sysactions/gatherer/interface_information.sh

##
# retrieve interfaces. I prefer using ip if it is
# available, else I fallback to ifconfig... don't know
# how to retrieve this information on other systems.
# This also exports the environment variables.
#
gather_interface_info() {
	[ -z "${NINTERFACES}" ] || return

	local NO=1

	if [ ${IP} ]
	then
		gather_if_info_ip
	else
		if [ ${IFCONFIG} ]
		then
			gather_if_info_ifconfig
		else
			${LOGGER} -p local0.warn 'Found no way to retrieve interface information.'
		fi
	fi

	export NINTERFACES

	while [ ${NO} -le ${NINTERFACES:=0} ]
	do
		export IF${NO}_NAME IF${NO}_MAC IF${NO}_STATE IF${NO}_IPV4 IF${NO}_IPV6
		NO=$((NO+1))
	done
}

##
# get the interface information from the ip tool
#
gather_if_info_ip() {
	eval $(${IP} -o link | ${AWK} '{
		sub(/:/,"",$1);
		ifno=$1;
		sub(/:/,"",$2);
		name=$2;
		classes=classes "net_iface_" name " ";
		for (i=3; i<NF; i++) {
			if ($i == "state") {
				i++; state=$i
			}
			if ($i ~ /link/) {
				i++; mac=$i;
				classes=classes mac " "
			}
		}
		print "IF" no "_NAME=" name ";IF" no "_STATE=" state ";IF" no "_MAC=" mac ";";
		if ("UP" == state) classes=classes mac " ";
		if_numbers=if_numbers " " ifno;
		no+=1
	}
	BEGIN {
		classes="";
		no=1;
		if_numbers=""
	}
	END {
		print "set_class " classes ";";
		print "NINTERFACES=" FNR ";"
		sub(/^ */,"",if_numbers);
		sub(/ *$/,"",if_numbers);
		print "IF_NUMBERS=\"" if_numbers "\";";
	}')

	eval $(${IP} -o addr | ${AWK} -v if_numbers="${IF_NUMBERS}" '{
        sub(/:/,"",$1);
        if_no=$1;
		no=r_if_numbers[if_no];
        if ($3 == "inet") {
            split($4,addr,/[\/]/);
            print "IF" no "_IPV4=\"${IF" no "_IPV4}" addr[1] " \";";
			network(no, addr[1], addr[2]);
            classes=classes addr[1] " "
        }
        if ($3 == "inet6") {
            split($4,addr,/[\/]/);
            print "IF" no "_IPV6=\"${IF" no "_IPV6}" addr[1] " \";";
            classes=classes addr[1] " "
        }
    }
    BEGIN {
        classes="";
		sub(/^ */,"",if_numbers);
		sub(/ *$/,"",if_numbers);
		split(if_numbers,tmp_array,/ /)
		for(no in tmp_array) {
			if_no=tmp_array[no];
			r_if_numbers[if_no]=no;
		}
    }
    END {
        print "set_class " classes ";"
    }
    function network(no, addr, cidr) {
        mask="";
        net="";
        full_octets=cidr/8;
        part_octets=cidr%8;
        split(addr,parts,/\./);
        for(i=1; i<5; i++) {
            if(i-1 < full_octets) {
                mask=mask "255";
                net=net parts[i];
            } else {
                if (i-1 == full_octets) {
                    mpart=256-lshift(1, 8-part_octets);
                    mask=mask mpart;
		    net=net and(parts[i],mpart);
                } else {
                    mask=mask "0";
                    net=net "0";
                }
            }
            if (i < 4) {
                mask=mask ".";
                net=net ".";
            }
        }
		classes=classes net " ";
        print "IF" no "_NETWORK=\"" net "\"; export " name "_NETWORK;";
        print "IF" no "_MASK=\"" mask "\"; export " name "_MASK;";
	}')
}

##
# get interface data via the ifconfig tool
# FIXME This is outdated. It does not set classes at all.
#
gather_if_info_ifconfig() {
	eval $(${IFCONFIG} -a | ${AWK} '
	/ether/ { mac=$2 }
	/inet / { ipv4=ipv4 $2 " " }
	/inet6/ { ipv6=ipv6 $2 " " }
	/^[^ \t]/ {
		if ("" != ipv4 || "" != ipv6) state="UP"; else state="DOWN";
		if ("" != name) {
			print "IF" no "_NAME=" name ";IF" no "_STATE=" state ";IF" no "_MAC=" mac ";" \
				"IF" no "_IPV4=\"${IF" no "_IPV4}" ipv4 " \";" \
				"IF" no "_IPV6=\"${IF" no "_IPV6}" ipv6 " \";";
			no++;
		}
		ipv4=ipv6="";
		sub(/:/,"",$1);
		name=$1
	}
	BEGIN {
		no=1;
	}
	END {
		if ("" != ipv4 || "" != ipv6) state="UP"; else state="DOWN";
		print "IF" no "_NAME=" name ";IF" no "_STATE=" state ";IF" no "_MAC=" mac ";" \
			"IF" no "_IPV4=\"${IF" no "_IPV4}" ipv4 " \";" \
			"IF" no "_IPV6=\"${IF" no "_IPV6}" ipv6 " \";";
		print "NINTERFACES=" no
	}')
}

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