Verified Commit f8eb1bad authored by Tommaso Tocci's avatar Tommaso Tocci
Browse files

intercept faccessat

parent cd24746e

ifs/include/preload/hooks.hpp

+1 −0
Original line number Diff line number Diff line
@@ -19,6 +19,7 @@ int hook_pwritev(unsigned long fd, const struct iovec * iov, unsigned long iovcn 
                 unsigned long pos_l, unsigned long pos_h);

int hook_unlinkat(int dirfd, const char * cpath, int flags);

int hook_access(const char* path, int mask);

int hook_faccessat(int dirfd, const char * cpath, int mode);

int hook_lseek(unsigned int fd, off_t offset, unsigned int whence);

int hook_truncate(const char *path, long length);

int hook_ftruncate(unsigned int fd, unsigned long length);

ifs/src/preload/hooks.cpp

+25 −0
Original line number Diff line number Diff line
@@ -209,6 +209,31 @@ int hook_access(const char* path, int mask) { 
    return syscall_no_intercept(SYS_access, rel_path.c_str(), mask);

}



int hook_faccessat(int dirfd, const char * cpath, int mode) {

    CTX->log()->trace("{}() called with path '{}' dirfd {}, mode {}",

                      __func__, cpath, dirfd, mode);



    std::string resolved;

    auto rstatus = CTX->relativize_fd_path(dirfd, cpath, resolved);

    switch(rstatus) {

        case RelativizeStatus::fd_unknown:

            return syscall_no_intercept(SYS_faccessat, dirfd, cpath, mode);



        case RelativizeStatus::external:

            return syscall_no_intercept(SYS_faccessat, dirfd, resolved.c_str(), mode);



        case RelativizeStatus::fd_not_a_dir:

            return -ENOTDIR;



        case RelativizeStatus::internal:

            return with_errno(adafs_access(resolved, mode));



        default:

            CTX->log()->error("{}() relativize status unknown: {}", __func__);

            return -EINVAL;

    }

}



int hook_lseek(unsigned int fd, off_t offset, unsigned int whence) {

    CTX->log()->trace("{}() called with fd {}, offset {}, whence {}", __func__, fd, offset, whence);

    if (CTX->file_map()->exist(fd)) {

ifs/src/preload/intercept.cpp

+7 −1
Original line number Diff line number Diff line
@@ -115,10 +115,16 @@ static inline int hook(long syscall_number, 
        break;



    case SYS_access:

        *result = hook_access(reinterpret_cast<char*>(arg0),

        *result = hook_access(reinterpret_cast<const char*>(arg0),

                              static_cast<int>(arg1));

        break;



    case SYS_faccessat:

        *result = hook_faccessat(static_cast<int>(arg0),

                                 reinterpret_cast<const char*>(arg1),

                                 static_cast<int>(arg2));

        break;



    case SYS_lseek:

        *result = hook_lseek(static_cast<unsigned int>(arg0),

                             static_cast<off_t>(arg1),