From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: linux-nfs-owner@vger.kernel.org Received: from mx1.redhat.com ([209.132.183.28]:26048 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751777Ab2LQVqh (ORCPT ); Mon, 17 Dec 2012 16:46:37 -0500 Message-ID: <50CF929D.70209@RedHat.com> Date: Mon, 17 Dec 2012 16:46:05 -0500 From: Steve Dickson MIME-Version: 1.0 To: NeilBrown CC: NFS Subject: Re: [nfs-utils PATCH] mountd: fix is_subdirectory to understand '/' References: <20121213112342.720ddc6d@notabene.brown> In-Reply-To: <20121213112342.720ddc6d@notabene.brown> Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-nfs-owner@vger.kernel.org List-ID: On 12/12/12 19:23, NeilBrown wrote: > > The is_subdirectory() function checks if a given 'child' is a subdirectory > of the given 'parent'. > However it always fails if 'parent' == "/" (because 'child' doesn't begin > with 'parent' followed by "/"). > > So change is_subdirectory() to special-case "/". > > subexport() also tests if one directory is a subdirectory of the > other, and contains the same bug. So change it to use is_subdirectory(). > > Finally, move is_subdirectory() and related path_matches() and > export_matches() earlier in the file to avoid a forward-reference. > > This patch fixes a bug wherein if you export "/" with 'crossmnt', the > crossmnt flag is ineffective and you can only access the root > filesystem, not any descendants. > > Signed-off-by: NeilBrown Committed... steved. > > diff --git a/utils/mountd/cache.c b/utils/mountd/cache.c > index 3853bb6..45012be 100644 > --- a/utils/mountd/cache.c > +++ b/utils/mountd/cache.c > @@ -343,6 +343,30 @@ static char *next_mnt(void **v, char *p) > return me->mnt_dir; > } > > +static int is_subdirectory(char *child, char *parent) > +{ > + size_t l = strlen(parent); > + > + if (strcmp(parent, "/") == 0) > + return 1; > + > + return strcmp(child, parent) == 0 > + || (strncmp(child, parent, l) == 0 && child[l] == '/'); > +} > + > +static int path_matches(nfs_export *exp, char *path) > +{ > + if (exp->m_export.e_flags & NFSEXP_CROSSMOUNT) > + return is_subdirectory(path, exp->m_export.e_path); > + return strcmp(path, exp->m_export.e_path) == 0; > +} > + > +static int > +export_matches(nfs_export *exp, char *dom, char *path, struct addrinfo *ai) > +{ > + return path_matches(exp, path) && client_matches(exp, dom, ai); > +} > + > /* True iff e1 is a child of e2 and e2 has crossmnt set: */ > static bool subexport(struct exportent *e1, struct exportent *e2) > { > @@ -350,8 +374,7 @@ static bool subexport(struct exportent *e1, struct exportent *e2) > size_t l2 = strlen(p2); > > return e2->e_flags & NFSEXP_CROSSMOUNT > - && strncmp(p1, p2, l2) == 0 > - && p1[l2] == '/'; > + && is_subdirectory(p1, p2); > } > > struct parsed_fsid { > @@ -752,27 +775,6 @@ static int dump_to_cache(FILE *f, char *domain, char *path, struct exportent *ex > return qword_eol(f); > } > > -static int is_subdirectory(char *child, char *parent) > -{ > - size_t l = strlen(parent); > - > - return strcmp(child, parent) == 0 > - || (strncmp(child, parent, l) == 0 && child[l] == '/'); > -} > - > -static int path_matches(nfs_export *exp, char *path) > -{ > - if (exp->m_export.e_flags & NFSEXP_CROSSMOUNT) > - return is_subdirectory(path, exp->m_export.e_path); > - return strcmp(path, exp->m_export.e_path) == 0; > -} > - > -static int > -export_matches(nfs_export *exp, char *dom, char *path, struct addrinfo *ai) > -{ > - return path_matches(exp, path) && client_matches(exp, dom, ai); > -} > - > static nfs_export * > lookup_export(char *dom, char *path, struct addrinfo *ai) > { >