diff options
author | rwatson <rwatson@FreeBSD.org> | 2009-08-25 20:21:16 +0000 |
---|---|---|
committer | rwatson <rwatson@FreeBSD.org> | 2009-08-25 20:21:16 +0000 |
commit | 8184e58b3aca79bbb4865b22468b7a7b74040fe2 (patch) | |
tree | 384648c2bcd21276b9a25adb5e452acabcf19a31 /sys/net/if.c | |
parent | 968343b40035a3f4983f273ce3ce2b2b7b4e37f1 (diff) | |
download | FreeBSD-src-8184e58b3aca79bbb4865b22468b7a7b74040fe2.zip FreeBSD-src-8184e58b3aca79bbb4865b22468b7a7b74040fe2.tar.gz |
Break out allocation of new ifindex values from if_alloc() and if_vmove(),
and centralize in a single function ifindex_alloc(). Assert the
IFNET_WLOCK, and add missing IFNET_WLOCK in if_alloc(). This does not
close all known races in this code.
Reviewed by: bz
MFC after: 3 days
Diffstat (limited to 'sys/net/if.c')
-rw-r--r-- | sys/net/if.c | 76 |
1 files changed, 42 insertions, 34 deletions
diff --git a/sys/net/if.c b/sys/net/if.c index 6433168..f2f1c4f 100644 --- a/sys/net/if.c +++ b/sys/net/if.c @@ -223,6 +223,37 @@ ifnet_byindex_ref(u_short idx) return (ifp); } +/* + * Allocate an ifindex array entry; return 0 on success or an error on + * failure. + */ +static int +ifindex_alloc(u_short *idxp) +{ + u_short idx; + + IFNET_WLOCK_ASSERT(); + + /* + * Try to find an empty slot below if_index. If we fail, take the + * next slot. + */ + for (idx = 1; idx <= V_if_index; idx++) { + if (ifnet_byindex_locked(idx) == NULL) + break; + } + + /* Catch if_index overflow. */ + if (idx < 1) + return (ENOSPC); + if (idx > V_if_index) + V_if_index = idx; + if (V_if_index >= V_if_indexlim) + if_grow(); + *idxp = idx; + return (0); +} + static void ifnet_setbyindex_locked(u_short idx, struct ifnet *ifp) { @@ -335,32 +366,19 @@ struct ifnet * if_alloc(u_char type) { struct ifnet *ifp; + u_short idx; ifp = malloc(sizeof(struct ifnet), M_IFNET, M_WAITOK|M_ZERO); - - /* - * Try to find an empty slot below if_index. If we fail, take - * the next slot. - * - * XXX: should be locked! - */ - for (ifp->if_index = 1; ifp->if_index <= V_if_index; ifp->if_index++) { - if (ifnet_byindex(ifp->if_index) == NULL) - break; - } - /* Catch if_index overflow. */ - if (ifp->if_index < 1) { + IFNET_WLOCK(); + if (ifindex_alloc(&idx) != 0) { + IFNET_WUNLOCK(); free(ifp, M_IFNET); return (NULL); } - if (ifp->if_index > V_if_index) - V_if_index = ifp->if_index; - if (V_if_index >= V_if_indexlim) - if_grow(); - + IFNET_WUNLOCK(); + ifp->if_index = idx; ifp->if_type = type; ifp->if_alloctype = type; - if (if_com_alloc[type] != NULL) { ifp->if_l2com = if_com_alloc[type](type, ifp); if (ifp->if_l2com == NULL) { @@ -882,6 +900,7 @@ if_detach_internal(struct ifnet *ifp, int vmove) void if_vmove(struct ifnet *ifp, struct vnet *new_vnet) { + u_short idx; /* * Detach from current vnet, but preserve LLADDR info, do not @@ -907,23 +926,12 @@ if_vmove(struct ifnet *ifp, struct vnet *new_vnet) */ CURVNET_SET_QUIET(new_vnet); - /* - * Try to find an empty slot below if_index. If we fail, take - * the next slot. - */ IFNET_WLOCK(); - for (ifp->if_index = 1; ifp->if_index <= V_if_index; ifp->if_index++) { - if (ifnet_byindex_locked(ifp->if_index) == NULL) - break; - } - /* Catch if_index overflow. */ - if (ifp->if_index < 1) + if (ifindex_alloc(&idx) != 0) { + IFNET_WUNLOCK(); panic("if_index overflow"); - - if (ifp->if_index > V_if_index) - V_if_index = ifp->if_index; - if (V_if_index >= V_if_indexlim) - if_grow(); + } + ifp->if_index = idx; ifnet_setbyindex_locked(ifp->if_index, ifp); IFNET_WUNLOCK(); |