/* * ircd-ratbox: A slightly useful ircd. * s_auth.c: Functions for querying a users ident. * * Copyright (C) 1990 Jarkko Oikarinen and University of Oulu, Co Center * Copyright (C) 1996-2002 Hybrid Development Team * Copyright (C) 2002-2005 ircd-ratbox development team * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 * USA * * $Id: s_auth.c 3161 2007-01-25 07:23:01Z nenolod $ */ /* * Changes: * July 6, 1999 - Rewrote most of the code here. When a client connects * to the server and passes initial socket validation checks, it * is owned by this module (auth) which returns it to the rest of the * server when dns and auth queries are finished. Until the client is * released, the server does not know it exists and does not process * any messages from it. * --Bleep Thomas Helvey */ #include "stdinc.h" #include "config.h" #include "tools.h" #include "s_auth.h" #include "s_conf.h" #include "client.h" #include "common.h" #include "event.h" #include "irc_string.h" #include "sprintf_irc.h" #include "ircd.h" #include "numeric.h" #include "packet.h" #include "res.h" #include "commio.h" #include "s_log.h" #include "s_stats.h" #include "send.h" #include "memory.h" #include "hook.h" #include "blacklist.h" /* * a bit different approach * this replaces the original sendheader macros */ static const char *HeaderMessages[] = { ":*** Looking up your hostname...", ":*** Found your hostname", ":*** Couldn't look up your hostname", ":*** Checking Ident", ":*** Got Ident response", ":*** No Ident response", ":*** Your hostname is too long, ignoring hostname", ":*** Your forward and reverse DNS do not match, ignoring hostname", ":*** Cannot verify hostname validity, ignoring hostname", }; typedef enum { REPORT_DO_DNS, REPORT_FIN_DNS, REPORT_FAIL_DNS, REPORT_DO_ID, REPORT_FIN_ID, REPORT_FAIL_ID, REPORT_HOST_TOOLONG, REPORT_HOST_MISMATCH, REPORT_HOST_UNKNOWN } ReportType; #define sendheader(c, r) sendto_one_notice(c, HeaderMessages[(r)]) static dlink_list auth_poll_list; static BlockHeap *auth_heap; static EVH timeout_auth_queries_event; static PF read_auth_reply; static CNCB auth_connect_callback; /* * init_auth() * * Initialise the auth code */ void init_auth(void) { /* This hook takes a struct Client for its argument */ memset(&auth_poll_list, 0, sizeof(auth_poll_list)); eventAddIsh("timeout_auth_queries_event", timeout_auth_queries_event, NULL, 1); auth_heap = BlockHeapCreate(sizeof(struct AuthRequest), LCLIENT_HEAP_SIZE); } /* * make_auth_request - allocate a new auth request */ static struct AuthRequest * make_auth_request(struct Client *client) { struct AuthRequest *request = BlockHeapAlloc(auth_heap); client->localClient->auth_request = request; request->fd = -1; request->client = client; request->timeout = CurrentTime + ConfigFileEntry.connect_timeout; return request; } /* * free_auth_request - cleanup auth request allocations */ static void free_auth_request(struct AuthRequest *request) { BlockHeapFree(auth_heap, request); } /* * release_auth_client - release auth client from auth system * this adds the client into the local client lists so it can be read by * the main io processing loop */ static void release_auth_client(struct AuthRequest *auth) { struct Client *client = auth->client; if(IsDNSPending(auth) || IsDoingAuth(auth)) return; client->localClient->auth_request = NULL; dlinkDelete(&auth->node, &auth_poll_list); free_auth_request(auth); if(client->localClient->fd > highest_fd) highest_fd = client->localClient->fd; /* * When a client has auth'ed, we want to start reading what it sends * us. This is what read_packet() does. * -- adrian */ client->localClient->allow_read = MAX_FLOOD; comm_setflush(client->localClient->fd, 1000, flood_recalc, client); dlinkAddTail(client, &client->node, &global_client_list); read_packet(client->localClient->fd, client); } /* * auth_dns_callback - called when resolver query finishes * if the query resulted in a successful search, hp will contain * a non-null pointer, otherwise hp will be null. * set the client on it's way to a connection completion, regardless * of success of failure */ static void auth_dns_callback(void *vptr, struct DNSReply *reply) { struct AuthRequest *auth = (struct AuthRequest *) vptr; ClearDNSPending(auth); /* XXX: this shouldn't happen, but it does. -nenolod */ if(auth->client->localClient == NULL) { sendto_realops_snomask(SNO_GENERAL, L_ALL, "auth_dns_callback(): auth->client->localClient (%s) is NULL", get_client_name(auth->client, HIDE_IP)); dlinkDelete(&auth->node, &auth_poll_list); free_auth_request(auth); /* and they will silently drop through and all will hopefully be ok... -nenolod */ return; } if(reply) { int good = 1; if(auth->client->localClient->ip.ss_family == AF_INET) { struct sockaddr_in *ip, *ip_fwd; ip = (struct sockaddr_in *) &auth->client->localClient->ip; ip_fwd = (struct sockaddr_in *) &reply->addr; if(ip->sin_addr.s_addr != ip_fwd->sin_addr.s_addr) { sendheader(auth->client, REPORT_HOST_MISMATCH); good = 0; } } #ifdef IPV6 else if(auth->client->localClient->ip.ss_family == AF_INET6) { struct sockaddr_in6 *ip, *ip_fwd; ip = (struct sockaddr_in6 *) &auth->client->localClient->ip; ip_fwd = (struct sockaddr_in6 *) &reply->addr; if(memcmp(&ip->sin6_addr, &ip_fwd->sin6_addr, sizeof(struct in6_addr)) != 0) { sendheader(auth->client, REPORT_HOST_MISMATCH); good = 0; } } #endif else /* can't verify it, don't know how. reject it. */ { sendheader(auth->client, REPORT_HOST_UNKNOWN); good = 0; } if(good && strlen(reply->h_name) <= HOSTLEN) { strlcpy(auth->client->host, reply->h_name, sizeof(auth->client->host)); sendheader(auth->client, REPORT_FIN_DNS); } else if (strlen(reply->h_name) > HOSTLEN) sendheader(auth->client, REPORT_HOST_TOOLONG); } else sendheader(auth->client, REPORT_FAIL_DNS); release_auth_client(auth); } /* * authsenderr - handle auth send errors */ static void auth_error(struct AuthRequest *auth) { ++ServerStats->is_abad; comm_close(auth->fd); auth->fd = -1; ClearAuth(auth); sendheader(auth->client, REPORT_FAIL_ID); release_auth_client(auth); } /* * start_auth_query - Flag the client to show that an attempt to * contact the ident server on * the client's host. The connect and subsequently the socket are all put * into 'non-blocking' mode. Should the connect or any later phase of the * identifing process fail, it is aborted and the user is given a username * of "unknown". */ static int start_auth_query(struct AuthRequest *auth) { struct irc_sockaddr_storage localaddr; socklen_t locallen = sizeof(struct irc_sockaddr_storage); int fd; int family; if(IsAnyDead(auth->client)) return 0; family = auth->client->localClient->ip.ss_family; if((fd = comm_socket(family, SOCK_STREAM, 0, "ident")) == -1) { report_error("creating auth stream socket %s:%s", get_client_name(auth->client, SHOW_IP), log_client_name(auth->client, SHOW_IP), errno); ++ServerStats->is_abad; return 0; } if((MAXCONNECTIONS - 10) < fd) { sendto_realops_snomask(SNO_GENERAL, L_ALL, "Can't allocate fd for auth on %s", get_client_name(auth->client, SHOW_IP)); comm_close(fd); return 0; } sendheader(auth->client, REPORT_DO_ID); /* * get the local address of the client and bind to that to * make the auth request. This used to be done only for * ifdef VIRTUAL_HOST, but needs to be done for all clients * since the ident request must originate from that same address-- * and machines with multiple IP addresses are common now */ memset(&localaddr, 0, locallen); getsockname(auth->client->localClient->fd, (struct sockaddr *) &localaddr, &locallen); mangle_mapped_sockaddr((struct sockaddr *)&localaddr); #ifdef IPV6 if(localaddr.ss_family == AF_INET6) { ((struct sockaddr_in6 *)&localaddr)->sin6_port = 0; } else #endif ((struct sockaddr_in *)&localaddr)->sin_port = 0; auth->fd = fd; SetAuthConnect(auth); comm_connect_tcp(fd, auth->client->sockhost, 113, (struct sockaddr *) &localaddr, GET_SS_LEN(localaddr), auth_connect_callback, auth, localaddr.ss_family, GlobalSetOptions.ident_timeout); return 1; /* We suceed here for now */ } /* * GetValidIdent - parse ident query reply from identd server * * Inputs - pointer to ident buf * Output - NULL if no valid ident found, otherwise pointer to name * Side effects - */ static char * GetValidIdent(char *buf) { int remp = 0; int locp = 0; char *colon1Ptr; char *colon2Ptr; char *colon3Ptr; char *commaPtr; char *remotePortString; /* All this to get rid of a sscanf() fun. */ remotePortString = buf; colon1Ptr = strchr(remotePortString, ':'); if(!colon1Ptr) return 0; *colon1Ptr = '\0'; colon1Ptr++; colon2Ptr = strchr(colon1Ptr, ':'); if(!colon2Ptr) return 0; *colon2Ptr = '\0'; colon2Ptr++; commaPtr = strchr(remotePortString, ','); if(!commaPtr) return 0; *commaPtr = '\0'; commaPtr++; remp = atoi(remotePortString); if(!remp) return 0; locp = atoi(commaPtr); if(!locp) return 0; /* look for USERID bordered by first pair of colons */ if(!strstr(colon1Ptr, "USERID")) return 0; colon3Ptr = strchr(colon2Ptr, ':'); if(!colon3Ptr) return 0; *colon3Ptr = '\0'; colon3Ptr++; return (colon3Ptr); } /* * start_auth - starts auth (identd) and dns queries for a client */ void start_auth(struct Client *client) { struct AuthRequest *auth = 0; s_assert(0 != client); if(client == NULL) return; auth = make_auth_request(client); auth->dns_query.ptr = auth; auth->dns_query.callback = auth_dns_callback; sendheader(client, REPORT_DO_DNS); /* No DNS cache now, remember? -- adrian */ gethost_byaddr(&client->localClient->ip, &auth->dns_query); SetDNSPending(auth); if(ConfigFileEntry.disable_auth == 0) start_auth_query(auth); dlinkAdd(auth, &auth->node, &auth_poll_list); } /* * timeout_auth_queries - timeout resolver and identd requests * allow clients through if requests failed */ static void timeout_auth_queries_event(void *notused) { dlink_node *ptr; dlink_node *next_ptr; struct AuthRequest *auth; DLINK_FOREACH_SAFE(ptr, next_ptr, auth_poll_list.head) { auth = ptr->data; if(auth->timeout < CurrentTime) { if(auth->fd >= 0) comm_close(auth->fd); if(IsDoingAuth(auth)) { ClearAuth(auth); ++ServerStats->is_abad; sendheader(auth->client, REPORT_FAIL_ID); auth->client->localClient->auth_request = NULL; } if(IsDNSPending(auth)) { ClearDNSPending(auth); delete_resolver_queries(&auth->dns_query); sendheader(auth->client, REPORT_FAIL_DNS); } auth->client->localClient->lasttime = CurrentTime; release_auth_client(auth); } } } /* * auth_connect_callback() - deal with the result of comm_connect_tcp() * * If the connection failed, we simply close the auth fd and report * a failure. If the connection suceeded send the ident server a query * giving "theirport , ourport". The write is only attempted *once* so * it is deemed to be a fail if the entire write doesn't write all the * data given. This shouldnt be a problem since the socket should have * a write buffer far greater than this message to store it in should * problems arise. -avalon */ static void auth_connect_callback(int fd, int error, void *data) { struct AuthRequest *auth = data; struct sockaddr_in us; struct sockaddr_in them; char authbuf[32]; socklen_t ulen = sizeof(struct sockaddr_in); socklen_t tlen = sizeof(struct sockaddr_in); /* Check the error */ if(error != COMM_OK) { /* We had an error during connection :( */ auth_error(auth); return; } if(getsockname (auth->client->localClient->fd, (struct sockaddr *) &us, (socklen_t *) & ulen) || getpeername(auth->client->localClient->fd, (struct sockaddr *) &them, (socklen_t *) & tlen)) { ilog(L_IOERROR, "auth get{sock,peer}name error for %s:%m", log_client_name(auth->client, SHOW_IP)); auth_error(auth); return; } ircsnprintf(authbuf, sizeof(authbuf), "%u , %u\r\n", (unsigned int) ntohs(them.sin_port), (unsigned int) ntohs(us.sin_port)); if(write(auth->fd, authbuf, strlen(authbuf)) == -1) { auth_error(auth); return; } ClearAuthConnect(auth); SetAuthPending(auth); read_auth_reply(auth->fd, auth); } /* * read_auth_reply - read the reply (if any) from the ident server * we connected to. * We only give it one shot, if the reply isn't good the first time * fail the authentication entirely. --Bleep */ #define AUTH_BUFSIZ 128 static void read_auth_reply(int fd, void *data) { struct AuthRequest *auth = data; char *s = NULL; char *t = NULL; int len; int count; char buf[AUTH_BUFSIZ + 1]; /* buffer to read auth reply into */ len = read(auth->fd, buf, AUTH_BUFSIZ); if(len < 0 && ignoreErrno(errno)) { comm_setselect(fd, FDLIST_IDLECLIENT, COMM_SELECT_READ, read_auth_reply, auth, 0); return; } if(len > 0) { buf[len] = '\0'; if((s = GetValidIdent(buf))) { t = auth->client->username; while (*s == '~' || *s == '^') s++; for (count = USERLEN; *s && count; s++) { if(*s == '@') { break; } if(!IsSpace(*s) && *s != ':' && *s != '[') { *t++ = *s; count--; } } *t = '\0'; } } comm_close(auth->fd); auth->fd = -1; ClearAuth(auth); if(s == NULL) { ++ServerStats->is_abad; strcpy(auth->client->username, "unknown"); sendheader(auth->client, REPORT_FAIL_ID); } else { sendheader(auth->client, REPORT_FIN_ID); ++ServerStats->is_asuc; SetGotId(auth->client); } release_auth_client(auth); } /* * delete_auth_queries() * */ void delete_auth_queries(struct Client *target_p) { struct AuthRequest *auth; if(target_p == NULL || target_p->localClient == NULL || target_p->localClient->auth_request == NULL) return; auth = target_p->localClient->auth_request; target_p->localClient->auth_request = NULL; if(IsDNSPending(auth)) delete_resolver_queries(&auth->dns_query); if(auth->fd >= 0) comm_close(auth->fd); dlinkDelete(&auth->node, &auth_poll_list); free_auth_request(auth); }