- handle content-length of stomp in zypper plugin

Makefile.am

@@ -3,7 +3,7 @@
 #
 
 SUBDIRS = snapper dbus server client scripts pam data doc po examples		\
-	testsuite testsuite-real testsuite-cmp zypp-plugin
+	testsuite testsuite-real testsuite-cmp stomp zypp-plugin
 
 AUTOMAKE_OPTIONS = foreign dist-xz no-dist-gzip
 

configure.ac

@@ -231,6 +231,8 @@ AC_CONFIG_FILES([
 	testsuite/Makefile
 	testsuite-real/Makefile
 	testsuite-cmp/Makefile
+	stomp/Makefile
+	stomp/testsuite/Makefile
 	zypp-plugin/Makefile
 	zypp-plugin/testsuite/Makefile
 	package/snapper.spec:snapper.spec.in

package/snapper.changes

@@ -1,3 +1,9 @@
+-------------------------------------------------------------------
+Fri Jul 05 16:03:42 CEST 2024 - aschnell@suse.com
+
+- handle content-length of stomp in zypper plugin
+  (gh#openSUSE/snapper#918)
+
 -------------------------------------------------------------------
 Wed May 22 17:21:18 CEST 2024 - aschnell@suse.com
 

stomp/.gitignore

@@ -0,0 +1,2 @@
+*.lo
+*.la

stomp/Makefile.am

@@ -0,0 +1,10 @@
+#
+# Makefile.am for snapper/stomp
+#
+
+SUBDIRS = . testsuite
+
+noinst_LTLIBRARIES = libstomp.la
+
+libstomp_la_SOURCES = 	\
+	Stomp.h 	Stomp.cc

stomp/Stomp.cc

@@ -0,0 +1,216 @@
+/*
+ * Copyright (c) [2019-2024] SUSE LLC
+ *
+ * All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of version 2 of the GNU General Public License as published
+ * by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, contact SUSE LLC.
+ *
+ * To contact SUSE about this file by physical or electronic mail, you may
+ * find current contact information at www.suse.com.
+ */
+
+
+#include <iostream>
+#include <regex>
+
+
+using namespace std;
+
+
+#include "Stomp.h"
+
+
+namespace Stomp
+{
+
+    Message
+    read_message(istream& is)
+    {
+	static const regex rx_command("[A-Za-z0-9_]+", regex::extended);
+
+	enum class State { Start, Headers, Body } state = State::Start;
+	bool has_content_length = false;
+	ssize_t content_length = 0;
+
+	Message msg;
+
+	while (!is.eof())
+	{
+	    string line;
+	    getline(is, line);
+
+	    if (state == State::Start)
+	    {
+		if (is.eof())
+		    return msg; // empty
+
+		if (line.empty())
+		    continue;
+
+		if (regex_match(line, rx_command))
+		{
+		    msg = Message();
+		    msg.command = line;
+		    state = State::Headers;
+		}
+		else
+		{
+		    throw runtime_error("stomp error: expected a command, got '" + line + "'");
+		}
+	    }
+	    else if (state == State::Headers)
+	    {
+		if (line.empty())
+		{
+		    state = State::Body;
+
+		    if (has_content_length)
+		    {
+			if (content_length > 0)
+			{
+			    vector<char> buf(content_length);
+			    is.read(buf.data(), content_length);
+			    msg.body.assign(buf.data(), content_length);
+			}
+
+			// still read the \0 that terminates the frame
+			char buf2 = '-';
+			is.read(&buf2, 1);
+			if (buf2 != '\0')
+			    throw runtime_error("stomp error: missing \\0 at frame end");
+		    }
+		    else
+		    {
+			getline(is, msg.body, '\0');
+		    }
+
+		    return msg;
+		}
+		else
+		{
+		    string::size_type pos = line.find(':');
+		    if (pos == string::npos)
+			throw runtime_error("stomp error: expected a header or new line, got '" + line + "'");
+
+		    string key = unescape_header(line.substr(0, pos));
+		    string value = unescape_header(line.substr(pos + 1));
+
+		    if (key == "content-length")
+		    {
+			has_content_length = true;
+			content_length = std::stol(value.c_str());
+		    }
+
+		    msg.headers[key] = value;
+		}
+	    }
+	}
+
+	throw runtime_error("stomp error: expected a message, got a part of it");
+    }
+
+
+    void
+    write_message(ostream& os, const Message& msg)
+    {
+	os << msg.command << '\n';
+	for (auto it : msg.headers)
+	    os << escape_header(it.first) << ':' << escape_header(it.second) << '\n';
+	os << '\n';
+	os << msg.body << '\0';
+	os.flush();
+    }
+
+
+    Message
+    ack()
+    {
+	Message msg;
+	msg.command = "ACK";
+	return msg;
+    }
+
+
+    Message
+    nack()
+    {
+	Message msg;
+	msg.command = "NACK";
+	return msg;
+    }
+
+
+    std::string
+    escape_header(const std::string& in)
+    {
+	string out;
+
+	for (const char c : in)
+	{
+	    switch (c)
+	    {
+		case '\r':
+		    out += "\\r"; break;
+		case '\n':
+		    out += "\\n"; break;
+		case ':':
+		    out += "\\c"; break;
+		case '\\':
+		    out += "\\\\"; break;
+
+		default:
+		    out += c;
+	    }
+	}
+
+	return out;
+    }
+
+
+    std::string
+    unescape_header(const std::string& in)
+    {
+	string out;
+
+	for (string::const_iterator it = in.begin(); it != in.end(); ++it)
+	{
+	    if (*it == '\\')
+	    {
+		if (++it == in.end())
+		    throw runtime_error("stomp error: invalid start of escape sequence");
+
+		switch (*it)
+		{
+		    case 'r':
+			out += '\r'; break;
+		    case 'n':
+			out += '\n'; break;
+		    case 'c':
+			out += ':'; break;
+		    case '\\':
+			out += '\\'; break;
+
+		    default:
+			throw runtime_error("stomp error: unknown escape sequence");
+		}
+	    }
+	    else
+	    {
+		out += *it;
+	    }
+	}
+
+	return out;
+    }
+
+}

stomp/Stomp.h

@@ -0,0 +1,60 @@
+/*
+ * Copyright (c) [2019-2024] SUSE LLC
+ *
+ * All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of version 2 of the GNU General Public License as published
+ * by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, contact SUSE LLC.
+ *
+ * To contact SUSE about this file by physical or electronic mail, you may
+ * find current contact information at www.suse.com.
+ */
+
+
+#ifndef SNAPPER_STOMP_H
+#define SNAPPER_STOMP_H
+
+
+#include <istream>
+#include <ostream>
+#include <string>
+#include <map>
+
+
+/**
+ * A tiny STOMP (https://stomp.github.io/) implementation.
+ */
+
+namespace Stomp
+{
+
+    struct Message
+    {
+	std::string command;
+	std::map<std::string, std::string> headers;
+	std::string body;
+    };
+
+
+    Message read_message(std::istream& is);
+    void write_message(std::ostream& os, const Message& msg);
+
+    Message ack();
+    Message nack();
+
+    std::string escape_header(const std::string& in);
+    std::string unescape_header(const std::string& in);
+
+}
+
+
+#endif

stomp/testsuite/.gitignore

@@ -0,0 +1,5 @@
+*.log
+*.o
+*.test
+*.trs
+test-suite.log

stomp/testsuite/Makefile.am

@@ -0,0 +1,17 @@
+#
+# Makefile.am for snapper/stomp/testsuite
+#
+
+SUBDIRS = .
+
+LDADD =								\
+	../libstomp.la						\
+	-lboost_unit_test_framework
+
+check_PROGRAMS =						\
+	read1.test write1.test escape.test
+
+AM_DEFAULT_SOURCE_EXT = .cc
+
+TESTS = $(check_PROGRAMS)
+

stomp/testsuite/escape.cc

@@ -0,0 +1,29 @@
+
+#define BOOST_TEST_DYN_LINK
+#define BOOST_TEST_MODULE snapper
+
+#include <boost/test/unit_test.hpp>
+
+#include "../Stomp.h"
+
+
+using namespace std;
+using namespace Stomp;
+
+
+BOOST_AUTO_TEST_CASE(escape)
+{
+    BOOST_CHECK_EQUAL(Stomp::escape_header("hello"), "hello");
+
+    BOOST_CHECK_EQUAL(Stomp::escape_header("hello\nworld"), "hello\\nworld");
+    BOOST_CHECK_EQUAL(Stomp::escape_header("hello:world"), "hello\\cworld");
+}
+
+
+BOOST_AUTO_TEST_CASE(unescape)
+{
+    BOOST_CHECK_EQUAL(Stomp::unescape_header("hello"), "hello");
+
+    BOOST_CHECK_EQUAL(Stomp::unescape_header("hello\\nworld"), "hello\nworld");
+    BOOST_CHECK_EQUAL(Stomp::unescape_header("hello\\cworld"), "hello:world");
+}