new dbug.c (security fix)
Fred Fish
fnf at unisoft.UUCP
Sat Jan 19 13:21:24 AEST 1985
# The previously distributed version of dbug.c had a serious
# security hole. When linked with a setuid program, it allowed
# any user to redirect the debugger output stream to any file
# that the setuid program was capable of writing to.
# Since there are quite a few changes and additions I decided to
# simply repost dbug.c rather than the diffs.
#--------CUT---------CUT---------CUT---------CUT--------#
#########################################################
# #
# This is a shell archive file. To extract files: #
# #
# 1) Make a directory for the files. #
# 2) Write a file, such as "file.shar", containing #
# this archive file into the directory. #
# 3) Type "sh file.shar". Do not use csh. #
# #
#########################################################
#
#
echo Extracting dbug.c:
sed 's/^Z//' >dbug.c <<\STUNKYFLUFF
Z/************************************************************************
Z * *
Z * Copyright (c) 1984, Fred Fish *
Z * All Rights Reserved *
Z * *
Z * This software and/or documentation is released into the *
Z * public domain for personal, non-commercial use only. *
Z * Limited rights to use, modify, and redistribute are hereby *
Z * granted for non-commercial purposes, provided that all *
Z * copyright notices remain intact and all changes are clearly *
Z * documented. The author makes no warranty of any kind with *
Z * respect to this product and explicitly disclaims any implied *
Z * warranties of merchantability or fitness for any particular *
Z * purpose. *
Z * *
Z ************************************************************************
Z */
Z
Z
Z/*
Z * FILE
Z *
Z * dbug.c runtime support routines for dbug package
Z *
Z * SCCS
Z *
Z * @(#)dbug.c 1.5 1/18/85
Z *
Z * DESCRIPTION
Z *
Z * These are the runtime support routines for the dbug package.
Z * The dbug package has two main components; the user include
Z * file containing various macro definitions, and the runtime
Z * support routines which are called from the macro expansions.
Z *
Z * Externally visible functions in the runtime support module
Z * use the naming convention pattern "_db_xx...xx_", thus
Z * they are unlikely to collide with user defined function names.
Z *
Z * AUTHOR
Z *
Z * Fred Fish
Z * (Currently at UniSoft Systems, Berkeley Ca.)
Z *
Z */
Z
Z
Z#include <stdio.h>
Z
Z/*
Z * Manifest constants that should not require any changes.
Z */
Z
Z#define FALSE 0 /* Boolean FALSE */
Z#define TRUE 1 /* Boolean TRUE */
Z#define EOS '\000' /* End Of String marker */
Z
Z/*
Z * Manifest constants which may be "tuned" if desired.
Z */
Z
Z#define PRINTBUF 1024 /* Print buffer size */
Z#define INDENT 4 /* Indentation per trace level */
Z#define MAXDEPTH 200 /* Maximum trace depth default */
Z
Z/*
Z * The following flags are used to determine which
Z * capabilities the user has enabled with the state
Z * push macro.
Z */
Z
Z#define TRACE_ON 000001 /* Trace enabled */
Z#define DEBUG_ON 000002 /* Debug enabled */
Z#define FILE_ON 000004 /* File name print enabled */
Z#define LINE_ON 000010 /* Line number print enabled */
Z#define DEPTH_ON 000020 /* Function nest level print enabled */
Z#define PROCESS_ON 000040 /* Process name print enabled */
Z
Z#define TRACING (stack -> flags & TRACE_ON)
Z#define DEBUGGING (stack -> flags & DEBUG_ON)
Z#define STREQ(a,b) (strcmp(a,b) == 0)
Z
Z/*
Z * Typedefs to make things more obvious.
Z */
Z
Z#define VOID void /* Can't use typedef for most compilers */
Ztypedef int BOOLEAN;
Z
Z/*
Z * Make it easy to change storage classes if necessary.
Z */
Z
Z#define LOCAL static /* Names not needed by outside world */
Z#define IMPORT extern /* Names defined externally */
Z#define EXPORT /* Allocated here, available globally */
Z#define AUTO auto /* Names to be allocated on stack */
Z#define REGISTER register /* Names to be placed in registers */
Z
Z/*
Z * Variables which are available externally but should only
Z * be accessed via the macro package facilities.
Z */
Z
ZEXPORT FILE *_db_fp_ = stderr; /* Output stream, default stderr */
ZEXPORT char *_db_process_ = "dbug"; /* Pointer to process name; argv[0] */
ZEXPORT BOOLEAN _db_on_ = FALSE; /* TRUE if debugging currently on */
Z
Z/*
Z * Externally supplied functions.
Z */
Z
Z#ifdef unix /* Only needed for unix */
ZIMPORT int chown (); /* Change owner of a file */
ZIMPORT int getgid (); /* Get real group id */
ZIMPORT int getuid (); /* Get real user id */
ZIMPORT int access (); /* Test file for access */
Z#endif
Z
ZIMPORT int fprintf (); /* Formatted print on file */
ZIMPORT int fflush (); /* Flush output for stream */
ZIMPORT char *strcpy (); /* Copy strings around */
ZIMPORT int strlen (); /* Find length of string */
ZIMPORT char *malloc (); /* Allocate memory */
ZIMPORT int atoi (); /* Convert ascii to integer */
Z
Z
Z/*
Z * The user may specify a list of functions to trace or
Z * debug. These lists are kept in a linear linked list,
Z * a very simple implementation.
Z */
Z
Zstruct link {
Z char *string; /* Pointer to link's contents */
Z struct link *next_link; /* Pointer to the next link */
Z};
Z
Z
Z/*
Z * Debugging states can be pushed or popped off of a
Z * stack which is implemented as a linked list. Note
Z * that the head of the list is the current state and the
Z * stack is pushed by adding a new state to the head of the
Z * list or popped by removing the first link.
Z */
Z
Zstruct state {
Z int flags; /* Current state flags */
Z int maxdepth; /* Current maximum trace depth */
Z int level; /* Current function nesting level */
Z FILE *out_file; /* Current output stream */
Z struct link *functions; /* List of functions */
Z struct link *keywords; /* List of debug keywords */
Z struct link *processes; /* List of process names */
Z struct state *next_state; /* Next state in the list */
Z};
Z
ZLOCAL struct state *stack = NULL; /* Linked list of stacked states */
Z
Z/*
Z * Local variables not seen by user.
Z */
Z
ZLOCAL char *func = "?func"; /* Name of current user function */
ZLOCAL char *file = "?file"; /* Name of current user file */
ZLOCAL BOOLEAN init_done = FALSE;/* Set to TRUE when initialization done */
Z
ZLOCAL struct link *ListParse ();/* Parse a debug command string */
ZLOCAL char *StrDup (); /* Make a fresh copy of a string */
ZLOCAL VOID OpenFile (); /* Open debug output stream */
ZLOCAL VOID CloseFile (); /* Close debug output stream */
ZLOCAL VOID PushState (); /* Push current debug state */
ZLOCAL VOID ChangeOwner (); /* Change file owner and group */
ZLOCAL BOOLEAN DoTrace (); /* Test for tracing enabled */
ZLOCAL BOOLEAN Writable (); /* Test to see if file is writable */
ZLOCAL char *DbugMalloc (); /* Allocate memory for runtime support */
ZLOCAL char *BaseName (); /* Remove leading pathname components */
Z
Z /* Supplied in Sys V runtime environ */
ZLOCAL char *strtok (); /* Break string into tokens */
ZLOCAL char *strrchr (); /* Find last occurance of char */
Z
Z/*
Z * Miscellaneous printf format strings.
Z */
Z
Z#define MSG1 "%s: missing DBUG_RETURN or DBUG_VOID_RETURN macro in function \"%s\"\n"
Z#define MSG2 "%s: can't open debug output stream \"%s\": "
Z#define MSG3 "%s: can't close debug file: "
Z#define MSG4 "%s: debugger aborting because %s\n"
Z#define MSG5 "%s: can't change owner/group of \"%s\": "
Z
Z/*
Z * Macros and defines for testing file accessibility under UNIX.
Z */
Z
Z#ifdef unix
Z# define A_EXISTS 00 /* Test for file existance */
Z# define A_EXECUTE 01 /* Test for execute permission */
Z# define A_WRITE 02 /* Test for write access */
Z# define A_READ 03 /* Test for read access */
Z# define EXISTS(pathname) (access (pathname, A_EXISTS) == 0)
Z# define WRITABLE(pathname) (access (pathname, A_WRITE) == 0)
Z#else
Z# define EXISTS(pathname) (FALSE) /* Assume no existance */
Z#endif
Z
Z
Z
Z/*
Z * FUNCTION
Z *
Z * _db_push_ push current debugger state and set up new one
Z *
Z * SYNOPSIS
Z *
Z * VOID _db_push_ (control)
Z * char *control;
Z *
Z * DESCRIPTION
Z *
Z * Given pointer to a debug control string in "control", pushes
Z * the current debug state, parses the control string, and sets
Z * up a new debug state.
Z *
Z * The only attribute of the new state inherited from the previous
Z * state is the current function nesting level. This can be
Z * overridden by using the "r" flag in the control string.
Z *
Z * The debug control string is a sequence of colon separated fields
Z * as follows:
Z *
Z * <field_1>:<field_2>:...:<field_N>
Z *
Z * Each field consists of a mandatory flag character followed by
Z * an optional "," and comma separated list of modifiers:
Z *
Z * flag[,modifier,modifier,...,modifier]
Z *
Z * The currently recognized flag characters are:
Z *
Z * d Enable output from DBUG_<N> macros for
Z * for the current state. May be followed
Z * by a list of keywords which selects output
Z * only for the DBUG macros with that keyword.
Z * A null list of keywords implies output for
Z * all macros.
Z *
Z * f Limit debugging and/or tracing to the
Z * list of named functions. Note that a null
Z * list will disable all functions. The
Z * appropriate "d" or "t" flags must still
Z * be given, this flag only limits their
Z * actions if they are enabled.
Z *
Z * F Identify the source file name for each
Z * line of debug or trace output.
Z *
Z * L Identify the source file line number for
Z * each line of debug or trace output.
Z *
Z * n Print the current function nesting depth for
Z * each line of debug or trace output.
Z *
Z * p Limit debugger actions to specified processes.
Z * A process must be identified with the
Z * DBUG_PROCESS macro and match one in the list
Z * for debugger actions to occur.
Z *
Z * P Print the current process name for each
Z * line of debug or trace output.
Z *
Z * r When pushing a new state, do not inherit
Z * the previous state's function nesting level.
Z * Useful when the output is to start at the
Z * left margin.
Z *
Z * t Enable function call/exit trace lines.
Z * May be followed by a list (containing only
Z * one modifier) giving a numeric maximum
Z * trace level, beyond which no output will
Z * occur for either debugging or tracing
Z * macros. The default is a compile time
Z * option.
Z *
Z * Some examples of debug control strings which might appear
Z * on a shell command line (the "-#" is typically used to
Z * introduce a control string to an application program) are:
Z *
Z * -#d:t
Z * -#d:f,main,subr1:F:L:t,20
Z * -#d,input,output,files:n
Z *
Z */
Z
Z
ZVOID _db_push_ (control)
Zchar *control;
Z{
Z REGISTER char *scan;
Z REGISTER struct link *temp;
Z
Z control = StrDup (control);
Z PushState ();
Z scan = strtok (control, ":");
Z for (; scan != NULL; scan = strtok ((char *)NULL, ":")) {
Z switch (*scan++) {
Z case 'd':
Z _db_on_ = TRUE;
Z stack -> flags |= DEBUG_ON;
Z if (*scan++ == ',') {
Z stack -> keywords = ListParse (scan);
Z }
Z break;
Z case 'f':
Z if (*scan++ == ',') {
Z stack -> functions = ListParse (scan);
Z }
Z break;
Z case 'F':
Z stack -> flags |= FILE_ON;
Z break;
Z case 'L':
Z stack -> flags |= LINE_ON;
Z break;
Z case 'n':
Z stack -> flags |= DEPTH_ON;
Z break;
Z case 'o':
Z if (*scan++ == ',') {
Z temp = ListParse (scan);
Z OpenFile (temp -> string);
Z FreeList (temp);
Z } else {
Z OpenFile ("-");
Z }
Z break;
Z case 'p':
Z if (*scan++ == ',') {
Z stack -> processes = ListParse (scan);
Z }
Z break;
Z case 'P':
Z stack -> flags |= PROCESS_ON;
Z break;
Z case 'r':
Z stack -> level = 0;
Z break;
Z case 't':
Z stack -> flags |= TRACE_ON;
Z if (*scan++ == ',') {
Z temp = ListParse (scan);
Z stack -> maxdepth = atoi (temp -> string);
Z FreeList (temp);
Z }
Z break;
Z }
Z }
Z free (control);
Z}
Z
Z
Z
Z/*
Z * FUNCTION
Z *
Z * _db_pop_ pop the debug stack
Z *
Z * DESCRIPTION
Z *
Z * Pops the debug stack, returning the debug state to its
Z * condition prior to the most recent _db_push_ invocation.
Z * Note that the pop will fail if it would remove the last
Z * valid state from the stack. This prevents user errors
Z * in the push/pop sequence from screwing up the debugger.
Z * Maybe there should be some kind of warning printed if the
Z * user tries to pop too many states.
Z *
Z */
Z
ZVOID _db_pop_ ()
Z{
Z REGISTER struct state *discard;
Z
Z discard = stack;
Z if (discard != NULL && discard -> next_state != NULL) {
Z stack = discard -> next_state;
Z _db_fp_ = stack -> out_file;
Z if (discard -> keywords != NULL) {
Z FreeList (discard -> keywords);
Z }
Z if (discard -> functions != NULL) {
Z FreeList (discard -> functions);
Z }
Z if (discard -> processes != NULL) {
Z FreeList (discard -> processes);
Z }
Z CloseFile (discard -> out_file);
Z free ((char *) discard);
Z }
Z}
Z
Z
Z/*
Z * FUNCTION
Z *
Z * _db_enter_ process entry point to user function
Z *
Z * SYNOPSIS
Z *
Z * VOID _db_enter_ (_func_, _file_, _line_, _sfunc_, _sfile_, _slevel_)
Z * char *_func_; points to current function name
Z * char *_file_; points to current file name
Z * int _line_; called from source line number
Z * char **_sfunc_; save previous _func_
Z * char **_sfile_; save previous _file_
Z * int *_slevel_; save previous nesting level
Z *
Z * DESCRIPTION
Z *
Z * Called at the beginning of each user function to tell
Z * the debugger that a new function has been entered.
Z * Note that the pointers to the previous user function
Z * name and previous user file name are stored on the
Z * caller's stack (this is why the ENTER macro must be
Z * the first "executable" code in a function, since it
Z * allocates these storage locations). The previous nesting
Z * level is also stored on the callers stack for internal
Z * self consistency checks.
Z *
Z * Also prints a trace line if tracing is enabled and
Z * increments the current function nesting depth.
Z *
Z * Note that this mechanism allows the debugger to know
Z * what the current user function is at all times, without
Z * maintaining an internal stack for the function names.
Z *
Z */
Z
ZVOID _db_enter_ (_func_, _file_, _line_, _sfunc_, _sfile_, _slevel_)
Zchar *_func_;
Zchar *_file_;
Zint _line_;
Zchar **_sfunc_;
Zchar **_sfile_;
Zint *_slevel_;
Z{
Z if (!init_done) {
Z _db_push_ ("");
Z }
Z *_sfunc_ = func;
Z *_sfile_ = file;
Z func = _func_;
Z file = BaseName (_file_);
Z stack -> level += INDENT;
Z *_slevel_ = stack -> level;
Z if (DoTrace ()) {
Z DoPrefix (_line_);
Z Indent (stack -> level);
Z (VOID) fprintf (_db_fp_, ">%s\n", func);
Z (VOID) fflush (_db_fp_);
Z }
Z}
Z
Z
Z/*
Z * FUNCTION
Z *
Z * _db_return_ process exit from user function
Z *
Z * SYNOPSIS
Z *
Z * VOID _db_return_ (_line_, _sfunc_, _sfile_, _slevel_)
Z * int _line_; current source line number
Z * char **_sfunc_; where previous _func_ is to be retrieved
Z * char **_sfile_; where previous _file_ is to be retrieved
Z * int *_slevel_; where previous level was stashed
Z *
Z * DESCRIPTION
Z *
Z * Called just before user function executes an explicit or implicit
Z * return. Prints a trace line if trace is enabled, decrements
Z * the current nesting level, and restores the current function and
Z * file names from the defunct function's stack.
Z *
Z */
Z
ZVOID _db_return_ (_line_, _sfunc_, _sfile_, _slevel_)
Zint _line_;
Zchar **_sfunc_;
Zchar **_sfile_;
Zint *_slevel_;
Z{
Z if (!init_done) {
Z _db_push_ ("");
Z }
Z if (stack -> level != *_slevel_ && (TRACING || DEBUGGING)) {
Z (VOID) fprintf (_db_fp_, MSG1, _db_process_, func);
Z (VOID) fflush (_db_fp_);
Z } else if (DoTrace ()) {
Z DoPrefix (_line_);
Z Indent (stack -> level);
Z (VOID) fprintf (_db_fp_, "<%s\n", func);
Z (VOID) fflush (_db_fp_);
Z }
Z stack -> level = *_slevel_ - INDENT;
Z func = *_sfunc_;
Z file = *_sfile_;
Z}
Z
Z
Z/*
Z * FUNCTION
Z *
Z * _db_printf_ handle print of debug lines
Z *
Z * SYNOPSIS
Z *
Z * VOID _db_printf_ (_line_, keyword, format,
Z * a0, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11)
Z * int _line_;
Z * char *keyword, *format;
Z * int a0, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11;
Z *
Z * DESCRIPTION
Z *
Z * When invoked via one of the DBUG macros, tests the keyword
Z * to see if that macro has been selected for processing via
Z * the debugger control string, and if so, handles printing
Z * of the arguments via the format string. The line number
Z * of the DBUG macro in the source is found in _line_.
Z *
Z * Note that the format string SHOULD NOT include a terminating
Z * newline, this is supplied automatically.
Z *
Z * NOTE
Z *
Z * The rather ugly argument declaration is to handle some
Z * magic with respect to the number of arguments passed
Z * via the DBUG macros. The current maximum is 3 arguments
Z * (not including the keyword and format strings).
Z *
Z * If the args being passed by the DBUG macro are actually
Z * doubles (worst case) then there will be a total of 12
Z * ints on the stack for a PDP-11 or 6 ints on a 68000.
Z *
Z */
Z
Z/*VARARGS3*/
ZVOID _db_printf_ (_line_, keyword, format,
Z a0, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11)
Zint _line_;
Zchar *keyword, *format;
Zint a0, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11;
Z{
Z if (_db_keyword_ (keyword)) {
Z DoPrefix (_line_);
Z if (TRACING) {
Z Indent (stack -> level + INDENT);
Z } else {
Z (VOID) fprintf (_db_fp_, "%s: ", func);
Z }
Z (VOID) fprintf (_db_fp_, "%s: ", keyword);
Z (VOID) fprintf (_db_fp_, format, a0, a1, a2, a3, a4, a5, a6,a7, a8,
Z a9, a10, a11);
Z (VOID) fprintf (_db_fp_, "\n");
Z (VOID) fflush (_db_fp_);
Z }
Z}
Z
Z
Z/*
Z * FUNCTION
Z *
Z * ListParse parse list of modifiers in debug control string
Z *
Z * SYNOPSIS
Z *
Z * LOCAL struct link *ListParse (ctlp)
Z * char *ctlp;
Z *
Z * DESCRIPTION
Z *
Z * Given pointer to a comma separated list of strings in "cltp",
Z * parses the list, building a list and returning a pointer to it.
Z * The original comma separated list is destroyed in the process of
Z * building the linked list, thus it had better be a duplicate
Z * if it is important.
Z *
Z * Note that since each link is added at the head of the list,
Z * the final list will be in "reverse order", which is not
Z * significant for our usage here.
Z *
Z */
Z
ZLOCAL struct link *ListParse (ctlp)
Zchar *ctlp;
Z{
Z REGISTER char *start;
Z REGISTER struct link *new;
Z REGISTER struct link *head;
Z
Z head = NULL;
Z while (*ctlp != EOS) {
Z start = ctlp;
Z while (*ctlp != EOS && *ctlp != ',') {
Z ctlp++;
Z }
Z if (*ctlp == ',') {
Z *ctlp++ = EOS;
Z }
Z new = (struct link *) DbugMalloc (sizeof (struct link));
Z new -> string = StrDup (start);
Z new -> next_link = head;
Z head = new;
Z }
Z return (head);
Z}
Z
Z
Z/*
Z * FUNCTION
Z *
Z * InList test a given string for member of a given list
Z *
Z * SYNOPSIS
Z *
Z * LOCAL BOOLEAN InList (linkp, cp)
Z * struct link *linkp;
Z * char *cp;
Z *
Z * DESCRIPTION
Z *
Z * Tests the string pointed to by "cp" to determine if it is in
Z * the list pointed to by "linkp". Linkp points to the first
Z * link in the list. If linkp is NULL then the string is treated
Z * as if it is in the list (I.E all strings are in the null list).
Z * This may seem rather strange at first but leads to the desired
Z * operation if no list is given. The net effect is that all
Z * strings will be accepted when there is no list, and when there
Z * is a list, only those strings in the list will be accepted.
Z *
Z */
Z
ZLOCAL BOOLEAN InList (linkp, cp)
Zstruct link *linkp;
Zchar *cp;
Z{
Z REGISTER struct link *scan;
Z REGISTER BOOLEAN accept;
Z
Z if (linkp == NULL) {
Z accept = TRUE;
Z } else {
Z accept = FALSE;
Z for (scan = linkp; scan != NULL; scan = scan -> next_link) {
Z if (STREQ (scan -> string, cp)) {
Z accept = TRUE;
Z break;
Z }
Z }
Z }
Z return (accept);
Z}
Z
Z
Z/*
Z * FUNCTION
Z *
Z * PushState push current state onto stack and set up new one
Z *
Z * SYNOPSIS
Z *
Z * LOCAL VOID PushState ()
Z *
Z * DESCRIPTION
Z *
Z * Pushes the current state on the state stack, and initializes
Z * a new state. The only parameter inherited from the previous
Z * state is the function nesting level. This action can be
Z * inhibited if desired, via the "r" flag.
Z *
Z * The state stack is a linked list of states, with the new
Z * state added at the head. This allows the stack to grow
Z * to the limits of memory if necessary.
Z *
Z */
Z
ZLOCAL VOID PushState ()
Z{
Z REGISTER struct state *new;
Z
Z new = (struct state *) DbugMalloc (sizeof (struct state));
Z new -> flags = 0;
Z new -> maxdepth = MAXDEPTH;
Z if (stack != NULL) {
Z new -> level = stack -> level;
Z } else {
Z new -> level = 0;
Z }
Z new -> out_file = stderr;
Z new -> functions = NULL;
Z new -> keywords = NULL;
Z new -> processes = NULL;
Z new -> next_state = stack;
Z stack = new;
Z init_done = TRUE;
Z}
Z
Z
Z/*
Z * FUNCTION
Z *
Z * DoTrace check to see if tracing is current enabled
Z *
Z * SYNOPSIS
Z *
Z * LOCAL BOOLEAN DoTrace ()
Z *
Z * DESCRIPTION
Z *
Z * Checks to see if tracing is enabled based on whether the
Z * user has specified tracing, the maximum trace depth has
Z * not yet been reached, the current function is selected,
Z * and the current process is selected. Returns TRUE if
Z * tracing is enabled, FALSE otherwise.
Z *
Z */
Z
ZLOCAL BOOLEAN DoTrace ()
Z{
Z REGISTER BOOLEAN trace;
Z
Z trace = FALSE;
Z if (TRACING) {
Z if (stack -> level / INDENT <= stack -> maxdepth) {
Z if (InList (stack -> functions, func)) {
Z if (InList (stack -> processes, _db_process_)) {
Z trace = TRUE;
Z }
Z }
Z }
Z }
Z return (trace);
Z}
Z
Z
Z/*
Z * FUNCTION
Z *
Z * _db_keyword_ test keyword for member of keyword list
Z *
Z * SYNOPSIS
Z *
Z * BOOLEAN _db_keyword_ (keyword)
Z * char *keyword;
Z *
Z * DESCRIPTION
Z *
Z * Test a keyword to determine if it is in the currently active
Z * keyword list. As with the function list, a keyword is accepted
Z * if the list is null, otherwise it must match one of the list
Z * members. When debugging is not on, no keywords are accepted.
Z * After the maximum trace level is exceeded, no keywords are
Z * accepted (this behavior subject to change). Additionally,
Z * the current function and process must be accepted based on
Z * their respective lists.
Z *
Z * Returns TRUE if keyword accepted, FALSE otherwise.
Z *
Z */
Z
ZBOOLEAN _db_keyword_ (keyword)
Zchar *keyword;
Z{
Z REGISTER BOOLEAN accept;
Z
Z if (!init_done) {
Z _db_push_ ("");
Z }
Z accept = FALSE;
Z if (DEBUGGING) {
Z if (stack -> level / INDENT <= stack -> maxdepth) {
Z if (InList (stack -> functions, func)) {
Z if (InList (stack -> keywords, keyword)) {
Z if (InList (stack -> processes, _db_process_)) {
Z accept = TRUE;
Z }
Z }
Z }
Z }
Z }
Z return (accept);
Z}
Z
Z
Z/*
Z * FUNCTION
Z *
Z * Indent indent a line to the given indentation level
Z *
Z * SYNOPSIS
Z *
Z * LOCAL Indent (indent)
Z * int indent;
Z *
Z * DESCRIPTION
Z *
Z * Indent a line to the given level. Note that this is
Z * a simple minded but portable implementation.
Z * There are better ways.
Z *
Z */
Z
ZLOCAL Indent (indent)
Zint indent;
Z{
Z REGISTER int count;
Z AUTO char buffer[PRINTBUF];
Z
Z for (count = 0; (count < (indent - INDENT)) && (count < (PRINTBUF - 1)); count++) {
Z if ((count % INDENT) == 0) {
Z buffer[count] = '|';
Z } else {
Z buffer[count] = ' ';
Z }
Z }
Z buffer[count] = EOS;
Z (VOID) fprintf (_db_fp_, buffer);
Z (VOID) fflush (_db_fp_);
Z}
Z
Z
Z/*
Z * FUNCTION
Z *
Z * FreeList free all memory associated with a linked list
Z *
Z * SYNOPSIS
Z *
Z * LOCAL FreeList (linkp)
Z * struct link *linkp;
Z *
Z * DESCRIPTION
Z *
Z * Given pointer to the head of a linked list, frees all
Z * memory held by the list and the members of the list.
Z *
Z */
Z
ZLOCAL FreeList (linkp)
Zstruct link *linkp;
Z{
Z REGISTER struct link *old;
Z
Z while (linkp != NULL) {
Z old = linkp;
Z linkp = linkp -> next_link;
Z if (old -> string != NULL) {
Z free (old -> string);
Z }
Z free ((char *) old);
Z }
Z}
Z
Z
Z/*
Z * FUNCTION
Z *
Z * StrDup make a duplicate of a string in new memory
Z *
Z * SYNOPSIS
Z *
Z * LOCAL char *StrDup (string)
Z * char *string;
Z *
Z * DESCRIPTION
Z *
Z * Given pointer to a string, allocates sufficient memory to make
Z * a duplicate copy, and copies the string to the newly allocated
Z * memory. Failure to allocated sufficient memory is immediately
Z * fatal.
Z *
Z */
Z
Z
ZLOCAL char *StrDup (string)
Zchar *string;
Z{
Z REGISTER char *new;
Z
Z new = DbugMalloc (strlen (string) + 1);
Z (VOID) strcpy (new, string);
Z return (new);
Z}
Z
Z
Z/*
Z * FUNCTION
Z *
Z * DoPrefix print debugger line prefix prior to indentation
Z *
Z * SYNOPSIS
Z *
Z * LOCAL DoPrefix (_line_)
Z * int _line_;
Z *
Z * DESCRIPTION
Z *
Z * Print prefix common to all debugger output lines, prior to
Z * doing indentation if necessary. Print such information as
Z * current process name, current source file name and line number,
Z * and current function nesting depth.
Z *
Z */
Z
Z
ZLOCAL DoPrefix (_line_)
Zint _line_;
Z{
Z if (stack -> flags & PROCESS_ON) {
Z (VOID) fprintf (_db_fp_, "%s: ", _db_process_);
Z }
Z if (stack -> flags & FILE_ON) {
Z (VOID) fprintf (_db_fp_, "%14s: ", file);
Z }
Z if (stack -> flags & LINE_ON) {
Z (VOID) fprintf (_db_fp_, "%5d: ", _line_);
Z }
Z if (stack -> flags & DEPTH_ON) {
Z (VOID) fprintf (_db_fp_, "%4d: ", stack -> level / INDENT);
Z }
Z (VOID) fflush (_db_fp_);
Z}
Z
Z
Z/*
Z * FUNCTION
Z *
Z * OpenFile open new output stream for debugger output
Z *
Z * SYNOPSIS
Z *
Z * LOCAL VOID OpenFile (name)
Z * char *name;
Z *
Z * DESCRIPTION
Z *
Z * Given name of a new file (or "-" for stdout) opens the file
Z * and sets the output stream to the new file.
Z *
Z */
Z
ZLOCAL VOID OpenFile (name)
Zchar *name;
Z{
Z REGISTER FILE *fp;
Z REGISTER BOOLEAN newfile;
Z
Z if (name != NULL) {
Z if (strcmp (name, "-") == 0) {
Z _db_fp_ = stdout;
Z stack -> out_file = _db_fp_;
Z } else {
Z if (!Writable (name)) {
Z (VOID) fprintf (_db_fp_, MSG2, _db_process_, name);
Z perror ("");
Z (VOID) fflush (_db_fp_);
Z } else {
Z if (EXISTS (name)) {
Z newfile = FALSE;
Z } else {
Z newfile = TRUE;
Z }
Z fp = fopen (name, "a");
Z if (fp == NULL) {
Z (VOID) fprintf (_db_fp_, MSG2, _db_process_, name);
Z perror ("");
Z (VOID) fflush (_db_fp_);
Z } else {
Z _db_fp_ = fp;
Z stack -> out_file = fp;
Z if (newfile) {
Z ChangeOwner (name);
Z }
Z }
Z }
Z }
Z }
Z}
Z
Z
Z/*
Z * FUNCTION
Z *
Z * CloseFile close the debug output stream
Z *
Z * SYNOPSIS
Z *
Z * LOCAL VOID CloseFile (fp)
Z * FILE *fp;
Z *
Z * DESCRIPTION
Z *
Z * Closes the debug output stream unless it is standard output
Z * or standard error.
Z *
Z */
Z
ZLOCAL VOID CloseFile (fp)
ZFILE *fp;
Z{
Z if (fp != stderr && fp != stdout) {
Z if (fclose (fp) == 0) {
Z (VOID) fprintf (stderr, MSG3, _db_process_);
Z perror ("");
Z (VOID) fflush (_db_fp_);
Z }
Z }
Z}
Z
Z
Z/*
Z * FUNCTION
Z *
Z * DbugExit print error message and exit
Z *
Z * SYNOPSIS
Z *
Z * LOCAL VOID DbugExit (why)
Z * char *why;
Z *
Z * DESCRIPTION
Z *
Z * Prints error message using current process name, the reason for
Z * aborting (typically out of memory), and exits with status 1.
Z * This should probably be changed to use a status code
Z * defined in the user's debugger include file.
Z *
Z */
Z
ZLOCAL VOID DbugExit (why)
Zchar *why;
Z{
Z (VOID) fprintf (stderr, MSG4, _db_process_, why);
Z (VOID) fflush (stderr);
Z exit (1);
Z}
Z
Z
Z/*
Z * FUNCTION
Z *
Z * DbugMalloc allocate memory for debugger runtime support
Z *
Z * SYNOPSIS
Z *
Z * LOCAL char *DbugMalloc (size)
Z * int size;
Z *
Z * DESCRIPTION
Z *
Z * Allocate more memory for debugger runtime support functions.
Z * Failure to to allocate the requested number of bytes is
Z * immediately fatal to the current process. This may be
Z * rather unfriendly behavior. It might be better to simply
Z * print a warning message, freeze the current debugger state,
Z * and continue execution.
Z *
Z */
Z
ZLOCAL char *DbugMalloc (size)
Zint size;
Z{
Z register char *new;
Z
Z new = malloc ((unsigned int) size);
Z if (new == NULL) {
Z DbugExit ("out of memory");
Z }
Z return (new);
Z}
Z
Z
Z/*
Z * This function may be eliminated when strtok is available
Z * in the runtime environment (missing from BSD4.1).
Z */
Z
ZLOCAL char *strtok (s1, s2)
Zchar *s1, *s2;
Z{
Z static char *end = NULL;
Z REGISTER char *rtnval;
Z
Z rtnval = NULL;
Z if (s2 != NULL) {
Z if (s1 != NULL) {
Z end = s1;
Z rtnval = strtok ((char *) NULL, s2);
Z } else if (end != NULL) {
Z if (*end != EOS) {
Z rtnval = end;
Z while (*end != *s2 && *end != EOS) {end++;}
Z if (*end != EOS) {
Z *end++ = EOS;
Z }
Z }
Z }
Z }
Z return (rtnval);
Z}
Z
Z
Z/*
Z * FUNCTION
Z *
Z * BaseName strip leading pathname components from name
Z *
Z * SYNOPSIS
Z *
Z * LOCAL char *BaseName (pathname)
Z * char *pathname;
Z *
Z * DESCRIPTION
Z *
Z * Given pointer to a complete pathname, locates the base file
Z * name at the end of the pathname and returns a pointer to
Z * it.
Z *
Z */
Z
ZLOCAL char *BaseName (pathname)
Zchar *pathname;
Z{
Z register char *base;
Z
Z base = strrchr (pathname, '/');
Z if (base++ == NULL) {
Z base = pathname;
Z }
Z return (base);
Z}
Z
Z
Z/*
Z * FUNCTION
Z *
Z * Writable test to see if a pathname is writable/creatable
Z *
Z * SYNOPSIS
Z *
Z * LOCAL BOOLEAN Writable (pathname)
Z * char *pathname;
Z *
Z * DESCRIPTION
Z *
Z * Because the debugger might be linked in with a program that
Z * runs with the set-uid-bit (suid) set, we have to be careful
Z * about opening a user named file for debug output. This consists
Z * of checking the file for write access with the real user id,
Z * or checking the directory where the file will be created.
Z *
Z * Returns TRUE if the user would normally be allowed write or
Z * create access to the named file. Returns FALSE otherwise.
Z *
Z */
Z
ZLOCAL BOOLEAN Writable (pathname)
Zchar *pathname;
Z{
Z REGISTER BOOLEAN granted;
Z REGISTER char *lastslash;
Z
Z#ifndef unix
Z return (TRUE);
Z#else
Z granted = FALSE;
Z if (EXISTS (pathname)) {
Z if (WRITABLE (pathname)) {
Z granted = TRUE;
Z }
Z } else {
Z lastslash = strrchr (pathname, '/');
Z if (lastslash != NULL) {
Z *lastslash = EOS;
Z } else {
Z pathname = ".";
Z }
Z if (WRITABLE (pathname)) {
Z granted = TRUE;
Z }
Z if (lastslash != NULL) {
Z *lastslash = '/';
Z }
Z }
Z return (granted);
Z#endif
Z}
Z
Z
Z/*
Z * This function may be eliminated when strrchr is available
Z * in the runtime environment (missing from BSD4.1).
Z * Alternately, you can use rindex() on BSD systems.
Z */
Z
ZLOCAL char *strrchr (s, c)
Zchar *s;
Zchar c;
Z{
Z REGISTER char *scan;
Z
Z for (scan = s; *scan != EOS; scan++) {;}
Z while (scan > s && *--scan != c) {;}
Z if (*scan != c) {
Z scan = NULL;
Z }
Z return (scan);
Z}
Z
Z
Z/*
Z * FUNCTION
Z *
Z * ChangeOwner change owner to real user for suid programs
Z *
Z * SYNOPSIS
Z *
Z * LOCAL VOID ChangeOwner (pathname)
Z *
Z * DESCRIPTION
Z *
Z * For unix systems, change the owner of the newly created debug
Z * file to the real owner. This is strictly for the benefit of
Z * programs that are running with the set-user-id bit set.
Z *
Z * Note that at this point, the fact that pathname represents
Z * a newly created file has already been established. If the
Z * program that the debugger is linked to is not running with
Z * the suid bit set, then this operation is redundant (but
Z * harmless).
Z *
Z */
Z
ZLOCAL VOID ChangeOwner (pathname)
Zchar *pathname;
Z{
Z#ifdef unix
Z if (chown (pathname, getuid (), getgid ()) == -1) {
Z (VOID) fprintf (stderr, MSG5, _db_process_, pathname);
Z perror ("");
Z (VOID) fflush (_db_fp_);
Z }
Z#endif
Z}
STUNKYFLUFF
set `sum dbug.c`
if test 14117 != $1
then
echo dbug.c: Checksum error. Is: $1, should be: 14117.
fi
echo ALL DONE BUNKY!
exit 0
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