[PKTGEN]: DSCP support

Anyway, I've been asked to add support for managing DSCP codepoints,
so one can test DiffServ capable routers. It's very simple code and is
working for me.

Signed-off-by: Francesco Fondelli <francesco.fondelli@gmail.com>
Signed-off-by: Robert Olsson <robert.olsson@its.uu.se>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/core/pktgen.c

@@ -160,7 +160,7 @@
 #include <asm/div64.h>		/* do_div */
 #include <asm/timex.h>
 
-#define VERSION  "pktgen v2.67: Packet Generator for packet performance testing.\n"
+#define VERSION  "pktgen v2.68: Packet Generator for packet performance testing.\n"
 
 /* #define PG_DEBUG(a) a */
 #define PG_DEBUG(a)
@@ -292,6 +292,10 @@ struct pktgen_dev {
 	__u16 udp_dst_min;	/* inclusive, dest UDP port */
 	__u16 udp_dst_max;	/* exclusive, dest UDP port */
 
+	/* DSCP + ECN */
+	__u8 tos;            /* six most significant bits of (former) IPv4 TOS are for dscp codepoint */
+	__u8 traffic_class;  /* ditto for the (former) Traffic Class in IPv6 (see RFC 3260, sec. 4) */
+
 	/* MPLS */
 	unsigned nr_labels;	/* Depth of stack, 0 = no MPLS */
 	__be32 labels[MAX_MPLS_LABELS];
@@ -671,6 +675,14 @@ static int pktgen_if_show(struct seq_file *seq, void *v)
 			   pkt_dev->svlan_id, pkt_dev->svlan_p, pkt_dev->svlan_cfi);
 	}
 
+	if (pkt_dev->tos) {
+		seq_printf(seq, "     tos: 0x%02x\n", pkt_dev->tos);
+	}
+
+	if (pkt_dev->traffic_class) {
+		seq_printf(seq, "     traffic_class: 0x%02x\n", pkt_dev->traffic_class);
+	}
+
 	seq_printf(seq, "     Flags: ");
 
 	if (pkt_dev->flags & F_IPV6)
@@ -748,12 +760,12 @@ static int pktgen_if_show(struct seq_file *seq, void *v)
 }
 
 
-static int hex32_arg(const char __user *user_buffer, __u32 *num)
+static int hex32_arg(const char __user *user_buffer, unsigned long maxlen, __u32 *num)
 {
 	int i = 0;
 	*num = 0;
 
-	for(; i < 8; i++) {
+	for(; i < maxlen; i++) {
 		char c;
 		*num <<= 4;
 		if (get_user(c, &user_buffer[i]))
@@ -848,7 +860,7 @@ static ssize_t get_labels(const char __user *buffer, struct pktgen_dev *pkt_dev)
 	pkt_dev->nr_labels = 0;
 	do {
 		__u32 tmp;
-		len = hex32_arg(&buffer[i], &tmp);
+		len = hex32_arg(&buffer[i], 8, &tmp);
 		if (len <= 0)
 			return len;
 		pkt_dev->labels[n] = htonl(tmp);
@@ -1185,11 +1197,15 @@ static ssize_t pktgen_if_write(struct file *file,
 		else if (strcmp(f, "!SVID_RND") == 0)
 			pkt_dev->flags &= ~F_SVID_RND;
 
+		else if (strcmp(f, "!IPV6") == 0)
+			pkt_dev->flags &= ~F_IPV6;
+
 		else {
 			sprintf(pg_result,
 				"Flag -:%s:- unknown\nAvailable flags, (prepend ! to un-set flag):\n%s",
 				f,
-				"IPSRC_RND, IPDST_RND, TXSIZE_RND, UDPSRC_RND, UDPDST_RND, MACSRC_RND, MACDST_RND\n");
+				"IPSRC_RND, IPDST_RND, UDPSRC_RND, UDPDST_RND, "
+				"MACSRC_RND, MACDST_RND, TXSIZE_RND, IPV6, MPLS_RND, VID_RND, SVID_RND\n");
 			return count;
 		}
 		sprintf(pg_result, "OK: flags=0x%x", pkt_dev->flags);
@@ -1615,6 +1631,38 @@ static ssize_t pktgen_if_write(struct file *file,
 		return count;
 	}
 
+	if (!strcmp(name, "tos")) {
+		__u32 tmp_value = 0;
+		len = hex32_arg(&user_buffer[i], 2, &tmp_value);
+		if (len < 0) {
+			return len;
+		}
+		i += len;
+		if (len == 2) {
+			pkt_dev->tos = tmp_value;
+			sprintf(pg_result, "OK: tos=0x%02x", pkt_dev->tos);
+		} else {
+			sprintf(pg_result, "ERROR: tos must be 00-ff");
+		}
+		return count;
+	}
+
+	if (!strcmp(name, "traffic_class")) {
+		__u32 tmp_value = 0;
+		len = hex32_arg(&user_buffer[i], 2, &tmp_value);
+		if (len < 0) {
+			return len;
+		}
+		i += len;
+		if (len == 2) {
+			pkt_dev->traffic_class = tmp_value;
+			sprintf(pg_result, "OK: traffic_class=0x%02x", pkt_dev->traffic_class);
+		} else {
+			sprintf(pg_result, "ERROR: traffic_class must be 00-ff");
+		}
+		return count;
+	}
+
 	sprintf(pkt_dev->result, "No such parameter \"%s\"", name);
 	return -EINVAL;
 }
@@ -2339,7 +2387,7 @@ static struct sk_buff *fill_packet_ipv4(struct net_device *odev,
 	iph->ihl = 5;
 	iph->version = 4;
 	iph->ttl = 32;
-	iph->tos = 0;
+	iph->tos = pkt_dev->tos;
 	iph->protocol = IPPROTO_UDP;	/* UDP */
 	iph->saddr = pkt_dev->cur_saddr;
 	iph->daddr = pkt_dev->cur_daddr;
@@ -2680,6 +2728,11 @@ static struct sk_buff *fill_packet_ipv6(struct net_device *odev,
 
 	*(u32 *) iph = __constant_htonl(0x60000000);	/* Version + flow */
 
+	if (pkt_dev->traffic_class) {
+		/* Version + traffic class + flow (0) */
+		*(u32 *)iph |= htonl(0x60000000 | (pkt_dev->traffic_class << 20));
+	}
+
 	iph->hop_limit = 32;
 
 	iph->payload_len = htons(sizeof(struct udphdr) + datalen);