From: Jan Engelhardt <jengelh@inai.de>
Date: Mon, 12 Oct 2020 13:55:55 +0000 (+0200)
Subject: ip: add error reporting when RTM_GETNSID failed
X-Git-Tag: v5.9.0~1
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=0ca1312c208a6b4260898dccc59030a85c131b27;p=thirdparty%2Fiproute2.git

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 not helpful for the user however. This patch reworks
the error handling.

Before:

rtest:/ # ip a
2: host0@if4: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
request send failed: Operation not supported
    link/ether 46:3f:2d:88:3d:db brd ff:ff:ff:ff:ff:ffrtest:/ #

Afterwards:

rtest:/ # ip a
2: host0@if4: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
rtnl_send(RTM_GETNSID): Operation not supported. Continuing anyway.
    link/ether 46:3f:2d:88:3d:db brd ff:ff:ff:ff:ff:ff link-netnsid 0
    inet 192.168.72.147/28 brd 192.168.72.159 scope global host0
       valid_lft forever preferred_lft forever
    inet6 fe80::443f:2dff:fe88:3ddb/64 scope link
       valid_lft forever preferred_lft forever

Signed-off-by: Jan Engelhardt <jengelh@inai.de>
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
---

diff --git a/ip/ipnetns.c b/ip/ipnetns.c
index 46cc235b7..14e8e087e 100644
--- a/ip/ipnetns.c
+++ b/ip/ipnetns.c
@@ -75,9 +75,12 @@ static int ipnetns_have_nsid(void)
 	};
 	int fd;
 
-	if (have_rtnl_getnsid < 0) {
+	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 +88,12 @@ 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);