Avoid magic string lengths

src/tus_file.c

@@ -83,18 +83,18 @@ tus_file_final_concat_parse(const char *spec)
 	while (spec != NULL) {
 		while (*spec == ' ')
 			spec++;
-		if (strncmp(spec, "http", 4) == 0) {
-			spec += 4;
+		if (TOK(spec, "http")) {
+			AN(spec);
 			if (*spec == 's')
 				spec++;
-			if (strncmp(spec, "://", 3) != 0)
+			if (! TOK(spec, "://"))
 				goto err;
-			spec += 3;
 			p = strchr(spec, '/');
 			if (p == NULL)
 				goto err;
 			spec = p;
 		}
+		AN(spec);
 		if (*spec != '/')
 			goto err;
 		p = strchr(spec, ' ');
@@ -862,7 +862,7 @@ tus_file_load(struct VPFX(tus_server) *srv)
 	dir = fdopendir(dup(basefd));
 	AN(dir);
 	while ((ent = readdir(dir)) != NULL) {
-		if (strncmp(ent->d_name, TUS_FILE_PFX, strlen(TUS_FILE_PFX)))
+		if (STRNCMP(ent->d_name, TUS_FILE_PFX))
 			continue;
 		if (ent->d_type != DT_REG)
 			continue;

src/tus_file.h

@@ -40,6 +40,26 @@
  */
 extern struct VSC_lck *lck_fcore;
 
+/* ============================================================
+ * Util - could move elsewhere
+ */
+
+#define STRNCMP(var, literal)			\
+	strncmp(var, literal, strlen(literal))
+/*
+ * lint:
+ * 820: Boolean test of a parenthesized assignment
+ * 774: Boolean within 'right side of && within if' always
+ *      evaluates to True
+ */
+#define TOK(var, literal)						\
+	(STRNCMP(var, literal) == 0 && ((var) += strlen(literal))	\
+	 /*lint -e(820,774)*/)
+
+/* ============================================================
+ * tus_file
+ */
+
 #define TUS_PATH_MAX		((size_t)PATH_MAX)
 #define TUS_METADATA_MAX	((size_t)2048)	// ballpark of AWS S3 metadata
 

src/tus_request.c

@@ -281,12 +281,11 @@ tus_request(VRT_CTX, struct VPFX(tus_server) *tussrv,
 	}
 
 	if (http_GetHdr(ctx->http_req, hdr_concat, &concat)) {
-		if (strcmp(concat, "partial") == 0) {
+		if (strcmp(concat, "partial") == 0)
 			type = TUS_PARTIAL;
-		} else if (strncmp(concat, "final;", 6) == 0) {
+		else if (TOK(concat, "final;"))
 			type = TUS_FINAL;
-			concat += 6;
-		} else {
+		else {
 			r->s.status = 400;
 			return (0);
 		}