minimal-examples/http-server/minimal-http-server-form-get/minimal-http-server-form-get.c

   1 /*
   2  * lws-minimal-http-server-form-get
   3  *
   4  * Written in 2010-2019 by 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  * This demonstrates a minimal http server that performs a form GET with a couple
  10  * of parameters.  It dumps the parameters to the console log and redirects
  11  * to another page.
  12  */
  13
  14 #include <libwebsockets.h>
  15 #include <string.h>
  16 #include <signal.h>
  17
  18 static int interrupted;
  19
  20 static const char * param_names[] = {
  21         "text1",
  22         "send"
  23 };
  24
  25 static int
  26 callback_http(struct lws *wsi, enum lws_callback_reasons reason, void *user,
  27               void *in, size_t len)
  28 {
  29         uint8_t buf[LWS_PRE + LWS_RECOMMENDED_MIN_HEADER_SPACE],
  30                 *start = &buf[LWS_PRE], *p = start,
  31                 *end = &buf[sizeof(buf) - 1];
  32         const char *val;
  33         int n;
  34
  35         switch (reason) {
  36         case LWS_CALLBACK_HTTP:
  37
  38                 if (!lws_hdr_total_length(wsi, WSI_TOKEN_GET_URI))
  39                         /* not a GET */
  40                         break;
  41                 lwsl_err("%s: %s\n", __func__, (const char *)in);
  42                 if (strcmp((const char *)in, "/form1"))
  43                         /* not our form URL */
  44                         break;
  45
  46                 /* we just dump the decoded things to the log */
  47
  48                 for (n = 0; n < (int)LWS_ARRAY_SIZE(param_names); n++) {
  49                         val = lws_get_urlarg_by_name(wsi, param_names[n],
  50                                         (char *)buf, sizeof(buf));
  51                         if (!val)
  52                                 lwsl_user("%s: undefined\n", param_names[n]);
  53                         else
  54                                 lwsl_user("%s: (len %d) '%s'\n", param_names[n],
  55                                           (int)strlen((const char *)buf),buf);
  56                 }
  57
  58                 /*
  59                  * Our response is to redirect to a static page.  We could
  60                  * have generated a dynamic html page here instead.
  61                  */
  62
  63                 if (lws_http_redirect(wsi, HTTP_STATUS_MOVED_PERMANENTLY,
  64                                       (unsigned char *)"after-form1.html",
  65                                       16, &p, end) < 0)
  66                         return -1;
  67                 break;
  68
  69         default:
  70                 break;
  71         }
  72
  73         return lws_callback_http_dummy(wsi, reason, user, in, len);
  74 }
  75
  76 static struct lws_protocols protocols[] = {
  77         { "http", callback_http, 0, 0 },
  78         { NULL, NULL, 0, 0 } /* terminator */
  79 };
  80
  81 /* default mount serves the URL space from ./mount-origin */
  82
  83 static const struct lws_http_mount mount = {
  84         /* .mount_next */              NULL,            /* linked-list "next" */
  85         /* .mountpoint */               "/",            /* mountpoint URL */
  86         /* .origin */           "./mount-origin",       /* serve from dir */
  87         /* .def */                      "index.html",   /* default filename */
  88         /* .protocol */                 NULL,
  89         /* .cgienv */                   NULL,
  90         /* .extra_mimetypes */          NULL,
  91         /* .interpret */                NULL,
  92         /* .cgi_timeout */              0,
  93         /* .cache_max_age */            0,
  94         /* .auth_mask */                0,
  95         /* .cache_reusable */           0,
  96         /* .cache_revalidate */         0,
  97         /* .cache_intermediaries */     0,
  98         /* .origin_protocol */          LWSMPRO_FILE,   /* files in a dir */
  99         /* .mountpoint_len */           1,              /* char count */
 100         /* .basic_auth_login_file */    NULL,
 101 };
 102
 103 void sigint_handler(int sig)
 104 {
 105         interrupted = 1;
 106 }
 107
 108 int main(int argc, const char **argv)
 109 {
 110         struct lws_context_creation_info info;
 111         struct lws_context *context;
 112         const char *p;
 113         int n = 0, logs = LLL_USER | LLL_ERR | LLL_WARN | LLL_NOTICE
 114                         /* for LLL_ verbosity above NOTICE to be built into lws,
 115                          * lws must have been configured and built with
 116                          * -DCMAKE_BUILD_TYPE=DEBUG instead of =RELEASE */
 117                         /* | LLL_INFO */ /* | LLL_PARSER */ /* | LLL_HEADER */
 118                         /* | LLL_EXT */ /* | LLL_CLIENT */ /* | LLL_LATENCY */
 119                         /* | LLL_DEBUG */;
 120
 121         signal(SIGINT, sigint_handler);
 122
 123         if ((p = lws_cmdline_option(argc, argv, "-d")))
 124                 logs = atoi(p);
 125
 126         lws_set_log_level(logs, NULL);
 127         lwsl_user("LWS minimal http server GET | visit http://localhost:7681\n");
 128
 129         memset(&info, 0, sizeof info); /* otherwise uninitialized garbage */
 130         info.port = 7681;
 131         info.protocols = protocols;
 132         info.mounts = &mount;
 133         info.options =
 134                 LWS_SERVER_OPTION_HTTP_HEADERS_SECURITY_BEST_PRACTICES_ENFORCE;
 135
 136         context = lws_create_context(&info);
 137         if (!context) {
 138                 lwsl_err("lws init failed\n");
 139                 return 1;
 140         }
 141
 142         while (n >= 0 && !interrupted)
 143                 n = lws_service(context, 0);
 144
 145         lws_context_destroy(context);
 146
 147         return 0;
 148 }