1 files changed, 157 insertions, 0 deletions
diff --git a/src/nvim/event/socket.c b/src/nvim/event/socket.c
new file mode 100644
index 0000000000..bdc632abf0
--- /dev/null
+++ b/src/nvim/event/socket.c
@@ -0,0 +1,157 @@
+#include <assert.h>
+#include <stdint.h>
+
+#include <uv.h>
+
+#include "nvim/event/loop.h"
+#include "nvim/event/socket.h"
+#include "nvim/event/rstream.h"
+#include "nvim/event/wstream.h"
+#include "nvim/os/os.h"
+#include "nvim/ascii.h"
+#include "nvim/vim.h"
+#include "nvim/strings.h"
+#include "nvim/path.h"
+#include "nvim/memory.h"
+
+#ifdef INCLUDE_GENERATED_DECLARATIONS
+# include "event/socket.c.generated.h"
+#endif
+
+#define NVIM_DEFAULT_TCP_PORT 7450
+
+void socket_watcher_init(Loop *loop, SocketWatcher *watcher,
+    const char *endpoint, void *data)
+  FUNC_ATTR_NONNULL_ARG(1) FUNC_ATTR_NONNULL_ARG(2) FUNC_ATTR_NONNULL_ARG(3)
+{
+  // Trim to `ADDRESS_MAX_SIZE`
+  if (xstrlcpy(watcher->addr, endpoint, sizeof(watcher->addr))
+      >= sizeof(watcher->addr)) {
+    // TODO(aktau): since this is not what the user wanted, perhaps we
+    // should return an error here
+    WLOG("Address was too long, truncated to %s", watcher->addr);
+  }
+
+  bool tcp = true;
+  char ip[16], *ip_end = xstrchrnul(watcher->addr, ':');
+
+  // (ip_end - addr) is always > 0, so convert to size_t
+  size_t addr_len = (size_t)(ip_end - watcher->addr);
+
+  if (addr_len > sizeof(ip) - 1) {
+    // Maximum length of an IPv4 address buffer is 15 (eg: 255.255.255.255)
+    addr_len = sizeof(ip) - 1;
+  }
+
+  // Extract the address part
+  xstrlcpy(ip, watcher->addr, addr_len + 1);
+  int port = NVIM_DEFAULT_TCP_PORT;
+
+  if (*ip_end == ':') {
+    // Extract the port
+    long lport = strtol(ip_end + 1, NULL, 10); // NOLINT
+    if (lport <= 0 || lport > 0xffff) {
+      // Invalid port, treat as named pipe or unix socket
+      tcp = false;
+    } else {
+      port = (int) lport;
+    }
+  }
+
+  if (tcp) {
+    // Try to parse ip address
+    if (uv_ip4_addr(ip, port, &watcher->uv.tcp.addr)) {
+      // Invalid address, treat as named pipe or unix socket
+      tcp = false;
+    }
+  }
+
+  if (tcp) {
+    uv_tcp_init(&loop->uv, &watcher->uv.tcp.handle);
+    watcher->stream = (uv_stream_t *)&watcher->uv.tcp.handle;
+  } else {
+    uv_pipe_init(&loop->uv, &watcher->uv.pipe.handle, 0);
+    watcher->stream = (uv_stream_t *)&watcher->uv.pipe.handle;
+  }
+
+  watcher->stream->data = watcher;
+  watcher->cb = NULL;
+  watcher->close_cb = NULL;
+}
+
+int socket_watcher_start(SocketWatcher *watcher, int backlog, socket_cb cb)
+  FUNC_ATTR_NONNULL_ALL
+{
+  watcher->cb = cb;
+  int result;
+
+  if (watcher->stream->type == UV_TCP) {
+    result = uv_tcp_bind(&watcher->uv.tcp.handle,
+                         (const struct sockaddr *)&watcher->uv.tcp.addr, 0);
+  } else {
+    result = uv_pipe_bind(&watcher->uv.pipe.handle, watcher->addr);
+  }
+
+  if (result == 0) {
+    result = uv_listen(watcher->stream, backlog, connection_cb);
+  }
+
+  assert(result <= 0);  // libuv should have returned -errno or zero.
+  if (result < 0) {
+    if (result == -EACCES) {
+      // Libuv converts ENOENT to EACCES for Windows compatibility, but if
+      // the parent directory does not exist, ENOENT would be more accurate.
+      *path_tail((char_u *)watcher->addr) = NUL;
+      if (!os_file_exists((char_u *)watcher->addr)) {
+        result = -ENOENT;
+      }
+    }
+    return result;
+  }
+
+  return 0;
+}
+
+int socket_watcher_accept(SocketWatcher *watcher, Stream *stream, void *data)
+{
+  uv_stream_t *client;
+
+  if (watcher->stream->type == UV_TCP) {
+    client = (uv_stream_t *)&stream->uv.tcp;
+    uv_tcp_init(watcher->uv.tcp.handle.loop, (uv_tcp_t *)client);
+  } else {
+    client = (uv_stream_t *)&stream->uv.pipe;
+    uv_pipe_init(watcher->uv.pipe.handle.loop, (uv_pipe_t *)client, 0);
+  }
+
+  int result = uv_accept(watcher->stream, client);
+
+  if (result) {
+    uv_close((uv_handle_t *)client, NULL);
+    return result;
+  }
+
+  stream_init(NULL, stream, -1, client, data);
+  return 0;
+}
+
+void socket_watcher_close(SocketWatcher *watcher, socket_close_cb cb)
+  FUNC_ATTR_NONNULL_ARG(1)
+{
+  watcher->close_cb = cb;
+  uv_close((uv_handle_t *)watcher->stream, close_cb);
+}
+
+static void connection_cb(uv_stream_t *handle, int status)
+{
+  SocketWatcher *watcher = handle->data;
+  watcher->cb(watcher, status, watcher->data);
+}
+
+static void close_cb(uv_handle_t *handle)
+{
+  SocketWatcher *watcher = handle->data;
+  if (watcher->close_cb) {
+    watcher->close_cb(watcher, watcher->data);
+  }
+}