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authorDavid Howells <dhowells@redhat.com>2014-07-18 18:56:36 +0100
committerDavid Howells <dhowells@redhat.com>2014-07-22 21:46:36 +0100
commitd46d494214cabfd03eb836e3a8ff3768d4c51497 (patch)
treefbd32f43b69ef9eb79e1694f1ba38a82ac458732 /net/dns_resolver
parentKEYS: Ceph: Use user_match() (diff)
downloadlinux-dev-d46d494214cabfd03eb836e3a8ff3768d4c51497.tar.xz
linux-dev-d46d494214cabfd03eb836e3a8ff3768d4c51497.zip
KEYS: DNS: Use key preparsing
Make use of key preparsing in the DNS resolver so that quota size determination can take place prior to keyring locking when a key is being added. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Steve Dickson <steved@redhat.com> Acked-by: Jeff Layton <jlayton@primarydata.com>
Diffstat (limited to 'net/dns_resolver')
-rw-r--r--net/dns_resolver/dns_key.c43
1 files changed, 25 insertions, 18 deletions
diff --git a/net/dns_resolver/dns_key.c b/net/dns_resolver/dns_key.c
index bf8584339048..f380b2c58178 100644
--- a/net/dns_resolver/dns_key.c
+++ b/net/dns_resolver/dns_key.c
@@ -46,7 +46,7 @@ const struct cred *dns_resolver_cache;
#define DNS_ERRORNO_OPTION "dnserror"
/*
- * Instantiate a user defined key for dns_resolver.
+ * Preparse instantiation data for a dns_resolver key.
*
* The data must be a NUL-terminated string, with the NUL char accounted in
* datalen.
@@ -58,17 +58,15 @@ const struct cred *dns_resolver_cache;
* "ip1,ip2,...#foo=bar"
*/
static int
-dns_resolver_instantiate(struct key *key, struct key_preparsed_payload *prep)
+dns_resolver_preparse(struct key_preparsed_payload *prep)
{
struct user_key_payload *upayload;
unsigned long derrno;
int ret;
- size_t datalen = prep->datalen, result_len = 0;
+ int datalen = prep->datalen, result_len = 0;
const char *data = prep->data, *end, *opt;
- kenter("%%%d,%s,'%*.*s',%zu",
- key->serial, key->description,
- (int)datalen, (int)datalen, data, datalen);
+ kenter("'%*.*s',%u", datalen, datalen, data, datalen);
if (datalen <= 1 || !data || data[datalen - 1] != '\0')
return -EINVAL;
@@ -95,8 +93,7 @@ dns_resolver_instantiate(struct key *key, struct key_preparsed_payload *prep)
opt_len = next_opt - opt;
if (!opt_len) {
printk(KERN_WARNING
- "Empty option to dns_resolver key %d\n",
- key->serial);
+ "Empty option to dns_resolver key\n");
return -EINVAL;
}
@@ -125,30 +122,28 @@ dns_resolver_instantiate(struct key *key, struct key_preparsed_payload *prep)
goto bad_option_value;
kdebug("dns error no. = %lu", derrno);
- key->type_data.x[0] = -derrno;
+ prep->type_data[0] = ERR_PTR(-derrno);
continue;
}
bad_option_value:
printk(KERN_WARNING
- "Option '%*.*s' to dns_resolver key %d:"
+ "Option '%*.*s' to dns_resolver key:"
" bad/missing value\n",
- opt_nlen, opt_nlen, opt, key->serial);
+ opt_nlen, opt_nlen, opt);
return -EINVAL;
} while (opt = next_opt + 1, opt < end);
}
/* don't cache the result if we're caching an error saying there's no
* result */
- if (key->type_data.x[0]) {
- kleave(" = 0 [h_error %ld]", key->type_data.x[0]);
+ if (prep->type_data[0]) {
+ kleave(" = 0 [h_error %ld]", PTR_ERR(prep->type_data[0]));
return 0;
}
kdebug("store result");
- ret = key_payload_reserve(key, result_len);
- if (ret < 0)
- return -EINVAL;
+ prep->quotalen = result_len;
upayload = kmalloc(sizeof(*upayload) + result_len + 1, GFP_KERNEL);
if (!upayload) {
@@ -159,13 +154,23 @@ dns_resolver_instantiate(struct key *key, struct key_preparsed_payload *prep)
upayload->datalen = result_len;
memcpy(upayload->data, data, result_len);
upayload->data[result_len] = '\0';
- rcu_assign_pointer(key->payload.data, upayload);
+ prep->payload[0] = upayload;
kleave(" = 0");
return 0;
}
/*
+ * Clean up the preparse data
+ */
+static void dns_resolver_free_preparse(struct key_preparsed_payload *prep)
+{
+ pr_devel("==>%s()\n", __func__);
+
+ kfree(prep->payload[0]);
+}
+
+/*
* The description is of the form "[<type>:]<domain_name>"
*
* The domain name may be a simple name or an absolute domain name (which
@@ -234,7 +239,9 @@ static long dns_resolver_read(const struct key *key,
struct key_type key_type_dns_resolver = {
.name = "dns_resolver",
- .instantiate = dns_resolver_instantiate,
+ .preparse = dns_resolver_preparse,
+ .free_preparse = dns_resolver_free_preparse,
+ .instantiate = generic_key_instantiate,
.match = dns_resolver_match,
.revoke = user_revoke,
.destroy = user_destroy,