Further NUT for Windows fixes: path discovery, CGI under IIS, etc.

UPGRADING.adoc

@@ -50,6 +50,12 @@ Changes from 2.8.4 to 2.8.5
   installed (and possibly customized) with the `*.html.sample` files delivered
   by the new build. [PR #3180]
 
+- Introduced a `@NUT_UPSSTATS_TEMPLATE@` command which the NUT CGI template
+  files now MUST start with (safety check that we are reading a template).
+  While the delivered `upsstats*.html.sample` files would include the change,
+  ultimate `upsstats*.html` templates deployed for end-users MUST be updated.
+  [issue #3252, PR #3249]
+
 - Dropped the `compile` script from Git sources. It originates from automake
   and is added to work area (if missing) during `autogen.sh` rituals anyway
   (as `make` says, `'automake --add-missing' can install 'compile'` when you

appveyor.yml

@@ -106,6 +106,15 @@ build_script:
         set MSYSTEM=MINGW64
         REM Note: currently we save job time and do not install asciidoc/a2x
         REM  # --with-docs="man=auto html-single=auto html-chunked=no pdf=no"
+        REM The resulting configuration defaults to --prefix=/mingw{32,64}
+        REM as appropriate for the platform, which ends up as a subdirectory
+        REM under DESTDIR when we `make install` later, and in our 7z archive.
+        REM The builds are relocatable however, so end-users can extract to
+        REM e.g. "C:\Program Files\NUT" and forfeit "mingwXX" part, probably,
+        REM but this can complicate automatic relative directory resolution
+        REM to find "nearby" program or configuration files (see common.c
+        REM for current implementation). Hard-coded fallback strings may
+        REM end up getting used in those cases.
         C:\msys64\usr\bin\bash -lc 'date -u; PATH="/mingw64/bin:$PATH" CI_SKIP_CHECK=true CANBUILD_WITH_LIBMODBUS_USB=yes ./ci_build.sh --with-docs=no'
 
 

clients/cgilib.c

@@ -116,42 +116,120 @@ void extractcgiargs(void)
 
 void extractpostargs(void)
 {
-	char	buf[SMALLBUF], *ptr, *cleanval;
-	int	ch;
+	char	buf[SMALLBUF], *ptr, *cleanval, *server_software = NULL;
+	int	ch, content_length = -1, bytes_seen = 0;
+	size_t	buflen;
+
+	/* First, see if there's anything waiting...
+	 * the server may not close STDIN properly
+	 * or somehow delay opening/populating it. */
+#ifndef WIN32
+	int	selret;
+	fd_set	fds;
+	struct timeval	tv;
+
+	FD_ZERO(&fds);
+	FD_SET(STDIN_FILENO, &fds);
+	tv.tv_sec = 0;
+	tv.tv_usec = 250000; /* wait for up to 250ms for a POST query to come */
+
+	selret = select(STDIN_FILENO+1, &fds, NULL, NULL, &tv);
+	if (selret <= 0) {
+#else
+	HANDLE	hSTDIN = GetStdHandle(STD_INPUT_HANDLE);
+	DWORD	selret = WaitForSingleObject(hSTDIN, 250);
+	if (selret != WAIT_OBJECT_0) { /* or == WAIT_TIMEOUT ? */
+#endif	/* WIN32 */
+		upsdebug_with_errno(1, "%s: no stdin is waiting (%" PRIiMAX ")<br/>", __func__, (intmax_t)selret);
+		return;
+	}
 
-	ch = fgetc(stdin);
 	buf[0] = '\0';
 
-	while (ch != EOF) {
-		if (ch == '&') {
+	/* Does the web server tell us how much it sent
+	 * (and might keep the channel open... indefinitely)? */
+	ptr = getenv("CONTENT_LENGTH");
+	if (ptr) {
+		content_length = atoi(ptr);
+	}
+
+	ptr = getenv("SERVER_SOFTWARE");
+	if (ptr) {
+		server_software = ptr;
+	} else {
+		server_software = "";
+	}
+
+	if (content_length > 0 && strstr(server_software, "IIS")) {
+		/* Our POSTs end with a newline, and that one never arrives
+		 * (reads hang), possibly buffered output from IIS?
+		 * Our own setmode() in e.g. upsset.c does not help.
+		 * So upsset.c ends each FORM with do_hidden_sentinel()
+		 * to sacrifice a few bytes we would not use.
+		 */
+		upsdebugx(3, "%s: truncating expected content length on IIS<br/>", __func__);
+		content_length--;
+	}
+	upsdebugx(3, "%s: starting to read %d POSTed bytes on server '%s'<br/>", __func__, content_length, server_software);
+
+	ch = fgetc(stdin);
+	upsdebugx(6, "%s: got char: '%c' (%d, 0x%02X)<br/>", __func__, ch, ch, (unsigned int)ch);
+
+	if (ch == EOF) {
+		bytes_seen++;
+		upsdebugx(3, "%s: got immediate EOF in stdin<br/>", __func__);
+	} else while(1) {
+		bytes_seen++;
+		if (ch == '&' || ch == EOF || (content_length >= 0 && bytes_seen >= content_length)) {
+			buflen = strlen(buf);
+			upsdebugx(1, "%s: collected a chunk of %" PRIuSIZE " bytes on stdin: %s<br/>",
+				__func__, buflen, buf);
 			ptr = strchr(buf, '=');
-			if (!ptr)
+			if (!ptr) {
+				upsdebugx(3, "%s: parsearg('%s', '')<br/>", __func__, buf);
 				parsearg(buf, "");
-			else {
+			} else {
 				*ptr++ = '\0';
 				cleanval = unescape(ptr);
+				upsdebugx(3, "%s: parsearg('%s', '%s')<br/>", __func__, buf, cleanval);
 				parsearg(buf, cleanval);
 				free(cleanval);
 			}
 			buf[0] = '\0';
+
+			if (ch == EOF || (content_length >= 0 && bytes_seen >= content_length))
+				break;	/* end the loop */
 		}
 		else
 			snprintfcat(buf, sizeof(buf), "%c", ch);
 
+#ifndef WIN32
+		/* Must re-init every time when looping (array is changed by select method) */
+		FD_ZERO(&fds);
+		FD_SET(STDIN_FILENO, &fds);
+		tv.tv_sec = 0;
+		tv.tv_usec = 250000; /* wait for up to 250ms  for a POST response */
+
+		selret = select(STDIN_FILENO+1, &fds, NULL, NULL, &tv);
+		if (selret <= 0) {
+#else
+		selret = WaitForSingleObject(hSTDIN, 250);
+		if (selret != WAIT_OBJECT_0) { /* or == WAIT_TIMEOUT ? */
+#endif
+			/* We do not always get EOF, so assume the input stream stopped */
+			upsdebug_with_errno(1, "%s: timed out waiting for an stdin byte (%" PRIiMAX ")<br/>", __func__, (intmax_t)selret);
+			break;
+		}
+
+		fflush(stderr);
 		ch = fgetc(stdin);
-	}
+		upsdebugx(6, "%s: got char: '%c' (%d, 0x%02X)<br/>", __func__, ch, ch, (unsigned int)ch);
+		if (ch == EOF)
+			upsdebugx(3, "%s: got proper stdin EOF<br/>", __func__);
+		upsdebugx(6, "%s: processed %d bytes with %d expected incoming content length on server '%s'<br/>", __func__, bytes_seen, content_length, server_software);
+	}	/* end of infinite loop */
 
-	if (strlen(buf) != 0) {
-		ptr = strchr(buf, '=');
-		if (!ptr)
-			parsearg(buf, "");
-		else {
-			*ptr++ = '\0';
-			cleanval = unescape(ptr);
-			parsearg(buf, cleanval);
-			free(cleanval);
-		}
-	}
+	upsdebugx(3, "%s: processed %d bytes with %d incoming content length<br/>", __func__, bytes_seen, content_length);
 }
 
 /* called for fatal errors in parseconf like malloc failures */

clients/upsimage.c

@@ -614,12 +614,38 @@ static int get_var(const char *var, char *buf, size_t buflen)
 
 int main(int argc, char **argv)
 {
-	char	str[SMALLBUF];
+	char	str[SMALLBUF], *s;
 	int	i, min, nom, max;
 	double	var = 0;
+
+#ifdef WIN32
+        /* Required ritual before calling any socket functions */
+        static WSADATA  WSAdata;
+        static int      WSA_Started = 0;
+        if (!WSA_Started) {
+                WSAStartup(2, &WSAdata);
+                atexit((void(*)(void))WSACleanup);
+                WSA_Started = 1;
+        }
+
+	/* Avoid binary output conversions, e.g.
+	 * mangling what looks like CRLF on WIN32 */
+	setmode(STDOUT_FILENO, O_BINARY);
+#endif
+
 	NUT_UNUSED_VARIABLE(argc);
 	NUT_UNUSED_VARIABLE(argv);
 
+	/* NOTE: Caller must `export NUT_DEBUG_LEVEL` to see debugs for upsc
+	 * and NUT methods called from it. This line aims to just initialize
+	 * the subsystem, and set initial timestamp. Debugging the client is
+	 * primarily of use to developers, so is not exposed via `-D` args.
+	 */
+	s = getenv("NUT_DEBUG_LEVEL");
+	if (s && str_to_int(s, &i, 10) && i > 0) {
+		nut_debug_level = i;
+	}
+
 	extractcgiargs();
 
 	upscli_init_default_connect_timeout(NULL, NULL, UPSCLI_DEFAULT_CONNECT_TIMEOUT);

clients/upsset.c

@@ -170,6 +170,14 @@ static void do_hidden(const char *next)
 			next);
 }
 
+static void do_hidden_sentinel(void)
+{
+	/* MS IIS tends to not close CGI STDIN and not serve the last byte(s)
+	 * but just hangs at fgets(), so we truncate the inputs in cgilib,
+	 * and add a dummy entry here that we can afford to lose in the end */
+	printf("<INPUT TYPE=\"HIDDEN\" NAME=\"zzz\" VALUE=\"sentinel\">\n");
+}
+
 /* generate SELECT chooser from hosts.conf entries */
 static void upslist_arg(size_t numargs, char **arg)
 {
@@ -202,7 +210,7 @@ static void do_pickups(const char *currfunc)
 
 	snprintf(hostfn, sizeof(hostfn), "%s/hosts.conf", confpath());
 
-	printf("<FORM METHOD=\"POST\" ACTION=\"upsset.cgi\">\n");
+	printf("<FORM METHOD=\"POST\" ACTION=\"upsset.cgi" EXEEXT "\">\n");
 
 	printf("Select UPS and function:\n<BR>\n");
 
@@ -258,6 +266,8 @@ static void do_pickups(const char *currfunc)
 	do_hidden(NULL);
 
 	printf("<INPUT TYPE=\"SUBMIT\" VALUE=\"View\">\n");
+
+	do_hidden_sentinel();
 	printf("</FORM>\n");
 }
 
@@ -315,7 +325,7 @@ static void loginscreen(void)
 static void loginscreen(void)
 {
 	do_header("Login");
-	printf("<FORM METHOD=\"POST\" ACTION=\"upsset.cgi\">\n");
+	printf("<FORM METHOD=\"POST\" ACTION=\"upsset.cgi" EXEEXT "\">\n");
 	start_table();
 
 	printf("<TR BGCOLOR=\"#60B0B0\">\n");
@@ -332,6 +342,7 @@ static void loginscreen(void)
 	printf("<INPUT TYPE=\"HIDDEN\" NAME=\"function\" VALUE=\"pickups\">\n");
 	printf("<INPUT TYPE=\"SUBMIT\" VALUE=\"Login\">\n");
 	printf("<INPUT TYPE=\"RESET\" VALUE=\"Reset fields\">\n");
+	do_hidden_sentinel();
 	printf("</TD></TR></TABLE>\n");
 	printf("</FORM>\n");
 	printf("</TD></TR></TABLE>\n");
@@ -445,7 +456,7 @@ static void showcmds(void)
 			"This UPS doesn't support any instant commands.");
 
 	do_header("Instant commands");
-	printf("<FORM ACTION=\"upsset.cgi\" METHOD=\"POST\">\n");
+	printf("<FORM METHOD=\"POST\" ACTION=\"upsset.cgi" EXEEXT "\">\n");
 	start_table();
 
 	/* include the description from checkhost() if present */
@@ -483,6 +494,7 @@ static void showcmds(void)
 	printf("<INPUT TYPE=\"HIDDEN\" NAME=\"monups\" VALUE=\"%s\">\n", monups);
 	printf("<INPUT TYPE=\"SUBMIT\" VALUE=\"Issue command\">\n");
 	printf("<INPUT TYPE=\"RESET\" VALUE=\"Reset\">\n");
+	do_hidden_sentinel();
 	printf("</TD></TR>\n");
 	printf("</TABLE>\n");
 	printf("</FORM>\n");
@@ -873,7 +885,7 @@ static void showsettings(void)
 	}
 
 	do_header("Current settings");
-	printf("<FORM ACTION=\"upsset.cgi\" METHOD=\"POST\">\n");
+	printf("<FORM METHOD=\"POST\" ACTION=\"upsset.cgi" EXEEXT "\">\n");
 	start_table();
 
 	/* include the description from checkhost() if present */
@@ -905,6 +917,7 @@ static void showsettings(void)
 	printf("<INPUT TYPE=\"HIDDEN\" NAME=\"monups\" VALUE=\"%s\">\n", monups);
 	printf("<INPUT TYPE=\"SUBMIT\" VALUE=\"Save changes\">\n");
 	printf("<INPUT TYPE=\"RESET\" VALUE=\"Reset\">\n");
+	do_hidden_sentinel();
 	printf("</TD></TR>\n");
 	printf("</TABLE>\n");
 	printf("</FORM>\n");
@@ -1043,6 +1056,7 @@ static void check_conf(void)
 	PCONF_CTX_t	ctx;
 
 	snprintf(fn, sizeof(fn), "%s/upsset.conf", confpath());
+	upsdebugx(1, "%s: considering configuration file %s", __func__, fn);
 
 	pconf_init(&ctx, upsset_conf_err);
 
@@ -1092,30 +1106,50 @@ static void check_conf(void)
 
 int main(int argc, char **argv)
 {
+	char *s;
+	int i;
+
+#ifdef WIN32
+        /* Required ritual before calling any socket functions */
+        static WSADATA  WSAdata;
+        static int      WSA_Started = 0;
+        if (!WSA_Started) {
+                WSAStartup(2, &WSAdata);
+                atexit((void(*)(void))WSACleanup);
+                WSA_Started = 1;
+        }
+
+	/* Avoid binary output conversions, e.g.
+	 * mangling what looks like CRLF on WIN32 */
+	setmode(STDOUT_FILENO, O_BINARY);
+	/* Also do not break what we receive from HTTP POST queries */
+	setmode(STDIN_FILENO, O_BINARY);
+#endif
+
 	NUT_UNUSED_VARIABLE(argc);
 	NUT_UNUSED_VARIABLE(argv);
 	username = password = function = monups = NULL;
 
 	printf("Content-type: text/html\n\n");
 
+	/* NOTE: Caller must `export NUT_DEBUG_LEVEL` to see debugs for upsc
+	 * and NUT methods called from it. This line aims to just initialize
+	 * the subsystem, and set initial timestamp. Debugging the client is
+	 * primarily of use to developers, so is not exposed via `-D` args.
+	 */
+	s = getenv("NUT_DEBUG_LEVEL");
+	if (s && str_to_int(s, &i, 10) && i > 0) {
+		nut_debug_level = i;
+	}
+
 	/* see if the magic string is present in the config file */
 	check_conf();
 
 	upscli_init_default_connect_timeout(NULL, NULL, UPSCLI_DEFAULT_CONNECT_TIMEOUT);
 
-	/* see if there's anything waiting .. the server my not close STDIN properly */
-	if (1) {
-		fd_set fds;
-		struct timeval tv;
+	extractpostargs();
 
-		FD_ZERO(&fds);
-		FD_SET(STDIN_FILENO, &fds);
-		tv.tv_sec = 0;
-		tv.tv_usec = 250000; /* wait for up to 250ms  for a POST response */
-
-		if ((select(STDIN_FILENO+1, &fds, 0, 0, &tv)) > 0)
-			extractpostargs();
-	}
+	/* Nothing POSTed (or parsed correctly)? */
 	if ((!username) || (!password) || (!function))
 		loginscreen();