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authorJakub Kicinski <kuba@kernel.org>2020-10-02 14:49:53 -0700
committerDavid S. Miller <davem@davemloft.net>2020-10-02 19:11:11 -0700
commit0b588afdd16f9e0b63128dc4bcd002e7f2725fe0 (patch)
treea3a8b861434b65311b9332016a20749d58324cad /net
parente5086736969880478abb2ac85ef8757ac6ce45bf (diff)
genetlink: add small version of ops
We want to add maxattr and policy back to genl_ops, to enable dumping per command policy to user space. This, however, would cause bloat for all the families with global policies. Introduce smaller version of ops (half the size of genl_ops). Translate these smaller ops into a full blown struct before use in the core. v1: - use struct assignment - put a full copy of the op in struct genl_dumpit_info - s/light/small/ Signed-off-by: Jakub Kicinski <kuba@kernel.org> Reviewed-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/netlink/genetlink.c127
1 files changed, 95 insertions, 32 deletions
diff --git a/net/netlink/genetlink.c b/net/netlink/genetlink.c
index 4a95e85cf907..42a3c6c7a5ee 100644
--- a/net/netlink/genetlink.c
+++ b/net/netlink/genetlink.c
@@ -107,16 +107,75 @@ static const struct genl_family *genl_family_find_byname(char *name)
return NULL;
}
-static const struct genl_ops *genl_get_cmd(u8 cmd,
- const struct genl_family *family)
+static int genl_get_cmd_cnt(const struct genl_family *family)
+{
+ return family->n_ops + family->n_small_ops;
+}
+
+static void genl_op_from_full(const struct genl_family *family,
+ unsigned int i, struct genl_ops *op)
+{
+ *op = family->ops[i];
+}
+
+static int genl_get_cmd_full(u8 cmd, const struct genl_family *family,
+ struct genl_ops *op)
{
int i;
for (i = 0; i < family->n_ops; i++)
- if (family->ops[i].cmd == cmd)
- return &family->ops[i];
+ if (family->ops[i].cmd == cmd) {
+ genl_op_from_full(family, i, op);
+ return 0;
+ }
- return NULL;
+ return -ENOENT;
+}
+
+static void genl_op_from_small(const struct genl_family *family,
+ unsigned int i, struct genl_ops *op)
+{
+ memset(op, 0, sizeof(*op));
+ op->doit = family->small_ops[i].doit;
+ op->dumpit = family->small_ops[i].dumpit;
+ op->cmd = family->small_ops[i].cmd;
+ op->internal_flags = family->small_ops[i].internal_flags;
+ op->flags = family->small_ops[i].flags;
+ op->validate = family->small_ops[i].validate;
+}
+
+static int genl_get_cmd_small(u8 cmd, const struct genl_family *family,
+ struct genl_ops *op)
+{
+ int i;
+
+ for (i = 0; i < family->n_small_ops; i++)
+ if (family->small_ops[i].cmd == cmd) {
+ genl_op_from_small(family, i, op);
+ return 0;
+ }
+
+ return -ENOENT;
+}
+
+static int genl_get_cmd(u8 cmd, const struct genl_family *family,
+ struct genl_ops *op)
+{
+ if (!genl_get_cmd_full(cmd, family, op))
+ return 0;
+ return genl_get_cmd_small(cmd, family, op);
+}
+
+static void genl_get_cmd_by_index(unsigned int i,
+ const struct genl_family *family,
+ struct genl_ops *op)
+{
+ if (i < family->n_ops)
+ genl_op_from_full(family, i, op);
+ else if (i < family->n_ops + family->n_small_ops)
+ genl_op_from_small(family, i - family->n_ops, op);
+ else
+ WARN_ON_ONCE(1);
}
static int genl_allocate_reserve_groups(int n_groups, int *first_id)
@@ -286,22 +345,25 @@ static void genl_unregister_mc_groups(const struct genl_family *family)
static int genl_validate_ops(const struct genl_family *family)
{
- const struct genl_ops *ops = family->ops;
- unsigned int n_ops = family->n_ops;
int i, j;
- if (WARN_ON(n_ops && !ops))
+ if (WARN_ON(family->n_ops && !family->ops) ||
+ WARN_ON(family->n_small_ops && !family->small_ops))
return -EINVAL;
- if (!n_ops)
- return 0;
+ for (i = 0; i < genl_get_cmd_cnt(family); i++) {
+ struct genl_ops op;
- for (i = 0; i < n_ops; i++) {
- if (ops[i].dumpit == NULL && ops[i].doit == NULL)
+ genl_get_cmd_by_index(i, family, &op);
+ if (op.dumpit == NULL && op.doit == NULL)
return -EINVAL;
- for (j = i + 1; j < n_ops; j++)
- if (ops[i].cmd == ops[j].cmd)
+ for (j = i + 1; j < genl_get_cmd_cnt(family); j++) {
+ struct genl_ops op2;
+
+ genl_get_cmd_by_index(j, family, &op2);
+ if (op.cmd == op2.cmd)
return -EINVAL;
+ }
}
return 0;
@@ -524,7 +586,7 @@ no_attrs:
return -ENOMEM;
}
info->family = ctx->family;
- info->ops = ops;
+ info->op = *ops;
info->attrs = attrs;
cb->data = info;
@@ -546,7 +608,7 @@ no_attrs:
static int genl_lock_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
{
- const struct genl_ops *ops = genl_dumpit_info(cb)->ops;
+ const struct genl_ops *ops = &genl_dumpit_info(cb)->op;
int rc;
genl_lock();
@@ -558,7 +620,7 @@ static int genl_lock_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
static int genl_lock_done(struct netlink_callback *cb)
{
const struct genl_dumpit_info *info = genl_dumpit_info(cb);
- const struct genl_ops *ops = info->ops;
+ const struct genl_ops *ops = &info->op;
int rc = 0;
if (ops->done) {
@@ -574,7 +636,7 @@ static int genl_lock_done(struct netlink_callback *cb)
static int genl_parallel_done(struct netlink_callback *cb)
{
const struct genl_dumpit_info *info = genl_dumpit_info(cb);
- const struct genl_ops *ops = info->ops;
+ const struct genl_ops *ops = &info->op;
int rc = 0;
if (ops->done)
@@ -682,9 +744,9 @@ static int genl_family_rcv_msg(const struct genl_family *family,
struct nlmsghdr *nlh,
struct netlink_ext_ack *extack)
{
- const struct genl_ops *ops;
struct net *net = sock_net(skb->sk);
struct genlmsghdr *hdr = nlmsg_data(nlh);
+ struct genl_ops op;
int hdrlen;
/* this family doesn't exist in this netns */
@@ -695,24 +757,23 @@ static int genl_family_rcv_msg(const struct genl_family *family,
if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
return -EINVAL;
- ops = genl_get_cmd(hdr->cmd, family);
- if (ops == NULL)
+ if (genl_get_cmd(hdr->cmd, family, &op))
return -EOPNOTSUPP;
- if ((ops->flags & GENL_ADMIN_PERM) &&
+ if ((op.flags & GENL_ADMIN_PERM) &&
!netlink_capable(skb, CAP_NET_ADMIN))
return -EPERM;
- if ((ops->flags & GENL_UNS_ADMIN_PERM) &&
+ if ((op.flags & GENL_UNS_ADMIN_PERM) &&
!netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
return -EPERM;
if ((nlh->nlmsg_flags & NLM_F_DUMP) == NLM_F_DUMP)
return genl_family_rcv_msg_dumpit(family, skb, nlh, extack,
- ops, hdrlen, net);
+ &op, hdrlen, net);
else
return genl_family_rcv_msg_doit(family, skb, nlh, extack,
- ops, hdrlen, net);
+ &op, hdrlen, net);
}
static int genl_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
@@ -765,7 +826,7 @@ static int ctrl_fill_info(const struct genl_family *family, u32 portid, u32 seq,
nla_put_u32(skb, CTRL_ATTR_MAXATTR, family->maxattr))
goto nla_put_failure;
- if (family->n_ops) {
+ if (genl_get_cmd_cnt(family)) {
struct nlattr *nla_ops;
int i;
@@ -773,14 +834,16 @@ static int ctrl_fill_info(const struct genl_family *family, u32 portid, u32 seq,
if (nla_ops == NULL)
goto nla_put_failure;
- for (i = 0; i < family->n_ops; i++) {
+ for (i = 0; i < genl_get_cmd_cnt(family); i++) {
struct nlattr *nest;
- const struct genl_ops *ops = &family->ops[i];
- u32 op_flags = ops->flags;
+ struct genl_ops op;
+ u32 op_flags;
- if (ops->dumpit)
+ genl_get_cmd_by_index(i, family, &op);
+ op_flags = op.flags;
+ if (op.dumpit)
op_flags |= GENL_CMD_CAP_DUMP;
- if (ops->doit)
+ if (op.doit)
op_flags |= GENL_CMD_CAP_DO;
if (family->policy)
op_flags |= GENL_CMD_CAP_HASPOL;
@@ -789,7 +852,7 @@ static int ctrl_fill_info(const struct genl_family *family, u32 portid, u32 seq,
if (nest == NULL)
goto nla_put_failure;
- if (nla_put_u32(skb, CTRL_ATTR_OP_ID, ops->cmd) ||
+ if (nla_put_u32(skb, CTRL_ATTR_OP_ID, op.cmd) ||
nla_put_u32(skb, CTRL_ATTR_OP_FLAGS, op_flags))
goto nla_put_failure;