Unit test for path sanitation porting

Reference: https://cs.opensource.google/go/go/+/refs/tags/go1.21.4:src/path/path_test.go

.gitignore

@@ -15,6 +15,7 @@ build/mini-gdbstub
 build/softfloat
 build/cache/
 build/map/
+build/path/
 *.o
 *.o.d
 tests/**/*.elf

mk/tests.mk

@@ -6,13 +6,20 @@ MAP_TEST_SRCDIR := tests/map
 MAP_TEST_OUTDIR:= build/map
 MAP_TEST_TARGET := $(MAP_TEST_OUTDIR)/test-map
 
+PATH_TEST_SRCDIR := tests/path
+PATH_TEST_OUTDIR := build/path
+PATH_TEST_TARGET := $(PATH_TEST_OUTDIR)/test-path
+
 CACHE_TEST_OBJS := \
 	test-cache.o
 
 MAP_TEST_OBJS := \
 	test-map.o \
 	mt19937.o
 
+PATH_TEST_OBJS := \
+	test-path.o 
+
 CACHE_TEST_OBJS := $(addprefix $(CACHE_TEST_OUTDIR)/, $(CACHE_TEST_OBJS)) \
 		   $(OUT)/cache.o $(OUT)/mpool.o
 OBJS += $(CACHE_TEST_OBJS)
@@ -23,6 +30,11 @@ MAP_TEST_OBJS := $(addprefix $(MAP_TEST_OUTDIR)/, $(MAP_TEST_OBJS)) \
 OBJS += $(MAP_TEST_OBJS)
 deps += $(MAP_TEST_OBJS:%.o=%.o.d)
 
+PATH_TEST_OBJS := $(addprefix $(PATH_TEST_OUTDIR)/, $(PATH_TEST_OBJS)) \
+		   $(OUT)/utils.o 
+OBJS += $(PATH_TEST_OBJS)
+deps += $(PATH_TEST_OBJS:%.o=%.o.d)
+
 # Check adaptive replacement cache policy is enabled or not, default is LFU
 ifeq ($(ENABLE_ARC), 1)
 CACHE_TEST_ACTIONS := \
@@ -43,8 +55,9 @@ endif
 
 CACHE_TEST_OUT = $(addprefix $(CACHE_TEST_OUTDIR)/, $(CACHE_TEST_ACTIONS:%=%.out))
 MAP_TEST_OUT = $(MAP_TEST_TARGET).out
+PATH_TEST_OUT = $(PATH_TEST_TARGET).out
 
-tests : run-test-cache run-test-map
+tests : run-test-cache run-test-map run-test-path
 
 run-test-cache: $(CACHE_TEST_OUT)
 	$(Q)$(foreach e,$(CACHE_TEST_ACTIONS),\
@@ -66,6 +79,15 @@ run-test-map: $(MAP_TEST_OUT)
 	$(PRINTF) "Failed.\n"; \
 	fi;
 
+run-test-path: $(PATH_TEST_OUT)
+	$(Q)$(PATH_TEST_TARGET)
+	$(VECHO) "Running test-path ... "; \
+	if [ $$? -eq 0 ]; then \
+	$(call notice, [OK]); \
+	else \
+	$(PRINTF) "Failed.\n"; \
+	fi;
+
 $(CACHE_TEST_OUT): $(CACHE_TEST_TARGET)
 	$(Q)$(foreach e,$(CACHE_TEST_ACTIONS),\
 	    $(CACHE_TEST_TARGET) $(CACHE_TEST_SRCDIR)/$(e).in > $(CACHE_TEST_OUTDIR)/$(e).out; \
@@ -91,3 +113,15 @@ $(MAP_TEST_OUTDIR)/%.o: $(MAP_TEST_SRCDIR)/%.c
 	$(VECHO) "  CC\t$@\n"
 	$(Q)mkdir -p $(dir $@)
 	$(Q)$(CC) -o $@ $(CFLAGS) -I./src -c -MMD -MF $@.d $<
+
+$(PATH_TEST_OUT): $(PATH_TEST_TARGET)
+	$(Q)touch $@
+
+$(PATH_TEST_TARGET): $(PATH_TEST_OBJS)
+	$(VECHO) "  CC\t$@\n"
+	$(Q)$(CC) $^ -o $@
+
+$(PATH_TEST_OUTDIR)/%.o: $(PATH_TEST_SRCDIR)/%.c
+	$(VECHO) "  CC\t$@\n"
+	$(Q)mkdir -p $(dir $@)
+	$(Q)$(CC) -o $@ $(CFLAGS) -I./src -c -MMD -MF $@.d $<

src/elf.c

@@ -291,13 +291,13 @@ bool elf_load(elf_t *e, riscv_t *rv, memory_t *mem)
     return true;
 }
 
-bool elf_open(elf_t *e, const char *orig_path)
+bool elf_open(elf_t *e, const char *input)
 {
     /* free previous memory */
     if (e->raw_data)
         release(e);
 
-    char *path = sanitize_path(orig_path);
+    char *path = sanitize_path(input);
 
 #if defined(USE_MMAP)
     int fd = open(path, O_RDONLY);

src/main.c

@@ -10,6 +10,7 @@
 
 #include "elf.h"
 #include "state.h"
+#include "utils.h"
 
 /* enable program trace mode */
 static bool opt_trace = false;

src/utils.c

@@ -23,7 +23,7 @@
 #endif
 #endif
 
-const int MAX_PATH_LEN = 1024;
+#define MAX_PATH_LEN 1024
 
 static void get_time_info(int32_t *tv_sec, int32_t *tv_usec)
 {
@@ -72,9 +72,9 @@ void rv_clock_gettime(struct timespec *tp)
     tp->tv_nsec = tv_usec / 1000; /* Transfer to microseconds */
 }
 
-char *sanitize_path(const char *orig_path)
+char *sanitize_path(const char *input)
 {
-    size_t n = strnlen(orig_path, MAX_PATH_LEN);
+    size_t n = strnlen(input, MAX_PATH_LEN);
 
     char *ret = malloc(MAX_PATH_LEN + 1);
     memset(ret, '\0', MAX_PATH_LEN + 1);
@@ -86,15 +86,15 @@ char *sanitize_path(const char *orig_path)
         return ret;
     }
 
-    int rooted = (orig_path[0] == '/');
+    int rooted = (input[0] == '/');
 
     /*
      * Invariants:
-     *	reading from path; r is index of next byte to process -> path[r]
-     *	writing to buf; w is index of next byte to write -> ret[strlen(ret)]
-     *	dotdot is index in buf where .. must stop, either because
-     *		a) it is the leading slash
-     *      b) it is a leading ../../.. prefix.
+     * reading from path; r is index of next byte to process -> path[r]
+     * writing to buf; w is index of next byte to write -> ret[strlen(ret)]
+     * dotdot is index in buf where .. must stop, either because:
+     *  a) it is the leading slash
+     *  b) it is a leading ../../.. prefix.
      */
     size_t w = 0;
     size_t r = 0;
@@ -107,15 +107,14 @@ char *sanitize_path(const char *orig_path)
     }
 
     while (r < n) {
-        if (orig_path[r] == '/') {
+        if (input[r] == '/') {
             /*  empty path element */
             r++;
-        } else if (orig_path[r] == '.' &&
-                   (r + 1 == n || orig_path[r + 1] == '/')) {
+        } else if (input[r] == '.' && (r + 1 == n || input[r + 1] == '/')) {
             /* . element */
             r++;
-        } else if (orig_path[r] == '.' && orig_path[r + 1] == '.' &&
-                   (r + 2 == n || orig_path[r + 2] == '/')) {
+        } else if (input[r] == '.' && input[r + 1] == '.' &&
+                   (r + 2 == n || input[r + 2] == '/')) {
             /* .. element: remove to last / */
             r += 2;
 
@@ -146,13 +145,11 @@ char *sanitize_path(const char *orig_path)
             }
 
             /* copy element */
-            for (; r < n && orig_path[r] != '/'; r++) {
-                ret[w] = orig_path[r];
+            for (; r < n && input[r] != '/'; r++) {
+                ret[w] = input[r];
                 w++;
             }
         }
-        // printf("w = %ld, r = %ld, dotdot = %ld\nret = %s\n", w, r, dotdot,
-        // ret);
     }
 
     /* Turn empty string into "." */
@@ -161,8 +158,9 @@ char *sanitize_path(const char *orig_path)
         w++;
     }
 
-    for (size_t i = w; i < n; i++) {
-        ret[i] = '\0';
-    }
+    /* starting from w till the end, we should mark it as \0 since that part of
+     * the buffer is not used */
+    memset(ret + w, '\0', sizeof(MAX_PATH_LEN + 1 - w));
+
     return ret;
 }

src/utils.h

@@ -46,4 +46,6 @@ void rv_clock_gettime(struct timespec *tp);
  * Getting Dot-Dot Right,”
  * https://9p.io/sys/doc/lexnames.html
  */
-char *sanitize_path(const char *orig_path);
+char *sanitize_path(const char *input);
+
+void sanitize_path_test();

tests/path/test-path.c

@@ -0,0 +1,75 @@
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include "utils.h"
+
+void compare(char *input, char *expected_output)
+{
+    char *input_sanitized = sanitize_path(input);
+    if (strcmp(input_sanitized, expected_output)) {
+        printf("\n\nInput =\t\t\t%s\nOutput =\t\t%s\nExpected output =\t%s\n",
+               input, input_sanitized, expected_output);
+
+        exit(1);
+    }
+
+    free(input_sanitized);
+}
+
+void sanitize_path_test()
+{
+    /* Already clean */
+    compare("", ".");
+    compare("abc", "abc");
+    compare("abc/def", "abc/def");
+    compare(".", ".");
+    compare("..", "..");
+    compare("../..", "../..");
+    compare("../../abc", "../../abc");
+    compare("/abc", "/abc");
+    compare("/", "/");
+
+    /* Remove trailing slash */
+    compare("abc/", "abc");
+    compare("abc/def/", "abc/def");
+    compare("a/b/c/", "a/b/c");
+    compare("./", ".");
+    compare("../", "..");
+    compare("../../", "../..");
+    compare("/abc/", "/abc");
+
+    /* Remove doubled slash */
+    compare("abc//def//ghi", "abc/def/ghi");
+    compare("//abc", "/abc");
+    compare("///abc", "/abc");
+    compare("//abc//", "/abc");
+    compare("abc//", "abc");
+
+    /* Remove . elements */
+    compare("abc/./def", "abc/def");
+    compare("/./abc/def", "/abc/def");
+    compare("abc/.", "abc");
+
+    /* Remove .. elements */
+    compare("abc/def/ghi/../jkl", "abc/def/jkl");
+    compare("abc/def/../ghi/../jkl", "abc/jkl");
+    compare("abc/def/..", "abc");
+    compare("abc/def/../..", ".");
+    compare("/abc/def/../..", "/");
+    compare("abc/def/../../..", "..");
+    compare("/abc/def/../../..", "/");
+    compare("abc/def/../../../ghi/jkl/../../../mno", "../../mno");
+
+    /* Combinations */
+    compare("abc/./../def", "def");
+    compare("abc//./../def", "def");
+    compare("abc/../../././../def", "../../def");
+}
+
+int main()
+{
+    sanitize_path_test();
+
+    return 0;
+}