9-patch_add-constraint-useragent.patch

From: Pekka Helenius <fincer89@hotmail.com>
Date: Tue, 04 Aug 2020 01:52:18 +0300
Subject: Add user agent string support for HTTPS constraints, update ChangeLog


--- a/src/parse.y	2020-08-03 23:22:43.401482642 +0300
+++ b/src/parse.y	2020-08-04 01:03:44.458183310 +0300
@@ -69,6 +69,7 @@ struct opts {
 	int		trusted;
 	char		*refstr;
 	int		port;
+	char	*useragent;
 	int		pos_num;
 	double		pos_decimal;
 } opts;
@@ -91,6 +92,7 @@ typedef struct {
 %token	SERVER SERVERS SENSOR CORRECTION RTABLE REFID STRATUM WEIGHT
 %token	ERROR
 %token	PORT
+%token	USERAGENT
 
 %token	_NTPD_USER
 %token	_DRIFTFILE
@@ -164,6 +166,7 @@ typedef struct {
 %type	<v.opts>		weight
 %type	<v.opts>		trusted
 %type	<v.opts>		port
+%type	<v.opts>		useragent
 
 %type	<v.opts>		pos_num
 %type	<v.opts>		pos_decimal
@@ -376,6 +379,8 @@ main		: LISTEN ON address listen_opts	{
 
 				p->addr_head.pool = ++poolseqnum;
 				p->addr_head.name = strdup($3->name);
+				if ($4.useragent)
+					p->useragent = strdup($4.useragent);
 				p->addr_head.path = strdup($3->path);
 				if (p->addr_head.name == NULL ||
 				    p->addr_head.path == NULL)
@@ -425,6 +430,8 @@ main		: LISTEN ON address listen_opts	{
 
 			p->addr_head.pool = 0;
 			p->addr_head.name = strdup($3->name);
+			if ($4.useragent)
+				p->useragent = strdup($4.useragent);
 			p->addr_head.path = strdup($3->path);
 			if (p->addr_head.name == NULL ||
 			    p->addr_head.path == NULL)
@@ -735,7 +742,7 @@ constraint_opts	:	{ opts_default(); }
 constraint_opts_l	: constraint_opts_l constraint_opt
 		| constraint_opt
 		;
-constraint_opt	: port
+constraint_opt	: port | useragent
 		;
 
 sensor_opts	:	{ opts_default(); }
@@ -803,6 +810,19 @@ port		: PORT NUMBER	{
 		}
 		;
 
+useragent		: USERAGENT STRING {
+			size_t l = strlen($2);
+
+			if (l < 1 || l > USERAGENT_MAX_LENGTH) {
+				yyerror("user agent string length must be from 1 to %d characters",
+				USERAGENT_MAX_LENGTH);
+				free($2);
+				YYERROR;
+			}
+			opts.useragent = $2;
+		}
+		;
+
 rtable		: RTABLE NUMBER {
 #ifdef RT_TABLEID_MAX
 			if ($2 < 0 || $2 > RT_TABLEID_MAX) {
@@ -924,6 +944,7 @@ lookup(char *s)
 		{ "trustlevel_badpeer",		_TRUSTLEVEL_BADPEER,	"single" },
 		{ "trustlevel_max",		_TRUSTLEVEL_MAX,	"single" },
 		{ "trustlevel_pathetic",		_TRUSTLEVEL_PATHETIC,	"single" },
+		{ "useragent",		USERAGENT,	"multiple" },
 		{ "weight",		WEIGHT,	"multiple" },
 	};
 	struct keywords	*p;
--- a/src/ntpd.h	2020-08-03 23:25:02.978705101 +0300
+++ b/src/ntpd.h	2020-08-03 23:41:03.644863921 +0300
@@ -114,6 +114,8 @@
 #define CONSTRAINT_CA	SYSCONFDIR "/ssl/cert.pem"
 #define CONSTRAINT_CA_VALIDATION			0x01;
 
+#define USERAGENT_MAX_LENGTH		256
+
 #define PARENT_SOCK_FILENO		CONSTRAINT_PASSFD
 
 #define NTP_PROC_NAME			"ntp_main"
@@ -159,9 +161,11 @@ struct ntp_addr_wrap {
 struct ntp_addr_msg {
 	struct ntp_addr		 a;
 	int		port;
-	size_t			 namelen;
-	size_t			 pathlen;
+	char		useragent[USERAGENT_MAX_LENGTH];
+	size_t			namelen;
+	size_t			pathlen;
 	size_t			portlen;
+	size_t			agentlen;
 };
 
 struct ntp_status {
@@ -239,6 +243,7 @@ struct constraint {
 	time_t				 last;
 	time_t				 constraint;
 	int				 dnstries;
+	char			*useragent;
 };
 
 struct ntp_conf_sensor {
@@ -495,6 +500,7 @@ struct httpsdate {
 	char			*tls_hostname;
 	char			*tls_path;
 	char			*tls_request;
+	char			*tls_useragent;
 	struct tls_config	*tls_config;
 	struct tls		*tls_ctx;
 	struct tm		 tls_tm;
@@ -502,11 +508,11 @@ struct httpsdate {
 
 struct httpsdate *
 	 httpsdate_init(const char *, const int *, const char *,
-	    const char *, const u_int8_t *, size_t);
+	    const char *, const char *, const u_int8_t *, size_t);
 void	 httpsdate_free(void *);
 int	 httpsdate_request(struct httpsdate *, struct timeval *);
 void	*httpsdate_query(const char *, const int *, const char *,
-	    const char *, const u_int8_t *, size_t,
+	    const char *, const char *, const u_int8_t *, size_t,
 	    struct timeval *, struct timeval *);
 
 char	*tls_readline(struct tls *, size_t *, size_t *, struct timeval *);
--- a/src/constraint.c	2020-08-02 01:58:28.366952848 +0300
+++ b/src/constraint.c	2020-08-03 23:43:48.584926017 +0300
@@ -132,7 +132,7 @@ constraint_query(struct constraint *cstr
 {
 	time_t			 now;
 	struct ntp_addr_msg	 am;
-	struct iovec		 iov[4];
+	struct iovec		 iov[5];
 	int			 iov_cnt = 0;
 
 	now = getmonotime();
@@ -185,6 +185,18 @@ constraint_query(struct constraint *cstr
 	memcpy(&am.a, cstr->addr, sizeof(am.a));
 	memcpy(&am.port, &cstr->addr_head.port, sizeof(am.port));
 
+	if (cstr->useragent)
+		memcpy(&am.useragent, cstr->useragent, USERAGENT_MAX_LENGTH);
+/*
+ * FIXME For some reason, dynamically allocating user agent string size does not seem to work
+ * Investigate, why usage of dynamic memory allocated data fails.
+ * 
+	if (cstr->useragent) {
+			if ((am.useragent = calloc(1, strlen(cstr->useragent)) ) == NULL)
+				fatal("constraint id %d: can't allocate memory for user agent string", cstr->id);
+			memcpy(am.useragent, cstr->useragent, strlen(cstr->useragent));
+	}
+*/
 	iov[iov_cnt].iov_base = &am;
 	iov[iov_cnt++].iov_len = sizeof(am);
 	if (cstr->addr_head.name) {
@@ -202,6 +214,11 @@ constraint_query(struct constraint *cstr
 		iov[iov_cnt].iov_base = &cstr->addr_head.port;
 		iov[iov_cnt++].iov_len = am.portlen;
 	}
+	if (cstr->useragent) {
+			am.agentlen = strlen(cstr->useragent) + 1;
+			iov[iov_cnt].iov_base = cstr->useragent;
+			iov[iov_cnt++].iov_len = am.agentlen;
+	}
 
 	imsg_composev(ibuf_main, IMSG_CONSTRAINT_QUERY,
 	    cstr->id, 0, -1, iov, iov_cnt);
@@ -228,8 +245,9 @@ priv_constraint_msg(u_int32_t id, u_int8
 		log_warnx("constraint id %d: longer query expected", id);
 		return;
 	}
+
 	memcpy(&am, data, sizeof(am));
-	if (len != (sizeof(am) + am.namelen + am.pathlen + am.portlen)) {
+	if (len != (sizeof(am) + am.namelen + am.pathlen + am.portlen + am.agentlen)) {
 		log_warnx("constraint id %d: invalid query received", id);
 		return;
 	}
@@ -238,6 +256,7 @@ priv_constraint_msg(u_int32_t id, u_int8
 	if ((h = calloc(1, sizeof(*h))) == NULL)
 		fatal("constraint id %d: can't allocate memory for network address", id);
 	memcpy(h, &am.a, sizeof(*h));
+
 	h->next = NULL;
 
 	cstr = new_constraint();
@@ -308,7 +327,7 @@ priv_constraint_readquery(struct constra
 		);
 
 	memcpy(am, imsg.data, sizeof(*am));
-	if (mlen != (sizeof(*am) + am->namelen + am->pathlen + am->portlen))
+	if (mlen != (sizeof(*am) + am->namelen + am->pathlen + am->portlen + am->agentlen))
 		fatalx("constraint: invalid message length received from parent process (%s)",
 			   __func__
 			  );
@@ -327,6 +346,8 @@ priv_constraint_readquery(struct constra
 	cstr->port = port;
 	cstr->addr_head.port = port;
 
+	cstr->useragent = strdup(am->useragent);
+
 	dptr = imsg.data;
 	memcpy(*data, dptr + sizeof(*am), mlen - sizeof(*am));
 	imsg_free(&imsg);
@@ -464,7 +485,7 @@ priv_constraint_child(const char *pw_dir
 		log_debug("constraint %s: initializing HTTPS request", addr);
 		if ((ctx = httpsdate_query(addr,
 			&cstr.addr_head.port, cstr.addr_head.name, cstr.addr_head.path,
-			conf->ca, conf->ca_len, &rectv, &xmttv)) == NULL) {
+			cstr.useragent, conf->ca, conf->ca_len, &rectv, &xmttv)) == NULL) {
 			log_debug("constraint %s: failed to get proper time results", addr); 
 			/* Abort with failure but without warning */
 			exit(1);
@@ -852,6 +873,9 @@ constraint_msg_dns(u_int32_t id, u_int8_
 			ncstr->addr_head.name = strdup(cstr->addr_head.name);
 			ncstr->addr_head.path = strdup(cstr->addr_head.path);
 			ncstr->addr_head.port = intdup(cstr->addr_head.port);
+			
+			if (cstr->useragent)
+				ncstr->useragent = strdup(cstr->useragent);
 
 			// Unless we do this, we have value 0 in ncstr->port
 			ncstr->port = intdup(cstr->port);
--- a/src/constraint-libressl.c	2020-08-01 19:50:24.130263065 +0300
+++ b/src/constraint-libressl.c	2020-08-04 00:01:30.008179382 +0300
@@ -26,7 +26,7 @@
 
 struct httpsdate *
 httpsdate_init(const char *addr, const int *port, const char *hostname,
-    const char *path, const u_int8_t *ca, size_t ca_len)
+    const char *path, const char *useragent, const u_int8_t *ca, size_t ca_len)
 {
 	struct httpsdate	*httpsdate = NULL;
 	char	port_s[sizeof(port)];
@@ -45,10 +45,23 @@ httpsdate_init(const char *addr, const i
 	    (httpsdate->tls_path = strdup(path)) == NULL)
 		goto fail;
 
-	if (asprintf(&httpsdate->tls_request,
-	    "HEAD %s HTTP/1.1\r\nHost: %s\r\nConnection: close\r\n\r\n",
-	    httpsdate->tls_path, httpsdate->tls_hostname) == -1)
-		goto fail;
+	if (useragent)
+		httpsdate->tls_useragent = strdup(useragent);
+
+	if (httpsdate->tls_useragent) {
+		if (asprintf(&httpsdate->tls_request,
+			"HEAD %s HTTP/1.1\r\nHost: %s\r\nUser-Agent: %s\r\nConnection: close\r\n\r\n",
+			httpsdate->tls_path,
+			httpsdate->tls_hostname,
+			httpsdate->tls_useragent) == -1)
+			goto fail;
+	} else {
+		if (asprintf(&httpsdate->tls_request,
+			"HEAD %s HTTP/1.1\r\nHost: %s\r\nConnection: close\r\n\r\n",
+			httpsdate->tls_path,
+			httpsdate->tls_hostname) == -1)
+			goto fail;
+	}
 
 	if ((httpsdate->tls_config = tls_config_new()) == NULL)
 		goto fail;
@@ -110,6 +123,10 @@ httpsdate_request(struct httpsdate *http
 	if (tls_configure(httpsdate->tls_ctx, httpsdate->tls_config) == -1)
 		goto fail;
 
+	if (httpsdate->tls_useragent)
+		log_debug("constraint %s: user agent: %s", httpsdate->tls_addr,
+				  httpsdate->tls_useragent);
+
 	/*
 	 * LibreSSL expects an address string, which can also be a DNS name,
 	 * but we pass a pre-resolved IP address string in tls_addr so it
@@ -222,14 +239,14 @@ httpsdate_request(struct httpsdate *http
 
 void *
 httpsdate_query(const char *addr, const int *port, const char *hostname,
-    const char *path, const u_int8_t *ca, size_t ca_len,
+    const char *path, const char *useragent, const u_int8_t *ca, size_t ca_len,
     struct timeval *rectv, struct timeval *xmttv)
 {
 	struct httpsdate	*httpsdate;
 	struct timeval		 when;
 	time_t			 t;
 
-	if ((httpsdate = httpsdate_init(addr, port, hostname, path,
+	if ((httpsdate = httpsdate_init(addr, port, hostname, path, useragent,
 	    ca, ca_len)) == NULL)
 		return (NULL);
 
--- a/src/constraint-openssl.c	2020-08-03 19:23:54.377109002 +0300
+++ b/src/constraint-openssl.c	2020-08-04 00:01:16.178179367 +0300
@@ -37,11 +37,20 @@ o_httpsdate_init(struct constraint *cstr
 	if ((httpsdate->cstr = cstr) == NULL)
 		goto fail;
 
-	if (asprintf(&httpsdate->tls_request,
-	    "HEAD %s HTTP/1.1\r\nHost: %s\r\nConnection: close\r\n\r\n",
-		httpsdate->cstr->addr_head.path,
-		httpsdate->cstr->addr_head.name) == -1)
-		goto fail;
+	if (httpsdate->cstr->useragent) {
+		if (asprintf(&httpsdate->tls_request,
+			"HEAD %s HTTP/1.1\r\nHost: %s\r\nUser-Agent: %s\r\nConnection: close\r\n\r\n",
+			httpsdate->cstr->addr_head.path,
+			httpsdate->cstr->addr_head.name,
+			httpsdate->cstr->useragent) == -1)
+			goto fail;
+	} else {
+		if (asprintf(&httpsdate->tls_request,
+			"HEAD %s HTTP/1.1\r\nHost: %s\r\nConnection: close\r\n\r\n",
+			httpsdate->cstr->addr_head.path,
+			httpsdate->cstr->addr_head.name) == -1)
+			goto fail;
+	}
 
 	if ((httpsdate->tls_method = TLS_method()) == NULL)
 		goto fail;
@@ -161,6 +170,10 @@ o_httpsdate_request(struct o_httpsdate *
 			goto fail;
 	}
 
+	if (httpsdate->cstr->useragent)
+		log_debug("constraint %s: user agent: %s", ia_str,
+				  httpsdate->cstr->useragent);
+
 	log_debug("constraint %s: establishing connection", ia_str);
 	ret = SSL_connect(httpsdate->tls_conn);
 	if (ret < 1) {
--- a/src/ntpd.conf.5	2020-08-03 23:21:11.124672226 +0300
+++ b/src/ntpd.conf.5	2020-08-04 01:38:53.878185531 +0300
@@ -14,7 +14,7 @@
 .\" AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
 .\" OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\"
-.Dd $Mdocdate: August 01 2020 $
+.Dd $Mdocdate: August 04 2020 $
 .Dt NTPD.CONF 5
 .Os
 .Sh NAME
@@ -58,14 +58,12 @@ is given as an address,
 .Xr ntpd 8
 will listen on all local addresses using the specified routing table.
 .Xr ntpd 8
-does not listen on any address by default.
-The optional
+does not listen on any address by default. The optional
 .Ic rtable
 keyword will specify which routing table to listen on, if the operating system supports rdomains.
 By default
 .Xr ntpd 8
-will listen using the current routing table.
-The optional
+will listen using the current routing table. The optional
 .Ic port
 keyword will specify which local UDP port the NTP server process should use for inbound connections.
 By default
@@ -240,18 +238,29 @@ Configuring a constraint without proper
 .Xr ntpd 8
 to log a warning message on startup.
 .Bl -tag -width Ds
-.It Ic constraint from Ar url [ip...]
+.It Xo Ic constraint from Ar url
+.Op Ar ip...
 .Op Ic port Ar port-number
+.Op Ic useragent Ar agent-string
+.Xc
 Specify the URL, IP address or the hostname of an HTTPS server to
 provide a constraint. The optional
 .Ic port
 number is an HTTPS server port to connect to. By default
 .Xr ntpd 8
-will connect to remote TCP port 443.
-If the url is followed by one or more addresses the url and addresses will be
+will connect to remote TCP port 443. The optional
+.Ic useragent
+string adds a defined user agent string into a constraint HTTP 
+request. This option helps retrieving a time constraint from HTTPS
+servers which block user agentless HTTP
+requests. If the
+.Ic url
+is followed by one or more
+.Ic ip
+addresses the URL and addresses will be
 tried until a working one is found.
-The url path and expected certificate name is always taken from the
-url specified.
+The URL path and expected certificate name is always taken from the
+URL specified.
 If
 .Ic constraint from
 is used more than once,
@@ -259,29 +268,34 @@ is used more than once,
 will calculate a median constraint from all the servers specified.
 .Bd -literal -offset indent
 server ntp.example.org
-constraint from www.example.com
+constraint from "www.example.com"
 constraint from "https://9.9.9.9" "2620:fe::9"
-constraint from www.google.com port 443
+constraint from "www.google.com" port 443 useragent "OpenNTPD time query"
 .Ed
-.It Ic constraints from Ar url
+.It Xo Ic constraints from Ar url
 .Op Ic port Ar port-number
+.Op Ic useragent Ar agent-string
+.Xc
 As with
 .Ic constraint from ,
 specify the URL, IP address or the hostname of an HTTPS server to
 provide a constraint.
 Should the hostname resolve to multiple IP addresses,
 .Xr ntpd 8
-will calculate a median constraint from all of them.
-The optional
+will calculate a median constraint from all of them. The optional
 .Ic port
 number is an HTTPS server port to connect to. By default
 .Xr ntpd 8
-will connect to remote TCP port 443.
+will connect to remote TCP port 443. The optional
+.Ic useragent
+string adds a defined user agent string into a constraint HTTP
+request. This option helps retrieving a time constraint from HTTPS
+servers which block user agentless HTTP requests.
 For example:
 .Bd -literal -offset indent
 servers pool.ntp.org
 constraints from "https://www.google.com/"
-constraints from "https://duckduckgo.com/" port 443
+constraints from "https://duckduckgo.com/" port 443 useragent "OpenNTPD time query"
 .Ed
 .El
 .Sh ADVANCED KEYWORDS
@@ -676,6 +690,16 @@ Negligible drift time to not log in mill
 32
 .El
 .Ed
+.It Ic max_display_width Ar number
+Maximum number of characters in a
+.Xr ntpctl 8
+report line (peers, status, sensors and all).
+.Bd -literal -offset indent
+.Bl -tag -width "Default:" -compact
+.It Default:
+80
+.El
+.Ed
 .It Ic max_frequency_adjust Ar decimal
 Maximum allowed frequency correction per iteration.
 .Bd -literal -offset indent
@@ -780,6 +804,14 @@ Sensor default reference ID string.
 "HARD"
 .El
 .Ed
+.It Ic sensor_offsets Ar seconds
+Maximum allowed sensor time offset in seconds.
+.Bd -literal -offset indent
+.Bl -tag -width "Default:" -compact
+.It Default:
+6
+.El
+.Ed
 .It Ic sensor_query_interval Ar seconds
 Sensor query interval in seconds.
 .Bd -literal -offset indent
--- a/ChangeLog	2020-08-02 14:01:47.093664999 +0300
+++ b/ChangeLog	2020-08-04 01:52:06.054853035 +0300
@@ -32,6 +32,10 @@ OpenNTPD Portable Release Notes:
 
 	* Many previously hardcoded values are now configurable via conf file.
 
+	* Implement UDP & TCP port selection for multiple options.
+
+	* Implement custom user agent string support for constraints.
+
 	* Implemented OpenSSL support. Either LibreSSL or OpenSSL can be used.
 
 	* Improved log entries interpretation.