Add support for specifying hook file

Signed-off-by: Mattias Andrée <m@maandree.se>

5 files changed, 196 insertions, 38 deletions

diff --git a/src/common.h b/src/common.h
index f5be542..61e5c79 100644
--- a/src/common.h
+++ b/src/common.h
@@ -738,6 +738,14 @@ struct setting_time {
 };
 
 /**
+ * `char *` valued setting with setting source
+ */
+struct setting_str {
+	enum setting_source source; /**< Setting source */
+	char *value;                /**< Setting value */
+};
+
+/**
  * Intermediate settings representation of colour settings
  * (for a non-transitional period) with settings sources
  * used for determining whether settings from the configuration
@@ -807,6 +815,14 @@ struct settings {
 	int until_death;
 
 	/**
+	 * The path to the hook file or hook directory, `NULL`
+	 * if unspecified (search default paths)
+	 * 
+	 * This represents the "hook" setting and "-H" option
+	 */
+	struct setting_str hook_file;
+
+	/**
 	 * Whether the program should preserve preapplied
 	 * colour calibrations
 	 * 
@@ -1183,6 +1199,12 @@ extern int use_fade;
  */
 extern int verbose;
 
+/**
+ * The path to the hook file or hook directory, `NULL`
+ * if unspecified (search default paths)
+ */
+extern char *hook_file;
+
 
 /* backend-direct.c */
 
@@ -1357,11 +1379,14 @@ LIST_RAMPS_STOP_VALUE_TYPES(X, ;);
 /**
  * Load the configuration file
  * 
- * @param  state  Output parameter for the configurations
- * @param  path   The path to the configuration file, or `NULL` if the
- *                application should look for it in the default paths
- */
-void config_ini_init(struct config_ini_state *state, const char *path);
+ * @param   state        Output parameter for the configurations
+ * @param   path         The path to the configuration file, or `NULL` if the
+ *                       application should look for it in the default paths
+ * @param   pathbuf_out  Output parameter for the memory allocated for the
+ *                       return value
+ * @return               The path to the loaded configuration file, `NULL` if none
+ */
+const char *config_ini_init(struct config_ini_state *state, const char *path, char **pathbuf_out);
 
 /**
  * Deallocate the settings loaded
diff --git a/src/config-ini.c b/src/config-ini.c
index d5056dc..13aaa57 100644
--- a/src/config-ini.c
+++ b/src/config-ini.c
@@ -146,12 +146,12 @@ open_config_file(const char *path, const char **path_out, char **pathbuf_out, in
 }
 
 
-void
-config_ini_init(struct config_ini_state *state, const char *path)
+const char *
+config_ini_init(struct config_ini_state *state, const char *path, char **pathbuf_out)
 {
 	struct config_ini_section *section = NULL;
 	struct config_ini_setting *setting;
-	char *line = NULL, *s, *p, *value, *end, *pathbuf;
+	char *line = NULL, *s, *p, *value, *end;
 	char *next_line = NULL, *name;
 	size_t size = 0;
 	ssize_t len = 0; /* initialised to silence false warning from clang */
@@ -159,10 +159,11 @@ config_ini_init(struct config_ini_state *state, const char *path)
 	int should_close;
 
 	state->sections = NULL;
+	*pathbuf_out = NULL;
 
-	f = open_config_file(path, &path, &pathbuf, &should_close);
+	f = open_config_file(path, &path, pathbuf_out, &should_close);
 	if (!f)
-		return;
+		return NULL;
 
 #ifndef WINDOWS
 again:
@@ -227,10 +228,11 @@ again:
 		eprintf("getline %s:", path);
 	}
 
-	free(pathbuf);
 	free(line);
 	if (should_close)
 		fclose(f);
+
+	return path;
 }
 
 
diff --git a/src/config.c b/src/config.c
index 7843c08..29c5a53 100644
--- a/src/config.c
+++ b/src/config.c
@@ -30,7 +30,7 @@ usage_no_exit(FILE *f)
 {
 	fprintf(f, _("Usage: %s %s\n"), argv0,
 	        _("[-b brightness] [-c config-file] [-D | +D] [-E | +E | -e elevations] "
-	          "[-g gamma] [-l latitude:longitude | -l provider[:options]] "
+	          "[-g gamma] [-H hook-file] [-l latitude:longitude | -l provider[:options]] "
 	          "[-m method[:options]] [-P | +P] [-r | +r] [-dv] "
 	          "[-O temperature | -o | -p | -t temperature | -x] | -h | -V"));
 }
@@ -54,6 +54,7 @@ enum program_mode mode = PROGRAM_MODE_CONTINUAL;
 int preserve_gamma;
 int use_fade;
 int verbose = 0;
+char *hook_file;
 
 
 /**
@@ -78,6 +79,7 @@ print_help(void)
 	printf(_("  -e day:night             Select solar elevation thresholds for day and night (Default: %g:%g)\n"),
 	                                     DEFAULT_HIGH_ELEVATION, DEFAULT_LOW_ELEVATION);
 	printf(_("  -g day:night             Additional gamma correction (Default: 1:1:1:1:1:1)\n"));
+	printf(_("  -H hook-file             Select hook file or directrory\n"));
 	printf(_("  -h                       Display this help message\n"));
 	printf(_("  -l lat:lon               Specific geographical location\n"));
 	printf(_("  -l provider[:options]    Select location provider to get geographical location\n"));
@@ -657,6 +659,7 @@ load_defaults(struct settings *settings)
 	settings->night.gamma.value[1] = DEFAULT_NIGHT_GAMMA;
 	settings->night.gamma.value[2] = DEFAULT_NIGHT_GAMMA;
 
+	settings->hook_file.value = NULL;
 	settings->preserve_gamma.value = 1;
 	settings->use_fade.value = 1;
 
@@ -716,6 +719,12 @@ load_from_cmdline(struct settings *settings, int argc, char *argv[])
 		set_gamma(ARG(), &settings->day.gamma, &settings->night.gamma, NULL);
 		break;
 
+	case 'H':
+		settings->hook_file.source |= SETTING_CMDLINE;
+		free(settings->hook_file.value);
+		settings->hook_file.value = ARG();
+		break;
+
 	case 'h':
 		print_help();
 		exit(0);
@@ -899,6 +908,15 @@ load_from_config_ini(struct settings *settings, const char *key, char *value)
 		if (settings->use_fade.source <= SETTING_CONFIGFILE)
 			settings->use_fade.value = get_boolean(value, key);
 
+	} else if (!strcasecmp(key, "hook")) {
+		if (settings->hook_file.source & SETTING_CONFIGFILE)
+			weprintf(_("`hook' setting specified multiple times in configuration file."));
+		settings->hook_file.source |= SETTING_CONFIGFILE;
+		if (settings->hook_file.source <= SETTING_CONFIGFILE) {
+			free(settings->hook_file.value);
+			settings->hook_file.value = estrdup(value);
+		}
+
 	} else if (!strcasecmp(key, "preserve-gamma")) {
 		if (settings->preserve_gamma.source & SETTING_CONFIGFILE)
 			weprintf(_("`preserve-gamma' setting specified multiple times in configuration file."));
@@ -955,8 +973,11 @@ load_settings(struct settings *settings, int argc, char *argv[])
 	struct config_ini_section *section;
 	struct config_ini_setting *setting;
 	const struct time_period *first, *current;
+	const char *conf_path, *p;
+	char *conf_pathbuf, *s;
 	int i, j, n;
 	time_t duration;
+	size_t len;
 
 	/* Clear unused bit so they do not interfere with comparsion */
 	memset(&day_settings, 0, sizeof(day_settings));
@@ -965,7 +986,7 @@ load_settings(struct settings *settings, int argc, char *argv[])
 	/* Load settings; some validation takes place */
 	load_defaults(settings);
 	load_from_cmdline(settings, argc, argv);
-	config_ini_init(&settings->config, settings->config_file);
+	conf_path = config_ini_init(&settings->config, settings->config_file, &conf_pathbuf);
 	if ((section = config_ini_get_section(&settings->config, "redshift")))
 		for (setting = section->settings; setting; setting = setting->next)
 			load_from_config_ini(settings, setting->name, setting->value);
@@ -1014,9 +1035,67 @@ load_settings(struct settings *settings, int argc, char *argv[])
 		goto settings_published;
 	}
 
+	/* Make hook file absolute if set from config file (relative to config file) */
+	if (settings->hook_file.source == SETTING_CONFIGFILE && conf_path) {
+#ifdef WINDOWS
+		/* Regular absolute path */
+		if (isalpha(settings->hook_file.value[0]) && settings->hook_file.value[1] == ':')
+			goto absolute_hook_path;
+		/* Absolute extended path or network path (relative extended paths do not exist) */
+		if (settings->hook_file.value[0] == '\\' && settings->hook_file.value[1] == '\\')
+			goto absolute_hook_path;
+		/* Path relative to root */
+		if (settings->hook_file.value[0] == '\\' || settings->hook_file.value[0] == '/') {
+			/* This is safe as we know that `conf_path` is a valid path */
+			if (isalpha(conf_path[0]) && conf_path[1] == ':') {
+				p = &conf_path[3];
+				goto base_found;
+			} else if (conf_path[0] == '\\' && conf_path[1] == '\\') {
+				p = &conf_path[2];
+				while (*p == '\\')
+					p++;
+				while (*p != '/' && *p != '\\')
+					p++;
+				goto base_found;
+			}
+		}
+#else
+		if (settings->hook_file.value[0] == '/')
+			goto absolute_hook_path;
+#endif
+		p = strrchr(conf_path, '/');
+		p = p ? &p[1] : conf_path;
+#ifdef WINDOWS
+		if (strrchr(p, '\\'))
+			p = &strrchr(p, '\\')[1];
+	base_found:
+#endif
+		len = (size_t)(p - conf_path);
+		s = emalloc(len + strlen(settings->hook_file.value) + 1U);
+		memcpy(s, conf_path, len);
+		stpcpy(&s[len], settings->hook_file.value);
+		free(settings->hook_file.value);
+		settings->hook_file.value = s;
+#ifdef WINDOWS
+		/* Used extended path is too long */
+		if (settings->hook_file.value[0] != '\\' && (len = strlen(settings->hook_file.value)) >= 260) {
+			/* We have already made sure the path is absolute, so \ prefix is always extended or network path */
+			settings->hook_file.value = erealloc(settings->hook_file.value, len + sizeof("\\\\?\\"));
+			memmove(&settings->hook_file.value[4], &settings->hook_file.value, len + 1U);
+			settings->hook_file.value[0] = '\\';
+			settings->hook_file.value[1] = '\\';
+			settings->hook_file.value[2] = '?';
+			settings->hook_file.value[3] = '\\';
+		}
+#endif
+	}
+	free(conf_pathbuf);
+absolute_hook_path:
+
 	/* Publish loaded settings */
 	if (mode == PROGRAM_MODE_ONE_SHOT && settings->until_death)
 		mode = PROGRAM_MODE_UNTIL_DEATH;
+	hook_file = settings->hook_file.value, settings->hook_file.value = NULL;
 	preserve_gamma = settings->preserve_gamma.value;
 	use_fade = settings->use_fade.value;
 	disable ^= settings->disabled.value;
diff --git a/src/hooks.c b/src/hooks.c
index be02b18..96f6f83 100644
--- a/src/hooks.c
+++ b/src/hooks.c
@@ -111,6 +111,45 @@ open_hooks_dir(const char **path_out, char **pathbuf_out)
 
 
 /**
+ * Run hook file
+ *
+ * @param  path  The path to the hook file
+ * @param  argv  `NULL` terminated list of command line arguments
+ *               for the hooks; must contain an unused initial slot,
+ *               which the function will use to provide the zeroth
+ *               argument
+ */
+static void
+run_hook(const char *path, const char *argv[])
+{
+#ifdef WINDOWS
+	/* TODO [Windows] hooks are not support on Windows */
+#else
+	switch (fork()) {
+	case -1:
+		weprintf("fork:");
+		break;
+
+	case 0:
+		if (dup2(STDOUT_FILENO, STDERR_FILENO) != STDERR_FILENO) {
+			weprintf("dup2 <stdout> <stderr>:");
+			_exit(1);
+		}
+		argv[0] = path;
+		execv(path, (const void *)argv);
+		if (errno != EACCES)
+			weprintf("execv %s:", path);
+		_exit(1);
+
+	default:
+		/* SIGCHLD is ignored */
+		break;
+	}
+#endif
+}
+
+
+/**
  * Run hooks
  *
  * @param  argv  `NULL` terminated list of command line arguments
@@ -122,13 +161,44 @@ static void
 run_hooks(const char *argv[])
 {
 	static int looked_up_dir = 0;
+	static int hook_file_is_regular = 0;
+	static int hook_file_checked = 0;
 
 	DIR *dir;
 	struct dirent *f;
 	size_t required;
 	const char *dirpath_static;
 
-	if (!looked_up_dir) {
+	if (hook_file_is_regular) {
+		goto run_hook_file;
+
+	} else if (hook_file) {
+		if (!hook_file_checked) {
+			hook_file_checked = 1;
+			if (!strcmp(hook_file, "/dev/null") ||
+			    !strcmp(hook_file, "/var/empty") ||
+			    !strcmp(hook_file, "/var/empty/"))
+				    goto no_hooks;
+		}
+
+		dir = opendir(hook_file);
+		if (!dir) {
+			if (errno == ENOTDIR) {
+				hook_file_is_regular = 1;
+			run_hook_file:
+				run_hook(hook_file, argv);
+				return;
+			}
+			weprintf("opendir %s:", hook_file);
+		no_hooks:
+			free(hook_file);
+			hook_file = NULL;
+			looked_up_dir = 1;
+			dirpath = NULL;
+			return;
+		}
+
+	} else if (!looked_up_dir) {
 		looked_up_dir = 1;
 		dir = open_hooks_dir(&dirpath_static, &dirpath);
 		if (!dir)
@@ -137,6 +207,7 @@ run_hooks(const char *argv[])
 			dirpath = estrdup(dirpath_static);
 		dirpathsize = dirpathlen = strlen(dirpath);
 		atexit(&cleanup);
+
 	} else if (dirpath) {
 		dir = opendir(dirpath);
 		if (!dir) {
@@ -144,6 +215,7 @@ run_hooks(const char *argv[])
 			cleanup();
 			return;
 		}
+
 	} else {
 		return;
 	}
@@ -155,32 +227,11 @@ run_hooks(const char *argv[])
 		required = dirpathlen + sizeof("/") + strlen(f->d_name);
 		if (required > dirpathsize)
 			dirpath = erealloc(dirpath, dirpathsize = required);
+		stpcpy(stpcpy(&dirpath[dirpathlen], "/"), f->d_name);
 
-#ifdef WINDOWS
-		/* TODO [Windows] hooks are not support on Windows */
-#else
-		switch (fork()) {
-		case -1:
-			weprintf("fork:");
-			break;
-
-		case 0:
-			if (dup2(STDOUT_FILENO, STDERR_FILENO) != STDERR_FILENO) {
-				weprintf("dup2 <stdout> <stderr>:");
-				_exit(1);
-			}
-			stpcpy(stpcpy(&dirpath[dirpathlen], "/"), f->d_name);
-			argv[0] = dirpath;
-			execv(dirpath, (const void *)argv);
-			if (errno != EACCES)
-				weprintf("execv %s:", dirpath);
-			_exit(1);
+		run_hook(dirpath, argv);
 
-		default:
-			/* SIGCHLD is ignored */
-			break;
-		}
-#endif
+		dirpath[dirpathlen] = '\0';
 	}
 
 	if (errno)
diff --git a/src/redshift.c b/src/redshift.c
index bcd9db9..5bc172e 100644
--- a/src/redshift.c
+++ b/src/redshift.c
@@ -538,5 +538,6 @@ out:
 		provider->free(provider_state);
 	if (method_state)
 		method->free(method_state);
+	free(hook_file);
 	return 0;
 }