+ if (strcasecmp ("help", opt) == 0)
+ usage_qos_exit (/* arg = */ NULL, /* status = */ EXIT_SUCCESS);
+ /* DiffServ (RFC 2474): */
+ /* - Best effort (BE) */
+ else if (strcasecmp ("be", opt) == 0)
+ opt_send_qos = 0;
+ /* - Expedited Forwarding (EF, RFC 3246) */
+ else if (strcasecmp ("ef", opt) == 0)
+ opt_send_qos = 0xB8; /* == 0x2E << 2 */
+ /* - Voice Admit (VA, RFC 5865) */
+ else if (strcasecmp ("va", opt) == 0)
+ opt_send_qos = 0xB0; /* == 0x2D << 2 */
+ /* - Assured Forwarding (AF, RFC 2597) */
+ else if ((strncasecmp ("af", opt, strlen ("af")) == 0)
+ && (strlen (opt) == 4))
+ {
+ uint8_t dscp;
+ uint8_t class = 0;
+ uint8_t prec = 0;
+
+ /* There are four classes, AF1x, AF2x, AF3x, and AF4x. */
+ if (opt[2] == '1')
+ class = 1;
+ else if (opt[2] == '2')
+ class = 2;
+ else if (opt[2] == '3')
+ class = 3;
+ else if (opt[2] == '4')
+ class = 4;
+ else
+ usage_qos_exit (/* arg = */ opt, /* status = */ EXIT_SUCCESS);
+
+ /* In each class, there are three precedences, AFx1, AFx2, and AFx3 */
+ if (opt[3] == '1')
+ prec = 1;
+ else if (opt[3] == '2')
+ prec = 2;
+ else if (opt[3] == '3')
+ prec = 3;
+ else
+ usage_qos_exit (/* arg = */ opt, /* status = */ EXIT_SUCCESS);
+
+ dscp = (8 * class) + (2 * prec);
+ /* The lower two bits are used for Explicit Congestion Notification (ECN) */
+ opt_send_qos = dscp << 2;
+ }
+ /* - Class Selector (CS) */
+ else if ((strncasecmp ("cs", opt, strlen ("cs")) == 0)
+ && (strlen (opt) == 3))
+ {
+ uint8_t class;
+
+ if ((opt[2] < '0') || (opt[2] > '7'))
+ usage_qos_exit (/* arg = */ opt, /* status = */ EXIT_FAILURE);
+
+ /* Not exactly legal by the C standard, but I don't know of any
+ * system not supporting this hack. */
+ class = ((uint8_t) opt[2]) - ((uint8_t) '0');
+ opt_send_qos = class << 5;
+ }
+ /* Type of Service (RFC 1349) */
+ else if (strcasecmp ("lowdelay", opt) == 0)
+ opt_send_qos = IPTOS_LOWDELAY;