diff options
Diffstat (limited to 'lib/intercept')
| -rw-r--r-- | lib/intercept/intercept.cpp | 168 |
1 files changed, 101 insertions, 67 deletions
diff --git a/lib/intercept/intercept.cpp b/lib/intercept/intercept.cpp index a93a5a3b..72260de6 100644 --- a/lib/intercept/intercept.cpp +++ b/lib/intercept/intercept.cpp @@ -74,6 +74,14 @@ int intercept_syscall = 0; off_t intercept_filepos = 0; 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 void intercept_clear_setup() @@ -85,6 +93,8 @@ void intercept_clear_setup() intercept_syscall = 0; intercept_filepos = 0; intercept_delay_ms = 0; + readdir_hook = NULL; + lstat_hook = NULL; } bool intercept_triggered() @@ -94,7 +104,11 @@ bool intercept_triggered() 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; intercept_filedes = -1; @@ -108,9 +122,12 @@ void intercept_setup_error(const char *filename, unsigned int errorafter, int er void intercept_setup_delay(const char *filename, unsigned int delay_after, 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; intercept_filedes = -1; @@ -120,37 +137,69 @@ void intercept_setup_delay(const char *filename, unsigned int delay_after, intercept_filepos = 0; intercept_delay_ms = delay_ms; } + bool intercept_errornow(int d, int size, int syscallnum) { - if(intercept_filedes != -1 && d == intercept_filedes && syscallnum == intercept_syscall) + ASSERT(intercept_count > 0) + + if (intercept_filedes == -1) { - //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! + } + + 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 } - 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; } int intercept_reterr() @@ -160,31 +209,14 @@ int intercept_reterr() return err; } -#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; \ + } \ } extern "C" int @@ -192,18 +224,24 @@ open(const char *path, int flags, mode_t mode) { 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(); return -1; } } + #ifdef PLATFORM_NO_SYSCALL int r = TEST_open(path, flags, mode); #else 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? if(strcmp(intercept_filename, path) == 0) @@ -212,6 +250,7 @@ open(const char *path, int flags, mode_t mode) //printf("Found file to intercept, h = %d\n", r); } } + return r; } @@ -323,26 +362,19 @@ lseek(int fildes, off_t offset, int whence) return r; } -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) { if (hookfn != NULL && dirname == NULL) { dirname = intercept_filename; + ASSERT(dirname != NULL); } if (hookfn != NULL) { 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, intercept_filename); @@ -386,7 +418,9 @@ DIR *opendir(const char *dirname) 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) { intercept_filedes = dirfd(r); |