Merge pull request networkupstools#2407 from jimklimov/nut-upsmon

Introduce a `rootpidpath()` method instead of direct use of `PIDPATH` macro (e.g. in `upsmon`)

NEWS.adoc

@@ -86,6 +86,11 @@ https://github.com/networkupstools/nut/milestone/11
    * added an `OBLBDURATION` (seconds) setting to optionally delay raising
      the alarm for immediate shutdown in critical situation. [#321]
 
+ - common code: root-owned daemons now use not the hard-coded `PIDPATH` value
+   set by the `configure` script during build, but can override it with a
+   `NUT_PIDPATH` environment variable in certain use-cases (such as tests).
+   [#2407]
+
 
 Release notes for NUT 2.8.2 - what's new since 2.8.1
 ----------------------------------------------------

clients/upsmon.c

@@ -2100,9 +2100,9 @@ static void loadconfig(void)
 		upslogx(LOG_WARNING, "No POWERDOWNFLAG value was configured in %s!",
 			configfile);
 		upslogx(LOG_INFO,
-			"Should be a path to file that is normally writeable "
-			"for root user, and remains at least readable late "
-			"in shutdown after all unmounting completes.");
+			"POWERDOWNFLAG should be a path to file that is normally "
+			"writeable for root user, and remains at least readable "
+			"late in shutdown after all unmounting completes.");
 	}
 }
 
@@ -3009,7 +3009,7 @@ int main(int argc, char *argv[])
 	 * is running (error if it is).
 	 */
 	/* Hush the fopen(pidfile) message but let "real errors" be seen */
-	nut_sendsignal_debug_level = NUT_SENDSIGNAL_DEBUG_LEVEL_FOPEN_PIDFILE - 1;
+	nut_sendsignal_debug_level = NUT_SENDSIGNAL_DEBUG_LEVEL_KILL_SIG0PING - 1;
 #ifndef WIN32
 	/* If cmd == 0 we are starting and check if a previous instance
 	 * is running by sending signal '0' (i.e. 'kill <pid> 0' equivalent)

common/common.c

@@ -447,7 +447,7 @@ void writepid(const char *name)
 	if (*name == '/')
 		snprintf(fn, sizeof(fn), "%s", name);
 	else
-		snprintf(fn, sizeof(fn), "%s/%s.pid", PIDPATH, name);
+		snprintf(fn, sizeof(fn), "%s/%s.pid", rootpidpath(), name);
 
 	mask = umask(022);
 	pidf = fopen(fn, "w");
@@ -487,7 +487,7 @@ int sendsignalpid(pid_t pid, int sig)
 	ret = kill(pid, 0);
 
 	if (ret < 0) {
-		if (nut_debug_level > 0 || nut_sendsignal_debug_level > 1)
+		if (nut_debug_level > 0 || nut_sendsignal_debug_level >= NUT_SENDSIGNAL_DEBUG_LEVEL_KILL_SIG0PING)
 			perror("kill");
 		return -1;
 	}
@@ -661,7 +661,7 @@ int sendsignal(const char *progname, int sig)
 {
 	char	fn[SMALLBUF];
 
-	snprintf(fn, sizeof(fn), "%s/%s.pid", PIDPATH, progname);
+	snprintf(fn, sizeof(fn), "%s/%s.pid", rootpidpath(), progname);
 
 	return sendsignalfn(fn, sig);
 }
@@ -1446,7 +1446,13 @@ static void vupslog(int priority, const char *fmt, va_list va, int use_strerror)
 /* Return the default path for the directory containing configuration files */
 const char * confpath(void)
 {
-	const char *path = getenv("NUT_CONFPATH");
+	static const char *path = NULL;
+
+	/* Cached by earlier calls? */
+	if (path)
+		return path;
+
+	path = getenv("NUT_CONFPATH");
 
 #ifdef WIN32
 	if (path == NULL) {
@@ -1457,13 +1463,22 @@ const char * confpath(void)
 
 	/* We assume, here and elsewhere, that
 	 * at least CONFPATH is always defined */
-	return (path != NULL && *path != '\0') ? path : CONFPATH;
+	if (path == NULL || *path == '\0')
+		path = CONFPATH;
+
+	return path;
 }
 
 /* Return the default path for the directory containing state files */
 const char * dflt_statepath(void)
 {
-	const char *path = getenv("NUT_STATEPATH");
+	static const char *path = NULL;
+
+	/* Cached by earlier calls? */
+	if (path)
+		return path;
+
+	path = getenv("NUT_STATEPATH");
 
 #ifdef WIN32
 	if (path == NULL) {
@@ -1474,7 +1489,10 @@ const char * dflt_statepath(void)
 
 	/* We assume, here and elsewhere, that
 	 * at least STATEPATH is always defined */
-	return (path != NULL && *path != '\0') ? path : STATEPATH;
+	if (path == NULL || *path == '\0')
+		path = STATEPATH;
+
+	return path;
 }
 
 /* Return the alternate path for pid files, for processes running as non-root
@@ -1485,7 +1503,11 @@ const char * dflt_statepath(void)
  */
 const char * altpidpath(void)
 {
-	const char * path;
+	static const char *path = NULL;
+
+	/* Cached by earlier calls? */
+	if (path)
+		return path;
 
 	path = getenv("NUT_ALTPIDPATH");
 	if ( (path == NULL) || (*path == '\0') ) {
@@ -1503,11 +1525,43 @@ const char * altpidpath(void)
 		return path;
 
 #ifdef ALTPIDPATH
-	return ALTPIDPATH;
+	path = ALTPIDPATH;
 #else
 	/* With WIN32 in the loop, this may be more than a fallback to STATEPATH: */
-	return dflt_statepath();
+	path = dflt_statepath();
+#endif
+
+	return path;
+}
+
+/* Return the main path for pid files, for processes running as root, such
+ * as upsmon. Typically this is the built-in PIDPATH (from configure script)
+ * but certain use-cases such as the test suite can override it with the
+ * NUT_PIDPATH environment variable.
+ */
+const char * rootpidpath(void)
+{
+	static const char *path = NULL;
+
+	/* Cached by earlier calls? */
+	if (path)
+		return path;
+
+	path = getenv("NUT_PIDPATH");
+
+#ifdef WIN32
+	if (path == NULL) {
+		/* fall back to built-in pathname relative to binary/workdir */
+		path = getfullpath(PATH_ETC);
+	}
 #endif
+
+	/* We assume, here and elsewhere, that
+	 * at least PIDPATH is always defined */
+	if (path == NULL || *path == '\0')
+		path = PIDPATH;
+
+	return path;
 }
 
 /* Die with a standard message if socket filename is too long */

common/nutipc.cpp

@@ -5,6 +5,10 @@
 
         Author: Vaclav Krpec  <[email protected]>
 
+    Copyright (C) 2024 NUT Community
+
+        Author: Jim Klimov  <[email protected]>
+
     This program is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
     the Free Software Foundation; either version 2 of the License, or
@@ -35,6 +39,7 @@
 # define HAVE_LOCALTIME_R 111
 #endif
 
+#include "common.h"
 #include "nutipc.hpp"
 #include "nutstream.hpp"
 
@@ -293,8 +298,9 @@ int Signal::send(Signal::enum_t signame, const std::string & pid_file) {
 int NutSignal::send(NutSignal::enum_t signame, const std::string & process) {
 	std::string pid_file;
 
-	// TBD: What's ALTPIDPATH and shouldn't we also consider it?
-	pid_file += PIDPATH;
+	// FIXME: What about ALTPIDPATH (for non-root daemons)
+	// and shouldn't we also consider it (e.g. try/catch)?
+	pid_file += rootpidpath();
 	pid_file += '/';
 	pid_file += process;
 	pid_file += ".pid";

common/nutstream.cpp

@@ -3,6 +3,7 @@
 
     Copyright (C)
         2012	Vaclav Krpec  <[email protected]>
+        2024	Jim Klimov <[email protected]>
 
     This program is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by

drivers/main.c

@@ -2118,7 +2118,7 @@ int main(int argc, char **argv)
 	 */
 
 	/* Hush the fopen(pidfile) message but let "real errors" be seen */
-	nut_sendsignal_debug_level = NUT_SENDSIGNAL_DEBUG_LEVEL_FOPEN_PIDFILE - 1;
+	nut_sendsignal_debug_level = NUT_SENDSIGNAL_DEBUG_LEVEL_KILL_SIG0PING - 1;
 
 	if (!cmd && (!do_forceshutdown)) {
 		ssize_t	cmdret = -1;

drivers/upsdrvctl.c

@@ -301,7 +301,7 @@ static void signal_driver_cmd(const ups_t *ups,
 		return;
 
 	/* Hush the fopen(pidfile) message but let "real errors" be seen */
-	nut_sendsignal_debug_level = NUT_SENDSIGNAL_DEBUG_LEVEL_FOPEN_PIDFILE - 1;
+	nut_sendsignal_debug_level = NUT_SENDSIGNAL_DEBUG_LEVEL_KILL_SIG0PING - 1;
 #ifndef WIN32
 	if (ups->pid == -1) {
 		ret = sendsignalfn(pidfn, cmd);
@@ -377,7 +377,7 @@ static void stop_driver(const ups_t *ups)
 		return;
 
 	/* Hush the fopen(pidfile) message but let "real errors" be seen */
-	nut_sendsignal_debug_level = NUT_SENDSIGNAL_DEBUG_LEVEL_FOPEN_PIDFILE - 1;
+	nut_sendsignal_debug_level = NUT_SENDSIGNAL_DEBUG_LEVEL_KILL_SIG0PING - 1;
 
 #ifndef WIN32
 	if (ups->pid == -1) {

include/common.h

@@ -264,9 +264,12 @@ const char * confpath(void);
 /* Return the default path for the directory containing state files */
 const char * dflt_statepath(void);
 
-/* Return the alternate path for pid files */
+/* Return the alternate path for pid files (non-root daemons) */
 const char * altpidpath(void);
 
+/* Return the main path for pid files (root daemons like upsmon) */
+const char * rootpidpath(void);
+
 /* Die with a standard message if socket filename is too long */
 void check_unix_socket_filename(const char *fn);
 
@@ -352,6 +355,7 @@ void nut_prepare_search_paths(void);
 extern int nut_sendsignal_debug_level;
 #define NUT_SENDSIGNAL_DEBUG_LEVEL_DEFAULT 6
 #define NUT_SENDSIGNAL_DEBUG_LEVEL_FOPEN_PIDFILE 5
+#define NUT_SENDSIGNAL_DEBUG_LEVEL_KILL_SIG0PING 4
 
 extern int nut_debug_level;
 extern int nut_log_level;

include/nutipc.hpp

@@ -5,6 +5,10 @@
 
         Author: Vaclav Krpec  <[email protected]>
 
+    Copyright (C) 2024 NUT Community
+
+        Author: Jim Klimov  <[email protected]>
+
     This program is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
     the Free Software Foundation; either version 2 of the License, or

include/nutstream.hpp

@@ -3,6 +3,7 @@
 
     Copyright (C)
 	2012	Vaclav Krpec  <[email protected]>
+	2024	Jim Klimov <[email protected]>
 
     This program is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by

include/nutwriter.hpp

@@ -3,6 +3,7 @@
 
     Copyright (C)
 	2012	Vaclav Krpec  <[email protected]>
+	2024	Jim Klimov <[email protected]>
 
     This program is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by

server/upsd.c

@@ -191,6 +191,8 @@ upstype_t *get_ups_ptr(const char *name)
 	upstype_t	*tmp;
 
 	if (!name) {
+		upsdebugx(3, "%s: not a valid UPS: <null>",
+			__func__);
 		return NULL;
 	}
 
@@ -200,6 +202,8 @@ upstype_t *get_ups_ptr(const char *name)
 		}
 	}
 
+	upsdebugx(3, "%s: not a valid UPS: %s",
+		__func__, NUT_STRARG(name));
 	return NULL;
 }
 
@@ -2033,7 +2037,7 @@ int main(int argc, char **argv)
 	 * is running (error if it is).
 	 */
 	/* Hush the fopen(pidfile) message but let "real errors" be seen */
-	nut_sendsignal_debug_level = NUT_SENDSIGNAL_DEBUG_LEVEL_FOPEN_PIDFILE - 1;
+	nut_sendsignal_debug_level = NUT_SENDSIGNAL_DEBUG_LEVEL_KILL_SIG0PING - 1;
 #ifndef WIN32
 	/* If cmd == 0 we are starting and check if a previous instance
 	 * is running by sending signal '0' (i.e. 'kill <pid> 0' equivalent)