Example policy - full access

{
     "Version": "2012-10-17",
     "Statement": [
         {
             "Sid": "AllowAllS3OperationsOnBucket",
            "Effect": "Allow",
            "Action": "s3:*",
             "Resource": [
                 "arn:aws:s3:::<bucket_name>",
                 "arn:aws:s3:::<bucket_name>/*"
             ],
             "Condition": {
                  "IpAddress": { 
                     "aws:SourceIp": [
                        "<IP 1>", 
                        "<IP 2>"
                   ]
                }
             }
         }
     ]
 }