]> nv-tegra.nvidia Code Review - linux-2.6.git/blobdiff - net/netlink/genetlink.c
genetlink: fix netns vs. netlink table locking
[linux-2.6.git] / net / netlink / genetlink.c
index eed4c6a8afc0256fb6c3e1e267da6ca21233e823..566941e03363fbdd7591ded5ed16b41f0a903c7c 100644 (file)
@@ -18,8 +18,6 @@
 #include <net/sock.h>
 #include <net/genetlink.h>
 
-struct sock *genl_sock = NULL;
-
 static DEFINE_MUTEX(genl_mutex); /* serialization of message processing */
 
 static inline void genl_lock(void)
@@ -138,7 +136,7 @@ int genl_register_mc_group(struct genl_family *family,
 {
        int id;
        unsigned long *new_groups;
-       int err;
+       int err = 0;
 
        BUG_ON(grp->name[0] == '\0');
 
@@ -175,10 +173,34 @@ int genl_register_mc_group(struct genl_family *family,
                mc_groups_longs++;
        }
 
-       err = netlink_change_ngroups(genl_sock,
-                                    mc_groups_longs * BITS_PER_LONG);
-       if (err)
-               goto out;
+       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.
+                                */
+                               rcu_read_unlock();
+                               netlink_table_ungrab();
+                               goto out;
+                       }
+               }
+               rcu_read_unlock();
+               netlink_table_ungrab();
+       } else {
+               err = netlink_change_ngroups(init_net.genl_sock,
+                                            mc_groups_longs * BITS_PER_LONG);
+               if (err)
+                       goto out;
+       }
 
        grp->id = id;
        set_bit(id, mc_groups);
@@ -195,8 +217,14 @@ EXPORT_SYMBOL(genl_register_mc_group);
 static void __genl_unregister_mc_group(struct genl_family *family,
                                       struct genl_multicast_group *grp)
 {
+       struct net *net;
        BUG_ON(grp->family != family);
-       netlink_clear_multicast_users(genl_sock, grp->id);
+
+       rcu_read_lock();
+       for_each_net_rcu(net)
+               netlink_clear_multicast_users(net->genl_sock, grp->id);
+       rcu_read_unlock();
+
        clear_bit(grp->id, mc_groups);
        list_del(&grp->list);
        genl_ctrl_event(CTRL_CMD_DELMCAST_GRP, grp);
@@ -467,6 +495,7 @@ static int genl_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 {
        struct genl_ops *ops;
        struct genl_family *family;
+       struct net *net = sock_net(skb->sk);
        struct genl_info info;
        struct genlmsghdr *hdr = nlmsg_data(nlh);
        int hdrlen, err;
@@ -475,6 +504,10 @@ static int genl_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
        if (family == NULL)
                return -ENOENT;
 
+       /* 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;
@@ -492,7 +525,7 @@ static int genl_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
                        return -EOPNOTSUPP;
 
                genl_unlock();
-               err = netlink_dump_start(genl_sock, skb, nlh,
+               err = netlink_dump_start(net->genl_sock, skb, nlh,
                                         ops->dumpit, ops->done);
                genl_lock();
                return err;
@@ -514,6 +547,7 @@ static int genl_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
        info.genlhdr = nlmsg_data(nlh);
        info.userhdr = nlmsg_data(nlh) + GENL_HDRLEN;
        info.attrs = family->attrbuf;
+       genl_info_net_set(&info, net);
 
        return ops->doit(skb, &info);
 }
@@ -534,6 +568,7 @@ static struct genl_family genl_ctrl = {
        .name = "nlctrl",
        .version = 0x2,
        .maxattr = CTRL_ATTR_MAX,
+       .netnsok = true,
 };
 
 static int ctrl_fill_info(struct genl_family *family, u32 pid, u32 seq,
@@ -650,6 +685,7 @@ 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];
 
@@ -658,6 +694,8 @@ static int ctrl_dumpfamily(struct sk_buff *skb, struct netlink_callback *cb)
                        continue;
                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,
@@ -729,6 +767,7 @@ 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]) {
@@ -736,49 +775,61 @@ static int ctrl_getfamily(struct sk_buff *skb, struct genl_info *info)
 
                name = nla_data(info->attrs[CTRL_ATTR_FAMILY_NAME]);
                res = genl_family_find_byname(name);
+               err = -ENOENT;
        }
 
-       if (res == NULL) {
-               err = -ENOENT;
-               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;
        }
 
        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;
-       }
+       if (IS_ERR(msg))
+               return PTR_ERR(msg);
 
-       err = genlmsg_reply(msg, info);
-errout:
-       return err;
+       return genlmsg_reply(msg, info);
 }
 
 static int genl_ctrl_event(int event, void *data)
 {
        struct sk_buff *msg;
+       struct genl_family *family;
+       struct genl_multicast_group *grp;
 
-       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_family_msg(data, 0, 0, event);
-               if (IS_ERR(msg))
-                       return PTR_ERR(msg);
-
-               genlmsg_multicast(msg, 0, GENL_ID_CTRL, GFP_KERNEL);
+               family = data;
+               msg = ctrl_build_family_msg(family, 0, 0, event);
                break;
        case CTRL_CMD_NEWMCAST_GRP:
        case CTRL_CMD_DELMCAST_GRP:
+               grp = data;
+               family = grp->family;
                msg = ctrl_build_mcgrp_msg(data, 0, 0, event);
-               if (IS_ERR(msg))
-                       return PTR_ERR(msg);
-
-               genlmsg_multicast(msg, 0, GENL_ID_CTRL, GFP_KERNEL);
                break;
+       default:
+               return -EINVAL;
+       }
+
+       if (IS_ERR(msg))
+               return PTR_ERR(msg);
+
+       if (!family->netnsok) {
+               genlmsg_multicast_netns(&init_net, msg, 0,
+                                       GENL_ID_CTRL, GFP_KERNEL);
+       } else {
+               rcu_read_lock();
+               genlmsg_multicast_allns(msg, 0, GENL_ID_CTRL, GFP_ATOMIC);
+               rcu_read_unlock();
        }
 
        return 0;
@@ -795,6 +846,33 @@ static struct genl_multicast_group notify_grp = {
        .name           = "notify",
 };
 
+static int __net_init genl_pernet_init(struct net *net)
+{
+       /* we'll bump the group number right afterwards */
+       net->genl_sock = netlink_kernel_create(net, NETLINK_GENERIC, 0,
+                                              genl_rcv, &genl_mutex,
+                                              THIS_MODULE);
+
+       if (!net->genl_sock && net_eq(net, &init_net))
+               panic("GENL: Cannot initialize generic netlink\n");
+
+       if (!net->genl_sock)
+               return -ENOMEM;
+
+       return 0;
+}
+
+static void __net_exit genl_pernet_exit(struct net *net)
+{
+       netlink_kernel_release(net->genl_sock);
+       net->genl_sock = NULL;
+}
+
+static struct pernet_operations genl_pernet_ops = {
+       .init = genl_pernet_init,
+       .exit = genl_pernet_exit,
+};
+
 static int __init genl_init(void)
 {
        int i, err;
@@ -804,36 +882,67 @@ static int __init genl_init(void)
 
        err = genl_register_family(&genl_ctrl);
        if (err < 0)
-               goto errout;
+               goto problem;
 
        err = genl_register_ops(&genl_ctrl, &genl_ctrl_ops);
        if (err < 0)
-               goto errout_register;
+               goto problem;
 
        netlink_set_nonroot(NETLINK_GENERIC, NL_NONROOT_RECV);
 
-       /* 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 = register_pernet_subsys(&genl_pernet_ops);
+       if (err)
+               goto problem;
 
        err = genl_register_mc_group(&genl_ctrl, &notify_grp);
        if (err < 0)
-               goto errout_register;
+               goto problem;
 
        return 0;
 
-errout_register:
-       genl_unregister_family(&genl_ctrl);
-errout:
+problem:
        panic("GENL: Cannot register controller: %d\n", 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 pid, 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,
+                                             pid, group, flags);
+                       if (err)
+                               goto error;
+               }
+
+               prev = net;
+       }
+
+       return nlmsg_multicast(prev->genl_sock, skb, pid, group, flags);
+ error:
+       kfree_skb(skb);
+       return err;
+}
+
+int genlmsg_multicast_allns(struct sk_buff *skb, u32 pid, unsigned int group,
+                           gfp_t flags)
+{
+       return genlmsg_mcast(skb, pid, group, flags);
+}
+EXPORT_SYMBOL(genlmsg_multicast_allns);