netdev - Re: [PATCH 1/1] net: Add SO_REUSEPORT_LISTEN

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <1458859788.6473.2.camel@edumazet-glaptop3.roam.corp.google.com>
Date:	Thu, 24 Mar 2016 15:49:48 -0700
From:	Eric Dumazet <eric.dumazet@...il.com>
To:	Yann Ylavic <ylavic.dev@...il.com>
Cc:	Linux Kernel Network Developers <netdev@...r.kernel.org>,
	Tom Herbert <tom@...bertland.com>, Willy Tarreau <w@....eu>,
	Tolga Ceylan <tolga.ceylan@...il.com>,
	Craig Gallek <cgallek@...gle.com>,
	Josh Snyder <josh@...e406.com>,
	Aaron Conole <aconole@...heb.org>,
	"David S. Miller" <davem@...emloft.net>,
	Daniel Borkmann <daniel@...earbox.net>
Subject: Re: [PATCH 1/1] net: Add SO_REUSEPORT_LISTEN_OFF socket option as
 drain mode

On Thu, 2016-03-24 at 23:40 +0100, Yann Ylavic wrote:

> FWIW, I find:
> 
>     const struct bpf_insn prog[] = {
>         /* BPF_MOV64_REG(BPF_REG_6, BPF_REG_1) */
>         { BPF_ALU64 | BPF_MOV | BPF_X, BPF_REG_6, BPF_REG_1, 0, 0 },
>         /* BPF_LD_ABS(BPF_W, 0) R0 = (uint32_t)skb[0] */
>         { BPF_LD | BPF_ABS | BPF_W, 0, 0, 0, 0 },
>         /* BPF_ALU64_IMM(BPF_MOD, BPF_REG_0, mod) */
>         { BPF_ALU64 | BPF_MOD | BPF_K, BPF_REG_0, 0, 0, mod },
>         /* BPF_EXIT_INSN() */
>         { BPF_JMP | BPF_EXIT, 0, 0, 0, 0 }
>     };
> (and all the way to make it run)
> 
> something quite unintuitive from a web server developper perspective,
> simply to make SO_REUSEPORT work with forked TCP listeners (probably
> as it should out of the box)...


That is why EBPF has LLVM backend.

Basically you can write your "BPF" program in C, and let llvm convert it
into EBPF.

Sure, you still can write BPF manually, as you could write HTTPS server
in assembly.