1 files changed, 40 insertions, 26 deletions

diff --git a/src/main.c b/src/main.c
index 12d59c4..b639f6a 100644
--- a/src/main.c
+++ b/src/main.c
@@ -48,6 +48,35 @@ struct parseinfo cached = { 0 };
 char *resultdir;
 int echo = 0, loggedin = 0;
 
+FILE*
+lockfile(const char *path, const char* mode, int locktype)
+{
+	FILE *f;
+
+	if (!(f = fopen(path, mode))) {
+		ERR("Failed to open index file\n");
+		return NULL;
+	}
+	if (flock(fileno(f), locktype)) {
+		fclose(f);
+		ERR("Failed to acquire lock on index file\n");
+		return NULL;
+	}
+	fflush(f); /* discard buffered data */
+	return f;
+}
+
+void
+unlockfile(FILE **f)
+{
+	if (*f) {
+		fflush(*f); /* flush output to file */
+		flock(fileno(*f), LOCK_UN);
+		fclose(*f);
+		*f = NULL;
+	}
+}
+
 int
 save_submission(struct parseinfo *info, char *stldata, int stlsize)
 {
@@ -72,12 +101,11 @@ save_submission(struct parseinfo *info, char *stldata, int stlsize)
 	FCLOSE(f);
 
 	indexpath = aprintf("%s/.index", resultdir);
-	if (!(f = fopen(indexpath, "a+"))) goto fail;
-	flock(fileno(f), LOCK_EX);
+	if (!(f = lockfile(indexpath, "a+", LOCK_EX)))
+		goto exit;
 	fwrite(modeldir, 1, strlen(modeldir), f);
 	fputc('\n', f);
-	flock(fileno(f), LOCK_UN);
-	FCLOSE(f);
+	unlockfile(&f);
 
 exit:
 	FCLOSE(f);
@@ -280,11 +308,8 @@ search_cmd(const char *arg)
 
 	/* open and lock index file access */
 	indexpath = aprintf("%s/.index", resultdir);
-	if (!(f = fopen(indexpath, "r"))) {
-		ERR("Sorry, no files currently available\n");
+	if (!(f = lockfile(indexpath, "r", LOCK_SH)))
 		goto exit;
-	}
-	flock(fileno(f), LOCK_SH);
 
 	/* output lines that have hash as prefix */
 	reslen = matchlen = 0;
@@ -310,8 +335,7 @@ search_cmd(const char *arg)
 		}
 	}
 
-	flock(fileno(f), LOCK_UN);
-	fclose(f);
+	unlockfile(&f);
 
 	if (!reslen) {
 		ERR("Sorry, no files matching that name\n");
@@ -337,7 +361,6 @@ exit:
 	free(filename);
 	free(seldir);
 	free(indexpath);
-	return;
 }
 
 void
@@ -353,14 +376,10 @@ list_cmd(const char *arg)
 	}
 
 	path = aprintf("%s/.index", resultdir);
-	if (!(f = fopen(path, "r"))) {
-		ERR("Failed to get files index\n");
-		free(path);
-		return;
-	}
+	f = lockfile(path, "r", LOCK_SH);
 	free(path);
+	if (!f) return;
 
-	flock(fileno(f), LOCK_SH);
 	while (fgets(buf, sizeof(buf), f)) {
 		if (*buf && buf[strlen(buf)-1] == '\n')
 			buf[strlen(buf)-1] = '\0';
@@ -376,8 +395,8 @@ list_cmd(const char *arg)
 		if (fn) fclose(fn);
 		free(path);
 	}
-	flock(fileno(f), LOCK_UN);
-	fclose(f);
+
+	unlockfile(&f);
 }
 
 void
@@ -409,17 +428,12 @@ auth_cmd(const char *arg)
 
 	if (!existed) {
 		indexpath = aprintf("%s/.index", resultdir);
-		if (!(f = fopen(indexpath, "a+"))) {
-			free(indexpath);
-			ERR("Auth failed!\n");
+		if (!(f = lockfile(indexpath, "a+", LOCK_EX)))
 			return;
-		}
-		flock(fileno(f), LOCK_EX);
 		fputc('.', f);
 		fwrite(hash, 1, strlen(hash), f);
 		fputc('\n', f);
-		flock(fileno(f), LOCK_UN);
-		fclose(f);
+		unlockfile(&f);
 		free(indexpath);
 	}