net: dont hold rtnl mutex during netlink dump callbacks
[linux-2.6.git] / net / phonet / pn_netlink.c
index b1ea19a..438accb 100644 (file)
 #include <linux/kernel.h>
 #include <linux/netlink.h>
 #include <linux/phonet.h>
+#include <linux/slab.h>
 #include <net/sock.h>
 #include <net/phonet/pn_dev.h>
 
+/* Device address handling */
+
 static int fill_addr(struct sk_buff *skb, struct net_device *dev, u8 addr,
                     u32 pid, u32 seq, int event);
 
-static void rtmsg_notify(int event, struct net_device *dev, u8 addr)
+void phonet_address_notify(int event, struct net_device *dev, u8 addr)
 {
        struct sk_buff *skb;
        int err = -ENOBUFS;
@@ -47,18 +50,23 @@ static void rtmsg_notify(int event, struct net_device *dev, u8 addr)
                kfree_skb(skb);
                goto errout;
        }
-       err = rtnl_notify(skb, dev_net(dev), 0,
-                         RTNLGRP_PHONET_IFADDR, NULL, GFP_KERNEL);
+       rtnl_notify(skb, dev_net(dev), 0,
+                   RTNLGRP_PHONET_IFADDR, NULL, GFP_KERNEL);
+       return;
 errout:
-       if (err < 0)
-               rtnl_set_sk_err(dev_net(dev), RTNLGRP_PHONET_IFADDR, err);
+       rtnl_set_sk_err(dev_net(dev), RTNLGRP_PHONET_IFADDR, err);
 }
 
-static int newaddr_doit(struct sk_buff *skb, struct nlmsghdr *nlm, void *attr)
+static const struct nla_policy ifa_phonet_policy[IFA_MAX+1] = {
+       [IFA_LOCAL] = { .type = NLA_U8 },
+};
+
+static int addr_doit(struct sk_buff *skb, struct nlmsghdr *nlh, void *attr)
 {
-       struct rtattr **rta = attr;
-       struct ifaddrmsg *ifm = NLMSG_DATA(nlm);
+       struct net *net = sock_net(skb->sk);
+       struct nlattr *tb[IFA_MAX+1];
        struct net_device *dev;
+       struct ifaddrmsg *ifm;
        int err;
        u8 pnaddr;
 
@@ -67,52 +75,28 @@ static int newaddr_doit(struct sk_buff *skb, struct nlmsghdr *nlm, void *attr)
 
        ASSERT_RTNL();
 
-       if (rta[IFA_LOCAL - 1] == NULL)
-               return -EINVAL;
-
-       dev = __dev_get_by_index(&init_net, ifm->ifa_index);
-       if (dev == NULL)
-               return -ENODEV;
+       err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFA_MAX, ifa_phonet_policy);
+       if (err < 0)
+               return err;
 
-       if (ifm->ifa_prefixlen > 0)
+       ifm = nlmsg_data(nlh);
+       if (tb[IFA_LOCAL] == NULL)
                return -EINVAL;
-
-       memcpy(&pnaddr, RTA_DATA(rta[IFA_LOCAL - 1]), 1);
-
-       err = phonet_address_add(dev, pnaddr);
-       if (!err)
-               rtmsg_notify(RTM_NEWADDR, dev, pnaddr);
-       return err;
-}
-
-static int deladdr_doit(struct sk_buff *skb, struct nlmsghdr *nlm, void *attr)
-{
-       struct rtattr **rta = attr;
-       struct ifaddrmsg *ifm = NLMSG_DATA(nlm);
-       struct net_device *dev;
-       int err;
-       u8 pnaddr;
-
-       if (!capable(CAP_SYS_ADMIN))
-               return -EPERM;
-
-       ASSERT_RTNL();
-
-       if (rta[IFA_LOCAL - 1] == NULL)
+       pnaddr = nla_get_u8(tb[IFA_LOCAL]);
+       if (pnaddr & 3)
+               /* Phonet addresses only have 6 high-order bits */
                return -EINVAL;
 
-       dev = __dev_get_by_index(&init_net, ifm->ifa_index);
+       dev = __dev_get_by_index(net, ifm->ifa_index);
        if (dev == NULL)
                return -ENODEV;
 
-       if (ifm->ifa_prefixlen > 0)
-               return -EADDRNOTAVAIL;
-
-       memcpy(&pnaddr, RTA_DATA(rta[IFA_LOCAL - 1]), 1);
-
-       err = phonet_address_del(dev, pnaddr);
+       if (nlh->nlmsg_type == RTM_NEWADDR)
+               err = phonet_address_add(dev, pnaddr);
+       else
+               err = phonet_address_del(dev, pnaddr);
        if (!err)
-               rtmsg_notify(RTM_DELADDR, dev, pnaddr);
+               phonet_address_notify(nlh->nlmsg_type, dev, pnaddr);
        return err;
 }
 
@@ -121,35 +105,35 @@ static int fill_addr(struct sk_buff *skb, struct net_device *dev, u8 addr,
 {
        struct ifaddrmsg *ifm;
        struct nlmsghdr *nlh;
-       unsigned int orig_len = skb->len;
 
-       nlh = NLMSG_PUT(skb, pid, seq, event, sizeof(struct ifaddrmsg));
-       ifm = NLMSG_DATA(nlh);
+       nlh = nlmsg_put(skb, pid, seq, event, sizeof(*ifm), 0);
+       if (nlh == NULL)
+               return -EMSGSIZE;
+
+       ifm = nlmsg_data(nlh);
        ifm->ifa_family = AF_PHONET;
        ifm->ifa_prefixlen = 0;
        ifm->ifa_flags = IFA_F_PERMANENT;
-       ifm->ifa_scope = RT_SCOPE_HOST;
+       ifm->ifa_scope = RT_SCOPE_LINK;
        ifm->ifa_index = dev->ifindex;
-       RTA_PUT(skb, IFA_LOCAL, 1, &addr);
-       nlh->nlmsg_len = skb->len - orig_len;
+       NLA_PUT_U8(skb, IFA_LOCAL, addr);
+       return nlmsg_end(skb, nlh);
 
-       return 0;
-
-nlmsg_failure:
-rtattr_failure:
-       skb_trim(skb, orig_len);
-
-       return -1;
+nla_put_failure:
+       nlmsg_cancel(skb, nlh);
+       return -EMSGSIZE;
 }
 
 static int getaddr_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
 {
+       struct phonet_device_list *pndevs;
        struct phonet_device *pnd;
        int dev_idx = 0, dev_start_idx = cb->args[0];
        int addr_idx = 0, addr_start_idx = cb->args[1];
 
-       spin_lock_bh(&pndevs.lock);
-       list_for_each_entry(pnd, &pndevs.list, list) {
+       pndevs = phonet_device_list(sock_net(skb->sk));
+       rcu_read_lock();
+       list_for_each_entry_rcu(pnd, &pndevs->list, list) {
                u8 addr;
 
                if (dev_idx > dev_start_idx)
@@ -158,29 +142,162 @@ static int getaddr_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
                        continue;
 
                addr_idx = 0;
-               for (addr = find_first_bit(pnd->addrs, 64); addr < 64;
-                       addr = find_next_bit(pnd->addrs, 64, 1+addr)) {
+               for_each_set_bit(addr, pnd->addrs, 64) {
                        if (addr_idx++ < addr_start_idx)
                                continue;
 
                        if (fill_addr(skb, pnd->netdev, addr << 2,
                                         NETLINK_CB(cb->skb).pid,
-                                       cb->nlh->nlmsg_seq, RTM_NEWADDR))
+                                       cb->nlh->nlmsg_seq, RTM_NEWADDR) < 0)
                                goto out;
                }
        }
 
 out:
-       spin_unlock_bh(&pndevs.lock);
+       rcu_read_unlock();
        cb->args[0] = dev_idx;
        cb->args[1] = addr_idx;
 
        return skb->len;
 }
 
-void __init phonet_netlink_register(void)
+/* Routes handling */
+
+static int fill_route(struct sk_buff *skb, struct net_device *dev, u8 dst,
+                       u32 pid, u32 seq, int event)
+{
+       struct rtmsg *rtm;
+       struct nlmsghdr *nlh;
+
+       nlh = nlmsg_put(skb, pid, seq, event, sizeof(*rtm), 0);
+       if (nlh == NULL)
+               return -EMSGSIZE;
+
+       rtm = nlmsg_data(nlh);
+       rtm->rtm_family = AF_PHONET;
+       rtm->rtm_dst_len = 6;
+       rtm->rtm_src_len = 0;
+       rtm->rtm_tos = 0;
+       rtm->rtm_table = RT_TABLE_MAIN;
+       rtm->rtm_protocol = RTPROT_STATIC;
+       rtm->rtm_scope = RT_SCOPE_UNIVERSE;
+       rtm->rtm_type = RTN_UNICAST;
+       rtm->rtm_flags = 0;
+       NLA_PUT_U8(skb, RTA_DST, dst);
+       NLA_PUT_U32(skb, RTA_OIF, dev->ifindex);
+       return nlmsg_end(skb, nlh);
+
+nla_put_failure:
+       nlmsg_cancel(skb, nlh);
+       return -EMSGSIZE;
+}
+
+void rtm_phonet_notify(int event, struct net_device *dev, u8 dst)
+{
+       struct sk_buff *skb;
+       int err = -ENOBUFS;
+
+       skb = nlmsg_new(NLMSG_ALIGN(sizeof(struct ifaddrmsg)) +
+                       nla_total_size(1) + nla_total_size(4), GFP_KERNEL);
+       if (skb == NULL)
+               goto errout;
+       err = fill_route(skb, dev, dst, 0, 0, event);
+       if (err < 0) {
+               WARN_ON(err == -EMSGSIZE);
+               kfree_skb(skb);
+               goto errout;
+       }
+       rtnl_notify(skb, dev_net(dev), 0,
+                         RTNLGRP_PHONET_ROUTE, NULL, GFP_KERNEL);
+       return;
+errout:
+       rtnl_set_sk_err(dev_net(dev), RTNLGRP_PHONET_ROUTE, err);
+}
+
+static const struct nla_policy rtm_phonet_policy[RTA_MAX+1] = {
+       [RTA_DST] = { .type = NLA_U8 },
+       [RTA_OIF] = { .type = NLA_U32 },
+};
+
+static int route_doit(struct sk_buff *skb, struct nlmsghdr *nlh, void *attr)
+{
+       struct net *net = sock_net(skb->sk);
+       struct nlattr *tb[RTA_MAX+1];
+       struct net_device *dev;
+       struct rtmsg *rtm;
+       int err;
+       u8 dst;
+
+       if (!capable(CAP_SYS_ADMIN))
+               return -EPERM;
+
+       ASSERT_RTNL();
+
+       err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_phonet_policy);
+       if (err < 0)
+               return err;
+
+       rtm = nlmsg_data(nlh);
+       if (rtm->rtm_table != RT_TABLE_MAIN || rtm->rtm_type != RTN_UNICAST)
+               return -EINVAL;
+       if (tb[RTA_DST] == NULL || tb[RTA_OIF] == NULL)
+               return -EINVAL;
+       dst = nla_get_u8(tb[RTA_DST]);
+       if (dst & 3) /* Phonet addresses only have 6 high-order bits */
+               return -EINVAL;
+
+       dev = __dev_get_by_index(net, nla_get_u32(tb[RTA_OIF]));
+       if (dev == NULL)
+               return -ENODEV;
+
+       if (nlh->nlmsg_type == RTM_NEWROUTE)
+               err = phonet_route_add(dev, dst);
+       else
+               err = phonet_route_del(dev, dst);
+       if (!err)
+               rtm_phonet_notify(nlh->nlmsg_type, dev, dst);
+       return err;
+}
+
+static int route_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
+{
+       struct net *net = sock_net(skb->sk);
+       u8 addr, addr_idx = 0, addr_start_idx = cb->args[0];
+
+       rcu_read_lock();
+       for (addr = 0; addr < 64; addr++) {
+               struct net_device *dev;
+
+               dev = phonet_route_get_rcu(net, addr << 2);
+               if (!dev)
+                       continue;
+
+               if (addr_idx++ < addr_start_idx)
+                       continue;
+               if (fill_route(skb, dev, addr << 2, NETLINK_CB(cb->skb).pid,
+                               cb->nlh->nlmsg_seq, RTM_NEWROUTE))
+                       goto out;
+       }
+
+out:
+       rcu_read_unlock();
+       cb->args[0] = addr_idx;
+       cb->args[1] = 0;
+
+       return skb->len;
+}
+
+int __init phonet_netlink_register(void)
 {
-       rtnl_register(PF_PHONET, RTM_NEWADDR, newaddr_doit, NULL);
-       rtnl_register(PF_PHONET, RTM_DELADDR, deladdr_doit, NULL);
-       rtnl_register(PF_PHONET, RTM_GETADDR, NULL, getaddr_dumpit);
+       int err = __rtnl_register(PF_PHONET, RTM_NEWADDR, addr_doit, NULL);
+       if (err)
+               return err;
+
+       /* Further __rtnl_register() cannot fail */
+       __rtnl_register(PF_PHONET, RTM_DELADDR, addr_doit, NULL);
+       __rtnl_register(PF_PHONET, RTM_GETADDR, NULL, getaddr_dumpit);
+       __rtnl_register(PF_PHONET, RTM_NEWROUTE, route_doit, NULL);
+       __rtnl_register(PF_PHONET, RTM_DELROUTE, route_doit, NULL);
+       __rtnl_register(PF_PHONET, RTM_GETROUTE, NULL, route_dumpit);
+       return 0;
 }