plugins/protocol_post_demo.c

   1 /*
   2  * ws protocol handler plugin for "POST demo"
   3  *
   4  * Copyright (C) 2010-2016 Andy Green <andy@warmcat.com>
   5  *
   6  * This file is made available under the Creative Commons CC0 1.0
   7  * Universal Public Domain Dedication.
   8  *
   9  * The person who associated a work with this deed has dedicated
  10  * the work to the public domain by waiving all of his or her rights
  11  * to the work worldwide under copyright law, including all related
  12  * and neighboring rights, to the extent allowed by law. You can copy,
  13  * modify, distribute and perform the work, even for commercial purposes,
  14  * all without asking permission.
  15  *
  16  * These test plugins are intended to be adapted for use in your code, which
  17  * may be proprietary.  So unlike the library itself, they are licensed
  18  * Public Domain.
  19  */
  20
  21 #define LWS_DLL
  22 #define LWS_INTERNAL
  23 #include "../lib/libwebsockets.h"
  24
  25 #include <string.h>
  26 #include <fcntl.h>
  27 #include <sys/types.h>
  28 #include <sys/stat.h>
  29 #ifdef WIN32
  30 #include <io.h>
  31 #endif
  32 #include <stdio.h>
  33
  34 struct per_session_data__post_demo {
  35         struct lws_spa *spa;
  36         char result[LWS_PRE + 500];
  37         int result_len;
  38
  39         char filename[256];
  40         long file_length;
  41         lws_filefd_type fd;
  42 };
  43
  44 static const char * const param_names[] = {
  45         "text",
  46         "send",
  47         "file",
  48         "upload",
  49 };
  50
  51 enum enum_param_names {
  52         EPN_TEXT,
  53         EPN_SEND,
  54         EPN_FILE,
  55         EPN_UPLOAD,
  56 };
  57
  58 static int
  59 file_upload_cb(void *data, const char *name, const char *filename,
  60                char *buf, int len, enum lws_spa_fileupload_states state)
  61 {
  62         struct per_session_data__post_demo *pss =
  63                         (struct per_session_data__post_demo *)data;
  64         int n;
  65
  66         switch (state) {
  67         case LWS_UFS_OPEN:
  68                 strncpy(pss->filename, filename, sizeof(pss->filename) - 1);
  69                 /* we get the original filename in @filename arg, but for
  70                  * simple demo use a fixed name so we don't have to deal with
  71                  * attacks  */
  72                 pss->fd = open("/tmp/post-file",
  73                                O_CREAT | O_TRUNC | O_RDWR, 0600);
  74                 break;
  75         case LWS_UFS_FINAL_CONTENT:
  76         case LWS_UFS_CONTENT:
  77                 if (len) {
  78                         pss->file_length += len;
  79
  80                         /* if the file length is too big, drop it */
  81                         if (pss->file_length > 100000)
  82                                 return 1;
  83
  84                         n = write(pss->fd, buf, len);
  85                         lwsl_notice("%s: write %d says %d\n", __func__, len, n);
  86                 }
  87                 if (state == LWS_UFS_CONTENT)
  88                         break;
  89                 close(pss->fd);
  90                 pss->fd = LWS_INVALID_FILE;
  91                 break;
  92         }
  93
  94         return 0;
  95 }
  96
  97 static int
  98 callback_post_demo(struct lws *wsi, enum lws_callback_reasons reason,
  99                    void *user, void *in, size_t len)
 100 {
 101         struct per_session_data__post_demo *pss =
 102                         (struct per_session_data__post_demo *)user;
 103         unsigned char buffer[LWS_PRE + 512];
 104         unsigned char *p, *start, *end;
 105         int n;
 106
 107         switch (reason) {
 108         case LWS_CALLBACK_HTTP_BODY:
 109                 /* create the POST argument parser if not already existing */
 110                 if (!pss->spa) {
 111                         pss->spa = lws_spa_create(wsi, param_names,
 112                                         ARRAY_SIZE(param_names), 1024,
 113                                         file_upload_cb, pss);
 114                         if (!pss->spa)
 115                                 return -1;
 116
 117                         pss->filename[0] = '\0';
 118                         pss->file_length = 0;
 119                 }
 120
 121                 /* let it parse the POST data */
 122                 if (lws_spa_process(pss->spa, in, len))
 123                         return -1;
 124                 break;
 125
 126         case LWS_CALLBACK_HTTP_BODY_COMPLETION:
 127                 lwsl_debug("LWS_CALLBACK_HTTP_BODY_COMPLETION\n");
 128                 /* call to inform no more payload data coming */
 129                 lws_spa_finalize(pss->spa);
 130
 131                 p = (unsigned char *)pss->result + LWS_PRE;
 132                 end = p + sizeof(pss->result) - LWS_PRE - 1;
 133                 p += sprintf((char *)p,
 134                         "<html><body><h1>Form results (after urldecoding)</h1>"
 135                         "<table><tr><td>Name</td><td>Length</td><td>Value</td></tr>");
 136
 137                 for (n = 0; n < ARRAY_SIZE(param_names); n++)
 138                         p += snprintf((char *)p, end - p,
 139                                     "<tr><td><b>%s</b></td><td>%d</td><td>%s</td></tr>",
 140                                     param_names[n],
 141                                     lws_spa_get_length(pss->spa, n),
 142                                     lws_spa_get_string(pss->spa, n));
 143
 144                 p += snprintf((char *)p, end - p, "</table><br><b>filename:</b> %s, <b>length</b> %ld",
 145                                 pss->filename, pss->file_length);
 146
 147                 p += snprintf((char *)p, end - p, "</body></html>");
 148                 pss->result_len = p - (unsigned char *)(pss->result + LWS_PRE);
 149
 150                 p = buffer + LWS_PRE;
 151                 start = p;
 152                 end = p + sizeof(buffer) - LWS_PRE;
 153
 154                 if (lws_add_http_header_status(wsi, 200, &p, end))
 155                         return 1;
 156
 157                 if (lws_add_http_header_by_token(wsi, WSI_TOKEN_HTTP_CONTENT_TYPE,
 158                                 (unsigned char *)"text/html", 9, &p, end))
 159                         return 1;
 160                 if (lws_add_http_header_content_length(wsi, pss->result_len, &p, end))
 161                         return 1;
 162                 if (lws_finalize_http_header(wsi, &p, end))
 163                         return 1;
 164
 165                 n = lws_write(wsi, start, p - start, LWS_WRITE_HTTP_HEADERS);
 166                 if (n < 0)
 167                         return 1;
 168
 169                 lws_callback_on_writable(wsi);
 170                 break;
 171
 172         case LWS_CALLBACK_HTTP_WRITEABLE:
 173                 lwsl_debug("LWS_CALLBACK_HTTP_WRITEABLE: sending %d\n",
 174                            pss->result_len);
 175                 n = lws_write(wsi, (unsigned char *)pss->result + LWS_PRE,
 176                               pss->result_len, LWS_WRITE_HTTP);
 177                 if (n < 0)
 178                         return 1;
 179                 goto try_to_reuse;
 180
 181         case LWS_CALLBACK_HTTP_DROP_PROTOCOL:
 182                 /* called when our wsi user_space is going to be destroyed */
 183                 if (pss->spa) {
 184                         lws_spa_destroy(pss->spa);
 185                         pss->spa = NULL;
 186                 }
 187                 break;
 188
 189         default:
 190                 break;
 191         }
 192
 193         return 0;
 194
 195 try_to_reuse:
 196         if (lws_http_transaction_completed(wsi))
 197                 return -1;
 198
 199         return 0;
 200 }
 201
 202 static const struct lws_protocols protocols[] = {
 203         {
 204                 "protocol-post-demo",
 205                 callback_post_demo,
 206                 sizeof(struct per_session_data__post_demo),
 207                 1024,
 208         },
 209 };
 210
 211 LWS_EXTERN LWS_VISIBLE int
 212 init_protocol_post_demo(struct lws_context *context,
 213                         struct lws_plugin_capability *c)
 214 {
 215         if (c->api_magic != LWS_PLUGIN_API_MAGIC) {
 216                 lwsl_err("Plugin API %d, library API %d", LWS_PLUGIN_API_MAGIC,
 217                          c->api_magic);
 218                 return 1;
 219         }
 220
 221         c->protocols = protocols;
 222         c->count_protocols = ARRAY_SIZE(protocols);
 223         c->extensions = NULL;
 224         c->count_extensions = 0;
 225
 226         return 0;
 227 }
 228
 229 LWS_EXTERN LWS_VISIBLE int
 230 destroy_protocol_post_demo(struct lws_context *context)
 231 {
 232         return 0;
 233 }