diff options
author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-13 11:48:22 +0000 |
---|---|---|
committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-13 11:48:22 +0000 |
commit | 7373ce3d6988706388f136e1c06afd20a3e8d5be (patch) | |
tree | e9ae5af7d102667e5706187646db45de8238e8c4 /plugins-root/check_dhcp.c | |
parent | Initial commit. (diff) | |
download | monitoring-plugins-upstream.tar.xz monitoring-plugins-upstream.zip |
Adding upstream version 2.3.5.upstream/2.3.5upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | plugins-root/check_dhcp.c | 1412 |
1 files changed, 1412 insertions, 0 deletions
diff --git a/plugins-root/check_dhcp.c b/plugins-root/check_dhcp.c new file mode 100644 index 0000000..6b07df5 --- /dev/null +++ b/plugins-root/check_dhcp.c @@ -0,0 +1,1412 @@ +/***************************************************************************** + * + * Monitoring check_dhcp plugin + * + * License: GPL + * Copyright (c) 2001-2004 Ethan Galstad (nagios@nagios.org) + * Copyright (c) 2001-2007 Monitoring Plugins Development Team + * + * Description: + * + * This file contains the check_dhcp plugin + * + * This plugin tests the availability of DHCP servers on a network. + * + * 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. + * + * + * 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 3 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, see <http://www.gnu.org/licenses/>. + * + * + *****************************************************************************/ + +const char *progname = "check_dhcp"; +const char *copyright = "2001-2023"; +const char *email = "devel@monitoring-plugins.org"; + +#include "common.h" +#include "netutils.h" +#include "utils.h" + +#include <ctype.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <errno.h> +#include <unistd.h> +#include <sys/time.h> +#include <sys/ioctl.h> +#include <fcntl.h> +#include <getopt.h> +#include <sys/socket.h> +#include <sys/types.h> +#include <netdb.h> +#include <netinet/in.h> +#include <net/if.h> +#include <arpa/inet.h> + +#if HAVE_SYS_SOCKIO_H +#include <sys/sockio.h> +#endif // HAVE_SYS_SOCKIO_H + +#if defined( __linux__ ) + +#include <linux/if_ether.h> +#include <features.h> + +#elif defined (__bsd__) + +#include <netinet/if_ether.h> +#include <sys/param.h> +#include <sys/sysctl.h> +#include <net/if_dl.h> + +#elif defined(__sun__) || defined(__solaris__) || defined(__hpux__) + +#define INSAP 22 +#define OUTSAP 24 + +#include <signal.h> +#include <ctype.h> +#include <sys/stropts.h> +#include <sys/poll.h> +#include <sys/dlpi.h> + +#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 + +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 // __sun__ || __solaris__ || __hpux + + + +/**** Common definitions ****/ + +#define OK 0 +#define ERROR -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{ + uint8_t op; /* packet type */ + uint8_t htype; /* type of hardware address for this machine (Ethernet, etc) */ + uint8_t hlen; /* length of hardware address (of this machine) */ + uint8_t hops; /* hops */ + uint32_t xid; /* random transaction id number - chosen by this machine */ + uint16_t secs; /* seconds used in timing */ + uint16_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 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 */ + 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 */ + uint32_t lease_time; /* lease time in seconds */ + uint32_t renewal_time; /* renewal time in seconds */ + uint32_t rebinding_time; /* rebinding time in seconds */ + bool desired; /* is this offer desired (necessary in exclusive mode) */ + struct dhcp_offer_struct *next; +}dhcp_offer; + + +typedef struct requested_server_struct{ + struct in_addr server_address; + bool 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_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 */ + +bool unicast = false; /* unicast mode: mimic a DHCP relay */ +bool exclusive = false; /* exclusive mode aka "rogue DHCP server detection" */ +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"; + +uint32_t packet_xid=0; + +uint32_t dhcp_lease_time=0; +uint32_t dhcp_renewal_time=0; +uint32_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; + +bool request_specific_address=false; +bool 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(int); +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; + + setlocale (LC_ALL, ""); + bindtextdomain (PACKAGE, LOCALEDIR); + textdomain (PACKAGE); + + /* Parse extra opts if any */ + argv=np_extra_opts(&argc, argv, progname); + + 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 */ + + size_t len; + int mib[6]; + 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; + + /* get last number from interfacename, eg lnc0, e1000g0*/ + int i; + p = interface_name + strlen(interface_name) -1; + for(i = strlen(interface_name) -1; i > 0; p--) { + if(isalpha(*p)) + break; + } + p++; + if( p != interface_name ){ + unit = atoi(p) ; + 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. + */ + srand(time(NULL)^getpid()); + packet_xid=random(); + discover_packet.xid=htonl(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){ + 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(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<ETHERNET_HARDWARE_ADDRESS_LENGTH;x++){ + if(verbose) + printf("%02X",(unsigned char)offer_packet.chaddr[x]); + + if(offer_packet.chaddr[x]!=client_hardware_address[x]) + result=ERROR; + } + if(verbose) + printf("\n"); + + if(result==ERROR){ + if(verbose) + 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)); + printf("DHCPOFFER yiaddr: %s\n",inet_ntoa(offer_packet.yiaddr)); + printf("DHCPOFFER siaddr: %s\n",inet_ntoa(offer_packet.siaddr)); + printf("DHCPOFFER giaddr: %s\n",inet_ntoa(offer_packet.giaddr)); + } + + add_dhcp_offer(source.sin_addr,&offer_packet); + + valid_responses++; + } + + if(verbose){ + printf(_("Total responses seen on the wire: %d\n"),responses); + printf(_("Valid responses for this machine: %d\n"),valid_responses); + } + + return OK; +} + + + +/* sends a DHCP packet */ +int send_dhcp_packet(void *buffer, int buffer_size, int sock, struct sockaddr_in *dest){ + int result; + + result=sendto(sock,(char *)buffer,buffer_size,0,(struct sockaddr *)dest,sizeof(*dest)); + + if(verbose) + printf(_("send_dhcp_packet result: %d\n"),result); + + if(result<0) + return ERROR; + + return OK; +} + + + +/* receives a DHCP packet */ +int receive_dhcp_packet(void *buffer, int buffer_size, int sock, int timeout, struct sockaddr_in *address){ + struct timeval tv; + fd_set readfds; + fd_set oobfds; + int recv_result; + socklen_t address_size; + struct sockaddr_in source_address; + int nfound; + + + /* wait for data to arrive (up time timeout) */ + tv.tv_sec=timeout; + tv.tv_usec=0; + FD_ZERO(&readfds); + FD_ZERO(&oobfds); + FD_SET(sock,&readfds); + FD_SET(sock,&oobfds); + nfound = select(sock+1,&readfds,NULL,&oobfds,&tv); + + /* make sure some data has arrived */ + if(!FD_ISSET(sock,&readfds)){ + if(verbose) + printf(_("No (more) data received (nfound: %d)\n"), nfound); + return ERROR; + } + + else{ + bzero(&source_address,sizeof(source_address)); + address_size=sizeof(source_address); + recv_result=recvfrom(sock,(char *)buffer,buffer_size,0,(struct sockaddr *)&source_address,&address_size); + if(verbose) + printf("recv_result: %d\n",recv_result); + + if(recv_result==-1){ + if(verbose){ + printf(_("recvfrom() failed, ")); + printf("errno: (%d) -> %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(!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__) + 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;x<MAX_DHCP_OPTIONS_LENGTH-1;){ + + if((int)offer_packet->options[x]==-1) + 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==0) /* "pad" option, see RFC 2132 (3.1) */ + x+=1; + else + 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 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; + new_offer->desired=false; /* exclusive mode: we'll check that in get_results */ + + + 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, *undesired_offer=NULL; + requested_server *temp_server; + int result; + uint32_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){ + requested_responses++; + temp_server->answered=true; + temp_offer->desired=true; + } + } + } + } + + /* exclusive mode: check for undesired offers */ + for(temp_offer=dhcp_offer_list;temp_offer!=NULL;temp_offer=temp_offer->next) { + if (!temp_offer->desired) { + undesired_offer=temp_offer; /* Checks only for the first undesired offer */ + break; /* no further checks needed */ + } + } + } + + /* 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_responses<requested_servers) + result=STATE_WARNING; + else if(request_specific_address && !received_requested_address) + result=STATE_WARNING; + + if(exclusive && undesired_offer) + result=STATE_CRITICAL; + + if(result==0) /* garrett honeycutt 2005 */ + printf("OK: "); + else if(result==1) + printf("WARNING: "); + else if(result==2) + printf("CRITICAL: "); + else if(result==3) + printf("UNKNOWN: "); + + /* we didn't receive any DHCPOFFERs */ + if(dhcp_offer_list==NULL){ + printf(_("No DHCPOFFERs were received.\n")); + return result; + } + + printf(_("Received %d DHCPOFFER(s)"),valid_responses); + + + if(exclusive && undesired_offer){ + printf(_(", Rogue DHCP Server detected! Server %s"),inet_ntoa(undesired_offer->server_address)); + printf(_(" offered %s \n"),inet_ntoa(undesired_offer->offered_address)); + return result; + } + + if(requested_servers>0) + printf(_(", %s%d of %d requested servers responded"),((requested_responses<requested_servers) && requested_responses>0)?"only ":"",requested_responses,requested_servers); + + if(request_specific_address) + printf(_(", requested address (%s) was %soffered"),inet_ntoa(requested_address),(received_requested_address)?"":_("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){ + if(argc<1) + return ERROR; + + call_getopt(argc,argv); + return validate_arguments(argc); +} + + + +int call_getopt(int argc, char **argv){ + extern int optind; + int option_index = 0; + static struct option long_options[] = + { + {"serverip", required_argument,0,'s'}, + {"requestedip", required_argument,0,'r'}, + {"timeout", required_argument,0,'t'}, + {"interface", required_argument,0,'i'}, + {"mac", required_argument,0,'m'}, + {"unicast", no_argument, 0,'u'}, + {"exclusive", no_argument, 0,'x'}, + {"verbose", no_argument, 0,'v'}, + {"version", no_argument, 0,'V'}, + {"help", no_argument, 0,'h'}, + {0,0,0,0} + }; + + int c=0; + while(true){ + c=getopt_long(argc,argv,"+hVvxt:s:r:t:i:m:u",long_options,&option_index); + + if(c==-1||c==EOF||c==1) + break; + + switch(c){ + + case 's': /* DHCP server address */ + resolve_host(optarg,&dhcp_ip); + add_requested_server(dhcp_ip); + break; + + case 'r': /* address we are requested from DHCP servers */ + resolve_host(optarg,&requested_address); + request_specific_address=true; + break; + + case 't': /* timeout */ + + /* + if(is_intnonneg(optarg)) + */ + if(atoi(optarg)>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=true; + break; + case 'x': /* exclusive testing aka "rogue DHCP server detection" */ + exclusive=true; + break; + + case 'V': /* version */ + print_revision(progname, NP_VERSION); + exit(STATE_UNKNOWN); + + case 'h': /* help */ + print_help(); + exit(STATE_UNKNOWN); + + case 'v': /* verbose */ + verbose=1; + break; + case '?': /* help */ + usage5 (); + break; + + default: + break; + } + } + return optind; +} + + +int validate_arguments(int argc){ + + if(argc - optind > 0) + usage(_("Got unexpected non-option argument")); + + 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, NP_VERSION); + + 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_EXTRA_OPTS); + + 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")); + printf (" %s\n", "-x, --exclusive"); + printf (" %s\n", _("Only requested DHCP server may response (rogue DHCP server detection), requires -s")); + + printf (UT_SUPPORT); + return; +} + + +void +print_usage(void){ + + printf ("%s\n", _("Usage:")); + printf (" %s [-v] [-u] [-x] [-s serverip] [-r requestedip] [-t timeout]\n",progname); + printf (" [-i interface] [-m mac]\n"); + + return; +} |