From e14a287292c79724d22360b857f0f07740db893b Mon Sep 17 00:00:00 2001
From: Willian Galvani <williangalvani@gmail.com>
Date: Mon, 14 Mar 2022 11:33:32 -0300
Subject: [PATCH] AP_Filesystem: add allow_absolute_paths to open(), implement
 it for posix backend

---
 libraries/AP_Filesystem/AP_Filesystem.cpp         | 4 ++--
 libraries/AP_Filesystem/AP_Filesystem.h           | 2 +-
 libraries/AP_Filesystem/AP_Filesystem_ESP32.h     | 2 +-
 libraries/AP_Filesystem/AP_Filesystem_FATFS.cpp   | 2 +-
 libraries/AP_Filesystem/AP_Filesystem_FATFS.h     | 2 +-
 libraries/AP_Filesystem/AP_Filesystem_Mission.cpp | 2 +-
 libraries/AP_Filesystem/AP_Filesystem_Mission.h   | 2 +-
 libraries/AP_Filesystem/AP_Filesystem_Param.cpp   | 2 +-
 libraries/AP_Filesystem/AP_Filesystem_Param.h     | 2 +-
 libraries/AP_Filesystem/AP_Filesystem_ROMFS.cpp   | 2 +-
 libraries/AP_Filesystem/AP_Filesystem_ROMFS.h     | 2 +-
 libraries/AP_Filesystem/AP_Filesystem_Sys.cpp     | 2 +-
 libraries/AP_Filesystem/AP_Filesystem_Sys.h       | 2 +-
 libraries/AP_Filesystem/AP_Filesystem_backend.h   | 2 +-
 libraries/AP_Filesystem/AP_Filesystem_posix.cpp   | 6 ++++--
 libraries/AP_Filesystem/AP_Filesystem_posix.h     | 2 +-
 16 files changed, 20 insertions(+), 18 deletions(-)

diff --git a/libraries/AP_Filesystem/AP_Filesystem.cpp b/libraries/AP_Filesystem/AP_Filesystem.cpp
index 1719a7b0c5..2d677bef8d 100644
--- a/libraries/AP_Filesystem/AP_Filesystem.cpp
+++ b/libraries/AP_Filesystem/AP_Filesystem.cpp
@@ -106,10 +106,10 @@ const AP_Filesystem::Backend &AP_Filesystem::backend_by_fd(int &fd) const
     return backends[idx];
 }
 
-int AP_Filesystem::open(const char *fname, int flags)
+int AP_Filesystem::open(const char *fname, int flags, bool allow_absolute_paths)
 {
     const Backend &backend = backend_by_path(fname);
-    int fd = backend.fs.open(fname, flags);
+    int fd = backend.fs.open(fname, flags, allow_absolute_paths);
     if (fd < 0) {
         return -1;
     }
diff --git a/libraries/AP_Filesystem/AP_Filesystem.h b/libraries/AP_Filesystem/AP_Filesystem.h
index 972b8e93dd..bbd02e78b5 100644
--- a/libraries/AP_Filesystem/AP_Filesystem.h
+++ b/libraries/AP_Filesystem/AP_Filesystem.h
@@ -80,7 +80,7 @@ public:
     AP_Filesystem() {}
 
     // functions that closely match the equivalent posix calls
-    int open(const char *fname, int flags);
+    int open(const char *fname, int flags, bool allow_absolute_paths = false);
     int close(int fd);
     int32_t read(int fd, void *buf, uint32_t count);
     int32_t write(int fd, const void *buf, uint32_t count);
diff --git a/libraries/AP_Filesystem/AP_Filesystem_ESP32.h b/libraries/AP_Filesystem/AP_Filesystem_ESP32.h
index bdc03fbd33..69877fb7f5 100644
--- a/libraries/AP_Filesystem/AP_Filesystem_ESP32.h
+++ b/libraries/AP_Filesystem/AP_Filesystem_ESP32.h
@@ -21,7 +21,7 @@ class AP_Filesystem_ESP32 : public AP_Filesystem_Backend
 {
 public:
     // functions that closely match the equivalent posix calls
-    int open(const char *fname, int flags) override;
+    int open(const char *fname, int flags, bool allow_absolute_paths = false) override;
     int close(int fd) override;
     int32_t read(int fd, void *buf, uint32_t count) override;
     int32_t write(int fd, const void *buf, uint32_t count) override;
diff --git a/libraries/AP_Filesystem/AP_Filesystem_FATFS.cpp b/libraries/AP_Filesystem/AP_Filesystem_FATFS.cpp
index 887aabfd98..29a45d3aed 100644
--- a/libraries/AP_Filesystem/AP_Filesystem_FATFS.cpp
+++ b/libraries/AP_Filesystem/AP_Filesystem_FATFS.cpp
@@ -279,7 +279,7 @@ static bool remount_file_system(void)
     return true;
 }
 
-int AP_Filesystem_FATFS::open(const char *pathname, int flags)
+int AP_Filesystem_FATFS::open(const char *pathname, int flags, bool allow_absolute_path)
 {
     int fileno;
     int fatfs_modes;
diff --git a/libraries/AP_Filesystem/AP_Filesystem_FATFS.h b/libraries/AP_Filesystem/AP_Filesystem_FATFS.h
index 5193555947..663dffc819 100644
--- a/libraries/AP_Filesystem/AP_Filesystem_FATFS.h
+++ b/libraries/AP_Filesystem/AP_Filesystem_FATFS.h
@@ -20,7 +20,7 @@ class AP_Filesystem_FATFS : public AP_Filesystem_Backend
 {
 public:
     // functions that closely match the equivalent posix calls
-    int open(const char *fname, int flags) override;
+    int open(const char *fname, int flags, bool allow_absolute_paths = false) override;
     int close(int fd) override;
     int32_t read(int fd, void *buf, uint32_t count) override;
     int32_t write(int fd, const void *buf, uint32_t count) override;
diff --git a/libraries/AP_Filesystem/AP_Filesystem_Mission.cpp b/libraries/AP_Filesystem/AP_Filesystem_Mission.cpp
index d4cb9f34de..ab71298b9d 100644
--- a/libraries/AP_Filesystem/AP_Filesystem_Mission.cpp
+++ b/libraries/AP_Filesystem/AP_Filesystem_Mission.cpp
@@ -30,7 +30,7 @@ extern int errno;
 
 #define IDLE_TIMEOUT_MS 30000
 
-int AP_Filesystem_Mission::open(const char *fname, int flags)
+int AP_Filesystem_Mission::open(const char *fname, int flags, bool allow_absolute_paths)
 {
     enum MAV_MISSION_TYPE mtype;
 
diff --git a/libraries/AP_Filesystem/AP_Filesystem_Mission.h b/libraries/AP_Filesystem/AP_Filesystem_Mission.h
index b4ff4f53ca..a4f0f869fd 100644
--- a/libraries/AP_Filesystem/AP_Filesystem_Mission.h
+++ b/libraries/AP_Filesystem/AP_Filesystem_Mission.h
@@ -23,7 +23,7 @@ class AP_Filesystem_Mission : public AP_Filesystem_Backend
 {
 public:
     // functions that closely match the equivalent posix calls
-    int open(const char *fname, int flags) override;
+    int open(const char *fname, int flags, bool allow_absolute_paths = false) override;
     int close(int fd) override;
     int32_t read(int fd, void *buf, uint32_t count) override;
     int32_t lseek(int fd, int32_t offset, int whence) override;
diff --git a/libraries/AP_Filesystem/AP_Filesystem_Param.cpp b/libraries/AP_Filesystem/AP_Filesystem_Param.cpp
index a10e4a6f9a..1bf5c22a11 100644
--- a/libraries/AP_Filesystem/AP_Filesystem_Param.cpp
+++ b/libraries/AP_Filesystem/AP_Filesystem_Param.cpp
@@ -26,7 +26,7 @@
 extern const AP_HAL::HAL& hal;
 extern int errno;
 
-int AP_Filesystem_Param::open(const char *fname, int flags)
+int AP_Filesystem_Param::open(const char *fname, int flags, bool allow_absolute_path)
 {
     if (!check_file_name(fname)) {
         errno = ENOENT;
diff --git a/libraries/AP_Filesystem/AP_Filesystem_Param.h b/libraries/AP_Filesystem/AP_Filesystem_Param.h
index 98e8dc6af1..6f3c30f046 100644
--- a/libraries/AP_Filesystem/AP_Filesystem_Param.h
+++ b/libraries/AP_Filesystem/AP_Filesystem_Param.h
@@ -24,7 +24,7 @@ class AP_Filesystem_Param : public AP_Filesystem_Backend
 {
 public:
     // functions that closely match the equivalent posix calls
-    int open(const char *fname, int flags) override;
+    int open(const char *fname, int flags, bool allow_absolute_paths = false) override;
     int close(int fd) override;
     int32_t read(int fd, void *buf, uint32_t count) override;
     int32_t lseek(int fd, int32_t offset, int whence) override;
diff --git a/libraries/AP_Filesystem/AP_Filesystem_ROMFS.cpp b/libraries/AP_Filesystem/AP_Filesystem_ROMFS.cpp
index 5b23b4e898..d4e3dadb3f 100644
--- a/libraries/AP_Filesystem/AP_Filesystem_ROMFS.cpp
+++ b/libraries/AP_Filesystem/AP_Filesystem_ROMFS.cpp
@@ -23,7 +23,7 @@
 
 #if defined(HAL_HAVE_AP_ROMFS_EMBEDDED_H)
 
-int AP_Filesystem_ROMFS::open(const char *fname, int flags)
+int AP_Filesystem_ROMFS::open(const char *fname, int flags, bool allow_absolute_paths)
 {
     if ((flags & O_ACCMODE) != O_RDONLY) {
         errno = EROFS;
diff --git a/libraries/AP_Filesystem/AP_Filesystem_ROMFS.h b/libraries/AP_Filesystem/AP_Filesystem_ROMFS.h
index fb69e23360..897195915e 100644
--- a/libraries/AP_Filesystem/AP_Filesystem_ROMFS.h
+++ b/libraries/AP_Filesystem/AP_Filesystem_ROMFS.h
@@ -21,7 +21,7 @@ class AP_Filesystem_ROMFS : public AP_Filesystem_Backend
 {
 public:
     // functions that closely match the equivalent posix calls
-    int open(const char *fname, int flags) override;
+    int open(const char *fname, int flags, bool allow_absolute_paths = false) override;
     int close(int fd) override;
     int32_t read(int fd, void *buf, uint32_t count) override;
     int32_t write(int fd, const void *buf, uint32_t count) override;
diff --git a/libraries/AP_Filesystem/AP_Filesystem_Sys.cpp b/libraries/AP_Filesystem/AP_Filesystem_Sys.cpp
index da14a5bfc5..0d0550c8f7 100644
--- a/libraries/AP_Filesystem/AP_Filesystem_Sys.cpp
+++ b/libraries/AP_Filesystem/AP_Filesystem_Sys.cpp
@@ -60,7 +60,7 @@ int8_t AP_Filesystem_Sys::file_in_sysfs(const char *fname) {
     return -1;
 }
 
-int AP_Filesystem_Sys::open(const char *fname, int flags)
+int AP_Filesystem_Sys::open(const char *fname, int flags, bool allow_absolute_paths)
 {
     if ((flags & O_ACCMODE) != O_RDONLY) {
         errno = EROFS;
diff --git a/libraries/AP_Filesystem/AP_Filesystem_Sys.h b/libraries/AP_Filesystem/AP_Filesystem_Sys.h
index 1eef1fac35..e097b74d4a 100644
--- a/libraries/AP_Filesystem/AP_Filesystem_Sys.h
+++ b/libraries/AP_Filesystem/AP_Filesystem_Sys.h
@@ -23,7 +23,7 @@ class AP_Filesystem_Sys : public AP_Filesystem_Backend
 {
 public:
     // functions that closely match the equivalent posix calls
-    int open(const char *fname, int flags) override;
+    int open(const char *fname, int flags, bool allow_absolute_paths = false) override;
     int close(int fd) override;
     int32_t read(int fd, void *buf, uint32_t count) override;
     int32_t lseek(int fd, int32_t offset, int whence) override;
diff --git a/libraries/AP_Filesystem/AP_Filesystem_backend.h b/libraries/AP_Filesystem/AP_Filesystem_backend.h
index a60fad1d17..f359891cf9 100644
--- a/libraries/AP_Filesystem/AP_Filesystem_backend.h
+++ b/libraries/AP_Filesystem/AP_Filesystem_backend.h
@@ -43,7 +43,7 @@ class AP_Filesystem_Backend {
 
 public:
     // functions that closely match the equivalent posix calls
-    virtual int open(const char *fname, int flags) {
+    virtual int open(const char *fname, int flags, bool allow_absolute_paths = false) {
         return -1;
     }
     virtual int close(int fd) { return -1; }
diff --git a/libraries/AP_Filesystem/AP_Filesystem_posix.cpp b/libraries/AP_Filesystem/AP_Filesystem_posix.cpp
index 6454d86d60..f0982159b2 100644
--- a/libraries/AP_Filesystem/AP_Filesystem_posix.cpp
+++ b/libraries/AP_Filesystem/AP_Filesystem_posix.cpp
@@ -49,10 +49,12 @@ static const char *map_filename(const char *fname)
     return fname;
 }
 
-int AP_Filesystem_Posix::open(const char *fname, int flags)
+int AP_Filesystem_Posix::open(const char *fname, int flags, bool allow_absolute_paths)
 {
     FS_CHECK_ALLOWED(-1);
-    fname = map_filename(fname);
+    if (! allow_absolute_paths) {
+        fname = map_filename(fname);
+    }
     // we automatically add O_CLOEXEC as we always want it for ArduPilot FS usage
     return ::open(fname, flags | O_CLOEXEC, 0644);
 }
diff --git a/libraries/AP_Filesystem/AP_Filesystem_posix.h b/libraries/AP_Filesystem/AP_Filesystem_posix.h
index 42fdad3ec6..61d6bfdfd3 100644
--- a/libraries/AP_Filesystem/AP_Filesystem_posix.h
+++ b/libraries/AP_Filesystem/AP_Filesystem_posix.h
@@ -29,7 +29,7 @@ class AP_Filesystem_Posix : public AP_Filesystem_Backend
 {
 public:
     // functions that closely match the equivalent posix calls
-    int open(const char *fname, int flags) override;
+    int open(const char *fname, int flags, bool allow_absolute_paths = false) override;
     int close(int fd) override;
     int32_t read(int fd, void *buf, uint32_t count) override;
     int32_t write(int fd, const void *buf, uint32_t count) override;