From: Eric Dumazet <eric.dumazet@gmail.com>
To: Stephen Hemminger <stephen@networkplumber.org>
Cc: netdev <netdev@vger.kernel.org>
Subject: [PATCH iproute2] ss: small optim in tcp_show_info()
Date: Wed, 06 May 2015 11:33:23 -0700 [thread overview]
Message-ID: <1430937203.14545.62.camel@edumazet-glaptop2.roam.corp.google.com> (raw)
From: Eric Dumazet <edumazet@google.com>
Kernel can give us smaller tcp_info than our.
We copy the kernel provided structure and fill with 0
the remaining part.
Lets clear only the missing part to save some cycles, as we intend to
slightly increase tcp_info size in the future.
Signed-off-by: Eric Dumazet <edumazet@google.com>
---
diff --git a/misc/ss.c b/misc/ss.c
index 46dbb39..68961fc 100644
--- a/misc/ss.c
+++ b/misc/ss.c
@@ -1893,8 +1893,8 @@ static void tcp_show_info(const struct nlmsghdr *nlh, struct inet_diag_msg *r,
/* workaround for older kernels with less fields */
if (len < sizeof(*info)) {
info = alloca(sizeof(*info));
- memset(info, 0, sizeof(*info));
memcpy(info, RTA_DATA(tb[INET_DIAG_INFO]), len);
+ memset((char *)info + len, 0, sizeof(*info) - len);
} else
info = RTA_DATA(tb[INET_DIAG_INFO]);
next reply other threads:[~2015-05-06 18:33 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-05-06 18:33 Eric Dumazet [this message]
2015-05-11 16:16 ` [PATCH iproute2] ss: small optim in tcp_show_info() Stephen Hemminger
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