auto merge of #9000 : brson/rust/dns, r=anasazi

This exposes a very simple function for resolving host names. There's a lot more that needs to be done, but this is probably enough for servo to get started connecting to real websites again.

Author: bors

src/libstd/rt/io/mod.rs

@@ -269,13 +269,7 @@ pub use self::extensions::WriterByteConversions;
 pub mod file;
 
 /// Synchronous, non-blocking network I/O.
-pub mod net {
-    pub mod tcp;
-    pub mod udp;
-    pub mod ip;
-    #[cfg(unix)]
-    pub mod unix;
-}
+pub mod net;
 
 /// Readers and Writers for memory buffers and strings.
 pub mod mem;

src/libstd/rt/io/net/mod.rs

@@ -0,0 +1,62 @@
+// Copyright 2013 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use option::{Option, Some, None};
+use result::{Ok, Err};
+use rt::io::io_error;
+use rt::io::net::ip::IpAddr;
+use rt::rtio::{IoFactory, IoFactoryObject};
+use rt::local::Local;
+
+pub mod tcp;
+pub mod udp;
+pub mod ip;
+#[cfg(unix)]
+pub mod unix;
+
+/// Simplistic name resolution
+pub fn get_host_addresses(host: &str) -> Option<~[IpAddr]> {
+    /*!
+     * Get the IP addresses for a given host name.
+     *
+     * Raises io_error on failure.
+     */
+
+    let ipaddrs = unsafe {
+        let io: *mut IoFactoryObject = Local::unsafe_borrow();
+        (*io).get_host_addresses(host)
+    };
+
+    match ipaddrs {
+        Ok(i) => Some(i),
+        Err(ioerr) => {
+            io_error::cond.raise(ioerr);
+            None
+        }
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use option::Some;
+    use rt::io::net::ip::Ipv4Addr;
+    use super::*;
+
+    #[test]
+    fn dns_smoke_test() {
+        let ipaddrs = get_host_addresses("localhost").unwrap();
+        let mut found_local = false;
+        let local_addr = &Ipv4Addr(127, 0, 0, 1);
+        for addr in ipaddrs.iter() {
+            found_local = found_local || addr == local_addr;
+        }
+        assert!(found_local);
+    }
+}

src/libstd/rt/rtio.rs

@@ -73,6 +73,7 @@ pub trait IoFactory {
     fn fs_open<P: PathLike>(&mut self, path: &P, fm: FileMode, fa: FileAccess)
         -> Result<~RtioFileStream, IoError>;
     fn fs_unlink<P: PathLike>(&mut self, path: &P) -> Result<(), IoError>;
+    fn get_host_addresses(&mut self, host: &str) -> Result<~[IpAddr], IoError>;
 }
 
 pub trait RtioTcpListener : RtioSocket {

src/libstd/rt/uv/addrinfo.rs

@@ -0,0 +1,178 @@
+// Copyright 2013 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use cast::transmute;
+use cell::Cell;
+use c_str::ToCStr;
+use libc::{c_int, c_void};
+use option::{Option, Some, None};
+use ptr::null;
+use rt::uv::uvll;
+use rt::uv::uvll::UV_GETADDRINFO;
+use rt::uv::{Loop, UvError, NativeHandle};
+use rt::uv::status_to_maybe_uv_error_with_loop;
+use rt::uv::net::UvAddrInfo;
+
+type GetAddrInfoCallback = ~fn(GetAddrInfoRequest, &UvAddrInfo, Option<UvError>);
+
+pub struct GetAddrInfoRequest(*uvll::uv_getaddrinfo_t);
+
+pub struct RequestData {
+    getaddrinfo_cb: Option<GetAddrInfoCallback>,
+}
+
+impl GetAddrInfoRequest {
+    pub fn new() -> GetAddrInfoRequest {
+        let req = unsafe { uvll::malloc_req(UV_GETADDRINFO) };
+        assert!(req.is_not_null());
+        let mut req: GetAddrInfoRequest = NativeHandle::from_native_handle(req);
+        req.install_req_data();
+        return req;
+    }
+
+    pub fn getaddrinfo(&mut self, loop_: &Loop, node: Option<&str>,
+                       service: Option<&str>, hints: Option<UvAddrInfo>,
+                       cb: GetAddrInfoCallback) {
+
+        assert!(node.is_some() || service.is_some());
+
+        let (c_node, c_node_ptr) = match node {
+            Some(n) => {
+                let c_node = n.to_c_str();
+                let c_node_ptr = c_node.with_ref(|r| r);
+                (Some(c_node), c_node_ptr)
+            }
+            None => (None, null())
+        };
+
+        let (c_service, c_service_ptr) = match service {
+            Some(s) => {
+                let c_service = s.to_c_str();
+                let c_service_ptr = c_service.with_ref(|r| r);
+                (Some(c_service), c_service_ptr)
+            }
+            None => (None, null())
+        };
+
+        let cb = Cell::new(cb);
+        let wrapper_cb: GetAddrInfoCallback = |req, addrinfo, err| {
+            // Capture some heap values that need to stay alive for the
+            // getaddrinfo call
+            let _ = &c_node;
+            let _ = &c_service;
+
+            let cb = cb.take();
+            cb(req, addrinfo, err)
+        };
+
+        // XXX: Implement hints
+        assert!(hints.is_none());
+
+        self.get_req_data().getaddrinfo_cb = Some(wrapper_cb);
+
+        unsafe {
+            assert!(0 == uvll::getaddrinfo(loop_.native_handle(),
+                                           self.native_handle(),
+                                           getaddrinfo_cb,
+                                           c_node_ptr,
+                                           c_service_ptr,
+                                           null()));
+        }
+
+        extern "C" fn getaddrinfo_cb(req: *uvll::uv_getaddrinfo_t,
+                                     status: c_int,
+                                     res: *uvll::addrinfo) {
+            let mut req: GetAddrInfoRequest = NativeHandle::from_native_handle(req);
+            let loop_ = req.get_loop();
+            let err = status_to_maybe_uv_error_with_loop(loop_.native_handle(), status);
+            let addrinfo = UvAddrInfo(res);
+            let data = req.get_req_data();
+            (*data.getaddrinfo_cb.get_ref())(req, &addrinfo, err);
+            unsafe {
+                uvll::freeaddrinfo(res);
+            }
+        }
+    }
+
+    fn get_loop(&self) -> Loop {
+        unsafe {
+            Loop {
+                handle: uvll::get_loop_from_fs_req(self.native_handle())
+            }
+        }
+    }
+
+    fn install_req_data(&mut self) {
+        let req = self.native_handle() as *uvll::uv_getaddrinfo_t;
+        let data = ~RequestData {
+            getaddrinfo_cb: None
+        };
+        unsafe {
+            let data = transmute::<~RequestData, *c_void>(data);
+            uvll::set_data_for_req(req, data);
+        }
+    }
+
+    fn get_req_data<'r>(&'r mut self) -> &'r mut RequestData {
+        unsafe {
+            let data = uvll::get_data_for_req(self.native_handle());
+            let data = transmute::<&*c_void, &mut ~RequestData>(&data);
+            return &mut **data;
+        }
+    }
+
+    fn delete(self) {
+        unsafe {
+            let data = uvll::get_data_for_req(self.native_handle());
+            let _data = transmute::<*c_void, ~RequestData>(data);
+            uvll::set_data_for_req(self.native_handle(), null::<()>());
+            uvll::free_req(self.native_handle());
+        }
+    }
+}
+
+impl NativeHandle<*uvll::uv_getaddrinfo_t> for GetAddrInfoRequest {
+    fn from_native_handle(handle: *uvll::uv_getaddrinfo_t) -> GetAddrInfoRequest {
+        GetAddrInfoRequest(handle)
+    }
+    fn native_handle(&self) -> *uvll::uv_getaddrinfo_t {
+        match self { &GetAddrInfoRequest(ptr) => ptr }
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use option::{Some, None};
+    use rt::uv::Loop;
+    use rt::uv::net::accum_sockaddrs;
+    use rt::io::net::ip::{SocketAddr, Ipv4Addr};
+    use super::*;
+
+    #[test]
+    fn getaddrinfo_test() {
+        let mut loop_ = Loop::new();
+        let mut req = GetAddrInfoRequest::new();
+        do req.getaddrinfo(&loop_, Some("localhost"), None, None) |_, addrinfo, _| {
+            let sockaddrs = accum_sockaddrs(addrinfo);
+            let mut found_local = false;
+            let local_addr = &SocketAddr {
+                ip: Ipv4Addr(127, 0, 0, 1),
+                port: 0
+            };
+            for addr in sockaddrs.iter() {
+                found_local = found_local || addr == local_addr;
+            }
+            assert!(found_local);
+        }
+        loop_.run();
+        loop_.close();
+        req.delete();
+    }
+}

src/libstd/rt/uv/file.rs

@@ -139,15 +139,17 @@ impl NativeHandle<*uvll::uv_fs_t> for FsRequest {
         match self { &FsRequest(ptr) => ptr }
     }
 }
-    fn sync_cleanup(loop_: &Loop, result: int)
-          -> Result<int, UvError> {
-        match status_to_maybe_uv_error_with_loop(loop_.native_handle(), result as i32) {
-            Some(err) => Err(err),
-            None => Ok(result)
-        }
+
+fn sync_cleanup(loop_: &Loop, result: int)
+    -> Result<int, UvError> {
+    match status_to_maybe_uv_error_with_loop(loop_.native_handle(), result as i32) {
+        Some(err) => Err(err),
+        None => Ok(result)
     }
+}
 
 pub struct FileDescriptor(c_int);
+
 impl FileDescriptor {
     fn new(fd: c_int) -> FileDescriptor {
         FileDescriptor(fd)

src/libstd/rt/uv/mod.rs

@@ -70,6 +70,7 @@ pub mod net;
 pub mod idle;
 pub mod timer;
 pub mod async;
+pub mod addrinfo;
 
 /// XXX: Loop(*handle) is buggy with destructors. Normal structs
 /// with dtors may not be destructured, but tuple structs can,
@@ -132,7 +133,8 @@ pub type UdpReceiveCallback = ~fn(UdpWatcher, int, Buf, SocketAddr, uint, Option
 pub type UdpSendCallback = ~fn(UdpWatcher, Option<UvError>);
 
 
-/// Callbacks used by StreamWatchers, set as custom data on the foreign handle
+/// Callbacks used by StreamWatchers, set as custom data on the foreign handle.
+/// XXX: Would be better not to have all watchers allocate room for all callback types.
 struct WatcherData {
     read_cb: Option<ReadCallback>,
     write_cb: Option<ConnectionCallback>,

src/libstd/rt/uv/net.rs

@@ -21,6 +21,8 @@ use vec;
 use str;
 use from_str::{FromStr};
 
+pub struct UvAddrInfo(*uvll::addrinfo);
+
 pub enum UvSocketAddr {
     UvIpv4SocketAddr(*sockaddr_in),
     UvIpv6SocketAddr(*sockaddr_in6),
@@ -95,6 +97,28 @@ pub fn uv_socket_addr_to_socket_addr(addr: UvSocketAddr) -> SocketAddr {
     uv_socket_addr_as_socket_addr(addr, util::id)
 }
 
+// Traverse the addrinfo linked list, producing a vector of Rust socket addresses
+pub fn accum_sockaddrs(addr: &UvAddrInfo) -> ~[SocketAddr] {
+    unsafe {
+        let &UvAddrInfo(addr) = addr;
+        let mut addr = addr;
+
+        let mut addrs = ~[];
+        loop {
+            let uvaddr = sockaddr_to_UvSocketAddr((*addr).ai_addr);
+            let rustaddr = uv_socket_addr_to_socket_addr(uvaddr);
+            addrs.push(rustaddr);
+            if (*addr).ai_next.is_not_null() {
+                addr = (*addr).ai_next;
+            } else {
+                break;
+            }
+        }
+
+        return addrs;
+    }
+}
+
 #[cfg(test)]
 #[test]
 fn test_ip4_conversion() {

src/libstd/rt/uv/uvio.rs

@@ -29,7 +29,8 @@ use rt::tube::Tube;
 use rt::task::SchedHome;
 use rt::uv::*;
 use rt::uv::idle::IdleWatcher;
-use rt::uv::net::{UvIpv4SocketAddr, UvIpv6SocketAddr};
+use rt::uv::net::{UvIpv4SocketAddr, UvIpv6SocketAddr, accum_sockaddrs};
+use rt::uv::addrinfo::GetAddrInfoRequest;
 use unstable::sync::Exclusive;
 use super::super::io::support::PathLike;
 use libc::{lseek, off_t, O_CREAT, O_APPEND, O_TRUNC, O_RDWR, O_RDONLY, O_WRONLY,
@@ -596,6 +597,37 @@ impl IoFactory for UvIoFactory {
         assert!(!result_cell.is_empty());
         return result_cell.take();
     }
+
+    fn get_host_addresses(&mut self, host: &str) -> Result<~[IpAddr], IoError> {
+        let result_cell = Cell::new_empty();
+        let result_cell_ptr: *Cell<Result<~[IpAddr], IoError>> = &result_cell;
+        let host_ptr: *&str = &host;
+        let addrinfo_req = GetAddrInfoRequest::new();
+        let addrinfo_req_cell = Cell::new(addrinfo_req);
+        do task::unkillable { // FIXME(#8674)
+            let scheduler: ~Scheduler = Local::take();
+            do scheduler.deschedule_running_task_and_then |_, task| {
+                let task_cell = Cell::new(task);
+                let mut addrinfo_req = addrinfo_req_cell.take();
+                unsafe {
+                    do addrinfo_req.getaddrinfo(self.uv_loop(),
+                                                Some(*host_ptr),
+                                                None, None) |_, addrinfo, err| {
+                        let res = match err {
+                            None => Ok(accum_sockaddrs(addrinfo).map(|addr| addr.ip.clone())),
+                            Some(err) => Err(uv_error_to_io_error(err))
+                        };
+                        (*result_cell_ptr).put_back(res);
+                        let scheduler: ~Scheduler = Local::take();
+                        scheduler.resume_blocked_task_immediately(task_cell.take());
+                    }
+                }
+            }
+        }
+        addrinfo_req.delete();
+        assert!(!result_cell.is_empty());
+        return result_cell.take();
+    }
 }
 
 pub struct UvTcpListener {