Unverified Commit 0e62229e authored by Tommaso Tocci's avatar Tommaso Tocci
Browse files

Intercept readlinkat

parent 24af9d3b

include/client/intcp_functions.hpp

+4 −0
Original line number Diff line number Diff line
@@ -52,6 +52,10 @@ strong_alias(intcp_symlink, symlink) 
strong_alias(intcp_symlink, __symlink)

int intcp_symlinkat(const char* oldname, int newfd, const char* newname) noexcept;

strong_alias(intcp_symlinkat, symlinkat)

ssize_t intcp_readlink(const char * cpath, char * buf, size_t bufsize) noexcept;

strong_alias(intcp_readlink, readlink)

ssize_t intcp_readlinkat(int dirfd, const char * cpath, char * buf, size_t bufsize) noexcept;

strong_alias(intcp_readlinkat, readlinkat)



int intcp_statvfs(const char *path, struct statvfs *buf) noexcept;

strong_alias(intcp_statvfs, statvfs)

include/client/passthrough.hpp

+2 −0
Original line number Diff line number Diff line
@@ -115,6 +115,8 @@ extern void* libc_link; 
extern void* libc_linkat;

extern void* libc_symlinkat;



extern void* libc_readlinkat;



extern void* libc_realpath;



void init_passthrough_if_needed();

src/client/intcp_functions.cpp

+41 −0
Original line number Diff line number Diff line
@@ -1474,6 +1474,47 @@ int intcp_symlinkat(const char* oldname, int newdfd, const char* newname) noexce 
    }

}



ssize_t intcp_readlink(const char * cpath, char * buf, size_t bufsize) noexcept {

    return intcp_readlinkat(AT_FDCWD, cpath, buf, bufsize);

}



ssize_t intcp_readlinkat(int dirfd, const char * cpath, char * buf, size_t bufsize) noexcept {

    init_passthrough_if_needed();

    if(!CTX->interception_enabled()) {

        return LIBC_FUNC(readlinkat, dirfd, cpath, buf, bufsize);

    }



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

                      __func__, cpath, dirfd, bufsize);



    std::string resolved;

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

    switch(rstatus) {

        case RelativizeStatus::fd_unknown:

            return LIBC_FUNC(readlinkat, dirfd, cpath, buf, bufsize);



        case RelativizeStatus::external:

            return LIBC_FUNC(readlinkat, dirfd, cpath, buf, bufsize);



        case RelativizeStatus::fd_not_a_dir:

            errno = ENOTDIR;

            return -1;



        case RelativizeStatus::internal:

#ifdef HAS_SYMLINKS

            return adafs_readlink(resolved, buf, bufsize);

#else

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

            errno = EINVAL;

            return -1;

#endif

        default:

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

            errno = EINVAL;

            return -1;

    }

}



char *realpath(const char *path, char *resolved_path) {

    init_passthrough_if_needed();

    if(!CTX->interception_enabled()) {

src/client/passthrough.cpp

+4 −0
Original line number Diff line number Diff line
@@ -116,6 +116,8 @@ void* libc_link; 
void* libc_linkat;

void* libc_symlinkat;



void* libc_readlinkat;



void* libc_realpath;
@@ -230,6 +232,8 @@ void init_passthrough_() { 
    libc_linkat = dlsym(libc, "linkat");

    libc_symlinkat = dlsym(libc, "symlinkat");



    libc_readlinkat = dlsym(libc, "readlinkat");



    libc_realpath = dlsym(libc, "realpath");



}