X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=net%2Fnetlink%2Fgenetlink.c;h=3e1191cecaf03131d5ad2ff321f171f9168bc6ad;hb=6f756a8c36bf54d0afb1d457082b3e3033d951a7;hp=75bb47a898dd7a7de700f5fd13e250967bae5c10;hpb=fe4944e59c357f945f81bc67edb7ed1392e875ad;p=safe%2Fjmp%2Flinux-2.6 diff --git a/net/netlink/genetlink.c b/net/netlink/genetlink.c index 75bb47a..3e1191c 100644 --- a/net/netlink/genetlink.c +++ b/net/netlink/genetlink.c @@ -3,6 +3,7 @@ * * Authors: Jamal Hadi Salim * Thomas Graf + * Johannes Berg */ #include @@ -13,6 +14,7 @@ #include #include #include +#include #include #include @@ -20,28 +22,30 @@ struct sock *genl_sock = NULL; static DEFINE_MUTEX(genl_mutex); /* serialization of message processing */ -static void genl_lock(void) +static inline void genl_lock(void) { mutex_lock(&genl_mutex); } -static int genl_trylock(void) -{ - return !mutex_trylock(&genl_mutex); -} - -static void genl_unlock(void) +static inline void genl_unlock(void) { mutex_unlock(&genl_mutex); - - if (genl_sock && genl_sock->sk_receive_queue.qlen) - genl_sock->sk_data_ready(genl_sock, 0); } #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. + */ +static unsigned long mc_group_start = 0x1; +static unsigned long *mc_groups = &mc_group_start; +static unsigned long mc_groups_longs = 1; static int genl_ctrl_event(int event, void *data); @@ -116,6 +120,120 @@ static inline u16 genl_generate_id(void) return id_gen_idx; } +static struct genl_multicast_group notify_grp; + +/** + * genl_register_mc_group - register a multicast group + * + * Registers the specified multicast group and notifies userspace + * about the new group. + * + * Returns 0 on success or a negative error code. + * + * @family: The generic netlink family the group shall be registered for. + * @grp: The group to register, must have a name. + */ +int genl_register_mc_group(struct genl_family *family, + struct genl_multicast_group *grp) +{ + int id; + unsigned long *new_groups; + int err; + + BUG_ON(grp->name[0] == '\0'); + + genl_lock(); + + /* special-case our own group */ + if (grp == ¬ify_grp) + id = GENL_ID_CTRL; + else + id = find_first_zero_bit(mc_groups, + mc_groups_longs * BITS_PER_LONG); + + + if (id >= mc_groups_longs * BITS_PER_LONG) { + size_t nlen = (mc_groups_longs + 1) * sizeof(unsigned long); + + if (mc_groups == &mc_group_start) { + new_groups = kzalloc(nlen, GFP_KERNEL); + if (!new_groups) { + err = -ENOMEM; + goto out; + } + mc_groups = new_groups; + *mc_groups = mc_group_start; + } else { + new_groups = krealloc(mc_groups, nlen, GFP_KERNEL); + if (!new_groups) { + err = -ENOMEM; + goto out; + } + mc_groups = new_groups; + mc_groups[mc_groups_longs] = 0; + } + mc_groups_longs++; + } + + err = netlink_change_ngroups(genl_sock, + mc_groups_longs * BITS_PER_LONG); + if (err) + goto out; + + grp->id = id; + set_bit(id, mc_groups); + list_add_tail(&grp->list, &family->mcast_groups); + grp->family = family; + + genl_ctrl_event(CTRL_CMD_NEWMCAST_GRP, grp); + out: + genl_unlock(); + return err; +} +EXPORT_SYMBOL(genl_register_mc_group); + +static void __genl_unregister_mc_group(struct genl_family *family, + struct genl_multicast_group *grp) +{ + BUG_ON(grp->family != family); + netlink_clear_multicast_users(genl_sock, grp->id); + clear_bit(grp->id, mc_groups); + list_del(&grp->list); + genl_ctrl_event(CTRL_CMD_DELMCAST_GRP, grp); + grp->id = 0; + grp->family = NULL; +} + +/** + * genl_unregister_mc_group - unregister a multicast group + * + * Unregisters the specified multicast group and notifies userspace + * about it. All current listeners on the group are removed. + * + * Note: It is not necessary to unregister all multicast groups before + * unregistering the family, unregistering the family will cause + * all assigned multicast groups to be unregistered automatically. + * + * @family: Generic netlink family the group belongs to. + * @grp: The group to unregister, must have been registered successfully + * previously. + */ +void genl_unregister_mc_group(struct genl_family *family, + struct genl_multicast_group *grp) +{ + genl_lock(); + __genl_unregister_mc_group(family, grp); + genl_unlock(); +} + +static void genl_unregister_mc_groups(struct genl_family *family) +{ + struct genl_multicast_group *grp, *tmp; + + list_for_each_entry_safe(grp, tmp, &family->mcast_groups, list) + __genl_unregister_mc_group(family, grp); +} + /** * genl_register_ops - register generic netlink operations * @family: generic netlink family @@ -143,6 +261,13 @@ int genl_register_ops(struct genl_family *family, struct genl_ops *ops) goto errout; } + if (ops->dumpit) + ops->flags |= GENL_CMD_CAP_DUMP; + if (ops->doit) + ops->flags |= GENL_CMD_CAP_DO; + if (ops->policy) + ops->flags |= GENL_CMD_CAP_HASPOL; + genl_lock(); list_add_tail(&ops->ops_list, &family->ops_list); genl_unlock(); @@ -209,6 +334,7 @@ int genl_register_family(struct genl_family *family) goto errout; INIT_LIST_HEAD(&family->ops_list); + INIT_LIST_HEAD(&family->mcast_groups); genl_lock(); @@ -270,6 +396,8 @@ int genl_unregister_family(struct genl_family *family) genl_lock(); + 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; @@ -288,66 +416,49 @@ int genl_unregister_family(struct genl_family *family) return -ENOENT; } -static int genl_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, - int *errp) +static int genl_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh) { struct genl_ops *ops; struct genl_family *family; struct genl_info info; struct genlmsghdr *hdr = nlmsg_data(nlh); - int hdrlen, err = -EINVAL; - - if (!(nlh->nlmsg_flags & NLM_F_REQUEST)) - goto ignore; + int hdrlen, err; - if (nlh->nlmsg_type < NLMSG_MIN_TYPE) - goto ignore; - - family = genl_family_find_byid(nlh->nlmsg_type); - if (family == NULL) { - err = -ENOENT; - goto errout; - } + family = genl_family_find_byid(nlh->nlmsg_type); + if (family == NULL) + 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, CAP_NET_ADMIN)) { - err = -EPERM; - goto errout; - } + if ((ops->flags & GENL_ADMIN_PERM) && + security_netlink_recv(skb, CAP_NET_ADMIN)) + return -EPERM; if (nlh->nlmsg_flags & NLM_F_DUMP) { - if (ops->dumpit == NULL) { - err = -EOPNOTSUPP; - goto errout; - } + if (ops->dumpit == NULL) + return -EOPNOTSUPP; - *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; + genl_unlock(); + err = netlink_dump_start(genl_sock, skb, nlh, + ops->dumpit, ops->done); + genl_lock(); + return err; } - 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, ops->policy); if (err < 0) - goto errout; + return err; } info.snd_seq = nlh->nlmsg_seq; @@ -357,50 +468,134 @@ static int genl_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, info.userhdr = nlmsg_data(nlh) + GENL_HDRLEN; info.attrs = family->attrbuf; - *errp = err = ops->doit(skb, &info); - return err; - -ignore: - return 0; - -errout: - *errp = err; - return -1; + return ops->doit(skb, &info); } -static void genl_rcv(struct sock *sk, int len) +static void genl_rcv(struct sk_buff *skb) { - unsigned int qlen = 0; - - do { - if (genl_trylock()) - return; - netlink_run_queue(sk, &qlen, genl_rcv_msg); - genl_unlock(); - } while (qlen && genl_sock && genl_sock->sk_receive_queue.qlen); + genl_lock(); + netlink_rcv_skb(skb, &genl_rcv_msg); + genl_unlock(); } /************************************************************************** * Controller **************************************************************************/ +static struct genl_family genl_ctrl = { + .id = GENL_ID_CTRL, + .name = "nlctrl", + .version = 0x2, + .maxattr = CTRL_ATTR_MAX, +}; + static int ctrl_fill_info(struct genl_family *family, u32 pid, 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, pid, 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); + 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); + + if (!list_empty(&family->ops_list)) { + struct nlattr *nla_ops; + struct genl_ops *ops; + int idx = 1; + + nla_ops = nla_nest_start(skb, CTRL_ATTR_OPS); + if (nla_ops == NULL) + goto nla_put_failure; + + list_for_each_entry(ops, &family->ops_list, ops_list) { + struct nlattr *nest; + + nest = nla_nest_start(skb, idx++); + if (nest == NULL) + goto nla_put_failure; + + NLA_PUT_U32(skb, CTRL_ATTR_OP_ID, ops->cmd); + NLA_PUT_U32(skb, CTRL_ATTR_OP_FLAGS, ops->flags); + + nla_nest_end(skb, nest); + } + + nla_nest_end(skb, nla_ops); + } + + if (!list_empty(&family->mcast_groups)) { + struct genl_multicast_group *grp; + struct nlattr *nla_grps; + int idx = 1; + + nla_grps = nla_nest_start(skb, CTRL_ATTR_MCAST_GROUPS); + if (nla_grps == NULL) + goto nla_put_failure; + + list_for_each_entry(grp, &family->mcast_groups, list) { + struct nlattr *nest; + + nest = nla_nest_start(skb, idx++); + if (nest == NULL) + goto nla_put_failure; + + NLA_PUT_U32(skb, CTRL_ATTR_MCAST_GRP_ID, grp->id); + NLA_PUT_STRING(skb, CTRL_ATTR_MCAST_GRP_NAME, + grp->name); + + 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_multicast_group *grp, u32 pid, + u32 seq, u32 flags, struct sk_buff *skb, + u8 cmd) +{ + void *hdr; + struct nlattr *nla_grps; + struct nlattr *nest; + + hdr = genlmsg_put(skb, pid, seq, &genl_ctrl, flags, cmd); + if (hdr == NULL) + return -1; + + NLA_PUT_STRING(skb, CTRL_ATTR_FAMILY_NAME, grp->family->name); + NLA_PUT_U16(skb, CTRL_ATTR_FAMILY_ID, grp->family->id); + + 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; + + NLA_PUT_U32(skb, CTRL_ATTR_MCAST_GRP_ID, grp->id); + NLA_PUT_STRING(skb, CTRL_ATTR_MCAST_GRP_NAME, + grp->name); + + 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) @@ -434,13 +629,13 @@ 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 pid, int seq, u8 cmd) { struct sk_buff *skb; int err; - skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL); + skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); if (skb == NULL) return ERR_PTR(-ENOBUFS); @@ -453,9 +648,29 @@ 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 struct sk_buff *ctrl_build_mcgrp_msg(struct genl_multicast_group *grp, + u32 pid, 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(grp, pid, 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_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) @@ -470,12 +685,9 @@ static int ctrl_getfamily(struct sk_buff *skb, struct genl_info *info) } 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); } @@ -484,14 +696,14 @@ static int ctrl_getfamily(struct sk_buff *skb, struct genl_info *info) goto errout; } - msg = ctrl_build_msg(res, info->snd_pid, info->snd_seq, - CTRL_CMD_NEWFAMILY); + msg = ctrl_build_family_msg(res, info->snd_pid, info->snd_seq, + CTRL_CMD_NEWFAMILY); if (IS_ERR(msg)) { err = PTR_ERR(msg); goto errout; } - err = genlmsg_unicast(msg, info->snd_pid); + err = genlmsg_reply(msg, info); errout: return err; } @@ -506,11 +718,19 @@ static int genl_ctrl_event(int event, void *data) switch (event) { case CTRL_CMD_NEWFAMILY: case CTRL_CMD_DELFAMILY: - msg = ctrl_build_msg(data, 0, 0, event); + msg = ctrl_build_family_msg(data, 0, 0, event); + if (IS_ERR(msg)) + return PTR_ERR(msg); + + genlmsg_multicast(msg, 0, GENL_ID_CTRL, GFP_KERNEL); + break; + case CTRL_CMD_NEWMCAST_GRP: + case CTRL_CMD_DELMCAST_GRP: + msg = ctrl_build_mcgrp_msg(data, 0, 0, event); if (IS_ERR(msg)) return PTR_ERR(msg); - genlmsg_multicast(msg, 0, GENL_ID_CTRL); + genlmsg_multicast(msg, 0, GENL_ID_CTRL, GFP_KERNEL); break; } @@ -524,11 +744,8 @@ static struct genl_ops genl_ctrl_ops = { .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 notify_grp = { + .name = "notify", }; static int __init genl_init(void) @@ -547,11 +764,17 @@ static int __init genl_init(void) 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); + + /* we'll bump the group number right afterwards */ + genl_sock = netlink_kernel_create(&init_net, NETLINK_GENERIC, 0, + genl_rcv, &genl_mutex, THIS_MODULE); if (genl_sock == NULL) panic("GENL: Cannot initialize generic netlink\n"); + err = genl_register_mc_group(&genl_ctrl, ¬ify_grp); + if (err < 0) + goto errout_register; + return 0; errout_register: