Summer of Code 2005: improve libalias - part 1 of 2

With the first part of my previous Summer of Code work, we get:

-made libalias modular:

 -support for 'particular' protocols (like ftp/irc/etcetc) is no more
  hardcoded inside libalias, but it's available through external
  modules loadable at runtime

 -modules are available both in kernel (/boot/kernel/alias_*.ko) and
  user land (/lib/libalias_*)

 -protocols/applications modularized are: cuseeme, ftp, irc, nbt, pptp,
  skinny and smedia

-added logging support for kernel side

-cleanup

After a buildworld, do a 'mergemaster -i' to install the file libalias.conf
in /etc or manually copy it.

During startup (and after every HUP signal) user land applications running
the new libalias will try to read a file in /etc called libalias.conf:
that file contains the list of modules to load.

User land applications affected by this commit are ppp and natd:
if libalias.conf is present in /etc you won't notice any difference.

The only kernel land bit affected by this commit is ng_nat:
if you are using ng_nat, and it doesn't correctly handle
ftp/irc/etcetc sessions anymore, remember to kldload
the correspondent module (i.e. kldload alias_ftp).

General information and details about the inner working are available
in the libalias man page under the section 'MODULAR ARCHITECTURE
(AND ipfw(4) SUPPORT)'.

NOTA BENE: this commit affects _ONLY_ libalias, ipfw in-kernel nat
support will be part of the next libalias-related commit.

Approved by: glebius
Reviewed by: glebius, ru

12 files changed, 101 insertions, 13 deletions

diff --git a/lib/libalias/Makefile b/lib/libalias/Makefile
index 465216a9c1c3..1b5ec952e2d5 100644
--- a/lib/libalias/Makefile
+++ b/lib/libalias/Makefile
@@ -1,16 +1,29 @@
+# Copyright 2006 Paolo Pisati <piso@FreeBSD.org>
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+# 1. Redistributions of source code must retain the above copyright
+#    notice, this list of conditions and the following disclaimer.
+# 2. Redistributions in binary form must reproduce the above copyright
+#    notice, this list of conditions and the following disclaimer in the
+#    documentation and/or other materials provided with the distribution.
+#
+# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+# ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+# SUCH DAMAGE.
+#
 # $FreeBSD$
 
-.PATH:	${.CURDIR}/../../sys/netinet/libalias
+SUBDIR=        libalias modules
 
-LIB=	alias
-SHLIBDIR?= /lib
-SHLIB_MAJOR=	5
-MAN=	libalias.3
-SRCS=	alias.c alias_cuseeme.c alias_db.c alias_ftp.c alias_irc.c \
-	alias_nbt.c alias_pptp.c alias_proxy.c alias_skinny.c alias_smedia.c \
-	alias_util.c alias_old.c
-INCS=	alias.h
-WARNS?=	6
-NO_WERROR=
-
-.include <bsd.lib.mk>
+.include <bsd.subdir.mk>
diff --git a/lib/libalias/libalias/Makefile b/lib/libalias/libalias/Makefile
new file mode 100644
index 000000000000..29a234dee369
--- /dev/null
+++ b/lib/libalias/libalias/Makefile
@@ -0,0 +1,13 @@
+# $FreeBSD$
+
+.PATH: ${.CURDIR}/../../../sys/netinet/libalias
+
+LIB=	alias
+SHLIBDIR?= /lib
+SHLIB_MAJOR=	5
+MAN=	libalias.3
+SRCS=	alias.c alias_db.c alias_proxy.c alias_util.c alias_old.c alias_mod.c
+INCS=   alias.h
+WARNS?=	6
+
+.include <bsd.lib.mk>
diff --git a/lib/libalias/modules/Makefile b/lib/libalias/modules/Makefile
new file mode 100644
index 000000000000..e4aa76724816
--- /dev/null
+++ b/lib/libalias/modules/Makefile
@@ -0,0 +1,7 @@
+# $FreeBSD$
+
+.include "../../../sys/modules/libalias/modules/modules.inc"
+
+SUBDIR= ${MODULES}
+
+.include <bsd.subdir.mk>
diff --git a/lib/libalias/modules/Makefile.inc b/lib/libalias/modules/Makefile.inc
new file mode 100644
index 000000000000..df92be4e5a39
--- /dev/null
+++ b/lib/libalias/modules/Makefile.inc
@@ -0,0 +1,7 @@
+# $FreeBSD$
+
+.PATH: ${.CURDIR}/../../../../sys/netinet/libalias
+
+SHLIBDIR?= /lib
+SHLIB_MAJOR=	4
+WARNS?= 1
diff --git a/lib/libalias/modules/cuseeme/Makefile b/lib/libalias/modules/cuseeme/Makefile
new file mode 100644
index 000000000000..482ce93a76ca
--- /dev/null
+++ b/lib/libalias/modules/cuseeme/Makefile
@@ -0,0 +1,6 @@
+# $FreeBSD$
+
+LIB=	alias_cuseeme
+SRCS=	alias_cuseeme.c
+
+.include <bsd.lib.mk>
diff --git a/lib/libalias/modules/dummy/Makefile b/lib/libalias/modules/dummy/Makefile
new file mode 100644
index 000000000000..a79ca855ea61
--- /dev/null
+++ b/lib/libalias/modules/dummy/Makefile
@@ -0,0 +1,6 @@
+# $FreeBSD$
+
+LIB=	alias_dummy
+SRCS=	alias_dummy.c
+
+.include <bsd.lib.mk>
diff --git a/lib/libalias/modules/ftp/Makefile b/lib/libalias/modules/ftp/Makefile
new file mode 100644
index 000000000000..4865fa2ef536
--- /dev/null
+++ b/lib/libalias/modules/ftp/Makefile
@@ -0,0 +1,6 @@
+# $FreeBSD$
+
+LIB=	alias_ftp
+SRCS=	alias_ftp.c
+
+.include <bsd.lib.mk>
diff --git a/lib/libalias/modules/irc/Makefile b/lib/libalias/modules/irc/Makefile
new file mode 100644
index 000000000000..98f4e853605f
--- /dev/null
+++ b/lib/libalias/modules/irc/Makefile
@@ -0,0 +1,6 @@
+# $FreeBSD$
+
+LIB=	alias_irc
+SRCS=	alias_irc.c
+
+.include <bsd.lib.mk>
diff --git a/lib/libalias/modules/nbt/Makefile b/lib/libalias/modules/nbt/Makefile
new file mode 100644
index 000000000000..c26b5d90a669
--- /dev/null
+++ b/lib/libalias/modules/nbt/Makefile
@@ -0,0 +1,6 @@
+# $FreeBSD$
+
+LIB=	alias_nbt
+SRCS=	alias_nbt.c
+
+.include <bsd.lib.mk>
diff --git a/lib/libalias/modules/pptp/Makefile b/lib/libalias/modules/pptp/Makefile
new file mode 100644
index 000000000000..69d8e617a1f1
--- /dev/null
+++ b/lib/libalias/modules/pptp/Makefile
@@ -0,0 +1,6 @@
+# $FreeBSD$
+
+LIB=	alias_pptp
+SRCS=	alias_pptp.c
+
+.include <bsd.lib.mk>
diff --git a/lib/libalias/modules/skinny/Makefile b/lib/libalias/modules/skinny/Makefile
new file mode 100644
index 000000000000..f554e9cec4fd
--- /dev/null
+++ b/lib/libalias/modules/skinny/Makefile
@@ -0,0 +1,6 @@
+# $FreeBSD$
+
+LIB=	alias_skinny
+SRCS=	alias_skinny.c
+
+.include <bsd.lib.mk>
diff --git a/lib/libalias/modules/smedia/Makefile b/lib/libalias/modules/smedia/Makefile
new file mode 100644
index 000000000000..56c4ddd2a29b
--- /dev/null
+++ b/lib/libalias/modules/smedia/Makefile
@@ -0,0 +1,6 @@
+# $FreeBSD$
+
+LIB=	alias_smedia
+SRCS=	alias_smedia.c
+
+.include <bsd.lib.mk>