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net: bpf: handle return value of post_bind{4,6} and add selftests for it #2375
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Master branch: 1372d34 |
Master branch: 70bc793 |
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…IND() The return value of BPF_CGROUP_RUN_PROG_INET{4,6}_POST_BIND() in __inet_bind() is not handled properly. While the return value is non-zero, it will set inet_saddr and inet_rcv_saddr to 0 and exit: err = BPF_CGROUP_RUN_PROG_INET4_POST_BIND(sk); if (err) { inet->inet_saddr = inet->inet_rcv_saddr = 0; goto out_release_sock; } Let's take UDP for example and see what will happen. For UDP socket, it will be added to 'udp_prot.h.udp_table->hash' and 'udp_prot.h.udp_table->hash2' after the sk->sk_prot->get_port() called success. If 'inet->inet_rcv_saddr' is specified here, then 'sk' will be in the 'hslot2' of 'hash2' that it don't belong to (because inet_saddr is changed to 0), and UDP packet received will not be passed to this sock. If 'inet->inet_rcv_saddr' is not specified here, the sock will work fine, as it can receive packet properly, which is wired, as the 'bind()' is already failed. To undo the get_port() operation, introduce the 'put_port' field for 'struct proto'. For TCP proto, it is inet_put_port(); For UDP proto, it is udp_lib_unhash(); For icmp proto, it is ping_unhash(). Therefore, after sys_bind() fail caused by BPF_CGROUP_RUN_PROG_INET4_POST_BIND(), it will be unbinded, which means that it can try to be binded to another port. Signed-off-by: Menglong Dong <imagedong@tencent.com>
Use C99 initializers for the initialization of 'tests' in test_sock.c. Signed-off-by: Menglong Dong <imagedong@tencent.com>
Master branch: 44bab87 |
With previous patch, kernel is able to 'put_port' after sys_bind() fails. Add the test for that case: rebind another port after sys_bind() fails. If the bind success, it means previous bind operation is already undoed. Signed-off-by: Menglong Dong <imagedong@tencent.com>
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At least one diff in series https://patchwork.kernel.org/project/netdevbpf/list/?series=603210 irrelevant now. Closing PR. |
Pull request for series with
subject: net: bpf: handle return value of post_bind{4,6} and add selftests for it
version: 5
url: https://patchwork.kernel.org/project/netdevbpf/list/?series=603210