path: root/web/attachments/366217-check_dhcp.patch

--- /home/thunderboltFS/mike/usr/local/src/nagios-plugins-1.4.14/plugins-root/check_dhcp.c.old	2010-03-05 11:26:26.000000000 -0600
+++ /home/thunderboltFS/mike/usr/local/src/nagios-plugins-1.4.14/plugins-root/check_dhcp.c	2010-03-10 17:36:02.313724052 -0600
@@ -291,6 +291,9 @@
 	/* wait for a DHCPOFFER packet */
 	get_dhcp_offer(dhcp_socket);
 
+	/* send DHCPREQUEST packet */
+	send_dhcp_request(dhcp_socket);
+
 	/* close socket we created */
 	close_dhcp_socket(dhcp_socket);
 
@@ -411,7 +414,7 @@
 		print_hardware_address(client_hardware_address);
 
 	return OK;
-        }
+	}
 
 /* determines IP address of the client interface */
 int get_ip_address(int sock,char *interface_name){
@@ -444,7 +447,7 @@
 int send_dhcp_discover(int sock){
 	dhcp_packet discover_packet;
 	struct sockaddr_in sockaddr_broadcast;
-    unsigned short opts;
+	unsigned short opts;
 
 
 	/* clear the packet data structure */
@@ -490,7 +493,7 @@
 	discover_packet.options[2]='\x53';
 	discover_packet.options[3]='\x63';
 
-    opts = 4;
+	opts = 4;
 	/* DHCP message type is embedded in options field */
 	discover_packet.options[opts++]=DHCP_OPTION_MESSAGE_TYPE;    /* DHCP message type option identifier */
 	discover_packet.options[opts++]='\x01';               /* DHCP message option length in bytes */
@@ -502,7 +505,7 @@
 		discover_packet.options[opts++]='\x04';
 		memcpy(&discover_packet.options[opts],&requested_address,sizeof(requested_address));
 		opts += sizeof(requested_address);
-	        }
+		}
 	discover_packet.options[opts++]=DHCP_OPTION_END;
 
 	/* unicast fields */
@@ -513,8 +516,8 @@
 	discover_packet.hops = unicast ? 1 : 0;
 
 	/* send the DHCPDISCOVER packet to broadcast address */
-        sockaddr_broadcast.sin_family=AF_INET;
-        sockaddr_broadcast.sin_port=htons(DHCP_SERVER_PORT);
+	sockaddr_broadcast.sin_family=AF_INET;
+	sockaddr_broadcast.sin_port=htons(DHCP_SERVER_PORT);
 	sockaddr_broadcast.sin_addr.s_addr = unicast ? dhcp_ip.s_addr : INADDR_BROADCAST;
 	bzero(&sockaddr_broadcast.sin_zero,sizeof(sockaddr_broadcast.sin_zero));
 
@@ -522,10 +525,10 @@
 	if(verbose){
 		printf(_("DHCPDISCOVER to %s port %d\n"),inet_ntoa(sockaddr_broadcast.sin_addr),ntohs(sockaddr_broadcast.sin_port));
 		printf("DHCPDISCOVER XID: %u (0x%X)\n",ntohl(discover_packet.xid),ntohl(discover_packet.xid));
-		printf("DHCDISCOVER ciaddr:  %s\n",inet_ntoa(discover_packet.ciaddr));
-		printf("DHCDISCOVER yiaddr:  %s\n",inet_ntoa(discover_packet.yiaddr));
-		printf("DHCDISCOVER siaddr:  %s\n",inet_ntoa(discover_packet.siaddr));
-		printf("DHCDISCOVER giaddr:  %s\n",inet_ntoa(discover_packet.giaddr));
+		printf("DHCPDISCOVER ciaddr:  %s\n",inet_ntoa(discover_packet.ciaddr));
+		printf("DHCPDISCOVER yiaddr:  %s\n",inet_ntoa(discover_packet.yiaddr));
+		printf("DHCPDISCOVER siaddr:  %s\n",inet_ntoa(discover_packet.siaddr));
+		printf("DHCPDISCOVER giaddr:  %s\n",inet_ntoa(discover_packet.giaddr));
 		}
 
 	/* send the DHCPDISCOVER packet out */
@@ -535,9 +538,110 @@
 		printf("\n\n");
 
 	return OK;
-        }
+	}
+
+/* sends a DHCPREQUEST broadcast message in an attempt to allow DHCP servers to drop any OFFER reservations and return those IPs to their free pools */
+int send_dhcp_request(int sock){
+	dhcp_packet discover_packet;
+	struct sockaddr_in sockaddr_broadcast;
+	unsigned short opts;
+
+
+	/* clear the packet data structure */
+	bzero(&discover_packet,sizeof(discover_packet));
+
+
+	/* boot request flag (backward compatible with BOOTP servers) */
+	discover_packet.op=BOOTREQUEST;
+
+	/* hardware address type */
+	discover_packet.htype=ETHERNET_HARDWARE_ADDRESS;
+
+	/* length of our hardware address */
+	discover_packet.hlen=ETHERNET_HARDWARE_ADDRESS_LENGTH;
+
+	/*
+	 * transaction ID is supposed to be random.  We won't use the address so
+	 * we don't care about high entropy here.  time(2) is good enough.
+	 */
+	srand(time(NULL));
+	packet_xid=random();
+	discover_packet.xid=htonl(packet_xid);
+
+	/**** WHAT THE HECK IS UP WITH THIS?!?  IF I DON'T MAKE THIS CALL, ONLY ONE SERVER RESPONSE IS PROCESSED!!!! ****/
+	/* downright bizzarre... */
+	ntohl(discover_packet.xid);
+
+	/*discover_packet.secs=htons(65535);*/
+	discover_packet.secs=0xFF;
+
+	/*
+	 * server needs to know if it should broadcast or unicast its response:
+	 * 0x8000L == 32768 == 1 << 15 == broadcast, 0 == unicast
+	 */
+	discover_packet.flags = unicast ? 0 : htons(DHCP_BROADCAST_FLAG);
+
+	/* our hardware address */
+	memcpy(discover_packet.chaddr,client_hardware_address,ETHERNET_HARDWARE_ADDRESS_LENGTH);
+
+	/* first four bytes of options field is magic cookie (as per RFC 2132) */
+	discover_packet.options[0]='\x63';
+	discover_packet.options[1]='\x82';
+	discover_packet.options[2]='\x53';
+	discover_packet.options[3]='\x63';
+
+	opts = 4;
+	/* DHCP message type is embedded in options field */
+	discover_packet.options[opts++]=DHCP_OPTION_MESSAGE_TYPE;    /* DHCP message type option identifier */
+	discover_packet.options[opts++]='\x01';               /* DHCP message option length in bytes */
+	discover_packet.options[opts++]=DHCPREQUEST;
+
+	/* the IP address we're requesting */
+	if(request_specific_address==TRUE){
+		discover_packet.options[opts++]=DHCP_OPTION_REQUESTED_ADDRESS;
+		discover_packet.options[opts++]='\x04';
+		memcpy(&discover_packet.options[opts],&requested_address,sizeof(requested_address));
+		opts += sizeof(requested_address);
+	        }
+
+	/* Set the server identifier to our own address, so that no other DHCP server will match */
+	discover_packet.options[opts++]=DHCP_OPTION_SERVER_IDENTIFIER;
+	discover_packet.options[opts++]='\x04';
+	memcpy(&discover_packet.options[opts],&discover_packet.ciaddr,sizeof(discover_packet.ciaddr));
+
+	discover_packet.options[opts++]=DHCP_OPTION_END;
+
+	/* unicast fields */
+	if(unicast)
+		discover_packet.giaddr.s_addr = my_ip.s_addr;
+
+	/* see RFC 1542, 4.1.1 */
+	discover_packet.hops = unicast ? 1 : 0;
+
+	/* send the DHCPREQUEST packet to broadcast address */
+	sockaddr_broadcast.sin_family=AF_INET;
+	sockaddr_broadcast.sin_port=htons(DHCP_SERVER_PORT);
+	sockaddr_broadcast.sin_addr.s_addr = unicast ? dhcp_ip.s_addr : INADDR_BROADCAST;
+	bzero(&sockaddr_broadcast.sin_zero,sizeof(sockaddr_broadcast.sin_zero));
+
 
+	if(verbose){
+		printf(_("DHCPREQUEST to %s port %d\n"),inet_ntoa(sockaddr_broadcast.sin_addr),ntohs(sockaddr_broadcast.sin_port));
+		printf("DHCPREQUEST XID: %u (0x%X)\n",ntohl(discover_packet.xid),ntohl(discover_packet.xid));
+		printf("DHCPREQUEST ciaddr:  %s\n",inet_ntoa(discover_packet.ciaddr));
+		printf("DHCPREQUEST yiaddr:  %s\n",inet_ntoa(discover_packet.yiaddr));
+		printf("DHCPREQUEST siaddr:  %s\n",inet_ntoa(discover_packet.siaddr));
+		printf("DHCPREQUEST giaddr:  %s\n",inet_ntoa(discover_packet.giaddr));
+		}
 
+	/* send the DHCPREQUEST packet out */
+	send_dhcp_packet(&discover_packet,sizeof(discover_packet),sock,&sockaddr_broadcast);
+
+	if(verbose)
+		printf("\n\n");
+
+	return OK;
+	}
 
 
 /* waits for a DHCPOFFER message from one or more DHCP servers */
@@ -604,7 +708,7 @@
 				printf(_("DHCPOFFER XID (%u) did not match DHCPDISCOVER XID (%u) - ignoring packet\n"),ntohl(offer_packet.xid),packet_xid);
 
 			continue;
-		        }
+			}
 
 		/* check hardware address */
 		result=OK;
@@ -626,7 +730,7 @@
 				printf(_("DHCPOFFER hardware address did not match our own - ignoring packet\n"));
 
 			continue;
-		        }
+			}
 
 		if(verbose){
 			printf("DHCPOFFER ciaddr: %s\n",inet_ntoa(offer_packet.ciaddr));
@@ -638,7 +742,7 @@
 		add_dhcp_offer(source.sin_addr,&offer_packet);
 
 		valid_responses++;
-	        }
+		}
 
 	if(verbose){
 		printf(_("Total responses seen on the wire: %d\n"),responses);
@@ -646,7 +750,7 @@
 		}
 
 	return OK;
-        }
+	}
 
 
 
@@ -663,7 +767,7 @@
 		return ERROR;
 
 	return OK;
-        }
+	}
 
 
 
@@ -713,7 +817,7 @@
 				printf("errno: (%d) -> %s\n",errno,strerror(errno));
 				}
                         return ERROR;
-                        }
+			}
 		else{
 			if(verbose){
 				printf(_("receive_dhcp_packet() result: %d\n"),recv_result);
@@ -722,11 +826,11 @@
 
 			memcpy(address,&source_address,sizeof(source_address));
 			return OK;
-		        }
-                }
+			}
+		}
 
 	return OK;
-        }
+	}
 
 
 /* creates a socket for DHCP communication */
@@ -749,7 +853,7 @@
         if(sock<0){
 		printf(_("Error: Could not create socket!\n"));
 		exit(STATE_UNKNOWN);
-	        }
+		}
 
 	if(verbose)
 		printf("DHCP socket: %d\n",sock);
@@ -759,13 +863,13 @@
         if(setsockopt(sock,SOL_SOCKET,SO_REUSEADDR,(char *)&flag,sizeof(flag))<0){
 		printf(_("Error: Could not set reuse address option on DHCP socket!\n"));
 		exit(STATE_UNKNOWN);
-	        }
+		}
 
         /* set the broadcast option - we need this to listen to DHCP broadcast messages */
         if(!unicast && setsockopt(sock,SOL_SOCKET,SO_BROADCAST,(char *)&flag,sizeof flag)<0){
 		printf(_("Error: Could not set broadcast option on DHCP socket!\n"));
 		exit(STATE_UNKNOWN);
-	        }
+		}
 
 	/* bind socket to interface */
 #if defined(__linux__)
@@ -774,7 +878,7 @@
 	if(setsockopt(sock,SOL_SOCKET,SO_BINDTODEVICE,(char *)&interface,sizeof(interface))<0){
 		printf(_("Error: Could not bind socket to interface %s.  Check your privileges...\n"),network_interface_name);
 		exit(STATE_UNKNOWN);
-	        }
+		}
 
 #else
 	strncpy(interface.ifr_name,network_interface_name,IFNAMSIZ-1);
@@ -785,10 +889,10 @@
         if(bind(sock,(struct sockaddr *)&myname,sizeof(myname))<0){
 		printf(_("Error: Could not bind to DHCP socket (port %d)!  Check your privileges...\n"),DHCP_CLIENT_PORT);
 		exit(STATE_UNKNOWN);
-	        }
+		}
 
         return sock;
-        }
+	}
 
 
 /* closes DHCP socket */
@@ -820,7 +924,7 @@
 		printf(_("Requested server address: %s\n"),inet_ntoa(new_server->server_address));
 
 	return OK;
-        }
+	}
 
 
 
@@ -924,7 +1028,7 @@
 	dhcp_offer_list=new_offer;
 
 	return OK;
-        }
+	}
 
 
 /* frees memory allocated to DHCP OFFER list */
@@ -938,7 +1042,7 @@
 	        }
 
 	return OK;
-        }
+	}
 
 
 /* frees memory allocated to requested server list */
@@ -949,10 +1053,10 @@
 	for(this_server=requested_server_list;this_server!=NULL;this_server=next_server){
 		next_server=this_server->next;
 		free(this_server);
-	        }
+		}
 
 	return OK;
-        }
+	}
 
 
 /* gets state and plugin output to return */
@@ -993,11 +1097,11 @@
 						requested_responses++;
 						temp_server->answered=TRUE;
 						}
-				        }
-		                }
-		        }
+					}
+				}
+			}
 
-	        }
+		}
 
 	/* else check and see if we got our requested address from any server */
 	else{
@@ -1011,8 +1115,8 @@
 			/* see if we got the address we requested */
 			if(!memcmp(&requested_address,&temp_offer->offered_address,sizeof(requested_address)))
 				received_requested_address=TRUE;
-	                }
-	        }
+			}
+		}
 
 	result=STATE_OK;
 	if(valid_responses==0)
@@ -1037,7 +1141,7 @@
 	if(dhcp_offer_list==NULL){
 		printf(_("No DHCPOFFERs were received.\n"));
 		return result;
-	        }
+		}
 
 	printf(_("Received %d DHCPOFFER(s)"),valid_responses);
 
@@ -1056,7 +1160,7 @@
 	printf(".\n");
 
 	return result;
-        }
+	}
 
 
 /* process command-line arguments */
@@ -1076,7 +1180,7 @@
 		}
 
 	return validate_arguments();
-        }
+	}
 
 
 
@@ -1181,17 +1285,17 @@
 
 		default:
 			break;
-		        }
-	        }
+			}
+		}
 
 	return i;
-        }
+	}
 
 
 int validate_arguments(void){
 
 	return OK;
-        }
+	}
 
 
 #if defined(__sun__) || defined(__solaris__) || defined(__hpux__)