Pktgen can use only one IPv6 source address from output device, or src6 command
setting. When in pressure test need create lots of session more than 65536.
If IPSRC_RND flag is use random address between src6_min and src6_max.
The GCC generates code that calls functions in the libgcc library to implement
the / and % operations with 128-bit operands on 64-bit CPUs. So kernel need
implement the function to do / and % operation.
Signed-off-by: Niu Xilei <[email protected]>
---
net/core/pktgen.c | 183 ++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 183 insertions(+)
diff --git a/net/core/pktgen.c b/net/core/pktgen.c
index 294bfcf0ce0e..b07ab5984fa8 100644
--- a/net/core/pktgen.c
+++ b/net/core/pktgen.c
@@ -254,6 +254,111 @@ struct flow_state {
/* flow flag bits */
#define F_INIT (1<<0) /* flow has been initialized */
+#ifdef CONFIG_ARCH_SUPPORTS_INT128
+
+__extension__ typedef unsigned __int128 u128;
+
+/* Kernel not implement __int128's divide and modulo operator. Implement these
+ * operation use shift-subtract division algorithm adpater from
+ * https://chromium.googlesource.com/chromium/src/third_party/+/master/abseil-cpp/absl/numeric/int128.cc */
+
+/* find first bit set of u128 */
+static inline int fls128(u128 n)
+{
+ u64 hi = n >> 64;
+
+ if (hi)
+ return fls64(hi) + 64;
+
+ return fls64((__u64)n);
+}
+
+/**
+ * div128_u128 - unsigned 128bit int divide with unsigned 128bit int divisor
+ * @dividend: 128bit dividend
+ * @divisor: 128bit divisor
+ * @remainder: 128bit remainder
+ * @return: 128bit quotient
+ */
+u128 div128_u128(u128 dividend, u128 divisor, u128 *remainder)
+{
+ int i;
+ int shift;
+ u128 quotient = 0;
+ u128 denominator = divisor;
+
+ if (divisor > dividend) {
+ *remainder = dividend;
+ return 0;
+ }
+ if (divisor == dividend) {
+ *remainder = 0;
+ return 1;
+ }
+
+ /* Left aligns the MSB of the dividend and the dividend. */
+ shift = fls128(dividend) - fls128(denominator);
+ denominator <<= shift;
+ /* Uses shift-subtract algorithm to divide dividend by denominator. The
+ * remainder will be left in dividend. */
+ for (i = 0; i <= shift; ++i) {
+ quotient <<= 1;
+ if (dividend >= denominator) {
+ dividend -= denominator;
+ quotient |= 1;
+ }
+ denominator >>= 1;
+ }
+ *remainder = dividend;
+ return quotient;
+}
+
+#ifdef __LITTLE_ENDIAN
+
+static inline u128 be128_to_cpu(u128 net128)
+{
+#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
+ u64 *pnet = (u64 *)&net128;
+
+ return (((__force u128)swab64(pnet[0]) << 64) |
+ (__force u128)swab64(pnet[1]));
+#else
+
+ u32 *pnet = (u32 *)&net128;
+
+ return (((__force u128)swap32(pnet[0])) << 96 |
+ ((__force u128)swap32(pnet[1])) << 64 |
+ ((__force u128)swap32(pnet[2])) << 32 |
+ (__force u128)swap32(pnet[3]));
+
+#endif
+}
+
+static inline u128 cpu_to_be128(u128 host128)
+{
+#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
+ u64 *phost = (u64 *)&host128;
+
+ return (((__force u128)swab64(phost[0])) << 64 |
+ (__force u128)swab64(phost[1]));
+#else
+ u32 *phost = (u32 *)&host128;
+
+ return (((__force u128)swap32(phost[0])) << 96 |
+ ((__force u128)swap32(phost[1])) << 64 |
+ ((__force u128)swap32(phost[2])) << 32 |
+ (__force u128)swap32(phost[3]));
+#endif
+}
+
+#else /* !__LITTLE_ENDIAN */
+
+#define be128_to_cpu(x) (x)
+#define cpu_to_be128(x) (x)
+
+#endif /* __LITTLE_ENDIAN */
+#endif /* CONFIG_ARCH_SUPPORTS_INT128 */
+
struct pktgen_dev {
/*
* Try to keep frequent/infrequent used vars. separated.
@@ -1355,6 +1460,49 @@ 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 +2434,38 @@ 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;
}
+/* create ipv6 source addr, random generator or iterator between the range */
+static inline void set_src_in6_addr(struct pktgen_dev *pkt_dev)
+{
+ u128 t;
+ u128 imn6, imx6;
+
+ if (!ipv6_addr_any(&pkt_dev->min_in6_saddr)) {
+#ifdef CONFIG_ARCH_SUPPORTS_INT128
+ imn6 = be128_to_cpu(*(u128 *)pkt_dev->min_in6_saddr.s6_addr);
+ imx6 = be128_to_cpu(*(u128 *)pkt_dev->max_in6_saddr.s6_addr);
+ if (imn6 < imx6) {
+ if (pkt_dev->flags & F_IPSRC_RND) {
+ do {
+ prandom_bytes(&t, sizeof(t));
+ /*t = t % range */
+ div128_u128(t, imx6 - imn6, &t);
+ t = imn6 + t;
+ } while (ipv6_addr_loopback((struct in6_addr *)&t) ||
+ ipv6_addr_v4mapped((struct in6_addr *)&t) ||
+ ipv6_addr_is_multicast((struct in6_addr *)(&t)));
+ } else {
+ t = be128_to_cpu(*(u128 *)pkt_dev->cur_in6_saddr.s6_addr);
+ t++;
+ if (t > imx6)
+ t = imn6;
+ }
+ t = cpu_to_be128(t);
+ pkt_dev->cur_in6_saddr = *(struct in6_addr *)&t;
+ }
+#endif
+ }
+}
/* Increment/randomize headers according to flags and current values
* for IP src/dest, UDP src/dst port, MAC-Addr src/dst
*/
@@ -2293,6 +2473,7 @@ static void mod_cur_headers(struct pktgen_dev *pkt_dev)
{
__u32 imn;
__u32 imx;
+
int flow = 0;
if (pkt_dev->cflows)
@@ -2454,6 +2635,8 @@ 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
On Fri, 10 Jan 2020 18:28:42 +0800
Niu Xilei <[email protected]> wrote:
> +/* Kernel not implement __int128's divide and modulo operator. Implement these
> + * operation use shift-subtract division algorithm adpater from
> + * https://chromium.googlesource.com/chromium/src/third_party/+/master/abseil-cpp/absl/numeric/int128.cc */
Some rewording of this comment is necessary to fix the English grammar.
And Linux style is not to put comment closing on same line.
Something like:
/* The Linux kernel does not implement 128 bit divide and modulus operations.
* Implement these operations using shift-subtract division algorithm
* from Chrome.
* https://chromium.googlesource.com/chromium/src/third_party/+/master/abseil-cpp/absl/numeric/int128.cc
*/
Also, the int128 code you referenced is Apache licensed (not GPL-v2 like kernel).
For div128_u128 the function should be static to avoid name conflicts.
The declarations need to be in reverse christmas tree order as well.
It does seem a bit like overkill since doing source address over a 64 bit
range should be more than enough for any test in this decade.
From: Niu Xilei <[email protected]>
Date: Fri, 10 Jan 2020 18:28:42 +0800
> --- a/net/core/pktgen.c
> +++ b/net/core/pktgen.c
> @@ -254,6 +254,111 @@ struct flow_state {
> /* flow flag bits */
> #define F_INIT (1<<0) /* flow has been initialized */
>
> +#ifdef CONFIG_ARCH_SUPPORTS_INT128
> +
> +__extension__ typedef unsigned __int128 u128;
> +
This does not belong in pktgen.c but rather in a generic kernel header, and such
facilities should be posted for general review on lkml.