#define INITIAL_POLICIES_ALLOC 10
-struct nl_policy_dump {
+struct netlink_policy_dump_state {
unsigned int policy_idx;
unsigned int attr_idx;
unsigned int n_alloc;
} policies[];
};
-static int add_policy(struct nl_policy_dump **statep,
+static int add_policy(struct netlink_policy_dump_state **statep,
const struct nla_policy *policy,
unsigned int maxtype)
{
- struct nl_policy_dump *state = *statep;
+ struct netlink_policy_dump_state *state = *statep;
unsigned int n_alloc, i;
if (!policy || !maxtype)
return 0;
for (i = 0; i < state->n_alloc; i++) {
- if (state->policies[i].policy == policy)
+ if (state->policies[i].policy == policy &&
+ state->policies[i].maxtype == maxtype)
return 0;
if (!state->policies[i].policy) {
return 0;
}
-static unsigned int get_policy_idx(struct nl_policy_dump *state,
- const struct nla_policy *policy)
+/**
+ * netlink_policy_dump_get_policy_idx - retrieve policy index
+ * @state: the policy dump state
+ * @policy: the policy to find
+ * @maxtype: the policy's maxattr
+ *
+ * Returns: the index of the given policy in the dump state
+ *
+ * Call this to find a policy index when you've added multiple and e.g.
+ * need to tell userspace which command has which policy (by index).
+ *
+ * Note: this will WARN and return 0 if the policy isn't found, which
+ * means it wasn't added in the first place, which would be an
+ * internal consistency bug.
+ */
+int netlink_policy_dump_get_policy_idx(struct netlink_policy_dump_state *state,
+ const struct nla_policy *policy,
+ unsigned int maxtype)
{
unsigned int i;
+ if (WARN_ON(!policy || !maxtype))
+ return 0;
+
for (i = 0; i < state->n_alloc; i++) {
- if (state->policies[i].policy == policy)
+ if (state->policies[i].policy == policy &&
+ state->policies[i].maxtype == maxtype)
return i;
}
- WARN_ON_ONCE(1);
- return -1;
+ WARN_ON(1);
+ return 0;
+}
+
+static struct netlink_policy_dump_state *alloc_state(void)
+{
+ struct netlink_policy_dump_state *state;
+
+ state = kzalloc(struct_size(state, policies, INITIAL_POLICIES_ALLOC),
+ GFP_KERNEL);
+ if (!state)
+ return ERR_PTR(-ENOMEM);
+ state->n_alloc = INITIAL_POLICIES_ALLOC;
+
+ return state;
}
-int netlink_policy_dump_start(const struct nla_policy *policy,
- unsigned int maxtype,
- unsigned long *_state)
+/**
+ * netlink_policy_dump_add_policy - add a policy to the dump
+ * @pstate: state to add to, may be reallocated, must be %NULL the first time
+ * @policy: the new policy to add to the dump
+ * @maxtype: the new policy's max attr type
+ *
+ * Returns: 0 on success, a negative error code otherwise.
+ *
+ * Call this to allocate a policy dump state, and to add policies to it. This
+ * should be called from the dump start() callback.
+ *
+ * Note: on failures, any previously allocated state is freed.
+ */
+int netlink_policy_dump_add_policy(struct netlink_policy_dump_state **pstate,
+ const struct nla_policy *policy,
+ unsigned int maxtype)
{
- struct nl_policy_dump *state;
+ struct netlink_policy_dump_state *state = *pstate;
unsigned int policy_idx;
int err;
- /* also returns 0 if "*_state" is our ERR_PTR() end marker */
- if (*_state)
- return 0;
+ if (!state) {
+ state = alloc_state();
+ if (IS_ERR(state))
+ return PTR_ERR(state);
+ }
/*
* walk the policies and nested ones first, and build
* a linear list of them.
*/
- state = kzalloc(struct_size(state, policies, INITIAL_POLICIES_ALLOC),
- GFP_KERNEL);
- if (!state)
- return -ENOMEM;
- state->n_alloc = INITIAL_POLICIES_ALLOC;
-
err = add_policy(&state, policy, maxtype);
if (err)
return err;
}
}
- *_state = (unsigned long)state;
-
+ *pstate = state;
return 0;
}
-static bool netlink_policy_dump_finished(struct nl_policy_dump *state)
+static bool
+netlink_policy_dump_finished(struct netlink_policy_dump_state *state)
{
return state->policy_idx >= state->n_alloc ||
!state->policies[state->policy_idx].policy;
}
-bool netlink_policy_dump_loop(unsigned long *_state)
+/**
+ * netlink_policy_dump_loop - dumping loop indicator
+ * @state: the policy dump state
+ *
+ * Returns: %true if the dump continues, %false otherwise
+ *
+ * Note: this frees the dump state when finishing
+ */
+bool netlink_policy_dump_loop(struct netlink_policy_dump_state *state)
{
- struct nl_policy_dump *state = (void *)*_state;
+ return !netlink_policy_dump_finished(state);
+}
- if (IS_ERR(state))
- return false;
+int netlink_policy_dump_attr_size_estimate(const struct nla_policy *pt)
+{
+ /* nested + type */
+ int common = 2 * nla_attr_size(sizeof(u32));
- if (netlink_policy_dump_finished(state)) {
- kfree(state);
- /* store end marker instead of freed state */
- *_state = (unsigned long)ERR_PTR(-ENOENT);
- return false;
+ switch (pt->type) {
+ case NLA_UNSPEC:
+ case NLA_REJECT:
+ /* these actually don't need any space */
+ return 0;
+ case NLA_NESTED:
+ case NLA_NESTED_ARRAY:
+ /* common, policy idx, policy maxattr */
+ return common + 2 * nla_attr_size(sizeof(u32));
+ case NLA_U8:
+ case NLA_U16:
+ case NLA_U32:
+ case NLA_U64:
+ case NLA_MSECS:
+ case NLA_S8:
+ case NLA_S16:
+ case NLA_S32:
+ case NLA_S64:
+ /* maximum is common, u64 min/max with padding */
+ return common +
+ 2 * (nla_attr_size(0) + nla_attr_size(sizeof(u64)));
+ case NLA_BITFIELD32:
+ return common + nla_attr_size(sizeof(u32));
+ case NLA_STRING:
+ case NLA_NUL_STRING:
+ case NLA_BINARY:
+ /* maximum is common, u32 min-length/max-length */
+ return common + 2 * nla_attr_size(sizeof(u32));
+ case NLA_FLAG:
+ return common;
}
- return true;
+ /* this should then cause a warning later */
+ return 0;
}
-int netlink_policy_dump_write(struct sk_buff *skb, unsigned long _state)
+static int
+__netlink_policy_dump_write_attr(struct netlink_policy_dump_state *state,
+ struct sk_buff *skb,
+ const struct nla_policy *pt,
+ int nestattr)
{
- struct nl_policy_dump *state = (void *)_state;
- const struct nla_policy *pt;
- struct nlattr *policy, *attr;
+ int estimate = netlink_policy_dump_attr_size_estimate(pt);
enum netlink_attribute_type type;
- bool again;
-
-send_attribute:
- again = false;
+ struct nlattr *attr;
- pt = &state->policies[state->policy_idx].policy[state->attr_idx];
-
- policy = nla_nest_start(skb, state->policy_idx);
- if (!policy)
- return -ENOBUFS;
-
- attr = nla_nest_start(skb, state->attr_idx);
+ attr = nla_nest_start(skb, nestattr);
if (!attr)
- goto nla_put_failure;
+ return -ENOBUFS;
switch (pt->type) {
default:
case NLA_UNSPEC:
case NLA_REJECT:
/* skip - use NLA_MIN_LEN to advertise such */
- nla_nest_cancel(skb, policy);
- again = true;
- goto next;
+ nla_nest_cancel(skb, attr);
+ return -ENODATA;
case NLA_NESTED:
type = NL_ATTR_TYPE_NESTED;
fallthrough;
case NLA_NESTED_ARRAY:
if (pt->type == NLA_NESTED_ARRAY)
type = NL_ATTR_TYPE_NESTED_ARRAY;
- if (pt->nested_policy && pt->len &&
+ if (state && pt->nested_policy && pt->len &&
(nla_put_u32(skb, NL_POLICY_TYPE_ATTR_POLICY_IDX,
- get_policy_idx(state, pt->nested_policy)) ||
+ netlink_policy_dump_get_policy_idx(state,
+ pt->nested_policy,
+ pt->len)) ||
nla_put_u32(skb, NL_POLICY_TYPE_ATTR_POLICY_MAXTYPE,
pt->len)))
goto nla_put_failure;
else
type = NL_ATTR_TYPE_U64;
+ if (pt->validation_type == NLA_VALIDATE_MASK) {
+ if (nla_put_u64_64bit(skb, NL_POLICY_TYPE_ATTR_MASK,
+ pt->mask,
+ NL_POLICY_TYPE_ATTR_PAD))
+ goto nla_put_failure;
+ break;
+ }
+
nla_get_range_unsigned(pt, &range);
if (nla_put_u64_64bit(skb, NL_POLICY_TYPE_ATTR_MIN_VALUE_U,
pt->bitfield32_valid))
goto nla_put_failure;
break;
- case NLA_EXACT_LEN:
- type = NL_ATTR_TYPE_BINARY;
- if (nla_put_u32(skb, NL_POLICY_TYPE_ATTR_MIN_LENGTH, pt->len) ||
- nla_put_u32(skb, NL_POLICY_TYPE_ATTR_MAX_LENGTH, pt->len))
- goto nla_put_failure;
- break;
case NLA_STRING:
case NLA_NUL_STRING:
case NLA_BINARY:
type = NL_ATTR_TYPE_NUL_STRING;
else
type = NL_ATTR_TYPE_BINARY;
- if (pt->len && nla_put_u32(skb, NL_POLICY_TYPE_ATTR_MAX_LENGTH,
- pt->len))
- goto nla_put_failure;
- break;
- case NLA_MIN_LEN:
- type = NL_ATTR_TYPE_BINARY;
- if (nla_put_u32(skb, NL_POLICY_TYPE_ATTR_MIN_LENGTH, pt->len))
+
+ if (pt->validation_type == NLA_VALIDATE_RANGE ||
+ pt->validation_type == NLA_VALIDATE_RANGE_WARN_TOO_LONG) {
+ struct netlink_range_validation range;
+
+ nla_get_range_unsigned(pt, &range);
+
+ if (range.min &&
+ nla_put_u32(skb, NL_POLICY_TYPE_ATTR_MIN_LENGTH,
+ range.min))
+ goto nla_put_failure;
+
+ if (range.max < U16_MAX &&
+ nla_put_u32(skb, NL_POLICY_TYPE_ATTR_MAX_LENGTH,
+ range.max))
+ goto nla_put_failure;
+ } else if (pt->len &&
+ nla_put_u32(skb, NL_POLICY_TYPE_ATTR_MAX_LENGTH,
+ pt->len)) {
goto nla_put_failure;
+ }
break;
case NLA_FLAG:
type = NL_ATTR_TYPE_FLAG;
if (nla_put_u32(skb, NL_POLICY_TYPE_ATTR_TYPE, type))
goto nla_put_failure;
- /* finish and move state to next attribute */
nla_nest_end(skb, attr);
+ WARN_ON(attr->nla_len > estimate);
+
+ return 0;
+nla_put_failure:
+ nla_nest_cancel(skb, attr);
+ return -ENOBUFS;
+}
+
+/**
+ * netlink_policy_dump_write_attr - write a given attribute policy
+ * @skb: the message skb to write to
+ * @pt: the attribute's policy
+ * @nestattr: the nested attribute ID to use
+ *
+ * Returns: 0 on success, an error code otherwise; -%ENODATA is
+ * special, indicating that there's no policy data and
+ * the attribute is generally rejected.
+ */
+int netlink_policy_dump_write_attr(struct sk_buff *skb,
+ const struct nla_policy *pt,
+ int nestattr)
+{
+ return __netlink_policy_dump_write_attr(NULL, skb, pt, nestattr);
+}
+
+/**
+ * netlink_policy_dump_write - write current policy dump attributes
+ * @skb: the message skb to write to
+ * @state: the policy dump state
+ *
+ * Returns: 0 on success, an error code otherwise
+ */
+int netlink_policy_dump_write(struct sk_buff *skb,
+ struct netlink_policy_dump_state *state)
+{
+ const struct nla_policy *pt;
+ struct nlattr *policy;
+ bool again;
+ int err;
+
+send_attribute:
+ again = false;
+
+ pt = &state->policies[state->policy_idx].policy[state->attr_idx];
+
+ policy = nla_nest_start(skb, state->policy_idx);
+ if (!policy)
+ return -ENOBUFS;
+
+ err = __netlink_policy_dump_write_attr(state, skb, pt, state->attr_idx);
+ if (err == -ENODATA) {
+ nla_nest_cancel(skb, policy);
+ again = true;
+ goto next;
+ } else if (err) {
+ goto nla_put_failure;
+ }
+
+ /* finish and move state to next attribute */
nla_nest_end(skb, policy);
next:
nla_nest_cancel(skb, policy);
return -ENOBUFS;
}
+
+/**
+ * netlink_policy_dump_free - free policy dump state
+ * @state: the policy dump state to free
+ *
+ * Call this from the done() method to ensure dump state is freed.
+ */
+void netlink_policy_dump_free(struct netlink_policy_dump_state *state)
+{
+ kfree(state);
+}
projects / linux-2.6-microblaze.git / blobdiff