futility: do traversal of a buffer, not a file

We have been traversing things by passing a file descriptor. Now
the caller should mmap the file first. This will allow the caller
to determine the file type before traversing into it, so we can
check args.

BUG=none
BRANCH=ToT
TEST=make runtests

Signed-off-by: Bill Richardson <wfrichar@chromium.org>
Change-Id: If69799bde0133689dc9fb5111e6ecb5ac61639c7
Reviewed-on: https://chromium-review.googlesource.com/219649
Reviewed-by: Randall Spangler <rspangler@chromium.org>

4 files changed, 93 insertions, 34 deletions

diff --git a/futility/cmd_show.c b/futility/cmd_show.c
index 8f8ebb5c..9fc0a328 100644
--- a/futility/cmd_show.c
+++ b/futility/cmd_show.c
@@ -417,6 +417,8 @@ static int do_show(int argc, char *argv[])
 	int ifd, i;
 	int errorcnt = 0;
 	struct futil_traverse_state_s state;
+	uint8_t *buf;
+	uint32_t buf_len;
 
 	opterr = 0;		/* quiet, you */
 	while ((i = getopt_long(argc, argv, short_opts, long_opts, 0)) != -1) {
@@ -473,15 +475,24 @@ static int do_show(int argc, char *argv[])
 			errorcnt++;
 			fprintf(stderr, "Can't open %s: %s\n",
 				infile, strerror(errno));
-			return 1;
+			continue;
+		}
+
+		if (0 != futil_map_file(ifd, MAP_RO, &buf, &buf_len)) {
+			errorcnt++;
+			goto boo;
 		}
 
 		memset(&state, 0, sizeof(state));
 		state.in_filename = infile ? infile : "<none>";
 		state.op = FUTIL_OP_SHOW;
 
-		errorcnt += futil_traverse(ifd, &state, MAP_RO);
+		errorcnt += futil_traverse(buf, buf_len, &state,
+					   FILE_TYPE_UNKNOWN);
+
+		errorcnt += futil_unmap_file(ifd, MAP_RO, buf, buf_len);
 
+boo:
 		if (close(ifd)) {
 			errorcnt++;
 			fprintf(stderr, "Error when closing %s: %s\n",
diff --git a/futility/cmd_sign.c b/futility/cmd_sign.c
index a983a222..dd28aec4 100644
--- a/futility/cmd_sign.c
+++ b/futility/cmd_sign.c
@@ -330,6 +330,8 @@ static int do_sign(int argc, char *argv[])
 	int errorcnt = 0;
 	struct futil_traverse_state_s state;
 	char *e = 0;
+	uint8_t *buf;
+	uint32_t buf_len;
 
 	opterr = 0;		/* quiet, you */
 	while ((i = getopt_long(argc, argv, short_opts, long_opts, 0)) != -1) {
@@ -465,12 +467,20 @@ static int do_sign(int argc, char *argv[])
 		return 1;
 	}
 
+	if (0 != futil_map_file(fd, MAP_RW, &buf, &buf_len)) {
+		errorcnt++;
+		goto boo;
+	}
+
 	memset(&state, 0, sizeof(state));
 	state.in_filename = outfile ? outfile : "<none>";
 	state.op = FUTIL_OP_SIGN;
 
-	errorcnt += futil_traverse(fd, &state, MAP_RW);
+	errorcnt += futil_traverse(buf, buf_len, &state, FILE_TYPE_UNKNOWN);
+
+	errorcnt += futil_unmap_file(fd, MAP_RO, buf, buf_len);
 
+boo:
 	if (close(fd)) {
 		errorcnt++;
 		fprintf(stderr, "Error when closing %s: %s\n",
diff --git a/futility/traversal.c b/futility/traversal.c
index d7ecf201..b392fa97 100644
--- a/futility/traversal.c
+++ b/futility/traversal.c
@@ -191,7 +191,7 @@ static int invoke_callback(struct futil_traverse_state_s *state,
 	return 0;
 }
 
-static enum futil_file_type what_is_this(uint8_t *buf, uint32_t len)
+enum futil_file_type futil_what_file_type_buf(uint8_t *buf, uint32_t len)
 {
 	VbPublicKey *pubkey = (VbPublicKey *)buf;
 	VbKeyBlockHeader *key_block = (VbKeyBlockHeader *)buf;
@@ -243,16 +243,57 @@ static enum futil_file_type what_is_this(uint8_t *buf, uint32_t len)
 	return FILE_TYPE_UNKNOWN;
 }
 
-static int traverse_buffer(uint8_t *buf, uint32_t len,
-			   struct futil_traverse_state_s *state)
+enum futil_file_type futil_what_file_type(const char *filename)
+{
+	enum futil_file_type type;
+	int ifd;
+	uint8_t *buf;
+	uint32_t buf_len;
+
+	ifd = open(filename, O_RDONLY);
+	if (ifd < 0) {
+		fprintf(stderr, "Can't open %s: %s\n",
+			filename, strerror(errno));
+		exit(1);
+	}
+
+	if (0 != futil_map_file(ifd, MAP_RO, &buf, &buf_len)) {
+		close(ifd);
+		exit(1);
+	}
+
+	type = futil_what_file_type_buf(buf, buf_len);
+
+	if (0 != futil_unmap_file(ifd, MAP_RO, buf, buf_len)) {
+		close(ifd);
+		exit(1);
+	}
+
+	if (close(ifd)) {
+		fprintf(stderr, "Error when closing %s: %s\n",
+			filename, strerror(errno));
+		exit(1);
+	}
+
+	return type;
+}
+
+int futil_traverse(uint8_t *buf, uint32_t len,
+		   struct futil_traverse_state_s *state,
+		   enum futil_file_type type)
 {
 	FmapHeader *fmap;
 	FmapAreaHeader *ah = 0;
 	const struct bios_area_s *area;
-	enum futil_file_type type;
 	int retval = 0;
 
-	type = what_is_this(buf, len);
+	if (state->op < 0 || state->op >= NUM_FUTIL_OPS) {
+		fprintf(stderr, "Invalid op %d\n", state->op);
+		return 1;
+	}
+
+	if (type == FILE_TYPE_UNKNOWN)
+		type = futil_what_file_type_buf(buf, len);
 	state->in_type = type;
 
 	state->errors = retval;
@@ -265,6 +306,9 @@ static int traverse_buffer(uint8_t *buf, uint32_t len,
 	case FILE_TYPE_KEYBLOCK:
 	case FILE_TYPE_FW_PREAMBLE:
 	case FILE_TYPE_GBB:
+	case FILE_TYPE_KERN_PREAMBLE:
+	case FILE_TYPE_RAW_FIRMWARE:
+	case FILE_TYPE_RAW_KERNEL:
 		retval |= invoke_callback(state,
 					  direct_callback[type].component,
 					  direct_callback[type].name,
@@ -305,6 +349,8 @@ static int traverse_buffer(uint8_t *buf, uint32_t len,
 		break;
 
 	default:
+		Debug("%s:%d unhandled type %s\n", __FILE__, __LINE__,
+		      futil_file_type_str[type]);
 		retval = 1;
 	}
 
@@ -312,25 +358,3 @@ static int traverse_buffer(uint8_t *buf, uint32_t len,
 				  0, buf, len);
 	return retval;
 }
-
-int futil_traverse(int ifd, struct futil_traverse_state_s *state,
-		   int writeable)
-{
-	uint8_t *mmap_ptr = 0;
-	uint32_t len;
-	int errorcnt = 0;
-
-	if (state->op < 0 || state->op >= NUM_FUTIL_OPS) {
-		fprintf(stderr, "Invalid op %d\n", state->op);
-		return 1;
-	}
-
-	if (0 != futil_map_file(ifd, writeable, &mmap_ptr, &len))
-		return 1;
-
-	errorcnt |= traverse_buffer(mmap_ptr, len, state);
-
-	errorcnt |= futil_unmap_file(ifd, writeable, mmap_ptr, len);
-
-	return errorcnt;
-}
diff --git a/futility/traversal.h b/futility/traversal.h
index 74c88f5d..531ad6aa 100644
--- a/futility/traversal.h
+++ b/futility/traversal.h
@@ -89,12 +89,26 @@ struct futil_traverse_state_s {
 	int errors;
 };
 
+
+/*
+ * This tries to match the buffer content to one of the known file types.
+ */
+enum futil_file_type futil_what_file_type_buf(uint8_t *buf, uint32_t len);
+
+/*
+ * This opens a file and tries to match it to one of the known file types. It
+ * fails only if it can't open and scan the file. It's not an error if it
+ * returns FILE_TYPE_UKNOWN.
+ */
+enum futil_file_type futil_what_file_type(const char *filename);
+
 /*
- * Traverse the input file using the provided state
- * Return nonzero (but no details) if there were any errors.
+ * Traverse the buffer using the provided state, which should be initialized
+ * before calling. Returns nonzero (but no details) if there were any errors.
  */
-int futil_traverse(int ifd, struct futil_traverse_state_s *state,
-		   int writeable);
+int futil_traverse(uint8_t *buf, uint32_t len,
+		   struct futil_traverse_state_s *state,
+		   enum futil_file_type type_hint);
 
 /* These are invoked by the traversal. They also return nonzero on error. */
 int futil_cb_show_begin(struct futil_traverse_state_s *state);