solana/programs/bpf_loader/src/syscalls/sysvar.rs

use {super::*, crate::declare_syscall};

fn get_sysvar<T: std::fmt::Debug + Sysvar + SysvarId + Clone>(
    sysvar: Result<Arc<T>, InstructionError>,
    var_addr: u64,
    check_aligned: bool,
    memory_mapping: &mut MemoryMapping,
    invoke_context: &mut InvokeContext,
) -> Result<u64, EbpfError<BpfError>> {
    invoke_context.get_compute_meter().consume(
        invoke_context
            .get_compute_budget()
            .sysvar_base_cost
            .saturating_add(size_of::<T>() as u64),
    )?;
    let var = translate_type_mut::<T>(memory_mapping, var_addr, check_aligned)?;

    let sysvar: Arc<T> = sysvar.map_err(SyscallError::InstructionError)?;
    *var = T::clone(sysvar.as_ref());

    Ok(SUCCESS)
}

declare_syscall!(
    /// Get a Clock sysvar
    SyscallGetClockSysvar,
    fn call(
        &mut self,
        var_addr: u64,
        _arg2: u64,
        _arg3: u64,
        _arg4: u64,
        _arg5: u64,
        memory_mapping: &mut MemoryMapping,
        result: &mut Result<u64, EbpfError<BpfError>>,
    ) {
        let mut invoke_context = question_mark!(
            self.invoke_context
                .try_borrow_mut()
                .map_err(|_| SyscallError::InvokeContextBorrowFailed),
            result
        );
        *result = get_sysvar(
            invoke_context.get_sysvar_cache().get_clock(),
            var_addr,
            invoke_context.get_check_aligned(),
            memory_mapping,
            &mut invoke_context,
        );
    }
);

declare_syscall!(
    /// Get a EpochSchedule sysvar
    SyscallGetEpochScheduleSysvar,
    fn call(
        &mut self,
        var_addr: u64,
        _arg2: u64,
        _arg3: u64,
        _arg4: u64,
        _arg5: u64,
        memory_mapping: &mut MemoryMapping,
        result: &mut Result<u64, EbpfError<BpfError>>,
    ) {
        let mut invoke_context = question_mark!(
            self.invoke_context
                .try_borrow_mut()
                .map_err(|_| SyscallError::InvokeContextBorrowFailed),
            result
        );
        *result = get_sysvar(
            invoke_context.get_sysvar_cache().get_epoch_schedule(),
            var_addr,
            invoke_context.get_check_aligned(),
            memory_mapping,
            &mut invoke_context,
        );
    }
);

declare_syscall!(
    /// Get a Fees sysvar
    SyscallGetFeesSysvar,
    fn call(
        &mut self,
        var_addr: u64,
        _arg2: u64,
        _arg3: u64,
        _arg4: u64,
        _arg5: u64,
        memory_mapping: &mut MemoryMapping,
        result: &mut Result<u64, EbpfError<BpfError>>,
    ) {
        let mut invoke_context = question_mark!(
            self.invoke_context
                .try_borrow_mut()
                .map_err(|_| SyscallError::InvokeContextBorrowFailed),
            result
        );
        #[allow(deprecated)]
        {
            *result = get_sysvar(
                invoke_context.get_sysvar_cache().get_fees(),
                var_addr,
                invoke_context.get_check_aligned(),
                memory_mapping,
                &mut invoke_context,
            );
        }
    }
);

declare_syscall!(
    /// Get a Rent sysvar
    SyscallGetRentSysvar,
    fn call(
        &mut self,
        var_addr: u64,
        _arg2: u64,
        _arg3: u64,
        _arg4: u64,
        _arg5: u64,
        memory_mapping: &mut MemoryMapping,
        result: &mut Result<u64, EbpfError<BpfError>>,
    ) {
        let mut invoke_context = question_mark!(
            self.invoke_context
                .try_borrow_mut()
                .map_err(|_| SyscallError::InvokeContextBorrowFailed),
            result
        );
        *result = get_sysvar(
            invoke_context.get_sysvar_cache().get_rent(),
            var_addr,
            invoke_context.get_check_aligned(),
            memory_mapping,
            &mut invoke_context,
        );
    }
);