lix/tests/unit/libstore/filetransfer.cc
eldritch horrors dd4a2c1759 libstore: fix http abuses no longer working
while refactoring the curl wrapper we inadvertently broken the immutable
flake protocol, because the immutable flake protocol accumulates headers
across the entire redirect chain instead of using only the headers given
in the final response of the chain. this is a problem because Some Known
Providers Of Flake Infrastructure set rel=immutable link headers only in
the penultimate entry of the redirect chain, and curl does not regard it
as worth returning to us via its response header enumeration mechanisms.

fixes #358

Change-Id: I645c3932b465cde848bd6a3565925a1e3cbcdda0
2024-05-29 22:35:29 +00:00

213 lines
6.2 KiB
C++

#include "filetransfer.hh"
#include "compression.hh"
#include <cstdint>
#include <exception>
#include <future>
#include <gtest/gtest.h>
#include <netinet/in.h>
#include <stdexcept>
#include <string_view>
#include <sys/poll.h>
#include <sys/socket.h>
#include <thread>
#include <unistd.h>
// local server tests don't work on darwin without some incantations
// the horrors do not want to look up. contributions welcome though!
#if __APPLE__
#define NOT_ON_DARWIN(n) DISABLED_##n
#else
#define NOT_ON_DARWIN(n) n
#endif
using namespace std::chrono_literals;
namespace {
struct Reply {
std::string status, headers;
std::function<std::string()> content;
};
}
namespace nix {
static std::tuple<uint16_t, AutoCloseFD>
serveHTTP(std::vector<Reply> replies)
{
AutoCloseFD listener(::socket(AF_INET6, SOCK_STREAM, 0));
if (!listener) {
throw SysError(errno, "socket() failed");
}
Pipe trigger;
trigger.create();
sockaddr_in6 addr = {
.sin6_family = AF_INET6,
.sin6_addr = IN6ADDR_LOOPBACK_INIT,
};
socklen_t len = sizeof(addr);
if (::bind(listener.get(), reinterpret_cast<const sockaddr *>(&addr), sizeof(addr)) < 0) {
throw SysError(errno, "bind() failed");
}
if (::getsockname(listener.get(), reinterpret_cast<sockaddr *>(&addr), &len) < 0) {
throw SysError(errno, "getsockname() failed");
}
if (::listen(listener.get(), 1) < 0) {
throw SysError(errno, "listen() failed");
}
std::thread(
[replies, at{0}](AutoCloseFD socket, AutoCloseFD trigger) mutable {
while (true) {
pollfd pfds[2] = {
{
.fd = socket.get(),
.events = POLLIN,
},
{
.fd = trigger.get(),
.events = POLLHUP,
},
};
if (::poll(pfds, 2, -1) <= 0) {
throw SysError(errno, "poll() failed");
}
if (pfds[1].revents & POLLHUP) {
return;
}
if (!(pfds[0].revents & POLLIN)) {
continue;
}
AutoCloseFD conn(::accept(socket.get(), nullptr, nullptr));
if (!conn) {
throw SysError(errno, "accept() failed");
}
auto send = [&](std::string_view bit) {
while (!bit.empty()) {
auto written = ::write(conn.get(), bit.data(), bit.size());
if (written < 0) {
throw SysError(errno, "write() failed");
}
bit.remove_prefix(written);
}
};
const auto & reply = replies[at++ % replies.size()];
send("HTTP/1.1 ");
send(reply.status);
send("\r\n");
send(reply.headers);
send("\r\n");
send(reply.content());
::shutdown(conn.get(), SHUT_RDWR);
}
},
std::move(listener),
std::move(trigger.readSide)
)
.detach();
return {
ntohs(addr.sin6_port),
std::move(trigger.writeSide),
};
}
static std::tuple<uint16_t, AutoCloseFD>
serveHTTP(std::string status, std::string headers, std::function<std::string()> content)
{
return serveHTTP({{{status, headers, content}}});
}
TEST(FileTransfer, exceptionAbortsDownload)
{
struct Done
{};
auto ft = makeFileTransfer();
LambdaSink broken([](auto block) { throw Done(); });
ASSERT_THROW(ft->download(FileTransferRequest("file:///dev/zero"), broken), Done);
// makeFileTransfer returns a ref<>, which cannot be cleared. since we also
// can't default-construct it we'll have to overwrite it instead, but we'll
// take the raw pointer out first so we can destroy it in a detached thread
// (otherwise a failure will stall the process and have it killed by meson)
auto reset = std::async(std::launch::async, [&]() { ft = makeFileTransfer(); });
EXPECT_EQ(reset.wait_for(10s), std::future_status::ready);
// if this did time out we have to leak `reset`.
if (reset.wait_for(0s) == std::future_status::timeout) {
(void) new auto(std::move(reset));
}
}
TEST(FileTransfer, NOT_ON_DARWIN(reportsSetupErrors))
{
auto [port, srv] = serveHTTP("404 not found", "", [] { return ""; });
auto ft = makeFileTransfer();
ASSERT_THROW(
ft->download(FileTransferRequest(fmt("http://[::1]:%d/index", port))),
FileTransferError);
}
TEST(FileTransfer, NOT_ON_DARWIN(reportsTransferError))
{
auto [port, srv] = serveHTTP("200 ok", "content-length: 100\r\n", [] {
std::this_thread::sleep_for(10ms);
return "";
});
auto ft = makeFileTransfer();
FileTransferRequest req(fmt("http://[::1]:%d/index", port));
req.baseRetryTimeMs = 0;
ASSERT_THROW(ft->download(req), FileTransferError);
}
TEST(FileTransfer, NOT_ON_DARWIN(handlesContentEncoding))
{
std::string original = "Test data string";
std::string compressed = compress("gzip", original);
auto [port, srv] = serveHTTP("200 ok", "content-encoding: gzip\r\n", [&] { return compressed; });
auto ft = makeFileTransfer();
StringSink sink;
ft->download(FileTransferRequest(fmt("http://[::1]:%d/index", port)), sink);
EXPECT_EQ(sink.s, original);
}
TEST(FileTransfer, usesIntermediateLinkHeaders)
{
auto [port, srv] = serveHTTP({
{"301 ok",
"location: /second\r\n"
"content-length: 0\r\n",
[] { return ""; }},
{"307 ok",
"location: /third\r\n"
"content-length: 0\r\n",
[] { return ""; }},
{"307 ok",
"location: /fourth\r\n"
"link: <http://foo>; rel=\"immutable\"\r\n"
"content-length: 0\r\n",
[] { return ""; }},
{"200 ok", "content-length: 1\r\n", [] { return "a"; }},
});
auto ft = makeFileTransfer();
FileTransferRequest req(fmt("http://[::1]:%d/first", port));
req.baseRetryTimeMs = 0;
auto result = ft->download(req);
ASSERT_EQ(result.immutableUrl, "http://foo");
}
}