From 4affafe91579799efd83f4c8e05c291eeb684c9c Mon Sep 17 00:00:00 2001
From: Christian Hesse <mail@eworm.de>
Date: Wed, 5 Jan 2022 14:35:15 +0100
Subject: use libmagic to detect valid file formats
Writing our own magic bytes detection is prone to errors and an
everlasting catch-up-game. Let's use libmagic to get things right,
this is less code and makes things more reliable.
Building without libmagic is still possible. That will make the code
act like specifying FEH_SKIP_MAGIC=1, effectively passing everything
to imlib2.
---
README.md | 2 +
config.mk | 6 +++
src/imlib.c | 134 +++++++++++++++++++++++-------------------------------------
3 files changed, 59 insertions(+), 83 deletions(-)
diff --git a/README.md b/README.md
index 4401af2..c4cb7ef 100644
--- a/README.md
+++ b/README.md
@@ -22,6 +22,7 @@ Dependencies
* Imlib2
* libcurl (disable with make curl=0)
+ * libmagic (disable with make magic=0)
* libpng
* libX11
* libXinerama (disable with make xinerama=0)
@@ -91,6 +92,7 @@ indicates that the corresponding feature is enabled by default.
| help | 0 | include help text (refers to the manpage otherwise) |
| inotify | 0 | enable inotify, needed for `--auto-reload` |
| stat64 | 0 | Support CIFS shares from 64bit hosts on 32bit machines |
+| magic | 1 | Build against libmagic to filter unsupported file formats |
| mkstemps | 1 | Whether your libc provides `mkstemps()`. If set to 0, feh will be unable to load gif images via libcurl |
| verscmp | 1 | Whether your libc provides `strvercmp()`. If set to 0, feh will use an internal implementation. |
| xinerama | 1 | Support Xinerama/XRandR multiscreen setups |
diff --git a/config.mk b/config.mk
index 2d63f72..910eac7 100644
--- a/config.mk
+++ b/config.mk
@@ -6,6 +6,7 @@ curl ?= 1
debug ?= 0
exif ?= 0
help ?= 0
+magic ?= 1
mkstemps ?= 1
verscmp ?= 1
xinerama ?= 1
@@ -68,6 +69,11 @@ ifeq (${mkstemps},1)
CFLAGS += -DHAVE_MKSTEMPS
endif
+ifeq (${magic},1)
+ CFLAGS += -DHAVE_LIBMAGIC
+ LDLIBS += -lmagic
+endif
+
ifeq (${verscmp},1)
CFLAGS += -DHAVE_STRVERSCMP
endif
diff --git a/src/imlib.c b/src/imlib.c
index 6d709a2..70d459f 100644
--- a/src/imlib.c
+++ b/src/imlib.c
@@ -44,6 +44,10 @@ CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
#include "exif.h"
#endif
+#ifdef HAVE_LIBMAGIC
+#include <magic.h>
+#endif
+
Display *disp = NULL;
Visual *vis = NULL;
Screen *scr = NULL;
@@ -242,98 +246,62 @@ void feh_print_load_error(char *file, winwidget w, Imlib_Load_Error err, enum fe
* avoid calling Imlib2 for files it probably cannot handle. See
* <https://phab.enlightenment.org/T8739> and
* <https://github.com/derf/feh/issues/505>.
- *
- * Note that this drops support for bz2-compressed files, unless
- * FEH_SKIP_MAGIC is set
*/
int feh_is_image(feh_file * file)
{
- unsigned char buf[16];
- FILE *fh = fopen(file->filename, "r");
- if (!fh) {
- return 0;
- }
- // Files smaller than buf will be padded with zeroes
- memset(buf, 0, sizeof(buf));
- if (fread(buf, 1, 16, fh) <= 0) {
- fclose(fh);
- return 0;
- }
- fclose(fh);
+#ifdef HAVE_LIBMAGIC
+ magic_t magic;
+ const char * mime_type;
+ int is_image = 0;
- if (buf[0] == 0xff && buf[1] == 0xd8) {
- // JPEG
- return 1;
- }
- if (!memcmp(buf, "\x89PNG\x0d\x0a\x1a\x0a", 8)) {
- // PNG
- return 1;
- }
- if (buf[0] == 'A' && buf[1] == 'R' && buf[2] == 'G' && buf[3] == 'B') {
- // ARGB
- return 1;
- }
- if (buf[0] == 'B' && buf[1] == 'M') {
- // BMP
- return 1;
- }
- if (!memcmp(buf, "farbfeld", 8)) {
- // farbfeld
- return 1;
- }
- if (buf[0] == 'G' && buf[1] == 'I' && buf[2] == 'F') {
- // GIF
- return 1;
- }
- if (buf[0] == 0x00 && buf[1] == 0x00 && buf[2] <= 0x02 && buf[3] == 0x00) {
- // ICO
- return 1;
- }
- if (!memcmp(buf, "FORM", 4)) {
- // Amiga IFF ILBM
- return 1;
- }
- if (buf[0] == 'P' && buf[1] >= '1' && buf[1] <= '7') {
- // PNM et al.
- return 1;
- }
- if (strstr(file->filename, ".tga")) {
- // TGA
- return 1;
- }
- if (!memcmp(buf, "II\x2a\x00", 4) || !memcmp(buf, "MM\x00\x2a", 4)) {
- // TIFF
- return 1;
- }
- if (!memcmp(buf, "RIFF", 4)) {
- // might be webp
- return 1;
- }
- if (!memcmp(buf + 4, "ftyphei", 7) || !memcmp(buf + 4, "ftypmif1", 8)) {
- // HEIC/HEIF - note that this is only supported in imlib2-heic. Ordinary
- // imlib2 releases do not support heic/heif images as of 2021-01.
- return 1;
- }
- if ((buf[0] == 0xff && buf[1] == 0x0a) || !memcmp(buf, "\x00\x00\x00\x0cJXL \x0d\x0a\x87\x0a", 12)) {
- // JXL - note that this is only supported in imlib2-jxl. Ordinary
- // imlib2 releases do not support JXL images as of 2021-06.
+ if (getenv("FEH_SKIP_MAGIC")) {
return 1;
}
- buf[15] = 0;
- if (strstr((char *)buf, "XPM")) {
- // XPM
- return 1;
+
+ if (!(magic = magic_open(MAGIC_MIME_TYPE | MAGIC_SYMLINK))) {
+ weprintf("unable to initialize magic library\n");
+ return 0;
}
- if (strstr(file->filename, ".bz2") || strstr(file->filename, ".gz")) {
- // Imlib2 supports compressed images. It relies on the filename to
- // determine the appropriate loader and does not use magic bytes here.
- return 1;
+
+ if (magic_load(magic, NULL) != 0) {
+ weprintf("cannot load magic database: %s\n", magic_error(magic));
+ magic_close(magic);
+ return 0;
}
- // moved to the end as this variable won't be set in most cases
- if (getenv("FEH_SKIP_MAGIC")) {
- return 1;
+
+ mime_type = magic_file(magic, file->filename);
+
+ if (mime_type) {
+ D(("file %s has mime type: %s\n", file->filename, mime_type));
+
+ if (strncmp(mime_type, "image/", 6) == 0) {
+ is_image = 1;
+ }
+
+ /* imlib2 supports loading compressed images, let's have a look inside */
+ if (strcmp(mime_type, "application/gzip") == 0 ||
+ strcmp(mime_type, "application/x-bzip2") == 0 ||
+ strcmp(mime_type, "application/x-xz") == 0) {
+ magic_setflags(magic, magic_getflags(magic) | MAGIC_COMPRESS);
+ mime_type = magic_file(magic, file->filename);
+
+ if (mime_type) {
+ D(("uncompressed file %s has mime type: %s\n", file->filename, mime_type));
+
+ if (strncmp(mime_type, "image/", 6) == 0) {
+ is_image = 1;
+ }
+ }
+ }
}
- return 0;
+
+ magic_close(magic);
+
+ return is_image;
+#else
+ (void)file;
+ return 1;
+#endif
}
int feh_load_image(Imlib_Image * im, feh_file * file)
--
cgit v1.2.3
From facb67f8438aa8ef18ffacdccfd0a2d1c2730e5c Mon Sep 17 00:00:00 2001
From: Christian Hesse <mail@eworm.de>
Date: Wed, 12 Jan 2022 09:53:15 +0100
Subject: global initialization for libmagic
Add a global `magic_t magic` and initialize it just once.
Also `feh_is_image()` now calls itself to check compressed files, saving
some duplicate code.
---
src/feh.h | 4 +++
src/imlib.c | 94 +++++++++++++++++++++++++++++++++++--------------------------
src/main.c | 8 ++++++
3 files changed, 66 insertions(+), 40 deletions(-)
diff --git a/src/feh.h b/src/feh.h
index 007c7c5..9afe238 100644
--- a/src/feh.h
+++ b/src/feh.h
@@ -145,6 +145,10 @@ void init_slideshow_mode(void);
void init_list_mode(void);
void init_loadables_mode(void);
void init_unloadables_mode(void);
+#ifdef HAVE_LIBMAGIC
+void uninit_magic(void);
+void init_magic(void);
+#endif
void feh_clean_exit(void);
int feh_should_ignore_image(Imlib_Image * im);
int feh_load_image(Imlib_Image * im, feh_file * file);
diff --git a/src/imlib.c b/src/imlib.c
index 70d459f..0accbdc 100644
--- a/src/imlib.c
+++ b/src/imlib.c
@@ -46,6 +46,8 @@ CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
#ifdef HAVE_LIBMAGIC
#include <magic.h>
+
+magic_t magic = NULL;
#endif
Display *disp = NULL;
@@ -239,6 +241,33 @@ void feh_print_load_error(char *file, winwidget w, Imlib_Load_Error err, enum fe
}
}
+#ifdef HAVE_LIBMAGIC
+void uninit_magic(void)
+{
+ if (!magic) {
+ return;
+ }
+
+ magic_close(magic);
+ magic = NULL;
+}
+void init_magic(void)
+{
+ if (getenv("FEH_SKIP_MAGIC")) {
+ return;
+ }
+
+ if (!(magic = magic_open(MAGIC_NONE))) {
+ weprintf("unable to initialize magic library\n");
+ return;
+ }
+
+ if (magic_load(magic, NULL) != 0) {
+ weprintf("cannot load magic database: %s\n", magic_error(magic));
+ uninit_magic();
+ }
+}
+
/*
* This is a workaround for an Imlib2 regression, causing unloadable image
* detection to be excessively slow (and, thus, causing feh to hang for a while
@@ -247,62 +276,47 @@ void feh_print_load_error(char *file, winwidget w, Imlib_Load_Error err, enum fe
* <https://phab.enlightenment.org/T8739> and
* <https://github.com/derf/feh/issues/505>.
*/
-int feh_is_image(feh_file * file)
+int feh_is_image(feh_file * file, int magic_flags)
{
-#ifdef HAVE_LIBMAGIC
- magic_t magic;
- const char * mime_type;
- int is_image = 0;
+ const char * mime_type = NULL;
- if (getenv("FEH_SKIP_MAGIC")) {
+ if (!magic) {
return 1;
}
- if (!(magic = magic_open(MAGIC_MIME_TYPE | MAGIC_SYMLINK))) {
- weprintf("unable to initialize magic library\n");
- return 0;
- }
+ magic_setflags(magic, MAGIC_MIME_TYPE | MAGIC_SYMLINK | magic_flags);
+ mime_type = magic_file(magic, file->filename);
- if (magic_load(magic, NULL) != 0) {
- weprintf("cannot load magic database: %s\n", magic_error(magic));
- magic_close(magic);
+ if (!mime_type) {
return 0;
}
- mime_type = magic_file(magic, file->filename);
-
- if (mime_type) {
- D(("file %s has mime type: %s\n", file->filename, mime_type));
-
- if (strncmp(mime_type, "image/", 6) == 0) {
- is_image = 1;
- }
-
- /* imlib2 supports loading compressed images, let's have a look inside */
- if (strcmp(mime_type, "application/gzip") == 0 ||
- strcmp(mime_type, "application/x-bzip2") == 0 ||
- strcmp(mime_type, "application/x-xz") == 0) {
- magic_setflags(magic, magic_getflags(magic) | MAGIC_COMPRESS);
- mime_type = magic_file(magic, file->filename);
+ D(("file %s has mime type: %s\n", file->filename, mime_type));
- if (mime_type) {
- D(("uncompressed file %s has mime type: %s\n", file->filename, mime_type));
+ if (strncmp(mime_type, "image/", 6) == 0) {
+ return 1;
+ }
- if (strncmp(mime_type, "image/", 6) == 0) {
- is_image = 1;
- }
- }
- }
+ /* no infinite loop on compressed content, please */
+ if (magic_flags) {
+ return 0;
}
- magic_close(magic);
+ /* imlib2 supports loading compressed images, let's have a look inside */
+ if (strcmp(mime_type, "application/gzip") == 0 ||
+ strcmp(mime_type, "application/x-bzip2") == 0 ||
+ strcmp(mime_type, "application/x-xz") == 0) {
+ return feh_is_image(file, MAGIC_COMPRESS);
+ }
- return is_image;
+ return 0;
+}
#else
- (void)file;
+int feh_is_image(__attribute__((unused)) feh_file * file, __attribute__((unused)) int magic_flags)
+{
return 1;
-#endif
}
+#endif
int feh_load_image(Imlib_Image * im, feh_file * file)
{
@@ -326,7 +340,7 @@ int feh_load_image(Imlib_Image * im, feh_file * file)
}
}
else {
- if (feh_is_image(file)) {
+ if (feh_is_image(file, 0)) {
*im = imlib_load_image_with_error_return(file->filename, &err);
} else {
feh_err = LOAD_ERROR_MAGICBYTES;
diff --git a/src/main.c b/src/main.c
index 3d124fd..34b667a 100644
--- a/src/main.c
+++ b/src/main.c
@@ -69,6 +69,10 @@ int main(int argc, char **argv)
#endif
}
+#ifdef HAVE_LIBMAGIC
+ init_magic();
+#endif
+
feh_event_init();
if (opt.index)
@@ -262,6 +266,10 @@ void feh_clean_exit(void)
if(disp)
XCloseDisplay(disp);
+#ifdef HAVE_LIBMAGIC
+ uninit_magic();
+#endif
+
/*
* Only restore the old terminal settings if
* - we changed them in the first place
--
cgit v1.2.3
From 26cd770c8732a4467e57cf3e7a5d4c2518836275 Mon Sep 17 00:00:00 2001
From: Daniel Friesel <derf@finalrewind.org>
Date: Thu, 10 Feb 2022 21:41:35 +0100
Subject: Run init_magic before init_parse_options
init_parse_options calls feh_prepare_filelist, which in turn calls
feh_file_info_preload if opt.preload is set. This function will load all
images in the filelist to determine their attributes, so we need to initialize
libmagic before calling init_parse_options.
---
src/main.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/src/main.c b/src/main.c
index 34b667a..85e0504 100644
--- a/src/main.c
+++ b/src/main.c
@@ -49,6 +49,11 @@ int main(int argc, char **argv)
srandom(getpid() * time(NULL) % ((unsigned int) -1));
setup_signal_handlers();
+
+#ifdef HAVE_LIBMAGIC
+ init_magic();
+#endif
+
init_parse_options(argc, argv);
init_imlib_fonts();
@@ -69,10 +74,6 @@ int main(int argc, char **argv)
#endif
}
-#ifdef HAVE_LIBMAGIC
- init_magic();
-#endif
-
feh_event_init();
if (opt.index)
--
cgit v1.2.3