Unverified Commit 80c1e9b0 authored by Tommaso Tocci's avatar Tommaso Tocci
Browse files

intercept fcntl 

fcntl now is intercept and support the F_GETFD/F_SETFD command.
parent f165baa2

ifs/include/preload/open_file_map.hpp

+1 −0
Original line number Diff line number Diff line
@@ -14,6 +14,7 @@ enum class OpenFile_flags { 
    rdonly,

    wronly,

    rdwr,

    cloexec,

    flag_count // this is purely used as a size variable of this enum class

};

ifs/include/preload/passthrough.hpp

+2 −0
Original line number Diff line number Diff line
@@ -66,6 +66,8 @@ extern void* libc_fdatasync; 
extern void* libc_truncate;

extern void* libc_ftruncate;



extern void* libc_fcntl;



extern void* libc_dup;

extern void* libc_dup2;

extern void* libc_dup3;

ifs/src/preload/intcp_functions.cpp

+41 −0
Original line number Diff line number Diff line
@@ -9,6 +9,7 @@ 
#include <preload/passthrough.hpp>

#include <preload/adafs_functions.hpp>

#include <preload/intcp_functions.hpp>

#include <preload/open_dir.hpp>





using namespace std;
@@ -731,6 +732,46 @@ int ftruncate(int fd, off_t length) __THROW { 
    return (reinterpret_cast<decltype(&ftruncate)>(libc_ftruncate))(fd, length);

}



int fcntl(int fd, int cmd, ...) {

    init_passthrough_if_needed();

    va_list ap;

    void *arg;



    va_start (ap, cmd);

    arg = va_arg (ap, void *);

    va_end (ap);



    if(CTX->initialized()) {

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

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

            switch(cmd) {

                case F_GETFD:

                    CTX->log()->trace("{}() F_GETFD on fd {}", __func__, fd);

                    if(CTX->file_map()->get(fd)

                            ->get_flag(OpenFile_flags::cloexec)) {

                        return FD_CLOEXEC;

                    } else {

                        return 0;

                    }

                case F_SETFD: {

                    va_start (ap, cmd);

                    int flags = va_arg (ap, int);

                    va_end (ap);

                    CTX->log()->trace("{}() [fd: {}, cmd: F_SETFD, FD_CLOEXEC: {}", __func__, fd, (flags & FD_CLOEXEC));

                    CTX->file_map()->get(fd)

                        ->set_flag(OpenFile_flags::cloexec, (flags & FD_CLOEXEC));

                    return 0;

                }

                default:

                    CTX->log()->error("{}() unrecognized command {} on fd {}", __func__, cmd, fd);

                    errno = ENOTSUP;

                    return -1;

            }

        }

    }

    return (reinterpret_cast<decltype(&fcntl)>(libc_fcntl))(fd, cmd, arg);

}



int dup(int oldfd) __THROW {

    init_passthrough_if_needed();

    if(CTX->initialized()) {

ifs/src/preload/passthrough.cpp

+4 −0
Original line number Diff line number Diff line
@@ -71,6 +71,8 @@ void* libc_fdatasync; 
void* libc_truncate;

void* libc_ftruncate;



void* libc_fcntl;



void* libc_dup;

void* libc_dup2;

void* libc_dup3;
@@ -150,6 +152,8 @@ void init_passthrough_() { 
    libc_truncate = dlsym(libc, "truncate");

    libc_ftruncate = dlsym(libc, "ftruncate");



    libc_fcntl = dlsym(libc, "fcntl");



    libc_dup = dlsym(libc, "dup");

    libc_dup2 = dlsym(libc, "dup2");

    libc_dup3 = dlsym(libc, "dup3");