Initial implementation of io.fd plugin ##io (#17158)

Useful for `self://` and r2frida when injecting the lib inside a target process

Co-authored-by: pancake <pancake@nopcode.org>

libr/include/r_io.h

@@ -506,6 +506,7 @@ extern RIOPlugin r_io_plugin_ar;
 extern RIOPlugin r_io_plugin_rbuf;
 extern RIOPlugin r_io_plugin_winedbg;
 extern RIOPlugin r_io_plugin_gprobe;
+extern RIOPlugin r_io_plugin_fd;
 
 #if __cplusplus
 }

libr/io/meson.build

@@ -9,6 +9,7 @@ r_io_sources = [
   'undo.c',
   'p_cache.c',
   'p/io_ar.c',
+  'p/io_fd.c',
   'p/io_bfdbg.c',
   'p/io_bochs.c',
   'p/io_debug.c',

libr/io/p/fd.mk

@@ -0,0 +1,16 @@
+OBJ_FD=io_fd.o
+
+STATIC_OBJ+=${OBJ_FD}
+TARGET_FD=io_fd.${EXT_SO}
+ALL_TARGETS+=${TARGET_FD}
+
+ifeq (${WITHPIC},0)
+LINKFLAGS+=../../util/libr_util.a
+LINKFLAGS+=../../io/libr_io.a
+else
+LINKFLAGS+=-L../../util -lr_util
+LINKFLAGS+=-L.. -lr_io
+endif
+
+${TARGET_FD}: ${OBJ_FD}
+	${CC_LIB} $(call libname,io_fd) ${CFLAGS} -o ${TARGET_FD} ${OBJ_FD} ${LINKFLAGS}

libr/io/p/io_fd.c

@@ -0,0 +1,112 @@
+/* radare - LGPL - Copyright 2020 - pancake */
+
+#include "r_io.h"
+#include "r_lib.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <r_cons.h>
+#include <sys/types.h>
+
+#if __WINDOWS__
+#define FDURI "handle://"
+#else
+#define FDURI "fd://"
+#endif
+
+typedef struct {
+	int fd;
+} RIOFdata;
+
+static int __write(RIO *io, RIODesc *desc, const ut8 *buf, int count) {
+	RIOFdata *fdd = (RIOFdata*)desc->data;
+	if (fdd) {
+		return write (fdd->fd, buf, count);
+	}
+	return -1;
+}
+
+static bool __resize(RIO *io, RIODesc *desc, ut64 count) {
+	RIOFdata *fdd = (RIOFdata*)desc->data;
+	if (fdd) {
+		return ftruncate (fdd->fd, count) == 0;
+	}
+	return false;
+}
+
+static int __read(RIO *io, RIODesc *desc, ut8 *buf, int count) {
+	RIOFdata *fdd = (RIOFdata*)desc->data;
+	if (fdd) {
+		r_cons_break_push (NULL, NULL);
+		int res = read (fdd->fd, buf, count);
+		r_cons_break_pop ();
+		return res;
+	}
+	return -1;
+}
+
+static int __close(RIODesc *desc) {
+	R_FREE (desc->data);
+	return 0;
+}
+
+static ut64 __lseek(RIO* io, RIODesc *desc, ut64 offset, int whence) {
+	RIOFdata *fdd = (RIOFdata*)desc->data;
+	if (fdd) {
+		return lseek (fdd->fd, offset, whence);
+	}
+	return 0;
+}
+
+static bool __check(RIO *io, const char *pathname, bool many) {
+	return !strncmp (pathname, FDURI, strlen (FDURI));
+}
+
+static RIODesc *__open(RIO *io, const char *pathname, int rw, int mode) {
+	if (r_sandbox_enable (false)) {
+		eprintf ("Do not permit " FDURI " in sandbox mode.\n");
+		return NULL;
+	}
+	if (!__check (io, pathname, 0)) {
+		return NULL;
+	}
+	RIOFdata *fdd = R_NEW0 (RIOFdata);
+	if (fdd) {
+		fdd->fd = r_num_math (NULL, pathname + strlen (FDURI));
+#if __WINDOWS__
+		fdd->fd = _open_osfhandle (fdd->fd, 0);
+#endif
+		if (fdd->fd < 0) {
+			free (fdd);
+			eprintf ("Invalid filedescriptor.\n");
+			return NULL;
+		}
+	}
+	return r_io_desc_new (io, &r_io_plugin_fd, pathname, R_PERM_RW | rw, mode, fdd);
+}
+
+RIOPlugin r_io_plugin_fd = {
+#if __WINDOWS__
+	.name = "handle",
+	.desc = "Local process file handle IO",
+#else
+	.name = "fd",
+	.desc = "Local process filedescriptor IO",
+#endif
+	.uris = FDURI,
+	.license = "MIT",
+	.open = __open,
+	.close = __close,
+	.read = __read,
+	.check = __check,
+	.lseek = __lseek,
+	.write = __write,
+	.resize = __resize,
+};
+
+#ifndef R2_PLUGIN_INCORE
+R_API RLibStruct radare_plugin = {
+	.type = R_LIB_TYPE_IO,
+	.data = &r_io_plugin_fd,
+	.version = R2_VERSION
+};
+#endif

libr/meson.build

@@ -264,6 +264,7 @@ fs_plugins = [
 
 io_plugins = [
   'ar',
+  'fd',
   'bfdbg',
   'bochs',
   'debug',

plugins.def.cfg

@@ -260,6 +260,7 @@ io.winedbg
 io.zip
 io.r2k
 io.ar
+io.fd
 io.rbuf
 lang.spp
 lang.vala