Merge branch 'master' into disable-edns-do

daemon/worker.c

@@ -66,6 +66,7 @@
 #include "util/data/msgencode.h"
 #include "util/data/dname.h"
 #include "util/fptr_wlist.h"
+#include "util/proxy_protocol.h"
 #include "util/tube.h"
 #include "util/edns.h"
 #include "util/timeval_func.h"
@@ -2317,6 +2318,7 @@ worker_init(struct worker* worker, struct config_file *cfg,
 			worker->env.cfg->stat_interval);
 		worker_restart_timer(worker);
 	}
+	pp_init(&sldns_write_uint16, &sldns_write_uint32);
 	return 1;
 }
 

doc/Changelog

@@ -1,3 +1,9 @@
+3 October 2023: George
+	- Merge #881: Generalise the proxy protocol code.
+
+2 October 2023: George
+	- Fix misplaced comment.
+
 22 September 2023: Wouter
 	- Fix #942: 1.18.0 libunbound DNS regression when built without
 	  OpenSSL.

libunbound/libworker.c

@@ -62,6 +62,7 @@
 #include "util/random.h"
 #include "util/config_file.h"
 #include "util/netevent.h"
+#include "util/proxy_protocol.h"
 #include "util/storage/lookup3.h"
 #include "util/storage/slabhash.h"
 #include "util/net_help.h"
@@ -265,6 +266,7 @@ libworker_setup(struct ub_ctx* ctx, int is_bg, struct ub_event_base* eb)
 	w->env->kill_sub = &mesh_state_delete;
 	w->env->detect_cycle = &mesh_detect_cycle;
 	comm_base_timept(w->base, &w->env->now, &w->env->now_tv);
+	pp_init(&sldns_write_uint16, &sldns_write_uint32);
 	return w;
 }
 

services/outside_network.c

@@ -550,7 +550,6 @@ reuse_tcp_find(struct outside_network* outnet, struct sockaddr_storage* addr,
 		log_assert(&key_p.reuse != (struct reuse_tcp*)result);
 		log_assert(&key_p != ((struct reuse_tcp*)result)->pending);
 	}
-	/* not found, return null */
 
 	/* It is possible that we search for something before the first element
 	 * in the tree. Replace a null pointer with the first element.
@@ -560,6 +559,7 @@ reuse_tcp_find(struct outside_network* outnet, struct sockaddr_storage* addr,
 		result = rbtree_first(&outnet->tcp_reuse);
 	}
 
+	/* not found, return null */
 	if(!result || result == RBTREE_NULL)
 		return NULL;
 

testcode/streamtcp.1

@@ -61,6 +61,17 @@ Specify the server to send the queries to. If not specified localhost (127.0.0.1
 .B \-d \fIsecs
 Delay after the connection before sending query.  This tests the timeout
 on the other side, eg. if shorter the connection is closed.
+.TP
+.B \-p \fIclient
+Use proxy protocol to send the query. Specify the ipaddr@portnr of the client
+to include in PROXYv2.
+.TP
+.B IXFR=serial
+Pass the type of the query as IXFR=N to send an IXFR query with serial N.
+.TP
+.B NOTIFY[=serial]
+Pass the type of the query as NOTIFY[=N] to send a notify packet. The serial N
+of the new zone can be included.
 .SH "EXAMPLES"
 .LP
 Some examples of use.

testcode/streamtcp.c

@@ -79,6 +79,8 @@ static void usage(char* argv[])
 	printf("-d secs		delay after connection before sending query\n");
 	printf("-s		use ssl\n");
 	printf("-h 		this help text\n");
+	printf("IXFR=N 		for the type, sends ixfr query with serial N.\n");
+	printf("NOTIFY[=N] 	for the type, sends notify. Can set new zone serial N.\n");
 	exit(1);
 }
 
@@ -115,6 +117,29 @@ open_svr(const char* svr, int udp, struct sockaddr_storage* addr,
 	return fd;
 }
 
+/** Append a SOA record with serial number */
+static void
+write_soa_serial_to_buf(sldns_buffer* buf, struct query_info* qinfo,
+	uint32_t serial)
+{
+	sldns_buffer_set_position(buf, sldns_buffer_limit(buf));
+	sldns_buffer_set_limit(buf, sldns_buffer_capacity(buf));
+	/* Write compressed reference to the query */
+	sldns_buffer_write_u16(buf, PTR_CREATE(LDNS_HEADER_SIZE));
+	sldns_buffer_write_u16(buf, LDNS_RR_TYPE_SOA);
+	sldns_buffer_write_u16(buf, qinfo->qclass);
+	sldns_buffer_write_u32(buf, 3600); /* TTL */
+	sldns_buffer_write_u16(buf, 1+1+4*5); /* rdatalen */
+	sldns_buffer_write_u8(buf, 0); /* primary "." */
+	sldns_buffer_write_u8(buf, 0); /* email "." */
+	sldns_buffer_write_u32(buf, serial); /* serial */
+	sldns_buffer_write_u32(buf, 0); /* refresh */
+	sldns_buffer_write_u32(buf, 0); /* retry */
+	sldns_buffer_write_u32(buf, 0); /* expire */
+	sldns_buffer_write_u32(buf, 0); /* minimum */
+	sldns_buffer_flip(buf);
+}
+
 /** write a query over the TCP fd */
 static void
 write_q(int fd, int udp, SSL* ssl, sldns_buffer* buf, uint16_t id,
@@ -123,6 +148,8 @@ write_q(int fd, int udp, SSL* ssl, sldns_buffer* buf, uint16_t id,
 {
 	struct query_info qinfo;
 	size_t proxy_buf_limit = sldns_buffer_limit(proxy_buf);
+	int have_serial = 0, is_notify = 0;
+	uint32_t serial = 0;
 	/* qname */
 	qinfo.qname = sldns_str2wire_dname(strname, &qinfo.qname_len);
 	if(!qinfo.qname) {
@@ -130,12 +157,27 @@ write_q(int fd, int udp, SSL* ssl, sldns_buffer* buf, uint16_t id,
 		exit(1);
 	}
 
-	/* qtype and qclass */
-	qinfo.qtype = sldns_get_rr_type_by_name(strtype);
-	if(qinfo.qtype == 0 && strcmp(strtype, "TYPE0") != 0) {
-		printf("cannot parse query type: '%s'\n", strtype);
-		exit(1);
+	/* qtype */
+	if(strncasecmp(strtype, "IXFR=", 5) == 0) {
+		serial = (uint32_t)atoi(strtype+5);
+		have_serial = 1;
+		qinfo.qtype = LDNS_RR_TYPE_IXFR;
+	} else if(strcasecmp(strtype, "NOTIFY") == 0) {
+		is_notify = 1;
+		qinfo.qtype = LDNS_RR_TYPE_SOA;
+	} else if(strncasecmp(strtype, "NOTIFY=", 7) == 0) {
+		serial = (uint32_t)atoi(strtype+7);
+		have_serial = 1;
+		is_notify = 1;
+		qinfo.qtype = LDNS_RR_TYPE_SOA;
+	} else {
+		qinfo.qtype = sldns_get_rr_type_by_name(strtype);
+		if(qinfo.qtype == 0 && strcmp(strtype, "TYPE0") != 0) {
+			printf("cannot parse query type: '%s'\n", strtype);
+			exit(1);
+		}
 	}
+	/* qclass */
 	qinfo.qclass = sldns_get_rr_class_by_name(strclass);
 	if(qinfo.qclass == 0 && strcmp(strclass, "CLASS0") != 0) {
 		printf("cannot parse query class: '%s'\n", strclass);
@@ -150,6 +192,21 @@ write_q(int fd, int udp, SSL* ssl, sldns_buffer* buf, uint16_t id,
 	sldns_buffer_write_u16_at(buf, 0, id);
 	sldns_buffer_write_u16_at(buf, 2, BIT_RD);
 
+	if(have_serial && qinfo.qtype == LDNS_RR_TYPE_IXFR) {
+		/* Attach serial to SOA record in the authority section. */
+		write_soa_serial_to_buf(buf, &qinfo, serial);
+		LDNS_NSCOUNT_SET(sldns_buffer_begin(buf), 1);
+	}
+	if(is_notify) {
+		LDNS_OPCODE_SET(sldns_buffer_begin(buf), LDNS_PACKET_NOTIFY);
+		LDNS_RD_CLR(sldns_buffer_begin(buf));
+		LDNS_AA_SET(sldns_buffer_begin(buf));
+		if(have_serial) {
+			write_soa_serial_to_buf(buf, &qinfo, serial);
+			LDNS_ANCOUNT_SET(sldns_buffer_begin(buf), 1);
+		}
+	}
+
 	if(1) {
 		/* add EDNS DO */
 		struct edns_data edns;
@@ -361,6 +418,7 @@ static int parse_pp2_client(const char* pp2_client, int udp,
 	sldns_buffer* proxy_buf)
 {
 	struct sockaddr_storage pp2_addr;
+	size_t bytes_written;
 	socklen_t pp2_addrlen = 0;
 	memset(&pp2_addr, 0, sizeof(pp2_addr));
 	if(*pp2_client == 0) return 0;
@@ -369,7 +427,9 @@ static int parse_pp2_client(const char* pp2_client, int udp,
 		exit(1);
 	}
 	sldns_buffer_clear(proxy_buf);
-	pp2_write_to_buf(proxy_buf, &pp2_addr, !udp);
+	bytes_written = pp2_write_to_buf(sldns_buffer_begin(proxy_buf),
+		sldns_buffer_remaining(proxy_buf), &pp2_addr, !udp);
+	sldns_buffer_set_position(proxy_buf, bytes_written);
 	sldns_buffer_flip(proxy_buf);
 	return 1;
 }
@@ -541,6 +601,8 @@ int main(int argc, char** argv)
 				break;
 			case 'p':
 				pp2_client = optarg;
+				pp_init(&sldns_write_uint16,
+					&sldns_write_uint32);
 				break;
 			case 'a':
 				onarrival = 1;

testdata/root_zonemd.tdir/root_zonemd.conf

@@ -0,0 +1,34 @@
+server:
+	verbosity: 7
+	# num-threads: 1
+	interface: 127.0.0.1
+	port: @PORT@
+	use-syslog: no
+	directory: ""
+	pidfile: "unbound.pid"
+	chroot: ""
+	username: ""
+	do-not-query-localhost: no
+	# for the test, so that DNSSEC verification works.
+	#val-override-date: 20230929090000
+	trust-anchor: ". DS 20326 8 2 E06D44B80B8F1D39A95C0B0D7C65D08458E880409BBC683457104237C7F8EC8D"
+
+remote-control:
+	control-enable: yes
+	control-interface: @CONTROL_PATH@/controlpipe.@CONTROL_PID@
+	control-use-cert: no
+
+# for the test, an upstream server in the test setup.
+stub-zone:
+	name: "."
+	stub-addr: 127.0.0.1@@TOPORT@
+
+# hyperlocal root zone
+auth-zone:
+	name: "."
+	fallback-enabled: yes
+	for-downstream: no
+	for-upstream: yes
+	zonefile: "root.zone"
+	zonemd-check: yes
+	zonemd-reject-absence: yes

testdata/root_zonemd.tdir/root_zonemd.dsc

@@ -0,0 +1,16 @@
+BaseName: root_zonemd
+Version: 1.0
+Description: ZONEMD check for root zone
+CreationDate: Fri 29 Sep 09:00:00 CEST 2023
+Maintainer: dr. W.C.A. Wijngaards
+Category: 
+Component:
+CmdDepends: 
+Depends: 
+Help:
+Pre: root_zonemd.pre
+Post: root_zonemd.post
+Test: root_zonemd.test
+AuxFiles: 
+Passed:
+Failure:

testdata/root_zonemd.tdir/root_zonemd.post

@@ -0,0 +1,14 @@
+# #-- root_zonemd.post --#
+# source the master var file when it's there
+[ -f ../.tpkg.var.master ] && source ../.tpkg.var.master
+# source the test var file when it's there
+[ -f .tpkg.var.test ] && source .tpkg.var.test
+#
+# do your teardown here
+. ../common.sh
+echo "> cat logfiles"
+cat fwd.log 
+cat unbound.log
+kill_pid $FWD_PID
+kill_pid $UNBOUND_PID
+rm -f $CONTROL_PATH/controlpipe.$CONTROL_PID

testdata/root_zonemd.tdir/root_zonemd.pre

@@ -0,0 +1,50 @@
+# #-- root_zonemd.pre--#
+# source the master var file when it's there
+[ -f ../.tpkg.var.master ] && source ../.tpkg.var.master
+# use .tpkg.var.test for in test variable passing
+[ -f .tpkg.var.test ] && source .tpkg.var.test
+
+. ../common.sh
+
+# attempt to download the root zone
+from=k.root-servers.net
+dig @$from . AXFR > root.txt
+if test $? -ne 0; then
+	echo "could not fetch root zone"
+	skip_test "could not fetch root zone"
+fi
+grep "	SOA	" root.txt | head -1 > root.soa
+cat root.soa >> root.zone
+grep -v "	SOA	" root.txt >> root.zone
+echo "fetched root.zone"
+ls -l root.zone
+cat root.soa
+
+get_random_port 2
+UNBOUND_PORT=$RND_PORT
+FWD_PORT=$(($RND_PORT + 1))
+echo "UNBOUND_PORT=$UNBOUND_PORT" >> .tpkg.var.test
+echo "FWD_PORT=$FWD_PORT" >> .tpkg.var.test
+
+# start forwarder
+get_ldns_testns
+$LDNS_TESTNS -p $FWD_PORT root_zonemd.testns >fwd.log 2>&1 &
+FWD_PID=$!
+echo "FWD_PID=$FWD_PID" >> .tpkg.var.test
+
+# make config file
+CONTROL_PATH=/tmp
+CONTROL_PID=$$
+sed -e 's/@PORT\@/'$UNBOUND_PORT'/' -e 's/@TOPORT\@/'$FWD_PORT'/' -e 's?@CONTROL_PATH\@?'$CONTROL_PATH'?' -e 's/@CONTROL_PID@/'$CONTROL_PID'/' < root_zonemd.conf > ub.conf
+# start unbound in the background
+PRE="../.."
+$PRE/unbound -d -c ub.conf >unbound.log 2>&1 &
+UNBOUND_PID=$!
+echo "UNBOUND_PID=$UNBOUND_PID" >> .tpkg.var.test
+echo "CONTROL_PATH=$CONTROL_PATH" >> .tpkg.var.test
+echo "CONTROL_PID=$CONTROL_PID" >> .tpkg.var.test
+
+cat .tpkg.var.test
+wait_ldns_testns_up fwd.log
+wait_unbound_up unbound.log
+

testdata/root_zonemd.tdir/root_zonemd.test

@@ -0,0 +1,51 @@
+# #-- root_zonemd.test --#
+# source the master var file when it's there
+[ -f ../.tpkg.var.master ] && source ../.tpkg.var.master
+# use .tpkg.var.test for in test variable passing
+[ -f .tpkg.var.test ] && source .tpkg.var.test
+
+PRE="../.."
+# do the test
+echo "> dig www.example.com."
+dig @localhost -p $UNBOUND_PORT . SOA | tee outfile
+echo "> check answer"
+if grep root-servers outfile | grep "nstld.verisign-grs.com"; then
+	echo "OK"
+else
+	echo "Not OK"
+	exit 1
+fi
+
+echo "> unbound-control status"
+$PRE/unbound-control -c ub.conf status
+if test $? -ne 0; then
+	echo "wrong exit value."
+	exit 1
+else
+	echo "exit value: OK"
+fi
+
+# This is the output when an unsupported algorithm is used.
+if grep "auth zone . ZONEMD unsupported algorithm" unbound.log; then
+	echo "OK"
+else
+	echo "ZONEMD verification not OK"
+	exit 1
+fi
+
+echo "> unbound-control auth_zone_reload ."
+$PRE/unbound-control -c ub.conf auth_zone_reload . 2>&1 | tee outfile
+if test $? -ne 0; then
+	echo "wrong exit value."
+	exit 1
+fi
+# The output of the reload can be checked.
+#echo "> check unbound-control output"
+#if grep "example.com: ZONEMD verification successful" outfile; then
+	#echo "OK"
+#else
+	#echo "Not OK"
+	#exit 1
+#fi
+
+exit 0

testdata/root_zonemd.tdir/root_zonemd.testns

@@ -0,0 +1,9 @@
+# reply to everything
+ENTRY_BEGIN
+MATCH opcode
+ADJUST copy_id copy_query
+REPLY QR SERVFAIL
+SECTION QUESTION
+example.com. IN SOA
+SECTION ANSWER
+ENTRY_END

util/netevent.c

@@ -892,15 +892,18 @@ static int udp_recv_needs_log(int err)
 static int consume_pp2_header(struct sldns_buffer* buf, struct comm_reply* rep,
 	int stream) {
 	size_t size;
-	struct pp2_header *header = pp2_read_header(buf);
-	if(header == NULL) return 0;
+	struct pp2_header *header;
+	int err = pp2_read_header(sldns_buffer_begin(buf),
+		sldns_buffer_remaining(buf));
+	if(err) return 0;
+	header = (struct pp2_header*)sldns_buffer_begin(buf);
 	size = PP2_HEADER_SIZE + ntohs(header->len);
 	if((header->ver_cmd & 0xF) == PP2_CMD_LOCAL) {
 		/* A connection from the proxy itself.
 		 * No need to do anything with addresses. */
 		goto done;
 	}
-	if(header->fam_prot == 0x00) {
+	if(header->fam_prot == PP2_UNSPEC_UNSPEC) {
 		/* Unspecified family and protocol. This could be used for
 		 * health checks by proxies.
 		 * No need to do anything with addresses. */
@@ -908,8 +911,8 @@ static int consume_pp2_header(struct sldns_buffer* buf, struct comm_reply* rep,
 	}
 	/* Read the proxied address */
 	switch(header->fam_prot) {
-		case 0x11: /* AF_INET|STREAM */
-		case 0x12: /* AF_INET|DGRAM */
+		case PP2_INET_STREAM:
+		case PP2_INET_DGRAM:
 			{
 			struct sockaddr_in* addr =
 				(struct sockaddr_in*)&rep->client_addr;
@@ -920,8 +923,8 @@ static int consume_pp2_header(struct sldns_buffer* buf, struct comm_reply* rep,
 			}
 			/* Ignore the destination address; it should be us. */
 			break;
-		case 0x21: /* AF_INET6|STREAM */
-		case 0x22: /* AF_INET6|DGRAM */
+		case PP2_INET6_STREAM:
+		case PP2_INET6_DGRAM:
 			{
 			struct sockaddr_in6* addr =
 				(struct sockaddr_in6*)&rep->client_addr;
@@ -934,6 +937,10 @@ static int consume_pp2_header(struct sldns_buffer* buf, struct comm_reply* rep,
 			}
 			/* Ignore the destination address; it should be us. */
 			break;
+		default:
+			log_err("proxy_protocol: unsupported family and "
+				"protocol 0x%x", (int)header->fam_prot);
+			return 0;
 	}
 	rep->is_proxied = 1;
 done:
@@ -1813,19 +1820,25 @@ ssl_handle_read(struct comm_point* c)
 					return 0;
 				}
 				c->tcp_byte_count += r;
+				sldns_buffer_skip(c->buffer, r);
 				if(c->tcp_byte_count != current_read_size) return 1;
 				c->pp2_header_state = pp2_header_init;
 			}
 		}
 		if(c->pp2_header_state == pp2_header_init) {
-			header = pp2_read_header(c->buffer);
-			if(!header) {
+			int err;
+			err = pp2_read_header(
+				sldns_buffer_begin(c->buffer),
+				sldns_buffer_limit(c->buffer));
+			if(err) {
 				log_err("proxy_protocol: could not parse "
-					"PROXYv2 header");
+					"PROXYv2 header (%s)",
+					pp_lookup_error(err));
 				return 0;
 			}
+			header = (struct pp2_header*)sldns_buffer_begin(c->buffer);
 			want_read_size = ntohs(header->len);
-			if(sldns_buffer_remaining(c->buffer) <
+			if(sldns_buffer_limit(c->buffer) <
 				PP2_HEADER_SIZE + want_read_size) {
 				log_err_addr("proxy_protocol: not enough "
 					"buffer size to read PROXYv2 header", "",
@@ -1874,6 +1887,7 @@ ssl_handle_read(struct comm_point* c)
 					return 0;
 				}
 				c->tcp_byte_count += r;
+				sldns_buffer_skip(c->buffer, r);
 				if(c->tcp_byte_count != current_read_size) return 1;
 				c->pp2_header_state = pp2_header_done;
 			}
@@ -1884,6 +1898,7 @@ ssl_handle_read(struct comm_point* c)
 				c->repinfo.remote_addrlen);
 			return 0;
 		}
+		sldns_buffer_flip(c->buffer);
 		if(!consume_pp2_header(c->buffer, &c->repinfo, 1)) {
 			log_err_addr("proxy_protocol: could not consume "
 				"PROXYv2 header", "", &c->repinfo.remote_addr,
@@ -2205,19 +2220,25 @@ comm_point_tcp_handle_read(int fd, struct comm_point* c, int short_ok)
 					goto recv_error_initial;
 				}
 				c->tcp_byte_count += r;
+				sldns_buffer_skip(c->buffer, r);
 				if(c->tcp_byte_count != current_read_size) return 1;
 				c->pp2_header_state = pp2_header_init;
 			}
 		}
 		if(c->pp2_header_state == pp2_header_init) {
-			header = pp2_read_header(c->buffer);
-			if(!header) {
+			int err;
+			err = pp2_read_header(
+				sldns_buffer_begin(c->buffer),
+				sldns_buffer_limit(c->buffer));
+			if(err) {
 				log_err("proxy_protocol: could not parse "
-					"PROXYv2 header");
+					"PROXYv2 header (%s)",
+					pp_lookup_error(err));
 				return 0;
 			}
+			header = (struct pp2_header*)sldns_buffer_begin(c->buffer);
 			want_read_size = ntohs(header->len);
-			if(sldns_buffer_remaining(c->buffer) <
+			if(sldns_buffer_limit(c->buffer) <
 				PP2_HEADER_SIZE + want_read_size) {
 				log_err_addr("proxy_protocol: not enough "
 					"buffer size to read PROXYv2 header", "",
@@ -2244,6 +2265,7 @@ comm_point_tcp_handle_read(int fd, struct comm_point* c, int short_ok)
 					goto recv_error;
 				}
 				c->tcp_byte_count += r;
+				sldns_buffer_skip(c->buffer, r);
 				if(c->tcp_byte_count != current_read_size) return 1;
 				c->pp2_header_state = pp2_header_done;
 			}
@@ -2254,6 +2276,7 @@ comm_point_tcp_handle_read(int fd, struct comm_point* c, int short_ok)
 				c->repinfo.remote_addrlen);
 			return 0;
 		}
+		sldns_buffer_flip(c->buffer);
 		if(!consume_pp2_header(c->buffer, &c->repinfo, 1)) {
 			log_err_addr("proxy_protocol: could not consume "
 				"PROXYv2 header", "", &c->repinfo.remote_addr,

util/proxy_protocol.c

@@ -38,102 +38,162 @@
  *
  * This file contains PROXY protocol functions.
  */
-#include "config.h"
-#include "util/log.h"
 #include "util/proxy_protocol.h"
 
-int
-pp2_write_to_buf(struct sldns_buffer* buf, struct sockaddr_storage* src,
+/**
+ * Internal struct initialized with function pointers for writing uint16 and
+ * uint32.
+ */
+struct proxy_protocol_data {
+	void (*write_uint16)(void* buf, uint16_t data);
+	void (*write_uint32)(void* buf, uint32_t data);
+};
+struct proxy_protocol_data pp_data;
+
+/**
+ * Internal lookup table; could be further generic like sldns_lookup_table
+ * for all the future generic stuff.
+ */
+struct proxy_protocol_lookup_table {
+	int id;
+	const char *text;
+};
+
+/**
+ * Internal parsing error text; could be exposed with pp_lookup_error.
+ */
+static struct proxy_protocol_lookup_table pp_parse_errors_data[] = {
+	{ PP_PARSE_NOERROR, "no parse error" },
+	{ PP_PARSE_SIZE, "not enough space for header" },
+	{ PP_PARSE_WRONG_HEADERv2, "could not match PROXYv2 header" },
+	{ PP_PARSE_UNKNOWN_CMD, "unknown command" },
+	{ PP_PARSE_UNKNOWN_FAM_PROT, "unknown family and protocol" },
+};
+
+void
+pp_init(void (*write_uint16)(void* buf, uint16_t data),
+	void (*write_uint32)(void* buf, uint32_t data)) {
+	pp_data.write_uint16 = write_uint16;
+	pp_data.write_uint32 = write_uint32;
+}
+
+const char*
+pp_lookup_error(enum pp_parse_errors error) {
+	return pp_parse_errors_data[error].text;
+}
+
+size_t
+pp2_write_to_buf(uint8_t* buf, size_t buflen,
+#ifdef INET6
+	struct sockaddr_storage* src,
+#else
+	struct sockaddr_in* src,
+#endif
 	int stream)
 {
 	int af;
+	size_t expected_size;
 	if(!src) return 0;
 	af = (int)((struct sockaddr_in*)src)->sin_family;
-	if(sldns_buffer_remaining(buf) <
-		PP2_HEADER_SIZE + (af==AF_INET?12:36)) {
+	expected_size = PP2_HEADER_SIZE + (af==AF_INET?12:36);
+	if(buflen < expected_size) {
 		return 0;
 	}
 	/* sig */
-	sldns_buffer_write(buf, PP2_SIG, PP2_SIG_LEN);
+	memcpy(buf, PP2_SIG, PP2_SIG_LEN);
+	buf += PP2_SIG_LEN;
 	/* version and command */
-	sldns_buffer_write_u8(buf, (PP2_VERSION << 4) | PP2_CMD_PROXY);
-	if(af==AF_INET) {
+	*buf = (PP2_VERSION << 4) | PP2_CMD_PROXY;
+	buf++;
+	switch(af) {
+	case AF_INET:
 		/* family and protocol */
-		sldns_buffer_write_u8(buf,
-			(PP2_AF_INET<<4) |
-			(stream?PP2_PROT_STREAM:PP2_PROT_DGRAM));
+		*buf = (PP2_AF_INET<<4) |
+			(stream?PP2_PROT_STREAM:PP2_PROT_DGRAM);
+		buf++;
 		/* length */
-		sldns_buffer_write_u16(buf, 12);
+		(*pp_data.write_uint16)(buf, 12);
+		buf += 2;
 		/* src addr */
-		sldns_buffer_write(buf,
+		memcpy(buf,
 			&((struct sockaddr_in*)src)->sin_addr.s_addr, 4);
+		buf += 4;
 		/* dst addr */
-		sldns_buffer_write_u32(buf, 0);
+		(*pp_data.write_uint32)(buf, 0);
+		buf += 4;
 		/* src port */
-		sldns_buffer_write(buf,
+		memcpy(buf,
 			&((struct sockaddr_in*)src)->sin_port, 2);
-		/* dst port */
-		sldns_buffer_write_u16(buf, 0);
-	} else {
-		/* family and protocol */
-		sldns_buffer_write_u8(buf,
-			(PP2_AF_INET6<<4) |
-			(stream?PP2_PROT_STREAM:PP2_PROT_DGRAM));
-		/* length */
-		sldns_buffer_write_u16(buf, 36);
-		/* src addr */
-		sldns_buffer_write(buf,
-			&((struct sockaddr_in6*)src)->sin6_addr, 16);
+		buf += 2;
 		/* dst addr */
-		sldns_buffer_set_at(buf,
-			sldns_buffer_position(buf), 0, 16);
-		sldns_buffer_skip(buf, 16);
-		/* src port */
-		sldns_buffer_write(buf,
-			&((struct sockaddr_in6*)src)->sin6_port, 2);
 		/* dst port */
-		sldns_buffer_write_u16(buf, 0);
+		(*pp_data.write_uint16)(buf, 12);
+		break;
+#ifdef INET6
+	case AF_INET6:
+		/* family and protocol */
+		*buf = (PP2_AF_INET6<<4) |
+			(stream?PP2_PROT_STREAM:PP2_PROT_DGRAM);
+		buf++;
+		/* length */
+		(*pp_data.write_uint16)(buf, 36);
+		buf += 2;
+		/* src addr */
+		memcpy(buf,
+			&((struct sockaddr_in6*)src)->sin6_addr, 16);
+		buf += 16;
+		/* dst addr */
+		memset(buf, 0, 16);
+		buf += 16;
+		/* src port */
+		memcpy(buf, &((struct sockaddr_in6*)src)->sin6_port, 2);
+		buf += 2;
+		/* dst port */
+		(*pp_data.write_uint16)(buf, 0);
+		break;
+#endif /* INET6 */
+	case AF_UNIX:
+		/* fallthrough */
+	default:
+		return 0;
 	}
-	return 1;
+	return expected_size;
 }
 
-struct pp2_header*
-pp2_read_header(struct sldns_buffer* buf)
+int
+pp2_read_header(uint8_t* buf, size_t buflen)
 {
 	size_t size;
-	struct pp2_header* header = (struct pp2_header*)sldns_buffer_begin(buf);
+	struct pp2_header* header = (struct pp2_header*)buf;
 	/* Try to fail all the unsupported cases first. */
-	if(sldns_buffer_remaining(buf) < PP2_HEADER_SIZE) {
-		log_err("proxy_protocol: not enough space for header");
-		return NULL;
+	if(buflen < PP2_HEADER_SIZE) {
+		return PP_PARSE_SIZE;
 	}
 	/* Check for PROXYv2 header */
 	if(memcmp(header, PP2_SIG, PP2_SIG_LEN) != 0 ||
 		((header->ver_cmd & 0xF0)>>4) != PP2_VERSION) {
-		log_err("proxy_protocol: could not match PROXYv2 header");
-		return NULL;
+		return PP_PARSE_WRONG_HEADERv2;
 	}
 	/* Check the length */
 	size = PP2_HEADER_SIZE + ntohs(header->len);
-	if(sldns_buffer_remaining(buf) < size) {
-		log_err("proxy_protocol: not enough space for header");
-		return NULL;
+	if(buflen < size) {
+		return PP_PARSE_SIZE;
 	}
 	/* Check for supported commands */
 	if((header->ver_cmd & 0xF) != PP2_CMD_LOCAL &&
 		(header->ver_cmd & 0xF) != PP2_CMD_PROXY) {
-		log_err("proxy_protocol: unsupported command");
-		return NULL;
+		return PP_PARSE_UNKNOWN_CMD;
 	}
 	/* Check for supported family and protocol */
-	if(header->fam_prot != 0x00 /* AF_UNSPEC|UNSPEC */ &&
-		header->fam_prot != 0x11 /* AF_INET|STREAM */ &&
-		header->fam_prot != 0x12 /* AF_INET|DGRAM */ &&
-		header->fam_prot != 0x21 /* AF_INET6|STREAM */ &&
-		header->fam_prot != 0x22 /* AF_INET6|DGRAM */) {
-		log_err("proxy_protocol: unsupported family and protocol");
-		return NULL;
+	if(header->fam_prot != PP2_UNSPEC_UNSPEC &&
+		header->fam_prot != PP2_INET_STREAM &&
+		header->fam_prot != PP2_INET_DGRAM &&
+		header->fam_prot != PP2_INET6_STREAM &&
+		header->fam_prot != PP2_INET6_DGRAM &&
+		header->fam_prot != PP2_UNIX_STREAM &&
+		header->fam_prot != PP2_UNIX_DGRAM) {
+		return PP_PARSE_UNKNOWN_FAM_PROT;
 	}
 	/* We have a correct header */
-	return header;
+	return PP_PARSE_NOERROR;
 }

util/proxy_protocol.h

@@ -42,7 +42,7 @@
 #ifndef PROXY_PROTOCOL_H
 #define PROXY_PROTOCOL_H
 
-#include "sldns/sbuffer.h"
+#include "config.h"
 
 /** PROXYv2 minimum header size */
 #define PP2_HEADER_SIZE 16
@@ -51,11 +51,11 @@
 #define PP2_SIG "\x0D\x0A\x0D\x0A\x00\x0D\x0A\x51\x55\x49\x54\x0A"
 #define PP2_SIG_LEN 12
 
-/** PROXYv2 version */
+/** PROXYv2 version (protocol value) */
 #define PP2_VERSION 0x2
 
 /**
- * PROXYv2 command.
+ * PROXYv2 command (protocol value).
  */
 enum pp2_command {
 	PP2_CMD_LOCAL = 0x0,
@@ -63,7 +63,7 @@ enum pp2_command {
 };
 
 /**
- * PROXYv2 address family.
+ * PROXYv2 address family (protocol value).
  */
 enum pp2_af {
 	PP2_AF_UNSPEC = 0x0,
@@ -73,7 +73,7 @@ enum pp2_af {
 };
 
 /**
- * PROXYv2 protocol.
+ * PROXYv2 protocol (protocol value).
  */
 enum pp2_protocol {
 	PP2_PROT_UNSPEC = 0x0,
@@ -81,6 +81,19 @@ enum pp2_protocol {
 	PP2_PROT_DGRAM = 0x2
 };
 
+/**
+ * Expected combinations of address family and protocol values used in checks.
+ */
+enum pp2_af_protocol_combination {
+	PP2_UNSPEC_UNSPEC = (PP2_AF_UNSPEC<<4)|PP2_PROT_UNSPEC,
+	PP2_INET_STREAM = (PP2_AF_INET<<4)|PP2_PROT_STREAM,
+	PP2_INET_DGRAM = (PP2_AF_INET<<4)|PP2_PROT_DGRAM,
+	PP2_INET6_STREAM = (PP2_AF_INET6<<4)|PP2_PROT_STREAM,
+	PP2_INET6_DGRAM = (PP2_AF_INET6<<4)|PP2_PROT_DGRAM,
+	PP2_UNIX_STREAM = (PP2_AF_UNIX<<4)|PP2_PROT_STREAM,
+	PP2_UNIX_DGRAM = (PP2_AF_UNIX<<4)|PP2_PROT_DGRAM
+};
+
 /**
  * PROXYv2 header.
  */
@@ -109,23 +122,56 @@ struct pp2_header {
 	} addr;
 };
 
+/**
+ * PROXY parse errors.
+ */
+enum pp_parse_errors {
+	PP_PARSE_NOERROR = 0,
+	PP_PARSE_SIZE,
+	PP_PARSE_WRONG_HEADERv2,
+	PP_PARSE_UNKNOWN_CMD,
+	PP_PARSE_UNKNOWN_FAM_PROT,
+};
+
+/**
+ * Initialize the internal proxy structure.
+ * @param write_uint16: pointer to a function that can write uint16.
+ * @param write_uint32: pointer to a function that can write uint32.
+ */
+void pp_init(void (*write_uint16)(void* buf, uint16_t data),
+	void (*write_uint32)(void* buf, uint32_t data));
+
+/**
+ * Lookup the parsing error description.
+ * @param error: parsing error from pp2_read_header.
+ * @return the description.
+ */
+const char* pp_lookup_error(enum pp_parse_errors error);
+
 /**
  * Write a PROXYv2 header at the current position of the buffer.
- * @param buf: the buffer to write to.
+ * @param buf: pointer to the buffer to write data to.
+ * @param buflen: available size on the buffer.
  * @param src: the source address.
  * @param stream: if the protocol is stream or datagram.
  * @return 1 on success, 0 on failure.
  */
-int pp2_write_to_buf(struct sldns_buffer* buf, struct sockaddr_storage* src,
+size_t pp2_write_to_buf(uint8_t* buf, size_t buflen,
+#ifdef INET6
+	struct sockaddr_storage* src,
+#else
+	struct sockaddr_in* src,
+#endif
 	int stream);
 
 /**
  * Read a PROXYv2 header from the current position of the buffer.
  * It does initial validation and returns a pointer to the buffer position on
  * success.
- * @param buf: the buffer to read from.
- * @return the pointer to the buffer position on success, NULL on error.
+ * @param buf: pointer to the buffer data to read from.
+ * @param buflen: available size on the buffer.
+ * @return parsing error, 0 on success.
  */
-struct pp2_header* pp2_read_header(struct sldns_buffer* buf);
+int pp2_read_header(uint8_t* buf, size_t buflen);
 
 #endif /* PROXY_PROTOCOL_H */