From: "J. Bruce Fields" <bfields@xxxxxxxxxx>
Mountd is responsible for filling three interrelated kernel caches:
- auth_unix_ip maps an incoming ip addresses to a "domain".
- nfsd_fh maps (domain, filehandle-fragment) pairs to paths.
- nfsd_export maps (domain, path) pairs to export options.
Note that each export is assocated with a "client" string--the part
before the parentheses in an /etc/export line--which may be a domain
name, a netgroup, etc.
The "domain" string in the above three caches may be either:
- in the !use_ipaddr case, a comma-separated list of client
strings.
- in the use_ipaddr case, an ip address.
In the former case, mountd does the hard work of matching an ip address
to the clients when doing the auth_unix_ip mapping. In the latter case,
it delays that until the nfsd_fh or nfsd_export upcall.
We're currently depending on being able to flush the kernel caches
completely when switching between the use_ipaddr and !use_ipaddr cases.
However, the kernel's cache-flushing doesn't really provide reliable
guarantees on return; it's still possible we could see nfsd_fh or
nfsd_export upcalls with the old domain-type after flushing.
So, instead, make the two domain types self-describing by prepending a
"$" in the use_ipaddr case.
Signed-off-by: J. Bruce Fields <bfields@xxxxxxxxxx>
---
utils/mountd/auth.c | 14 +++++++++++---
utils/mountd/cache.c | 8 +++++---
utils/mountd/mountd.h | 5 +++++
3 files changed, 21 insertions(+), 6 deletions(-)
diff --git a/utils/mountd/auth.c b/utils/mountd/auth.c
index 1ed9a4b..15da54c 100644
--- a/utils/mountd/auth.c
+++ b/utils/mountd/auth.c
@@ -112,15 +112,23 @@ auth_reload()
return counter;
}
+static char *get_client_ipaddr_name(const struct sockaddr *caller)
+{
+ char buf[INET6_ADDRSTRLEN + 1];
+
+ buf[0] = '$';
+ host_ntop(caller, buf + 1, sizeof(buf) - 1);
+ return strdup(buf);
+}
+
static char *
get_client_hostname(const struct sockaddr *caller, struct addrinfo *ai,
enum auth_error *error)
{
- char buf[INET6_ADDRSTRLEN];
char *n;
if (use_ipaddr)
- return strdup(host_ntop(caller, buf, sizeof(buf)));
+ return get_client_ipaddr_name(caller);
n = client_compose(ai);
*error = unknown_host;
if (!n)
@@ -143,7 +151,7 @@ bool namelist_client_matches(nfs_export *exp, char *dom)
bool client_matches(nfs_export *exp, char *dom, struct addrinfo *ai)
{
- if (use_ipaddr)
+ if (is_ipaddr_client(dom))
return ipaddr_client_matches(exp, ai);
return namelist_client_matches(exp, dom);
}
diff --git a/utils/mountd/cache.c b/utils/mountd/cache.c
index 6cc58d2..1833b3a 100644
--- a/utils/mountd/cache.c
+++ b/utils/mountd/cache.c
@@ -551,7 +551,7 @@ static void nfsd_fh(FILE *f)
auth_reload();
- if (use_ipaddr) {
+ if (dom[0] == '$') {
ai = lookup_client_addr(dom);
if (!ai)
goto out;
@@ -587,7 +587,8 @@ static void nfsd_fh(FILE *f)
next_exp = exp->m_next;
}
- if (!use_ipaddr && !namelist_client_matches(exp, dom))
+ if (!is_ipaddr_client(dom)
+ && !namelist_client_matches(exp, dom))
continue;
if (exp->m_export.e_mountpoint &&
!is_mountpoint(exp->m_export.e_mountpoint[0]?
@@ -597,7 +598,8 @@ static void nfsd_fh(FILE *f)
if (!match_fsid(&parsed, exp, path))
continue;
- if (use_ipaddr && !ipaddr_client_matches(exp, ai))
+ if (is_ipaddr_client(dom)
+ && !ipaddr_client_matches(exp, ai))
continue;
if (!found || subexport(&exp->m_export, found)) {
found = &exp->m_export;
diff --git a/utils/mountd/mountd.h b/utils/mountd/mountd.h
index c969a27..6d358a7 100644
--- a/utils/mountd/mountd.h
+++ b/utils/mountd/mountd.h
@@ -60,4 +60,9 @@ bool ipaddr_client_matches(nfs_export *exp, struct addrinfo *ai);
bool namelist_client_matches(nfs_export *exp, char *dom);
bool client_matches(nfs_export *exp, char *dom, struct addrinfo *ai);
+static inline bool is_ipaddr_client(char *dom)
+{
+ return dom[0] == '$';
+}
+
#endif /* MOUNTD_H */
--
1.7.7.6
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