Tighten input checking in inp_join_group():

* Don't try to use the source address, when its family is unspecified.
 * If we get a join without a source, on an existing inclusive
   mode group, this is an error, as it would change the filter mode.

Fix a problem with the handling of in_mfilter for new memberships:
 * Do not rely on imf being NULL; it is explicitly initialized to a
   non-NULL pointer when constructing a membership.
 * Explicitly initialize *imf to EX mode when the source address
   is unspecified.

This fixes a problem with in_mfilter slot recycling in the join path.

PR:		138690
Submitted by:	Stef Walter
MFC after:	5 days
This commit is contained in:
Bruce M Simpson 2009-09-12 19:45:55 +00:00
parent 2a8e7dad33
commit 1fc39d5424

View File

@ -1957,11 +1957,6 @@ inp_join_group(struct inpcb *inp, struct sockopt *sopt)
if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0)
return (EADDRNOTAVAIL);
/*
* MCAST_JOIN_SOURCE on an exclusive membership is an error.
* On an existing inclusive membership, it just adds the
* source to the filter list.
*/
imo = inp_findmoptions(inp);
idx = imo_match_group(imo, ifp, &gsa->sa);
if (idx == -1) {
@ -1969,15 +1964,33 @@ inp_join_group(struct inpcb *inp, struct sockopt *sopt)
} else {
inm = imo->imo_membership[idx];
imf = &imo->imo_mfilters[idx];
if (ssa->ss.ss_family != AF_UNSPEC &&
imf->imf_st[1] != MCAST_INCLUDE) {
error = EINVAL;
goto out_inp_locked;
}
lims = imo_match_source(imo, idx, &ssa->sa);
if (lims != NULL) {
error = EADDRNOTAVAIL;
goto out_inp_locked;
if (ssa->ss.ss_family != AF_UNSPEC) {
/*
* MCAST_JOIN_SOURCE on an exclusive membership
* is an error. On an existing inclusive membership,
* it just adds the source to the filter list.
*/
if (imf->imf_st[1] != MCAST_INCLUDE) {
error = EINVAL;
goto out_inp_locked;
}
/* Throw out duplicates. */
lims = imo_match_source(imo, idx, &ssa->sa);
if (lims != NULL) {
error = EADDRNOTAVAIL;
goto out_inp_locked;
}
} else {
/*
* MCAST_JOIN_GROUP on an existing inclusive
* membership is an error; if you want to change
* filter mode, you must use the userland API
* setsourcefilter().
*/
if (imf->imf_st[1] == MCAST_INCLUDE) {
error = EINVAL;
goto out_inp_locked;
}
}
}
@ -2010,7 +2023,8 @@ inp_join_group(struct inpcb *inp, struct sockopt *sopt)
/*
* Graft new source into filter list for this inpcb's
* membership of the group. The in_multi may not have
* been allocated yet if this is a new membership.
* been allocated yet if this is a new membership, however,
* the in_mfilter slot will be allocated and must be initialized.
*/
if (ssa->ss.ss_family != AF_UNSPEC) {
/* Membership starts in IN mode */
@ -2027,6 +2041,12 @@ inp_join_group(struct inpcb *inp, struct sockopt *sopt)
error = ENOMEM;
goto out_imo_free;
}
} else {
/* No address specified; Membership starts in EX mode */
if (is_new) {
CTR1(KTR_IGMPV3, "%s: new join w/o source", __func__);
imf_init(imf, MCAST_UNDEFINED, MCAST_EXCLUDE);
}
}
/*