linux/net/packet/diag.c

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#include <linux/module.h>
#include <linux/sock_diag.h>
#include <linux/net.h>
#include <linux/netdevice.h>
#include <linux/packet_diag.h>
#include <net/net_namespace.h>
#include <net/sock.h>
#include "internal.h"
static int pdiag_put_info(const struct packet_sock *po, struct sk_buff *nlskb)
{
struct packet_diag_info pinfo;
pinfo.pdi_index = po->ifindex;
pinfo.pdi_version = po->tp_version;
pinfo.pdi_reserve = po->tp_reserve;
pinfo.pdi_copy_thresh = po->copy_thresh;
pinfo.pdi_tstamp = po->tp_tstamp;
pinfo.pdi_flags = 0;
if (po->running)
pinfo.pdi_flags |= PDI_RUNNING;
if (po->auxdata)
pinfo.pdi_flags |= PDI_AUXDATA;
if (po->origdev)
pinfo.pdi_flags |= PDI_ORIGDEV;
if (po->has_vnet_hdr)
pinfo.pdi_flags |= PDI_VNETHDR;
if (po->tp_loss)
pinfo.pdi_flags |= PDI_LOSS;
return nla_put(nlskb, PACKET_DIAG_INFO, sizeof(pinfo), &pinfo);
}
static int pdiag_put_mclist(const struct packet_sock *po, struct sk_buff *nlskb)
{
struct nlattr *mca;
struct packet_mclist *ml;
mca = nla_nest_start(nlskb, PACKET_DIAG_MCLIST);
if (!mca)
return -EMSGSIZE;
rtnl_lock();
for (ml = po->mclist; ml; ml = ml->next) {
struct packet_diag_mclist *dml;
dml = nla_reserve_nohdr(nlskb, sizeof(*dml));
if (!dml) {
rtnl_unlock();
nla_nest_cancel(nlskb, mca);
return -EMSGSIZE;
}
dml->pdmc_index = ml->ifindex;
dml->pdmc_type = ml->type;
dml->pdmc_alen = ml->alen;
dml->pdmc_count = ml->count;
BUILD_BUG_ON(sizeof(dml->pdmc_addr) != sizeof(ml->addr));
memcpy(dml->pdmc_addr, ml->addr, sizeof(ml->addr));
}
rtnl_unlock();
nla_nest_end(nlskb, mca);
return 0;
}
static int pdiag_put_ring(struct packet_ring_buffer *ring, int ver, int nl_type,
struct sk_buff *nlskb)
{
struct packet_diag_ring pdr;
if (!ring->pg_vec || ((ver > TPACKET_V2) &&
(nl_type == PACKET_DIAG_TX_RING)))
return 0;
pdr.pdr_block_size = ring->pg_vec_pages << PAGE_SHIFT;
pdr.pdr_block_nr = ring->pg_vec_len;
pdr.pdr_frame_size = ring->frame_size;
pdr.pdr_frame_nr = ring->frame_max + 1;
if (ver > TPACKET_V2) {
pdr.pdr_retire_tmo = ring->prb_bdqc.retire_blk_tov;
pdr.pdr_sizeof_priv = ring->prb_bdqc.blk_sizeof_priv;
pdr.pdr_features = ring->prb_bdqc.feature_req_word;
} else {
pdr.pdr_retire_tmo = 0;
pdr.pdr_sizeof_priv = 0;
pdr.pdr_features = 0;
}
return nla_put(nlskb, nl_type, sizeof(pdr), &pdr);
}
static int pdiag_put_rings_cfg(struct packet_sock *po, struct sk_buff *skb)
{
int ret;
mutex_lock(&po->pg_vec_lock);
ret = pdiag_put_ring(&po->rx_ring, po->tp_version,
PACKET_DIAG_RX_RING, skb);
if (!ret)
ret = pdiag_put_ring(&po->tx_ring, po->tp_version,
PACKET_DIAG_TX_RING, skb);
mutex_unlock(&po->pg_vec_lock);
return ret;
}
static int pdiag_put_fanout(struct packet_sock *po, struct sk_buff *nlskb)
{
int ret = 0;
mutex_lock(&fanout_mutex);
if (po->fanout) {
u32 val;
val = (u32)po->fanout->id | ((u32)po->fanout->type << 16);
ret = nla_put_u32(nlskb, PACKET_DIAG_FANOUT, val);
}
mutex_unlock(&fanout_mutex);
return ret;
}
static int sk_diag_fill(struct sock *sk, struct sk_buff *skb, struct packet_diag_req *req,
u32 portid, u32 seq, u32 flags, int sk_ino)
{
struct nlmsghdr *nlh;
struct packet_diag_msg *rp;
struct packet_sock *po = pkt_sk(sk);
nlh = nlmsg_put(skb, portid, seq, SOCK_DIAG_BY_FAMILY, sizeof(*rp), flags);
if (!nlh)
return -EMSGSIZE;
rp = nlmsg_data(nlh);
rp->pdiag_family = AF_PACKET;
rp->pdiag_type = sk->sk_type;
rp->pdiag_num = ntohs(po->num);
rp->pdiag_ino = sk_ino;
sock_diag_save_cookie(sk, rp->pdiag_cookie);
if ((req->pdiag_show & PACKET_SHOW_INFO) &&
pdiag_put_info(po, skb))
goto out_nlmsg_trim;
if ((req->pdiag_show & PACKET_SHOW_MCLIST) &&
pdiag_put_mclist(po, skb))
goto out_nlmsg_trim;
if ((req->pdiag_show & PACKET_SHOW_RING_CFG) &&
pdiag_put_rings_cfg(po, skb))
goto out_nlmsg_trim;
if ((req->pdiag_show & PACKET_SHOW_FANOUT) &&
pdiag_put_fanout(po, skb))
goto out_nlmsg_trim;
return nlmsg_end(skb, nlh);
out_nlmsg_trim:
nlmsg_cancel(skb, nlh);
return -EMSGSIZE;
}
static int packet_diag_dump(struct sk_buff *skb, struct netlink_callback *cb)
{
int num = 0, s_num = cb->args[0];
struct packet_diag_req *req;
struct net *net;
struct sock *sk;
net = sock_net(skb->sk);
req = nlmsg_data(cb->nlh);
packet: Protect packet sk list with mutex (v2) Change since v1: * Fixed inuse counters access spotted by Eric In patch eea68e2f (packet: Report socket mclist info via diag module) I've introduced a "scheduling in atomic" problem in packet diag module -- the socket list is traversed under rcu_read_lock() while performed under it sk mclist access requires rtnl lock (i.e. -- mutex) to be taken. [152363.820563] BUG: scheduling while atomic: crtools/12517/0x10000002 [152363.820573] 4 locks held by crtools/12517: [152363.820581] #0: (sock_diag_mutex){+.+.+.}, at: [<ffffffff81a2dcb5>] sock_diag_rcv+0x1f/0x3e [152363.820613] #1: (sock_diag_table_mutex){+.+.+.}, at: [<ffffffff81a2de70>] sock_diag_rcv_msg+0xdb/0x11a [152363.820644] #2: (nlk->cb_mutex){+.+.+.}, at: [<ffffffff81a67d01>] netlink_dump+0x23/0x1ab [152363.820693] #3: (rcu_read_lock){.+.+..}, at: [<ffffffff81b6a049>] packet_diag_dump+0x0/0x1af Similar thing was then re-introduced by further packet diag patches (fanount mutex and pgvec mutex for rings) :( Apart from being terribly sorry for the above, I propose to change the packet sk list protection from spinlock to mutex. This lock currently protects two modifications: * sklist * prot inuse counters The sklist modifications can be just reprotected with mutex since they already occur in a sleeping context. The inuse counters modifications are trickier -- the __this_cpu_-s are used inside, thus requiring the caller to handle the potential issues with contexts himself. Since packet sockets' counters are modified in two places only (packet_create and packet_release) we only need to protect the context from being preempted. BH disabling is not required in this case. Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-08-21 01:06:47 +00:00
mutex_lock(&net->packet.sklist_lock);
hlist: drop the node parameter from iterators I'm not sure why, but the hlist for each entry iterators were conceived list_for_each_entry(pos, head, member) The hlist ones were greedy and wanted an extra parameter: hlist_for_each_entry(tpos, pos, head, member) Why did they need an extra pos parameter? I'm not quite sure. Not only they don't really need it, it also prevents the iterator from looking exactly like the list iterator, which is unfortunate. Besides the semantic patch, there was some manual work required: - Fix up the actual hlist iterators in linux/list.h - Fix up the declaration of other iterators based on the hlist ones. - A very small amount of places were using the 'node' parameter, this was modified to use 'obj->member' instead. - Coccinelle didn't handle the hlist_for_each_entry_safe iterator properly, so those had to be fixed up manually. The semantic patch which is mostly the work of Peter Senna Tschudin is here: @@ iterator name hlist_for_each_entry, hlist_for_each_entry_continue, hlist_for_each_entry_from, hlist_for_each_entry_rcu, hlist_for_each_entry_rcu_bh, hlist_for_each_entry_continue_rcu_bh, for_each_busy_worker, ax25_uid_for_each, ax25_for_each, inet_bind_bucket_for_each, sctp_for_each_hentry, sk_for_each, sk_for_each_rcu, sk_for_each_from, sk_for_each_safe, sk_for_each_bound, hlist_for_each_entry_safe, hlist_for_each_entry_continue_rcu, nr_neigh_for_each, nr_neigh_for_each_safe, nr_node_for_each, nr_node_for_each_safe, for_each_gfn_indirect_valid_sp, for_each_gfn_sp, for_each_host; type T; expression a,c,d,e; identifier b; statement S; @@ -T b; <+... when != b ( hlist_for_each_entry(a, - b, c, d) S | hlist_for_each_entry_continue(a, - b, c) S | hlist_for_each_entry_from(a, - b, c) S | hlist_for_each_entry_rcu(a, - b, c, d) S | hlist_for_each_entry_rcu_bh(a, - b, c, d) S | hlist_for_each_entry_continue_rcu_bh(a, - b, c) S | for_each_busy_worker(a, c, - b, d) S | ax25_uid_for_each(a, - b, c) S | ax25_for_each(a, - b, c) S | inet_bind_bucket_for_each(a, - b, c) S | sctp_for_each_hentry(a, - b, c) S | sk_for_each(a, - b, c) S | sk_for_each_rcu(a, - b, c) S | sk_for_each_from -(a, b) +(a) S + sk_for_each_from(a) S | sk_for_each_safe(a, - b, c, d) S | sk_for_each_bound(a, - b, c) S | hlist_for_each_entry_safe(a, - b, c, d, e) S | hlist_for_each_entry_continue_rcu(a, - b, c) S | nr_neigh_for_each(a, - b, c) S | nr_neigh_for_each_safe(a, - b, c, d) S | nr_node_for_each(a, - b, c) S | nr_node_for_each_safe(a, - b, c, d) S | - for_each_gfn_sp(a, c, d, b) S + for_each_gfn_sp(a, c, d) S | - for_each_gfn_indirect_valid_sp(a, c, d, b) S + for_each_gfn_indirect_valid_sp(a, c, d) S | for_each_host(a, - b, c) S | for_each_host_safe(a, - b, c, d) S | for_each_mesh_entry(a, - b, c, d) S ) ...+> [akpm@linux-foundation.org: drop bogus change from net/ipv4/raw.c] [akpm@linux-foundation.org: drop bogus hunk from net/ipv6/raw.c] [akpm@linux-foundation.org: checkpatch fixes] [akpm@linux-foundation.org: fix warnings] [akpm@linux-foudnation.org: redo intrusive kvm changes] Tested-by: Peter Senna Tschudin <peter.senna@gmail.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Gleb Natapov <gleb@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-28 01:06:00 +00:00
sk_for_each(sk, &net->packet.sklist) {
if (!net_eq(sock_net(sk), net))
continue;
if (num < s_num)
goto next;
if (sk_diag_fill(sk, skb, req, NETLINK_CB(cb->skb).portid,
cb->nlh->nlmsg_seq, NLM_F_MULTI,
sock_i_ino(sk)) < 0)
goto done;
next:
num++;
}
done:
packet: Protect packet sk list with mutex (v2) Change since v1: * Fixed inuse counters access spotted by Eric In patch eea68e2f (packet: Report socket mclist info via diag module) I've introduced a "scheduling in atomic" problem in packet diag module -- the socket list is traversed under rcu_read_lock() while performed under it sk mclist access requires rtnl lock (i.e. -- mutex) to be taken. [152363.820563] BUG: scheduling while atomic: crtools/12517/0x10000002 [152363.820573] 4 locks held by crtools/12517: [152363.820581] #0: (sock_diag_mutex){+.+.+.}, at: [<ffffffff81a2dcb5>] sock_diag_rcv+0x1f/0x3e [152363.820613] #1: (sock_diag_table_mutex){+.+.+.}, at: [<ffffffff81a2de70>] sock_diag_rcv_msg+0xdb/0x11a [152363.820644] #2: (nlk->cb_mutex){+.+.+.}, at: [<ffffffff81a67d01>] netlink_dump+0x23/0x1ab [152363.820693] #3: (rcu_read_lock){.+.+..}, at: [<ffffffff81b6a049>] packet_diag_dump+0x0/0x1af Similar thing was then re-introduced by further packet diag patches (fanount mutex and pgvec mutex for rings) :( Apart from being terribly sorry for the above, I propose to change the packet sk list protection from spinlock to mutex. This lock currently protects two modifications: * sklist * prot inuse counters The sklist modifications can be just reprotected with mutex since they already occur in a sleeping context. The inuse counters modifications are trickier -- the __this_cpu_-s are used inside, thus requiring the caller to handle the potential issues with contexts himself. Since packet sockets' counters are modified in two places only (packet_create and packet_release) we only need to protect the context from being preempted. BH disabling is not required in this case. Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-08-21 01:06:47 +00:00
mutex_unlock(&net->packet.sklist_lock);
cb->args[0] = num;
return skb->len;
}
static int packet_diag_handler_dump(struct sk_buff *skb, struct nlmsghdr *h)
{
int hdrlen = sizeof(struct packet_diag_req);
struct net *net = sock_net(skb->sk);
struct packet_diag_req *req;
if (nlmsg_len(h) < hdrlen)
return -EINVAL;
req = nlmsg_data(h);
/* Make it possible to support protocol filtering later */
if (req->sdiag_protocol)
return -EINVAL;
if (h->nlmsg_flags & NLM_F_DUMP) {
struct netlink_dump_control c = {
.dump = packet_diag_dump,
};
return netlink_dump_start(net->diag_nlsk, skb, h, &c);
} else
return -EOPNOTSUPP;
}
static const struct sock_diag_handler packet_diag_handler = {
.family = AF_PACKET,
.dump = packet_diag_handler_dump,
};
static int __init packet_diag_init(void)
{
return sock_diag_register(&packet_diag_handler);
}
static void __exit packet_diag_exit(void)
{
sock_diag_unregister(&packet_diag_handler);
}
module_init(packet_diag_init);
module_exit(packet_diag_exit);
MODULE_LICENSE("GPL");
MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 17 /* AF_PACKET */);