From 81345e3487b85712287efc851e67ca60da59c3a1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Lorenz=20K=C3=A4stle?=
 <12514511+RincewindsHat@users.noreply.github.com>
Date: Tue, 7 Apr 2026 13:16:44 +0200
Subject: [PATCH 1/6] common.h: added guard to avoid warning when ENABLE_NLS is
 not defined (#2248)

Co-authored-by: Andreas Baumann <mail@andreasbaumann.cc>
---
 plugins/common.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/plugins/common.h b/plugins/common.h
index ef888d08..b3053486 100644
--- a/plugins/common.h
+++ b/plugins/common.h
@@ -193,7 +193,7 @@ enum {
  */
 #include "../gl/gettext.h"
 #define _(String) gettext(String)
-#if !ENABLE_NLS
+#if !defined(ENABLE_NLS) || !ENABLE_NLS
 #	undef textdomain
 #	define textdomain(Domainname) /* empty */
 #	undef bindtextdomain

From 7c20cb97292a8207b0fe4e76425b62409be68b12 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Lorenz=20K=C3=A4stle?=
 <12514511+RincewindsHat@users.noreply.github.com>
Date: Tue, 7 Apr 2026 13:16:59 +0200
Subject: [PATCH 2/6] check_snmp: fixed falltrhough case in
 ASN_FLOAT/ASN_DOUBLE (#2249)

Co-authored-by: Andreas Baumann <mail@andreasbaumann.cc>
---
 plugins/check_snmp.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/plugins/check_snmp.c b/plugins/check_snmp.c
index f470d222..1746fd79 100644
--- a/plugins/check_snmp.c
+++ b/plugins/check_snmp.c
@@ -116,6 +116,7 @@ gen_state_string_type gen_state_string(check_snmp_state_entry *entries, size_t n
 				break;
 			case ASN_FLOAT:
 				printf("Type FLOAT\n");
+				break;
 			case ASN_DOUBLE:
 				printf("Type DOUBLE\n");
 				break;
@@ -217,6 +218,7 @@ recover_state_data_type recover_state_data(char *state_string, idx_t state_strin
 				break;
 			case ASN_FLOAT:
 				printf("Type FLOAT\n");
+				break;
 			case ASN_DOUBLE:
 				printf("Type DOUBLE\n");
 				break;

From ddd1bd9fbd84b29fb169e592943d1fdfc8ad0d7e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Lorenz=20K=C3=A4stle?=
 <12514511+RincewindsHat@users.noreply.github.com>
Date: Tue, 7 Apr 2026 14:13:38 +0200
Subject: [PATCH 3/6] removed -Werror=declaration-after-statement from
 net-snmp-config --cflags causing trouble in check_snmp.c (#2250)

Co-authored-by: Andreas Baumann <mail@andreasbaumann.cc>
---
 plugins/Makefile.am | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/plugins/Makefile.am b/plugins/Makefile.am
index a35f273e..2bea8fc0 100644
--- a/plugins/Makefile.am
+++ b/plugins/Makefile.am
@@ -166,7 +166,7 @@ check_real_LDADD = $(NETLIBS)
 check_snmp_SOURCES = check_snmp.c check_snmp.d/check_snmp_helpers.c
 check_snmp_LDADD = $(BASEOBJS)
 check_snmp_LDFLAGS = $(AM_LDFLAGS) -lm `net-snmp-config --libs`
-check_snmp_CFLAGS = $(AM_CFLAGS) `net-snmp-config --cflags`
+check_snmp_CFLAGS = $(AM_CFLAGS) `net-snmp-config --cflags | sed 's/-Werror=declaration-after-statement//'`
 check_smtp_LDADD = $(SSLOBJS)
 check_ssh_LDADD = $(NETLIBS)
 check_swap_SOURCES = check_swap.c check_swap.d/swap.c

From 613cb60c96e21eaafb82b80a6b6d84b1b1f9729f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Lorenz=20K=C3=A4stle?=
 <12514511+RincewindsHat@users.noreply.github.com>
Date: Wed, 8 Apr 2026 17:21:44 +0200
Subject: [PATCH 4/6] check_curl: Clean up (#2252)

* check_curl: remove unused variables

* check_curl: run formatter on related files

* check_curl_helpers: make code a bit more understandable

* check_curl helpers: general api cleanup and code style
---
 plugins/check_curl.c                      |  88 +++--
 plugins/check_curl.d/check_curl_helpers.c | 372 +++++++++++++---------
 plugins/check_curl.d/check_curl_helpers.h |  28 +-
 plugins/t/check_curl.t                    |  44 +--
 plugins/tests/check_curl.t                |   4 +-
 5 files changed, 322 insertions(+), 214 deletions(-)

diff --git a/plugins/check_curl.c b/plugins/check_curl.c
index f63cdea2..b168cbcd 100644
--- a/plugins/check_curl.c
+++ b/plugins/check_curl.c
@@ -247,8 +247,9 @@ mp_subcheck check_http(const check_curl_config config, check_curl_working_state
 		printf("**** REQUEST CONTENT ****\n%s\n", workingState.http_post_data);
 	}
 
-	 // curl_state is updated after curl_easy_perform, and with updated curl_state certificate checks can be done
-	 // Check_http tries to check certs as early as possible, and exits with certificate check result by default. Behave similarly.
+	// curl_state is updated after curl_easy_perform, and with updated curl_state certificate checks
+	// can be done Check_http tries to check certs as early as possible, and exits with certificate
+	// check result by default. Behave similarly.
 #ifdef LIBCURL_FEATURE_SSL
 	if (workingState.use_ssl && config.check_cert) {
 		if (verbose > 1) {
@@ -1546,8 +1547,8 @@ void print_help(void) {
 	printf(" %s\n", "-I, --IP-address=ADDRESS");
 	printf("    %s\n",
 		   "IP address or name (use numeric address if possible to bypass DNS lookup).");
-	printf("    %s\n",
-		     "This overwrites the network address of the target while leaving everything else (HTTP headers) as they are");
+	printf("    %s\n", "This overwrites the network address of the target while leaving everything "
+					   "else (HTTP headers) as they are");
 	printf(" %s\n", "-p, --port=INTEGER");
 	printf("    %s", _("Port number (default: "));
 	printf("%d)\n", HTTP_PORT);
@@ -1611,7 +1612,8 @@ void print_help(void) {
 	printf("    %s\n", _("String to expect in the content"));
 	printf(" %s\n", "-u, --url=PATH");
 	printf("    %s\n", _("URL to GET or POST (default: /)"));
-	printf("    %s\n", _("This is the part after the address in a URL, so for \"https://example.com/index.html\" it would be '-u /index.html'"));
+	printf("    %s\n", _("This is the part after the address in a URL, so for "
+						 "\"https://example.com/index.html\" it would be '-u /index.html'"));
 	printf(" %s\n", "-P, --post=STRING");
 	printf("    %s\n", _("URL decoded http POST data"));
 	printf(" %s\n",
@@ -1643,11 +1645,12 @@ void print_help(void) {
 	printf("    %s\n", _("If port is not specified, libcurl defaults to 1080"));
 	printf("    %s\n", _("This value will be set as CURLOPT_PROXY"));
 	printf(" %s\n", "--noproxy=COMMA_SEPARATED_LIST");
-	printf("    %s\n", _("Specify hostnames, addresses and subnets where proxy should not be used"));
+	printf("    %s\n",
+		   _("Specify hostnames, addresses and subnets where proxy should not be used"));
 	printf("    %s\n", _("Example usage: \"example.com,::1,1.1.1.1,localhost,192.168.0.0/16\""));
 	printf("    %s\n", _("Do not use brackets when specifying IPv6 addresses"));
 	printf("    %s\n", _("Special case when an item is '*' : matches all hosts/addresses "
-		"and effectively disables proxy."));
+						 "and effectively disables proxy."));
 	printf("    %s\n", _("This value will be set as CURLOPT_NOPROXY"));
 	printf(" %s\n", "-a, --authorization=AUTH_PAIR");
 	printf("    %s\n", _("Username:password on sites with basic authentication"));
@@ -1757,38 +1760,59 @@ void print_help(void) {
 #endif
 
 	printf("\n %s\n", "CHECK WEBSERVER CONTENT VIA PROXY:");
-	printf(" %s\n", _("Proxies are specified or disabled for certain hosts/addresses using environment variables"
-		" or -x/--proxy and --noproxy arguments:"));
-	printf(" %s\n", _("Checked environment variables: all_proxy, http_proxy, https_proxy, no_proxy"));
-	printf(" %s\n", _("Environment variables can also be given in uppercase, but the lowercase ones will "
-					  "take predence if both are defined."));
-	printf(" %s\n", _("The environment variables are overwritten by -x/--proxy and --noproxy arguments:"));
+	printf(" %s\n", _("Proxies are specified or disabled for certain hosts/addresses using "
+					  "environment variables"
+					  " or -x/--proxy and --noproxy arguments:"));
+	printf(" %s\n",
+		   _("Checked environment variables: all_proxy, http_proxy, https_proxy, no_proxy"));
+	printf(" %s\n",
+		   _("Environment variables can also be given in uppercase, but the lowercase ones will "
+			 "take predence if both are defined."));
+	printf(" %s\n",
+		   _("The environment variables are overwritten by -x/--proxy and --noproxy arguments:"));
 	printf(" %s\n", _("all_proxy/ALL_PROXY environment variables are read first, but protocol "
-					"specific environment variables override them."));
-	printf(" %s\n", _("If SSL is enabled and used, https_proxy/HTTPS_PROXY will be checked and overwrite "
-			"http_proxy/HTTPS_PROXY."));
-	printf(" %s\n", _("Curl accepts proxies using http, https, socks4, socks4a, socks5 and socks5h schemes."));
-	printf(" %s\n", _("http_proxy=http://192.168.100.35:3128 ./check_curl -H www.monitoring-plugins.org"));
-	printf(" %s\n", _("http_proxy=http://used.proxy.com HTTP_PROXY=http://ignored.proxy.com ./check_curl -H www.monitoring-plugins.org"));
+					  "specific environment variables override them."));
+	printf(" %s\n",
+		   _("If SSL is enabled and used, https_proxy/HTTPS_PROXY will be checked and overwrite "
+			 "http_proxy/HTTPS_PROXY."));
+	printf(
+		" %s\n",
+		_("Curl accepts proxies using http, https, socks4, socks4a, socks5 and socks5h schemes."));
+	printf(" %s\n",
+		   _("http_proxy=http://192.168.100.35:3128 ./check_curl -H www.monitoring-plugins.org"));
+	printf(" %s\n", _("http_proxy=http://used.proxy.com HTTP_PROXY=http://ignored.proxy.com "
+					  "./check_curl -H www.monitoring-plugins.org"));
 	printf(" %s\n", _("  Lowercase http_proxy takes predence over uppercase HTTP_PROXY"));
 	printf(" %s\n", _("./check_curl -H www.monitoring-plugins.org -x http://192.168.100.35:3128"));
-	printf(" %s\n", _("http_proxy=http://unused.proxy1.com HTTP_PROXY=http://unused.proxy2.com ./check_curl "
-			"-H www.monitoring-plugins.org --proxy http://used.proxy"));
-	printf(" %s\n", _("  Proxy specified by --proxy overrides any proxy specified by environment variable."));
+	printf(" %s\n",
+		   _("http_proxy=http://unused.proxy1.com HTTP_PROXY=http://unused.proxy2.com ./check_curl "
+			 "-H www.monitoring-plugins.org --proxy http://used.proxy"));
+	printf(
+		" %s\n",
+		_("  Proxy specified by --proxy overrides any proxy specified by environment variable."));
 	printf(" %s\n", _("  Curl uses port 1080 by default as port is not specified"));
-	printf(" %s\n", _("HTTPS_PROXY=http://192.168.100.35:3128 ./check_curl -H www.monitoring-plugins.org --ssl"));
+	printf(" %s\n", _("HTTPS_PROXY=http://192.168.100.35:3128 ./check_curl -H "
+					  "www.monitoring-plugins.org --ssl"));
 	printf(" %s\n", _("  HTTPS_PROXY is read as --ssl is toggled"));
-	printf(" %s\n", _("./check_curl -H www.monitoring-plugins.org --proxy socks5h://192.168.122.21"));
-	printf(" %s\n", _("./check_curl -H www.monitoring-plugins.org -x http://unused.proxy.com --noproxy '*'"));
+	printf(" %s\n",
+		   _("./check_curl -H www.monitoring-plugins.org --proxy socks5h://192.168.122.21"));
+	printf(
+		" %s\n",
+		_("./check_curl -H www.monitoring-plugins.org -x http://unused.proxy.com --noproxy '*'"));
 	printf(" %s\n", _("  Disabled proxy for all hosts by using '*' in no_proxy ."));
-	printf(" %s\n", _("NO_PROXY=www.monitoring-plugins.org ./check_curl -H www.monitoring-plugins.org -x http://unused.proxy.com"));
+	printf(" %s\n", _("NO_PROXY=www.monitoring-plugins.org ./check_curl -H "
+					  "www.monitoring-plugins.org -x http://unused.proxy.com"));
 	printf(" %s\n", _("  Exact matches with the hostname/address work."));
-	printf(" %s\n", _("no_proxy=192.168.178.0/24 ./check_curl -I 192.168.178.10 -x http://proxy.acme.org"));
-	printf(" %s\n", _("no_proxy=acme.org ./check_curl -H nonpublic.internalwebapp.acme.org -x http://proxy.acme.org"));
-	printf(" %s\n", _("  Do not use proxy when accessing internal domains/addresses, but use a default proxy when accessing public web."));
-	printf(" %s\n", _("  IMPORTANT: Check_curl can not always determine whether itself or the proxy will "
-		"resolve a hostname before sending a request and getting an answer."
-		"This can lead to DNS resolvation issues if hostname is only resolvable over proxy."));
+	printf(" %s\n",
+		   _("no_proxy=192.168.178.0/24 ./check_curl -I 192.168.178.10 -x http://proxy.acme.org"));
+	printf(" %s\n", _("no_proxy=acme.org ./check_curl -H nonpublic.internalwebapp.acme.org -x "
+					  "http://proxy.acme.org"));
+	printf(" %s\n", _("  Do not use proxy when accessing internal domains/addresses, but use a "
+					  "default proxy when accessing public web."));
+	printf(" %s\n",
+		   _("  IMPORTANT: Check_curl can not always determine whether itself or the proxy will "
+			 "resolve a hostname before sending a request and getting an answer."
+			 "This can lead to DNS resolvation issues if hostname is only resolvable over proxy."));
 	printf(" %s\n", _("Legacy proxy requests in check_http style still work:"));
 	printf(" %s\n", _("check_curl -I 192.168.100.35 -p 3128 -u http://www.monitoring-plugins.org/ "
 					  "-H www.monitoring-plugins.org"));
diff --git a/plugins/check_curl.d/check_curl_helpers.c b/plugins/check_curl.d/check_curl_helpers.c
index 4372dc0b..f23dbdb7 100644
--- a/plugins/check_curl.d/check_curl_helpers.c
+++ b/plugins/check_curl.d/check_curl_helpers.c
@@ -60,8 +60,8 @@ check_curl_configure_curl(const check_curl_static_curl_config config,
 	result.curl_state.curl_easy_initialized = true;
 
 	if (verbose >= 1) {
-		handle_curl_option_return_code(curl_easy_setopt(result.curl_state.curl, CURLOPT_VERBOSE, 1L),
-									   "CURLOPT_VERBOSE");
+		handle_curl_option_return_code(
+			curl_easy_setopt(result.curl_state.curl, CURLOPT_VERBOSE, 1L), "CURLOPT_VERBOSE");
 	}
 
 	/* print everything on stdout like check_http would do */
@@ -120,21 +120,23 @@ check_curl_configure_curl(const check_curl_static_curl_config config,
 		"CURLOPT_TIMEOUT");
 
 	/* set proxy */
-	/* http(s) proxy can either be given from the command line, or taken from environment variables */
+	/* http(s) proxy can either be given from the command line, or taken from environment variables
+	 */
 	/* socks4(a) / socks5(h) proxy should be given using the command line */
 
 	/* first source to check is the environment variables */
-	/* lower case proxy environment variables are almost always accepted, while some programs also checking
-	uppercase ones. discover both, but take the lowercase one if both are present */
+	/* lower case proxy environment variables are almost always accepted, while some programs also
+	checking uppercase ones. discover both, but take the lowercase one if both are present */
 
-	/* extra information: libcurl does not discover the uppercase version HTTP_PROXY due to security reasons */
+	/* extra information: libcurl does not discover the uppercase version HTTP_PROXY due to security
+	 * reasons */
 	/* https://github.com/curl/curl/blob/d445f2d930ae701039518d695481ee53b8490521/lib/url.c#L1987 */
 
-	/* first environment variable to read is all_proxy. it can be overridden by protocol specific environment variables */
-	char *all_proxy_env, *all_proxy_uppercase_env;
-	all_proxy_env = getenv("all_proxy");
-	all_proxy_uppercase_env = getenv("ALL_PROXY");
-	if (all_proxy_env != NULL && strlen(all_proxy_env)){
+	/* first environment variable to read is all_proxy. it can be overridden by protocol specific
+	 * environment variables */
+	char *all_proxy_env = getenv("all_proxy");
+	char *all_proxy_uppercase_env = getenv("ALL_PROXY");
+	if (all_proxy_env != NULL && strlen(all_proxy_env)) {
 		working_state.curlopt_proxy = strdup(all_proxy_env);
 		if (all_proxy_uppercase_env != NULL && verbose >= 1) {
 			printf("* cURL ignoring environment variable 'ALL_PROXY' as 'all_proxy' is set\n");
@@ -143,15 +145,16 @@ check_curl_configure_curl(const check_curl_static_curl_config config,
 		working_state.curlopt_proxy = strdup(all_proxy_uppercase_env);
 	}
 
-	/* second environment variable to read is http_proxy. only set curlopt_proxy if ssl is not toggled */
-	char *http_proxy_env, *http_proxy_uppercase_env;
-	http_proxy_env = getenv("http_proxy");
-	http_proxy_uppercase_env = getenv("HTTP_PROXY");
-	if (!working_state.use_ssl){
+	/* second environment variable to read is http_proxy. only set curlopt_proxy if ssl is not
+	 * toggled */
+	char *http_proxy_env = getenv("http_proxy");
+	char *http_proxy_uppercase_env = getenv("HTTP_PROXY");
+	if (!working_state.use_ssl) {
 		if (http_proxy_env != NULL && strlen(http_proxy_env) > 0) {
 			working_state.curlopt_proxy = strdup(http_proxy_env);
 			if (http_proxy_uppercase_env != NULL && verbose >= 1) {
-				printf("* cURL ignoring environment variable 'HTTP_PROXY' as 'http_proxy' is set\n");
+				printf(
+					"* cURL ignoring environment variable 'HTTP_PROXY' as 'http_proxy' is set\n");
 			}
 		} else if (http_proxy_uppercase_env != NULL && strlen(http_proxy_uppercase_env) > 0) {
 			working_state.curlopt_proxy = strdup(http_proxy_uppercase_env);
@@ -159,30 +162,31 @@ check_curl_configure_curl(const check_curl_static_curl_config config,
 	}
 #ifdef LIBCURL_FEATURE_SSL
 	/* optionally read https_proxy environment variable and set curlopt_proxy if ssl is toggled */
-	char *https_proxy_env, *https_proxy_uppercase_env;
-	https_proxy_env = getenv("https_proxy");
-	https_proxy_uppercase_env = getenv("HTTPS_PROXY");
+	char *https_proxy_env = getenv("https_proxy");
+	char *https_proxy_uppercase_env = getenv("HTTPS_PROXY");
 	if (working_state.use_ssl) {
 		if (https_proxy_env != NULL && strlen(https_proxy_env) > 0) {
 			working_state.curlopt_proxy = strdup(https_proxy_env);
 			if (https_proxy_uppercase_env != NULL && verbose >= 1) {
-				printf("* cURL ignoring environment variable 'HTTPS_PROXY' as 'https_proxy' is set\n");
+				printf(
+					"* cURL ignoring environment variable 'HTTPS_PROXY' as 'https_proxy' is set\n");
 			}
-		}
-		else if (https_proxy_uppercase_env != NULL && strlen(https_proxy_uppercase_env) >= 0) {
+		} else if (https_proxy_uppercase_env != NULL) {
 			working_state.curlopt_proxy = strdup(https_proxy_uppercase_env);
 		}
 	}
 #endif /* LIBCURL_FEATURE_SSL */
 
-	/* second source to check for proxies is command line argument, overwriting the environment variables */
+	/* second source to check for proxies is command line argument, overwriting the environment
+	 * variables */
 	if (strlen(config.proxy) > 0) {
 		working_state.curlopt_proxy = strdup(config.proxy);
 	}
 
-	if (working_state.curlopt_proxy != NULL && strlen(working_state.curlopt_proxy)){
+	if (working_state.curlopt_proxy != NULL && strlen(working_state.curlopt_proxy)) {
 		handle_curl_option_return_code(
-			curl_easy_setopt(result.curl_state.curl, CURLOPT_PROXY, working_state.curlopt_proxy), "CURLOPT_PROXY");
+			curl_easy_setopt(result.curl_state.curl, CURLOPT_PROXY, working_state.curlopt_proxy),
+			"CURLOPT_PROXY");
 		if (verbose >= 1) {
 			printf("* curl CURLOPT_PROXY: %s\n", working_state.curlopt_proxy);
 		}
@@ -190,34 +194,35 @@ check_curl_configure_curl(const check_curl_static_curl_config config,
 
 	/* set no_proxy */
 	/* first source to check is environment variables */
-	char *no_proxy_env, *no_proxy_uppercase_env;
-	no_proxy_env = getenv("no_proxy");
-	no_proxy_uppercase_env = getenv("NO_PROXY");
-	if (no_proxy_env != NULL && strlen(no_proxy_env)){
+	char *no_proxy_env = getenv("no_proxy");
+	char *no_proxy_uppercase_env = getenv("NO_PROXY");
+	if (no_proxy_env != NULL && strlen(no_proxy_env)) {
 		working_state.curlopt_noproxy = strdup(no_proxy_env);
-		if (no_proxy_uppercase_env != NULL && verbose >= 1){
+		if (no_proxy_uppercase_env != NULL && verbose >= 1) {
 			printf("* cURL ignoring environment variable 'NO_PROXY' as 'no_proxy' is set\n");
 		}
-	}else if (no_proxy_uppercase_env != NULL && strlen(no_proxy_uppercase_env) > 0){
+	} else if (no_proxy_uppercase_env != NULL && strlen(no_proxy_uppercase_env) > 0) {
 		working_state.curlopt_noproxy = strdup(no_proxy_uppercase_env);
 	}
 
-	/* second source to check for no_proxy is command line argument, overwriting the environment variables */
+	/* second source to check for no_proxy is command line argument, overwriting the environment
+	 * variables */
 	if (strlen(config.no_proxy) > 0) {
 		working_state.curlopt_noproxy = strdup(config.no_proxy);
 	}
 
-	if ( working_state.curlopt_noproxy != NULL && strlen(working_state.curlopt_noproxy)){
-		handle_curl_option_return_code(
-			curl_easy_setopt(result.curl_state.curl, CURLOPT_NOPROXY, working_state.curlopt_noproxy), "CURLOPT_NOPROXY");
+	if (working_state.curlopt_noproxy != NULL && strlen(working_state.curlopt_noproxy)) {
+		handle_curl_option_return_code(curl_easy_setopt(result.curl_state.curl, CURLOPT_NOPROXY,
+														working_state.curlopt_noproxy),
+									   "CURLOPT_NOPROXY");
 		if (verbose >= 1) {
 			printf("* curl CURLOPT_NOPROXY: %s\n", working_state.curlopt_noproxy);
 		}
 	}
 
-	int proxy_resolves_hostname = determine_hostname_resolver(working_state, config);
+	bool have_local_resolution = hostname_gets_resolved_locally(working_state);
 	if (verbose >= 1) {
-		printf("* proxy_resolves_hostname: %d\n", proxy_resolves_hostname);
+		printf("* have local name resolution: %s\n", (have_local_resolution ? "true": "false"));
 	}
 
 	/* enable haproxy protocol */
@@ -231,7 +236,7 @@ check_curl_configure_curl(const check_curl_static_curl_config config,
 	/* host_name, only required for ssl, because we use the host_name later on to make SNI happy */
 	char dnscache[DEFAULT_BUFFER_SIZE];
 	char addrstr[DEFAULT_BUFFER_SIZE / 2];
-	if (working_state.use_ssl && working_state.host_name != NULL && !proxy_resolves_hostname ) {
+	if (working_state.use_ssl && working_state.host_name != NULL && !have_local_resolution) {
 		char *tmp_mod_address;
 
 		/* lookup_host() requires an IPv6 address without the brackets. */
@@ -682,7 +687,7 @@ char *get_header_value(const struct phr_header *headers, const size_t nof_header
 	return NULL;
 }
 
-check_curl_working_state check_curl_working_state_init() {
+check_curl_working_state check_curl_working_state_init(void) {
 	check_curl_working_state result = {
 		.server_address = NULL,
 		.server_url = DEFAULT_SERVER_URL,
@@ -699,7 +704,7 @@ check_curl_working_state check_curl_working_state_init() {
 	return result;
 }
 
-check_curl_config check_curl_config_init() {
+check_curl_config check_curl_config_init(void) {
 	check_curl_config tmp = {
 		.initial_config = check_curl_working_state_init(),
 
@@ -1404,10 +1409,10 @@ char *fmt_url(check_curl_working_state workingState) {
 	return url;
 }
 
-int determine_hostname_resolver(const check_curl_working_state working_state, const check_curl_static_curl_config config){
+bool hostname_gets_resolved_locally(const check_curl_working_state working_state) {
 	char *host_name_display = "NULL";
 	unsigned long host_name_len = 0;
-	if( working_state.host_name){
+	if (working_state.host_name) {
 		host_name_len = strlen(working_state.host_name);
 		host_name_display = working_state.host_name;
 	}
@@ -1415,8 +1420,11 @@ int determine_hostname_resolver(const check_curl_working_state working_state, co
 	/* IPv4 or IPv6 version of the address */
 	char *server_address_clean = strdup(working_state.server_address);
 	/* server address might be a full length ipv6 address encapsulated in square brackets */
-	if ((strnlen(working_state.server_address, MAX_IPV4_HOSTLENGTH) > 2) && (working_state.server_address[0] == '[') && (working_state.server_address[strlen(working_state.server_address)-1] == ']') ) {
-		server_address_clean = strndup( working_state.server_address + 1, strlen(working_state.server_address) - 2);
+	if ((strnlen(working_state.server_address, MAX_IPV4_HOSTLENGTH) > 2) &&
+		(working_state.server_address[0] == '[') &&
+		(working_state.server_address[strlen(working_state.server_address) - 1] == ']')) {
+		server_address_clean =
+			strndup(working_state.server_address + 1, strlen(working_state.server_address) - 2);
 	}
 
 	/* check curlopt_noproxy option first */
@@ -1427,79 +1435,90 @@ int determine_hostname_resolver(const check_curl_working_state working_state, co
 	IPv4 or IPv6 CIDR regions e.g 10.241.0.0/16 , abcd:ef01:2345::/48 ,
 	direct hostnames e.g example.com, google.de */
 
-	if (working_state.curlopt_noproxy != NULL){
-		char* curlopt_noproxy_copy = strdup( working_state.curlopt_noproxy);
-		char* noproxy_item = strtok(curlopt_noproxy_copy, ",");
-		while(noproxy_item != NULL){
+	if (working_state.curlopt_noproxy != NULL) {
+		char *curlopt_noproxy_copy = strdup(working_state.curlopt_noproxy);
+		char *noproxy_item = strtok(curlopt_noproxy_copy, ",");
+		while (noproxy_item != NULL) {
 			unsigned long noproxy_item_len = strlen(noproxy_item);
 
 			/* According to the CURLOPT_NOPROXY documentation: */
 			/* https://curl.se/libcurl/c/CURLOPT_NOPROXY.html */
-			/* The only wildcard available is a single * character, which matches all hosts, and effectively disables the proxy. */
-			if ( strlen(noproxy_item) == 1 && noproxy_item[0] == '*'){
-				if (verbose >= 1){
-					printf("* noproxy includes '*' which disables proxy for all host name incl. : %s / server address incl. : %s\n", host_name_display , server_address_clean);
+			/* The only wildcard available is a single * character, which matches all hosts, and
+			 * effectively disables the proxy. */
+			if (strlen(noproxy_item) == 1 && noproxy_item[0] == '*') {
+				if (verbose >= 1) {
+					printf("* noproxy includes '*' which disables proxy for all host name incl. : "
+						   "%s / server address incl. : %s\n",
+						   host_name_display, server_address_clean);
 				}
 				free(curlopt_noproxy_copy);
 				free(server_address_clean);
-				return 0;
+				return true;
 			}
 
 			/* direct comparison with the server_address */
-			if( server_address_clean != NULL && strlen(server_address_clean) == strlen(noproxy_item) && strcmp(server_address_clean, noproxy_item) == 0){
-				if (verbose >= 1){
+			if (server_address_clean != NULL &&
+				strlen(server_address_clean) == strlen(noproxy_item) &&
+				strcmp(server_address_clean, noproxy_item) == 0) {
+				if (verbose >= 1) {
 					printf("* server_address is in the no_proxy list: %s\n", noproxy_item);
 				}
 				free(curlopt_noproxy_copy);
 				free(server_address_clean);
-				return 0;
+				return true;
 			}
 
 			/* direct comparison with the host_name */
-			if( working_state.host_name != NULL && host_name_len == noproxy_item_len && strcmp(working_state.host_name, noproxy_item) == 0){
-				if (verbose >= 1){
+			if (working_state.host_name != NULL && host_name_len == noproxy_item_len &&
+				strcmp(working_state.host_name, noproxy_item) == 0) {
+				if (verbose >= 1) {
 					printf("* host_name is in the no_proxy list: %s\n", noproxy_item);
 				}
 				free(curlopt_noproxy_copy);
 				free(server_address_clean);
-				return 0;
+				return true;
 			}
 
-			/* check if hostname is a subdomain of the item, e.g www.example.com when token is example.com */
-			/* subdomain1.acme.com will not will use a proxy if you only specify 'acme' in the noproxy */
+			/* check if hostname is a subdomain of the item, e.g www.example.com when token is
+			 * example.com */
+			/* subdomain1.acme.com will not will use a proxy if you only specify 'acme' in the
+			 * noproxy */
 			/* check if noproxy_item is a suffix */
 			/* check if the character just before the suffix is '.' */
-			if( working_state.host_name != NULL && host_name_len > noproxy_item_len){
+			if (working_state.host_name != NULL && host_name_len > noproxy_item_len) {
 				unsigned long suffix_start_idx = host_name_len - noproxy_item_len;
-				if (strcmp(working_state.host_name + suffix_start_idx, noproxy_item ) == 0 && working_state.host_name[suffix_start_idx-1] == '.' ){
-					if (verbose >= 1){
-						printf("* host_name: %s is a subdomain of the no_proxy list item: %s\n", working_state.host_name , noproxy_item);
+				if (strcmp(working_state.host_name + suffix_start_idx, noproxy_item) == 0 &&
+					working_state.host_name[suffix_start_idx - 1] == '.') {
+					if (verbose >= 1) {
+						printf("* host_name: %s is a subdomain of the no_proxy list item: %s\n",
+							   working_state.host_name, noproxy_item);
 					}
 					free(curlopt_noproxy_copy);
 					free(server_address_clean);
-					return 0;
+					return true;
 				}
 			}
 
 			// noproxy_item could be a CIDR IP range
-			if( server_address_clean != NULL && strlen(server_address_clean)){
+			if (server_address_clean != NULL && strlen(server_address_clean)) {
+				ip_addr_inside ip_addr_inside_cidr_ret =
+					ip_addr_inside_cidr(noproxy_item, server_address_clean);
 
-				int ip_addr_inside_cidr_ret = ip_addr_inside_cidr(noproxy_item, server_address_clean);
-
-				switch(ip_addr_inside_cidr_ret){
-				case 1:
-					return 0;
-					break;
-				case 0:
-					if(verbose >= 1){
-						printf("server address: %s is not inside IP cidr: %s\n", server_address_clean, noproxy_item);
+				if (ip_addr_inside_cidr_ret.error == NO_ERROR) {
+					if (ip_addr_inside_cidr_ret.inside) {
+						return true;
+					} else {
+						if (verbose >= 1) {
+							printf("server address: %s is not inside IP cidr: %s\n",
+								   server_address_clean, noproxy_item);
+						}
 					}
-					break;
-				case -1:
-					if(verbose >= 1){
-						printf("could not fully determine if server address: %s is inside the IP cidr: %s\n", server_address_clean, noproxy_item);
+				} else {
+					if (verbose >= 1) {
+						printf("could not fully determine if server address: %s is inside the IP "
+							   "cidr: %s\n",
+							   server_address_clean, noproxy_item);
 					}
-					break;
 				}
 			}
 
@@ -1509,82 +1528,97 @@ int determine_hostname_resolver(const check_curl_working_state working_state, co
 		free(curlopt_noproxy_copy);
 	}
 
-	if (working_state.curlopt_proxy != NULL){
+	if (working_state.curlopt_proxy != NULL) {
 		// Libcurl documentation
-		// Setting the proxy string to "" (an empty string) explicitly disables the use of a proxy, even if there is an environment variable set for it.
-		if ( strlen(working_state.curlopt_proxy) == 0){
-			return 0;
+		// Setting the proxy string to "" (an empty string) explicitly disables the use of a proxy,
+		// even if there is an environment variable set for it.
+		if (strlen(working_state.curlopt_proxy) == 0) {
+			return true;
 		}
 
-		if ( strncmp( working_state.curlopt_proxy, "http://", 7) == 0){
-			if (verbose >= 1){
-				printf("* proxy scheme is http, proxy: %s resolves host: %s or server_address: %s\n", working_state.curlopt_proxy, host_name_display, server_address_clean);
+		if (strncmp(working_state.curlopt_proxy, "http://", 7) == 0) {
+			if (verbose >= 1) {
+				printf(
+					"* proxy scheme is http, proxy: %s resolves host: %s or server_address: %s\n",
+					working_state.curlopt_proxy, host_name_display, server_address_clean);
 			}
 			free(server_address_clean);
-			return 1;
+			return false;
 		}
 
-		if ( strncmp( working_state.curlopt_proxy, "https://", 8) == 0){
-			if (verbose >= 1){
-				printf("* proxy scheme is https, proxy: %s resolves host: %s or server_address: %s\n", working_state.curlopt_proxy, host_name_display, server_address_clean);
+		if (strncmp(working_state.curlopt_proxy, "https://", 8) == 0) {
+			if (verbose >= 1) {
+				printf(
+					"* proxy scheme is https, proxy: %s resolves host: %s or server_address: %s\n",
+					working_state.curlopt_proxy, host_name_display, server_address_clean);
 			}
 			free(server_address_clean);
-			return 1;
+			return false;
 		}
 
-		if ( strncmp( working_state.curlopt_proxy, "socks4://", 9) == 0){
-			if (verbose >= 1){
-				printf("* proxy scheme is socks, proxy: %s does not resolve host: %s or server_address: %s\n", working_state.curlopt_proxy, host_name_display, server_address_clean);
+		if (strncmp(working_state.curlopt_proxy, "socks4://", 9) == 0) {
+			if (verbose >= 1) {
+				printf("* proxy scheme is socks, proxy: %s does not resolve host: %s or "
+					   "server_address: %s\n",
+					   working_state.curlopt_proxy, host_name_display, server_address_clean);
 			}
 			free(server_address_clean);
-			return 0;
+			return true;
 		}
 
-		if ( strncmp( working_state.curlopt_proxy, "socks4a://", 10) == 0){
-			if (verbose >= 1){
-				printf("* proxy scheme is socks4a, proxy: %s resolves host: %s or server_address: %s\n", working_state.curlopt_proxy, host_name_display, server_address_clean);
+		if (strncmp(working_state.curlopt_proxy, "socks4a://", 10) == 0) {
+			if (verbose >= 1) {
+				printf("* proxy scheme is socks4a, proxy: %s resolves host: %s or server_address: "
+					   "%s\n",
+					   working_state.curlopt_proxy, host_name_display, server_address_clean);
 			}
 			free(server_address_clean);
-			return 1;
+			return false;
 		}
 
-		if ( strncmp( working_state.curlopt_proxy, "socks5://", 9) == 0){
-			if (verbose >= 1){
-				printf("* proxy scheme is socks5, proxy: %s does not resolve host: %s or server_address: %s\n", working_state.curlopt_proxy, host_name_display, server_address_clean);
+		if (strncmp(working_state.curlopt_proxy, "socks5://", 9) == 0) {
+			if (verbose >= 1) {
+				printf("* proxy scheme is socks5, proxy: %s does not resolve host: %s or "
+					   "server_address: %s\n",
+					   working_state.curlopt_proxy, host_name_display, server_address_clean);
 			}
 			free(server_address_clean);
-			return 0;
+			return true;
 		}
 
-		if ( strncmp( working_state.curlopt_proxy, "socks5h://", 10) == 0){
-			if (verbose >= 1){
-				printf("* proxy scheme is socks5h, proxy: %s resolves host: %s or server_address: %s\n", working_state.curlopt_proxy, host_name_display, server_address_clean);
+		if (strncmp(working_state.curlopt_proxy, "socks5h://", 10) == 0) {
+			if (verbose >= 1) {
+				printf("* proxy scheme is socks5h, proxy: %s resolves host: %s or server_address: "
+					   "%s\n",
+					   working_state.curlopt_proxy, host_name_display, server_address_clean);
 			}
 			free(server_address_clean);
-			return 1;
+			return false;
 		}
 
 		// Libcurl documentation:
-		// Without a scheme prefix, CURLOPT_PROXYTYPE can be used to specify which kind of proxy the string identifies.
-		// We do not set this value
-		// Without a scheme, it is treated as an http proxy
+		// Without a scheme prefix, CURLOPT_PROXYTYPE can be used to specify which kind of proxy the
+		// string identifies. We do not set this value Without a scheme, it is treated as an http
+		// proxy
 
-		return 1;
+		return false;
 	}
 
-	if (verbose >= 1){
-		printf("* proxy scheme is unknown/unavailable, no proxy is assumed for host: %s or server_address: %s\n", host_name_display, server_address_clean);
+	if (verbose >= 1) {
+		printf("* proxy scheme is unknown/unavailable, no proxy is assumed for host: %s or "
+			   "server_address: %s\n",
+			   host_name_display, server_address_clean);
 	}
 
 	free(server_address_clean);
 	return 0;
 }
 
-int ip_addr_inside_cidr(const char* cidr_region_or_ip_addr, const char* target_ip){
+ip_addr_inside ip_addr_inside_cidr(const char *cidr_region_or_ip_addr, const char *target_ip) {
 	unsigned int slash_count = 0;
 	unsigned int last_slash_idx = 0;
-	for(size_t i = 0; i < strlen(cidr_region_or_ip_addr); i++){
-		if(cidr_region_or_ip_addr[i] == '/'){
+	for (size_t i = 0; i < strlen(cidr_region_or_ip_addr); i++) {
+		if (cidr_region_or_ip_addr[i] == '/') {
 			slash_count++;
 			last_slash_idx = (unsigned int)i;
 		}
@@ -1592,48 +1626,67 @@ int ip_addr_inside_cidr(const char* cidr_region_or_ip_addr, const char* target_i
 
 	char *cidr_ip_part = NULL;
 	int prefix_length = 0;
+	ip_addr_inside result = {
+		.inside = false,
+		.error = NO_ERROR,
+	};
 
 	if (slash_count == 0) {
 		cidr_ip_part = strdup(cidr_region_or_ip_addr);
-		if (!cidr_ip_part) return -1;
+		if (!cidr_ip_part) {
+			result.error = FAILED_STRDUP;
+			return result;
+		}
 	} else if (slash_count == 1) {
 		cidr_ip_part = strndup(cidr_region_or_ip_addr, last_slash_idx);
-		if (!cidr_ip_part) return -1;
+		if (!cidr_ip_part) {
+			result.error = FAILED_STRDUP;
+			return result;
+		}
 
 		errno = 0;
 		long long tmp = strtoll(cidr_region_or_ip_addr + last_slash_idx + 1, NULL, 10);
 		if (errno == ERANGE) {
 			if (verbose >= 1) {
-				printf("cidr_region_or_ip: %s , could not parse subnet length\n", cidr_region_or_ip_addr);
+				printf("cidr_region_or_ip: %s , could not parse subnet length\n",
+					   cidr_region_or_ip_addr);
 			}
 			free(cidr_ip_part);
-			return -1;
+			result.error = COULD_NOT_PARSE_SUBNET_LENGTH;
+			return result;
 		}
 		prefix_length = (int)tmp;
 	} else {
-		printf("cidr_region_or_ip: %s , has %d number of '/' characters, is not a valid cidr_region or IP\n", cidr_region_or_ip_addr, slash_count);
-		return -1;
+		if (verbose >= 1) {
+			printf("cidr_region_or_ip: %s , has %d number of '/' characters, is not a valid "
+				   "cidr_region or IP\n",
+				   cidr_region_or_ip_addr, slash_count);
+		}
+		result.error = CIDR_REGION_INVALID;
+		return result;
 	}
 
 	int cidr_addr_family, target_addr_family;
-	if (strchr(cidr_ip_part, ':')){
+	if (strchr(cidr_ip_part, ':')) {
 		cidr_addr_family = AF_INET6;
 	} else {
 		cidr_addr_family = AF_INET;
 	}
 
-	if (strchr(target_ip, ':')){
+	if (strchr(target_ip, ':')) {
 		target_addr_family = AF_INET6;
 	} else {
 		target_addr_family = AF_INET;
 	}
 
-	if (cidr_addr_family != target_addr_family){
-		if (verbose >= 1){
-			printf("cidr address: %s and target ip address: %s have different address families\n", cidr_ip_part, target_ip);
+	if (cidr_addr_family != target_addr_family) {
+		if (verbose >= 1) {
+			printf("cidr address: %s and target ip address: %s have different address families\n",
+				   cidr_ip_part, target_ip);
 		}
 		free(cidr_ip_part);
-		return 0;
+		result.inside = false;
+		return result;
 	}
 
 	// If no prefix is given, treat the cidr as a single address (full-length prefix)
@@ -1644,14 +1697,17 @@ int ip_addr_inside_cidr(const char* cidr_region_or_ip_addr, const char* target_i
 	int max_bits = (cidr_addr_family == AF_INET) ? 32u : 128u;
 	if (prefix_length < 0 || prefix_length > max_bits) {
 		if (verbose >= 1) {
-			printf("cidr_region_or_ip: %s has invalid prefix length: %u\n", cidr_region_or_ip_addr, prefix_length);
+			printf("cidr_region_or_ip: %s has invalid prefix length: %u\n", cidr_region_or_ip_addr,
+				   prefix_length);
 		}
 		free(cidr_ip_part);
-		return -1;
+		result.error = CIDR_REGION_INVALID_PREFIX;
+		return result;
 	}
 
-	if (verbose >= 1){
-		printf("cidr_region_or_ip: %s , has prefix length: %u\n", cidr_region_or_ip_addr, prefix_length);
+	if (verbose >= 1) {
+		printf("cidr_region_or_ip: %s , has prefix length: %u\n", cidr_region_or_ip_addr,
+			   prefix_length);
 	}
 
 	int inet_pton_rc;
@@ -1659,7 +1715,6 @@ int ip_addr_inside_cidr(const char* cidr_region_or_ip_addr, const char* target_i
 	uint8_t *target_bytes = NULL;
 	uint8_t cidr_buf[16];
 	uint8_t target_buf[16];
-	size_t total_bytes = 0;
 
 	if (cidr_addr_family == AF_INET) {
 		struct in_addr cidr_ipv4;
@@ -1667,49 +1722,55 @@ int ip_addr_inside_cidr(const char* cidr_region_or_ip_addr, const char* target_i
 		inet_pton_rc = inet_pton(AF_INET, cidr_ip_part, &cidr_ipv4);
 		if (inet_pton_rc != 1) {
 			if (verbose >= 1) {
-				printf("ip string: %s contains characters not valid for its address family: IPv4\n", cidr_ip_part);
+				printf("ip string: %s contains characters not valid for its address family: IPv4\n",
+					   cidr_ip_part);
 			}
 			free(cidr_ip_part);
-			return -1;
+			result.error = IP_CONTAINS_INVALID_CHARACTERS;
+			return result;
 		}
 		inet_pton_rc = inet_pton(AF_INET, target_ip, &target_ipv4);
 		if (inet_pton_rc != 1) {
 			if (verbose >= 1) {
-				printf("ip string: %s contains characters not valid for its address family: IPv4\n", target_ip);
+				printf("ip string: %s contains characters not valid for its address family: IPv4\n",
+					   target_ip);
 			}
 			free(cidr_ip_part);
-			return -1;
+			result.error = IP_CONTAINS_INVALID_CHARACTERS;
+			return result;
 		}
 		// copy the addresses in network byte order to a buffer for comparison
 		memcpy(cidr_buf, &cidr_ipv4.s_addr, 4);
 		memcpy(target_buf, &target_ipv4.s_addr, 4);
 		cidr_bytes = cidr_buf;
 		target_bytes = target_buf;
-		total_bytes = 4;
 	} else {
 		struct in6_addr cidr_ipv6;
 		struct in6_addr target_ipv6;
 		inet_pton_rc = inet_pton(AF_INET6, cidr_ip_part, &cidr_ipv6);
 		if (inet_pton_rc != 1) {
 			if (verbose >= 1) {
-				printf("ip string: %s contains characters not valid for its address family: IPv6\n", cidr_ip_part);
+				printf("ip string: %s contains characters not valid for its address family: IPv6\n",
+					   cidr_ip_part);
 			}
 			free(cidr_ip_part);
-			return -1;
+			result.error = IP_CONTAINS_INVALID_CHARACTERS;
+			return result;
 		}
 		inet_pton_rc = inet_pton(AF_INET6, target_ip, &target_ipv6);
 		if (inet_pton_rc != 1) {
 			if (verbose >= 1) {
-				printf("ip string: %s contains characters not valid for its address family: IPv6\n", target_ip);
+				printf("ip string: %s contains characters not valid for its address family: IPv6\n",
+					   target_ip);
 			}
 			free(cidr_ip_part);
-			return -1;
+			result.error = IP_CONTAINS_INVALID_CHARACTERS;
+			return result;
 		}
 		memcpy(cidr_buf, &cidr_ipv6, 16);
 		memcpy(target_buf, &target_ipv6, 16);
 		cidr_bytes = cidr_buf;
 		target_bytes = target_buf;
-		total_bytes = 16;
 	}
 
 	int prefix_bytes = prefix_length / 8;
@@ -1718,10 +1779,13 @@ int ip_addr_inside_cidr(const char* cidr_region_or_ip_addr, const char* target_i
 	if (prefix_bytes > 0) {
 		if (memcmp(cidr_bytes, target_bytes, (size_t)prefix_bytes) != 0) {
 			if (verbose >= 1) {
-				printf("the first %d bytes of the cidr_region_or_ip: %s and target_ip: %s are different\n", prefix_bytes, cidr_ip_part, target_ip);
+				printf("the first %d bytes of the cidr_region_or_ip: %s and target_ip: %s are "
+					   "different\n",
+					   prefix_bytes, cidr_ip_part, target_ip);
 			}
 			free(cidr_ip_part);
-			return 0;
+			result.inside = false;
+			return result;
 		}
 	}
 
@@ -1732,13 +1796,19 @@ int ip_addr_inside_cidr(const char* cidr_region_or_ip_addr, const char* target_i
 		uint8_t mask = (uint8_t)(0xFFu << (8 - prefix_bits));
 		if ((cidr_oct & mask) != (target_oct & mask)) {
 			if (verbose >= 1) {
-				printf("looking at the last %d bits of the prefix, cidr_region_or_ip(%s) byte is: %u and target_ip byte(%s) is: %u, applying bitmask: %02X returns different results\n", prefix_bits, cidr_ip_part, (unsigned)cidr_oct, target_ip, (unsigned)target_oct, mask);
+				printf("looking at the last %d bits of the prefix, cidr_region_or_ip(%s) byte is: "
+					   "%u and target_ip byte(%s) is: %u, applying bitmask: %02X returns different "
+					   "results\n",
+					   prefix_bits, cidr_ip_part, (unsigned)cidr_oct, target_ip,
+					   (unsigned)target_oct, mask);
 			}
 			free(cidr_ip_part);
-			return 0;
+			result.inside = false;
+			return result;
 		}
 	}
 
 	free(cidr_ip_part);
-	return 1;
+	result.inside = true;
+	return result;
 }
diff --git a/plugins/check_curl.d/check_curl_helpers.h b/plugins/check_curl.d/check_curl_helpers.h
index cc47bf9d..55df9bc1 100644
--- a/plugins/check_curl.d/check_curl_helpers.h
+++ b/plugins/check_curl.d/check_curl_helpers.h
@@ -127,11 +127,25 @@ mp_subcheck check_curl_certificate_checks(CURL *curl, X509 *cert, int warn_days_
 										  int crit_days_till_exp);
 char *fmt_url(check_curl_working_state workingState);
 
+/* determine_hostname_resolver determines if the host or the proxy resolves the target hostname
+returns RESOLVE_LOCALLY if requester resolves the hostname locally, RESOLVE_REMOTELY if proxy
+resolves the hostname */
+bool hostname_gets_resolved_locally(const check_curl_working_state working_state);
 
-/* function that will determine if the host or the proxy resolves the target hostname
-returns 0 if requester resolves the hostname locally, 1 if proxy resolves the hostname */
-int determine_hostname_resolver(const check_curl_working_state working_state, const check_curl_static_curl_config config);
-
-/* Checks if an IP is inside given CIDR region. Using /protocol_size or not specifying the prefix length performs an equality check. Supports both IPv4 and IPv6
-returns 1 if the target_ip address is inside the given cidr_region_or_ip_addr, 0 if its out. return codes < 0 mean an error has occurred. */
-int ip_addr_inside_cidr(const char* cidr_region_or_ip_addr, const char* target_ip);
+/* Checks if an IP is inside given CIDR region. Using /protocol_size or not specifying the prefix
+length performs an equality check. Supports both IPv4 and IPv6 returns 1 if the target_ip address is
+inside the given cidr_region_or_ip_addr, 0 if its out. return codes < 0 mean an error has occurred.
+*/
+typedef enum {
+	NO_ERROR,
+	FAILED_STRDUP,
+	COULD_NOT_PARSE_SUBNET_LENGTH,
+	CIDR_REGION_INVALID,
+	CIDR_REGION_INVALID_PREFIX,
+	IP_CONTAINS_INVALID_CHARACTERS,
+} ip_addr_inside_error_code;
+typedef struct {
+	bool inside;
+	ip_addr_inside_error_code error;
+} ip_addr_inside;
+ip_addr_inside ip_addr_inside_cidr(const char *cidr_region_or_ip_addr, const char *target_ip);
diff --git a/plugins/t/check_curl.t b/plugins/t/check_curl.t
index a8326f12..0f4d0de7 100644
--- a/plugins/t/check_curl.t
+++ b/plugins/t/check_curl.t
@@ -238,100 +238,100 @@ SKIP: {
 
     # Test if proxy works
     $res = NPTest->testCmd( "./$plugin -H $host_tcp_http --proxy http://$host_tcp_proxy:$port_tcp_proxy -v" );
-    like($res->output, qr/^\* proxy_resolves_hostname: 1/m, "proxy is used, there are no preventative measures ");
+    like($res->output, qr/^\* have local name resolution: false/m, "proxy is used, there are no preventative measures ");
     is( $res->return_code, 0, "Using proxy http://$host_tcp_proxy:$port_tcp_proxy to connect to $host_tcp_http works" );
 
     $res = NPTest->testCmd( "./$plugin -I $host_tcp_http_ipv4 --proxy http://$host_tcp_proxy:$port_tcp_proxy -v" );
-    like($res->output, qr/^\* proxy_resolves_hostname: 1/m, "proxy is used, there are no preventative measures ");
+    like($res->output, qr/^\* have local name resolution: false/m, "proxy is used, there are no preventative measures ");
     is( $res->return_code, 0, "Using proxy http://$host_tcp_proxy:$port_tcp_proxy to connect to $host_tcp_http_ipv4 works" );
 
     $res = NPTest->testCmd( "./$plugin -I $host_tcp_http_ipv6 --proxy http://$host_tcp_proxy:$port_tcp_proxy -v" );
-    like($res->output, qr/^\* proxy_resolves_hostname: 1/m, "proxy is used, there are no preventative measures ");
+    like($res->output, qr/^\* have local name resolution: false/m, "proxy is used, there are no preventative measures ");
     is( $res->return_code, 0, "Using proxy http://$host_tcp_proxy:$port_tcp_proxy to connect to $host_tcp_http_ipv6 works" );
 
     $res = NPTest->testCmd( "./$plugin -H $host_tcp_http2 --proxy http://$host_tcp_proxy:$port_tcp_proxy -v" );
-    like($res->output, qr/^\* proxy_resolves_hostname: 1/m, "proxy is used, there are no preventative measures ");
+    like($res->output, qr/^\* have local name resolution: false/m, "proxy is used, there are no preventative measures ");
     is( $res->return_code, 0, "Using proxy http://$host_tcp_proxy:$port_tcp_proxy to connect to $host_tcp_http2 works" );
 
     $res = NPTest->testCmd( "./$plugin -H $host_tcp_http_subdomain --proxy http://$host_tcp_proxy:$port_tcp_proxy -v" );
-    like($res->output, qr/^\* proxy_resolves_hostname: 1/m, "proxy is used, there are no preventative measures ");
+    like($res->output, qr/^\* have local name resolution: false/m, "proxy is used, there are no preventative measures ");
     is( $res->return_code, 0, "Using proxy http://$host_tcp_proxy:$port_tcp_proxy to connect to $host_tcp_http_subdomain works" );
 
     $res = NPTest->testCmd( "./$plugin -H $host_tls_http --proxy http://$host_tcp_proxy:$port_tcp_proxy -v" );
-    like($res->output, qr/^\* proxy_resolves_hostname: 1/m, "proxy is used, there are no preventative measures ");
+    like($res->output, qr/^\* have local name resolution: false/m, "proxy is used, there are no preventative measures ");
     is( $res->return_code, 0, "Using proxy http://$host_tcp_proxy:$port_tcp_proxy to connect to $host_tls_http works" );
 
     # Noproxy '*' should prevent using proxy in any setting, even if its specified
     $res = NPTest->testCmd( "./$plugin -H $host_tcp_http_subdomain --proxy http://$host_tcp_proxy:$port_tcp_proxy --noproxy \"\*\" -v" );
-    like($res->output, qr/^\* proxy_resolves_hostname: 0/m, "proxy is not used since noproxy has \"\*\" ");
+    like($res->output, qr/^\* have local name resolution: true/m, "proxy is not used since noproxy has \"\*\" ");
     is( $res->return_code, 0, "Should reach $host_tcp_http_subdomain with or without proxy." );
 
     $res = NPTest->testCmd( "./$plugin -I $host_tcp_http_ipv4 --proxy http://$host_tcp_proxy:$port_tcp_proxy --noproxy \"\*\" -v" );
-    like($res->output, qr/^\* proxy_resolves_hostname: 0/m, "proxy is not used since noproxy has \"\*\" ");
+    like($res->output, qr/^\* have local name resolution: true/m, "proxy is not used since noproxy has \"\*\" ");
     is( $res->return_code, 0, "Should reach $host_tcp_http_ipv4 with or without proxy." );
 
     $res = NPTest->testCmd( "./$plugin -I $host_tcp_http_ipv6 --proxy http://$host_tcp_proxy:$port_tcp_proxy --noproxy \"\*\" -v" );
-    like($res->output, qr/^\* proxy_resolves_hostname: 0/m, "proxy is not used since noproxy has \"\*\" ");
+    like($res->output, qr/^\* have local name resolution: true/m, "proxy is not used since noproxy has \"\*\" ");
     is( $res->return_code, 0, "Should reach $host_tcp_http_ipv6 with or without proxy." );
 
     # Noproxy domain should prevent using proxy for subdomains of that domain
     $res = NPTest->testCmd( "./$plugin -H $host_tcp_http_subdomain --proxy http://$host_tcp_proxy:$port_tcp_proxy --noproxy $host_tcp_http -v" );
-    like($res->output, qr/^\* proxy_resolves_hostname: 0/m, "proxy is not used since subdomain: $host_tcp_http_subdomain  is under a noproxy domain: $host_tcp_http");
+    like($res->output, qr/^\* have local name resolution: true/m, "proxy is not used since subdomain: $host_tcp_http_subdomain  is under a noproxy domain: $host_tcp_http");
     is( $res->return_code, 0, "Should reach $host_tcp_http_subdomain with or without proxy." );
 
     # Noproxy should prevent using IP matches if an IP is found directly
     $res = NPTest->testCmd( "./$plugin -I $host_tcp_http_ipv4 --proxy http://$host_tcp_proxy:$port_tcp_proxy --noproxy $host_tcp_http_ipv4 -v" );
-    like($res->output, qr/^\* proxy_resolves_hostname: 0/m, "proxy is not used since IP address: $host_tcp_http_ipv4 is added into noproxy: $host_tcp_http_ipv4");
+    like($res->output, qr/^\* have local name resolution: true/m, "proxy is not used since IP address: $host_tcp_http_ipv4 is added into noproxy: $host_tcp_http_ipv4");
     is( $res->return_code, 0, "Should reach $host_tcp_http_ipv4 with or without proxy." );
 
     $res = NPTest->testCmd( "./$plugin -I $host_tcp_http_ipv6 --proxy http://$host_tcp_proxy:$port_tcp_proxy --noproxy $host_tcp_http_ipv6 -v" );
-    like($res->output, qr/^\* proxy_resolves_hostname: 0/m, "proxy is not used since IP address: $host_tcp_http_ipv6 is added into noproxy: $host_tcp_http_ipv6");
+    like($res->output, qr/^\* have local name resolution: true/m, "proxy is not used since IP address: $host_tcp_http_ipv6 is added into noproxy: $host_tcp_http_ipv6");
     is( $res->return_code, 0, "Should reach $host_tcp_http_ipv6 with or without proxy." );
 
     # Noproxy should prevent using IP matches if a CIDR region that contains that Ip is used directly.
     $res = NPTest->testCmd( "./$plugin -I $host_tcp_http_ipv4 --proxy http://$host_tcp_proxy:$port_tcp_proxy --noproxy $host_tcp_http_ipv4_cidr_1 -v" );
-    like($res->output, qr/^\* proxy_resolves_hostname: 0/m, "proxy is not used since IP address: $host_tcp_http_ipv4 is inside CIDR range: $host_tcp_http_ipv4_cidr_1");
+    like($res->output, qr/^\* have local name resolution: true/m, "proxy is not used since IP address: $host_tcp_http_ipv4 is inside CIDR range: $host_tcp_http_ipv4_cidr_1");
     is( $res->return_code, 0, "Should reach $host_tcp_http_ipv4 with or without proxy." );
 
     $res = NPTest->testCmd( "./$plugin -I $host_tcp_http_ipv4 --proxy http://$host_tcp_proxy:$port_tcp_proxy --noproxy $host_tcp_http_ipv4_cidr_2 -v" );
-    like($res->output, qr/^\* proxy_resolves_hostname: 0/m, "proxy is not used since IP address: $host_tcp_http_ipv4 is inside CIDR range: $host_tcp_http_ipv4_cidr_2");
+    like($res->output, qr/^\* have local name resolution: true/m, "proxy is not used since IP address: $host_tcp_http_ipv4 is inside CIDR range: $host_tcp_http_ipv4_cidr_2");
     is( $res->return_code, 0, "Should reach $host_tcp_http_ipv4 with or without proxy." );
 
     $res = NPTest->testCmd( "./$plugin -I $host_tcp_http_ipv6 --proxy http://$host_tcp_proxy:$port_tcp_proxy --noproxy $host_tcp_http_ipv6_cidr_1 -v " );
-    like($res->output, qr/^\* proxy_resolves_hostname: 0/m, "proxy is not used since IP address: $host_tcp_http_ipv6 is inside CIDR range: $host_tcp_http_ipv6_cidr_1");
+    like($res->output, qr/^\* have local name resolution: true/m, "proxy is not used since IP address: $host_tcp_http_ipv6 is inside CIDR range: $host_tcp_http_ipv6_cidr_1");
     is( $res->return_code, 0, "Should reach $host_tcp_http_ipv6 with or without proxy." );
 
     $res = NPTest->testCmd( "./$plugin -I $host_tcp_http_ipv6 --proxy http://$host_tcp_proxy:$port_tcp_proxy --noproxy $host_tcp_http_ipv6_cidr_2 -v" );
-    like($res->output, qr/^\* proxy_resolves_hostname: 0/m, "proxy is not used since IP address: $host_tcp_http_ipv6 is inside CIDR range: $host_tcp_http_ipv6_cidr_2");
+    like($res->output, qr/^\* have local name resolution: true/m, "proxy is not used since IP address: $host_tcp_http_ipv6 is inside CIDR range: $host_tcp_http_ipv6_cidr_2");
     is( $res->return_code, 0, "Should reach $host_tcp_http_ipv6 with or without proxy." );
 
     # Noproxy should discern over different types of proxy schemes
     $res = NPTest->testCmd( "./$plugin -H $host_tcp_http --proxy http://$host_tcp_proxy:$port_tcp_proxy -v" );
-    like($res->output, qr/^\* proxy_resolves_hostname: 1/m, "proxy is used for resolving hostname, and is using scheme http ");
+    like($res->output, qr/^\* have local name resolution: false/m, "proxy is used for resolving hostname, and is using scheme http ");
     is( $res->return_code, 0, "Using proxy http:$host_tcp_proxy:$port_tcp_proxy to connect to $host_tcp_http works" );
 
     $res = NPTest->testCmd( "./$plugin -H $host_tcp_http --proxy https://$host_tcp_proxy:$port_tcp_proxy -v" );
-    like($res->output, qr/^\* proxy_resolves_hostname: 1/m, "proxy is used for resolving hostname, and is using scheme https");
+    like($res->output, qr/^\* have local name resolution: false/m, "proxy is used for resolving hostname, and is using scheme https");
     # Squid is not configured for https
     # is( $res->return_code, 0, "Using proxy https:$host_tcp_proxy:$port_tcp_proxy to connect to $host_tcp_http works" );
 
     $res = NPTest->testCmd( "./$plugin -H $host_tcp_http --proxy socks4://$host_tcp_proxy:$port_tcp_proxy -v" );
-    like($res->output, qr/^\* proxy_resolves_hostname: 0/m, "proxy is not used for resolving hostname, and is using scheme socks4");
+    like($res->output, qr/^\* have local name resolution: true/m, "proxy is not used for resolving hostname, and is using scheme socks4");
     # Squid is not configured for socks4
     # is( $res->return_code, 0, "Using proxy socks4:$host_tcp_proxy:$port_tcp_proxy to connect to $host_tcp_http works" );
 
     $res = NPTest->testCmd( "./$plugin -H $host_tcp_http --proxy socks4a://$host_tcp_proxy:$port_tcp_proxy -v" );
-    like($res->output, qr/^\* proxy_resolves_hostname: 1/m, "proxy is used for resolving hostname, and is using scheme socks4a");
+    like($res->output, qr/^\* have local name resolution: false/m, "proxy is used for resolving hostname, and is using scheme socks4a");
     # Squid is not configured for socks4a
     # is( $res->return_code, 0, "Using proxy socks4a:$host_tcp_proxy:$port_tcp_proxy to connect to $host_tcp_http works" );
 
     $res = NPTest->testCmd( "./$plugin -H $host_tcp_http --proxy socks5://$host_tcp_proxy:$port_tcp_proxy -v" );
-    like($res->output, qr/^\* proxy_resolves_hostname: 0/m, "proxy is not used for resolving hostname, and is using scheme socks5");
+    like($res->output, qr/^\* have local name resolution: true/m, "proxy is not used for resolving hostname, and is using scheme socks5");
     # Squid is not configured for socks5
     # is( $res->return_code, 0, "Using proxy socks5:$host_tcp_proxy:$port_tcp_proxy to connect to $host_tcp_http works" );
 
     $res = NPTest->testCmd( "./$plugin -H $host_tcp_http --proxy socks5h://$host_tcp_proxy:$port_tcp_proxy -v" );
-    like($res->output, qr/^\* proxy_resolves_hostname: 1/m, "proxy is used for resolving hostname, and is using scheme socks5h");
+    like($res->output, qr/^\* have local name resolution: false/m, "proxy is used for resolving hostname, and is using scheme socks5h");
     # Squid is not configured for socks5h
     # is( $res->return_code, 0, "Using proxy socks5h:$host_tcp_proxy:$port_tcp_proxy to connect to $host_tcp_http works" );
 }
diff --git a/plugins/tests/check_curl.t b/plugins/tests/check_curl.t
index e027b6f4..d0a866cb 100755
--- a/plugins/tests/check_curl.t
+++ b/plugins/tests/check_curl.t
@@ -833,12 +833,12 @@ sub run_common_tests {
 		$cmd = "$command -u /statuscode/200 --proxy http://proxy.example.com:8080 --noproxy '*' -v";
 		$result = NPTest->testCmd( $cmd );
 		is( $result->return_code, 0, $cmd);
-		like( $result->output, '/.*proxy_resolves_hostname: 0.*/', "Proxy will not be used due to '*' in noproxy: ".$result->output );
+		like( $result->output, '/.*have local name resolution: true.*/', "Proxy will not be used due to '*' in noproxy: ".$result->output );
 
 		$cmd = "$command -u /statuscode/200 --proxy http://proxy.example.com:8080 --noproxy '127.0.0.1' -v";
 		$result = NPTest->testCmd( $cmd );
 		is( $result->return_code, 0, $cmd);
-		like( $result->output, '/.*proxy_resolves_hostname: 0.*/', "Proxy will not be used due to '127.0.0.1' in noproxy: ".$result->output );
+		like( $result->output, '/.*have local name resolution: true.*/', "Proxy will not be used due to '127.0.0.1' in noproxy: ".$result->output );
 	}
 
 }

From 3a6f9292f147de29b21dafa4cf9b7efce3e4cbfd Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Lorenz=20K=C3=A4stle?=
 <12514511+RincewindsHat@users.noreply.github.com>
Date: Wed, 8 Apr 2026 18:06:29 +0200
Subject: [PATCH 5/6] Rename USE_OPENSSL to MOPL_USE_OPENSSL (#2253)

net-snmp uses the same pre processor name "USE_OPENSSL" as we do.
To avoid the conflict, this commit renames it on our side to
"MOPL_USE_OPENSSL".
"MOPL" (better "MoPl"?) stands for Monitoring Plugins.
---
 configure.ac                              |  2 +-
 lib/utils_base.h                          |  2 +-
 plugins/check_curl.c                      | 26 ++++++++--------
 plugins/check_curl.d/check_curl_helpers.c | 16 +++++-----
 plugins/check_smtp.c                      |  6 ++--
 plugins/check_tcp.c                       |  4 +--
 plugins/sslutils.c                        | 38 +++++++++++------------
 7 files changed, 47 insertions(+), 47 deletions(-)

diff --git a/configure.ac b/configure.ac
index ae7eb30b..e4351ad7 100644
--- a/configure.ac
+++ b/configure.ac
@@ -578,7 +578,7 @@ if test "$FOUNDOPENSSL" = "yes" || test "$FOUNDGNUTLS" = "yes"; then
 	AC_SUBST(SSLLIBS)
 	AC_DEFINE(HAVE_SSL,1,[Define if SSL libraries are found])
 	if test "$FOUNDOPENSSL" = "yes"; then
-		AC_DEFINE(USE_OPENSSL,1,[Define if using OpenSSL libraries])
+		AC_DEFINE(MOPL_USE_OPENSSL,1,[Define if using OpenSSL libraries])
 		with_openssl="yes"
 		with_gnutls="no"
 	else
diff --git a/lib/utils_base.h b/lib/utils_base.h
index 27884bf0..1da96f78 100644
--- a/lib/utils_base.h
+++ b/lib/utils_base.h
@@ -9,7 +9,7 @@
 #include "./thresholds.h"
 #include "states.h"
 
-#ifndef USE_OPENSSL
+#ifndef MOPL_USE_OPENSSL
 #	include "sha256.h"
 #endif
 
diff --git a/plugins/check_curl.c b/plugins/check_curl.c
index b168cbcd..fe7e61d6 100644
--- a/plugins/check_curl.c
+++ b/plugins/check_curl.c
@@ -62,7 +62,7 @@ const char *email = "devel@monitoring-plugins.org";
 #include <arpa/inet.h>
 #include <netinet/in.h>
 
-#if defined(HAVE_SSL) && defined(USE_OPENSSL)
+#if defined(HAVE_SSL) && defined(MOPL_USE_OPENSSL)
 #	include <openssl/opensslv.h>
 #endif
 
@@ -81,9 +81,9 @@ extern char errbuf[MAX_INPUT_BUFFER];
 extern bool is_openssl_callback;
 extern bool add_sslctx_verify_fun;
 
-#if defined(HAVE_SSL) && defined(USE_OPENSSL)
+#if defined(HAVE_SSL) && defined(MOPL_USE_OPENSSL)
 static X509 *cert = NULL;
-#endif /* defined(HAVE_SSL) && defined(USE_OPENSSL) */
+#endif /* defined(HAVE_SSL) && defined(MOPL_USE_OPENSSL) */
 
 typedef struct {
 	int errorcode;
@@ -114,10 +114,10 @@ static void print_curl_version(void);
 // check_curl_evaluation_wrapper check_curl_evaluate(check_curl_config config,
 // 												  mp_check overall[static 1]) {}
 
-#if defined(HAVE_SSL) && defined(USE_OPENSSL)
+#if defined(HAVE_SSL) && defined(MOPL_USE_OPENSSL)
 mp_state_enum np_net_ssl_check_certificate(X509 *certificate, int days_till_exp_warn,
 										   int days_till_exp_crit);
-#endif /* defined(HAVE_SSL) && defined(USE_OPENSSL) */
+#endif /* defined(HAVE_SSL) && defined(MOPL_USE_OPENSSL) */
 
 int main(int argc, char **argv) {
 #ifdef __OpenBSD__
@@ -167,7 +167,7 @@ int main(int argc, char **argv) {
 }
 
 #ifdef HAVE_SSL
-#	ifdef USE_OPENSSL
+#	ifdef MOPL_USE_OPENSSL
 int verify_callback(int preverify_ok, X509_STORE_CTX *x509_ctx) {
 	(void)preverify_ok;
 	/* TODO: we get all certificates of the chain, so which ones
@@ -190,11 +190,11 @@ int verify_callback(int preverify_ok, X509_STORE_CTX *x509_ctx) {
 	}
 	return 1;
 }
-#	endif /* USE_OPENSSL */
+#	endif /* MOPL_USE_OPENSSL */
 #endif     /* HAVE_SSL */
 
 #ifdef HAVE_SSL
-#	ifdef USE_OPENSSL
+#	ifdef MOPL_USE_OPENSSL
 CURLcode sslctxfun(CURL *curl, SSL_CTX *sslctx, void *parm) {
 	(void)curl; // ignore unused parameter
 	(void)parm; // ignore unused parameter
@@ -211,7 +211,7 @@ CURLcode sslctxfun(CURL *curl, SSL_CTX *sslctx, void *parm) {
 
 	return CURLE_OK;
 }
-#	endif /* USE_OPENSSL */
+#	endif /* MOPL_USE_OPENSSL */
 #endif     /* HAVE_SSL */
 
 mp_subcheck check_http(const check_curl_config config, check_curl_working_state workingState,
@@ -1867,7 +1867,7 @@ void print_usage(void) {
 void print_curl_version(void) { printf("%s\n", curl_version()); }
 
 #ifdef LIBCURL_FEATURE_SSL
-#	ifndef USE_OPENSSL
+#	ifndef MOPL_USE_OPENSSL
 time_t parse_cert_date(const char *s) {
 	if (!s) {
 		return -1;
@@ -1884,11 +1884,11 @@ time_t parse_cert_date(const char *s) {
 
 	return date;
 }
-#	endif /* USE_OPENSSL */
+#	endif /* MOPL_USE_OPENSSL */
 #endif     /* LIBCURL_FEATURE_SSL */
 
 #ifdef LIBCURL_FEATURE_SSL
-#	ifndef USE_OPENSSL
+#	ifndef MOPL_USE_OPENSSL
 /* TODO: this needs cleanup in the sslutils.c, maybe we the #else case to
  * OpenSSL could be this function
  */
@@ -2025,5 +2025,5 @@ int net_noopenssl_check_certificate(cert_ptr_union *cert_ptr, int days_till_exp_
 	}
 	return status;
 }
-#	endif /* USE_OPENSSL */
+#	endif /* MOPL_USE_OPENSSL */
 #endif     /* LIBCURL_FEATURE_SSL */
diff --git a/plugins/check_curl.d/check_curl_helpers.c b/plugins/check_curl.d/check_curl_helpers.c
index f23dbdb7..80d6f4f6 100644
--- a/plugins/check_curl.d/check_curl_helpers.c
+++ b/plugins/check_curl.d/check_curl_helpers.c
@@ -439,11 +439,11 @@ check_curl_configure_curl(const check_curl_static_curl_config config,
 		case CURLHELP_SSL_LIBRARY_LIBRESSL:
 			/* set callback to extract certificate with OpenSSL context function (works with
 			 * OpenSSL-style libraries only!) */
-#		ifdef USE_OPENSSL
+#		ifdef MOPL_USE_OPENSSL
 			/* libcurl and monitoring plugins built with OpenSSL, good */
 			add_sslctx_verify_fun = true;
 			is_openssl_callback = true;
-#		endif /* USE_OPENSSL */
+#		endif /* MOPL_USE_OPENSSL */
 			/* libcurl is built with OpenSSL, monitoring plugins, so falling
 			 * back to manually extracting certificate information */
 			handle_curl_option_return_code(
@@ -1312,16 +1312,16 @@ mp_subcheck check_curl_certificate_checks(CURL *curl, X509 *cert, int warn_days_
 
 #ifdef LIBCURL_FEATURE_SSL
 	if (is_openssl_callback) {
-#	ifdef USE_OPENSSL
+#	ifdef MOPL_USE_OPENSSL
 		/* check certificate with OpenSSL functions, curl has been built against OpenSSL
 		 * and we actually have OpenSSL in the monitoring tools
 		 */
 		return mp_net_ssl_check_certificate(cert, warn_days_till_exp, crit_days_till_exp);
-#	else  /* USE_OPENSSL */
+#	else  /* MOPL_USE_OPENSSL */
 		xasprintf(&result.output, "HTTP CRITICAL - Cannot retrieve certificates - OpenSSL "
 								  "callback used and not linked against OpenSSL\n");
 		mp_set_subcheck_state(result, STATE_CRITICAL);
-#	endif /* USE_OPENSSL */
+#	endif /* MOPL_USE_OPENSSL */
 	} else {
 		struct curl_slist *slist;
 
@@ -1329,7 +1329,7 @@ mp_subcheck check_curl_certificate_checks(CURL *curl, X509 *cert, int warn_days_
 		cert_ptr.to_info = NULL;
 		CURLcode res = curl_easy_getinfo(curl, CURLINFO_CERTINFO, &cert_ptr.to_certinfo);
 		if (!res && cert_ptr.to_info) {
-#	ifdef USE_OPENSSL
+#	ifdef MOPL_USE_OPENSSL
 			/* We have no OpenSSL in libcurl, but we can use OpenSSL for X509 cert
 			 * parsing We only check the first certificate and assume it's the one of
 			 * the server
@@ -1375,13 +1375,13 @@ mp_subcheck check_curl_certificate_checks(CURL *curl, X509 *cert, int warn_days_
 
 			BIO_free(cert_BIO);
 			return mp_net_ssl_check_certificate(cert, warn_days_till_exp, crit_days_till_exp);
-#	else  /* USE_OPENSSL */
+#	else  /* MOPL_USE_OPENSSL */
 			/* We assume we don't have OpenSSL and np_net_ssl_check_certificate at our
 			 * disposal, so we use the libcurl CURLINFO data
 			 */
 			return net_noopenssl_check_certificate(&cert_ptr, days_till_exp_warn,
 												   days_till_exp_crit);
-#	endif /* USE_OPENSSL */
+#	endif /* MOPL_USE_OPENSSL */
 		} else {
 			xasprintf(&sc_cert_result.output,
 					  _("Cannot retrieve certificates - cURL returned %d - %s"), res,
diff --git a/plugins/check_smtp.c b/plugins/check_smtp.c
index 24883fd8..19e2a58f 100644
--- a/plugins/check_smtp.c
+++ b/plugins/check_smtp.c
@@ -350,7 +350,7 @@ int main(int argc, char **argv) {
 		}
 	}
 
-#	ifdef USE_OPENSSL
+#	ifdef MOPL_USE_OPENSSL
 	if (ssl_established) {
 		net_ssl_check_cert_result cert_check_result =
 			np_net_ssl_check_cert2(config.days_till_exp_warn, config.days_till_exp_crit);
@@ -389,7 +389,7 @@ int main(int argc, char **argv) {
 
 		mp_add_subcheck_to_check(&overall, sc_cert_check);
 	}
-#	endif /* USE_OPENSSL */
+#	endif /* MOPL_USE_OPENSSL */
 
 #endif
 
@@ -764,7 +764,7 @@ check_smtp_config_wrapper process_arguments(int argc, char **argv) {
 			break;
 		case 'D': {
 			/* Check SSL cert validity */
-#ifdef USE_OPENSSL
+#ifdef MOPL_USE_OPENSSL
 			char *temp;
 			if ((temp = strchr(optarg, ',')) != NULL) {
 				*temp = '\0';
diff --git a/plugins/check_tcp.c b/plugins/check_tcp.c
index 49a8c4c1..cd8e04b0 100644
--- a/plugins/check_tcp.c
+++ b/plugins/check_tcp.c
@@ -683,7 +683,7 @@ static check_tcp_config_wrapper process_arguments(int argc, char **argv, check_t
 			break;
 		case 'D': /* Check SSL cert validity - days 'til certificate expiration */
 #ifdef HAVE_SSL
-#	ifdef USE_OPENSSL /* XXX */
+#	ifdef MOPL_USE_OPENSSL /* XXX */
 		{
 			char *temp;
 			if ((temp = strchr(optarg, ',')) != NULL) {
@@ -708,7 +708,7 @@ static check_tcp_config_wrapper process_arguments(int argc, char **argv, check_t
 			config.check_cert = true;
 			config.use_tls = true;
 		} break;
-#	endif /* USE_OPENSSL */
+#	endif /* MOPL_USE_OPENSSL */
 #endif
 			/* fallthrough if we don't have ssl */
 		case 'S':
diff --git a/plugins/sslutils.c b/plugins/sslutils.c
index c58a35ab..c4ab6a05 100644
--- a/plugins/sslutils.c
+++ b/plugins/sslutils.c
@@ -127,7 +127,7 @@ int np_net_ssl_init_with_hostname_version_and_cert(int sd, char *host_name, int
 	}
 
 	if (cert && privkey) {
-#	ifdef USE_OPENSSL
+#	ifdef MOPL_USE_OPENSSL
 		if (!SSL_CTX_use_certificate_chain_file(ctx, cert)) {
 #	elif USE_GNUTLS
 		if (!SSL_CTX_use_certificate_file(ctx, cert, SSL_FILETYPE_PEM)) {
@@ -138,7 +138,7 @@ int np_net_ssl_init_with_hostname_version_and_cert(int sd, char *host_name, int
 			return STATE_CRITICAL;
 		}
 		SSL_CTX_use_PrivateKey_file(ctx, privkey, SSL_FILETYPE_PEM);
-#	ifdef USE_OPENSSL
+#	ifdef MOPL_USE_OPENSSL
 		if (!SSL_CTX_check_private_key(ctx)) {
 			printf("%s\n", _("CRITICAL - Private key does not seem to match certificate!\n"));
 			return STATE_CRITICAL;
@@ -161,9 +161,9 @@ int np_net_ssl_init_with_hostname_version_and_cert(int sd, char *host_name, int
 			return OK;
 		} else {
 			printf("%s\n", _("CRITICAL - Cannot make SSL connection."));
-#	ifdef USE_OPENSSL /* XXX look into ERR_error_string */
+#	ifdef MOPL_USE_OPENSSL /* XXX look into ERR_error_string */
 			ERR_print_errors_fp(stdout);
-#	endif /* USE_OPENSSL */
+#	endif /* MOPL_USE_OPENSSL */
 		}
 	} else {
 		printf("%s\n", _("CRITICAL - Cannot initiate SSL handshake."));
@@ -192,7 +192,7 @@ int np_net_ssl_read(void *buf, int num) { return SSL_read(s, buf, num); }
 
 mp_state_enum np_net_ssl_check_certificate(X509 *certificate, int days_till_exp_warn,
 										   int days_till_exp_crit) {
-#	ifdef USE_OPENSSL
+#	ifdef MOPL_USE_OPENSSL
 	if (!certificate) {
 		printf("%s\n", _("CRITICAL - No server certificate present to inspect."));
 		return STATE_CRITICAL;
@@ -306,14 +306,14 @@ mp_state_enum np_net_ssl_check_certificate(X509 *certificate, int days_till_exp_
 	}
 	X509_free(certificate);
 	return status;
-#	else  /* ifndef USE_OPENSSL */
+#	else  /* ifndef MOPL_USE_OPENSSL */
 	printf("%s\n", _("WARNING - Plugin does not support checking certificates."));
 	return STATE_WARNING;
-#	endif /* USE_OPENSSL */
+#	endif /* MOPL_USE_OPENSSL */
 }
 
 retrieve_expiration_time_result np_net_ssl_get_cert_expiration(X509 *certificate) {
-#	ifdef USE_OPENSSL
+#	ifdef MOPL_USE_OPENSSL
 	retrieve_expiration_time_result result = {
 		.errors = ALL_OK,
 		.remaining_seconds = 0,
@@ -404,14 +404,14 @@ retrieve_expiration_time_result np_net_ssl_get_cert_expiration(X509 *certificate
 	X509_free(certificate);
 
 	return result;
-#	else  /* ifndef USE_OPENSSL */
+#	else  /* ifndef MOPL_USE_OPENSSL */
 	printf("%s\n", _("WARNING - Plugin does not support checking certificates."));
 	return STATE_WARNING;
-#	endif /* USE_OPENSSL */
+#	endif /* MOPL_USE_OPENSSL */
 }
 
 net_ssl_check_cert_result np_net_ssl_check_cert2(int days_till_exp_warn, int days_till_exp_crit) {
-#	ifdef USE_OPENSSL
+#	ifdef MOPL_USE_OPENSSL
 	X509 *certificate = NULL;
 	certificate = SSL_get_peer_certificate(s);
 
@@ -438,27 +438,27 @@ net_ssl_check_cert_result np_net_ssl_check_cert2(int days_till_exp_warn, int day
 
 	return result;
 
-#	else  /* ifndef USE_OPENSSL */
+#	else  /* ifndef MOPL_USE_OPENSSL */
 	printf("%s\n", _("WARNING - Plugin does not support checking certificates."));
 	return STATE_WARNING;
-#	endif /* USE_OPENSSL */
+#	endif /* MOPL_USE_OPENSSL */
 }
 
 mp_state_enum np_net_ssl_check_cert(int days_till_exp_warn, int days_till_exp_crit) {
-#	ifdef USE_OPENSSL
+#	ifdef MOPL_USE_OPENSSL
 	X509 *certificate = NULL;
 	certificate = SSL_get_peer_certificate(s);
 	return (np_net_ssl_check_certificate(certificate, days_till_exp_warn, days_till_exp_crit));
-#	else  /* ifndef USE_OPENSSL */
+#	else  /* ifndef MOPL_USE_OPENSSL */
 	printf("%s\n", _("WARNING - Plugin does not support checking certificates."));
 	return STATE_WARNING;
-#	endif /* USE_OPENSSL */
+#	endif /* MOPL_USE_OPENSSL */
 }
 
 mp_subcheck mp_net_ssl_check_certificate(X509 *certificate, int days_till_exp_warn,
 										 int days_till_exp_crit) {
 	mp_subcheck sc_cert = mp_subcheck_init();
-#	ifdef USE_OPENSSL
+#	ifdef MOPL_USE_OPENSSL
 	if (!certificate) {
 		xasprintf(&sc_cert.output, _("No server certificate present to inspect"));
 		sc_cert = mp_set_subcheck_state(sc_cert, STATE_CRITICAL);
@@ -581,10 +581,10 @@ mp_subcheck mp_net_ssl_check_certificate(X509 *certificate, int days_till_exp_wa
 	}
 	X509_free(certificate);
 	return sc_cert;
-#	else  /* ifndef USE_OPENSSL */
+#	else  /* ifndef MOPL_USE_OPENSSL */
 	xasprintf(&sc_cert.output, _("Plugin does not support checking certificates"));
 	sc_cert = mp_set_subcheck_state(sc_cert, STATE_WARNING);
 	return sc_cert;
-#	endif /* USE_OPENSSL */
+#	endif /* MOPL_USE_OPENSSL */
 }
 #endif /* HAVE_SSL */

From 1db493092ca6a68ff690251cc428037b54019a73 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Lorenz=20K=C3=A4stle?=
 <12514511+RincewindsHat@users.noreply.github.com>
Date: Wed, 8 Apr 2026 18:26:03 +0200
Subject: [PATCH 6/6] added CHECK_EOF to work around warnings about EOF and -1
 being the same (#2254)

Co-authored-by: Andreas Baumann <mail@andreasbaumann.cc>
---
 plugins/check_cluster.c   | 2 +-
 plugins/check_curl.c      | 2 +-
 plugins/check_dig.c       | 2 +-
 plugins/check_disk.c      | 2 +-
 plugins/check_fping.c     | 2 +-
 plugins/check_game.c      | 2 +-
 plugins/check_hpjd.c      | 2 +-
 plugins/check_ide_smart.c | 2 +-
 plugins/check_ldap.c      | 2 +-
 plugins/check_load.c      | 2 +-
 plugins/check_mysql.c     | 2 +-
 plugins/check_nagios.c    | 2 +-
 plugins/check_ping.c      | 2 +-
 plugins/check_procs.c     | 2 +-
 plugins/check_radius.c    | 2 +-
 plugins/check_snmp.c      | 4 ++--
 plugins/check_tcp.c       | 2 +-
 plugins/check_time.c      | 2 +-
 plugins/common.h          | 7 +++++++
 19 files changed, 26 insertions(+), 19 deletions(-)

diff --git a/plugins/check_cluster.c b/plugins/check_cluster.c
index 1cbdcd60..92c3827a 100644
--- a/plugins/check_cluster.c
+++ b/plugins/check_cluster.c
@@ -175,7 +175,7 @@ check_cluster_config_wrapper process_arguments(int argc, char **argv) {
 	while (true) {
 		int option_index = getopt_long(argc, argv, "hHsvVw:c:d:l:", longopts, &option);
 
-		if (option_index == -1 || option_index == EOF || option_index == 1) {
+		if (CHECK_EOF(option_index) || option_index == 1) {
 			break;
 		}
 
diff --git a/plugins/check_curl.c b/plugins/check_curl.c
index fe7e61d6..67d89129 100644
--- a/plugins/check_curl.c
+++ b/plugins/check_curl.c
@@ -980,7 +980,7 @@ check_curl_config_wrapper process_arguments(int argc, char **argv) {
 		int option_index = getopt_long(
 			argc, argv, "Vvh46t:c:w:A:k:H:P:j:T:I:a:x:b:d:e:p:s:R:r:u:f:C:J:K:DnlLS::m:M:NEB",
 			longopts, &option);
-		if (option_index == -1 || option_index == EOF || option_index == 1) {
+		if (CHECK_EOF(option_index) || option_index == 1) {
 			break;
 		}
 
diff --git a/plugins/check_dig.c b/plugins/check_dig.c
index 9ea19e6a..9ec8028a 100644
--- a/plugins/check_dig.c
+++ b/plugins/check_dig.c
@@ -284,7 +284,7 @@ check_dig_config_wrapper process_arguments(int argc, char **argv) {
 		int option_index =
 			getopt_long(argc, argv, "hVvt:l:H:w:c:T:p:a:A:E:X:46", longopts, &option);
 
-		if (option_index == -1 || option_index == EOF) {
+		if (CHECK_EOF(option_index)) {
 			break;
 		}
 
diff --git a/plugins/check_disk.c b/plugins/check_disk.c
index 73fe815e..e773e56c 100644
--- a/plugins/check_disk.c
+++ b/plugins/check_disk.c
@@ -448,7 +448,7 @@ check_disk_config_wrapper process_arguments(int argc, char **argv) {
 		int option_index = getopt_long(
 			argc, argv, "+?VqhvefCt:c:w:K:W:u:p:x:X:N:mklLPg:R:r:i:I:MEAn", longopts, &option);
 
-		if (option_index == -1 || option_index == EOF) {
+		if (CHECK_EOF(option_index)) {
 			break;
 		}
 
diff --git a/plugins/check_fping.c b/plugins/check_fping.c
index 6160c2cb..86ef64a4 100644
--- a/plugins/check_fping.c
+++ b/plugins/check_fping.c
@@ -361,7 +361,7 @@ check_fping_config_wrapper process_arguments(int argc, char **argv) {
 		int option_index =
 			getopt_long(argc, argv, "+hVvaH:S:c:w:b:n:T:i:I:M:R:46", longopts, &option);
 
-		if (option_index == -1 || option_index == EOF || option_index == 1) {
+		if (CHECK_EOF(option_index) || option_index == 1) {
 			break;
 		}
 
diff --git a/plugins/check_game.c b/plugins/check_game.c
index 974a7253..48ec6883 100644
--- a/plugins/check_game.c
+++ b/plugins/check_game.c
@@ -186,7 +186,7 @@ check_game_config_wrapper process_arguments(int argc, char **argv) {
 	while (true) {
 		int option_index = getopt_long(argc, argv, "hVvt:H:P:G:g:p:m:", long_opts, &opt_index);
 
-		if (option_index == -1 || option_index == EOF) {
+		if (CHECK_EOF(option_index)) {
 			break;
 		}
 
diff --git a/plugins/check_hpjd.c b/plugins/check_hpjd.c
index 9907abc5..883f1df0 100644
--- a/plugins/check_hpjd.c
+++ b/plugins/check_hpjd.c
@@ -299,7 +299,7 @@ check_hpjd_config_wrapper process_arguments(int argc, char **argv) {
 	while (true) {
 		int option_index = getopt_long(argc, argv, "+hVH:C:p:D", longopts, &option);
 
-		if (option_index == -1 || option_index == EOF || option_index == 1) {
+		if (CHECK_EOF(option_index) || option_index == 1) {
 			break;
 		}
 
diff --git a/plugins/check_ide_smart.c b/plugins/check_ide_smart.c
index c1325cf9..43731039 100644
--- a/plugins/check_ide_smart.c
+++ b/plugins/check_ide_smart.c
@@ -169,7 +169,7 @@ static check_ide_smart_config_wrapper process_arguments(int argc, char **argv) {
 		int longindex = 0;
 		int option_index = getopt_long(argc, argv, "+d:iq10nhVv", longopts, &longindex);
 
-		if (option_index == -1 || option_index == EOF || option_index == 1) {
+		if (CHECK_EOF(option_index) || option_index == 1) {
 			break;
 		}
 
diff --git a/plugins/check_ldap.c b/plugins/check_ldap.c
index 7f8282b4..0e8c5804 100644
--- a/plugins/check_ldap.c
+++ b/plugins/check_ldap.c
@@ -362,7 +362,7 @@ check_ldap_config_wrapper process_arguments(int argc, char **argv) {
 		int option_index =
 			getopt_long(argc, argv, "hvV234TS6t:c:w:H:b:p:a:D:P:C:W:", longopts, &option);
 
-		if (option_index == -1 || option_index == EOF) {
+		if (CHECK_EOF(option_index)) {
 			break;
 		}
 
diff --git a/plugins/check_load.c b/plugins/check_load.c
index 644cd604..60fa646f 100644
--- a/plugins/check_load.c
+++ b/plugins/check_load.c
@@ -295,7 +295,7 @@ static check_load_config_wrapper process_arguments(int argc, char **argv) {
 		int option = 0;
 		int option_index = getopt_long(argc, argv, "Vhrc:w:n:", longopts, &option);
 
-		if (option_index == -1 || option_index == EOF) {
+		if (CHECK_EOF(option_index)) {
 			break;
 		}
 
diff --git a/plugins/check_mysql.c b/plugins/check_mysql.c
index 15005bf5..b70e0e22 100644
--- a/plugins/check_mysql.c
+++ b/plugins/check_mysql.c
@@ -504,7 +504,7 @@ check_mysql_config_wrapper process_arguments(int argc, char **argv) {
 		int option_index =
 			getopt_long(argc, argv, "hlvVnSP:p:u:d:H:s:c:w:a:k:C:D:L:f:g:", longopts, &option);
 
-		if (option_index == -1 || option_index == EOF) {
+		if (CHECK_EOF(option_index)) {
 			break;
 		}
 
diff --git a/plugins/check_nagios.c b/plugins/check_nagios.c
index a46dc1ed..e2f230c9 100644
--- a/plugins/check_nagios.c
+++ b/plugins/check_nagios.c
@@ -227,7 +227,7 @@ check_nagios_config_wrapper process_arguments(int argc, char **argv) {
 	while (true) {
 		int option_index = getopt_long(argc, argv, "+hVvF:C:e:t:", longopts, &option);
 
-		if (option_index == -1 || option_index == EOF || option_index == 1) {
+		if (CHECK_EOF(option_index) || option_index == 1) {
 			break;
 		}
 
diff --git a/plugins/check_ping.c b/plugins/check_ping.c
index e1ee0f5c..0c9cb19d 100644
--- a/plugins/check_ping.c
+++ b/plugins/check_ping.c
@@ -221,7 +221,7 @@ check_ping_config_wrapper process_arguments(int argc, char **argv) {
 	while (true) {
 		int option_index = getopt_long(argc, argv, "VvhnL46t:c:w:H:p:", longopts, &option);
 
-		if (option_index == -1 || option_index == EOF) {
+		if (CHECK_EOF(option_index)) {
 			break;
 		}
 
diff --git a/plugins/check_procs.c b/plugins/check_procs.c
index 50837cb4..174dcd97 100644
--- a/plugins/check_procs.c
+++ b/plugins/check_procs.c
@@ -432,7 +432,7 @@ check_procs_config_wrapper process_arguments(int argc, char **argv) {
 		int option_index =
 			getopt_long(argc, argv, "Vvhkt:c:w:p:s:u:C:a:z:r:m:P:TX:", longopts, &option);
 
-		if (option_index == -1 || option_index == EOF) {
+		if (CHECK_EOF(option_index)) {
 			break;
 		}
 
diff --git a/plugins/check_radius.c b/plugins/check_radius.c
index f20af660..03153926 100644
--- a/plugins/check_radius.c
+++ b/plugins/check_radius.c
@@ -334,7 +334,7 @@ check_radius_config_wrapper process_arguments(int argc, char **argv) {
 		int option = 0;
 		int option_index = getopt_long(argc, argv, "+hVvH:P:F:u:p:n:N:t:r:e:", longopts, &option);
 
-		if (option_index == -1 || option_index == EOF || option_index == 1) {
+		if (CHECK_EOF(option_index) || option_index == 1) {
 			break;
 		}
 
diff --git a/plugins/check_snmp.c b/plugins/check_snmp.c
index 1746fd79..0f62ce8b 100644
--- a/plugins/check_snmp.c
+++ b/plugins/check_snmp.c
@@ -447,7 +447,7 @@ static process_arguments_wrapper process_arguments(int argc, char **argv) {
 			argc, argv,
 			"nhvVO46t:c:w:H:C:o:e:E:d:D:s:t:R:r:l:u:p:m:P:N:L:U:a:x:A:X:M:f:z:", longopts, &option);
 
-		if (option_char == -1 || option_char == EOF) {
+		if (CHECK_EOF(option_char)) {
 			break;
 		}
 
@@ -517,7 +517,7 @@ static process_arguments_wrapper process_arguments(int argc, char **argv) {
 			argc, argv,
 			"nhvVO46t:c:w:H:C:o:e:E:d:D:s:t:R:r:l:u:p:m:P:N:L:U:a:x:A:X:M:f:z:", longopts, &option);
 
-		if (option_char == -1 || option_char == EOF) {
+		if (CHECK_EOF(option_char)) {
 			break;
 		}
 
diff --git a/plugins/check_tcp.c b/plugins/check_tcp.c
index cd8e04b0..924322e4 100644
--- a/plugins/check_tcp.c
+++ b/plugins/check_tcp.c
@@ -562,7 +562,7 @@ static check_tcp_config_wrapper process_arguments(int argc, char **argv, check_t
 		int option_index =
 			getopt_long(argc, argv, "+hVv46EAH:s:e:q:m:c:w:t:p:C:W:d:Sr:jD:M:", longopts, &option);
 
-		if (option_index == -1 || option_index == EOF || option_index == 1) {
+		if (CHECK_EOF(option_index) || option_index == 1) {
 			break;
 		}
 
diff --git a/plugins/check_time.c b/plugins/check_time.c
index 99708ad3..aec995d4 100644
--- a/plugins/check_time.c
+++ b/plugins/check_time.c
@@ -213,7 +213,7 @@ check_time_config_wrapper process_arguments(int argc, char **argv) {
 		int option = 0;
 		option_char = getopt_long(argc, argv, "hVH:w:c:W:C:p:t:u", longopts, &option);
 
-		if (option_char == -1 || option_char == EOF) {
+		if (CHECK_EOF(option_char)) {
 			break;
 		}
 
diff --git a/plugins/common.h b/plugins/common.h
index b3053486..9d1434a3 100644
--- a/plugins/common.h
+++ b/plugins/common.h
@@ -205,4 +205,11 @@ enum {
 #	define __attribute__(x) /* do nothing */
 #endif
 
+/* for checking the result of getopt_long */
+#if EOF == -1
+#define CHECK_EOF(c) ((c) == EOF)
+#else
+#define CHECK_EOF(c) ((c) == -1 || (c) == EOF)
+#endif
+
 #endif /* _COMMON_H_ */