Refactor XDG base directory iterator API

Finally something more reasonable for call sites.

5 files changed, 65 insertions, 73 deletions

diff --git a/bounce.c b/bounce.c
index 7f0add5..12cacf5 100644
--- a/bounce.c
+++ b/bounce.c
@@ -139,10 +139,10 @@ static void unveilTarget(const char *path, const char *mode) {
 }
 
 static void unveilConfig(const char *path) {
-	const char *dirs = NULL;
-	for (const char *abs; NULL != (abs = configPath(&dirs, path));) {
-		unveilParent(abs, "r");
-		unveilTarget(abs, "r");
+	char buf[PATH_MAX];
+	for (int i = 0; configPath(buf, sizeof(buf), path, i); ++i) {
+		unveilParent(buf, "r");
+		unveilTarget(buf, "r");
 	}
 }
 #endif /* __OpenBSD__ */
diff --git a/bounce.h b/bounce.h
index 295a448..8e6ed09 100644
--- a/bounce.h
+++ b/bounce.h
@@ -249,8 +249,8 @@ void stateSync(struct Client *client);
 const char *stateNick(void);
 const char *stateEcho(void);
 
-const char *configPath(const char **dirs, const char *path);
-const char *dataPath(const char **dirs, const char *path);
+char *configPath(char *buf, size_t cap, const char *path, int i);
+char *dataPath(char *buf, size_t cap, const char *path, int i);
 FILE *configOpen(const char *path, const char *mode);
 FILE *dataOpen(const char *path, const char *mode);
 
diff --git a/local.c b/local.c
index 35286b3..ece94ca 100644
--- a/local.c
+++ b/local.c
@@ -27,6 +27,7 @@
 
 #include <err.h>
 #include <errno.h>
+#include <limits.h>
 #include <netdb.h>
 #include <netinet/in.h>
 #include <stdbool.h>
@@ -52,24 +53,22 @@ int localConfig(
 	if (!config) errx(EX_SOFTWARE, "tls_config_new");
 
 	int error;
-	const char *dirs = NULL;
-	for (const char *path; NULL != (path = configPath(&dirs, cert));) {
-		error = tls_config_set_cert_file(config, path);
+	char buf[PATH_MAX];
+	for (int i = 0; configPath(buf, sizeof(buf), cert, i); ++i) {
+		error = tls_config_set_cert_file(config, buf);
 		if (!error) break;
 	}
 	if (error) goto fail;
 
-	dirs = NULL;
-	for (const char *path; NULL != (path = configPath(&dirs, priv));) {
-		error = tls_config_set_key_file(config, path);
+	for (int i = 0; configPath(buf, sizeof(buf), priv, i); ++i) {
+		error = tls_config_set_key_file(config, buf);
 		if (!error) break;
 	}
 	if (error) goto fail;
 
 	if (ca) {
-		dirs = NULL;
-		for (const char *path; NULL != (path = configPath(&dirs, ca));) {
-			error = tls_config_set_ca_file(config, path);
+		for (int i = 0; configPath(buf, sizeof(buf), ca, i); ++i) {
+			error = tls_config_set_ca_file(config, buf);
 			if (!error) break;
 		}
 		if (error) goto fail;
diff --git a/server.c b/server.c
index 552f521..0c6bccc 100644
--- a/server.c
+++ b/server.c
@@ -27,6 +27,7 @@
 
 #include <assert.h>
 #include <err.h>
+#include <limits.h>
 #include <netdb.h>
 #include <netinet/in.h>
 #include <stdarg.h>
@@ -47,6 +48,7 @@ void serverConfig(
 	bool insecure, const char *trust, const char *cert, const char *priv
 ) {
 	int error = 0;
+	char buf[PATH_MAX];
 	config = tls_config_new();
 	if (!config) errx(EX_SOFTWARE, "tls_config_new");
 
@@ -54,32 +56,30 @@ void serverConfig(
 		tls_config_insecure_noverifycert(config);
 		tls_config_insecure_noverifyname(config);
 	}
+
 	if (trust) {
 		tls_config_insecure_noverifyname(config);
-		const char *dirs = NULL;
-		for (const char *path; NULL != (path = configPath(&dirs, trust));) {
-			error = tls_config_set_ca_file(config, path);
+		for (int i = 0; configPath(buf, sizeof(buf), trust, i); ++i) {
+			error = tls_config_set_ca_file(config, buf);
 			if (!error) break;
 		}
 		if (error) errx(EX_NOINPUT, "%s: %s", trust, tls_config_error(config));
 	}
 
 	if (cert) {
-		const char *dirs = NULL;
-		for (const char *path; NULL != (path = configPath(&dirs, cert));) {
+		for (int i = 0; configPath(buf, sizeof(buf), cert, i); ++i) {
 			if (priv) {
-				error = tls_config_set_cert_file(config, path);
+				error = tls_config_set_cert_file(config, buf);
 			} else {
-				error = tls_config_set_keypair_file(config, path, path);
+				error = tls_config_set_keypair_file(config, buf, buf);
 			}
 			if (!error) break;
 		}
 		if (error) errx(EX_NOINPUT, "%s: %s", cert, tls_config_error(config));
 	}
 	if (priv) {
-		const char *dirs = NULL;
-		for (const char *path; NULL != (path = configPath(&dirs, priv));) {
-			error = tls_config_set_key_file(config, path);
+		for (int i = 0; configPath(buf, sizeof(buf), priv, i); ++i) {
+			error = tls_config_set_key_file(config, buf);
 			if (!error) break;
 		}
 		if (error) errx(EX_NOINPUT, "%s: %s", priv, tls_config_error(config));
diff --git a/xdg.c b/xdg.c
index 67f4ab0..5147471 100644
--- a/xdg.c
+++ b/xdg.c
@@ -59,80 +59,73 @@ static const struct Base Data = {
 	.defDirs = "/usr/local/share:/usr/share",
 };
 
-static const char *
-basePath(struct Base base, const char **dirs, const char *path) {
-	static char buf[PATH_MAX];
-
-	if (*dirs) {
-		if (!**dirs) return NULL;
-		size_t len = strcspn(*dirs, ":");
-		snprintf(buf, sizeof(buf), "%.*s/" SUBDIR "/%s", (int)len, *dirs, path);
-		*dirs += len;
-		if (**dirs) *dirs += 1;
+static char *basePath(
+	struct Base base, char *buf, size_t cap, const char *path, int i
+) {
+	if (path[strspn(path, ".")] == '/') {
+		if (i > 0) return NULL;
+		snprintf(buf, cap, "%s", path);
 		return buf;
 	}
 
-	if (path[strspn(path, ".")] == '/') {
-		*dirs = "";
-		return path;
+	if (i > 0) {
+		const char *dirs = getenv(base.envDirs);
+		if (!dirs) dirs = base.defDirs;
+		for (; i > 1; --i) {
+			dirs += strcspn(dirs, ":");
+			dirs += (*dirs == ':');
+		}
+		if (!*dirs) return NULL;
+		snprintf(
+			buf, cap, "%.*s/" SUBDIR "/%s",
+			(int)strcspn(dirs, ":"), dirs, path
+		);
+		return buf;
 	}
 
-	*dirs = getenv(base.envDirs);
-	if (!*dirs) *dirs = base.defDirs;
-
 	const char *home = getenv("HOME");
 	const char *baseHome = getenv(base.envHome);
 	if (baseHome) {
-		snprintf(buf, sizeof(buf), "%s/" SUBDIR "/%s", baseHome, path);
+		snprintf(buf, cap, "%s/" SUBDIR "/%s", baseHome, path);
 	} else if (home) {
-		snprintf(
-			buf, sizeof(buf), "%s/%s/" SUBDIR "/%s",
-			home, base.defHome, path
-		);
+		snprintf(buf, cap, "%s/%s/" SUBDIR "/%s", home, base.defHome, path);
 	} else {
-		errx(EX_CONFIG, "HOME unset");
+		errx(EX_USAGE, "HOME unset");
 	}
 	return buf;
 }
 
-const char *configPath(const char **dirs, const char *path) {
-	return basePath(Config, dirs, path);
+char *configPath(char *buf, size_t cap, const char *path, int i) {
+	return basePath(Config, buf, cap, path, i);
 }
 
-const char *dataPath(const char **dirs, const char *path) {
-	return basePath(Data, dirs, path);
+char *dataPath(char *buf, size_t cap, const char *path, int i) {
+	return basePath(Data, buf, cap, path, i);
 }
 
 FILE *configOpen(const char *path, const char *mode) {
-	const char *dirs = NULL;
-	for (const char *abs; NULL != (abs = configPath(&dirs, path));) {
-		FILE *file = fopen(abs, mode);
+	char buf[PATH_MAX];
+	for (int i = 0; configPath(buf, sizeof(buf), path, i); ++i) {
+		FILE *file = fopen(buf, mode);
 		if (file) return file;
-		if (errno != ENOENT) warn("%s", abs);
+		if (errno != ENOENT) warn("%s", buf);
 	}
-	dirs = NULL;
-	warn("%s", configPath(&dirs, path));
+	warn("%s", configPath(buf, sizeof(buf), path, 0));
 	return NULL;
 }
 
-static void dataMkdir(const char *path) {
-	const char *dirs = NULL;
-	path = dataPath(&dirs, path);
-	int error = mkdir(path, S_IRWXU);
-	if (error && errno != EEXIST) warn("%s", path);
-}
-
 FILE *dataOpen(const char *path, const char *mode) {
-	const char *dirs = NULL;
-	for (const char *abs; NULL != (abs = dataPath(&dirs, path));) {
-		FILE *file = fopen(abs, mode);
+	char buf[PATH_MAX];
+	for (int i = 0; dataPath(buf, sizeof(buf), path, i); ++i) {
+		FILE *file = fopen(buf, mode);
 		if (file) return file;
-		if (errno != ENOENT) warn("%s", abs);
+		if (errno != ENOENT) warn("%s", buf);
+	}
+	if (mode[0] != 'r') {
+		int error = mkdir(dataPath(buf, sizeof(buf), "", 0), S_IRWXU);
+		if (error && errno != EEXIST) warn("%s", buf);
 	}
-	if (mode[0] != 'r') dataMkdir("");
-	dirs = NULL;
-	path = dataPath(&dirs, path);
-	FILE *file = fopen(path, mode);
-	if (!file) warn("%s", path);
+	FILE *file = fopen(dataPath(buf, sizeof(buf), path, 0), mode);
+	if (!file) warn("%s", buf);
 	return file;
 }