Merge branch 'master' of git@192.168.100.10:openbsc
diff --git a/hlrsync/hlrsync.py b/hlrsync/hlrsync.py
new file mode 100755
index 0000000..b2a632b
--- /dev/null
+++ b/hlrsync/hlrsync.py
@@ -0,0 +1,103 @@
+#!/usr/bin/python2.5
+
+from __future__ import with_statement
+
+from pysqlite2 import dbapi2 as sqlite3
+import sys
+
+hlr = sqlite3.connect(sys.argv[1])
+web = sqlite3.connect(sys.argv[2])
+
+# switch to autocommit
+hlr.isolation_level = None
+web.isolation_level = None
+
+hlr.row_factory = sqlite3.Row
+web.row_factory = sqlite3.Row
+
+with hlr:
+ hlr_subscrs = hlr.execute("""
+ SELECT * FROM Subscriber
+ """).fetchall()
+ hlr_tokens = hlr.execute("""
+ SELECT * FROM AuthToken
+ """).fetchall()
+
+with web:
+ web_tokens = web.execute("""
+ SELECT * FROM reg_tokens
+ """).fetchall()
+
+# index by subscr id
+hlr_subscrs_by_id = {}
+hlr_tokens_by_subscr_id = {}
+for x in hlr_subscrs:
+ hlr_subscrs_by_id[x['id']] = x
+del hlr_subscrs
+for x in hlr_tokens:
+ hlr_tokens_by_subscr_id[x['subscriber_id']] = x
+del hlr_tokens
+
+web_tokens_by_subscr_id = {}
+for x in web_tokens:
+ web_tokens_by_subscr_id[x['subscriber_id']] = x
+del web_tokens
+
+# remove leftover web_tokens and correct inconsistent fields
+with web:
+ for x in web_tokens_by_subscr_id.values():
+ subscr = hlr_subscrs_by_id.get(x['subscriber_id'], None)
+ if subscr is None:
+ web.execute("""
+ DELETE FROM reg_tokens WHERE subscriber_id = ?
+ """, (x['subscriber_id'],))
+ del web_tokens_by_subscr_id[x['subscriber_id']]
+ continue
+ if str(x['imsi']) != str(subscr['imsi']) or \
+ x['extension'] != subscr['extension'] or \
+ x['tmsi'] != subscr['tmsi'] or \
+ x['lac'] != subscr['lac']:
+ web.execute("""
+ UPDATE reg_tokens
+ SET imsi = ?, extension = ?, tmsi = ?, lac = ?
+ WHERE subscriber_id = ?
+ """, (str(subscr['imsi']), subscr['extension'], x['subscriber_id']))
+ x['imsi'] = str(subscr['imsi'])
+ x['extension'] = subscr['extension']
+ x['tmsi'] = subscr['tmsi']
+ x['lac'] = subscr['lac']
+
+# add missing web_tokens
+with web:
+ for x in hlr_tokens_by_subscr_id.values():
+ subscr = hlr_subscrs_by_id.get(x['subscriber_id'], None)
+ if subscr is None:
+ hlr.execute("""
+ DELETE FROM AuthToken WHERE subscriber_id = ?
+ """, (x['subscriber_id'],))
+ del hlr_tokens_by_subscr_id[x['subscriber_id']]
+ continue
+ webtoken = web_tokens_by_subscr_id.get(x['subscriber_id'], None)
+ if webtoken is None:
+ web.execute("""
+ INSERT INTO reg_tokens
+ (subscriber_id, extension, reg_completed, name, email, lac, imsi, token, tmsi)
+ VALUES
+ (?, ?, 0, ?, '', ?, ?, ?, ?)
+ """, (x['subscriber_id'], subscr['extension'], subscr['name'],
+ subscr['lac'], str(subscr['imsi']), x['token'], subscr['tmsi']))
+
+# authorize subscribers
+with hlr:
+ for x in web_tokens_by_subscr_id.values():
+ subscr = hlr_subscrs_by_id.get(x['subscriber_id'], None)
+ if x['reg_completed'] and not subscr['authorized']:
+ hlr.execute("""
+ UPDATE Subscriber
+ SET authorized = 1
+ WHERE id = ?
+ """, (x['subscriber_id'],))
+
+hlr.close()
+web.close()
+
diff --git a/openbsc/include/openbsc/gsm_data.h b/openbsc/include/openbsc/gsm_data.h
index 1a6a72a..4bdca2a 100644
--- a/openbsc/include/openbsc/gsm_data.h
+++ b/openbsc/include/openbsc/gsm_data.h
@@ -302,6 +302,8 @@
* rather than starting from TRX0 and go upwards? */
int chan_alloc_reverse;
int cell_barred;
+ /* maximum Tx power that the MS is permitted to use in this cell */
+ int ms_max_power;
/* how do we talk OML with this TRX? */
struct gsm_e1_subslot oml_e1_link;
diff --git a/openbsc/include/openbsc/signal.h b/openbsc/include/openbsc/signal.h
index 0dc1772..1af8496 100644
--- a/openbsc/include/openbsc/signal.h
+++ b/openbsc/include/openbsc/signal.h
@@ -83,7 +83,6 @@
enum signal_subscr {
S_SUBSCR_ATTACHED,
S_SUBSCR_DETACHED,
- S_SUBSCR_FIRST_CONTACT,
};
typedef int signal_cbfn(unsigned int subsys, unsigned int signal,
diff --git a/openbsc/src/abis_rsl.c b/openbsc/src/abis_rsl.c
index f107216..d54f2fd 100644
--- a/openbsc/src/abis_rsl.c
+++ b/openbsc/src/abis_rsl.c
@@ -1082,7 +1082,7 @@
arfcn = lchan->ts->trx->arfcn;
subch = lchan->nr;
- lchan->ms_power = ms_pwr_ctl_lvl(bts->band, 20 /* dBm == 100mW */);
+ lchan->ms_power = ms_pwr_ctl_lvl(bts->band, bts->ms_max_power);
lchan->bs_power = 0; /* 0dB reduction, output power = Pn */
lchan->rsl_cmode = RSL_CMOD_SPD_SIGN;
rsl_chan_activate_lchan(lchan, 0x00, rqd_ta);
diff --git a/openbsc/src/bsc_hack.c b/openbsc/src/bsc_hack.c
index 15bc70c..4253959 100644
--- a/openbsc/src/bsc_hack.c
+++ b/openbsc/src/bsc_hack.c
@@ -956,7 +956,7 @@
/* patch MS max power for CCH */
type_4->cell_sel_par.ms_txpwr_max_ccch =
- ms_pwr_ctl_lvl(bts->band, 20 /* dBm == 100mW */);
+ ms_pwr_ctl_lvl(bts->band, bts->ms_max_power);
if (bts->cell_barred) {
type_1->rach_control.cell_bar = 1;
@@ -1115,7 +1115,6 @@
printf(" -s --disable-color\n");
printf(" -c --config-file filename The config file to use.\n");
printf(" -l --database db-name The database to use\n");
- printf(" -a --authorize-everyone Allow everyone into the network.\n");
printf(" -r --reject-cause number The reject cause for LOCATION UPDATING REJECT.\n");
printf(" -p --pcap file The filename of the pcap file\n");
printf(" -C --cardnr number For bs11 select E1 card number other than 0\n");
@@ -1165,9 +1164,6 @@
case 'c':
config_file = strdup(optarg);
break;
- case 'a':
- gsm0408_allow_everyone(1);
- break;
case 'r':
gsm0408_set_reject_cause(atoi(optarg));
break;
@@ -1222,6 +1218,7 @@
int rc;
tall_bsc_ctx = talloc_named_const(NULL, 1, "openbsc");
+ on_dso_load_token();
/* parse options */
handle_options(argc, argv);
diff --git a/openbsc/src/db.c b/openbsc/src/db.c
index 938c5c4..0704bca 100644
--- a/openbsc/src/db.c
+++ b/openbsc/src/db.c
@@ -468,23 +468,24 @@
* an error.
*/
-int db_subscriber_alloc_token(struct gsm_subscriber* subscriber, u_int32_t* token) {
- dbi_result result=NULL;
+int db_subscriber_alloc_token(struct gsm_subscriber* subscriber, u_int32_t* token)
+{
+ dbi_result result;
u_int32_t try;
+
for (;;) {
try = rand();
if (!try) /* 0 is an invalid token */
continue;
result = dbi_conn_queryf(conn,
"SELECT * FROM AuthToken "
- "WHERE subscriber_id = %llu OR token = %08x ",
- subscriber->id, try
- );
- if (result==NULL) {
+ "WHERE subscriber_id = %llu OR token = \"%08X\" ",
+ subscriber->id, try);
+ if (!result) {
printf("DB: Failed to query AuthToken while allocating new token.\n");
return 1;
}
- if (dbi_result_get_numrows(result)){
+ if (dbi_result_get_numrows(result)) {
dbi_result_free(result);
continue;
}
@@ -498,15 +499,16 @@
"INSERT INTO AuthToken "
"(subscriber_id, created, token) "
"VALUES "
- "(%llu, datetime('now'), %08x)) ",
- subscriber->id, try
- );
- if (result==NULL) {
- printf("DB: Failed to create token %08x for IMSI %s.\n", try, subscriber->imsi);
+ "(%llu, datetime('now'), \"%08X\") ",
+ subscriber->id, try);
+ if (!result) {
+ printf("DB: Failed to create token %08X for IMSI %s.\n", try, subscriber->imsi);
return 1;
}
+ dbi_result_free(result);
*token = try;
- printf("DB: Allocated token %08x for IMSI %s.\n", try, subscriber->imsi);
+ printf("DB: Allocated token %08X for IMSI %s.\n", try, subscriber->imsi);
+
return 0;
}
diff --git a/openbsc/src/gsm_04_08.c b/openbsc/src/gsm_04_08.c
index f0ec3ff..03fe010 100644
--- a/openbsc/src/gsm_04_08.c
+++ b/openbsc/src/gsm_04_08.c
@@ -35,6 +35,7 @@
#include <openbsc/tlv.h>
#include <openbsc/debug.h>
#include <openbsc/gsm_data.h>
+#include <openbsc/gsm_utils.h>
#include <openbsc/gsm_subscriber.h>
#include <openbsc/gsm_04_11.h>
#include <openbsc/gsm_04_08.h>
@@ -304,13 +305,6 @@
u_int16_t lac;
};
-static int authorize_everonye = 0;
-void gsm0408_allow_everyone(int everyone)
-{
- printf("Allowing everyone?\n");
- authorize_everonye = everyone;
-}
-
static int reject_cause = 0;
void gsm0408_set_reject_cause(int cause)
{
@@ -333,10 +327,16 @@
if (loc && (loc->waiting_for_imsi || loc->waiting_for_imei))
return 0;
- if (authorize_everonye)
+ switch (subscriber->net->auth_policy) {
+ case GSM_AUTH_POLICY_CLOSED:
+ return subscriber->authorized;
+ case GSM_AUTH_POLICY_TOKEN:
+ return (subscriber->flags & GSM_SUBSCRIBER_FIRST_CONTACT);
+ case GSM_AUTH_POLICY_ACCEPT_ALL:
return 1;
-
- return subscriber->authorized;
+ default:
+ return 0;
+ }
}
static void release_loc_updating_req(struct gsm_lchan *lchan)
@@ -1154,12 +1154,8 @@
/* look up subscriber based on IMSI, create if not found */
if (!lchan->subscr) {
lchan->subscr = subscr_get_by_imsi(net, mi_string);
- }
- if (!lchan->subscr) {
- lchan->subscr = db_create_subscriber(net, mi_string);
- if (lchan->subscr->flags & GSM_SUBSCRIBER_FIRST_CONTACT) {
- dispatch_signal(SS_SUBSCR, S_SUBSCR_FIRST_CONTACT, &lchan->subscr);
- }
+ if (!lchan->subscr)
+ lchan->subscr = db_create_subscriber(net, mi_string);
}
if (lchan->loc_operation)
lchan->loc_operation->waiting_for_imsi = 0;
@@ -1256,9 +1252,6 @@
if (!subscr) {
subscr = db_create_subscriber(bts->network, mi_string);
}
- if (subscr->flags & GSM_SUBSCRIBER_FIRST_CONTACT) {
- dispatch_signal(SS_SUBSCR, S_SUBSCR_FIRST_CONTACT, &subscr);
- }
break;
case GSM_MI_TYPE_TMSI:
DEBUGPC(DMM, "\n");
@@ -1343,7 +1336,7 @@
struct gsm_network *net = lchan->ts->trx->bts->network;
u_int8_t *ptr8;
u_int16_t *ptr16;
- int name_len;
+ int name_len, name_pad;
int i;
#if 0
time_t cur_t;
@@ -1358,6 +1351,7 @@
gh->msg_type = GSM48_MT_MM_INFO;
if (net->name_long) {
+#if 0
name_len = strlen(net->name_long);
/* 10.5.3.5a */
ptr8 = msgb_put(msg, 3);
@@ -1371,9 +1365,24 @@
/* FIXME: Use Cell Broadcast, not UCS-2, since
* UCS-2 is only supported by later revisions of the spec */
+#endif
+ name_len = (strlen(net->name_long)*7)/8;
+ name_pad = (8 - strlen(net->name_long)*7)%8;
+ if (name_pad > 0)
+ name_len++;
+ /* 10.5.3.5a */
+ ptr8 = msgb_put(msg, 3);
+ ptr8[0] = GSM48_IE_NAME_LONG;
+ ptr8[1] = name_len +1;
+ ptr8[2] = 0x80 | name_pad; /* Cell Broadcast DCS, no CI */
+
+ ptr8 = msgb_put(msg, name_len);
+ gsm_7bit_encode(ptr8, net->name_long);
+
}
if (net->name_short) {
+#if 0
name_len = strlen(net->name_short);
/* 10.5.3.5a */
ptr8 = (u_int8_t *) msgb_put(msg, 3);
@@ -1384,6 +1393,20 @@
ptr16 = (u_int16_t *) msgb_put(msg, name_len*2);
for (i = 0; i < name_len; i++)
ptr16[i] = htons(net->name_short[i]);
+#endif
+ name_len = (strlen(net->name_short)*7)/8;
+ name_pad = (8 - strlen(net->name_short)*7)%8;
+ if (name_pad > 0)
+ name_len++;
+ /* 10.5.3.5a */
+ ptr8 = (u_int8_t *) msgb_put(msg, 3);
+ ptr8[0] = GSM48_IE_NAME_SHORT;
+ ptr8[1] = name_len +1;
+ ptr8[2] = 0x80 | name_pad; /* Cell Broadcast DCS, no CI */
+
+ ptr8 = msgb_put(msg, name_len);
+ gsm_7bit_encode(ptr8, net->name_short);
+
}
#if 0
@@ -1405,6 +1428,8 @@
ptr8[7] |= 0x80;
#endif
+ DEBUGP(DMM, "-> MM INFO\n");
+
return gsm48_sendmsg(msg, NULL);
}
diff --git a/openbsc/src/gsm_04_11.c b/openbsc/src/gsm_04_11.c
index 16c5c07..1b1368f 100644
--- a/openbsc/src/gsm_04_11.c
+++ b/openbsc/src/gsm_04_11.c
@@ -175,6 +175,10 @@
/* FIXME: implementation */
DEBUGP(DSMS, "VPI enhanced not implemented yet\n");
break;
+ case GSM340_TP_VPF_NONE:
+ /* Default validity: two days */
+ minutes = 24 * 60 * 2;
+ break;
}
return minutes;
}
@@ -272,6 +276,7 @@
u_int8_t *smsp;
u_int8_t oa[12]; /* max len per 03.40 */
u_int8_t oa_len = 0;
+ u_int8_t octet_len;
unsigned int old_msg_len = msg->len;
/* generate first octet with masked bits */
@@ -317,10 +322,13 @@
/* generate TP-UD */
/* FIXME: Handle DSC of UCS2 or 8/bit default */
if (gsm338_get_sms_alphabet(sms->data_coding_scheme) == DCS_7BIT_DEFAULT) {
+ octet_len = sms->user_data_len*7/8;
+ if (sms->user_data_len*7%8 != 0)
+ octet_len++;
/* Warning, user_data_len indicates the amount of septets
* (characters), we need amount of octets occupied */
- smsp = msgb_put(msg, ceil(sms->user_data_len*7/8.0));
- memcpy(smsp, sms->user_data, ceil(sms->user_data_len*7/8.0));
+ smsp = msgb_put(msg, octet_len);
+ memcpy(smsp, sms->user_data, octet_len);
}
return msg->len - old_msg_len;
@@ -383,6 +391,9 @@
sms_vp = smsp;
smsp += 7;
break;
+ case GSM340_TP_VPF_NONE:
+ sms_vp = 0;
+ break;
default:
DEBUGP(DSMS, "SMS Validity period not implemented: 0x%02x\n",
sms_vpf);
@@ -954,6 +965,8 @@
struct gsm_lchan *lchan;
struct gsm_sms *sms;
+ u_int32_t token;
+
switch (signal) {
case S_SUBSCR_ATTACHED:
/* A subscriber has attached. Check if there are
diff --git a/openbsc/src/gsm_data.c b/openbsc/src/gsm_data.c
index 22e8422..7e8100d 100644
--- a/openbsc/src/gsm_data.c
+++ b/openbsc/src/gsm_data.c
@@ -151,6 +151,7 @@
bts->bsic = bsic;
bts->num_trx = 0;
INIT_LLIST_HEAD(&bts->trx_list);
+ bts->ms_max_power = 15; /* dBm */
/* create our primary TRX */
bts->c0 = gsm_bts_trx_alloc(bts);
diff --git a/openbsc/src/token_auth.c b/openbsc/src/token_auth.c
index be951c4..6d4f14b 100644
--- a/openbsc/src/token_auth.c
+++ b/openbsc/src/token_auth.c
@@ -20,34 +20,94 @@
*
*/
+#include <stdio.h>
+#include <openbsc/talloc.h>
#include <openbsc/signal.h>
#include <openbsc/gsm_data.h>
#include <openbsc/gsm_04_11.h>
#include <openbsc/gsm_04_08.h>
#include <openbsc/gsm_subscriber.h>
+#include <openbsc/chan_alloc.h>
+#include <openbsc/db.h>
-#define TOKEN_SMS_TEXT "HAR 2009 GSM. Please visit http://127.0.0.1/ to register"
+#define TOKEN_SMS_TEXT "HAR 2009 GSM. Please visit http://har2009.gnumonks.org/ to" \
+ "register. Your IMSI is %s, your auth token is %08X."
+
+static char *build_sms_string(struct gsm_subscriber *subscr, u_int32_t token)
+{
+ char *sms_str;
+ unsigned int len;
+
+ len = strlen(subscr->imsi) + 8 + strlen(TOKEN_SMS_TEXT);
+ sms_str = talloc_size(tall_bsc_ctx, len);
+ if (!sms_str)
+ return NULL;
+
+ snprintf(sms_str, len, TOKEN_SMS_TEXT, subscr->imsi, token);
+ sms_str[len-1] = '\0';
+
+ return sms_str;
+}
static int token_subscr_cb(unsigned int subsys, unsigned int signal,
void *handler_data, void *signal_data)
{
struct gsm_subscriber *subscr = signal_data;
struct gsm_sms *sms;
+ int rc = 0;
if (subscr->net->auth_policy != GSM_AUTH_POLICY_TOKEN)
return 0;
- switch (signal) {
- case S_SUBSCR_FIRST_CONTACT:
+ if (signal != S_SUBSCR_ATTACHED)
+ return 0;
+
+ if (subscr->flags & GSM_SUBSCRIBER_FIRST_CONTACT) {
+ u_int32_t token;
+ char *sms_str;
+
/* we've seen this subscriber for the first time. */
- sms = sms_from_text(subscr, TOKEN_SMS_TEXT);
- if (!sms)
- return -ENOMEM;
- gsm411_send_sms_subscr(subscr, sms);
- break;
+ rc = db_subscriber_alloc_token(subscr, &token);
+ if (rc != 0) {
+ rc = -EIO;
+ goto unauth;
+ }
+
+ sms_str = build_sms_string(subscr, token);
+ if (!sms_str) {
+ rc = -ENOMEM;
+ goto unauth;
+ }
+
+ sms = sms_from_text(subscr, sms_str);
+ talloc_free(sms_str);
+ if (!sms) {
+ rc = -ENOMEM;
+ goto unauth;
+ }
+
+ rc = gsm411_send_sms_subscr(subscr, sms);
+
+ /* FIXME: else, delete the subscirber from database */
+unauth:
+
+ /* make sure we don't allow him in again unless he clicks the web UI */
+ subscr->authorized = 0;
+ db_sync_subscriber(subscr);
+ if (rc) {
+ struct gsm_lchan *lchan = lchan_for_subscr(subscr);
+ if (lchan) {
+ u_int8_t auth_rand[16];
+ /* kick the subscriber off the network */
+ gsm48_tx_mm_auth_req(lchan, auth_rand);
+ gsm48_tx_mm_auth_rej(lchan);
+ /* FIXME: close the channel early ?*/
+ //gsm48_send_rr_Release(lchan);
+ }
+ }
}
- return 0;
+ return rc;
}
static int token_sms_cb(unsigned int subsys, unsigned int signal,
@@ -55,37 +115,37 @@
{
struct gsm_sms *sms = signal_data;
struct gsm_lchan *lchan;
- u_int16_t rand[16];
+ u_int8_t auth_rand[16];
+
if (signal != S_SMS_DELIVERED)
return 0;
+
/* these are not the droids we've been looking for */
if (!sms->receiver ||
!(sms->receiver->flags & GSM_SUBSCRIBER_FIRST_CONTACT))
return 0;
+
if (sms->receiver->net->auth_policy != GSM_AUTH_POLICY_TOKEN)
return 0;
+
lchan = lchan_for_subscr(sms->receiver);
if (lchan) {
/* kick the subscriber off the network */
- gsm48_tx_mm_auth_req(lchan, rand);
+ gsm48_tx_mm_auth_req(lchan, auth_rand);
gsm48_tx_mm_auth_rej(lchan);
- /* close the channel */
+ /* FIXME: close the channel early ?*/
//gsm48_send_rr_Release(lchan);
- lchan_free(lchan);
}
- /* make sure we don't allow him in again unless he clicks the web UI */
- sms->receiver->authorized = 0;
- db_sync_subscriber(sms->receiver);
-
return 0;
}
-static __attribute__((constructor)) void on_dso_load_token(void)
+//static __attribute__((constructor)) void on_dso_load_token(void)
+void on_dso_load_token(void)
{
register_signal_handler(SS_SUBSCR, token_subscr_cb, NULL);
register_signal_handler(SS_SMS, token_sms_cb, NULL);
diff --git a/openbsc/src/vty_interface.c b/openbsc/src/vty_interface.c
index 70c5e01..4933bb4 100644
--- a/openbsc/src/vty_interface.c
+++ b/openbsc/src/vty_interface.c
@@ -233,6 +233,7 @@
VTY_NEWLINE);
vty_out(vty, " training_sequence_code %u%s", bts->tsc, VTY_NEWLINE);
vty_out(vty, " base_station_id_code %u%s", bts->bsic, VTY_NEWLINE);
+ vty_out(vty, " ms max power %u%s", bts->ms_max_power, VTY_NEWLINE);
vty_out(vty, " channel allocator %s%s",
bts->chan_alloc_reverse ? "descending" : "ascending",
VTY_NEWLINE);
@@ -975,6 +976,17 @@
return CMD_SUCCESS;
}
+DEFUN(cfg_bts_ms_max_power, cfg_bts_ms_max_power_cmd,
+ "ms max power <0-40>",
+ "Maximum transmit power of the MS")
+{
+ struct gsm_bts *bts = vty->index;
+
+ bts->ms_max_power = atoi(argv[0]);
+
+ return CMD_SUCCESS;
+}
+
/* per TRX configuration */
DEFUN(cfg_trx,
@@ -1205,11 +1217,10 @@
if (!receiver->lac) {
/* subscriber currently not attached, store in database? */
- subscr_put(sms->receiver);
return CMD_WARNING;
}
- sms->receiver = receiver;
+ sms->receiver = subscr_get(receiver);
strncpy(sms->text, text, sizeof(sms->text)-1);
/* FIXME: don't use ID 1 static */
@@ -1233,7 +1244,7 @@
sms = sms_from_text(receiver, buffer_getstr(b));
- gsm411_send_sms_subscr(sms->receiver, sms);
+ gsm411_send_sms_subscr(receiver, sms);
return CMD_SUCCESS;
}
@@ -1374,6 +1385,7 @@
install_element(BTS_NODE, &cfg_bts_oml_e1_tei_cmd);
install_element(BTS_NODE, &cfg_bts_challoc_cmd);
install_element(BTS_NODE, &cfg_bts_cell_barred_cmd);
+ install_element(BTS_NODE, &cfg_bts_ms_max_power_cmd);
install_element(BTS_NODE, &cfg_trx_cmd);