--- /dev/null
+/*
+ * Copyright (c) 2015 Dmitry V. Levin <ldv@altlinux.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ * derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "defs.h"
+
+#ifdef HAVE_LINUX_SECCOMP_H
+# include <linux/seccomp.h>
+#endif
+
+#ifndef SECCOMP_SET_MODE_STRICT
+# define SECCOMP_SET_MODE_STRICT 1
+#endif
+#ifndef SECCOMP_SET_MODE_FILTER
+# define SECCOMP_SET_MODE_FILTER 1
+#endif
+#include "xlat/seccomp_ops.h"
+
+#ifndef SECCOMP_FILTER_FLAG_TSYNC
+# define SECCOMP_FILTER_FLAG_TSYNC 1
+#endif
+#include "xlat/seccomp_filter_flags.h"
+
+#ifdef HAVE_LINUX_FILTER_H
+# include <linux/filter.h>
+# include "xlat/bpf_class.h"
+# include "xlat/bpf_miscop.h"
+# include "xlat/bpf_mode.h"
+# include "xlat/bpf_op_alu.h"
+# include "xlat/bpf_op_jmp.h"
+# include "xlat/bpf_rval.h"
+# include "xlat/bpf_size.h"
+# include "xlat/bpf_src.h"
+
+# ifndef SECCOMP_RET_ACTION
+# define SECCOMP_RET_ACTION 0x7fff0000U
+# endif
+# include "xlat/seccomp_ret_action.h"
+#endif
+
+struct bpf_filter {
+ uint16_t code;
+ uint8_t jt;
+ uint8_t jf;
+ uint32_t k;
+};
+
+#ifdef HAVE_LINUX_FILTER_H
+
+static void
+decode_bpf_code(uint16_t code)
+{
+ uint16_t i = code & ~BPF_CLASS(code);
+
+ printxval(bpf_class, BPF_CLASS(code), "BPF_???");
+ switch (BPF_CLASS(code)) {
+ case BPF_LD:
+ case BPF_LDX:
+ tprints(" | ");
+ printxval(bpf_size, BPF_SIZE(code), "BPF_???");
+ tprints(" | ");
+ printxval(bpf_mode, BPF_MODE(code), "BPF_???");
+ break;
+ case BPF_ST:
+ case BPF_STX:
+ if (i)
+ tprintf(" | %#x /* %s */", i, "BPF_???");
+ break;
+ case BPF_ALU:
+ tprints(" | ");
+ printxval(bpf_src, BPF_SRC(code), "BPF_???");
+ tprints(" | ");
+ printxval(bpf_op_alu, BPF_OP(code), "BPF_???");
+ break;
+ case BPF_JMP:
+ tprints(" | ");
+ printxval(bpf_src, BPF_SRC(code), "BPF_???");
+ tprints(" | ");
+ printxval(bpf_op_jmp, BPF_OP(code), "BPF_???");
+ break;
+ case BPF_RET:
+ tprints(" | ");
+ printxval(bpf_rval, BPF_RVAL(code), "BPF_???");
+ i &= ~BPF_RVAL(code);
+ if (i)
+ tprintf(" | %#x /* %s */", i, "BPF_???");
+ break;
+ case BPF_MISC:
+ tprints(" | ");
+ printxval(bpf_miscop, BPF_MISCOP(code), "BPF_???");
+ i &= ~BPF_MISCOP(code);
+ if (i)
+ tprintf(" | %#x /* %s */", i, "BPF_???");
+ break;
+ }
+
+}
+
+static void
+decode_bpf_stmt(const struct bpf_filter *filter)
+{
+#ifdef HAVE_LINUX_FILTER_H
+ tprints("BPF_STMT(");
+ decode_bpf_code(filter->code);
+ tprints(", ");
+ if (BPF_CLASS(filter->code) == BPF_RET) {
+ unsigned int action = SECCOMP_RET_ACTION & filter->k;
+ unsigned int data = filter->k & ~action;
+
+ printxval(seccomp_ret_action, action, "SECCOMP_RET_???");
+ if (data)
+ tprintf(" | %#x)", data);
+ else
+ tprints(")");
+ } else {
+ tprintf("%#x)", filter->k);
+ }
+#else
+ tprintf("BPF_STMT(%#x, %#x)", filter->code, filter->k);
+#endif /* HAVE_LINUX_FILTER_H */
+}
+
+static void
+decode_bpf_jump(const struct bpf_filter *filter)
+{
+#ifdef HAVE_LINUX_FILTER_H
+ tprints("BPF_JUMP(");
+ decode_bpf_code(filter->code);
+ tprintf(", %#x, %#x, %#x)",
+ filter->k, filter->jt, filter->jf);
+#else
+ tprintf("BPF_JUMP(%#x, %#x, %#x, %#x)",
+ filter->code, filter->k, filter->jt, filter->jf);
+#endif /* HAVE_LINUX_FILTER_H */
+}
+
+static void
+decode_filter(const struct bpf_filter *filter)
+{
+ if (filter->jt || filter->jf)
+ decode_bpf_jump(filter);
+ else
+ decode_bpf_stmt(filter);
+}
+
+#endif /* HAVE_LINUX_FILTER_H */
+
+#ifndef BPF_MAXINSNS
+# define BPF_MAXINSNS 4096
+#endif
+
+static void
+decode_fprog(struct tcb *tcp, unsigned short len, unsigned long addr)
+{
+ if (!len || abbrev(tcp)) {
+ tprintf("{len = %u, filter = %#lx}", len, addr);
+ } else {
+ unsigned int i = 0;
+
+ tprints("[");
+ while (i < len && i < BPF_MAXINSNS) {
+ struct bpf_filter filter;
+
+ if (umove(tcp, addr, &filter) < 0)
+ break;
+ if (i)
+ tprints(", ");
+ decode_filter(&filter);
+
+ addr += sizeof(filter);
+ ++i;
+ }
+ if (i < len)
+ tprints("...");
+ tprints("]");
+ }
+}
+
+void
+print_seccomp_filter(struct tcb *tcp, unsigned long addr)
+{
+ if (addr) {
+#if SUPPORTED_PERSONALITIES > 1 && SIZEOF_LONG > 4
+ if (current_wordsize == 4) {
+ struct {
+ unsigned short len;
+ uint32_t filter;
+ } fprog;
+ if (umove(tcp, addr, &fprog) < 0)
+ tprintf("%#lx", addr);
+ else
+ decode_fprog(tcp, fprog.len, fprog.filter);
+ } else {
+#endif
+ struct {
+ unsigned short len;
+ unsigned long filter;
+ } fprog;
+ if (umove(tcp, addr, &fprog) < 0)
+ tprintf("%#lx", addr);
+ else
+ decode_fprog(tcp, fprog.len, fprog.filter);
+#if SUPPORTED_PERSONALITIES > 1 && SIZEOF_LONG > 4
+ }
+#endif
+ } else {
+ tprints("NULL");
+ }
+}
+
+static void
+decode_seccomp_set_mode_strict(unsigned int flags, unsigned long addr)
+{
+ tprintf("%u, ", flags);
+ if (addr)
+ tprintf("%#lx", addr);
+ else
+ tprints("NULL");
+}
+
+int
+sys_seccomp(struct tcb *tcp)
+{
+ if (entering(tcp)) {
+ unsigned int op = tcp->u_arg[0];
+
+ printxval(seccomp_ops, op, "SECCOMP_SET_MODE_???");
+ tprints(", ");
+
+ if (op == SECCOMP_SET_MODE_FILTER) {
+ printflags(seccomp_filter_flags, tcp->u_arg[1],
+ "SECCOMP_FILTER_FLAG_???");
+ tprints(", ");
+ print_seccomp_filter(tcp, tcp->u_arg[2]);
+ } else {
+ decode_seccomp_set_mode_strict(tcp->u_arg[1],
+ tcp->u_arg[2]);
+ }
+ }
+ return 0;
+}
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