2020-01-13 11:38:50

by Niu Xilei

[permalink] [raw]
Subject: [PATCH v2] pktgen: create packet use IPv6 source address between src6_min and src6_max.

Pktgen can use only one IPv6 source address from output device, or src6 command
setting. In pressure test we need create lots of session more than 65536.If
IPSRC_RND flag is set, generate random source address between src6_min and src6_max.

Signed-off-by: Niu Xilei <[email protected]>

Changes since v1:
- only create IPv6 source address over least significant 64 bit range
---
net/core/pktgen.c | 90 +++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 90 insertions(+)

diff --git a/net/core/pktgen.c b/net/core/pktgen.c
index 294bfcf0ce0e..33435ae0ba68 100644
--- a/net/core/pktgen.c
+++ b/net/core/pktgen.c
@@ -1355,6 +1355,49 @@ 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);
+
+ 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);
+
+ if (debug)
+ pr_debug("dst6_max set to: %s\n", buf);
+
+ i += len;
+ sprintf(pg_result, "OK: dst6_max=%s", buf);
+ return count;
+ }
if (!strcmp(name, "src6")) {
len = strn_len(&user_buffer[i], sizeof(buf) - 1);
if (len < 0)
@@ -2286,6 +2329,51 @@ 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 inline void set_src_in6_addr(struct pktgen_dev *pkt_dev)
+{
+ __be64 min6_h, min6_l, max6_h, max6_l, addr_l, *t;
+ u64 min6, max6, rand, i;
+ struct in6_addr addr6;
+
+ memcpy(&min6_h, pkt_dev->min_in6_saddr.s6_addr, 8);
+ memcpy(&min6_l, pkt_dev->min_in6_saddr.s6_addr + 8, 8);
+ memcpy(&max6_h, pkt_dev->max_in6_saddr.s6_addr, 8);
+ memcpy(&max6_l, pkt_dev->max_in6_saddr.s6_addr + 8, 8);
+
+ /* only generate source address in least significant 64 bits range
+ * most significant 64 bits must be equal
+ */
+ if (max6_h != min6_h)
+ return;
+
+ addr6 = pkt_dev->min_in6_saddr;
+ t = (__be64 *)addr6.s6_addr + 1;
+ min6 = be64_to_cpu(min6_l);
+ max6 = be64_to_cpu(max6_l);
+
+ if (min6 < max6) {
+ 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 +2542,8 @@ 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


2020-01-13 12:59:36

by Jakub Kicinski

[permalink] [raw]
Subject: Re: [PATCH v2] pktgen: create packet use IPv6 source address between src6_min and src6_max.

The subject line could use some rewording, I think.

On Mon, 13 Jan 2020 19:21:02 +0800, Niu Xilei wrote:
> Pktgen can use only one IPv6 source address from output device, or src6 command
> setting. In pressure test we need create lots of session more than 65536.If
> IPSRC_RND flag is set, generate random source address between src6_min and src6_max.
>
> Signed-off-by: Niu Xilei <[email protected]>
>
> Changes since v1:
> - only create IPv6 source address over least significant 64 bit range

> +/* generate ipv6 source addr */
> +static inline void set_src_in6_addr(struct pktgen_dev *pkt_dev)

Please just use "static" instead of "static inline". The compiler will
be clever enough to decide the inlining.

> +{
> + __be64 min6_h, min6_l, max6_h, max6_l, addr_l, *t;
> + u64 min6, max6, rand, i;
> + struct in6_addr addr6;
> +
> + memcpy(&min6_h, pkt_dev->min_in6_saddr.s6_addr, 8);
> + memcpy(&min6_l, pkt_dev->min_in6_saddr.s6_addr + 8, 8);
> + memcpy(&max6_h, pkt_dev->max_in6_saddr.s6_addr, 8);
> + memcpy(&max6_l, pkt_dev->max_in6_saddr.s6_addr + 8, 8);
> +
> + /* only generate source address in least significant 64 bits range
> + * most significant 64 bits must be equal
> + */
> + if (max6_h != min6_h)
> + return;
> +
> + addr6 = pkt_dev->min_in6_saddr;
> + t = (__be64 *)addr6.s6_addr + 1;
> + min6 = be64_to_cpu(min6_l);
> + max6 = be64_to_cpu(max6_l);
> +
> + if (min6 < max6) {

Since this code is executed on every packet, would it be possible to
pre-compute the decision if the IPv6 address is to be generated or not?
We have 4 memcpy()s and 2 byte swaps, and the conditions never change,
so it could be computed at setup time, right?

> + 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;
> +}