int main(int argc, char *argv[])
{
char header[] = "Powered-by: ANSI C scripts\r\n";
http_header(HEAD_ADD, header, sizeof(header) - 1, argv);
xbuf_cat(get_reply(argv), "Look at the HTTP headers");
return 200; // return an HTTP code (200:'OK')
}
void flush(void)
{
// TODO: flush() can later return some info about the flushed data, e.g. size
if (!this->headersSet)
{
this->flushHeaders();
}
xbuf_cat(this->httpOut, (char *) this->payload.c_str());
u32toa(this->httpOut->ptr + this->ptrHeaderSize, this->httpOut->len - this->headersSize);
}
int main(int argc, char *argv[])
{
xbuf_t data;
xbuf_init(&data);
xbuf_cat(&data,
"Lorem ipsum dolor sit amet, consectetur adipiscing elit. Morbi sit amet "
"quam purus, vitae fermentum turpis. Nam in augue mi. Donec suscipit moles"
"tie felis, eget rhoncus risus pharetra in. Sed id diam id felis fringilla"
" adipiscing non vitae odio. Etiam vulputate tristique elit, nec eleifend"
" mauris scelerisque eu. Vestibulum luctus, enim a luctus posuere, mauris"
" mauris rutrum mi, eget fermentum massa tortor id enim. Nulla feugiat "
"porta urna quis laoreet. Morbi metus ante, commodo quis dictum vitae, "
"rhoncus a libero. Cras viverra feugiat orci id interdum. Duis pulvinar "
"neque id erat adipiscing facilisis. Maecenas vitae urna risus, euismod"
" sollicitudin risus."
);
char gzipped[4096];
u32 len = zlib_cmp(data.ptr, 0, data.len, gzipped, sizeof(gzipped), 1);
printf("Original length: %i\n", data.len);
printf("Gzipped length: %i\n\n", len);
xbuf_t *reply = get_reply(argv);
xbuf_xcat(reply,
"HTTP/1.1 200 OK\r\n"
"Content-Type: text/plain\r\n"
"Content-Length: %i\r\n"
"Content-Encoding: gzip\r\n\r\n",
len
);
xbuf_ncat(reply, gzipped, len);
xbuf_free(&data);
return -1; //custom headers
}
int main(int argc, char *argv[])
{
//initialize Key-Value store--------------------------------------------------
kv_t **vhost_ptr = (kv_t**)get_env(argv, US_VHOST_DATA), //persistent ptr
*forum_store = 0; //convenience pointer (var->m instead of (*var)->m)
if (vhost_ptr && !*vhost_ptr)
{
*vhost_ptr = (kv_t*)malloc(sizeof(kv_t));
//threads and posts stored here
kv_init(*vhost_ptr, "forum_store", 1024, 0, 0, 0);
} forum_store = *vhost_ptr;
//----------------------------------------------------------------------------
//setup GET and POST variables------------------------------------------------
char *act = "", *id = "", *title = "", *body = "";
get_arg("act=", &act, argc, argv); //action ('t' or 'p')
get_arg("id=", &id, argc, argv); //id of thread
get_arg("title=", &title, argc, argv); //title of thread
get_arg("body=", &body, argc, argv); //body of post
char *end = 0;
u64 int_id = strtoll(id, &end, 10); //string to integer
if (*end) int_id = 0; //require a numeric ID
//----------------------------------------------------------------------------
//response sent to browser is stored here-------------------------------------
//templates are rendered into this buffer
xbuf_t *reply = get_reply(argv);
xbuf_cat(reply, base_tpl); //set base template
//----------------------------------------------------------------------------
//HTTP state of a connection
http_t *http = (http_t*)get_env(argv, HTTP_HEADERS);
redirect: //simulate HTTP, <meta>, or JavaScript redirect without page reload
//choose what to do based on the value of 'act'-------------------------------
switch (*act)
{
//regarding a post
case 'p':
{
switch (http->h_method) //GET or POST
{
//new post--------------------------------------------------------------
case HTTP_POST:
{
//get the thread to which this post belongs
Thread *thread = (Thread*)kv_get(forum_store, (char*)&int_id, sizeof(int_id));
if (!thread) //thread not found
{
xbuf_repl(reply, "<!--tpl-->", http_error(404));
return 404;
}
//allocate memory
Post *post = calloc(1, sizeof(*post));
//initialize members
xbuf_init(&post->body);
//define members
post->id = thread->posts.nbr_items + 1;
xbuf_cat(&post->body, *body ? body : " ");
//add post to thread
kv_add(&thread->posts, &(kv_item) {
.key = (char*)&post->id,
.klen = sizeof(post->id),
.val = (char*)post,
.flags = 0,
});
//setup redirect
http->h_method = HTTP_GET;
*act = 't';
goto redirect;
} break;
//----------------------------------------------------------------------
}
} break;
//regarding a thread
case 't':
{
switch (http->h_method)
{
//view a thread---------------------------------------------------------
case HTTP_GET:
{
Thread *thread = (Thread*)kv_get(forum_store, (char*)&int_id, sizeof(int_id));
if (!thread)
{
xbuf_repl(reply, "<!--tpl-->", http_error(404));
return 404;
}
//replace template variables with dynamic values
xbuf_repl(reply, "<!--form-->", post_form);
xbuf_repl(reply, "<!--title-->", thread->title.ptr);
xbuf_repl(reply, "<!--id-->", id);
//for each post, render its template and insert it into reply
kv_do(&thread->posts, 0, 0, (kv_proc_t)&list_posts, (void*)reply);
} break;
//----------------------------------------------------------------------
//create a thread-------------------------------------------------------
case HTTP_POST:
{
Thread *thread = calloc(1, sizeof(*thread));
xbuf_init(&thread->title);
kv_init(&thread->posts, "posts", 1024, 0, 0, 0);
thread->id = forum_store->nbr_items + 1;
xbuf_cat(&thread->title, *title ? title : " ");
//add thread to KV store
kv_add(forum_store, &(kv_item) {
.key = (char*)&thread->id,
.klen = sizeof(thread->id),
.val = (char*)thread,
.flags = 0,
});
http->h_method = HTTP_GET;
*act = 0;
goto redirect;
} break;
//----------------------------------------------------------------------
}
} break;
// ----------------------------------------------------------------------------
// imported functions:
// get_reply(): get a pointer on the 'reply' dynamic buffer from the server
// get_env(): get connection's 'environment' variables from the server
// xbuf_cat(): like strcat(), but it works in the specified dynamic buffer
// gif_build(): build an in-memory GIF image from a bitmap and palette
// ----------------------------------------------------------------------------
int main(int argc, char *argv[])
{
// -------------------------------------------------------------------------
// build the top of our HTML page
// -------------------------------------------------------------------------
static char top[]=
"<!DOCTYPE HTML>"
"<html lang=\"en\"><head><title>Captcha</title><meta http-equiv"
"=\"Content-Type\" content=\"text/html; charset=utf-8\">"
"<link href=\"/imgs/style.css\" rel=\"stylesheet\" type=\"text/css\">"
"</head><body style=\"margin:0 16px;\"><br><h2>Captcha for Humans</h2>"
"<p>Please enter the SUM of all the GREEN FIGURES (not letters) below "
"(that's twice the same image, just with a different HTML background "
"- the Data-URI-inlined GIF background is transparent):</p><br>\r\n";
xbuf_t *reply = get_reply(argv);
xbuf_ncat(reply, top, sizeof(top) - 1);
// -------------------------------------------------------------------------
// allocate memory for a raw bitmap
// -------------------------------------------------------------------------
const int w = BMP_WIDTH, h = BMP_HEIGHT, wXh = w * h;
u8 *bmp = (u8*)calloc(CHAR_WIDTH * w, h);
if(!bmp) return 503; // service unavailable
// -------------------------------------------------------------------------
// render the captcha in our bitmap
// -------------------------------------------------------------------------
u32 seed = (u32)getns();
prnd_t rnd; // pseudo-random generator (period: 1 << 158)
sw_init(&rnd, seed); // EPOCH time in nano-seconds
// structure needed by G-WAN's frame buffer routines like dr_text()
bmp_t img ={ .bmp = bmp, .p = bmp, .bbp = 8, .pen = 1, .bgd = 0,
.rect = {0,0, w,h}, .flags = 0, .w = w, .h = h,
.x = 0, .y = 0 };
u32 sum = captcha(&img, &rnd);
// -------------------------------------------------------------------------
// build the GIF image, gif_build(0:transparent color index, 0: no comment)
// -------------------------------------------------------------------------
u8 pal[] = { 255, 255, 255, 223, 255, 191, 132, 164, 100, 0, 0, 0 };
const int nbcolors = (sizeof(pal) / sizeof(u8)) / 3; // RGB values
u8 *gif = (u8*)malloc(CHAR_WIDTH * wXh);
if(!gif) { free(bmp); return 503; } // service unavailable
int gln = gif_build(gif, bmp, w, h, pal, nbcolors, 0, 0);
// -------------------------------------------------------------------------
// store the base64 encoded GIF in the 'reply' buffer
// -------------------------------------------------------------------------
if(gln > 0) // (gln == -1) if gif_build() failed
{
// a real captcha test would only display the first of those two views:
// (they are shown side-by-side to visualize the background trick)
xbuf_cat(reply, "<table><tr>\r\n"
"<td style=\"background:#dfffbf;\">\r\n");
u32 img_pos = reply->len;
xbuf_xcat(reply,
"<img src=\"data:image/gif;base64,%*B\" alt=\"A tree\" "
"width=\"%d\" height=\"%d\" /></td>\r\n",
gln, gif, w + w, h + h); // scale picture
xbuf_xcat(reply,
"<td style=\"background:#84a464;\">%.*s</tr>\r\n</table>\n\r",
reply->len - img_pos, reply->ptr + img_pos);
}
free(gif);
free(bmp);
// -------------------------------------------------------------------------
// close our HTML page
// -------------------------------------------------------------------------
xbuf_xcat(reply,
"<br>The two sums are: <b>%u</b> and <b>%u</b>... "
"for the same Captcha image!<br><br>"
"By just changing the <b>HTML background color</b> (mouse cursor "
"hovering, previous state or input or shared secret) used for "
"the transparent GIF Captcha image we can make something simple "
"for humans become difficult or even completely impossible "
"for robots.<br><br>"
"HTML and GIF are served with one single request: the picture"
" is generated on-the-fly and embedded into the HTML code by "
" using the base64 encoding (look at the HTML source code)."
"<br></body></html>",
(sum & 0xffff0000) >> 16,
sum & 0x0000ffff);
return 200; // return an HTTP code (200:'OK')
}
