Select User-Agent field

Cisco device logs User-Agent: string, as explained in
http://www.cisco.com/en/US/docs/security/vpn_client/anyconnect/anyconnect23/release/notes/anyconnect23rn.html#wp908512
This patch let you change OpenConnect default User-Agent: string from
command line.

e.g. --useragent 'Cisco AnyConnect VPN Agent for Windows 2.2.0133'

Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

main.c

@@ -84,6 +84,7 @@ static struct option long_options[] = {
 	{"authgroup", 1, 0, '9'},
 	{"servercert", 1, 0, 0x01},
 	{"key-password-from-fsid", 0, 0, 0x02},
+	{"useragent", 1, 0, 0x03},
 	{NULL, 0, 0, 0},
 };
 
@@ -125,6 +126,7 @@ void usage(void)
 	printf("      --passwd-on-stdin           Read password from standard input\n");
 	printf("      --reconnect-timeout         Connection retry timeout in seconds\n");
 	printf("      --servercert                Server's certificate SHA1 fingerprint\n");
+	printf("      --useragent=STRING          HTTP header User-Agent: field\n");
 	exit(1);
 }
 
@@ -326,6 +328,10 @@ int main(int argc, char **argv)
 		case 0x02:
 			do_passphrase_from_fsid = 1;
 			break;
+		case 0x03:
+			free(vpninfo->useragent);
+			vpninfo->useragent = optarg;
+			break;
 		default:
 			usage();
 		}

openconnect.8

@@ -129,6 +129,10 @@ openconnect \- Connect to Cisco AnyConnect VPN
 .B --servercert
 .I FINGERPRINT
 ]
+[
+.B --useragent
+.I STRING
+]
 \fIserver\fR
 
 .SH DESCRIPTION
@@ -274,6 +278,10 @@ VPN connection after a temporary network down time of 300 seconds.
 .TP
 .B --servercert
 Accept server's SSL certificate only if its SHA1 fingerprint matches.
+.TP
+.B --useragent=STRING
+Use STRING as 'User-Agent:' field value in HTTP header.
+(e.g. --useragent 'Cisco AnyConnect VPN Agent for Windows 2.2.0133')
 
 .SH LIMITATIONS
 The