Cleanup: libsqfs: sqfs_dir_reader_find_by_path

Split out several repated patterns into helper functions and move the
rest of the code back into dir_reader.c

Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>

6 files changed, 75 insertions, 91 deletions

diff --git a/lib/compat/Makemodule.am b/lib/compat/Makemodule.am
index 0426075..06fc95e 100644
--- a/lib/compat/Makemodule.am
+++ b/lib/compat/Makemodule.am
@@ -8,5 +8,6 @@ libcompat_a_SOURCES += lib/compat/w32_stdio.c
 libcompat_a_SOURCES += lib/compat/fnmatch.c
 libcompat_a_SOURCES += lib/compat/getopt.c
 libcompat_a_SOURCES += lib/compat/getopt_long.c
+libcompat_a_SOURCES += lib/compat/strchrnul.c
 
 noinst_LIBRARIES += libcompat.a
diff --git a/lib/compat/strchrnul.c b/lib/compat/strchrnul.c
new file mode 100644
index 0000000..681b287
--- /dev/null
+++ b/lib/compat/strchrnul.c
@@ -0,0 +1,12 @@
+#include "config.h"
+#include "compat.h"
+
+#ifndef HAVE_STRCHRNUL
+char *strchrnul(const char *s, int c)
+{
+	while (*s && *((unsigned char *)s) != c)
+		++s;
+
+	return (char *)s;
+}
+#endif
diff --git a/lib/sqfs/Makemodule.am b/lib/sqfs/Makemodule.am
index f7292b1..aaf63d8 100644
--- a/lib/sqfs/Makemodule.am
+++ b/lib/sqfs/Makemodule.am
@@ -19,7 +19,6 @@ libsquashfs_la_SOURCES += lib/sqfs/dir_writer.c lib/sqfs/xattr/xattr_reader.c
 libsquashfs_la_SOURCES += lib/sqfs/read_table.c lib/sqfs/comp/compressor.c
 libsquashfs_la_SOURCES += lib/sqfs/comp/internal.h
 libsquashfs_la_SOURCES += lib/sqfs/dir_reader/dir_reader.c
-libsquashfs_la_SOURCES += lib/sqfs/dir_reader/find_by_path.c
 libsquashfs_la_SOURCES += lib/sqfs/dir_reader/read_tree.c
 libsquashfs_la_SOURCES += lib/sqfs/dir_reader/internal.h
 libsquashfs_la_SOURCES += lib/sqfs/inode.c lib/sqfs/xattr/xattr_writer.c
diff --git a/lib/sqfs/dir_reader/dir_reader.c b/lib/sqfs/dir_reader/dir_reader.c
index d09e901..4ac9829 100644
--- a/lib/sqfs/dir_reader/dir_reader.c
+++ b/lib/sqfs/dir_reader/dir_reader.c
@@ -7,6 +7,17 @@
 #define SQFS_BUILDING_DLL
 #include "internal.h"
 
+static int inode_copy(const sqfs_inode_generic_t *inode,
+		      sqfs_inode_generic_t **out)
+{
+	*out = alloc_flex(sizeof(*inode), 1, inode->payload_bytes_used);
+	if (*out == NULL)
+		return SQFS_ERROR_ALLOC;
+
+	memcpy(*out, inode, sizeof(*inode) + inode->payload_bytes_used);
+	return 0;
+}
+
 static int dcache_key_compare(const void *ctx, const void *l, const void *r)
 {
 	sqfs_u32 lhs = *((const sqfs_u32 *)l), rhs = *((const sqfs_u32 *)r);
@@ -310,3 +321,53 @@ int sqfs_dir_reader_get_root_inode(sqfs_dir_reader_t *rd,
 
 	return dcache_add(rd, *inode, rd->super->root_inode_ref);
 }
+
+int sqfs_dir_reader_find_by_path(sqfs_dir_reader_t *rd,
+				 const sqfs_inode_generic_t *start,
+				 const char *path, sqfs_inode_generic_t **out)
+{
+	sqfs_inode_generic_t *inode;
+	const char *ptr;
+	int ret = 0;
+	char *name;
+
+	if (start == NULL) {
+		ret = sqfs_dir_reader_get_root_inode(rd, &inode);
+	} else {
+		ret = inode_copy(start, &inode);
+	}
+
+	if (ret)
+		return ret;
+
+	for (; *path != '\0'; path = ptr) {
+		if (*path == '/') {
+			for (ptr = path; *ptr == '/'; ++ptr)
+				;
+			continue;
+		}
+
+		ret = sqfs_dir_reader_open_dir(rd, inode, 0);
+		free(inode);
+		if (ret)
+			return ret;
+
+		ptr = strchrnul(path, '/');
+
+		name = strndup(path, ptr - path);
+		if (name == NULL)
+			return SQFS_ERROR_ALLOC;
+
+		ret = sqfs_dir_reader_find(rd, name);
+		free(name);
+		if (ret)
+			return ret;
+
+		ret = sqfs_dir_reader_get_inode(rd, &inode);
+		if (ret)
+			return ret;
+	}
+
+	*out = inode;
+	return 0;
+}
diff --git a/lib/sqfs/dir_reader/find_by_path.c b/lib/sqfs/dir_reader/find_by_path.c
deleted file mode 100644
index 0cd800f..0000000
--- a/lib/sqfs/dir_reader/find_by_path.c
+++ /dev/null
@@ -1,82 +0,0 @@
-/* SPDX-License-Identifier: LGPL-3.0-or-later */
-/*
- * find_by_path.c
- *
- * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
- */
-#define SQFS_BUILDING_DLL
-#include "internal.h"
-
-int sqfs_dir_reader_find_by_path(sqfs_dir_reader_t *rd,
-				 const sqfs_inode_generic_t *start,
-				 const char *path, sqfs_inode_generic_t **out)
-{
-	sqfs_inode_generic_t *inode;
-	sqfs_dir_entry_t *ent;
-	const char *ptr;
-	int ret = 0;
-
-	if (start == NULL) {
-		ret = sqfs_dir_reader_get_root_inode(rd, &inode);
-	} else {
-		inode = alloc_flex(sizeof(*inode), 1,
-				   start->payload_bytes_used);
-		if (inode == NULL) {
-			ret = SQFS_ERROR_ALLOC;
-		} else {
-			memcpy(inode, start,
-			       sizeof(*start) + start->payload_bytes_used);
-		}
-	}
-
-	if (ret)
-		return ret;
-
-	while (*path != '\0') {
-		if (*path == '/') {
-			while (*path == '/')
-				++path;
-			continue;
-		}
-
-		ret = sqfs_dir_reader_open_dir(rd, inode, 0);
-		free(inode);
-		if (ret)
-			return ret;
-
-		ptr = strchr(path, '/');
-		if (ptr == NULL) {
-
-			if (ptr == NULL) {
-				for (ptr = path; *ptr != '\0'; ++ptr)
-					;
-			}
-		}
-
-		do {
-			ret = sqfs_dir_reader_read(rd, &ent);
-			if (ret < 0)
-				return ret;
-
-			if (ret == 0) {
-				ret = strncmp((const char *)ent->name,
-					      path, ptr - path);
-				if (ret == 0)
-					ret = ent->name[ptr - path];
-				free(ent);
-			}
-		} while (ret < 0);
-
-		if (ret > 0)
-			return SQFS_ERROR_NO_ENTRY;
-
-		ret = sqfs_dir_reader_get_inode(rd, &inode);
-		if (ret)
-			return ret;
-
-		path = ptr;
-	}
-
-	*out = inode;
-	return 0;
-}
diff --git a/lib/sqfs/dir_reader/read_tree.c b/lib/sqfs/dir_reader/read_tree.c
index 7fa944a..91cc2c0 100644
--- a/lib/sqfs/dir_reader/read_tree.c
+++ b/lib/sqfs/dir_reader/read_tree.c
@@ -218,14 +218,7 @@ int sqfs_dir_reader_get_full_hierarchy(sqfs_dir_reader_t *rd,
 		if (ret)
 			goto fail;
 
-		ptr = strchr(path, '/');
-		if (ptr == NULL) {
-
-			if (ptr == NULL) {
-				for (ptr = path; *ptr != '\0'; ++ptr)
-					;
-			}
-		}
+		ptr = strchrnul(path, '/');
 
 		for (;;) {
 			ret = sqfs_dir_reader_read(rd, &ent);