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authorCyrill Gorcunov <gorcunov@gmail.com>2016-10-21 13:03:44 +0300
committerDavid S. Miller <davem@davemloft.net>2016-10-23 19:35:24 -0400
commit432490f9d455fb842d70219f22d9d2c812371676 (patch)
tree01ab391e2f17661a54596e5258603293178835c2 /net/ipv4/raw_diag.c
parentf76a9db351f8beb3259c4ba38058de0058ab8000 (diff)
downloadlinux-432490f9d455fb842d70219f22d9d2c812371676.tar.bz2
net: ip, diag -- Add diag interface for raw sockets
In criu we are actively using diag interface to collect sockets present in the system when dumping applications. And while for unix, tcp, udp[lite], packet, netlink it works as expected, the raw sockets do not have. Thus add it. v2: - add missing sock_put calls in raw_diag_dump_one (by eric.dumazet@) - implement @destroy for diag requests (by dsa@) v3: - add export of raw_abort for IPv6 (by dsa@) - pass net-admin flag into inet_sk_diag_fill due to changes in net-next branch (by dsa@) v4: - use @pad in struct inet_diag_req_v2 for raw socket protocol specification: raw module carries sockets which may have custom protocol passed from socket() syscall and sole @sdiag_protocol is not enough to match underlied ones - start reporting protocol specifed in socket() call when sockets are raw ones for the same reason: user space tools like ss may parse this attribute and use it for socket matching v5 (by eric.dumazet@): - use sock_hold in raw_sock_get instead of atomic_inc, we're holding (raw_v4_hashinfo|raw_v6_hashinfo)->lock when looking up so counter won't be zero here. v6: - use sdiag_raw_protocol() helper which will access @pad structure used for raw sockets protocol specification: we can't simply rename this member without breaking uapi v7: - sine sdiag_raw_protocol() helper is not suitable for uapi lets rather make an alias structure with proper names. __check_inet_diag_req_raw helper will catch if any of structure unintentionally changed. CC: David S. Miller <davem@davemloft.net> CC: Eric Dumazet <eric.dumazet@gmail.com> CC: David Ahern <dsa@cumulusnetworks.com> CC: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> CC: James Morris <jmorris@namei.org> CC: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org> CC: Patrick McHardy <kaber@trash.net> CC: Andrey Vagin <avagin@openvz.org> CC: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/raw_diag.c')
-rw-r--r--net/ipv4/raw_diag.c261
1 files changed, 261 insertions, 0 deletions
diff --git a/net/ipv4/raw_diag.c b/net/ipv4/raw_diag.c
new file mode 100644
index 000000000000..ef3bea061b75
--- /dev/null
+++ b/net/ipv4/raw_diag.c
@@ -0,0 +1,261 @@
+#include <linux/module.h>
+
+#include <linux/inet_diag.h>
+#include <linux/sock_diag.h>
+
+#include <net/raw.h>
+#include <net/rawv6.h>
+
+#ifdef pr_fmt
+# undef pr_fmt
+#endif
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+static struct raw_hashinfo *
+raw_get_hashinfo(const struct inet_diag_req_v2 *r)
+{
+ if (r->sdiag_family == AF_INET) {
+ return &raw_v4_hashinfo;
+#if IS_ENABLED(CONFIG_IPV6)
+ } else if (r->sdiag_family == AF_INET6) {
+ return &raw_v6_hashinfo;
+#endif
+ } else {
+ pr_warn_once("Unexpected inet family %d\n",
+ r->sdiag_family);
+ WARN_ON_ONCE(1);
+ return ERR_PTR(-EINVAL);
+ }
+}
+
+/*
+ * Due to requirement of not breaking user API we can't simply
+ * rename @pad field in inet_diag_req_v2 structure, instead
+ * use helper to figure it out.
+ */
+
+static struct sock *raw_lookup(struct net *net, struct sock *from,
+ const struct inet_diag_req_v2 *req)
+{
+ struct inet_diag_req_raw *r = (void *)req;
+ struct sock *sk = NULL;
+
+ if (r->sdiag_family == AF_INET)
+ sk = __raw_v4_lookup(net, from, r->sdiag_raw_protocol,
+ r->id.idiag_dst[0],
+ r->id.idiag_src[0],
+ r->id.idiag_if);
+#if IS_ENABLED(CONFIG_IPV6)
+ else
+ sk = __raw_v6_lookup(net, from, r->sdiag_raw_protocol,
+ (const struct in6_addr *)r->id.idiag_src,
+ (const struct in6_addr *)r->id.idiag_dst,
+ r->id.idiag_if);
+#endif
+ return sk;
+}
+
+static struct sock *raw_sock_get(struct net *net, const struct inet_diag_req_v2 *r)
+{
+ struct raw_hashinfo *hashinfo = raw_get_hashinfo(r);
+ struct sock *sk = NULL, *s;
+ int slot;
+
+ if (IS_ERR(hashinfo))
+ return ERR_CAST(hashinfo);
+
+ read_lock(&hashinfo->lock);
+ for (slot = 0; slot < RAW_HTABLE_SIZE; slot++) {
+ sk_for_each(s, &hashinfo->ht[slot]) {
+ sk = raw_lookup(net, s, r);
+ if (sk) {
+ /*
+ * Grab it and keep until we fill
+ * diag meaage to be reported, so
+ * caller should call sock_put then.
+ * We can do that because we're keeping
+ * hashinfo->lock here.
+ */
+ sock_hold(sk);
+ break;
+ }
+ }
+ }
+ read_unlock(&hashinfo->lock);
+
+ return sk ? sk : ERR_PTR(-ENOENT);
+}
+
+static int raw_diag_dump_one(struct sk_buff *in_skb,
+ const struct nlmsghdr *nlh,
+ const struct inet_diag_req_v2 *r)
+{
+ struct net *net = sock_net(in_skb->sk);
+ struct sk_buff *rep;
+ struct sock *sk;
+ int err;
+
+ sk = raw_sock_get(net, r);
+ if (IS_ERR(sk))
+ return PTR_ERR(sk);
+
+ rep = nlmsg_new(sizeof(struct inet_diag_msg) +
+ sizeof(struct inet_diag_meminfo) + 64,
+ GFP_KERNEL);
+ if (!rep) {
+ sock_put(sk);
+ return -ENOMEM;
+ }
+
+ err = inet_sk_diag_fill(sk, NULL, rep, r,
+ sk_user_ns(NETLINK_CB(in_skb).sk),
+ NETLINK_CB(in_skb).portid,
+ nlh->nlmsg_seq, 0, nlh,
+ netlink_net_capable(in_skb, CAP_NET_ADMIN));
+ sock_put(sk);
+
+ if (err < 0) {
+ kfree_skb(rep);
+ return err;
+ }
+
+ err = netlink_unicast(net->diag_nlsk, rep,
+ NETLINK_CB(in_skb).portid,
+ MSG_DONTWAIT);
+ if (err > 0)
+ err = 0;
+ return err;
+}
+
+static int sk_diag_dump(struct sock *sk, struct sk_buff *skb,
+ struct netlink_callback *cb,
+ const struct inet_diag_req_v2 *r,
+ struct nlattr *bc, bool net_admin)
+{
+ if (!inet_diag_bc_sk(bc, sk))
+ return 0;
+
+ return inet_sk_diag_fill(sk, NULL, skb, r,
+ sk_user_ns(NETLINK_CB(cb->skb).sk),
+ NETLINK_CB(cb->skb).portid,
+ cb->nlh->nlmsg_seq, NLM_F_MULTI,
+ cb->nlh, net_admin);
+}
+
+static void raw_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
+ const struct inet_diag_req_v2 *r, struct nlattr *bc)
+{
+ bool net_admin = netlink_net_capable(cb->skb, CAP_NET_ADMIN);
+ struct raw_hashinfo *hashinfo = raw_get_hashinfo(r);
+ struct net *net = sock_net(skb->sk);
+ int num, s_num, slot, s_slot;
+ struct sock *sk = NULL;
+
+ if (IS_ERR(hashinfo))
+ return;
+
+ s_slot = cb->args[0];
+ num = s_num = cb->args[1];
+
+ read_lock(&hashinfo->lock);
+ for (slot = s_slot; slot < RAW_HTABLE_SIZE; s_num = 0, slot++) {
+ num = 0;
+
+ sk_for_each(sk, &hashinfo->ht[slot]) {
+ struct inet_sock *inet = inet_sk(sk);
+
+ if (!net_eq(sock_net(sk), net))
+ continue;
+ if (num < s_num)
+ goto next;
+ if (sk->sk_family != r->sdiag_family)
+ goto next;
+ if (r->id.idiag_sport != inet->inet_sport &&
+ r->id.idiag_sport)
+ goto next;
+ if (r->id.idiag_dport != inet->inet_dport &&
+ r->id.idiag_dport)
+ goto next;
+ if (sk_diag_dump(sk, skb, cb, r, bc, net_admin) < 0)
+ goto out_unlock;
+next:
+ num++;
+ }
+ }
+
+out_unlock:
+ read_unlock(&hashinfo->lock);
+
+ cb->args[0] = slot;
+ cb->args[1] = num;
+}
+
+static void raw_diag_get_info(struct sock *sk, struct inet_diag_msg *r,
+ void *info)
+{
+ r->idiag_rqueue = sk_rmem_alloc_get(sk);
+ r->idiag_wqueue = sk_wmem_alloc_get(sk);
+}
+
+#ifdef CONFIG_INET_DIAG_DESTROY
+static int raw_diag_destroy(struct sk_buff *in_skb,
+ const struct inet_diag_req_v2 *r)
+{
+ struct net *net = sock_net(in_skb->sk);
+ struct sock *sk;
+
+ sk = raw_sock_get(net, r);
+ if (IS_ERR(sk))
+ return PTR_ERR(sk);
+ return sock_diag_destroy(sk, ECONNABORTED);
+}
+#endif
+
+static const struct inet_diag_handler raw_diag_handler = {
+ .dump = raw_diag_dump,
+ .dump_one = raw_diag_dump_one,
+ .idiag_get_info = raw_diag_get_info,
+ .idiag_type = IPPROTO_RAW,
+ .idiag_info_size = 0,
+#ifdef CONFIG_INET_DIAG_DESTROY
+ .destroy = raw_diag_destroy,
+#endif
+};
+
+static void __always_unused __check_inet_diag_req_raw(void)
+{
+ /*
+ * Make sure the two structures are identical,
+ * except the @pad field.
+ */
+#define __offset_mismatch(m1, m2) \
+ (offsetof(struct inet_diag_req_v2, m1) != \
+ offsetof(struct inet_diag_req_raw, m2))
+
+ BUILD_BUG_ON(sizeof(struct inet_diag_req_v2) !=
+ sizeof(struct inet_diag_req_raw));
+ BUILD_BUG_ON(__offset_mismatch(sdiag_family, sdiag_family));
+ BUILD_BUG_ON(__offset_mismatch(sdiag_protocol, sdiag_protocol));
+ BUILD_BUG_ON(__offset_mismatch(idiag_ext, idiag_ext));
+ BUILD_BUG_ON(__offset_mismatch(pad, sdiag_raw_protocol));
+ BUILD_BUG_ON(__offset_mismatch(idiag_states, idiag_states));
+ BUILD_BUG_ON(__offset_mismatch(id, id));
+#undef __offset_mismatch
+}
+
+static int __init raw_diag_init(void)
+{
+ return inet_diag_register(&raw_diag_handler);
+}
+
+static void __exit raw_diag_exit(void)
+{
+ inet_diag_unregister(&raw_diag_handler);
+}
+
+module_init(raw_diag_init);
+module_exit(raw_diag_exit);
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-255 /* AF_INET - IPPROTO_RAW */);
+MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 10-255 /* AF_INET6 - IPPROTO_RAW */);