[PATCH 08/14] sunrpc: add netlink upcall for the auth.unix.ip cache

Jeff Layton
2026-03-16T15:15:20Z

Add netlink-based cache upcall support for the ip_map (auth.unix.ip)
cache, using the sunrpc generic netlink family.

Add ip-map attribute-set (seqno, class, addr, domain, negative, expiry),
ip-map-reqs wrapper, and ip-map-get-reqs / ip-map-set-reqs operations
to the sunrpc_cache YAML spec and generated headers.

Implement sunrpc_nl_ip_map_get_reqs_dumpit() which snapshots pending
ip_map cache requests and sends each entry's seqno, class name, and
IP address over netlink.

Implement sunrpc_nl_ip_map_set_reqs_doit() which parses ip_map cache
responses from userspace (class, addr, expiry, and domain name or
negative flag) and updates the cache via __ip_map_lookup() /
__ip_map_update().

Wire up ip_map_notify() callback in ip_map_cache_template so cache
misses trigger SUNRPC_CMD_CACHE_NOTIFY multicast events with
SUNRPC_CACHE_TYPE_IP_MAP.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
---
Documentation/netlink/specs/sunrpc_cache.yaml | 47 +++++
include/uapi/linux/sunrpc_netlink.h | 21 +++
net/sunrpc/netlink.c | 34 ++++
net/sunrpc/netlink.h | 8 +
net/sunrpc/svcauth_unix.c | 241 ++++++++++++++++++++++++++
5 files changed, 351 insertions(+)

diff --git a/Documentation/netlink/specs/sunrpc_cache.yaml b/Documentation/netlink/specs/sunrpc_cache.yaml
index f4aa699598bca9ce0215bbc418d9ddcae25c0110..8bcd43f65f3258ba43df4f80a7cfda5f09f2f13e 100644
--- a/Documentation/netlink/specs/sunrpc_cache.yaml
+++ b/Documentation/netlink/specs/sunrpc_cache.yaml
@@ -20,6 +20,35 @@ attribute-sets:
name: cache-type
type: u32
enum: cache-type
+ -
+ name: ip-map
+ attributes:
+ -
+ name: seqno
+ type: u64
+ -
+ name: class
+ type: string
+ -
+ name: addr
+ type: string
+ -
+ name: domain
+ type: string
+ -
+ name: negative
+ type: flag
+ -
+ name: expiry
+ type: u64
+ -
+ name: ip-map-reqs
+ attributes:
+ -
+ name: requests
+ type: nest
+ nested-attributes: ip-map
+ multi-attr: true

operations:
list:
@@ -31,6 +60,24 @@ operations:
event:
attributes:
- cache-type
+ -
+ name: ip-map-get-reqs
+ doc: Dump all pending ip_map requests
+ attribute-set: ip-map-reqs
+ flags: [admin-perm]
+ dump:
+ request:
+ attributes:
+ - requests
+ -
+ name: ip-map-set-reqs
+ doc: Respond to one or more ip_map requests
+ attribute-set: ip-map-reqs
+ flags: [admin-perm]
+ do:
+ request:
+ attributes:
+ - requests

mcast-groups:
list:
diff --git a/include/uapi/linux/sunrpc_netlink.h b/include/uapi/linux/sunrpc_netlink.h
index 6135d9b3eef155a9192d9710c8c690283ec49073..b44befb5a34b956e70065e0e12b816e2943da66e 100644
--- a/include/uapi/linux/sunrpc_netlink.h
+++ b/include/uapi/linux/sunrpc_netlink.h
@@ -22,8 +22,29 @@ enum {
SUNRPC_A_CACHE_NOTIFY_MAX = (__SUNRPC_A_CACHE_NOTIFY_MAX - 1)
};

+enum {
+ SUNRPC_A_IP_MAP_SEQNO = 1,
+ SUNRPC_A_IP_MAP_CLASS,
+ SUNRPC_A_IP_MAP_ADDR,
+ SUNRPC_A_IP_MAP_DOMAIN,
+ SUNRPC_A_IP_MAP_NEGATIVE,
+ SUNRPC_A_IP_MAP_EXPIRY,
+
+ __SUNRPC_A_IP_MAP_MAX,
+ SUNRPC_A_IP_MAP_MAX = (__SUNRPC_A_IP_MAP_MAX - 1)
+};
+
+enum {
+ SUNRPC_A_IP_MAP_REQS_REQUESTS = 1,
+
+ __SUNRPC_A_IP_MAP_REQS_MAX,
+ SUNRPC_A_IP_MAP_REQS_MAX = (__SUNRPC_A_IP_MAP_REQS_MAX - 1)
+};
+
enum {
SUNRPC_CMD_CACHE_NOTIFY = 1,
+ SUNRPC_CMD_IP_MAP_GET_REQS,
+ SUNRPC_CMD_IP_MAP_SET_REQS,

__SUNRPC_CMD_MAX,
SUNRPC_CMD_MAX = (__SUNRPC_CMD_MAX - 1)
diff --git a/net/sunrpc/netlink.c b/net/sunrpc/netlink.c
index e59ee82dfab358fc367045d9f04c394000c812ec..baeaf28fda02f120c2cd4778fcb444850ae8868a 100644
--- a/net/sunrpc/netlink.c
+++ b/net/sunrpc/netlink.c
@@ -12,8 +12,42 @@

#include <uapi/linux/sunrpc_netlink.h>

+/* Common nested types */
+const struct nla_policy sunrpc_ip_map_nl_policy[SUNRPC_A_IP_MAP_EXPIRY + 1] = {
+ [SUNRPC_A_IP_MAP_SEQNO] = { .type = NLA_U64, },
+ [SUNRPC_A_IP_MAP_CLASS] = { .type = NLA_NUL_STRING, },
+ [SUNRPC_A_IP_MAP_ADDR] = { .type = NLA_NUL_STRING, },
+ [SUNRPC_A_IP_MAP_DOMAIN] = { .type = NLA_NUL_STRING, },
+ [SUNRPC_A_IP_MAP_NEGATIVE] = { .type = NLA_FLAG, },
+ [SUNRPC_A_IP_MAP_EXPIRY] = { .type = NLA_U64, },
+};
+
+/* SUNRPC_CMD_IP_MAP_GET_REQS - dump */
+static const struct nla_policy sunrpc_ip_map_get_reqs_nl_policy[SUNRPC_A_IP_MAP_REQS_REQUESTS + 1] = {
+ [SUNRPC_A_IP_MAP_REQS_REQUESTS] = NLA_POLICY_NESTED(sunrpc_ip_map_nl_policy),
+};
+
+/* SUNRPC_CMD_IP_MAP_SET_REQS - do */
+static const struct nla_policy sunrpc_ip_map_set_reqs_nl_policy[SUNRPC_A_IP_MAP_REQS_REQUESTS + 1] = {
+ [SUNRPC_A_IP_MAP_REQS_REQUESTS] = NLA_POLICY_NESTED(sunrpc_ip_map_nl_policy),
+};
+
/* Ops table for sunrpc */
static const struct genl_split_ops sunrpc_nl_ops[] = {
+ {
+ .cmd = SUNRPC_CMD_IP_MAP_GET_REQS,
+ .dumpit = sunrpc_nl_ip_map_get_reqs_dumpit,
+ .policy = sunrpc_ip_map_get_reqs_nl_policy,
+ .maxattr = SUNRPC_A_IP_MAP_REQS_REQUESTS,
+ .flags = GENL_ADMIN_PERM | GENL_CMD_CAP_DUMP,
+ },
+ {
+ .cmd = SUNRPC_CMD_IP_MAP_SET_REQS,
+ .doit = sunrpc_nl_ip_map_set_reqs_doit,
+ .policy = sunrpc_ip_map_set_reqs_nl_policy,
+ .maxattr = SUNRPC_A_IP_MAP_REQS_REQUESTS,
+ .flags = GENL_ADMIN_PERM | GENL_CMD_CAP_DO,
+ },
};

static const struct genl_multicast_group sunrpc_nl_mcgrps[] = {
diff --git a/net/sunrpc/netlink.h b/net/sunrpc/netlink.h
index efb05f87b89513fe738964a1b27637a09f9b88a9..6849faec517ea33ddc5cafab827381984e0dc602 100644
--- a/net/sunrpc/netlink.h
+++ b/net/sunrpc/netlink.h
@@ -12,6 +12,14 @@

#include <uapi/linux/sunrpc_netlink.h>

+/* Common nested types */
+extern const struct nla_policy sunrpc_ip_map_nl_policy[SUNRPC_A_IP_MAP_EXPIRY + 1];
+
+int sunrpc_nl_ip_map_get_reqs_dumpit(struct sk_buff *skb,
+ struct netlink_callback *cb);
+int sunrpc_nl_ip_map_set_reqs_doit(struct sk_buff *skb,
+ struct genl_info *info);
+
enum {
SUNRPC_NLGRP_NONE,
SUNRPC_NLGRP_EXPORTD,
diff --git a/net/sunrpc/svcauth_unix.c b/net/sunrpc/svcauth_unix.c
index 87732c4cb8383c64b440538a0d3f3113a3009b4e..e4b196742877bd3abf199f2bf815b90615a2be04 100644
--- a/net/sunrpc/svcauth_unix.c
+++ b/net/sunrpc/svcauth_unix.c
@@ -17,11 +17,14 @@
#include <net/ipv6.h>
#include <linux/kernel.h>
#include <linux/user_namespace.h>
+#include <net/genetlink.h>
+#include <uapi/linux/sunrpc_netlink.h>
#include <trace/events/sunrpc.h>

#define RPCDBG_FACILITY RPCDBG_AUTH

#include "netns.h"
+#include "netlink.h"

/*
* AUTHUNIX and AUTHNULL credentials are both handled here.
@@ -1017,12 +1020,250 @@ struct auth_ops svcauth_unix = {
.set_client = svcauth_unix_set_client,
};

+static int ip_map_notify(struct cache_detail *cd, struct cache_head *h)
+{
+ return sunrpc_cache_notify(cd, h, SUNRPC_CACHE_TYPE_IP_MAP);
+}
+
+/**
+ * sunrpc_nl_ip_map_get_reqs_dumpit - dump pending ip_map requests
+ * @skb: reply buffer
+ * @cb: netlink metadata and command arguments
+ *
+ * Walk the ip_map cache's pending request list and create a netlink
+ * message with a nested entry for each cache_request, containing the
+ * seqno, class and addr.
+ *
+ * Returns the size of the reply or a negative errno.
+ */
+int sunrpc_nl_ip_map_get_reqs_dumpit(struct sk_buff *skb,
+ struct netlink_callback *cb)
+{
+ struct sunrpc_net *sn;
+ struct cache_detail *cd;
+ struct cache_head **items;
+ u64 *seqnos;
+ int cnt, i;
+ void *hdr;
+ int ret;
+
+ sn = net_generic(sock_net(skb->sk), sunrpc_net_id);
+
+ cd = sn->ip_map_cache;
+ if (!cd)
+ return -ENODEV;
+
+ /* Second call means we've already dumped everything */
+ if (cb->args[0])
+ return 0;
+
+ cnt = sunrpc_cache_requests_count(cd);
+ if (!cnt)
+ return 0;
+
+ items = kcalloc(cnt, sizeof(*items), GFP_KERNEL);
+ seqnos = kcalloc(cnt, sizeof(*seqnos), GFP_KERNEL);
+ if (!items || !seqnos) {
+ ret = -ENOMEM;
+ goto out_alloc;
+ }
+
+ cnt = sunrpc_cache_requests_snapshot(cd, items, seqnos, cnt);
+
+ hdr = genlmsg_put(skb, NETLINK_CB(cb->skb).portid,
+ cb->nlh->nlmsg_seq, &sunrpc_nl_family,
+ NLM_F_MULTI, SUNRPC_CMD_IP_MAP_GET_REQS);
+ if (!hdr) {
+ ret = -ENOBUFS;
+ goto out_put;
+ }
+
+ for (i = 0; i < cnt; i++) {
+ struct ip_map *im;
+ struct nlattr *nest;
+ char text_addr[40];
+
+ im = container_of(items[i], struct ip_map, h);
+
+ if (ipv6_addr_v4mapped(&im->m_addr))
+ snprintf(text_addr, 20, "%pI4",
+ &im->m_addr.s6_addr32[3]);
+ else
+ snprintf(text_addr, 40, "%pI6", &im->m_addr);
+
+ nest = nla_nest_start(skb, SUNRPC_A_IP_MAP_REQS_REQUESTS);
+ if (!nest) {
+ ret = -ENOBUFS;
+ goto out_cancel;
+ }
+
+ if (nla_put_u64_64bit(skb, SUNRPC_A_IP_MAP_SEQNO,
+ seqnos[i], 0) ||
+ nla_put_string(skb, SUNRPC_A_IP_MAP_CLASS,
+ im->m_class) ||
+ nla_put_string(skb, SUNRPC_A_IP_MAP_ADDR, text_addr)) {
+ nla_nest_cancel(skb, nest);
+ ret = -ENOBUFS;
+ goto out_cancel;
+ }
+
+ nla_nest_end(skb, nest);
+ }
+
+ genlmsg_end(skb, hdr);
+ cb->args[0] = 1;
+ ret = skb->len;
+ goto out_put;
+
+out_cancel:
+ genlmsg_cancel(skb, hdr);
+out_put:
+ for (i = 0; i < cnt; i++)
+ cache_put(items[i], cd);
+out_alloc:
+ kfree(seqnos);
+ kfree(items);
+ return ret;
+}
+
+/**
+ * sunrpc_nl_parse_one_ip_map - parse one ip_map entry from netlink
+ * @cd: cache_detail for the ip_map cache
+ * @attr: nested attribute containing ip_map fields
+ *
+ * Parses one ip_map entry from a netlink message and updates the
+ * cache. Mirrors the logic in ip_map_parse().
+ *
+ * Returns 0 on success or a negative errno.
+ */
+static int sunrpc_nl_parse_one_ip_map(struct cache_detail *cd,
+ struct nlattr *attr)
+{
+ struct nlattr *tb[SUNRPC_A_IP_MAP_EXPIRY + 1];
+ union {
+ struct sockaddr sa;
+ struct sockaddr_in s4;
+ struct sockaddr_in6 s6;
+ } address;
+ struct sockaddr_in6 sin6;
+ struct ip_map *ipmp;
+ struct auth_domain *dom = NULL;
+ struct unix_domain *udom = NULL;
+ struct timespec64 boot;
+ time64_t expiry;
+ char class[8];
+ int err;
+ int len;
+
+ err = nla_parse_nested(tb, SUNRPC_A_IP_MAP_EXPIRY, attr,
+ sunrpc_ip_map_nl_policy, NULL);
+ if (err)
+ return err;
+
+ /* class (required) */
+ if (!tb[SUNRPC_A_IP_MAP_CLASS])
+ return -EINVAL;
+ len = nla_len(tb[SUNRPC_A_IP_MAP_CLASS]);
+ if (len <= 0 || len > sizeof(class))
+ return -EINVAL;
+ nla_strscpy(class, tb[SUNRPC_A_IP_MAP_CLASS], sizeof(class));
+
+ /* addr (required) */
+ if (!tb[SUNRPC_A_IP_MAP_ADDR])
+ return -EINVAL;
+ if (rpc_pton(cd->net, nla_data(tb[SUNRPC_A_IP_MAP_ADDR]),
+ nla_len(tb[SUNRPC_A_IP_MAP_ADDR]) - 1,
+ &address.sa, sizeof(address)) == 0)
+ return -EINVAL;
+
+ switch (address.sa.sa_family) {
+ case AF_INET:
+ sin6.sin6_family = AF_INET6;
+ ipv6_addr_set_v4mapped(address.s4.sin_addr.s_addr,
+ &sin6.sin6_addr);
+ break;
+#if IS_ENABLED(CONFIG_IPV6)
+ case AF_INET6:
+ memcpy(&sin6, &address.s6, sizeof(sin6));
+ break;
+#endif
+ default:
+ return -EINVAL;
+ }
+
+ /* expiry (required, wallclock seconds) */
+ if (!tb[SUNRPC_A_IP_MAP_EXPIRY])
+ return -EINVAL;
+ getboottime64(&boot);
+ expiry = nla_get_u64(tb[SUNRPC_A_IP_MAP_EXPIRY]) - boot.tv_sec;
+
+ /* domain name or negative */
+ if (tb[SUNRPC_A_IP_MAP_NEGATIVE]) {
+ udom = NULL;
+ } else if (tb[SUNRPC_A_IP_MAP_DOMAIN]) {
+ dom = unix_domain_find(nla_data(tb[SUNRPC_A_IP_MAP_DOMAIN]));
+ if (!dom)
+ return -ENOENT;
+ udom = container_of(dom, struct unix_domain, h);
+ } else {
+ return -EINVAL;
+ }
+
+ ipmp = __ip_map_lookup(cd, class, &sin6.sin6_addr);
+ if (ipmp)
+ err = __ip_map_update(cd, ipmp, udom, expiry);
+ else
+ err = -ENOMEM;
+
+ if (dom)
+ auth_domain_put(dom);
+
+ cache_flush();
+ return err;
+}
+
+/**
+ * sunrpc_nl_ip_map_set_reqs_doit - respond to ip_map requests
+ * @skb: reply buffer
+ * @info: netlink metadata and command arguments
+ *
+ * Parse one or more ip_map cache responses from userspace and
+ * update the ip_map cache accordingly.
+ *
+ * Returns 0 on success or a negative errno.
+ */
+int sunrpc_nl_ip_map_set_reqs_doit(struct sk_buff *skb,
+ struct genl_info *info)
+{
+ struct sunrpc_net *sn;
+ struct cache_detail *cd;
+ const struct nlattr *attr;
+ int rem, ret = 0;
+
+ sn = net_generic(genl_info_net(info), sunrpc_net_id);
+
+ cd = sn->ip_map_cache;
+ if (!cd)
+ return -ENODEV;
+
+ nlmsg_for_each_attr_type(attr, SUNRPC_A_IP_MAP_REQS_REQUESTS,
+ info->nlhdr, GENL_HDRLEN, rem) {
+ ret = sunrpc_nl_parse_one_ip_map(cd,
+ (struct nlattr *)attr);
+ if (ret)
+ break;
+ }
+
+ return ret;
+}
+
static const struct cache_detail ip_map_cache_template = {
.owner = THIS_MODULE,
.hash_size = IP_HASHMAX,
.name = "auth.unix.ip",
.cache_put = ip_map_put,
.cache_upcall = ip_map_upcall,
+ .cache_notify = ip_map_notify,
.cache_request = ip_map_request,
.cache_parse = ip_map_parse,
.cache_show = ip_map_show,

--
2.53.0