socket-util: introduce CMSG_SPACE_TIMEVAL/TIMESPEC macro to support additional 64bit timeval or timespec

Fixes #20482 and #20564.

src/basic/socket-util.h

@@ -277,6 +277,28 @@ static inline int getsockopt_int(int fd, int level, int optname, int *ret) {
 int socket_bind_to_ifname(int fd, const char *ifname);
 int socket_bind_to_ifindex(int fd, int ifindex);
 
+/* Define a 64bit version of timeval/timespec in any case, even on 32bit userspace. */
+struct timeval_large {
+        uint64_t tvl_sec, tvl_usec;
+};
+struct timespec_large {
+        uint64_t tvl_sec, tvl_nsec;
+};
+
+/* glibc duplicates timespec/timeval on certain 32bit archs, once in 32bit and once in 64bit.
+ * See __convert_scm_timestamps() in glibc souce code. Hence, we need additional buffer space for them
+ * to prevent from recvmsg_safe() returning -EXFULL. */
+#define CMSG_SPACE_TIMEVAL                                              \
+        ((sizeof(struct timeval) == sizeof(struct timeval_large)) ?     \
+         CMSG_SPACE(sizeof(struct timeval)) :                           \
+         CMSG_SPACE(sizeof(struct timeval)) +                           \
+         CMSG_SPACE(sizeof(struct timeval_large)))
+#define CMSG_SPACE_TIMESPEC                                             \
+        ((sizeof(struct timespec) == sizeof(struct timespec_large)) ?   \
+         CMSG_SPACE(sizeof(struct timespec)) :                          \
+         CMSG_SPACE(sizeof(struct timespec)) +                          \
+         CMSG_SPACE(sizeof(struct timespec_large)))
+
 ssize_t recvmsg_safe(int sockfd, struct msghdr *msg, int flags);
 
 int socket_get_family(int fd, int *ret);

src/journal/journald-server.c

@@ -1269,7 +1269,7 @@ int server_process_datagram(
          * identical to NAME_MAX. For now we use that, but this should be updated one day when the final
          * limit is known. */
         CMSG_BUFFER_TYPE(CMSG_SPACE(sizeof(struct ucred)) +
-                         CMSG_SPACE(sizeof(struct timeval)) +
+                         CMSG_SPACE_TIMEVAL +
                          CMSG_SPACE(sizeof(int)) + /* fd */
                          CMSG_SPACE(NAME_MAX) /* selinux label */) control;
 

src/libsystemd-network/icmp6-util.c

@@ -149,7 +149,7 @@ int icmp6_receive(int fd, void *buffer, size_t size, struct in6_addr *ret_dst,
                   triple_timestamp *ret_timestamp) {
 
         CMSG_BUFFER_TYPE(CMSG_SPACE(sizeof(int)) + /* ttl */
-                         CMSG_SPACE(sizeof(struct timeval))) control;
+                         CMSG_SPACE_TIMEVAL) control;
         struct iovec iov = {};
         union sockaddr_union sa = {};
         struct msghdr msg = {

src/timesync/timesyncd-manager.c

@@ -416,7 +416,7 @@ static int manager_receive_response(sd_event_source *source, int fd, uint32_t re
                 .iov_base = &ntpmsg,
                 .iov_len = sizeof(ntpmsg),
         };
-        CMSG_BUFFER_TYPE(CMSG_SPACE(sizeof(struct timespec))) control;
+        CMSG_BUFFER_TYPE(CMSG_SPACE_TIMESPEC) control;
         union sockaddr_union server_addr;
         struct msghdr msghdr = {
                 .msg_iov = &iov,