diff options
Diffstat (limited to 'source3/nmbd/nmbd_incomingrequests.c')
| -rw-r--r-- | source3/nmbd/nmbd_incomingrequests.c | 590 |
1 files changed, 590 insertions, 0 deletions
diff --git a/source3/nmbd/nmbd_incomingrequests.c b/source3/nmbd/nmbd_incomingrequests.c new file mode 100644 index 0000000..06c486d --- /dev/null +++ b/source3/nmbd/nmbd_incomingrequests.c @@ -0,0 +1,590 @@ +/* + Unix SMB/CIFS implementation. + NBT netbios routines and daemon - version 2 + Copyright (C) Andrew Tridgell 1994-1998 + Copyright (C) Luke Kenneth Casson Leighton 1994-1998 + Copyright (C) Jeremy Allison 1994-2003 + + 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/>. + + This file contains all the code to process NetBIOS requests coming + in on port 137. It does not deal with the code needed to service + WINS server requests, but only broadcast and unicast requests. + +*/ + +#include "includes.h" +#include "nmbd/nmbd.h" + +/**************************************************************************** +Send a name release response. +**************************************************************************/ + +static void send_name_release_response(int rcode, struct packet_struct *p) +{ + struct nmb_packet *nmb = &p->packet.nmb; + char rdata[6]; + + memcpy(&rdata[0], &nmb->additional->rdata[0], 6); + + reply_netbios_packet(p, /* Packet to reply to. */ + rcode, /* Result code. */ + NMB_REL, /* nmbd type code. */ + NMB_NAME_RELEASE_OPCODE, /* opcode. */ + 0, /* ttl. */ + rdata, /* data to send. */ + 6); /* data length. */ +} + +/**************************************************************************** +Process a name release packet on a broadcast subnet. +Ignore it if it's not one of our names. +****************************************************************************/ + +void process_name_release_request(struct subnet_record *subrec, + struct packet_struct *p) +{ + struct nmb_packet *nmb = &p->packet.nmb; + struct in_addr owner_ip; + struct nmb_name *question = &nmb->question.question_name; + unstring qname; + bool bcast = nmb->header.nm_flags.bcast; + uint16_t nb_flags = get_nb_flags(nmb->additional->rdata); + bool group = (nb_flags & NB_GROUP) ? True : False; + struct name_record *namerec; + int rcode = 0; + + putip((char *)&owner_ip,&nmb->additional->rdata[2]); + + if(!bcast) { + /* We should only get broadcast name release packets here. + Anyone trying to release unicast should be going to a WINS + server. If the code gets here, then either we are not a wins + server and they sent it anyway, or we are a WINS server and + the request was malformed. Either way, log an error here. + and send an error reply back. + */ + DEBUG(0,("process_name_release_request: unicast name release request \ +received for name %s from IP %s on subnet %s. Error - should be sent to WINS server\n", + nmb_namestr(question), inet_ntoa(owner_ip), subrec->subnet_name)); + + send_name_release_response(FMT_ERR, p); + return; + } + + DEBUG(3,("process_name_release_request: Name release on name %s, \ +subnet %s from owner IP %s\n", + nmb_namestr(&nmb->question.question_name), + subrec->subnet_name, inet_ntoa(owner_ip))); + + /* If someone is releasing a broadcast group name, just ignore it. */ + if( group && !ismyip_v4(owner_ip) ) + return; + + /* + * Code to work around a bug in FTP OnNet software NBT implementation. + * They do a broadcast name release for WORKGROUP<0> and WORKGROUP<1e> + * names and *don't set the group bit* !!!!! + */ + + pull_ascii_nstring(qname, sizeof(qname), question->name); + if( !group && !ismyip_v4(owner_ip) && strequal(qname, lp_workgroup()) && + ((question->name_type == 0x0) || (question->name_type == 0x1e))) { + DEBUG(6,("process_name_release_request: FTP OnNet bug workaround. Ignoring \ +group release name %s from IP %s on subnet %s with no group bit set.\n", + nmb_namestr(question), inet_ntoa(owner_ip), subrec->subnet_name )); + return; + } + + namerec = find_name_on_subnet(subrec, question, FIND_ANY_NAME); + + /* We only care about someone trying to release one of our names. */ + if( namerec && ( (namerec->data.source == SELF_NAME) + || (namerec->data.source == PERMANENT_NAME) ) ) { + rcode = ACT_ERR; + DEBUG(0, ("process_name_release_request: Attempt to release name %s from IP %s \ +on subnet %s being rejected as it is one of our names.\n", + nmb_namestr(&nmb->question.question_name), inet_ntoa(owner_ip), subrec->subnet_name)); + } + + if(rcode == 0) + return; + + /* Send a NAME RELEASE RESPONSE (pos/neg) see rfc1002.txt 4.2.10-11 */ + send_name_release_response(rcode, p); +} + +/**************************************************************************** +Send a name registration response. +**************************************************************************/ + +static void send_name_registration_response(int rcode, int ttl, struct packet_struct *p) +{ + struct nmb_packet *nmb = &p->packet.nmb; + char rdata[6]; + + memcpy(&rdata[0], &nmb->additional->rdata[0], 6); + + reply_netbios_packet(p, /* Packet to reply to. */ + rcode, /* Result code. */ + NMB_REG, /* nmbd type code. */ + NMB_NAME_REG_OPCODE, /* opcode. */ + ttl, /* ttl. */ + rdata, /* data to send. */ + 6); /* data length. */ +} + +/**************************************************************************** +Process a name refresh request on a broadcast subnet. +**************************************************************************/ + +void process_name_refresh_request(struct subnet_record *subrec, + struct packet_struct *p) +{ + struct nmb_packet *nmb = &p->packet.nmb; + struct nmb_name *question = &nmb->question.question_name; + bool bcast = nmb->header.nm_flags.bcast; + struct in_addr from_ip; + + putip((char *)&from_ip,&nmb->additional->rdata[2]); + + if(!bcast) { + /* We should only get broadcast name refresh packets here. + Anyone trying to refresh unicast should be going to a WINS + server. If the code gets here, then either we are not a wins + server and they sent it anyway, or we are a WINS server and + the request was malformed. Either way, log an error here. + and send an error reply back. + */ + DEBUG(0,("process_name_refresh_request: unicast name registration request \ +received for name %s from IP %s on subnet %s.\n", + nmb_namestr(question), inet_ntoa(from_ip), subrec->subnet_name)); + DEBUG(0,("Error - should be sent to WINS server\n")); + + send_name_registration_response(FMT_ERR, 0, p); + return; + } + + /* Just log a message. We really don't care about broadcast name refreshes. */ + + DEBUG(3,("process_name_refresh_request: Name refresh for name %s \ +IP %s on subnet %s\n", nmb_namestr(question), inet_ntoa(from_ip), subrec->subnet_name)); +} + +/**************************************************************************** +Process a name registration request on a broadcast subnet. +**************************************************************************/ + +void process_name_registration_request(struct subnet_record *subrec, + struct packet_struct *p) +{ + struct nmb_packet *nmb = &p->packet.nmb; + struct nmb_name *question = &nmb->question.question_name; + bool bcast = nmb->header.nm_flags.bcast; + uint16_t nb_flags = get_nb_flags(nmb->additional->rdata); + bool group = (nb_flags & NB_GROUP) ? True : False; + struct name_record *namerec = NULL; + int ttl = nmb->additional->ttl; + struct in_addr from_ip; + + putip((char *)&from_ip,&nmb->additional->rdata[2]); + + if(!bcast) { + /* We should only get broadcast name registration packets here. + Anyone trying to register unicast should be going to a WINS + server. If the code gets here, then either we are not a wins + server and they sent it anyway, or we are a WINS server and + the request was malformed. Either way, log an error here. + and send an error reply back. + */ + DEBUG(0,("process_name_registration_request: unicast name registration request \ +received for name %s from IP %s on subnet %s. Error - should be sent to WINS server\n", + nmb_namestr(question), inet_ntoa(from_ip), subrec->subnet_name)); + + send_name_registration_response(FMT_ERR, 0, p); + return; + } + + DEBUG(3,("process_name_registration_request: Name registration for name %s \ +IP %s on subnet %s\n", nmb_namestr(question), inet_ntoa(from_ip), subrec->subnet_name)); + + /* See if the name already exists. */ + namerec = find_name_on_subnet(subrec, question, FIND_ANY_NAME); + + /* + * If the name being registered exists and is a WINS_PROXY_NAME + * then delete the WINS proxy name entry so we don't reply erroneously + * later to queries. + */ + + if((namerec != NULL) && (namerec->data.source == WINS_PROXY_NAME)) { + remove_name_from_namelist( subrec, namerec ); + namerec = NULL; + } + + if (!group) { + /* Unique name. */ + + if( (namerec != NULL) + && ( (namerec->data.source == SELF_NAME) + || (namerec->data.source == PERMANENT_NAME) + || NAME_GROUP(namerec) ) ) { + /* No-one can register one of Samba's names, nor can they + register a name that's a group name as a unique name */ + + send_name_registration_response(ACT_ERR, 0, p); + return; + } else if(namerec != NULL) { + /* Update the namelist record with the new information. */ + namerec->data.ip[0] = from_ip; + update_name_ttl(namerec, ttl); + + DEBUG(3,("process_name_registration_request: Updated name record %s \ +with IP %s on subnet %s\n",nmb_namestr(&namerec->name),inet_ntoa(from_ip), subrec->subnet_name)); + return; + } + } else { + /* Group name. */ + + if( (namerec != NULL) + && !NAME_GROUP(namerec) + && ( (namerec->data.source == SELF_NAME) + || (namerec->data.source == PERMANENT_NAME) ) ) { + /* Disallow group names when we have a unique name. */ + send_name_registration_response(ACT_ERR, 0, p); + return; + } + } +} + +/**************************************************************************** +This is used to sort names for a name status into a sensible order. +We put our own names first, then in alphabetical order. +**************************************************************************/ + +static int status_compare(char *n1,char *n2) +{ + unstring name1, name2; + int l1,l2,l3; + + memset(name1, '\0', sizeof(name1)); + memset(name2, '\0', sizeof(name2)); + pull_ascii_nstring(name1, sizeof(name1), n1); + pull_ascii_nstring(name2, sizeof(name2), n2); + n1 = name1; + n2 = name2; + + /* It's a bit tricky because the names are space padded */ + for (l1=0;l1<15 && n1[l1] && n1[l1] != ' ';l1++) + ; + for (l2=0;l2<15 && n2[l2] && n2[l2] != ' ';l2++) + ; + l3 = strlen(lp_netbios_name()); + + if ((l1==l3) && strncmp(n1,lp_netbios_name(),l3) == 0 && + (l2!=l3 || strncmp(n2,lp_netbios_name(),l3) != 0)) + return -1; + + if ((l2==l3) && strncmp(n2,lp_netbios_name(),l3) == 0 && + (l1!=l3 || strncmp(n1,lp_netbios_name(),l3) != 0)) + return 1; + + return memcmp(n1,n2,sizeof(name1)); +} + +/**************************************************************************** + Process a node status query + ****************************************************************************/ + +void process_node_status_request(struct subnet_record *subrec, struct packet_struct *p) +{ + struct nmb_packet *nmb = &p->packet.nmb; + unstring qname; + int ques_type = nmb->question.question_name.name_type; + char rdata[MAX_DGRAM_SIZE]; + char *countptr, *buf, *bufend, *buf0; + int names_added,i; + struct name_record *namerec = NULL; + + pull_ascii_nstring(qname, sizeof(qname), nmb->question.question_name.name); + + DEBUG(3,("process_node_status_request: status request for name %s from IP %s on \ +subnet %s.\n", nmb_namestr(&nmb->question.question_name), inet_ntoa(p->ip), subrec->subnet_name)); + + if(find_name_on_subnet(subrec, &nmb->question.question_name, FIND_SELF_NAME) == 0) { + DEBUG(1,("process_node_status_request: status request for name %s from IP %s on \ +subnet %s - name not found.\n", nmb_namestr(&nmb->question.question_name), + inet_ntoa(p->ip), subrec->subnet_name)); + + return; + } + + /* this is not an exact calculation. the 46 is for the stats buffer + and the 60 is to leave room for the header etc */ + bufend = &rdata[MAX_DGRAM_SIZE-1] - (18 + 46 + 60); + countptr = buf = rdata; + buf += 1; + buf0 = buf; + + names_added = 0; + + namerec = subrec->namelist; + + while (PTR_DIFF(bufend, buf) > 0) { + if( (namerec->data.source == SELF_NAME) || (namerec->data.source == PERMANENT_NAME) ) { + int name_type = namerec->name.name_type; + unstring name; + + pull_ascii_nstring(name, sizeof(name), namerec->name.name); + if (!strupper_m(name)) { + DEBUG(2,("strupper_m %s failed\n", name)); + return; + } + if (!strequal(name,"*") && + !strequal(name,"__SAMBA__") && + (name_type < 0x1b || name_type >= 0x20 || + ques_type < 0x1b || ques_type >= 0x20 || + strequal(qname, name))) { + /* Start with the name. */ + size_t len; + push_ascii_nstring(buf, name); + len = strlen(buf); + memset(buf + len, ' ', MAX_NETBIOSNAME_LEN - len - 1); + buf[MAX_NETBIOSNAME_LEN - 1] = '\0'; + + /* Put the name type and netbios flags in the buffer. */ + + buf[15] = name_type; + set_nb_flags( &buf[16],namerec->data.nb_flags ); + buf[16] |= NB_ACTIVE; /* all our names are active */ + + names_added++; + } + } + + /* Remove duplicate names. */ + if (names_added > 1) { + /* TODO: should use a real type and + TYPESAFE_QSORT() */ + qsort( buf0, names_added, 18, QSORT_CAST status_compare ); + } + + for( i=1; i < names_added ; i++ ) { + if (memcmp(buf0 + 18*i,buf0 + 18*(i-1),16) == 0) { + names_added--; + if (names_added == i) + break; + memmove(buf0 + 18*i,buf0 + 18*(i+1),18*(names_added-i)); + i--; + } + } + + buf = buf0 + 18*names_added; + + namerec = namerec->next; + + if (!namerec) { + /* End of the subnet specific name list. Now + add the names on the unicast subnet . */ + struct subnet_record *uni_subrec = unicast_subnet; + + if (uni_subrec != subrec) { + subrec = uni_subrec; + namerec = subrec->namelist; + } + } + if (!namerec) + break; + + } + + SCVAL(countptr,0,names_added); + + /* We don't send any stats as they could be used to attack + the protocol. */ + memset(buf,'\0',46); + + buf += 46; + + /* Send a NODE STATUS RESPONSE */ + reply_netbios_packet(p, /* Packet to reply to. */ + 0, /* Result code. */ + NMB_STATUS, /* nmbd type code. */ + NMB_NAME_QUERY_OPCODE, /* opcode. */ + 0, /* ttl. */ + rdata, /* data to send. */ + PTR_DIFF(buf,rdata)); /* data length. */ +} + + +/*************************************************************************** +Process a name query. + +For broadcast name queries: + + - Only reply if the query is for one of YOUR names. + - NEVER send a negative response to a broadcast query. + +****************************************************************************/ + +void process_name_query_request(struct subnet_record *subrec, struct packet_struct *p) +{ + struct nmb_packet *nmb = &p->packet.nmb; + struct nmb_name *question = &nmb->question.question_name; + int name_type = question->name_type; + bool bcast = nmb->header.nm_flags.bcast; + int ttl=0; + int rcode = 0; + char *prdata = NULL; + char rdata[6]; + bool success = False; + struct name_record *namerec = NULL; + int reply_data_len = 0; + int i; + + DEBUG(3,("process_name_query_request: Name query from %s on subnet %s for name %s\n", + inet_ntoa(p->ip), subrec->subnet_name, nmb_namestr(question))); + + /* Look up the name in the cache - if the request is a broadcast request that + came from a subnet we don't know about then search all the broadcast subnets + for a match (as we don't know what interface the request came in on). */ + + if(subrec == remote_broadcast_subnet) + namerec = find_name_for_remote_broadcast_subnet( question, FIND_ANY_NAME); + else + namerec = find_name_on_subnet(subrec, question, FIND_ANY_NAME); + + /* Check if it is a name that expired */ + if (namerec && + ((namerec->data.death_time != PERMANENT_TTL) && + (namerec->data.death_time < p->timestamp))) { + DEBUG(5,("process_name_query_request: expired name %s\n", nmb_namestr(&namerec->name))); + namerec = NULL; + } + + if (namerec) { + /* + * Always respond to unicast queries. + * Don't respond to broadcast queries unless the query is for + * a name we own, a Primary Domain Controller name, or a WINS_PROXY + * name with type 0 or 0x20. WINS_PROXY names are only ever added + * into the namelist if we were configured as a WINS proxy. + */ + + if (!bcast || + (bcast && ((name_type == 0x1b) || + (namerec->data.source == SELF_NAME) || + (namerec->data.source == PERMANENT_NAME) || + ((namerec->data.source == WINS_PROXY_NAME) && + ((name_type == 0) || (name_type == 0x20)))))) { + /* The requested name is a directed query, or it's SELF or PERMANENT or WINS_PROXY, + or it's a Domain Master type. */ + + /* + * If this is a WINS_PROXY_NAME, then check that none of the IP + * addresses we are returning is on the same broadcast subnet + * as the requesting packet. If it is then don't reply as the + * actual machine will be replying also and we don't want two + * replies to a broadcast query. + */ + + if (namerec->data.source == WINS_PROXY_NAME) { + for( i = 0; i < namerec->data.num_ips; i++) { + if (same_net_v4(namerec->data.ip[i], subrec->myip, subrec->mask_ip)) { + DEBUG(5,("process_name_query_request: name %s is a WINS proxy name and is also on the same subnet (%s) as the requester. Not replying.\n", + nmb_namestr(&namerec->name), subrec->subnet_name )); + return; + } + } + } + + ttl = (namerec->data.death_time != PERMANENT_TTL) ? + namerec->data.death_time - p->timestamp : lp_max_ttl(); + + /* Copy all known ip addresses into the return data. */ + /* Optimise for the common case of one IP address so + we don't need a malloc. */ + + if (namerec->data.num_ips == 1) { + prdata = rdata; + } else { + if ((prdata = (char *)SMB_MALLOC( namerec->data.num_ips * 6 )) == NULL) { + DEBUG(0,("process_name_query_request: malloc fail !\n")); + return; + } + } + + for (i = 0; i < namerec->data.num_ips; i++) { + set_nb_flags(&prdata[i*6],namerec->data.nb_flags); + putip((char *)&prdata[2+(i*6)], &namerec->data.ip[i]); + } + + sort_query_replies(prdata, i, p->ip); + + reply_data_len = namerec->data.num_ips * 6; + success = True; + } + } + + /* + * If a machine is broadcasting a name lookup request and we have lp_wins_proxy() + * set we should initiate a WINS query here. On success we add the resolved name + * into our namelist with a type of WINS_PROXY_NAME and then reply to the query. + */ + + if(!success && (namerec == NULL) && we_are_a_wins_client() && lp_wins_proxy() && + bcast && (subrec != remote_broadcast_subnet)) { + make_wins_proxy_name_query_request( subrec, p, question ); + return; + } + + if (!success && bcast) { + if(prdata != rdata) + SAFE_FREE(prdata); + return; /* Never reply with a negative response to broadcasts. */ + } + + /* + * Final check. From observation, if a unicast packet is sent + * to a non-WINS server with the recursion desired bit set + * then never send a negative response. + */ + + if(!success && !bcast && nmb->header.nm_flags.recursion_desired) { + if(prdata != rdata) + SAFE_FREE(prdata); + return; + } + + if (success) { + rcode = 0; + DEBUG(3,("OK\n")); + } else { + rcode = NAM_ERR; + DEBUG(3,("UNKNOWN\n")); + } + + /* See rfc1002.txt 4.2.13. */ + + reply_netbios_packet(p, /* Packet to reply to. */ + rcode, /* Result code. */ + NMB_QUERY, /* nmbd type code. */ + NMB_NAME_QUERY_OPCODE, /* opcode. */ + ttl, /* ttl. */ + prdata, /* data to send. */ + reply_data_len); /* data length. */ + + if(prdata != rdata) + SAFE_FREE(prdata); +} |