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- /*
- * NETLINK Generic Netlink Family
- *
- * Authors: Jamal Hadi Salim
- * Thomas Graf <tgraf@suug.ch>
- * Johannes Berg <johannes@sipsolutions.net>
- */
- #include <linux/module.h>
- #include <linux/kernel.h>
- #include <linux/slab.h>
- #include <linux/errno.h>
- #include <linux/types.h>
- #include <linux/socket.h>
- #include <linux/string.h>
- #include <linux/skbuff.h>
- #include <linux/mutex.h>
- #include <linux/bitmap.h>
- #include <linux/rwsem.h>
- #include <net/sock.h>
- #include <net/genetlink.h>
- static DEFINE_MUTEX(genl_mutex); /* serialization of message processing */
- static DECLARE_RWSEM(cb_lock);
- atomic_t genl_sk_destructing_cnt = ATOMIC_INIT(0);
- DECLARE_WAIT_QUEUE_HEAD(genl_sk_destructing_waitq);
- void genl_lock(void)
- {
- mutex_lock(&genl_mutex);
- }
- EXPORT_SYMBOL(genl_lock);
- void genl_unlock(void)
- {
- mutex_unlock(&genl_mutex);
- }
- EXPORT_SYMBOL(genl_unlock);
- #ifdef CONFIG_LOCKDEP
- bool lockdep_genl_is_held(void)
- {
- return lockdep_is_held(&genl_mutex);
- }
- EXPORT_SYMBOL(lockdep_genl_is_held);
- #endif
- static void genl_lock_all(void)
- {
- down_write(&cb_lock);
- genl_lock();
- }
- static void genl_unlock_all(void)
- {
- genl_unlock();
- up_write(&cb_lock);
- }
- #define GENL_FAM_TAB_SIZE 16
- #define GENL_FAM_TAB_MASK (GENL_FAM_TAB_SIZE - 1)
- static struct list_head family_ht[GENL_FAM_TAB_SIZE];
- /*
- * Bitmap of multicast groups that are currently in use.
- *
- * To avoid an allocation at boot of just one unsigned long,
- * declare it global instead.
- * Bit 0 is marked as already used since group 0 is invalid.
- * Bit 1 is marked as already used since the drop-monitor code
- * 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.
- * Bit 18 is marked as already used since the PMCRAID driver
- * did the same thing as the VFS quota code (maybe copied?)
- */
- static unsigned long mc_group_start = 0x3 | BIT(GENL_ID_CTRL) |
- BIT(GENL_ID_VFS_DQUOT) |
- BIT(GENL_ID_PMCRAID);
- 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,
- const struct genl_multicast_group *grp,
- int grp_id);
- static inline unsigned int genl_family_hash(unsigned int id)
- {
- return id & GENL_FAM_TAB_MASK;
- }
- static inline struct list_head *genl_family_chain(unsigned int id)
- {
- return &family_ht[genl_family_hash(id)];
- }
- static struct genl_family *genl_family_find_byid(unsigned int id)
- {
- struct genl_family *f;
- list_for_each_entry(f, genl_family_chain(id), family_list)
- if (f->id == id)
- return f;
- return NULL;
- }
- static struct genl_family *genl_family_find_byname(char *name)
- {
- struct genl_family *f;
- int i;
- for (i = 0; i < GENL_FAM_TAB_SIZE; i++)
- list_for_each_entry(f, genl_family_chain(i), family_list)
- if (strcmp(f->name, name) == 0)
- return f;
- return NULL;
- }
- static const struct genl_ops *genl_get_cmd(u8 cmd, struct genl_family *family)
- {
- int i;
- for (i = 0; i < family->n_ops; i++)
- if (family->ops[i].cmd == cmd)
- return &family->ops[i];
- return NULL;
- }
- /* Of course we are going to have problems once we hit
- * 2^16 alive types, but that can only happen by year 2K
- */
- static u16 genl_generate_id(void)
- {
- static u16 id_gen_idx = GENL_MIN_ID;
- int i;
- for (i = 0; i <= GENL_MAX_ID - GENL_MIN_ID; i++) {
- if (id_gen_idx != GENL_ID_VFS_DQUOT &&
- id_gen_idx != GENL_ID_PMCRAID &&
- !genl_family_find_byid(id_gen_idx))
- return id_gen_idx;
- if (++id_gen_idx > GENL_MAX_ID)
- id_gen_idx = GENL_MIN_ID;
- }
- return 0;
- }
- static int genl_allocate_reserve_groups(int n_groups, int *first_id)
- {
- unsigned long *new_groups;
- 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;
- }
- }
- 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);
- 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 = 0, 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 (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 (family->id == GENL_ID_VFS_DQUOT) {
- first_id = GENL_ID_VFS_DQUOT;
- BUG_ON(n_groups != 1);
- } else if (family->id == GENL_ID_PMCRAID) {
- first_id = GENL_ID_PMCRAID;
- 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;
- netlink_table_grab();
- rcu_read_lock();
- for_each_net_rcu(net) {
- err = __netlink_change_ngroups(net->genl_sock,
- mc_groups_longs * BITS_PER_LONG);
- if (err) {
- /*
- * No need to roll back, can only fail if
- * memory allocation fails and then the
- * number of _possible_ groups has been
- * increased on some sockets which is ok.
- */
- break;
- }
- }
- rcu_read_unlock();
- netlink_table_ungrab();
- } else {
- err = netlink_change_ngroups(init_net.genl_sock,
- mc_groups_longs * BITS_PER_LONG);
- }
- if (groups_allocated && err) {
- for (i = 0; i < family->n_mcgrps; i++)
- clear_bit(family->mcgrp_offset + i, mc_groups);
- }
- return err;
- }
- 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) {
- 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();
- for (i = 0; i < family->n_mcgrps; i++) {
- int grp_id = family->mcgrp_offset + i;
- 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(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))
- return -EINVAL;
- if (!n_ops)
- return 0;
- for (i = 0; i < n_ops; i++) {
- if (ops[i].dumpit == NULL && ops[i].doit == NULL)
- return -EINVAL;
- for (j = i + 1; j < n_ops; j++)
- if (ops[i].cmd == ops[j].cmd)
- return -EINVAL;
- }
- return 0;
- }
- /**
- * __genl_register_family - register a generic netlink family
- * @family: generic netlink family
- *
- * Registers the specified family after validating it first. Only one
- * family may be registered with the same family name or identifier.
- * The family id may equal GENL_ID_GENERATE causing an unique id to
- * be automatically generated and assigned.
- *
- * The family's ops array must already be assigned, you can use the
- * genl_register_family_with_ops() helper function.
- *
- * Return 0 on success or a negative error code.
- */
- int __genl_register_family(struct genl_family *family)
- {
- int err = -EINVAL, i;
- if (family->id && family->id < GENL_MIN_ID)
- goto errout;
- if (family->id > GENL_MAX_ID)
- goto errout;
- err = genl_validate_ops(family);
- if (err)
- return err;
- genl_lock_all();
- if (genl_family_find_byname(family->name)) {
- err = -EEXIST;
- goto errout_locked;
- }
- if (family->id == GENL_ID_GENERATE) {
- u16 newid = genl_generate_id();
- if (!newid) {
- err = -ENOMEM;
- goto errout_locked;
- }
- family->id = newid;
- } else if (genl_family_find_byid(family->id)) {
- err = -EEXIST;
- goto errout_locked;
- }
- if (family->maxattr && !family->parallel_ops) {
- family->attrbuf = kmalloc((family->maxattr+1) *
- sizeof(struct nlattr *), GFP_KERNEL);
- if (family->attrbuf == NULL) {
- err = -ENOMEM;
- goto errout_locked;
- }
- } 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();
- /* 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;
- errout_locked:
- genl_unlock_all();
- errout:
- return err;
- }
- EXPORT_SYMBOL(__genl_register_family);
- /**
- * genl_unregister_family - unregister generic netlink family
- * @family: generic netlink family
- *
- * Unregisters the specified family.
- *
- * Returns 0 on success or a negative error code.
- */
- int genl_unregister_family(struct genl_family *family)
- {
- struct genl_family *rc;
- genl_lock_all();
- list_for_each_entry(rc, genl_family_chain(family->id), family_list) {
- if (family->id != rc->id || strcmp(rc->name, family->name))
- continue;
- genl_unregister_mc_groups(family);
- list_del(&rc->family_list);
- family->n_ops = 0;
- up_write(&cb_lock);
- wait_event(genl_sk_destructing_waitq,
- atomic_read(&genl_sk_destructing_cnt) == 0);
- genl_unlock();
- kfree(family->attrbuf);
- genl_ctrl_event(CTRL_CMD_DELFAMILY, family, NULL, 0);
- return 0;
- }
- genl_unlock_all();
- return -ENOENT;
- }
- EXPORT_SYMBOL(genl_unregister_family);
- /**
- * genlmsg_new_unicast - Allocate generic netlink message for unicast
- * @payload: size of the message payload
- * @info: information on destination
- * @flags: the type of memory to allocate
- *
- * Allocates a new sk_buff large enough to cover the specified payload
- * plus required Netlink headers. Will check receiving socket for
- * memory mapped i/o capability and use it if enabled. Will fall back
- * to non-mapped skb if message size exceeds the frame size of the ring.
- */
- struct sk_buff *genlmsg_new_unicast(size_t payload, struct genl_info *info,
- gfp_t flags)
- {
- size_t len = nlmsg_total_size(genlmsg_total_size(payload));
- return netlink_alloc_skb(info->dst_sk, len, info->snd_portid, flags);
- }
- EXPORT_SYMBOL_GPL(genlmsg_new_unicast);
- /**
- * genlmsg_put - Add generic netlink header to netlink message
- * @skb: socket buffer holding the message
- * @portid: netlink portid the message is addressed to
- * @seq: sequence number (usually the one of the sender)
- * @family: generic netlink family
- * @flags: netlink message flags
- * @cmd: generic netlink command
- *
- * Returns pointer to user specific header
- */
- void *genlmsg_put(struct sk_buff *skb, u32 portid, u32 seq,
- struct genl_family *family, int flags, u8 cmd)
- {
- struct nlmsghdr *nlh;
- struct genlmsghdr *hdr;
- nlh = nlmsg_put(skb, portid, seq, family->id, GENL_HDRLEN +
- family->hdrsize, flags);
- if (nlh == NULL)
- return NULL;
- hdr = nlmsg_data(nlh);
- hdr->cmd = cmd;
- hdr->version = family->version;
- hdr->reserved = 0;
- return (char *) hdr + GENL_HDRLEN;
- }
- EXPORT_SYMBOL(genlmsg_put);
- static int genl_lock_start(struct netlink_callback *cb)
- {
- /* our ops are always const - netlink API doesn't propagate that */
- const struct genl_ops *ops = cb->data;
- int rc = 0;
- if (ops->start) {
- genl_lock();
- rc = ops->start(cb);
- genl_unlock();
- }
- return rc;
- }
- static int genl_lock_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
- {
- /* our ops are always const - netlink API doesn't propagate that */
- const struct genl_ops *ops = cb->data;
- int rc;
- genl_lock();
- rc = ops->dumpit(skb, cb);
- genl_unlock();
- return rc;
- }
- static int genl_lock_done(struct netlink_callback *cb)
- {
- /* our ops are always const - netlink API doesn't propagate that */
- const struct genl_ops *ops = cb->data;
- int rc = 0;
- if (ops->done) {
- genl_lock();
- rc = ops->done(cb);
- genl_unlock();
- }
- return rc;
- }
- static int genl_family_rcv_msg(struct genl_family *family,
- struct sk_buff *skb,
- struct nlmsghdr *nlh)
- {
- const struct genl_ops *ops;
- struct net *net = sock_net(skb->sk);
- struct genl_info info;
- struct genlmsghdr *hdr = nlmsg_data(nlh);
- struct nlattr **attrbuf;
- int hdrlen, err;
- /* this family doesn't exist in this netns */
- if (!family->netnsok && !net_eq(net, &init_net))
- return -ENOENT;
- hdrlen = GENL_HDRLEN + family->hdrsize;
- if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
- return -EINVAL;
- ops = genl_get_cmd(hdr->cmd, family);
- if (ops == NULL)
- return -EOPNOTSUPP;
- if ((ops->flags & GENL_ADMIN_PERM) &&
- !netlink_capable(skb, CAP_NET_ADMIN))
- return -EPERM;
- if ((nlh->nlmsg_flags & NLM_F_DUMP) == NLM_F_DUMP) {
- int rc;
- if (ops->dumpit == NULL)
- return -EOPNOTSUPP;
- if (!family->parallel_ops) {
- struct netlink_dump_control c = {
- .module = family->module,
- /* we have const, but the netlink API doesn't */
- .data = (void *)ops,
- .start = genl_lock_start,
- .dump = genl_lock_dumpit,
- .done = genl_lock_done,
- };
- genl_unlock();
- rc = __netlink_dump_start(net->genl_sock, skb, nlh, &c);
- genl_lock();
- } else {
- struct netlink_dump_control c = {
- .module = family->module,
- .start = ops->start,
- .dump = ops->dumpit,
- .done = ops->done,
- };
- rc = __netlink_dump_start(net->genl_sock, skb, nlh, &c);
- }
- return rc;
- }
- if (ops->doit == NULL)
- return -EOPNOTSUPP;
- if (family->maxattr && family->parallel_ops) {
- attrbuf = kmalloc((family->maxattr+1) *
- sizeof(struct nlattr *), GFP_KERNEL);
- if (attrbuf == NULL)
- return -ENOMEM;
- } else
- attrbuf = family->attrbuf;
- if (attrbuf) {
- err = nlmsg_parse(nlh, hdrlen, attrbuf, family->maxattr,
- ops->policy);
- if (err < 0)
- goto out;
- }
- info.snd_seq = nlh->nlmsg_seq;
- info.snd_portid = NETLINK_CB(skb).portid;
- info.nlhdr = nlh;
- info.genlhdr = nlmsg_data(nlh);
- info.userhdr = nlmsg_data(nlh) + GENL_HDRLEN;
- info.attrs = attrbuf;
- info.dst_sk = skb->sk;
- genl_info_net_set(&info, net);
- memset(&info.user_ptr, 0, sizeof(info.user_ptr));
- if (family->pre_doit) {
- err = family->pre_doit(ops, skb, &info);
- if (err)
- goto out;
- }
- err = ops->doit(skb, &info);
- if (family->post_doit)
- family->post_doit(ops, skb, &info);
- out:
- if (family->parallel_ops)
- kfree(attrbuf);
- return err;
- }
- static int genl_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
- {
- struct genl_family *family;
- int err;
- family = genl_family_find_byid(nlh->nlmsg_type);
- if (family == NULL)
- return -ENOENT;
- if (!family->parallel_ops)
- genl_lock();
- err = genl_family_rcv_msg(family, skb, nlh);
- if (!family->parallel_ops)
- genl_unlock();
- return err;
- }
- static void genl_rcv(struct sk_buff *skb)
- {
- down_read(&cb_lock);
- netlink_rcv_skb(skb, &genl_rcv_msg);
- up_read(&cb_lock);
- }
- /**************************************************************************
- * Controller
- **************************************************************************/
- static struct genl_family genl_ctrl = {
- .id = GENL_ID_CTRL,
- .name = "nlctrl",
- .version = 0x2,
- .maxattr = CTRL_ATTR_MAX,
- .netnsok = true,
- };
- static int ctrl_fill_info(struct genl_family *family, u32 portid, u32 seq,
- u32 flags, struct sk_buff *skb, u8 cmd)
- {
- void *hdr;
- hdr = genlmsg_put(skb, portid, seq, &genl_ctrl, flags, cmd);
- if (hdr == NULL)
- return -1;
- if (nla_put_string(skb, CTRL_ATTR_FAMILY_NAME, family->name) ||
- nla_put_u16(skb, CTRL_ATTR_FAMILY_ID, family->id) ||
- nla_put_u32(skb, CTRL_ATTR_VERSION, family->version) ||
- nla_put_u32(skb, CTRL_ATTR_HDRSIZE, family->hdrsize) ||
- nla_put_u32(skb, CTRL_ATTR_MAXATTR, family->maxattr))
- goto nla_put_failure;
- if (family->n_ops) {
- struct nlattr *nla_ops;
- int i;
- nla_ops = nla_nest_start(skb, CTRL_ATTR_OPS);
- if (nla_ops == NULL)
- goto nla_put_failure;
- for (i = 0; i < family->n_ops; i++) {
- struct nlattr *nest;
- const struct genl_ops *ops = &family->ops[i];
- u32 op_flags = ops->flags;
- if (ops->dumpit)
- op_flags |= GENL_CMD_CAP_DUMP;
- if (ops->doit)
- op_flags |= GENL_CMD_CAP_DO;
- if (ops->policy)
- op_flags |= GENL_CMD_CAP_HASPOL;
- nest = nla_nest_start(skb, i + 1);
- if (nest == NULL)
- goto nla_put_failure;
- if (nla_put_u32(skb, CTRL_ATTR_OP_ID, ops->cmd) ||
- nla_put_u32(skb, CTRL_ATTR_OP_FLAGS, op_flags))
- goto nla_put_failure;
- nla_nest_end(skb, nest);
- }
- nla_nest_end(skb, nla_ops);
- }
- if (family->n_mcgrps) {
- struct nlattr *nla_grps;
- int i;
- nla_grps = nla_nest_start(skb, CTRL_ATTR_MCAST_GROUPS);
- if (nla_grps == NULL)
- goto nla_put_failure;
- for (i = 0; i < family->n_mcgrps; i++) {
- struct nlattr *nest;
- const struct genl_multicast_group *grp;
- 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,
- family->mcgrp_offset + i) ||
- nla_put_string(skb, CTRL_ATTR_MCAST_GRP_NAME,
- grp->name))
- goto nla_put_failure;
- nla_nest_end(skb, nest);
- }
- nla_nest_end(skb, nla_grps);
- }
- genlmsg_end(skb, hdr);
- return 0;
- nla_put_failure:
- genlmsg_cancel(skb, hdr);
- return -EMSGSIZE;
- }
- static int ctrl_fill_mcgrp_info(struct genl_family *family,
- 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;
- struct nlattr *nest;
- hdr = genlmsg_put(skb, portid, seq, &genl_ctrl, flags, cmd);
- if (hdr == NULL)
- return -1;
- if (nla_put_string(skb, CTRL_ATTR_FAMILY_NAME, family->name) ||
- nla_put_u16(skb, CTRL_ATTR_FAMILY_ID, family->id))
- goto nla_put_failure;
- nla_grps = nla_nest_start(skb, CTRL_ATTR_MCAST_GROUPS);
- if (nla_grps == NULL)
- goto nla_put_failure;
- nest = nla_nest_start(skb, 1);
- if (nest == NULL)
- goto nla_put_failure;
- 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;
- nla_nest_end(skb, nest);
- nla_nest_end(skb, nla_grps);
- genlmsg_end(skb, hdr);
- return 0;
- nla_put_failure:
- genlmsg_cancel(skb, hdr);
- return -EMSGSIZE;
- }
- static int ctrl_dumpfamily(struct sk_buff *skb, struct netlink_callback *cb)
- {
- int i, n = 0;
- struct genl_family *rt;
- struct net *net = sock_net(skb->sk);
- int chains_to_skip = cb->args[0];
- int fams_to_skip = cb->args[1];
- for (i = chains_to_skip; i < GENL_FAM_TAB_SIZE; i++) {
- n = 0;
- list_for_each_entry(rt, genl_family_chain(i), family_list) {
- if (!rt->netnsok && !net_eq(net, &init_net))
- continue;
- if (++n < fams_to_skip)
- continue;
- if (ctrl_fill_info(rt, NETLINK_CB(cb->skb).portid,
- cb->nlh->nlmsg_seq, NLM_F_MULTI,
- skb, CTRL_CMD_NEWFAMILY) < 0)
- goto errout;
- }
- fams_to_skip = 0;
- }
- errout:
- cb->args[0] = i;
- cb->args[1] = n;
- return skb->len;
- }
- static struct sk_buff *ctrl_build_family_msg(struct genl_family *family,
- u32 portid, int seq, u8 cmd)
- {
- struct sk_buff *skb;
- int err;
- skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
- if (skb == NULL)
- return ERR_PTR(-ENOBUFS);
- err = ctrl_fill_info(family, portid, seq, 0, skb, cmd);
- if (err < 0) {
- nlmsg_free(skb);
- return ERR_PTR(err);
- }
- return skb;
- }
- 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;
- skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
- if (skb == NULL)
- return ERR_PTR(-ENOBUFS);
- err = ctrl_fill_mcgrp_info(family, grp, grp_id, portid,
- seq, 0, skb, cmd);
- if (err < 0) {
- nlmsg_free(skb);
- return ERR_PTR(err);
- }
- return skb;
- }
- static const struct nla_policy ctrl_policy[CTRL_ATTR_MAX+1] = {
- [CTRL_ATTR_FAMILY_ID] = { .type = NLA_U16 },
- [CTRL_ATTR_FAMILY_NAME] = { .type = NLA_NUL_STRING,
- .len = GENL_NAMSIZ - 1 },
- };
- static int ctrl_getfamily(struct sk_buff *skb, struct genl_info *info)
- {
- struct sk_buff *msg;
- struct genl_family *res = NULL;
- int err = -EINVAL;
- if (info->attrs[CTRL_ATTR_FAMILY_ID]) {
- u16 id = nla_get_u16(info->attrs[CTRL_ATTR_FAMILY_ID]);
- res = genl_family_find_byid(id);
- err = -ENOENT;
- }
- if (info->attrs[CTRL_ATTR_FAMILY_NAME]) {
- char *name;
- name = nla_data(info->attrs[CTRL_ATTR_FAMILY_NAME]);
- res = genl_family_find_byname(name);
- #ifdef CONFIG_MODULES
- if (res == NULL) {
- genl_unlock();
- up_read(&cb_lock);
- request_module("net-pf-%d-proto-%d-family-%s",
- PF_NETLINK, NETLINK_GENERIC, name);
- down_read(&cb_lock);
- genl_lock();
- res = genl_family_find_byname(name);
- }
- #endif
- err = -ENOENT;
- }
- if (res == NULL)
- return err;
- if (!res->netnsok && !net_eq(genl_info_net(info), &init_net)) {
- /* family doesn't exist here */
- return -ENOENT;
- }
- msg = ctrl_build_family_msg(res, info->snd_portid, info->snd_seq,
- CTRL_CMD_NEWFAMILY);
- if (IS_ERR(msg))
- return PTR_ERR(msg);
- return genlmsg_reply(msg, info);
- }
- static int genl_ctrl_event(int event, struct genl_family *family,
- const struct genl_multicast_group *grp,
- int grp_id)
- {
- struct sk_buff *msg;
- /* genl is still initialising */
- if (!init_net.genl_sock)
- return 0;
- switch (event) {
- case CTRL_CMD_NEWFAMILY:
- case CTRL_CMD_DELFAMILY:
- WARN_ON(grp);
- msg = ctrl_build_family_msg(family, 0, 0, event);
- break;
- case CTRL_CMD_NEWMCAST_GRP:
- case CTRL_CMD_DELMCAST_GRP:
- BUG_ON(!grp);
- msg = ctrl_build_mcgrp_msg(family, grp, grp_id, 0, 0, event);
- break;
- default:
- return -EINVAL;
- }
- if (IS_ERR(msg))
- return PTR_ERR(msg);
- if (!family->netnsok) {
- genlmsg_multicast_netns(&genl_ctrl, &init_net, msg, 0,
- 0, GFP_KERNEL);
- } else {
- rcu_read_lock();
- genlmsg_multicast_allns(&genl_ctrl, msg, 0,
- 0, GFP_ATOMIC);
- rcu_read_unlock();
- }
- return 0;
- }
- static struct genl_ops genl_ctrl_ops[] = {
- {
- .cmd = CTRL_CMD_GETFAMILY,
- .doit = ctrl_getfamily,
- .dumpit = ctrl_dumpfamily,
- .policy = ctrl_policy,
- },
- };
- static struct genl_multicast_group genl_ctrl_groups[] = {
- { .name = "notify", },
- };
- static int genl_bind(struct net *net, int group)
- {
- int i, err = -ENOENT;
- down_read(&cb_lock);
- for (i = 0; i < GENL_FAM_TAB_SIZE; i++) {
- struct genl_family *f;
- list_for_each_entry(f, genl_family_chain(i), family_list) {
- if (group >= f->mcgrp_offset &&
- group < f->mcgrp_offset + f->n_mcgrps) {
- int fam_grp = group - f->mcgrp_offset;
- if (!f->netnsok && net != &init_net)
- err = -ENOENT;
- else if (f->mcast_bind)
- err = f->mcast_bind(net, fam_grp);
- else
- err = 0;
- break;
- }
- }
- }
- up_read(&cb_lock);
- return err;
- }
- static void genl_unbind(struct net *net, int group)
- {
- int i;
- down_read(&cb_lock);
- for (i = 0; i < GENL_FAM_TAB_SIZE; i++) {
- struct genl_family *f;
- list_for_each_entry(f, genl_family_chain(i), family_list) {
- if (group >= f->mcgrp_offset &&
- group < f->mcgrp_offset + f->n_mcgrps) {
- int fam_grp = group - f->mcgrp_offset;
- if (f->mcast_unbind)
- f->mcast_unbind(net, fam_grp);
- break;
- }
- }
- }
- up_read(&cb_lock);
- }
- static int __net_init genl_pernet_init(struct net *net)
- {
- struct netlink_kernel_cfg cfg = {
- .input = genl_rcv,
- .flags = NL_CFG_F_NONROOT_RECV,
- .bind = genl_bind,
- .unbind = genl_unbind,
- };
- /* we'll bump the group number right afterwards */
- net->genl_sock = netlink_kernel_create(net, NETLINK_GENERIC, &cfg);
- if (!net->genl_sock && net_eq(net, &init_net))
- panic("GENL: Cannot initialize generic netlink\n");
- if (!net->genl_sock)
- return -ENOMEM;
- return 0;
- }
- static void __net_exit genl_pernet_exit(struct net *net)
- {
- netlink_kernel_release(net->genl_sock);
- net->genl_sock = NULL;
- }
- static struct pernet_operations genl_pernet_ops = {
- .init = genl_pernet_init,
- .exit = genl_pernet_exit,
- };
- static int __init genl_init(void)
- {
- int i, err;
- for (i = 0; i < GENL_FAM_TAB_SIZE; i++)
- INIT_LIST_HEAD(&family_ht[i]);
- err = genl_register_family_with_ops_groups(&genl_ctrl, genl_ctrl_ops,
- genl_ctrl_groups);
- if (err < 0)
- goto problem;
- err = register_pernet_subsys(&genl_pernet_ops);
- if (err)
- goto problem;
- return 0;
- problem:
- panic("GENL: Cannot register controller: %d\n", err);
- }
- subsys_initcall(genl_init);
- static int genlmsg_mcast(struct sk_buff *skb, u32 portid, unsigned long group,
- gfp_t flags)
- {
- struct sk_buff *tmp;
- struct net *net, *prev = NULL;
- bool delivered = false;
- int err;
- for_each_net_rcu(net) {
- if (prev) {
- tmp = skb_clone(skb, flags);
- if (!tmp) {
- err = -ENOMEM;
- goto error;
- }
- err = nlmsg_multicast(prev->genl_sock, tmp,
- portid, group, flags);
- if (!err)
- delivered = true;
- else if (err != -ESRCH)
- goto error;
- }
- prev = net;
- }
- err = nlmsg_multicast(prev->genl_sock, skb, portid, group, flags);
- if (!err)
- delivered = true;
- else if (err != -ESRCH)
- return err;
- return delivered ? 0 : -ESRCH;
- error:
- kfree_skb(skb);
- return err;
- }
- int genlmsg_multicast_allns(struct genl_family *family, struct sk_buff *skb,
- u32 portid, unsigned int group, gfp_t flags)
- {
- if (WARN_ON_ONCE(group >= family->n_mcgrps))
- return -EINVAL;
- group = family->mcgrp_offset + group;
- return genlmsg_mcast(skb, portid, group, flags);
- }
- EXPORT_SYMBOL(genlmsg_multicast_allns);
- void genl_notify(struct genl_family *family, struct sk_buff *skb,
- struct genl_info *info, u32 group, gfp_t flags)
- {
- struct net *net = genl_info_net(info);
- struct sock *sk = net->genl_sock;
- int report = 0;
- if (info->nlhdr)
- report = nlmsg_report(info->nlhdr);
- if (WARN_ON_ONCE(group >= family->n_mcgrps))
- return;
- group = family->mcgrp_offset + group;
- nlmsg_notify(sk, skb, info->snd_portid, group, report, flags);
- }
- EXPORT_SYMBOL(genl_notify);
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