build, unit tests, misc fixes

Makefile.am

@@ -0,0 +1,20 @@
+bin_PROGRAMS = choparp
+choparp_SOURCES = src/choparp.c
+man_MANS = src/choparp.8
+
+AM_TESTS_ENVIRONMENT = \
+	AM_BUILDDIR='$(abs_top_builddir)'; \
+	AM_SRCDIR='$(abs_top_srcdir)'; \
+	AM_SHELL='$(SHELL)'; \
+	export AM_BUILDDIR AM_SRCDIR AM_SHELL ;
+
+LOG_DRIVER = \
+	env AM_TAP_AWK='$(AWK)' $(SHELL) $(top_srcdir)/build-aux/tap-driver.sh --comments
+
+TEST_EXTENSIONS = .sh
+
+SH_LOG_DRIVER = $(LOG_DRIVER)
+SH_LOG_COMPILER = $(SHELL)
+
+TESTS = test/linux-ns-unshare.sh
+EXTRA_DIST = $(TESTS) m4/NOTES

README.md

@@ -23,7 +23,17 @@ list.
 Build instructions
 ------------------
 
-Requires libpcap.
+Requires libpcap, autoconf, and automake.
+
+```
+autoreconf -is
+./configure
+make
+make check
+sudo make install
+```
+
+If autotools displease you, it is still possible to build directly.
 
 `gcc -o choparp choparp.c -lpcap`
 

configure.ac

@@ -0,0 +1,46 @@
+# This is based on David A. Wheeler's template for configure.ac
+
+# Process this file with autoconf to produce a configure script.
+
+# Initialize autoconf.
+AC_INIT([choparp], [20150613])
+# Force autoconf to be at least this version number:
+AC_PREREQ([2.68])
+# Safety check - list a source file that wouldn't be in other directories:
+AC_CONFIG_SRCDIR([src/choparp.c])
+# Put configuration results here, so we can easily #include them:
+AC_CONFIG_HEADERS([config.h])
+# Put autotools auxiliary files in subdirectories to reduce clutter:
+AC_CONFIG_AUX_DIR([build-aux])
+AC_CONFIG_MACRO_DIR([m4])
+
+# Enable "automake" to simplify creating makefiles:
+AM_INIT_AUTOMAKE([subdir-objects foreign -Wall -Werror])
+AC_CONFIG_FILES([Makefile])
+
+# TAP test driver support
+AC_PROG_AWK
+AC_REQUIRE_AUX_FILE([tap-driver.sh])
+
+# Checks for programs, e.g., AC_PROG_CC
+AC_PROG_CC
+# only needef for automake < 1.14
+AM_PROG_CC_C_O
+
+# Checks for libraries.
+AC_CHECK_LIB([pcap], [pcap_lookupdev], [], [AC_MSG_ERROR([missing required library libpcap])])
+
+# Checks for header files.
+AC_CHECK_HEADERS([arpa/inet.h fcntl.h netinet/in.h stdlib.h string.h sys/ioctl.h sys/socket.h unistd.h],
+    [], [AC_MSG_ERROR([missing required platform headers])])
+AC_CHECK_HEADER([pcap.h], [], [AC_MSG_ERROR([missing required header pcap.h])])
+
+# Checks for typedefs, structures, and compiler characteristics.
+
+# Checks for library functions.
+AC_FUNC_MALLOC
+AC_FUNC_REALLOC
+AC_CHECK_FUNCS([ftruncate inet_ntop memset socket strchr strtol])
+
+# Do final output.
+AC_OUTPUT

m4/NOTES

@@ -0,0 +1,6 @@
+This directory was added to conform with modern autotools conventions,
+superseding acinclude.m4. Additional local Autoconf macros would
+reside here.
+
+This NOTES file exists to add the directory to git and effectively
+suppresses a spurious warning message.

src/choparp.8

@@ -35,75 +35,101 @@
 .Nd cheap and omitted proxy ARP
 .Sh SYNOPSIS
 .Nm chpoarp
+.Op Fl p Ar file
+.Op Fl v
 .Ar if_name mac_addr
 .Oo Fl Oc Ns Ar net_addr Ns
 .Op / Ns Ar net_mask
 .Ar ...
 .Sh DESCRIPTION
 .Pp
-.Nm choparp 
+.Nm choparp
 is a easy-to-use proxy ARP daemon.
 It watches ARP request packets visible on the interface specified by argument
 .Ar if_name ,
 and sends proxy ARP reply to the sender if the ARP request queries the
 MAC address
 .Pq ethernet hardware address
 for the network specified by
-.Ar net_addr Ns / Ar net_mask .
+.Ar net_addr Ns / Ns Ar net_mask .
 .Pp
+.Bl -tag -width indent
+.It Fl p Ar file
+Save process id to the given file.
+.It Fl v
+Send diagnostic messages to stdout. Repeat to increase verbosity.
+.It Ar if_name
+Network interface on which to listen and respond to ARP requests.
+.It Ar mac_addr
+The MAC address to be published for the specified hosts, in one of three formats.
+.Bl -tag -width indent
+.It Ar xx:xx:xx:xx:xx:xx
+Static value specified as 6 colon-separated byte values in hexadecimal.
+.It Ar vhid: Ns Oo <nnn>|0x<xx> Oc
+Virtual router (VRRP/CARP) address with the final octet (VRID)
+given by decimal value <nnn> or hexadecimal value <xx> .
+.It Ar auto
+Usually,
 .Ar mac_addr
-is th MAC address to be published for the specified hosts.
-It is normally the address of
+is the address of
 .Ar if_name .
-The format of
-.Ar mac_addr
-must be 6 colon-separated bytes of hexadecimal value, such as
-.Ad 00:00:01:01:14:46 .
-The keyword
-.Ad auto
-can also be used to use the address of
+Specify the keyword
+.Sy auto
+to use the address of
 .Ar if_name
-from the system configuration.
-.Pp
-A
-.Xr carp 4
-virtual router address can be specified as
-.Ad vhid:<hex>
+detected from the system configuration.
+.El
 .
-.Pp
-.Ar net_addr
-must be in dotted quad notation
-.Pq for example Ad 133.138.1.134
-or be a 32 bit hexadecimal value starting with
+.It Ar net_addr
+IPv4 address in either dotted quad notation
+.Pq for example Ar 192.0.2.2
+or, BSD-style, as a 32 bit hexadecimal value starting with
 .Dq 0x
-.Pq for example Ad 0x858a0186 .
+.Pq for example Ar 0x858a0186 .
+.It Ar net_mask
+Alone,
+.Ar net_addr
+specifies a single host; to specify an IP range, include a
 .Ar net_mask
-can likewise be speficied as a dotted quad or hexadecimal value,
-or alternatively as a mask length. The following address specifications
-are therefore equivalent:
+in the same way one would specify a subnet.
+Full 32-bit values may be in either dotted-decimal and BSD-style hexadecimal format.
+Prefix lengths may be specified in CIDR notation.
+The following address specifications are equivalent:
 .Bl -item -offset indent
 .It
-.Ad 192.168.98.0/255.255.254.0
+.Ar 192.0.2.0/255.255.254.0
 .It
-.Ad 192.168.98.0/0xfffffe00
+.Ar 0xc0000200/0xfffffe00
 .It
-.Ad 192.168.98.0/23
+.Ar 192.0.2.0/0xfffffe00
+.It
+.Ar 192.0.2.0/23
 .El
 .Pp
-Multiple addresses can be specified.
-Addresses can be
-.Em excluded
-by preceding them with
-.Fl
+Address matches may be either affirmative or negative, with affirmative as the default.
+To exclude an address or range, specify a negative match with a prefix
+.Dq -
+(dash) prefix.
+Multiple matches may be specified, with at least one being affirmative.
+.El
 .Sh EXAMPLES
 If you have network interface
 .Dq ne0
 with MAC address
-.Dq 00:00:01:01:14:16 ,
-and would like to send proxy ARP reply for 192.168.0.64/26,
+.Dq 00:00:5e:00:53:01
+, and would like to send proxy ARP reply for 192.168.0.64/26,
 the argument would be as follows:
 .Bd -literal -offset indent
-choparp ne0 00:00:01:01:14:46 192.168.0.64/255.255.255.192
+choparp ne0 00:00:5e:00:53:01 192.168.0.64/26
+.Ed
+.Pp
+Were
+.Dq ne0
+assigned the IPv4 address 192.168.0.65/26,
+you could additionally exclude the the host address and all-ones and all-zeroes
+broadcast addresses as follows:
+.Bd -literal -offset indent
+choparp ne0 00:00:5e:00:53:01 192.168.0.64/26 -192.168.0.64/31 -192.168.0.127
 .Ed
 .Sh BUGS
 Supports Ethernet interfaces only.