New feature was added: changing a function's return value by the resu…

…lt of corresponding wrapper-function written in python language. Function's parameters will be passed to the wrapper according to the definition in ltrace config file. Use "-M" option to use the feature (i386 & x86_64).

New feature was added: the quick time machine. Now it is possible to simulate time tracing the program. Use "-q" option followed by the timestamp. The time will go forward starting from that (i386 & x86_64).

New feature was added: fast return value patching. Use "-m" option to patch a function's return value. Only integers are supported by now (i386 & x86_64)

New argument type was added: "binary". It's the same as "string", but it is not limited by the first zero character.

Makefile.am

@@ -22,6 +22,7 @@ libltrace_la_SOURCES = \
 	libltrace.c \
 	options.c \
 	output.c \
+	mock.c \
 	proc.c \
 	read_config_file.c  \
 	summary.c
@@ -61,6 +62,8 @@ noinst_HEADERS = \
 dist_man1_MANS = \
 	ltrace.1
 
+docdir = ${datadir}/doc/${PACKAGE}
+
 dist_doc_DATA = \
 	COPYING \
 	README \

breakpoints.c

@@ -194,6 +194,11 @@ breakpoints_init(Process *proc) {
 					}
 					tmp2 = tmp2->next;
 				}
+
+				if (opt_q && !keep && (!strcmp((*tmp1)->name, "time") || !strcmp((*tmp1)->name, "gettimeofday") || !strcmp((*tmp1)->name, "clock_gettime"))) {
+					keep = 1;
+				}
+
 				if (!keep) {
 					*tmp1 = (*tmp1)->next;
 				} else {

common.h

@@ -25,6 +25,8 @@ extern char * command;
 
 extern int exiting;  /* =1 if we have to exit ASAP */
 
+extern int opt_fake_return;
+
 typedef struct Breakpoint Breakpoint;
 struct Breakpoint {
 	void * addr;
@@ -54,6 +56,8 @@ enum arg_type {
 	ARGTYPE_FORMAT,		/* printf-like format */
 	ARGTYPE_STRING,		/* NUL-terminated string */
 	ARGTYPE_STRING_N,	/* String of known maxlen */
+	ARGTYPE_BYTES,		/* Array of bytes */
+	ARGTYPE_BYTES_N,	/* Binary data of known maxlen */
 	ARGTYPE_ARRAY,		/* Series of values in memory */
 	ARGTYPE_ENUM,		/* Enumeration */
 	ARGTYPE_STRUCT,		/* Structure of values */
@@ -213,6 +217,7 @@ struct opt_c_struct {
 
 #include "options.h"
 #include "output.h"
+#include "mock.h"
 #ifdef USE_DEMANGLE
 #include "demangle.h"
 #endif
@@ -226,6 +231,7 @@ extern Process * pid2proc(pid_t pid);
 extern void handle_event(Event * event);
 extern void execute_program(Process *, char **);
 extern int display_arg(enum tof type, Process * proc, int arg_num, arg_type_info * info);
+extern long get_length(enum tof type, Process *proc, int len_spec, void *st, arg_type_info* st_info);
 extern Breakpoint * address2bpstruct(Process * proc, void * addr);
 extern void breakpoints_init(Process * proc);
 extern void insert_breakpoint(Process * proc, void * addr, struct library_symbol * libsym);
@@ -254,6 +260,7 @@ extern void trace_me(void);
 extern int trace_pid(pid_t pid);
 extern void untrace_pid(pid_t pid);
 extern void get_arch_dep(Process * proc);
+extern void set_arch_dep(Process * proc);
 extern void * get_instruction_pointer(Process * proc);
 extern void set_instruction_pointer(Process * proc, void * addr);
 extern void * get_stack_pointer(Process * proc);
@@ -267,10 +274,12 @@ extern void continue_after_signal(pid_t pid, int signum);
 extern void continue_after_breakpoint(Process * proc, Breakpoint * sbp);
 extern void continue_enabling_breakpoint(pid_t pid, Breakpoint * sbp);
 extern long gimme_arg(enum tof type, Process * proc, int arg_num, arg_type_info * info);
+extern void set_arg(enum tof type, Process * proc, int arg_num, arg_type_info * info, long value);
 extern void save_register_args(enum tof type, Process * proc);
 extern int umovestr(Process * proc, void * addr, int len, void * laddr);
 extern int umovelong (Process * proc, void * addr, long * result, arg_type_info * info);
 extern size_t umovebytes (Process *proc, void * addr, void * laddr, size_t count);
+extern size_t uunmovebytes (Process *proc, void * addr, void * laddr, size_t count);
 extern int ffcheck(void * maddr);
 extern void * sym2addr(Process *, struct library_symbol *);
 extern int linkmap_init(Process *, struct ltelf *);

configure.ac

@@ -1,3 +1,5 @@
+m4_include([m4/as-python.m4])
+
 # -*- Autoconf -*-
 # Process this file with autoconf to produce a configure script.
 AC_PREREQ(2.59)
@@ -65,6 +67,14 @@ AC_CHECK_LIB([elf], [elf_begin],,
 CPPFLAGS="${saved_CPPFLAGS}"
 LDFLAGS="${saved_LDFLAGS}"
 
+#Python
+AS_PATH_PYTHON([2.6.0])
+AM_CHECK_PYTHON_HEADERS([AM_CPPFLAGS="$AM_CPPFLAGS $PYTHON_INCLUDES"],[AC_MSG_NOTICE([could not find Python headers])])
+AM_CHECK_PYTHON_LIBS(
+	[
+		AC_DEFINE([HAVE_PYTHON], [1], [we have python])
+		AM_LDFLAGS="${AM_LDFLAGS} $PYTHON_LIBS"
+	],[AC_MSG_NOTICE([could not find Python libs])])
 
 # HAVE_LIBIBERTY
 AC_CHECK_LIB([iberty], [cplus_demangle], [
@@ -109,7 +119,7 @@ case "${enable_libunwind}" in
     enable_libunwind=no
   else
     AC_MSG_RESULT([$enable_libunwind])
-    AC_MSG_ERROR([libunwind.h or libunwind-ptrace.h cannot be found])	
+    AC_MSG_ERROR([libunwind.h or libunwind-ptrace.h cannot be found])
   fi
   ;;
 (*) ;;
@@ -244,6 +254,8 @@ if test x$enable_werror = xyes; then
     AM_CFLAGS="${AM_CFLAGS} -Werror"
 fi
 
+AM_LDFLAGS="${AM_LDFLAGS} -lrt"
+
 AC_SUBST(AM_CPPFLAGS)
 AC_SUBST(AM_CFLAGS)
 AC_SUBST(AM_LDFLAGS)

display_args.c

@@ -18,7 +18,7 @@ static int display_format(enum tof type, Process *proc, int arg_num);
 static size_t string_maxlength = INT_MAX;
 static size_t array_maxlength = INT_MAX;
 
-static long
+long
 get_length(enum tof type, Process *proc, int len_spec,
 		       void *st, arg_type_info* st_info) {
 	long len;
@@ -216,9 +216,11 @@ display_value(enum tof type, Process *proc,
 		fprintf(stderr, "Should never encounter a format anywhere but at the top level (for now?)\n");
 		exit(1);
 	case ARGTYPE_STRING:
+	case ARGTYPE_BYTES:
 		return display_string(type, proc, (void*) value,
 				      string_maxlength);
 	case ARGTYPE_STRING_N:
+	case ARGTYPE_BYTES_N:
 		return display_string(type, proc, (void*) value,
 				      get_length(type, proc,
 						 info->u.string_n_info.size_spec, st, st_info));

etc/ltrace.conf

@@ -25,6 +25,12 @@
 ; string[retval] == (char *)			[show only up to (return val) bytes]
 ; string[arg0]	== (char *)			[same as string[retval]]
 ; string[N]     == (char *)             [N>0]   [show only up to N bytes]
+; binary	== (char *)
+; binary[argN]  == (char *)		[N>0]	[show only up to (arg N) bytes]
+; binary[eltN]  == (char *)		[N>0]	[show only up to (elt N) bytes]
+; binary[retval] == (char *)			[show only up to (return val) bytes]
+; binary[arg0]	== (char *)			[same as string[retval]]
+; binary[N]     == (char *)             [N>0]   [show only up to N bytes]
 ; type*		== (type *)			[pointer to any other type]
 ; enum (key=value,key=value,...)		[enumeration, see below]
 ; array(type,argN)
@@ -38,6 +44,8 @@
 ; Backwards-compatibility:
 ; string0	== (char *)			[same as string[retval]]
 ; stringN	== (char *)		[N>0]	[same as string[argN]]
+; binary0	== (char *)			[same as binary[retval]]
+; binaryN	== (char *)		[N>0]	[same as binary[argN]]
 
 
 
@@ -378,6 +386,7 @@ int tcsetattr(int,int,addr);
 ; time.h
 string ctime(addr);
 int gettimeofday(addr, addr);
+int clock_gettime(enum(CLOCK_REALTIME=0,CLOCK_MONOTONIC=1,CLOCK_PROCESS_CPUTIME_ID=2,CLOCK_THREAD_CPUTIME_ID=3,CLOCK_REALTIME_HR=4,CLOCK_MONOTONIC_HR=5),struct(int, long)*);
 addr gmtime(addr);
 addr localtime(addr);
 ulong strftime(+string2,ulong,string,addr);
@@ -429,7 +438,7 @@ int truncate(string,ulong);
 string ttyname(int);
 int unlink(string);
 void usleep(uint);
-long write(int, string3, ulong);
+long write(int, bytes3, ulong);
 addr sbrk(long);
 int getpagesize(void);
 long lseek(int,long,int);

handle_event.c

@@ -605,6 +605,8 @@ handle_breakpoint(Event *event) {
 			}
 			event->proc->return_addr = event->e_un.brk_addr;
 			if (event->proc->state != STATE_IGNORED) {
+				mock_return(LT_TOF_FUNCTIONR, event->proc,
+						event->proc->callstack[i].c_un.libfunc->name);
 				output_right(LT_TOF_FUNCTIONR, event->proc,
 						event->proc->callstack[i].c_un.libfunc->name);
 			}

libltrace.c

@@ -9,6 +9,10 @@
 #include <signal.h>
 #include <sys/wait.h>
 
+#ifdef HAVE_PYTHON
+#include "Python.h"
+#endif
+
 #include "common.h"
 
 char *command = NULL;
@@ -68,12 +72,19 @@ normal_exit(void) {
 		fclose(options.output);
 		options.output = NULL;
 	}
+#ifdef HAVE_PYTHON
+	Py_Finalize();
+#endif
 }
 
 void
 ltrace_init(int argc, char **argv) {
 	struct opt_p_t *opt_p_tmp;
 
+#ifdef HAVE_PYTHON
+	Py_Initialize();
+#endif
+
 	atexit(normal_exit);
 	signal(SIGINT, signal_exit);	/* Detach processes when interrupted */
 	signal(SIGTERM, signal_exit);	/*  ... or killed */
@@ -130,7 +141,7 @@ static void
 dispatch_callbacks(Event * ev) {
 	int i;
 	/* Ignoring case 1: signal into a dying tracer */
-	if (ev->type==EVENT_SIGNAL && 
+	if (ev->type==EVENT_SIGNAL &&
 			exiting && ev->e_un.signum == SIGSTOP) {
 		return;
 	}