Verified Commit d6c78bdb authored by Tommaso Tocci's avatar Tommaso Tocci
Browse files

intercept symlinkat

parent 427c8625

ifs/include/preload/hooks.hpp

+1 −0
Original line number Diff line number Diff line
@@ -18,6 +18,7 @@ int hook_writev(unsigned long fd, const struct iovec * iov, unsigned long iovcnt 
int hook_pwritev(unsigned long fd, const struct iovec * iov, unsigned long iovcnt,

                 unsigned long pos_l, unsigned long pos_h);

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

int hook_symlinkat(const char * oldname, int newdfd, const char * newname);

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);

ifs/src/preload/hooks.cpp

+33 −0
Original line number Diff line number Diff line
@@ -196,6 +196,39 @@ int hook_unlinkat(int dirfd, const char * cpath, int flags) { 
    }

}



int hook_symlinkat(const char * oldname, int newdfd, const char * newname) {

    CTX->log()->trace("{}() called with oldname '{}', new fd {}, new name '{}'",

                      __func__, oldname, newdfd, newname);



    std::string oldname_resolved;

    if (CTX->relativize_path(oldname, oldname_resolved)) {

        CTX->log()->warn("{}() operation not supported", __func__);

        return -ENOTSUP;

    }



    std::string newname_resolved;

    auto rstatus = CTX->relativize_fd_path(newdfd, newname, newname_resolved, false);

    switch(rstatus) {

        case RelativizeStatus::fd_unknown:

            return syscall_no_intercept(SYS_symlinkat, oldname, newdfd, newname);



        case RelativizeStatus::external:

            return syscall_no_intercept(SYS_symlinkat, oldname, newdfd, newname_resolved.c_str());



        case RelativizeStatus::fd_not_a_dir:

            return -ENOTDIR;



        case RelativizeStatus::internal:

            CTX->log()->warn("{}() operation not supported", __func__);

            return -ENOTSUP;



        default:

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

            return -EINVAL;

    }

}





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

    CTX->log()->trace("{}() called path '{}', mask {}", __func__, path, mask);

    std::string rel_path;

ifs/src/preload/intercept.cpp

+12 −0
Original line number Diff line number Diff line
@@ -120,6 +120,18 @@ static inline int hook(long syscall_number, 
                                AT_REMOVEDIR);

        break;



    case SYS_symlink:

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

                                 AT_FDCWD,

                                 reinterpret_cast<const char *>(arg1));

        break;



    case SYS_symlinkat:

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

                                 static_cast<int>(arg1),

                                 reinterpret_cast<const char *>(arg2));

        break;



    case SYS_access:

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

                              static_cast<int>(arg1));