+fn get_voter(request: &cgi::Request) -> Result<&[u8], cgi::Response> {
+ // Expect exactly one cookie, exactly as we generate it.
+ let cookie = request
+ .headers()
+ .get(cgi::http::header::COOKIE)
+ .map(cgi::http::HeaderValue::as_bytes)
+ .and_then(|c| c.strip_prefix(COOKIE_NAME))
+ .and_then(|c| c.strip_prefix(b"="))
+ .ok_or_else(|| cgi::text_response(400, "Invalid cookie"))?;
+ if cookie.len() != COOKIE_LENGTH || cookie.contains(&b' ') || cookie.contains(&b';') {
+ Err(cgi::text_response(400, "Invalid cookie"))
+ } else {
+ Ok(cookie)
+ }
+}
+
+fn tally_votes(dir: &Path) -> std::io::Result<HashMap<String, HashSet<String>>> {
+ let mut tally: HashMap<String, HashSet<String>> = HashMap::new();
+ match std::fs::File::open(dir.to_owned().join("votes")) {
+ Err(e) if e.kind() == std::io::ErrorKind::NotFound => Ok(tally),
+ Err(e) => Err(e),
+ Ok(vfile) => {
+ for liner in std::io::BufReader::new(vfile).lines() {
+ let line = liner?;
+ if let Some((voter, datum)) = line.split_once(' ') {
+ if voter.len() == COOKIE_LENGTH {
+ if let Some((vote, candidate)) = datum.split_once(' ') {
+ if vote == "0" {
+ if let Some(entry) = tally.get_mut(candidate) {
+ entry.remove(voter);
+ }
+ } else if vote == "1" {
+ tally
+ .entry(candidate.to_owned())
+ .or_default()
+ .insert(voter.to_owned());
+ }
+ }
+ }
+ }
+ }
+ Ok(tally)
+ }
+ }
+}
+
+fn read_elim_list(dir: &Path) -> std::io::Result<HashSet<String>> {
+ match std::fs::File::open(dir.join("eliminated")) {
+ Err(e) if e.kind() == std::io::ErrorKind::NotFound => Ok(HashSet::new()),
+ Err(e) => Err(e),
+ Ok(elimfile) => std::io::BufReader::new(elimfile).lines().collect(),
+ }
+}
+
+fn valid_id_char(c: u8) -> bool {
+ c.is_ascii_alphanumeric()
+}
+
+fn make_random_id() -> [u8; COOKIE_LENGTH] {
+ let mut id = [0; COOKIE_LENGTH];
+ for c in &mut id {
+ while !valid_id_char(*c) {
+ *c = random();
+ }
+ }
+ id
+}
+
+fn set_cookie(mut response: cgi::Response, path: &str) -> Result<cgi::Response, cgi::Response> {
+ response.headers_mut().append(
+ cgi::http::header::SET_COOKIE,
+ cgi::http::header::HeaderValue::from_bytes(
+ &[
+ COOKIE_NAME,
+ b"=",
+ &make_random_id(),
+ b"; Secure; HttpOnly; SameSite=Strict; Max-Age=30000000; Path=",
+ path.as_bytes(),
+ ]
+ .concat(),
+ )
+ .map_err(|_| cgi::text_response(503, "Couldn't make cookie"))?,
+ );
+ Ok(response)
+}
+
+const HTML_HEADER: &str = "<!DOCTYPE html>
+<html>
+ <head>
+ <meta charset=\"utf-8\">
+ <title>Vote!</title>
+ <style>
+ th { font-size: 70%; text-align: left }
+ input { transform: scale(1.5) }
+ .eliminated { text-decoration: line-through; }
+ div { animation: 2s infinite linear spin }
+ @keyframes spin {
+ from { transform:rotate(0) }
+ to { transform:rotate(1turn) }
+ }
+ </style>
+ <script>
+ window.onload = function() {
+ for (cb of document.getElementsByTagName('input')) {
+ if (cb.parentElement.parentElement.classList.contains('eliminated'))
+ continue;
+ cb.addEventListener('click', (function(cb) {
+ return function() {
+ cb.style.display = 'none'
+ const spin = document.createElement('div')
+ spin.appendChild(document.createTextNode('⏳'))
+ cb.parentElement.insertBefore(spin, cb)
+
+ const req = new XMLHttpRequest()
+ req.addEventListener('load', function(e) {
+ cb.parentElement.removeChild(cb.previousElementSibling)
+ if (req.status == 200) {
+ cb.style.display = ''
+ const delta = cb.checked ? 1 : -1
+ const count_td = cb.parentElement.previousElementSibling
+ count_td.textContent = parseInt(count_td.textContent) + delta
+ } else {
+ cb.parentElement.insertBefore(document.createTextNode('❗'), cb)
+ }
+ })
+ req.open('PUT', window.location.href)
+ req.send((cb.checked ? 1 : 0) + ' ' + cb.parentElement.nextElementSibling.innerHTML)
+ }
+ })(cb))
+ cb.disabled = false
+ }
+ }
+ function num_cmp(a, b) {
+ return parseInt(b.textContent) - parseInt(a.textContent)
+ }
+ function str_cmp(a, b) {
+ if (a.textContent < b.textContent) return -1
+ if (a.textContent > b.textContent) return 1
+ return 0
+ }
+ function checked_cmp(a, b) {
+ vs = [a, b].map(x => {
+ const v = x.children[0].checked + 0
+ return isNaN(v) ? -1 : v
+ })
+ return vs[1] - vs[0]
+ }
+ function sort_table(col, cmp) {
+ const rows = Array.from(document.getElementsByTagName('tr'))
+ rows.shift()
+ rows.sort((a, b) => cmp(a.children[col], b.children[col]))
+ for (row of rows) {
+ row.parentElement.appendChild(row)
+ }
+ }
+ </script>
+ </head>
+ <body>
+ <table>
+ <tr>
+ <th onclick='sort_table(0, num_cmp)'>Count</th>
+ <th onclick='sort_table(1, checked_cmp)'>Vote</th>
+ <th onclick='sort_table(2, str_cmp)'>Candidate</th>
+ </tr>";
+const HTML_FOOTER: &str = "
+ </table>
+ </body>
+</html>";
+
+fn supports(tally: &HashMap<String, HashSet<String>>, me: &str, candidate: &str) -> bool {
+ tally
+ .get(candidate)
+ .map_or(false, |supporters| supporters.contains(me))
+}
+
+fn prompt_for_vote(dir: &Path, request: &cgi::Request) -> Result<cgi::Response, cgi::Response> {
+ let voter = get_voter(request);
+ let me = if let Ok(id) = voter {
+ std::str::from_utf8(id).ok()
+ } else {
+ None
+ };
+ let tally = tally_votes(dir).map_err(|_| cgi::text_response(503, "Couldn't tally votes"))?;
+ let elim =
+ read_elim_list(dir).map_err(|_| cgi::text_response(503, "Couldn't read eliminations"))?;
+ let cfile = std::fs::File::open(dir.join("candidates"))
+ .map_err(|_| cgi::text_response(503, "No candidates"))?;
+ let mut response = cgi::html_response(
+ 200,
+ std::iter::once(Ok(HTML_HEADER.to_owned()))
+ .chain(std::io::BufReader::new(cfile).lines().map(|rc| {
+ rc.map(|c| {
+ let count = tally.get(&c).map_or(0, std::collections::HashSet::len);
+ let checked = if me.map_or(false, |me| supports(&tally, me, &c)) {
+ "checked"
+ } else {
+ ""
+ };
+ let class = if elim.contains(&c) { "eliminated" } else { "" };
+ format!(
+ "<tr class=\"{class}\">
+ <td>{count}</td>
+ <td><input type=\"checkbox\" autocomplete=\"off\" {checked} disabled></td>
+ <td>{c}</td>
+ </tr>"
+ )
+ })
+ }))
+ .chain(std::iter::once(Ok(HTML_FOOTER.to_owned())))
+ .collect::<std::io::Result<String>>()
+ .map_err(|_| cgi::text_response(503, "Missing candidates"))?,
+ );
+ if voter.is_err() {
+ response = set_cookie(response, request.uri().path())?;
+ }
+ Ok(response)
+}
+
+fn write_vote(dir: &Path, voter: &[u8], vote: &[u8]) -> std::io::Result<()> {
+ let datum = [voter, b" ", vote, b"\n"].concat();
+ let vpath = dir.join("votes");
+ let vfile = std::fs::File::options()
+ .append(true)
+ .create(true)
+ .open(vpath)?;
+ let mut vlock = fd_lock::RwLock::new(vfile);
+ vlock.write()?.write_all(&datum)?;
+ Ok(())
+}
+
+fn record_vote(dir: &Path, request: &cgi::Request) -> Result<cgi::Response, cgi::Response> {
+ let body = request.body();
+ // Valid votes look like "0 foo" or "1 bar"
+ if body.len() < 3
+ || (body[0] != b'0' && body[0] != b'1')
+ || body[1] != b' '
+ || body.contains(&b'\n')
+ {
+ return Err(cgi::text_response(415, "Invalid vote"));
+ }
+ write_vote(dir, get_voter(request)?, body)
+ .map_err(|_| cgi::text_response(503, "Couldn't record vote"))?;
+ Ok(cgi::text_response(200, "Vote recorded"))
projects / voter / blobdiff