/* * A rewrite of Darren Reed's original res.c As there is nothing * left of Darren's original code, this is now licensed by the hybrid group. * (Well, some of the function names are the same, and bits of the structs..) * You can use it where it is useful, free even. Buy us a beer and stuff. * * The authors takes no responsibility for any damage or loss * of property which results from the use of this software. * * July 1999 - Rewrote a bunch of stuff here. Change hostent builder code, * added callbacks and reference counting of returned hostents. * --Bleep (Thomas Helvey ) * * This was all needlessly complicated for irc. Simplified. No more hostent * All we really care about is the IP -> hostname mappings. Thats all. * * Apr 28, 2003 --cryogen and Dianora */ /** @file * @brief IRC resolver functions. * @version $Id: ircd_res.c 1764 2007-02-25 15:41:49Z entrope $ */ #include "client.h" #include "ircd_alloc.h" #include "ircd_log.h" #include "ircd_osdep.h" #include "ircd_reply.h" #include "ircd_string.h" #include "ircd_snprintf.h" #include "ircd.h" #include "numeric.h" #include "fileio.h" /* for fbopen / fbclose / fbputs */ #include "random.h" #include "s_bsd.h" #include "s_debug.h" #include "s_stats.h" #include "send.h" #include "sys.h" #include "res.h" #include "ircd_reslib.h" /* #include -- Now using assert in ircd_log.h */ #include #include #include #include #if (CHAR_BIT != 8) #error this code needs to be able to address individual octets #endif /** IPv4 resolver UDP socket. */ static struct Socket res_socket_v4; /** IPv6 resolver UDP socket. */ static struct Socket res_socket_v6; /** Next DNS lookup timeout. */ static struct Timer res_timeout; /** Local address for IPv4 DNS lookups. */ struct irc_sockaddr VirtualHost_dns_v4; /** Local address for IPv6 DNS lookups. */ struct irc_sockaddr VirtualHost_dns_v6; /** Check for whether the resolver has been initialized yet. */ #define resolver_started() (request_list.next != NULL) /** Maximum DNS packet length. * RFC says 512, but we add extra for expanded names. */ #define MAXPACKET 1024 #define AR_TTL 600 /**< TTL in seconds for dns cache entries */ /* RFC 1104/1105 wasn't very helpful about what these fields * should be named, so for now, we'll just name them this way. * we probably should look at what named calls them or something. */ /** Size of TYPE field of a DNS RR header. */ #define TYPE_SIZE (size_t)2 /** Size of CLASS field of a DNS RR header. */ #define CLASS_SIZE (size_t)2 /** Size of TTL field of a DNS RR header. */ #define TTL_SIZE (size_t)4 /** Size of RDLENGTH field of a DNS RR header. */ #define RDLENGTH_SIZE (size_t)2 /** Size of fixed-format part of a DNS RR header. */ #define ANSWER_FIXED_SIZE (TYPE_SIZE + CLASS_SIZE + TTL_SIZE + RDLENGTH_SIZE) /** Current request state. */ typedef enum { REQ_IDLE, /**< We're doing not much at all. */ REQ_PTR, /**< Looking up a PTR. */ REQ_A, /**< Looking up an A, possibly because AAAA failed. */ REQ_AAAA, /**< Looking up an AAAA. */ REQ_CNAME, /**< We got a CNAME in response, we better get a real answer next. */ REQ_INT /**< ip6.arpa failed, falling back to ip6.int. */ } request_state; /** Doubly linked list node. */ struct dlink { struct dlink *prev; /**< Previous element in list. */ struct dlink *next; /**< Next element in list. */ }; /** A single resolver request. * (Do not be fooled by the "list" in the name.) */ struct reslist { struct dlink node; /**< Doubly linked list node. */ int id; /**< Request ID (from request header). */ int sent; /**< Number of requests sent. */ request_state state; /**< State the resolver machine is in. */ char type; /**< Current request type. */ char retries; /**< Retry counter. */ char sends; /**< Number of sends (>1 means resent). */ char resend; /**< Send flag; 0 == don't resend. */ time_t sentat; /**< Timestamp we last sent this request. */ time_t timeout; /**< When this request times out. */ struct irc_in_addr addr; /**< Address for this request. */ char *name; /**< Hostname for this request. */ dns_callback_f callback; /**< Callback function on completion. */ void *callback_ctx; /**< Context pointer for callback. */ }; /** Base of request list. */ static struct dlink request_list; static void rem_request(struct reslist *request); static struct reslist *make_request(dns_callback_f callback, void *ctx); static void do_query_name(dns_callback_f callback, void *ctx, const char* name, struct reslist *request, int); static void do_query_number(dns_callback_f callback, void *ctx, const struct irc_in_addr *, struct reslist *request); static void query_name(const char *name, int query_class, int query_type, struct reslist *request); static int send_res_msg(const char *buf, int len, int count); static void resend_query(struct reslist *request); static int proc_answer(struct reslist *request, HEADER *header, char *, char *); static struct reslist *find_id(int id); static void res_readreply(struct Event *ev); static void timeout_resolver(struct Event *notused); extern struct irc_sockaddr irc_nsaddr_list[IRCD_MAXNS]; extern int irc_nscount; extern char irc_domain[HOSTLEN]; /** Prepare the resolver library to (optionally) accept a list of * DNS servers through add_dns_server(). */ void clear_nameservers(void) { irc_nscount = 0; memset(&VirtualHost_dns_v4, 0, sizeof(VirtualHost_dns_v4)); memset(&VirtualHost_dns_v6, 0, sizeof(VirtualHost_dns_v6)); } /** Check whether \a inp is a nameserver we use. * @param[in] inp Nameserver address. * @return Non-zero if we trust \a inp; zero if not. */ static int res_ourserver(const struct irc_sockaddr *inp) { int ns; for (ns = 0; ns < irc_nscount; ns++) if (!irc_in_addr_cmp(&inp->addr, &irc_nsaddr_list[ns].addr) && inp->port == irc_nsaddr_list[ns].port) return 1; return(0); } /** Start (or re-start) resolver. * This means read resolv.conf, initialize the list of pending * requests, open the resolver socket and initialize its timeout. */ void restart_resolver(void) { int need_v4; int need_v6; int ns; irc_res_init(); if (!request_list.next) request_list.next = request_list.prev = &request_list; /* Check which address family (or families) our nameservers use. */ for (need_v4 = need_v6 = ns = 0; ns < irc_nscount; ns++) { if (irc_in_addr_is_ipv4(&irc_nsaddr_list[ns].addr)) need_v4 = 1; else need_v6 = 1; } /* If we need an IPv4 socket, and don't have one, open it. */ if (need_v4 && !s_active(&res_socket_v4)) { int fd = os_socket(&VirtualHost_dns_v4, SOCK_DGRAM, "Resolver UDPv4 socket", AF_INET); if (fd >= 0) socket_add(&res_socket_v4, res_readreply, NULL, SS_DATAGRAM, SOCK_EVENT_READABLE, fd); } #ifdef AF_INET6 /* If we need an IPv6 socket, and don't have one, open it. */ if (need_v6 && !s_active(&res_socket_v6)) { int fd = os_socket(&VirtualHost_dns_v6, SOCK_DGRAM, "Resolver UDPv6 socket", AF_INET6); if (fd >= 0) socket_add(&res_socket_v6, res_readreply, NULL, SS_DATAGRAM, SOCK_EVENT_READABLE, fd); } #endif if (s_active(&res_socket_v4) || s_active(&res_socket_v6)) timer_init(&res_timeout); } /** Append local domain to hostname if needed. * If \a hname does not contain any '.'s, append #irc_domain to it. * @param[in,out] hname Hostname to check. * @param[in] size Length of \a hname buffer. */ void add_local_domain(char* hname, size_t size) { /* try to fix up unqualified names */ if (strchr(hname, '.') == NULL) { if (irc_domain[0]) { size_t len = strlen(hname); if ((strlen(irc_domain) + len + 2) < size) { hname[len++] = '.'; strcpy(hname + len, irc_domain); } } } } /** Add a node to a doubly linked list. * @param[in,out] node Node to add to list. * @param[in,out] next Add \a node before this one. */ static void add_dlink(struct dlink *node, struct dlink *next) { node->prev = next->prev; node->next = next; node->prev->next = node; node->next->prev = node; } /** Remove a request from the list and free it. * @param[in] request Node to free. */ static void rem_request(struct reslist *request) { /* remove from dlist */ request->node.prev->next = request->node.next; request->node.next->prev = request->node.prev; /* free memory */ MyFree(request->name); MyFree(request); } /** Create a DNS request record for the server. * @param[in] query Callback information for caller. * @return Newly allocated and linked-in reslist. */ static struct reslist * make_request(dns_callback_f callback, void *ctx) { struct reslist *request; if (!resolver_started()) restart_resolver(); request = (struct reslist *)MyMalloc(sizeof(struct reslist)); memset(request, 0, sizeof(struct reslist)); request->state = REQ_IDLE; request->sentat = CurrentTime; request->retries = feature_int(FEAT_IRCD_RES_RETRIES); request->resend = 1; request->timeout = feature_int(FEAT_IRCD_RES_TIMEOUT); memset(&request->addr, 0, sizeof(request->addr)); request->callback = callback; request->callback_ctx = ctx; add_dlink(&request->node, &request_list); return(request); } /** Make sure that a timeout event will happen by the given time. * @param[in] when Latest time for timeout to run. */ static void check_resolver_timeout(time_t when) { if (when > CurrentTime + AR_TTL) when = CurrentTime + AR_TTL; /* TODO after 2.10.12: Rewrite the timer API because there should be * no need for clients to know this kind of implementation detail. */ if (when > t_expire(&res_timeout)) /* do nothing */; else if (t_onqueue(&res_timeout) && !(res_timeout.t_header.gh_flags & GEN_MARKED)) timer_chg(&res_timeout, TT_ABSOLUTE, when); else timer_add(&res_timeout, timeout_resolver, NULL, TT_ABSOLUTE, when); } /** Drop pending DNS lookups which have timed out. * @param[in] ev Timer event data (ignored). */ static void timeout_resolver(struct Event *ev) { struct dlink *ptr, *next_ptr; struct reslist *request; time_t next_time = 0; time_t timeout = 0; if (ev_type(ev) != ET_EXPIRE) return; for (ptr = request_list.next; ptr != &request_list; ptr = next_ptr) { next_ptr = ptr->next; request = (struct reslist*)ptr; timeout = request->sentat + request->timeout; if (CurrentTime >= timeout) { if (--request->retries <= 0) { Debug((DEBUG_DNS, "Request %p out of retries; destroying", request)); (*request->callback)(request->callback_ctx, NULL, NULL); rem_request(request); continue; } else { request->sentat = CurrentTime; request->timeout += request->timeout; resend_query(request); } } if ((next_time == 0) || timeout < next_time) { next_time = timeout; } } if (next_time <= CurrentTime) next_time = CurrentTime + AR_TTL; check_resolver_timeout(next_time); } /** Drop queries that are associated with a particular pointer. * This is used to clean up lookups for clients or conf blocks * that went away. * @param[in] vptr User callback pointer to search for. */ void delete_resolver_queries(const void *vptr) { struct dlink *ptr, *next_ptr; struct reslist *request; if (request_list.next) { for (ptr = request_list.next; ptr != &request_list; ptr = next_ptr) { next_ptr = ptr->next; request = (struct reslist*)ptr; if (vptr == request->callback_ctx) { Debug((DEBUG_DNS, "Removing request %p with vptr %p", request, vptr)); rem_request(request); } } } } /** Send a message to all of our nameservers. * @param[in] msg Message to send. * @param[in] len Length of message. * @param[in] rcount Maximum number of servers to ask. * @return Number of servers that were successfully asked. */ static int send_res_msg(const char *msg, int len, int rcount) { int i; int sent = 0; int max_queries = IRCD_MIN(irc_nscount, rcount); /* RES_PRIMARY option is not implemented * if (res.options & RES_PRIMARY || 0 == max_queries) */ if (max_queries == 0) max_queries = 1; for (i = 0; i < max_queries; i++) { int fd = irc_in_addr_is_ipv4(&irc_nsaddr_list[i].addr) ? s_fd(&res_socket_v4) : s_fd(&res_socket_v6); if (os_sendto_nonb(fd, msg, len, NULL, 0, &irc_nsaddr_list[i]) == IO_SUCCESS) ++sent; } return(sent); } /** Find a DNS request by ID. * @param[in] id Identifier to find. * @return Matching DNS request, or NULL if none are found. */ static struct reslist * find_id(int id) { struct dlink *ptr; struct reslist *request; for (ptr = request_list.next; ptr != &request_list; ptr = ptr->next) { request = (struct reslist*)ptr; if (request->id == id) { Debug((DEBUG_DNS, "find_id(%d) -> %p", id, request)); return(request); } } Debug((DEBUG_DNS, "find_id(%d) -> NULL", id)); return(NULL); } /** Try to look up address for a hostname, trying IPv6 (T_AAAA) first. * @param[in] name Hostname to look up. * @param[in] query Callback information. */ void gethost_byname(const char *name, dns_callback_f callback, void *ctx) { do_query_name(callback, ctx, name, NULL, T_AAAA); } /** Try to look up hostname for an address. * @param[in] addr Address to look up. * @param[in] query Callback information. */ void gethost_byaddr(const struct irc_in_addr *addr, dns_callback_f callback, void *ctx) { do_query_number(callback, ctx, addr, NULL); } /** Send a query to look up the address for a name. * @param[in] query Callback information. * @param[in] name Hostname to look up. * @param[in] request DNS lookup structure (may be NULL). * @param[in] type Preferred request type. */ static void do_query_name(dns_callback_f callback, void *ctx, const char *name, struct reslist *request, int type) { char host_name[HOSTLEN + 1]; ircd_strncpy(host_name, name, HOSTLEN + 1); add_local_domain(host_name, HOSTLEN); if (request == NULL) { request = make_request(callback, ctx); DupString(request->name, host_name); #ifdef IPV6 if (type != T_A) request->state = REQ_AAAA; else #endif request->state = REQ_A; } request->type = type; Debug((DEBUG_DNS, "Requesting DNS %s %s as %p", (request->state == REQ_AAAA ? "AAAA" : "A"), host_name, request)); query_name(host_name, C_IN, type, request); } /** Send a query to look up the name for an address. * @param[in] query Callback information. * @param[in] addr Address to look up. * @param[in] request DNS lookup structure (may be NULL). */ static void do_query_number(dns_callback_f callback, void *ctx, const struct irc_in_addr *addr, struct reslist *request) { char ipbuf[128]; const unsigned char *cp; if (irc_in_addr_is_ipv4(addr)) { cp = (const unsigned char*)&addr->in6_16[6]; ircd_snprintf(NULL, ipbuf, sizeof(ipbuf), "%u.%u.%u.%u.in-addr.arpa.", (unsigned int)(cp[3]), (unsigned int)(cp[2]), (unsigned int)(cp[1]), (unsigned int)(cp[0])); } else { const char *intarpa; if (request != NULL && request->state == REQ_INT) intarpa = "int"; else intarpa = "arpa"; cp = (const unsigned char *)&addr->in6_16[0]; ircd_snprintf(NULL, ipbuf, sizeof(ipbuf), "%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x." "%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.ip6.%s.", (unsigned int)(cp[15]&0xf), (unsigned int)(cp[15]>>4), (unsigned int)(cp[14]&0xf), (unsigned int)(cp[14]>>4), (unsigned int)(cp[13]&0xf), (unsigned int)(cp[13]>>4), (unsigned int)(cp[12]&0xf), (unsigned int)(cp[12]>>4), (unsigned int)(cp[11]&0xf), (unsigned int)(cp[11]>>4), (unsigned int)(cp[10]&0xf), (unsigned int)(cp[10]>>4), (unsigned int)(cp[9]&0xf), (unsigned int)(cp[9]>>4), (unsigned int)(cp[8]&0xf), (unsigned int)(cp[8]>>4), (unsigned int)(cp[7]&0xf), (unsigned int)(cp[7]>>4), (unsigned int)(cp[6]&0xf), (unsigned int)(cp[6]>>4), (unsigned int)(cp[5]&0xf), (unsigned int)(cp[5]>>4), (unsigned int)(cp[4]&0xf), (unsigned int)(cp[4]>>4), (unsigned int)(cp[3]&0xf), (unsigned int)(cp[3]>>4), (unsigned int)(cp[2]&0xf), (unsigned int)(cp[2]>>4), (unsigned int)(cp[1]&0xf), (unsigned int)(cp[1]>>4), (unsigned int)(cp[0]&0xf), (unsigned int)(cp[0]>>4), intarpa); } if (request == NULL) { request = make_request(callback, ctx); request->state= REQ_PTR; request->type = T_PTR; memcpy(&request->addr, addr, sizeof(request->addr)); request->name = (char *)MyMalloc(HOSTLEN + 1); } Debug((DEBUG_DNS, "Requesting DNS PTR %s as %p", ipbuf, request)); query_name(ipbuf, C_IN, T_PTR, request); } /** Generate a query based on class, type and name. * @param[in] name Domain name to look up. * @param[in] query_class Query class (see RFC 1035). * @param[in] type Query type (see RFC 1035). * @param[in] request DNS request structure. */ static void query_name(const char *name, int query_class, int type, struct reslist *request) { char buf[MAXPACKET]; int request_len = 0; memset(buf, 0, sizeof(buf)); if ((request_len = irc_res_mkquery(name, query_class, type, (unsigned char *)buf, sizeof(buf))) > 0) { HEADER *header = (HEADER *)buf; /* * generate an unique id * NOTE: we don't have to worry about converting this to and from * network byte order, the nameserver does not interpret this value * and returns it unchanged */ do { header->id = (header->id + ircrandom()) & 0xffff; } while (find_id(header->id)); request->id = header->id; ++request->sends; request->sent += send_res_msg(buf, request_len, request->sends); check_resolver_timeout(request->sentat + request->timeout); } } /** Send a failed DNS lookup request again. * @param[in] request Request to resend. */ static void resend_query(struct reslist *request) { if (request->resend == 0) return; switch(request->type) { case T_PTR: do_query_number(NULL, NULL, &request->addr, request); break; case T_A: do_query_name(NULL, NULL, request->name, request, request->type); break; case T_AAAA: /* didn't work, try A */ if (request->state == REQ_AAAA) do_query_name(NULL, NULL, request->name, request, T_A); default: break; } } /** Process the answer for a lookup request. * @param[in] request DNS request that got an answer. * @param[in] header Header of DNS response. * @param[in] buf DNS response body. * @param[in] eob Pointer to end of DNS response. * @return Number of answers read from \a buf. */ static int proc_answer(struct reslist *request, HEADER* header, char* buf, char* eob) { char hostbuf[HOSTLEN + 100]; /* working buffer */ unsigned char *current; /* current position in buf */ int type; /* answer type */ int n; /* temp count */ int rd_length; current = (unsigned char *)buf + sizeof(HEADER); for (; header->qdcount > 0; --header->qdcount) { if ((n = irc_dn_skipname(current, (unsigned char *)eob)) < 0) break; current += (size_t) n + QFIXEDSZ; } /* * process each answer sent to us blech. */ while (header->ancount > 0 && (char *)current < eob) { header->ancount--; n = irc_dn_expand((unsigned char *)buf, (unsigned char *)eob, current, hostbuf, sizeof(hostbuf)); if (n < 0) { /* * broken message */ return(0); } else if (n == 0) { /* * no more answers left */ return(0); } hostbuf[HOSTLEN] = '\0'; /* With Address arithmetic you have to be very anal * this code was not working on alpha due to that * (spotted by rodder/jailbird/dianora) */ current += (size_t) n; if (!(((char *)current + ANSWER_FIXED_SIZE) < eob)) break; type = irc_ns_get16(current); current += TYPE_SIZE; /* We do not use the class or TTL values. */ current += CLASS_SIZE; current += TTL_SIZE; rd_length = irc_ns_get16(current); current += RDLENGTH_SIZE; /* * Wait to set request->type until we verify this structure */ switch (type) { case T_A: if (request->type != T_A) return(0); /* * check for invalid rd_length or too many addresses */ if (rd_length != sizeof(struct in_addr)) return(0); memset(&request->addr, 0, sizeof(request->addr)); memcpy(&request->addr.in6_16[6], current, sizeof(struct in_addr)); return(1); break; case T_AAAA: if (request->type != T_AAAA) return(0); if (rd_length != sizeof(struct irc_in_addr)) return(0); memcpy(&request->addr, current, sizeof(struct irc_in_addr)); return(1); break; case T_PTR: if (request->type != T_PTR) return(0); n = irc_dn_expand((unsigned char *)buf, (unsigned char *)eob, current, hostbuf, sizeof(hostbuf)); if (n < 0) return(0); /* broken message */ else if (n == 0) return(0); /* no more answers left */ ircd_strncpy(request->name, hostbuf, HOSTLEN + 1); return(1); break; case T_CNAME: /* first check we already haven't started looking into a cname */ if (request->state == REQ_CNAME) { n = irc_dn_expand((unsigned char *)buf, (unsigned char *)eob, current, hostbuf, sizeof(hostbuf)); if (n < 0) return(0); return(1); } request->state = REQ_CNAME; current += rd_length; break; default: /* XXX I'd rather just throw away the entire bogus thing * but its possible its just a broken nameserver with still * valid answers. But lets do some rudimentary logging for now... */ log_write(LS_RESOLVER, L_ERROR, 0, "irc_res.c bogus type %d", type); if ((char*)current + rd_length >= (char*)current) current += rd_length; else return(0); break; } } return(1); } /** Read a DNS reply from the nameserver and process it. * @param[in] ev I/O activity event for resolver socket. */ static void res_readreply(struct Event *ev) { struct irc_sockaddr lsin; struct Socket *sock; char buf[sizeof(HEADER) + MAXPACKET]; HEADER *header; struct reslist *request = NULL; unsigned int rc; int answer_count; assert((ev_socket(ev) == &res_socket_v4) || (ev_socket(ev) == &res_socket_v6)); sock = ev_socket(ev); if (IO_SUCCESS != os_recvfrom_nonb(s_fd(sock), buf, sizeof(buf), &rc, &lsin) || (rc <= sizeof(HEADER))) return; /* * check against possibly fake replies */ if (!res_ourserver(&lsin)) return; /* * convert DNS reply reader from Network byte order to CPU byte order. */ header = (HEADER *)buf; header->ancount = ntohs(header->ancount); header->qdcount = ntohs(header->qdcount); header->nscount = ntohs(header->nscount); header->arcount = ntohs(header->arcount); /* * response for an id which we have already received an answer for * just ignore this response. */ if (0 == (request = find_id(header->id))) return; if ((header->rcode != NO_ERRORS) || (header->ancount == 0)) { if (SERVFAIL == header->rcode || NXDOMAIN == header->rcode) { /* * If a bad error was returned, we stop here and don't send * send any more (no retries granted). */ Debug((DEBUG_DNS, "Request %p has bad response (state %d type %d rcode %d)", request, request->state, request->type, header->rcode)); (*request->callback)(request->callback_ctx, NULL, NULL); rem_request(request); } else { /* * If we haven't already tried this, and we're looking up AAAA, try A * now */ if (request->state == REQ_AAAA && request->type == T_AAAA) { request->timeout += feature_int(FEAT_IRCD_RES_TIMEOUT); resend_query(request); } else if (request->type == T_PTR && request->state != REQ_INT && !irc_in_addr_is_ipv4(&request->addr)) { request->state = REQ_INT; request->timeout += feature_int(FEAT_IRCD_RES_TIMEOUT); resend_query(request); } } return; } /* * If this fails there was an error decoding the received packet, * try it again and hope it works the next time. */ answer_count = proc_answer(request, header, buf, buf + rc); if (answer_count) { if (request->type == T_PTR) { if (request->name == NULL) { /* * got a PTR response with no name, something bogus is happening * don't bother trying again, the client address doesn't resolve */ Debug((DEBUG_DNS, "Request %p PTR had empty name", request)); (*request->callback)(request->callback_ctx, NULL, NULL); rem_request(request); return; } /* * Lookup the 'authoritative' name that we were given for the * ip#. */ #ifdef IPV6 if (!irc_in_addr_is_ipv4(&request->addr)) do_query_name(request->callback, request->callback_ctx, request->name, NULL, T_AAAA); else #endif do_query_name(request->callback, request->callback_ctx, request->name, NULL, T_A); Debug((DEBUG_DNS, "Request %p switching to forward resolution", request)); rem_request(request); } else { /* * got a name and address response, client resolved */ (*request->callback)(request->callback_ctx, &request->addr, request->name); Debug((DEBUG_DNS, "Request %p got forward resolution", request)); rem_request(request); } } else if (!request->sent) { /* XXX - we got a response for a query we didn't send with a valid id? * this should never happen, bail here and leave the client unresolved */ assert(0); /* XXX don't leak it */ Debug((DEBUG_DNS, "Request %p was unexpected(!)", request)); rem_request(request); } } /** Statistics callback to list DNS servers. * @param[in] source_p Client requesting statistics. * @param[in] sd Stats descriptor for request (ignored). * @param[in] param Extra parameter from user (ignored). */ void report_dns_servers(struct Client *source_p, const struct StatDesc *sd, char *param) { int i; char ipaddr[128]; for (i = 0; i < irc_nscount; i++) { ircd_ntoa_r(ipaddr, &irc_nsaddr_list[i].addr); send_reply(source_p, RPL_STATSALINE, ipaddr); } } /** Report memory usage to a client. * @param[in] sptr Client requesting information. * @return Total memory used by pending requests. */ size_t cres_mem(struct Client* sptr) { struct dlink *dlink; struct reslist *request; size_t request_mem = 0; int request_count = 0; if (request_list.next) { for (dlink = request_list.next; dlink != &request_list; dlink = dlink->next) { request = (struct reslist*)dlink; request_mem += sizeof(*request); if (request->name) request_mem += strlen(request->name) + 1; ++request_count; } } send_reply(sptr, SND_EXPLICIT | RPL_STATSDEBUG, ":Resolver: requests %d(%d)", request_count, request_mem); return request_mem; }