From 72e3b70bff2d9b3a8ce678b3169fc232f3dfcff3 Mon Sep 17 00:00:00 2001
From: mothcompute <mothcompute@protonmail.com>
Date: Wed, 13 Dec 2023 21:05:35 -0800
Subject: [PATCH] cleanup - needs linux testing

---
 .gitignore |  2 ++
 build      |  2 +-
 main.c     | 40 +++++++++++++++-------------------------
 3 files changed, 18 insertions(+), 26 deletions(-)
 create mode 100644 .gitignore

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..ffec365
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,2 @@
+th.o
+fl
diff --git a/build b/build
index ee7d2a9..b08d0d0 100755
--- a/build
+++ b/build
@@ -1,2 +1,2 @@
 nasm -felf64 th.s
-cc -ggdb3 main.c th.o -o fl -pie #-fno-PIC
+cc -ggdb3 main.c th.o -o fl -pie -fPIC
diff --git a/main.c b/main.c
index 26bf63e..244a648 100644
--- a/main.c
+++ b/main.c
@@ -1,6 +1,5 @@
 #include <stdint.h>
 #include <sys/syscall.h>
-#include <sys/prctl.h>
 #include <sys/stat.h>
 #include <fcntl.h>
 #include <signal.h>
@@ -9,9 +8,12 @@
 #include <string.h>
 #include <unistd.h>
 
+extern void cat(int fd, long sz);
+
+#ifndef __FreeBSD__
+#include <sys/prctl.h>
 #define SYSCT_FBSD 588
 
-extern void cat(int fd, long sz);
 uint8_t sel = SYSCALL_DISPATCH_FILTER_ALLOW;
 
 uint16_t scmap[SYSCT_FBSD] = {
@@ -62,6 +64,7 @@ void systrap(int n, siginfo_t* s, ucontext_t* c) {
 	//for(int i = 0; i < 23; i++) printf("%i: %lX\n", i, c->uc_mcontext.gregs[i]);
 	sel = SYSCALL_DISPATCH_FILTER_BLOCK;
 }
+#endif
 
 typedef struct {
 	uint8_t magic[4];
@@ -85,6 +88,7 @@ typedef struct {
 	uint16_t nameind;
 } __attribute__((packed)) elf;
 
+#ifndef __FreeBSD__
 char** getmaps(int* tsz) {
 	int fd = open("/proc/self/maps", O_RDONLY);
 	char c;
@@ -145,8 +149,10 @@ void stomap(char* s, map* m) {
 	m->name = memcpy(malloc(d), s, d);
 	m->len -= m->start;
 }
+#endif
 
 int main(int argc, char** argv) {
+#ifndef __FreeBSD__
 	struct sigaction a, oa;
 	sigemptyset(&a.sa_mask);
 	a.sa_flags = SA_SIGINFO;
@@ -155,38 +161,22 @@ int main(int argc, char** argv) {
 	int nm;
 	char** smaps = getmaps(&nm);
 
-	// TODO RW to only call stomap if strstr libc - saves memory and cycles
-	map maps[nm-1];
-	for(int i = 0; i < nm-1; i++) {
-		stomap(smaps[i], maps + i);
-		/*
-		printf(
-			"map:\t%s\n"
-			"name:\t%s\n"
-			"start:\t%016lX\n"
-			"length:\t%016lX\n"
-			"access:\t%c%c%c\n"
-			,
-			smaps[i],
-			maps[i].name,
-			maps[i].start,
-			maps[i].len,
-			".R"[(maps[i].rwx >> 2) & 1],
-			".W"[(maps[i].rwx >> 1) & 1],
-			".X"[(maps[i].rwx >> 0) & 1]
-		);
-		*/
-		if(strstr(maps[i].name, "libc") && (maps[i].rwx & 1)) prctl(PR_SET_SYSCALL_USER_DISPATCH, PR_SYS_DISPATCH_ON, maps[i].start, maps[i].len, &sel);
+	for(int i = 0; i < nm-1; i++) if(strstr(smaps[i], "libc")) {
+		map rmap;
+		stomap(smaps[i], &rmap);
+		if(rmap.rwx & 1) prctl(PR_SET_SYSCALL_USER_DISPATCH, PR_SYS_DISPATCH_ON, rmap.start, rmap.len, &sel);
 	}
 	for(int i = 0; i < nm; i++) free(smaps[i]);
 	free(smaps);
-	// END RW
+#endif
 
 	if(argc < 2) return printf("no file provided\n");
 	int fd = open(argv[1], O_RDONLY);
 	struct stat s;
 	fstat(fd, &s);
+#ifndef __FreeBSD__
 	sigaction(SIGSYS, &a, &oa);
 	sel = SYSCALL_DISPATCH_FILTER_BLOCK;
+#endif
 	cat(fd, s.st_size);
 }