From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: [PATCH v2 iproute2] get_rate: detect 32bit overflows Date: Sun, 02 Jun 2013 14:36:48 -0700 Message-ID: <1370209008.24311.91.camel@edumazet-glaptop> References: <1370199083.24311.43.camel@edumazet-glaptop> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: netdev To: Stephen Hemminger Return-path: Received: from mail-pb0-f44.google.com ([209.85.160.44]:57555 "EHLO mail-pb0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752943Ab3FBVgu (ORCPT ); Sun, 2 Jun 2013 17:36:50 -0400 Received: by mail-pb0-f44.google.com with SMTP id wz12so4771562pbc.31 for ; Sun, 02 Jun 2013 14:36:49 -0700 (PDT) In-Reply-To: <1370199083.24311.43.camel@edumazet-glaptop> Sender: netdev-owner@vger.kernel.org List-ID: Current rate limit is 34.359.738.360 bit per second, and unfortunately 40Gbps links are above it. overflows in get_rate() are currently not detected, and some users are confused. Let's detect this and complain. Note that some qdisc are ready to get extended range, but this will need additional attributes and new iproute2 Signed-off-by: Eric Dumazet --- v2: divide by 8 only at the right time tc/tc_util.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/tc/tc_util.c b/tc/tc_util.c index 8e62a01..8ca9d4e 100644 --- a/tc/tc_util.c +++ b/tc/tc_util.c @@ -146,21 +146,26 @@ static const struct rate_suffix { int get_rate(unsigned *rate, const char *str) { char *p; - double bps = strtod(str, &p); + long long bps = strtoll(str, &p, 0); const struct rate_suffix *s; if (p == str) return -1; if (*p == '\0') { - *rate = bps / 8.; /* assume bits/sec */ +common: + bps /= 8; /* -> bytes per second */ + *rate = bps; + /* detect if an overflow happened */ + if (*rate != bps) + return -1; return 0; } for (s = suffixes; s->name; ++s) { if (strcasecmp(s->name, p) == 0) { - *rate = (bps * s->scale) / 8.; - return 0; + bps *= s->scale; + goto common; } }