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
  27 struct per_session_data__post_demo {
  28         struct lws_spa *spa;
  29         char result[LWS_PRE + 500];
  30         int result_len;
  31
  32         char filename[256];
  33         long file_length;
  34         int fd;
  35 };
  36
  37 static const char * const param_names[] = {
  38         "text",
  39         "send",
  40         "file",
  41         "upload",
  42 };
  43
  44 enum enum_param_names {
  45         EPN_TEXT,
  46         EPN_SEND,
  47         EPN_FILE,
  48         EPN_UPLOAD,
  49 };
  50
  51 static int
  52 file_upload_cb(void *data, const char *name, const char *filename,
  53                char *buf, int len, enum lws_spa_fileupload_states state)
  54 {
  55         struct per_session_data__post_demo *pss =
  56                         (struct per_session_data__post_demo *)data;
  57         int n;
  58
  59         switch (state) {
  60         case LWS_UFS_OPEN:
  61                 strncpy(pss->filename, filename, sizeof(pss->filename) - 1);
  62                 /* we get the original filename in @filename arg, but for
  63                  * simple demo use a fixed name so we don't have to deal with
  64                  * attacks  */
  65                 pss->fd = open("/tmp/post-file",
  66                                O_CREAT | O_TRUNC | O_RDWR, 0600);
  67                 break;
  68         case LWS_UFS_FINAL_CONTENT:
  69         case LWS_UFS_CONTENT:
  70                 if (len) {
  71                         pss->file_length += len;
  72
  73                         /* if the file length is too big, drop it */
  74                         if (pss->file_length > 100000)
  75                                 return 1;
  76
  77                         n = write(pss->fd, buf, len);
  78                         lwsl_notice("%s: write %d says %d\n", __func__, len, n);
  79                 }
  80                 if (state == LWS_UFS_CONTENT)
  81                         break;
  82                 close(pss->fd);
  83                 pss->fd = LWS_INVALID_FILE;
  84                 break;
  85         }
  86
  87         return 0;
  88 }
  89
  90 static int
  91 callback_post_demo(struct lws *wsi, enum lws_callback_reasons reason,
  92                    void *user, void *in, size_t len)
  93 {
  94         struct per_session_data__post_demo *pss =
  95                         (struct per_session_data__post_demo *)user;
  96         unsigned char buffer[LWS_PRE + 512];
  97         unsigned char *p, *start, *end;
  98         int n;
  99
 100         switch (reason) {
 101         case LWS_CALLBACK_HTTP_BODY:
 102                 /* create the POST argument parser if not already existing */
 103                 if (!pss->spa) {
 104                         pss->spa = lws_spa_create(wsi, param_names,
 105                                         ARRAY_SIZE(param_names), 1024,
 106                                         file_upload_cb, pss);
 107                         if (!pss->spa)
 108                                 return -1;
 109
 110                         pss->filename[0] = '\0';
 111                         pss->file_length = 0;
 112                 }
 113
 114                 /* let it parse the POST data */
 115                 if (lws_spa_process(pss->spa, in, len))
 116                         return -1;
 117                 break;
 118
 119         case LWS_CALLBACK_HTTP_BODY_COMPLETION:
 120                 lwsl_debug("LWS_CALLBACK_HTTP_BODY_COMPLETION\n");
 121                 /* call to inform no more payload data coming */
 122                 lws_spa_finalize(pss->spa);
 123
 124                 p = (unsigned char *)pss->result + LWS_PRE;
 125                 end = p + sizeof(pss->result) - LWS_PRE - 1;
 126                 p += sprintf((char *)p,
 127                         "<html><body><h1>Form results (after urldecoding)</h1>"
 128                         "<table><tr><td>Name</td><td>Length</td><td>Value</td></tr>");
 129
 130                 for (n = 0; n < ARRAY_SIZE(param_names); n++)
 131                         p += snprintf((char *)p, end - p,
 132                                     "<tr><td><b>%s</b></td><td>%d</td><td>%s</td></tr>",
 133                                     param_names[n],
 134                                     lws_spa_get_length(pss->spa, n),
 135                                     lws_spa_get_string(pss->spa, n));
 136
 137                 p += snprintf((char *)p, end - p, "</table><br><b>filename:</b> %s, <b>length</b> %ld",
 138                                 pss->filename, pss->file_length);
 139
 140                 p += snprintf((char *)p, end - p, "</body></html>");
 141                 pss->result_len = p - (unsigned char *)(pss->result + LWS_PRE);
 142
 143                 p = buffer + LWS_PRE;
 144                 start = p;
 145                 end = p + sizeof(buffer) - LWS_PRE;
 146
 147                 if (lws_add_http_header_status(wsi, 200, &p, end))
 148                         return 1;
 149
 150                 if (lws_add_http_header_by_token(wsi, WSI_TOKEN_HTTP_CONTENT_TYPE,
 151                                 (unsigned char *)"text/html", 9, &p, end))
 152                         return 1;
 153                 if (lws_add_http_header_content_length(wsi, pss->result_len, &p, end))
 154                         return 1;
 155                 if (lws_finalize_http_header(wsi, &p, end))
 156                         return 1;
 157
 158                 n = lws_write(wsi, start, p - start, LWS_WRITE_HTTP_HEADERS);
 159                 if (n < 0)
 160                         return 1;
 161
 162                 lws_callback_on_writable(wsi);
 163                 break;
 164
 165         case LWS_CALLBACK_HTTP_WRITEABLE:
 166                 lwsl_debug("LWS_CALLBACK_HTTP_WRITEABLE: sending %d\n",
 167                            pss->result_len);
 168                 n = lws_write(wsi, (unsigned char *)pss->result + LWS_PRE,
 169                               pss->result_len, LWS_WRITE_HTTP);
 170                 if (n < 0)
 171                         return 1;
 172                 goto try_to_reuse;
 173
 174         case LWS_CALLBACK_HTTP_DROP_PROTOCOL:
 175                 /* called when our wsi user_space is going to be destroyed */
 176                 if (pss->spa) {
 177                         lws_spa_destroy(pss->spa);
 178                         pss->spa = NULL;
 179                 }
 180                 break;
 181
 182         default:
 183                 break;
 184         }
 185
 186         return 0;
 187
 188 try_to_reuse:
 189         if (lws_http_transaction_completed(wsi))
 190                 return -1;
 191
 192         return 0;
 193 }
 194
 195 static const struct lws_protocols protocols[] = {
 196         {
 197                 "protocol-post-demo",
 198                 callback_post_demo,
 199                 sizeof(struct per_session_data__post_demo),
 200                 1024,
 201         },
 202 };
 203
 204 LWS_EXTERN LWS_VISIBLE int
 205 init_protocol_post_demo(struct lws_context *context,
 206                         struct lws_plugin_capability *c)
 207 {
 208         if (c->api_magic != LWS_PLUGIN_API_MAGIC) {
 209                 lwsl_err("Plugin API %d, library API %d", LWS_PLUGIN_API_MAGIC,
 210                          c->api_magic);
 211                 return 1;
 212         }
 213
 214         c->protocols = protocols;
 215         c->count_protocols = ARRAY_SIZE(protocols);
 216         c->extensions = NULL;
 217         c->count_extensions = 0;
 218
 219         return 0;
 220 }
 221
 222 LWS_EXTERN LWS_VISIBLE int
 223 destroy_protocol_post_demo(struct lws_context *context)
 224 {
 225         return 0;
 226 }