Fix #235: support for overriding /etc/finit.conf and /etc/finit.d

This change adds support for a new command line option finit.config=PATH
which can be used to tell Finit to start with /etc/factory.conf instead
of /etc/finit.conf.

For the complete experience a new top-level configuration file directive
`rcsd PATH` has aslo been added.  It in turn can be used by factory.conf
as follows to override /etc/finit.d:

    rcsd /etc/factory.d

Manually verified in myLinux

Signed-off-by: Joachim Wiberg <troglobit@gmail.com>

doc/cmdline.md

@@ -23,6 +23,16 @@ The `bool` setting is one of `on, off, true false, 1, 0`.
 
   > Note: `<boot/...>` conditions cannot be cleared with `initctl`!
 
+* `finit.config=/path/to/alternative/finit.conf`: override the
+  compile-time bootstrap config file, default:
+
+        ./configure --with-config=/etc/finit.conf
+
+   Useful when starting up in various rescue mode, factory, or
+   production test setups.  Use the top-level configuration file
+   directive `rcsd /path/to/finit.d` to override the default
+   rcS.d directory.
+
 * `finit.debug[=bool]`: Enable finit debug.  This is operated
 	independently of the kernel `debug` setting.  New as of Finit v4.
 

doc/config.md

@@ -10,6 +10,7 @@ Configuration
   * [Hostname](#hostname)
   * [Kernel Modules](#kernel-modules)
   * [Networking](#networking)
+  * [Alternate rcS.d/](#alternate-rcs-d-)
   * [Resource Limits](#resource-limits)
   * [Runlevels](#runlevels)
   * [One-shot Commands (sequence)](#one-shot-commands--sequence-)
@@ -40,6 +41,13 @@ Linux distributions -- each package can provide its own "script" file.
 - `/etc/finit.conf`: main configuration file
 - `/etc/finit.d/*.conf`: snippets, usually one service per file
 
+> **Note:** the above .conf file name and rcS.d directory name are the
+> defaults.  They can be changed at compile-time with two `configure`
+> options: `--with-config=FOO` and `--with-rcsd=BAR`.
+>
+> They can also be overridden from the command line `finit.config=BAZ`
+> and the top-level configuration directive `rcsd /path/to/finit.d`.
+
 Not all configuration directives are available in `/etc/finit.d/*.conf`
 and some directives are only available at [bootstrap][], runlevel `S`,
 see the section [Limitations](#limitations) below for details.
@@ -332,6 +340,27 @@ Debian, Ubuntu, Linux Mint, or an embedded BusyBox system.
 > **Note:** only read and executed in runlevel S ([bootstrap][]).
 
 
+### Alternate finit.d/
+
+**Syntax:** `rcsd /path/to/finit.d`
+
+The Finit rcS.d directory is set at compile time with:
+
+    ./configure --with-rcsd=/etc/finit.d
+
+A system with multiple use-cases may be bootstrapped with different
+configurations, starting with the kernel command line option:
+
+    -- finit.config=/etc/factory.conf
+
+This file in turn can use the `rcsd` directive to tell Finit to use
+another set of .conf files, e.g.:
+
+    rcsd /etc/factory.d
+
+> **Note:** this directive is only available from the top-level
+> bootstrap .conf file.
+
 ### Resource Limits
 
 **Syntax:** `rlimit [hard|soft] RESOURCE <LIMIT|unlimited>`

src/conf.c

@@ -90,6 +90,7 @@ fallback:
 }
 
 /*
+ * finit.config = /path/to/etc/alt-finit.conf
  * finit.debug  = [on,off]
  * finit.fstab  = /path/to/etc/fstab.aternative
  * finit.status = [on,off]     (compat finit.show_status)
@@ -103,18 +104,27 @@ static void parse_finit_opts(char *opt)
 	if (arg)
 		*arg++ = 0;
 
+	if (string_compare(opt, "cond")) {
+		cond_boot_parse(arg);
+		return;
+	}
+
+	if (string_compare(opt, "config")) {
+		if (finit_conf)
+			free(finit_conf);
+		finit_conf = strdup(arg);
+		return;
+	}
+
 	if (string_compare(opt, "debug")) {
 		debug = get_bool(arg, 1);
 		return;
 	}
 
 	if (string_compare(opt, "fstab")) {
-		fstab = arg;
+		if (fstab)
-		return;
+			free(fstab);
-	}
+		fstab = strdup(arg);
-
-	if (string_compare(opt, "cond")) {
-		cond_boot_parse(arg);
 		return;
 	}
 
@@ -250,6 +260,11 @@ static void parse_kernel_loglevel(void)
  */
 void conf_parse_cmdline(int argc, char *argv[])
 {
+	/* Set up defaults */
+	fstab      = strdup(FINIT_FSTAB);
+	finit_conf = strdup(FINIT_CONF);
+	finit_rcsd = strdup(FINIT_RCSD);
+
 	for (int i = 1; i < argc; i++)
 		parse_arg(argv[i]);
 
@@ -280,6 +295,28 @@ void conf_reset_env(void)
 	setenv("USER", "root", 1);
 }
 
+/*
+ * Sourced mainly by initctl and other Finit helper tools
+ */
+void conf_saverc(void)
+{
+	FILE *fp;
+
+	fp = fopen(_PATH_VARRUN "finit/.initrc", "w");
+	if (!fp) {
+		err(1, "failed creating .finitrc");
+		return;
+	}
+
+	fprintf(fp, "FINIT_CONF=%s\n", finit_conf);
+	fprintf(fp, "FINIT_RCSD=%s\n", finit_rcsd);
+	fprintf(fp, "FINIT_CGPATH=%s\n", FINIT_CGPATH);
+	fprintf(fp, "INIT_SOCKET=%s\n", INIT_SOCKET);
+	fprintf(fp, "INIT_MAGIC=0x%08x\n", INIT_MAGIC);
+
+	fclose(fp);
+}
+
 /*
  * Sets, and makes a note of, all KEY=VALUE lines in a given .conf line
  * from finit.conf, or other .conf file.  Note, PATH is always reset in
@@ -654,6 +691,12 @@ static int parse_static(char *line, int is_rcsd)
 		return 0;
 	}
 
+	if (BOOTSTRAP && MATCH_CMD(line, "rcsd ", x)) {
+		if (finit_rcsd) free(finit_rcsd);
+		finit_rcsd = strdup(strip_line(x));
+		return 0;
+	}
+
 	if (BOOTSTRAP && MATCH_CMD(line, "runparts ", x)) {
 		if (runparts) free(runparts);
 		runparts = strdup(strip_line(x));
@@ -845,6 +888,7 @@ static int parse_conf(char *file, int is_rcsd)
  */
 int conf_reload(void)
 {
+	char path[strlen(finit_rcsd) + 16];
 	size_t i;
 	glob_t gl;
 
@@ -877,7 +921,7 @@ int conf_reload(void)
 	}
 
 	/* First, read /etc/finit.conf */
-	parse_conf(FINIT_CONF, 0);
+	parse_conf(finit_conf, 0);
 
 	/* Set global limits */
 	for (int i = 0; i < RLIMIT_NLIMITS; i++) {
@@ -887,8 +931,10 @@ int conf_reload(void)
 	}
 
 	/* Next, read all *.conf in /etc/finit.d/ */
-	glob(FINIT_RCSD "/*.conf", 0, NULL, &gl);
+	snprintf(path, sizeof(path), "%s/*.conf", finit_rcsd);
-	glob(FINIT_RCSD "/enabled/*.conf", GLOB_APPEND, NULL, &gl);
+	glob(path, 0, NULL, &gl);
+	snprintf(path, sizeof(path), "%s/enabled/*.conf", finit_rcsd);
+	glob(path, GLOB_APPEND, NULL, &gl);
 
 	for (i = 0; i < gl.gl_pathc; i++) {
 		char *path = gl.gl_pathv[i];
@@ -1099,6 +1145,7 @@ static void conf_cb(uev_t *w, void *arg, int events)
  */
 int conf_monitor(void)
 {
+	char path[strlen(finit_rcsd) + 16];
 	int rc = 0;
 
 	/*
@@ -1107,10 +1154,12 @@ int conf_monitor(void)
 	 * have or not have symlinks in place.  We need to monitor for
 	 * changes to either symlink or target.
 	 */
-	rc += iwatch_add(&iw_conf, FINIT_RCSD, IN_ONLYDIR);
+	rc += iwatch_add(&iw_conf, finit_rcsd, IN_ONLYDIR);
-	rc += iwatch_add(&iw_conf, FINIT_RCSD "/available/", IN_ONLYDIR | IN_DONT_FOLLOW);
+	snprintf(path, sizeof(path), "%s/available/", finit_rcsd);
-	rc += iwatch_add(&iw_conf, FINIT_RCSD "/enabled/",   IN_ONLYDIR | IN_DONT_FOLLOW);
+	rc += iwatch_add(&iw_conf, path, IN_ONLYDIR | IN_DONT_FOLLOW);
-	rc += iwatch_add(&iw_conf, FINIT_CONF, 0);
+	snprintf(path, sizeof(path), "%s/enabled/", finit_rcsd);
+	rc += iwatch_add(&iw_conf, path, IN_ONLYDIR | IN_DONT_FOLLOW);
+	rc += iwatch_add(&iw_conf, finit_conf, 0);
 
 	/*
 	 * Systems with /etc/default, /etc/conf.d, or similar, can also
@@ -1151,7 +1200,7 @@ int conf_init(uev_ctx_t *ctx)
 	memcpy(global_rlimit, initial_rlimit, sizeof(global_rlimit));
 
 	/* Read global rlimits and global cgroup setup from /etc/finit.conf */
-	parse_conf(FINIT_CONF, 0);
+	parse_conf(finit_conf, 0);
 
 	/* prepare /etc watcher */
 	fd = iwatch_init(&iw_conf);

src/conf.h

@@ -43,6 +43,7 @@ int  conf_changed         (char *file);
 int  conf_monitor         (void);
 
 void conf_reset_env       (void);
+void conf_saverc          (void);
 void conf_parse_cmdline   (int argc, char *argv[]);
 int  conf_parse_runlevels (char *runlevels);
 void conf_parse_cond      (svc_t *svc, char *cond);

src/finit.c

@@ -69,11 +69,12 @@ int   rescue    = 0;		/* rescue mode from kernel cmdline */
 int   single    = 0;		/* single user mode from kernel cmdline */
 int   bootstrap = 1;		/* set while bootrapping (for TTYs) */
 int   kerndebug = 0;		/* set if /proc/sys/kernel/printk > 7 */
-char *fstab     = FINIT_FSTAB;
+char *finit_conf= NULL;
+char *finit_rcsd= NULL;
+char *fstab     = NULL;
 char *sdown     = NULL;
 char *network   = NULL;
 char *hostname  = NULL;
-char *rcsd      = FINIT_RCSD;
 char *runparts  = NULL;
 char *osheading = NULL;
 
@@ -808,9 +809,11 @@ int main(int argc, char *argv[])
 	cond_set_oneshot(plugin_hook_str(HOOK_ROOTFS_UP));
 
 	/*
-	 * Initialize .conf system and load static /etc/finit.conf.
+	 * Initialize .conf system and load static /etc/finit.conf then
+	 * tell the world what we used.
 	 */
 	conf_init(&loop);
+	conf_saverc();
 
 	/*
 	 * Start built-in watchdogd as soon as possible, if enabled

src/finit.h

@@ -122,7 +122,6 @@ extern char  *fstab;
 extern char  *sdown;
 extern char  *network;
 extern char  *hostname;
-extern char  *rcsd;
 extern char  *runparts;
 extern char  *osheading;
 extern uev_ctx_t *ctx;

src/initctl.c

@@ -56,6 +56,9 @@ struct cmd {
 	int        (*cb_multiarg)(int argc, char **argv);
 };
 
+char *finit_conf = NULL;
+char *finit_rcsd = NULL;
+
 int icreate  = 0;
 int iforce   = 0;
 int ionce    = 0;
@@ -1187,9 +1190,9 @@ static int transform(char *nm)
 
 static int has_conf(char *path, size_t len, char *name)
 {
-	paste(path, len, FINIT_RCSD, name);
+	paste(path, len, finit_rcsd, name);
 	if (!fisdir(path)) {
-		strlcpy(path, FINIT_RCSD, len);
+		strlcpy(path, finit_rcsd, len);
 		return 0;
 	}
 
@@ -1198,7 +1201,7 @@ static int has_conf(char *path, size_t len, char *name)
 
 static int usage(int rc)
 {
-	int has_rcsd = fisdir(FINIT_RCSD);
+	int has_rcsd = fisdir(finit_rcsd);
 	int has_ena;
 	char avail[256];
 	char ena[256];
@@ -1230,16 +1233,16 @@ static int usage(int rc)
 
 	if (has_rcsd)
 		fprintf(stderr,
-			"  ls | list                 List all .conf in " FINIT_RCSD "\n"
+			"  ls | list                 List all .conf in %s\n"
 			"  create   <CONF>           Create   .conf in %s\n"
 			"  delete   <CONF>           Delete   .conf in %s\n"
 			"  show     <CONF>           Show     .conf in %s\n"
 			"  edit     <CONF>           Edit     .conf in %s\n"
 			"  touch    <CONF>           Change   .conf in %s\n",
-			avail, avail, avail, avail, avail);
+			finit_rcsd, avail, avail, avail, avail, avail);
 	else
 		fprintf(stderr,
-			"  show                      Show     %s\n", FINIT_CONF);
+			"  show                      Show     %s\n", finit_conf);
 
 	if (has_ena)
 		fprintf(stderr,
@@ -1249,10 +1252,10 @@ static int usage(int rc)
 			"  disable  <CONF>           Disable  .conf in %s\n", ena);
 	if (has_rcsd)
 		fprintf(stderr,
-			"  reload                    Reload  *.conf in " FINIT_RCSD " (activate changes)\n");
+			"  reload                    Reload  *.conf in %s (activate changes)\n", finit_rcsd);
 	else
 		fprintf(stderr,
-			"  reload                    Reload   " FINIT_CONF " (activate changes)\n");
+			"  reload                    Reload   %s (activate changes)\n", finit_conf);
 
 	fprintf(stderr,
 		"\n"
@@ -1356,6 +1359,69 @@ static int cmd_parse(int argc, char *argv[], struct cmd *command)
 	return command[0].cb(NULL); /* default cmd */
 }
 
+static char *fgetval(char *line, const char *key, char *sep)
+{
+	char *ptr, *str, *copy;
+	size_t len;
+
+	str = copy = strdup(line);
+	if (!copy)
+		return NULL;
+
+	ptr = strsep(&str, sep);
+	if (ptr && strcmp(ptr, key)) {
+	fail:
+		free(copy);
+		return NULL;
+	}
+
+	ptr = strsep(&str, sep);
+	if (!ptr)
+		goto fail;
+
+	len = strlen(ptr) + 1;
+	memmove(copy, ptr, len);
+
+	return realloc(copy, len);
+}
+
+static void cleanup(void)
+{
+	if (finit_conf)
+		free(finit_conf);
+	if (finit_rcsd)
+		free(finit_rcsd);
+}
+
+static void sourcerc(void)
+{
+	char *line;
+	FILE *fp;
+
+	fp = fopen(_PATH_VARRUN "finit/.initrc", "r");
+	if (!fp)
+		goto fallback;
+
+	while ((line = fparseln(fp, NULL, NULL, NULL, 0))) {
+		char *val;
+
+		if ((val = fgetval(line, "FINIT_CONF", "=")))
+			finit_conf = val;
+		if ((val = fgetval(line, "FINIT_RCSD", "=")))
+			finit_rcsd = val;
+
+		free(line);
+	}
+
+fallback:
+	if (!finit_conf)
+		finit_conf = strdup(FINIT_CONF);
+	if (!finit_rcsd)
+		finit_rcsd = strdup(FINIT_RCSD);
+
+	atexit(cleanup);
+}
+
 int main(int argc, char *argv[])
 {
 	struct option long_options[] = {
@@ -1431,6 +1497,7 @@ int main(int argc, char *argv[])
 		return reboot_main(argc, argv);
 
 	/* Enable functionality depending on system capabilities */
+	sourcerc();
 	cgrp = cgroup_avail();
 	utmp = has_utmp();
 

src/initctl.h

@@ -29,6 +29,9 @@
 #include "finit.h"
 #include "util.h"
 
+extern char *finit_conf;
+extern char *finit_rcsd;
+
 extern int icreate;			/* initctl -c */
 extern int iforce;			/* initctl -f */
 extern int ionce;			/* initctl -1 */

src/private.h

@@ -32,6 +32,9 @@
 #define MATCH_CMD(l, c, x) \
 	(!strncasecmp(l, c, strlen(c)) && (x = (l) + strlen(c)))
 
+extern char *finit_conf;
+extern char *finit_rcsd;
+
 extern int service_interval;
 
 int       api_init         (uev_ctx_t *ctx);

src/serv.c

@@ -153,7 +153,7 @@ int serv_list(char *arg)
 	char path[256];
 
 	if (arg && arg[0]) {
-		paste(path, sizeof(path), FINIT_RCSD, arg);
+		paste(path, sizeof(path), finit_rcsd, arg);
 		if (fisdir(path)) {
 			do_list(path);
 			return 0;
@@ -161,19 +161,19 @@ int serv_list(char *arg)
 		/* fall back to list all */
 	}
 
-	paste(path, sizeof(path), FINIT_RCSD, "available");
+	paste(path, sizeof(path), finit_rcsd, "available");
 	if (fisdir(path))
 		do_list(path);
 
-	paste(path, sizeof(path), FINIT_RCSD, "enabled");
+	paste(path, sizeof(path), finit_rcsd, "enabled");
 	if (fisdir(path))
 		do_list(path);
 
-	if (fisdir(FINIT_RCSD))
+	if (fisdir(finit_rcsd))
-		do_list(FINIT_RCSD);
+		do_list(finit_rcsd);
 
-	if (fexist(FINIT_CONF))
+	if (fexist(finit_conf))
-		do_list(FINIT_CONF);
+		do_list(finit_conf);
 
 	return 0;
 }
@@ -197,7 +197,7 @@ static char *conf(char *path, size_t len, char *name, int creat)
 	char corr[40];
 
 	if (!name || !name[0] || !strcmp(name, "finit") || !strcmp(name, "finit.conf")) {
-		strlcpy(path, FINIT_CONF, len);
+		strlcpy(path, finit_conf, len);
 		return path;
 	}
 
@@ -206,21 +206,21 @@ static char *conf(char *path, size_t len, char *name, int creat)
 		name = corr;
 	}
 
-	if (!fisdir(FINIT_RCSD))
+	if (!fisdir(finit_rcsd))
 		return NULL;
 
-	paste(path, len, FINIT_RCSD, "available/");
+	paste(path, len, finit_rcsd, "available/");
 	if (!fisdir(path)) {
 		if (creat && mkdir(path, 0755) && errno != EEXIST)
 			return NULL;
 		else
-			paste(path, len, FINIT_RCSD, name);
+			paste(path, len, finit_rcsd, name);
 	} else
 		strlcat(path, name, len);
 
 	/* fall back to static service unless edit/create */
 	if (!creat && !fexist(path))
-		paste(path, len, FINIT_RCSD, name);
+		paste(path, len, finit_rcsd, name);
 
 	return path;
 }
@@ -241,11 +241,11 @@ int serv_enable(char *arg)
 		arg = corr;
 	}
 
-	if (chdir(FINIT_RCSD))
+	if (chdir(finit_rcsd))
-		ERR(72, "failed cd %s", FINIT_RCSD);
+		ERR(72, "failed cd %s", finit_rcsd);
 
 	if (icreate && mkdir("enabled", 0755) && EEXIST != errno)
-		ERR(73, "failed creating %s/enabled directory", FINIT_RCSD);
+		ERR(73, "failed creating %s/enabled directory", finit_rcsd);
 	ena = !chdir("enabled");   /* System *may* have enabled/ dir. */
 
 	snprintf(path, sizeof(path), "%savailable/%s", ena ? "../" : "", arg);
@@ -273,10 +273,10 @@ int do_disable(char *arg, int check)
 		arg = corr;
 	}
 
-	if (chdir(FINIT_RCSD))
+	if (chdir(finit_rcsd))
-		ERR(72, "failed cd %s", FINIT_RCSD);
+		ERR(72, "failed cd %s", finit_rcsd);
 	if (chdir("enabled"))	   /* System *may* have enabled/ dir. */
-		dbg("Failed changing to %s/enabled/: %s", FINIT_RCSD, strerror(errno));
+		dbg("Failed changing to %s/enabled/: %s", finit_rcsd, strerror(errno));
 
 	if (check && stat(arg, &st))
 		ERRX(6, "%s not (an) enabled (service).", arg);
@@ -309,7 +309,7 @@ int serv_touch(char *arg)
 		if (is_builtin(arg))
 			ERRX(4, "%s is a built-in service.", arg);
 
-		strlcpy(path, FINIT_CONF, sizeof(path));
+		strlcpy(path, finit_conf, sizeof(path));
 		fn = path;
 	}
 
@@ -391,7 +391,7 @@ static int do_edit(char *arg, int creat)
 int serv_edit(char *arg)
 {
 	if (!arg || !arg[0]) {
-		if (!yorn("Do you want to edit %s (y/N)? ", FINIT_CONF))
+		if (!yorn("Do you want to edit %s (y/N)? ", finit_conf))
 			return 0;
 		arg = "";
 	}
@@ -449,7 +449,7 @@ int serv_delete(char *arg)
 	if (!fn) {
 		if (is_builtin(arg))
 			ERRX(4, "%s is a built-in service.", arg);
-		ERRX(72, FINIT_RCSD " missing on system.");
+		ERRX(72, "%s missing on system.", finit_rcsd);
 	}
 
 	if (!fexist(fn))

src/sm.c

@@ -121,7 +121,7 @@ restart:
 
 	switch (sm->state) {
 	case SM_BOOTSTRAP_STATE:
-		dbg("Bootstrapping all services in runlevel S from %s", FINIT_CONF);
+		dbg("Bootstrapping all services in runlevel S from %s", finit_conf);
 		service_step_all(SVC_TYPE_RUNTASK | SVC_TYPE_SERVICE);
 		sm->state = SM_RUNNING_STATE;
 		break;