1086/** Sub-function of http_send(): end-of-file (or block) is reached,
1087 * either close the file or read the next block (if supported).
1088 *
1089 * @returns: 0 if the file is finished or no data has been read
1090 *           1 if the file is not finished and data has been read
1091 */
1092static u8_t
1093http_check_eof(struct altcp_pcb *pcb, struct http_state *hs)
1094{
1095  int bytes_left;
1096#if LWIP_HTTPD_DYNAMIC_FILE_READ
1097  int count;
1098#ifdef HTTPD_MAX_WRITE_LEN
1099  int max_write_len;
1100#endif /* HTTPD_MAX_WRITE_LEN */
1101#endif /* LWIP_HTTPD_DYNAMIC_FILE_READ */
1102
1103  /* Do we have a valid file handle? */
1104  if (hs->handle == NULL) {
1105    /* No - close the connection. */
1106    http_eof(pcb, hs);
1107    return 0;
1108  }
1109  bytes_left = fs_bytes_left(hs->handle);
1110  if (bytes_left <= 0) {
1111    /* We reached the end of the file so this request is done. */
1112    LWIP_DEBUGF(HTTPD_DEBUG, ("End of file.\n"));
1113    http_eof(pcb, hs);
1114    return 0;
1115  }
1116#if LWIP_HTTPD_DYNAMIC_FILE_READ
1117  /* Do we already have a send buffer allocated? */
1118  if (hs->buf) {
1119    /* Yes - get the length of the buffer */
1120    count = LWIP_MIN(hs->buf_len, bytes_left);
1121  } else {
1122    /* We don't have a send buffer so allocate one now */
1123    count = altcp_sndbuf(pcb);
1124    if (bytes_left < count) {
1125      count = bytes_left;
1126    }
1127#ifdef HTTPD_MAX_WRITE_LEN
1128    /* Additional limitation: e.g. don't enqueue more than 2*mss at once */
1129    max_write_len = HTTPD_MAX_WRITE_LEN(pcb);
1130    if (count > max_write_len) {
1131      count = max_write_len;
1132    }
1133#endif /* HTTPD_MAX_WRITE_LEN */
1134    do {
1135      hs->buf = (char *)mem_malloc((mem_size_t)count);
1136      if (hs->buf != NULL) {
1137        hs->buf_len = count;
1138        break;
1139      }
1140      count = count / 2;
1141    } while (count > 100);
1142
1143    /* Did we get a send buffer? If not, return immediately. */
1144    if (hs->buf == NULL) {
1145      LWIP_DEBUGF(HTTPD_DEBUG, ("No buff\n"));
1146      return 0;
1147    }
1148  }
1149
1150  /* Read a block of data from the file. */
1151  LWIP_DEBUGF(HTTPD_DEBUG, ("Trying to read %d bytes.\n", count));
1152
1153#if LWIP_HTTPD_FS_ASYNC_READ
1154  count = fs_read_async(hs->handle, hs->buf, count, http_continue, hs);
1155#else /* LWIP_HTTPD_FS_ASYNC_READ */
1156  count = fs_read(hs->handle, hs->buf, count);
1157#endif /* LWIP_HTTPD_FS_ASYNC_READ */
1158  if (count < 0) {
1159    if (count == FS_READ_DELAYED) {
1160      /* Delayed read, wait for FS to unblock us */
1161      return 0;
1162    }
1163    /* We reached the end of the file so this request is done.
1164     * @todo: close here for HTTP/1.1 when reading file fails */
1165    LWIP_DEBUGF(HTTPD_DEBUG, ("End of file.\n"));
1166    http_eof(pcb, hs);
1167    return 0;
1168  }
1169
1170  /* Set up to send the block of data we just read */
1171  LWIP_DEBUGF(HTTPD_DEBUG, ("Read %d bytes.\n", count));
1172  hs->left = count;
1173  hs->file = hs->buf;
1174#if LWIP_HTTPD_SSI
1175  if (hs->ssi) {
1176    hs->ssi->parse_left = count;
1177    hs->ssi->parsed = hs->buf;
1178  }
1179#endif /* LWIP_HTTPD_SSI */
1180#else /* LWIP_HTTPD_DYNAMIC_FILE_READ */
1181  LWIP_ASSERT("SSI and DYNAMIC_HEADERS turned off but eof not reached", 0);
1182#endif /* LWIP_HTTPD_SSI || LWIP_HTTPD_DYNAMIC_HEADERS */
1183  return 1;
1184}
1185
1186/** Sub-function of http_send(): This is the normal send-routine for non-ssi files
1187 *
1188 * @returns: - 1: data has been written (so call tcp_ouput)
1189 *           - 0: no data has been written (no need to call tcp_output)
1190 */
1191static u8_t
1192http_send_data_nonssi(struct altcp_pcb *pcb, struct http_state *hs)
1193{
1194  err_t err;
1195  u16_t len;
1196  u8_t data_to_send = 0;
1197
1198  /* We are not processing an SHTML file so no tag checking is necessary.
1199   * Just send the data as we received it from the file. */
1200  len = (u16_t)LWIP_MIN(hs->left, 0xffff);
1201
1202  err = http_write(pcb, hs->file, &len, HTTP_IS_DATA_VOLATILE(hs));
1203  if (err == ERR_OK) {
1204    data_to_send = 1;
1205    hs->file += len;
1206    hs->left -= len;
1207  }
1208
1209  return data_to_send;
1210}
1211
1212#if LWIP_HTTPD_SSI
1213/** Sub-function of http_send(): This is the send-routine for ssi files
1214 *
1215 * @returns: - 1: data has been written (so call tcp_ouput)
1216 *           - 0: no data has been written (no need to call tcp_output)
1217 */
1218static u8_t
1219http_send_data_ssi(struct altcp_pcb *pcb, struct http_state *hs)
1220{
1221  err_t err = ERR_OK;
1222  u16_t len;
1223  u8_t data_to_send = 0;
1224  u8_t tag_type;
1225
1226  struct http_ssi_state *ssi = hs->ssi;
1227  LWIP_ASSERT("ssi != NULL", ssi != NULL);
1228  /* We are processing an SHTML file so need to scan for tags and replace
1229   * them with insert strings. We need to be careful here since a tag may
1230   * straddle the boundary of two blocks read from the file and we may also
1231   * have to split the insert string between two tcp_write operations. */
1232
1233  /* How much data could we send? */
1234  len = altcp_sndbuf(pcb);
1235
1236  /* Do we have remaining data to send before parsing more? */
1237  if (ssi->parsed > hs->file) {
1238    len = (u16_t)LWIP_MIN(ssi->parsed - hs->file, 0xffff);
1239
1240    err = http_write(pcb, hs->file, &len, HTTP_IS_DATA_VOLATILE(hs));
1241    if (err == ERR_OK) {
1242      data_to_send = 1;
1243      hs->file += len;
1244      hs->left -= len;
1245    }
1246
1247    /* If the send buffer is full, return now. */
1248    if (altcp_sndbuf(pcb) == 0) {
1249      return data_to_send;
1250    }
1251  }
1252
1253  LWIP_DEBUGF(HTTPD_DEBUG, ("State %d, %d left\n", ssi->tag_state, (int)ssi->parse_left));
1254
1255  /* We have sent all the data that was already parsed so continue parsing
1256   * the buffer contents looking for SSI tags. */
1257  while (((ssi->tag_state == TAG_SENDING) || ssi->parse_left) && (err == ERR_OK)) {
1258    if (len == 0) {
1259      return data_to_send;
1260    }
1261    switch (ssi->tag_state) {
1262      case TAG_NONE:
1263        /* We are not currently processing an SSI tag so scan for the
1264         * start of the lead-in marker. */
1265        for (tag_type = 0; tag_type < LWIP_ARRAYSIZE(http_ssi_tag_desc); tag_type++) {
1266          if (*ssi->parsed == http_ssi_tag_desc[tag_type].lead_in[0]) {
1267            /* We found what could be the lead-in for a new tag so change
1268             * state appropriately. */
1269            ssi->tag_type = tag_type;
1270            ssi->tag_state = TAG_LEADIN;
1271            ssi->tag_index = 1;
1272  #if !LWIP_HTTPD_SSI_INCLUDE_TAG
1273            ssi->tag_started = ssi->parsed;
1274  #endif /* !LWIP_HTTPD_SSI_INCLUDE_TAG */
1275            break;
1276          }
1277        }
1278
1279        /* Move on to the next character in the buffer */
1280        ssi->parse_left--;
1281        ssi->parsed++;
1282        break;
1283
1284      case TAG_LEADIN:
1285        /* We are processing the lead-in marker, looking for the start of
1286         * the tag name. */
1287
1288        /* Have we reached the end of the leadin? */
1289        if (http_ssi_tag_desc[ssi->tag_type].lead_in[ssi->tag_index] == 0) {
1290          ssi->tag_index = 0;
1291          ssi->tag_state = TAG_FOUND;
1292        } else {
1293          /* Have we found the next character we expect for the tag leadin? */
1294          if (*ssi->parsed == http_ssi_tag_desc[ssi->tag_type].lead_in[ssi->tag_index]) {
1295            /* Yes - move to the next one unless we have found the complete
1296             * leadin, in which case we start looking for the tag itself */
1297            ssi->tag_index++;
1298          } else {
1299            /* We found an unexpected character so this is not a tag. Move
1300             * back to idle state. */
1301            ssi->tag_state = TAG_NONE;
1302          }
1303
1304          /* Move on to the next character in the buffer */
1305          ssi->parse_left--;
1306          ssi->parsed++;
1307        }
1308        break;
1309
1310      case TAG_FOUND:
1311        /* We are reading the tag name, looking for the start of the
1312         * lead-out marker and removing any whitespace found. */
1313
1314        /* Remove leading whitespace between the tag leading and the first
1315         * tag name character. */
1316        if ((ssi->tag_index == 0) && ((*ssi->parsed == ' ') ||
1317                                      (*ssi->parsed == '\t') || (*ssi->parsed == '\n') ||
1318                                      (*ssi->parsed == '\r'))) {
1319          /* Move on to the next character in the buffer */
1320          ssi->parse_left--;
1321          ssi->parsed++;
1322          break;
1323        }
1324
1325        /* Have we found the end of the tag name? This is signalled by
1326         * us finding the first leadout character or whitespace */
1327        if ((*ssi->parsed == http_ssi_tag_desc[ssi->tag_type].lead_out[0]) ||
1328            (*ssi->parsed == ' ')  || (*ssi->parsed == '\t') ||
1329            (*ssi->parsed == '\n') || (*ssi->parsed == '\r')) {
1330
1331          if (ssi->tag_index == 0) {
1332            /* We read a zero length tag so ignore it. */
1333            ssi->tag_state = TAG_NONE;
1334          } else {
1335            /* We read a non-empty tag so go ahead and look for the
1336             * leadout string. */
1337            ssi->tag_state = TAG_LEADOUT;
1338            LWIP_ASSERT("ssi->tag_index <= 0xff", ssi->tag_index <= 0xff);
1339            ssi->tag_name_len = (u8_t)ssi->tag_index;
1340            ssi->tag_name[ssi->tag_index] = '\0';
1341            if (*ssi->parsed == http_ssi_tag_desc[ssi->tag_type].lead_out[0]) {
1342              ssi->tag_index = 1;
1343            } else {
1344              ssi->tag_index = 0;
1345            }
1346          }
1347        } else {
1348          /* This character is part of the tag name so save it */
1349          if (ssi->tag_index < LWIP_HTTPD_MAX_TAG_NAME_LEN) {
1350            ssi->tag_name[ssi->tag_index++] = *ssi->parsed;
1351          } else {
1352            /* The tag was too long so ignore it. */
1353            ssi->tag_state = TAG_NONE;
1354          }
1355        }
1356
1357        /* Move on to the next character in the buffer */
1358        ssi->parse_left--;
1359        ssi->parsed++;
1360
1361        break;
1362
1363      /* We are looking for the end of the lead-out marker. */
1364      case TAG_LEADOUT:
1365        /* Remove leading whitespace between the tag leading and the first
1366         * tag leadout character. */
1367        if ((ssi->tag_index == 0) && ((*ssi->parsed == ' ') ||
1368                                      (*ssi->parsed == '\t') || (*ssi->parsed == '\n') ||
1369                                      (*ssi->parsed == '\r'))) {
1370          /* Move on to the next character in the buffer */
1371          ssi->parse_left--;
1372          ssi->parsed++;
1373          break;
1374        }
1375
1376        /* Have we found the next character we expect for the tag leadout? */
1377        if (*ssi->parsed == http_ssi_tag_desc[ssi->tag_type].lead_out[ssi->tag_index]) {
1378          /* Yes - move to the next one unless we have found the complete
1379           * leadout, in which case we need to call the client to process
1380           * the tag. */
1381
1382          /* Move on to the next character in the buffer */
1383          ssi->parse_left--;
1384          ssi->parsed++;
1385          ssi->tag_index++;
1386
1387          if (http_ssi_tag_desc[ssi->tag_type].lead_out[ssi->tag_index] == 0) {
1388            /* Call the client to ask for the insert string for the
1389             * tag we just found. */
1390#if LWIP_HTTPD_SSI_MULTIPART
1391            ssi->tag_part = 0; /* start with tag part 0 */
1392#endif /* LWIP_HTTPD_SSI_MULTIPART */
1393            get_tag_insert(hs);
1394
1395            /* Next time through, we are going to be sending data
1396             * immediately, either the end of the block we start
1397             * sending here or the insert string. */
1398            ssi->tag_index = 0;
1399            ssi->tag_state = TAG_SENDING;
1400            ssi->tag_end = ssi->parsed;
1401#if !LWIP_HTTPD_SSI_INCLUDE_TAG
1402            ssi->parsed = ssi->tag_started;
1403#endif /* !LWIP_HTTPD_SSI_INCLUDE_TAG*/
1404
1405            /* If there is any unsent data in the buffer prior to the
1406             * tag, we need to send it now. */
1407            if (ssi->tag_end > hs->file) {
1408              /* How much of the data can we send? */
1409#if LWIP_HTTPD_SSI_INCLUDE_TAG
1410              len = (u16_t)LWIP_MIN(ssi->tag_end - hs->file, 0xffff);
1411#else /* LWIP_HTTPD_SSI_INCLUDE_TAG*/
1412              /* we would include the tag in sending */
1413              len = (u16_t)LWIP_MIN(ssi->tag_started - hs->file, 0xffff);
1414#endif /* LWIP_HTTPD_SSI_INCLUDE_TAG*/
1415
1416              err = http_write(pcb, hs->file, &len, HTTP_IS_DATA_VOLATILE(hs));
1417              if (err == ERR_OK) {
1418                data_to_send = 1;
1419#if !LWIP_HTTPD_SSI_INCLUDE_TAG
1420                if (ssi->tag_started <= hs->file) {
1421                  /* pretend to have sent the tag, too */
1422                  len += (u16_t)(ssi->tag_end - ssi->tag_started);
1423                }
1424#endif /* !LWIP_HTTPD_SSI_INCLUDE_TAG*/
1425                hs->file += len;
1426                hs->left -= len;
1427              }
1428            }
1429          }
1430        } else {
1431          /* We found an unexpected character so this is not a tag. Move
1432           * back to idle state. */
1433          ssi->parse_left--;
1434          ssi->parsed++;
1435          ssi->tag_state = TAG_NONE;
1436        }
1437        break;
1438
1439      /*
1440       * We have found a valid tag and are in the process of sending
1441       * data as a result of that discovery. We send either remaining data
1442       * from the file prior to the insert point or the insert string itself.
1443       */
1444      case TAG_SENDING:
1445        /* Do we have any remaining file data to send from the buffer prior
1446         * to the tag? */
1447        if (ssi->tag_end > hs->file) {
1448          /* How much of the data can we send? */
1449#if LWIP_HTTPD_SSI_INCLUDE_TAG
1450          len = (u16_t)LWIP_MIN(ssi->tag_end - hs->file, 0xffff);
1451#else /* LWIP_HTTPD_SSI_INCLUDE_TAG*/
1452          LWIP_ASSERT("hs->started >= hs->file", ssi->tag_started >= hs->file);
1453          /* we would include the tag in sending */
1454          len = (u16_t)LWIP_MIN(ssi->tag_started - hs->file, 0xffff);
1455#endif /* LWIP_HTTPD_SSI_INCLUDE_TAG*/
1456          if (len != 0) {
1457            err = http_write(pcb, hs->file, &len, HTTP_IS_DATA_VOLATILE(hs));
1458          } else {
1459            err = ERR_OK;
1460          }
1461          if (err == ERR_OK) {
1462            data_to_send = 1;
1463#if !LWIP_HTTPD_SSI_INCLUDE_TAG
1464            if (ssi->tag_started <= hs->file) {
1465              /* pretend to have sent the tag, too */
1466              len += (u16_t)(ssi->tag_end - ssi->tag_started);
1467            }
1468#endif /* !LWIP_HTTPD_SSI_INCLUDE_TAG*/
1469            hs->file += len;
1470            hs->left -= len;
1471          }
1472        } else {
1473#if LWIP_HTTPD_SSI_MULTIPART
1474          if (ssi->tag_index >= ssi->tag_insert_len) {
1475            /* Did the last SSIHandler have more to send? */
1476            if (ssi->tag_part != HTTPD_LAST_TAG_PART) {
1477              /* If so, call it again */
1478              ssi->tag_index = 0;
1479              get_tag_insert(hs);
1480            }
1481          }
1482#endif /* LWIP_HTTPD_SSI_MULTIPART */
1483
1484          /* Do we still have insert data left to send? */
1485          if (ssi->tag_index < ssi->tag_insert_len) {
1486            /* We are sending the insert string itself. How much of the
1487             * insert can we send? */
1488            len = (ssi->tag_insert_len - ssi->tag_index);
1489
1490            /* Note that we set the copy flag here since we only have a
1491             * single tag insert buffer per connection. If we don't do
1492             * this, insert corruption can occur if more than one insert
1493             * is processed before we call tcp_output. */
1494            err = http_write(pcb, &(ssi->tag_insert[ssi->tag_index]), &len,
1495                             HTTP_IS_TAG_VOLATILE(hs));
1496            if (err == ERR_OK) {
1497              data_to_send = 1;
1498              ssi->tag_index += len;
1499              /* Don't return here: keep on sending data */
1500            }
1501          } else {
1502#if LWIP_HTTPD_SSI_MULTIPART
1503            if (ssi->tag_part == HTTPD_LAST_TAG_PART)
1504#endif /* LWIP_HTTPD_SSI_MULTIPART */
1505            {
1506              /* We have sent all the insert data so go back to looking for
1507               * a new tag. */
1508              LWIP_DEBUGF(HTTPD_DEBUG, ("Everything sent.\n"));
1509              ssi->tag_index = 0;
1510              ssi->tag_state = TAG_NONE;
1511#if !LWIP_HTTPD_SSI_INCLUDE_TAG
1512              ssi->parsed = ssi->tag_end;
1513#endif /* !LWIP_HTTPD_SSI_INCLUDE_TAG*/
1514            }
1515          }
1516          break;
1517        default:
1518          break;
1519        }
1520    }
1521  }
1522
1523  /* If we drop out of the end of the for loop, this implies we must have
1524   * file data to send so send it now. In TAG_SENDING state, we've already
1525   * handled this so skip the send if that's the case. */
1526  if ((ssi->tag_state != TAG_SENDING) && (ssi->parsed > hs->file)) {
1527#if LWIP_HTTPD_DYNAMIC_FILE_READ && !LWIP_HTTPD_SSI_INCLUDE_TAG
1528    if ((ssi->tag_state != TAG_NONE) && (ssi->tag_started > ssi->tag_end)) {
1529      /* If we found tag on the edge of the read buffer: just throw away the first part
1530         (we have copied/saved everything required for parsing on later). */
1531      len = (u16_t)(ssi->tag_started - hs->file);
1532      hs->left -= (ssi->parsed - ssi->tag_started);
1533      ssi->parsed = ssi->tag_started;
1534      ssi->tag_started = hs->buf;
1535    } else
1536#endif /* LWIP_HTTPD_DYNAMIC_FILE_READ && !LWIP_HTTPD_SSI_INCLUDE_TAG */
1537    {
1538      len = (u16_t)LWIP_MIN(ssi->parsed - hs->file, 0xffff);
1539    }
1540
1541    err = http_write(pcb, hs->file, &len, HTTP_IS_DATA_VOLATILE(hs));
1542    if (err == ERR_OK) {
1543      data_to_send = 1;
1544      hs->file += len;
1545      hs->left -= len;
1546    }
1547  }
1548  return data_to_send;
1549}
1550#endif /* LWIP_HTTPD_SSI */
1551
1552/**
1553 * Try to send more data on this pcb.
1554 *
1555 * @param pcb the pcb to send data
1556 * @param hs connection state
1557 */
1558static u8_t
1559http_send(struct altcp_pcb *pcb, struct http_state *hs)
1560{
1561  u8_t data_to_send = HTTP_NO_DATA_TO_SEND;
1562
1563  LWIP_DEBUGF(HTTPD_DEBUG | LWIP_DBG_TRACE, ("http_send: pcb=%p hs=%p left=%d\n", (void *)pcb,
1564              (void *)hs, hs != NULL ? (int)hs->left : 0));
1565
1566#if LWIP_HTTPD_SUPPORT_POST && LWIP_HTTPD_POST_MANUAL_WND
1567  if (hs->unrecved_bytes != 0) {
1568    return 0;
1569  }
1570#endif /* LWIP_HTTPD_SUPPORT_POST && LWIP_HTTPD_POST_MANUAL_WND */
1571
1572  /* If we were passed a NULL state structure pointer, ignore the call. */
1573  if (hs == NULL) {
1574    return 0;
1575  }
1576
1577#if LWIP_HTTPD_FS_ASYNC_READ
1578  /* Check if we are allowed to read from this file.
1579     (e.g. SSI might want to delay sending until data is available) */
1580  if (!fs_is_file_ready(hs->handle, http_continue, hs)) {
1581    return 0;
1582  }
1583#endif /* LWIP_HTTPD_FS_ASYNC_READ */
1584
1585#if LWIP_HTTPD_DYNAMIC_HEADERS
1586  /* Do we have any more header data to send for this file? */
1587  if (hs->hdr_index < NUM_FILE_HDR_STRINGS) {
1588    data_to_send = http_send_headers(pcb, hs);
1589    if ((data_to_send == HTTP_DATA_TO_SEND_FREED) ||
1590        ((data_to_send != HTTP_DATA_TO_SEND_CONTINUE) &&
1591         (hs->hdr_index < NUM_FILE_HDR_STRINGS))) {
1592      return data_to_send;
1593    }
1594  }
1595#endif /* LWIP_HTTPD_DYNAMIC_HEADERS */
1596
1597  /* Have we run out of file data to send? If so, we need to read the next
1598   * block from the file. */
1599  if (hs->left == 0) {
1600    if (!http_check_eof(pcb, hs)) {
1601      return 0;
1602    }
1603  }
1604
1605#if LWIP_HTTPD_SSI
1606  if (hs->ssi) {
1607    data_to_send = http_send_data_ssi(pcb, hs);
1608  } else
1609#endif /* LWIP_HTTPD_SSI */
1610  {
1611    data_to_send = http_send_data_nonssi(pcb, hs);
1612  }
1613
1614  if ((hs->left == 0) && (fs_bytes_left(hs->handle) <= 0)) {
1615    /* We reached the end of the file so this request is done.
1616     * This adds the FIN flag right into the last data segment. */
1617    LWIP_DEBUGF(HTTPD_DEBUG, ("End of file.\n"));
1618    http_eof(pcb, hs);
1619    return 0;
1620  }
1621  LWIP_DEBUGF(HTTPD_DEBUG | LWIP_DBG_TRACE, ("send_data end.\n"));
1622  return data_to_send;
1623}
1624
1625#if LWIP_HTTPD_SUPPORT_EXTSTATUS
1626/** Initialize a http connection with a file to send for an error message
1627 *
1628 * @param hs http connection state
1629 * @param error_nr HTTP error number
1630 * @return ERR_OK if file was found and hs has been initialized correctly
1631 *         another err_t otherwise
1632 */
1633static err_t
1634http_find_error_file(struct http_state *hs, u16_t error_nr)
1635{
1636  const char *uri, *uri1, *uri2, *uri3;
1637
1638  if (error_nr == 501) {
1639    uri1 = "/501.html";
1640    uri2 = "/501.htm";
1641    uri3 = "/501.shtml";
1642  } else {
1643    /* 400 (bad request is the default) */
1644    uri1 = "/400.html";
1645    uri2 = "/400.htm";
1646    uri3 = "/400.shtml";
1647  }
1648  if (fs_open(&hs->file_handle, uri1) == ERR_OK) {
1649    uri = uri1;
1650  } else if (fs_open(&hs->file_handle, uri2) == ERR_OK) {
1651    uri = uri2;
1652  } else if (fs_open(&hs->file_handle, uri3) == ERR_OK) {
1653    uri = uri3;
1654  } else {
1655    LWIP_DEBUGF(HTTPD_DEBUG, ("Error page for error %"U16_F" not found\n",
1656                              error_nr));
1657    return ERR_ARG;
1658  }
1659  return http_init_file(hs, &hs->file_handle, 0, uri, 0, NULL);
1660}
1661#else /* LWIP_HTTPD_SUPPORT_EXTSTATUS */
1662#define http_find_error_file(hs, error_nr) ERR_ARG
1663#endif /* LWIP_HTTPD_SUPPORT_EXTSTATUS */
1664
1665/**
1666 * Get the file struct for a 404 error page.
1667 * Tries some file names and returns NULL if none found.
1668 *
1669 * @param uri pointer that receives the actual file name URI
1670 * @return file struct for the error page or NULL no matching file was found
1671 */
1672static struct fs_file *
1673http_get_404_file(struct http_state *hs, const char **uri)
1674{
1675  err_t err;
1676
1677  *uri = "/404.html";
1678  err = fs_open(&hs->file_handle, *uri);
1679  if (err != ERR_OK) {
1680    /* 404.html doesn't exist. Try 404.htm instead. */
1681    *uri = "/404.htm";
1682    err = fs_open(&hs->file_handle, *uri);
1683    if (err != ERR_OK) {
1684      /* 404.htm doesn't exist either. Try 404.shtml instead. */
1685      *uri = "/404.shtml";
1686      err = fs_open(&hs->file_handle, *uri);
1687      if (err != ERR_OK) {
1688        /* 404.htm doesn't exist either. Indicate to the caller that it should
1689         * send back a default 404 page.
1690         */
1691        *uri = NULL;
1692        return NULL;
1693      }
1694    }
1695  }
1696
1697  return &hs->file_handle;
1698}
1699
1700#if LWIP_HTTPD_SUPPORT_POST
1701static err_t
1702http_handle_post_finished(struct http_state *hs)
1703{
1704#if LWIP_HTTPD_POST_MANUAL_WND
1705  /* Prevent multiple calls to httpd_post_finished, since it might have already
1706     been called before from httpd_post_data_recved(). */
1707  if (hs->post_finished) {
1708    return ERR_OK;
1709  }
1710  hs->post_finished = 1;
1711#endif /* LWIP_HTTPD_POST_MANUAL_WND */
1712  /* application error or POST finished */
1713  /* NULL-terminate the buffer */
1714  http_uri_buf[0] = 0;
1715  httpd_post_finished(hs, http_uri_buf, LWIP_HTTPD_URI_BUF_LEN);
1716  return http_find_file(hs, http_uri_buf, 0);
1717}
1718
1719/** Pass received POST body data to the application and correctly handle
1720 * returning a response document or closing the connection.
1721 * ATTENTION: The application is responsible for the pbuf now, so don't free it!
1722 *
1723 * @param hs http connection state
1724 * @param p pbuf to pass to the application
1725 * @return ERR_OK if passed successfully, another err_t if the response file
1726 *         hasn't been found (after POST finished)
1727 */
1728static err_t
1729http_post_rxpbuf(struct http_state *hs, struct pbuf *p)
1730{
1731  err_t err;
1732
1733  if (p != NULL) {
1734    /* adjust remaining Content-Length */
1735    if (hs->post_content_len_left < p->tot_len) {
1736      hs->post_content_len_left = 0;
1737    } else {
1738      hs->post_content_len_left -= p->tot_len;
1739    }
1740  }
1741#if LWIP_HTTPD_SUPPORT_POST && LWIP_HTTPD_POST_MANUAL_WND
1742  /* prevent connection being closed if httpd_post_data_recved() is called nested */
1743  hs->unrecved_bytes++;
1744#endif
1745  if (p != NULL) {
1746    err = httpd_post_receive_data(hs, p);
1747  } else {
1748    err = ERR_OK;
1749  }
1750#if LWIP_HTTPD_SUPPORT_POST && LWIP_HTTPD_POST_MANUAL_WND
1751  hs->unrecved_bytes--;
1752#endif
1753  if (err != ERR_OK) {
1754    /* Ignore remaining content in case of application error */
1755    hs->post_content_len_left = 0;
1756  }
1757  if (hs->post_content_len_left == 0) {
1758#if LWIP_HTTPD_SUPPORT_POST && LWIP_HTTPD_POST_MANUAL_WND
1759    if (hs->unrecved_bytes != 0) {
1760      return ERR_OK;
1761    }
1762#endif /* LWIP_HTTPD_SUPPORT_POST && LWIP_HTTPD_POST_MANUAL_WND */
1763    /* application error or POST finished */
1764    return http_handle_post_finished(hs);
1765  }
1766
1767  return ERR_OK;
1768}
1769
1770/** Handle a post request. Called from http_parse_request when method 'POST'
1771 * is found.
1772 *
1773 * @param p The input pbuf (containing the POST header and body).
1774 * @param hs The http connection state.
1775 * @param data HTTP request (header and part of body) from input pbuf(s).
1776 * @param data_len Size of 'data'.
1777 * @param uri The HTTP URI parsed from input pbuf(s).
1778 * @param uri_end Pointer to the end of 'uri' (here, the rest of the HTTP
1779 *                header starts).
1780 * @return ERR_OK: POST correctly parsed and accepted by the application.
1781 *         ERR_INPROGRESS: POST not completely parsed (no error yet)
1782 *         another err_t: Error parsing POST or denied by the application
1783 */
1784static err_t
1785http_post_request(struct pbuf *inp, struct http_state *hs,
1786                  char *data, u16_t data_len, char *uri, char *uri_end)
1787{
1788  err_t err;
1789  /* search for end-of-header (first double-CRLF) */
1790  char *crlfcrlf = lwip_strnstr(uri_end + 1, CRLF CRLF, data_len - (uri_end + 1 - data));
1791
1792  if (crlfcrlf != NULL) {
1793    /* search for "Content-Length: " */
1794#define HTTP_HDR_CONTENT_LEN                "Content-Length: "
1795#define HTTP_HDR_CONTENT_LEN_LEN            16
1796#define HTTP_HDR_CONTENT_LEN_DIGIT_MAX_LEN  10
1797    char *scontent_len = lwip_strnstr(uri_end + 1, HTTP_HDR_CONTENT_LEN, crlfcrlf - (uri_end + 1));
1798    if (scontent_len != NULL) {
1799      char *scontent_len_end = lwip_strnstr(scontent_len + HTTP_HDR_CONTENT_LEN_LEN, CRLF, HTTP_HDR_CONTENT_LEN_DIGIT_MAX_LEN);
1800      if (scontent_len_end != NULL) {
1801        int content_len;
1802        char *content_len_num = scontent_len + HTTP_HDR_CONTENT_LEN_LEN;
1803        content_len = atoi(content_len_num);
1804        if (content_len == 0) {
1805          /* if atoi returns 0 on error, fix this */
1806          if ((content_len_num[0] != '0') || (content_len_num[1] != '\r')) {
1807            content_len = -1;
1808          }
1809        }
1810        if (content_len >= 0) {
1811          /* adjust length of HTTP header passed to application */
1812          const char *hdr_start_after_uri = uri_end + 1;
1813          u16_t hdr_len = (u16_t)LWIP_MIN(data_len, crlfcrlf + 4 - data);
1814          u16_t hdr_data_len = (u16_t)LWIP_MIN(data_len, crlfcrlf + 4 - hdr_start_after_uri);
1815          u8_t post_auto_wnd = 1;
1816          http_uri_buf[0] = 0;
1817          /* trim http header */
1818          *crlfcrlf = 0;
1819          err = httpd_post_begin(hs, uri, hdr_start_after_uri, hdr_data_len, content_len,
1820                                 http_uri_buf, LWIP_HTTPD_URI_BUF_LEN, &post_auto_wnd);
1821          if (err == ERR_OK) {
1822            /* try to pass in data of the first pbuf(s) */
1823            struct pbuf *q = inp;
1824            u16_t start_offset = hdr_len;
1825#if LWIP_HTTPD_POST_MANUAL_WND
1826            hs->no_auto_wnd = !post_auto_wnd;
1827#endif /* LWIP_HTTPD_POST_MANUAL_WND */
1828            /* set the Content-Length to be received for this POST */
1829            hs->post_content_len_left = (u32_t)content_len;
1830
1831            /* get to the pbuf where the body starts */
1832            while ((q != NULL) && (q->len <= start_offset)) {
1833              start_offset -= q->len;
1834              q = q->next;
1835            }
1836            if (q != NULL) {
1837              /* hide the remaining HTTP header */
1838              pbuf_remove_header(q, start_offset);
1839#if LWIP_HTTPD_POST_MANUAL_WND
1840              if (!post_auto_wnd) {
1841                /* already tcp_recved() this data... */
1842                hs->unrecved_bytes = q->tot_len;
1843              }
1844#endif /* LWIP_HTTPD_POST_MANUAL_WND */
1845              pbuf_ref(q);
1846              return http_post_rxpbuf(hs, q);
1847            } else if (hs->post_content_len_left == 0) {
1848              q = pbuf_alloc(PBUF_RAW, 0, PBUF_REF);
1849              return http_post_rxpbuf(hs, q);
1850            } else {
1851              return ERR_OK;
1852            }
1853          } else {
1854            /* return file passed from application */
1855            return http_find_file(hs, http_uri_buf, 0);
1856          }
1857        } else {
1858          LWIP_DEBUGF(HTTPD_DEBUG, ("POST received invalid Content-Length: %s\n",
1859                                    content_len_num));
1860          return ERR_ARG;
1861        }
1862      }
1863    }
1864    /* If we come here, headers are fully received (double-crlf), but Content-Length
1865       was not included. Since this is currently the only supported method, we have
1866       to fail in this case! */
1867    LWIP_DEBUGF(HTTPD_DEBUG, ("Error when parsing Content-Length\n"));
1868    return ERR_ARG;
1869  }
1870  /* if we come here, the POST is incomplete */
1871#if LWIP_HTTPD_SUPPORT_REQUESTLIST
1872  return ERR_INPROGRESS;
1873#else /* LWIP_HTTPD_SUPPORT_REQUESTLIST */
1874  return ERR_ARG;
1875#endif /* LWIP_HTTPD_SUPPORT_REQUESTLIST */
1876}
1877
1878#if LWIP_HTTPD_POST_MANUAL_WND
1879/**
1880 * @ingroup httpd
1881 * A POST implementation can call this function to update the TCP window.
1882 * This can be used to throttle data reception (e.g. when received data is
1883 * programmed to flash and data is received faster than programmed).
1884 *
1885 * @param connection A connection handle passed to httpd_post_begin for which
1886 *        httpd_post_finished has *NOT* been called yet!
1887 * @param recved_len Length of data received (for window update)
1888 */
1889void httpd_post_data_recved(void *connection, u16_t recved_len)
1890{
1891  struct http_state *hs = (struct http_state *)connection;
1892  if (hs != NULL) {
1893    if (hs->no_auto_wnd) {
1894      u16_t len = recved_len;
1895      if (hs->unrecved_bytes >= recved_len) {
1896        hs->unrecved_bytes -= recved_len;
1897      } else {
1898        LWIP_DEBUGF(HTTPD_DEBUG | LWIP_DBG_LEVEL_WARNING, ("httpd_post_data_recved: recved_len too big\n"));
1899        len = (u16_t)hs->unrecved_bytes;
1900        hs->unrecved_bytes = 0;
1901      }
1902      if (hs->pcb != NULL) {
1903        if (len != 0) {
1904          altcp_recved(hs->pcb, len);
1905        }
1906        if ((hs->post_content_len_left == 0) && (hs->unrecved_bytes == 0)) {
1907          /* finished handling POST */
1908          http_handle_post_finished(hs);
1909          http_send(hs->pcb, hs);
1910        }
1911      }
1912    }
1913  }
1914}
1915#endif /* LWIP_HTTPD_POST_MANUAL_WND */
1916
1917#endif /* LWIP_HTTPD_SUPPORT_POST */
1918
1919#if LWIP_HTTPD_FS_ASYNC_READ
1920/** Try to send more data if file has been blocked before
1921 * This is a callback function passed to fs_read_async().
1922 */
1923static void
1924http_continue(void *connection)
1925{
1926  struct http_state *hs = (struct http_state *)connection;
1927  LWIP_ASSERT_CORE_LOCKED();
1928  if (hs && (hs->pcb) && (hs->handle)) {
1929    LWIP_ASSERT("hs->pcb != NULL", hs->pcb != NULL);
1930    LWIP_DEBUGF(HTTPD_DEBUG | LWIP_DBG_TRACE, ("httpd_continue: try to send more data\n"));
1931    if (http_send(hs->pcb, hs)) {
1932      /* If we wrote anything to be sent, go ahead and send it now. */
1933      LWIP_DEBUGF(HTTPD_DEBUG | LWIP_DBG_TRACE, ("tcp_output\n"));
1934      altcp_output(hs->pcb);
1935    }
1936  }
1937}
1938#endif /* LWIP_HTTPD_FS_ASYNC_READ */
1939
1940/**
1941 * When data has been received in the correct state, try to parse it
1942 * as a HTTP request.
1943 *
1944 * @param inp the received pbuf
1945 * @param hs the connection state
1946 * @param pcb the altcp_pcb which received this packet
1947 * @return ERR_OK if request was OK and hs has been initialized correctly
1948 *         ERR_INPROGRESS if request was OK so far but not fully received
1949 *         another err_t otherwise
1950 */
1951static err_t
1952http_parse_request(struct pbuf *inp, struct http_state *hs, struct altcp_pcb *pcb)
1953{
1954  char *data;
1955  char *crlf;
1956  u16_t data_len;
1957  struct pbuf *p = inp;
1958#if LWIP_HTTPD_SUPPORT_REQUESTLIST
1959  u16_t clen;
1960#endif /* LWIP_HTTPD_SUPPORT_REQUESTLIST */
1961#if LWIP_HTTPD_SUPPORT_POST
1962  err_t err;
1963#endif /* LWIP_HTTPD_SUPPORT_POST */
1964
1965  LWIP_UNUSED_ARG(pcb); /* only used for post */
1966  LWIP_ASSERT("p != NULL", p != NULL);
1967  LWIP_ASSERT("hs != NULL", hs != NULL);
1968
1969  if ((hs->handle != NULL) || (hs->file != NULL)) {
1970    LWIP_DEBUGF(HTTPD_DEBUG, ("Received data while sending a file\n"));
1971    /* already sending a file */
1972    /* @todo: abort? */
1973    return ERR_USE;
1974  }
1975
1976#if LWIP_HTTPD_SUPPORT_REQUESTLIST
1977
1978  LWIP_DEBUGF(HTTPD_DEBUG, ("Received %"U16_F" bytes\n", p->tot_len));
1979
1980  /* first check allowed characters in this pbuf? */
1981
1982  /* enqueue the pbuf */
1983  if (hs->req == NULL) {
1984    LWIP_DEBUGF(HTTPD_DEBUG, ("First pbuf\n"));
1985    hs->req = p;
1986  } else {
1987    LWIP_DEBUGF(HTTPD_DEBUG, ("pbuf enqueued\n"));
1988    pbuf_cat(hs->req, p);
1989  }
1990  /* increase pbuf ref counter as it is freed when we return but we want to
1991     keep it on the req list */
1992  pbuf_ref(p);
1993
1994  if (hs->req->next != NULL) {
1995    data_len = LWIP_MIN(hs->req->tot_len, LWIP_HTTPD_MAX_REQ_LENGTH);
1996    pbuf_copy_partial(hs->req, httpd_req_buf, data_len, 0);
1997    data = httpd_req_buf;
1998  } else
1999#endif /* LWIP_HTTPD_SUPPORT_REQUESTLIST */
2000  {
2001    data = (char *)p->payload;
2002    data_len = p->len;
2003    if (p->len != p->tot_len) {
2004      LWIP_DEBUGF(HTTPD_DEBUG, ("Warning: incomplete header due to chained pbufs\n"));
2005    }
2006  }
2007
2008  /* received enough data for minimal request? */
2009  if (data_len >= MIN_REQ_LEN) {
2010    /* wait for CRLF before parsing anything */
2011    crlf = lwip_strnstr(data, CRLF, data_len);
2012    if (crlf != NULL) {
2013#if LWIP_HTTPD_SUPPORT_POST
2014      int is_post = 0;
2015#endif /* LWIP_HTTPD_SUPPORT_POST */
2016      int is_09 = 0;
2017      char *sp1, *sp2;
2018      u16_t left_len, uri_len;
2019      LWIP_DEBUGF(HTTPD_DEBUG | LWIP_DBG_TRACE, ("CRLF received, parsing request\n"));
2020      /* parse method */
2021      if (!strncmp(data, "GET ", 4)) {
2022        sp1 = data + 3;
2023        /* received GET request */
2024        LWIP_DEBUGF(HTTPD_DEBUG | LWIP_DBG_TRACE, ("Received GET request\"\n"));
2025#if LWIP_HTTPD_SUPPORT_POST
2026      } else if (!strncmp(data, "POST ", 5)) {
2027        /* store request type */
2028        is_post = 1;
2029        sp1 = data + 4;
2030        /* received GET request */
2031        LWIP_DEBUGF(HTTPD_DEBUG | LWIP_DBG_TRACE, ("Received POST request\n"));
2032#endif /* LWIP_HTTPD_SUPPORT_POST */
2033      } else {
2034        /* null-terminate the METHOD (pbuf is freed anyway wen returning) */
2035        data[4] = 0;
2036        /* unsupported method! */
2037        LWIP_DEBUGF(HTTPD_DEBUG, ("Unsupported request method (not implemented): \"%s\"\n",
2038                                  data));
2039        return http_find_error_file(hs, 501);
2040      }
2041      /* if we come here, method is OK, parse URI */
2042      left_len = (u16_t)(data_len - ((sp1 + 1) - data));
2043      sp2 = lwip_strnstr(sp1 + 1, " ", left_len);
2044#if LWIP_HTTPD_SUPPORT_V09
2045      if (sp2 == NULL) {
2046        /* HTTP 0.9: respond with correct protocol version */
2047        sp2 = lwip_strnstr(sp1 + 1, CRLF, left_len);
2048        is_09 = 1;
2049#if LWIP_HTTPD_SUPPORT_POST
2050        if (is_post) {
2051          /* HTTP/0.9 does not support POST */
2052          goto badrequest;
2053        }
2054#endif /* LWIP_HTTPD_SUPPORT_POST */
2055      }
2056#endif /* LWIP_HTTPD_SUPPORT_V09 */
2057      uri_len = (u16_t)(sp2 - (sp1 + 1));
2058      if ((sp2 != 0) && (sp2 > sp1)) {
2059        /* wait for CRLFCRLF (indicating end of HTTP headers) before parsing anything */
2060        if (lwip_strnstr(data, CRLF CRLF, data_len) != NULL) {
2061          char *uri = sp1 + 1;
2062#if LWIP_HTTPD_SUPPORT_11_KEEPALIVE
2063          /* This is HTTP/1.0 compatible: for strict 1.1, a connection
2064             would always be persistent unless "close" was specified. */
2065          if (!is_09 && (lwip_strnstr(data, HTTP11_CONNECTIONKEEPALIVE, data_len) ||
2066                         lwip_strnstr(data, HTTP11_CONNECTIONKEEPALIVE2, data_len))) {
2067            hs->keepalive = 1;
2068          } else {
2069            hs->keepalive = 0;
2070          }
2071#endif /* LWIP_HTTPD_SUPPORT_11_KEEPALIVE */
2072          /* null-terminate the METHOD (pbuf is freed anyway wen returning) */
2073          *sp1 = 0;
2074          uri[uri_len] = 0;
2075          LWIP_DEBUGF(HTTPD_DEBUG, ("Received \"%s\" request for URI: \"%s\"\n",
2076                                    data, uri));
2077#if LWIP_HTTPD_SUPPORT_POST
2078          if (is_post) {
2079#if LWIP_HTTPD_SUPPORT_REQUESTLIST
2080            struct pbuf *q = hs->req;
2081#else /* LWIP_HTTPD_SUPPORT_REQUESTLIST */
2082            struct pbuf *q = inp;
2083#endif /* LWIP_HTTPD_SUPPORT_REQUESTLIST */
2084            err = http_post_request(q, hs, data, data_len, uri, sp2);
2085            if (err != ERR_OK) {
2086              /* restore header for next try */
2087              *sp1 = ' ';
2088              *sp2 = ' ';
2089              uri[uri_len] = ' ';
2090            }
2091            if (err == ERR_ARG) {
2092              goto badrequest;
2093            }
2094            return err;
2095          } else
2096#endif /* LWIP_HTTPD_SUPPORT_POST */
2097          {
2098            return http_find_file(hs, uri, is_09);
2099          }
2100        }
2101      } else {
2102        LWIP_DEBUGF(HTTPD_DEBUG, ("invalid URI\n"));
2103      }
2104    }
2105  }
2106
2107#if LWIP_HTTPD_SUPPORT_REQUESTLIST
2108  clen = pbuf_clen(hs->req);
2109  if ((hs->req->tot_len <= LWIP_HTTPD_REQ_BUFSIZE) &&
2110      (clen <= LWIP_HTTPD_REQ_QUEUELEN)) {
2111    /* request not fully received (too short or CRLF is missing) */
2112    return ERR_INPROGRESS;
2113  } else
2114#endif /* LWIP_HTTPD_SUPPORT_REQUESTLIST */
2115  {
2116#if LWIP_HTTPD_SUPPORT_POST
2117badrequest:
2118#endif /* LWIP_HTTPD_SUPPORT_POST */
2119    LWIP_DEBUGF(HTTPD_DEBUG, ("bad request\n"));
2120    /* could not parse request */
2121    return http_find_error_file(hs, 400);
2122  }
2123}
2124
2125#if LWIP_HTTPD_SSI && (LWIP_HTTPD_SSI_BY_FILE_EXTENSION == 1)
2126/* Check if SSI should be parsed for this file/URL
2127 * (With LWIP_HTTPD_SSI_BY_FILE_EXTENSION == 2, this function can be
2128 * overridden by an external implementation.)
2129 *
2130 * @return 1 for SSI, 0 for standard files
2131 */
2132static u8_t
2133http_uri_is_ssi(struct fs_file *file, const char *uri)
2134{
2135  size_t loop;
2136  u8_t tag_check = 0;
2137  if (file != NULL) {
2138    /* See if we have been asked for an shtml file and, if so,
2139        enable tag checking. */
2140    const char *ext = NULL, *sub;
2141    char *param = (char *)strstr(uri, "?");
2142    if (param != NULL) {
2143      /* separate uri from parameters for now, set back later */
2144      *param = 0;
2145    }
2146    sub = uri;
2147    ext = uri;
2148    for (sub = strstr(sub, "."); sub != NULL; sub = strstr(sub, ".")) {
2149      ext = sub;
2150      sub++;
2151    }
2152    for (loop = 0; loop < NUM_SHTML_EXTENSIONS; loop++) {
2153      if (!lwip_stricmp(ext, g_pcSSIExtensions[loop])) {
2154        tag_check = 1;
2155        break;
2156      }
2157    }
2158    if (param != NULL) {
2159      *param = '?';
2160    }
2161  }
2162  return tag_check;
2163}
2164#endif /* LWIP_HTTPD_SSI */
2165
2166/** Try to find the file specified by uri and, if found, initialize hs
2167 * accordingly.
2168 *
2169 * @param hs the connection state
2170 * @param uri the HTTP header URI
2171 * @param is_09 1 if the request is HTTP/0.9 (no HTTP headers in response)
2172 * @return ERR_OK if file was found and hs has been initialized correctly
2173 *         another err_t otherwise
2174 */
2175static err_t
2176http_find_file(struct http_state *hs, const char *uri, int is_09)
2177{
2178  size_t loop;
2179  struct fs_file *file = NULL;
2180  char *params = NULL;
2181  err_t err;
2182#if LWIP_HTTPD_CGI
2183  int i;
2184#endif /* LWIP_HTTPD_CGI */
2185#if !LWIP_HTTPD_SSI
2186  const
2187#endif /* !LWIP_HTTPD_SSI */
2188  /* By default, assume we will not be processing server-side-includes tags */
2189  u8_t tag_check = 0;
2190
2191  /* Have we been asked for the default file (in root or a directory) ? */
2192#if LWIP_HTTPD_MAX_REQUEST_URI_LEN
2193  size_t uri_len = strlen(uri);
2194  if ((uri_len > 0) && (uri[uri_len - 1] == '/') &&
2195      ((uri != http_uri_buf) || (uri_len == 1))) {
2196    size_t copy_len = LWIP_MIN(sizeof(http_uri_buf) - 1, uri_len - 1);
2197    if (copy_len > 0) {
2198      MEMCPY(http_uri_buf, uri, copy_len);
2199      http_uri_buf[copy_len] = 0;
2200    }
2201#else /* LWIP_HTTPD_MAX_REQUEST_URI_LEN */
2202  if ((uri[0] == '/') &&  (uri[1] == 0)) {
2203#endif /* LWIP_HTTPD_MAX_REQUEST_URI_LEN */
2204    /* Try each of the configured default filenames until we find one
2205       that exists. */
2206    for (loop = 0; loop < NUM_DEFAULT_FILENAMES; loop++) {
2207      const char *file_name;
2208#if LWIP_HTTPD_MAX_REQUEST_URI_LEN
2209      if (copy_len > 0) {
2210        size_t len_left = sizeof(http_uri_buf) - copy_len - 1;
2211        if (len_left > 0) {
2212          size_t name_len = strlen(httpd_default_filenames[loop].name);
2213          size_t name_copy_len = LWIP_MIN(len_left, name_len);
2214          MEMCPY(&http_uri_buf[copy_len], httpd_default_filenames[loop].name, name_copy_len);
2215          http_uri_buf[copy_len + name_copy_len] = 0;
2216        }
2217        file_name = http_uri_buf;
2218      } else
2219#endif /* LWIP_HTTPD_MAX_REQUEST_URI_LEN */
2220      {
2221        file_name = httpd_default_filenames[loop].name;
2222      }
2223      LWIP_DEBUGF(HTTPD_DEBUG | LWIP_DBG_TRACE, ("Looking for %s...\n", file_name));
2224      err = fs_open(&hs->file_handle, file_name);
2225      if (err == ERR_OK) {
2226        uri = file_name;
2227        file = &hs->file_handle;
2228        LWIP_DEBUGF(HTTPD_DEBUG | LWIP_DBG_TRACE, ("Opened.\n"));
2229#if LWIP_HTTPD_SSI
2230        tag_check = httpd_default_filenames[loop].shtml;
2231#endif /* LWIP_HTTPD_SSI */
2232        break;
2233      }
2234    }
2235  }
2236  if (file == NULL) {
2237    /* No - we've been asked for a specific file. */
2238    /* First, isolate the base URI (without any parameters) */
2239    params = (char *)strchr(uri, '?');
2240    if (params != NULL) {
2241      /* URI contains parameters. NULL-terminate the base URI */
2242      *params = '\0';
2243      params++;
2244    }
2245
2246#if LWIP_HTTPD_CGI
2247    http_cgi_paramcount = -1;
2248    /* Does the base URI we have isolated correspond to a CGI handler? */
2249    if (httpd_num_cgis && httpd_cgis) {
2250      for (i = 0; i < httpd_num_cgis; i++) {
2251        if (strcmp(uri, httpd_cgis[i].pcCGIName) == 0) {
2252          /*
2253           * We found a CGI that handles this URI so extract the
2254           * parameters and call the handler.
2255           */
2256          http_cgi_paramcount = extract_uri_parameters(hs, params);
2257          uri = httpd_cgis[i].pfnCGIHandler(i, http_cgi_paramcount, hs->params,
2258                                         hs->param_vals);
2259          break;
2260        }
2261      }
2262    }
2263#endif /* LWIP_HTTPD_CGI */
2264
2265    LWIP_DEBUGF(HTTPD_DEBUG | LWIP_DBG_TRACE, ("Opening %s\n", uri));
2266
2267    err = fs_open(&hs->file_handle, uri);
2268    if (err == ERR_OK) {
2269      file = &hs->file_handle;
2270    } else {
2271      file = http_get_404_file(hs, &uri);
2272    }
2273#if LWIP_HTTPD_SSI
2274    if (file != NULL) {
2275      if (file->flags & FS_FILE_FLAGS_SSI) {
2276        tag_check = 1;
2277      } else {
2278#if LWIP_HTTPD_SSI_BY_FILE_EXTENSION
2279        tag_check = http_uri_is_ssi(file, uri);
2280#endif /* LWIP_HTTPD_SSI_BY_FILE_EXTENSION */
2281      }
2282    }
2283#endif /* LWIP_HTTPD_SSI */
2284  }
2285  if (file == NULL) {
2286    /* None of the default filenames exist so send back a 404 page */
2287    file = http_get_404_file(hs, &uri);
2288  }
2289  return http_init_file(hs, file, is_09, uri, tag_check, params);
2290}
2291
2292/** Initialize a http connection with a file to send (if found).
2293 * Called by http_find_file and http_find_error_file.
2294 *
2295 * @param hs http connection state
2296 * @param file file structure to send (or NULL if not found)
2297 * @param is_09 1 if the request is HTTP/0.9 (no HTTP headers in response)
2298 * @param uri the HTTP header URI
2299 * @param tag_check enable SSI tag checking
2300 * @param params != NULL if URI has parameters (separated by '?')
2301 * @return ERR_OK if file was found and hs has been initialized correctly
2302 *         another err_t otherwise
2303 */
2304static err_t
2305http_init_file(struct http_state *hs, struct fs_file *file, int is_09, const char *uri,
2306               u8_t tag_check, char *params)
2307{
2308#if !LWIP_HTTPD_SUPPORT_V09
2309  LWIP_UNUSED_ARG(is_09);
2310#endif
2311  if (file != NULL) {
2312    /* file opened, initialise struct http_state */
2313#if !LWIP_HTTPD_DYNAMIC_FILE_READ
2314    /* If dynamic read is disabled, file data must be in one piece and available now */
2315    LWIP_ASSERT("file->data != NULL", file->data != NULL);
2316#endif
2317
2318#if LWIP_HTTPD_SSI
2319    if (tag_check) {
2320      struct http_ssi_state *ssi = http_ssi_state_alloc();
2321      if (ssi != NULL) {
2322        ssi->tag_index = 0;
2323        ssi->tag_state = TAG_NONE;
2324        ssi->parsed = file->data;
2325        ssi->parse_left = file->len;
2326        ssi->tag_end = file->data;
2327        hs->ssi = ssi;
2328      }
2329    }
2330#else /* LWIP_HTTPD_SSI */
2331    LWIP_UNUSED_ARG(tag_check);
2332#endif /* LWIP_HTTPD_SSI */
2333    hs->handle = file;
2334#if LWIP_HTTPD_CGI_SSI
2335    if (params != NULL) {
2336      /* URI contains parameters, call generic CGI handler */
2337      int count;
2338#if LWIP_HTTPD_CGI
2339      if (http_cgi_paramcount >= 0) {
2340        count = http_cgi_paramcount;
2341      } else
2342#endif
2343      {
2344        count = extract_uri_parameters(hs, params);
2345      }
2346      httpd_cgi_handler(file, uri, count, http_cgi_params, http_cgi_param_vals
2347#if defined(LWIP_HTTPD_FILE_STATE) && LWIP_HTTPD_FILE_STATE
2348                        , file->state
2349#endif /* LWIP_HTTPD_FILE_STATE */
2350                       );
2351    }
2352#else /* LWIP_HTTPD_CGI_SSI */
2353    LWIP_UNUSED_ARG(params);
2354#endif /* LWIP_HTTPD_CGI_SSI */
2355    hs->file = file->data;
2356    LWIP_ASSERT("File length must be positive!", (file->len >= 0));
2357#if LWIP_HTTPD_CUSTOM_FILES
2358    if (file->is_custom_file && (file->data == NULL)) {
2359      /* custom file, need to read data first (via fs_read_custom) */
2360      hs->left = 0;
2361    } else
2362#endif /* LWIP_HTTPD_CUSTOM_FILES */
2363    {
2364      hs->left = (u32_t)file->len;
2365    }
2366    hs->retries = 0;
2367#if LWIP_HTTPD_TIMING
2368    hs->time_started = sys_now();
2369#endif /* LWIP_HTTPD_TIMING */
2370#if !LWIP_HTTPD_DYNAMIC_HEADERS
2371    LWIP_ASSERT("HTTP headers not included in file system",
2372                (hs->handle->flags & FS_FILE_FLAGS_HEADER_INCLUDED) != 0);
2373#endif /* !LWIP_HTTPD_DYNAMIC_HEADERS */
2374#if LWIP_HTTPD_SUPPORT_V09
2375    if (is_09 && ((hs->handle->flags & FS_FILE_FLAGS_HEADER_INCLUDED) != 0)) {
2376      /* HTTP/0.9 responses are sent without HTTP header,
2377         search for the end of the header. */
2378      char *file_start = lwip_strnstr(hs->file, CRLF CRLF, hs->left);
2379      if (file_start != NULL) {
2380        int diff = file_start + 4 - hs->file;
2381        hs->file += diff;
2382        hs->left -= (u32_t)diff;
2383      }
2384    }
2385#endif /* LWIP_HTTPD_SUPPORT_V09*/
2386  } else {
2387    hs->handle = NULL;
2388    hs->file = NULL;
2389    hs->left = 0;
2390    hs->retries = 0;
2391  }
2392#if LWIP_HTTPD_DYNAMIC_HEADERS
2393  /* Determine the HTTP headers to send based on the file extension of
2394   * the requested URI. */
2395  if ((hs->handle == NULL) || ((hs->handle->flags & FS_FILE_FLAGS_HEADER_INCLUDED) == 0)) {
2396    get_http_headers(hs, uri);
2397  }
2398#else /* LWIP_HTTPD_DYNAMIC_HEADERS */
2399  LWIP_UNUSED_ARG(uri);
2400#endif /* LWIP_HTTPD_DYNAMIC_HEADERS */
2401#if LWIP_HTTPD_SUPPORT_11_KEEPALIVE
2402  if (hs->keepalive) {
2403#if LWIP_HTTPD_SSI
2404    if (hs->ssi != NULL) {
2405      hs->keepalive = 0;
2406    } else
2407#endif /* LWIP_HTTPD_SSI */
2408    {
2409      if ((hs->handle != NULL) &&
2410          ((hs->handle->flags & (FS_FILE_FLAGS_HEADER_INCLUDED | FS_FILE_FLAGS_HEADER_PERSISTENT)) == FS_FILE_FLAGS_HEADER_INCLUDED)) {
2411        hs->keepalive = 0;
2412      }
2413    }
2414  }
2415#endif /* LWIP_HTTPD_SUPPORT_11_KEEPALIVE */
2416  return ERR_OK;
2417}
2418
2419/**
2420 * The pcb had an error and is already deallocated.
2421 * The argument might still be valid (if != NULL).
2422 */
2423static void
2424http_err(void *arg, err_t err)
2425{
2426  struct http_state *hs = (struct http_state *)arg;
2427  LWIP_UNUSED_ARG(err);
2428
2429  LWIP_DEBUGF(HTTPD_DEBUG, ("http_err: %s", lwip_strerr(err)));
2430
2431  if (hs != NULL) {
2432    http_state_free(hs);
2433  }
2434}
2435
2436/**
2437 * Data has been sent and acknowledged by the remote host.
2438 * This means that more data can be sent.
2439 */
2440static err_t
2441http_sent(void *arg, struct altcp_pcb *pcb, u16_t len)
2442{
2443  struct http_state *hs = (struct http_state *)arg;
2444
2445  LWIP_DEBUGF(HTTPD_DEBUG | LWIP_DBG_TRACE, ("http_sent %p\n", (void *)pcb));
2446
2447  LWIP_UNUSED_ARG(len);
2448
2449  if (hs == NULL) {
2450    return ERR_OK;
2451  }
2452
2453  hs->retries = 0;
2454
2455  http_send(pcb, hs);
2456
2457  return ERR_OK;
2458}
2459
2460/**
2461 * The poll function is called every 2nd second.
2462 * If there has been no data sent (which resets the retries) in 8 seconds, close.
2463 * If the last portion of a file has not been sent in 2 seconds, close.
2464 *
2465 * This could be increased, but we don't want to waste resources for bad connections.
2466 */
2467static err_t
2468http_poll(void *arg, struct altcp_pcb *pcb)
2469{
2470  struct http_state *hs = (struct http_state *)arg;
2471  LWIP_DEBUGF(HTTPD_DEBUG | LWIP_DBG_TRACE, ("http_poll: pcb=%p hs=%p pcb_state=%s\n",
2472              (void *)pcb, (void *)hs, tcp_debug_state_str(altcp_dbg_get_tcp_state(pcb))));
2473
2474  if (hs == NULL) {
2475    err_t closed;
2476    /* arg is null, close. */
2477    LWIP_DEBUGF(HTTPD_DEBUG, ("http_poll: arg is NULL, close\n"));
2478    closed = http_close_conn(pcb, NULL);
2479    LWIP_UNUSED_ARG(closed);
2480#if LWIP_HTTPD_ABORT_ON_CLOSE_MEM_ERROR
2481    if (closed == ERR_MEM) {
2482      altcp_abort(pcb);
2483      return ERR_ABRT;
2484    }
2485#endif /* LWIP_HTTPD_ABORT_ON_CLOSE_MEM_ERROR */
2486    return ERR_OK;
2487  } else {
2488    hs->retries++;
2489    if (hs->retries == HTTPD_MAX_RETRIES) {
2490      LWIP_DEBUGF(HTTPD_DEBUG, ("http_poll: too many retries, close\n"));
2491      http_close_conn(pcb, hs);
2492      return ERR_OK;
2493    }
2494
2495    /* If this connection has a file open, try to send some more data. If
2496     * it has not yet received a GET request, don't do this since it will
2497     * cause the connection to close immediately. */
2498    if (hs->handle) {
2499      LWIP_DEBUGF(HTTPD_DEBUG | LWIP_DBG_TRACE, ("http_poll: try to send more data\n"));
2500      if (http_send(pcb, hs)) {
2501        /* If we wrote anything to be sent, go ahead and send it now. */
2502        LWIP_DEBUGF(HTTPD_DEBUG | LWIP_DBG_TRACE, ("tcp_output\n"));
2503        altcp_output(pcb);
2504      }
2505    }
2506  }
2507
2508  return ERR_OK;
2509}
2510
2511/**
2512 * Data has been received on this pcb.
2513 * For HTTP 1.0, this should normally only happen once (if the request fits in one packet).
2514 */
2515static err_t
2516http_recv(void *arg, struct altcp_pcb *pcb, struct pbuf *p, err_t err)
2517{
2518  struct http_state *hs = (struct http_state *)arg;
2519  LWIP_DEBUGF(HTTPD_DEBUG | LWIP_DBG_TRACE, ("http_recv: pcb=%p pbuf=%p err=%s\n", (void *)pcb,
2520              (void *)p, lwip_strerr(err)));
2521
2522  if ((err != ERR_OK) || (p == NULL) || (hs == NULL)) {
2523    /* error or closed by other side? */
2524    if (p != NULL) {
2525      /* Inform TCP that we have taken the data. */
2526      altcp_recved(pcb, p->tot_len);
2527      pbuf_free(p);
2528    }
2529    if (hs == NULL) {
2530      /* this should not happen, only to be robust */
2531      LWIP_DEBUGF(HTTPD_DEBUG, ("Error, http_recv: hs is NULL, close\n"));
2532    }
2533    http_close_conn(pcb, hs);
2534    return ERR_OK;
2535  }
2536
2537#if LWIP_HTTPD_SUPPORT_POST && LWIP_HTTPD_POST_MANUAL_WND
2538  if (hs->no_auto_wnd) {
2539    hs->unrecved_bytes += p->tot_len;
2540  } else
2541#endif /* LWIP_HTTPD_SUPPORT_POST && LWIP_HTTPD_POST_MANUAL_WND */
2542  {
2543    /* Inform TCP that we have taken the data. */
2544    altcp_recved(pcb, p->tot_len);
2545  }
2546
2547#if LWIP_HTTPD_SUPPORT_POST
2548  if (hs->post_content_len_left > 0) {
2549    /* reset idle counter when POST data is received */
2550    hs->retries = 0;
2551    /* this is data for a POST, pass the complete pbuf to the application */
2552    http_post_rxpbuf(hs, p);
2553    /* pbuf is passed to the application, don't free it! */
2554    if (hs->post_content_len_left == 0) {
2555      /* all data received, send response or close connection */
2556      http_send(pcb, hs);
2557    }
2558    return ERR_OK;
2559  } else
2560#endif /* LWIP_HTTPD_SUPPORT_POST */
2561  {
2562    if (hs->handle == NULL) {
2563      err_t parsed = http_parse_request(p, hs, pcb);
2564      LWIP_ASSERT("http_parse_request: unexpected return value", parsed == ERR_OK
2565                  || parsed == ERR_INPROGRESS || parsed == ERR_ARG || parsed == ERR_USE);
2566#if LWIP_HTTPD_SUPPORT_REQUESTLIST
2567      if (parsed != ERR_INPROGRESS) {
2568        /* request fully parsed or error */
2569        if (hs->req != NULL) {
2570          pbuf_free(hs->req);
2571          hs->req = NULL;
2572        }
2573      }
2574#endif /* LWIP_HTTPD_SUPPORT_REQUESTLIST */
2575      pbuf_free(p);
2576      if (parsed == ERR_OK) {
2577#if LWIP_HTTPD_SUPPORT_POST
2578        if (hs->post_content_len_left == 0)
2579#endif /* LWIP_HTTPD_SUPPORT_POST */
2580        {
2581          LWIP_DEBUGF(HTTPD_DEBUG | LWIP_DBG_TRACE, ("http_recv: data %p len %"S32_F"\n", (const void *)hs->file, hs->left));
2582          http_send(pcb, hs);
2583        }
2584      } else if (parsed == ERR_ARG) {
2585        /* @todo: close on ERR_USE? */
2586        http_close_conn(pcb, hs);
2587      }
2588    } else {
2589      LWIP_DEBUGF(HTTPD_DEBUG, ("http_recv: already sending data\n"));
2590      /* already sending but still receiving data, we might want to RST here? */
2591      pbuf_free(p);
2592    }
2593  }
2594  return ERR_OK;
2595}
2596
2597/**
2598 * A new incoming connection has been accepted.
2599 */
2600static err_t
2601http_accept(void *arg, struct altcp_pcb *pcb, err_t err)
2602{
2603  struct http_state *hs;
2604  LWIP_UNUSED_ARG(err);
2605  LWIP_UNUSED_ARG(arg);
2606  LWIP_DEBUGF(HTTPD_DEBUG, ("http_accept %p / %p\n", (void *)pcb, arg));
2607
2608  if ((err != ERR_OK) || (pcb == NULL)) {
2609    return ERR_VAL;
2610  }
2611
2612  /* Set priority */
2613  altcp_setprio(pcb, HTTPD_TCP_PRIO);
2614
2615  /* Allocate memory for the structure that holds the state of the
2616     connection - initialized by that function. */
2617  hs = http_state_alloc();
2618  if (hs == NULL) {
2619    LWIP_DEBUGF(HTTPD_DEBUG, ("http_accept: Out of memory, RST\n"));
2620    return ERR_MEM;
2621  }
2622  hs->pcb = pcb;
2623
2624  /* Tell TCP that this is the structure we wish to be passed for our
2625     callbacks. */
2626  altcp_arg(pcb, hs);
2627
2628  /* Set up the various callback functions */
2629  altcp_recv(pcb, http_recv);
2630  altcp_err(pcb, http_err);
2631  altcp_poll(pcb, http_poll, HTTPD_POLL_INTERVAL);
2632  altcp_sent(pcb, http_sent);
2633
2634  return ERR_OK;
2635}
2636
2637static void
2638httpd_init_pcb(struct altcp_pcb *pcb, u16_t port)
2639{
2640  err_t err;
2641
2642  if (pcb) {
2643    altcp_setprio(pcb, HTTPD_TCP_PRIO);
2644    /* set SOF_REUSEADDR here to explicitly bind httpd to multiple interfaces */
2645    err = altcp_bind(pcb, IP_ANY_TYPE, port);
2646    LWIP_UNUSED_ARG(err); /* in case of LWIP_NOASSERT */
2647    LWIP_ASSERT("httpd_init: tcp_bind failed", err == ERR_OK);
2648    pcb = altcp_listen(pcb);
2649    LWIP_ASSERT("httpd_init: tcp_listen failed", pcb != NULL);
2650    altcp_accept(pcb, http_accept);
2651  }
2652}
2653
2654/**
2655 * @ingroup httpd
2656 * Initialize the httpd: set up a listening PCB and bind it to the defined port
2657 */
2658void
2659httpd_init(void)
2660{
2661  struct altcp_pcb *pcb;
2662
2663#if HTTPD_USE_MEM_POOL
2664  LWIP_MEMPOOL_INIT(HTTPD_STATE);
2665#if LWIP_HTTPD_SSI
2666  LWIP_MEMPOOL_INIT(HTTPD_SSI_STATE);
2667#endif
2668#endif
2669  LWIP_DEBUGF(HTTPD_DEBUG, ("httpd_init\n"));
2670
2671  /* LWIP_ASSERT_CORE_LOCKED(); is checked by tcp_new() */
2672
2673  pcb = altcp_tcp_new_ip_type(IPADDR_TYPE_ANY);
2674  LWIP_ASSERT("httpd_init: tcp_new failed", pcb != NULL);
2675  httpd_init_pcb(pcb, HTTPD_SERVER_PORT);
2676}
2677
2678#if HTTPD_ENABLE_HTTPS
2679/**
2680 * @ingroup httpd
2681 * Initialize the httpd: set up a listening PCB and bind it to the defined port.
2682 * Also set up TLS connection handling (HTTPS).
2683 */
2684void
2685httpd_inits(struct altcp_tls_config *conf)
2686{
2687#if LWIP_ALTCP_TLS
2688  struct altcp_pcb *pcb_tls = altcp_tls_new(conf, IPADDR_TYPE_ANY);
2689  LWIP_ASSERT("httpd_init: altcp_tls_new failed", pcb_tls != NULL);
2690  httpd_init_pcb(pcb_tls, HTTPD_SERVER_PORT_HTTPS);
2691#else /* LWIP_ALTCP_TLS */
2692  LWIP_UNUSED_ARG(conf);
2693#endif /* LWIP_ALTCP_TLS */
2694}
2695#endif /* HTTPD_ENABLE_HTTPS */
2696
2697#if LWIP_HTTPD_SSI
2698/**
2699 * @ingroup httpd
2700 * Set the SSI handler function.
2701 *
2702 * @param ssi_handler the SSI handler function
2703 * @param tags an array of SSI tag strings to search for in SSI-enabled files
2704 * @param num_tags number of tags in the 'tags' array
2705 */
2706void
2707http_set_ssi_handler(tSSIHandler ssi_handler, const char **tags, int num_tags)
2708{
2709  LWIP_DEBUGF(HTTPD_DEBUG, ("http_set_ssi_handler\n"));
2710
2711  LWIP_ASSERT("no ssi_handler given", ssi_handler != NULL);
2712  httpd_ssi_handler = ssi_handler;
2713
2714#if LWIP_HTTPD_SSI_RAW
2715  LWIP_UNUSED_ARG(tags);
2716  LWIP_UNUSED_ARG(num_tags);
2717#else /* LWIP_HTTPD_SSI_RAW */
2718  LWIP_ASSERT("no tags given", tags != NULL);
2719  LWIP_ASSERT("invalid number of tags", num_tags > 0);
2720
2721  httpd_tags = tags;
2722  httpd_num_tags = num_tags;
2723#endif /* !LWIP_HTTPD_SSI_RAW */
2724}
2725#endif /* LWIP_HTTPD_SSI */
2726
2727#if LWIP_HTTPD_CGI
2728/**
2729 * @ingroup httpd
2730 * Set an array of CGI filenames/handler functions
2731 *
2732 * @param cgis an array of CGI filenames/handler functions
2733 * @param num_handlers number of elements in the 'cgis' array
2734 */
2735void
2736http_set_cgi_handlers(const tCGI *cgis, int num_handlers)
2737{
2738  LWIP_ASSERT("no cgis given", cgis != NULL);
2739  LWIP_ASSERT("invalid number of handlers", num_handlers > 0);
2740
2741  httpd_cgis = cgis;
2742  httpd_num_cgis = num_handlers;
2743}
2744#endif /* LWIP_HTTPD_CGI */
2745
2746#endif /* LWIP_TCP && LWIP_CALLBACK_API */
2747