--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/third_party/libuv/src/unix/tcp.c	Wed Jan 14 19:39:52 2026 -0800
@@ -0,0 +1,673 @@
+/* Copyright Joyent, Inc. and other Node contributors. All rights reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#include "uv.h"
+#include "internal.h"
+
+#include <stdlib.h>
+#include <unistd.h>
+#include <assert.h>
+#include <errno.h>
+
+#include <sys/types.h>
+#include <sys/socket.h>
+
+/* ifaddrs is not implemented on AIX and IBM i PASE */
+#if !defined(_AIX)
+#include <ifaddrs.h>
+#endif
+
+static int maybe_bind_socket(int fd) {
+  union uv__sockaddr s;
+  socklen_t slen;
+
+  slen = sizeof(s);
+  memset(&s, 0, sizeof(s));
+
+  if (getsockname(fd, &s.addr, &slen))
+    return UV__ERR(errno);
+
+  if (s.addr.sa_family == AF_INET)
+    if (s.in.sin_port != 0)
+      return 0;  /* Already bound to a port. */
+
+  if (s.addr.sa_family == AF_INET6)
+    if (s.in6.sin6_port != 0)
+      return 0;  /* Already bound to a port. */
+
+  /* Bind to an arbitrary port. */
+  if (bind(fd, &s.addr, slen))
+    return UV__ERR(errno);
+
+  return 0;
+}
+
+
+static int new_socket(uv_tcp_t* handle, int domain, unsigned int flags) {
+  int sockfd;
+  int err;
+
+  sockfd = uv__socket(domain, SOCK_STREAM, 0);
+  if (sockfd < 0)
+    return sockfd;
+
+  err = uv__stream_open((uv_stream_t*) handle, sockfd, flags);
+  if (err) {
+    uv__close(sockfd);
+    return err;
+  }
+
+  if (flags & UV_HANDLE_BOUND)
+    return maybe_bind_socket(sockfd);
+
+  return 0;
+}
+
+
+static int maybe_new_socket(uv_tcp_t* handle, int domain, unsigned int flags) {
+  int sockfd;
+  int err;
+
+  if (domain == AF_UNSPEC)
+    goto out;
+
+  sockfd = uv__stream_fd(handle);
+  if (sockfd == -1)
+    return new_socket(handle, domain, flags);
+
+  if (!(flags & UV_HANDLE_BOUND))
+    goto out;
+
+  if (handle->flags & UV_HANDLE_BOUND)
+    goto out;  /* Already bound to a port. */
+
+  err = maybe_bind_socket(sockfd);
+  if (err)
+    return err;
+
+out:
+
+  handle->flags |= flags;
+  return 0;
+}
+
+
+int uv_tcp_init_ex(uv_loop_t* loop, uv_tcp_t* tcp, unsigned int flags) {
+  int domain;
+  int err;
+
+  /* Use the lower 8 bits for the domain */
+  domain = flags & 0xFF;
+  if (domain != AF_INET && domain != AF_INET6 && domain != AF_UNSPEC)
+    return UV_EINVAL;
+
+  if (flags & ~0xFF)
+    return UV_EINVAL;
+
+  uv__stream_init(loop, (uv_stream_t*)tcp, UV_TCP);
+
+  /* If anything fails beyond this point we need to remove the handle from
+   * the handle queue, since it was added by uv__handle_init in uv_stream_init.
+   */
+
+  if (domain != AF_UNSPEC) {
+    err = new_socket(tcp, domain, 0);
+    if (err) {
+      uv__queue_remove(&tcp->handle_queue);
+      if (tcp->io_watcher.fd != -1)
+        uv__close(tcp->io_watcher.fd);
+      tcp->io_watcher.fd = -1;
+      return err;
+    }
+  }
+
+  return 0;
+}
+
+
+int uv_tcp_init(uv_loop_t* loop, uv_tcp_t* tcp) {
+  return uv_tcp_init_ex(loop, tcp, AF_UNSPEC);
+}
+
+
+int uv__tcp_bind(uv_tcp_t* tcp,
+                 const struct sockaddr* addr,
+                 unsigned int addrlen,
+                 unsigned int flags) {
+  int err;
+  int on;
+
+  /* Cannot set IPv6-only mode on non-IPv6 socket. */
+  if ((flags & UV_TCP_IPV6ONLY) && addr->sa_family != AF_INET6)
+    return UV_EINVAL;
+
+  err = maybe_new_socket(tcp, addr->sa_family, 0);
+  if (err)
+    return err;
+
+  on = 1;
+  if (setsockopt(tcp->io_watcher.fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)))
+    return UV__ERR(errno);
+
+  if (flags & UV_TCP_REUSEPORT) {
+    err = uv__sock_reuseport(tcp->io_watcher.fd);
+    if (err)
+      return err;
+  }
+
+#ifndef __OpenBSD__
+#ifdef IPV6_V6ONLY
+  if (addr->sa_family == AF_INET6) {
+    on = (flags & UV_TCP_IPV6ONLY) != 0;
+    if (setsockopt(tcp->io_watcher.fd,
+                   IPPROTO_IPV6,
+                   IPV6_V6ONLY,
+                   &on,
+                   sizeof on) == -1) {
+#if defined(__MVS__)
+      if (errno == EOPNOTSUPP)
+        return UV_EINVAL;
+#endif
+      return UV__ERR(errno);
+    }
+  }
+#endif
+#endif
+
+  errno = 0;
+  err = bind(tcp->io_watcher.fd, addr, addrlen);
+  if (err == -1 && errno != EADDRINUSE) {
+    if (errno == EAFNOSUPPORT)
+      /* OSX, other BSDs and SunoS fail with EAFNOSUPPORT when binding a
+       * socket created with AF_INET to an AF_INET6 address or vice versa. */
+      return UV_EINVAL;
+    return UV__ERR(errno);
+  }
+  tcp->delayed_error = (err == -1) ? UV__ERR(errno) : 0;
+
+  tcp->flags |= UV_HANDLE_BOUND;
+  if (addr->sa_family == AF_INET6)
+    tcp->flags |= UV_HANDLE_IPV6;
+
+  return 0;
+}
+
+
+static int uv__is_ipv6_link_local(const struct sockaddr* addr) {
+  const struct sockaddr_in6* a6;
+  uint8_t b[2];
+
+  if (addr->sa_family != AF_INET6)
+    return 0;
+
+  a6 = (const struct sockaddr_in6*) addr;
+  memcpy(b, &a6->sin6_addr, sizeof(b));
+
+  return b[0] == 0xFE && b[1] == 0x80;
+}
+
+
+static int uv__ipv6_link_local_scope_id(void) {
+  struct sockaddr_in6* a6;
+  int rv;
+#if defined(_AIX)
+  /* AIX & IBM i do not have ifaddrs
+   * so fallback to use uv_interface_addresses */
+  uv_interface_address_t* interfaces;
+  uv_interface_address_t* ifa;
+  int count, i;
+
+  if (uv_interface_addresses(&interfaces, &count))
+    return 0;
+
+  rv = 0;
+
+  for (ifa = interfaces; ifa != &interfaces[count]; ifa++) {
+    if (uv__is_ipv6_link_local((struct sockaddr*) &ifa->address)) {
+      rv = ifa->address.address6.sin6_scope_id;
+      break;
+    }
+  }
+
+  uv_free_interface_addresses(interfaces, count);
+
+#else
+  struct ifaddrs* ifa;
+  struct ifaddrs* p;
+
+  if (getifaddrs(&ifa))
+    return 0;
+
+  for (p = ifa; p != NULL; p = p->ifa_next)
+    if (p->ifa_addr != NULL)
+      if (uv__is_ipv6_link_local(p->ifa_addr))
+        break;
+
+  rv = 0;
+  if (p != NULL) {
+    a6 = (struct sockaddr_in6*) p->ifa_addr;
+    rv = a6->sin6_scope_id;
+  }
+
+  freeifaddrs(ifa);
+#endif /* defined(_AIX) */
+
+  return rv;
+}
+
+
+int uv__tcp_connect(uv_connect_t* req,
+                    uv_tcp_t* handle,
+                    const struct sockaddr* addr,
+                    unsigned int addrlen,
+                    uv_connect_cb cb) {
+  struct sockaddr_in6 tmp6;
+  int err;
+  int r;
+
+  assert(handle->type == UV_TCP);
+
+  if (handle->connect_req != NULL)
+    return UV_EALREADY;  /* FIXME(bnoordhuis) UV_EINVAL or maybe UV_EBUSY. */
+
+  if (handle->delayed_error != 0)
+    goto out;
+
+  err = maybe_new_socket(handle,
+                         addr->sa_family,
+                         UV_HANDLE_READABLE | UV_HANDLE_WRITABLE);
+  if (err)
+    return err;
+
+  if (uv__is_ipv6_link_local(addr)) {
+    memcpy(&tmp6, addr, sizeof(tmp6));
+    if (tmp6.sin6_scope_id == 0) {
+      tmp6.sin6_scope_id = uv__ipv6_link_local_scope_id();
+      addr = (void*) &tmp6;
+    }
+  }
+
+  do {
+    errno = 0;
+    r = connect(uv__stream_fd(handle), addr, addrlen);
+  } while (r == -1 && errno == EINTR);
+
+  /* We not only check the return value, but also check the errno != 0.
+   * Because in rare cases connect() will return -1 but the errno
+   * is 0 (for example, on Android 4.3, OnePlus phone A0001_12_150227)
+   * and actually the tcp three-way handshake is completed.
+   */
+  if (r == -1 && errno != 0) {
+    if (errno == EINPROGRESS)
+      ; /* not an error */
+    else if (errno == ECONNREFUSED
+#if defined(__OpenBSD__)
+      || errno == EINVAL
+#endif
+      )
+    /* If we get ECONNREFUSED (Solaris) or EINVAL (OpenBSD) wait until the
+     * next tick to report the error. Solaris and OpenBSD wants to report
+     * immediately -- other unixes want to wait.
+     */
+      handle->delayed_error = UV__ERR(ECONNREFUSED);
+    else
+      return UV__ERR(errno);
+  }
+
+out:
+
+  uv__req_init(handle->loop, req, UV_CONNECT);
+  req->cb = cb;
+  req->handle = (uv_stream_t*) handle;
+  uv__queue_init(&req->queue);
+  handle->connect_req = req;
+
+  uv__io_start(handle->loop, &handle->io_watcher, POLLOUT);
+
+  if (handle->delayed_error)
+    uv__io_feed(handle->loop, &handle->io_watcher);
+
+  return 0;
+}
+
+
+int uv_tcp_open(uv_tcp_t* handle, uv_os_sock_t sock) {
+  int err;
+
+  if (uv__fd_exists(handle->loop, sock))
+    return UV_EEXIST;
+
+  err = uv__nonblock(sock, 1);
+  if (err)
+    return err;
+
+  return uv__stream_open((uv_stream_t*)handle,
+                         sock,
+                         UV_HANDLE_READABLE | UV_HANDLE_WRITABLE);
+}
+
+
+int uv_tcp_getsockname(const uv_tcp_t* handle,
+                       struct sockaddr* name,
+                       int* namelen) {
+
+  if (handle->delayed_error)
+    return handle->delayed_error;
+
+  return uv__getsockpeername((const uv_handle_t*) handle,
+                             getsockname,
+                             name,
+                             namelen);
+}
+
+
+int uv_tcp_getpeername(const uv_tcp_t* handle,
+                       struct sockaddr* name,
+                       int* namelen) {
+
+  if (handle->delayed_error)
+    return handle->delayed_error;
+
+  return uv__getsockpeername((const uv_handle_t*) handle,
+                             getpeername,
+                             name,
+                             namelen);
+}
+
+
+int uv_tcp_close_reset(uv_tcp_t* handle, uv_close_cb close_cb) {
+  int fd;
+  struct linger l = { 1, 0 };
+
+  /* Disallow setting SO_LINGER to zero due to some platform inconsistencies */
+  if (uv__is_stream_shutting(handle))
+    return UV_EINVAL;
+
+  fd = uv__stream_fd(handle);
+  if (0 != setsockopt(fd, SOL_SOCKET, SO_LINGER, &l, sizeof(l))) {
+    if (errno == EINVAL) {
+      /* Open Group Specifications Issue 7, 2018 edition states that
+       * EINVAL may mean the socket has been shut down already.
+       * Behavior observed on Solaris, illumos and macOS. */
+      errno = 0;
+    } else {
+      return UV__ERR(errno);
+    }
+  }
+
+  uv_close((uv_handle_t*) handle, close_cb);
+  return 0;
+}
+
+
+int uv__tcp_listen(uv_tcp_t* tcp, int backlog, uv_connection_cb cb) {
+  unsigned int flags;
+  int err;
+
+  if (tcp->delayed_error)
+    return tcp->delayed_error;
+
+  flags = 0;
+#if defined(__MVS__)
+  /* on zOS the listen call does not bind automatically
+     if the socket is unbound. Hence the manual binding to
+     an arbitrary port is required to be done manually
+  */
+  flags |= UV_HANDLE_BOUND;
+#endif
+  err = maybe_new_socket(tcp, AF_INET, flags);
+  if (err)
+    return err;
+
+  if (listen(tcp->io_watcher.fd, backlog))
+    return UV__ERR(errno);
+
+  tcp->connection_cb = cb;
+  tcp->flags |= UV_HANDLE_BOUND;
+
+  /* Start listening for connections. */
+  tcp->io_watcher.cb = uv__server_io;
+  uv__io_start(tcp->loop, &tcp->io_watcher, POLLIN);
+
+  return 0;
+}
+
+
+int uv__tcp_nodelay(int fd, int on) {
+  if (setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &on, sizeof(on)))
+    return UV__ERR(errno);
+  return 0;
+}
+
+
+#if (defined(UV__SOLARIS_11_4) && !UV__SOLARIS_11_4) || \
+    (defined(__DragonFly__) && __DragonFly_version < 500702)
+/* DragonFlyBSD <500702 and Solaris <11.4 require millisecond units
+ * for TCP keepalive options. */
+#define UV_KEEPALIVE_FACTOR(x) (x *= 1000)
+#else
+#define UV_KEEPALIVE_FACTOR(x)
+#endif
+int uv__tcp_keepalive(int fd, int on, unsigned int delay) {
+  int idle;
+  int intvl;
+  int cnt;
+
+  (void) &idle;
+  (void) &intvl;
+  (void) &cnt;
+
+  if (setsockopt(fd, SOL_SOCKET, SO_KEEPALIVE, &on, sizeof(on)))
+    return UV__ERR(errno);
+
+  if (!on)
+    return 0;
+
+  if (delay < 1)
+    return UV_EINVAL;
+
+#ifdef __sun
+  /* The implementation of TCP keep-alive on Solaris/SmartOS is a bit unusual
+   * compared to other Unix-like systems.
+   * Thus, we need to specialize it on Solaris.
+   *
+   * There are two keep-alive mechanisms on Solaris:
+   * - By default, the first keep-alive probe is sent out after a TCP connection is idle for two hours.
+   * If the peer does not respond to the probe within eight minutes, the TCP connection is aborted.
+   * You can alter the interval for sending out the first probe using the socket option TCP_KEEPALIVE_THRESHOLD
+   * in milliseconds or TCP_KEEPIDLE in seconds.
+   * The system default is controlled by the TCP ndd parameter tcp_keepalive_interval. The minimum value is ten seconds.
+   * The maximum is ten days, while the default is two hours. If you receive no response to the probe,
+   * you can use the TCP_KEEPALIVE_ABORT_THRESHOLD socket option to change the time threshold for aborting a TCP connection.
+   * The option value is an unsigned integer in milliseconds. The value zero indicates that TCP should never time out and
+   * abort the connection when probing. The system default is controlled by the TCP ndd parameter tcp_keepalive_abort_interval.
+   * The default is eight minutes.
+   *
+   * - The second implementation is activated if socket option TCP_KEEPINTVL and/or TCP_KEEPCNT are set.
+   * The time between each consequent probes is set by TCP_KEEPINTVL in seconds.
+   * The minimum value is ten seconds. The maximum is ten days, while the default is two hours.
+   * The TCP connection will be aborted after certain amount of probes, which is set by TCP_KEEPCNT, without receiving response.
+   */
+
+  idle = delay;
+  /* Kernel expects at least 10 seconds. */
+  if (idle < 10)
+    idle = 10;
+  /* Kernel expects at most 10 days. */
+  if (idle > 10*24*60*60)
+    idle = 10*24*60*60;
+
+  UV_KEEPALIVE_FACTOR(idle);
+
+  /* `TCP_KEEPIDLE`, `TCP_KEEPINTVL`, and `TCP_KEEPCNT` were not available on Solaris
+   * until version 11.4, but let's take a chance here. */
+#if defined(TCP_KEEPIDLE) && defined(TCP_KEEPINTVL) && defined(TCP_KEEPCNT)
+  if (setsockopt(fd, IPPROTO_TCP, TCP_KEEPIDLE, &idle, sizeof(idle)))
+    return UV__ERR(errno);
+
+  intvl = 10; /* required at least 10 seconds */
+  UV_KEEPALIVE_FACTOR(intvl);
+  if (setsockopt(fd, IPPROTO_TCP, TCP_KEEPINTVL, &intvl, sizeof(intvl)))
+    return UV__ERR(errno);
+
+  cnt = 1; /* 1 retry, ensure (TCP_KEEPINTVL * TCP_KEEPCNT) is 10 seconds */
+  if (setsockopt(fd, IPPROTO_TCP, TCP_KEEPCNT, &cnt, sizeof(cnt)))
+    return UV__ERR(errno);
+#else
+  /* Fall back to the first implementation of tcp-alive mechanism for older Solaris,
+   * simulate the tcp-alive mechanism on other platforms via `TCP_KEEPALIVE_THRESHOLD` + `TCP_KEEPALIVE_ABORT_THRESHOLD`.
+   */
+  if (setsockopt(fd, IPPROTO_TCP, TCP_KEEPALIVE_THRESHOLD, &idle, sizeof(idle)))
+    return UV__ERR(errno);
+
+  /* Note that the consequent probes will not be sent at equal intervals on Solaris,
+   * but will be sent using the exponential backoff algorithm. */
+  int time_to_abort = 10; /* 10 seconds */
+  UV_KEEPALIVE_FACTOR(time_to_abort);
+  if (setsockopt(fd, IPPROTO_TCP, TCP_KEEPALIVE_ABORT_THRESHOLD, &time_to_abort, sizeof(time_to_abort)))
+    return UV__ERR(errno);
+#endif
+
+#else  /* !defined(__sun) */
+
+  idle = delay;
+  UV_KEEPALIVE_FACTOR(idle);
+#ifdef TCP_KEEPIDLE
+  if (setsockopt(fd, IPPROTO_TCP, TCP_KEEPIDLE, &idle, sizeof(idle)))
+    return UV__ERR(errno);
+#elif defined(TCP_KEEPALIVE)
+  /* Darwin/macOS uses TCP_KEEPALIVE in place of TCP_KEEPIDLE. */
+  if (setsockopt(fd, IPPROTO_TCP, TCP_KEEPALIVE, &idle, sizeof(idle)))
+    return UV__ERR(errno);
+#endif
+
+#ifdef TCP_KEEPINTVL
+  intvl = 1;  /* 1 second; same as default on Win32 */
+  UV_KEEPALIVE_FACTOR(intvl);
+  if (setsockopt(fd, IPPROTO_TCP, TCP_KEEPINTVL, &intvl, sizeof(intvl)))
+    return UV__ERR(errno);
+#endif
+
+#ifdef TCP_KEEPCNT
+  cnt = 10;  /* 10 retries; same as hardcoded on Win32 */
+  if (setsockopt(fd, IPPROTO_TCP, TCP_KEEPCNT, &cnt, sizeof(cnt)))
+    return UV__ERR(errno);
+#endif
+
+#endif  /* !defined(__sun) */
+  return 0;
+}
+
+
+int uv_tcp_nodelay(uv_tcp_t* handle, int on) {
+  int err;
+
+  if (uv__stream_fd(handle) != -1) {
+    err = uv__tcp_nodelay(uv__stream_fd(handle), on);
+    if (err)
+      return err;
+  }
+
+  if (on)
+    handle->flags |= UV_HANDLE_TCP_NODELAY;
+  else
+    handle->flags &= ~UV_HANDLE_TCP_NODELAY;
+
+  return 0;
+}
+
+
+int uv_tcp_keepalive(uv_tcp_t* handle, int on, unsigned int delay) {
+  int err;
+
+  if (uv__stream_fd(handle) != -1) {
+    err =uv__tcp_keepalive(uv__stream_fd(handle), on, delay);
+    if (err)
+      return err;
+  }
+
+  if (on)
+    handle->flags |= UV_HANDLE_TCP_KEEPALIVE;
+  else
+    handle->flags &= ~UV_HANDLE_TCP_KEEPALIVE;
+
+  /* TODO Store delay if uv__stream_fd(handle) == -1 but don't want to enlarge
+   *      uv_tcp_t with an int that's almost never used...
+   */
+
+  return 0;
+}
+
+
+int uv_tcp_simultaneous_accepts(uv_tcp_t* handle, int enable) {
+  return 0;
+}
+
+
+void uv__tcp_close(uv_tcp_t* handle) {
+  uv__stream_close((uv_stream_t*)handle);
+}
+
+
+int uv_socketpair(int type, int protocol, uv_os_sock_t fds[2], int flags0, int flags1) {
+  uv_os_sock_t temp[2];
+  int err;
+#if defined(SOCK_NONBLOCK) && defined(SOCK_CLOEXEC)
+  int flags;
+
+  flags = type | SOCK_CLOEXEC;
+  if ((flags0 & UV_NONBLOCK_PIPE) && (flags1 & UV_NONBLOCK_PIPE))
+    flags |= SOCK_NONBLOCK;
+
+  if (socketpair(AF_UNIX, flags, protocol, temp))
+    return UV__ERR(errno);
+
+  if (flags & UV_FS_O_NONBLOCK) {
+    fds[0] = temp[0];
+    fds[1] = temp[1];
+    return 0;
+  }
+#else
+  if (socketpair(AF_UNIX, type, protocol, temp))
+    return UV__ERR(errno);
+
+  if ((err = uv__cloexec(temp[0], 1)))
+    goto fail;
+  if ((err = uv__cloexec(temp[1], 1)))
+    goto fail;
+#endif
+
+  if (flags0 & UV_NONBLOCK_PIPE)
+    if ((err = uv__nonblock(temp[0], 1)))
+        goto fail;
+  if (flags1 & UV_NONBLOCK_PIPE)
+    if ((err = uv__nonblock(temp[1], 1)))
+      goto fail;
+
+  fds[0] = temp[0];
+  fds[1] = temp[1];
+  return 0;
+
+fail:
+  uv__close(temp[0]);
+  uv__close(temp[1]);
+  return err;
+}