X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=net%2Fnetlink%2Faf_netlink.c;h=a4957bf2ca60d6963e2d94f9b2e7679df3a0b4b6;hb=9f121a5a80b4417c6db5a35e26d2e79c29c3fc0d;hp=d7d1b822e824a8055ea8310654a69827ea43eabc;hpb=487420df79f1d9f5b9de74c9bef378609c475a39;p=safe%2Fjmp%2Flinux-2.6 diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c index d7d1b82..a4957bf 100644 --- a/net/netlink/af_netlink.c +++ b/net/netlink/af_netlink.c @@ -83,6 +83,11 @@ struct netlink_sock { struct module *module; }; +struct listeners_rcu_head { + struct rcu_head rcu_head; + void *ptr; +}; + #define NETLINK_KERNEL_SOCKET 0x1 #define NETLINK_RECV_PKTINFO 0x2 #define NETLINK_BROADCAST_SEND_ERROR 0x4 @@ -172,9 +177,11 @@ static void netlink_sock_destruct(struct sock *sk) * this, _but_ remember, it adds useless work on UP machines. */ -static void netlink_table_grab(void) +void netlink_table_grab(void) __acquires(nl_table_lock) { + might_sleep(); + write_lock_irq(&nl_table_lock); if (atomic_read(&nl_table_users)) { @@ -195,7 +202,7 @@ static void netlink_table_grab(void) } } -static void netlink_table_ungrab(void) +void netlink_table_ungrab(void) __releases(nl_table_lock) { write_unlock_irq(&nl_table_lock); @@ -421,7 +428,8 @@ static int __netlink_create(struct net *net, struct socket *sock, return 0; } -static int netlink_create(struct net *net, struct socket *sock, int protocol) +static int netlink_create(struct net *net, struct socket *sock, int protocol, + int kern) { struct module *module = NULL; struct mutex *cb_mutex; @@ -490,7 +498,7 @@ static int netlink_release(struct socket *sock) skb_queue_purge(&sk->sk_write_queue); - if (nlk->pid && !nlk->subscriptions) { + if (nlk->pid) { struct netlink_notify n = { .net = sock_net(sk), .protocol = sk->sk_protocol, @@ -700,7 +708,7 @@ static int netlink_getname(struct socket *sock, struct sockaddr *addr, { struct sock *sk = sock->sk; struct netlink_sock *nlk = nlk_sk(sk); - struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr; + DECLARE_SOCKADDR(struct sockaddr_nl *, nladdr, addr); nladdr->nl_family = AF_NETLINK; nladdr->nl_pad = 0; @@ -1084,7 +1092,7 @@ static inline int do_one_set_err(struct sock *sk, if (sk == p->exclude_sk) goto out; - if (sock_net(sk) != sock_net(p->exclude_sk)) + if (!net_eq(sock_net(sk), sock_net(p->exclude_sk))) goto out; if (nlk->pid == p->pid || p->group - 1 >= nlk->ngroups || @@ -1143,7 +1151,7 @@ static void netlink_update_socket_mc(struct netlink_sock *nlk, } static int netlink_setsockopt(struct socket *sock, int level, int optname, - char __user *optval, int optlen) + char __user *optval, unsigned int optlen) { struct sock *sk = sock->sk; struct netlink_sock *nlk = nlk_sk(sk); @@ -1356,7 +1364,7 @@ static int netlink_recvmsg(struct kiocb *kiocb, struct socket *sock, struct netlink_sock *nlk = nlk_sk(sk); int noblock = flags&MSG_DONTWAIT; size_t copied; - struct sk_buff *skb; + struct sk_buff *skb, *frag __maybe_unused = NULL; int err; if (flags&MSG_OOB) @@ -1368,6 +1376,35 @@ static int netlink_recvmsg(struct kiocb *kiocb, struct socket *sock, if (skb == NULL) goto out; +#ifdef CONFIG_COMPAT_NETLINK_MESSAGES + if (unlikely(skb_shinfo(skb)->frag_list)) { + bool need_compat = !!(flags & MSG_CMSG_COMPAT); + + /* + * If this skb has a frag_list, then here that means that + * we will have to use the frag_list skb for compat tasks + * and the regular skb for non-compat tasks. + * + * The skb might (and likely will) be cloned, so we can't + * just reset frag_list and go on with things -- we need to + * keep that. For the compat case that's easy -- simply get + * a reference to the compat skb and free the regular one + * including the frag. For the non-compat case, we need to + * avoid sending the frag to the user -- so assign NULL but + * restore it below before freeing the skb. + */ + if (need_compat) { + struct sk_buff *compskb = skb_shinfo(skb)->frag_list; + skb_get(compskb); + kfree_skb(skb); + skb = compskb; + } else { + frag = skb_shinfo(skb)->frag_list; + skb_shinfo(skb)->frag_list = NULL; + } + } +#endif + msg->msg_namelen = 0; copied = skb->len; @@ -1398,6 +1435,11 @@ static int netlink_recvmsg(struct kiocb *kiocb, struct socket *sock, siocb->scm->creds = *NETLINK_CREDS(skb); if (flags & MSG_TRUNC) copied = skb->len; + +#ifdef CONFIG_COMPAT_NETLINK_MESSAGES + skb_shinfo(skb)->frag_list = frag; +#endif + skb_free_datagram(sk, skb); if (nlk->cb && atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf / 2) @@ -1453,7 +1495,8 @@ netlink_kernel_create(struct net *net, int unit, unsigned int groups, if (groups < 32) groups = 32; - listeners = kzalloc(NLGRPSZ(groups), GFP_KERNEL); + listeners = kzalloc(NLGRPSZ(groups) + sizeof(struct listeners_rcu_head), + GFP_KERNEL); if (!listeners) goto out_sock_release; @@ -1501,6 +1544,49 @@ netlink_kernel_release(struct sock *sk) EXPORT_SYMBOL(netlink_kernel_release); +static void netlink_free_old_listeners(struct rcu_head *rcu_head) +{ + struct listeners_rcu_head *lrh; + + lrh = container_of(rcu_head, struct listeners_rcu_head, rcu_head); + kfree(lrh->ptr); +} + +int __netlink_change_ngroups(struct sock *sk, unsigned int groups) +{ + unsigned long *listeners, *old = NULL; + struct listeners_rcu_head *old_rcu_head; + struct netlink_table *tbl = &nl_table[sk->sk_protocol]; + + if (groups < 32) + groups = 32; + + if (NLGRPSZ(tbl->groups) < NLGRPSZ(groups)) { + listeners = kzalloc(NLGRPSZ(groups) + + sizeof(struct listeners_rcu_head), + GFP_ATOMIC); + if (!listeners) + return -ENOMEM; + old = tbl->listeners; + memcpy(listeners, old, NLGRPSZ(tbl->groups)); + rcu_assign_pointer(tbl->listeners, listeners); + /* + * Free the old memory after an RCU grace period so we + * don't leak it. We use call_rcu() here in order to be + * able to call this function from atomic contexts. The + * allocation of this memory will have reserved enough + * space for struct listeners_rcu_head at the end. + */ + old_rcu_head = (void *)(tbl->listeners + + NLGRPLONGS(tbl->groups)); + old_rcu_head->ptr = old; + call_rcu(&old_rcu_head->rcu_head, netlink_free_old_listeners); + } + tbl->groups = groups; + + return 0; +} + /** * netlink_change_ngroups - change number of multicast groups * @@ -1515,33 +1601,25 @@ EXPORT_SYMBOL(netlink_kernel_release); */ 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; + int err; 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: + err = __netlink_change_ngroups(sk, groups); netlink_table_ungrab(); - synchronize_rcu(); - kfree(old); + return err; } +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]; + + sk_for_each_bound(sk, node, &tbl->mc_list) + netlink_update_socket_mc(nlk_sk(sk), group, 0); +} + /** * netlink_clear_multicast_users - kick off multicast listeners * @@ -1552,15 +1630,8 @@ int netlink_change_ngroups(struct sock *sk, unsigned int groups) */ 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_clear_multicast_users(ksk, group); netlink_table_ungrab(); } @@ -1645,7 +1716,7 @@ errout: } int netlink_dump_start(struct sock *ssk, struct sk_buff *skb, - struct nlmsghdr *nlh, + const struct nlmsghdr *nlh, int (*dump)(struct sk_buff *skb, struct netlink_callback *), int (*done)(struct netlink_callback *)) @@ -1718,7 +1789,7 @@ void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err) } rep = __nlmsg_put(skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq, - NLMSG_ERROR, sizeof(struct nlmsgerr), 0); + NLMSG_ERROR, payload, 0); errmsg = nlmsg_data(rep); errmsg->error = err; memcpy(&errmsg->msg, nlh, err ? nlh->nlmsg_len : sizeof(*nlh)); @@ -1980,7 +2051,7 @@ static const struct proto_ops netlink_ops = { .sendpage = sock_no_sendpage, }; -static struct net_proto_family netlink_family_ops = { +static const struct net_proto_family netlink_family_ops = { .family = PF_NETLINK, .create = netlink_create, .owner = THIS_MODULE, /* for consistency 8) */ @@ -2024,10 +2095,10 @@ static int __init netlink_proto_init(void) if (!nl_table) goto panic; - if (num_physpages >= (128 * 1024)) - limit = num_physpages >> (21 - PAGE_SHIFT); + if (totalram_pages >= (128 * 1024)) + limit = totalram_pages >> (21 - PAGE_SHIFT); else - limit = num_physpages >> (23 - PAGE_SHIFT); + limit = totalram_pages >> (23 - PAGE_SHIFT); order = get_bitmask_order(limit) - 1 + PAGE_SHIFT; limit = (1UL << order) / sizeof(struct hlist_head);