solana-ibc: use solana height and timestamp for cf-guest host metadata (

#393)

since the cf-guest light client would exist on rollup, the host metadata
is the solana slot and the timestamp instead of those fetched from the
guest chain since the rollup wouldnt have it.

But if the connection is established to another svm where the guest
chain is used, then the above should be reverted.

solana/solana-ibc/programs/solana-ibc/Cargo.toml

@@ -17,6 +17,7 @@ mocks = ["ibc-testkit"]
 no-entrypoint = []
 no-idl = []
 no-log-ix-name = []
+witness = []
 
 [dependencies]
 anchor-lang.workspace = true

solana/solana-ibc/programs/solana-ibc/src/validation_context.rs

@@ -1,15 +1,15 @@
 use std::str::FromStr;
 use std::time::Duration;
 
-use anchor_lang::prelude::Pubkey;
+use anchor_lang::prelude::{Pubkey, SolanaSysvar};
 use lib::hash::CryptoHash;
+use spl_token::solana_program::clock::Clock;
 
 use crate::client_state::AnyClientState;
 use crate::consensus_state::AnyConsensusState;
 use crate::ibc::{self, ConsensusState};
 use crate::storage::{self, IbcStorage};
 
-
 type Result<T = (), E = ibc::ContextError> = core::result::Result<T, E>;
 
 impl ibc::ValidationContext for IbcStorage<'_, '_> {
@@ -22,7 +22,12 @@ impl ibc::ValidationContext for IbcStorage<'_, '_> {
         &self,
         client_id: &ibc::ClientId,
     ) -> Result<Self::AnyClientState> {
-        Ok(self.borrow().private.client(client_id)?.client_state.get()?)
+        self.borrow()
+            .private
+            .client(client_id)?
+            .client_state
+            .get()
+            .map_err(Into::into)
     }
 
     fn decode_client_state(
@@ -43,13 +48,27 @@ impl ibc::ValidationContext for IbcStorage<'_, '_> {
     }
 
     fn host_height(&self) -> Result<ibc::Height> {
-        let height = u64::from(self.borrow().chain.head()?.block_height);
-        let height = ibc::Height::new(1, height)?;
-        Ok(height)
+        let height = if cfg!(feature = "witness") {
+            Clock::get()
+                .map_err(|e| ibc::ClientError::ClientSpecific {
+                    description: e.to_string(),
+                })?
+                .slot
+        } else {
+            u64::from(self.borrow().chain.head()?.block_height)
+        };
+        Ok(ibc::Height::new(1, height)?)
     }
 
     fn host_timestamp(&self) -> Result<ibc::Timestamp> {
-        let timestamp = self.borrow().chain.head()?.timestamp_ns.get();
+        let timestamp = if cfg!(feature = "witness") {
+            let clock = Clock::get().map_err(|e| {
+                ibc::ClientError::ClientSpecific { description: e.to_string() }
+            })?;
+            clock.unix_timestamp as u64 * 10u64.pow(9)
+        } else {
+            self.borrow().chain.head()?.timestamp_ns.get()
+        };
         ibc::Timestamp::from_nanoseconds(timestamp).map_err(|err| {
             ibc::ClientError::Other { description: err.to_string() }.into()
         })
@@ -296,7 +315,6 @@ impl IbcStorage<'_, '_> {
     }
 }
 
-
 impl ibc::ClientValidationContext for IbcStorage<'_, '_> {
     fn update_meta(
         &self,