[Nagiosplug-devel] check_dhcp.c incorrectly setting source ip address as siaddr

[Jason Ellison]

nagios-plugins-1.4.15
plugins-root/check_dhcp.c

Sets dhcp server source ip to the next server (siaddr) IP address,
causing -s to fail to operate as expected.

 -s, --serverip=IPADDRESS
    IP address of DHCP server that we must hear from


root at nagios:/usr/local/src/nagios-plugins-1.4.15# ./plugins-root/check_dhcp -v
DHCP socket: 3
Hardware address: 00:22:19:56:99:48
DHCPDISCOVER to 255.255.255.255 port 67
DHCPDISCOVER XID: 275057756 (0x10650C5C)
DHCDISCOVER ciaddr:  0.0.0.0
DHCDISCOVER yiaddr:  0.0.0.0
DHCDISCOVER siaddr:  0.0.0.0
DHCDISCOVER giaddr:  0.0.0.0
send_dhcp_packet result: 548




recv_result_1: 300
recv_result_2: 300
receive_dhcp_packet() result: 300
receive_dhcp_packet() source: 10.10.10.15
Result=OK
DHCPOFFER from IP address 10.10.10.15 via 10.10.10.15
DHCPOFFER XID: 275057756 (0x10650C5C)
DHCPOFFER chaddr: 002219569948
DHCPOFFER ciaddr: 0.0.0.0
DHCPOFFER yiaddr: 10.10.10.166
DHCPOFFER siaddr: 10.10.10.24
DHCPOFFER giaddr: 0.0.0.0
Option: 53 (0x01)
Option: 1 (0x04)
Option: 58 (0x04)
Option: 59 (0x04)
Lease Time: 0 seconds
Renewal Time: 14400 seconds
Rebinding Time: 25200 seconds
Added offer from server @ 10.10.10.15 of IP address 10.10.10.166


No (more) data received (nfound: 0)
Result=ERROR
Total responses seen on the wire: 1
Valid responses for this machine: 1
OK: Received 1 DHCPOFFER(s), max lease time = 0 sec.


17:58:55.805403 IP (tos 0x0, ttl 128, id 20477, offset 0, flags
[none], proto UDP (17), length 328)
    10.10.10.15.67 > 255.255.255.255.68: [udp sum ok] BOOTP/DHCP,
Reply, length 300, xid 0x10650c5c, Flags [none] (0x0000)
          Your-IP 10.10.10.166
          Server-IP 10.10.10.24
          Client-Ethernet-Address 00:22:19:56:99:48
          file "kbox2000.0"
          Vendor-rfc1048 Extensions
            Magic Cookie 0x63825363
            DHCP-Message Option 53, length 1: Offer
            Subnet-Mask Option 1, length 4: 255.255.255.0
            RN Option 58, length 4: 14400
            RB Option 59, length 4: 25200
            Lease-Time Option 51, length 4: 28800
            Server-ID Option 54, length 4: 10.10.10.15
        0x0000:  4500 0148 4ffd 0000 8011 d58f 0a0a 0a0f
        0x0010:  ffff ffff 0043 0044 0134 2e43 0201 0600
        0x0020:  1065 0c5c 0000 0000 0000 0000 0a0a 0aa6
        0x0030:  0a0a 0a18 0000 0000 0022 1956 9948 0000
        0x0040:  0000 0000 0000 0000 0000 0000 0000 0000
        0x0050:  0000 0000 0000 0000 0000 0000 0000 0000
        0x0060:  0000 0000 0000 0000 0000 0000 0000 0000
        0x0070:  0000 0000 0000 0000 0000 0000 0000 0000
        0x0080:  0000 0000 0000 0000 6b62 6f78 3230 3030
        0x0090:  2e30 0000 0000 0000 0000 0000 0000 0000
        0x00a0:  0000 0000 0000 0000 0000 0000 0000 0000
        0x00b0:  0000 0000 0000 0000 0000 0000 0000 0000
        0x00c0:  0000 0000 0000 0000 0000 0000 0000 0000
        0x00d0:  0000 0000 0000 0000 0000 0000 0000 0000
        0x00e0:  0000 0000 0000 0000 0000 0000 0000 0000
        0x00f0:  0000 0000 0000 0000 0000 0000 0000 0000
        0x0100:  0000 0000 0000 0000 6382 5363 3501 0201
        0x0110:  04ff ffff 003a 0400 0038 403b 0400 0062
        0x0120:  7033 0400 0070 8036 040a 0a0a 0fff 0000
        0x0130:  0000 0000 0000 0000 0000 0000 0000 0000
        0x0140:  0000 0000 0000 0000



plugins-root/check_dhcp.c

FIX
                /* If siaddr is non-zero, set "source" to siaddr */
/* don't set the source to next boot server (siaddr) 591 infotek at gmail.com
                if(offer_packet.siaddr.s_addr != 0L){
                        source.sin_addr.s_addr = offer_packet.siaddr.s_addr ;
                        }
*/