Changeset 1995

Timestamp:

13/12/2007 00:21:38 (13 months ago)

Author:

chris

Message:

Restructure intercept_errornow() for clarity.

Move delay code out of macro and into intercept_errornow() to
simplify macro.

Clear hook functions in intercept_clear_setup().

Check that intercept_filename is not NULL before comparing it with
anything.

Change some TRACEx macros to BOX_TRACE.

Files:

• box/trunk/lib/intercept/intercept.cpp (modified) (14 diffs)

box/trunk/lib/intercept/intercept.cpp

@@ -75 +75 @@
 int intercept_delay_ms = 0;
 
+static opendir_t*  opendir_real  = NULL;
+static readdir_t*  readdir_real  = NULL;
+static readdir_t*  readdir_hook  = NULL;
+static closedir_t* closedir_real = NULL;
+static lstat_t*    lstat_real    = NULL;
+static lstat_t*    lstat_hook    = NULL;
+static const char* lstat_file    = NULL;
+
 #define SIZE_ALWAYS_ERROR       -773
 
@@ -86 +94 @@
         intercept_filepos = 0;
         intercept_delay_ms = 0;
+        readdir_hook = NULL;
+        lstat_hook = NULL;
 }
 
@@ -95 +105 @@
 void intercept_setup_error(const char *filename, unsigned int errorafter, int errortoreturn, int syscalltoerror)
 {
-        TRACE4("Setup for error: %s, after %d, err %d, syscall %d\n", filename, errorafter, errortoreturn, syscalltoerror);
+        BOX_TRACE("Setup for error: " << filename << 
+                ", after " << errorafter <<
+                ", err " << errortoreturn <<
+                ", syscall " << syscalltoerror);
+
         intercept_count = 1;
         intercept_filename = filename;
@@ -109 +123 @@
         int delay_ms, int syscall_to_delay, int num_delays)
 {
-        TRACE5("Setup for delay: %s, after %d, wait %d ms, times %d, "
-                "syscall %d\n", filename, delay_after, delay_ms, 
-                num_delays, syscall_to_delay);
+        BOX_TRACE("Setup for delay: " << filename <<
+                ", after " << delay_after <<
+                ", wait " << delay_ms << " ms" <<
+                ", times " << num_delays <<
+                ", syscall " << syscall_to_delay);
+
         intercept_count = num_delays;
         intercept_filename = filename;
@@ -121 +138 @@
         intercept_delay_ms = delay_ms;
 }
+
 bool intercept_errornow(int d, int size, int syscallnum)
 {
-        if(intercept_filedes != -1 && d == intercept_filedes && syscallnum == intercept_syscall)
-        {
-                //printf("Checking for err, %d, %d, %d\n", d, size, syscallnum);
-                if(size == SIZE_ALWAYS_ERROR)
-                {
-                        // Looks good for an error!
-                        TRACE2("Returning error %d for syscall %d\n", intercept_errno, syscallnum);
-                        return true;
-                }
-                // where are we in the file?
-                if(intercept_filepos >= intercept_errorafter || intercept_filepos >= ((off_t)intercept_errorafter - size))
-                {
-                        if (intercept_errno != 0)
-                        {
-                                TRACE3("Returning error %d for syscall %d, "
-                                        "file pos %d\n", intercept_errno, 
-                                        syscallnum, (int)intercept_filepos);
-                        }
-                        else if (intercept_delay_ms != 0)
-                        {
-                                TRACE3("Delaying %d ms for syscall %d, "
-                                        "file pos %d\n", intercept_delay_ms, 
-                                        syscallnum, (int)intercept_filepos);
-                        }
-
-                        return true;
-                }
-        }
-        return false;   // no error please!
+        ASSERT(intercept_count > 0)
+
+        if (intercept_filedes == -1)
+        {
+                return false; // no error please!
+        }
+
+        if (d != intercept_filedes)
+        {
+                return false; // no error please!
+        }
+
+        if (syscallnum != intercept_syscall)
+        {
+                return false; // no error please!
+        }
+
+        bool ret = false; // no error unless one of the conditions matches
+
+        //printf("Checking for err, %d, %d, %d\n", d, size, syscallnum);
+
+        if (intercept_delay_ms != 0)
+        {
+                BOX_TRACE("Delaying " << intercept_delay_ms << " ms " <<
+                        " for syscall " << syscallnum << 
+                        " at " << intercept_filepos);
+
+                struct timespec tm;
+                tm.tv_sec = intercept_delay_ms / 1000;
+                tm.tv_nsec = (intercept_delay_ms % 1000) * 1000000;
+                while (nanosleep(&tm, &tm) != 0 &&
+                        errno == EINTR) { }
+        }
+
+        if (size == SIZE_ALWAYS_ERROR)
+        {
+                // Looks good for an error!
+                BOX_TRACE("Returning error " << intercept_errno <<
+                        " for syscall " << syscallnum);
+                ret = true;
+        }
+        else if (intercept_filepos + size < intercept_errorafter)
+        {
+                return false; // no error please
+        }
+        else if (intercept_errno != 0)
+        {
+                BOX_TRACE("Returning error " << intercept_errno << 
+                        " for syscall " << syscallnum <<
+                        " at " << intercept_filepos);
+                ret = true;
+        }
+
+        intercept_count--;
+        if (intercept_count == 0)
+        {
+                intercept_clear_setup();
+        }
+
+        return ret;
 }
 
@@ -161 +210 @@
 }
 
-#define CHECK_FOR_FAKE_ERROR_COND(D, S, CALL, FAILRES)  \
+#define CHECK_FOR_FAKE_ERROR_COND(D, S, CALL, FAILRES) \
         if(intercept_count > 0) \
-        {                                                                               \
-                if(intercept_errornow(D, S, CALL))      \
-                {                                                                       \
-                        if(intercept_delay_ms > 0) \
-                        { \
-                                struct timespec tm; \
-                                tm.tv_sec = intercept_delay_ms / 1000; \
-                                tm.tv_nsec = (intercept_delay_ms % 1000) \
-                                        * 1000000; \
-                                while (nanosleep(&tm, &tm) != 0 && \
-                                        errno == EINTR) { } \
-                                intercept_count --; \
-                                if (intercept_count == 0) \
-                                { \
-                                        intercept_clear_setup(); \
-                                } \
-                        } \
-                        else \
-                        { \
-                                errno = intercept_reterr();             \
-                                return FAILRES;                                 \
-                        } \
-                }                                                                       \
+        { \
+                if(intercept_errornow(D, S, CALL)) \
+                { \
+                        errno = intercept_reterr(); \
+                        return FAILRES; \
+                } \
         }
 
@@ -193 +225 @@
         if(intercept_count > 0)
         {
-                if(intercept_syscall == SYS_open && strcmp(path, intercept_filename) == 0)
+                if(intercept_filename != NULL &&
+                        intercept_syscall == SYS_open &&
+                        strcmp(path, intercept_filename) == 0)
                 {
                         errno = intercept_reterr();
@@ -199 +233 @@
                 }
         }
+
 #ifdef PLATFORM_NO_SYSCALL
         int r = TEST_open(path, flags, mode);
@@ -204 +239 @@
         int r = syscall(SYS_open, path, flags, mode);
 #endif
-        if(intercept_count > 0 && intercept_filedes == -1)
+
+        if(intercept_filename != NULL && 
+                intercept_count > 0 && 
+                intercept_filedes == -1)
         {
                 // Right file?
@@ -213 +251 @@
                 }
         }
+
         return r;
 }
@@ -324 +363 @@
 }
 
-static opendir_t*  opendir_real  = NULL;
-static readdir_t*  readdir_real  = NULL;
-static readdir_t*  readdir_hook  = NULL;
-static closedir_t* closedir_real = NULL;
-static lstat_t*    lstat_real    = NULL;
-static lstat_t*    lstat_hook    = NULL;
-static const char* lstat_file    = NULL;
-
 void intercept_setup_readdir_hook(const char *dirname, readdir_t hookfn)
 {
@@ -337 +368 @@
         {
                 dirname = intercept_filename;
+                ASSERT(dirname != NULL);
         }
 
@@ -343 +375 @@
                 TRACE2("readdir hooked to %p for %s\n", hookfn, dirname);
         }
-        else
+        else if (intercept_filename != NULL)
         {
                 TRACE2("readdir unhooked from %p for %s\n", readdir_hook, 
@@ -387 +419 @@
         DIR* r = opendir_real(dirname);
 
-        if(readdir_hook != NULL && intercept_filedes == -1 && 
+        if (readdir_hook != NULL && 
+                intercept_filename != NULL && 
+                intercept_filedes == -1 && 
                 strcmp(intercept_filename, dirname) == 0)
         {