[v4] pktgen: Allow configuration of IPv6 source address range

[Niu Xilei <niu_xilei@163.com>]

Pktgen can use only one IPv6 source address from output device or src6
command setting. In pressure test we need create lots of sessions more
than 65535. So add src6_min and src6_max command to set the range.

Signed-off-by: Niu Xilei <niu_xilei@163.com>

Changes since v3:
 - function set_src_in6_addr use static instead of static inline
 - precompute min_in6_l,min_in6_h,max_in6_h,max_in6_l in setup time
Changes since v2:
 - reword subject line
Changes since v1:
 - only create IPv6 source address over least significant 64 bit range
---
 net/core/pktgen.c | 98 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 98 insertions(+)

diff --git a/net/core/pktgen.c b/net/core/pktgen.c
index 294bfcf0ce0e..890be1b4877e 100644
--- a/net/core/pktgen.c
+++ b/net/core/pktgen.c
@@ -323,6 +323,10 @@ struct pktgen_dev {
 	struct in6_addr max_in6_daddr;
 	struct in6_addr min_in6_saddr;
 	struct in6_addr max_in6_saddr;
+	u64  max_in6_h;
+	u64  max_in6_l;
+	u64  min_in6_h;
+	u64  min_in6_l;
 
 	/* If we're doing ranges, random or incremental, then this
 	 * defines the min/max for those ranges.
@@ -1355,6 +1359,59 @@ static ssize_t pktgen_if_write(struct file *file,
 		sprintf(pg_result, "OK: dst6_max=%s", buf);
 		return count;
 	}
+	if (!strcmp(name, "src6_min")) {
+		len = strn_len(&user_buffer[i], sizeof(buf) - 1);
+		if (len < 0)
+			return len;
+
+		pkt_dev->flags |= F_IPV6;
+
+		if (copy_from_user(buf, &user_buffer[i], len))
+			return -EFAULT;
+		buf[len] = 0;
+
+		in6_pton(buf, -1, pkt_dev->min_in6_saddr.s6_addr, -1, NULL);
+		snprintf(buf, sizeof(buf), "%pI6c", &pkt_dev->min_in6_saddr);
+
+		memcpy(&pkt_dev->min_in6_h, pkt_dev->min_in6_saddr.s6_addr, 8);
+		memcpy(&pkt_dev->min_in6_l, pkt_dev->min_in6_saddr.s6_addr + 8, 8);
+		pkt_dev->min_in6_h = be64_to_cpu(pkt_dev->min_in6_h);
+		pkt_dev->min_in6_l = be64_to_cpu(pkt_dev->min_in6_l);
+
+		pkt_dev->cur_in6_saddr = pkt_dev->min_in6_saddr;
+		if (debug)
+			pr_debug("src6_min set to: %s\n", buf);
+
+		i += len;
+		sprintf(pg_result, "OK: src6_min=%s", buf);
+		return count;
+	}
+	if (!strcmp(name, "src6_max")) {
+		len = strn_len(&user_buffer[i], sizeof(buf) - 1);
+		if (len < 0)
+			return len;
+
+		pkt_dev->flags |= F_IPV6;
+
+		if (copy_from_user(buf, &user_buffer[i], len))
+			return -EFAULT;
+		buf[len] = 0;
+
+		in6_pton(buf, -1, pkt_dev->max_in6_saddr.s6_addr, -1, NULL);
+		snprintf(buf, sizeof(buf), "%pI6c", &pkt_dev->max_in6_saddr);
+
+		memcpy(&pkt_dev->max_in6_h, pkt_dev->max_in6_saddr.s6_addr, 8);
+		memcpy(&pkt_dev->max_in6_l, pkt_dev->max_in6_saddr.s6_addr + 8, 8);
+		pkt_dev->max_in6_h = be64_to_cpu(pkt_dev->max_in6_h);
+		pkt_dev->max_in6_l = be64_to_cpu(pkt_dev->max_in6_l);
+
+		if (debug)
+			pr_debug("src6_max set to: %s\n", buf);
+
+		i += len;
+		sprintf(pg_result, "OK: src6_max=%s", buf);
+		return count;
+	}
 	if (!strcmp(name, "src6")) {
 		len = strn_len(&user_buffer[i], sizeof(buf) - 1);
 		if (len < 0)
@@ -2286,6 +2343,45 @@ static void set_cur_queue_map(struct pktgen_dev *pkt_dev)
 	pkt_dev->cur_queue_map  = pkt_dev->cur_queue_map % pkt_dev->odev->real_num_tx_queues;
 }
 
+/* generate ipv6 source addr */
+static void set_src_in6_addr(struct pktgen_dev *pkt_dev)
+{
+	u64 min6, max6, rand, i;
+	struct in6_addr addr6;
+	__be64 addr_l, *t;
+
+	min6 = pkt_dev->min_in6_l;
+	max6 = pkt_dev->max_in6_l;
+
+	/* only generate source address in least significant 64 bits range
+	 * most significant 64 bits must be equal
+	 */
+	if (pkt_dev->max_in6_h != pkt_dev->min_in6_h || min6 >= max6)
+		return;
+
+	addr6 = pkt_dev->min_in6_saddr;
+	t = (__be64 *)addr6.s6_addr + 1;
+
+	if (pkt_dev->flags & F_IPSRC_RND) {
+		do {
+			prandom_bytes(&rand, sizeof(rand));
+			rand = rand % (max6 - min6) + min6;
+			addr_l = cpu_to_be64(rand);
+			memcpy(t, &addr_l, 8);
+		} while (ipv6_addr_loopback(&addr6) ||
+			 ipv6_addr_v4mapped(&addr6) ||
+			 ipv6_addr_is_multicast(&addr6));
+	} else {
+		addr6 = pkt_dev->cur_in6_saddr;
+		i = be64_to_cpu(*t);
+		if (++i > max6)
+			i = min6;
+		addr_l = cpu_to_be64(i);
+		memcpy(t, &addr_l, 8);
+	}
+	pkt_dev->cur_in6_saddr = addr6;
+}
+
 /* Increment/randomize headers according to flags and current values
  * for IP src/dest, UDP src/dst port, MAC-Addr src/dst
  */
@@ -2454,6 +2550,8 @@ static void mod_cur_headers(struct pktgen_dev *pkt_dev)
 		}
 	} else {		/* IPV6 * */
 
+		set_src_in6_addr(pkt_dev);
+
 		if (!ipv6_addr_any(&pkt_dev->min_in6_daddr)) {
 			int i;
 
-- 
2.20.1