// SPDX-License-Identifier: GPL-2.0 /* * NETLINK Generic Netlink Family * * Authors: Jamal Hadi Salim * Thomas Graf * Johannes Berg */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include 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); static void genl_lock_all(void) { down_write(&cb_lock); genl_lock(); } static void genl_unlock_all(void) { genl_unlock(); up_write(&cb_lock); } static void genl_op_lock(const struct genl_family *family) { if (!family->parallel_ops) genl_lock(); } static void genl_op_unlock(const struct genl_family *family) { if (!family->parallel_ops) genl_unlock(); } static DEFINE_IDR(genl_fam_idr); /* * 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; /* We need the last attribute with non-zero ID therefore a 2-entry array */ static struct nla_policy genl_policy_reject_all[] = { { .type = NLA_REJECT }, { .type = NLA_REJECT }, }; static int genl_ctrl_event(int event, const struct genl_family *family, const struct genl_multicast_group *grp, int grp_id); static void genl_op_fill_in_reject_policy(const struct genl_family *family, struct genl_ops *op) { BUILD_BUG_ON(ARRAY_SIZE(genl_policy_reject_all) - 1 != 1); if (op->policy || op->cmd < family->resv_start_op) return; op->policy = genl_policy_reject_all; op->maxattr = 1; } static void genl_op_fill_in_reject_policy_split(const struct genl_family *family, struct genl_split_ops *op) { if (op->policy) return; op->policy = genl_policy_reject_all; op->maxattr = 1; } static const struct genl_family *genl_family_find_byid(unsigned int id) { return idr_find(&genl_fam_idr, id); } static const struct genl_family *genl_family_find_byname(char *name) { const struct genl_family *family; unsigned int id; idr_for_each_entry(&genl_fam_idr, family, id) if (strcmp(family->name, name) == 0) return family; return NULL; } struct genl_op_iter { const struct genl_family *family; struct genl_split_ops doit; struct genl_split_ops dumpit; int cmd_idx; int entry_idx; u32 cmd; u8 flags; }; static void genl_op_from_full(const struct genl_family *family, unsigned int i, struct genl_ops *op) { *op = family->ops[i]; if (!op->maxattr) op->maxattr = family->maxattr; if (!op->policy) op->policy = family->policy; genl_op_fill_in_reject_policy(family, op); } static int genl_get_cmd_full(u32 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) { genl_op_from_full(family, i, op); return 0; } 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; op->maxattr = family->maxattr; op->policy = family->policy; genl_op_fill_in_reject_policy(family, op); } static int genl_get_cmd_small(u32 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 void genl_op_from_split(struct genl_op_iter *iter) { const struct genl_family *family = iter->family; int i, cnt = 0; i = iter->entry_idx - family->n_ops - family->n_small_ops; if (family->split_ops[i + cnt].flags & GENL_CMD_CAP_DO) { iter->doit = family->split_ops[i + cnt]; genl_op_fill_in_reject_policy_split(family, &iter->doit); cnt++; } else { memset(&iter->doit, 0, sizeof(iter->doit)); } if (i + cnt < family->n_split_ops && family->split_ops[i + cnt].flags & GENL_CMD_CAP_DUMP && (!cnt || family->split_ops[i + cnt].cmd == iter->doit.cmd)) { iter->dumpit = family->split_ops[i + cnt]; genl_op_fill_in_reject_policy_split(family, &iter->dumpit); cnt++; } else { memset(&iter->dumpit, 0, sizeof(iter->dumpit)); } WARN_ON(!cnt); iter->entry_idx += cnt; } static int genl_get_cmd_split(u32 cmd, u8 flag, const struct genl_family *family, struct genl_split_ops *op) { int i; for (i = 0; i < family->n_split_ops; i++) if (family->split_ops[i].cmd == cmd && family->split_ops[i].flags & flag) { *op = family->split_ops[i]; return 0; } return -ENOENT; } static int genl_cmd_full_to_split(struct genl_split_ops *op, const struct genl_family *family, const struct genl_ops *full, u8 flags) { if ((flags & GENL_CMD_CAP_DO && !full->doit) || (flags & GENL_CMD_CAP_DUMP && !full->dumpit)) { memset(op, 0, sizeof(*op)); return -ENOENT; } if (flags & GENL_CMD_CAP_DUMP) { op->start = full->start; op->dumpit = full->dumpit; op->done = full->done; } else { op->pre_doit = family->pre_doit; op->doit = full->doit; op->post_doit = family->post_doit; } if (flags & GENL_CMD_CAP_DUMP && full->validate & GENL_DONT_VALIDATE_DUMP) { op->policy = NULL; op->maxattr = 0; } else { op->policy = full->policy; op->maxattr = full->maxattr; } op->cmd = full->cmd; op->internal_flags = full->internal_flags; op->flags = full->flags; op->validate = full->validate; /* Make sure flags include the GENL_CMD_CAP_DO / GENL_CMD_CAP_DUMP */ op->flags |= flags; return 0; } /* Must make sure that op is initialized to 0 on failure */ static int genl_get_cmd(u32 cmd, u8 flags, const struct genl_family *family, struct genl_split_ops *op) { struct genl_ops full; int err; err = genl_get_cmd_full(cmd, family, &full); if (err == -ENOENT) err = genl_get_cmd_small(cmd, family, &full); /* Found one of legacy forms */ if (err == 0) return genl_cmd_full_to_split(op, family, &full, flags); err = genl_get_cmd_split(cmd, flags, family, op); if (err) memset(op, 0, sizeof(*op)); return err; } /* For policy dumping only, get ops of both do and dump. * Fail if both are missing, genl_get_cmd() will zero-init in case of failure. */ static int genl_get_cmd_both(u32 cmd, const struct genl_family *family, struct genl_split_ops *doit, struct genl_split_ops *dumpit) { int err1, err2; err1 = genl_get_cmd(cmd, GENL_CMD_CAP_DO, family, doit); err2 = genl_get_cmd(cmd, GENL_CMD_CAP_DUMP, family, dumpit); return err1 && err2 ? -ENOENT : 0; } static bool genl_op_iter_init(const struct genl_family *family, struct genl_op_iter *iter) { iter->family = family; iter->cmd_idx = 0; iter->entry_idx = 0; iter->flags = 0; return iter->family->n_ops + iter->family->n_small_ops + iter->family->n_split_ops; } static bool genl_op_iter_next(struct genl_op_iter *iter) { const struct genl_family *family = iter->family; bool legacy_op = true; struct genl_ops op; if (iter->entry_idx < family->n_ops) { genl_op_from_full(family, iter->entry_idx, &op); } else if (iter->entry_idx < family->n_ops + family->n_small_ops) { genl_op_from_small(family, iter->entry_idx - family->n_ops, &op); } else if (iter->entry_idx < family->n_ops + family->n_small_ops + family->n_split_ops) { legacy_op = false; /* updates entry_idx */ genl_op_from_split(iter); } else { return false; } iter->cmd_idx++; if (legacy_op) { iter->entry_idx++; genl_cmd_full_to_split(&iter->doit, family, &op, GENL_CMD_CAP_DO); genl_cmd_full_to_split(&iter->dumpit, family, &op, GENL_CMD_CAP_DUMP); } iter->cmd = iter->doit.cmd | iter->dumpit.cmd; iter->flags = iter->doit.flags | iter->dumpit.flags; return true; } static void genl_op_iter_copy(struct genl_op_iter *dst, struct genl_op_iter *src) { *dst = *src; } static unsigned int genl_op_iter_idx(struct genl_op_iter *iter) { return iter->cmd_idx; } 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 + n_groups > 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(!string_is_terminated(grp->name, GENL_NAMSIZ))) 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 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(const 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 bool genl_split_op_check(const struct genl_split_ops *op) { if (WARN_ON(hweight8(op->flags & (GENL_CMD_CAP_DO | GENL_CMD_CAP_DUMP)) != 1)) return true; return false; } static int genl_validate_ops(const struct genl_family *family) { struct genl_op_iter i, j; unsigned int s; if (WARN_ON(family->n_ops && !family->ops) || WARN_ON(family->n_small_ops && !family->small_ops) || WARN_ON(family->n_split_ops && !family->split_ops)) return -EINVAL; for (genl_op_iter_init(family, &i); genl_op_iter_next(&i); ) { if (!(i.flags & (GENL_CMD_CAP_DO | GENL_CMD_CAP_DUMP))) return -EINVAL; if (WARN_ON(i.cmd >= family->resv_start_op && (i.doit.validate || i.dumpit.validate))) return -EINVAL; genl_op_iter_copy(&j, &i); while (genl_op_iter_next(&j)) { if (i.cmd == j.cmd) return -EINVAL; } } if (family->n_split_ops) { if (genl_split_op_check(&family->split_ops[0])) return -EINVAL; } for (s = 1; s < family->n_split_ops; s++) { const struct genl_split_ops *a, *b; a = &family->split_ops[s - 1]; b = &family->split_ops[s]; if (genl_split_op_check(b)) return -EINVAL; /* Check sort order */ if (a->cmd < b->cmd) { continue; } else if (a->cmd > b->cmd) { WARN_ON(1); return -EINVAL; } if (a->internal_flags != b->internal_flags || ((a->flags ^ b->flags) & ~(GENL_CMD_CAP_DO | GENL_CMD_CAP_DUMP))) { WARN_ON(1); return -EINVAL; } if ((a->flags & GENL_CMD_CAP_DO) && (b->flags & GENL_CMD_CAP_DUMP)) continue; WARN_ON(1); return -EINVAL; } return 0; } static void *genl_sk_priv_alloc(struct genl_family *family) { void *priv; priv = kzalloc(family->sock_priv_size, GFP_KERNEL); if (!priv) return ERR_PTR(-ENOMEM); if (family->sock_priv_init) family->sock_priv_init(priv); return priv; } static void genl_sk_priv_free(const struct genl_family *family, void *priv) { if (family->sock_priv_destroy) family->sock_priv_destroy(priv); kfree(priv); } static int genl_sk_privs_alloc(struct genl_family *family) { if (!family->sock_priv_size) return 0; family->sock_privs = kzalloc(sizeof(*family->sock_privs), GFP_KERNEL); if (!family->sock_privs) return -ENOMEM; xa_init(family->sock_privs); return 0; } static void genl_sk_privs_free(const struct genl_family *family) { unsigned long id; void *priv; if (!family->sock_priv_size) return; xa_for_each(family->sock_privs, id, priv) genl_sk_priv_free(family, priv); xa_destroy(family->sock_privs); kfree(family->sock_privs); } static void genl_sk_priv_free_by_sock(struct genl_family *family, struct sock *sk) { void *priv; if (!family->sock_priv_size) return; priv = xa_erase(family->sock_privs, (unsigned long) sk); if (!priv) return; genl_sk_priv_free(family, priv); } static void genl_release(struct sock *sk, unsigned long *groups) { struct genl_family *family; unsigned int id; down_read(&cb_lock); idr_for_each_entry(&genl_fam_idr, family, id) genl_sk_priv_free_by_sock(family, sk); up_read(&cb_lock); } /** * __genl_sk_priv_get - Get family private pointer for socket, if exists * * @family: family * @sk: socket * * Lookup a private memory for a Generic netlink family and specified socket. * * Caller should make sure this is called in RCU read locked section. * * Return: valid pointer on success, otherwise negative error value * encoded by ERR_PTR(), NULL in case priv does not exist. */ void *__genl_sk_priv_get(struct genl_family *family, struct sock *sk) { if (WARN_ON_ONCE(!family->sock_privs)) return ERR_PTR(-EINVAL); return xa_load(family->sock_privs, (unsigned long) sk); } /** * genl_sk_priv_get - Get family private pointer for socket * * @family: family * @sk: socket * * Lookup a private memory for a Generic netlink family and specified socket. * Allocate the private memory in case it was not already done. * * Return: valid pointer on success, otherwise negative error value * encoded by ERR_PTR(). */ void *genl_sk_priv_get(struct genl_family *family, struct sock *sk) { void *priv, *old_priv; priv = __genl_sk_priv_get(family, sk); if (priv) return priv; /* priv for the family does not exist so far, create it. */ priv = genl_sk_priv_alloc(family); if (IS_ERR(priv)) return ERR_CAST(priv); old_priv = xa_cmpxchg(family->sock_privs, (unsigned long) sk, NULL, priv, GFP_KERNEL); if (old_priv) { genl_sk_priv_free(family, priv); if (xa_is_err(old_priv)) return ERR_PTR(xa_err(old_priv)); /* Race happened, priv for the socket was already inserted. */ return old_priv; } return priv; } /** * 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's ops, multicast groups and module pointer must already * be assigned. * * Return 0 on success or a negative error code. */ int genl_register_family(struct genl_family *family) { int err, i; int start = GENL_START_ALLOC, end = GENL_MAX_ID; err = genl_validate_ops(family); if (err) return err; genl_lock_all(); if (genl_family_find_byname(family->name)) { err = -EEXIST; goto errout_locked; } err = genl_sk_privs_alloc(family); if (err) goto errout_locked; /* * Sadly, a few cases need to be special-cased * due to them having previously abused the API * and having used their family ID also as their * multicast group ID, so we use reserved IDs * for both to be sure we can do that mapping. */ if (family == &genl_ctrl) { /* and this needs to be special for initial family lookups */ start = end = GENL_ID_CTRL; } else if (strcmp(family->name, "pmcraid") == 0) { start = end = GENL_ID_PMCRAID; } else if (strcmp(family->name, "VFS_DQUOT") == 0) { start = end = GENL_ID_VFS_DQUOT; } family->id = idr_alloc_cyclic(&genl_fam_idr, family, start, end + 1, GFP_KERNEL); if (family->id < 0) { err = family->id; goto errout_sk_privs_free; } err = genl_validate_assign_mc_groups(family); if (err) goto errout_remove; 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_remove: idr_remove(&genl_fam_idr, family->id); errout_sk_privs_free: genl_sk_privs_free(family); errout_locked: genl_unlock_all(); 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(const struct genl_family *family) { genl_lock_all(); if (!genl_family_find_byid(family->id)) { genl_unlock_all(); return -ENOENT; } genl_unregister_mc_groups(family); idr_remove(&genl_fam_idr, family->id); up_write(&cb_lock); wait_event(genl_sk_destructing_waitq, atomic_read(&genl_sk_destructing_cnt) == 0); genl_sk_privs_free(family); genl_unlock(); genl_ctrl_event(CTRL_CMD_DELFAMILY, family, NULL, 0); return 0; } EXPORT_SYMBOL(genl_unregister_family); /** * 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, const 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 struct genl_dumpit_info *genl_dumpit_info_alloc(void) { return kmalloc(sizeof(struct genl_dumpit_info), GFP_KERNEL); } static void genl_dumpit_info_free(const struct genl_dumpit_info *info) { kfree(info); } static struct nlattr ** genl_family_rcv_msg_attrs_parse(const struct genl_family *family, struct nlmsghdr *nlh, struct netlink_ext_ack *extack, const struct genl_split_ops *ops, int hdrlen, enum genl_validate_flags no_strict_flag) { enum netlink_validation validate = ops->validate & no_strict_flag ? NL_VALIDATE_LIBERAL : NL_VALIDATE_STRICT; struct nlattr **attrbuf; int err; if (!ops->maxattr) return NULL; attrbuf = kmalloc_array(ops->maxattr + 1, sizeof(struct nlattr *), GFP_KERNEL); if (!attrbuf) return ERR_PTR(-ENOMEM); err = __nlmsg_parse(nlh, hdrlen, attrbuf, ops->maxattr, ops->policy, validate, extack); if (err) { kfree(attrbuf); return ERR_PTR(err); } return attrbuf; } static void genl_family_rcv_msg_attrs_free(struct nlattr **attrbuf) { kfree(attrbuf); } struct genl_start_context { const struct genl_family *family; struct nlmsghdr *nlh; struct netlink_ext_ack *extack; const struct genl_split_ops *ops; int hdrlen; }; static int genl_start(struct netlink_callback *cb) { struct genl_start_context *ctx = cb->data; const struct genl_split_ops *ops; struct genl_dumpit_info *info; struct nlattr **attrs = NULL; int rc = 0; ops = ctx->ops; if (!(ops->validate & GENL_DONT_VALIDATE_DUMP) && ctx->nlh->nlmsg_len < nlmsg_msg_size(ctx->hdrlen)) return -EINVAL; attrs = genl_family_rcv_msg_attrs_parse(ctx->family, ctx->nlh, ctx->extack, ops, ctx->hdrlen, GENL_DONT_VALIDATE_DUMP_STRICT); if (IS_ERR(attrs)) return PTR_ERR(attrs); info = genl_dumpit_info_alloc(); if (!info) { genl_family_rcv_msg_attrs_free(attrs); return -ENOMEM; } info->op = *ops; info->info.family = ctx->family; info->info.snd_seq = cb->nlh->nlmsg_seq; info->info.snd_portid = NETLINK_CB(cb->skb).portid; info->info.nlhdr = cb->nlh; info->info.genlhdr = nlmsg_data(cb->nlh); info->info.attrs = attrs; genl_info_net_set(&info->info, sock_net(cb->skb->sk)); info->info.extack = cb->extack; memset(&info->info.user_ptr, 0, sizeof(info->info.user_ptr)); cb->data = info; if (ops->start) { genl_op_lock(ctx->family); rc = ops->start(cb); genl_op_unlock(ctx->family); } if (rc) { genl_family_rcv_msg_attrs_free(info->info.attrs); genl_dumpit_info_free(info); cb->data = NULL; } return rc; } static int genl_dumpit(struct sk_buff *skb, struct netlink_callback *cb) { struct genl_dumpit_info *dump_info = cb->data; const struct genl_split_ops *ops = &dump_info->op; struct genl_info *info = &dump_info->info; int rc; info->extack = cb->extack; genl_op_lock(info->family); rc = ops->dumpit(skb, cb); genl_op_unlock(info->family); return rc; } static int genl_done(struct netlink_callback *cb) { struct genl_dumpit_info *dump_info = cb->data; const struct genl_split_ops *ops = &dump_info->op; struct genl_info *info = &dump_info->info; int rc = 0; info->extack = cb->extack; if (ops->done) { genl_op_lock(info->family); rc = ops->done(cb); genl_op_unlock(info->family); } genl_family_rcv_msg_attrs_free(info->attrs); genl_dumpit_info_free(dump_info); return rc; } static int genl_family_rcv_msg_dumpit(const struct genl_family *family, struct sk_buff *skb, struct nlmsghdr *nlh, struct netlink_ext_ack *extack, const struct genl_split_ops *ops, int hdrlen, struct net *net) { struct genl_start_context ctx; struct netlink_dump_control c = { .module = family->module, .data = &ctx, .start = genl_start, .dump = genl_dumpit, .done = genl_done, .extack = extack, }; int err; ctx.family = family; ctx.nlh = nlh; ctx.extack = extack; ctx.ops = ops; ctx.hdrlen = hdrlen; genl_op_unlock(family); err = __netlink_dump_start(net->genl_sock, skb, nlh, &c); genl_op_lock(family); return err; } static int genl_family_rcv_msg_doit(const struct genl_family *family, struct sk_buff *skb, struct nlmsghdr *nlh, struct netlink_ext_ack *extack, const struct genl_split_ops *ops, int hdrlen, struct net *net) { struct nlattr **attrbuf; struct genl_info info; int err; attrbuf = genl_family_rcv_msg_attrs_parse(family, nlh, extack, ops, hdrlen, GENL_DONT_VALIDATE_STRICT); if (IS_ERR(attrbuf)) return PTR_ERR(attrbuf); info.snd_seq = nlh->nlmsg_seq; info.snd_portid = NETLINK_CB(skb).portid; info.family = family; info.nlhdr = nlh; info.genlhdr = nlmsg_data(nlh); info.attrs = attrbuf; info.extack = extack; genl_info_net_set(&info, net); memset(&info.user_ptr, 0, sizeof(info.user_ptr)); if (ops->pre_doit) { err = ops->pre_doit(ops, skb, &info); if (err) goto out; } err = ops->doit(skb, &info); if (ops->post_doit) ops->post_doit(ops, skb, &info); out: genl_family_rcv_msg_attrs_free(attrbuf); return err; } static int genl_header_check(const struct genl_family *family, struct nlmsghdr *nlh, struct genlmsghdr *hdr, struct netlink_ext_ack *extack) { u16 flags; /* Only for commands added after we started validating */ if (hdr->cmd < family->resv_start_op) return 0; if (hdr->reserved) { NL_SET_ERR_MSG(extack, "genlmsghdr.reserved field is not 0"); return -EINVAL; } /* Old netlink flags have pretty loose semantics, allow only the flags * consumed by the core where we can enforce the meaning. */ flags = nlh->nlmsg_flags; if ((flags & NLM_F_DUMP) == NLM_F_DUMP) /* DUMP is 2 bits */ flags &= ~NLM_F_DUMP; if (flags & ~(NLM_F_REQUEST | NLM_F_ACK | NLM_F_ECHO)) { NL_SET_ERR_MSG(extack, "ambiguous or reserved bits set in nlmsg_flags"); return -EINVAL; } return 0; } static int genl_family_rcv_msg(const struct genl_family *family, struct sk_buff *skb, struct nlmsghdr *nlh, struct netlink_ext_ack *extack) { struct net *net = sock_net(skb->sk); struct genlmsghdr *hdr = nlmsg_data(nlh); struct genl_split_ops op; int hdrlen; u8 flags; /* 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; if (genl_header_check(family, nlh, hdr, extack)) return -EINVAL; flags = (nlh->nlmsg_flags & NLM_F_DUMP) == NLM_F_DUMP ? GENL_CMD_CAP_DUMP : GENL_CMD_CAP_DO; if (genl_get_cmd(hdr->cmd, flags, family, &op)) return -EOPNOTSUPP; if ((op.flags & GENL_ADMIN_PERM) && !netlink_capable(skb, CAP_NET_ADMIN)) return -EPERM; if ((op.flags & GENL_UNS_ADMIN_PERM) && !netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN)) return -EPERM; if (flags & GENL_CMD_CAP_DUMP) return genl_family_rcv_msg_dumpit(family, skb, nlh, extack, &op, hdrlen, net); else return genl_family_rcv_msg_doit(family, skb, nlh, extack, &op, hdrlen, net); } static int genl_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, struct netlink_ext_ack *extack) { const struct genl_family *family; int err; family = genl_family_find_byid(nlh->nlmsg_type); if (family == NULL) return -ENOENT; genl_op_lock(family); err = genl_family_rcv_msg(family, skb, nlh, extack); genl_op_unlock(family); 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; static int ctrl_fill_info(const struct genl_family *family, u32 portid, u32 seq, u32 flags, struct sk_buff *skb, u8 cmd) { struct genl_op_iter i; 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 (genl_op_iter_init(family, &i)) { struct nlattr *nla_ops; nla_ops = nla_nest_start_noflag(skb, CTRL_ATTR_OPS); if (nla_ops == NULL) goto nla_put_failure; while (genl_op_iter_next(&i)) { struct nlattr *nest; u32 op_flags; op_flags = i.flags; if (i.doit.policy || i.dumpit.policy) op_flags |= GENL_CMD_CAP_HASPOL; nest = nla_nest_start_noflag(skb, genl_op_iter_idx(&i)); if (nest == NULL) goto nla_put_failure; if (nla_put_u32(skb, CTRL_ATTR_OP_ID, i.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_noflag(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_noflag(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(const 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_noflag(skb, CTRL_ATTR_MCAST_GROUPS); if (nla_grps == NULL) goto nla_put_failure; nest = nla_nest_start_noflag(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 n = 0; struct genl_family *rt; struct net *net = sock_net(skb->sk); int fams_to_skip = cb->args[0]; unsigned int id; idr_for_each_entry(&genl_fam_idr, rt, id) { 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) { n--; break; } } cb->args[0] = n; return skb->len; } static struct sk_buff *ctrl_build_family_msg(const 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(const 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_family[] = { [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; const 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, const 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; } struct ctrl_dump_policy_ctx { struct netlink_policy_dump_state *state; const struct genl_family *rt; struct genl_op_iter *op_iter; u32 op; u16 fam_id; u8 dump_map:1, single_op:1; }; static const struct nla_policy ctrl_policy_policy[] = { [CTRL_ATTR_FAMILY_ID] = { .type = NLA_U16 }, [CTRL_ATTR_FAMILY_NAME] = { .type = NLA_NUL_STRING, .len = GENL_NAMSIZ - 1 }, [CTRL_ATTR_OP] = { .type = NLA_U32 }, }; static int ctrl_dumppolicy_start(struct netlink_callback *cb) { const struct genl_dumpit_info *info = genl_dumpit_info(cb); struct ctrl_dump_policy_ctx *ctx = (void *)cb->ctx; struct nlattr **tb = info->info.attrs; const struct genl_family *rt; struct genl_op_iter i; int err; BUILD_BUG_ON(sizeof(*ctx) > sizeof(cb->ctx)); if (!tb[CTRL_ATTR_FAMILY_ID] && !tb[CTRL_ATTR_FAMILY_NAME]) return -EINVAL; if (tb[CTRL_ATTR_FAMILY_ID]) { ctx->fam_id = nla_get_u16(tb[CTRL_ATTR_FAMILY_ID]); } else { rt = genl_family_find_byname( nla_data(tb[CTRL_ATTR_FAMILY_NAME])); if (!rt) return -ENOENT; ctx->fam_id = rt->id; } rt = genl_family_find_byid(ctx->fam_id); if (!rt) return -ENOENT; ctx->rt = rt; if (tb[CTRL_ATTR_OP]) { struct genl_split_ops doit, dump; ctx->single_op = true; ctx->op = nla_get_u32(tb[CTRL_ATTR_OP]); err = genl_get_cmd_both(ctx->op, rt, &doit, &dump); if (err) { NL_SET_BAD_ATTR(cb->extack, tb[CTRL_ATTR_OP]); return err; } if (doit.policy) { err = netlink_policy_dump_add_policy(&ctx->state, doit.policy, doit.maxattr); if (err) goto err_free_state; } if (dump.policy) { err = netlink_policy_dump_add_policy(&ctx->state, dump.policy, dump.maxattr); if (err) goto err_free_state; } if (!ctx->state) return -ENODATA; ctx->dump_map = 1; return 0; } ctx->op_iter = kmalloc(sizeof(*ctx->op_iter), GFP_KERNEL); if (!ctx->op_iter) return -ENOMEM; genl_op_iter_init(rt, ctx->op_iter); ctx->dump_map = genl_op_iter_next(ctx->op_iter); for (genl_op_iter_init(rt, &i); genl_op_iter_next(&i); ) { if (i.doit.policy) { err = netlink_policy_dump_add_policy(&ctx->state, i.doit.policy, i.doit.maxattr); if (err) goto err_free_state; } if (i.dumpit.policy) { err = netlink_policy_dump_add_policy(&ctx->state, i.dumpit.policy, i.dumpit.maxattr); if (err) goto err_free_state; } } if (!ctx->state) { err = -ENODATA; goto err_free_op_iter; } return 0; err_free_state: netlink_policy_dump_free(ctx->state); err_free_op_iter: kfree(ctx->op_iter); return err; } static void *ctrl_dumppolicy_prep(struct sk_buff *skb, struct netlink_callback *cb) { struct ctrl_dump_policy_ctx *ctx = (void *)cb->ctx; void *hdr; hdr = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq, &genl_ctrl, NLM_F_MULTI, CTRL_CMD_GETPOLICY); if (!hdr) return NULL; if (nla_put_u16(skb, CTRL_ATTR_FAMILY_ID, ctx->fam_id)) return NULL; return hdr; } static int ctrl_dumppolicy_put_op(struct sk_buff *skb, struct netlink_callback *cb, struct genl_split_ops *doit, struct genl_split_ops *dumpit) { struct ctrl_dump_policy_ctx *ctx = (void *)cb->ctx; struct nlattr *nest_pol, *nest_op; void *hdr; int idx; /* skip if we have nothing to show */ if (!doit->policy && !dumpit->policy) return 0; hdr = ctrl_dumppolicy_prep(skb, cb); if (!hdr) return -ENOBUFS; nest_pol = nla_nest_start(skb, CTRL_ATTR_OP_POLICY); if (!nest_pol) goto err; nest_op = nla_nest_start(skb, doit->cmd); if (!nest_op) goto err; if (doit->policy) { idx = netlink_policy_dump_get_policy_idx(ctx->state, doit->policy, doit->maxattr); if (nla_put_u32(skb, CTRL_ATTR_POLICY_DO, idx)) goto err; } if (dumpit->policy) { idx = netlink_policy_dump_get_policy_idx(ctx->state, dumpit->policy, dumpit->maxattr); if (nla_put_u32(skb, CTRL_ATTR_POLICY_DUMP, idx)) goto err; } nla_nest_end(skb, nest_op); nla_nest_end(skb, nest_pol); genlmsg_end(skb, hdr); return 0; err: genlmsg_cancel(skb, hdr); return -ENOBUFS; } static int ctrl_dumppolicy(struct sk_buff *skb, struct netlink_callback *cb) { struct ctrl_dump_policy_ctx *ctx = (void *)cb->ctx; void *hdr; if (ctx->dump_map) { if (ctx->single_op) { struct genl_split_ops doit, dumpit; if (WARN_ON(genl_get_cmd_both(ctx->op, ctx->rt, &doit, &dumpit))) return -ENOENT; if (ctrl_dumppolicy_put_op(skb, cb, &doit, &dumpit)) return skb->len; /* done with the per-op policy index list */ ctx->dump_map = 0; } while (ctx->dump_map) { if (ctrl_dumppolicy_put_op(skb, cb, &ctx->op_iter->doit, &ctx->op_iter->dumpit)) return skb->len; ctx->dump_map = genl_op_iter_next(ctx->op_iter); } } while (netlink_policy_dump_loop(ctx->state)) { struct nlattr *nest; hdr = ctrl_dumppolicy_prep(skb, cb); if (!hdr) goto nla_put_failure; nest = nla_nest_start(skb, CTRL_ATTR_POLICY); if (!nest) goto nla_put_failure; if (netlink_policy_dump_write(skb, ctx->state)) goto nla_put_failure; nla_nest_end(skb, nest); genlmsg_end(skb, hdr); } return skb->len; nla_put_failure: genlmsg_cancel(skb, hdr); return skb->len; } static int ctrl_dumppolicy_done(struct netlink_callback *cb) { struct ctrl_dump_policy_ctx *ctx = (void *)cb->ctx; kfree(ctx->op_iter); netlink_policy_dump_free(ctx->state); return 0; } static const struct genl_split_ops genl_ctrl_ops[] = { { .cmd = CTRL_CMD_GETFAMILY, .validate = GENL_DONT_VALIDATE_STRICT, .policy = ctrl_policy_family, .maxattr = ARRAY_SIZE(ctrl_policy_family) - 1, .doit = ctrl_getfamily, .flags = GENL_CMD_CAP_DO, }, { .cmd = CTRL_CMD_GETFAMILY, .validate = GENL_DONT_VALIDATE_DUMP, .policy = ctrl_policy_family, .maxattr = ARRAY_SIZE(ctrl_policy_family) - 1, .dumpit = ctrl_dumpfamily, .flags = GENL_CMD_CAP_DUMP, }, { .cmd = CTRL_CMD_GETPOLICY, .policy = ctrl_policy_policy, .maxattr = ARRAY_SIZE(ctrl_policy_policy) - 1, .start = ctrl_dumppolicy_start, .dumpit = ctrl_dumppolicy, .done = ctrl_dumppolicy_done, .flags = GENL_CMD_CAP_DUMP, }, }; static const struct genl_multicast_group genl_ctrl_groups[] = { { .name = "notify", }, }; static struct genl_family genl_ctrl __ro_after_init = { .module = THIS_MODULE, .split_ops = genl_ctrl_ops, .n_split_ops = ARRAY_SIZE(genl_ctrl_ops), .resv_start_op = CTRL_CMD_GETPOLICY + 1, .mcgrps = genl_ctrl_groups, .n_mcgrps = ARRAY_SIZE(genl_ctrl_groups), .id = GENL_ID_CTRL, .name = "nlctrl", .version = 0x2, .netnsok = true, }; static int genl_bind(struct net *net, int group) { const struct genl_family *family; unsigned int id; int ret = 0; down_read(&cb_lock); idr_for_each_entry(&genl_fam_idr, family, id) { const struct genl_multicast_group *grp; int i; if (family->n_mcgrps == 0) continue; i = group - family->mcgrp_offset; if (i < 0 || i >= family->n_mcgrps) continue; grp = &family->mcgrps[i]; if ((grp->flags & GENL_MCAST_CAP_NET_ADMIN) && !ns_capable(net->user_ns, CAP_NET_ADMIN)) ret = -EPERM; if ((grp->flags & GENL_MCAST_CAP_SYS_ADMIN) && !ns_capable(net->user_ns, CAP_SYS_ADMIN)) ret = -EPERM; break; } up_read(&cb_lock); return ret; } 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, .release = genl_release, }; /* 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 err; err = genl_register_family(&genl_ctrl); 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); } core_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(const 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(const 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; if (WARN_ON_ONCE(group >= family->n_mcgrps)) return; group = family->mcgrp_offset + group; nlmsg_notify(sk, skb, info->snd_portid, group, nlmsg_report(info->nlhdr), flags); } EXPORT_SYMBOL(genl_notify);