Finished API and implementation

needs more documentation though


temp


wtf just happened


informative commit message


woa

MiniBug/api.h

@@ -0,0 +1,40 @@
+#include <stdint.h>
+
+#define __MSG_SIZE__            0x40
+#define __REQ_SIZE__            0x10
+
+typedef struct MESSAGE
+{
+    char str[64];
+}MESSAGE;
+
+typedef struct REQUEST
+{
+    uint64_t control;
+    uint64_t value;
+}REQUEST;
+
+// careful with stack alignment 
+// https://stackoverflow.com/a/5435890/8114293 
+// #define __REQ_SIZE__ sizeof(struct REQUEST)
+
+// REQUESTS
+
+// control
+
+#define     __EOF__             0x00
+#define     __REQ_REP__         0x01
+#define     __CMD__             0x02
+#define     __RECEIVED__        0x03
+#define     __DATA_SIZE__       0x04
+#define     __VALUE__           0x05
+#define     __UNRECOGN__        0x06   
+
+// value
+
+#define     __ANY__             0x00
+#define     __EXIT__            0x01
+
+#define     __PEEK_REG__        0x11
+
+#define     __NEXT_SYSCALL__    0x21    // TODO

MiniBug/assertion.c

@@ -0,0 +1,18 @@
+#include "assertion.h"
+
+void __assertion_failed__(char *file, int line, char *msg, int do_exit)
+{
+    fprintf(stderr, "ASSERT%s: %s : %i\n", do_exit ? "  " : "(soft)", file, line);
+    if(msg) fprintf(stderr, "MESSAGE%s: %s\n", do_exit ? " " : "     ", msg);
+    if(do_exit) exit(EXIT_FAILURE);
+}
+
+void print_bytes(void *ptr, int size)
+{
+    unsigned char *p = ptr;
+    int i;
+    for (i=0; i<size; i++) {
+        printf("0x%02hhX ", p[i]);
+    }
+    printf("\n");
+}

MiniBug/assertion.h

@@ -0,0 +1,12 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+#define assert(expr, msg) \
+    if (!(expr)) \
+        __assertion_failed__(__FILE__, __LINE__, msg, 1)
+
+#define assert_soft(expr, msg) if(!(expr))__assertion_failed__(__FILE__,__LINE__,msg,0)
+
+void __assertion_failed__(char *file, int line, char *msg, int do_exit);
+
+void print_bytes(void *ptr, int size);

MiniBug/functions.c

@@ -0,0 +1,21 @@
+#include "functions.h"
+
+void peek_reg(pid_t pid, int fd)
+{
+    int err;
+    REQUEST req;
+    req.control = __RECEIVED__;
+    req.value = __ANY__;
+    write(fd, &req, __REQ_SIZE__);
+
+    err = read(fd, &req, __REQ_SIZE__);
+    assert(err == __REQ_SIZE__, "");
+
+    int rax = ptrace(PTRACE_PEEKUSER, pid, req.value, NULL);
+
+    req.control = __VALUE__;
+    req.value = rax;
+    write(fd, &req, __REQ_SIZE__);
+
+    printf("> Peek Reg\n");
+}

MiniBug/functions.h

@@ -0,0 +1,13 @@
+/*
+*   Functions
+*   
+*   every function has the same signature (apart from the name).
+*
+*   void FUNCTION_NAME(pid_t pid, int fd);
+*
+*/
+
+#include "api.h"
+#include "khh.h"
+
+void peek_reg(pid_t pid, int fd);

MiniBug/khh.h

@@ -20,34 +20,39 @@
 // misc
 #include <string.h>
 #include <sys/wait.h>       // waitpid
+#include <signal.h>
 
 // defines
 #define __PORT__ 4711
 #define __SOCKET_PATH__ "tmp_sock"
-#define __MSG_SIZE__ 64
 
-/* assert
-
-Assertions
-
-void assert(expr, char* msg);
-void assert_soft(expr, char* msg);
-
-assert() checks `expr`, if the expression is `false` assert() will produce output on the stderr, including `msg`.
-assert() will then exit the program with `EXIT_FAILURE`, assert_soft() will only produce the warning.
-
-Attention: side effects in assert() will take place, e.g. `assert(++i == 0, "");` will increment i regardless of check.
-
-*/
-#define assert(expr, msg) \
-    if (!(expr)) \
-        __assertion_failed__(__FILE__, __LINE__, msg, 1)
-
-#define assert_soft(expr, msg) if(!(expr))__assertion_failed__(__FILE__,__LINE__,msg,0)
-
-void __assertion_failed__(char* file, int line, char* msg, int do_exit)
-{
-    fprintf(stderr,         "ASSERT%s: %s : %i\n", do_exit?"  ":"(soft)", file, line);
-    if(msg) fprintf(stderr, "MESSAGE%s: %s\n", do_exit?" ":"     ",msg);
-    if(do_exit) exit(EXIT_FAILURE);
-}
+#include "assertion.h"
+
+// registers
+# define R15	    8*00
+# define R14	    8*01
+# define R13	    8*02
+# define R12	    8*03
+# define RBP	    8*04
+# define RBX	    8*05
+# define R11	    8*06
+# define R10	    8*07
+# define R9	        8*08
+# define R8	        8*09
+# define RAX	    8*10
+# define RCX	    8*11
+# define RDX	    8*12
+# define RSI	    8*13
+# define RDI	    8*14
+# define ORIG_RAX   8*15
+# define RIP	    8*16
+# define CS	        8*17
+# define EFLAGS	    8*18
+# define RSP	    8*19
+# define SS	        8*20
+# define FS_BASE    8*21
+# define GS_BASE    8*22
+# define DS	        8*23
+# define ES	        8*24
+# define FS	        8*25
+# define GS	        8*26

MiniBug/makefile

@@ -9,23 +9,22 @@ DEPS := $(wildcard *.h)
 
 dir_exists: | $(DIR)
 
-%.o: %.c
-	@gcc -c -o $(DIR)$@ $^ $(CFLAGS) $(LIBS)
+$(DIR)%.o: %.c
+	@gcc -c -o $@ $^ $(CFLAGS) $(LIBS)
 
-compile_mdb: mdb.o
-	@gcc -o $(DIR)mdb $(DIR)$^ $(CFLAGS) $(LIBS)
+# todo: OBJECTS PATSUBST
+compile_mdb: $(DIR)mdb.o $(DIR)functions.o $(DIR)assertion.o
+	@gcc -o $(DIR)mdb $^ $(CFLAGS) $(LIBS)
 
-compile_mview: mview.o
-	@gcc -o $(DIR)mview $(DIR)$^ $(CFLAGS) $(LIBS)
+compile_mview: $(DIR)mview.o $(DIR)assertion.o
+	@gcc -o $(DIR)mview $^ $(CFLAGS) $(LIBS)
 
 clean: | compile_all
 	@rm -r -f $(DIR)
 
 mdb: | compile_mdb
 	@./$(DIR)mdb
 
-# @rm tmp_sock	# existence of tmp_sock creates problems with binding a berkeley socket
-
 mview: | compile_mview
 	@./$(DIR)mview
 

MiniBug/mdb.c

@@ -1,29 +1,72 @@
 #include "mdb.h"
 
+/*  could be useful
+*
+*   void checked_read(int fd, char* buf) { assert((int) read(fd, buf, __MSG_SIZE__)) == __MSG_SIZE__, "read unsuccessful"); }
+*
+*   or a macro?
+*
+*   #define checked_read(fd,buf) err=(int)read(fd,buf,__MSG_SIZE__);assert(err==__MSG_SIZE__,"read\ unsuccessful");
+*/
+
 int main()
 {
+    // initialise
     fprintf(stderr, "MiniBug service started\n");
     init_log();
     int fd = init_net();
     int err;
+    char buf[__MSG_SIZE__];
 
-    char buf[__MSG_SIZE__];    
-    memset(buf, 0, __MSG_SIZE__);
-    err = read(fd, buf, __MSG_SIZE__);
+    // awaiting target from client
+    err = (int) read(fd, buf, __MSG_SIZE__);
     assert(err == __MSG_SIZE__, "read unsuccessful");
     printf("%s\n", buf);
+
+    // creating and tracing tracee
     pid_t pid = init_tracee(buf);
-    // tracee now created and traced
 
+    // notifying client
     strncpy(buf, "successful", __MSG_SIZE__);
     write(fd, buf, __MSG_SIZE__);
-    // client notified
 
+    // debug routine
+    debug_loop(pid, fd);
+
+    // destroy
     fprintf(stderr, "MiniBug shutting down (EXIT_SUCCESS)\n");
     unlink(__SOCKET_PATH__);    // free up file for further use on next startup
     return EXIT_SUCCESS;
 }
 
+void debug_loop(pid_t pid, int fd)
+{
+    int err;
+    REQUEST req;    
+
+    loop: printf("> debug loop .... \n");
+    err = (int) read(fd, &req, __REQ_SIZE__);
+    assert(err == __REQ_SIZE__, "read unsuccessful");
+    assert(req.control == __CMD__, "did not receive a command");
+
+    switch(req.value) 
+    {
+        case __EXIT__:                                  goto exit;
+        case __PEEK_REG__:      peek_reg(pid, fd);      break;
+
+        default:                printf("> unrecognised command .. awaiting another\n");
+                                req.control = __UNRECOGN__;
+                                req.value = __ANY__;
+                                write(fd, &req, __REQ_SIZE__);
+                                break;                  
+    }
+    goto loop;
+
+    exit: err = kill(pid, SIGKILL);
+    assert(err != -1, "killing tracee failed");
+    printf("> EXIT\n");
+}
+
 int init_net()
 {
     int fd, socket_fd;
@@ -35,7 +78,7 @@ int init_net()
     assert(socket_fd != -1, "Socket Creation Failed");
     server_addr.sun_family = AF_UNIX;
     strncpy(server_addr.sun_path, __SOCKET_PATH__, strlen(__SOCKET_PATH__) + 1);
-    sockaddr_un_len = strlen(server_addr.sun_path) + sizeof(server_addr.sun_family);
+    sockaddr_un_len = (socklen_t) strlen(server_addr.sun_path) + sizeof(server_addr.sun_family);
 
     // check if file already exists
     int err = access(__SOCKET_PATH__, F_OK);    // file exists -> err := zero
@@ -45,41 +88,39 @@ int init_net()
     err = bind(socket_fd, (struct sockaddr *) &server_addr, sockaddr_un_len);
     assert(err != -1, "Bind failed");
 
-    printf("listening: ..");
+    printf("> listening ..");
 
     err = listen(socket_fd, 5);
     assert(err != -1, "Listen failed");
 
-    fd = accept(socket_fd, (struct sockaddr *) &client_addr, &sockaddr_un_len);  
+    fd = accept(socket_fd, (struct sockaddr *) &client_addr, &sockaddr_un_len);
     assert(fd != -1, "Accept failed");
 
     printf(".. Connection established\n");
 
     return fd;
 }
 
-pid_t init_tracee(char* str)
+pid_t init_tracee(char *str)
 {
     //convert string to tokens
     int counter = 1;
     for(int i = 0; str[i] != 0x0; i++)
     {
         if(str[i] == 32) counter++;
     }
-    char** tokens = malloc(sizeof(void*) * counter);
+    char **tokens = malloc(sizeof(void *) * counter);
     counter = 0;
-    tokens[0] = str+counter;
+    tokens[0] = str + counter;
     for(int i = 0; str[i] != 0x0; i++)
     {
-        if(str[i] == 32) 
+        if(str[i] == 32)
         {
-            tokens[++counter] = str+i+1;
+            tokens[++counter] = str + i + 1;
             str[i] = 0x0;
         }
     }
 
-    fprintf(stderr, "%s", tokens[0]);
-
     // create tracee
     pid_t pid;
     int status, err;
@@ -89,26 +130,27 @@ pid_t init_tracee(char* str)
     if(!(pid)) // child
     {
         ptrace(PTRACE_TRACEME, 0, NULL, NULL);
-        // close(STDOUT_FILENO);
+        // close(STDOUT_FILENO); // currently we are writing stdout to log.txt anyway
+        raise(SIGSTOP);
         err = execvp(tokens[0], tokens);
         exit(EXIT_FAILURE);
-    } 
+    }
 
     // wait for tracee
     waitpid(pid, &status, 0);
     assert(!WIFEXITED(status), "execvp() failed");
-    printf("Tracee created, traced, and interrupted\n");
+    printf("> Tracee created, traced, and interrupted\n");
     return pid;
 }
 
 void init_log()
 {
-    FILE* log_out = fopen("log.txt", "w");
-    int log_fd = fileno(log_out); 
+    FILE *log_out = fopen("log.txt", "w");
+    int log_fd = fileno(log_out);
     close(1);           //closing stdout
     dup(log_fd);        //stdout is now written to "log.txt"      
     fclose(log_out);    // closing stream
     close(log_fd);      // closing File Descriptor
-                        // only stdout is open, and leads towards log.txt
-    printf("Log output redirected\n");
+    // only stdout is open, and leads towards log.txt
+    printf("> Log output redirected\n");
 }

MiniBug/mdb.h

@@ -1,7 +1,9 @@
-#include "khh.h"
+#include "functions.h"
 
 int init_net(); // initialises berkeley socket server
 
 void init_log(); // closes `stdout` and redirects every output to `stdout` to `log.txt`
 
-pid_t init_tracee(char* str); // starts and traces tracee
+pid_t init_tracee(char *str); // starts and traces tracee
+
+void debug_loop(pid_t pid, int fd);