[systemd-devel] [PATCH] manager: use CMSG macros

[Shawn Landden]

---
 src/core/manager.c | 29 +++++++++++++++++++++--------
 1 file changed, 21 insertions(+), 8 deletions(-)

diff --git a/src/core/manager.c b/src/core/manager.c
index 634b141..74fb52d 100644
--- a/src/core/manager.c
+++ b/src/core/manager.c
@@ -1275,9 +1275,10 @@ static int manager_dispatch_notify_fd(sd_event_source *source, int fd, uint32_t
                 };
 
                 union {
-                        struct cmsghdr cmsghdr;
+                        struct msghdr msghdr;
                         uint8_t buf[CMSG_SPACE(sizeof(struct ucred))];
                 } control = {};
+                struct cmsghdr *cmsghdr;
 
                 struct msghdr msghdr = {
                         .msg_iov = &iovec,
@@ -1285,7 +1286,7 @@ static int manager_dispatch_notify_fd(sd_event_source *source, int fd, uint32_t
                         .msg_control = &control,
                         .msg_controllen = sizeof(control),
                 };
-                struct ucred *ucred;
+                struct ucred *ucred = NULL;
                 Unit *u;
                 _cleanup_strv_free_ char **tags = NULL;
 
@@ -1300,15 +1301,27 @@ static int manager_dispatch_notify_fd(sd_event_source *source, int fd, uint32_t
                         return -errno;
                 }
 
-                if (msghdr.msg_controllen < CMSG_LEN(sizeof(struct ucred)) ||
-                    control.cmsghdr.cmsg_level != SOL_SOCKET ||
-                    control.cmsghdr.cmsg_type != SCM_CREDENTIALS ||
-                    control.cmsghdr.cmsg_len != CMSG_LEN(sizeof(struct ucred))) {
-                        log_warning("Received notify message without credentials. Ignoring.");
+                if (msghdr.msg_controllen < CMSG_LEN(sizeof(struct cmsghdr))) {
+                        log_warning("sd_notify ancilliary message too short.");
                         continue;
                 }
 
-                ucred = (struct ucred*) CMSG_DATA(&control.cmsghdr);
+                cmsghdr = CMSG_FIRSTHDR(&control.msghdr);
+                do {
+                        if (cmsghdr->cmsg_level == SOL_SOCKET &&
+                            cmsghdr->cmsg_type == SCM_CREDENTIALS &&
+                            cmsghdr->cmsg_len == CMSG_LEN(sizeof(struct ucred)))
+                                ucred = (struct ucred*) CMSG_DATA(cmsghdr);
+                        else {
+                                log_warning("Unrecognized sd_notify ancilliary message. Ignoring");
+                                continue;
+                        }
+                } while ((cmsghdr = CMSG_NXTHDR(&control.msghdr, cmsghdr)));
+
+                if (!ucred) {
+                        log_warning("Received notify message without credentials. Ignoring.");
+                        continue;
+                }
 
                 u = hashmap_get(m->watch_pids, LONG_TO_PTR(ucred->pid));
                 if (!u) {
-- 
1.8.5.2.297.g3e57c29