.TH GSMACCESS 5 "Project SMSLink" "Les Ateliers du Heron" \" -*- nroff -*-.SH NAMEgsmaccess \- SMSLink server access control list file.SH DESCRIPTION.B gsmaccessis an ASCII file which contains entries (rules) defining potentialclient's access rights to the server (in simple terms of allow / deny).Each rule will qualify as an "allow" or a "deny" rule, specifying thenetwork number or individual IP address to which the rule apply and asubnet mask expressed as a single decimal digit..PPThere is one entry per line, and each line has the format:.sp.RSaccess:network/netmask.RE.spLines beginning with '#' are treated as comments and ignored. Emptylines are allowed and ignored. Invalid entries are silently ignored..spThe field descriptions are:.sp.RS.TP 1.0in.I accessa single character, either 'n'.RB "(=" deny ")"or 'y'.RB "(=" allow ")."The presence of this character is required. It is not case-sensitive..TP.I networka network number or IP address expressed as a dotted quad..TP.I netmaska subnet mask expressed as a single decimal value (representing thenumber of bits set in the mask). A mask of.B 32would mean that the preceeding dotted quad represented an individualIP address..SH SECURITY POLICYIf the file.B /etc/gsmaccessexists and can be read, the policy is to enable access control (even if thefile is empty or doesn't contain any valid rule), and to deny access bydefault. All rules contained in the file are parsed in their successiveorder, and the first to match the client's IP address applies. When nomatch can be found, access is denied by default. To revert the policy toa "default allow", use only negative rules and set "y:0.0.0.0/0" as thelast one..PPWhen the file is absent, the access control is disabled altogether..SH EXAMPLES.B y:0.0.0.0/0.brgrants access to anyone..PP.B y:192.1.1.0/24.br.B n:192.1.1.7/32.brgrants access to anyone on the 192.1.1.0 subnet with mask 255.255.255.0but specifically denies access to the machine whose IP address is192.1.1.7..PP.B n:192.1.1.0/24.br.B n:192.1.2.0/24.br.B y:0.0.0.0/0.brcloses access to a few networks and opens it to anything else..SH FILES.B /etc/gsmaccess.SH SEE ALSO.BR sms_serv "(1), " sendsms "(1), " gsmdevices "(5)"