From 72b93c5761b5e42c5742e192f46bac1696c36f4c Mon Sep 17 00:00:00 2001
From: netblue30 <netblue30@yahoo.com>
Date: Wed, 2 Nov 2016 07:49:01 -0400
Subject: major cleanup

---
 src/fseccomp/seccomp_print.c | 116 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 116 insertions(+)
 create mode 100644 src/fseccomp/seccomp_print.c

(limited to 'src/fseccomp/seccomp_print.c')

diff --git a/src/fseccomp/seccomp_print.c b/src/fseccomp/seccomp_print.c
new file mode 100644
index 000000000..7dc983b12
--- /dev/null
+++ b/src/fseccomp/seccomp_print.c
@@ -0,0 +1,116 @@
+/*
+ * Copyright (C) 2014-2016 Firejail Authors
+ *
+ * This file is part of firejail project
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+#include "fseccomp.h"
+#include "../include/seccomp.h"
+#include <sys/syscall.h>
+
+static struct sock_filter *filter = NULL;
+static int filter_cnt = 0;
+
+static void load_seccomp(const char *fname) {
+	assert(fname);
+
+	// check file
+	struct stat s;
+	if (stat(fname, &s) == -1) {
+		fprintf(stderr, "Error fseccomp: cannot read protocol filter file\n");
+		exit(1);
+	}
+	int size = s.st_size;
+	unsigned short entries = (unsigned short) size / (unsigned short) sizeof(struct sock_filter);
+	filter_cnt = entries;
+//printf("size %d, entries %d\n", s.st_size, entries);
+
+	filter = malloc(sizeof(struct sock_filter) * entries);
+	if (!filter)
+		errExit("malloc");
+		
+	// read filter
+	memset(filter, 0, sizeof(struct sock_filter) * entries);
+	int src = open(fname, O_RDONLY);
+	int rd = 0;
+	while (rd < size) {
+		int rv = read(src, (unsigned char *) filter + rd, size - rd);
+		if (rv == -1) {
+			fprintf(stderr, "Error fseccomp: cannot read %s file\n", fname);
+			exit(1);
+		}
+		rd += rv;
+	}
+	close(src);
+}
+
+// debug filter
+void filter_print(const char *fname) {
+	assert(fname);
+	load_seccomp(fname);
+	
+	// start filter
+	struct sock_filter start[] = {
+		VALIDATE_ARCHITECTURE,
+		EXAMINE_SYSCALL
+	};
+
+	// print sizes
+	printf("SECCOMP Filter:\n");
+
+	// test the start of the filter
+	if (memcmp(&start[0], filter, sizeof(start)) == 0) {
+		printf("  VALIDATE_ARCHITECTURE\n");
+		printf("  EXAMINE_SYSCAL\n");
+	}
+	else {
+		printf("Invalid seccomp filter %s\n", fname);
+		return;
+	}
+	
+	// loop trough blacklists
+	int i = 4;
+	while (i < filter_cnt) {
+		// minimal parsing!
+		unsigned char *ptr = (unsigned char *) &filter[i];
+		int *nr = (int *) (ptr + 4);
+		if (*ptr	== 0x15 && *(ptr +14) == 0xff && *(ptr + 15) == 0x7f ) {
+			printf("  WHITELIST %d %s\n", *nr, syscall_find_nr(*nr));
+			i += 2;
+		}
+		else if (*ptr	== 0x15 && *(ptr +14) == 0 && *(ptr + 15) == 0) {
+			printf("  BLACKLIST %d %s\n", *nr, syscall_find_nr(*nr));
+			i += 2;
+		}
+		else if (*ptr	== 0x15 && *(ptr +14) == 0x5 && *(ptr + 15) == 0) {
+			int err = *(ptr + 13) << 8 | *(ptr + 12);
+			printf("  ERRNO %d %s %d %s\n", *nr, syscall_find_nr(*nr), err, errno_find_nr(err));
+			i += 2;
+		}
+		else if (*ptr == 0x06 && *(ptr +6) == 0 && *(ptr + 7) == 0 ) {
+			printf("  KILL_PROCESS\n");
+			i++;
+		}
+		else if (*ptr == 0x06 && *(ptr +6) == 0xff && *(ptr + 7) == 0x7f ) {
+			printf("  RETURN_ALLOW\n");
+			i++;
+		}
+		else {
+			printf("  UNKNOWN ENTRY!!!\n");
+			i++;
+		}
+	}
+}
-- 
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