On Tuesday 2020-09-22 02:22, Stephen Hemminger wrote:
>Jan Engelhardt <jeng...@inai.de> wrote:
>
>> `ip addr` when run under qemu-user-riscv64, fails. This likely is
>> due to qemu-5.1 not doing translation of RTM_GETNSID calls.
>>
>> 2: host0@if5: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state
>> UP group default qlen 1000
>> link/ether 5a:44:da:1a:c4:0b brd ff:ff:ff:ff:ff:ff
>> request send failed: Operation not supported
>>
>> Treat the situation similar to an absence of procfs.
>>
>> Signed-off-by: Jan Engelhardt <jeng...@inai.de>
>
>Not a good idea to hide a platform bug in ip command.
>When you do this, you risk creating all sorts of issues for people that
>run ip commands in container environments where the send is rejected (perhaps
>by SELinux)
>and then things go off into a different failure.
In the very same function you do
fd = open("/proc/self/ns/net", O_RDONLY);
which equally hides a potential platform bug (namely, forgetting to
mount /proc in a chroot, or in case SELinux was improperly set-up).
Why is this measured two different ways?
>From 4222d059c910136f5e2b5c6de96ddaf06828c1d5 Mon Sep 17 00:00:00 2001
From: Jan Engelhardt <jeng...@inai.de>
Date: Tue, 22 Sep 2020 01:41:50 +0200
Subject: [PATCH] ip: add error reporting when RTM_GETNSID failed
`ip addr` when run under qemu-user-riscv64, fails. This likely is
due to qemu-5.1 not doing translation of RTM_GETNSID calls. Aborting
ip completely is the wrong response however. This patch reworks the
error handling.
2: host0@if5: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP
group default qlen 1000
link/ether 5a:44:da:1a:c4:0b brd ff:ff:ff:ff:ff:ff
request send failed: Operation not supported
Signed-off-by: Jan Engelhardt <jeng...@inai.de>
---
ip/ipnetns.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/ip/ipnetns.c b/ip/ipnetns.c
index 46cc235b..e7a45653 100644
--- a/ip/ipnetns.c
+++ b/ip/ipnetns.c
@@ -78,6 +78,8 @@ static int ipnetns_have_nsid(void)
if (have_rtnl_getnsid < 0) {
fd = open("/proc/self/ns/net", O_RDONLY);
if (fd < 0) {
+ fprintf(stderr, "/proc/self/ns/net: %s. "
+ "Continuing anyway.\n", strerror(errno));
have_rtnl_getnsid = 0;
return 0;
}
@@ -85,8 +87,11 @@ static int ipnetns_have_nsid(void)
addattr32(&req.n, 1024, NETNSA_FD, fd);
if (rtnl_send(&rth, &req.n, req.n.nlmsg_len) < 0) {
- perror("request send failed");
- exit(1);
+ fprintf(stderr, "rtnl_send(RTM_GETNSID): %s. "
+ "Continuing anyway.\n", strerror(errno));
+ have_rtnl_getnsid = 0;
+ close(fd);
+ return 0;
}
rtnl_listen(&rth, ipnetns_accept_msg, NULL);
close(fd);
--
2.28.0
