Implement IPv6 support.

* am/ipv6.m4: New file.
* examples/sa.c: New file.
* include/mailutils/cidr.h: New file.
* include/mailutils/sockaddr.h: New file.
* libmailutils/cidr/Makefile.am: New file.
* libmailutils/cidr/fromsa.c: New file.
* libmailutils/cidr/fromstr.c: New file.
* libmailutils/cidr/match.c: New file.
* libmailutils/cidr/tosa.c: New file.
* libmailutils/cidr/tostr.c: New file.
* libmailutils/sockaddr/Makefile.am: New file.
* libmailutils/sockaddr/copy.c: New file.
* libmailutils/sockaddr/create.c: New file.
* libmailutils/sockaddr/free.c: New file.
* libmailutils/sockaddr/fromnode.c: New file.
* libmailutils/sockaddr/insert.c: New file.
* libmailutils/sockaddr/ipaddr.c: New file.
* libmailutils/sockaddr/str.c: New file.
* libmailutils/sockaddr/unlink.c: New file.
* libmailutils/sockaddr/url.c: New file.
* libmailutils/tests/cidr.c: New file.

* configure.ac: Call MU_ENABLE_IPV6.
Build libmailutils/sockaddr and libmailutils/cidr.
* examples/.gitignore: Add mblconv and sa
* examples/Makefile.am: (noinst_PROGRAMS): Add sa.
* examples/aclck.c: Use new ACL API.
* examples/echosrv.c: Use new mserv API.
* include/mailutils/Makefile.am (pkginclude_HEADERS): Add cidr.h
and sockaddr.h

* include/mailutils/acl.h (mu_acl_append, mu_acl_prepend)
(mu_acl_insert): Change signatures.
* include/mailutils/debug.h (mu_sockaddr_to_str): Remove proto.
* include/mailutils/mailutils.h: Include cidr.h and sockaddr.h
* include/mailutils/server.h (mu_ip_server_create): Change signature.
(mu_ip_server_get_sockaddr): Likewise.
(mu_m_server_set_default_address)
(mu_m_server_get_default_address): Remove.
* include/mailutils/stream.h (mu_tcp_stream_create_from_sa): New proto.
* include/mailutils/types.hin (mu_cidr, mu_sockaddr): New structs.

* include/mailutils/url.h (MU_URL_IPV6): New flag.
(MU_URL_PARSE_DSLASH_OPTIONAL): New parse flag.

* libmailutils/Makefile.am: Descend into cidr and sockaddr. Link in
libcidr and libsockaddr.
* libmailutils/diag/debug.c (mu_debug_log_begin): Flush mu_strerr.
* libmailutils/diag/errors (MU_ERR_NONAME)
(MU_ERR_BADFLAGS,MU_ERR_SOCKTYPE)
(MU_ERR_FAMILY,MU_ERR_SERVICE): New errors.

* libmailutils/server/acl.c: Rewrite API using mu_cidr.
* libmailutils/server/ipsrv.c: Rewrite AI using mu_sockaddr.
* libmailutils/server/msrv.c: Likewise.
* libmailutils/stream/tcp.c: Likewise.

* libmailutils/tests/.gitignore: Add cidr.
* libmailutils/tests/Makefile.am (noinst_PROGRAMS): Add cidr.
* libmailutils/tests/url-parse.c: Support command line options
to tune the parsing.
* libmailutils/tests/url.at: Pass options to url-parse.
* libmailutils/url/create.c (getkn): Return meaningful error code.
(_mu_url_ctx_parse_host): Accept IPv6 addresses. Set the MU_URL_IPV6
flag if one is given.
(_mu_url_ctx_parse): Unless MU_URL_PARSE_DSLASH_OPTIONAL flag is
given, request :// after scheme part.
(mu_url_create): Add MU_URL_PARSE_DSLASH_OPTIONAL flag.

* libmu_cfg/acl.c: Use new ACL API.
* mu/acl.c: Likewise.

* libproto/mailer/smtp.c (smtp_open): Use mu_tcp_stream_create_from_sa
* libproto/pop/mbox.c (pop_open): Likewise.
* mu/imap.c (com_connect): Likewise.
* mu/pop.c (com_connect): Likewise.
* testsuite/smtpsend.c (main): Likewise.

10 files changed, 853 insertions, 0 deletions

diff --git a/libmailutils/sockaddr/Makefile.am b/libmailutils/sockaddr/Makefile.am
new file mode 100644
index 000000000..dcfb18446
--- /dev/null
+++ b/libmailutils/sockaddr/Makefile.am
@@ -0,0 +1,31 @@
+# GNU Mailutils -- a suite of utilities for electronic mail
+# Copyright (C) 2011 Free Software Foundation, Inc.
+#
+# This library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 3 of the License, or (at your option) any later version.
+#
+# This library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General
+# Public License along with this library.  If not, see
+# <http://www.gnu.org/licenses/>.
+
+noinst_LTLIBRARIES = libsockaddr.la
+
+libsockaddr_la_SOURCES = \
+ copy.c\
+ create.c\
+ free.c\
+ fromnode.c\
+ insert.c\
+ ipaddr.c\
+ str.c\
+ unlink.c\
+ url.c
+
+INCLUDES = @MU_LIB_COMMON_INCLUDES@ -I/libmailutils
diff --git a/libmailutils/sockaddr/copy.c b/libmailutils/sockaddr/copy.c
new file mode 100644
index 000000000..5e28e7857
--- /dev/null
+++ b/libmailutils/sockaddr/copy.c
@@ -0,0 +1,36 @@
+/* GNU Mailutils -- a suite of utilities for electronic mail
+   Copyright (C) 2011 Free Software Foundation, Inc.
+
+   This library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 3 of the License, or (at your option) any later version.
+
+   This library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General
+   Public License along with this library.  If not, see 
+   <http://www.gnu.org/licenses/>. */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <stdlib.h>
+#include <mailutils/sockaddr.h>
+
+int
+mu_sockaddr_copy (struct mu_sockaddr **pnew, struct mu_sockaddr *old)
+{
+  if (!old)
+    {
+      *pnew = NULL;
+      return 0;
+    }
+  return mu_sockaddr_create (pnew, old->addr, old->addrlen);
+}
+
+
diff --git a/libmailutils/sockaddr/create.c b/libmailutils/sockaddr/create.c
new file mode 100644
index 000000000..5b49471e6
--- /dev/null
+++ b/libmailutils/sockaddr/create.c
@@ -0,0 +1,47 @@
+/* GNU Mailutils -- a suite of utilities for electronic mail
+   Copyright (C) 2011 Free Software Foundation, Inc.
+
+   This library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 3 of the License, or (at your option) any later version.
+
+   This library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General
+   Public License along with this library.  If not, see 
+   <http://www.gnu.org/licenses/>. */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <stdlib.h>
+#include <errno.h>
+#include <string.h>
+#include <mailutils/sockaddr.h>
+
+int
+mu_sockaddr_create (struct mu_sockaddr **res,
+		    struct sockaddr *addr, socklen_t len)
+{
+  struct mu_sockaddr *sa;
+
+  sa = calloc (1, sizeof (*sa));
+  if (!sa)
+    return ENOMEM;
+  sa->addr = malloc (len);
+  if (!sa->addr)
+    {
+      free (sa);
+      return ENOMEM;
+    }
+  memcpy (sa->addr, addr, len);
+  sa->addrlen = len;
+  *res = sa;
+  return 0;
+}
+
diff --git a/libmailutils/sockaddr/free.c b/libmailutils/sockaddr/free.c
new file mode 100644
index 000000000..2a31ec36d
--- /dev/null
+++ b/libmailutils/sockaddr/free.c
@@ -0,0 +1,50 @@
+/* GNU Mailutils -- a suite of utilities for electronic mail
+   Copyright (C) 2011 Free Software Foundation, Inc.
+
+   This library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 3 of the License, or (at your option) any later version.
+
+   This library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General
+   Public License along with this library.  If not, see 
+   <http://www.gnu.org/licenses/>. */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <stdlib.h>
+#include <mailutils/sockaddr.h>
+
+void
+mu_sockaddr_free (struct mu_sockaddr *addr)
+{
+  if (!addr)
+    return;
+  free (addr->addr);
+  free (addr->str);
+}
+
+void
+mu_sockaddr_free_list (struct mu_sockaddr *addr)
+{
+  if (!addr)
+    return;
+  if (addr->prev)
+    addr->prev->next = NULL;
+  while (addr)
+    {
+      struct mu_sockaddr *next = addr->next;
+      mu_sockaddr_free (addr);
+      addr = next;
+    }
+}
+
+
+    
diff --git a/libmailutils/sockaddr/fromnode.c b/libmailutils/sockaddr/fromnode.c
new file mode 100644
index 000000000..d79b9523a
--- /dev/null
+++ b/libmailutils/sockaddr/fromnode.c
@@ -0,0 +1,253 @@
+/* GNU Mailutils -- a suite of utilities for electronic mail
+   Copyright (C) 2011 Free Software Foundation, Inc.
+
+   This library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 3 of the License, or (at your option) any later version.
+
+   This library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General
+   Public License along with this library.  If not, see 
+   <http://www.gnu.org/licenses/>. */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <sys/stat.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <netdb.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <errno.h>
+#include <string.h>
+#include <mailutils/sockaddr.h>
+#include <mailutils/url.h>
+#include <mailutils/io.h>
+#include <mailutils/errno.h>
+#include <mailutils/error.h>
+#include <mailutils/nls.h>
+
+static struct mu_sockaddr *
+match_sa (struct mu_sockaddr *list, struct sockaddr *sa, socklen_t len)
+{
+  for (; list; list = list->next)
+    if (len == list->addrlen && memcmp (list->addr, sa, len) == 0)
+      break;
+  return list;
+}
+
+int
+mu_sockaddr_from_node (struct mu_sockaddr **retval, const char *node,
+		       const char *serv, struct mu_sockaddr_hints *mh)
+{
+  int rc;
+
+  if (!mh)
+    {
+      static struct mu_sockaddr_hints nullhints = { 0, AF_UNSPEC };
+      mh = &nullhints;
+    }
+
+  if (mh->family == AF_UNIX)
+    {
+      size_t slen;
+      struct sockaddr_un s_un;
+
+      if (!node)
+	return MU_ERR_NONAME;
+      slen = strlen (node);
+      if (slen >= sizeof s_un.sun_path)
+	return MU_ERR_BUFSPACE;
+
+      s_un.sun_family = AF_UNIX;
+      strcpy(s_un.sun_path, node);
+      return mu_sockaddr_create (retval, (struct sockaddr*) &s_un,
+				 sizeof (s_un));
+    }
+  else 
+#ifdef MAILUTILS_IPV6
+    {
+      struct addrinfo hints;
+      struct addrinfo *res, *ap;
+      char portbuf[64];
+      struct mu_sockaddr *tail = NULL;
+      
+      memset (&hints, 0, sizeof (hints));
+      hints.ai_family = mh->family;
+      hints.ai_socktype = mh->socktype;
+      hints.ai_protocol = mh->protocol;
+
+      if (!node)
+	{
+	  if (mh->flags & MU_AH_PASSIVE)
+	    hints.ai_flags |= AI_PASSIVE;
+	  else
+	    return MU_ERR_NONAME;
+	}
+      if (!serv && mh->port)
+	{
+	  snprintf (portbuf, sizeof portbuf, "%hu", mh->port);
+	  serv = portbuf;
+	}
+	
+      rc = getaddrinfo (node, serv, &hints, &res);
+
+      switch (rc)
+	{
+	case 0:
+	  break;
+
+	case EAI_FAIL:
+	  return MU_ERR_GETHOSTBYNAME;
+	  
+	case EAI_FAMILY:
+	  return MU_ERR_FAMILY;
+
+	case EAI_NONAME:
+	  return MU_ERR_NONAME;
+	  
+	case EAI_SERVICE:
+	  return MU_ERR_SERVICE;
+
+	case EAI_SYSTEM:
+	  mu_error (_("%s:%s: cannot parse address: %s"),
+		    node, serv, mu_strerror (errno));
+	  return errno;
+			
+	case EAI_BADFLAGS:
+	  return MU_ERR_BADFLAGS;
+	  
+	case EAI_SOCKTYPE:
+	  return MU_ERR_SOCKTYPE;
+			
+	case EAI_MEMORY:
+	  return ENOMEM;
+			
+	default:
+	  mu_error ("%s:%s: %s", node, serv, gai_strerror (rc));
+	  return MU_ERR_FAILURE;
+	}
+
+      *retval = NULL;
+      for (ap = res; ap; ap = ap->ai_next)
+	if (mh->family == AF_UNSPEC || ap->ai_addr->sa_family == mh->family)
+	  {
+	    struct mu_sockaddr *sa;
+
+	    if (match_sa (*retval, ap->ai_addr, ap->ai_addrlen))
+	      continue;
+	    rc = mu_sockaddr_create (&sa, ap->ai_addr, ap->ai_addrlen);
+	    if (rc)
+	      {
+		mu_sockaddr_free_list (*retval);
+		freeaddrinfo (res);
+		return rc;
+	      }
+	    if (tail)
+	      mu_sockaddr_insert (tail, sa, 0);
+	    else
+	      *retval = sa;
+	    tail = sa;
+	  }
+      freeaddrinfo (res);
+    }
+#else
+  if (mh->family == AF_INET)
+    {
+      short port;
+      struct hostent *hp;
+      struct mu_sockaddr *tail = NULL;
+      char **p;
+
+      if (serv)
+	{
+	  char *end;
+	  unsigned long n = strtoul (serv, &end, 10);
+
+	  if (*end)
+	    {
+	      struct servent *sp;
+	      const char *proto;
+
+	      if (mh->protocol)
+		{
+		  struct protoent *pp = getprotobynumber (mh->protocol);
+		  if (!pp)
+		    return EINVAL;
+		  proto = pp->p_name;
+		}
+	      else
+		proto = NULL;
+	      
+	      sp = getservbyname (serv, proto);
+	      if (!sp)
+		return MU_ERR_SERVICE;
+	      port = sp->s_port;
+	    }
+	  else if (n == 0 || (port = n) != n)
+	    return MU_ERR_PARSE; /* FIXME: need MU_ERR_RANGE? */
+	}
+      else if (mh->port)
+	port = htons (mh->port);
+      else
+	return MU_ERR_NONAME;
+
+      if (!node)
+	{
+	  struct sockaddr_in s_in;
+
+	  if (!(mh->flags & MU_AH_PASSIVE))
+	    return MU_ERR_NONAME;
+
+	  s_in.sin_family = AF_INET;
+	  s_in.sin_addr.s_addr = INADDR_ANY;
+	  s_in.sin_port = port;
+	  return mu_sockaddr_create (retval, (struct sockaddr*)&s_in,
+				     sizeof (s_in));
+	}
+      
+      hp = gethostbyname (node);
+      if (!hp)
+	return MU_ERR_GETHOSTBYNAME;
+
+      if (hp->h_addrtype != AF_INET || hp->h_length != 4)
+	return MU_ERR_FAMILY;
+
+      for (p = hp->h_addr_list; *p; p++)
+	{
+	  struct mu_sockaddr *sa;
+	  struct sockaddr_in s_in;
+
+	  s_in.sin_family = AF_INET;
+	  memcpy(&s_in.sin_addr, *p, 4);
+	  s_in.sin_port = port;
+	    
+	  rc = mu_sockaddr_create (&sa, (struct sockaddr*)&s_in,
+				   sizeof (s_in));
+	  if (rc)
+	    {
+	      mu_sockaddr_free_list (*retval);
+	      return rc;
+	    }
+	  if (tail)
+	    mu_sockaddr_insert (tail, sa, 0);
+	  else
+	    *retval = sa;
+	  tail = sa;
+	}
+    }
+  else
+    return MU_ERR_FAMILY;
+#endif
+  return 0;
+}
diff --git a/libmailutils/sockaddr/insert.c b/libmailutils/sockaddr/insert.c
new file mode 100644
index 000000000..dbac151c1
--- /dev/null
+++ b/libmailutils/sockaddr/insert.c
@@ -0,0 +1,64 @@
+/* GNU Mailutils -- a suite of utilities for electronic mail
+   Copyright (C) 2011 Free Software Foundation, Inc.
+
+   This library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 3 of the License, or (at your option) any later version.
+
+   This library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General
+   Public License along with this library.  If not, see 
+   <http://www.gnu.org/licenses/>. */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <stdlib.h>
+#include <mailutils/sockaddr.h>
+
+static void
+set_next (struct mu_sockaddr *sp, struct mu_sockaddr *tgt)
+{
+  for (; sp->next; sp = sp->next)
+    ;
+  sp->next = tgt;
+  if (tgt)
+    tgt->prev = sp;
+}
+
+struct mu_sockaddr *
+mu_sockaddr_insert (struct mu_sockaddr *anchor, struct mu_sockaddr *addr,
+		    int before)
+{
+  struct mu_sockaddr *ret = anchor;
+
+  if (!anchor)
+    {
+      addr->prev = NULL;
+      set_next (addr, NULL);
+      return addr;
+    }
+  
+  if (before)
+    {
+      if (anchor->prev)
+	anchor = anchor->prev;
+      else
+	{
+	  addr->prev = NULL;
+	  set_next (addr, anchor);
+	  return addr;
+	}
+    }
+
+  set_next (addr, anchor->next);
+  anchor->next = addr;
+  addr->prev = anchor;
+  return ret;
+}
diff --git a/libmailutils/sockaddr/ipaddr.c b/libmailutils/sockaddr/ipaddr.c
new file mode 100644
index 000000000..6b14b4c29
--- /dev/null
+++ b/libmailutils/sockaddr/ipaddr.c
@@ -0,0 +1,88 @@
+/* GNU Mailutils -- a suite of utilities for electronic mail
+   Copyright (C) 2011 Free Software Foundation, Inc.
+
+   This library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 3 of the License, or (at your option) any later version.
+
+   This library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General
+   Public License along with this library.  If not, see 
+   <http://www.gnu.org/licenses/>. */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <string.h>
+#include <mailutils/sockaddr.h>
+#include <mailutils/cctype.h>
+
+int 
+mu_str_is_ipv4 (const char *addr)
+{
+  int dot_count = 0;
+  int digit_count = 0;
+
+  for (; *addr; addr++)
+    {
+      if (!mu_isascii (*addr))
+	return 0;
+      if (*addr == '.')
+	{
+	  if (++dot_count > 3)
+	    break;
+	  digit_count = 0;
+	}
+      else if (!(mu_isdigit (*addr) && ++digit_count <= 3))
+	return 0;
+    }
+
+  return (dot_count == 3);
+}
+
+int 
+mu_str_is_ipv6 (const char *addr)
+{
+  int col_count = 0; /* Number of colons */
+  int dcol = 0;      /* Did we encounter a double-colon? */
+  int dig_count = 0; /* Number of digits in the last group */
+	
+  for (; *addr; addr++)
+    {
+      if (!mu_isascii (*addr))
+	return 0;
+      else if (mu_isxdigit (*addr))
+	{
+	  if (++dig_count > 4)
+	    return 0;
+	}
+      else if (*addr == ':')
+	{
+	  if (col_count && dig_count == 0 && ++dcol > 1)
+	    return 0;
+	  if (++col_count > 7)
+	    return 0;
+	  dig_count = 0;
+	}
+      else
+	return 0;
+    }
+  
+  return (col_count == 7 || dcol);
+}
+
+int
+mu_str_is_ipaddr (const char *addr)
+{
+  if (strchr (addr, '.'))
+    return mu_str_is_ipv4(addr);
+  else if (strchr (addr, ':'))
+    return mu_str_is_ipv6(addr);
+  return 0;
+}
diff --git a/libmailutils/sockaddr/str.c b/libmailutils/sockaddr/str.c
new file mode 100644
index 000000000..949f21ef9
--- /dev/null
+++ b/libmailutils/sockaddr/str.c
@@ -0,0 +1,109 @@
+/* GNU Mailutils -- a suite of utilities for electronic mail
+   Copyright (C) 2011 Free Software Foundation, Inc.
+
+   This library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 3 of the License, or (at your option) any later version.
+
+   This library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General
+   Public License along with this library.  If not, see 
+   <http://www.gnu.org/licenses/>. */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <sys/stat.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <netdb.h>
+
+#include <mailutils/sockaddr.h>
+#include <mailutils/errno.h>
+#include <mailutils/io.h>
+
+static char *default_sockaddr_text = "[not enogh memory]";
+
+#define S_UN_NAME(sa, salen) \
+	((salen < mu_offsetof(struct sockaddr_un,sun_path)) ?	\
+	  "" : (sa)->sun_path)
+
+int
+mu_sockaddr_format (char **pbuf, const struct sockaddr *sa, socklen_t salen)
+{
+  int rc = MU_ERR_FAILURE;
+  
+  switch (sa->sa_family)
+    {
+#ifdef MAILUTILS_IPV6
+    case AF_INET:
+    case AF_INET6:
+      {
+	char host[NI_MAXHOST];
+	char srv[NI_MAXSERV];
+	if (getnameinfo (sa, salen,
+			 host, sizeof (host), srv, sizeof (srv),
+			 NI_NUMERICHOST|NI_NUMERICSERV) == 0)
+	  {
+	    if (sa->sa_family == AF_INET6)
+	      rc = mu_asprintf (pbuf, "inet6://[%s]:%s", host, srv);
+	    else
+	      rc = mu_asprintf (pbuf, "inet://%s:%s", host, srv);
+	  }
+	else
+	  rc = mu_asprintf (pbuf, "%s://[getnameinfo failed]",
+			    sa->sa_family == AF_INET ?
+			    "inet" : "inet6");
+	break;
+      }
+#else
+    case AF_INET:
+      {
+	struct sockaddr_in *s_in = (struct sockaddr_in *)sa;
+	rc = mu_asprintf (pbuf, "inet://%s:%hu",
+			  inet_ntoa (s_in->sin_addr), s_in->sin_port);
+	break;
+      }
+#endif
+      
+    case AF_UNIX:
+      {
+	struct sockaddr_un *s_un = (struct sockaddr_un *)sa;
+	if (S_UN_NAME (s_un, salen)[0] == 0)
+	  rc = mu_asprintf (pbuf, "unix://[anonymous socket]");
+	else
+	  rc = mu_asprintf (pbuf, "unix://%s", s_un->sun_path);
+	break;
+      }
+
+    default:
+      rc = mu_asprintf (pbuf, "family:%d", sa->sa_family);
+    }
+  return rc;
+}
+
+char *
+mu_sockaddr_to_astr (const struct sockaddr *sa, int salen)
+{
+  char *buf = NULL;
+  mu_sockaddr_format (&buf, sa, salen);
+  return buf;
+}
+
+const char *
+mu_sockaddr_str (struct mu_sockaddr *sa)
+{
+	if (!sa->str && mu_sockaddr_format (&sa->str, sa->addr, sa->addrlen))
+	  return default_sockaddr_text;
+	return sa->str;
+}
+
+
diff --git a/libmailutils/sockaddr/unlink.c b/libmailutils/sockaddr/unlink.c
new file mode 100644
index 000000000..65808f568
--- /dev/null
+++ b/libmailutils/sockaddr/unlink.c
@@ -0,0 +1,45 @@
+/* GNU Mailutils -- a suite of utilities for electronic mail
+   Copyright (C) 2011 Free Software Foundation, Inc.
+
+   This library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 3 of the License, or (at your option) any later version.
+
+   This library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General
+   Public License along with this library.  If not, see 
+   <http://www.gnu.org/licenses/>. */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <stdlib.h>
+#include <mailutils/sockaddr.h>
+
+struct mu_sockaddr *
+mu_sockaddr_unlink (struct mu_sockaddr *addr)
+{
+  struct mu_sockaddr *p;
+
+  if (!addr)
+    return NULL;
+
+  p = addr->prev;
+  if (p)
+    p->next = addr->next;
+  
+  p = addr->next;
+  if (p)
+    p->prev = addr->prev;
+
+  addr->prev = addr->next = NULL;
+  
+  return p;
+}
+
diff --git a/libmailutils/sockaddr/url.c b/libmailutils/sockaddr/url.c
new file mode 100644
index 000000000..0eaf870be
--- /dev/null
+++ b/libmailutils/sockaddr/url.c
@@ -0,0 +1,130 @@
+/* GNU Mailutils -- a suite of utilities for electronic mail
+   Copyright (C) 2011 Free Software Foundation, Inc.
+
+   This library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 3 of the License, or (at your option) any later version.
+
+   This library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General
+   Public License along with this library.  If not, see 
+   <http://www.gnu.org/licenses/>. */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <sys/stat.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <netdb.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <string.h>
+#include <mailutils/sockaddr.h>
+#include <mailutils/url.h>
+#include <mailutils/io.h>
+#include <mailutils/errno.h>
+#include <mailutils/nls.h>
+#include <mailutils/kwd.h>
+
+static struct mu_kwd famtab[] = {
+  { "unix", AF_UNIX },
+  { "local", AF_UNIX },
+  { "inet4", AF_INET },
+#ifdef MAILUTILS_IPV6
+  { "inet6", AF_INET6 },
+  { "inet",  AF_UNSPEC },
+#else
+  { "inet",  AF_INET },
+#endif
+  { NULL }
+};
+
+int
+mu_sockaddr_from_url (struct mu_sockaddr **retval, mu_url_t url,
+		      struct mu_sockaddr_hints *mh)
+{
+  int rc;
+  const char *scheme;
+  const char *node = NULL, *serv = NULL;
+  struct mu_sockaddr_hints hints;
+  
+  if (mh)
+    memcpy (&hints, mh, sizeof (hints));
+  else
+    {
+      memset (&hints, sizeof(hints), 0);
+      hints.family = AF_UNSPEC;
+      hints.socktype = SOCK_STREAM;
+      hints.protocol = IPPROTO_TCP;
+    }
+
+  if (hints.family == AF_UNSPEC)
+    {
+      rc = mu_url_sget_scheme (url, &scheme);
+      if (rc)
+	return rc;
+
+      if (mu_kwd_xlat_name (famtab, scheme, &hints.family))
+	{
+	  if (hints.flags & MU_AH_DETECT_FAMILY)
+	    {
+	      int flags = 0;
+	      
+	      mu_url_get_flags (url, &flags);
+#ifdef MAILUTILS_IPV6
+	      if (flags & MU_URL_IPV6)
+		hints.family = AF_INET6;
+	      else
+#endif
+		if (flags & (MU_URL_HOST|MU_URL_PORT))
+		  hints.family = AF_INET;
+	      else if (flags & MU_URL_PATH)
+		hints.family = AF_UNIX;
+	      else
+		return MU_ERR_FAMILY;
+	    }
+	  else
+	    return MU_ERR_FAMILY;
+	}
+    }
+  
+  if (hints.family == AF_UNIX)
+    {
+      rc = mu_url_sget_path (url, &node);
+      if (rc)
+	{
+	  if (rc == MU_ERR_NOENT)
+	    {
+	      rc = mu_url_sget_host (url, &node);
+	      if (rc == MU_ERR_NOENT)
+		return MU_ERR_NONAME;
+	    }
+	  if (rc)
+	    return rc;
+	}
+    }
+  else
+    {
+#ifdef MAILUTILS_IPV6
+      if (hints.family == AF_UNSPEC)
+	hints.family = mu_url_has_flag (url, MU_URL_IPV6) ? AF_INET6 : AF_INET;
+#endif
+      rc = mu_url_sget_host (url, &node);
+      if (rc && rc != MU_ERR_NOENT)
+	return MU_ERR_NONAME;
+      rc = mu_url_sget_portstr (url, &serv);
+      if (rc && rc != MU_ERR_NOENT)
+	return MU_ERR_NONAME;
+    }
+  return mu_sockaddr_from_node (retval, node, serv, &hints);
+}