lxc_af_unix_rcv_credential to report rcvd length

to have better error reporting done by caller.

Signed-off-by: Daniel Lezcano <dlezcano@fr.ibm.com>
Signed-off-by: Michel Normand <normand@fr.ibm.com>

diff --git a/src/lxc/af_unix.c b/src/lxc/af_unix.c
index 79f64ae3fbcec73f106179c7def99c0fa5f5d154..ad3e94ca8b6a3b682f85c1237298f4365eeec039 100644 (file)
--- a/src/lxc/af_unix.c
+++ b/src/lxc/af_unix.c
@@ -23,11 +23,15 @@
 #include <string.h>
 #include <unistd.h>
 #include <fcntl.h>
+#include <errno.h>
 #define __USE_GNU
 #include <sys/socket.h>
 #undef __USE_GNU
 #include <sys/un.h>
 
+#include "log.h"
+
+lxc_log_define(lxc_af_unix, lxc);
 
 int lxc_af_unix_open(const char *path, int type, int flags)
 {
@@ -229,14 +233,14 @@ int lxc_af_unix_rcv_credential(int fd, void *data, size_t size)
 
         cmsg = CMSG_FIRSTHDR(&msg);
 
-       ret = -1;
-
         if (cmsg && cmsg->cmsg_len == CMSG_LEN(sizeof(struct ucred)) &&
             cmsg->cmsg_level == SOL_SOCKET &&
             cmsg->cmsg_type == SCM_CREDENTIALS) {
                 cred = *((struct ucred *) CMSG_DATA(cmsg));
-               if (cred.uid == getuid() && cred.gid == getgid())
-                       ret = 0;
+               if (cred.uid != getuid() || cred.gid != getgid()) {
+                       INFO("message denied for '%d/%d'", cred.uid, cred.gid);
+                       return -EPERM;
+               }
         }
 out:
         return ret;

diff --git a/src/lxc/start.c b/src/lxc/start.c
index 055d381f644644a24af763b341986de1a05135b6..28ce88c54a7eed782752ea16cc06be696829858e 100644 (file)
--- a/src/lxc/start.c
+++ b/src/lxc/start.c
@@ -200,8 +200,21 @@ static int ttyservice_handler(int fd, void *data,
                goto out_close;
        }
 
-       if (lxc_af_unix_rcv_credential(conn, &ttynum, sizeof(ttynum)))
+       ret = lxc_af_unix_rcv_credential(conn, &ttynum, sizeof(ttynum));
+       if (ret < 0) {
+               SYSERROR("failed to receive data on tty socket");
                goto out_close;
+       }
+
+       if (!ret) {
+               DEBUG("peer has disconnected");
+               goto out_close;
+       }
+
+       if (ret != sizeof(ttynum)) {
+               WARN("partial request, ignored");
+               goto out_close;
+       }
 
        if (ttynum > 0) {
                if (ttynum > tty_info->nbtty)