Verified Commit 71606ea7 authored by Tommaso Tocci's avatar Tommaso Tocci
Browse files

Intercept __open{at,}{64,}_2 

`tar` and other gnu coreutils are using __openat{64,}_2 variant.
We need to intercept also that apart of the main `openat` function.

StackOverflow related question [1]

[1]: https://stackoverflow.com/questions/9161116/intercepting-the-openat-system-call-for-gnu-tar
parent 83cc0e40

ifs/include/preload/intcp_functions.hpp

+13 −0
Original line number Diff line number Diff line
@@ -32,6 +32,19 @@ size_t intcp_fwrite(const void *ptr, size_t size, size_t nmemb, FILE *stream); 
strong_alias(intcp_fwrite, fwrite)

strong_alias(intcp_fwrite, fwrite_unlocked)



int intcp_open(const char* path, int flags, ...);

strong_alias(intcp_open, open)

strong_alias(intcp_open, __open_2)

int intcp_open64(const char* path, int flags, ...);

strong_alias(intcp_open64, open64)

strong_alias(intcp_open64, __open64_2)

int intcp_openat(int dirfd, const char *cpath, int flags, ...);

strong_alias(intcp_openat, openat)

strong_alias(intcp_openat, __openat_2)

int intcp_openat64(int dirfd, const char *path, int flags, ...);

strong_alias(intcp_openat64, openat64)

strong_alias(intcp_openat64, __openat64_2)



#endif // IFS_INTCP_FUNCTIONS_HPP



} // extern C

ifs/src/preload/intcp_functions.cpp

+6 −6
Original line number Diff line number Diff line
@@ -21,7 +21,7 @@ void inline notsup_error_32_bit_func(const char* func = __builtin_FUNCTION()) { 
    CTX->log()->error("{}() is NOT SUPPORTED. According to glibc, this function should be called only on 32-bit machine", func);

}



int open(const char* path, int flags, ...) {

int intcp_open(const char* path, int flags, ...) {

    init_passthrough_if_needed();



    mode_t mode = 0;
@@ -45,7 +45,7 @@ int open(const char* path, int flags, ...) { 


#undef open64



int open64(const char* path, int flags, ...) {

int intcp_open64(const char* path, int flags, ...) {

    init_passthrough_if_needed();

    mode_t mode = 0;

    if (flags & O_CREAT) {
@@ -54,10 +54,10 @@ int open64(const char* path, int flags, ...) { 
        mode = va_arg(ap, mode_t);

        va_end(ap);

    }

    return open(path, flags | O_LARGEFILE, mode);

    return intcp_open(path, flags | O_LARGEFILE, mode);

}



int openat(int dirfd, const char *cpath, int flags, ...) {

int intcp_openat(int dirfd, const char *cpath, int flags, ...) {

    init_passthrough_if_needed();



    mode_t mode = 0;
@@ -112,7 +112,7 @@ int openat(int dirfd, const char *cpath, int flags, ...) { 
    return LIBC_FUNC(openat, dirfd, resolved.c_str(), flags, mode);

}



int openat64(int dirfd, const char *path, int flags, ...) {

int intcp_openat64(int dirfd, const char *path, int flags, ...) {

    init_passthrough_if_needed();



    mode_t mode = 0;
@@ -123,7 +123,7 @@ int openat64(int dirfd, const char *path, int flags, ...) { 
        va_end(vl);

    }



    return openat(dirfd, path, flags | O_LARGEFILE, mode);

    return intcp_openat(dirfd, path, flags | O_LARGEFILE, mode);

}



/******  FILE OPS  ******/