smtpd: allow arguments on NOOP

[Omar Polo]

another diff from the -portable repo:

        https://github.com/OpenSMTPD/OpenSMTPD/pull/1150

per rfc-5321 § 4.1.1.9 the NOOP command allows optionally one argument
that we SHOULD ignore.

The original diff set the check function in the commands table to NULL
because NOOP is not a phase that can have filters.  However, I prefer
to stay on the safe side and add a smtp_check_noop() function.
Alternatively, we could allow a NULL check function in
smtp_session_imsg().

the rfc specifies only one optional string, while here for semplicity
it's relaxed to allow anything.


diff /usr/src
commit - 8def1c1c2777f0b5175283f8116e1eaab1f1962a
path + /usr/src
blob - 1686f03e96deeb5e6ea8b065456e04c27c752c8c
file + usr.sbin/smtpd/smtp_session.c
--- usr.sbin/smtpd/smtp_session.c
+++ usr.sbin/smtpd/smtp_session.c
@@ -212,6 +212,7 @@ static int  smtp_check_noparam(struct smtp_session *, 
 static int  smtp_check_mail_from(struct smtp_session *, const char *);
 static int  smtp_check_rcpt_to(struct smtp_session *, const char *);
 static int  smtp_check_data(struct smtp_session *, const char *);
+static int  smtp_check_noop(struct smtp_session *, const char *);
 static int  smtp_check_noparam(struct smtp_session *, const char *);
 
 static void smtp_filter_phase(enum filter_phase, struct smtp_session *, const 
char *);
@@ -276,7 +277,7 @@ static struct {
        { CMD_DATA,             FILTER_DATA,            "DATA",         
smtp_check_data,        smtp_proceed_data },
        { CMD_RSET,             FILTER_RSET,            "RSET",         
smtp_check_rset,        smtp_proceed_rset },
        { CMD_QUIT,             FILTER_QUIT,            "QUIT",         
smtp_check_noparam,     smtp_proceed_quit },
-       { CMD_NOOP,             FILTER_NOOP,            "NOOP",         
smtp_check_noparam,     smtp_proceed_noop },
+       { CMD_NOOP,             FILTER_NOOP,            "NOOP",         
smtp_check_noop,        smtp_proceed_noop },
        { CMD_HELP,             FILTER_HELP,            "HELP",         
smtp_check_noparam,     smtp_proceed_help },
        { CMD_WIZ,              FILTER_WIZ,             "WIZ",          
smtp_check_noparam,     smtp_proceed_wiz },
        { CMD_COMMIT,           FILTER_COMMIT,          ".",            
smtp_check_noparam,     smtp_proceed_commit },
@@ -1343,8 +1344,8 @@ smtp_command(struct smtp_session *s, char *line)
                break;
 
        case CMD_NOOP:
-               if (!smtp_check_noparam(s, args))
-                       break;          
+               if (!smtp_check_noop(s, args))
+                       break;
                smtp_filter_phase(FILTER_NOOP, s, NULL);
                break;
 
@@ -1631,6 +1632,12 @@ smtp_check_noparam(struct smtp_session *s, const char 
 }
 
 static int
+smtp_check_noop(struct smtp_session *s, const char *args)
+{
+       return 1;
+}
+
+static int
 smtp_check_noparam(struct smtp_session *s, const char *args)
 {
        if (args != NULL) {