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-rw-r--r--net/netlink/genetlink.c278
1 files changed, 166 insertions, 112 deletions
diff --git a/net/netlink/genetlink.c b/net/netlink/genetlink.c
index 36e3a86cacf6..7dbc4f732c75 100644
--- a/net/netlink/genetlink.c
+++ b/net/netlink/genetlink.c
@@ -69,16 +69,20 @@ static struct list_head family_ht[GENL_FAM_TAB_SIZE];
* abuses the API and thinks it can statically use group 1.
* That group will typically conflict with other groups that
* any proper users use.
+ * Bit 16 is marked as used since it's used for generic netlink
+ * and the code no longer marks pre-reserved IDs as used.
* Bit 17 is marked as already used since the VFS quota code
* also abused this API and relied on family == group ID, we
* cater to that by giving it a static family and group ID.
*/
-static unsigned long mc_group_start = 0x3 | BIT(GENL_ID_VFS_DQUOT);
+static unsigned long mc_group_start = 0x3 | BIT(GENL_ID_CTRL) |
+ BIT(GENL_ID_VFS_DQUOT);
static unsigned long *mc_groups = &mc_group_start;
static unsigned long mc_groups_longs = 1;
static int genl_ctrl_event(int event, struct genl_family *family,
- struct genl_multicast_group *grp);
+ const struct genl_multicast_group *grp,
+ int grp_id);
static inline unsigned int genl_family_hash(unsigned int id)
{
@@ -144,66 +148,110 @@ static u16 genl_generate_id(void)
return 0;
}
-static struct genl_multicast_group notify_grp;
-
-/**
- * genl_register_mc_group - register a multicast group
- *
- * Registers the specified multicast group and notifies userspace
- * about the new group.
- *
- * Returns 0 on success or a negative error code.
- *
- * @family: The generic netlink family the group shall be registered for.
- * @grp: The group to register, must have a name.
- */
-int genl_register_mc_group(struct genl_family *family,
- struct genl_multicast_group *grp)
+static int genl_allocate_reserve_groups(int n_groups, int *first_id)
{
- int id;
unsigned long *new_groups;
- int err = 0;
+ int start = 0;
+ int i;
+ int id;
+ bool fits;
+
+ do {
+ if (start == 0)
+ id = find_first_zero_bit(mc_groups,
+ mc_groups_longs *
+ BITS_PER_LONG);
+ else
+ id = find_next_zero_bit(mc_groups,
+ mc_groups_longs * BITS_PER_LONG,
+ start);
+
+ fits = true;
+ for (i = id;
+ i < min_t(int, id + n_groups,
+ mc_groups_longs * BITS_PER_LONG);
+ i++) {
+ if (test_bit(i, mc_groups)) {
+ start = i;
+ fits = false;
+ break;
+ }
+ }
- BUG_ON(grp->name[0] == '\0');
- BUG_ON(memchr(grp->name, '\0', GENL_NAMSIZ) == NULL);
+ if (id >= mc_groups_longs * BITS_PER_LONG) {
+ unsigned long new_longs = mc_groups_longs +
+ BITS_TO_LONGS(n_groups);
+ size_t nlen = new_longs * sizeof(unsigned long);
+
+ if (mc_groups == &mc_group_start) {
+ new_groups = kzalloc(nlen, GFP_KERNEL);
+ if (!new_groups)
+ return -ENOMEM;
+ mc_groups = new_groups;
+ *mc_groups = mc_group_start;
+ } else {
+ new_groups = krealloc(mc_groups, nlen,
+ GFP_KERNEL);
+ if (!new_groups)
+ return -ENOMEM;
+ mc_groups = new_groups;
+ for (i = 0; i < BITS_TO_LONGS(n_groups); i++)
+ mc_groups[mc_groups_longs + i] = 0;
+ }
+ mc_groups_longs = new_longs;
+ }
+ } while (!fits);
- genl_lock_all();
+ for (i = id; i < id + n_groups; i++)
+ set_bit(i, mc_groups);
+ *first_id = id;
+ return 0;
+}
+
+static struct genl_family genl_ctrl;
+
+static int genl_validate_assign_mc_groups(struct genl_family *family)
+{
+ int first_id;
+ int n_groups = family->n_mcgrps;
+ int err, i;
+ bool groups_allocated = false;
+
+ if (!n_groups)
+ return 0;
+
+ for (i = 0; i < n_groups; i++) {
+ const struct genl_multicast_group *grp = &family->mcgrps[i];
+
+ if (WARN_ON(grp->name[0] == '\0'))
+ return -EINVAL;
+ if (WARN_ON(memchr(grp->name, '\0', GENL_NAMSIZ) == NULL))
+ return -EINVAL;
+ }
/* special-case our own group and hacks */
- if (grp == &notify_grp)
- id = GENL_ID_CTRL;
- else if (strcmp(family->name, "NET_DM") == 0)
- id = 1;
- else if (strcmp(family->name, "VFS_DQUOT") == 0)
- id = GENL_ID_VFS_DQUOT;
- else
- id = find_first_zero_bit(mc_groups,
- mc_groups_longs * BITS_PER_LONG);
-
-
- if (id >= mc_groups_longs * BITS_PER_LONG) {
- size_t nlen = (mc_groups_longs + 1) * sizeof(unsigned long);
-
- if (mc_groups == &mc_group_start) {
- new_groups = kzalloc(nlen, GFP_KERNEL);
- if (!new_groups) {
- err = -ENOMEM;
- goto out;
- }
- mc_groups = new_groups;
- *mc_groups = mc_group_start;
- } else {
- new_groups = krealloc(mc_groups, nlen, GFP_KERNEL);
- if (!new_groups) {
- err = -ENOMEM;
- goto out;
- }
- mc_groups = new_groups;
- mc_groups[mc_groups_longs] = 0;
- }
- mc_groups_longs++;
+ if (family == &genl_ctrl) {
+ first_id = GENL_ID_CTRL;
+ BUG_ON(n_groups != 1);
+ } else if (strcmp(family->name, "NET_DM") == 0) {
+ first_id = 1;
+ BUG_ON(n_groups != 1);
+ } else if (strcmp(family->name, "VFS_DQUOT") == 0) {
+ first_id = GENL_ID_VFS_DQUOT;
+ BUG_ON(n_groups != 1);
+ } else {
+ groups_allocated = true;
+ err = genl_allocate_reserve_groups(n_groups, &first_id);
+ if (err)
+ return err;
}
+ family->mcgrp_offset = first_id;
+
+ /* if still initializing, can't and don't need to to realloc bitmaps */
+ if (!init_net.genl_sock)
+ return 0;
+
if (family->netnsok) {
struct net *net;
@@ -219,9 +267,7 @@ int genl_register_mc_group(struct genl_family *family,
* number of _possible_ groups has been
* increased on some sockets which is ok.
*/
- rcu_read_unlock();
- netlink_table_ungrab();
- goto out;
+ break;
}
}
rcu_read_unlock();
@@ -229,46 +275,39 @@ int genl_register_mc_group(struct genl_family *family,
} else {
err = netlink_change_ngroups(init_net.genl_sock,
mc_groups_longs * BITS_PER_LONG);
- if (err)
- goto out;
}
- grp->id = id;
- set_bit(id, mc_groups);
- list_add_tail(&grp->list, &family->mcast_groups);
+ if (groups_allocated && err) {
+ for (i = 0; i < family->n_mcgrps; i++)
+ clear_bit(family->mcgrp_offset + i, mc_groups);
+ }
- genl_ctrl_event(CTRL_CMD_NEWMCAST_GRP, family, grp);
- out:
- genl_unlock_all();
return err;
}
-EXPORT_SYMBOL(genl_register_mc_group);
-static void __genl_unregister_mc_group(struct genl_family *family,
- struct genl_multicast_group *grp)
+static void genl_unregister_mc_groups(struct genl_family *family)
{
struct net *net;
+ int i;
netlink_table_grab();
rcu_read_lock();
- for_each_net_rcu(net)
- __netlink_clear_multicast_users(net->genl_sock, grp->id);
+ for_each_net_rcu(net) {
+ for (i = 0; i < family->n_mcgrps; i++)
+ __netlink_clear_multicast_users(
+ net->genl_sock, family->mcgrp_offset + i);
+ }
rcu_read_unlock();
netlink_table_ungrab();
- if (grp->id != 1)
- clear_bit(grp->id, mc_groups);
- list_del(&grp->list);
- genl_ctrl_event(CTRL_CMD_DELMCAST_GRP, family, grp);
- grp->id = 0;
-}
-
-static void genl_unregister_mc_groups(struct genl_family *family)
-{
- struct genl_multicast_group *grp, *tmp;
+ for (i = 0; i < family->n_mcgrps; i++) {
+ int grp_id = family->mcgrp_offset + i;
- list_for_each_entry_safe(grp, tmp, &family->mcast_groups, list)
- __genl_unregister_mc_group(family, grp);
+ if (grp_id != 1)
+ clear_bit(grp_id, mc_groups);
+ genl_ctrl_event(CTRL_CMD_DELMCAST_GRP, family,
+ &family->mcgrps[i], grp_id);
+ }
}
static int genl_validate_ops(struct genl_family *family)
@@ -314,7 +353,7 @@ static int genl_validate_ops(struct genl_family *family)
*/
int __genl_register_family(struct genl_family *family)
{
- int err = -EINVAL;
+ int err = -EINVAL, i;
if (family->id && family->id < GENL_MIN_ID)
goto errout;
@@ -326,8 +365,6 @@ int __genl_register_family(struct genl_family *family)
if (err)
return err;
- INIT_LIST_HEAD(&family->mcast_groups);
-
genl_lock_all();
if (genl_family_find_byname(family->name)) {
@@ -359,10 +396,18 @@ int __genl_register_family(struct genl_family *family)
} else
family->attrbuf = NULL;
+ err = genl_validate_assign_mc_groups(family);
+ if (err)
+ goto errout_locked;
+
list_add_tail(&family->family_list, genl_family_chain(family->id));
genl_unlock_all();
- genl_ctrl_event(CTRL_CMD_NEWFAMILY, family, NULL);
+ /* send all events */
+ genl_ctrl_event(CTRL_CMD_NEWFAMILY, family, NULL, 0);
+ for (i = 0; i < family->n_mcgrps; i++)
+ genl_ctrl_event(CTRL_CMD_NEWMCAST_GRP, family,
+ &family->mcgrps[i], family->mcgrp_offset + i);
return 0;
@@ -398,7 +443,7 @@ int genl_unregister_family(struct genl_family *family)
genl_unlock_all();
kfree(family->attrbuf);
- genl_ctrl_event(CTRL_CMD_DELFAMILY, family, NULL);
+ genl_ctrl_event(CTRL_CMD_DELFAMILY, family, NULL, 0);
return 0;
}
@@ -658,23 +703,26 @@ static int ctrl_fill_info(struct genl_family *family, u32 portid, u32 seq,
nla_nest_end(skb, nla_ops);
}
- if (!list_empty(&family->mcast_groups)) {
- struct genl_multicast_group *grp;
+ if (family->n_mcgrps) {
struct nlattr *nla_grps;
- int idx = 1;
+ int i;
nla_grps = nla_nest_start(skb, CTRL_ATTR_MCAST_GROUPS);
if (nla_grps == NULL)
goto nla_put_failure;
- list_for_each_entry(grp, &family->mcast_groups, list) {
+ for (i = 0; i < family->n_mcgrps; i++) {
struct nlattr *nest;
+ const struct genl_multicast_group *grp;
- nest = nla_nest_start(skb, idx++);
+ grp = &family->mcgrps[i];
+
+ nest = nla_nest_start(skb, i + 1);
if (nest == NULL)
goto nla_put_failure;
- if (nla_put_u32(skb, CTRL_ATTR_MCAST_GRP_ID, grp->id) ||
+ if (nla_put_u32(skb, CTRL_ATTR_MCAST_GRP_ID,
+ family->mcgrp_offset + i) ||
nla_put_string(skb, CTRL_ATTR_MCAST_GRP_NAME,
grp->name))
goto nla_put_failure;
@@ -692,9 +740,9 @@ nla_put_failure:
}
static int ctrl_fill_mcgrp_info(struct genl_family *family,
- struct genl_multicast_group *grp, u32 portid,
- u32 seq, u32 flags, struct sk_buff *skb,
- u8 cmd)
+ const struct genl_multicast_group *grp,
+ int grp_id, u32 portid, u32 seq, u32 flags,
+ struct sk_buff *skb, u8 cmd)
{
void *hdr;
struct nlattr *nla_grps;
@@ -716,7 +764,7 @@ static int ctrl_fill_mcgrp_info(struct genl_family *family,
if (nest == NULL)
goto nla_put_failure;
- if (nla_put_u32(skb, CTRL_ATTR_MCAST_GRP_ID, grp->id) ||
+ if (nla_put_u32(skb, CTRL_ATTR_MCAST_GRP_ID, grp_id) ||
nla_put_string(skb, CTRL_ATTR_MCAST_GRP_NAME,
grp->name))
goto nla_put_failure;
@@ -782,9 +830,10 @@ static struct sk_buff *ctrl_build_family_msg(struct genl_family *family,
return skb;
}
-static struct sk_buff *ctrl_build_mcgrp_msg(struct genl_family *family,
- struct genl_multicast_group *grp,
- u32 portid, int seq, u8 cmd)
+static struct sk_buff *
+ctrl_build_mcgrp_msg(struct genl_family *family,
+ const struct genl_multicast_group *grp,
+ int grp_id, u32 portid, int seq, u8 cmd)
{
struct sk_buff *skb;
int err;
@@ -793,7 +842,8 @@ static struct sk_buff *ctrl_build_mcgrp_msg(struct genl_family *family,
if (skb == NULL)
return ERR_PTR(-ENOBUFS);
- err = ctrl_fill_mcgrp_info(family, grp, portid, seq, 0, skb, cmd);
+ err = ctrl_fill_mcgrp_info(family, grp, grp_id, portid,
+ seq, 0, skb, cmd);
if (err < 0) {
nlmsg_free(skb);
return ERR_PTR(err);
@@ -856,7 +906,8 @@ static int ctrl_getfamily(struct sk_buff *skb, struct genl_info *info)
}
static int genl_ctrl_event(int event, struct genl_family *family,
- struct genl_multicast_group *grp)
+ const struct genl_multicast_group *grp,
+ int grp_id)
{
struct sk_buff *msg;
@@ -873,7 +924,7 @@ static int genl_ctrl_event(int event, struct genl_family *family,
case CTRL_CMD_NEWMCAST_GRP:
case CTRL_CMD_DELMCAST_GRP:
BUG_ON(!grp);
- msg = ctrl_build_mcgrp_msg(family, grp, 0, 0, event);
+ msg = ctrl_build_mcgrp_msg(family, grp, grp_id, 0, 0, event);
break;
default:
return -EINVAL;
@@ -884,11 +935,11 @@ static int genl_ctrl_event(int event, struct genl_family *family,
if (!family->netnsok) {
genlmsg_multicast_netns(&genl_ctrl, &init_net, msg, 0,
- GENL_ID_CTRL, GFP_KERNEL);
+ 0, GFP_KERNEL);
} else {
rcu_read_lock();
genlmsg_multicast_allns(&genl_ctrl, msg, 0,
- GENL_ID_CTRL, GFP_ATOMIC);
+ 0, GFP_ATOMIC);
rcu_read_unlock();
}
@@ -904,8 +955,8 @@ static struct genl_ops genl_ctrl_ops[] = {
},
};
-static struct genl_multicast_group notify_grp = {
- .name = "notify",
+static struct genl_multicast_group genl_ctrl_groups[] = {
+ { .name = "notify", },
};
static int __net_init genl_pernet_init(struct net *net)
@@ -945,7 +996,8 @@ static int __init genl_init(void)
for (i = 0; i < GENL_FAM_TAB_SIZE; i++)
INIT_LIST_HEAD(&family_ht[i]);
- err = genl_register_family_with_ops(&genl_ctrl, genl_ctrl_ops);
+ err = genl_register_family_with_ops_groups(&genl_ctrl, genl_ctrl_ops,
+ genl_ctrl_groups);
if (err < 0)
goto problem;
@@ -953,10 +1005,6 @@ static int __init genl_init(void)
if (err)
goto problem;
- err = genl_register_mc_group(&genl_ctrl, &notify_grp);
- if (err < 0)
- goto problem;
-
return 0;
problem:
@@ -997,6 +1045,9 @@ static int genlmsg_mcast(struct sk_buff *skb, u32 portid, unsigned long group,
int genlmsg_multicast_allns(struct genl_family *family, struct sk_buff *skb,
u32 portid, unsigned int group, gfp_t flags)
{
+ if (group >= family->n_mcgrps)
+ return -EINVAL;
+ group = family->mcgrp_offset + group;
return genlmsg_mcast(skb, portid, group, flags);
}
EXPORT_SYMBOL(genlmsg_multicast_allns);
@@ -1011,6 +1062,9 @@ void genl_notify(struct genl_family *family,
if (nlh)
report = nlmsg_report(nlh);
+ if (group >= family->n_mcgrps)
+ return;
+ group = family->mcgrp_offset + group;
nlmsg_notify(sk, skb, portid, group, report, flags);
}
EXPORT_SYMBOL(genl_notify);
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-29 15:33:43 +0000