Teach minecproxy to use same dirs as minecctl, step 1

4 files changed, 219 insertions, 3 deletions

diff --git a/shared/config-parser.c b/shared/config-parser.c
index 4dc446c..909c558 100644
--- a/shared/config-parser.c
+++ b/shared/config-parser.c
@@ -14,7 +14,6 @@
 #include "config-parser.h"
 #include "server-config-options.h"
 #include "server-properties-options.h"
-#include "config.h"
 
 static bool handle_addrinfo_results(struct addrinfo *results,
 				    struct list_head *target_list,
diff --git a/shared/systemd.c b/shared/systemd.c
index c45c7c5..4edc055 100644
--- a/shared/systemd.c
+++ b/shared/systemd.c
@@ -7,7 +7,6 @@
 #include "utils.h"
 #include "config-parser.h"
 #include "systemd.h"
-#include "config.h"
 
 static sd_bus *bus = NULL;
 static bool bus_failed = false;
diff --git a/shared/utils.c b/shared/utils.c
index 99fcaa3..f41a8a1 100644
--- a/shared/utils.c
+++ b/shared/utils.c
@@ -5,6 +5,7 @@
 #include <limits.h>
 #include <arpa/inet.h>
 #include <string.h>
+#include <sys/stat.h>
 #include <sys/types.h>
 #include <dirent.h>
 #include <fcntl.h>
@@ -14,11 +15,156 @@
 #include <netinet/tcp.h>
 #include <inttypes.h>
 #include <stdarg.h>
+#include <pwd.h>
 
 #include "utils.h"
 
 unsigned debug_mask = 0;
 
+static const char *get_homedir()
+{
+	const char *e;
+        struct passwd *passwd;
+        uid_t uid;
+
+	e = getenv("HOME");
+	if (e && e[0] == '/')
+		return e;
+
+	uid = getuid();
+	if (uid == 0)
+		return "/root";
+
+        passwd = getpwuid(uid);
+	if (passwd && passwd->pw_dir[0] == '/')
+		return passwd->pw_dir;
+
+	return NULL;
+}
+
+int open_subdir(int dfd, const char *subdir, bool nofail)
+{
+	int sfd;
+
+	if (nofail && mkdirat(dfd, subdir, 0777) < 0 && errno != EEXIST) {
+		error("Unable to create subdirectory %s: %m", subdir);
+		return -1;
+	}
+
+	sfd = openat(dfd, subdir, O_PATH | O_CLOEXEC | O_DIRECTORY);
+	if (sfd < 0 && nofail)
+		error("Unable to open subdirectory %s: %m", subdir);
+
+	return sfd;
+}
+
+int open_xdg_dir(const char *envname, const char *altpath, bool nofail,
+		 char **rpath)
+{
+        const char *e;
+	const char *h;
+	int dfd, hfd;
+
+	e = getenv(envname);
+	if (e && e[0] == '/') {
+		dfd = open(e, O_PATH | O_CLOEXEC | O_DIRECTORY);
+		if (dfd < 0)
+			error("Unable to open $%s(%s): %m", envname, e);
+		else if (rpath) {
+			*rpath = xstrdup(e);
+			if (!rpath) {
+				error("xstrdup: %m");
+				close(dfd);
+				return -1;
+			}
+		}
+		return dfd;
+	}
+
+	h = get_homedir();
+	if (!h) {
+		error("Unable to determine home directory");
+		return -1;
+	}
+
+	hfd = open(h, O_PATH | O_CLOEXEC | O_DIRECTORY);
+	if (hfd < 0) {
+		error("Unable to open $HOME(%s): %m", h);
+		return -1;
+	}
+
+	dfd = open_subdir(hfd, altpath, nofail);
+	close(hfd);
+
+	if (dfd >= 0 && rpath) {
+		*rpath = xstrcat(h, "/", altpath, NULL);
+		if (!*rpath) {
+			error("xstrcat: %m");
+			close(dfd);
+			return -1;
+		}
+	}
+	return dfd;
+}
+
+DIR *__open_dir(const char *user_override,
+		int (*base_dir)(bool nofail, char **rpath),
+		const char *fallback, char **rpath)
+{
+	_cleanup_close_ int xfd = -1;
+	_cleanup_close_ int mfd = -1;
+	_cleanup_free_ char *tmp = NULL;
+	DIR *dir;
+
+	/* First, use explicitly set path... */
+	if (user_override) {
+		dir = opendir(user_override);
+		if (dir && rpath) {
+			*rpath = xstrdup(user_override);
+			if (!*rpath) {
+				closedir(dir);
+				return NULL;
+			}
+		}
+		return dir;
+	}
+
+	/* ...second, attempt per-user config dir... */
+	xfd = base_dir(false, &tmp);
+	if (xfd < 0)
+		goto fallback;
+
+	mfd = openat(xfd, "minecproxy", O_CLOEXEC | O_DIRECTORY | O_RDONLY);
+	if (mfd < 0)
+		goto fallback;
+
+	dir = fdopendir(mfd);
+	if (dir)
+		mfd = -1;
+
+	if (rpath) {
+		*rpath = xstrcat(tmp, "/minecproxy", NULL);
+		if (!*rpath) {
+			closedir(dir);
+			return NULL;
+		}
+	}
+
+	return dir;
+
+	/* ...third, fallback on the system dir */
+fallback:
+	dir = opendir(fallback);
+	if (dir && rpath) {
+		*rpath = xstrdup(fallback);
+		if (!*rpath) {
+			closedir(dir);
+			return NULL;
+		}
+	}
+	return dir;
+}
+
 const char *ansi_red = "";
 const char *ansi_green = "";
 const char *ansi_yellow = "";
@@ -252,3 +398,33 @@ char *xsprintf(size_t *rlen, const char *fmt, ...)
 
 	return str;
 }
+
+char *xstrcat(const char *a, ...) {
+	size_t len;
+	const char *b;
+	char *str;
+	char *to;
+	va_list ap;
+
+	if (!a)
+		return NULL;
+
+	len = strlen(a) + 1;
+
+	va_start(ap, a);
+	while ((b = va_arg(ap, const char *)))
+		len += strlen(b);
+	va_end(ap);
+
+	str = zmalloc(len);
+	if (!str)
+		return NULL;
+	
+	to = stpcpy(str, a);
+	va_start(ap, a);
+	while ((b = va_arg(ap, const char *)))
+		to = stpcpy(to, b);
+	va_end(ap);
+
+	return str;
+}
diff --git a/shared/utils.h b/shared/utils.h
index 1291d21..b6bf51c 100644
--- a/shared/utils.h
+++ b/shared/utils.h
@@ -8,9 +8,11 @@
 #include <stdlib.h>
 #include <linux/if_packet.h>
 #include <sys/socket.h>
+#include <sys/types.h>
 #include <netinet/in.h>
 #include <netinet/ip.h>
 #include <unistd.h>
+#include <dirent.h>
 
 extern unsigned debug_mask;
 
@@ -42,6 +44,7 @@ extern unsigned debug_mask;
 #include "list.h"
 #include "debug.h"
 #include "external.h"
+#include "config.h"
 #include "ansi-colors.h"
 
 /* Length of longest DNS name = 253 + trailing dot */
@@ -68,6 +71,37 @@ struct saddr {
 	struct list_head list;
 };
 
+int open_subdir(int dfd, const char *subdir, bool nofail);
+
+int open_xdg_dir(const char *envname, const char *altpath, bool nofail,
+		 char **rpath);
+
+static inline int open_xdg_data_dir(bool nofail, char **rpath)
+{
+	return open_xdg_dir("XDG_DATA_HOME", ".local/share", nofail, rpath);
+}
+
+static inline int open_xdg_cfg_dir(bool nofail, char **rpath)
+{
+	return open_xdg_dir("XDG_CONFIG_HOME", ".config", nofail, rpath);
+}
+
+DIR *__open_dir(const char *user_override,
+		int (*base_dir)(bool nofail, char **rpath),
+		const char *fallback, char **rpath);
+
+static inline DIR *open_cfg_dir(const char *user_override, char **rpath)
+{
+	return __open_dir(user_override, open_xdg_cfg_dir, DEFAULT_CFG_DIR,
+			  rpath);
+}
+
+static inline DIR *open_data_dir(const char *user_override, char **rpath)
+{
+	return __open_dir(user_override, open_xdg_data_dir, DEFAULT_DATA_DIR,
+			  rpath);
+}
+
 void enable_colors();
 
 void free_password(char **password);
@@ -91,6 +125,8 @@ int strtou16_strict(const char *str, uint16_t *result);
 
 char *xsprintf(size_t *rlen, const char *fmt, ...) _printf_(2, 3);
 
+char *xstrcat(const char *a, ...);
+
 static inline bool empty_str(const char *str)
 {
 	if (!str || str[0] == '\0')
@@ -136,7 +172,7 @@ static inline bool strcaseeq(const char *a, const char *b)
 
 static inline void closep(int *fd)
 {
-	if (*fd && *fd >= 0)
+	if (fd && *fd >= 0)
 		close(*fd);
 }
 #define _cleanup_close_ _cleanup_(closep)
@@ -146,4 +182,10 @@ static inline void freep(void *p) {
 }
 #define _cleanup_free_ _cleanup_(freep)
 
+static inline void fclosep(FILE **f) {
+	if (f && *f)
+		fclose(*f);
+}
+#define _cleanup_fclose_ _cleanup_(fclosep)
+
 #endif