1 files changed, 153 insertions, 0 deletions
diff --git a/libcody/netserver.cc b/libcody/netserver.cc
new file mode 100644
index 00000000000..7e43eb033f4
--- /dev/null
+++ b/libcody/netserver.cc
@@ -0,0 +1,153 @@
+// CODYlib		-*- mode:c++ -*-
+// Copyright (C) 2020 Nathan Sidwell, nathan@acm.org
+// License: Apache v2.0
+
+// Cody
+#include "internal.hh"
+#if CODY_NETWORKING
+// C
+#include <cerrno>
+#include <cstring>
+// OS
+#include <netdb.h>
+#include <unistd.h>
+#include <arpa/inet.h>
+#include <sys/un.h>
+
+#ifndef AI_NUMERICSERV
+#define AI_NUMERICSERV 0
+#endif
+
+// Server-side networking helpers
+
+namespace Cody {
+
+int ListenSocket (char const **e, sockaddr const *addr, socklen_t len,
+		  unsigned backlog)
+{
+  char const *errstr = nullptr;
+
+  int fd = socket (addr->sa_family, SOCK_STREAM, 0);
+  if (fd < 0)
+    {
+      errstr = "creating socket";
+
+    fail:;
+      int err = errno;
+      if (e)
+	*e = errstr;
+      if (fd >= 0)
+	close (fd);
+      errno = err;
+      return -1;
+    }
+
+  if (bind (fd, addr, len) < 0)
+    {
+      errstr = "binding socket";
+      goto fail;
+    }
+
+  if (listen (fd, backlog ? backlog : 17) < 0)
+    {
+      errstr = "listening socket";
+      goto fail;
+    }
+
+  return fd;
+}
+
+int ListenLocal (char const **e, char const *name, unsigned backlog)
+{
+  sockaddr_un addr;
+  size_t len = strlen (name);
+
+  if (len >= sizeof (addr.sun_path))
+    {
+      errno = ENAMETOOLONG;
+      return -1;
+    }
+
+  memset (&addr, 0, offsetof (sockaddr_un, sun_path));
+  addr.sun_family = AF_UNIX;
+  memcpy (addr.sun_path, name, len + 1);
+
+  return ListenSocket (e, (sockaddr *)&addr, sizeof (addr), backlog);
+}
+
+int ListenInet6 (char const **e, char const *name, int port, unsigned backlog)
+{
+  addrinfo *addrs = nullptr;
+  int fd = -1;
+  char const *errstr = nullptr;
+
+  fd = socket (AF_INET6, SOCK_STREAM, 0);
+  if (fd < 0)
+    {
+      errstr = "creating socket";
+
+    fail:;
+      int err = errno;
+      if (e)
+	*e = errstr;
+      if (fd >= 0)
+	close (fd);
+      if (addrs)
+	freeaddrinfo (addrs);
+      errno = err;
+      return -1;
+    }
+
+  addrinfo hints;
+  hints.ai_flags = AI_NUMERICSERV;
+  hints.ai_family = AF_INET6;
+  hints.ai_socktype = SOCK_STREAM;
+  hints.ai_protocol = 0;
+  hints.ai_addrlen = 0;
+  hints.ai_addr = nullptr;
+  hints.ai_canonname = nullptr;
+  hints.ai_next = nullptr;
+
+  /* getaddrinfo requires a port number, but is quite happy to accept
+     invalid ones.  So don't rely on it.  */
+  if (int err = getaddrinfo (name, "0", &hints, &addrs))
+    {
+      errstr = gai_strerror (err);
+      // What's the best errno to set?
+      errno = 0;
+      goto fail;
+    }
+
+  sockaddr_in6 addr;
+  memset (&addr, 0, sizeof (addr));
+  addr.sin6_family = AF_INET6;
+
+  for (struct addrinfo *next = addrs; next; next = next->ai_next)
+    if (next->ai_family == AF_INET6
+	&& next->ai_socktype == SOCK_STREAM)
+      {
+	sockaddr_in6 *in6 = (sockaddr_in6 *)next->ai_addr;
+	in6->sin6_port = htons (port);
+	if (ntohs (in6->sin6_port) != port)
+	  errno = EINVAL;
+	else if (!bind (fd, next->ai_addr, next->ai_addrlen))
+	  goto listen;
+      }
+
+  errstr = "binding socket";
+  goto fail;
+
+ listen:;
+  freeaddrinfo (addrs);
+
+  if (listen (fd, backlog ? backlog : 17) < 0)
+    {
+      errstr = "listening socket";
+      goto fail;
+    }
+
+  return fd;
+}
+
+}
+#endif