Implement seccomp decoding
* configure.ac (AC_CHECK_HEADERS): Add linux/filter.h
and linux/seccomp.h.
* defs.h (print_seccomp_filter): New prototype.
* linux/dummy.h (sys_seccomp): Remove.
* linux/syscall.h (sys_seccomp): New prototype.
* prctl.c: Include <linux/seccomp.h>.
(sys_prctl): Decode PR_SET_SECCOMP.
* seccomp.c: New file.
* Makefile.am (strace_SOURCES): Add it.
* xlat/bpf_class.in: New file.
* xlat/bpf_miscop.in: Likewise.
* xlat/bpf_mode.in: Likewise.
* xlat/bpf_op_alu.in: Likewise.
* xlat/bpf_op_jmp.in: Likewise.
* xlat/bpf_rval.in: Likewise.
* xlat/bpf_size.in: Likewise.
* xlat/bpf_src.in: Likewise.
* xlat/seccomp_filter_flags.in: Likewise.
* xlat/seccomp_mode.in: Likewise.
* xlat/seccomp_ops.in: Likewise.
* xlat/seccomp_ret_action.in: Likewise.
diff --git a/Makefile.am b/Makefile.am
index bb2cae2..38cb08b 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -86,6 +86,7 @@
resource.c \
sched.c \
scsi.c \
+ seccomp.c \
signal.c \
sock.c \
socketutils.c \
diff --git a/configure.ac b/configure.ac
index ea55c6e..33af123 100644
--- a/configure.ac
+++ b/configure.ac
@@ -223,11 +223,13 @@
inttypes.h
ioctls.h
linux/falloc.h
+ linux/filter.h
linux/hiddev.h
linux/input.h
linux/mmtimer.h
linux/perf_event.h
linux/ptrace.h
+ linux/seccomp.h
linux/utsname.h
mqueue.h
netinet/sctp.h
diff --git a/defs.h b/defs.h
index 97865da..f0fd471 100644
--- a/defs.h
+++ b/defs.h
@@ -734,6 +734,7 @@
extern void tprint_open_modes(int);
extern const char *sprint_open_modes(int);
extern void print_loff_t(struct tcb *, long);
+extern void print_seccomp_filter(struct tcb *tcp, unsigned long);
extern const struct_ioctlent *ioctl_lookup(const unsigned int);
extern const struct_ioctlent *ioctl_next_match(const struct_ioctlent *);
diff --git a/linux/dummy.h b/linux/dummy.h
index 85dd060..0c2c682 100644
--- a/linux/dummy.h
+++ b/linux/dummy.h
@@ -44,7 +44,6 @@
#define sys_open_by_handle_at printargs
#define sys_sched_getattr printargs
#define sys_sched_setattr printargs
-#define sys_seccomp printargs
#define sys_sysfs printargs
#define sys_vm86 printargs
#define sys_vm86old printargs
diff --git a/linux/syscall.h b/linux/syscall.h
index ba585b3..45d261a 100644
--- a/linux/syscall.h
+++ b/linux/syscall.h
@@ -222,6 +222,7 @@
int sys_sched_setaffinity();
int sys_sched_setparam();
int sys_sched_setscheduler();
+int sys_seccomp();
int sys_select();
int sys_semctl();
int sys_semget();
diff --git a/prctl.c b/prctl.c
index 234d11d..935f399 100644
--- a/prctl.c
+++ b/prctl.c
@@ -25,6 +25,12 @@
return buf;
}
+#ifdef HAVE_LINUX_SECCOMP_H
+# include <linux/seccomp.h>
+#endif
+
+#include "xlat/seccomp_mode.h"
+
int
sys_prctl(struct tcb *tcp)
{
@@ -74,6 +80,28 @@
case PR_GET_KEEPCAPS:
break;
#endif
+
+#ifdef PR_SET_SECCOMP
+ case PR_SET_SECCOMP:
+ tprints(", ");
+ printxval(seccomp_mode, tcp->u_arg[1],
+ "SECCOMP_MODE_???");
+# ifdef SECCOMP_MODE_STRICT
+ if (SECCOMP_MODE_STRICT == tcp->u_arg[1])
+ break;
+# endif
+# ifdef SECCOMP_MODE_FILTER
+ if (SECCOMP_MODE_FILTER == tcp->u_arg[1]) {
+ tprints(", ");
+ print_seccomp_filter(tcp, tcp->u_arg[2]);
+ break;
+ }
+# endif
+ for (i = 2; i < tcp->s_ent->nargs; i++)
+ tprintf(", %#lx", tcp->u_arg[i]);
+ break;
+#endif /* PR_SET_SECCOMP */
+
default:
for (i = 1; i < tcp->s_ent->nargs; i++)
tprintf(", %#lx", tcp->u_arg[i]);
diff --git a/seccomp.c b/seccomp.c
new file mode 100644
index 0000000..8adaac5
--- /dev/null
+++ b/seccomp.c
@@ -0,0 +1,264 @@
+/*
+ * 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;
+}
diff --git a/xlat/bpf_class.in b/xlat/bpf_class.in
new file mode 100644
index 0000000..f8bd3d7
--- /dev/null
+++ b/xlat/bpf_class.in
@@ -0,0 +1,8 @@
+BPF_LD
+BPF_LDX
+BPF_ST
+BPF_STX
+BPF_ALU
+BPF_JMP
+BPF_RET
+BPF_MISC
diff --git a/xlat/bpf_miscop.in b/xlat/bpf_miscop.in
new file mode 100644
index 0000000..c9703b1
--- /dev/null
+++ b/xlat/bpf_miscop.in
@@ -0,0 +1,2 @@
+BPF_TAX
+BPF_TXA
diff --git a/xlat/bpf_mode.in b/xlat/bpf_mode.in
new file mode 100644
index 0000000..10adecd
--- /dev/null
+++ b/xlat/bpf_mode.in
@@ -0,0 +1,7 @@
+BPF_IMM
+BPF_ABS
+BPF_IND
+BPF_MEM
+BPF_LEN
+BPF_MSH
+BPF_XADD
diff --git a/xlat/bpf_op_alu.in b/xlat/bpf_op_alu.in
new file mode 100644
index 0000000..e43aec6
--- /dev/null
+++ b/xlat/bpf_op_alu.in
@@ -0,0 +1,13 @@
+BPF_ADD
+BPF_SUB
+BPF_MUL
+BPF_DIV
+BPF_OR
+BPF_AND
+BPF_LSH
+BPF_RSH
+BPF_NEG
+BPF_MOD
+BPF_XOR
+BPF_MOV
+BPF_ARSH
diff --git a/xlat/bpf_op_jmp.in b/xlat/bpf_op_jmp.in
new file mode 100644
index 0000000..456c0af
--- /dev/null
+++ b/xlat/bpf_op_jmp.in
@@ -0,0 +1,10 @@
+BPF_JA
+BPF_JEQ
+BPF_JGT
+BPF_JGE
+BPF_JSET
+BPF_JNE
+BPF_JSGT
+BPF_JSGE
+BPF_CALL
+BPF_EXIT
diff --git a/xlat/bpf_rval.in b/xlat/bpf_rval.in
new file mode 100644
index 0000000..44e137e
--- /dev/null
+++ b/xlat/bpf_rval.in
@@ -0,0 +1,3 @@
+BPF_K
+BPF_X
+BPF_A
diff --git a/xlat/bpf_size.in b/xlat/bpf_size.in
new file mode 100644
index 0000000..5e0a508
--- /dev/null
+++ b/xlat/bpf_size.in
@@ -0,0 +1,4 @@
+BPF_W
+BPF_H
+BPF_B
+BPF_DW
diff --git a/xlat/bpf_src.in b/xlat/bpf_src.in
new file mode 100644
index 0000000..ede6abb
--- /dev/null
+++ b/xlat/bpf_src.in
@@ -0,0 +1,2 @@
+BPF_K
+BPF_X
diff --git a/xlat/seccomp_filter_flags.in b/xlat/seccomp_filter_flags.in
new file mode 100644
index 0000000..34e6847
--- /dev/null
+++ b/xlat/seccomp_filter_flags.in
@@ -0,0 +1 @@
+SECCOMP_FILTER_FLAG_TSYNC
diff --git a/xlat/seccomp_mode.in b/xlat/seccomp_mode.in
new file mode 100644
index 0000000..34978a5
--- /dev/null
+++ b/xlat/seccomp_mode.in
@@ -0,0 +1,3 @@
+SECCOMP_MODE_DISABLED
+SECCOMP_MODE_STRICT
+SECCOMP_MODE_FILTER
diff --git a/xlat/seccomp_ops.in b/xlat/seccomp_ops.in
new file mode 100644
index 0000000..a28b248
--- /dev/null
+++ b/xlat/seccomp_ops.in
@@ -0,0 +1,2 @@
+SECCOMP_SET_MODE_STRICT
+SECCOMP_SET_MODE_FILTER
diff --git a/xlat/seccomp_ret_action.in b/xlat/seccomp_ret_action.in
new file mode 100644
index 0000000..6212dcb
--- /dev/null
+++ b/xlat/seccomp_ret_action.in
@@ -0,0 +1,5 @@
+SECCOMP_RET_KILL
+SECCOMP_RET_TRAP
+SECCOMP_RET_ERRNO
+SECCOMP_RET_TRACE
+SECCOMP_RET_ALLOW