From: NeilBrown Date: Mon, 17 Dec 2012 21:21:15 +0000 (-0500) Subject: mountd: fix is_subdirectory to understand '/' X-Git-Tag: debian/1%1.2.8-1~11^2^2~39 X-Git-Url: https://git.decadent.org.uk/gitweb/?a=commitdiff_plain;h=8e2fb3fc;p=nfs-utils.git mountd: fix is_subdirectory to understand '/' 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. Acked-by: J. Bruce Fields Signed-off-by: NeilBrown Signed-off-by: Steve Dickson --- 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) {