xnu-6153.11.26.tar.gz

[apple/xnu.git] / bsd / netinet / in.c

diff --git a/bsd/netinet/in.c b/bsd/netinet/in.c
index 5f464c32581ca93a7415dbfde0f22901051a1ecf..f51b22b4e984cb4f19c5db0ddef0b021074619b9 100644 (file)
--- a/bsd/netinet/in.c
+++ b/bsd/netinet/in.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2000-2016 Apple Inc. All rights reserved.
+ * Copyright (c) 2000-2019 Apple Inc. All rights reserved.
  *
  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
  *
@@ -77,6 +77,7 @@
 
 #include <kern/zalloc.h>
 #include <pexpert/pexpert.h>
+#include <os/log.h>
 
 #include <net/if.h>
 #include <net/if_types.h>
@@ -778,10 +779,6 @@ inctl_ifaddr(struct ifnet *ifp, struct in_ifaddr *ia, u_long cmd,
                        error = 0;
                }
                if (error != 0) {
-                       /* Reset the detaching flag */
-                       IFA_LOCK(&ia->ia_ifa);
-                       ia->ia_ifa.ifa_debug &= ~IFD_DETACHING;
-                       IFA_UNLOCK(&ia->ia_ifa);
                        break;
                }
 
@@ -1346,21 +1343,6 @@ in_control(struct socket *so, u_long cmd, caddr_t data, struct ifnet *ifp,
                        if (iap->ia_ifp == ifp &&
                            iap->ia_addr.sin_addr.s_addr ==
                            sa->sin_addr.s_addr) {
-                               /*
-                                * Avoid the race condition seen when two
-                                * threads process SIOCDIFADDR command
-                                * at the same time (radar 28942007)
-                                */
-                               if (cmd == SIOCDIFADDR) {
-                                       if (iap->ia_ifa.ifa_debug &
-                                           IFD_DETACHING) {
-                                               IFA_UNLOCK(&iap->ia_ifa);
-                                               continue;
-                                       } else {
-                                               iap->ia_ifa.ifa_debug |=
-                                                   IFD_DETACHING;
-                                       }
-                               }
                                ia = iap;
                                IFA_ADDREF_LOCKED(&iap->ia_ifa);
                                IFA_UNLOCK(&iap->ia_ifa);
@@ -1377,15 +1359,12 @@ in_control(struct socket *so, u_long cmd, caddr_t data, struct ifnet *ifp,
                                IFA_LOCK(&iap->ia_ifa);
                                if (iap->ia_addr.sin_family == AF_INET) {
                                        ia = iap;
+                                       IFA_ADDREF_LOCKED(&iap->ia_ifa);
                                        IFA_UNLOCK(&iap->ia_ifa);
                                        break;
                                }
                                IFA_UNLOCK(&iap->ia_ifa);
                        }
-                       /* take a reference on ia before releasing lock */
-                       if (ia != NULL) {
-                               IFA_ADDREF(&ia->ia_ifa);
-                       }
                        ifnet_lock_done(ifp);
                }
        }
@@ -1444,10 +1423,40 @@ in_control(struct socket *so, u_long cmd, caddr_t data, struct ifnet *ifp,
                        error = EINVAL;
                        goto done;
                }
-               if (cmd == SIOCDIFADDR && ia == NULL) {
-                       error = EADDRNOTAVAIL;
-                       goto done;
+               if (cmd == SIOCDIFADDR) {
+                       if (ia == NULL) {
+                               error = EADDRNOTAVAIL;
+                               goto done;
+                       }
+
+                       IFA_LOCK(&ia->ia_ifa);
+                       /*
+                        * Avoid the race condition seen when two
+                        * threads process SIOCDIFADDR command
+                        * at the same time.
+                        */
+                       while (ia->ia_ifa.ifa_debug & IFD_DETACHING) {
+                               os_log(OS_LOG_DEFAULT,
+                                   "Another thread is already attempting to "
+                                   "delete IPv4 address: %s on interface %s. "
+                                   "Go to sleep and check again after the operation is done",
+                                   inet_ntoa(sa->sin_addr), ia->ia_ifp->if_xname);
+                               ia->ia_ifa.ifa_del_waiters++;
+                               (void) msleep(ia->ia_ifa.ifa_del_wc, &ia->ia_ifa.ifa_lock, (PZERO - 1),
+                                   __func__, NULL);
+                               IFA_LOCK_ASSERT_HELD(&ia->ia_ifa);
+                       }
+
+                       if ((ia->ia_ifa.ifa_debug & IFD_ATTACHED) == 0) {
+                               error = EADDRNOTAVAIL;
+                               IFA_UNLOCK(&ia->ia_ifa);
+                               goto done;
+                       }
+
+                       ia->ia_ifa.ifa_debug |= IFD_DETACHING;
+                       IFA_UNLOCK(&ia->ia_ifa);
                }
+
        /* FALLTHROUGH */
        case SIOCSIFADDR:               /* struct ifreq */
        case SIOCSIFDSTADDR:            /* struct ifreq */
@@ -1543,8 +1552,18 @@ in_control(struct socket *so, u_long cmd, caddr_t data, struct ifnet *ifp,
                error = EOPNOTSUPP;
                break;
        }
+
 done:
        if (ia != NULL) {
+               if (cmd == SIOCDIFADDR) {
+                       IFA_LOCK(&ia->ia_ifa);
+                       ia->ia_ifa.ifa_debug &= ~IFD_DETACHING;
+                       if (ia->ia_ifa.ifa_del_waiters > 0) {
+                               ia->ia_ifa.ifa_del_waiters = 0;
+                               wakeup(ia->ia_ifa.ifa_del_wc);
+                       }
+                       IFA_UNLOCK(&ia->ia_ifa);
+               }
                IFA_REMREF(&ia->ia_ifa);
        }
        if (so_unlocked) {
@@ -2036,6 +2055,8 @@ in_ifaddr_alloc(int how)
                bzero(inifa, inifa_size);
                inifa->ia_ifa.ifa_free = in_ifaddr_free;
                inifa->ia_ifa.ifa_debug |= IFD_ALLOC;
+               inifa->ia_ifa.ifa_del_wc = &inifa->ia_ifa.ifa_debug;
+               inifa->ia_ifa.ifa_del_waiters = 0;
                ifa_lock_init(&inifa->ia_ifa);
                if (inifa_debug != 0) {
                        struct in_ifaddr_dbg *inifa_dbg =