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         char post_string[256];
  29         char result[500 + LWS_PRE];
  30         int result_len;
  31 };
  32
  33 static int
  34 callback_post_demo(struct lws *wsi, enum lws_callback_reasons reason,
  35                    void *user, void *in, size_t len)
  36 {
  37         struct per_session_data__post_demo *pss =
  38                         (struct per_session_data__post_demo *)user;
  39         unsigned char buffer[LWS_PRE + 512];
  40         unsigned char *p, *start, *end;
  41         int n;
  42
  43         switch (reason) {
  44
  45         case LWS_CALLBACK_HTTP_BODY:
  46                 lwsl_debug("LWS_CALLBACK_HTTP_BODY: len %d\n", (int)len);
  47                 strncpy(pss->post_string, in, sizeof (pss->post_string) -1);
  48                 pss->post_string[sizeof(pss->post_string) - 1] = '\0';
  49
  50                 if (len < sizeof(pss->post_string) - 1)
  51                         pss->post_string[len] = '\0';
  52                 break;
  53
  54         case LWS_CALLBACK_HTTP_WRITEABLE:
  55                 lwsl_debug("LWS_CALLBACK_HTTP_WRITEABLE: sending %d\n", pss->result_len);
  56                 n = lws_write(wsi, (unsigned char *)pss->result + LWS_PRE,
  57                               pss->result_len, LWS_WRITE_HTTP);
  58                 if (n < 0)
  59                         return 1;
  60                 goto try_to_reuse;
  61
  62         case LWS_CALLBACK_HTTP_BODY_COMPLETION:
  63                 lwsl_debug("LWS_CALLBACK_HTTP_BODY_COMPLETION\n");
  64                 /*
  65                  * the whole of the sent body arrived,
  66                  * respond to the client with a redirect to show the
  67                  * results
  68                  */
  69                 pss->result_len = sprintf((char *)pss->result + LWS_PRE,
  70                             "<html><body><h1>Form results</h1>'%s'<br>"
  71                             "</body></html>", pss->post_string);
  72
  73                 p = buffer + LWS_PRE;
  74                 start = p;
  75                 end = p + sizeof(buffer) - LWS_PRE;
  76
  77                 if (lws_add_http_header_status(wsi, 200, &p, end))
  78                         return 1;
  79
  80                 if (lws_add_http_header_by_token(wsi, WSI_TOKEN_HTTP_CONTENT_TYPE,
  81                                 (unsigned char *)"text/html", 9, &p, end))
  82                         return 1;
  83                 if (lws_add_http_header_content_length(wsi, pss->result_len, &p, end))
  84                         return 1;
  85                 if (lws_finalize_http_header(wsi, &p, end))
  86                         return 1;
  87
  88                 n = lws_write(wsi, start, p - start, LWS_WRITE_HTTP_HEADERS);
  89                 if (n < 0)
  90                         return 1;
  91
  92                 /*
  93                  *  send the payload next time, in case would block after
  94                  * headers
  95                  */
  96                 lws_callback_on_writable(wsi);
  97                 break;
  98
  99         default:
 100                 break;
 101         }
 102
 103         return 0;
 104
 105 try_to_reuse:
 106         if (lws_http_transaction_completed(wsi))
 107                 return -1;
 108
 109         return 0;
 110 }
 111
 112 static const struct lws_protocols protocols[] = {
 113         {
 114                 "protocol-post-demo",
 115                 callback_post_demo,
 116                 sizeof(struct per_session_data__post_demo),
 117                 1024,
 118         },
 119 };
 120
 121 LWS_EXTERN LWS_VISIBLE int
 122 init_protocol_post_demo(struct lws_context *context,
 123                         struct lws_plugin_capability *c)
 124 {
 125         if (c->api_magic != LWS_PLUGIN_API_MAGIC) {
 126                 lwsl_err("Plugin API %d, library API %d", LWS_PLUGIN_API_MAGIC,
 127                          c->api_magic);
 128                 return 1;
 129         }
 130
 131         c->protocols = protocols;
 132         c->count_protocols = ARRAY_SIZE(protocols);
 133         c->extensions = NULL;
 134         c->count_extensions = 0;
 135
 136         return 0;
 137 }
 138
 139 LWS_EXTERN LWS_VISIBLE int
 140 destroy_protocol_post_demo(struct lws_context *context)
 141 {
 142         return 0;
 143 }