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path: root/net/ipv4/tcp_ulp.c
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2020-03-10bpf: sockmap: Only check ULP for TCP socketsLorenz Bauer1-7/+0
The sock map code checks that a socket does not have an active upper layer protocol before inserting it into the map. This requires casting via inet_csk, which isn't valid for UDP sockets. Guard checks for ULP by checking inet_sk(sk)->is_icsk first. Signed-off-by: Lorenz Bauer <lmb@cloudflare.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20200309111243.6982-2-lmb@cloudflare.com
2020-02-25tcp, ulp: Pass lockdep expression to RCU listsAmol Grover1-1/+2
tcp_ulp_list is traversed using list_for_each_entry_rcu outside an RCU read-side critical section but under the protection of tcp_ulp_list_lock. Hence, add corresponding lockdep expression to silence false-positive warnings, and harden RCU lists.t Signed-off-by: Amol Grover <frextrite@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-02-22net, sk_msg: Annotate lockless access to sk_prot on cloneJakub Sitnicki1-1/+2
sk_msg and ULP frameworks override protocol callbacks pointer in sk->sk_prot, while tcp accesses it locklessly when cloning the listening socket, that is with neither sk_lock nor sk_callback_lock held. Once we enable use of listening sockets with sockmap (and hence sk_msg), there will be shared access to sk->sk_prot if socket is getting cloned while being inserted/deleted to/from the sockmap from another CPU: Read side: tcp_v4_rcv sk = __inet_lookup_skb(...) tcp_check_req(sk) inet_csk(sk)->icsk_af_ops->syn_recv_sock tcp_v4_syn_recv_sock tcp_create_openreq_child inet_csk_clone_lock sk_clone_lock READ_ONCE(sk->sk_prot) Write side: sock_map_ops->map_update_elem sock_map_update_elem sock_map_update_common sock_map_link_no_progs tcp_bpf_init tcp_bpf_update_sk_prot sk_psock_update_proto WRITE_ONCE(sk->sk_prot, ops) sock_map_ops->map_delete_elem sock_map_delete_elem __sock_map_delete sock_map_unref sk_psock_put sk_psock_drop sk_psock_restore_proto tcp_update_ulp WRITE_ONCE(sk->sk_prot, proto) Mark the shared access with READ_ONCE/WRITE_ONCE annotations. Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20200218171023.844439-2-jakub@cloudflare.com
2020-01-16bpf: Sockmap/tls, push write_space updates through ulp updatesJohn Fastabend1-2/+4
When sockmap sock with TLS enabled is removed we cleanup bpf/psock state and call tcp_update_ulp() to push updates to TLS ULP on top. However, we don't push the write_space callback up and instead simply overwrite the op with the psock stored previous op. This may or may not be correct so to ensure we don't overwrite the TLS write space hook pass this field to the ULP and have it fixup the ctx. This completes a previous fix that pushed the ops through to the ULP but at the time missed doing this for write_space, presumably because write_space TLS hook was added around the same time. Fixes: 95fa145479fbc ("bpf: sockmap/tls, close can race with map free") Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com> Acked-by: Jonathan Lemon <jonathan.lemon@gmail.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/bpf/20200111061206.8028-4-john.fastabend@gmail.com
2019-11-21tcp: warn if offset reach the maxlen limit when using snprintfHangbin Liu1-0/+3
snprintf returns the number of chars that would be written, not number of chars that were actually written. As such, 'offs' may get larger than 'tbl.maxlen', causing the 'tbl.maxlen - offs' being < 0, and since the parameter is size_t, it would overflow. Since using scnprintf may hide the limit error, while the buffer is still enough now, let's just add a WARN_ON_ONCE in case it reach the limit in future. v2: Use WARN_ON_ONCE as Jiri and Eric suggested. Suggested-by: Jiri Benc <jbenc@redhat.com> Signed-off-by: Hangbin Liu <liuhangbin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-07-22bpf: sockmap/tls, close can race with map freeJohn Fastabend1-0/+13
When a map free is called and in parallel a socket is closed we have two paths that can potentially reset the socket prot ops, the bpf close() path and the map free path. This creates a problem with which prot ops should be used from the socket closed side. If the map_free side completes first then we want to call the original lowest level ops. However, if the tls path runs first we want to call the sockmap ops. Additionally there was no locking around prot updates in TLS code paths so the prot ops could be changed multiple times once from TLS path and again from sockmap side potentially leaving ops pointed at either TLS or sockmap when psock and/or tls context have already been destroyed. To fix this race first only update ops inside callback lock so that TLS, sockmap and lowest level all agree on prot state. Second and a ULP callback update() so that lower layers can inform the upper layer when they are being removed allowing the upper layer to reset prot ops. This gets us close to allowing sockmap and tls to be stacked in arbitrary order but will save that patch for *next trees. v4: - make sure we don't free things for device; - remove the checks which swap the callbacks back only if TLS is at the top. Reported-by: syzbot+06537213db7ba2745c4a@syzkaller.appspotmail.com Fixes: 02c558b2d5d6 ("bpf: sockmap, support for msg_peek in sk_msg with redirect ingress") Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: Dirk van der Merwe <dirk.vandermerwe@netronome.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-05-21treewide: Add SPDX license identifier for missed filesThomas Gleixner1-0/+1
Add SPDX license identifiers to all files which: - Have no license information of any form - Have EXPORT_.*_SYMBOL_GPL inside which was used in the initial scan/conversion to ignore the file These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-16tcp, ulp: remove socket lock assertion on ULP cleanupDaniel Borkmann1-2/+4
Eric reported that syzkaller triggered a splat in tcp_cleanup_ulp() where assertion sock_owned_by_me() failed. This happened through inet_csk_prepare_forced_close() first releasing the socket lock, then calling into tcp_done(newsk) which is called after the inet_csk_prepare_forced_close() and therefore without the socket lock held. The sock_owned_by_me() assertion can generally be removed as the only place where tcp_cleanup_ulp() is called from now is out of inet_csk_destroy_sock() -> sk->sk_prot->destroy() where socket is in dead state and unreachable. Therefore, add a comment why the check is not needed instead. Fixes: 8b9088f806e1 ("tcp, ulp: enforce sock_owned_by_me upon ulp init and cleanup") Reported-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-10-15tcp, ulp: remove ulp bits from sockmapDaniel Borkmann1-58/+13
In order to prepare sockmap logic to be used in combination with kTLS we need to detangle it from ULP, and further split it in later commits into a generic API. Joint work with John. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-15tcp, ulp: enforce sock_owned_by_me upon ulp init and cleanupDaniel Borkmann1-0/+4
Whenever the ULP data on the socket is mangled, enforce that the caller has the socket lock held as otherwise things may race with initialization and cleanup callbacks from ulp ops as both would mangle internal socket state. Joint work with John. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-08-17tcp, ulp: fix leftover icsk_ulp_ops preventing sock from reattachDaniel Borkmann1-0/+2
I found that in BPF sockmap programs once we either delete a socket from the map or we updated a map slot and the old socket was purged from the map that these socket can never get reattached into a map even though their related psock has been dropped entirely at that point. Reason is that tcp_cleanup_ulp() leaves the old icsk->icsk_ulp_ops intact, so that on the next tcp_set_ulp_id() the kernel returns an -EEXIST thinking there is still some active ULP attached. BPF sockmap is the only one that has this issue as the other user, kTLS, only calls tcp_cleanup_ulp() from tcp_v4_destroy_sock() whereas sockmap semantics allow dropping the socket from the map with all related psock state being cleaned up. Fixes: 1aa12bdf1bfb ("bpf: sockmap, add sock close() hook to remove socks") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-08-17tcp, ulp: add alias for all ulp modulesDaniel Borkmann1-1/+1
Lets not turn the TCP ULP lookup into an arbitrary module loader as we only intend to load ULP modules through this mechanism, not other unrelated kernel modules: [root@bar]# cat foo.c #include <sys/types.h> #include <sys/socket.h> #include <linux/tcp.h> #include <linux/in.h> int main(void) { int sock = socket(PF_INET, SOCK_STREAM, 0); setsockopt(sock, IPPROTO_TCP, TCP_ULP, "sctp", sizeof("sctp")); return 0; } [root@bar]# gcc foo.c -O2 -Wall [root@bar]# lsmod | grep sctp [root@bar]# ./a.out [root@bar]# lsmod | grep sctp sctp 1077248 4 libcrc32c 16384 3 nf_conntrack,nf_nat,sctp [root@bar]# Fix it by adding module alias to TCP ULP modules, so probing module via request_module() will be limited to tcp-ulp-[name]. The existing modules like kTLS will load fine given tcp-ulp-tls alias, but others will fail to load: [root@bar]# lsmod | grep sctp [root@bar]# ./a.out [root@bar]# lsmod | grep sctp [root@bar]# Sockmap is not affected from this since it's either built-in or not. Fixes: 734942cc4ea6 ("tcp: ULP infrastructure") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-02-06net: add a UID to use for ULP socket assignmentJohn Fastabend1-5/+54
Create a UID field and enum that can be used to assign ULPs to sockets. This saves a set of string comparisons if the ULP id is known. For sockmap, which is added in the next patches, a ULP is used to hook into TCP sockets close state. In this case the ULP being added is done at map insert time and the ULP is known and done on the kernel side. In this case the named lookup is not needed. Because we don't want to expose psock internals to user space socket options a user visible flag is also added. For TLS this is set for BPF it will be cleared. Alos remove pr_notice, user gets an error code back and should check that rather than rely on logs. Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2017-08-15tcp: ulp: avoid module refcnt leak in tcp_set_ulpSabrina Dubroca1-7/+7
__tcp_ulp_find_autoload returns tcp_ulp_ops after taking a reference on the module. Then, if ->init fails, tcp_set_ulp propagates the error but nothing releases that reference. Fixes: 734942cc4ea6 ("tcp: ULP infrastructure") Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-23tcp: fix out-of-bounds access in ULP sysctlJakub Kicinski1-0/+1
KASAN reports out-of-bound access in proc_dostring() coming from proc_tcp_available_ulp() because in case TCP ULP list is empty the buffer allocated for the response will not have anything printed into it. Set the first byte to zero to avoid strlen() going out-of-bounds. Fixes: 734942cc4ea6 ("tcp: ULP infrastructure") Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-15tcp: ULP infrastructureDave Watson1-0/+134
Add the infrustructure for attaching Upper Layer Protocols (ULPs) over TCP sockets. Based on a similar infrastructure in tcp_cong. The idea is that any ULP can add its own logic by changing the TCP proto_ops structure to its own methods. Example usage: setsockopt(sock, SOL_TCP, TCP_ULP, "tls", sizeof("tls")); modules will call: tcp_register_ulp(&tcp_tls_ulp_ops); to register/unregister their ulp, with an init function and name. A list of registered ulps will be returned by tcp_get_available_ulp, which is hooked up to /proc. Example: $ cat /proc/sys/net/ipv4/tcp_available_ulp tls There is currently no functionality to remove or chain ULPs, but it should be possible to add these in the future if needed. Signed-off-by: Boris Pismenny <borisp@mellanox.com> Signed-off-by: Dave Watson <davejwatson@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>