diff --git a/src/auth.c b/src/auth.c
index 85663072..d56326b3 100644
--- a/src/auth.c
+++ b/src/auth.c
@@ -41,6 +41,7 @@
 
 #include "config.h"
 #include "auth.h"
+#include "common.h"
 #include "dhcp.h"
 #include "dhcp6.h"
 #include "dhcpcd.h"
@@ -437,16 +438,17 @@ auth_get_rdm_monotonic(uint64_t *rdm)
 	int flocked;
 #endif
 
-	fp = fopen(RDM_MONOFILE, "r+");
+	ensure_dir(dhcpcd_rdm_monofile, 0750);
+	fp = fopen(dhcpcd_rdm_monofile, "r+");
 	if (fp == NULL) {
 		if (errno != ENOENT)
 			return -1;
-		fp = fopen(RDM_MONOFILE, "w");
+		fp = fopen(dhcpcd_rdm_monofile, "w");
 		if (fp == NULL)
 			return -1;
-		if (chmod(RDM_MONOFILE, 0400) == -1) {
+		if (chmod(dhcpcd_rdm_monofile, 0400) == -1) {
 			(void)fclose(fp);
-			unlink(RDM_MONOFILE);
+			unlink(dhcpcd_rdm_monofile);
 			return -1;
 		}
 #ifdef LOCK_EX
diff --git a/src/common.c b/src/common.c
index d938ef00..0c363f28 100644
--- a/src/common.c
+++ b/src/common.c
@@ -146,12 +146,96 @@ readfile(const char *file, void **data, size_t *len)
 	return bytes;
 }
 
+/* Return a copy of s with every '%' doubled so it is safe to use as a
+ * literal within a printf-style format string. Returns NULL on failure. */
+char *
+escape_percent(const char *s)
+{
+	const char *p;
+	char *r, *d;
+	size_t extra = 0;
+
+	if (s == NULL)
+		s = "";
+	for (p = s; *p != '\0'; p++)
+		if (*p == '%')
+			extra++;
+	r = malloc(strlen(s) + extra + 1);
+	if (r == NULL)
+		return NULL;
+	for (p = s, d = r; *p != '\0'; p++) {
+		if (*p == '%')
+			*d++ = '%';
+		*d++ = *p;
+	}
+	*d = '\0';
+	return r;
+}
+
+/* Create a directory and any missing parents, like mkdir -p. */
+int
+mkdirs(const char *dir, mode_t mode)
+{
+	char *d, *p;
+	int r = 0;
+
+	if (dir == NULL || dir[0] == '\0') {
+		errno = EINVAL;
+		return -1;
+	}
+	d = strdup(dir);
+	if (d == NULL)
+		return -1;
+	for (p = d + 1; *p != '\0'; p++) {
+		if (*p != '/')
+			continue;
+		*p = '\0';
+		if (mkdir(d, mode) == -1 && errno != EEXIST)
+			r = -1;
+		*p = '/';
+	}
+	if (mkdir(d, mode) == -1 && errno != EEXIST)
+		r = -1;
+	free(d);
+	return r;
+}
+
+/* Ensure the directory part of a file path exists. */
+int
+ensure_dir(const char *file, mode_t mode)
+{
+	char *d, *p;
+	int r;
+
+	if (file == NULL) {
+		errno = EINVAL;
+		return -1;
+	}
+	d = strdup(file);
+	if (d == NULL)
+		return -1;
+	p = strrchr(d, '/');
+	if (p == NULL) {
+		free(d);
+		return 0;
+	}
+	if (p == d)
+		*(p + 1) = '\0';
+	else
+		*p = '\0';
+	r = mkdirs(d, mode);
+	free(d);
+	return r;
+}
+
 ssize_t
 writefile(const char *file, mode_t mode, const void *data, size_t len)
 {
 	int fd;
 	ssize_t bytes;
 
+	if (ensure_dir(file, 0750) == -1)
+		return -1;
 	fd = open(file, O_WRONLY | O_CREAT | O_TRUNC, mode);
 	if (fd == -1)
 		return -1;
diff --git a/src/common.h b/src/common.h
index 577afc4d..29df45e2 100644
--- a/src/common.h
+++ b/src/common.h
@@ -169,6 +169,9 @@ const char *hwaddr_ntoa(const void *, size_t, char *, size_t);
 size_t hwaddr_aton(uint8_t *, const char *);
 ssize_t readfile(const char *, void **, size_t *);
 ssize_t writefile(const char *, mode_t, const void *, size_t);
+char *escape_percent(const char *);
+int mkdirs(const char *, mode_t);
+int ensure_dir(const char *, mode_t);
 int filemtime(const char *, time_t *);
 char *get_line(char **__restrict, size_t *__restrict);
 int is_root_local(void);
diff --git a/src/control.c b/src/control.c
index 9164b7ab..6f883538 100644
--- a/src/control.c
+++ b/src/control.c
@@ -491,7 +491,7 @@ make_path(char *path, size_t len, const char *ifname, sa_family_t family)
 		per = "";
 		break;
 	}
-	return snprintf(path, len, CONTROLSOCKET, ifname ? ifname : "",
+	return snprintf(path, len, dhcpcd_controlsock, ifname ? ifname : "",
 	    ifname ? per : "", "", ifname ? "." : "");
 }
 
@@ -521,6 +521,8 @@ control_start1(struct dhcpcd_ctx *ctx, const char *ifname, sa_family_t family)
 	if (fd == -1)
 		return -1;
 
+	ensure_dir(sa.sun_path, 0755);
+
 	len = (socklen_t)SUN_LEN(&sa);
 	if (GID_SET(ctx->control_group) && GID_SET(ctx->read_group)) {
 		if (ctx->control_group == ctx->read_group) {
diff --git a/src/defs.h b/src/defs.h
index fe8c51c4..4c4a7ad8 100644
--- a/src/defs.h
+++ b/src/defs.h
@@ -66,6 +66,32 @@
 #define RDM_MONOFILE DBDIR "/rdm_monotonic"
 #endif
 
+/*
+ * Runtime configurable paths.
+ * These default to the compiled in values but can be overridden at runtime
+ * with the corresponding command line options (--instance, --dbdir, --rundir,
+ * --devdir). The individual file paths are derived from these and rebuilt
+ * whenever a base directory is changed (see dhcpcd_paths_update()).
+ */
+extern const char *dhcpcd_dbdir;
+extern const char *dhcpcd_rundir;
+extern const char *dhcpcd_devdir;
+extern const char *dhcpcd_instance;
+extern const char *dhcpcd_duidfile;
+extern const char *dhcpcd_secretfile;
+extern const char *dhcpcd_rdm_monofile;
+extern const char *dhcpcd_leasefile;
+extern const char *dhcpcd_leasefile6;
+extern const char *dhcpcd_pidfile;
+extern const char *dhcpcd_controlsock;
+
+void dhcpcd_paths_init(void);
+void dhcpcd_paths_update(void);
+void dhcpcd_paths_set_dbdir(const char *);
+void dhcpcd_paths_set_rundir(const char *);
+void dhcpcd_paths_set_devdir(const char *);
+void dhcpcd_paths_set_instance(const char *);
+
 #ifndef NO_SIGNALS
 #define USE_SIGNALS
 #endif
diff --git a/src/dev.c b/src/dev.c
index bada148c..45d9ce16 100644
--- a/src/dev.c
+++ b/src/dev.c
@@ -99,7 +99,7 @@ dev_start2(struct dhcpcd_ctx *ctx, const struct dev_dhcpcd *dev_dhcpcd,
 	void (*fptr)(struct dev *, const struct dev_dhcpcd *);
 	int r;
 
-	snprintf(file, sizeof(file), DEVDIR "/%s", name);
+	snprintf(file, sizeof(file), "%s/%s", dhcpcd_devdir, name);
 	h = dlopen(file, RTLD_LAZY);
 	if (h == NULL) {
 		logerrx("dlopen: %s", dlerror());
@@ -143,9 +143,9 @@ dev_start1(struct dhcpcd_ctx *ctx, const struct dev_dhcpcd *dev_dhcpcd)
 	if (ctx->dev_load)
 		return dev_start2(ctx, dev_dhcpcd, ctx->dev_load);
 
-	dp = opendir(DEVDIR);
+	dp = opendir(dhcpcd_devdir);
 	if (dp == NULL) {
-		logdebug("dev: %s", DEVDIR);
+		logdebug("dev: %s", dhcpcd_devdir);
 		return -1;
 	}
 
diff --git a/src/dhcp-common.c b/src/dhcp-common.c
index e87094de..5b10a67c 100644
--- a/src/dhcp-common.c
+++ b/src/dhcp-common.c
@@ -1041,7 +1041,8 @@ dhcp_set_leasefile(char *leasefile, size_t len, int family,
 	} else
 		ssid[0] = '\0';
 	return snprintf(leasefile, len,
-	    family == AF_INET ? LEASEFILE : LEASEFILE6, ifname, ssid);
+	    family == AF_INET ? dhcpcd_leasefile : dhcpcd_leasefile6, ifname,
+	    ssid);
 }
 
 void
diff --git a/src/dhcpcd.8.in b/src/dhcpcd.8.in
index 26d37772..9707ef28 100644
--- a/src/dhcpcd.8.in
+++ b/src/dhcpcd.8.in
@@ -61,6 +61,10 @@
 .Op Fl Z , Fl Fl denyinterfaces Ar pattern
 .Op Fl z , Fl Fl allowinterfaces Ar pattern
 .Op Fl Fl inactive
+.Op Fl Fl instance Ar instance
+.Op Fl Fl dbdir Ar dir
+.Op Fl Fl rundir Ar dir
+.Op Fl Fl devdir Ar dir
 .Op Fl Fl configure
 .Op Fl Fl noconfigure
 .Op interface
@@ -271,9 +275,9 @@ Use a DHCP Unique Identifier.
 If persistent storage is available then a DUID-LLT
 (link local address + time) is generated,
 otherwise DUID-LL is generated (link local address).
-The DUID type can be hinted as an optional parameter if the file
-.Pa @DBDIR@/duid
-does not exist.
+ The DUID type can be hinted as an optional parameter if the default DUID file
+ .Pa @DBDIR@/duid
+ does not exist.
 If not
 .Va ll ,
 .Va lt
@@ -284,9 +288,9 @@ then
 will be converted from 00:11:22:33 format.
 This, plus the IAID will be used as the
 .Fl I , Fl Fl clientid .
-The DUID generated will be held in
-.Pa @DBDIR@/duid
-and should not be copied to other hosts.
+ The DUID generated will be held in the default DUID file
+ .Pa @DBDIR@/duid
+ and should not be copied to other hosts.
 This file also takes precedence over the above rules except for setting a value.
 .It Fl d , Fl Fl debug
 Echo debug messages to the stderr and syslog.
@@ -778,6 +782,51 @@ addition of
 Don't load any
 .Pa /dev
 management modules.
+.It Fl Fl instance Ar instance
+Prefix the state and runtime files that
+.Nm
+writes, namely the DUID, secret, lease, RDM, PID and control socket files,
+with the
+.Ar instance
+name inside the state and runtime directories.
+.Ar instance
+must be a single path component and must not contain a
+.Sq / .
+For example,
+.Fl Fl instance=foo
+will cause the DUID file to be written to
+.Pa @DBDIR@/ Ns Pa foo Ns .duid
+and the PID file to
+.Pa @RUNDIR@/ Ns Pa foo Ns .pid .
+The base directories remain unchanged.
+.It Fl Fl dbdir Ar dir
+Specify the base directory where
+.Nm
+stores its lease and state database.
+This overrides the compiled in default
+.Pa @DBDIR@ .
+Without
+.Fl Fl instance
+the DUID, secret, lease and RDM files are created directly here, otherwise
+they are created here under the file name prefixed with the instance name.
+.It Fl Fl rundir Ar dir
+Specify the base directory where
+.Nm
+stores its runtime files, such as the PID file and control socket.
+This overrides the compiled in default
+.Pa @RUNDIR@ .
+Without
+.Fl Fl instance
+the PID file and control socket are created directly here, otherwise they
+are created here under the file name prefixed with the instance name.
+.It Fl Fl devdir Ar dir
+Specify the directory from which
+.Nm
+loads
+.Pa /dev
+management modules.
+This overrides the compiled in default
+.Pa @LIBDIR@/dhcpcd/dev .
 .El
 .Sh 3RDPARTY LINK MANAGEMENT
 Some interfaces require configuration by 3rd parties, such as PPP or VPN.
@@ -818,6 +867,18 @@ sends to match.
 If using a DUID in place of the ClientID, edit
 .Pa @DBDIR@/duid
 accordingly.
+.Pp
+The file paths shown in this manual, such as
+.Pa @DBDIR@/duid ,
+are the compiled in defaults.
+The effective path used by
+.Nm
+can be changed with the
+.Fl Fl dbdir ,
+.Fl Fl rundir
+and
+.Fl Fl instance
+options described above.
 .Sh FILES
 .Bl -ohang
 .It Pa @SYSCONFDIR@/dhcpcd.conf
diff --git a/src/dhcpcd.c b/src/dhcpcd.c
index bf277bbc..500df63b 100644
--- a/src/dhcpcd.c
+++ b/src/dhcpcd.c
@@ -101,6 +101,179 @@ const size_t dhcpcd_signals_ignore_len = __arraycount(dhcpcd_signals_ignore);
 
 const char *dhcpcd_default_script = SCRIPT;
 
+/*
+ * Runtime configurable paths.
+ * The base directories (dbdir, rundir, devdir) default to the compiled in
+ * values but may be overridden on the command line. When dhcpcd_instance is
+ * set, all files dhcpcd writes (lease, DUID, secret, RDM, PID and control
+ * socket files) are placed under the instance directory and named after the
+ * state or runtime directory. The file paths are derived from the base
+ * directories by dhcpcd_paths_update().
+ */
+const char *dhcpcd_dbdir;
+const char *dhcpcd_rundir;
+const char *dhcpcd_devdir;
+const char *dhcpcd_instance;
+const char *dhcpcd_duidfile;
+const char *dhcpcd_secretfile;
+const char *dhcpcd_rdm_monofile;
+const char *dhcpcd_leasefile;
+const char *dhcpcd_leasefile6;
+const char *dhcpcd_pidfile;
+const char *dhcpcd_controlsock;
+
+/* Initialise the runtime paths to the compiled in defaults and derive the
+ * file paths. Must be called before any other dhcpcd_paths_* function. */
+void
+dhcpcd_paths_init(void)
+{
+	dhcpcd_dbdir = strdup(DBDIR);
+	dhcpcd_rundir = strdup(RUNDIR);
+	dhcpcd_devdir = strdup(DEVDIR);
+	if (dhcpcd_dbdir == NULL || dhcpcd_rundir == NULL ||
+	    dhcpcd_devdir == NULL) {
+		logerrx("out of memory");
+		exit(EXIT_FAILURE);
+	}
+	dhcpcd_paths_update();
+}
+
+/* Replace *var with a copy of value, freeing the previous string. */
+static void
+path_set_str(const char **var, const char *value)
+{
+	free(UNCONST(*var));
+	*var = strdup(value);
+	if (*var == NULL) {
+		logerrx("out of memory");
+		exit(EXIT_FAILURE);
+	}
+}
+
+/* Set the state/lease database directory and rebuild the derived paths. */
+void
+dhcpcd_paths_set_dbdir(const char *dir)
+{
+	path_set_str(&dhcpcd_dbdir, dir);
+	dhcpcd_paths_update();
+}
+
+/* Set the runtime directory and rebuild the derived paths. */
+void
+dhcpcd_paths_set_rundir(const char *dir)
+{
+	path_set_str(&dhcpcd_rundir, dir);
+	dhcpcd_paths_update();
+}
+
+/* Set the directory from which /dev management modules are loaded. */
+void
+dhcpcd_paths_set_devdir(const char *dir)
+{
+	path_set_str(&dhcpcd_devdir, dir);
+}
+
+/* Set the instance directory and rebuild the derived paths. The instance
+ * must be a single path component without '/'. */
+void
+dhcpcd_paths_set_instance(const char *instance)
+{
+	if (strchr(instance, '/') != NULL) {
+		logerrx("--instance must not contain a '/': %s", instance);
+		exit(EXIT_FAILURE);
+	}
+	path_set_str(&dhcpcd_instance, instance);
+	dhcpcd_paths_update();
+}
+
+/* Rebuild all derived file paths from the current base directories and
+ * instance. The lease, lease6, PID and control socket paths are returned
+ * as printf-style format strings. */
+void
+dhcpcd_paths_update(void)
+{
+	char *duidfile = NULL, *secretfile = NULL, *rdm_monofile = NULL;
+	char *leasefile = NULL, *leasefile6 = NULL, *pidfile = NULL;
+	char *controlsock = NULL;
+	char *einstance, *edbdir, *erundir;
+
+	free(UNCONST(dhcpcd_duidfile));
+	free(UNCONST(dhcpcd_secretfile));
+	free(UNCONST(dhcpcd_rdm_monofile));
+	free(UNCONST(dhcpcd_leasefile));
+	free(UNCONST(dhcpcd_leasefile6));
+	free(UNCONST(dhcpcd_pidfile));
+	free(UNCONST(dhcpcd_controlsock));
+
+	/* lease, lease6, pid and controlsock are later used as printf-style
+	 * format strings, so escape '%' in the configured directories. */
+	einstance = escape_percent(dhcpcd_instance);
+	edbdir = escape_percent(dhcpcd_dbdir);
+	erundir = escape_percent(dhcpcd_rundir);
+	if (einstance == NULL || edbdir == NULL || erundir == NULL)
+		goto oom;
+
+	if (dhcpcd_instance != NULL && dhcpcd_instance[0] != '\0') {
+		/*
+		 * The instance name is used as a file name base inside the
+		 * state and runtime directories, e.g. <dbdir>/<instance>.duid.
+		 */
+		if (asprintf(&duidfile, "%s/%s.duid", dhcpcd_dbdir,
+			dhcpcd_instance) == -1 ||
+		    asprintf(&secretfile, "%s/%s.secret", dhcpcd_dbdir,
+			dhcpcd_instance) == -1 ||
+		    asprintf(&rdm_monofile, "%s/%s.rdm_monotonic", dhcpcd_dbdir,
+			dhcpcd_instance) == -1 ||
+		    asprintf(&leasefile, "%s/%s.%%s%%s.lease", edbdir,
+			einstance) == -1 ||
+		    asprintf(&leasefile6, "%s/%s.%%s%%s.lease6", edbdir,
+			einstance) == -1 ||
+		    asprintf(&pidfile, "%s/%s.%%s%%s%%spid", erundir,
+			einstance) == -1 ||
+		    asprintf(&controlsock, "%s/%s.%%s%%s%%s%%ssock", erundir,
+			einstance) == -1)
+			goto oom;
+	} else {
+		if (asprintf(&duidfile, "%s/duid", dhcpcd_dbdir) == -1 ||
+		    asprintf(&secretfile, "%s/secret", dhcpcd_dbdir) == -1 ||
+		    asprintf(&rdm_monofile, "%s/rdm_monotonic", dhcpcd_dbdir) ==
+			-1 ||
+		    asprintf(&leasefile, "%s/%%s%%s.lease", edbdir) == -1 ||
+		    asprintf(&leasefile6, "%s/%%s%%s.lease6", edbdir) == -1 ||
+		    asprintf(&pidfile, "%s/%%s%%s%%spid", erundir) == -1 ||
+		    asprintf(&controlsock, "%s/%%s%%s%%s%%ssock", erundir) ==
+			-1)
+			goto oom;
+	}
+
+	free(einstance);
+	free(edbdir);
+	free(erundir);
+
+	dhcpcd_duidfile = duidfile;
+	dhcpcd_secretfile = secretfile;
+	dhcpcd_rdm_monofile = rdm_monofile;
+	dhcpcd_leasefile = leasefile;
+	dhcpcd_leasefile6 = leasefile6;
+	dhcpcd_pidfile = pidfile;
+	dhcpcd_controlsock = controlsock;
+	return;
+
+oom:
+	free(duidfile);
+	free(secretfile);
+	free(rdm_monofile);
+	free(leasefile);
+	free(leasefile6);
+	free(pidfile);
+	free(controlsock);
+	free(einstance);
+	free(edbdir);
+	free(erundir);
+	logerrx("out of memory");
+	exit(EXIT_FAILURE);
+}
+
 static void
 usage(void)
 {
@@ -119,7 +292,8 @@ usage(void)
 	    "\t\t[-v, --vendor code, value] [-W, --whitelist address[/cidr]] [-w]\n"
 	    "\t\t[--waitip [4 | 6]] [-y, --reboot seconds]\n"
 	    "\t\t[-X, --blacklist address[/cidr]] [-Z, --denyinterfaces pattern]\n"
-	    "\t\t[-z, --allowinterfaces pattern] [--inactive] [interface] [...]\n"
+	    "\t\t[-z, --allowinterfaces pattern] [--inactive] [--instance instance]\n"
+	    "\t\t[--dbdir dir] [--rundir dir] [--devdir dir] [interface] [...]\n"
 	    "       " PACKAGE "\t-n, --rebind [interface]\n"
 	    "       " PACKAGE "\t-k, --release [interface]\n"
 	    "       " PACKAGE "\t-U, --dumplease interface\n"
@@ -2138,6 +2312,7 @@ main(int argc, char **argv, char **envp)
 
 	memset(&ctx, 0, sizeof(ctx));
 	closefrom(STDERR_FILENO + 1);
+	dhcpcd_paths_init();
 
 	ifo = NULL;
 	ctx.cffile = CONFIG;
@@ -2247,6 +2422,18 @@ main(int argc, char **argv, char **envp)
 		case 'V':
 			i = 2;
 			break;
+		case O_DBDIR:
+			dhcpcd_paths_set_dbdir(optarg);
+			break;
+		case O_RUNDIR:
+			dhcpcd_paths_set_rundir(optarg);
+			break;
+		case O_DEVDIR:
+			dhcpcd_paths_set_devdir(optarg);
+			break;
+		case O_INSTANCE:
+			dhcpcd_paths_set_instance(optarg);
+			break;
 		case '?':
 			if (ctx.options & DHCPCD_PRINT_PIDFILE)
 				continue;
@@ -2354,13 +2541,14 @@ main(int argc, char **argv, char **envp)
 			default:
 				per = "";
 			}
-			if (asprintf(&ctx.pidfile, PIDFILE, ifname, per, ".") ==
-			    -1) {
+			if (asprintf(&ctx.pidfile, dhcpcd_pidfile, ifname, per,
+				".") == -1) {
 				logerr("%s: asprintf", __func__);
 				goto exit_failure;
 			}
 		} else {
-			if (asprintf(&ctx.pidfile, PIDFILE, "", "", "") == -1) {
+			if (asprintf(&ctx.pidfile, dhcpcd_pidfile, "", "",
+				"") == -1) {
 				logerr("%s: asprintf", __func__);
 				goto exit_failure;
 			}
@@ -2539,10 +2727,7 @@ main(int argc, char **argv, char **envp)
 
 	if (!(ctx.options & DHCPCD_TEST)) {
 		/* Ensure we have the needed directories */
-		if (mkdir(DBDIR, 0750) == -1 && errno != EEXIST)
-			logerr("%s: mkdir: %s", __func__, DBDIR);
-		if (mkdir(RUNDIR, 0755) == -1 && errno != EEXIST)
-			logerr("%s: mkdir: %s", __func__, RUNDIR);
+		ensure_dir(ctx.pidfile, 0755);
 		if ((pid = pidfile_lock(ctx.pidfile)) != 0) {
 			if (pid == -1)
 				logerr("%s: pidfile_lock: %s", __func__,
@@ -2648,6 +2833,7 @@ main(int argc, char **argv, char **envp)
 
 start_manager:
 	ctx.options |= DHCPCD_STARTED;
+	ensure_dir(ctx.pidfile, 0755);
 	if ((pid = pidfile_lock(ctx.pidfile)) != 0) {
 		logerr("%s: pidfile_lock %d", __func__, (int)pid);
 #ifdef PRIVSEP
diff --git a/src/duid.c b/src/duid.c
index d3cba7e6..95b437d5 100644
--- a/src/duid.c
+++ b/src/duid.c
@@ -163,16 +163,16 @@ duid_get(struct dhcpcd_ctx *ctx, const struct interface *ifp)
 
 	/* If we already have a DUID then use it as it's never supposed
 	 * to change once we have one even if the interfaces do */
-	if ((len = dhcp_read_hwaddr_aton(ctx, &data, DUID)) != 0) {
+	if ((len = dhcp_read_hwaddr_aton(ctx, &data, dhcpcd_duidfile)) != 0) {
 		if (len <= DUID_LEN) {
 			ctx->duid = data;
 			return len;
 		}
-		logerrx("DUID too big (max %u): %s", DUID_LEN, DUID);
+		logerrx("DUID too big (max %u): %s", DUID_LEN, dhcpcd_duidfile);
 		/* Keep the buffer, will assign below. */
 	} else {
 		if (errno != ENOENT)
-			logerr("%s", DUID);
+			logerr("%s", dhcpcd_duidfile);
 		if ((data = malloc(DUID_LEN)) == NULL) {
 			logerr(__func__);
 			return 0;
@@ -228,7 +228,7 @@ duid_get(struct dhcpcd_ctx *ctx, const struct interface *ifp)
 		line[slen++] = '\n';
 		line[slen] = '\0';
 	}
-	if (dhcp_writefile(ctx, DUID, 0640, line, slen) == -1) {
+	if (dhcp_writefile(ctx, dhcpcd_duidfile, 0640, line, slen) == -1) {
 		logerr("%s: cannot write duid", __func__);
 		if (ctx->duid_type != DUID_LL)
 			return duid_make(data, ifp, DUID_LL);
diff --git a/src/if-options.c b/src/if-options.c
index 7b445f45..f50a323f 100644
--- a/src/if-options.c
+++ b/src/if-options.c
@@ -180,6 +180,10 @@ const struct option cf_options[] = { { "background", no_argument, NULL, 'b' },
 	{ "backoff_cutoff", required_argument, NULL, O_BACKOFF_CUTOFF },
 	{ "backoff_jitter", required_argument, NULL, O_BACKOFF_JITTER },
 	{ "allow", required_argument, NULL, O_ALLOW },
+	{ "dbdir", required_argument, NULL, O_DBDIR },
+	{ "rundir", required_argument, NULL, O_RUNDIR },
+	{ "devdir", required_argument, NULL, O_DEVDIR },
+	{ "instance", required_argument, NULL, O_INSTANCE },
 	{ NULL, 0, NULL, '\0' } };
 
 static char *
@@ -2647,6 +2651,26 @@ parse_option(struct dhcpcd_ctx *ctx, const char *ifname, struct if_options *ifo,
 			return -1;
 		}
 		break;
+	case O_DBDIR:
+		ARG_REQUIRED;
+		if (!(ctx->options & DHCPCD_STARTED))
+			dhcpcd_paths_set_dbdir(arg);
+		break;
+	case O_RUNDIR:
+		ARG_REQUIRED;
+		if (!(ctx->options & DHCPCD_STARTED))
+			dhcpcd_paths_set_rundir(arg);
+		break;
+	case O_DEVDIR:
+		ARG_REQUIRED;
+		if (!(ctx->options & DHCPCD_STARTED))
+			dhcpcd_paths_set_devdir(arg);
+		break;
+	case O_INSTANCE:
+		ARG_REQUIRED;
+		if (!(ctx->options & DHCPCD_STARTED))
+			dhcpcd_paths_set_instance(arg);
+		break;
 	default:
 		return 0;
 	}
diff --git a/src/if-options.h b/src/if-options.h
index 0158b9ae..6823941b 100644
--- a/src/if-options.h
+++ b/src/if-options.h
@@ -205,6 +205,10 @@
 #define O_BACKOFF_JITTER     O_BASE + 62
 #define O_ALLOW		     O_BASE + 63
 #define O_READGRP	     O_BASE + 64
+#define O_DBDIR		     O_BASE + 65
+#define O_RUNDIR	     O_BASE + 66
+#define O_DEVDIR	     O_BASE + 67
+#define O_INSTANCE	     O_BASE + 68
 
 extern const struct option cf_options[];
 
diff --git a/src/ipv6.c b/src/ipv6.c
index 80ee4ad3..d1dd0f5f 100644
--- a/src/ipv6.c
+++ b/src/ipv6.c
@@ -154,7 +154,8 @@ ipv6_readsecret(struct dhcpcd_ctx *ctx)
 	size_t len;
 	uint32_t r;
 
-	ctx->secret_len = dhcp_read_hwaddr_aton(ctx, &ctx->secret, SECRET);
+	ctx->secret_len = dhcp_read_hwaddr_aton(ctx, &ctx->secret,
+	    dhcpcd_secretfile);
 	if (ctx->secret_len != 0)
 		return (ssize_t)ctx->secret_len;
 
@@ -185,7 +186,7 @@ ipv6_readsecret(struct dhcpcd_ctx *ctx)
 		line[len++] = '\n';
 		line[len] = '\0';
 	}
-	if (dhcp_writefile(ctx, SECRET, S_IRUSR, line, len) == -1) {
+	if (dhcp_writefile(ctx, dhcpcd_secretfile, S_IRUSR, line, len) == -1) {
 		logerr("%s: cannot write secret", __func__);
 		ctx->secret_len = 0;
 		return -1;
diff --git a/src/privsep-root.c b/src/privsep-root.c
index 47170c8e..c4c59d95 100644
--- a/src/privsep-root.c
+++ b/src/privsep-root.c
@@ -264,12 +264,17 @@ static bool
 ps_root_validpath(const struct dhcpcd_ctx *ctx, uint16_t cmd, const char *path,
     size_t len)
 {
+	size_t dbdirlen, rundirlen;
+
 	/* path must be a valid string */
 	if (memchr(path, '\0', len) == NULL) {
 		errno = EINVAL;
 		return false;
 	}
 
+	dbdirlen = strlen(dhcpcd_dbdir);
+	rundirlen = strlen(dhcpcd_rundir);
+
 	/* Avoid a previous directory attack to avoid /proc/../
 	 * dhcpcd should never use a path with double dots. */
 	if (strstr(path, "..") != NULL)
@@ -283,9 +288,11 @@ ps_root_validpath(const struct dhcpcd_ctx *ctx, uint16_t cmd, const char *path,
 		if (strcmp(ctx->cffile, path) == 0)
 			return true;
 	}
-	if (strncmp(DBDIR, path, strlen(DBDIR)) == 0)
+	if (strncmp(dhcpcd_dbdir, path, dbdirlen) == 0 &&
+	    (path[dbdirlen] == '\0' || path[dbdirlen] == '/'))
 		return true;
-	if (strncmp(RUNDIR, path, strlen(RUNDIR)) == 0)
+	if (strncmp(dhcpcd_rundir, path, rundirlen) == 0 &&
+	    (path[rundirlen] == '\0' || path[rundirlen] == '/'))
 		return true;
 
 #ifdef __linux__