Hi Mark,

Mark Lumsden wrote on Thu, Sep 23, 2010 at 07:38:00AM +0000:

quoted text
> Add a check to the user supplied value of the local port.
[...]
quoted text
> ok?

No, not ok; i think the patch is incorrect.

The pflag is passed to getaddrinfo(3):

     int
     getaddrinfo(const char *hostname, const char *servname, const struct
     addrinfo *hints, struct addrinfo **res);

     The servname is either a decimal port number or a service name
     listed in services(5).

Thus, no input validation is desirable.
In fact, nc(1) already provides a (well, moderately) useful error
message when you provide a service not listed in services(5):

  schwarze@rhea $ nc -p murks localhost 30000
  nc: getaddrinfo: service not supported for ai_socktype

Yours,
  Ingo


quoted text
> Index: netcat.c
> ===================================================================
> RCS file: /cvs/src/usr.bin/nc/netcat.c,v
> retrieving revision 1.98
> diff -u -p -r1.98 netcat.c
> --- netcat.c	3 Jul 2010 04:44:51 -0000	1.98
> +++ netcat.c	23 Sep 2010 07:13:51 -0000
> @@ -174,6 +174,9 @@ main(int argc, char *argv[])
>  			Pflag = optarg;
>  			break;
>  		case 'p':
> +			strtonum(optarg, 1, PORT_MAX, &errstr);
> +			if (errstr)
> +				errx(1, "source port %s: %s", errstr, optarg);
>  			pflag = optarg;
>  			break;
>  		case 'r':