/****************************************************************************** * * Nagios check_dhcp plugin * * License: GPL * Copyright (c) 2001-2004 Ethan Galstad (nagios@nagios.org) * Copyright (c) 2001-2006 Nagios Plugin Development Team * * Last Modified: $Date: 2007-07-26 18:32:37 +0100 (Thu, 26 Jul 2007) $ * * Description: * * This file contains the check_dhcp plugin * * This plugin tests the availability of DHCP servers on a network. * * * License Information: * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. * * $Id: check_dhcp.c 1766 2007-07-26 17:32:37Z hweiss $ * * ------------------------------------------------------------------------ * Unicast mode was originally implemented by Heiti of Boras Kommun with * general improvements as well as usability fixes and "forward"-porting by * Andreas Ericsson of OP5 AB. * ------------------------------------------------------------------------ * *****************************************************************************/ const char *progname = "check_dhcp"; const char *revision = "$Revision: 1766 $"; const char *copyright = "2001-2006"; const char *email = "nagiosplug-devel@lists.sourceforge.net"; #include "common.h" #include "netutils.h" #include "utils.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #if HAVE_SYS_SOCKIO_H #include #endif #if defined( __linux__ ) #include #include #elif defined (__bsd__) #include #include #include #include #elif defined(__sun__) || defined(__solaris__) || defined(__hpux__) #define INSAP 22 #define OUTSAP 24 #include #include #include #include #include #define bcopy(source, destination, length) memcpy(destination, source, length) #define AREA_SZ 5000 /* buffer length in bytes */ static u_long ctl_area[AREA_SZ]; static u_long dat_area[AREA_SZ]; static struct strbuf ctl = {AREA_SZ, 0, (char *)ctl_area}; static struct strbuf dat = {AREA_SZ, 0, (char *)dat_area}; #define GOT_CTRL 1 #define GOT_DATA 2 #define GOT_BOTH 3 #define GOT_INTR 4 #define GOT_ERR 128 #define u_int8_t uint8_t #define u_int16_t uint16_t #define u_int32_t uint32_t static int get_msg(int); static int check_ctrl(int); static int put_ctrl(int, int, int); static int put_both(int, int, int, int); static int dl_open(const char *, int, int *); static int dl_bind(int, int, u_char *); long mac_addr_dlpi( const char *, int, u_char *); #endif /**** Common definitions ****/ #define OK 0 #define ERROR -1 #define FALSE 0 #define TRUE 1 /**** DHCP definitions ****/ #define MAX_DHCP_CHADDR_LENGTH 16 #define MAX_DHCP_SNAME_LENGTH 64 #define MAX_DHCP_FILE_LENGTH 128 #define MAX_DHCP_OPTIONS_LENGTH 312 typedef struct dhcp_packet_struct{ u_int8_t op; /* packet type */ u_int8_t htype; /* type of hardware address for this machine (Ethernet, etc) */ u_int8_t hlen; /* length of hardware address (of this machine) */ u_int8_t hops; /* hops */ u_int32_t xid; /* random transaction id number - chosen by this machine */ u_int16_t secs; /* seconds used in timing */ 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 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 */ char file [MAX_DHCP_FILE_LENGTH]; /* boot file name (used for diskless booting?) */ char options[MAX_DHCP_OPTIONS_LENGTH]; /* options */ }dhcp_packet; typedef struct dhcp_offer_struct{ struct in_addr server_address; /* address of DHCP server that sent this offer */ struct in_addr offered_address; /* the IP address that was offered to us */ u_int32_t lease_time; /* lease time in seconds */ u_int32_t renewal_time; /* renewal time in seconds */ u_int32_t rebinding_time; /* rebinding time in seconds */ struct dhcp_offer_struct *next; }dhcp_offer; typedef struct requested_server_struct{ struct in_addr server_address; int answered; struct requested_server_struct *next; }requested_server; #define BOOTREQUEST 1 #define BOOTREPLY 2 #define DHCPDISCOVER 1 #define DHCPOFFER 2 #define DHCPREQUEST 3 #define DHCPDECLINE 4 #define DHCPACK 5 #define DHCPNACK 6 #define DHCPRELEASE 7 #define DHCP_OPTION_MESSAGE_TYPE 53 #define DHCP_OPTION_HOST_NAME 12 #define DHCP_OPTION_BROADCAST_ADDRESS 28 #define DHCP_OPTION_REQUESTED_ADDRESS 50 #define DHCP_OPTION_LEASE_TIME 51 #define DHCP_OPTION_SERVER_IDENTIFIER 54 #define DHCP_OPTION_RENEWAL_TIME 58 #define DHCP_OPTION_REBINDING_TIME 59 #define DHCP_OPTION_END 255 #define DHCP_INFINITE_TIME 0xFFFFFFFF #define DHCP_BROADCAST_FLAG 32768 #define DHCP_UNICAST_FLAG 0 #define DHCP_SERVER_PORT 67 #define DHCP_CLIENT_PORT 68 #define ETHERNET_HARDWARE_ADDRESS 1 /* used in htype field of dhcp packet */ #define ETHERNET_HARDWARE_ADDRESS_LENGTH 6 /* length of Ethernet hardware addresses */ u_int8_t unicast = 0; /* unicast mode: mimic a DHCP relay */ struct in_addr my_ip; /* our address (required for relay) */ struct in_addr dhcp_ip; /* server to query (if in unicast mode) */ unsigned char client_hardware_address[MAX_DHCP_CHADDR_LENGTH]=""; unsigned char *user_specified_mac=NULL; char network_interface_name[IFNAMSIZ]="eth0"; u_int32_t packet_xid=0; u_int32_t dhcp_lease_time=0; u_int32_t dhcp_renewal_time=0; u_int32_t dhcp_rebinding_time=0; int dhcpoffer_timeout=2; dhcp_offer *dhcp_offer_list=NULL; requested_server *requested_server_list=NULL; int valid_responses=0; /* number of valid DHCPOFFERs we received */ int requested_servers=0; int requested_responses=0; int request_specific_address=FALSE; int received_requested_address=FALSE; int verbose=0; struct in_addr requested_address; int process_arguments(int, char **); int call_getopt(int, char **); int validate_arguments(void); void print_usage(void); void print_help(void); void resolve_host(const char *in,struct in_addr *out); unsigned char *mac_aton(const char *); void print_hardware_address(const unsigned char *); int get_hardware_address(int,char *); int get_ip_address(int,char *); int send_dhcp_discover(int); int get_dhcp_offer(int); int get_results(void); int add_dhcp_offer(struct in_addr,dhcp_packet *); int free_dhcp_offer_list(void); int free_requested_server_list(void); int create_dhcp_socket(void); int close_dhcp_socket(int); int send_dhcp_packet(void *,int,int,struct sockaddr_in *); int receive_dhcp_packet(void *,int,int,int,struct sockaddr_in *); int main(int argc, char **argv){ int dhcp_socket; int result = STATE_UNKNOWN; /* this plugin almost certainly needs root permissions. */ np_warn_if_not_root(); setlocale (LC_ALL, ""); bindtextdomain (PACKAGE, LOCALEDIR); textdomain (PACKAGE); if(process_arguments(argc,argv)!=OK){ usage4 (_("Could not parse arguments")); } /* create socket for DHCP communications */ dhcp_socket=create_dhcp_socket(); /* get hardware address of client machine */ if(user_specified_mac!=NULL) memcpy(client_hardware_address,user_specified_mac,6); else get_hardware_address(dhcp_socket,network_interface_name); if(unicast) /* get IP address of client machine */ get_ip_address(dhcp_socket,network_interface_name); /* send DHCPDISCOVER packet */ send_dhcp_discover(dhcp_socket); /* wait for a DHCPOFFER packet */ get_dhcp_offer(dhcp_socket); /* close socket we created */ close_dhcp_socket(dhcp_socket); /* determine state/plugin output to return */ result=get_results(); /* free allocated memory */ free_dhcp_offer_list(); free_requested_server_list(); return result; } /* determines hardware address on client machine */ int get_hardware_address(int sock,char *interface_name){ #if defined(__linux__) struct ifreq ifr; strncpy((char *)&ifr.ifr_name,interface_name,sizeof(ifr.ifr_name)-1); ifr.ifr_name[sizeof(ifr.ifr_name)-1]='\0'; /* try and grab hardware address of requested interface */ if(ioctl(sock,SIOCGIFHWADDR,&ifr)<0){ printf(_("Error: Could not get hardware address of interface '%s'\n"),interface_name); exit(STATE_UNKNOWN); } memcpy(&client_hardware_address[0],&ifr.ifr_hwaddr.sa_data,6); #elif defined(__bsd__) /* King 2004 see ACKNOWLEDGEMENTS */ int mib[6], len; char *buf; unsigned char *ptr; struct if_msghdr *ifm; struct sockaddr_dl *sdl; mib[0] = CTL_NET; mib[1] = AF_ROUTE; mib[2] = 0; mib[3] = AF_LINK; mib[4] = NET_RT_IFLIST; if((mib[5] = if_nametoindex(interface_name)) == 0){ printf(_("Error: if_nametoindex error - %s.\n"), strerror(errno)); exit(STATE_UNKNOWN); } if(sysctl(mib, 6, NULL, &len, NULL, 0) < 0){ printf(_("Error: Couldn't get hardware address from %s. sysctl 1 error - %s.\n"), interface_name, strerror(errno)); exit(STATE_UNKNOWN); } if((buf = malloc(len)) == NULL){ printf(_("Error: Couldn't get hardware address from interface %s. malloc error - %s.\n"), interface_name, strerror(errno)); exit(4); } if(sysctl(mib, 6, buf, &len, NULL, 0) < 0){ printf(_("Error: Couldn't get hardware address from %s. sysctl 2 error - %s.\n"), interface_name, strerror(errno)); exit(STATE_UNKNOWN); } ifm = (struct if_msghdr *)buf; sdl = (struct sockaddr_dl *)(ifm + 1); ptr = (unsigned char *)LLADDR(sdl); memcpy(&client_hardware_address[0], ptr, 6) ; /* King 2004 */ #elif defined(__sun__) || defined(__solaris__) /* Kompf 2000-2003 see ACKNOWLEDGEMENTS */ long stat; char dev[20] = "/dev/"; char *p; int unit; for(p = interface_name; *p && isalpha(*p); p++) /* no-op */ ; if( p != '\0' ){ unit = atoi(p) ; *p = '\0' ; strncat(dev, interface_name, 6) ; } else{ printf(_("Error: can't find unit number in interface_name (%s) - expecting TypeNumber eg lnc0.\n"), interface_name); exit(STATE_UNKNOWN); } stat = mac_addr_dlpi(dev, unit, client_hardware_address); if(stat != 0){ printf(_("Error: can't read MAC address from DLPI streams interface for device %s unit %d.\n"), dev, unit); exit(STATE_UNKNOWN); } #elif defined(__hpux__) long stat; char dev[20] = "/dev/dlpi" ; int unit = 0; stat = mac_addr_dlpi(dev, unit, client_hardware_address); if(stat != 0){ printf(_("Error: can't read MAC address from DLPI streams interface for device %s unit %d.\n"), dev, unit); exit(STATE_UNKNOWN); } /* Kompf 2000-2003 */ #else printf(_("Error: can't get MAC address for this architecture. Use the --mac option.\n")); exit(STATE_UNKNOWN); #endif if(verbose) print_hardware_address(client_hardware_address); return OK; } /* determines IP address of the client interface */ int get_ip_address(int sock,char *interface_name){ #if defined(SIOCGIFADDR) struct ifreq ifr; strncpy((char *)&ifr.ifr_name,interface_name,sizeof(ifr.ifr_name)-1); ifr.ifr_name[sizeof(ifr.ifr_name)-1]='\0'; if(ioctl(sock,SIOCGIFADDR,&ifr)<0){ printf(_("Error: Cannot determine IP address of interface %s\n"), interface_name); exit(STATE_UNKNOWN); } my_ip=((struct sockaddr_in *)&ifr.ifr_addr)->sin_addr; #else printf(_("Error: Cannot get interface IP address on this platform.\n")); exit(STATE_UNKNOWN); #endif if(verbose) printf(_("Pretending to be relay client %s\n"),inet_ntoa(my_ip)); return OK; } /* sends a DHCPDISCOVER broadcast message in an attempt to find DHCP servers */ int send_dhcp_discover(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++]=DHCPDISCOVER; /* 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); } 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 DHCPDISCOVER 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(_("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)); } /* send the DHCPDISCOVER 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 */ int get_dhcp_offer(int sock){ dhcp_packet offer_packet; struct sockaddr_in source; struct sockaddr_in via; int result=OK; int responses=0; int x; time_t start_time; time_t current_time; time(&start_time); /* receive as many responses as we can */ for(responses=0,valid_responses=0;;){ time(¤t_time); if((current_time-start_time)>=dhcpoffer_timeout) break; if(verbose) printf("\n\n"); bzero(&source,sizeof(source)); bzero(&via,sizeof(via)); bzero(&offer_packet,sizeof(offer_packet)); result=OK; result=receive_dhcp_packet(&offer_packet,sizeof(offer_packet),sock,dhcpoffer_timeout,&source); if(result!=OK){ if(verbose) printf(_("Result=ERROR\n")); continue; } else{ if(verbose) printf(_("Result=OK\n")); responses++; } /* The "source" is either a server or a relay. */ /* 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)); printf("DHCPOFFER XID: %u (0x%X)\n",ntohl(offer_packet.xid),ntohl(offer_packet.xid)); } /* check packet xid to see if its the same as the one we used in the discover packet */ if(ntohl(offer_packet.xid)!=packet_xid){ if(verbose) 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; if(verbose) printf("DHCPOFFER chaddr: "); for(x=0;x %s\n",errno,strerror(errno)); } return ERROR; } else{ if(verbose){ printf(_("receive_dhcp_packet() result: %d\n"),recv_result); printf(_("receive_dhcp_packet() source: %s\n"),inet_ntoa(source_address.sin_addr)); } memcpy(address,&source_address,sizeof(source_address)); return OK; } } return OK; } /* creates a socket for DHCP communication */ int create_dhcp_socket(void){ struct sockaddr_in myname; struct ifreq interface; int sock; int flag=1; /* Set up the address we're going to bind to. */ bzero(&myname,sizeof(myname)); myname.sin_family=AF_INET; /* listen to DHCP server port if we're in unicast mode */ myname.sin_port = htons(unicast ? DHCP_SERVER_PORT : DHCP_CLIENT_PORT); myname.sin_addr.s_addr = unicast ? my_ip.s_addr : INADDR_ANY; bzero(&myname.sin_zero,sizeof(myname.sin_zero)); /* create a socket for DHCP communications */ sock=socket(AF_INET,SOCK_DGRAM,IPPROTO_UDP); if(sock<0){ printf(_("Error: Could not create socket!\n")); exit(STATE_UNKNOWN); } if(verbose) printf("DHCP socket: %d\n",sock); /* set the reuse address flag so we don't get errors when restarting */ flag=1; 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(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__) strncpy(interface.ifr_ifrn.ifrn_name,network_interface_name,IFNAMSIZ-1); interface.ifr_ifrn.ifrn_name[IFNAMSIZ-1]='\0'; 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); interface.ifr_name[IFNAMSIZ-1]='\0'; #endif /* bind the socket */ 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 */ int close_dhcp_socket(int sock){ close(sock); return OK; } /* adds a requested server address to list in memory */ int add_requested_server(struct in_addr server_address){ requested_server *new_server; new_server=(requested_server *)malloc(sizeof(requested_server)); if(new_server==NULL) return ERROR; new_server->server_address=server_address; new_server->answered=FALSE; new_server->next=requested_server_list; requested_server_list=new_server; requested_servers++; if(verbose) printf(_("Requested server address: %s\n"),inet_ntoa(new_server->server_address)); return OK; } /* adds a DHCP OFFER to list in memory */ int add_dhcp_offer(struct in_addr source,dhcp_packet *offer_packet){ dhcp_offer *new_offer; int x; unsigned option_type; unsigned option_length; struct in_addr serv_ident = {0}; if(offer_packet==NULL) return ERROR; /* process all DHCP options present in the packet */ for(x=4;xoptions[x]==-1 || (int)offer_packet->options[x]==0) break; /* get option type */ option_type=offer_packet->options[x++]; /* get option length */ option_length=offer_packet->options[x++]; if(verbose) printf("Option: %d (0x%02X)\n",option_type,option_length); /* get option data */ switch(option_type){ case DHCP_OPTION_LEASE_TIME: memcpy(&dhcp_lease_time, &offer_packet->options[x],sizeof(dhcp_lease_time)); dhcp_lease_time = ntohl(dhcp_lease_time); break; case DHCP_OPTION_RENEWAL_TIME: memcpy(&dhcp_renewal_time, &offer_packet->options[x],sizeof(dhcp_renewal_time)); dhcp_renewal_time = ntohl(dhcp_renewal_time); break; case DHCP_OPTION_REBINDING_TIME: memcpy(&dhcp_rebinding_time, &offer_packet->options[x],sizeof(dhcp_rebinding_time)); dhcp_rebinding_time = ntohl(dhcp_rebinding_time); break; case DHCP_OPTION_SERVER_IDENTIFIER: 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; } if(verbose){ if(dhcp_lease_time==DHCP_INFINITE_TIME) printf(_("Lease Time: Infinite\n")); else printf(_("Lease Time: %lu seconds\n"),(unsigned long)dhcp_lease_time); if(dhcp_renewal_time==DHCP_INFINITE_TIME) printf(_("Renewal Time: Infinite\n")); else printf(_("Renewal Time: %lu seconds\n"),(unsigned long)dhcp_renewal_time); if(dhcp_rebinding_time==DHCP_INFINITE_TIME) printf(_("Rebinding Time: Infinite\n")); printf(_("Rebinding Time: %lu seconds\n"),(unsigned long)dhcp_rebinding_time); } new_offer=(dhcp_offer *)malloc(sizeof(dhcp_offer)); if(new_offer==NULL) return ERROR; /* * RFC 2131 (2.) says: "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." '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'. */ new_offer->server_address=serv_ident.s_addr?serv_ident:source; new_offer->offered_address=offer_packet->yiaddr; new_offer->lease_time=dhcp_lease_time; new_offer->renewal_time=dhcp_renewal_time; new_offer->rebinding_time=dhcp_rebinding_time; if(verbose){ printf(_("Added offer from server @ %s"),inet_ntoa(new_offer->server_address)); printf(_(" of IP address %s\n"),inet_ntoa(new_offer->offered_address)); } /* add new offer to head of list */ new_offer->next=dhcp_offer_list; dhcp_offer_list=new_offer; return OK; } /* frees memory allocated to DHCP OFFER list */ int free_dhcp_offer_list(void){ dhcp_offer *this_offer; dhcp_offer *next_offer; for(this_offer=dhcp_offer_list;this_offer!=NULL;this_offer=next_offer){ next_offer=this_offer->next; free(this_offer); } return OK; } /* frees memory allocated to requested server list */ int free_requested_server_list(void){ requested_server *this_server; requested_server *next_server; 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 */ int get_results(void){ dhcp_offer *temp_offer; requested_server *temp_server; int result; u_int32_t max_lease_time=0; received_requested_address=FALSE; /* checks responses from requested servers */ requested_responses=0; if(requested_servers>0){ for(temp_server=requested_server_list;temp_server!=NULL;temp_server=temp_server->next){ for(temp_offer=dhcp_offer_list;temp_offer!=NULL;temp_offer=temp_offer->next){ /* get max lease time we were offered */ if(temp_offer->lease_time>max_lease_time || temp_offer->lease_time==DHCP_INFINITE_TIME) max_lease_time=temp_offer->lease_time; /* see if we got the address we requested */ if(!memcmp(&requested_address,&temp_offer->offered_address,sizeof(requested_address))) received_requested_address=TRUE; /* see if the servers we wanted a response from talked to us or not */ if(!memcmp(&temp_offer->server_address,&temp_server->server_address,sizeof(temp_server->server_address))){ if(verbose){ printf(_("DHCP Server Match: Offerer=%s"),inet_ntoa(temp_offer->server_address)); printf(_(" Requested=%s"),inet_ntoa(temp_server->server_address)); if(temp_server->answered) printf(_(" (duplicate)")); printf(_("\n")); } if(temp_server->answered == FALSE){ requested_responses++; temp_server->answered=TRUE; } } } } } /* else check and see if we got our requested address from any server */ else{ for(temp_offer=dhcp_offer_list;temp_offer!=NULL;temp_offer=temp_offer->next){ /* get max lease time we were offered */ if(temp_offer->lease_time>max_lease_time || temp_offer->lease_time==DHCP_INFINITE_TIME) max_lease_time=temp_offer->lease_time; /* 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) result=STATE_CRITICAL; else if(requested_servers>0 && requested_responses==0) result=STATE_CRITICAL; else if(requested_responses0) printf(_(", %s%d of %d requested servers responded"),((requested_responses0)?"only ":"",requested_responses,requested_servers); if(request_specific_address==TRUE) printf(_(", requested address (%s) was %soffered"),inet_ntoa(requested_address),(received_requested_address==TRUE)?"":_("not ")); printf(_(", max lease time = ")); if(max_lease_time==DHCP_INFINITE_TIME) printf(_("Infinity")); else printf("%lu sec",(unsigned long)max_lease_time); printf(".\n"); return result; } /* process command-line arguments */ int process_arguments(int argc, char **argv){ int c; if(argc<1) return ERROR; c=0; while((c+=(call_getopt(argc-c,&argv[c])))0) dhcpoffer_timeout=atoi(optarg); /* else usage("Time interval must be a nonnegative integer\n"); */ break; case 'm': /* MAC address */ if((user_specified_mac=mac_aton(optarg)) == NULL) usage("Cannot parse MAC address.\n"); if(verbose) print_hardware_address(user_specified_mac); break; case 'i': /* interface name */ strncpy(network_interface_name,optarg,sizeof(network_interface_name)-1); network_interface_name[sizeof(network_interface_name)-1]='\x0'; break; case 'u': /* unicast testing */ unicast=1; break; case 'V': /* version */ print_revision(progname,revision); exit(STATE_OK); case 'h': /* help */ print_help(); exit(STATE_OK); case 'v': /* verbose */ verbose=1; break; case '?': /* help */ usage5 (); break; default: break; } } return i; } int validate_arguments(void){ return OK; } #if defined(__sun__) || defined(__solaris__) || defined(__hpux__) /* Kompf 2000-2003 see ACKNOWLEDGEMENTS */ /* get a message from a stream; return type of message */ static int get_msg(int fd){ int flags = 0; int res, ret; ctl_area[0] = 0; dat_area[0] = 0; ret = 0; res = getmsg(fd, &ctl, &dat, &flags); if(res < 0){ if(errno == EINTR){ return(GOT_INTR); } else{ printf("%s\n", "get_msg FAILED."); return(GOT_ERR); } } if(ctl.len > 0){ ret |= GOT_CTRL; } if(dat.len > 0){ ret |= GOT_DATA; } return(ret); } /* verify that dl_primitive in ctl_area = prim */ static int check_ctrl(int prim){ dl_error_ack_t *err_ack = (dl_error_ack_t *)ctl_area; if(err_ack->dl_primitive != prim){ printf(_("Error: DLPI stream API failed to get MAC in check_ctrl: %s.\n"), strerror(errno)); exit(STATE_UNKNOWN); } return 0; } /* put a control message on a stream */ static int put_ctrl(int fd, int len, int pri){ ctl.len = len; if(putmsg(fd, &ctl, 0, pri) < 0){ printf(_("Error: DLPI stream API failed to get MAC in put_ctrl/putmsg(): %s.\n"), strerror(errno)); exit(STATE_UNKNOWN); } return 0; } /* put a control + data message on a stream */ static int put_both(int fd, int clen, int dlen, int pri){ ctl.len = clen; dat.len = dlen; if(putmsg(fd, &ctl, &dat, pri) < 0){ printf(_("Error: DLPI stream API failed to get MAC in put_both/putmsg().\n"), strerror(errno)); exit(STATE_UNKNOWN); } return 0; } /* open file descriptor and attach */ static int dl_open(const char *dev, int unit, int *fd){ dl_attach_req_t *attach_req = (dl_attach_req_t *)ctl_area; if((*fd = open(dev, O_RDWR)) == -1){ printf(_("Error: DLPI stream API failed to get MAC in dl_attach_req/open(%s..): %s.\n"), dev, strerror(errno)); exit(STATE_UNKNOWN); } attach_req->dl_primitive = DL_ATTACH_REQ; attach_req->dl_ppa = unit; put_ctrl(*fd, sizeof(dl_attach_req_t), 0); get_msg(*fd); return check_ctrl(DL_OK_ACK); } /* send DL_BIND_REQ */ static int dl_bind(int fd, int sap, u_char *addr){ dl_bind_req_t *bind_req = (dl_bind_req_t *)ctl_area; dl_bind_ack_t *bind_ack = (dl_bind_ack_t *)ctl_area; bind_req->dl_primitive = DL_BIND_REQ; bind_req->dl_sap = sap; bind_req->dl_max_conind = 1; bind_req->dl_service_mode = DL_CLDLS; bind_req->dl_conn_mgmt = 0; bind_req->dl_xidtest_flg = 0; put_ctrl(fd, sizeof(dl_bind_req_t), 0); get_msg(fd); if (GOT_ERR == check_ctrl(DL_BIND_ACK)){ printf(_("Error: DLPI stream API failed to get MAC in dl_bind/check_ctrl(): %s.\n"), strerror(errno)); exit(STATE_UNKNOWN); } bcopy((u_char *)bind_ack + bind_ack->dl_addr_offset, addr, bind_ack->dl_addr_length); return 0; } /*********************************************************************** * interface: * function mac_addr_dlpi - get the mac address of the interface with * type dev (eg lnc, hme) and unit (0, 1 ..) * * parameter: addr: an array of six bytes, has to be allocated by the caller * * return: 0 if OK, -1 if the address could not be determined * * ***********************************************************************/ long mac_addr_dlpi( const char *dev, int unit, u_char *addr){ int fd; u_char mac_addr[25]; if(GOT_ERR != dl_open(dev, unit, &fd)){ if(GOT_ERR != dl_bind(fd, INSAP, mac_addr)){ bcopy( mac_addr, addr, 6); return 0; } } close(fd); return -1; } /* Kompf 2000-2003 */ #endif /* resolve host name or die (TODO: move this to netutils.c!) */ void resolve_host(const char *in,struct in_addr *out){ struct addrinfo hints, *ai; memset(&hints,0,sizeof(hints)); hints.ai_family=PF_INET; if (getaddrinfo(in,NULL,&hints,&ai) != 0) usage_va(_("Invalid hostname/address - %s"),optarg); memcpy(out,&((struct sockaddr_in *)ai->ai_addr)->sin_addr,sizeof(*out)); freeaddrinfo(ai); } /* parse MAC address string, return 6 bytes (unterminated) or NULL */ unsigned char *mac_aton(const char *string){ static unsigned char result[6]; char tmp[3]; unsigned i, j; for(i=0, j=0; string[i] != '\0' && j < sizeof(result); i++){ /* ignore ':' and any other non-hex character */ if(!isxdigit(string[i]) || !isxdigit(string[i+1])) continue; tmp[0]=string[i]; tmp[1]=string[i+1]; tmp[2]='\0'; result[j]=strtol(tmp,(char **)NULL,16); i++; j++; } return (j==6) ? result : NULL; } void print_hardware_address(const unsigned char *address){ int i; printf(_("Hardware address: ")); for (i=0; i<5; i++) printf("%2.2x:", address[i]); printf("%2.2x", address[i]); putchar('\n'); } /* print usage help */ void print_help(void){ print_revision(progname,revision); printf("Copyright (c) 2001-2004 Ethan Galstad (nagios@nagios.org)\n"); printf (COPYRIGHT, copyright, email); printf("%s\n", _("This plugin tests the availability of DHCP servers on a network.")); printf ("\n\n"); print_usage(); printf (_(UT_HELP_VRSN)); printf (_(UT_VERBOSE)); printf (" %s\n", "-s, --serverip=IPADDRESS"); printf (" %s\n", _("IP address of DHCP server that we must hear from")); printf (" %s\n", "-r, --requestedip=IPADDRESS"); printf (" %s\n", _("IP address that should be offered by at least one DHCP server")); printf (" %s\n", "-t, --timeout=INTEGER"); printf (" %s\n", _("Seconds to wait for DHCPOFFER before timeout occurs")); printf (" %s\n", "-i, --interface=STRING"); printf (" %s\n", _("Interface to to use for listening (i.e. eth0)")); printf (" %s\n", "-m, --mac=STRING"); printf (" %s\n", _("MAC address to use in the DHCP request")); printf (" %s\n", "-u, --unicast"); printf (" %s\n", _("Unicast testing: mimic a DHCP relay, requires -s")); return; } void print_usage(void){ printf (_("Usage:")); printf (" %s [-v] [-u] [-s serverip] [-r requestedip] [-t timeout]\n",progname); printf (" [-i interface] [-m mac]\n"); return; }