socket-util: Run the fallback when the kernel complains about the null buffer (#3541)

Calling recv with a NULL buffer returns EFAULT instead of EOPNOTSUPP on
older kernels (3.14).

Fixes #3407

Signed-off-by: Kai Ruhnau <kai.ruhnau@target-sg.com>

diff --git a/src/basic/socket-util.c b/src/basic/socket-util.c
index 86d6e3f6e1a609b020c51eded17bc7adbf766717..f47a8f04e0399c16233ebad5b9b8481681363e9c 100644 (file)
--- a/src/basic/socket-util.c
+++ b/src/basic/socket-util.c
@@ -991,7 +991,7 @@ ssize_t next_datagram_size_fd(int fd) {
 
         l = recv(fd, NULL, 0, MSG_PEEK|MSG_TRUNC);
         if (l < 0) {
 
         l = recv(fd, NULL, 0, MSG_PEEK|MSG_TRUNC);
         if (l < 0) {

-                if (errno == EOPNOTSUPP)
+                if (errno == EOPNOTSUPP || errno == EFAULT)

                         goto fallback;
 
                 return -errno;
                         goto fallback;
 
                 return -errno;