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 #include "../lib/libwebsockets.h"
  21 #include <string.h>
  22
  23 struct per_session_data__post_demo {
  24         char post_string[256];
  25         char result[500 + LWS_PRE];
  26         int result_len;
  27 };
  28
  29 static int
  30 callback_post_demo(struct lws *wsi, enum lws_callback_reasons reason,
  31                    void *user, void *in, size_t len)
  32 {
  33         struct per_session_data__post_demo *pss =
  34                         (struct per_session_data__post_demo *)user;
  35         unsigned char buffer[LWS_PRE + 512];
  36         unsigned char *p, *start, *end;
  37         int n;
  38
  39         switch (reason) {
  40
  41         case LWS_CALLBACK_HTTP_BODY:
  42                 lwsl_debug("LWS_CALLBACK_HTTP_BODY: len %d\n", (int)len);
  43                 strncpy(pss->post_string, in, sizeof (pss->post_string) -1);
  44                 pss->post_string[sizeof(pss->post_string) - 1] = '\0';
  45
  46                 if (len < sizeof(pss->post_string) - 1)
  47                         pss->post_string[len] = '\0';
  48                 break;
  49
  50         case LWS_CALLBACK_HTTP_WRITEABLE:
  51                 lwsl_debug("LWS_CALLBACK_HTTP_WRITEABLE: sending %d\n", pss->result_len);
  52                 n = lws_write(wsi, (unsigned char *)pss->result + LWS_PRE,
  53                               pss->result_len, LWS_WRITE_HTTP);
  54                 if (n < 0)
  55                         return 1;
  56                 goto try_to_reuse;
  57
  58         case LWS_CALLBACK_HTTP_BODY_COMPLETION:
  59                 lwsl_debug("LWS_CALLBACK_HTTP_BODY_COMPLETION\n");
  60                 /*
  61                  * the whole of the sent body arrived,
  62                  * respond to the client with a redirect to show the
  63                  * results
  64                  */
  65                 pss->result_len = sprintf((char *)pss->result + LWS_PRE,
  66                             "<html><body><h1>Form results</h1>'%s'<br>"
  67                             "</body></html>", pss->post_string);
  68
  69                 p = buffer + LWS_PRE;
  70                 start = p;
  71                 end = p + sizeof(buffer) - LWS_PRE;
  72
  73                 if (lws_add_http_header_status(wsi, 200, &p, end))
  74                         return 1;
  75
  76                 if (lws_add_http_header_by_token(wsi, WSI_TOKEN_HTTP_CONTENT_TYPE,
  77                                 (unsigned char *)"text/html", 9, &p, end))
  78                         return 1;
  79                 if (lws_add_http_header_content_length(wsi, pss->result_len, &p, end))
  80                         return 1;
  81                 if (lws_finalize_http_header(wsi, &p, end))
  82                         return 1;
  83
  84                 n = lws_write(wsi, start, p - start, LWS_WRITE_HTTP_HEADERS);
  85                 if (n < 0)
  86                         return 1;
  87
  88                 /*
  89                  *  send the payload next time, in case would block after
  90                  * headers
  91                  */
  92                 lws_callback_on_writable(wsi);
  93                 break;
  94
  95         default:
  96                 break;
  97         }
  98
  99         return 0;
 100
 101 try_to_reuse:
 102         if (lws_http_transaction_completed(wsi))
 103                 return -1;
 104
 105         return 0;
 106 }
 107
 108 static const struct lws_protocols protocols[] = {
 109         {
 110                 "protocol-post-demo",
 111                 callback_post_demo,
 112                 sizeof(struct per_session_data__post_demo),
 113                 1024,
 114         },
 115 };
 116
 117 LWS_VISIBLE int
 118 init_protocol_post_demo(struct lws_context *context,
 119                         struct lws_plugin_capability *c)
 120 {
 121         if (c->api_magic != LWS_PLUGIN_API_MAGIC) {
 122                 lwsl_err("Plugin API %d, library API %d", LWS_PLUGIN_API_MAGIC,
 123                          c->api_magic);
 124                 return 1;
 125         }
 126
 127         c->protocols = protocols;
 128         c->count_protocols = ARRAY_SIZE(protocols);
 129         c->extensions = NULL;
 130         c->count_extensions = 0;
 131
 132         return 0;
 133 }
 134
 135 LWS_VISIBLE int
 136 destroy_protocol_post_demo(struct lws_context *context)
 137 {
 138         return 0;
 139 }