resolve: treat some icmp errors as disconnected

Fixes #9773.

diff --git a/src/basic/fd-util.h b/src/basic/fd-util.h
index 8adc959da8a14d2be92b239d105f8b15814794ae..00303a7e4548490b386f1a42acb11a49c3fb564a 100644 (file)
--- a/src/basic/fd-util.h
+++ b/src/basic/fd-util.h
@@ -78,8 +78,12 @@ int acquire_data_fd(const void *data, size_t size, unsigned flags);
 int fd_duplicate_data_fd(int fd);
 
 /* Hint: ENETUNREACH happens if we try to connect to "non-existing" special IP addresses, such as ::5 */
-#define ERRNO_IS_DISCONNECT(r) \
-        IN_SET(r, ENOTCONN, ECONNRESET, ECONNREFUSED, ECONNABORTED, EPIPE, ENETUNREACH)
+/* The kernel sends e.g., EHOSTUNREACH or ENONET to userspace in some ICMP error cases.
+ * See the icmp_err_convert[] in net/ipv4/icmp.c in the kernel sources */
+#define ERRNO_IS_DISCONNECT(r)                                          \
+        IN_SET(r,                                                       \
+               ENOTCONN, ECONNRESET, ECONNREFUSED, ECONNABORTED, EPIPE, \
+               ENETUNREACH, EHOSTUNREACH, ENOPROTOOPT, EHOSTDOWN, ENONET)
 
 /* Resource exhaustion, could be our fault or general system trouble */
 #define ERRNO_IS_RESOURCE(r) \