[ nagiosplug-Bugs-3503921 ] check_dhcp.c incorrectly setting source ip address as siaddr
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Bugs item #3503921, was opened at 2012-03-13 16:16 Message generated for change (Comment added) made by armandelli You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=397597&aid=3503921&group_id=29880 Please note that this message will contain a full copy of the comment thread, including the initial issue submission, for this request, not just the latest update. Category: General plugin execution Group: release-1.4.15 Status: Closed Resolution: Accepted Priority: 5 Private: No Submitted By: [email protected] () Assigned to: Holger Weiss (hweiss) Summary: check_dhcp.c incorrectly setting source ip address as siaddr Initial Comment: 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@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 [email protected] if(offer_packet.siaddr.s_addr != 0L){ source.sin_addr.s_addr = offer_packet.siaddr.s_addr ; } */ ---------------------------------------------------------------------- Comment By: andre pinho (armandelli) Date: 2013-05-10 14:56 Message: Hi guys! First timer on the forum, got a quick noob question. I just started working with nagios and programming and would like to know how do I aplly tha fix posted below? I tried executing the file in the nagios plugin folder and it did not work. Thanks a lot! Andre. ---------------------------------------------------------------------- Comment By: Holger Weiss (hweiss) Date: 2012-06-13 15:44 Message: This problem is now fixed in Git. Thank you for your report. ---------------------------------------------------------------------- Comment By: Jason Ellison (infotek411) Date: 2012-04-12 22:30 Message: the following is a more correct in dealing with the 0x00 PAD octets... if value = 0 skip one octet else it was just an unknown value and you can skip option_length. @@ -870,9 +865,9 @@ memcpy(&serv_ident.s_addr, &offer_packet->options[x],sizeof(serv_ident.s_addr)); break; } - - /* skip option data we're ignoring */ - if(option_type!=DHCP_OPTION_REBINDING_TIME) + if(option_type=0) + x+=1; + else x+=option_length; } ---------------------------------------------------------------------- Comment By: Jason Ellison (infotek411) Date: 2012-04-12 21:07 Message: That did solve the abort issue when parsing the options, which in turn allowed serv_ident to be set. It brought out a bug in the OPTION parsing in the switch while in verbose mode I also got rid of the source = siaddr. --- ./a/plugins-root/check_dhcp.c 2010-07-27 15:47:16.000000000 -0500 +++ ./b/plugins-root/check_dhcp.c 2012-04-12 22:58:56.000000000 -0500 @@ -141,7 +141,7 @@ u_int16_t flags; /* flags */ struct in_addr ciaddr; /* IP address of this machine (if we already have one) */ struct in_addr yiaddr; /* IP address of this machine (offered by the DHCP server) */ - struct in_addr siaddr; /* IP address of DHCP server */ + struct in_addr siaddr; /* IP address of next server */ struct in_addr giaddr; /* IP address of DHCP relay */ unsigned char chaddr [MAX_DHCP_CHADDR_LENGTH]; /* hardware address of this machine */ char sname [MAX_DHCP_SNAME_LENGTH]; /* name of DHCP server */ @@ -587,11 +587,6 @@ /* Save a copy of "source" into "via" even if it's via itself */ memcpy(&via,&source,sizeof(source)) ; - /* If siaddr is non-zero, set "source" to siaddr */ - if(offer_packet.siaddr.s_addr != 0L){ - source.sin_addr.s_addr = offer_packet.siaddr.s_addr ; - } - if(verbose){ printf(_("DHCPOFFER from IP address %s"),inet_ntoa(source.sin_addr)); printf(_(" via %s\n"),inet_ntoa(via.sin_addr)); @@ -840,7 +835,7 @@ for(x=4;x<MAX_DHCP_OPTIONS_LENGTH;){ /* end of options (0 is really just a pad, but bail out anyway) */ - if((int)offer_packet->options[x]==-1 || (int)offer_packet->options[x]==0) + if((int)offer_packet->options[x]==-1) break; /* get option type */ @@ -870,10 +865,7 @@ memcpy(&serv_ident.s_addr, &offer_packet->options[x],sizeof(serv_ident.s_addr)); break; } - - /* skip option data we're ignoring */ - if(option_type!=DHCP_OPTION_REBINDING_TIME) - x+=option_length; + x+=option_length; } if(verbose){ @@ -903,9 +895,9 @@ * the next bootstrap service (e.g., delivery of an operating system * executable image). A DHCP server always returns its own address in * the 'server identifier' option." 'serv_ident' is the 'server - * identifier' option, 'source' is the 'siaddr' field or (if 'siaddr' - * wasn't available) the IP address we received the DHCPOFFER from. If - * 'serv_ident' isn't available for some reason, we use 'source'. + * identifier' option, 'source' is the IP address we received the + * DHCPOFFER from. If 'serv_ident' isn't available for some reason, we + * use 'source'. */ new_offer->server_address=serv_ident.s_addr?serv_ident:source; new_offer->offered_address=offer_packet->yiaddr; ---------------------------------------------------------------------- Comment By: Holger Weiss (hweiss) Date: 2012-04-11 11:04 Message: Thank you very much. I've attached a patch, could you check whether it solves the problem? ---------------------------------------------------------------------- Comment By: Jason Ellison (infotek411) Date: 2012-04-10 21:02 Message: gdb inspecting the local variables before it is source is clobbered by siaddr Breakpoint 1, get_dhcp_offer (sock=6) at check_dhcp.c:591 591 if(offer_packet.siaddr.s_addr != 0L){ after source is clobbered by siaddr Breakpoint 2, get_dhcp_offer (sock=6) at check_dhcp.c:595 595 if(verbose){ and before and after the conditional expression that sets source Breakpoint 3, add_dhcp_offer (source={s_addr = 403311114}, offer_packet=0xbf9d7460) at check_dhcp.c:910 910 new_offer->server_address=serv_ident.s_addr?serv_ident:source; Breakpoint 4, add_dhcp_offer (source={s_addr = 403311114}, offer_packet=0xbf9d7460) at check_dhcp.c:917 917 if(verbose){ # gdb ./plugins-root/check_dhcp GNU gdb 6.8 Copyright (C) 2008 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html> This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law. Type "show copying" and "show warranty" for details. This GDB was configured as "i486-slackware-linux"... (gdb) set args -v (gdb) break 590 Breakpoint 1 at 0x804a808: file check_dhcp.c, line 590. (gdb) break 595 Breakpoint 2 at 0x804a815: file check_dhcp.c, line 595. (gdb) break 910 Breakpoint 3 at 0x8049e56: file check_dhcp.c, line 910. (gdb) break 917 Breakpoint 4 at 0x8049e83: file check_dhcp.c, line 917. (gdb) start Breakpoint 5 at 0x804aeb8: file check_dhcp.c, line 262. Starting program: /usr/local/src/nagios-plugins-1.4.15/plugins-root/check_dhcp -v [Thread debugging using libthread_db enabled] [New Thread 0xb7e466c0 (LWP 21323)] [Switching to Thread 0xb7e466c0 (LWP 21323)] main (argc=2, argv=0xbfd162c4) at check_dhcp.c:262 262 setlocale (LC_ALL, ""); (gdb) continue Continuing. DHCP socket: 6 Hardware address: 00:22:19:56:99:48 DHCPDISCOVER to 255.255.255.255 port 67 DHCPDISCOVER XID: 8454682 (0x81021A) 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 Breakpoint 1, get_dhcp_offer (sock=6) at check_dhcp.c:591 591 if(offer_packet.siaddr.s_addr != 0L){ (gdb) info locals offer_packet = {op = 2 '\002', htype = 1 '\001', hlen = 6 '\006', hops = 0 '\0', xid = 436371712, secs = 0, flags = 0, ciaddr = {s_addr = 0}, yiaddr = {s_addr = 1879706122}, siaddr = {s_addr = 403311114}, giaddr = {s_addr = 0}, chaddr = "\000\"\031V\231H\000\000\000\000\000\000\000\000\000", sname = '\0' <repeats 63 times>, file = "kbox2000.0", '\0' <repeats 117 times>, options = "c\202Sc5\001\002\001\004ÿÿÿ\000:\004\000\0008@;\004\000\000bp3\004\000\000p\2006\004\n\n\n\017ÿ", '\0' <repeats 273 times>} source = {sin_family = 2, sin_port = 17152, sin_addr = {s_addr = 252316170}, sin_zero = "\000\000\000\000\000\000\000"} via = {sin_family = 2, sin_port = 17152, sin_addr = {s_addr = 252316170}, sin_zero = "\000\000\000\000\000\000\000"} result = 0 responses = 1 x = 6 start_time = 1334116496 current_time = <value optimized out> (gdb) continue Continuing. Breakpoint 2, get_dhcp_offer (sock=6) at check_dhcp.c:595 595 if(verbose){ (gdb) info locals offer_packet = {op = 2 '\002', htype = 1 '\001', hlen = 6 '\006', hops = 0 '\0', xid = 436371712, secs = 0, flags = 0, ciaddr = {s_addr = 0}, yiaddr = {s_addr = 1879706122}, siaddr = {s_addr = 403311114}, giaddr = {s_addr = 0}, chaddr = "\000\"\031V\231H\000\000\000\000\000\000\000\000\000", sname = '\0' <repeats 63 times>, file = "kbox2000.0", '\0' <repeats 117 times>, options = "c\202Sc5\001\002\001\004ÿÿÿ\000:\004\000\0008@;\004\000\000bp3\004\000\000p\2006\004\n\n\n\017ÿ", '\0' <repeats 273 times>} source = {sin_family = 2, sin_port = 17152, sin_addr = {s_addr = 403311114}, sin_zero = "\000\000\000\000\000\000\000"} via = {sin_family = 2, sin_port = 17152, sin_addr = {s_addr = 252316170}, sin_zero = "\000\000\000\000\000\000\000"} result = 0 responses = 1 x = 6 start_time = 1334116496 current_time = <value optimized out> (gdb) continue Continuing. DHCPOFFER from IP address 10.10.10.24 via 10.10.10.15 DHCPOFFER XID: 8454682 (0x81021A) DHCPOFFER chaddr: 002219569948 DHCPOFFER ciaddr: 0.0.0.0 DHCPOFFER yiaddr: 10.10.10.112 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 Breakpoint 3, add_dhcp_offer (source={s_addr = 403311114}, offer_packet=0xbfd15fa0) at check_dhcp.c:910 910 new_offer->server_address=serv_ident.s_addr?serv_ident:source; (gdb) info locals x = <value optimized out> option_type = 25200 option_length = 4 serv_ident = {s_addr = 0} (gdb) continue Continuing. Breakpoint 4, add_dhcp_offer (source={s_addr = 403311114}, offer_packet=0xbfd15fa0) at check_dhcp.c:917 917 if(verbose){ (gdb) info locals x = <value optimized out> option_type = 25200 option_length = 4 serv_ident = {s_addr = 0} (gdb) continue Continuing. Added offer from server @ 10.10.10.24 of IP address 10.10.10.112 Total responses seen on the wire: 1 Valid responses for this machine: 1 OK: Received 1 DHCPOFFER(s), max lease time = 0 sec. Program exited normally. (gdb) quit tcpdump (saved the pcap also) root@nagios:/usr/local/src/nagios-plugins-1.4.15# tcpdump -nvvvxX -r check_dhcp.pcap reading from file check_dhcp.pcap, link-type EN10MB (Ethernet) 22:28:36.929010 IP (tos 0x0, ttl 64, id 0, offset 0, flags [DF], proto UDP (17), length 576) 10.10.10.26.68 > 255.255.255.255.67: [bad udp cksum e6d!] BOOTP/DHCP, Request from 00:22:19:56:99:48, length 548, xid 0x6247da8b, secs 65280, Flags [Broadcast] (0x8000) Client-Ethernet-Address 00:22:19:56:99:48 Vendor-rfc1048 Extensions Magic Cookie 0x63825363 DHCP-Message Option 53, length 1: Discover END Option 255, length 0 PAD Option 0, length 0, occurs 304 0x0000: 4500 0240 0000 4000 4011 248a 0a0a 0a1a E..@..@.@.$..... 0x0010: ffff ffff 0044 0043 022c 1661 0101 0600 .....D.C.,.a.... 0x0020: 6247 da8b ff00 8000 0000 0000 0000 0000 bG.............. 0x0030: 0000 0000 0000 0000 0022 1956 9948 0000 .........".V.H.. 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 0000 0000 0000 0000 ................ 0x0090: 0000 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 01ff ........c.Sc5... 0x0110: 0000 0000 0000 0000 0000 0000 0000 0000 ................ 0x0120: 0000 0000 0000 0000 0000 0000 0000 0000 ................ 0x0130: 0000 0000 0000 0000 0000 0000 0000 0000 ................ 0x0140: 0000 0000 0000 0000 0000 0000 0000 0000 ................ 0x0150: 0000 0000 0000 0000 0000 0000 0000 0000 ................ 0x0160: 0000 0000 0000 0000 0000 0000 0000 0000 ................ 0x0170: 0000 0000 0000 0000 0000 0000 0000 0000 ................ 0x0180: 0000 0000 0000 0000 0000 0000 0000 0000 ................ 0x0190: 0000 0000 0000 0000 0000 0000 0000 0000 ................ 0x01a0: 0000 0000 0000 0000 0000 0000 0000 0000 ................ 0x01b0: 0000 0000 0000 0000 0000 0000 0000 0000 ................ 0x01c0: 0000 0000 0000 0000 0000 0000 0000 0000 ................ 0x01d0: 0000 0000 0000 0000 0000 0000 0000 0000 ................ 0x01e0: 0000 0000 0000 0000 0000 0000 0000 0000 ................ 0x01f0: 0000 0000 0000 0000 0000 0000 0000 0000 ................ 0x0200: 0000 0000 0000 0000 0000 0000 0000 0000 ................ 0x0210: 0000 0000 0000 0000 0000 0000 0000 0000 ................ 0x0220: 0000 0000 0000 0000 0000 0000 0000 0000 ................ 0x0230: 0000 0000 0000 0000 0000 0000 0000 0000 ................ 22:28:36.929258 IP (tos 0x0, ttl 128, id 22737, 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 0x6247da8b, Flags [none] (0x0000) Your-IP 10.10.10.112 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 END Option 255, length 0 PAD Option 0, length 0, occurs 26 0x0000: 4500 0148 58d1 0000 8011 ccbb 0a0a 0a0f E..HX........... 0x0010: ffff ffff 0043 0044 0134 0e67 0201 0600 .....C.D.4.g.... 0x0020: 6247 da8b 0000 0000 0000 0000 0a0a 0a70 bG.............p 0x0030: 0a0a 0a18 0000 0000 0022 1956 9948 0000 .........".V.H.. 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 ........kbox2000 0x0090: 2e30 0000 0000 0000 0000 0000 0000 0000 .0.............. 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 ........c.Sc5... 0x0110: 04ff ffff 003a 0400 0038 403b 0400 0062 .....:...8@;...b 0x0120: 7033 0400 0070 8036 040a 0a0a 0fff 0000 p3...p.6........ 0x0130: 0000 0000 0000 0000 0000 0000 0000 0000 ................ 0x0140: 0000 0000 0000 0000 ........ ---------------------------------------------------------------------- Comment By: Holger Weiss (hweiss) Date: 2012-04-10 15:17 Message: Hmm. As I said, I agree that the plugin's interpretation of the "siaddr" field is wrong. However, from reading the code, I wouldn't have expected the behavior you're reporting unless the "server identifier" option isn't set. So, I'd like to understand what's going on. Could you attach the dump of a DHCP session initiated by check_dhcp? ---------------------------------------------------------------------- Comment By: Jason Ellison (infotek411) Date: 2012-04-10 14:59 Message: In the tcpdump you can see the Server-ID (option 54) was set to 10.10.10.15 Server-ID Option 54, length 4: 10.10.10.15 0x36 (54) lenght 04 0a(10) 0a(10) 0a(10) 0f(15) 0x0120: 7033 0400 0070 8036 040a 0a0a 0f It appears to me that there is confusion of "Server Identifier" and "Server IP" that only comes up when one is using an siaddr. http://www.ietf.org/rfc/rfc2131.txt DHCP clarifies the interpretation of the 'siaddr' field as the address of the server to use in the next step of the client's bootstrap process. A DHCP server may return its own address in the 'siaddr' field, if the server is prepared to supply the next bootstrap service (e.g., delivery of an operating system executable image). A DHCP server always returns its own address in the 'server identifier' option. siaddr 4 IP address of next server to use in bootstrap; returned in DHCPOFFER, DHCPACK by server. ---------------------------------------------------------------------- Comment By: Jason Ellison (infotek411) Date: 2012-04-10 13:47 Message: Server is a Windows 2003 DHCP server with next-server "siaddr" set for PXE boot. ---------------------------------------------------------------------- Comment By: Andy () Date: 2012-04-09 08:00 Message: I get the "wrong" response without the above change also. DHCP is Windows Server 2008 R1 (actually SBS). We have a PXE Boot server and the check_dhcp thinks the PXE Boot is the actual server, which fails. ---------------------------------------------------------------------- Comment By: Holger Weiss (hweiss) Date: 2012-03-14 10:31 Message: What sort of DHCP server are you running? The plugin will only use "siaddr" in this way if the mandatory "server identifier" option is missing from the server's response. It seems the current code tried to fix some problem which showed up in certain environments with DHCP relays involved. However, in principle I agree that the plugin's interpretation of the "siaddr" field isn't correct. ---------------------------------------------------------------------- Comment By: Jason Ellison (infotek411) Date: 2012-03-13 17:27 Message: diff --git a/a/plugins-root/check_dhcp.c b/b/plugins-root/check_dhcp.c index 2a1875c..b7f695b 100644 --- a/a/plugins-root/check_dhcp.c +++ b/b/plugins-root/check_dhcp.c @@ -588,10 +588,11 @@ int get_dhcp_offer(int sock){ memcpy(&via,&source,sizeof(source)) ; /* If siaddr is non-zero, set "source" to siaddr */ +/* don't set the source to next boot server (siaddr) 591 [email protected] if(offer_packet.siaddr.s_addr != 0L){ source.sin_addr.s_addr = offer_packet.siaddr.s_addr ; } - +*/ if(verbose){ printf(_("DHCPOFFER from IP address %s"),inet_ntoa(source.sin_addr)); printf(_(" via %s\n"),inet_ntoa(via.sin_addr)); ---------------------------------------------------------------------- Comment By: Jason Ellison (infotek411) Date: 2012-03-13 17:03 Message: I verified that I can check remote DHCP servers correctly after applying the fix. Options used were "check_dhcp -u -s 10.10.10.15". ---------------------------------------------------------------------- Comment By: [email protected] () Date: 2012-03-13 16:47 Message: Example of -s being specified correctly in verbose mode. Fails because siaddr (10.10.10.24) is copied over source (10.10.10.15). root@nagios:/usr/local/src/nagios-plugins-1.4.15# ./plugins-root/check_dhcp -v -s 10.10.10.15 Requested server address: 10.10.10.15 DHCP socket: 3 Hardware address: 00:22:19:56:99:48 DHCPDISCOVER to 255.255.255.255 port 67 DHCPDISCOVER XID: 513242689 (0x1E977641) 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 10.10.10.24 via 10.10.10.15 DHCPOFFER XID: 513242689 (0x1E977641) 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 @ 10.10.10.24 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 CRITICAL: Received 1 DHCPOFFER(s), 0 of 1 requested servers responded, max lease time = 0 sec. ---------------------------------------------------------------------- Comment By: [email protected] () Date: 2012-03-13 16:33 Message: The ticket contains the output of check_dhcp after I fixed it (oops). Sorry :( Jason Ellison Below is the output from an unmodified version of check_dhcp : root@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: 1292513780 (0x4D0A31F4) 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 10.10.10.24 via 10.10.10.15 DHCPOFFER XID: 1292513780 (0x4D0A31F4) 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 @ 10.10.10.24 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. ---------------------------------------------------------------------- Comment By: [email protected] () Date: 2012-03-13 16:22 Message: was trying to use google login... Jason Ellison [email protected] ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=397597&aid=3503921&group_id=29880 ------------------------------------------------------------------------------ Learn Graph Databases - Download FREE O'Reilly Book "Graph Databases" is the definitive new guide to graph databases and their applications. This 200-page book is written by three acclaimed leaders in the field. The early access version is available now. Download your free book today! http://p.sf.net/sfu/neotech_d2d_may _______________________________________________________ Nagios Plugin Development Mailing List [email protected] Unsubscribe at https://lists.sourceforge.net/lists/listinfo/nagiosplug-devel ::: Please include plugins version (-v) and OS when reporting any issue. ::: Messages without supporting info will risk being sent to /dev/null