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>
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@ -46,7 +46,7 @@ const struct cred *dns_resolver_cache;
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#define DNS_ERRORNO_OPTION "dnserror"
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/*
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* Instantiate a user defined key for dns_resolver.
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* Preparse instantiation data for a dns_resolver key.
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*
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* The data must be a NUL-terminated string, with the NUL char accounted in
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* datalen.
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@ -58,17 +58,15 @@ const struct cred *dns_resolver_cache;
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* "ip1,ip2,...#foo=bar"
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*/
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static int
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dns_resolver_instantiate(struct key *key, struct key_preparsed_payload *prep)
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dns_resolver_preparse(struct key_preparsed_payload *prep)
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{
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struct user_key_payload *upayload;
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unsigned long derrno;
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int ret;
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size_t datalen = prep->datalen, result_len = 0;
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int datalen = prep->datalen, result_len = 0;
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const char *data = prep->data, *end, *opt;
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kenter("%%%d,%s,'%*.*s',%zu",
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key->serial, key->description,
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(int)datalen, (int)datalen, data, datalen);
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kenter("'%*.*s',%u", datalen, datalen, data, datalen);
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if (datalen <= 1 || !data || data[datalen - 1] != '\0')
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return -EINVAL;
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@ -95,8 +93,7 @@ dns_resolver_instantiate(struct key *key, struct key_preparsed_payload *prep)
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opt_len = next_opt - opt;
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if (!opt_len) {
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printk(KERN_WARNING
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"Empty option to dns_resolver key %d\n",
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key->serial);
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"Empty option to dns_resolver key\n");
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return -EINVAL;
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}
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@ -125,30 +122,28 @@ dns_resolver_instantiate(struct key *key, struct key_preparsed_payload *prep)
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goto bad_option_value;
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kdebug("dns error no. = %lu", derrno);
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key->type_data.x[0] = -derrno;
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prep->type_data[0] = ERR_PTR(-derrno);
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continue;
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}
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bad_option_value:
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printk(KERN_WARNING
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"Option '%*.*s' to dns_resolver key %d:"
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"Option '%*.*s' to dns_resolver key:"
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" bad/missing value\n",
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opt_nlen, opt_nlen, opt, key->serial);
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opt_nlen, opt_nlen, opt);
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return -EINVAL;
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} while (opt = next_opt + 1, opt < end);
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}
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/* don't cache the result if we're caching an error saying there's no
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* result */
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if (key->type_data.x[0]) {
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kleave(" = 0 [h_error %ld]", key->type_data.x[0]);
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if (prep->type_data[0]) {
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kleave(" = 0 [h_error %ld]", PTR_ERR(prep->type_data[0]));
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return 0;
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}
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kdebug("store result");
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ret = key_payload_reserve(key, result_len);
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if (ret < 0)
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return -EINVAL;
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prep->quotalen = result_len;
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upayload = kmalloc(sizeof(*upayload) + result_len + 1, GFP_KERNEL);
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if (!upayload) {
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@ -159,12 +154,22 @@ dns_resolver_instantiate(struct key *key, struct key_preparsed_payload *prep)
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upayload->datalen = result_len;
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memcpy(upayload->data, data, result_len);
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upayload->data[result_len] = '\0';
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rcu_assign_pointer(key->payload.data, upayload);
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prep->payload[0] = upayload;
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kleave(" = 0");
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return 0;
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}
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/*
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* Clean up the preparse data
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*/
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static void dns_resolver_free_preparse(struct key_preparsed_payload *prep)
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{
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pr_devel("==>%s()\n", __func__);
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kfree(prep->payload[0]);
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}
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/*
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* The description is of the form "[<type>:]<domain_name>"
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*
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@ -234,7 +239,9 @@ static long dns_resolver_read(const struct key *key,
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struct key_type key_type_dns_resolver = {
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.name = "dns_resolver",
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.instantiate = dns_resolver_instantiate,
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.preparse = dns_resolver_preparse,
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.free_preparse = dns_resolver_free_preparse,
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.instantiate = generic_key_instantiate,
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.match = dns_resolver_match,
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.revoke = user_revoke,
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.destroy = user_destroy,
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