From: Lorenz Bauer <lmb@cloudflare.com>
To: daniel@iogearbox.net, ast@kernel.org, andrii@kernel.org
Cc: bpf@vger.kernel.org, netdev@vger.kernel.org,
kernel-team@cloudflare.com, Lorenz Bauer <lmb@cloudflare.com>
Subject: [PATCH bpf-next v2 1/4] net: add SO_NETNS_COOKIE socket option
Date: Fri, 19 Feb 2021 09:51:46 +0000 [thread overview]
Message-ID: <20210219095149.50346-2-lmb@cloudflare.com> (raw)
In-Reply-To: <20210219095149.50346-1-lmb@cloudflare.com>
We need to distinguish which network namespace a socket belongs to.
BPF has the useful bpf_get_netns_cookie helper for this, but accessing
it from user space isn't possible. Add a read-only socket option that
returns the netns cookie, similar to SO_COOKIE. If network namespaces
are disabled, SO_NETNS_COOKIE returns the cookie of init_net.
Signed-off-by: Lorenz Bauer <lmb@cloudflare.com>
---
arch/alpha/include/uapi/asm/socket.h | 2 ++
arch/mips/include/uapi/asm/socket.h | 2 ++
arch/parisc/include/uapi/asm/socket.h | 2 ++
arch/sparc/include/uapi/asm/socket.h | 2 ++
include/uapi/asm-generic/socket.h | 2 ++
net/core/sock.c | 11 +++++++++++
6 files changed, 21 insertions(+)
diff --git a/arch/alpha/include/uapi/asm/socket.h b/arch/alpha/include/uapi/asm/socket.h
index 57420356ce4c..6b3daba60987 100644
--- a/arch/alpha/include/uapi/asm/socket.h
+++ b/arch/alpha/include/uapi/asm/socket.h
@@ -127,6 +127,8 @@
#define SO_PREFER_BUSY_POLL 69
#define SO_BUSY_POLL_BUDGET 70
+#define SO_NETNS_COOKIE 71
+
#if !defined(__KERNEL__)
#if __BITS_PER_LONG == 64
diff --git a/arch/mips/include/uapi/asm/socket.h b/arch/mips/include/uapi/asm/socket.h
index 2d949969313b..cdf404a831b2 100644
--- a/arch/mips/include/uapi/asm/socket.h
+++ b/arch/mips/include/uapi/asm/socket.h
@@ -138,6 +138,8 @@
#define SO_PREFER_BUSY_POLL 69
#define SO_BUSY_POLL_BUDGET 70
+#define SO_NETNS_COOKIE 71
+
#if !defined(__KERNEL__)
#if __BITS_PER_LONG == 64
diff --git a/arch/parisc/include/uapi/asm/socket.h b/arch/parisc/include/uapi/asm/socket.h
index f60904329bbc..5b5351cdcb33 100644
--- a/arch/parisc/include/uapi/asm/socket.h
+++ b/arch/parisc/include/uapi/asm/socket.h
@@ -119,6 +119,8 @@
#define SO_PREFER_BUSY_POLL 0x4043
#define SO_BUSY_POLL_BUDGET 0x4044
+#define SO_NETNS_COOKIE 0x4045
+
#if !defined(__KERNEL__)
#if __BITS_PER_LONG == 64
diff --git a/arch/sparc/include/uapi/asm/socket.h b/arch/sparc/include/uapi/asm/socket.h
index 848a22fbac20..ff79db753dce 100644
--- a/arch/sparc/include/uapi/asm/socket.h
+++ b/arch/sparc/include/uapi/asm/socket.h
@@ -120,6 +120,8 @@
#define SO_PREFER_BUSY_POLL 0x0048
#define SO_BUSY_POLL_BUDGET 0x0049
+#define SO_NETNS_COOKIE 0x004a
+
#if !defined(__KERNEL__)
diff --git a/include/uapi/asm-generic/socket.h b/include/uapi/asm-generic/socket.h
index 4dcd13d097a9..d588c244ec2f 100644
--- a/include/uapi/asm-generic/socket.h
+++ b/include/uapi/asm-generic/socket.h
@@ -122,6 +122,8 @@
#define SO_PREFER_BUSY_POLL 69
#define SO_BUSY_POLL_BUDGET 70
+#define SO_NETNS_COOKIE 71
+
#if !defined(__KERNEL__)
#if __BITS_PER_LONG == 64 || (defined(__x86_64__) && defined(__ILP32__))
diff --git a/net/core/sock.c b/net/core/sock.c
index 0ed98f20448a..de4644aeb58d 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -1614,6 +1614,17 @@ int sock_getsockopt(struct socket *sock, int level, int optname,
v.val = sk->sk_bound_dev_if;
break;
+ case SO_NETNS_COOKIE:
+ lv = sizeof(u64);
+ if (len < lv)
+ return -EINVAL;
+#ifdef CONFIG_NET_NS
+ v.val64 = sock_net(sk)->net_cookie;
+#else
+ v.val64 = init_net.net_cookie;
+#endif
+ break;
+
default:
/* We implement the SO_SNDLOWAT etc to not be settable
* (1003.1g 7).
--
2.27.0
next prev parent reply other threads:[~2021-02-19 9:53 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-19 9:51 [PATCH bpf-next v2 0/4] Expose network namespace cookies to user space Lorenz Bauer
2021-02-19 9:51 ` Lorenz Bauer [this message]
2021-02-19 11:49 ` [PATCH bpf-next v2 1/4] net: add SO_NETNS_COOKIE socket option Eric Dumazet
2021-02-19 12:23 ` Lorenz Bauer
2021-02-19 15:32 ` Eric Dumazet
2021-02-19 9:51 ` [PATCH bpf-next v2 2/4] nsfs: add an ioctl to discover the network namespace cookie Lorenz Bauer
2021-02-19 9:51 ` [PATCH bpf-next v2 3/4] tools/testing: add test for NS_GET_COOKIE Lorenz Bauer
2021-02-19 9:51 ` [PATCH bpf-next v2 4/4] tools/testing: add a selftest for SO_NETNS_COOKIE Lorenz Bauer
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