Messages in this thread | | | Date | Mon, 13 Jan 2020 04:51:36 -0800 | From | Jakub Kicinski <> | Subject | Re: [PATCH v2] pktgen: create packet use IPv6 source address between src6_min and src6_max. |
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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 <niu_xilei@163.com> > > 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; > +}
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