/* DESC: This script will execute commands received by SMS.
* Copyright (C) 2012 NetModule AG, Switzerland
*
* sms-commands:
* <reboot>: reboot netmodule router
* <connect>: configure wanlink 0 permanent
* <disconnect>: configure wanlink 0 disable
* <status>: get system status summary
* <output [1|2] [on|off]> set dio n on or off
*/
INTERVAL = 10; /* only run every 10 seconds */
MAXMSG = 5; /* process max. 5 msgs */
MAXAGE = 300; /* message mustn't be older than 5 mins */
MAXLINES = 32; /* max. number of lines in msg (incl. header) */
AUTH = 1; /* perform authentication */
ADMPWD = ""; /* password used for authentication */
IGNORECASE = 1; /* ignore upper-/lower-case */
SENDERS = mkarray(/* "+123456789" */); /* allowed senders */
/* check if we should perform authentication */
if (argc == 2 && argv[1] == "noauth") {
AUTH = 0;
}
/* retrieve password */
if (AUTH) {
if (strlen(ADMPWD) == 0) {
/* use configured admin password */
ADMPWD = nb_config_get("admin.password");
if (strlen(ADMPWD) > 0) {
nb_syslog("using admin password for authentication");
} else {
/* not there -> use a default password instead */
nb_syslog("using default password for authentication");
ADMPWD = "admin01";
}
}
if (IGNORECASE) ADMPWD = tolower(ADMPWD);
}
/* split a message into an array */
array split(string msg) {
args=mkarray();
pos=strchr(msg, "\r");
if(pos==0) msg="";
if(pos>0) msg=left(msg, pos);
pos=strchr(msg, "\n");
if(pos==0) msg="";
if(pos>0) msg=left(msg, pos);
for(n=0;;) {
pos=strchr(msg, " ");
if(is_void(pos)) pos=strchr(msg, "\t");
if(is_void(pos)) pos=strchr(msg, "\f");
if(pos==0) {
msg=trim(msg);
} else if(pos>0) {
args[n++]=trim(left(msg, pos));
msg=trim(substr(msg, pos));
} else {
if(msg!="") args[n++]=trim(msg);
break;
}
}
return args;
}
/* parse message */
array parse (string msg)
{
/* read by line */
lnr = 0;
ishdr = 1;
tlnr = 0;
allowed = (length(SENDERS) == 0) ? 1 : 0;
lp = msg;
for (lnr = 0; lnr < MAXLINES && strlen(lp) > 0; lnr++) {
pos = strchr(lp, "\n");
if (is_void(pos)) pos = strlen(lp);
line = left(lp, pos);
lp = substr(lp, pos + 1);
if (strlen(line) == 0) {
/* saw header separator */
ishdr = 0;
continue;
}
if (ishdr) {
/* saw header line */
if (left(line, 5) == "Sent:") {
/* check age of message */
sentdate = trim(substr(line, 5));
sent = strptime(sentdate, "%Y-%m-%d %H:%M:%S");
if (!is_void(sent)) {
/* got a valid sent date */
now = localtime(time());
age = mktime(now) - mktime(sent);
nb_syslog("message has been sent %ds ago", age);
if (age > MAXAGE) {
nb_syslog("rejecting too old message");
return mkarray();
}
} else {
nb_syslog("time check has been omitted");
}
} else if (left(line, 5) == "From:") {
from = substr(line, 6);
if (length(SENDERS) > 0) {
for (s = 0; s < length(SENDERS); s++) {
sender = SENDERS[s];
if (left(from, strlen(sender)) == sender) {
allowed = 1;
break;
}
}
}
if (allowed == 0) {
nb_syslog("rejecting message from unknown sender %s", from);
return mkarray();
} else {
nb_syslog("sender %s can pass", from);
}
}
} else {
/* saw text line */
if (IGNORECASE) line = tolower(line);
if (AUTH && tlnr == 0) {
/* first line of message must contain the password */
if (left(line, strlen(ADMPWD)) != ADMPWD) {
nb_syslog("authentication failed");
return mkarray();
} else {
nb_syslog("authentication succeeded");
}
} else if ((AUTH && tlnr == 1) || (!AUTH && tlnr == 0)) {
/* this line must contain the command */
return split(line);
} else {
break;
}
tlnr++;
}
}
nb_syslog("no command detected");
return mkarray();
}
int setdio (string port, string newstate)
{
if (port != "1" && port != "2") {
nb_syslog("invalid DIO port %s\n", port);
return -1;
}
if (newstate == "on") {
st = 1;
} else if (newstate == "off") {
st = 0;
} else {
nb_syslog("invalid new DIO state %s\n", newstate);
return -1;
}
rc = nb_dio_set(sprintf("out%s", port), st);
if (rc) {
nb_syslog("Unable to set state %s for DIO output port %s\n", newstate, port);
return -1;
} else {
nb_syslog("Setting state %s for DIO output port %s\n", newstate, port);
return 0;
}
}
/* check if we got stressed */
LASTFILE = "/tmp/sms-control.last";
last = 0;
fp = fopen(LASTFILE, "r");
if (fp) {
/* we have been run at least one time */
str = fread(fp, 32);
if (str) last = (int) str;
fclose(fp);
}
now = mktime(localtime(time()));
elapsed = now - last;
if (elapsed > 0 && elapsed < INTERVAL) {
nb_syslog("we have ben run %d seconds ago. skipping.", elapsed);
exit(0);
}
/* record timestamp */
fp = fopen(LASTFILE, "w+");
if (fp) {
str = sprintf("%d", now);
fwrite(fp, str);
fclose(fp);
}
/* read inbox */
msgs = nb_sms_list();
nr_msgs = length(msgs);
if (nr_msgs == 0) {
nb_syslog("there are no messages in your inbox");
exit(0);
}
nb_syslog("you have %d message(s) in your inbox", nr_msgs);
/* track states */
reboot = 0;
/* only process latest messages */
start = nr_msgs - MAXMSG;
if (start < 0) start = 0;
for (i=start; i<nr_msgs; i++) {
msg = nb_sms_retrieve(msgs[i]);
if (!msg) continue;
nb_syslog("processing message %d of %d (ID %s)",
i, nr_msgs, msgs[i]);
args = parse(msg);
if ((is_array(args)) && (length(args) > 0)) {
if (args[0] == "") {
nb_syslog("no command");
} else if ((args[0] == "reboot") && (length(args) == 1)) {
nb_syslog("reboot command received");
reboot = 1;
} else if ((args[0] == "connect") && (length(args) == 1)) {
nb_syslog("connect command received");
if (nb_config_get("wanlink.0.mode") == "1") {
nb_syslog("already connecting");
} else {
/* enable first wanlink */
nb_config_set("wanlink.0.mode=1");
}
} else if ((args[0] == "disconnect") && (length(args) == 1)) {
nb_syslog("disconnect command received");
if (nb_config_get("wanlink.0.mode") == "0") {
nb_syslog("already disconnecting");
} else {
/* disable first wanlink */
nb_config_set("wanlink.0.mode=0");
}
} else if ((args[0] == "status") && (length(args) == 1)) {
nb_syslog("status command received");
rcpt = nb_sms_header(msgs[i], "From");
if (rcpt) {
id = nb_sms_send(rcpt, nb_status_summary());
if (!id) {
nb_syslog("unable to send status message to %s", rcpt);
} else {
nb_syslog("successfully queued status message to %s (ID %s)", rcpt, id);
}
}
} else if ((args[0] == "output") && (length(args) == 3)) {
nb_syslog("dio out command received");
setdio(args[1], args[2]);
} else {
nb_syslog("command <%s> not supported", msg);
}
} else {
nb_syslog("ignoring invalid message");
}
/* delete message */
ret = nb_sms_delete(msgs[i]);
if (ret == 0) nb_syslog("deleted message %s", msgs[i]);
}
if (reboot == 1) {
/* trigger reboot */
nb_syslog("rebooting system");
nb_reboot();
}
exit(0);
