commit f2e98605612da20b0aea1d6c1de978f2a1456c06
from: Stefan Sperling <stsp@stsp.name>
date: Thu Oct 31 18:05:52 2024 UTC

fix error when flush arp/route run into deleted routing table entries

It is possible to get "no such process" (ESRCH) errors during flush
arp or flush route commands due to concurrent deletion of routing
table entries by another process.

This is no reason to stop trying to delete more routes, so do not
abort the loop in this case.

Also, make nsh print a more informative error message in this case,
rather than "no such process". Example of the new error message:

% No such route to delete: 100.64.1.2 fe:e1:ba:d0:8e:45 255.255.255.255 fe:e1:bb:d1:c4:b8 100.64.1.3

commit - 8c49d18a44147af1ab39ce950b96914db1bde50f
commit + f2e98605612da20b0aea1d6c1de978f2a1456c06
blob - 00017bf8a8f2051af1d1393e820c5bfc9a69e7d3
blob + 98febbd027c112d6992682db6bc022d91f222334
--- kroute.c
+++ kroute.c
@@ -74,6 +74,7 @@ void	 print_rtmsg(struct rt_msghdr *);
 void	 print_getmsg(struct rt_msghdr *, int);
 void	 pmsg_common(struct rt_msghdr *);
 void	 pmsg_addrs(char *, int);
+void	 print_addrs(char *, int);
 void	 bprintf(FILE *, int, u_char *);
 
 /*
@@ -201,6 +202,16 @@ flushroutes(int af, int af2)
 		rtm->rtm_seq = seqno;
 		rlen = write(s, next, rtm->rtm_msglen);
 		if (rlen < (int)rtm->rtm_msglen) {
+			if (errno == ESRCH) {
+				printf("%% No such route to delete:");
+				print_addrs((char *)rtm + rtm->rtm_hdrlen,
+				   rtm->rtm_addrs);
+				putchar('\n');
+				fflush(stdout);
+
+				seqno++;
+				continue;
+			}
 			printf("%% Unable to write to routing socket: %s\n",
 			    strerror(errno));
 			break;
@@ -517,22 +528,31 @@ pmsg_common(struct rt_msghdr *rtm)
 void
 pmsg_addrs(char	*cp, int addrs)
 {
-	struct sockaddr *sa;
-	int i;
-
 	if (addrs == 0)
 		return;
 	(void) printf("%% sockaddrs: ");
 	bprintf(stdout, addrs, addrnames);
+	(void) putchar('\n');
+	print_addrs(cp, addrs);
 	(void) putchar('\n');
+	(void) fflush(stdout);
+}
+
+void
+print_addrs(char *cp, int addrs)
+{
+	struct sockaddr *sa;
+	int i;
+
+	if (addrs == 0)
+		return;
+
 	for (i = 1; i; i <<= 1)
 		if (i & addrs) {
 			sa = (struct sockaddr *)cp;
 			(void) printf(" %s", routename(sa));
 			ADVANCE(cp, sa);
 		}
-	(void) putchar('\n');
-	(void) fflush(stdout);
 }
 
 void