Check and create v6 migration directory before trying to move/write files there. This involves config migrations but also Teleporter importing

Signed-off-by: DL6ER <dl6er@dl6er.de>

src/api/teleporter.c

@@ -29,6 +29,8 @@
 #include <libgen.h>
 // restart_ftl()
 #include "signals.h"
+// create_migration_target_v6()
+#include "config/config.h"
 
 #define MAXFILESIZE (50u*1024*1024)
 
@@ -264,6 +266,9 @@ static int api_teleporter_POST(struct ftl_conn *api)
 		                       NULL);
 	}
 
+	// Ensure v6 migration directory exists
+	create_migration_target_v6();
+
 	// Check if we received something that claims to be a ZIP archive
 	// - filename should end in ".zip"
 	// - the data itself

src/config/config.c

@@ -1624,13 +1624,19 @@ bool readFTLconf(struct config *conf, const bool rewrite)
 	if(!rewrite)
 		return false;
 
+	// Check if MIGRATION_TARGET_V6 exists and is a directory
+	// Ideally, this directory should be created by the installer but users
+	// may have deleted it manually and it is necessary for restoring
+	// Teleporter files
+	create_migration_target_v6();
+
 	// If no previous config file could be read, we are likely either running
 	// for the first time or we are upgrading from a version prior to v6.0
 	// In this case, we try to read the legacy config files
 	const char *path = "";
 	if((path = readFTLlegacy(conf)) != NULL)
 	{
-		const char *target = "/etc/pihole/migration_backup_v6/pihole-FTL.conf";
+		const char *target = MIGRATION_TARGET_V6"/pihole-FTL.conf";
 		log_info("Moving %s to %s", path, target);
 		if(rename(path, target) != 0)
 			log_warn("Unable to move %s to %s: %s", path, target, strerror(errno));
@@ -1903,3 +1909,32 @@ static bool port_in_use(const in_port_t port)
 	close(sock);
 	return false;
 }
+
+/**
+ * @brief Create a migration target directory for version 6.
+ *
+ * This function creates a directory for migration target version 6. If the directory
+ * already exists, it does nothing. The function also changes the ownership of the
+ * directory to the user running the FTL program.
+ *
+ * @return true if the directory creation and ownership change were successful, false otherwise.
+ */
+bool create_migration_target_v6(void)
+{
+	if(mkdir(MIGRATION_TARGET_V6, 0755) != 0 && errno != EEXIST)
+	{
+		log_err("Unable to create directory %s: %s", MIGRATION_TARGET_V6, strerror(errno));
+		return false;
+	}
+	else
+	{
+		// Change ownership of the directory to the user running FTL
+		if(chown(MIGRATION_TARGET_V6, getuid(), getgid()) != 0)
+		{
+			log_err("Unable to change ownership of %s: %s", MIGRATION_TARGET_V6, strerror(errno));
+			return false;
+		}
+	}
+
+	return true;
+}

src/config/config.h

@@ -39,6 +39,9 @@
 // Location of the legacy (pre-v6.0) config file
 #define GLOBALCONFFILE_LEGACY "/etc/pihole/pihole-FTL.conf"
 
+// Migration target for the legacy (pre-v6.0) config file
+#define MIGRATION_TARGET_V6 "/etc/pihole/migration_backup_v6"
+
 union conf_value {
 	bool b;                                     // boolean value
 	int i;                                      // integer value
@@ -363,6 +366,7 @@ bool check_paths_equal(char **paths1, char **paths2, unsigned int max_level) __a
 const char *get_conf_type_str(const enum conf_type type) __attribute__ ((const));
 void replace_config(struct config *newconf);
 void reread_config(void);
+bool create_migration_target_v6(void);
 
 // Defined in toml_reader.c
 bool readDebugSettings(void);

src/config/dnsmasq_config.h

@@ -24,12 +24,12 @@ bool write_custom_list(void);
 
 #define DNSMASQ_PH_CONFIG "/etc/pihole/dnsmasq.conf"
 #define DNSMASQ_TEMP_CONF "/etc/pihole/dnsmasq.conf.temp"
-#define DNSMASQ_STATIC_LEASES "/etc/pihole/migration_backup_v6/04-pihole-static-dhcp.conf"
-#define DNSMASQ_CNAMES "/etc/pihole/migration_backup_v6/05-pihole-custom-cname.conf"
+#define DNSMASQ_STATIC_LEASES MIGRATION_TARGET_V6"/04-pihole-static-dhcp.conf"
+#define DNSMASQ_CNAMES MIGRATION_TARGET_V6"/05-pihole-custom-cname.conf"
 #define DNSMASQ_HOSTSDIR "/etc/pihole/hosts"
 #define DNSMASQ_CUSTOM_LIST DNSMASQ_HOSTSDIR"/custom.list"
 #define DNSMASQ_CUSTOM_LIST_LEGACY "/etc/pihole/custom.list"
-#define DNSMASQ_CUSTOM_LIST_LEGACY_TARGET "/etc/pihole/migration_backup_v6/custom.list"
+#define DNSMASQ_CUSTOM_LIST_LEGACY_TARGET MIGRATION_TARGET_V6"/custom.list"
 #define DHCPLEASESFILE "/etc/pihole/dhcp.leases"
 
 #endif //DNSMASQ_CONFIG_H

src/config/setupVars.c

@@ -589,7 +589,7 @@ void importsetupVarsConf(void)
 	get_conf_string_from_setupVars("WEB_PORTS", &config.webserver.port);
 
 	// Move the setupVars.conf file to the migration directory
-	const char *setupVars_target = "/etc/pihole/migration_backup_v6/setupVars.conf";
+	const char *setupVars_target = MIGRATION_TARGET_V6"/setupVars.conf";
 	if(rename(config.files.setupVars.v.s, setupVars_target) != 0)
 		log_warn("Could not move %s to %s", config.files.setupVars.v.s, setupVars_target);
 	else