diff options
Diffstat (limited to 'net/netlink/genetlink.c')
| -rw-r--r-- | net/netlink/genetlink.c | 994 |
1 files changed, 758 insertions, 236 deletions
diff --git a/net/netlink/genetlink.c b/net/netlink/genetlink.c index 4ae1538c54a..76393f2f4b2 100644 --- a/net/netlink/genetlink.c +++ b/net/netlink/genetlink.c @@ -3,47 +3,89 @@ * * Authors: Jamal Hadi Salim * Thomas Graf <tgraf@suug.ch> + * Johannes Berg <johannes@sipsolutions.net> */ -#include <linux/config.h> #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> -struct sock *genl_sock = NULL; +static DEFINE_MUTEX(genl_mutex); /* serialization of message processing */ +static DECLARE_RWSEM(cb_lock); -static DECLARE_MUTEX(genl_sem); /* serialization of message processing */ +void genl_lock(void) +{ + mutex_lock(&genl_mutex); +} +EXPORT_SYMBOL(genl_lock); -static void genl_lock(void) +void genl_unlock(void) { - down(&genl_sem); + mutex_unlock(&genl_mutex); } +EXPORT_SYMBOL(genl_unlock); -static int genl_trylock(void) +#ifdef CONFIG_LOCKDEP +int lockdep_genl_is_held(void) { - return down_trylock(&genl_sem); + return lockdep_is_held(&genl_mutex); } +EXPORT_SYMBOL(lockdep_genl_is_held); +#endif -static void genl_unlock(void) +static void genl_lock_all(void) { - up(&genl_sem); + down_write(&cb_lock); + genl_lock(); +} - if (genl_sock && genl_sock->sk_receive_queue.qlen) - genl_sock->sk_data_ready(genl_sock, 0); +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, void *data); +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) { @@ -79,13 +121,13 @@ static struct genl_family *genl_family_find_byname(char *name) return NULL; } -static struct genl_ops *genl_get_cmd(u8 cmd, struct genl_family *family) +static const struct genl_ops *genl_get_cmd(u8 cmd, struct genl_family *family) { - struct genl_ops *ops; + int i; - list_for_each_entry(ops, &family->ops_list, ops_list) - if (ops->cmd == cmd) - return ops; + for (i = 0; i < family->n_ops; i++) + if (family->ops[i].cmd == cmd) + return &family->ops[i]; return NULL; } @@ -93,102 +135,213 @@ static struct genl_ops *genl_get_cmd(u8 cmd, struct genl_family *family) /* Of course we are going to have problems once we hit * 2^16 alive types, but that can only happen by year 2K */ -static inline u16 genl_generate_id(void) +static u16 genl_generate_id(void) { - static u16 id_gen_idx; - int overflowed = 0; + static u16 id_gen_idx = GENL_MIN_ID; + int i; - do { - if (id_gen_idx == 0) + 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; + } - if (++id_gen_idx > GENL_MAX_ID) { - if (!overflowed) { - overflowed = 1; - id_gen_idx = 0; - continue; - } else - return 0; + 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; + } } - } while (genl_family_find_byid(id_gen_idx)); + 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); - return id_gen_idx; + for (i = id; i < id + n_groups; i++) + set_bit(i, mc_groups); + *first_id = id; + return 0; } -/** - * genl_register_ops - register generic netlink operations - * @family: generic netlink family - * @ops: operations to be registered - * - * Registers the specified operations and assigns them to the specified - * family. Either a doit or dumpit callback must be specified or the - * operation will fail. Only one operation structure per command - * identifier may be registered. - * - * See include/net/genetlink.h for more documenation on the operations - * structure. - * - * Returns 0 on success or a negative error code. - */ -int genl_register_ops(struct genl_family *family, struct genl_ops *ops) +static struct genl_family genl_ctrl; + +static int genl_validate_assign_mc_groups(struct genl_family *family) { - int err = -EINVAL; + int first_id; + int n_groups = family->n_mcgrps; + int err = 0, i; + bool groups_allocated = false; - if (ops->dumpit == NULL && ops->doit == NULL) - goto errout; + if (!n_groups) + return 0; - if (genl_get_cmd(ops->cmd, family)) { - err = -EEXIST; - goto errout; + 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; } - genl_lock(); - list_add_tail(&ops->ops_list, &family->ops_list); - genl_unlock(); + /* 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); + } - genl_ctrl_event(CTRL_CMD_NEWOPS, ops); - err = 0; -errout: return err; } -/** - * genl_unregister_ops - unregister generic netlink operations - * @family: generic netlink family - * @ops: operations to be unregistered - * - * Unregisters the specified operations and unassigns them from the - * specified family. The operation blocks until the current message - * processing has finished and doesn't start again until the - * unregister process has finished. - * - * Note: It is not necessary to unregister all operations before - * unregistering the family, unregistering the family will cause - * all assigned operations to be unregistered automatically. - * - * Returns 0 on success or a negative error code. - */ -int genl_unregister_ops(struct genl_family *family, struct genl_ops *ops) +static void genl_unregister_mc_groups(struct genl_family *family) { - struct genl_ops *rc; + struct net *net; + int i; - genl_lock(); - list_for_each_entry(rc, &family->ops_list, ops_list) { - if (rc == ops) { - list_del(&ops->ops_list); - genl_unlock(); - genl_ctrl_event(CTRL_CMD_DELOPS, ops); - return 0; - } + 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); } - genl_unlock(); + rcu_read_unlock(); + netlink_table_ungrab(); - return -ENOENT; + 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 + * __genl_register_family - register a generic netlink family * @family: generic netlink family * * Registers the specified family after validating it first. Only one @@ -196,11 +349,14 @@ int genl_unregister_ops(struct genl_family *family, struct genl_ops *ops) * 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 __genl_register_family(struct genl_family *family) { - int err = -EINVAL; + int err = -EINVAL, i; if (family->id && family->id < GENL_MIN_ID) goto errout; @@ -208,20 +364,17 @@ int genl_register_family(struct genl_family *family) if (family->id > GENL_MAX_ID) goto errout; - INIT_LIST_HEAD(&family->ops_list); + err = genl_validate_ops(family); + if (err) + return err; - genl_lock(); + genl_lock_all(); if (genl_family_find_byname(family->name)) { err = -EEXIST; goto errout_locked; } - if (genl_family_find_byid(family->id)) { - err = -EEXIST; - goto errout_locked; - } - if (family->id == GENL_ID_GENERATE) { u16 newid = genl_generate_id(); @@ -231,30 +384,42 @@ int genl_register_family(struct genl_family *family) } family->id = newid; + } else if (genl_family_find_byid(family->id)) { + err = -EEXIST; + goto errout_locked; } - if (family->maxattr) { + 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; + 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(); + genl_unlock_all(); - genl_ctrl_event(CTRL_CMD_NEWFAMILY, family); + /* 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(); + genl_unlock_all(); errout: return err; } +EXPORT_SYMBOL(__genl_register_family); /** * genl_unregister_family - unregister generic netlink family @@ -268,139 +433,374 @@ int genl_unregister_family(struct genl_family *family) { struct genl_family *rc; - genl_lock(); + genl_lock_all(); + + genl_unregister_mc_groups(family); list_for_each_entry(rc, genl_family_chain(family->id), family_list) { if (family->id != rc->id || strcmp(rc->name, family->name)) continue; list_del(&rc->family_list); - INIT_LIST_HEAD(&family->ops_list); - genl_unlock(); + family->n_ops = 0; + genl_unlock_all(); kfree(family->attrbuf); - genl_ctrl_event(CTRL_CMD_DELFAMILY, family); + genl_ctrl_event(CTRL_CMD_DELFAMILY, family, NULL, 0); return 0; } - genl_unlock(); + genl_unlock_all(); return -ENOENT; } +EXPORT_SYMBOL(genl_unregister_family); -static inline int genl_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, - int *errp) +/** + * 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) { - struct genl_ops *ops; - struct genl_family *family; - struct genl_info info; - struct genlmsghdr *hdr = nlmsg_data(nlh); - int hdrlen, err = -EINVAL; + 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; - if (!(nlh->nlmsg_flags & NLM_F_REQUEST)) - goto ignore; + nlh = nlmsg_put(skb, portid, seq, family->id, GENL_HDRLEN + + family->hdrsize, flags); + if (nlh == NULL) + return NULL; - if (nlh->nlmsg_type < NLMSG_MIN_TYPE) - goto ignore; + hdr = nlmsg_data(nlh); + hdr->cmd = cmd; + hdr->version = family->version; + hdr->reserved = 0; - family = genl_family_find_byid(nlh->nlmsg_type); - if (family == NULL) { - err = -ENOENT; - goto errout; + return (char *) hdr + GENL_HDRLEN; +} +EXPORT_SYMBOL(genlmsg_put); + +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)) - goto errout; + return -EINVAL; ops = genl_get_cmd(hdr->cmd, family); - if (ops == NULL) { - err = -EOPNOTSUPP; - goto errout; - } + if (ops == NULL) + return -EOPNOTSUPP; - if ((ops->flags & GENL_ADMIN_PERM) && security_netlink_recv(skb)) { - err = -EPERM; - goto errout; - } + 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, + .dump = genl_lock_dumpit, + .done = genl_lock_done, + }; + + genl_unlock(); + rc = __netlink_dump_start(net->genl_sock, skb, nlh, &c); + genl_lock(); - if (nlh->nlmsg_flags & NLM_F_DUMP) { - if (ops->dumpit == NULL) { - err = -EOPNOTSUPP; - goto errout; + } else { + struct netlink_dump_control c = { + .module = family->module, + .dump = ops->dumpit, + .done = ops->done, + }; + + rc = __netlink_dump_start(net->genl_sock, skb, nlh, &c); } - *errp = err = netlink_dump_start(genl_sock, skb, nlh, - ops->dumpit, NULL); - if (err == 0) - skb_pull(skb, min(NLMSG_ALIGN(nlh->nlmsg_len), - skb->len)); - return -1; + return rc; } - if (ops->doit == NULL) { - err = -EOPNOTSUPP; - goto errout; - } + if (ops->doit == NULL) + return -EOPNOTSUPP; - if (family->attrbuf) { - err = nlmsg_parse(nlh, hdrlen, family->attrbuf, family->maxattr, + 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 errout; + goto out; } info.snd_seq = nlh->nlmsg_seq; - info.snd_pid = NETLINK_CB(skb).pid; + info.snd_portid = NETLINK_CB(skb).portid; info.nlhdr = nlh; info.genlhdr = nlmsg_data(nlh); info.userhdr = nlmsg_data(nlh) + GENL_HDRLEN; - info.attrs = family->attrbuf; + 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; + } - *errp = err = ops->doit(skb, &info); - return err; + err = ops->doit(skb, &info); -ignore: - return 0; + if (family->post_doit) + family->post_doit(ops, skb, &info); -errout: - *errp = err; - return -1; +out: + if (family->parallel_ops) + kfree(attrbuf); + + return err; } -static void genl_rcv(struct sock *sk, int len) +static int genl_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh) { - unsigned int qlen = 0; + struct genl_family *family; + int err; - do { - if (genl_trylock()) - return; - netlink_run_queue(sk, &qlen, &genl_rcv_msg); + 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(); - } while (qlen && genl_sock && genl_sock->sk_receive_queue.qlen); + + 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 int ctrl_fill_info(struct genl_family *family, u32 pid, u32 seq, +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, pid, seq, GENL_ID_CTRL, 0, flags, cmd, - family->version); + 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); + } + + return genlmsg_end(skb, hdr); + +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; - NLA_PUT_STRING(skb, CTRL_ATTR_FAMILY_NAME, family->name); - NLA_PUT_U16(skb, CTRL_ATTR_FAMILY_ID, family->id); + 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); return genlmsg_end(skb, hdr); nla_put_failure: - return genlmsg_cancel(skb, hdr); + genlmsg_cancel(skb, hdr); + return -EMSGSIZE; } static int ctrl_dumpfamily(struct sk_buff *skb, struct netlink_callback *cb) @@ -408,17 +808,18 @@ 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 = 0; i < GENL_FAM_TAB_SIZE; i++) { - if (i < chains_to_skip) - continue; + 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).pid, + if (ctrl_fill_info(rt, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq, NLM_F_MULTI, skb, CTRL_CMD_NEWFAMILY) < 0) goto errout; @@ -434,17 +835,39 @@ errout: return skb->len; } -static struct sk_buff *ctrl_build_msg(struct genl_family *family, u32 pid, - int seq, u8 cmd) +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_GOODSIZE); + skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); if (skb == NULL) return ERR_PTR(-ENOBUFS); - err = ctrl_fill_info(family, pid, 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); @@ -453,9 +876,10 @@ static struct sk_buff *ctrl_build_msg(struct genl_family *family, u32 pid, return skb; } -static struct nla_policy ctrl_policy[CTRL_ATTR_MAX+1] __read_mostly = { +static const struct nla_policy ctrl_policy[CTRL_ATTR_MAX+1] = { [CTRL_ATTR_FAMILY_ID] = { .type = NLA_U16 }, - [CTRL_ATTR_FAMILY_NAME] = { .type = NLA_STRING }, + [CTRL_ATTR_FAMILY_NAME] = { .type = NLA_NUL_STRING, + .len = GENL_NAMSIZ - 1 }, }; static int ctrl_getfamily(struct sk_buff *skb, struct genl_info *info) @@ -467,68 +891,126 @@ static int ctrl_getfamily(struct sk_buff *skb, struct genl_info *info) 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[GENL_NAMSIZ]; - - if (nla_strlcpy(name, info->attrs[CTRL_ATTR_FAMILY_NAME], - GENL_NAMSIZ) >= GENL_NAMSIZ) - goto errout; + char *name; + name = nla_data(info->attrs[CTRL_ATTR_FAMILY_NAME]); res = genl_family_find_byname(name); - } - - if (res == NULL) { +#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; - goto errout; } - msg = ctrl_build_msg(res, info->snd_pid, info->snd_seq, - CTRL_CMD_NEWFAMILY); - if (IS_ERR(msg)) { - err = PTR_ERR(msg); - goto errout; + if (res == NULL) + return err; + + if (!res->netnsok && !net_eq(genl_info_net(info), &init_net)) { + /* family doesn't exist here */ + return -ENOENT; } - err = genlmsg_unicast(msg, info->snd_pid); -errout: - return err; + 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, void *data) +static int genl_ctrl_event(int event, struct genl_family *family, + const struct genl_multicast_group *grp, + int grp_id) { struct sk_buff *msg; - if (genl_sock == NULL) + /* genl is still initialising */ + if (!init_net.genl_sock) return 0; switch (event) { case CTRL_CMD_NEWFAMILY: case CTRL_CMD_DELFAMILY: - msg = ctrl_build_msg(data, 0, 0, event); - if (IS_ERR(msg)) - return PTR_ERR(msg); - - genlmsg_multicast(msg, 0, GENL_ID_CTRL); + 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_ops genl_ctrl_ops[] = { + { + .cmd = CTRL_CMD_GETFAMILY, + .doit = ctrl_getfamily, + .dumpit = ctrl_dumpfamily, + .policy = ctrl_policy, + }, }; -static struct genl_family genl_ctrl = { - .id = GENL_ID_CTRL, - .name = "nlctrl", - .version = 0x1, - .maxattr = CTRL_ATTR_MAX, +static struct genl_multicast_group genl_ctrl_groups[] = { + { .name = "notify", }, +}; + +static int __net_init genl_pernet_init(struct net *net) +{ + struct netlink_kernel_cfg cfg = { + .input = genl_rcv, + .flags = NL_CFG_F_NONROOT_RECV, + }; + + /* 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) @@ -538,35 +1020,75 @@ 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(&genl_ctrl); + err = genl_register_family_with_ops_groups(&genl_ctrl, genl_ctrl_ops, + genl_ctrl_groups); if (err < 0) - goto errout; + goto problem; - err = genl_register_ops(&genl_ctrl, &genl_ctrl_ops); - if (err < 0) - goto errout_register; - - netlink_set_nonroot(NETLINK_GENERIC, NL_NONROOT_RECV); - genl_sock = netlink_kernel_create(NETLINK_GENERIC, GENL_MAX_ID, - genl_rcv, THIS_MODULE); - if (genl_sock == NULL) { - panic("GENL: Cannot initialize generic netlink\n"); - return -ENOMEM; - } + err = register_pernet_subsys(&genl_pernet_ops); + if (err) + goto problem; return 0; -errout_register: - genl_unregister_family(&genl_ctrl); -errout: +problem: panic("GENL: Cannot register controller: %d\n", err); - return err; } subsys_initcall(genl_init); -EXPORT_SYMBOL(genl_sock); -EXPORT_SYMBOL(genl_register_ops); -EXPORT_SYMBOL(genl_unregister_ops); -EXPORT_SYMBOL(genl_register_family); -EXPORT_SYMBOL(genl_unregister_family); +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; + 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) + goto error; + } + + prev = net; + } + + return nlmsg_multicast(prev->genl_sock, skb, portid, group, flags); + 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 net *net, u32 portid, u32 group, + struct nlmsghdr *nlh, gfp_t flags) +{ + struct sock *sk = net->genl_sock; + int report = 0; + + if (nlh) + report = nlmsg_report(nlh); + + if (WARN_ON_ONCE(group >= family->n_mcgrps)) + return; + group = family->mcgrp_offset + group; + nlmsg_notify(sk, skb, portid, group, report, flags); +} +EXPORT_SYMBOL(genl_notify); |