78 lines
3.0 KiB
Diff
78 lines
3.0 KiB
Diff
From 86ed08936d49e2c81ef49dfbd02aca1c74d0c098 Mon Sep 17 00:00:00 2001
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From: lac-0073 <61903197+lac-0073@users.noreply.github.com>
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Date: Mon, 26 Oct 2020 09:45:42 +0800
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Subject: [PATCH] arpping: make update neighbours work again
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The arping is using inconsistent sender_ip_addr and target_ip_addr in
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messages. This causes the client receiving the arp message not to update
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the arp table entries.
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The specific performance is as follows:
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There is a machine 2 with IP 10.20.30.3 configured on eth0:0 that is in the
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same IP subnet as eth0. This IP was originally used on another machine 1,
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and th IP needs to be changed back to the machine 1. When using the arping
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command to announce what ethernet address has IP 10.20.30.3, the arp table
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on machine 3 is not updated.
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Machine 3 original arp table:
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10.20.30.3 machine 2 eth0:0 00:00:00:00:00:02
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10.20.30.2 machine 2 eth0 00:00:00:00:00:02
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10.20.30.1 machine 1 eth0 00:00:00:00:00:01
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Create interface eth0:0 on machine 1, and use the arping command to send arp
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packets. Expected outcome on machine 3:
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10.20.30.3 machine 1 eth0:0 00:00:00:00:00:01
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10.20.30.2 machine 2 eth0 00:00:00:00:00:02
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10.20.30.1 machine 1 eth0 00:00:00:00:00:01
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Actual results on machine 3:
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10.20.30.3 machine 2 eth0:0 00:00:00:00:00:02
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10.20.30.2 machine 2 eth0 00:00:00:00:00:02
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10.20.30.1 machine 1 eth0 00:00:00:00:00:01
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Fixes: https://github.com/iputils/iputils/issues/298
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Fixes: 68f12fc4a0dbef4ae4c404da24040d22c5a14339
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Signed-off-by: Aichun Li <liaichun@huawei.com>
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---
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arping.c | 16 +++++++++-------
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1 file changed, 9 insertions(+), 7 deletions(-)
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diff --git a/arping.c b/arping.c
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index a002786..53fdbb4 100644
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--- a/arping.c
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+++ b/arping.c
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@@ -968,7 +968,7 @@ int main(int argc, char **argv)
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}
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memset(&saddr, 0, sizeof(saddr));
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saddr.sin_family = AF_INET;
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- if (!ctl.unsolicited && (ctl.source || ctl.gsrc.s_addr)) {
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+ if (ctl.source || ctl.gsrc.s_addr) {
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saddr.sin_addr = ctl.gsrc;
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if (bind(probe_fd, (struct sockaddr *)&saddr, sizeof(saddr)) == -1)
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error(2, errno, "bind");
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@@ -979,12 +979,14 @@ int main(int argc, char **argv)
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saddr.sin_port = htons(1025);
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saddr.sin_addr = ctl.gdst;
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- if (setsockopt(probe_fd, SOL_SOCKET, SO_DONTROUTE, (char *)&on, sizeof(on)) == -1)
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- error(0, errno, _("WARNING: setsockopt(SO_DONTROUTE)"));
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- if (connect(probe_fd, (struct sockaddr *)&saddr, sizeof(saddr)) == -1)
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- error(2, errno, "connect");
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- if (getsockname(probe_fd, (struct sockaddr *)&saddr, &alen) == -1)
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- error(2, errno, "getsockname");
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+ if (!ctl.unsolicited) {
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+ if (setsockopt(probe_fd, SOL_SOCKET, SO_DONTROUTE, (char *)&on, sizeof(on)) == -1)
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+ error(0, errno, _("WARNING: setsockopt(SO_DONTROUTE)"));
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+ if (connect(probe_fd, (struct sockaddr *)&saddr, sizeof(saddr)) == -1)
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+ error(2, errno, "connect");
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+ if (getsockname(probe_fd, (struct sockaddr *)&saddr, &alen) == -1)
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+ error(2, errno, "getsockname");
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+ }
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ctl.gsrc = saddr.sin_addr;
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}
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close(probe_fd);
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