From 0453d6d1e206c1f4c156bf73c473608a8c0da4f5 Mon Sep 17 00:00:00 2001 From: Lorenz Kästle <12514511+RincewindsHat@users.noreply.github.com> Date: Tue, 1 Apr 2025 00:44:26 +0200 Subject: Refactor check_dhcp --- plugins-root/check_dhcp.c | 741 +++++++++++++++++++++++++--------------------- 1 file changed, 398 insertions(+), 343 deletions(-) (limited to 'plugins-root/check_dhcp.c') diff --git a/plugins-root/check_dhcp.c b/plugins-root/check_dhcp.c index 70809956..3732d970 100644 --- a/plugins-root/check_dhcp.c +++ b/plugins-root/check_dhcp.c @@ -4,7 +4,7 @@ * * License: GPL * Copyright (c) 2001-2004 Ethan Galstad (nagios@nagios.org) - * Copyright (c) 2001-2023 Monitoring Plugins Development Team + * Copyright (c) 2001-2025 Monitoring Plugins Development Team * * Description: * @@ -34,13 +34,17 @@ *****************************************************************************/ const char *progname = "check_dhcp"; -const char *copyright = "2001-2024"; +const char *copyright = "2001-2025"; const char *email = "devel@monitoring-plugins.org"; -#include "common.h" -#include "netutils.h" -#include "utils.h" +#include "../plugins/common.h" +#include "../plugins/utils.h" +#include "./check_dhcp.d/config.h" +#include "../lib/output.h" +#include "../lib/utils_base.h" +#include "states.h" +#include #include #include #include @@ -111,8 +115,9 @@ static long mac_addr_dlpi(const char *, int, u_char *); /**** Common definitions ****/ -#define OK 0 -#define ERROR -1 +#define OK 0 +#define ERROR -1 +#define MAC_ADDR_LEN 6 /**** DHCP definitions ****/ @@ -149,12 +154,6 @@ typedef struct dhcp_offer_struct { 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 @@ -186,65 +185,60 @@ typedef struct requested_server_struct { #define ETHERNET_HARDWARE_ADDRESS 1 /* used in htype field of dhcp packet */ #define ETHERNET_HARDWARE_ADDRESS_LENGTH 6 /* length of Ethernet hardware addresses */ -static bool unicast = false; /* unicast mode: mimic a DHCP relay */ -static bool exclusive = false; /* exclusive mode aka "rogue DHCP server detection" */ -static struct in_addr my_ip; /* our address (required for relay) */ -static struct in_addr dhcp_ip; /* server to query (if in unicast mode) */ -static unsigned char client_hardware_address[MAX_DHCP_CHADDR_LENGTH] = ""; -static unsigned char *user_specified_mac = NULL; - -static char network_interface_name[IFNAMSIZ] = "eth0"; - -static uint32_t packet_xid = 0; - -static uint32_t dhcp_lease_time = 0; -static uint32_t dhcp_renewal_time = 0; -static uint32_t dhcp_rebinding_time = 0; - -static int dhcpoffer_timeout = 2; - -static dhcp_offer *dhcp_offer_list = NULL; -static requested_server *requested_server_list = NULL; - -static int valid_responses = 0; /* number of valid DHCPOFFERs we received */ -static int requested_servers = 0; -static int requested_responses = 0; - -static bool request_specific_address = false; -static bool received_requested_address = false; static int verbose = 0; -static struct in_addr requested_address; -static int process_arguments(int, char **); -static int call_getopt(int, char **); -static int validate_arguments(int); +typedef struct process_arguments_wrapper { + int error; + check_dhcp_config config; +} process_arguments_wrapper; + +static process_arguments_wrapper process_arguments(int /*argc*/, char ** /*argv*/); void print_usage(void); static void print_help(void); -static void resolve_host(const char *in, struct in_addr *out); -static unsigned char *mac_aton(const char *); -static void print_hardware_address(const unsigned char *); -static int get_hardware_address(int, char *); -static int get_ip_address(int, char *); - -static int send_dhcp_discover(int); -static int get_dhcp_offer(int); - -static int get_results(void); - -static int add_dhcp_offer(struct in_addr, dhcp_packet *); -static int free_dhcp_offer_list(void); -static int free_requested_server_list(void); - -static int create_dhcp_socket(void); -static int close_dhcp_socket(int); -static int send_dhcp_packet(void *, int, int, struct sockaddr_in *); -static int receive_dhcp_packet(void *, int, int, int, struct sockaddr_in *); +static void resolve_host(const char * /*in*/, struct in_addr * /*out*/); +static unsigned char *mac_aton(const char * /*string*/); +static void print_hardware_address(const unsigned char * /*address*/); +static int get_hardware_address(int /*sock*/, char * /*interface_name*/, unsigned char *client_hardware_address); + +typedef struct get_ip_address_wrapper { + int error; + struct in_addr my_ip; +} get_ip_address_wrapper; +static get_ip_address_wrapper get_ip_address(int /*sock*/, char * /*interface_name*/); + +typedef struct send_dhcp_discover_wrapper { + int error; + uint32_t packet_xid; +} send_dhcp_discover_wrapper; +static send_dhcp_discover_wrapper send_dhcp_discover(int socket, bool unicast, struct in_addr dhcp_ip, struct in_addr requested_address, + bool request_specific_address, struct in_addr my_ip, + unsigned char *client_hardware_address); +typedef struct get_dhcp_offer_wrapper { + int error; + int valid_responses; + dhcp_offer *dhcp_offer_list; +} get_dhcp_offer_wrapper; +static get_dhcp_offer_wrapper get_dhcp_offer(int /*sock*/, int dhcpoffer_timeout, uint32_t packet_xid, dhcp_offer *dhcp_offer_list, + const unsigned char *client_hardware_address); + +static mp_subcheck get_results(bool exclusive, int requested_servers, struct in_addr requested_address, bool request_specific_address, + requested_server *requested_server_list, int valid_responses, dhcp_offer *dhcp_offer_list); + +typedef struct add_dhcp_offer_wrapper { + int error; + dhcp_offer *dhcp_offer_list; +} add_dhcp_offer_wrapper; +static add_dhcp_offer_wrapper add_dhcp_offer(struct in_addr /*source*/, dhcp_packet * /*offer_packet*/, dhcp_offer *dhcp_offer_list); +static int free_dhcp_offer_list(dhcp_offer *dhcp_offer_list); +static int free_requested_server_list(requested_server *requested_server_list); + +static int create_dhcp_socket(bool /*unicast*/, char *network_interface_name); +static int close_dhcp_socket(int /*sock*/); +static int send_dhcp_packet(void * /*buffer*/, int /*buffer_size*/, int /*sock*/, struct sockaddr_in * /*dest*/); +static int receive_dhcp_packet(void * /*buffer*/, int /*buffer_size*/, int /*sock*/, int /*timeout*/, struct sockaddr_in * /*address*/); int main(int argc, char **argv) { - int dhcp_socket; - int result = STATE_UNKNOWN; - setlocale(LC_ALL, ""); bindtextdomain(PACKAGE, LOCALEDIR); textdomain(PACKAGE); @@ -252,45 +246,80 @@ int main(int argc, char **argv) { /* Parse extra opts if any */ argv = np_extra_opts(&argc, argv, progname); - if (process_arguments(argc, argv) != OK) { + process_arguments_wrapper tmp = process_arguments(argc, argv); + + if (tmp.error != OK) { usage4(_("Could not parse arguments")); } + check_dhcp_config config = tmp.config; + if (config.output_format_is_set) { + mp_set_format(config.output_format); + } + /* create socket for DHCP communications */ - dhcp_socket = create_dhcp_socket(); + int dhcp_socket = create_dhcp_socket(config.unicast_mode, config.network_interface_name); /* get hardware address of client machine */ - if (user_specified_mac != NULL) { - memcpy(client_hardware_address, user_specified_mac, 6); + unsigned char client_hardware_address[MAX_DHCP_CHADDR_LENGTH] = ""; + if (config.user_specified_mac != NULL) { + memcpy(client_hardware_address, config.user_specified_mac, MAC_ADDR_LEN); } else { - get_hardware_address(dhcp_socket, network_interface_name); + get_hardware_address(dhcp_socket, config.network_interface_name, client_hardware_address); } - if (unicast) { /* get IP address of client machine */ - get_ip_address(dhcp_socket, network_interface_name); + struct in_addr my_ip = {0}; + + if (config.unicast_mode) { /* get IP address of client machine */ + get_ip_address_wrapper tmp_get_ip = get_ip_address(dhcp_socket, config.network_interface_name); + if (tmp_get_ip.error == OK) { + my_ip = tmp_get_ip.my_ip; + } else { + // TODO failed to get own IP + die(STATE_UNKNOWN, "Failed to retrieve my own IP address in unicast mode"); + } } /* send DHCPDISCOVER packet */ - send_dhcp_discover(dhcp_socket); + send_dhcp_discover_wrapper disco_res = send_dhcp_discover(dhcp_socket, config.unicast_mode, config.dhcp_ip, config.requested_address, + config.request_specific_address, my_ip, client_hardware_address); + + if (disco_res.error != OK) { + // DO something? + die(STATE_UNKNOWN, "Failed to send DHCP discover"); + } /* wait for a DHCPOFFER packet */ - get_dhcp_offer(dhcp_socket); + get_dhcp_offer_wrapper offer_res = + get_dhcp_offer(dhcp_socket, config.dhcpoffer_timeout, disco_res.packet_xid, NULL, client_hardware_address); + + int valid_responses = 0; + dhcp_offer *dhcp_offer_list = NULL; + if (offer_res.error == OK) { + valid_responses = offer_res.valid_responses; + dhcp_offer_list = offer_res.dhcp_offer_list; + } else { + die(STATE_UNKNOWN, "Failed to get DHCP offers"); + } /* close socket we created */ close_dhcp_socket(dhcp_socket); - /* determine state/plugin output to return */ - result = get_results(); + mp_check overall = mp_check_init(); + /* determine state/plugin output to return */ + mp_subcheck sc_res = get_results(config.exclusive_mode, config.num_of_requested_servers, config.requested_address, + config.request_specific_address, config.requested_server_list, valid_responses, dhcp_offer_list); + mp_add_subcheck_to_check(&overall, sc_res); /* free allocated memory */ - free_dhcp_offer_list(); - free_requested_server_list(); + free_dhcp_offer_list(dhcp_offer_list); + free_requested_server_list(config.requested_server_list); - return result; + mp_exit(overall); } /* determines hardware address on client machine */ -static int get_hardware_address(int sock, char *interface_name) { +int get_hardware_address(int sock, char *interface_name, unsigned char *client_hardware_address) { #if defined(__linux__) struct ifreq ifr; @@ -304,7 +333,7 @@ static int get_hardware_address(int sock, char *interface_name) { exit(STATE_UNKNOWN); } - memcpy(&client_hardware_address[0], &ifr.ifr_hwaddr.sa_data, 6); + memcpy(&client_hardware_address[0], &ifr.ifr_hwaddr.sa_data, MAC_ADDR_LEN); #elif defined(__bsd__) /* King 2004 see ACKNOWLEDGEMENTS */ @@ -404,7 +433,7 @@ static int get_hardware_address(int sock, char *interface_name) { } /* determines IP address of the client interface */ -static int get_ip_address(int sock, char *interface_name) { +get_ip_address_wrapper get_ip_address(int sock, char *interface_name) { #if defined(SIOCGIFADDR) struct ifreq ifr; @@ -416,29 +445,28 @@ static int get_ip_address(int sock, char *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 + get_ip_address_wrapper result = { + .error = OK, + .my_ip = ((struct sockaddr_in *)&ifr.ifr_addr)->sin_addr, + }; + if (verbose) { - printf(_("Pretending to be relay client %s\n"), inet_ntoa(my_ip)); + printf(_("Pretending to be relay client %s\n"), inet_ntoa(result.my_ip)); } - return OK; + return result; } /* sends a DHCPDISCOVER broadcast message in an attempt to find DHCP servers */ -static 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)); - +static send_dhcp_discover_wrapper send_dhcp_discover(int sock, bool unicast, struct in_addr dhcp_ip, struct in_addr requested_address, + bool request_specific_address, struct in_addr my_ip, + unsigned char *client_hardware_address) { + dhcp_packet discover_packet = {0}; /* boot request flag (backward compatible with BOOTP servers) */ discover_packet.op = BOOTREQUEST; @@ -448,12 +476,15 @@ static int send_dhcp_discover(int sock) { /* length of our hardware address */ discover_packet.hlen = ETHERNET_HARDWARE_ADDRESS_LENGTH; + send_dhcp_discover_wrapper result = { + .error = OK, + }; /* * transaction ID is supposed to be random. */ srand(time(NULL) ^ getpid()); - packet_xid = random(); - discover_packet.xid = htonl(packet_xid); + result.packet_xid = random(); + discover_packet.xid = htonl(result.packet_xid); /*discover_packet.secs=htons(65535);*/ discover_packet.secs = 0xFF; @@ -473,7 +504,7 @@ static int send_dhcp_discover(int sock) { discover_packet.options[2] = '\x53'; discover_packet.options[3] = '\x63'; - opts = 4; + unsigned short 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 */ @@ -497,10 +528,11 @@ static int send_dhcp_discover(int sock) { 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)); + struct sockaddr_in sockaddr_broadcast = { + .sin_family = AF_INET, + .sin_port = htons(DHCP_SERVER_PORT), + .sin_addr.s_addr = unicast ? dhcp_ip.s_addr : INADDR_BROADCAST, + }; if (verbose) { printf(_("DHCPDISCOVER to %s port %d\n"), inet_ntoa(sockaddr_broadcast.sin_addr), ntohs(sockaddr_broadcast.sin_port)); @@ -518,25 +550,21 @@ static int send_dhcp_discover(int sock) { printf("\n\n"); } - return OK; + return result; } /* waits for a DHCPOFFER message from one or more DHCP servers */ -static 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; +get_dhcp_offer_wrapper get_dhcp_offer(int sock, int dhcpoffer_timeout, uint32_t packet_xid, dhcp_offer *dhcp_offer_list, + const unsigned char *client_hardware_address) { time_t start_time; - time_t current_time; - time(&start_time); + int result = OK; + int responses = 0; + int valid_responses = 0; /* receive as many responses as we can */ - for (responses = 0, valid_responses = 0;;) { - + for (;;) { + time_t current_time; time(¤t_time); if ((current_time - start_time) >= dhcpoffer_timeout) { break; @@ -546,9 +574,8 @@ static int get_dhcp_offer(int sock) { printf("\n\n"); } - bzero(&source, sizeof(source)); - bzero(&via, sizeof(via)); - bzero(&offer_packet, sizeof(offer_packet)); + struct sockaddr_in source = {0}; + dhcp_packet offer_packet = {0}; result = OK; result = receive_dhcp_packet(&offer_packet, sizeof(offer_packet), sock, dhcpoffer_timeout, &source); @@ -559,16 +586,16 @@ static int get_dhcp_offer(int sock) { } continue; - } else { - if (verbose) { - printf(_("Result=OK\n")); - } - - responses++; } + 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 */ + struct sockaddr_in via = {0}; memcpy(&via, &source, sizeof(source)); if (verbose) { @@ -593,12 +620,12 @@ static int get_dhcp_offer(int sock) { printf("DHCPOFFER chaddr: "); } - for (x = 0; x < ETHERNET_HARDWARE_ADDRESS_LENGTH; x++) { + for (int i = 0; i < ETHERNET_HARDWARE_ADDRESS_LENGTH; i++) { if (verbose) { - printf("%02X", (unsigned char)offer_packet.chaddr[x]); + printf("%02X", offer_packet.chaddr[i]); } - if (offer_packet.chaddr[x] != client_hardware_address[x]) { + if (offer_packet.chaddr[i] != client_hardware_address[i]) { result = ERROR; } } @@ -621,7 +648,12 @@ static int get_dhcp_offer(int sock) { printf("DHCPOFFER giaddr: %s\n", inet_ntoa(offer_packet.giaddr)); } - add_dhcp_offer(source.sin_addr, &offer_packet); + add_dhcp_offer_wrapper add_res = add_dhcp_offer(source.sin_addr, &offer_packet, dhcp_offer_list); + if (add_res.error != OK) { + // TODO + } else { + dhcp_offer_list = add_res.dhcp_offer_list; + } valid_responses++; } @@ -631,14 +663,17 @@ static int get_dhcp_offer(int sock) { printf(_("Valid responses for this machine: %d\n"), valid_responses); } - return OK; + get_dhcp_offer_wrapper ret_val = { + .error = OK, + .valid_responses = valid_responses, + .dhcp_offer_list = dhcp_offer_list, + }; + return ret_val; } /* sends a DHCP packet */ -static 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)); +int send_dhcp_packet(void *buffer, int buffer_size, int sock, struct sockaddr_in *dest) { + int result = sendto(sock, (char *)buffer, buffer_size, 0, (struct sockaddr *)dest, sizeof(*dest)); if (verbose) { printf(_("send_dhcp_packet result: %d\n"), result); @@ -652,23 +687,19 @@ static int send_dhcp_packet(void *buffer, int buffer_size, int sock, struct sock } /* receives a DHCP packet */ -static 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; - +int receive_dhcp_packet(void *buffer, int buffer_size, int sock, int timeout, struct sockaddr_in *address) { /* wait for data to arrive (up time timeout) */ - tv.tv_sec = timeout; - tv.tv_usec = 0; + struct timeval timeout_val = { + .tv_sec = timeout, + .tv_usec = 0, + }; + fd_set readfds; FD_ZERO(&readfds); + fd_set oobfds; FD_ZERO(&oobfds); FD_SET(sock, &readfds); FD_SET(sock, &oobfds); - nfound = select(sock + 1, &readfds, NULL, &oobfds, &tv); + int nfound = select(sock + 1, &readfds, NULL, &oobfds, &timeout_val); /* make sure some data has arrived */ if (!FD_ISSET(sock, &readfds)) { @@ -678,51 +709,44 @@ static int receive_dhcp_packet(void *buffer, int buffer_size, int sock, int time 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)); - } + struct sockaddr_in source_address = {0}; + socklen_t address_size = sizeof(source_address); + int recv_result = recvfrom(sock, (char *)buffer, buffer_size, 0, (struct sockaddr *)&source_address, &address_size); + if (verbose) { + printf("recv_result: %d\n", recv_result); + } - memcpy(address, &source_address, sizeof(source_address)); - return OK; + if (recv_result == -1) { + if (verbose) { + printf(_("recvfrom() failed, ")); + printf("errno: (%d) -> %s\n", errno, strerror(errno)); } + return ERROR; + } + 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; } /* creates a socket for DHCP communication */ -static int create_dhcp_socket(void) { - struct sockaddr_in myname; - struct ifreq interface; - int sock; - int flag = 1; - +int create_dhcp_socket(bool unicast, char *network_interface_name) { /* 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)); + struct sockaddr_in myname = { + .sin_family = AF_INET, + .sin_port = htons(unicast ? DHCP_SERVER_PORT : DHCP_CLIENT_PORT), + // TODO previously the next line was trying to use our own IP, we was not set + // until some point later, so it was removed. Recheck whether it is actually + // necessary/useful + .sin_addr.s_addr = INADDR_ANY, + }; /* create a socket for DHCP communications */ - sock = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP); + int sock = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP); if (sock < 0) { printf(_("Error: Could not create socket!\n")); exit(STATE_UNKNOWN); @@ -733,7 +757,7 @@ static int create_dhcp_socket(void) { } /* set the reuse address flag so we don't get errors when restarting */ - flag = 1; + int 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); @@ -745,6 +769,7 @@ static int create_dhcp_socket(void) { exit(STATE_UNKNOWN); } + struct ifreq interface; /* bind socket to interface */ #if defined(__linux__) strncpy(interface.ifr_ifrn.ifrn_name, network_interface_name, IFNAMSIZ - 1); @@ -769,18 +794,14 @@ static int create_dhcp_socket(void) { } /* closes DHCP socket */ -static int close_dhcp_socket(int sock) { - +int close_dhcp_socket(int sock) { close(sock); - return OK; } /* adds a requested server address to list in memory */ -static int add_requested_server(struct in_addr server_address) { - requested_server *new_server; - - new_server = (requested_server *)malloc(sizeof(requested_server)); +int add_requested_server(struct in_addr server_address, int *requested_servers, requested_server **requested_server_list) { + requested_server *new_server = (requested_server *)malloc(sizeof(requested_server)); if (new_server == NULL) { return ERROR; } @@ -788,10 +809,10 @@ static int add_requested_server(struct in_addr server_address) { new_server->server_address = server_address; new_server->answered = false; - new_server->next = requested_server_list; - requested_server_list = new_server; + new_server->next = *requested_server_list; + *requested_server_list = new_server; - requested_servers++; + *requested_servers += 1; if (verbose) { printf(_("Requested server address: %s\n"), inet_ntoa(new_server->server_address)); @@ -801,29 +822,31 @@ static int add_requested_server(struct in_addr server_address) { } /* adds a DHCP OFFER to list in memory */ -static 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}; - +add_dhcp_offer_wrapper add_dhcp_offer(struct in_addr source, dhcp_packet *offer_packet, dhcp_offer *dhcp_offer_list) { if (offer_packet == NULL) { - return ERROR; + add_dhcp_offer_wrapper tmp = { + .error = ERROR, + }; + return tmp; } + uint32_t dhcp_lease_time = 0; + uint32_t dhcp_renewal_time = 0; + uint32_t dhcp_rebinding_time = 0; + dhcp_offer *new_offer; + struct in_addr serv_ident = {0}; /* process all DHCP options present in the packet */ - for (x = 4; x < MAX_DHCP_OPTIONS_LENGTH - 1;) { + for (int dchp_opt_idx = 4; dchp_opt_idx < MAX_DHCP_OPTIONS_LENGTH - 1;) { - if ((int)offer_packet->options[x] == -1) { + if ((int)offer_packet->options[dchp_opt_idx] == -1) { break; } /* get option type */ - option_type = offer_packet->options[x++]; + unsigned option_type = offer_packet->options[dchp_opt_idx++]; /* get option length */ - option_length = offer_packet->options[x++]; + unsigned option_length = offer_packet->options[dchp_opt_idx++]; if (verbose) { printf("Option: %d (0x%02X)\n", option_type, option_length); @@ -832,27 +855,27 @@ static int add_dhcp_offer(struct in_addr source, dhcp_packet *offer_packet) { /* get option data */ switch (option_type) { case DHCP_OPTION_LEASE_TIME: - memcpy(&dhcp_lease_time, &offer_packet->options[x], sizeof(dhcp_lease_time)); + memcpy(&dhcp_lease_time, &offer_packet->options[dchp_opt_idx], 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)); + memcpy(&dhcp_renewal_time, &offer_packet->options[dchp_opt_idx], 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)); + memcpy(&dhcp_rebinding_time, &offer_packet->options[dchp_opt_idx], 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)); + memcpy(&serv_ident.s_addr, &offer_packet->options[dchp_opt_idx], 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; + dchp_opt_idx += 1; } else { - x += option_length; + dchp_opt_idx += option_length; } } @@ -876,7 +899,10 @@ static int add_dhcp_offer(struct in_addr source, dhcp_packet *offer_packet) { new_offer = (dhcp_offer *)malloc(sizeof(dhcp_offer)); if (new_offer == NULL) { - return ERROR; + add_dhcp_offer_wrapper tmp = { + .error = ERROR, + }; + return tmp; } /* @@ -907,15 +933,18 @@ static int add_dhcp_offer(struct in_addr source, dhcp_packet *offer_packet) { new_offer->next = dhcp_offer_list; dhcp_offer_list = new_offer; - return OK; + add_dhcp_offer_wrapper result = { + .error = OK, + .dhcp_offer_list = dhcp_offer_list, + }; + + return result; } /* frees memory allocated to DHCP OFFER list */ -static int free_dhcp_offer_list(void) { - dhcp_offer *this_offer; +int free_dhcp_offer_list(dhcp_offer *dhcp_offer_list) { dhcp_offer *next_offer; - - for (this_offer = dhcp_offer_list; this_offer != NULL; this_offer = next_offer) { + for (dhcp_offer *this_offer = dhcp_offer_list; this_offer != NULL; this_offer = next_offer) { next_offer = this_offer->next; free(this_offer); } @@ -924,11 +953,9 @@ static int free_dhcp_offer_list(void) { } /* frees memory allocated to requested server list */ -static int free_requested_server_list(void) { - requested_server *this_server; +int free_requested_server_list(requested_server *requested_server_list) { requested_server *next_server; - - for (this_server = requested_server_list; this_server != NULL; this_server = next_server) { + for (requested_server *this_server = requested_server_list; this_server != NULL; this_server = next_server) { next_server = this_server->next; free(this_server); } @@ -937,22 +964,39 @@ static int free_requested_server_list(void) { } /* gets state and plugin output to return */ -static 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; +mp_subcheck get_results(bool exclusive, const int requested_servers, const struct in_addr requested_address, bool request_specific_address, + requested_server *requested_server_list, int valid_responses, dhcp_offer *dhcp_offer_list) { + mp_subcheck sc_dhcp_results = mp_subcheck_init(); + sc_dhcp_results = mp_set_subcheck_default_state(sc_dhcp_results, STATE_OK); - /* checks responses from requested servers */ - requested_responses = 0; - if (requested_servers > 0) { + /* we didn't receive any DHCPOFFERs */ + if (dhcp_offer_list == NULL) { + sc_dhcp_results = mp_set_subcheck_state(sc_dhcp_results, STATE_CRITICAL); + xasprintf(&sc_dhcp_results.output, "%s", "No DHCP offers were received"); + return sc_dhcp_results; + } - for (temp_server = requested_server_list; temp_server != NULL; temp_server = temp_server->next) { + if (valid_responses == 0) { + // No valid responses at all, so early exit here + sc_dhcp_results = mp_set_subcheck_state(sc_dhcp_results, STATE_CRITICAL); + xasprintf(&sc_dhcp_results.output, "No valid responses received"); + return sc_dhcp_results; + } - for (temp_offer = dhcp_offer_list; temp_offer != NULL; temp_offer = temp_offer->next) { + if (valid_responses == 1) { + xasprintf(&sc_dhcp_results.output, "Received %d DHCPOFFER", valid_responses); + } else { + xasprintf(&sc_dhcp_results.output, "Received %d DHCPOFFERs", valid_responses); + } + bool received_requested_address = false; + dhcp_offer *undesired_offer = NULL; + uint32_t max_lease_time = 0; + /* checks responses from requested servers */ + int requested_responses = 0; + if (requested_servers > 0) { + for (requested_server *temp_server = requested_server_list; temp_server != NULL; temp_server = temp_server->next) { + for (dhcp_offer *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; @@ -963,7 +1007,7 @@ static int get_results(void) { received_requested_address = true; } - /* see if the servers we wanted a response from talked to us or not */ + /* 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)); @@ -973,6 +1017,7 @@ static int get_results(void) { } printf(_("\n")); } + if (!temp_server->answered) { requested_responses++; temp_server->answered = true; @@ -983,19 +1028,32 @@ static int get_results(void) { } /* exclusive mode: check for undesired offers */ - for (temp_offer = dhcp_offer_list; temp_offer != NULL; temp_offer = temp_offer->next) { + for (dhcp_offer *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 { + mp_subcheck sc_rqust_srvs = mp_subcheck_init(); + xasprintf(&sc_rqust_srvs.output, "%d of %d requested servers responded", requested_responses, requested_servers); - for (temp_offer = dhcp_offer_list; temp_offer != NULL; temp_offer = temp_offer->next) { + if (requested_responses == requested_servers) { + sc_rqust_srvs = mp_set_subcheck_state(sc_rqust_srvs, STATE_OK); + } else if (requested_responses == 0) { + sc_rqust_srvs = mp_set_subcheck_state(sc_rqust_srvs, STATE_CRITICAL); + } else if (requested_responses < requested_servers) { + sc_rqust_srvs = mp_set_subcheck_state(sc_rqust_srvs, STATE_WARNING); + } else { + // We received more(!) responses than we asked for? + // This case shouldn't happen, but is here for completion + sc_rqust_srvs = mp_set_subcheck_state(sc_rqust_srvs, STATE_WARNING); + } + mp_add_subcheck_to_subcheck(&sc_dhcp_results, sc_rqust_srvs); + } else { + /* else check and see if we got our requested address from any server */ + for (dhcp_offer *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; @@ -1008,79 +1066,77 @@ static int get_results(void) { } } - 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 (max_lease_time == DHCP_INFINITE_TIME) { + xasprintf(&sc_dhcp_results.output, "%s, max lease time = Infinity", sc_dhcp_results.output); + } else { + xasprintf(&sc_dhcp_results.output, "%s, max lease time = %" PRIu32 " seconds", sc_dhcp_results.output, max_lease_time); } - if (exclusive && undesired_offer) { - result = STATE_CRITICAL; - } + if (exclusive) { + mp_subcheck sc_rogue_server = mp_subcheck_init(); - 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: "); - } + if (undesired_offer != NULL) { + // We wanted to get a DHCPOFFER exclusively from one machine, but another one + // sent one (too) + sc_rogue_server = mp_set_subcheck_state(sc_rogue_server, STATE_CRITICAL); - /* we didn't receive any DHCPOFFERs */ - if (dhcp_offer_list == NULL) { - printf(_("No DHCPOFFERs were received.\n")); - return result; - } + // Get the addresses for printout + // 1.address of the sending server + char server_address[INET_ADDRSTRLEN]; + const char *server_address_transformed = + inet_ntop(AF_INET, &undesired_offer->server_address, server_address, sizeof(server_address)); + + if (server_address != server_address_transformed) { + die(STATE_UNKNOWN, "inet_ntop failed"); + } - printf(_("Received %d DHCPOFFER(s)"), valid_responses); + // 2.address offered + char offered_address[INET_ADDRSTRLEN]; + const char *offered_address_transformed = + inet_ntop(AF_INET, &undesired_offer->offered_address, offered_address, sizeof(offered_address)); - 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 (offered_address != offered_address_transformed) { + die(STATE_UNKNOWN, "inet_ntop failed"); + } - if (requested_servers > 0) { - printf(_(", %s%d of %d requested servers responded"), - ((requested_responses < requested_servers) && requested_responses > 0) ? "only " : "", requested_responses, - requested_servers); + xasprintf(&sc_rogue_server.output, "Rogue DHCP Server detected! Server %s offered %s", server_address, offered_address); + } else { + sc_rogue_server = mp_set_subcheck_state(sc_rogue_server, STATE_OK); + xasprintf(&sc_rogue_server.output, "No Rogue DHCP Server detected"); + } + mp_add_subcheck_to_subcheck(&sc_dhcp_results, sc_rogue_server); } if (request_specific_address) { - printf(_(", requested address (%s) was %soffered"), inet_ntoa(requested_address), (received_requested_address) ? "" : _("not ")); - } + mp_subcheck sc_rqustd_addr = mp_subcheck_init(); - printf(_(", max lease time = ")); - if (max_lease_time == DHCP_INFINITE_TIME) { - printf(_("Infinity")); - } else { - printf("%lu sec", (unsigned long)max_lease_time); - } + if (received_requested_address) { + sc_rqustd_addr = mp_set_subcheck_state(sc_rqustd_addr, STATE_OK); + xasprintf(&sc_rqustd_addr.output, "Requested address (%s) was offered", inet_ntoa(requested_address)); + } else { + sc_rqustd_addr = mp_set_subcheck_state(sc_rqustd_addr, STATE_WARNING); + xasprintf(&sc_rqustd_addr.output, "Requested address (%s) was NOT offered", inet_ntoa(requested_address)); + } - printf(".\n"); + mp_add_subcheck_to_subcheck(&sc_dhcp_results, sc_rqustd_addr); + } - return result; + return sc_dhcp_results; } /* process command-line arguments */ -static int process_arguments(int argc, char **argv) { +process_arguments_wrapper process_arguments(int argc, char **argv) { if (argc < 1) { - return ERROR; + process_arguments_wrapper tmp = { + .error = ERROR, + }; + return tmp; } - call_getopt(argc, argv); - return validate_arguments(argc); -} + enum { + output_format_index = CHAR_MAX + 1, + }; -static 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'}, @@ -1092,65 +1148,55 @@ static int call_getopt(int argc, char **argv) { {"verbose", no_argument, 0, 'v'}, {"version", no_argument, 0, 'V'}, {"help", no_argument, 0, 'h'}, + {"output-format", required_argument, 0, output_format_index}, {0, 0, 0, 0}}; - int c = 0; + check_dhcp_config config = check_dhcp_config_init(); + int option_char = 0; while (true) { - c = getopt_long(argc, argv, "+hVvxt:s:r:t:i:m:u", long_options, &option_index); + option_char = getopt_long(argc, argv, "+hVvxt:s:r:t:i:m:u", long_options, &option_index); - if (c == -1 || c == EOF || c == 1) { + if (option_char == -1 || option_char == EOF || option_char == 1) { break; } - switch (c) { - + switch (option_char) { case 's': /* DHCP server address */ - resolve_host(optarg, &dhcp_ip); - add_requested_server(dhcp_ip); + resolve_host(optarg, &config.dhcp_ip); + add_requested_server(config.dhcp_ip, &config.num_of_requested_servers, &config.requested_server_list); break; case 'r': /* address we are requested from DHCP servers */ - resolve_host(optarg, &requested_address); - request_specific_address = true; + resolve_host(optarg, &config.requested_address); + config.request_specific_address = true; break; case 't': /* timeout */ - - /* - if(is_intnonneg(optarg)) - */ if (atoi(optarg) > 0) { - dhcpoffer_timeout = atoi(optarg); + config.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) { + if ((config.user_specified_mac = mac_aton(optarg)) == NULL) { usage("Cannot parse MAC address.\n"); } if (verbose) { - print_hardware_address(user_specified_mac); + print_hardware_address(config.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'; - + strncpy(config.network_interface_name, optarg, sizeof(config.network_interface_name) - 1); + config.network_interface_name[sizeof(config.network_interface_name) - 1] = '\x0'; break; case 'u': /* unicast testing */ - unicast = true; + config.unicast_mode = true; break; + case 'x': /* exclusive testing aka "rogue DHCP server detection" */ - exclusive = true; + config.exclusive_mode = true; break; case 'V': /* version */ @@ -1164,6 +1210,18 @@ static int call_getopt(int argc, char **argv) { case 'v': /* verbose */ verbose = 1; break; + case output_format_index: { + parsed_output_format parser = mp_parse_output_format(optarg); + if (!parser.parsing_success) { + // TODO List all available formats here, maybe add anothoer usage function + printf("Invalid output format: %s\n", optarg); + exit(STATE_UNKNOWN); + } + + config.output_format_is_set = true; + config.output_format = parser.output_format; + break; + } case '?': /* help */ usage5(); break; @@ -1172,16 +1230,16 @@ static int call_getopt(int argc, char **argv) { break; } } - return optind; -} - -static int validate_arguments(int argc) { if (argc - optind > 0) { usage(_("Got unexpected non-option argument")); } - return OK; + process_arguments_wrapper result = { + .config = config, + .error = OK, + }; + return result; } #if defined(__sun__) || defined(__solaris__) || defined(__hpux__) @@ -1300,7 +1358,7 @@ static int dl_bind(int fd, int sap, u_char *addr) { * ***********************************************************************/ -static long mac_addr_dlpi(const char *dev, int unit, u_char *addr) { +long mac_addr_dlpi(const char *dev, int unit, u_char *addr) { int fd; u_char mac_addr[25]; @@ -1319,26 +1377,27 @@ static long mac_addr_dlpi(const char *dev, int unit, u_char *addr) { #endif /* resolve host name or die (TODO: move this to netutils.c!) */ -static void resolve_host(const char *in, struct in_addr *out) { - struct addrinfo hints, *ai; +void resolve_host(const char *name, struct in_addr *out) { + struct addrinfo hints = { + .ai_family = PF_INET, + }; + struct addrinfo *addr_info; - memset(&hints, 0, sizeof(hints)); - hints.ai_family = PF_INET; - if (getaddrinfo(in, NULL, &hints, &ai) != 0) { + if (getaddrinfo(name, NULL, &hints, &addr_info) != 0) { usage_va(_("Invalid hostname/address - %s"), optarg); } - memcpy(out, &((struct sockaddr_in *)ai->ai_addr)->sin_addr, sizeof(*out)); - freeaddrinfo(ai); + memcpy(out, &((struct sockaddr_in *)addr_info->ai_addr)->sin_addr, sizeof(*out)); + freeaddrinfo(addr_info); } /* parse MAC address string, return 6 bytes (unterminated) or NULL */ -static unsigned char *mac_aton(const char *string) { - static unsigned char result[6]; +unsigned char *mac_aton(const char *string) { + static unsigned char result[MAC_ADDR_LEN]; char tmp[3]; - unsigned i, j; + unsigned byte_counter = 0; - for (i = 0, j = 0; string[i] != '\0' && j < sizeof(result); i++) { + for (int i = 0; string[i] != '\0' && byte_counter < sizeof(result); i++) { /* ignore ':' and any other non-hex character */ if (!isxdigit(string[i]) || !isxdigit(string[i + 1])) { continue; @@ -1346,27 +1405,25 @@ static unsigned char *mac_aton(const char *string) { tmp[0] = string[i]; tmp[1] = string[i + 1]; tmp[2] = '\0'; - result[j] = strtol(tmp, (char **)NULL, 16); + result[byte_counter] = strtol(tmp, (char **)NULL, 16); i++; - j++; + byte_counter++; } - return (j == 6) ? result : NULL; + return (byte_counter == MAC_ADDR_LEN) ? result : NULL; } -static void print_hardware_address(const unsigned char *address) { - int i; +void print_hardware_address(const unsigned char *address) { printf(_("Hardware address: ")); - for (i = 0; i < 5; i++) { - printf("%2.2x:", address[i]); + for (int addr_idx = 0; addr_idx < MAC_ADDR_LEN; addr_idx++) { + printf("%2.2x:", address[addr_idx]); } - printf("%2.2x", address[i]); putchar('\n'); } /* print usage help */ -static void print_help(void) { +void print_help(void) { print_revision(progname, NP_VERSION); @@ -1382,6 +1439,7 @@ static void print_help(void) { printf(UT_HELP_VRSN); printf(UT_EXTRA_OPTS); + printf(UT_OUTPUT_FORMAT); printf(UT_VERBOSE); printf(" %s\n", "-s, --serverip=IPADDRESS"); @@ -1400,7 +1458,6 @@ static void print_help(void) { printf(" %s\n", _("Only requested DHCP server may response (rogue DHCP server detection), requires -s")); printf(UT_SUPPORT); - return; } void print_usage(void) { @@ -1408,6 +1465,4 @@ 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; } -- cgit v1.2.3-74-g34f1