Unverified Commit 76ea4f61 authored by Tommaso Tocci's avatar Tommaso Tocci
Browse files

intercept writev/readv

parent b37423ca

ifs/include/preload/passthrough.hpp

+3 −0
Original line number Diff line number Diff line
@@ -48,9 +48,12 @@ extern void* libc_puts; 
extern void* libc_write;

extern void* libc_pwrite;

extern void* libc_pwrite64;

extern void* libc_writev;



extern void* libc_read;

extern void* libc_pread;

extern void* libc_pread64;

extern void* libc_readv;



extern void* libc_lseek;

extern void* libc_lseek64;

ifs/src/preload/intcp_functions.cpp

+47 −0
Original line number Diff line number Diff line
@@ -520,6 +520,53 @@ ssize_t pwrite64(int fd, const void* buf, size_t count, __off64_t offset) { 
    return (reinterpret_cast<decltype(&pwrite64)>(libc_pwrite64))(fd, buf, count, offset);

}



ssize_t writev(int fd, const struct iovec *iov, int iovcnt) {

    init_passthrough_if_needed();

    if(CTX->initialized()) {

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

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

            auto adafs_fd = CTX->file_map()->get(fd);

            auto pos = adafs_fd->pos(); // retrieve the current offset

            ssize_t written = 0;

            ssize_t ret;

            for (int i = 0; i < iovcnt; ++i){

                auto buf = (iov+i)->iov_base;

                auto count = (iov+i)->iov_len;

                ret = adafs_pwrite_ws(fd, buf, count, pos);

                if(ret == -1) {

                    break;

                }

                written += ret;

                pos += ret;



                if(static_cast<size_t>(ret) < count){

                    break;

                }

            }



            if(written == 0){

                return -1;

            }

            adafs_fd->pos(pos);

            return written;

        }

    }

    return (reinterpret_cast<decltype(&writev)>(libc_writev))(fd, iov, iovcnt);

}



ssize_t readv(int fd, const struct iovec *iov, int iovcnt) {

    init_passthrough_if_needed();

    if(CTX->initialized()) {

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

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

            CTX->log()->error("{}() NOT SUPPORTED", __func__);

            errno = ENOTSUP;

            return -1;

        }

    }

    return (reinterpret_cast<decltype(&readv)>(libc_readv))(fd, iov, iovcnt);

}



ssize_t read(int fd, void* buf, size_t count) {

    init_passthrough_if_needed();

    if(CTX->initialized()) {

ifs/src/preload/passthrough.cpp

+6 −0
Original line number Diff line number Diff line
@@ -52,9 +52,12 @@ void* libc_puts; 
void* libc_write;

void* libc_pwrite;

void* libc_pwrite64;

void* libc_writev;



void* libc_read;

void* libc_pread;

void* libc_pread64;

void* libc_readv;



void* libc_lseek;

void* libc_lseek64;
@@ -126,9 +129,12 @@ void init_passthrough_() { 
    libc_write = dlsym(libc, "write");

    libc_pwrite = dlsym(libc, "pwrite");

    libc_pwrite64 = dlsym(libc, "pwrite64");

    libc_writev = dlsym(libc, "writev");



    libc_read = dlsym(libc, "read");

    libc_pread = dlsym(libc, "pread");

    libc_pread64 = dlsym(libc, "pread64");

    libc_readv = dlsym(libc, "readv");



    libc_lseek = dlsym(libc, "lseek");

    libc_lseek64 = dlsym(libc, "lseek64");