diff options
author | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-07-19 10:23:21 -0700 |
---|---|---|
committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-07-19 10:23:21 -0700 |
commit | ce8c2293be47999584908069e78bf6d94beadc53 (patch) | |
tree | dfd6909e6866998d2103341b1e1af8c129d0cea8 /net/netlink | |
parent | 41e9d344bf52c57ec16648d08618b61d3f1d4bdc (diff) | |
parent | ee6a99b539a50b4e9398938a0a6d37f8bf911550 (diff) |
Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
* 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6: (25 commits)
[TG3]: Fix msi issue with kexec/kdump.
[NET] XFRM: Fix whitespace errors.
[NET] TIPC: Fix whitespace errors.
[NET] SUNRPC: Fix whitespace errors.
[NET] SCTP: Fix whitespace errors.
[NET] RXRPC: Fix whitespace errors.
[NET] ROSE: Fix whitespace errors.
[NET] RFKILL: Fix whitespace errors.
[NET] PACKET: Fix whitespace errors.
[NET] NETROM: Fix whitespace errors.
[NET] NETFILTER: Fix whitespace errors.
[NET] IPV4: Fix whitespace errors.
[NET] DCCP: Fix whitespace errors.
[NET] CORE: Fix whitespace errors.
[NET] BLUETOOTH: Fix whitespace errors.
[NET] AX25: Fix whitespace errors.
[PATCH] mac80211: remove rtnl locking in ieee80211_sta.c
[PATCH] mac80211: fix GCC warning on 64bit platforms
[GENETLINK]: Dynamic multicast groups.
[NETLIKN]: Allow removing multicast groups.
...
Diffstat (limited to 'net/netlink')
-rw-r--r-- | net/netlink/af_netlink.c | 161 | ||||
-rw-r--r-- | net/netlink/genetlink.c | 235 |
2 files changed, 354 insertions, 42 deletions
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c index 641cfbc278d..5681ce3aebc 100644 --- a/net/netlink/af_netlink.c +++ b/net/netlink/af_netlink.c @@ -62,6 +62,7 @@ #include <net/netlink.h> #define NLGRPSZ(x) (ALIGN(x, sizeof(unsigned long) * 8) / 8) +#define NLGRPLONGS(x) (NLGRPSZ(x)/sizeof(unsigned long)) struct netlink_sock { /* struct sock has to be the first member of netlink_sock */ @@ -314,10 +315,12 @@ netlink_update_listeners(struct sock *sk) unsigned long mask; unsigned int i; - for (i = 0; i < NLGRPSZ(tbl->groups)/sizeof(unsigned long); i++) { + for (i = 0; i < NLGRPLONGS(tbl->groups); i++) { mask = 0; - sk_for_each_bound(sk, node, &tbl->mc_list) - mask |= nlk_sk(sk)->groups[i]; + sk_for_each_bound(sk, node, &tbl->mc_list) { + if (i < NLGRPLONGS(nlk_sk(sk)->ngroups)) + mask |= nlk_sk(sk)->groups[i]; + } tbl->listeners[i] = mask; } /* this function is only called with the netlink table "grabbed", which @@ -555,26 +558,37 @@ netlink_update_subscriptions(struct sock *sk, unsigned int subscriptions) nlk->subscriptions = subscriptions; } -static int netlink_alloc_groups(struct sock *sk) +static int netlink_realloc_groups(struct sock *sk) { struct netlink_sock *nlk = nlk_sk(sk); unsigned int groups; + unsigned long *new_groups; int err = 0; - netlink_lock_table(); + netlink_table_grab(); + groups = nl_table[sk->sk_protocol].groups; - if (!nl_table[sk->sk_protocol].registered) + if (!nl_table[sk->sk_protocol].registered) { err = -ENOENT; - netlink_unlock_table(); + goto out_unlock; + } - if (err) - return err; + if (nlk->ngroups >= groups) + goto out_unlock; - nlk->groups = kzalloc(NLGRPSZ(groups), GFP_KERNEL); - if (nlk->groups == NULL) - return -ENOMEM; + new_groups = krealloc(nlk->groups, NLGRPSZ(groups), GFP_ATOMIC); + if (new_groups == NULL) { + err = -ENOMEM; + goto out_unlock; + } + memset((char*)new_groups + NLGRPSZ(nlk->ngroups), 0, + NLGRPSZ(groups) - NLGRPSZ(nlk->ngroups)); + + nlk->groups = new_groups; nlk->ngroups = groups; - return 0; + out_unlock: + netlink_table_ungrab(); + return err; } static int netlink_bind(struct socket *sock, struct sockaddr *addr, int addr_len) @@ -591,11 +605,9 @@ static int netlink_bind(struct socket *sock, struct sockaddr *addr, int addr_len if (nladdr->nl_groups) { if (!netlink_capable(sock, NL_NONROOT_RECV)) return -EPERM; - if (nlk->groups == NULL) { - err = netlink_alloc_groups(sk); - if (err) - return err; - } + err = netlink_realloc_groups(sk); + if (err) + return err; } if (nlk->pid) { @@ -839,10 +851,18 @@ retry: int netlink_has_listeners(struct sock *sk, unsigned int group) { int res = 0; + unsigned long *listeners; BUG_ON(!(nlk_sk(sk)->flags & NETLINK_KERNEL_SOCKET)); + + rcu_read_lock(); + listeners = rcu_dereference(nl_table[sk->sk_protocol].listeners); + if (group - 1 < nl_table[sk->sk_protocol].groups) - res = test_bit(group - 1, nl_table[sk->sk_protocol].listeners); + res = test_bit(group - 1, listeners); + + rcu_read_unlock(); + return res; } EXPORT_SYMBOL_GPL(netlink_has_listeners); @@ -1007,6 +1027,23 @@ void netlink_set_err(struct sock *ssk, u32 pid, u32 group, int code) read_unlock(&nl_table_lock); } +/* must be called with netlink table grabbed */ +static void netlink_update_socket_mc(struct netlink_sock *nlk, + unsigned int group, + int is_new) +{ + int old, new = !!is_new, subscriptions; + + old = test_bit(group - 1, nlk->groups); + subscriptions = nlk->subscriptions - old + new; + if (new) + __set_bit(group - 1, nlk->groups); + else + __clear_bit(group - 1, nlk->groups); + netlink_update_subscriptions(&nlk->sk, subscriptions); + netlink_update_listeners(&nlk->sk); +} + static int netlink_setsockopt(struct socket *sock, int level, int optname, char __user *optval, int optlen) { @@ -1032,27 +1069,16 @@ static int netlink_setsockopt(struct socket *sock, int level, int optname, break; case NETLINK_ADD_MEMBERSHIP: case NETLINK_DROP_MEMBERSHIP: { - unsigned int subscriptions; - int old, new = optname == NETLINK_ADD_MEMBERSHIP ? 1 : 0; - if (!netlink_capable(sock, NL_NONROOT_RECV)) return -EPERM; - if (nlk->groups == NULL) { - err = netlink_alloc_groups(sk); - if (err) - return err; - } + err = netlink_realloc_groups(sk); + if (err) + return err; if (!val || val - 1 >= nlk->ngroups) return -EINVAL; netlink_table_grab(); - old = test_bit(val - 1, nlk->groups); - subscriptions = nlk->subscriptions - old + new; - if (new) - __set_bit(val - 1, nlk->groups); - else - __clear_bit(val - 1, nlk->groups); - netlink_update_subscriptions(sk, subscriptions); - netlink_update_listeners(sk); + netlink_update_socket_mc(nlk, val, + optname == NETLINK_ADD_MEMBERSHIP); netlink_table_ungrab(); err = 0; break; @@ -1328,6 +1354,71 @@ out_sock_release: return NULL; } +/** + * netlink_change_ngroups - change number of multicast groups + * + * This changes the number of multicast groups that are available + * on a certain netlink family. Note that it is not possible to + * change the number of groups to below 32. Also note that it does + * not implicitly call netlink_clear_multicast_users() when the + * number of groups is reduced. + * + * @sk: The kernel netlink socket, as returned by netlink_kernel_create(). + * @groups: The new number of groups. + */ +int netlink_change_ngroups(struct sock *sk, unsigned int groups) +{ + unsigned long *listeners, *old = NULL; + struct netlink_table *tbl = &nl_table[sk->sk_protocol]; + int err = 0; + + if (groups < 32) + groups = 32; + + netlink_table_grab(); + if (NLGRPSZ(tbl->groups) < NLGRPSZ(groups)) { + listeners = kzalloc(NLGRPSZ(groups), GFP_ATOMIC); + if (!listeners) { + err = -ENOMEM; + goto out_ungrab; + } + old = tbl->listeners; + memcpy(listeners, old, NLGRPSZ(tbl->groups)); + rcu_assign_pointer(tbl->listeners, listeners); + } + tbl->groups = groups; + + out_ungrab: + netlink_table_ungrab(); + synchronize_rcu(); + kfree(old); + return err; +} +EXPORT_SYMBOL(netlink_change_ngroups); + +/** + * netlink_clear_multicast_users - kick off multicast listeners + * + * This function removes all listeners from the given group. + * @ksk: The kernel netlink socket, as returned by + * netlink_kernel_create(). + * @group: The multicast group to clear. + */ +void netlink_clear_multicast_users(struct sock *ksk, unsigned int group) +{ + struct sock *sk; + struct hlist_node *node; + struct netlink_table *tbl = &nl_table[ksk->sk_protocol]; + + netlink_table_grab(); + + sk_for_each_bound(sk, node, &tbl->mc_list) + netlink_update_socket_mc(nlk_sk(sk), group, 0); + + netlink_table_ungrab(); +} +EXPORT_SYMBOL(netlink_clear_multicast_users); + void netlink_set_nonroot(int protocol, unsigned int flags) { if ((unsigned int)protocol < MAX_LINKS) diff --git a/net/netlink/genetlink.c b/net/netlink/genetlink.c index b9ab62f938d..e146531faf1 100644 --- a/net/netlink/genetlink.c +++ b/net/netlink/genetlink.c @@ -3,6 +3,7 @@ * * Authors: Jamal Hadi Salim * Thomas Graf <tgraf@suug.ch> + * Johannes Berg <johannes@sipsolutions.net> */ #include <linux/module.h> @@ -13,6 +14,7 @@ #include <linux/string.h> #include <linux/skbuff.h> #include <linux/mutex.h> +#include <linux/bitmap.h> #include <net/sock.h> #include <net/genetlink.h> @@ -42,6 +44,16 @@ static void genl_unlock(void) #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 +128,114 @@ 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, + sizeof(unsigned long) * NETLINK_GENERIC); + 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 0; +} +EXPORT_SYMBOL(genl_register_mc_group); + +/** + * 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) +{ + BUG_ON(grp->family != family); + genl_lock(); + 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_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 @@ -216,6 +336,7 @@ int genl_register_family(struct genl_family *family) goto errout; INIT_LIST_HEAD(&family->ops_list); + INIT_LIST_HEAD(&family->mcast_groups); genl_lock(); @@ -275,6 +396,8 @@ int genl_unregister_family(struct genl_family *family) { struct genl_family *rc; + genl_unregister_mc_groups(family); + genl_lock(); list_for_each_entry(rc, genl_family_chain(family->id), family_list) { @@ -410,6 +533,67 @@ static int ctrl_fill_info(struct genl_family *family, u32 pid, u32 seq, 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: + return genlmsg_cancel(skb, hdr); +} + +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: @@ -453,8 +637,8 @@ 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; @@ -472,6 +656,25 @@ static struct sk_buff *ctrl_build_msg(struct genl_family *family, u32 pid, return skb; } +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_NUL_STRING, @@ -501,8 +704,8 @@ 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; @@ -523,7 +726,15 @@ 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); @@ -541,6 +752,10 @@ static struct genl_ops genl_ctrl_ops = { .policy = ctrl_policy, }; +static struct genl_multicast_group notify_grp = { + .name = "notify", +}; + static int __init genl_init(void) { int i, err; @@ -557,11 +772,17 @@ 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, NULL, THIS_MODULE); + + /* we'll bump the group number right afterwards */ + genl_sock = netlink_kernel_create(NETLINK_GENERIC, 0, genl_rcv, + NULL, 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: |