Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf

Daniel Borkmann says:

====================
pull-request: bpf 2018-02-09

The following pull-request contains BPF updates for your *net* tree.

The main changes are:

1) Two fixes for BPF sockmap in order to break up circular map references
   from programs attached to sockmap, and detaching related sockets in
   case of socket close() event. For the latter we get rid of the
   smap_state_change() and plug into ULP infrastructure, which will later
   also be used for additional features anyway such as TX hooks. For the
   second issue, dependency chain is broken up via map release callback
   to free parse/verdict programs, all from John.

2) Fix a libbpf relocation issue that was found while implementing XDP
   support for Suricata project. Issue was that when clang was invoked
   with default target instead of bpf target, then various other e.g.
   debugging relevant sections are added to the ELF file that contained
   relocation entries pointing to non-BPF related sections which libbpf
   trips over instead of skipping them. Test cases for libbpf are added
   as well, from Jesper.

3) Various misc fixes for bpftool and one for libbpf: a small addition
   to libbpf to make sure it recognizes all standard section prefixes.
   Then, the Makefile in bpftool/Documentation is improved to explicitly
   check for rst2man being installed on the system as we otherwise risk
   installing empty man pages; the man page for bpftool-map is corrected
   and a set of missing bash completions added in order to avoid shipping
   bpftool where the completions are only partially working, from Quentin.

4) Fix applying the relocation to immediate load instructions in the
   nfp JIT which were missing a shift, from Jakub.

5) Two fixes for the BPF kernel selftests: handle CONFIG_BPF_JIT_ALWAYS_ON=y
   gracefully in test_bpf.ko module and mark them as FLAG_EXPECTED_FAIL
   in this case; and explicitly delete the veth devices in the two tests
   test_xdp_{meta,redirect}.sh before dismantling the netnses as when
   selftests are run in batch mode, then workqueue to handle destruction
   might not have finished yet and thus veth creation in next test under
   same dev name would fail, from Yonghong.

6) Fix test_kmod.sh to check the test_bpf.ko module path before performing
   an insmod, and fallback to modprobe. Especially the latter is useful
   when having a device under test that has the modules installed instead,
   from Naresh.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 54 insertions, 5 deletions

diff --git a/net/ipv4/tcp_ulp.c b/net/ipv4/tcp_ulp.c
index 6bb9e14c710a..622caa4039e0 100644
--- a/net/ipv4/tcp_ulp.c
+++ b/net/ipv4/tcp_ulp.c
@@ -29,6 +29,18 @@ static struct tcp_ulp_ops *tcp_ulp_find(const char *name)
 	return NULL;
 }
 
+static struct tcp_ulp_ops *tcp_ulp_find_id(const int ulp)
+{
+	struct tcp_ulp_ops *e;
+
+	list_for_each_entry_rcu(e, &tcp_ulp_list, list) {
+		if (e->uid == ulp)
+			return e;
+	}
+
+	return NULL;
+}
+
 static const struct tcp_ulp_ops *__tcp_ulp_find_autoload(const char *name)
 {
 	const struct tcp_ulp_ops *ulp = NULL;
@@ -51,6 +63,18 @@ static const struct tcp_ulp_ops *__tcp_ulp_find_autoload(const char *name)
 	return ulp;
 }
 
+static const struct tcp_ulp_ops *__tcp_ulp_lookup(const int uid)
+{
+	const struct tcp_ulp_ops *ulp;
+
+	rcu_read_lock();
+	ulp = tcp_ulp_find_id(uid);
+	if (!ulp || !try_module_get(ulp->owner))
+		ulp = NULL;
+	rcu_read_unlock();
+	return ulp;
+}
+
 /* Attach new upper layer protocol to the list
  * of available protocols.
  */
@@ -59,13 +83,10 @@ int tcp_register_ulp(struct tcp_ulp_ops *ulp)
 	int ret = 0;
 
 	spin_lock(&tcp_ulp_list_lock);
-	if (tcp_ulp_find(ulp->name)) {
-		pr_notice("%s already registered or non-unique name\n",
-			  ulp->name);
+	if (tcp_ulp_find(ulp->name))
 		ret = -EEXIST;
-	} else {
+	else
 		list_add_tail_rcu(&ulp->list, &tcp_ulp_list);
-	}
 	spin_unlock(&tcp_ulp_list_lock);
 
 	return ret;
@@ -124,6 +145,34 @@ int tcp_set_ulp(struct sock *sk, const char *name)
 	if (!ulp_ops)
 		return -ENOENT;
 
+	if (!ulp_ops->user_visible) {
+		module_put(ulp_ops->owner);
+		return -ENOENT;
+	}
+
+	err = ulp_ops->init(sk);
+	if (err) {
+		module_put(ulp_ops->owner);
+		return err;
+	}
+
+	icsk->icsk_ulp_ops = ulp_ops;
+	return 0;
+}
+
+int tcp_set_ulp_id(struct sock *sk, int ulp)
+{
+	struct inet_connection_sock *icsk = inet_csk(sk);
+	const struct tcp_ulp_ops *ulp_ops;
+	int err;
+
+	if (icsk->icsk_ulp_ops)
+		return -EEXIST;
+
+	ulp_ops = __tcp_ulp_lookup(ulp);
+	if (!ulp_ops)
+		return -ENOENT;
+
 	err = ulp_ops->init(sk);
 	if (err) {
 		module_put(ulp_ops->owner);