Files
scylladb/alternator/server.cc
Vlad Zolotarov 28cbaef110 service/client_state and alternator/server: use cached values for driver_name and driver_version fields
Optimize memory usage changing types of driver_name and driver_version be
a reference to a cached value instead of an sstring.

These fields very often have the same value among different connections hence
it makes sense to cache these values and use references to them instead of duplicating
such strings in each connection state.

Signed-off-by: Vlad Zolotarov <vladz@scylladb.com>
2025-12-20 12:26:22 -05:00

1009 lines
52 KiB
C++

/*
* Copyright 2019-present ScyllaDB
*/
/*
* SPDX-License-Identifier: LicenseRef-ScyllaDB-Source-Available-1.0
*/
#include "alternator/server.hh"
#include "gms/application_state.hh"
#include "utils/log.hh"
#include <fmt/ranges.h>
#include <seastar/http/function_handlers.hh>
#include <seastar/http/short_streams.hh>
#include <seastar/core/coroutine.hh>
#include <seastar/coroutine/maybe_yield.hh>
#include <seastar/util/defer.hh>
#include <seastar/util/short_streams.hh>
#include "seastarx.hh"
#include "error.hh"
#include "service/client_state.hh"
#include "service/qos/service_level_controller.hh"
#include "utils/assert.hh"
#include "timeout_config.hh"
#include "utils/rjson.hh"
#include "auth.hh"
#include <cctype>
#include <string_view>
#include <utility>
#include "service/storage_proxy.hh"
#include "gms/gossiper.hh"
#include "utils/overloaded_functor.hh"
#include "utils/aws_sigv4.hh"
#include "client_data.hh"
#include "utils/updateable_value.hh"
#include <zlib.h>
static logging::logger slogger("alternator-server");
using namespace httpd;
using request = http::request;
using reply = http::reply;
namespace alternator {
inline std::vector<std::string_view> split(std::string_view text, char separator) {
std::vector<std::string_view> tokens;
if (text == "") {
return tokens;
}
while (true) {
auto pos = text.find_first_of(separator);
if (pos != std::string_view::npos) {
tokens.emplace_back(text.data(), pos);
text.remove_prefix(pos + 1);
} else {
tokens.emplace_back(text);
break;
}
}
return tokens;
}
// Handle CORS (Cross-origin resource sharing) in the HTTP request:
// If the request has the "Origin" header specifying where the script which
// makes this request comes from, we need to reply with the header
// "Access-Control-Allow-Origin: *" saying that this (and any) origin is fine.
// Additionally, if preflight==true (i.e., this is an OPTIONS request),
// the script can also "request" in headers that the server allows it to use
// some HTTP methods and headers in the followup request, and the server
// should respond by "allowing" them in the response headers.
// We also add the header "Access-Control-Expose-Headers" to let the script
// access additional headers in the response.
// This handle_CORS() should be used when handling any HTTP method - both the
// usual GET and POST, and also the "preflight" OPTIONS method.
static void handle_CORS(const request& req, reply& rep, bool preflight) {
if (!req.get_header("origin").empty()) {
rep.add_header("Access-Control-Allow-Origin", "*");
// This is the list that DynamoDB returns for expose headers. I am
// not sure why not just return "*" here, what's the risk?
rep.add_header("Access-Control-Expose-Headers", "x-amzn-RequestId,x-amzn-ErrorType,x-amzn-ErrorMessage,Date");
if (preflight) {
sstring s = req.get_header("Access-Control-Request-Headers");
if (!s.empty()) {
rep.add_header("Access-Control-Allow-Headers", std::move(s));
}
s = req.get_header("Access-Control-Request-Method");
if (!s.empty()) {
rep.add_header("Access-Control-Allow-Methods", std::move(s));
}
// Our CORS response never change anyway, let the browser cache it
// for two hours (Chrome's maximum):
rep.add_header("Access-Control-Max-Age", "7200");
}
}
}
// DynamoDB HTTP error responses are structured as follows
// https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Programming.Errors.html
// Our handlers throw an exception to report an error. If the exception
// is of type alternator::api_error, it unwrapped and properly reported to
// the user directly. Other exceptions are unexpected, and reported as
// Internal Server Error.
class api_handler : public handler_base {
// Although the the DynamoDB API responses are JSON, additional
// conventions apply to these responses. For this reason, DynamoDB uses
// the content type "application/x-amz-json-1.0" instead of the standard
// "application/json". Some other AWS services use later versions instead
// of "1.0", but DynamoDB currently uses "1.0". Note that this content
// type applies to all replies, both success and error.
static constexpr const char* REPLY_CONTENT_TYPE = "application/x-amz-json-1.0";
public:
api_handler(const std::function<future<executor::request_return_type>(std::unique_ptr<request> req)>& _handle) : _f_handle(
[this, _handle](std::unique_ptr<request> req, std::unique_ptr<reply> rep) {
return seastar::futurize_invoke(_handle, std::move(req)).then_wrapped([this, rep = std::move(rep)](future<executor::request_return_type> resf) mutable {
if (resf.failed()) {
// Exceptions of type api_error are wrapped as JSON and
// returned to the client as expected. Other types of
// exceptions are unexpected, and returned to the user
// as an internal server error:
try {
resf.get();
} catch (api_error &ae) {
generate_error_reply(*rep, ae);
} catch (rjson::error & re) {
generate_error_reply(*rep,
api_error::validation(re.what()));
} catch (...) {
generate_error_reply(*rep,
api_error::internal(format("Internal server error: {}", std::current_exception())));
}
return make_ready_future<std::unique_ptr<reply>>(std::move(rep));
}
auto res = resf.get();
std::visit(overloaded_functor {
[&] (std::string&& str) {
// Note that despite the move, there is a copy here -
// as str is std::string and rep->_content is sstring.
rep->_content = std::move(str);
rep->set_content_type(REPLY_CONTENT_TYPE);
},
[&] (executor::body_writer&& body_writer) {
rep->write_body(REPLY_CONTENT_TYPE, std::move(body_writer));
},
[&] (const api_error& err) {
generate_error_reply(*rep, err);
}
}, std::move(res));
return make_ready_future<std::unique_ptr<reply>>(std::move(rep));
});
}) { }
api_handler(const api_handler&) = default;
future<std::unique_ptr<reply>> handle(const sstring& path,
std::unique_ptr<request> req, std::unique_ptr<reply> rep) override {
handle_CORS(*req, *rep, false);
return _f_handle(std::move(req), std::move(rep)).then(
[](std::unique_ptr<reply> rep) {
rep->done();
return make_ready_future<std::unique_ptr<reply>>(std::move(rep));
});
}
protected:
void generate_error_reply(reply& rep, const api_error& err) {
rjson::value results = rjson::empty_object();
if (!err._extra_fields.IsNull() && err._extra_fields.IsObject()) {
results = rjson::copy(err._extra_fields);
}
rjson::add(results, "__type", rjson::from_string("com.amazonaws.dynamodb.v20120810#" + err._type));
rjson::add(results, "message", err._msg);
rep._content = rjson::print(std::move(results));
rep._status = err._http_code;
rep.set_content_type(REPLY_CONTENT_TYPE);
slogger.trace("api_handler error case: {}", rep._content);
}
future_handler_function _f_handle;
};
class gated_handler : public handler_base {
seastar::gate& _gate;
public:
gated_handler(seastar::gate& gate) : _gate(gate) {}
virtual future<std::unique_ptr<reply>> do_handle(const sstring& path, std::unique_ptr<request> req, std::unique_ptr<reply> rep) = 0;
virtual future<std::unique_ptr<reply>> handle(const sstring& path, std::unique_ptr<request> req, std::unique_ptr<reply> rep) final override {
return with_gate(_gate, [this, &path, req = std::move(req), rep = std::move(rep)] () mutable {
return do_handle(path, std::move(req), std::move(rep));
});
}
};
class health_handler : public gated_handler {
public:
health_handler(seastar::gate& pending_requests) : gated_handler(pending_requests) {}
protected:
virtual future<std::unique_ptr<reply>> do_handle(const sstring& path, std::unique_ptr<request> req, std::unique_ptr<reply> rep) override {
handle_CORS(*req, *rep, false);
rep->set_status(reply::status_type::ok);
rep->write_body("txt", format("healthy: {}", req->get_header("Host")));
return make_ready_future<std::unique_ptr<reply>>(std::move(rep));
}
};
class local_nodelist_handler : public gated_handler {
service::storage_proxy& _proxy;
gms::gossiper& _gossiper;
public:
local_nodelist_handler(seastar::gate& pending_requests, service::storage_proxy& proxy, gms::gossiper& gossiper)
: gated_handler(pending_requests)
, _proxy(proxy)
, _gossiper(gossiper) {}
protected:
virtual future<std::unique_ptr<reply>> do_handle(const sstring& path, std::unique_ptr<request> req, std::unique_ptr<reply> rep) override {
rjson::value results = rjson::empty_array();
// It's very easy to get a list of all live nodes on the cluster,
// using _gossiper().get_live_members(). But getting
// just the list of live nodes in this DC needs more elaborate code:
auto& topology = _proxy.get_token_metadata_ptr()->get_topology();
// /localnodes lists nodes in a single DC. By default the DC of this
// server is used, but it can be overridden by a "dc" query option.
// If the DC does not exist, we return an empty list - not an error.
sstring query_dc = req->get_query_param("dc");
sstring local_dc = query_dc.empty() ? topology.get_datacenter() : query_dc;
std::unordered_set<locator::host_id> local_dc_nodes;
const auto& endpoints = topology.get_datacenter_endpoints();
auto dc_it = endpoints.find(local_dc);
if (dc_it != endpoints.end()) {
local_dc_nodes = dc_it->second;
}
// By default, /localnodes lists the nodes of all racks in the given
// DC, unless a single rack is selected by the "rack" query option.
// If the rack does not exist, we return an empty list - not an error.
sstring query_rack = req->get_query_param("rack");
for (auto& id : local_dc_nodes) {
if (!query_rack.empty()) {
auto rack = _gossiper.get_application_state_value(id, gms::application_state::RACK);
if (rack != query_rack) {
continue;
}
}
// Note that it's not enough for the node to be is_alive() - a
// node joining the cluster is also "alive" but not responsive to
// requests. We alive *and* normal. See #19694, #21538.
if (_gossiper.is_alive(id) && _gossiper.is_normal(id)) {
// Use the gossiped broadcast_rpc_address if available instead
// of the internal IP address "ip". See discussion in #18711.
rjson::push_back(results, rjson::from_string(_gossiper.get_rpc_address(id)));
}
}
rep->set_status(reply::status_type::ok);
rep->set_content_type("json");
rep->_content = rjson::print(results);
return make_ready_future<std::unique_ptr<reply>>(std::move(rep));
}
};
// The CORS (Cross-origin resource sharing) protocol can send an OPTIONS
// request before ("pre-flight") the main request. The response to this
// request can be empty, but needs to have the right headers (which we
// fill with handle_CORS())
class options_handler : public gated_handler {
public:
options_handler(seastar::gate& pending_requests) : gated_handler(pending_requests) {}
protected:
virtual future<std::unique_ptr<reply>> do_handle(const sstring& path, std::unique_ptr<request> req, std::unique_ptr<reply> rep) override {
handle_CORS(*req, *rep, true);
rep->set_status(reply::status_type::ok);
rep->write_body("txt", sstring(""));
return make_ready_future<std::unique_ptr<reply>>(std::move(rep));
}
};
// This function increments the authentication_failures counter, and may also
// log a warn-level message and/or throw an exception, depending on what
// enforce_authorization and warn_authorization are set to.
// The username and client address are only used for logging purposes -
// they are not included in the error message returned to the client, since
// the client knows who it is.
// Note that if enforce_authorization is false, this function will return
// without throwing. So a caller that doesn't want to continue after an
// authentication_error must explicitly return after calling this function.
template<typename Exception>
static void authentication_error(alternator::stats& stats, bool enforce_authorization, bool warn_authorization, Exception&& e, std::string_view user, gms::inet_address client_address) {
stats.authentication_failures++;
if (enforce_authorization) {
if (warn_authorization) {
slogger.warn("alternator_warn_authorization=true: {} for user {}, client address {}", e.what(), user, client_address);
}
throw std::move(e);
} else {
if (warn_authorization) {
slogger.warn("If you set alternator_enforce_authorization=true the following will be enforced: {} for user {}, client address {}", e.what(), user, client_address);
}
}
}
future<std::string> server::verify_signature(const request& req, const chunked_content& content) {
if (!_enforce_authorization.get() && !_warn_authorization.get()) {
slogger.debug("Skipping authorization");
return make_ready_future<std::string>();
}
auto host_it = req._headers.find("Host");
if (host_it == req._headers.end()) {
authentication_error(_executor._stats, _enforce_authorization.get(), _warn_authorization.get(),
api_error::invalid_signature("Host header is mandatory for signature verification"),
"", req.get_client_address());
return make_ready_future<std::string>();
}
auto authorization_it = req._headers.find("Authorization");
if (authorization_it == req._headers.end()) {
authentication_error(_executor._stats, _enforce_authorization.get(), _warn_authorization.get(),
api_error::missing_authentication_token("Authorization header is mandatory for signature verification"),
"", req.get_client_address());
return make_ready_future<std::string>();
}
std::string host = host_it->second;
std::string_view authorization_header = authorization_it->second;
auto pos = authorization_header.find_first_of(' ');
if (pos == std::string_view::npos || authorization_header.substr(0, pos) != "AWS4-HMAC-SHA256") {
authentication_error(_executor._stats, _enforce_authorization.get(), _warn_authorization.get(),
api_error::invalid_signature(fmt::format("Authorization header must use AWS4-HMAC-SHA256 algorithm: {}", authorization_header)),
"", req.get_client_address());
return make_ready_future<std::string>();
}
authorization_header.remove_prefix(pos+1);
std::string credential;
std::string user_signature;
std::string signed_headers_str;
std::vector<std::string_view> signed_headers;
do {
// Either one of a comma or space can mark the end of an entry
pos = authorization_header.find_first_of(" ,");
std::string_view entry = authorization_header.substr(0, pos);
if (pos != std::string_view::npos) {
authorization_header.remove_prefix(pos + 1);
}
if (entry.empty()) {
continue;
}
std::vector<std::string_view> entry_split = split(entry, '=');
if (entry_split.size() != 2) {
continue;
}
std::string_view auth_value = entry_split[1];
if (entry_split[0] == "Credential") {
credential = std::string(auth_value);
} else if (entry_split[0] == "Signature") {
user_signature = std::string(auth_value);
} else if (entry_split[0] == "SignedHeaders") {
signed_headers_str = std::string(auth_value);
signed_headers = split(auth_value, ';');
std::sort(signed_headers.begin(), signed_headers.end());
}
} while (pos != std::string_view::npos);
std::vector<std::string_view> credential_split = split(credential, '/');
if (credential_split.size() != 5) {
authentication_error(_executor._stats, _enforce_authorization.get(), _warn_authorization.get(),
api_error::validation(fmt::format("Incorrect credential information format: {}", credential)), "", req.get_client_address());
return make_ready_future<std::string>();
}
std::string user(credential_split[0]);
std::string datestamp(credential_split[1]);
std::string region(credential_split[2]);
std::string service(credential_split[3]);
std::map<std::string_view, std::string_view> signed_headers_map;
for (const auto& header : signed_headers) {
signed_headers_map.emplace(header, std::string_view());
}
for (auto& header : req._headers) {
std::string header_str;
header_str.resize(header.first.size());
std::transform(header.first.begin(), header.first.end(), header_str.begin(), ::tolower);
auto it = signed_headers_map.find(header_str);
if (it != signed_headers_map.end()) {
it->second = std::string_view(header.second);
}
}
auto cache_getter = [&proxy = _proxy, &as = _auth_service] (std::string username) {
return get_key_from_roles(proxy, as, std::move(username));
};
return _key_cache.get_ptr(user, cache_getter).then_wrapped([this, &req, &content,
user = std::move(user),
host = std::move(host),
datestamp = std::move(datestamp),
signed_headers_str = std::move(signed_headers_str),
signed_headers_map = std::move(signed_headers_map),
region = std::move(region),
service = std::move(service),
user_signature = std::move(user_signature)] (future<key_cache::value_ptr> key_ptr_fut) {
key_cache::value_ptr key_ptr(nullptr);
try {
key_ptr = key_ptr_fut.get();
} catch (const api_error& e) {
authentication_error(_executor._stats, _enforce_authorization.get(), _warn_authorization.get(),
e, user, req.get_client_address());
return std::string();
}
std::string signature;
try {
signature = utils::aws::get_signature(user, *key_ptr, std::string_view(host), "/", req._method,
datestamp, signed_headers_str, signed_headers_map, &content, region, service, "");
} catch (const std::exception& e) {
authentication_error(_executor._stats, _enforce_authorization.get(), _warn_authorization.get(),
api_error::invalid_signature(fmt::format("invalid signature: {}", e.what())),
user, req.get_client_address());
return std::string();
}
if (signature != std::string_view(user_signature)) {
_key_cache.remove(user);
authentication_error(_executor._stats, _enforce_authorization.get(), _warn_authorization.get(),
api_error::unrecognized_client("wrong signature"),
user, req.get_client_address());
return std::string();
}
return user;
});
}
static tracing::trace_state_ptr create_tracing_session(tracing::tracing& tracing_instance) {
tracing::trace_state_props_set props;
props.set<tracing::trace_state_props::full_tracing>();
props.set_if<tracing::trace_state_props::log_slow_query>(tracing_instance.slow_query_tracing_enabled());
return tracing_instance.create_session(tracing::trace_type::QUERY, props);
}
// A helper class to represent a potentially truncated view of a chunked_content.
// If the content is short enough and single chunked, it just holds a view into the content.
// Otherwise it will be copied into an internal buffer, possibly truncated (depending on maximum allowed size passed in),
// and the view will point into that buffer.
// `as_view()` method will return the view.
// `take_as_sstring()` will either move out the internal buffer (if any), or create a new sstring from the view.
// You should consider `as_view()` valid as long both the original chunked_content and the truncated_content object are alive.
class truncated_content {
std::string_view _view;
sstring _content_maybe;
void copy_from_content(const chunked_content& content) {
size_t offset = 0;
for(auto &tmp : content) {
size_t to_copy = std::min(tmp.size(), _content_maybe.size() - offset);
std::copy(tmp.get(), tmp.get() + to_copy, _content_maybe.data() + offset);
offset += to_copy;
if (offset >= _content_maybe.size()) {
break;
}
}
}
public:
truncated_content(const chunked_content& content, size_t max_len = std::numeric_limits<size_t>::max()) {
if (content.empty()) return;
if (content.size() == 1 && content.begin()->size() <= max_len) {
_view = std::string_view(content.begin()->get(), content.begin()->size());
return;
}
constexpr std::string_view truncated_text = "<truncated>";
size_t content_size = 0;
for(auto &tmp : content) {
content_size += tmp.size();
}
if (content_size <= max_len) {
_content_maybe = sstring{ sstring::initialized_later{}, content_size };
copy_from_content(content);
}
else {
_content_maybe = sstring{ sstring::initialized_later{}, max_len + truncated_text.size() };
copy_from_content(content);
std::copy(truncated_text.begin(), truncated_text.end(), _content_maybe.data() + _content_maybe.size() - truncated_text.size());
}
_view = std::string_view(_content_maybe);
}
std::string_view as_view() const { return _view; }
sstring take_as_sstring() && {
if (_content_maybe.empty() && !_view.empty()) {
return sstring{_view};
}
return std::move(_content_maybe);
}
};
// `truncated_content_view` will produce an object representing a view to a passed content
// possibly truncated at some length. The value returned is used in two ways:
// - to print it in logs (use `as_view()` method for this)
// - to pass it to tracing object, where it will be stored and used later
// (use `take_as_sstring()` method as this produces a copy in form of a sstring)
// `truncated_content` delays constructing `sstring` object until it's actually needed.
// `truncated_content` is valid as long as passed `content` is alive.
// if the content is truncated, `<truncated>` will be appended at the maximum size limit
// and total size will be `max_users_query_size_in_trace_output() + strlen("<truncated>")`.
static truncated_content truncated_content_view(const chunked_content& content, size_t max_size) {
return truncated_content{content, max_size};
}
static tracing::trace_state_ptr maybe_trace_query(service::client_state& client_state, std::string_view username, std::string_view op, const chunked_content& query, size_t max_users_query_size_in_trace_output) {
tracing::trace_state_ptr trace_state;
tracing::tracing& tracing_instance = tracing::tracing::get_local_tracing_instance();
if (tracing_instance.trace_next_query() || tracing_instance.slow_query_tracing_enabled()) {
trace_state = create_tracing_session(tracing_instance);
tracing::add_session_param(trace_state, "alternator_op", op);
tracing::add_query(trace_state, truncated_content_view(query, max_users_query_size_in_trace_output).take_as_sstring());
tracing::begin(trace_state, seastar::format("Alternator {}", op), client_state.get_client_address());
if (!username.empty()) {
tracing::set_username(trace_state, auth::authenticated_user(username));
}
}
return trace_state;
}
// This read_entire_stream() is similar to Seastar's read_entire_stream()
// which reads the given content_stream until its end into non-contiguous
// memory. The difference is that this implementation takes an extra length
// limit, and throws an error if we read more than this limit.
// This length-limited variant would not have been needed if Seastar's HTTP
// server's set_content_length_limit() worked in every case, but unfortunately
// it does not - it only works if the request has a Content-Length header (see
// issue #8196). In contrast this function can limit the request's length no
// matter how it's encoded. We need this limit to protect Alternator from
// oversized requests that can deplete memory.
static future<chunked_content>
read_entire_stream(input_stream<char>& inp, size_t length_limit) {
chunked_content ret;
// We try to read length_limit + 1 bytes, so that we can throw an
// exception if we managed to read more than length_limit.
ssize_t remain = length_limit + 1;
do {
temporary_buffer<char> buf = co_await inp.read_up_to(remain);
if (buf.empty()) {
break;
}
remain -= buf.size();
ret.push_back(std::move(buf));
} while (remain > 0);
// If we read the full length_limit + 1 bytes, we went over the limit:
if (remain <= 0) {
// By throwing here an error, we may send a reply (the error message)
// without having read the full request body. Seastar's httpd will
// realize that we have not read the entire content stream, and
// correctly mark the connection unreusable, i.e., close it.
// This means we are currently exposed to issue #12166 caused by
// Seastar issue 1325), where the client may get an RST instead of
// a FIN, and may rarely get a "Connection reset by peer" before
// reading the error we send.
throw api_error::payload_too_large(fmt::format("Request content length limit of {} bytes exceeded", length_limit));
}
co_return ret;
}
// safe_gzip_stream is an exception-safe wrapper for zlib's z_stream.
// The "z_stream" struct is used by zlib to hold state while decompressing a
// stream of data. It allocates memory which must be freed with inflateEnd(),
// which the destructor of this class does.
class safe_gzip_zstream {
z_stream _zs;
public:
safe_gzip_zstream() {
memset(&_zs, 0, sizeof(_zs));
// The strange 16 + WMAX_BITS tells zlib to expect and decode
// a gzip header, not a zlib header.
if (inflateInit2(&_zs, 16 + MAX_WBITS) != Z_OK) {
// Should only happen if memory allocation fails
throw std::bad_alloc();
}
}
~safe_gzip_zstream() {
inflateEnd(&_zs);
}
z_stream* operator->() {
return &_zs;
}
z_stream* get() {
return &_zs;
}
void reset() {
inflateReset(&_zs);
}
};
// ungzip() takes a chunked_content with a gzip-compressed request body,
// uncompresses it, and returns the uncompressed content as a chunked_content.
// If the uncompressed content exceeds length_limit, an error is thrown.
static future<chunked_content>
ungzip(chunked_content&& compressed_body, size_t length_limit) {
chunked_content ret;
// output_buf can be any size - when uncompressing input_buf, it doesn't
// need to fit in a single output_buf, we'll use multiple output_buf for
// a single input_buf if needed.
constexpr size_t OUTPUT_BUF_SIZE = 4096;
temporary_buffer<char> output_buf;
safe_gzip_zstream strm;
bool complete_stream = false; // empty input is not a valid gzip
size_t total_out_bytes = 0;
for (const temporary_buffer<char>& input_buf : compressed_body) {
if (input_buf.empty()) {
continue;
}
complete_stream = false;
strm->next_in = (Bytef*) input_buf.get();
strm->avail_in = (uInt) input_buf.size();
do {
co_await coroutine::maybe_yield();
if (output_buf.empty()) {
output_buf = temporary_buffer<char>(OUTPUT_BUF_SIZE);
}
strm->next_out = (Bytef*) output_buf.get();
strm->avail_out = OUTPUT_BUF_SIZE;
int e = inflate(strm.get(), Z_NO_FLUSH);
size_t out_bytes = OUTPUT_BUF_SIZE - strm->avail_out;
if (out_bytes > 0) {
// If output_buf is nearly full, we save it as-is in ret. But
// if it only has little data, better copy to a small buffer.
if (out_bytes > OUTPUT_BUF_SIZE/2) {
ret.push_back(std::move(output_buf).prefix(out_bytes));
// output_buf is now empty. if this loop finds more input,
// we'll allocate a new output buffer.
} else {
ret.push_back(temporary_buffer<char>(output_buf.get(), out_bytes));
}
total_out_bytes += out_bytes;
if (total_out_bytes > length_limit) {
throw api_error::payload_too_large(fmt::format("Request content length limit of {} bytes exceeded", length_limit));
}
}
if (e == Z_STREAM_END) {
// There may be more input after the first gzip stream - in
// either this input_buf or the next one. The additional input
// should be a second concatenated gzip. We need to allow that
// by resetting the gzip stream and continuing the input loop
// until there's no more input.
strm.reset();
if (strm->avail_in == 0) {
complete_stream = true;
break;
}
} else if (e != Z_OK && e != Z_BUF_ERROR) {
// DynamoDB returns an InternalServerError when given a bad
// gzip request body. See test test_broken_gzip_content
throw api_error::internal("Error during gzip decompression of request body");
}
} while (strm->avail_in > 0 || strm->avail_out == 0);
}
if (!complete_stream) {
// The gzip stream was not properly finished with Z_STREAM_END
throw api_error::internal("Truncated gzip in request body");
}
co_return ret;
}
future<executor::request_return_type> server::handle_api_request(std::unique_ptr<request> req) {
_executor._stats.total_operations++;
sstring target = req->get_header("X-Amz-Target");
// target is DynamoDB API version followed by a dot '.' and operation type (e.g. CreateTable)
auto dot = target.find('.');
std::string_view op = (dot == sstring::npos) ? std::string_view() : std::string_view(target).substr(dot+1);
if (req->content_length > request_content_length_limit) {
// If we have a Content-Length header and know the request will be too
// long, we don't need to wait for read_entire_stream() below to
// discover it. And we definitely mustn't try to get_units() below for
// for such a size.
co_return api_error::payload_too_large(fmt::format("Request content length limit of {} bytes exceeded", request_content_length_limit));
}
// JSON parsing can allocate up to roughly 2x the size of the raw
// document, + a couple of bytes for maintenance.
// If the Content-Length of the request is not available, we assume
// the largest possible request (request_content_length_limit, i.e., 16 MB)
// and after reading the request we return_units() the excess.
size_t mem_estimate = (req->content_length ? req->content_length : request_content_length_limit) * 2 + 8000;
auto units_fut = get_units(*_memory_limiter, mem_estimate);
if (_memory_limiter->waiters()) {
++_executor._stats.requests_blocked_memory;
}
auto units = co_await std::move(units_fut);
SCYLLA_ASSERT(req->content_stream);
chunked_content content = co_await read_entire_stream(*req->content_stream, request_content_length_limit);
// If the request had no Content-Length, we reserved too many units
// so need to return some
if (req->content_length == 0) {
size_t content_length = 0;
for (const auto& chunk : content) {
content_length += chunk.size();
}
size_t new_mem_estimate = content_length * 2 + 8000;
units.return_units(mem_estimate - new_mem_estimate);
}
auto username = co_await verify_signature(*req, content);
// If the request is compressed, uncompress it now, after we checked
// the signature (the signature is computed on the compressed content).
// We apply the request_content_length_limit again to the uncompressed
// content - we don't want to allow a tiny compressed request to
// expand to a huge uncompressed request.
sstring content_encoding = req->get_header("Content-Encoding");
if (content_encoding == "gzip") {
content = co_await ungzip(std::move(content), request_content_length_limit);
} else if (!content_encoding.empty()) {
// DynamoDB returns a 500 error for unsupported Content-Encoding.
// I'm not sure if this is the best error code, but let's do it too.
// See the test test_garbage_content_encoding confirming this case.
co_return api_error::internal("Unsupported Content-Encoding");
}
// As long as the system_clients_entry object is alive, this request will
// be visible in the "system.clients" virtual table. When requested, this
// entry will be formatted by server::ongoing_request::make_client_data().
auto user_agent_header = co_await _connection_options_keys_and_values.get_or_load(req->get_header("User-Agent"), [] (const client_options_cache_key_type&) {
return make_ready_future<options_cache_value_type>(options_cache_value_type{});
});
auto system_clients_entry = _ongoing_requests.emplace(
req->get_client_address(), std::move(user_agent_header),
username, current_scheduling_group(),
req->get_protocol_name() == "https");
if (slogger.is_enabled(log_level::trace)) {
slogger.trace("Request: {} {} {}", op, truncated_content_view(content, _max_users_query_size_in_trace_output).as_view(), req->_headers);
}
auto callback_it = _callbacks.find(op);
if (callback_it == _callbacks.end()) {
_executor._stats.unsupported_operations++;
co_return api_error::unknown_operation(fmt::format("Unsupported operation {}", op));
}
if (_pending_requests.get_count() >= _max_concurrent_requests) {
_executor._stats.requests_shed++;
co_return api_error::request_limit_exceeded(format("too many in-flight requests (configured via max_concurrent_requests_per_shard): {}", _pending_requests.get_count()));
}
_pending_requests.enter();
auto leave = defer([this] () noexcept { _pending_requests.leave(); });
executor::client_state client_state(service::client_state::external_tag(),
_auth_service, &_sl_controller, _timeout_config.current_values(), req->get_client_address());
if (!username.empty()) {
client_state.set_login(auth::authenticated_user(username));
}
co_await client_state.maybe_update_per_service_level_params();
tracing::trace_state_ptr trace_state = maybe_trace_query(client_state, username, op, content, _max_users_query_size_in_trace_output.get());
tracing::trace(trace_state, "{}", op);
auto user = client_state.user();
auto f = [this, content = std::move(content), &callback = callback_it->second,
client_state = std::move(client_state), trace_state = std::move(trace_state),
units = std::move(units), req = std::move(req)] () mutable -> future<executor::request_return_type> {
rjson::value json_request = co_await _json_parser.parse(std::move(content));
if (!json_request.IsObject()) {
co_return api_error::validation("Request content must be an object");
}
co_return co_await callback(_executor, client_state, trace_state,
make_service_permit(std::move(units)), std::move(json_request), std::move(req));
};
co_return co_await _sl_controller.with_user_service_level(user, std::ref(f));
}
void server::set_routes(routes& r) {
api_handler* req_handler = new api_handler([this] (std::unique_ptr<request> req) mutable {
return handle_api_request(std::move(req));
});
r.put(operation_type::POST, "/", req_handler);
r.put(operation_type::GET, "/", new health_handler(_pending_requests));
// The "/localnodes" request is a new Alternator feature, not supported by
// DynamoDB and not required for DynamoDB compatibility. It allows a
// client to enquire - using a trivial HTTP request without requiring
// authentication - the list of all live nodes in the same data center of
// the Alternator cluster. The client can use this list to balance its
// request load to all the nodes in the same geographical region.
// Note that this API exposes - openly without authentication - the
// information on the cluster's members inside one data center. We do not
// consider this to be a security risk, because an attacker can already
// scan an entire subnet for nodes responding to the health request,
// or even just scan for open ports.
r.put(operation_type::GET, "/localnodes", new local_nodelist_handler(_pending_requests, _proxy, _gossiper));
r.put(operation_type::OPTIONS, "/", new options_handler(_pending_requests));
}
//FIXME: A way to immediately invalidate the cache should be considered,
// e.g. when the system table which stores the keys is changed.
// For now, this propagation may take up to 1 minute.
server::server(executor& exec, service::storage_proxy& proxy, gms::gossiper& gossiper, auth::service& auth_service, qos::service_level_controller& sl_controller)
: _http_server("http-alternator")
, _https_server("https-alternator")
, _executor(exec)
, _proxy(proxy)
, _gossiper(gossiper)
, _auth_service(auth_service)
, _sl_controller(sl_controller)
, _key_cache(1024, 1min, slogger)
, _max_users_query_size_in_trace_output(1024)
, _enabled_servers{}
, _pending_requests("alternator::server::pending_requests")
, _timeout_config(_proxy.data_dictionary().get_config())
, _callbacks{
{"CreateTable", [] (executor& e, executor::client_state& client_state, tracing::trace_state_ptr trace_state, service_permit permit, rjson::value json_request, std::unique_ptr<request> req) {
return e.create_table(client_state, std::move(trace_state), std::move(permit), std::move(json_request));
}},
{"DescribeTable", [] (executor& e, executor::client_state& client_state, tracing::trace_state_ptr trace_state, service_permit permit, rjson::value json_request, std::unique_ptr<request> req) {
return e.describe_table(client_state, std::move(trace_state), std::move(permit), std::move(json_request));
}},
{"DeleteTable", [] (executor& e, executor::client_state& client_state, tracing::trace_state_ptr trace_state, service_permit permit, rjson::value json_request, std::unique_ptr<request> req) {
return e.delete_table(client_state, std::move(trace_state), std::move(permit), std::move(json_request));
}},
{"UpdateTable", [] (executor& e, executor::client_state& client_state, tracing::trace_state_ptr trace_state, service_permit permit, rjson::value json_request, std::unique_ptr<request> req) {
return e.update_table(client_state, std::move(trace_state), std::move(permit), std::move(json_request));
}},
{"PutItem", [] (executor& e, executor::client_state& client_state, tracing::trace_state_ptr trace_state, service_permit permit, rjson::value json_request, std::unique_ptr<request> req) {
return e.put_item(client_state, std::move(trace_state), std::move(permit), std::move(json_request));
}},
{"UpdateItem", [] (executor& e, executor::client_state& client_state, tracing::trace_state_ptr trace_state, service_permit permit, rjson::value json_request, std::unique_ptr<request> req) {
return e.update_item(client_state, std::move(trace_state), std::move(permit), std::move(json_request));
}},
{"GetItem", [] (executor& e, executor::client_state& client_state, tracing::trace_state_ptr trace_state, service_permit permit, rjson::value json_request, std::unique_ptr<request> req) {
return e.get_item(client_state, std::move(trace_state), std::move(permit), std::move(json_request));
}},
{"DeleteItem", [] (executor& e, executor::client_state& client_state, tracing::trace_state_ptr trace_state, service_permit permit, rjson::value json_request, std::unique_ptr<request> req) {
return e.delete_item(client_state, std::move(trace_state), std::move(permit), std::move(json_request));
}},
{"ListTables", [] (executor& e, executor::client_state& client_state, tracing::trace_state_ptr trace_state, service_permit permit, rjson::value json_request, std::unique_ptr<request> req) {
return e.list_tables(client_state, std::move(permit), std::move(json_request));
}},
{"Scan", [] (executor& e, executor::client_state& client_state, tracing::trace_state_ptr trace_state, service_permit permit, rjson::value json_request, std::unique_ptr<request> req) {
return e.scan(client_state, std::move(trace_state), std::move(permit), std::move(json_request));
}},
{"DescribeEndpoints", [] (executor& e, executor::client_state& client_state, tracing::trace_state_ptr trace_state, service_permit permit, rjson::value json_request, std::unique_ptr<request> req) {
return e.describe_endpoints(client_state, std::move(permit), std::move(json_request), req->get_header("Host"));
}},
{"BatchWriteItem", [] (executor& e, executor::client_state& client_state, tracing::trace_state_ptr trace_state, service_permit permit, rjson::value json_request, std::unique_ptr<request> req) {
return e.batch_write_item(client_state, std::move(trace_state), std::move(permit), std::move(json_request));
}},
{"BatchGetItem", [] (executor& e, executor::client_state& client_state, tracing::trace_state_ptr trace_state, service_permit permit, rjson::value json_request, std::unique_ptr<request> req) {
return e.batch_get_item(client_state, std::move(trace_state), std::move(permit), std::move(json_request));
}},
{"Query", [] (executor& e, executor::client_state& client_state, tracing::trace_state_ptr trace_state, service_permit permit, rjson::value json_request, std::unique_ptr<request> req) {
return e.query(client_state, std::move(trace_state), std::move(permit), std::move(json_request));
}},
{"TagResource", [] (executor& e, executor::client_state& client_state, tracing::trace_state_ptr trace_state, service_permit permit, rjson::value json_request, std::unique_ptr<request> req) {
return e.tag_resource(client_state, std::move(permit), std::move(json_request));
}},
{"UntagResource", [] (executor& e, executor::client_state& client_state, tracing::trace_state_ptr trace_state, service_permit permit, rjson::value json_request, std::unique_ptr<request> req) {
return e.untag_resource(client_state, std::move(permit), std::move(json_request));
}},
{"ListTagsOfResource", [] (executor& e, executor::client_state& client_state, tracing::trace_state_ptr trace_state, service_permit permit, rjson::value json_request, std::unique_ptr<request> req) {
return e.list_tags_of_resource(client_state, std::move(permit), std::move(json_request));
}},
{"UpdateTimeToLive", [] (executor& e, executor::client_state& client_state, tracing::trace_state_ptr trace_state, service_permit permit, rjson::value json_request, std::unique_ptr<request> req) {
return e.update_time_to_live(client_state, std::move(permit), std::move(json_request));
}},
{"DescribeTimeToLive", [] (executor& e, executor::client_state& client_state, tracing::trace_state_ptr trace_state, service_permit permit, rjson::value json_request, std::unique_ptr<request> req) {
return e.describe_time_to_live(client_state, std::move(permit), std::move(json_request));
}},
{"ListStreams", [] (executor& e, executor::client_state& client_state, tracing::trace_state_ptr trace_state, service_permit permit, rjson::value json_request, std::unique_ptr<request> req) {
return e.list_streams(client_state, std::move(permit), std::move(json_request));
}},
{"DescribeStream", [] (executor& e, executor::client_state& client_state, tracing::trace_state_ptr trace_state, service_permit permit, rjson::value json_request, std::unique_ptr<request> req) {
return e.describe_stream(client_state, std::move(permit), std::move(json_request));
}},
{"GetShardIterator", [] (executor& e, executor::client_state& client_state, tracing::trace_state_ptr trace_state, service_permit permit, rjson::value json_request, std::unique_ptr<request> req) {
return e.get_shard_iterator(client_state, std::move(permit), std::move(json_request));
}},
{"GetRecords", [] (executor& e, executor::client_state& client_state, tracing::trace_state_ptr trace_state, service_permit permit, rjson::value json_request, std::unique_ptr<request> req) {
return e.get_records(client_state, std::move(trace_state), std::move(permit), std::move(json_request));
}},
{"DescribeContinuousBackups", [] (executor& e, executor::client_state& client_state, tracing::trace_state_ptr trace_state, service_permit permit, rjson::value json_request, std::unique_ptr<request> req) {
return e.describe_continuous_backups(client_state, std::move(permit), std::move(json_request));
}},
} {
}
future<> server::init(net::inet_address addr, std::optional<uint16_t> port, std::optional<uint16_t> https_port, std::optional<tls::credentials_builder> creds,
utils::updateable_value<bool> enforce_authorization, utils::updateable_value<bool> warn_authorization, utils::updateable_value<uint64_t> max_users_query_size_in_trace_output,
semaphore* memory_limiter, utils::updateable_value<uint32_t> max_concurrent_requests) {
_memory_limiter = memory_limiter;
_enforce_authorization = std::move(enforce_authorization);
_warn_authorization = std::move(warn_authorization);
_max_concurrent_requests = std::move(max_concurrent_requests);
_max_users_query_size_in_trace_output = std::move(max_users_query_size_in_trace_output);
if (!port && !https_port) {
return make_exception_future<>(std::runtime_error("Either regular port or TLS port"
" must be specified in order to init an alternator HTTP server instance"));
}
return seastar::async([this, addr, port, https_port, creds] {
_executor.start().get();
if (port) {
set_routes(_http_server._routes);
_http_server.set_content_streaming(true);
_http_server.listen(socket_address{addr, *port}).get();
_enabled_servers.push_back(std::ref(_http_server));
}
if (https_port) {
set_routes(_https_server._routes);
_https_server.set_content_streaming(true);
if (this_shard_id() == 0) {
_credentials = creds->build_reloadable_server_credentials([this](const tls::credentials_builder& b, const std::unordered_set<sstring>& files, std::exception_ptr ep) -> future<> {
if (ep) {
slogger.warn("Exception loading {}: {}", files, ep);
} else {
co_await container().invoke_on_others([&b](server& s) {
if (s._credentials) {
b.rebuild(*s._credentials);
}
});
slogger.info("Reloaded {}", files);
}
}).get();
} else {
_credentials = creds->build_server_credentials();
}
_https_server.listen(socket_address{addr, *https_port}, _credentials).get();
_enabled_servers.push_back(std::ref(_https_server));
}
});
}
future<> server::stop() {
return parallel_for_each(_enabled_servers, [] (http_server& server) {
return server.stop();
}).then([this] {
return _pending_requests.close();
}).then([this] {
return _json_parser.stop();
});
}
server::json_parser::json_parser() : _run_parse_json_thread(async([this] {
while (true) {
_document_waiting.wait().get();
if (_as.abort_requested()) {
return;
}
try {
_parsed_document = rjson::parse_yieldable(std::move(_raw_document));
_current_exception = nullptr;
} catch (...) {
_current_exception = std::current_exception();
}
_document_parsed.signal();
}
})) {
}
future<rjson::value> server::json_parser::parse(chunked_content&& content) {
if (content.size() < yieldable_parsing_threshold) {
return make_ready_future<rjson::value>(rjson::parse(std::move(content)));
}
return with_semaphore(_parsing_sem, 1, [this, content = std::move(content)] () mutable {
_raw_document = std::move(content);
_document_waiting.signal();
return _document_parsed.wait().then([this] {
if (_current_exception) {
return make_exception_future<rjson::value>(_current_exception);
}
return make_ready_future<rjson::value>(std::move(_parsed_document));
});
});
}
future<> server::json_parser::stop() {
_as.request_abort();
_document_waiting.signal();
_document_parsed.broken();
return std::move(_run_parse_json_thread);
}
// Convert an entry in the server's list of ongoing Alternator requests
// (_ongoing_requests) into a client_data object. This client_data object
// will then be used to produce a row for the "system.clients" virtual table.
client_data server::ongoing_request::make_client_data() const {
client_data cd;
cd.ct = client_type::alternator;
cd.ip = _client_address.addr();
cd.port = _client_address.port();
cd.shard_id = this_shard_id();
cd.connection_stage = client_connection_stage::established;
cd.username = _username;
cd.scheduling_group_name = _scheduling_group.name();
cd.ssl_enabled = _is_https;
// For now, we save the full User-Agent header as the "driver name"
// and keep "driver_version" unset.
cd.driver_name = _user_agent;
// Leave "protocol_version" unset, it has no meaning in Alternator.
// Leave "hostname", "ssl_protocol" and "ssl_cipher_suite" unset.
// As reported in issue #9216, we never set these fields in CQL
// either (see cql_server::connection::make_client_data()).
return cd;
}
future<utils::chunked_vector<foreign_ptr<std::unique_ptr<client_data>>>> server::get_client_data() {
utils::chunked_vector<foreign_ptr<std::unique_ptr<client_data>>> ret;
co_await _ongoing_requests.for_each_gently([&ret] (const ongoing_request& r) {
ret.emplace_back(make_foreign(std::make_unique<client_data>(r.make_client_data())));
});
co_return ret;
}
const char* api_error::what() const noexcept {
if (_what_string.empty()) {
_what_string = fmt::format("{} {}: {}", std::to_underlying(_http_code), _type, _msg);
}
return _what_string.c_str();
}
}