This is much more compact. Thanks to markj@ for suggesting the change. Reviewed by: markj, Peter Lei, imp, Nick Banks Sponsored by: Netflix, Inc. Differential Revision: https://reviews.freebsd.org/D53510 (cherry picked from commit 8e8956f7f99759b21bc07e884ad89d1927c39e8d)
Add /i option to the ddb commands show tcpcb and show all tcpcbs, which enables the printing of the t_inpcb. Reviewed by: markj Sponsored by: Netflix, Inc. Differential Revision: https://reviews.freebsd.org/D53497 (cherry picked from commit 9aa5a79e2af9a6a8930bbe8a7a024df2cf44e433)
Fixes: a62c6b0de48a ("ddb: add optional printing of BBLog entries")
Sponsored by: Netflix, Inc.
(cherry picked from commit 0dc78204a7dcbc51bfab4c701e1335084548bc05)
Add a /b option to show tcpcb and show all tcpcbs to print BBLog entries. Right now this supports the entries generated by the FreeBSD default TCP stack. It should help in debugging issues reported by syzkaller. The syntax for printing sent and received packets is similar to the one used by packetdrill, since the output of ddb will be used to create packetdrill scripts for debugging. Reviewed by: thj Tested by: thj Sponsored by: Netflix, Inc. Differential Revision: https://reviews.freebsd.org/D50629 (cherry picked from commit a62c6b0de48a5b9b752976b2675ac807684b7fdb)
Add a command to show all TCP control blocks. Also provide an option to limit the output to TCP control blocks, which are locked. The plan is to run show all tcpcbs/l when syzkaller triggers a panic. If a TCP control block is affected, it is most likely locked and therefore the command shows the information of the affected TCP control block. Reviewed by: markj, thj Tested by: thj Sponsored by: Netflix, Inc. Differential Revision: https://reviews.freebsd.org/D50516 (cherry picked from commit f1430567f26bc84db3818914fa91c74507d1602a)
Print the name of the TCP function block and the name of the congestion control algorithm. Furthermore, print some information related to Black Box Logging. Reviewed by: thj Sponsored by: Netflix, Inc. Differential Revision: https://reviews.freebsd.org/D50535 (cherry picked from commit 8d4f495df46567dcfcbec59794e9b9137b2f38fe)
The SUS doesn't mention this error code as a possible one [1]. The FreeBSD manual page specifies a possible ECONNRESET for close(2): [ECONNRESET] The underlying object was a stream socket that was shut down by the peer before all pending data was delivered. In the past it had been EINVAL (see 21367f630d72), and this EINVAL was added as a safety measure in 623dce13c64ef. After conversion to ECONNRESET it had been documented in the manual page in 78e3a7fdd51e6, but I bet wasn't ever tested to actually be ever returned, cause the tcp-testsuite[2] didn't exist back then. So documentation is incorrect since 2006, if my bet wins. Anyway, in the modern FreeBSD the condition described above doesn't end up with ECONNRESET error code from close(2). The error condition is reported via SO_ERROR socket option, though. This can be checked using the tcp-testsuite, temporarily disabling the getsockopt(SO_ERROR) lines using sed command [3]. Most of these getsockopt(2)s are followed by '+0.00 close(3) = 0', which will confirm that close(2) doesn't return ECONNRESET even on a socket that has the error stored, neither it is returned in the case described in the manual page. The latter case is covered by multiple tests residing in tcp- testsuite/state-event-engine/rcv-rst-*. However, the deleted block of code could be entered in a race condition between close(2) and processing of incoming packet, when connection had already been half-closed with shutdown(SHUT_WR) and sits in TCPS_LAST_ACK. This was reported in the bug 146845. With the block deleted, we will continue into tcp_disconnect() which has proper handling of INP_DROPPED. The race explanation follows. The connection is in TCPS_LAST_ACK. The network input thread acquires the tcpcb lock first, sets INP_DROPPED, acquires the socket lock in soisdisconnected() and clears SS_ISCONNECTED. Meanwhile, the syscall thread goes through sodisconnect() which checks for SS_ISCONNECTED locklessly(!). The check passes and the thread blocks on the tcpcb lock in tcp_usr_disconnect(). Once input thread releases the lock, the syscall thread observes INP_DROPPED and returns ECONNRESET. - Thread 1: tcp_do_segment()->tcp_close()->in_pcbdrop(),soisdisconnected() - Thread 2: sys_close()...->soclose()->sodisconnect()->tcp_usr_disconnect() Note that the lockless operation in sodisconnect() isn't correct, but enforcing the socket lock there will not fix the problem. [1] https://pubs.opengroup.org/onlinepubs/9799919799/ [2] https://github.com/freebsd-net/tcp-testsuite [3] sed -i "" -Ee '/\+0\.00 getsockopt\(3, SOL_SOCKET, SO_ERROR, \[ECONNRESET\]/d' $(grep -lr ECONNRESET tcp-testsuite) PR: 146845 Reviewed by: tuexen, rrs, imp Differential Revision: https://reviews.freebsd.org/D48148 (cherry picked from commit 053a988497342a6fd0a717cc097d09c23f83e103)
Introduce the net.inet.tcp.bind_all_fibs tunable, set to 1 by default for compatibility with current behaviour. When set to 0, all TCP listening sockets are private to their FIB. Inbound connection requests will only succeed if a matching inpcb is bound to the same FIB as the request. No functional change intended, as the new behaviour is not enabled by default. Reviewed by: glebius MFC after: 2 weeks Sponsored by: Klara, Inc. Sponsored by: Stormshield Differential Revision: https://reviews.freebsd.org/D48663 (cherry picked from commit 5dc99e9bb985dce58e8fc85c09ef4e49bf051971)
Add a flag, INPBIND_FIB, which means that the inpcb is local to its FIB number. When this flag is specified, duplicate bindings are permitted, so long as each FIB contains at most one inpcb bound to the same address/port. If an inpcb is bound with this flag, it'll have the INP_BOUNDFIB flag set. No functional change intended. Reviewed by: glebius MFC after: 2 weeks Sponsored by: Klara, Inc. Sponsored by: Stormshield Differential Revision: https://reviews.freebsd.org/D48661 (cherry picked from commit bbd0084baf7539c7042ce94f8c6770210f83f765)
Update the ddb printing of t_flags and t_flags2 to the current state of definitions in tcp_var.h. Reviewed by: cc Sponsored by: Netflix, Inc. Differential Revision: https://reviews.freebsd.org/D46222 (cherry picked from commit 093d9b46f4720392e53c171eaabfd7a6a8101170)