Store score file in home directory

BSD games are traditionally designed for multiuser systems and thus
write their data to /var/games, using setgid to prevent tampering.
Switch to a single-user design, writing the score file to the user’s
home directory. $XDGDATAHOME/rogue will will be used if $XDGDATAHOME
is defined. Otherwise, data will be written to a $HOME/.rogue directory.
This also improves the makefile by making header files a dependency of
objects.

6 files changed, 163 insertions, 47 deletions

diff --git a/Makefile b/Makefile
index 5379b21..faaf561 100644
--- a/Makefile
+++ b/Makefile
@@ -7,10 +7,13 @@ BIN_DIR:=$(PREFIX)/bin
 CPPFLAGS+=-DUNIX -DUNIX_SYSV
 SRCS=	hit.c init.c inventory.c level.c machdep.c main.c \
 	message.c monster.c move.c object.c pack.c play.c random.c ring.c \
-	room.c save.c score.c spec_hit.c throw.c trap.c use.c zap.c
+	room.c save.c score.c spec_hit.c throw.c trap.c use.c zap.c \
+	pathnames.c
 OBJS=	hit.o init.o inventory.o level.o machdep.o main.o \
 	message.o monster.o move.o object.o pack.o play.o random.o ring.o \
-	room.o save.o score.o spec_hit.o throw.o trap.o use.o zap.o
+	room.o save.o score.o spec_hit.o throw.o trap.o use.o zap.o \
+	pathnames.o
+HEADERS=rogue.h pathnames.h
 DPADD=	${LIBCURSES} ${LIBTERMINFO}
 LDADD=	-lcurses -lterminfo
 HIDEGAME=hidegame
@@ -24,6 +27,8 @@ COPTS.score.c+=	${CC_WNO_FORMAT_TRUNCATION}
 $(PROG): $(OBJS)
 	cc -o $@ -lcurses $(OBJS)
 
+$(OBJS): $(HEADERS)
+
 .PHONY: install
 install: $(PROG)
 	chmod 755 $(PROG)
diff --git a/machdep.c b/machdep.c
index e6d6292..4d5d334 100644
--- a/machdep.c
+++ b/machdep.c
@@ -424,40 +424,6 @@ md_exit(int status)
 	exit(status);
 }
 
-/* md_lock():
- *
- * This function is intended to give the user exclusive access to the score
- * file.  It does so by flock'ing the score file.  The full path name of the
- * score file should be defined for any particular site in rogue.h.  The
- * constants _PATH_SCOREFILE defines this file name.
- *
- * When the parameter 'l' is non-zero (true), a lock is requested.  Otherwise
- * the lock is released.
- */
-
-void
-md_lock(boolean l)
-{
-	static int fd = -1;
-	short tries;
-
-	if (l) {
-		setegid(egid);
-		if ((fd = open(_PATH_SCOREFILE, O_RDONLY)) < 1) {
-			setegid(gid);
-			messagef(0, "cannot lock score file");
-			return;
-		}
-		setegid(gid);
-		for (tries = 0; tries < 5; tries++)
-			if (!flock(fd, LOCK_EX|LOCK_NB))
-				return;
-	} else {
-		(void)flock(fd, LOCK_UN|LOCK_NB);
-		(void)close(fd);
-	}
-}
-
 /* md_shell():
  *
  * This function spawns a shell for the user to use.  When this shell is
diff --git a/pathnames.c b/pathnames.c
new file mode 100644
index 0000000..e6d9117
--- /dev/null
+++ b/pathnames.c
@@ -0,0 +1,142 @@
+#include <stdlib.h>
+#include <pwd.h>
+#include <stdbool.h>
+#include <sys/stat.h>
+#include <errno.h>
+#include <stdio.h>
+#include "pathnames.h"
+#include "rogue.h"
+
+#define XDG_DIR "rogue"
+#define DOTFILE_DIR ".rogue"
+#define SCORE_FILE "scores"
+
+static char *get_prog_dir_path(void);
+static char *get_score_path(void);
+static int ensure_prog_dir(void);
+
+/*
+ * Opens the score file for reading and writing and returns a file pointer.
+ * Returns NULL on error.
+ */
+FILE *
+open_score_file(void) {
+	if (ensure_prog_dir() == -1) {
+		printf("Failed to ensure directory\n");
+		return NULL;
+	}
+
+	char *path = get_score_path();
+	FILE *fp = fopen(path, "r+");
+	if (!fp && errno == ENOENT) {
+		fp = fopen(path, "w+");
+	}
+	free(path);
+
+	if (!fp) {
+		printf("Failed to open file %s\n", path);
+	}
+	return fp;
+}
+
+/*
+ * Returns the path to the program data directory. The caller is responsible
+ * for freeing the returned memory.
+ */
+static
+char *
+get_prog_dir_path(void) {
+	/*
+	 * Use $XDG_DATA_HOME if defined, or the user's home directory
+	 * otherwise.
+	 */
+	char *data_dir = getenv("XDG_DATA_HOME");
+	char *dir;
+	if (data_dir) {
+		dir = XDG_DIR;
+	} else {
+		dir = DOTFILE_DIR;
+		data_dir = getenv("HOME");
+		if (!data_dir) {
+			data_dir = getpwuid(getuid())->pw_dir;
+		}
+	}
+
+	size_t len = strlen(data_dir) + strlen(dir) + 1;
+	bool add_slash = false;
+	if (data_dir[strlen(data_dir) - 1] != '/') {
+		len += 1;
+		add_slash = true;
+	}
+
+	char *buf = malloc(len);
+	strlcpy(buf, data_dir, len);
+	if (add_slash) {
+		strlcat(buf, "/", len);
+	}
+	strlcat(buf, dir, len);
+
+	return buf;
+}
+
+/*
+ * Returns the path to the score file. The caller is repsonsible for freeing
+ * the returned memory.
+ */
+static
+char *
+get_score_path(void)
+{
+	char *dir = get_prog_dir_path();
+
+	// Account for slash after directory and trailing NULL.
+	size_t len = strlen(dir) + strlen(SCORE_FILE) + 2;
+
+	char *buf = malloc(len);
+	strlcpy(buf, dir, len);
+	strlcat(buf, "/", len);
+	strlcat(buf, SCORE_FILE, len);
+
+	free(dir);
+
+	return buf;
+}
+
+/*
+ * Ensures that the program data directory exists. Returns 0 on success or -1
+ * if an error occurs.
+ */
+static
+int
+ensure_prog_dir(void) {
+	int ret;
+	char *path = get_prog_dir_path();
+	struct stat s = {0};
+	int err = stat(path, &s);
+
+	// If file does not exist, create the directory.
+	if (err && errno == ENOENT) {
+		ret = mkdir(path, 0755);
+		goto cleanup;
+	}
+
+	// If file does exist and stat() returned an error, bail out.
+	if (err) {
+		ret = err;
+		goto cleanup;
+	}
+
+	// If file is a directory, we don't need to do anything.
+	if (s.st_mode & S_IFDIR) {
+		ret = 0;
+		goto cleanup;
+	}
+
+	// File exists and isn't a directory, so return an error.
+	ret = -1;
+	goto cleanup;
+
+cleanup:
+	free(path);
+	return ret;
+}
diff --git a/pathnames.h b/pathnames.h
index d6e91a5..f24ba08 100644
--- a/pathnames.h
+++ b/pathnames.h
@@ -31,5 +31,13 @@
  *	@(#)pathnames.h	8.1 (Berkeley) 5/31/93
  */
 
-#define	_PATH_SCOREFILE	"/var/games/rogue.scores"
+#ifndef _PATHNAMES_H
+#define _PATHNAMES_H
+
+#include <stdio.h>
+
 #define _PATH_SCREENDUMP "rogue.screen"
+
+FILE *open_score_file(void);
+
+#endif // _PATHNAMES_H
diff --git a/rogue.h b/rogue.h
index 75d03ef..e3ae604 100644
--- a/rogue.h
+++ b/rogue.h
@@ -542,7 +542,6 @@ int	md_gseed(void);
 void	md_heed_signals(void);
 void	md_ignore_signals(void);
 int	md_link_count(const char *);
-void	md_lock(boolean);
 void	md_shell(const char *);
 void	md_sleep(int);
 void	md_slurp(void);
diff --git a/score.c b/score.c
index 4bcf4e3..e8815ec 100644
--- a/score.c
+++ b/score.c
@@ -32,6 +32,7 @@
  * SUCH DAMAGE.
  */
 
+#include <stdlib.h>
 #include <sys/cdefs.h>
 #ifndef lint
 #if 0
@@ -341,16 +342,12 @@ put_scores(const object *monster, short other)
 	FILE *fp;
 	boolean dopause = score_only;
 
-	md_lock(1);
-
-	setegid(egid);
-	if ((fp = fopen(_PATH_SCOREFILE, "r+")) == NULL &&
-	    (fp = fopen(_PATH_SCOREFILE, "w+")) == NULL) {
-		setegid(gid);
+	fp = open_score_file();
+	if (fp== NULL) {
 		messagef(0, "cannot read/write/create score file");
 		sf_error();
 	}
-	setegid(gid);
+
 	rewind(fp);
 	(void)xxx(1);
 
@@ -418,7 +415,7 @@ put_scores(const object *monster, short other)
 			write_score_entry(&scores[i], i, fp);
 		}
 	}
-	md_lock(0);
+
 	fclose(fp);
 
 	/* Display the scores */
@@ -668,7 +665,6 @@ center(short row, const char *buf)
 static void
 sf_error(void)
 {
-	md_lock(0);
 	messagef(1, "%s", "");		/* gcc objects to just "" */
 	clean_up("sorry, score file is out of order");
 }