plugins/protocol_post_demo.c

   1 /*
   2  * ws protocol handler plugin for "dumb increment"
   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         case LWS_CALLBACK_HTTP:
  41                 lwsl_debug("LWS_CALLBACK_HTTP\n");
  42                 if (lws_hdr_total_length(wsi, WSI_TOKEN_POST_URI))
  43                         return 0;
  44                 break;
  45
  46         case LWS_CALLBACK_HTTP_BODY:
  47                 lwsl_debug("LWS_CALLBACK_HTTP_BODY: len %d\n", (int)len);
  48                 strncpy(pss->post_string, in, sizeof (pss->post_string) -1);
  49                 pss->post_string[sizeof(pss->post_string) - 1] = '\0';
  50
  51                 if (len < sizeof(pss->post_string) - 1)
  52                         pss->post_string[len] = '\0';
  53                 break;
  54
  55         case LWS_CALLBACK_HTTP_WRITEABLE:
  56                 lwsl_debug("LWS_CALLBACK_HTTP_WRITEABLE: sending %d\n", pss->result_len);
  57                 n = lws_write(wsi, (unsigned char *)pss->result + LWS_PRE,
  58                               pss->result_len, LWS_WRITE_HTTP);
  59                 if (n < 0)
  60                         return 1;
  61                 goto try_to_reuse;
  62
  63         case LWS_CALLBACK_HTTP_BODY_COMPLETION:
  64                 lwsl_debug("LWS_CALLBACK_HTTP_BODY_COMPLETION\n");
  65                 /*
  66                  * the whole of the sent body arrived,
  67                  * respond to the client with a redirect to show the
  68                  * results
  69                  */
  70                 pss->result_len = sprintf((char *)pss->result + LWS_PRE,
  71                             "<html><body><h1>Form results</h1>'%s'<br>"
  72                             "</body></html>", pss->post_string);
  73
  74                 p = buffer + LWS_PRE;
  75                 start = p;
  76                 end = p + sizeof(buffer) - LWS_PRE;
  77
  78                 if (lws_add_http_header_status(wsi, 200, &p, end))
  79                         return 1;
  80
  81                 if (lws_add_http_header_by_token(wsi, WSI_TOKEN_HTTP_CONTENT_TYPE,
  82                                 (unsigned char *)"text/html", 9, &p, end))
  83                         return 1;
  84                 if (lws_add_http_header_content_length(wsi, pss->result_len, &p, end))
  85                         return 1;
  86                 if (lws_finalize_http_header(wsi, &p, end))
  87                         return 1;
  88
  89                 n = lws_write(wsi, start, p - start, LWS_WRITE_HTTP_HEADERS);
  90                 if (n < 0)
  91                         return 1;
  92
  93                 /*
  94                  *  send the payload next time, in case would block after
  95                  * headers
  96                  */
  97                 lws_callback_on_writable(wsi);
  98                 break;
  99
 100         default:
 101                 break;
 102         }
 103
 104         return 0;
 105
 106 try_to_reuse:
 107         if (lws_http_transaction_completed(wsi))
 108                 return -1;
 109
 110         return 0;
 111 }
 112
 113 static const struct lws_protocols protocols[] = {
 114         {
 115                 "protocol-post-demo",
 116                 callback_post_demo,
 117                 sizeof(struct per_session_data__post_demo),
 118                 1024,
 119         },
 120 };
 121
 122 LWS_VISIBLE int
 123 init_protocol_post_demo(struct lws_context *context,
 124                         struct lws_plugin_capability *c)
 125 {
 126         if (c->api_magic != LWS_PLUGIN_API_MAGIC) {
 127                 lwsl_err("Plugin API %d, library API %d", LWS_PLUGIN_API_MAGIC,
 128                          c->api_magic);
 129                 return 1;
 130         }
 131
 132         c->protocols = protocols;
 133         c->count_protocols = ARRAY_SIZE(protocols);
 134         c->extensions = NULL;
 135         c->count_extensions = 0;
 136
 137         return 0;
 138 }
 139
 140 LWS_VISIBLE int
 141 destroy_protocol_post_demo(struct lws_context *context)
 142 {
 143         return 0;
 144 }