* .gitignore: Add luajit_lib.h.
* Makefile.am: Build with LuaJIT if configured so.
(strace_SOURCES): Add defs_shared.h, ffi.h.
(luajit_lib.h): Auto-generate from luajit_lib.lua.
* NEWS: New entry.
* basic_filters.c: (syscall_classes): Make global and terminate with a
null entry.
(lookup_class): Use global syscall_classes.
* configure.ac: Add new --with-luajit configure option.
* defs.h (struct inject_opts): Move inject values to...
(struct inject_values): ...new struct.
(TCB_AD_HOC_INJECT, TCB_HOOK): New TCB flags.
(QUAL_HOOK_ENTRY, QUAL_HOOK_EXIT): New qual flags.
(RVAL_HOOKED): New return value flag.
(struct tcb): If built with LuaJIT support, include currpers field even
if SUPPORTED_PERSONALITIES is 1.
If built with LuaJIT support, include new ad_hoc_inject_vals field.
Move definitions that need to be fed to LuaJIT's FFI to...
* defs_shared.h: ...new file.
* ffi.h: New file.
* luajit.h: Likewise.
* luajit_lib.lua: Likewise.
* filter_qualify.c: (hook_entry_set, hook_exit_set): New sets (if built
with LuaJIT support).
(parse_inject_token, qualify_inject_common): Update for new layout of
struct inject_opts.
(alloc_hook_sets, set_hook_qual, set_hook_qual_all): New functions (if
built with LuaJIT support).
(qual_flags): Introduce QUALBIT macro.
If built with LuaJIT support, return QUAL_HOOK_ENTRY and QUAL_HOOK_EXIT
flags.
* number_set.c (number_unsetbit, remove_number_from_set,
extend_set_with_number, make_number_set_universal,
extend_set_array_with_number, make_number_set_array_universal): New
functions.
* strace.1 (LUA SCRIPTING): New section.
* strace.c (alloctcb): update the condition of presence of currpers
field.
(init): New -l option (if built with LuaJIT support).
(enum trace_event): New TE_SYSCALL_STOP_HOOK_EXIT entry.
(enum hook_state): New enum.
(trace_syscall): Introduce state argument.
(dispatch_event): Introduce hooked argument, support
TE_SYSCALL_STOP_HOOK_EXIT as first argument.
(main): run Lua script, if built with LuaJIT support and a script
was provided.
* syscall.c (errnoent_vec, nerrnoent_vec, signalent_vec,
nsignalent_vec, ioctlent_vec, nioctlent_vec, personality_wordsize,
personality_klongsize): New global variables.
(personality_names): New global variable (if SUPPORTED_PERSONALITIES >
1).
(update_personality): use personality_names for reporting personality
name.
(tcb_inject_opts): Introduce step argument, change return type to struct
inject_values, rename to tcb_inject_values.
If built with LuaJIT support and TCB_AD_HOC_INJECT flag is set, blend
the result with tcp's ad_hoc_inject_vals.
(tamper_with_syscall_entering): Don't copy inject_vec here and do
counter decrement logic here; pass true as a second argument to
tcb_inject_values.
(tamper_with_syscall_exiting): Pass false as a second argument to
tcb_inject_values.
(syscall_ad_hoc_inject): New function.
(syscall_entering_trace): perform ad hoc injection even if the syscall
is not traced.
(syscall_exiting_decode): don't return 0 ("bail out") if exiting hook is
set up for this syscall, or if an ad hoc injection was performed.
Call tamper_with_syscall_exiting on success.
(syscall_exiting_trace): Don't call tamper_with_syscall_exiting, check
if the syscall is not traced again.
(syscall_exiting_finish): Clear TCB_AD_HOC_INJECT bit.
* sysent.h: Modify to support inclusion with FFI_CDEF.
---
.gitignore | 1 +
Makefile.am | 17 ++
NEWS | 1 +
basic_filters.c | 60 +++--
configure.ac | 36 +++
defs.h | 72 +++---
defs_shared.h | 66 +++++
ffi.h | 19 ++
filter_qualify.c | 84 +++++--
luajit.h | 311 +++++++++++++++++++++++
luajit_lib.lua | 378 ++++++++++++++++++++++++++++
number_set.c | 47 ++++
number_set.h | 15 ++
strace.1.in | 748 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
strace.c | 95 +++++--
syscall.c | 234 ++++++++++++-----
sysent.h | 24 +-
17 files changed, 2036 insertions(+), 172 deletions(-)
create mode 100644 defs_shared.h
create mode 100644 ffi.h
create mode 100644 luajit.h
create mode 100644 luajit_lib.lua
diff --git a/.gitignore b/.gitignore
index 6b226fba..ae78c075 100644
--- a/.gitignore
+++ b/.gitignore
@@ -32,6 +32,7 @@
/libmpers-m32.a
/libmpers-mx32.a
/libstrace.a
+/luajit_lib.h
/m32_funcs.h
/m32_printer_decls.h
/m32_printer_defs.h
diff --git a/Makefile.am b/Makefile.am
index b3afc7c5..094aa903 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -107,6 +107,7 @@ strace_SOURCES = \
copy_file_range.c \
count.c \
defs.h \
+ defs_shared.h \
desc.c \
dirent.c \
dirent64.c \
@@ -131,6 +132,7 @@ strace_SOURCES = \
fetch_struct_stat.c \
fetch_struct_stat64.c \
fetch_struct_statfs.c \
+ ffi.h \
file_handle.c \
file_ioctl.c \
filter_qualify.c \
@@ -330,6 +332,12 @@ strace_LDFLAGS += $(libunwind_LDFLAGS)
strace_LDADD += $(libunwind_LIBS)
endif
+if USE_LUAJIT
+strace_SOURCES += luajit.h
+strace_CPPFLAGS += $(LUAJIT_CFLAGS)
+strace_LDADD += $(LUAJIT_LIBS)
+endif
+
@CODE_COVERAGE_RULES@
CODE_COVERAGE_BRANCH_COVERAGE = 1
CODE_COVERAGE_GENHTML_OPTIONS = $(CODE_COVERAGE_GENHTML_OPTIONS_DEFAULT) \
@@ -858,6 +866,7 @@ EXTRA_DIST = \
linux/xtensa/set_scno.c \
linux/xtensa/syscallent.h \
linux/xtensa/userent.h \
+ luajit_lib.lua \
mpers.awk \
mpers.sh \
mpers_test.sh \
@@ -884,6 +893,9 @@ $(srcdir)/.version:
strace_SOURCES_c = \
$(filter %.c,$(strace_SOURCES)) $(filter %.c,$(libstrace_a_SOURCES))
+luajit_lib.h: luajit_lib.lua
+ sed 's/["\\]/\\\0/g;s/.*/"\0\\n"/' $< > $@
+
sys_func.h: $(patsubst %,$(srcdir)/%,$(strace_SOURCES_c))
for f in $^; do \
sed -n 's/^SYS_FUNC(.*/extern &;/p' $$f; \
@@ -963,6 +975,11 @@ CLEANFILES = $(ioctl_redefs_h) $(ioctlent_h)
$(mpers_preproc_files) \
native_printer_decls.h native_printer_defs.h printers.h sen.h
sys_func.h
DISTCLEANFILES = gnu/stubs-32.h gnu/stubs-x32.h
+if USE_LUAJIT
+BUILT_SOURCES += luajit_lib.h
+CLEANFILES += luajit_lib.h
+endif
+
include scno.am
$(strace_OBJECTS): scno.h
diff --git a/NEWS b/NEWS
index dbff0dec..3bcb0ad6 100644
--- a/NEWS
+++ b/NEWS
@@ -2,6 +2,7 @@ Noteworthy changes in release ?.?? (????-??-??)
===============================================
* Improvements
+ * Added optional support for LuaJIT scripting (-l FILE option).
* Enhanced decoding of optlen argument of getsockopt syscall.
* Enhanced decoding of SO_LINGER option of getsockopt and setsockopt
syscalls.
* Enhanced decoding of SO_PEERCRED option of getsockopt syscall.
diff --git a/basic_filters.c b/basic_filters.c
index 7b7f0a54..0f31fd32 100644
--- a/basic_filters.c
+++ b/basic_filters.c
@@ -94,40 +94,38 @@ qualify_syscall_regex(const char *s, struct number_set *set)
return found;
}
+const struct syscall_class syscall_classes[] = {
+ { "desc", TRACE_DESC },
+ { "file", TRACE_FILE },
+ { "memory", TRACE_MEMORY },
+ { "process", TRACE_PROCESS },
+ { "signal", TRACE_SIGNAL },
+ { "ipc", TRACE_IPC },
+ { "network", TRACE_NETWORK },
+ { "%desc", TRACE_DESC },
+ { "%file", TRACE_FILE },
+ { "%memory", TRACE_MEMORY },
+ { "%process", TRACE_PROCESS },
+ { "%signal", TRACE_SIGNAL },
+ { "%ipc", TRACE_IPC },
+ { "%network", TRACE_NETWORK },
+ { "%stat", TRACE_STAT },
+ { "%lstat", TRACE_LSTAT },
+ { "%fstat", TRACE_FSTAT },
+ { "%%stat", TRACE_STAT_LIKE },
+ { "%statfs", TRACE_STATFS },
+ { "%fstatfs", TRACE_FSTATFS },
+ { "%%statfs", TRACE_STATFS_LIKE },
+ {}
+};
+
static unsigned int
lookup_class(const char *s)
{
- static const struct {
- const char *name;
- unsigned int value;
- } syscall_class[] = {
- { "desc", TRACE_DESC },
- { "file", TRACE_FILE },
- { "memory", TRACE_MEMORY },
- { "process", TRACE_PROCESS },
- { "signal", TRACE_SIGNAL },
- { "ipc", TRACE_IPC },
- { "network", TRACE_NETWORK },
- { "%desc", TRACE_DESC },
- { "%file", TRACE_FILE },
- { "%memory", TRACE_MEMORY },
- { "%process", TRACE_PROCESS },
- { "%signal", TRACE_SIGNAL },
- { "%ipc", TRACE_IPC },
- { "%network", TRACE_NETWORK },
- { "%stat", TRACE_STAT },
- { "%lstat", TRACE_LSTAT },
- { "%fstat", TRACE_FSTAT },
- { "%%stat", TRACE_STAT_LIKE },
- { "%statfs", TRACE_STATFS },
- { "%fstatfs", TRACE_FSTATFS },
- { "%%statfs", TRACE_STATFS_LIKE },
- };
-
- unsigned int i;
- for (i = 0; i < ARRAY_SIZE(syscall_class); ++i) {
- if (strcmp(s, syscall_class[i].name) == 0) {
- return syscall_class[i].value;
+ const struct syscall_class *c;
+ for (c = syscall_classes; c->name; ++c) {
+ if (strcmp(s, c->name) == 0) {
+ return c->value;
}
}
diff --git a/configure.ac b/configure.ac
index b4abdf8b..9ae4f949 100644
--- a/configure.ac
+++ b/configure.ac
@@ -716,6 +716,42 @@ AC_SUBST(dl_LIBS)
AC_PATH_PROG([PERL], [perl])
+dnl LuaJIT scripting support
+use_luajit=no
+force_luajit=no
+luajit_lib=luajit
+LUAJIT_LIBS=
+LUAJIT_CFLAGS=
+AC_ARG_WITH([luajit],
+ [AS_HELP_STRING([--with-luajit],
+ [build with LuaJIT scripting support, or use use
Lua library with provided name])],
+ [case "${withval}" in
+ yes) force_luajit=yes ;;
+ check) ;;
+ *) force_luajit=yes; luajit_lib="${withval}" ;;
+ esac],
+ [:]
+ )
+AS_IF([test "x$luajit_lib" != xno],
+ [PKG_CHECK_MODULES([LUAJIT],
+ [$luajit_lib],
+ [use_luajit=yes],
+ [AS_IF([test "x$force_luajit" = xyes],
+ [AC_MSG_ERROR([cannot find luajit library:
$luajit_lib])]
+ )]
+ )]
+ )
+
+dnl enable LuaJIT
+AC_MSG_CHECKING([whether to enable Lua scripting])
+if test "x$use_luajit" = xyes; then
+ AC_DEFINE([USE_LUAJIT], 1, [Enable Lua scripting support])
+ AC_SUBST(LUAJIT_LIBS)
+ AC_SUBST(LUAJIT_CFLAGS)
+fi
+AM_CONDITIONAL([USE_LUAJIT], [test "x$use_luajit" = xyes])
+AC_MSG_RESULT([$use_luajit])
+
dnl stack trace with libunwind
libunwind_CPPFLAGS=
libunwind_LDFLAGS=
diff --git a/defs.h b/defs.h
index 92cde26e..957c2d29 100644
--- a/defs.h
+++ b/defs.h
@@ -175,54 +175,21 @@ extern char *stpcpy(char *dst, const char *src);
# define PERSONALITY2_INCLUDE_FUNCS "empty.h"
#endif
-typedef struct ioctlent {
- const char *symbol;
- unsigned int code;
-} struct_ioctlent;
+struct inject_values {
+ uint16_t signo;
+ int rval;
+};
struct inject_opts {
uint16_t first;
uint16_t step;
- uint16_t signo;
- int rval;
+ struct inject_values vals;
};
#define MAX_ERRNO_VALUE 4095
-#define INJECT_OPTS_RVAL_DEFAULT (-(MAX_ERRNO_VALUE + 1))
-
-/* Trace Control Block */
-struct tcb {
- int flags; /* See below for TCB_ values */
- int pid; /* If 0, this tcb is free */
- int qual_flg; /* qual_flags[scno] or DEFAULT_QUAL_FLAGS + RAW
*/
- unsigned long u_error; /* Error code */
- kernel_ulong_t scno; /* System call number */
- kernel_ulong_t u_arg[MAX_ARGS]; /* System call arguments */
- kernel_long_t u_rval; /* Return value */
-#if SUPPORTED_PERSONALITIES > 1
- unsigned int currpers; /* Personality at the time of scno update */
-#endif
- int sys_func_rval; /* Syscall entry parser's return value */
- int curcol; /* Output column for this process */
- FILE *outf; /* Output file for this process */
- const char *auxstr; /* Auxiliary info from syscall (see RVAL_STR) */
- void *_priv_data; /* Private data for syscall decoding functions
*/
- void (*_free_priv_data)(void *); /* Callback for freeing priv_data */
- const struct_sysent *s_ent; /* sysent[scno] or dummy struct for bad
scno */
- const struct_sysent *s_prev_ent; /* for "resuming interrupted SYSCALL"
msg */
- struct inject_opts *inject_vec[SUPPORTED_PERSONALITIES];
- struct timeval stime; /* System time usage as of last process wait */
- struct timeval dtime; /* Delta for system time usage */
- struct timeval etime; /* Syscall entry time */
+#define INJECT_VALS_RVAL_DEFAULT (-(MAX_ERRNO_VALUE + 1))
-#ifdef USE_LIBUNWIND
- struct UPT_info *libunwind_ui;
- struct mmap_cache_t *mmap_cache;
- unsigned int mmap_cache_size;
- unsigned int mmap_cache_generation;
- struct queue_t *queue;
-#endif
-};
+#include "defs_shared.h"
/* TCB flags */
/* We have attached to this process, but did not see it stopping yet */
@@ -246,6 +213,8 @@ struct tcb {
#define TCB_TAMPERED 0x40 /* A syscall has been tampered with */
#define TCB_HIDE_LOG 0x80 /* We should hide everything (until execve) */
#define TCB_SKIP_DETACH_ON_FIRST_EXEC 0x100 /* -b execve should skip detach
on first execve */
+#define TCB_AD_HOC_INJECT 0x200 /* an ad hoc injection was performed by
Lua script */
+#define TCB_HOOK 0x400 /* there is Lua hook for this syscall entry or
exit */
/* qualifier flags */
#define QUAL_TRACE 0x001 /* this system call should be traced */
@@ -256,6 +225,8 @@ struct tcb {
#define QUAL_SIGNAL 0x100 /* report events with this signal */
#define QUAL_READ 0x200 /* dump data read from this file descriptor */
#define QUAL_WRITE 0x400 /* dump data written to this file descriptor */
+#define QUAL_HOOK_ENTRY 0x800 /* return this syscall on entry from
next_sc() */
+#define QUAL_HOOK_EXIT 0x1000 /* return this syscall on exit from next_sc() */
#define DEFAULT_QUAL_FLAGS (QUAL_TRACE | QUAL_ABBREV | QUAL_VERBOSE)
@@ -307,6 +278,7 @@ extern const struct xlat whence_codes[];
#define RVAL_NONE 040 /* Print nothing */
#define RVAL_DECODED 0100 /* syscall decoding finished */
+#define RVAL_HOOKED 0200 /* there is Lua hook for this syscall entry or
exit */
#define IOCTL_NUMBER_UNKNOWN 0
#define IOCTL_NUMBER_HANDLED 1
@@ -352,6 +324,7 @@ typedef enum {
CFLAG_ONLY_STATS,
CFLAG_BOTH
} cflag_t;
+extern const struct syscall_class syscall_classes[];
extern cflag_t cflag;
extern bool debug_flag;
extern bool Tflag;
@@ -647,6 +620,12 @@ extern void print_ifindex(unsigned int);
extern void qualify(const char *);
extern unsigned int qual_flags(const unsigned int);
+#ifdef USE_LUAJIT
+extern void set_hook_qual(unsigned int scno, unsigned int pers, bool
entry_hook,
+ bool exit_hook);
+extern void set_hook_qual_all(bool entry_hook, bool exit_hook);
+#endif
+
#define DECL_IOCTL(name) \
extern int \
name ## _ioctl(struct tcb *, unsigned int request, kernel_ulong_t arg) \
@@ -939,6 +918,19 @@ extern const char *const errnoent0[];
extern const char *const signalent0[];
extern const struct_ioctlent ioctlent0[];
+extern const char *const *errnoent_vec[SUPPORTED_PERSONALITIES];
+extern const char *const *signalent_vec[SUPPORTED_PERSONALITIES];
+extern const struct_ioctlent *const ioctlent_vec[SUPPORTED_PERSONALITIES];
+extern const unsigned int nerrnoent_vec[SUPPORTED_PERSONALITIES];
+extern const unsigned int nsignalent_vec[SUPPORTED_PERSONALITIES];
+extern const unsigned int nioctlent_vec[SUPPORTED_PERSONALITIES];
+
+extern const int personality_wordsize[SUPPORTED_PERSONALITIES];
+extern const int personality_klongsize[SUPPORTED_PERSONALITIES];
+#if SUPPORTED_PERSONALITIES > 1
+extern const char *const personality_names[];
+#endif
+
#if SUPPORTED_PERSONALITIES > 1
extern const struct_sysent *sysent;
extern const char *const *errnoent;
diff --git a/defs_shared.h b/defs_shared.h
new file mode 100644
index 00000000..1fb7a92d
--- /dev/null
+++ b/defs_shared.h
@@ -0,0 +1,66 @@
+/*
+ * Should only be included without FFI_CDEF from defs.h, so no include guards.
+ */
+
+#include "ffi.h"
+
+FFI_CONTENT(
+struct syscall_class {
+ const char *name;
+ unsigned int value;
+};
+)
+
+FFI_CONTENT(
+typedef struct ioctlent {
+ const char *symbol;
+ unsigned int code;
+} struct_ioctlent;
+)
+
+/* Trace Control Block */
+FFI_CONTENT(
+struct tcb {
+ int flags; /* See below for TCB_ values */
+ int pid; /* If 0, this tcb is free */
+ int qual_flg; /* qual_flags[scno] or DEFAULT_QUAL_FLAGS + RAW
*/
+ unsigned long u_error; /* Error code */
+ kernel_ulong_t scno; /* System call number */
+ kernel_ulong_t u_arg[MAX_ARGS]; /* System call arguments */
+ kernel_long_t u_rval; /* Return value */
+)
+
+#if defined(USE_LUAJIT) || SUPPORTED_PERSONALITIES > 1
+FFI_CONTENT(
+ unsigned int currpers; /* Personality at the time of scno update */
+)
+#endif
+
+#ifndef FFI_CDEF
+ int sys_func_rval; /* Syscall entry parser's return value */
+ int curcol; /* Output column for this process */
+ FILE *outf; /* Output file for this process */
+ const char *auxstr; /* Auxiliary info from syscall (see RVAL_STR) */
+ void *_priv_data; /* Private data for syscall decoding functions
*/
+ void (*_free_priv_data)(void *); /* Callback for freeing priv_data */
+ const struct_sysent *s_ent; /* sysent[scno] or dummy struct for bad
scno */
+ const struct_sysent *s_prev_ent; /* for "resuming interrupted SYSCALL"
msg */
+# ifdef USE_LUAJIT
+ struct inject_values ad_hoc_inject_vals;
+# endif
+ struct inject_opts *inject_vec[SUPPORTED_PERSONALITIES];
+ struct timeval stime; /* System time usage as of last process wait */
+ struct timeval dtime; /* Delta for system time usage */
+ struct timeval etime; /* Syscall entry time */
+# ifdef USE_LIBUNWIND
+ struct UPT_info *libunwind_ui;
+ struct mmap_cache_t *mmap_cache;
+ unsigned int mmap_cache_size;
+ unsigned int mmap_cache_generation;
+ struct queue_t *queue;
+# endif
+#endif /* !FFI_CDEF */
+
+FFI_CONTENT(
+};
+)
diff --git a/ffi.h b/ffi.h
new file mode 100644
index 00000000..7b89e7a4
--- /dev/null
+++ b/ffi.h
@@ -0,0 +1,19 @@
+#ifndef STRACE_FFI_H
+#define STRACE_FFI_H
+
+#include "macros.h"
+
+#define FFI_CONCAT(a, b) a ## b
+#define FFI_CONCAT2(a, b) FFI_CONCAT(a, b)
+
+/*
+ * FFI_CONTENT expands to FFI_CONTENT_ (which strigifies its arguments) when
+ * FFI_CDEF is defined, and to FFI_CONTENT_FFI_CDEF (which simply expands to
its
+ * arguments) when it is not.
+ */
+#define FFI_CONTENT FFI_CONCAT2(FFI_CONTENT_, FFI_CDEF)
+
+#define FFI_CONTENT_(...) STRINGIFY(__VA_ARGS__)
+#define FFI_CONTENT_FFI_CDEF(...) __VA_ARGS__
+
+#endif /* !STRACE_FFI_H */
diff --git a/filter_qualify.c b/filter_qualify.c
index b59b19b9..3abe4a53 100644
--- a/filter_qualify.c
+++ b/filter_qualify.c
@@ -40,6 +40,10 @@ static struct number_set *inject_set;
static struct number_set *raw_set;
static struct number_set *trace_set;
static struct number_set *verbose_set;
+#ifdef USE_LUAJIT
+static struct number_set *hook_entry_set;
+static struct number_set *hook_exit_set;
+#endif
static int
sigstr_to_uint(const char *s)
@@ -120,28 +124,28 @@ parse_inject_token(const char *const token, struct
inject_opts *const fopts,
fopts->step = 0;
}
} else if ((val = STR_STRIP_PREFIX(token, "error=")) != token) {
- if (fopts->rval != INJECT_OPTS_RVAL_DEFAULT)
+ if (fopts->vals.rval != INJECT_VALS_RVAL_DEFAULT)
return false;
intval = string_to_uint_upto(val, MAX_ERRNO_VALUE);
if (intval < 0)
intval = find_errno_by_name(val);
if (intval < 1)
return false;
- fopts->rval = -intval;
+ fopts->vals.rval = -intval;
} else if (!fault_tokens_only
&& (val = STR_STRIP_PREFIX(token, "retval=")) != token) {
- if (fopts->rval != INJECT_OPTS_RVAL_DEFAULT)
+ if (fopts->vals.rval != INJECT_VALS_RVAL_DEFAULT)
return false;
intval = string_to_uint(val);
if (intval < 0)
return false;
- fopts->rval = intval;
+ fopts->vals.rval = intval;
} else if (!fault_tokens_only
&& (val = STR_STRIP_PREFIX(token, "signal=")) != token) {
intval = sigstr_to_uint(val);
if (intval < 1 || intval > NSIG_BYTES * 8)
return false;
- fopts->signo = intval;
+ fopts->vals.signo = intval;
} else {
return false;
}
@@ -239,8 +243,10 @@ qualify_inject_common(const char *const str,
struct inject_opts opts = {
.first = 1,
.step = 1,
- .rval = INJECT_OPTS_RVAL_DEFAULT,
- .signo = 0
+ .vals = {
+ .rval = INJECT_VALS_RVAL_DEFAULT,
+ .signo = 0,
+ }
};
char *buf = NULL;
char *name = parse_inject_expression(str, &buf, &opts,
fault_tokens_only);
@@ -249,10 +255,10 @@ qualify_inject_common(const char *const str,
}
/* If neither of retval, error, or signal is specified, then ... */
- if (opts.rval == INJECT_OPTS_RVAL_DEFAULT && !opts.signo) {
+ if (opts.vals.rval == INJECT_VALS_RVAL_DEFAULT && !opts.vals.signo) {
if (fault_tokens_only) {
/* in fault= syntax the default error code is ENOSYS. */
- opts.rval = -ENOSYS;
+ opts.vals.rval = -ENOSYS;
} else {
/* in inject= syntax this is not allowed. */
error_msg_and_die("invalid %s '%s'", description, str);
@@ -353,17 +359,57 @@ qualify(const char *str)
opt->qualify(str);
}
+#ifdef USE_LUAJIT
+static void
+alloc_hook_sets(void)
+{
+ if (!hook_entry_set)
+ hook_entry_set = alloc_number_set_array(
+ SUPPORTED_PERSONALITIES);
+ if (!hook_exit_set)
+ hook_exit_set = alloc_number_set_array(
+ SUPPORTED_PERSONALITIES);
+}
+
+void
+set_hook_qual(unsigned int scno, unsigned int pers, bool entry_hook,
+ bool exit_hook)
+{
+ alloc_hook_sets();
+ if (entry_hook)
+ extend_set_array_with_number(scno, hook_entry_set, pers);
+ if (exit_hook)
+ extend_set_array_with_number(scno, hook_exit_set, pers);
+}
+
+void
+set_hook_qual_all(bool entry_hook, bool exit_hook)
+{
+ alloc_hook_sets();
+ if (entry_hook)
+ make_number_set_array_universal(hook_entry_set,
+ SUPPORTED_PERSONALITIES);
+ if (exit_hook)
+ make_number_set_array_universal(hook_exit_set,
+ SUPPORTED_PERSONALITIES);
+}
+#endif
+
unsigned int
qual_flags(const unsigned int scno)
{
- return (is_number_in_set_array(scno, trace_set, current_personality)
- ? QUAL_TRACE : 0)
- | (is_number_in_set_array(scno, abbrev_set, current_personality)
- ? QUAL_ABBREV : 0)
- | (is_number_in_set_array(scno, verbose_set,
current_personality)
- ? QUAL_VERBOSE : 0)
- | (is_number_in_set_array(scno, raw_set, current_personality)
- ? QUAL_RAW : 0)
- | (is_number_in_set_array(scno, inject_set, current_personality)
- ? QUAL_INJECT : 0);
+#define QUALBIT(set, qualbit) \
+ (is_number_in_set_array(scno, set, current_personality) ? qualbit : 0)
+
+ return QUALBIT(trace_set, QUAL_TRACE)
+ | QUALBIT(abbrev_set, QUAL_ABBREV)
+ | QUALBIT(verbose_set, QUAL_VERBOSE)
+ | QUALBIT(raw_set, QUAL_RAW)
+ | QUALBIT(inject_set, QUAL_INJECT)
+#ifdef USE_LUAJIT
+ | QUALBIT(hook_entry_set, QUAL_HOOK_ENTRY)
+ | QUALBIT(hook_exit_set, QUAL_HOOK_EXIT)
+#endif
+ ;
+#undef QUALBIT
}
diff --git a/luajit.h b/luajit.h
new file mode 100644
index 00000000..fc17c8f9
--- /dev/null
+++ b/luajit.h
@@ -0,0 +1,311 @@
+/*
+ * Should only be included from strace.c, so no include guards.
+ */
+
+#include <lualib.h>
+#include <lauxlib.h>
+
+#define L script_L
+
+static struct tcb *
+func_next_sc(void)
+{
+ static bool first = true;
+ if (!first) {
+ if (!current_tcp)
+ return NULL;
+ if (!dispatch_event(TE_SYSCALL_STOP_HOOK_EXIT, NULL, NULL,
+ true))
+ goto term;
+ }
+ first = false;
+
+ while (1) {
+ int status;
+ siginfo_t si;
+ enum trace_event ret = next_event(&status, &si);
+ if (!dispatch_event(ret, &status, &si, true))
+ goto term;
+ if (ret == TE_SYSCALL_STOP && (current_tcp->flags & TCB_HOOK)) {
+ current_tcp->flags &= ~TCB_HOOK;
+ return current_tcp;
+ }
+ }
+
+term:
+ current_tcp = NULL;
+ return NULL;
+}
+
+static bool
+func_monitor(unsigned int scno, unsigned int pers, bool entry_hook,
+ bool exit_hook)
+{
+ if (pers >= SUPPORTED_PERSONALITIES)
+ return false;
+ set_hook_qual(scno, pers, entry_hook, exit_hook);
+ return true;
+}
+
+static void
+prepare_ad_hoc_inject(void)
+{
+ if (!(current_tcp->flags & TCB_AD_HOC_INJECT)) {
+ current_tcp->ad_hoc_inject_vals.signo = 0;
+ current_tcp->ad_hoc_inject_vals.rval = INJECT_VALS_RVAL_DEFAULT;
+ current_tcp->qual_flg |= QUAL_INJECT;
+ current_tcp->flags |= TCB_AD_HOC_INJECT;
+ }
+}
+
+static bool
+func_inject_signo(int signo)
+{
+ if (!current_tcp || exiting(current_tcp))
+ return false;
+ if (signo <= 0 || signo > SIGRTMAX)
+ return false;
+ prepare_ad_hoc_inject();
+ current_tcp->ad_hoc_inject_vals.signo = signo;
+ return true;
+}
+
+static bool
+func_inject_retval(int retval)
+{
+ if (!current_tcp || exiting(current_tcp))
+ return false;
+ if (retval < -MAX_ERRNO_VALUE)
+ return false;
+ prepare_ad_hoc_inject();
+ current_tcp->ad_hoc_inject_vals.rval = retval;
+ return true;
+}
+
+static int
+func_umove(kernel_ulong_t addr, size_t len, void *laddr)
+{
+ return current_tcp ? umoven(current_tcp, addr, len, laddr) : -1;
+}
+
+static int
+func_umove_str(kernel_ulong_t addr, size_t len, char *laddr)
+{
+ return current_tcp ? umovestr(current_tcp, addr, len, laddr) : -1;
+}
+
+static bool
+func_path_match(const char **set, size_t nset)
+{
+ if (!current_tcp)
+ return false;
+ struct path_set s = {set, nset};
+ return pathtrace_match_set(current_tcp, &s);
+}
+
+static const char *
+get_lua_msg(void)
+{
+ const char *msg = lua_tostring(L, -1);
+ return msg ? msg : "(error object can't be converted to string)";
+}
+
+static void
+assert_lua_impl(int ret, const char *expr, const char *file, int line)
+{
+ if (ret == 0)
+ return;
+ error_msg_and_die("assert_lua(%s) failed at %s:%d: %s", expr, file,
+ line, get_lua_msg());
+}
+
+#define assert_lua(expr) assert_lua_impl(expr, #expr, __FILE__, __LINE__)
+
+static void
+check_lua(int ret)
+{
+ if (ret == 0)
+ return;
+ error_msg_and_die("lua: %s", get_lua_msg());
+}
+
+#ifdef LUA_FFILIBNAME
+# define FFILIBNAME LUA_FFILIBNAME
+#else
+/* non-LuaJIT */
+# define FFILIBNAME "ffi"
+#endif
+
+#ifdef LUA_BITLIBNAME
+# define BITLIBNAME LUA_BITLIBNAME
+#else
+/* Lua <= 5.1 (non-LuaJIT) */
+# define BITLIBNAME "bit"
+#endif
+
+static void
+init_luajit(const char *scriptfile)
+{
+ if (L)
+ /* already initialized? */
+ error_msg_and_help("multiple -l arguments");
+
+ if (!(L = luaL_newstate()))
+ error_msg_and_die("luaL_newstate failed (out of memory?)");
+
+ luaL_openlibs(L);
+
+ lua_getglobal(L, "require"); /* L: require */
+ lua_pushstring(L, FFILIBNAME); /* L: require str */
+ assert_lua(lua_pcall(L, 1, 1, 0)); /* L: ffi */
+ lua_getfield(L, -1, "cdef"); /* L: ffi cdef */
+ luaL_Buffer b;
+ luaL_buffinit(L, &b); /* L: ffi cdef ? */
+ {
+ char buf[128];
+ snprintf(buf, sizeof(buf),
+ "typedef int%d_t kernel_long_t;"
+ "typedef uint%d_t kernel_ulong_t;",
+ (int) sizeof(kernel_long_t) * 8,
+ (int) sizeof(kernel_ulong_t) * 8);
+ luaL_addstring(&b, buf); /* L: ffi cdef ? */
+ }
+ const char *defs =
+#define FFI_CDEF
+#include "sysent.h"
+#include "defs_shared.h"
+#undef FFI_CDEF
+ ;
+ luaL_addstring(&b, defs); /* L: ffi cdef ? */
+ luaL_pushresult(&b); /* L: ffi cdef str */
+ assert_lua(lua_pcall(L, 1, 0, 0)); /* L: ffi */
+
+ lua_newtable(L); /* L: ffi strace */
+ lua_newtable(L); /* L: ffi strace C */
+
+ lua_getfield(L, 1, "cast"); /* L: ffi strace C cast */
+ lua_remove(L, 1); /* L: strace C cast */
+
+#define EXPOSE_FUNC(rettype, ptr, name, ...) \
+ do { \
+ rettype (*fptr_)(__VA_ARGS__) = ptr; \
+ lua_pushvalue(L, -1); /* L: strace C cast cast */ \
+ lua_pushstring(L, #rettype " (*)(" #__VA_ARGS__ ")"); \
+ /* L: strace C cast cast str */ \
+ lua_pushlightuserdata(L, * (void **) (&fptr_)); \
+ /* L: strace C cast cast str ptr */ \
+ assert_lua(lua_pcall(L, 2, 1, 0)); \
+ /* L: strace C cast value */ \
+ lua_setfield(L, -3, name); /* L: strace C cast */ \
+ } while (0)
+
+ EXPOSE_FUNC(bool, func_monitor, "monitor",
+ unsigned int, unsigned int, bool, bool);
+ EXPOSE_FUNC(void, set_hook_qual_all, "monitor_all",
+ bool, bool);
+ EXPOSE_FUNC(struct tcb *, func_next_sc, "next_sc",
+ void);
+ EXPOSE_FUNC(bool, func_inject_signo, "inject_signo",
+ int);
+ EXPOSE_FUNC(bool, func_inject_retval, "inject_retval",
+ int);
+ EXPOSE_FUNC(int, func_umove, "umove",
+ kernel_ulong_t, size_t, void *);
+ EXPOSE_FUNC(int, func_umove_str, "umove_str",
+ kernel_ulong_t, size_t, char *);
+ EXPOSE_FUNC(bool, func_path_match, "path_match",
+ const char **, size_t);
+
+#undef EXPOSE_FUNC
+
+#define EXPOSE(type, ptr, name)
\
+ do { \
+ /* Get a compilation error/warning on type mismatch */ \
+ type tmp_ = ptr; \
+ (void) tmp_; \
+ lua_pushvalue(L, -1); /* L: strace C cast cast */ \
+ lua_pushstring(L, #type); \
+ /* L: strace C cast cast str */ \
+ lua_pushlightuserdata(L, (void *) ptr); \
+ /* L: strace C cast cast str ptr */ \
+ assert_lua(lua_pcall(L, 2, 1, 0)); \
+ /* L: strace C cast value */ \
+ lua_setfield(L, -3, name); /* L: strace C cast */ \
+ } while (0)
+
+ EXPOSE(const struct_sysent *const *, sysent_vec, "sysent_vec");
+ EXPOSE(const char *const **, errnoent_vec, "errnoent_vec");
+ EXPOSE(const char *const **, signalent_vec, "signalent_vec");
+ EXPOSE(const struct_ioctlent *const *, ioctlent_vec, "ioctlent_vec");
+
+ EXPOSE(const unsigned int *, nsyscall_vec, /*(!)*/ "nsysent_vec");
+ EXPOSE(const unsigned int *, nerrnoent_vec, "nerrnoent_vec");
+ EXPOSE(const unsigned int *, nsignalent_vec, "nsignalent_vec");
+ EXPOSE(const unsigned int *, nioctlent_vec, "nioctlent_vec");
+
+ EXPOSE(const struct syscall_class *, syscall_classes,
+ "syscall_classes");
+
+#if SUPPORTED_PERSONALITIES == 1
+ static const char *const personality_names[] = {#__WORDSIZE " bit"};
+#endif
+ EXPOSE(const char *const *, personality_names, "pers_name");
+ EXPOSE(const int *, personality_wordsize, "pers_wordsize");
+ EXPOSE(const int *, personality_klongsize, "pers_klongsize");
+
+#undef EXPOSE
+
+ lua_pop(L, 1); /* L: strace C */
+ lua_setfield(L, -2, "C"); /* L: strace */
+
+ lua_pushinteger(L, SUPPORTED_PERSONALITIES); /* L: strace int */
+ lua_setfield(L, -2, "npersonalities"); /* L: strace */
+
+ lua_pushinteger(L, MAX_ARGS); /* L: strace int */
+ lua_setfield(L, -2, "max_args"); /* L: strace */
+
+ lua_pushinteger(L, PATH_MAX); /* L: strace int */
+ lua_setfield(L, -2, "path_max"); /* L: strace */
+
+ lua_setglobal(L, "strace"); /* L: - */
+
+ const char *code =
+#include "luajit_lib.h"
+ ;
+ assert_lua(luaL_loadstring(L, code)); /* L: chunk */
+
+ lua_newtable(L); /* L: chunk table */
+
+ lua_pushstring(L, FFILIBNAME); /* L: chunk table str */
+ lua_setfield(L, -2, "ffilibname"); /* L: chunk table */
+ lua_pushstring(L, BITLIBNAME); /* L: chunk table str */
+ lua_setfield(L, -2, "bitlibname"); /* L: chunk table */
+ lua_pushinteger(L, TCB_INSYSCALL); /* L: chunk table int */
+ lua_setfield(L, -2, "tcb_insyscall"); /* L: chunk table */
+ lua_pushinteger(L, QUAL_TRACE); /* L: chunk table int */
+ lua_setfield(L, -2, "qual_trace"); /* L: chunk table */
+ lua_pushinteger(L, QUAL_ABBREV); /* L: chunk table int */
+ lua_setfield(L, -2, "qual_abbrev"); /* L: chunk table */
+ lua_pushinteger(L, QUAL_VERBOSE); /* L: chunk table int */
+ lua_setfield(L, -2, "qual_verbose"); /* L: chunk table */
+ lua_pushinteger(L, QUAL_RAW); /* L: chunk table int */
+ lua_setfield(L, -2, "qual_raw"); /* L: chunk table */
+
+ assert_lua(lua_pcall(L, 1, 1, 0)); /* L: func */
+
+ check_lua(luaL_loadfile(L, scriptfile)); /* L: func chunk */
+}
+
+static void ATTRIBUTE_NORETURN
+run_luajit(void)
+{
+ /* L: func chunk */
+ check_lua(lua_pcall(L, 0, 0, 0)); /* L: func */
+ check_lua(lua_pcall(L, 0, 0, 0)); /* L: - */
+ terminate();
+}
+
+#undef FFILIBNAME
+#undef BITLIBNAME
+#undef assert_lua
+#undef L
diff --git a/luajit_lib.lua b/luajit_lib.lua
new file mode 100644
index 00000000..6280890e
--- /dev/null
+++ b/luajit_lib.lua
@@ -0,0 +1,378 @@
+-- This "chunk" of code is loaded and run before the script is.
+--
+-- To quote https://www.lua.org/manual/5.1/manual.html#2.4.1,
+-- "Lua handles a chunk as the body of an anonymous function with a variable
+-- number of arguments (see ยง2.5.9). As such, chunks can define local
+-- variables, receive arguments, and return values."
+--
+-- Thanks to Lua's support for closures, all the local variables defined here
+-- will not leak to another chunks (i.e., the script), but all the functions
+-- defined here can still access them.
+--
+-- strace calls this chunk with a single argument: a table with data that
should
+-- not be exposed to the script, but is needed for some API functions defined
+-- here.
+--
+-- strace expects this chunk to return another function that will be run after
+-- the script returns.
+--
+-- Arguments passed to this chunk are accessible through the "..." vararg
+-- expression. The following line uses Lua's "adjust" assignment semantics to
+-- assign the first argument to a local variable "priv".
+local priv = ...
+
+local ffi = require(priv.ffilibname)
+ffi.cdef[[
+int strcmp(const char *, const char *);
+]]
+local bit = require(priv.bitlibname)
+
+local entry_cbs, exit_cbs, at_exit_cb = {}, {}, nil
+for p = 0, strace.npersonalities - 1 do
+ entry_cbs[p] = {}
+ exit_cbs[p] = {}
+end
+
+local nullptr = ffi.NULL
+pcall(function()
+ nullptr = ffi.C.NULL
+end)
+
+local function chain(f, g)
+ if not f then
+ return g
+ end
+ return function(...)
+ f(...)
+ g(...)
+ end
+end
+
+local function register_hook(scno, pers, on_entry, on_exit, cb)
+ assert(not not strace.C.monitor(scno, pers, on_entry, on_exit))
+ scno, pers = tonumber(scno), tonumber(pers)
+ if on_entry then
+ entry_cbs[pers][scno] = chain(entry_cbs[pers][scno], cb)
+ end
+ if on_exit then
+ exit_cbs[pers][scno] = chain(exit_cbs[pers][scno], cb)
+ end
+end
+
+function strace.entering(tcp)
+ return bit.band(tcp.flags, priv.tcb_insyscall) == 0
+end
+
+function strace.exiting(tcp)
+ return bit.band(tcp.flags, priv.tcb_insyscall) ~= 0
+end
+
+local function alter_trace_opt(flagbit, tcp, ...)
+ if strace.exiting(tcp) then
+ return false
+ end
+ -- i.e., if ... is empty, or the first element of ... is true
+ if select('#', ...) == 0 or select(1, ...) then
+ tcp.qual_flg = bit.bor(tcp.qual_flg, flagbit)
+ else
+ tcp.qual_flg = bit.band(tcp.qual_flg, bit.bnot(flagbit))
+ end
+ return true
+end
+for funcname, flagbit in pairs{
+ trace = priv.qual_trace,
+ abbrev = priv.qual_abbrev,
+ verbose = priv.qual_verbose,
+ raw = priv.qual_raw,
+} do
+ strace[funcname] = function(tcp, ...)
+ return alter_trace_opt(flagbit, tcp, ...)
+ end
+end
+
+function strace.ptr_to_kulong(ptr)
+ return ffi.cast('kernel_ulong_t', ffi.cast('unsigned long', ptr))
+end
+
+function strace.at_exit(f)
+ at_exit_cb = chain(at_exit_cb, f)
+end
+
+function strace.get_sc_name(scno, pers)
+ if scno < 0 or scno >= strace.C.nsysent_vec[pers] then
+ return nil
+ end
+ local s = strace.C.sysent_vec[pers][scno].sys_name
+ return s ~= nullptr and ffi.string(s) or nil
+end
+
+function strace.get_sig_name(signo, pers)
+ if signo < 0 or signo >= strace.C.nsignalent_vec[pers] then
+ return nil
+ end
+ local s = strace.C.signalent_vec[pers][signo]
+ return s ~= nullptr and ffi.string(s) or nil
+end
+
+function strace.get_err_name(err, pers)
+ if err < 0 or err > strace.C.nerrnoent_vec[pers] then
+ return nil
+ end
+ local s = strace.C.errnoent_vec[pers][err]
+ return s ~= nullptr and ffi.string(s) or nil
+end
+
+function strace.get_ioctl_name(code, pers)
+ -- we could have provided a definition for stdlib's bsearch() and used
+ -- it, but LuaJIT's FFI manual says generated callbacks are a limited
+ -- resource and also slow. So implement binary search ourselves.
+ local lb, rb = ffi.cast('unsigned int', 0), strace.C.nioctlent_vec[pers]
+ if rb == 0 then
+ return nil
+ end
+ local arr = strace.C.ioctlent_vec[pers]
+ while rb - lb > 1 do
+ local mid = lb + (rb - lb) / 2
+ if arr[mid].code <= code then
+ lb = mid
+ else
+ rb = mid
+ end
+ end
+ return arr[lb].code == code and ffi.string(arr[lb].symbol) or nil
+end
+
+function strace.get_ioctl_code(name, pers)
+ local cstr = ffi.cast('const char *', name)
+ local arr = strace.C.ioctlent_vec[pers]
+ for i = 0, strace.C.nioctlent_vec[pers] do
+ if ffi.C.strcmp(arr[i].symbol, cstr) == 0 then
+ return arr[i].code
+ end
+ end
+ return nil
+end
+
+function strace.get_scno(scname, pers)
+ local cstr = ffi.cast('const char *', scname)
+ for i = 0, tonumber(strace.C.nsysent_vec[pers]) - 1 do
+ local s = strace.C.sysent_vec[pers][i].sys_name
+ if s ~= nullptr and ffi.C.strcmp(s, cstr) == 0 then
+ return i
+ end
+ end
+ return nil
+end
+
+function strace.get_signo(signame, pers)
+ local cstr = ffi.cast('const char *', signame)
+ for i = 0, tonumber(strace.C.nsignalent_vec[pers]) - 1 do
+ local s = strace.C.signalent_vec[pers][i]
+ if s ~= nullptr and ffi.C.strcmp(s, cstr) == 0 then
+ return i
+ end
+ end
+ return nil
+end
+
+function strace.get_errno(errname, pers)
+ local cstr = ffi.cast('const char *', errname)
+ for i = 0, tonumber(strace.C.nerrnoent_vec[pers]) - 1 do
+ local s = strace.C.errnoent_vec[pers][i]
+ if s ~= nullptr and ffi.C.strcmp(s, cstr) == 0 then
+ return i
+ end
+ end
+ return nil
+end
+
+function strace.inject_signal(tcp, sig)
+ local signo = tonumber(sig)
+ if not signo then
+ signo = strace.get_signo(sig, tcp.currpers)
+ if not signo then
+ return false
+ end
+ end
+ return not not strace.C.inject_signo(signo)
+end
+
+function strace.inject_error(tcp, err)
+ local errno = tonumber(err)
+ if not errno then
+ errno = strace.get_errno(err, tcp.currpers)
+ if not errno then
+ return false
+ end
+ end
+ return errno > 0 and not not strace.C.inject_retval(-errno)
+end
+
+local ptr_size = ffi.sizeof('void *')
+
+function strace.read_obj(addr, ct, ...)
+ local obj = ffi.new(ct, ...)
+ local n = ffi.sizeof(obj)
+ -- work around FFI pointer semantics
+ if n == ptr_size then
+ -- It may be a pointer, and it is cheap to create another copy.
+ -- FFI templating ('$ [1]') fails for variable-length arrays, so
+ -- fall back to normal umove in case of error.
+ local is_ok, ret = pcall(function()
+ local t = ffi.typeof(obj)
+ local arr = ffi.typeof('$ [1]', t)()
+ return strace.C.umove(addr, n, arr) == 0 and t(arr[0])
+ or nil
+ end)
+ if is_ok then
+ return ret
+ end
+ end
+ return strace.C.umove(addr, n, obj) == 0 and obj or nil
+end
+
+function strace.read_str(addr, maxsz, bufsz)
+ -- convert it to Lua number to prevent underflows
+ maxsz = tonumber(maxsz or 4 * 1024 * 1024)
+ bufsz = bufsz or 1024
+ local t = {}
+ local buf = ffi.new('char [?]', bufsz)
+ while true do
+ local r = strace.C.umove_str(addr, bufsz, buf)
+ if r < 0 then
+ return nil, 'readerr'
+ elseif r == 0 then
+ maxsz = maxsz - bufsz
+ if maxsz < 0 then
+ return nil, 'toolong'
+ end
+ t[#t + 1] = ffi.string(buf, bufsz)
+ addr = addr + bufsz
+ else
+ local s = ffi.string(buf)
+ if #s > maxsz then
+ return nil, 'toolong'
+ end
+ return table.concat(t) .. s
+ end
+ end
+end
+
+function strace.read_path(addr)
+ return strace.read_str(addr, strace.path_max, strace.path_max)
+end
+
+local function parse_when(when)
+ if type(when) == 'table' then
+ return unpack(when)
+ elseif when == 'entering' then
+ return true, false
+ elseif when == 'exiting' then
+ return false, true
+ elseif when == 'both' then
+ return true, true
+ else
+ error('unknown "when" value')
+ end
+end
+
+local function reduce_or(f, args, ...)
+ local ret = false
+ for _, arg in ipairs(args) do
+ if f(arg, ...) then
+ ret = true
+ end
+ end
+ return ret
+end
+
+function strace.hook(scname, when, cb)
+ local on_entry, on_exit = parse_when(when)
+ if type(scname) == 'table' then
+ return reduce_or(strace.hook, scname, {on_entry, on_exit}, cb)
+ end
+ local found = false
+ for p = 0, strace.npersonalities - 1 do
+ local scno = strace.get_scno(scname, p)
+ if scno then
+ register_hook(scno, p, on_entry, on_exit, cb)
+ found = true
+ end
+ end
+ return found
+end
+
+function strace.hook_class(clsname, when, cb)
+ local on_entry, on_exit = parse_when(when)
+ if type(clsname) == 'table' then
+ return reduce_or(strace.hook_class, clsname,
+ {on_entry, on_exit}, cb)
+ end
+ local cstr = ffi.cast('const char *', clsname)
+ local flag = nil
+ local ptr = strace.C.syscall_classes
+ while ptr.name ~= nullptr do
+ if ffi.C.strcmp(ptr.name, cstr) == 0 then
+ flag = ptr.value
+ break
+ end
+ ptr = ptr + 1
+ end
+ if not flag then
+ return false
+ end
+ for p = 0, strace.npersonalities - 1 do
+ for i = 0, tonumber(strace.C.nsysent_vec[p]) - 1 do
+ if bit.band(strace.C.sysent_vec[p][i].sys_flags, flag)
+ ~= 0
+ then
+ register_hook(i, p, on_entry, on_exit, cb)
+ end
+ end
+ end
+ return true
+end
+
+function strace.hook_scno(scno, pers, when, cb)
+ local on_entry, on_exit = parse_when(when)
+ if type(scno) == 'table' then
+ return reduce_or(strace.hook_scno, scno, pers,
+ {on_entry, on_exit}, cb)
+ end
+ register_hook(scno, pers, on_entry, on_exit, cb)
+end
+
+function strace.path_match(set)
+ if type(set) ~= 'table' then
+ set = {set}
+ end
+ local nset = #set
+ return not not strace.C.path_match(
+ ffi.new('const char *[?]', nset, set), nset)
+end
+
+function print(...)
+ local sep = ''
+ for i = 1, select('#', ...) do
+ io.stderr:write(sep .. tostring(select(i, ...)))
+ sep = '\t'
+ end
+ io.stderr:write('\n')
+end
+
+return function()
+ while true do
+ local tcp = strace.C.next_sc()
+ if tcp == nullptr then
+ break
+ end
+ local cb = (strace.entering(tcp) and entry_cbs or exit_cbs)
+ [tonumber(tcp.currpers)][tonumber(tcp.scno)]
+ if cb then
+ cb(tcp)
+ end
+ end
+ if at_exit_cb then
+ at_exit_cb()
+ end
+end
diff --git a/number_set.c b/number_set.c
index b8aa28c7..a2e049a1 100644
--- a/number_set.c
+++ b/number_set.c
@@ -50,6 +50,12 @@ number_setbit(const unsigned int i, number_slot_t *const vec)
vec[i / BITS_PER_SLOT] |= (number_slot_t) 1 << (i % BITS_PER_SLOT);
}
+static void
+number_unsetbit(const unsigned int i, number_slot_t *const vec)
+{
+ vec[i / BITS_PER_SLOT] &= ~((number_slot_t) 1 << (i % BITS_PER_SLOT));
+}
+
static bool
number_isset(const unsigned int i, const number_slot_t *const vec)
{
@@ -97,6 +103,29 @@ add_number_to_set(const unsigned int number, struct
number_set *const set)
}
void
+remove_number_from_set(const unsigned int number, struct number_set *const set)
+{
+ if (number / BITS_PER_SLOT < set->nslots)
+ number_unsetbit(number, set->vec);
+}
+
+void
+extend_set_with_number(const unsigned int number, struct number_set *const set)
+{
+ if (set->not)
+ remove_number_from_set(number, set);
+ else
+ add_number_to_set(number, set);
+}
+
+void
+make_number_set_universal(struct number_set *const set)
+{
+ free(set->vec);
+ *set = (struct number_set) { .not = true };
+}
+
+void
add_number_to_set_array(const unsigned int number, struct number_set *const
set,
const unsigned int idx)
{
@@ -104,6 +133,14 @@ add_number_to_set_array(const unsigned int number, struct
number_set *const set,
}
void
+extend_set_array_with_number(const unsigned int number,
+ struct number_set *const set,
+ const unsigned int idx)
+{
+ extend_set_with_number(number, &set[idx]);
+}
+
+void
clear_number_set_array(struct number_set *const set, const unsigned int nmemb)
{
unsigned int i;
@@ -125,6 +162,16 @@ invert_number_set_array(struct number_set *const set,
const unsigned int nmemb)
set[i].not = !set[i].not;
}
+void
+make_number_set_array_universal(struct number_set *set,
+ const unsigned int nmemb)
+{
+ unsigned int i;
+
+ for (i = 0; i < nmemb; ++i)
+ make_number_set_universal(&set[i]);
+}
+
struct number_set *
alloc_number_set_array(const unsigned int nmemb)
{
diff --git a/number_set.h b/number_set.h
index 967a1c88..81a43c2b 100644
--- a/number_set.h
+++ b/number_set.h
@@ -43,14 +43,29 @@ extern void
add_number_to_set(unsigned int number, struct number_set *);
extern void
+remove_number_from_set(unsigned int number, struct number_set *);
+
+extern void
+extend_set_with_number(unsigned int number, struct number_set *);
+
+extern void
+make_number_set_universal(struct number_set *);
+
+extern void
add_number_to_set_array(unsigned int number, struct number_set *, unsigned int
idx);
extern void
+extend_set_array_with_number(unsigned int number, struct number_set *,
unsigned int idx);
+
+extern void
clear_number_set_array(struct number_set *, unsigned int nmemb);
extern void
invert_number_set_array(struct number_set *, unsigned int nmemb);
+extern void
+make_number_set_array_universal(struct number_set *, unsigned int nmemb);
+
extern struct number_set *
alloc_number_set_array(unsigned int nmemb);
diff --git a/strace.1.in b/strace.1.in
index dc830086..f315e11d 100644
--- a/strace.1.in
+++ b/strace.1.in
@@ -53,6 +53,10 @@
. el \
. BR "\\$1"
..
+.de URL
+\\$2 \(laURL: \\$1 \(ra\\$3
+..
+.if \n[.g] .mso www.tmac
.TH STRACE 1 "@MANPAGE_DATE@" "strace @VERSION@"
.SH NAME
strace \- trace system calls and signals
@@ -795,6 +799,750 @@ Print the help summary.
.B \-V
Print the version number of
.BR strace .
+.SH LUA SCRIPTING
+If built with Lua support,
+.B strace
+can execute Lua scripts.
+A script file is passed to the
+.B -l
+option.
+.PP
+.B strace
+provides the built-in module
+.B strace
+to the Lua execution environment, which contains various functions and
+constants.
+.PP
+Before any tracing takes place, the script is run.
+At this stage, it can do one of the following two things:
+.RS
+.IP \(bu 3
+Implement its own tracing loop by selecting syscalls it wants to be notified
+about with
+.BR strace.C.monitor / strace.C.monitor_all
+and calling
+.B strace.C.next_sc
+in a loop until it returns a null pointer (or return earlier; in this case, the
+installed hooks for the remaining syscalls are run).
+.IP \(bu
+Install syscall and at-exit hooks with
+.BR strace.hook ", " strace.hook_class ", " strace.hook_scno " and "
strace.at_exit .
+.RE
+.PP
+Then,
+.B strace
+enters its own tracing loop, and all the installed hooks are run.
+.SS Personalities
+A personality is an execution domain with its own sets of syscalls, signals and
+errors.
+A
+.I personality number
+is strace-specific 0-based index in the architecture-dependent list of
+personalities.
+.SS FFI
+.URL http://luajit.org/ext_ffi.html "FFI library"
+is an extension provided by LuaJIT;
+.URL https://github.com/jmckaskill/luaffi luaffi
+and
+.URL https://github.com/facebook/luaffifb luaffifb
+standalone implementations are also supported, but only for Lua 5.2.
+.PP
+One may want to look at
+.URL https://github.com/m-schmoock/lcpp lcpp ,
+a pure-Lua implementation of C preprocessor, which integrates with LuaJIT's FFI
+library and supports inclusion of header files and exposing all the definitions
+and macros to the FFI.
+As for now, lcpp does not support system include directories, and treats all
+includes as local.
+.URL https://github.com/umegaya/ffiex ffiex ,
+a library based on it, on the other hand, does support them, and thus can be
+used to preprocess system headers.
+.PP
+.B strace
+provides the following FFI definitions:
+.CW
+typedef /* implementation-defined signed integer type */ kernel_long_t;
+typedef /* implementation-defined unsigned integer type */ kernel_ulong_t;
+
+typedef struct sysent {
+ unsigned nargs; /* Number of arguments */
+ int sys_flags; /* Flags. Currently, only meaningful in the
+ * context of struct syscall_class::value field:
+ * a syscall belongs to a class iff
+ * (class.value & syscall.sys_flags) != 0. */
+ const char *sys_name; /* Name */
+} struct_sysent;
+
+struct syscall_class {
+ const char *name; /* Name */
+ unsigned int value; /* Flag bit, see the comment on struct
+ * sysent::sys_flags field. */
+};
+
+typedef struct ioctlent {
+ const char *symbol;
+ unsigned int code;
+} struct_ioctlent;
+
+/* Trace control block */
+struct tcb {
+ int pid; /* Tracee's PID */
+ unsigned long u_error; /* Error code */
+ kernel_ulong_t scno; /* System call number */
+ kernel_ulong_t u_arg[/* MAX_ARGS */]; /* System call arguments */
+ kernel_ulong_t u_rval; /* Return value */
+ unsigned int currpers; /* Current personality */
+};
+.CE
+.SS strace module: C submodule: functions
+Note: be careful with boxed boolean values and use
+.B not not
+.I boxed_bool
+when in doubt.
+In particular, an
+.B assert
+on a boxed boolean will never raise an error.
+.PP
+Note: not checking the result of
+.B strace.C.next_sc
+against a null pointer is likely the reason you get a segmentation fault.
+Note that unless you select some syscalls with
+.BR strace.C.monitor / strace.C.monitor_all ,
+it will always return a null pointer.
+.TP
+\fIstatus\fR = \fBstrace.C.monitor\fR(\fIscno\fR, \fIpers\fR, \fIon_entry\fR,
\fIon_exit\fR)
+C type:
+.B bool (*)(unsigned int, unsigned int, bool, bool)
+.IP
+Marks the syscall with number
+.I scno
+on personality
+.I pers
+as to be returned from
+.BR strace.next_sc .
+If
+.I on_entry
+is
+.BR true ,
+it is marked as to be returned on syscall entry, and if
+.I on_exit
+is
+.BR true ,
+it is marked as to be returned on syscall exit.
+.IP
+Note that this "marking" is a one-way process, and specifying
+.B false
+as any of the flags does not undo any previous calls to
+.BR strace.C.monitor / strace.C.monitor_all .
+.IP
+Returns
+.B true
+on success and
+.B false
+on failure.
+.TP
+\fBstrace.C.monitor_all\fR(\fIon_entry\fR, \fIon_exit\fR)
+C type:
+.B void (*)(bool, bool)
+.IP
+Marks all syscalls on all personalities as to be returned from
+.BR strace.C.next_sc :
+on syscall entry if
+.I on_entry
+is
+.BR true ,
+and on syscall exit if
+.I on_exit
+is
+.BR true .
+See the note for
+.BR strace.C.monitor .
+.TP
+\fItcp\fR = \fBstrace.C.next_sc\fR()
+C type:
+.B struct tcb * (*)(void)
+.IP
+If this is not the first call to this function, performs tracing and tampering
+of the previously returned syscall.
+.IP
+Waits for the next monitored syscall to happen, and returns a pointer to its
+trace control block.
+.IP
+If
+.B strace
+needs to be terminated (e.g. last tracee has been terminated, or
+.B strace
+has been interrupted), returns a null pointer.
+Once it returned a null pointer, all subsequent calls to it will also return
it.
+.TP
+\fIstatus\fR = \fBstrace.C.inject_signo\fR(\fIsigno\fR)
+C type:
+.B bool (*)(int)
+.IP
+Delivers a signal with number
+.I signo
+to the current tracee.
+.IP
+Note that this must be done on syscall entry.
+.IP
+Returns
+.B true
+on success and
+.B false
+on failure.
+.TP
+\fIstatus\fR = \fBstrace.C.inject_retval\fR(\fIval\fR)
+C type:
+.B bool (*)(int)
+.IP
+Injects a return value to the current syscall invocation.
+.IP
+Note that this must be done on syscall entry.
+.IP
+Returns
+.B true
+on success and
+.B false
+on failure.
+.TP
+\fIstatus\fR = \fBstrace.C.umove\fR(\fIaddr\fR, \fIlen\fR, \fIladdr\fR)
+C type:
+.B int (*)(kernel_ulong_t, size_t, void *)
+.IP
+Copies ("moves")
+.I len
+bytes of data from the current tracee process at address
+.I addr
+to a local address
+.IR laddr .
+.IP
+Returns 0 on success and \-1 on failure.
+.TP
+\fIstatus\fR = \fBstrace.C.umove_str\fR(\fIaddr\fR, \fIlen\fR, \fIladdr\fR)
+C type:
+.B int (*)(kernel_ulong_t, size_t, char *)
+.IP
+Like
+.BR strace.C.umove ,
+but makes the additional effort of looking for a terminating zero byte.
+Returns a negative value on failure, a positive value if a NUL was seen, and 0
+if
+.I len
+bytes were read but no NUL seen.
+.IP
+Note: there is no guarantee it won't overwrite some bytes in \fIladdr\fR after
+terminating NUL (but, of course, it never writes past
+.IR laddr[len-1] ).
+.TP
+\fIstatus\fR = \fBstrace.C.path_match\fR(\fIset\fR, \fInset\fR)
+C type:
+.B bool (*)(const char **, size_t)
+.IP
+Returns
+.B true
+if the current syscall accesses one of the paths from a given set of paths, and
+.B false
+otherwise.
+.IP
+Note: for string path arguments, the path is compared against the set; for file
+descriptor arguments, the absolute path to the file behind the file descriptor
+is compared against the set.
+.SS strace module: C submodule: constants
+.TP
+.B strace.C.sysent_vec
+Array of syscall tables for each of the supported personalities.
+\fBstrace.C.sysent_vec\fR[\fIpers\fR][\fIscno\fR] is a
+.B struct_sysent
+for syscall number
+.I scno
+on personality
+.IR pers .
+May contain null entries (which have a NULL
+.B sys_name
+field).
+.TP
+.B strace.C.errnoent_vec
+Array of error name tables for each of the supported personalities.
+\fBstrace.C.errnoent_vec\fR[\fIpers\fR][\fIerrno\fR] is either a null pointer
or
+a C string with the name of error
+.I errno
+on personality
+.IR pers .
+.TP
+.B strace.C.signalent_vec
+Array of signal name tables for each of the supported personalities.
+\fBstrace.C.signalent_vec\fR[\fIpers\fR][\fIsigno\fR] is either a null pointer
+or a C string with the name of signal
+.I signo
+on personality
+.IR pers .
+.TP
+.B strace.C.ioctlent_vec
+Arrays of sorted known ioctl symbols, sorted by code, for each of the supported
+personalities.
+\fBstrace.C.ioctlent_vec\fR[\fIpers\fR][\fIi\fR] is the
+.IR i \-th,
+ranked by code,
+.B struct_ioctlent
+for personality
+.IR pers .
+.TP
+.B strace.C.nsysent_vec
+.TQ
+.B strace.C.nerrnoent_vec
+.TQ
+.B strace.C.nsignalent_vec
+.TQ
+.B strace.C.nioctlent_vec
+These are
+.BR strace.npersonalities \-sized
+arrays containing sizes of subarrays of
+.BR strace.C.sysent_vec ,
+.BR strace.C.errnoent_vec ,
+.BR strace.C.signalent_vec " and"
+.BR strace.C.ioctlent_vec ,
+respectively.
+.TP
+.B strace.C.syscall_classes
+Array of
+.BR "struct syscall_class" ,
+with a terminating null entry (which has a NULL
+.B name
+field).
+.TP
+.B strace.C.pers_name
+A
+.BR strace.npersonalities \-sized
+array of C strings with names for each personality.
+.TP
+.B strace.C.pers_wordsize
+.TQ
+.B strace.C.pers_klongsize
+These are
+.BR strace.npersonalities \-sized
+arrays with word and
+.I __kernel_long_t
+sizes for each personality.
+.SS strace module: functions
+Glossary:
+.RS
+.IP \(bu 3
+an
+.I integer
+means either an integer Lua number or a cdata integer type;
+.IP \(bu
+a
+.I boolean
+means either a Lua boolean or a cdata
+.BR bool ;
+.IP \(bu
+a
+.I string
+means either a Lua string or a cdata C string;
+.IP \(bu
+the
+.I current tracing control pointer
+is a pointer to the current trace control block.
+This pointer is obtained from
+.B strace.C.next_sc
+calls and provided to hook callback functions.
+These pointers are not persistent across .B strace.C.next_sc and/or hook calls.
+.RE
+.PP
+General conventions:
+.RS
+.IP \(bu 3
+a
+.I tcp
+argument is the
+.IR "current tracing control pointer" ;
+.IP \(bu
+a
+.I pers
+argument is an
+.I integer
+specifying personality number;
+.IP \(bu
+an
+.I addr
+argument is a cdata
+.IR kernel_ulong_t .
+.RE
+.TP
+\fIstatus\fR = \fBstrace.entering\fR(\fItcp\fR)
+Returns
+.B true
+if this is a syscall entry, and
+.B false
+otherwise.
+.TP
+\fIstatus\fR = \fBstrace.exiting\fR(\fItcp\fR)
+Returns
+.B true
+if this is a syscall exit, and
+.B false
+otherwise.
+.TP
+\fBstrace.trace\fR(\fItcp\fR[, \fIflag\fR])
+.TQ
+\fBstrace.abbrev\fR(\fItcp\fR[, \fIflag\fR])
+.TQ
+\fBstrace.verbose\fR(\fItcp\fR[, \fIflag\fR])
+.TQ
+\fBstrace.raw\fR(\fItcp\fR[, \fIflag\fR])
+These functions alter corresponding trace options.
+.I flag
+is a
+.IR boolean ,
+defaults to
+.BR true .
+.TP
+\fIaddr\fR = \fBstrace.ptr_to_kulong\fR(\fIptr\fR)
+Converts a cdata pointer to a
+.B kernel_ulong_t
+variable.
+.TP
+\fBstrace.at_exit\fR(\fIfunc\fR)
+Registers a function
+.I func
+to be run when
+.B strace
+is going to terminate its execution.
+.IP
+If multiple exit callback functions are registered, they are run in the order
+they were registered.
+.TP
+\fIname\fR = \fBstrace.get_sc_name\fR(\fIscno\fR, \fIpers\fR)
+Returns syscall name as Lua string by its number for personality
+.IR pers ,
+or
+.B nil
+if
+.I scno
+is invalid.
+.IP
+.I scno
+is an
+.IR integer .
+.TP
+\fIname\fR = \fBstrace.get_sig_name\fR(\fIsigno\fR, \fIpers\fR)
+Returns signal name (.e.g \fB"SIGSEGV"\fR) as Lua string by its number
+.I signo
+for personality
+.IR pers ,
+or
+.B nil
+if
+.I signo
+is invalid.
+.TP
+\fIname\fR = \fBstrace.get_err_name\fR(\fIerrno\fR, \fIpers\fR)
+Returns error name (e.g. \fB"ENOENT"\fR) as Lua string by its error number
+.I errno
+for personality
+.IR pers ,
+or
+.B nil
+if
+.I errno
+is invalid.
+.IP
+.I errno
+is an
+.IR integer .
+.TP
+\fIname\fR = \fBstrace.get_ioctl_name\fR(\fIreqcode\fR, \fIpers\fR)
+Returns ioctl symbol name (e.g. \fB"TIOCGWINSZ"\fR) as Lua string by its
request
+code
+.I reqcode
+for personality
+.IR pers ,
+or
+.B nil
+if
+.I reqcode
+is invalid.
+.IP
+.I reqcode
+is an
+.IR integer .
+.TP
+\fIscno\fR = \fBstrace.get_scno\fR(\fIscname\fR, \fIpers\fR)
+Returns syscall number by its name for personality
+.IR pers ,
+or
+.B nil
+if no such syscall was found.
+.IP
+.I scname
+is a
+.IR string .
+.TP
+\fIsigno\fR = \fBstrace.get_signo\fR(\fIsigname\fR, \fIpers\fR)
+Returns signal number by its name (e.g. \fB"SIGSEGV"\fR) for personality
+.IR pers ,
+or
+.B nil
+if no such signal was found.
+.IP
+.I signame
+is
+.IR string .
+.TP
+\fIerrno\fR = \fBstrace.get_errno\fR(\fIerrname\fR, \fIpers\fR)
+Returns error number by its name (e.g. \fB"ENOENT"\fR) for personality
+.IR pers ,
+or
+.B nil
+if no such error was found.
+.IP
+.I errname
+is a
+.IR string .
+.TP
+\fIcode\fR = \fBstrace.get_ioctl_code\fR(\fIname\fR, \fIpers\fR)
+Returns ioctl request code by its symbol name (e.g. \fB"TIOCGWINSZ"\fR) for
+personality
+.IR pers ,
+or
+.B nil
+if no such ioctl request was found.
+.IP
+.I name
+is a
+.IR string .
+.TP
+\fIstatus\fR = \fBstrace.inject_signal\fR(\fItcp\fR, \fIsig\fR)
+Delivers a signal to the tracee.
+.I sig
+is either signal number (an
+.IR integer )
+or name (a
+.IR string ).
+.IP
+Returns
+.B true
+on success and
+.B false
+on failure.
+.IP
+Note that this must be done on syscall entry.
+.TP
+\fIstatus\fR = \fBstrace.inject_error\fR(\fItcp\fR, \fIerr\fR)
+Injects an error into a current syscall invocation.
+.I err
+is either error number (an
+.IR integer )
+or error name (a
+.IR string ).
+.IP
+Returns
+.B true
+on success and
+.B false
+on failure.
+.IP
+Note that this must be done on syscall entry.
+.TP
+\fIobj\fR = \fBstrace.read_obj\fR(\fIaddr\fR, \fIct\fR[, \fInelem\fR])
+Reads an object of type
+.I ct
+from the current tracee process at address
+.IR addr .
+.I ct
+is either a
+.I cdecl
+(a Lua string), a
+.I cdata
+serving as a template type, or a
+.I ctype
+(special kind of
+.I cdata
+returned by
+.BR ffi.typeof ).
+.IP
+VLA/VLS types require the
+.I nelem
+argument (an
+.IR integer ).
+.IP
+Returns an object on success and
+.B nil
+on failure.
+.IP
+Note that type sizes and structure paddings may differ from FFI's ones if
+tracee's personality differs from
+.BR strace 's
+one.
+.TP
+\fIstr\fR[, \fIerr_msg\fR] = \fBstrace.read_str\fR(\fIaddr\fR[, \fImaxsz\fR[,
\fIbufsz\fR]])
+Reads a C string from the current tracee process at address
+.I addr
+using an intermediate buffer of size
+.I bufsz
+and stopping at
+.I maxsz
+bytes.
+.IP
+.I maxsz
+and
+.I bufsz
+are
+.IR integers .
+.I maxsz
+defaults to 4 Mb,
+.I bufsz
+to 1 Kb.
+.IP
+Returns a Lua string on success, \fBnil, "readerr"\fR on read error, and
+\fBnil, "toolong"\fR if the
+.I maxsz
+limit was exceeded.
+.TP
+\fIstr\fR[, \fIerr_msg\fR] = \fBstrace.read_path\fR(\fIaddr\fR)
+Reads a path C string from the current tracee process at address
+.IR addr .
+.IP
+Returns a Lua string on success, \fBnil, "readerr"\fR on read error, and
+\fBnil, "toolong"\fR if the
+.B PATH_MAX
+limit was exceeded.
+.TP
+\fIstatus\fR = \fBstrace.hook\fR(\fIscname\fR, \fIwhen\fR, \fIcb\fR)
+.TQ
+\fIstatus\fR = \fBstrace.hook_class\fR(\fIclsname\fR, \fIwhen\fR, \fIcb\fR)
+.TQ
+\fIstatus\fR = \fBstrace.hook_scno\fR(\fIscno\fR, \fIpers\fR, \fIwhen\fR,
\fIcb\fR)
+These functions register a function
+.I cb
+to be run when a syscall with the given name (or with a name from a given set
+thereof), belonging to a class with the given name (or with a name from a given
+set thereof), or with the given number (or with a number from a given set
+thereof) on personality
+.IR pers ,
+happens.
+.IP
+.I when
+is either a two-element array (that is, a table with keys 1 and 2) with boolean
+values, or a Lua string.
+.I cb
+is registered to be run:
+.RS
+.IP \(bu 3
+on syscall entry if
+.I when
+is either
+.B {true, false}
+or \fB"entering"\fR;
+.IP \(bu
+on syscall exit if
+.I when
+is either
+.B {false, true}
+or \fB"exiting"\fR;
+.IP \(bu
+both on syscall entry and exit if
+.I when
+is either
+.B {true, true}
+or \fB"both"\fR;
+.IP \(bu
+at no time if
+.I when
+is
+.B "{false, false}"
+(in this case, a call is effectively ignored).
+.RE
+.IP
+A pointer to the trace control block is passed as the only argument to
+.IR cb .
+.IP
+If multiple callback functions are registered for the same event (syscall entry
+or exit), they are run in the order they were registered.
+.IP
+.IR scname " and " clsname
+are either
+.I strings
+or tables thereof.
+.I scno
+is either an
+.I integer
+or a table thereof.
+.IP
+Return
+.B true
+on success and
+.B false
+on failure.
+.TP
+\fIstatus\fR = \fBstrace.path_match\fR(\fIset\fR)
+Returns
+.B true
+if the current syscall accesses a given path, or one of the paths from the
given
+set of paths; and
+.B false
+otherwise (see the note for
+.BR strace.C.path_match ).
+.IP
+.I set
+is either a
+.I string
+or a table thereof.
+.SS strace module: constants
+.TP
+.B strace.npersonalities
+Number of supported personalities (an integer Lua number).
+.TP
+.B strace.max_args
+Size of
+.B struct tcb::u_arg
+array (an integer Lua number).
+.TP
+.B strace.path_max
+Value of
+.B PATH_MAX
+constant (an integer Lua number).
+.SS Examples
+The following script counts the number of processes (including threads) spawned
+by the tracee.
+Note that you would probably want to launch
+.B strace
+with
+.B -f
+option, so that children also be traced.
+.CW
+n = 0
+assert(strace.hook({'clone', 'fork', 'vfork'}, 'exiting', function(tcp)
+ if tcp.u_rval ~= -1 then
+ n = n + 1
+ end
+end))
+strace.at_exit(function() print('Processes spawned:', n) end)
+.CE
+The following script uses the ffiex library (see the discussion in the
+.B FFI
+section) and injects the
+.B EPERM
+error to each
+.B fcntl
+(and
+.BR fcntl64 )
+syscall invocation with
+.B F_SETPIPE_SZ
+command.
+.CW
+ffiex = require 'ffiex'
+ffiex.cdef[[
+#define _GNU_SOURCE
+#include <fcntl.h>
+]]
+f_setpipe_sz = assert(tonumber(ffiex.defs.F_SETPIPE_SZ))
+assert(strace.hook({'fcntl', 'fcntl64'}, 'entering', function(tcp)
+ if tcp.u_arg[1] == f_setpipe_sz then
+ assert(strace.inject_error(tcp, 'EPERM'))
+ end
+end))
+.CE
.SH DIAGNOSTICS
When
.I command
diff --git a/strace.c b/strace.c
index 6ed86a6f..470b2768 100644
--- a/strace.c
+++ b/strace.c
@@ -45,6 +45,9 @@
# include <sys/prctl.h>
#endif
#include <asm/unistd.h>
+#ifdef USE_LUAJIT
+# include <lua.h>
+#endif
#include "number_set.h"
#include "scno.h"
@@ -170,6 +173,11 @@ static volatile sig_atomic_t interrupted;
static volatile int interrupted;
#endif
+#ifdef USE_LUAJIT
+static lua_State *script_L = NULL;
+static void init_luajit(const char *scriptfile);
+#endif
+
#ifndef HAVE_STRERROR
#if !HAVE_DECL_SYS_ERRLIST
@@ -228,6 +236,11 @@ Output format:\n\
-k obtain stack trace between each syscall (experimental)\n\
"
#endif
+#ifdef USE_LUAJIT
+"\
+ -l file run a Lua script from FILE\n\
+"
+#endif
"\
-o file send trace output to FILE instead of stderr\n\
-q suppress messages about attaching, detaching, etc.\n\
@@ -713,7 +726,7 @@ alloctcb(int pid)
if (!tcp->pid) {
memset(tcp, 0, sizeof(*tcp));
tcp->pid = pid;
-#if SUPPORTED_PERSONALITIES > 1
+#if defined(USE_LUAJIT) || SUPPORTED_PERSONALITIES > 1
tcp->currpers = current_personality;
#endif
@@ -1589,6 +1602,9 @@ init(int argc, char *argv[])
#ifdef USE_LIBUNWIND
"k"
#endif
+#ifdef USE_LUAJIT
+ "l:"
+#endif
"D"
"a:e:o:O:p:s:S:u:E:P:I:")) != EOF) {
switch (c) {
@@ -1699,6 +1715,11 @@ init(int argc, char *argv[])
stack_trace_enabled = true;
break;
#endif
+#ifdef USE_LUAJIT
+ case 'l':
+ init_luajit(optarg);
+ break;
+#endif
case 'E':
if (putenv(optarg) < 0)
perror_msg_and_die("putenv");
@@ -2216,6 +2237,9 @@ enum trace_event {
*/
TE_SYSCALL_STOP,
+ /* Syscall entry or exit, after hook. */
+ TE_SYSCALL_STOP_HOOK_EXIT,
+
/*
* Tracee received signal with number WSTOPSIG(*pstatus); signal info
* is written to *si. Restart the tracee (with that signal number
@@ -2406,24 +2430,47 @@ next_event(int *pstatus, siginfo_t *si)
}
}
+enum hook_state {
+ HOOK_ENTER,
+ HOOK_EXIT,
+ HOOK_IGNORE,
+};
+
static int
-trace_syscall(struct tcb *tcp, unsigned int *sig)
+trace_syscall(struct tcb *tcp, unsigned int *sig, enum hook_state state)
{
if (entering(tcp)) {
- int res = syscall_entering_decode(tcp);
- switch (res) {
- case 0:
- return 0;
- case 1:
+ int res;
+ switch (state) {
+ case HOOK_ENTER:
+ case HOOK_IGNORE:
+ res = syscall_entering_decode(tcp);
+ if (res == 0)
+ return 0;
+ if (res == 1)
+ if (state == HOOK_ENTER &&
+ (tcp->qual_flg & QUAL_HOOK_ENTRY))
+ return RVAL_HOOKED;
+ /* Fall through */
+ case HOOK_EXIT:
res = syscall_entering_trace(tcp, sig);
}
syscall_entering_finish(tcp, res);
return res;
} else {
- struct timeval tv = {};
- int res = syscall_exiting_decode(tcp, &tv);
- if (res != 0) {
- res = syscall_exiting_trace(tcp, tv, res);
+ static struct timeval tv;
+ int res = 1;
+ switch (state) {
+ case HOOK_ENTER:
+ case HOOK_IGNORE:
+ res = syscall_exiting_decode(tcp, &tv);
+ if (res == 1 && state == HOOK_ENTER &&
+ (tcp->qual_flg & QUAL_HOOK_EXIT))
+ return RVAL_HOOKED;
+ /* Fall through */
+ case HOOK_EXIT:
+ if (res != 0)
+ res = syscall_exiting_trace(tcp, tv, res);
}
syscall_exiting_finish(tcp);
return res;
@@ -2432,10 +2479,11 @@ trace_syscall(struct tcb *tcp, unsigned int *sig)
/* Returns true iff the main trace loop has to continue. */
static bool
-dispatch_event(enum trace_event ret, int *pstatus, siginfo_t *si)
+dispatch_event(enum trace_event ret, int *pstatus, siginfo_t *si, bool hooked)
{
unsigned int restart_op = PTRACE_SYSCALL;
unsigned int restart_sig = 0;
+ int res;
switch (ret) {
case TE_BREAK:
@@ -2448,7 +2496,17 @@ dispatch_event(enum trace_event ret, int *pstatus,
siginfo_t *si)
break;
case TE_SYSCALL_STOP:
- if (trace_syscall(current_tcp, &restart_sig) < 0) {
+ case TE_SYSCALL_STOP_HOOK_EXIT:
+ res = trace_syscall(current_tcp, &restart_sig,
+ hooked ? (ret == TE_SYSCALL_STOP ? HOOK_ENTER :
HOOK_EXIT) :
+ HOOK_IGNORE);
+
+ if (res == RVAL_HOOKED) {
+ current_tcp->flags |= TCB_HOOK;
+ return true;
+ }
+
+ if (res < 0) {
/*
* ptrace() failed in trace_syscall().
* Likely a result of process disappearing mid-flight.
@@ -2584,6 +2642,10 @@ terminate(void)
exit(exit_code);
}
+#ifdef USE_LUAJIT
+# include "luajit.h"
+#endif
+
int
main(int argc, char *argv[])
{
@@ -2591,9 +2653,14 @@ main(int argc, char *argv[])
exit_code = !nprocs;
+#ifdef USE_LUAJIT
+ if (script_L)
+ run_luajit();
+#endif
+
int status;
siginfo_t si;
- while (dispatch_event(next_event(&status, &si), &status, &si))
+ while (dispatch_event(next_event(&status, &si), &status, &si, false))
;
terminate();
}
diff --git a/syscall.c b/syscall.c
index d5aeabf0..d4dc06ed 100644
--- a/syscall.c
+++ b/syscall.c
@@ -160,6 +160,16 @@ enum {
#endif
};
+const char *const *errnoent_vec[SUPPORTED_PERSONALITIES] = {
+ errnoent0,
+#if SUPPORTED_PERSONALITIES > 1
+ errnoent1,
+# if SUPPORTED_PERSONALITIES > 2
+ errnoent2,
+# endif
+#endif
+};
+
enum {
nerrnos0 = ARRAY_SIZE(errnoent0)
#if SUPPORTED_PERSONALITIES > 1
@@ -170,6 +180,16 @@ enum {
#endif
};
+const unsigned int nerrnoent_vec[] = {
+ nerrnos0,
+#if SUPPORTED_PERSONALITIES > 1
+ nerrnos1,
+# if SUPPORTED_PERSONALITIES > 2
+ nerrnos2,
+# endif
+#endif
+};
+
enum {
nsignals0 = ARRAY_SIZE(signalent0)
#if SUPPORTED_PERSONALITIES > 1
@@ -180,6 +200,26 @@ enum {
#endif
};
+const char *const *signalent_vec[SUPPORTED_PERSONALITIES] = {
+ signalent0,
+#if SUPPORTED_PERSONALITIES > 1
+ signalent1,
+# if SUPPORTED_PERSONALITIES > 2
+ signalent2,
+# endif
+#endif
+};
+
+const unsigned int nsignalent_vec[] = {
+ nsignals0,
+#if SUPPORTED_PERSONALITIES > 1
+ nsignals1,
+# if SUPPORTED_PERSONALITIES > 2
+ nsignals2,
+# endif
+#endif
+};
+
enum {
nioctlents0 = ARRAY_SIZE(ioctlent0)
#if SUPPORTED_PERSONALITIES > 1
@@ -190,6 +230,26 @@ enum {
#endif
};
+const unsigned int nioctlent_vec[] = {
+ nioctlents0,
+#if SUPPORTED_PERSONALITIES > 1
+ nioctlents1,
+# if SUPPORTED_PERSONALITIES > 2
+ nioctlents2,
+# endif
+#endif
+};
+
+const struct_ioctlent *const ioctlent_vec[SUPPORTED_PERSONALITIES] = {
+ ioctlent0,
+#if SUPPORTED_PERSONALITIES > 1
+ ioctlent1,
+# if SUPPORTED_PERSONALITIES > 2
+ ioctlent2,
+# endif
+#endif
+};
+
#if SUPPORTED_PERSONALITIES > 1
const struct_sysent *sysent = sysent0;
const char *const *errnoent = errnoent0;
@@ -222,29 +282,55 @@ const struct_sysent *const
sysent_vec[SUPPORTED_PERSONALITIES] = {
#endif
};
+const int personality_wordsize[SUPPORTED_PERSONALITIES] = {
+ PERSONALITY0_WORDSIZE,
+#if SUPPORTED_PERSONALITIES > 1
+ PERSONALITY1_WORDSIZE,
+#endif
+#if SUPPORTED_PERSONALITIES > 2
+ PERSONALITY2_WORDSIZE,
+#endif
+};
+
+const int personality_klongsize[SUPPORTED_PERSONALITIES] = {
+ PERSONALITY0_KLONGSIZE,
#if SUPPORTED_PERSONALITIES > 1
+ PERSONALITY1_KLONGSIZE,
+#endif
+#if SUPPORTED_PERSONALITIES > 2
+ PERSONALITY2_KLONGSIZE,
+#endif
+};
+
+#if SUPPORTED_PERSONALITIES > 1
+
+const char *const personality_names[] =
+# if defined POWERPC64
+ {"64 bit", "32 bit"}
+# elif defined X86_64
+ {"64 bit", "32 bit", "x32"}
+# elif defined X32
+ {"x32", "32 bit"}
+# elif defined AARCH64
+ {"64 bit", "32 bit"}
+# elif defined TILE
+ {"64-bit", "32-bit"}
+# else
+# error Add personality names for your achitecture.
+# endif
+ ;
+
unsigned current_personality;
# ifndef current_wordsize
unsigned current_wordsize;
-static const int personality_wordsize[SUPPORTED_PERSONALITIES] = {
- PERSONALITY0_WORDSIZE,
- PERSONALITY1_WORDSIZE,
-# if SUPPORTED_PERSONALITIES > 2
- PERSONALITY2_WORDSIZE,
# endif
-};
+# ifndef current_klongsize
+unsigned current_klongsize;
# endif
# ifndef current_klongsize
unsigned current_klongsize;
-static const int personality_klongsize[SUPPORTED_PERSONALITIES] = {
- PERSONALITY0_KLONGSIZE,
- PERSONALITY1_KLONGSIZE,
-# if SUPPORTED_PERSONALITIES > 2
- PERSONALITY2_KLONGSIZE,
-# endif
-};
# endif
void
@@ -307,25 +393,10 @@ update_personality(struct tcb *tcp, unsigned int
personality)
return;
tcp->currpers = personality;
-# undef PERSONALITY_NAMES
-# if defined POWERPC64
-# define PERSONALITY_NAMES {"64 bit", "32 bit"}
-# elif defined X86_64
-# define PERSONALITY_NAMES {"64 bit", "32 bit", "x32"}
-# elif defined X32
-# define PERSONALITY_NAMES {"x32", "32 bit"}
-# elif defined AARCH64
-# define PERSONALITY_NAMES {"64 bit", "32 bit"}
-# elif defined TILE
-# define PERSONALITY_NAMES {"64-bit", "32-bit"}
-# endif
-# ifdef PERSONALITY_NAMES
if (!qflag) {
- static const char *const names[] = PERSONALITY_NAMES;
error_msg("[ Process PID=%d runs in %s mode. ]",
- tcp->pid, names[personality]);
+ tcp->pid, personality_names[personality]);
}
-# endif
}
#endif
@@ -543,40 +614,55 @@ static int arch_set_success(struct tcb *);
struct inject_opts *inject_vec[SUPPORTED_PERSONALITIES];
-static struct inject_opts *
-tcb_inject_opts(struct tcb *tcp)
+static struct inject_values
+tcb_inject_values(struct tcb *tcp, bool step)
{
- return (scno_in_range(tcp->scno) &&
tcp->inject_vec[current_personality])
- ? &tcp->inject_vec[current_personality][tcp->scno] : NULL;
-}
-
-
-static long
-tamper_with_syscall_entering(struct tcb *tcp, unsigned int *signo)
-{
- if (!tcp->inject_vec[current_personality]) {
+ if (step && !tcp->inject_vec[current_personality] &&
+ inject_vec[current_personality]) {
tcp->inject_vec[current_personality] =
xcalloc(nsyscalls, sizeof(**inject_vec));
memcpy(tcp->inject_vec[current_personality],
inject_vec[current_personality],
nsyscalls * sizeof(**inject_vec));
}
+ struct inject_opts *opts =
+ scno_in_range(tcp->scno) && tcp->inject_vec[current_personality]
+ ? &tcp->inject_vec[current_personality][tcp->scno] : NULL;
+ struct inject_values res = {
+ .rval = INJECT_VALS_RVAL_DEFAULT,
+ .signo = 0,
+ };
+ if (opts) {
+ if (step) {
+ if (opts->first != 0 && --opts->first == 0) {
+ res = opts->vals;
+ opts->first = opts->step;
+ }
+ } else {
+ res = opts->vals;
+ }
+ }
+#ifdef USE_LUAJIT
+ if (tcp->flags & TCB_AD_HOC_INJECT) {
+ struct inject_values ad_hoc_vals = tcp->ad_hoc_inject_vals;
+ if (ad_hoc_vals.rval != INJECT_VALS_RVAL_DEFAULT)
+ res.rval = ad_hoc_vals.rval;
+ if (ad_hoc_vals.signo > 0)
+ res.signo = ad_hoc_vals.signo;
+ }
+#endif
+ return res;
+}
- struct inject_opts *opts = tcb_inject_opts(tcp);
-
- if (!opts || opts->first == 0)
- return 0;
-
- --opts->first;
-
- if (opts->first != 0)
- return 0;
- opts->first = opts->step;
+static long
+tamper_with_syscall_entering(struct tcb *tcp, unsigned int *signo)
+{
+ struct inject_values vals = tcb_inject_values(tcp, true);
- if (opts->signo > 0)
- *signo = opts->signo;
- if (opts->rval != INJECT_OPTS_RVAL_DEFAULT && !arch_set_scno(tcp, -1))
+ if (vals.signo > 0)
+ *signo = vals.signo;
+ if (vals.rval != INJECT_VALS_RVAL_DEFAULT && !arch_set_scno(tcp, -1))
tcp->flags |= TCB_TAMPERED;
return 0;
@@ -585,22 +671,22 @@ tamper_with_syscall_entering(struct tcb *tcp, unsigned
int *signo)
static long
tamper_with_syscall_exiting(struct tcb *tcp)
{
- struct inject_opts *opts = tcb_inject_opts(tcp);
+ struct inject_values vals = tcb_inject_values(tcp, false);
- if (!opts)
+ if (vals.rval == INJECT_VALS_RVAL_DEFAULT)
return 0;
- if (opts->rval >= 0) {
+ if (vals.rval >= 0) {
kernel_long_t u_rval = tcp->u_rval;
- tcp->u_rval = opts->rval;
+ tcp->u_rval = vals.rval;
if (arch_set_success(tcp)) {
tcp->u_rval = u_rval;
} else {
tcp->u_error = 0;
}
} else {
- unsigned long new_error = -opts->rval;
+ unsigned long new_error = -vals.rval;
if (new_error != tcp->u_error && new_error <= MAX_ERRNO_VALUE) {
unsigned long u_error = tcp->u_error;
@@ -663,6 +749,12 @@ syscall_entering_decode(struct tcb *tcp)
return 1;
}
+static bool
+syscall_ad_hoc_injected(struct tcb *tcp)
+{
+ return (tcp->qual_flg & QUAL_INJECT) && (tcp->flags &
TCB_AD_HOC_INJECT);
+}
+
int
syscall_entering_trace(struct tcb *tcp, unsigned int *sig)
{
@@ -685,13 +777,13 @@ syscall_entering_trace(struct tcb *tcp, unsigned int *sig)
|| (tracing_paths && !pathtrace_match(tcp))
) {
tcp->flags |= TCB_FILTERED;
- return 0;
+ goto maybe_ad_hoc_tamper;
}
tcp->flags &= ~TCB_FILTERED;
if (hide_log(tcp)) {
- return 0;
+ goto maybe_ad_hoc_tamper;
}
if (tcp->qual_flg & QUAL_INJECT)
@@ -714,6 +806,11 @@ syscall_entering_trace(struct tcb *tcp, unsigned int *sig)
? printargs(tcp) : tcp->s_ent->sys_func(tcp);
fflush(tcp->outf);
return res;
+
+maybe_ad_hoc_tamper:
+ if (syscall_ad_hoc_injected(tcp))
+ tamper_with_syscall_entering(tcp, sig);
+ return 0;
}
void
@@ -754,21 +851,28 @@ syscall_exiting_decode(struct tcb *tcp, struct timeval
*ptv)
}
#endif
- if (filtered(tcp) || hide_log(tcp))
+ if ((filtered(tcp) || hide_log(tcp))
+ && !(tcp->qual_flg & QUAL_HOOK_EXIT) && !syscall_ad_hoc_injected(tcp))
return 0;
get_regs(tcp->pid);
#if SUPPORTED_PERSONALITIES > 1
update_personality(tcp, tcp->currpers);
#endif
- return get_regs_error ? -1 : get_syscall_result(tcp);
+ if (get_regs_error || get_syscall_result(tcp) == -1)
+ return -1;
+
+ if (syserror(tcp) && syscall_tampered(tcp))
+ tamper_with_syscall_exiting(tcp);
+
+ return 1;
}
int
syscall_exiting_trace(struct tcb *tcp, struct timeval tv, int res)
{
- if (syserror(tcp) && syscall_tampered(tcp))
- tamper_with_syscall_exiting(tcp);
+ if (filtered(tcp) || hide_log(tcp))
+ return 0;
if (cflag) {
count_syscall(tcp, &tv);
@@ -977,7 +1081,7 @@ syscall_exiting_trace(struct tcb *tcp, struct timeval tv,
int res)
void
syscall_exiting_finish(struct tcb *tcp)
{
- tcp->flags &= ~(TCB_INSYSCALL | TCB_TAMPERED);
+ tcp->flags &= ~(TCB_INSYSCALL | TCB_TAMPERED | TCB_AD_HOC_INJECT);
tcp->sys_func_rval = 0;
free_tcb_priv_data(tcp);
}
diff --git a/sysent.h b/sysent.h
index 92de7468..15b83693 100644
--- a/sysent.h
+++ b/sysent.h
@@ -1,13 +1,31 @@
-#ifndef STRACE_SYSENT_H
-#define STRACE_SYSENT_H
+#if !defined(STRACE_SYSENT_H) || defined(FFI_CDEF)
+#ifndef FFI_CDEF
+# define STRACE_SYSENT_H
+#endif
+#include "ffi.h"
+
+FFI_CONTENT(
typedef struct sysent {
unsigned nargs;
int sys_flags;
+)
+/* We don't want to expose sen and sys_func to LuaJIT */
+#ifdef FFI_CDEF
+FFI_CONTENT(
+ int priv1;
+ void *priv2;
+)
+#else
+FFI_CONTENT(
int sen;
int (*sys_func)();
+)
+#endif
+FFI_CONTENT(
const char *sys_name;
} struct_sysent;
+)
#define TRACE_FILE 00000001 /* Trace file-related
syscalls. */
#define TRACE_IPC 00000002 /* Trace IPC-related
syscalls. */
@@ -29,4 +47,4 @@ typedef struct sysent {
#define TRACE_FSTAT 00400000 /* Trace
*fstat{,at}{,64} syscalls. */
#define TRACE_STAT_LIKE 01000000 /* Trace
*{,l,f}stat{,x,at}{,64} syscalls. */
-#endif /* !STRACE_SYSENT_H */
+#endif /* !defined(STRACE_SYSENT_H) || defined(FFI_CDEF) */
--
2.11.0
------------------------------------------------------------------------------
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